Container loading and unloading vehicle

Abstract

To secure workability while suppressing power consumption.SOLUTION: A container loading and unloading vehicle for loading and unloading a container to / from a chassis includes an electric motor, a hydraulic pump driven by the electric motor, a cargo-handling device for changing its attitude by being driven by hydraulic oil discharged from the hydraulic pump, a sensor for detecting the attitude of the cargo-handling device, an operation device, and a control device for controlling the cargo-handling device in response to an operation signal from the operation device, wherein the control device determines whether or not the current attitude of the cargo-handling device is a predetermined attitude on the basis of output of the sensor, continues driving of the electric motor for a predetermined time from operation interruption of the operation device, when the current attitude of the cargo-handling device is the predetermined attitude, and stops the electric motor in response to the operation interruption of the operation device, when the current attitude of the cargo-handling device is other than the predetermined attitude.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a container loading / unloading vehicle equipped with a loading / unloading device for loading / unloading containers onto / from a vehicle chassis. [Background technology]

[0002] Among the mounted objects attached to work vehicles, there are electrically driven ones, which are driven, for example, by oil discharged from a hydraulic pump driven by an electric motor (Patent Document 1, etc.). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-47710 Summary of the Invention [Problem to be solved by the invention]

[0004] While an electric mounted device is in use, specifically while the device's power is on, if the electric motor and hydraulic pump are driven even when the operating device is not being operated, hydraulic oil is quickly supplied to the hydraulic actuator when the device is operated, allowing the mounted device to operate responsively. However, driving the electric motor even when the mounted device is not moving leads to waste of remaining battery power. In particular, if the battery is shared between the electric motor for driving the vehicle and the electric motor for the mounted device, as in Patent Document 1, the vehicle's cruising range will be shortened.

[0005] On the other hand, if the electric motor of the mounted equipment is stopped when the operating device is not being operated, waste of remaining battery power can be reduced. However, in this case, the electric motor stops every time operation is interrupted and starts every time operation is resumed. In other words, the stopped electric motor starts when operation is resumed, and hydraulic oil begins to be supplied from the hydraulic pump after the electric motor starts, which makes it easy for a response delay to occur between operation and the movement of the mounted equipment, reducing operability.

[0006] Such a response delay is undesirable for a container loading / unloading vehicle. In the case of a container loading / unloading vehicle, in addition to a dumping operation in which the container is tilted up and its contents are discharged, the vehicle also performs a container loading / unloading operation in which the container is loaded onto or unloaded from the vehicle chassis. During the container loading / unloading operation, when the arm of the mounted device is hooked onto the round bar of the container, it is common to perform an inching operation to fine-tune the angle of the arm in order to align the position of the hook with the round bar. Furthermore, after the arm is hooked onto the container, an inching operation is also performed when the container's main girder is received by the guide rollers in the process of lifting the container onto the vehicle chassis. If there is a large time lag between the operation of the operating device and the movement of the arm, it becomes difficult to perform fine adjustments to the arm angle, resulting in poor workability during the container loading / unloading operation.

[0007] An object of the present invention is to provide a container loading / unloading vehicle that can ensure workability while reducing power consumption. [Means for solving the problem]

[0008] In order to achieve the above object, the present invention provides a container loading / unloading vehicle that loads and unloads containers onto a vehicle chassis, comprising: an electric motor; a hydraulic pump driven by the electric motor; loading and unloading equipment whose posture is changed by being driven by hydraulic oil discharged from the hydraulic pump; a sensor that detects the posture of the loading and unloading equipment; an operating device; and a control device that controls the loading and unloading equipment in response to an operating signal from the operating device, wherein the control device determines based on the output of the sensor whether the current posture of the loading and unloading equipment is a predetermined posture, and if the current posture of the loading and unloading equipment is the predetermined posture, continues to drive the electric motor for a predetermined time after operation of the operating device is interrupted, and if the current posture of the loading and unloading equipment is other than the predetermined posture, stops the electric motor in response to the interruption of operation of the operating device. [Effects of the Invention]

[0009] According to the present invention, it is possible to ensure workability while suppressing power consumption. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a side view showing a container mounting and dismounting vehicle according to a first embodiment of the present invention. [Figure 2] 1 is a plan view showing a container mounting and dismounting vehicle according to a first embodiment of the present invention. [Figure 3] FIG. 1 is a rear view showing a container detachable vehicle according to a first embodiment of the present invention. [Figure 4] 1 is a schematic diagram of a drive system provided in a container loading / unloading vehicle according to a first embodiment of the present invention. [Figure 5] 1 is a schematic diagram of an operating device provided on a container loading / unloading vehicle according to a first embodiment of the present invention. [Figure 6] 3 is a schematic diagram showing a container loading operation of the container detachable vehicle according to the first embodiment of the present invention. FIG. [Figure 7] 3 is a schematic diagram showing a container loading operation of the container detachable vehicle according to the first embodiment of the present invention. FIG. [Figure 8] 3 is a schematic diagram showing a container loading operation of the container detachable vehicle according to the first embodiment of the present invention. FIG. [Figure 9] 4 is a flowchart showing a procedure for controlling the rotation speed of an electric motor by a control device provided in the container loading / unloading vehicle according to the first embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0012] -Container detaching vehicle- Fig. 1 is a side view of a container detachable vehicle according to a first embodiment of the present invention, Fig. 2 is a plan view thereof, and Fig. 3 is a rear view thereof. In the following description of the embodiment, the left and right in Fig. 1 will be referred to as the front and rear of the container detachable vehicle, respectively.

[0013] The container loading / unloading vehicle 100 shown in FIGS. 1 to 3 includes a chassis 110, a loading device 120, guide rollers 130, etc. The chassis 110 includes a chassis frame 111 connected to the rear side of the driver's cab and a subframe 112 supported by the chassis frame 111. The subframe 112 may be omitted. The loading device 120 loads and unloads containers C onto and from the chassis 110 by sliding and pivoting an L-shaped arm 121 back and forth. The loading device 120 is supported on the chassis 110, or in this embodiment, on the subframe 112. A pair of left and right guide rollers 130 are provided on the chassis 110, or in this embodiment, at the rear end of the subframe 112, and guide the main girders Cg of the containers C being loaded onto and unloaded from the container loading / unloading vehicle 100.

[0014] The container C loaded onto the container detachable vehicle 100 is a box-shaped container with an open top. Although not shown, the rear of the container C is configured with an openable rear gate. The rear gate is a downward-opening type, and the lower part rotates via a hinge at the top to open and close the rear opening of the container C. A pair of left and right main girders Cg extending in the fore-and-aft direction are provided at the bottom of the container C and protrude downward. The left and right main girders Cg are rod-shaped members extending parallel to each other in the fore-and-aft direction. The main girders Cg extend the entire length of the container C. These main girders Cg are legs that also serve as reinforcements for the container C, and are supported by guide rollers 130 of the container detachable vehicle 100. The left and right spacing between the left and right main girders Cg is set to match the left and right spacing between the guide rollers 130. The container C is a container for a detachable vehicle designed to be loaded onto the container detachable vehicle 100, and although not shown, the bottom of the container C is provided with left and right engaging members that engage with the container fastening devices 140 provided on the container detachable vehicle 100. A handle-shaped round bar Cb is provided on the upper front of the container C to hook the hook 125 of the arm 121.

[0015] The loading / unloading device 120 is a mechanism for lifting a container C onto the vehicle chassis 110 and lowering it from the vehicle chassis 110. The arm 121 of the loading / unloading device 120 is configured to include a dump arm 122, a loading / unloading arm 123, etc. The dump arm 122 is an arm that stands up when the container C is tilted up on the vehicle chassis 110 to perform a dumping operation for dumping and unloading the cargo of the loaded container C. The dump arm 122 is disposed at the rear of the subframe 112 and is rotatably connected to the rear of the subframe 112 via a shaft 124 that extends in the left-right direction (vehicle width direction). The front-to-rear length of the dump arm 122 is shorter than the front-to-rear length of the subframe 112. The loading / unloading arm 123 is an arm used for loading and unloading the container C, and is rotatably connected to the front (tip) of the dump arm 122, and rotates back and forth on the vehicle chassis 110.

[0016] The loading / unloading arm 123 includes a base arm 123a connected to the subframe 112 and a hook arm 123b connected to the tip of the base frame. The hook arm 123b is formed in an L-shape with a horizontal portion that extends horizontally in the front-to-rear direction and an upright portion that rises up and down when the container loading / unloading vehicle 100 is in a traveling position, and the horizontal portion is slidably inserted into the base arm 123a. A hook 125 that is hooked onto the round bar Cb of the container C is provided at the tip (upper end) of the upright portion of the hook arm 123b. Although not shown, the upper portion of the upright portion of the hook arm 123b is formed so as to be rotatable back and forth relative to the lower portion by a hydraulic cylinder (not shown), and the height and fore-and-aft position of the hook 125 may be configured to be changeable along this rotation path.

[0017] In this embodiment, the hook arm 123b slides relative to the base arm 123a, but the hook arm 123b may rotate instead of sliding relative to the base arm 123a. Also, the loading / unloading arm 123 may be configured as an integrated L-shaped arm without being divided into the base arm 123a and the hook arm 123b.

[0018] In the container loading / unloading vehicle 100 of this embodiment, during loading / unloading of the container C, only the loading / unloading arm 123 rotates back and forth while the dump arm 122 remains in a horizontal position. On the other hand, during dumping, the dump arm 122 rotates integrally with the loading / unloading arm 123. To enable this movement, a dump lock device (not shown) is provided that locks and unlocks the rotation of the loading / unloading arm 123 relative to the dump arm 122. Although not shown, the dump lock device is made up of a lock pin, a lock hook that can be engaged with and disengaged from the lock pin, and the like. The lock pin is provided at the tip of the dump arm 122, and the lock hooks are rotatably provided on both side surfaces of the base arm 123a of the loading / unloading arm 123.

[0019] The locking hook engages and disengages with the locking pin by utilizing the sliding movement of the hook arm 123b relative to the base arm 123a. For example, the locking hook is subjected to a force from a spring or the like in the direction in which it engages with the locking pin. When the hook arm 123b slides near the rear end due to the contraction of the slide cylinder 128 (Fig. 4), the hook arm 123b pushes the operating rod, causing the locking hook to disengage from the lock pin. As a result, when the hook arm 123b retreats near the rear end, the rotation mechanism of the loading / unloading arm 123 relative to the dump arm 122 is unlocked, and the extension and contraction of the lift cylinder 127 that drives the arm 121 allows the loading / unloading arm 123 to rotate back and forth relative to the dump arm 122. Conversely, when the hook arm 123b moves forward due to the extension of the slide cylinder 128, the rotation mechanism of the loading / unloading arm 123 relative to the dump arm 122 is locked. In this state, when the lift cylinder 127 extends or retracts, the loading / unloading arm 123 and the dump arm 122 tilt up and down together. The configuration of the dump lock device is described in, for example, Japanese Patent No. 5284541.

[0020] -Drive system- Figure 4 is a schematic diagram of the drive system provided in the container detachable vehicle 100. As shown in the figure, the container detachable vehicle 100 is equipped with a hydraulic circuit 150, a control device 160, and various sensors. The hydraulic circuit 150 drives the lift cylinder 127 and the slide cylinder 128. The lift cylinder 127 is a pair of left and right hydraulic cylinders that rotate the base arm 123a of the arm 121. The slide cylinder 128 is a hydraulic cylinder that is built into the base arm 123a and slides the hook arm 123b relative to the base arm 123a.

[0021] The hydraulic circuit 150 includes an electric motor 151, a hydraulic pump 152, and control valves (directional control valves) 153 and 154. The electric motor 151 is a prime mover for the attached equipment mounted on the container detachable vehicle 100, separate from the electric motor for traveling, and is driven by power supplied from a battery (not shown) mounted on the container detachable vehicle 100. The battery may be shared with the electric motor for traveling, or may be separate from the battery that supplies power to the electric motor for traveling. The hydraulic pump 152 is driven by the electric motor 151 and draws hydraulic oil from a hydraulic oil tank 155, pressurizes it, and discharges it. The hydraulic oil discharged from the hydraulic pump 152 is supplied to the lift cylinder 127 and the slide cylinder 128 via control valves 153 and 154, causing the lift cylinder 127 and the slide cylinder 128 to extend and retract. In this way, the cargo handling device 120 is driven by the hydraulic oil discharged from the hydraulic pump 152 to change its posture.

[0022] The control valves 153, 154 are, for example, center-through electromagnetic pilot-driven three-position switching valves, and are switched and controlled by the control device 160. For example, when the control valve 153 is switched to the switch position on the left side in the figure by a control signal from the control device 160, hydraulic oil discharged from the hydraulic pump 152 is supplied to the bottom-side oil chamber of the lift cylinder 127, causing the lift cylinder 127 to extend. Conversely, when the control valve 153 is switched to the switch position on the right side in the figure by a control signal from the control device 160, hydraulic oil discharged from the hydraulic pump 152 is supplied to the rod-side oil chamber of the lift cylinder 127, causing the lift cylinder 127 to retract. A pilot-operated check valve 156 prevents backflow of hydraulic oil supplied to or discharged from the lift cylinder 127.

[0023] Furthermore, when the control valve 154 is switched to the switching position on the left side in the figure by a control signal from the control device 160, the hydraulic oil discharged from the hydraulic pump 152 is supplied to the bottom-side oil chamber of the slide cylinder 128, causing the slide cylinder 128 to extend. Conversely, when the control valve 154 is switched to the switching position on the right side in the figure by a control signal from the control device 160, the hydraulic oil discharged from the hydraulic pump 152 is supplied to the rod-side oil chamber of the slide cylinder 128, causing the slide cylinder 128 to contract.

[0024] When no control signal is input from the control device 160 and the control valves 153, 154 are in the neutral position due to spring force, even if hydraulic oil is discharged from the hydraulic pump 152, the hydraulic oil passes through the center bypass oil passage of the control valves 153, 154 and returns to the hydraulic oil tank 155.

[0025] The control device 160 controls the cargo handling device 120 in response to an operation signal from the operation device 175. Signals are input to the control device 160 from a slide retraction sensor 171, a lift retraction sensor 172, an inclination sensor 173, a lock sensor 174, the operation device 175, and a thermometer 178. The thermometer 178 is a sensor that measures the temperature of the hydraulic oil in the hydraulic circuit 150, and is provided in, for example, the hydraulic oil tank 155. The slide retraction sensor 171, the lift retraction sensor 172, the inclination sensor 173, and the lock sensor 174 are examples of sensors that detect the posture of the arm 121 of the cargo handling device 120.

[0026] The slide retraction sensor 171 is a sensor that detects whether the loading / unloading arm 123 is at a predetermined position relative to the dump arm 122. This slide retraction sensor 171 can be, for example, a sensor (such as a limit switch) that detects whether the slide cylinder 128 is at a predetermined length (in this embodiment, this is the most retracted state, i.e., a state in which the loading / unloading arm 123 and the dump arm 122 are unlocked). However, in order to detect whether the loading / unloading arm 123 is at a predetermined position relative to the dump arm 122, other sensors such as a stroke sensor that detects the stroke of the slide cylinder 128 may also be used as the slide retraction sensor 171.

[0027] The lift retraction sensor 172 is a sensor that detects whether the loading / unloading arm 123 is at a predetermined angle relative to the chassis 110. This lift retraction sensor 172 can be, for example, a sensor (such as a limit switch) that detects whether the lift cylinder 127 is at a predetermined length (in this embodiment, the most retracted state, i.e., a state in which the loading / unloading arm 123 is at 0 degrees relative to the chassis 110). However, in order to detect whether the loading / unloading arm 123 is at a predetermined angle relative to the chassis 110, other sensors such as an angle meter that detects the angle of the loading / unloading arm 123 relative to the chassis 110 may also be used as the lift retraction sensor 172.

[0028] The inclination sensor 173 is a sensor that detects the inclination angle of the loading / unloading arm 123 relative to the chassis 110. For example, a sensor that detects the inclination angle of the loading / unloading arm 123 relative to the direction of gravity (for example, the inclination angle relative to a horizontal plane) is used as the inclination sensor 173, and is provided, for example, on the loading / unloading arm 123. A similar sensor may be provided on the chassis 110 in addition to the loading / unloading arm 123. In this case, for example, a gyroscope or an IMU (inertial measurement unit) may be used as the inclination sensor 173. Other examples that can be used as the inclination sensor 173 include pendulum-type or float-type inclination sensors (sensors that detect the inclination relative to a hanging weight or liquid surface), acceleration sensors, etc. The inclination sensor 173 detects the angle of the loading / unloading arm 123 relative to the direction of gravity and outputs the detected angle to the control device 160. However, in order to ensure the function of detecting the inclination angle of the loading / unloading arm 123 relative to the chassis 110, an angle sensor that detects the relative angle of the dump arm 122 relative to the chassis 110 or the relative angle of the loading / unloading arm 123 relative to the dump arm 122 can also be used as the inclination sensor 173.

[0029] The lock sensor 174 is a sensor that detects the state in which the container C is fastened by the container fastening device 140. For this lock sensor 174, for example, a limit switch can be used.

[0030] FIG. 5 is a schematic diagram of the operating device 175. The operating device 175 illustrated in FIG. 5 includes a mode selection switch 176 and an operating switch 177. The mode selection switch 176 is an alternate switch having an off position marked "off" when no mode is set, a dumping operation position marked "tilt," a loading / unloading operation position marked "detach." Although a dial switch is illustrated in FIG. 5, other types of switches such as a push button switch may be used. Switching the mode selection switch 176 to the dumping operation position sets the device in dumping operation mode, and switching the mode selection switch 176 to the unloading operation position sets the device in container unloading operation mode. When the mode selection switch 176 is switched to the off position, operations related to dumping and container unloading operations become unavailable. Note that when the mode selection switch 176 is in the off position, the warm-up mode, which will be described later, can be set.

[0031] The operation switch 177 is a momentary switch that commands the loading / unloading operation and dumping operation of the container C. Although a lever switch is shown as an example in FIG. 5, it may be another type of switch such as a push button switch.

[0032] For example, in dump operation mode, the slide cylinder 128 does not operate, and the lift cylinder 127 operates in response to operation. For example, when the operation switch 177 is turned upward (in the direction indicated as "up") in dump operation mode, the lift cylinder 127 extends, and the dump arm 122 and the loading / unloading arm 123 rise together with the shaft 124 as a fulcrum. Thereafter, when the operation switch 177 is turned downward (in the direction indicated as "down"), the lift cylinder 127 contracts, and the dump arm 122 and the loading / unloading arm 123 fall together with the shaft 124 as a fulcrum. The extension and retraction operation of the lift cylinder 127 is performed only while the operation switch 177 is being operated, and the extension and retraction speed changes depending on the amount of operation of the operation switch 177 (amount of tilt).

[0033] Furthermore, in the container unloading operation mode, the slide cylinder 128 and the lift cylinder 127 operate in a predetermined sequence. For example, when the operation switch 177 is turned downward (in the direction indicated as "lower") in the container unloading operation mode, the slide cylinder 128 contracts and the lift cylinder 127 extends in this order, causing the hook arm 123b to slide rearward relative to the base arm 123a, and then the unloading arm 123 pivots rearward relative to the dump arm 122. Thereafter, when the operation switch 177 is turned upward (in the direction indicated as "up") in the container unloading operation mode, the lift cylinder 127 contracts and the slide cylinder 128 extends in this order, causing the unloading arm 123 to pivot forward relative to the dump arm 122, and then the hook arm 123b slides forward relative to the base arm 123a. The extension and contraction operations of the lift cylinder 127 and the slide cylinder 128 are also performed only while the operation switch 177 is being operated, and the extension and contraction speeds of the respective cylinders change according to the operation amount (tilt amount) of the operation switch 177.

[0034] The control device 160 is, for example, a computer equipped with a CPU and memory. The control device 160 outputs command signals to drive the electric motor 151 and control valves 153 and 154 in response to the operation of the operating device 175, and controls the operation of the arm 121 by switching the supply direction of hydraulic oil with the control valves 153 and 154 to extend and retract the lift cylinder 127 and slide cylinder 128. The memory of the control device 160 stores a program related to the operation control of the arm 121 as well as a program related to the drive control of the electric motor 151.

[0035] -Container loading and unloading operation- When loading a container C onto the vehicle chassis 110, the container loading / unloading vehicle 100 is parked at a predetermined position in front of the container C, and first the jack D is lowered, and the mode selection switch 176 of the operating device 175 is switched to the loading / unloading operation position, and the operating switch 177 is turned to the downward side (the "unloading" side) in FIG. 5. In response to the operation of the operating switch 177, an operating signal is input from the operating device 175 to the control device 160. At the start of this operation, the slide retraction sensor 171 is off, the lift retraction sensor 172 is on, and the relative angle of the loading / unloading arm 123 with respect to the vehicle body 110, which is detected based on the output of the inclination sensor 173, is 0. Furthermore, because the container C is not loaded on the vehicle chassis 110, the lock sensor 174 is off.

[0036] In response to an operation signal input from the operating device 175, the control device 160 retracts the slide cylinder 128 and moves the hook arm 123b backward. When the slide cylinder 128 retracts, the lock by the dump lock device described above is released, and the slide retraction sensor 171 turns on. When the slide retraction sensor 171 turns on, the control device 160 switches the driving target from the slide cylinder 128 to the lift cylinder 127, stops the retraction of the slide cylinder 128, and extends the lift cylinder 127. When the lift cylinder 127 extends and the loading / unloading arm 123 begins to swing, the lift retraction sensor 172 turns off. If the operation switch 177 is further operated downward in FIG. 5, the loading / unloading arm 123 rotates rearward as the lift cylinder 127 extends. In this way, the hook 125 of the loading / unloading arm 123, which has been rotated toward the rear of the vehicle, is hooked from below onto the round bar Cb on the front of the container C on the ground, as shown in Figure 6, by fine-tuning the position of the container loading / unloading vehicle 100 and the angle of the loading / unloading arm 123.

[0037] Once the hook 125 is hooked onto the round bar Cb, the operation switch 177 of the operating device 175 is turned upward in FIG. 5 (the "lifting" side). This causes the loading / unloading arm 123 to rotate forward, lifting the front of the container C and pulling it forward, until the main girder Cg of the container C is received by the guide rollers 130, as shown in FIG. 7. The loading / unloading arm 123 then rotates forward further, and the container C is pulled up to the top of the chassis 110 while being guided by the guide rollers 130. When the loading / unloading arm 123 is lowered horizontally and the lift retraction sensor 172 turns on, the control device 160 switches the driving target from the lift cylinder 127 to the slide cylinder 128, stops the retraction of the lift cylinder 127, and extends the slide cylinder 128. When the slide cylinder 128 extends and the loading / unloading arm 123 begins to move forward, the slide retraction sensor 171 turns off, and the dump lock device is locked again. 5, the slide cylinder 128 extends, causing the loading / unloading arm 123 to reach the front end position, completing the loading of the container C onto the chassis 110. In addition, as the loading / unloading arm 123 moves to the front end position, the container C is fastened by the container fastening device 140, and the lock sensor 174 turns on.

[0038] The unloading operation of unloading the container C from the vehicle chassis 110 can be performed by reversing the procedure of the container loading operation described above.

[0039] -Dump operation- When performing dumping work, the mode selection switch 176 of the operation device 175 is switched to the dump operation position. When the mode selection switch 176 is in the dump operation position, the hydraulic actuator that the control device 160 drives in response to an operation signal is limited to the lift cylinder 127, and the lift cylinder 127 extends or retracts in response to the operation of the operation switch 177.

[0040] For example, when the operation switch 177 is turned upward in FIG. 5 (the "up" side), the lift cylinder 127 extends, causing the dump arm 122 to rise together with the loading / unloading arm 123. This causes the contents of the container C to be dumped. Thereafter, when the operation switch 177 is turned downward in FIG. 5 (the "down" side), the lift cylinder 127 contracts, causing the dump arm 122 to fall together with the loading / unloading arm 123.

[0041] -Motor Control- A program related to drive control of the electric motor 151 is stored in the memory of the control device 160. In accordance with this program, the control device 160 determines whether the current posture of the cargo handling apparatus 120 is a predetermined posture based on the output of the sensor, and if the current posture of the cargo handling apparatus 120 is the predetermined posture, continues driving the electric motor 151 for a predetermined time (e.g., several seconds) from the point at which operation of the operation device 175 is interrupted. If the current posture of the cargo handling apparatus 120 is other than the predetermined posture, the control device 160 immediately stops the electric motor 151 in response to the interruption of operation of the operation device 175. The predetermined posture is a posture that is set in advance for the arm 121 of the cargo handling apparatus 120, and the conditions for determining whether the posture is the predetermined posture are also stored in the memory of the control device 160. The predetermined posture of the cargo handling apparatus 120 is, for example, a posture in which the loading / unloading arm 123 of the cargo handling apparatus 120 is within a predetermined angle range during the container unloading operation.

[0042] As an example, as shown in Fig. 6, the assumed angle at which the hook 125 catches on the round bar Cb of the container C on the ground is set to θ1 (set value), and the predetermined angle range can be set to an angle range φ1 set to include this assumed angle θ1. The angle range φ1 is a range for the relative angle of the loading / unloading arm 123 with respect to the dump arm 122, and is one continuous range (e.g., θ1 ± the set angle) that includes the assumed angle θ1 within the range. The control device 160 calculates the angle of the loading / unloading arm 123 based on the output of the inclination sensor 173, and can determine whether the calculated angle is a value within the angle range φ1.

[0043] 7, the assumed angle at which the main girder Cg of the container C contacts the guide roller 130 when the container C is lifted onto the chassis 110 is set to θ2 (set value), and the predetermined angle range can be set to an angle range φ2 that is set to include this assumed angle θ2. The angle range φ2 is also a range for the relative angle of the loading / unloading arm 123 with respect to the dump arm 122, and is a single continuous range (for example, θ2 ± the set angle) that includes the assumed angle θ2 within the range. The control device 160 calculates the angle of the loading / unloading arm 123 with respect to the dump arm 122 based on the output of the inclination sensor 173, and can determine whether the calculated angle is within the angle range φ2.

[0044] The angle range φ1 illustrated in FIG. 6 and the angle range φ2 illustrated in FIG. 7 may be ranges that do not overlap at all, or they may overlap partially. Either one of the angle ranges φ1 and φ2 can be set as a predetermined angle range for the posture of the cargo handling device 120 to be a predetermined posture, or both can be set as predetermined angle ranges. The former is an example in which only one predetermined angle range is set within the swing angle range of the loading / unloading arm 123 during the container unloading operation, while the latter is an example in which two predetermined angle ranges are set. However, even in the latter case, if the angle ranges φ1 and φ2 partially overlap, the predetermined angle ranges will be combined into one wider range.

[0045] Furthermore, instead of the angle ranges φ1 and φ2, the angle of the loading / unloading arm 123 excluding the angle (=0) of the loading / unloading arm 123 when the container loading / unloading vehicle 100 is traveling can also be set as the predetermined angle range. In other words, the angle range excluding 0 degrees (the angle in the posture of FIG. 8) within the swing angle range of the loading / unloading arm 123 may be set as the predetermined angle range. In this case, the fact that the angle of the loading / unloading arm 123 is within the predetermined angle range can be detected by the slide retraction sensor 171 being on and the lift retraction sensor 172 being off. Additionally, for example, the relative angle between the dump arm 122 and the loading / unloading arm 123 based on the output of the inclination sensor 173 being other than 0, or the lock sensor 174 being off can also be used as a condition for determining that the angle of the loading / unloading arm 123 is within the predetermined angle range. Note that, in a state where the angle of the loading / unloading arm 123 is 0 degrees and the slide cylinder 128 is fully extended, i.e., in the traveling posture, inching operations related to container unloading operations are not substantially performed, but it cannot be said that inching operations are not performed when the angle of the loading / unloading arm 123 is 0 degrees but the slide cylinder 128 is not fully extended. Taking this into consideration, the condition for determining whether the angle of the loading / unloading arm 123 is within the predetermined angle range can also be that the angle of the loading / unloading arm 123 is 0 degrees and the slide cylinder 128 is fully extended.

[0046] Furthermore, it is desirable that the rotation speed N1 of the electric motor 151 during the above-mentioned predetermined time while the operating device 175 is not being operated be set lower than the rotation speed N0 of the electric motor 151 when driving the cargo handling device 120 (i.e., while the operating device 175 is being operated). The rotation speed N0 is the rotation speed required to ensure the discharge flow rate of the hydraulic pump 152 required to drive the hydraulic actuators (lift cylinder 127, slide cylinder 128). The rotation speed N1 is set to the minimum rotation speed at which the pilot pressure for driving the control valves 153, 154 can be ensured, or to a rotation speed higher than this by a predetermined margin.

[0047] -Warm-up mode- The control device 160 also has a function of driving the electric motor 151 in a warm-up mode. When the operation switch 177 is operated in a predetermined pattern with the mode selection switch 176 in the OFF position, the control device 160 drives the electric motor 151 in a predetermined warm-up mode in accordance with the operation of the operation switch 177. The predetermined operation pattern for the operation switch 177 is, for example, a predefined operation that is not normally performed during a dumping operation or a container loading / unloading operation, such as repeatedly operating the operation switch 177 in the same direction (e.g., the upward direction in FIG. 5 ) a set number of times (e.g., five times) within a set short period of time (e.g., within five seconds). The rotation speed N2 of the electric motor 151 in the warm-up mode is set lower than the rotation speed N0 of the electric motor 151 when driving the cargo handling device 120. The rotation speed N2 may be the same as or different from the rotation speed N1. When the rotation speeds N1 and N2 are set to different values, the magnitude relationship between the rotation speeds N1 and N2 is not limited.

[0048] Furthermore, when the mode selection switch 176 is switched from the OFF position to the loading / unloading operation position or the dumping operation position while the electric motor 151 is being driven in the warm-up mode, the control device 160 cancels the warm-up mode. The control device 160 may be configured to cancel the warm-up mode when the operation switch 177 is operated while the electric motor 151 is being driven in the warm-up mode, even if the mode selection switch 176 remains in the OFF position. When the warm-up mode is canceled, the control device 160 stops the electric motor 151. In this embodiment, the control device 160 also cancels the warm-up mode when the temperature T of the hydraulic oil in the hydraulic circuit 150, calculated based on the output of the thermometer 178, is within a preset temperature range (e.g., equal to or higher than the set temperature T1). For example, after starting to drive the electric motor 151 in the warm-up mode, the electric motor 151 automatically stops when the temperature T of the hydraulic oil rises to or higher than the set temperature T1, even without any operation.

[0049] -Control procedure- 9 is a flowchart showing a procedure for controlling the rotation speed of the electric motor 151 by the control device 160. While the power is on, the control device 160 repeatedly executes the process of FIG. 9 in a short processing cycle (for example, 0.1 seconds).

[0050] When the processing in FIG. 9 starts, the control device 160 first determines whether the mode selection switch 176 is in the OFF position (step S901). If the mode selection switch 176 is in the OFF position, the process proceeds to step S902. If the mode selection switch 176 is not in the OFF position, the process proceeds to step S909. When the process proceeds to step S902, the control device 160 determines whether the electric motor 151 is currently being driven in the warm-up mode (step S902). If the electric motor 151 is being driven in the warm-up mode, the control device 160 calculates the current temperature T of the hydraulic oil in the hydraulic circuit 150 based on the output of the thermometer 178 and determines whether the temperature T is equal to or higher than a set temperature T1 (step S903). If the temperature T of the hydraulic oil is equal to or higher than the set temperature T1, the control device 160 cancels the warm-up mode and stops the electric motor 151 (step S904), resets the timer to set the elapsed time t (described below) to 0 (step S905), and returns the process to step S901. If the mode selection switch 176 is in the OFF position and the current mode is not the warm-up mode, the control device 160 determines whether an operation to instruct the warm-up mode has been performed (for example, whether the operation switch 177 has been operated five times in succession) (step S906). If an operation to instruct the warm-up mode has been performed, the control device 160 turns on the warm-up mode (step S907), drives the electric motor 151 at the rotation speed N2 (step S908), resets the timer (step S905), and returns the procedure to step S901. If an operation to instruct the warm-up mode has not been performed, the control device 160 returns the procedure from step S906 to step S901.

[0051] If the mode selection switch 176 is not in the OFF position (if it is in the dump operation position or the loading / unloading operation position), the control device 160 determines whether the electric motor 151 is currently being driven in the warm-up mode (step S909). If the mode selection switch 176 has just been switched from the OFF position during warm-up mode operation, the control device 160 turns off the warm-up mode (step S910) and proceeds to step S904. If the mode selection switch 176 is not in the OFF position and the current operating mode is not the warm-up mode, the control device 160 determines whether an operation signal related to the operation of the operation switch 177 has been input in the current processing cycle (step S911). When the operation switch 177 is operated, that is, when an operation related to a container loading operation or a dumping operation is being performed, the control device 160 drives the electric motor 151 at a rotation speed N0 (step S912) to drive the hydraulic actuator (lift cylinder 127 or slide cylinder 128) according to the operation, resets the timer (step S905), and returns the procedure to step S901.

[0052] If the mode selection switch 176 is in the dump operation position or the loading / unloading operation position but the operation switch 177 is not currently being operated, the control device 160 determines whether the operation has just been interrupted (step S913). If the operation has just been interrupted, that is, if the operation signal has just changed from ON to OFF in the current processing cycle, the control device 160 determines whether the cargo handling device 120 is in a predetermined posture (step S914). If the operation has not just been interrupted (if the operation signal has been OFF since the processing cycle immediately preceding the current one), the control device 160 skips steps S914 and S915 and proceeds to step S916. Whether the cargo handling device 120 is in a predetermined posture is determined by whether the angle of the loading / unloading arm 123 is within a predetermined angle range, as described above. For example, if the aforementioned angle ranges φ1 and φ2 are set as the predetermined angle ranges, the control device 160 determines that the loading / unloading device 120 is in the predetermined position (Yes) if the angle of the loading / unloading arm 123 detected by the inclination sensor 173 is within the angle range φ1, and determines that the loading / unloading device 120 is not in the predetermined position (No) if the angle of the loading / unloading arm 123 is outside the angle range φ1.

[0053] When the cargo handling device 120 is in a predetermined posture, the control device 160 drives the electric motor 151 at the rotation speed N1 (step S915). Once the electric motor 151 is driven at the rotation speed N1, the control device 160 starts timing using a timer and counts the elapsed time t since the rotation speed of the electric motor 151 was switched to N1 (step S916). The elapsed time t is the continuous operation time of the electric motor 151 at the rotation speed N1, and is measured by counting up the interval Δt per cycle of the processing cycle in FIG. 9 each time the procedure of step S916 is executed without resetting the timer. As shown in FIG. 9, the timer is reset when the rotation speed of the electric motor 151 is other than N1 (step S905).

[0054] After executing step S916, the control device 160 determines whether the elapsed time t has reached the predetermined time t1 (step S917), and if the elapsed time t has not reached the predetermined time t1, returns to step S901. If the elapsed time t has reached the predetermined time t1, the control device 160 stops the electric motor 151 (step S918), resets the timer (step S905), and returns to step S901. Furthermore, if it has been determined in the previous step S914 that the cargo handling device 120 is not in the predetermined posture, the control device 160 quickly stops the electric motor 151, which is operating at the rotation speed N0, without switching it to the rotation speed N1 (step S918), resets the timer (step S905), and returns to step S901.

[0055] -effect- (1) In this embodiment, if the current posture of the loading / unloading device 120 is a predetermined posture, the electric motor 151 continues to be driven for a predetermined time t1 after the operation of the operating device 175 is interrupted, and if the current posture of the loading / unloading device 120 is other than the predetermined posture, the electric motor 151 is immediately stopped in response to the interruption of the operation of the operating device 175.

[0056] Therefore, when the cargo handling device 120 is in a predetermined position while it is in use, the electric motor 151 remains in operation for a predetermined time t1 after operation is interrupted even when the operating device 175 is not being operated, and when operation is resumed, hydraulic oil is quickly supplied to the hydraulic actuator, allowing the cargo handling device 120 to operate with good response. On the other hand, when the cargo handling device 120 is not in a predetermined position, the electric motor 151 stops at the point when operation of the operating device 175 is interrupted. This makes it possible to reduce power waste. Therefore, it is possible to ensure workability while reducing power consumption.

[0057] Furthermore, by continuing to drive the electric motor 151 for a predetermined time t1 after the operation is interrupted, it is possible to prevent the electric motor 151 from repeatedly starting and stopping each time the operation is interrupted and restarted, thereby also reducing mechanical damage to the electric motor 151.

[0058] (2) For example, in order to determine whether the cargo handling device 120 is in a predetermined posture, if a determination condition is set that the angle of the loading / unloading arm 123 is within a set angle range φ1 that includes the assumed angle θ1 at which the hook 125 hooks onto a container C on the ground, when the angle of the loading / unloading arm 123 is fine-tuned to align the position of the hook 125 with the round bar Cb in order to hook the hook 125 onto the round bar Cb of the container C in the operation of loading the container C onto the chassis 110, the electric motor 151 does not stop suddenly due to a short interruption of the inching operation. This prevents an increase in the time lag between the operation of the cargo handling device 120 and the inching operation, thereby enabling smooth container loading work while reducing power waste.

[0059] (3) Furthermore, during container loading and unloading operations, an inching operation is typically performed when the main girders Cg of the container C are placed on the guide rollers 130, and the container C is lifted onto the chassis 110 after confirming that the main girders Cg are securely placed on the guide rollers 130. This is because if the container C is lifted up when the main girders Cg are not securely placed on the guide rollers 130, the container C will not be properly loaded onto the chassis 110. In contrast, in order to determine whether the cargo handling device 120 is in a predetermined posture, if the determination condition is set to be that the angle of the loading / unloading arm 123 is within an angle range φ2 that is set including the assumed angle θ2 at which the container C contacts the guide rollers 130 when the container C is lifted onto the chassis 110, when the inching operation is performed as described above when the main girders Cg of the container C are placed on the guide rollers 130 during the operation of loading the container C onto the chassis 110, the electric motor 151 will not stop suddenly even if the operation is interrupted for a short period of time during the inching operation. This prevents an increase in the time lag between the operation of the cargo handling device 120 and the inching operation, allowing for smooth container loading operations while reducing power waste.

[0060] (4) When the loading / unloading arm 123 of the loading / unloading device 120 is set to a predetermined position other than the angle (=0) that it takes when traveling, the electric motor 151 stops when the loading of the container C is completed, while maintaining good overall responsiveness during the container loading / unloading operation, thereby reducing unnecessary power consumption after the loading of the container C is completed.

[0061] (5) Furthermore, if the rotation speed N1 of the electric motor 151 during a predetermined time t1 when the operating device 175 is not being operated is set lower than the rotation speed N0 of the electric motor 151 when driving the loading device 120, it is possible to suppress unnecessary power consumption of the electric motor 151 during standby operation.

[0062] (6) Generally, the loading and unloading equipment of a container loading and unloading vehicle is mainly configured to use the vehicle's engine as a prime mover, and drive a hydraulic pump with engine power extracted by a PTO. When the engine is used as a prime mover, container loading and unloading operations and dumping operations are performed with the engine running, so when container loading and unloading operations are performed, the hydraulic pump is driven when the PTO switch is turned on, and the hydraulic oil in the hydraulic circuit is warmed.

[0063] In contrast, when the hydraulic pump 152 is driven by the electric motor 151 as in this embodiment, the electric motor 151 must be driven to rotate the hydraulic pump 152 and warm the hydraulic oil. When the temperature of the hydraulic oil is low, the viscosity of the hydraulic oil is high, which reduces the smoothness of the operation of the control valves 153, 154 and reduces the responsiveness of the cargo handling device 120 to operations that require repeated interruption and resumption of operations, such as inching operations. If the responsiveness of the cargo handling device 120 is poor, it becomes difficult to make fine adjustments when hanging the hook 125 on the round bar Cb of the container C or placing the main girder Cg of the container C on the guide rollers 130 during container loading and unloading operations.

[0064] However, when the ambient temperature is high, the temperature of the hydraulic oil does not drop excessively, and warm-up operation is not necessarily required. Therefore, a configuration in which the electric motor 151 is driven unconditionally when the mode selection switch 176 is turned on, as in the conventional configuration of prime mover drive, leads to a waste of electricity. Electricity has a much lower energy density than fuel, and the amount of time that the cargo handling device 120 can be driven with a single charge or battery replacement is limited, so it is desirable to avoid wasting electricity as much as possible. In addition, adding a switch to the operating device 175 solely for the purpose of driving the electric motor 151 for warm-up purposes is not necessary, considering the frequency with which the additional switch is used.

[0065] Therefore, in this embodiment, the operation switch 177 used for container loading / unloading operations and dumping operations also serves as a switch for the warm-up operation, and the electric motor 151 is driven in a predetermined warm-up mode in accordance with the operation of the operation switch 177 in a preset pattern. This allows the operator to drive the electric motor 151 and the hydraulic pump 152 in the warm-up mode at his / her discretion, and ensures the responsiveness of the cargo handling device 120 by warming up the hydraulic oil even in a low-temperature environment.

[0066] (7) Furthermore, by setting the rotation speed N2 of the electric motor 151 in the warm-up mode lower than the rotation speed N0 of the electric motor 151 when driving the loading device 120, it is possible to prevent the consumption of more power than necessary for warm-up.

[0067] (8) Furthermore, if the warm-up mode is cancelled when the operation switch 177 is operated, the warm-up operation can be quickly switched to the container loading / unloading operation, etc., without the need to cancel the warm-up mode each time, thereby ensuring high workability.

[0068] (9) Furthermore, if the warm-up mode is configured to be automatically deactivated when the temperature of the hydraulic oil detected by the thermometer 178 is within a preset temperature range, unnecessary warm-up operations can be avoided, thereby reducing power consumption.

[0069] -Additional remarks- The present invention is not limited to the above-described embodiments and may include various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the described configurations. For example, it is possible to replace some of the configurations with other configurations. It is also possible to delete some of the configurations of the embodiments or add other configurations.

[0070] For example, while the container loading / unloading vehicle 100 has been described as an electric vehicle having an electric motor for propulsion, the vehicle may also be an engine-driven vehicle that runs using an engine as a prime mover. For example, a configuration for driving the electric motor 151 in warm-up mode is not necessary to achieve the above-described effect (1). The function for driving the electric motor 151 in warm-up mode can be installed in the container loading / unloading vehicle 100 independently of the function for continuously operating the electric motor 151 in accordance with the posture of the cargo handling device 120 when operation is interrupted. While the operation switch 177 is configured to also function as a switch for turning the warm-up mode on and off, a dedicated switch for instructing the operation device 175 to turn the warm-up mode on and off may also be provided. The rotation speeds N1 and N2 of the electric motor 151 during standby operation or warm-up operation can also be set to the same value as the rotation speed N0. Furthermore, the control device 160 may be equipped with a function for automatically reducing the rotation speed of the electric motor 151 or stopping the electric motor 151 when the temperature of the hydraulic oil detected by the thermometer 178 exceeds the upper limit of a predetermined appropriate temperature range. For example, if the temperature of the hydraulic oil rises excessively, the viscosity of the hydraulic oil will decrease, causing an increase in hydraulic oil leakage in the hydraulic circuit, which may result in an excessive drop in circuit pressure or a decrease in the operating speed of the hydraulic actuator. It may also accelerate the deterioration of the sealing material in the hydraulic oil passage, reducing its durability. Furthermore, if the oil temperature remains outside the appropriate range, the battery may be depleted more quickly due to a decrease in energy efficiency. These problems can be addressed by reducing or stopping the rotation speed of the electric motor 151 when the oil temperature rises. [Explanation of symbols]

[0071] 100...container loading / unloading vehicle, 110...chassis, 120...loading device, 123...loading arm (arm), 130...guide roller, 151...electric motor, 152...hydraulic pump, 160...control device, 171...slide retraction sensor (sensor), 172...lift retraction sensor (sensor), 173...inclination sensor (sensor), 174...lock sensor (sensor), 175...operation device, 177...operation switch (switch), 178...thermometer, C...container, N0, N1, N2...rotation speed, t1...predetermined time, T...temperature of hydraulic oil, T1...set temperature, θ1, θ2...expected angle, φ1, φ2...angle range (predetermined angle range)

Claims

1. In a container loading / unloading vehicle that loads and unloads containers onto a vehicle chassis, An electric motor; a hydraulic pump driven by the electric motor; a cargo handling device whose posture is changed by being driven by hydraulic oil discharged from the hydraulic pump; a sensor for detecting the attitude of the cargo handling device; An operating device; a control device that controls the loading device in response to an operation signal from the operation device; Equipped with The control device determining whether the current posture of the cargo handling device is a predetermined posture based on the output of the sensor; If the current position of the cargo handling device is the predetermined position, driving of the electric motor is continued for a predetermined time from when operation of the operating device is interrupted; When the current position of the cargo handling device is other than the predetermined position, the electric motor is stopped in response to interruption of operation of the operating device. A container detachable vehicle.

2. The container detachable vehicle according to claim 1, The predetermined position is a position in which the arm of the loading / unloading device is within a predetermined angle range during the container loading / unloading operation.

3. The container detachable vehicle according to claim 2, The container loading / unloading vehicle is characterized in that the predetermined angle range is an angle range set to include an expected angle at which the vehicle will get caught on a container on the ground.

4. The container detachable vehicle according to claim 2, A container loading / unloading vehicle characterized in that the specified angle range is an angle range set to include an expected angle at which the container will contact the guide rollers when the container is lifted.

5. The container detachable vehicle according to claim 2, A container loading / unloading vehicle, wherein the predetermined angle range is an angle excluding an angle taken by the arm of the loading / unloading device when the vehicle is traveling.

6. The container detachable vehicle according to any one of claims 1 to 5, A container loading / unloading vehicle characterized in that the rotation speed during the predetermined time is set to be equal to or less than the rotation speed of the electric motor when driving the loading / unloading device.

7. The container detachable vehicle according to any one of claims 1 to 5, The operating device includes a switch for instructing a container loading / unloading operation, The container loading / unloading vehicle is characterized in that the control device drives the electric motor in a predetermined warm-up mode in response to operation of the switch in a preset pattern.

8. The container detachable vehicle according to claim 7, A container loading / unloading vehicle characterized in that the rotation speed of the electric motor in the warm-up mode is set lower than the rotation speed of the electric motor when driving the loading / unloading device.

9. The container detachable vehicle according to claim 7, The container loading / unloading vehicle is characterized in that the control device cancels the warm-up mode when the switch is operated while the electric motor is being driven in the warm-up mode.

10. The container detachable vehicle according to claim 7, a thermometer for measuring the temperature of the hydraulic oil; The container detachment vehicle is characterized in that the control device cancels the warm-up mode when the temperature of the hydraulic oil detected by the thermometer is within a preset temperature range.

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