CN211592535U - Vacuum booster with double diaphragms - Google Patents

Abstract

The utility model relates to a vacuum booster of two diaphragms belongs to car braking technical field. The booster comprises a front shell component, a main cylinder push rod component, a return spring, a valve body, two power-assisted discs, two diaphragms, a middle shell component, a diaphragm, a rear shell component, a power-assisted disc, a feedback disc and a valve rod component, wherein the main cylinder push rod component is in clearance fit with the valve body, the main cylinder push rod component is in end face contact with the feedback disc, an air inlet bolt is riveted and fixed with the rear shell component, the air inlet bolt is in radial interference fit with a diaphragm guide hole, the diaphragm is in sliding fit on the air inlet bolt when the booster works, the air inlet bolt is in radial interference fit with a middle shell sealing sleeve and is sealed, and an inner hole of the air inlet. Has the advantages that: novel structure, the area of intake duct is big, does not receive the characteristics that other conditions influenced, and the air input is big, and is fast, and the booster is efficient, and the return stroke is fast, increases diaphragm riveting intensity, makes the life-span and the reliability of booster effectively improve.

Description

Vacuum booster with double diaphragms

Technical Field

The utility model belongs to the technical field of car braking, especially, to car vacuum booster's improvement.

Background

The vacuum booster is a brake servo device in a light car brake system, a sedan car brake system and a mini car brake system, and is a key component in an automobile brake system. The working principle is that when a driver steps on a brake pedal, the thrust generated by different pressure differences of two working chambers in a vacuum booster is used for amplifying the force of the brake pedal according to a designed proportion to push a piston of a brake master cylinder by utilizing the vacuum generated when a gasoline engine works or the vacuum generated by a vacuum pump additionally arranged on a diesel engine, and the brake fluid in the brake master cylinder is compressed to generate hydraulic pressure and is transmitted to a wheel brake to enable a brake shoe to be in contact with a wheel hub so as to generate frictional resistance to control the deceleration or braking of a vehicle.

In the existing automobile design, due to the improvement of the whole automobile configuration, the braking effect and the comfort of a driver, the size specification of the vacuum booster tends to be gradually increased, and the vacuum booster is transited from 6 inches, 7 inches, 8 inches and 9 inches to 10 inches, 11 inches, 7+8 inches and 8+9 inches in the normal state. The increase of the size specification of the vacuum booster can generate larger braking servo force and driving safety.

At present, the vacuum booster mainly has the structural forms of a single diaphragm type, a series connection double diaphragm type and the like. Referring to fig. 1, a conventional dual diaphragm vacuum booster is shown, which includes a front housing part 1 ', a master cylinder push rod part 2 ', a return spring 3 ', a valve body 4 ', two booster discs 5 ', two diaphragms 6 ', a middle housing part 7 ', a diaphragm 8 ', a rear housing part 9 ', a booster disc 10 ', a feedback disc 11 ', a pressing block 12 ', a locking plate 13 ', a valve rod part 14 ', a dust cover part 15 ', a rubber valve part 16 ', an air valve seat 17 ', the front shell component 1 'is in clearance fit with the rear shell component 9' and is riveted and fixed, the two diaphragms 6 'are in clearance fit with the rear shell component 9', the two diaphragms 6 'are extruded in the space between the middle shell component 7' and the front shell component 1 'and the rear shell component 9', and the two power-assisted discs 5 'are in clearance fit with the valve body 4' and are riveted and fixed together. The rubber part of the middle shell part 7 ' is in radial interference fit with the valve body 4 ', the outer diameter of a diaphragm 8 ' is in clearance fit with the rear shell part 9 ', the middle shell part 7 ' and the rear shell part 9 ' are extruded and fixed, the inner diameter of the diaphragm 8 ' is in radial interference fit with the valve body 4 ', the inner hole of a power assisting disc 10 ' is in clearance fit with the valve body 4 ', the pressing block 12 ' is in radial clearance fit with the valve body 4 ' through riveting and fixing, and one end of the pressing block is in contact with the air valve seat 17 '. The other end of the main cylinder push rod component 2 'is in contact with the end face of the feedback disc 11', the locking plate 13 'is in clearance fit with the valve body 4', the end face of the main cylinder push rod component 2 'is in clearance fit with the valve body 4', the end face of the main cylinder push rod component is in clearance fit with the rear shell component 9 'and is in clearance fit with the air valve seat 17', the air valve seat 17 'is in clearance fit with the valve rod component 14', the rubber valve component 16 'is in interference fit with the valve body 4' through riveting fixation, the end face of the rubber valve component is extruded and fixed with the valve body 4 'through the valve rod component 14', the end face of the rubber valve component is in contact with the.

The working principle of the double-diaphragm vacuum booster is shown in fig. 2, the double-diaphragm vacuum booster is composed of two vacuum cavities, namely a cavity A and a cavity C, and a cavity B and a cavity D, the cavity A and the cavity C are communicated with each other all the time, the cavity B and the cavity D are communicated with each other all the time, and the air in the A, B, C, D cavities is pumped away through vacuum tubes to form a certain vacuum degree by a vacuum source generated during the working of an engine. When braking, the valve rod part of the booster is stressed to move forwards to close the vacuum valve port of the booster, so that the two vacuum cavities are separated from the two atmospheric cavities, then the atmospheric valve port is opened, air enters the B cavity and the D cavity of the two atmospheric cavities, the two diaphragms generate vacuum servo force under the action of the pressure difference of the front cavity and the rear cavity, and in addition, the valve rod input force enables the main cylinder push rod to generate increased output force.

And after the automobile engine is started, vacuumizing the vacuum cavity of the booster.

When the automobile brakes, the valve rod input force pushes the valve rod of the control valve component, the air valve seat, the rubber valve component and the like to move forwards, the rubber valve component is in contact with the sealing surface of the valve body and seals and closes the vacuum valve port, and an atmospheric chamber and a vacuum chamber of the booster are separated. Under the action of input force and vacuum force, the air valve seat overcomes the resistance of the valve rod return spring to continuously move forwards and is separated from the rubber valve component to open the atmospheric valve port, air begins to enter the atmospheric cavity of the vacuum booster so as to enable the atmospheric cavity and the vacuum cavity to generate pressure difference, the booster generates servo force, and the servo force is transmitted to the main cylinder push rod component through the diaphragm, the booster disc and the valve body acting on the feedback disc. When the input force of the valve rod reaches a certain value, the pressure difference between the two cavities is rapidly increased due to the fact that the atmosphere entering the atmosphere cavity is continuously increased, the whole valve body, the diaphragm and the power-assisted disc move forwards under the action of the servo force, and the servo force acts on the feedback disc until the atmosphere valve port is gradually closed. An equilibrium state is reached.

When the brake is released, the valve rod input force is reduced. At the moment, under the action of the reaction force of the feedback disc and the resistance force of the return spring of the valve rod, the valve rod drives the air valve seat to return rapidly, the air valve seat compresses the rubber valve component to close the atmospheric valve port, the rubber valve component is separated from the sealing surface of the valve body to open the vacuum valve port, the atmospheric chamber of the booster is unblocked with the vacuum chamber, and the valve body moves backwards under the action of the reaction force of the push rod of the main cylinder and the resistance force of the return spring to return to the original working position.

Air intake mode of the conventional dual diaphragm booster:

the air passages of the two atmospheric chambers B and D of the conventional dual diaphragm booster are on the first diaphragm and the second diaphragm, and the positions of the air passages are shown in fig. 3.

The first diaphragm 8 ' is pressed and fixed by the middle housing part 7 ' and the rear housing part 9 ', the second diaphragm 6 ' is in clearance fit with the rear housing part 9 ', and the second diaphragm 6 ' is pressed in the space between the middle housing part 7 ' and the front housing part 1 ' and the rear housing part 9 '. Air flue position on the first diaphragm 8 'is because the restriction of structure, part wall thickness size can not be very big, can make the area of air flue arrow department on the diaphragm receive the extrusion of both sides casing after the booster assembles, actual inlet channel's sectional area will reduce, direct influence efficiency of admitting air like this, just also make the helping hand efficiency of booster discount greatly, the magnitude of interference between casing part 7 'and the back casing part 9' in also influencing, thereby indirectly influence booster return speed and diaphragm riveting intensity, the repeated braking effect variation of booster, also can directly influence the riveting intensity of diaphragm and casing, reduce booster life and reliability.

Disclosure of Invention

The utility model provides a vacuum booster of two diaphragms to solve the two conventional diaphragm boosters inlet channel and warp, admit air inefficiency, helping hand efficiency is poor, and the interference magnitude between well casing part and the back casing part reduces, influences booster return speed and diaphragm riveting intensity indirectly, and the repeated braking effect variation of booster, the interference magnitude reduces the riveting intensity of direct influence diaphragm and casing, reduces the problem of booster life and reliability.

The utility model adopts the technical proposal that: two diaphragms are extruded in the space between the middle shell part and the front shell part and between the middle shell part and the rear shell part, one end of a return spring is in clearance fit with the center of the front shell part, the other end of the return spring is in clearance fit with the valve body, two power-assisted discs are in clearance fit and riveted with the valve body together, the rubber part of the middle shell part is in radial interference fit with the valve body, a diaphragm is extruded and fixed by the middle shell part and the rear shell part, the inner diameter of the diaphragm is in radial interference fit with the valve body, the inner hole of the power-assisted disc is in clearance fit with the valve body and riveted with the valve body, a press block is in radial clearance fit with the valve body, one end of the press block is in contact with the air valve seat, the other end of the press block is in contact with the feedback disc, the dust-proof cover part is, through riveting fixation, the rubber valve part is in interference fit with the valve body, the rubber valve part is fixed with the valve body through extrusion of the valve rod part, the end face is in contact with the air valve seat, the feedback disc is in interference fit with the valve body in the radial direction, the main cylinder push rod part is in clearance fit with the valve body, the main cylinder push rod part is in contact with the end face of the feedback disc, the air inlet bolt is fixedly riveted with the rear housing part, the air inlet bolt is in interference fit with a diaphragm guide hole in the radial direction, a diaphragm is in sliding fit on the air inlet bolt when the booster works, the air inlet bolt is in interference fit and sealed with the middle housing sealing.

There is not inlet channel on a diaphragm.

The utility model has the advantages that: novel structure, the area of intake duct is big, does not receive the characteristics that other conditions influenced, and the air input is big, and is fast, and booster's is efficient, and the return stroke is fast. After the air passage on the diaphragm is cancelled, the magnitude of interference at the riveting position of the diaphragm can be increased, the riveting strength of the diaphragm is increased, and the service life and the reliability of the booster are effectively improved. The advantages are more obvious especially when the booster is frequently operated.

Drawings

FIG. 1 is a schematic diagram of a background art configuration;

FIG. 2 is a schematic diagram of the operation of the background art;

FIG. 3 is a schematic illustration of a background art air induction scheme;

fig. 4 is a schematic structural diagram of the present invention;

FIG. 5 is a schematic view of the air intake system of the present invention;

in the figure, a front shell component 1, a main cylinder push rod component 2, a return spring 3, a valve body 4, two boosting discs 5, two diaphragms 6, a middle shell component 7, a diaphragm 8, a rear shell component 9, a boosting disc 10, a feedback disc 11, an air inlet bolt 12, a pressing block 13, a locking plate 14, a valve rod component 15, a dust cover component 16, a rubber valve component 17, an air valve seat 18 and a middle shell sealing sleeve 19.

Detailed Description

Two diaphragms 6 are extruded in the space between a middle shell part 7 and a front shell part 1 and a rear shell part 9, one end of a return spring 3 is in clearance fit with the center of the front shell part 1, the other end of the return spring is in clearance fit with a valve body 4, two power-assisted discs 5 are in clearance fit with the valve body 4 and are riveted and fixed together, a rubber part of the middle shell part 7 is in radial interference fit with the valve body 4, a diaphragm 8 is extruded and fixed through the middle shell part 7 and the rear shell part 9, the inner diameter of the diaphragm 8 is in radial interference fit with the valve body 4, the inner hole of the power-assisted disc 10 is in clearance fit with the valve body 4 and is riveted and fixed together, a pressing block 13 is in radial clearance fit with the valve body 4, one end of the pressing block is in contact with an air valve seat 18, the other end of the pressing block is in contact with, the end face of the air valve seat 18 is in contact with the rear shell component 9 and is in clearance fit with the air valve seat 18, the air valve seat 18 is in clearance fit with the valve rod component 14 and is fixed through riveting, the rubber valve component 17 is in interference fit with the valve body 4 and is fixed through extrusion of the valve rod component 15 and the valve body 4, the end face of the air valve seat 18 is in contact with the air valve seat 10, the feedback disc 10 is in radial interference fit with the valve body 4, the main cylinder push rod component 2 is in clearance fit with the valve body 4, the main cylinder push rod component 2 is in end face contact with the feedback disc 11, the air inlet bolt 12 is fixed with the rear shell component 9 through riveting, the air inlet bolt 12 is in radial interference fit with a guide hole of a membrane 8, the membrane 8 is in sliding fit on the air inlet bolt 12 when the booster works, the.

There is not inlet passage on a diaphragm 8.

The working principle is as follows:

the utility model discloses a theory of operation is the same basically with conventional two diaphragm vacuum booster's theory of operation, and the mode of admitting air of both differences, the utility model discloses two diaphragm vacuum booster's the mode of admitting air adopts direct air intake mode, cancels the mode that a diaphragm air flue admits air. The arrow is an air inlet channel, and the inner hole of the air inlet bolt 12 is directly communicated with the cavity B and the cavity D of the two atmospheric chambers of the booster.

Claims (2)

1. A vacuum booster with double diaphragms is characterized in that two diaphragms are extruded in a space between a middle shell part and a front shell part and a rear shell part, one end of a return spring is in clearance fit with the center of the front shell part, the other end of the return spring is in clearance fit with a valve body, two boosting discs are in clearance fit with the valve body and are riveted and fixed together, a rubber part of the middle shell part is in radial interference fit with the valve body, a diaphragm is extruded and fixed through the middle shell part and the rear shell part, the inner diameter of the diaphragm is in radial interference fit with the valve body, the inner hole of the boosting disc is in clearance fit with the valve body and is riveted and fixed together, a pressing block is in radial clearance fit with the valve body, one end of the pressing block is in contact with an air valve base, the other end of the pressing block is in contact with a, with air valve seat clearance fit, air disk seat and valve rod part clearance fit, through riveting fixed, rubber valve part and valve body interference fit, it is fixed through valve rod part and valve body extrusion, the terminal surface contacts with the air valve seat, feedback dish and the radial interference fit of valve body, master cylinder push rod part and valve body clearance fit, master cylinder push rod part and feedback dish terminal surface contact, its characterized in that: the air inlet bolt is fixedly riveted with the rear shell component, the air inlet bolt is in radial interference fit with a diaphragm guide hole, a diaphragm is in sliding fit on the air inlet bolt when the booster works, the air inlet bolt is in radial interference fit and sealing with a sealing sleeve of the middle shell, and an inner hole of the air inlet bolt is directly communicated with two atmospheric cavities of the booster.

2. A dual diaphragm vacuum booster as set forth in claim 1 wherein: the one diaphragm is not provided with an air inlet channel.

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