Bed lifting device

Abstract

To provide a load carrying platform lifting unit capable of relatively suppressing a height of a load carrying platform lifting unit, and securing a required height of a load carrying platform when the same is lifted up.SOLUTION: A load carrying platform lifting unit comprises: a load carrying platform 6; support frames 11A, 11B; arms 13A, 13B; a rotary shaft part 52 for rotatably supporting the load carrying platform 6 in a direction where the same is tilted to a rear part; and actuators 12A, 12B whose lower ends are supported by the support frames 11A, 11B, and whose upper ends are supported by the load carrying platform 6, and which lift up and rotate the load carrying platform 6 by extension / shrinkage. The actuators 12A, 12B lift up the load carrying platform 6 by extension, for arranging the load carrying platform 6 on a lifted position to which arms 13A, 13B slide and which is an upper limit position, and at the lifted position of the load carrying platform 6, by further extension of the actuators 12A, 12B, the load carrying platform 6 is rotated around the rotary shaft part 52 as a center of rotary, for arranging the load carrying platform 6 in a posture state at which the load carrying platform is tilted to a rear part.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a loading platform lifting device that lifts and rotates a loading platform. [Background technology]

[0002] As this type of bed lifting device, one that includes a frame that supports the bed via a link mechanism so that a so-called side dump can be performed by tilting the bed sideways, and slide rotation support parts that are arranged at the front and rear of the bed and that raise and lower the bed as well as rotate it, and an actuator that is provided so as to be extendable and retractable (see Patent Document 1). In this bed lifting device, the fixed part of the rotation shaft of the bed is an elongated hole, and when the bed is raised by the actuator, the rotation shaft slides and rises in the elongated hole, and the load is discharged from the bed from a position that is higher by the length of the elongated hole. Another device that includes a support provided vertically at the rear end of the vehicle body, a guide member that rises and falls along the support, and a hydraulic cylinder, in which the guide member rotatably supports the rear end of the bed, and the bed is raised and lowered by the extension and retraction of the hydraulic cylinder (see Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-112903 A [Patent Document 2] Japanese Patent Application Publication No. 58-431 Summary of the Invention [Problem to be solved by the invention]

[0004] In the bed lifting device described in Patent Document 1, for example, when the bed is rotated when loading the load on the bed onto a transport vehicle such as a truck, the open end of the bucket may lower during rotation and come into contact with the tailgate of the transport vehicle. In addition, when the bed is raised, the top end of the bed lowers, which may cause the top end of the bed to interfere with the top of the tailgate. In addition, the height to the top end of the bed of the bed lifting device is increased by the length of the long hole in the bed, which may cause the upper limit of the loading height to be exceeded when a harvester equipped with the bed lifting device is loaded onto a transport vehicle and moved, or the harvester may not be able to be stored in an agricultural machinery shed.

[0005] Furthermore, in the bed lifting device described in Patent Document 2, the height to the top of the bed of the bed lifting device is increased by the height of the support body mounted vertically at the rear end of the vehicle body, which means that when a harvester equipped with the bed lifting device is loaded onto a transport vehicle and moved, there is a risk that the upper limit of loading height will be exceeded, or that the harvester cannot be stored in an agricultural machinery shed.

[0006] The present invention has been made to solve such problems, and has as its object to provide a loading platform lifting device that can keep the height of the loading platform lifting device itself relatively low and ensure the required loading platform height when the loading platform is raised. [Means for solving the problem]

[0007] (1) The loading platform lifting device of the present invention comprises a loading platform, support frames arranged in opposing positions across the loading platform, an arm protruding upward from the support frame and supported so as to be slidable up and down, a pivot shaft section provided at the tip of the arm and supporting the loading platform so as to be rotatable around the tip of the arm as a pivot center in a direction tilting the loading platform to the rear of the loading platform, and an actuator arranged at a position further forward of the loading platform than the arm, having a lower end supported by the support frame and an upper end supported by the loading platform, and raising and lowering and rotating the loading platform by extending and contracting, wherein the actuator raises the loading platform by extending the actuator and slides the arm to position the loading platform at an upper limit raised position, and at the raised position of the loading platform, further extension of the actuator rotates the loading platform around the pivot shaft section as a pivot center to position the loading platform in a position tilted to the rear of the loading platform.

[0008] (2) The loading platform lifting device according to the present invention is characterized in that the actuator has an upper end supported between the center of gravity of the loading platform and the pivot shaft portion.

[0009] (3) The loading platform lifting device of the present invention is characterized in having a lifting guide that supports the loading platform, which rises and falls due to the extension and contraction of the actuator, in a constant posture and guides it between the lowered position and the raised position.

[0010] (4) The loading platform lifting device of the present invention is characterized in that the arm has a plurality of upper limit positioning holes spaced at predetermined intervals in the sliding movement direction, the support frame has an elongated hole through which the plurality of upper limit positioning holes are exposed along the sliding movement direction of the arm, and a positioning pin is inserted into one of the plurality of upper limit positioning holes through the elongated hole.

[0011] (1) According to the loading platform lifting device of the present invention, the loading platform is raised by extending the actuator, and the loading platform can be raised to a raised position in this posture by sliding the arm upward. When the loading platform reaches the raised position, the actuator is further extended to rotate the loading platform around the pivot shaft, and the loading platform can be placed in a posture tilted backward. This allows, for example, the loading platform to be raised with a load on it, and the loading platform can be rotated backward at the raised position to discharge the load on the loading platform to the rear of the loading platform. The actuator is then contracted by the load of the loading platform or by the actuator being actuated, and the loading platform is rotated around the pivot shaft, and the loading platform is brought from its posture tilted backward to a horizontal posture. The actuator is then further contracted, and the arm slides downward, and the loading platform, the actuator, and the arm return to their original positions, and the loading platform becomes ready for loading.

[0012] (2) In the bed lifting device according to the present invention, the actuator has an upper end supported between the center of gravity of the bed and the pivot shaft. Therefore, the actuator extends to lift the bed first and then rotates it toward the rear of the bed at the lifted position. The actuator contracts to rotate the bed first at the lifted position to a horizontal position and then lower it.

[0013] (3) The bed lifting device according to the present invention has a lifting guide that supports the bed, which rises and falls due to the extension and contraction of the actuator, in a constant position and guides it between the lowered position and the raised position. This configuration makes it possible to prevent the bed from rotating while it is being raised or lowered, and to maintain it in a stable position.

[0014] (4) In the loading platform lifting device of the present invention, the arm is provided with a plurality of upper limit positioning holes at a predetermined interval in the sliding movement direction, and the support frame is provided with an elongated hole through which the plurality of upper limit positioning holes are exposed along the sliding movement direction of the arm, and a positioning pin is inserted into one of the plurality of upper limit positioning holes through the elongated hole.

[0015] With this configuration, the positioning pin rises and falls within the insertion hole as the arm rises and falls, and at the same time the pivot shaft of the arm reaches a predetermined raised position, the positioning pin abuts against the inner wall of the upper end of the elongated hole. When the positioning pin abuts against the inner wall of the upper end of the elongated hole, the positioning pin is prevented from rising, and the arm is prevented from rising. Since the upper limit position of the arm can be adjusted by the positioning pin, the height to which the loading platform rises can be adjusted according to the height of the transport vehicle carrying the load. Effect of the Invention

[0016] According to the present invention, it is possible to provide a loading platform lifting device that can lift the loading platform to a required height and tilt it backward in the lifted position to discharge the loaded items. [Brief description of the drawings]

[0017] [Figure 1] 1 is a side view of a harvester equipped with a bed lifting device according to an embodiment of the present invention. [Diagram 2] 1 is a front view of a bed lifting device according to an embodiment of the present invention, showing a state in which the bed has been lowered to its lowest position. [Diagram 3] 3A and 3B are diagrams of a loading platform lifting device according to an embodiment of the present invention, showing a state in which the loading platform is lowered to the lowest position, FIG. 3A being a plan view and FIG. 3B being a left side view. [Figure 4] 3(b) is a cross-sectional view of the platform lifting and lowering device according to the embodiment of the present invention; FIG. [Diagram 5] 1 is a perspective view of a bed lifting device according to an embodiment of the present invention, showing a state in which the bed is lowered to a lowest position. [Figure 6] 1 is an exploded perspective view of a bed lifting device according to an embodiment of the present invention; [Figure 7]7A and 7B are cross-sectional views of the loading platform lifting and lowering device according to the embodiment of the present invention, with FIG. 7A showing the AA cross section in FIG. 2 and FIG. 7B showing the BB cross section in FIG. [Figure 8] 8A and 8B are diagrams of a bed lifting device according to an embodiment of the present invention, showing a state in which the bed is in the middle of being lifted, FIG. 8A being a left side view, and FIG. 8B being a front view. [Figure 9] 1 is a perspective view of a bed lifting device according to an embodiment of the present invention, showing a state in which the bed is in the middle of being lifted. [Figure 10] 10A and 10B are diagrams of a loading platform lifting device according to an embodiment of the present invention, showing a state in which the loading platform is raised to the uppermost position, FIG. 10(a) being a left side view, and FIG. 10(b) being a front view. [Figure 11] 1 is a perspective view of a bed lifting device according to an embodiment of the present invention, showing a state in which the bed is lifted to the uppermost position. [Figure 12] 1 is a side view of a bed lifting device according to an embodiment of the present invention, showing a state in which the bed loaded with agricultural products has been raised to the uppermost position and the agricultural products are being dropped onto a truck. [Figure 13] 1 is a perspective view of a bed lifting device according to an embodiment of the present invention, showing a state in which a bed loaded with agricultural products is raised to the uppermost position and the agricultural products are dropped onto a truck. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] A bed lifting / lowering device 7 according to an embodiment in which the bed lifting / lowering device according to the present invention is applied to a harvester 1 will be described with reference to the drawings.

[0019] First, the configuration of a harvester 1 equipped with a platform lifting device 7 according to this embodiment will be described. As shown in FIG. 1, the harvester 1 is composed of a vehicle body 2, a traveling device 3, a driving device 4, a harvesting device 5, a loading platform 6, a loading platform lifting device 7, and an operating unit (not shown) that operates the raising and lowering of the loading platform 6 by the loading platform lifting device 7.

[0020] The harvester 1 is configured to harvest crops such as rice and corn planted in a field while traveling, chop the crops, and load them onto a loading platform 6, which is then loaded onto a transport vehicle such as a 2-ton or 4-ton truck. The harvested crops are used, for example, as livestock feed, and are transported by the transport vehicle to a feed base.

[0021] The vehicle body 2 is, for example, a frame structure vehicle body having a frame connected by highly rigid vertical and horizontal frames, and is configured to support each component. The traveling device 3 is connected to the vehicle body 2 and is configured of an endless track that is rotationally driven to absorb unevenness of rough traveling surfaces such as farm fields and to be able to turn and steer in the forward / backward / left / right directions.

[0022] The driving device 4 is fixed to the front of the vehicle body 2, and is configured to include a steering mechanism (not shown) such as a steering handle for steering the traveling device 3. The harvesting device 5 is configured to harvest and shred agricultural crops planted in the field, and discharge the crops into a loading platform 6.

[0023] The loading platform 6 is disposed behind the driving device 4 of the harvester 1 as shown in Fig. 1, and is composed of a box body 6a with an open upper surface in the vertical direction when in a horizontal state, and left and right sliding bodies 6b fixed to the box body 6a and sliding relative to the loading platform lifting device 7 as shown in Figs. 3(a), 3(b), 5, 7(b) and 9. The loading platform 6 is connected to the loading platform lifting device 7 as shown in Figs. 2, 3(a), 3(b) and 5, and is configured to be raised and lowered by the loading platform lifting device 7 and to rotate. Agricultural products harvested by the harvesting device 5 are loaded onto the loading platform 6.

[0024] As shown in FIG. 1, the bed lifting device 7 is fixed to the rear of the vehicle body 2 of the harvester 1, and as shown in FIG. 2, FIG. 3(a), FIG. 3(b), and FIG. 6, the bed lifting device 7 is composed of support frames 11A, 11B, actuators 12A, 12B, arms 13A, 13B, guide rollers 14A, 14B, lifting guides 15A, 15B, and a controller (not shown). In the following description, the terms "up" and "down" refer to the upper and lower sides of the harvester 1 when the bed lifting device 7 is mounted on the harvester 1 shown in FIG. 1, and the terms "left" and "right" refer to the left and right sides as viewed from the rear of the harvester 1. Although the bed lifting device 7 is composed of support frames 11A and 11B, the bed lifting device according to the present invention may be composed of a single support frame.

[0025] As shown in Fig. 5, the support frame 11A is attached to the left side surface portion, which is one side surface portion, of the cargo bed 6. As shown in Fig. 6, the support frame 11A is composed of a left side plate 21, a right side plate 22, a left reinforcing plate 23, a right reinforcing plate 24, a left reinforcing frame 25, a right reinforcing frame 26, connecting members 27 and 28, an upper connecting member 31, and a lower connecting member 32. Each component is made of a metal material and has high mechanical strength.

[0026] The left side plate 21 is made up of a support portion that extends in the vertical direction and supports the actuator 12A and the arm 13A, and a mounting portion that extends perpendicular to the vertical direction and is attached to the vehicle body 2 of the harvester 1. Four mounting holes 21a for mounting an upper guide roller 61 (described later) of the guide roller 14A and four mounting holes 21b for mounting a lower guide roller 62 are formed through the support portion of the left side plate 21.

[0027] Further, an elongated hole 21c for inserting the left reinforcing frame 25 and a mounting hole 21d for mounting the actuator 12A are formed penetrating the support portion of the left side plate 21. Three mounting holes 21e for mounting the support frame 11A to the vehicle body 2 and three fixing holes 21f for fixing the lower connecting member 32 are formed penetrating the mounting portion of the left side plate 21.

[0028] Similar to the left side plate 21, the right side plate 22 is made up of a support portion that extends in the vertical direction and supports the actuator 12A and the arm 13A, and a mounting portion that extends perpendicular to the vertical direction and is attached to the body 2 of the harvester 1. Four mounting holes 22a for mounting upper guide rollers 61 (described later) of the guide roller 14A and four mounting holes 22b for mounting lower guide rollers 62 are formed through the support portion of the right side plate 22.

[0029] Further, an elongated hole 22c for inserting the right reinforcing frame 26 and a mounting hole 22d for mounting the actuator 12A are formed penetrating the support portion of the right side plate 22. Three mounting holes 22e for mounting the support frame 11A to the vehicle body 2 and three fixing holes 22f for fixing the lower connecting member 32 are formed penetrating the mounting portion of the right side plate 22.

[0030] The left reinforcing plate 23 is formed in a substantially triangular shape, and has a mounting hole 23a formed therethrough for mounting the actuator 12A. The left reinforcing plate 23 is joined to the side surface of the left side plate 21 facing the right side plate 22 by a joining means such as welding.

[0031] The right reinforcing plate 24, like the left reinforcing plate 23, is formed in a substantially triangular shape, and has a mounting hole 24a formed therethrough for mounting the actuator 12A. The right reinforcing plate 24 is joined to the side surface of the right side plate 22 facing the left side plate 21 by a joining means such as welding.

[0032] Left reinforcing frame 25 has both longitudinal ends formed in a semicircular shape, and has elongated holes 25a formed therethrough, into which positioning pins 54 of arm 13A (described later) are inserted. Left reinforcing frame 25 is inserted into elongated holes 21c in left side plate 21, and joined to left side plate 21 by joining means such as welding.

[0033] Similar to the left reinforcing frame 25, the right reinforcing frame 26 has both longitudinal ends formed in a semicircular shape and is formed with an elongated hole 26a through which a positioning pin 54 of the arm 13A described later is inserted. The right reinforcing frame 26 is inserted into an elongated hole 22c in the right side plate 22 and joined to the right side plate 22 by joining means such as welding.

[0034] As shown in Figs. 4 and 6, the connecting member 27 is made of a channel steel material having a U-shaped cross section, and is joined to the side surface of the left side plate 21 facing the right side plate 22 by joining means such as welding. The connecting member 27 is provided so as to extend vertically along the end of the left side plate 21, and connects the left side plate 21 and the right side plate 22, respectively. The connecting member 28 is a mirror image of the connecting member 27 and is formed in the same manner, is disposed opposite the connecting member 27, and is joined to the side surface of the right side plate 22 facing the left side plate 21 by joining means such as welding. The connecting member 28 is also provided so as to extend vertically along the end of the right side plate 22, and connects the left side plate 21 and the right side plate 22, respectively. The connecting member 28 may be formed in the same shape as the connecting member 27.

[0035] The upper connecting member 31 is made of a rectangular plate material and has a rectangular through-hole 31a formed therein for passing the arm 13A therethrough. The upper connecting member 31 connects an upper end of a support portion of the left side plate 21 that supports the arm 13A to an upper end of a support portion of the right side plate 22 that supports the arm 13A. The upper connecting member 31 is joined to the upper end of the left side plate 21 and the upper end of the right side plate 22 by a joining means such as welding.

[0036] The lower connecting member 32 is made of a rectangular rod-shaped member, and has a plurality of through holes 32a formed on its side for passing fastening members (not shown). The lower connecting member 32 connects the left side plate 21 and the right side plate 22 by passing fastening members (not shown) through fixing holes 21f in the mounting portion of the left side plate 21 and fixing holes 22f in the mounting portion of the right side plate 22.

[0037] 5, the support frame 11B is attached to the right side portion, which is the other side portion, of the platform 6, and is configured similarly to the support frame 11A. The support frame 11B is fixed to the vehicle body 2 of the harvester 1.

[0038] 5, the actuator 12A is a mechanism for raising and lowering the platform 6 by extending and contracting, for example, a hydraulic mechanism, and is connected to a controller, and the raising and lowering operation is controlled by the controller. The actuator 12A is configured to extend when hydraulic pressure is supplied and to contract due to the weight of the platform 6.

[0039] The actuator 12A has a stroke for rotating the platform 6 about the rotating shaft portion 52 by further extending when the tip of the arm 13A reaches a predetermined upper limit position.

[0040] 6, the actuator 12A is composed of a hydraulic cylinder 41, a piston rod 42, an upper end support part 43 connected to the left side part of the platform 6, a fixing pin 44, a pin fixing device 45, and a hydraulic supply device (not shown). The hydraulic supply device is connected to a controller, and is configured so that the hydraulic supply is controlled by the controller.

[0041] The hydraulic cylinder 41 is formed in a cylindrical shape, and accommodates the piston rod 42 so as to be freely reciprocating. A single-acting hydraulic cylinder is used in which hydraulic pressure is supplied from a hydraulic supply device to extend the piston rod 42. The piston rod 42 of the hydraulic cylinder 41 is contracted by the weight of the loading platform 6. In this embodiment, a single-acting hydraulic cylinder 41 is used, but a double-acting hydraulic cylinder in which the piston rod 42 is extended and contracted by the supply of hydraulic pressure may also be used. The single-acting hydraulic cylinder can simplify the configuration of the hydraulic circuit compared to the double-acting hydraulic cylinder. The hydraulic cylinder 41 is formed with an insertion hole 41a through which a fixing pin 44 is inserted, and is supported rotatably on the support frame 11A via the fixing pin 44 inserted into the insertion hole 41a.

[0042] The piston rod 42 is connected at its upper end to an upper end support portion 43 that supports the loading platform 6 so that it can rotate freely, and the reciprocating movement of the piston rod 42 is transmitted to the loading platform 6 via the upper end support portion 43, causing the loading platform 6 to rise and fall.

[0043] The upper end support part 43 is composed of a fixed part 43a fixed to the loading platform 6, a connecting part 43b connected to the upper end of the piston rod 42, and a connecting pin 43c connecting the fixed part 43a and the connecting part 43b so as to be rotatable relative to each other. As the piston rod 42 extends and contracts, the connecting part 43b rotates relative to the fixed part 43a.

[0044] Like the actuator 12A, the actuator 12B is made up of a hydraulic mechanism and is connected to a controller so that its extending and contracting operations are controlled by the controller. The actuator 12B is made up of a hydraulic cylinder 41, a piston rod 42, a pin fixing device 45, and a hydraulic supply device (not shown). The hydraulic supply device is connected to the controller so that the hydraulic supply is controlled by the controller. 。

[0045] 5 and 6, arm 13A has a main body 51, a rotating shaft portion 52, and a flange 53. Main body 51 of arm 13A is provided with a positioning hole 51a into which a positioning pin 54 is inserted through elongated hole 25a of left reinforcing frame 25. Arm 13A slides upward and positioning pin 54 abuts against the inner wall of the upper end of elongated hole 25a, thereby reaching the upper limit of movement and preventing further upward sliding movement.

[0046] That is, when the actuator 12A extends and the platform 6 starts to rise, the arm 13A slides upward accordingly. When the actuator 12A contracts and the platform 6 starts to fall, the arm 13A slides downward accordingly.

[0047] The main body 51 is made of a rod-shaped member having a square cross section, and a plurality of upper limit positioning holes 51a into which positioning pins 54 are inserted are formed penetrating the lower part. The plurality of upper limit positioning holes 51a are provided at predetermined intervals from one another in the longitudinal direction of the main body 51, and are designed so that the positioning pins 54 can be inserted through the elongated holes 25a of the left reinforcing frame 25.

[0048] The pivot shaft 52 is composed of a fixed portion 52a fixed to the loading platform 6, a connecting portion 52b connected to the upper end of the main body 51, and a connecting pin 52c connecting the fixed portion 52a and the connecting portion 52b so as to be freely rotatable relative to each other.

[0049] The flange 53 is made of a rectangular plate material having the same shape as the upper connecting member 31 of the support frame 11A. The flange 53 is joined to the upper end of the main body 51 by a joining means such as welding, and the connecting portion 52b of the rotating shaft portion 52 is fixed to the upper surface of the flange 53. The flange 53 has a size that allows it to come into contact with the upper connecting member 31 of the support frame 11A and close the through hole 31a when the main body 51 is in a lowered state in order to prevent foreign matter such as straw from entering through a gap between the main body 51 and the through hole 31a of the upper connecting member 31.

[0050] The positioning pin 54 is made of a rod-shaped member having a circular cross section, and is inserted into one of the multiple upper limit positioning holes 51a of the main body 51 through the elongated hole 25a of the left reinforcing frame 25. The positioning pin 54 is in a state in which its tip portion passes through the upper limit positioning hole 51a and is positioned in the elongated hole 26a of the right reinforcing frame 26, its central portion is positioned in one of the multiple upper limit positioning holes 51a, and its base end portion is positioned in the elongated hole 25a of the left reinforcing frame 25.

[0051] When the main body 51 slides upward, the positioning pin 54 simultaneously abuts against the inner wall of the upper end of the elongated hole 25a of the left reinforcing frame 25 and the inner wall of the upper end of the elongated hole 26a of the right reinforcing frame 26, thereby preventing the main body 51 from rising. When the positioning pin 54 is inserted into the lowermost upper limit positioning hole 51a of the multiple upper limit positioning holes 51a of the main body 51, the distance until the positioning pin 54 abuts against the inner wall of the upper end of the elongated hole 25a of the left reinforcing frame 25 and the inner wall of the upper end of the elongated hole 26a of the right reinforcing frame 26 becomes the longest, and the main body 51 can be slid to the highest position.

[0052] Conversely, when the positioning pin 54 is inserted into the uppermost upper limit positioning hole 51a among the multiple upper limit positioning holes 51a of the main body 51, the distance until the positioning pin 54 abuts against the inner wall of the upper end of the elongated hole 25a of the left reinforcing frame 25 and the inner wall of the upper end of the elongated hole 26a of the right reinforcing frame 26 is the shortest, and the main body 51 can be prevented from rising at the lowest position. In other words, by selecting the position of the multiple upper limit positioning holes 51a into which the positioning pin 54 is inserted, the upper limit position caused by the sliding movement of the main body 51 can be adjusted.

[0053] For example, when discharging a load loaded on the bed 6 onto the bed of a transport vehicle such as a 2-ton truck with a relatively low vehicle height, the positioning pin 54 is inserted into the uppermost upper limit positioning hole 51a among the multiple upper limit positioning holes 51a in the main body 51. On the other hand, when discharging a load loaded on the bed 6 onto the bed of a transport vehicle such as a 4-ton truck with a relatively high vehicle height, the positioning pin 54 is inserted into the lowermost upper limit positioning hole 51a among the multiple upper limit positioning holes 51a in the main body 51.

[0054] Similar to arm 13A, arm 13B has a main body 51, a rotating shaft portion 52, and a flange 53. When main body 51 of arm 13B starts to slide upward and positioning pin 54 abuts against the inner wall of the upper end of elongated hole 26a, arm 13B reaches the upper limit of its movement and is prevented from sliding any further upward.

[0055] 2, 6, and 7(a), the guide roller 14A is composed of an upper guide roller 61 and a lower guide roller 62. The upper guide roller 61 is composed of four rollers, and each roller is rotatably attached with both ends supported by the mounting holes 21a of the left side plate 21 and the mounting holes 22a of the right side plate 22. The rollers come into contact with the side surface of the main body 51 of the arm 13A, and guide the main body 51 so as to be slidable up and down.

[0056] The lower guide rollers 62, like the upper guide rollers 61, are made up of four rollers, and each roller is rotatably attached with both ends supported by the mounting holes 21b of the left side plate 21 and the mounting holes 22b of the right side plate 22. The lower guide rollers 62 come into contact with the side surfaces of the main body 51 of the arm 13A, and guide the main body 51 so as to be slidable up and down.

[0057] The lower guide roller 62 is spaced apart from the upper guide roller 61 in the moving direction of the main body 51, and is located at the lower part of the arm 13A. The upper guide rollers 61 and the lower guide rollers 62 may each be two, not four, or six or more. The guide roller 14B is configured similarly to the guide roller 14A.

[0058] 2 and 6, the lifting guide 15A is composed of an attachment portion 71 and a guide portion 72, and is joined to the right side of the right side plate 22 of the actuator 12A at the attachment portion 71 by a joining means such as welding. The guide portion 72 abuts against a sliding body 6b provided on the platform 6 and guides the sliding body 6b while the platform 6 is lifting or lowering. The lifting guide 15A guides the sliding of the sliding body 6b, thereby maintaining the posture of the platform 6 in a horizontal posture perpendicular to the vertical direction when the platform 6 is lifted or lowered.

[0059] Like the lift guide 15A, the lift guide 15B is composed of an attachment portion 71 and a guide portion 72, and as shown in Figures 5 and 7(b), the attachment portion 71 is joined to the left side surface of the left side plate 21 of the actuator 12B by a joining means such as welding.

[0060] The controller is configured by a known microcomputer having a memory such as a ROM that stores setting value information such as calculation programs and data, and a processor that executes processing according to the program. The controller is connected to a hydraulic supply device for the actuators 12A, 12B, and controls the lifting and lowering operations of the actuators 12A, 12B by controlling the hydraulic supply operation of the hydraulic supply device. The controller may be configured by a relay circuit.

[0061] The lifting and lowering operation of the platform lifting and lowering device 7 according to this embodiment and the loading operation onto a truck will now be briefly described with reference to the drawings.

[0062] When the loading platform 6 of the harvester 1 is filled with harvested crops, the harvester 1 travels to a location where the load is discharged, such as an access road to the field, and stops at a position close to a transport vehicle, such as a 2-ton or 4-ton truck, that transports the load discharged from the loading platform 6 and suitable for loading the load on the loading platform 6 onto the loading platform of the transport vehicle.

[0063] When the harvester 1 is in a stopped state and an operation is performed on the operation unit of the harvester 1 to start the operation of the bed lifting device 7, the controller of the bed lifting device 7 supplies hydraulic pressure from the hydraulic supply device to the actuators 12A, 12B, and the extension of the piston rod 42 begins. When the piston rod 42 extends, the bed 6 rises. The left and right sliding bodies 6b of the bed 6 are guided by the lifting guides 15A, 15B, respectively, and the bed 6 rises while maintaining a horizontal position.

[0064] 8(a), 8(b), and 9, arms 13A and 13B slide upward as platform 6 rises. When arms 13A and 13B slide upward and position positioning pin 54 simultaneously contacts the inner wall of the upper end of slot 25a in left reinforcing frame 25 and the inner wall of the upper end of slot 26a in right reinforcing frame 26, arms 13A and 13B are prevented from sliding upward and platform 6 is held in the raised position.

[0065] With the platform 6 in the raised position, the actuators 12A and 12B continue to extend further.

[0066] This extension of actuators 12A, 12B causes platform 6 to rotate toward the rear of the platform around pivot shaft 52. As shown in Fig. 11, extension of actuators 12A, 12B stops and rotation of platform 6 stops at a position where upper end support portion 43 does not pass in the rotation direction vertical line L passing through the rotation center of pivot shaft portion 52 shown in Fig. 10(a). When platform 6 rotates and assumes a position tilted toward the rear, agricultural products in platform 6 fall into the center of the platform of a transport vehicle such as a 4-ton truck as shown in Figs. 12 and 13.

[0067] When the agricultural products in the loading platform 6 fall onto the loading platform of a transport vehicle such as a 4-ton truck, and an operation is performed on the operating section of the harvester 1 to start the return movement of the loading platform lifting device 7, the actuators 12A and 12B contract and rotate in a direction to return the loading platform 6 to a horizontal position. Then, when the loading platform 6 is returned to the horizontal position at the raised position, the actuators 12A and 12B further contract, and the left and right sliding bodies 6b of the loading platform 6 are guided by the lifting guides 15A and 15B, respectively, and the loading platform 6 descends while maintaining the horizontal position, returning to the original position shown in Figures 3(a), 3(b), and 5, and the lifting movement of the loading platform lifting device 7 ends.

[0068] The effects of the platform lifting and lowering device 7 according to this embodiment will be described with reference to the drawings. (1) The loading platform lifting device 7 of the embodiment comprises a loading platform 6, support frames 11A, 11B arranged in positions facing each other with the loading platform 6 in between, arms 13A, 13B protruding upward from the support frames 11A, 11B and supported so as to be able to slide up and down, a pivot shaft portion 52 provided at the ends of the arms 13A, 13B and supporting the loading platform 6 so as to be able to rotate in a direction tilting the loading platform 6 to the rear of the loading platform, with the ends of the arms 13A, 13B as the pivot center, and actuators 12A, 12B arranged at a position further forward of the loading platform 6 than the arms 13A, 13B, with their lower ends supported by the support frames 11A, 11B and their upper ends supported by the loading platform 6, and which raise and lower and rotate the loading platform 6 by extending and contracting. The actuators 12A, 12B are configured to raise the loading platform 6 by extending the actuators 12A, 12B, and position the loading platform 6 at an upper limit raised position to which the arms 13A, 13B slide, and at the raised position of the loading platform 6, the actuators 12A, 12B are further extended to rotate the loading platform 6 around the pivot shaft portion 52 as the rotation center, thereby positioning the loading platform 6 in a tilted position toward the rear of the loading platform.

[0069] Therefore, all of the cargo loaded on the loading platform 6 can be discharged from the loading platform 6. When all of the cargo loaded on the loading platform 6 has been discharged from the loading platform 6, the actuators 12A and 12B contract and rotate the loading platform 6 in the returning direction around the rotating shaft 52 as the rotation center, returning it to a horizontal posture. Then, the actuators 12A and 12B are further contracted to slide the arms 13A and 13B downward, returning the loading platform 6 to its original lowered position, making it possible for cargo to be loaded.

[0070] As a result, when the loading platform 6 is raised, the agricultural products can be dropped at a higher position and from a position closer to the center of the loading platform 6. In addition, since the arm can be slid up and down, the height of the loading platform lifting / lowering device 7 itself can be kept relatively low by sliding it downward.

[0071] (2) In the bed lifting device 7 according to this embodiment, the upper end support parts 43 of the actuators 12A, 12B are supported between the center of gravity of the bed 6 and the pivot shaft part 52. This configuration makes it possible to prevent the bed 6 from pivoting about the pivot shaft part 52 before it rises when the actuators 12A, 12B are extended with the bed 6 in the lowered position.

[0072] (3) The platform lifting device 7 according to this embodiment has lifting guides 15A, 15B that support the platform 6, which rises and falls due to the extension and contraction of the actuators 12A, 12B, in a constant posture and guide it between the lowered position and the raised position. With this configuration, when the platform 6 rises and falls, the platform 6 rises and falls while maintaining its horizontal posture via the sliding body 6b. As a result, the platform 6 rises and falls in a stable posture without rocking.

[0073] (4) The loading platform lifting device 7 of this embodiment can determine an upper limit for the upward sliding movement of the arms 13A, 13B by inserting the positioning pin 54 into an arbitrarily selected positioning hole 51a from a plurality of positioning holes 51a provided in the arms 13A, 13B.

[0074] As a result, the height of the loading platform 6 can be adjusted according to the height of the tailgate, the width of the loading platform, the height of the loading platform, etc. of the transport vehicle carrying the load to be discharged from the loading platform 6. The effect is that all the load in the loading platform 6 can be reliably discharged onto the loading platform of the transport vehicle according to the size of the transport vehicle, such as a 2-ton truck or a 4-ton truck.

[0075] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various design modifications can be made without departing from the spirit of the present invention as described in the claims. [Explanation of symbols]

[0076] 1 harvester, 2 vehicle body, 3 travelling device, 4 driving device, 5 harvesting device, 6 loading platform, 6a box body, 6b sliding body, 7 loading platform lifting device, 11A, 11B support frame, 12A, 12B actuator, 13A, 13B arm, 14A, 14B guide roller, 15A, 15B lifting guide, 27, 28 connecting member, 51a upper limit positioning hole, 43 upper end support part, 51 main body, 52 rotating shaft part, 54 positioning pin, 61 upper guide roller, 62 lower guide roller

Claims

[Claim 1] The loading platform and Support frames arranged in opposing positions across the loading platform; an arm that protrudes upward from the support frame and is supported so as to be slidable up and down; a pivot shaft portion provided at a tip of the arm and supporting the loading platform rotatably in a direction in which the loading platform is tilted toward a rear portion of the loading platform with the tip of the arm as a pivot center; an actuator that is disposed at a position further forward of the loading platform than the arm, has a lower end supported by the support frame and an upper end supported by the loading platform, and extends and contracts to raise and lower and rotate the loading platform; the actuator extends to raise the platform, and the arm slides to place the platform at an upper limit raised position, and the actuator further extends to rotate the platform around the pivot shaft at the raised position, and places the platform in a tilted position at the rear of the platform; The arm is provided with a plurality of upper limit positioning holes at predetermined intervals in the sliding direction, the support frame is provided with an elongated hole through which the upper limit positioning holes are exposed along a sliding direction of the arm, A platform lifting device, characterized in that a positioning pin is inserted into any one of the plurality of upper limit positioning holes through the elongated hole.

Images