Electric cargo handling equipment

Abstract

To provide an electric cargo handling device that can transport cargo smoothly and quickly without causing impact to the cargo during ground clearance, regardless of the operator's skill level. [Solution] The electric cargo handling device 100 has a main body 1 and an operating means 17. The main body 1 has a storage unit 11 that stores a target position for raising and lowering the suspension member 24 and a control unit. The operating means 17 includes a switch 18 that inputs an instruction to store the target position in the storage unit 11 and a switch 19 that inputs an instruction to raise and lower the suspension member 22 to the target position. By operating the switch 18, a first target position for raising the suspension member 22 can be stored in the storage unit 11. By operating the switch 19, the control unit executes a first cargo handling operation playback function in which the suspension member 22 rises at a low speed from when the suspension member 22 starts to rise until the cargo 24 is lifted off the ground, and then the suspension member 22 rises at a high speed toward the first target position after the cargo 24 has been lifted off the ground.

Description

Technical Field

[0001] The present invention relates to an electric cargo handling device that includes a lifting mechanism such as a winding type using a wire or a load chain or a multi-joint arm type, and vertically lifts and transports a cargo by operating means such as an operation grip or an operation pendant switch.

Background Art

[0002] Conventional electric cargo handling devices are described in Patent Documents 1 and 2. The electric cargo handling device described in Patent Document 1 has a function of prestoring a plurality of different working positions in a working position teaching unit and playing back the working positions stored in the working position teaching unit by operating a position playback switch, thereby facilitating positioning work and alignment operations.

[0003] The electric cargo handling device described in Patent Document 2 includes a load / no-load detection sensor. When operating the lift switch to lift the suspended load, first operate the electric motor at a high-speed lift speed. When the load / no-load detection sensor detects the load of the suspended load, at the time of lifting off the ground of the suspended load, that is, when the suspended load is lifted and separated from the ground or the floor, switch to a low-speed lift speed at which no impact occurs and lift, and then, at the lift-off position (the position where lift-off is assumed), switch to a high-speed lift speed and lift.

[0004] Also, the electric cargo handling device described in Patent Document 2 calculates a deceleration position from the load detection information of the load / no-load detection sensor in order to lower and land the cargo. When operating the lowering switch to lower the suspended load, first lower at a high-speed lowering speed, switch to a low-speed lowering speed at the deceleration position, and after the suspended load lands, lower again at a high-speed lowering speed.

[0005] The electric cargo handling device described in Patent Document 2 aims to reduce the impact applied to the cargo at the time of lifting and landing by performing such lifting and lowering control of the suspended load, whether the operator is a beginner or an expert. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2005-212979 [Patent Document 2] Japanese Patent Publication No. 2008-239258 [Overview of the project] [Problems that the invention aims to solve]

[0007] In the electric cargo handling device described in Patent Document 1 above, the vertical position can be stored in the work position memory unit by operating the work position memory switch, and then the vertical position can be played back and positioned by operating the position playback switch to the taught and stored position.

[0008] Generally, with electric cargo handling equipment, when lifting the cargo off the ground or lowering it to the ground during a lowering operation, it is necessary to operate the lifting and lowering at a low speed to avoid impacting the suspended load.

[0009] If only the working position is taught and memorized, as in the electric cargo handling device described in Patent Document 1, and the cargo is raised and lowered at the same lifting speed using a position playback function, there is a risk of subjecting the cargo to a large impact during the ground cutting and landing operations.

[0010] When using the electric cargo handling device described in Patent Document 2 to transport a suspended load using a sling belt (or sling chain, etc.), the weight of the sling belt is detected by the load presence detection means, and the deceleration of the lifting operation is controlled accordingly. Therefore, if the length of the sling belt changes, the time required for lifting from the ground will change, and changing the sling belt or the suspended load will cause the lifting position to shift. For this reason, it is considered that the control method of the electric cargo handling device described in Patent Document 2 cannot realize a function to play back the working position.

[0011] Furthermore, the electric cargo handling device described in Patent Document 2 allows operators to operate the device at a lifting speed that matches their skill level, regardless of whether they are beginners or experienced, by having them wear ID tags and reading them with an ID tag reader. However, this requires each operator to wear an ID tag, which is cumbersome for the operators.

[0012] Therefore, the present invention has been made in view of the above problems, and aims to provide an electric cargo handling device that can perform smooth and rapid transport operations without shocking the cargo during ground clearance, regardless of the operator's skill level. [Means for solving the problem]

[0013] To solve the above problems, the present invention provides: An electric cargo handling device having an electric cargo handling device body and operating means for operating the cargo handling device body, The cargo handling device body comprises a lifting mechanism for suspending cargo from a suspension member and raising and lowering it vertically, an electric motor for driving the lifting mechanism, a storage unit for storing the target position for raising and lowering the suspension member as cargo handling operation teaching data, a control unit, and a detection unit for detecting that a load of cargo is applied to the suspension member. The operating means includes a work memory switch for inputting an instruction to store the target position in the memory unit, and at least one playback switch for inputting an instruction to raise or lower the suspension member to the target position stored in the memory unit. By operating the work memory switch, the first target position for raising the suspension member can be stored in the memory unit as cargo handling operation teaching data. Upon operation of the playback switch, the control unit executes a first cargo handling operation playback function, in which the suspension member rises at a low speed from the time the suspension member begins to rise until the cargo is lifted off the ground, and after the cargo is lifted off the ground, the suspension member rises at a high speed toward the first target position. The present invention provides an electric cargo handling device characterized in that, when the first cargo handling operation playback function is executed, the control unit determines, based on the detection result of the detection unit, that when no load of the cargo is applied to the suspension member, it is from the time the suspension member starts to rise in the first cargo handling operation playback function until the cargo is lifted off the ground, and that when a load of the cargo is applied to the suspension member, it is after the cargo is lifted off the ground in the first cargo handling operation playback function. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide an electric cargo handling device that can perform smooth and rapid transport operations without causing impact to the cargo during ground clearance, regardless of the operator's skill level. [Brief explanation of the drawing]

[0015] [Figure 1] Figure 1 is a control system diagram showing the configuration of an electric hoist according to an embodiment of the present invention. [Figure 2] Figure 2 is an explanatory diagram of the operation of the cargo handling operation playback function when lifting and raising cargo on an electric hoist. [Figure 3] Figure 3 is an explanatory diagram of the operation of the cargo handling operation playback function during the lowering and landing of cargo on an electric hoist. [Figure 4] Figure 4 shows the relationship between the time and the lifting speed during the cargo handling operation playback function when lifting and raising cargo with an electric hoist. [Figure 5] Figure 5 shows the relationship between the time and the lifting speed during the cargo handling operation playback function when lowering and landing cargo on an electric hoist. [Figure 6] Figure 6 is a control flow diagram of the cargo handling operation playback function when lifting and raising cargo using an electric hoist. [Figure 7] Figure 7 is a control flow chart of the cargo handling operation playback function during the lowering and landing of cargo on an electric hoist. [Figure 8] Figure 8 is an explanatory diagram illustrating the operation of an electric hoist when it continuously performs multiple cargo handling operation playback functions. [Figure 9] FIG. 9 is an example of setting of load handling work storage data when the playback function is executed based on one load handling work teaching data with one load handling work playback switch of the electric hoist. [Figure 10] FIG. 10 is an example of setting of load handling work storage data when the playback function is continuously executed with two load handling work teaching data using one load handling work playback switch of the electric hoist.

Mode for Carrying Out the Invention

[0016] An embodiment of the present invention will be described for an electric hoist. Note that this is an example of the present invention, and the present invention can be applied to all electric load handling devices having a lifting mechanism by an electric motor such as an electric chain block, an electric winch, a multi-joint arm-type load handling device, and the like.

[0017] FIG. 1 is a configuration diagram of a control system of an electric hoist according to the present embodiment. As shown in FIG. 1, the electric hoist 100 according to the present embodiment includes an electric hoist main body 1 and an operation pendant 17 for operating the electric hoist main body 1.

[0018] In the electric hoist main body 1, the AC voltage supplied from the single-phase / three-phase AC power supply 2 is converted into a DC voltage by an AC (Alternating Current) / DC (Direct Current) converter circuit 3. This DC voltage is smoothed by a smoothing circuit 4 and supplied as a power source to an inverter-type motor drive circuit 5. The motor drive circuit 5 converts the DC voltage output from the AC / DC converter circuit 3 into an AC voltage (AC current) for driving the motor 7 at a predetermined rotational speed based on the motor drive signal from the speed / torque control unit 16 and supplies it to the motor 7.

[0019] A reduction gear mechanism 8 is directly connected to the electric motor 7, and is configured to convert the output of the electric motor 7 from high-speed rotation to low-speed rotation so that high torque can be output. A wire drum 9 is connected to the output shaft. A wire rope 21 is wound around the wire drum 9, and a hook 22 attached to the lower end of the wire rope 21 can be used to raise and lower the lifted cargo 24.

[0020] The operating pendant 17 is equipped with a lifting switch (not shown) for raising and lowering the hook 22, as well as a work position memory switch 18, a cargo handling operation playback 1 switch 19, and a cargo handling operation playback 2 switch 20. The cargo handling operation instruction data storage unit 11 of the electric hoist body 1 stores the cargo handling operation instruction data, which is necessary for executing the cargo handling operation playback function, as described later.

[0021] When an operator operates the cargo handling operation playback 1 switch 19 or the cargo handling operation playback 2 switch 20 on the operation pendant 17, the playback position command value issuing unit 13 of the electric hoist body 1 reads the cargo handling operation teaching data stored in the cargo handling operation teaching data storage unit 11, creates a position command value for cargo handling operation playback based on the data, and outputs it to the position control unit 14. The position control unit 14 performs servo position control based on the position command value input from the playback position command value issuing unit 13 and the current position information (vertical position of the hook 22) read from the encoder 10, and creates and outputs a speed command value to the speed / torque control unit 16.

[0022] The speed and torque control unit 16 issues a motor drive command (a command to drive the motor 7) based on the speed command value input from the position control unit 14 and the motor current value detected by the current detection sensor 6, causing the motor 7 to rotate at a predetermined speed. The cargo handling presence / absence detection unit 12 reads the torque value of the electric motor 7 calculated in the speed / torque control unit 16, determines whether the cargo handling object 24 is being lifted, and outputs cargo handling presence / absence information (information on whether the cargo handling object 24 is suspended from the hook 22 (information on whether the cargo handling object 24 is being lifted)) to the playback position command value issuing unit 13 for use in the cargo handling operation playback function.

[0023] Figure 2 is an explanatory diagram illustrating the operation of the cargo handling operation playback function during the lifting phase of the electric hoist 100 according to this embodiment, which is set to lift the cargo 24. The cargo handling playback function refers to a function in which, by operating the cargo handling playback 1 switch 19 or the cargo handling playback 2 switch 20 on the operation pendant 17, the electric hoist body 1 raises and lowers the cargo 24, which is stored in the electric hoist body 1, at a suitable speed corresponding to its vertical position, to the target vertical position of the cargo 24.

[0024] Before performing the lifting operation of the cargo 24 using the cargo handling operation playback function, the worker moves the center position of the hook 22 to position D (see Figure 2), which is the target position for lifting the cargo 24. The worker then operates the work position memory switch 18 to save the information of position D (vertical position information) to the cargo handling operation teaching data storage unit 11. Specifically, the information of position D is stored as the target storage position for teaching operation number 1 in the cargo handling operation teaching data table provided in the cargo handling operation teaching data storage unit 11, which is shown as an example in Figure 9.

[0025] Furthermore, as shown in Figure 9, the operator sets the cargo handling operation PB (playback) switch number (the switch number that executes the cargo handling operation playback function) for teaching operation number 1 to the cargo handling operation playback 1 switch 19. The operation pendant 17 is equipped with, for example, a touch panel (not shown), which the operator uses to input (teach) cargo handling operation teaching data such as the cargo handling operation PB switch number to the electric hoist body 1 and store it in the cargo handling operation teaching data storage unit 11. The cargo handling operation teaching data and Figure 9 will be described in detail later.

[0026] After the above teaching and memory operations are completed, the cargo 24 is suspended at starting position A by the hook 22 via a sling belt or sling chain 23. In this state, when the operator operates the cargo handling operation playback 1 switch 19, the cargo 24 rises at a low speed from starting position A to position B, and after the presence or absence of cargo is detected by the cargo presence detection means, it accelerates and rises at a high speed from position B to position C, and then decelerates from position C to target memory position D, stopping when it reaches the stored target memory position D. By performing the lifting and raising operation of the cargo 24 using the cargo handling operation playback function in this way, the impact on the cargo 24 caused by the ground clearance is mitigated, and the cargo 24 can be smoothly lifted to the upper target memory position D.

[0027] Figure 4 is a diagram showing the relationship between the operating time and the lifting speed of the lifting operation playback function during the ascent, which teaches and stores the lifting operation of the cargo 24, in the electric hoist 100 according to this embodiment. Figure 4 shows that after acceleration control is performed to reach a set low-speed ascent rate, the vehicle ascends at a constant low speed, and then, after the presence or absence of cargo is detected by the cargo presence detection means, acceleration control is performed to ascend at a set high speed, and the vehicle decelerates and stops at the target position D.

[0028] By performing playback control of cargo handling operations in this manner, the impact when lifting the cargo 24 from the ground when the cargo 24 is not detected is mitigated, and the cargo 24 can be lifted smoothly after being raised. Furthermore, cargo handling operations using the aforementioned playback function have the advantage that cargo handling operations can be performed stably in the same way regardless of which operator is performing the operation, without relying on the operator's skill.

[0029] Figure 6 is a control flow diagram of the cargo handling operation playback function processing during the lifting operation of the cargo handling work 24 of the electric hoist 100 according to this embodiment. Here, the electric hoist body 1 is equipped with a storage unit (not shown) that stores a program for realizing the cargo handling operation playback function during ascent as shown in Figure 6 and a program for realizing the cargo handling operation playback function during descent as shown in Figure 7, which will be described later, and a central control unit (not shown) that controls each part of the electric hoist body 1 and executes the two programs stored in the storage unit.

[0030] The program that enables the cargo handling operation playback function during the ascent, as shown in Figure 6, is started when the power switch (not shown) on the electric hoist body 1 is turned on. The central control unit checks whether the cargo handling operation playback 1 switch 19 is ON or OFF (step ST10). If the switch 19 is OFF, it performs a deceleration stop process (step ST12) and returns to step ST10. If the switch 19 is ON, it reads the current position Pn of the hook 22 from the encoder 10 (step ST11).

[0031] In step ST11, the central control unit causes the playback position command value issuing unit 13 to read the cargo handling operation teaching data (see teaching operation number item 1 in Figure 9) stored in the cargo handling operation teaching data storage unit 11, and based on this data, causes the position control unit 14 to output a position command value (target stored position D) for cargo handling operation playback. The position control unit 14 then performs servo position control using the position command value and the current position Pn of the hook 22, and outputs a speed command value (teaching speed Vl (low speed), teaching speed Vh (high speed), acceleration + Al for acceleration, acceleration + Ah for acceleration, acceleration - Ah for deceleration) to the speed / torque control unit 16.

[0032] The central control unit calculates the current velocity Vn of the rising hook 22 from the difference between the current position Pn of the hook 22 and the previously detected current position using the differential processing unit 15 (step ST13). Next, the central control unit checks the presence or absence of the cargo handling object 24 using the cargo handling object presence / absence detection unit 12 (step ST14).

[0033] If the cargo handling object detection unit 12 does not detect the cargo handling object 24, the central control unit checks whether the current speed Vn has reached the taught speed Vl (low speed) (step ST15). If the current speed Vn has not reached the taught speed Vl, the central control unit uses the speed / torque control unit 16 to perform an upward acceleration process with upward acceleration +Al (step ST16), and returns to step ST10. If the current speed Vn has reached the taught speed Vl (low speed), it returns to step ST10 as is.

[0034] In step ST14, if the presence or absence detection unit 12 detects the presence or absence of cargo 24, the central control unit checks whether the current position Pn has reached the upper position (deceleration position) C (step ST17). If the deceleration position C has not been reached, the central control unit checks whether the current speed Vn has reached the taught speed Vh (high speed) (step ST18).

[0035] If the current speed Vn has not reached the taught speed Vh, the central control unit, via the speed / torque control unit 16, performs acceleration control in the upward direction with an upward acceleration of +Ah (step ST19), and returns to step ST10. If the current speed Vn has reached the taught speed Vh, the process returns to step ST10 as is.

[0036] In step ST17, if the current position Pn has reached the deceleration position C, the central control unit checks whether the current position Pn has reached position (target position) D (step ST20). If the current position Pn has reached position D, the central control unit executes an immediate stop process for the upward movement (step ST22) and terminates this process. If the current position Pn has not reached position D, the central control unit uses the speed / torque control unit 16 to perform deceleration control of the upward speed with acceleration -Ah (however, upward speed Vn > 0) (step ST21) and returns to step ST10. The control flow described above enables the playback function of cargo handling operations when the cargo 24 of the electric hoist 100 is raised according to this embodiment.

[0037] Figure 9 shows an example of setting the cargo handling operation teaching data when an operator operates the cargo handling operation playback function by operating the cargo handling operation playback 1 switch 19 and the cargo handling operation playback 2 switch 20. In Figure 9, the setting data for teaching operation number item 1 is the cargo handling operation teaching data for the cargo handling operation playback function during cargo lifting and hoisting, as described above. In this cargo handling operation teaching data, the cargo handling operation PB switch number field is set to "Playback 1 switch 19", the target memory position field is set to "Position D", the low-to-high speed switching control field when lifting and cargo detection is set to "Yes", and the movement speed is set to 20% (low speed) in the first movement speed field and 100% (high speed) in the second movement speed field. Although not shown in Figure 9, a deceleration position C is set a predetermined amount below position D in conjunction with the setting of the target memory position D (see Figure 2).

[0038] The cargo handling operation teaching data for teaching operation number 1 in Figure 9 indicates that when no cargo 24 is detected at startup, the system starts the upward movement at 20% (low speed), and when the cargo presence / absence detection unit 12 detects the presence of cargo 24, it switches to an upward movement speed of 100% (high speed), and stops when it reaches the target memory position D. Although not shown in this cargo handling operation teaching data, acceleration and deceleration times are set separately during speed switching and startup / stopping, i.e., sections for acceleration and deceleration are provided (see Figure 2), and acceleration and deceleration control is performed. As described above, by having the operator pre-program the cargo handling operation teaching data for the cargo handling operation playback function and storing it in the cargo handling operation teaching data storage unit 11, the electric hoist 100 according to this embodiment can execute the cargo handling operation playback function.

[0039] Furthermore, the cargo handling operation instruction data may be configured such that the operator only sets the target memory position D by operating the work position memory switch 18, and other information such as the cargo handling operation PB switch number and movement speed is automatically set by the central control unit, or the operator may set at least one of the other pieces of information themselves by operating the touch panel. The same applies to the cargo handling operation instruction data for the cargo handling operation playback function during descent and landing operations, which will be described later.

[0040] Figure 3 is an explanatory diagram illustrating the operation of the cargo handling operation playback function of the electric hoist 100 according to this embodiment during the lowering and landing of the cargo 24. Before executing the cargo handling operation playback function, the operator must teach the vertical position of the hook 22 as shown below and store it as cargo handling operation teaching data in the cargo handling operation teaching data storage unit 11.

[0041] (1) Target position (landing position) H: The operator operates the lifting switch (not shown) and the work position memory switch 18 of the operation pendant 17 to teach and store the landing position H in the cargo handling operation teaching data storage unit 11. (2) Low-speed operating range from landing position H to position F above it: The operator directly inputs numerical values ​​by operating the touch panel (not shown) of the operation pendant 17.

[0042] The cargo handling operation teaching data for the cargo handling operation playback function during the lowering and landing operation of the cargo handling object 24 is shown in teaching operation number 2 in Figure 9. In the cargo handling operation teaching data for teaching operation position number 2, the operator operates the touch panel of the operation pendant 17 to set the cargo handling operation PB switch number field to "Playback 2 switch 20", the first movement speed field to 100% (high speed) and the second movement speed field to 20% (low speed). In addition, in the cargo handling operation teaching data, the high-speed→low-speed switching control field above the landing position is set to "Yes", and the upper second movement speed operation range (range from target position H to low-speed operation start position F) field is set to "40cm". Although not shown in Figure 9, a deceleration position E is set a predetermined amount above position F in accordance with the setting of the low-speed operation start position F (see Figure 3).

[0043] In Figure 3, when the cargo handling object 24 is suspended in the air and stopped, if the operator operates the cargo handling operation playback 2 switch 20, the cargo handling object will descend at high speed from position (starting position) D to position (low-speed operation start position) F, then descend at low speed from position F to landing position (target position) H, and stop when it reaches landing position H. Similar to the lifting of the cargo handling object 24 shown in Figure 2, acceleration and deceleration times are set separately during speed changes and during starting and stopping, i.e., sections for acceleration and deceleration are provided (see Figure 3), and acceleration and deceleration control is performed.

[0044] As described above, the electric hoist 100 according to this embodiment controls lowering and landing using the cargo handling operation playback function, which eliminates the impact on the cargo 24 during landing and stopping, regardless of the type of cargo 24, and allows for smooth transport to the landing position H after landing. Furthermore, if the cargo 24 is to be moved to a different landing position that is in a different vertical position from the landing position H, this can be easily handled by teaching and storing only that different landing position in the cargo handling operation teaching data storage unit 11 again.

[0045] Figure 5 is a diagram illustrating the relationship between the time and the lifting speed during the lowering and landing of the cargo 24 of the electric hoist 100 according to this embodiment. Figure 5 shows that the cargo 24 descends from position D while accelerating to a pre-programmed high-speed descent speed, then descends further at the high-speed descent speed to the deceleration position E, performs a deceleration operation, descends at a low speed from the low-speed operation start position F to the deceleration position G, and then descends further at a deceleration speed to the landing position H and stops.

[0046] Figure 7 is a control flow diagram of the cargo handling operation playback function of the electric hoist 100 according to this embodiment during the lowering and landing of the cargo 24. The program that enables the playback function of cargo handling operations during descent, as shown in Figure 7, is started when the power switch (not shown) on the electric hoist body 1 is turned on.

[0047] The central control unit checks whether the cargo handling operation playback 2 switch 20 is ON or OFF (step ST30). If the switch 20 is OFF, it performs a deceleration stop process (step ST32) and returns to step ST30. If the switch 20 is ON, it reads the current position Pn of the hook 22 from the encoder 10 (step ST31).

[0048] In step ST31, the central control unit causes the playback position command value issuing unit 13 to read the cargo handling operation teaching data (see teaching operation number item 2 in Figure 9) stored in the cargo handling operation teaching data storage unit 11, and based on this data, causes the position control unit 14 to output a position command value (target stored position H) for cargo handling operation playback. The position control unit 14 then performs servo position control using the position command value and the current position Pn of the hook 22, and outputs a speed command value (teaching speed Vh (high speed), teaching speed Vl (low speed), acceleration -Ah for acceleration, deceleration +Ah for acceleration, deceleration +Al for acceleration) to the speed / torque control unit 16.

[0049] The central control unit calculates the current downward velocity Vn of the hook 22 from the difference between the current position Pn of the hook 22 and the previous current position detected in the previous step (step ST33). Next, the central control unit checks whether the current position Pn of the hook 22 is above the position (deceleration position) E (step ST34).

[0050] If the current position Pn of the hook 22 has not descended to position E, the central control unit checks whether the current velocity Vn has reached the taught velocity Vh (high velocity) (step ST35). If the current velocity Vn has reached the taught velocity Vh, the process returns to step ST30. If the current velocity Vn has not decelerated to the taught velocity Vh, the central control unit uses the velocity / torque control unit 16 to perform acceleration control in the downward direction with a downward acceleration of -Vh (step ST36), and the process returns to step ST30.

[0051] In step ST34, if the current position Pn of the hook 22 is less than or equal to position E, it is checked whether the current position Pn of the hook 22 is above position G (the starting position for deceleration operation) (step ST37).

[0052] If the current position Pn of hook 22 has not descended to position G, the system checks whether the current velocity Vn has decelerated to the taught velocity Vl (low velocity) (step ST38). If the current velocity Vn has decelerated to the taught velocity Vl, the system returns to step ST30. If the current velocity Vn has not decelerated to the taught velocity Vl (low velocity), the central control unit performs deceleration by adding upward acceleration +Ah via the velocity / torque control unit 16 (step ST39), and then returns to step ST30.

[0053] In step ST37, if the current position Pn of the hook 22 is less than or equal to position G, the central control unit checks whether the current position Pn of the hook 22 has reached the target position H (step ST40). If the current position Pn of the hook 22 has not reached the target position H, the central control unit uses the speed / torque control unit 16 to decelerate the descent speed by acceleration + Al (however, the descent speed Vn < 0) (step ST41), and returns to step ST30. If the current position Pn of the hook 22 has reached the target position H, the central control unit executes a process to immediately stop the descent movement (step ST42), and terminates this process. The control flow described above enables the playback function of the cargo handling operation when the cargo 24 of the electric hoist 100 is lowered according to this embodiment.

[0054] As described above, the electric hoist 100 according to this embodiment is configured to execute the cargo handling operation playback function during ascent on the cargo handling operation playback 1 switch 19 and the cargo handling operation playback function during descent on the cargo handling operation playback 2 switch 20, respectively, meaning that a total of two switches are used. However, it is not limited to this configuration, and as described below, the electric hoist 100 according to this embodiment can also be configured to execute multiple cargo handling operation playback functions in succession using a single switch, for example, the cargo handling operation playback function during ascent → the cargo handling operation playback function during descent.

[0055] Figure 8 is an explanatory diagram of the operation of the electric hoist 100 according to this embodiment when the cargo handling operation playback function is executed continuously. Specifically, Figure 8 shows the operation of the electric hoist 100 when the cargo handling operation playback function processing when the cargo handling object 24 is raised as shown in Figure 2 and the cargo handling operation playback function when the cargo handling object 24 is lowered as shown in Figure 3 are executed continuously. The cargo handling operation teaching data in this case is shown in Figure 10.

[0056] As shown in Figure 10, the cargo handling operation playback switch number "Playback 1 Switch 19" is set only for teaching operation number item 1. Furthermore, by setting "2" in the linked teaching operation number field of teaching operation number item 1, the system is configured to execute the cargo handling operation playback function processing for teaching operation number item 2 immediately after the execution processing of the cargo handling operation playback function for teaching operation number item 1 is completed. Note that the other fields for teaching operation number items 1 and 2 are set in the same way as in Figure 9.

[0057] The operation of the electric hoist 100 according to this embodiment, based on the cargo handling operation teaching data in Figure 10, will be explained with reference to Figure 8. When the operator operates the cargo handling operation playback 1 switch 19, the cargo handling operation playback function similar to that in Figure 2 is executed based on the cargo handling teaching operation data of teaching operation number item 1. Specifically, the electric hoist 100 lifts the cargo 24 and raises the hook 22 to position D (a pre-taught target memory position). As a result, the cargo 24 is lifted to a position above the height of the obstacle 25.

[0058] At this time, the worker moves the electric hoist 100 horizontally to above the cargo storage box 26 installed for storing the cargo 24. Then, the electric hoist 100 executes the cargo handling operation playback function similar to that in Figure 3 based on the cargo handling teaching operation data of teaching operation number item 2, and the cargo 24 is stored in the cargo storage box 26.

[0059] As described above, the electric hoist 100 according to this embodiment can perform multiple cargo handling operations in succession with a single cargo handling operation playback switch 19 by continuously using the cargo handling operation playback function. Therefore, the electric hoist 100 can perform even complex cargo handling operations smoothly and quickly, and can perform cargo handling operations without relying on the operator's skills. Accordingly, even operators unfamiliar with transport operations can perform cargo handling operations smoothly and quickly, just like experienced operators, by using the cargo handling operation playback function of the electric hoist 100.

[0060] As described above, according to the electric hoist 100 of this embodiment, in addition to target position information, one or more pieces of cargo handling operation teaching data such as operating speed and working conditions are stored in advance in the cargo handling operation teaching data storage unit 11. By operating the cargo handling operation playback 1 switch 19 and the cargo handling operation playback 2 switch 20, the cargo handling operation playback function is executed based on the cargo handling operation teaching data stored in the cargo handling operation teaching data storage unit 11, thereby enabling cargo handling operations to be performed quickly and smoothly, and effectively mitigating the impact on the cargo 24 that occurs when the cargo 24 is lifted or when the cargo 24 is lowered.

[0061] In the electric hoist 100, if multiple, for example, three, cargo handling operation instruction data are stored in association with the cargo handling operation instruction data storage unit 11, the cargo handling operation playback function can first be executed based on the first cargo handling operation instruction data to move the cargo 24 to the first target position, then the cargo handling operation playback function can be executed based on the second cargo handling operation instruction data to move the cargo 24 to the second target position, and finally the cargo handling operation playback function can be executed based on the third cargo handling operation instruction data to move the cargo 24 to the third target position. By executing multiple cargo handling operation playback functions in succession in this way, complex cargo handling operations can be performed quickly and smoothly.

[0062] The cargo handling operation playback function of the Electric Hoist 100 ensures that cargo handling operations can be performed stably and consistently, regardless of whether the operator is a beginner or an experienced worker, as it does not rely on the operator's skill level. [Explanation of symbols]

[0063] 1. Electric hoist unit 2 Single-phase / Three-phase AC power supply 3. AC / DC Converter Circuit 4 Smoothing circuit 5. Inverter-type motor drive circuit 6 Current Sensor 7 Electric motor 8 Reduction mechanism 9 Wire drum 10 encoders 11. Cargo handling operation instruction data storage unit 12. Cargo handling object presence detection unit 13. Playback position command value issuing unit 14 Position Control Unit 15 Differential Calculus Section 16 Speed ​​and Torque Control Unit 17 Operation Pendant 18. Work position memory switch 19. Cargo handling operation playback 1 switch 20. Cargo handling operation playback 2 switches 21 Wire 22 hooks 23. Sling belt or sling chain 24. Cargo handling equipment 25 Obstacles 26. Cargo handling storage box 100 Electric Hoist

Claims

1. An electric cargo handling device having an electric cargo handling device body and operating means for operating the cargo handling device body, The cargo handling device body comprises a lifting mechanism for suspending cargo from a suspension member and raising and lowering it vertically, an electric motor for driving the lifting mechanism, a storage unit for storing the target position for raising and lowering the suspension member as cargo handling operation teaching data, a control unit, and a detection unit for detecting that a load of cargo is applied to the suspension member. The operating means includes a work memory switch for inputting an instruction to store the target position in the memory unit, and at least one playback switch for inputting an instruction to raise or lower the suspension member to the target position stored in the memory unit. By operating the work memory switch, the first target position for raising the suspension member can be stored in the memory unit as cargo handling operation teaching data. Upon operation of the playback switch, the control unit executes a first cargo handling operation playback function, in which the suspension member rises at a low speed from the time the suspension member begins to rise until the cargo is lifted off the ground, and after the cargo is lifted off the ground, the suspension member rises at a high speed toward the first target position. An electric cargo handling device characterized in that, when the first cargo handling operation playback function is executed, the control unit determines, based on the detection result of the detection unit, that when no load of the cargo is applied to the suspension member, it is from the time the suspension member starts to rise in the first cargo handling operation playback function until the cargo is lifted off the ground, and that when a load of the cargo is applied to the suspension member, it is after the cargo has been lifted off the ground in the first cargo handling operation playback function.

2. The deceleration start position below the first target position can be stored in the storage unit as cargo handling operation teaching data. The electric cargo handling device according to claim 1, characterized in that when the first cargo handling operation playback function is executed, the control unit reduces the upward speed of the suspension member from the deceleration start position to the first target position.

3. By operating the work memory switch, the second target position for lowering the suspension member can be stored in the memory unit as cargo handling operation teaching data. Upon operation of the playback switch, the control unit executes a second cargo handling operation playback function, in which the suspension member descends at high speed from the moment it begins to descend to a predetermined position, and then descends at low speed from the predetermined position toward the second target position. The electric cargo handling device according to claim 1, characterized in that the operating means includes an input unit for inputting an instruction to store in the storage unit a predetermined position above the second target position as cargo handling operation teaching data.

4. The cargo handling operation teaching data of the first cargo handling operation playback function and the cargo handling operation teaching data of the second cargo handling operation playback function can be associated and stored in the storage unit. The electric cargo handling device according to claim 3, characterized in that, upon operation of the playback switch, the control unit executes the first cargo handling operation playback function and the second cargo handling operation playback function in succession.

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