JP5500720B2 - Loading platform lifting device - Google Patents

Description

  The present invention relates to a load receiving table lifting device including a load receiving table that moves up and down between a ground and a load carrier.

  The load receiving platform lifting / lowering device is provided with a hydraulic control device that controls the lifting operation of the load receiving platform. An operator sends a command for lifting / lowering operation of the load receiving platform to the hydraulic control device. Go up and down between and the ground. The raising / lowering operation command is issued via an operating device provided with an ascending or descending switch. Some of the operating devices are of a size that can be gripped by an operator, for example, and the operator can easily move up and down while holding the operating device and observing the movement of the load receiving platform.

As the lifting / lowering operation is simplified in this way, the load receiving device lifting / lowering device can be operated safely. However, when the device is used for a long time, the components (acting hydraulic pumps, motors, valves, etc.) that actually operate the load receiving table. ) And hydraulic oil deteriorates, and the lifting performance gradually decreases. As a countermeasure, maintenance such as replacement of these parts and hydraulic oil is performed. However, the frequency of use of the load receiving platform lifting / lowering device varies depending on the amount and size of the baggage to be transported or when to use it. For this reason, it is difficult to perform proper maintenance management, and if the replacement or the like is delayed, there is a possibility that a failure of the load receiving platform lifting apparatus may occur. Therefore, regardless of the usage situation, set the time for replacement in advance,
In many cases, replacement work or the like is often performed at that time.

  In order to efficiently perform maintenance management of such parts and hydraulic oil, a load receiving table lifting device that measures the number of times of driving to raise and lower the load receiving table and displays the number of times of driving on the drive unit has been proposed (Patent Document 1). Thereby, the maintenance management based on the actual number of times of driving is performed, not based on the passage of time.

JP 2009-202659 A

  However, even the configuration proposed in Patent Document 1 or the like has room for improvement in terms of a configuration that allows an operator to easily grasp maintenance management.

  The first factor is that the work such as the above replacement is not frequently performed as the product quality is improved, and the operator does not need to be aware of maintenance management in daily work. For this reason, simply measuring and displaying the number of times of driving does not realize the necessity of maintenance management and the parts are not replaced unless the operator consciously watches the display unit. Moreover, if it is set as the structure which sounds an alarm device so that an operator may notice when the set drive frequency is reached, a loud sound will be generated unexpectedly during work in a town. It is not preferable that a loud noise is generated particularly during night work.

  The second factor is that it is difficult to grasp the necessity of maintenance management during the work or immediately after the work, for example. In many cases, a large load or a precise load is loaded on the load receiving platform, and even if a display section such as the number of times of driving is provided in the load receiving platform lifting / lowering device, various places are likely to be blind spots due to the loaded load. Even if a display unit is provided in the hydraulic control device, since the device is provided on either the left or right side of the vehicle below the loading platform, it is complicated to always check. In particular, the operator moves to the display unit to view the display unit even though he / she is operating away from the load receiving unit lifting / lowering device so that he / she can operate while looking over the entire cargo receiving platform lifting / lowering unit. It is not preferable in terms of work efficiency.

These factors arise because the use of the cargo receiving platform lifting / lowering device is performed in a limited time and space by an operator at a location moved by the vehicle. Also, if maintenance management is not grasped on a daily basis, parts cannot be exchanged even if a person notices that the vehicle has deteriorated over time in a place moved by a vehicle for a long distance.
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a load receiving table lifting device that allows an operator to easily grasp maintenance management.

In the present invention, a load receiving base that is provided at the rear of the vehicle and moves up and down between the loading platform and the ground, an operating means that includes a hydraulic control device that drives the loading platform to move up and down, and an operation that outputs an operation command for the load receiving platform. The hydraulic control device includes a control unit that operates the operating unit , and a detection that is connected to the control unit and detects a state based on secular change of the operating unit. And a transmission unit that transmits a signal based on detection data from the detection unit, and the controller device is connected to the input unit to which an output signal from the transmission unit is input, and the input unit It shall have an information part.

Here, the “operating means” means a driving means (for example, a motor) that drives the hydraulic control device, a vehicle battery that is a driving source of the driving means, or a hydraulic cylinder, hydraulic oil, or hydraulic oil related to the lifting operation of the load receiving platform. This refers to a switching valve provided in a hydraulic circuit for supplying or a member such as an arm used for raising and lowering the load receiving table. Further, the "predetermined operating state" refers to an index indicating the aging of these actuating means, for example, managed and elevated temperature due to the driving of the motor, the temperature and viscosity of the hydraulic oil, receiving platform of the lift such as the number It is the structure which can do .

Such a hydraulic control device has a control unit that operates the operating means, and a signal based on detection data by the detection unit is output to the transmission unit after passing through the control unit. Is desirable.
Furthermore, it is desirable that a storage unit is connected to the detection unit, and the detection data detected by the detection unit is stored by the storage unit.

  In addition, the hydraulic control device may have a configuration in which a signal based on the detection data is transmitted from the transmission unit in response to an output from the operation device.

The state detection based on the secular change of the operating means may be performed based on the number of times the operating means is driven. The predetermined driving state may be detected based on the number of times of driving and the driving time of the operating means.
For example, a motor is disposed in the operating means as a power source for supplying hydraulic pressure, and the detection of the state based on the secular change of the operating means may be temperature detection of the motor.

  According to the present invention, the detection unit detects the predetermined operation state of the operation unit, and the information detected by the detection unit is sent to the notification unit of the operating device via the transmission unit. Easy to grasp. Therefore, maintenance management can be performed accurately.

It is the perspective view and side view which show the drive of the cargo receiving stand raising / lowering apparatus which concerns on this embodiment. It is a hydraulic circuit diagram of the load receiving table lifting device according to the present embodiment. It is a schematic diagram which shows the structure of the hydraulic control apparatus and operating device which concern on this embodiment. It is a flowchart which shows the procedure which detects the drive state of a hydraulic control apparatus. It is a schematic diagram explaining utilization of the drive state of a hydraulic control apparatus. It is a flowchart which shows the detection procedure which concerns on 2nd Embodiment.

DESCRIPTION OF EMBODIMENTS Embodiments of a load receiving table lifting apparatus according to the present invention will be described with reference to the drawings.
(First embodiment)

  As shown in FIG. 1 (a), the load receiving platform lifting / lowering device 100 is mounted on the rear side of the vehicle, and is stored in the load receiving stand 2 stored in a standing state along the rear door 1 a of the load box 1 and the load receiving stand 2. A hydraulic control device 4 that controls the lifting operation of the load receiving table 2 via the connected parallel link arm 3, and an operation device 5 that outputs a command for the lifting operation of the load receiving table 2 to the hydraulic control device 4. Yes.

As shown in FIG. 1 (b), the load receiving platform 2 is stowed and stowed ( solid line portion 2a) when the vehicle is running, and is rotated (arrow A1) when the load receiving platform lifting / lowering device 100 is used. At a height of 1b, a horizontal state ( one-dot chain line portion 2b) is obtained. The load receiving platform 2 is further moved up and down along the arrow A2 to be in a grounded state (two-dot chain line portion 2c) and in a state where the tip of the load receiving table is inclined downward (arrow A3) (one-dot chain line portion 2d). This lifting operation loads and unloads the load between the loading platform and the ground.

  The parallel link arm 3 has a pair of left and right ends and a tip end portion connected to the load receiving platform 2 and a base end portion attached to a support member (not shown) in the lower rear portion of the vehicle. The tilt link 3a, the tension arm 3b, and the compression arm 3c. A link arm 3d and a lift cylinder 3e are provided.

The tilt link 3a extends in the vertical direction, and an upper part thereof is rotatably connected to an upper part of the support bracket 11 via a pin, and a lower part is formed to be swingable in the vehicle front-rear direction. Tension arm 3b is base end rotatably connected to via a pin on the top of the tilt link 3a, the tension arm 3b tip is rotatably connected to the upper end of the receiving platform 2. The tension arm 3b extends in the vehicle front-rear direction, and one end (base end) on the vehicle front side is rotatably connected to the upper end portion side of the tilt link 3a via a pin, and the other end (tip end) on the vehicle rear side is It is connected to the load receiving stand 2 through a pin so as to be freely rotatable. The compression arm 3c extends in the vehicle front-rear direction below the tension arm 3b, and one end (base end) on the vehicle front side is a pin between the support bracket 11 and the bracket piece 12 facing the support bracket 11 from the outside. The other end (front end) on the rear side of the vehicle is rotatably connected to the lower end portion of the link arm 3d via a pin. The upper end of the link arm 3d is pivotally supported by a pin together with the distal end of the tension arm 3b on the base end side of the load receiving platform 2 so as to be freely rotatable. The distal end of the compression arm 3c is connected to the base end side of the load receiving platform 2 via the link arm 3d. The lift cylinder 3e is a hydraulic cylinder and extends in the vehicle front-rear direction below the compression arm 3c. One end (base end) of the lift cylinder 3e on the vehicle front side is rotatably connected to the lower end of the tilt link 3a via a pin, and the other end (tip end) on the vehicle rear side is connected to a substantially middle portion of the compression arm 3c. It is rotatably connected via a pin.

  When the load receiving platform 2 is in the upright retracted state 2a, the lift cylinder 3e is extended, and is manually rotated in the extended state to bring the load receiving platform 2 into the horizontal state 2b. When the lift cylinder 3e is contracted, the load receiving platform 2 is lowered to the grounded state 2c while maintaining the horizontal state, and the lift cylinder 3e is contracted by the weight of the load receiving platform 2, etc. The tip is grounded and tilted.

Although not shown, the hydraulic control device 4 includes an electric motor, a hydraulic pump, a solenoid valve, and the like, and controls the supply of hydraulic oil to the lift cylinder 3e. This control is performed by sending a command from the operator to the hydraulic control device 4 via the operation device 5.

  The operation device 5 is configured such that an electronic component or the like that outputs a signal to the hydraulic control device 4 is covered with a resin case 5a, and an operation button (“up” command) for an operator to send an elevation command of the load receiving platform 2 is provided. And a notifying part 5d for notifying the driving state of the hydraulic control device 4 are arranged to face outward. The operation device 5 is used to input / output signals to / from the hydraulic control device 4.

A radio signal R1 having data of “raising” and “lowering” commands of the load receiving platform 2 is output from the operating device 5 to the hydraulic control device 4, and after receiving the output, the hydraulic control device 4 sends the operation device 5 to the operating device 5. A radio signal R2 having data related to the driving state of the hydraulic control device 4 is output.
The driving of the hydraulic control device 4 will be described with reference to the hydraulic circuit diagram of FIG.

  The suction side of the hydraulic pump P communicates with the oil tank T, and the discharge side communicates with the bottom side of each lift cylinder 3e through the supply path 80. A check valve 81 that allows hydraulic oil to flow from the hydraulic pump P to the lift cylinder 3e is interposed in the supply path 80. Further, a discharge path 82 having a switching valve SOL1 is branched from the first supply path 80 on the lift cylinder 3e side with respect to the check valve 81 and communicates with the oil tank T, and the hydraulic pump P more than the check valve 81. The supply path 80 on the side and the discharge path 82 on the oil tank T side with respect to the switching valve SOL <b> 1 are communicated with an oil path 84 provided with a relief valve 83. The relief valve 83 is configured to open the oil passage 84 by an external pilot pressure from the supply passage 80 that is closer to the lift cylinder 3e than the check valve 81.

The posture change of the load receiving platform 2 will be described. After manually changing the posture from the standing state to the horizontal state, the load receiving stand 2 is lowered by turning on the lowering button 5c. At this time, the switching valve SOL1 is switched to the communication position by the ON operation of the lowering button 5c, the hydraulic oil is pushed away from the bottom side of the lift cylinder 3e, and the lift cylinder 3e is contracted. When the cargo receiving platform 2 is raised, the raising button 5b is turned on. As a result, the motor M is driven and the hydraulic pump P is driven, the hydraulic oil is supplied to the bottom side of the lift cylinder 3e via the supply path 80, and the lift cylinder 3e is extended.
The hydraulic control device 4 thus driven detects the temperature rise of the motor M and notifies the operator.

  As shown in FIG. 3, the hydraulic control device 4 includes a drive unit 4A connected to a vehicle battery B via a main switch SW, and a control unit 4B that drives and controls the drive unit 4A. The drive means 4A includes a relay CT that is closed by an ON operation of the motor M, the switching valve SOL1, or the raising button 5b. Opening and closing of the connection circuit between the battery B and the motor M is controlled by the relay CT. The main switch SW is provided in the vehicle cab and is switched ON or OFF before and after the use of the cargo cradle lifting device.

  The control means 4B includes a detection unit 41 that is connected to or close to the motor M and detects the temperature of the motor M, a storage unit 42 that is connected to the detection unit 41 and stores detection data of the detection unit 41, and A control unit 43 that is connected to the detection unit 41 and outputs a control signal to the driving unit 4A, and a transmission unit 44 that is connected to the control unit 43 and outputs (transmits) a signal based on detection data related to the motor M is provided. Thus, the driving state of the driving means 4A, particularly the temperature rise state of the motor M is monitored. A control notification unit 43a that emits light from a light emitting diode (LED) when the temperature of the motor M exceeds a predetermined value is connected to the control unit 43.

  In addition, the control unit 4B is also provided with a receiving unit 45 that is connected to the control unit 43 and that receives (receives) command data output from the operating device 5, thereby appropriately responding to the operator's command. The raising / lowering operation of the load receiving stand 2 is performed.

  On the other hand, the operation device 5 that performs input / output of signal data to / from the hydraulic control device 4 includes an up button 5b and a down button 5c, a command data output unit 51 that outputs command data to the receiving unit 45, A detection data input unit 52 to which a signal output from the transmission unit 44 is input, a determination unit 53 connected to the detection data input unit 52 to determine the type of input data, and connected to the determination unit 53 to the outside And an informing unit 5d for informing the user.

The detection unit 41 of the control means 4B detects the temperature of the driven motor M and outputs detection data to the storage unit 42 and the control unit 43 in order to grasp a predetermined drive state of the hydraulic control device 4. In the storage unit 42, the detection data (such as the driving time and temperature of the motor M) is stored as the driving history of the motor M. The control unit 43 performs drive control of the drive unit 4 </ b> A in response to command data from the operation device 5 via the reception unit 45, and outputs a signal based on detection data regarding the motor M to the transmission unit 44. The signal output from the transmission unit 44 is data based on whether or not the temperature of the motor M, the rate of temperature increase at a predetermined time, and the like are higher than a preset numerical value (abnormal temperature).

  The detection data input unit 52 of the controller device 5 outputs the signal to the determination unit 53 after inputting the signal output from the transmission unit 44. The determination unit 53 drives the notification unit 5d when the signal is a signal to notify the abnormal temperature, and does not drive the notification unit 5d when the signal is not a notification signal. In addition, although the alerting | reporting part 5d is set as the structure which alert | reports by light-emitting outside with a light emitting diode (LED) etc., the structure which alert | reports by emitting a vibration, the structure which alert | reports by generating a sound, etc. may be sufficient. In the configuration in which the notification is made by sound, since the notification unit 5d is provided in the operating device 5 held by the worker, the operator can be recognized without making a loud sound. In addition, regarding a preset temperature value, a value immediately before the maintenance needs to be performed, a value taking safety into consideration than a value immediately before the maintenance, or the like can be used. Furthermore, it sets so that the alerting | reporting part 5d may be driven for every kind of the value, for example, it sets so that it may alert | report in a different color by the case where it becomes the value which considered safety | security immediately before the value. For example, the notification method may be different for each type. The control notification unit 43a described above is configured to be connected to the control unit 43, but may be configured similarly to the notification unit 5d of the controller device 5.

As described above, since the hydraulic control device 4 and the operation device 5 have a configuration in which data can be input and output with each other, the lift button 5b for the operator to perform the lifting and lowering operation of the load receiving platform 2 is performed. Each time an operation is performed via the down button 5c, information on the temperature of the motor M can be received. Further, since the notification unit 5d is provided in the operation device 5 and an operator often works while holding the operation device 5, information regarding the motor M can be easily recognized at any time during the operation.
The detection by the detection unit 41 of the control means 4B is specifically performed according to the procedure shown in the flowchart of FIG.

When using the load receiving platform lifting / lowering device, the operator switches the main switch SW from OFF to ON (step SS), and then performs the ON / OFF operation (step S1) of the raising button 5b or the lowering button 5c of the operation device 5. As a result, the motor M is driven (step S2). Detector 41 detects the temperature of the motor M being driven (step S3), and the detection data is output to the storage unit 42 and the control unit 43. When the operator turns off the raising button 5b or the lowering button 5c to stop the lifting operation of the cargo receiving platform 2 (step S4), the detection data input from the detection unit 41 in the control unit 43 after receiving the OFF signal. Judgment is made. Specifically, it is determined whether or not the temperature of the motor M is equal to or higher than a preset temperature as to whether or not the state of the motor M is to drive the notification unit 5d (step S5). If it is determined that the state should be driven, a signal (notification signal) for driving the notification unit 5d is output to the transmission unit 44 (step S6), and if it is determined that it is not necessary to drive the notification unit 5d, non-notification is performed. A signal is output (step S6a). By inputting these signals, the notification unit 5d is driven or not driven (steps S7 and S7a). Thus, the detection unit 41 performs temperature detection every time the motor M is driven, and the notification unit 5d receives a notification signal or a non-notification signal every time the motor M is driven. Further, when the up button 5b or the down button 5c of the operation device 5 is turned on or off again, the driving or non-driving control of the notification unit 5d is repeated in the same procedure.

  Next, when the ON / OFF operation (steps S1 to S41) of the raising button 5b or the lowering button 5c of the operating device 5 is repeated a predetermined number of times so as to repeat the raising and lowering of the cargo receiving platform 2 at one place, the control unit 43 Thus, the ratio between the driving time of the motor M and the temperature rise is analyzed. If this analysis value is equal to or greater than a preset value, it is output to the transmission unit 44 as a notification signal, and if it is smaller than the set value, it is output to the transmission unit 44 as a non-notification signal. For example, the raising / lowering operation of the load receiving platform 2 may be performed continuously at the place where the vehicle is stopped. When the load receiving platform lifting / lowering device 100 is excessively continuously operated or when aged deterioration has progressed, such continuous lifting / lowering operation also becomes a factor for advancing the timing of maintenance. Therefore, if the notification unit 5d is driven using the analysis result of the driving time of the motor M and the temperature rise, the operator can use the operating device 5 for the necessity of maintenance even when the usage is the same as before. You can see and recognize. The notification unit 5d is also used to notify that the temperature of the motor M is equal to or higher than the set value and that the ratio between the drive time and the temperature rise is equal to or higher than the set value. It is also possible to provide a plurality of and notify each individually.

Moreover, since the information of the data detected by the detection unit 41 is stored in the storage unit 42 of the control means 4B, as shown in FIG. It is also possible to connect a device for extracting detection data stored in the storage unit 42 (for example, a personal computer PC) to verify and analyze the stored detection data. By conducting verification and analysis in this way, it is possible to estimate a more appropriate maintenance time. Further, since the detection data is stored in the storage unit 42, even if the operator himself / herself does not store the notification in the notification unit 5d, appropriate maintenance can be performed by checking the stored data in the storage unit 42. Is also possible.
(Second Embodiment)
In the present embodiment, the driving procedure of the notification unit 5d is different from that in the first embodiment, and the description will focus on the different parts.

As shown in FIG. 6, the control means 4 </ b> B (see FIG. 3) provided with the detection unit 41 repeatedly outputs the non-notification signal and outputs the temperature of the motor M when the temperature of the motor M is lower than the set value. Perform detection. When the temperature of the motor M is detected by the detection unit 41 and the control unit 43 determines that the temperature of the motor M is equal to or higher than the set value when the operation button is turned off (for example, the raising button 5b is turned off) (steps S3 and S4). The transmitter 44 outputs a notification signal for driving the notification unit 5d (step S6). On the other hand, when the temperature of the motor M is lower than the set value, the control unit 43 does not output a signal to the transmission unit 44. That is, the signal output from the transmission unit 44 to the detection data input unit 52 of the operation unit 5 is performed only when the notification unit 5d is driven. Therefore, in this embodiment, it can be set as the structure in which the operation means 5 is not provided with the determination part 53. FIG.
(Other matters)

  The detection unit 41 detects the temperature of the motor M as a representative example of detecting a predetermined state of the hydraulic control device 4, but the detection target is not limited to this, and the driving means 4A of the hydraulic control device 4 is not limited thereto. If it is an operation means comprised by the other member etc. regarding the raising / lowering operation | movement of the cargo receiving stand 2, the predetermined operation state of the operation means can be made into a detection target.

  For example, the voltage of the battery B that is one of the operating means other than the driving means 4A may be detected. Accordingly, it is possible to determine the aging deterioration of the motor M, the battery B, or the like by detecting the voltage fluctuation with respect to the operation command of the load receiving platform 2 via the operation device 5. At this time, the detection unit 41 is configured to be connected to the battery B.

  Moreover, it is good also as a structure which detects the switching valve SOL1. For example, if an operation command through the operation device 5 and the switching time of the insertion or blocking state of the switching valve SOL1 are detected as indicators, it is possible to determine the deterioration over time.

  Furthermore, you may provide the detection part which detects the hydraulic pressure of hydraulic fluid. By detecting the hydraulic pressure, it is possible to detect whether or not the load on the load receiving platform 2 is overloaded, and the information is notified, and the lifting operation of the load receiving platform 2 is repeatedly performed in the overloaded state. It is also possible to notify this. Moreover, it is good also as a structure which alert | reports replacement | exchange of hydraulic fluid if the deterioration state of hydraulic fluid is detected and it will be in a predetermined state.

  In addition, you may provide the detection part 41 which measures the frequency | count of raising / lowering of the cargo receiving stand 2 as an object which detects the state of a predetermined | prescribed operating means. In many cases, the load receiving platform 2 measures the lifting / lowering operation between the height of the loading platform floor and the height at which it contacts the ground as one time, but it does not measure only the number of times, but also measures the number of continuous lifting operations. These can also be used as indicators for determining the maintenance time. By measuring the number of times of raising / lowering, the raising / lowering time, or the raising / lowering speed, it is also possible to grasp the deterioration of the motor M, hydraulic oil, or the like.

  With respect to the various notification targets described above, a configuration in which notification is performed individually or a detection target that is a combination thereof may be used as an index. Moreover, you may provide the alerting | reporting part corresponding to the number of each alerting | reporting object, respectively.

  The operation device 5 is configured to input and output signals to and from the hydraulic control device 4 via wireless radio waves, but is not limited thereto. For example, if a signal can be input / output to / from the hydraulic control device 4, an operating device connected to the hydraulic control device 4 by wire can be used.

  The number of operation buttons provided on the operation device 5 is only two, that is, the up button 5b and the down button 5c. However, the number is not limited to two, and may be three or more or one.

  With respect to the type of the load receiving platform lifting device 100, the load receiving stand 2 is stowed and stored behind the load box and the load receiving stand 2 is manually rotated from the standing state to the horizontal state. However, the present invention is not limited to this. For example, it may be one that automatically rotates according to a command via the operation device 5. What stored in the lower part of a packing box, what is stored in a packing box, or what raises / lowers substantially perpendicularly with respect to the ground may be used.

  The present invention is useful for all types of cargo receiving platform lifting devices including a hydraulic control device and an operation device.

DESCRIPTION OF SYMBOLS 1 Cargo box 2 Cargo stand 3 Parallel link arm 4 Hydraulic control apparatus 4A Driving means 4B Control means 41 Detection part 42 Storage part 43 Control part 44 Transmission part 45 Receiving part 5 Operation apparatus 51 Command data output part 52 Detection data input part 53 Determination Part 5b Raise button (operation button)
5c Down button (operation button)
5d Notification unit M Motor B Battery

Claims (5)

A load receiving base that is provided at the rear of the vehicle and moves up and down between the loading platform and the ground, an operating means including a hydraulic control device that drives the lifting operation of the load receiving platform, and outputs an operation command for the load receiving platform and is held by an operator a receiving platform lifting device and an operation device that is, the hydraulic control device includes a control unit for operating said actuating means, a state based on aging of said actuating means is connected to the control unit A detection unit that detects the signal and a transmission unit that transmits a signal based on detection data from the detection unit; and the operation device includes: an input unit that receives an output signal from the transmission unit; possess the connected notification unit, the transmission of the transmission signal based on the detected data to the input unit of the operating device from the transmitting portion of the hydraulic control device is performed, and the transmission signal received at the operating device based on By known signal or a non-sensing signal, receiving platform lifting device, characterized in that it notification is performed by the notification unit. A storage unit is connected to the detection unit, and the detection data detected by the detection unit is stored by the storage unit, and a signal based on the detection data by the detection unit passes through the control unit and then The cargo receiving platform lifting / lowering device according to claim 1, wherein the cargo receiving platform lifting / lowering device is output to a transmission unit. By the detection signal or the non-detection signal in front Kimisao operation device, receiving platform lifting apparatus according to claim 1 or 2, characterized in that at least two types of notification can be performed by the notification unit. The load receiving platform elevating device according to claim 3, wherein the detection of the state based on the secular change of the operating means is performed based on at least one of the number of driving times and the driving time of the operating means. 5. The motor according to claim 1, wherein a motor is disposed as a power source for supplying hydraulic pressure to the operating means, and the detection of the state based on the secular change of the operating means is temperature detection of the motor. The load receiving table lifting device according to any one of the above.

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