JP2005022501A - Vehicular brake device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To certainly prevent brake noise, regardless of manufacturing variation of components structuring a device, specifications of the components, age deterioration of the components, and wear. <P>SOLUTION: In the vehicular brake device, pressure applied on a wheel cylinder 4 of a brake hydraulic circuit 3 is changed according to a depressing state of a brake pedal 2, thereby adjusting friction force between a friction material in the wheel cylinder 4 side and a rotating element in a wheel side. A brake ECU variation controls to make pressure in the wheel cylinder 4 side of the brake hydraulic circuit 3 intermittently become almost zero, at a specified frequency. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle brake device that obtains a braking force of a vehicle by driving a wheel cylinder by hydraulic pressure and pressing a friction material against a rotating body.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a brake device for an automobile vehicle, it is common to detect a depression state of a brake pedal and change a pressure applied to a wheel cylinder of a brake hydraulic circuit according to the depression state (for example, Patent Documents). 1). Thereby, the frictional force between the friction material on the wheel cylinder side and the rotating body on the wheel side is adjusted, and the braking force of the vehicle is adjusted.
[0003]
It is well known that a so-called brake squeal occurs when a stick-slip phenomenon occurs between the friction material and the rotating body as a problem of the vehicle brake device. This brake squeal is known to be a self-excited vibration that diverges, and after the stick-slip phenomenon occurs, the brakes are applied to the vehicle occupant and the people around the vehicle when the sound pressure level falls within the human audible sound range. The squeal will be recognized.
[0004]
Brake squeal is likely to occur in the disc brake type that is becoming mainstream in automobile vehicles in recent years. In order to solve this problem, suppression of brake squeal is achieved by adjusting the natural frequencies of a brake rotor as a rotating body and a brake pad as a friction material.
[0005]
[Patent Document 1]
JP-A-10-184747
[0006]
[Problems to be solved by the invention]
However, in the vehicle brake device, even if the natural frequency of the parts such as the rotating body and the friction material is set so that the brake squeal is less likely to occur, of course, the brake squeal occurs due to variations at the time of manufacturing the part. When the natural frequency of each part changes due to long-term use or the like due to aging or wear, there is a problem that brake squeal occurs.
In addition, even if only some parts are replaced, the natural frequency changes as a whole, so that a brake squeal occurs. Therefore, a confirmation experiment is required each time, and a large number of development test man-hours are required. . Therefore, it is not possible to replace only some parts depending on the vehicle type, grade, and the like. Accordingly, there is a problem that parts cannot be diverted between different vehicle types and grades, resulting in increased manufacturing costs.
[0007]
The present invention has been made in view of the above circumstances, and an object of the present invention is to ensure brake squealing without being caused by manufacturing variations of parts constituting the apparatus, specification of parts, aging of parts, wear, etc. Another object of the present invention is to provide a vehicular brake device that can be prevented.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, the friction material on the wheel cylinder side and the wheel side friction material are changed by changing the pressure applied to the wheel cylinder of the brake hydraulic circuit according to the depression state of the brake pedal. In a vehicle brake device that adjusts a frictional force with a rotating body, a frequency control means for controlling the pressure on the wheel cylinder side of the brake hydraulic circuit to fluctuate at a predetermined frequency so as to be intermittently substantially zero. It is provided with.
[0009]
According to the first aspect of the present invention, when the stick-slip phenomenon occurs between the rotating body and the friction material, the pressure on the wheel cylinder side of the brake hydraulic circuit intermittently becomes substantially zero. The friction between the rotating body and the friction material is temporarily released, and the stick-slip phenomenon is released accordingly. Thereby, the vibration energy between the rotating body and the friction material is released before the vibration energy between the rotating body and the friction material is accumulated and the vibration reaches the audible sound region.
Here, since the pressure on the wheel cylinder side that fluctuates at a predetermined frequency only becomes almost zero intermittently, a necessary braking force is applied to the wheel, and the braking of the wheel is not hindered.
[0010]
Therefore, the vibration of the rotating body and the friction material does not reach the audible sound range, and the rotating body and the friction material are independent of the manufacturing variation of the parts constituting the device, the specifications of the parts, the aging of the parts, the wear, etc. The brake squeal can be reliably prevented. Thereby, development test man-hours can be significantly reduced. In addition, some parts can be diverted between different vehicle types and grades, and the manufacturing cost of the vehicle can be reduced.
[0011]
According to a second aspect of the present invention, in the vehicle brake device according to the first aspect, the frequency control means has a linear control valve provided between the pressure generating device of the brake hydraulic circuit and the wheel cylinder. It is characterized by.
[0012]
According to the second aspect of the invention, in addition to the operation of the first aspect, the pressure on the wheel cylinder side can be changed to a predetermined frequency by variably controlling the hydraulic pressure by the linear control valve. Therefore, vibration noise due to valve switching can be suppressed rather than pressure adjustment by the switching valve, which is extremely advantageous in practical use.
[0013]
According to a third aspect of the present invention, in the vehicle brake device according to the first or second aspect, the brake hydraulic circuit applies pressure to the wheel cylinder side from a pressure generating device corresponding to a depression state of the brake pedal. A normal control circuit unit for transmitting, and a master cylinder circuit unit for transmitting pressure from the master cylinder interlocked with the depression of the brake pedal to the wheel cylinder side instead of the normal control circuit unit under a predetermined vehicle condition; The normal control circuit and the master cylinder circuit are connected so that the pressure of the pressure generator of the normal control circuit is supplied to the master cylinder circuit.
[0014]
According to the third aspect of the present invention, in addition to the operation of the first or second aspect, during normal driving of the vehicle, pressure is transmitted from the pressure generating device to the wheel cylinder side by the normal control circuit unit, so The wheel is braked with a great force.
Also, when the vehicle is in a predetermined vehicle state, for example, when hydraulic pressure control has failed due to a failure, the occupant's pedaling power is directly transmitted as pressure to the wheel cylinder side by the master cylinder instead of the normal control circuit unit. The At this time, pressure is supplied from the pressure generator of the normal control circuit section to the master cylinder circuit section side so that the general mechanical hydraulic hydro booster function can be continued, so that the occupant's stepping power is amplified Is transmitted to the wheel cylinder side.
[0015]
Therefore, even when pressure is transmitted to the wheel cylinder by the master cylinder circuit unit, the wheel can be braked with the assistance of the pressure generating device, and even when the occupant's stepping power is small, sufficient braking force can be obtained. Can be obtained.
[0016]
According to a fourth aspect of the present invention, in the vehicle brake device according to the second or third aspect, the brake hydraulic circuit controls the wheel cylinders on the left side of the front shaft and the right side of the rear shaft in synchronism with each other. The wheel cylinders on the right side and the left side of the rear axle are controlled synchronously, and the frequency of pressure fluctuations between the wheel cylinders on the left side of the front axis and the right side of the rear axis and the wheel cylinders on the right side of the front axis and the left side of the rear axis is controlled. The phase is shifted by approximately 180 degrees.
[0017]
According to the fourth aspect of the invention, in addition to the action of the second or third aspect, the phase of the frequency of the pressure fluctuation is shifted by approximately 180 degrees between the left and right wheels of the front shaft and the rear shaft. The fluctuation in braking force can be reduced, and a temporary decrease in braking force of the entire vehicle can be prevented.
[0018]
According to a fifth aspect of the present invention, in the vehicle brake device according to the second or third aspect, the brake hydraulic circuit includes wheel cylinders on the left side of the front shaft, the right side of the front shaft, the left side of the rear shaft, and the right side of the rear shaft. It is controlled independently, and the phase of the pressure fluctuation frequency is shifted by about 180 degrees between the left wheel cylinder and the right wheel cylinder on the front and rear axles of the vehicle, respectively. Features.
[0019]
According to the fifth aspect of the invention, in addition to the action of the second or third aspect, the phase of the frequency of the pressure fluctuation is shifted by about 180 degrees between the front and rear left and right wheels. The fluctuation in braking force can be reduced, and a temporary decrease in braking force of the entire vehicle can be prevented.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
1 to 6 show an embodiment in which the present invention is applied to a diagonal piping brake device. FIG. 1 is a schematic hydraulic circuit diagram of a vehicle brake device, and FIG. 2 is a schematic block diagram of the vehicle brake device. Fig. 3 is a map that defines the relationship between the master side pressure detector and the average pressure, and Fig. 4 is a diagram showing the pressure difference between the pressure detected by the wheel side pressure detector and the target sine pressure wave P (t), and linear addition. FIG. 5 is a flowchart showing the operation of the brake ECU, and FIG. 6 is a graph showing the pressure fluctuation on the wheel cylinder side and the sound pressure level of the rotor and pad vibrations. It is a graph to show.
[0021]
As shown in FIG. 1, the vehicle brake device 1 changes the hydraulic pressure applied to the wheel cylinder 4 of the brake hydraulic circuit 3 in accordance with the depression state of the brake pedal 2, so that the brake pad on the wheel cylinder 4 side is changed. The frictional force between the wheel and the wheel-side rotor is adjusted. Thereby, when the brake pedal 2 is stepped on by the occupant, a braking force is applied to the vehicle in accordance with the stepped state.
[0022]
The brake hydraulic circuit 3 includes a normal control circuit unit 10 that transmits pressure from the accumulator 11 side as a pressure generating device to the wheel cylinder 4 side in response to the depression state of the brake pedal 2, and the depression of the brake pedal 2. And a master cylinder circuit unit 20 that transmits pressure from the interlocking master cylinder 21 to the wheel cylinder 4 side.
[0023]
The normal control circuit unit 10 includes an accumulator 11 as a pressure generating device, a leakage valve 12 that is closed during non-braking and non-hydraulic control when the accumulator 11 is refilled, and a wheel cylinder from the accumulator 11 side. The linear pressurization control valve 13 that can linearly pressurize the pressure transmitted to the 4 side, and the first state that is closed during non-hydraulic control when the master cylinder circuit unit 20 supplies the pressure to the wheel cylinder 4 side. A switching control valve 14 is provided in series in this order from the accumulator 11 to the wheel cylinder 4.
[0024]
In the present embodiment, a pipe from the master cylinder 21 is connected between the accumulator 11 and the leakage valve 12. A pump 15 for supplying pressure to the accumulator 11 is provided in this pipe portion. The pump 15 is activated and stopped based on the pressure detected by the accumulator pressure detector 16 connected between the accumulator 11 and the leakage valve 12.
A pipe from the linear pressurization control valve 13 and the first switching control valve 14 to the reservoir tank 30 is connected. A linear pressure reduction control valve 17 capable of linearly reducing the pressure transmitted from the accumulator 11 side to the wheel cylinder 4 side is provided in this piping portion.
[0025]
In the present embodiment, the wheel cylinder 4 side from the linear pressurization control valve 13 is connected to the first pipe 10a for supplying pressure to the wheel cylinder 4 side corresponding to the front axle left side and the rear axle right side of the vehicle, the front axle right side, Branches to a second pipe 10b for supplying pressure to the wheel cylinder 4 side corresponding to the left side of the rear shaft. The first switching control valve 14 described above is provided for each of the pipes 10a and 10b.
[0026]
The master cylinder control circuit unit 20 includes a master cylinder 21 connected to the brake pedal 2 and a second switching control valve 22 that is closed when pressure is supplied to the wheel cylinder 4 side by the normal control circuit unit 10. is doing. That is, the master cylinder control circuit unit 20 transmits the pressure to the wheel cylinder 4 side instead of the normal control circuit unit 10 under a predetermined vehicle condition. In the present embodiment, the third pipe 20a that supplies pressure from the master cylinder 21 to the wheel cylinder 4 side corresponding to the front left side and the rear right side of the vehicle, and the wheel cylinder 4 corresponding to the front right side and the rear left side. The 4th piping 20b which supplies a pressure to the side is connected independently. The aforementioned second switching control valve 22 is provided for each of these pipes 20a, 20b.
[0027]
In the present embodiment, the master cylinder 21 is connected to the reservoir tank 30 and is connected between the accumulator 11 and the leakage valve 12 of the normal control circuit unit 10. Thereby, the pressure from the accumulator 11 is supplied also to the master cylinder circuit part 20, and the general mechanical hydraulic hydro booster function is provided.
[0028]
The first pipe 10 a of the normal control circuit unit 10 and the third pipe 20 a of the master cylinder control circuit unit 20 merge between the switching control valves 14 and 22 and the wheel cylinder 4. Then, after merging, it branches into a front left cylinder pipe 31 that goes to the left wheel cylinder 4 and a rear right cylinder pipe 32 that goes to the right wheel cylinder 4.
[0029]
Further, the second pipe 10 b of the normal control circuit unit 10 and the fourth pipe 20 b of the master cylinder control circuit unit 20 merge between the switching control valves 14 and 22 and the wheel cylinder 4. Then, after merging, it branches into a front shaft right cylinder cylinder pipe 33 heading toward the wheel cylinder 4 of the front right wheel and a rear shaft left cylinder pipe 34 heading toward the wheel cylinder 4 of the rear left wheel.
[0030]
Each cylinder pipe 31, 32, 33, 34 is provided with an ABS pressure control valve 35, respectively. Each cylinder pipe 31, 32, 33, 34 is connected to the reservoir tank 30 via an ABS pressure reduction control valve 36.
[0031]
In the brake hydraulic circuit 3 of the vehicle brake device 1, during normal control, each first switching control valve 14 is opened and each second switching control valve 22 is closed, so that the normal control circuit unit 10 removes from the accumulator 11. Pressure is supplied to each wheel cylinder 4. A wheel-side pressure detector 37 that detects the pressure supplied to the wheel cylinder 4 during normal control is connected to the first pipe 10a and the second pipe 10b of the normal control circuit unit 10, respectively. In addition, the third pipe 20a and the fourth pipe 20b of the master cylinder control circuit unit 20 include a master side that detects pressure fluctuation due to movement of the master cylinder 21 in the master cylinder control circuit unit 20 that is closed circuit during normal control. A pressure detector 38 is connected.
[0032]
The brake hydraulic circuit 3 has a stroke simulator 39. The stroke simulator 39 is configured such that the internal piston moves backward by the amount of liquid discharged from the master cylinder 21 according to the pedal operation stroke and can temporarily flow in, and the second switching control valve 22 is closed and the pedal is closed. This is a device for preventing a feeling of treading when operated. Moreover, in order to give an appropriate pedal reaction force, a reaction force spring is built in, and when the pedal returns, the amount of fluid that flows in by the spring pressure is discharged.
[0033]
That is, during normal control, the brake ECU 100 of the vehicle brake device 1 detects the movement state of the master cylinder 21 based on the depression state of the brake pedal 2 from the master side pressure detector 38, and the actual pressure of the wheel cylinder 4 is detected. The linear pressure control valve 13 and the linear pressure reduction control valve 17 are controlled so that the pressure of the wheel cylinder 4 corresponds to the depression state of the brake pedal 2. Hereinafter, the brake ECU 100 will be described with reference to FIG.
[0034]
As shown in FIG. 2, the brake ECU 100 is connected to the above-described linear pressurization control valve 13, linear pressure reduction control valve 17, wheel side pressure detector 37, and master side pressure detector 38. The brake ECU 100 calculates a target pressure Pm on the wheel cylinder 4 side based on the pressure detected by the master side pressure detector 38. In the present embodiment, as shown in the map of FIG. 3, the target pressure Pm is uniquely determined from the detected pressure in the master side pressure detector 38. Then, the target sine pressure wave P (t) is calculated so that the target pressure Pm becomes the average pressure. In the present embodiment, this target sine pressure wave P (t) is
P (t) = Pm × (1-cos (2πf × t))
f: Frequency
t: time
It is determined by the following formula. As is apparent from this equation, the target sine pressure wave P (t) becomes zero intermittently. In the present embodiment, the frequency f is about 20 Hz.
[0035]
Moreover, the brake ECU 100 applies a predetermined low-pass filter to the actual pressure waveform detected by the wheel side pressure detector 37 to remove noise and the like. The pressure waveform acquired in this way is compared with the target sine pressure wave P (t), and the correction amount by each of the linear control valves 13 and 17 is calculated. Then, as shown in FIG. 4, the linear control valves 13 and 17 are selectively driven according to the calculated correction amount. Thereby, the pressure on the wheel cylinder 4 side is controlled so as to approach the target sine pressure wave P (t). That is, in the present embodiment, the brake ECU 100, the linear control valves 13, 17 and the like constitute frequency control means.
[0036]
Here, the operation of the brake ECU 100 will be described with reference to the flowchart shown in FIG.
First, when the vehicle is turned on, it is determined whether there is an abnormality in each part of the device (step S1). If there is no abnormality, it is determined whether there is an abnormality in the system related to the pressure frequency control (step S2). .
[0037]
If it is determined in step S1 that there is an abnormality, the system is brought down as a non-control mode (step S5), an alarm relating to the brake system is output (step S6), and installed in the meter panel of the driver's seat. Turn on the warning light. At this time, hydro booster pressurization using the residual pressure of the accumulator 11 by pedal operation is performed in the master cylinder circuit unit 20.
[0038]
Further, when it is determined in step S2 that there is an abnormality, the non-frequency control for controlling the pressure on each wheel cylinder side 4 not to be the target sine pressure wave P (t) but to be constantly the average pressure Pm. The mode is changed (step S3). And the warning regarding the frequency control system of a brake is output (step S4), for example, the warning light incapable of squeal prevention control installed on the meter panel of the driver's seat is turned on.
[0039]
If it is determined in step S2 that there is no abnormality in the frequency control system, the frequency control mode is entered. Then, as described above, control is performed so that the pressure on the wheel cylinder 4 side becomes the target sine pressure wave P (t) (step S7).
[0040]
As shown in FIG. 6, since the pressure fluctuation on the wheel cylinder 4 side in step S7 is intermittently almost zero, the vibration energy accumulated by the friction between the rotor and the pad is periodically released, and the sound pressure of the rotor is also reduced. Moreover, it periodically becomes zero.
[0041]
Thus, according to the vehicle brake device 1 of the present embodiment, when a stick-slip phenomenon occurs between the rotor and the pad, the pressure on the wheel cylinder 4 side of the brake hydraulic circuit 3 is intermittently applied. Since it becomes almost zero, the friction between the rotor and the pad is temporarily released, and the stick-slip phenomenon is released accordingly. Thereby, the vibration energy between the rotor and the pad is released before the vibration energy between the rotor and the pad is accumulated and the vibration reaches the audible sound region.
In the present embodiment, the rotor and the pad are a combination in which the continuation time of friction is about 90 to 100 milliseconds and a brake squeal in the audible sound pressure range occurs, and the rotor is set at a frequency f of about 20 Hz every about 50 milliseconds. The brake squeal is almost certainly prevented by releasing the friction between the pad and the pad.
Here, since the pressure on the wheel cylinder 4 side that fluctuates at the frequency f only becomes almost zero intermittently, a necessary braking force is applied to the wheel, and the braking of the wheel is not hindered.
[0042]
Therefore, the vibration of the rotor and the pad does not reach the audible sound range, and the brake noise of the rotor and the pad is generated regardless of the manufacturing variation of the parts making up the device, the specifications of the parts, the aging of the parts, the wear, etc. It can be surely prevented. Thereby, development test man-hours can be significantly reduced. In addition, some parts can be diverted between different vehicle types and grades, and the manufacturing cost of the vehicle can be reduced.
[0043]
Moreover, according to the vehicle brake device 1 of the present embodiment, the pressure on the wheel cylinder 4 side can be changed to the frequency f by variably controlling the hydraulic pressure by the linear control valves 13 and 17. Therefore, vibration noise such as hydraulic hammering due to valve switching can be suppressed rather than pressure adjustment by the switching valve, which is extremely advantageous in practical use.
[0044]
Further, according to the vehicle brake device 1 of the present embodiment, during normal driving of the vehicle, pressure is transmitted from the accumulator 11 to the wheel cylinder 4 side by the normal control circuit unit 10, and the wheel is driven with a force greater than the stepping power of the occupant. Will be braked.
Further, in a predetermined vehicle state such as when the hydraulic pressure control is lost due to a failure, for example, instead of the normal control circuit unit 10, the occupant's stepping power is directly applied to the wheel cylinder 4 side by the master cylinder 21. As transmitted. At this time, pressure is supplied from the accumulator 11 of the normal control circuit unit 10 to the master cylinder circuit unit 20 side so that a general mechanical hydraulic hydro booster function can be continued, so that the occupant's stepping power is amplified. It is transmitted to the wheel cylinder 4 side in the state.
[0045]
Therefore, even when pressure is transmitted to the wheel cylinder 4 by the master cylinder circuit unit 20, the wheel can be braked with the assistance of the accumulator 11, and even if the occupant's pedaling power is small, sufficient control is achieved. Power can be obtained.
[0046]
In the above-described embodiment, one linear pressurization control valve 13 and one linear pressure reduction control valve 17 are provided to control both of the diagonal pipes of the vehicle with the same pressure. 7, linear pressurization control valves 113 are provided in the first pipe 10a and the second pipe 10b, respectively, and the pipes 10a, 10b and the reservoir tank 30 are connected via the linear pressure reduction control valve 114. It may be.
[0047]
Also with the configuration of FIG. 7, it is possible to obtain the same operational effects as the above-described embodiment. In this case, the brake hydraulic circuit 103 synchronizes and controls the wheel cylinders 4 on the left side and the right side of the rear axis of the vehicle, and controls the wheel cylinders 4 on the right side and the left side of the rear axis in synchronization. Here, by independently controlling each linear pressurization control valve 113 and each linear pressure-reduction control valve 114, the phase of the frequency of pressure fluctuation is shifted by approximately 180 degrees between the first pipe 10a and the second pipe 10b. By controlling, it is preferable that the phase of the frequency of the pressure fluctuation is shifted by approximately 180 degrees between the wheel cylinders 4 on the left and right sides of the front shaft and the wheel cylinders 4 on the right and left sides of the front shaft. By controlling in this way, the phase of the frequency of pressure fluctuation is shifted by approximately 180 degrees between the left and right wheels of the front and rear axes, and the braking force fluctuation of the entire left and right wheels can be reduced. A decrease in braking force can be prevented.
[0048]
Further, for example, as shown in FIG. 8, instead of the linear pressure increase control valve 13 and the linear pressure decrease control valve 17 in the embodiment, each ABS pressure increase control valve 35 and each ABS pressure decrease control valve 36 are respectively linearly pressure controlled. The valve 213 and the linear pressure reduction control valve 217 may be used. Also with the configuration of FIG. 8, it is possible to obtain the same operational effects as in the above embodiment.
[0049]
In this case, the brake hydraulic circuit 203 controls each linear pressure control valve 213 and each linear pressure-reduction control valve 217 independently, so that the front left side, front right side, rear left side and rear right side of the vehicle are controlled. These wheel cylinders 4 can be controlled independently. Also in this case, it is preferable that the left and right wheel cylinders 4 and 4 are controlled so that the phase of the frequency of the pressure fluctuation is shifted by approximately 180 degrees on the front and rear axles of the vehicle, respectively. By controlling in this way, the phase of the frequency of pressure fluctuation is shifted by approximately 180 degrees between the left and right wheels of the front and rear axes, and the braking force fluctuation of the entire left and right wheels can be reduced. A decrease in braking force can be prevented.
[0050]
Further, the expression of the target sine pressure wave P (t) in the above embodiment may be another expression as long as it becomes intermittently almost zero. Further, the vehicle brake device 1 is shown as a disc type, but may be a drum type, for example, and it is of course possible to appropriately change the specific detailed structure and the like. is there.
Moreover, although the example applied to the brake device of diagonal piping system was shown in the said embodiment, it can implement similarly in the brake device of front and rear piping system.
[0051]
【The invention's effect】
As described above in detail, according to the present invention, the vibration energy between the rotating body and the friction material is accumulated before the vibration energy reaches the audible sound region. Because it was opened, the vibration of the rotating body and friction material did not reach the audible sound range, regardless of variations in the parts that make up the device, specifications of the parts, aging of parts, wear, etc. The brake noise of the rotating body and the friction material can be reliably prevented. Thereby, development test man-hours can be significantly reduced. In addition, some parts can be diverted between different vehicle types and grades, and the manufacturing cost of the vehicle can be reduced.
[Brief description of the drawings]
FIG. 1 is a schematic hydraulic circuit diagram of a vehicle brake device showing an embodiment of the present invention.
FIG. 2 is a schematic block diagram of a vehicle brake device.
FIG. 3 is a map defining a relationship between a master side pressure detector and an average pressure.
FIG. 4 is a map defining the relationship between the pressure difference between the pressure detected by the wheel-side pressure detector and the target sine pressure wave P (t) and the correction amount by the linear pressurization control valve and the linear decompression control valve. is there.
FIG. 5 is a flowchart showing the operation of the brake ECU.
FIG. 6 is a graph showing pressure fluctuations on the wheel cylinder side and sound pressure levels of rotor and pad vibrations.
FIG. 7 is a schematic hydraulic circuit diagram of a vehicle brake device showing another embodiment.
FIG. 8 is a schematic hydraulic circuit diagram of a vehicle brake device according to another embodiment.
[Explanation of symbols]
1 Brake device for vehicles
2 Brake pedal
3 Brake hydraulic circuit
4 Wheel cylinder
10 Normal control circuit
11 Accumulator
13 Linear pressure control valve
17 Linear pressure reducing control valve
20 Master cylinder control circuit
21 Master cylinder
100 brake ECU
103 Brake hydraulic circuit
113 Linear pressure control valve
117 Linear pressure reducing control valve
203 Brake hydraulic circuit
213 Linear pressure control valve
217 Linear pressure reducing control valve

Claims (5)

In a vehicle brake device that adjusts the frictional force between a friction material on the wheel cylinder side and a rotating body on the wheel side by changing the pressure applied to the wheel cylinder of the brake hydraulic circuit according to the depression state of the brake pedal ,
A vehicular brake device comprising frequency control means for controlling the pressure on the wheel cylinder side of the brake hydraulic circuit to fluctuate at a predetermined frequency so as to be intermittently substantially zero. 2. The vehicle brake device according to claim 1, wherein the frequency control unit includes a linear control valve provided between a pressure generation device of a brake hydraulic circuit and a wheel cylinder. 3. The brake hydraulic circuit replaces the normal control circuit unit for transmitting pressure from the pressure generating device corresponding to the depression state of the brake pedal to the wheel cylinder side, and the normal control circuit unit in a predetermined vehicle condition. A master cylinder circuit portion for transmitting pressure from the master cylinder interlocked with the depression of the brake pedal to the wheel cylinder side,
3. The vehicle brake device according to claim 1, wherein the normal control circuit and the master cylinder circuit are connected so that the pressure of the pressure generation device of the normal control circuit is supplied to the master cylinder circuit. 4. . The brake hydraulic circuit controls the wheel cylinders on the left side and the right side of the front axle in synchronization with each other, and controls the wheel cylinders on the right side of the front axis and the left side of the rear axis in synchronization.
3. The pressure fluctuation frequency of the wheel cylinders on the left side of the front shaft and the right side of the rear shaft and the wheel cylinders on the right side of the front shaft and the left side of the rear shaft are shifted by approximately 180 degrees. 4. The vehicle brake device according to 3. The brake hydraulic circuit independently controls the wheel cylinders on the left side of the front shaft, the right side of the front shaft, the left side of the rear shaft and the right side of the rear shaft,
4. The pressure phase of the frequency of pressure fluctuation is shifted by approximately 180 degrees between the left wheel cylinder and the right wheel cylinder, respectively, on the front and rear axles of the vehicle. Vehicle brake system.

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