JPH0787686B2 - DC motor for rolling mill - Google Patents

Description

The present invention relates to the structures of a DC motor for driving a main roll and a DC motor for winding, which are used in a rolling mill system.

[Conventional technology]

Conventionally, a DC motor or a winding DC motor used for driving a main roll of a cold rolling mill is used for rolling a thick rolled sheet material to a thin desired sheet thickness, and thus has a wide range of rotation speeds.
Used for high frequency acceleration / deceleration, reverse rotation, and severe rolling torque. As the load condition of the motor, 175% of the rated load (100%) is always used.

In addition, in recent years, due to the improvement in productivity, the capacity of rolling equipment has been increased,
The speed is increased and automation is being promoted by centralized control by a computer.

Against this background, the DC motor has a low inertia and good rectification so that the structure is robust against repeated peak loads and that acceleration and deceleration can be performed rapidly. The low inertia shortens the acceleration / deceleration time, improves the productivity per unit time, increases the speed control response, and improves the product quality.

Good straightening not only reduces the trouble of straightening around the brush, but also improves the quality of rolled products. That is, for example, when the commutating pole magnetic velocity becomes non-linear with respect to the load current and the necessary commutating pole magnetic flux changes in the direction of decreasing, the rectification state becomes insufficient rectification, and the short-circuit current flows to the rectification coil short-circuited by the brush. The magnetic flux generated by the flow of the current acts in the direction of increasing the main magnetic flux. As a result, the rotation speed of the DC motor is reduced. Next, when the required magnetic flux amount changes in the increasing direction, the rectified state becomes over-rectified and the magnetic flux generated by the short-circuit current flowing in the rectifying coil short-circuited by the brush acts in the direction of decreasing the main magnetic flux. . As a result,
The rotation speed of the DC motor increases. In this way, the quality of the rectified state affects the rotation speed of the DC motor, and thus also affects the quality of the rolled product.

It has long been known that large DC motors have a non-spark band movement phenomenon in which the non-spark band position changes with respect to the rotational speed.If no rectification compensation is performed, the rectification state deteriorates,
The spark generated from the brush becomes large, and in the worst case, a flashover accident will occur, which not only damages the DC motor itself, but also damages the product currently being rolled.

A method of compensating for the movement phenomenon of the non-spark zone is disclosed in Japanese Patent Laid-Open No. 62-71.
It is described in Japanese Patent No. 463.

[Problems to be Solved by the Invention]

However, as a result of the experiment, applying the above-mentioned conventional technology,
It was found that the brush produced sparks when operated to an overload region of about 175%, and the desired effect could not be achieved when the desired effect exceeded 100%.

An object of the present invention is to provide a DC electric motor suitable for a rolling mill by compensating for non-spark even when constantly operating up to 175% overload.

[Means for Solving the Problems]

The present invention relates to a DC motor for a rolling mill, an armature, a main pole core and a commutating pole core that are held by opposing yokes surrounding the armature and inject magnetic flux into the armature, and the main pole core. And an adjusting magnetic member that leaks the magnetic flux of the auxiliary pole core to the main pole core at a position deviated to the armature side between the auxiliary pole and the auxiliary pole, and the adjusting magnetic member is the main pole core or the auxiliary pole. It is characterized in that it is joined to one of the iron cores with a gap of 2 to 15 mm.

[Action]

By properly selecting the gap provided in the adjusting magnetic member, the linearity of the compensating pole magnetic flux with respect to the load current can be secured, so the operation can be performed up to the 175% overload range of the rating in the wide variable speed range peculiar to the rolling mill system. In a DC current motor for a rolling mill, which is required to meet the requirements, it is possible to rectify sparks in a band, and the improvement of the rectification state reduces the influence on the change in the rotation speed of the DC motor, thereby improving the quality of rolled products.

〔Example〕

Before explaining the embodiments of the present invention, first, the reasons why the above-mentioned problems occur are repeatedly investigated through various experiments, and the causes are clarified. The results will be briefly described.

FIG. 8 shows a non-spark zone and a saturation polarity characteristic of a conventional DC machine. In the figure, (a) shows the load current (load 100% is 1.0 and pu
Expressed as ) Is plotted on the horizontal axis and the vertical axis is the supplementary pole addition current, showing the non-spark zone during low speed operation and during high speed operation.
As shown in (a) of the figure, the non-spark zone during low-speed operation and during high-speed operation overlaps when the load current is 1.0 (pu) or less, but decreases when the load current becomes 1.0 (pu) or more. At the beginning, especially at 2.0 (pu), the non-spark zone moves in the opposite direction to the demagnetization side of the supplementary pole during low-speed operation, and to the demagnetization side during high-speed operation, so that the two non-spark zones completely disappear.

This means that the conventional DC machine can compensate for the reduction of the spark belt movement only by the DC machine body up to the vicinity of the rated load, but cannot compensate in the overload region. As a result of examining various causes in various experiments, as shown in FIG.
The amount of magnetic flux of the pole compensating pole with respect to the load current is in a proportional relationship at a light load, but becomes non-linear at an overload. Especially, at the time of low speed operation, the amount of the magnetic flux of the auxiliary pole becomes non-linear with respect to the load current from point A in the figure, and saturates as the load current increases. On the other hand, the supplementary magnetic flux amount during high-speed operation became non-linear with respect to the load current from point B in the figure, and the rate of increase increased as the load current increased.

The non-linearity of the commutation pole flux with respect to this load current determines the position of the non-spark zone at the load current of 2.0 (pu) in Fig. 9 (a).

Next, the cause of the non-linearity of the commutating pole magnetic flux with respect to the load current will be described.

FIG. 9 is a developed view of the main part of the DC motor showing the characteristics shown in FIG. 8, and shows the flow of the auxiliary pole magnetic flux Φ _IP , the main magnetic flux Φ _MP , and the leakage magnetic flux Φ _LP . In the figure, when only the open magnetic winding 5 is excited, in addition to the main magnetic flux Φ _MP , a leakage magnetic flux Φ _LP that short-circuits the main pole cores 4 via the short-circuiting iron core 10 is generated.

Next, when only the commutating pole winding 9 is illustrated, a commutating pole flux Φ _IP is generated, and Φ _IP1 passing through the short-circuit iron core 10B, Φ _IP2 reaching the armature 6, the short-circuit iron core 10A, and the main pole iron core 4 are used to drive the electric machine. Φ _IP3 leading to child 6
To occur.

When the field winding 5 and the auxiliary pole winding 9 are excited, the short-circuited iron core 10A
As the magnetic flux passing through the, there is a leakage flux [Phi _LP, interpole magnetic flux [Phi _IP3, magnetic flux passing through the short-circuit core 10A in magnitude of field magnetomotive force AT _F and HokyokuOkoshi force AT _IP is almost determined.

That is, when the field magnetomotive force AT _f > the commutating pole magnetomotive force AT _IP is satisfied, the leakage flux passing through the short-circuited iron core 10A is in the direction from the main pole core 4 to the commutating pole core 8 and the commutating pole flux Φ _IA is If the relationship is such that the field magnetomotive force AT _f <reverse pole magnetomotive force AT _IP increases, on the contrary, the leakage flux passing through the short-circuited iron core 10A becomes the direction from the main pole core 8 to the commutator pole 4 and the commutation pole flux. Φ _2A decreases.

In the operation of the DC motor for rolling mills, the voltage is accelerated up to a specified speed by voltage control, and thereafter, it is accelerated by field control. Under such an operation, the magnitude relationship between the field magnet force AT _f and the commutator magnet force AT _IP changes arbitrarily. Therefore, due to the reasons described above, the commutator magnetic flux may become non-linear with respect to the load current. found.

The present invention, due to the leakage flux caused by short-circuiting the main pole and the auxiliary pole with the short-circuit iron core, in view of impairing the linearity of the amount of the auxiliary pole magnetic flux during operation, particularly in the overload region,
The intended purpose is achieved by providing an adjusting magnetic member capable of adjusting the magnetic resistance of the magnetic circuit via the short-circuited iron core.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

FIG. 1 shows a schematic system configuration of a reversing type cold rolling mill to which the present invention is applied. In the figure, 11 is a rolling mill, 12 is a DC motor for driving a main roll, 13 and 14 are DC motors for winding, 15 and 16 are tensiometers, 17 and 18 are thickness gauges, 19 is a static Leonard control device, and 20 is A rolling control device, 21 and 22 are deflector rolls, 23 is a rolled plate material, and 24 and 25 are tension reels. In such a configuration, the rolled plate material 23 is rolled by pressing the reduction roll of the rolling mill 11 by the reduction control device 20 and driving the main roll pressed by the reduction roll by the main roll driving DC motor 12. To be done. Rolled sheet material 23
Is wound on a tension reel 24 via a deflector roll 21, and this tension reel 24 is a DC motor for winding.
Driven at 14. The DC motor 12 for driving the main roll is operated by the stationary Leonard controller 19, and a signal from the thickness gauge 17 is obtained to control the rotation speed to a desired value via the automatic plate thickness control AGC and the automatic speed control ASR. Further, the DC motor 14 for winding is similarly operated by the stationary Leonard controller 19, and a signal from the tensiometer 15 is obtained to be controlled to a rotation speed at which a desired tension is obtained via the automatic tension control ATR. . Also,
In the case of reverse rotation, the same control and operation are performed.

In such a configuration, the change in speed of the DC motor itself becomes a disturbance to the stationary Leonard control device 19, and affects the product quality of the rolled plate material 23. In addition, the DC motor for driving the main roll 12
When the winding electric motors 13 and 14 reach a flashover accident, the plate material 23 currently being rolled becomes a defective product, which has a great influence.

Therefore, a DC motor for driving a rolling mill is desired to have a self-adjusting action of the commutating pole magnetic flux that can compensate for the non-spark zone movement phenomenon even in the overload region.

FIG. 2 shows a cross-sectional view of the main parts of a DC machine that is an embodiment of the present invention. It should be noted that the same parts as those of the related art are denoted by the same reference numerals, and the description thereof will be omitted. In the figure, a commutating pole core 8 and an adjusting magnetic member 10 (10A, 10B) are integrally formed, and a gear gap 1 _G1 is provided between the member 10 and the magnetic pole piece 4A of the main pole core 4.
FIG. 3 shows the operation during such low speed operation and high speed operation in such a configuration.

The figure (a) shows the low speed operation, and the (b) shows the high speed operation. Φ _MP (Φ _MP1 , Φ _MP2 ) is the main magnetic flux and Φ _IP (Φ _IP1 ~
Φ _IP3 ) is the commutation pole flux, and Φ _IA (Φ _IA1 , Φ _IA2 ) is the rectification compensation flux for generating rectification electromotive force. The same figure (a)
During low speed operation, the compensating magnetic flux Φ _IP1 leaks to the main pole core 4 of the S pole through the adjusting magnetic member 10B and the gear 1 _G1 as in the conventional case, and the commutating magnetic pole Φ _IP2 enters the armature 6 side. And
The field magnetomotive force AT _F is increased by the strong field, and the competing magnetomotive force A in the overload region A
Since it is set to be larger than or equal to T _IP , the auxiliary pole magnetic flux Φ _IP3 is applied to the gear gap from the main pole core 4 of the N pole.
1 _G1 enters the commutating pole core 8 through the adjusting magnetic member 10A and enters the armature 6 side. As a result, the commutation compensating pole flux Φ
_IA1 becomes larger as the sum of the commutation pole fluxes Φ _IP2 and Φ _IP3 .
On the other hand, during high speed operation in Fig. 2B, the commutating pole flux Φ
_IP1, for [Phi _IP2 is flowing in the same manner as shown in (b), for field magnetomotive force AT _F is less than HokyokuOkoshi force AT _IP field weakening, interpole magnetic flux [Phi _IP3 adjustment magnetic member Leak to the main pole core 4 of the same pole (N pole) via 10A and the gear 1 _G1 . As a result, the commutating pole flux Φ _IP for rectification compensation becomes
_IP2 only makes it smaller.

That is, in the present invention, the main pole core 4 and the adjusting magnetic members 10A, 10
By providing a gear 1 _G1 with B, the magnetic pole is adjusted to reduce the commutation pole flux Φ _IP1 through the member 10B, and the commutation pole flux Φ _IP3 that passes through the adjustment magnetic member 10A to the overload region during low speed operation. Is linearly adjusted, and the self-adjusting action of the magnetic flux of the compensating pole compensates for the non-spark zone movement phenomenon. Further, since the magnetic saturation of the magnetic circuit is not used in the overload region, the amount of the magnetic flux of the commutating pole with respect to the load current changes linearly.

FIG. 4 shows the auxiliary pole saturation characteristic and the non-sparking band of the DC machine of the present invention, in which the gear gap l between the adjusting magnetic member 10 and the main pole core 4 is shown.
_This is the case when the experiment was performed with _G1 = 7.5 mm. As shown in (a) of the figure, the amount of supplementary magnetic flux with respect to the load current is 2.0 (p.
u) linearly changed, and the difference in the amount of magnetic flux of the auxiliary pole between low speed operation and high speed operation became proportional to the load current. As a result, as shown in (b) of the same figure, the load current of 2.0 (p.
It has been revealed that it is possible to completely compensate for the spark-zone movement phenomenon by using only the DC machine itself.

However, there is an optimum range of gear length to linearize the commutation pole flux up to the load current of 2.0 (pu) in the overload region, and it is not enough to linearize the relationship between the commutation pole flux and the load current. Therefore, it is important that there is a wide non-spark zone common to low-speed operation and high-speed operation at a load current of 2.0 (pu). Therefore, the overlapping width of the non-spark zone at low speed operation and high speed operation at a load current of 2.0 (pu) for the gear length l _G1 was examined.

In FIG. 5, the horizontal axis shows the gear length l _G1 , and the vertical axis shows the overlapping width of both non-spark zones during low speed operation and high speed operation at a load current of 2.0 (pu). The overlapping width of 100% means that
It is shown that the non-spark zone during high-speed operation is completely contained in the non-spark zone during low-speed operation, and the overlapping width of 0% is the opposite.

There is no overlapping width of the non-sparking band from the non-linearity of the interpole magnetic flux Giyatsupu length l _G1 than the figure for the load current as described above is 2mm or less, the auxiliary Giyatsupu length l _G1 is the load current at 2mm or more The non-linearity of the polar magnetic flux is improved and the overlapping width of the non-spark zone begins to exist, and when the gear length l _G1 is 6 mm to 9 mm, it becomes 100.
%, Above that, the difference in the amount of magnetic flux between the poles between low-speed operation and high-speed operation decreases, and the width overlaps with the non-spark zone and becomes smaller. At l _G1 = 13 mm or more, it completely disappears.

Therefore, by setting the gear length to l _G1 = 2 mm to 13 mm, the linearity of the amount of magnetic flux of the interpolating pole with respect to the load current is improved, and even in the overload region, there is no spark zone common to low speed operation and high speed operation. Was present, and sparks from the brush could be prevented.

FIG. 6 shows another embodiment of the present invention. What is different from FIG. 1 is that the adjusting magnetic member as shown in FIG.
10 is integrally formed with the main pole core 4, the supplementary pole core 8 and the short-circuit iron 10
It is provided with a gear l _G2 between and. Same figure (b)
Is a case of showing the overlapping width of the non-sparking band against Giyatsupu length l _G2, by setting the Giyatsupu length l _G2 to 4Mm～15mm, non sparking band and a high-speed during operation during low-speed operation overlap width Was present, and sparks from the brush could be prevented.

FIG. 7 shows still another embodiment of the present invention.
The difference from the figure is that a gear gap L _G1 is provided between the adjusting magnetic member 10 and the main pole core 4, and a gear gap L _G2 is provided between the member 10 and the commutating pole core 8. FIG (B) is Giyatsupu length (l _G1 + l _G2) low-speed operation when a high-speed operation by setting the overlap is a case showing the width Giyatsupu length of the non-sparking bands (l _G1 + l _G2) to 2mm~15mm against There was a non-sparking band overlap with the time, and sparks from the brush could be prevented.

According to the above experimental results, a gear tape is provided between at least one of the adjusting magnetic member and the main pole iron core, or between the member and the commutating iron core, and the gear tape length is set to 2 mm to 15 mm. Since the size and direction of the commutating pole flux Φ _IP3 passing through 10 is used to reduce the commutating pole flux amount during high-speed operation compared to during low-speed operation, it is possible to operate in a wide variable speed range and further to the overload area. It was confirmed that there is a common non-spark zone during low-speed operation and during high-speed operation, which has the effect of preventing spark generation from the brush.

In the embodiment of the present invention shown in FIGS. 2 to 7, a magnetic flux adjusting member having a gear cup is provided between the main pole and the auxiliary pole on the armature side. Instead of the gear cup, a non-magnetic member and a magnetic flux adjusting member are provided. Needless to say, they may be connected between the main pole and the auxiliary pole by welding or the like.

〔The invention's effect〕

According to the present invention, by properly selecting the gap provided in the adjusting magnetic member, it is possible to ensure the linearity of the compensating pole magnetic flux with respect to the load current, so that in the wide variable range peculiar to the rolling mill system, the rating of 175% is exceeded. The DC motor for rolling mills, which is required to operate up to the load range, can always perform commutation without sparks, and the improvement of this commutation state reduces the influence on the change in the rotation speed of the DC motor, thus improving the quality of rolled products. effective.

[Brief description of drawings]

FIG. 1 is a schematic system configuration of a reversing type cold rolling mill which is an application product of the present invention, FIGS. 2 to 5 are views for explaining the present invention, and FIGS. 6 to 7 are of the present invention. It is a figure for explaining other examples. FIG. 8 and FIG. 9 are diagrams for explaining a conventional DC motor. 1 ... Yoke, 2 ... Main pole, 3 ... Complement pole, 4 ... Main pole core, 5 ... Field winding, 6 ... Armature, 7 ... Armature winding, 8 ... Complement pole core, 9 ...... Complement pole winding, 10 ... Adjusting magnetic member (short-circuit core in the conventional description), 11 ... Rolling machine, 12 ...
DC motor for driving main rolls, 13,14 …… DC motor for winding, 19 …… Stationary Leonard controller, l _G1 , l _G2 …… Gear cup.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mitsuhiro Nitobe 3-1-1, Saiwaicho, Hitachi, Ibaraki Hitachi Ltd. Hitachi factory (72) Inventor Nobutaka Suzuki 2-chome, Aisemachi, Hitachi, Ibaraki No. 1 in Hitachi Equipment Engineering Co., Ltd. (56) References Actually open 61-202171 (JP, U) Actually open 56-166776 (JP, U)

Claims (1)

[Claims] 1. A rolling machine which is a DC motor (12) for driving a main roll for applying a driving force to a main roll of the rolling machine (11) and a DC motor (13, 14) for winding up a rolled plate material (23). In a DC motor for use, an armature (6) and a yoke (1) surrounding and surrounding the armature (1)
Main pole core (4), which is held by the armature and injects magnetic flux into the armature
And a supplementary pole core (8), and an adjusting magnetic member (10) for leaking the magnetic flux of the supplementary pole core to the main pole core at a position deviated to the armature side between the main pole core and the supplementary pole core. Equipped with
A DC motor for a rolling mill, characterized in that the adjusting magnetic member (10) is joined to either one of the main pole core or the supplementary pole core with a gap of 2 to 15 mm.