JP7786677B2 - Wheel loader - Google Patents

Description

The present invention relates to a wheel loader equipped with a blade that scrapes snow off the ground, an edge that extends along the lower end of the blade and protrudes downward from the lower end of the blade to scrape the snow off the ground, and crushing claws that are positioned behind the edge.

Patent Document 1 discloses a cutting edge that is bolted to the bottom plate of a bucket and scrapes snow off the ground when clearing snow. A movable cutting body is fixed to the cutting edge and has a downward tip that is closer to the ground than the front end of the cutting edge. Patent Document 1 states that the downward tip of the movable cutting body can excavate ice on the ground. Here, it may be thought that the cutting edge scrapes snow off the road while the movable cutting body simultaneously excavates ice on the road surface.

JP 2012-7449 A Japanese Patent Application Publication No. 6-17410

Patent Document 1 states that because the movable cutting body tilts backward around the pin, damage to the road surface can be avoided even if the tip of the movable cutting body is positioned below the cutting edge. However, if the ice is hard, the ice cannot be cut by the tilt of the movable excavation body. On the other hand, if the spring's load capacity becomes too high to cut hard ice, the tip of the movable cutting body will remain below the cutting edge, and damage to the road surface cannot be avoided. Ultimately, the wheel loader described in Patent Document 1 can only be used for either snow removal or ice removal. Therefore, changing vehicles and attachments is unavoidable when switching between snow removal and ice removal.

The object of the present invention is to provide a wheel loader that can smoothly switch between snow removal and ice breaking without changing attachments.

One aspect of the present invention provides a wheel loader equipped with a blade that scrapes snow off the ground, an edge that extends along the lower end of the blade and protrudes downward from the lower end of the blade to scrape snow off the ground, and crushing claws that are positioned rearward of the edge and are positioned in an operating position closer to the ground than the edge, and in an inoperable position farther from the ground than the edge.

When a wheel loader pushes its blade against snow piled up on the road, the blade clears the snow from the road. To clear the snow, the edge scrapes the snow from the road. At this time, the crushing tines are set to the inoperative position, so the crushing tines are further from the road surface than the edge. This allows for effective snow removal. To break up ice, the crushing tines are switched from the inoperative position to the operative position. The crushing tines are closer to the road surface than the edge. The crushing tines can bite into the ice on the ground. In this way, the ice can be broken up effectively. It is possible to switch between snow removal and ice breaking up effectively without changing attachments. This significantly improves snow removal workability.

The wheel loader may also include a stopper structurally connected to the crushing tines in the operating position, which supports the reaction force acting from the ice to the crushing tines when crushing the ice. The reaction force during crushing can be effectively absorbed by the stopper. As a result, the ice can be effectively crushed.

The wheel loader may also be equipped with a hydraulic cylinder that has a rod connected to the crushing tines and that moves in and out of a cylinder case, driving the crushing tines between the inoperative position and the operative position. Because the hydraulic cylinder can maintain hydraulic pressure in both the inoperative and operative positions, the crushing tines can be fixed in both the inoperative and operative positions. Even if an external force acts on the crushing tines, the positions of the crushing tines can be maintained properly.

The wheel loader may also include an attachment frame fixed to the blade, rotatably connected to the lift arm about a first horizontal axis, and supporting the cylinder case of the hydraulic cylinder rotatably about a second horizontal axis; a support extending parallel to the edge, supporting the crushing tines in a line parallel to the edge, and connected to the attachment frame rotatably about a third horizontal axis; and a drive arm fixed to the support and connected to the rod of the hydraulic cylinder at a position away from the third horizontal axis. The crushing tines can be displaced between an inoperative position and an operative position in response to the rotation of the support. Displacement of the crushing tines can be achieved with a simple structure. Because the blade, crushing tines, and hydraulic cylinder are commonly supported by the attachment frame, the blade, crushing tines, and hydraulic cylinder can be handled together when attaching or detaching the attachment frame. This allows for easy operability when replacing the attachment.

As described above, the present invention provides a wheel loader that can smoothly switch between snow removal and ice breaking without changing attachments.

1 is a diagram illustrating a schematic configuration of a wheel loader according to an embodiment of the present invention. FIG. FIG. FIG.

One embodiment of the present invention will be described below with reference to the accompanying drawings.

Figure 1 shows a schematic diagram of a wheel loader according to one embodiment of the present invention. The wheel loader 11 has a vehicle body 14 supported on the ground (road surface) GD by left and right front wheels 12 and left and right rear wheels 13. The vehicle body 14 has a front body 14a that supports the front wheels 12 rotatably about a horizontal axis, and a rear body 14b that is connected to the rear end of the front body 14a rotatably about a vertical axis Vx and supports the rear wheels 13 rotatably about the horizontal axis. The wheel loader 11 turns when the front body 14a and rear body 14b are displaced relative to each other about the vertical axis Vx.

Left and right lift arms 16 are attached to the front body 14a so that they can be raised and lowered around a horizontal axis 15. A hydraulic cylinder (not shown) is installed between the front body 14a and the lift arms 16. The lift arms 16 can be raised and lowered by extending the hydraulic cylinder. A hydraulic circuit that distributes hydraulic pressure from a hydraulic source is connected to the hydraulic cylinder. When the hydraulic cylinder extends or retracts, hydraulic pressure from the hydraulic source is supplied to the hydraulic cylinder from the hydraulic circuit.

An attachment 19 is connected to the front end of the lift arm 16 so as to be tiltable about a horizontal axis 18. A tilt mechanism 21 is connected to the attachment 19. The tilt mechanism 21 includes a bell crank 23 supported on the lift arm 16 at an intermediate position so as to be rotatable about a horizontal axis 22, a tilt link member 24 connecting the attachment 19 to the bell crank 23, and a hydraulic cylinder 25 installed between the bell crank 23 and the front body 14a. The tilt link member 24 has a first end connected to the bell crank 23 so as to be rotatable about a horizontal axis 26 at a position away from the intermediate position in the first direction, and a second end connected to the attachment 19 so as to be rotatable about a horizontal axis 27 at a position away from the rotation axis of the attachment 19 relative to the lift arm 16. The hydraulic cylinder 25 comprises a cylinder case 25a rotatably connected to the front body 14a about a horizontal axis 28 and defining a hydraulic chamber, and a rod 25b rotatably connected to the bell crank 23 about a horizontal axis 29 at a position away from the intermediate position in a second direction opposite the first direction, and which extends and retracts relative to the cylinder case 25a in response to the supply of hydraulic pressure. The tilt operation of the attachment 19 can be achieved by extending and retracting the hydraulic cylinder 25. When the hydraulic cylinder 25 extends and retracts, hydraulic pressure from the hydraulic source is supplied to the hydraulic cylinder 25 from the hydraulic circuit.

A cab 33 is installed on the rear body 14b, forward of the rear wheels 13. Behind the cab 33 are mounted a power source 34 that generates driving force transmitted to the front wheels 12 and rear wheels 13, and a hydraulic source (not shown) that is connected to the power source 34 and generates hydraulic pressure in response to the power supplied from the power source 34. An operator sits in the cab 33. The wheel loader 11 travels in response to operation by the operator. The tilt angle and height of the attachment 19 can be controlled based on operation by the operator.

As shown in Figures 2 and 3, the attachment 19 comprises a blade 41 that scrapes snow off the ground GD, an attachment frame 42 that is fixed to the blade 41 and connects the blade 41 to the lift arm 16, and an edge 43 that extends along the lower end of the blade 41 and protrudes downward from the lower end of the blade 41 to scrape snow off the ground GD. The blade 41 extends in the width direction of the wheel loader 11 and forms a curved surface 41a that, while standing upright, displaces forward toward the lower end and displaces forward toward the upper end. When the wheel loader 11 moves forward, the blade 41 uses the curved surface 41a to scrape snow that has accumulated on the road. The lower end of the blade 41 is bounded by a horizontal line.

As shown in FIG. 4, the attachment frame 42 has left and right first bearing bodies 45 that receive the shafts supported individually by the left and right lift arms 16, and a pair of second bearing bodies 46 that receive the shafts supported at the ends of the tilt link members 24. Each first bearing body 45 is individually connected to the lift arm 16 so as to be rotatable about the horizontal axis (first horizontal axis) 18. The second bearing body 46 is connected to the tilt link member 24 so as to be rotatable about the horizontal axis 27. The two second bearing bodies 46 cooperate to support one tilt link member 24.

A number of crushing claws 47 are attached to the attachment frame 42 and positioned behind the edge 43. The crushing claws 47 can be positioned in an operating position closer to the ground GD than the edge 43, and in an inoperable position farther from the ground GD than the edge 43. The crushing claws 47 are arranged in a row parallel to the edge 43. The lower ends of the crushing claws 47 are aligned on a horizontal line. Each crushing claw 47 can be formed in the same shape. All crushing claws 47 are commonly supported by a single support 48 extending parallel to the edge 43. All crushing claws 47 may be integrated into a single member.

A connecting body 51 is fixed to the attachment frame 42, supporting the support body 48 so that it can rotate freely around a horizontal axis (third horizontal axis) 49. The horizontal axis 49 is set parallel to the horizontal axis 18. The crushing claws 47 are driven in the forward and backward directions around the horizontal axis 49. In the operating position, the crushing claws 47 are positioned at the rearmost position within their range of displacement around the horizontal axis 49 and are maintained in a position that stands up from the ground GD. The crushing claws 47 bounce forward from the operating position around the horizontal axis 49 and are stored in the inoperable position.

The attachment frame 42 is formed with a stopper 53 that receives the swing arm 52 fixed to the support body 48. The swing arm 52 extends away from the horizontal axis 49. The stopper 53 prevents the support body 48 from rotating backward from the operating position, in the opposite direction to the forward rotation. Therefore, the reaction force acting on the crushing claws 47 from the ground GD as the wheel loader 11 moves forward can be effectively received by the stopper 53.

A hydraulic cylinder 55 is connected to the support 48. The hydraulic cylinder 55 comprises a cylinder case 55a supported on the attachment frame 42 above the horizontal axis 49 and rotatable about a horizontal axis (second horizontal axis) 56, and a rod 55b that moves in and out of the cylinder case 55a in response to the supply of hydraulic pressure. The tip of the rod 55b is connected to the swing arm 52 at a position away from the horizontal axis 49 and rotatable about a horizontal axis 57. When the hydraulic cylinder 55 retracts, the crushing claws 47 are positioned in the operating position about the horizontal axis 49. The swing arm 52 is received by a stopper 53. When the hydraulic cylinder 55 extends, the crushing claws 47 are displaced forward about the horizontal axis 49 and can be stored in the operating position.

Next, the operation of the wheel loader 11 will be explained. The wheel loader 11 can move forward using the driving force of the power source 34. Prior to snow removal, the blade 41 is positioned. By controlling the raising and lowering movement of the lift arm 16 and the tilting movement of the attachment 19, the blade 41 can be fixed in a predetermined position. When the position is fixed, the flow of hydraulic pressure to the associated hydraulic cylinder is stopped.

When the wheel loader 11 pushes the blade 41 against snow piled up on the road, the blade 41 scrapes the snow off the road. As the snow is being scraped off, the edge 43 scrapes the snow off the road. At this time, the crushing claws 47 are stored in the inoperative position. The hydraulic cylinder 55 is fully extended. The crushing claws 47 extend forward from the horizontal axis 49. The hydraulic cylinder 55 prevents the flow of hydraulic pressure, so the crushing claws 47 can be fixed in the inoperative position. A check valve may be connected to the hydraulic chamber of the hydraulic cylinder 55 to prevent hydraulic pressure.

In the inactive position, the crushing claws 47 are further from the road surface than the edges 43. While the edges 43 scrape away snow from the road, the crushing claws 47 can move away from the snow surface. This allows for effective snow removal.

The crushing claws 47 are positioned to crush the ice. The hydraulic cylinder 55 is fully retracted. The crushing claws 47 are driven around the horizontal axis 49 from the inoperative position to the operative position. The hydraulic cylinder 55 blocks the flow of hydraulic pressure, so the crushing claws 47 can be fixed in the operative position. The aforementioned check valve can be used to block the hydraulic pressure.

The attachment 19 is positioned relative to the ice. The raising and lowering movement of the lift arm 16 and the tilting movement of the attachment 19 are controlled. In this way, the crushing claws 47 are fixed in a predetermined position. The crushing claws 47 are closer to the ground GD than the edge 43. The crushing claws 47 are maintained in a state where they stand up from the surface of the ice. When the wheel loader 11 moves forward, the crushing claws 47 dig into the ice from the surface. In this way, the ice is crushed by the action of the crushing claws 47. The reaction force acting from the ice on the crushing claws 47 during crushing can be effectively absorbed by the stopper 53 around the horizontal axis 49.

Once the ice has been broken up, the breaking claws 47 can be stored back into the inoperative position. The function of the wheel loader 11 can then be switched back to snow removal. Prior to snow removal, the blade 41 is positioned. As the wheel loader 11 pushes the blade 41 against the snow that has accumulated on the road, the blade 41 scrapes the snow off the road. In this way, snow removal and ice breaking can be smoothly switched over without changing attachments. This significantly improves snow removal workability.

In the wheel loader 11 according to this embodiment, the crushing tines 47 are driven between the inoperative and operative positions by the hydraulic cylinder 55. Because the hydraulic cylinder 55 can maintain hydraulic pressure in both the inoperative and operative positions, the crushing tines 47 can be fixed in both the inoperative and operative positions. Even if an external force acts on the crushing tines 47, the position of the crushing tines 47 can be maintained well.

In this embodiment, the crushing claws 47 can be displaced between an inoperative position and an operative position in response to the rotational movement of the support body 48. The displacement of the crushing claws 47 can be achieved with a simple structure. Because the blade 41, crushing claws 47, and hydraulic cylinder 55 are commonly supported by the attachment frame 42, the blade 41, crushing claws 47, and hydraulic cylinder 55 can be handled together when the attachment frame 42 is attached or detached. This allows for good workability when replacing the attachment 19.

In this embodiment, the reaction force acting on the crushing claws 47 from the ice barn during crushing can be effectively received by the stoppers 53 around the horizontal axis 49. In this way, the reaction force during crushing can be structurally supported. The hydraulic cylinder 55 can be freed from supporting the reaction force. Therefore, the hydraulic cylinder 55 can be made smaller. On the other hand, when the crushing claws 47 are retracted rearward around the horizontal axis 49, the hydraulic cylinder 55 must support the reaction force from behind the crushing claws 47 during crushing, so it is unavoidable to make the hydraulic cylinder 55 stronger, i.e., larger.

11...wheel loader, 16...lift arm, 18...first horizontal axis (horizontal axis), 41...blade, 42...attachment frame, 43...edge, 47...crushing claw, 48...support, 49...third horizontal axis (horizontal axis), 52...drive arm (swing arm), 55...hydraulic cylinder, 55a...cylinder case, 55b...rod, 56...second horizontal axis (horizontal axis), GD...ground.

Claims (4)

A blade that clears away snow from the ground,
an edge extending along the lower end of the blade and projecting downward from the lower end of the blade for scraping snow off the ground;
an attachment frame fixed to the blade and connecting the blade to a lift arm;
A crushing claw is disposed behind the edge and positioned at an operating position closer to the ground than the edge and at a non-operating position farther from the ground than the edge ;
a stopper formed on the attachment frame, structurally connected to the crushing claws in the operating position, and configured to support a reaction force acting from the ice barn to the crushing claws when crushing the ice barn;
A wheel loader comprising: 2. The wheel loader according to claim 1 , further comprising a hydraulic cylinder having a rod connected to the crushing tines and extending into and out of a cylinder case, the hydraulic cylinder driving the crushing tines between the inoperative position and the operative position. 3. The wheel loader according to claim 2 , wherein the attachment frame is connected to the lift arm so as to be rotatable about a first horizontal axis, and supports the cylinder case of the hydraulic cylinder so as to be rotatable about a second horizontal axis. The wheel loader according to claim 3,
a support extending parallel to the edge and supporting the crushing claws in a row parallel to the edge, the support being connected to the attachment frame so as to be rotatable about a third horizontal axis;
a drive arm fixed to the support and connected to the rod of the hydraulic cylinder at a position spaced apart from the third horizontal axis.