JP2008207733A - Unsprung vibration damping device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce unsprung vibration with a wide frequency range when unsprung vibration is damped by using a brake caliper constituting a disk brake device to brake a wheel as a mass body of a dynamic vibration absorber. <P>SOLUTION: An unsprung vibration damping device comprises a controller 31 controlling a liquid pressure control circuit 13 to generate liquid pressure for pressing a frictional pad 4 installed in a brake caliper 2 against a brake roller 3. When normally traveling without the necessity of braking a wheel, the controller controls the liquid pressure control circuit so as to press the friction pad against the brake roller, so that the frictional force between the brake roller and the friction pad is applied to the brake caliper as a mass body of the dynamic vibration absorber. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention uses a brake caliper that constitutes a disc brake device that brakes a vehicle wheel as a mass body of a dynamic vibration absorber, and is a portion on the wheel side of a spring that constitutes a suspension device of a vehicle, a so-called unsprung vibration damping. The present invention relates to an unsprung vibration damping device.

  A so-called spring composed of a wheel-side portion, usually a pneumatic tire and a wheel, constituting a vehicle suspension system, and a knuckle that is rotatably supported and connected to the vehicle-body suspension system. Below, vibration due to unevenness of the road surface is generated, but this unsprung vibration is desired to be reduced because it lowers the grounding property and riding comfort of the wheel.

In response to such a demand, a technique is known that performs unsprung vibration suppression using a brake caliper that constitutes a disc brake device that brakes a wheel as a mass body of a dynamic vibration absorber (see Patent Document 1). According to this, since the existing brake caliper is used as the mass body of the dynamic vibration absorber, unsprung vibration can be effectively suppressed without increasing the unsprung weight.
JP 2006-518296 A

  However, the conventional technique has a drawback that a damping effect can be expected only at a specific frequency determined according to the weight of the brake caliper serving as the mass body of the dynamic vibration absorber and the spring constant of the spring that elastically supports the brake caliper. .

  The present invention has been devised to solve such problems of the prior art, and its main purpose is to use a brake caliper constituting a disc brake device for braking a wheel as a mass body of a dynamic vibration absorber. An object of the present invention is to provide an unsprung vibration damping device configured to reduce unsprung vibrations in a wide frequency range when using the unsprung vibration damping.

  In order to solve such a problem, in the present invention, as shown in claim 1, a brake caliper (2) constituting a disc brake device (1) for braking a wheel is used as a mass body of a dynamic vibration absorber. In the unsprung vibration damping device, which is supported by a support member (caliper bracket 8) so as to be movable in the circumferential direction of the brake rotor (3) via a spring (10), the unsprung vibration damping is performed. Pad driving means (hydraulic pressure control circuit 13, piston 14, hydraulic pressure chamber 15, brake pipe 16, and hydraulic pressure path 17) for pressing the friction pad (4) provided on the caliper against the brake rotor is controlled. A controller (31) is provided, and the controller drives the pad so that the friction pad is brought into pressure contact with the brake rotor during normal running without requiring braking of the wheel. And controlling means, said brake caliper as mass of the dynamic vibration reducer, and to that so as to exert a frictional force between the friction pad and the brake rotor.

  According to this, a solid friction damping vibration system in which a friction force between a brake rotor and a friction pad acts on a brake caliper that functions as a mass body of a dynamic vibration absorber is configured. It exhibits vibration characteristics different from those of a vibration system using only a spring and a viscous damping vibration system in which a viscous damper is provided on the spring, and can reduce unsprung vibration in a wide frequency range.

  In this case, the support member (caliper bracket) is fixed to the wheel support member (knuckle) that rotatably supports the wheel. The spring constituting the dynamic vibration absorber may be interposed between the support member and the brake caliper.

  Further, the brake caliper is disposed so that the circumferential movement direction thereof substantially coincides with the vibration direction of the unsprung vibration to be controlled. In particular, from the standpoint of improving the ground contact and ride comfort, the brake caliper is arranged on the front side or rear side of the brake rotor to mainly suppress the vertical vibration generated under the spring. What is necessary is just to make it move to a substantially vertical direction.

  Furthermore, it is also possible to arrange a plurality of brake calipers for one brake rotor according to the vibration direction of the unsprung vibration to be controlled. In this case, a configuration for individually controlling the friction pad pressing operation for each of the plurality of brake calipers is also possible. For example, a pair of brake calipers are provided at symmetrical positions with the rotation axis in between, and the controller controls the brake calipers that cause the friction pads to perform a pressure contact operation according to the direction of acceleration detected by the acceleration sensor. It is also possible. Thereby, controllability can be ensured and it can avoid that the damping effect falls.

  In the unsprung vibration damping device, as shown in claim 2, the unsprung device includes an acceleration sensor (32) for detecting an acceleration generated under the unsprung mass, and the controller is based on the acceleration detected by the acceleration sensor. It can be set as the structure which controls the press-contact operation | movement of a friction pad. According to this, since it becomes possible to make the brake caliper perform an optimal motion for the unsprung vibration according to the actual unsprung vibration state based on the acceleration detected by the acceleration sensor, the damping effect is further improved. It can be further enhanced.

  In this case, the acceleration sensor is provided so as to detect acceleration in a direction substantially coinciding with the circumferential movement direction of the brake caliper, that is, in a direction substantially coinciding with the vibration direction of the unsprung vibration to be controlled.

  In the unsprung vibration damping device, as shown in claim 3, the stopper (22) for restricting the movement of the brake caliper relative to the support member, and the friction pad press-contacts the brake rotor to brake a wheel. A stopper driving means for causing the stopper to perform a regulating operation simultaneously with the operation can be provided. According to this, at the time of braking the wheel, the stopper performs a regulating operation simultaneously with the pressure contact operation of the friction pad against the brake rotor, and the movement of the brake caliper is regulated, so that the brake caliper is dragged in the rotation direction of the brake rotor by the friction force. Therefore, it is possible to avoid delaying the rising of the braking force.

  In the unsprung vibration damping device, as shown in claim 4, the stopper driving means (piston 24, hydraulic chamber 25, and hydraulic path 26) utilizes the driving force of the pad driving means to stop the stopper. And a driving force interrupting means (solenoid valve 28) for interrupting transmission of driving force from the pad driving means to the stopper driving means in response to an instruction from the controller, The controller may be configured to hold the stopper in a deregulated state by controlling the driving force blocking means so that the transmission of the driving force is blocked during normal traveling that does not require braking of the wheels. According to this, since the generation source of a special driving force is not required for the operation of the stopper, the device configuration can be simplified. During normal travel, since the stopper is held in the restriction release state, it is possible to avoid the smooth execution of the friction damping control from being hindered by the stopper.

  In this case, the pad driving means for causing the friction pad to perform a pressure contact operation with respect to the brake rotor includes a hydraulic pressure generating means (hydraulic pressure control circuit), and a piston and a hydraulic pressure chamber for converting the hydraulic pressure generated thereby into the pressure contact movement of the friction pad. And a hydraulic pressure path for guiding the hydraulic pressure of the hydraulic pressure generating means to the hydraulic pressure chamber, the stopper driving means includes a piston and a hydraulic pressure chamber for converting the hydraulic pressure into a restricting movement of the stopper, and a friction pad. What is necessary is just to consist of the hydraulic pressure path which branches from the hydraulic pressure path which guides the hydraulic pressure to operate and guides the hydraulic pressure to the hydraulic pressure chamber on the stopper side.

  Further, the driving force interrupting means may be a valve that branches from the hydraulic pressure path that guides the hydraulic pressure to the hydraulic pressure chamber on the friction pad side and closes / opens the hydraulic pressure path that guides the hydraulic pressure to the hydraulic pressure chamber on the stopper side. good.

  In addition to controlling based on the acceleration detected by the acceleration sensor, a sensor for detecting an unsprung state quantity related to unsprung vibration, for example, a suspension device interposed between unsprung and sprung A configuration is also possible in which control is performed based on the output value of a stroke sensor or the like that detects the stroke amount.

  Further, the pad drive means can be configured to mechanically move the friction pad forward and backward with respect to the brake rotor by the driving force of the electric motor, in addition to the configuration to operate the friction pad by hydraulic pressure.

  Moreover, the stopper can be configured to restrict the movement of the brake caliper by restricting the movement of the brake caliper by the frictional force when being pressed against the supporting member, or by restricting the movement of the brake caliper by entering the recess provided in the supporting member. is there.

  In addition to operating the stopper using the driving force of the friction pad driving means, the stopper driving means may be configured to operate the stopper with a driving force independent of the friction pad. In this case, in accordance with an operation command from the controller that has detected the brake operation by an output signal of a brake switch that detects the operation of the brake pedal by the driver, an electrical drive means such as a stopper drive means, for example, a solenoid or an electric motor Should be operated.

  Thus, according to the present invention, the friction pad is controlled to be brought into pressure contact with the brake rotor so that the friction force between the brake rotor and the friction pad acts on the brake caliper as the mass body of the dynamic vibration absorber. Therefore, it is possible to reduce unsprung vibrations in a wide frequency range, and a great effect can be obtained in improving the grounding property and riding comfort of the wheel.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic front view showing a schematic configuration of an unsprung vibration damping device according to the present invention, with a part cut away. FIG. 2 is a schematic cross-sectional view of the unsprung vibration damping device shown in FIG. 1 as viewed from the side. This unsprung vibration damping device uses a brake caliper 2 that constitutes a disc brake device 1 that brakes a vehicle wheel as a mass body of a dynamic vibration absorber, and has more wheels than a spring (not shown) that constitutes a vehicle suspension device. This is the side part, so-called unsprung vibration suppression.

  The brake caliper 2 is disposed on the front side of the brake rotor 3 that rotates together with the wheels, and the friction pad 4 disposed to face the side surface of the brake rotor 3 and the friction pad 4 can be moved forward and backward with respect to the brake rotor 3. The caliper body 5 to hold | maintain is provided.

  As shown in FIG. 1, the caliper body 5 is supported by a caliper bracket (support member) 8 that is fixed to a knuckle (wheel support member) 7 that holds a wheel rotatably and is connected to a suspension device on the vehicle body side. The caliper bracket 8 is provided with a guide rail 9 having an arc shape concentric with the brake rotor 3 so that the caliper body 5 is guided so as to be movable within a predetermined range in the circumferential direction of the brake rotor 3. ing.

  On both sides of the caliper body 5 in the circumferential direction, springs 10 constituting a dynamic vibration absorber are provided so as to be expandable and contractable in the circumferential direction. The springs 10 extend in the caliper bracket 8 in the substantially radial direction of the brake rotor 3. The caliper body 5 is elastically supported by being interposed between the extended spring mounting portion 11 and the caliper body 5.

  Further, here, as a pad driving means for causing the friction pad 4 to perform a pressure contact operation with respect to the brake rotor 3, a hydraulic pressure control circuit (hydraulic pressure generating means) 13 shown in FIG. 1 and a frictional force as shown in FIG. Piston 14 that holds the pad 4, hydraulic chamber 15 that applies hydraulic pressure from the back side of the piston 14, brake piping 16 that guides the hydraulic pressure generated by the hydraulic control circuit 13 to the brake caliper 2, and brake piping 16 Is provided with a fluid pressure path 17 for guiding the fluid pressure guided by the fluid pressure chamber 15 in the caliper body 5.

  A hydraulic pressure control circuit (VSA modulator) 13 controls the braking force of each wheel based on vehicle body information such as vehicle speed, yaw rate, and lateral acceleration in order to suppress side slip during turning and improve directional stability. The vehicle behavior stabilization control system is configured, and the hydraulic pressure can be controlled over a wide range from a low pressure where the friction pad 4 is lightly pressed against the brake rotor 3 to a high pressure for obtaining a large braking force required for deceleration of the vehicle body. it can.

  The hydraulic pressure control circuit 13 is connected to an output port of the master cylinder 20 that generates a hydraulic pressure corresponding to the pedaling force applied to the brake pedal 19 by the driver, and a required hydraulic pressure is set according to the operation of the brake pedal 19. The brake caliper 2 is supplied. The hydraulic pressure control circuit 13 controls the hydraulic pressure supplied to the brake caliper 2 by opening and closing an internal electromagnetic valve in accordance with an operation command from the controller 31.

  The controller 31 receives output signals from a vertical acceleration sensor 32 that is fixed to the knuckle 7 and detects the vertical acceleration generated under the spring, and a wheel speed sensor 33 that detects the rotational speed of the wheel. Based on the vertical acceleration and the wheel speed, a calculation process required for vibration suppression control is performed in the vibration suppression operation calculation unit. The controller 31 receives an output signal of a brake switch 34 that detects an operation of the brake pedal 19 by the driver.

  Further, the caliper body 5 is provided with a caliper stopper 22 that restricts the movement of the caliper body 5 relative to the caliper bracket 8, and further, a piston that holds the caliper stopper 22 as a stopper driving means that causes the caliper stopper 22 to perform a restricting operation. 24, a hydraulic pressure chamber 25 that applies hydraulic pressure from the back side of the piston 24, and a hydraulic pressure passage 26 that branches from the hydraulic pressure passage 17 that guides the hydraulic pressure that operates the friction pad 4 and communicates with the hydraulic pressure chamber 25. The caliper stopper 22 operates in conjunction with the friction pad 4 by the hydraulic pressure generated by the hydraulic pressure control circuit 13.

  Further, the caliper body 5 is closed by a hydraulic path 26 that branches from a hydraulic path 17 that guides hydraulic pressure to the hydraulic chamber 15 on the friction pad 4 side and guides hydraulic pressure to the hydraulic chamber 25 on the caliper stopper 22 side. A solenoid valve (driving force interrupting means) 28 to be opened is provided. The solenoid valve 28 is controlled to be opened and closed by a controller 31 according to whether or not the brake pedal 19 is operated.

  In the unsprung vibration damping device configured in this way, during normal running when the brake pedal 19 is not operated, the friction for controlling the pressure contact operation of the friction pad 4 against the brake rotor 3 by the hydraulic pressure generated by the hydraulic pressure control circuit 13. Vibration suppression control is performed, and in this friction vibration suppression control, the friction force F generated between the brake rotor 3 and the friction pad 4 acts on the brake caliper 2 that functions as a mass body of the dynamic vibration absorber. The vibration characteristics change, and unsprung vibrations in a wide frequency range can be reduced.

  At this time, since the solenoid valve 28 is closed, the hydraulic pressure generated by the hydraulic pressure control circuit 13 acts only on the piston 14 of the friction pad 4, even if the hydraulic pressure is increased by the hydraulic pressure control circuit 13. The caliper stopper 22 is held in the restriction release state, whereby the friction damping control is smoothly performed.

  On the other hand, at the time of braking in which the brake pedal 19 is operated to decelerate the wheel, the solenoid valve 28 is opened, and the hydraulic pressure generated by the hydraulic pressure control circuit 13 is applied to the piston 24 of the caliper stopper 22 together with the piston 14 of the friction pad 4. As a result, the caliper stopper 22 moves forward and comes into pressure contact with the guide rail 9, the movement of the caliper body 5 with respect to the caliper bracket 8 is restricted, and the braking force quickly rises.

  In the friction damping control, the friction pad 4 is brought into pressure contact with the brake rotor 3 with a constant hydraulic pressure, and the pressure contact force of the friction pad 4 with respect to the brake rotor 3 is increased or decreased so as to obtain optimum damping characteristics. It is also possible to perform a control to In this case, the control may be performed based on the unsprung state quantity such as the direction and magnitude of unsprung acceleration detected by the vertical acceleration sensor 32. In addition, depending on the unsprung vibration state, the friction pad 4 is not brought into pressure contact, and the vibration damping mode is made to function as a dynamic vibration absorber made up of the vibration system of only the mass body and the spring. It is also possible to control to switch between modes.

  FIG. 3 is a schematic front view similar to FIG. 1 showing another example of the unsprung vibration damping device according to the present invention. Here, the brake caliper 2 is arranged before and after the brake rotor 3. As in the example of FIG. 1, each brake caliper 2 is supplied with hydraulic pressure generated by a hydraulic pressure control circuit (VSA modulator) 13 via a brake pipe 16, and each caliper body. 5 is provided with a caliper stopper 22 and a solenoid valve 28. The hydraulic pressure supply from the hydraulic pressure control circuit 13 and the opening / closing operation of the solenoid valve 28 can be individually controlled by the front and rear brake calipers 2. .

  FIG. 4 is a schematic diagram illustrating an operable range and an inoperable range in the unsprung vibration damping device illustrated in FIG. 3. At the time of the friction damping control in which the damping characteristic is changed by the friction force between the brake rotor 3 and the friction pad 4, the brake caliper 2 is dragged by the friction rotor 3 and moved in the rotation direction of the brake rotor 3, At this time, when the brake caliper 2 approaches the spring mounting portion 11 of the caliper bracket 8 that supports the brake caliper 2, the spring 10 increases in bending, and therefore, the spring constant increases and the vibration damping characteristic changes. Thus, the friction damping control cannot be performed, and the distance between the brake caliper 2 and the caliper bracket 8 is reduced, which may cause interference and generate noise.

  For this reason, when the brake caliper 2 is positioned within the inoperable range, a predetermined region in which the brake caliper 2 is close to the spring mounting portion 11 of the caliper bracket 8 is located in the inoperable range, friction damping control is performed. Absent.

  The position of the brake caliper 2 can be estimated from the hydraulic pressure and wheel speed at the previous operation instruction, the mass of the brake caliper 2, the spring constants of the springs 10 provided on both sides of the brake caliper 2, and the like.

  In addition, this inoperable range changes according to the state of acceleration occurring under the spring. Therefore, here, control is performed to switch the brake caliper 2 that performs the friction damping control back and forth according to the direction of the acceleration generated by the vertical acceleration sensor 32 provided in the knuckle 7. When an upward acceleration occurs under the spring, the hydraulic pressure of only the brake caliper 2 on the front side is increased to cause the friction pad 4 to perform a pressure contact operation. On the other hand, when downward acceleration is generated under the spring, the hydraulic pressure of only the rear brake caliper 2 is increased and the friction pad 4 is pressed. Thereby, the expected controllability can be ensured.

  FIG. 5 is a flowchart showing an operation procedure of the unsprung vibration damping device shown in FIG. Here, it is determined whether the brake switch 34 for detecting the operation of the brake pedal 19 by the driver is on or off (step 101). When the brake switch 34 is on, the normally closed solenoid valve 28 is opened (step 101). 102) On the other hand, when the brake switch 34 is OFF, caliper control is executed (step 103).

  FIG. 6 is a flowchart showing the caliper control procedure shown in FIG. Here, the direction of unsprung acceleration detected by the vertical acceleration sensor 32 is determined (step 201), and when the unsprung acceleration is upward, the friction pad 4 of the brake caliper 2 on the front side is operated (step 201). 202) If the unsprung acceleration is downward, the friction pad 4 of the rear brake caliper 2 is operated (step 203).

  FIG. 7 is a flowchart showing the procedure of the caliper operation before and after shown in FIG. Here, first, a process for calculating the position of the brake caliper 2 is performed (step 301), and then it is determined whether or not the brake caliper 2 is within the operable range shown in FIG. 4 (step 302). When the caliper 2 is within the operable range, the solenoid valve 28 is closed (step 303), and a boost instruction is output from the controller 31 to the hydraulic pressure control circuit (VSA modulator) 13 (step 304). Thus, the friction pad 4 is brought into pressure contact with the brake rotor 3 at a required pressure by the hydraulic pressure generated by the hydraulic pressure control circuit 13 to perform unsprung vibration suppression.

  As shown in FIG. 1, in the unsprung vibration damping device in which one brake caliper 2 is provided for one brake rotor 3, the driver operates the brake pedal 19 as in the example of FIG. Accordingly, the solenoid valve 28 is opened and closed, and the friction damping control is executed only when the brake caliper 2 is within the operable range, as in the example of FIG.

  Further, in the unsprung vibration damping device shown in FIG. 1, as shown in FIG. 6, control in consideration of the direction of unsprung acceleration is also possible. Specifically, the brake caliper 2 is connected to the brake rotor 3. When arranged on the front side, the friction damping control is executed only when the unsprung acceleration is upward, and on the other hand, when the brake caliper 2 is arranged on the rear side of the brake rotor 3, the spring is controlled. It is also possible to execute the friction damping control only when the downward acceleration is downward.

  In the above example, from the viewpoint of improving ground contact and riding comfort, the brake caliper is arranged on the front side or front and back of the brake rotor in order to mainly suppress the vertical vibration generated under the spring. Although the movement of the brake caliper in the circumferential direction is substantially vertical, the present invention is not limited to this, and the brake caliper with respect to the brake rotor according to the vibration direction of the unsprung vibration to be damped. It is sufficient to appropriately set the arrangement position. The acceleration sensor is also provided so that it can detect the acceleration in the vibration direction of the unsprung vibration to be controlled.

It is a typical front view showing a schematic structure of an unsprung vibration damping device according to the present invention. It is typical sectional drawing which looked at the unsprung damping device shown in FIG. 1 from the side. It is a typical front view similar to FIG. 1 which shows another example of the unsprung damping device by this invention. It is a schematic diagram which shows the operable range and the inoperable range in the unsprung vibration damping device shown in FIG. It is a flowchart which shows the operation | movement procedure of the unsprung damping device shown in FIG. It is a flowchart which shows the procedure of the caliper control shown in FIG. It is a flowchart which shows the procedure of the caliper operation | movement before and behind shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Disc brake device 2 Brake caliper 3 Brake rotor 4 Friction pad 5 Caliper body 7 Knuckle 8 Caliper bracket 9 Guide rail 10 Spring 13 Fluid pressure control circuit 17 Fluid pressure path 19 Brake pedal 22 Caliper stopper 26 Fluid pressure path 28 Solenoid valve 31 Controller 32 Vertical acceleration sensor 33 Wheel speed sensor 34 Brake switch

Claims (4)

A brake caliper that constitutes a disc brake device that brakes a wheel is supported by a support member so as to be movable in the circumferential direction of the brake rotor via a spring as a mass body of a dynamic vibration absorber so as to perform vibration suppression under the spring. An unsprung vibration damping device,
A controller for controlling pad driving means for pressing the friction pad provided on the brake caliper against the brake rotor;
The controller controls the pad driving means so that the friction pad is pressed against the brake rotor during normal driving without requiring braking of the wheel, and the brake caliper as a mass body of the dynamic vibration absorber An unsprung vibration damping device, wherein a frictional force between a rotor and the friction pad is applied. It has an acceleration sensor that detects the acceleration generated under the spring,
2. The unsprung vibration damping device according to claim 1, wherein the controller controls a pressure contact operation of the friction pad based on an acceleration detected by the acceleration sensor. 3. A stopper for restricting movement of the brake caliper relative to the support member;
The stopper driving means for causing the stopper to perform a regulating operation simultaneously with the operation of pressing the friction pad against the brake rotor in order to brake the wheel, according to claim 1 or 2. Unsprung vibration damping device. The stopper driving means causes the stopper to perform a regulating operation using the driving force of the pad driving means;
In response to an instruction from the controller, a driving force interrupting means for interrupting transmission of driving force from the pad driving means to the stopper driving means,
The controller is configured to control the driving force blocking means so that transmission of driving force is blocked during normal traveling that does not require braking of the wheel, thereby holding the stopper in a deregulated state. The unsprung vibration damping device according to claim 3.

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