JP7478188B2 - forklift - Google Patents

Description

The present invention relates to a forklift for containers.

A known conventional forklift is a forklift for empty containers that is equipped with a vehicle body provided with a mast device and a spreader device that moves up and down along the mast device while holding a container (see, for example, Patent Document 1).

As shown in FIG. 10, when placing container C2 on top of container C1, an operator of a conventional forklift 1C aims at the center of container C1 by relying on his or her own sense, and stacks container C2 on top of container C1 while aligning the center of container C1 with the center of container C2. If the position of container C2 shifts, the operator must side-shift the spreader device or move the forklift 1C forward or backward to align the center of container C1 with the center of container C2. For this reason, with the conventional forklift 1C, differences in work speed occur depending on the skill and experience of the operator.

Japanese Patent Application Laid-Open No. 11-228092

The present invention was made in consideration of the above circumstances, and its objective is to provide a forklift that can improve the efficiency of work speed when placing containers.

In order to solve the above problems, the forklift according to the present invention comprises:
A vehicle body provided with a mast device;
a spreader device that moves up and down along the mast device while holding a container;
A forklift for containers comprising:
a tilt unit that tilts the mast assembly in a front-rear direction;
a laser line marker unit that, when in an on state, irradiates a laser light to display a container side line extending in the front-rear direction on a road surface;
a laser control unit that controls the on state of the laser line marker unit,
The laser control unit includes:
The present invention is characterized in that the laser line marker unit is turned on when a first condition is satisfied, that is, the spreader device is holding the container, and a second condition is satisfied, that is, the mast device is in a neutral position without tilting.

According to this configuration, a laser beam is emitted to display a container side line extending in the fore-and-aft direction on the road surface, so that a worker can place the container in a designated location by looking at the container side line, thereby improving the efficiency of work speed. In addition, according to this configuration, when the first and second predetermined conditions are met, the laser line marker unit is turned on, so that constant irradiation of the laser beam can be avoided.

In the forklift,
The spreader device includes a twist lock unit that is fixed to the container in a locked-on state and is detachable from the container in an unlocked state,
The laser control unit may be configured to determine that the first condition is satisfied when the twist lock unit is in the locked-on state.

The forklift is
a sensor unit for detecting the neutral position of the mast assembly,
The sensor unit includes:
a first member provided on the vehicle body so as to protrude from the vehicle body toward the mast assembly;
a second member that is provided on the mast assembly so as to protrude from the mast assembly toward the vehicle body and that moves together with the mast assembly;
a proximity switch provided on one of the first member and the second member;
a detection object of the proximity switch provided on the other of the first member and the second member,
the proximity switch detects the object to be detected when the mast assembly is in the neutral position,
The laser control unit can be configured to determine that the second condition is satisfied while the proximity switch detects the object to be detected.

In the forklift,
The laser line marker unit is
A laser device that irradiates the laser light;
and an angle adjustment unit capable of adjusting an angle of the laser device with respect to the road surface,
The vehicle body includes a pair of left and right front fenders,
The angle adjustment portion can be configured to be provided on a portion of a side surface of at least one of the pair of left and right front fenders.

In the forklift,
the fender includes a front plate, a top plate, a side plate, and a housing portion provided at a connecting portion of the top plate and the side plate to house the angle adjustment portion,
The housing portion includes a front plate and a rear plate,
The angle adjustment unit is
an angle adjustment plate on which the laser device is disposed;
a connecting plate connected to the angle adjustment plate so as to overlap one of the front plate and the rear plate of the storage section;
a hinge connecting the angle adjustment plate and the upper plate;
A fixing bolt that fixes the connecting plate and the plate of the accommodation portion,
a bolt hole into which the fixing bolt is inserted is provided in one of the connection plate and the plate of the accommodation portion;
The other of the connecting plate and the plate of the accommodating portion may be configured to have an elongated hole into which the fixing bolt is inserted.

The forklift is
a second laser line marker unit that, when in an on state, irradiates a laser light to display a container front line extending in the left-right direction on the road surface;
The laser control unit is
When the first condition and the second condition are satisfied, the second laser line marker unit can be turned on to display the intersection of the container front line and the container side line on the road surface.

The present invention provides a forklift that can improve the efficiency of work speed when placing containers.

1 is a side view of a forklift according to an embodiment of the present invention. 1 is a perspective view of a forklift according to an embodiment of the present invention. FIG. 2A is a perspective view of a sensor unit according to one embodiment of the present invention, and FIG. 2B is a plan view of the sensor unit. 1A and 1B are perspective views of a front fender according to an embodiment of the present invention, in which FIG. 1A is a perspective view seen from the front side, and FIG. 1B is a perspective view seen from the rear side. 1A is a perspective view of a laser line marker unit according to one embodiment of the present invention, and FIG. 1B is a perspective view showing the laser line marker unit attached to a front fender. FIG. 4 is a control flow diagram of a laser control unit according to an embodiment of the present invention. 1 is a diagram for explaining a loading/unloading operation of a forklift according to an embodiment of the present invention; 13A to 13C are diagrams for explaining a loading and unloading operation of a forklift according to a modified example of the present invention. 1A is a perspective view of a laser line marker unit according to a modified example of the present invention, and FIG. 1B is a perspective view showing the laser line marker unit attached to a front fender. FIG. 1 is a diagram for explaining a loading and unloading operation of a conventional forklift truck.

Below, an embodiment of the forklift according to the present invention will be described with reference to the attached drawings. Note that the directions of front, back, left, right, top and bottom are those seen from the perspective of an operator in the driver's seat of the forklift.

Figure 1 shows a container forklift 1A according to one embodiment of the present invention. In this embodiment, the forklift 1A is configured to transport an empty container C, but it may also be configured to transport not only empty containers C, but also containers that contain contents.

The forklift 1A comprises a vehicle body 2 made up of multiple frames, a mast device 3 provided at the front of the vehicle body 2, and a spreader device 20 that moves up and down along the mast device 3.

The vehicle body 2 is equipped with a tilt section 4 connected to the mast device 3. The tilt section 4 includes a pair of left and right tilt cylinders, and the mast device 3 is tilted in the forward and backward directions by extending and retracting the tilt cylinders.

The vehicle body 2 includes a driver's seat 5 located at the top, front wheels 6 and rear wheels 7 located at the bottom, and an operating unit and a control unit (not shown) provided at the driver's seat 5. Note that at least a portion of the control unit can be provided in a location separate from the driver's seat 5.

The operation unit includes a loading lever, forward/reverse lever, steering wheel, etc. that can be operated by an operator in the driver's seat 5. The control unit is composed of digital and/or analog circuits including a microcomputer, etc., and controls the mast device 3, tilt unit 4, spreader device 20, etc. in response to operation of the operation unit. For example, by operating the loading lever of the operation unit, the operator can extend and retract the mast device 3 in the vertical direction, or raise and lower the spreader device 20 holding a container C along the mast device 3.

As shown in FIG. 2, the spreader device 20 includes an attachment section 21, an extension section 22, a support section 23, and a twist lock section 24. The attachment section 21 has a rear section that is attached to the mast device 3 so that it can be raised and lowered, and has an extension section 22 provided at its front section. The extension section 22 is configured to extend and retract in the left-right direction in response to the operation of the operating section. The support sections 23 are provided at both the left and right ends of the extension section 22 and extend upward. The distance between the support sections 23 changes as the extension section 22 extends and retracts.

The twist lock unit 24 is provided on the upper part of the support unit 23. The twist lock unit 24 has a twist lock pin that protrudes downward. The twist lock pin operates (e.g., rotates 90°) in response to the operation of the operating unit, and switches between a locked-on state in which it is fixed to the hanging hole on the top surface of the container C, and an unlocked state in which it can be removed from the hanging hole of the container C. Note that switching from the locked-off state to the locked-on state may be performed automatically when the twist lock pin is inserted into the hanging hole of the container C.

When the twist lock unit 24 is in the locked-on state, the forklift 1A can hold and transport the container C with the spreader device 20. On the other hand, when the twist lock unit 24 is in the unlocked state, the forklift 1A cannot hold the container C with the spreader device 20.

The vehicle body 2 is equipped with a sensor unit 30 that detects the neutral position of the mast device 3. The neutral position is a position in which the mast device 3 is perpendicular to the road surface as shown in FIG. 1, and is a position in which the mast device 3 is not tilted in the fore-aft direction. The sensor unit 30 is provided near the tilt cylinder on the right side of the tilt unit 4.

Figure 3 (A) shows an oblique view of the sensor unit 30, and Figure 3 (B) shows a plan view of the sensor unit 30. Note that Figures 3 (A) and (B) show the mast assembly 3 in a neutral position. The sensor unit 30 includes a first member 31, a proximity switch 32, a second member 33, and a detected object 34.

The first member 31 is a metal plate having one end and the other end, and one end is attached to the vehicle body 2 so as to protrude from the vehicle body 2 toward the mast device 3. A proximity switch 32 is attached to the other end of the first member 31.

The second member 33 is a metal plate having one end and the other end, and a detection object 34 is provided at one end by bending the metal plate upward. The other end of the second member 33 is attached to the mast device 3 so that the second member 33 protrudes from the mast device 3 toward the vehicle body 2. The second member 33 moves together with the mast device 3.

When the mast assembly 3 is in the neutral position, the proximity switch 32 and the object to be detected 34 face each other, and the proximity switch 32 detects the object to be detected 34 and outputs a detection signal to the control unit. When the mast assembly 3 tilts forward, the second member 33 moves forward and the object to be detected 34 moves away from the proximity switch 32, so the proximity switch 32 does not detect the object to be detected 34. When the mast assembly 3 tilts backward, the second member 33 moves backward and the object to be detected 34 moves away from the proximity switch 32, so the proximity switch 32 does not detect the object to be detected 34. In this embodiment, the proximity switch 32 is provided on the first member 31 and the object to be detected 34 is provided on the second member 33, but the object to be detected 34 may be provided on the first member 31 and the proximity switch 32 on the second member 33.

The vehicle body 2 is equipped with a pair of left and right front fenders 8. The front fenders 8 function to protect against mud, rain, and stone splashes caused by the front wheels 6 while driving. A laser line marker unit 40 is attached to the right front fender 8.

Figure 4(A) shows a perspective view of the right front fender 8 seen from the front side, and Figure 4(B) shows a perspective view of the right front fender 8 seen from the rear side. The front fender 8 comprises a front plate 9, a top plate 10, and a side plate 11.

Notches 10A, 11A are formed in the connecting portion of the top plate 10 and the side plate 11, and the notches 10A, 11A form a storage section (storage space) for storing the laser line marker section 40. The storage section has a front plate 12 on the front side and a rear plate 13 on the rear side, and is open on the bottom.

The front plate 12 has a bolt hole 12A and a fixing nut for inserting a fixing bolt (not shown). In this embodiment, the bolt hole 12A is a round hole, and the fixing nut is welded to the front side of the front plate 12.

Figure 5 (A) shows a perspective view of the laser line marker unit 40, and Figure 5 (B) shows a perspective view of the laser line marker unit 40 housed in the housing of the front fender 8.

The laser line marker unit 40 includes a laser device 41, an angle adjustment plate 42, a connecting plate 43, a hinge 44, and a fixing bolt (not shown), which constitute the "angle adjustment unit" of the present invention.

The laser device 41 includes a laser element that emits laser light under the control of the control unit, and a lens for spreading the laser light into a fan shape. The control unit that controls the laser element as described above is the "laser control unit" of the present invention. The laser light L of the laser device 41 is emitted diagonally downward to the side of the vehicle body 2, and displays a container side line SL extending in the fore-and-aft direction on the road surface so that it can be seen by the operator in the driver's seat 5 (see Figure 7).

A laser device 41 is disposed on the upper surface of the angle adjustment plate 42. Because the laser device 41 is disposed above the lower end 42A of the angle adjustment plate 42, the front fender 8 provided on the side plate 11 functions to prevent the front wheel 6 from affecting the vehicle while driving, including mud, rain, and stone splashes.

The connecting plate 43 is connected to the angle adjustment plate 42 so as to overlap the front plate 12. In this embodiment, the connecting plate 43 and the angle adjustment plate 42 are made by bending a single metal plate. The connecting plate 43 has an elongated hole 43A into which a fixing bolt is inserted.

The hinge 44 is configured to connect the angle adjustment plate 42 and the top plate 10. One piece of the hinge 44 is attached to the upper end 42B side of the bottom surface of the angle adjustment plate 42, and the other piece is attached to the bottom surface of the top plate 10.

The fixing bolt is inserted into the long hole 43A in the connecting plate 43, the bolt hole 12A in the front plate 12, and the fixing nut to fix the connecting plate 43 and the front plate 12.

In this embodiment, the angle of the angle adjustment plate 42 can be adjusted within the range of the elongated hole 43A. In other words, the position of the container side line SL can be adjusted by adjusting the positional relationship between the bolt hole 12A and the elongated hole 43A to adjust the angle of the angle adjustment plate 42. After adjusting the angle of the angle adjustment plate 42, the connecting plate 43 and the front plate 12 are fixed with a fixing bolt.

In addition, the connecting plate 43 in this embodiment is connected to the front side of the angle adjustment plate 42 so as to overlap with the front plate 12, but it may also be connected to the rear side of the angle adjustment plate 42 so as to overlap with the rear plate 13. In that case, it is necessary to provide the rear plate 13 with a bolt hole and a fixing nut for inserting the fixing bolt.

Figure 6 shows the control flow of the control unit (laser control unit). When the power is turned on, the control unit starts the control flow shown in Figure 6. When the control flow starts, the laser line marker unit 40 is in the off state. When the laser line marker unit 40 is in the off state, no power supply voltage is supplied to the laser device 41, so the laser light L is not emitted.

The control unit, which has started the control flow, determines whether the first condition, that is, the spreader device 20 is holding a container C, is met (S1). When an operation is performed in the operation unit to lock the twist lock unit 24 into the on state, the control unit rotates the twist lock pin of the twist lock unit 24 to lock it into the on state. When the twist lock unit 24 is in the locked on state, the control unit determines that the first condition is met (Yes in S1).

When the control unit determines that the first condition is met, it then determines whether the second condition, that is, the mast assembly 3 is in the neutral position, is met (S2). When the mast assembly 3 is in the neutral position, the proximity switch 32 detects the object to be detected 34 and outputs a detection signal to the control unit. By receiving the detection signal, the control unit determines that the second condition is met (Yes in S2).

When the control unit determines that the second condition is satisfied, it turns on the laser line marker unit 40 (S3). This causes the laser device 41 to emit laser light L, and a container side line SL extending in the fore-and-aft direction is displayed on the road surface. Note that the processing of steps S1 and S2 may be performed simultaneously, or step S2 may be performed first.

On the other hand, if the spreader device 20 is not holding a container C in step S1, i.e., if the twist lock unit 24 is in the unlocked state, the control unit determines that the first condition is not met (No in S1). Also, if the mast device 3 is in the forward or rearward tilted position in step S2, i.e., if no detection signal is output from the proximity switch 32, the control unit determines that the second condition is not met (No in S2).

If the control unit determines that the first or second condition is not satisfied, it keeps the laser line marker unit 40 in the off state (S4). This makes it possible to prevent the laser device 41 from constantly emitting the laser light L.

As described above, according to the forklift 1A of this embodiment, when the first condition that the spreader device 20 is holding a container C and the second condition that the mast device 3 is in a neutral position are satisfied, the laser light L is irradiated to display the container side line SL extending in the fore-and-aft direction on the road surface.

As shown in Figure 7, the operator of forklift 1A can view the container side line SL from the driver's seat 5 and place container C2 in the designated location (on top of container C1 in Figure 7), thereby improving work speed and efficiency.

[Modification]
Although the embodiment of the forklift according to the present invention has been described above, the present invention is not limited to the above embodiment.

Figure 8 shows a modified example of a forklift 1B. The forklift 1B is the same as the forklift 1A of the above embodiment, except that it is equipped with a second laser line marker unit 50 in addition to the first laser line marker unit 40. The laser line marker unit 50 displays a container front line FL extending in the left-right direction on the road surface.

Figure 9 (A) shows a perspective view of the laser line marker unit 50, and Figure 9 (B) shows a perspective view of the laser line marker unit 50 attached to the front fender 8.

The laser line marker unit 50 includes a laser device 51, an angle adjustment plate 52, a connecting plate 53, a hinge 54, and a fixing bolt 55. The front plate 9 of the front fender 8 is provided with a cutout portion 9A for positioning the laser line marker unit 50, and the side plate 11 is provided with a long hole 11A.

The laser device 51 includes a laser element that emits laser light under the control of the control unit, and a lens for spreading the laser light into a fan shape. The laser light L' from the laser device 51 is emitted diagonally downward and forward of the vehicle body 2, and displays a container front line FL extending in the left-right direction on the road surface so that it can be seen by the operator in the driver's seat 5 (see FIG. 8).

The angle adjustment plate 52 is placed in the cutout 9A of the front plate 9, and functions as a front fender 8 together with the front plate 9. A laser device 51 is placed on the front side of the angle adjustment plate 52. Since the laser device 51 is placed behind the front end 52A of the angle adjustment plate 52, the angle adjustment plate 52's function as a front fender 8 makes it possible to avoid the effects of mud, rain, and stone splashes caused by the front wheel 6 while driving.

The connecting plate 53 is connected to the angle adjustment plate 52 so as to overlap the side plate 11. The connecting plate 53 and the angle adjustment plate 52 are made by bending a single metal plate. The connecting plate 53 has a bolt hole 53A and a fixing nut for inserting the fixing bolt 55. The bolt hole 53A is a round hole, and the fixing nut is welded to the connecting plate 53.

The hinge 54 is configured to connect the angle adjustment plate 52 and the front plate 9. One piece of the hinge 54 is attached to the rear end 52B side of the rear surface of the angle adjustment plate 52, and the other piece is attached to the rear surface of the front plate 9.

The fixing bolt 55 is inserted into the long hole 11A in the side plate 11, the bolt hole 53A in the connecting plate 53, and the fixing nut to fix the side plate 11 and the connecting plate 53.

In this modified example, the angle of the angle adjustment plate 52 can be adjusted within the range of the elongated hole 11A. In other words, the position of the container front line FL can be adjusted by adjusting the angle of the angle adjustment plate 52 by adjusting the positional relationship between the bolt hole 53A and the elongated hole 11A. After adjusting the angle of the angle adjustment plate 52, the side plate 11 and the connecting plate 53 are fixed with the fixing bolt 55.

The control unit controls the second laser line marker unit 50 in the same manner as the first laser line marker unit 40. That is, when the first condition that the spreader device 20 is holding a container C and the second condition that the mast device 3 is in a neutral position are satisfied, the control unit causes the laser device 51 to emit laser light L' to display a container front line FL extending in the left-right direction on the road surface.

According to this modified example, as shown in FIG. 8, by displaying the container side line SL and the container front line FL, it is possible to display the intersection X between the container side line SL and the container front line FL. Therefore, the operator of the forklift 1B can view the container side line SL, the container front line FL, and the intersection X from the driver's seat 5 and place the container C2 in the designated location (above the container C1 in FIG. 8), which can further improve the efficiency of the work speed.

[Other Modifications]
The forklift of the present invention is a forklift for containers comprising a vehicle body provided with a mast device and a spreader device that rises and falls along the mast device while holding a container, and comprises a tilt unit that tilts the mast device in the forward and backward directions, a laser line marker unit that, when on, irradiates laser light to display a container side line extending in the forward and backward directions on the road surface, and a laser control unit that controls the on state of the laser line marker unit, and the configuration of the laser control unit can be modified as appropriate so long as it turns on the laser line marker unit when a first condition is satisfied that the spreader device is holding a container, and a second condition is satisfied that the mast device is in a neutral position.

For example, in the above embodiment, the laser line marker unit 40 is attached to the right front fender 8, but it may be attached to the left front fender 8, or to both the left and right sides. The same applies to the laser line marker unit 50.

DESCRIPTION OF SYMBOLS 1A, 1B Forklift 2 Vehicle body 3 Mast device 4 Tilt section 5 Driver's seat 6 Front wheel 7 Rear wheel 8 Front fender 9 Front plate 10 Top plate 11 Side plate 12 Front plate 13 Rear plate 20 Spreader device 21 Mounting section 22 Expandable section 23 Support section 24 Twist lock section 30 Sensor section 31 First member 32 Proximity switch 33 Second member 34 Object to be detected 40, 50 Laser line marker section 41, 51 Laser device 42, 52 Angle adjustment plate 43, 53 Connection plate 44, 54 Hinge 55 Fixing bolt

Claims (6)

A vehicle body provided with a mast device;
a spreader device that moves up and down along the mast device while holding a container;
A forklift for containers comprising:
a tilt unit that tilts the mast assembly in a front-rear direction;
a laser line marker unit that, when in an on state, irradiates a laser light to display a container side line extending in the front-rear direction on a road surface;
a laser control unit that controls the on state of the laser line marker unit,
The laser control unit includes:
A forklift characterized in that the laser line marker unit is turned on when a first condition is satisfied, that is, the spreader device is holding the container, and a second condition is satisfied, that is, the mast device is in a neutral position without tilting. The spreader device includes a twist lock unit that is fixed to the container in a locked-on state and is detachable from the container in an unlocked state,
2. The forklift according to claim 1, wherein the laser control unit determines that the first condition is satisfied when the twist lock unit is in the locked-on state. a sensor unit for detecting the neutral position of the mast assembly,
The sensor unit includes:
a first member provided on the vehicle body so as to protrude from the vehicle body toward the mast assembly;
a second member that is provided on the mast assembly so as to protrude from the mast assembly toward the vehicle body and that moves together with the mast assembly;
a proximity switch provided on one of the first member and the second member;
a detection object of the proximity switch provided on the other of the first member and the second member,
the proximity switch detects the object to be detected when the mast assembly is in the neutral position,
2. The forklift according to claim 1, wherein the laser control unit determines that the second condition is satisfied while the proximity switch detects the object to be detected. The laser line marker unit is
A laser device that irradiates the laser light;
and an angle adjustment unit capable of adjusting an angle of the laser device with respect to the road surface,
The vehicle body includes a pair of left and right front fenders,
2. The forklift according to claim 1, wherein the angle adjustment portion is provided on a part of a side surface of at least one of the pair of left and right front fenders. the fender includes a front plate, a top plate, a side plate, and a housing portion provided at a connecting portion of the top plate and the side plate to house the angle adjustment portion,
The housing portion includes a front plate and a rear plate,
The angle adjustment unit is
an angle adjustment plate on which the laser device is disposed;
a connecting plate connected to the angle adjustment plate so as to overlap one of the front plate and the rear plate of the storage section;
a hinge connecting the angle adjustment plate and the upper plate;
A fixing bolt that fixes the connecting plate and the plate of the accommodation portion,
a bolt hole into which the fixing bolt is inserted is provided in one of the connecting plate and the plate of the accommodation portion;
5. The forklift according to claim 4, wherein the other of the connecting plate and the plate of the storage section is provided with an elongated hole into which the fixing bolt is inserted. a second laser line marker unit that, when in an on state, irradiates a laser light to display a container front line extending in the left-right direction on the road surface;
The laser control unit is
2. The forklift according to claim 1, characterized in that, when the first condition and the second condition are satisfied, the second laser line marker unit is turned on to display the intersection of the container front line and the container side line on the road surface.

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