CN109080616B

CN109080616B - Pilot brake system for safe driving of mobile vehicle

Info

Publication number: CN109080616B
Application number: CN201811104849.8A
Authority: CN
Inventors: 刘丽华; 宋明磊; 宋新生; 董召锋; 李爱增; 魏艳楠; 闫守柱
Original assignee: Henan University of Urban Construction
Current assignee: Henan University of Urban Construction
Priority date: 2018-09-21
Filing date: 2018-09-21
Publication date: 2020-02-14
Anticipated expiration: 2038-09-21
Also published as: CN109080616A

Abstract

The invention discloses a pilot braking system for safe driving of a mobile vehicle, which comprises: a brake disc provided on a hub of a moving vehicle; the brake force application mechanism is provided with a disc-shaped main brake body and a disc-shaped pilot brake body, and the main brake body and the pilot brake body form a certain gap with the brake disc; a brake pedal mechanism including a pedal and a control member for detecting a depression state of the pedal; a hydraulic pressure supply mechanism that supplies hydraulic oil to the brake biasing mechanism in accordance with a depression state of the pedal detected by the control unit; wherein: when the pedal is switched to a stepping state, the brake force application mechanism enables the action speed of the pilot brake body to be larger than the action speed of the main brake body by utilizing the hydraulic oil provided by the hydraulic supply mechanism so that the pilot brake body brakes the brake disc before the main brake body.

Description

Pilot brake system for safe driving of mobile vehicle

Technical Field

The invention relates to the technical field of braking of a mobile vehicle, in particular to a pilot braking system for safe running of the mobile vehicle.

Background

The braking system of the moving vehicle is the core for ensuring the running safety of the vehicle. At present, hydraulic braking is mostly adopted in a braking system of a car (a kind of moving vehicle). Specifically, a brake system of a car includes: a brake disc, a brake pedal mechanism, a hydraulic pressure supply mechanism (including a hydraulic pump, a hydraulic oil tank, and related control valves, etc.), and a brake application mechanism. The brake disc is arranged on a wheel hub of a vehicle; the brake force applying mechanism generally comprises a hydraulic oil cylinder and a brake block, wherein the brake block is arranged on a piston rod of the hydraulic oil cylinder and is arranged opposite to the brake disc at intervals; the brake pedal mechanism comprises a pedal and a control part (the control part is used for detecting the depth of the pedal being stepped on), the stepped pedal controls the hydraulic supply mechanism through the control part, so that the hydraulic supply mechanism provides hydraulic oil for the hydraulic oil cylinder, the piston rod moves towards the brake disc, the brake block is tightly abutted against the brake disc, the rotation of the brake disc is limited through the friction force formed between the brake disc and the brake disc, and the vehicle is kept in a static state or the running vehicle is stopped.

It is easily understood that when the vehicle is in a low temperature environment (e.g., the vehicle is in winter) or the vehicle is left idle for a long time, the viscosity of the hydraulic oil for supplying hydraulic power becomes large, for example, in winter, when the vehicle which is parked for a long time is started, the oil temperature of the hydraulic oil is low, and the viscosity thereof increases. If a vehicle parked for a long time runs after starting in winter and brakes by stepping on a brake pedal (in practice, most drivers drive the vehicle), because the viscosity of hydraulic oil is high, the amount of hydraulic oil supplied to a hydraulic oil cylinder by a hydraulic pump per unit time is smaller than that when the viscosity is normal, which inevitably causes a low moving speed of a piston rod, and a long time for a brake pad to move to a brake disc, and this prolongs the braking time of the vehicle, therefore, the vehicle is very disadvantageous to safe running, and particularly, the braking time is extended and the braking distance is increased when the viscosity (oil temperature) of the hydraulic oil is low and the running speed of the vehicle is high.

Disclosure of Invention

In view of the above technical problems in the prior art, embodiments of the present invention provide a pilot braking system for safely driving a mobile vehicle.

In order to solve the technical problem, the embodiment of the invention adopts the following technical scheme:

a pilot brake system for safely driving a mobile vehicle, comprising:

a brake disc provided on a hub of a moving vehicle;

the brake force application mechanism is provided with a disc-shaped main brake body and a disc-shaped pilot brake body, and the main brake body and the pilot brake body form a certain gap with the brake disc;

a brake pedal mechanism including a pedal and a control member for detecting a depression state of the pedal;

a hydraulic pressure supply mechanism that supplies hydraulic oil to the brake biasing mechanism in accordance with a depression state of the pedal detected by the control unit; wherein:

when the pedal is switched to a stepping state, the brake force application mechanism enables the action speed of the pilot brake body to be larger than the action speed of the main brake body by utilizing the hydraulic oil provided by the hydraulic supply mechanism so that the pilot brake body brakes the brake disc before the main brake body.

Preferably, the brake forcing mechanism further comprises:

a cylinder body;

a piston disposed in the cylinder and dividing an interior of the cylinder into a first chamber and a second chamber;

the first end of the piston rod is connected to the piston, the second end of the piston rod penetrates through the second chamber to extend out of the cylinder body, the main brake body is arranged at the second end of the piston rod, and a sliding hole is formed from the piston to the main brake body;

a slide core disposed in the slide hole and slidable along the slide hole;

a first end of the pilot push rod is connected to the sliding core, a second end of the pilot push rod penetrates through the sliding hole and extends to the main brake body, and the pilot brake body is arranged at the second end of the pilot push rod;

and the hydraulic damping mechanism is used for limiting the flow of the hydraulic oil flowing out of the second chamber so that when the hydraulic supply mechanism supplies the hydraulic oil to the first chamber, the supplied hydraulic oil pushes the sliding core to enable the speed of the supplied hydraulic oil to be larger than the speed of the supplied hydraulic oil pushing the piston.

Preferably, the difference between the area of the piston facing the first chamber and the area facing the second chamber is smaller than the area of the spool facing the first chamber.

Preferably, the hydraulic pressure supply mechanism includes:

the oil tank is used for containing hydraulic oil;

a hydraulic pump connected to the oil tank,

the electromagnetic directional valve is connected with the hydraulic pump and has a first state that hydraulic oil enters the first cavity and flows back to the oil tank from the second cavity; the second state that the hydraulic oil enters the second cavity and flows back to the oil tank from the first cavity; wherein:

the control portion controls the electromagnetic directional valve to switch to the first state when the pedal is stepped on, and controls the electromagnetic directional valve to switch to the second state when the pedal is rebounded.

Preferably, a return spring is further sleeved on the pilot push rod.

Preferably, the hydraulic damping mechanism is disposed on a pipeline between the second chamber and the electromagnetic directional valve.

Preferably, the first and second electrodes are formed of a metal,

a first pipeline and a second pipeline are formed on a pipeline between the second chamber and the electromagnetic directional valve;

the hydraulic damping mechanism is a throttle valve, and the throttle valve is arranged on the first pipeline;

and a one-way valve is arranged on the second pipeline, and an outlet of the one-way valve is communicated with the second chamber.

Compared with the prior art, the pilot braking system for the safe running of the mobile vehicle has the advantages that the pilot braking body is additionally arranged, the characteristic that the pilot braking body has larger displacement under the unit displacement compared with the main braking body is utilized, and when the condition that the flow of hydraulic oil provided for the braking force application mechanism is smaller due to the large viscosity of the hydraulic oil is met, the provided smaller hydraulic oil can drive the rapidly moving pilot braking body to complete the rapid braking of the brake disc through the smaller flow required by the driving, so that the running safety of the vehicle under the conditions of low temperature environment and short starting time is improved.

Drawings

Fig. 1 is a schematic structural diagram of a pilot braking system for safely driving a moving vehicle according to an embodiment of the present invention (the pedal is in an un-depressed state).

Fig. 2 is an enlarged view of a portion a of fig. 1.

Fig. 3 is a schematic structural diagram of a pilot brake system for safely driving a moving vehicle according to an embodiment of the present invention (the pedal is in a depressed state, the pilot brake body reaches the brake disc, and the main brake body does not reach the brake disc).

Fig. 4 is an enlarged view of a portion B of fig. 3.

Fig. 5 is a schematic structural diagram of a pilot brake system for safely driving a moving vehicle according to an embodiment of the present invention (the pedal is in a depressed state, and both the pilot brake body and the main brake body reach the brake disc and have applied a sufficient braking force).

Fig. 6 is an enlarged view of a portion C of fig. 5.

Fig. 7 is a schematic structural diagram of a pilot braking system for safely driving a mobile vehicle according to an embodiment of the present invention (the pedal is in a rebound state).

In the figure:

10-a brake disc; 20-a brake forcing mechanism; 21-cylinder body; 211-a first chamber; 212-a second chamber; 22-a piston; 221-a piston rod; 23-a sliding core; 231-a pilot tappet; 24-a slide hole; 25-a main braking body; 26-a pilot braking body; 27-a return spring; 28-a hydraulic damping mechanism; 291-first retainer ring; 292-a second retaining ring; 30-a hydraulic supply mechanism; 31-a hydraulic pump; 32-a solenoid directional valve; 33-a one-way valve; 341-first conduit; 342-a second conduit; 35-an oil tank; 40-a brake pedal mechanism; 41-pedal; 42-a control component; 50-a communication mechanism; 51-a valve body; 52-a valve cavity; 53-a valve core; 54-pre-tightening the spring; 60-electromagnetic switch valve; 70-a power mitigation mechanism; 71-oil-passing body; 711-first oil gallery; 712-a second oil passage; 713-third oil gallery; 714-fourth oil gallery; 715-a fifth oil passage; 716-a first comparison chamber; 717-second alignment Chamber; 718-a sliding chamber; 719-necking; 72-sliding comparison core; 73-compare the spring.

Detailed Description

In order to make the technical solutions of the present invention better understood, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

The embodiment of the invention discloses a pilot braking system for safely driving a mobile vehicle, which is particularly suitable for passenger vehicles such as small cars. The pilot braking system adopts hydraulic braking, and the braking effect is particularly outstanding under the conditions that the temperature of braking liquid (namely hydraulic oil) is low and the viscosity is high.

As shown in fig. 1 to 7, the pilot brake system includes a brake disk 10, a brake application mechanism 20, a brake pedal 41 mechanism 40, and a hydraulic pressure supply mechanism 30.

The brake disc 10 is arranged on the hub of a moving vehicle, the disc surface of the brake disc 10 being arranged to be wear resistant and to have a high coefficient of friction. The brake forcing mechanism 20 includes a drive member, and a disc-shaped main brake body 25 and a disc-shaped pilot brake body 26, and when the vehicle is not braked, the main brake body 25 and the pilot brake body 26 are opposed to the brake disc 10 with a certain gap therebetween; when braking of the vehicle is required, the driving means is used to drive the main braking body 25 and the pilot brake towards the brake disc 10 to contact the brake disc 10 to form friction to brake the brake disc 10. The hydraulic supply unit is used to supply hydraulic oil to the driving unit so that the hydraulic oil drives the main braking body 25 and the pilot braking body 26 (it should be understood that the main braking body 25 and the pilot braking body 26 may be driven to move in different directions depending on the oil path provided to the driving unit, that is, the hydraulic supply unit may also be able to move the main braking body 25 and the pilot braking body 26 in a direction away from the brake disc 10 to separate from the brake disc 10 to contact braking of the brake disc 10 by supplying hydraulic oil to the driving unit). The brake pedal 41 mechanism 40 includes a brake pedal 41 disposed in the cab, and a control unit 42, the control unit 42 being configured to detect a state where the brake pedal 41 is depressed (that is, the control unit 42 being configured to detect whether the brake pedal 41 is depressed), the control unit 42 being configured to control the hydraulic pressure supply mechanism 30 to supply the hydraulic oil of different oil paths to the drive unit according to whether the brake pedal 41 is depressed, so as to obtain a control result as follows: when the pedal 41 is stepped on, the hydraulic oil supplied by the hydraulic supply mechanism 30 causes the main braking body 25 and the pilot braking body 26 to move toward the brake disc 10 to eventually come into contact with the brake disc 10 to effect braking of the brake disc 10; when the pedal 41 is returned or the pedal 41 is in a non-depressed state, the oil path of the hydraulic oil supplied from the hydraulic pressure supply mechanism 30 causes the main brake body 25 and the pilot brake body 26 to be separated from the brake disc 10 to release the braking of the brake disc 10. In the present embodiment, the brake biasing mechanism 20 drives the main brake body 25 and the pilot brake body 26 by the hydraulic oil supplied from the hydraulic pressure supply mechanism 30 as follows: the hydraulic oil is made to preferentially drive the pilot braking body 26 and the speed of driving the pilot braking body 26 is made to be greater than the main braking body 25 so that the pilot braking body 26 first contacts the brake disc 10 to brake the brake disc 10 and the main braking body 25 falls to contact the brake disc 10 after the pilot braking body 26. In the present embodiment, the flow rate of the hydraulic oil required to move the pilot brake disk 10 by a unit distance is lower than that of the main brake disk 10. If the main brake body 25 is compared with the conventional brake pad (only one brake pad brakes the brake disc 10 in the conventional art), the time taken for the pilot brake body 26 to reach the brake disc 10 is shorter than the main brake body 25.

According to the invention, by additionally arranging the pilot braking body 26 and utilizing the characteristic that the pilot braking body 26 has larger displacement compared with the main braking body 25 under the unit displacement, when the flow of the hydraulic oil provided for the braking force application mechanism 20 is smaller due to large viscosity of the hydraulic oil, the fast braking of the brake disc 10 can be finished by the pilot braking body 26 which can move fast by driving less hydraulic oil through driving the required flow, so that the driving safety of the vehicle under the conditions of low temperature environment and short starting time is improved.

As shown in fig. 1 and 2, a preferred embodiment of the present invention provides a brake application mechanism 20 capable of realizing the above-described operating characteristics of two brake bodies, wherein a driving part in the brake application mechanism 20 includes: cylinder 21, piston 22, piston rod 211, slide core 23, pilot rod 231, return spring 27, and hydraulic damping mechanism 28. In the present embodiment, the hydraulic supply mechanism 30 includes an oil tank 35, a hydraulic pump 31, a solenoid directional valve 32, and other control elements.

As shown in fig. 1 and 2, in the brake forcing mechanism 20: the cylinder 21 is provided on a vehicle suspension or a wheel hub; the piston 22 is provided in the cylinder 21 and divides the cylinder 21 into a first chamber 211 and a second chamber 212; a first end of the piston rod 211 is integrally formed on the cylinder housing 21 or is screw-coupled to the cylinder housing 21, a second end of the piston rod 211 extends out of the cylinder housing 21 (extends toward the brake disk 10) through the second chamber 212 (such that the second chamber 212 is formed as a rod chamber), and the main brake body 25 is fixed to the second end of the cylinder housing 21; a slide hole 24 is opened from an end surface of the piston 22 facing the first chamber 211 to an end surface of the main brake body 25 facing the brake disc 10, and a housing cavity capable of housing the pilot brake body 26 is provided at one end of the slide hole 24 located at the main brake body 25; the sliding core 23 is arranged in the sliding hole 24 and forms a sealing fit with the sliding hole 24, and it is easy to understand that hydraulic oil in the first chamber 211 can apply hydraulic force to the sliding core 23 to push the sliding core 23 to move towards the brake disc 10; the first end of the pilot push rod 231 is fixed on the slide core 23, the second end of the pilot push rod 231 penetrates through the slide hole 24 and extends to the main brake body 25, and the pilot brake body 26 is fixed at the second end of the pilot push rod 231; a first retaining ring 291 is arranged at a position of the slide hole 24 at a certain distance from the slide core 23, and the return spring 27 is sleeved on the pilot push rod 231 and is positioned between the slide core 23 and the first retaining ring 291, so that when a certain pressure is not built in the hydraulic oil in the first chamber 211, the spring pushes the slide core 23 to be positioned at the second end of the slide hole 24, and the pilot brake body 26 is accommodated in the accommodating cavity and is flush with the main brake body 25; a second stopper 292 is disposed on the slide hole 24 in the direction of the slide core 23 facing the first chamber 211, and the second stopper 292 restricts the slide core 23 from sliding out of the slide hole 24. The hydraulic damping mechanism 28 is in communication with the second chamber 212, the hydraulic damping mechanism 28 functioning to: the hydraulic brake device is used for limiting the flow of hydraulic oil flowing out of the second chamber 212, so as to limit the hydraulic oil in the first chamber 211 to push against the piston 22, so that the piston rod 211 drives the main brake body 25 to move too fast, and meanwhile, the hydraulic oil entering the first chamber 211 enters the slide hole 24 to push against the slide core 23, so that the speed of the pilot brake body 26 moving towards the brake disc 10 is greater than that of the main brake body 25.

As shown in fig. 1, in the hydraulic pressure supply mechanism 30: the oil tank 35 is provided in the vehicle and is used for containing hydraulic oil and recovering the hydraulic oil; the hydraulic pump 31 sucks the hydraulic oil to the oil tank 35 and serves as a power source for supplying the hydraulic oil to the first chamber 211 and the second chamber 212 of the cylinder block 21; the electromagnetic directional valve 32 has an inlet connected to the hydraulic pump 31, an oil return port connected to the oil tank 35, and two working ports respectively communicating with the first chamber 211 and the second chamber 212; the electromagnetic directional valve 32 has two operating states, which are: a first state, as shown in fig. 3, for allowing the hydraulic oil supplied from the hydraulic pump 31 to enter the first chamber 211 and allowing the hydraulic oil in the second chamber 212 to flow back to the oil tank 35; the second state, as shown in fig. 1, is for allowing the hydraulic oil supplied from the hydraulic pump 31 to enter the second chamber 212, and allowing the hydraulic oil in the first chamber 211 to flow back to the oil tank 35. The two states are controlled by the on/off control of the solenoid in the solenoid directional valve 32. In the present embodiment, the control member 42 in the brake pedal 41 mechanism 40 is used to control the on/off of the electromagnetic coil such that when the pedal 41 is depressed, the electromagnetic directional valve 32 is switched to the first state by the control member 42, and when the pedal 41 is rebounded or in a non-depressed state, the electromagnetic directional valve 32 is switched to the second state by the control member 42. In a preferred aspect of the present embodiment, two branches are formed on the pipeline connecting between the electromagnetic directional valve 32 and the second chamber 212, that is: a first branch and a second branch. The hydraulic damping mechanism 28 is disposed on the first line 341, and a check valve 33 is disposed on the second line 342 such that an outlet of the check valve 33 communicates with the second chamber 212, and preferably, a throttle valve is selected as the hydraulic damping mechanism 28.

The operation process of the pilot brake system disclosed in the above embodiment is as follows:

when braking of the running vehicle is required, as shown in fig. 3 and 4, the driver steps on the pedal 41, the control part 42 controls the electromagnetic directional valve 32 to switch to the first state, hydraulic oil is supplied into the first chamber 211 through the electromagnetic directional valve 32, hydraulic oil entering the first chamber 211 simultaneously applies hydraulic force to the piston 22 and the spool 23, while since the hydraulic damping mechanism 28 limits the outflow amount of hydraulic oil of the second chamber 212, and since the cross section of the first chamber 211 is larger than the cross section of the slide hole 24 (so that the amount of hydraulic oil required for moving the piston 22 by a unit displacement is larger than the amount of hydraulic oil required for moving the spool 23 by a unit displacement), so that the hydraulic oil entering the first chamber 211 preferentially drives the spool 23 to move and has a speed larger than the piston 22, thereby causing the pilot braking body 26 to contact the brake disc 10 first, and then, as shown in fig. 5 and 6, the main braking body 25 then contacts the brake disc 10. In this way, the pilot brake body 26 applies braking to the brake disk 10 in a short time.

It should be noted that: although the hydraulic damping mechanism 28 limits the outflow of the hydraulic oil from the second chamber 212, the limitation will not make the time for the main braking body 25 of the present invention to reach the brake disc 10 significantly longer than the time for the brake pad to reach the brake disc 10 in the prior art, because the amount of hydraulic oil supplied into the chamber by the bronze drum hydraulic pump 31 is not enough due to the high viscosity, and the flow rate is not sufficient, and the moving speed of the piston 22 will not be fast even if the hydraulic damping mechanism 28 is not provided.

When the brake needs to be released, the driver releases the pedal 41, as shown in fig. 1 and 7, the control component controls the electromagnetic directional valve 32 to switch the electromagnetic directional valve 32 to the second state, the hydraulic oil supplied by the hydraulic pump 31 is supplied to the second chamber 212 through the electromagnetic directional valve 32 and the check valve 33 (a small portion of the hydraulic oil is also supplied through the throttle), the hydraulic oil supplied to the second chamber 212 pushes the piston 22 to move the piston 22 toward the first chamber 211, thereby driving the main brake body 25 away from the brake disc 10, the hydraulic oil in the first chamber 211 flows back to the oil tank 35 through the electromagnetic directional valve 32, and at the same time, the compressed return spring 27 is returned, so that the sliding core 23 and the pilot push rod 231 move toward the first chamber 211, thereby moving the pilot brake body 26 away from the brake disc 10 and finally being accommodated in the accommodating cavity.

The advantages of the above embodiment are:

1. the main brake body 25 and the pilot brake body 26 are skillfully driven by hydraulic oil entering one oil cylinder, so that the whole structure is compact.

2. The present invention provides a hydraulic damping mechanism 28 to make the pilot braking body 26 achieve a faster differential motion than the main braking body 25, thereby enabling the brake disc 10 to obtain a braking force in a shorter time.

3. The throttle valve and the check valve 33 are respectively disposed on the first pipe 341 and the second pipe 342, so that not only can the pilot braking body 26 realize rapid braking on the brake disc 10 by using the throttle valve, but also when the braking on the brake disc 10 needs to be released, the hydraulic oil can smoothly enter the second chamber 212 to drive the piston 22 to move reversely by using the characteristic of small damping of the check valve 33 on the hydraulic oil, and further, the braking force of the main braking body 25 on the brake disc 10 can be smoothly cancelled.

4. The total moving inertia of the pilot braking body 26, the pilot push rod 231 for driving the pilot braking body and the slide core 23 is smaller than that of the main braking body 25, the piston rod 211 for driving the pilot braking body and the piston 22 for driving the pilot braking body, so that the action response of the pilot braking body 26 is more sensitive than that of the main braking body 25, and the action time of the pilot braking body 26 is further shortened.

In a preferred embodiment of the present invention, as shown in fig. 3 and 4, a conduit is further provided between the first chamber 211 and the second chamber 212, and the electromagnetic opening/closing valve 60 and the communication mechanism 50 are provided on the conduit. The electromagnetic switch valve 60 is controlled by the control part 42 in the brake pedal 41 mechanism 40 to switch on and off the electromagnetic coil in the electromagnetic switch valve 60 and switch on and off the electromagnetic switch valve 60, so that when the pedal 41 is stepped on, the control part 42 controls the electromagnetic switch valve 60 to be opened, and when the pedal 41 is rebounded, the control part 42 controls the electromagnetic switch valve 60 to be closed. The communication mechanism 50 includes a valve body 51, a valve spool 53, and a biasing spring 54. A valve cavity 52 is formed in the valve body 51, the valve core 53 is arranged in the valve cavity 52 and can slide along the valve cavity 52, a first end of the valve cavity 52 is communicated with the second chamber 212 through a conduit, and the pre-tightening spring 54 is used for pushing the valve core 53 with a certain pre-tightening force so that the valve core 53 blocks the first end of the valve cavity 52; the middle of the valve chamber 52 communicates with the first chamber 211 through a conduit, such that when hydraulic oil forces the valve spool 53 to open the first end of the valve chamber 52, the hydraulic oil enters the valve chamber 52 and passes through the valve chamber 52 and the conduit into the first chamber 211.

The electromagnetic opening/closing valve 60 and the communication mechanism 50 of the pilot brake system provided in the above embodiment function as follows:

it should be understood that: the hydraulic damping mechanism 28 is not provided to reduce the speed of the piston 22 and the main braking body 25, but rather to increase the speed of the spool 23 and the pilot braking body 26 relative to the speed of the piston 22 and the main braking body 25, i.e. when the pilot braking body 26 is about to reach the brake disc 10, it is desirable that the main braking body 25 also reaches the brake disc 10 in a timely manner. The electromagnetic opening/closing valve 60 and the communication mechanism 50 function as such.

When the pilot brake body 26 reaches the brake disc 10, the hydraulic oil in the first chamber 211 is mainly used for pushing the piston 22 to move, and when the pressure of the hydraulic oil in the second chamber 212 rises to a certain degree, the hydraulic oil forces the valve element 53 in the communication mechanism 50 to open, so that the hydraulic oil in the second chamber 212 enters the first chamber 211 through the conduit (at this time, the electromagnetic switch is also in an open state), and the entering of the hydraulic oil increases the amount of the hydraulic oil entering the first chamber 211, so that the moving speed of the piston 22 can be increased.

The advantages of the above embodiment are: the first chamber 211 and the second chamber 212 are communicated through a conduit, and the electromagnetic switch valve 60 and the communication mechanism 50 are arranged on the conduit, so that the moving speed of the main braking body 25 can be increased after the pilot braking body 26 reaches the brake disc 10, and the main braking body 25 can also reach the brake disc 10 quickly.

In a preferred embodiment of the present invention, the difference between the area of the piston 22 facing the first chamber 211 and the area facing the second chamber 212 is smaller than the area of the spool 23 facing the first chamber 211. That is, the hydraulic difference (or hydraulic force is reasonable) of the hydraulic oil to the piston 22 is smaller than the hydraulic force of the hydraulic oil to the sliding core 23, so that the pilot braking body 26 can reach the brake disk 10 faster than the main braking body 25.

During the movement of the pilot braking body 26 and the main braking body 25 towards the brake disc 10, it is desirable to have both reach the brake disc 10 with a minimum time, so as to reduce the application of the braking reaction, and after both reach the brake disc 10, if not limited, both continue to move towards the brake disc 10 with the original speed, the increase of the braking force is not too great, and the resulting vibrations that deform the brake disc 10 and the relative friction of the brake disc 10 and the braking bodies increase significantly, which is detrimental to the braking.

To this end, in a preferred embodiment of the present invention, as shown in fig. 1 to 6, a power relaxing mechanism 70 is provided between the first chamber 211 and the electromagnetic directional valve 32, and the power relaxing mechanism 70 includes an oil passing body, a sliding contrast core 72, a contrast spring 73, and a plurality of oil passages. A sliding cavity 718 is opened in the oil passing body 71, and the sliding comparison core 72 is disposed in the sliding cavity 718 and divides the sliding cavity 718 into a first comparison cavity 716 and a second comparison cavity 717. The plurality of oil passages include a first oil passage 711, a second oil passage 712, a third oil passage 713, a fourth oil passage 714, and a fifth oil passage 715. The first oil channel 711 penetrates into the sliding cavity 718 from the outside of the oil passing body to form an inlet, and the electromagnetic directional valve 32 is communicated with the first oil channel 711; a second oil passage 712 communicates from the outside of the oil passing body into the lubrication cavity 718 to form an oil outlet, the second oil passage 712 communicating with the first chamber 211; the third oil passage 713 communicates the first oil passage 711 with the first comparison chamber 716; the fourth oil passage 714 communicates the second oil passage 712 with the second comparison chamber 717. The comparison spring 73 is positioned in the second comparison cavity 717, and the sliding comparison core 72 changes the opening degree of the oil inlet or the oil outlet by moving; the comparison spring 73, the hydraulic oil entering the first comparison cavity 716 through the third oil passage 713 and the hydraulic oil entering the second comparison cavity 717 through the fourth oil passage 714 enable the sliding comparison core 72 to be maintained at a relatively stable position; the fifth passage is for communicating the first oil passage 711 and the second oil passage 712, and a constricted hole is provided in the fifth passage to restrict the flow rate of hydraulic oil through the fifth passage.

At the initial stage of braking, as shown in fig. 3 to 4, most of the hydraulic oil flowing out of the electromagnetic directional valve 32 sequentially passes through the first oil passage 711, the sliding cavity 718 and the second oil passage 712 and enters the first chamber 211 (because the flow rate of the hydraulic oil is limited by the constriction 719, and the opening degrees of the oil inlet of the first oil passage 711 and the oil outlet of the second oil passage 712 are large, only a small amount of hydraulic oil passes through the fifth oil passage 715), at this time, the flow rate of the hydraulic oil is not affected by passing through the power relaxing mechanism 70, so that the two braking bodies quickly reach the brake disc 10, and a certain pressure is applied to the brake disc 10.

When a certain pressure is applied to the brake disc 10 to brake the brake disc 10, correspondingly, the pressure of the hydraulic oil in the first chamber 211 is increased and transmitted to the second oil passage 712, and transmitted to the second comparing chamber 717 through the fourth oil passage 714, so that the hydraulic oil in the second comparing chamber 717 is increased to drive the sliding comparing core 72 to move upwards to close the inlet and the outlet, and further, the first oil passage 711 is isolated from the second oil passage 712. At this time, the hydraulic oil from the electromagnetic directional valve 32 enters the first chamber 211 only through the constricted opening 719 of the fifth oil passage 715, and the constricted opening 719 makes the flow rate of the hydraulic oil entering the first chamber 211 smaller, so that the moving speed of the piston 22 is effectively suppressed, the deformation of the main braking body 25 due to the impact of the movement on the brake disk 10 is reduced, and at the same time, the large vibration due to the excessive friction is reduced.

The above embodiments are only exemplary embodiments of the present invention, and are not intended to limit the present invention, and the scope of the present invention is defined by the claims. Various modifications and equivalents may be made by those skilled in the art within the spirit and scope of the present invention, and such modifications and equivalents should also be considered as falling within the scope of the present invention.

Claims

1. A pilot brake system for safely driving a mobile vehicle, comprising:

a brake disc provided on a hub of a moving vehicle;

when the pedal is switched to a treading state, the brake force application mechanism enables the action speed of the pilot brake body to be larger than the action speed of the main brake body by utilizing the hydraulic oil provided by the hydraulic supply mechanism so that the pilot brake body brakes the brake disc before the main brake body;

the brake forcing mechanism further includes:

a cylinder body;

a slide core disposed in the slide hole and slidable along the slide hole;

2. A pilot brake system for safety travel of a mobile vehicle according to claim 1, wherein the difference between the area of the piston towards the first chamber and the area towards the second chamber is less than the area of the spool towards the first chamber.

3. The pilot brake system for safe travel of a mobile vehicle according to claim 1, wherein the hydraulic supply mechanism comprises:

the oil tank is used for containing hydraulic oil;

a hydraulic pump connected to the oil tank,

4. The pilot brake system for safe driving of mobile vehicles according to claim 1, wherein the pilot push rod is further sleeved with a return spring.

5. The pilot brake system for safe running of a mobile vehicle according to claim 3, wherein the hydraulic damping mechanism is provided on a line between the second chamber and the electromagnetic directional valve.

6. The pilot brake system for safe driving of a mobile vehicle according to claim 3,