JP3140012B2 - Forklift with traversing system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forklift having a traversing system capable of switching to traversing traveling.

[0002]

2. Description of the Related Art Conventionally, vehicles having a traversing system are found in large-sized transport vehicles, some loaders, and the like, and in forklifts, reach-type electric vehicles exist. Also,
There is a side forklift that handles long objects, with masts and forks attached horizontally to the movement of the vehicle. However, there is no counter-type engine forklift capable of traversing and having the same function as a side fork in addition to the usual work.
In order to establish such a forklift, it is necessary to steer the drive wheels (front wheels) and the turning wheels (rear wheels) so as to face right beside. At that time, both drive wheels are independently turned by an actuator such as a cylinder.

[0003]

However, in the conventional forklift, when turning the turning wheel to the side, the turning by the handle wheel during the normal running and the turning in the horizontal direction at the time of traversing are compatible. Was difficult. In addition, as a method of achieving both the turning by the handle wheel during normal traveling and the turning in the lateral direction during traversing,
There is a method of changing the turning wheel (steering axle) to one wheel (three-wheeled vehicle type). In this case, if the steering wheel is turned to the locked state at the time of traversing, the diverting wheel can be traversed with the sideways direction, but the three-wheeled vehicle type is less stable than the four-wheeled vehicle type.

[0004] Therefore, the invention described in claim 1 of the present invention has the following four aspects.
It is an object of the present invention to provide a forklift having a traversing system capable of turning during normal traveling and traversing while being a wheel type. Another object of the present invention is to provide a forklift having a traversing system in which switching control from normal traveling to traversing traveling can be smoothly performed by operating a common traversing control valve. .

[0005]

In order to achieve the above-mentioned object, a forklift having a traversing system according to claim 1 of the present invention comprises a vehicle body comprising a pair of left and right front wheels and a pair of left and right rear wheels. Each of the pair of left and right front wheels is connected to a drive shaft of a traveling drive unit in an interlocking manner, and both traveling drive units rotate about a vertical axis with respect to the vehicle body side. A front wheel rotating device is provided to freely rotate, and a pair of left and right rear wheels are rotatably provided around a vertical axis with respect to the vehicle body side and rotate. A rear wheel rotation device is provided,
This rear wheel turning device has a turning cylinder and a rear wheel traversing cylinder, and the turning cylinder has a main body that is a car.
It is attached to the body side and the piston rod is
Projected on both sides of the direction, and the projected of the piston rod
Left and right rear wheels on the holding frame provided between the two
The main body of the traversing cylinder is attached and
Each of the stone rods protrudes outward in the vehicle width direction,
Relatively rotatable connection to the turning member with the rear wheel mounted
Is, the rear wheel transverse cylinder are those換向cylinder is characterized in that a predetermined non-operation position is a rear wheel during operation of the other in rotated Rutotomoni,換向cylinder when the neutral form It is.

Therefore, according to the first aspect of the present invention, the right and left front wheels and the right and left rear wheels are oriented in the front-rear direction during normal traveling. During normal running, when turning the steering wheel left and right and operating the turning cylinder with the orbit roll, the cylinders for traversing both rear wheels are in a predetermined non-operation position and play a link-like role. Can turn and turn the rear wheel in accordance with the operation of the vehicle. In addition, when the turning cylinder is operated to the limit, the left and right rear wheels can be turned in a reverse C-shape, thereby enabling turning on the spot.

When switching from normal traveling to traversing traveling, for example, a lever type traversing mode switch is operated,
The front wheel rotation device and the rear wheel rotation device are operated. That is, the front wheel rotating device is operated to rotate the front wheel around the vertical axis, thereby turning the vehicle 90 degrees (directly to the side) with respect to the vehicle body. Here, since the front wheels are each integrated with the traveling drive device, the 90-degree turning can be easily and smoothly performed.

In addition, the rear wheel rotating device is operated to rotate the rear wheel around the vertical axis so that the rear wheel is turned by 90 degrees (directly to the side). At that time, the rear wheel turning device operates the rear wheel traversing cylinder in a state where the turning cylinder is in the neutral (straight) position, so that the turning of the rear wheel by 90 degrees can be easily and smoothly performed. I can do it. After the front wheels and the rear wheels are turned right and left in this manner, the forklift can be traversed right and left by driving the front wheels in the forward and reverse directions by the traveling drive device. At this time, the pair of left and right rear wheels are rotated following.

According to a second aspect of the present invention, there is provided a forklift having a traversing system according to the first aspect, wherein the front wheel rotating device has a front wheel traversing cylinder, and the front wheel traversing cylinder and the rear cylinder. The wheel traverse cylinder is connected in parallel to a common traverse control valve via an open / close valve, and the traverse operation opens the rear wheel side open / close valve, and the traverse control valve operates the rear wheel traverse cylinder. Move the cylinder to the traversing side,
Then, by detecting a lateral completion of the rear wheels, it is obtained by said the rear wheel off valve causes the work motion is configured to opening operation of the front wheel off valve.

Therefore, according to the second aspect of the invention, when the traverse mode switch is operated, first, only the rear wheel side opening / closing valve is opened, and the rear wheel traverse cylinder is operated by operating the traverse control valve. The wheels can be turned 90 degrees relative to the vehicle body. Then, by detecting the completion of turning of the rear wheel, the rear wheel opening / closing valve is closed and the front wheel opening / closing valve is opened, so that the front wheel traversing cylinder is operated by operating the traversing control valve. The wheels can be turned 90 degrees relative to the vehicle body.

As a result, the traversing mode is made possible. Therefore, the forklift can be traversed right and left by driving the front wheels in the forward and reverse directions via the traveling drive device.
During this traversing, the front-wheel side opening / closing valve is in the operating state. Therefore, by operating the traversing control valve appropriately, the front-wheel traversing cylinder can be moved only in the specified range. This makes it possible to perform position, turning, correction, and the like during traversing.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below.
The state adopted in a normal forklift will be described with reference to FIGS. 1 to 4, a forklift 1 having a traversing system is provided with a pair of left and right front wheels (drive wheels) 3 at a front portion of a vehicle body 2.
A pair of right and left rear wheels (redirect wheels) 4 are provided at the rear, and a driver's seat 5 is provided above the front of the vehicle body 2. At the front end of the vehicle body 2, a mast 6 that can expand and contract vertically is provided.
A tilt cylinder 8 is provided between the vehicle body 2 and the mast 6 so as to be rotatable in the front-rear direction via a connecting shaft 7 in the vehicle width direction and to rotate back and forth.

The mast 6 comprises a pair of left and right outer frames 9 on the forklift 1 side, and a pair of left and right inner frames 10 which are guided by the outer frames 9 and can move up and down.
0 is provided with a lift cylinder 11. In addition, a lift bracket 12 that is guided by the inner frame 10 and that can move up and down is provided.
A pair of left and right forks 13 is provided via a pair of upper and lower finger bars.

The driver's seat 5 is provided with a seat 15 and a handle 16 located in front of the seat 15.
A head guard 19 is disposed above the head guard 19 via a front pipe 17 and a rear pipe 18 erected from the main body 2 side. Further, a counterweight 20 is provided on the main body 2 behind the seat 15. The pair of left and right front wheels 3 and the pair of right and left rear wheels 4 are provided so as to be able to turn 90 degrees relative to the vehicle body 2 (turn right next to the vehicle body 2). That is, the pair of left and right front wheels 3 is
Are directly attached to a rotating flange (drive shaft) 22 of a hydraulic motor (travel driving device) 21 via a connecting member 23, so that they are linked to the hydraulic motor 21 side.

The mounting of the hydraulic motor 21 is reverse L
The horizontal plate portion of the turning member 24 is attached horizontally to the vertical plate portion of the U-shaped turning member 24.
5 and the longitudinal axis 26, the longitudinal axis 27 with respect to the vehicle body 2 side.
Are provided so as to be rotatable around. At that time, the vertical axis 2
7 is configured to be located directly above the front wheel 3.

The hydraulic motor 21, that is, the turning member 2
4 is provided with a front wheel rotating device 30 for performing the rotation. The front wheel rotating device 30 has a front wheel traversing cylinder 31. The front wheel traversing cylinder 31 has a main body 31a attached to the vehicle body 2 via a vertical pin 32 so as to be swingable, and a pin ton rod 30b. One side pivot member 24
Is rotatably connected to a link 33 fixed to the base via a connecting pin 34 in the vertical direction. And the left and right vertical axis 2
The arms 35 connected from 6 are connected to each other via a link body 36 and a connecting pin 37 so as to be relatively rotatable.

Therefore, by turning the turning member 24 via the link 33 by the operation of the front-wheel traversing cylinder 31, the front wheel 3 on one side is turned around the longitudinal axis 27 and turned rightward. At the same time, the front wheel 3 on the other side can be turned around the longitudinal axis 27 and directed to the side via the arm 35 and the link body 36. That is, the front wheel rotating device 30
According to this, the left and right front wheels 3 are turned in the same direction by the operation of the common front wheel traversing cylinder 31, and are directed to the side. An example of the front wheel rotating device 30 is configured by the above-described 31 to 37 and the like.

In FIG. 7, an engine 40 and a pair of pumps 41 driven by the engine 40 are provided on the vehicle body 2 side. Then, the pump 41 is made to correspond to one hydraulic motor 21, that is, a two-pump two-motor type hydraulic drive system (HS
The corresponding pump 41 and the hydraulic motor 21 are connected via a pipe (eg, a hydraulic hose) 42 so as to form a T system).

1 to 4, a pair of left and right rear wheels 4 is provided.
The rim 4A is freely rotatably attached to a vertical plate portion of the turning member 45 via a lateral axle 46 or the like, and the horizontal plate portion of the turning member 45 is
Via a bearing 47 and a longitudinal axis 48, it is provided rotatably around a longitudinal axis 49 with respect to the vehicle body 2. A rear wheel turning device 50 for turning the pair of right and left rear wheels 4 around a vertical axis 49 is provided. The rear wheel turning device 50 is composed of a turning cylinder 51, a rear wheel traversing cylinder 53, and the like. You.

That is, the main body 51a of the turning cylinder 51 is attached to the vehicle body 2, and the piston rod 51c connected to the piston 51b protrudes on both sides in the vehicle width direction. A holding frame 52 is provided between both protruding ends of the piston rod 51c. Main bodies 53a of a pair of left and right rear wheel traversing cylinders 53 are attached to the holding frame 52, and piston rods 53c connected to the pistons 53b of the rear wheel traversing cylinders 53 project outward in the vehicle width direction. Have been. The arm 54 and the protruding end of the piston rod 53c are connected to each other via the link 55 and the vertical connecting pins 56 and 57 so as to be relatively rotatable. .

The turning cylinder 51 includes a handle 1
By turning 6, an orbit roll (all hydraulic power steering) 58 is configured to perform left-right operation and the like. The rear-wheel traversing cylinder 53 is provided as a pair of right and left rear wheels 4 by turning the control valve 59 when the diverting cylinder 51 is in a neutral state so that the rear wheels 4 can be individually rotated. At the time of operation of 51, it is configured to assume a predetermined non-operation posture.

Therefore, by operating the rear wheel traversing cylinder 53, the vertical axis 48 is rotated through the link 55, the arm body 54, and the like, so that the rear wheel 4 is rotated through the turning member 45 and the like. Can turn around and turn sideways. In other words, the left and right rear wheels 4 are turned in the same direction by turning on the rear-wheel traversing cylinder 53 and are directed to the side. An example of the rear wheel rotating device 40 configured to rotate the pair of left and right rear wheels 4 around the vertical axis 49 is configured by the above 51 to 59 and the like.

The operation of the above embodiment will be described below. The solid lines in FIG. 1, FIG. 2 and FIG.
Indicates a straight traveling in normal traveling. At this time, the left and right front wheels 3 and the left and right rear wheels 4 are oriented in the front-rear direction. Such a forklift 1 can travel when an operator sitting on the seat 15 of the driver's seat 5 operates the handle 16.

By operating the lift lever to operate the lift cylinder 11, the lift bracket 12
The fork 13 can be moved up and down along the mast 6 through the like, and the intended fork operation can be performed. The mast 6 can be rotated (tilted) around the connecting shaft 7 by operating the tilt lever 8 by operating the tilt lever, and thus the fork 1 can be rotated via the lift bracket 12 or the like.
3 can be changed.

During the above-mentioned running movement, the steering wheel 16 is turned in accordance with the operation of the steering wheel 16. That is, for example, handle 1
By turning 6 to the left, the turning cylinder 51 is operated to the left by the orbit roll 58 as shown in FIG. 5A, and the holding frame 52 is integrally moved to the left. At this time, the two rear wheel traversing cylinders 53 are in a non-operating position at a predetermined contraction limit and serve as a link.

Therefore, the movement of the holding frame 52 to the left is transmitted to the arm 54 via the rear wheel traversing cylinder 53 and the link 55, thereby moving the pivoting member 45 to the longitudinal axis 4.
9 and turn left with the rear wheel 4 turned. At the time of normal turning in response to the operation of the steering wheel 16, one side of the rear wheel traverse cylinder 53 is pulled, so that a check valve is arranged in the circuit to suppress leaks, It is configured to periodically apply pressure to 53.

As shown in FIG. 5B, when the diverting cylinder 51 is operated to the left to the limit,
The left and right rear wheels 4 can be turned in a reverse U-shape, thereby enabling turning on the spot. When switching from such normal running to traversing running, first, the turning cylinder 51
Is a neutral (straight) position shown in FIG. In this state, for example, a traverse mode switch (not shown) of a lever type is operated, and the front wheel turning device 30 and the rear wheel turning device 50 are operated.
And actuate.

That is, in the front wheel rotating device 30, the front wheel traversing cylinder 31 is actuated by tilting the lever, and the turning member 24 is moved through the link 33 and the like to the vertical axis 27.
And the front wheel 3 is turned 90 degrees relative to the vehicle body 2 as shown in the imaginary lines in FIGS. 1 and 2 and FIG. ). Here the front wheel 3
Are integrated with the hydraulic motor 21 so that the 90-degree turning can be easily and smoothly performed.
Since the front wheel 3 is located just above the front wheel 3, the front wheel 3 and the like can be made compact and can turn 90 degrees.

In the rear wheel turning device 50, the control valve 59 extends the two rear wheel traversing cylinders 53, and the projecting motion of the piston rod 53c is transmitted to the arm body 54 via the link 55, so that the turning member 45 is rotated. Is rotated about a vertical axis 49, and the rear wheel 4 is moved relative to the vehicle body 2 as shown in phantom lines in FIGS. 1 and 3 and in FIGS. 5 (c) and 6 (b). 90 degrees (directly to the side).

When the front wheels 3 and the rear wheels 4 are turned in this way, that is, when the front wheels 3 and the rear wheels 4 are turned right beside the sensor, the indicator lamp is turned on. This enables a traversing mode. Therefore, by supplying the hydraulic pressure from the pair of pumps 41 driven by the engine 40 to the corresponding hydraulic motor 21 through the pipe 42 by the forward / reverse control in the driver's seat 5, the front wheels 3 are rotated in the forward and reverse directions. Drive, so that the forklift 1 can be traversed left and right. At that time, the pair of left and right rear wheels 4 are rotated following.

By being able to perform traversing in this way,
For example, a long object can be easily transported via the fork 13. Next, another embodiment of the present invention will be described with reference to FIGS.
1 will be described. The front-wheel traversing cylinder 31 and the rear-wheel traversing cylinder 53 are arranged in parallel with a common traversing control valve 60, and are connected via solenoid-type open / close valves 61, 62, respectively. Here, the opening / closing valves 61 and 62 are configured such that the rear wheel side opening / closing valve 62 is first opened by traversing operation, and the rear wheel traversing cylinder 53 is operated to traverse by operating the traversing control valve 60. I have.

The rear-wheel traversing cylinder 53 has a rear-wheel-side sensor 6 for detecting the completion of the lateral movement of the rear wheel 4.
3 provided by the detection of the rear wheel side sensor 63,
The rear wheel side opening / closing valve 62 is closed and the front wheel side opening / closing valve 61 is opened. Thereby, the front wheel traversing cylinder 31 can be operated to the traversing side by operating the traversing control valve 60.
The front wheel traversing cylinder 31 includes a front wheel 3
Is provided with a front wheel-side sensor 64 for detecting the completion of the lateral orientation of the vehicle.

In this alternative embodiment, when the traversing mode switch is operated to switch from normal traveling to traversing traveling, only the rear wheel side opening / closing valve 62 is first opened as shown in FIG. By operating the traversing control valve 60, the rear wheel traversing cylinder 5 is operated.
3 is extended by the pressure supply to the extension action chamber. Then, the projecting movement of the pinton rod 53c causes the link 5 to move.
5, the turning member 45 is turned around the longitudinal axis 49, and the rear wheel 4 is turned 90 degrees with respect to the vehicle body 2 (turns rightward). Is done.

When the turning of the rear wheel 4 is completed, the completion is detected by the rear wheel sensor 63, and the detection signal indicates that the rear wheel opening / closing valve 62 is provided as shown in FIG.
Is closed and the front wheel side opening / closing valve 61 is opened. Therefore, by operating the traversing control valve 60, the front wheel traversing cylinder 31 is extended by applying pressure to the extension action chamber. Then, the protruding movement of the pinton rod 31b is transmitted to the vertical axis 34 via the link 33, and the turning member 24 is rotated around the vertical axis 27, so that the front wheel 3 is turned 90 degrees with respect to the vehicle body 2. (Directly to the side).

When the turning of the front wheels 3 is completed, the completion is detected by the front wheel side sensor 64, and the detection signal turns on the indicator lamp, thereby enabling the traversing mode. Therefore, by driving the front wheels 3 in the forward and reverse directions via the hydraulic motor 21, the forklift 1 can be traversed right and left. Since such transverse travel front wheel off valve 61 when doing is in work dynamic state, by operating the transverse control valve 60 appropriately, the range specified front wheel transverse cylinder 31 (FIG. 11 As shown by the solid line or the virtual line, the vehicle can be moved only by the angle of the front wheel 3 (approximately ± 5 °), so that the position, the turning, the correction, and the like during the traversing can be performed.
At that time, the front wheel side sensor 64 is configured to output an operating range signal for correction.

In the above-described another embodiment, the control for switching from the normal traveling to the traversing traveling is performed by operating the common traversing control valve 60 to operate the rear-wheel traversing cylinder 53 and then the front-wheel traversing. Cylinder 31
, The traverse control can be smoothly performed by continuously operating the front-wheel traversing cylinder 31 by operating the traversing control valve 60.

In each of the above embodiments, a two-pump two-motor type hydraulic drive system is used as the drive type of the forklift 1, but this is achieved by using a one-pump two-motor type hydraulic drive system. Is also good. In each of the above-described embodiments, the state adopted in the ordinary forklift 1 is shown, but this can be similarly applied to a side forklift and the like.

[0038]

According to the first aspect of the present invention, 4
Despite being a wheel type, turning during normal running and traversing can be reliably performed without complicated electric control. Further, according to the second aspect of the present invention, the switching control from the normal traveling to the traversing traveling can be always smoothly performed while having a simple and inexpensive configuration for operating the common traversing control valve. Subsequently, the traverse control can be smoothly performed by operating the traverse control valve.

[Brief description of the drawings]

FIG. 1 shows an example of an embodiment of the present invention, and is a side view of a forklift having a traversing system during normal traveling.

FIG. 2 is a partially cutaway front view of a front wheel portion of the forklift having the traversing system.

FIG. 3 is a partially cutaway front view of a rear wheel portion of the forklift having the traversing system.

FIG. 4 is a partially cutaway plan view of a rear wheel portion of the forklift having the traversing system.

FIGS. 5A and 5B are explanatory diagrams of an operation of a rear wheel portion of the forklift having the traversing system, wherein FIG. 5A illustrates a turning operation, FIG. 5B illustrates a turning operation on the spot, and FIG.

FIGS. 6A and 6B are schematic plan views of a forklift having the traversing system, wherein FIG. 6A shows a normal traveling state, and FIG.

FIG. 7 is a schematic plan view of a forklift having the traversing system.

FIG. 8 is a schematic plan view showing another embodiment of the present invention, in which a forklift having a traversing system travels normally.

FIG. 9 is a schematic plan view of the forklift having the traversing system when turning a rear wheel.

FIG. 10 is a schematic plan view of a forklift having the traversing system when turning a front wheel.

FIG. 11 is a schematic plan view of the forklift having the traversing system during traversing travel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Forklift 2 Body 3 Front wheel (drive wheel) 4 Rear wheel (redirect wheel) 5 Driver's seat 6 Mast 11 Lift cylinder 13 Fork 15 Seat 16 Handle 21 Hydraulic motor (travel drive device) 22 Rotating flange (drive shaft) 24 Turning Member 27 Longitudinal axis 30 Front wheel rotating device 31 Front wheel traversing cylinder 33 Link 35 Arm 36 Link body 40 Engine 41 Pump 45 Revolving member 49 Vertical axis center 50 Rear wheel rotating device 51 Diversion cylinder 52 Holding frame 53 Rear wheel Traversing cylinder 54 Arm body 55 Link 58 Orbit roll 59 Control valve 60 Traversing control valve 61 Front wheel side opening / closing valve 62 Rear wheel side opening / closing valve 63 Rear wheel side sensor 64 Front wheel side sensor

Claims (2)

(57) [Claims] 1. A pair of left and right front wheels and a pair of left and right rear wheels are provided on a vehicle body so as to be able to turn 90 degrees, respectively, and the pair of left and right front wheels are respectively linked to a drive shaft on a traveling drive device side. The two traveling driving devices are connected so as to be rotatable around the longitudinal axis with respect to the vehicle body, and a front wheel rotating device for performing the rotation is provided. On the other hand, a rear wheel turning device is provided to be rotatable around the vertical axis and performs turning. The rear wheel turning device has a turning cylinder and a rear wheel traversing cylinder. The conversion cylinder has its body mounted on the vehicle body side.
And the piston rod is
Side, and the protruding ends of the piston rod
A pair of left and right rear wheel traverse
While the body of the cylinder is attached,
The rear wheels protrude outward in the vehicle width direction, and the rear wheels
Is attached connected to the pivot member relatively rotatably, the rear wheel transverse cylinder is predetermined Rutotomoni, during operation of換向cylinder rotates the rear wheels to each other when換向cylinder is neutral like A forklift with a traversing system characterized by a non-operational posture. 2. The front-wheel turning device has a front-wheel traversing cylinder, and the front-wheel traversing cylinder and the rear-wheel traversing cylinder are connected in parallel to a common traversing control valve via open / close valves, respectively. The traversing operation opens the rear-wheel opening / closing valve, the traversing control valve operates the rear-wheel traversing cylinder to the traversing side, and detects the completion of the rear wheels in the lateral direction. And the front-wheel open / close valve
Forklift having a transverse system according to claim 1, characterized in that it is configured to create moving the.