JPH0597026A - Pressure control device - Google Patents

Abstract

PURPOSE:To reduce noises in a car by giving the time interval of pulse currents such a length that the synthesized wave of a plurality of pressure waves of a solenoid valve device based on the pulse currents does not have the same frequency component as the resonance frequency of either of a plurality of vibrating elements which vibrate on the basis of the synthesized wave of the car. CONSTITUTION:The fundamental pressure change pulse current is in principle divided into two split transform pulse currents and supplied to solenoid-operated direction selecting valves 34, 36, 70, 72. In case the duration Tp of the fundamental transform pulse current is too long when the relationship between the cycle time Tc and pulse interval t1 concerns, the fundamental transform pulse current is as exeption supplied to the direction selecting valves unchangedly. This enables proper setting of the time interval of two pulse currents, and thereby one fundamental wave in the pressure waves based on the foregoing pulse current and one fundamental wave in the pressure waves based on the subsequent pulse current, which both have the same frequency as the frequency of intra-car noises to be reduced, cancel each other, and thus the noises in the car can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure control device provided in a vehicle, and more particularly to a technique for reducing vehicle interior noise generated by the operation of its solenoid valve device.

[0002]

2. Description of the Related Art A pressure control device provided in a vehicle is used for control intended for braking such as antilock control, traction control, and braking effect control, and for other purposes. In the anti-lock control, as described in Japanese Patent Application Laid-Open No. 1-208256 of the present applicant, the brake pressure during vehicle braking is too high in relation to the friction coefficient of the road surface, resulting in an excessive wheel slip ratio. The traction control is a control that prevents the slip ratio of the wheels from becoming excessively large due to the excessive driving force of the wheels during vehicle acceleration, and the braking effect control is the operation of the brake operation member. This control is designed to obtain a braking effect such as vehicle deceleration according to the amount of operation such as force and operation stroke.

And, in one of the pressure control devices of this kind,
An electromagnetic valve device and a pulse current supply means for supplying one pulse current per unit time to the electromagnetic valve device in order to increase or decrease the pressure of the electromagnetic valve device are already known. ing.

[0004]

However, when this pressure control device is operated in a vehicle, an in-vehicle noise is generated due to the operation. Particularly problematic is noise of about 30 to 150 Hz. In view of such circumstances, the present invention has been made to reduce the vehicle interior noise that accompanies the operation of the pressure control device.

[0005]

SUMMARY OF THE INVENTION In order to solve this problem, the present invention provides a solenoid valve device and a solenoid valve device for increasing or decreasing the pressure of the solenoid valve device every unit time. In a pressure control device provided with a pulse current supply means for supplying one pulse current, the pulse current supply means supplies one to the solenoid valve device by dividing one pulse current into a plurality of pulse currents, and , A time interval between the pulse currents, one of a plurality of vibrating elements in which a composite wave of a plurality of pressure waves of an electromagnetic valve device based on the pulse currents vibrates based on the composite wave of a vehicle such as a vehicle body or a suspension. It is characterized in that the length is such that it does not have the same frequency component as the resonance frequency.

[0006]

When, for example, one pulse current shown in FIG. 5A is supplied to the solenoid valve device, the pressure of the solenoid valve device changes as shown in the graph of FIG. 5B, for example. This pressure wave can be considered to be a composite wave of a plurality of fundamental waves, and the frequency characteristic of the pressure wave is represented by the graph of FIG. At this time, when the pressure is represented by a function g (t) of time t, the complex Fourier transform G (ω) of the function g (t), that is, the function G of the angular frequency ω representing the frequency characteristic of pressure.
(Ω) is as follows. G (ω) = ∫g (t) e ^−jwt dt Here, for example, as in the example shown in FIG. 1, two pulse currents having the same height and the same duration are applied to the solenoid valve device at a time interval t _1. assuming fed, pressure generated electromagnetic valve device at that time is represented by g (t) + g (t -t 1), it if Fourier transform, a G (ω) (1 + e -jwt1) .. Here, 1 + e ^−jwt1 is ωt ₁ = ± π, ± 3
When it is π, ..., It becomes 0, and the component of frequency f does not exist in the pressure wave of the solenoid valve device. Therefore, the vehicle body,
The resonance frequency of one of a plurality of vibration elements of a vehicle such as a suspension that vibrates based on the pressure wave, that is, the frequency of vehicle interior noise to be reduced is f _0.
When expressed as t ₁ = 1 / [2f ₀ ], 3 / [2f ₀ ] ,.
.., the pressure wave of the solenoid valve device does not have a component of frequency f ₀ .

Assuming that three pulse currents having the same height and the same duration are supplied to the solenoid valve device at time intervals t ₁ , the pressure generated in the solenoid valve device at that time is g (t) + g. It is represented by (t−t ₁ ) + g (t−2t ₁ ), and if it is Fourier transformed, it becomes G (ω) (1 + e ^−jwt1 + e ^−2jwt1 ). Here, 1 + e ^−jwt1 + e ^−2jwt1 is ωt ₁ =
It becomes 0 when ± 2π / 3, ± 4π / 3, ....
Therefore, when the frequency of the vehicle interior noise to be reduced is represented by f ₀ , t ₁ = 1 / [3f ₀ ], 2 / [3f ₀ ], ...
Then, the pressure wave of the solenoid valve device does not have a component of frequency f ₀ .

Based on these facts, in the pressure control device according to the present invention, one pulse current is divided into a plurality of pulse currents and supplied to the solenoid valve device, and the time intervals between the pulse currents are: A length in which a composite wave of a plurality of pressure waves of the solenoid valve device based on the pulse current does not have a component of the same frequency as the resonance frequency of any of the vibration elements of the vehicle body, suspension, or other vehicle that vibrate based on the composite wave. To be done. A plurality of pressure waves based on a plurality of pulse currents are generated by canceling out a plurality of fundamental waves having the same frequency as the resonance frequency of the vibrating element. That is, the composite wave of does not have a fundamental wave having the same frequency as the resonance frequency of the vibrating element.

[0009]

Therefore, according to the present invention, the pressure control device does not act as the vibration source of the vibration element, and the noise in the vehicle can be effectively reduced. Moreover, since the object can be achieved by adding a simple computer program or an electronic circuit, the cost of the device can be reduced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a brake fluid pressure control device of an antilock type hydraulic brake device will be described in detail below with reference to the drawings. In FIG. 2, reference numeral 10 denotes a brake pedal of a four-wheeled vehicle, and a brake pedal 1
When 0 is depressed, the master cylinder 12 is activated. The master cylinder 12 is a tandem type having two pressurizing chambers that are independent of each other, and generates a hydraulic pressure of the same height in each pressurizing chamber according to the depression operation of the brake pedal 10.

The hydraulic pressure generated in one of the pressurizing chambers passes through the dual proportioning valve 14 from the main hydraulic passage to the front wheel cylinder 20 and the rear wheel cylinder 22 of a brake provided on the right front wheel 16 and the left rear wheel 18, respectively. Is supplied to. The hydraulic pressure generated in the other pressurizing chamber is divided into two parts by the joint member 24, one is supplied to the front wheel cylinder 28 of the brake of the left front wheel 26, and the other is supplied to the dual proportioning valve 14
Rear wheel cylinder 3 for the brake of the right rear wheel 30
2 is supplied.

The dual proportioning valve 14 includes two proportioning valves for reducing the hydraulic pressure supplied from the master cylinder 12 at a constant ratio, and the hydraulic pressure supplied to the front wheel cylinders 20 and 28 is not reduced. The hydraulic pressures supplied to the rear wheel cylinders 22 and 32 are reduced.

In this brake device, each wheel 16,
18, 26 and 30 are antilock-controlled independently of each other. The right front wheel-left rear wheel system will be representatively described below. Electromagnetic directional control valves 34, 36 are provided in the middle of the main fluid passage connecting the master cylinder 12 and the wheel cylinders 20, 22 of the right front wheel 16 and the left rear wheel 18, respectively.
As a result, the main liquid passages become the master cylinder side passages 38, 39.
And the wheel cylinder side passages 40 and 42. Between the master cylinder side passages 38, 39 and the wheel cylinder side passages 40, 42, return passages 44,
46 is connected to each of the return passages 44 and 46, which allows the flow of the brake fluid from the wheel cylinder side passages 40 and 42 to the master cylinder side passages 38 and 39, but prevents the reverse flow of the brake fluid. Stop valves 48, 50 are provided.

A reservoir 58 is connected to the electromagnetic direction switching valves 34, 36 via reservoir passages 54, 56. The electromagnetic direction switching valves 34, 36 are supplied to the wheel cylinders 20 from the master cylinder 12 by supplying brake fluid. , 22
Each wheel cylinder 2 and the increased pressure state that increases the hydraulic pressure of
It is possible to switch between a reduced pressure state in which the hydraulic pressure is reduced by discharging the brake fluid from 0, 22 to the reservoir 58 and a holding state in which the hydraulic pressure is kept constant without communicating the wheel cylinders 20, 22 with any of them. is there.

The brake fluid discharged from the wheel cylinders 20 and 22 and stored in the reservoir 58 is stored in the check valve 60.
Is pumped up by a pump 62 having a pump passage 6
It is supplied to the master cylinder side passages 38, 39 via 4, 65. The pump 62 is driven by a pump motor 66. The pump 62 also includes a check valve 68 that prevents the reverse flow of brake fluid from the master cylinder side passages 38, 39 to the pump 62.

Although the right front wheel-left rear wheel system has been described above, the left front wheel-right rear wheel system has the same structure.
Individual electromagnetic direction switching valves 70, 72, master cylinder side passages 74, 75, wheel cylinder side passages 76, 78, return passages 80, 82, check valves 84, 86, reservoir passage 8
9, 90, reservoir 92, pump 94, pump passage 9
6, 97 and check valves 98, 100. The pump 94 is driven by a pump motor 66 like the pump 62, and the pumps 62, 94, the pump motor 66, and the master cylinder 12 constitute a hydraulic pressure source. Further, the reservoirs 58 and 92 function as tanks.

The wheel speeds of the right front wheel 16, the left rear wheel 18, the left front wheel 26, and the right rear wheel 30 are respectively measured by the wheel speed sensor 10.
It is detected by 2, 104, 106 and 108, and is supplied to the slip ratio computing unit 110. The slip ratio calculation unit 110 calculates the wheel speed, the wheel deceleration, the vehicle body speed, the slip ratio, etc., and the antilock control unit 112 causes the electromagnetic direction switching valves 34, 36, 70, 72 to calculate based on the calculation results. Is switched to keep the slip ratio of the wheel within an appropriate range.

The antilock control unit 112 is shown in FIG.
As shown in, CPU116, ROM118, RAM1
The main component is a computer having 20 and a bus 122 for connecting them, and the ROM 118 stores various control programs including an antilock control routine. An input interface 124 is connected to the bus 122, and the input interface 12
4, a slip ratio computing unit 110, a brake switch 126 for detecting depression of the brake pedal 10, an ignition switch 130, etc. are connected. An output interface 136 is also connected to the bus 122. The output interface 136 has a drive circuit 138,
Electromagnetic directional control valves 34, 36, 70, 72, pump motor 66, etc. are connected via 140, 142, 144, 146.

The operation will be described below. In the slip ratio computing unit 110, the ignition switch 130 is turned on.
While in the N state, calculations such as the slip ratio are repeatedly executed based on the signals from the wheel speed sensors 102 to 108, while the antilock control unit 112 controls the antilock control while the brake switch 126 is in the ON state. I do. When the slip ratio calculated by the slip ratio calculating unit 110 becomes excessive in any wheel, the hydraulic pressure of the wheel cylinder of the brake provided on that wheel is duty-controlled to keep the slip ratio in an appropriate range. Of.

The duty control is a cycle time T
Whether the hydraulic pressure of the wheel cylinder is reduced or increased based on the wheel speed, the wheel deceleration, the vehicle body speed, the slip ratio, etc. for each _c (this is one aspect of the “unit time” in the present invention), Or, decide whether to keep the height as it is, and in the case of pressure reduction and pressure increase, pressure reduction pulse current and pressure increase pulse current to be supplied to the electromagnetic directional control valve that controls the wheel cylinder (hereinafter, divided pressure reduction pulse to be described later). The basic pressure reducing pulse current and the basic pressure increasing pulse current are referred to as the dividing pressure reducing pulse current and the dividing pressure increasing pulse current, respectively, in relation to the current and the dividing pressure increasing pulse current. Current and basic boosting pulse current are collectively referred to as basic transformer pulse current). And controls the hydraulic pressure in the eel cylinder. However, in each duty control, the pressure reduction or pressure increase is not performed at once, that is, the basic transformation pulse current is not directly supplied to the electromagnetic directional control valve, but as in the example shown in FIG. , Two divided transformer pulse currents of the same duration are supplied. Moreover, the time interval (hereinafter, simply referred to as pulse interval) t ₁ of the divided transformer pulse currents is considered to be the pressure wave when the previous divided transformer pulse current is supplied to the electromagnetic directional control valve as a composite wave of a plurality of fundamental waves. Out of those fundamental waves,
The suspension having the largest amplitude among the plurality of vibration elements of the vehicle that vibrate based on the pressure wave of the electromagnetic directional control valve (this is the "any of the plurality of vibration elements" in the present invention).
A fundamental frequency having the same frequency as the resonance frequency f ₀ ) and a fundamental wave having the same frequency as the resonance frequency f ₀ among the pressure waves based on the divided transformer pulse currents to be canceled later. It is said that.

FIG. 4 is a flow chart showing a part of the antilock control routine relating to the duty control. The duty control will be described with reference to this figure. First, step S1 (hereinafter, simply S
1 In other steps the same), the duration T _p of the basic transformer pulse current is calculated, and subsequently,
In S2, it is determined whether or not the duration T _p is less than or equal to the pulse interval t ₁ , that is, whether or not the previous divided transformer pulse can be extinguished by the start of rising of the subsequent divided transformer pulse. It If this is the case this time, the determination is YES, and in S3, it is determined whether the sum of the duration T _p and the pulse interval t ₁ is less than or equal to the cycle time T _c , that is, the duty control of this time. By the end it is determined whether the later split transformer pulses can be extinguished. Assuming this is the case this time,
The determination is YES, and in S4, in the current duty control, it is determined that the basic transformer pulse current should be divided into two divided transformer pulse currents and supplied to the electromagnetic directional control valve.

On the other hand, if the duration T _p is longer than the pulse interval t ₁ , the determination in S2 is NO, and the duration T _p is less than the pulse interval t ₁ but is equal to the duration T _p . If the sum of the pulse interval t ₁ is longer than the cycle time T _c , the determination in S3 is NO, and in S5, the basic transformer pulse current should be supplied to the electromagnetic directional control valve as it is in the current duty control. It is determined that

That is, in principle, the basic transformer pulse current is divided into two divided transformer pulse currents and supplied to the electromagnetic directional control valve. The duration T _p of the basic transformer pulse current is the cycle time T _c and In the case where it is too long in relation to the pulse interval t ₁ , the exception is that the basic transformer pulse current is supplied as it is to the electromagnetic directional control valve.

As described above, one pulse current that should otherwise be supplied to the electromagnetic directional control valve is divided into two pulse currents, and the time interval between these two pulse currents is increased. By properly setting, one fundamental wave in the pressure wave based on the preceding pulse current and one fundamental wave in the pressure wave based on the subsequent pulse current should be reduced together. Those having the same frequency as the in-vehicle noise cancel each other out, so that the in-vehicle noise can be effectively reduced.

As is clear from the above description, in this embodiment, the electromagnetic directional control valves 34, 36, 70, 72,
The reservoirs 58, 92, the pumps 62, 94, the wheel speed sensors 102, 104, 106, 108, the slip ratio computing unit 110, the antilock control unit 112, etc. constitute an antilock control device. Is an example of the pressure control device of the present invention. The antilock control unit 112 constitutes pulse current supply means, and the electromagnetic directional control valves 34, 3 are provided.
The solenoid valves 6, 70 and 72 each independently constitute a solenoid valve device.

However, the solenoid valve device can be constructed by combining a plurality of solenoid valves, for example, by connecting the pressure increasing solenoid opening / closing valve and the pressure reducing solenoid opening / closing valve in parallel. Further, in the present embodiment, the divisional supply of the pulse current is realized by software by adding a special routine to the control program of the computer, but it can be realized by hardware by adding an electronic circuit. Is also possible.

Further, although the present embodiment applies the present invention to an antilock control device of a type that always performs duty control in antilock control, it can also be applied to a type that temporarily performs duty control. ..

Further, in the present embodiment, the present invention is applied to the brake hydraulic pressure control device of the anti-lock type hydraulic brake device, but the pressure control for vehicle braking such as the traction control device and the braking effect control device is performed. It is also possible to apply the present invention to a device or a pressure control device for other purposes. In addition, the present invention can be implemented in various modified and improved modes without departing from the spirit of the present invention.

[Brief description of drawings]

FIG. 1 is a diagram for explaining divided supply of a pulse current in an antilock control device that is an embodiment of the present invention.

FIG. 2 is a circuit diagram of a hydraulic brake device including the antilock control device.

FIG. 3 is a block diagram of an antilock control unit in the antilock control device.

FIG. 4 is a flowchart for explaining how a pulse current is supplied in the antilock control device.

FIG. 5 is a graph for explaining the principle used by the present invention to solve the problem of reducing vehicle interior noise.

[Explanation of symbols]

 12 Master Cylinder 20, 28 Front Wheel Cylinder 22, 32 Rear Wheel Cylinder 34, 36, 70, 72 Electromagnetic Directional Change Valve 58 Reservoir 112 Antilock Control Unit 138, 140, 142, 144 Drive Circuit

Claims (1)

[Claims] 1. A solenoid valve device provided in a vehicle, and a pulse current supply for supplying one pulse current per unit time to the solenoid valve device for increasing or decreasing the pressure of the solenoid valve device. In the pressure control device, the pulse current supply means divides the one pulse current into a plurality of pulse currents and supplies the plurality of pulse currents to the solenoid valve device, and a time interval between the pulse currents. A component having the same frequency as the resonance frequency of any of a plurality of vibrating elements in which a composite wave of a plurality of pressure waves of the solenoid valve device based on the pulse current vibrates based on the composite wave of the vehicle such as a vehicle body and a suspension. A pressure control device characterized in that the length is set so as not to have.