WO2021002150A1 - Electric brake device - Google Patents

Electric brake device Download PDF

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Publication number
WO2021002150A1
WO2021002150A1 PCT/JP2020/022515 JP2020022515W WO2021002150A1 WO 2021002150 A1 WO2021002150 A1 WO 2021002150A1 JP 2020022515 W JP2020022515 W JP 2020022515W WO 2021002150 A1 WO2021002150 A1 WO 2021002150A1
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WO
WIPO (PCT)
Prior art keywords
lock nut
piston
brake device
electric brake
screw shaft
Prior art date
Application number
PCT/JP2020/022515
Other languages
French (fr)
Japanese (ja)
Inventor
公俊 緒方
小野　雅彦
大野　耕作
谷江　尚史
Original Assignee
日立オートモティブシステムズ株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
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Application filed by 日立オートモティブシステムズ株式会社 filed Critical 日立オートモティブシステムズ株式会社
Priority to DE112020002730.9T priority Critical patent/DE112020002730T5/en
Publication of WO2021002150A1 publication Critical patent/WO2021002150A1/en

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D65/00—Parts or details
    • F16D65/14—Actuating mechanisms for brakes; Means for initiating operation at a predetermined position
    • F16D65/16—Actuating mechanisms for brakes; Means for initiating operation at a predetermined position arranged in or on the brake
    • F16D65/18—Actuating mechanisms for brakes; Means for initiating operation at a predetermined position arranged in or on the brake adapted for drawing members together, e.g. for disc brakes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
    • B60T13/74—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with electrical assistance or drive
    • B60T13/741—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with electrical assistance or drive acting on an ultimate actuator
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2121/00—Type of actuator operation force
    • F16D2121/18—Electric or magnetic
    • F16D2121/24—Electric or magnetic using motors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2125/00—Components of actuators
    • F16D2125/18—Mechanical mechanisms
    • F16D2125/20—Mechanical mechanisms converting rotation to linear movement or vice versa
    • F16D2125/34—Mechanical mechanisms converting rotation to linear movement or vice versa acting in the direction of the axis of rotation
    • F16D2125/40—Screw-and-nut
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2125/00—Components of actuators
    • F16D2125/18—Mechanical mechanisms
    • F16D2125/44—Mechanical mechanisms transmitting rotation
    • F16D2125/46—Rotating members in mutual engagement
    • F16D2125/48—Rotating members in mutual engagement with parallel stationary axes, e.g. spur gears
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H25/00—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms
    • F16H25/18—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms for conveying or interconverting oscillating or reciprocating motions
    • F16H25/20—Screw mechanisms

Definitions

  • the present invention relates to an electric brake device provided in a vehicle such as an automobile and operated based on the drive of an electric motor.
  • Patent Document 1 As an electric brake device used for a vehicle such as an automobile, for example, the technique described in Patent Document 1 is known.
  • a substantially cylindrical piston having an opening on one side is slidably arranged in a cylinder formed in a caliper, and a substantially cylindrical lock nut is inserted from the open end of the piston. Driven in the axial direction.
  • the lock nut is configured to abut against the inner wall surface of the piston and press the piston toward the brake pad, and the tip of the lock nut is formed so as to elastically deform when abutting against the inner wall surface of the piston.
  • a deformed portion is provided.
  • the piston and the lock nut are provided with a regulation structure for restricting the elastic deformation of the deformed portion so that the elastic deformation amount of the deformed portion is less than the elastic limit value in the bending direction.
  • Patent Document 1 it is possible to allow axial deviation from the piston due to elastic deformation of the tip of the lock nut.
  • the contact with the piston is in a partial contact (one-sided contact) state, and the piston is displaced and tilted.
  • the misalignment and tilt caused by the piston are transmitted to the lock nut that contacts the inner surface of the piston.
  • the stress caused by the shaft misalignment and eccentricity of the piston is newly generated, and the life of the electric brake is shortened. There was a problem such as becoming.
  • An object of the present invention is to provide an electric braking device capable of suppressing bending deformation occurring in a component while maintaining a contact state between a lock nut and a piston while allowing shaft misalignment with the piston. ..
  • the present invention provides a piston that comes into contact with a brake pad, a screw shaft that transmits the rotation of an electric motor, and a screw shaft that is provided inside the piston and moves by the rotation of the screw shaft to move the piston.
  • An electric brake device including a lock nut for pressing, the lock nut includes a pressing portion for pressing the piston, a screw cylinder portion for screwing with the screw shaft, and the pressing portion and the screw cylinder. It has an intermediate portion located between the portions, and the intermediate portion is characterized in that an elastically deformed portion having a lower rigidity than the other portion of the lock nut is formed.
  • an electric brake device capable of suppressing bending deformation generated in a component while maintaining a contact state between a lock nut and a piston while allowing shaft misalignment with the piston. ..
  • FIG. 7 is a cross-sectional view taken along the line AA of FIG.
  • FIG. 7 is a cross-sectional view taken along the line AA of FIG. 7 according to a modified example. It is sectional drawing of the piston, the lock nut, and the screw shaft portion which concerns on 3rd Example of this invention.
  • FIG. 10 is a cross-sectional view taken along the line BB of FIG. It is sectional drawing of the piston, the lock nut, and the screw shaft portion which concerns on 4th Embodiment of this invention.
  • FIG. 12 is a cross-sectional view taken along the line CC of FIG. It is a CC sectional view of FIG. 12 which concerns on a modification. It is sectional drawing of the piston, the lock nut, and the screw shaft portion which concerns on 5th Embodiment of this invention.
  • FIG. 15 is a sectional view taken along line DD of FIG.
  • FIG. 1 is a cross-sectional view of an electric brake device according to a first embodiment of the present invention
  • FIG. 2 is a cross-sectional view of a piston, a lock nut, and a screw shaft portion according to the first embodiment of the present invention.
  • a cylinder 10 is formed inside the caliper 1, and a piston 7 is slidably arranged in the cylinder 10.
  • the piston 7 has a substantially cylindrical shape with one side open, and a lock nut 6 and a screw shaft 5 screwed by a screw portion 22 are inserted inside the piston 7.
  • the upper part of the caliper 1 is closed and the lower part is opened, and the brake pad is stored in the opened part.
  • the lock nut 6 is arranged so that the central axis of the screw cylinder portion 6b is in the horizontal direction.
  • the screw shaft 5 is arranged so that the central axis is in the horizontal direction.
  • the ECU engine control unit
  • the screw shaft 5 is fixed to the caliper 1 via a thrust bearing 11, and the rotation of the electric motor 4 is transmitted to the screw shaft 5 via the speed reducer 3.
  • the rotation of the screw shaft 5 in the apply direction causes the lock nut 6 to move forward (move) toward the inner surface side (bottom side) of the piston 7, so that the lock nut 6 and the piston 7 come into contact with each other at the contact portion 21. By this contact, the piston 7 advances, and the outer surface side of the piston 7 comes into contact with the brake pad 8.
  • the contact portion 21 is inclined so that the apply direction side faces the center of the lock nut 6. Further, when the rotational drive of the electric motor 4 in the apply direction is continued, the piston 7 presses the brake pad 8 by the movement of the lock nut 6, and the disc rotor 9 is arranged on the claw portion 12 side of the caliper 1. By sandwiching it with 8, a thrust force, which is a braking force, is generated.
  • the lock nut 6 constituting the rotation linear motion conversion mechanism 30 has a screw cylinder portion having a pressing portion 6a for pressing the piston 7 and a screw portion 22 screwing with the screw shaft 5. It is composed of 6b and an intermediate portion 6c provided between the pressing portion 6a and the screw cylinder portion 6b, and the intermediate portion 6c is formed from other parts of the lock nut 6 (pressing portion 6a, screw cylinder portion 6b). Also, an elastically deformed portion 23 having low rigidity is formed. Regarding the rigidity of the elastically deformed portion 23, it is particularly desirable that the bending rigidity is small.
  • the pressing portion 6a is set to a position where the size in the radial direction is formed larger than that of the screw cylinder portion 6b.
  • the screw cylinder portion 6b is from the opening side of the piston 7 in the lock nut 6 to the position of the end portion of the screw portion 22.
  • the intermediate portion 6c is set to a position from the end portion of the screwed portion 22 to the pressing portion 6a whose size changes in the radial direction.
  • FIG. 3 is a cross-sectional view showing the deformation of the caliper 1 when the thrust of the electric brake device is generated. Since the claw portion 12 of the caliper 1 is in a state of a cantilever with one end side of the caliper 1 fixed, the thrust transmitted from the brake pad 8 is applied to the inner surface of the claw portion 12 of the caliper 1, which is shown in FIG. Bending deformation occurs in the direction of arrow 13 of 3. When the claw portion 12 of the caliper 1 is bent and deformed, the piston 7 moves while following the deformation, so that the piston 7 is displaced and tilted. Another factor that causes the piston 7 to be misaligned and tilted is shown.
  • FIG. 4 is a cross-sectional view of the electric brake device when the brake pads are worn.
  • One-sided wear 14 occurs on the brake pad 8 due to aged deterioration of the electric brake device or the like. Since the caliper 1 is bent and deformed in the direction of the arrow 13 in FIG. 3, the brake pad 8 is pieced so that the gap gradually widens from the open side to the fixed side (from the lower side to the upper side in FIG. 4) of the caliper 1. Wear out.
  • the piston 7 presses the one-sided worn brake pad 8 when thrust is applied, and the piston 7 is displaced and tilted following the wear shape of the brake pad 8. There is concern about doing so.
  • FIG. 5 is a cross-sectional view of the piston and the rotational linear motion conversion mechanism portion when the piston is displaced or tilted according to the first embodiment of the present invention.
  • the contact portion 21 between the lock nut 6 and the piston 7 follows the axial deviation and inclination of the piston 7, so that the entire contact can be maintained. That is, it is possible to prevent the contact portion 21 from hitting one side and improve the wear resistance. Further, it can be expected that one-sided contact with the thrust bearing 11 located on the rear end side of the elastically deformed portion 23 is suppressed to improve wear resistance, and a highly reliable electric braking device can be provided.
  • the method of forming the elastically deformed portion 23 of the lock nut 6 can be realized, for example, by forming another member having a material different from that of the lock nut 6 and having a low rigidity by sandwiching it by interfacial bonding or adhesion.
  • FIG. 6 shows a modified example.
  • FIG. 6 is a cross-sectional view of a piston, a lock nut, and a screw shaft portion according to a modified example of the first embodiment.
  • the length of the intermediate portion 6c formed between the pressing portion 6a and the screw cylinder portion 6b is formed longer than that in FIG. Then, in the modified example, the position of the elastically deformed portion 23 formed in the intermediate portion 6c is arranged closer to the screwed cylinder portion 6b side as compared with FIG. It goes without saying that the same effect can be obtained with respect to the formed portion of the elastically deformed portion 23 if it is between the contact portion 21 and the screwed portion 22.
  • FIG. 7 is a cross-sectional view of a piston, a lock nut, and a screw shaft portion according to a second embodiment of the present invention.
  • FIG. 8 is a cross-sectional view taken along the line AA of FIG.
  • FIG. 9 is a cross-sectional view taken along the line AA of FIG. 7 according to a modified example.
  • the difference from the first embodiment is that as the elastically deformed portion 23 of the lock nut 6, a thin portion 24 thinner than the plate thickness of the other portion of the lock nut 6 is formed.
  • An intermediate portion 6c between the pressing portion 6a and the screw cylinder portion 6b is formed with a thin portion 24 thinner than the plate thickness of the pressing portion 6a and the screw cylinder portion 6b.
  • the thin portion 24 is formed on the opening side (lower side in FIGS. 7 and 8) and the opposite side (upper side in FIGS. 7 and 8) in which the brake pad 8 and the disc rotor 9 of the caliper 1 are stored. There is.
  • the thin-walled portion 24 can be formed, for example, by cutting a part of the outer circumference of the lock nut.
  • the thin portion 24 is formed by notching the upper side and the lower side of the outer peripheral surface of the lock nut 6.
  • the thin portion 24 includes a small diameter portion having a diameter smaller than the outer peripheral diameter of the intermediate portion 6c of the lock nut 6. Since the piston 7 is misaligned and tilted due to one-sided wear of the brake pad 8, it occurs on the opening side (lower side of FIGS. 7 and 8) and the opposite side (upper side of FIGS. 7 and 8) of the caliper 1.
  • the thin portion 24 may be formed at least above and below the outer circumference of the lock nut.
  • the lock nut can be formed as an integral member by, for example, forging, it is possible to reduce the shaft deviation of the lock nut due to variations in processing accuracy and assembly. Further, the thin portion 24 can be formed by an easy method of cutting, and improvement in workability can be expected. This makes it possible to provide a more highly reliable electric brake device.
  • the thin portion 24 may be formed over the entire circumference of the outer circumference of the lock nut 6.
  • the entire circumference of the outer circumference of the lock nut 6 is cut by cutting to reduce the diameter of the lock nut 6.
  • FIG. 10 is a cross-sectional view of a piston, a lock nut, and a screw shaft portion according to a third embodiment of the present invention.
  • FIG. 11 is a cross-sectional view taken along the line BB of FIG.
  • the thin-walled portion 24 as the elastically deformed portion 23 of the lock nut 6 is formed by cutting the inner peripheral side of the cylinder.
  • a thin portion 24 thinner than the plate thickness of the pressing portion 6a and the screw cylinder portion 6b is formed in the intermediate portion 6c between the pressing portion 6a and the screw cylinder portion 6b.
  • the thin portion 24 is formed on the inner peripheral side of the lock nut 6.
  • the thin-walled portion 24 can be formed, for example, by cutting the entire inner circumference of the lock nut. By cutting the entire inner circumference of the lock nut 6, the inner circumference of the lock nut 6 is increased in diameter.
  • the thin portion 24 includes a large diameter portion having a diameter larger than the inner peripheral diameter of the intermediate portion 6c of the lock nut 6.
  • the elastically deformed portion 23 of the lock nut 6 is formed by cutting the inner peripheral side of the cylinder to make it thinner, and the bending rigidity is small in any direction, so that the piston 7 is displaced. , The influence of inclination can be absorbed by the elastically deformed portion 23. As a result, it is possible to prevent the stress increase of the screwed portion 22 of the lock nut 6 and the screw shaft 5 and the one-sided contact of the thrust bearing 11.
  • FIG. 12 is a cross-sectional view of a piston, a lock nut, and a screw shaft portion according to a fourth embodiment of the present invention.
  • FIG. 13 is a cross-sectional view taken along the line CC of FIG.
  • FIG. 14 is a cross-sectional view taken along the line CC of FIG. 12 according to a modified example.
  • the difference from the first to third embodiments is that the elastically deformed portion 23 of the lock nut 6 is formed by the through hole 25.
  • a through hole 25 is formed in the intermediate portion 6c between the pressing portion 6a and the screw cylinder portion 6b so as to penetrate the inner circumference from the outer circumference of the lock nut 6.
  • the through hole 25 is formed at an arbitrary position by drilling or the like. Since the portion where the through hole 25 is formed is hollow, the rigidity is lower than that of the other portions, and the portion is easily elastically deformed. Therefore, by adjusting the number of through holes 25 and the hole diameter, it is possible to easily configure the elastically deformed portion 23 so as to have an arbitrary bending rigidity.
  • a plurality of through holes 25 as elastically deformed portions 23 are formed vertically and horizontally when the lock nut 6 is viewed from the central axis direction.
  • the lock nut 6 is formed with a through hole 25 as the elastically deformed portion 23, the influence of the axial deviation and inclination of the piston 7 is absorbed by the through hole 25 as the elastically deformed portion 23. Can be done.
  • the through hole 25 may be formed non-uniformly in the circumferential direction as shown in FIG.
  • the number of through holes 25 formed at the top and bottom is made larger than the number of through holes 25 formed at the left and right.
  • the flexural rigidity of the elastically deformed portion 23 can be changed in the circumferential direction. Since the piston 7 is misaligned and tilted due to one-sided wear of the brake pad 8, it occurs on the opening side (lower side of FIGS. 12 and 14) of the caliper 1 and the opposite side (upper side of FIGS. 12 and 14). It is preferable that the number of through holes 25 formed at the top and bottom is larger than the number of through holes 25 formed at the left and right. In addition to changing the number of through holes 25, the hole diameter may be changed.
  • the influence of the axis deviation and inclination of the piston 7 can be easily absorbed by increasing the number of through holes 25 and the hole diameter, and the axis deviation and inclination of the piston 7 are small.
  • the number of through holes 25 and the hole diameter can be reduced to prevent the lock nut 6 from becoming excessively rigid.
  • FIG. 15 is a cross-sectional view of a piston, a lock nut, and a screw shaft portion according to a fifth embodiment of the present invention.
  • 16 is a cross-sectional view taken along the line DD of FIG.
  • a rotation stop portion 31 for suppressing the rotation of the lock nut 6 is formed on the outer circumference of the pressing portion 6a of the lock nut 6.
  • the rotation stop portion 31 is formed between the contact portion 21 in which the lock nut 6 contacts the piston 7 and the intermediate portion 6c (elastic deformation portion 23), and has a flat end portion formed on the inner circumference of the piston 7. I'm in contact.
  • a rotation stop portion 31 is formed on the lock nut 6, and the rotation stop portion 31 and the piston 7 are brought into contact with each other to realize rotation restraint.
  • the rotation stopper 31 acts to uniformly maintain the contact between the contact portion 21 of the piston 7 and the lock nut 6, an effect of suppressing one-sided contact of the contact portion 21 can be expected.
  • the elastically deformed portion 23 of the lock nut 6 is formed between the rotation stop portion 31 and the screwed portion 22 of the screw shaft 5. Therefore, according to the present embodiment, the elastic deformation portion 23 can absorb the axial deviation and the inclination transmitted to the lock nut 6 as in the previous embodiment.
  • the present invention is not limited to the above-mentioned examples, and includes various modifications.
  • the above-described examples have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the described configurations. It is also possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. In addition, it is possible to add, delete, or replace a part of the configuration of each embodiment with another configuration.

Abstract

The present invention addresses the problem of providing an electric brake device that is capable of suppressing bending deformation caused in a component while maintaining a contact state between a lock nut and a piston and while allowing axial deviation with the piston.　The present invention is provided with: a piston 7 making contact with a brake pad 8; a screw shaft 5 for transmitting the rotation of an electric motor 4; and a lock nut 6 that is provided inside the piston 7, moves by the rotation of the screw shaft 5, and press the piston 7. The lock nut 6 has: a pressing section 6a for pressing the piston 7; a screw cylindrical section 6b screwed to the screw shaft 5; and an intermediate section 6c positioned between the pressing section 6a and the screw cylindrical section 6b. In the intermediate section 6c, an elastic deformation section 23 is formed that has smaller stiffness than other portions of the lock nut 6.

Description

電動ブレーキ装置Electric brake device
　本発明は、自動車等の車両に設けられ、電動モータの駆動に基づいて作動する電動ブレーキ装置に関する。 The present invention relates to an electric brake device provided in a vehicle such as an automobile and operated based on the drive of an electric motor.
　自動車等の車両に用いられる電動ブレーキ装置は、例えば特許文献１に記載された技術が知られている。特許文献１のディスクブレーキ装置は、片側が開口した略円筒形状のピストンが、キャリパーに形成されたシリンダ内に摺動可能に配置され、略円筒形のロックナットが、ピストンの開口端から挿入され軸方向に駆動される。ロックナットは、ピストンの内壁面に当接してピストンをブレーキパッドに向けて押圧するように構成され、ロックナットの先端には、ピストンの内壁面への当接時に弾性変形するように形成された変形部が設けられている。さらに、変形部の弾性変形量が曲げ方向の弾性限界値未満となるように、変形部の弾性変形を規制する規制構造が、ピストンとロックナットとに設けられている。 As an electric brake device used for a vehicle such as an automobile, for example, the technique described in Patent Document 1 is known. In the disc brake device of Patent Document 1, a substantially cylindrical piston having an opening on one side is slidably arranged in a cylinder formed in a caliper, and a substantially cylindrical lock nut is inserted from the open end of the piston. Driven in the axial direction. The lock nut is configured to abut against the inner wall surface of the piston and press the piston toward the brake pad, and the tip of the lock nut is formed so as to elastically deform when abutting against the inner wall surface of the piston. A deformed portion is provided. Further, the piston and the lock nut are provided with a regulation structure for restricting the elastic deformation of the deformed portion so that the elastic deformation amount of the deformed portion is less than the elastic limit value in the bending direction.
特開２０１３－１６０２７２号公報Japanese Unexamined Patent Publication No. 2013-160272
　特許文献１では、ロックナット先端の弾性変形により、ピストンとの軸ずれを許容することができる。しかしながら、特許文献１では、ロックナット先端が局所的に変形するので、ピストンとの接触が部分接触(片当たり)状態となり、ピストンに軸ずれ、及び傾きが発生する。ピストンで生じた軸ずれ、及び傾きは、ピストンの内面で接するロックナットに伝達される。ロックナットと螺合するスクリューシャフトとの螺合部においては、ロックナットから伝わる推力に起因した応力に加え、ピストンの軸ずれ、偏心に起因した応力が新たに発生し、電動ブレーキの寿命が短くなるといった課題があった。 In Patent Document 1, it is possible to allow axial deviation from the piston due to elastic deformation of the tip of the lock nut. However, in Patent Document 1, since the tip of the lock nut is locally deformed, the contact with the piston is in a partial contact (one-sided contact) state, and the piston is displaced and tilted. The misalignment and tilt caused by the piston are transmitted to the lock nut that contacts the inner surface of the piston. At the screwed part of the screw shaft that is screwed with the lock nut, in addition to the stress caused by the thrust transmitted from the lock nut, the stress caused by the shaft misalignment and eccentricity of the piston is newly generated, and the life of the electric brake is shortened. There was a problem such as becoming.
　本発明の目的は、ピストンとの軸ずれを許容しつつ、ロックナットとピストンの接触状態を維持しながら、構成部品に発生する曲げ変形を抑制することのできる電動ブレーキ装置を提供することにある。 An object of the present invention is to provide an electric braking device capable of suppressing bending deformation occurring in a component while maintaining a contact state between a lock nut and a piston while allowing shaft misalignment with the piston. ..
　上記目的を達成するために本発明は、ブレーキパッドと当接するピストンと、電動モータの回転を伝達するスクリューシャフトと、前記ピストンの内側に備えられ、前記スクリューシャフトの回転により移動して前記ピストンを押圧するロックナットとを備えた電動ブレーキ装置であって、前記ロックナットは、前記ピストンを押圧する押圧部と、前記スクリューシャフトと螺合する螺合筒部と、前記押圧部と前記螺合筒部との間に位置する中間部とを有し、前記中間部には、前記ロックナットの他の部分よりも剛性が小さい弾性変形部を形成したことを特徴とする。 In order to achieve the above object, the present invention provides a piston that comes into contact with a brake pad, a screw shaft that transmits the rotation of an electric motor, and a screw shaft that is provided inside the piston and moves by the rotation of the screw shaft to move the piston. An electric brake device including a lock nut for pressing, the lock nut includes a pressing portion for pressing the piston, a screw cylinder portion for screwing with the screw shaft, and the pressing portion and the screw cylinder. It has an intermediate portion located between the portions, and the intermediate portion is characterized in that an elastically deformed portion having a lower rigidity than the other portion of the lock nut is formed.
　本発明によれば、ピストンとの軸ずれを許容しつつ、ロックナットとピストンの接触状態を維持しながら、構成部品に発生する曲げ変形を抑制することのできる電動ブレーキ装置を提供することができる。 According to the present invention, it is possible to provide an electric brake device capable of suppressing bending deformation generated in a component while maintaining a contact state between a lock nut and a piston while allowing shaft misalignment with the piston. ..
本発明の第１実施例に係る電動ブレーキ装置の断面図である。It is sectional drawing of the electric brake device which concerns on 1st Embodiment of this invention. 本発明の第１実施例に係るピストンとロックナットとスクリューシャフト部分の断面図である。It is sectional drawing of the piston, the lock nut, and the screw shaft portion which concerns on 1st Embodiment of this invention. 本発明の第１実施例に係る電動ブレーキ装置のキャリパー変形時の断面図である。It is sectional drawing at the time of caliper deformation of the electric brake device which concerns on 1st Embodiment of this invention. 本発明の第１実施例に係る電動ブレーキ装置のブレーキパッド摩耗時の断面図である。It is sectional drawing at the time of the brake pad wear of the electric brake device which concerns on 1st Embodiment of this invention. 本発明の第１実施例に係るピストンの軸ずれ、傾き発生時のピストンと回転直動変換機構部の断面図である。It is sectional drawing of the piston and the rotation linear motion conversion mechanism part at the time of the axis deviation and tilt occurrence of the piston which concerns on 1st Embodiment of this invention. 第１実施例の変形例に係るピストンとロックナットとスクリューシャフト部分の断面図である。It is sectional drawing of the piston, the lock nut, and the screw shaft part which concerns on the modification of 1st Example. 本発明の第２実施例に係るピストンとロックナットとスクリューシャフト部分の断面図である。It is sectional drawing of the piston, the lock nut, and the screw shaft portion which concerns on 2nd Embodiment of this invention. 図７のＡ－Ａ断面図である。FIG. 7 is a cross-sectional view taken along the line AA of FIG. 変形例に係る図７のＡ－Ａ断面図である。FIG. 7 is a cross-sectional view taken along the line AA of FIG. 7 according to a modified example. 本発明の第３実施例に係るピストンとロックナットとスクリューシャフト部分の断面図である。It is sectional drawing of the piston, the lock nut, and the screw shaft portion which concerns on 3rd Example of this invention. 図１０のＢ－Ｂ断面図である。FIG. 10 is a cross-sectional view taken along the line BB of FIG. 本発明の第４実施例に係るピストンとロックナットとスクリューシャフト部分の断面図である。It is sectional drawing of the piston, the lock nut, and the screw shaft portion which concerns on 4th Embodiment of this invention. 図１２のＣ－Ｃ断面図である。12 is a cross-sectional view taken along the line CC of FIG. 変形例に係る図１２のＣ－Ｃ断面図である。It is a CC sectional view of FIG. 12 which concerns on a modification. 本発明の第５実施例に係るピストンとロックナットとスクリューシャフト部分の断面図である。It is sectional drawing of the piston, the lock nut, and the screw shaft portion which concerns on 5th Embodiment of this invention. 図１５のＤ－Ｄ断面図である。FIG. 15 is a sectional view taken along line DD of FIG.
　以下、本発明の実施例について図を用いて説明する。 Hereinafter, examples of the present invention will be described with reference to the drawings.
　まず初めに電動ブレーキ装置の第１実施例について図１～図６を用いて説明する。図１は本発明の第１実施例に係る電動ブレーキ装置の断面図であり、図２は本発明の第１実施例に係るピストンとロックナットとスクリューシャフト部分の断面図である。 First, the first embodiment of the electric brake device will be described with reference to FIGS. 1 to 6. FIG. 1 is a cross-sectional view of an electric brake device according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view of a piston, a lock nut, and a screw shaft portion according to the first embodiment of the present invention.
　キャリパー１の内部には、シリンダ１０が形成されており、シリンダ１０内にピストン７が摺動可能に配置される。ピストン７は片側が開口した略円筒形状をしており、ロックナット６と螺合部２２で螺合されたスクリューシャフト５とが、ピストン７の内側に挿入されている。 A cylinder 10 is formed inside the caliper 1, and a piston 7 is slidably arranged in the cylinder 10. The piston 7 has a substantially cylindrical shape with one side open, and a lock nut 6 and a screw shaft 5 screwed by a screw portion 22 are inserted inside the piston 7.
　キャリパー１は、上方が閉塞し下方が開放され、開放した部分にブレーキパッドを収納している。ロックナット６は螺合筒部６ｂの中心軸が水平方向になるように配置されている。スクリューシャフト５は中心軸が水平方向になるように配置されている。 The upper part of the caliper 1 is closed and the lower part is opened, and the brake pad is stored in the opened part. The lock nut 6 is arranged so that the central axis of the screw cylinder portion 6b is in the horizontal direction. The screw shaft 5 is arranged so that the central axis is in the horizontal direction.
　電動モータ４を用いてブレーキを印加（アプライ）する場合、ＥＣＵ（エンジンコントロールユニット）は、電動モータ４を駆動させて減速機３に設置された各種ギアを回転させる。 When applying (applying) a brake using the electric motor 4, the ECU (engine control unit) drives the electric motor 4 to rotate various gears installed in the speed reducer 3.
　スクリューシャフト５は、キャリパー１にスラスト軸受１１を介して固定されており、電動モータ４の回転が減速機３を介してスクリューシャフト５に伝達される。スクリューシャフト５のアプライ方向への回転により、ロックナット６がピストン７の内面側（底部側）に向かって前進（移動）することで、ロックナット６とピストン７とが接触部２１において当接する。この当接により、ピストン７が前進し、ピストン７の外面側がブレーキパッド８に当接する。 The screw shaft 5 is fixed to the caliper 1 via a thrust bearing 11, and the rotation of the electric motor 4 is transmitted to the screw shaft 5 via the speed reducer 3. The rotation of the screw shaft 5 in the apply direction causes the lock nut 6 to move forward (move) toward the inner surface side (bottom side) of the piston 7, so that the lock nut 6 and the piston 7 come into contact with each other at the contact portion 21. By this contact, the piston 7 advances, and the outer surface side of the piston 7 comes into contact with the brake pad 8.
　接触部２１は、アプライ方向側がロックナット６の中心に向かうように傾斜している。
さらに電動モータ４のアプライ方向への回転駆動が継続されると、ピストン７は、ロックナット６の移動によりブレーキパッド８を押圧し、ディスクロータ９をキャリパー１の爪部１２側に配置したブレーキパッド８と挟むことによって、ブレーキ力である推力を発生させる。 The contact portion 21 is inclined so that the apply direction side faces the center of the lock nut 6.
Further, when the rotational drive of the electric motor 4 in the apply direction is continued, the piston 7 presses the brake pad 8 by the movement of the lock nut 6, and the disc rotor 9 is arranged on the claw portion 12 side of the caliper 1. By sandwiching it with 8, a thrust force, which is a braking force, is generated.
　図２に示すように、回転直動変換機構３０を構成するロックナット６は、ピストン７を押圧するための押圧部６ａと、スクリューシャフト５と螺合する螺合部２２を有する螺合筒部６ｂと、押圧部６ａと螺合筒部６ｂとの間に設けられる中間部６ｃより構成され、中間部６ｃには、ロックナット６の他の部位（押圧部６ａ，螺合筒部６ｂ）よりも剛性の小さい弾性変形部２３が形成されている。弾性変形部２３の剛性に関しては、特に曲げ剛性が小さいことが望ましい。 As shown in FIG. 2, the lock nut 6 constituting the rotation linear motion conversion mechanism 30 has a screw cylinder portion having a pressing portion 6a for pressing the piston 7 and a screw portion 22 screwing with the screw shaft 5. It is composed of 6b and an intermediate portion 6c provided between the pressing portion 6a and the screw cylinder portion 6b, and the intermediate portion 6c is formed from other parts of the lock nut 6 (pressing portion 6a, screw cylinder portion 6b). Also, an elastically deformed portion 23 having low rigidity is formed. Regarding the rigidity of the elastically deformed portion 23, it is particularly desirable that the bending rigidity is small.
　本実施例では、押圧部６ａは、螺合筒部６ｂより径方向の大きさが大きく形成された位置とする。螺合筒部６ｂは、ロックナット６におけるピストン７の開口側から螺合部２２の端部の位置までとする。中間部６ｃは螺合部２２の端部から径方向の大きさが変わる押圧部６ａに至る位置までとする。 In this embodiment, the pressing portion 6a is set to a position where the size in the radial direction is formed larger than that of the screw cylinder portion 6b. The screw cylinder portion 6b is from the opening side of the piston 7 in the lock nut 6 to the position of the end portion of the screw portion 22. The intermediate portion 6c is set to a position from the end portion of the screwed portion 22 to the pressing portion 6a whose size changes in the radial direction.
　次に、実施例１における作用効果について説明する。図３は、電動ブレーキ装置の推力が発生した時のキャリパー１の変形を示す断面図である。キャリパー１の爪部１２は、キャリパー１の一端側が固定された片持ち梁の状態であるため、ブレーキパッド８から伝達される推力がキャリパー１の爪部１２の内面に印加されることによって、図３の矢印１３の方向に曲げ変形を生じる。キャリパー１の爪部１２の曲げ変形が生じると、ピストン７は、その変形に追従しながら移動するため、軸ずれ、傾きを生じる。ピストン７に軸ずれ、傾きが発生する他の一要因を示す。 Next, the action and effect in Example 1 will be described. FIG. 3 is a cross-sectional view showing the deformation of the caliper 1 when the thrust of the electric brake device is generated. Since the claw portion 12 of the caliper 1 is in a state of a cantilever with one end side of the caliper 1 fixed, the thrust transmitted from the brake pad 8 is applied to the inner surface of the claw portion 12 of the caliper 1, which is shown in FIG. Bending deformation occurs in the direction of arrow 13 of 3. When the claw portion 12 of the caliper 1 is bent and deformed, the piston 7 moves while following the deformation, so that the piston 7 is displaced and tilted. Another factor that causes the piston 7 to be misaligned and tilted is shown.
　図４は電動ブレーキ装置のブレーキパッド摩耗時の断面図である。電動ブレーキ装置の経年劣化などによって、ブレーキパッド８に片摩耗１４が発生する。キャリパー１は図３の矢印１３の方向に曲げ変形を生じるので、ブレーキパッド８はキャリパー１の開放側から固定側（図４の下側から上側）に向かって隙間が徐々に広くなるように片摩耗する。ブレーキパッド８に片摩耗１４が発生すると、推力印加時にピストン７が片摩耗したブレーキパッド８を押し付けることになり、ブレーキパッド８の摩耗形状に追従して、ピストン７に軸ずれ、及び傾きが発生することが懸念される。ピストン７で生じた軸ずれ、傾きは、ピストン７の内面の接触部２１で接するロックナット６に伝達する。ロックナット６と、スクリューシャフト５との螺合部２２においては、ロックナット６から伝わる推力に起因した応力が発生するが、さらにピストン７の軸ずれ、偏心に起因した応力が新たに発生する。 FIG. 4 is a cross-sectional view of the electric brake device when the brake pads are worn. One-sided wear 14 occurs on the brake pad 8 due to aged deterioration of the electric brake device or the like. Since the caliper 1 is bent and deformed in the direction of the arrow 13 in FIG. 3, the brake pad 8 is pieced so that the gap gradually widens from the open side to the fixed side (from the lower side to the upper side in FIG. 4) of the caliper 1. Wear out. When one-sided wear 14 occurs on the brake pad 8, the piston 7 presses the one-sided worn brake pad 8 when thrust is applied, and the piston 7 is displaced and tilted following the wear shape of the brake pad 8. There is concern about doing so. The misalignment and inclination caused by the piston 7 are transmitted to the lock nut 6 which is in contact with the contact portion 21 on the inner surface of the piston 7. In the screwed portion 22 between the lock nut 6 and the screw shaft 5, stress is generated due to the thrust transmitted from the lock nut 6, but further stress due to the misalignment of the piston 7 and the eccentricity is newly generated.
　したがって、ロックナット６と、スクリューシャフト５との螺合部２２に発生する応力が増加することが懸念される。さらには、螺合部２２の接触状態が不均一となり、局所的に接触面圧が高くなることで、摩耗が促進されることや、ブレーキパッド８に印加する推力がばらつくことも懸念される。 Therefore, there is a concern that the stress generated in the screw portion 22 between the lock nut 6 and the screw shaft 5 will increase. Further, there is a concern that the contact state of the screwed portion 22 becomes non-uniform and the contact surface pressure locally increases, which accelerates wear and causes the thrust applied to the brake pad 8 to vary.
　これを解決するために、本実施例では、図２に示すように、ピストン７を押圧するための押圧部６ａとスクリューシャフト５と螺合する螺合筒部６ｂとの間（中間部６ｃ）に、ロックナット６の他の部位（押圧部６ａ，螺合筒部６ｂ）よりも剛性の小さい弾性変形部２３を形成している。 In order to solve this problem, in this embodiment, as shown in FIG. 2, between the pressing portion 6a for pressing the piston 7 and the screw cylinder portion 6b screwed with the screw shaft 5 (intermediate portion 6c). In addition, an elastically deformed portion 23 having a smaller rigidity than other portions (pressing portion 6a, screw cylinder portion 6b) of the lock nut 6 is formed.
　弾性変形部２３による効果について、図５を用いて説明する。図５は本発明の第１実施例に係るピストンの軸ずれ、傾き発生時のピストンと回転直動変換機構部の断面図である。 The effect of the elastically deformed portion 23 will be described with reference to FIG. FIG. 5 is a cross-sectional view of the piston and the rotational linear motion conversion mechanism portion when the piston is displaced or tilted according to the first embodiment of the present invention.
　本実施例では、上記のように構成することにより、ピストン７の軸ずれ、傾きが発生した場合、図５に示すように、ロックナット６の押圧部６ａにおける接触部２１で伝達した軸ずれ、傾きを弾性変形部２３によって吸収することができる。 In this embodiment, when the piston 7 is misaligned or tilted due to the above configuration, the misalignment transmitted by the contact portion 21 in the pressing portion 6a of the lock nut 6 is transmitted as shown in FIG. The inclination can be absorbed by the elastically deformed portion 23.
　したがって、本実施例によれば、弾性変形部２３より後端側にある螺合部２２への軸ずれ、傾きの影響を抑制することができ、螺合部２２の応力増加、推力ばらつきを抑制し、耐摩耗性も向上することができる。さらに、本実施例によれば、ロックナット６とピストン７の接触部２１においては、ピストン７の軸ずれ、傾きに追従するため、全面接触を維持できる。つまり、接触部２１の片当たりを防止し、耐摩耗性を向上することができる。
また、弾性変形部２３よりも後端側にあるスラスト軸受１１への片当たりを抑制し耐摩耗性を向上することも期待でき、高信頼な電動ブレーキ装置を提供できる。 Therefore, according to this embodiment, it is possible to suppress the influence of the axial deviation and the inclination of the screwed portion 22 on the rear end side of the elastically deformed portion 23, and suppress the stress increase and the thrust variation of the screwed portion 22. However, the wear resistance can be improved. Further, according to the present embodiment, the contact portion 21 between the lock nut 6 and the piston 7 follows the axial deviation and inclination of the piston 7, so that the entire contact can be maintained. That is, it is possible to prevent the contact portion 21 from hitting one side and improve the wear resistance.
Further, it can be expected that one-sided contact with the thrust bearing 11 located on the rear end side of the elastically deformed portion 23 is suppressed to improve wear resistance, and a highly reliable electric braking device can be provided.
　ロックナット６の弾性変形部２３の形成方法としては、例えば、ロックナット６と材質が異なり剛性の小さい別部材を異種界面接合や接着などによって挟み込むようにして形成することで実現できる。 The method of forming the elastically deformed portion 23 of the lock nut 6 can be realized, for example, by forming another member having a material different from that of the lock nut 6 and having a low rigidity by sandwiching it by interfacial bonding or adhesion.
　図６に変形例を示す。図６は第１実施例の変形例に係るピストンとロックナットとスクリューシャフト部分の断面図である。 FIG. 6 shows a modified example. FIG. 6 is a cross-sectional view of a piston, a lock nut, and a screw shaft portion according to a modified example of the first embodiment.
　変形性では、押圧部６ａと螺合筒部６ｂとの間に形成される中間部６ｃの長さを図２に比べて長く形成している。そして、変形例では中間部６ｃに形成する弾性変形部２３の位置を図２に比べ、螺合筒部６ｂ側に寄せて配置している。弾性変形部２３の形成箇所については、接触部２１と螺合部２２の間であれば同様の効果を奏することは言うまでもない。 In terms of deformability, the length of the intermediate portion 6c formed between the pressing portion 6a and the screw cylinder portion 6b is formed longer than that in FIG. Then, in the modified example, the position of the elastically deformed portion 23 formed in the intermediate portion 6c is arranged closer to the screwed cylinder portion 6b side as compared with FIG. It goes without saying that the same effect can be obtained with respect to the formed portion of the elastically deformed portion 23 if it is between the contact portion 21 and the screwed portion 22.
　次に、本発明の第２実施例について図７～９を用いて説明する。第１実施例と同様の構成については説明を省略する。図７は本発明の第２実施例に係るピストンとロックナットとスクリューシャフト部分の断面図である。図８は、図７のＡ－Ａ断面図である。図９は変形例に係る図７のＡ－Ａ断面図である。 Next, the second embodiment of the present invention will be described with reference to FIGS. 7 to 9. The description of the same configuration as that of the first embodiment will be omitted. FIG. 7 is a cross-sectional view of a piston, a lock nut, and a screw shaft portion according to a second embodiment of the present invention. FIG. 8 is a cross-sectional view taken along the line AA of FIG. FIG. 9 is a cross-sectional view taken along the line AA of FIG. 7 according to a modified example.
　第１実施例と異なるところは、ロックナット６の弾性変形部２３として、ロックナット６の他の部分の板厚よりも薄い薄肉部２４を形成した点にある。押圧部６ａと螺合筒部６ｂとの間の中間部６ｃには、押圧部６ａ及び螺合筒部６ｂの板厚より薄い薄肉部２４が形成されている。薄肉部２４は、キャリパー１のブレーキパッド８やディスクロータ９を格納している開口部側(図７，図８の下側)とその対向側(図７，図８の上側)に形成している。薄肉部２４は、例えばロックナット外周の一部を切削加工することで形成できる。 The difference from the first embodiment is that as the elastically deformed portion 23 of the lock nut 6, a thin portion 24 thinner than the plate thickness of the other portion of the lock nut 6 is formed. An intermediate portion 6c between the pressing portion 6a and the screw cylinder portion 6b is formed with a thin portion 24 thinner than the plate thickness of the pressing portion 6a and the screw cylinder portion 6b. The thin portion 24 is formed on the opening side (lower side in FIGS. 7 and 8) and the opposite side (upper side in FIGS. 7 and 8) in which the brake pad 8 and the disc rotor 9 of the caliper 1 are stored. There is. The thin-walled portion 24 can be formed, for example, by cutting a part of the outer circumference of the lock nut.
　本実施例では、薄肉部２４は、ロックナット６の外周面の上方及び下方を切欠いて形成している。そして、薄肉部２４は、ロックナット６の中間部６ｃの外周径よりも径が小さい小径部を備える。ブレーキパッド８の片摩耗によるピストン７に軸ずれ、傾きは、キャリパー１の開口部側(図７，図８の下側)とその対向側(図７，図８の上側)に発生するので、薄肉部２４は少なくともロックナット外周の上下に形成すると良い。 In this embodiment, the thin portion 24 is formed by notching the upper side and the lower side of the outer peripheral surface of the lock nut 6. The thin portion 24 includes a small diameter portion having a diameter smaller than the outer peripheral diameter of the intermediate portion 6c of the lock nut 6. Since the piston 7 is misaligned and tilted due to one-sided wear of the brake pad 8, it occurs on the opening side (lower side of FIGS. 7 and 8) and the opposite side (upper side of FIGS. 7 and 8) of the caliper 1. The thin portion 24 may be formed at least above and below the outer circumference of the lock nut.
　本実施例によれば、ロックナットを例えば鍛造などによって一体部材として形成することができるため、加工精度ばらつきや組み立てばらつきによるロックナットの軸ずれを低減できる。さらに、薄肉部２４は切削という容易な方法で形成でき、加工性の向上も期待できる。これにより、さらに高信頼な電動ブレーキ装置を提供できる。 According to this embodiment, since the lock nut can be formed as an integral member by, for example, forging, it is possible to reduce the shaft deviation of the lock nut due to variations in processing accuracy and assembly. Further, the thin portion 24 can be formed by an easy method of cutting, and improvement in workability can be expected. This makes it possible to provide a more highly reliable electric brake device.
　なお、図９に示すように、薄肉部２４はロックナット６の外周の全周に亘って形成するようにしても良い。薄肉部２４の形成にあたっては、ロックナット６の外周の全周を切削加工によって切削し、ロックナット６を小径化する。 As shown in FIG. 9, the thin portion 24 may be formed over the entire circumference of the outer circumference of the lock nut 6. In forming the thin portion 24, the entire circumference of the outer circumference of the lock nut 6 is cut by cutting to reduce the diameter of the lock nut 6.
　次に、本発明の第３実施例について図１０及び図１１を用いて説明する。第１実施例、及び第２実施例と同様の構成については説明を省略する。図１０は本発明の第３実施例に係るピストンとロックナットとスクリューシャフト部分の断面図である。図１１は、図１０のＢ－Ｂ断面図である。 Next, a third embodiment of the present invention will be described with reference to FIGS. 10 and 11. The description of the same configurations as those of the first embodiment and the second embodiment will be omitted. FIG. 10 is a cross-sectional view of a piston, a lock nut, and a screw shaft portion according to a third embodiment of the present invention. FIG. 11 is a cross-sectional view taken along the line BB of FIG.
　第１実施例と異なるところは、ロックナット６の弾性変形部２３としての薄肉部２４を、円筒の内周側を切削して形成した点にある。 The difference from the first embodiment is that the thin-walled portion 24 as the elastically deformed portion 23 of the lock nut 6 is formed by cutting the inner peripheral side of the cylinder.
　押圧部６ａと螺合筒部６ｂとの間の中間部６ｃには、押圧部６ａ及び螺合筒部６ｂの板厚より薄い薄肉部２４が形成されている。薄肉部２４は、ロックナット６の内周側に形成している。薄肉部２４は、例えばロックナット内周の全周を切削加工することで形成できる。ロックナット内周の全周を切削加工することにより、ロックナット６の内周は大径化される。薄肉部２４は、ロックナット６の中間部６ｃの内周径よりも径が大きい大径部を備える。 In the intermediate portion 6c between the pressing portion 6a and the screw cylinder portion 6b, a thin portion 24 thinner than the plate thickness of the pressing portion 6a and the screw cylinder portion 6b is formed. The thin portion 24 is formed on the inner peripheral side of the lock nut 6. The thin-walled portion 24 can be formed, for example, by cutting the entire inner circumference of the lock nut. By cutting the entire inner circumference of the lock nut 6, the inner circumference of the lock nut 6 is increased in diameter. The thin portion 24 includes a large diameter portion having a diameter larger than the inner peripheral diameter of the intermediate portion 6c of the lock nut 6.
　図４に示すブレーキパッド８の片摩耗の方向は制御することが困難であり、ピストン７の軸ずれ、傾きの方向も様々となる。本実施例によれば、ロックナット６の弾性変形部２３は円筒の内周側を切削した薄肉することで構成しており、どの方向に対しても曲げ剛性が小さいため、ピストン７の軸ずれ、傾きの影響を弾性変形部２３によって吸収することができる。これにより、ロックナット６とスクリューシャフト５の螺合部２２の応力増加やスラスト軸受１１の片当たりを防止することができる。 It is difficult to control the direction of one-sided wear of the brake pad 8 shown in FIG. 4, and the directions of axial deviation and inclination of the piston 7 also vary. According to this embodiment, the elastically deformed portion 23 of the lock nut 6 is formed by cutting the inner peripheral side of the cylinder to make it thinner, and the bending rigidity is small in any direction, so that the piston 7 is displaced. , The influence of inclination can be absorbed by the elastically deformed portion 23. As a result, it is possible to prevent the stress increase of the screwed portion 22 of the lock nut 6 and the screw shaft 5 and the one-sided contact of the thrust bearing 11.
　次に、本発明の第４実施例について図１２～１４を用いて説明する。第１実施例～第３実施例と同様の構成については説明を省略する。図１２は本発明の第４実施例に係るピストンとロックナットとスクリューシャフト部分の断面図である。図１３は図１２のＣ－Ｃ断面図である。図１４は変形例に係る図１２のＣ－Ｃ断面図である。 Next, the fourth embodiment of the present invention will be described with reference to FIGS. 12 to 14. The description of the same configurations as those of the first to third embodiments will be omitted. FIG. 12 is a cross-sectional view of a piston, a lock nut, and a screw shaft portion according to a fourth embodiment of the present invention. FIG. 13 is a cross-sectional view taken along the line CC of FIG. FIG. 14 is a cross-sectional view taken along the line CC of FIG. 12 according to a modified example.
　第１実施例～第３実施例と異なるところは、ロックナット６の弾性変形部２３を貫通孔２５によって形成した点にある。 The difference from the first to third embodiments is that the elastically deformed portion 23 of the lock nut 6 is formed by the through hole 25.
　押圧部６ａと螺合筒部６ｂとの間の中間部６ｃには、ロックナット６の外周から内周を貫通した貫通孔２５が形成されている。貫通孔２５はドリル加工などにより任意の位置に形成する。貫通孔２５が形成された部分は中空となるので、他の部分より剛性が低くなり、弾性変形し易くなる。そのため、貫通孔２５の数、穴径を調整することにより任意の曲げ剛性となるように弾性変形部２３を容易に構成することが可能となる。本実施例では、図１３に示すように、ロックナット６を中心軸方向から見て、弾性変形部２３としての貫通孔２５を上下左右に複数形成している。 A through hole 25 is formed in the intermediate portion 6c between the pressing portion 6a and the screw cylinder portion 6b so as to penetrate the inner circumference from the outer circumference of the lock nut 6. The through hole 25 is formed at an arbitrary position by drilling or the like. Since the portion where the through hole 25 is formed is hollow, the rigidity is lower than that of the other portions, and the portion is easily elastically deformed. Therefore, by adjusting the number of through holes 25 and the hole diameter, it is possible to easily configure the elastically deformed portion 23 so as to have an arbitrary bending rigidity. In this embodiment, as shown in FIG. 13, a plurality of through holes 25 as elastically deformed portions 23 are formed vertically and horizontally when the lock nut 6 is viewed from the central axis direction.
　本実施例によれば、ロックナット６に弾性変形部２３としての貫通孔２５を形成しているので、ピストン７の軸ずれ、傾きの影響を弾性変形部２３としての貫通孔２５で吸収することができる。 According to this embodiment, since the lock nut 6 is formed with a through hole 25 as the elastically deformed portion 23, the influence of the axial deviation and inclination of the piston 7 is absorbed by the through hole 25 as the elastically deformed portion 23. Can be done.
　また、貫通孔２５は図１４に示すように周方向に不均一に形成するようにしても良い。
例えば、上下に形成した貫通孔２５の数を、左右に形成した貫通孔２５の数よりも多くする。貫通孔２５の数を異ならせることにより、弾性変形部２３における曲げ剛性を周方向で変化させることができる。ブレーキパッド８の片摩耗によるピストン７に軸ずれ、傾きは、キャリパー１の開口部側(図１２，図１４の下側)とその対向側(図１２，図１４の上側)に発生するので、上下に形成した貫通孔２５の数を、左右に形成した貫通孔２５の数よりも多く形成すると良い。また、貫通孔２５の数を変化させる以外に、穴径を変化させるようにしても良い。 Further, the through hole 25 may be formed non-uniformly in the circumferential direction as shown in FIG.
For example, the number of through holes 25 formed at the top and bottom is made larger than the number of through holes 25 formed at the left and right. By changing the number of through holes 25, the flexural rigidity of the elastically deformed portion 23 can be changed in the circumferential direction. Since the piston 7 is misaligned and tilted due to one-sided wear of the brake pad 8, it occurs on the opening side (lower side of FIGS. 12 and 14) of the caliper 1 and the opposite side (upper side of FIGS. 12 and 14). It is preferable that the number of through holes 25 formed at the top and bottom is larger than the number of through holes 25 formed at the left and right. In addition to changing the number of through holes 25, the hole diameter may be changed.
　ピストン７の軸ずれ、傾きが大きい方向については、貫通孔２５の数、穴径を大きくすることでピストン７の軸ずれ、傾きの影響を吸収しやすくし、ピストン７の軸ずれ、傾きが小さい方向については、貫通孔２５の数、穴径を小さくし、ロックナット６の剛性が過度に小さくなることを抑制することができる。 In the direction where the axis deviation and inclination of the piston 7 are large, the influence of the axis deviation and inclination of the piston 7 can be easily absorbed by increasing the number of through holes 25 and the hole diameter, and the axis deviation and inclination of the piston 7 are small. Regarding the direction, the number of through holes 25 and the hole diameter can be reduced to prevent the lock nut 6 from becoming excessively rigid.
　本実施例によれば、弾性変形部２３の剛性の最適化が可能となり、より高信頼な電動ブレーキ装置を提供することができる。 According to this embodiment, it is possible to optimize the rigidity of the elastically deformed portion 23, and it is possible to provide a more reliable electric brake device.
　次に、本発明の第５実施例について図１５及び図１６を用いて説明する。先の実施例と同様の構成については説明を省略する。図１５は本発明の第５実施例に係るピストンとロックナットとスクリューシャフト部分の断面図である。図１６は図１５のＤ－Ｄ断面図である。 Next, a fifth embodiment of the present invention will be described with reference to FIGS. 15 and 16. The description of the same configuration as that of the previous embodiment will be omitted. FIG. 15 is a cross-sectional view of a piston, a lock nut, and a screw shaft portion according to a fifth embodiment of the present invention. 16 is a cross-sectional view taken along the line DD of FIG.
　第１実施例～第４実施例と異なるところは、ロックナット６の押圧部６ａの外周に、ロックナット６の回転を抑制する回転止め部３１を形成した点にある。回転止め部３１は、ロックナット６がピストン７と接触する接触部２１と、中間部６ｃ（弾性変形部２３）との間に形成されており、ピストン７の内周に形成された平端部と接している。 The difference from the first to fourth embodiments is that a rotation stop portion 31 for suppressing the rotation of the lock nut 6 is formed on the outer circumference of the pressing portion 6a of the lock nut 6. The rotation stop portion 31 is formed between the contact portion 21 in which the lock nut 6 contacts the piston 7 and the intermediate portion 6c (elastic deformation portion 23), and has a flat end portion formed on the inner circumference of the piston 7. I'm in contact.
　ロックナット６をピストン７に対して並進摺動させるためには、ロックナット６をピストン７に対して回転拘束する必要がある。ロックナット６に回転止め部３１を形成し、回転止め部３１とピストン７を接触させることで回転拘束を実現する。このとき、ピストン７の軸ずれ、傾きが生じると、ピストン７とロックナット６の接触部２１に加えて回転止め部３１によって、軸ずれ、傾きを伝達する。つまり、回転止め部３１によって、ピストン７とロックナット６の接触部２１の接触を均一に保持する働きが作用するため、接触部２１の片当たり抑制効果が期待できる。また、本実施例構成では、ロックナット６の弾性変形部２３が、回転止め部３１とスクリューシャフト５との螺合部２２との間に形成している。そのため、本実施例によれば、先の実施例と同様に、ロックナット６に伝達した軸ずれ、傾きを弾性変形部２３で吸収することができる。 In order to slide the lock nut 6 in translation with respect to the piston 7, it is necessary to restrain the lock nut 6 from rotating with respect to the piston 7. A rotation stop portion 31 is formed on the lock nut 6, and the rotation stop portion 31 and the piston 7 are brought into contact with each other to realize rotation restraint. At this time, if the piston 7 is misaligned or tilted, the misalignment or tilt is transmitted by the rotation stopper 31 in addition to the contact portion 21 between the piston 7 and the lock nut 6. That is, since the rotation stop portion 31 acts to uniformly maintain the contact between the contact portion 21 of the piston 7 and the lock nut 6, an effect of suppressing one-sided contact of the contact portion 21 can be expected. Further, in the configuration of the present embodiment, the elastically deformed portion 23 of the lock nut 6 is formed between the rotation stop portion 31 and the screwed portion 22 of the screw shaft 5. Therefore, according to the present embodiment, the elastic deformation portion 23 can absorb the axial deviation and the inclination transmitted to the lock nut 6 as in the previous embodiment.
　以上説明したように、本発明の各実施例によれば、ピストンとの軸ずれを許容しつつ、ロックナットとピストンの接触状態を維持しながら、構成部品に発生する曲げ変形を抑制することのできる電動ブレーキ装置を提供することができる。 As described above, according to each embodiment of the present invention, it is possible to suppress the bending deformation that occurs in the component parts while maintaining the contact state between the lock nut and the piston while allowing the shaft deviation from the piston. An electric braking device capable of being provided can be provided.
　尚、本発明は、上述した実施例に限定するものではなく、様々な変形例が含まれる。例えば、上述した実施例は本発明を分かり易く説明するために詳細に説明したものであり、必ずしも説明した全ての構成を備えるものに限定するものではない。またある実施例の構成の一部を他の実施例の構成に置き換えることが可能であり、また、ある実施例の構成に他の実施例の構成を加えることも可能である。また、各実施例の構成の一部について、他の構成の追加、削除、置換をすることが可能である。 The present invention is not limited to the above-mentioned examples, and includes various modifications. For example, the above-described examples have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the described configurations. It is also possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. In addition, it is possible to add, delete, or replace a part of the configuration of each embodiment with another configuration.
　１…キャリパー、２…ケーシング、３…減速機、４…電動モータ、５…スクリューシャフト、６…ロックナット、６ａ…押圧部、６ｂ…螺合筒部、６ｃ…中間部、７…ピストン、８…ブレーキパッド、９…ディスクロータ、１０…シリンダ、１１…スラスト軸受、１２…キャリパーの爪部、１４…片摩耗、２１…接触部、２２…螺合部、２３…弾性変形部、２４…薄肉部、２５…貫通孔、３０…回転直動変換機構、３１…回転止め部 1 ... Caliper, 2 ... Casing, 3 ... Reducer, 4 ... Electric motor, 5 ... Screw shaft, 6 ... Lock nut, 6a ... Pressing part, 6b ... Screw cylinder part, 6c ... Intermediate part, 7 ... Piston, 8 ... Brake pad, 9 ... Disc rotor, 10 ... Cylinder, 11 ... Thrust bearing, 12 ... Caliper claw part, 14 ... One-sided wear, 21 ... Contact part, 22 ... Screw part, 23 ... Elastic deformation part, 24 ... Thin wall Part, 25 ... Through hole, 30 ... Rotational linear motion conversion mechanism, 31 ... Rotation stop part

Claims (10)

  1. 　ブレーキパッドと当接するピストンと、電動モータの回転を伝達するスクリューシャフトと、前記ピストンの内側に備えられ、前記スクリューシャフトの回転により移動して前記ピストンを押圧するロックナットとを備えた電動ブレーキ装置であって、
    　前記ロックナットは、前記ピストンを押圧する押圧部と、前記スクリューシャフトと螺合する螺合筒部と、前記押圧部と前記螺合筒部との間に位置する中間部とを有し、
    　前記中間部には、前記ロックナットの他の部分よりも剛性が小さい弾性変形部を形成したことを特徴とする電動ブレーキ装置。     An electric brake device including a piston that comes into contact with a brake pad, a screw shaft that transmits the rotation of an electric motor, and a lock nut that is provided inside the piston and moves by the rotation of the screw shaft to press the piston. And
    The lock nut has a pressing portion that presses the piston, a screw cylinder portion that is screwed with the screw shaft, and an intermediate portion that is located between the pressing portion and the screw cylinder portion.
    An electric brake device characterized in that an elastically deformed portion having a rigidity smaller than that of the other portion of the lock nut is formed in the intermediate portion.
  2. 　請求項１において、
    　前記弾性変形部は、前記ロックナットの他の部分の板厚よりも薄い薄肉部により形成したことを特徴とする電動ブレーキ装置。     In claim 1,
    An electric brake device characterized in that the elastically deformed portion is formed of a thin portion thinner than the plate thickness of the other portion of the lock nut.
  3. 　請求項２において、
    　前記薄肉部は、前記ロックナットの前記中間部の外周径よりも径が小さい小径部を備えることを特徴とする電動ブレーキ装置。     In claim 2,
    The thin-walled portion is an electric brake device including a small diameter portion having a diameter smaller than the outer peripheral diameter of the intermediate portion of the lock nut.
  4. 　請求項２において、
    　前記薄肉部は、前記ロックナットの前記中間部の内周径よりも径が大きい大径部を備えることを特徴とする電動ブレーキ装置。     In claim 2,
    The thin-walled portion is an electric brake device including a large-diameter portion having a diameter larger than the inner peripheral diameter of the intermediate portion of the lock nut.
  5. 　請求項２において、
    　上方が閉塞し下方が開放され前記ブレーキパッドを収納するキャリパーを備え、
    　前記ロックナットは前記螺合筒部の中心軸が水平方向になるように配置され、
    　前記薄肉部は、前記ロックナットの外周面の上方及び下方を切欠いて形成したことを特徴とする電動ブレーキ装置。     In claim 2,
    It is equipped with a caliper that closes the upper part and opens the lower part to store the brake pads.
    The lock nut is arranged so that the central axis of the screw cylinder portion is in the horizontal direction.
    The thin-walled portion is an electric brake device formed by notching above and below the outer peripheral surface of the lock nut.
  6. 　請求項１において、
    　前記弾性変形部は、前記ロックナットの外周から内周を貫通した貫通孔により形成したことを特徴とする電動ブレーキ装置。     In claim 1,
    An electric brake device characterized in that the elastically deformed portion is formed by a through hole penetrating the inner circumference from the outer circumference of the lock nut.
  7. 　請求項６において、
    　前記ロックナットは前記螺合筒部の中心軸が水平方向になるように配置され、
    　前記貫通孔は前記ロックナットを中心軸方向から見て、前記ロックナットの上下左右に複数形成したことを特徴とする電動ブレーキ装置。     In claim 6,
    The lock nut is arranged so that the central axis of the screw cylinder portion is in the horizontal direction.
    An electric brake device characterized in that a plurality of the through holes are formed in the vertical and horizontal directions of the lock nut when the lock nut is viewed from the central axis direction.
  8. 　請求項１乃至７の何れか１項において、
    　前記ロックナットの前記ピストンに対する回転を抑制する回転止め部を備えたことを特徴とする電動ブレーキ装置。     In any one of claims 1 to 7,
    An electric brake device including a rotation stopper that suppresses rotation of the lock nut with respect to the piston.
  9. 　請求項８において、
    　前記回転止め部は、前記押圧部の外周に形成したことを特徴とする電動ブレーキ装置。     In claim 8.
    The rotation stop portion is an electric brake device formed on the outer periphery of the pressing portion.
  10. 　請求項８において、
    　前記回転止め部は、前記ロックナットが前記ピストンと接触する接触部と、前記中間部との間に形成したことを特徴とする電動ブレーキ装置。     In claim 8.
    The rotation stop portion is an electric brake device characterized in that the lock nut is formed between a contact portion in contact with the piston and the intermediate portion.
PCT/JP2020/022515 2019-07-04 2020-06-08 Electric brake device WO2021002150A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015044424A (en) * 2013-08-27 2015-03-12 株式会社アドヴィックス Drive device for electric parking brake, and electric parking brake device
WO2018003393A1 (en) * 2016-06-28 2018-01-04 日立オートモティブシステムズ株式会社 Disc brake
JP2019060399A (en) * 2017-09-26 2019-04-18 日立オートモティブシステムズ株式会社 Disc brake

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5699953B2 (en) 2012-02-02 2015-04-15 トヨタ自動車株式会社 Electric parking brake device

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015044424A (en) * 2013-08-27 2015-03-12 株式会社アドヴィックス Drive device for electric parking brake, and electric parking brake device
WO2018003393A1 (en) * 2016-06-28 2018-01-04 日立オートモティブシステムズ株式会社 Disc brake
JP2019060399A (en) * 2017-09-26 2019-04-18 日立オートモティブシステムズ株式会社 Disc brake

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