JP5751840B2 - X-ray high voltage generator and X-ray CT apparatus - Google Patents

Description

  The present invention relates to an X-ray apparatus that performs X-ray fluoroscopy and a high-voltage generator that supplies power to an X-ray CT apparatus.

  In an X-ray high-voltage apparatus, a high-speed pulse tube is used for cine imaging for imaging blood flow in a blood vessel as a moving image, or for pulsed fluoroscopy for obtaining a high-quality real-time image when operating a catheter in a blood vessel. A voltage is required. In order to control the tube voltage at high speed, the AC high voltage output is rectified by a high voltage rectifier and smoothed by a floating capacitance such as a capacitor or a high voltage cable connected in parallel to the X-ray tube to convert the DC high voltage to X A circuit configuration applied to the tube is used. The charge stored in the capacitor or the like cannot flow to the power supply side because of the high voltage rectifier, and the charge is discharged via the X-ray tube. Therefore, when the tube voltage is turned off, X-rays that are not used for imaging are emitted from the X-ray tube, and there is a problem that an invalid exposure occurs for the subject. In an imaging method that supplies a high-speed pulsed tube voltage, invalid exposure due to charge discharge occurs every time the tube voltage pulse falls (hereinafter referred to as a wave tail).

  Therefore, Patent Document 1 discloses a configuration in which a circuit (wave tail cut-off circuit) for discharging electric charges stored in a capacitor or the like is connected in parallel with the X-ray tube. The wave tail cutoff circuit includes an impedance for discharging electric charges and a switch for connecting the impedance to the X-ray tube at the timing of the wave tail. The switch is formed by connecting a large number of semiconductor switches in series in order to withstand a high voltage charged in the capacitor. Patent Document 1 proposes a high-voltage switch in which several semiconductor switches are mounted on a large number of substrates, and the substrates are electrically connected to each other while being stacked at intervals.

  Patent Document 2 discloses a configuration in which the wave tail cutoff circuit is arranged in a tank filled with insulating oil together with other circuits of the X-ray high voltage apparatus. A large number of substrates on which the switches of the wave tail cut-off circuit are mounted are accommodated in a frame-shaped fixture and stacked in multiple stages in a tank. This saves space for the entire high voltage generator including the wave tail cutoff circuit. Since the electric insulating oil is heated by the heat generated during the discharge of the wave tail cutoff circuit, the heat radiating fins are arranged outside the tank.

JP 2001-284097 A JP 2008-098072 A

  As described in Patent Document 2, in the high voltage generator using the electrical insulating oil, the electrical insulating oil expands as the temperature rises in the wave tail cutoff circuit or the like. When the temperature rise cannot be suppressed by natural air cooling or forced air cooling by the heat radiating fins, the internal pressure of the tank of the high voltage generator rises, causing a problem that the container is deformed or the electric insulating oil leaks. Therefore, in order to cope with the expansion of the electrical insulating oil, it is conceivable to use a method in which a space is provided in the tank in advance by the expansion volume and a tank having an expandable / contractible bellows structure (bellows). In the former, the entire tank needs to be formed large, and in the latter, it is necessary to secure an expandable space of the bellows structure outside the tank.

  An X-ray apparatus, an X-ray CT apparatus, and the like that perform X-ray fluoroscopic imaging have a limited mounting space for a high-voltage generator, and are required to be downsized. For this reason, it is difficult to arrange a large-scale cooling facility. Further, since the high voltage generator of the mobile X-ray apparatus or the X-ray CT apparatus is disposed near the subject or the operator, it is not desirable that the temperature becomes high.

  An object of the present invention is to provide a high-voltage generator that can save space and prevent invalid exposure of a subject.

In order to achieve the above object, according to the first aspect of the present invention, the following X-ray high voltage generator is provided. That is, a tube voltage generation circuit that generates a tube voltage to be supplied to an X-ray tube, a wave tail cutoff circuit that discharges charges in the tube voltage generation circuit when the tube voltage is lowered, a tube voltage generation circuit, and a wave tail An X-ray high voltage generator having a housing for accommodating a cutoff circuit and an electrical insulating oil filled in the container, wherein an elastic container having an internal space communicating with the space in the housing is provided on one surface of the housing. It is connected. The elastic container is equipped with a heat dissipation unit.

  It is also possible to employ a configuration further including a detection unit that detects that the stretchable container has been extended by a predetermined amount. When the detection unit detects that the stretchable container has expanded by a predetermined amount, the control unit can stop the discharge of the wave tail cutoff circuit. Alternatively, the control unit can cause the tube voltage generation circuit to stop generating the pulsed tube voltage and also stop the discharge of the wave tail cutoff circuit. Alternatively, the control unit can stop discharge of the wave tail cutoff circuit and inform the operator that a predetermined imaging method using a pulsed tube voltage cannot be accepted.

  As said detection part, a switch can be arrange | positioned in the position pushed up by a part of elastic container or the said thermal radiation unit. In this case, a part of the elastic container or the heat dissipation unit can be provided with a protrusion for pushing up the switch.

  Moreover, it is also possible to arrange | position a guide member along the direction which an elastic container expands / contracts.

  As the heat radiating unit, it is possible to use a unit including a bottom plate and a plurality of fins mounted side by side on the bottom plate at a predetermined interval. Fix it to the elastic container so that it touches the electrical insulating oil.

Moreover, according to the 2nd aspect of this invention, the following X-ray high voltage generators are provided. That is, a tube voltage generation circuit that generates a tube voltage to be supplied to an X-ray tube, a wave tail cutoff circuit that discharges charges in the tube voltage generation circuit when the tube voltage is lowered, a tube voltage generation circuit, and a wave tail An X-ray high voltage generator having a housing for accommodating a cutoff circuit and an electrical insulating oil filled in the container, wherein an elastic container having an internal space communicating with the space in the housing is provided on one surface of the housing. It is connected. The stretchable container has a metal bellows portion, and the bellows portion also serves as a heat dissipation unit.

Moreover, according to the 3rd aspect of this invention, the following X-ray CT apparatuses are provided. That is, an X-ray CT apparatus having a rotating disk for rotating around a subject and an X-ray tube and a high-voltage generator mounted on the rotating disk, the high-voltage generator being an X-ray tube A tube voltage generation circuit that generates a tube voltage to be supplied to the tube, a wave tail cutoff circuit that discharges charges in the tube voltage generation circuit when the tube voltage is lowered, and a tube voltage generation circuit and a wave tail cutoff circuit are accommodated It includes a housing and an electrical insulating oil filled in the container. A stretchable container having an internal space communicating with a space in the housing is connected to one surface of the housing. The elastic container is equipped with a heat dissipation unit.

  It is desirable that the stretchable container of the high voltage generator is mounted on the rotating disk so that the stretching direction is in a direction perpendicular to the centrifugal force direction of the rotating disk.

  The heat dissipation unit may have a plurality of fins arranged in an array. In this case, it is desirable that the main plane direction of the fin is arranged along the tangential direction of rotation of the rotating disk.

  The expansion / contraction direction of the elastic container can be configured to be directed in a direction orthogonal to the circumferential direction of the rotating disk.

  According to the present invention, it is possible to provide an X-ray high-voltage generator that can save space, can efficiently cool a temperature rise due to a wave tail cut-off circuit or the like, and can prevent invalid exposure of a subject. .

The block diagram which shows the whole circuit of the power supply using the high voltage generator of 1st Embodiment. The circuit diagram of the high voltage generator of FIG. The notch perspective view of the high-voltage generator of 1st Embodiment. Explanatory drawing which shows the mounting state of the wave tail interruption | blocking circuit of the high voltage generator of FIG. Explanatory drawing which shows the connection direction of the board | substrate of the wave-tail cutoff circuit of FIG. The perspective view of the high voltage generator of 1st Embodiment. The perspective view of the high voltage generator of 2nd Embodiment. The perspective view of the high voltage generator of 3rd Embodiment. The front view of the rotary disk of the X-ray CT apparatus of 4th Embodiment. The perspective view of the rotary disk of the X-ray CT apparatus of 4th Embodiment. The perspective view of the high voltage generator of 4th Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 shows an overall configuration diagram of a power supply device 100 of an X-ray imaging apparatus according to the present invention. The power supply apparatus 100 includes a DC power supply unit 110 that generates a DC voltage from a commercial power supply 105, an inverter circuit 120 that converts a DC voltage output from the DC power supply unit 110 into a high-frequency AC voltage, and boosts the AC voltage output from the inverter circuit 120. A high voltage generator 1 that generates a tube voltage by rectification and smoothing, and a control unit 160 are provided. The high voltage generator 1 is connected to the X-ray tube 7 and supplies a tube voltage to the X-ray tube 7. The control unit 160 is connected to the control circuit 300 of the console of the X-ray imaging apparatus.

  A circuit configuration of the high voltage generator 1 is shown in FIG. 2, and a cutaway perspective view of the appearance is shown in FIG. As shown in FIG. 2, the high voltage generator 1 converts the high voltage transformer 2 and the heating transformer 3 connected to the inverter circuit 120 and the high frequency voltage boosted by the high voltage transformer 2 into direct current. High voltage rectifier circuits 4a and 4b, a wave tail cutoff circuit 50, a smoothing capacitor 51, and connection terminals 9a and 9b are provided. The connection terminal 9 a is connected to the anode of the X-ray tube 7, and the connection terminal 9 b is connected to the cathode of the X-ray tube 7. The smoothing capacitor 51 is connected to the X-ray tube 7 in parallel.

  High voltage transformer 2 includes a primary winding 2a connected to inverter circuit 120, and a secondary winding 2b connected to high voltage rectifier circuit 4a. The heating transformer 3 includes a primary winding 3a connected to the inverter circuit 120 and a secondary winding 3b connected to the connection terminal 9b.

  The wave tail cut-off circuit 50 is a circuit in which high voltage discharge circuits 5a and 5b for discharging electric charges and switching circuits 6a and 6b are connected in series, such as an RC circuit. In FIG. 2, the switching circuits 6a and 6b are omitted as one switch circuit, but in practice, in order to cope with a high voltage, several tens to several hundreds of semiconductor switching elements are connected in series. It is a connected configuration. The wave tail cutoff circuit 50 is connected between the high voltage rectifier circuits 4 a and 4 b and the heating transformer 3 so as to be in parallel with the X-ray tube 7. The total load resistance of the high voltage discharge circuits 5 a and 5 b and the switching circuits 6 a and 6 b is designed to be smaller than the load resistance of the X-ray tube 7.

  The switching circuits 6a and 6b are switched on in synchronization with the fall of the tube voltage by the control signal of the controller 160. As a result, the charge stored in the smoothing capacitor 51 and the stray capacitance of the high voltage cable flows through the wave tail cut-off circuit 50 and is discharged in the high voltage discharge circuits 5a and 5b. Therefore, it is possible to prevent the X-ray from being radiated from the X-ray tube 7 after the fall of the tube voltage and causing an invalid exposure. Further, the charge flow instantaneously switches to the wave-tail cutoff circuit 50 having a time constant shorter than the load resistance of the X-ray tube 7, so that the fall of the tube voltage can be accelerated. Therefore, by using the power supply device of the present embodiment, pulse fluoroscopic imaging using a high-speed tube voltage with a short wave tail can be performed.

  As shown in FIG. 3, the high voltage transformer 2, the heating transformer 3, the high voltage rectifier circuit (cathode side) 4a, the high voltage rectifier circuit (anode side) 4b, the high voltage discharge circuit (cathode side) 5a, the high voltage discharge The circuit (anode side) 5 b, the high voltage switch circuit (cathode side) 6 a, and the high voltage switch circuit (anode side) 6 b are accommodated in the high voltage tank 8. The internal space of the tank 8 is filled with electrical insulating oil. The circuits accommodated in the tank 8 are insulated from each other by being filled with electrical insulating oil.

  As described above, the high voltage switch circuits 5a and 5b are obtained by connecting several tens to several hundreds of semiconductor switching elements in series. The semiconductor switching elements are mounted on several tens of switch boards 6c at intervals of several. As shown in FIG. 4, several tens of switching boards 6 c are accommodated in a frame-shaped fixture 10. By connecting the plurality of fixtures 10 so as to be stacked, the plurality of switching boards 6c are stacked with a predetermined interval (insulation distance 11) as shown in FIG. Is secured. Further, the adjacent switching substrates 6c are connected by the connection line 13 as shown in FIG. 5, and the semiconductor switching elements on all the switching substrates 6c are connected in series. The connection between the substrates 6c by the connection lines 13 is made so that the connection lines do not cross each other by rotating the substrates alternately up and down by 180 °. Since the connection method is a well-known technique described in Patent Documents 1 and 2, etc., detailed description is omitted here.

  Further, the fixture 10 is provided with three partition plates 10a, and the high voltage discharge circuits 5a and 5b are accommodated in a space 12 generated between the partition plates 10a when the fixtures 10 are stacked.

  By storing the wave tail cutoff circuit 50 in the storage fixture 10 in this way, it is not necessary to separately mount a circuit, and the number of work steps can be reduced.

  4 and 5, the switching substrate 6c on which the semiconductor switching element is mounted and the high voltage discharge circuits 5a and 5b are schematically illustrated in a rectangular parallelepiped shape. The semiconductor switching element is mounted so as to be exposed, and the high voltage discharge circuits 5a and 5b are configured to expose the resistance lines.

  In the high voltage tank 8, as shown in FIG. 3, a wave tail cut-off circuit accommodated in the fixture 10 is arranged at the lowest stage, and a high voltage rectifier circuit (cathode side) 4a and a high voltage rectifier circuit are arranged on the front side of the middle stage. (Anode side) 4b is arranged side by side. A high voltage transformer 2 is arranged on the back side of the middle stage. A connection terminal (cathode side) 9a and a connection terminal (anode side) 9b are arranged side by side in the upper stage, and a heating transformer 3 is arranged in the upper stage rear side. In this way, electrical components close to the ground potential such as the primary winding of the high voltage transformer 2 are arranged on the back side, and components having a high potential are arranged toward the front side.

  For the high-voltage switch circuits 5a and 5b, the innermost side of the stacked substrates is connected as a ground potential, and the frontmost side is the high-potential portion of the anode or cathode, so that the connection terminals 9a and 9b and the high-voltage rectifier circuit 4a are connected. 4b, respectively. As a result, the equipotential portions of the upper and middle high voltage generation circuits and the lower wave tail cutoff circuit 50 are arranged adjacent to each other, so that it is not necessary to add an insulating component.

  The entire internal space of the high voltage tank 8 is filled with electrical insulating oil. Thereby, the circuits arranged in the tank 8 are insulated from each other and the circuits are cooled.

  The circuit that is arranged in the high voltage tank 8 and generates the most heat during operation is the high voltage transformer 2 in which iron loss and copper loss occur during X-ray explosion, and the high discharge that occurs at the end of X-ray explosion. Examples include voltage discharge circuits 5a and 5b. The fixture 10 in which the high voltage discharge circuits 5a and 5b are accommodated has a structure in which the electric insulating oil is easily convected even when the high voltage discharge circuits 5a and 5b are accommodated. Thereby, the high voltage discharge circuits 5a and 5b can be efficiently cooled by natural convection of the electrical insulating oil. The high voltage transformer 2 is also surrounded by electrical insulating oil, so that it can be efficiently cooled.

  One side surface of the high voltage tank 8 is provided with a rectangular opening, and one end of a cylindrical bellows 15 having a rectangular opening shape is fixed as shown in FIG. A heat sink 14 is fixed to the other end of the bellows 15 so as to close the opening. The heat sink 14 includes a bottom plate 14a that closes the end of the bellows 15, and a plurality of fins 14b that are erected on the bottom plate 14a with a predetermined interval. The connecting portion between the bellows 15 and the tank 8 and the connecting portion between the bellows 15 and the heat sink 14 are kept sealed so that the electric insulating oil does not leak.

  The bellows 15 is made of, for example, an oil-resistant rubber or a metal with good heat dissipation such as aluminum.

  On the side surface of the high-pressure tank 8, a guide 18 is erected in the vicinity of the corner of the bellows 15, and guides the expansion and contraction of the bellows 15.

  A micro switch 16 is fixed to the guide 18 at a predetermined position. A protrusion 17 for pushing up the microswitch 16 along the guide 18 is attached to the side surface of the fin 14 b of the heat sink 14.

  When the temperature of the electrical insulating oil rises due to the heat generated by the circuit in the high voltage tank 8, the electrical insulating oil expands according to the thermal expansion coefficient. The expanded electrical insulating oil enters the inner space of the bellows 15 through the opening on the side surface of the tank 8 and pushes the bellows 15 along the guide 18. As described above, the bellows 15 expands in accordance with the expansion of the electrical insulating oil, so that the volume change of the electrical insulating oil can be absorbed and the pressure applied to the tank 8 can be prevented.

  Since the bottom plate 14a of the heat sink 14 is attached to the end opening of the bellows 15, the heat of the electrical insulating oil is conducted from the bottom plate 14a to the fins 14b and is radiated from the fins 14b to the surrounding atmosphere. . Therefore, the heat of the electric insulating oil can be efficiently radiated from the heat sink 14 at the tip of the bellows to the atmosphere, and the electric insulating oil is cooled.

  Further, since the heat sink 14 is mounted on the bellows 15, both the bellows 15 and the heat sink 14 can be installed on one surface of the high voltage tank 8. Therefore, it is only necessary to prepare a space beside one surface of the high voltage tank 8, and the space required for the surroundings is small and compact compared to a configuration in which the bellows 15 and the heat sink 14 are disposed on separate side surfaces. The high voltage generator 1 can be provided.

  Further, by arranging the guide 18 as shown in FIG. 6, even if the bellows 15 is arranged on the side surface of the tank 8, it is possible to prevent the bellows 18 from being tilted by the weight of the electric insulating oil in the bellows 15. Can do.

  Further, the temperature of the electrical insulating oil at that time can be obtained from the volume of the electrical insulating oil when expanded. In this embodiment, the volume of the electrical insulating oil corresponding to a predetermined allowable maximum temperature of the electrical insulating oil and the amount of elongation of the bellows 15 corresponding to the volume are obtained in advance, and when the amount of elongation is reached, the protrusion 17 is microscopic. The protrusion 17 and the micro switch 16 are attached to a position where the lever of the switch 16 is pushed up.

  The output signal of the micro switch 16 is transferred to the control unit 160. When the control unit 160 receives the micro switch 16, the control unit 160 performs a predetermined operation on the assumption that the temperature of the electrical insulating oil has reached the allowable maximum temperature.

  That is, the controller 160 can stop the operation of the wave tail cut-off circuit 50 in order to prevent further increase in the temperature of the electrical insulating oil. Specifically, the control unit 160 turns off the switching circuits 6a and 6b for a predetermined time. While the wave tail cut-off circuit 50 is turned off, in order to prevent invalid exposure, high-speed pulsed tube voltage is required. Control is performed so as not to perform pulse fluoroscopy or the like for obtaining a high-quality real-time image when operating. For example, the control unit 160 controls the inverter 120 not to output a high-speed pulsed tube voltage. The control unit 160 also outputs a signal notifying the control circuit 300 of the console of the X-ray imaging apparatus that an imaging method that requires a high-speed pulse tube voltage cannot be accepted. The console displays the fact on the display device to notify the operator, and restricts acceptable imaging methods.

  As described above, according to the first embodiment, it is possible to prevent a temperature increase above the allowable temperature of the high voltage generator including the wave-tail cutoff circuit with large heat dissipation and to provide a compact device. it can. Moreover, the malfunction that the deformation | transformation of the tank 8 or an electrical insulating oil leaks can be prevented.

  This high-voltage generator is useful for X-ray imaging devices, particularly for devices that are small and difficult to secure power supply cooling facilities, such as mobile X-ray imaging devices.

  In this high voltage generator, the microswitch 16 is arranged on the guide 18 and the protrusion 17 is arranged on the fin 14b. However, the present invention is not limited to these arrangements, and any position can be used as long as the microswitch 16 is turned on by the extension of the bellows 15. Such an arrangement may be adopted.

(Second Embodiment)
FIG. 7 shows a perspective view of the high voltage generator according to the second embodiment of the present invention.

  In the high voltage generator of FIG. 7, the bellows 15 is installed such that the expansion / contraction direction is parallel to the side surface. An opening (oil passage port) 19 is provided at the lower side of the tank 8, and a container 20 is fixed so as to communicate with the opening 19. The lower end of the bellows 15 is connected to the upper opening of the container 20. The upper end opening of the bellows 15 is closed by a heat sink 14.

  In the configuration of the first embodiment, it is necessary to prepare a space corresponding to expansion and contraction in the direction in which the bellows 15 extends due to the increase in the amount of electrical insulating oil (direction perpendicular to the side surface). Then, since the bellows 15 expands and contracts in a direction parallel to the side surface, there is an advantage that the space required beside the side surface of the tank 8 does not change before and after the expansion and contraction. Therefore, the second embodiment can provide a high-voltage generator that saves more space than the first embodiment.

  Note that the structure of the tank 8 is the same as that of the first embodiment, and a description thereof will be omitted.

  In the device structure of the second embodiment, since the heat radiation area of the heat sink 14 is smaller than that of the first embodiment, the bellows 15 is made of a metal with good heat dissipation, and the bellows 15 is also positive. It is desirable to dissipate heat and improve heat dissipation efficiency.

  Also in this embodiment, as shown in FIG. 7, by fixing the microswitch 16 at a predetermined position on the side surface of the tank 8, the microswitch 16 can be pushed up by the heat sink 14 and the temperature of the electrical insulating oil can be detected. .

  Although not shown in FIG. 7, it is of course possible to provide a guide on the container 20 along the expansion / contraction direction of the bellows 15.

(Third embodiment)
FIG. 8 shows a perspective view of a high voltage generator according to a third embodiment of the present invention.

  In the high voltage generator, a plurality of small cylindrical bellows 21 are arranged and fixed to the side surface of the tank 8. The electric insulating oil enters the inside of the small cylindrical bellows 21 and each cylindrical bellows 21 expands and contracts to absorb the expansion of the electric insulating oil, thereby preventing the tank 8 from being pressurized.

  The plurality of cylindrical bellows 21 is preferably made of a metal with high heat dissipation. The plurality of cylindrical bellows 21 are in a contracted state when the temperature of the electrical insulating oil is low. However, the cylindrical bellows 21 are expanded and the surface area is increased when the temperature is high, so that the heat of the electrical insulating oil can be efficiently radiated. That is, the cylindrical bellows 21 also serves as a heat sink.

  In the configuration of FIG. 8, if the longest length of the cylindrical bellows 21 is determined, it is not necessary to secure more space in the direction perpendicular to the side surface.

  Since the surface area of the cylindrical bellows 21 depends on the cooling efficiency, the shape is not limited to the shape shown in FIG. 8, but the shape is complicated while maintaining the stretchable structure, or the number of the cylindrical bellows 21 is increased. Further, it is possible to further improve the cooling efficiency.

(Fourth embodiment)
As a fourth embodiment, an example of an X-ray CT apparatus equipped with the high voltage generator of the present invention will be described.

  FIG. 9 is a front view of a rotating disk 91 that rotates around the subject of the X-ray CT apparatus, and FIG. 10 is a perspective view of the rotating disk 91. At least the X-ray tube 7, the high voltage generator 1, and the X-ray detector 92 are mounted on the rotating disk 91. When a tube voltage is supplied from the high voltage generator 1 to the X-ray tube 7 while rotating the rotating disk 91 around the subject, X-rays are emitted from the X-ray tube 7 to the subject. By detecting X-rays transmitted through the subject with the X-ray detector 92, a tomographic image of the subject can be taken.

  As shown in the perspective view of FIG. 11, the high voltage generator 1 has a configuration in which a guide 18 for guiding expansion and contraction of the bellows 15 is provided in the device of FIG. 7 of the second embodiment. Centrifugal force (rotational acceleration) is applied to the high voltage generator 1 as the rotating disk 91 rotates at a high speed. Therefore, in the present embodiment, as shown in FIGS. 9 to 11, the extension direction of the bellows 15 is orthogonal to the centrifugal force, and the main plane of the fin 14 b of the heat sink 14 is high so as to be along the tangential direction of the rotating disk 91. The voltage generator 1 is mounted on the rotating disk 91.

  Thereby, the extension of the bellows 15 is not hindered by the centrifugal force and the acceleration at the start and stop of rotation. Moreover, since air passes between the fins 14b as the rotating disk 91 rotates, the fins 14b can be efficiently cooled, and the cooling efficiency of the electrical insulating oil can be increased.

  Further, since the guide 18 prevents the bellows 15 from being inclined, the bellows 15 can be expanded and contracted in parallel with the side surface of the tank 8 according to the expansion of the electrical insulating oil.

  Since it can be detected from the volume of the bellows 15 that the electric insulating oil has reached the allowable maximum temperature by the output of the microswitch 16, the wave tail cutoff circuit can be stopped as in the second embodiment.

  The high voltage generator that can be mounted on the X-ray CT apparatus is not limited to the apparatus of the second embodiment, and the high voltage generator of the first and third embodiments can also be mounted. is there. Also in this case, it is desirable that the extending direction of the bellows 15 is orthogonal to the centrifugal force. It is desirable that the fin 14 b of the heat sink 14 be mounted on the rotary disk 91 so that the main plane is along the tangential direction of the rotary disk 91. It is further desirable that the direction of acceleration at the time of starting and stopping the rotation of the rotating disk 91 is orthogonal to the extending direction of the bellows 15.

  In the present invention, the shape of the fins 14b, the shape of the bellows 15, and the attachment position of the bellows 15 are not limited to the shapes and positions shown in the embodiments described above. It is possible to change the shape and position in consideration of heat dissipation efficiency.

1: high voltage generator, 2: high voltage transformer circuit, 3: heating transformer, 4a, 4b: high voltage rectifier circuit, 5a, 5b: high voltage discharge circuit, 6a, 6b high voltage switch circuit, 7: X Wire tube, 8: High voltage tank, 9a, 9b: Connection terminal, 10: Fixing tool, 11: Insulation distance, 12: Space, 13: Connection line, 14a: Bottom plate, 14b: Fin, 14: Heat sink, 15: Bellows, 16: Microswitch, 17: Protrusion, 18: Guide, 19: Oil passage port (opening), 20: Container, 21: Cylindrical bellows, 50: Wave tail cutoff circuit, 51: Smoothing capacitor, 91: Rotation Disc, 92: X-ray detector, 100: Power supply device, 110: DC power supply, 120: Inverter circuit, 160: Control unit, 300: Control circuit of console

Claims (11)

A tube voltage generating circuit for generating a tube voltage to be supplied to the X-ray tube, a wave tail cutoff circuit for discharging charges in the tube voltage generating circuit when the tube voltage is lowered, the tube voltage generating circuit, and the A housing for housing the wave tail cutoff circuit, and an electrical insulating oil filled in the container,
One surface of the housing is connected to a stretchable container having an internal space communicating with the space in the housing, and the heat dissipation unit is mounted on the stretchable container ,
An X-ray high voltage generator, wherein a guide member is disposed along a direction in which the elastic container expands and contracts .   2. The X-ray high voltage generator according to claim 1, further comprising a detection unit that detects that the stretchable container has expanded a predetermined amount.   The X-ray high voltage generator according to claim 2, further comprising a control unit that stops discharge of the wave tail cut-off circuit when the detection unit detects that the stretchable container has expanded a predetermined amount. An X-ray high voltage generator characterized by the above.   3. The X-ray high voltage generator according to claim 2, wherein when the detection unit detects that the stretchable container has expanded a predetermined amount, the tube voltage generation circuit stops generation of a pulsed tube voltage. In addition, the X-ray high voltage generator further includes a control unit for stopping the discharge of the wave tail cutoff circuit.   3. The X-ray high voltage generator according to claim 2, wherein when the detection unit detects that the stretchable container has expanded a predetermined amount, the discharge of the wave tail cutoff circuit is stopped and a pulse is sent to the operator. An X-ray high voltage generator, further comprising a control unit for notifying that a predetermined imaging method using a tube voltage cannot be accepted.   The X-ray high voltage generator according to claim 2, wherein the detection unit is a switch provided at a position pushed up by a part of the stretchable container or the heat dissipation unit. Generator.   7. The X-ray high voltage generator according to claim 6, wherein a projection for pushing up the switch is provided on a part of the stretchable container or the heat radiating unit. apparatus. The X-ray high voltage generator according to claim 1, wherein the heat dissipation unit includes a bottom plate and a plurality of fins mounted side by side with a predetermined interval on the bottom plate,
The X-ray high-voltage generator according to claim 1, wherein the back surface of the bottom plate is fixed to the stretchable container so that the back surface is in contact with the electrical insulating oil in the stretchable container. An X-ray CT apparatus having a rotating disk for rotating around a subject, and an X-ray tube and a high voltage generator mounted on the rotating disk,
The high-voltage generator includes a tube voltage generation circuit that generates a tube voltage to be supplied to an X-ray tube, a wave tail cutoff circuit that discharges charges in the tube voltage generation circuit when the tube voltage is lowered, A housing that houses the tube voltage generation circuit and the wave tail cut-off circuit, and an electrical insulating oil filled in the container,
One surface of the housing is connected to a stretchable container having an internal space communicating with the space in the housing, and the heat dissipation unit is mounted on the stretchable container ,
The X-ray CT apparatus , wherein the stretchable container of the high-voltage generator is mounted on the rotating disk with a stretching direction oriented in a direction perpendicular to the direction of centrifugal force of the rotating disk . 10. The X-ray CT apparatus according to claim 9 , wherein the heat dissipation unit has a plurality of fins arranged in an array, and a main plane direction of the fins is arranged along a tangential direction of rotation of the rotating disk. X-ray CT apparatus characterized by being made. The X-ray CT apparatus according to claim 9 , wherein an expansion / contraction direction of the elastic container is directed in a direction orthogonal to a circumferential direction of the rotating disk.

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