JP5698108B2 - Motor cylinder device - Google Patents

Description

  The present invention relates to a motor cylinder device in an electric brake actuator incorporated in, for example, a vehicle brake system.

  2. Description of the Related Art Conventionally, a booster using a negative pressure booster or a hydraulic booster is known as an automobile brake mechanism. In recent years, an electric booster using an electric motor as a boost source has been disclosed as this type of booster (see, for example, Patent Document 1).

  The electric booster disclosed in Patent Document 1 includes a main piston that moves forward and backward by operating a brake pedal, a cylindrical booster piston that is externally fitted so as to be relatively displaceable with the main piston, and a forward and backward movement of the booster piston. It is configured as a single unit with an electric motor to be operated.

In this case, the main piston and the booster piston are used as the pistons of the master cylinder, and the front end portions of the main piston and the booster piston face the pressure chamber of the master cylinder. Therefore, the brake fluid pressure is generated in the master cylinder by the input thrust applied from the brake pedal to the main piston and the booster thrust applied from the electric motor to the booster piston.
The electric motor used in this device is composed of a stator fixed to a housing body and a hollow rotor, and a ball screw mechanism is disposed on the rotor via a key in a state of passing through the center of the rotor. It is designed exclusively for this electric booster.

  When such an electric motor designed exclusively is used, not only the cost increases, but also the versatility as an electric motor is impaired. Therefore, the electric motor includes a motor main body (motor casing) and a bracket (base). It is advocated to adopt a general one that is configured and has excellent versatility.

JP 2010-23594 A

  By the way, when mounting a general electric motor with such versatility to an electric booster (brake system), the driving force of the electric motor is transmitted in the part where the electric motor is stored for the purpose of reducing the weight. It is conceivable to make the bracket (base part) in contact with the driving force transmission part to be made of resin. However, if the base is made of resin, a minute gap due to the difference in material occurs between the base and the metal driving force transmission portion. Then, this gap may cause play, causing vibration generated outside the brake system to be transmitted and the electric motor to vibrate, or when the electric motor is driven, a meshing sound between the transmission gears may be generated. This could cause motor vibration and noise.

  The present invention has been made in view of the above points, and it is an object of the present invention to improve the mounting rigidity generated between the electric motor unit and the driving force transmission unit, and to prevent vibration and noise of the electric motor.

In order to achieve the above object, the present invention provides a motor cylinder device in an electric brake actuator that generates a brake fluid pressure based on an electric signal corresponding to a brake operation, and a motor casing in which an electric motor is housed. And an electric motor unit having a base, and a drive force transmission unit that is made of metal and that transmits the drive of the electric motor, and the base is made of resin and the motor There is a backlash preventing means that is coupled to a casing and is in contact with the driving force transmitting portion, formed on a surface of the base facing the driving force transmitting portion, and a protrusion formed integrally with the base. It is characterized by that.

  According to the present invention, it is possible to improve the attachment rigidity generated between the electric motor unit and the driving force transmission unit. Thereby, it is possible to prevent backlash due to the difference in material between the base portion of the electric motor unit and the driving force transmission unit, and it is possible to suppress vibration, noise, and the like of the electric motor.

In addition, according to the present invention, the projection integrated with the base can facilitate the assembly of the electric motor unit and the driving force transmission unit.

  According to the present invention, it is possible to improve the attachment rigidity generated between the electric motor unit and the driving force transmission unit, and to prevent vibration and noise of the electric motor.

It is a perspective view of a motor cylinder device. It is a disassembled perspective view of the motor cylinder apparatus which concerns on 1st Embodiment. It is a side view of the motor cylinder device concerning a 1st embodiment. It is a disassembled perspective view of the motor cylinder apparatus which concerns on 2nd Embodiment. It is an end view of the base which concerns on 2nd Embodiment.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.

[First Embodiment]
First, a first embodiment of the present invention will be described with reference to FIGS.

  1 is a perspective view of the motor cylinder device, FIG. 2 is an exploded perspective view of the motor cylinder device according to the first embodiment, and FIG. 3 is a side view of the motor cylinder device according to the first embodiment. In FIG. 2, only the electric motor 72 is a perspective view from the base 72b.

The motor cylinder device 16 in the vehicle brake system has the following configuration. Here, the motor cylinder device 16 operates as an electric brake actuator that controls the brake fluid pressure in the vehicle brake system.
As shown in FIG. 1, the motor cylinder device 16 functioning as an electric brake actuator includes an actuator mechanism 74 having an electric motor unit 72 and a driving force transmission unit 73, and a cylinder mechanism operated by the actuator mechanism 74. 76. In this case, as shown in FIG. 2, the electric motor unit 72, the driving force transmission unit 73, and the cylinder mechanism 76 are provided to be separable.

  The actuator mechanism 74 includes a driving force transmission unit 73 that transmits a rotational driving force of a gear 72d attached to the output shaft of the electric motor unit 72, and a linear motion ( A ball screw structure (not shown) that converts the axial force into a slave piston (not shown) side of the cylinder mechanism 76.

  The electric motor unit 72 stores, for example, an electric motor such as a servo motor that is driven and controlled based on a control signal (electric signal) from a control unit (not shown), and is disposed above the cylinder mechanism 76. Yes. By arranging and configuring in this way, it is possible to suitably avoid oil components such as grease in the driving force transmission unit 73 from entering the electric motor unit 72 due to gravity.

The electric motor portion 72 is formed in a bottomed cylindrical shape, and includes a motor casing 72a that houses the electric motor, and a base portion 72b that is integrally coupled to the motor casing 72a and to which a harness (not shown) is connected. Is done. The base portion 72b is formed with a plurality of insertion holes 77b through which the screw members 77a are inserted, and the electric motor portion 72 is fastened to the first body 75a of the actuator housing 75 described later via the screw members 77a. Reference numeral 72c denotes a contact surface that contacts the contact surface 75c of the first body 75a.
The base 72b is made of resin, and the motor casing 72a is made of metal.

A cylindrical collar member 77d made of a metal material is embedded in the insertion hole 77b in the base 72b by an insert molding method. One end side of the collar member 77d slightly protrudes from the contact surface 72c, and when the electric motor portion 72 is fastened to the actuator housing 75, one end side of the collar member 77d contacts the contact surface 75c, and the color member 77d. Both end surfaces in the axial direction are sandwiched between the flange portion of the motor casing 72a and the contact surface 75c of the actuator housing 75 so that the tightening force of the screw member 77a is received by the collar member 77d.
Thus, the tightening stress of the screw member 77a is not directly applied to the resin base 72b.

  The driving force transmission unit 73 includes an actuator housing 75, and mechanical elements for driving force transmission, such as a gear mechanism (not shown) and a ball screw structure (not shown), are provided in the space in the actuator housing 75. Stored. The actuator housing 75 is divided into a first body 75a disposed on the cylinder mechanism 76 side and a second body 75b that closes the opening end of the first body 75a opposite to the cylinder mechanism 76. The first body 75a and the second body 75b constituting the actuator housing 75 are integrally coupled via four bolts 83a (FIG. 3) and are separable from each other. In addition, the 1st body 75a and the 2nd body 75b which comprise the driving force transmission part 73 are metal.

  As shown in FIGS. 1 and 3, a gap 200 is formed between the base portion 72 b of the electric motor portion 72 and the first body 75 a of the actuator housing 75 due to the protrusion 201 described later.

  As shown in FIG. 2, on the upper side of the first body 75a, a pair of screw holes 77c for attaching the electric motor portion 72 to the driving force transmission portion 73 is provided, and the pair of screw members 77a are connected to the screw holes 77c. The electric motor part 72 is fixed by fastening to. Further, a flange portion 79 having a substantially rhombus shape is provided at an end portion of the first body 75a on the cylinder mechanism 76 side, and a substantially circular opening 79a and the cylinder mechanism 76 are attached to the flange portion 79. A pair of screw holes 81c is provided. In this case, a pair of screw members 81a penetrating through an insertion hole 81b of a flange portion 82a provided at the other end portion of a cylinder body 82 described later is screwed into the screw hole 81c, thereby driving the cylinder mechanism 76 and driving. The force transmission unit 73 is integrally coupled. In FIG. 1 to FIG. 5, the description of the gear meshing with the gear 72 d in the driving force transmission unit 73 is omitted.

  As shown in FIG. 2, a circular protrusion 201 is provided integrally with the base 72b as a backlash preventing means on the surface of the base 72b facing the first body 75a. The protrusion 201 may be hard or soft. If it is soft, the projection 201 is crushed when the electric motor unit 72 and the driving force transmission unit 73 are assembled, and the two are coupled to each other, so that the prevention of backlash can be improved.

  In the first embodiment, the protrusion 201 has a circular shape, but is not limited thereto, and may have a rectangular shape or the like. In the example shown in FIG. 2, a total of twelve protrusions 201 are arranged, four on one side and eight on the other side. However, the position and number of the protrusions 201 are not limited to this. In order to avoid the insertion hole 77b, the contact hole 72c may be disposed around the entire circumference.

According to the first embodiment, by providing the protrusion 201, the fastening by the screw member 77a can be strengthened. That is, the attachment rigidity generated between the electric motor unit 72 and the driving force transmission unit 73 can be improved. Along with this, play can be prevented and vibration, noise, etc. of the electric motor can be suppressed.
Moreover, the assembly of the electric motor part 72 and the driving force transmission part 73 can be made easy by setting it as the protrusion 201 integrated with the base part 72b.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS.
Note that in the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. Moreover, in FIG. 4, only the electric motor part 72 is a perspective view from the base 72b.
FIG. 4 is an exploded perspective view of the motor cylinder device according to the second embodiment, and FIG. 5 is an end view of the base portion according to the second embodiment.
As shown in FIG. 4, in the motor cylinder device 16A in the second embodiment, an annular and plate-like shim 202 is provided between the base 72b and the first body 75a as a backlash preventing means instead of the protrusion 201. It is sandwiched. The material of the shim 202 may be resin, rubber, metal or the like. As shown in FIG. 5, the shim 202 is configured to have a size that avoids the insertion hole 77b during assembly. The shim 202 is sandwiched between the contact surfaces 72c and 75c.

In the second embodiment, the shape of the shim 202 is an annular shape. However, the shape is not limited to this, and the shim 202 may be divided into a plurality of parts.
In this case, if a space where the annular shim 202 can be attached can be secured on the base 72b, the shim 202 is annular, and it is difficult to secure the space due to the positional relationship of the insertion hole 77b and the like. It is desirable to divide the shim 202 into a plurality of parts and arrange each of the divided shims 202 into an empty space. Further, when divided into a plurality of parts, it is desirable that each part is arranged at a position avoiding the insertion hole 77b. The shim 202 is preferably a thin plate, but is not limited thereto, and may have a thickness.

By providing a replaceable shim 202 as such a backlash prevention means, it is possible to prevent vibration and noise of the electric motor due to backlash prevention and to replace the shim due to deterioration.
Further, by making the shim 202 into an annular shape, the frictional force can be improved, and the shim can be stably fixed.
Further, by dividing the shim 202, the shim can be installed in a vacant space even when there is little space for installing the shim 202 in the base 72 b and the power transmission unit 73.

  Further, when the motor cylinder device 16 is assembled, the actuator housing 75 is fixed so that the second body 75b is located below and the first body 75a is located above, and the shim 202 is placed on the first body 75a. Thereafter, the electric motor unit 72 may be assembled. Alternatively, the actuator housing 75 may be assembled after the electric motor 72 is fixed downward and the shim 202 is placed on the base 72b. By doing so, the shim 202 can be easily assembled.

  The motor cylinder device 16 is provided so as to be mountable on various vehicles including, for example, an automobile driven only by an engine (internal combustion engine), a hybrid automobile, an electric automobile, and a fuel cell automobile.

16 Motor cylinder device (electric brake actuator)
72 Electric motor portion 72a Motor casing 72b Base portion 72c Abutting surface 72d Gear 75 Actuator housing 75a First body 75b Second body 76 Cylinder mechanism (cylinder)
77b Insertion hole 77c Screw hole 77d Collar member 78 Gear mechanism 80 Ball screw structure (conversion mechanism)
201 Protrusion (backlash prevention means)
202 Shim (Backlash prevention means)

Claims (1)

A motor cylinder device in an electric brake actuator that generates a brake fluid pressure based on an electric signal corresponding to a brake operation,
An electric motor unit having a motor casing in which an electric motor is stored, and a base;
A drive force transmission unit that is made of metal and that transmits the drive of the electric motor;
Have
The base is made of resin, is coupled to the motor casing, and is in contact with the driving force transmission unit,
A motor cylinder device comprising backlash preventing means formed on a surface of the base portion facing the driving force transmitting portion and formed integrally with the base portion .

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