CN107117152B - Electric pump for automobile line control braking system - Google Patents
Electric pump for automobile line control braking system Download PDFInfo
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- CN107117152B CN107117152B CN201710336197.XA CN201710336197A CN107117152B CN 107117152 B CN107117152 B CN 107117152B CN 201710336197 A CN201710336197 A CN 201710336197A CN 107117152 B CN107117152 B CN 107117152B
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
- B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
- B60T13/12—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release the fluid being liquid
- B60T13/16—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release the fluid being liquid using pumps directly, i.e. without interposition of accumulators or reservoirs
- B60T13/161—Systems with master cylinder
- B60T13/165—Master cylinder integrated or hydraulically coupled with booster
- B60T13/166—Part of the system directly actuated by booster pressure
Abstract
The invention relates to an electric pump for an automobile brake-by-wire system, belongs to the automobile industry and is applied to the automobile brake-by-wire system. The guide sleeve is in interference fit with the inner hole of the cylinder body, one axial end of the guide sleeve is in contact with the limit step of the inner hole of the cylinder body, the inner hole of the guide sleeve is a cylindrical surface, axial guide rail through grooves are symmetrically formed in two sides of the cylindrical surface, axial rack through grooves are formed in the bottom of the cylindrical surface, the diameter of the sealing cylindrical surface is larger than that of the guide part, the auxiliary leather cup is sleeved with the sealing cylindrical surface of the piston, strip-shaped protruding guide rails are symmetrically formed in two sides of the axial side of the cylindrical surface of the guide part, racks are axially arranged at the bottom of the guide part, the sealing cylindrical surface of the piston is in clearance fit with the main hole of the cylinder body, the guide part is in clearance fit with the inner hole of the guide sleeve, and the guide rail through grooves are in clearance fit with the guide rails. The invention has the advantages that: the novel structure can automatically convert the gear teeth of the gear driving wheel and the rack in a low temperature state, thereby reducing the pressure building stroke of the piston, increasing the return stroke time of the piston, being beneficial to timely supplementing brake fluid in a low temperature state and ensuring the reliable operation of the electric pump in the low temperature state.
Description
Technical Field
The invention belongs to the automobile industry and is applied to an automobile brake-by-wire system.
Background
With the development of automobile technology, new energy automobiles and intelligent driving automobiles become main directions of automobile development, and most of the two automobiles adopt a brake-by-wire system. When the new energy vehicle is used for braking energy recovery, the brake-by-wire system needs a high-pressure hydraulic source to provide high-pressure brake fluid with expected pressure, and the brake fluid is coordinated with regenerative braking to meet the braking requirement of a driver; when the intelligent driving vehicle performs active intervention braking, the brake-by-wire system needs a high-pressure hydraulic source to provide high-pressure braking liquid to apply corresponding braking pressure to a braking wheel cylinder of the vehicle. The traditional brake system with the brake master cylinder of the vacuum booster cannot provide a stable and controllable high-pressure hydraulic source due to the fact that the brake system does not have an active pressurizing function, and therefore the brake requirement of a novel vehicle cannot be met.
The brake-by-wire system requires a high pressure hydraulic source that can be stably controlled and rapidly react, and needs to be able to operate normally under low temperature conditions (e.g., around-30 ℃). The high-pressure hydraulic source supercharging device of the traditional linear control braking system is an opposite plunger hydraulic pump, a motor drives a cam (or an eccentric wheel) to rotate, and the cam (or the eccentric wheel) drives a plunger to reciprocate to form high pressure. The defects are that: the plunger pump is directly driven by the motor cam, and a speed-reducing and force-increasing mechanism is not needed, and as the plunger pump is required to output high-pressure (more than 20MPa at most) brake fluid, the plunger cross section area of the plunger pump is designed to be smaller, so that the effective volume is smaller, and the high-pressure brake fluid with enough volume required by braking can be timely output only through quick reciprocating motion. The plunger pump supplements liquid by vacuum suction generated by the volume change of the plunger cavity. At present, the brake fluid (for example, DOT3 or DOT 4) mainly used by the brake-by-wire system has increased viscosity at low temperature, the fluidity of the brake fluid is poor, and because the plunger moves faster, enough brake fluid cannot be sucked in time in each working cycle, so that the efficiency of the plunger pump for outputting high-pressure brake fluid is reduced, even the pressure cannot be built, and the driving safety is influenced. Because the viscosity of the brake fluid is increased, the brake fluid entering the matching gap between the plunger and the inner wall of the plunger cavity is reduced, and the plunger and the inner wall of the plunger cavity easily form dry friction, so that the plunger pump is worn too fast, and the service life is reduced.
Disclosure of Invention
The invention provides an electric pump for an automobile brake-by-wire system, which solves the problems of small volume of high-pressure brake fluid provided by a single cycle of an existing hydraulic pump, less brake fluid sucked in each working cycle, low efficiency of outputting the high-pressure brake fluid, quick abrasion of a plunger pump and service life of the plunger pump.
The technical scheme of the invention is as follows: the guide sleeve is in interference fit with the inner hole of the cylinder body, one axial end is in contact with the limit step of the inner hole of the cylinder body, the inner hole of the guide sleeve is a cylindrical surface, axial guide rail through grooves are symmetrically formed in two sides of the cylindrical surface, an axial rack through groove is formed in the bottom of the cylindrical surface, one end of the piston is a sealing cylindrical surface, one end of the piston is a guide part, the diameter of the sealing cylindrical surface is larger than that of the guide part, an auxiliary leather cup is sleeved with the sealing cylindrical surface of the piston, strip-shaped convex guide rails are symmetrically formed in two axial sides of the cylindrical surface of the guide part, racks are axially arranged at the bottom of the piston, the sealing cylindrical surface of the piston is in clearance fit with the main hole of the cylinder body, the guide part is in clearance fit with the inner hole of the guide sleeve, the guide rail through groove is in clearance fit with the guide rails so as to ensure that the piston slides axially in the guide sleeve, the eccentric wear of the piston and the inner hole of the cylinder body is avoided, one end of the spring limit sleeve is provided with an outward turned edge, the bottom is contacted with the bottom end surface of the cylinder body, and the other end is in radial clearance fit with the guide post, one end of the guide post is riveted with a limit retainer ring, a through hole is arranged on the side wall of a spring limit sleeve, one end of a piston return spring is contacted with a flanging of the spring limit sleeve, one end of the piston return spring is contacted with the piston, a rack is in clearance fit with a through groove of the rack, a clearance is reserved between the top of the rack and the bottom surface of the through groove of the rack, an end cover assembly is fixedly connected with one end of an inner hole of a cylinder body, a clearance is reserved between the end cover assembly end surface and the end surface of the guide sleeve, a contact switch is arranged at the contact surface of the end cover assembly and the tail end of the piston in the assembled state, a vent plug with dustproof and waterproof effects is fixedly arranged at the other end of the end cover assembly, the through hole is communicated with the inner hole of the cylinder body, a gear set reducing mechanism is meshed by four gears, a motor shaft bevel gear, a primary reducing gear, a secondary reducing gear and a transposition gear are sequentially in clearance fit with the side wall of the cylinder body and the inner hole of a bearing embedded in the gland respectively, the axial position is fixed, the rotating motor is arranged in the gland and is connected with the bevel gear through the motor shaft, the circumferential direction of the transposition gear driving wheel is provided with straight teeth in arc arrangement, the continuous wide teeth are provided with continuous narrow teeth, the narrow teeth are arranged along one side of the transposition gear driving wheel, the number of the wide teeth is M, the number of the narrow teeth is N, the transposition gear driven wheel and the meshed secondary reduction gear driving wheel are both straight teeth, the width of the driving teeth of the secondary reduction gear is larger than the tooth width of the transposition gear driven wheel so as to ensure that the transposition gear driven wheel can still be meshed with each other after the transposition gear is switched, the position block is fixed at the position, which is in a strip shape and is perpendicular to the end face of the transposition gear driving wheel, the shell of the position block is made of non-magnetic conductive material, a strip groove is arranged along the axial direction, the distance between one end of the groove and the end face of the gear is S, a strip-shaped permanent magnet is embedded in the strip groove, the angle between the connecting line of one end face of the permanent magnet and the axis of the transposition gear shaft and the first tooth center line of the driving wheel of the transposition gear is alpha, the Hall sensor is fixed on the side wall of the cylinder body, when the transposition gear drives the permanent magnet to rotate to the position near the end face of the Hall sensor, the radial clearance is d, the permanent magnet triggers the Hall sensor to send a signal to the electric control unit, the axial length of the permanent magnet ensures that the Hall sensor is triggered to send a signal when the transposition gear drives the permanent magnet to rotate to the position near the end face of the Hall sensor at two axial working positions, the two ends of the transposition gear shaft are respectively in clearance fit with the side wall of the cylinder body and the inner hole of a bearing embedded in the gland, the linear motor is fixed on the outer side of the gland, the push rod is coaxial with the transposition gear shaft, when one end of the transposition gear shaft contacts with the limiting slide under the action of the return spring in the assembled state, the other end extends out of the length of the outer wall of the gland to be L, and the clearance between the baffle cover and the end face of the push rod is K so as to ensure that the transposition gear is not subjected to axial force in an assembled state, and the baffle cover is fixedly arranged on the outer side of the side wall of the cylinder body and is coaxial with the transposition gear shaft, and the limiting slide block, the return spring and the baffle cover are axially contacted in sequence. The inside step that has of fender lid, spacing slider can be in keeping off the spacing intracavity axial slip of lid, spacing slider distance from the step is P, P is greater than L, in order to guarantee that the axial force that receives after the transposition gear switches working position is only return spring resistance, reduce the frictional resistance when transposition gear axle is rotatory, the cylinder body has the opening in rack and transposition gear action wheel meshing department, the width is for can holding transposition gear and do not take place to interfere in two working position meshing motions, there is inlet II and liquid outlet cylinder body tip, there is the check valve between inlet II and the liquid storage pot, temperature sensor installs in the liquid storage pot, there is the check valve between liquid outlet and the high pressure accumulator, there is inlet I5 inlet direction vertical upwards between the two leather cup grooves of cylinder body, the cylinder body front chamber evenly distributed has a plurality of axial shallow grooves along the inner wall circumference, the structure of two side inlet is favorable to the brake fluid in time to be replenished under vacuum suction force, rack tooth number equals narrow tooth and wide tooth number sum, the main leather cup is the E style of calligraphy leather cup of section, E opening orientation builds the pressure side.
The invention has the advantages that: the structure is novel, and the gear number of the gear driving wheel and the gear rack can be automatically converted in a low temperature state, so that the piston pressure building stroke is reduced, the piston return stroke time is prolonged, the timely replenishment of brake fluid in the low temperature state is facilitated, and the reliable operation of the electric pump in the low temperature state is ensured; the gear reduction mechanism increases the thrust of the piston, can generate large-volume high-pressure brake fluid in a single operation, reduces the reciprocating times of the piston required for outputting the same volume of high-pressure brake fluid, reduces the moving speed of the piston and prolongs the service life of the electric pump; the unique structure and the control method ensure that the gear and the rack are correctly meshed, and the occurrence of tooth striking phenomenon is prevented.
Drawings
FIG. 1 is a schematic diagram of the structure of the present invention;
FIG. 2 is a schematic view in section in the direction D of FIG. 1;
FIG. 3 is a schematic diagram of the angular position relationship of the permanent magnet triggering Hall sensor of the present invention;
FIG. 4 is a schematic view of the structure of the transposed gear of the present invention;
FIG. 5 is a schematic view of the structure of the piston of the present invention;
FIG. 6 is a schematic view of the structure of the guide sleeve of the present invention;
in the figure, a piston return spring 1, a spring limit sleeve 2, a limit retainer ring 3, a main leather cup 4, a liquid inlet I5, a secondary leather cup 6, a piston 7, a cylinder body 8, a guide sleeve 9, an end cover assembly 10, a ventilation plug 11, a through hole 12, a contact switch 13, a rack 14, a notch 15, a transposition gear 16, a secondary reduction gear 17, a primary reduction gear 18, a bevel gear 19, a rotating motor 20, a gland 21, a one-way valve 22, a liquid outlet 23, a liquid inlet II 24, a one-way valve 25, a position block 26, a front cavity 27, a liquid storage tank 28, a temperature sensor 29, a linear motor 30, a transposition gear shaft 31, a guide rail 32, a driven wheel 33, a step 34, a baffle cover 35, a return spring 36, a limit slider 37, a bearing 38, a secondary reduction gear 39, a transposition gear driving wheel 40, a push rod 41, a permanent magnet 42, a through hole 43, a guide post 44, a wide tooth 45, a narrow tooth 46, a guide rail through groove 47, a rack through groove 48, a Hall sensor 49, a limit step 50 and a shallow groove 51.
Detailed Description
The guide sleeve 9 is in interference fit with the inner hole of the cylinder body 8, one axial end is in contact with the limit step 50 of the inner hole of the cylinder body 8, the inner hole of the guide sleeve 9 is a cylindrical surface, axial guide rail through grooves 47 are symmetrically formed on two sides of the cylindrical surface, an axial rack through groove 48 is formed at the bottom of the cylindrical surface, one end of the piston 7 is a sealed cylindrical surface, the other end of the piston 7 is a guide part, the diameter of the sealed cylindrical surface is larger than that of the guide part, the auxiliary leather cup 6 is sleeved with the sealed cylindrical surface of the piston 7, strip-shaped raised guide rails 32 are symmetrically formed on two axial sides of the cylindrical surface of the guide part, racks 14 are axially arranged at the bottom of the guide part, the sealed cylindrical surface of the piston 7 is in clearance fit with a main hole of the cylinder body 8, the guide part is in clearance fit with the inner hole of the guide sleeve 9, the guide rail through grooves 47 are in clearance fit with the guide rails 32 so as to ensure that the piston 7 slides axially in the guide sleeve 9, eccentric wear of the piston 7 and the inner hole of the cylinder body 8 is avoided, one end of the spring limit sleeve 2 is provided with an outward flanging, the end face of the bottom of the cylinder body 8 is contacted with the end face of the guide post 44 of the piston 7 at the other end, the limit retainer ring 3 is riveted at one end of the guide post 44, a through hole 43 is formed in the side wall of the spring limit sleeve 2, one end of the piston return spring 1 is in flanging contact with the spring limit sleeve 2, one end of the piston return spring is in contact with the piston 7, the rack 14 is in clearance fit with a rack through groove 48, a clearance is reserved between the top of the rack 14 and the bottom face of the rack through groove 48, the end cover assembly 10 is fixedly connected with one end of an inner hole of the cylinder body 8, the end face of the end cover assembly 10 is in clearance with the end face of the guide sleeve 9, a contact switch 13 is arranged at the contact face of the end cover assembly 10 and the tail end of the piston 7 in an assembled state, a ventilation plug 11 with a dustproof and waterproof effect is fixedly arranged at the other end, the through hole 12 is communicated with the inner hole of the cylinder body 8, and a gear set reducing mechanism is meshed by four gears, namely a motor shaft bevel gear 19, a primary reducing gear 18, a secondary reducing gear 17, the two shaft ends of the primary reduction gear 18 and the secondary reduction gear 17 are respectively in clearance fit with the side wall of the cylinder body 8 and the inner hole of the bearing 38 embedded in the gland 21, the axial position is fixed, the rotating motor 20 is arranged in the gland 21 and is connected with the bevel gear 19 through a motor shaft, the circumference direction of the transposition gear driving wheel 40 is provided with straight teeth in arc arrangement, the continuous wide teeth 45 are followed by continuous narrow teeth 46, the narrow teeth 46 are arranged along one side of the transposition gear driving wheel 40, the number of the wide teeth 45 is M, the number of the narrow teeth 46 is N, the transposition gear driven wheel 33 and the meshed secondary reduction gear driving wheel 39 are both provided with straight teeth, the tooth width of the secondary reduction gear driving wheel 39 is larger than the tooth width of the transposition gear driven wheel 33 so as to ensure that the transposition gear 16 can still be meshed with each other after being switched positions, the position block 26 is fixed at the position of one side end surface of the transposition gear driving wheel 40 radially close to the outer edge, the position block 26 is strip-shaped and is perpendicular to the end face of the transposition gear driving wheel 40, the shell of the position block 26 is made of non-magnetic conductive material, a strip groove is formed along the axial direction, the distance between one end of the groove and the end face of the gear is S, a strip-shaped block-shaped permanent magnet 42 is embedded in the strip groove, the angle between the connecting line of one end face of the permanent magnet 42 and the axis of the transposition gear shaft 31 and the central line of the first tooth of the transposition gear driving wheel 40 is alpha, a Hall sensor 49 is fixed on the side wall of the cylinder body 8, when the transposition gear 16 drives the permanent magnet 42 to rotate to a position near the end face of the Hall sensor 49, the radial gap is d, the permanent magnet 42 triggers the Hall sensor 49 to send a signal to an electric control unit, the axial length of the permanent magnet 42 is required to ensure that the two axial working positions of the transposition gear 16 can trigger the Hall sensor 49 to send a signal when the transposition gear 16 drives the permanent magnet 42 to rotate to a position near the end face of the Hall sensor 49, the two ends of the transposition gear shaft 31 are respectively in clearance fit with the side wall of the cylinder body 8 and the inner holes of the bearing 38 embedded in the gland 21, the linear motor 30 is fixed on the outer side of the gland 21, the push rod 41 is coaxial with the transposition gear shaft 31, when one end of the transposition gear shaft 31 is in contact with the limit sliding block 37 under the action of the return spring 36 in the assembling state, the other end extends out of the outer wall of the gland 21 for L, and the clearance between the other end and the end face of the push rod 41 is K, so that the transposition gear 16 is not subjected to axial force in the assembling state, and the baffle cover 35 is fixedly arranged on the outer side of the side wall of the cylinder body 8 and is coaxial with the transposition gear shaft 31. The limit slide block 37, the return spring 36 and the baffle cover 35 are sequentially axially contacted, the step 34 is arranged in the baffle cover 35, the limit slide block 37 can axially slide in the limit cavity of the baffle cover 35, the distance between the limit slide block 37 and the step 34 is P, and P is larger than L in the assembled state, so that the axial force applied to the shift gear 16 after switching the working positions is only the resistance of the return spring 36, the friction resistance when the shift gear shaft 31 rotates is reduced, the cylinder body 8 is provided with a notch 15 at the meshing position of the rack 14 and the shift gear driving wheel 40, the width is such that the meshing movement of the shift gear 16 at the two working positions can be accommodated without interference, the end of the cylinder body 8 is provided with a liquid inlet II 24 and a liquid outlet 23, a one-way valve 25 is arranged between the liquid inlet II 24 and the liquid storage tank 28, a temperature sensor 29 is arranged in the liquid storage tank 28, a one-way valve 22 is arranged between the liquid outlet 23 and the high-pressure energy accumulator, a liquid inlet I5 is arranged between two leather cup grooves of the cylinder body 8, the direction of the liquid inlet is vertical upwards, a plurality of axial shallow grooves 51 are uniformly distributed in the front cavity 27 of the cylinder body 8 along the circumference of the inner wall, the structure of the two-side liquid inlet is beneficial to timely supplementing brake liquid under the effect of vacuum suction, the tooth number of the rack 14 is equal to the sum of the tooth numbers of the narrow teeth 46 and the wide teeth 45, the main leather cup 4 is a leather cup with E-shaped cross section, and the E-shaped opening faces the pressure building side.
The model of the brake fluid is selected in advance according to the design requirement of the brake-by-wire system of the automobile, and the threshold temperature A is set. The contact switch 13 is set to be opened when contacting with the tail end of the piston 7 and closed when separating from the tail end of the piston 7. When the electric pump is not in operation, one end of the piston 7 is contacted with the end face of the end cover assembly 10 under the action of the piston return spring 1. The first tooth of rack 14 is just in a position where the first tooth of the pitch gear drive wheel 40 can be properly engaged. When the accumulator pressure or accumulator brake fluid volume is below a predetermined demand, the temperature of the brake fluid sensed by the temperature sensor 29 in the reservoir 28 is compared to a threshold temperature A.
In the first case, the electronic control unit detects that the temperature of the brake fluid is higher than the threshold temperature a.
Is divided into three steps
Step one: the electronic control unit detects the state of the contact switch 13:
1. the contact switch 13 is closed, the rotary motor 20 and the linear motor 30 are not electrified, and the electric control unit sends an alarm signal to the driver to warn the abnormal operation of the electric pump.
2. The contact switch 13 is turned off, the electronic control unit sends out a command, the linear motor 30 is not electrified, and at the moment, the side, with the narrow teeth 46, of the transposition gear is positioned at a meshing position with the rack 14 under the action of the return spring in the assembled state. The rotary electric machine 20 is energized.
Step two: the gear set reducing mechanism drives the transposition gear driving wheel 40 to rotate, a first tooth on one side with a narrow tooth 46 is meshed with a first tooth of the rack 14, the piston 7 moves forwards, the tail end of the piston 7 is separated from the end part of the end cover assembly 10, and the state of the contact switch 13 is switched to be closed. The brake fluid in the front cavity 27 builds up primary pressure, the fluid inlet II 24 and the one-way valve 25 are closed, and the main leather cup 4 expands and seals towards the reverse direction of the E-shaped opening under the action of brake hydraulic pressure. The transposition gear driving wheel 40 is continuously meshed with the rack 14, the piston 7 is continuously moved forwards, and high-pressure brake fluid enters the high-pressure accumulator through the liquid outlet 23 and the one-way valve 22. After the transposed gear drive wheel 40 is disengaged from the last pair of teeth of the rack 14, the piston 7 moves rearward under the action of the piston return spring 1. The liquid outlet 23 one-way valve 22 is closed, the brake liquid opens the liquid inlet II 24 one-way valve 25 under the action of vacuum suction, the brake liquid enters the front cavity 27 from the liquid storage tank 28, the main leather cup 4 contracts under the action of vacuum suction, and the brake liquid enters the front cavity 27 through a gap between the liquid inlet 2 and the cylinder body 8, which is generated by elastic deformation of the main leather cup 4. The piston 7 continues to move backwards. When the transposed gear 16 rotates to a position where the first tooth center line of the transposed gear driving wheel 40 is meshed with the first tooth of the rack 14 and a beta angle is still formed (under the condition that tooth striking does not occur, the beta angle is as small as possible), the permanent magnet 42 triggers the hall sensor 49 to send a signal to the electronic control unit, and the electronic control unit starts to detect the state of the contact switch 13 after receiving the signal:
1. if the motor is disconnected, keeping the rotating motor 20 electrified, and repeating the step two;
2. if it is closed, the rotary motor 20 is powered off, and the electric control unit sends an alarm signal to the driver to warn the electric pump of abnormal operation.
Step three: when the accumulator pressure or the accumulator brake fluid volume reaches a predetermined requirement, one of the following conditions is satisfied, the rotating electrical machine 20 is powered off.
1. The contact switch 13 is in an open state.
2. When the hall sensor 49 is triggered again.
And in the second case, the electronic control unit detects that the temperature of the brake fluid is lower than the threshold temperature A.
Is divided into three steps
Step one: the electronic control unit detects the state of the contact switch 13:
1. the contact switch 13 is closed, the rotary motor 20 and the linear motor 30 are not electrified, and the electric control unit sends an alarm signal to the driver to warn the abnormal operation of the electric pump.
2. The contact switch 13 is turned off, the electric control unit sends out an instruction, the linear motor 30 is electrified, and the push rod 41 of the linear motor 30 pushes the transposition gear shaft 31 to move for a distance L, so that the position of the transposition gear driving wheel 40 is transposed to a position where only the wide teeth 45 can be meshed with the rack 14. The rotary electric machine 20 is then energized.
Step two: the gear set reduction mechanism rotates the transposed gear drive wheel 40 with the first tooth on the side without the narrow teeth 46 engaged with the first tooth of the rack 14, beginning a process similar to step two in case one. When the transposition gear 16 rotates to the position where the first tooth center line of the transposition gear driving wheel 40 is meshed with the first tooth of the rack 14 by an angle beta, the permanent magnet 42 triggers the Hall sensor 49 to send a signal to the electric control unit, and the electric control unit detects the state of the contact switch 13:
1. if it is off, the rotary electric machine 20 is kept energized, and the linear electric machine 30 is kept energized. Repeating the second step;
2. if so, the rotary motor 20 is de-energized, and then the linear motor 30 is de-energized, and the index gear 16 returns to its original position under the influence of the return spring 36. The electric control unit sends an alarm signal to the driver to warn the abnormal operation of the electric pump.
Step three: when the accumulator pressure or accumulator brake fluid volume reaches a predetermined requirement, one of the following conditions is satisfied, the rotary electric machine 20 is de-energized, then the linear electric machine 30 is de-energized, and the index gear 16 returns to the original position under the action of the return spring 36.
1. The contact switch 13 is in an open state.
2. When the hall sensor 49 is triggered again.
The working principle of the invention is as follows: the viscosity of the brake fluid is mainly related to the type and temperature of the brake fluid. When the model is selected, the lower the temperature, the higher the viscosity of the brake fluid and the worse the fluidity. The brake fluid type is selected according to the design requirement of the automobile brake-by-wire system in advance, the threshold temperature A is set, when the brake fluid temperature is higher than the threshold temperature A, one side with more teeth of the transposition gear is meshed with the rack, so that the compression stroke of the electric pump is longer, the electric pump works with higher efficiency, the viscosity of the brake fluid is lower at the moment, and the front cavity can be timely supplemented when the piston returns. When the temperature of the brake fluid is lower than the threshold temperature A, the linear motor push rod pushes the transposition gear to axially move, one side of the transposition gear with smaller tooth number is meshed with the rack, the compression stroke of the electric pump is shortened, the efficiency is reduced, and the brake demand of the automobile brake-by-wire system can be met. Although the viscosity of the brake fluid is higher at this moment, the brake fluid needed to be supplemented each time is reduced, and meanwhile, the return time of the piston is prolonged, the brake fluid can still supplement the front cavity in time, and the stable output high-pressure brake fluid of the electric pump is ensured. The reasonable parameters such as the number M of wide teeth, the number N of narrow teeth, the angle of a position block, the position of a Hall sensor, the resistance of a piston return spring, the hardness of a leather cup, the diameter of the piston and the like are determined by technical means such as test matching, and under the premise of improving the efficiency of the electric pump for outputting high-pressure hydraulic fluid as much as possible, the piston can return to the assembly position before the first tooth of the transposition gear driving wheel is meshed with the first tooth of the rack when most working conditions are ensured. In order to avoid tooth striking phenomenon in extremely special conditions, a position block with a strip-shaped permanent magnet is arranged at a proper position of the end face of the transposition gear, a Hall sensor is arranged on a gland, and a contact switch is arranged on the end face of an end cover assembly. When the electric pump works, the electric control unit detects the related signals and judges whether the piston is reset when the first tooth of the transposition gear driving wheel is to be meshed with the first tooth of the rack, if the piston is not reset, the risk of tooth beating is indicated, the electric control unit immediately cuts off the rotating motor, and an alarm signal is sent to a driver.
Claims (1)
1. An electric pump for an automotive brake-by-wire system, characterized in that: in the electric pump, a guide sleeve is in interference fit with an inner hole of a cylinder body, one axial end is in contact with a limit step of the inner hole of the cylinder body, the inner hole of the guide sleeve is a cylindrical surface, axial guide rail through grooves are symmetrically formed in two sides of the cylindrical surface, an axial rack through groove is formed in the bottom of the cylindrical surface, one end of a piston is a sealed cylindrical surface, one end of the piston is a guide part, the diameter of the sealed cylindrical surface is larger than that of the guide part, an auxiliary leather cup is sleeved with the sealed cylindrical surface of the piston, strip-shaped convex guide rails are symmetrically formed in two axial sides of the cylindrical surface of the guide part, racks are axially arranged at the bottom of the guide part, the piston is in clearance fit with a main hole of the cylinder body, the guide part is in clearance fit with the inner hole of the guide sleeve, the guide rail through groove is in clearance fit with the guide rail so as to ensure that the piston slides axially in the guide sleeve, the eccentric wear of the piston and the inner hole of the cylinder body is avoided, an outward flanging is formed at one end of the spring limit sleeve, the other end is in contact with the bottom end surface of the cylinder body, and the other end is in radial clearance fit with the guide post, one end of the guide post is riveted with a limit retainer ring, a through hole is arranged on the side wall of a spring limit sleeve, one end of a piston return spring is contacted with a flanging of the spring limit sleeve, one end of the piston return spring is contacted with the piston, a rack is in clearance fit with a through groove of the rack, a clearance is reserved between the top of the rack and the bottom surface of the through groove of the rack, an end cover assembly is fixedly connected with one end of an inner hole of a cylinder body, a clearance is reserved between the end cover assembly end surface and the end surface of the guide sleeve, a contact switch is arranged at the contact surface of the end cover assembly and the tail end of the piston in the assembled state, a vent plug with dustproof and waterproof effects is fixedly arranged at the other end of the end cover assembly, the through hole is communicated with the inner hole of the cylinder body, a gear set reducing mechanism is meshed by four gears, a motor shaft bevel gear, a primary reducing gear, a secondary reducing gear and a transposition gear are sequentially in clearance fit with the side wall of the cylinder body and the inner hole of a bearing embedded in the gland respectively, the axial position is fixed, the rotating motor is arranged in the gland and is connected with the bevel gear through the motor shaft, the circumferential direction of the transposition gear driving wheel is provided with straight teeth in arc arrangement, the continuous wide teeth are provided with continuous narrow teeth, the narrow teeth are arranged along one side of the transposition gear driving wheel, the number of the wide teeth is M, the number of the narrow teeth is N, the transposition gear driven wheel and the meshed secondary reduction gear driving wheel are both straight teeth, the width of the driving teeth of the secondary reduction gear is larger than the tooth width of the transposition gear driven wheel so as to ensure that the transposition gear driven wheel can still be meshed with each other after the transposition gear is switched, the position block is fixed at the position, which is in a strip shape and is perpendicular to the end face of the transposition gear driving wheel, the shell of the position block is made of non-magnetic conductive material, a strip groove is arranged along the axial direction, the distance between one end of the groove and the end face of the gear is S, a strip-shaped permanent magnet is embedded in the strip groove, the angle between the connecting line of one end face of the permanent magnet and the axis of the transposition gear shaft and the first tooth center line of the driving wheel of the transposition gear is alpha, the Hall sensor is fixed on the side wall of the cylinder body, when the transposition gear drives the permanent magnet to rotate to the position near the end face of the Hall sensor, the radial clearance is d, the permanent magnet triggers the Hall sensor to send a signal to the electric control unit, the axial length of the permanent magnet ensures that the Hall sensor is triggered to send a signal when the transposition gear drives the permanent magnet to rotate to the position near the end face of the Hall sensor at two axial working positions, the two ends of the transposition gear shaft are respectively in clearance fit with the side wall of the cylinder body and the inner hole of a bearing embedded in the gland, the linear motor is fixed on the outer side of the gland, the push rod is coaxial with the transposition gear shaft, when one end of the transposition gear shaft contacts with the limiting slide under the action of the return spring in the assembled state, the other end extends out of the length of the outer wall of the gland to be L, the gap between the cylinder body and the end face of the push rod is K so as to ensure that the transposition gear is not subjected to axial force in an assembled state, the retaining cover is fixedly arranged on the outer side of the side wall of the cylinder body and is coaxial with the transposition gear shaft, the limiting slide block, the return spring and the retaining cover are sequentially in axial contact, a step is arranged in the retaining cover, the limiting slide block can axially slide in a limiting cavity of the retaining cover, the distance between the limiting slide block and the step is P, P is larger than L so as to ensure that the axial force received after the transposition gear is switched to a working position is only the resistance of the return spring, the friction resistance of the transposition gear shaft is reduced when the transposition gear shaft rotates, the cylinder body is provided with a notch at the meshing position of the rack and the transposition gear driving wheel, the width can accommodate meshing movement of the transposition gear at two working positions and does not interfere, a one-way valve is arranged between the end part of the cylinder body and the liquid inlet II, the temperature sensor is arranged in the liquid storage tank, a one-way valve is arranged between the liquid outlet and the high-pressure accumulator, the liquid inlet I is vertically upwards arranged between the two leather cup grooves of the cylinder body, a plurality of axial shallow grooves are uniformly distributed along the circumference of the inner wall of the cylinder body, the front cavity is beneficial to the structure of the two-side liquid inlet is beneficial to brake liquid, the suction liquid is equal to the number of the tooth faces E and the tooth is narrow, and the tooth number of the tooth is arranged towards the tooth E and the tooth face of the side of the main leather cup is in a narrow shape; selecting a brake fluid model and setting a threshold temperature A; when the temperature of the brake fluid is higher than the threshold temperature A, the side with more teeth of the transposition gear, namely the narrow tooth side, is meshed with the rack; when the temperature of the brake fluid is lower than the threshold temperature A, the linear motor push rod pushes the transposition gear to axially move, and one side of the transposition gear with fewer teeth, namely one side with wide teeth, is meshed with the rack.
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| CN201710336197.XA CN107117152B (en) | 2017-05-12 | 2017-05-12 | Electric pump for automobile line control braking system |
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| CN201710336197.XA CN107117152B (en) | 2017-05-12 | 2017-05-12 | Electric pump for automobile line control braking system |
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| CN107117152A CN107117152A (en) | 2017-09-01 |
| CN107117152B true CN107117152B (en) | 2023-04-21 |
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| CN201710336197.XA Active CN107117152B (en) | 2017-05-12 | 2017-05-12 | Electric pump for automobile line control braking system |
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| CN107673251B (en) * | 2017-11-10 | 2023-06-30 | 中国海洋大学 | But automatically regulated's marine seismic exploration towrope winch |
| CN112645197B (en) * | 2020-11-27 | 2022-06-14 | 日立电梯（中国）有限公司 | Prevent bubble water diversion sheave convenient to control |
Family Cites Families (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3785449A (en) * | 1971-08-27 | 1974-01-15 | Rockwell International Corp | Self-contained power transmitting assembly |
| US5094079A (en) * | 1987-10-22 | 1992-03-10 | Automotive Products Plc | Master cylinder assembly |
| JP3496549B2 (en) * | 1998-04-17 | 2004-02-16 | トヨタ自動車株式会社 | Hydraulic brake device |
| JP4193551B2 (en) * | 2003-04-03 | 2008-12-10 | 日産自動車株式会社 | Brake device stroke simulator |
| KR101373950B1 (en) * | 2006-07-11 | 2014-03-12 | 콘티넨탈 테베스 아게 운트 코. 오하게 | Motor vehicle brake system having a low pressure accumulator |
| FR2933934B1 (en) * | 2008-07-17 | 2011-01-14 | Bosch Gmbh Robert | HYDRAULIC BRAKE ASSIST SERVOMOTOR COMPRISING AN ENGINE |
| WO2011061808A1 (en) * | 2009-11-20 | 2011-05-26 | トヨタ自動車株式会社 | Brake device |
| CN102108965A (en) * | 2009-12-24 | 2011-06-29 | 上海航天汽车机电股份有限公司传感器分公司 | Master cylinder of hydraulic pump for automobile clutch |
| JP5882066B2 (en) * | 2012-01-19 | 2016-03-09 | 日立建機株式会社 | Control device for work vehicle |
| DE102012223714A1 (en) * | 2012-12-19 | 2014-06-26 | Robert Bosch Gmbh | Method for checking a separating valve and monitoring device for a separating valve |
| KR101567842B1 (en) * | 2014-09-12 | 2015-11-11 | 현대모비스 주식회사 | Brake device for vehicle |
| CN105539410B (en) * | 2015-12-30 | 2017-12-26 | 吉林东光奥威汽车制动系统有限公司 | A kind of brake system of car active boost device |
| CN106427960A (en) * | 2016-11-04 | 2017-02-22 | 吉林东光奥威汽车制动系统有限公司 | Compensation hole and center valve type brake master cylinder opening sealing structure |
| CN206797366U (en) * | 2017-05-12 | 2017-12-26 | 吉林东光奥威汽车制动系统有限公司 | A kind of automobile line control brake system electrodynamic pump |
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