JP3121809B1 - Forklift with traversing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a forklift truck with a traversing system having a simplified rear wheel turning means, enabling direction change during normal run and traversing run in spite of a four wheel type. SOLUTION: Front wheels 3 and rear wheels 4 are provided in a 90 degree direction changeable manner. A running driving means 21 connected in association with the front wheels 3 is provided around a vertical axis center 27 so as to be rotationally movable and a front wheel turning means 30 is also provided. A rear wheel turning means 50 for turning the rear wheels 4 around a vertical axis center 49 has a direction changing cylinder 51 and a rear wheel traversing cylinder 53 integrated with bodies 51a, 53a, respectively. The direction changing cylinder 51 formed with a piston rod 51c fixed to a body 2 and a body 51a to be movable. The rear wheel traversing cylinder 53 of a right and left pair for turning of the rear wheels 4 when the direction changing cylinder 51 is in a neutral condition is in given non-operative attitude during operation of the direction changing cylinder 51.

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 which is capable of turning during normal running and traversing while being a wheel-wheel type, and which can simplify rear wheel turning means.

[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 the traveling drive unit in an interlocking manner, and both traveling drive units rotate around the vertical axis with respect to the vehicle body side. A front wheel rotating means is provided for freely rotating, and a pair of right and left rear wheels are provided rotatably around a vertical axis with respect to the vehicle body side and rotate. Rear wheel rotating means is provided,
This rear wheel turning means has a turning cylinder and a rear wheel traversing cylinder whose main bodies are integrated, and the turning cylinder has a piston rod fixed to the vehicle body side and the main body is movable. The rear wheel traverse cylinder is provided in a pair of left and right so that the rear wheels can be individually rotated when the turning cylinder is in a neutral state, and has a predetermined non-operating posture when the turning cylinder is operated. It is characterized by the following.

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, turn the steering wheel to the left and right to activate the turning cylinder with the orbit roll, and when moving the main body of both rear wheel traverse cylinders together with its body, both rear wheel traverse cylinders are specified In the non-operational position of
In response to steering of the steering wheel, the vehicle can turn left and right by turning the rear wheel. In addition, when the body of the turning cylinder is operated to the limit, the left and right rear wheels can be turned in an inverted 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 turning means and the rear wheel turning means are operated. That is, the front wheel turning means is operated, and the front wheel is turned around the vertical axis so as to be turned 90 degrees (right sideways) with respect to the vehicle body. Here, since the front wheels are each integrated with the traveling drive means, the 90-degree turning can be easily and smoothly performed.

Further, the rear wheel rotating means is operated to rotate the rear wheel about the vertical axis so as to be turned 90 degrees (right sideways) with respect to the vehicle body. At this time, the rear wheel turning means operates the rear wheel traversing cylinder in a state where the turning cylinder is in the neutral (straight-running) position, so that the 90 ° turning of the rear wheel can be easily performed. It can be done smoothly. After the front wheels and the rear wheels have been turned right and left in this way, the forklift can be traversed right and left by driving the front wheels in the forward and reverse directions by the traveling drive means. At this time, the pair of left and right rear wheels are rotated following.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below.
The state employed in a normal forklift will be described with reference to the drawings. 1 to 5, 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 and a pair of left and right rear wheels (redirect wheels) at a rear portion. 4 is provided and the body 2
A driver's seat 5 is provided above and in front of the vehicle. A mast 6 that is vertically expandable and contractible is attached to the front end of the vehicle body 2 via a connecting shaft 7 in the vehicle width direction so as to be rotatable in the front-rear direction, and a tilt cylinder 8 that rotates back and forth.
Is provided between the vehicle body 2 and the mast 6.

The mast 6 includes 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 (right sideways) with respect to the vehicle body 2. That is, the rim 3A of the pair of left and right front wheels 3 is directly attached to the rotating flange (drive shaft) 22 of the hydraulic motor (an example of travel driving means) 21 via the connecting member 23, so that the hydraulic motor 21 It is linked to the 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 turning means 30 for turning. The front wheel turning means 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 31b. 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 through the link 33 by the operation of the front wheel traverse cylinder 31, the front wheel 3 on one side is turned around the longitudinal axis 27 and turned to the side. At the same time, the front wheel 3 on the other side can be turned around the longitudinal axis 27 and directed sideways via the arm 35 and the link body 36. In other words, according to the front wheel turning means 30, 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. 31 to 37
Thus, an example of the front wheel rotating means 30 is configured.

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 5, a pair of right and left 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. Rear wheel turning means 50 for turning the pair of left and right rear wheels 4 around a vertical axis 49 is provided, and the rear wheel turning means 50 includes 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 arranged in the vehicle width direction, and the piston rod 51c connected to the piston 51b protrudes on both sides in the vehicle width direction. And the piston rod 51
The protruding both ends of c are respectively fixed to the vehicle body 2 via the holding frame 52, so that the main body 51a is configured to be movable in the vehicle width direction.

The rear-wheel traversing cylinders 53 are a pair of left and right, and their main bodies 53a are integrated (connected) to the main body 51a of the turning cylinder 51 via a connecting member 54.
Have been. At this time, these rear wheel traverse cylinders 5
Piston rod 53c connected to the third piston 53b
Are projected outward in the vehicle width direction. The arm body 55 connected from the longitudinal axis 48 and the protruding end of the piston rod 53c are relatively rotatably connected via a link 56, vertical connecting pins 57, 58, and the like. .

According to the rear wheel rotating means 50, the operation of the turning cylinder 51 is performed by the fixed piston rod 51c.
The main body 51a is moved in the vehicle width direction, and the main body 53a of the rear wheel traversing cylinder 53 is moved in the vehicle width direction integrally with the main body 51a of the turning cylinder 51. At this time, a guide body 59 that penetrates the connecting member 54 is provided between the holding frame bodies 52, so that the guide body 59 guides movement of the main bodies 51a and 53a and prevents rotation.

The turning cylinder 51 is operated by turning the handle 16 with an orbit roll (fully hydraulic power steering) 60.
The rear wheel traversing cylinder 53 is a turning cylinder 5
By operating the control valve 61 when 1 is in the neutral state, the rear wheels 4 are separately rotatable and provided in a pair on the left and right sides. It is configured.

Therefore, by operating the rear wheel traversing cylinder 53, the vertical axis 48 is rotated through the link 56, the arm body 55, 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. That is, by the operation of the rear wheel traversing cylinder 53, the left and right rear wheels 4 are configured to turn in the same direction to face each other and to face sideways. An example of the rear wheel rotating means 50 configured to rotate the pair of left and right rear wheels 4 around the vertical axis 49 is constituted by the above 51 to 61 and the like.

The operation of the above embodiment will be described below. 1 (a), solid lines in FIGS. 2, 3 and 4,
FIG. 5 shows a straight traveling state during 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
Means that the worker sitting on the seat 15 of the driver's seat 5
By maneuvering, the vehicle can move.

By operating the lift lever 11 by operating the lift lever, the lift bracket 12 is operated.
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.

In the above-described running movement, the steering wheel 16 is turned in accordance with the operation of the steering wheel 16. That is, for example, handle 1
6 by rotating the orbit roll 6 to the left, as shown in FIG.
At 0, the main body 53a of the rear-wheel traversing cylinder 53 is integrally moved to the left via the connecting member 54. 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, both rear wheel traversing cylinders 53
Is transmitted to the arm body 55 via the link 56, so that the turning member 45 can be turned around the longitudinal axis 49, and the rear wheel 4 can be turned to turn left. 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. 6 (b), when the main body 51a of the turning cylinder 51 is operated to the left to the limit, the left and right rear wheels 4 can be turned in an inverted C-shape. Thus, a turn on the spot can be made possible. In the same manner as described above, for example, by turning the handle 16 to the right,
You can turn right. When switching from such normal running to traversing running, the turning cylinder 51 is first set to the neutral (straight running) position shown in FIG. In this state, for example, a lever-type traversing mode switch (not shown) is operated to operate the front wheel turning means 30 and the rear wheel turning means 50.

That is, in the front wheel rotating means 30, the front wheel traversing cylinder 31 is operated by tilting the lever, and the turning member 24 is moved through the link 33 or the like to the vertical axis 27.
, The front wheel 3 is turned 90 degrees (right sideways) with respect to the vehicle body 2 as shown in FIG. 1 (b) and phantom lines in FIGS. . Here, the front wheel 3
Since each is integrated with the hydraulic motor 21,
Zero-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 to perform 90-degree turning.

In the rear wheel turning means 50, the control valve 61 extends the rear wheel traversing cylinders 53, and the projecting motion of the piston rod 53 c is transmitted to the arm 55 through the link 56, and the turning member 45 is moved. Is rotated about the vertical axis 49, and as a result, FIG.
As shown in FIG. 6 (c) and the imaginary line of FIG. 6, the rear wheel 4 is turned 90 degrees (right sideways) with respect to the vehicle body 2.

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 and left by the sensor, the indicator lamp is turned on. , Which allows 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. In the above-described embodiment, a two-pump two-motor type hydraulic drive system is employed as the drive type of the forklift 1, but a one-pump two-motor type hydraulic drive system may be employed.

In the above-described embodiment, the state adopted in the ordinary forklift 1 is shown, but this can be similarly applied to a side forklift and the like.

[0032]

According to the first aspect of the present invention, 4
Despite being of a wheeled type, turning during normal running and traversing can be reliably performed without complicated electric control. In addition, the rear wheel turning means integrates the body of the turning cylinder and the rear wheel traversing cylinder,
The conversion cylinder has a piston rod fixed to the vehicle body and the main body is movable so that the entire body can be simplified and the movement of the conversion cylinder is accurately reflected on the rear wheel traverse cylinder. The relative position accuracy can be improved.

[Brief description of the drawings]

FIG. 1 shows an example of an embodiment of the present invention, and is a schematic plan view of a forklift having a traversing system, in which (a) shows a normal traveling state and (b) shows a traversing traveling state.

FIG. 2 is a side view of the forklift having the traversing system during normal traveling.

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

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

FIG. 5 is a partially cutaway plan view of a rear wheel portion of the forklift having the traversing system.

FIGS. 6A and 6B are explanatory diagrams of an operation of a rear wheel portion of the forklift having the traversing system, wherein FIG. 6A illustrates a turning operation, FIG. 6B illustrates a turning operation on the spot, and FIG.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Forklift 2 Body 3 Front wheel (drive wheel) 4 Rear wheel (redirect wheel) 5 Driver's seat 11 Lift cylinder 13 Fork 15 Seat 16 Handle 21 Hydraulic motor (travel drive means) 22 Rotary flange (drive shaft) 24 Revolving member 27 Longitudinal axis 30 Front wheel turning means 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 turning means 51 Diversion cylinder 51a Main body 51c Piston rod 52 Holding frame 53 Rear wheel traversing cylinder 53a Main body 54 Connecting material 55 Arm body 56 Link 59 Guide body 60 Orbit roll 61 Control valve

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B66F 9/075 B62D 7/14

Claims (1)

(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 with a drive shaft on a traveling drive means side. The two driving means are connected to each other so as to be rotatable around the longitudinal axis with respect to the vehicle body, and front wheel rotating means for performing rotation are provided. On the other hand, a rear wheel turning means is provided so as to be rotatable around the longitudinal axis and performs turning, and the rear wheel turning means is composed of a turning cylinder and a rear wheel whose body is integrated. A traversing cylinder, wherein the turning cylinder is configured such that a piston rod is fixed to the vehicle body side and a main body is movable, and the rear wheel traversing cylinder is rearward when the turning cylinder is in a neutral state. The wheels can be turned separately and are provided as a pair on the left and right. And a forklift having a traversing system, wherein the forklift takes a predetermined non-operating posture when the turning cylinder is operated.