JPH0820495A - Lift device - Google Patents

Abstract

PURPOSE:To simplify synchronous drive mechanisms and control for forming a lift device compact by providing a motor between a pair of cam plates, and synchronizing and driving both link mechanisms through a drive transmission device. CONSTITUTION:A pair of a front and back scissors type link devices 20 are provided between a base frame 18 and an elevation frame, a roller 30 is provided on a first link 21 of both link devices 20, the base frame 18 has an up- directed inclination surface to be engaged with the roller 30, and cam plates 33 which are movable right and left are provided. Both cam plates 33 are connected to each other by a connection material 42, and a spiral shaft 44 to be engaged with a nut body 43 to move the connection material 42 right and left, and a speed reducer 45 and a motor 46 connected directly at one end of it are disposed. As the motor 45 is driven, drive force is transmitted through a drive transmission device 50 to both can plates 33, each roller 30 is pushed up along an inclination surface 36 of the cam plate 33, the first link 21 and a second link 22 are rotated upward respectively, and the elevation frame 19 is lifted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lifting device for raising and lowering a load.

[0002]

2. Description of the Related Art Conventionally, a lift device of this type is disclosed in, for example, Japanese Patent Laid-Open No. 3-51297.
That is, a total of four pairs of scissor-shaped left and right link mechanisms for raising and lowering the table are provided between the base and the table. Each link mechanism is formed by two links that intersect each other at the center, and a roller is provided below one of the links. On the base side, a cam plate having an upward inclined surface engageable with each roller and movable in the front-rear direction, and a hydraulic cylinder device for individually moving the cam plates are provided. There is.

According to this, each hydraulic cylinder device operates and each cam plate synchronously moves to one side, whereby each roller is pushed up along the inclined surface of the cam plate and each link mechanism operates. To raise the table. Further, by operating each hydraulic cylinder device and moving each cam plate in synchronization with each other,
Each roller moves downward along the inclined surface of the cam plate, and each link mechanism operates to lower the table.

[0004]

However, in the above-mentioned conventional type, when the table is moved up and down, the pair of left and right link mechanisms must be driven synchronously by the individual hydraulic cylinder devices. There is a problem that the mechanism and control become complicated. Further, since two hydraulic cylinder devices for driving must be provided between the pair of left and right link mechanisms, the lift device becomes large. Furthermore, there is a concern that oil may leak from the hydraulic cylinder device.

The present invention solves the above problems, and provides a lift device that can drive both link devices synchronously with a simple mechanism and is compact and capable of preventing oil leakage problems. It is intended.

[0006]

In order to solve the above problems, a lift device according to the first aspect of the present invention is a scissor including a first link and a second link that intersect each other in the center between a base frame and a lifting frame. A pair of elevating and lowering link devices are provided, rollers are provided at the lower portions of both the first links, and the base frame has an upward inclined surface capable of engaging with the both rollers. A cam plate that can move laterally in the length direction is provided, and an electric motor that drives both cam plates synchronously is provided between these cam plates.
A drive transmission device that transmits the driving force of the electric motor to both cam plates is provided between the electric motor and both cam plates.

In the lift device according to the second aspect of the present invention, the drive transmission device includes a connecting member for connecting the two cam plates, a nut body provided on the connecting member, and a connecting member which is screwed to the nut body. The first and second links are composed of a rotatable spiral shaft for lateral movement in the longitudinal direction, and a speed reducer directly connected to one end of the spiral shaft. An electric motor is connected to the speed reducer.

In the lift device according to the third aspect of the present invention, the inclined surface of the cam plate is formed into a downwardly curved arc-shaped curve.

[0009]

According to the structure of the first invention, when the electric motor is driven, its driving force is transmitted to both cam plates through the drive transmission device, so that both cam plates are synchronously moved to one side. Moving. As a result, each roller is pushed up along the inclined surface of each cam plate, so that the first link and the second link rotate upward, respectively, and the elevating frame rises. On the contrary, when the electric motor is reversely driven, both cam plates synchronously laterally move to the other, so that each roller moves downward along the inclined surface of each cam plate. Link and second
The link and the pivot respectively rotate downward, and the elevating frame descends.

As described above, one electric motor is provided between the cam plates, and between the electric motor and the cam plates,
Since the drive transmission device that transmits the driving force of the electric motor to both cam plates is provided, both link devices can be driven synchronously by one electric motor, and the mechanism and control for the synchronous drive are simplified, and the lift is further increased. The device can be made compact.
Further, since the electric motor is used as the drive device, there is no concern about oil leakage.

According to the structure of the second invention, when the electric motor is driven, its driving force is transmitted to the spiral shaft through the speed reducer, and the spiral shaft rotates in one direction. Therefore, the nut body is fed by the screw, and the connecting member laterally moves to one side, so that both cam plates synchronously laterally move to one side. As a result, both link devices are driven in synchronization and the lifting frame is raised.

On the contrary, when the electric motor is driven in the reverse direction, the spiral shaft rotates in the other direction, the nut body is fed by the screw, and the connecting member moves laterally to the other side. Move sideways to the other in sync. As a result, both link devices are synchronously driven to lower the elevating frame.

Thus, since both link devices can be driven synchronously with one electric motor and a simple mechanism,
The lift device can be made compact and the cost can be reduced. According to the configuration of the third invention, when the cam plate laterally moves and pushes up the roller on the inclined surface, the push-up angle is gentle at first, and then the push-up angle becomes gradually steep when the momentum increases. The rollers are pushed up all at once. Therefore, the roller can be pushed up smoothly with a small force, and the torque of the electric motor can be reduced.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. As shown in FIGS. 5 and 6, reference numeral 1 denotes an automatic warehouse, which is composed of a pair of shelves 2a and 2b and a loading / unloading device 4 that can travel along a traveling path 3 formed between the shelves 2a and 2b. There is. The loading / unloading device 4 is mounted on a traveling machine body 5, a carriage 7 provided on the traveling machine body 5 via a post 6 so as to be movable up and down, and a storage unit 8 of the shelves 2a and 2b. It is composed of a retractable fork 9.

On the outside of the end of one of the shelves 2a, there is installed a material handling device 11 on which the fork 9 of the loading / unloading device 4 can freely operate. The handling device 11 is of a conveyor type in which the direction along the travel route 3 is the transport direction, and
12 and a pair of drive chains 13 arranged on the machine frame 12 side
A first lift device 14 disposed between the drive chains 13 and at the end on the shelf 2a side, and a second lift device 15 disposed at the end on the side away from the shelf 2a. Has been done.

The structure of the first lift device 14 will be described below. That is, as shown in FIG. 1 and FIG. 2, a base frame 18 is provided between the pair of left and right machine frames 12 of the material handling device 11.
Are attached to the front and back. These base frames 18
An elevating frame 19 is provided above each of the drive chains 13 so as to be able to elevate between the upper level and the lower level of the both drive chains 13. A link device 20 for raising and lowering the elevating frame 19 is provided between the base frame 18 and the elevating frame 19 which face each other in the vertical direction. These link devices
Each 20 is formed in a scissor shape from a first link 21 and a second link 22 that intersect at the center.

The lower end of the first link 21 is rotatably connected to one end of the base frame 18 via a horizontal pin 23, and the upper end of the first link 21 is connected to the other side of the elevating frame 19 via a roller 24. It is engaged with the end so that it can be displaced in the left-right direction. In addition, the upper end of the second link 22 is provided with a horizontal pin 25 to raise and lower the frame.
The second link 22 is rotatably connected to one end of the base frame 19, and the lower end of the second link 22 is engaged with the other end of the base frame 18 via a roller 26 so as to be displaceable in the left-right direction. In addition, the first link 21 and the second
The intersection with the link 22 is connected by a pin 27.

Rollers 30, which are freely rotatable around a front-rear axis 29, are provided on the lower surfaces of the first links 21 and the front and rear surfaces facing each other through a support shaft 31. Each of the base frames 18 is provided with a cam plate 33 that is supported and guided by a rail 32 and is movable in the left and right directions. The rail 32 is formed in a channel shape whose upper surface is open. At the bottom of the cam plate 33,
Support roller fitted in 32 and supporting cam plate 33
34 and a guide roller 35 which is fitted into the rail 32 and guides the cam plate 33 are provided.

An upward inclined surface 36 engageable with the roller 30 is formed on one side of each of the cam plates 33, and an upper horizontal surface 37 extends from the upper end of the inclined surface 36 toward the other side. And a lower horizontal surface 38 is provided continuously from the lower end of the inclined surface 36 toward one side. The upper horizontal surface 37 is formed lower than the other side portion of the cam plate 33 by one step. In addition, a pair of left and right stoppers 39a, 39 for limiting the moving range of each cam plate 33 are provided on both rails 32, respectively.
b is provided.

The two cam plates 33 are connected by a connecting member 42, and a nut body 43 is provided at an intermediate portion of the connecting member 42. Further, a rotatable spiral shaft 44 for screwing the nut body 43 to move the connecting member 42 in the left-right direction is provided in the left-right direction between the cam plates 33, and one end of the spiral shaft 44 is provided at one end thereof. The speed reducer 45 is directly connected. Further, an electric motor 46 for rotating the spiral shaft 44 is connected to the speed reducer 45.
The spiral shaft 44 is rotatably supported by a bearing device 47, and the bearing device 47 is supported by a support frame 48 provided between both base frames 18. The speed reducer 45 is supported by the support frame 48 via the bracket 49. The connecting member 42, the nut body 43, the spiral shaft 44, and the speed reducer 45 are an example of a drive transmission device 50 that transmits the drive force of the electric motor 46 to the cam plates 33. Also, the above spiral axis
44 is covered with a bellows-like dust-proof cover 51 that can expand and contract in the axial direction of the spiral shaft 44.

The second lift device 15 has the same structure as the first lift device 14. The operation of the first lift device 14 will be described below. When the electric motor 46 is driven, the spiral shaft 44 rotates in one direction and the connecting member 42 is sent to one side,
Both cam plates 33 synchronously move to one side. As a result, both rollers 30 are pushed up from the lower horizontal surface 38 of each cam plate 33 along the inclined surface 36 in the order of FIG. 4 to FIG. 2, so that the first link 21 and the second link 22 rotate upward respectively. Both lifting frames 19 move up. Then, as shown in FIG. 2, both rollers 30 reach the upper horizontal surface 37 of each cam plate 33, and both lifting frames 19 are held at the upper limit position H. At this time, the load 54 placed on both lifting frames 19
Load of both rollers 30, both cam plates 33, and both rails 32
It is supported by both base frames 18 via. Further, when both the elevating frames 19 reach the upper limit position H, each cam plate 33 comes into contact with one stopper 39a and stops, so that the upper limit position H can be accurately positioned.

When the electric motor 46 is reversely driven, the spiral shaft 44 rotates in the other direction, the connecting member 42 is sent to the other side, and both cam plates 33 move to the other side in synchronization. .
As a result, both rollers 30 move downward from the upper horizontal surface 37 of each cam plate 33 along the inclined surface 36 in the order of FIGS. 2 to 4, so that the first link 21 and the second link 22 respectively move downward. It rotates and both the elevating frames 19 descend. Then, as shown in FIG. 4, both rollers 30 reach the lower horizontal surface 38 of each cam plate 33, and both lifting frames 19 are held at the lower limit position L. When both the elevating frames 19 reach the lower limit position L, the guide rollers 35 of each cam plate 33 come into contact with the other stopper 39b and stop, so that the lower limit position L can be accurately positioned.

The operation of the second lift device 15 is the same as that of the first lift device 14. Therefore, in the automated warehouse 1, the loading and unloading device 4 has the traveling machine body 5 as shown in FIG.
Along the traveling route 3 of, and the raising and lowering of the carriage 7,
Due to the combined movement of the fork 9 with the lateral movement, the shelf 2
The load 54 can be loaded / unloaded into / from the intended storage portion 8 of a and 2b.

The loading / unloading device 4 is the first lift device.
It is stopped facing 14 and the fork 9 projects laterally so that the load 54 can be delivered to and from the first lift device 14. At this time, both the elevating frames 19 of the first lifting device 14 are raised to the upper limit position H as shown in FIG. 2, and the load 54 is placed on the both elevating frames 19. After that, as shown in FIG. 4, both lift frames 19 are lowered to the lower limit position L, so that the load 54 is supported on both drive chains 13, and both drive chains 13 are driven to load the load 54. 11 is transported to the second lift device 15 side.

In the above embodiment, as shown in FIG. 5, the material handling device 11 is installed outside the end of one shelf 2a, but the material handling device 11 is installed outside the end of the other shelf 2b. You may.
In addition, the load 54 directly lifts the lifting frames 19 of the lifting devices 14 and 15.
Although it is mounted on the drive chain 13 or the drive chain 13, it may be mounted via a pallet.

The second embodiment of the present invention will be described below with reference to FIG. That is, the inclined surface 60 of the cam plate 33 is formed in an arcuate curve that is curved downward. According to this, when the cam plate 33 moves to one side and pushes up the roller 30 on the inclined surface 60, the push-up angle is gentle at first, and then the push-up angle gradually increases when the momentum increases. Then the roller 30 is pushed up all at once. Therefore, the roller 30 can be pushed up smoothly with a small force, and the torque of the electric motor 46 can be reduced.

A third embodiment of the present invention will be described below with reference to FIGS. The drive transmission device according to the first embodiment described above.
50 (see FIG. 1) is of a type using a spiral shaft 44, but the drive transmission device 65 of the third embodiment is of a type using a rack and a pinion. That is, both cam plates 33
Racks with teeth on the upper surface on the lower inner side facing each other
66 are provided in the left and right directions, respectively. Pinions 67 that mesh with the racks 66 are provided above the racks 66, respectively. A speed reducer 68 is provided between the both pinions 67, and the speed reducer 68 and the both pinions 67 are connected by a front-rear rotating shaft 69 penetrating the speed reducer 68. An electric motor 46 is directly connected to the speed reducer 68. The speed reducer 68 and the electric motor 46 are a pair of front and rear base frames.
It is supported by a support bracket 70 provided between 18 parts.

According to this, when the electric motor 46 is driven, both the pinions 67 rotate in one direction via the speed reducer 68 and the rotary shaft 69, and the rotation of both the pinions 67 causes the two racks 66 to move laterally. And both cam plates 33 are synchronously moved to one side. Therefore, the first link 21 and the second link 22
And, respectively, rotate upward, and both the elevating frames 19 rise.

When the electric motor 46 is driven in reverse, both pinions 67 rotate in the other direction via the speed reducer 68 and the rotary shaft 69, and the rotation of both pinions 67 causes both racks to rotate.
66 is sent in the lateral direction, and both cam plates 33 move to the other side in synchronization. As a result, the first link 21 and the second link 22 rotate downward, respectively, and the both elevating frames 19 descend.

In the third embodiment, the rack 66 and the pinion 67 are used instead of the spiral shaft 44 and the nut body 43 of the first embodiment (see FIG. 1), so that the cost can be reduced. In addition, in the first embodiment, when moving the cam plate 33,
Since a large load acts on the connecting member 42, the connecting member 42 tends to increase in size in terms of strength. However, in the third embodiment, since the connecting member 42 is not used, the drive transmission device 65 is downsized. Is possible.

[0031]

As described above, according to the first aspect of the present invention, when the electric motor is driven, its driving force is transmitted to both cam plates via the drive transmission device, so that both cam plates are synchronized. Then move to one side. As a result, each roller is pushed up along the inclined surface of each cam plate, so that the first link and the second link rotate upward, respectively, and the elevating frame rises. On the contrary, when the electric motor is reversely driven, both cam plates synchronously laterally move to the other, so that each roller moves downward along the inclined surface of each cam plate. The link and the second link rotate downward, respectively, and the elevating frame descends.

As described above, one electric motor is provided between both cam plates, and between this electric motor and both cam plates,
Since the drive transmission device that transmits the driving force of the electric motor to both cam plates is provided, both link devices can be driven synchronously by one electric motor, and the mechanism and control for the synchronous drive are simplified, and the lift is further increased. The device can be made compact.
Further, since the electric motor is used as the drive device, there is no concern about oil leakage.

According to the second aspect of the present invention, when the electric motor is driven, its driving force is transmitted to the spiral shaft via the speed reducer, and the spiral shaft rotates in one direction. Therefore, the nut body is fed by the screw, and the connecting member laterally moves to one side, so that both cam plates synchronously laterally move to one side. As a result, both link devices are driven in synchronization and the lifting frame is raised.

On the contrary, when the electric motor is driven in the reverse direction, the spiral shaft rotates in the other direction, the nut body is fed by the screw, and the connecting member moves laterally to the other side. Move sideways to the other in sync. As a result, both link devices are synchronously driven to lower the elevating frame.

In this way, both link devices can be driven synchronously with one electric motor and a simple mechanism.
The lift device can be made compact and the cost can be reduced. According to the third aspect of the present invention, when the cam plate laterally moves and pushes up the roller on the inclined surface, the push-up angle is gentle at first and then the push-up angle becomes gradually steep when the momentum increases. The rollers are pushed up all at once. Therefore, the roller can be pushed up smoothly with a small force, and the torque of the electric motor can be reduced.

[Brief description of drawings]

FIG. 1 is a partially cutaway plan view of a lift device according to a first embodiment of the present invention.

FIG. 2 is a front view of the lift device that has been raised to an upper limit position.

FIG. 3 is a front view of a lift device that supports a load at the same level as a drive chain.

FIG. 4 is a front view of the lift device lowered to a lower limit position.

FIG. 5 is a plan view of an automated warehouse using a lift device.

FIG. 6 is a side view of an automated warehouse using a lift device.

FIG. 7 is a diagram showing a shape of an inclined surface of a cam plate of a lift device according to a second embodiment of the present invention.

FIG. 8 is a partially cutaway plan view of a lift device according to a third embodiment of the present invention.

FIG. 9 is a diagram of a main portion of a drive transmission device of a lift device according to the third embodiment.

[Explanation of symbols]

 14,15 Lifting device 18 Base frame 19 Lifting frame 20 Link device 21 1st link 22 2nd link 30 Roller 33 Cam plate 36 Inclined surface 42 Connecting material 43 Nut body 44 Spiral shaft 45 Reducer 46 Electric motor 50 Drive transmission device 60 Inclination Surface 65 drive transmission

Claims (3)

[Claims] 1. A pair of scissor-like lifting link devices, each of which has a first link and a second link intersecting at the center, are provided between a base frame and a lifting frame, and rollers are provided below the first links. Provided on the base frame are cam plates each having an upwardly inclined surface capable of engaging with the rollers and movable laterally in the longitudinal direction of the first and second links, and between the cam plates. A lift device comprising an electric motor for synchronously driving both cam plates, and a drive transmission device for transmitting the driving force of the electric motor to both cam plates between the electric motor and both cam plates. 2. The drive transmission device includes a connecting member that connects the cam plates to each other, and a nut body provided on the connecting member.
It consists of a rotatable spiral shaft that is screwed to this nut body to move the connecting member laterally in the longitudinal direction of the first and second links, and a speed reducer directly connected to one end of this spiral shaft. The lift device according to claim 1, further comprising an electric motor connected to the machine. 3. The inclined surface of the cam plate is formed in a downwardly curved arc-shaped curve.
Alternatively, the lift device according to claim 2.