JP2012144333A - Forklift - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a forklift that facilitates right-angle stowage, and also prevents contact of the vehicle body of the forklift with the surroundings during performing the right-angle stowage.SOLUTION: By disposing the rear end of an actuator section 30 on or near the turn orbit TO during performing the right-angle stowage of a forklift 1, a loading section is drawn more rearward with respect to a vehicle body 10, a length of projection from a turn center to the front of the vehicle body 10 is shortened, and right-angle stowage is facilitated. Further, since the turn orbit TO where a distance from the turn center during the right-angle stowage to a part farthest from the turn center at the rear end of the vehicle body 10 is a turn radius is not expanded, contact of the vehicle body 10 of the forklift 1 with the surroundings during performing the right-angle stowage is prevented.

Description

  The present invention relates to a forklift, and more particularly to a forklift suitable for preventing contact during turning of the forklift.

  In general, a reach forklift (hereinafter referred to as “forklift”) is known as a vehicle used for transporting luggage (see, for example, Patent Document 1). The forklift is provided with a fork (claw) for handling a load in front of the vehicle, a mast (support) for supporting the fork so as to be movable in the vertical direction, and the like. The rear wheels of the forklift are steered wheels that are steered, and the front wheels are idle wheels that are not steered. A forklift is a counterbalanced forklift in which the fork and mast are attached so as to be movable in the longitudinal direction of the vehicle, the fork and mast are directly attached to the front of the vehicle, and a counterweight is provided at the rear of the vehicle. Is different.

  A forklift is used for loading cargo stored in a warehouse and loading a warehouse to store the cargo. At this time, after the forklift travels in the warehouse passage, it turns to the right or left, loads the luggage from the shelf provided on the side of the passage, and loads the luggage onto the shelf. Turn in the direction or to the right and drive towards the destination that carries the load. Hereinafter, the forklift turns and loads and loads are loaded as “right-angle loading”.

  As described above, the passage width necessary for the forklift to stack rightward or leftward in the right direction is called a right-angled passage width. By setting the width of the passage of the warehouse to be equal to or greater than the width of the right-angle loading passage, the forklift can load right-angle without contact with the side wall of the passage, the shelf, or the luggage stored in the warehouse.

  Here, the right-angle product passage width will be described with reference to FIG. FIG. 5 shows a right-angle product passage width in a forklift having two front wheels and one steering rear wheel on the left rear.

  FIG. 5A illustrates the right-angle product passage width when the forklift turns right. In this case, the right-angle product passage width is defined as a distance BR from the left rear end of the forklift body to the right turning center PR and a distance AR from the right front end of the load loaded on the forklift to the right turning center PR. Sum (AR + BR).

  FIG. 5B illustrates the right-angle product passage width when the forklift turns left. The width of the right-angle product passage when turning left is the distance BL from the right rear end of the forklift body to the left turning center PL and the distance AL from the left front end of the load loaded on the forklift to the left turning center PL. Sum (AL + BL).

  The right turning center PR when the forklift turns right is a straight line connecting the centers of the two front wheels 11 and a straight line connecting the left rear end of the body of the forklift and the right front end of the load PT loaded on the forklift. It is an intersection. Similarly, the left turning center PL when the forklift turns left is a straight line connecting the centers of the two front wheels 11, a straight line connecting the right rear end of the body of the forklift and the left front end of the load PT loaded on the forklift, Is the intersection of

JP 2003-073092 A

  When a forklift is loaded at a right angle (turns when loading and turning, or turning when loading), if the forklift can be brought close to the shelf on which the load is placed, It becomes easy to prevent contact with the side wall or shelf on the opposite side of the passage.

  However, when the forklift makes a left turn, in order to avoid contact between the luggage and the shelf, the distance from the left turn center PR to the shelf on which the luggage is placed needs to be equal to or longer than the distance AR. Similarly, when turning right, the distance from the right turning center PL to the shelf on which the luggage is placed needs to be equal to or longer than the distance AL. Therefore, when turning the forklift, the forklift cannot be brought closer to the shelf on which the luggage is placed than the distances AR and AL, and it becomes difficult to prevent the body of the forklift from contacting the side wall of the passage.

  As a method for solving the above-described problem, a method for shortening the forward projecting length from the front wheel in the forklift can be considered. However, there is a problem that the forward protruding length of a reach type forklift loaded with a load cannot be easily shortened. That is, the range in which the fork, mast, etc. can be pulled backward (reach-in) is determined by the arrangement position and configuration of the reach cylinder, etc., for moving the fork, mast, etc., as described in Patent Document 1. Therefore, it is not easy to move the reachable range to the rear of the vehicle to shorten the forward protrusion length.

  The present invention has been made to solve the above-described problem, and provides a forklift that facilitates right-angle loading and can prevent the vehicle body of the forklift from coming into contact with the periphery during right-angle loading. The purpose is to provide.

In order to achieve the above object, the present invention provides the following means.
The forklift of the present invention is a forklift that uses a rear wheel for steering and includes a cargo handling part that transports cargo on the front wheel side, and this cargo handling part can be moved in the front-rear direction of the vehicle by an actuator part. The actuator portion is formed in a long shape including a cylinder portion and a piston, and one of the cylinder portion and the piston is attached to the cargo handling portion, and the other is attached to the vehicle main body. The actuator part is arranged extending in the vehicle front-rear direction, which is the moving direction of the cargo handling part.

  Further, the rear end of the actuator portion is disposed on or in the vicinity of a turning track having a turning radius that is a distance from the turning center of the forklift to the farthest part from the turning center at the rear end of the vehicle body. Therefore, the actuator unit is arranged on the rear side of the forklift without increasing the above-mentioned turning radius as compared with the case where the rear end is not arranged on or in the vicinity of the turning track.

  If the turning center when the forklift makes a right turn and the turning center when the forklift makes a left turn are different from each other, both the right turn and the left turn trajectory at the position where the actuator unit is disposed. The rear end of the actuator unit is arranged on or near the front track.

  Note that the arrangement of the rear end of the actuator unit in the vicinity of the turning track means that if the actuator unit is housed inside the vehicle and the rear end of the vehicle is formed along the turning track, the actuator unit The rear end is arranged as close as possible to the turning trajectory.

  By arranging the actuator part on a straight line extending in the front-rear direction in the vehicle body from the turning center, the actuator unit can be arranged closer to the rear side in the vehicle body than in the case where it is arranged at other positions. For example, when the turning center when the forklift makes a right turn and the turning center when the forklift makes a left turn are the same, the actuator unit can be arranged at the rearmost position in this way.

  Alternatively, by arranging the actuator portion on the center line extending in the front-rear direction in the vehicle main body, the actuator portion can be arranged closer to the rear side in the vehicle main body than in the case where it is arranged at other positions. For example, when the turning center when the forklift makes a right turn is different from the turning center when the forklift makes a left turn, the actuator unit can be arranged at the rearmost position in this way.

  By providing a weight in an adjacent region near the rear end of the actuator portion, this weight can be used as a counterweight when a load is loaded on the cargo handling portion. The adjacent area in the vicinity of the rear end of the actuator portion is a space that is narrower than other areas and is difficult to use for arranging equipment used for forklifts, but this area has a high degree of freedom in shape. By arranging the weight, it can be used effectively.

  According to the forklift of the present invention, the actuator unit can be arranged on the rear side of the forklift without increasing the above-mentioned turning radius as compared with the case where the rear end is not arranged on or in the vicinity of the turning track. As a result, the cargo handling part that is moved in the front-rear direction by the actuator part is also drawn backwards with respect to the vehicle body, and the length that protrudes from the turning center to the front of the vehicle body can be shortened. There is an effect that it can be made easy. Furthermore, since the turning trajectory with the turning radius from the turning center when the forklift is loaded at right angles to the farthest part from the turning center at the rear end of the vehicle body is not enlarged, the vehicle body of the forklift is loaded at right angles. There is an effect that it is possible to prevent contact with the surroundings.

It is a mimetic diagram explaining the whole forklift concerning the embodiment of the present invention. It is a schematic diagram explaining the arrangement | positioning position of the reach cylinder in the forklift of FIG. FIG. 2 is a schematic diagram for explaining a distance A from the right or left front end of the pallet to the turning center and a distance B from the left or right rear end of the vehicle main body to the turning center P when the forklift of FIG. 1 turns left or right. is there. It is a schematic diagram explaining the other example of the rear end shape in the forklift of FIG. It is a schematic diagram explaining the right-angle product passage width when a forklift turns right and turns left.

  A forklift (reach forklift) according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic diagram illustrating the overall configuration of a forklift 1 according to this embodiment, FIG. 1 (a) is a plan view, and FIG. 1 (b) is a side view.

  The forklift 1 according to this embodiment is used for transporting luggage, and is particularly used for cargo handling work in a factory, a warehouse, a freight station, a port, or the like. As shown in FIG. 1, the forklift 1 is mainly provided with a vehicle main body 10 on which a driver enters and a cargo handling unit 20 that handles luggage.

  FIG. 2A is a diagram for explaining the arrangement position of the reach cylinder in the conventional forklift, and FIG. 2B is a diagram for explaining the arrangement of the reach cylinder 30 in the forklift 1 of FIG.

  The vehicle main body 10 is mainly provided with front wheels 11 and rear wheels 12 used for traveling of the forklift 1, an outrigger 13 on which the front wheels 11 are arranged, and a driver seat 14 on which a driver gets. Further, as shown in FIG. 2B, the vehicle body 10 is provided with a reach cylinder (actuator portion) 30 that moves the cargo handling portion 20 in the front-rear direction with respect to the vehicle body.

  The front wheels 11 are a pair of wheels respectively disposed at the front end of the outrigger 13 as shown in FIGS. 1 (a) and 1 (b). In the present embodiment, description will be made by applying to an example in which the front wheel 11 is an idle wheel in which the direction of the rotation shaft is fixed with respect to the vehicle body 10. The rear wheel 12 is a single wheel disposed at the left rear end of the vehicle body 10. The rear wheel 12 is a driving wheel to which a rotational driving force is transmitted from a driving unit (not shown) such as a motor, and the traveling direction of the forklift 1 in which the direction of the rotating shaft with respect to the vehicle body 10 can be changed. It is also a steering wheel to be determined. In the present embodiment, description will be made by applying to an example in which auxiliary wheels (not shown) are provided below the driver's seat 14. Note that only one rear wheel 12 may be provided as described above, or a pair may be provided on the left and right of the vehicle main body 10 in the same manner as the front wheel 11, and there is no particular limitation.

  The outriggers 13 are a pair of arm-like members provided on the lower front side of the vehicle main body 10, and are arranged so as to extend in parallel from the left and right ends of the front lower end of the vehicle main body 10 toward the front. . A cargo handling section 20 is disposed between the pair of outriggers 13 and 13, and the cargo handling section 20 is movable between the pair of outriggers 13 and 13 in the front-rear direction.

  The driver's seat 14 is a place where the driver gets into the forklift 1 and operates the forklift 1 in a standing posture. The driver's seat 14 is provided at the right rear end of the vehicle body 10, and a handle 15 for steering the rear wheel 12 is provided. In addition, an operation unit 16 such as a lever for operating the cargo handling unit 20 is provided in the driver's seat 14. The driver may drive the forklift 1 in a standing posture as described above, or may drive the forklift 1 in a sitting posture, and is not particularly limited.

  The reach cylinder 30 is a hydraulic cylinder that moves the cargo handling unit 20 in the front-rear direction of the vehicle main body 10, and is disposed along a center line CL extending in the front-rear direction of the vehicle main body 10, as shown in FIG. It is a thing. The reach cylinder 30 is mainly provided with a cylinder part 31 formed in a cylindrical shape and a piston 32 that moves in the cylinder part 31 along the axis of the cylinder.

  The cylinder portion 31 is fixed to the vehicle body 10 and is partitioned into two rooms by a piston 32. The cylinder part 31 is provided with an inflow / outlet port 33 through which pressurized oil flows into the respective chambers from the outside or from the inside to the outside.

  The piston 32 receives the pressure of the oil supplied to the cylinder part 31 and protrudes from the cylinder part 31 to extend the entire length of the reach cylinder 30 or is housed inside the cylinder part 31 to shorten the reach cylinder 30. To do. A front end portion of the vehicle main body 10 at the piston 32 is attached to the cargo handling portion 20.

  The vehicle body 10 includes a hydraulic pump (not shown) for supplying pressurized oil to the reach cylinder 30, a switching valve (not shown) for controlling the supply destination of the pressurized oil, and oil for storing oil. A tank (not shown) and the like are stored.

  As shown in FIGS. 1 (a) and 1 (b), the cargo handling unit 20 includes a fork 21 used to load a load, a lifting body 22 to which the fork 21 is attached, a fork 21 and a lifting body 22. A mast 23 that moves in the vertical direction is mainly provided.

  The fork 21 is a pair of arm-like members provided on the front surface of the elevating body 22, and is arranged so as to extend in parallel from the left and right ends of the lower end of the front surface of the elevating body 22 toward the front. The fork 21 is inserted into an insertion hole of a pallet PT formed in an approximately rectangular parallelepiped shape on which a load is placed, and lifts or lowers only the pallet PT or the pallet PT on which the load is placed. .

  The elevating body 22 supports the fork 21 and is movable up and down along the mast 23 by an elevating cylinder (not shown) arranged between the elevating body 22 and the mast 23. .

  The mast 23 is a pair of columnar members arranged in parallel and facing each other, and is arranged extending in the vertical direction. Further, the pair of masts 23 and 23 are supported by the fork 21 and the lifting body 22 disposed between them so as to be vertically movable.

  Here, the arrangement position of the reach cylinder 30, etc., which is a feature of the present embodiment, will be described with reference to FIG. In the present embodiment, description will be made by applying to an example in which the turning center P at the time of right-angle loading in the forklift 1 is on a straight line connecting the rotation axes of the left and right front wheels 11 and in the center of the left and right front wheels 11. .

  In the present embodiment, the shape of the rear end of the vehicle body 10 is on the turning track TO having a turning radius that is a distance R from the turning center P to the left and right rear ends of the vehicle body 10 as shown in FIG. Are formed along the turning trajectory TO. Reach cylinder 30 is arranged with its rear end close to the inner wall surface of vehicle body 10. In other words, the rear end of the reach cylinder 30 is arranged behind the rear end of the vehicle body 10 in the conventional forklift.

  Compared with a conventional forklift (see FIG. 2A), the rear end of the reach cylinder 30 is located behind the vehicle body 10 by a distance DA that the rear center of the vehicle body 10 protrudes rearward (see FIG. 2). 2 (b)). As a result, when the reach cylinder 30 is most contracted (reach-in), the front end of the vehicle body 10 (upward in FIG. 2B) of the reach cylinder 30 or the piston 32 moves backward by the distance DC. Yes.

  The distance DC is approximately half the distance DA when the relative position with respect to the vehicle body 10 when the cargo handling portion 20 protrudes forward (reach out) is set to be the same. On the other hand, if the relative position between the cargo handling unit 20 and the vehicle main body 10 at the time of reach-out is allowed to change, the length can be made approximately equal to the distance DA.

  Furthermore, in the interior of the rear end of the vehicle main body 10 of the forklift 1 according to the present embodiment and adjacent to the reach cylinder 30, a counterweight (which acts to balance when the cargo handling unit 20 lifts the load) A weight 34 is provided. In general, the reach type forklift of this embodiment is less necessary to provide the counterweight 34 than the counterbalance type forklift, but by providing the counterweight 34, it is possible to stabilize when the load is lifted by the cargo handling unit 20. Can be improved.

  As described above, the rear end of the vehicle main body 10 may be formed on the turning track TO along the turning track TO, or only in the vicinity where the reach cylinder 30 is disposed. It may be formed in a shape that protrudes upward or in the vicinity thereof, and is not particularly limited.

Next, the operation of the forklift 1 having the above configuration will be described with reference to FIGS. 1 and 2.
As shown in FIG. 1, the forklift 1 travels to the vicinity of the load with the cargo handling unit 20 being reached, and stops at a position where the fork 21 faces the insertion hole of the pallet PT. Thereafter, the pressurized oil is supplied to the rear chamber of the reach cylinder 30, the piston 32 protrudes from the cylinder portion 31, and pushes the cargo handling portion 20 forward of the forklift 1 (reach out). Thereby, the fork 21 is inserted into the insertion hole of the pallet PT.

  Thereafter, the pallet PT is lifted by the cargo handling unit 20, the pressurized oil is supplied to the front chamber of the reach cylinder 30, the piston 32 is drawn into the cylinder unit 31, and the cargo handling unit 20 is moved to the vehicle body 10. Attracted (reached in). At this time, in the forklift 1 of the present embodiment, the length protruding forward from the turning center P is shorter by the distance DC than the conventional forklift.

  3 shows the distance A from the right or left front end of the pallet PT to the turning center P when the left or right turn of the forklift 1 of FIG. 1 and the distance from the left or right rear end of the vehicle body 10 to the turning center P. It is a schematic diagram explaining the distance B. FIG.

  The forklift 1 turns rightward or leftward, travels to a desired position, and then turns rightward or leftward again to place a load. When the forklift 1 turns, the length that protrudes forward from the turning center P is shortened by the distance DC. Therefore, as shown in FIG. 3, the right or left front of the pallet PT that is the load that the forklift 1 is lifting is shown. The distance A from the end of the to the turning center P is also shortened.

  That is, it is possible to shorten the distance from the shelf on which the luggage is placed or the shelf on which the luggage is loaded to the turning center P in the forklift 1 that must be secured to prevent contact between the luggage and the shelf at the time of turning. In other words, it is possible to turn the forklift 1 with these forks placed on these shelves. As a result, it becomes easy to secure a distance between the left or right rear end of the vehicle main body 10 in the forklift 1 and the wall surface or shelf of the passage on the opposite side to the above-described shelf, and contact can be prevented.

FIG. 4 is a schematic diagram for explaining another example of the rear end shape of the forklift 1 shown in FIG.
When the forklift 1 turns right and turns left as in the above-described embodiment, the turning center P is the same as shown in FIG. The shape of the rear end of the vehicle body 10 in the forklift 1 and the arrangement position of the reach cylinder 30 may be determined. As shown in FIG. 4, the position of the turning center PR in the right turn and the turning center PL in the left turn. If the position of the vehicle body 10 is different, the shape of the rear end of the vehicle body 10 and the position of the reach cylinder 30 are determined based on both the turning trajectory TOR in the right turn and the turning trajectory TOL in the left turn. . Specifically, the shape of the rear end of the vehicle main body 10 is formed on or near the track close to the vehicle main body 10 among the turn trajectory TOR and the turn trajectory TOL.

  At this time, the turning trajectory TOR and the turning trajectory TOL intersect on the center line CL, and the distance at which the vehicle body 10 protrudes rearward at the intersection becomes long. Therefore, the reach cylinder 30 can be arrange | positioned most rearward by arrange | positioning the reach cylinder 30 on the centerline CL.

  In the above-described embodiment, the reach cylinder 30 is described as being applied to an example in which the reach cylinder 30 is arranged in parallel to and on the center line CL. However, the rear end of the reach cylinder 30 is a conventional forklift. As long as the reach cylinder 30 is arranged behind the rear end of the vehicle body 10, the reach cylinder 30 may be arranged at a distance from the center line CL and in parallel with the center line CL. It may be arranged to intersect with the line CL, and is not particularly limited.

  DESCRIPTION OF SYMBOLS 1 ... Forklift, 10 ... Vehicle main body, 20 ... Cargo handling part, 11 ... Front wheel, 12 ... Rear wheel, 30 ... Reach cylinder (actuator part), 31 ... Cylinder part, 32 ... Piston, 34 ... Counterweight (weight)

Claims (4)

A vehicle body provided with a pair of front wheels and a rear wheel used for steering;
A cargo handling part that is disposed on the front wheel side of the vehicle body and used for transporting luggage;
A forklift provided in the vehicle main body and provided with an actuator portion including a cylinder portion and a piston for moving the cargo handling portion in the front-rear direction of the vehicle main body,
A rear end of the actuator portion on a turning track having a turning radius that is a distance from a turning center existing on a line connecting the pair of front wheels to a rear end of the vehicle main body and farthest from the turning center, or A forklift that is arranged in the vicinity.   2. The forklift according to claim 1, wherein the actuator unit is arranged on a straight line extending in the front-rear direction of the vehicle body from the turning center.   The forklift according to claim 1, wherein the actuator unit is disposed on a center line extending in the front-rear direction of the vehicle.   The forklift according to any one of claims 1 to 3, wherein a weight is provided in an adjacent region near the rear end of the actuator portion.

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