CN104091748A - Ionization chamber adjusting device - Google Patents
Ionization chamber adjusting device Download PDFInfo
- Publication number
- CN104091748A CN104091748A CN201410325912.6A CN201410325912A CN104091748A CN 104091748 A CN104091748 A CN 104091748A CN 201410325912 A CN201410325912 A CN 201410325912A CN 104091748 A CN104091748 A CN 104091748A
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- ionization chamber
- guide rail
- adjusting device
- movable object
- platform
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Abstract
The invention relates to an ionization chamber adjusting device. The ionization chamber adjusting device comprises a base and an ionization chamber position adjusting device, wherein a first guide rail is arranged on the base. The ionization chamber position adjusting device comprises a first-level mobile carrying platform, a second-level mobile carrying platform and a third-level mobile carrying platform, wherein the first-level mobile carrying platform horizontally moves on the first guide rail and is provided with a second guide rail, the first guide rail is in the X-ray main beam direction, and the direction of the second guide rail is perpendicular to the direction of the first guide rail. The second-level mobile carrying platform horizontally moves on the second guide rail. The third-level mobile carrying platform comprises a vertical lifting adjusting platform, and a clamp clamping ionization chamber is arranged on the vertical lifting adjusting platform which is used for adjusting the height of an ionization chamber. The first-level mobile carrying platform is adjusted to horizontally move on the first guide rail, the second-level mobile carrying platform is adjusted to horizontally move on the second guide rail, the vertical lifting adjusting platform adjusts the height of the ionization chamber, a laser center is made to be aligned with a sensitive volume center of the ionization chamber, and the laser center is the same as an X-ray main beam center. By means of the ionization chamber adjusting device, the position of the ionization chamber can be conveniently and accurately adjusted.
Description
Technical field
The present invention relates to a kind of ionization chamber adjusting device, relate in particular to the adjusting device of a kind of ionization chamber position.
Background technology
X ray standard radiation appliance is for the calibrating of X-radiation instrument, calibration and detection, and the field such as industrial nondestructive testing, need to be held very easily and position adjustment for ionization chamber to be detected, makes thus X ray inject easily.
Summary of the invention
The object of the invention is the defect for prior art, a kind of ionization chamber adjusting device is provided, thereby realize the adjustment of convenient and accurate ionization chamber position.
For achieving the above object, the invention provides a kind of ionization chamber adjusting device, described ionization chamber adjusting device comprises:
Pedestal, has the first guide rail on described pedestal;
Ionization chamber position regulator, comprising:
One-level movable object-carrying stage, is slidably installed on the first guide rail, translation on described the first guide rail, and there is the second guide rail, and described the first guide rail is along X ray main beam direction, and described the second guide rail is vertical with the direction of described the first guide rail;
Secondary movable object-carrying stage, is slidably installed on described the second guide rail translation on described the second guide rail;
Three grades of movable object-carrying stages, connect with described secondary movable object-carrying stage, comprise vertical lifting adjustment platform, and described vertical lifting is adjusted on platform has fixture clamping ionization chamber, for regulating the height of described ionization chamber;
Wherein, regulate the translation on described the first guide rail of one-level movable object-carrying stage, the translation on described the second guide rail of secondary movable object-carrying stage, vertical lifting is adjusted platform and is regulated described ionization chamber height, make laser center aim at the sensitive volume center of described ionization chamber, described laser center is identical with described X ray main beam center.
Further, described secondary movable object-carrying stage comprises: slide block, establish with described the second guide rail cunning; Leading screw, one end is connected with motor, and the other end is connected with described slide block, drives leading screw to drive described slide block to slide at described the second guide rail by described motor.
Further, described vertical lifting is adjusted platform and is had support arm and first rotating shaft of intersection, thereby changes the intersecting angle adjusting height of described support arm by rotating described the first rotating shaft.
Further, described fixture comprises:
Subbase, described subbase has screwed hole, utilizes screw and support platform to fix;
Support bar, is screwed onto on described subbase, and the upper end of described support bar has socket;
Clamp head, described clamp head comprises:
Fixed part, described fixed part utilizes connecting rod to be plugged on the socket of described support bar;
Moving-member, comprises Metallic rod, and one end of Metallic rod is plugged on described fixed part, and the other end utilizes connector to fix, and on described connector, has opened screw; Clamping part, is socketed in described Metallic rod; Adjusting rod, is screwed onto in described screw, and one end is adjusting head, and the other end and described clamping part fix;
Wherein, while regulating described adjusting head, be arranged in adjusting rod and described Metallic rod parallel in described screw, adjusting rod drives described clamping part and described fixed part jointly to clamp ionization chamber.
Further, the material of described subbase, support bar, fixed part, connecting rod, clamping part and connector is polymethyl methacrylate.
Further, the material of described Metallic rod and adjusting rod is metal.
Further, the opposite face of described fixed part and clamping part is plane or arcwall face, and the opposite face of described clamping part and fixed part is plane or arcwall face.
Ionization chamber adjusting device of the present invention has realized the adjustment of convenience and accurate ionization chamber position.
Brief description of the drawings
Fig. 1 is the schematic diagram of ionization chamber adjusting device of the present invention;
Fig. 2 is the working state schematic representation of ionization chamber adjusting device of the present invention
Fig. 3 is the schematic diagram of the fixture of ionization chamber adjusting device of the present invention;
Fig. 4 is the vertical view of the clamp head of ionization chamber adjusting device of the present invention.
Embodiment
Below by drawings and Examples, technical scheme of the present invention is described in further detail.
Fig. 1 is the schematic diagram of ionization chamber adjusting device of the present invention, and Fig. 2 is the working state schematic representation of ionization chamber adjusting device of the present invention; As shown in the figure, ionization chamber position regulator of the present invention comprises: pedestal 5 and ionization chamber position regulator 6.
Ionization chamber position regulator 6 comprises one-level movable object-carrying stage 1, secondary movable object-carrying stage 2 and three grades of movable object-carrying stages 3.
On pedestal 5, there is the first guide rail 10.
One-level movable object-carrying stage 1 is slidably installed on the first guide rail 10, translation on the first guide rail 10, and there are the second guide rail 11, the first guide rails 10 along X ray main beam direction, the second guide rail 11 is vertical with the direction of the first guide rail 10; Secondary movable object-carrying stage 2, is slidably installed on the second guide rail 11 translation on the second guide rail 11; Three grades of movable object-carrying stages 3 connect with secondary movable object-carrying stage 2, comprise vertical lifting adjustment platform 30, have fixture 7 and clamp ionization chamber, for regulating the height of ionization chamber on vertical lifting adjustment platform 30; Regulate 1 translation on the first guide rail 10 of one-level movable object-carrying stage, secondary movable object-carrying stage 2 translation on the second guide rail 11, vertical lifting is adjusted platform 30 and is regulated ionization chamber height, makes laser center aim at the sensitive volume center of ionization chamber, and laser center is identical with X ray main beam center.
Concrete, one-level movable object-carrying stage 1 is along the X-axis adjustment of X ray beam direction.Secondary movable object-carrying stage 2 in horizontal plane along the Y-axis adjustment perpendicular to X-direction.Three grades of movable object-carrying stages 3, along the lift adjustment of vertical direction, are Z axis adjustment.
The first guide rail 10 is fixed on pedestal 5, and pedestal 5 is fixed on ground by expansion bolt, and ensures afterwards the level of pedestal 5 in installation.The flatness levelness of pedestal 5 upper surfaces is less than 1mm, with the horizontality that ensures that the first guide rail 10 and grating scale are installed.The first guide rail 10 is that two closed slides are fixedly installed on pedestal 5 by screw, and the one-level movable object-carrying stage 1 carrying with top is connected by slide block.Tooth bar is installed on pedestal 5 right sides and is fixed on pedestal 5 by screw, and tooth bar is connected by gear with the one-level movable object-carrying stage motor on the first guide rail 10, in order to complete the accurate movement of whole one-level movable object-carrying stage 1.Grating scale is arranged on the left margin of pedestal, realizes the axial accurate location of one-level movable object-carrying stage 1X by transducer.One-level article carrying platform 1 is placed in the first guide rail 10 tops, for secondary movable object-carrying stage 2 and three grades of movable object-carrying stages 3, and comprises two the second guide rails 11 along Y direction.
Secondary movable object-carrying stage 2 comprises slide block, leading screw and motor, and slide block and the second guide rail cunning are established; One end of leading screw is connected with motor, and the other end is connected with slide block, drives leading screw band movable slider to slide at the second guide rail by motor.
Concrete, between secondary movable object-carrying stage 2 and the second guide rail 11, be connected by slide block.Leading screw is parallel with two second guide rails 11, be placed in guideway centreline, one end is connected with motor, the other end is fixed on (leading screw can be realized rotation) on one-level article carrying platform 1, leading screw is similar to the structure of nut device through being fixed on secondary article carrying platform 2 lower surfaces, thereby rotates to realize the movement of secondary movable object-carrying stage 2 in Y direction by driven by motor leading screw.
Three grades of movable object-carrying stages 3 comprise vertical lifting adjustment platform, for example, be the Manual lifting platform of cultrating, and have support arm and first rotating shaft of intersection, thereby change the intersecting angle adjusting height of described support arm by rotating described the first rotating shaft.Also comprise that lappingout leading screw drives, the upper and lower surface multi-hole position design Manual lifting platform of cultrating, is furnished with locking handwheel, fixes by screw with secondary article carrying platform 2.Vertical lifting is adjusted platform upper surface multiple screwed holes, can realize fixture and be fixed on hoistable platform upper surface by screw.
Ionization chamber is finally to clamp by fixture, is fixed on three grades of movable object-carrying stages 3.
The fixture adapting with ionization chamber model is installed on three utmost point article carrying platforms 3, is taken out ionization chamber to be measured and be clamped by fixture.Connect ionization chamber measuring system.Adjust secondary utmost point article carrying platform and three grades of utmost point article carrying platform positions, make cross laser center (cross laser center is X ray main beam center) impinge upon the sensitive volume center of ionization chamber.
Open afterwards X ray ray machine, X-ray machine parameter is set, rotate the additional rotating disk that filters in experiment required specification place.Carry out X-axis by stepping motor software control one-level article carrying platform and move to service position.Then start to carry out the measurement of ionization chamber ionization current, under this specification, measure complete, save data.Adjust again X-ray machine parameter, adjust X-axis position, measure different specification.
Due to the difference of the type kind of ionization chamber, the specification difference of measurement, therefore need to measure at the diverse location place of distance X ray tube, that is to say the X-axis position adjustment needing in measuring process.Due to the difference of the size of ionization chamber, for making the sensitive volume of ionization chamber be positioned at the center of X ray main beam, therefore different ionization chambers need to carry out the position adjustment of different Y-axis and Z axis.
Finally by completing Y-axis and Z axis moves, the center of the sensitive locations of carrying out ionization chamber in X-ray beam.Move position by X-axis, completes the measurement of different ionization chamber different specification.
Fig. 3 is the schematic diagram of the fixture of ionization chamber adjusting device of the present invention, and Fig. 4 is the vertical view of the clamp head of ionization chamber adjusting device of the present invention, and as shown in the figure, fixture specifically comprises: subbase 73, support bar 72 and clamp head 71.Clamp head 71 comprises fixed part 711 and moving-member 710.
Subbase 73 has screwed hole, utilizes screw and three grades of movable object-carrying stages to fix; Support bar 72 is screwed onto on subbase 73, and the upper end of support bar 72 has socket.
Fixed part 711 utilizes connecting rod 7110 to be plugged on the socket of support bar 72.Moving-member 710 comprises Metallic rod 7100, and one end of Metallic rod 7100 is plugged on fixed part 711, and the other end utilizes connector 7101 to fix, and has opened screw 7102 on connector 7101; Clamping part 7103 is socketed in Metallic rod 7100; Adjusting rod 7104 is screwed onto in screw 7102, and one end is adjusting head 7105, and the other end and clamping part 7103 fix.
While regulating adjusting head 7105, be arranged in adjusting rod 7104 and Metallic rod 7100 parallels in screw 7102, adjusting rod 7104 drives the common clamping ionization chamber of clamping part 7103 and fixed part 711.
Concrete, the material of subbase 73 is machine glass, is 10 centimetres of diameters, the disk of thick 1 centimetre has 9 rounded distributions in minor thread hole, realizes the fixing of subbase 73 and support platform by screw.There is 1 major thread hole slightly at subbase 73 centers, can realize support bar 72 and be screwed into, for fixed support bar 72.
The material of support bar 72 is polymethyl methacrylate, and the 7 bar 2 bottom bar faces of support are threaded, and can be screwed into subbase 73.Support bar 72 upper ends are that hollow tube assembling structure is socket, can realize the insertion of the connecting rod 7110 of clamp head 71, be screwed into fixed part 711 realize fixing locked by connecting rod 7110 upper side.
Fixed part 711 is a square polymethyl methacrylate body.Clamping part 7103 is socketed in Metallic rod 7100, can move along Metallic rod, and concrete shift motion is determined by adjusting rod 7104, utilizes adjusting head 7105 to rotate adjusting rod 7104, approaches and away from fixed part 711, realizes holding function to realize clamping part 7103.
The course of work is specific as follows:
Preliminary installation: on screw firm banking dish and ionization chamber three-dimensional regulation platform, according to ionization chamber size, select certain height support bar to be screwed into base disk.According to ionization chamber model, select different clamp head.
The clamping part of clamp head and the opposite face of fixed part can carry out different selections according to the ionization chamber of different model and shape, and the face relative to each other of for example fixed part and clamping part is plane parallel to each other, or symmetrical arcwall face, or parallel cambered surface.
After installing fixture, put into ionization chamber between fixture moving-member and fixed part.Threaded together bar, fixes ionization chamber.
Because ionization chamber model varies in size, therefore fixture of the present invention need to be fixed on different positions ionization chamber, can select the support bar of different length.Because the distinctive appearance structure of ionization chamber, can select different clamp head.Finally complete the fixing of ionization chamber.
Above-described embodiment; object of the present invention, technical scheme and beneficial effect are further described; institute is understood that; the foregoing is only the specific embodiment of the present invention; the protection range being not intended to limit the present invention; within the spirit and principles in the present invention all, any amendment of making, be equal to replacement, improvement etc., within all should being included in protection scope of the present invention.
Claims (7)
1. an ionization chamber adjusting device, is characterized in that, described ionization chamber adjusting device comprises:
Pedestal, has the first guide rail on described pedestal;
Ionization chamber position regulator, comprising:
One-level movable object-carrying stage, is slidably installed on the first guide rail, translation on described the first guide rail, and there is the second guide rail, and described the first guide rail is along X ray main beam direction, and described the second guide rail is vertical with the direction of described the first guide rail;
Secondary movable object-carrying stage, is slidably installed on described the second guide rail translation on described the second guide rail;
Three grades of movable object-carrying stages, connect with described secondary movable object-carrying stage, comprise vertical lifting adjustment platform, and described vertical lifting is adjusted on platform has fixture clamping ionization chamber, for regulating the height of described ionization chamber;
Wherein, regulate the translation on described the first guide rail of one-level movable object-carrying stage, the translation on described the second guide rail of secondary movable object-carrying stage, vertical lifting is adjusted platform and is regulated described ionization chamber height, make laser center aim at the sensitive volume center of described ionization chamber, described laser center is identical with described X ray main beam center.
2. ionization chamber adjusting device according to claim 1, is characterized in that, described secondary movable object-carrying stage comprises:
Slide block, establishes with described the second guide rail cunning;
Leading screw, one end is connected with motor, and the other end is connected with described slide block, drives leading screw to drive described slide block to slide at described the second guide rail by described motor.
3. ionization chamber adjusting device according to claim 1, is characterized in that, described vertical lifting is adjusted platform and had support arm and first rotating shaft of intersection, thereby changes the intersecting angle adjusting height of described support arm by rotating described the first rotating shaft.
4. ionization chamber adjusting device according to claim 1, is characterized in that, described fixture comprises:
Subbase, described subbase has screwed hole, utilizes screw and support platform to fix;
Support bar, is screwed onto on described subbase, and the upper end of described support bar has socket;
Clamp head, described clamp head comprises:
Fixed part, described fixed part utilizes connecting rod to be plugged on the socket of described support bar;
Moving-member, comprises Metallic rod, and one end of Metallic rod is plugged on described fixed part, and the other end utilizes connector to fix, and on described connector, has opened screw; Clamping part, is socketed in described Metallic rod; Adjusting rod, is screwed onto in described screw, and one end is adjusting head, and the other end and described clamping part fix;
Wherein, while regulating described adjusting head, be arranged in adjusting rod and described Metallic rod parallel in described screw, adjusting rod drives described clamping part and described fixed part jointly to clamp ionization chamber.
5. ionization chamber adjusting device according to claim 1, is characterized in that, the material of described subbase, support bar, fixed part, connecting rod, clamping part and connector is polymethyl methacrylate.
6. ionization chamber adjusting device according to claim 1, is characterized in that, the material of described Metallic rod and adjusting rod is metal.
7. ionization chamber adjusting device according to claim 1, is characterized in that, the opposite face of described fixed part and clamping part is plane or arcwall face, and the opposite face of described clamping part and fixed part is plane or arcwall face.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410325912.6A CN104091748B (en) | 2014-07-09 | 2014-07-09 | Ionization chamber adjusting means |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410325912.6A CN104091748B (en) | 2014-07-09 | 2014-07-09 | Ionization chamber adjusting means |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104091748A true CN104091748A (en) | 2014-10-08 |
| CN104091748B CN104091748B (en) | 2016-08-17 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410325912.6A Expired - Fee Related CN104091748B (en) | 2014-07-09 | 2014-07-09 | Ionization chamber adjusting means |
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| CN (1) | CN104091748B (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104690699A (en) * | 2015-03-13 | 2015-06-10 | 中国计量科学研究院 | Multi-dimensional displacement platform |
| CN104934285A (en) * | 2015-07-03 | 2015-09-23 | 中国计量科学研究院 | An ionization chamber measuring volume adjusting device |
| CN106483549A (en) * | 2016-10-28 | 2017-03-08 | 中国计量科学研究院 | Detection method based on ionization chamber system |
| CN106548919A (en) * | 2016-10-28 | 2017-03-29 | 中国计量科学研究院 | Ionization chamber detecting system |
| CN109959963A (en) * | 2019-04-29 | 2019-07-02 | 中国计量科学研究院 | A kind of ionisation chamber fixture |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4424443A (en) * | 1979-10-13 | 1984-01-03 | Hauni-Werke Ko/ rber & Co. KG. | Apparatus for measuring the density of cigarette rods or the like |
| US4503329A (en) * | 1981-09-30 | 1985-03-05 | Hitachi, Ltd. | Ion beam processing apparatus and method of correcting mask defects |
| CN1458548A (en) * | 2002-03-20 | 2003-11-26 | Lg.菲利浦Lcd株式会社 | Adhesive device for producing liquid crystal display device |
| CN102706910A (en) * | 2012-05-30 | 2012-10-03 | 中国科学院上海应用物理研究所 | Multi-dimensional adjustment platform |
-
2014
- 2014-07-09 CN CN201410325912.6A patent/CN104091748B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4424443A (en) * | 1979-10-13 | 1984-01-03 | Hauni-Werke Ko/ rber & Co. KG. | Apparatus for measuring the density of cigarette rods or the like |
| US4503329A (en) * | 1981-09-30 | 1985-03-05 | Hitachi, Ltd. | Ion beam processing apparatus and method of correcting mask defects |
| CN1458548A (en) * | 2002-03-20 | 2003-11-26 | Lg.菲利浦Lcd株式会社 | Adhesive device for producing liquid crystal display device |
| CN102706910A (en) * | 2012-05-30 | 2012-10-03 | 中国科学院上海应用物理研究所 | Multi-dimensional adjustment platform |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104690699A (en) * | 2015-03-13 | 2015-06-10 | 中国计量科学研究院 | Multi-dimensional displacement platform |
| CN104690699B (en) * | 2015-03-13 | 2017-03-22 | 中国计量科学研究院 | Multi-dimensional displacement platform |
| CN104934285A (en) * | 2015-07-03 | 2015-09-23 | 中国计量科学研究院 | An ionization chamber measuring volume adjusting device |
| CN106483549A (en) * | 2016-10-28 | 2017-03-08 | 中国计量科学研究院 | Detection method based on ionization chamber system |
| CN106548919A (en) * | 2016-10-28 | 2017-03-29 | 中国计量科学研究院 | Ionization chamber detecting system |
| CN106483549B (en) * | 2016-10-28 | 2019-09-27 | 中国计量科学研究院 | Detection method based on ionization chamber system |
| CN109959963A (en) * | 2019-04-29 | 2019-07-02 | 中国计量科学研究院 | A kind of ionisation chamber fixture |
| CN109959963B (en) * | 2019-04-29 | 2024-01-26 | 中国计量科学研究院 | Ionization chamber fixture |
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| CN104091748B (en) | 2016-08-17 |
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