JP2021109649A - Separate type electric brake booster - Google Patents

Abstract

To provide an improved electric brake booster in which when operating motor brake, a pedal stepping force transmission element and a brake pedal are not interlocked since a brake assist force transmission line of the brake pedal is separated from the pedal stepping force transmission element.SOLUTION: A vehicle electric brake booster includes: a pedal stepping force transmission mechanism which is driven by a brake pedal to move in an axial direction; a detector for detecting operation of the pedal stepping force transmission mechanism; a brake motor which generates brake assist force by execution of a motor brake operation; and an assist force transmission mechanism which is driven by the brake motor to move in an axial direction, thereby transmitting brake assist force generated by the brake motor to a piston of a brake master cylinder. In a motor brake operation mode, the assist force transmission mechanism is kinematically separated from the pedal stepping force transmission mechanism, and further, input of the electric brake booster is configured by only brake assist force generated by the brake motor.SELECTED DRAWING: Figure 1

Description

The present application relates to an electric brake booster used in a vehicle brake system, of which the brake motor has an independent braking assist force transmission line separated from the pedal pedal force transmission line.

Many vehicles have additional brake boosters in their hydraulic braking system. The brake booster usually includes a vacuum booster and an electric booster. The vacuum booster uses the vacuum in the intake pipe of the engine as a brake assist source, and the electric booster uses the motor as a brake assist source.

In a conventional electric booster, the braking assist force and the pedal pedal force usually have a combined transmission line, that is, they are transmitted to the piston of the brake master cylinder via a general-purpose force transmission element. When the driver performs a braking operation on such an electric booster, when the driver depresses the brake pedal to apply the pedal pedaling force, a braking assist force is generated in the motor of the electric booster and the pedal is used. The pedaling force and the braking assist force are combined and transmitted to the piston of the brake master cylinder. When the vehicle automatically brakes a vehicle equipped with an automatic braking function (for example, automatic driving or an active braking module), the electric double is applied without the intervention of the driver (that is, there is no input of pedal force). The motor of the force device actively generates a braking assist force. However, when the braking assist force generated by the motor is transmitted to the piston of the brake master cylinder, the pedal pedal force transmitting element is also interlocked, and in some cases, the brake pedal may also be interlocked. Not only does this affect the transmission efficiency of the braking assist force, but it may also cause discomfort to the driver who rests his foot on the brake pedal.

The gist of the present application is that the brake assist force transmission line of the brake motor is separated from the pedal pedal force transmission element when the motor braking operation is performed, so that the pedal pedal force transmission element and the brake pedal are not interlocked. It is in place to provide an improved electric brake booster.

Therefore, according to one embodiment of the present application, a separate electric brake booster used in a vehicle brake system is provided, and is arranged to be suitable for being driven by a brake pedal and moving in the axial direction. A brake that is arranged to detect the operation of the pedal pedal force transmission mechanism, a detection device that is arranged to detect the operation of the pedal depression force transmission mechanism, and a brake that is arranged to generate a braking assist force by executing a motor braking operation. It includes a motor and an assist force transmission mechanism that is arranged to be suitable for transmitting the braking assist force generated by the brake motor to the piston of the brake master cylinder by moving in the axial direction driven by the brake motor. In the motor braking operation, the assist force transmission mechanism is kinematically separated from the pedal pedal force transmission mechanism, and the input of the electric brake booster is configured only by the braking assist force generated by the brake motor.

According to the present application, when the motor braking operation is executed, the braking assist force transmission line of the brake motor of the electric brake booster is separated from the pedal pedal force transmission line. Since the operation of the braking assist force transmitting element does not interlock the pedal pedaling force transmitting element and the brake pedal, it is possible to avoid giving the driver discomfort from the brake pedal. Further, when the brake motor is operated, the input of the electric brake booster is derived only from the brake motor and is not combined with the pedal depression force.

The separate electric brake booster of the present application can replace the conventional vacuum booster.

It is a schematic cross-sectional view (passing through the central axis of the booster) of the separate type electric brake booster of the possible embodiment of this application. It is a schematic cross-sectional view of the electric brake booster in the other direction (passing through the central axis of the booster in the direction orthogonal to FIG. 1). It is the schematic for demonstrating the pedal pedaling force transmission line in the electric brake booster. It is the schematic for demonstrating the braking assist force transmission line in an electric brake booster. It is the schematic of the drive nut in the electric brake booster. It is the schematic of the plunger in the electric brake booster. It is the schematic of the pedal spring in the electric brake booster. It is the schematic of the component in the possible embodiment of the pedal spring regulation structure in the electric brake booster. It is the schematic of the component in the possible embodiment of the pedal spring regulation structure in the electric brake booster. It is a schematic diagram of another possible embodiment of a pedal spring regulation structure in an electric brake booster. It is the schematic of the initial stage in the normal braking operation of an electric brake booster. It is the schematic of the pressurization stage in the normal braking operation of an electric brake booster.

Hereinafter, a plurality of possible embodiments of the present application will be described with reference to the drawings. It should be pointed out that the drawings are merely to represent the principles of the present application and not to the actual structure of the present application. Therefore, the drawings are not drawn according to the ratio. Moreover, some details have been deformed or omitted for clarity.

First of all, it should be pointed out that in the present application, the "rear side" is kinematically closer to the brake pedal of the vehicle, and the "front side" is kinematically closer to the brake pedal, that is, closer to the brake master cylinder. It means that it is on the side of.

As shown in FIGS. 1 and 2, the separate electric brake booster used in the vehicle brake system according to the possible embodiment according to the present application outputs an output to the piston 2 of the brake master cylinder 1 of the vehicle hydraulic brake system. Used to convey. See FIGS. 3-10 for details of the partial structure of the electric brake booster. FIGS. 1 and 2 show the initial position (non-operating state) of the electric brake booster.

The piston 2 is movable in the axial direction with respect to the cylinder body of the brake master cylinder 1. Since the brake master cylinder 1 and its piston 2 of the hydraulic brake system of the vehicle are common in this field, detailed description will not be given. It should be pointed out that the brake master cylinder 1 has a dual piston, the piston 2 shown in the figure is the rear chamber (first chamber) piston of the brake master cylinder 1, and the brake master cylinder. 1 further includes an anterior chamber (second chamber) piston (not shown).

The electric brake booster of the present application is associated with the brake pedal side pusher 3, and also includes a brake motor 4 for generating a braking assist force. The electric brake booster further includes a control means 5 and a pedal stroke sensor 6. The pedal stroke sensor 6 is used to detect the stroke of the pusher 3, that is, to detect the stroke of the brake pedal. The control means 5 can receive the brake pedal stroke signal detected by the pedal stroke sensor 6 and control the operation of the brake motor 4. After receiving the braking signal, the control means 5 activates the brake motor 4 to generate the brake fluid pressure. The braking signal may be a brake pedal stroke signal or a braking signal from the vehicle automatic braking function.

When braking is performed using the brake motor 4, only the braking assist force generated by the brake motor 4 is input to the electric brake booster, and the pedal depression force of the brake pedal is not included in the input. When braking without using the brake motor 4, for example, when the brake motor 4 is not supplied with power or the brake motor 4 is disabled, the pedal pedal force input by the driver through the brake pedal via the pusher 3 is applied. It can be used as an input for the electric brake booster.

The electric brake booster further includes a drive sleeve 11 and a drive nut 12, both of which are arranged coaxially with the piston 2 and thereby limit the central axis of the electric brake booster. The drive sleeve 11 is disposed in the drive nut 12, and there is a screw drive engagement between the drive sleeve 11. The drive nut 12 is rotatably disposed in the booster housing (not shown) via a bearing 13 (and other bearings may be possible). The brake motor 4 drives the rotation of the drive nut 12 via a corresponding drive mechanism (eg, gear assembly). According to a possible embodiment, when the brake motor 4 is charged (the rotor of the motor is rotating or stationary), the brake motor 4 is a drive mechanism (particularly a gear set) with the drive nut 12. Locks the axial position of the drive nut 12 so that the drive nut 12 cannot move in the axial direction. When the brake motor 4 is not charged, the rotor of the motor is rotatable, so that the brake motor 4 releases the axial movement lock function of the drive nut 12, and the drive nut 12 can move in the axial direction. ..

Alternatively, a single lock structure may be provided. When the brake motor 4 is charged, the lock structure locks the drive nut 12 in the axial direction, so that the drive nut 12 does not have the ability to move in the axial direction. On the other hand, when the brake motor 4 is not charged, the lock structure releases the axial movement lock of the drive nut 12 so that the drive nut 12 can move in the axial direction.

When the drive nut 12 is locked in the axial direction, the rotation of the drive nut 12 can be pushed so that the drive sleeve 11 moves in the drive nut 12 in the axial direction.

See FIG. The drive nut 12 is generally tubular, and a part thereof in the axial direction is a screw portion 12a, and an inward-facing screw is provided, and the screw is used to mesh with the external screw of the drive sleeve 11. (The drive sleeve 11 is provided with an external screw over the entire length). Further, the screw portion 12a divides the inner hole of the drive nut 12 into a front portion 12b and a rear portion 12c. The axial length of the threaded portion 12a is about 1/3 or less of the axial length of the drive nut 12. The axial length of the front portion 12b is preferably shorter than that of the rear portion 12c.

Return to FIGS. 1 and 2. A plunger 14 is arranged between the drive sleeve 11 and the piston 2. The driving force generated by the brake motor 4, that is, the braking assist force is transmitted to the drive sleeve 11 via the drive nut 12, and further transmitted from the drive sleeve 11 to the piston 3 via the plunger 14. The plunger 14 and the piston 2 are in direct contact with each other, and the plunger 14 can directly transmit the braking assist force to the piston 2. Alternatively, since a force transmission element (for example, a pushing rod) can be arranged between the plunger 14 and the piston 2, the plunger 14 can transmit the braking assist force to the piston 2 via the force transmission element. Such an arrangement of the force transmitting element can be advantageous in distributing the braking assist force on the piston 2.

See FIG. The plunger 14 has a substantially columnar main body 14a, and a pair of flanges 14b extending in opposite directions in the radial direction are formed at the front end of the main body 14a, and the diameter of the rear portion of the main body 14a is reduced. The small diameter portion 14c is formed. Further, in the main body 14a, a radial through hole (inner chamber) 14d penetrating the main body 14a is formed along the radial direction orthogonal to the radial direction in which the flange 14b extends. The front end of the radial through hole 14d ends at a position near the front end surface of the main body 14a, and the rear end of the radial through hole 14d communicates with the rear end surface of the main body 14a through the axial through hole 14e. A front end wall 14f exists between the front end of the radial through hole 14d and the front end surface of the main body 14a.

The front end of the push rod 15 is connected to the pedal spring 16. The pedal spring 16 includes a combination spring formed by superimposing leaf springs, so that the spring hardness of the pedal spring 16 in the axial direction is gradually increased from the outer end in the longitudinal direction (radial direction) toward the center in the radial direction. Can be made to. See, for example, FIG. The pedal spring 16 includes leaf springs 16a, 16b, 16c which are sequentially stacked in the axial direction. The radial size of each leaf spring gradually decreases from the front side to the rear side in the axial direction.

Return to FIGS. 1 and 2. The front end of the plunger 14 is arranged to be suitable for contacting (directly or indirectly) with the piston 2. The small diameter portion 14c of the plunger 14 is inserted into the front portion 12b of the drive nut 12 so that the plunger 14 can be moved axially with respect to the drive nut 12.

A push rod 15 is arranged in the axial through hole limited by the drive sleeve 11. The front portion of the pusher 3 is connected to the push rod 15. The front end of the push rod 15 extends from the front end of the drive sleeve 11, penetrates the axial through hole 14e of the plunger 14, and is inserted into the radial through hole 14d. The front end of the push rod 15 is further connected to the reaction plate 17 on the front side of the pedal spring 16. The pedal spring 16 and the reaction plate 17 penetrate the radial through hole 14d of the plunger 14 and are exposed from both radial sides of the plunger 14. In the initial position, the reaction plate 17 is located on the rear side of the front end wall 14f of the plunger 14 in the axial direction and is separated from the front end wall 14f by an axial distance.

Both ends of the pedal spring 16 in the radial direction are connected to the regulation rod 18. The regulation rod 18 extends parallel to the central axis of the booster and is restrained by the regulation plate 19 arranged so as to surround the small diameter portion 14c of the plunger 14, so that the regulation rod 18 is bound to the regulation plate 19. Can be reciprocated over a finite axial distance. In the example shown in FIG. 8, the front end of the regulation rod 18 is fixed to the outer end in the longitudinal direction of the pedal spring 16, and a thin rod portion 18a is formed at the rear portion of the regulation rod 18, and the thin rod portion 18a is formed. It is inserted into a through hole 19a in the corresponding radial end of the regulation plate 19 shown in FIG. 9, and is axially movable in the through hole 19a. When the pedal spring 16 is elastically deformed in the axial direction by the pushing force of the push rod 15, the regulating rod is brought into contact with the large diameter portions at both ends of the thin rod portion 18a in the axial direction and the both end faces in the axial direction of the regulating plate 19. The axial movement range of the 18 is limited, that is, the axial movement range of both ends of the pedal spring 16 in the radial direction is limited. Therefore, the regulation rod 18 and the regulation plate 19 form a regulation structure of the pedal spring 16.

It is understandable that other types of pedal spring regulatory elements can also be adopted. For example, FIG. 10 illustrates another type of regulatory structure of the pedal spring 16, of which the front end of the regulatory rod 18 is hinged to the longitudinal outer end of the pedal spring 16 and is of the regulatory rod 18. A hinge pin is provided at the rear end, and the hinge pin is inserted into a guide groove 19a extending in parallel with the axial direction in the regulation plate 19, and the hinge pin can move back and forth in the guide groove 19a. .. In the initial position, the radial distance between the front ends of the two regulating rods 18 and the radial distance between the rear ends of the two regulating rods 18 may be different or the same. When the push rod 15 pushes the pedal spring 16 forward, the hinge pin at the rear end of the regulation rod 18 slides forward in the guide groove 19a. When the hinge pin at the rear end of the regulation rod 18 reaches the bottom of the front groove of the guide groove 19a, the rear end of the regulation rod 18 is restrained and cannot continue to move forward. You will not be able to move further forward. As the push rod 15 pushes the central portion of the pedal spring 16 forward, the pedal spring 16 begins to elastically deform in the axial direction.

The regulating plate 19 is non-rotatable and is held so that its axial position with the drive nut 12 does not change. In other words, the regulation plate 19 can move in the axial direction along with the drive nut 12, but cannot rotate. With an appropriate holding structure, the above-mentioned capacity of the regulation plate 19 can be realized. For example, in the illustrated example, the regulation plate 19 is fixed to the outer ring of the bearing 13.

A spring retainer 20 for pressing the first return spring 21 is mounted on the front side of both radial ends of the reaction plate 17. The first return spring 21 is used to press the push rod 15 backward in the axial direction via the spring retainer 20, the reaction plate 17, and the pedal spring 16. The first return spring 21 can be mounted between the cylinder body of the brake master cylinder 1 and the spring retainer 20.

Further, a second return spring 22 for pressing the plunger 14 backward in the axial direction is mounted between the cylinder body of the brake master cylinder 1 and the flange 14b of the plunger 14. The spring hardness of the second return spring 22 is higher than that of the first return spring 21.

It is understandable that, according to the internal structure of the booster, the first return spring 21 and the second return spring 22 can be arranged at other positions. Further, in the illustrated example, both are in the form of coil compression springs, but other types of springs may be adopted as long as the above-mentioned pressing functions of both can be realized. For example, in the example shown in FIG. 10, the first return spring 21 is a 3D metal wire spring, one end of which is hooked to the outer end of the pedal spring 16 in the longitudinal direction, and the other end of which is fixed to the regulation plate 19. There is. It is understandable that the second return spring 22 may also adopt the form of a 3D metal wire spring.

FIG. 3 schematically depicts a pedal pedal force transmission mechanism (line) in the electric brake booster, of which the pedal pedal force is transmitted to the pedal spring 16 and the reaction plate 17 via the pusher 3 and the push rod 15. Then, the pedal spring 16 and the reaction plate 17 can be moved forward against the first return spring 21. A radial extending portion 17a is mounted or formed on one end of the reaction plate 17 in the radial direction, and the radial extending portion 17a faces the pedal stroke sensor 6 and the radial extending portion 17a is opposed to the pedal stroke sensor 6. Since the axial movement of the pedal stroke sensor 6 can be detected (for example, by a changing magnetic field), the control means 5 can determine the pedal stroke and can determine the intention of the brake by the driver. Become.

FIG. 4 schematically depicts a braking assist force transmission mechanism (line) in the electric brake booster, of which the driving force (braking assist force) of the brake motor 4 includes a drive nut 12 and a drive sleeve 11. Since it is transmitted to the plunger 14 via, the plunger 14 is moved forward against the thrust of the second return spring 22, and the plunger 14 applies the braking assist force generated by the brake motor 4 to the electric brake booster. It is transmitted to the piston 2 as the output of the device.

It should be pointed out that in the illustrated example, the braking assist force is mainly transmitted via the drive nut 12 and the drive sleeve 11. However, it is understandable that other mechanisms that convert rotary motion into linear motion, such as gear rack mechanisms, can be used to transmit the braking assist force here.

It should also be pointed out that the plunger 14, push rod 15, pedal spring 16 and reaction plate 17 are only allowed to move in the axial direction, not to rotate, and these rotation prevention is done by an appropriate restraint structure. It can be realized, for example, by the rotation prevention restraint generated by the regulation rod 18 with respect to the pedal spring 16 via the regulation plate 19 (non-rotatable).

The operation of the electric brake booster will be described below.

First, the normal operation mode of the electric brake booster is described. The so-called normal operation means that the electric brake booster is activated by the action of the driver depressing the brake pedal, and the brake motor 4 provides the braking assist force. As shown in FIG. 11, after the driver depresses the brake pedal, the pusher 3 pushes the pedal spring 16 and the reaction plate 17 axially forward by an idle stroke via the push rod 15. The distance of this idle stroke is determined by the regulation of the regulation plate 19 with respect to the regulation rod 18. For example, this idle stroke is about 5 mm or less. The control means 5 detects the idle stroke by the pedal stroke sensor 6 and confirms that the driver has depressed the brake pedal. Therefore, the control means 5 is activated so that the brake motor 4 rotates in the forward direction and is confirmed. The plunger 14 is driven to move forward at the specified distance. The forward movement of the plunger 14 in this portion causes the piston 2 to move forward into the cylinder body of the brake master cylinder 1 so that the pressure in the cylinder body of the brake master cylinder 1 begins to rise.

If the driver further depresses the brake pedal after the idle stroke is completed, the regulation rod 18 cannot continue to move due to the regulation received by the regulation plate 19, and both ends of the pedal spring 16 are also regulated by the regulation rod 18. It becomes impossible to move forward in the axial direction, and the pedal spring 16 begins to deform in the axial direction, and as shown in FIG. 12, the pedal spring 16 generates a gradually increasing reaction force transmitted to the brake pedal. At the same time, the reaction plate 17 moves further forward. The control means 5 detects the further forward movement by the pedal stroke sensor 6 and determines the driver's intention of braking by the pedal stroke sensor 6, so that the brake motor 4 rotates forward and the plunger 14 is further forward at a fixed distance. Control to move to. The forward movement of the plunger 14 in this portion causes the piston 2 to move further forward into the cylinder body of the brake master cylinder 1, so that the brake fluid pressure of the brake master cylinder 1 suddenly increases, that is, the pressure suddenly increases. Since the brake master cylinder 1 outputs the brake fluid whose pressure gradually increases toward the brake element of the brake system, the vehicle is braked. After that, the process shifts to the assist stage. At this stage, the pressure-force curve between the output pressure of the brake master cylinder 1 and the assist force of the booster has a high gradient, so that the non-output pressure is rapidly increased. ..

When the braking is completed, the driver loosens the brake pedal, the reaction plate 17 moves backward due to the hydraulic pressure in the brake master cylinder 1 and the pushing force of the first return spring 21, and the control means 5 thereby causes the driver. The drive sleeve 11 returns to the initial position, and the reaction plate 17, the pedal spring 16, and the push rod 15 of the first return spring 21 return to the initial position by driving the reverse rotation of the brake motor 4 while determining the intention of the brake end. It returns to the initial position by the action, and the plunger 14 also returns to the initial position by the action of the second return spring 22.

The normal operation mode of the electric brake booster of the present application, on the other hand, is a substitute for and similar assist to the vacuum booster because the assist force curve provided by the booster is similar to that of the conventional vacuum booster. The function can be provided. On the other hand, the reaction force and stroke of the pedal felt by the driver on the brake pedal is similar to the reaction force and stroke during conventional brake pedal operation.

Subsequently, the all-electric operation mode of the electric brake booster will be described. In the so-called fully electric operation mode, that is, when the driver does not depress the brake pedal, the control means 5 activates the electric brake booster based on the braking signal from the vehicle automatic braking function, or the vehicle automatic braking. The function is to directly control the electric brake booster. In this case, the push rod 15, the pedal spring 16, and the reaction plate 17 are held so as not to move, and the brake motor 4 rotates in the forward direction to drive the forward movement of the plunger 14 by the drive nut 12 and the drive sleeve 11. 2 is pressed forward to realize braking of the vehicle. When the end of braking is confirmed, the brake motor 4 is controlled to rotate in the reverse direction to return the drive sleeve 11 to the initial position, and the plunger 14 also returns to the initial position by the action of the second return spring 22.

Regardless of whether it is in the normal operation mode or the fully electric operation mode, the input of the electric brake booster is derived only from the brake motor 4, and there is no pedal force component. Therefore, these two types of braking modes can be collectively referred to as motor braking operation. Moreover, regardless of whether it is the normal operation mode or the all-electric operation mode, it is possible to provide an assist force ratio and an assist force curve similar to those of the conventional vacuum booster. Further, the pedal stroke given by the driver is only used to determine the driver's intention of braking by the control means 5 in the normal operation mode. In the normal operation mode, the pedal spring 16 is deformed and the gradually increasing reaction force is fed back to the driver's foot via the brake pedal. Therefore, the driver feels the brake with the conventional vacuum booster. It is similar to the conventional brake system including the brake system.

In addition, the electric brake booster further has a full pedal operation mode. The all-pedal operation mode occurs when the brake motor 4 is not operating normally or is disabled, and in this situation, the brake motor 4 is not supplied with power. At this time, since the axial movement lock function of the drive nut 12 is released, the drive nut 12 can be moved in the axial direction. When the driver depresses the brake pedal, the pusher 3 pushes the pedal spring 16 axially forward through the push rod 15 until the reaction plate 17 abuts on the front end wall 14f of the plunger 14, which causes the plunger. By interlocking the forward movement of 14, the piston 2 is pressed forward to brake the vehicle. In this process, the pedal spring 16 pulls the regulation plate 19 through the regulation rod 18, and the regulation plate 19 also moves forward in the axial direction with the drive nut 12 and the drive sleeve 11. After the braking is completed, the related element returns to the initial position by the action of the first return spring 21 and the second return spring 22.

Further, when the electric brake booster is applied to an electric vehicle, it further has an ability to be involved in brake energy recovery. In the brake energy recovery operation, the control means 5 detects the depression of the brake pedal and controls the brake motor 4 so that the plunger 14 is driven to move forward at a predetermined distance.

According to the present application, when the motor braking operation is executed, the braking assist force transmission line of the brake motor of the electric brake booster is separated from the pedal pedal force transmission line. Since the operation of the braking assist force transmitting element does not interlock the pedal pedaling force transmitting element and the brake pedal, it is possible to avoid obstruction of the transmission of the braking assist force and give the driver discomfort from the brake pedal. Can be avoided. Further, when the brake motor is operated, the input of the electric brake booster is derived only from the brake motor and is not combined with the pedal depression force.

When the brake motor is operating normally, the pedal spring is used as an emulator to provide the driver's foot with a feel of feedback braking and to determine the driver's braking intent. Is not converted to part of the output of the brake booster.

The separate electric brake booster of the present application can be completely replaced with the conventional vacuum booster, and can provide brake assist performance similar to that of the vacuum booster. In this respect, it should be pointed out that the vacuum brake booster generates a braking assist force by the degree of vacuum generated in the intake pipe of the engine, so the operation of the vacuum brake booster is relative to the operation of the engine itself. It means that there is a certain effect. Further, after the engine is stopped, the degree of intake vacuum disappears, so that the braking assist force cannot be generated. Since the electric brake booster of the present application does not need to rely on the degree of vacuum generated in the intake pipe of the engine, it is possible to provide the braking assist force function regardless of whether the engine is running or not.

Further, the separate electric brake booster of the present application is particularly suitable for a vehicle having an automatic braking function, that is, the automatic braking function controls the electric brake booster and the vehicle brake system, so that the driver brakes. There is no need to step on the pedal.

It should be pointed out that although the present application is described here with reference to the description of specific embodiments, the scope of the present application is not limited to the disclosed details. .. Various modifications can be made to these details in a situation that does not deviate from the basic principles of the present application.

1 Brake master cylinder 2 Piston 3 Pusher 4 Brake motor 5 Control means 6 Pedal stroke sensor 11 Drive sleeve 12 Drive nut 12a Thread part 12b Front part 12c Rear part 13 Bearing 14 Plunger 14a Main body 14b Flange 14c Small diameter part (inner chamber)
14d radial through hole 14e axial through hole 14f front end wall 15 push rod 16 pedal spring 16a, 16b, 16c leaf spring 17 reaction plate 17a radial extension part 18 regulation rod 18a thin rod part 19 regulation plate 19a guide groove 20 spring Hold 21 1st return spring 22 2nd return spring

Claims (12)

A pedal force transmission mechanism that is driven by a brake pedal and is suitable for moving in the axial direction,
A detection device that is arranged to detect the operation of the pedal force transmission mechanism, and
A brake motor (4) that is suitable for generating a braking assist force by executing a motor braking operation, and a brake motor (4).
The assist force that is arranged to be suitable for transmitting the braking assist force generated by the brake motor to the piston (2) of the brake master cylinder (1) by being driven by the brake motor (4) and moving in the axial direction. An electric brake booster used in a vehicle, including a transmission mechanism.
In the motor braking operation, the assist force transmission mechanism is kinematically separated from the pedal pedal force transmission mechanism, and the brake assist force generated by the brake motor constitutes the input of the electric brake booster. Brake booster. The motor braking operation is
A normal braking operation in which the brake motor (4) is started based on the operation of the pedal pedal force transmission mechanism detected by the detection device and the brake motor (4) is rotated in the forward direction to generate a braking assist force.
The electric motor according to claim 1, further comprising a fully electric operation in which the brake motor (4) is started based on the vehicle automatic braking module braking signal and the brake motor (4) is rotated in the forward direction to generate a braking assist force. Brake booster. The assist force transmission mechanism engages with a drive nut (12) arranged so as to drive rotation by a brake motor, and a drive that engages with the drive nut to convert the rotational motion of the drive nut into a linear motion in the axial direction. Including the sleeve (11)
The assist force transmission mechanism is further arranged in the axial direction between the piston (2) of the brake master cylinder (1) and the drive sleeve (11), and the drive sleeve (11) provides the brake master cylinder (1). The electric brake booster according to claim 1 or 2, wherein the plunger (14) is arranged to be suitable for axially pressing forward toward the cylinder body of the vehicle. The pedal force transmission mechanism is
It is disposed in the drive sleeve (11) and can slide axially in the drive sleeve, the rear part is driven by the brake pedal, and the front part extends into the inner chamber (14b) of the plunger (14). Push rod (15) and
Ability to be connected to the front portion of the push rod (15) and to extend radially from the inner chamber (14d) and elastically deform in the axial direction under the axial pressing action of the push rod (15). The electric brake booster according to claim 3, further comprising a pedal spring (16) comprising. The longitudinal outer end of the pedal spring (16) has a stroke regulated in the forward direction in the axial direction.
Optionally, the regulated stroke is realized by a pedal spring regulation structure, the pedal spring regulation structure includes a regulation rod (18) and a regulation plate (19), and the front end of the regulation rod (18) is the pedal. It is connected to the outer end of the spring (16) in the longitudinal direction, and the rear end of the regulation rod (18) is slidable in the axial direction within a finite distance with respect to the regulation plate (19). The electric brake booster according to claim 4, wherein the regulation plate (19) is fixed by a motor braking operation. The pedal spring (16) includes a combination spring formed by superimposing leaf springs, so that the spring hardness of the pedal spring (16) in the axial direction is gradually increased from the outer end in the longitudinal direction toward the center in the radial direction. The electric brake booster according to claim 4 or 5, which is increasing. The pedal pedal force transmission mechanism further includes a reaction plate (17) attached to the front of the push rod (15).
Any of claims 4 to 6, wherein there is an axial distance between the reaction plate (17) and the front end wall (14f) of the plunger (14) in the non-operated state of the electric brake booster. The electric brake booster according to item 1. A radial extending portion (17a) is provided at one end in the radial direction of the reaction plate (17), and the detection device detects the axial position of the radial extending portion (17a) to obtain a pedal pedal force. The electric brake booster according to claim 7, wherein the operation of the transmission mechanism is determined. The electric motor according to claim 7 or 8, further comprising a first return spring (21) arranged to press the reaction plate (17) along an axial direction away from the brake master cylinder (1). Brake booster. Further, any one of claims 3 to 9, further comprising a second return spring (22) arranged to press the plunger (14) along an axial direction away from the brake master cylinder (1). The electric brake booster described in. When the brake motor (4) is charged, the drive nut (12) is locked in the axial direction and cannot move in the axial direction, but is rotatable and the brake motor (4) is not charged. The electric brake booster according to any one of claims 3 to 9, wherein the axial lock of the drive nut (12) is released. The electric brake booster can execute all pedal braking operations in a state where the brake motor (4) is not charged. Among them, the assist force transmission mechanism follows the pedal pedal force transmission mechanism from the brake pedal. The electric brake booster according to claim 11, wherein the braking force of the brake master cylinder (1) is transmitted to the piston (2) of the brake master cylinder (1).

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