CN103913311A - Device for testing starting characteristic of engine - Google Patents

Abstract

The invention discloses a device for testing the starting characteristic of an engine. The device comprises a base, a fly wheel fixed to the base and a first loading device loading the constant torque to the fly wheel and further comprises a second loading device loading the waveform torque to the fly wheel. The constant torque exerted through the first loading device is combined with the waveform torque exerted through the second loading device and the constant torque and the waveform torque are commonly exerted on the fly wheel, so that the force receiving condition of the fly wheel is quite similar to the real condition, and therefore the starting characteristic of the engine can be reasonably simulated.

Description

A kind of test unit of motor starting characteristic

Technical field

The present invention relates to technical field of engines, particularly a kind of test unit of motor starting characteristic.

Background technology

Conventionally and starter cooperating, the flywheel of engine engages with the gear of starter engine, and is rotated by the gear driven flywheel of starter, to realize the starting of engine.

The Case of fly-wheel of engine has gear ring, and the gear of starter is by engaging with this gear ring, so by the transmission of torque of starter flywheel and the bent axle to engine, finally drive the piston of engine to move in cylinder.

For the starting characteristic of examination engine, as the engagement situation of the force-bearing situation of starter, gear ring and starter gear, and the permanance of gear ring etc., existing typical test method has following two kinds:

The first is to test in actual working environment, be arranged on entity engine by tested starter and gear ring, when complete machine starting, test, this method test figure reliability easy and simple to handle, that obtain is high, but will consume great amount of fuel oil, cause cost consumption larger, and very easily damage engine.

The second is to utilize starting engine endurance test unit, is arranged on test unit by flywheel and the gear ring etc. of starter, engine, friction disc etc. is conventionally also installed can applies to starter the parts of resistance on gear ring.After starter engages with gear ring, drive gear ring and flywheel rotation, in rotary course, the friction disc on gear ring is that starter applies constant resistance, the frictional resistance for simulated engine to starter.

Please refer to Fig. 1, Fig. 1 is the resistance sketch that the second test method resistance that starter is applied and actual starter are subject to.

Although the second test method has reduced experimentation cost,, it has following shortcoming:

First, the frictional resistance that the method applies starter is steady state value (as shown in phantom in FIG.), and in fact, drive the gear ring rotation initial stage at starter, starter not only overcomes the frictional resistance of above-mentioned steady state value, also overcomes periodically variable resistance to compression pression (as shown in solid line in figure) in pressure stroke, cannot simulate and the latter is this test method, visible, the stressing conditions of starter when this test method cannot engine start that is virtually reality like reality.

Second; in the process that starter is piloted engine; Speed of Reaction Wheels improves gradually; gear ring will drag the driven wheel High Rotation Speed of starter; in the time that the rotating speed of driven wheel exceedes the armature shaft rotating speed of starter; the overspeed protective device of starter should be able to make driven wheel and armature shaft throw off, and the armature shaft of starter is protected.This test method can not be verified overspeed protective device.

The 3rd, for same engine, often complete the endurancing of one push start machine, the flywheel of engine and gear ring all stop at fixed area.Taking six-in-line machine as example, due to effect and the crankshaft crank interval angle reason of compression, expansion stroke in cylinder, this region is three positions at interval of 120 degree on flywheel and gear ring circumference, and allows both sides deviation 0-3 degree.Instantly when single test starts, starter gear is always engaged on above-mentioned three positions of gear ring, causes these three position wearing and tearing of gear ring and distortion serious.This test method can not be to the above-mentioned characteristic research experiment of gear ring.

In sum, how a kind of test unit of motor starting characteristic is provided, when reasonably simulated engine starts, force-bearing situation, the especially moment of torsion of its variation by engine action being subject to of starter, be those skilled in the art's technical issues that need to address.

Summary of the invention

Object of the present invention is for providing a kind of test unit of motor starting characteristic.This test unit is force-bearing situation, the especially moment of torsion of its variation by engine action being subject to of simulated engine when starting starter reasonably.

For solving the problems of the technologies described above, the invention provides a kind of test unit of motor starting characteristic, comprise pedestal, be fixed on the flywheel of described pedestal, and load the first charger of constant-torque to described flywheel, also comprise the second charger that described flywheel is loaded to waveform moment of torsion.

The waveform moment of torsion that the constant-torque that the first charger applies applies with the second charger is combined, and acting in conjunction is in flywheel, and the stressing conditions of flywheel and real case are very approaching, thus the starting characteristic of simulated engine reasonably.

Preferably, described the second charger comprise cam, with the camshaft of described cam adaptation, and the pars contractilis that loads to described cam of vertical described camshaft; The flywheel shaft of described camshaft and described flywheel is connected.

Preferably, described pars contractilis comprises hydraulic cylinder, the plunger of described hydraulic cylinder and the Surface Contact of described cam.

Preferably, the number of described hydraulic cylinder is identical with the salient point number of described cam.

Preferably, also comprise the hydraulic cylinder fixture fixing with described pedestal.

Preferably, described hydraulic cylinder fixture comprises set collar, and described cam is positioned at the center of described set collar.

Preferably, described camshaft is connected by flange with described flywheel shaft.

Preferably, described the second charger comprises and is connected in the bent axle of described flywheel shaft and the piston component with described bent axle adaptation, and with the cylinder of described piston component adaptation.

Preferably, described the first charger comprises rotating speed efferent, and described rotating speed efferent is to described flywheel output desired speed.

Preferably, described the first charger comprises electric dynamometer.

Preferably, the arbor of described electric dynamometer is connected by flange with described camshaft.

Preferably, also comprise the starter fixed mount fixing with described pedestal, and be connected in the support member between described starter fixed mount and described flywheel shaft.

Brief description of the drawings

Fig. 1 is the resistance sketch that the second test method resistance that starter is applied and actual starter are subject to;

Fig. 2 is the structural representation of a kind of embodiment of the test unit of motor starting characteristic provided by the invention;

Fig. 3 is the structural representation of the second charger in Fig. 2, illustrates that the plunger of the hydraulic cylinder of the second charger extend out to extreme position;

Fig. 4 is the structural representation of the second charger in Fig. 2, illustrates that the plunger of the hydraulic cylinder of the second charger is retracted to extreme position;

Fig. 5 is the cut-open view of the test unit of the motor starting characteristic in Fig. 2, illustrates that this test unit has support member.

Fig. 2-Fig. 5:

Pedestal 100, flywheel 200, flywheel shaft 300, starter 400, cam 501, camshaft 502, hydraulic cylinder 503, plunger 5031, set collar 601, electric dynamometer 701, arbor 7011, starter fixed mount 800, support member 900, flange 10a

Embodiment

In order to make those skilled in the art understand better technical scheme of the present invention, below in conjunction with the drawings and specific embodiments, the present invention is described in further detail.

Please refer to Fig. 2, the structural representation of a kind of embodiment of the test unit that Fig. 2 is motor starting characteristic provided by the invention.

As shown in Figure 2, this test unit comprise pedestal 100, with the fixing flywheel 200 of described pedestal 100, this flywheel 200 is driven by starter 400, all relative this pedestal 100 is fixing with starter 400 for above-mentioned flywheel 200, the two can be connected to pedestal 100 by stationary installation separately respectively, also can be connected with pedestal 100 by same stationary installation.In engine start process, starter 400 is subject to the acting force impact of following two aspects: the frictional resistance between the each parts of engine interior, and the acting force that in cylinder, pressure gas transmits.For accurately simulating the two impact on motor starting characteristic, this test unit also arranges the first charger and the second charger.

The first charger is for apply the moment of torsion of constant value to flywheel 200, with the impact of the frictional resistance between each parts on flywheel 200 in simulated engine.

The second charger is independent of the first charger, for applying waveform moment of torsion to flywheel 200.Should be appreciated that described waveform moment of torsion refers in its change curve, to have crest and trough, the two periodically alternately occurs, as the moment of torsion changing according to sinusoidal waveform etc.Regardless of its concrete form, its Changing Pattern should be with consistent by the Changing Pattern of air work or moment of torsion compressed and that flywheel 200 is produced in actual engine cylinder, the crest value of this moment of torsion can be identical with trough value, also can be different, the concrete form of waveform moment of torsion can do rational design by adjusting physical dimension, the version etc. of the second charger, or numerical values recited, action direction to the moment of torsion applying is changed accordingly and realizes.

The waveform moment of torsion that the constant-torque that the first charger applies applies with the second charger is combined, and acting in conjunction is in flywheel 200, and the stressing conditions of flywheel 200 and real case are very approaching, thus the starting characteristic of simulated engine reasonably.

On the basis of above-mentioned embodiment, the second charger can be following form:

The second charger comprises cam 501 and the camshaft 502 with these cam 501 adaptations, cam 501 can be synchronizeed and rotate with camshaft 502, one end of camshaft 502 is fixedly connected with flywheel shaft 300, passes to flywheel shaft 300 with the described waveform moment of torsion that cam 501 is produced.In addition, also comprise the pars contractilis loading to cam 501, this pars contractilis should be able to apply the acting force perpendicular to camshaft 502 to cam 501, comprise thrust and resistance, the two is the power that forms moment, and the radius of gyration of cam 501 is the arm of force that forms moment, power coordinates formation can make cam 501 rotate moment of torsion with the arm of force.

The moment of torsion that imposes on flywheel 200 can make waveform moment of torsion that the second charger applies start with real engine by following two aspect measures time is consistent:

The first, situation when real engine is worked detects, and the thrust accordingly pars contractilis being provided and the numerical values recited of resistance rationally arrange;

Second, on the pressure-bearing surface of cam 501, each point is apart from the distance of shaft centers of camshaft 502 from difference, this distance is the arm of force of above-mentioned formation moment of torsion, therefore, according to the molded line structure of the Curve Design cam 501 of engine piston resistance to compression pression, can obtain thrust or resistance adaptive the form waveform moment of torsion that meet the demands of the suitable arm of force to provide with pars contractilis.

The design that this scheme adopts cam mechanism to combine with pars contractilis, change the to-and-fro movement of pars contractilis into flywheel 200 rotatablely move,, the thrust producing when pars contractilis motion and drag effect, on cam 501, afterwards, change the moment of torsion of cam 501 into, pass to after camshaft 502, continue to act on flywheel shaft 300, final flywheel driven 200 rotates, for flywheel 200 applies waveform moment of torsion.

It is little that cam mechanism takes up an area space, and flexibly mobile, this scheme, having simplified under the prerequisite of test unit, is tested the starting characteristic of engine exactly.

Certainly, can also adopt the loading instrument that can directly apply described waveform moment of torsion to flywheel 200, just this loading appliance requires has higher loading frequency, the true rotational frequency while work with simulated engine, and so, experimentation cost will increase.

Please refer to Fig. 3 and Fig. 4, Fig. 3 is the structural representation of the second charger in Fig. 2, illustrates that the plunger of the hydraulic cylinder of the second charger extend out to extreme position; Fig. 4 is the structural representation of the second charger in Fig. 2, illustrates that the plunger of the hydraulic cylinder of the second charger is retracted to extreme position.

Further, above-mentioned pars contractilis can be hydraulic cylinder 503, the plunger 5031 of this hydraulic cylinder 503 and the Surface Contact of cam 501, thrust to cam 501 when staff stretches out by controlling the pressure control plunger 5031 of the hydraulic oil in hydraulic cylinder 503, and plunger 5031 resistance to cam 501 while retracting.The installation site of hydraulic cylinder 503 contacts with in the middle of two salient points of cam 501 when can making plunger 5031 extend out to extreme position, and contact as principle with the salient point of cam 501 while being retracted to extreme position, thereby make hydraulic cylinder 503 apply acting force to cam 501 exactly.

Particularly, the number of cylinders that the salient point number of cam 501 should have according to the engine simulateding is determined, and below describes as an example of six cylinder engine example:

Employing has the cam 501 of three salient points, and salient point is uniformly distributed on the pressure-bearing surface of cam 501, and three line intervals 120 in three salient points and camshaft 502 axle center are spent.When the plunger 5031 of hydraulic cylinder 503 bounces back to extreme position, just contact with the salient point of cam 501; While extending out to extreme position, just contact with the pressure-bearing surface in the centre position of two salient points.When starter 400 is initiatively exported, by flywheel driven 200 and flywheel shaft 300 synchronous rotaries, because camshaft 502 is fixedly connected with flywheel shaft 300, camshaft 502 will be with moving cam 501 and flywheel 200 synchronous rotaries.

As shown in Figure 3, while extending out to extreme position taking plunger 5031 as starting point, when cam 501 starts to rotate, to plunger, 5031 effects have the acting force that makes its retraction, plunger 5031 bounces back gradually under the effect of cam 501, and the hydraulic fluid pressure in hydraulic cylinder 503 is raise, and the rotation of cam 501 is produced to resistance simultaneously, moment of torsion when simulation piston compression gas, flywheel 200 being acted on, i.e. the pressure stroke of simulated engine.

As shown in Figure 4, in the time that cam 501 actuation plunger 5031 are retracted to extreme position, plunger 5031 contacts with the salient point of cam 501, owing to thering is inertia, cam 501 will be rotated further and salient point is separated with plunger 5031, and the hydraulic fluid pressure in hydraulic cylinder 503 promotes plunger 5031 to be continued to stretch out, and actuating cam 501 is rotated further, the moment of torsion that analog gas acts on flywheel 200 while promoting piston acting, i.e. the expansion stroke of simulated engine.

After starter 400 stops driving, cam 501 will stop the rotation under the effect at plunger 5031 gradually, the planform of reference cam 501, when cam 501 shuts down, plunger 5031 is by the pressure-bearing surface in contact two salient point centre positions, and this position is also the equilibrium position of hydraulic cylinder 503 and cam 501 stop motions.It should be noted that, for six cylinder engine, there is the equilibrium position described in three in same cam 501, and any one in three all can become the stop position of plunger 5031.Even if cam 501 and plunger 5031 are through several times cycle operation, also will stop at above-mentioned equilibrium position, correspondingly, flywheel 200 also will synchronously shut down, the stop position of flywheel 200 will match with the stop position of plunger 5031, and flywheel 200 has three stop positions that distribute along even circumferential.

Cam 501 often rotates a circle, plunger arrives its extreme position 5,031 three times, six-cylinder engine crankshaft that is virtually reality like reality rotates a circle and has three pressure strokes and three expansion strokes, thus, can obtain following rule: the salient point number of cam 501 be engine number of cylinders 1/2nd.

Introduce above the loading procedure of the second charger as an example of six cylinder engine example, the engine of other type is similar with it, as, the test unit of simulation four cylinder engine adopts the cam 501 of two salient points, the test unit of simulation eight cylinder engine adopts the cam 501 of four salient points, and the test unit of simulation twelve cylinder enine adopts the cam 501 of six salient points.

The structure that the second charger adopts cam 501, camshaft 502 and hydraulic cylinder 503 to coordinate, the form of this structure is simple, mechanism's compactness, experimentation cost is lower; And because flywheel 200 has the fixing stop position distributing along even circumferential, this always stops at the locational characteristic at interval of fixed angle on circumference with flywheel in actual engine 200 and mates, and can accurately test the polishing machine of gear ring; In addition, this device does not relate to oil inflame, and energy consumption is low, pollutes little.

Certainly, pars contractilis can also adopt other structures, as long as can be to cam 501 applied thrusts and resistance, coordinates form waveform moment of torsion with the radius of gyration of cam 501, as spring, just comparatively complicated to the control gear of its elastic force.

In the above-described embodiment, the number of hydraulic cylinder 503 can be identical with the salient point number of cam 501, as, the test unit of simulation six cylinder engine has three hydraulic cylinders 503, each hydraulic cylinder 503 each salient point of corresponding cam 501 respectively.

So design has following advantage:

The first, the hydraulic fluid pressure promoting or obstruction cam 501 rotates is distributed to each hydraulic cylinder 503, the volume of each hydraulic cylinder 503 will reduce to some extent;

The stress point of the uniform cam 501 of the 2nd,, is conducive to camshaft 502 uniform stresseds, avoids camshaft 502 because local pressure frequently destroys;

The 3rd, multiple hydraulic cylinders 503 apply acting force by diverse location to cam 501 and can limit plunger 5031 stop positions more reliably, ensure that flywheel 200 stops at fixing stop position mentioned above.

Further, hydraulic cylinder 503 can be fixing by hydraulic cylinder fixture and pedestal 100.

Each hydraulic cylinder 503 is all fixing by hydraulic cylinder fixture and pedestal 100, is more conducive to ensure that each hydraulic cylinder 503 mutual when workings keep relatively static mutually, thereby avoids moving the asynchronous accuracy that affects the acting force that cam 501 is applied due to each hydraulic cylinder 503.

Closer, above-mentioned hydraulic cylinder fixture can comprise set collar 601, cam 501 is arranged to the center of this set collar 601.

As shown in Figure 3 and Figure 4, cam 501 is positioned at this set collar 601 centers, and hydraulic cylinder 503 can be evenly distributed on this set collar 601, utilizes fully loop configuration easy to process, the feature that symmetry is good.

Certainly, this hydraulic cylinder fixture can also be other versions, as rectangle framework, or the bar shaped supporting construction of stretching out from pedestal 100 etc.

The second charger can also have another kind of embodiment, such as, comprise the bent axle that is connected with flywheel shaft 300, piston component with this bent axle adaptation, and with the cylinder of this piston component cooperating, and this bent axle, piston component and cylinder are all consistent with the structure in actual engine.

So, when piston component moves in cylinder, to drive crankshaft rotating and produce moment of torsion, this moment of torsion is passed to flywheel shaft 300 and flywheel 200 by bent axle, and then react on starter 400, due to, each parts all adopt the structure in actual engine, so the waveform moment of torsion that can simulate more exactly air work in cylinder or flywheel 200 be produced when compressed.Just, the cost of which design cam 501 and hydraulic cylinder 503 combine high, but or well below the mode that adopts actual engine to test in background technology.And, in this scheme without to gas gas in the jar sparking, compared with engine overall test not to environment.

The first charger in above-mentioned each scheme can also comprise rotating speed efferent, this rotating speed efferent can directly be connected with flywheel shaft 300, also can be connected with flywheel shaft 300 by other structures, as be connected to the camshaft 502 in cam 501 and hydraulic cylinder 503 schemes, or be connected to the bent axle in crankshaft and piston assembly scheme, no matter which kind of type of attachment, as long as can apply desired speed to flywheel 200 by flywheel shaft 300.

Meet catching fire when requirement of engine at the rotating speed of starter 400, the first charger and the second charger all quit work, engine stop drives and is dragged rotation by flywheel 200, rotating speed efferent starts to export constant rotational speed, the numerical value of this rotating speed is engine idle rotating speed, starts successfully with simulated engine.Now, if the gear ring of the gear of starter 400 and flywheel 200 is thrown off, the overspeed protective device work of starter 400 is effective, starts successfully; Otherwise, this overspeed protective device fault, starting failure.

Visible, arrange after this rotating speed efferent, can carry out verification experimental verification to the overspeed protective device of starter 400, thereby improve the pilot project of motor starting characteristic test.

Particularly; above-mentioned the first charger can comprise electric dynamometer 701; this electric dynamometer 701 not only can be exported constant rotational speed so that the overspeed protective device of starter 400 is verified; can also export constant-torque; the impact of the frictional resistance with the each parts of simulated engine on flywheel 200, the numerical value of this moment of torsion according to measure or rule of thumb the resistance between definite each parts of engine determine.

Certainly, rotating speed output unit can also be set separately, as motor etc., and the first charger only has the effect that applies constant-torque, as moment load system etc.No matter how the first charger designs, as long as flywheel 200 can act on rotating speed and constant-torque.

On the basis of such scheme, because the connected mode of flange shaft has good right alignment, and do not destroy the feature of axle self structure, can be at the link of flywheel shaft 300 and camshaft 502, and camshaft 502 is provided with flange 10a with the link of the arbor 7011 of electric dynamometer 701, the arbor 7011 of electric dynamometer 701, camshaft 502, flywheel shaft 300 are the flange shaft of mutual adaptation.Certainly, above-mentioned each link also can not arrange flange 10a, and is fixedly connected with by forms such as welding.

Please refer to Fig. 5, Fig. 5 is the cut-open view of the test unit of the motor starting characteristic in Fig. 2, illustrates that this test unit has support member.

Further, this test unit also has the starter fixed mount 800 fixing with pedestal 100, and starter 400 is connected in this starter fixed mount 800.The starter 400 of different size, diverse location all can be connected to pedestal 100 by this fixed mount, and does not destroy the body construction of pedestal 100, easy to use.

In addition, between starter fixed mount 800 and flywheel shaft 300, can also be provided with support member 900, to improve the stress of flywheel shaft 300 and the junction of starter fixed mount 800, extend the serviceable life of test unit.

In above-mentioned each scheme, can also there is master controller and hydraulic control system, for example, so that the first charger and the second charger etc. are exported to steering order,, control the hydraulic cylinder 503 in cam 501 and hydraulic cylinder 503 schemes, to improve the automaticity of test unit.

Above the test unit of a kind of motor starting characteristic provided by the present invention is described in detail.Applied specific case herein principle of the present invention and embodiment are set forth, the explanation of above embodiment is just for helping to understand method of the present invention and core concept thereof.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 carry out some improvement and modification to the present invention, these improvement and modification also fall in the protection domain of the claims in the present invention.

Claims (12)

1. the test unit of a motor starting characteristic, comprise pedestal (100), be fixed on the flywheel (200) of described pedestal (100), and load the first charger of constant-torque to described flywheel (200), it is characterized in that, also comprise the second charger that described flywheel (200) is loaded to waveform moment of torsion.

2. test unit as claimed in claim 1, it is characterized in that, described the second charger comprises cam (501), the camshaft (502) adaptive with described cam (501), and the pars contractilis that loads to described cam (501) of vertical described camshaft (502); The flywheel shaft (300) of described camshaft (502) and described flywheel (200) is connected.

3. test unit as claimed in claim 2, is characterized in that, described pars contractilis comprises hydraulic cylinder (503), the plunger (5031) of described hydraulic cylinder (503) and the Surface Contact of described cam (501).

4. test unit as claimed in claim 3, is characterized in that, the number of described hydraulic cylinder (503) is identical with the salient point number of described cam (501).

5. test unit as claimed in claim 4, is characterized in that, also comprises the hydraulic cylinder fixture fixing with described pedestal (100).

6. test unit as claimed in claim 5, is characterized in that, described hydraulic cylinder fixture comprises set collar (601), and described cam (501) is positioned at the center of described set collar (601).

7. test unit as claimed in claim 6, is characterized in that, described camshaft (502) is connected by flange with described flywheel shaft (300).

8. test unit as claimed in claim 1, is characterized in that, described the second charger comprises and be connected in the bent axle of described flywheel shaft (300) and the piston component with described bent axle adaptation, and with the cylinder of described piston component adaptation.

9. the test unit as described in claim 1-8 any one, is characterized in that, described the first charger comprises rotating speed efferent, and described rotating speed efferent is to described flywheel (200) output desired speed.

10. test unit as claimed in claim 9, is characterized in that, described the first charger comprises electric dynamometer (701).

11. test units as claimed in claim 10, is characterized in that, the arbor (7011) of described electric dynamometer (701) is connected by flange with described camshaft (502).

12. test units as claimed in claim 11, it is characterized in that, also comprise the starter fixed mount (800) fixing with described pedestal (100), and be connected in the support member (900) between described starter fixed mount (800) and described flywheel shaft (300).