JPH0124893Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] This invention relates to electromagnetic devices such as discharge lamp ballasts.

[Background technology]

A first conventional example is shown in FIG. In other words, an electromagnetic device of which this leakage transformer type discharge lamp ballast is an example has primary coils 4 and 2 wound around coil bobbins 2 and 3 around one I-shaped core 1 of the assembled core.
The next coil 5 is passed through, and these are surrounded by the other E-shaped cores 6 and 7 of the assembled core to form an outer iron type.
The shaped iron core 1 forms an abutment part that becomes a leakage path part, and gaps 8 and 9 for impedance setting are formed in the abutment part. The entire assembled iron core is covered with a case and impregnated with varnish for insulation treatment.

The impedance of this electromagnetic device is adjusted by changing the lengths of the gaps 8 and 9. That is, the magnetic resistance R of this electromagnetic device is expressed by the following equation since the magnetic permeability μ of the iron core is much larger than the magnetic permeability μ ₀ of air. That is, R=(1/S)×{(i/μ)+(g/μ ₀ )} ≒g/S μ ₀ where S is the magnetic path cross-sectional area, i is the magnetic path length, and g
is the void length. From this equation, the impedance can be adjusted by changing the gap length g.

In this case, the lengths of the gaps 8 and 9 are adjusted by hitting the outer surfaces of the E-shaped cores 6 and 7 from the sides as indicated by arrows A and B in the figure to adjust the gap length g. However, the following problems arose. That is, (1) Since the E-shaped cores 6 and 7 are difficult to deform, a very large force is required to change the gap length g.

(2) If too much force is applied, the gap length will decrease rapidly, making fine adjustment difficult.

(3) High-speed automatic adjustment is extremely difficult because the gap length, which has been reduced by tapping, returns to its original value once the external force is removed due to the spring back caused by the elasticity of the material. If you dare to do this, the rate of maladjustment will be extremely high.

(4) It is extremely difficult to restore something that has been hit too hard once, so it is basically a method that is difficult to modify.

(5) Adjustment cannot be made after the case is installed. That is,
If, for example, mechanical processing such as case tightening is performed after impedance adjustment, the adjusted lengths of the gaps 8 and 9 will be distorted, and the impedance will be deformed. Furthermore, when the case is made of a magnetic material such as an iron plate, even if the adjusted air gap does not change at all, leakage magnetic flux flows through a part of the case when the case is attached, causing a change in impedance.

On the other hand, a second conventional example is shown in FIGS. 2 to 4. That is, an electromagnetic device of which this discharge lamp ballast is an example has a T-shaped iron core 10 on one side of the assembled iron core.
The primary coil 13 and secondary coil 14 wound around the coil bobbins 11 and 12 are passed through the legs of the assembly, and these are surrounded by the other L-shaped cores 15 and 16 of the assembled core to form an outer iron type. U-shaped non-magnetic materials 17 and 18 are placed in the gaps 13' and 14' between the secondary coil 14 and the secondary coil 14.
The leaky cores 19 and 20 held in the housing are press-fitted, the entire body is covered and held by a case 21, and further impregnated with varnish for insulation treatment. 22 is a terminal.

The impedance of the electromagnetic device is adjusted by adjusting the amount by which the leaky cores 19 and 20 are inserted into the gaps 13' and 14'. In other words, the magnetic resistance R of this electromagnetic device is: R=(1/S)×{i/μ)+(g/μ ₀ )} ≒g/S μ ₀ However, μ and μ ₀ are the iron core and non-magnetic material. The magnetic permeability (μ>>μ ₀ ), i is the core magnetic path length and g is the air gap length are kept almost constant by the non-magnetic materials 17 and 18.

Therefore, when the amount of insertion of the leaky cores 19 and 20 is adjusted, the effective cross-sectional area S through which the magnetic flux passes changes, and therefore the magnetic resistance R changes, making it possible to adjust the impedance.

In this way, according to this electromagnetic device, since the impedance is adjusted depending on the amount of insertion of the leaky cores 19 and 20, problems (1) to (4) of the first conventional example are solved.

However, this electromagnetic device had the following drawbacks. That is, (1) Non-magnetic materials 17 and 18, which are holding members for holding the leaky cores 19 and 20, are required, and the workability of assembling the leaky cores 19 and 20 is poor. That is, due to the complicated process of sandwiching and press-fitting a plurality of leaky cores 19, 20 between U-shaped non-magnetic materials 17, 18, the workability is poor when done manually, and automation is also difficult.

(2) Not only does the leakage magnetic flux distribution change when the case is installed, but the state of the non-magnetic material part due to mechanical processing during case installation also changes, causing deviations in the adjusted impedance of the electromagnetic device, resulting in a high defect rate. Become.

(3) Even if an impedance error occurs after the case is tightened, it cannot be corrected.

On the other hand, in contrast to the conventional example, a groove 5 was formed on the gap side formed in the mating part, and a leaky core 6 was press-fitted therein (Utility Model Publication No. 36-016519). Since the leaky core is inserted closely on both sides, an appropriate gap cannot be created.
Therefore, desired impedance characteristics cannot be obtained. Furthermore, since the direction of the magnetic flux is in the thickness direction of the leaky core, there is a drawback that good characteristics cannot be obtained. In addition, there were some that formed holes in the magnetic path of the iron core and inserted magnetic insulators (for example,
No. 49-033345), the impedance could not be adjusted after the windings were inserted into the iron core, so the impedance could not be adjusted individually to the optimum condition, and furthermore, special materials were required.

Furthermore, when adjusting impedance, it is necessary to prepare multiple types of insulators and leaky cores in advance in order to change the amount of insulation and the length and width of the leaky core, and it is also necessary to change the types during adjustment. The workability was poor because of this.

[Purpose of invention]

The purpose of this invention is to provide an electromagnetic device that can easily obtain desired impedance characteristics without requiring special materials.

[Disclosure of invention]

The electromagnetic device of this invention has a thin plate-like leaky iron core,
The assembled iron core has a mating part in which a plurality of rectangular holes into which a plurality of pieces can be press-fitted are bored so that the plane of the leaky core is parallel to the magnetic flux, and a gap is formed in the mating part. Impedance was set by press-fitting the leaky core.

According to the configuration of this invention, the impedance is set by press-fitting the leaky core into the hole so that it is parallel to the magnetic flux, so the impedance can be set without the need for special members due to the air gap and the leaky core. Fine adjustment can be made by sequentially inserting leaky cores of the same shape. Therefore, desired impedance can be obtained easily and favorably.

Embodiment A first embodiment of this invention is shown in FIG. That is, this electromagnetic device includes a thin plate-shaped leaky core 29,
30, and mating parts 25, 26 in which rectangular holes 27, 28 into which a plurality of leaky cores 29, 30 can be press-fitted are bored so that the planes of the leaky cores 29, 30 are parallel to the magnetic flux. void 3
1 and 32, and holes 27 and 2.
The impedance is set by press-fitting the leaky cores 29 and 30 into 8.

This electromagnetic device uses a discharge lamp ballast as an example, and the assembled iron core is E-I-E type, that is, E type iron core 23, I
A set of a type core 1 and an E type core 24 is used as an example.

The impedance of this electromagnetic device is
The setting is such that if 8 is left as is, there will be a shortage. Therefore, the impedance can be finely adjusted by enlarging the magnetic path cross-sectional area S, which has become substantially smaller due to the presence of the holes 27 and 28, by press-fitting the leaky cores 29 and 30.

This configuration provides the following effects. That is, (a) since the impedance is set in advance by the holes 27 and 28, only a small number of leaky cores 29 and 30 are needed for fine adjustment of the impedance, which improves work efficiency. That is,
If the lengths of the gaps 31 and 32 are well controlled, one or two leaky cores 29 and 30 can be used for sufficient adjustment.

(b) A holding member for holding the leaky cores 29 and 30 is not required, making it possible to reduce costs and improve workability. That is, since the gaps 31 and 32 are already present and the leaky cores 29 and 30 are held in the holes 27 and 28, the conventional U-shaped non-magnetic members 17 and 18 are not necessary. Note that it is also possible to provide the leaky cores 29 and 30 with a slight taper to facilitate press-fitting.

(c) Precise adjustment of impedance is possible;
Low-cost design becomes possible. That is, 1-2
Since fine adjustment is performed using the two leaky cores 29 and 30, highly accurate adjustment is possible, and variations in product impedance are extremely small compared to conventional products.

(d) Since the leaky cores 29 and 30 are press-fitted into the holes 27 and 28 so that their planes are parallel to the direction of magnetic flux, impedance can be improved.

As a result, not only are there fewer defective products, but
This eliminates the need for redundant design to account for variations, making economical design possible.

A second embodiment of this invention is shown in FIGS. 6 and 7. That is, this electromagnetic device is an embodiment of a discharge lamp ballast for two lamps, and has an I-type iron core 33.
One common primary coil 34 is wound around the center of the coil, and secondary coils 35 and 36 are wound on both sides of the common primary coil 34, and a leakage path section is formed between the primary coil 34 and the secondary coils 35 and 36. Outer cores 38 and 39 forming mating portions 37 are combined, holes 40 for impedance setting are formed in mating portions 37, and leakage cores 41 are press-fitted for fine adjustment.

This embodiment has the advantage that adjusting the impedance at one end of the primary coil 34 does not affect the impedance adjusted at the other end. In other words, when the configuration shown in Figure 1 is applied to a discharge lamp ballast for two lamps, the gap length can be adjusted by tapping the iron core, and the impedance at one end of the primary coil can be adjusted at the other end. The adjusted impedance will be affected, making it impossible to make appropriate adjustments.

In addition, a notch 43 for inserting a leaky core in the case 42 is provided.
Since the impedance can be adjusted by inserting the leaky core 41 after crimping the case 42, it is possible to prevent impedance changes due to the case 42 and deviations due to machining after adjustment.

[Effect of idea]

According to the electromagnetic device of this invention, the impedance is set by press-fitting the leaky core into the hole so that it is parallel to the magnetic flux, so the impedance can be set by the air gap and the leaky core without the need for special members. Further, fine adjustment can be made by sequentially inserting leaky cores of the same shape. For this reason,
This has the effect that a desired impedance can be obtained easily and satisfactorily.

[Brief explanation of the drawing]

Figure 1 is a perspective view of the first conventional example, and Figure 2 is a perspective view of the second conventional example.
3 is a plan view, FIG. 4 is a perspective view of the case installed, and FIG. 5 is a press-fitting of the leaky core of the first embodiment of this invention. FIG. 6 is a perspective view of the main part in the previous state, FIG. 6 is a perspective view of the main part in the state before the leaky core of the second embodiment is press-fitted, and FIG. 7 is an explanatory diagram of the state before the case is attached. 1, 33...I type core of assembled iron core, 23, 24...
...E-type core of assembled iron core, 25, 26, 37... Joint portion, 38, 39... Outer core of assembled iron core, 27,
28, 40... Hole, 29, 41... Leaky core, 3
1,32...Void.

Claims (1)

[Scope of utility model registration request] An assembled iron core having a thin plate-shaped leaky core and a mating part in which a plurality of rectangular holes are drilled into which a plurality of sheets can be press-fitted so that the plane of the leaky core is parallel to the magnetic flux, and a gap is formed in the joint part. and
An electromagnetic device in which impedance is set by press-fitting the leaky core into the hole.