JPH08282986A - Mast device for cargo handling vehicle - Google Patents

Abstract

PURPOSE: To eliminate obstruction of a field of vision by a chain, by arranging a rotary surface of each chain wheel conformed to a line of sight of a driver seated in a driver's seat of a cargo handling vehicle and tilted at a front spread specific value angle. CONSTITUTION: A chain wheel 9, in both end parts a connecting plate 10 of connecting an upper end of a piston rod 7a of right/left lift cylinders 7, is pivotally supported to outside a car body lateral direction of a bracket 15 suspended toward downward from a lower surface of this connecting plate 10. A rotary surface 9A of each chain wheel 9 is conformed to a line of sight of a driver seated in a driver's seat of a counter balance type forklift to be arranged at a front spread angle α, and when viewed a mast from the sky, also the bracket 15 is tilted to be arranged so as to agree with a line of sight of the driver. In this way, as a result of imaging a chain C overlapped to be longitudinally suspended from the chain wheel 9 in a field of vision of the driver, a front field of vision can be markably improved such as by about halving a region obstructed by the chain as compared with in the past.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mast device for a cargo handling vehicle which can improve the visibility from the driver's seat.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 5, in a cargo handling vehicle having a so-called open mast structure, a lifting mast a,
By arranging the lift cylinders c and c for lifting the lift bracket b and the like behind the left and right mast members, a space is formed between the left and right mast members, and the visibility of a cargo handling tool such as a fork d for handling luggage is improved. It has been improved to improve cargo handling workability and driving operability.

[0003]

The left and right ends of the lift bracket b are connected to one end of a chain e, the other end of which is fixedly attached, and the chain e is also attached.
Is lifted by a chain wheel i axially supported by a connecting plate g that joins the upper ends of the piston rods f and f of the lift cylinders c, thereby raising and lowering the lift bracket b.

However, in such an open mast structure, although the visibility can be improved to some extent by the distribution arrangement of the lift cylinders c, c, the chain e that hangs back and forth around the chain wheel i and hangs down. As a result of the fact that the rotation surface j of the chain wheel i, which pivotally supports the chain e, is arranged substantially parallel to the vertical plane along the center line of the vehicle body, as a result, the driver seat The chains e1 and e that hang forward and backward from the chain wheel i, which do not match the line of sight of the driver who sits forward and looks at the chain wheel.
Both 2 were present in the driver's field of view, obstructing the field of vision.

In particular, since the chains e1 and e2 before and after being hung down and hanging around the chain wheel are constantly moving when the fork d is moved up and down, it is easy to attract the driver's attention and attention during work. There is also a problem such as lowering.

The present invention has been devised in view of the above problems, and in particular, the obstruction of the field of view by the chain for lifting the lift bracket is prevented by the driver's line of sight on the rotating surface of the chain wheel around which the chain is wound. It is an object of the present invention to provide a mast device for a cargo handling vehicle, which can eliminate the obstacle of the field of view by the chain, and can solve the above-mentioned problems, basically by arranging them so as to match.

[0007]

SUMMARY OF THE INVENTION The present invention provides a mast body comprising a pair of left and right fixed masts fixed to both sides of a front portion of a vehicle body, and a pair of left and right elevating masts vertically movable along the fixed masts. A lift bracket that can move up and down along the lifting mast and can be mounted with a cargo handling tool such as a fork is arranged, and, behind the mast body, left and right lift cylinders that lift the lifting mast by raising the piston rod are arranged, Moreover, a chain wheel provided with a chain wheel, one end of which is connected to the lift bracket and the other end of which is immovably fixed, is wound to move the lift bracket up and down at twice the speed of the lifting mast as the piston rod moves up. In the vehicle, the chain wheel is pivotally supported at both ends of a connecting plate that joins upper ends of piston rods of the left and right lift cylinders, and The decor rotation plane inclined in front angle of divergence α by matching the driver's line of sight sitting in the driver's seat of the cargo handling vehicle as a mast assembly of the cargo handling vehicle, characterized in.

The angle α is set in the range of 3 ° to 25 °, and one end of the connecting plate is connected to the hydraulic actuator on the lift bracket side and the other end is connected to the hydraulic pressure supply source on the vehicle body side. It is preferable that the hose pulley around which the communicating hydraulic hose can be wound is freely rotatable and tilted substantially parallel to the chain wheel.

Particularly, when the cargo handling vehicle is a counterbalance type forklift having a driver's seat at a position deviated from the center line of the vehicle body, the tilt angles of the left and right chain cars are changed according to the amount of deviation. Is good.

[0010]

[Function] By arranging the chain wheels so that the rotation surface of each chain vehicle is aligned with the line of sight of the driver sitting in the driver's seat of the cargo handling vehicle and tilted at the angle α of the front spread, The chains that hang down around the chain wheel and hang down appear to overlap each other.As a result, the area in which the chain obstructs the driver's view is significantly reduced compared to before, and the front view is further expanded to improve cargo handling workability. It is possible to improve and prevent deterioration of attention.

Further, in a cargo-handling vehicle having a hose pulley for supporting a hydraulic hose or the like, by arranging the hose pulley in a tilted manner as in the case of the chain wheel, a driver seated in a driver's seat can be provided with a hydraulic hose like a chain. As a result of overlapping each other, it helps to improve the forward visibility.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 to 3, the present invention is a mast including a pair of left and right fixed masts 2 fixed to both sides of a front portion of a vehicle body, and a pair of left and right elevating masts 3 that are vertically movable along the fixed mast 2. A lift bracket 6 which can move up and down along the lifting mast 3 of the body 4 and on which a cargo handling tool 5 such as a fork can be mounted is arranged, and the lifting mast 3 is lifted behind the mast body 4 by raising a piston rod 7a. The counterbalance type forklift F in which the left and right lift cylinders 7 for lifting are arranged is illustrated.

The left and right fixed masts 2 and the lifting masts 3
The upper ends of both are connected by joint members 11 and 12, and a guide shaft 13 extending downward is fixed to the left and right sides of the joint member 12 that joins the lifting mast 3.

The counterbalance type forklift F has a chain C, one end of which is connected to the lift bracket 6 and the other end of which is immovably fixed to the anchor member 14. The chain C is lifted and the lift bracket 6 is lifted. There is provided a chain wheel 9 for moving up and down at a speed twice that of the lifting mast 3.

In the present embodiment, the chain wheel 9 is a vehicle body of a bracket 15 that hangs downward from the lower surface of the connecting plate 10 at both ends of the connecting plate 10 that joins the upper ends of the piston rods 7a of the left and right lift cylinders 7. It is pivoted outward in the width direction. The bracket 15 forms a bulging portion 16 that can be pushed up by coming into contact with the joint material 12 of the elevating mast 3, and the guide shaft 13 is inserted into the bulging portion 16 to insert the guide rod 13 into the piston rod. A guide hole 17 that can guide the ascent is formed.

In this example, the bracket 15 has a tapered cross section whose width is reduced toward the driver's seat when viewed from above the mast.
Such a configuration also helps to improve the front field of view.

Further, the bulging portion 16 of the bracket 15
As is clear from FIG. 4 which is a cross section taken along the line AA of FIG. 1, the upper surface of the is separated from the lower surface of the joint material 12 at the lowermost position of the cargo handling tool 5 without changing the mast height. It is possible to obtain a free lift amount h for raising the cargo handling tool 5 such as a fork.

Next, the rotation surface 9A of each chain wheel 9 is arranged so as to be inclined at a front divergence angle α so as to match the line of sight of the driver seated in the driver seat 8 of the counterbalance type forklift F, In this example, when the mast is viewed from above,
The bracket 15 is also illustrated as being tilted so as to match the line of sight of the driver.

As described above, by arranging the chain wheel 9 so as to substantially coincide with the line of sight of the driver and inclining the chain wheel 9 at the angle of the front divergence, the driver in the driver's seat hangs back and forth from the chain wheel 9. As a result of the chains C1 and C2 overlapping each other, the front field of view can be greatly improved, for example, the area in which the front field of view is obstructed by the chain is reduced to about half that in the conventional case.

The angle α is in the range of 3 ° to 25 °,
More preferably, it is desirable to set it in the range of 5 ° to 22 °. If the angle α is less than 3 °, the forward field of view cannot be improved as compared with the conventional case, and if it exceeds 25 °, the inclination becomes too large and the chains tend to overlap each other and become invisible.

In most counterbalanced forklifts F of this example, as shown in FIG. 3, the driver's seat 8 is provided at a position displaced to the left from the center line of the vehicle body in a top view. Therefore, it is preferable to change the tilt angles of the left and right chain wheels 9 according to the deviation amount L to match the line of sight of the driver sitting in the driver's seat.

That is, as shown in FIG. 3, the viewpoint P of the driver who sits forward on the driver's seat 8 is set at an average position, and the viewpoint P is directed toward the center plane of the rotating surfaces of the left and right chain wheels 9. When the lines of sight QL and QR are drawn by using the lines of sight QL and QR, the angles αL and αR sandwiched between the lines of sight QL and QR and the center line CL of the vehicle body are preferably used as the inclination angles of the rotating surfaces of the chain wheels. Note that “matching with the line of sight” means physically matching with the angle obtained in the above-mentioned procedure, and ± 3 ° with respect to the angles αL and αR.
Some mounting error can be tolerated. Further, as an example, the angle αL is more preferably 3 ° to 10 ° and the angle αR is more preferably about 13 ° to 18 °, and may be appropriately determined depending on the position of the driver's seat and the relative position of the chain wheel.

Next, when the attachment mechanism having a movable part other than the fork is attached to the lift bracket 6 as the cargo handling tool 5, the lift bracket 6 is provided with a hydraulic actuator (not shown), and A hydraulic supply source (not shown) and this hydraulic actuator need to be connected by a hydraulic hose 20 wound around a hose pulley 19 which moves up and down together with the piston rod 7a, like the chain wheel 9, as shown in FIGS. Also illustrates such a case.

In such a case, when the hydraulic hose 20 is viewed from the driver's seat 8 by inclining the hose pulley 19 substantially parallel to the chain wheel 9 so as to match the line of sight from the driver's seat,
Similar to the chain C, the hydraulic hoses 20 hanging back and forth from the hose pulley 19 appear to overlap each other, which is preferable in that the front field of view can be further improved.

As described in detail above, the present invention can be applied to various cargo handling vehicles other than the above-mentioned forklifts such as reach type forklifts, order picking trucks, side forklift trucks, multidirectional forklifts, and walk type forklifts. .

[0026]

As described above, according to the mast device of the present invention, the chains hanging down from the chain wheels can be overlapped with each other so that the driver can visually recognize the chains. The visibility can be improved and the workability of cargo handling can be greatly improved.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is a rear view showing an embodiment of the present invention.

FIG. 3 is a plan view showing a counterbalanced forklift as a cargo handling vehicle.

FIG. 4 is a side view showing an embodiment of the present invention.

FIG. 5 is a diagram of a conventional mast device viewed from a driver's seat.

[Explanation of symbols]

 2 Fixed Mast 3 Lifting Mast 4 Mast Body 5 Cargo Handling Equipment 6 Lift Bracket 7 Lift Cylinder 7a Piston Rod 8 Driver's Seat 9 Chain Car 10 Connecting Plate C Chain 19 Hose Pulley 20 Hydraulic Hose

Claims (4)

[Claims] 1. A mast body comprising a pair of left and right fixed masts fixed to both sides of a front part of a vehicle body, and a pair of left and right elevating masts vertically movable along the fixed masts. In addition, a lift bracket to which a cargo handling tool such as a fork can be attached is arranged, and left and right lift cylinders for lifting the lifting mast by raising the piston rod are arranged behind the mast body, and one end of the lift bracket is mounted on the lift bracket. In a loading and unloading vehicle provided with a chain wheel that winds a chain that is connected and has the other end immovably fixed and moves a lift bracket up and down at a speed twice that of the lifting mast as the piston rod moves up, The left and right lift cylinders are pivotally supported on both ends of the connecting plate that joins the upper ends of the piston rods, and the rotating surface of each chain car is used to drive the cargo handling vehicle. Mast assembly of cargo handling vehicle, characterized in that it arranged inclined at an angle of front spread by matching the driver's line of sight seated α to. 2. The mast device for a cargo handling vehicle according to claim 1, wherein the angle α is in the range of 3 ° to 25 °. 3. A hose pulley, which has one end connected to a hydraulic actuator on the side of the lift bracket and another end on which a hydraulic hose communicating with a hydraulic power source on the vehicle body can be wound, is rotatable on the connecting plate, and 3. The mast device for a cargo handling vehicle according to claim 1, wherein the mast device is provided so as to be inclined substantially parallel to the chain wheel. 4. The cargo handling vehicle is a counterbalance type forklift having a driver's seat at a position deviated from the center line, and the left and right chain wheels have different tilt angles. The mast device for the cargo handling vehicle described.