JPH0648659B2 - High pressure generator - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a high-voltage generator suitable as a high-voltage generator such as an X-ray diagnostic apparatus.

[Technical Background of the Invention and Problems Thereof] In the conventional high voltage generator, both the primary coil and the secondary coil are laid out in one tank in order to rectify and output the secondary high voltage. . Then, a multi-cylindrical coil is used as the secondary coil, a plurality of taps are taken out from this secondary coil, and a high-speed diode group is interconnected between each tap to form a rectifier circuit. I'm trying to get the output.

However, in this conventional device, a high voltage of several KV is induced between both terminals of the secondary coil, so that the insulation level of the transformer is inevitably increased, and as a result, it becomes about 2/3 of the coil weight. Insulating materials with an incredible weight have become indispensable, leading to an increase in the size and weight of the entire device.

[Object of the Invention] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a high-voltage generating device that has a simplified insulating structure and can be made smaller and lighter as a whole. .

[Outline of the Invention] An outline of the present invention for achieving the above object is to provide a transformer including an air-core type primary side coil and a secondary side coil arranged on the outer circumference of the primary side coil, and a secondary side coil. In a high-voltage generator having a connected high-speed type diode group, a drum-shaped insulating bobbin superposed on the outer periphery of the primary side coil, and windings on the insulating bobbin, respectively, to pull out terminals of adjacent terminals. The secondary coil is arranged so as to be opposite to each other across the transformer.

[Examples of the Invention] Examples of the present invention will be described in detail below.

FIG. 1 shows a transformer T of a high voltage generator,
This transformer T is closely attached to both ends of the insulating cylinder 1 and the primary coil 2 wound around the outer circumference of the insulating cylinder 1 and having a coil length shorter than the length of the insulating cylinder 1. A pair of disc-shaped plates 3a and 3b, a rod 4 penetrating the central portion of the insulating cylinder 1 and both plates 3a and 3b and projecting outward from the plates 3a and 3b, respectively. 4 are screwed into the screw portions 4a and 4b formed on the outer circumferences of both ends of the plate 4, respectively.
Nuts 5a and 5b for closely fixing 3 and 3b to the insulating cylinder 1
And an annular coil support member 6a disposed between one end of the primary coil 2 and the inner surface of the plate 3a on the outer periphery of the insulating cylinder 1, and between the other end of the primary coil and the inner surface of the plate 3b. 6b and this coil support member 6a,
Bolts 7a and 7b for attaching 6b to the plates 3a and 3b, respectively, and an inner diameter larger than the outer diameters of the coil supporting members 6a and 6b and the primary coil 2;
A plurality of drum-shaped insulating bobbins 8 arranged in a superposed manner between both plates 3a and 3b, and a coil 9 wound around each insulating bobbin 8 are provided. The entire coil 9 constitutes a secondary coil 10 in a divided state.

As shown in FIGS. 2 and 3, the drum-shaped insulating bobbin 8 includes a lower plate 8a having a diameter substantially equal to that of the plates 3a and 3b, and an upper plate 8b having a diameter larger than the lower plate 8a. Are integrally connected by a cylindrical connecting tube 8c so that the overall shape is a drum shape.

The inner diameter of the connecting cylinder 8c is the same as the coil supporting member 6a.
, 6b and the outer diameter of the primary coil 2 are formed to be slightly larger.

A rib 8d is formed on the outer peripheral portion of the outer surface of the upper plate 8b,
When the insulating bobbins 8 are stacked, the lower plate 8a of the other insulating bobbin 8 is housed inside the rib 8d in a fitted state. Further, in FIG. 1, a part of the plate 3a is accommodated in the upper plate 8b of the uppermost insulating bobbin 8 in a fitted state.

The upper bob 8b of the insulating bobbin 8 is provided with a hole 11 close to the connecting cylinder 8c, and the outer surface of the upper plate 8b is provided with a V-shaped or arcuate groove 12 communicating with the hole 11. It is formed up to the outer peripheral edge.

As shown in FIG. 4, the winding start terminal 9a of the coil 9 wound around the insulating bobbin 8 is pulled out to the side of the insulating bobbin 8 through the hole 11 and the groove 12, and the winding end terminal 9b of the coil 9 is also wound. It is pulled out in the same direction as the starting terminal 9a.

As shown in FIG. 1, the winding start terminal 9a and the winding end terminal 9b of each coil 9 wound around each insulating bobbin 8 in this manner are the first, the third, and the third from the plate 3a side.
... are drawn out to one side of this transformer T, and the second, fourth, ... things are drawn out in the opposite direction.

In the transformer T having the above-described configuration, since each coil 9 that constitutes the secondary coil 10 is wound around the insulating bobbin 8, the interlayer insulating paper between the coils 9 is not necessary, and n coils 9 ( (n is a positive integer) In the case of superposition, the insulation structure between the coils 9 may endure E / n (KV), and the whole insulation structure can be reduced. Here, E (KV) is the secondary voltage induced in the secondary coil 10.

In addition, the transformer T can be made smaller and lighter by eliminating the need for the interlayer insulating paper and reducing the insulating structure.

Further, the secondary side voltage can be arbitrarily set by selecting the number of superposed coils 9 and insulating bobbins 8.

Furthermore, when assembling this transformer T, a secondary coil can be constructed by arranging the coils 9 respectively wound around a plurality of insulating bobbins 8 while overlapping them between the plates 3a and 3b. The coil drying and varnish treatment at the time of semi-finishing like the device of No. become unnecessary,
The coil forming can be simplified.

Next, a high voltage generator using the transformer T having the above configuration will be described.

FIG. 5 shows the circuit configuration of the high-voltage generator, in which 13 is an input DC power supply. This input DC power supply 1
The primary coil 2 of the transformer T is connected to the switch 3 via the switch element 14. This transformer T is provided with a secondary coil 10 wound in a divided manner, and boosts the AC power input to the primary coil 2 and outputs it.

A diode 16 is connected in antiparallel between both ends of the switch element 14, and a capacitor 17 is connected in parallel to the primary side coil 2 to form a so-called voltage resonance type single end switch circuit. A rectifying circuit 18 is formed in the secondary coil 10 of the transformer T by using a plurality of rectifying elements, for example, high-speed type diodes, and an X-ray tube 19 as a load is connected between output terminals thereof. It is supposed to be done.

The rectifier circuit 18 has two sets of diode groups, each of which has a predetermined number of diodes connected in series in one conduction direction, connected in parallel in the same polarity direction, and has both ends thereof as output terminals. Then, each coil 9 of the transformer T is bridged between the series connection points of the respective diode groups corresponding to each other, that is, so as to bridge the series connection points (these coils 9A in FIG. 9B, ..., 9n) are connected. The coils 9A, 9B, ..., 9n are connected in order between the series connection points by alternately changing the winding directions. As a result, the rectifier circuit 18 has a so-called ladder-like connection configuration. The coils 9A, 9
Differences in the winding directions of B, ..., 9n are indicated by ● in the figure. The following description will be given here, assuming that one end on the ● side is the winding start terminal 9a. In addition, as shown in FIG.
A ₁ , 18A _{2 to} 18A _{n + 1} , 18B ₁ , 18B ₂ to 1
8B _{n + 1} is attached.

In the high-voltage generator configured as described above, assuming that the switch element 14 is in a conductive state, the coils 9A, 9B, ..., 9n of the transformer T are connected to the winding start terminal 9a side indicated by a ● mark. A positive voltage is induced. At this time, the voltage of the input DC power supply 13 is maintained as it is. At this time, the voltages respectively induced in the coils 9A, 9B, ..., 9n are forward biased by the diode 1
8A _{n + 1} , 18B _{n to} 18B ₄ , 18A ₃ , 18B ₂ ,
The signals are added via 18A ₁ and applied to the X-ray tube 19.

Next, when the switch element 14 is turned off, the current energy stored in the leakage inductance and the exciting inductance of the transformer T flows into the capacitor 17. At this time, the power supply voltage Ein applied to the primary coil 2 draws an arc of resonance and drops, and eventually becomes a negative potential. Then, after the maximum value (at a negative potential) has passed, the voltage returns to the power supply voltage Ein again. In this way, during the period in which the power supply voltage applied from the capacitor 17 has a negative potential, a reverse polarity, that is, a negative potential is applied to the primary coil 2 of the transformer T. As a result, in each of the coils 9A, 9B, ..., 9n, a positive potential is induced on the winding end terminal 9b side on the side not marked with ●. These induced voltages are then forward biased by the diodes 18B _{n + 1} , 18An to 18A.
₄ , 18B ₃ , 18A ₂ and 18B ₁ are added and supplied to the X-ray tube 19. This power supply is performed with the same polarity as when the switch element 14 is conducting, and as a result, the voltage induced in the secondary coil 10 is applied to the X-ray tube 19 as if it had been subjected to double-wave rectification. Will be done.

That is, the switching circuit on the primary coil 2 side of the transformer T is an inverter using a voltage resonance waveform,
Each coil 9 of the primary side coil 2 and the secondary side coil 10 is used almost without utilizing the exciting inductance of the transformer T.
Leakage inductance between A, 9B, ..., 9n,
A rectified output is obtained using the resonance voltage waveform with the capacitor 17. Therefore, when the switching element 14 is conducting, the current from the input DC power supply 13 induces a voltage in the coils 9A, 9B, ..., 9n via the leakage inductance, and the diodes 18A ₁ , 18A _{2 to} 18A _{n + 1.} Will be supplied to the X-ray tube 19 through the following path. When the switching element 14 is cut off, the current stored in the leakage inductance passes through the coils 9A, 9B, ..., 9n and the diodes 18B ₁ , 18A _{2 to} 18B _{n + 1} and further passes through the X-ray tube 19. The capacitor 17 is charged. In other words, in the single-ended switch circuit having the above-described configuration that resonates mainly with the leakage inductance and the capacitor 17, the flyback pulse as well as the forward pulse can be used for power transmission, and its double-wave rectified output is possible here. Become.

As described above, according to the above device, the voltages induced in the coils 9A, 9B, ..., 9n of the secondary coil 10 of the transformer T can be effectively double-wave rectified and taken out. it can. Moreover, at this time, the number of diodes composing the rectifying circuit 18 is sufficient (2n + 2), where n is the number of coils 9A, 9B, ..., 9n. Therefore, about half the number of diodes is sufficient as compared with the conventional one in which a rectifying bridge is connected for each potential. Further, as described above, the high-voltage output can be extracted by double-wave rectification, so that the output voltage waveform is stable, and electric power can be efficiently and stably supplied to a special load such as an X-ray generator. Is possible.

Next, the secondary coil 10 in the transformer T and each diode 18A _{1 to} 18A _{n + 1} , 18B _{1 to} 18B.
The arrangement relationship of _{n + 1} will be described.

For example, as shown in FIG. 6 (a), the surface of the primary coil 2 is virtually divided into four planes (A plane, B plane, C plane, D plane), and the four planes are surrounded. As shown in FIG. 6 (b), two sets of diode connection wirings 20A and 20B are formed. The two sets of diode connection wirings 20A and 20B are bent and formed so as to have diode connection surfaces on the two surfaces (B surface and D surface) facing each other, and come down in a zigzag shape from top to bottom. The bending points are arranged adjacent to each other at the boundary between the B and C surfaces and the boundary between the A and D surfaces. Then, the diodes 18A ₁ to 18A _{n + 1} and 18 are arranged on the _respective surfaces so that they are turned upside down.
B _{1 to} 18B _{n + 1} are connected in series, and coils 9A, 9B, ..., 9n are connected to adjacent portions of the two sets of the diode connecting wirings 20A and 20B, respectively. That is, it is designed to isolate as much as possible the portion that needs to withstand voltage.

In the wiring system of FIG. 6 (b), the diodes 18A _1
1 as 18A _{n + 1} and 18B _{1 to} 18B _{n + 1} respectively
I explained the case of using each diode,
It is possible to connect the wires in the same manner even if each of them is plural.

Further, in the connection method of FIG. 6 (b), the case where the diodes are arranged on the B surface and the D surface has been described, but the diode can be arranged on the remaining A surface and the C surface.

Further, as shown in FIGS. 7 (a) and 7 (b), the spiral connection method and the step connection method can be used.

Needless to say, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the gist thereof.

[Effects of the Invention] According to the present invention described in detail above, the secondary coil of the transformer is configured by a coil group wound around a plurality of drum-shaped insulating bobbins, and the terminals of adjacent coils are led out.
Since the transformers are arranged so that they face each other in opposite directions, an interlayer insulator is not required, and the insulation structure can be reduced. Furthermore, the parts that need to withstand voltage should be isolated as much as possible, and the entire device should be isolated. It is possible to provide a high-voltage generating device that can be reduced in size and weight.

[Brief description of drawings]

1 is a partially cutaway sectional view showing the structure of a transformer in an embodiment of the device of the present invention, FIG. 2 is a plan view of an insulating bobbin constituting the transformer shown in FIG. 1, and FIG. 3 is a partially cutaway view of the same. Sectional view, FIG. 4 is a partially cutaway sectional view showing a state in which a coil is wound around an insulating bobbin, FIG. 5 is a circuit diagram of a high voltage generator using a transformer shown in FIG. 2, and FIG. 6 (a). Is an explanatory view showing a state in which the surface of the primary side coil is divided into four surfaces, and FIG. 6 (b) is a partially omitted perspective view showing a state in which the secondary side coil and the diode are connected corresponding to FIG. 7 (a) and 7 (b) are perspective views showing modifications of the diode wiring system, respectively. T ... Transformer, 2 ... Primary coil, 9A, 9B,
..., 9n ... coil, 10 ... secondary coil, 18A ₁
.About.18A _{n + 1} , 18B _{1 to} 18B _{n + 1} ... Diode.

Claims (1)

[Claims] 1. A high voltage generator having a transformer comprising an air-core type primary side coil and a secondary side coil arranged on the outer periphery of the primary side coil, and a high speed type diode group interconnected to the secondary side coil. In the device, a drum-shaped insulating bobbin superposed on the outer periphery of the primary side coil and wound around the insulating bobbin are arranged so that terminals of adjacent terminals are drawn in opposite directions with the transformer interposed therebetween. And a secondary coil, the high voltage generator.