JPH047913Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is suitable for use in manipulators, more specifically, conveyance systems, etc. Among manipulators that fix a workpiece by magnetic force, permanent magnets are used. This invention relates to a manipulator that can fix a workpiece using a permanent magnet and control the magnetic force of the permanent magnet using an electromagnetic coil.

[Prior Art] Conventionally, various types of manipulators for conveyance systems have been provided depending on their uses.

Among these manipulators, there was also a manipulator that magnetically attracted the workpiece, especially when the workpiece was a magnetic material.

However, manipulators that magnetically attract workpieces have conventionally used electromagnetic coils to attract and release the workpieces, and have used electromagnetic coils to attract the workpieces and transfer the workpieces in the excited state. The workpiece was released by degaussing.

[Problems to be solved by the invention] However, in conventional manipulators that use electromagnetic coils, the electromagnetic coil is always energized from the time when the workpiece is attracted until it is released, that is, during transportation, so the electromagnetic coil is The coil was used continuously, leading to an increase in the size of the electromagnetic coil and the amount of electricity used.

Furthermore, if the power is cut off due to a power outage or shot during transportation, the electromagnetic coil will be demagnetized, causing the workpiece to fall at that moment, which is extremely dangerous.

Furthermore, there were cases in which the workpiece became energized while being transported and did not fall even after demagnetizing the electromagnetic coil, and the workpiece remained energized even after being dropped into a predetermined position, so it could not be used unless it was in a de-energized state. It could not be used to transport workpieces that cannot be transported.

Conventionally, permanent magnets and electromagnetic solenoids have been combined, such as the invention described in Japanese Patent Application Laid-open No. 58-186910 and the invention described in Utility Model Publication No. 47-35489. There was also a model that held the workpiece in place and used an electromagnetic solenoid to generate a reverse magnetic field when the workpiece was released.

By forming it in this way, the electromagnetic coil is not constantly energized during transportation, and during transportation,
Even if the power supply is cut off due to a power outage or shot, the workpiece will not fall, and the workpiece can be demagnetized after being released at a predetermined position.

On the other hand, for this type of manipulator,
For example, as in the invention described in Japanese Unexamined Patent Publication No. 58-181592, there has also been provided an apparatus that detects approach to a workpiece based on a change in the magnetic flux density of an attached induction coil.

However, even with this invention, an induction coil for detecting the approach of a workpiece is required as a single unit, and an increase in the overall size is unavoidable.

Therefore, the present invention combines an electromagnetic coil and a permanent magnet, fixes the workpiece by the magnetic force of the permanent magnet, and releases the workpiece by canceling the magnetic field of the permanent magnet by generating a magnetic field in the opposite direction of the electromagnetic coil. In this way, the magnetic force of the permanent magnet can be controlled by the magnetic force of the electromagnetic coil, thereby shortening the energization time to the electromagnetic solenoid, making it possible to use a small electromagnetic coil, and even if the energization is cut off during transportation. In order to improve safety by preventing the workpiece from falling off, and furthermore, by using the electromagnetic coil that performs the control as an inductance sensor when demagnetizing the electromagnetic coil when the workpiece is not attracted, the permanent magnet An object of the present invention is to provide a manipulator that can detect approaching a workpiece or falling of a workpiece during transportation by detecting a dynamic change in magnetic force as a change in inductance.

[Means for solving the problems] In order to solve the above-mentioned problems, the present invention has the following features:
A permanent magnet and an electromagnetic coil in which the direction of the magnetic field at the pole part matches the magnetic field direction at the pole part of the permanent magnet regardless of whether it is forward or backward are fixed with a cover, and when the workpiece is released, the electromagnetic coil is fixed with a cover. A control device is attached to control the magnetic force of the electromagnetic coil so that a magnetic field opposite to that of the magnet is generated, so that the overall magnetic force can be controlled, and the electromagnetic coil is used as a release coil when releasing the workpiece. , is characterized in that it is used as an inductance sensor that detects changes in the magnetic field of a permanent magnet as it approaches the workpiece.

[Operation] The manipulator according to the present invention is positioned above a workpiece by an X-Y table (not shown), and then lowered toward the workpiece.

At this time, the electromagnetic coil is demagnetized and only the magnetic force of the permanent magnet acts.

Therefore, when this electromagnetic coil is used as an inductance sensor, dynamic changes in the magnetic force of the permanent magnet due to approach to the work can be detected as inductance, so approach to the work can be detected.

After approaching the workpiece in this way, the workpiece is attracted by the magnetic force of the permanent magnet, and after being raised and moved, it is lowered at a predetermined position to release the workpiece.

When the workpiece is released, the electromagnetic coil is excited so that the magnetic field is opposite to that of the permanent magnet, and the magnetic field of the entire manipulator is controlled so that the magnetic field is opposite to that during conveyance.

By creating such a magnetic field, the workpiece, which has already been magnetized in a certain direction, instantly separates from the manipulator, allowing the workpiece to be released.
This reverse magnetic field can also demagnetize a workpiece that has been magnetized during transportation.

Furthermore, the magnetic force of a permanent magnet is always a constant value, but in this invention, an electromagnetic coil is combined with this permanent magnet, so the magnetic force of the permanent magnet can be controlled by the magnetic force of the electromagnetic coil. become.

Therefore, the magnetic force of the electromagnetic coil with respect to the permanent magnet is
In the case of 2.5 times, the magnetic force of the entire manipulator can be controlled in the range of +350% to -150%.

[Example] An example of the present invention will be described below with reference to an illustrated example.

1 and 2 are sectional views showing different embodiments of the manipulator according to the present invention.

In the figure, the manipulator according to the present invention includes a permanent magnet 20 inside a soft iron yoke 10, and an electromagnetic field whose direction is the same as the magnetic field direction at the pole part of the permanent magnet 20 regardless of whether it is forward or reverse. It is formed by incorporating a coil 30 therein.

The permanent magnet 20 is formed in a donut shape and is easily broken, so it is fixed at a position where it is not directly exposed to the outside. Further, in order to make the permanent magnet 20 strong and small in size, it is desirable to use a rare earth material.

The electromagnetic coil 30 is wound around a coil hobbin 11 to form a cylindrical shape, and a mold 12 is provided at the bottom of the coil hobbin 11. Also, since the permanent magnet 20 is located inside the cylinder of the coil hobbin 11, the permanent magnet 20 and the electromagnetic coil 30
The direction of the magnetic field will match that of the For example, in FIG. 1, if the permanent magnet 20
When the upper surface is the north pole, the upper surface of the electromagnetic coil 30 becomes the north pole or the south pole, and in either case, the direction of the magnetic field will match, regardless of whether it is positive or reverse. Furthermore, in the above example, if the upper surface of the electromagnetic coil 30 is excited so that it becomes an S pole having the same magnetic flux density as the permanent magnet 20, the magnetic force will be canceled by the permanent magnet 20 and the electromagnetic coil 30. , the result is the same as the state where there is no magnetic force, and when the permanent magnet 20 is excited so that the S pole has a larger magnetic flux density than the magnetic flux density of the permanent magnet 20, the result is a reverse magnetic field as a whole. On the other hand, if the upper surface is excited so that it becomes a north pole having the same magnetic flux density as the permanent magnet 20, the magnetic force as a whole will be twice as large.

Note that there is an X-Y line (not shown) on the top of the yoke 10.
A fixing member 13 is provided for fixing to the table. Further, a cord 14 for connecting to a control device 40 extends from the electromagnetic coil 30.

Furthermore, since this electromagnetic coil 30 can be used as an inductance sensor during demagnetization, when the magnetic field of the permanent magnet 20 changes, the change in the magnetic field can be detected as dynamic mutual inductance. Therefore, it is possible to detect approaching the work 50 and falling of the work 50 due to external force during transportation.

Further, the electromagnetic coil 30 can be controlled by a sweep current. This sweep current is a current from a so-called slow-up-down circuit, and when supplying current to the electromagnetic coil 30 or stopping the current being supplied, etc.
This allows the current to change in a curved manner. Although a detailed explanation will be omitted, it can also be used as a sweep voltage instead of a sweep current.

Next, we will explain the actual use and operation of the manipulator according to the present invention, taking as an example a case where the manipulator according to the present invention is fixed to an X-Y table (not shown) and a workpiece 50 is moved from point A to point B. I will explain about it.

First, the electromagnetic coil 30 is installed so that it can obtain a magnetic force about 2.5 times that of the permanent magnet 20.
and a control device 40.

Next, the manipulator is lowered toward the workpiece 50 from above point A.

At this time, since the electromagnetic coil 30 is demagnetized, a magnetic field is generated by the permanent magnet 20.

When this manipulator approaches the workpiece 50, the magnetic flux density of the magnetic field of the permanent magnet 20 changes, and the dynamic change in the magnetic flux density is detected as a change in the inductance of the electromagnetic coil 30 as an inductance sensor.

Therefore, the manipulator is lowered at a fairly high speed until it approaches the workpiece 50.
By lowering the descending speed after detecting the approach to the workpiece 50 as a change in the inductance of the electromagnetic coil 30, the time for approaching the workpiece 50 can be shortened and the impact force at the time of contact with the workpiece 50 can be alleviated.

After the electromagnetic coil 30 serving as an inductance sensor detects the change in the magnetic flux density of the permanent magnet 20 due to approaching the workpiece 50 in this way, the manipulator is brought into contact with the workpiece 50 and adsorbed at the reduced descending speed. You can also do it. Strictly speaking, in this case, the workpiece 50 is attracted to the yoke 10 of the manipulator before the manipulator comes into contact with the workpiece 50.

In addition, in order to avoid the impact caused by the adsorption of the workpiece 50 to this manipulator, the workpiece 50 must be connected to the electromagnetic coil 30 as an inductance sensor.
After detecting the approach, the electromagnetic coil 30 is excited so that the magnetic field is opposite to that of the permanent magnet 20, the manipulator as a whole is brought into contact with the workpiece 50 with no magnetic field, and after contacting the workpiece 50, the electromagnetic coil 30 is demagnetized. By adsorbing the magnetic material, it is possible to prevent impact caused by magnetic adsorption.

If a sweep current is used to excite or demagnetize the electromagnetic coil 30 in this manner, a high current is not required, and therefore noise can be prevented and the demagnetization effect of the permanent magnet 20 can be reduced.

After the work 50 has been suctioned in this way, the moving device is operated to raise the work 50 and then move it to point B according to the XY table.

Further, while the workpiece 50 is being transported, the electromagnetic coil 30 is demagnetized and the workpiece 50 is attracted only by the attractive force of the permanent magnet 20. Therefore, even if the electricity is cut off during transportation, the workpiece 50 will not fall. Furthermore, when an external force or the like acts on the workpiece 50 and causes it to fall, the electromagnetic coil 30 serving as an inductance sensor detects the fall of the workpiece 50 as a change in magnetic flux density, so that the workpiece 50 falling can be easily recognized.

When the workpiece 50 reaches the point B in this way, the moving device lowers the workpiece 50 to the point B and releases it.

When this work 50 is released, the electromagnetic coil 30
is excited, and the control device 40 controls the magnetic field of the entire manipulator to be a magnetic field opposite to that during transportation.

Then, this magnetic field is applied to the workpiece 5 that was excited during transportation.
The magnetic field becomes 0 and the opposite magnetic field, and the workpiece 50 is repelled by the manipulator and is momentarily released.

Further, by applying such a reverse magnetic field to the workpiece 50, the magnetic force of the workpiece 50 that was excited during transportation disappears, and the workpiece 50 is released as a non-excited state.

After the workpiece 50 is released in this manner, the manipulator is raised to a position where the influence of the magnetic force of the permanent magnet 20 disappears, and then the electromagnetic coil 30 is demagnetized.

Therefore, in the present invention, since the electromagnetic coil 30 is energized only when the workpiece 50 is released, or when it is released and attracted, the excitation time is extremely short, and the rating of the electromagnetic coil 30 can be set to a small value. can do. Therefore, electromagnetic coil 3
It is possible to extend the lifespan of zero or reduce power consumption.

Furthermore, when the work 50 is transported, the work 50 is transported by the attraction force of the permanent magnet 20, so even if the electricity is cut off, the work 50 is still attracted, and there is a danger that the work 50 may fall during transport. There is no.

Furthermore, in the present invention, since the magnetic flux density can be detected by the electromagnetic coil 30 as an inductance sensor, if the electromagnetic coil 30 is also used as an inductance sensor, the magnetic field generated by exciting the same electromagnetic coil 30 can be reduced. In addition, since it is possible to detect the approach to the work 50 and the fall of the work 50 during transportation due to external force, there is no need to use any other sensor.

In addition, after the workpiece 50 is attracted by the magnetic force of the permanent magnet 20, a reverse magnetic field is gradually applied to the electromagnetic coil 30, and the current value when the workpiece 50 falls, that is, (magnetic force of the permanent magnet 20) - (electromagnetic coil 30) coil 3
If the current value of the electromagnetic coil 30 at which the workpiece 50 falls is found among the values of the magnetic force of 0, immediately after the workpiece 50 is attracted by the magnetic force of the permanent magnet 20, the current value By applying this current, the workpiece 50 that has been taken in two pieces can be dropped, so that taking out two pieces can also be prevented. Work like a hatchet 5
After determining whether or not the workpiece 50 is suitable, accidents such as falling of the workpiece 50 can be prevented by cutting off the current to the electromagnetic coil 30 and transporting the workpiece 50 by the strong magnetic force of the permanent magnet 20.

Furthermore, in the above explanation, the electromagnetic coil 30 is used as an inductance sensor to detect the approach to the workpiece 50, but the approach to the workpiece 50 may also be performed by a separately provided external control. .

Furthermore, at the time of attraction, although it has been explained that the workpiece 50 is attracted by the magnetic force of the permanent magnet 20, the permanent magnet 20
When the electromagnetic coil 30 is excited so that a magnetic force is generated in the same direction as the magnetic force direction, the workpiece 50 is
This allows for adsorption. Of course, at this time, by adjusting the magnetic force of the electromagnetic coil 30, the magnetic force of the electromagnetic coil 30 can be adjusted as a positive or negative value based on the magnetic force of the permanent magnet 20, so that as a result, , the magnetic force of the permanent magnet 20 is controlled by the magnetic force of the electromagnetic coil 30.

[Effects of the invention] As explained above, the invention combines an electromagnetic coil and a permanent magnet, fixes the workpiece by the magnetic force of the permanent magnet, and fixes the workpiece by generating a magnetic field in the opposite direction of the electromagnetic coil. The magnetic force of the permanent magnet can be controlled by the magnetic force of the electromagnetic coil so that the workpiece can be released by canceling the magnetic field of , to improve safety by preventing the workpiece from falling off even if the power is cut off during transportation, and furthermore, when the electromagnetic coil is demagnetized when the workpiece is not attracted, the electromagnetic coil that performs the control is inducted. When used as a sensor, dynamic changes in the magnetic force of a permanent magnet are detected as changes in inductance, thereby making it possible to detect approaching a workpiece or falling of a workpiece during transportation.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, with FIG. 1 being a sectional view and FIG. 2 being a sectional view showing another embodiment. 10... Yoke, 11... Coil hobbin, 12
... Mold, 13 ... Fixing material, 14 ... Cord, 20 ... Permanent magnet, 30 ... Electromagnetic coil, 4
0...control device, 50...work.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A permanent magnet and an electromagnetic coil in which the direction of the magnetic field at the pole part matches the direction of the magnetic field at the pole part of the permanent magnet regardless of whether it is forward or reverse, are fixed with a cover, This electromagnetic coil is equipped with a control device that controls the magnetic force of the electromagnetic coil so that a magnetic field opposite to that of the permanent magnet is generated when the workpiece is released, so that the overall magnetic force can be controlled. A manipulator characterized in that it is used as a release coil when released, and used as an inductance sensor that detects changes in the magnetic field of a permanent magnet as it approaches a workpiece when approaching a workpiece. 2. The manipulator according to claim 1, wherein the electromagnetic coil is controlled by a sweep current. 3. The manipulator according to claim 1, wherein the electromagnetic coil is controlled by a sweep voltage.