CN219192171U - Electronic booster rollback protection device - Google Patents

Abstract

The utility model discloses a rollback protection device of an electronic booster, which is provided with a shell and a guide screw rod which is arranged in the shell and can stretch out and draw back, wherein an energy-absorbing and damping device is fixed at the bottom of the shell, the energy-absorbing and damping device is a rubber pad with an annular structure, the outline of the outer edge of the energy-absorbing and damping device is completely attached to and fixed on the inner wall of the bottom of the shell, and the aperture of a central round hole of the annular structure is smaller than the outer diameter of the guide screw rod. The protection device achieves the protection effect through energy absorption and shock absorption, and the guide screw is prevented from being directly contacted with the bottom of the shell to be hard to collide with the bottom of the shell when retreating, so that abnormal sound caused by impact of mechanical parts is effectively avoided, the integral failure of the product caused by durable impact fatigue of the product is prevented, meanwhile, the driving feeling of a driver is prevented from being weakened, and the mechanical kinetic energy can be stored through the energy absorption and shock absorption device to serve as initial power for secondary braking.

Description

Electronic booster rollback protection device

Technical Field

The utility model relates to the field of automobile electronic boosters.

Background

Because the electronic booster has many advantages over the vacuum booster, along with the popularization of electric vehicles, the vacuum booster has the potential of being gradually replaced by the electronic booster, and the electronic booster is various in the prior art, and force transmission mechanisms are various, and most commonly three kinds of force transmission mechanisms are adopted. Some are worm-gear screw-rack type force transmission, some are transmitted through a gear screw sleeve (for example, bosch second generation), and others are transmitted through a roller screw.

Along with the slow depression of a brake pedal, the whole vehicle braking process starts, a displacement sensor is driven by a push rod to move forward for a certain displacement, an ECU (electronic control unit) receives a displacement signal and then sends a corresponding instruction to a motor to rotate, a motor gear transmits torsion force to a primary reduction gear of a booster, the primary reduction gear transmits force to a secondary reduction gear of the booster, the secondary reduction gear changes circumferential force into axial force through a guide screw (only axial movement is allowed by axial limit of the guide screw) in a screw sleeve, the guide screw or other mechanisms connected with the guide screw can directly or indirectly push a main cylinder piston forward, and brake fluid in the main cylinder is compressed to build a braking system.

When the brake pedal is released for pressure relief, the displacement sensor quickly returns to a mechanical zero point along with the return of the pedal. At the moment, the brake master cylinder is also reset under the action of the master cylinder spring and high-pressure liquid, meanwhile, the guide support of the booster pushes the guide screw back to the mechanical zero point position under the action of the booster return large spring, the process ECU can read a sensor displacement signal to give a reverse instruction to the motor, at the moment, the force exerted by the reverse rotation of the motor also acts on the guide screw, which is equivalent to accelerating the return of the guide screw to the mechanical zero point, and the guide screw suddenly stops when contacting with the bottom of the booster shell, so that the extremely large impact force can be generated.

The power assisting mechanism of the existing electronic booster returns to an original zero position under the action of a return large spring, namely the original zero position, wherein the zero is not a working zero point and is divided into a mechanical zero point and a working zero point. The mechanical zero point is a stress balance point position reached after each part of the product is assembled, the working zero point is also called a calibration zero point, the mechanical part is stopped at an optimal initial working position through human design intervention, and abnormal sound can occur because the guide screw of the booster is hard and hard between metals when the guide screw is retracted to the bottom of the shell and contacts with the bottom of the shell, so that a manufacturer adds a plastic block on the lower side of the guide bracket or adds a plastic block or a spring on the bottom of the shell. An experiment has been performed in which rubber blocks of a certain thickness are added to the lower side of the guide bracket and the bottom of the housing, respectively, but the system fails by several tens of impacts to the rubber blocks without a rollback protection strategy, followed by a sharp impact sound. The method is also capable of treating the symptoms and the root causes, the mechanical zero position is gradually changed along with the abrasion of the rubber block, and finally, a negative value is caused between the motor corner position and the original calibration position.

In addition, under the extreme AEB working condition, the pressure relief reaction force of the brake system is simultaneously added and held, a driver can obviously feel that the pedal is quickly jacked, and at the moment, the force transmission mechanism in the booster can be damaged instantaneously by the maximum reaction force of the mechanical part.

Therefore, manufacturers may add respective software rollback protection strategies for different vehicle types, namely when the rollback of the lead screw approaches a mechanical zero point, and when the rotation angle of the motor approaches a calibration zero point, the motor applies a forward moment to offset the rollback acceleration. The condition that the working conditions are different and the retractive force is different is actually not perfectly controlled, the forward moment needs to be correspondingly adjusted according to the magnitude of the retractive force, and in addition, if the power failure condition of the booster ECU is met, the retractive protection effect is completely lost, and the mechanical parts are still in hard contact.

Therefore, the impact problem in the rollback process of the electronic booster cannot be reliably solved in the prior art, and an effective rollback protection device is lacked.

Disclosure of Invention

The utility model aims to realize a protection device for solving the impact problem in the backspacing process of an electronic booster.

In order to achieve the above purpose, the technical scheme adopted by the utility model is as follows: the utility model provides an electronic booster falls back protection device, electronic booster is equipped with the casing and sets up the lead screw that can stretch out and draw back in the casing, the bottom of casing is fixed with energy-absorbing damping device, energy-absorbing damping device is annular structure's rubber pad, energy-absorbing damping device's outer edge profile laminating completely and fix on the inner wall of casing bottom, annular structure's central round hole's aperture is less than the external diameter of lead screw.

A circle of circular energy absorption channels are arranged in the annular structure.

Metal sheets are arranged in the energy absorption channels at intervals, and the metal sheets divide the energy absorption channels into cavities at equal intervals.

The metal sheet is Z-shaped or I-shaped, the metal sheet is integrally embedded in the energy absorption and shock absorption device, and the vertical part in the middle of the metal sheet is provided with an energy absorption channel at intervals.

The metal sheet is a metal sheet with elasticity.

The electronic booster is provided with a motor for building pressure, a gear of the motor is meshed with a primary gear to transfer force to a primary reduction gear, the primary reduction gear is meshed with a secondary gear to transfer force to the secondary reduction gear, the secondary reduction gear and a screw sleeve are integrated, the screw sleeve is meshed with a guide screw to change circumferential force into axial force, and the guide screw or other connecting mechanisms directly or indirectly push a master cylinder piston to build pressure of a braking system.

The automobile pedal provided with the electronic booster is provided with a displacement sensor, and the displacement sensor senses the pedal travel position and transmits a displacement signal to the ECU.

The protection device achieves the protection effect through energy absorption and shock absorption, and the guide screw is prevented from being directly contacted with the bottom of the shell to be hard to collide with the bottom of the shell when retreating, so that abnormal sound caused by impact of mechanical parts is effectively avoided, the integral failure of the product caused by durable impact fatigue of the product is prevented, meanwhile, the driving feeling of a driver is prevented from being weakened, and the mechanical kinetic energy can be stored through the energy absorption and shock absorption device to serve as initial power for secondary braking.

Drawings

The contents of each drawing in the specification of the present utility model are briefly described as follows:

FIG. 1 is a schematic diagram of an energy absorbing and shock absorbing device;

FIG. 2 is a cross-sectional view A-A of FIG. 1;

FIG. 3 is a schematic cross-sectional view of an energy absorbing and shock absorbing device;

the labels in the above figures are: 1. an energy-absorbing and shock-absorbing device; 2. an energy absorbing channel; 3. a metal sheet.

Detailed Description

The following detailed description of the embodiments of the utility model, such as the shape and construction of the components, the mutual positions and connection relationships between the components, the roles and working principles of the components, the manufacturing process and the operating and using method, etc., is provided to assist those skilled in the art in a more complete, accurate and thorough understanding of the inventive concept and technical solution of the present utility model.

When the booster builds up pressure in the forward direction, the motor rotates in the forward direction, the motor gear is meshed with the primary gear to transmit force to the primary reduction gear, the primary reduction gear is meshed with the secondary gear to transmit force to the secondary reduction gear, the secondary reduction gear and the threaded sleeve are integrated, the threaded sleeve is meshed with the guide screw to change circumferential force into axial force, and the guide screw or other connecting mechanisms directly or indirectly push the main cylinder piston to build up pressure in the braking system.

When the pressure is released, the displacement sensor quickly returns to the original position along with the return of the pedal. At the moment, the brake master cylinder also returns under the action of the master cylinder spring and high-pressure liquid, the guide bracket pushes the lead screw back to the mechanical zero point position under the action of the booster return large spring, at the moment, the ECU can read the sensor signal, the motor reversely rotates to apply force on the guide or screw rod, the prior art can adopt the ECU to provide a force release protection for the lead screw, namely, the lead screw returns to the mechanical zero point under the double actions of the return large spring force and the pressure release force, when the lead screw and the shell bottom are in the process of being in close contact, the lead screw is used as the first safety through the rollback protection limit of peripheral software, and through theoretical calculation, the forward moment of the motor and the displacement sensor is gradually increased when approaching to the calibration zero point in the rollback process of the lead screw is detected, and most rollback force is counteracted.

In addition, the utility model also increases double insurance, and the energy-absorbing and shock-absorbing device 1 is added at the bottom of the shell to absorb redundant kinetic energy, so that the energy-absorbing and shock-absorbing device 1 can completely absorb redundant kinetic energy even if the booster system is occasionally powered off, thereby playing a double insurance role.

As shown in figures 1-3, the energy-absorbing and damping device 1 is an annular rubber pad, the thickness is generally larger, the energy-absorbing and damping device 1 is arranged between the guide screw and the bottom of the shell, the energy-absorbing and damping device 1 has the functions of a damper or an energy accumulator, the energy-absorbing and damping device 1 is contacted with the bottom of the shell and fixed together, the shape of the energy-absorbing and damping device can be adjusted to be a cylindrical rubber body with a hollow outline according to the shape of the bottom of the shell, the aperture of a central round hole of the annular structure is smaller than the outer diameter of the guide screw, the guide screw can be supported before the guide screw impacts the bottom of the shell, a circle of circular energy-absorbing channel 2 is arranged in the annular structure, and the hollow middle part of the rubber is used for absorbing energy and damping when the rubber is extruded. In order to further increase the reliability of the energy-absorbing and shock-absorbing device 1, the multi-layer metal sheet 3 is vulcanized in the energy-absorbing and shock-absorbing device to avoid damage caused by long-term impact, the metal sheet 3 is used for spacing the energy-absorbing channels 2 into equidistant cavities, the metal sheet 3 is required to be arranged according to the requirement, and an elastic metal sheet is required to be adopted to provide a sufficient rebound effect, in addition, the metal sheet 3 is Z-shaped or I-shaped, so that the contact area between the upper part and the lower part of the metal sheet 3 embedded in the energy-absorbing and shock-absorbing device 1 and a rubber part is large, the situation that the metal sheet 3 is split into the energy-absorbing and shock-absorbing device 1 is avoided, the vertical part in the middle of the metal sheet 3 is separated from the energy-absorbing channels 2, the energy-absorbing and shock-absorbing device 1 is separated from a guide screw, and is in most working state, and only is fit for energy absorption when the retraction is limited.

The energy absorption and shock absorption device 1 reduces the durable failure of products, improves the driving feel of a driver, and can store part of energy. The middle part is vulcanized with the hollow rubber body of the multilayer metal sheet 3, the metal sheet 3 is added to increase the structural strength, the hollow part of the rubber is used for absorbing energy and giving way to the extrusion deformation of the rubber, and the rubber and the hollow design can make great contribution to shock absorption.

While the utility model has been described above with reference to the accompanying drawings, it will be apparent that the utility model is not limited to the above embodiments, but is capable of being modified or applied directly to other applications without modification, as long as various insubstantial modifications of the method concept and technical solution of the utility model are adopted, all within the scope of the utility model.

Claims (7)

1. The utility model provides an electronic booster falls back protection device, electronic booster is equipped with the casing and sets up the lead screw that can stretch out and draw back in the casing, its characterized in that: the bottom of the shell is fixedly provided with an energy-absorbing and damping device, the energy-absorbing and damping device is a rubber pad with an annular structure, the outline of the outer edge of the energy-absorbing and damping device is completely attached to and fixed on the inner wall of the bottom of the shell, and the aperture of a central round hole of the annular structure is smaller than the outer diameter of a lead screw.

2. The electronic booster rollback protection apparatus of claim 1, wherein: a circle of circular energy absorption channels are arranged in the annular structure.

3. The electronic booster rollback protection apparatus of claim 2, wherein: metal sheets are arranged in the energy absorption channels at intervals, and the metal sheets divide the energy absorption channels into cavities at equal intervals.

4. The electronic booster rollback protection apparatus of claim 3, wherein: the metal sheet is Z-shaped or I-shaped, the metal sheet is integrally embedded in the energy absorption and shock absorption device, and the vertical part in the middle of the metal sheet is provided with an energy absorption channel at intervals.

5. The electronic booster rollback protection apparatus of claim 4, wherein: the metal sheet is a metal sheet with elasticity.

6. The electronic booster rollback protection apparatus according to any one of claims 1 to 5, characterized in that: the electronic booster is provided with a motor for building pressure, a gear of the motor is meshed with a primary gear to transfer force to a primary reduction gear, the primary reduction gear is meshed with a secondary gear to transfer force to the secondary reduction gear, the secondary reduction gear and a screw sleeve are integrated, the screw sleeve is meshed with a guide screw to change circumferential force into axial force, and the guide screw directly or indirectly pushes a master cylinder piston to forward for building pressure of a braking system.

7. The electronic booster rollback protection apparatus of claim 6, wherein: the automobile pedal provided with the electronic booster is provided with a displacement sensor, and the displacement sensor senses the pedal travel position and transmits a displacement signal to the ECU.

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