CN108287035B - Dynamic impact force measuring device for integral hanger - Google Patents
Dynamic impact force measuring device for integral hanger Download PDFInfo
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- CN108287035B CN108287035B CN201810034575.3A CN201810034575A CN108287035B CN 108287035 B CN108287035 B CN 108287035B CN 201810034575 A CN201810034575 A CN 201810034575A CN 108287035 B CN108287035 B CN 108287035B
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- lifting ring
- force
- sensor
- sensors
- acceleration sensor
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- 230000001133 acceleration Effects 0.000 claims abstract description 33
- 230000003014 reinforcing effect Effects 0.000 claims description 15
- 238000012360 testing method Methods 0.000 claims description 8
- 238000005452 bending Methods 0.000 claims description 3
- 230000005540 biological transmission Effects 0.000 claims description 2
- 210000001624 hip Anatomy 0.000 claims description 2
- 238000000034 method Methods 0.000 claims 1
- 230000003137 locomotive effect Effects 0.000 abstract 2
- 230000009975 flexible effect Effects 0.000 description 4
- 238000009434 installation Methods 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- 238000001514 detection method Methods 0.000 description 2
- 238000007665 sagging Methods 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000003292 glue Substances 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L5/00—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
- G01L5/0052—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes measuring forces due to impact
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Train Traffic Observation, Control, And Security (AREA)
- Force Measurement Appropriate To Specific Purposes (AREA)
Abstract
The utility model provides a dynamic impact force measuring device of an integral hanger, which belongs to the field of rail transit and is used for detecting the dynamic impact force of the integral hanger when a locomotive pantograph works, and mainly comprises four main mechanical and electronic components of a lifting ring (1), a force sensor (2), an acceleration sensor (3) and a sensor interface (4); the lifting ring (1) can replace the lifting ring structure of the existing integral lifting string, and 2 force sensors (2) and 1 acceleration sensor (3) are respectively arranged at the left side and the right side of the lifting ring (1); 2 force sensors (2) and 1 acceleration sensor (3) on each side of the lifting ring (1) are surrounded into a triangle and are arranged in a triangle groove (6) of the lifting ring (1); the force sensor (2) and the acceleration sensor (3) are connected with the sensor interface (4), and the power impact force of the integral hanger is monitored in real time when the locomotive pantograph works.
Description
Technical Field
The invention belongs to the field of rail transit, and is suitable for detecting the dynamic impact force of an integral hanger.
Background
The integral hanger is an important component of an electrified railway and a high-speed railway contact net, and is a flexible clue connecting device which is connected with a carrier rope and a contact line. The contact net hangs the contact line above the train through the flexible integral hanger, and the pantograph and the contact line are in friction sliding current receiving during the running of the train, so that the power taking of the train is realized.
The integral hanger is a flexible clue, which mainly ensures that the contact line is positioned in a horizontal plane as much as possible and is always parallel to the running rail, thus realizing stable current receiving of the pantograph and the contact line. However, due to the weight of the contact line itself, the contact line is not in a straight line state and is always in a sagging state and is in a bending radian between two hanging strings. Meanwhile, the pantograph always has a certain upward acting force, so that the contact state of the pantograph slide plate and the contact line is ensured. When the pantograph passes through the dropper, the pantograph can have upward acting force on the dropper due to the sagging of the contact line and the flexible action of the dropper, and the dropper is lifted to move upwards or bend; when the pantograph passes, the lifted or bent dropper can quickly drop down, and the dropper is subjected to a large dynamic impact force.
When the whole dropper of the existing electrified railway and high-speed railway operates, failure phenomena such as wire breakage, strand breakage and the like of the dropper can occur, the main reasons of the failure are analyzed to be stress corrosion failure, and the dynamic impact force of the dropper is a main stress source. However, at home and abroad, the real-time monitoring of the dynamic impact force of the hanger is lacking, so that the actual stress of the hanger on a line cannot be accurately predicted during the design and detection of the hanger, the service life of the hanger is reduced, and the normal and safe operation of a train is threatened. When the train is monitored in real time, the dynamic impact force of the whole dropper has important value for accurately evaluating the service life of the dropper.
Disclosure of Invention
The invention discloses a technology to be solved, which is to design a dynamic impact force measuring device of an integral hanger for dynamic impact force detection of the integral hanger for rail transit.
The technical scheme adopted by the invention is as follows: the device for measuring the dynamic impact force of the integral hanger comprises a hanging ring (1), a force sensor (2), an acceleration sensor (3) and a sensor interface (4). The left side and the right side of the lifting ring (1) are symmetrical, the lifting ring structure of the existing integral lifting string can be replaced, the middle of the lifting ring (1) is connected by a reinforcing rib (5), and the rigidity of the lifting ring (1) is enhanced; triangle grooves (6) are formed in the left hanging ring (1) and the right hanging ring (1). The force sensor (2) and the acceleration sensor (3) are respectively arranged in the triangular grooves (6) on the left side and the right side of the lifting ring (1), 2 force sensors (2) and 1 acceleration sensor (3) are respectively arranged on each side of the lifting ring (1), and the force sensor (2) and the acceleration sensor (3) on each side are all arranged in the triangular grooves (6) around forming a triangle. The force sensor (2) and the acceleration sensor (3) are connected with a computer through a sensor interface (4) to collect real-time stress data of the whole dropper
The invention has the following characteristics:
The left side and the right side of the lifting ring (1) are symmetrical, a reinforcing rib (5) is arranged in the middle of the lifting ring (1), and isosceles triangle grooves (6) are formed in the left side and the right side of the lifting ring (1); the lifting ring (1) can replace the lifting ring structure of the integral hanger device on the existing electrified railway contact network.
2 Force sensors (2) and 1 acceleration sensor (3) can be arranged in isosceles triangle grooves (6) on the left side and the right side of the lifting ring (1), the force sensors (2) and the acceleration sensors (3) are connected with a computer through sensor interfaces (4), and dynamic impact force of the whole lifting string is collected in real time.
The force sensor (2) and the acceleration sensor (3) on each side of the lifting ring (1) are surrounded to form an isosceles triangle, the force sensor (2) is parallel to the side of the isosceles triangle groove (6) during installation, installation and measurement errors are effectively avoided, the 2 force sensors (2) on each side test the dynamic impact force of the whole lifting string, the force synthesis is used for solving the vertical force and the horizontal force component of the whole lifting string, the actual measurement value of each force sensor (2) in the vertical direction is equal, and the installation and measurement errors can be verified; and 1 acceleration sensor (3) at each side is used for testing the dynamic impact acceleration of the integral hanger and converting the dynamic impact force of the integral hanger according to the mass of the integral hanger.
The dynamic acting force of the integral hanger is calculated by the average value of a force sensor (2) and an acceleration sensor (3) at each side of the hanging ring (1).
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is obvious that the drawing in the following description is only one embodiment of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Drawings
Fig. 1 is a structural diagram of an integral hanger dynamic impact force measuring device provided by an embodiment of the invention, wherein in the figure, a hanging ring 1, a force sensor 2, an acceleration sensor 3, a sensor interface 4, a reinforcing rib 5 and a triangular groove 6 are arranged.
Fig. 2 is a left side view of fig. 1.
Fig. 3 is a front view of fig. 1.
Detailed Description
The structure of the integrated hanger dynamic impact force measuring device is schematically shown in fig. 1, 2 and 3, and the integrated hanger dynamic impact force measuring device comprises a hanging ring (1), a force sensor (2), an acceleration sensor (3), a sensor interface (4), a reinforcing rib (5) and a triangular groove (6).
The left side and the right side of the lifting ring (1) are symmetrical, the lifting ring (1) is provided with reinforcing ribs (5), as shown in fig. 1 and 3, the surface of each reinforcing rib (5) is in a curved surface shape, the bending radian of each reinforcing rib (5) is 120 degrees, the reinforcing ribs (5) are connected with the curved surfaces on the left side and the right side of the lifting ring (1), and the height of a space surrounded by the reinforcing ribs (5) and the curved surface on the upper part of the lifting ring (1) is equal to the width of the lifting ring (1); the reinforcing ribs (5) can improve the rigidity of the lifting ring (1) and reduce the transverse deformation of the lifting ring (1) in service. The lifting ring (1) can replace the lifting ring structure of the whole dropper of the existing electrified railway or high-speed railway overhead contact system.
Isosceles triangle grooves (6) are machined on the left side and the right side of the lifting ring (1) along the center line, as shown in fig. 1 and 2, the depth of the isosceles triangle grooves (6) is 1/3 of the thickness of the lifting ring (1), the sensor can be guaranteed to be placed in the isosceles triangle grooves (6) and no excessive parts protrude, and the strength of the lifting ring (1) can be not reduced.
The two force sensors (2) and the 1 acceleration sensor (3) are surrounded to form an isosceles triangle, the force sensors (2) are distributed at 60 degrees with the horizontal direction and are triangle waists, and the acceleration sensor (3) is horizontally arranged and is a bottom side. The force sensor (2) and the acceleration sensor (3) are adhered in isosceles triangle grooves (6) on each side of the hanging ring (1) through glue around the isosceles triangle.
The 2 force sensors (2) on each side of the lifting ring (1) test the vertical direction and the horizontal direction of the integral hanger, the acceleration sensor (3) tests the acceleration of the integral hanger under the action of dynamic impact, and the acceleration is converted into the dynamic acting force of the integral hanger through the mass of the integral hanger. During practical testing, the components of the 2 force sensors (2) distributed on each side of the lifting ring (1) in the vertical direction are equal, the components in the horizontal direction are equal in size and opposite in direction, the mounting error can be verified, and the mounting positions of the sensors can be adjusted in time. The sides of the isosceles triangle grooves (6) are parallel to the isosceles triangle sides surrounded by the 2 force sensors (2), so that errors in installation and measurement are reduced.
The force sensor (2) and the acceleration sensor (3) on each side of the lifting ring (1) are connected to the sensor interface (4) through a data transmission line, and then are connected to a computer through the sensor interface (4), so that the dynamic impact force of the whole lifting string is monitored in real time.
The dynamic impact force of the integral hanger is obtained through conversion of a force sensor (2) and an acceleration sensor (3) on each side of the hanging ring (1), and finally, the average value of the dynamic stress is calculated.
The present invention is not limited to the above-mentioned embodiments, and any changes or substitutions that can be easily understood by those skilled in the art within the scope of the present invention are intended to be included in the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.
Claims (2)
1. The utility model provides an integral hanger dynamic impact force measuring device which characterized in that: the device comprises a lifting ring (1), a force sensor (2), an acceleration sensor (3), a sensor interface (4), reinforcing ribs (5) and triangular grooves (6);
The left side and the right side of the lifting ring (1) are symmetrical, and the reinforcing ribs (5) are connected with the left side and the right side of the lifting ring (1); isosceles triangle grooves (6) are machined on the left side and the right side of the lifting ring (1) along the central line, and the depth of each isosceles triangle groove (6) is 1/3 of the thickness of the lifting ring (1);
One side structure of the hanging ring (1) is as follows: the 2 force sensors (2) and the 1 acceleration sensor (3) are surrounded to form an isosceles triangle, the force sensors (2) are distributed at 60 degrees with the horizontal direction and are triangle waists, and the acceleration sensors (3) are horizontally arranged and are bottom edges; the 2 force sensors (2) and the acceleration sensor (3) are adhered in isosceles triangle grooves (6) on each side of the lifting ring (1) around the isosceles triangle;
2 force sensors (2) and acceleration sensors (3) on each side of the lifting ring (1) are connected to a sensor interface (4) through data transmission lines and then connected to a computer through the sensor interface (4);
the surface of the reinforcing rib (5) is a curved surface, the bending radian of the reinforcing rib (5) is 120 degrees, and the height of a space surrounded by the reinforcing rib (5) and the curved surface at the upper part of the lifting ring (1) is equal to the width of the lifting ring (1);
During practical testing, the components of the 2 force sensors (2) distributed on each side of the lifting ring (1) in the vertical direction are equal, the components in the horizontal direction are equal in size and opposite in direction, the mounting error can be verified, and the mounting positions of the sensors can be adjusted in time.
2. A method of using the apparatus of claim 1, wherein:
The components of the 2 force sensors (2) distributed on each side of the lifting ring (1) in the vertical direction are equal, the components in the horizontal direction are equal in size and opposite in direction, the components are used for verifying the mounting error, and the mounting positions of the sensors are adjusted;
2 force sensors (2) on each side of the lifting ring (1) test the stress of the whole lifting string in the vertical direction and the horizontal direction, and an acceleration sensor (3) tests the acceleration of the whole lifting string under the action of dynamic impact; the dynamic impact force of the integral hanger is obtained by converting a force sensor (2) and an acceleration sensor (3) on each side of the hanging ring (1).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810034575.3A CN108287035B (en) | 2018-01-15 | 2018-01-15 | Dynamic impact force measuring device for integral hanger |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810034575.3A CN108287035B (en) | 2018-01-15 | 2018-01-15 | Dynamic impact force measuring device for integral hanger |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108287035A CN108287035A (en) | 2018-07-17 |
| CN108287035B true CN108287035B (en) | 2024-05-17 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201810034575.3A Active CN108287035B (en) | 2018-01-15 | 2018-01-15 | Dynamic impact force measuring device for integral hanger |
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Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN118225369B (en) * | 2024-05-27 | 2024-07-30 | 中铁建电气化局集团轨道交通器材有限公司 | Testing device and testing method for impact load of integral hanger |
Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4328144A1 (en) * | 1993-08-21 | 1995-02-23 | Bosch Gmbh Robert | Device for determining the weight of loads coupled to a tractor |
| RU2233451C2 (en) * | 2002-09-10 | 2004-07-27 | Открытое акционерное общество "Раменское приборостроительное конструкторское бюро" | Compensating accelerometer |
| JP2009030994A (en) * | 2007-07-24 | 2009-02-12 | Yurtec Corp | Shape measurement method for buried concrete foundation, and device thereof |
| CN102052983A (en) * | 2010-12-31 | 2011-05-11 | 朱晓东 | Monitoring device for bow net contact pressure |
| CN202074975U (en) * | 2011-05-25 | 2011-12-14 | 中铁电气化局集团有限公司 | Contact line hanger position measuring instrument |
| CN202631007U (en) * | 2012-06-18 | 2012-12-26 | 绵阳市铁人电气设备有限责任公司 | Dynamic monitoring and analyzing system of high-speed railway contact network based on plurality of platforms |
| CN202900084U (en) * | 2012-09-28 | 2013-04-24 | 蚌埠赛英电子科技发展有限公司 | Beam hanger apparatus capable of detecting load signal |
| CN103884462A (en) * | 2014-03-18 | 2014-06-25 | 中国铁道科学研究院标准计量研究所 | Contact pressure and friction force dynamic detection device |
| CN104260644A (en) * | 2014-09-24 | 2015-01-07 | 中国铁建电气化局集团第二工程有限公司 | Integrated constant-tension hanging string prefabricating platform for overhead line system |
| CN105539204A (en) * | 2016-01-26 | 2016-05-04 | 王旭 | Intelligent high-speed electrified-railway contact network system |
| CN107101821A (en) * | 2017-06-29 | 2017-08-29 | 济南科汇试验设备有限公司 | Dropper fatigue tester |
| CN208026413U (en) * | 2018-01-15 | 2018-10-30 | 中国铁道科学研究院 | Dropper dynamic impulsion force measuring device |
-
2018
- 2018-01-15 CN CN201810034575.3A patent/CN108287035B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4328144A1 (en) * | 1993-08-21 | 1995-02-23 | Bosch Gmbh Robert | Device for determining the weight of loads coupled to a tractor |
| RU2233451C2 (en) * | 2002-09-10 | 2004-07-27 | Открытое акционерное общество "Раменское приборостроительное конструкторское бюро" | Compensating accelerometer |
| JP2009030994A (en) * | 2007-07-24 | 2009-02-12 | Yurtec Corp | Shape measurement method for buried concrete foundation, and device thereof |
| CN102052983A (en) * | 2010-12-31 | 2011-05-11 | 朱晓东 | Monitoring device for bow net contact pressure |
| CN202074975U (en) * | 2011-05-25 | 2011-12-14 | 中铁电气化局集团有限公司 | Contact line hanger position measuring instrument |
| CN202631007U (en) * | 2012-06-18 | 2012-12-26 | 绵阳市铁人电气设备有限责任公司 | Dynamic monitoring and analyzing system of high-speed railway contact network based on plurality of platforms |
| CN202900084U (en) * | 2012-09-28 | 2013-04-24 | 蚌埠赛英电子科技发展有限公司 | Beam hanger apparatus capable of detecting load signal |
| CN103884462A (en) * | 2014-03-18 | 2014-06-25 | 中国铁道科学研究院标准计量研究所 | Contact pressure and friction force dynamic detection device |
| CN104260644A (en) * | 2014-09-24 | 2015-01-07 | 中国铁建电气化局集团第二工程有限公司 | Integrated constant-tension hanging string prefabricating platform for overhead line system |
| CN105539204A (en) * | 2016-01-26 | 2016-05-04 | 王旭 | Intelligent high-speed electrified-railway contact network system |
| CN107101821A (en) * | 2017-06-29 | 2017-08-29 | 济南科汇试验设备有限公司 | Dropper fatigue tester |
| CN208026413U (en) * | 2018-01-15 | 2018-10-30 | 中国铁道科学研究院 | Dropper dynamic impulsion force measuring device |
Non-Patent Citations (1)
| Title |
|---|
| 高铁接触网吊弦疲劳特性研究;王伟;CNKI优秀硕士学位论文全文库 工程科技II辑(第9期);37-38 * |
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| CN108287035A (en) | 2018-07-17 |
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Address after: No. 2, Da Liu Shu Road, Haidian District, Beijing Applicant after: CHINA ACADEMY OF RAILWAY SCIENCES Corp.,Ltd. Applicant after: CHINA RAILWAY TEST & CERTIFICATION CENTER Applicant after: STANDARDS & METROLOGY Research Institute CHINA ACADEMY OF RAILWAY SCIENCES Address before: No. 2, Da Liu Shu Road, Haidian District, Beijing Applicant before: China Academy of Railway Sciences Applicant before: CHINA RAILWAY TEST & CERTIFICATION CENTER Applicant before: STANDARDS & METROLOGY Research Institute CHINA ACADEMY OF RAILWAY SCIENCES |
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Effective date of registration: 20181205 Address after: 100038 No. 10 Fuxing Road, Haidian District, Beijing Applicant after: CHINA RAILWAY Corp. Applicant after: CHINA ACADEMY OF RAILWAY SCIENCES Corp.,Ltd. Applicant after: CHINA RAILWAY TEST & CERTIFICATION CENTER Applicant after: STANDARDS & METROLOGY Research Institute CHINA ACADEMY OF RAILWAY SCIENCES Address before: No. 2, Da Liu Shu Road, Haidian District, Beijing Applicant before: CHINA ACADEMY OF RAILWAY SCIENCES Corp.,Ltd. Applicant before: CHINA RAILWAY TEST & CERTIFICATION CENTER Applicant before: STANDARDS & METROLOGY Research Institute CHINA ACADEMY OF RAILWAY SCIENCES |
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