The specific embodiment
Seeing also Figure 1 and Figure 2, is locomotive hydraulic type anti-skid brake system of the present invention, and it comprises two groups of hydraulic circuits and an electronic control unit; Wherein these two groups of hydraulic circuits are installed in respectively between front wheel brake handle 1a and the front-wheel brake 2a, and between trailing wheel brake handle 1b and the rear wheel brake 2b, adopt two groups of hydraulic circuits respectively as the brake circuit of front-wheel and trailing wheel, this hydraulic circuit comprises that one has the hydraulic actuating cylinder 10 of at least one piston rod 11, this piston rod 11 contacts with brake handle (being front wheel brake handle 1a or trailing wheel brake handle 1b), be connected the boost-up circuit 20 of hydraulic actuating cylinder 10 oil outlets 12, and be connected a release of pressure loop 30 before the arrival end 21 of this boost-up circuit 20 with behind the exit end 22, and establish a motor 40 between this release of pressure loop 30.
Consult shown in Figure 1 again, a working connection be formed by connecting between this boost-up circuit 20 and the hydraulic actuating cylinder 10 to provide drg required brake solution, this boost-up circuit 20 comprises a pressure charging valve 23 and a boiler check valve 24, this pressure charging valve 23 is a normal-open electromagnetic valve, when this electromagnetic valve is not switched on, be open circuit between its interface, make hydraulic oil deliver to drg (being front-wheel brake 2a or rear wheel brake 2b) by hydraulic actuating cylinder 10, otherwise, then be closed circuit between interface, in addition this electromagnetic valve can return back to initial position by spring after loss of power, but and this boiler check valve 24 be in order to control between this drg and the exit end 22 hydraulic oil only folk prescription to yearn for hydraulic actuating cylinder 10 mobile.
Consult shown in Figure 1 again, this release of pressure loop 30 is the hydraulic oil that is released in order to the drg release of pressure time, return major loop through this loop, this release of pressure loop 30 comprises a pump housing 31 and a pressure relieving valve 32, this pressure relieving valve 32 is a closed type electromagnetic valve, when this electromagnetic valve is not switched on, be closed circuit between its interface, otherwise, then be open circuit between interface, this electromagnetic valve can return back to initial position by spring after loss of power in addition, the driving of this pump housing 31 by this motor 40 starts carries out oil suction, and its two ends are provided with the flow direction of boiler check valve 33 with modulated pressure oil, and can establish a fuel accumulator 34 at the oil inlet 311 of the pump housing 31, required hydraulic oil when providing this pump housing 31 to start, and the situation that can vacuumize can avoid the pump housing 31 just to start the time; The oil outlet 312 of this pump housing 31 can be established a bumper 35 of being made up of an air sac pressure accumulator 351 and a flow regulating valve 352, is recalcitrated (Kick-Back) effect to brake handle produced with the pulsating pressure fluctuation that reduces the pump housing 31 oil extractions.
Consult shown in Figure 2ly again, and this electronic control unit comprises a front-wheel wheel speed sensors 51, a rear wheel rotation speed sensors 52, a slip computing element 53, a slip comparing element 54, a front-wheel controller 55 and a trailing wheel controller 56; Wherein this front-wheel wheel speed sensors 51 and rear wheel rotation speed sensors 52 are installed in front-wheel wheel speed and the trailing wheel wheel speed to detect each time on the front-wheel of locomotive and the trailing wheel respectively; And this slip computing element 53 according to the detected value of front-wheel wheel speed sensors 51 and rear wheel rotation speed sensors 52 to calculate the speed of a motor vehicle, front-wheel slip and trailing wheel slip; Because the speed of a motor vehicle is difficult for measuring, so the present invention proposes the method for calculating of an estimation speed of a motor vehicle, the maximum speed of selecting front-wheel or trailing wheel is the reference speed first time, after braking car signal is determined, again with this first time reference speed be rate of onset and set a braking time, then this rate of onset being made differential, is the speed of a motor vehicle of acceleration/accel (speed reduce) with rate of onset divided by braking time to calculate one, after reference speed and select the speed of a motor vehicle of the higher person for the first time as reality through the speed of a motor vehicle of slowing down; For instance, after the braking signal is determined, front-wheel that this records or trailing wheel the most at a high speed be 40 kilometers/hour speed (40000 meters/3600 seconds=11.1 meter per second), then first reference speed with this 11.1m/s is a starting velocity, suppose under the non-slip situation of braking and wheel, with the acceleration/accel that locomotive brake is stopped in 2 seconds, promptly braking time is 2 seconds, so can get 5.5m/s
2(11.1m/s ÷ 2=5.5m/s
2) speed of a motor vehicle of acceleration/accel, the or else disconnected front and back wheel wheel speed that measures each time point in the braking time, in the hope of first reference speed of each time point, make comparisons with above-mentioned speed after slowing down and select the higher person in the back, with as actual vehicle speed.And the calculating of this slip is shown below:
Learn that by following formula this slip is the percentum of the difference of the speed of a motor vehicle and wheel speed divided by the speed of a motor vehicle, and the slip of the slip of this front-wheel and trailing wheel is as follows:
This slip comparing element 54 be utilize experiment and slip setting the multistage control area, and judge the control area at this front-wheel slip and trailing wheel slip place, with output signal to this front-wheel controller 55 and this trailing wheel controller 56; This front-wheel controller 55 and trailing wheel controller 56 are pressure relieving valve 32 actions in order to the pressure charging valve 23 of control motor 40, boost-up circuit 20 and release of pressure loop 30.
Above-mentioned contexture locomotive hydraulic type anti-skid brake system of the present invention, motion by brake handle (being front wheel brake handle 1a or trailing wheel brake handle 1b) makes piston rod 11 motions, so that hydraulic fluid pressure to be provided, export different signals then according to the variation of slip with control boost-up circuit 20 and release of pressure loop 30, and the adjusting hydraulic fluid pressure makes this hydraulic circuit that front-wheel brake 2a and the required braking force of rear wheel brake 2b are provided.
Below describe the operating principle of native system in detail: the oil inlet 13 of the hydraulic actuating cylinder 10 of this hydraulic circuit connects a fuel tank 3, and be connected a transfer valve 4 between this hydraulic actuating cylinder 10 and the fuel tank 3, this transfer valve 4 is in order to change oil circuit, before brake handle (being front wheel brake handle 1a or trailing wheel brake handle 1b) is not pushed, the hydraulic oil of fuel tank 3 can enter in the 14a of grease chamber of hydraulic actuating cylinder 10 through transfer valve 4, to provide locomotive driving required oil mass; And after pushing brake handle (being front wheel brake handle 1a or trailing wheel brake handle 1b), provide oil pressure pressure, promote piston rod 11 motions simultaneously, make the interface of this transfer valve 4 be closed circuit, the oil of this fuel tank 3 is then entered the 14b of another grease chamber of hydraulic actuating cylinder 10 by another oil circuit 5, this moment is by the promotion of piston rod 11, make the hydraulic oil in the 14a of this grease chamber deliver to drg (being front-wheel brake 2a or rear wheel brake 2b) through pressure charging valve 23, to reach braking, conference makes that oil pressure pressure is excessive but the pressing force of working as brake handle is healed, cause the brake-pressure that offers drg excessive, and make wheel lockup, therefore this hydraulic circuit electronic control unit of arranging in pairs or groups utilizes slip with appropriate modulated pressure oil pressure, makes system have best braking force; This electronic control unit is in the locomotive driving process, constantly measure and calculate the wheel speed and the slip of front-wheel and trailing wheel, judge the brake-pressure size by the data of slip, make this electronic control unit can drive boost-up circuit 20 or 30 actions of release of pressure loop in good time, and obtain best braking force; And after this electronic control unit receives the braking signal of brake handle, then start the motor 40 of this hydraulic circuit; When pressure is crossed big wheel with locking, then make its interface be closed circuit pressure charging valve 23 energisings, again pressure relieving valve 32 is opened, make the brake noise in the oil circuit flow to fuel accumulator 34, and pressure is reduced, to reduce lock torque, motor 40 runnings simultaneously are to return brake noise major loop; And excessive when release of pressure, then start pressure charging valve 23 and close pressure relieving valve 32, to increase brake-pressure, repeat the action that above-mentioned step is controlled pressure charging valve 23 and pressure relieving valve 32, make system continue to keep suitable braking force, stop fully up to locomotive.
Locomotive hydraulic type anti-skid brake system of the present invention is to adopt two hydraulic efficiency pressure systems to control the braking force of front-wheel and trailing wheel respectively, and can be by two control of braking signals of two brake handle output; And wherein front wheel brake handle and front-wheel controller are depended in the startup of the pressure charging valve of a hydraulic circuit and pressure relieving valve, trailing wheel brake handle and trailing wheel controller are depended in the pressure charging valve of another hydraulic circuit and the startup of pressure relieving valve, therefore, make front-wheel and trailing wheel all can be according to its corresponding slip modulated pressure pressure to obtain preferable braking force.
Below be to utilize the one group slip parameter of system of the present invention through the experiment gained, see also Fig. 3, as shown in the figure, solid line is represented the valve opening and the slip relation curve of pressure charging valve, dotted line is represented the valve opening and the slip relation curve of pressure relieving valve, this group slip parameter is that this multistage control area is divided into first control area (A), second control area (B), the 3rd control area (C), the 4th control area (D) and the 5th control area (E), wherein the slip of this first control area (A) is less than 0.1%, the slip scope of this second control area (B) is at 0.1% to 0.15%, the slip scope of the 3rd control area (C) is at 0.15% to 0.25%, the slip scope of the 4th control area (D) is at 0.25% to 0.5%, and the slip of the 5th control area (E) is best greater than 0.5%.And, when this slip is positioned at first control area (A), be that the pressure charging valve standard-sized sheet of control boost-up circuit and the pressure relieving valve in release of pressure loop are closed when the slip that the slip computing element calculates is compared with the slip parameter; When this slip is positioned at second control area (B), the aperture of pressure charging valve that is the control boost-up circuit be 50% and the pressure relieving valve in release of pressure loop close; When this slip is positioned at the 3rd control area (C), be that the pressure charging valve of control boost-up circuit cuts out and the pressure relieving valve in release of pressure loop is closed; When this slip is positioned at the 4th control area (D), be that the pressure charging valve of control boost-up circuit cuts out and the aperture of the pressure relieving valve in release of pressure loop is 50%; When this slip is positioned at the 5th control area (E), be that the pressure charging valve of control boost-up circuit cuts out and the pressure relieving valve standard-sized sheet in release of pressure loop.
Below propose one and utilize system of the present invention and above-mentioned slip parameter setting to carry out actual vehicle drive test result, the braking ratio that obtains (Z) data, this braking ratio is defined as 0.56/t, and wherein t is that the speed of a motor vehicle is by the required time of 40km/h to 20km/h; This test system adopts the locomotive of a 150CC, and on the road surface of different coefficients of friction, as asphalt coating and marble road surface, sees also shown in Figure 4ly, and the friction coefficient of this asphalt coating is 0.81, and this marble ground-surface friction coefficient is 0.41; Its data are as follows:
(1) when testing, can obtain the braking ratio data of front-wheel and trailing wheel at asphalt coating:
Front-wheel: Zm=0.76; Zmax=0.63; Zmax/Zm=0.83.
Trailing wheel: Zm=0.47; Zmax=0.44; Zmax/Zm=0.94.
Wherein, this Zm represents not have the maximum braking ratio of ABS, and Zmax represents to be provided with the maximum braking ratio of ABS, and Zmax/Zm represents the degree of utilization of single control wheel ABS.
(2) when testing, can obtain the braking ratio data of front-wheel and trailing wheel on the marble road surface:
Front-wheel: Zm=0.35; Zmax=0.28; Zmax/Zm=0.8.
Trailing wheel: Zm=0.27; Zmax=0.25; Zmax/Zm=0.93.
Wherein, this Zm represents not have the maximum braking ratio of ABS, and Zmax represents to be provided with the maximum braking ratio of ABS, and Zmax/Zm represents the degree of utilization of single control wheel ABS.
And according to (for example: the 93/14/EEC standard of Communaute' E'conomique Europennee' (European Economic Community)) to the standard of cart brake system, the brake system with ABS that its explanation meets standard is Zmax/Zm 〉=0.7, so that cart has enough braking forces; And its Zmax/Zm is all greater than 0.7 as shown in Figure 4, and therefore, locomotive hydraulic type anti-skid brake system of the present invention as can be known can provide front-wheel and trailing wheel all to have enough braking forces.
In addition, locomotive hydraulic type anti-skid brake system of the present invention, be to utilize the startup decision mechanism of slip as boost-up circuit and release of pressure loop, so braking force can be adjusted with the change of the wheel speed and the speed of a motor vehicle, therefore, only need set suitable slip parameter, except the locomotive that can be applicable to 150CC, also can be used on other locomotive or conveying arrangement that needs anti-skidding and braking.
Although the present invention is illustrated with reference to accompanying drawing and preferred embodiment,, concerning those skilled in the art, the present invention can have various changes and variation.Various change of the present invention, the content that variation and equivalent are replaced by appending claims contains.