CN100404337C

CN100404337C - Automobile hydraulic booster

Info

Publication number: CN100404337C
Application number: CNB2004100161635A
Authority: CN
Inventors: 张文建
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-02-06
Filing date: 2004-02-06
Publication date: 2008-07-23
Anticipated expiration: 2024-02-06
Also published as: CN1558123A

Abstract

The present invention discloses an automobile hydraulic booster belonging to the technical field of automobile, which solves the problems of small boost ratio and complicated manufacturing engineering of the existing automobile booster, etc. The automobile hydraulic booster is arranged at the master cylinder of automobile, comprising a body and a booster piston. A disk-shaped concave shoulder is arranged in the middle of the booster piston, and the back end of the booster is cylindrical and forms an adjustment chamber with a sealing gland of piston. A piston rod is arranged in the adjustment chamber, and the back end of the piston rod passes through a sealing gland of piston, and the front end of the piston rod is provided with a blocking apparatus which opens and closes the oil through hole. The lateral part of the body is provided with an electric pump and a contactor, and the electric pump is connected to a through oil pipeline between an ante-cavity to a back-cavity. An oil inlet is also arranged in the body, and a one-way valve is arranged on the oil inlet. The boost ratio of the booster can reach more than 60, and the whole product contributes to actual installation and use with small volume. The automobile hydraulic booster has the advantages of very safety and reliable performance and higher practicability.

Description

Car Hydraulic Brake Booster

Technical field

The invention belongs to automobile technical field, particularly a kind of work-saving device of hydraulic vehicle braking.

Background technology

The automobile servo-unit is the critical component of vehicle safety.In the brake system of automobile,, need to connect the treadle effort that a work-saving device reduces chaufeur in order to alleviate the working strength of chaufeur.According to relevant rules, the treadle effort of car is between 200 to 250N, and lorry is between 300 to 450N.

Used servo-unit adopts vacuum booster mostly on the automobile at present.As " vacuum brake assistor that is used for power actuated vehicle " that Chinese patent 901022551 provides, " becoming power-assisted " that " vacuum booster of band master cylinder " that Chinese patent 98212905.X provides, Chinese patent 022181415 provide or the like than vacuum booster.Become power-assisted than vacuum booster in, it mainly includes housing, piston, control cock, push rod, push rod, reaction plate and push rod, piston head end is provided with two stepped counterbore, jacking block and reaction plate free-running fit, it can change the power-assisted ratio.When setting input force, increase power output, improve brake efficiency, reduce the generation of rear-end collision accident.Though the power-assisted of above-mentioned vacuum booster ratio can change, but this vacuum booster is identical with the groundwork of other common servo-unit, all be to rely on the suction function of automotive engine qi gas port, the front/back cavity draught head of vacuum booster is increased in vacuum booster.Because the draught head maximum in chamber can only reach 80Kpa before and after the vacuum booster, further increases the power-assisted effect as needs, can only be by the diameter in chamber before and after increasing.Like this, certainly will cause volume to increase, and the space of installation brake component is very limited in the automobile.Therefore, the power-assisted of vacuum booster is than very little, and maximum can only reach about 7.

Simultaneously, the manufacturing process of vacuum booster is very complicated, and punching parts, machined part, plastic parts, rubber part etc. are arranged in the parts of its product, and the working condition requirement of product is many, cost is high.

Summary of the invention

The objective of the invention is provides the Car Hydraulic Brake Booster of novel structure in order to overcome the problems referred to above, makes it have characteristics such as safety is good, power-assisted compares height, power output is balanced, long service life.

The objective of the invention is to realize by following technical proposal: this Car Hydraulic Brake Booster is loaded on the master brake cylinder place of automobile, a brake cylinder is arranged on master brake cylinder, be provided with brake piston in the brake cylinder, this servo-unit comprises a body and intrinsic boosting piston, wherein body and brake cylinder are fixed together, the boosting piston roof pressure is in the outer end of brake piston, it is characterized in that, there is a disc shaped convex shoulder at the middle part of described boosting piston, the edge of this convex shoulder and the inner chamber of body are sealing contact, convex shoulder is separated into ante-chamber and back cavity with the inner chamber of body, and there is the oil through that ante-chamber is communicated with back cavity at the convex shoulder place of boosting piston; The rear portion of boosting piston is cylindrical, piston capping of its rear end sealed attachment; The chamber is adjusted in one of the common formation of the rear portion of boosting piston and piston capping, in adjusting the chamber, piston rod is housed, the piston capping is passed in the rear end of piston rod, the front end of a brake push rod that connects with brake pedal can with the back end in contact of piston rod, be provided with the blocking device that above-mentioned oil through is opened and closed at the front end of piston rod; Be provided with an electric pump and one at the sidepiece of body and communicate with the body ante-chamber and can control the contactless switch that electric pump opens and closes according to the oil pressure size of ante-chamber, electric pump be connected to one by ante-chamber to the oil pipe road of back cavity; Also be provided with a fuel feed hole in body, fuel feed hole communicates with the back cavity of body, and on fuel feed hole check valve is set.

When chaufeur was stepped on brake pedal, the front end roof pressure by brake push rod just can make piston rod move forward in the rear end of piston rod, drove the boosting piston roof pressure on brake piston, produced certain braking force.Simultaneously, the blocking device that makes the piston rod front end that moves forward of piston rod is closed the oil through between the ante-chamber and back cavity in the boosting piston.At this moment, fluid can not be entered in the ante-chamber by back cavity, causes oil pressure reduction in the ante-chamber, and contactless switch can make the circuit of electric pump connect, and electric pump is started working.Under the effect of electric pump, fluid can be entered in the back cavity by ante-chamber, forms high pressure and plays the power-assisted effect, further makes boosting piston roof pressure brake piston, produces bigger braking force.Simultaneously, the high pressure in the back cavity also makes the closed check valve that is in back cavity fuel feed hole place.

When the chaufeur loosen the brake, brake push rod retreats, and the blocking device of piston rod front end is open-minded, and the fluid in the back cavity enters in the ante-chamber by oil through soon, the oil pressure unanimity before and after making in the chamber.Like this, contactless switch can make the circuit of electric pump disconnect, and electric pump quits work.At this moment, boosting piston also retreats, and returns to initial condition.Simultaneously, check valve is conducting also, and fluid enters back cavity by fuel feed hole, again by oil through to ante-chamber, form circulation, and prepare for brake next time.

In above-mentioned Car Hydraulic Brake Booster, described blocking device comprises a block, and this block is located at the front end of piston rod, and is in the above-mentioned oil through, between block and boosting piston front spring is set.On block, make block can not block oil through by the front spring roof pressure, keep the unimpeded of oil through.But,, can with the block roof pressure on boosting piston, make path blockade by the effect of piston rod at glancing impact.

In above-mentioned Car Hydraulic Brake Booster, described upper cover of piston rod has rear spring, and respectively roof pressure is on locating bush and rear spring seat in the rear spring front and back end, and locating bush is placed on the piston rod, and its front end contacts with block, and rear spring seat and piston rod are connected.

Preferably the front end at piston rod is provided with a retaining edge, and this retaining is along locating bush is limited on the piston rod.Obviously, locating bush can slide on piston rod.

In above-mentioned Car Hydraulic Brake Booster, between described locating bush and the piston rod, logical oily space arranged between locating bush and the adjustment cavity wall.By logical oily space, the fluid in the back cavity is entered in the adjustment chamber.

In above-mentioned Car Hydraulic Brake Booster, described contactless switch is made up of switch, switch plunger and switch spring, the three is loaded in the body from outside to inside successively, and on body, have a through hole, this through hole makes the ante-chamber of body communicate with switch plunger, and above-mentioned switch series is connected in the control circuit of electric pump.When the oil pressure in the ante-chamber was in high value, switch plunger can overcome the elastic force of switch spring under the effect of oil pressure, and switch plunger is shunk, and switch is in off-state, and the control circuit of electric pump is disconnected.After the oil pressure in the ante-chamber descended, the power that fluid acts on the switch plunger reduced, switch plunger can be under the effect of spring the roof pressure switch, make switch conduction, electric pump is just started working.This Car Hydraulic Brake Booster is exactly the variation that utilizes oil pressure in the ante-chamber, controls the break-make of electric pump, reaches power-assisted effect.

Compared with prior art, the advantage of this Car Hydraulic Brake Booster is:

1, because the ante-chamber of servo-unit body and the hydraulic pressure difference of back cavity can reach 40 to 60 times, and therefore, its power-assisted can reach more than 60 than also, function obviously is better than common vacuum booster, high efficiency.

2, the diameter in chamber can design lessly before and after in this servo-unit body, makes the volume of entire product very little, helps actual installation and use, has higher utility.

3, in this servo-unit boosting piston be direct roof pressure on the brake piston of brake cylinder, can not work even electric pump breaks down, also can advance brake piston to produce braking force, therefore as safe as a house reliable, its structure is very reasonable.

Description of drawings

Fig. 1 is the cutaway view of this Car Hydraulic Brake Booster.

Fig. 2 is the structural representation that this Car Hydraulic Brake Booster connects with brake cylinder.

Fig. 3 is the part sectional view at piston rod front end place in this Car Hydraulic Brake Booster.

Among the figure, 1, body; 11, ante-chamber; 12, back cavity; 13, through hole; 14, check valve; 15, sealing member; 2, boosting piston; 21, front portion; 22, convex shoulder; 23, rear portion; 24, adjust the chamber; 25, locating bush; 26, front spring; 27, rear spring; 28, piston capping; 29, oil through; 3, piston rod; 31, retaining edge; 4, dust boot; 5, brake push rod; 6, electric pump; 7, contactless switch; 71, switch; 72, switch plunger; 73, switch spring; 8, brake cylinder; 81, brake piston; 9, block; 91, through hole; 10, rear spring seat.

The specific embodiment

As depicted in figs. 1 and 2, this Car Hydraulic Brake Booster comprises parts such as body 1, boosting piston 2, piston rod 3, contactless switch 7 and electric pump 6.An inner chamber is arranged in the body 1, and boosting piston 2 is in this inner chamber.

This Car Hydraulic Brake Booster is the master brake cylinder place that is loaded on automobile.A brake cylinder 8 is arranged on master brake cylinder, brake piston 81 is arranged in the brake cylinder 8.Above-mentioned body 1 is fixed together with brake cylinder 8, and boosting piston 2 roof pressures are in the outer end of brake piston 81.

In the present embodiment, boosting piston 2 is made up of

front portion

21,23 3 the part institutes in middle part and rear portion, and its middle front part 21 is cylindric, and the middle part is a convex shoulder in the form of annular discs 22, and rear portion 23 is cylindrical.

Disc convex shoulder 22 edges of boosting piston 2 and the inner chamber of body 1 are sealing contact.But boosting piston 2 can slide front and back in body 1.Convex shoulder 22 is separated into ante-

chamber

11 and 12 two parts of back cavity with the inner chamber of body 1.

Also be provided with the oil through 29 that ante-chamber 11 is communicated with back cavity 12 at convex shoulder 22 places.

The back-end sealing of boosting piston 2 connects a piston capping 28.In the present embodiment, piston capping 28 is joining by the rear portion 23 of screw thread and boosting piston 2.Rear portion 23 cavitys of boosting piston 2 are one and adjust chamber 24.

Piston rod 3 is loaded on to be adjusted in the chamber 24.Piston capping 28 is passed in the rear end of piston rod 3, with the preceding end in contact of brake push rod 5.As shown in Figure 1, in the present embodiment, the rear end of piston rod 3 is stretched out piston capping 28 slightly.In fact, be sufficiently more than the maximum moving distance of brake piston 81 in the brake cylinder 8 as long as guarantee the overhang of piston rod 3.

As shown in Figure 1, be provided with a dust boot 4 at the rear portion 23 of boosting piston 2 and the lateral surface at brake push rod 5 places, dust boot 4 is connected with body 1.Dust boot 4 plays and prevents that dust, foreign matter etc. from entering in the boosting piston 2.

As shown in Figure 3, the front end at piston rod 3 has a blocking device.This blocking device comprises block 9 and front spring 26.Block 9 is in the oil through 29 of boosting piston 2 convex shoulders 22, and front spring 26 is located between block 9 and the boosting piston 2.On block 9, make the preceding end in contact of block 9 and piston rod 3 by front spring 26 roof pressures.

As shown in Figure 1, socket locating bush 25, rear spring 27 and rear spring seat 10 successively from front to back on piston rod 3.Rear spring seat 10 is fixed in the rear end of piston rod 3.The front end of piston rod 3 has a retaining along 31.Retaining blocks locating bush 25 along 31, prevents that locating bush 25 breaks away from piston rods 3.

Between locating bush 25 and the piston rod 3, locating bush 25 and adjust logical oily space is arranged between 24 inwalls of chamber.Locating bush 25 can guarantee that with the logical oily space of adjusting between 24 inwalls of chamber back cavity 12 communicates with adjustment chamber 24.

As shown in Figure 3, the center of block 9 is through holes 91.When brake push rod 5 roof pressure piston rods 3, when piston rod 3 was moved forward, locating bush 25 was pushed down block 9, and the retaining of piston rod 3 front ends is along 31 through holes 91 that can seal block 9.At this moment, the fluid in body 1 back cavity 12 just can't enter in the ante-chamber 11 by oil through 29, realizes the function of stopping up.

After braking was removed, under the effect of front spring 26, block 9 and whole piston rod 3 retreated, and oil through 29 is also just unimpeded again.

As depicted in figs. 1 and 2, the sidepiece at body 1 is provided with electric pump 6 and a contactless switch 7.Contactless switch 7 is made up of switch 71, switch plunger 72 and switch spring 73, and the three is loaded in the body 1 from outside to inside successively.The ante-chamber 11 of body 1 communicates with switch plunger 72 by a through hole 13.Switch 71 is connected in the control circuit of electric pump 6.When ante-chamber 11 oil pressure were higher, switch plunger 72 compressing switch springs 73 disconnected switch 71, and electric pump 6 is not worked.After oil pressure dropped to a certain degree in the ante-chamber 11, switch plunger 72 can't be pushed down switch spring 73, switch 71 conductings, and electric pump 6 is also just started working.

On electric pump 6, be connected to one by the oil pipe road of ante-chamber 11 to back cavity 12.When electric pump 6 work, it is delivered to the fluid in the ante-chamber 11 in the back cavity 12, makes back cavity 12 have higher oil pressure, plays the power-assisted effect.Simultaneously, electric pump 6 also makes fluid enter and adjusts in the chamber 24, to the certain resistance of reach generation of piston rod 3.This resistance plays the effect of buffering and balance, and is excessive to prevent this servo-unit power-assisted, makes the power output equilibrium, improved the safety and reliability of this servo-unit.

After electric pump 6 is started working,, the check valve 14 that is on the fuel feed hole is closed by oppositely directed pressure.Like this, can make back cavity 12 keep higher oil pressure.When electric pump 6 quits work, also conducting of check valve 14.

As shown in Figure 1, between boosting piston 2 rear portions 23 and body 1, be provided with sealing member 15.This sealing member 15 is in order to prevent the oil liquid leakage in the back cavity 12.

Claims

1. Car Hydraulic Brake Booster, be loaded on the master brake cylinder place of automobile, a brake cylinder (8) is arranged on master brake cylinder, be provided with brake piston (81) in the brake cylinder (8), this servo-unit comprises the boosting piston (2) in a body (1) and the body (1), wherein body (1) is fixed together with brake cylinder (8), boosting piston (2) roof pressure is in the outer end of brake piston (81), it is characterized in that, there is a disc shaped convex shoulder (22) at the middle part of described boosting piston (2), the inner chamber of edge of this convex shoulder (22) and body (1) is a sealing contact, convex shoulder (22) is separated into ante-chamber (11) and back cavity (12) with the inner chamber of body (1), and the convex shoulder (22) of boosting piston (2) is located oil through (29) that ante-chamber (11) is communicated with back cavity (12); The rear portion (23) of boosting piston (2) is cylindrical, a piston capping of its rear end sealed attachment (28); The rear portion (23) of boosting piston (2) forms one jointly with piston capping (28) and adjusts chamber (24), in adjusting chamber (24), piston rod (3) is housed, piston capping (28) is passed in the rear end of piston rod (3), the front end of a brake push rod that connects with brake pedal (5) can with the back end in contact of piston rod (3), be provided with the blocking device that above-mentioned oil through (29) is opened and closed at the front end of piston rod (3); Be provided with an electric pump (6) and one at the sidepiece of body (1) and communicate with body (1) ante-chamber (11) and can control the contactless switch that electric pump (6) opens and closes according to the oil pressure size of ante-chamber (11), electric pump (6) be connected to one by ante-chamber (11) to the oil pipe road of back cavity (12); Also be provided with a fuel feed hole in body (1), fuel feed hole communicates with the back cavity (12) of body (1), and on fuel feed hole check valve is set (14).

2. Car Hydraulic Brake Booster according to claim 1, it is characterized in that, described blocking device comprises a block (9), this block (9) is located at the front end of piston rod (3), and be in the above-mentioned oil through (29), between block (9) and boosting piston (2), front spring (26) be set.

3. Car Hydraulic Brake Booster according to claim 2, it is characterized in that, be with rear spring (27) on the described piston rod (3), rear spring (27) front and back end difference roof pressure is on locating bush (25) and rear spring seat (10), locating bush (25) is placed on the piston rod (3), and its front end contacts with block (9), and rear spring seat (10) is connected with piston rod (3).

4. Car Hydraulic Brake Booster according to claim 3 is characterized in that, a retaining is set along (31) at the front end of piston rod (3), and this retaining is limited to locating bush (25) on the piston rod (3) along (31).

5. Car Hydraulic Brake Booster according to claim 4 is characterized in that, between described locating bush (25) and the piston rod (3), locating bush (25) and adjust logical oily space is arranged between the inwall of chamber (24).

6. according to each described Car Hydraulic Brake Booster of claim 1 to 5, it is characterized in that, described contactless switch (7) is made up of switch (71), switch plunger (72) and switch spring (73), the three is loaded in the body (1) from outside to inside successively, and on body (1), have a through hole (13), this through hole (13) makes the ante-chamber (11) of body (1) communicate with switch plunger (72), and above-mentioned switch (71) is serially connected with in the control circuit of electric pump (6).

7. according to each described Car Hydraulic Brake Booster of claim 1 to 5, it is characterized in that the lateral surface of locating at the rear portion (23) and the brake push rod (5) of boosting piston (2) is provided with a dust boot (4), dust boot (4) is connected with body (1).

8. Car Hydraulic Brake Booster according to claim 2 is characterized in that, the center of described block (9) is a through hole (91).

9. according to each described Car Hydraulic Brake Booster of claim 1 to 5, it is characterized in that, between boosting piston (2) rear portion (23) and body (1), be provided with sealing member (15).