JPH0137695B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a power meter, and particularly to the structure of a driving element thereof.

[Technical background of the invention and its problems]

Inductive watt-hour meters ensure that the mutual phase angle between the voltage magnetic flux that is generated in proportion to the power supply voltage and the current magnetic flux that is generated in proportion to the load current is equal to 90 degrees, thereby adjusting the error due to the inductive load. Equipped with an inductive load adjustment device.

The inductive load adjustment device delays the phase angle of the voltage magnetic flux using a short-circuit coil or a short-circuit copper ring interlinked with the voltage magnetic path, and by adjusting this delay angle, the phase angle between the current magnetic flux and the current magnetic flux can be adjusted to 90°. Or, by delaying the phase angle of the current magnetic flux by using a short-circuit coil or a short-circuit copper ring interlinked with the current magnetic path, and adjusting this delay angle, the phase angle with the voltage magnetic flux can be adjusted to 90 degrees. This is done by one of two methods: As a special example, there is also a power meter that uses both of these methods.

A watthour meter having an inductive load adjustment device using a short-circuited copper ring interlinked with a current magnetic path will be described with reference to FIG. FIG. 1 shows the driving elements of such a power meter, including a voltage element consisting of a voltage core 1 and a voltage coil 2, a current core 4 made of laminated silicon steel plates, a current coil winding frame 5 made of plastic, a current coil 6, and a current coil made of plastic. A current coil insulating flange 7 made of a copper plate, an inductive load adjustment punch plate 8 made of a copper plate, a commutating pole 9 made of a magnetic material, a current magnetic shunt 10 made of a magnetic material, and a current magnetic current made of a non-magnetic material that fixes the current magnetic shunt. It has a configuration in which a current element consisting of a shunt fixing plate 11 is coupled with a yoke 3 made of a magnetic material. The voltage iron core 1 and the current iron core 4 are connected to the yoke 3 with a slight gap between their opposing surfaces.
A rotating disk (not shown) rotates within this gap.

As shown in FIG. 1, the inductive load adjustment punch plate 8 has a U-shaped current core 4 in a pair of square holes.
Both legs of the inductive load adjustment punch plate 8 are inserted and attached so as to interlink with the current iron core forming a current magnetic path, but the inductive load adjustment punch plate 8 comes into close contact with the current iron core 4 and there is no insulation between them.

In recent years, electro-deposition coating technology has developed, and it has become convenient to coat the object by simply passing it through a paint tank to which a predetermined voltage has been applied. It is expected that it will be used in products using laminated iron cores. In addition, the advantage of electrodeposition coating is that the areas to which no voltage is applied,
In other words, parts that are electrically insulated from insulators or parts to be painted should not be painted.

When this electrodeposition coating is applied to the driving element portion of a watt-hour meter, the most efficient method is to apply it with a voltage element and a current element combined as shown in FIG. On the other hand, the inductive load adjustment punch plate 8
This is done by cutting the punching margin 8b with a punching tool or the like and adjusting the resistance value of the punch plate, but if too much is cut or the error changes over time, the cut portions must be reconnected. In some cases, soldering may be necessary.

Therefore, in a structure where the inductive load adjusting punch plate 8 is in contact with the current iron core 4 as in the conventional example shown in FIG. 1, when electrodeposition coating is performed in the state shown in FIG. It had the disadvantage that it could not be soldered because voltage was applied to it and it was painted.

Methods for electrically insulating the inductive load adjustment punch plate 8 and the current core 4 include applying insulation coating to only the portion of the punch plate that contacts the current core, or interposing an insulator between the current core and the punch plate. Although there are methods such as painting, all of them involve difficult work, and for this reason, in the past, the current iron core 4 was painted alone and then assembled into the shape shown in Fig. 1. If the iron core is painted alone and then combined with other parts, the paint will come off partially as the iron core rubs against other metal parts during assembly, causing rust to occur later. Additionally, during assembly, fine metal powder and coating powder remain due to the rubbing of metal parts, which has a fatal negative effect on the rotating parts of the watt-hour meter. This defect occurs concentratedly at the insertion portion of the current-magnetic shunt 10 and the commutative pole 9 shown in FIG. This is caused by contact with the foreign powder. Furthermore, the foreign powder may enter a bearing (not shown).

[Purpose of the invention]

The present invention provides a watthour meter having a drive element configured such that an inductive load adjustment punch plate is insulated from a current iron core, and equipped with a drive element that can be electroplated after the drive element is assembled. With the goal.

[Summary of the invention]

In the present invention, the shape of the plastic current coil winding frame is such that a pair of rectangular tubes into which the current coil is fitted pass through a brim-shaped flat plate part and protrude for a required length on the back side of the flat plate part to form a protruding part. After fitting the inductive load adjusting punch plate into the protruding part, the protruding part is heated and bent outward to form the inductive load adjusting punch plate into the flat part of the current coil winding frame. The inductive load adjustment punch plate and the current iron core are separated and insulated by the bending part, and electrodeposition coating is applied with the drive element assembled. The intended purpose was also achieved by preventing the inductive load adjustment punch plate from being painted.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 2 and 3 show driving elements of a power meter according to an embodiment of the present invention. Note that parts equivalent to those in FIG. 1 are given the same reference numerals. FIG. 3 shows the details of the shape of the main components of the current element and the direction of insertion of each component during assembly with arrows.

In FIG. 3, the current iron core 4 is a substantially U-shaped stack of silicon steel plates, and grooves 4a and 4b are provided near both ends of the U-shape, respectively. The current coil winding frame 15 is a plastic molded product, and the current coil 6
A pair of rectangular tubes 15a into which are externally fitted is a brim-shaped flat plate portion 1
The protrusion 15c is formed by penetrating through the protrusion 15b and protruding a required length to the back side of the flat plate part. The current coil 6 is made by winding an enameled wire with a diameter corresponding to the rated current of the watt-hour meter with a number of turns corresponding to the rated current.In order to reduce the voltage drop in the current circuit, a relatively thick enameled wire is used. It is wound several to several dozen times. For this reason, the current coil 6 is generally formed into a coil shape in advance and fitted onto the rectangular tube 15a of the current coil winding frame 15. The current coil insulating flange 7 is made of a rectangular plastic plate having approximately the same size as the flat plate portion 15b of the current coil winding frame 15, and has two square holes 7a into which the square tube 15a of the current coil winding frame is inserted.
The inductive load adjustment punch plate 8 has two square holes 8a in the copper plate into which square tubes 15a of the current coil winding frame 15 are inserted.
A part of this square hole is extended to the front to form a shape as shown in FIG. 3, and an adjustment punch allowance 8b is provided.

Next, a method of assembling the current element will be explained. As shown by the arrow in FIG. 3, the rectangular tube 1 of the current coil winding frame 15
A current coil 6 is fitted onto each of the current coils 5a, and then a current coil insulating flange 7 is attached. On the other hand, the protruding portion 15c on the back side of the flat plate portion 15b of the current coil winding frame 15
Attach the inductive load adjustment punch plate 8 by fitting it into the square hole 8a. In this state, as shown in FIG. 2, the upper end 15e of the rectangular tube 15a and the end of the protrusion 15c of the current coil winding frame 15 are heated with ultrasonic waves or a heating iron such as a heater so that they move from the inside to the outside. Compress while expanding. As a result, as shown in a partial cross section in FIG. 2, the upper end 15e of the rectangular tube 15a is configured to sandwich the current coil insulating flange 7 with the current coil 6, and the end of the protrusion 15c is configured to adjust the inductive load. The punch plate 8 is formed so as to be sandwiched between the flat plate portion 15b of the current coil winding frame 15.

Next, the current iron core 4 is attached to the rectangular tube 1 of the current coil winding frame 15.
5a from below, and then as shown in FIG.
a, 4b, and the current magnetic shunt fixing plate 11 to which the current magnetic shunt 10 is fixed is attached to the current iron core 4.
Insert between the inner groove 4a and the commutating electrode 9. next,
The assembled current element and voltage element are combined by a yoke 3 with a predetermined gap provided between the tip of the current iron core 4 and the tip of the voltage iron core 1 to form a drive element. Next, the assembled drive element is electrodeposited.

Next, the operation of the electricity meter having the above configuration will be described. The voltage magnetic flux generated by the voltage coil 2 is supplied by the voltage iron core 1, and the current magnetic flux generated by the current coil 6 is supplied by the current iron core 4 to the opposing air gap between the voltage iron core 1 and the current iron core 4. A moving magnetic field is formed within the device to rotate a rotating disk (not shown).

The inductive load adjustment punch plate 8 delays the phase angle of the current magnetic flux due to the reaction of the eddy current induced by the current magnetic flux. The punch width 8b of the inductive load adjustment punch plate 8 is a flow path for the vortex flow, so if you punch gradually from the end of this part, the cross-sectional area of the flow path will decrease, the length will increase, and the resistance value will increase. Therefore, the eddy current can be gradually reduced, and the delay in the phase angle of the current magnetic flux can be gradually reduced. That is, it is possible to adjust the error in the amount of electric power when an inductive load is applied.

The current commutator 9 serves to facilitate the passage of current magnetic flux to the current-magnetic shunt 10 and to prevent the current coil winding frame 5 from coming off from the current iron core 4. The current coil winding frame 15 serves to electrically insulate the current coil 6 and the current iron core 4, and also to electrically insulate the inductive load adjustment punch plate 8 and the current iron core 4. That is, even if a predetermined voltage is applied to the current iron core 4, voltage iron core 1, yoke 3, etc. during electrodeposition coating, no voltage is applied to the current coil 6 and the inductive load adjustment punch plate 8, and these are coated. It plays a role in preventing The electrodeposited coating covers both iron cores and the metal parts in contact with them, and improves the appearance and has a rust-preventing effect.
This has the effect that the paint enters the minute gaps between the commutating pole 9 and the current magnetic shunt fixing plate 11 attached to the current iron core 4, and completely covers the metal powder in these areas.

Note that the present invention is not limited to the embodiments described above, and can be implemented with various modifications as described below.

[a] When an inductive load adjustment coil is used instead of the inductive load adjustment punch plate 8.

[b] When the yoke 3 also serves as a support frame for supporting bearings, brake magnets, weighing devices, etc.

[c] In a multi-element instrument, when multiple drive elements of the present invention are fixed to a support frame and then electroplated.

[d] The shape of the protruding portion protruding from the back side of the flat plate portion 15b of the current coil winding frame 15 is not made into a rectangular tube shape. An inductive load adjustment punch plate 8 is provided between the current coil winding frame flat plate portion 15b and the current coil winding frame flat plate portion 15b.
After fitting, the punch plate may be sandwiched between the current coil winding frame flat plate portion by thermally deforming the protruding portion.

[Effects of the Invention] As detailed above, according to the present invention, the shape of the current coil winding frame of the current element constituting the drive element of the watt-hour meter is formed by a pair of rectangular tubes into which the current coil is fitted. A protrusion is formed by penetrating the brim-like flat plate part and protruding for a required length on the back side of the flat plate part, and after fitting an inductive load adjustment punch plate into this protrusion, the protrusion is The inductive load adjusting punch plate is heated and bent outward and fixed by being sandwiched between the flat plate part of the current coil winding frame and the bending part, so that the inductive load adjusting punch plate and the current iron core are bent. Since it is isolated and insulated by the molded part, it is possible to insulate the inductive load adjustment punch plate from the current iron core without using a special insulating coating on the inductive load adjustment punch plate or an insulating material dedicated to the inductive load adjustment punch plate. Electrodeposition coating can be performed after all parts constituting the drive element are assembled. As a result, the following effects can be obtained.

[1] Since the metal powder generated when assembling parts is wrapped in a coating film, it is possible to prevent the metal powder from having a fatal adverse effect on rotating parts.

[2] Electrodeposition coating is applied after the parts are assembled, so
Peeling of the coating film due to friction with other parts during assembly can be eliminated.

[3] For those that use screws to connect the core and yoke, the adhesive effect of paint can prevent the screws from loosening over time.

[4] Economical as only one painting job is required.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view of a drive element of a conventional watt-hour meter having an inductive load adjustment punch plate, and FIGS. 2 and 3 are drive elements of a watt-hour meter according to an embodiment of the present invention. FIG. 2 is a partially cutaway perspective view, and FIG. 3 is an exploded perspective view showing the details of the shape of the main components of the drive element in FIG. 2 and the direction of insertion during assembly. 1...Voltage iron core, 2...Voltage coil, 3...Yoke, 4...Current iron core, 15...Current coil winding frame,
15a...square tube, 15b...flat plate part, 15c...
Projection portion, 6...Current coil, 7...Current coil insulating flange, 8...Inductive load adjustment punch plate, 9...Commuting pole, 10...Current magnetic shunt, 11...
...Current magnetic shunt fixing plate.

Claims (1)

[Claims] 1 A U-shaped current core and a pair of square tubes into which this current core is inserted and a current coil is fitted onto the outside pass through a brim-shaped flat plate part and protrude to the required length on the back side of the flat plate part. heating a plastic current coil winding frame having a shape of a section, a current coil insulating flange fitted in a rectangular tube of the current coil winding frame to which the current coil is mounted, and a protruding part of the coil winding frame; a current element having an outwardly bent bent portion and an inductive load adjustment punch plate sandwiched and fixed between a flat plate portion of the current coil winding frame; a voltage element having a voltage coil and a voltage iron core; A watt-hour meter comprising a driving element having a yoke that connects an iron core and the voltage iron core and includes only the iron cores and the metal parts that contact them and is electrodeposited.