JP2016097872A - Vehicle friction brake device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle friction brake device in which "drag of a pad" caused by recovery from "heat tilt" is hard to occur.SOLUTION: In this device, a friction member MSB in the vehicle interior side is provided in a manner capable of relative movement against a caliper CRP in an axle direction, and a friction member MSB in the vehicle exterior side is fixed to the caliper CRP. In a state that "heat tilt" that is a phenomenon in which a rotary member KTB is tilting toward the vehicle exterior direction due to temperature rise of the rotary member KTB in a braking state has occurred, when transition from a braking state to an un-braking state is made, the rotary member KTB tries to return to the original shape (solid line → dash line) along with temperature drop of the rotary member KTB. If, in this state, it is determined that it is a state that the friction member MSB in the vehicle interior side is easy to contact to the rotary member KTB, the friction member MSB in the vehicle interior side is moved toward the vehicle interior side so as to make a gap between the friction member MSB in the vehicle interior side and the rotary member KTB be increased (refer to the thick black arrow).SELECTED DRAWING: Figure 5

Description

  The present invention relates to a friction braking device for a vehicle.

  Conventionally, “a disk rotor that rotates with a vehicle wheel”, “a support member that supports the wheel shaft”, “a caliper provided on the support member”, A pair of brake pads provided on the caliper so as to sandwich the disk rotor between the vehicle inner side and the vehicle outer side in the axial direction, and “the axial direction of the wheel according to the operation of the brake pedal by the driver of the vehicle” And a control means for controlling a relative position of the pair of brake pads with respect to the caliper and a pressing force of the pair of brake pads with respect to the disc rotor ”are widely known ( For example, see Patent Document 1). Hereinafter, the “disc rotor” may be referred to as “rotor” and the “brake pad” may be referred to as “pad”.

  When a pair of pads are pressed against the rotor by the driver operating the brake pedal while the vehicle is running (braking state), the temperature of the rotor rises due to friction acting between the pads and the rotor. To do. Depending on the shape of the rotor, when the temperature of the rotor rises, a phenomenon (so-called “heat collapse”) occurs in which the “radially outer portion in contact with the pad” of the rotor is tilted to either the vehicle inner side or the vehicle outer side. easy. Typically, for example, when the rotor has a “hat shape in which the radially inner portion that does not contact the pad protrudes outward in the vehicle direction with respect to the radially outer portion that contacts the pad” “Hot fall” tends to occur.

  When a state in which the brake pedal is not operated (non-braking state) continues after the occurrence of “heat collapse” due to the braking state while the vehicle is traveling, wind (running wind) generated by traveling of the vehicle hits the rotor, The rotor temperature decreases. As the rotor temperature decreases, the rotor tilt angle due to “heat collapse” decreases (recovery from “heat collapse”). By returning from the “heat collapse”, the shape of the rotor can return to a state before the braking state occurs (a state where “heat collapse” has not occurred).

  In this case, in the non-braking state, in the process of recovery from “heat collapse”, the rotor tilts due to the pad on the side where the gap between the pad and the rotor is reduced (ie, “heat collapse”). A phenomenon (so-called “pad dragging”) may occur in which the pad on the opposite side of the direction contacts the rotor.

  In general, a phenomenon (so-called “rotation of the rotor”) in which the radial direction of the rotor slightly deviates from the direction perpendicular to the axis of the wheel inevitably occurs due to an error related to the assembly of the rotor with respect to the wheel shaft. When “pad dragging” occurs while the vehicle is running in a situation where “rotor deflection” occurs, there may be areas where the pad pressing force is large and small in the circumferential direction of the rotor. . In the region where the pressing force is large, the thickness of the rotor is likely to be reduced due to the fact that the friction surface of the rotor is scraped off by contact with the pad compared to the region where the pressing force is small. That is, the problem that the thickness difference of the rotor in the circumferential direction of the rotor becomes large may occur. If the thickness difference of the rotor is large, abnormal noise and vibration are likely to occur in the braking state.

  In addition, when "pad dragging" occurs while the vehicle is running, the frictional torque acting between the pad and the rotor acts as resistance in the rotation of the wheels, resulting in poor vehicle fuel consumption. Problems can also arise.

JP 2005-67247 A

  The present invention has been made to cope with the above-described problem, and an object of the present invention is to provide a friction braking device for a vehicle in which “pad dragging” due to return from “heat collapse” hardly occurs. It is in.

  The vehicle friction braking device according to the present invention includes a "rotating member (KTB) that rotates together with a vehicle wheel", a "supporting member (SJB) that supports the wheel shaft (KTJ)", and "the supporting member ( Caliper (CRP) provided in SJB), and “the rotating member (KTB) is sandwiched between the rotating member (KTB) on the first side and the second side in the axial direction of the wheel” A pair of friction members (MSB) provided on the caliper (CRP), wherein at least the first friction member (MSB) is relatively movable with respect to the caliper (CRP) in the axial direction of the wheel. And the caliper (CRP) of the pair of friction members (MSB) in the axial direction of the wheel according to the operation of the braking operation member (SSB) by the driver of the vehicle. Relative position, and comprises a control means for controlling the pressing force (OAS, SGS) "the relative rotational member (KTB) of the pair of friction members (MSB).

  The friction braking device according to the present invention is characterized in that the first friction member (MSB) is in a non-braking state in which the control means (OAS, SGS) is not operated by the braking operation member (SSB). Based on the determination that the situation is easy to contact the rotating member (KTB), the pair of the pair of friction members (MSB) on the first side and the rotating member (KTB) is increased so that the gap between the first friction member (MSB) and the rotating member (KTB) is increased. The friction member (MSB) is configured to control the relative position of the friction member (MSB) to the caliper (CRP).

  Here, it is preferable that the caliper (CRP) is supported by the support member (SJB) so as to be relatively movable with respect to the support member (SJB) in the axial direction of the wheel. Further, both of the pair of friction members (MSB) may be configured to be movable relative to the caliper (CRP) in the axial direction of the wheel.

  According to the above feature of the present invention, when the “pad drag” due to the first friction member (MSB) is likely to occur due to the return from the “heat collapse”, the first friction member ( The gap between the MSB) and the rotating member (KTB) is increased. Accordingly, “pad dragging” due to the first friction member (MSB) is less likely to occur. As a result, the above-described problem “the rotor thickness difference in the circumferential direction of the rotor increases” and the above-mentioned problem “the vehicle fuel consumption deteriorates” are less likely to occur.

  The “situation in which the first-side friction member (MSB) is easily in contact with the rotating member (KTB)” is, for example, a case where the speed acquired by the speed acquisition means (S1, SGS) for acquiring the vehicle speed is a predetermined speed ( It can be determined based on exceeding sp1).

  When the speed of the vehicle is high, the relative speed of the contact surface between the pad and the rotor is high in the braking state, and therefore the temperature of the rotor is likely to rise. That is, the degree of “heat collapse” tends to increase. In addition, if the non-braking state continues after “heat collapse” occurs, the temperature of the rotor tends to decrease due to strong traveling wind. That is, recovery from a large “heat collapse” is likely to occur. From the above, when the speed of the vehicle is high, it is considered that there is a high possibility that “pad dragging” will occur due to the return from “heat collapse”. The above configuration is based on such knowledge.

  The “situation in which the first friction member (MSB) is easily in contact with the rotating member (KTB)” is acquired by, for example, a temperature acquisition unit (SGS) that acquires the temperature of the rotating member (KTB). It can be determined based on the fact that the temperature of the rotating member (KTB) has dropped below the second threshold value (tm2) lower than the first threshold value (tm1) after exceeding the first threshold value (tm1).

  In the above configuration, “the temperature of the rotating member (KTB) has exceeded the first threshold value (tm1)” can mean that “heat collapse” has occurred. And after that, “the temperature of the rotating member (KTB) has fallen below the second threshold value (tm2)” may mean that a recovery from “heat collapse” has occurred. As described above, according to the above configuration, it is possible to reliably detect a situation in which “pad dragging” due to the first friction member (MSB) is likely to occur due to recovery from “heat collapse”.

  The “situation in which the first-side friction member (MSB) is likely to come into contact with the rotating member (KTB)” is, for example, a pressing force for acquiring the pressing force of the friction member (MSB) against the rotating member (KTB). The determination can also be made directly based on detecting the contact of the first friction member (MSB) with the rotating member (KTB) by the pressing force acquired by the acquiring means (S2).

  In the friction braking device according to the present invention, it is also preferable that when the acquired speed is equal to or less than a predetermined speed, the determination that the situation is not performed is not performed. When the speed of the vehicle is low, the relative speed of the contact surface between the pad and the rotor is low in the braking state. Therefore, it is difficult for the rotor temperature to rise. In addition, the degree to which the friction surface of the rotor is scraped by the pad contact is small. From the above, when the vehicle speed is low, it is less necessary to detect the “situation where the first friction member (MSB) is easily in contact with the rotating member (KTB)”. The above configuration is based on such knowledge. According to the above configuration, it is possible to prevent the “control for increasing the gap between the first friction member (MSB) and the rotating member (KTB)” from being performed unnecessarily.

It is a schematic block diagram for demonstrating the whole embodiment of the friction braking device which concerns on this invention. It is the figure which showed the braking state (no "heat collapse") in embodiment shown in FIG. FIG. 2 is a diagram showing a braking state (with “heat collapse”) in the embodiment shown in FIG. 1. It is the figure which showed the non-braking state (there is "heat fall") in embodiment shown in FIG. FIG. 5 is a diagram showing a state in which a gap between the friction member MSB on the vehicle inner side and the rotating member KTB is increased in the state shown in FIG. 4. It is the time chart which showed an example at the time of detecting "the situation where friction member MSB inside a vehicle is easy to contact rotating member KTB" using vehicle speed. It is the time chart which showed an example at the time of detecting "the situation where the friction member MSB inside a vehicle is easy to contact the rotating member KTB" using the temperature of a rotating member. It is a schematic block diagram for demonstrating the whole modification of the friction braking device which concerns on this invention. It is a figure corresponding to FIG. 2 in the modification shown in FIG. It is a figure corresponding to FIG. 3 in the modification shown in FIG. It is a figure corresponding to FIG. 4 in the modification shown in FIG. It is a figure corresponding to FIG. 5 in the modification shown in FIG.

  Hereinafter, an embodiment (hereinafter referred to as “this embodiment”) of a vehicle friction braking device according to the present invention will be described with reference to the drawings.

(overall structure)
As shown in FIG. 1, the present embodiment includes a rotating member (disc rotor) KTB, a supporting member (mounting bracket) SJB, a slide pin SDP, a caliper CRP, and a pair of friction members (brake pads) MSB. , Pressing means OAS and control means SGS. Note that this embodiment is provided for each wheel of the vehicle.

  The rotating member KTB is fixed to the wheel shaft (axle) KTJ so as to rotate together with the vehicle wheel (at the same rotational speed as the wheel). In the present embodiment, the rotating member KTB has a “hat shape in which a radially inner portion that does not contact the friction member MSB protrudes outward in the vehicle direction with respect to a radially outer portion that contacts the friction member MSB”. doing.

  The support member SJB supports the axle KTJ via a bearing member (bearing, bush, etc., not shown). The support member SJB constitutes a part of the suspension member. The slide pin SDP is fixed to the support member SJB. The slide pin SDP has a pin shape having an axis parallel to the axle KTJ and extending in the vehicle outer direction. Actually, the slide pins SDP extending in the vehicle outer direction are fixed at at least two positions separated from each other along the circumferential direction of the rotating member KTB in the support member SJB.

  The caliper CRP is supported by at least two slide pins SDP so as to be movable relative to the slide pin SDP (support member SJB) in the direction of the axle KTJ (hereinafter also referred to as “axle direction”). The caliper CRP is provided with a pair of friction members MSB so as to sandwich the rotating member KTB inside and outside the vehicle in the axle direction with respect to the rotating member KTB. In the present embodiment, the friction member MSB on the vehicle inner side is provided so as to be movable relative to the caliper CRP in the axle direction, and the friction member MSB on the vehicle outer side is fixed to the caliper CRP.

  The pressing means OAS is built in the caliper CRP. The pressing means OAS includes an electric motor MTB and a conversion mechanism HKK. The conversion mechanism HKK is a mechanism for converting “rotational motion of the rotating shaft of the electric motor (MTB)” into “relative linear motion with respect to the caliper CRP of the friction member MSB inside the vehicle in the axle direction”. Consists of.

  The control means SGS is an electronic control device that controls the rotation angle of the rotation shaft of the electric motor MTB. The control means SGS includes an operation amount sensor SSS that detects an operation amount of a brake operation member (brake pedal) SSB operated by a driver of the vehicle, a wheel speed sensor S1 that detects a rotation speed of the wheel, and a friction member MSB. Information from the pressure sensor S2 for detecting the pressing force on the rotating member KTB can be acquired. The control means SGS estimates the vehicle speed based on the respective information from the wheel speed sensor S1 for each wheel.

  The control means SGS adjusts the rotation angle of the electric motor MTB according to the amount of operation of the braking operation member SSB by the driver based on information from the operation amount sensor SSS. As a result, the relative position of the friction member MSB inside the vehicle with respect to the caliper CRP and the pressing force of the pair of friction members MSB against the rotating member KTB are controlled according to the operation amount of the braking operation member SSB. It has become.

  FIG. 1 shows a state in which the driver does not operate the braking operation member SSB, and therefore the friction member MSB is not in contact with the rotating member KTB. Hereinafter, this state is referred to as a “non-braking state”. FIG. 2 shows a state in which the pair of friction members MSB are in contact with and press the rotating member KTB by the operation of the braking operation member SSB by the driver. Hereinafter, this state is referred to as a “braking state”. In the braking state, the caliper CRP is relatively movable in the axle direction with respect to the slide pin SDP (support member SJB), so that the pressing force (hereinafter simply referred to as “pressing force”) of the pair of friction members MSB against the rotating member KTB. Pressure ") is the same.

  When the braking operation member SSB is operated in the non-braking state, the electric motor MTB is rotated forward. When the electric motor MTB is rotated forward, the friction member MSB on the vehicle inner side moves in the vehicle outer direction (direction approaching the rotation member KTB), and first, the friction member MSB on the vehicle inner side contacts the rotation member KTB. Thereafter, the caliper CRP is moved in the vehicle inner direction by the reaction force received from the friction member MSB on the vehicle inner side, and the friction member MSB on the vehicle outer side is also in contact with the rotating member KTB. That is, the pair of friction members MSB comes into contact with the rotating member KTB. When the electric motor MTB is further rotated forward from this state, “pressing force” (> 0) is generated, and the present embodiment shifts from the non-braking state to the braking state. In the braking state, the “pressing force” increases when the electric motor MTB rotates forward, and the “pressing force” decreases when the electric motor MTB rotates reversely.

  In the braking state, for example, the target pressing force is set based on the detection result of the operation amount sensor SSS, and the output shaft of the electric motor MTB is set so that the actual pressing force obtained from the pressure sensor S2 matches the target pressing force. The rotation angle is controlled by feedback. Alternatively, based on the detection result of the operation amount sensor SSS, “the target rotation angle of the output shaft of the electric motor MTB” or “the rotation member in the conversion mechanism HKK that rotates according to the rotation of the output shaft of the electric motor MTB”. "Target rotation angle" is set, so that "actual rotation angle of the output shaft of the electric motor MTB" or "actual rotation angle of the rotating member in the conversion mechanism HKK" matches the corresponding target rotation angle. The rotation angle of the output shaft of the electric motor MTB is controlled.

  When the operation of the brake operation member SSB is completed in the braking state, the electric motor MTB is rotated in the reverse direction. When the electric motor MTB is rotated in the reverse direction, the friction member MSB on the vehicle inner side moves in the vehicle inner direction (direction away from the rotation member KTB), and the friction member MSB on the vehicle inner side is separated from the rotation member KTB. From this state, the electric motor MTB is further reversely rotated by “predetermined rotation”. As a result, a gap is formed between the friction member MSB inside the vehicle and the rotating member KTB. The formation of this gap makes it difficult for the friction member MSB to come into contact with the rotating member KTB in a non-braking state (so-called “drag”). Note that the time point when the friction member MSB inside the vehicle is separated from the rotating member KTB can be detected based on, for example, that the actual pressing force obtained from the pressure sensor S2 has shifted from a value greater than zero to zero. The “predetermined rotation” may be constant or may vary depending on the vehicle condition.

(Suppression of drag caused by heat fall and recovery from heat fall)
When the vehicle enters the braking state due to the operation of the braking operation member SSB by the driver, the temperature of the rotating member KTB rises due to the friction acting between the friction member MSB and the rotating member KTB. In the present embodiment, as described above, the rotating member KTB has a hat shape in which the radially inner portion that does not contact the friction member MSB protrudes in the vehicle outer direction with respect to the radially outer portion that contacts the friction member MSB. Is included. In the case of this shape, when the temperature of the rotating member KTB rises, as shown in FIG. 3, the “radially outer portion in contact with the friction member MSB” of the rotating member KTB is inclined toward the vehicle outer side (so-called “heat” Fall down ”). At this time, as indicated by a thick white arrow in FIG. 3, the caliper CRP moves toward the vehicle outer side due to “heat collapse”.

  While the vehicle is running, the present embodiment shifts from the braking state to the non-braking state when the operation of the braking operation member SSB ends in a state where the “heat collapse” occurs in the braking state (the state shown in FIG. 3). Then, as shown in FIG. 4, the friction member MSB is separated from the rotating member KTB in a state where the “heat collapse” is maintained (see the solid line in the figure), and as described above, the friction member MSB A gap is formed between the rotary member KTB.

  In the non-braking state shown in FIG. 4, the wind (running wind) generated by the traveling of the vehicle hits the rotating member KTB, so that the temperature of the rotating member KTB decreases. As the temperature of the rotating member KTB decreases, the inclination angle of the rotating member KTB due to “heat collapse” decreases (return from “heat collapse”). As the recovery from “heat collapse” proceeds, the shape of the rotating member KTB can return to the state before the braking state occurs (the state where “heat collapse” has not occurred), as indicated by the broken line in FIG. . At this time, as can be understood from FIG. 4, a phenomenon (so-called “drag”) in which the friction member MSB inside the vehicle comes into contact with the rotating member KTB may occur.

  In general, a phenomenon in which the radial direction of the rotating member KTB slightly deviates from the direction perpendicular to the axle KTJ due to an error related to the assembly of the rotating member KTB with respect to the axle KTJ (so-called “rotation of the rotating member”) is unavoidable. Occur. In the situation where “rotation of the rotating member” occurs, if the “drag” occurs while the vehicle is traveling, a region where the “pressing force” is large and a region where the “pressing force” is large may occur in the circumferential direction of the rotating member KTB . In the region where the “pressing force” is large, the friction surface of the rotating member KTB is scraped by the contact of the friction member MSB, compared to the region where the “pressing force” is small, and thus the thickness of the rotating member KTB is likely to be small. That is, the problem that the thickness difference of the rotating member KTB in the circumferential direction becomes large may occur. If the thickness difference of the rotating member KTB is large, abnormal noise and vibration are likely to occur in the braking state.

  In addition, when the “drag” occurs during traveling of the vehicle, the frictional torque acting between the friction member MSB and the rotating member KTB acts as a resistance in the rotation of the wheels, resulting in poor fuel consumption of the vehicle. The problem of becoming may also occur.

  Therefore, in the present embodiment, it is determined whether or not a “situation where the friction member MSB inside the vehicle is easily in contact with the rotating member KTB” (hereinafter referred to as “contact situation”) occurs in the non-braking state. . A specific method for detecting the “contact state” will be described later.

  In the present embodiment, when the “contact state” is detected, the friction member MSB on the vehicle inner side is moved in the vehicle inner direction by a “predetermined amount” as indicated by a thick black arrow in FIG. As a result, even if the shape of the rotating member KTB returns to the state before the occurrence of the braking state (the state where the “heat collapse” has not occurred) due to the progress of the return from the “heat collapse”, FIG. As can be seen, the friction member MSB inside the vehicle does not come into contact with the rotating member KTB. That is, the “drag” does not occur. The “predetermined amount” may be constant or may vary depending on the vehicle condition.

  According to the present embodiment, when “dragging” by the friction member MSB inside the vehicle is likely to occur due to the return from “heat collapse”, the clearance between the friction member MSB inside the vehicle and the rotation member KTB is large. Is done. Therefore, “dragging” due to the friction member MSB inside the vehicle is less likely to occur. As a result, the above-described problem “the thickness difference of the rotating member KTB in the circumferential direction is large” and the above-mentioned problem “the vehicle fuel efficiency is poor” are less likely to occur.

(Contact status detection method)
Hereinafter, a specific method for detecting the “contact state” will be described.

<Detection using vehicle speed>
The “contact state” can be detected based on the fact that the vehicle speed estimated by the control means SGS exceeds the first speed sp1 as described above. Specifically, when the vehicle speed changes as shown in FIG. 6, the “contact situation” is detected at time t <b> 1 when the vehicle speed passes while increasing the first speed sp <b> 1.

  In the example shown in FIG. 6, in the non-braking state, the gap between the pair of friction members MSB (hereinafter, also simply referred to as “gap”) is adjusted to cl1 before time t1. When the “contact situation” is detected at time t1, the friction member MSB on the vehicle inner side is moved in the vehicle inner direction. As a result, immediately after the time t1, the “gap” increases from cl1 to cl2. In this example, after time t1, it is determined that the “detection situation” has disappeared at time t2 when the vehicle speed passes while decreasing the second speed sp2, which is smaller than the first speed sp1, and the “gap” is determined. It is returned from cl2 to cl1.

  Generally, when the vehicle speed is high, the relative speed of the contact surface between the friction member MSB and the rotating member KTB is high in the braking state, and therefore the temperature of the rotating member KTB is likely to rise. That is, the degree of “heat collapse” tends to increase. In addition, if the non-braking state continues after the “heat collapse” occurs, the temperature of the rotating member KTB tends to decrease due to the strong traveling wind. That is, recovery from a large “heat collapse” is likely to occur. From the above, it is considered that when the vehicle speed is high, there is a high possibility that the “drag” will occur due to the return from “heat collapse”. <Detection using vehicle speed> described above is based on such knowledge.

<Detection using temperature of rotating member>
The “contact state” can be detected based on the fact that the temperature of the rotating member KTB acquired by the control means SGS has dropped below the second temperature tm2 lower than the first temperature tm1 after exceeding the first temperature tm1. The temperature of the rotating member KTB can be estimated based on, for example, the transition of the operation amount of the braking operation member SSB up to the present and the transition of the vehicle speed, and the sensor that directly detects the temperature of the rotating member KTB. Can be detected based on the detection result.

  Specifically, it is assumed that the temperature of the rotating member KTB changes as shown in FIG. In the example shown in FIG. 7, while the vehicle is running, the temperature of the rotating member KTB rises by continuing the braking state from the start time of the time chart to time t1, and then from time t1 to time t2. The temperature of the rotating member KTB is reduced by continuing the non-braking state over a period of time. In this example, the “contact state” is detected at time t1 when the temperature of the rotating member KTB exceeds the first temperature tm1 and then falls below the second temperature tm2.

  In the example illustrated in FIG. 7, the “gap” is adjusted to cl1 before time t1. When the “contact situation” is detected at time t1, the friction member MSB on the vehicle inner side is moved in the vehicle inner direction. As a result, immediately after the time t1, the “gap” increases from cl1 to cl2. In this example, in the state where the non-braking state after time t1 is continuing, it is determined that the “detection situation” has disappeared at time t2 when the braking state is started again, and the “gap” is changed from cl2. It is returned to cl1. At time t2, due to the transition from the non-braking state to the braking state, the temperature of the rotational speed KTB has changed from decreasing to increasing.

  The disappearance of the “detection status” may be determined based on the fact that a predetermined time has elapsed since the time when the “contact status” was detected (time t1 in FIG. 7). The determination may be made based on the fact that the vehicle speed has passed while decreasing the predetermined speed after the time point when the “contact situation” is detected (time t1 in FIG. 7).

  “The temperature of the rotating member KTB has exceeded the first temperature tm1” can mean that “heat collapse” has occurred. After that, “the temperature of the rotating member KTB has fallen below the second temperature tm2” can mean that the recovery from “heat collapse” has occurred. From the above, according to the above-described <detection using the temperature of the rotating member>, it is possible to reliably detect a situation in which the above-mentioned “drag” due to the friction member MSB inside the vehicle is likely to occur due to the return from “heat collapse”. Can be done.

<Detection using "pressing force">
The “contact state” can be directly detected based on detecting “contact of the friction member MSB on the vehicle inner side with the rotating member KTB” using the “pressing force” acquired by the pressure sensor S2. . The “contact of the friction member MSB inside the vehicle with the rotating member KTB” can be detected based on, for example, that the actual pressing force obtained from the pressure sensor S2 has shifted from zero to a value greater than zero. Therefore, for example, in the non-braking state, the “contact state” is detected at the time when the actual pressing force obtained from the pressure sensor S2 shifts from zero to a value greater than zero.

  In addition, when the vehicle speed is equal to or lower than the “predetermined speed”, the “contact state” may be configured not to be detected. This is based on the following reason. That is, when the vehicle speed is low, the relative speed of the contact surface between the friction member MSB and the rotating member KTB is low in the braking state. Therefore, it is difficult for the temperature of the rotating member KTB to rise. In addition, the degree to which the friction surface of the rotating member KTB is scraped by the contact of the friction member MSB is small. From the above, when the vehicle speed is low, the necessity of detecting the “contact state” is low. The above configuration is based on such knowledge. According to the above configuration, it is possible to prevent the “control for increasing the gap between the friction member MSB and the rotation member KTB inside the vehicle” from being performed unnecessarily. The “predetermined speed” can be set to a value lower than the second speed sp2 shown in FIG. 6, for example.

(Modification)
In the present embodiment, the rotating member KTB has a “shape that causes a“ heat collapse ”that tilts toward the outside of the vehicle”, and the friction member MSB on the inside of the vehicle can move relative to the caliper CRP in the axle direction. The friction member MSB on the outside of the vehicle is fixed to the caliper CRP, but the rotating member KTB has a “shape that causes“ heat collapse ”that is inclined toward the inside of the vehicle” and the friction on the outside of the vehicle. The member MSB may be provided so as to be movable relative to the caliper CRP in the axle direction, and the friction member MSB inside the vehicle may be fixed to the caliper CRP. In this case, when the “contact state” is detected, the friction member MSB outside the vehicle is moved in the vehicle outside direction (direction away from the rotating member KTB) by a “predetermined amount”.

  Further, as shown in FIGS. 8 to 12 corresponding to FIGS. 1 to 5, the pair of friction members MSB may be provided so as to be relatively movable with respect to the caliper CRP in the axle direction. Also in this case, as in the present embodiment (see FIG. 5), when the “contact state” is detected, the friction member MSB on the vehicle inner side is only “predetermined amount” as shown by the thick black arrow in FIG. It is moved in the vehicle inner direction (direction away from the rotating member KTB).

  Further, in the configuration in which the pair of friction members MSB are provided so as to be relatively movable with respect to the caliper CRP in the axle direction (see FIG. 8), when the “contact state” is detected, the “heat” of the rotary member KTB is detected. As the return from the “falling” progresses, the distance between the pair of friction members MSB is maintained constant (for example, in the above-described FIGS. 6 and 7, the “gap” is maintained at cl1), and the vehicle interior The friction member MSB may be gradually moved in the vehicle inner direction (direction moving away from the rotation member KTB), and the friction member MSB on the vehicle outer side may be gradually moved in the vehicle inner direction (direction approaching the rotation member KTB).

  In the present embodiment and the above-described modification, when the “contact state” is detected, the interval between the pair of friction members MSB is widened (for example, in FIG. 6 and FIG. 7 described above, the “gap” is cl1. In this configuration, the distance between the pair of friction members MSB is kept constant (not widened). Therefore, when the operation of the braking operation member SSB is subsequently performed, the response time from the start of the operation to the occurrence of “pressing force (> 0)” is shortened. That is, responsiveness at the time of braking operation is improved while suppressing “drag” due to return from “heat fall”. In the configuration in which the pair of friction members MSB are both provided to be movable relative to the caliper CRP in the axle direction (see FIG. 8), the caliper CRP may be fixed to the support member SJB (support). It may not be supported so as to be movable relative to the member SJB in the axle direction).

  In the present embodiment, the relative position in the axle direction of the friction member MSB with respect to the caliper CRP and the “pressing force” using the driving force of the electric motor MTB controlled according to the operation of the braking operation member SSB. However, the relative position in the axle direction of the friction member MSB with respect to the caliper CRP and the “pressing force” are adjusted by using the hydraulic pressure generated in response to the operation of the braking operation member SSB (well-known One of the configurations may be employed.

  In this case, when shifting from the braking state to the non-braking state, the hydraulic pressure is not reduced to atmospheric pressure, but is maintained at “a predetermined pressure higher than atmospheric pressure”. Thereby, the “gap” between the friction member MSB and the rotating member KTB is adjusted and maintained at a relatively small value (a value corresponding to cl1 in FIGS. 6 and 7 described above). In this state, when the “contact state” is detected, the hydraulic pressure is reduced to atmospheric pressure. As a result, the “gap” is expanded from the relatively small value to a relatively large value (a value corresponding to cl2 in FIGS. 6 and 7 described above).

  KTB: rotating member, SJB: supporting member, CRP: caliper, MSB: friction member, OAS ... pressing means, SGS ... control means, MTB ... electric motor, HKK ... conversion mechanism

Claims (6)

A rotating member that rotates with the wheels of the vehicle;
A support member for supporting the wheel shaft;
A caliper provided on the support member;
A pair of friction members provided on the caliper so as to sandwich the rotating member on the first side and the second side in the axial direction of the wheel with respect to the rotating member, and at least the friction on the first side A pair of friction members that are movable relative to the caliper in the axial direction of the wheel;
The relative position of the pair of friction members with respect to the caliper in the axial direction of the wheel and the pressing force of the pair of friction members with respect to the rotating member are controlled according to the operation of the braking operation member by the driver of the vehicle. Control means;
With
The control means includes
In a non-braking state where the operation of the braking operation member is not performed, the first friction member and the first friction member are determined based on the determination that the first friction member is in contact with the rotating member. A friction braking device for a vehicle configured to control a relative position of the pair of friction members with respect to the caliper so that a gap with a rotating member is increased. The friction braking device for a vehicle according to claim 1,
The control means includes
Comprising speed acquisition means for acquiring the speed of the vehicle;
A friction braking device for a vehicle configured to determine the situation based on the acquired speed exceeding a predetermined speed. The friction braking device for a vehicle according to claim 1,
The control means includes
Temperature acquisition means for acquiring the temperature of the rotating member;
The acquired temperature of the rotating member is configured to determine the situation based on the fact that the temperature is below a second threshold value that is lower than the first threshold value after exceeding a first threshold value. A friction braking device for a vehicle. The friction braking device for a vehicle according to claim 1,
The control means includes
A pressing force acquisition means for acquiring a pressing force of the friction member against the rotating member;
A friction braking device for a vehicle configured to determine the situation based on detecting contact of the first friction member with the rotating member by the acquired pressing force. The friction braking device for a vehicle according to any one of claims 1, 3, and 4,
The control means includes
Comprising speed acquisition means for acquiring the speed of the vehicle;
A friction braking device for a vehicle configured not to determine that the situation is present when the acquired speed is equal to or lower than a predetermined speed. The friction braking device for a vehicle according to any one of claims 1 to 5,
The control means includes
An electric motor;
A conversion mechanism that converts the rotational motion of the rotating shaft of the electric motor into a linear motion relative to the caliper of the friction member in the axial direction of the vehicle,
By controlling the rotation angle of the rotating shaft of the electric motor, the relative position of the pair of friction members with respect to the caliper and the pressing force of the pair of friction members with respect to the rotation member are controlled. A friction braking device for a vehicle.

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