Work vehicles

Abstract

To provide a work vehicle that prevents the implement from colliding with ridges or other obstacles when turning. [Solution] The work vehicle comprises a vehicle body 1, a traveling device 2 that supports and drives the vehicle body 1, and a work machine 7 that rotates up and down by a lift mechanism 6 provided on the vehicle body 1. Within the working range of the work machine 7 during operation, the work machine 7 moves almost vertically up and down, and above the working range, it rotates. The lift mechanism 6 has a top link 6f located above and a lower link 6g located below. The work machine 7 is connected to the top link 6f and the lower link 6g via a work hitch device 4. The length of the top link 6f is shorter than the length of the lower link 6g, and the pivot point (D) of the top link 6f on the vehicle body is located further back than the pivot point (A) of the lower link 6g on the vehicle body, with respect to the front-rear direction.

Description

Technical Field

[0001] The present invention relates to a work vehicle to which a working machine such as a tiller is attached.

Background Art

[0002] Conventionally, crawler traveling devices are arranged on both sides of a main frame. The crawler traveling devices have driven wheels arranged front and rear, a drive sprocket arranged above the center thereof, and are configured in a substantially triangular shape in side view. A rotary tiller is disposed at the rear of the main frame so as to be movable up and down. The front end of a hydraulic cylinder is pivotally supported by a bracket protruding downward from the main frame, and the rear end of the hydraulic cylinder is pivotally supported rotatably on a rotary case that transmits the power of an engine to a rotary tiller disposed at the rear of the main frame. By expanding and contracting the hydraulic cylinder, a work vehicle configured to be able to raise and lower the rotary tiller is known (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document Ⅰ

Summary of the Invention

Problems to be Solved by the Invention

[0004] Conventionally, during tilling operation, the working machine (tilling part) moves up and down while drawing an arc. During tilling operation, the working machine is raised and lowered to adjust the tilling depth. In particular, when the working machine is raised, the working machine itself moves forward, so that there is an action of pushing the entire work vehicle forward, and there is a drawback of promoting dashing (forward thrust generated by the rotation of the rotor of the tilling part).

[0005] Furthermore, the lifting speed of the implement during tilling is the same as the lifting speed in areas where tilling is not taking place. Therefore, if the lifting speed during tilling is slowed down to allow for more precise adjustment of tilling depth, the lifting speed in areas where tilling is not taking place also slows down, resulting in a longer time to reach the non-working position. Consequently, when raising the tiller to turn near high ridges, the lower part of the tiller sometimes collided with the ridge. Conversely, if the lifting speed in areas where tilling is not taking place is increased, the lifting speed during tilling slows down, resulting in the disadvantage of not being able to adjust the tilling depth with precision.

[0006] This invention aims to provide a work vehicle that takes into account the problems of such conventional work vehicles, allows for precise adjustment of the tilling depth during tilling operations, and prevents the work implement from colliding with ridges or other obstacles when turning. [Means for solving the problem]

[0007] The first invention is, The vehicle comprises a vehicle body 1, a traveling device 2 that supports and moves the vehicle body 1, and a work machine 7 that rotates up and down by a lift mechanism 6 provided on the vehicle body 1. The work vehicle is characterized in that, within the working range of the work implement 7 during operation, the work implement 7 moves almost vertically up and down, and rotates above the working range.

[0008] The second aspect of the present invention comprises a vehicle body 1, a traveling device 2 that supports and travels the vehicle body 1, and a work machine 7 that rotates up and down by a lift mechanism 6 provided on the vehicle body 1. The work vehicle is characterized in that, within the working range of vertical movement of the work implement 7 during operation, the lifting speed of the work implement 7 is slower than the turning speed above the working range.

[0009] The third invention is, The lift mechanism 6 has a top link 6f located above and a lower link 6g located below. The work implement 7 is connected to the top link 6f and the lower link 6g via a work hitch device 4. The first work vehicle of the present invention is characterized in that the length of the top link 6f is shorter than the length of the lower link 6g, and the pivot point D on the vehicle body 1 side of the top link 6f is located further back than the pivot point A on the vehicle body 1 side of the lower link 6g with respect to the front-rear direction.

[0010] The fourth aspect of the present invention is: The length and position of the top link and the length and position of the lower link are determined when the work implement is in the lower limit position within the work range, determining the length of the lower link, the position of the pivot point (A) on the vehicle body side of the lower link and the pivot point (B) on the work hitch device side, determining the position of the work hitch device, setting the top link parallel to the lower link, determining the pivot point (C) on the work hitch device side of the top link, and determining the pivot point (D) on the vehicle body side of the top link at a position where the length of the top link is shorter than the length of the lower link, according to the distance from the lower limit position to the upper limit position within the work range, in the third work vehicle of the present invention.

[0011] The fifth aspect of the present invention is: The lift mechanism 6 comprises a horizontal shaft 6a rotatably supported by a support portion 6a1 fixed to the main frame 1a of the vehicle body 1, a U-shaped bracket 6b rotatably connected at one end to a rod 5a of a drive mechanism cylinder 5 and fixed at the other end to the horizontal shaft 6a, a lower link 6g whose front end is rotatably connected to the support portion 6a1 and whose rear end is rotatably connected to the lower part of the work hitch device 4, a top link 6f whose front end is directly or indirectly rotatably connected to the main frame 1a of the vehicle body 1 and whose rear end is rotatably connected to the upper part of the work hitch device 4, a lift arm 6c whose front end is fixed to the horizontal shaft 6a, and a lift link 6e whose front end is rotatably connected to the rear end of the lift arm 6c and whose rear end is rotatably connected to the central part of the lower link 6g. This is a fourth work vehicle of the present invention.

[0012] The sixth aspect of the present invention is The working hitch device 4 includes a hitch body 4a having a U-shaped cross-section, a top link shaft 4b attached to the upper part of the hitch body 4a and connected to the top link 6f, and a lower link shaft 4c attached to the lower part of the hitch body 4a and connected to the lower link 6g. On both side end faces of the bent portion of the hitch body 4a, bracket 4d having a U-shaped longitudinal section is abutted and fixed. A bearing piece 4e is erected on the upper part of the bracket 4d, and a hole 4d1 is formed in the lower part. Using these bearing piece 4e and hole 4d1, the working hitch device 4 is attached to a predetermined position on the main body of the working machine 7. It is a working vehicle of the fifth invention.

Effect of the Invention

[0013] In the present invention, the lifting speed of the working machine during tilling operation is slower than the speed when the working machine turns upward out of the working range, so that the tilling depth can be adjusted accurately. Also, during turning, the lower part of the working machine jumps up more quickly, so it is less likely to hit even on high ridges. Also, the upper part of the working machine is closely folded against the vehicle body side, so it becomes compact and easy to turn.

Brief Description of the Drawings

[0014] [Figure 1] Left side view of the working vehicle according to the embodiment of the present invention (lowest position) [Figure 2] Perspective view of the main frame 1a of the working vehicle [Figure 3] Partial enlarged view of FIG. 2 [Figure 4] Partial perspective view of the working vehicle [Figure 5] Perspective view of the cylinder attachment of the working vehicle [Figure 6] Rear view of the cylinder attachment [Figure 7] Perspective view centered on the lift mechanism of the working vehicle [Figure 8] Partial enlarged view of the lift mechanism [Figure 9] Partial side view of the lift mechanism [Figure 10] Plan view of the lift mechanism [Figure 11] Perspective view of the contact member of the same lift mechanism [Figure 12] Perspective view of the lift link of the same lift mechanism [Figure 13] Plan view of the same lift link [Figure 14] Perspective view of the lower link of the same lift mechanism [Figure 15] Plan view of the same lower link [Figure 16] Perspective view of the top link of the same lift mechanism [Figure 17] Plan view of the same top link [Figure 18] Bottom-up perspective view of the lift mechanism of the same work vehicle [Figure 19] Perspective view of the lift mechanism seen from the rear [Figure 20] Plan view of the same lift mechanism [Figure 21] Left side view of the same work vehicle (upper limit position of the working range) [Figure 22] Bottom-up perspective view of the lift mechanism in the state of Fig. 21 [Figure 23] Perspective view of the lift mechanism in the state of Fig. 21 seen from the rear [Figure 24] Left side view of the same work vehicle (maximum lift position) [Figure 25] Bottom-up perspective view of the lift mechanism in the state of Fig. 24 [Figure 26] Bottom-up perspective view of the lift mechanism in the state of Fig. 24 [Figure 27] Top-down perspective view of the lift mechanism in the state of Fig. 24 [Figure 28] Top-down perspective view of the lift mechanism in the state of Fig. 24 [Figure 29] (A), (B), (C) Schematic diagrams for explaining the operation of the same lift mechanism [Figure 30] Rear perspective view of the work hitch device of the same work vehicle [Figure 31] Side view of the same work hitch device [Figure 32] Front perspective view of the same work hitch device [Modes for carrying out the invention]

[0015] The embodiments of the present invention will be described in detail below with reference to the drawings.

[0016] Figure 1 is a left side view of an example of a work vehicle according to an embodiment of the present invention, when a tiller is attached. Hereafter, the front and rear and left and right will be defined as the direction of travel of the work vehicle.

[0017] The work vehicle according to this embodiment travels with a crawler-type travel device 2 mounted under the vehicle body 1, and a tiller, which is an example of a work implement 7, is mounted on the rear of the vehicle body 1. Figure 1 shows the case when the work implement 7 is lowered to its lowest position (lower limit of the working range).

[0018] As shown in Figure 2, in the main frame 1a of the vehicle body 1, two parallel plate parts 1b are erected for attaching the battery stay, and a hole 1b1 is provided at the rear end of the plate parts 1b for attaching a cylinder mounting bracket 1c (see Figure 5) for attaching a cylinder 5 as an example of a drive device.

[0019] Furthermore, as shown in Figures 2, 3, and 4, a plate 1b2 is provided between the plate parts 1b to reinforce the plate parts 1b and to attach the cylinder mounting bracket 1c, making the cylinder mounting bracket 1c resistant to the reaction force received from the cylinder 5. Two holes 1b2a for attaching the cylinder mounting bracket 1c are provided vertically in the plate 1b2.

[0020] As shown in Figures 5 and 6, the cylinder mounting fixture 1c has a U-shaped bent plate part 1c1 and a plate part 1c2 welded to its lower part.

[0021] The upper part of plate component 1c1 has two holes 1c1a, one on each side, for attachment to the hole 1b1 of plate component 1b, and nuts are provided on the inside.

[0022] The lower part of the plate component 1c1 is provided with one pin hole 1c1b on each side, which will be used when attaching the cylinder 5.

[0023] The plate component 1c2 is located concentrically with the hole 1c1b provided in the lower part of the plate component 1c1 and is welded to the plate component 1c1.

[0024] In the plate component 1c2, the width of its U-shaped bend is the mounting width of the cylinder 5, and the shape is such that no lateral play occurs in the cylinder 5.

[0025] In the plate component 1c2, holes 1c2a are provided on both the left and right sides of the bent portion for the cylinder mounting pins to pass through. The diameter of these holes 1c2a is larger than the diameter of the hole 1c1b provided at the bottom of the plate component 1c2, so that the plate component 1c2 is not subjected to any force other than the left-right force from the cylinder 5.

[0026] As shown in Figure 1, the lift mechanism 6 is located on the opposite side of the cylinder 5 from where the cylinder mounting bracket 1c is attached.

[0027] This lift mechanism 6 has a support section 6a1 fixedly erected at the rear of the main frame 1a of the vehicle body 1 (see Figures 2 and 7). A contact member 6a2 is attached to the support section 6a1.

[0028] A horizontal shaft 6a is rotatably connected to the support portion 6a1. This horizontal shaft 6a is a round bar that is longer than both sides of the support portion 6a1.

[0029] As shown in Figures 7, 8, 9, and 10, the lift mechanism 6 has a U-shaped bracket 6b at the center of the horizontal shaft 6a that connects to the tip of the rod 5a of the cylinder 5. Holes for welding the horizontal shaft 6a and holes for rotatable connection of the cylinder rod 5a are formed on the left and right sides of the bend of the U-shaped bracket 6b. A tube 6b1 protruding from the mounting hole of the cylinder rod 5a of the U-shaped bracket 6b is provided, extending to the mounting width of the cylinder 5, to prevent lateral displacement of the cylinder 5 and suppress pin wear.

[0030] Furthermore, as shown in Figure 7, the lift mechanism 6 has lift arms 6c fixed in symmetrical positions on both sides of the horizontal shaft 6a, positioned inward from both ends, for attaching the lift links 6e. A tube 6c1 is provided in the hole of the lift arm 6c for attaching the lift links 6e, with a welding allowance on the outside and on the inside so that the lift links 6e can be attached in close proximity.

[0031] In the lift mechanism 6, as described above, a U-shaped bracket 6b and a lift arm 6c are welded to the horizontal shaft 6a. Furthermore, L-shaped plates 6d are provided on the left and right sides, fixed to the main frame 1a, with the axis of the horizontal shaft 6a passing through them between the U-shaped bracket 6b and the lift arm 6c. These left and right L-shaped plates 6d are symmetrical components with an L-shaped bend, differing only in their bending direction.

[0032] In the L-shaped plate 6d, on the side opposite to the mounting surface to the main frame 1a, a rotating center hole through which the axis of the horizontal shaft 6a passes and a hole for attaching the top link 6f are provided. In the L-shaped plate 6d, a bush 6d1 is provided in the hole through which the axis of the horizontal shaft 6a passes to suppress wear of the axis.

[0033] In the L-shaped plate 6d, a pin 6d2 is provided in the hole for attaching the top link 6f. The top link 6f is rotatably connected to the pin 6d2.

[0034] As described above, support parts 6a1 that support both ends of the horizontal shaft 6a are erected on the main frame 1a, and a contact member 6a2 (see Figure 11) that is placed against and fixed to it has a hole through which the axis of the horizontal shaft 6a passes, and two holes for attachment to the support parts 6a1. A tube 6a3 is provided in the hole through which the axis of the horizontal shaft 6a passes, which is located in the center of the contact member 6a2, to suppress wear on the axis.

[0035] Lift links 6e (see Figure 12) are provided on both sides for attachment to the lift arm 6c of the lift mechanism 6. The lift links 6e serve to rotatably connect the lift arm 6c and the lower link 6g, and have holes for the lift arm 6c and the lower link 6g (see Figures 12 and 13). The tube 6c1 of the lift arm 6c is connected to the holes in the lift links 6e, suppressing wear of the pins connecting them.

[0036] Lower links 6g are provided on both the left and right sides, with their ends rotatably connected to a pin 6a11 located at the bottom of the support portion 6a1, and further rotatably connected to the lift link 6e at the central position (see Figures 2, 7, 14, and 15). The lower links 6g have holes 6g1 for attachment to the pin 6a11 of the support portion 6a1, 6g2 for attachment to the lift link 6e, and 6g3 for attachment to the work hitch device 4, which will be described later (see Figures 14 and 15). The hole 6g2 for attaching the lift link 6e is located closer to the hole 6g3 for attaching the work hitch device 4. In the lower links 6g, the welding position of the lift arm 6c is symmetrical only on the side attached to the pin 6a11, on the side attached to the lift link 6e and the side attached to the work hitch device 4.

[0037] The lift link 6e is positioned inside the components of the lift arm 6c and the lower link 6g, and the lift arm 6c and the lower link 6g are positioned on the same plane (see Figure 7).

[0038] As shown in Figures 16 and 17, top links 6f are provided on both the left and right sides, with their bases rotatably connected to the pins 6d2 of the L-shaped plate 6d and their tips rotatably connected to the work hitch device 4. The top links 6f are provided with a hole 6f1 for attaching to the pins 6d2 and a hole 6f2 for attaching to the work hitch device 4.

[0039] In the above configuration, the length of each link decreases in the following order: lower link 6g → lift link 6e → U-shaped bracket 6b → top link 6f → lift arm 6c. In other words, the length of the top link 6f is shorter than the length of the lower link 6g. The method for determining the length and position of the lower link 6g and top link 6f will be described later.

[0040] Figure 18 is a perspective view of the work vehicle in its lowest position according to an embodiment of the present invention, viewed from below with the lift mechanism 6 at the center; Figure 19 is a perspective view of the same vehicle viewed from the rear and above; and Figure 20 is a plan view. Here, by pulling the rod 5a of the cylinder 5 as far forward as possible and pulling the U-shaped bracket 6b forward, the horizontal shaft 6a is rotated, causing the lift arm 6c and lift link 6e to rotate, thereby lowering the lower link 6g to its lowest position, and consequently the top link 6f also descends to its lowest position, resulting in the work hitch device 4 being in its lowest position.

[0041] Here, we will explain how to determine the length and position of the lower link 6g and the top link 6f based on Figure 19.

[0042] Let (A) be the pivot point where the lower link 6g supports the work hitch device 4, (B) be the pivot point of the lower link 6g, (C) be the pivot point where the top link 6f supports the work hitch device 4, and (D) be the pivot point of the top link 6f.

[0043] With the work implement in the lowest position (lowest position) within the above working range, the length of the lower link 6g and the positions of the pivot point (A) on the vehicle side and the pivot point (B) on the work hitch device side of the lower link 6g are determined. Furthermore, the size, position, and orientation of the work hitch device 4 are determined, and the pivot point (C) of the top link on the work hitch device 4 side is determined with the top link 6f parallel to the lower link 6g. In addition, the pivot point (D) on the vehicle side of the top link 6f is determined at a position where the length of the top link 6f is shorter than the length of the lower link 6g. The position of that pivot point (D) is then appropriately determined according to the distance from the lowest position to the upper position within the working range.

[0044] Figure 21 is a left side view of the work vehicle with the tiller 7 of the embodiment of the present invention in the upper limit position of the working range, Figure 22 is a perspective view looking up from below with the lift mechanism 6 at the center in the same state, and Figure 23 is a perspective view looking at it from the rear and above. Here, the working range refers to the range from the lowest position of the tiller 7 in Figure 1 (lower limit position of the working range) to the tilling position just above the ground in Figure 21.

[0045] By extending the rod 5a of the cylinder 5 a predetermined amount backward and moving the U-shaped bracket 6b a predetermined amount backward, the horizontal shaft 6a is rotated, causing the lift arm 6c and lift link 6e to rotate, which brings the lower link 6g to an almost horizontal position, and consequently the top link 6f to a slightly inclined position, resulting in the work hitch device 4 being raised to a middle position.

[0046] Figure 24 is a left side view of the work vehicle with the tiller 7 of the embodiment of the present invention in its highest position, Figure 25 is a perspective view looking up from below with the lift mechanism 6 at the center in that state, Figure 26 is a further enlarged view, Figure 27 is a perspective view looking at it from the rear and above, and Figure 28 is a further enlarged view.Here, by extending the rod 5a of the cylinder 5 as far rear as possible and moving the lower end of the U-shaped bracket 6b as far rear as possible, the horizontal shaft 6a is rotated greatly, causing the lift arm 6c and lift link 6e to rotate, which puts the lower link 6g in an upward diagonal rearward position, and consequently the top link 6f rotates greatly to become almost vertical, resulting in the work hitch device 4 and work implement 7 being in a state where they are raised to their maximum height and rotated.

[0047] Figure 29 is a schematic diagram showing the movement of the lower link 6g and the top link 6f. Figure 29(A) shows the positional relationship between the lower link 6g and the top link 6f when the tiller 7 is at the lower limit position in the working range. Figure 29(B) shows the positional relationship between the lower link 6g and the top link 6f when the tiller 7 is at the upper limit position in the working range. Figure 29(C) shows the positional relationship between the lower link 6g and the top link 6f when the tiller 7 is at its highest position above the working range.

[0048] As is clear from the diagram, the tiller 7 moves almost vertically up and down within the working range, and when it leaves the working range and comes above, it makes a large turn, the lower end of the tiller 7 rises rapidly, and its upper end approaches the vehicle body 1 quickly, making the entire work vehicle compact and stabilizing the center of gravity, so that the lower end of the tiller 7 does not hit the ridge or other obstacles during high-speed turns, and it quickly becomes suitable for turning on ridges and other obstacles.

[0049] Furthermore, since the lifting and lowering speed of the implement during tilling is slower than the speed at which the implement moves out of the working range and rotates upward, the tilling depth can be adjusted with greater precision.

[0050] The following provides a detailed explanation of the work hitch device 4.

[0051] Figures 30, 31, and 32 show the various views of the work hitch device 4. As described above, the vehicle body 1 is equipped with a lift mechanism 6 consisting of a top link 6f and a lower link 6g that can rotate up and down. On the other hand, the work hitch device 4 has a hitch body 4a with a U-shaped cross-section, a top link shaft 4b attached to the upper part of the hitch body 4a, and a lower link shaft 4c attached to the lower part of the hitch body 4a.

[0052] The work hitch device 4 is configured to be vertically rotatable, with the top link 6f connected to the top link shaft 4b and the lower link 6g connected to the lower link shaft 4c.

[0053] To elaborate further, the top link shaft 4b is a round bar with smaller diameters on both ends, and is rotatably connected to the top link 6f. The top link shaft 4b has stepped edges on both ends, giving it a tapered shape compared to a typical stepped pin. Pin-locking holes 4b1 are provided on both sides of the top link shaft 4b.

[0054] The lower link shaft 4c is a round bar of the same diameter as the top link shaft 4b, but with smaller diameters on both ends, and is rotatably connected to the lower link 6g. The lower link shaft 4c has stepped edges on both sides, and has a tapered shape compared to a normal stepped pin. Pin-locking holes 4c1 are provided on both sides of the lower link shaft 4c.

[0055] Holes 4b2 are provided on both sides of the bent surface of the hitch body 4a, which has a U-shaped cross-section, through which the top link shaft 4b passes. Holes 4c2 are provided on both sides of the bent surface of the hitch body 4a through which the lower link shaft 4c passes.

[0056] The lower part of the bent section of the hitch body 4a is notched to form a shape K, allowing for a shorter frame length and link length without interference. Holes 4f for attaching the engine bracket, which is a component of the work equipment, are provided on both sides of the bent surface of the hitch body 4a, above the axis center of the top link shaft 4b and at a position on the work equipment side. Furthermore, the bracket 4d, which has a vertical cross-section U-shape and is described below, is fixed in contact with the edges, which are the two parallel side end faces of the bent section of the hitch body 4a.

[0057] In other words, the hitch body 4a, which has a U-shaped cross-section, has a bracket 4d with a U-shaped vertical cross-section on its rear side, and a bearing piece 4e, as described later, is erected on the upper part of the bracket 4d. Furthermore, a hole 4d1 is drilled in the lower part of the bracket 4d, and this work hitch device 4 is attached to a predetermined location on the body of the work machine 7 using this hole.

[0058] In other words, to reiterate a part of the explanation, bracket 4d has a stay function for holding the work implement 7 and has a U-shaped bend. Bracket 4d is provided with multiple holes to accommodate all types of work implements. Specifically, bracket 4d has three holes 4d1 on both the upper and lower sides of the bend, which are common mounting holes for all work implements. Of the three lower holes 4d1, the middle hole 4d1 is often fixed with a single kingpin, and reinforcing round hole plates 4d1a are provided on both sides. Furthermore, reinforcing plates 4d1b are provided to reinforce bracket 4d.

[0059] Furthermore, a bearing piece 4e, which serves as both a guide and a stay, is provided to facilitate the attachment of the work implement 7 to the bracket 4d. The bearing piece 4e is provided on both sides of the bracket 4d, outside of the three holes 4d1 provided in the bracket 4d. This bearing piece 4e is shaped like a bent plate cut into short pieces, and has a notched hole 4e1 to guide and hold the pin on the work implement side, and its bending direction is set to face outwards from the machine body.

[0060] The vehicle body 1 is equipped with a battery, the running gear 2 is driven by an electric motor, and the tiller side is equipped with an internal combustion engine, and each can be controlled independently.

[0061] Furthermore, the implement of this invention is not limited to a tiller, but may be any other machine. [Industrial applicability]

[0062] This invention provides a work vehicle that prevents the implement from colliding with ridges or other obstacles when turning, making it ideal for tilling work. [Explanation of Symbols]

[0063] 1. Vehicle body 1a Mainframe 1b Plate component 1b1 hole 1b2 plate 1b2a hole 1c Cylinder mounting bracket 1c1 Plate component 1c1a, 1c1b hole 1c2 Plate Part 2. Traveling device 3. Crawler device 4. Work hitch device 4a Hitch body 4b Top link shaft 4b1, 4b2 hole 4c Lower Link Shaft 4c1, 4c2 hole 4D Bracket 4d1 hole 4d1a perforated plate 4d1b reinforcement plate 4f hole 5 Cylinder (Drive System) 5a Rod 6. Lift mechanism 6a Horizontal shaft 6a1 Support part 6a11 pin 6a2 Support member 6a3 tube 6b U-shaped bracket 6b1 tube 6c Lift Arm 6d L-shaped plate 6d1 bush 6d2 pin 6e Liftlink 6f Top Link 6f1, 6f2 holes 6g Lower Link 7. Work equipment K notch

Claims

1. The vehicle comprises a vehicle body, a traveling device that supports the vehicle body and allows it to move, and a work machine that rotates up and down by a lift mechanism provided on the vehicle body. A work vehicle characterized in that, within the working range of the work machine during operation, the work machine moves almost vertically up and down, and rotates above the working range.

2. The vehicle comprises a vehicle body, a traveling device that supports the vehicle body and allows it to move, and a work machine that rotates up and down by a lift mechanism provided on the vehicle body. A work vehicle characterized in that, within the working range of the work machine during operation, the lifting speed of the work machine is slower than the slewing speed above the working range.

3. The lift mechanism has a top link located above and a lower link located below. The aforementioned work implement is connected to the top link and lower link via a work hitch device. The work vehicle according to claim 1, wherein the length of the top link is shorter than the length of the lower link, and the pivot point (D) of the top link on the vehicle body side is located further back than the pivot point (A) of the lower link on the vehicle body side, with respect to the front-rear direction.

4. The length and position of the top link and the length and position of the lower link are determined when the work implement is in the lower limit position within the work range, the length of the lower link, the position of the pivot point (A) on the vehicle body side of the lower link and the pivot point (B) on the work hitch device side are determined, the position of the work hitch device is determined, the top link is made parallel to the lower link, the pivot point (C) on the work hitch device side of the top link is determined, and the pivot point (D) on the vehicle body side of the top link is determined at a position where the length of the top link is shorter than the length of the lower link, and is determined according to the distance from the lower limit position to the upper limit position within the work range, as described in claim 3.

5. The lift mechanism comprises a horizontal shaft rotatably supported by a support fixed to the main frame of the vehicle body; a U-shaped bracket rotatably connected at one end to a rod of a cylinder that is a drive mechanism and fixed at the other end to the horizontal shaft; a lower link whose front end is rotatably connected to the support and whose rear end is rotatably connected to the lower part of the work hitch device; a top link whose front end is directly or indirectly rotatably connected to the main frame of the vehicle body and whose rear end is rotatably connected to the upper part of the work hitch device; a lift arm whose front end is fixed to the horizontal shaft; and a lift link whose front end is rotatably connected to the rear end of the lift arm and whose rear end is rotatably connected to the central part of the lower link.

6. The work hitch device comprises a hitch body with a U-shaped cross-section, a top link shaft attached to the upper part of the hitch body and connected to the top link, and a lower link shaft attached to the lower part of the hitch body and connected to the lower link, wherein a bracket with a U-shaped cross-section is fixed in contact with two side end faces of the bent portion of the hitch body, a bearing piece is erected on the upper part of the bracket and a hole is drilled in the lower part, and the work hitch device is attached to a predetermined location on the body of the work machine using the bearing piece and the hole, as described in claim 5.

Images