CN103245562B - Gravity constant-pressure electro-hydraulic servo loading system - Google Patents
Gravity constant-pressure electro-hydraulic servo loading system Download PDFInfo
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- CN103245562B CN103245562B CN201310144417.0A CN201310144417A CN103245562B CN 103245562 B CN103245562 B CN 103245562B CN 201310144417 A CN201310144417 A CN 201310144417A CN 103245562 B CN103245562 B CN 103245562B
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Abstract
The invention discloses a gravity constant-pressure electro-hydraulic servo loading system comprising a gravity amplifying and constant-pressure device and an electro-hydraulic servo loading module, wherein the gravity amplifying and constant-pressure device comprises a gear-chain wheel combining device, a chain, a weight, a rack and a guide rail; the chain is sleeved on the chain wheel and is closed to be annular end to end; the weight is hung at one point of the annular chain; and the rack is located inside the horizontal guide rail, is engaged with gears and is connected with a constant-pressure source oil cylinder with a piston push rod. If the mass of the weight, the magnification factor of a gear set and the area of a piston are unchanged, oil pressure in the constant-pressure source oil cylinder keeps unchanged. Therefore, loads acting on a test piece by loading oil paths and a loading oil cylinder keep constant. When a hydraulic pump needs to supply liquid to the oil paths because the test piece excessively deforms, the liquid supply pressure is required to be slightly higher than the pressure in the constant-pressure source oil cylinder before liquid supplying, so that the piston is pushed to the left side of the oil cylinder. Therefore, the pressure stabilization is realized through a high-precision overflow valve and a constant-value pressure reducing valve in the loading oil paths.
Description
Technical field
The present invention relates to a kind of test loading technique, particularly relate to a kind of gravity constant voltage Based on Electro-hydraulic Loading Servo System.
Background technology
In existing test loading technique, load for test specimen provides the load mode of constant load to comprise electro-hydraulic servo control loading, gravitational load and vacuum tank.Electro-hydraulic servo control load mode can provide larger load and have higher control accuracy, but also there is following problem: (1) system complex and need continue supply of electric power, buy and operating cost high; (2) hydraulic part frequent movement, easily causes hydraulic oil to heat up and component wear and control accuracy is declined; (3) in test piece deformation process, the load acted on test specimen is in the fluctuation status of dynamic conditioning all the time, cannot provide constant load truly.
It is after-applied to test specimen that existing gravitational load mode mainly carries out amplification by the component such as lever, pulley to gravity.Once test specimen deforms, lever is just no longer in level, and its load multiplication factor also just changes, and thus cannot keep constant load.The gravity hydraulic dead load energy storage equipment provided in Chinese patent: 200810247353.6---gravity hydraulic dead load energy storage equipment and true triaxial creep test system overcomes the shortcoming of lever-loading, but also there is following shortcoming: be subject to article carrying platform size to limit its pressure provided very limited.Cause between piston and cylinder body, producing larger frictional resistance if weight places asymmetric meeting; Make it go back up to highest point when cylinder body drops to bottom by the mode of hand pump fluid infusion and must cause pressure oscillation, and plunger shaft volume is little, the test piece deformation that cylinder body one stroke can compensate is very little, and the test piece deformation really providing constant load to adapt to is also just very little; The mode of hand pump controlled loading requires to have special messenger to be responsible for keeping an eye on, and not only takies personnel but also be unsuitable for long-time test.
It is the load being provided approximately constant by high pressure gas holder cooperation oil pump to test specimen that vacuum tank loads, and its principle of stabilized voltage is when the oil pressure in vacuum tank supplements oil sources until pressure goes back up to initial value lower than starting oil pump during setting value in vacuum tank.It can thus be appreciated that the load that this load mode provides is inevitable constantly to fluctuate within the specific limits along with test piece deformation.
In sum, existing loading technique all really can not realize long constant voltage and load, and can not adapt to the dead load demand in test specimen large deformation process.
Summary of the invention
Goal of the invention: for above-mentioned loading system Problems existing, designs a kind of gravity constant voltage Based on Electro-hydraulic Loading Servo System, meets the constant load requirement in test specimen moderate finite deformation process, realize unattended constant voltage and automatically control.
Technical scheme: gravity constant voltage Based on Electro-hydraulic Loading Servo System, comprises gravity and amplifies and constant-voltage equipment, electro-hydraulic loading module; Wherein:
Described gravity amplifies and constant-voltage equipment comprises gear-chain wheel set locking device, counterweight 1, head and the tail are closed into ring-type chain 2, tooth bar 9, horizontal guide rail 10; Wherein, described gear-chain wheel set locking device comprises sprocket wheel 3, gear, and described chain 2 is enclosed within sprocket wheel 3, tooth bar 9 be positioned at horizontal guide rail 10 and and gears meshing; Described tooth bar 9 can slide along horizontal guide rail 10; Described counterweight 1 be hung on annular link chain 2 a bit;
Described electro-hydraulic loading module comprises oil circuit and circuit; Wherein:
Described oil circuit comprises the working connection, the first loading oil circuit be connected with the first load cylinder 12, the second loading oil circuit be connected with the second load cylinder 13, the 3rd loading oil circuit that is connected with the 3rd load cylinder 14 that are connected with the constant pressure source oil cylinder 11 of band push-rod piston; The check valve 21 that described oil circuit also comprises the hydraulic pump 20 away from load cylinder one end being connected to working connection, the first pilot operated compound relief valve 22 connecting described constant pressure source oil cylinder 11 output and is connected between the output of described hydraulic pump 20 and the first pilot operated compound relief valve 22; Described first loading oil circuit also comprises and connects the first pilot-operated type fixed pressure reducing valve 26 of loading oil circuit and the second pilot operated compound relief valve 23 between described first pilot-operated type fixed pressure reducing valve 26 and the first load cylinder 12; Described second loading oil circuit also comprises and connects the second pilot-operated type fixed pressure reducing valve 27 of loading oil circuit and the 3rd pilot operated compound relief valve 24 between described second pilot-operated type fixed pressure reducing valve 27 and the second load cylinder 13; Described 3rd loading oil circuit also comprises and connects the 3rd pilot-operated type fixed pressure reducing valve 28 of loading oil circuit and the 4th pilot operated compound relief valve 25 between described 3rd pilot-operated type fixed pressure reducing valve 28 and the 3rd load cylinder 14; The piston push rod of described constant pressure source oil cylinder 11 is connected near one end of constant pressure source oil cylinder 11 with described tooth bar 9;
Described circuit comprises the antennule 15, the antenna secunda 16 that lay respectively at described tooth bar 9 two ends and is connected in series and forms the switch 17 in loop, power supply 18 and motor 19; Described motor 19 connects described hydraulic pump 20; Described antennule 15 and antenna secunda 16 control the disconnection of described switch 17 and close.
Wherein, described gear-chain wheel set locking device comprises sprocket wheel 3, first to the 5th gear 4 ~ 8; The diameter of sprocket wheel 3 is greater than the diameter of the first gear 4 and coaxially installs with the first gear 4; The diameter of the second gear 5 is greater than the diameter of the first gear 4 and engages with the first gear 4; The diameter of the 3rd gear 6 is less than the diameter of the second gear 5 and coaxially installs with the second gear 5; The diameter of the 4th gear 7 is greater than the diameter of the 3rd gear 6 and engages with the 3rd gear 6; The diameter of the 5th gear 8 is less than the diameter of the 4th gear 7 and coaxially installs with the 4th gear 7; Described 5th gear 8 engages with described tooth bar 9.
Beneficial effect:
(1) the load scope provided is large: can export little of several kilograms of large loads arriving several tons to the piston of constant pressure source oil cylinder 11 by the weight of the multiplication factor between change gear and counterweight 1, the load scope acted on after oil circuit transmission on test specimen is large, can meet the demand that overwhelming majority test loads.
(2) constant voltage performance is good: adopt the closed chain of head and the tail to ensure that the tangential force putting on sprocket wheel is always the gravity of counterweight, avoid stress fluctuation; The load suffered in moderate finite deformation process of test specimen keeps real constant to adopt the constant pressure source oil cylinder 11 of larger volume to ensure; Even if supplement in the process of oil sources at hydraulic pump 20 to oil circuit, also the constant of on-load pressure can be kept by the control of the high-precision first to the 3rd pilot-operated type fixed pressure reducing valve 26 ~ 28 and first to fourth pilot operated compound relief valve 22 ~ 25.
(3) automation with voltage stabilizing is loaded: along with the compression of test specimen, the piston that tooth bar 9 promotes constant pressure source oil cylinder 11 is turned right motion, when piston close to the haptic element 15 on oil cylinder 11 extreme right position hour rack 9 by open circuit switch 17, motor 19 is started and drive hydraulic pump 20 in oil circuit supplement oil sources.Because the setting pressure of the first pilot operated compound relief valve 22 is slightly larger than gravity constant voltage value, the piston of oil cylinder 11 is promoted toward left movement while hydraulic pump 20 supplements oil sources toward oil circuit, when piston close to the haptic element 16 on left end extreme position hour rack 9 by shut-off circuit switch 17, thus make system be returned to gravity pressure constant state.
(4) system substantially by ready-made machinery, electrically and Hydraulic Elements form, structure is simple, builds convenient and low cost; System does not need the continuous running of motor, and use cost is low; Pressure change frequencies in working connection is low, is conducive to working reliably and with long-term of Hydraulic Elements in loading oil circuit.
Accompanying drawing explanation
Fig. 1 is gravity constant voltage Based on Electro-hydraulic Loading Servo System structure chart;
Fig. 2 is that gravity amplifies and constant-voltage equipment three-view diagram.
Each label declaration in figure: 1 counterweight; 2 chains; 3 sprocket wheels; 4 first gears; 5 second gears; 6 the 3rd gears; 7 the 4th gears; 8 the 5th gears; 9 tooth bars; 10 guide rails; 11 constant pressure source oil cylinders; 12 ~ 14 first to the 3rd load cylinder; 15,16 the first to the second haptic elements; 17 contactors; 18 power supplys; 19 motor; 20 hydraulic pumps; 21 check valves; 22 ~ 25 first to fourth pilot operated compound relief valves; 26 ~ 28 first to the 3rd pilot-operated type fixed pressure reducing valve; 29 Pressure gauges.
Detailed description of the invention:
Below in conjunction with accompanying drawing the present invention done and further explain.
Gravity constant voltage Based on Electro-hydraulic Loading Servo System, comprises gravity and amplifies and constant-voltage equipment, electro-hydraulic loading module; Wherein:
Gravity amplifies and constant-voltage equipment comprises gear-chain wheel set locking device, counterweight 1, chain 2, tooth bar 9, horizontal guide rail 10.Wherein, gear-chain wheel set locking device comprises sprocket wheel 3, gear, and described chain 2 is enclosed within sprocket wheel 3, and tooth bar 9 is positioned at horizontal guide rail 10 and and gears meshing.Tooth bar 9 can slide along horizontal guide rail 10, counterweight 1 be hung on annular link chain 2 a bit.Wherein, gear-chain wheel set locking device comprises sprocket wheel 3, first gear 4, second gear 5, the 3rd gear 6, the 4th gear 7, the 5th gear 8; The diameter of sprocket wheel 3 is greater than the diameter of the first gear 4 and coaxially installs with the first gear 4; The diameter of the second gear 5 is greater than the diameter of the first gear 4 and engages with the first gear 4; The diameter of the 3rd gear 6 is less than the diameter of the second gear 5 and coaxially installs with the second gear 5; The diameter of the 4th gear 7 is greater than the diameter of the 3rd gear 6 and engages with the 3rd gear 6; The diameter of the 5th gear 8 is less than the diameter of the 4th gear 7 and coaxially installs with the 4th gear 7; Described 5th gear 8 engages with described tooth bar 9.
If the weight of counterweight 1 is G, sprocket wheel 3 is k with the radius ratio of gear 4
1, then gear 4 acts on the tangential force of gear 5 is G × k
1; In like manner, gear 5 is k with the radius ratio of gear 6
2, then gear 6 acts on the tangential force of gear 7 is G × k
1× k
2; Gear 7 is k with the radius ratio of gear 8
3, then gear 8 acts on the tangential force of tooth bar 9 is G × k
1× k
2× k
3.As can be seen here, counterweight weight exports load and is increased to original (k after illustrating the amplification of gear train
1× k
2× k
3) doubly, this load through the piston action of constant pressure source oil cylinder in hydraulic oil.If the cross-sectional area of piston is S, then the oil pressure in oil cylinder is (k
1× k
2× k
3) × G/S.
Electro-hydraulic loading module comprises oil circuit and circuit.Wherein: oil circuit comprises the working connection, the first loading oil circuit be connected with the first load cylinder 12, the second loading oil circuit be connected with the second load cylinder 13, the 3rd loading oil circuit that is connected with the 3rd load cylinder 14 that are connected with the constant pressure source oil cylinder 11 of band push-rod piston.Oil circuit also comprises and is connected to working connection away from the hydraulic pump 20 of load cylinder one end, the first pilot operated compound relief valve 22 connecting constant pressure source oil cylinder 11 output and the check valve 21 be connected between the output of hydraulic pump 20 and the first pilot operated compound relief valve 22.First loading oil circuit also comprises and connects the first pilot-operated type fixed pressure reducing valve 26 of loading oil circuit and the second pilot operated compound relief valve 23 between the first pilot-operated type fixed pressure reducing valve 26 and the first load cylinder 12.Second loading oil circuit also comprises and connects the second pilot-operated type fixed pressure reducing valve 27 of loading oil circuit and the 3rd pilot operated compound relief valve 24 between the second pilot-operated type fixed pressure reducing valve 27 and the second load cylinder 13.3rd loading oil circuit also comprises and connects the 3rd pilot-operated type fixed pressure reducing valve 28 of loading oil circuit and the 4th pilot operated compound relief valve 25 between the 3rd pilot-operated type fixed pressure reducing valve 28 and the 3rd load cylinder 14.The piston push rod of constant pressure source oil cylinder 11 is connected with tooth bar 9 one end near constant pressure source oil cylinder 11.The output of constant pressure source oil cylinder 11 and the loading oil circuit setting pressure table respectively near the first to the 3rd load cylinder 12 ~ 14, for detecting the pressure of working connection and each loading oil circuit.
Because the acceleration of gravity in place a certain on the earth is constant, as long as counterbalance mass, gear train multiplication factor and piston area are constant, oil pressure in constant pressure source oil cylinder 11 just remains unchanged, and the load thus acted on test specimen through each loading oil circuit and load cylinder also just keeps constant.Excessive deformation is produced for test specimen and needs hydraulic pump 20 toward the situation of oil circuit fluid infusion, require that fluid infusion pressure is a little more than the pressure in constant pressure source oil cylinder 11 before fluid infusion, so that be pushed into by piston on the left of oil cylinder 11, now mainly rely on first to fourth high-precision pilot-operated type degree overflow valve 22 ~ 25 and the first to the 3rd fixed pressure reducing valve 26 ~ 28 pressure stabilization functions in loading oil circuit.In loading oil circuit, pressure-reducing valve must be contained in overflow valve leftward position, and that is hydraulic oil must first flow through pressure-reducing valve and then just connects overflow valve.Object is the oil sources first being provided setting pressure by pressure-reducing valve to load cylinder, is then prevented because the reasons such as swelling of the pattern distortion make the oil pressure of load cylinder exceed setting pressure by overflow valve.
Circuit comprises the antennule 15, the antenna secunda 16 that lay respectively at tooth bar 9 two ends and is connected in series and forms the switch 17 in loop, power supply 18 and motor 19.Motor 19 connects described hydraulic pump 20, the disconnection of antennule 15 and antenna secunda 16 gauge tap 17 and closed.
If the hydraulic oil in constant pressure source oil cylinder 11 is not enough to compensate the excessive compression of test specimen, then need in time to replenisher force feed in oil circuit.When the tooth bar piston promoted in constant pressure source oil cylinder 11 with haptic element 15 and 16 runs to the extreme position close to oil cylinder 11 right-hand member, haptic element 15 will open circuit switch 17, makes the circuit turn-on of motor 19, then drives hydraulic pump 20 toward oiling in oil circuit.Arrange pressure a little more than the constant pressure before fluid infusion due to overflow valve 22, a supplementary hydraulic oil part continues to provide constant load to test specimen by the fixed pressure reducing valve 23 ~ 25 of loading oil circuit and overflow valve 26 ~ 28, and another part pushing tow piston is toward left movement.When piston runs to the extreme position close to oil cylinder 11 left end, haptic element 16 is shut-off circuit switch immediately, cuts off the power supply of motor 19, thus stops repairing.
The gravity constant voltage Based on Electro-hydraulic Loading Servo System course of work of the present invention is as follows:
(1) preparation: the weight of the maximum load calculation of pressure counterweight 1 needed for the multiplication factor of gear train, the piston cross-section area of constant pressure source oil cylinder 11 and test.Oil-filled with the air got rid of in oil cylinder, pipeline and various Hydraulic Elements to oil circuit by hydraulic pump 20, make the piston of constant pressure source oil cylinder 11 be in left position.Regulate the first pilot operated compound relief valve 22 to make its opening pressure a little more than the maximum load pressure of design, set the force value of corresponding overflow valve 26 ~ 28 and fixed pressure reducing valve 23 ~ 25 according to the design pressure of each loading oil circuit.
(2) original upload: the counterweight 1 of approrpiate wts is hung on chain 2 upper end near the position of sprocket wheel 3, is acted on the piston of constant pressure source oil cylinder 11, puts on surface of test piece by each loading oil circuit and load cylinder 12 after gear train amplifies by tooth bar 9.Concrete loading procedure both can adopt the method for once hanging total weight counterweight to realize once loading fast, the mode injecting liquid or fine sand gradually in empty well-bucket also can be adopted to realize hierarchical loading, and loading velocity was controlled.
(3) electro-hydraulic servo constant voltage loads: the piston of constant pressure source oil cylinder 11 to be turned right motion along with the compression of test specimen, when extreme position close to oil cylinder right-hand member, haptic element 15 is by open circuit switch 17, motor 19 is made to drive hydraulic pump 20 toward oiling in oil circuit, ensure on the one hand to provide lasting constant load to test specimen, pushing tow piston is toward left movement on the other hand.When the extreme position of piston close to oil cylinder left end, haptic element 16 shut-off circuit switch, stops repairing.This process constantly repeats until tested.
The above is only the preferred embodiment of the present invention; it should be pointed out that for those skilled in the art, under the premise without departing from the principles of the invention; can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.
Claims (2)
1. gravity constant voltage Based on Electro-hydraulic Loading Servo System, is characterized in that: comprise gravity and amplify and constant-voltage equipment, electro-hydraulic loading module; Wherein:
Described gravity amplifies and constant-voltage equipment comprises gear-chain wheel set locking device, counterweight (1), head and the tail are closed into ring-type chain (2), tooth bar (9), horizontal guide rail (10); Wherein, described gear-chain wheel set locking device comprises sprocket wheel (3), gear, and described chain (2) is enclosed within sprocket wheel (3), tooth bar (9) be positioned at horizontal guide rail (10) and and gears meshing; Described tooth bar (9) can slide along horizontal guide rail (10); Described counterweight (1) be hung on annular link chain (2) a bit;
Described electro-hydraulic loading module comprises oil circuit and circuit; Wherein:
Described oil circuit comprises the working connection, the first loading oil circuit be connected with the first load cylinder (12), the second loading oil circuit be connected with the second load cylinder (13), the 3rd loading oil circuit that is connected with the 3rd load cylinder (14) that are connected with the constant pressure source oil cylinder (11) of band push-rod piston; The check valve (21) that described oil circuit also comprises the hydraulic pump away from load cylinder one end (20) being connected to working connection, the first pilot operated compound relief valve (22) connecting described constant pressure source oil cylinder (11) output and is connected between the output of described hydraulic pump (20) and the first pilot operated compound relief valve (22); Described first loading oil circuit also comprises the first pilot-operated type fixed pressure reducing valve (26) connecting loading oil circuit and the second pilot operated compound relief valve (23) be positioned between described first pilot-operated type fixed pressure reducing valve (26) and the first load cylinder (12); Described second loading oil circuit also comprises the second pilot-operated type fixed pressure reducing valve (27) connecting loading oil circuit and the 3rd pilot operated compound relief valve (24) be positioned between described second pilot-operated type fixed pressure reducing valve (27) and the second load cylinder (13); Described 3rd loading oil circuit also comprises the 3rd pilot-operated type fixed pressure reducing valve (28) connecting loading oil circuit and the 4th pilot operated compound relief valve (25) be positioned between described 3rd pilot-operated type fixed pressure reducing valve (28) and the 3rd load cylinder (14); The piston push rod of described constant pressure source oil cylinder (11) is connected with described tooth bar (9) one end near constant pressure source oil cylinder (11);
Described circuit comprises the antennule (15), the antenna secunda (16) that lay respectively at described tooth bar (9) two ends and is connected in series and forms the switch (17) in loop, power supply (18) and motor (19); Described motor (19) connects described hydraulic pump (20); Described antennule (15) and antenna secunda (16) control the disconnection of described switch (17) and close.
2. gravity constant voltage Based on Electro-hydraulic Loading Servo System according to claim 1, is characterized in that: described gear-chain wheel set locking device comprises sprocket wheel (3), the first to the 5th gear (4 ~ 8); The diameter of sprocket wheel (3) is greater than the diameter of the first gear (4) and coaxially installs with the first gear (4); The diameter of the second gear (5) is greater than the diameter of the first gear (4) and engages with the first gear (4); The diameter of the 3rd gear (6) is less than the diameter of the second gear (5) and coaxially installs with the second gear (5); The diameter of the 4th gear (7) is greater than the diameter of the 3rd gear (6) and engages with the 3rd gear (6); The diameter of the 5th gear (8) is less than the diameter of the 4th gear (7) and coaxially installs with the 4th gear (7); Described 5th gear (8) engages with described tooth bar (9).
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310144417.0A CN103245562B (en) | 2013-04-23 | 2013-04-23 | Gravity constant-pressure electro-hydraulic servo loading system |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310144417.0A CN103245562B (en) | 2013-04-23 | 2013-04-23 | Gravity constant-pressure electro-hydraulic servo loading system |
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| CN103245562A CN103245562A (en) | 2013-08-14 |
| CN103245562B true CN103245562B (en) | 2015-03-25 |
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| CN201310144417.0A Expired - Fee Related CN103245562B (en) | 2013-04-23 | 2013-04-23 | Gravity constant-pressure electro-hydraulic servo loading system |
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| CN106153520B (en) * | 2016-08-10 | 2020-04-07 | 山东科技大学 | Ultrafiltration test device for undisturbed clay |
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| CN101221163A (en) * | 2008-02-02 | 2008-07-16 | 中国矿业大学(北京) | Rock rheometer gravity load force expanding method and mechanism |
| CN101493388A (en) * | 2008-12-30 | 2009-07-29 | 中国矿业大学(北京) | Gravity hydraulic dead load energy-saving equipment and true triaxial creep experiment system |
| CN201488920U (en) * | 2009-09-22 | 2010-05-26 | 北京英斯派克科技有限公司 | Accurate constant-pressure hydraulic system |
| CN201716239U (en) * | 2010-06-13 | 2011-01-19 | 中国矿业大学 | Gravitational load test apparatus |
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| JPH07155999A (en) * | 1993-09-02 | 1995-06-20 | Maschinenfabrik Mueller Weingarten Ag | Method and device for controlling driving of hydraulic press |
| JP2003013907A (en) * | 2001-06-27 | 2003-01-15 | Yuichi Kiryu | Electro-hydraulic actuator for compression molding machine, injection molding machine or the like |
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2013
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|---|---|---|---|---|
| CN101221163A (en) * | 2008-02-02 | 2008-07-16 | 中国矿业大学(北京) | Rock rheometer gravity load force expanding method and mechanism |
| CN101493388A (en) * | 2008-12-30 | 2009-07-29 | 中国矿业大学(北京) | Gravity hydraulic dead load energy-saving equipment and true triaxial creep experiment system |
| CN201488920U (en) * | 2009-09-22 | 2010-05-26 | 北京英斯派克科技有限公司 | Accurate constant-pressure hydraulic system |
| CN201716239U (en) * | 2010-06-13 | 2011-01-19 | 中国矿业大学 | Gravitational load test apparatus |
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