Loading platform lifting device

Abstract

The objective is to provide a loading platform lifting device that can prevent the loading platform from rising from its lowered position while the flap remains folded down. [Solution] The loading platform lifting device 1 comprises a loading platform 19 having a loading surface 19a on which loads are placed, a lower arm 17 with one end connected to the loading platform 19, a lifting mechanism 18 that raises and lowers the loading platform 19 between an elevated position and a lowered position, a flap 40 provided at the base of the loading platform 19 so as to be able to pivot between an upright position where it stands upright relative to the loading surface 19a and a lowered position where it lies down relative to the loading surface 19a, a biasing member 50 that biases the flap 40 toward the upright position, and a holding member 60 provided on the lower arm 17 that contacts the flap 40 when the loading platform 19 is in the lowered position and forcibly holds the flap 40 in the upright position.

Description

Technical Field

[0001] The present disclosure relates to a loading platform lifting device.

Background Art

[0002] As a loading platform lifting device mounted on a truck or the like and used for loading and unloading goods, for example, there is one described in Patent Document 1. The loading platform lifting device of Patent Document 1 includes a loading platform disposed behind a loading box of a truck, a lifting mechanism for lifting and lowering the loading platform between a raised position and a lowered position, a flap provided at a base (front part) of the loading platform so as to be able to rise and fall, and a spring for biasing the flap in a standing-up direction.

[0003] When the loading platform is ascending and in the lowered position, the flap is maintained in a standing-up posture by the spring force, so that it is possible to prevent the goods on the loading platform from falling. When the loading platform is in the raised position, the flap abuts against the loading box side, and thus becomes a lying-down posture against the spring force, and functions as a transfer plate that fills the space between the upper surface of the loading platform and the floor surface of the loading box.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the above loading platform lifting device, when the loading platform is in the lowered position, for example, when moving a wheeled load such as a cart from the ground onto the loading platform, the load (such as wheels) strongly presses the standing-up flap, so that the flap may become a lying-down posture against the spring force. In this case, since the loading platform rises with the flap remaining lying down, there is a risk that the flap contacts a member on the loading box side during the ascent of the loading platform, and it may become impossible to raise the loading platform.

[0006] This disclosure has been made in view of these circumstances and aims to provide a loading platform lifting device that can prevent the loading platform from rising from its lowered position while the flap remains folded down. [Means for solving the problem]

[0007] (1) The loading platform lifting device of the present disclosure is a loading platform lifting device for loading and unloading cargo onto a loading platform mounted on a vehicle body, comprising: a loading platform having a loading surface on which the cargo is placed; a lifting mechanism having an arm with one end connected to the loading platform, for raising and lowering the loading platform between a raised position and a lowered position; a flap provided at the base of the loading platform so as to be able to pivot up and down between an upright position in which it stands upright relative to the loading surface and a lowered position in which it lies down relative to the loading surface; a biasing member for biasing the flap toward the upright position; and a holding member provided on one of the arm and the flap, which, when the loading platform is in the lowered position, abuts against the other of the arm and the flap to forcibly hold the flap in the upright position.

[0008] According to the loading platform lifting device of this disclosure, when the loading platform is in the lowered position, the flap is forcibly held in the upright position by the holding member. As a result, for example, when moving a wheeled load onto the loading surface of the loading platform in the lowered position, even if the load strongly presses against the flap, the flap will be held in the upright position without collapsing. Therefore, since it is possible to suppress the flap from collapsing when the loading platform is in the lowered position, it is possible to suppress the loading platform from rising from the lowered position while the flap remains in the collapsed position.

[0009] (2) In the loading platform lifting device of (1) above, it is preferable that the holding member has an adjustment part for adjusting the upright angle of the flap with respect to the loading surface when the holding member holds the flap in the upright position. In this case, even if the relative positions of the arm and flap differ for each loading platform lifting device, the flap's upright angle can be adjusted by the adjustment part of the holding member according to those relative positions.

[0010] (3) In the loading platform lifting device of (2) above, the holding member further comprises a fixing portion fixed to one of the above and a contact portion attached to the fixing portion via the adjustment portion and in contact with the other, wherein the adjustment portion preferably comprises an elongated hole formed on one side of the fixing portion and the contact portion and a pin fixed to the other side of the fixing portion and the contact portion, inserted into the elongated hole and movable relative to the elongated hole. In this case, the mounting position of the contact portion relative to the fixed portion can be changed by moving the pin along the elongated hole in the adjustment section. By changing the mounting position, the contact position of the contact portion on the other side shifts, and the upright angle of the flap changes. Therefore, the upright angle of the flap can be easily adjusted using the adjustment section.

[0011] (4) In any of the loading platform lifting devices described in (1) to (3) above, it is preferable that the holding member is provided on the back side of the flap and contacts the arm when the loading platform is in the lowered position to forcibly hold the flap in the upright position. In this case, the flap can be forcibly held in the upright position by the holding member without modifying the lifting mechanism.

[0012] (5) In the loading platform lifting device of (3) above, the holding member is provided on the back side of the flap and, when the loading platform is in the lowered position, contacts the arm to forcibly hold the flap in the upright position, and preferably the longitudinal direction of the elongated hole is parallel to the direction from the rotating base end to the rotating tip of the flap. In this case, the flap can be forcibly held in the upright position by the holding member without modifying the lifting mechanism. Furthermore, the holding member can be compactly configured in a direction perpendicular to the direction from the base end to the tip end of the flap's rotation.

[0013] (6) In any of the loading platform lifting devices described in (1) to (5) above, the loading platform has a base loading portion provided on the lifting mechanism and a front loading portion that can be folded and unfolded relative to the base loading portion, and the front loading portion can be stored below the vehicle body in a folded state when folded relative to the base loading portion, and the flap is provided on the base loading portion so as to be able to rise and fall, and when the loading platform is stored below the vehicle body in the folded state, the front loading portion contacts the flap and is held in the folded position. In such a loading platform lifting device, for example, if the loading platform is stored in the lower part of the vehicle body in a folded state for a long period of time, the flap may become fixed in the folded position. However, even in such cases, when the loading platform is moved to the lowered position for use, the flap is forcibly held in the upright position by the holding member. Therefore, it is possible to prevent the loading platform from rising from the lowered position while the flap remains fixed in the folded position. [Effects of the Invention]

[0014] According to the load-receiving platform lifting device of the present invention, it is possible to prevent the load-receiving platform from rising from its lowered position while the flap remains folded down. [Brief explanation of the drawing]

[0015] [Figure 1] This is a side view showing a loading platform lifting device according to an embodiment of the present disclosure mounted on a cargo truck. [Figure 2] This is a plan view of the loading platform lifting device in the state shown in Figure 1. [Figure 3] This is a side view showing the operating status of the loading platform lifting device. [Figure 4] This is a schematic side view showing the slide cylinder of the loading platform lifting device in its fully retracted state. [Figure 5] This is a schematic side view showing the slide cylinder of the loading platform lifting device in its fully extended state. [Figure 6] This is an enlarged side view showing the area around the base of the loading platform in its raised position. [Figure 7] It is an enlarged side view showing the periphery of the base of the loading platform during lifting and lowering. [Figure 8] It is an enlarged side view showing the periphery of the base of the loading platform in the stored state. [Figure 9] It is an enlarged side view showing the periphery of the base of the loading platform in the lowered position. [Figure 10] It is an enlarged side view of the holding member when the flap is in the lying position. [Figure 11] It is a view taken in the direction of arrow I in FIG. 10. [Figure 12] It is a cross-sectional view taken along the line II-II in FIG. 10.

Mode for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. [Overall Configuration] FIG. 1 is a side view showing a state in which a loading platform lifting device 1 according to an embodiment of the present disclosure is mounted on a freight vehicle V. FIG. 2 is a plan view of the loading platform lifting device 1 in the state of FIG. 1. Directions such as "up", "down", "front", "rear", "right", and "left" mean the directions shown in FIGS. 1 and 2. In FIG. 1, the freight vehicle V includes a vehicle body 2 and a loading platform B mounted on the vehicle body 2.

[0017] The vehicle body 2 has a chassis frame 2a and a sub-frame 2b provided on the chassis frame 2a. The sub-frame 2b is disposed on the lower surface of the loading platform B and reinforces the loading platform B. The loading platform lifting device 1 is a device for loading and unloading goods with respect to the loading platform B. The loading platform lifting device 1 of the present embodiment is a so-called underfloor storage type and is stored below the rear part of the chassis frame 2a in a predetermined storage posture. The freight vehicle V can travel in the state shown in FIG. 1.

[0018] Figure 3 is a side view showing the loading platform lifting device 1 in use. As shown in Figure 3, the loading platform lifting device 1 is used when the loading platform 19 etc. is slid from the sliding front end position (forward position) shown in Figure 1 to the sliding rear end position (rear position) behind the loading platform B. In Figures 1 and 3, the loading platform lifting device 1 comprises a fixed-side support member 3, a movable-side support member 13, a lifting mechanism 18, a loading platform 19, and a forward / rear drive device 22.

[0019] The fixed-side support members 3 are arranged in pairs in the vehicle width direction (left-right direction) at the lower rear of the vehicle body 2 and are provided on the vehicle body 2. Each fixed-side support member 3 has a slide rail 4, a plurality (3 in this embodiment) of mounting brackets 5, and a fixed connecting member 6. The slide rail 4 is arranged extending horizontally in the front-rear direction at the lower part of the vehicle body 2. The fixed connecting member 6 is made of, for example, a square pipe and connects the front ends of the slide rails 4 on the left and right pair of fixed-side support members 3 (see Figure 2).

[0020] The multiple mounting brackets 5 are components for attaching the slide rail 4 to the vehicle body 2. The multiple mounting brackets 5 are arranged at intervals in the front-rear direction along the outer surface of the vehicle body 2 and are fixed to the outer surface of the vehicle body 2. The slide rail 4 is fastened to each mounting bracket 5 by two bolts 7 or the like.

[0021] In Figures 1 and 2, the movable support member 13 is provided so as to be slidable in the front-rear direction relative to the fixed support member 3. The movable support member 13 includes a pair of left and right support plates 8, a cross member 9, a pair of left and right first support brackets 10, a pair of left and right second support brackets 11, and a movable connecting member 12.

[0022] The support plate 8 is provided so as to be slidable in the front-rear direction relative to the slide rail 4. The cross member 9 is made of a square pipe that extends horizontally in the vehicle width direction. The cross member 9 passes through the pair of support plates 8 on the left and right sides and is fixed to these support plates 8 by welding or the like. The ends of the cross member 9 in the vehicle width direction are constructed of three layers of square pipes for reinforcement, but the middle section of the cross member 9 in the vehicle width direction is made of only one square pipe.

[0023] The left and right pair of first support brackets 10 are fixed to the cross member 9 at both ends, outside in the vehicle width direction, beyond the support plates 8. The left and right pair of second support brackets 11 are fixed to the cross member 9 at both ends, outside in the vehicle width direction, beyond the first support brackets 10. The movable connecting member 12 is made of channel material and connects the lower parts of the left and right pair of support plates 8.

[0024] In Figures 1 to 3, the lifting mechanism 18 is a mechanism that raises and lowers the loading platform 19 between a raised position and a lowered position, which will be described later. The lifting mechanism 18 includes an auxiliary link 14, an upper arm 15, a lift cylinder 16, and a lower arm (arm) 17. The auxiliary link 14, upper arm 15, lift cylinder 16, and lower arm 17 are each provided in pairs on the left and right sides.

[0025] The auxiliary link 14 is pivotably mounted to the first support bracket 10. The front ends of the upper arm 15 and the lift cylinder 16 are rotatably mounted to the first support bracket 10. The lift cylinder 16 is a hydraulic cylinder for raising and lowering (moving) the loading platform 19. The lift cylinder 16 in this embodiment is, for example, a single-acting hydraulic cylinder.

[0026] The lift cylinder 16 comprises a cylindrical cylinder body 16a, a piston head (not shown) provided within the cylinder body 16a to reciprocate in the front-rear direction, and a piston rod 16c whose base end is connected to the piston head. The tip of the piston rod 16c is connected to a predetermined position on the upper arm 15. The lift cylinder 16 applies torque to the upper arm 15 through its extension and retraction operation.

[0027] The front end of the lower arm 17 is rotatably attached to the second support bracket 11. The lower arm 17 is positioned further outward in the vehicle width direction than the upper arm 15. The upper arm 15 and the lower arm 17 form a parallel link in which the rectangle connecting their fulcrum and point of application is a parallelogram. The front end (rear end) of this parallel link moves up and down as the lift cylinder 16 extends and retracts.

[0028] The loading platform 19 has a base loading section 191, a front loading section 192, and a connecting section 193. Note that the loading platform 19 is not shown in Figure 2. The base loading section 191 is connected to the rear end (one end) of the upper arm 15 and the lower arm 17, and the upper surface of the base loading section 191 is kept horizontal by a parallel link.

[0029] The front load-receiving section 192 is connected to the base load-receiving section 191 via a connecting section 193. The connecting section 193 connects the base load-receiving section 191 and the front load-receiving section 192. The connecting section 193 has a hinge 193a, one end of which is rotatably connected to the front end of the base load-receiving section 191, and the other end of which is rotatably connected to the base end of the front load-receiving section 192. As a result, the front load-receiving section 192 can be folded and unfolded relative to the base load-receiving section 191.

[0030] When the loading platform lifting device 1 is in use, the front loading portion 192 is extended relative to the base loading portion 191, thereby forming a loading surface 19a on the loading platform 19, consisting of the upper surface of the base loading portion 191 and the upper surface of the front loading portion 192. The cargo to be loaded and unloaded onto the loading platform B is placed on this loading surface 19a.

[0031] With the loading surface 19a formed on the loading platform 19, the lift cylinder 16 can be extended and retracted to raise and lower the loading platform 19 between a raised position (upper position in Figure 3) and a lowered position (lower position in Figure 3). The raised position is when the loading surface 19a is at approximately the same height as the floor surface b1 of the cargo bed B. The lowered position is when the loading platform 19 is in contact with the ground. By raising and lowering the loading platform 19 at the rear of the cargo bed B, cargo can be loaded and unloaded onto the cargo bed B of the cargo truck V.

[0032] When the loading platform lifting device 1 is stored, the loading platform 19 is lowered to the lowered position, and the front loading section 192 is folded over the base loading section 191. During this folding process, the tip of the front loading section 192 is propped against the guide roller 21. The guide roller 21 is rotatably mounted on roller mounting plates 20 that protrude rearward from each of the left and right support plates 8.

[0033] The front-rear drive unit 22 is a device that slides (moves back and forth) the movable support member 13, the lifting mechanism 18, and the load receiving platform 19 between a forward position and a rear position relative to the fixed support member 3. The front-rear drive unit 22 has a pair of left and right slide cylinders 23, a pair of front and rear joints 27, a first mounting plate 28, a mounting base 29, and a second mounting plate 30. Figure 2 shows each slide cylinder 23 in its most retracted state.

[0034] Figure 4 is a schematic side view showing the slide cylinder 23 in its most retracted state. Figure 5 is a schematic side view showing the slide cylinder 23 in its most extended state. In Figures 2, 4, and 5, the left and right pair of slide cylinders 23 are positioned in the middle of the fixed-side support member 3 in the vehicle width direction. Each slide cylinder 23 is a hydraulic cylinder for sliding (moving) the load receiving platform 19 in the front-rear direction. In this embodiment, each slide cylinder 23 is, for example, a double-acting hydraulic cylinder.

[0035] Each slide cylinder 23 comprises a cylindrical cylinder body 24, a piston head (not shown) provided within the cylinder body 24 to reciprocate axially, and a piston rod 26 whose base end is connected to the piston head. The cylinder body 24 has an extension port 24a and a contraction port 24b inside which hydraulic fluid is supplied and discharged (see Figure 6). The cylinder bodies 24 of a pair of left and right slide cylinders 23 are integrally connected by a pair of front and rear joints 27, with the front and rear facing opposite directions. A boss portion 26a is integrally formed at the tip of the piston rod 26 of each slide cylinder 23.

[0036] In the right-hand slide cylinder 23 of Figure 2, the boss portion 26a of the piston rod 26 is attached to a pair of left and right first mounting plates 28 by a pin 31. Each first mounting plate 28 is fixed to the middle portion of the fixed connecting member 6 in the vehicle width direction. In the left-hand slide cylinder 23 of Figure 2, the boss portion 26a of the piston rod 26 is attached to a pair of left and right second mounting plates 30 by a pin 32. Each second mounting plate 30 is fixed to a mounting base 29 located below the slide cylinder 23.

[0037] The mounting base 29 has an upper mounting base portion 29a and a lower mounting base portion 29b fixed to the lower side of the upper mounting base portion 29a. A pair of left and right second mounting plates 30 are fixed to the upper surface of the upper mounting base portion 29a. The lower mounting base portion 29b is formed to be shorter in the front-rear direction than the upper mounting base portion 29a. The lower mounting base portion 29b is fixed to the lower side of the upper mounting base portion 29a by a plurality of bolts 33, etc. The rear end of the lower mounting base portion 29b is fixed to the middle part of the movable connecting member 12 in the vehicle width direction. The front end of the lower mounting base portion 29b is fixed to the middle part of the cross member 9 in the vehicle width direction.

[0038] With the above configuration, when using the loading platform 19 stored in the state shown in Figure 1, the slide cylinder 23 is extended. The extension of the slide cylinder 23 causes the loading platform 19, together with the movable support member 13 and the lifting mechanism 18, to slide to the rear position and be pulled out to the rear of the vehicle body 2. In this state, when the lift cylinder 16 is retracted, the upper arm 15 and lower arm 17 rotate downward as shown by the solid lines in Figure 3, and the base loading portion 191 of the loading platform 19 touches the ground. At this time, the base loading portion 191 is horizontal, and the tip of the front loading portion 192 rests on the guide roller 21. Therefore, the front loading portion 192 rotates slightly clockwise around the connecting portion 193 relative to the base loading portion 191 as shown in Figure 3.

[0039] Next, the operator manually rotates the front load-receiving section 192 clockwise in Figure 3, causing it to fold horizontally behind the base load-receiving section 191. This causes the load-receiving platform 19 to be horizontally deployed in its lowered position. In this state, when the lift cylinder 16 is extended, the load-receiving platform 19 rises from the lowered position to the raised position in Figure 3 while maintaining its horizontal position. When the lift cylinder 16 is retracted from this raised position, the load-receiving platform 19 can be lowered back to its original lowered position.

[0040] Although not shown in Figure 3, when the lower arm 17 lands and the lift cylinder 16 is further retracted, the auxiliary link 14 swings, causing the loading platform 19 to tilt so that the loading surface 19a is inclined downwards towards the rear. This allows for easy loading and unloading of wheeled cargo, such as carts, onto the loading surface 19a by moving them from the rear to the front of the loading platform 19.

[0041] When storing the loading platform 19, the lower arm 17 is on the ground and the loading platform 19 is horizontal. The front loading section 192 is then rotated counterclockwise relative to the base loading section 191 in the direction shown in Figure 3 and placed against the guide roller 21. In this state, when the lift cylinder 16 is extended, the rear ends of the upper arm 15 and the lower arm 17 rise, causing the front loading section 192 to fold over the base loading section 191 due to its own weight. As a result, the loading platform 19 is folded.

[0042] When the loading platform 19 is folded, the extension operation of the lift cylinder 16 is stopped, and the slide cylinder 23 is retracted. As the slide cylinder 23 retracts, the loading platform 19 slides forward together with the movable side support member 13 and the lifting mechanism 18. As a result, the loading platform 19 is retracted into the lower rear of the vehicle body 2, resulting in the stored state shown in Figure 1.

[0043] [flap] Figure 6 is an enlarged side view showing the area around the base of the loading platform 19 in the raised position (see Figure 3). Figure 7 is an enlarged side view showing the area around the base of the loading platform 19 during the raising and lowering process. In Figures 6 and 7, the loading platform lifting device 1 includes a flap 40 that is pivotably mounted at the base of the loading platform 19.

[0044] The flap 40 in this embodiment is provided at the base of the base load receiving section 191 so as to be able to rise and fall. Although not shown in the figures, the width dimension of the flap 40 in the left-right direction is approximately the same as the width dimension of the base load receiving section 191 in the left-right direction. The flap 40 is able to rise and fall between an upright position (the position shown in Figure 7) in which it stands upright relative to the load receiving surface 19a of the load receiving platform 19, and a fallen position (the position shown in Figure 6) in which it lies down relative to the load receiving surface 19a.

[0045] The flap 40 has a shaft portion 41, a rotating portion 42, and a flap portion 43. The shaft portion 41 is rotatably mounted on the back (lower) side of the base of the base load-receiving portion 191, around an axis X extending in the left-right direction. The rotating portion 42 extends from the shaft portion 41 forward of the base load-receiving portion 191. The flap portion 43 has a first flap portion 44 and a second flap portion 45.

[0046] The first flap section 44 is fixed to the middle of the rotating section 42 in the front-rear direction and is positioned adjacent to the front of the base load-receiving section 191 in the state shown in Figure 6. The second flap section 45 is fixed to the front end of the rotating section 42 and is positioned adjacent to the front of the first flap section 44. As a result, the shaft section 41 rotates around axis X and the rotating section 42 rotates in the vertical direction, causing the flap 40 to undulate and rotate about axis X.

[0047] The flap portion 43 has a connecting surface 43a formed by the upper surface of the first flap portion 44 and the upper surface of the second flap portion 45. Note that the flap 40 is not limited to the configuration of this embodiment. For example, the flap portion 43 may be made up of a single member instead of being divided into the first flap portion 44 and the second flap portion 45.

[0048] The load-receiving platform lifting device 1 further includes a biasing member 50 that biases the flap 40 toward the upright position at all times. The biasing member 50 is made of, for example, a torsion spring and is attached to the shaft portion 41 of the flap 40. The biasing member 50 biases the rotating portion 42 of the flap 40 toward the base load-receiving portion 191 so as to always rotate it upward. Note that the biasing member 50 is not limited to the configuration of this embodiment. For example, the biasing member 50 may be made of a counterweight extending from the shaft portion 41 of the flap 40 toward the opposite side of the rotating portion 42. In that case, if the weight of the counterweight is greater than the total weight of the rotating portion 42, the flap portion 43, and the holding member 60 (described later), the weight of the counterweight can bias the flap 40 toward the upright position at all times.

[0049] When the loading platform 19 is being raised or lowered, the flap 40 is biased by the biasing member 50 to the upright position. As a result, even if the load placed on the loading surface 19a of the loading platform 19 moves forward due to vibration or the like while the loading platform 19 is being raised or lowered, the load will come into contact with the flap 40, preventing the load from falling in front of the loading platform 19. Furthermore, when the loading platform 19 is being raised or lowered, the upright flap 40 passes behind the guide roller 21 (see Figure 2), so it does not interfere with the guide roller 21.

[0050] When the loading platform 19 rises to the raised position, the flap 40 is forcibly rotated to a folded position from the upright position against the biasing force of the biasing member 50. The mechanism for forcibly rotating the flap 40 to the folded position by the rise of the loading platform 19 is well known and is similar to the transmission unit described in, for example, Japanese Patent Application Publication No. 2023-162594, so its explanation will be omitted.

[0051] As shown in Figure 6, when the loading platform 19 is in the raised position, the front end of the flap 40, which is in the lowered position, is positioned on the floor surface b1 of the loading platform B, and the bridging surface 43a of the flap portion 43 is flush with the loading surface 19a of the loading platform 19. Therefore, when the loading platform 19 is in the raised position, the flap 40 functions as a bridging plate that fills the gap between the loading surface 19a of the loading platform 19 and the floor surface b1 of the loading platform B.

[0052] Figure 8 is an enlarged side view showing the area around the base of the loading platform 19 in its stowed state (see Figure 1). As shown in Figure 8, when the loading platform 19 is in its stowed state, the front loading portion 192, which is folded onto the base loading portion 191, contacts the crossing surface 43a of the flap 40 from above. Therefore, when the loading platform 19 is in its stowed state, the flap 40 is held in the folded position against the biasing force of the biasing member 50.

[0053] [Retaining member] Figure 9 is an enlarged side view showing the area around the base of the loading platform 19 in the lowered position (see Figure 3). In Figure 9, the loading platform lifting device 1 includes a holding member 60 that forcibly holds the flap 40 in the upright position when the loading platform 19 is in the lowered position. The holding member 60 in this embodiment is provided on the back side of the flap 40 at positions that roughly correspond to each of the left and right pair of lower arms 17 of the lifting mechanism 18. Each holding member 60 has a fixing part 61, a contact part 62, and an adjustment part 63.

[0054] Figure 10 is an enlarged side view of the retaining member 60 when the flap 40 is in the folded position (see Figure 6). Figure 11 is a view taken along arrow I in Figure 10. In Figures 6, 10, and 11, the fixing portion 61 of the retaining member 60 is made of, for example, an L-shaped plate member and has a horizontal plate portion 61a extending in the left-right direction and a vertical plate portion 61b extending in the up-down direction. A pair of through holes 61c are formed through the horizontal plate portion 61a (see also Figure 12). The horizontal plate portion 61a is fixed to the first flap portion 44 of the flap 40 by bolts 68 that pass through the through holes 61c and the rotating portion 42 of the flap 40.

[0055] The vertical plate portion 61b extends downward from the left end, which is the outer end in the vehicle width direction of the horizontal plate portion 61a, and below the rotating portion 42 of the flap 40. The vertical plate portion 61b is positioned outside in the vehicle width direction of the upper arm 15 of the lifting mechanism 18 (see Figure 9).

[0056] Figure 12 is a cross-sectional view taken along the line II-II in Figure 10. In Figures 10 to 12, the contact portion 62 of the holding member 60 is made of, for example, a plate member extending in the front-rear direction. The contact portion 62 is attached to the lower side of the outer surface (left side) of the vertical plate portion 61b of the fixing portion 61 via the adjustment portion 63.

[0057] As shown in Figure 9, the contact portion 62 is positioned so as to be able to contact the lower arm 17 of the lifting mechanism 18 when the load receiving platform 19 is in the lowered position. When the contact portion 62 contacts the lower arm 17, the rotating portion 42 of the flap 40 is forcibly rotated upward via the adjustment portion 63 and fixing portion 61 of the holding member 60. As a result, the flap 40 is forcibly held in the upright position, and its rotation to the down position from the upright position is restricted.

[0058] As the loading platform 19 rises from its lowered position, the contact portion 62 of the holding member 60 separates from the lower arm 17, as shown in Figure 7, and the contact between the contact portion 62 and the lower arm 17 is released. As a result, the holding member 60 releases the forced holding of the flap 40 in the upright position, but the biasing force of the biasing member 50 is always acting on the flap 40, so the flap 40 is maintained in the upright position.

[0059] In Figures 9, 10, and 12, the adjustment portion 63 of the holding member 60 is used to adjust the upright angle α of the flap 40 relative to the load-receiving surface 19a of the load-receiving platform 19 when the holding member 60 forcibly holds the flap 40 in the upright position. The adjustment portion 63 in this embodiment has an elongated hole 64 formed in the contact portion 62, a pair of front and rear pins 65 fixed to the fixing portion 61, and a pair of nuts (regulating portions) 66.

[0060] The elongated hole 64 is formed to penetrate the contact portion 62 in the left-right direction. The longitudinal direction of the elongated hole 64 is parallel to the direction from the pivot base end to the pivot tip of the flap 40 (the direction of the white arrow A in Figure 9). Each of the pair of pins 65 is fixed to the lower side of the outer surface (left side) of the vertical plate portion 61b of the fixing portion 61, protruding outward (to the left).

[0061] Each pin 65 is formed, for example, in a cylindrical shape. The outer diameter of each pin 65 is smaller than the dimension of the elongated hole 64 of the fixing part 61 in the short direction (up and down direction in Figure 10). Each pin 65 is inserted into the elongated hole 64 and is movable relative to it along the longitudinal direction of the elongated hole 64. In this embodiment, each pin 65 protrudes outward through the elongated hole 64 of the fixing part 61. A male thread 65a is formed on the outer circumference of each pin 65.

[0062] Each of the pair of nuts 66 is tightened onto the male thread 65a of the portion of each pin 65 that protrudes from the elongated hole 64. This allows the contact portion 62 to be attached to the fixing portion 61 (vertical plate portion 61b) via the adjustment portion 63. The tightening of the nuts 66 onto the male thread 65a of the pin 65 restricts the relative movement of the pin 65 with respect to the elongated hole 64. Therefore, the nuts 66 in this embodiment function as restrictors that limit the relative movement of the pin 65 with respect to the elongated hole 64.

[0063] When adjusting the upright angle α of the flap 40, the tightening of each nut 66 of the adjustment part 63 is loosened, allowing the pair of pins 65 to move relative to each other along the longitudinal direction of the elongated hole 64. This allows the mounting position of the contact part 62 with respect to the fixing part 61 to be changed along the longitudinal direction of the elongated hole 64. When the mounting position is changed, the contact position of the contact part 62 on the lower arm 17 shifts, so the upright angle α of the flap 40 changes. Therefore, the upright angle α of the flap 40 can be adjusted by changing the mounting position of the contact part 62 with respect to the fixing part 61.

[0064] [Effects and Effects] According to the loading platform lifting device 1 of this embodiment, when the loading platform 19 is in the lowered position, the flap 40 is forcibly held in the upright position by the holding member 60. As a result, for example, when moving a cart, which is a load, onto the loading surface 19a of the loading platform 19 in the lowered position, even if the wheels of the cart or the like strongly press against the flap 40, the flap 40 will be held in the upright position without collapsing. Therefore, since it is possible to suppress the collapsing of the flap 40 when the loading platform 19 is in the lowered position, it is possible to suppress the loading platform 19 from rising from the lowered position while the flap 40 remains in the collapsed position. As a result, it is possible to suppress the flap 40 from contacting the guide roller 21 on the loading platform B side while the loading platform 19 is rising, so that the upward movement of the loading platform 19 is not hindered.

[0065] The holding member 60 has an adjustment section 63 that adjusts the upright angle α of the flap 40 when holding the flap 40 in the upright position. Therefore, even if the relative position between the lower arm 17 and the flap 40 differs for each load-receiving platform lifting device 1, the upright angle α of the flap 40 can be adjusted by the adjustment section 63 of the holding member 60 according to that relative position.

[0066] The adjustment section 63 of the holding member 60 has an elongated hole 64 formed in the fixing section 61 and a pin 65 fixed to the contact section 62 and inserted into the elongated hole 64. Therefore, by moving the pin 65 relative to the elongated hole 64 in the adjustment section 63, the mounting position of the contact section 62 relative to the fixing section 61 can be changed. By changing the mounting position, the contact position of the contact section 62 on the lower arm 17 is shifted, so the upright angle α of the flap 40 changes. Therefore, the upright angle α of the flap 40 can be easily adjusted by the adjustment section 63.

[0067] The retaining member 60 is provided on the underside of the flap 40 and is positioned to contact the lower arm 17 of the lifting mechanism 18. Therefore, the flap 40 can be forcibly held in the upright position by the retaining member 60 without modifying the lifting mechanism 18.

[0068] The longitudinal direction of the elongated hole 64 in the adjustment portion 63 of the retaining member 60 is parallel to the direction from the base end to the tip of the rotation of the flap 40. This allows the retaining member 60 to be compactly constructed in a direction perpendicular to the direction from the base end to the tip of the rotation of the flap 40.

[0069] When the loading platform 19 is folded and stored beneath the vehicle body 2, the front loading portion 192 of the loading platform 19 contacts the flap 40, holding the flap 40 in the folded position. If this state persists for a long time, the flap 40 may become stuck in the folded position. In that case, when moving the loading platform 19 from the stored position to the lowered position for use, even if the front loading portion 192 separates from the flap 40, the flap 40 will remain folded. In this state, if the loading platform 19 is raised from the lowered position, the flap 40 may come into contact with the guide roller 21, potentially preventing the loading platform 19 from being raised.

[0070] However, in this embodiment, even if the flap 40 is fixed in the folded position when the loading platform 19 is stored, when the loading platform 19 is pulled out to the rear of the vehicle body 2 and lowered in order to use it, the flap 40 is rotated upright from the folded position by the holding member 60 and is forcibly held in the upright position. Therefore, in the underfloor storage type loading platform lifting device 1, it is possible to effectively prevent the loading platform 19 from rising from the lowered position while the flap 40 remains fixed in the folded position.

[0071] [others] The loading platform lifting device 1 in the above embodiment is of the underfloor storage type, but other types of loading platform lifting devices such as the upright storage type or the vertical lifting type may also be used. The holding member 60 in the above embodiment is provided on the flap 40 and abuts against the lower arm 17, but it may also abut against the upper arm 15, or it may be provided on the lower arm 17 or the upper arm 15 and abut against the flap 40.

[0072] The longitudinal direction of the elongated hole 64 in the adjustment section 63 of the retaining member 60 is not limited to this embodiment, and may be any direction as long as the upright angle α of the flap 40 can be adjusted. The number of pins 65 in the adjustment section 63 is not limited to this embodiment, and may be one or three or more.

[0073] In the adjustment section 63 of this embodiment, an elongated hole 64 is formed in the contact section 62 and a pin 65 is fixed to the fixing section 61. However, the elongated hole 64 may be formed in the fixing section 61 and the pin 65 may be fixed to the contact section 62. In the adjustment section 63, the restricting section that restricts the relative movement of the pin 65 with respect to the elongated hole 64 is not limited to the nut 66 of this embodiment, but may be, for example, a cotter pin that passes through the pin 65 radially. In that case, it is not necessary to form a male thread 65a on the outer circumference of the pin 65.

[0074] The adjustment section 63 is not limited to the configuration of this embodiment. For example, instead of the elongated hole 64, a plurality of circular holes into which the pin 65 is inserted may be formed in the contact section 62. In that case, the upright angle α of the flap 40 can be adjusted by changing the circular holes into which the pin 65 is inserted. The retaining member 60 may have no adjustment section 63, and the contact section 62 may be fixed to the fixing section 61.

[0075] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the claims, not in the sense described above, and is intended to include all modifications in the sense and scope equivalent to the claims. [Explanation of Symbols]

[0076] 1. Loading platform lifting device 2 car bodies 17 Lower arm (arm) 18 Lifting mechanism 19 Loading platform 19a Load receiving surface 40 Flap 50 biasing member 60 Retaining member 61 Fixed part 62 Contact part 63 Adjustment section 64 long hole 65 pins 191 Base cargo receiving section 192 Front cargo receiving section B Cargo bed α Standing angle

Claims

1. A loading platform lifting device for loading and unloading cargo onto a cargo bed mounted on a vehicle body, A loading platform having a loading surface on which the aforementioned cargo is placed, A lifting mechanism having an arm with one end connected to the load-receiving platform, which raises and lowers the load-receiving platform between a raised position and a lowered position, A flap is provided at the base of the loading platform that can pivot between an upright position, where it stands upright relative to the loading surface, and a lowered position, where it lies down relative to the loading surface. A biasing member that biases the flap toward the upright position, A loading platform lifting device comprising: a holding member provided on one of the arm and the flap, which contacts the other of the arm and the flap when the loading platform is in the lowered position to forcibly hold the flap in the upright position.

2. The lifting device for a loading platform according to claim 1, wherein the holding member has an adjustment part for adjusting the upright angle of the flap with respect to the loading surface when the holding member holds the flap in the upright position.

3. The holding member further comprises a fixing portion fixed to one of the other, and a contact portion attached to the fixing portion via the adjustment portion and in contact with the other, The adjustment unit is, A long hole formed on one side of the fixing portion and the contact portion, The loading platform lifting device according to claim 2, further comprising a pin fixed to the other side of the fixing portion and the contact portion, inserted into the elongated hole and movable relative to the elongated hole.

4. The lifting device for a loading platform according to any one of claims 1 to 3, wherein the holding member is provided on the back side of the flap and, when the loading platform is in the lowered position, contacts the arm to forcibly hold the flap in the upright position.

5. The holding member is provided on the underside of the flap and, when the load receiving platform is in the lowered position, contacts the arm to forcibly hold the flap in the upright position. The loading platform lifting device according to claim 3, wherein the longitudinal direction of the elongated hole is parallel to the direction from the rotating base end to the rotating tip of the flap.

6. The loading platform has a base loading section provided on the lifting mechanism and a front loading section that can be folded and unfolded relative to the base loading section, and the front loading section can be stored below the vehicle body in a folded state with the front loading section folded relative to the base loading section. The loading platform lifting device according to any one of claims 1 to 3, wherein the flap is provided on the base loading platform so as to be able to move up and down, and when the loading platform is stored below the vehicle body in the folded state, the front loading platform comes into contact with the flap, thereby holding it in the folded position.

Images