Underloading, heavy duty be the master brake cylinder of conversion automatically
Technical field
The utility model relates to a kind of brake pump, relates in particular to the automatically master brake cylinder of conversion of underloading, heavy duty.
Background technology
Brake pump is that then the brake main pump pressure gas of having an effect plays the effect of braking to brake repair room when the chaufeur pin is stepped on brake pedal.Present master brake cylinder lacks the differentiation for the actual load-carrying of vehicle, time braking causes too rapidly for zero load when vehicle to cause chaufeur to step on brake, the technical matterss such as chaufeur discomfort and brake facing undue wear, when vehicle during for heavy duty owing to the brake pressure that forms braking force does not significantly improve sensitieness and the braking effect that has affected braking.
The Chinese utility model patent patent No. 01239235.9 discloses a kind of structural improvement to automobile brake master cylinder.It mainly is parallel to each other tightly the placing in the same housing of its corresponding brake pump oil outlet mechanism of anti-lock mechanism of described front and back wheel, inclined tube by top directly joins therebetween, and the neck cross section that connects neck in the rear wheel anti-acute death mechanism connects the neck cross section of neck less than the former.This kind automobile brake master cylinder is for treating structure or technical clarification with a certain discrimination under vehicle underloading, the heavy load condition.
Summary of the invention
It is a kind of simple in structure that the utility model provides, and has unloaded the braking gentle delaying, the underloading of heavy duty brake sensitivity, the master brake cylinder of the automatic conversion of heavy duty.
A kind of underloading, heavy duty is the master brake cylinder of conversion automatically, comprise the master brake cylinder pump housing, be respectively equipped with the first braking gas output unit and the second braking gas output unit in the master brake cylinder pump housing, the first braking gas output unit comprises the ram seat of being located in the master brake cylinder pump housing, ram seat periphery socket first piston, first piston periphery socket first piston seat, the first piston side cooperates formation the first air cavity with the master brake cylinder pump housing, the first air cavity is communicated with the first braking gas output interface, described first piston side also cooperates formation the second air cavity with the first piston seat, the second air cavity is communicated with automatic switching valve by the first pore, and automatic switching valve is communicated with the first air cavity by the second pore; Be provided with the first retracing spring in described the first air cavity.Described automatic switching valve comprises valve gap, throw over spring, throw over spring one end connects the master brake cylinder pump housing, the other end is by the conversion piston of packing seal connection with the 3rd pore, the conversion piston is respectively at periphery socket conversion piston seat, the center tape splicing has the valve rod of centre hole, is provided with pressure control spring between conversion piston and the valve gap; Described valve rod, valve gap, conversion piston, conversion piston seat cooperatively interact and consist of the 7th air cavity that is communicated with respectively the 3rd pore and the first pore.This kind makes the first braking gas output interface obtain different strong and weak braking pressures with the compressed air brake cylinder that the second braking gas output unit is communicated with by the difference vehicle heavy duty of automatic switching valve structure or underloading situation, so that the unloaded braking of vehicle is gentle slow, the heavy duty brake is sensitive, improves the braking comfort level of chaufeur and the service life of brake facing.Concrete for when vehicle is unloaded by the automatic switching valve structure with the second air cavity in the centre hole connection atmosphere of pressure gas by valve rod to reduce the pressure of the first air cavity, namely reduce the braking pressure of compressed air brake cylinder acquisition so that the unloaded braking of vehicle is gentle slow, when vehicle when heavy duty by the automatic switching valve structure with the second air cavity in pressure gas sealing and apply the pressure that downward pressure improves the first air cavity to first piston, namely improve braking pressure that compressed air brake cylinder obtains so that vehicle heavy duty brake is sensitive.
Described first piston lower surface is provided with the first control cock, the second piston seat that the first control cock comprises the second piston and is placed in the second piston periphery, the second piston seat periphery master brake cylinder pump housing that is connected, the second piston, the second piston seat, the master brake cylinder pump housing cooperatively interact and consist of the 3rd air cavity; Be provided with the second retracing spring in described the 3rd air cavity.This kind the first control cock structure can be replenished the pressure gas in the 3rd air cavity in when braking and be entered the first air cavity to improve the first air cavity pressure.
Described the second piston underside is provided with the 3rd piston of the airtight connection master brake cylinder of the periphery pump housing, the 3rd piston upper surface and the master brake cylinder pump housing, the second piston, the second piston seat cooperatively interact and have consisted of the 4th air cavity, and the 4th air cavity is communicated with the first air cavity by the 3rd pore.Described the 3rd piston lower surface and the master brake cylinder pump housing and the second control cock cooperatively interact and consist of the 5th air cavity, and the 5th air cavity is communicated with the second braking gas output interface.Downforce by the 4th air cavity and the second piston when braking pours into compressed air brake cylinder realization snap catch by the second braking gas output interface fast with the pressure gas in the 5th air cavity.
Described the second control cock comprises the 3rd piston seat of the 4th piston, socket the 4th piston, and the 3rd piston seat cooperates the 4th piston and the master brake cylinder pump housing to consist of the 6th air cavity, and the 6th air cavity is communicated with the braking air inlet tube interface; Be provided with the 3rd retracing spring in described the 6th air cavity.This kind the second control cock device arrives brake compression gas in the 6th air cavity by the braking air inlet tube interface, and by the 5th air cavity pressure gas is poured into compressed air brake cylinder guarantee to brake reliability when the second control cock is opened.
Be provided with rubber spring setting up and down and balance spring between described ram seat and the first piston, first piston is applied downward pressure, the push rod pressure that the minimizing ram seat is subject to improves the braking comfort level of chaufeur.
Be Split type structure as the preferred described master brake cylinder pump housing of structure, be divided into upper pump casing and lower pump body; Described the 3rd piston lower surface and master brake cylinder lower pump body and the second control cock cooperatively interact and consist of the 5th air cavity; Described the 3rd piston seat cooperates the 4th piston and master brake cylinder lower pump body to consist of the 6th air cavity, is convenient to install.
The utility model makes the first braking gas output interface obtain different strong and weak braking pressures with the compressed air brake cylinder that the second braking gas output unit is communicated with by the difference vehicle heavy duty of automatic switching valve structure or underloading situation, so that the unloaded braking of vehicle is gentle slow, the heavy duty brake is sensitive, improves the braking comfort level of chaufeur and the service life of brake facing.
Description of drawings
Be illustrated in figure 1 as the automatically master brake cylinder sectional structure scheme drawing of conversion of the utility model underloading, heavy duty.
The specific embodiment
A kind of underloading as shown in Figure 1, heavy duty is the master brake cylinder of conversion automatically, comprise the master brake cylinder pump housing 3, be respectively equipped with the first braking gas output unit and the second braking gas output unit in the master brake cylinder pump housing 3, the first braking gas output unit comprises the ram seat 1 of being located in the master brake cylinder pump housing 3, ram seat 1 periphery socket first piston 5, first piston 5 peripheries socket first piston seat 2, first piston 5 sides cooperate formation the first air cavity 7 with the master brake cylinder pump housing 3, the first air cavity 7 is communicated with the first braking gas output interface 8, first piston 5 sides also cooperate formation the second air cavity 4 with first piston seat 2, the second air cavity 4 is communicated with automatic switching valve by the first pore 21, and automatic switching valve is communicated with the first air cavity 7 by the second pore 17; Be provided with the first retracing spring 6 in the first air cavity 7.Be provided with rubber spring setting up and down 16 and balance spring 20 between ram seat 1 and the first piston 5.
Automatic switching valve comprises valve gap, throw over spring 18, throw over spring 18 1 ends connect the master brake cylinder pump housing 3, the conversion piston 22 that the other end connects with the 3rd pore 27 by packing seal 28, conversion piston 22 is respectively at periphery socket conversion piston seat, the center tape splicing has the valve rod 26 of centre hole, is provided with pressure control spring 23 between conversion piston 22 and the valve gap; Described valve rod 26, valve gap, conversion piston 22, conversion piston seat cooperatively interact and consist of the 7th air cavity 24 that is communicated with respectively the 3rd pore 27 and the first pore 21.
First piston 5 lower surfaces are provided with the first control cock, the second piston seat 11 that the first control cock comprises the second piston 12 and is placed in the second piston 12 peripheries, the be connected master brake cylinder pump housing 3, the second pistons 12, the second piston seat 11, the master brake cylinder pump housing 3 of the second piston seat 11 peripheries cooperatively interact and consist of the 3rd air cavity 10; Be provided with the second retracing spring 9 in described the 3rd air cavity 10.
The second piston 12 downsides are provided with the 3rd piston 13 of the airtight connection master brake cylinder of the periphery pump housing 3, the 3rd piston 13 upper surfaces and the master brake cylinder pump housing 3, the second piston 12, the second piston seat 11 cooperatively interact and have consisted of the 4th air cavity 25, the four air cavitys 25 by the 3rd pore 19 connections the first air cavity 7.The 3rd piston 13 lower surfaces and the master brake cylinder pump housing 3 and the second control cock cooperatively interact and consist of the 5th air cavity 29, the five air cavitys 29 connections the second braking gas output interface 30.
The second control cock comprises that the 3rd piston seat 33, the three piston seats 33 of the 4th piston 15, socket the 4th piston 15 cooperate the 4th piston 15 and the master brake cylinder pump housing 3 to consist of the 6th air cavity 31, the six air cavitys 31 and are communicated with braking air inlet tube interface 14; Be provided with the 3rd retracing spring 32 in described the 6th air cavity 31.
The concrete workflow of the utility model is as follows: when deadhead operation is braked, because the natural reaction of chaufeur is less to exerting pressure of ram seat 1 when zero load is braked, because rubber spring 16 does not give tight power when installing, and balance spring 20 when installing to give tight power larger, therefore the suffered pressure of the pressure ratio rubber spring 16 of balance spring 20 drawn stem seats 1 is much bigger, balance spring 20 and rubber spring 16 all move downward the downward elastic force first piston 5 this moment of first piston 5 generations a part of pressure gas are poured into compressed air brake cylinder by the first braking gas output interface 8 thus, first piston 5 moves downward the second piston 12 that contact promotes the first control cock, the 3rd air cavity 10 of the first control cock is opened, and the pressure gas of the 3rd air cavity 10 enters the first air cavity 7 immediately; Because the second piston 12 continues to move downward contact the 3rd piston 13, and promote the 3rd piston 13 and move downward, the pressure gas of the first air cavity 7 flowed into the 4th air cavity 25 and the 3rd piston 13 was produced a downward pressure through the 3rd pore 19 this moment, make the 3rd piston 13 promote the 4th piston 15 of the second control cock, pour into compressed air brake cylinder so that the 6th air cavity 31 is opened and by the 5th air cavity 29 pressure gas is braked gas output interface 30 by second fast.By the second braking gas output interface 30 and the first braking gas output interface 8 pressure gas is poured into compressed air brake cylinder.This moment, the pressure gas of the first air cavity 7 was little through the thrust of the conversion piston 22 of 17 pairs of automatic switching valves of the second pore, under pressure control spring 23 controls, packing seal 28 does not contact with valve rod 26 with centre hole, the second air cavity 4 is communicated with atmosphere thus, to reduce the pressure of the first air cavity, namely reduce the braking pressure of compressed air brake cylinder acquisition so that the unloaded braking of vehicle is gentle slow.
Brake when the vehicle heavy duty is travelled, owing to be that heavy duty is for the natural reaction of chaufeur, it is larger to exerting pressure of ram seat 1 when heavy duty is braked, the relative vehicle underloading of distance that moves downward of first piston 5 is longer thus, thereby so that the pressure gas pressure rises of the first air cavity 7, the pressure gas of the first air cavity 7 increases through the thrust of the conversion piston 22 of 17 pairs of automatic switching valves of the second pore, thereby overcome pressure control spring 23 elastic force so that change piston 22 to left movement, make packing seal 28 contact sealing with valve rod 26 with centre hole, and the pressure gass in the 7th air cavity 24 are pressed into the second air cavity 4, the pressure gas of the second air cavity 4 applies the pressure that downward pressure further improves the first air cavity to first piston 5, namely improves the braking pressure of compressed air brake cylinder acquisition so that vehicle heavy duty brake is sensitive.Because the large downforce during with underloading of the downforce that is subject to of first piston 5 is the 4th piston 15, also all increases of downforce that the 3rd piston 13 is subject to of the second control cock so, strengthen the air pressure of the 5th air cavity 29 and the 6th air cavity 31, further improved the braking pressure of compressed air brake cylinder acquisition so that vehicle heavy duty brake is sensitiveer.