JP5846874B2 - Motor cylinder device for electric brake - Google Patents

Description

  The present invention relates to an electric brake device mounted on an electric vehicle or a hybrid vehicle, and more particularly to a technique for improving the flexural strength and weight reduction of a gear housing constituting a motor cylinder.

  In an electric vehicle or a hybrid vehicle that is driven by an electric motor, a master back that uses an intake negative pressure of an internal combustion engine as a drive source cannot be adopted as a brake booster. Separately, a brake-by-wire type electric brake device that generates a brake pressure by a motor cylinder using an electric actuator is generally employed. In the motor cylinder, the rotational force of the electric motor is transmitted to the ball screw mechanism that performs radial-thrust conversion through the reduction gear mechanism, and the piston in the cylinder body is pressed by the screw shaft of the ball screw mechanism to generate brake fluid pressure. (For example, refer to Patent Document 1).

JP 2008-184057 A

  The electric brake device of Patent Document 1 employs an expensive bevel gear for the reduction gear mechanism, and thus has a drawback that the product cost is high, and high machining accuracy and assembly accuracy are required. Therefore, the present inventors tried to construct a reduction gear mechanism by a combination (hereinafter referred to as a gear train) of a spur gear (hereinafter referred to simply as a gear) that is easy and inexpensive to manufacture. It has been found that problems arise due to the output shaft (motor shaft) and the central axis of the ball screw mechanism being parallel. That is, the gear train constituting the reduction gear mechanism is housed in a gear housing divided into two (that is, composed of a pair of gear housing halves) connected to the end of the cylinder body. In response to the reaction force from the ball screw mechanism, a large repulsive force may act on the cantilevered drive gear fixed to the shaft of the electric motor. As a result, the gear housing half on the side where the electric motor is attached is bent and deformed (by opening the gear housing), causing the electric motor fixed to the gear housing half to fall in the axial direction. Further, the meshing between the drive gear and the driven gear (or idler gear) becomes shallow, and there is a possibility that the durability of the reduction gear mechanism may be reduced due to wear of both gears.

  The present invention has been made in view of such a background, and an object of the present invention is to provide a motor cylinder device for an electric brake that realizes improvement in flexural strength and weight reduction of a gear housing.

In the first aspect of the present invention, the electric motor (12) that is driven and controlled in response to the depression operation of the brake pedal (11) by the driver, and the drive gear (41) fixed to the shaft (12a) of the electric motor. ) Torque to the driven gear (43), a ball screw mechanism (29) for converting the driven gear torque into the thrust of the screw shaft (19), and the thrust of the screw shaft. An electric brake motor cylinder device (13) including a brake cylinder for generating a brake fluid pressure, the cylinder body ( 31 ) forming an outline of the brake cylinder, and an end of the cylinder body on the ball screw mechanism side A first gear housing half (35) connected to the first portion and a plurality of gear housing fastening portions (71 to 75). A second gear housing half (36) that is fastened to a side of the ring half that is separated from the cylinder body, and that forms a gear housing (32) that houses at least the reduction gear mechanism together with the first gear housing half, The electric motor is fastened to a plurality of motor fastening portions (63 to 66) provided in one of the first gear housing half and the second gear housing half, and at least one of the gear housing fastening portions is: A first gear housing fastening portion (71) disposed on the opposite side of the driven gear across the drive gear.

  In the second aspect, a motor holding recess (61) into which an end of the electric motor is fitted is provided on a side of the first gear housing half and the second gear housing half to which the electric motor is fastened. The head portion of the bolt (78) formed and used for fastening at the first gear housing fastening portion faces the end face of the electric motor in the motor holding recess.

In the third aspect, wherein the second gear housing fastening portion from the outer circumference of the plurality of projecting outwardly of the gear housing fastening section the gear housing, definitive in the second gear housing fastening portion and the front firewood Yahaujin grayed Connection ribs (85, 86) that connect the outer periphery of the driven gear storage part (58) were provided.

In the fourth aspect, the electric motor is fastened to a plurality of motor fastening portions (63 to 66) provided in the first gear housing half, and the motor fastening portion sandwiches the drive gear. A first motor fastening portion (63, 64) protruding from the outer periphery of the first gear housing half on the opposite side of the driven gear, and the first gear housing half on the same side as the driven gear with respect to the first motor fastening portion . And a second motor fastening portion (65, 66) protruding from the outer periphery, and the first gear housing half has connecting ribs (81, 82) connecting the first motor fastening portion and the second motor fastening portion. Provided.

  In the fifth aspect, the first gear housing half is provided with connecting ribs (83, 84) that connect the second motor fastening portion and the outer periphery of the driven gear storage portion in the first gear housing half. .

  In the sixth aspect, the second gear housing half has a plurality of lightening recesses (91 to 99) on a surface away from the cylinder body.

  According to the first invention, even if a large repulsive force acts on the drive gear due to the reaction force input from the reduction gear mechanism to the ball screw mechanism, the first gear housing is disposed on the opposite side of the driven gear across the drive gear. By being fastened at the portion, it is difficult for the gear housing to open, and a decrease in durability due to poor meshing between the drive gear and the driven gear (or idler gear) is suppressed. Further, according to the second invention, since the first gear housing fastening portion is located relatively close to the drive gear, the opening of the gear housing is less likely to occur, and a bolt used for the fastening is dropped off. Is less likely to occur. Further, according to the third aspect, the opening of the gear housing due to the bending of the second gear housing fastening portion is less likely to occur. Further, according to the fourth invention, it is difficult for the electric motor to fall down due to the bending of the first motor fastening portion and the second motor fastening portion. Further, according to the fifth aspect, the axial fall of the electric motor due to the bending of the second motor fastening portion is less likely to occur. According to the sixth aspect of the invention, the second gear housing half (that is, the motor cylinder device) can be reduced in weight.

1 is a schematic view of an electric vehicle according to an embodiment. It is a hydraulic circuit diagram of the brake fluid pressure generator according to the embodiment. It is a perspective view of a motor cylinder concerning an embodiment. It is the side view which cut the important section of the motor cylinder concerning an embodiment. It is a front view of the gear housing which concerns on embodiment. It is a perspective view from the diagonal front of the gear housing which concerns on embodiment. It is a perspective view from the diagonally rear of the gear housing which concerns on embodiment.

  Hereinafter, an embodiment in which the present invention is applied to an electric brake device of an electric vehicle will be described with reference to the drawings.

<< Configuration of Embodiment >>
<Overall configuration of automobile>
1 includes a pair of left and right front wheels 2 and a pair of left and right rear wheels 3, and drive shafts 4, 4 ( The motor / generator 5 is connected to the left and right half shafts via a differential mechanism (not shown).

  The motor / generator 5 serves as both a traveling motor and a regenerative generator. The battery 7 serving as a secondary battery is used as a power storage unit, and the power supply from the battery 7 and the power supply (charging) to the battery 7 are performed by the inverter 10. ), And at the time of deceleration, the decelerating energy is converted into electric power and regenerated to generate regenerative braking force.

  In addition, the automobile 1 is provided with an ECU (Electronic Control Unit) 6 that includes a control circuit using a CPU and various electrical components and performs various controls including braking force distribution. The inverter 10 is electrically connected to the ECU 6. In the case of an electric vehicle, this configuration (or a configuration in which a motor / generator for driving the rear wheel 3 is provided) may be used. However, in the case of a hybrid vehicle, the drive shaft 4 has an engine E indicated by a two-dot chain line. The output shaft is connected. The automobile 1 in FIG. 1 is an example of front-wheel drive, but it can also be 4-wheel drive.

  Brake discs 2a, 3a that rotate integrally with the wheels (front wheels 2, rear wheels 3) and brakes 2a, 3a are sandwiched between the front wheels 2 and the rear wheels 3 as friction braking means for performing friction braking. A disc brake composed of calipers 2b and 3b is provided. A brake fluid pressure generating device 8 is connected to the brake calipers 2b and 3b via a known brake pipe. The brake fluid pressure generator 8 is constituted by a hydraulic circuit capable of distributing different brake pressures for the respective wheels 2 and 3. The front wheel 2 and the rear wheel 3 are each provided with a wheel speed sensor 9 for detecting a wheel speed, while the brake pedal 11 is provided with a stroke sensor 11a for detecting a stepping operation amount. A detection signal of the stroke sensor 11a is input to the ECU 6.

  When the brake pedal 11 is depressed (that is, when the output signal of the stroke sensor 11a exceeds a predetermined value), the ECU 6 determines that a braking command has been generated and performs braking control. In the illustrated example, regenerative cooperative control using both regenerative braking and hydraulic braking is performed by a brake-by-wire system.

<Brake fluid pressure generator>
Next, the brake fluid pressure generator 8 will be described with reference to FIG. The brake fluid pressure generating device 8 of the present embodiment does not mechanically transmit the operation of the brake pedal 11 as a braking operation member to the master cylinder to generate the brake fluid pressure. (Displacement amount) is detected by a stroke sensor 11a, and based on the detected value, a brake fluid pressure is generated by a motor cylinder 13 using an electric servo motor (hereinafter referred to as an electric motor) 12 as a drive source. It is comprised by the wire.

As shown in FIG. 2 , one end of a rod 14 that converts the arc motion into a substantially linear motion is connected to the brake pedal 11 that is rotatably supported by the vehicle body, and the other end of the rod 14 is the master. The first master cylinder piston 15a of the cylinder 15 is engaged so as to be pushed in. The master cylinder 15 has a second master cylinder piston 15b arranged in series on the side opposite to the rod 14 with respect to the first master cylinder piston 15a, and both the master cylinder pistons 15a and 15b are arranged on the rod 14 side. Spring biased. Note that the brake pedal 11 is always spring-biased in the return direction, and is locked at an initial position (position shown in FIG. 2 ) by a stopper (not shown) when not depressed.

  The master cylinder 15 is provided with a reservoir tank 16 for supplying and discharging brake fluid according to the displacement of the master cylinder pistons 15a and 15b. Each master cylinder piston 15a, 15b is provided with a seal member at an appropriate position for sealing between the oil passages 16a, 16b communicating with the reservoir tank 16. In the cylinder of the master cylinder 15, a first liquid chamber 17a is formed between the first master cylinder piston 15a and the second master cylinder piston 15b, and the first master cylinder piston 15a of the second master cylinder piston 15b. A second liquid chamber 17b is formed on the side opposite to the above.

  On the other hand, the electric motor 12, the reduction gear mechanism 18 connected to the electric motor 12, and the rotational force of the electric motor 12 are transmitted to the motor cylinder 13 via the reduction gear mechanism 18 and the ball screw mechanism 29. A screw shaft 19 that is displaced in the axial direction, and a first motor cylinder piston 21 a and a second motor cylinder piston 21 b that are arranged coaxially and in series with the screw shaft 19 are provided.

The second motor cylinder piston 21b is fixed with one end of a connecting member 20 extending toward the first motor cylinder piston 21a, and the other end of the connecting member 20 is connected to the first motor cylinder piston 21a. Thus, it is supported so that it can be displaced by a predetermined amount in the axial direction. As a result, the first motor cylinder piston 21a can move forward (move toward the second motor cylinder piston 21b) independently of the second motor cylinder piston 21b. However, the connecting member 20 can be moved back to the initial state of FIG. Then, the second motor cylinder piston 21b is also pulled back to the initial position. The two motor cylinder pistons 21a and 21b are always urged toward the screw shaft 19 by the two return springs 27a and 27b provided in correspondence with each other.

  The motor cylinder 13 is provided with two oil passages 22a and 22b communicating with the reservoir tank 16 through the communication passage 22, respectively. Both the motor cylinder pistons 21a and 21b have both oil passages 22a. , 22b is provided with a sealing member in place. In the cylinder of the motor cylinder 13, a first hydraulic pressure generating chamber 23a is formed between the first motor cylinder piston 21a and the second motor cylinder piston 21b, and the first motor cylinder piston 21a of the second motor cylinder piston 21b. A second hydraulic pressure generating chamber 23b is formed on the side opposite to the above.

  In the case of the present embodiment, the first liquid chamber 17a of the master cylinder 15 communicates with the first hydraulic pressure generation chamber 23a of the motor cylinder 13 via the normally open solenoid valve 24a, and the second liquid chamber 17b is normally open. Are respectively connected to the second hydraulic pressure generating chamber 23b of the motor cylinder 13 through the electromagnetic valve 24b. A brake pressure sensor 25a on the master cylinder 15 side is connected between the first liquid chamber 17a and the electromagnetic valve 24a, and a motor cylinder 13 side is connected between the electromagnetic valve 24b and the second hydraulic pressure generation chamber 23b. A brake pressure sensor 25b is connected.

Further, a stepping reaction force generating simulator 28 is connected between the second liquid chamber 17b and the electromagnetic valve 24b through a normally closed electromagnetic valve 24c. The simulator 28 is a piston 28a is decorated partitioning impulse freely within its cylinder, the liquid storage chamber 28b is formed in the electromagnetic valve 24 c side of the piston 28a, the liquid reservoir chamber 28 b side of the piston 28a is A compression coil spring 28c is accommodated on the opposite side. With both the solenoid valves 24a and 24b closed and the solenoid valve 24c opened, the brake pedal 11 is depressed to cause the brake fluid in the second fluid chamber 17b to enter the fluid storage chamber 28b, whereby the compression coil spring 28c is attached. The force is transmitted to the brake pedal 11, whereby a reaction force (pedal depression force) against the depression similar to that of a brake device in which a known master cylinder and wheel cylinder are directly connected is obtained.

Furthermore, the first hydraulic pressure generation chamber 23a and the second hydraulic pressure generation chamber 23b of the motor cylinder 13 are each provided in plural (four in the illustrated example) via oil passages 22e and 22f provided with the VSA device 26, respectively. Piping is made so as to communicate with the brake calipers 2b and 3b. The VSA device 26 includes ABS for preventing wheel lock during braking, TCS (traction control system) for preventing wheel slipping during acceleration, yaw moment control during turning, brake assist function, collision avoidance, lane keeping, etc. Since it is a well-known vehicle behavior stabilization control system equipped with an automatic brake function and the like, detailed description of its structure is omitted. The VSA device 26 includes brake actuators using various hydraulic elements that respectively constitute a first system corresponding to both brake calipers 2b for the front wheels and a second system corresponding to both brake calipers 3b for the rear wheels, And a VSA control unit 26a for controlling them.

  The brake fluid pressure generator 8 is comprehensively controlled by the ECU 6. The ECU 6 receives detection signals from the stroke sensor 11a and the brake pressure sensors 25a and 25b, and also receives detection signals from various sensors (not shown) for detecting the behavior of the vehicle. The ECU 6 controls the brake fluid pressure generated by the motor cylinder 13 based on the detection signals from the stroke sensor 11a and in accordance with the running conditions determined from the detection signals from these various sensors. Further, in the case of a hybrid vehicle (or an electric vehicle) that is a target vehicle of the present embodiment, regenerative control is performed by a motor / generator, and the ECU 6 is a motor for the magnitude of regeneration when performing regenerative control. Brake fluid pressure distribution control by the cylinder 13 is also performed.

<Outside of motor cylinder>
Next, the outer shell (housing) of the motor cylinder 13 will be described with reference to FIGS. In addition, about each member which comprises a housing, the up-down, left-right, front-back is shown with the arrow in FIG.

  As shown in FIGS. 3 and 4, the motor cylinder 13 includes a cylinder body 31, a gear housing 32 fastened to the rear end of the cylinder body 31, a motor assembly 33 fastened to the upper front of the gear housing 32, An outer shell is formed from a reservoir 34 (not shown in FIG. 4) fixed to the upper portion of the cylinder body 31. The gear housing 32 according to the present embodiment includes a first gear housing half 35 to which the cylinder body 31 and the motor assembly 33 are fastened, and a second gear housing half 36 fastened to the rear surface of the first gear housing half 35. ing.

  As shown in FIG. 2, the cylinder body 31 houses both the motor cylinder pistons 21a and 21b so as to be slidable, and also houses a connecting member 20 and return springs 27a and 27b. The gear housing 32 also serves as a ball screw housing. As shown in FIGS. 2 and 4, a reduction gear mechanism 18 and a ball screw mechanism 29 are provided between the gear housing halves 35 and 36 (inside). Is retained.

  As shown in FIG. 4, the motor assembly 33 includes an electric motor 12 having a drive gear 41 fixed to the tip of the shaft 12 a and a motor mount 37 for fixing the electric motor 12 to the first gear housing half 35. doing. The motor mount 37 includes a power supply circuit that supplies electric power from the ECU 6 to the electric motor 12 and a rotation sensor that detects a rotation state of the electric motor 12 and outputs a detection signal to the ECU 6.

  The reduction gear mechanism 18 is formed on the outer periphery of the drive gear 41 described above, the idler gear 42 rotatably supported by the first and second gear housing halves 35 and 36, and the nut 46 (described later) of the ball screw mechanism 29. In addition, the driven gear 43 having a relatively large diameter is meshed in this order, and the rotation of the electric motor 12 is decelerated (that is, the torque is increased) and transmitted to the ball screw mechanism 29.

  The ball screw mechanism 29 includes a nut 46 rotatably supported by the first and second gear housing halves 35 and 36 via a pair of radial bearings 45, and a screw shaft screwed onto the nut 46 via a ball (not shown). 19, and the nut 46 is driven to rotate by the electric motor 12 via the reduction gear mechanism 18, thereby moving the screw shaft 19 forward and backward in the axial direction. In the drawing, a member denoted by reference numeral 47 is a guide pin that is press-fitted into the rear end of the screw shaft 19, and in a guide groove 48 formed in the second gear housing half 36 to prevent the screw shaft 19 from rotating. Engage in an axially slidable manner.

<First gear housing half>
As shown in FIGS. 5 and 6, a cylinder support portion 51 into which the rear end portion of the cylinder body 31 is fitted is projected forward at the lower front portion of the first gear housing half 35. A pair of left and right cylinder fastening portions 54 and 55 each having a female screw hole 53 are extended from the rear end. As shown in FIGS. 3 and 4, hexagon bolts (hereinafter simply referred to as bolts) 56 for fastening the cylinder body 31 are screwed into the female screw holes 53 of the cylinder fastening portions 54 and 55. In addition, a relatively large-diameter driven gear storage part 58 is provided in the lower part of the gear housing 32 so as to accommodate the driven gear 43, and a screw shaft housing for accommodating the screw shaft 19 at the rear end of the driven gear storage part 58. A convex part 59 is provided in a protruding manner.

  As shown in FIGS. 5 and 6, a motor holding recess 61 into which the rear end of the electric motor 12 is fitted is formed on the upper front surface of the first gear housing half 35. Upper motor fastening portions 63 and 64 and lower motor fastening portions 65 and 66 each having a female screw hole 62 project outward in the radial direction. The upper motor fastening portions 63 and 64 are positioned at the upper end of the first gear housing half 35, and the lower motor fastening portions 65 and 66 are formed at substantially the same position as the center of the motor holding recess 61 in the vertical direction. . As shown in FIG. 3, bolts 67 for fastening the motor assembly 33 are screwed into the three motor fastening portions 63, 65, and 66. In the present embodiment, the upper motor fastening portion 64 on the right side is not used.

  As shown by a broken line in FIG. 5, the first gear housing half 35 has one upper fastening portion 71 (bolt hole), a pair of left and right intermediate fastening portions 72 and 73 (bolt holes), and a pair of left and right sides. Lower fastening portions (bolt holes) 74 and 75 are formed. The upper fastening portion 71 is located in a bolt housing recess 77 formed immediately above the drive gear insertion hole 76 in the motor holding recess 61. Moreover, the intermediate | middle fastening parts 72 and 73 are located in the meshing site | part of the idler gear 42 and the driven gear 43 in an up-down direction so that FIG. 4, FIG. 6 may show. The lower fastening portions 74 and 75 are located at the lower end of the first gear housing half 35. A shank of a bolt 78 that is screwed into a female screw hole (not shown) formed in the second gear housing half 36 passes through each of the fastening portions 71 to 75.

  As shown in FIGS. 5 and 6, in the first gear housing half 35, the left upper motor fastening portion 63 and the lower motor fastening portion 65 are connected by a connecting rib 81, and the right upper motor fastening portion 64 and the lower motor are connected. The fastening portion 66 is connected by a connecting rib 82. Further, the left lower motor fastening portion 65 and the driven gear storage portion 58 are connected by a connecting rib 83, and the right lower motor fastening portion 66 and the driven gear storage portion 58 are connected by a connecting rib 84.

<Second gear housing half>
As shown in FIGS. 6 and 7, in the second gear housing half 36, the portion corresponding to the intermediate fastening portion 72 on the left side of the first gear housing half 35 and the driven gear storage portion 58 are connected by the connecting rib 85, and the right side A portion corresponding to the intermediate fastening portion 73 and the driven gear storage portion 58 are connected by a connecting rib 86.

  Further, as shown in FIG. 7, on the rear surface of the second gear housing half 36, there are three central thinning recesses 91 to 93 extending in the vertical direction directly above the driven gear storage portion 58, and these central thinning recesses 91 to 91. 93, lateral side hollowing recesses 94, 95 formed on the left and right sides, lateral end side hollowing recesses 96, 97 formed obliquely to the lateral side hollowing recesses 94, 95, and lateral side hollowing recesses 94, 95 and 99 are formed in the lower hollow portions 98 and 99 formed below 95.

<< Operation of Embodiment >>
When the driver depresses the brake pedal 11 while the vehicle is traveling, the ECU 6 determines the braking control amount based on the stepping operation amount detected by the stroke sensor 11a and the vehicle speed obtained from the detection value of each wheel speed sensor 9, and the motor. A drive current is output to the electric motor 12 of the cylinder 13. Then, in the motor cylinder 13, the electric motor 12 starts rotating and the torque is transmitted to the ball screw mechanism 29 via the reduction gear mechanism 18, and the screw shaft 19 moves to the left in FIG. 21a and 21b are pressed. As a result, a predetermined brake fluid pressure is generated in the motor cylinder 13, brake fluid is supplied to the brake calipers 2b and 3b, and the wheels 2 and 3 are braked with a predetermined braking force.

  During braking, in the reduction gear mechanism 18, the reaction force when driving the ball screw mechanism 29 acts on the drive gear 41 via the idler gear 42, and a large repulsive force acts on the cantilever drive gear 41 (ie, The force which inclines the shaft 12a of the electric motor 12 acts). However, in the present embodiment, since the first gear housing half 35 and the second gear housing half 36 are fastened by the upper fastening portion 71 provided immediately above the drive gear 41, a large repulsive force is exerted on the drive gear 41. Even if it acts, the bending (namely, opening of the gear housing 32) does not occur. As a result, good engagement between the drive gear 41 and the idler gear 42 is ensured, and a reduction in durability of the reduction gear mechanism 18 (that is, the motor cylinder 13) is effectively suppressed. In addition, since the bolt 78 of the upper fastening portion 71 faces the end surface of the electric motor 12 in the motor holding recessed portion 61, dropping or the like due to loosening is prevented.

On the other hand, when the vehicle is traveling on a rough road, the electric motor 12 causes relative vibration between the electric motor 12 and the gear housing 32 due to its inertia, thereby deteriorating the meshing between the drive gear 41 and the idler gear 42 described above. There is a risk of causing metal fatigue on the side. However, in this embodiment, the motor fastening portion 63-6 6 of the left and right first gear housing half 35 is connected to each other by connecting ribs 81 and 82, is connected to the driven gear housing portion 58 by a connecting rib 83 and 84 For this reason, the rigidity of the gear housing 32 becomes very high due to the presence of the connecting ribs 85 and 86 also on the second gear housing half 36 side, and the relative vibration described above is effectively suppressed.

  The motor cylinder 13 is supported on the body panel and the cross member via a bracket (not shown). However, if the weight of the motor cylinder 13 is large, the bracket or the like needs to have high rigidity and strength. However, in the present embodiment, since the multiple hollow recesses 91 to 99 are formed in the second gear housing half 36, the weight of the gear housing 32 (that is, the motor cylinder 13) can be made relatively small, A bracket that is relatively small and can be measured can be used.

  This is the end of the description of specific embodiments. However, aspects of the present invention are not limited to these embodiments. For example, in the above embodiment, one upper fastening portion is provided immediately above the drive gear, but a pair of left and right upper fastening portions may be provided obliquely above the left and right of the drive gear, or above the motor holding recess. An upper fastening portion may be provided. In addition, a shape and number different from those of the above-described embodiment may be adopted for the connecting ribs and the installation portions of the lightening recesses, or at least one of them may be omitted. In addition, the specific configuration and shape of the motor cylinder and gear housing can be set as appropriate without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 12 Electric motor 13 Motor cylinder 18 Reduction gear mechanism 19 Screw shaft 29 Ball screw mechanism 31 Cylinder body 32 Gear housing 33 Motor assembly 35 First gear housing half 36 Second gear housing half 37 Motor mount 41 Drive gear 42 Idler gear 43 Driven gear 46 Nut 56 Bolt 58 Driven Gear Housing 59 59 Screw Shaft Housing Convex 61 Motor Holding Concave 62 Female Screw Hole 63, 64 Upper Motor Fastening Portion 65, 66 Lower Motor Fastening Portion 67 Bolt 71 Upper Fastening Portion 72 Intermediate Fastening Portion 74 Lower Fastening Portion 77 Bolt Housing Recessed portion 78 Bolt 81-86 Connecting rib 91-99 Meat recessed portion

Claims (5)

An electric motor that is driven and controlled according to the driver's depression of the brake pedal, a reduction gear mechanism that transmits the torque of the drive gear fixed to the shaft of the electric motor to the driven gear, and the torque of the driven gear is transmitted to the screw shaft. A motor cylinder device for an electric brake comprising a ball screw mechanism that converts to a thrust and a brake cylinder that receives a thrust of the screw shaft and generates a brake fluid pressure,
A cylinder main body that forms an outline of the brake cylinder;
A first gear housing half connected to an end of the cylinder body on the ball screw mechanism side;
A second gear housing half that is fastened to a side of the first gear housing half that is separated from the cylinder body in a plurality of gear housing fastening portions, and that forms a gear housing that houses at least the reduction gear mechanism together with the first gear housing half. And
The electric motor is fastened to a plurality of motor fastening portions provided on one of the first gear housing half and the second gear housing half,
The gear housing fastening portion, at least one of the first gear housing fastening portion, a plurality of second gear housing projecting outwardly from the outer periphery of the gear housing which is arranged on the opposite side of the driven gear across the front Stories drive gear A fastening portion,
Of the first gear housing half and the second gear housing half, a motor holding recess into which an end of the electric motor is fitted is formed on the side where the electric motor is fastened.
A motor cylinder device for an electric brake , wherein a head portion of a bolt provided for fastening at the first gear housing fastening portion faces an end surface of the electric motor in the motor holding recess . Before SL connecting ribs connecting the outer periphery of the driven gear housing portion definitive the second gear housing fastening portion and the front firewood Yahaujin grayed is characterized in that provided by an electric brake motor cylinder device according to claim 1. The electric motor is fastened to a plurality of the motor fastening portion provided in the first gear housing half,
The motor fastening portion includes a first motor fastening portion protruding from an outer periphery of the first gear housing half on the opposite side of the driven gear across the drive gear, and the same side as the driven gear with respect to the first motor fastening portion And a second motor fastening portion projecting from the outer periphery of the first gear housing half,
3. The electric brake according to claim 1, wherein the first gear housing half is provided with a connecting rib that connects the first motor fastening portion and the second motor fastening portion. Motor cylinder device. Wherein the first gear housing half, characterized in that the connection rib connecting the outer periphery of the driven gear housing portion in the first gear housing half and the second motor fastening portion is provided, according to claim 3 Motor cylinder device for electric brakes. The second gear housing half, said characterized in that it has a plurality of lightening recesses in the surface on the side away from the cylinder body, electric brake according to any one of claims 1 to 4 Motor cylinder device.

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