Loading platform lifting device

Abstract

To improve detection sensitivity of a posture of a caster stopper and secure a distance between the caster stopper and a proximity sensor, and protect the proximity sensor.SOLUTION: A load receiving platform lifting device for assisting loading / unloading of a cargo relative to a loading platform of a vehicle includes: a load receiving platform which is elevated / lowered between a height of a floor surface of the loading platform and a grounding height; a caster stopper which is configured to change its posture between an erected posture projecting from a load receiving surface of the load receiving platform, and a fallen posture constituting a part of the load receiving surface; a proximity sensor which is provided on one of the caster stopper and the load receiving platform, and detects a posture of the caster stopper; and a target which is a component to be detected by the proximity sensor and is provided on the other of the caster stopper and the load receiving platform, wherein the target is formed of a material different from the other caster stopper or load receiving platform.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a loading platform lifting device that raises and lowers a loading platform between the height of the floor surface of a vehicle loading platform and the height at which the platform touches the ground, thereby assisting in loading and unloading of luggage onto and from the loading platform of a vehicle. [Background technology]

[0002] The loading platform of a loading platform lifting device may be provided with caster stoppers (wheel stops) that stand up and protrude from the loading surface to allow for easier loading and unloading of carts. In order to detect the position of the caster stoppers, a loading platform lifting device is known that is provided with a proximity sensor that detects caster stoppers in a collapsed position (Patent Document 1, etc.). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5545649 Summary of the Invention [Problem to be solved by the invention]

[0004] Due to their role, caster stoppers may be subject to forceful collisions with carts carrying heavy loads. When a proximity sensor is used to detect the position of a caster stopper, deformation or misalignment of the caster stopper's components due to a cart collision can change the distance between the proximity sensor and the caster stopper. In particular, loading platforms and caster stoppers are sometimes made of aluminum to reduce weight, and in this case, it is difficult to completely avoid deformation caused by everyday cart use due to the properties of the material.

[0005] Therefore, to avoid damage to the proximity sensor due to interference with the cast stopper, it is desirable to ensure a sufficient distance between the proximity sensor and the cast stopper, assuming deformation or misalignment of the cast stopper. However, it has been discovered that the proximity sensor will not detect the cast stopper unless it is quite close. Therefore, if a layout is designed to ensure a reasonable distance between the proximity sensor and the cast stopper in order to reduce the risk of damage to the proximity sensor, there is a possibility that the cast stopper will not be detected even if it is slightly deformed or misaligned.

[0006] An object of the present invention is to provide a loading platform lifting device that can improve the detection sensitivity of the position of the caster stopper, ensure the distance between the caster stopper and the proximity sensor, and thereby protect the proximity sensor. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention provides a loading platform lifting device that assists in loading and unloading of cargo onto a vehicle loading platform, the loading platform lifting and lowering device comprising: a loading platform that lifts and lowers between the height of the floor surface of the loading platform and the height at which it touches the ground; a caster stopper that is configured to be able to change its position between an upright position that protrudes from the loading surface of the loading platform and a laid position that forms part of the loading surface; a proximity sensor that is provided on one of the caster stopper and the loading platform and detects the position of the caster stopper; and a component that is the object of detection by the proximity sensor and is provided on the other of the caster stopper and the loading platform. , for detecting the posture of the caster stopper The load receiving platform lifting device includes a target, and the target is formed of a material different from the other of the caster stopper or the load receiving platform. [Effects of the Invention]

[0008] According to the present invention, the detection sensitivity of the position of the caster stopper is improved, thereby ensuring the distance between the caster stopper and the proximity sensor, and ultimately protecting the proximity sensor. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a side view showing the overall structure of a vehicle equipped with a loading platform lifting device according to an embodiment of the present invention. [Figure 2] 1 is a perspective view of a loading platform lifting device (with the loading platform stored) according to an embodiment of the present invention; FIG. [Figure 3] 1 is a perspective view of a loading platform lifting device (load platform unfolded state) according to an embodiment of the present invention; FIG. [Figure 4] FIG. 1 is a plan view of a loading platform provided in a loading platform lifting device according to an embodiment of the present invention; [Figure 5] Enlarged view of V in Figure 4 [Figure 6] Cross-sectional view taken along line VI-VI in Figure 5 [Figure 7] 1 is a perspective view of a target provided in a loading platform lifting device according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] -vehicle- 1 is a side view showing the overall structure of a vehicle equipped with a platform lifting device according to one embodiment of the present invention. In this specification, the left and right sides of FIG. 1 are defined as the front and rear sides of the platform lifting device 4.

[0012] The vehicle shown in Fig. 1 is configured to include a vehicle frame 1, a driver's cab 2 provided at the front of the vehicle frame 1, a loading platform 3 mounted on the vehicle frame 1, and an underfloor-storable loading platform lifting device 4 provided on the rear underside of the vehicle frame 1. When the loading platform lifting device 4 is not in use, such as when the vehicle is traveling, the loading platform 5 is folded and stored under the vehicle frame 1. When in use, the loading platform lifting device 4 unfolds the loading platform 5 by pulling it out rearward, and raises and lowers the loading platform 5 between the height of the floor of the loading platform 3 and the height at which it touches the ground, thereby assisting in loading and unloading of cargo onto and from the loading platform 3.

[0013] -Load receiving platform lifting device- 2 and 3 are perspective views showing the detailed structure of the receiving platform lifting device 4, with Fig. 2 showing the receiving platform 5 in a stored state and Fig. 3 showing the receiving platform 5 in an unfolded state. Also, Fig. 4 is a plan view of the receiving platform 5, Fig. 5 is an enlarged view of part V in Fig. 4, Fig. 6 is a cross-sectional view taken along line VI-VI in Fig. 5, and Fig. 7 is a perspective view of the target (described later).

[0014] As shown in Figures 2 and 3, the receiving platform lifting device 4 is configured to include the receiving platform 5 on which cargo is loaded, as well as a slide unit 6, a lift unit 7, a power unit 26, an operating device 27, etc. The slide unit 6 is a device that slides the receiving platform 5 back and forth. The lift unit 7 is a device that raises and lowers the receiving platform 5. The power unit 26 is a device that drives the slide unit 6 and the lift unit 7. The operating device 27 is a device that operates the receiving platform lifting device 4. These elements will be explained in order.

[0015] -Slide unit- The slide unit 6 includes left and right guide rails 8, left and right sliders 9, a cross member 10, left and right brackets 11, supports 13 (FIG. 3), guide rollers 12, a slide cylinder 14, and the like.

[0016] The left and right guide rails 8 are attached to the rear lower side of the vehicle frame 1 so as to extend in the front-to-rear direction. The left and right sliders 9 are supported by the left and right guide rails 8, respectively, and can move back and forth along the guide rails 8. A cross member 10 connects the left and right sliders 9. The left and right brackets 11 are provided at the ends of the cross member 10 that protrude outward from the slider 9 on the left and right sides. The support 13 is a cantilever-shaped frame fixed to the slider 9 and protruding rearward. The guide roller 12 is rotatably supported at the tip (rear end) of the support 13 with its rotation axis extended left and right, and supports and guides the load receiving platform 5 when storing and deploying. The slide cylinder 14 is a double-acting cylinder, and both ends are connected to the guide rails 8 and the slider 9 via appropriate support members. The extension and retraction of the slide cylinder 14 moves the left and right sliders 9 back and forth along the guide rails 8. When the slider 9 moves, the cross member 10, bracket 11, support 13, guide roller 12 and cargo receiving platform 5 move back and forth along the guide rail 8 together with the slider 9.

[0017] -Lift unit- The lift unit 7 includes a first arm (tilt arm) 17, a second arm (lift arm) 18, a third arm (compression arm) 19, and a lift cylinder 20, one pair on each side.

[0018] The upper end of the first arm 17 is rotatably connected to the bracket 11. The front end of the second arm 18 is rotatably connected to the first arm 17 and the rear end is rotatably connected to the loading platform 5. The front end of the third arm 19 is rotatably connected to the bracket 11 and the rear end is rotatably connected to the loading platform 5. The lift cylinder 20 is a single-acting cylinder, and its rod side is rotatably connected to the lower end of the first arm 17 and its bottom side is rotatably connected to the second arm 18. The second arm 18 and the third arm 19 form a parallel link that connects the loading platform 5 to the slider 9 so that it can be raised and lowered, and this parallel link is rotated up and down as the lift cylinder 20 is driven to extend and retract, thereby raising and lowering the loading platform 5 while maintaining a horizontal position.

[0019] -Loading platform- The receiving platform 5 is foldable and includes a receiving platform base end 21 supported by the lift unit 7, a receiving platform main body 23 connected to the receiving platform base end 21 via a hinge 22, and a receiving platform tip end 25 connected to the receiving platform main body 23 via a hinge 24. However, in order to avoid cluttering the illustration in Figure 4, the receiving platform base end 21, the receiving platform main body 23, and the receiving platform tip end 25 are not distinguished from each other and are shown as a single receiving platform 5. The hinge 22 is rotatably connected at both ends to the receiving platform base end 21 and the receiving platform main body 23 via pins (not shown), and the rotation mechanism of the receiving platform main body 23 relative to the receiving platform base end 21 is a two-axis folding structure via the hinge 22. Similarly, the hinge 24 is rotatably connected to the receiving platform main body 23 and the receiving platform tip 25 via a pin (not shown), and the rotation mechanism of the receiving platform tip 25 relative to the receiving platform main body 23 is a two-axis folding structure via the hinge 24. The receiving platform tip 25 and the receiving platform main body 23 rotate upward from the unfolded state and fold over the top of the receiving platform main body 23 and the receiving platform base end 21, respectively. This example illustrates a receiving platform 5 that folds in two places, but the receiving platform 5 may also be configured to fold in only one place.

[0020] The receiving platform 5 is made of extruded aluminum and has multiple hollows 5a (FIG. 6) extending in the width direction to reduce weight. Side moldings 28 are provided on the sides of the receiving platform 5. The side moldings 28 are rod-shaped members with a U-shaped cross section, and are attached to the receiving platform 5 so as to cover the left and right end faces of the receiving platform 5 and close the left and right openings of each hollow 5a. The side moldings 28 form a certain level of step with respect to the receiving surface of the receiving platform 5 and also serve as a stopper for vehicles being placed on the receiving platform 5. Although not shown in the drawings, side guards that protrude higher from the receiving surface than the side moldings 28 may be installed inside (inside in the width direction) of the side moldings 28. When a cart or the like gets on or off the receiving platform 5, the cart passes between the left and right side moldings 28 (or the left and right side guards, if side guards are present).

[0021] -Power unit- The power unit 26 includes a hydraulic drive device for driving the slide unit 6 and the lift unit 7, specifically the slide cylinder 14 and the lift cylinder 20, and in this embodiment is provided on the bracket 11 on the right side of the slide unit 6.

[0022] -Operation device- The operating device 27 is a wired controller (for example, a pendant operation type) and is stored in a storage box. Although not shown, the loading platform lifting device 4 is also provided with a wireless operating device (remote control).

[0023] - Caster stopper - Furthermore, the loading platform 5 is provided with caster stoppers 30 that act as wheel stops to allow for easier loading and unloading of carts and the like. The caster stoppers 30 are also made of extruded aluminum, just like the loading platform 5. The caster stoppers 30 are located at the rear of the loading platform 5 and extend in the left-right direction. They are used by standing upright at the rear of a cart loaded on the loading platform 5.

[0024] The caster stopper 30 is configured such that its rear portion is connected to the load receiving platform 5 via a hinge 31, and its front portion can rotate up and down to change its position between an upright position and a lying position. Specifically, in this embodiment, the cavity 5a (in this example, the rearmost cavity 5a) of the load receiving platform 5 (load receiving platform tip portion 25) is open to the load receiving surface over its entire length on the left and right, and the caster stopper 30 is configured to open and close the upper opening of the cavity 5a between the left and right side moldings 28. With this configuration, in the lying position ( FIG. 4 , etc.), the caster stopper 30 closes the upper opening of the cavity 5a of the load receiving platform 5 and forms part of the load receiving surface of the load receiving platform 5, and in the upright position (not shown), it protrudes upward from the load receiving surface of the load receiving platform 5 and functions as a rear wheel stopper.

[0025] The caster stopper 30 is configured to be pushed up in the standing direction by a biasing means (not shown) such as a spring. Therefore, the platform lifting / lowering device 4 is provided with a locking device (not shown) that restrains the caster stopper 30 in the lying position.

[0026] -Posture detection device- The platform lifting device 4 is equipped with a posture detection device 40 that detects the posture of the caster stopper 30, i.e., whether it is in a lying position or an upright position. In this embodiment, the posture detection devices 40 are installed on both the left and right sides of the caster stopper 30, as shown in FIG.

[0027] The attitude detection device 40 includes a proximity sensor 41 (FIG. 6), a bracket 42, and a target 45.

[0028] The proximity sensor 41 is a non-contact sensor for detecting the position of the caster stopper 30, and in this embodiment is attached to the loading platform 5 via a bracket 42 and is disposed inside the hollow portion 5a that is opened and closed by the caster stopper 30. The proximity sensor 41 may be, for example, an inductive proximity sensor, a capacitive proximity sensor, a magnetic proximity sensor, a range finder that uses sound waves or a laser, or a photoelectric sensor. The proximity sensor 41 is connected to a control device (not shown) of the loading platform lifting device 4 via wiring (not shown), and the output signal of the proximity sensor 41 is input to the control device.

[0029] The bracket 42 is a component that holds the proximity sensor 41 and is provided on either the caster stopper 30 or the load receiving platform 5 (the load receiving platform 5 in this embodiment). In this embodiment, the bracket 42 is composed of a plate 43 and an L-shaped bracket 44. The plate 43 is located between the caster stopper 30 and the side molding 28, and is arranged so as to straddle the upper opening of the cavity 5a of the load receiving platform 5, which the caster stopper 30 opens and closes, from front to back. The plate 43 is fixed to the load receiving surface of the load receiving platform 5 with multiple fasteners S1 (screws, bolts, etc.). The L-shaped bracket 44 is fixed to the back surface of the plate 43 (the surface facing away from the load receiving surface) with fasteners S2 (screws, bolts, etc.), and is located in the cavity 5a when the caster stopper 30 is in the laid-down position. The proximity sensor 41 is fixed to this L-shaped bracket 44 with fasteners S3 (screws, bolts, etc.). The proximity sensor 41 is attached to the loading platform 5 by a bracket 42 with its detection surface facing inward in the width direction of the loading platform 5, i.e., toward the caster stopper 30 (more precisely, toward the target 45 when the caster stopper 30 is in the laid-down position). The detection surface of the proximity sensor 41 is the surface that detects the target 45. When the target 45 approaches the detection surface, the target 45 is detected by the proximity sensor 41.

[0030] The target 45 is a component to be detected by the proximity sensor 41. It is attached to the other of the caster stopper 30 and the loading platform 5 (the caster stopper 30 in this embodiment) and is made of a different material from the caster stopper 30 and the loading platform 5. The target 45 is arranged so as to face the detection surface of the proximity sensor 41 when the caster stopper 30 is in a lying position. The target 45 is made of a material that allows the proximity sensor 41 to detect the target 45 from a longer distance than the materials of the caster stopper 30 and the loading platform 5. The detection distance is the distance from the detection surface of the proximity sensor 41 to the target 45, and is the distance at which the proximity sensor 41 can detect the target 45. The material of the target 45 is selected depending on the detection method of the proximity sensor 41, and differs from the material of the caster stopper 30 in terms of, for example, electrical resistivity, dielectric constant, or magnetic force. In this embodiment, the caster stopper 30 and the loading platform 5 are made of aluminum, while the target 45 is made of a material that allows the detection distance to be longer than that of aluminum (for example, steel such as carbon steel or alloy steel).

[0031] Furthermore, in this embodiment, the target 45 is a block- or plate-shaped member attached to the surface of the caster stopper 30 opposite the load-receiving surface with fasteners such as screws or bolts (not shown). However, the target 45 is not necessarily limited to being attached to the caster stopper 30 with fasteners or the like, and may be, for example, a coating such as paint or plating applied to the surface of the caster stopper 30 facing the proximity sensor 41. In this case, when comparing detection distances, it is sufficient that the coated caster stopper 30 is longer than the material of the caster stopper 30 and the load-receiving platform 5. The detection surface of the target 45 (i.e., the surface onto which the electromagnetic waves of the proximity sensor 41 are applied) is roughly aligned with the end face of the caster stopper 30 in the left-right direction.

[0032] With the posture detection device 40 configured as described above, when the caster stopper 30 is in a lying position, the target 45 faces the proximity sensor 41, which detects the target 45 and detects that the caster stopper 30 is in a lying position. Conversely, when the caster stopper 30 is in an upright position, the target 45 is outside the detection range of the proximity sensor 41 and is not detected, so this non-detection state can be used to detect that the caster stopper 30 is in an upright position.

[0033] Furthermore, the receiving platform lifting device 4 is provided with a position adjustment mechanism that adjusts the position of the proximity sensor 41, and is configured to be able to adjust the position (distance, etc.) of the proximity sensor 41 relative to the target 45. The position adjustment mechanism can be configured as appropriate, and one example is a configuration in which the through-hole in the L-shaped bracket 44 through which the fastener S2 passes is an elongated hole with its major axis extending in the traveling direction of the electromagnetic waves transmitted and received by the proximity sensor 41. In this case, for example, the position (distance, etc.) of the proximity sensor 41 relative to the target 45 can be adjusted by loosening the fastener S2 and shifting the L-shaped bracket 44 left or right relative to the plate 43.

[0034] -effect- Through careful study, the inventors of the present application have found that the detection distance of an object by proximity sensor 41 varies depending on the material of the object. For example, when attempting to directly detect caster stopper 30 made of aluminum with proximity sensor 41, caster stopper 30 was not detected unless it approached within an extremely short distance (approximately 2 mm in experiments) from proximity sensor 41.

[0035] Based on this knowledge, in this embodiment, the proximity sensor 41 is configured to detect the target 45, which is made of a different material than the caster stopper 30 and is therefore easier to detect than the caster stopper 30. This improves the detection sensitivity of the posture of the caster stopper 30 compared to when the proximity sensor 41 directly detects the caster stopper 30, and the posture of the caster stopper 30 can be stably detected even if there is a sufficient distance between the target 45 and the proximity sensor 41. Therefore, even if the caster stopper 30 or the target 45 approaches the proximity sensor 41 due to deformation or misalignment, the risk of the caster stopper 30 or the target 45 interfering with the proximity sensor 41 is reduced, and the proximity sensor 41 can be protected.

[0036] Since the position of the proximity sensor 41 can be detected stably, this detection information can be used for various control and notification operations of the platform lifting / lowering device 4 and the vehicle.

[0037] Furthermore, since a position adjustment mechanism for adjusting the position of the proximity sensor 41 is provided, the distance between the proximity sensor 41 and the target 45 can be flexibly restored even if the distance between them changes due to deformation of the caster stopper 30 or the like. This allows the loading platform lifting device 4 to be operated continuously, for example, without having to correct deformation of the caster stopper 30 or replace the caster stopper 30 or the attitude detection device 40.

[0038] -Variations- In the above embodiment, an example has been described in which the proximity sensor 41 is installed in an orientation in which the transmitted and received electromagnetic waves travel left and right, but the installation orientation of the proximity sensor 41 is not limited to this. For example, the proximity sensor 41 may be configured to detect the underside of the target 45 (the surface facing away from the receiving surface). In this case, the position of the orientation detection device 40 does not need to be on the left or right of the caster stopper 30.

[0039] In addition, although the above description has been given with reference to an example in which the posture detection devices 40 are installed on both the left and right sides of the caster stopper 30, it is not necessary to provide multiple posture detection devices 40 as described above; at least one posture detection device 40 is sufficient. For example, in the above embodiment, it is possible to omit either the left or right posture detection device 40.

[0040] Furthermore, although an example of a configuration in which the target 45 approaches the proximity sensor 41 when the caster stopper 30 is in a lying position has been described, the configuration in which the target 45 approaches the proximity sensor 41 when the caster stopper 30 is in an upright position may also be used.

[0041] In addition, although the configuration in which the proximity sensor 41 is provided on the cargo receiving platform 5 and the target 45 is provided on the caster stopper 30 has been described as an example, it is also possible to provide the target 45 on the cargo receiving platform 5 and the proximity sensor 41 on the caster stopper 30.

[0042] Also, although the example has been described in which the loading platform 5 and the caster stopper 30 are both made of aluminum, they may be made of different materials. In this case, if the target 45 is provided on the caster stopper 30, it is sufficient that the materials of the caster stopper 30 and the target 45 are different as described above, and it is also acceptable that the materials of the loading platform 5 and the target 45 are the same. Conversely, if the target 45 is provided on the loading platform 5, it is sufficient that the materials of the loading platform 5 and the target 45 are different, and it is also acceptable that the materials of the caster stopper 30 and the target 45 are the same.

[0043] Furthermore, while the present invention has been described as being applied to a retractable platform lifting device that stores the platform under the rear of the vehicle frame, the present invention can also be applied to other types of platform lifting devices. Some platform lifting devices, for example, have a platform that stands upright along the wall of the vehicle's platform when stored, but that extends horizontally and rises and falls vertically when in use. Furthermore, even if the platform is raised and lowered via a parallel link, like the platform lifting device of this embodiment, some platforms do not store the platform in the lower part of the vehicle frame but instead stand upright along the wall of the vehicle's platform in a stowed position. Because the present invention relates to a platform caster stopper, it can be applied to any platform lifting device that has a platform caster stopper, regardless of the platform's lifting or storage method. When the present invention is applied to these platform lifting devices, the same effects as those of the above embodiment can be achieved. [Explanation of symbols]

[0044] 3...loading platform, 4...loading platform lifting device, 5...loading platform, 30...caster stopper, 41...proximity sensor, 42...bracket, 45...target

Claims

1. A loading platform lifting device that assists loading and unloading of luggage onto and from a vehicle loading platform, a loading platform that moves up and down between the height of the floor surface of the loading platform and the height at which the loading platform is in contact with the ground; a caster stopper configured to be able to change its position between an upright position protruding from the load receiving surface of the load receiving platform and a laid-down position constituting a part of the load receiving surface; a proximity sensor provided on one of the caster stopper and the loading platform, the proximity sensor detecting the position of the caster stopper; a target for detecting the attitude of the caster stopper, the target being a part to be detected by the proximity sensor and provided on the other of the caster stopper and the loading platform; The target is formed of a material different from that of the other of the caster stopper or the load receiving platform. A loading platform lifting device characterized by the above.

2. The loading platform lifting device according to claim 1, A loading platform lifting device characterized in that the material of the target is different from the materials of the caster stopper and the loading platform in terms of either electrical resistivity, dielectric constant, or magnetic force, depending on the detection method of the proximity sensor.

3. The loading platform lifting device according to claim 1 or 2, A loading platform lifting device, characterized in that the caster stopper and the loading platform are made of aluminum, and the target is made of steel.

4. In the loading platform lifting device according to any one of claims 1 to 3, The loading platform lifting device is characterized in that the target is a member attached to the caster stopper.

5. In the loading platform lifting device according to any one of claims 1 to 3, The loading platform lifting device, wherein the target is a coating applied to the caster stopper.

6. The loading platform lifting device according to any one of claims 1 to 5, A loading platform lifting device comprising a position adjustment mechanism for adjusting the position of the proximity sensor.

Images