WO2016035610A1 - Load sensor, electric linear actuator, and electric brake apparatus - Google Patents

Load sensor, electric linear actuator, and electric brake apparatus Download PDF

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Publication number
WO2016035610A1
WO2016035610A1 PCT/JP2015/073844 JP2015073844W WO2016035610A1 WO 2016035610 A1 WO2016035610 A1 WO 2016035610A1 JP 2015073844 W JP2015073844 W JP 2015073844W WO 2016035610 A1 WO2016035610 A1 WO 2016035610A1
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WIPO (PCT)
Prior art keywords
load
detection unit
axial
elastic member
load detection
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PCT/JP2015/073844
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French (fr)
Japanese (ja)
Inventor
山崎　達也
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Ntn株式会社
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Publication of WO2016035610A1 publication Critical patent/WO2016035610A1/en

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    • 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
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C41/00—Other accessories, e.g. devices integrated in the bearing not relating to the bearing function as such
    • 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
    • F16D55/00—Brakes with substantially-radial braking surfaces pressed together in axial direction, e.g. disc brakes
    • F16D55/24—Brakes with substantially-radial braking surfaces pressed together in axial direction, e.g. disc brakes with a plurality of axially-movable discs, lamellae, or pads, pressed from one side towards an axially-located member
    • F16D55/26—Brakes with substantially-radial braking surfaces pressed together in axial direction, e.g. disc brakes with a plurality of axially-movable discs, lamellae, or pads, pressed from one side towards an axially-located member without self-tightening action
    • F16D55/28—Brakes with only one rotating disc
    • 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
    • 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
    • F16D66/00—Arrangements for monitoring working conditions, e.g. wear, temperature
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L1/00—Measuring force or stress, in general
    • G01L1/04—Measuring force or stress, in general by measuring elastic deformation of gauges, e.g. of springs
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L5/00—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
    • G01L5/12—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes for measuring axial thrust in a rotary shaft, e.g. of propulsion plants

Definitions

  • the present invention relates to a load sensor, an electric linear actuator using the load sensor, and an electric brake device.
  • An electric brake device generally converts the rotation of an electric motor into axial movement of a linear motion member, and presses the friction pad forward in the axial direction with the linear motion member to generate a braking force.
  • electric brake devices In order to control this braking force to a desired magnitude, electric brake devices often incorporate a load sensor in a portion that receives a reaction force of an axial load applied to a friction pad. Based on the output of the load sensor, the electric motor is controlled so that an appropriate braking force corresponding to the driver's pedal operation and the state of the vehicle is generated.
  • Each of the load sensors described in Patent Documents 1 to 3 has an elastic member that undergoes elastic deformation when an axial load is input from the outside, and a single magnetic sensor unit that outputs a signal corresponding to the deformation amount of the elastic member And the magnitude of the axial load is calculated based on the output of the magnetic sensor unit.
  • the problem to be solved by the present invention is to provide a load sensor suitable for a vehicle brake device.
  • the present invention provides a load sensor having the following configuration.
  • An elastic member that receives an axial load from the outside and causes elastic deformation;
  • Two or more load detection units that output a signal corresponding to the deformation amount of the elastic member,
  • the two or more load detection units are: A first load detection unit that outputs a signal corresponding to a deformation amount of the elastic member in a first load region in which a magnitude of an axial load input to the elastic member is smaller than a predetermined upper limit;
  • a second load region that includes an axial load that is greater than the upper limit value of the first load region, and a second load detector that outputs a signal corresponding to the amount of deformation of the elastic member,
  • the first load detection unit and the second load detection unit are load sensors configured such that the first load detection unit has a higher detection resolution than the second load detection unit.
  • the load in the first load region where the magnitude of the axial load is small, the load can be detected by the first load detection unit having high detection resolution. Therefore, when this load sensor is used in a vehicle brake device, it is possible to obtain a load detection resolution sufficient to cope with a driver's fine pedal operation during normal braking with a relatively small deceleration. On the other hand, during sudden braking with relatively large deceleration, the second load detection unit can detect an axial load that is larger than the upper limit value of the first load region.
  • the second load area is set so as to at least partially overlap the first load area.
  • the axial load can be detected in a continuous load region that extends over the upper limit value of the first load region.
  • the first load region is a region where the magnitude of the axial load input to the elastic member is from zero to the upper limit value
  • the second load region is preferably a region in which the magnitude of the axial load input to the elastic member is from zero to an upper limit value that is twice or more the upper limit value.
  • the axial load can be detected by both the first load detection unit and the second load detection unit. Therefore, even when one of the first load detection unit and the second load detection unit fails, the other load detection unit can detect the axial load in the first load region. Excellent redundancy can be obtained.
  • the two or more load detection units are arranged at equal intervals in the circumferential direction around the center of action of the axial load on the elastic member.
  • the respective signals output from the first load detection unit and the second load detection unit are input, and the load value and the second load detection in the first load detection unit based on the respective signals.
  • the load value at the first portion is calculated, and in the first load region, the average of the load value at the first load detection portion and the load value at the second load detection portion is the axial direction. It is preferable to provide a control unit that outputs the magnitude of the load.
  • the first load detection unit a unit composed of a magnetic target that generates a magnetic field and a magnetic sensor unit arranged so that a relative position with respect to the magnetic target changes according to a deformation amount of the elastic member is adopted.
  • the magnetic target two permanent magnets magnetized in a direction orthogonal to the relative displacement direction of the magnetic target and the magnetic sensor unit due to the deformation of the elastic member are the N pole of one permanent magnet and the other permanent magnet. Adopting the S pole so as to be adjacent in the relative displacement direction of the magnetic target and the magnetic sensor unit, It is preferable that the magnetic sensor unit is disposed in the vicinity of the boundary between the adjacent north and south poles.
  • the output signal of the magnetic sensor unit changes sharply according to the minute relative movement between the magnetic target and the magnetic sensor unit, and as a result, high detection resolution can be realized.
  • the output signal of the magnetic sensor unit changes sharply with respect to the relative displacement between the magnetic target and the magnetic sensor unit due to the deformation of the elastic member. Since directivity that does not change much occurs, the output signal of the magnetic sensor unit is not easily influenced by external vibration, and the magnitude of the load can be detected with stable accuracy.
  • the thing of the following structures is provided as an electrically driven linear motion actuator using the said load sensor.
  • an electric linear actuator having an electric motor and a motion conversion mechanism that converts rotation of the electric motor into axial movement of the linear member
  • An electric linear motion actuator wherein the load sensor is incorporated in a portion that receives a reaction force in the axial rearward direction that acts on the linear motion member when the object is pressed forward in the axial direction by the linear motion member.
  • the motion conversion mechanism includes a rotating shaft to which rotation of the electric motor is input, a plurality of planetary rollers that are in rolling contact with the outer diameter surface of the rotating shaft, and a plurality of planetary rollers that can rotate and revolve.
  • a carrier to be engaged an outer ring member as the linear motion member disposed so as to surround the plurality of planetary rollers, a spiral ridge provided on an inner diameter surface of the outer ring member, and the spiral ridge to be engaged with the outer ring member.
  • the elastic member can be a member that restricts the movement of the carrier in the axially rearward direction by supporting the carrier via a thrust bearing.
  • an electric brake device which uses the said load sensor.
  • An electric brake having an electric motor and a motion conversion mechanism for converting rotation of the electric motor into axial movement of the linear motion member, and generating a braking force by pressing the friction pad forward in the axial direction by the linear motion member
  • the load sensor is incorporated in a portion that receives a reaction force in the axial rearward direction that acts on the linear motion member when the friction pad is pressed forward in the axial direction by the linear motion member.
  • the first load detection unit having high detection resolution detects the load. Therefore, when this load sensor is used in a vehicle brake device, it is possible to obtain a load detection resolution sufficient to cope with a driver's fine pedal operation during normal braking with a relatively small deceleration.
  • the second load detection unit can detect an axial load that is larger than the upper limit value of the first load region. Therefore, the load sensor of the present invention is suitable for a vehicle brake device.
  • Sectional drawing which shows the load sensor of embodiment of this invention
  • the load sensor shown in FIG. 1 is viewed from the front side in the axial direction.
  • the expanded sectional view of the vicinity of the 1st load detection part of the load sensor shown in FIG. The figure which shows the correspondence of the magnitude
  • Block diagram of a control unit that calculates the magnitude of the axial load based on the output signal of the magnetic sensor unit of each load detection unit The figure which shows the correspondence of the output signal of a magnetic sensor part of each load detection part, and a load value
  • FIG. 3 is an enlarged sectional view showing an example in which the arrangement of the magnetic target and the magnetic sensor unit shown in FIG.
  • Sectional drawing which shows the electric brake device for vehicles using the load sensor shown in FIG. Fig. 11 is an enlarged cross-sectional view of the vicinity of the linear actuator Sectional view along line XIII-XIII in FIG. Sectional drawing which shows the electric brake device which employ
  • Sectional drawing which shows the electric brake device which employ
  • Sectional view along line XVI-XVI in FIG. 16A is a view showing the relationship between the ball and the inclined groove shown in FIG. 16, and
  • FIG. 16B is a view showing a state in which the rotation disk and the linear motion disk are relatively rotated from the state shown in FIG. Figure
  • the load sensor 1 includes an elastic member 2 that generates elastic deformation when a load is input from the front in the axial direction, a stationary member 3 that supports the elastic member 2 from the rear in the axial direction, and a signal corresponding to the deformation amount of the elastic member 2. It has the 1st load detection part 4a and the 2nd load detection part 4b which output.
  • the elastic member 2 is a ring-shaped member formed of a metal such as iron.
  • a load input portion 5 for inputting an axial load is provided on the front surface in the axial direction of the elastic member 2.
  • the load input portion 5 is a rolling surface of a rolling element of a thrust bearing 43 (see FIG. 12) described later.
  • a supported portion 6 supported by the stationary member 3 is provided on the rear surface in the axial direction of the elastic member 2.
  • the stationary member 3 is made of metal, and the metal is preferably a magnetic material.
  • the stationary member 3 includes an annular support portion 7 that supports the supported portion 6 of the elastic member 2 from the rear in the axial direction, and a fitting formed on the outer diameter side of the support portion 7 so as to be fitted to the outer periphery of the elastic member 2.
  • a combination tube portion 8, a cylindrical portion 9 provided so as to face the inner diameter side of the elastic member 2, and a connecting portion 10 that connects the cylindrical portion 9 and the support portion 7 in the axially rearward direction of the elastic member 2. Have.
  • a tightening margin is set between the inner periphery of the fitting tube portion 8 and the outer periphery of the elastic member 2. By this tightening allowance, the elastic member 2 is integrated with the stationary member 3, and the handling of the magnetic load sensor 1 is easy.
  • the supported portion 6 of the elastic member 2 is arranged at a position shifted radially outward from the load input portion 5.
  • the elastic member 2 is configured to bend and deform backward in the axial direction with the position of the supported portion 6 as a fulcrum when a load is input.
  • the first load detection unit 4 a and the second load detection unit 4 b are provided at positions shifted by 180 degrees in the circumferential direction, and the center of the elastic member 2 (that is, the axial direction with respect to the elastic member 2). It is arranged at equal intervals in the circumferential direction around the load acting center).
  • the first load detection unit 4a includes a magnetic target 11a that generates magnetic flux and a magnetic sensor unit 12a that detects magnetic flux generated by the magnetic target 11a.
  • the configuration of the first load detection unit 4a will be described below.
  • the first load detection unit 4b The parts corresponding to the load detection unit 4a are denoted by the same reference numerals or the reference numerals in which the alphabet a at the end is replaced with b, and the description thereof is omitted.
  • the magnetic target 11 a is fixed to the inner periphery of the elastic member 2.
  • the magnetic sensor portion 12a is fixed to the outer periphery of the cylindrical portion 9 of the stationary member 3 so as to face the magnetic target 11a in the radial direction.
  • the magnetic target 11a is composed of two permanent magnets 13 magnetized in a direction (here, radial direction) orthogonal to an axial direction that is a relative displacement direction of the magnetic target 11a and the magnetic sensor unit 12a due to the deflection of the elastic member 2.
  • the two permanent magnets 13 are arranged so that the N pole of one permanent magnet 13 and the S pole of the other permanent magnet 13 are adjacent in the axial direction.
  • a neodymium magnet is used as the permanent magnet 13 as the permanent magnet 13, a powerful magnetic flux can be generated in a space-saving manner. May be.
  • a samarium cobalt magnet, a samarium iron nitride magnet, or an alnico magnet is used, a decrease in magnetic flux accompanying a temperature increase of the permanent magnet 13 can be suppressed.
  • a praseodymium magnet is used, the mechanical strength of the permanent magnet 13 can be improved.
  • the magnetic sensor unit 12a is arranged in the vicinity of the boundary between the adjacent N pole and S pole of the two permanent magnets 13 so as to face the magnetic target 11a in the direction perpendicular to the axis (radial direction in the drawing).
  • a magnetoresistive element sino-called MR sensor
  • a magneto-impedance element sino-impedance element
  • using a Hall IC is advantageous in terms of cost and heat resistance. Since a high Hall IC is commercially available, it is suitable for use in an electric brake for a vehicle.
  • the magnetic sensor unit 12a of the first load detection unit 4a is a sensor having a resolution of 16 bits (4096 steps) with respect to the full scale (magnetic detection range). As shown in FIG. 4, the full scale Sa of the magnetic sensor unit 12 a is set so as to be a fluctuation range of the magnetic flux when the magnitude of the axial load inputted to the elastic member 2 fluctuates in the first load region La. Is set.
  • the magnetic sensor unit 12b of the second load detection unit 4b is also a sensor having a resolution of 16 bits (4096 steps) with respect to the full scale (magnetic detection range).
  • the full scale Sb of the magnetic sensor unit 12b is set so as to be a magnetic flux variation range when the magnitude of the axial load input to the elastic member 2 varies in the second load region Lb.
  • region La is an area
  • the second load region Lb is a region where the magnitude of the axial load is from zero to the upper limit value Fmax.
  • the second load region Lb is a range including an axial load larger than the upper limit value Fa of the first load region La
  • the upper limit value Fmax of the second load region Lb is the first load region Lb.
  • the size is set to be twice or more the upper limit value of the load area La.
  • the upper limit value Fmax of the second load region Lb is the magnitude of the maximum load that can be generated by the vehicle brake device.
  • the first load detection unit 4a When the full scale Sa of the magnetic sensor unit 12a of the first load detection unit 4a is set to 1/3 of the full scale Sb of the magnetic sensor unit 12b of the second load detection unit 4b, the first load detection unit 4a The load detection resolution by is three times the load detection resolution by the second load detection unit 4b. For example, when the full scale Sa of the magnetic sensor unit 12a of the first load detection unit 4a is 10 kN and the full scale Sb of the magnetic sensor unit 12b of the second load detection unit 4b is 30 kN, the first load detection unit 4a The load detection resolution is about 2.4N corresponding to 1/4096 of full scale Sa, and the load detection resolution of the second load detection unit 4b is about 7.3N corresponding to 1/4096 of full scale Sb.
  • the first load detection unit 4a has a detection resolution three times that of the second load detection unit 4b.
  • the first load region La is a range of a load that generates a deceleration of 0 to 0.2 G during normal braking that is frequently used as a vehicle brake.
  • the second load region Lb can be set to the entire load region that can be generated by the vehicle brake.
  • the magnetic sensor units 12a and 12b are electrically connected to the control unit 14, and a signal output from the magnetic sensor unit 12a and a signal output from the magnetic sensor unit 12b are respectively controlled by the control unit 14.
  • the control unit 14 is preset with a correspondence relationship between the output signals of the magnetic sensor units 12 a and 12 b and the load values.
  • the control unit 14 is, for example, an electronic control device that controls an electric motor 29 (see FIG. 11) of an electric brake device described later, and a load value that is output based on the output signals Va and Vb of the magnetic sensor units 12a and 12b.
  • the electric motor 29 is controlled based on the above.
  • the control unit 14 calculates the load value fa in the first load detection unit 4a based on the output signal Va of the magnetic sensor unit 12a, and the second load detection unit based on the output signal Vb of the magnetic sensor unit 12b.
  • the load value fb at 4b is calculated.
  • the first load detection unit 4a An average of the load value fa and the load value fb in the second load detector 4b is output as the magnitude of the axial load.
  • the second load detector 4b when the load value fa in the first load detector 4a or the load value fb in the second load detector 4b exceeds the upper limit value Fa of the first load region La, the second load detector 4b.
  • the load value fb is output as the magnitude of the axial load as it is.
  • the first load detection unit 4a having high detection resolution detects the load. Therefore, when this load sensor 1 is used in a vehicle brake device, it is possible to obtain a load detection resolution sufficient to cope with a driver's fine pedal operation during normal braking with a relatively small deceleration. .
  • the second load detector 4b can detect an axial load that is larger than the upper limit value Fa of the first load region La.
  • the load sensor 1 is suitable for a vehicle brake device.
  • the load sensor 1 can detect the axial load in both the first load detection unit 4a and the second load detection unit 4b in the first load region La. Therefore, even when one of the first load detection unit 4a and the second load detection unit 4b fails, the other load detection unit detects the axial load of the first load region La. It is possible and has excellent redundancy.
  • the load sensor 1 can eliminate the influence of the uneven load even when the uneven load (unevenly distributed axial load) is input to the elastic member 2. This will be described below.
  • the distribution of the axial load input to the elastic member 2 is uniform between the position of the first load detection unit 4a and the position of the second load detection unit 4b.
  • the load value fa calculated based on the output signal Va of the first load detector 4a and the load value fb calculated based on the output signal Vb of the second load detector 4b. are consistent with each other.
  • the distribution of the axial load input to the elastic member 2 is non-uniform, and as a result, the axial load acting on the position of the first load detection unit 4a is
  • the load value fa calculated based on the output signal Va of the first load detector 4a is the original value as shown in FIG.
  • the value fb becomes larger than the value f
  • the load value fb calculated based on the output signal Vb of the second load detection unit 4b becomes smaller than the original value f.
  • the load is detected by only one of the first load detection unit 4a and the second load detection unit 4b, it is determined whether or not the axial load input to the elastic member 2 is an unbalanced load. It cannot be known, and the detected load value also includes a large error.
  • the load sensor 1 is based on the load value fa detected based on the signal Va output from the first load detector 4a and the signal Vb output from the second load detector 4b. Since the average of the load value fb detected in this way is output as the magnitude of the axial load, it is output from the load sensor 1 even when the axial load input to the elastic member 2 becomes an unbalanced load.
  • the magnitude of the load is approximately the same as the actual magnitude f of the axial load, and the influence of the offset load can be eliminated.
  • the load sensor 1 includes a magnetic target 11a in which two permanent magnets 13 are arranged side by side so that the north and south poles are adjacent to each other in the axial direction, and the boundary between the adjacent north and south poles. Since the load detection units 4a and 4b having the magnetic sensor unit 12a are employed, a steep magnetic flux change occurs in the vicinity of the boundary between the N pole and the S pole, and this magnetic flux penetrates the magnetic sensor unit 12a. Therefore, the output signal of the magnetic sensor unit 12a changes abruptly according to the minute relative movement between the magnetic target 11a and the magnetic sensor unit 12a, and as a result, high detection resolution can be realized.
  • the output signal of the magnetic sensor unit 12a changes sharply with respect to the relative displacement between the magnetic target 11a and the magnetic sensor unit 12a due to the deformation of the elastic member 2, while the other magnetic target 11a and the magnetic sensor unit 12a Since directivity that does not change so much with respect to the relative displacement occurs, the output signal of the magnetic sensor unit 12a is not easily affected by external vibration, and the magnitude of the load can be detected with stable accuracy.
  • the second load region Lb is set so as to overlap the entire first load region La.
  • the second load region Lb is the first load region La. You may set so that only a part overlaps. Even in this case, the axial load can be detected in a continuous load region that extends over the upper limit value Fa of the first load region La.
  • the magnetic target 11a is being fixed to the elastic member 2, and the magnetic sensor part 12a is being fixed to the stationary member 3, the relationship between this magnetic target 11a and the magnetic sensor part 12a may be reversed. . That is, as shown in FIG. 10, the magnetic sensor unit 12 a may be fixed to the elastic member 2 and the magnetic target 11 a may be fixed to the stationary member 3.
  • the load sensor 1 provided with the two load detectors 4a and 4b at an interval of 180 degrees has been described as an example, but three or more load detectors are arranged in the circumferential direction. You may provide so that it may become equal intervals.
  • the load detectors 4a and 4b may be configured to detect loads by other methods such as strain gauges. Further, as the first load detection unit 4a having a high detection resolution, a magnetic type is adopted as in the above embodiment, and a strain gauge is used as the second load detection unit 4b that detects a load in the entire load region. It is also possible to adopt.
  • FIGS. 11 to 13 show an electric brake device for a vehicle using the magnetic load sensor 1 described above.
  • the electric brake device includes a caliper body 24 having a shape in which opposed pieces 21 and 22 that are opposed to each other with a bridge 23 interposed therebetween with a brake disc 20 that rotates integrally with a wheel, and a facing surface of the opposed piece 21 to the brake disc 20. And a pair of left and right friction pads 27, 28.
  • the friction pad 27 is provided between the opposing piece 21 and the brake disc 20, and is a mount (not shown) that supports the caliper body 24 so as to be slidable in the axial direction with respect to the brake disc 20. It is supported to be movable in the direction.
  • the other friction pad 28 is attached to the opposing piece 22 on the opposite side.
  • the linear actuator 26 includes an electric motor 29 and a motion conversion mechanism 31 that converts the rotation of the electric motor 29 into the axial movement of the outer ring member 30.
  • the motion conversion mechanism 31 includes a rotating shaft 32 to which rotation of the electric motor 29 is input, a plurality of planetary rollers 33 that are in rolling contact with the outer diameter surface of the rotating shaft 32, and the plurality of planetary planets. It has the carrier 34 which hold
  • the rotary shaft 32 is rotationally driven by the rotation of the electric motor 29 shown in FIG.
  • the rotating shaft 32 is inserted into the receiving hole 25 with one end protruding from an opening on the rear side in the axial direction of the receiving hole 25 formed through the opposing piece 21 in the axial direction.
  • the gear 35 is spline-fitted to prevent rotation.
  • the gear 35 is covered with a lid 36 fixed with a bolt so as to close the opening on the rear side in the axial direction of the accommodation hole 25.
  • the planetary roller 33 is in rolling contact with the outer peripheral cylindrical surface of the rotating shaft 32, and the planetary roller 33 is caused by friction between the planetary roller 33 and the rotating shaft 32 when the rotating shaft 32 rotates. Also comes to rotate.
  • a plurality of planetary rollers 33 are provided at regular intervals in the circumferential direction.
  • the outer ring member 30 is supported on the inner periphery of the accommodation hole 25 so as to be slidable in the axial direction.
  • an engagement concave portion 38 that engages with an engagement convex portion 37 formed on the back surface of the friction pad 27 is formed, and the engagement convex portion 37 is engaged with the engagement concave portion 38.
  • a spiral ridge 39 is provided on the inner diameter surface of the outer ring member 30, and a circumferential groove 40 that engages with the spiral ridge 39 is provided on the outer diameter surface of the planetary roller 33, and the planetary roller 33 rotates.
  • the spiral ridge 39 of the outer ring member 30 is guided by the circumferential groove 40 so that the outer ring member 30 moves in the axial direction.
  • the circumferential groove 40 having a lead angle of 0 degrees is provided on the outer diameter surface of the planetary roller 33, but a spiral groove having a lead angle different from that of the spiral protrusion 39 may be provided instead of the circumferential groove 40.
  • the carrier 34 incorporates a thrust bearing 41 that supports the axial rear surface of each planetary roller 33 in a rotatable manner.
  • the load sensor 1 is fitted into the accommodation hole 25 on the rear side in the axial direction of the carrier 34.
  • a spacer 42 that revolves integrally with the carrier 34 and a thrust bearing 43 that supports the spacer 42 so as to revolve are incorporated between the carrier 34 and the load sensor 1.
  • the thrust bearing 43 is provided to be supported in the axial direction by the load input portion 5 of the elastic member 2, and the axial load is applied from the spacer 42 to the load input portion 5 of the elastic member 2 through the thrust bearing 43. Is entered.
  • the rotating shaft 32 is rotatably supported by a bearing 44 incorporated in the cylindrical portion 9 of the stationary member 3.
  • the load sensor 1 is restricted from moving rearward in the axial direction by locking the outer peripheral edge of the stationary member 3 with a protrusion 45 formed on the inner periphery of the rear end of the accommodation hole 25.
  • the load sensor 1 supports the carrier 34 in the axial direction via the spacer 42 and the thrust bearing 43, thereby restricting the movement of the carrier 34 in the rearward direction in the axial direction.
  • the carrier 34 is also restricted from moving forward in the axial direction by a retaining ring 46 attached to the front end of the rotating shaft 32 in the axial direction. Therefore, the carrier 34 is restricted from moving in the axial direction forward and axially backward, and the planetary roller 33 held by the carrier 34 is also restricted from moving in the axial direction.
  • the rotating shaft 32 rotates and the planetary roller 33 revolves around the rotating shaft 32 while rotating.
  • the outer ring member 30 and the planetary roller 33 are moved relative to each other in the axial direction by the engagement of the spiral ridge 39 and the circumferential groove 40.
  • the planetary roller 33 is restricted from moving in the axial direction together with the carrier 34.
  • the roller 33 does not move in the axial direction, and the outer ring member 30 moves in the axial direction.
  • the linear actuator 26 converts the rotation of the rotating shaft 32 driven by the electric motor 29 into the axial movement of the outer ring member 30 and presses the friction pad 27 forward in the axial direction by the outer ring member 30.
  • the friction pad 27 is pressed against the brake disc 20 to generate a braking force.
  • the friction pad 27 when the friction pad 27 is pressed forward in the axial direction by the outer ring member 30, a reaction force in the axial rearward direction acts on the outer ring member 30, and the reaction force is generated by the planetary roller 33, the carrier 34, and the spacer 42.
  • the load sensor 1 receives the thrust bearing 43.
  • the elastic member 2 of the load sensor 1 bends in the axial direction by the reaction force, and the output signals Va and Vb of the first load detector 4a and the second load detector 4b according to the amount of deflection of the elastic member 2. Changes, and the magnitude of the axial load (the pressing force of the friction pad 27) is detected based on the output signals Va and Vb.
  • a mechanism using a planetary roller 33 is adopted as the motion converting mechanism 31 that converts the rotation of the rotating shaft 32 to which the rotation of the electric motor 29 is input into the axial movement of the outer ring member 30.
  • FIG. 14 shows an example of an electric brake device that employs a ball screw mechanism as the motion conversion mechanism 31.
  • portions corresponding to the above embodiment are denoted by the same reference numerals and description thereof is omitted.
  • the motion conversion mechanism 31 includes a screw shaft 50 provided integrally with the rotary shaft 32, a nut 51 provided so as to surround the screw shaft 50, and a screw groove 52 formed on the outer periphery of the screw shaft 50. And a plurality of balls 54 incorporated between screw grooves 53 formed on the inner periphery of the nut 51, and a return tube (not shown) for returning the balls 54 from the end point of the screw groove 53 of the nut 51 to the starting point.
  • the nut 51 is accommodated in the accommodation hole 25 provided in the opposing piece 21 so as to be slidable in the axial direction while being prevented from rotating with respect to the caliper body 24.
  • a spacer 42 that rotates integrally with the screw shaft 50 is provided at the axial rear end of the screw shaft 50, and the spacer 42 is supported by the load sensor 1 via a thrust bearing 43.
  • the load sensor 1 supports the screw shaft 50 in the axial direction via the spacer 42 and the thrust bearing 43, thereby restricting the axial movement of the screw shaft 50 in the rearward direction.
  • This electric brake device converts the rotation of the rotary shaft 32 into the axial movement of a nut 51 as a linear motion member, and presses the friction pad 27 forward in the axial direction with the nut 51, whereby the friction pad 27 is braked to the brake disk. 20 to generate a braking force.
  • a reaction force acting rearward in the axial direction acts on the nut 51, and the reaction force is received by the load sensor 1 via the screw shaft 50, the spacer 42, and the thrust bearing 43.
  • the elastic member 2 of the load sensor 1 bends in the axial direction by the reaction force, and the output signals Va and Vb of the first load detector 4a and the second load detector 4b according to the amount of deflection of the elastic member 2. Changes, and the magnitude of the axial load (the pressing force of the friction pad 27) is detected based on the output signals Va and Vb.
  • FIG. 15 shows an example of an electric brake device that employs a ball ramp mechanism as the motion conversion mechanism 31.
  • the motion conversion mechanism 31 includes a rotating shaft 32, a rotating disk 60 that is prevented from rotating around the outer periphery of the rotating shaft 32, a linearly moving disk 61 that is disposed facing the front of the rotating disk 60 in the axial direction, It has a plurality of balls 62 sandwiched between the rotating disk 60 and the linear motion disk 61.
  • the linear motion disk 61 is accommodated in an accommodation hole 25 provided in the opposed piece 21 so as to be slidable in the axial direction while being prevented from rotating with respect to the caliper body 24.
  • a spacer 42 that rotates integrally with the rotating disk 60 is provided at the rear end in the axial direction of the rotating disk 60, and the spacer 42 is supported by the load sensor 1 via a thrust bearing 43.
  • the load sensor 1 regulates the movement of the rotating disk 60 rearward in the axial direction by supporting the rotating disk 60 in the axial direction via the spacer 42 and the thrust bearing 43.
  • an inclined groove 63 whose depth gradually decreases along one circumferential direction is formed on the surface of the rotating disk 60 facing the linear moving disk 61.
  • An inclined groove 64 whose depth gradually decreases along the other direction of the circumferential direction is formed on the surface facing the rotating disk 60.
  • the ball 62 is incorporated between the inclined groove 63 of the rotating disk 60 and the inclined groove 64 of the linear motion disk 61.
  • the balls 62 roll in the inclined grooves 63 and 64, and the interval between the rotating disk 60 and the linearly moving disk 61 is increased.
  • This electric brake device converts the rotation of the rotating shaft 32 into the axial movement of the linear motion disk 61 as a linear motion member, and presses the friction pad 27 forward in the axial direction with the linear motion disk 61, whereby the friction pad 27 is pressed against the brake disc 20 to generate a braking force.
  • a reaction force acting rearward in the axial direction acts on the rotating disk 60, and the reaction force is received by the load sensor 1 via the spacer 42 and the thrust bearing 43.
  • the elastic member 2 of the load sensor 1 bends in the axial direction by the reaction force, and the output signals Va and Vb of the first load detector 4a and the second load detector 4b according to the amount of deflection of the elastic member 2. Changes, and the magnitude of the axial load (the pressing force of the friction pad 27) is detected based on the output signals Va and Vb.

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Abstract

The present invention provides a load sensor suitable for a vehicle brake apparatus. The load sensor has an elastic member (2) that is elastically deformed by the input of an external load in the axial direction and load detection units (4a, 4b) for outputting a signal corresponding to the amount of elastic deformation of the elastic member (2). In a first load area (La) in which the size of the axial load applied to the elastic member (2) is smaller than a prescribed upper limit value (Fa), a first load detection unit (4a) outputs a signal (Va) corresponding to the amount of deformation of the elastic member (2). In a second load area (Lb) including axial load larger than the upper limit value (Fa) of the first load area (La), a second load detection unit (4b) outputs a signal (Vb) corresponding to the amount of deformation of the elastic member (2). The first load detection unit (4a) and second load detection unit (4b) are configured such that the first load detection unit (4a) has a higher detection resolution than that of the second load detection unit (4b).

Description

荷重センサ、電動式直動アクチュエータおよび電動ブレーキ装置Load sensor, electric linear actuator, and electric brake device
　この発明は、荷重センサ、その荷重センサを用いた電動式直動アクチュエータおよび電動ブレーキ装置に関する。 The present invention relates to a load sensor, an electric linear actuator using the load sensor, and an electric brake device.
　車両用ブレーキ装置として、油圧シリンダで摩擦パッドを押圧する油圧ブレーキ装置が採用されてきたが、近年、ＡＢＳ（アンチロックブレーキシステム）等のブレーキ制御の導入に伴い、油圧回路を使用しない電動ブレーキ装置が注目されている。 As a brake device for a vehicle, a hydraulic brake device that presses a friction pad with a hydraulic cylinder has been adopted. However, with the introduction of brake control such as ABS (anti-lock brake system) in recent years, an electric brake device that does not use a hydraulic circuit. Is attracting attention.
　電動ブレーキ装置は、一般に、電動モータの回転を直動部材の軸方向移動に変換し、その直動部材で摩擦パッドを軸方向前方に押圧して制動力を発生する。この制動力を所望の大きさに制御するため、電動ブレーキ装置には、摩擦パッドに印加する軸方向荷重の反力を受ける部分に荷重センサを組み込むことが多い。そして、この荷重センサの出力に基づいて、運転者のペダル操作や車両の状態に応じた適切な制動力が発生するように、電動モータが制御される。 An electric brake device generally converts the rotation of an electric motor into axial movement of a linear motion member, and presses the friction pad forward in the axial direction with the linear motion member to generate a braking force. In order to control this braking force to a desired magnitude, electric brake devices often incorporate a load sensor in a portion that receives a reaction force of an axial load applied to a friction pad. Based on the output of the load sensor, the electric motor is controlled so that an appropriate braking force corresponding to the driver's pedal operation and the state of the vehicle is generated.
　上記のような電動ブレーキ装置に組み込まれる荷重センサとして、例えば、下記特許文献１～３に記載のものが知られている。特許文献１～３に記載の荷重センサはいずれも、外部から軸方向荷重が入力されて弾性変形を生じる弾性部材と、その弾性部材の変形量に応じた信号を出力する単一の磁気センサ部とを有し、その磁気センサ部の出力に基づいて軸方向荷重の大きさを算出するものである。 As load sensors incorporated in the electric brake device as described above, for example, those described in Patent Documents 1 to 3 below are known. Each of the load sensors described in Patent Documents 1 to 3 has an elastic member that undergoes elastic deformation when an axial load is input from the outside, and a single magnetic sensor unit that outputs a signal corresponding to the deformation amount of the elastic member And the magnitude of the axial load is calculated based on the output of the magnetic sensor unit.
特開２０１３－２５７０００号公報JP 2013-257000 A 特開２０１４－０１６３０７号公報JP 2014-016307 A 特開２０１４－１３４４５０号公報JP 2014-134450 A
　ところで、運転者がブレーキペダルを操作して車両を減速するとき、減速度が０．２Ｇ以下の通常制動時には、運転者は、車両の挙動に応じてペダルを細かく操作していると考えられるので、細かな荷重制御が必要とされる。一方、減速度が０．３Ｇを超えるような急制動時には、短時間で大きな制動力を発生する必要があるものの、細かな荷重制御は必要とされない。 By the way, when the driver decelerates the vehicle by operating the brake pedal, during normal braking with a deceleration of 0.2 G or less, the driver is thought to be operating the pedal finely according to the behavior of the vehicle. Fine load control is required. On the other hand, at the time of sudden braking in which the deceleration exceeds 0.3 G, although it is necessary to generate a large braking force in a short time, fine load control is not required.
　一方、車両用ブレーキ装置に特許文献１～３の荷重センサを採用すると、単一の磁気センサ部を用いて全荷重領域の荷重を検出することとなるため、通常制動時において、運転者の細かなペダル操作に対応するのに十分な荷重の検出分解能を得ることができず、その結果、車両の挙動に違和感が生じるおそれがあった。 On the other hand, when the load sensors disclosed in Patent Documents 1 to 3 are used in the vehicle brake device, the load in the entire load region is detected using a single magnetic sensor unit. Thus, it is impossible to obtain sufficient load detection resolution to cope with a pedal operation. As a result, there is a possibility that the vehicle behavior may be uncomfortable.
　そこで、検出分解能が高く、しかも車両用ブレーキ装置の全荷重領域にわたって荷重を検出可能な荷重センサを使用することも可能であるが、そのような荷重センサはコストが高いという問題がある。 Therefore, it is possible to use a load sensor with high detection resolution and capable of detecting the load over the entire load region of the vehicle brake device, but such a load sensor has a problem of high cost.
　この発明が解決しようとする課題は、車両用ブレーキ装置に好適な荷重センサを提供することである。 The problem to be solved by the present invention is to provide a load sensor suitable for a vehicle brake device.
　上記の課題を解決するため、この発明では、以下の構成の荷重センサを提供する。
　外部から軸方向荷重が入力されて弾性変形を生じる弾性部材と、
　その弾性部材の変形量に応じた信号を出力する２つ以上の荷重検出部とを有し、
　前記２つ以上の荷重検出部は、
　前記弾性部材に入力される軸方向荷重の大きさが所定の上限値よりも小さい第１の荷重領域で、前記弾性部材の変形量に応じた信号を出力する第１の荷重検出部と、
　前記第１の荷重領域の上限値よりも大きい軸方向荷重を含む第２の荷重領域で、前記弾性部材の変形量に応じた信号を出力する第２の荷重検出部とを含み、
　前記第１の荷重検出部および第２の荷重検出部は、第１の荷重検出部が第２の荷重検出部よりも高い検出分解能を有するように構成されている荷重センサ。 In order to solve the above problems, the present invention provides a load sensor having the following configuration.
An elastic member that receives an axial load from the outside and causes elastic deformation;
Two or more load detection units that output a signal corresponding to the deformation amount of the elastic member,
The two or more load detection units are:
A first load detection unit that outputs a signal corresponding to a deformation amount of the elastic member in a first load region in which a magnitude of an axial load input to the elastic member is smaller than a predetermined upper limit;
A second load region that includes an axial load that is greater than the upper limit value of the first load region, and a second load detector that outputs a signal corresponding to the amount of deformation of the elastic member,
The first load detection unit and the second load detection unit are load sensors configured such that the first load detection unit has a higher detection resolution than the second load detection unit.
　このようにすると、軸方向荷重の大きさが小さい第１の荷重領域では、高い検出分解能を有する第１の荷重検出部で荷重を検出することができる。そのため、この荷重センサを車両用ブレーキ装置に使用すると、減速度が比較的小さい通常制動時には、運転者の細かなペダル操作に対応するのに十分な荷重の検出分解能を得ることが可能である。一方、減速度が比較的大きい急制動時には、第２の荷重検出部で、第１の荷重領域の上限値よりも大きい軸方向荷重を検出することが可能である。 In this way, in the first load region where the magnitude of the axial load is small, the load can be detected by the first load detection unit having high detection resolution. Therefore, when this load sensor is used in a vehicle brake device, it is possible to obtain a load detection resolution sufficient to cope with a driver's fine pedal operation during normal braking with a relatively small deceleration. On the other hand, during sudden braking with relatively large deceleration, the second load detection unit can detect an axial load that is larger than the upper limit value of the first load region.
　前記第２の荷重領域は、前記第１の荷重領域と少なくとも一部重複するように設定すると好ましい。 It is preferable that the second load area is set so as to at least partially overlap the first load area.
　このようにすると、前記第１の荷重領域の上限値をまたがる連続した荷重領域において軸方向荷重を検出することができる。 In this way, the axial load can be detected in a continuous load region that extends over the upper limit value of the first load region.
　前記第１の荷重領域は、前記弾性部材に入力される軸方向荷重の大きさがゼロから前記上限値までの領域とし、
　前記第２の荷重領域は、前記弾性部材に入力される軸方向荷重の大きさがゼロから前記上限値の２倍以上の大きさの上限値までの領域とすると好ましい。 The first load region is a region where the magnitude of the axial load input to the elastic member is from zero to the upper limit value,
The second load region is preferably a region in which the magnitude of the axial load input to the elastic member is from zero to an upper limit value that is twice or more the upper limit value.
　このようにすると、第１の荷重領域では、第１の荷重検出部と第２の荷重検出部の両方で軸方向荷重を検出することができる。そのため、第１の荷重検出部と第２の荷重検出部のいずれか一方の荷重検出部が故障したときにも、他方の荷重検出部で第１の荷重領域の軸方向荷重を検出可能であり、優れた冗長性を得ることができる。 In this way, in the first load region, the axial load can be detected by both the first load detection unit and the second load detection unit. Therefore, even when one of the first load detection unit and the second load detection unit fails, the other load detection unit can detect the axial load in the first load region. Excellent redundancy can be obtained.
　前記２つ以上の荷重検出部は、前記弾性部材に対する軸方向荷重の作用中心まわりに円周方向に等間隔となるように配置すると好ましい。 It is preferable that the two or more load detection units are arranged at equal intervals in the circumferential direction around the center of action of the axial load on the elastic member.
　このようにすると、外部から弾性部材に入力される軸方向荷重が偏荷重になったときにも、各荷重検出部から出力される信号を併用することで、偏荷重の影響を排除することが可能となる。 In this way, even when the axial load input to the elastic member from the outside becomes an unbalanced load, it is possible to eliminate the influence of the unbalanced load by using a signal output from each load detection unit together. It becomes possible.
　また、前記第１の荷重検出部と第２の荷重検出部から出力されるそれぞれの信号が入力され、その各信号に基づいて前記第１の荷重検出部での荷重値と第２の荷重検出部での荷重値とをそれぞれ算出し、前記第１の荷重領域では、前記第１の荷重検出部での荷重値と第２の荷重検出部での荷重値とを平均したものを前記軸方向荷重の大きさとして出力する制御部を設けると好ましい。 Further, the respective signals output from the first load detection unit and the second load detection unit are input, and the load value and the second load detection in the first load detection unit based on the respective signals. The load value at the first portion is calculated, and in the first load region, the average of the load value at the first load detection portion and the load value at the second load detection portion is the axial direction. It is preferable to provide a control unit that outputs the magnitude of the load.
　このようにすると、外部から弾性部材に入力される軸方向荷重が偏荷重になったときにも、偏荷重の影響を排除することが可能となる。 In this way, even when the axial load input to the elastic member from the outside becomes an unbalanced load, it is possible to eliminate the influence of the unbalanced load.
　前記第１の荷重検出部として、磁界を発生する磁気ターゲットと、その磁気ターゲットに対する相対位置が前記弾性部材の変形量に応じて変化するように配置された磁気センサ部とからなるものを採用し、
　前記磁気ターゲットとして、前記弾性部材の変形による磁気ターゲットと磁気センサ部の相対変位方向に対して直交する方向に磁化された２つの永久磁石を、一方の永久磁石のＮ極と他方の永久磁石のＳ極が前記磁気ターゲットと磁気センサ部の相対変位方向に隣接するように配置したものを採用し、
　前記磁気センサ部を、前記隣接するＮ極とＳ極の境目の近傍に配置すると好ましい。 As the first load detection unit, a unit composed of a magnetic target that generates a magnetic field and a magnetic sensor unit arranged so that a relative position with respect to the magnetic target changes according to a deformation amount of the elastic member is adopted. ,
As the magnetic target, two permanent magnets magnetized in a direction orthogonal to the relative displacement direction of the magnetic target and the magnetic sensor unit due to the deformation of the elastic member are the N pole of one permanent magnet and the other permanent magnet. Adopting the S pole so as to be adjacent in the relative displacement direction of the magnetic target and the magnetic sensor unit,
It is preferable that the magnetic sensor unit is disposed in the vicinity of the boundary between the adjacent north and south poles.
　このようにすると、Ｎ極とＳ極の境目の近傍に急峻な磁束変化が生じ、この磁束が磁気センサ部を貫く状態となる。そのため、磁気ターゲットと磁気センサ部の微小な相対移動に応じて、磁気センサ部の出力信号が急峻に変化し、その結果、高い検出分解能を実現することが可能となる。また、磁気センサ部の出力信号は、弾性部材の変形による磁気ターゲットと磁気センサ部の相対変位に対して急峻に変化し、一方、それ以外の磁気ターゲットと磁気センサ部の相対変位に対してはあまり変化しないという指向性が生じるため、磁気センサ部の出力信号が外部振動の影響を受けにくく、安定した精度で荷重の大きさを検出することが可能となる。 In this way, a steep magnetic flux change occurs in the vicinity of the boundary between the N pole and the S pole, and this magnetic flux penetrates the magnetic sensor section. Therefore, the output signal of the magnetic sensor unit changes sharply according to the minute relative movement between the magnetic target and the magnetic sensor unit, and as a result, high detection resolution can be realized. In addition, the output signal of the magnetic sensor unit changes sharply with respect to the relative displacement between the magnetic target and the magnetic sensor unit due to the deformation of the elastic member. Since directivity that does not change much occurs, the output signal of the magnetic sensor unit is not easily influenced by external vibration, and the magnitude of the load can be detected with stable accuracy.
　また、この発明では、上記荷重センサを使用した電動式直動アクチュエータとして、以下の構成のものを提供する。
　電動モータと、その電動モータの回転を直動部材の軸方向移動に変換する運動変換機構とを有する電動式直動アクチュエータにおいて、
　前記直動部材で対象物を軸方向前方に押圧したときに直動部材に作用する軸方向後方への反力を受ける部分に、上記荷重センサを組み込んだことを特徴とする電動式直動アクチュエータ。 Moreover, in this invention, the thing of the following structures is provided as an electrically driven linear motion actuator using the said load sensor.
In an electric linear actuator having an electric motor and a motion conversion mechanism that converts rotation of the electric motor into axial movement of the linear member,
An electric linear motion actuator, wherein the load sensor is incorporated in a portion that receives a reaction force in the axial rearward direction that acts on the linear motion member when the object is pressed forward in the axial direction by the linear motion member. .
　前記運動変換機構としては、前記電動モータの回転が入力される回転軸と、その回転軸の外径面に転がり接触する複数の遊星ローラと、その複数の遊星ローラを自転可能かつ公転可能に保持するキャリヤと、前記複数の遊星ローラを囲むように配置された前記直動部材としての外輪部材と、その外輪部材の内径面に設けられた螺旋凸条と、その螺旋凸条と係合するように前記各遊星ローラの外径面に設けられた螺旋溝または円周溝とを有するものを採用することができる。この場合、前記弾性部材は、前記キャリヤをスラスト軸受を介して支持することで前記キャリヤの軸方向後方への移動を規制する部材とすることができる。 The motion conversion mechanism includes a rotating shaft to which rotation of the electric motor is input, a plurality of planetary rollers that are in rolling contact with the outer diameter surface of the rotating shaft, and a plurality of planetary rollers that can rotate and revolve. A carrier to be engaged, an outer ring member as the linear motion member disposed so as to surround the plurality of planetary rollers, a spiral ridge provided on an inner diameter surface of the outer ring member, and the spiral ridge to be engaged with the outer ring member. Further, it is possible to employ one having a spiral groove or a circumferential groove provided on the outer diameter surface of each planetary roller. In this case, the elastic member can be a member that restricts the movement of the carrier in the axially rearward direction by supporting the carrier via a thrust bearing.
　また、この発明では、上記荷重センサを使用した電動ブレーキ装置として、以下の構成のものを提供する。
　電動モータと、その電動モータの回転を直動部材の軸方向移動に変換する運動変換機構とを有し、前記直動部材で摩擦パッドを軸方向前方に押圧して制動力を発生する電動ブレーキ装置において、
　前記直動部材で摩擦パッドを軸方向前方に押圧したときに直動部材に作用する軸方向後方への反力を受ける部分に、上記荷重センサを組み込んだことを特徴とする電動ブレーキ装置。 Moreover, in this invention, the thing of the following structures is provided as an electric brake device which uses the said load sensor.
An electric brake having an electric motor and a motion conversion mechanism for converting rotation of the electric motor into axial movement of the linear motion member, and generating a braking force by pressing the friction pad forward in the axial direction by the linear motion member In the device
An electric brake device, wherein the load sensor is incorporated in a portion that receives a reaction force in the axial rearward direction that acts on the linear motion member when the friction pad is pressed forward in the axial direction by the linear motion member.
　この発明の荷重センサは、軸方向荷重の大きさが小さい第１の荷重領域では、高い検出分解能を有する第１の荷重検出部が荷重を検出する。そのため、この荷重センサを車両用ブレーキ装置に使用すると、減速度が比較的小さい通常制動時には、運転者の細かなペダル操作に対応するのに十分な荷重の検出分解能を得ることが可能である。一方、減速度が比較的大きい急制動時には、第２の荷重検出部で、第１の荷重領域の上限値よりも大きい軸方向荷重を検出することが可能である。したがって、この発明の荷重センサは、車両用ブレーキ装置に好適である。 In the load sensor of the present invention, in the first load region where the magnitude of the axial load is small, the first load detection unit having high detection resolution detects the load. Therefore, when this load sensor is used in a vehicle brake device, it is possible to obtain a load detection resolution sufficient to cope with a driver's fine pedal operation during normal braking with a relatively small deceleration. On the other hand, during sudden braking with relatively large deceleration, the second load detection unit can detect an axial load that is larger than the upper limit value of the first load region. Therefore, the load sensor of the present invention is suitable for a vehicle brake device.
この発明の実施形態の荷重センサを示す断面図Sectional drawing which shows the load sensor of embodiment of this invention 図１に示す荷重センサを軸方向前側から見た図The load sensor shown in FIG. 1 is viewed from the front side in the axial direction. 図１に示す荷重センサの第１の荷重検出部の近傍の拡大断面図The expanded sectional view of the vicinity of the 1st load detection part of the load sensor shown in FIG. 弾性部材に入力する軸方向荷重の大きさと磁気センサ部で検出される磁束との対応関係を示す図The figure which shows the correspondence of the magnitude | size of the axial load input into an elastic member, and the magnetic flux detected by a magnetic sensor part 各荷重検出部の磁気センサ部の出力信号に基づいて軸方向荷重の大きさを算出する制御部のブロック図Block diagram of a control unit that calculates the magnitude of the axial load based on the output signal of the magnetic sensor unit of each load detection unit 各荷重検出部の磁気センサ部の出力信号と荷重値との対応関係を示す図The figure which shows the correspondence of the output signal of a magnetic sensor part of each load detection part, and a load value 図１に示す荷重センサに偏荷重が作用した状態を模式的に示す図The figure which shows typically the state in which the eccentric load acted on the load sensor shown in FIG. 図７に示す状態での各荷重検出部の磁気センサ部の出力信号と荷重値との対応関係を示す図The figure which shows the correspondence of the output signal and load value of the magnetic sensor part of each load detection part in the state shown in FIG. 図４に示す第２の荷重領域Ｌｂを、第１の荷重領域Ｌａと一部のみ重複するように変更した例を示す図The figure which shows the example which changed the 2nd load area | region Lb shown in FIG. 4 so that it may partially overlap with the 1st load area | region La. 図３に示す磁気ターゲットと磁気センサ部の配置を変更した例を示す拡大断面図FIG. 3 is an enlarged sectional view showing an example in which the arrangement of the magnetic target and the magnetic sensor unit shown in FIG. 図１に示す荷重センサを使用した車両用の電動ブレーキ装置を示す断面図Sectional drawing which shows the electric brake device for vehicles using the load sensor shown in FIG. 図１１の直動アクチュエータ近傍の拡大断面図Fig. 11 is an enlarged cross-sectional view of the vicinity of the linear actuator 図１２のXIII－XIII線に沿った断面図Sectional view along line XIII-XIII in FIG. 図１２に示す遊星ローラ機構にかえてボールねじ機構を運動変換機構として採用した電動ブレーキ装置を示す断面図Sectional drawing which shows the electric brake device which employ | adopted the ball screw mechanism as a motion conversion mechanism instead of the planetary roller mechanism shown in FIG. 図１２に示す遊星ローラ機構にかえてボールランプ機構を運動変換機構として採用した電動ブレーキ装置を示す断面図Sectional drawing which shows the electric brake device which employ | adopted the ball ramp mechanism as a motion conversion mechanism instead of the planetary roller mechanism shown in FIG. 図１５のXVI－XVI線に沿った断面図Sectional view along line XVI-XVI in FIG. （ａ）は図１６に示すボールと傾斜溝の関係を示す図、（ｂ）は（ａ）に示す状態から回転ディスクと直動ディスクが相対回転して両ディスクの間隔が拡大した状態を示す図16A is a view showing the relationship between the ball and the inclined groove shown in FIG. 16, and FIG. 16B is a view showing a state in which the rotation disk and the linear motion disk are relatively rotated from the state shown in FIG. Figure
　図１～図３に、この発明の実施形態の荷重センサ１を示す。この荷重センサ１は、軸方向前方から荷重が入力されて弾性変形を生じる弾性部材２と、弾性部材２を軸方向後方から支持する静止部材３と、弾性部材２の変形量に応じた信号を出力する第１の荷重検出部４ａおよび第２の荷重検出部４ｂとを有する。 1 to 3 show a load sensor 1 according to an embodiment of the present invention. The load sensor 1 includes an elastic member 2 that generates elastic deformation when a load is input from the front in the axial direction, a stationary member 3 that supports the elastic member 2 from the rear in the axial direction, and a signal corresponding to the deformation amount of the elastic member 2. It has the 1st load detection part 4a and the 2nd load detection part 4b which output.
　弾性部材２は、鉄等の金属で形成された円環板状の部材である。弾性部材２の軸方向前面には、軸方向荷重が入力される荷重入力部５が設けられている。図では、荷重入力部５は、後述のスラスト軸受４３（図１２参照）の転動体の転走面とされている。弾性部材２の軸方向後面には、静止部材３で支持される被支持部６が設けられている。 The elastic member 2 is a ring-shaped member formed of a metal such as iron. A load input portion 5 for inputting an axial load is provided on the front surface in the axial direction of the elastic member 2. In the figure, the load input portion 5 is a rolling surface of a rolling element of a thrust bearing 43 (see FIG. 12) described later. A supported portion 6 supported by the stationary member 3 is provided on the rear surface in the axial direction of the elastic member 2.
　静止部材３は、金属で形成されており、その金属は磁性材料であることが好ましい。静止部材３は、弾性部材２の被支持部６を軸方向後方から支持する環状の支持部７と、弾性部材２の外周に嵌合するように支持部７の外径側に形成された嵌合筒部８と、弾性部材２の内径側に対向するように設けられた円筒部９と、弾性部材２の軸方向後方で円筒部９と支持部７の間を連結する連結部１０とを有する。嵌合筒部８の内周と弾性部材２の外周の間には締め代が設定されている。この締め代によって、弾性部材２が静止部材３と一体化し、磁気式荷重センサ１の取り扱いが容易となっている。 The stationary member 3 is made of metal, and the metal is preferably a magnetic material. The stationary member 3 includes an annular support portion 7 that supports the supported portion 6 of the elastic member 2 from the rear in the axial direction, and a fitting formed on the outer diameter side of the support portion 7 so as to be fitted to the outer periphery of the elastic member 2. A combination tube portion 8, a cylindrical portion 9 provided so as to face the inner diameter side of the elastic member 2, and a connecting portion 10 that connects the cylindrical portion 9 and the support portion 7 in the axially rearward direction of the elastic member 2. Have. A tightening margin is set between the inner periphery of the fitting tube portion 8 and the outer periphery of the elastic member 2. By this tightening allowance, the elastic member 2 is integrated with the stationary member 3, and the handling of the magnetic load sensor 1 is easy.
　弾性部材２の被支持部６は、荷重入力部５よりも径方向外方にずれた位置に配置されている。これにより、弾性部材２は、荷重が入力されたときに被支持部６の位置を支点として軸方向後方にたわみ変形を生じるようになっている。 The supported portion 6 of the elastic member 2 is arranged at a position shifted radially outward from the load input portion 5. As a result, the elastic member 2 is configured to bend and deform backward in the axial direction with the position of the supported portion 6 as a fulcrum when a load is input.
　図２に示すように、第１の荷重検出部４ａと第２の荷重検出部４ｂは、円周方向に１８０度ずれた位置に設けられ、弾性部材２の中心（すなわち弾性部材２に対する軸方向荷重の作用中心）まわりに円周方向に等間隔となるように配置されている。第１の荷重検出部４ａは、磁束を発生する磁気ターゲット１１ａと、磁気ターゲット１１ａが発生する磁束を検出する磁気センサ部１２ａとからなる。 As shown in FIG. 2, the first load detection unit 4 a and the second load detection unit 4 b are provided at positions shifted by 180 degrees in the circumferential direction, and the center of the elastic member 2 (that is, the axial direction with respect to the elastic member 2). It is arranged at equal intervals in the circumferential direction around the load acting center). The first load detection unit 4a includes a magnetic target 11a that generates magnetic flux and a magnetic sensor unit 12a that detects magnetic flux generated by the magnetic target 11a.
　第１の荷重検出部４ａと第２の荷重検出部４ｂは、同様の構成なので、第１の荷重検出部４ａの構成を以下に説明し、第２の荷重検出部４ｂについては、第１の荷重検出部４ａに対応する部分に同一の符号または末尾のアルファベットａをｂに置き換えた符号を付して説明を省略する。 Since the first load detection unit 4a and the second load detection unit 4b have the same configuration, the configuration of the first load detection unit 4a will be described below. For the second load detection unit 4b, the first load detection unit 4b The parts corresponding to the load detection unit 4a are denoted by the same reference numerals or the reference numerals in which the alphabet a at the end is replaced with b, and the description thereof is omitted.
　図３に示すように、磁気ターゲット１１ａは、弾性部材２の内周に固定されている。磁気センサ部１２ａは、磁気ターゲット１１ａと径方向に対向するように静止部材３の円筒部９の外周に固定されている。磁気ターゲット１１ａは、弾性部材２のたわみによる磁気ターゲット１１ａと磁気センサ部１２ａの相対変位方向である軸方向に対して直交する方向（ここでは半径方向）に磁化された２個の永久磁石１３からなる。２個の永久磁石１３は、一方の永久磁石１３のＮ極と他方の永久磁石１３のＳ極が軸方向に隣接するように配置されている。 As shown in FIG. 3, the magnetic target 11 a is fixed to the inner periphery of the elastic member 2. The magnetic sensor portion 12a is fixed to the outer periphery of the cylindrical portion 9 of the stationary member 3 so as to face the magnetic target 11a in the radial direction. The magnetic target 11a is composed of two permanent magnets 13 magnetized in a direction (here, radial direction) orthogonal to an axial direction that is a relative displacement direction of the magnetic target 11a and the magnetic sensor unit 12a due to the deflection of the elastic member 2. Become. The two permanent magnets 13 are arranged so that the N pole of one permanent magnet 13 and the S pole of the other permanent magnet 13 are adjacent in the axial direction.
　永久磁石１３としては、例えば、ネオジム磁石を使用すると、省スペースで強力な磁束を発生させることができるが、サマリウムコバルト磁石、サマリウム窒化鉄磁石、アルニコ磁石、フェライト磁石、プラセオジム磁石、などを使用してもよい。サマリウムコバルト磁石、サマリウム窒化鉄磁石、またはアルニコ磁石を使用すると、永久磁石１３の温度上昇に伴う磁束の減少を抑えることができる。また、プラセオジム磁石を使用すると、永久磁石１３の機械的強度を向上することができる。 For example, if a neodymium magnet is used as the permanent magnet 13, a powerful magnetic flux can be generated in a space-saving manner. May be. When a samarium cobalt magnet, a samarium iron nitride magnet, or an alnico magnet is used, a decrease in magnetic flux accompanying a temperature increase of the permanent magnet 13 can be suppressed. Further, when a praseodymium magnet is used, the mechanical strength of the permanent magnet 13 can be improved.
　磁気センサ部１２ａは、２個の永久磁石１３の隣接するＮ極とＳ極の境目の近傍で、磁気ターゲット１１ａと軸直交方向（図では半径方向）に対向するように配置されている。磁気センサ部１２ａとしては、磁気抵抗素子（いわゆるＭＲセンサ）や、磁気インピーダンス素子（いわゆるＭＩセンサ）を使用することも可能であるが、ホールＩＣを使用するとコスト面で有利であり、また耐熱性の高いホールＩＣが市販されているので車両用の電動ブレーキの用途に好適である。 The magnetic sensor unit 12a is arranged in the vicinity of the boundary between the adjacent N pole and S pole of the two permanent magnets 13 so as to face the magnetic target 11a in the direction perpendicular to the axis (radial direction in the drawing). As the magnetic sensor portion 12a, a magnetoresistive element (so-called MR sensor) or a magneto-impedance element (so-called MI sensor) can be used, but using a Hall IC is advantageous in terms of cost and heat resistance. Since a high Hall IC is commercially available, it is suitable for use in an electric brake for a vehicle.
　図１の矢印に示すように、軸方向前方から後方に向かう軸方向荷重が弾性部材２に入力されると、その軸方向荷重によって弾性部材２が外径側端部を支点として軸方向後方にたわみ、このたわみに伴い、磁気ターゲット１１ａと磁気センサ部１２ａが軸方向に相対変位し、磁気センサ部１２ａの出力信号が弾性部材２のたわみ量に応じて変化する。そのため、弾性部材２に入力される軸方向荷重の大きさと、磁気センサ部１２ａの出力信号との関係を予め把握しておくことにより、磁気センサ部１２ａの出力信号に基づいて弾性部材２に入力される軸方向荷重の大きさを検出することができる。 As shown by the arrows in FIG. 1, when an axial load from the front in the axial direction to the rear is input to the elastic member 2, the elastic member 2 moves rearward in the axial direction with the outer diameter side end as a fulcrum by the axial load. With the deflection, the magnetic target 11a and the magnetic sensor unit 12a are relatively displaced in the axial direction, and the output signal of the magnetic sensor unit 12a changes according to the deflection amount of the elastic member 2. Therefore, by knowing in advance the relationship between the magnitude of the axial load input to the elastic member 2 and the output signal of the magnetic sensor unit 12a, the input to the elastic member 2 based on the output signal of the magnetic sensor unit 12a. The magnitude of the axial load applied can be detected.
　第１の荷重検出部４ａの磁気センサ部１２ａは、フルスケール（磁気検出範囲）に対し１６ｂｉｔ（４０９６段階）の分解能をもつセンサである。図４に示すように、磁気センサ部１２ａのフルスケールＳａは、弾性部材２に入力される軸方向荷重の大きさが第１の荷重領域Ｌａで変動するときの磁束の変動範囲となるように設定される。 The magnetic sensor unit 12a of the first load detection unit 4a is a sensor having a resolution of 16 bits (4096 steps) with respect to the full scale (magnetic detection range). As shown in FIG. 4, the full scale Sa of the magnetic sensor unit 12 a is set so as to be a fluctuation range of the magnetic flux when the magnitude of the axial load inputted to the elastic member 2 fluctuates in the first load region La. Is set.
　第２の荷重検出部４ｂの磁気センサ部１２ｂも、フルスケール（磁気検出範囲）に対し１６ｂｉｔ（４０９６段階）の分解能をもつセンサである。磁気センサ部１２ｂのフルスケールＳｂは、弾性部材２に入力される軸方向荷重の大きさが第２の荷重領域Ｌｂで変動するときの磁束の変動範囲となるように設定される。 The magnetic sensor unit 12b of the second load detection unit 4b is also a sensor having a resolution of 16 bits (4096 steps) with respect to the full scale (magnetic detection range). The full scale Sb of the magnetic sensor unit 12b is set so as to be a magnetic flux variation range when the magnitude of the axial load input to the elastic member 2 varies in the second load region Lb.
　第１の荷重領域Ｌａは、軸方向荷重の大きさがゼロから上限値Ｆａまでの領域である。第２の荷重領域Ｌｂは、軸方向荷重の大きさがゼロから上限値Ｆｍａｘまでの領域である。ここで、第２の荷重領域Ｌｂは、第１の荷重領域Ｌａの上限値Ｆａよりも大きい軸方向荷重を含むような範囲とされ、第２の荷重領域Ｌｂの上限値Ｆｍａｘは、第１の荷重領域Ｌａの上限値の２倍以上の大きさに設定されている。この実施形態では、第２の荷重領域Ｌｂの上限値Ｆｍａｘは、車両用ブレーキ装置で発生しうる最大荷重の大きさとされている。 1st load area | region La is an area | region from the magnitude | size of an axial load to zero to the upper limit Fa. The second load region Lb is a region where the magnitude of the axial load is from zero to the upper limit value Fmax. Here, the second load region Lb is a range including an axial load larger than the upper limit value Fa of the first load region La, and the upper limit value Fmax of the second load region Lb is the first load region Lb. The size is set to be twice or more the upper limit value of the load area La. In this embodiment, the upper limit value Fmax of the second load region Lb is the magnitude of the maximum load that can be generated by the vehicle brake device.
　第１の荷重検出部４ａの磁気センサ部１２ａのフルスケールＳａを、第２の荷重検出部４ｂの磁気センサ部１２ｂのフルスケールＳｂの１／３に設定した場合、第１の荷重検出部４ａによる荷重の検出分解能は、第２の荷重検出部４ｂによる荷重の検出分解能の３倍となる。例えば、第１の荷重検出部４ａの磁気センサ部１２ａのフルスケールＳａが１０ｋＮ、第２の荷重検出部４ｂの磁気センサ部１２ｂのフルスケールＳｂが３０ｋＮとすると、第１の荷重検出部４ａによる荷重の検出分解能はフルスケールＳａの４０９６分の１に相当する約２．４Ｎ、第２の荷重検出部４ｂによる荷重の検出分解能はフルスケールＳｂの４０９６分の１に相当する約７．３Ｎとなり、第１の荷重検出部４ａは第２の荷重検出部４ｂの３倍の検出分解能を有することとなる。 When the full scale Sa of the magnetic sensor unit 12a of the first load detection unit 4a is set to 1/3 of the full scale Sb of the magnetic sensor unit 12b of the second load detection unit 4b, the first load detection unit 4a The load detection resolution by is three times the load detection resolution by the second load detection unit 4b. For example, when the full scale Sa of the magnetic sensor unit 12a of the first load detection unit 4a is 10 kN and the full scale Sb of the magnetic sensor unit 12b of the second load detection unit 4b is 30 kN, the first load detection unit 4a The load detection resolution is about 2.4N corresponding to 1/4096 of full scale Sa, and the load detection resolution of the second load detection unit 4b is about 7.3N corresponding to 1/4096 of full scale Sb. The first load detection unit 4a has a detection resolution three times that of the second load detection unit 4b.
　この荷重センサ１を車両用の電動ブレーキ装置に使用する場合、第１の荷重領域Ｌａは、車両用ブレーキとしての使用頻度の高い通常制動時の減速度０～０．２Ｇを発生させる荷重の範囲に設定し、第２の荷重領域Ｌｂは、車両用ブレーキで発生しうる全荷重領域に設定することができる。 When this load sensor 1 is used in an electric brake device for a vehicle, the first load region La is a range of a load that generates a deceleration of 0 to 0.2 G during normal braking that is frequently used as a vehicle brake. The second load region Lb can be set to the entire load region that can be generated by the vehicle brake.
　図５に示すように、磁気センサ部１２ａ，１２ｂは制御部１４に電気的に接続され、磁気センサ部１２ａから出力される信号と、磁気センサ部１２ｂから出力される信号とがそれぞれ制御部１４に入力されるようになっている。制御部１４には、図６に示すように、各磁気センサ部１２ａ，１２ｂの出力信号と荷重値との対応関係が予め設定されている。制御部１４は、例えば、後述の電動ブレーキ装置の電動モータ２９（図１１参照）を制御する電子制御装置であり、磁気センサ部１２ａ，１２ｂの出力信号Ｖａ，Ｖｂに基づいて出力される荷重値に基づいて電動モータ２９を制御する。 As shown in FIG. 5, the magnetic sensor units 12a and 12b are electrically connected to the control unit 14, and a signal output from the magnetic sensor unit 12a and a signal output from the magnetic sensor unit 12b are respectively controlled by the control unit 14. To be input. As shown in FIG. 6, the control unit 14 is preset with a correspondence relationship between the output signals of the magnetic sensor units 12 a and 12 b and the load values. The control unit 14 is, for example, an electronic control device that controls an electric motor 29 (see FIG. 11) of an electric brake device described later, and a load value that is output based on the output signals Va and Vb of the magnetic sensor units 12a and 12b. The electric motor 29 is controlled based on the above.
　制御部１４は、磁気センサ部１２ａの出力信号Ｖａに基づいて第１の荷重検出部４ａでの荷重値ｆａを算出するとともに、磁気センサ部１２ｂの出力信号Ｖｂに基づいて第２の荷重検出部４ｂでの荷重値ｆｂを算出する。そして、第１の荷重検出部４ａでの荷重値ｆａと第２の荷重検出部４ｂでの荷重値ｆｂとがいずれも第１の荷重領域Ｌａにあるとき、第１の荷重検出部４ａでの荷重値ｆａと第２の荷重検出部４ｂでの荷重値ｆｂとを平均したものを軸方向荷重の大きさとして出力する。一方、第１の荷重検出部４ａでの荷重値ｆａまたは第２の荷重検出部４ｂでの荷重値ｆｂが第１の荷重領域Ｌａの上限値Ｆａを超えるときは、第２の荷重検出部４ｂでの荷重値ｆｂをそのまま軸方向荷重の大きさとして出力する。 The control unit 14 calculates the load value fa in the first load detection unit 4a based on the output signal Va of the magnetic sensor unit 12a, and the second load detection unit based on the output signal Vb of the magnetic sensor unit 12b. The load value fb at 4b is calculated. When both the load value fa in the first load detection unit 4a and the load value fb in the second load detection unit 4b are in the first load region La, the first load detection unit 4a An average of the load value fa and the load value fb in the second load detector 4b is output as the magnitude of the axial load. On the other hand, when the load value fa in the first load detector 4a or the load value fb in the second load detector 4b exceeds the upper limit value Fa of the first load region La, the second load detector 4b. The load value fb is output as the magnitude of the axial load as it is.
　この荷重センサ１は、軸方向荷重の大きさが小さい第１の荷重領域Ｌａでは、高い検出分解能を有する第１の荷重検出部４ａが荷重を検出する。そのため、この荷重センサ１を車両用ブレーキ装置に使用すると、減速度が比較的小さい通常制動時には、運転者の細かなペダル操作に対応するのに十分な荷重の検出分解能を得ることが可能である。一方、減速度が比較的大きい急制動時には、第２の荷重検出部４ｂで、第１の荷重領域Ｌａの上限値Ｆａよりも大きい軸方向荷重を検出することが可能である。このように、荷重センサ１は車両用ブレーキ装置に好適である。 In the load sensor 1, in the first load region La in which the magnitude of the axial load is small, the first load detection unit 4a having high detection resolution detects the load. Therefore, when this load sensor 1 is used in a vehicle brake device, it is possible to obtain a load detection resolution sufficient to cope with a driver's fine pedal operation during normal braking with a relatively small deceleration. . On the other hand, during sudden braking with a relatively large deceleration, the second load detector 4b can detect an axial load that is larger than the upper limit value Fa of the first load region La. Thus, the load sensor 1 is suitable for a vehicle brake device.
　また、この荷重センサ１は、第１の荷重領域Ｌａでは、第１の荷重検出部４ａと第２の荷重検出部４ｂの両方で軸方向荷重を検出することができる。そのため、第１の荷重検出部４ａと第２の荷重検出部４ｂのいずれか一方の荷重検出部が故障したときにも、他方の荷重検出部で第１の荷重領域Ｌａの軸方向荷重を検出可能であり、優れた冗長性を有する。 Further, the load sensor 1 can detect the axial load in both the first load detection unit 4a and the second load detection unit 4b in the first load region La. Therefore, even when one of the first load detection unit 4a and the second load detection unit 4b fails, the other load detection unit detects the axial load of the first load region La. It is possible and has excellent redundancy.
　また、この荷重センサ１は、弾性部材２に偏荷重（不均一な分布の軸方向荷重）が入力されたときにも、その偏荷重の影響を排除することが可能である。以下説明する。 Further, the load sensor 1 can eliminate the influence of the uneven load even when the uneven load (unevenly distributed axial load) is input to the elastic member 2. This will be described below.
　すなわち、図１の矢印に示すように、弾性部材２に入力される軸方向荷重の分布が、第１の荷重検出部４ａの位置と第２の荷重検出部４ｂの位置とで均一である場合、図６に示すように、第１の荷重検出部４ａの出力信号Ｖａに基づいて算出される荷重値ｆａと、第２の荷重検出部４ｂの出力信号Ｖｂに基づいて算出される荷重値ｆｂとは互いに一致する。 That is, as shown by the arrows in FIG. 1, the distribution of the axial load input to the elastic member 2 is uniform between the position of the first load detection unit 4a and the position of the second load detection unit 4b. As shown in FIG. 6, the load value fa calculated based on the output signal Va of the first load detector 4a and the load value fb calculated based on the output signal Vb of the second load detector 4b. Are consistent with each other.
　一方、図７の矢印に示すように、弾性部材２に入力される軸方向荷重の分布が不均一であり、その結果、第１の荷重検出部４ａの位置に作用する軸方向荷重が、第２の荷重検出部４ｂの位置に作用する軸方向荷重よりも大きくなる場合、図８に示すように、第１の荷重検出部４ａの出力信号Ｖａに基づいて算出される荷重値ｆａは本来の値ｆよりも大きくなり、第２の荷重検出部４ｂの出力信号Ｖｂに基づいて算出される荷重値ｆｂは本来の値ｆよりも小さくなる。すなわち、弾性部材２に偏荷重が入力されたとき、第１の荷重検出部４ａでの荷重値ｆａと第２の荷重検出部４ｂでの荷重値ｆｂのうち、いずれか一方の荷重値が本来の値ｆよりも大きくなり、他方の荷重値が本来の値ｆよりも小さくなる傾向がある。 On the other hand, as shown by the arrow in FIG. 7, the distribution of the axial load input to the elastic member 2 is non-uniform, and as a result, the axial load acting on the position of the first load detection unit 4a is When the load is larger than the axial load acting on the position of the second load detector 4b, the load value fa calculated based on the output signal Va of the first load detector 4a is the original value as shown in FIG. The value fb becomes larger than the value f, and the load value fb calculated based on the output signal Vb of the second load detection unit 4b becomes smaller than the original value f. That is, when an unbalanced load is input to the elastic member 2, one of the load value fa in the first load detection unit 4a and the load value fb in the second load detection unit 4b is originally There is a tendency that the other load value becomes smaller than the original value f.
　このとき、もし仮に第１の荷重検出部４ａと第２の荷重検出部４ｂのいずれか一方のみで荷重を検出するとすれば、弾性部材２に入力される軸方向荷重が偏荷重か否かを知ることはできず、検出される荷重の値も大きな誤差を含んだものとなってしまう。 At this time, if the load is detected by only one of the first load detection unit 4a and the second load detection unit 4b, it is determined whether or not the axial load input to the elastic member 2 is an unbalanced load. It cannot be known, and the detected load value also includes a large error.
　これに対し、上記の荷重センサ１は、第１の荷重検出部４ａから出力される信号Ｖａに基づいて検出される荷重値ｆａと、第２の荷重検出部４ｂから出力される信号Ｖｂに基づいて検出される荷重値ｆｂとを平均したものを軸方向荷重の大きさとして出力するので、弾性部材２に入力される軸方向荷重が偏荷重になったときにも、荷重センサ１から出力される荷重の大きさが、実際の軸方向荷重の大きさｆと概ね一致し、偏荷重の影響を排除することが可能である。 On the other hand, the load sensor 1 is based on the load value fa detected based on the signal Va output from the first load detector 4a and the signal Vb output from the second load detector 4b. Since the average of the load value fb detected in this way is output as the magnitude of the axial load, it is output from the load sensor 1 even when the axial load input to the elastic member 2 becomes an unbalanced load. The magnitude of the load is approximately the same as the actual magnitude f of the axial load, and the influence of the offset load can be eliminated.
　また、この荷重センサ１は、２つの永久磁石１３をＮ極とＳ極が軸方向に隣接するように並べて配置した磁気ターゲット１１ａと、その隣接するＮ極とＳ極の境目の近傍に配置した磁気センサ部１２ａとを有する荷重検出部４ａ，４ｂを採用しているので、Ｎ極とＳ極の境目の近傍に急峻な磁束変化が生じ、この磁束が磁気センサ部１２ａを貫く状態となる。そのため、磁気ターゲット１１ａと磁気センサ部１２ａの微小な相対移動に応じて、磁気センサ部１２ａの出力信号が急峻に変化し、その結果、高い検出分解能を実現することが可能である。また、磁気センサ部１２ａの出力信号は、弾性部材２の変形による磁気ターゲット１１ａと磁気センサ部１２ａの相対変位に対して急峻に変化し、一方、それ以外の磁気ターゲット１１ａと磁気センサ部１２ａの相対変位に対してはあまり変化しないという指向性が生じるため、磁気センサ部１２ａの出力信号が外部振動の影響を受けにくく、安定した精度で荷重の大きさを検出することが可能となる。 In addition, the load sensor 1 includes a magnetic target 11a in which two permanent magnets 13 are arranged side by side so that the north and south poles are adjacent to each other in the axial direction, and the boundary between the adjacent north and south poles. Since the load detection units 4a and 4b having the magnetic sensor unit 12a are employed, a steep magnetic flux change occurs in the vicinity of the boundary between the N pole and the S pole, and this magnetic flux penetrates the magnetic sensor unit 12a. Therefore, the output signal of the magnetic sensor unit 12a changes abruptly according to the minute relative movement between the magnetic target 11a and the magnetic sensor unit 12a, and as a result, high detection resolution can be realized. Further, the output signal of the magnetic sensor unit 12a changes sharply with respect to the relative displacement between the magnetic target 11a and the magnetic sensor unit 12a due to the deformation of the elastic member 2, while the other magnetic target 11a and the magnetic sensor unit 12a Since directivity that does not change so much with respect to the relative displacement occurs, the output signal of the magnetic sensor unit 12a is not easily affected by external vibration, and the magnitude of the load can be detected with stable accuracy.
　上記実施形態では、第１の荷重領域Ｌａの全体と重複するように第２の荷重領域Ｌｂを設定したが、図９に示すように、第２の荷重領域Ｌｂは、第１の荷重領域Ｌａと一部のみ重複するように設定してもよい。このようにしても、第１の荷重領域Ｌａの上限値Ｆａをまたがる連続した荷重領域において軸方向荷重を検出することができる。 In the above embodiment, the second load region Lb is set so as to overlap the entire first load region La. However, as shown in FIG. 9, the second load region Lb is the first load region La. You may set so that only a part overlaps. Even in this case, the axial load can be detected in a continuous load region that extends over the upper limit value Fa of the first load region La.
　また、上記実施形態では、弾性部材２に磁気ターゲット１１ａを固定し、静止部材３に磁気センサ部１２ａを固定しているが、この磁気ターゲット１１ａと磁気センサ部１２ａの関係を反対にしてもよい。すなわち、図１０に示すように、弾性部材２に磁気センサ部１２ａを固定し、静止部材３に磁気ターゲット１１ａを固定してもよい。 Moreover, in the said embodiment, although the magnetic target 11a is being fixed to the elastic member 2, and the magnetic sensor part 12a is being fixed to the stationary member 3, the relationship between this magnetic target 11a and the magnetic sensor part 12a may be reversed. . That is, as shown in FIG. 10, the magnetic sensor unit 12 a may be fixed to the elastic member 2 and the magnetic target 11 a may be fixed to the stationary member 3.
　また、上記実施形態では、２つの荷重検出部４ａ，４ｂを１８０度の間隔となるように設けた荷重センサ１を例に挙げて説明したが、３つ以上の荷重検出部を円周方向に等間隔となるように設けてもよい。 In the above embodiment, the load sensor 1 provided with the two load detectors 4a and 4b at an interval of 180 degrees has been described as an example, but three or more load detectors are arranged in the circumferential direction. You may provide so that it may become equal intervals.
　荷重検出部４ａ，４ｂは、例えば歪ゲージなど他の方式で荷重を検出する構成のものを採用してもよい。また、高い検出分解能を有する第１の荷重検出部４ａとして、上記実施形態のように磁気式のものを採用し、全荷重領域において荷重を検出する第２の荷重検出部４ｂとして、歪ゲージを採用することも可能である。 The load detectors 4a and 4b may be configured to detect loads by other methods such as strain gauges. Further, as the first load detection unit 4a having a high detection resolution, a magnetic type is adopted as in the above embodiment, and a strain gauge is used as the second load detection unit 4b that detects a load in the entire load region. It is also possible to adopt.
　図１１～図１３に、上記の磁気式荷重センサ１を使用した車両用の電動ブレーキ装置を示す。 FIGS. 11 to 13 show an electric brake device for a vehicle using the magnetic load sensor 1 described above.
　この電動ブレーキ装置は、車輪と一体に回転するブレーキディスク２０を間に挟んで対向する対向片２１，２２をブリッジ２３で連結した形状のキャリパボディ２４と、対向片２１のブレーキディスク２０に対する対向面に開口する収容孔２５に組み込まれた直動アクチュエータ２６と、左右一対の摩擦パッド２７，２８とからなる。 The electric brake device includes a caliper body 24 having a shape in which opposed pieces 21 and 22 that are opposed to each other with a bridge 23 interposed therebetween with a brake disc 20 that rotates integrally with a wheel, and a facing surface of the opposed piece 21 to the brake disc 20. And a pair of left and right friction pads 27, 28.
　摩擦パッド２７は、対向片２１とブレーキディスク２０の間に設けられており、キャリパボディ２４をブレーキディスク２０に対し軸方向にスライド可能に支持するマウント（図示せず）で、ブレーキディスク２０の軸方向に移動可能に支持されている。他方の摩擦パッド２８は反対側の対向片２２に取り付けられている。直動アクチュエータ２６は、電動モータ２９と、その電動モータ２９の回転を外輪部材３０の軸方向移動に変換する運動変換機構３１とを有する。 The friction pad 27 is provided between the opposing piece 21 and the brake disc 20, and is a mount (not shown) that supports the caliper body 24 so as to be slidable in the axial direction with respect to the brake disc 20. It is supported to be movable in the direction. The other friction pad 28 is attached to the opposing piece 22 on the opposite side. The linear actuator 26 includes an electric motor 29 and a motion conversion mechanism 31 that converts the rotation of the electric motor 29 into the axial movement of the outer ring member 30.
　図１２に示すように、運動変換機構３１は、電動モータ２９の回転が入力される回転軸３２と、その回転軸３２の外径面に転がり接触する複数の遊星ローラ３３と、その複数の遊星ローラ３３を自転可能かつ公転可能に保持するキャリヤ３４と、複数の遊星ローラ３３を囲むように配置された直動部材としての外輪部材３０とを有する。 As shown in FIG. 12, the motion conversion mechanism 31 includes a rotating shaft 32 to which rotation of the electric motor 29 is input, a plurality of planetary rollers 33 that are in rolling contact with the outer diameter surface of the rotating shaft 32, and the plurality of planetary planets. It has the carrier 34 which hold | maintains the roller 33 so that rotation and revolution are possible, and the outer ring | wheel member 30 as a linear motion member arrange | positioned so that the several planetary roller 33 may be enclosed.
　回転軸３２は、図１１に示す電動モータ２９の回転が歯車３５を介して入力されることにより回転駆動される。回転軸３２は、対向片２１を軸方向に貫通して形成された収容孔２５の軸方向後側の開口から一端が突出した状態で収容孔２５に挿入され、収容孔２５からの突出部分に歯車３５がスプライン嵌合して回り止めされている。歯車３５は、収容孔２５の軸方向後側の開口を塞ぐようにボルトで固定した蓋３６で覆われている。 The rotary shaft 32 is rotationally driven by the rotation of the electric motor 29 shown in FIG. The rotating shaft 32 is inserted into the receiving hole 25 with one end protruding from an opening on the rear side in the axial direction of the receiving hole 25 formed through the opposing piece 21 in the axial direction. The gear 35 is spline-fitted to prevent rotation. The gear 35 is covered with a lid 36 fixed with a bolt so as to close the opening on the rear side in the axial direction of the accommodation hole 25.
　図１３に示すように、遊星ローラ３３は、回転軸３２の外周の円筒面に転がり接触しており、回転軸３２が回転したときに遊星ローラ３３と回転軸３２の間の摩擦によって遊星ローラ３３も回転するようになっている。遊星ローラ３３は、周方向に一定の間隔をおいて複数設けられている。 As shown in FIG. 13, the planetary roller 33 is in rolling contact with the outer peripheral cylindrical surface of the rotating shaft 32, and the planetary roller 33 is caused by friction between the planetary roller 33 and the rotating shaft 32 when the rotating shaft 32 rotates. Also comes to rotate. A plurality of planetary rollers 33 are provided at regular intervals in the circumferential direction.
　図１２に示すように、外輪部材３０は、収容孔２５の内周で軸方向にスライド可能に支持されている。外輪部材３０の軸方向前端には、摩擦パッド２７の背面に形成された係合凸部３７に係合する係合凹部３８が形成され、この係合凸部３７と係合凹部３８の係合によって、外輪部材３０がキャリパボディ２４に対して回り止めされている。 As shown in FIG. 12, the outer ring member 30 is supported on the inner periphery of the accommodation hole 25 so as to be slidable in the axial direction. At the front end in the axial direction of the outer ring member 30, an engagement concave portion 38 that engages with an engagement convex portion 37 formed on the back surface of the friction pad 27 is formed, and the engagement convex portion 37 is engaged with the engagement concave portion 38. Thus, the outer ring member 30 is prevented from rotating with respect to the caliper body 24.
　外輪部材３０の内径面には螺旋凸条３９が設けられ、遊星ローラ３３の外径面には、螺旋凸条３９に係合する円周溝４０が設けられており、遊星ローラ３３が回転したときに、外輪部材３０の螺旋凸条３９が円周溝４０に案内されて、外輪部材３０が軸方向に移動するようになっている。ここでは遊星ローラ３３の外径面にリード角が０度の円周溝４０を設けているが、円周溝４０のかわりに螺旋凸条３９と異なるリード角をもつ螺旋溝を設けてもよい。 A spiral ridge 39 is provided on the inner diameter surface of the outer ring member 30, and a circumferential groove 40 that engages with the spiral ridge 39 is provided on the outer diameter surface of the planetary roller 33, and the planetary roller 33 rotates. Sometimes, the spiral ridge 39 of the outer ring member 30 is guided by the circumferential groove 40 so that the outer ring member 30 moves in the axial direction. Here, the circumferential groove 40 having a lead angle of 0 degrees is provided on the outer diameter surface of the planetary roller 33, but a spiral groove having a lead angle different from that of the spiral protrusion 39 may be provided instead of the circumferential groove 40. .
　キャリヤ３４には、各遊星ローラ３３の軸方向後面を自転可能に支持するスラスト軸受４１が組み込まれている。収容孔２５内には、キャリヤ３４の軸方向後方に荷重センサ１が嵌め込まれている。キャリヤ３４と荷重センサ１の間には、キャリヤ３４と一体に公転する間座４２と、間座４２を公転可能に支持するスラスト軸受４３とが組み込まれている。 The carrier 34 incorporates a thrust bearing 41 that supports the axial rear surface of each planetary roller 33 in a rotatable manner. The load sensor 1 is fitted into the accommodation hole 25 on the rear side in the axial direction of the carrier 34. A spacer 42 that revolves integrally with the carrier 34 and a thrust bearing 43 that supports the spacer 42 so as to revolve are incorporated between the carrier 34 and the load sensor 1.
　スラスト軸受４３は、弾性部材２の荷重入力部５で軸方向に支持されるように設けられており、このスラスト軸受４３を介して間座４２から弾性部材２の荷重入力部５に軸方向荷重が入力されるようになっている。回転軸３２は、静止部材３の円筒部９内に組み込まれた軸受４４で回転可能に支持されている。 The thrust bearing 43 is provided to be supported in the axial direction by the load input portion 5 of the elastic member 2, and the axial load is applied from the spacer 42 to the load input portion 5 of the elastic member 2 through the thrust bearing 43. Is entered. The rotating shaft 32 is rotatably supported by a bearing 44 incorporated in the cylindrical portion 9 of the stationary member 3.
　荷重センサ１は、静止部材３の外周縁を、収容孔２５の後端部内周に形成された突起４５で係止することによって軸方向後方への移動が規制されている。そして、この荷重センサ１は、間座４２とスラスト軸受４３とを介してキャリヤ３４を軸方向に支持することで、キャリヤ３４の軸方向後方への移動を規制している。また、キャリヤ３４は、回転軸３２の軸方向前端に装着された止め輪４６で軸方向前方への移動も規制されている。したがって、キャリヤ３４は、軸方向前方と軸方向後方の移動がいずれも規制され、キャリヤ３４に保持された遊星ローラ３３も軸方向移動が規制された状態となっている。 The load sensor 1 is restricted from moving rearward in the axial direction by locking the outer peripheral edge of the stationary member 3 with a protrusion 45 formed on the inner periphery of the rear end of the accommodation hole 25. The load sensor 1 supports the carrier 34 in the axial direction via the spacer 42 and the thrust bearing 43, thereby restricting the movement of the carrier 34 in the rearward direction in the axial direction. Further, the carrier 34 is also restricted from moving forward in the axial direction by a retaining ring 46 attached to the front end of the rotating shaft 32 in the axial direction. Therefore, the carrier 34 is restricted from moving in the axial direction forward and axially backward, and the planetary roller 33 held by the carrier 34 is also restricted from moving in the axial direction.
　次に、上述した電動ブレーキ装置の動作例を説明する。 Next, an operation example of the above-described electric brake device will be described.
　電動モータ２９を作動させると、回転軸３２が回転し、遊星ローラ３３が自転しながら回転軸３２を中心に公転する。このとき螺旋凸条３９と円周溝４０の係合によって外輪部材３０と遊星ローラ３３が軸方向に相対移動するが、遊星ローラ３３はキャリヤ３４と共に軸方向の移動が規制されているので、遊星ローラ３３は軸方向に移動せず、外輪部材３０が軸方向に移動する。このようにして、直動アクチュエータ２６は、電動モータ２９で駆動される回転軸３２の回転を外輪部材３０の軸方向移動に変換し、その外輪部材３０で摩擦パッド２７を軸方向前方に押圧することで、摩擦パッド２７をブレーキディスク２０に押し付けて制動力を発生させる。 When the electric motor 29 is operated, the rotating shaft 32 rotates and the planetary roller 33 revolves around the rotating shaft 32 while rotating. At this time, the outer ring member 30 and the planetary roller 33 are moved relative to each other in the axial direction by the engagement of the spiral ridge 39 and the circumferential groove 40. However, the planetary roller 33 is restricted from moving in the axial direction together with the carrier 34. The roller 33 does not move in the axial direction, and the outer ring member 30 moves in the axial direction. In this manner, the linear actuator 26 converts the rotation of the rotating shaft 32 driven by the electric motor 29 into the axial movement of the outer ring member 30 and presses the friction pad 27 forward in the axial direction by the outer ring member 30. As a result, the friction pad 27 is pressed against the brake disc 20 to generate a braking force.
　ここで、外輪部材３０で摩擦パッド２７を軸方向前方に押圧するとき、外輪部材３０には軸方向後方への反力が作用し、その反力は、遊星ローラ３３、キャリヤ３４、間座４２、スラスト軸受４３を介して荷重センサ１で受け止められる。そして、その反力によって荷重センサ１の弾性部材２が軸方向後方にたわみ、弾性部材２のたわみ量に応じて第１の荷重検出部４ａと第２の荷重検出部４ｂの出力信号Ｖａ，Ｖｂが変化し、この出力信号Ｖａ，Ｖｂに基づいて軸方向荷重の大きさ（摩擦パッド２７の押圧力）が検出される。 Here, when the friction pad 27 is pressed forward in the axial direction by the outer ring member 30, a reaction force in the axial rearward direction acts on the outer ring member 30, and the reaction force is generated by the planetary roller 33, the carrier 34, and the spacer 42. The load sensor 1 receives the thrust bearing 43. The elastic member 2 of the load sensor 1 bends in the axial direction by the reaction force, and the output signals Va and Vb of the first load detector 4a and the second load detector 4b according to the amount of deflection of the elastic member 2. Changes, and the magnitude of the axial load (the pressing force of the friction pad 27) is detected based on the output signals Va and Vb.
　この電動ブレーキ装置では、電動モータ２９の回転が入力される回転軸３２の回転を外輪部材３０の軸方向移動に変換する運動変換機構３１として、遊星ローラ３３を用いた機構を採用したが、他の構成の運動変換機構３１を採用してもよい。 In this electric brake device, a mechanism using a planetary roller 33 is adopted as the motion converting mechanism 31 that converts the rotation of the rotating shaft 32 to which the rotation of the electric motor 29 is input into the axial movement of the outer ring member 30. You may employ | adopt the motion conversion mechanism 31 of the structure of these.
　運動変換機構３１としてボールねじ機構を採用した電動ブレーキ装置の例を図１４に示す。以下、上記実施形態に対応する部分は、同一の符号を付して説明を省略する。 FIG. 14 shows an example of an electric brake device that employs a ball screw mechanism as the motion conversion mechanism 31. Hereinafter, portions corresponding to the above embodiment are denoted by the same reference numerals and description thereof is omitted.
　図１４において、運動変換機構３１は、回転軸３２と一体に設けられたねじ軸５０と、ねじ軸５０を囲むように設けられたナット５１と、ねじ軸５０の外周に形成されたねじ溝５２とナット５１の内周に形成されたねじ溝５３の間に組み込まれた複数のボール５４と、ナット５１のねじ溝５３の終点から始点にボール５４を戻す図示しないリターンチューブとを有する。 In FIG. 14, the motion conversion mechanism 31 includes a screw shaft 50 provided integrally with the rotary shaft 32, a nut 51 provided so as to surround the screw shaft 50, and a screw groove 52 formed on the outer periphery of the screw shaft 50. And a plurality of balls 54 incorporated between screw grooves 53 formed on the inner periphery of the nut 51, and a return tube (not shown) for returning the balls 54 from the end point of the screw groove 53 of the nut 51 to the starting point.
　ナット５１は、対向片２１に設けられた収容孔２５内に、キャリパボディ２４に対して回り止めされた状態で軸方向にスライド可能に収容されている。ねじ軸５０の軸方向後端にはねじ軸５０と一体に回転する間座４２が設けられ、その間座４２がスラスト軸受４３を介して荷重センサ１で支持されている。ここで、荷重センサ１は、間座４２とスラスト軸受４３とを介してねじ軸５０を軸方向に支持することで、ねじ軸５０の軸方向後方への移動を規制している。 The nut 51 is accommodated in the accommodation hole 25 provided in the opposing piece 21 so as to be slidable in the axial direction while being prevented from rotating with respect to the caliper body 24. A spacer 42 that rotates integrally with the screw shaft 50 is provided at the axial rear end of the screw shaft 50, and the spacer 42 is supported by the load sensor 1 via a thrust bearing 43. Here, the load sensor 1 supports the screw shaft 50 in the axial direction via the spacer 42 and the thrust bearing 43, thereby restricting the axial movement of the screw shaft 50 in the rearward direction.
　この電動ブレーキ装置は、回転軸３２の回転を直動部材としてのナット５１の軸方向移動に変換し、そのナット５１で摩擦パッド２７を軸方向前方に押圧することで、摩擦パッド２７をブレーキディスク２０に押し付けて制動力を発生させる。このとき、ナット５１には、軸方向後方への反力が作用し、その反力は、ねじ軸５０、間座４２、スラスト軸受４３を介して荷重センサ１で受け止められる。そして、その反力によって荷重センサ１の弾性部材２が軸方向後方にたわみ、弾性部材２のたわみ量に応じて第１の荷重検出部４ａと第２の荷重検出部４ｂの出力信号Ｖａ，Ｖｂが変化し、この出力信号Ｖａ，Ｖｂに基づいて軸方向荷重の大きさ（摩擦パッド２７の押圧力）が検出される。 This electric brake device converts the rotation of the rotary shaft 32 into the axial movement of a nut 51 as a linear motion member, and presses the friction pad 27 forward in the axial direction with the nut 51, whereby the friction pad 27 is braked to the brake disk. 20 to generate a braking force. At this time, a reaction force acting rearward in the axial direction acts on the nut 51, and the reaction force is received by the load sensor 1 via the screw shaft 50, the spacer 42, and the thrust bearing 43. The elastic member 2 of the load sensor 1 bends in the axial direction by the reaction force, and the output signals Va and Vb of the first load detector 4a and the second load detector 4b according to the amount of deflection of the elastic member 2. Changes, and the magnitude of the axial load (the pressing force of the friction pad 27) is detected based on the output signals Va and Vb.
　また、運動変換機構３１としてボールランプ機構を採用した電動ブレーキ装置の例を図１５に示す。 FIG. 15 shows an example of an electric brake device that employs a ball ramp mechanism as the motion conversion mechanism 31.
　図１５において、運動変換機構３１は、回転軸３２と、回転軸３２の外周に回り止めされた回転ディスク６０と、回転ディスク６０の軸方向前方に対向して配置された直動ディスク６１と、回転ディスク６０と直動ディスク６１の間に挟まれた複数のボール６２とを有する。 In FIG. 15, the motion conversion mechanism 31 includes a rotating shaft 32, a rotating disk 60 that is prevented from rotating around the outer periphery of the rotating shaft 32, a linearly moving disk 61 that is disposed facing the front of the rotating disk 60 in the axial direction, It has a plurality of balls 62 sandwiched between the rotating disk 60 and the linear motion disk 61.
　直動ディスク６１は、対向片２１に設けられた収容孔２５内に、キャリパボディ２４に対して回り止めされた状態で軸方向にスライド可能に収容されている。回転ディスク６０の軸方向後端には回転ディスク６０と一体に回転する間座４２が設けられ、その間座４２がスラスト軸受４３を介して荷重センサ１で支持されている。ここで、荷重センサ１は、間座４２とスラスト軸受４３とを介して回転ディスク６０を軸方向に支持することで回転ディスク６０の軸方向後方への移動を規制している。 The linear motion disk 61 is accommodated in an accommodation hole 25 provided in the opposed piece 21 so as to be slidable in the axial direction while being prevented from rotating with respect to the caliper body 24. A spacer 42 that rotates integrally with the rotating disk 60 is provided at the rear end in the axial direction of the rotating disk 60, and the spacer 42 is supported by the load sensor 1 via a thrust bearing 43. Here, the load sensor 1 regulates the movement of the rotating disk 60 rearward in the axial direction by supporting the rotating disk 60 in the axial direction via the spacer 42 and the thrust bearing 43.
　図１５、図１６に示すように、回転ディスク６０の直動ディスク６１に対する対向面には、周方向の一方向に沿って深さが次第に浅くなる傾斜溝６３が形成され、直動ディスク６１の回転ディスク６０に対する対向面には、周方向の他方向に沿って深さが次第に浅くなる傾斜溝６４が形成されている。図１７（ａ）に示すように、ボール６２は、回転ディスク６０の傾斜溝６３と直動ディスク６１の傾斜溝６４の間に組み込まれており、図１７（ｂ）に示すように、直動ディスク６１に対して回転ディスク６０が相対回転すると、傾斜溝６３，６４内をボール６２が転動して、回転ディスク６０と直動ディスク６１の間隔が拡大するようになっている。 As shown in FIGS. 15 and 16, an inclined groove 63 whose depth gradually decreases along one circumferential direction is formed on the surface of the rotating disk 60 facing the linear moving disk 61. An inclined groove 64 whose depth gradually decreases along the other direction of the circumferential direction is formed on the surface facing the rotating disk 60. As shown in FIG. 17A, the ball 62 is incorporated between the inclined groove 63 of the rotating disk 60 and the inclined groove 64 of the linear motion disk 61. As shown in FIG. When the rotating disk 60 rotates relative to the disk 61, the balls 62 roll in the inclined grooves 63 and 64, and the interval between the rotating disk 60 and the linearly moving disk 61 is increased.
　この電動ブレーキ装置は、回転軸３２の回転を直動部材としての直動ディスク６１の軸方向移動に変換し、その直動ディスク６１で摩擦パッド２７を軸方向前方に押圧することで、摩擦パッド２７をブレーキディスク２０に押し付けて制動力を発生させる。このとき、回転ディスク６０には、軸方向後方への反力が作用し、その反力は、間座４２、スラスト軸受４３を介して荷重センサ１で受け止められる。そして、その反力によって荷重センサ１の弾性部材２が軸方向後方にたわみ、弾性部材２のたわみ量に応じて第１の荷重検出部４ａと第２の荷重検出部４ｂの出力信号Ｖａ，Ｖｂが変化し、この出力信号Ｖａ，Ｖｂに基づいて軸方向荷重の大きさ（摩擦パッド２７の押圧力）が検出される。 This electric brake device converts the rotation of the rotating shaft 32 into the axial movement of the linear motion disk 61 as a linear motion member, and presses the friction pad 27 forward in the axial direction with the linear motion disk 61, whereby the friction pad 27 is pressed against the brake disc 20 to generate a braking force. At this time, a reaction force acting rearward in the axial direction acts on the rotating disk 60, and the reaction force is received by the load sensor 1 via the spacer 42 and the thrust bearing 43. The elastic member 2 of the load sensor 1 bends in the axial direction by the reaction force, and the output signals Va and Vb of the first load detector 4a and the second load detector 4b according to the amount of deflection of the elastic member 2. Changes, and the magnitude of the axial load (the pressing force of the friction pad 27) is detected based on the output signals Va and Vb.
　今回開示された実施の形態はすべての点で例示であって制限的なものではないと考えられるべきである。本発明の範囲は上記した説明ではなくて特許請求の範囲によって示され、特許請求の範囲と均等の意味および範囲内でのすべての変更が含まれることが意図される。 The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
２　　　　　弾性部材
４ａ　　　　第１の荷重検出部
４ｂ　　　　第２の荷重検出部
１１ａ　　　磁気ターゲット
１２ａ　　　磁気センサ部
１３　　　　永久磁石
１４　　　　制御部
２６　　　　電動式直動アクチュエータ
２７　　　　摩擦パッド
２９　　　　電動モータ
３０　　　　外輪部材
３１　　　　運動変換機構
３２　　　　回転軸
３３　　　　遊星ローラ
３４　　　　キャリヤ
３９　　　　螺旋凸条
４０　　　　円周溝
４３　　　　スラスト軸受
Ｆａ，Ｆｍａｘ　上限値
Ｌａ　　　　第１の荷重領域
Ｌｂ　　　　第２の荷重領域
Ｖａ，Ｖｂ　出力信号
ｆａ，ｆｂ　荷重値 2 Elastic member 4a 1st load detection part 4b 2nd load detection part 11a Magnetic target 12a Magnetic sensor part 13 Permanent magnet 14 Control part 26 Electric linear motion actuator 27 Friction pad 29 Electric motor 30 Outer ring member 31 Motion conversion mechanism 32 Rotating shaft 33 Planetary roller 34 Carrier 39 Spiral ridge 40 Circumferential groove 43 Thrust bearing Fa, Fmax Upper limit value La First load region Lb Second load region Va, Vb Output signals fa, fb Load value

Claims (9)

  1. 　外部から軸方向荷重が入力されて弾性変形を生じる弾性部材（２）と、
    　その弾性部材（２）の変形量に応じた信号を出力する２つ以上の荷重検出部（４ａ，４ｂ）とを有し、
    　前記２つ以上の荷重検出部（４ａ，４ｂ）は、
    　前記弾性部材（２）に入力される軸方向荷重の大きさが所定の上限値（Ｆａ）よりも小さい第１の荷重領域（Ｌａ）で、前記弾性部材（２）の変形量に応じた信号（Ｖａ）を出力する第１の荷重検出部（４ａ）と、
    　前記第１の荷重領域（Ｌａ）の上限値（Ｆａ）よりも大きい軸方向荷重を含む第２の荷重領域（Ｌｂ）で、前記弾性部材（２）の変形量に応じた信号（Ｖｂ）を出力する第２の荷重検出部（４ｂ）とを含み、
    　前記第１の荷重検出部（４ａ）および第２の荷重検出部（４ｂ）は、第１の荷重検出部（４ａ）が第２の荷重検出部（４ｂ）よりも高い検出分解能を有するように構成されている荷重センサ。     An elastic member (2) that receives an axial load from the outside and causes elastic deformation;
    Two or more load detectors (4a, 4b) for outputting a signal corresponding to the deformation amount of the elastic member (2),
    The two or more load detection units (4a, 4b)
    A signal corresponding to the amount of deformation of the elastic member (2) in the first load region (La) in which the magnitude of the axial load input to the elastic member (2) is smaller than a predetermined upper limit (Fa). A first load detector (4a) that outputs (Va);
    In the second load region (Lb) including an axial load larger than the upper limit value (Fa) of the first load region (La), a signal (Vb) corresponding to the deformation amount of the elastic member (2) is obtained. A second load detector (4b) for outputting,
    The first load detection unit (4a) and the second load detection unit (4b) are configured so that the first load detection unit (4a) has a higher detection resolution than the second load detection unit (4b). The configured load sensor.
  2. 　前記第２の荷重領域（Ｌｂ）は、前記第１の荷重領域（Ｌａ）と少なくとも一部重複するように設定されている請求項１に記載の荷重センサ。 The load sensor according to claim 1, wherein the second load region (Lb) is set so as to at least partially overlap the first load region (La).
  3. 　前記第１の荷重領域（Ｌａ）は、前記弾性部材（２）に入力される軸方向荷重の大きさがゼロから前記上限値（Ｆａ）までの領域であり、
    　前記第２の荷重領域（Ｌｂ）は、前記弾性部材（２）に入力される軸方向荷重の大きさがゼロから前記上限値（Ｆａ）の２倍以上の大きさの上限値（Ｆｍａｘ）までの領域である請求項１または２に記載の荷重センサ。     The first load region (La) is a region where the magnitude of the axial load input to the elastic member (2) is from zero to the upper limit (Fa),
    In the second load region (Lb), the magnitude of the axial load input to the elastic member (2) is from zero to an upper limit value (Fmax) that is twice or more the upper limit value (Fa). The load sensor according to claim 1, wherein the load sensor is a region of
  4. 　前記２つ以上の荷重検出部（４ａ，４ｂ）が、前記弾性部材（２）に対する軸方向荷重の作用中心まわりに円周方向に等間隔となるように配置されている請求項１から３のいずれかに記載の荷重センサ。 The two or more load detectors (4a, 4b) are arranged so as to be equally spaced in the circumferential direction around the center of action of the axial load on the elastic member (2). A load sensor according to any one of the above.
  5. 　前記第１の荷重検出部（４ａ）と第２の荷重検出部（４ｂ）から出力されるそれぞれの信号（Ｖａ，Ｖｂ）が入力され、その各信号（Ｖａ，Ｖｂ）に基づいて前記第１の荷重検出部（４ａ）での荷重値（ｆａ）と第２の荷重検出部（４ｂ）での荷重値（ｆｂ）とをそれぞれ算出し、前記第１の荷重領域（Ｌａ）では、前記第１の荷重検出部（４ａ）での荷重値（ｆａ）と第２の荷重検出部（４ｂ）での荷重値（ｆｂ）とを平均したものを前記軸方向荷重の大きさとして出力する制御部（１４）を更に有する請求項１から４のいずれかに記載の荷重センサ。 Respective signals (Va, Vb) output from the first load detection unit (4a) and the second load detection unit (4b) are input, and the first load detection unit (4a) is input based on the respective signals (Va, Vb). The load value (fa) at the load detection unit (4a) and the load value (fb) at the second load detection unit (4b) are respectively calculated, and the first load region (La) A control unit that outputs an average of the load value (fa) in the first load detection unit (4a) and the load value (fb) in the second load detection unit (4b) as the magnitude of the axial load. The load sensor according to any one of claims 1 to 4, further comprising (14).
  6. 　前記第１の荷重検出部（４ａ）は、磁界を発生する磁気ターゲット（１１ａ）と、その磁気ターゲット（１１ａ）に対する相対位置が前記弾性部材（２）の変形量に応じて変化するように配置された磁気センサ部（１２ａ）とからなり、
    　前記磁気ターゲット（１１ａ）は、前記弾性部材（２）の変形による磁気ターゲット（１１ａ）と磁気センサ部（１２ａ）の相対変位方向に対して直交する方向に磁化された２つの永久磁石（１３）を、一方の永久磁石（１３）のＮ極と他方の永久磁石（１３）のＳ極が前記磁気ターゲット（１１ａ）と磁気センサ部（１２ａ）の相対変位方向に隣接するように配置したものであり、
    　前記磁気センサ部（１２ａ）は、前記隣接するＮ極とＳ極の境目の近傍に配置されている請求項１から５のいずれかに記載の荷重センサ。     The first load detector (4a) is arranged such that the magnetic target (11a) that generates a magnetic field and the relative position of the magnetic target (11a) change according to the amount of deformation of the elastic member (2). The magnetic sensor unit (12a)
    The magnetic target (11a) includes two permanent magnets (13) magnetized in a direction perpendicular to the relative displacement direction of the magnetic target (11a) and the magnetic sensor unit (12a) due to deformation of the elastic member (2). Is arranged so that the N pole of one permanent magnet (13) and the S pole of the other permanent magnet (13) are adjacent to each other in the relative displacement direction of the magnetic target (11a) and the magnetic sensor part (12a). Yes,
    The load sensor according to any one of claims 1 to 5, wherein the magnetic sensor unit (12a) is disposed in the vicinity of a boundary between the adjacent north and south poles.
  7. 　電動モータ（２９）と、その電動モータ（２９）の回転を直動部材（３０）の軸方向移動に変換する運動変換機構（３１）とを有する電動式直動アクチュエータにおいて、
    　前記直動部材（３０）で対象物（２７）を軸方向前方に押圧したときに直動部材（３０）に作用する軸方向後方への反力を受ける部分に、請求項１から６のいずれかに記載の荷重センサを組み込んだことを特徴とする電動式直動アクチュエータ。     In the electric linear actuator having the electric motor (29) and a motion conversion mechanism (31) for converting the rotation of the electric motor (29) into the axial movement of the linear member (30),
    The part according to any one of claims 1 to 6, wherein a portion receiving a reaction force in the axial rearward direction acting on the linear motion member (30) when the object (27) is pressed forward in the axial direction by the linear motion member (30). An electric linear actuator characterized by incorporating a load sensor as described above.
  8. 　前記運動変換機構（３１）は、前記電動モータ（２９）の回転が入力される回転軸（３２）と、その回転軸（３２）の外径面に転がり接触する複数の遊星ローラ（３３）と、その複数の遊星ローラ（３３）を自転可能かつ公転可能に保持するキャリヤ（３４）と、前記複数の遊星ローラ（３３）を囲むように配置された前記直動部材としての外輪部材（３０）と、その外輪部材（３０）の内径面に設けられた螺旋凸条（３９）と、その螺旋凸条（３９）と係合するように前記各遊星ローラ（３３）の外径面に設けられた螺旋溝または円周溝（４０）とを有し、
    　前記弾性部材（２）は、前記キャリヤ（３４）をスラスト軸受（４３）を介して支持することで前記キャリヤ（３４）の軸方向後方への移動を規制する部材である請求項７に記載の電動式直動アクチュエータ。     The motion conversion mechanism (31) includes a rotation shaft (32) to which rotation of the electric motor (29) is input, and a plurality of planetary rollers (33) that are in rolling contact with the outer diameter surface of the rotation shaft (32). A carrier (34) for holding the plurality of planetary rollers (33) so as to be capable of rotating and revolving, and an outer ring member (30) as the linear motion member disposed so as to surround the plurality of planetary rollers (33). A spiral protrusion (39) provided on the inner diameter surface of the outer ring member (30), and an outer diameter surface of each planetary roller (33) so as to engage with the spiral protrusion (39). A spiral groove or circumferential groove (40),
    The said elastic member (2) is a member which controls the movement to the axial direction back of the said carrier (34) by supporting the said carrier (34) via a thrust bearing (43). Electric linear actuator.
  9. 　電動モータ（２９）と、その電動モータ（２９）の回転を直動部材（３０）の軸方向移動に変換する運動変換機構（３１）とを有し、前記直動部材（３０）で摩擦パッド（２７）を軸方向前方に押圧して制動力を発生する電動ブレーキ装置において、
    　前記直動部材（３０）で摩擦パッド（２７）を軸方向前方に押圧したときに直動部材（３０）に作用する軸方向後方への反力を受ける部分に、請求項１から６のいずれかに記載の荷重センサを組み込んだことを特徴とする電動ブレーキ装置。     An electric motor (29) and a motion conversion mechanism (31) that converts the rotation of the electric motor (29) into the axial movement of the linear motion member (30), and the friction pad by the linear motion member (30) In the electric brake device that generates a braking force by pressing (27) axially forward,
    The part according to any one of claims 1 to 6, wherein a portion receiving a reaction force in the axial rearward direction acting on the linear motion member (30) when the friction pad (27) is pressed forward in the axial direction by the linear motion member (30). An electric brake device comprising the load sensor according to claim 1 incorporated therein.
PCT/JP2015/073844 2014-09-02 2015-08-25 Load sensor, electric linear actuator, and electric brake apparatus WO2016035610A1 (en)

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