KR20230000074A - Electric Booster for Vehicle - Google Patents

Abstract

Provided in one embodiment of the present invention is an electric booster, which comprises: a motor unit which provides driving power; a housing unit which is coupled to the motor unit; a gear unit which is located inside the housing unit and driven by the motor unit; a screw nut which is located inside the housing unit, is rotated in conjunction with the operation of the motor unit, and is connected to the gear unit; a screw bolt which is screw-coupled to the inner surface of the screw nut and linearly moves in the axial direction in conjunction with the rotation of the screw nut; a boosting block of which one end is inserted into the screw bolt; a reaction disk which is in contact with the other end of the boosting block; a rod unit which penetrates the screw bolt and the boosting block; and a stroke sensor which has a hall sensor located outside the housing unit and a magnet fastening member connected to the rod unit in a vertical direction and linearly to move in the axial direction according to a linear movement of the rod unit. Therefore, the electric booster reduces errors caused by accumulated component tolerances, and allows the driver to brake with the desired precision.

Description

Electric Booster for Vehicle {Electric Booster for Vehicle}

The present disclosure relates to an electric booster for a vehicle. More specifically, it relates to an electric booster that detects a stroke travel distance of a brake pedal of a vehicle and generates brake hydraulic pressure required for braking.

The content described in this section simply provides background information for the present disclosure and does not constitute prior art.

In general, a braking system of a vehicle generates frictional force by moving a brake pad to decelerate a vehicle in motion or maintain a parked state. However, since the driver's power is limited, brake performance is increased through boosting power by a booster. In the past, a booster using a vacuum has been used, but recently, an electric booster using a motor has been used. The electric booster includes a motor for forming braking pressure, a screw that converts the rotational torque of the motor into linear kinetic energy, a rod that transmits the driver's foot force and the driving force of the motor to a piston, and and a stroke sensor for determining the displacement of the pedal. At this time, a portion of the driver's pedal stroke effort presses the piston via a rod penetrating a bolt, and the piston is provided with a disk for uniformly providing the pedal stroke effort and the driving force of the motor. In the case of an electric booster, when a driver steps on a brake pedal in a normal vehicle driving state, not only the pedal effort but also the driving force of the motor acts on the reaction disc as boosting force.

Conventionally, a stroke sensor for detecting a driver's pedal stroke is installed on a brake pedal, the stroke detected by the stroke sensor is converted into an electrical signal, and the signal is transmitted to an electronic control unit (ECU). The electronic control unit determines a driver's braking demand based on the received signal, and determines the rotation amount of the motor according to the driver's braking request. Hydraulic pressure is generated in a master cylinder according to the amount of rotation of the motor, and the generated hydraulic pressure is supplied to a wheel cylinder to generate braking force.

In the case of the conventional brake system, the stroke sensor that detects the displacement of the pedal is installed on the pedal instead of inside the brake, and it is difficult to precisely grasp the displacement of the pedal due to errors caused by accumulation of parts from the stroke sensor to the electronic control unit. there is.

In addition, since the stroke sensor is installed on the pedal instead of inside the brake, a layout connecting the stroke sensor to the electronic control unit is complicated and takes up a lot of space.

The electric booster according to an embodiment can reduce an error due to an accumulation tolerance of parts from the stroke sensor to the electronic control unit by locating the stroke sensor inside the electric brake.

In addition, the electric booster according to an embodiment can improve the layout from the stroke sensor to the electronic control unit by locating the stroke sensor inside the electric brake.

The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

According to one embodiment of the present disclosure for achieving this object, the motor unit (motor unit) for providing a driving force; a housing unit coupled to the motor unit; a gear unit located inside the housing unit and driven by the motor unit; A screw nut located inside the housing unit and connected to the gear unit to be rotated in conjunction with the operation of the motor unit; A screw bolt that is screwed with the inner surface of the screw nut and moves linearly in an axial direction in conjunction with the rotation of the screw nut; A boosting block having one end inserted into the screw bolt; A reaction disk in contact with the other end of the boosting block; A rod unit penetrating the screw bolt and boosting block; and a hall sensor positioned outside the housing unit and a stroke sensor including a magnet fastening member that is vertically connected to the rod unit and linearly moves in an axial direction according to the linear motion of the rod unit. Provide an electric booster.

According to one embodiment, the electric booster simplifies the control process from the stroke sensor to the electronic control unit, thereby reducing errors due to component accumulation tolerances, thereby enabling the driver to brake precisely as desired.

According to one embodiment, the electric booster has the effect of saving space by improving the layout from the stroke sensor to the electronic control unit.

1 is a cross-sectional view of an electric booster according to an embodiment of the present disclosure.
2 is an exploded view of a magnet fastening member of an electric booster according to an embodiment of the present disclosure.
3 is a view showing a magnet fastening member according to an embodiment of the present disclosure.

Hereinafter, some embodiments of the present disclosure are described in detail using exemplary drawings. In adding reference numerals to components of each drawing, it should be noted that the same components have the same numerals as much as possible even if they are displayed on different drawings. In addition, in describing the present disclosure, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present disclosure, the detailed description will be omitted.

In describing the components of the embodiment according to the present disclosure, symbols such as first, second, i), ii), a), and b) may be used. These codes are only for distinguishing the component from other components, and the nature or sequence or order of the corresponding component is not limited by the codes. In the specification, when a part is said to 'include' or 'include' a certain component, it means that it may further include other components, not excluding other components unless explicitly stated otherwise. .

1 is a cross-sectional view of an electric booster according to an embodiment of the present disclosure.

Referring to FIG. 1 , an electric booster 100 for a vehicle according to an embodiment of the present disclosure includes a motor unit 180, a housing unit 190, and a gear unit 170. , screw nut (161), screw bolt (screw bolt, 162), reaction disk (reaction disk, 121), boosting block (boosting block, 131), rod unit (not shown) and stroke sensor ( stroke sensor, not shown) may include all or part.

As shown in Figure 1, the electric booster 100 has a structure connected to the master cylinder (master cylinder, 30) to the front side of the housing portion (190). A piston (31) linearly moving in the axial direction inside the master cylinder (30) is connected to the electric booster (100). Hereinafter, the axial direction means the longitudinal direction of the piston 31, the first rod 111, the second rod 112, and the like. The electric booster 100 is connected to an operating rod 10 to the rear side. The electric booster 100 is disposed in the engine room and fixed to the dash panel in a state in which the operating rod 10 protrudes from a dash panel, which is a partition between the engine room and the inside of the vehicle, and is directed toward the vehicle interior . When a driver steps on a pedal, the operating rod 10 presses the rod portion of the electric booster 100 . The rod unit sequentially presses the piston 31 inside the master cylinder 30 . As the piston 31 inside the master cylinder 30 moves linearly in the axial direction, brake fluid pressure is generated in the hydraulic chamber inside the master cylinder 30 . Since the internal hydraulic chamber of the master cylinder 30 communicates with the wheel cylinder of each wheel, the hydraulic pressure of the brake fluid generated by the master cylinder 30 is transmitted to the wheel cylinder of each wheel, generate braking force for each, and as a result brake the vehicle.

The reaction disk 121 is made of an elastic material that can be elastically deformed, such as rubber, and has a disc shape and is located between the piston and the boosting block 131. The disk holder 122 is a device for holding the reaction disk 121 in a set position and is installed inside the housing 190 . The reaction disk 121 is accommodated inside the disk holder 122 and is disposed at a set position inside the housing 190 . One side of the disk holder 122 includes a groove having a larger diameter than the reaction disk 121 so as to accommodate the reaction disk 121 therein. The reaction disk 121 is inserted and fixed into the disk holder 122 groove. The other side of the disk holder 122 protrudes and extends so as to press the piston 31 . The protruding portion of the disc holder 122 has a groove formed therein so that the push rod 20 can be inserted. One end of the push rod 20 is inserted into the groove of the disc holder 122 and coupled, and the other end contacts the piston 31 of the master cylinder 30.

Based on the reaction disk 121 and the disk holder 122, a master cylinder 30 and a piston 31 are disposed on one side (left side in FIG. 1), and a screw nut 161 on the other side (right side in FIG. 1) , the screw bolt 162, the rod part and the boosting block 131 are disposed. The movement displacement of the screw bolt 162 and the rod part is through the boosting block 131, through the reaction disk 121 and the disk holder 122, and up to the piston 31 of the master cylinder 30.

When the reaction disk 121 has a disk shape, the outer portion in the radial direction of the reaction disk 121 has a ring shape, and the central portion in the radial direction of the reaction disk 121 has a circular shape disposed inside the outer portion in the radial direction. . The radially outer portion and the radially central portion of the reaction disk 121 are disposed to face the boosting block 131 and the rod portion, respectively.

The screw nut 161 rotates in conjunction with the operation of the motor unit 180 . The rotational force generated by the motor unit 180 is transmitted to the screw nut 161 via the gear unit 170 connected to the drive shaft of the motor. The gear unit 170 may include a plurality of gears, a connecting member, a belt member, and the like.

The screw bolt 162 is screwed into the inner diameter of the screw nut 161 and performs linear motion in the axial direction in conjunction with the rotation of the screw nut 161 . The screw bolt 162 presses the boosting block 131 or makes a linear motion in a direction spaced apart from the boosting block 131. The rotational motion of the screw nut 161 is converted into linear motion of the screw bolt 162, and finally acts on the piston 31 through the boosting block 131, reaction disc 121 and disc holder 122. . Hydraulic pressure for braking the vehicle is formed inside the master cylinder 30 by the movement of the piston 31 . The electric booster 100 according to an embodiment of the present disclosure may include a separate pressing member 132 between the boosting block 131 and the screw bolt 162. The pressing member 132 helps the boosting block 131 finally press the reaction disk 121 by transferring the force caused by the linear motion in the axial direction by the screw bolt 162 to the boosting block 131. .

The boosting block 131 is a device unit for uniformly distributing and transmitting the force caused by the axial linear motion of the screw bolt 162 to the outer portion of the reaction disk 121 in the radial direction. The reaction disk 121 has a larger diameter than the screw bolt 162. The boosting block 131 has a cross-sectional shape corresponding to the radially outer portion of the reaction disk 121, and is disposed between the reaction disk 121 and the screw bolt 162. The boosting block 131 is coupled to the rod portion, but is coupled to be slidable without being fixed to the rod portion. One side of the boosting block 131 is in contact with the reaction disk 121, and the other side of the boosting block 131 is in contact with the pressing member 132. When the screw bolts 162 linearly move in the direction of the reaction disk 121, the boosting block 131 is pushed by the screw bolts 162 to press the outer portion of the reaction disk 121 in the radial direction.

The rod unit of the electric booster 100 according to an embodiment of the present disclosure may include all or part of a first rod 111 and a second rod 112. The rod portion passes through the screw bolt 162 and the boosting block 131 and comes into contact with the central portion of the reaction disk 121 in the radial direction. The first rod 111 has a substantially cylindrical shape, one end of which is in contact with the central portion of the reaction disk 121 in the radial direction, and the other end of which is in contact with the central portion in the radial direction of the reaction disk 121 and a second diameter smaller than the first diameter. The second rod has a cylindrical shape with grooves at both ends, and the second diameter portion of the first rod is inserted and coupled to one end, and the operating rod 10 is inserted to the other end. The second rod 112 is connected to the brake pedal through the operating rod 10. The operating rod 10, the second rod 112, and the first rod 111 are moved simultaneously or sequentially in association with the movement of the brake pedal generated when the driver steps on the brake pedal. As the driver steps on the brake pedal, the rod part moves linearly in the direction of the reaction disk 121, and the first rod 111 presses the central portion of the reaction disk 121 in the radial direction.

The rod portion and the screw bolt 162 can move linearly in the axial direction together or separately. For example, in realizing braking of a vehicle, when only the motor is driven without the foot force acting on the brake pedal, the pressing force does not act on the central portion in the radial direction of the reaction disk 121, and the movement of the screw bolt 162 The boosting block 131 applies a pressing force only to the outer portion of the reaction disk 121 in the radial direction. Conversely, when the rod unit advances, the rod unit presses the central portion of the reaction disk 121 in the radial direction. In realizing vehicle braking, when the pedal force is applied only to the brake pedal and the motor is not driven due to a failure of the motor, the pressing force does not act on the outer portion in the radial direction of the reaction disk 121, and the pressing force is applied only to the central portion in the radial direction. It works.

The electric booster 100 for a vehicle according to an embodiment of the present disclosure may include a stroke sensor to operate the motor unit 180 . The stroke sensor may include a magnet fastening member 140, a hall sensor 151, and a sensor housing 152.

The sensor housing 152 serves to protect the Hall sensor 151 by being coupled to the outer surface of the housing part 190 . The hall sensor 151 is located in a space between the housing part 190 and the sensor housing 152 and is fixed through a separate connecting member or the like. The magnet 141 is connected to the magnet fastening member 140, such as the magnet holder 142, is positioned facing the hall sensor 151, and is interlocked with the movement of the brake pedal generated as the driver steps on the brake pedal to form a housing. It moves along the guidelines 191 inside the unit. A separate control unit (not shown) may determine the moving distance of the driver's brake pedal stroke by using signal transmission between the magnet 141 and the hall sensor 151. Based on the movement distance of the brake pedal stroke determined by the control unit, the motor unit 180 is operated. The operation of the motor unit 180 causes the gear unit 170, the screw nut 161, the screw bolt 162, and the boosting block 131 to move in conjunction. As a result, when the driver presses the brake pedal, the rod part presses the central portion of the reaction disk 121 in the radial direction, and at the same time, the boosting block 131 presses the outer portion of the reaction disk 121 in the radial direction. The structure of the magnet fastening member 140 will be described in detail below.

The electric booster 100 for a vehicle according to an embodiment of the present disclosure may include an elastic member (not shown). The elastic member surrounds the reaction disk 121 and the disk holder 122 and is located inside the housing 190 . The elastic member pressurizes the reaction disk 121 when the driver steps on the brake pedal and the boosting block 131, and then restores the reaction disk 121 to an initial state when the driver does not step on the brake pedal anymore. play a role

2 is an exploded view of a magnet fastening member of an electric booster according to an embodiment of the present disclosure.

3 is a view showing a magnet fastening member according to an embodiment of the present disclosure.

2 and 3, the magnet fastening member 140 of the electric booster 100 according to an embodiment of the present disclosure includes a magnet (magnet, 141), a magnet holder (magnet holder, 142) and a key (key, 143) may include all or part of.

The key 143 is coupled with the rod part and moves along with the axial linear movement of the rod part. In detail, the load unit of the electric booster 100 according to an embodiment of the present disclosure includes a first rod 111 and a second rod 112. The first rod 111 has a cylindrical shape and includes a first diameter portion contacting the central portion of the reaction disk 121 in the radial direction and a second diameter portion smaller than the first diameter. The second diameter portion is inserted into the second rod 112, and the first rod 111 and the second rod 112 are coupled by bolting. The key 143 is coupled to the second diameter portion of the first rod 111 and positioned between the first rod 111 and the second rod 112. The key 143 may include a fixing part 143a having an annular end. The fixing part 143a may cover all or part of the outer circumferential surface of the first rod 111 . The fixing part 143a surrounds at least a portion of the outer circumferential surface of the first rod 111, and the fixing part 143a and the first rod 111 are coupled so that the key 143 and the first rod 111 are perpendicular to each other. The inner circumferential diameter of the fixing part 143a and the outer circumferential diameter of the first rod 111 may match so that the fixing part 143a and the first rod 111 can be bolted together. The key 143 may have a rod-shaped body and include an insertion portion 143b at the other end of the fixing portion 143a. The insertion portion 143b may be press-fitted into the magnet holder 142 and coupled thereto. The magnet holder 142 serves to surround and protect the magnet 141 . The magnet 141 and the magnet holder 142 are coupled so that the magnet 141 does not leave the magnet holder 142 and is fixed. The magnet fastening member 140 of the electric booster 100 for a vehicle according to an embodiment of the present disclosure is not limited to a certain shape. For example, the key 143 and the magnet holder 142 may have an integrated shape. In addition, all or part of the body of the key 143, the fixing part 143a, and the insertion part 143b do not necessarily have to have an integrated shape, and all or part of them may have an assembleable shape.

In one embodiment of the present disclosure, the magnet fastening member 140 of the electric booster 100 for another vehicle may move in communication with the rod unit. When the rod part moves in the direction of the reaction disk 121 as a result of the driver pressing the brake pedal, the key 143 bolted vertically to the first rod 111 of the rod part also moves in the direction of the reaction disk 121. . At this time, while the first rod 111 is inserted into the boosting block 131, the boosting block 131 may have a key 143-shaped groove so that a part of the key 143 can also be inserted. As the key 143 coupled to the first rod 111 moves in communication with the first rod 111, the magnet holder 142 coupled to the insertion portion 143b of the key 143 also communicates and moves. . As the magnet holder 142 moves, the magnet 141 wrapped around the magnet holder 142 may also move together.

The housing part 190 of the electric booster 100 according to an embodiment of the present disclosure may include a guideline 191 of a certain space so that the magnet holder 142 and the magnet 141 can move. The guideline 191 may be located inside the housing part 190 and located in a space facing the hall sensor 151 . The guideline 191 serves to prevent the magnet holder 142 from encountering the hall sensor 151 and leaving a certain position. The magnet 141 wrapped in the magnet holder 142 performs a linear motion along the guide line 191 in conjunction with the linear motion of the rod unit. The hall sensor 151 determines the stroke of the brake pedal according to the degree of linear motion of the magnet 141, and the control unit operates the motor unit 180 based on the stroke information of the brake pedal so that the electric booster 100 moves the piston (31) to transmit power.

The above description is merely an example of the technical idea of the present embodiment, and various modifications and variations can be made to those skilled in the art without departing from the essential characteristics of the present embodiment. Therefore, the present embodiments are not intended to limit the technical idea of the present embodiment, but to explain, and the scope of the technical idea of the present embodiment is not limited by these embodiments. The scope of protection of this embodiment should be construed according to the claims below, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of rights of this embodiment.

10: operating rod 20: push rod
30: master cylinder 31: piston
100: electric booster
111: first rod 111a: first diameter
111b: second diameter 112: second rod
121: reaction disk 122: disk holder
131: boosting block 132: pressing member
140: magnet fastening member 141: magnet
142: magnet holder 143: key
143a: fixing part 143b: insertion part
151: hall sensor 152: sensor housing
161: screw nut 162: screw bolt
170: gear unit 180: motor unit
190: housing part 191: guideline

Claims (13)

a motor unit that provides driving force;
a housing unit coupled to the motor unit;
a gear unit located inside the housing unit and driven by the motor unit;
a screw nut located inside the housing unit and connected to the gear unit to be rotated in conjunction with the operation of the motor unit;
a screw bolt that is screwed into the inner surface of the screw nut and moves linearly in an axial direction in conjunction with the rotation of the screw nut;
a boosting block having one end inserted into the screw bolt;
a reaction disk contacting the other end of the boosting block;
a rod unit penetrating the screw bolt and the boosting block; and
A stroke sensor having a hall sensor located outside the housing part and a magnet fastening member vertically connected to the rod part and linearly moving in an axial direction according to the linear motion of the rod part
An electric booster comprising a. According to claim 1,
The magnet fastening member,
The electric booster further comprises a key having a ring-shaped fixing part having one end surrounding at least a part of the outer surface of the rod part and an insertion part having the other end inserted into the magnet holder. According to claim 2,
The magnet holder and the key,
An electric booster having an integral shape with the key inserted into the magnet holder. According to claim 2,
The loading part,
a first rod having a cylindrical shape and having a first diameter portion at one end in contact with the reaction disk and a second diameter portion smaller than the first diameter portion at the other end; and
An electric booster comprising a second rod including a groove for inserting the second diameter portion. According to claim 4,
The key includes a ring-shaped fixing portion having one end surrounding at least a portion of an outer surface of the second diameter portion,
The electric booster is coupled to the second diameter portion and positioned between the first rod and the second rod. According to claim 2,
The boosting block is an electric booster including a cylindrical hollow part with one side open for sliding the key. According to claim 1,
the housing part,
The electric booster including a guide line for accommodating the magnet fastening member so that the magnet fastening member moves in the axial direction. According to claim 1,
The hall sensor is plural, and is positioned on the outer surface of the housing part at regular intervals, but is fixed using a connecting member,
An electric booster including a sensor housing coupled to the outside of the housing unit and surrounding the sensor. According to claim 1,
The magnet fastening member is located inside the housing and faces the hall sensor to transmit a signal to the hall sensor. According to claim 1,
The electric booster further comprises a disk holder having one end accommodating the reaction disk and the other end protruding and extending in the moving direction to press the piston. According to claim 10,
Further including a pushing rod,
The other end of the disk holder includes a groove for inserting the pushing rod. According to claim 1,
The electric booster further comprises an elastic member that contacts the boosting block and restores the reaction disk to an initial position. According to claim 1,
The electric booster further comprises a pressing member positioned between the screw bolt and the boosting block to press the boosting block.

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