JPS5977518A - Electromagnetic positioning and holding method - Google Patents

Abstract

PURPOSE:To eliminate the easy occurrence of step-out in case when an external force is put on, by cotrolling the supply of compressed air until the movement to the following positioning place is started after relative positioning of a fixed part and a moving part is ended. CONSTITUTION:Relative positioning between a platen 1 and a head part 2 is executed, and thereafter, when a compressed air supply quantity for forming an air bearing 3 is controlled and is reduced gradually, the platen 1 and the head part 2 reduce an air bearing gap, keeping mutually a relative position in the XY directions, and in the end, the gap is eliminated. This shows a state that permeance of a magnetic circuit formed between the platen 1 and the head part 2 becomes maximum, and its holding force also becomes maximum. In this way, when an assembly work is executed after controlling the compressed air supply quantity and making the holding force of the head part 2 maximum, even if large external force is put onto the head part and the subsequent part, the platen 1 and the head part 2 do not cause step-out, and the work can be executed exactly.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an electromagnetic positioning device employing a static air bearing, which controls the supply of compressed air forming the air bearing,
Furthermore, it relates to a method of controlling drive current.

Conventionally, the supply of compressed air to a static air bearing formed between a fixed part and a movable part in an electromagnetic positioning device has been kept constant from the start to the end of the device. However, in the conventional method of keeping the supply of compressed air constant from the start to the end of the electromagnetic positioning device, the movable part of the electromagnetic positioning device is When performing assembly work using various mechanisms fixed to the machine, there are many cases in which a large external force is applied. had the disadvantage that the electromagnetic positioning device would lose synchronization. Furthermore, as a result of the current being supplied to the positioning device during positioning, a local temperature rise occurs, which has a negative effect on the device.

The purpose of the present invention is to eliminate the above-mentioned drawbacks such as easy step-out when an external force is applied during electromagnetic positioning and the problem of heat generation due to energization during electromagnetic positioning. By controlling the supply of compressed air that forms the hydrostatic air bearing, we are able to obtain a strong holding force that prevents step-out even when large external forces are applied, and by controlling the drive current. The goal is to lower fever.

The present invention will be explained in detail in Example 1 below.

FIG. 1 shows an embodiment in which a 2I111I (plane) simultaneous electromagnetic positioning device is applied as an assembly device. 1 is a platen (fixed part) made of a magnetic material and has a grid-like protrusion on its surface, and a non-magnetic resin is filled between the protrusions to form a smooth surface. Reference numeral 2 denotes a head section (movable section) opposing the platen 1, and a group of electromagnetic elements for each of the X and Y axes (not shown) each having a protrusion corresponding to the protrusion of the platen 1 on its surface. ] is embedded in the platen 1 and head part 2 by applying a current corresponding to the positioning signal.
This makes it possible to perform positioning on a flat surface.

Further, the electromagnetic element embedded in the head portion 2 is composed of a combination of a permanent magnet and an electromagnet, and a convex portion corresponding to the convex portion of the platen 1 is formed on the surface of the core of the electromagnet. 3 is an air bearing, which connects the platen 1 and the head part 20.
Its role is to maintain an appropriate gap between the two. Reference numeral 4 denotes a frame fixedly attached to the head portion 2, and a motor 5 and a bearing case 6 are fixed with screws. When the motor 5 rotates in accordance with the rotation signal, the rotation is transmitted from the gear 7 on the motor shaft to the gear 8.
A shaft 9 integrated with the gear 8 rotates. 0 is a bearing when the shaft 9 rotates. A flange 11 is attached to the shaft 10, and a cylinder I2 is fixed thereto.

A piston 13 is located in the cylinder 12 and is moved up and down by compressed air and a spring 14. The piston 13 is provided with a claw 5 for chucking assembled parts and the like.

In the above configuration, after electromagnetic positioning is performed using the platen 1, head section 2, and air bearing 3, assembly work is performed by rotating the motor 5, moving the piston 13 up and down, and opening and closing the claws 15. After the assembly is completed, the head section 2 starts moving to the next positioning point in response to a command from the controller. While the head section 2 is positioned relative to the platen 1 and starts moving to the next point, assembly work etc. are carried out. Become. If the holding force between the head part 2 and the platen 10 is greater than the external force, the positioning will be maintained, but when the external force exceeds the holding force, a step-out occurs between the head part 2 and the platen 10, preventing normal assembly work. becomes impossible. After determining the relative position between the platen 1 and the head section 20, the amount of compressed air supplied forming the air bearing 3 is controlled and gradually reduced, so that the platen 1 and the head section 2 are While maintaining the relative position in the direction, the air bearing gap is gradually reduced until the gap disappears. This is platen 1 and head part 20.
This is the state in which the magnetic circuit formed between If the assembly work is carried out, even if a large external force is applied below the head part, the work can be carried out reliably without causing the platen 1 and the head part 2 to step out.Under normal conditions, the air gap of the air bearing 3 is il; !!, 10μ poison, and this level of vertical change will not have a negative effect on most assembly work.When the work is completed, increase the amount of compressed air supplied to obtain a normal air bearing clearance, and then proceed to the next step. All you have to do is start moving to the position g+towing point, and after the positioning is complete, control the compressed air supply amount and perform the work in the same manner as described above.

Furthermore, when the supply amount of compressed air 2 is reduced to zero and the air bearing warm temperature is reached, only the current supply to the drive device 1 to the electromagnetic elements in the head section 2 up to the controller rubber 0Nf7) 4 is turned off. , the platen 1 and the head part 20 are fixed to each other by the magnetic force of the permanent magnet contained in the electromagnetic element of the head part 2 while the electromagnetic position remains fixed. This makes it possible to perform work reliably, reduce power consumption in the ringer, and eliminate heat generation in the electromagnetic element. When starting to move to the next positioning point after completing work, turn on the power supply to the drive unit and then turn on the compressed air supply to the air bearing section.

FIG. 2 shows an embodiment of the present invention in a three-axis rotating electromagnetic positioning device. 1.2.3 are the platen, head section, and air bearing similar to those described in the embodiment of FIG. 1 above. I
A is a rotating platen made of a magnetic material and has radial protrusions on its surface, and between the protrusions, 1 is filled with non-magnetic resin to form a smooth surface. Tofu head part 2
is fixed. The two of them are a rotating head portion opposing the rotating platen IA, and an electromagnetic element (not shown) having a protrusion corresponding to the radial protrusion of the rotating platen IA.
is embedded and fixed to the rotating platen IA so that it can rotate and move up and down. 3A is rotating platen I
This is an air bearing that maintains an appropriate gap between A and the rotating head. 4A is a frame fixed to two rotating head parts; the following assembly is similar to that shown in the embodiment shown in Fig. M1. Work equipment for inspection etc. is fixed. c Omitted in this figure. ] FIG. 3 is a block diagram of a signal input path to the three-axis rotating electromagnetic positioning device in FIG. 2.

Positioning signals for each axis of X, Y, and θ (indicating the direction of rotation) are sent from the controller to the drive device. In the drive unit, the input signals X and Y are input from the controller. The signals on each axis of θ are converted into currents, amplified, and YIll are sent to the electromagnetic elements of each axis in the head section 2.

The axes are individually supplied to an electromagnetic element inside the rotating head 2 to determine the position of the three axes.

When performing various operations after positioning the X, Y, and θ axes, the external force applied to the positioning device is applied to the positioning device via the air bearing, as explained in the embodiment shown in If the holding force is exceeded, a step-out phenomenon will occur, making it impossible to continue the work. After positioning the three axes, the amount of compressed air supplied to each air bearing 3, 3A is controlled and gradually reduced, and the flow rate between the platen and the head (1 and 2, IA and 2A) is controlled and gradually reduced.
While maintaining the relative positions of the gaps in the XY and θ directions, the gaps become smaller and the holding force increases. In such a state, reliable work can be performed even under a larger external force. The air gap in the air bearings 3, 3A in a steady state is usually several tens of microns, and it is clear that such a change in vertical movement will not have an adverse effect on various operations. After the work is completed, a series of operations such as restoring the compressed air supply amount and starting the movement to the next positioning point (rotating table) is repeated. This is similar to the embodiment shown in FIG.

FIG. 4 is a block diagram of a signal input path to the three-axis simultaneous electromagnetic positioning device, similar to FIG. 3. X-axis and θ in the drive unit
By using a common shaft drive circuit (current conversion and amplification circuit) and providing a switching circuit, it is possible to switch the current supply to each head section of two people. Other details are the same as shown in FIG. Now, only the positioning signals for each of the X and Y axes are input from the controller to the drive device. Furthermore, current is supplied to the head section 2, and the relative positioning of the X and Y axes is performed by the platen 1 and air bearing 3. It will be done.

At this time, the compressed air supply to the air bearing 3A is controlled to zero, and the current supply to the two heads is also turned off. While maintaining this state, the compressed air supply amount of the air bearing 3 is controlled, and when it reaches zero, the controller remains ON and the X-axis (shared with the θ-axis) and Y-axis circuits of the drive device are set to 0F F l. By turning off the current supply to the head 2, as in the previous embodiment, the power consumption in the drive device can be reduced, positioning can be performed with high holding force, and heat generation in the electromagnetic element can be eliminated. Next, from the controller, only the θ-axis positioning signal is input to the drive device K, and furthermore, the switching circuit provided in the X-axis and θ-axis common circuit in the drive device is activated, and the rotation head is activated. Current is supplied to the two people.At this time, the Y drive circuit is O.
He even has the talent of FF.

Furthermore, is there an FEII between the rotating platen IA and the rotating head section? Air is supplied, and the air bearing 3A is formed to perform positioning in the rotational direction (θ axis). After determining the θ-axis position, control the amount of compressed air supplied to the air bearing 3A, and when it reaches zero, turn off the θ-axis (shared with the X-axis) drive circuit in the drive device while keeping the controller on. By turning off the current supply to the two rotating heads, the power consumption in the drive device can be reduced, positioning can be performed with high holding force, and heat generation in the electromagnetic element can be eliminated.
Same as for the axis. Thereafter, the series of operations may be repeated in the same manner as explained in FIG. In this way, there is no need for three drive circuits for each of the X, Y, and θ axes.
This means that control can be performed using individual drive circuits. Also, up until now we have explained the X-axis and θ-axis drive circuits in common, but it is clear that similar results can be obtained even if the Y-axis and θ-axis drive circuits are common. According to the invention, l is used to control the amount of compressed air supplied to the air bearing after electromagnetic positioning is completed.
This has the effect that the electromagnetic holding force between the head portion and the platen is large, and positioning that is resistant to external forces can be achieved.

Furthermore, by controlling the amount of compressed air supplied and then turning off the current supply to the head, it is possible to reduce power consumption in the drive device and eliminate heat generation. Furthermore, by applying the present invention to a three-axis rotating electromagnetic positioning device, the number of drive circuits required can be reduced from three to two.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view showing an embodiment of the invention in which a two-axis rotary electromagnetic positioning device is applied to assembly and coloring, and Fig. 2 is a side sectional view showing an embodiment of the invention in which a two-axis rotating electromagnetic positioning device is applied to assembly and coloring. FIGS. 3 and 4, which are partial cross-sectional views showing the embodiment, are block diagrams of input signal paths to the three-axis rotating electromagnetic positioning device in FIG. 2. j, platen (XYY axis) IAo rotating platen 2, head section (xyY axis) 2 people. Rotating head part 3, air bearing 3A, air bearing and above, Applicant Daini Seikosha Co., Ltd. Agent Attorney Mogami Fig. 2

Claims (1)

[Claims] α) In an electromagnetic positioning device that performs positioning while maintaining an appropriate gap between a fixed part and a movable part using a static pressure air bearing, after the relative positioning of the fixed part and the movable part is completed, An electromagnetic positioning method characterized in that the supply of compressed air is controlled until movement to the next positioning point is started. (2)lJf! An electromagnetic position holding method characterized in that in the range 2n1 term of the j\'FFJ search, after controlling the supply of compressed air, the supply of current to the electromagnetic positioning device is controlled.