JP2001261291A - Lift arm device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lift arm device free to elevate a cargo up and down without inclining it even when the cargo to be a left and right unbalanced load against a pair of left and right lift arms 2 by the lift arm device. SOLUTION: It is possible to elevate a lifted cargo up and down without incliding it without slipping its left and right positions by a pair of left and right lift arms 2 by engagement of gears 15, 16 and rack type engaging parts 5, 6 and the left and right gears 15, 16 connected by an axis of rotation 14 and to be synchronously rotated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lift arm device for lifting and lowering left and right lift arms by an actuator for use in cargo handling and transportation, and more particularly to a lift arm device capable of moving up and down in synchronism with the left and right lift arms.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 7-10486 discloses a technique of synchronizing the movements of left and right lift arms to prevent the load from being tilted when ascending and descending, and adjusting the height of the left and right lift arms. I have.

In this type, an endless chain meshing with the teeth of a sprocket is crossed between left and right sprockets provided in association with a pair of left and right lift arms, and the chain is connected by a turnbuckle to form an endless chain. In this configuration, when the actuator is driven, the rotation of the left and right lift arms is synchronized by the endless chain wound around both sprockets,
It is possible to prevent the luggage from tilting when moving up and down.

[0004] This prior art cannot be compared directly with a lift arm device of the type in which the lift arm is moved up and down linearly, so that it cannot be directly compared. However, the inclination of the load at the time of ascending and descending is synchronized by synchronizing the left and right lift arms. An effective structure is provided as a structure for preventing the occurrence.

Further, a general lift arm device of the type in which the lift arm is moved up and down linearly is used to raise and lower a lift bracket disposed between the left and right masts along the left and right masts. When the lift bracket is driven up and down by an actuator, the lift bracket moves up and down smoothly by the rolling of the roller with the mast as the track, and the left and right attached to the lift bracket The lift arm moves up and down.

The lift bracket moves up and down with the left and right masts as tracks by the rolling of rollers provided on the left and right. However, when an eccentric load is applied to the left and right lift arms, the lift bracket is also moved by the eccentric load of the lift arms. Incline. This is because the rollers provided on the left and right of the lift bracket are rolling individually on the left and right.If the lift bracket is tilted left and right, the rollers will get caught between the mast tracks and the It can not be smooth.

[0007]

Problems to be Solved by the Invention Japanese Patent Laid-Open No. 7-10486
Even if the technology disclosed in Japanese Patent Application Laid-Open Publication No. H10-15064 is directly applied to a lift arm device that linearly raises and lowers a lift arm, it is not possible to synchronize the lift arms that linearly move up and down. In the case of a lift arm that moves up and down linearly, the drive itself that moves up and down the left and right lift arms must be synchronized. It cannot be directly applied to the arm device.

In a lift arm device for linearly moving the left and right lift arms up and down, a mechanism is provided for raising and lowering the left and right lift arms in synchronization with each other. It is an object of the present invention to provide a lift arm device for preventing a load from being inclined. Further, there is provided a lift arm device which can solve the problem and is firmly manufactured at a low cost.

[0009]

In order to solve the above-mentioned problems, a column having a quadrangular cross section so as to provide a space inside and a column having at least a part of one side thereof opened is opposed to the open side and left and right. A pair of upright lift masts, a rack-shaped engaging portion disposed on each inner side of the lift mast and fixed in the extension direction of the lift mast, a lift bracket disposed between the pair of lift masts, and left and right of the lift bracket A roller that moves the lift bracket along the lift mast, a rotating shaft that penetrates the left and right of the lift bracket and is supported by the lift bracket, and a rack that is attached to the left and right of the lift bracket's rotating shaft and that is attached to the left and right masts. Gear that engages with the hooks, actuator mechanism that drives the lift bracket, and attached to the left and right of the lift bracket A lift arm which was a lift arm device comprising a.

[0010] Since the gears attached to the left and right of the rotating shaft penetrating the left and right of the lift bracket are engaged with the rack-shaped engaging portions of the lift mast, if the lift bracket is moved up and down by the actuator mechanism, the left and right can be moved. The gears rotate in synchronism with the rotation shaft, and the left and right gears rotate while engaging with the rack-shaped engaging portions. Therefore, even if an unbalanced load is applied to the left and right lift arms, there is no difference in the height of the left and right lift arms, so that the lift bracket does not tilt left and right. Accordingly, a lift arm device can be provided that prevents the load from being tilted at the time of ascending and descending even when lifting or lowering a load that is biased by the lift arm device.

Since the rack-shaped engaging portion formed by fixing a plurality of pins upright at predetermined intervals in a straight line on the same plane is fixed to the lift mast, an expensive machine tool and time-consuming rack ( Tooth) can be manufactured at a lower cost.
That is, the pins can be formed by welding the pins to the flat plate surface at predetermined intervals. A fitting hole corresponding to the diameter of the fitting portion of the pin may be previously formed in the flat plate by laser processing or punching.

A plurality of pins are erected linearly at predetermined intervals on the same plane to form a rack-shaped engaging portion, and the plurality of pins of the rack-shaped engaging portion are lifted in correspondence with the plurality of pins. Since the support was inserted into the opening of the support wall of the mast by inserting the support from the outside to the inside of the support, fixing the pins at predetermined intervals on the flat plate surface was as described above. Since the pins are inserted and fixed from the outside of the pillar to the inside of the pillar mast opening in the pillar wall corresponding to the plurality of pins, there is no variation in the mounting position of the rack-shaped engaging portion. Since the rack-shaped engaging portion is fixed to the lift mast, the pins are fixed by the plate thickness to which the pin is fixed and the plate thickness of the lift mast to which the pin is inserted, so that a strong rack-shaped engaging portion can be obtained.

Further, a rack-shaped engaging portion is formed by a chain,
If the gear is a sprocket, commercially available parts can be diverted. Therefore, the mass production of the apparatus according to the present invention is optimal in terms of the number of parts and unit price, and a lift arm apparatus can be provided with reduced costs.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a lift arm device according to the present invention will be described with reference to FIGS. FIG. 1 shows a side view of a lift arm device 1 according to the present invention. FIG. 2 is a sectional view of the lift masts 3 and 4 viewed from the lift arm 2 side. FIG. 3 is a sectional view of the lift mast 3 as viewed from the side of the lift arm device. FIG. 4 shows an embodiment of the rack-shaped engaging portion 5. The lift arm device 1 shown here is a lift arm device generally called a hand lift. Hereinafter, a hand lift 1 is used instead of the lift arm device 1.
It will be described as.

The hand lift 1 has a column having a quadrangular cross section so as to provide a space inside, and a column, for example, a C-shaped steel material having at least a part of one side thereof opened. A pair of lift masts 3 and 4 provided
And the rack-shaped engaging portions 5 and 6 arranged and fixed in the space inside the lift masts 3 and 4 along the extension direction of the lift masts 3 and 4 and arranged between the pair of lift masts 3 and 4. A lift bracket 7 provided with a pair of left and right lift arms 2, and a left and right shaft 8, 9 of the lift bracket 7 for moving the lift bracket 7 along the lift masts 3, 4. Rollers 10 and 11 that are rotatably fixed and roll inside the lift masts 3 and 4 along the walls of the lift masts 3 and 4 and the bearings 12 and 13 of the lift bracket 7 that penetrate right and left of the lift bracket 7. The rotating shaft 14 to be supported and the gears 15, 16 attached to the left and right of the rotating shaft 14 of the lift bracket 7 and engaged with the rack-shaped engaging portions 5, 6 in the left and right lift masts 3, 4. Eteiru.

Further, the lift bracket 7 is driven up and down by an actuator mechanism 17. The actuator mechanism 17 is provided in parallel with the lift masts 3 and 4, and includes a hydraulic cylinder 18 in which a rod moves upward and downward and a pulley 20 which freely rotates at an upper end of the rod 19 of the hydraulic cylinder 18; Bracket 7 and hydraulic cylinder 18
A traction chain 21 of a predetermined length is stretched between the pulley 20 and the pulley 20. Further, the actuator mechanism 17 includes a hydraulic pump 22 for supplying a hydraulic pressure to the hydraulic cylinder 18, a manual arm 23 for driving the hydraulic pump 22, and a release arm 24 for releasing the hydraulic pressure.

Here, the constructions of the lift masts 3, 4 and the lift bracket 7, the rollers 10, 11 and the actuator mechanism 17 have a structure common to the conventional lift arm device.

The operation of the hand lift 1 in the above configuration will be described. When the manual arm 23 is operated up and down,
The hydraulic pressure is supplied to the hydraulic cylinder 18 by the hydraulic pump 22. Accordingly, the rod 19 rises. Rod 1
When the lift 9 rises, the chain 21 is pushed up along the pulley 20, and the lift bracket 7 rises accordingly.
Thus, the lift arm 2 attached to the lift bracket 7 is raised. When the release arm 24 is pressed down, the hydraulic pressure supplied from the hydraulic pump 22 to the hydraulic cylinder 18 is released, and the rod 19 descends, so that the lift arm 2 descends.

Since the wheels 31 and 32 for moving the hand lift 1 are provided on the floor surface 30 on which the hand lift 1 is placed, the hand lift 1 can be pushed and moved by the moving arm 33.

Next, a characteristic configuration according to the present invention will be described with reference to FIGS. The rack-shaped engaging portion 5 (6) and the gear 15 (16) are engaged, and the left and right gears 15, 1
6 are connected by the rotating shaft 14, so that the right and left gears 15, 16
Are rotated in synchronization with each other, and there is no left and right misalignment due to the engagement between the gears 15, 16 and the rack-shaped engaging portions 5, 6. In other words, even if the left and right eccentric loads are lifted with respect to the pair of left and right lift arms 2 by the hand lift 1 of the present invention, the engagement between the gears 15 and 16 and the rack-shaped engaging portions 5 and 6 and the rotation shaft The right and left gears 15 and 16 connected by 14 and rotated in synchronism allow the pair of left and right lift arms 2 to move up and down without the right and left heights deviating and tilting, that is, without tilting the load lifted by the lift arms. Can be done. By the way, since the engaging portions between the rack-shaped engaging portions 5, 6 and the gears 15, 16 of the present application are housed in the lift masts 3, 4, a special safety cover is not required and the other operating mechanisms are not obstructed. It will not be.

Considering the load applied to the rack-shaped engaging portions 5 and 6 and the gears 15 and 16 when an eccentric load occurs, basically, the load of the pair of lift arms 2 is applied to the lift bracket 7. In addition, a load difference caused by a laterally eccentric load acts on the rotating shaft 14 to which the gears 15 and 16 are fixed, as a rotating torque. That is, since the load does not directly span the engagement portions between the gears 15 and 16 and the rack-shaped engagement portions 5 and 6, the strength for supporting the entire load is not required.

By the way, as shown in FIG.
By setting the diameters of a and 10b slightly smaller than the width of the lift mast 5, the right side of the roller 10a contacts the inner wall 40 of the lift mast 3 with the lift arm 2 under its own weight or under a load. , The left side of the roller 10b can be brought into contact with the inner wall 41 of the lift mast 3, so that the roller 10 (11) rolls in the lift mast 5 (6) without hindrance, and the lift bracket 7 is lifted. It can be moved along 3,4. Further, since the rollers 10a and 10b (11a and 11b) are arranged above and below the gear 15 (16), the rollers 10a (11
a) and each of the rollers 10b (11b) is in contact with only one wall of the lift mast 3 (4), and the rollers 10a (11a) with respect to the longitudinal center line of the lift mast 3.
Even if the axis connecting the roller 15b and the roller 10b (11b) is inclined, the inclination is substantially caused by rotation about the gear 15 (16) as a center point, so that the position of the gear 15 (16) There is no large change with respect to the part 5 (6). In particular, the rolls 10a (11a) and the rolls 10b (11b) are arranged at equal intervals in the vertical direction around the gear 15 (16).
This tendency is remarkable if.

Next, the rack-shaped engaging portions 5 and 6 will be described with reference to FIGS. FIG. 4 shows an example of the rack-shaped engaging portion. The rack-shaped engaging portion 5 (6) includes a so-called rack in which teeth of the same shape are carved at equal intervals on one surface of a flat plate or a straight rod, and as shown in FIG. The pin 43 may be fixed to the flat plate 42 by disposing the pin 43. It may be fixed by adding the flat plate 42 and the pin 43 to each other. In order to attach and fix the rack-shaped engaging portion 5 (6) shown in FIG. 4 to the lift mast 3 (4), a plurality of holes (not shown) corresponding to the pins 43 are opened in the side wall 44 of the lift mast 3. Then, the pins 43 may be inserted into the holes from the outer side 45, and the flat plate 42 may be fixed to the lift mast 3 as desired in the lift mast 3. As the fixing means, the outside 45 of the lift mast 3 and the flat plate 42 are welded by welding, or similarly, bolting can be applied.

Further, the rack-shaped engaging portion 5 (6) formed as shown in FIG.
And the flat plate 42 and the inner side 46 are welded by welding, or similarly bolting can be applied.

FIG. 5 shows another embodiment of the rack-shaped engaging portion.
This will be described below. The one shown in FIG.
0 is formed by a chain 51, and a gear is a sprocket 52. What is necessary is just to fix the chain 51 of a predetermined length to the inner wall 41, and welding or bolting can be applied to the fixing means as described above. In this case, a commercially available chain 51 and sprocket 15 can be used. Since the pins of the chain 51 are connected to each other, the chain 51 has a structure that can withstand use.

Although the above embodiment has been described as a hand lift, it is needless to say that the present invention can also be applied to a lift arm device driven by an engine, and to a device in which the lift arm is moved up and down linearly.

[0027]

According to the present invention, even when a load which is eccentrically loaded on a pair of left and right lift arms is lifted, the engagement between the gear and the rack-shaped engaging portion, and the left and right gears which are connected by the rotating shaft and rotate synchronously. Thus, the pair of left and right lift arms can be raised and lowered without shifting the left and right, that is, without tilting the lifted luggage.

The rack-shaped engaging portion can be formed only by fixing pins at regular intervals on a straight line with respect to the flat plate. In addition, since it can be realized by a combination of a commercially available chain and sprocket, no special device or part is required, and the present invention in which a new part is added can be manufactured inexpensively as a whole.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a lift arm device according to the present invention.

FIG. 2 is a diagram showing a cross-sectional structure inside a lift mast viewed from a lift arm side.

FIG. 3 is a diagram showing a cross-sectional structure inside a lift mast viewed from a side.

FIG. 4 is an embodiment of a rack-shaped engaging portion.

FIG. 5 shows a case where a rack-shaped engaging portion is formed by a chain.
It is a figure showing the section structure in a lift mast seen from the side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hand lift (lift arm device) 2 Lift arm 3 Lift mast 4 Lift mast 5 Rack-shaped engaging part 6 Rack-shaped engaging part 7 Lift bracket 8 Shaft 9 shaft 10 Roller 11 Roller 12 Bearing 13 Bearing 14 Rotating shaft 15 Gear 16 Gear 17 Actuator mechanism 18 Hydraulic cylinder 19 Rod 20 Pulley 21 Traction chain 22 Hydraulic pump 22 23 Manual arm 24 Release arm 30 Floor surface 31 Wheel 32 Wheel 33 Moving arm 40 Inner wall of lift mast 41 Inner wall of lift mast 42 Flat plate 43 Pin 44 Side wall of lift mast 45 Outside 46 Inside of lift mast 50 Rack-shaped engaging part 51 Chain 52 Sprocket

Claims (4)

[Claims] 1. A pair of lift masts having a quadrangular cross-section so as to provide a space inside, and a pair of lift masts standing upright at right and left with at least a part of one side being open with the open sides facing each other; And a rack-shaped engaging portion fixed to the extension direction of the lift mast, a lift bracket disposed between the pair of lift masts, and a lift bracket provided on the left and right sides of the lift bracket and moved along the lift mast A roller to be driven, a rotating shaft that penetrates the left and right of the lift bracket and is supported by the lift bracket, a gear attached to the left and right of the rotating shaft of the lift bracket and engaged with a rack-shaped engaging portion in the left and right masts, It is characterized by comprising an actuator mechanism for driving the bracket, and lift arms attached to the left and right of the lift bracket. Lift arm device. 2. A rack-shaped engaging portion formed by standing and fixing a plurality of pins in a straight line and at predetermined intervals on the same plane is fixed to a lift mast.
The lift arm device as described. 3. A rack-shaped engaging portion is formed by standing and fixing a plurality of pins linearly and at predetermined intervals on the same plane, and a plurality of pins of the rack-shaped engaging portion are attached to the plurality of pins. 2. The lift arm device according to claim 1, wherein the lift mast is inserted into the support mast from the outside of the support mast and fixed inside the opening of the support mast. 4. The lift arm device according to claim 1, wherein the rack-shaped engaging portion is formed by a chain, and the gear is a sprocket.