JP2500593B2 - lift device - Google Patents

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 use in a place where cleanliness is required, such as a semiconductor production factory.

[0002]

2. Description of the Related Art As shown in a front view of FIG. 7 (a) and a side view of FIG. 7 (b), a conventional lifting device includes a load carrier 42 on which an object is placed and a guide 43 connected to the load carrier 42. , A guide rail 44, which is a track of the guide 43, and the cargo tray 4
2 and a weight equal to the weight of the guide 43, a counterweight 45.
And a chain 46 that connects the load receiving base 42 and the counterweight 45, and the sprocket 4 that supports the chain 46.
7, a linear motor 48 capable of moving the loading tray 42 along the guide rails 44, and a linear motor 48
And a controller 49 for controlling the position of the.

Next, the operation of the conventional device will be described.
The load receiving base 42 is stationary by a balance mechanism including a chain 46, a sprocket 47, and a counterweight 45 unless an external force is applied. Then, the load receiving base 42 can be moved up and down by the thrust of the linear motor 48. The linear motor 48 can use a thing with a small thrust by a balance mechanism.

[0004]

Since the above-mentioned conventional lifting device is composed of the chain and the sprocket of the balance mechanism, a large amount of dust is generated from the contact part between the chain and the sprocket that operates the device. There is.
Therefore, there is a problem that it cannot be used in a place requiring cleanliness such as a semiconductor factory. Particularly in semiconductor factories and the like, downflow keeps cleanliness, so it is fatal if there is a dust generation source in the upper part.

As a known technique, there is a method of casing the whole (Japanese Patent Laid-Open No. 61-192492), but it is expensive. Because the moving part moves in a straight line, a slit is always formed. In order to prevent dust from being generated from the slit, for example, a method of arranging a steel belt or the like with a minute gap from the slit is used, so that the mechanism is complicated. Further, since there is a mechanism for generating a large amount of dust inside the casing, there is a problem that dust is generated when the casing is opened during maintenance.

[0006]

The lifting device according to the present invention is U
Equipped with an elliptical tube that combines two upper and lower character tubes , the fluid is sealed in the lower half of this tube, pistons are placed on both open surfaces of the fluid, and a balance weight is placed on one piston. It has a balance mechanism and a guide mechanism for fitting the load receiving base to the linear portion of the oval tube and moving the load receiving base up and down using this linear portion as a guide, and magnets are embedded in the piston and the load receiving base, respectively. By maintaining the balance function via the magnetic force, the driving force for moving the loading tray up and down is reduced. As a result, the mechanical contact portion is reduced, and the dust source can be reduced.

[0007]

Next, the present invention will be described with reference to the drawings. FIG. 1 is a side view of the first embodiment of the present invention. Figure 2
FIG. 2 is a diagram showing a cross section taken along line AA of FIG. 1. FIG. 3 is an enlarged view of portion B in FIG.

The lifting device according to the first embodiment has an elliptic tube 1 in which two U-shaped tubes are vertically combined, a fluid 2 which fills the lower half of the inside of the tube 1, and one straight line of the tube 1. A piston 3 which is located inside the portion and which can receive the pressure of the fluid 2 and has a cylindrical shape, and which is fitted into the outer peripheral portion of the piston 3 and contacts the inner peripheral portion of the pipe 1 to seal the fluid 2 Packing 4, 5
And an internal magnet 6 that is also embedded and fixed in the outer peripheral portion of the piston 3, a load receiving base 7 that is movable together with the piston 3 and that fits into the outer peripheral portion of the pipe 1, and a position that faces the internal magnet 6 in a stationary state. External magnet 10 embedded and fixed in the cargo receiving stand 7
And the linear guides 11 and 12 that are in contact with the outer peripheral portion of one straight portion of the pipe 1 via a slide bearing and are fixed to the load receiving stand 7, and the outer peripheral portion of the other linear portion of the pipe 1 and the slide bearing. And the linear guides 13 and 14 fixed to the load receiving base 7 and the inside of the other straight portion of the pipe 1 and capable of applying pressure to the fluid 2 and having a cylindrical shape, and the piston 15. 15 Fitted on the outer periphery,
Inner packings 16 and 17 that come into contact with the inner peripheral portion of the pipe 1, a counterweight 18 placed on the piston 15, and a load receiving stand 7
It is configured to include a linear motor 19 that is capable of moving the load receiving base 7 in parallel with the linear portion of the pipe 1 and a controller 20 that controls the position of the linear motor. The fluid 2 may be liquid or gas.

Next, the balance function will be described.

The load of the load receiving table 7 and the weight of the external magnet 10 and the linear guides 11, 12, 13, 14 are transmitted to the internal magnet 6 by the magnetic force of the external magnet 10. Since the internal magnet 6 is fixed to the piston 3, the piston 3 applies pressure to the fluid 2. The applied pressure is transmitted through the fluid 2 and pushes up the piston 15 in the other straight portion. The balance weight 18 has a weight equivalent to the force for pushing up the piston 15. Therefore, the receiving table 7 is stationary unless external force is applied.

Next, the moving function will be described.

The thrust of the linear motor 19 is transmitted to the load receiving base 7 in a non-contact manner. The receiving platform 7 is a linear guide 11, 12,
It moves along the straight portion of the pipe 1 by the members 13 and 14. When stopping the loading platform 7 at an arbitrary position, the linear motor 19 is controlled by the controller 20.

As described above, when the load receiving base 7 is moved, the portions that generate dust are the linear guides 11, 12, 13, and 14 that come into contact with the outer peripheral portion of the pipe 1. However, since dust is minutely emitted from each portion, if a bone-removing agent such as low-evaporative grease is applied to the outer peripheral portion of the tube 1, it is possible to achieve a clean degree of about class 100. Furthermore, if a publicly known method of casing the whole is used, it is possible to achieve a clean degree of class 100 or higher. As described above, since the present embodiment has the balance function, it is possible to reduce the output of the linear motor, and since a part of the balance mechanism is used for the guide mechanism, the mechanism can be simplified.

Next, a second embodiment will be described. FIG. 4 is a side view of the second embodiment of the present invention. FIG. 5 is FIG.
It is the figure which showed the AA cross section. FIG. 6 is an enlarged view of portion C in FIG. The balance mechanism of the second embodiment has exactly the same mechanism and function as those of the first embodiment, and the description thereof will be omitted.

The lifting device of the second embodiment has a U-shaped tube 21 whose inside is sealed and a hole 2 formed in the upper portion of the U-shaped tube 21.
2, 23 and compressor 2 that can make compressed fluid
4 and a joint 26 capable of guiding the compressed fluid of the compressor 24 into the U-shaped tube 21 through the hole 22 and discharging the compressed fluid inside the U-shaped tube to the outside while controlling the speed. , Pistons 27, 28, internal packings 29, 30, 31, 32, internal magnet 33, load receiving base 34, external magnet 37, and linear guides 38, 3
9, 40, 41, counterweight 42, and compressor 24
And a controller 43 for controlling the pressure.

Since the load receiving base 34 has the balance function described in the first embodiment, it is stationary as long as no external force is applied. In this state, if the compressed fluid of the compressor 24 is introduced into the U-shaped pipe 21 through the hole 22, the load receiving base 34 is raised.
The ascent speed adjusts the exhaust speed at the joint 25. Further, when it is desired to lower the load receiving base 34, the compressed fluid of the compressor 24 may be put into the hole 23 and the exhaust speed of the joint 26 may be adjusted. It should be noted that the compressor does not become a dust source by completely casing it or installing it outdoors.

As described above, if it is about two-positioning control, it is not necessary to use an expensive linear motor, and it is possible to inexpensively realize a lifting device of a cleanness class of about 100. Further, as compared with the lifting device which simply uses the air cylinder or the hydraulic cylinder, the lifting device of the second embodiment has a balance function, so that it is possible to use a compressed fluid having a small pressure. Therefore, it is possible to use an inexpensive compressor.

[0018]

As described above, since the lifting device of the present invention generates very little dust from the balance mechanism, it can be used without a casing in a semiconductor factory or the like where cleanliness is required. There is an effect that there is. Moreover, since the balance mechanism and the guide mechanism are integrated, there is an effect that the mechanism can be simplified. Further, as shown in the second embodiment, since the balance mechanism, the guide mechanism and the moving mechanism can be integrated, there is an effect that the mechanism can be simplified and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a side view showing a first embodiment of the present invention.

FIG. 2 is a view showing a cross section taken along the line AA of FIG.

FIG. 3 is an enlarged view of portion B in FIG.

FIG. 4 is a side view showing a second embodiment of the present invention.

5 is a diagram showing a cross section taken along the line AA of FIG.

FIG. 6 is an enlarged view of portion C of FIG.

7A and 7B are views showing a conventional lifting device, in which FIG. 7A is a front view and FIG. 7B is a side view.

[Explanation of symbols]

 1 tube 2 fluid 3 piston 4,5 internal packing 6 internal magnet 7 load carrier 10 external magnet 11, 12, 13, 14 linear guide 15 piston 16 and 17 internal packing 18 counterweight 19 linear motor 20 controller 21 U-shaped tube 22, 23 holes 24 compressor 25,26 joint 27,28 piston 29,30,31,32 inner packing 33 inner magnet 34 load carrier 37 outer magnet 38,39,40,41 linear guide 42 counterweight 43 controller

Claims (1)

(57) [Claims] 1. A guide mechanism and a moving mechanism for moving up and down a load receiving tray on which a load is placed, a balance mechanism for reducing a driving force of the moving mechanism, and a control mechanism for controlling a moving position of the load receiving tray. U-tube in lifting device
An oval-shaped tube that combines two upper and lower parts
The fluid is sealed in the lower half of the inside, the pistons are placed on both open surfaces of the fluid, and the balance mechanism with the balance weight on one piston and the load receiving stand on the straight part of the oval pipe. And a guide mechanism for moving the load receiving base up and down by using the linear portion as a guide, magnets are embedded in the piston and the load receiving base, and a balance function is maintained through magnetic force.