JP3382653B2 - Rotary table drive - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary table drive device such as a vertical injection molding machine and a vertical press machine.

[0002]

2. Description of the Related Art As a levitation rotating device for a rotary disk, which is a lower disk of a vertical rotary press, one using a conventional hydraulic pressure and an electric motor has been proposed in Japanese Utility Model Publication No. 2-118694. This will be described below with reference to FIGS. 3 to 5, reference numeral 10 is a lower plate, and an upper plate 14 having four corners connected and supported by tie rods 12 is arranged above the lower plate. A movable plate 16 is provided between the lower plate 10 and the upper plate 14 while being vertically guided by a tie rod 12, and the movable plate 16 is lifted and lowered by a hydraulic cylinder 18 provided on the upper plate 14. It is designed to be punished. Further, a rotary plate 20 is provided on the upper surface of the lower plate 10 facing the movable platen 16, and a rotary shaft 22 is concentrically provided on the lower surface of the rotary plate 20. A rotary shaft holding hole 24 for rotatably holding the shaft 22 is formed. Further, the turntable 20 has the rotation shaft holding hole 2
The rotary shaft 22 is projected into the inside of the lower plate 4 and is mounted on the upper surface of the lower plate 10.

Here, the lower end of the rotary shaft 22 penetrates through the rotary shaft holding hole 24 and the lower end of the rotary shaft 22 projects from the lower base 10.
A large gear 26 is fixedly mounted on the lower end of the rotary shaft 22 protruding therefrom. The large gear 26 meshes with a small gear 30 fixed to the motor shaft of the motor 28, and the rotational power of the motor 28 is transmitted to the rotary shaft 22. The rotary shaft 20 is rotated 180 degrees around the center line of the rotary shaft 22 by the motor 28, and the movable platen 16 is lowered at two rotational positions of the rotary plate 20. On the basis of the above, the two upper dies 32, 32 attached to the movable plate 16 and the two lower dies 34, 34 attached to the rotary plate 20 are simultaneously clamped.

By the way, the rotary shaft holding hole 24 of the lower mold 10 is
As is clear from FIGS. 4 and 5, the lower half portion is a small diameter portion 36 having substantially the same diameter as the rotating shaft 22, and the small diameter portion 3
6, the rotary shaft 22 is slidably fitted to the rotary shaft 22, and its upper half portion is a large diameter portion 38 having a diameter sufficiently larger than the diameter of the rotary shaft 22. 10
An annular groove opening upward is formed between the rotary shaft holding hole 24 and the rotary shaft 22. And here,
The opening of the annular groove is closed by an annular closing member 40 slidably fitted to the rotary shaft 22, and the rotary shaft holding hole 2 is formed.
A cylindrical closed space is formed between the rotary shaft 4 and the rotary shaft 22. On the other hand, on the outer peripheral surface portion of the rotary shaft 22 corresponding to the cylindrical hermetically closed space, an annular projection 42 having substantially the same diameter as the large diameter portion 38 of the rotary shaft holding hole 24 is formed. The ridge 42 is slidably fitted in the large diameter portion 38 of the rotary shaft holding hole 24. As a result, the cylindrical closed space is vertically separated by the ridge 42, and two annular liquid chambers 44, 46 are formed above and below the ridge 42.
A bearing 52 for allowing relative rotation between the ridge 42 and the closing member 40 is disposed in the liquid chamber 44 above the ridge 42.

In the turntable 20, the protrusion 42 is the bearing 5
When the rotary plate 20 is placed on the lower plate 10, the downward movement is restricted based on the contact with the closing member 40 via the two. Movement is regulated. Further, when the rotary shaft 22 is moved to its upper limit position, the rotary disk 2
0 can be floated from the lower plate 10 by a predetermined minute distance. Also, as shown in FIGS. 4 and 5,
Communication holes 48, 50 are formed through the lower plate 10 in a state of opening in the liquid chambers 44, 46 separated by the ridge 42, respectively, and the upper liquid chamber 44 is connected to the tank through the communication hole 48. The lower liquid chamber 46 is connected to a hydraulic pressure source through the communication hole 50, and pressure oil is supplied from the hydraulic pressure source to the lower liquid chamber 46. The hydraulic oil leaking from the lower liquid chamber 46 to the upper liquid chamber 44 side is collected in the tank through the communication passage 48.

An annular third liquid chamber 54 is provided between the rotary shaft 22 and the small diameter portion 36 of the rotary shaft holding hole 24 slidably fitted to the rotary shaft 22. Third liquid
A communication hole 56 is provided in the lower plate 10 so as to open in the chamber 54 . Further, the third liquid chamber 54 is connected to the tank through the communication hole 56, and the liquid chamber 46 to the third liquid chamber 5 are connected.
The hydraulic oil that leaks to the No. 4 side is collected in the tank through the communication hole 56. The gap between the protrusion 42 of the rotary shaft 22 and the rotary shaft holding hole 24 and the rotary shaft 22.
The gap between the rotary shaft holding hole 24 and the small diameter portion 36 of the rotary shaft holding hole 24 is set to be sufficiently small so that the hydraulic pressure of the liquid chamber 46 can be held well.

Further, the portions between the closing member 40 and the rotary shaft 22 and between the rotary shaft 22 and the rotary shaft holding hole 24 below the third liquid chamber 54 are shown in FIG. 5, respectively. The ring-shaped sealing materials 58 and 60 are arranged so that
The leakage of hydraulic oil between them is prevented. In such a rotary press machine, when the rotary disk 20 is rotated, the hydraulic source is connected to the communication hole 5
The pressure oil is supplied to the liquid chamber 46 through 0, and hydraulic pressure is applied to the lower surface of the protrusion 42 of the rotary shaft 22 to move the rotary shaft 22 to the position where the protrusion 42 contacts the closing member 40 via the bearing 52. To raise. That is, the turntable 20 is levitated from the lower plate 10.

In this way, since the rotary plate 20 does not come into sliding contact with the lower plate 10 when the rotary plate 20 rotates, the resistance of the lower plate 10 to the rotation of the rotary plate 20 is greatly reduced, The power required for the rotation of the turntable 20 and thus the motor 28 as a rotation drive device for driving the turntable 20 to rotate can be small. In addition, the turntable 20 and the bottom 10
Since the and are not in sliding contact with each other, abrasion due to their sliding is avoided, the durability of the rotary disc 20 and the lower disc 10 is significantly improved, and the rotary disc 20 and the lower disc 10 are excellent in durability. In order to secure the sliding performance, it is not necessary to dispose expensive sliding metal on those sliding surfaces. When the upper molds 32, 32 are clamped against the lower molds 34, 34, the hydraulic pressure in the liquid chamber 46 is released, the rotary shaft 22 is lowered, and the rotary disc 20 is placed on the lower mold 10. The Rukoto.

[0009]

In the above-mentioned conventional example, since hydraulic pressure is used for the means for floating the rotary table, there is a possibility of oil leakage from the seal portion. Further, since the means for floating the rotary table and the means for rotating the rotary table must be separately provided, the size of the machine becomes large and the cost becomes high. The present invention has been proposed to solve the above conventional problems.

[0010]

Therefore, the present invention provides
When pressing force from one side, support it by contacting the lower fixing member.
If there is no pushing force from above, lift it slightly upward.
Rotation that drives a rotating table that rotates around a vertical axis
In the table driving device, the same as the upper surface of the fixing member
Provide multiple annular grooves on the circumference so that the top surface becomes the magnetic pole surface
Attaching a different electromagnet core, and rotating it at a position facing it
On the lower surface of the table, provide similar annular grooves on the lower surface.
Attach an electromagnet core so that the magnetic pole surface comes, and attach both electromagnet cores.
Insert the levitation excitation windings into the annular grooves of
Apply currents to the levitation excitation winding in opposite directions to face each other.
Repulsive force between the two electromagnets
By passing an alternating current above or below the annular groove
The levitation coil for rotation that generates a rotating magnetic field
The winding is inserted into the excitation winding and the rotation excitation winding is also inserted.
The fixing member facing the electromagnet core into which
Is a non-magnetic, good conductive material on the facing surface of the rotary table.
Plate is attached, and stopper pins are attached to the rotary table.
Attach it and attach the stopper pin to the fixing member.
Position and stop the rotary table at a predetermined position
The feature is that a stopper bar is attached. Also,
Ming touches the lower fixing member when it receives pushing force from above.
It is supported by a hand and is held slightly upward when there is no pushing force from above.
Drives a rotary table that is lifted and rotates around a vertical axis
In the rotary table drive device,
A plurality of annular grooves are provided on the same circumference on the surface
Attach an electromagnet iron core that
On the lower surface of the rotary table, a plurality of similar annular grooves are provided.
Attach the electromagnet iron core so that the magnetic pole surface is on the bottom
Insert the levitation excitation winding into the annular groove of the magnet core,
When rotating the rotary table, these floating
Both sides of the magnetizing winding are opposed to each other by applying currents in opposite directions.
In order to generate a repulsive force between the electromagnet cores,
When fixing the table, these levitation excitation windings
Applying a current to only one of the
To create an attractive force, and
A rotating magnetic field is not generated by passing an alternating current to either the top or bottom.
Rotational excitation winding such as
Together to insert, the said rotating excitation winding is inserted
The non-contact surface of the electromagnet core facing the electromagnet core is
A feature is that a plate made of a magnetic material and a good conductive material is attached.
Further, the present invention is such that when the pressing force is applied from the upper side,
It is supported in contact with the member, and if there is no pushing force from above,
Rotation table that is slightly lifted up and rotates around the vertical axis.
In the rotary table drive device for driving the
The upper surface of the fixed member is provided with multiple annular grooves on the same circumference.
Attach the electromagnet iron core so that becomes the magnetic pole surface, and face it
On the lower surface of the rotary table at the position where
-Shaped groove is installed to remove the electromagnet core so that the magnetic pole surface comes to the bottom.
And the exciting windings for levitation in the annular grooves of both electromagnet cores.
When inserting and rotating the rotary table,
Apply currents to these levitation excitation windings in opposite directions.
A repulsive force is generated between the two electromagnet cores facing each other.
Alternating current is flown above or below the facing annular groove.
A rotating excitation winding that produces a rotating magnetic field.
Insert it while stacking it on the levitation excitation winding and
For opposing the electromagnet core into which the excitation winding is inserted.
A plate made of non-magnetic and good conductive material is placed on the facing surface of the electromagnet core.
When mounting and stopping the rotation of the rotary table
Is characterized by switching the connection of the excitation winding for rotation.
To do.

[0011]

[Action] emerged that generates a repulsive magnetic field for levitation rotating table
When no current is flowing through the excitation winding , the rotary table rests on the fixed member and is stably fixed by its own weight. When a current flows through the levitation excitation winding , electromagnets incorporated in both the rotary table and the fixed member generate magnetic fields that repel each other, and the rotary table floats at intervals corresponding to the strength of the magnetic field. In addition, the rotating table generates a rotating magnetic field for rotating the table while the table remains floating.
When a current is passed through the excitation winding , the rotary table starts rotating. Here, when the table comes to a predetermined position, the rotary table is fixed on the fixed member by cutting off the currents of both the levitation and rotation windings. Further, when it is desired to more firmly fix the rotary table, it is possible to excite only one of the levitation electromagnets to generate a strong attractive force between the rotary table and the fixed member.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments of the drawings. FIGS. 1 and 2 show an example in which the present invention is applied to a mold rotary table of a vertical injection molding machine or the like. In the figure, 1 is a fixed base, and a plurality of vertical tie bars 3 attached to the fixed base.
The upper movable mold plate and injection unit (not shown) are supported by. In the plain bearings 11 and 13 attached to the fixed base 1, the central shaft 9 freely rotates,
It is vertically supported so that it can move up and down. The rotary table 5 is attached to the central shaft 9 by a stop plate 15. 7 is a mold (lower mold). An annular electromagnet core 21 is horizontally attached to the fixed base 1, and an excitation winding is formed by two annular grooves inside and outside the upper surface of the electromagnet core 21 and a plurality of evenly-spaced and radial grooves connecting the grooves. Lines 25,2
A plurality of annular spaces into which 9 can be inserted are formed. An exciting winding 25 is fitted in the annular space, and when a current flows through the winding, the electromagnet iron core 21 becomes an electromagnet, and the magnetic pole 2 of the iron core 2 is inserted.
If 1a is an N pole, the magnetic poles 21b and 21c will be S poles. An electromagnet iron core 23 is attached to the lower surface of the rotary table 5 facing the electromagnet iron core 21 of the fixed base 1, and a groove for the excitation winding facing the groove of the electromagnet iron core 21 is provided in this. The exciting winding 27 is inserted in the annular space formed by the groove, and the winding of the exciting winding 27 is wound so that a current flows in the opposite direction to the exciting winding 25 on the fixed side. When an electric current flows through the electromagnet core 2
3 is an electromagnet, the magnetic pole 23a is an N pole, and the magnetic poles 23b, 2
3c becomes the south pole. That is, at the position where both electromagnets are attached, current flows through both exciting windings so that both electromagnets repel each other, and the repulsive force causes the rotary table 5 to rise. A copper plate 31 (or an aluminum plate) is attached to the lower surface of the electromagnet iron core 23.

FIG. 2 is a view of the electromagnet on the fixed base 1 seen from above, and the excitation winding 25 for repulsive levitation is on the right side of FIG.
(This winding 25 is inserted in all the magnetic poles 21a of the iron core 21), and when a current flows from the DC power supply 33, the magnetic pole 2
Although 1a is drawn so as to have an N pole, an AC power supply may be used as the power source, and in-phase AC may be sent to the fixed side electromagnet and the rotary table side electromagnet to repel them. When the electric current is cut off, the upper and lower electromagnet cores 21 and 23 are in contact with each other with the copper plate 31 interposed therebetween. If an electric current is passed through only one side to exert an electromagnetic force, the rotary table 5 is more firmly attracted. In this case, the exciting winding 29 for rotation is fitted in the annular space of the stationary electromagnet core 21 so as to overlap the exciting winding 25. As shown on the left side of FIG. 2, U of the three-phase AC power supply 35,
The V and W phase wirings are sequentially connected to the excitation winding 29 of the magnetic pole 21a. Since each of the U, V, and W phases of the AC power supply 35 has a phase difference of 120 °, when AC flows through the excitation winding 29, a rotating magnetic field is generated in the electromagnet core 21, and the rotating magnetic field is mounted on the rotary table 5 side. An induced magnetic field is generated in the copper plate 31 that is drawn, and this is attracted to the rotating magnetic field of the lower electromagnet,
If the rotary table 5 is floating, it is rotated. The rotary table 5 is positioned by the fixed-side stopper bar 43 and the stopper pin 41 attached to the rotary table 5. Further, when the inertial weight of the rotary table 5 is large, it is possible to use the brake of the rotary table 5 by switching the alternating current phase of the exciting winding 29 to generate a reverse rotating magnetic field while the rotary table 5 is rotating.

The operation of the embodiment configured as described above will now be described. When rotating the rotary table 5 to change the position of the mold 7 mounted on the upper surface, the excitation winding 25,
When a current is applied to 27 to excite the electromagnet iron cores 21 and 23, magnetic fields repelling each other are generated in both electromagnets, and the rotary table 5 floats. Next, apply an alternating current to the excitation winding 29,
When a rotating magnetic field is generated in the electromagnet core 21, an eddy current is excited in the copper plate 31 to induce a magnetic field, the rotary table 5 starts to rotate, and the stopper pin 41 contacts the stopper bar 43 and stops at a predetermined position. Further, when the inertial weight of the rotary table 5 including the mold 7 is large, the connection of the excitation winding 29 is switched during the rotation, and a rotating magnetic field in the opposite direction is generated to act as a brake of the rotary table 5. You can also After confirming that the rotary table 5 is at the predetermined position, the current of the exciting windings 25, 27, 29 is cut off, so that the rotary table 5 lands and stabilizes. In addition, at the time of changing the mold position next time, after the rotary table 5 is floated in the same manner as described above, the connection of the exciting winding 29 is switched and rotated in the opposite direction to return to the initial position.

[0015]

As described in detail above, the present invention uses an electromagnet as a means for levitating a rotary table, so there is no possibility of oil leakage and it is suitable for installation in a clean environment. . Also, the means for rotating the rotary table can be incorporated in the same structure as the levitation means, so the equipment is simple and the size can be kept small,
A small area is also required for the installation location, so cost can be reduced. Further, since the drive means of the rotary table is a direct drive, the energy consumption is low and efficient.

[Brief description of drawings]

FIG. 1 is a sectional view of a rotary table driving device according to an embodiment of the present invention.

FIG. 2 is a plan view of an electromagnet according to an exemplary embodiment of the present invention.

FIG. 3 is a side view showing an entire rotary press provided with a conventional rotary table.

FIG. 4 is a partially cutaway sectional view of a main part in FIG.

5 is an enlarged cross-sectional view of the main part of FIG.

[Explanation of symbols]

1 Fixed base 5 turntable 9 central axis 11,13 Plain bearing 21,23 Electromagnetic iron core 21a, 21b, 21c magnetic poles 23a, 23b, 23c magnetic poles 25,27 Excitation winding (for levitation) 29 Excitation winding (for rotation) 31 copper plate

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) B23Q 1/52 B23Q 5/10 B29C 43/08 B29C 45/06

Claims (3)

(57) [Claims] 1. A rotary table which is supported by contacting a lower fixing member when a pressing force is applied from above, and is slightly lifted upward and rotated about a vertical axis when no pressing force is applied from above.
In a rotary table drive device for driving a rotary table , a plurality of annular grooves are provided on the upper surface of the fixed member on the same circumference, and an electromagnet iron core whose upper surface serves as a magnetic pole surface is attached to the rotary table. the lower surface of the mounting of the electromagnet core, such as coming pole face on the lower surface provided with a similar plurality of annular grooves, inserting the respective levitation field winding in an annular groove of the two electromagnets core, these levitation excitation windings by applying a current in the opposite direction so as to produce a repulsive force between the two electromagnets facing, and the upper or lower annular groove being the opposite, rotating magnetic field is generated by the flowing of exchanges each other the rotating field winding as well as inserted superimposed on the levitating excitation winding, before
The rotating magnet winding is placed opposite to the electromagnet core in which it is inserted.
A plate made of a non-magnetic and good conductive material is attached to the facing surface of the fixed member or the rotary table, and the plate is attached to the rotary table.
Attach the stopper pin and attach it to the fixing member.
Position the stopper pin and set the rotary table
A rotary table drive device having a stopper bar for stopping at a position . 2. The lower fixing part when a pressing force is applied from above.
It is supported in contact with the material, and when there is no pressing force from above,
Rotating table that is slightly lifted and rotates about a vertical axis
In the rotary table drive device that drives the
By providing multiple annular grooves on the same circumference on the upper surface of the member,
Attach an electromagnet core that will become the magnetic pole surface and face it.
On the underside of the rotary table in
Attach an electromagnet core with a groove so that the magnetic pole surface comes to the bottom surface
Leaving excitation windings in the annular grooves of both electromagnet cores.
When inserting and rotating the rotary table, this
These levitation excitation windings are paired by applying currents in opposite directions.
So that a repulsive force is generated between the two electromagnet cores facing each other,
When fixing the rotary table, the
Both electromagnets iron facing each other by passing current through only one side of the excitation winding
To generate a suction force between the hearts and to oppose each other
Rotating magnetic field is generated by passing an alternating current either above or below the annular groove.
A rotating excitation winding that causes a field
And the excitation winding for rotation is inserted.
Facing the electromagnet core Opposing surface of electromagnet core
Is equipped with a plate made of non-magnetic, good conductive material
And a rotary table drive device. 3. The lower fixing part when a pressing force is applied from above.
It is supported in contact with the material, and when there is no pressing force from above,
Rotating table that is slightly lifted and rotates about a vertical axis
In the rotary table drive device that drives the
By providing multiple annular grooves on the same circumference on the upper surface of the member,
Attach an electromagnet core that will become the magnetic pole surface and face it.
On the underside of the rotary table in
Attach an electromagnet core with a groove so that the magnetic pole surface comes to the bottom surface
Leaving excitation windings in the annular grooves of both electromagnet cores.
When inserting and rotating the rotary table, this
These levitation excitation windings are paired by applying currents in opposite directions.
A repulsive force is generated between the two electromagnet cores facing each other, and
An alternating current can be flown either above or below the facing annular groove.
In front of the excitation winding for rotation such that a rotating magnetic field is generated by
The levitation excitation winding is overlaid and inserted into
The electric field facing the electromagnet iron core in which the excitation winding is inserted
A plate made of non-magnetic and good conductive material should be installed on the facing surface of the magnet core.
When stopping the rotation of the rotary table,
The connection of the rotating excitation winding is switched.
Rotary table drive.