JP2021031267A - Mobile lift - Google Patents

Abstract

To provide a mobile lift usable for various cargo handling operations.SOLUTION: A mobile lift comprises: a body frame having a pair of guide posts; runners respectively provided on a caster 5 by which the body frame is supported so as to freely move and on the guide post, so as to be freely lifted/lowered; a cargo receiving table fixed to a runner lower part; and a lifting/lowering drive mechanism for liftingly driving the cargo receiving table. The lifting/lowering drive mechanism has: a pair of single-moving hydraulic cylinder sets 90A, 90B respectively accommodated in the pair of guide posts; a hydraulic circuit 100 for driving the cylinder sets 90A, 90B; and a power unit 130 for supplying hydraulic oil to the hydraulic circuit 100. The hydraulic circuit 100 has synchronous valves 121A, 121B by which respective flow rates of hydraulic oils in hydraulic oil delivery and return directions are made even relative to the pair of cylinder sets 90A, 90B.SELECTED DRAWING: Figure 8

Description

The present invention relates to a mobile lift in which a load receiving table is vertically provided on a main body frame with wheels.

As a mobile lift of this type, a mobile vehicle body having a fork that moves up and down, that is, a forklift is widely known (for example, Patent Document 1 below).

Japanese Unexamined Patent Publication No. 8-12285

The mobile lift shown in Patent Document 1 has a structure for raising and lowering a fork, and is limited to cargo handling using a pallet.

On the other hand, although a cargo bed lifting device to be mounted on a freight vehicle is known, it is necessary to mount the cargo receiving platform lifting device on the truck in advance.

There is a demand for a device that efficiently performs cargo handling work between a freight vehicle and the ground that is not equipped with a cargo receiving platform lifting device, and cargo handling work between a freight vehicle carrier and a warehouse platform having a different height.

The present invention has been made in recognition of this situation, and an object of the present invention is to provide a mobile lift that can be used for various cargo handling operations. Another object of the present invention is to provide a highly reliable mobile lift for an elevating drive mechanism of a loading platform.

One embodiment of the present invention is a mobile lift. This mobile lift is provided on a main body frame having a pair of guide posts, a horizontal frame portion arranged between the pair of guide posts, wheels for movably supporting the main body frame, and the pair of guide posts. Each of the runners is provided so as to be able to move up and down, a load receiving table fixed to the lower part of the runner, and a lifting drive mechanism for raising and lowering the runner and the load receiving table.
The elevating drive mechanism has a hydraulic cylinder housed in a pair of guide posts, a hydraulic circuit for driving the hydraulic cylinder, and a power unit for supplying hydraulic oil to the hydraulic circuit, and one end of the hydraulic cylinder. The portion is connected to the guide post, and the other end is connected to the runner.
The hydraulic circuit is characterized by having a tuning valve for all the hydraulic cylinders that evenly aligns the hydraulic oil flow rates in the delivery and return directions of the hydraulic oil.

The caster stopper is rotatably provided on the front edge side of the load receiving table, and the trailing edge portion of the caster stopper may protrude from the upper surface of the load receiving table due to its own weight at the non-landing position of the load receiving table.

It is preferable that the transfer plate is rotatably provided on the trailing edge side of the load receiving table, and has a guide mechanism for raising the transfer plate in the deployed state while the load receiving table is descending from a predetermined rising position.

The guide mechanism may have a roller attached to a side portion of the transfer plate and a guide member fixed to the guide post and abutting on the roller.

Instead of the hydraulic cylinder, it is preferable to use a hydraulic cylinder set in which the main bodies of the paired hydraulic cylinders are integrated so that the piston rods are oriented in opposite directions.

Any combination of the above components and a conversion of the expression of the present invention between methods, systems and the like are also effective as aspects of the present invention.

According to the mobile lift according to the present invention, the main body frame movably supported by wheels is provided with a loading platform so as to be able to move up and down, and can be used for various cargo handling operations. Further, since the load receiving table is driven up and down by hydraulic cylinders housed in the pair of guide posts, the reliability of the up and down operation is high. In addition, during the lift drive, the tuning valve in the hydraulic circuit makes the flow rate of the hydraulic oil even in the sending and returning directions of the hydraulic oil for all the hydraulic cylinders, so that the tilt of the load receiving table during the lifting operation can be adjusted. Can be prevented.

The left side view which shows the embodiment of the mobile lift which concerns on this invention. The same front view. The same plan view. The cross section of the guide post in the embodiment, (A) is an upper plan sectional view, (B) is an intermediate section plan sectional view, and (C) is a lower plan sectional view showing a runner connecting portion. The side view explaining the automatic standing operation of the transfer board in embodiment. FIG. 5 is a side view showing a set of single-acting hydraulic cylinders used in place of one single-acting hydraulic cylinder in the embodiment. In the embodiment, the lock mechanism holds the transfer plate in an upright state, (A) is a front view, and (B) is a side view. In the embodiment, a hydraulic circuit diagram showing a power unit and a hydraulic circuit as a hydraulic source for driving the loading platform up and down.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. The same or equivalent components, members, processes, etc. shown in the drawings are designated by the same reference numerals, and redundant description will be omitted as appropriate. Moreover, the embodiment is not limited to the invention but is an example, and all the features and combinations thereof described in the embodiment are not necessarily essential to the invention.

In FIGS. 1 to 4, the mobile lift 1 is in a horizontal state fixed to a main body frame 10 having casters 5 as wheels attached to the bottom, a runner 30 provided on the main body frame 10 so as to be able to move up and down, and a runner 30. It is equipped with a load receiving stand 50 that can be raised and lowered.

The main body frame 10 includes a bottom frame portion 11, a pair of guide posts 15 vertically erected and fixed on both left and right sides of the bottom frame portion 11, a horizontal frame portion 12 arranged between the pair of guide posts 15, and a back surface. It has a guard 13. The rear guard 13 communicates between the pair of guide posts 15 and forms a vertical surface inside the lateral frame portion 12. The back ghat 13 is provided at a height that does not interfere with the unfolding operation of the transfer plate 70, which will be described later. A side frame portion 14 that also serves as reinforcement is fixed between the bottom frame portion 11 and the guide post 15. The bottom frame portion 11 has a U-shape so that the loading platform 50 can land, and casters 5 are attached to the front and rear bottom surfaces of the side surface portions 11a along both sides of the loading platform 50 of the bottom frame portion 11. There are a total of four casters 5, and two casters on the front side or the rear side can change direction. Further, in order to stop the main body frame 10, two casters 5 on the front side or the rear side are provided with a stop mechanism.

As shown in FIGS. 4A, 4B, and 4C, the guide post 15 has a hollow square cylinder shape, and the roller guides 16 are vertically opposed to each other in the elevating range of the runner 30. It is stuck to. A vertical slit 15a for guiding the runner 30 up and down is formed on the front wall of the guide post 15. A roller 31 is rotatably attached to a portion of the runner 30 that has entered the inside of the guide post 15. As the roller 31 rolls on the inner surface of the roller guide 16, the runner 30 can smoothly move up and down with respect to the guide post 15.

The runner 30 extends to the outside of the guide post 15 through the vertical slit 15a, and the load receiving base 50 is horizontally fixed to the lower portion of the portion extending to the outside. In other words, the loading platform 50 is fixed to the runner 30 so as to be in a vertical position with respect to the guide post 15. Side guards 51, which both prevent and reinforce the cargo from falling, are fixed to both sides of the cargo receiving platform 50. The lower end of the side guard 51 is fixed to the side surface of the loading platform 50, and the rear end of the side guard 51 is fixed to the upper end of the runner 30. Front doors 52A and 52B with double doors are hingedly attached to the side guards 51 on both the left and right sides so as to be openable and closable. The front doors 52A and 52B can be locked in a closed state by the door lock mechanism 53.

A caster stopper 60 is rotatably connected to the front edge of the load receiving table 50 by a pin 61. In the non-landing position where the load receiving table 50 rises from the ground, the caster stopper 60 comes into contact with the regulating member 50a (provided at the side end of the load receiving table 50) on the load receiving table 50 side by its own weight. The trailing edge portion 60a protrudes from the upper surface 50b of the loading platform 50. Therefore, the trailing edge portion 60a of the caster stopper 60 protrudes from the upper surface of the load receiving table 50 from the position where the load receiving table 50 slightly rises from the ground to the ascending limit position U in FIG. You can prevent falling. In the landing state D of the load receiving table 50, the caster stopper 60 forms an upper surface continuous with the load receiving table 50, so that the trolley or the like can be easily carried onto the load receiving table 50.

Brackets 54 are erected and fixed on both sides of the upper surface of the trailing edge of the loading platform 50. As shown in FIG. 5, the transfer plate 70 integrally has a small arm 71, and the small arm 71 is rotatably connected to the bracket 54 by a pin 72. As a result, the transfer plate 70 is urged to rotate in the deployment direction so as to be substantially flush with the load receiving table 50 due to its own weight. When the transfer plate 70 is horizontally deployed as shown in position Q of FIG. 1, the transfer plate 70 is substantially flush with the cargo bed 50, and the transfer plate 70 is placed on the gap between the platform of the freight vehicle or the warehouse and the cargo bed 50. It will be handed over. As a result, cargo handling using a trolley or the like can be smoothly performed.

A guide mechanism 75 is provided as shown in FIG. 5 in order to automatically raise the transfer plate 70 while the load receiving table 50 is descending from the ascending limit position U in FIG. 1 toward the landing position D (that is, the descending limit position). ing. The guide mechanism 75 is rotatably attached to a reinforcing frame on the lower side of the transfer plate 70, although details are omitted, the roller 76 is pivotally supported by the transfer plate 70 so as to project from one side surface of the transfer plate 70. ) And a guide member 77 with which the roller 76 comes into contact. The guide member 77 has a substantially inverted L shape with rounded corners and is fixed to the inner side surface of the guide post 15 (the surface on which the left and right guide posts 15 face each other). As the load receiving table 50 descends, the roller 76 comes into contact with the contact surface (upper surface) of the guide member 77, and as the load receiving table 50 further descends, the load receiving table 50 rotates clockwise in FIG. That is, the load receiving table 50 is rotated in the upright direction, and then the load receiving table 50 can descend to the landing position in an upright state along the back guard 13 on the guide post 15 side.

As shown in FIGS. 2 and 7 (A) and 7 (B), a transfer plate locking mechanism 55 for locking the transfer plate 70 in a state of standing vertically with respect to the upper surface of the load receiving table 50 is provided. The transfer plate lock mechanism 55 has a bracket 56 and a spring pin 57 provided on the side guard 51 side, and an engaging member 59 fixed to the transfer plate 70 side. The bracket 56 is fixed to the side guard 51, and the spring pin 57 penetrates the bracket 56. The spring pin 57 is urged by the compression spring 58 in a direction (downward) to be fitted into the engaging hole 59a of the engaging member 59. After pulling up the ring-shaped operation portion 57a on the upper part of the spring pin 57 to align the lower end portion of the spring pin 57 with the engaging hole 59a, the spring pin 57 is released and the lower end portion of the spring pin 57 becomes the engaging hole 59a. By engaging, the transfer plate 70 can be locked in a vertically upright state. Further, the lock can be released by pulling up the ring-shaped operating portion 57a to disengage the lower end of the spring pin 57 from the engaging hole 59a.

One end of the raising strap 79 is fixed to the upper surface of the transfer plate 70. By manually pulling the raising strap 79, the transfer plate 70 can be erected at an arbitrary height position of the loading platform 50. At this time, when the spring pin 57 of the transfer plate locking mechanism 55 hits the engaging member 59, the rotation range of the transfer plate 70 is limited to the range in which the transfer plate 70 stands upright from the unfolded state with respect to the load receiving table 50.

In FIGS. 1 to 3, 6 and 8, a lift drive mechanism 80 for raising and lowering a runner 30 that moves up and down in the guide post 15 and a load receiving base 50 that moves integrally with the runner 30 will be described. The lifting drive mechanism 80 includes a single-acting hydraulic cylinder set 90A, 90B for raising and lowering, which are housed in the left and right (pair) guide posts 15, a hydraulic circuit 100 for driving the hydraulic cylinder sets 90A, 90B, and a flood control. It has a power unit 130 as a hydraulic source for supplying hydraulic oil to the circuit 100.

As shown in FIG. 6, in the single-acting hydraulic cylinder sets 90A and 90B for raising and lowering, the hydraulic cylinders 90A-1, 90A-2 and 90B-1, 90B are paired so that the piston rods 92 are opposite to each other. The main body 91 of -2 is integrated by welding or the like so that the height positions of the main bodies 91 overlap each other. Further, in the hydraulic oil pipe 140 from the hydraulic circuit 100, the piston rod 92 contracts when the hydraulic oil is supplied to the main bodies 91 of the paired hydraulic cylinders 90A-1, 90A-2 and 90B-1, 90B-2. It is provided to do so. As shown in FIG. 4A, the upper end of one of the piston rods 92 of the single-acting hydraulic cylinder sets 90A and 90B for elevating and lowering is connected (centered) to the guide post 15 by a pin 95. The arrangement of the hydraulic cylinders 90A-1 and 90A-2 constituting the hydraulic cylinder assembly 90A and the hydraulic cylinders 90B-1 and 90B-2 constituting the hydraulic cylinder assembly 90B in the guide post 15 is shown in FIG. 4 (B). .. The lower end of the other piston rod 92 of the hydraulic cylinder sets 90A and 90B is connected to the lower end of the runner 30 by a pin 93 as shown in FIG. 4C. Therefore, the load receiving table 50 is in the lowered position when the piston rods 92 of the hydraulic cylinder sets 90A and 90B in opposite directions are extended, and the load receiving table 50 is in the raised position when the hydraulic cylinder sets 90A and 90B are contracted.

As shown in FIG. 8, the power unit 130 serving as a hydraulic source for the single-acting hydraulic cylinder sets 90A and 90B for raising and lowering is a motor M connected to the battery BT via a main switch S and a pump rotationally driven by the motor M. It has 135 and an oil tank 131 containing hydraulic oil. The hydraulic circuit 100 that connects the power unit 130 and the single-acting hydraulic cylinder sets 90A and 90B has a block 110 having an electromagnetic switching valve 111 and a block 120 having a pair (two) tuning valves 121A and 121B. There is. As shown in FIG. 2, the battery BT, the hydraulic circuit 100, and the power unit 130 are mounted on the mounting base 11b of the bottom frame portion 11. Further, for operation control of the mobile lift 1, that is, operation control of the lifting hydraulic cylinder sets 90A and 90B, a control panel (including a battery charger) 48 is arranged on the side surface of the guide post 15 as shown in FIG. In addition, a wired remote switch box 49 is detachably provided on the side holder of the control panel 48.

The block 110 of the hydraulic circuit 100 is a check valve (check valve) 115 that supplies the hydraulic oil pumped from the oil tank 131 by the pump 135 to the block 120 having the tuning valves 121A and 121B via the port P, and the port. It has a relief valve 116 that returns the hydraulic oil to the oil tank 131 via the port T when the pressure of P exceeds a constant pressure, and a series connection of the electromagnetic switching valve 111 and the throttle valve 117. The electromagnetic switching valve 111 and the throttle valve 117 connect the port T and the block 120.

The pair of tuning valves 121A and 121B of the block 120 are collecting valves, and the hydraulic oil flow rates in the sending and returning directions of the hydraulic oil in both tuning valves 121A and 121B are evenly matched.

In the configuration of the above embodiment, when the hydraulic oil of the pair of single-acting hydraulic cylinder sets 90A and 90B for raising and lowering in the lifting drive mechanism 80 is returned to the oil tank 131 of the power unit 130, the pistons of the cylinder sets 90A and 90B are returned. The rod 92 is in the most extended state, the runner 30 is at the lowermost position, and the loading platform 50 is at the landing position (lowering limit position) of the virtual line D in FIG.

By operating the remote switch box 49, the main switch S is closed, the power unit 130 is operated, and the pump 135 operates the left and right (pair) single-acting hydraulic cylinder sets 90A and 90B via the pair of tuning valves 121A and 121B, respectively. When oil is supplied, the piston rods 92 of the cylinder sets 90A and 90B are contracted, and the runner 30 is pulled up. Then, the runner 30 and the consignment pedestal 50 can be raised to the ascending limit position U in FIG. In the ascending operation of the load receiving table 50, the pair of tuning valves 121A and 121B evenly divide and supply the hydraulic oil to the left and right cylinder sets 90A and 90B, so that the load receiving table 50 is not tilted.

The load receiving table 50 can be stopped at an arbitrary height in front of the ascending limit position U according to the height of the other party to which the load is transferred.

At this time, if the transfer plate 70 is locked in the upright state by the transfer plate lock mechanism 55, the transfer plate 70 can maintain the upright state and ascend to the ascending limit position U together with the load receiving table 50. Then, the transfer plate lock mechanism 55 may be unlocked at the ascending limit position U or an arbitrary stop position in front of the ascending limit position U, and the transfer plate 70 may be deployed in the horizontal direction. When the lock is released, the transfer plate 70 is deployed by its own weight.

On the other hand, when the transfer plate 70 is not locked by the transfer plate lock mechanism 55, the transfer plate 70 is maintained in an upright state along the back guard 13 on the main body frame 10 side from the landing position of the load receiving base 50 to the ascending position in the middle, and thereafter FIG. The roller 76 is brought into contact with the guide member 77 of the guide mechanism 75 of the above, and is guided, and the transfer plate 70 expands in the horizontal direction as the load receiving table 50 rises.

When lowering the cargo receiving platform 50 from the ascending limit position U in FIG. 1 toward the landing position (descending limit position) of the virtual line D, the main switch S is opened by operating the remote switch box 49, and the power unit 130 is stopped (pump). (135 is stopped), the electromagnetic switching valve 111 is excited, and the hydraulic oil is returned to the oil tank 131 via the port T in the path of the throttle valve 117 and the electromagnetic switching valve 111. As a result, the piston rods 92 of the cylinder sets 90A and 90B in opposite directions extend, and the runner 30 descends until the load receiving base 50 reaches the landing position of the virtual line D. At this time, since the pair of tuning valves 121A and 121B collect the hydraulic oil from the left and right cylinder sets 90A and 90B in an equal amount and return it to the oil tank 131, the load receiving table 50 is not tilted.

By stopping the return of the hydraulic oil in the middle, it is possible to stop the load receiving table 50 at a position higher than the landing position according to the cargo handling conditions.

When the transfer plate 70 is not locked by the transfer plate lock mechanism 55, as the load receiving table 50 descends, the roller 76 of the guide mechanism 75 in FIG. 5 comes into contact with the contact surface of the guide member 77, and the load receiving table 50 is further contacted. As the lowering of the load receiving table 50, the load receiving table 50 rotates clockwise in FIG. That is, the load receiving table 50 is rotated in the upright direction, and then the load receiving table 50 can descend to the landing position in an upright state along the back guard 13 on the guide post 15 side.

According to this embodiment, the following effects can be obtained.

(1) The mobile lift 1 has a configuration in which a load receiving base 50 having a caster stopper 60 and a transfer plate 70 connected to a main body frame 10 to which wheels (casters 5) are attached and movable is provided so as to be able to move up and down. It can be used for various cargo handling operations. For example, it is not limited to cargo handling using pallets, and efficient cargo handling such as cargo handling between the cargo bed and the ground of a freight vehicle not equipped with a loading platform lifting device, and cargo handling work between the ground and warehouse platforms. It is feasible.

(2) The elevating drive mechanism 80 that elevates and drives the load receiving base 50 is a hydraulic circuit that drives the single-acting hydraulic cylinder sets 90A and 90B and the cylinder sets 90A and 90B, which are housed in the left and right (pair) guide posts 15, respectively. It has 100 and a power unit 130 for supplying hydraulic oil to the hydraulic circuit 100, and the hydraulic circuit 100 transmits the hydraulic oil flow rate in the delivery and return directions of the hydraulic oil to the left and right (pair) cylinder sets 90A and 90B. It has tuning valves 121A and 121B that are evenly aligned. Since the runner 30 and the loading platform 50 are directly moved up and down by the left and right (pair) cylinder sets 90A and 90B, the mechanism of the lifting drive mechanism 80 is simple and highly reliable, and the loading platform 50 tilts during the lifting operation. There is no.

(3) The caster stopper 60 has a configuration in which the trailing edge portion 60a protrudes from the upper surface of the load receiving table 50 due to its own weight at the non-landing position of the load receiving table 50, and the mechanism of the caster stopper 60 can be simplified.

(4) The transfer plate 70 can be automatically raised and unfolded by the guide mechanism 75. Therefore, for example, even when the load receiving table 50 is lowered while the transfer plate 70 is deployed at the raised position of the load receiving table 50, it is possible to prevent the transfer plate 70 from colliding with the horizontal frame portion 12.

(5) Instead of one long-stroke hydraulic cylinder, hydraulic cylinder sets 90A and 90B in which the main bodies of the paired hydraulic cylinders are integrated are provided on the left and right (pair) guide posts 15, respectively. The total length of the 15 can be shortened, and the height of the mobile lift 1 can be reduced.

Although the present invention has been described above by taking the embodiment as an example, it will be understood by those skilled in the art that various modifications can be made to each component and each processing process of the embodiment within the scope of the claims. By the way.

In the above embodiment, a set of hydraulic cylinders in which the main bodies of the pair of hydraulic cylinders are integrated is provided on each of the left and right (pair) guide posts so that the piston rods are oriented in opposite directions. One long-stroke hydraulic cylinder may be provided instead of the set.

1 Mobile lift 5 Caster 10 Main body frame 12 Horizontal frame part 15 Guide post 30 Runner 31, 76 Roller 50 Loading platform 55 Passing plate lock mechanism 60 Caster stopper 70 Passing plate 75 Guide mechanism 77 Guide member 80 Lifting drive mechanism 90A, 90B Lifting Single-acting hydraulic cylinder set 100 Hydraulic circuits 121A, 121B Tuning valve 130 Power unit

Claims (5)

A main body frame having a pair of guide posts and a horizontal frame portion arranged between the pair of guide posts.
Wheels that movably support the main body frame and
A runner provided on each of the pair of guide posts so that it can be raised and lowered,
The consignment stand fixed to the lower part of the runner,
The runner and the elevating drive mechanism for elevating and driving the consignment stand are provided.
The elevating drive mechanism has a hydraulic cylinder housed in a pair of guide posts, a hydraulic circuit for driving the hydraulic cylinder, and a power unit for supplying hydraulic oil to the hydraulic circuit, and one end of the hydraulic cylinder. The portion is connected to the guide post, and the other end is connected to the runner.
The hydraulic circuit is a mobile lift characterized by having, for all the hydraulic cylinders, a tuning valve that evenly aligns the hydraulic oil flow rates in the feed and return directions of the hydraulic oil. The caster stopper is rotatably provided on the front edge side of the cradle, and the trailing edge of the caster stopper protrudes from the upper surface of the cradle due to its own weight at the non-landing position of the cradle. Mobile lift as described in. The first aspect of the present invention, wherein the transfer plate is rotatably provided on the trailing edge side of the load receiving table, and has a guide mechanism for raising the transfer plate in the deployed state while the load receiving table is descending from a predetermined rising position. Or the mobile lift according to 2. The mobile lift according to claim 3, wherein the guide mechanism has a roller attached to a side portion of the transfer plate and a guide member fixed to the guide post and in contact with the roller. The movement according to any one of claims 1 to 4, wherein instead of the hydraulic cylinder, a hydraulic cylinder set in which the main bodies of the pair of hydraulic cylinders are integrated so that the piston rods are opposite to each other is used. Ceremony lift.