JP3708738B2 - lift device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lifting device that can be mounted on a vehicle carrier such as a trailer, and in particular, can accurately detect the vertical position of a mounting table on which a load is placed.
[0002]
[Prior art]
Conventionally, when loading / unloading a load from a vehicle, the vertical position of the loading table on which the load is loaded is electrically detected with an accuracy of about 1 mm in height, and the vertical position is controlled using the information to make smoother. There has been known a position detecting device for a lifting device capable of delivering a load.
[0003]
Examples of the position detection device include a device that measures the distance from a target using a laser beam as a sight, as described in Japanese Patent Laid-Open No. 8-226820, and a scale as described in Japanese Patent Laid-Open No. 9-5036. There was a device for optically detecting the length of the measuring scale by opening a slit.
[0004]
[Problems to be solved by the invention]
The above-mentioned conventional technology does not consider the dust resistance and durability when mounted on a vehicle or installed in a warehouse, and there are problems such as sensor sensitivity decrease due to dust and mud and clogging of slits. .
[0005]
An object of the present invention is to provide an elevating device that does not require maintenance for a long time, can detect the vertical position with high accuracy, and can be loaded on a vehicle.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, an elevating apparatus according to the present invention is provided with a base, a mounting base located on the upper side of the base, on which a load is placed, and a base provided between the base and the mounting base. A lifting device including a support unit that supports a mounting table on a table so that the mounting table can be moved up and down, and an actuator for moving the mounting table up and down. The support unit has one end rotatably supported at one point of the base. A first arm member whose other end is movably supported by the mounting table, and a second arm whose one end is rotatably supported by one point of the mounting table and the other end is movably supported by the base. An arm member is made to intersect with each other, and arm members fixed to each other at the intersection are arranged on both sides of the base and mounting table, and the actuator is operated on the first or second arm member. Let the mounting table move up and down with respect to the base Provided the position detecting device for detecting a vertical position of the placing table on the base, the position detecting device, a flexible the other end one end attached to the placing table is suspended rotating body and the movable pulley strip And position detecting means attached to these rotating bodies or moving pulleys to detect the amount by which the mounting table moves up and down from the moving amount of the belt, and means for pulling the moving pulley to apply a pulling force to the belt. To do .
[0008]
Further preferably, the means for pulling the moving pulley is a spring having a constant load with respect to the moving amount of the moving pulley.
[0009]
Still preferably, the position detecting means is an encoder.
[0011]
Since the vertical position of the mounting table is detected by the amount of rotation of the rotating body of the position detection device, there is no measurement error due to clogging or dirt, for example, when using a slit or an optical sensor.
[0012]
In addition, since the vertical displacement amount of the mounting table is transmitted by a flexible band, the durability of the position detection device is improved as compared with, for example, a measurement scale.
[0013]
Furthermore, since the flexible belt is stretched by the moving pulley, the stroke of the elastic body can be further shortened, and the apparatus can be downsized.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the lifting device according to the present invention will be described below with reference to the drawings.
FIG. 1 is a longitudinal sectional view of a first embodiment of a lifting device. In FIG. 1, a mounting table 2 on which a work device such as a construction machine is placed on the upper side of a base 1, and the mounting table 2 can be moved up and down on the base 1 by a support portion 3. It is supported.
[0015]
The support portion 3 is disposed so that the two arm members 4 and 5 intersect with each other, and is attached to the two arm members 4 and 5 through a shaft 6 so as to be rotatable with respect to each other. . In the present embodiment, metal plate-like members are used as the arm members 4 and 5. The inner arm members 5 are connected to each other via a shaft 6. Of the two arm members 4, 5 constituting the support portion 3, the arm member 4 outside the apparatus is rotatably attached to a bracket 8 provided in the mounting table 2 via a shaft 7. The lower end of the roller 9 is movably in contact with the base 1. The rollers 9 of the arm member 4 are coupled to each other via a connecting member 9a.
[0016]
On the other hand, the arm member 5 inside the apparatus has a lower end rotatably attached to the inside of the base 1 via the shaft 10, and an upper end movably contacting the base 1 by a roller 11.
The rollers 11 are coupled to each other via a connecting member 11a. The position detection device 12 is fixed to the base 1. A bracket 13 is attached to the lower part of the arm member 5, and an actuator 14 is attached to the bracket 13. The piston tip of the actuator 14 is fixed to a bracket 15 provided on the connecting member 5a inside the apparatus. FIG. 2 is a detailed view of the position detecting device 12 for detecting the vertical position of the mounting table 2. FIG. The configuration will be described.
A bracket 12A of the position detection device 12 is fixedly attached to the base 1, and a sprocket 16 is rotatably attached to the bracket 12A. Further, an absolute encoder 17 for measuring the rotation amount of the sprocket 16 is attached to the sprocket 16. A sprocket 18 is rotatably attached to a moving bracket 19, and this moving bracket 19 is attached to the bracket 12A so as to be slidable in the longitudinal direction, that is, in the horizontal direction in the figure. Moreover, the outer peripheral lower ends of the sprocket 16 and the sprocket 18 are arranged to be horizontal.
[0017]
Further, a sprocket 20 is attached to the bracket 12 </ b> A between the sprocket 18 and the sprocket 16. The outer peripheral upper ends of the sprocket 18 and the sprocket 20 are arranged to be horizontal. A sprocket 21 is attached to the moving bracket 19 between the sprocket 18 and the sprocket 19 and is slidably attached to the bracket 12A in the illustrated horizontal direction. The lower ends of the outer periphery of the sprocket 20 and the sprocket 21 are arranged to be horizontal.
[0018]
Further, a long hole 22 is formed in the bracket 12A, so that the sprocket 18 and the sprocket 21 can slide in the long hole 22 in the horizontal direction in the drawing.
[0019]
One end of the chain 23 is fixedly attached to a bracket 24 coupled to the mounting table 2, and is suspended in the order of the sprocket 16, the sprocket 18, the sprocket 20, and the sprocket 21, and the other end is fixed to the bracket 12A. The moving bracket 19 is pulled in the direction in which the chain 23 is stretched by the winding spring 25 attached to the bracket 12A. The control device 26 calculates an input signal to the actuator 14 from the deviation between the displacement detected by the position detection device 12 and the target displacement, and accurately controls the expansion / contraction operation amount of the actuator 14.
[0020]
In the lifting device having the above-described configuration, when the actuator 14 is expanded and contracted by a signal (not shown), the crossing angle θ of the two arm members 4 and 5 is increased or decreased via the ascending or descending of the shaft 6 as indicated by the chain line, Thereby, the mounting table 2 can be moved up and down.
[0021]
Further, the sprocket 16 rotates through the chain 23 as the mounting table 2 moves up and down, and the height, that is, the position of the mounting table 2 can be detected by detecting the amount of rotation by the absolute encoder 17. In addition, since the moving bracket 19 and the four sprockets 17, 18, 20 and 21 are used, the length of the position detection device can be reduced to ¼ of the vertical movement stroke of the mounting table 2, This makes it possible to reduce the size of the position detection device.
[0022]
In this embodiment, the position detection device 12 is configured to detect the vertical movement of the mounting table 2 by a combination of the chain 23 and the sprockets 17, 18, 20, and 21, but the timing is changed to these combinations. The same effect can be obtained by a combination of a belt and a timing pulley or a rope and a rope wheel. Further, although the winding spring 24 is used as a means for pulling the moving bracket 19 in this embodiment, the same effect can be obtained by using a spring or a coil spring instead.
[0023]
FIG. 3 is a longitudinal sectional view of a second embodiment of the lifting device.
The same parts as those in the first embodiment are denoted by the same reference numerals and the description thereof is omitted. However, the difference from the first embodiment is that the mounting position of the actuator 14 is changed.
[0024]
That is, the actuator 14 is attached to the base 1, and the mounting table 2 is supported by the tip of the actuator 14.
[0025]
Although not shown, a control device is provided for controlling the vertical position of the mounting table 2 based on the expansion / contraction operation or the rotation amount of the actuator 14 and the absolute encoder 17 as in the first embodiment.
[0026]
In the lifting device having the above-described configuration, the mounting table 2 can be moved up and down by the expansion and contraction operation of the actuator 14, and the same effect as the first embodiment can be obtained.
[0027]
【The invention's effect】
According to the present invention, it is difficult for measurement errors to occur even in work in a dusty or dusty place such as a warehouse or a vehicle, and therefore a highly reliable lifting device can be provided. In addition, since a highly durable material such as a chain or a timing belt is used to transmit the displacement amount, the durability of the lifting device is improved when used on a vehicle where vibration or force is applied.
[0028]
Furthermore, since the moving bracket to which the plurality of rotating bodies are coupled is pulled by the winding spring, the amount of movement of the rotating body of the position detecting device is reduced, and thereby the lifting device can be downsized.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a first embodiment of a lifting device according to the present invention.
FIG. 2 is a detailed view of the position detection apparatus of the embodiment of FIG.
FIG. 3 is a longitudinal sectional view of a second embodiment of the lifting device according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Base 2 ... Mounting base 3 ... Support part 4, 5 ... Arm members 6, 7, 10 ... Shafts 8, 11, 12A, 13, 15, 24 ... Brackets 9, 11 ... Rollers 9a, 11a ... Connecting member 12 ... Position detector 14 ... Actuators 16, 18, 20, 21 ... Sprocket 17 ... Absolute encoder 19 ... Moving bracket 23 ... Chain 25 ... Winding spring 26 ... Control device

Claims (3)

A base, a mounting base located on the upper side of the base, and a support base that is provided between the base and the mounting base and supports the mounting base on the base so as to be movable up and down; In the lifting device comprising the actuator for moving the mounting table up and down,
A first arm member having one end rotatably supported at one point of the base and the other end movably supported by the mounting table, and one end rotatably supported by one point of the mounting table. A second arm member whose other end is movably supported by the base and intersects with each other, and arm members fixed to each other at the intersection are arranged on both sides of the base and the mounting table. Configure
Actuating the actuator on the first or second arm member to move the mounting table up and down relative to the base;
A position detection device for detecting the vertical position of the mounting table is provided in the base ,
The position detecting device has a flexible band in which one end is attached to a mounting table and the other end is suspended from a rotating body and a moving pulley, and the mounting table is attached to the rotating body or moving pulley from the amount of movement of the band. An elevating apparatus comprising: position detecting means for detecting an amount of vertical movement; and means for pulling the movable pulley to apply a pulling force to the belt . It said means for pulling the movable pulley, the lifting device according to claim 1, characterized in that the spring load is constant with respect to the moving amount of the movable pulley. It said position detecting means, the lifting device according to claim 1, characterized in that the encoder.

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