JP2006073380A - X-ray source - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray source in which a circuit board can be fixed stably. <P>SOLUTION: The X-ray source 1 is equipped with an X-ray generating part that radiates X-rays, a circuit board holder 49 that supports circuit boards 35, 37 which control the X-ray generating part, and a cooling fan that makes the cooling wind flow around the circumference of the circuit board holder 49 in the inner part of the cabinet 3. The circuit board holder 49 is fixed on a bottom plate 3a, and has a first flat plate part 46 and a second flat plate part 48 which are mutually coupled while facing each other, and since they are in a V-shaped structure, a circuit board 35 mounted on the first flat plate part 46 and the circuit board 37 mounted on the second flat plate 48 are fixed stably to the bottom plate 3a. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention particularly relates to an X-ray source used as a microfocus X-ray source.

Conventionally, a microfocus X-ray source described in Patent Document 1 is known as a technique in such a field. This microfocus X-ray source is a type of X-ray source including an X-ray tube that collides electrons from an electron gun with a target and irradiates the generated X-rays to the outside through an irradiation window.
Japanese Patent No. 2634369

  This type of microfocus X-ray source is also used in a CT scanner that can obtain a non-destructive cross-sectional image of an object by transmitting X-rays through the object. In such a CT scanner, a method of irradiating an object with X-rays from various directions while moving the X-ray source circumferentially around the object is employed. As described above, when the X-ray source is used while being moved, the circuit board of the X-ray source is subjected to vibration, so that the circuit board may be broken by the vibration, and the life of the circuit board is shortened. It was pointed out that Therefore, in such an X-ray source, in order to reduce the vibration of the circuit board as much as possible, it is a problem to stably fix the circuit board.

  An object of this invention is to provide the X-ray source which can fix a circuit board stably.

  An X-ray source of the present invention includes an X-ray generator having an X-ray tube and irradiating X-rays to the outside, and a circuit board that is housed in a housing and supports a circuit board that controls the X-ray generator A holder and a cooling fan for allowing cooling air to flow around the circuit board holder inside the housing. The circuit board holder is fixed in the housing, and is opposed to each other and connected to each other. It has a flat plate portion and a second flat plate portion, and a circuit board is fixed to at least one of the first flat plate portion and the second flat plate portion.

  In this X-ray source, the circuit board is fixed to the flat plate portion of the circuit board holder in the housing. The circuit board holder is improved in mechanical strength by connecting the first flat plate portion and the second flat plate portion facing each other. And by fixing a circuit board to this circuit board holder, a circuit board is stably fixed in a housing | casing and it can suppress the disconnection and short life of a circuit board.

  Moreover, it is preferable that the edge part of the 1st flat plate part and the edge part of the 2nd flat plate part are mutually connected. By connecting the first and second flat plate portions at the end portions, high mechanical strength of the circuit board holder itself can be obtained.

  Moreover, it is preferable that the internal angle of a 1st flat plate part and a 2nd flat plate part is an acute angle. Due to such a positional relationship of the flat plate portions, the first flat plate portion and the second flat plate portion form a mountain-shaped circuit board holder, and the circuit board holder can obtain high mechanical strength in the housing. Further, since the circuit board can be tilted and housed in the housing, the housing can be miniaturized.

  In addition, the housing has a first wall having an irradiating unit that irradiates X-rays from the X-ray tube, and a second wall that extends in a direction substantially orthogonal to the first wall and is provided with a cooling fan. And an inclined wall that connects the first wall and the second wall and extends substantially in parallel to the first flat plate portion.

  In this X-ray source, a gap having a substantially constant width is formed between the first flat plate portion and the inclined wall, and the cooling air generated from the cooling fan flows in this gap. At this time, since the width of the gap is substantially constant, the cooling air can flow in the gap without stagnation, and the cooling air smoothly flows in the housing. Therefore, the circuit board fixed to the circuit board holder can be efficiently cooled, and the operation characteristics of the circuit board can be stabilized.

  In addition, the X-ray source of the present invention includes a drive power supply unit that supplies drive power to the X-ray generation unit, and the drive power supply unit is fixed to the circuit board holder and is positioned in the vicinity of the exhaust port provided in the housing. May be. In this case, the cooling air flowing around the drive power supply unit is quickly discharged to the outside through an exhaust port near the drive power supply unit after removing heat from the high-temperature drive power supply unit. For this reason, it is possible to efficiently cool the drive power supply unit, and it is possible to prevent the cooling air after cooling the drive power supply unit from flowing back into the housing and increasing the temperature of the circuit board.

  According to the present invention, the circuit board inside the X-ray source can be stably fixed.

  Hereinafter, preferred embodiments of an X-ray source according to the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is used for the same element and the overlapping description is abbreviate | omitted.

(First embodiment)
As shown in FIGS. 1 and 2, the X-ray source 1 is an X-ray type having an X-ray tube that causes electrons from an electron gun to collide with a target and irradiate the generated X-rays to the outside through an irradiation window. For example, it is used as an X-ray source in a CT scanner. An X-ray generation unit 5 that generates and emits X-rays and a control unit 7 that controls the X-ray generation unit 5 are stored inside the housing 3 of the X-ray source 1. The internal space of the housing 3 is composed of an X-ray generation unit accommodation space R1 that accommodates the X-ray generation unit 5 and a control unit accommodation space R2 that accommodates the control unit 7, and the X-ray generation unit accommodation space R1. A partition wall 15 extending downward from the upper inner wall of the housing 3 is provided between the control unit housing space R2.

  As shown in FIG. 3, the X-ray generation unit 5 includes a high-voltage power supply unit 17 fixed to the bottom plate 3 a of the housing 3, and an X-ray tube that receives X-rays upon receiving power from the high-voltage power supply unit 17. 27 and a metal tube (X-ray tube surrounding portion) 29 that surrounds a part of the X-ray tube 27. The high voltage power supply unit 17 includes a high voltage transformer 19 that can generate a high voltage, a high voltage supply circuit 23 that multiplies the high voltage generated by the high voltage transformer 19 and supplies the high voltage to the X-ray tube 27, and a high voltage transformer 19 and a high voltage supply. A connection line 25 a for connecting the circuit 23 and a connection line 25 b for connecting the high voltage supply circuit 23 and the X-ray tube 27 are provided. The high-voltage supply circuit 23 and the connection lines 25 a and 25 b are molded in an insulating block 21 made of an electrically insulating material (for example, epoxy resin), and the high-voltage transformer 19 is controlled by the side surface of the insulating block 21. Projecting to the part 7 side. Such a structure of the high-voltage power supply unit 17 prevents discharge from the high-voltage supply circuit 23 to which a high voltage is applied and the connection lines 25a and 25b to the outside.

  The X-ray tube 27 located above the high-voltage power supply unit 17 is of a reflective target type, and is provided at the end of the rod-shaped anode 27b and the valve portion 27a that holds and accommodates the rod-shaped anode 27b in an insulated state. A target accommodating portion 27d that accommodates the provided target 27c and an electron gun portion 27e that accommodates an electron gun 27k that emits an electron beam toward the reflecting surface of the target 27c are provided.

  The valve portion 27a and the target accommodating portion 27d are arranged coaxially, and the axis of the electron gun portion 27e is substantially orthogonal to the axis. The base end portion of the rod-shaped anode 27b protrudes downward from the lower portion of the valve portion 27a as the high voltage application portion 27g.

  A socket 33 is coupled to the lower portion of the high voltage application unit 27g, and the socket 33 is connected to the high voltage supply circuit 23 via the connection line 25b of the high voltage power supply unit 17. With such a configuration, a high voltage is supplied to the X-ray tube 27 from the high voltage supply circuit 23 through the connection line 25b. When the electron gun 27k in the electron gun unit 27e emits electrons toward the target 27c in a state where the X-ray tube 27 is supplied with a high voltage, X-rays are generated from the target 27c, and the X-rays are generated. Irradiation is performed from an X-ray irradiation window 27h provided in the opening of the target accommodating portion 27d.

  The X-ray tube 27 is a hermetically sealed type sealed in a vacuum. For example, the X-ray tube 27 is provided with an exhaust pipe (not shown), and after the inside of the valve portion 27a, the target accommodating portion 27d and the electron gun portion 27e is evacuated, the exhaust tube is sealed. Sealed by stopping.

  The metal tube 29 protrudes upward from the upper surface of the high-voltage power supply unit 17 and is formed in a cylindrical shape surrounding the X-ray tube 27. In order to efficiently dissipate heat generated from the X-ray tube 27, the metal tube 29 is made of a metal (for example, aluminum) having excellent heat dissipation and is provided with a plurality of cooling fins 29a extending in the horizontal direction around the metal tube 29. ing. The cooling fin 29a is provided as a convex strip extending in the circumferential direction on the peripheral surface of the metal tube 29, and increases the surface area of the metal tube 29, and efficiently dissipates heat generated from the X-ray tube 27. Can do.

  An opening 29j is formed in the tip surface of the metal tube 29, and a valve portion 27a of the X-ray tube 27 is inserted through the opening 29j. Insulating oil that is a liquid electrical insulating material is inserted into the internal space of the metal tube 29. 31 has been injected. An attachment flange 27f is formed between the valve portion 27a and the target accommodating portion 27d of the X-ray tube 27, and the X-ray tube 27 is fixed to the distal end surface of the metal tube 29 by the attachment flange 27f. The part 27 a is immersed in the insulating oil 31. By adopting the insulating oil 31, the valve portion 27a of the X-ray tube 27 is surrounded by the insulating oil 31, and discharge from the X-ray tube 27 to the outside is prevented.

  Next, the control unit 7 will be described. As shown in FIGS. 1 and 4, the control unit 7 is provided in the control unit accommodating space R <b> 2 and includes a first circuit board 35, a second circuit board 37, and a drive power supply unit 39. The first circuit board 35 controls the voltage that can be generated by the high-voltage power supply unit 17 from a high voltage (for example, 160 kV) to a low voltage (for example, 0 V). Further, the first circuit board 35 controls the electron emission timing, tube voltage, tube current, and the like in the electron gun unit 27e. The second circuit board 37 controls the operation of the first circuit board 35 based on a control signal from the outside. The drive power supply unit 39 is a converter that performs AC / DC conversion (or DC / DC conversion) on electric power supplied from the outside, and supplies drive power to the first circuit board 35 and the second circuit board 37 and X Electric power for generating a high voltage is supplied to the high voltage transformer 19 of the line generator 5. Note that the first circuit board 35, the second circuit board 37, the drive power supply unit 39, and the X-ray generation unit 5 are appropriately connected to each other by wires (not shown).

  Since many electronic components are mounted on the first circuit board 35, the second circuit board 37, and the drive power supply unit 39, strong vibration is applied when the X-ray source 1 is used while being moved. For example, the circuit may be disconnected. Further, if the substrate or the like continues to vibrate, the life is shortened. For this reason, these circuit boards 35 and 37 and the drive power supply part 39 need to be stably and reliably fixed to the bottom plate 3a in order to reduce vibration. Therefore, the control unit 7 is provided with a circuit board holder 49 made of a heat conductive metal (for example, aluminum) in the control unit accommodating space R2. The circuit board holder 49 includes the first circuit board 35, the first circuit board 35, and the second circuit board holder 49. A two-circuit board 37 and a drive power supply unit 39 are held.

  The circuit board holder 49 is a member formed by bending a single plate-like member made of a heat conductive metal, and includes a first flat plate portion 46 erected in an inclined manner with respect to the bottom plate 3a, and a bottom plate A second flat plate portion 48 erected substantially perpendicular to 3a, a third flat plate portion 50 provided substantially parallel to the bottom plate 3a, and a fourth erected substantially perpendicular to the bottom plate 3a. And a flat plate portion 52. The first flat plate portion 46 and the second flat plate portion 48 respectively extend along surfaces intersecting with each other at an acute angle α, and the first flat plate portion 46 is an inclined wall 3d of the housing 3 described later. It extends almost parallel to the. The circuit board holder 49 has a plurality of (for example, three) screws 49a in a state in which the foot 45j below the first flat plate portion 46 and the foot 47j below the fourth flat plate portion 52 are in contact with the bottom plate 3a. It is fixed by.

  The first flat plate portion 46 has a first mounting surface 45a for mounting the first circuit board 35, and the second flat plate portion 48 has a second mounting surface 47b for mounting the second circuit board 37. The third flat plate portion 50 has a third attachment surface 47 c for attaching the drive power supply portion 39. These mounting surfaces 45 a, 47 b, 47 c are provided on the outer surface of the circuit board holder 49.

  In this way, the circuit board holder 49 has a chevron structure to maintain the mechanical strength of the circuit board holder 49 itself, and a plurality of portions of the foot portions 45j and 47j are screwed to the bottom plate 3a. Is stably fixed against. Therefore, the circuit boards 35 and 37 and the drive power supply unit 39 attached to the circuit board holder 49 can be stably and reliably fixed to the bottom plate 3a. Further, since the first flat plate portion 46 of the circuit board holder 49 is provided so as to be inclined with respect to the bottom plate 3a, the first circuit board 35 can be accommodated in the control unit accommodating space R2 while being inclined, and the X-ray The height dimension of the source 1 can be reduced.

  A high voltage transformer 19 of the high voltage power supply unit 17 is accommodated in a space formed below the third flat plate unit 50.

  The first circuit board 35 is attached along the first attachment surface 45 a of the first plate 45 via the spacer 51. Similarly, the second circuit board 37 is attached along the second attachment surface 47 b of the second plate 47 via the spacer 51, and the drive power supply unit 39 is provided along the third attachment surface 47 c of the second plate 47. It is attached via a spacer 51.

  In such an X-ray source 1, since the X-ray tube 27 generates heat during operation, the X-ray tube 27 and the metal tube 29 become high temperature. The heat generated by the X-ray tube 27 increases as the output of the X-ray irradiation increases. If the temperature of the X-ray tube 27 becomes high, other parts are adversely affected and the output of the X-ray tube 27 is reduced. In order to cool the X-ray tube 27 efficiently, it is necessary to cool the metal tube 29 efficiently.

  Therefore, in the X-ray source 1, as shown in FIG. 1, the X-ray generation unit 5 including the metal tube 29 is stored inside the housing 3 and stands up in a direction orthogonal to the bottom plate 3 a of the housing 3. The cooling fan unit 55 is provided on the side wall (second wall) 3b, and the metal tube 29 is cooled by flowing cooling air in the housing 3.

  As shown in FIGS. 1 and 4, the housing 3 extends in parallel with the bottom plate 3 a and is provided with an opening (irradiation unit) 3 j for irradiating X-rays from the X-ray tube 27 to the outside. It has a wall (first wall) 3c. The opening 3j is provided at a position corresponding to the irradiation window 27h of the X-ray tube 27, and exposes the irradiation window 27h to the outside. Moreover, in the housing | casing 3, the wall which connects the upper wall 3c and the side wall 3b is formed as the inclined wall 3d. Further, the wall connecting the side wall 3f facing the side wall 3b and the upper wall 3c is also an inclined wall 3e. The degree of inclination of the inclined wall 3d and the inclined wall 3e with respect to the upper wall 3c may be different from each other or the same.

  The cooling fan unit 55 is provided on the side wall 3b of the housing 3 as described above, and includes the cooling fan 55a that rotates about an axis perpendicular to the side wall 3b. The cooling fan 55a rotates to cause air to flow from the outside to the inside of the housing 3. The cooling fan 55 a is located in the vicinity of the X-ray generator 5 so that the cooling air directly hits the X-ray generator 5.

  The air taken into the housing 3 by the cooling fan 55a flows in the X-ray generation unit accommodating space R1 as cooling air and passes around the metal cylinder 29 while uniformly hitting the metal cylinder 29. It will flow in the direction of the side wall 3f. Then, the cooling air passing around the metal tube 29 is guided by the cooling fins 29a and smoothly flows in the horizontal direction, and contacts the metal tube 29 with a sufficient contact area, and efficiently heats from the metal tube 29. Remove it. As a result, the metal tube 29 can be efficiently cooled, and the X-ray tube 27 surrounded by the metal tube 29 can be efficiently cooled. And since the metal cylinder 29 contacts the cooling air without any unevenness and is cooled, output fluctuation and output decrease due to temperature unevenness of the X-ray tube 27 can be suppressed. Thereafter, the cooling air that has received heat from the metal tube 29 and has increased in temperature is discharged to the outside through the exhaust port 3k provided in the inclined wall 3e.

  At this time, since the wall connecting the upper wall 3c and the side wall 3b is the inclined wall 3d, the stagnation of the cooling air is suppressed, and a smooth flow of the cooling air in the housing 3 can appear. it can. As a result, the cooling air smoothly flows around the metal cylinder 29, and the metal cylinder 29 can be efficiently cooled. In addition, since the wall which connects the upper wall 3c and the side wall 3f of the housing 3 is also the inclined wall 3e, this also contributes to the smooth flow of the cooling air. As described above, in the X-ray source 1, the metal tube 29 is efficiently cooled, so that the X-ray tube 27 can be efficiently cooled. Therefore, the output of the X-ray source can be increased.

  The X-ray source 1 has a connector part (not shown) connected to a personal computer or the like in a part of the side wall 3b on the control part accommodation space R2 side. Signals related to control information from a personal computer or the like are input / output via the. Of the casing 3 excluding the bottom plate 3a, the cooling fan unit 55 and the connector section (not shown) have wiring connections to the control section 7 and the like, so that they are different from other parts of the casing 3. If it is, it is preferable in terms of maintenance of the X-ray source 1 or the like. In the present embodiment, the cooling fan unit 55 and the connector part (not shown) are fixed to the bottom plate 3a and connected to the control part 7 by wiring.

  In addition, since the inclined wall 3d and the inclined wall 3e are formed in the housing | casing 3 of the X-ray source 1, the following effects are also acquired. When the inclined walls 3d and 3e are not formed, corners are formed between the upper wall 3c and the side walls 3b and 3f. Here, in the case where a fluoroscopic image in which the inspection object is tilted by such an X-ray source is acquired, the tilted inspection object hits a corner, and therefore the irradiation window 27h and the inspection object are sufficiently close to each other. I can't let you. Compared to this, in the X-ray source 1, the inspection object can be brought closer to the irradiation window 27h without being obstructed by the corners. For this reason, it is possible to obtain a fluoroscopic image of the inspection object having a larger magnification.

  In such an X-ray source 1, as described above, various electronic components are mounted on the first and second circuit boards 35 and 37 and the drive power supply unit 39 of the control unit 7. In order to stabilize the operating characteristics of each component, it is necessary to cool these components. In particular, the drive power supply unit 39 generates a large amount of heat when performing AC / DC conversion (or DC / DC conversion), and thus needs to be efficiently cooled.

  Therefore, the partition wall 15 in the housing 3 partitions the metal tube 29 and the control unit 7 without completely partitioning the X-ray generation unit housing space R1 and the control unit housing space R2, and below the partition wall 15. Is provided with a vent hole 59 for communicating the X-ray generation unit accommodation space R1 and the control unit accommodation space R2. Thus, since the partition between the metal cylinder 29 and the control unit 7 is partitioned by the partition wall 15, the cooling air that has become high temperature after the cooling of the metal cylinder 29 may directly flow into the control unit accommodating space R2. Can be suppressed. Further, it is possible to suppress the radiant heat generated from the metal cylinder 29 from being blocked by the partition wall 15 and directly transmitted to the control unit 7. As a result, the temperature rise of the control unit 7 can be suppressed, and the operations of the circuit boards 35 and 37 of the control unit 7 can be stabilized. At the same time, since the X-ray generation unit accommodation space R1 and the control unit accommodation space R2 are communicated with each other through the ventilation port 59, a part of the cooling air generated by the cooling fan 55a is transmitted through the ventilation port 59 to the control unit accommodation space R2. Therefore, the controller 7 can be cooled by the cooling air.

  At this time, part of the cooling air that has flowed into the control unit accommodation space R <b> 2 through the ventilation holes 59 flows into the ventilation spaces R <b> 2 b and R <b> 2 c outside the circuit board holder 49. The ventilation space R2b is formed as a gap between the first flat plate portion 46, the side wall 3b, and the inclined wall 3d, and the cooling air flowing into the ventilation space R2b flows around the first circuit board 35. The first circuit board 35 is cooled. At this time, since the first flat plate portion 46 extends substantially parallel to the inclined wall 3d, the ventilation space R2b has a substantially constant width. For this reason, in this ventilation space R2b, the cooling air flows smoothly without stagnation, and the first circuit board 35 can be efficiently cooled. Thereafter, a part of the cooling air is discharged to the outside through the exhaust port 3q provided in the inclined wall 3d, and the remaining part flows between the upper wall 3c and the circuit board holder 49 into the ventilation space R2c.

  On the other hand, the cooling air flowing into the ventilation space R2c from the ventilation port 59 flows in a direction from the ventilation port 59 toward the exhaust port 3h (see FIGS. 1 and 2) provided in the side wall 3g. The cooling air efficiently cools the driving power supply unit 39 while sufficiently contacting the driving power supply unit 39, and is discharged to the outside through the exhaust port 3h provided in the side wall 3g. In this way, the drive power supply 39 that generates high heat can be efficiently cooled, and the operation of the drive power supply 39 can be stabilized.

  The cooling air flowing into the ventilation space R2c from the ventilation space R2b cools the second circuit board 37 while flowing around the second circuit board 37, and further flows around the driving power supply part 39 while driving the drive power supply part. After cooling 39, it is discharged to the outside through the exhaust port 3r provided in the inclined wall 3e and the side wall 3f. At this time, since the upper wall 3c and the side wall 3f of the housing 3 are connected by the inclined wall 3e, the cooling air flowing in the ventilation space R2c flows without stagnation along the walls 3c, 3e, 3f, Smooth cooling air flow will occur. A part of the cooling air flowing in the ventilation space R2c is discharged through the exhaust port 3s provided in the upper part of the inclined wall 3e.

  Since the drive power supply unit 39 generates high heat, the cooling air after cooling the drive power supply unit 39 becomes high temperature. However, since the drive power supply unit 39 is located in the vicinity of the exhaust port 3r, the high temperature The cooling air is quickly discharged to the outside from the exhaust port 3r. Therefore, since the cooling air around the drive power supply unit 39 flows smoothly, the drive power supply unit 39 can be efficiently cooled, and the operation characteristics of the components of the drive power supply unit 39 can be stabilized. Furthermore, it is possible to prevent the cooling air whose temperature has risen from flowing back into the ventilation spaces R2c and R2b and the temperature of the first circuit board 35 and the second circuit board 37 from rising. The operation characteristics of the components of the circuit board 35 and the second circuit board 37 can be stabilized.

  The first circuit board 35, the second circuit board 37, and the drive power supply unit 39 are mounted in a state of being lifted from the mounting surfaces 45a, 47b, and 47c via the spacers 51. The first circuit board 35, the second circuit board 37, and the driving power supply unit 39 are in contact with both front and back sides. Therefore, this way of attachment also contributes to efficient cooling of the first circuit board 35, the second circuit board 37, and the drive power supply unit 39.

  As shown in FIG. 4, a tunnel portion R2a surrounded by the circuit board holder 49 and the bottom plate 3a appears in the control portion accommodating space R2, and cooling air from the vent 59 flows into the tunnel portion R2a. To do. Since this tunnel portion R2a extends in a direction in which the cooling air flows in through the ventilation opening 59 (a direction perpendicular to the paper surface of FIG. 4), a smooth flow of the cooling air that concentrates on the tunnel portion R2a is generated. appear. In the tunnel portion R2a, the high voltage transformer 19 provided so as to protrude from the insulating block 21 is present. Therefore, high heat generated in the high voltage transformer 19 is efficiently removed by the cooling air, and the high voltage transformer 19 is concentrated. Efficient and efficient cooling. Thereafter, the cooling air that has received heat from the high-voltage transformer 19 and has risen in temperature is discharged to the outside through an exhaust port 3 h (see FIGS. 1 and 2) provided in the side wall 3 g of the housing 3.

  In addition, since the smooth cooling air flow is generated in the tunnel portion R2a as described above, for example, another circuit board is attached to the surface opposite to the first attachment surface 45a and the second attachment surface 47b, The circuit board may be disposed in the tunnel portion R2a and cooled.

  Further, among the components of the first circuit board 35, the power transistor 61 (see FIG. 2) generates a relatively large amount of heat, so that it is separated from the first circuit board 35, and the high voltage power supply unit 17, the cooling fan unit 55, It is installed in close contact with a metal heat sink 63 provided between the two. At this time, the power transistor 61 functions as a component of the first circuit board 35 by being electrically connected to the first circuit board 35 through a wiring (not shown). With such an arrangement, the heat sink 63 is cooled by receiving the cooling air from the cooling fan 55 a, and the power transistor 61 in close contact with the heat sink 63 is indirectly cooled. As described above, by separately cooling components that generate particularly large heat away from the circuit board main body, the temperature rise of the control unit 7 can be effectively suppressed.

(Second Embodiment)
As shown in FIG. 5, the circuit board holder 49 of the X-ray source 71 includes a first plate 45 and a second plate 47 made of a heat conductive metal. The first plate 45 has a first flat plate portion 46 that is inclined and erected with respect to the bottom plate 3a, and the second plate 47 is a second flat plate that is erected substantially perpendicular to the bottom plate 3a. Part 48, a third flat plate portion 50 provided substantially parallel to the bottom plate 3a, and a fourth flat plate portion 52 erected substantially perpendicular to the bottom plate 3a.

  The first plate 45 is fixed by a plurality of (for example, three) screws 49a in a state where the foot portion 45j is in contact with the bottom plate 3a, and the second plate 47 is in a state in which the foot portion 47j is in contact with the bottom plate 3a. And are fixed by a plurality of (for example, three) screws 49a. Furthermore, the upper ends of the plates 45 and 47 are connected to each other by screws 49b in an overlapped state. Also by such a circuit board holder 49, the circuit boards 35 and 37 and the drive power supply part 39 attached to the circuit board holder 49 can be stably and reliably fixed to the bottom plate 3a.

  Further, the X-ray source 71 includes a cooling fan unit 77 that is different from the cooling fan unit 55 on the control unit accommodation space R <b> 2 side of the housing 73. The cooling fan unit 77 is provided in an exhaust port 73r formed in the side wall 3f in the vicinity of the drive power supply unit 39, and is an exhaust type unit for sending air inside the housing 73 to the outside. The cooling fan unit 77 includes a cooling fan 77a and a motor 77b that rotates the cooling fan 77a. When the cooling fan 77a rotates, the air inside the housing 73 is sent to the outside. By providing the cooling fan unit 77 at the exhaust port 73r located in the vicinity of the drive power supply unit 39, the cooling air that has become hot due to the cooling of the drive power supply unit 39 can be discharged to the outside more quickly. it can.

  With such a configuration of the X-ray source 71, the drive power supply unit 39 can be cooled more efficiently, and the cooling air that has cooled the drive power supply unit 39 flows back to the ventilation spaces R2c and R2b and flows into the first circuit board 35 and the second circuit. It can suppress that the temperature of the board | substrate 37 raises on the contrary. As a result, the operation characteristics of the components of the first circuit board 35, the second circuit board 37, and the drive power supply unit 39 can be stabilized.

  Further, in the X-ray source 71, the cooling fan 77a sends out the air in the housing 3 to the outside, so that the flow of the cooling air in the entire housing 3 is accelerated, so that the X-ray generation unit 5 and the control unit 7 are connected. It can cool more efficiently.

  Further, the X-ray generation unit accommodation space R1 and the control unit accommodation space R2 may be partitioned. In this case, if a cooling fan is provided in each of the X-ray generation unit housing space R1 and the control unit housing space R2, cooling can be performed intensively by causing the cooling air to flow intensively in each space.

  In addition, this invention is not limited to the said embodiment. The circuit board holder 49 is not limited to screwing, and may be fixed to the bottom plate 3a by welding or adhesion. Further, the circuit board holder 49 may be fixed to a portion other than the bottom plate 3 a of the housing 3 or may be fixed to a member fixed to the housing 3. Moreover, the 1st plate 45 and the 2nd plate 47 may be connected not only by screwing but by welding or adhesion | attachment. The circuit board holder 49 is not limited to one consisting of one member or two members including the first plate 45 and the second plate 47, and may be formed by combining a number of members. In this case, bending can be omitted by forming a circuit board holder by combining a large number of flat plate members. The circuit board holder 49 is not limited to a heat conductive metal, and may be made of resin.

  Further, the arrangement of the cooling fan 55a is not limited to the side wall 3b, and may be provided in other parts as long as the cooling air flows around the circuit board holder 49. For example, by providing a ventilation opening in the housing 3 and arranging a cooling fan in the vicinity of the ventilation opening and inside the housing 3, the cooling air can flow between the first flat plate portion 45 and the second flat plate portion 47. May be. The X-ray source 1 may include a plurality of cooling fans. In this case, a plurality of cooling fans of the same type may be arranged, but a combination of an intake type cooling fan and an exhaust type cooling fan can be used.

  In addition, when the X-ray generation unit accommodating space R1 and the control unit accommodating space R2 are not partitioned, an intake type cooling fan is provided on the X-ray generation unit accommodating space side R1, and an exhaust type cooling fan is provided on the control unit accommodating space R2 side. A cooling fan may be provided, an exhaust type cooling fan may be provided on the X-ray generation unit accommodation space side R1, and an intake type cooling fan may be provided on the control unit accommodation space R2 side.

  The X-ray tube 27 may be a sealed X-ray tube or an open X-ray tube. The X-ray tube 27 may be a transmissive target type instead of a reflective target type. The entire X-ray tube 27 may be accommodated in a metal tube 29. In this case, in order to irradiate the X-ray from the X-ray tube 27 to the outside, the metal tube 29 has a portion with high X-ray permeability. Can be provided. A part of the X-ray tube 27 may protrude from the metal tube 29 and further protrude from the housing 3. The metal cylinder 29 surrounding the X-ray tube 27 may not be provided with the cooling fin 29a.

  Further, the X-ray generator 5 may not be accommodated in the housing 3.

  The above-described configurations can be combined with each other without departing from the spirit of the present invention.

1 is an exploded perspective view showing a first embodiment of an X-ray source according to the present invention. It is a front view of the X-ray source shown in FIG. It is sectional drawing of the X-ray generation part of the X-ray source shown in FIG. It is sectional drawing of the control part of the X-ray source shown in FIG. It is sectional drawing which shows 2nd Embodiment of the X-ray source which concerns on this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,71 ... X-ray source, 3c ... Upper wall (1st wall), 3b ... Side wall (2nd wall), 3,73 ... Housing | casing, 3j ... Opening (irradiation part), 3d ... Inclined wall, 3r 73r ... exhaust port, 5 ... X-ray generator, 27 ... X-ray tube, 35 ... first circuit board, 37 ... second circuit board, 39 ... drive power supply, 46 ... first flat plate part, 48 ... 2nd flat plate part, 49 ... Circuit board holder, 55a, 77a ... Cooling fan.

Claims (5)

An X-ray generator having an X-ray tube and irradiating the outside with X-rays;
A circuit board holder that is housed in a housing and supports a circuit board that controls the X-ray generator;
A cooling fan that causes cooling air to flow around the circuit board holder inside the housing, and
The circuit board holder has a first flat plate portion and a second flat plate portion that are fixed in the housing and are opposed to each other and connected to each other.
The X-ray source, wherein the circuit board is fixed to at least one of the first flat plate portion and the second flat plate portion.   2. The X-ray source according to claim 1, wherein an end portion of the first flat plate portion and an end portion of the second flat plate portion are connected to each other.   The X-ray source according to claim 1 or 2, wherein an interior angle between the first flat plate portion and the second flat plate portion is an acute angle. The housing is
A first wall having an irradiation unit for irradiating the X-ray from the X-ray tube;
A second wall extending in a direction substantially orthogonal to the first wall and provided with the cooling fan;
An inclined wall that connects the first wall and the second wall and extends substantially parallel to the first flat plate portion. The X-ray source according to claim 1.   A drive power supply unit that supplies drive power to the X-ray generation unit is provided, and the drive power supply unit is fixed to the circuit board holder and is positioned in the vicinity of an exhaust port provided in the housing. The X-ray source according to claim 1.

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