JPH01236193A - Lifter magnet - Google Patents

Abstract

PURPOSE:To make it possible to prevent an accidental separation of a work and attract even a stepped work surface to be attracted by performing the attracting operation by means of magnetic force of a permanent magnet, and demagnetizing a magnetic flux extending from the per manent magnet to the work by energizing a coil. CONSTITUTION:When a magnetic flux from a permanent magnet passing throough a main iron core 2 is demagnetized by energizing a coil 10, the magnetic flux does not reach a movable yoke 3, and the movable yoke 3 can freely advance and retract. Under the condition, the movable yoke 3 is abutted on a work W. When the coil 10 is deenergized, the magnetic flux from the permanent magnet 1 reaches the work W through the movable yoke 3, and the work W is attracted to the movable yoke. At this time. the movable yoke 3 is attracted to the main iron core 2 not to be advanced and retracted. Next, when the work W is to be released, the coil 10 is energized by the same way as stated above. The magnetic flux thus does not reach the work W from the movable yoke 3, and the work W is released.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a lifter magnet for transporting a workpiece by attracting it by magnetic force, and more specifically, it relates to a lifter magnet for transporting a workpiece by attracting it by magnetic force. The present invention relates to a lifter magnet that can prevent workpieces from falling off (falling off due to power outages in the case of electromagnets).

[Conventional technology]

A column-shaped yoke is attached to one magnetic pole of the permanent magnet, and a cup-shaped yoke is attached to the other pole, and magnetic flux is applied from both yokes to the workpiece to attract the workpiece. When releasing the workpiece, there is a method in which the workpiece is released by energizing a coil attached to the columnar yoke to eliminate the bundle applied to the workpiece (for example, Japanese Patent Publication No. 55-30144) of uniform structure).

[Problem to be solved by the invention]

In this conventional lifter magnet, both yokes are integrated with each other, so workpieces with a flat surface to be attracted can be stably attracted, but workpieces with steps on the surface to be attracted may not be fully attracted. There was a problem.

The present invention has been made in view of the above points, and its purpose is to stably adsorb not only workpieces with a flat surface to be attracted, but also workpieces with steps on the surface to be attracted. An object of the present invention is to provide a lifter magnet.

[Means to solve problems]

In order to achieve the above object, the present invention takes the measures as described in the claims above, and its effects are as follows.

[Effect]

When the magnetic flux from the permanent magnet passing through the main core is canceled by energizing the coil, the magnetic flux no longer reaches the movable yoke, and the movable yoke can move forward and backward. In this state, move the movable yoke to the workpiece. When the power to the coil is cut off, the magnetic flux from the permanent magnet reaches the workpiece through the movable yoke, and the workpiece is attracted.

Also, at this time, the movable yoke is attracted to the main iron core and cannot move forward or backward. Next, when releasing the work, the coil is energized in the same way as above. As a result, the magnetic flux from the movable yoke no longer reaches the workpiece, and the workpiece is released.

(Example〕 The drawings showing the embodiments of the present application will be described below.

In FIGS. 1 to 3, 1 is a permanent magnet, and Ia and lb indicate its magnetic poles. The permanent magnet 1 may be a ferrite magnet, a rare earth magnet, or the like. Reference numeral 2.2 denotes a main core, each made of a soft magnetic material, and integrated with a permanent magnet with one end of each core aligned with the magnetic poles la and lb. 3.3 is a movable yoke made of a soft magnetic material, which independently advances and retreats toward the work W side with respect to each other end (support surface 7) of each of the main iron cores (up and down in Fig. 1.3). Direction) can be attached. To explain the attached structure, 4 is a guide piece fixed to the main core 2, 5 is a stopper piece provided at the tip of the guide piece,
Reference numeral 6 denotes a long hole formed in the movable yoke 3, in which the guide piece 4 is positioned. With this structure, the movable yoke 3 can freely move forward and backward in the above direction along the yoke supporting surface 7 of the main iron core 2. Note that 3a indicates the suction surface at the tip of the movable yoke.

Next, 8 indicates a release member attached to the main core 2. In this, 10 is a coil disposed on the outer peripheral side of the main iron core 2;
is an auxiliary yoke that guides the magnetic flux generated by the coil 10 to make it easier to pass through the main iron core 2. In the auxiliary yoke, 12 is a first element formed integrally with the main iron core 2 in the shape of a flange. Reference numeral 13 denotes a second element, the inner peripheral edge 13a of which is connected to the outer periphery of the main iron core 2, and the other end, that is, the #i edge 13b of the cylindrical portion, is connected to the first element 12 across the magnetic gear.
It is to face each other.

Next, 15 is a detour member, which is a magnetic circuit for detouring the magnetic flux of the permanent magnet 1 when the coil is excited.

In this structure, a magnetic conduction member 16 is a yoke for guiding magnetic flux, and is formed integrally with the main iron core 2 and the first element 12 of the auxiliary yoke 11 in the shape of a flange. A bypass yoke 17 is made of a soft magnetic material and faces the magnetically conductive members 16 on both sides with magnetic gears 18 in between. This gap 18 may be filled with a non-magnetic material, or the gaps 18 on both sides may be combined into one. A holding member 19 is used to mechanically hold the bypass yoke 17.

Next, 20 is a connecting member for connecting the lifter magnet to a well-known conveyance means not shown.

Next, in the excitation circuit for the coil 10, 21 is a DC power supply, which is connected to the coil 10 so as to generate a magnetic flux in a direction opposite to the direction of the magnetic flux of the permanent magnet 1. The output of the DC power supply 21 may be a complete DC or a pulsating voltage such as a full-wave rectified AC. The connection is shown as two coils connected in series, but
They may also be connected in parallel. Reference numeral 22 indicates a switch provided in the above connection circuit.

Next, the magnetic operation of the lifter magnet having the above structure will be explained. When the coil 10 is not energized as shown in FIG. 1, the magnetic flux φI of the permanent magnet 1 passes through the main iron core 2 and reaches the movable yoke 3 as shown in the same figure. Therefore, along the suction surface 3a (if there is a workpiece W made of n-type material,
The magnetic flux φ1 is generated by the permanent magnet 1 - one main iron core 2 - one movable yoke 3 - the work W - the other movable yoke 3 - the other main iron core 2 - the permanent magnet l, and the work W is attracted. held in state.

On the other hand, as shown in Fig. 3, the coil 10 has 3! When the current is applied, a magnetic flux φ2 is generated by the coil 10 as shown in the figure, and this magnetic flux φ
2, the magnetic flux φl in the path is canceled out and disappears. That is, the magnetic flux flowing from the main core 2 to the movable yoke 3 disappears, and at the same time, the magnetic flux reaching the workpiece W also disappears.Therefore, the workpiece W that was in the attracted state is released.

In the above case, the magnetic flux of the permanent magnet 1 passes in the order of permanent magnet l - one magnetically conductive member 16 - bypass yoke 17 - the other magnetically conductive member 16 - permanent magnet 1, as shown by φ3. . That is, magnetic flux in the opposite direction to the magnetic flux of the permanent magnet 1 does not pass through the permanent magnet 1, and deterioration of its magnetic properties is prevented.

Next, the conveyance of the workpiece W by the lifter magnet will be explained. First, as shown in FIG. 3, the lifter magnet is brought close to a workpiece W (such as a pressed product or an iron block) while the coil 10 is energized. In this case, the movable yoke 3 is not attracted to the main core 2 and can freely move forward and backward in the direction of the arrow. Therefore, even if the workpiece W has a step as shown in the figure, each movable yoke 3 moves in and out according to the step, and the suction surface 3 of each movable yoke 3
a is in a state in which all of them are along the surface of the workpiece W.

Next, as shown in Figure 1 (when the power to the coil 10 is cut off, the permanent 6
The movable yokes 3 are attracted to the supporting surface 7 of the main iron core 2 by the 6n bundles φ1 of n stones 1, and the movement of each movable yoke 3 is fixed.
Further, the workpiece W is attracted to the attraction surface 3a by the magnetic flux φ1. In this state, move the lifter magnet and
is transported to the destination.

Next, at the destination, the coil 10 is energized again as shown in FIG. Then, the above fi bundle φ1 also disappears, and the workpiece W is released.

In this case of release, there are main iron cores 2 on both sides of the permanent magnet 1,
Since a coil 1o is attached to each of them, the magnetic flux φl is completely eliminated for each of both movable yokes 3.

Therefore, the release of the workpiece W is reliably performed in any movable yoke 3.

Next, the magnetic gap 18 will be explained.

Although the gap 18 is determined empirically,
When the permanent magnet 1 and the gap 18 have the same magnetic path cross-sectional area (cross section perpendicular to the magnetic flux), the length of the gap 18 is set to about 0.1 to 0.3 of the length of the permanent magnet 1. .

There is a close relationship between the size of the gear knob 18 and the ampere turns of the release coil 10, which is the value obtained by multiplying the ratio of the length of the gap 18 from 0.1 to 0.3 by the magnetomotive force of the permanent magnet. Therefore, the smaller the gap 18, the smaller the ampere turns of the release coil 10.

Next, the movable yoke 3 always slides against the supporting surface 7 of the main core 2 (generally in the vertical direction, but sometimes in the horizontal direction)
Therefore, in order to protect both sliding surfaces, it is desirable to perform a hardening treatment on those surfaces, for example hardening heat treatment on hard chrome plating or electroless nickel phosphorus plating.

Next, a description will be given of FIGS. 4 to 7 showing different embodiments of the present application. These figures show an example in which the movable yokes on both sides of the permanent magnet are each made up of a plurality of movable yoke pieces, and each movable yoke is further provided with an auxiliary core for stabilizing it.

In the figure, 23, 23, . . . are movable yoke pieces, which can move forward and backward toward the workpiece W, respectively. 2
3a and 23b are stoppers provided on each movable yoke element. 24 is a holding frame for the movable yoke piece, and the main iron core 2e
The movable yoke element piece 23 is mounted on top by a top mounting member 25 with an interval that allows the movable yoke piece 23 to freely move forward and backward smoothly. 26 is a spacer for maintaining the distance.

Note that both the holding frame 24 and the spacer 26 are made of non-magnetic material. Next, reference numeral 27 denotes an auxiliary iron core, which is fixed to the holding frame 24 with an upper screw member 25''. 28°28
indicates a support surface of the auxiliary core 27. Both sides 28
．． The spacing between 28 is the support surface 1e of each main core 2e.

It is equal to the spacing between 7e and 7e. Reference numeral 29 denotes a brake member provided on the support surface, which is made of a non-slip material such as rubber, plastic, asbestos, etc. that can provide a large frictional force with the movable yoke piece 23, and is fixed to the auxiliary iron core 27. A brake member 30 is provided on the support surface 7e and has the same structure as the brake member 29 described above. Reference numeral 31 shown in FIG. 7 is a fixing screw member for integrating the two main cores 2e and the permanent magnet 1e.

The lifter magnet as described above is attached to the arm of a transport robot, for example.

In the case of the above structure, when the workpiece W is attracted, the permanent magnet 1e is attached to the workpiece W as shown in FIG.
The side 3 facing each of the movable yokes 3e, 3e on both sides of the
2.33 Of course, if there is a difference in level between each side,
．． 33, even if there are steps or unevenness in the portions 33a and 33b facing each movable yoke piece 23 as shown in FIG. The suction surfaces 23C of the movable yoke pieces 23 are also in direct contact with the surface of the workpiece W, respectively. Therefore, even such a workpiece W can be stably attracted.

When adsorbing the workpiece W as described above, the permanent magnet 1e
The magnetic flux is divided into two, one is from the movable yoke 3e to the work W
On the other hand, the two movable fields 3e are bridged by the auxiliary iron core 27, and the magnetic flux φ4 passes through the auxiliary iron core 27. The magnetic flux φ1e acts as a force that attracts the movable yoke element 23 and the work W on the attraction surface 23c of each movable yoke element 23. On the other hand, the magnetic flux φ4 acts as a force that attracts the movable yoke element piece 23 and the auxiliary iron core 27 on the support surface 28. Further, the combined magnetic flux of φ1e and φ4 passes through the support surface 7e, and the movable yoke piece 23 and the main iron core 2e are attracted to each other. The adhesion forces on both of these supporting surfaces 7e and 28 result in a large frictional force that actually prevents the movable yoke piece 23 from shifting. As a result, even a heavy workpiece W can be stably attached to the main iron core 2e without the movable yoke piece 23 slipping down.

Note that the presence of the brake members 29, 30 further increases the frictional force.

Next, the magnetic specifications of the above-mentioned lifter magnet will be explained. The width of the permanent magnet 1e (the cross-sectional area in the direction orthogonal to the direction of magnetic flux) is set to be approximately the same as or larger than the width of the main core 2e so that sufficient magnetic flux can be supplied. The following relationship is established between the width S of the main core 2e, the width H of the auxiliary core 27, the thickness T of the workpiece W, and the thickness D of the movable yoke.

S>K・(T+H), D>H, H>T Here, K varies depending on the material of the permanent magnet 1e, but is set to be 5 to 8 for a ferrite magnet and 2 to 3 for a rare earth magnet. Of course, these relationships should be considered including the reduction in area due to the brake members 29, 30. By providing such a dimensional relationship, the permanent magnet 1e can supply sufficient magnetic flux to the auxiliary core 27 and the workpiece W, and can bring each of them into a magnetically saturated state or a state close to it.

It should be noted that parts that are considered to have the same or equivalent configuration as those in the previous figure in terms of function are given the same reference numerals as those in the previous figure with an alpha character e, and redundant explanations are omitted.

Next, the movable yoke piece 2 in the lifter magnet
3. Since the mutually opposing surfaces slide against each other, the sliding surfaces may be hardened in the same way as the splicing surfaces, etc., or the movable yoke may be diagonally 5 ~1
It is preferable to provide a slope of 0° to reduce the mutual contact area.

〔Effect of the invention〕

As described above, in the present invention, the workpiece W can be attracted by the magnetic flux from the permanent magnet 1, while the magnetic flux extending from the permanent magnet 1 to the workpiece W is extinguished by energizing the coil 10, so that the workpiece W can be attracted to the workpiece W by the magnetic flux from the permanent magnet 1. When picking up a workpiece W with a step on the surface, the movable yokes 3 on both sides, which can move forward and backward, independently advance toward the workpiece W and come into contact with it, permanently contacting the workpiece W. Both poles 1a of the magnet 1,
The magnetic flux from lb can be directly applied to the movable yoke 3 (without separating the air gap), and even the work W as described above can be reliably attracted.

[Brief explanation of the drawing]

The drawings show an embodiment of the present application, and FIG. 1 is a longitudinal cross-sectional view of the beam magnet in a workpiece adsorption state, FIG. 2 is a side view, and FIG.
Fig. 4 is a longitudinal sectional view showing a different embodiment in a workpiece suction state, Fig. 5 is a right side view of the same, Fig. 6 is a longitudinal sectional view showing the example in Fig. 4 in a state when the workpiece is released, and Fig. 7. is a sectional view taken along the ■-■ line. l...Permanent magnet, 2...Main core, 3...Movable yoke, 10...Coil, W...Work.

Claims (1)

[Claims] 1. One end of each of two main cores for passing magnetic flux is individually attached to one and the other magnetic pole of the permanent magnet, and each other end of each of the main cores is provided with one end of each of the two main cores for passing magnetic flux. , a movable yoke is attached to each of the movable yokes so as to move forward and backward toward the workpiece independently, and each of the main iron cores is provided with a magnetic flux that is applied to the workpiece by canceling the magnetic flux from the permanent magnet passing through the main iron core. Lifter magnets each equipped with a coil to eliminate magnetic flux. 2. One end of each of two main cores for passing magnetic flux is individually attached to one and the other magnetic pole of the permanent magnet, and a movable yoke is attached to each other end of each of the main cores, respectively. Each of the above-mentioned main iron cores is attached to each of them independently so as to be able to move forward and backward toward the workpiece, and each of the above-mentioned main iron cores has a magnetic flux that is applied to the workpiece from the above-mentioned movable yoke by canceling out the magnetic flux from the permanent magnet passing through the main iron core. A lifter magnet, wherein a coil is attached to each of the permanent magnets, and a detour member is attached to the permanent magnet for detouring magnetic flux from the permanent magnet when the coil is activated. 3. One end of each of two main iron cores for passing magnetic flux is individually attached to one and the other magnetic poles of the permanent magnet, and a movable yoke is attached to each other end of each of the main iron cores, respectively. Each of the above-mentioned main iron cores is attached to each of them independently so as to be able to move forward and backward toward the workpiece, and each of the above-mentioned main iron cores has a magnetic flux that is applied to the workpiece from the above-mentioned movable yoke by canceling out the magnetic flux from the permanent magnet passing through the main iron core. A lifter magnet, each of which is provided with a coil, each of which is provided with an auxiliary yoke for guiding magnetic flux from the coil when the coil is activated. 4. One end of each of two main cores for passing magnetic flux is individually attached to one and the other magnetic pole of the permanent magnet, and a plurality of movable yokes are attached to each other end of each of the main cores. Each element is independently attached to the work so that it can move forward and backward, and furthermore, by canceling the magnetic flux from the permanent magnet passing through the main iron core, the magnetic flux from the movable yoke element is applied to the work. Lifter magnets each equipped with a coil to eliminate magnetic flux. 5. One end of each of two main iron cores for passing magnetic flux is individually attached to one and the other magnetic poles of the permanent magnet, and a movable yoke is attached to each other end of each of the main iron cores, respectively. Each of the above-mentioned main iron cores is attached to each of them independently so as to be able to move forward and backward toward the workpiece, and each of the above-mentioned main iron cores has a magnetic flux that is applied to the workpiece from the above-mentioned movable yoke by canceling out the magnetic flux from the permanent magnet passing through the main iron core. A lifter magnet in which a coil is attached to each of the two movable yokes, and an auxiliary iron core is interposed between the two movable yokes, which bridges a part of the magnetic flux passing through the movable yokes to attract the movable yokes to itself.