Loading platform lifting device

Abstract

To avoid lighting of a lamp during travel.SOLUTION: In a receiving table lifting device which supports loading and unloading of burdens to a load-carrying platform of a vehicle, it comprises a receiving table which lifts between height of a floor of the load-carrying platform and grounding height, a caster stopper which is configured so as to make it possible to change to posture such as upright posture which protrudes from receiving plane of the load-carrying platform and lodging posture which composes a part of the receiving plane, a gate sensor which detects whether or not the receiving table has cargo handling posture, a stopper sensor which detects whether the caster stopper has the upright posture, a lamp which notifies that the caster stopper has the upright posture and a control device which controls the lamp. The control device provides the receiving table lifting device which turns off the lamp or outputs notification signal if it is determined on the basis of output of the stopper sensor that the caster stopper has the upright posture and it is determined on the basis of output of the gate sensor that the receiving table has not the cargo handling posture.SELECTED DRAWING: Figure 6

Description

[Technical Field]

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

[0002] The loading platform of a loading platform lifting device may be equipped with caster stoppers (wheel stops) that stand up and protrude from the loading surface to allow for easier loading and unloading of carts. Patent Document 1 discloses a loading platform lifting device that uses a sensor to detect whether the caster stopper is in an upright or collapsed state, and automatically turns on an LED lamp when the caster stopper is in an upright state (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5545649, paragraph 0032 Summary of the Invention [Problem to be solved by the invention]

[0004] Although the power supply to the platform lifting device is turned off by the power switch after use, if the power switch is left on, the power supply may remain on even after use. In the platform lifting device of Patent Document 1, if the caster stoppers are forgotten to be lowered when the platform lifting device is finished being used, the lamps on the platform lifting device may remain lit while the vehicle is moving if the power switch remains on. The same problem may also occur if the caster stoppers are deformed or the sensor does not detect that the caster stoppers are in the lowered position even after they are lowered.

[0005] SUMMARY OF THE INVENTION An object of the present invention is to provide a platform lifting device that can prevent a lamp from turning on while the vehicle is moving. [Means for solving the problem]

[0006] 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 device comprising: a loading platform that moves up and down between the height of the floor surface of the loading platform and the height at which it touches the ground; caster stoppers that are configured to be able to change their 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 gate sensor that detects whether the loading platform is in a loading position; a stopper sensor that detects whether the caster stoppers are in an upright position; a lamp that notifies that the caster stoppers are in an upright position; and a control device that controls the lamp, wherein the control device determines that the caster stoppers are in an upright position based on the output of the stopper sensor. Even if It is determined that the loading platform is not in a loading position based on the output of the gate sensor. sometimes , turn off the lamp or A loading platform lifting device that outputs a warning signal is provided. [Effects of the Invention]

[0007] According to the present invention, it is possible to prevent the lamp of the platform lifting device from turning on while the vehicle is traveling. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view showing a state in which a loading platform lifting device according to an embodiment of the present invention is mounted on a vehicle; [Figure 2] 1 is a side view of a loading platform lifting device according to an embodiment of the present invention; [Figure 3] Cross section along line AA in Figure 2 [Figure 4] Cross section along line AA in Figure 2 [Figure 5] 1 is a block diagram of a control device provided in a loading platform lifting device according to an embodiment of the present invention; [Figure 6] 1 is a flowchart showing a ramp control procedure performed by a control device provided in a loading platform lifting device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0010] -Load receiving platform lifting device- Fig. 1 is a perspective view showing a loading platform lifting device according to one embodiment of the present invention mounted on a vehicle, Fig. 2 is a side view of the loading platform lifting device according to one embodiment of the present invention, and Figs. 3 and 4 are cross-sectional views taken along line AA in Fig. 2. Fig. 3 shows an example of a ramp, which will be described later, and Fig. 4 shows another example. In this specification, the terms "front and rear" refer to the front and rear of the loading platform lifting device, and in this embodiment correspond to the front and rear of the vehicle.

[0011] The loading platform lifting device 1 shown in Fig. 1 is a device that assists in loading and unloading of luggage onto a vehicle loading platform 101. This loading platform lifting device 1 includes a base frame 2 attached to the bottom of the vehicle frame 100, left and right arms 3 connected to the base frame 2, a loading platform 4 connected to the tips of the left and right arms 3, and a hydraulic cylinder 5 that raises and lowers the loading platform 4.

[0012] The base frame 2 includes a frame body 11 and a bumper 14. The frame body 11 supports the arms 3, the hydraulic cylinder 5, and the loading platform 4, and is connected to the lower part of the vehicle frame 100 via a bracket 16. The bumper 14 is supported at the rear of the frame body 11 and is composed of left and right bumpers 14A and a central bumper 14B. The bumpers 14A, 14B are aligned horizontally along a straight line extending left and right, and a gap is secured between the left and right bumpers 14A and the central bumper 14B to allow the left and right arms 3 and the hydraulic cylinder 5, which rotate up and down, to pass through.

[0013] The arm 3 is configured by combining a plurality of links, has a parallel link mechanism and a tilt link mechanism, and is connected to the base frame 2 via pins 6 and 7.

[0014] When the loading platform 4 is stored, it takes an upright position along the rear surface of the vehicle's loading platform 101 as shown in FIG. 1. When the operating device 27 (FIG. 5) is operated to retract the hydraulic cylinder 5, it is deployed to a loading position with the loading surface facing upward (horizontal) at the height of the floor of the loading platform 101. When the hydraulic cylinder 5 is further retracted, the loading platform 4 descends in the loading position to the height at which it touches the ground as shown in FIG. 2. When the hydraulic cylinder 5 is further retracted while the loading platform 4 is on the ground, the loading platform 4 tilts backward to a position inclined downward, and the tip of the loading platform 4 touches the ground. When the hydraulic cylinder 5 is extended, the loading platform 4 operates in the opposite manner to the above. In this way, the loading platform 4 is raised and lowered by the hydraulic cylinder 5 between the height of the floor of the loading platform 101 and the height at which it touches the ground, and is also moved to a storage position or a loading position at the height of the floor of the loading platform 101.

[0015] The receiving platform lifting device 1 is equipped with a gate sensor 20 (FIG. 5) that detects whether the receiving platform 4 is in a loading position. This gate sensor 20 turns on, for example, when the receiving platform 4 is in a loading position (or vice versa). The gate sensor 20 may be a non-contact sensor such as a proximity sensor, but a contact sensor such as a limit switch may also be used. The gate sensor 20 may also be a sensor such as an angle meter that detects the angle of the gate sensor 20 relative to the arm 3, or an IMU that detects the angle of the receiving platform 4 relative to the direction of gravity.

[0016] The loading posture of the loading platform 4 refers to a state in which the loading surface is parallel to the floor of the loading platform 101 (or the angle difference with the floor is less than a set angle), but in reality it is the angle range of the loading platform 4 in which the gate sensor 20 turns on. In a configuration in which the gate sensor 20 turns off when the loading platform 4 is in the loading posture, the angle range of the loading platform 4 in which the gate sensor 20 turns off is the loading posture. Therefore, the angle range of the loading posture is adjusted by setting the angle of the loading platform 4 in which the gate sensor 20 turns on (or off). In particular, in the case of models in which the angle of the loading platform 4 relative to the arm 3 can be adjusted during loading and unloading operations, the loading posture is not necessarily a constant angle, so in such models it is desirable to provide a range for the angle of the loading posture detected by the gate sensor 20.

[0017] - Caster stopper - The loading platform 4 is provided with caster stoppers 30 that act as wheel stops to allow for easier loading and unloading of dollies and the like. The caster stoppers 30 are located at the rear of the loading platform 4 and extend in the left-right direction. They are used by standing upright at the rear of the dolly loaded on the loading platform 4.

[0018] The caster stopper 30 has a rear portion connected to the receiving platform 4 via a pin 31, and a front portion that can rotate up and down to change its position between an upright position and a lying position. Specifically, in this embodiment, the storage section 4a (the rearmost hollow of the multiple hollow sections present in the receiving platform 4) of the receiving platform 4 is open to the receiving surface over its entire length on the left and right, and the caster stopper 30 opens and closes the upper opening of the storage section 4a between the left and right side moldings 28 (FIG. 2). With this configuration, in the lying position (indicated by the two-dot chain line in FIG. 4), the caster stopper 30 closes the upper opening of the storage section 4a in the receiving platform 4 and forms part of the receiving surface of the receiving platform 4, and in the upright position (FIGS. 2-4), it protrudes upward from the receiving surface of the receiving platform 4 and functions as a rear wheel stopper.

[0019] 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 device 1 is provided with a locking device (not shown) that restrains the caster stopper 30 in the lying position.

[0020] The loading platform lifting device 1 is also equipped with a stopper sensor 40 (FIG. 5) that detects the position of the caster stopper 30, i.e., whether it is in a lying position or an upright position. This stopper sensor 40 is, for example, on when the caster stopper 30 is in a lying position and off when it is in an upright position (or vice versa). The stopper sensor 40 can be a non-contact sensor such as a proximity sensor, but a contact sensor such as a limit switch can also be used.

[0021] -lamp- The loading platform lifting device 1 is equipped with a lamp 45 that indicates that the caster stopper 30 is in the upright position. A typical example of the lamp 45 is an LED, but it can also be replaced with various light-emitting devices that emit light when powered. A plurality of lamps 45 are installed, for example, spaced apart in the left-right direction. The lamps 45 can be installed in the storage section 4a of the caster stopper 30 on the loading platform 4 or on the caster stopper 30 (for example, on the back surface). When the lamp 45 is installed on the back surface of the caster stopper 30, as well as when the lamp 45 is installed on the storage section 4a, the upper opening is blocked by the cast stopper 30, and the lamp 45 is stored in the storage section 4a, which is a substantially closed space, when the caster stopper 30 is in the laid-down position.

[0022] As a specific example, as shown in the example of Fig. 3, the lamp 45 can be installed in the storage section 4a of the load-receiving platform 4 so as to shine light from the front onto the front surface of the caster stopper 30 in the upright position, illuminating the caster stopper 30. In the example of Fig. 3, the caster stopper 30 can be provided with a window 32, and part of the light emitted by the lamp 45 can be transmitted rearward through the window 32 of the caster stopper 30 in the upright position. A plurality of windows 32 are provided on the left and right sides corresponding to the lamps 45. In this case, the reflected light from the caster stopper 30 notifies a person in front of the caster stopper 30 that the caster stopper 30 is upright. At the same time, the transmitted light (direct light) that passes through the window 32 notifies a person behind the cast stopper 30 that the cast stopper 30 is upright.

[0023] Furthermore, the installation form of the lamp 45 can be changed as appropriate. For example, as shown in the example of Fig. 4, the lamp 45 can be installed facing upward on the bottom surface of the storage section 4a of the loading platform 4, and light can be configured to directly pass through the upper opening of the storage section 4a, which is opened when the caster stopper 30 is raised. In the example of Fig. 4, the fact that the caster stopper 30 is raised is mainly indicated by direct light from the lamp 45. However, because some of the light emitted by the lamp 45 illuminates the caster stopper 30, it is also possible to indicate that the caster stopper 30 is raised by reflected light, as in the example of Fig. 3.

[0024] -Control device- FIG. 5 is a block diagram of a control device provided in a platform lifting device according to one embodiment of the present invention.

[0025] The platform lifting device 1 is equipped with a control device 50 that controls the lamps 45. This control device 50 is provided, for example, in the power unit 26 (FIG. 1) of the platform lifting device 1. The control device 50 is connected to the platform lifting device 1 or the vehicle's battery (power source) 57 via a power switch 58, and the power switch 58 turns the power of the control device 50 on and off. The power switch 58 is installed, for example, in the vehicle's driver's cab or the power unit 26.

[0026] The control device 50 is a computer such as a microcomputer, and includes an input unit 51, a storage unit (memory) 52, a calculation unit (CPU) 53, and an output unit 54. The input unit 51 receives outputs (detection signals) from various sensors mounted on the platform lifting device 1, such as the gate sensor 20 and the stopper sensor 40, and operation signals from the operation device 27. The storage unit 52 stores various data, such as an operation control program for the platform lifting device 1 and control thresholds. The calculation unit 53 executes processing in accordance with the program stored in the storage unit 52 and generates control signals for controlling the hydraulic cylinder 5 (strictly speaking, a solenoid valve that drives the hydraulic cylinder 5) and the lamp 45 based on the sensor outputs and operation signals. The control signals generated by the calculation unit 53 are output to the solenoid valve and the lamp 45 via the output unit 54 as appropriate.

[0027] In particular, in this embodiment, the control device 50 turns off the lamp 45 when it determines that the caster stopper 30 is in an upright position based on the output of the stopper sensor 40 and when it determines that the loading platform 4 is not in a loading position based on the output of the gate sensor 20 (described below).

[0028] The operating device 27 is a device for raising and lowering the loading platform 4 during loading and unloading work to command the operation of the hydraulic cylinder 5, and is equipped with an up switch 27A and a down switch 27B. The up operation for raising the loading platform 4 and the storage operation for standing the loading platform 4 up from the loading position are commanded by the up switch 27A. The down operation for lowering the loading platform 4 and the unfolding operation for folding the loading platform 4 down to the loading position are commanded by the down switch 27B.

[0029] -Operation- Fig. 6 is a flowchart showing the lamp control procedure performed by a control device provided in a receiving platform lifting device according to one embodiment of the present invention. As mentioned above, the control device 50 controls the lamp 34 in accordance with the outputs of the stopper sensor 40 and the gate sensor 20. An example of this procedure will be explained below with reference to Fig. 6. The procedure in Fig. 6 is repeatedly executed at short intervals (e.g., 0.1 seconds) while the control device 50 is energized, specifically while the power switch 58 is ON (while the contacts of the power switch 58 are closed).

[0030] 6 starts, the control device 50 first inputs signals from the stopper sensor 40 and the gate sensor 20 (step S1), and determines whether the caster stopper 30 is in an upright position based on the output of the stopper sensor 40 (step S2). If it is determined that the caster stopper 30 is in a lying position, the control device 50 stops the power supply to the lamp 45 to turn it off (step S4), and returns the procedure to step S1.

[0031] If it is determined that the caster stopper 30 is in an upright position, the control device 50 determines whether the loading platform 4 is in a non-loading position based on the output of the gate sensor 20 (step S3). The non-loading position refers to an angle of the loading platform 4 that is not detected as a loading position by the gate sensor 20, and includes the storage position in which the loading platform 4 is upright along the rear surface of the loading platform 101, as well as the position (angle) at the time of transition from the loading position to the storage position, and the position (angle) at the time of transition from the storage position to the loading position. All of these non-loading positions are useful as targets for determination because they are positions in which the caster stopper 30 is not in use.

[0032] When the loading platform 4 is in the loading position, that is, when the caster stopper 30 is in the upright position and the loading platform 4 is in the loading position, the control device 50 outputs a control signal (supplies power) to the lamp 45 to turn on the lamp 45 (step S5), and the procedure returns to step S1. The lighting mode is not limited to continuous lighting, and any mode that makes it easy for those around to recognize that the caster stopper 30 is upright, such as intermittent lighting (flashing) or changing the lighting color, can be appropriately adopted.

[0033] Conversely, if the loading platform 4 is in a non-loading position, that is, if the caster stopper 30 is in an upright position but the loading platform 4 is not in a loading position, the control device 50 outputs a control signal to the lamp 45 (stops power supply) to turn off the lamp 45 (step S4), and returns the procedure to step S1.

[0034] While power is being supplied, the control device 50 repeatedly executes the above procedure. When the power switch 58 is turned off, power to the control device 50 is stopped and power supply to the lamp 45 is also disabled, so the lamp 45 goes out.

[0035] Note that the control of the lamp 45 by the control device 50 may be performed using an algorithm that turns off the lamp 45 if the caster stopper 30 is in an upright position but the receiving platform 4 is in a non-loading position. As long as this rule is not violated, the order of determining the position of the caster stopper 30 (step S2) and the position of the receiving platform 4 (step S3) may be reversed. Furthermore, if the receiving platform 4 is in a loading position, the lamp 45 may be turned on even if the caster stopper 30 is in a collapsed position. Alternatively, the lamp 45 may be turned on (step S5) when it is detected that the caster stopper 30 is in an upright position (step S2). However, even in this case, the lamp 45 is turned off (step S4) when it is detected that the caster stopper 30 is in an upright position and the receiving platform 4 is in a non-loading position.

[0036] -effect- (1) According to this embodiment, when the caster stopper 30 is in the upright position and the loading platform 4 is not in the loading position, the lamp 45 is turned off. Therefore, if the caster stopper 30 is forgotten to be lowered when the loading platform lifting device 1 is finished being used, the lamp 45 will be turned off if the loading platform 4 is in the non-loading position, even if the power switch 58 remains on after use of the loading platform lifting device 1. Therefore, when the vehicle is traveling with the loading platform 4 in the stored position, the lamp 45 is turned off regardless of the position of the caster stopper 30, and it is possible to avoid the lamp from being turned on while traveling.

[0037] (2) By providing the lamp 45 on the storage section 4a of the cargo receiving platform 4 or on the back surface of the caster stopper 30, the lamp 45 can be stored in the storage section 4a whose upper opening is covered by the caster stopper 30 by placing the caster stopper 30 in a lying position. This protects the lamp 45, and even if the lamp 45 is turned on unintentionally due to a malfunction in the electrical system, the light emitted by the lamp 45 can be blocked by the caster stopper 30.

[0038] (3) Furthermore, as shown in Figure 3, if lamps 45 are installed to illuminate caster stoppers 30 in an upright position, caster stoppers 30 can be made to appear three-dimensional at night or in dark places. In this case, as shown in the figure, if a window 32 is provided in caster stoppers 30 and some of the light from lamps 45 is configured to pass through window 32 of cast stoppers 30 in an upright position, it can be displayed both in front and behind that cast stoppers 30 are upright.

[0039] (4) As shown in Figure 4, if a lamp 45 is provided so as to pass through the upper opening of the storage section 4a, which is opened when the caster stopper 30 is raised, direct light from the lamp 45 is irradiated upward, making it easier for workers standing near the caster stopper 30 to recognize the raised position of the caster stopper 30.

[0040] -Variations- Although an example has been described in which the lamp 45 is provided on the storage section 4a or the caster stopper 30, the lamp 45 does not necessarily have to be provided on the storage section 4a or the caster stopper 30, and the lamp 45 may be provided on the receiving platform lifting device 1. For example, the lamp 45 may be provided on the left or right end face of the receiving platform 4.

[0041] In the above-described embodiment and modified example, a means for turning off the lamp 45 to prevent it from being illuminated while the vehicle is moving has been described. However, instead of directly turning off the lamp 45, a means for outputting a notification signal (a signal for notification) to an alarm device to prompt the alarm device to turn off the lamp may be employed. For example, an alarm device (speaker, buzzer, etc.) installed in the driver's cab may sound when the non-loading position of the loading platform 4 and the upright or non-downright position of the caster stopper 30 are detected. This notification is not limited to sound, and may be replaced by other methods, such as a display on an alarm device (monitor, lamp, etc.) installed in the driver's cab. Alternatively, a storage device (memory device) installed in the control device 50 may be configured to record data on the illumination state of the caster stopper 30 while the vehicle is moving, allowing the data to be checked during maintenance, etc. Furthermore, the recorded data may be output to a terminal device owned by an operator, etc. Compared to a case where lamp 45 of caster stopper 30 is automatically turned off, this configuration is more useful in terms of alerting workers who have forgotten to lower caster stopper 30. Of course, each of these means may be combined with a means for directly turning off lamp 45.

[0042] Furthermore, while the present invention has been described as being applied to a platform lifting device in which the platform is positioned upright along the wall of the vehicle's loading platform during storage, the present invention can also be applied to other types of platform lifting devices. For example, some platform lifting devices retract the platform into the rear underside of the vehicle frame for storage. There are also platform lifting devices in which the platform is raised and lowered along vertically extending posts, rather than by pivoting an arm. The present invention can also be applied, and similar effects can be achieved, when the platform of these platform lifting devices is equipped with caster stoppers and lamps that indicate the upright position. [Explanation of symbols]

[0043] 1...load receiving platform lifting device, 4...load receiving platform, 4a...storage section, 20...gate sensor, 30...caster stopper, 32...window, 40...stopper sensor, 45...lamp, 50...control device, 101...loading platform

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 gate sensor that detects whether the loading platform is in a loading position; a stopper sensor that detects whether the caster stopper is in an upright position; a lamp that indicates that the caster stopper is in an upright position; a control device for controlling the lamp, The control device turns off the lamp or outputs a warning signal when it determines that the caster stopper is in an upright position based on the output of the stopper sensor, but determines that the loading platform is not in a loading position based on the output of the gate sensor. A loading platform lifting device characterized by the above.

2. The loading platform lifting device according to claim 1, The loading platform lifting device is characterized in that the ramp is provided in a caster stopper housing or on the caster stopper.

3. The loading platform lifting device according to claim 1, The lamp is provided to illuminate the caster stopper in the upright position.

Images