Linear acceleration and impact testing machine
Technical field
The present invention relates to a kind of linear acceleration and impact test apparatus, be specifically related to a kind ofly to be used to examine that evaluation is airborne, missile-borne, vehicle-mounted, on-board equipment be to the adaptability of linear acceleration and shock environment and to the test of occupant's security.
Background technology
In the prior art, the acceleration test machine has centrifugal acceleration test machine and rocket to prize two kinds in acceleration test machine at present.Wherein, with the most use is centrifugal acceleration test machine, and this testing machine can only carry out acceleration test to the little test specimen of volume.And this testing machine is owing to adopt centrifugal acceleration in test to test specimen power supply, gas, liquid and how slotted line is drawn all relatively difficulty, and carries out acceleration test with this equipment and have the errors of principles (Corioli's acceleration) and test error (physical dimension of test product).Another kind is the acceleration test machine, rocket sled acceleration test machine can carry out the linear acceleration test, its principle is to utilize the thrust of rocket to promote coaster to do straight line accelerated motion on the guide rail of several kms even tens kms, sample is carried out acceleration test, but, therefore can not popularize because this testing machine cost and running expense are extremely expensive.And in the practice, examination evaluation is airborne, missile-borne, vehicle-mounted, on-board equipment be to the adaptability of linear acceleration, shock environment and very important to the test of occupant's security, and therefore how designing a kind of economical and practical type linear acceleration testing machine simple in structure, that cost is low is the problem that those skilled in the art very pay close attention to for many years.
Summary of the invention
The purpose of this invention is to provide and a kind ofly take into account the testing machine of impact as the economical and practical type horizontal linear acceleration of carrier, to substitute the extremely expensive rocket sled acceleration test machine of existing cost with guide tracked dolly.
For achieving the above object, the technical solution used in the present invention is: a kind of linear acceleration and impact testing machine, comprise horizontal linear track and instruction carriage, instruction carriage drops on the track by roller mount, formation is along the instruction carriage structure of horizontal linear orbital motion, the front end of instruction carriage is connected with a kind of stretch cord, and the other end of stretch cord is fixed on the fixture in instruction carriage the place ahead; The rear end of instruction carriage is connected with a kind of traction rope and a kind of braking rope, the other end of traction rope is connected on winch or the haulage gear, an electromagnetic clutch of serial connection and a tension indicator in the middle of the traction rope, the other end of braking rope is connected on a kind of brake gear.
Related content in the technique scheme is explained as follows:
1, design of the present invention and principle of work
(the national electric and electronic product Environmental Technology standardization council writes according to " environmental baseline and experimental enviroment test application guide ", China Standard Press publishes), chapter 10, impact, the impact test effect principle, when the duration, the relative test specimen single order natural period, length was more than five times, its shock effect was with regard to the effect of equivalent acceleration test.Use this equivalence principle,, replace several kms with several meters long tracks for the horizontal impact test that can popularize a linear acceleration and long duration creates conditions, even the track of tens kms, rocket engine replaced with stretch cord (such as elastic string) energy storage method.Employing system internal force becomes outer force method, and with winch or haulage gear pulling test car tensile-elasticity rope, the tension indicator on traction rope meets the requirements of F
mDuring pulling force, remain unchanged, unclamp electromagnetic clutch more suddenly, stretch cord acts on instruction carriage, and instruction carriage is pressed F
m=m
mA (disregarding friction force) produces straight line accelerated motion.This linear acceleration reduces and reduces along with elastic deformation, because Deformation control is in K constant scope, so the relation of pulling force and distortion is linear.Adjust braking force according to the size of backward acceleration then, stop in orbit until instruction carriage.This process has realized the acceleration test of an axial positive and negative both direction.
When carrying out the acceleration test of above-mentioned positive and negative both direction, instruction carriage orbits, and test specimen is fixed on the instruction carriage, when traction rope is unclamped by electromagnetic clutch suddenly:
F
m=m
m·a
In the formula: F
m---the maximum pull that stretch cord stores;
m
m---the quality of the quality+test specimen of instruction carriage;
The acceleration of a---testing requirements.
Momentum
F=K·ΔL
In the formula: S---momentum;
The rigidity of K---stretch cord is calculated by a that requires and m;
The tensile elongation of Δ L---stretch cord is by a and D
0Calculate, wherein D
0Be shock duration, be generally 0.20 second.
2, in order effectively to carry out the test of positive and negative linear acceleration and shock environment, brake gear described in the such scheme comprises following three kinds of versions:
(1), constitutes brake gear by friction disc mechanism.This brake gear adopts brake block to realize such as automotive brake, for another example similar friction catch mechanism etc.
(2), promote balance weight mechanism by one and constitute brake gear.Such as connecting a brake cable at the instruction carriage afterbody, when instruction carriage when positive acceleration moves, this cable wire loosens, but the cable wire that acquires a certain degree strains suddenly, and promotes a weight work done, thereby reaches braking effect.
(3), constitute brake gear by the hydraulic cylinder arrestment mechanism.Such as when instruction carriage after positive acceleration moves to certain speed, drive a hydraulic cylinder suddenly, play braking action.
Also can adopt the energy absorber of other form to be used as the brake gear of instruction carriage.
3, the present invention is when carrying out the shock environment test, when needs obtain the duration of bigger peak accelerator and weak point, it is not enough only relying on above technical scheme, in other words, above technical scheme can only realize the shock environment test of less peak accelerator and long period, if obtain bigger peak accelerator and short duration, need increase the jigger of another quality on this basis less than instruction carriage, utilize barycenter head-on collision principle to realize, following situation, m promptly appear when bumping
1a
1=m
2a
2, if m
1>>m
2A then
2>>a
1Specifically can adopt following two kinds of structures:
(1), on the such scheme basis, when carrying out the test of big peak accelerator, also pull the jigger of a quality less than instruction carriage at the rear portion of instruction carriage, jigger drops on the track by roller mount, and the head of jigger is provided with relative impingement area with the afterbody of instruction carriage.
(2), on the such scheme basis, on instruction carriage, be provided with the jigger of a quality less than instruction carriage, jigger and instruction carriage are slidingly connected on parallel, horizontal rectilinear orbit direction, are connected by elastic buffer on the one hand between instruction carriage and the jigger, are oppositely arranged impingement area on the other hand.
4, the present invention carries out rectilinear motion reliably for warranty test car or jigger on the horizontal linear track, especially after producing impact, barycenter is higher not to topple yet, and the rolling design between its track and instruction carriage or the jigger can be adopted following scheme:
(1), the horizontal linear track can be made of two guide rails or single-rail structure.
(2), the xsect of guide rail is " worker " font, following traverse rod body is fixed on the base of the rail, last traverse rod body is as track, instruction carriage or jigger are in same xsect, end face setting or two rollers at track, every side in the two sides of track is provided with angle sheave, and the every side in the both sides, bottom surface of track is provided with the anti-wheel that topples.
5, as can be known, the present invention is a kind of linear acceleration testing machine, and this testing machine also has the impulse test function, and can also carry out the high acceleration test by collision from above content.
Because the technique scheme utilization, the present invention compared with prior art has following advantage and effect:
1, the present invention has remedied existing centrifugal acceleration test machine and can not carry out large volume, the linear acceleration of high barycenter product, shock environment test.Overcome centrifugal acceleration in test to test specimen power supply, gas, liquid and the defective of drawing the slotted line difficulty.
2, the present invention compares with rocket sled acceleration test machine, the guide rail that has not only replaced several kms even tens kms with several meters long guide rail, and having replaced rocket engine with stretch cord energy storage method, its cost reduces greatly, can reach the degree that penetration and promotion is used.
3, the present invention has overcome the difficult impact that realizes greater than the 3m/s velocity variable of common shock testing machine.
4, the present invention is simple in structure, but function is stronger, can not only be used for carrying out positive and negative acceleration test, but also can be used for carrying out various peak accelerators, the impulse test of various durations sawtooth wave.
5, there be not the errors of principles and the physical dimension error of centrifugal acceleration test machine in the present invention.
Description of drawings
Accompanying drawing 1 is structural representation of the present invention;
Accompanying drawing 2 is principle of the invention figure (one), winch or haulage gear pulling test car tensile-elasticity rope energy storage state;
Accompanying drawing 3 is principle of the invention figure (two), and instruction carriage carries out positive acceleration (impact) trystate under the effect of stretch cord pulling force;
Accompanying drawing 4 is principle of the invention figure (three), and instruction carriage carries out backward acceleration (impact) trystate under stretch cord pulling force and brake gear act on simultaneously;
Accompanying drawing 5 is principle of the invention figure (four), and instruction carriage and jigger utilize barycenter head-on collision principle to produce big peak accelerator, the impulse test state of short duration;
Accompanying drawing 6 is the rolling project organization synoptic diagram (sectional view) between instruction carriage of the present invention or jigger and the guide rail.
In the above accompanying drawing, 1, roller; 2, the anti-wheel that topples; 3, angle sheave; 4, instruction carriage base plate; 5, wheel pedestal; 6, guide rail; 7, instruction carriage; 8, stretch cord; 9, traction rope; 10, electromagnetic clutch; 11, tension indicator; 12, winch or haulage gear; 13, braking rope; 14, brake gear; 15, following traverse rod body; 16, the base of the rail; 17, go up the traverse rod body; 18, jigger; 19, elastic buffer.
Embodiment
Below in conjunction with drawings and Examples the present invention is further described:
Embodiment one: referring to shown in Figure 1, a kind of linear acceleration and impact testing machine are made up of horizontal linear track, instruction carriage 7, stretch cord 8, traction rope 9, electromagnetic clutch 10, tension indicator 11, winch or haulage gear 12, braking rope 13 and brake gear 14.
Instruction carriage 7 is located in orbit by a kind of anti-guide roller structure of toppling.Track is made of the horizontal guide rail 6 of two parallel tilings.The anti-guide roller structure of toppling is seen shown in Figure 6, and the xsect of guide rail 6 is " worker " font, and following traverse rod body 15 is fixed on the base of the rail 16, and last traverse rod body 17 is as track.Instruction carriage 7 is provided with two rollers 1 at the end face of track in same xsect, in the two sides of track an angle sheave 3 is set respectively, and an anti-wheel 2 that topples is set respectively in the both sides, bottom surface of track.Two rollers 1 roll and are installed on the instruction carriage base plate 4, and two rollers 1 roll with the end face of track and contact.Two angle sheaves 3 and two anti-wheels 2 that topple roll and are installed on the wheel pedestal 5, and wherein, two angle sheaves 3 roll with two sides of track and contact, and two anti-wheels 2 that topple contact with track bottom surface two side rolls respectively.Wheel pedestal 5 is fixed on the instruction carriage base plate 4, constitutes instruction carriage structure along the horizontal linear orbital motion with this.
The front end of instruction carriage 7 is connected with one stretch cord 8, and the other end of stretch cord 8 is fixed on the fixture in instruction carriage 7 the place aheads.The rear end of instruction carriage 7 is connected with one or more strands of traction ropes 9 and one or more strands of braking rope 13.The other end of traction rope 9 is connected on winch or the haulage gear 12, an electromagnetic clutch 10 of serial connection and a tension indicator 11 in the middle of the traction rope 9.The other end of braking rope 13 is connected on a kind of brake gear 14.
Brake gear 14 can be one of following three kinds of versions:
(1), constitutes brake gear 14 by friction disc mechanism.This brake gear 14 adopts brake block to realize such as automotive brake, for another example similar friction catch mechanism etc.
(2), promote balance weight mechanism by one and constitute brake gear 14.Such as connecting a brake cable at the instruction carriage afterbody, when instruction carriage 7 when positive acceleration moves, this cable wire loosens, but the cable wire that acquires a certain degree strains suddenly, and promotes a weight work done, thereby reaches braking effect.
(3), constitute brake gear 14 by the hydraulic cylinder arrestment mechanism.Such as when instruction carriage 7 after positive acceleration moves to certain speed, drive a hydraulic cylinder suddenly, play braking action.
The principle of work and the procedure declaration of present embodiment are as follows:
1, the generation of acceleration
Referring to Fig. 1, Fig. 2 and shown in Figure 3, present embodiment is to draw stretch cord 8 energy storage that tie up to instruction carriage 7 other ends with the traction rope 9 that ties up to instruction carriage 7 one ends by winch or haulage gear 12, sees Fig. 2.Deformation force on stretch cord 8 reaches F
m=m
mDuring a, then discharge traction rope 9 suddenly by electromagnetic clutch 10, at this moment the pulling force of stretch cord 8 becomes external force from internal force, and acts on instruction carriage 7, makes instruction carriage 7 do accelerated motion, sees Fig. 3.
2, oppositely quicken and brake
All regulation will axially be done the acceleration test of positive negative direction along three axial each in the relevant acceleration of environmental suitability, impulse test standard.Therefore oppositely also will the testing of acceleration test, the size of braking force should satisfy: F
Instead=m
mA
Instead
3, the generation of opposite force
Referring to Fig. 1 and shown in Figure 4, instruction carriage 7 is connected with two ropes on the direction of traction rope 9, and one is traction rope 9, and another is a braking rope 13.The braking force of braking rope 13 comes from brake gear 14, and described brake gear 14 can be made of friction disc mechanism, also can promote balance weight mechanism by one and constitute, and can also be made of the hydraulic cylinder arrestment mechanism.
4, the stiffness K of stretch cord and length L
Press F
0=m
mA...... (1)
F
1=K·ΔL......(2)
Make F
0=F
1, K is a constant, then stretch cord draws the constant Δ L must be the range of linearity of stretch cord.
With deflection Δ L, can be that different length L produces, along with the different duration differences that produce pulling force of L.
F
0=K
1·ΔL
1=K
2·Δ?L
2......(3)
If K
1=2 K
2... (4)
Δ L then
1=1/2 Δ L
2... (5)
Therefore, should be according to the known conditions of test, the i.e. quality of instruction carriage and test specimen sample, m
m=m
0+ m
1, m
mBe instruction carriage quality, m
1Be the test specimen quality; The technical requirement of test, i.e. acceleration a
m, duration of shock pulse D, the stiffness K of calculating stretch cord, the tensile elongation Δ L of stretch cord.The stiffness K and the length of stretch cord are inversely proportional to, and are directly proportional with sectional area.If the linear acceleration test must be satisfied D/T
N1>5, T
N1Be the test minimum natural period of spline structure, just can determine the radical and the length of stretch cord with top formula (1) to (5).
5, the length of guide rail and width
The length of guide rail 6 and the quality of test specimen are irrelevant, are directly proportional with peak accelerator, with square being directly proportional of duration of shock pulse.The guide rail 6 general parallel double narrow guides (also can adopt the wide guide rail of wall scroll) that adopt.
6, the size of instruction carriage and structure
The size of instruction carriage 7 depends on the size of test specimen, but must guarantee enough intensity and rigidity so that fixedly test specimen and undistorted the impulsive force of transmitting.
Embodiment two: referring to shown in Figure 5, a kind of linear acceleration and impact testing machine, the horizontal linear track that has except embodiment one, instruction carriage 7, stretch cord 8, traction rope 9, electromagnetic clutch 10, tension indicator 11, winch or haulage gear 12, braking rope 13 and brake gear 14 and outer, for the requirement that can in the short duration, produce big peak accelerator, the special jigger 18 of a quality of also pulling at the rear portion of instruction carriage 7 less than instruction carriage 7, the rolling structure design of jigger 18 and guide rail 6 is with instruction carriage 7 (see shown in Figure 6, no longer repeat here).The head of jigger 18 is provided with relative impingement area with the afterbody of instruction carriage 7.Other structure is identical with embodiment one.
The test specimen fixed in position is on jigger 18 in the impulse test, and the mode that instruction carriage 7 obtains energy is identical with embodiment one, sees shown in Figure 2.The mode that instruction carriage 7 obtains acceleration and initial velocity is also identical with embodiment one, sees illustrated in figures 1 and 2.Difference is: instruction carriage 7 is pulled jigger 18 by the connection of elastic buffer 19, when jigger 18 since inertia effect and instruction carriage 7 clash into, according to barycenter head-on collision principle, the jigger 18 little because of big instruction carriage of quality 7 and the quality of carrying test specimen bumps, in impact moment, according to m
1a
1=m
2a
2Formula, test specimen can obtain very big peak accelerator in the short duration.What of the size of impulsive force and duration can be adjusted by the material of elastic buffer.
Embodiment three: referring to shown in Figure 5, a kind of linear acceleration and impact testing machine, be with the difference of embodiment two: instruction carriage 7 is provided with the jigger 18 of a quality less than instruction carriage, just jigger 18 is located on the instruction carriage 7, rather than adopts the form of pulling.Jigger 18 is slidingly connected on parallel, horizontal rectilinear orbit direction with instruction carriage 7, is oppositely arranged impingement area between instruction carriage 7 and the jigger 18.Other structure is identical with embodiment two with principle, no longer is repeated in this description here.
The foregoing description only is explanation technical conceive of the present invention and characteristics, and its purpose is to allow the personage who is familiar with this technology can understand content of the present invention and enforcement according to this, can not limit protection scope of the present invention with this.All equivalences that spirit is done according to the present invention change or modify, and all should be encompassed within protection scope of the present invention.