JP4225195B2 - Judder generator and judder measurement system - Google Patents

Description

  The present invention relates to a judder generator and a judder measurement system, and more particularly to a judder generator that can easily generate a judder generated when a brake of a vehicle is operated, and a vehicle using the judder generator. The present invention relates to a judder measurement system that can easily measure judder in the field.

  Usually, a vehicle such as an automobile is equipped with a disc brake or a drum brake as a braking means so that appropriate vehicle braking can be obtained at a desired timing.

  When a disc brake or a drum brake of a vehicle is operated, vibration in the rotational direction of the tire called rattling may occur in the brake device. This vibration phenomenon is called judder and does not greatly affect the braking characteristics of the vehicle, but is one factor that gives the passenger a sense of discomfort during braking. In today's vehicles where smooth driving performance is required, such judder is required to be suppressed and preferably eliminated.

  For example, in the case of a disc brake, the cause of judder is uneven wear of the rotor constituting the brake device. For example, as the traveling distance of the vehicle increases, even if the rotor and caliper are assembled with high accuracy, as a phenomenon during traveling, as shown in FIG. A phenomenon may occur in which the pad 104 is not fully returned after being pressed against the rotor 100. As a result, a phenomenon occurs in which the pad 104 comes into contact with the rotor 100 at one point during rotation of the rotor 100, and only that portion is shaved as shown in FIG. 7B, and the rotor 100 is thick. A part and a thin part are made. That is, the unevenly worn rotor 100a is formed.

  When the brake is applied with such a rotor 100a, the brake is effective in the thick portion of the rotor 100a as shown in FIG. 7C, and is not so effective in the thin portion as shown in FIG. 7D. As a result, as shown in FIG. 7 (e), the state in which the brake is strongly effective and the state in which the brake is weak are repeated at a high speed, and the vibration is generated in the brake device and transmitted to each part of the vehicle. Such vibrations are perceived by the occupant as being uncomfortable, but since the steady portion of the braking force becomes the braking force of the entire brake, the vehicle braking force can be sufficiently secured.

  The same applies to drum brakes. When the travel distance increases, the center of rotation of the drum shifts or the shoe returns poorly, or the drum mounting accuracy is insufficient and the drum rotates eccentrically. In such a case, the shoe contact surface of the drum is partially scraped, and like the disc brake, the state where the brake is strong and the state where the brake is weak is repeated at high speed, and the brake device vibrates, causing each part of the vehicle to It will be transmitted.

  Conventionally, as a method of analyzing such judder, there has been a method of measuring the frequency, direction, magnitude, phase, etc. of vibration by using a dynamometer with a single brake unit or unit. Similarly, there has been proposed a test apparatus for performing a test by generating judder with a single brake apparatus. This test apparatus incorporates a brake device into a dynamometer through a vibration system equivalent to that of an actual vehicle, and performs measurement related to vibration (see, for example, Patent Document 1).

Japanese Examined Patent Publication No. 4-57210

  However, in the test apparatus described above, in order to generate judder in the brake device, it is necessary to create a plurality of types of rotors with uneven wear as described above, and it is necessary to replace the rotor for each test. At the same time, there is a problem that the cost for producing the test rotor increases.

  Furthermore, the test described above is a test of the brake device alone, and does not simulate judder recognized by a passenger occurring in an actual vehicle. Since the passenger feels judder through the steering, the seat, the floor, etc., the data obtained by the test of the brake device alone is insufficient as judder analysis data for improving the quality of the vehicle.

  On the other hand, as shown in FIG. 7B, a method is also conceivable in which an unevenly worn rotor is attached to an actual vehicle, the vehicle is actually traveled, and vibration data recognized by the occupant is obtained by sensors installed in various parts of the vehicle. However, in this case as well, it is necessary to replace the unevenly worn rotor for each test in the same manner as described above, and the test preparation becomes complicated, and it is difficult to say that the test is easy. Furthermore, when the vehicle is actually driven, a composite vibration in which various vibrations such as vibrations other than the brake judder, for example, unevenness of the road surface to be driven and vibration generated by the engine during actual driving are combined is arranged on the steering wheel and the seat. It will be detected by the sensor. That is, when the vehicle is actually run, there is a problem that disturbances other than the brake judder are large, and the brake judder cannot be analyzed accurately. Further, when the vehicle is actually run, it is impossible to directly observe or touch what kind of vibration is actually generated in the brake device or in the vicinity thereof.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a judder generator capable of easily and simply generating judder of various patterns. In addition, a brake judder measurement system that can easily perform vibration analysis based on brake judder in a vehicle in a state in which the influence of disturbance vibration other than brake judder is suppressed, that is, in the state of not actually running, using the judder generator is provided. The purpose is to do.

  The present invention is a judder generator for simulating and generating judder associated with a brake operation in a brake device that brakes the rotating body by pressing a friction body supported by a support against a rotating body that rotates together with a tire, A vibration generating unit that is disposed between the rotating body and the support and applies vibrations in a tangential direction of a rotation axis of the rotating body to the rotating body and the support, and vibrates the vibration generating unit at a predetermined cycle. And a vibration control unit.

  Here, the vibration generating unit may be arbitrarily selected as long as it is a means that can easily change the control amount capable of obtaining a vibration stroke, such as a hydraulic actuator (hydraulic cylinder), an electromagnetic actuator, a piezoelectric element, or the like. it can. Similarly, a vibration stroke can be obtained by rotating an eccentric cam or the like using a motor.

  According to this configuration, vibration can be easily and periodically applied between the rotating body and the support body, and the brake judder can be easily simulated.

  The brake device is a disc brake device, the rotating body is a rotor, the support body is a caliper, and the vibration generating unit applies an excitation force to the caliper, and It can be set as the structure fixed so that the reaction force generated sometimes may be made to act. Further, the brake device is a drum brake device, the rotating body is a drum, the support body is a backing plate, the vibration generating unit applies an excitation force to the backing plate, and the drum The reaction force generated at that time may be fixed so as to act.

  In this case, a disc brake or drum brake judder can be easily simulated.

  Further, in the above configuration, the vibration control unit can arbitrarily change a vibration characteristic to be generated.

  According to this configuration, it is possible to easily generate judder of various patterns only by changing the vibration characteristics in the vibration control unit, for example, the vibration cycle.

  The judder generating device of the present invention further includes a tire holding portion for holding a tire, and the tire holding portion is free from movement in the rotation direction and the steering direction of the tire while suppressing translation of the tire in the front-rear and left-right directions. It is characterized by holding in a state.

  In an actual vehicle, brake judder occurs when the vehicle is traveling at a relatively high speed on a highway or the like, but when the vehicle is traveling at a high speed, the resistance that the tire receives from the road surface decreases. In this state, the brake operates and judder occurs. Therefore, when generating a simulated judder, it is preferable that the restraining force from the tire contact surface can be reduced. The tire holding part holds the movement of the tire in the rotation direction and the steering direction in a free state while suppressing the front / rear / left / right translation of the tire, so that the vehicle travels judder that is generated while the vehicle is actually running. Therefore, it is possible to easily simulate in a state where the operation is not performed, and it is possible to generate judder with high reliability.

  Moreover, the said structure WHEREIN: The said tire holding part has a load provision part which provides a predetermined load to the front-back direction of a tire, It is characterized by the above-mentioned.

  As described above, the resistance received by the tire from the ground surface during high-speed running is reduced, but the restraining force received by the tire when the brake device is operated hard (rapid braking) and when it is operated weakly (normal braking). (Resistance) changes. In the case of sudden braking, the tire receives a large force in the direction opposite to the traveling direction. In the case of normal braking, it receives a weaker force than in the case of sudden braking. Therefore, by applying a load in the front-rear direction of the tire, it is possible to easily simulate judder when the operating state of the brake device changes.

  Moreover, the judder measurement system using the judder generator of the said structure can be comprised. That is, the judder measurement system includes a vehicle on which the judder generator is mounted on at least one wheel, a sensor that is disposed at a predetermined position of the vehicle and that measures vibration, and a vibration analysis unit that analyzes vibration measured by the sensor. , Including.

  Here, the sensor for measuring vibration is, for example, any position such as a steering wheel, floor, seat, etc., in which the passenger directly recognizes vibration, gear box, tie rod, lower arm, knuckle arm, etc. to which vibration from the brake device is transmitted. It is. Further, the vehicle may be any vehicle that does not substantially move by the tire holding portion. If a judder generator is mounted, it is desirable to use a vehicle having a traveling function.

  According to this configuration, the simulated vibration generated by the judder generator is transmitted to each part of the vehicle, and the sensor can measure the vibration at that location. Moreover, based on the measured vibration, vibration analysis of the entire vehicle can be performed in a non-running state.

  Further, in the above configuration, the judder generator generates judder at least two wheels simultaneously.

  In a four-wheeled vehicle, a brake device is disposed on each wheel and brakes the vehicle while being associated with each other. At this time, judder may occur individually. And the judder generated in each part reaches the position where the sensors such as the steering and the seat are arranged, and is measured. Therefore, it is possible to simulate the judder desired to be realized by arbitrarily generating the judder generated in each wheel.

  At this time, the judder generator arranged on each wheel can be used for both the disc brake and the drum brake.

  For example, a disc brake judder generator can be arranged on the front wheel side, and a drum brake judder generator can be arranged on the rear wheel side. The reverse is also possible. According to this configuration, it is possible to simulate a judder that is closer to actual running.

  Hereinafter, embodiments of the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

  FIG. 1 shows a schematic configuration diagram of a judder measurement system 10 that measures the judder (vibration accompanying the brake operation) of the present embodiment in a simulated manner. The vehicle 12 is structurally a vehicle having an actual traveling function, and is required for the vehicle, and includes a drive source such as an engine (not shown), a drive transmission system such as a clutch, a transmission, and a differential, a suspension, a steering 14 and a seat. In addition to this, it is desirable to include components mounted on a normal vehicle. Although the brake device will be described later, the structure is such that judder is simulated instead of being processed and not capable of actual braking. A tire 16 that can actually run is mounted. In FIG. 1, the front portion of the vehicle 12 is shown in a simplified manner.

  The tire 16 is supported by a tire holding portion 18 that holds the movement in the rotational direction and the steering direction in a free state while suppressing translation in the front-rear and left-right directions. Although the specific structure will be described later, the tire 16 of the vehicle 12 is supported by the tire holding portion 18 on all four wheels and is in a state of floating from the ground contact surface.

  A brake device is built in the wheel on which the tire 16 is mounted. The judder generator of this embodiment is configured using a part of this brake device. That is, the vibration generating unit 20 is attached to the brake device, and the vibration control unit 22 generates vibration at a predetermined period.

  In addition, sensors 24 that measure vibrations based on judder generated by the brake device are disposed at various parts of the vehicle 12, for example, the steering 14 and the floor of the vehicle 12. The measured vibration is supplied to the vibration analysis unit 26, where appropriate analysis processing, raw data display processing, and the like are performed. In addition, the sensor 24 may be any position such as a seat, a shift lever, a body, etc. that can be directly touched by a passenger, a gear box that transmits vibrations from a brake device, a tie rod, a lower arm, a knuckle arm, etc. Can be placed in position. In addition to a sensor for measuring vibration, for example, a temperature sensor or the like may be arranged to measure environmental data when judder is generated and analyze the relationship with vibration.

  FIG. 2 shows a schematic configuration diagram of the judder generator 28 mounted on the judder measurement system 10 of the present embodiment. FIG. 2 shows a judder generator 28 for a disc brake as an example. As is well known, the disc brake is a caliper as a support that supports a rotor 30 that rotates together with a tire (disc wheel) and a pad that is pressed against the rotor 30 via a hydraulic cylinder or the like and performs a braking operation. 32.

  In the case of a disc brake, a pad supported by a caliper is pressed against the side of the rotor. At this time, the rotating rotor exerts an acting force on the caliper through the pressed pad. At the same time, a reaction force is generated in the rotor, and the rotor is stopped by the reaction force. In other words, the tire stops. When the rotor is unevenly worn as shown in FIG. 7B, when the pad is pressed against the rotor and braking is applied, the acting force and the reaction force acting between the rotor and the caliper are, as described above. Switching between working large and small works at high speed. As a result, tangential vibration of the rotor, that is, judder occurs.

  The configuration shown in FIG. 2 is configured to reproduce the phenomenon at this time in a pseudo manner. Specifically, a notch 30a is formed in a part of the rotor 30, and a hydraulic actuator (hydraulic cylinder) 34, for example, is fixed as a vibration generating unit 20 by a fixing means such as a bolt 36. At this time, the cylinder end portion 34a of the hydraulic actuator 34 is fixed so as to come into contact with the standing surface of the notch 30a. On the other hand, the end of the piston rod 34b of the hydraulic actuator 34 is disposed so as to contact a flat plate 38 disposed at a position where the pad is to be fixed in the caliper 32. A hydraulic drive unit 40 is connected to the hydraulic actuator 34 fixed in this manner, the pressure state of the piston rod 34b is changed by the control of the vibration control unit 22, and the rotor 30 and the caliper 32 move relatively. The vibration in the tangential direction of the rotor 30 is generated.

  For example, as shown in FIG. 7C, the braking force increases when the pad presses the thick portion of the rotor. That is, a large force acts between the rotor 30 and the caliper 32. In this state, in the configuration of FIG. 2, the hydraulic actuator 34 is pressurized and the piston rod 34b protrudes to supply a large acting force as a caliper input, and the rotor 30 is strongly pushed back (rotor input) as a reaction. Can be reproduced.

  On the other hand, as shown in FIG. 7D, when the pad presses a portion with a small thickness of the rotor, the braking force is reduced. That is, the force acting between the rotor 30 and the caliper 32 is reduced. In this state, in the configuration shown in FIG. 2, the pressurizing operation of the hydraulic actuator 34 is reduced, the caliper input (acting force) by the piston rod 34b is reduced, and as a reaction, the force pushing the rotor 30 (rotor input) is reduced. Can be reproduced.

  By periodically switching the applied pressure of the hydraulic actuator 34 as described above, the acting force and the reaction force acting between the rotor 30 and the caliper 32 fluctuate at high speed, and the rotor that is actually unevenly worn by the pad. The vibration in the tangential direction of the rotor 30 is generated in the same way as when trying to brake the rotor.

  At this time, the pressurization cycle of the hydraulic actuator 34 is a cycle in which the vibration control unit 22 controls the hydraulic drive unit 40, and the cycle is, for example, a cycle as shown in FIG. As described above, when braking is applied by the brake device, the rotor speed gradually decreases. That is, in the actual case, the cycle of pressing the thick part and the thin part of the rotor where the pad is partially worn becomes gradually longer. Therefore, as shown in FIG. 3, by controlling the hydraulic actuator 34 so that the pressurization period is gradually extended, vibration similar to that of an actual judder can be simulated. The cycle at this time is preferably matched to the rotation cycle of the tire during actual running of the vehicle. The period T can be obtained by (effective tire rolling radius × 2π) / vehicle speed.

  For example, when the effective rolling radius of the tire is 0.25 m and the maximum vehicle speed during measurement brake operation is 200 km / h, the cycle T is 0.02827 s (about 35 Hz), and during measurement brake operation When the minimum speed is 30 km / h, the period T is 0.1885 s (about 5 Hz). Therefore, if the control frequency by the vibration control unit 22 is changed, for example, between 35 Hz and 5 Hz, the judder generated during the actual brake operation can be simulated by the judder generator 28 of FIG. Note that the variation in FIG. 3 corresponds to a periodic change in braking force (braking force) caused by the difference in thickness of the rotor 30. In FIG. 3, a sin wave is shown as an example of a waveform. However, a waveform having an arbitrary shape such as a triangular wave or a square wave can be appropriately selected according to the surface state of the rotor to be simulated. Further, when measuring a vibration mode at a specific frequency, vibration can be applied at a constant period.

  In FIG. 2, for example, a strain gauge 22 a is attached to the piston rod 34 b as a detection means for monitoring the operation state of the hydraulic actuator 34 and feeding back to the vibration control unit 22. It is reflected. As a result, a judder with a desired braking force is simulated well.

  FIG. 4 schematically shows the configuration of the tire holding portion 18 that can hold the tire 16 in a floating state. 4A is a front view, FIG. 4B is a right side view, and FIG. 4C is a top view.

  As described above, when the vehicle 12 is traveling, the restraining force (resistance) received from the ground contact surface decreases as the speed increases. Therefore, in order to form a state as if the vehicle 12 is stationary while the vehicle 12 is stationary, it is necessary to prevent the tire 16 from being restrained by the ground contact surface.

  In the tire holding portion 18, four support posts 44 (only two of the front support posts 44a and 44b are shown in FIG. 4A) are fixed to the base plate 42. As shown in FIG. , 44b is extended over the stay 46a. Similarly, a stay 46b is stretched over the columns 44c and 44d. Further, two wires 48 are lowered from the stays 46a and 46b, respectively, and a support plate 50 that actually mounts and supports the tire 16 is suspended at four points. The surface of the support plate 50 is subjected to knurling or the like so that translation of the mounted tire 16 in the front-rear and left-right directions is suppressed.

  The brake device tire 16 to which the judder generator 28 described above is attached is placed on the support plate 50 of the tire holder 18 so that the support plate 50 is supported by the wire 48 while suppressing the front-rear and left-right translation of the tire 16. Since it is suspended like a swing, the movement of the tire 16 in the rotational direction and the steering direction can be made free. That is, even when the translation of the tire 16 of the vehicle 12 is suppressed by supporting the tire 16 with the floating type tire holding portion 18, the state is close to a running state in which the restraining force (resistance) from the ground contact surface is reduced. It becomes possible to simulate the occurrence of judder.

  By the way, when the brake device is actually operated, a force that is pushed from the front in the traveling direction for stopping the tire 16 acts on the tire 16. That is, it receives a force pushed backward from the contact surface at the contact position of the tire 16. The force received at this time varies depending on how the brake device is operated. That is, when the brake device is operated strongly in an attempt to decelerate rapidly (when the brake pedal is pressed hard and sudden braking is applied), a large force is applied to the tire 16. On the other hand, when the vehicle operates weakly (when the brake pedal is depressed as usual), the force applied to the tire 16 is smaller than that in the case of sudden braking. Therefore, in order to more accurately simulate judder, it is necessary to simulate a difference depending on how the brake device is operated. That is, it is necessary to arbitrarily change the restraining force from the ground plane.

  Therefore, the tire holding portion 18 of the present embodiment is provided with a load block 52 on the back surface of the support plate 50 (the back surface side of the contact portion between the tire 16 and the support plate 50). For example, the load block 52 may be fixed with a bolt 54 or the like, or may be integrally formed with the support plate 50. On the other hand, a support block 58 that supports a load rod 56 that presses the load block 52 as a weight applying portion is fixed to a part of the base plate 42. For example, the support block 58 may be fixed by a bolt 60 or the like, or may be integrally formed with the base plate 42. A screw portion 56 a is formed in a part of the load rod 56, and is screwed into a screw hole portion formed in the support block 58. Therefore, if the load rod 56 is rotated and moved backward (rightward in FIG. 4A), the load block 52 is brought into a non-contact state, and the support plate 50 is maintained in the free state as described above. On the other hand, if the load rod 56 is rotated and advanced (leftward in FIG. 4A), the load block 52 is brought into contact with or pressed, and the support plate 50 receives a predetermined resistance force from the grounding surface. It is possible to form the same state as that in which the resistance corresponding to the operating force of the brake device is received from the ground contact surface.

  Therefore, by easily adjusting the amount of advancement / retraction of the load rod 56, it becomes possible to simulate a change in the restraining force on the vehicle due to a difference in the operation of the brake device, and the state at the time of occurrence of judder can be reproduced more faithfully. It becomes possible.

  Thus, the judder generated by the judder generator 28 with the tire holding portion 18 supporting the tire 16 can simulate the judder generated in the vehicle 12 during actual travel in a non-running state. In the judder simulation, as described above, the operation cycle of the hydraulic actuator 34 provided by the vibration control unit 22 is changed, or the amount of advancement / retraction of the load rod 56 of the tire holding unit 18 is changed as appropriate. The judder in the state can be easily obtained and measured without actually running the vehicle 12. Further, since it is possible to generate various patterns of judder simply by changing the operation cycle of the hydraulic actuator 34 and the advance / retreat amount of the load rod 56, the uneven wear rotor can be provided for each judder pattern as in the prior art. Therefore, it is not necessary to create a new judder or replace it for each measurement, and it is possible to easily perform efficient judder measurement at low cost. Further, since the vehicle 12 does not actually travel, it becomes possible to easily approach the judder generation site, and the behavior of the rotor 30 and the caliper 32 at the time of the judder generation, the suspension existing in the vicinity thereof is observed, or as necessary. Thus, it is possible to easily touch the directly vibrating part, and to increase the judgment factors of judder analysis. Furthermore, since the vehicle 12 does not need to actually travel, the vehicle 12 is not affected by changes in weather and road conditions, vibrations caused by the state of the tire 16, and other engine vibrations during traveling. Therefore, it is possible to accurately measure and analyze judder caused by brake operation. Of course, since the vehicle 12 is actually used, the vibration of the vehicle 12 as a whole can be simulated, measured, and analyzed. In the actual measurement, the engine may be driven in an idling state. However, since the vibration during idling is slight and known as a constant vibration pattern, it can be easily canceled. So it will not affect judder measurement.

  FIG. 5 shows a schematic configuration diagram of the judder generator 62 for the drum brake. The drum brake presses a pair of brake shoes arranged on the inner side of the brake drum 64 against the inner surface of the brake drum 64, and brakes the brake drum 64, that is, the tire by the frictional force generated at that time. The brake shoe is supported by a wheel cylinder fixed to a backing plate that forms one side of the brake drum 64, and has a structure in which the brake shoe is pressed against the inner surface of the brake drum by the operation of the wheel cylinder.

  Therefore, when the judder generator 62 is formed by the drum brake, the brake drum 64 as a rotating body that rotates together with the tire (disc wheel), and the brake drum 64 via the wheel cylinder, as in the case of the disc brake of FIG. A backing plate (only an anchor portion 66 formed on the backing plate is shown in FIG. 5) is used as a support for supporting a brake shoe that is pressed against the inner surface and performs a braking operation.

  As described above, in the case of the drum brake, the brake shoe supported by the backing plate is pressed against the inner surface of the brake drum 64. At this time, the rotating brake drum 64 exerts an acting force on the backing plate (anchor portion 66 in FIG. 5) via the pressed brake shoe. At the same time, a reaction force is generated in the brake drum 64, and the brake drum 64 stops due to the reaction force.

  Here, in the drum brake, the cause of judder is that, like the disc brake, as the travel distance increases, the brake drum rotates eccentrically for some reason, or the return of the brake shoe becomes dull, This is caused by partially scraping the inner surface of the brake drum. That is, a portion where the surface in contact with the brake shoe is partially distant is generated due to the shaving of the inner surface. As a result, as in the case of the disc brake, a state where the braking force is large and a state where the braking force is small are repeated at a high speed, and the tangential vibration, that is, judder is generated in the brake drum. In addition, the same phenomenon occurs when the brake drum is originally attached at an eccentric position or is attached in a deformed state.

  The configuration shown in FIG. 5 is configured to reproduce the phenomenon at this time in a pseudo manner. Specifically, a notch 64 a is formed in a part of the brake drum 64, and the hydraulic actuator (hydraulic cylinder) 34, for example, is fixed as a vibration generating unit 20 by a fixing means such as a bolt 36. At this time, the cylinder end portion 34a of the hydraulic actuator 34 is fixed so as to come into contact with the standing surface of the notch 64a. On the other hand, the end portion of the piston rod 34b of the hydraulic actuator 34 is disposed so as to contact an anchor portion 66 disposed at a position where the brake shoe is to be fixed on the backing plate. A hydraulic drive unit 40 is connected to the hydraulic actuator 34 fixed in this manner, and the pressurization state of the piston rod 34b changes under the control of the vibration control unit 22, and the brake drum 64, the backing plate (anchor unit 66), and the like. Move relatively, and vibration in the tangential direction of the brake drum 64 is generated.

  For example, when the brake shoe presses a portion of the brake drum that is not shaved (portion closer to the center of the drum than other portions), the braking force increases. That is, a large force acts between the brake drum 64 and the anchor portion 66. In this state, in the configuration of FIG. 5, the hydraulic actuator 34 is pressurized and the piston rod 34b protrudes to supply a large acting force as a backing plate input, and as a reaction, the brake drum 64 is strongly pushed back (drum input). Can be reproduced.

  On the other hand, when the brake shoe presses the shaved inner surface of the brake drum 64 (the part farther from the drum center than the other part), the braking force is reduced. That is, the force acting between the brake drum 64 and the anchor portion 66 is reduced. In this state, in the configuration shown in FIG. 5, the pressurization operation of the hydraulic actuator 34 is reduced, the backing plate input (acting force) by the piston rod 34b is reduced, and the force (drum input) for pushing the brake drum 64 is counteracted. It can be reproduced by making it smaller.

  By periodically switching the applied pressure of the hydraulic actuator 34 as described above, the acting force and the reaction force acting between the brake drum 64 and the anchor portion 66 (backing plate) fluctuate at high speed. Vibration similar to that in the case of attempting to brake the brake drum 64 that is unevenly worn by the brake shoe is generated.

  At this time, the pressurizing cycle of the hydraulic actuator 34 is the same as that for the disc brake described above, for example, as shown in FIG. Therefore, as shown in FIG. 3, by controlling the hydraulic actuator 34 so that the pressurization period is gradually extended, vibration similar to that of an actual judder can be simulated also in the drum brake. Also in FIG. 5, for example, a strain gauge 22 a is attached to the piston rod 34 b as a detection means for monitoring the operation state of the hydraulic actuator 34 and feeding back to the vibration control unit 22. It is reflected in. As a result, a judder with a desired braking force is simulated well.

  By the way, in the vehicle 12, judder accompanying the operation of the brake device may be generated by only one arbitrary wheel, or may be generated by two or three wheels. It may also occur in all four wheels. Therefore, as shown in FIG. 6, it is preferable to apply the judder generator 28 or the judder generator 62 to all four-wheel brake devices so that judder is generated by the brake device at a desired position. In this case, as shown in FIG. 6, the disc brake judder generator 28 may be arranged on the front side, and the drum brake judder generator 62 may be arranged on the rear side. The generator 28 and the four wheels may be the judder generator 62. Of course, a drum brake for the front side and a disc brake for the rear side may be arranged.

  The vibration analysis unit 26 acquires vibration information on the judder generated by the judder generators 28 and 62 obtained by the sensors 24 arranged on the steering wheel 14, the seat 68, the floor 70, etc. The vibration characteristics of each part are analyzed.

  In this case, it is preferable that the vibration control unit 22 individually controls the judder generator 28 (62) via each hydraulic drive unit 40 as shown in FIG. For example, a large judder may be generated by the front-side judder generator 28, and a small judder may be generated by the rear-side judder generator 62, or judder having different strengths may be generated individually.

  In the present embodiment, an example in which a hydraulic actuator (hydraulic cylinder) is used as the vibration generating unit 20 has been described. However, a period between the rotating body (rotor or brake drum) and the support body (caliper or backing plate) is shown. Any means can be used as long as it is a vibration generating section capable of applying a general vibration. For example, an electromagnetic actuator or a piezo element may be used. Further, even if an eccentric cam or the like is rotated by using a motor while controlling the added point speed to obtain a desired vibration stroke, the same effect as in this embodiment can be obtained.

  2 and 5 show an example in which the hydraulic actuator 34 is disposed horizontally, but the position corresponding to the actual position of the caliper caliper or the arrangement of the anchor portion of the drum brake is shown. The rotor and the brake drum may be arranged so that the vibration in the tangential direction can be generated.

  In the present embodiment, an example in which the tire holding portion 18 is always used has been described. However, as described above, when the vehicle is traveling at a low speed, the restraining force (resistance) is increased by the ground contact surface. In other words, when trying to simulate judder at low speed, it may not be necessary to make the tire free. In such a case, even if a vehicle equipped with the judder generator 28 or the judder generator 62 is directly placed on the road surface and the judder is generated and the judder measurement is performed, the judder generated in the low-speed actual traveling can be simulated. Can do. Therefore, you may make it use the tire holding | maintenance part 18 suitably according to the speed which judder has generate | occur | produced.

It is explanatory drawing explaining schematic structure of the judder measurement system using the judder generator which concerns on embodiment. It is explanatory drawing explaining schematic structure of the judder generator for disc brakes concerning embodiment. It is explanatory drawing explaining an example of the vibration period of the judder generator which concerns on embodiment. It is explanatory drawing explaining schematic structure of the tire holding | maintenance part of the judder generator which concerns on embodiment. It is explanatory drawing explaining the judder generator schematic structure for drum brakes concerning embodiment. It is explanatory drawing explaining the example which has arrange | positioned the judder generator which concerns on this embodiment to all four wheels of a vehicle. It is explanatory drawing explaining the cause of judder generation in a disc brake.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Judder measurement system, 12 Vehicle, 14 Steering, 16 Tire, 18 Tire holding part, 20 Vibration generation part, 22 Vibration control part, 22a Strain gauge, 24 Sensor, 26 Vibration analysis part, 28, 62 Judder generation apparatus, 30 Rotor , 30a, 64a Notch, 32 Caliper, 34 Hydraulic actuator, 34a Cylinder end, 34b Piston rod, 36, 60 bolt, 38 Flat plate, 40 Hydraulic drive unit, 42 Base plate, 44, 44a, 44b, 44c, 44d Strut, 46a, 46b stay, 48 wires, 50 support plate, 52 load block, 54 bolt, 56 load rod, 58 support block, 64 brake drum, 66 anchor part, 68 seat, 70 floor.

Claims (9)

A judder generator for simulating and generating judder associated with a brake operation in a brake device for braking the rotating body by pressing a friction body supported by a support body on a rotating body rotating together with a tire,
A vibration generating unit that is disposed between the rotating body and the support body and applies vibrations in a tangential direction of a rotation axis of the rotating body to the rotating body and the support body;
A vibration control unit that vibrates the vibration generating unit at a predetermined period;
The judder generator characterized by including. The apparatus of claim 1.
The brake device is a disc brake device,
The rotating body is a rotor, and the support is a caliper;
The judder generator is characterized in that the vibration generator is fixed so that an excitation force is applied to the caliper and a reaction force generated at that time is applied to the rotor. The apparatus of claim 1.
The brake device is a drum brake device,
The rotating body is a drum, and the support is a backing plate;
The judder generator is characterized in that the vibration generator is fixed so that an excitation force is applied to the backing plate and a reaction force generated at that time is applied to the drum. The apparatus according to any one of claims 1 to 3,
The said vibration control part can change arbitrarily the vibration characteristic to generate | occur | produce, The judder generator characterized by the above-mentioned. In the judder generator as described in any one of Claims 1-4,
Furthermore, including a tire holding part for holding the tire,
The tire holding unit holds the movement of the tire in the rotation direction and the steering direction in a free state while suppressing translation of the tire from front to back and from side to side. The apparatus of claim 5.
The tire holding unit includes a load applying unit that applies a predetermined load in the front-rear direction of the tire. A judder measurement system equipped with the judder generator according to any one of claims 1 to 5,
A vehicle on which the judder generator is mounted on at least one wheel;
A sensor disposed at a predetermined position of the vehicle for measuring vibration;
A vibration analyzer for analyzing vibrations measured by the sensor;
A judder measurement system comprising: The measurement system according to claim 7, wherein
The judder generator system generates judder simultaneously with at least two wheels. The measurement system according to claim 8, wherein
A judder measuring system in which a plurality of judder generators are mixed for disc brakes and drum brakes.

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