JP2000351592A - Forklift with traversing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a four wheel type forklift with a traversing system which can steer at the usual running time and traversing time and turn on the spot. SOLUTION: This forklift is provided with a drive wheel turning means for turning a drive wheel around the vertical axis center 36 against a car body side and a steering wheel turning means 60, consisting of a cylinder 61 for steering and link mechanisms 67A, 67B, for turning a steering wheel around the vertical axis center 59. The cylinder 61 for steering is composed of a cylinder main body 62 and a pair of piston rods 64A, 64B projecting to the outside while connecting to a pair of pistons 63A, 63B. In the cylinder 61 for steering, right/left operation is carried out by an orbit roll 75 and both pistons 63A, 63B can be operated separately by operating control valves 78A, 78B.

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 driving wheels and the turning 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 normal running and the turning in the sideways direction when 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 that is capable of turning during normal running and traversing and turning on the spot while being of a wheeled type.

[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 pair of left and right driving wheels and a pair of right and left turning wheels on a vehicle body. Each is provided to be able to turn 90 degrees,
Both drive wheels are provided rotatably about the vertical axis with respect to the vehicle body side, and drive wheel rotating means for performing rotation are provided, and both replacement wheels are provided with a vertical axis center with respect to the vehicle body side. A turning wheel turning means is provided so as to be rotatable around and is provided for turning. The turning wheel turning means is provided by a turning cylinder and a turning wheel by expansion and contraction movement of the turning cylinder. The turning cylinder comprises a left-right cylinder body, a pair of pistons disposed in the cylinder body, and a pair of pistons connected to these pistons, and protruding outward in the left-right direction. The turning cylinder is operated by a steering wheel to perform left and right operations by an orbit roll, and by operating respective control valves, both pistons are operated. It is obtained by said being configured to be operated separately.

Therefore, according to the first aspect of the present invention, the right and left driving wheels and the right and left turning wheels are oriented in the front-rear direction during normal running. At this time, the inner end portions of the piston rods are in contact with each other, and the left and right pistons are equally positioned on the left and right. By operating the steering wheel during normal running movement, both piston rods are moved integrally (simultaneously) by the control flow from the orbit roll, and this movement is
The transmission is transmitted to the diverting wheel side via the link mechanism, so that the diverting wheel can be diverted around the longitudinal axis.

[0007] When the in-situ turning mode is selected, the turning cylinder is operated to the left and right so that both pistons reach the outer ends, respectively, whereby the right and left turning wheels are converted into a C-shape. The left and right drive wheels can also be turned in a C-shape by operating the drive wheel rotating means,
A turn in place may be possible. The setting to the in-place turning mode can be performed regardless of the operation position of the operation handle.

When switching from normal traveling to traversing traveling, for example, a lever type traversing mode switch is operated,
The driving wheel turning means and the turning wheel turning means are operated. In other words, the drive wheel rotating means is operated to rotate the drive wheel around the vertical axis, thereby turning the vehicle 90 degrees (directly to the side) with respect to the vehicle body. In the diverting wheel rotating means, both piston rods are extended and contracted to a designated position by a control flow from each control valve, and the diverting wheels are turned into a 90-degree shape with respect to the vehicle body via a link mechanism. (Turn right beside). Such setting to the traversing mode can be performed regardless of the operation position of the operation handle.

After the turning wheels and the driving wheels are turned right and left in this way, by driving the driving wheels in the forward and reverse directions, the forklift can be moved laterally in the left and right directions. At that time, the pair of left and right diverting wheels are rotated following. When the vehicle is traversing, the steering wheel is operated in the same manner as in normal operation, and both piston rods are moved left and right within the allowable range by the control flow from the control valve, so that the position, traverse, Correction can be performed.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below.
A description will be given, based on the drawings, of a state adopted in a side forklift having two positions of turning in place and traversing.
In the following, the left-right direction refers to the vehicle width direction, and the front-rear direction refers to the vehicle length direction.

1 to 8, a side forklift 1 having a traversing system is provided with a pair of right and left turning wheels 3A and 3B at a front portion of a vehicle body 2 and a pair of right and left driving wheels 4A and 4A at a rear portion. 4B are provided. The body 2
On the upper side, a pair of front and rear guide rails 5 is provided, and a movable body 6 is provided between the guide rails 5.
A pair of front and rear masts 7 are erected from the end of the movable body 6.

A pair of left and right guide rollers 8 are provided before and after the movable body 6 and the mast 7, respectively. The guide rollers 8 are fitted to and guided by the guide rails 5, so that the movable bodies 6 and The mast 7 is configured to be reciprocally movable in the left-right direction. Lifting body 9 guided by both masts 7
The lifting body 9 is provided with a fork 10 facing in the left-right direction. The elevating body 9 is moved up and down by a lift cylinder 11.

A reach device 13 for protruding the fork 10 in the left-right direction is provided. The reach device 13 includes a pair of support rods 14 erected from the vehicle body 1 side,
A support pin 15 provided between the upper ends of the support rods 14 in the front-rear direction, an operating cylinder 17 having a main body connected to the support pin 15 and a piston rod connected to the mast 7 via a connection pin 16, etc. It consists of.

An operating section 20 is provided at the front of the vehicle body 2 and on one side, and the operating section 20 is provided with a driver's seat 21, an operating handle 22, a group of operating levers 23 and the like. Downward cylinders 25 are provided at a plurality of lower portions of the vehicle body 2, that is, at two front and rear portions on the protruding side of the fork 10, and the lower ends of the piston rods of these cylinders 25 are in contact with and separated from the floor. An outrigger 26 for free fall prevention is provided.

A pair of left and right turning wheels 3A and 3B and a pair of left and right driving wheels 4A and 4B are provided so as to be able to turn 90 degrees relative to the vehicle body 2 (turn right beside). That is, the pair of left and right drive wheels 4A, 4B is mounted directly on the rotary flange (drive shaft) 31 of the hydraulic motor (traveling drive device) 30 via the connecting member 32, so that the rim thereof is connected to the hydraulic motor 30 side. It is linked and linked.

The mount of the hydraulic motor 30 is inverted L
The horizontal plate portion of the turning member 33 is attached to the vertical plate portion of the
4 and the longitudinal axis 35, the longitudinal axis 36 with respect to the vehicle body 2 side.
Are provided so as to be rotatable around. At that time, the vertical axis 3
6 is configured to be located directly above the drive wheels 4A and 4B.

The hydraulic motor 30, that is, the swing member 3
3 is provided with a driving wheel rotating means 40 for rotating the driving wheel 3.
The driving wheel rotating means 40 has a driving wheel traversing cylinder 41. The driving wheel traversing cylinder 41 has a cylinder body 42 mounted on the vehicle body 2 side via a vertical pin 44 so as to be swingable. Reference numeral 43 is connected to a link 45 provided continuously from one of the turning members 33 so as to be relatively rotatable via a vertical connecting pin 46. The arms 47 fixed to the left and right vertical axes 35 are connected to each other via a link body 48 and a connecting pin 49 so as to be relatively rotatable.

Therefore, the drive wheel traversing cylinder 41
By turning the turning member 33 through the link 45 by the operation of the above, the one drive wheel 4B is turned around the vertical axis 36 and turned to the side by the hydraulic motor 30 or the like. The drive wheel 4A on the other side can be turned around the longitudinal axis 36 and directed right beside via the link 47 or the link body 48 or the like. That is, according to the drive wheel rotating means 40, the left and right drive wheels 4A and 4B are turned in opposite directions by the operation of the common drive wheel traverse cylinder 41, and are directed to the side. By the above 41 to 49 etc.
An example of the driving wheel rotating means 40 is configured.

On the vehicle body 2 side, an engine 50 and a pair of pumps 51 driven by the engine 50 are provided. Then, the pumps 51 correspond to one hydraulic motor 30, that is, a two-pump two-motor type hydraulic drive system (HST system).
Thus, the corresponding pump 51 and the hydraulic motor 30 are communicated via a pipe (eg, a hydraulic hose) 52.

A pair of left and right turning wheels 3A and 3B are provided with their rims rotatably attached to a vertical plate portion of a turning member 55 via a horizontal axle 56 or the like. The plate part has a bearing 57 and a vertical axis 5
8 and is rotatably provided around the longitudinal axis 59 with respect to the vehicle body 2 side. A pair of right and left turning wheels 3A, 3B
Is provided around the vertical axis 59. The diverting wheel rotating means 60 includes a diverting cylinder 61 and link mechanisms 67A and 67 for rotating the diverting wheels 3A and 3B by the expansion and contraction of the diverting cylinder 61.
B and the like.

The turning cylinder 61 has a left-right cylinder body 62, a pair of pistons 63A, 63B disposed inside the cylinder body 62, and is connected to the pistons 63A, 63B to be outward in the left-right direction. It is constituted by a pair of protruding piston rods 64A, 64B and the like. At that time, the cylinder main body 62 is attached to the vehicle body 2 with its length direction being the left-right direction.

The inner end portions 64a, 64b of the piston rods 64A, 64B penetrate through the pistons 63A, 63B and protrude inward, and are configured to be able to abut each other. As a result, outer working chambers 65A and 65B are formed on the outer surfaces of the pistons 63A and 63B, respectively, and a common inner working chamber 66 is formed between the opposing surfaces of the pistons 63A and 63B. The left and right widths (lengths) of the inner working chamber 66 are formed to be the shortest width 66e when the inner end portions 64a and 64b are brought into contact with each other.
When 3B reaches the outer end, the longest width 66E is formed.

The link mechanisms 67A and 67B are
Arm bodies 68A, 68B connected from both longitudinal axes 58 side
And connecting pins 69A,
A link 70 rotatably connected via 69B.
A, 70B and the like.
The free end of 70B and the outer ends of the pistons 63A and 63B are relatively rotatably connected via connecting pins 71A and 71B.

The turning cylinder 61 is configured to perform a left-right operation by an orbit roll (fully hydraulic power steering) 75 by turning the operation handle 22. That is, the oil passage from the orbit roll 75 is connected to the outer working chambers 65A and 65B. In addition, check valves (double check valves) 76A, 76B are provided in an oil passage from the orbit roll 75 to the turning cylinder 61.
Is interposed.

Further, the turning cylinder 61 is configured such that both pistons 63A and 63B can be operated individually by operating respective control valves 78A and 78B. That is, the oil passages from the control valves 78A and 78B are connected to the outer working chamber 65, respectively.
A, 65B and the inner working chamber 66 are connected. Here, as the control valves 78A and 78B, an electromagnetic proportional control type or the like is employed.

For example, sensors (turning amount detecting means) 73A for detecting the turning amount of the turning wheels 3A and 3B by detecting the turning amount of the vertical axis 58 are provided in the portion of the vertical axis 58.
73B are provided. Accordingly, by turning the turning cylinder 61 to rotate the longitudinal axis 58 through the links 70A and 70B and the arm bodies 68A and 68B by the extension operation of the turning cylinder 61, the turning wheels 3A and 3B are turned through the turning member 55 and the like. It can be turned around the vertical axis center 59 and pointed sideways. That is, the left and right diverting wheels 3A and 3B are configured to be turned in opposite directions to each other by the extension operation of the diverting cylinder 61 and directed to the side. An example of the turning wheel turning means 60 for turning the pair of left and right turning wheels 3A, 3B around the longitudinal axis 59 is constituted by the above-described 61 to 78A, 78B and the like.

The operation of the above embodiment will be described below. Solid lines in FIGS. 1 to 5, 6 and 7, and FIG. 8A show a pair of left and right turning wheels 3A and 3B and a pair of right and left driving wheels 4A and 4B in the front-rear direction.
This indicates a straight traveling in normal traveling. At this time,
Inner end portions 64a, 64 of piston rods 64A, 64B
b are in contact with each other, the inner working chamber 66 is formed with a shortest width 66e, and the left and right outer working chambers 65A and 65B are formed with a uniform left and right width (length). In such a side forklift 1, a worker sitting on a driver's seat 21 of a driving unit 20 can travel by operating an operation handle 22 or the like.

For example, while the side forklift 1 is stopped, the movable cylinder 6 and the mast 7 are moved via the guide roller 8 by contracting the operating cylinder 17 as shown by the solid line in FIG. The fork 10 can be retracted by moving the fork 10 sideways. At this time, as shown by the solid line in FIG. 4, each outrigger 26 is raised by the contraction movement of the two cylinders 25 and is separated from the floor, so that the vehicle body 1 can run.

The operating cylinder 1 of the reach device 13
7, the movable body 6 and the mast 7 are laterally moved via the guide rollers 8 to the side away from the reach device 13, and as shown by the imaginary line in FIG. Can be protruded. At that time, as shown by the imaginary line in FIG. 4, each outrigger 26 is lowered by the extension movement of the two cylinders 25 and is brought into contact with the floor, thereby preventing the vehicle body 2 from tipping over. .

By appropriately incorporating the lifting and lowering movement of the lifting and lowering body 9 by the lift cylinder 11, that is, the lifting and lowering movement of the fork 10, loading and unloading of the intended goods can be performed. At the time of the above-described running motion, the direction is changed according to the operation of the operation handle 22. That is, for example, by turning the operation handle 22 to the right side, the turning cylinder 61 is operated by the control flow from the orbit roll 75, and FIG.
As shown in (2), both piston rods 64A, 64B are integrally and simultaneously moved to the right so that the left outer working chamber 65A is enlarged and the right outer working chamber 65B is reduced.

The two piston rods 64A, 64
The movement of B to the right is transmitted to the longitudinal axis 58 via the link mechanisms 67A and 67B, and thus the pivot member 55 is moved to the longitudinal axis 59.
, And the turning wheels 3A and 3B can turn to turn right. In addition, a left turn can be performed by performing the reverse operation in the same manner. When the in-situ turning mode is selected, as shown in FIG. 9 (b), the turning cylinder 61 is actuated to the left and right, ie, both pistons 63A and 63B.
Reaches the outer end, the inner working chamber 66 is formed to have the longest width 66E, whereby the left and right diverting wheels 3A and 3B are diverted in a C-shape. Before or after this, the drive wheel rotating means 40 is operated, and the left and right drive wheels 4A, 4B are also turned in a C-shape. This may enable on-the-spot turning, in which case the on-the-spot turning mode is set by the operation handle 22
It can be performed regardless of the operation position of.

When switching from the normal running as described above to the traversing running, the drive wheel turning means 40 and the turning wheel turning means 60 are operated by operating, for example, a lever type traversing mode switch (not shown). Let it. That is, in the driving wheel rotating means 40, the driving wheel traversing cylinder 41 is operated by inclining the lever, and the turning member 33 on one side is rotated about the vertical axis 36 via the link 45. By rotating the turning member 33 on the other side around the longitudinal axis 36 via the arm 47, the link body 48, and the like, the driving wheels are rotated as shown in the imaginary line in FIG. 6 and FIG. 4A and 4B are turned 90 degrees (directly to the side) with respect to the vehicle body 2.

Here, since the drive wheels 4A and 4B are each integrated with the hydraulic motor 30, the turning can be performed easily and smoothly, and the longitudinal axis 36 is located just above the drive wheels 4A and 4B. Therefore, the drive wheels 4A, 4B and the like can be made compact to perform 90-degree turning. In the turning wheel turning means 60, both piston rods 64A, 64B are extended and contracted to the designated positions by the control flow from the respective control valves 78A, 78B, and are turned via the link mechanisms 67A, 67B. Is rotated about the vertical axis 59, and the turning wheels 3A and 3B are moved relative to the vehicle body 2 as shown in a virtual line in FIG. 7, (b) in FIG. 8, and (c) in FIG. 90 degrees (directly to the side).

The position designated at that time is the sensor 73
It is controlled by detecting A, 73B and the like. The setting to the traversing mode can be performed regardless of the operation position of the operation handle 22. Thus, the turning wheels 3A, 3
B and the drive wheels 4A and 4B are turned, that is, the turning of the turning wheels 3A and 3B and the drive wheels 4A and 4B are turned to the side. This allows a traversing mode.

Accordingly, the hydraulic pressure from the pair of pumps 51 driven by the engine 50 is supplied to the corresponding hydraulic motor 30 by the forward / reverse control in the driver's seat 21 to the pipe 5.
2, the drive wheels 4A and 4B can be driven in the normal and reverse directions, so that the side forklift 1 can travel sideways. At this time, the pair of left and right turning wheels 3A and 3B are rotated by following.

When the vehicle is traveling in such a transverse direction, as shown in FIG. 9C, since the outer working chambers 65A and 65B each have a small width, this extra space is used. Thus, the position, turn, correction, and the like during traversing can be performed. That is, it is possible to operate the operating handle 22 in the same manner as in the normal case, and to simultaneously move the two piston rods 64A and 64B left and right by the control flow from the orbit roll 75. And so on.

Of the various operations as described above, the in-situ turning mode and the traversing mode are released by returning the piston rods 64A, 64A, 44A to the designated position (neutral position or a position matching the sensor of the operation handle 22). 64B, and finally pressurize the outer working chambers 65A, 65B to bring the inner end portions 64a, 64b into contact with each other.

In order to prevent the piston rods 64A, 64B from being separated from each other due to a valve leak during normal running, a check valve may be provided or the outer working chamber 6 may be periodically arranged.
5A and 65B are pressed and brought into contact with each other. When electric control is added to the above-described embodiment, the following I to
The advantages shown in FIG.

I. As shown in FIG. 8 (a), the turning from the straight traveling is performed by changing the driving wheels 4A, 4B according to the turning angles of the turning wheels 3A, 3B, as shown in FIG. A horizontal right-turning posture in the shape of a letter and a horizontal left turning posture in the shape of an inverted C as shown in FIG. 10B can be achieved, and smoother turning can be performed. II. When the piston rods 64A and 64B return to the designated positions (for example, the neutral position) at the time of canceling the in-place turning mode or the traversing mode, the position with the handle knob does not match. By installing and returning it to a position that matches the position of the operation handle 22, the knob can be prevented from shifting. Further, if this system is used at the time of turning of the normal running, the knob shift control of the orbit roll 75 can be performed.

III. When the two piston rods 64A, 64B are separated from each other due to valve leak, it can be controlled so that the two piston rods 64A, 64B automatically come into contact with each other. IV. Side forklift 1 does not move while setting to traverse mode.
The functions such as that the mode cannot be switched unless the operation is stopped can be easily realized, so that there is almost no restriction on persons.

V. Other cargo handling controls can also be performed. In the above-described embodiment, for example, a free-running side forklift 1 used for transporting heavy objects is shown. However, for example, a pickup coil provided on a vehicle body side is provided on a floor-side induction wire. A side forklift or the like that can travel on a given automated transfer line by catching electromagnetic waves may be used.

In each of the above-described embodiments, the state adopted for the side forklift 1 is shown, but this can also be applied to a normal forklift or the like.

[0043]

According to the first aspect of the present invention, 4
It is a wheel-wheel type and uses a single turning cylinder. The piston rod of this turning cylinder is divided into left and right parts, and it is simple to control. Direction and on-the-spot turning can always be performed smoothly and reliably.

[Brief description of the drawings]

FIG. 1 shows an example of an embodiment of the present invention, and is a partially cutaway plan view of a turning-wheel rotating unit of a forklift having a traversing system.

FIG. 2 is a perspective view of a forklift having the traversing system.

FIG. 3 is a vertical sectional front view of the forklift having the traversing system.

FIG. 4 is a partially cutaway side view of the forklift having the traversing system.

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

FIG. 6 is a partially cutaway front view of a drive wheel portion of the forklift having the traversing system.

FIG. 7 is a partially cutaway front view of a turning wheel portion of the forklift having the traversing system.

8A and 8B are schematic plan views of a forklift having the traversing system, wherein FIG. 8A illustrates a straight traveling state and FIG. 8B illustrates a traversing state.

9A and 9B are explanatory diagrams of the operation of a turning wheel portion of a forklift having the traversing system, wherein FIG. 9A shows a normal turning, FIG. 9B shows a spot turning, and FIG.

FIGS. 10A and 10B are explanatory diagrams of electric control of a forklift having the traversing system, wherein FIG. 10A illustrates a traversing right turn and FIG. 10B illustrates a traversing left turn.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Side forklift 2 Body 3A Diverting wheel 3B Diverting wheel 4A Driving wheel 4B Driving wheel 6 Movable body 7 Mast 10 Fork 13 Reach device 20 Operating part 22 Operating handle 30 Hydraulic motor (traveling driving device) 33 Revolving member 36 Vertical axis Reference Signs List 40 drive wheel turning means 41 drive wheel traversing cylinder 45 link 47 arm 48 link body 50 engine 51 pump 55 turning member 59 longitudinal axis 60 turning wheel turning means 61 turning cylinder 62 cylinder body 63A piston 63B piston 64A piston rod 64a Inner end 64B Piston rod 64b Inner end 65A Outer working chamber 65B Outer working chamber 66 Inner working chamber 67A Link mechanism 67B Link mechanism 68A Arm body 68B Arm body 70A Link 70B Link 73A Sensor (rotation Amount detecting means) 73B Sensor (rotation amount detecting means) 75 Orbit roll 76A Check valve (double check valve) 76B Check valve (double check valve) 78A Control valve 78B Control valve

Claims (1)

[Claims] 1. A pair of left and right driving wheels and a pair of left and right turning wheels are provided on a vehicle body so as to be able to turn 90 degrees, respectively, and both driving wheels rotate around a vertical axis with respect to the vehicle body side. A drive wheel turning means is provided for freely turning, and both turning wheels are provided to be rotatable around the longitudinal axis with respect to the vehicle body side, and a turning direction for turning is provided. Wheel turning means is provided, the turning wheel turning means comprises a turning cylinder, and a link mechanism for turning the turning wheel by expansion and contraction of the turning cylinder, and the turning cylinder is A cylinder body in the left-right direction, a pair of pistons disposed in the cylinder body, and a pair of piston rods connected to these pistons and protruding outward in the left-right direction. Orbit by operating the handle A forklift with a traversing system, characterized in that both left and right operations are performed by trawl and each control valve is operated so that both pistons can be operated individually.