JPH05212642A - Vacuum chuck - Google Patents

Abstract

PURPOSE:To provide a vacuum chuck which improves a speed of response to both suction and setting operations and is capable of controlling a stable attraction with high suction force. CONSTITUTION:Magnetostrictive displacement in a super-magnetostrictive material is made to act on an expansion lever 1 with a working point of force and an outputting point with a fulcrum as the center. This super- magnetostrictive materials coupling four rods 21, 22, 23, 24 in series by means of three levers 31, 32, 33, and it is also coupled so as to add quadruple magnetostrictions to a working point of the lever 1 in advance. The super- magnetostrictive material is controlled by an exciting coil 4, making the magnetostrictive displacement act on the expansion lever 1, and differential displacement with a resilient spring 5 is directly added to a diaphragm 7 of a suction pad 6, through which suction and detachment are controlled.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to vacuum chucks.

[0002]

2. Description of the Related Art A conventional vacuum chuck has a suction pad and a suction pump which are separated from each other and is connected to each other by a long pipe. The response speed is poor, and the suction pipe is clogged with dust or the like. There was a defect that the adsorption power was reduced.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object thereof is to obtain a stable vacuum chuck in which the suction response speed is increased and the suction force is not lowered.

[0004]

[Means for Solving the Problems] A micro-displacement is applied to a point of action to provide a magnifying lever that outputs a magnified displacement around a fulcrum, and an electrostrictive material or a magnetostrictive material that exerts a force on the point of action of the magnifying lever And a suction pad having a diaphragm that operates by the displacement output of the expansion lever.

[0005]

As described above, the present invention is provided with an enlargement lever for applying a small displacement to the action point and outputting a displacement enlarged about the fulcrum, and an electrostrictive material or a magnetostrictive member that exerts a force on the action point of the enlargement lever. Since the material is provided and the suction pad having the diaphragm that operates by the displacement output of the expansion lever is provided, the diaphragm of the operation lever and the suction pad are directly connected, and the high speed of the electrostrictive material or the magnetostrictive material is used. Since the force is applied to the expansion lever by the response and the displacement output is used for quick control, the response speed of adsorption / desorption is extremely high, and the chuck can be used as a high-performance chuck that maintains a high adsorption force.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment of the drawings. In FIG. 1, 1 is a point 1b of action of force centered on the fulcrum 1a.
And an enlarging lever having an output point 1c, the magnetostrictive displacement of the giant magnetostrictive material acts on the enlarging lever 1. The giant magnetostrictive material consists of four rods 21, 22, 23, 24 and three levers 31, 3
2, 33 are connected in series, and a combination of 4 times extension is added to the action point 1b of the lever 1. Reference numeral 4 is an exciting coil for driving the giant magnetostrictive material, 5 is a repulsion spring against an acting force provided on the expansion lever, 6 is a trumpet-shaped rubber suction pad, and the diaphragm 7 is provided in a movable state. It is provided so as to be operated by the displacement output applied to the output point 1c of the expansion lever 1.

The giant magnetostrictive materials 21 to 24 are made of, for example, Tb.
_{Using 0.3} Dy _0.7 Fe _1.95 , this thickness is 1 mm
Using 4 rods with φ and length of 50 mm, levers 31-33
When driven by a rod having a length of 50 × 4 = 200 mm, the magnetostriction is 200 × 2000 PPM =
It becomes 0.4 mm. This force acts on the expansion lever 1
If the magnification is doubled, the displacement output is 0.4 × 10 = 4.
mm, and when this displacement is applied to the diaphragm 7 and pulled up, the inside of the pad 6 becomes a vacuum and can be adsorbed.

It should be noted that the giant magnetostrictive material is operated by increasing the number of rods and combining a plurality of expanding levers so that the displacement output of one expanding lever is added to the action point of another expanding lever. The stroke can be further increased, a stroke of about 5 to 10 mm can be easily obtained, and the suction pad can be controlled. The suction force of the suction pad can be about 0.65 kg / cm ² per piece, and the suction force can be increased by providing a plurality of suction pads which are simultaneously operated by levers. The response frequency of the giant magnetostrictive material is 500 to 2
Approximately 000 Hz, adsorption / desorption response is msec
High-speed response can be achieved on the order, and response can be achieved at a speed 100 times faster than conventional.

FIG. 2 illustrates the adsorption / desorption characteristics of the adsorption pad in waveform display. The waveform a shows the ON / OFF characteristics when single-adsorption is performed, and the adsorption / desorption characteristics are almost rectangular wave characteristics. Control can be performed with high response. The waveform (b) is a characteristic when the diaphragm is vibrated by applying an oscillating magnetic field to the giant magnetostrictive material in the attracted state, and the peak of the adsorption force can be increased by vibrating. The waveform C is an example of the case where the diaphragm is vibrated from the beginning and is adsorbed while being vibrated, and the adsorbing force gradually increases. By controlling the magnetic field acting on the giant magnetostrictive material in this manner, various attraction forces can be controlled, and optimal control can be performed depending on the attraction target.

Further, since the impedance of the exciting coil acting on the magnetic field changes depending on the adsorbed state, that is, the magnetized state of the giant magnetostrictive material, the adsorbed state can be determined by detecting this impedance, and the detected signal is used. It is possible to proceed with automatic control and the like by NC control. In addition, it is possible to measure the weight of the object to be adsorbed by detecting the impedance, and automatic control using this can be performed extremely stably.

FIG. 3 shows another embodiment in which two expansion levers 1 are provided.
1 and 12 and the storage chambers of the giant magnetostrictive rods 21 and 22 are cut out from one member by one-stroke writing by wire cut electric discharge machining or the like. The levers 11 and 12 have their fulcrums left uncut. Point of action 1 of the expansion lever 11
Magnetostrictive displacement is added to 1a, and the output point 1 of this first lever 11
The enlarged output in 1b is the action point 12b of the second lever 12.
In addition to this, the diaphragm of the suction pad is activated by the displacement output at the same output point 12b enlarged by the second lever 12. The giant magnetostrictive material is composed of two rods 2.
The levers 1 and 22 are connected in series by the lever 3 and incorporated so that the magnetostriction of the rod 22 is applied to the action point 11a of the second lever 11.

By performing one-stroke writing by wire-cut electric discharge machining, the machining can be performed accurately and precisely, and the assembling structure can be easily configured.

[0013]

As described above, according to the present invention, the displacement of the giant magnetostrictive material or the electrostrictive material that expands and contracts is used as the driving source, so that the adsorption / desorption response is fast, the force is strong, and the attachment / detachment control is rapid. You can be sure. In order to control the diaphragm of the suction pad, the displacement of the magnetostrictive material or electrostrictive material is expanded and controlled by the expansion lever, so that the displacement output of a predetermined stroke can be easily obtained, and the displacement can be directly connected to the diaphragm of the suction pad. Since the control is performed, the attachment / detachment response speed can be increased and the suction control can be performed with a high suction force, so that a high-performance chuck can be easily obtained.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of adsorption characteristics of the present invention.

FIG. 3 is a diagram of another embodiment of the present invention.

[Explanation of symbols]

 1 Enlargement lever 21, 22, 23, 24 Giant magnetostrictive rod 31, 32, 33 Lever 4 Coil 5 Repulsion spring 6 Adsorption pad 7 Diaphragm

Claims (3)

[Claims] 1. An expansion lever for applying a small displacement to an operating point to output an expanded displacement centered on a fulcrum, and an electrostrictive material or a magnetostrictive material for applying a force to the operating point of the expanding lever, and A vacuum chuck comprising a suction pad having a diaphragm which is operated by a displacement output of the enlargement lever. 2. The vacuum chuck according to claim 1, further comprising an electrostrictive material or a magnetostrictive material in which a plurality of members that exert a force on the action point of the expansion lever are connected in series by levers. 3. The vacuum chuck according to claim 1, further comprising a plurality of suction pads having a diaphragm which operates by displacement output of the expansion lever.