JPH07263218A - Electromagnetic chuck - Google Patents

Abstract

PURPOSE:To realize positive holding and carriage by a structure wherein a main pole, having the forward end projecting by an adjustable length from the end face of a cylindrical case, is held by a yoke and sufficient attracting force is exhibited for a deformed yoke. CONSTITUTION:A cylindrical case 1 made of a magnetic material is fixed, at one end, with a planar yoke 2 made of a magnetic material. An exciting coil 4 wound around a bobbin 3 is bonded to the inside of the cylindrical case 1 through an adhesive 5. A main electrode 8 made of a heat treated steel member, for example, is held in the center of the yoke 2 while keeping the axis in parallel with the axis of the cylindrical case 1. The main electrode 8 can advance or retract in the axial direction of the cylindrical case 1 by tightening/ untightening an externally threaded screw 9 and an internally threaded screw 10. The main electrode 8 extends through the central part 11 of the coil 4 and projects from the end face 13 of the cylindrical case 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic chuck for lifting an object to be attracted by electromagnetic force.

[0002]

2. Description of the Related Art Conventionally, as an apparatus for hoisting and conveying an object to be attracted, which is made of a magnetic material, which is formed by press working or the like for automobile parts, various machine parts, etc., by electromagnetic force, for example, an electromagnetic chuck shown in FIG. It has been known.

This electromagnetic chuck has a yoke 3 in which a main pole 33 is projected from the end of a cylindrical case 31 made of a magnetic material.
2, a coil 34 for excitation is held inside the tubular case 31 in a state in which the main pole 33 is wound, and a tip end portion 35 of the main pole 33 serves as an end face portion 36 of the tubular case 31. It is fixed on the same plane. Then, the work W housed in the container 38 is brought into contact with a carrier device 37 such as a chain or a robot arm attached to the yoke 32, the coil 34 is energized to adsorb the work W, and the work W is lifted and carried.

[0004]

However, in the electromagnetic chuck having such a conventional structure, when the work W is not a simple flat shape but an irregular shape having irregularities, the end surface portion of the cylindrical case 31 is formed. 36 and the tip 3 of the main pole 33
Since 5 and 5 are located on the same plane, the adsorption of the work W is unstable and easily detached, and the adsorption probability is small. Moreover,
When the work W is tilted, the suction force is lowered and the work piece easily falls off. Further, even when the surface of the casting is rough, the suction force is lowered and it cannot be surely sucked and held.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an electromagnetic chuck that exerts a sufficient suction force on a deformed work and can be reliably held and conveyed.

[0006]

In order to achieve the above object, according to the present invention, an exciting coil is held inside a cylindrical case made of a magnetic material having a yoke attached to one end thereof, and a central portion of the coil is provided. A main pole having a tip portion projecting from the end surface portion of the tubular case and having a projecting length adjustable is held by a yoke.

The tip of the main pole may be formed in a flat surface. Further, by forming the tip portion of the main pole into a convex surface, the work can be effectively attracted.

[0008]

The protrusion length of the main pole of the electromagnetic chuck constructed as described above is adjusted so that the tip of the main pole is protruded from the end face of the cylindrical case by a required length, and the irregularly shaped work is housed in the container. When the lower part of the main pole is introduced into the coil and the coil is energized, an attractive force is generated between the main pole, the cylindrical case and the work due to the generated magnetic flux. As a result, a large number of workpieces are adsorbed and held around the protruding main pole at any angle between the workpiece and the end surface of the cylindrical case, and the workpieces are lifted and conveyed in a stable state.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a tubular case forming a magnetic circuit, which is made of a magnetic material such as carbon steel pipe, and one end of the tubular case 1 is a plate made of a similar magnetic material such as steel. The yoke 2 is fixed by crimping. Further, an exciting coil 4 wound around a synthetic resin bobbin 3 is fixedly held inside the cylindrical case 1 via an adhesive member 5, and one end of the coil 4 is An annular spacer 6 made of a non-magnetic material such as stainless steel is placed in contact with the coil 6 to protect the coil 4.
Is positioned and held in the cylindrical case 1 by a retaining ring 7.

At the center of the yoke 2, a main pole 8 made of heat-treated steel or the like is held with its axis parallel to the axis of the cylindrical case 1, and the main pole 8 has a screw formed on the outer periphery thereof. To form the yoke 2 on the yoke 2, it is screwed onto a screw 10 so as to be movable back and forth in the axial direction with respect to the cylindrical case 1. On the other side of the main pole 8, the central portion 1 of the coil 4 formed by the center hole of the bobbin 3 whose diameter is slightly larger than its outer diameter.
1, the flat tip portion 12 of the main pole 8 is located so as to project from the end surface portion 13 of the tubular case 1, and the main pole 8 is fixed by the nuts 14 and 15 screwed to the upper side. The cylindrical case 1 is positioned and fixed.

Reference numeral 16 is a lead wire of the coil 4, which is connected to a control panel (not shown) through a take-out hole 17 provided through the yoke 2, and a mounting portion 18 is formed at one end of the main pole 8. A transfer device 19 such as a chain or a robot arm shown in FIG. 3 can be connected, and a reference numeral 20 indicates a container for a work W having an irregular shape.

In the electromagnetic chuck constructed as described above, when the nuts 14 and 15 are loosened and the main pole 8 is rotated with respect to the yoke 2, the main pole 8 moves back and forth due to the screwing of the screw 9 and the female screw 10. The tip portion 12 is adjusted so as to be a predetermined protruding position from the end surface portion 13 of the cylindrical case 1 corresponding to the work W, and the nuts 14 and 15 are tightened to fix the main pole 8. Subsequently, as shown in FIG. 3, the transfer device 19 is connected to the mounting portion 18, and the cylindrical case 1 is positioned on the container 20 in which the work W is stored. Then, the cylindrical case 1 is transferred by the transfer device 19.
When the coil 4 is made to descend and the leading end 12 of the main pole 8 is inserted into the work W and an exciting current is supplied to the coil 4 through the lead wire 16, a magnetic circuit is formed by the cylindrical case 1, the yoke 2 and the main pole 8. It Due to the magnetic flux generated by this, an attractive force is generated between the cylindrical case 1, the main pole 8 and the work W,
The deformed work W has a cylindrical case 1 with the main pole 8 as the center, and an end face portion 1
3 and 3 are adsorbed and held from all angles.

Thereafter, the cylindrical case 1 is moved by the transfer device 19.
Is raised, the adsorbed and held work W is conveyed to the next step, and when the exciting current to the coil 4 is cut off at a predetermined place, the adsorbing force disappears and the work W is released.

When the work W is changed, the nuts 14 and 15 are loosened in the same manner as described above in accordance with the shape of the work W.
Rotate forward and backward to adjust the protruding length.

In the embodiment shown in FIG. 4, the tip of the main pole 8 is formed into a convex surface having an arcuate cross section, and it is effective for adsorbing an irregularly shaped work W having large irregularities.

Further, in FIG. 5, when the tip end portion 22 of the main pole 8 is formed into a convex surface of a truncated cone shape, FIG.
In the embodiment in the case of being formed into a conical shape, an effective suction holding state can be obtained by using the work W in accordance with the deformed state, the dimension and the like.

In the embodiment, the yoke 2 is the cylindrical case 1.
Although the end portions are caulked, the both may be integrated.

[0019]

As described above, according to the electromagnetic chuck of the present invention, since the tip of the main pole projects from the end surface of the cylindrical case and the projecting length can be adjusted, it is formed on the lower side of the electromagnetic chuck. The suction zone is widened, and irregularly shaped workpieces with large irregularities can be sucked from all angles, making it possible to suction and convey a large number of workpieces at a time. Even though it is co-adsorbed with the cylindrical case, it is hard to fall off,
Even a product with rough skin such as a cast product can exert a sufficient adsorption force.

Further, by adjusting the protrusion length of the main pole, it is possible to select the contact position of the workpiece by shortening the protrusion length of the irregularly shaped work having small irregularities and conversely making it large. Therefore, it is possible to always maintain a good suction state in response to various works.

Furthermore, by forming the tip of the main pole into a convex surface, the closeness of the main pole to the irregularly shaped work is increased,
The suction effect is improved, and more workpieces can be suction-lifted and transported.

[Brief description of drawings]

FIG. 1 is a front sectional view of an embodiment of the present invention.

FIG. 2 is a plan view of the same.

FIG. 3 is a partially cutaway front view in a state where a work is attracted.

FIG. 4 is a partially cutaway front view showing another embodiment of the tip of the main pole.

FIG. 5 is a partial front view showing another embodiment of the present invention.

FIG. 6 is a partial front view showing another embodiment of the same.

FIG. 7 is a partially cutaway front view showing a suction state of a work when the tip of the main pole is a convex surface having an arcuate cross section.

FIG. 8 is a front sectional view showing an example of a conventional electromagnetic chuck.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylindrical case 2 Yoke 4 Coil 8 Main pole 11 Central part 12,21,22,23 Tip part 13 End face part

Claims (3)

[Claims] 1. A coil for excitation is held inside a cylindrical case made of a magnetic material with a yoke attached to one end, and a tip portion projects from an end face portion of the cylindrical case through a central portion of the coil. At the same time, an electromagnetic chuck in which a main pole whose projecting length is adjustable is held by the yoke. 2. The electromagnetic chuck according to claim 1, wherein a tip portion of the main pole is formed into a flat surface. 3. The electromagnetic chuck according to claim 1, wherein a tip end portion of the main pole is formed into a convex surface.