JPH09267734A - Antilock brake device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically detect and eliminate dew drops produced on the printed circuit board of an electronic control section. SOLUTION: In a machine and electricity integral type ABS device having an actuator section and an electronic control section integrally, a dew drop sensor 4 is provided on the printed circuit board 1 of the electronic control section and humidity information is sent out to the diagnosing circuit 6 of another on-vehicle electronic controller 5 placed in a room. The diagnosing circuit 6 determines a dew drop condition and dew drops are eliminated by supplying a current to the conductive section of the printed circuit board 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antilock braking system (hereinafter also referred to as an antilock brake device or an ABS device) for adjusting a brake pressure in order to secure braking performance and steering stability, and particularly to an actuator section. The present invention relates to an electromechanical integrated antilock brake device in which an electronic control unit and an electronic control unit are integrally provided.

[0002]

2. Description of the Related Art Since the braking performance of a tire is highest on the verge of skid, braking performance and steering stability can be achieved by automatically maintaining the state on the verge of skid. For this reason, ABS devices have been conventionally mounted on automobiles.

As a conventional ABS device, an actuator unit and an electronic control unit are integrated for reasons such as cost reduction, weight reduction, size reduction, and elimination of wire harness.
A so-called electromechanical integrated ABS device is known. FIG.
FIG. 1 is a perspective view showing an example of this type of electromechanical integrated ABS device, and this ABS device generally includes a wheel speed sensor unit 10
1, an electronic control unit 102, and an actuator unit 103
And a warning display unit 104.

In this example, the wheel speed sensor unit 101 is composed of a wheel speed sensor for detecting the rotational speeds of all the left, right, front and rear wheels, and the electronic control unit 102 has four wheel speed sensors 101.
The control circuit sends a command signal to the actuator 103 so as to perform control according to the vehicle speed or the road surface environment based on the output signal of Further, the actuator unit 103 is
It is composed of mechanical components for increasing, holding, and reducing the brake fluid pressure in response to a signal from the electronic control unit 102.

The electronic control unit 102 has a fail-safe (safety function) circuit inside, and monitors each wheel speed sensor 101, the actuator 103, and its own electronic control circuit to detect an abnormality. Then, the ABS function is stopped and the normal braking state is set, and the warning light of the warning display unit 104 provided on the meter in the vehicle compartment is turned on. This allows the occupant to know whether or not the ABS function is working in the current state.

[0006]

However, in such a conventional electromechanical integrated ABS device, the electronic control unit integrated with the actuator unit is installed in the engine room of a vehicle in a severe temperature and humidity environment. Therefore, there is a problem that dew condensation occurs on the printed circuit board of the electronic control unit.

The present invention has been made in view of the above problems of the prior art, and automatically detects the dew condensation on the printed circuit board of the electronic control unit and automatically eliminates it. It is an object of the present invention to provide an antilock brake device that can be used.

[0008]

In order to achieve the above object, an antilock brake device of the present invention according to claim 1 electrically drives an actuator section for mechanically adjusting a brake pressure applied to a wheel. In an electromechanical integrated type anti-lock brake device integrally provided with an electronic control unit for dynamically controlling, at least one dew condensation sensor provided on a printed circuit board constituting the electronic control unit and the dew condensation sensor. And a controller for sending out a heater signal for eliminating the dew condensation on the printed circuit board based on the output signal of the above.

In the anti-lock brake device according to the present invention, the dew condensation sensor is provided on the printed circuit board, and the controller eliminates the dew condensation on the printed circuit board based on the output signal from the dew sensor. Since the signal is sent, even if the electronic control unit is installed outside the vehicle compartment where dew condensation is likely to occur, it can be eliminated and normal control can be executed.

The control unit relating to the antilock brake device according to claim 1 can be incorporated into an electronic control portion of the antilock brake device itself, but the antilock brake device according to claim 2 is the control device. The part is provided in an in-vehicle electronic control device installed in a vehicle compartment.

Since the electronic control unit of the electromechanical anti-lock brake device is provided outside the vehicle compartment, if the control unit is incorporated therein, dew condensation may occur in the control unit. Therefore, if the control unit is incorporated into another electronic control unit in the vehicle compartment as in the antilock brake device according to the second aspect, there is no risk of dew condensation at least in this control unit, and normal control of the electronic control unit is performed. Condensation can be removed. This control unit can be provided independently in the vehicle compartment, but it is more preferable to use an electronic control device installed in almost all vehicles, such as an electronic control device for an airbag and an electronic control device for an engine.

In the antilock brake device according to claim 1 or 2, the specific means for eliminating the dew condensation is not particularly limited, but the antilock brake device according to claim 3 has the control unit on the printed circuit board. It is characterized in that it has a heater portion for eliminating the dew condensation by a heater signal from. This is because dew condensation can be extinguished by the heat generated from the heater section.

In the antilock brake device according to the third aspect, the heater portion provided on the printed circuit board can be separately provided for eliminating the dew condensation.
According to a fourth aspect of the present invention, the anti-lock brake device is characterized in that the heater portion is a conductive paste portion applied on a signal print line of the printed circuit board. Since a conductive paste portion for preventing noise radiated from the input / output signal line of the IC chip is formed on the printed circuit board, it is necessary to separately form a heater portion by using this together with the heater portion. Because there is no.

In the antilock brake device according to any one of claims 1 to 4, the type of the dew condensation sensor is not particularly limited, but in the antilock brake device according to the fifth aspect, the dew sensor has a negative electric resistance characteristic with respect to humidity. It is characterized by comprising a certain humidity sensor. Even if dew condensation occurs on the signal transmission print line of the dew condensation sensor and the output electric resistance value of the dew condensation sensor decreases, the recognition of the humidity based on this decreases the dew condensation. This is because you will not receive it.

[0015]

According to the antilock brake device of the first aspect, even if the electronic control unit is installed outside the vehicle cabin where dew condensation is likely to occur, it can be automatically detected and automatically eliminated. Therefore, normal control of the electronic control unit can be executed.

According to the anti-lock brake device of the second aspect, since the control unit is incorporated in another electronic control unit in the vehicle compartment, there is no risk of dew condensation occurring at least in this control unit, and the electronic control is performed normally. Condensation on the control unit can be removed. Further, if this control unit is incorporated into an electronic control device installed in almost all vehicles such as an electronic control device for an airbag and an electronic control device for an engine, the cost and installation space will be reduced.

According to the third aspect of the antilock brake device, in addition to the effects of the first and second aspects of the invention, dew condensation can be eliminated by the heat generated from the heater portion.

According to the anti-lock brake device of the fourth aspect, since the conductive paste portion for preventing radiation noise formed on the printed circuit board is also used as the heater portion,
There is no need to separately form a heater portion, which is advantageous in terms of cost and space.

According to the fifth aspect of the present invention, even if dew condensation occurs on the signal transmission print line of the dew condensation sensor and the output electric resistance value of the dew condensation sensor decreases, the humidity is recognized based on this. Since it acts in the direction of condensation, it is not adversely affected by condensation.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a plan view showing an embodiment of an anti-lock brake device of the present invention, which is a view for explaining a mounting state of a dew condensation sensor on a printed circuit board, and FIG. 2 is a cross section taken along line AA of FIG. FIG. 3 is a graph showing the electric resistance characteristics of the dew condensation sensor made of nickel ferrite used in the present embodiment with respect to relative humidity, and FIG. 5 is a plan view showing an embodiment of the antilock brake device of the present invention. FIG. 6 is a diagram for explaining FIG.
FIG. 8 is a cross-sectional view taken along line B, and FIG. 8 is a graph showing the relationship between the relative humidity and the supply current to the heater unit in the embodiment of the present invention. The printed circuit board 1 shown in FIG.
The printed circuit board 1 shown in FIG. 1 is the same, and in FIG. 1, mounting components on the printed circuit board 1 are omitted for convenience of description in order to explain the mounting state of the dew condensation sensor.

First, in the antilock brake device of the present embodiment, the actuator section and the electronic control section are integrally formed, and the mechanical-electric integrated ABS arranged in the engine room.
As shown in FIGS. 1 and 5, the device has a printed circuit board 1 which is an electronic control unit.

A connector 2 is provided on one side of the printed circuit board 1 and a ground pattern 3 is formed on the surface thereof. In addition, on the surface of the printed circuit board 1, as shown in FIG. 5, a conductive paste portion 7 made of a copper paste having a thickness of about 20 μm, an IC chip, an input / output signal line 9 of the IC chip 8 and a protective resistor 10. , And the ground line 11 and the like are provided by printing or mounting.

As shown in FIG. 6, an input / output signal line 9 and a ground line 11 are pattern-printed on the surface of the printed circuit board 1 and then a resin material 12 for undercoating is used.
Is applied, and the conductive paste portion 7 is applied to the ground line 11
Formed electrically. Further, the conductive paste portion 7 is covered with a resin material 13 for overcoat.
The conductive paste portion 7 is for suppressing noise radiated from the input / output signal line 9 of the IC chip 8 and is formed so as to cover the input / output signal line 9.
Reference numeral 14 is a pin hole for the lead wire of the element.

As shown in FIG. 5, the conductive paste portion 7
Is connected to the diagnostic circuit 6 of the electronic control unit 5 installed in the vehicle compartment through an electric wire through a protective resistor 10,
An electric current is supplied from the diagnostic circuit 6 to the conductive paste portion 7 based on an output signal from the dew condensation sensor 4 described later. The current supplied to the conductive paste portion 7 is controlled by the diagnostic circuit 6, but a protective resistor 10 is provided just in case.

The electronic control unit 5 is an on-vehicle electronic control device other than the antilock brake device of this embodiment, and is, for example, an airbag control unit or an engine control unit. Although it is possible to incorporate the diagnostic circuit 6 into the electronic control unit of the antilock brake device, in the present embodiment, the diagnostic circuit is used in an in-vehicle electronic control device other than the antilock brake device, particularly in an electronic control device installed in a room. By incorporating 6, the dew condensation is prevented from occurring in the diagnostic circuit 6 itself.

In the antilock brake device of this embodiment, as shown in FIG. 1, three dew condensation sensors 4 are provided on the printed circuit board 1. However, in the antilock brake device of the present invention, at least one dew condensation sensor 4 may be provided on the printed circuit board 1. When a plurality of dew condensation sensors 4 are provided, it is more preferable that the dew condensation sensors 4 are appropriately dispersed and arranged near the connector 2 or apart from the connector 2. This is because the entire dew condensation state on the printed circuit board 1 can be detected. The output signal from the dew condensation sensor 4 is sent to the diagnostic circuit 6 of the electronic control unit 5 installed in the vehicle compartment, and the diagnostic circuit 6 uses the resistance value information sent from the dew condensation sensor 4 to print the printed circuit board 1
The above-mentioned dew condensation state is judged and it is judged whether or not a signal for eliminating the dew condensation is sent to the conductive paste portion 7 which is the heater portion.

Although the specific structure of the dew condensation sensor is not particularly limited, as shown in FIG. 2, for example, a moisture sensitive portion 41 using a magnetite film or a nickel ferrite material, and a moisture sensitive portion 41.
It is composed of an electrode material having excellent adhesion to the material constituting the above and having a small contact resistance, for example, an electrode 42 using a conductive gold paint or the like. The size of the moisture sensitive portion 41 is preferably about 10 mm in length, about 5 mm in width, and about 1 mm in heat.

FIG. 3 is a graph showing the relationship between the electric resistance value of the dew condensation sensor 4 and the humidity characteristic when nickel ferrite is used as the material of the moisture sensitive portion 41. As shown in the figure, in the dew condensation sensor 4, the resistance value of the dew condensation sensor 4 linearly increases as the relative humidity increases. That is, the humidity sensor has a positive electric resistance characteristic with respect to relative humidity.

Next, the operation will be described. FIGS. 7A to 7C
FIG. 3 is a plan view showing a state in which dew condensation has occurred on the printed circuit board 1, and the dew condensation is represented by minute water droplets 15.
(A) shows a state in which dew condensation is relatively small, (B) shows a state in which dew condensation occurs at an intermediate level, and (C) shows a state in which dew condensation occurs almost entirely. In this way, when dew condensation occurs on the printed circuit board 1, the same dew condensation occurs on the dew condensation sensor 4 on the same printed circuit board 1. That is, FIG.
(D)-(F) are plan views showing a state in which dew condensation occurs on the dew condensation sensor 4, (A) and (D), (B) and (E), and (C) and (F), respectively. It corresponds.

Here, when a minute water droplet 15 is generated on the entire surface of the dew condensation sensor 4 as an index of the dew condensation generation state, that is, the water droplet 15 indicated by a shaded circle in FIG. 7D is the entire surface of the dew condensation sensor 4. In the following explanation, the relative humidity is 1
It is set to 00% and 0% when there is no water droplet 15. That is, the ratio of the area occupied by the water droplets 15 to the surface area of the dew condensation sensor 4 is defined as the relative humidity.

In the antilock brake device of the present embodiment, the current characteristic output from the diagnostic circuit 6 of the electronic control unit 5 installed in the passenger compartment is shown in FIG. 8 according to the electric resistance value of the dew condensation sensor 4. Set in advance.

In this example, nickel ferrite is used as the dew condensation sensor 4. Although small water droplets 15 are dispersed on the printed circuit board 1 and some dew condensation occurs (state of FIG. 7A), the insulation resistance between the signal lines 9 on the printed circuit board 1 is, for example, Relative humidity 50%, which is 1 MΩ or more and does not affect the function of the electronic control unit
In the following dew condensation state, that is, when the electric resistance value of the dew condensation sensor 4 is 40Ω or less, no current is supplied from the diagnostic circuit 6 to the heater unit 7 (region 1 in FIG. 8).

Further, the insulation resistance between the signal lines 9 on the printed circuit board 1 becomes 1 MΩ or less.
In the state of (B), when the relative humidity is 50 to 80% in which the influence of dew condensation starts to occur, that is, when the electric resistance value of the dew condensation sensor 4 is 40 to 64Ω, the diagnostic circuit 6
Supplies a current I ₁ from the heater unit 7 to the heater unit 7 (region 2 in FIG. 8).

Further, as shown in FIG. 7C, when the relative humidity is 80 to 100%, that is, the condensation is formed on almost the entire printed circuit board 1, that is, the electricity of the condensation sensor 4 is high. When the resistance value is 64 to 80 Ω, the current I ₂ larger than the current I ₁ is supplied from the diagnostic circuit 6 to the heater unit 7 (region 3 in FIG. 8).

The separation points of the areas 1, 2 and 3 shown in FIG. 8 are determined on the basis of the dew condensation state when the diagnosis circuit 6 starts diagnosis, that is, when the ignition power is turned on to the electronic control unit 5. In this case, the control after the electric current is supplied to the heater unit 7 shifts to the separation point indicated by the alternate long and short dash line in FIG. In this way, by changing the current value supplied to the heater unit 7 between the initial state of dew condensation when the current is applied to the heater unit 7 and the dew condensation state in which the current of the heater unit 7 is applied, It can be reduced.
This is because even if the current value supplied to the heater unit 7 is changed, the temperature of the heater unit 7 does not immediately react and a time delay occurs.

When a current is supplied from the diagnostic circuit 6 to the heater section 7, the conductive paste of the heater section 7 has a resistance of about 20 mΩ per unit area when the thickness of the copper foil is about 20 μm, and the ground line Since the resistance value is about several times higher than 11, the conductive paste portion 7 consumes current and generates heat.
Therefore, the minute water droplets 1 generated on the signal line 9
5 evaporates and disappears as the temperature of the conductive paste portion 7 rises. In particular, since the conductive paste portion 7 is applied on the signal line 9, it has an effect of efficiently heating the signal line 9, and dew condensation and water drops can be eliminated more quickly.

Further, in this embodiment, since the diagnostic circuit 6 is provided not in the electronic control unit of the mechanical / electrical integrated ABS device but in another electronic control unit 5 in the vehicle compartment, dew condensation may occur in the diagnostic circuit 6 itself. There is no problem and normal control can be performed.

The warning lamp 104 is turned on or blinks or fails when the current is being supplied from the diagnostic circuit 6 to the heater section 7, that is, when the printed circuit board 1 of the electronic control section is in a dew condensation state. It's more effective if you work safe.

The embodiments described above are described for facilitating the understanding of the present invention, but not for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

For example, in the above-described embodiment, the moisture sensor 41 is made of nickel ferrite having a positive electric resistance characteristic with respect to relative humidity as the dew condensation sensor 4. However, in the antilock brake device of the present invention, the electric resistance with respect to relative humidity is formed. The moisture sensitive portion 41 can be made of a material having a negative characteristic.

FIG. 4 is a graph showing the electric resistance characteristics of the dew condensation sensor 4 containing zinc oxide and vanadium oxide as main components with respect to the relative humidity. In this dew condensation sensor 4, as shown in FIG. Shows a characteristic in which the electric resistance value linearly decreases as the temperature rises, that is, the electric resistance value with respect to relative humidity is negative.

The use of the dew condensation sensor 4 having such a negative characteristic has the following effects. That is, dew condensation occurs on the signal transmission print line 16 of the dew condensation sensor 4 shown in FIG. 1, and due to this dew condensation, the resistance value output from the dew condensation sensor 4 via the signal transmission print line 16 is detected by the dew condensation sensor 4. Even if the actual electrical resistance value becomes equal to or lower than that, since the relative humidity is 100% or more, it is determined that the dew condensation occurs. Therefore, even if the dew condensation occurs on the signal transmission print line 16, there is no problem in the dew condensation removal control.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of an antilock brake device of the present invention, which is a view for explaining a mounting state of a dew condensation sensor on a printed circuit board.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a graph showing electric resistance characteristics of a dew condensation sensor made of nickel ferrite with respect to relative humidity.

FIG. 4 is a graph showing electric resistance characteristics of a dew condensation sensor containing zinc oxide and vanadium oxide as main components with respect to relative humidity.

FIG. 5 is a plan view showing an embodiment of the antilock brake device of the present invention, and is a view for explaining a heater portion.

FIG. 6 is a sectional view taken along line BB of FIG. 5;

7A to 7C are plan views showing a state in which dew condensation occurs on the printed circuit board, and FIGS. 7D to 7F are plan views showing a state in which dew condensation occurs on the dew condensation sensor. is there.

FIG. 8 is a graph showing the relationship between the relative humidity and the current supplied to the heater unit in the embodiment of the present invention.

FIG. 9 is a perspective view showing a conventional mechanical-electrical integrated ABS device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Printed circuit board (electronic control part) 2 ... Connector 3 ... Ground line 4 ... Dew condensation sensor 41 ... Moisture sensing part 42 ... Electrode 5 ... Electronic control unit (vehicle-mounted electronic control device) 6 ... Diagnostic circuit (control part) 7 Conductive paste portion (heater portion) 8 IC element 9 Input / output signal line 10 Protection resistor 11 Ground line 12 Undercoat 13 Overcoat 14 Pinhole 15 Condensation (fine water droplets) 16 Signal Transmission print line 101 ... Wheel speed sensor 102 ... Electronic control unit 103 ... Actuator unit 104 ... Warning display unit

Claims (5)

[Claims] 1. An electromechanical integrated anti-lock brake device in which an actuator section for mechanically adjusting a brake pressure applied to a wheel and an electronic control section for electrically controlling the actuator section are integrally provided. It has at least one dew condensation sensor provided on a printed circuit board which constitutes a control section, and a control section which sends out a heater signal for eliminating dew condensation on the printed circuit board based on an output signal from the dew condensation sensor. An anti-lock brake device characterized by the above. 2. The antilock brake device according to claim 1, wherein the control section is provided in an in-vehicle electronic control device installed in a vehicle compartment. 3. The antilock brake device according to claim 1, further comprising a heater section on the printed circuit board, the heater section extinguishing dew condensation by a heater signal from the control section. 4. The anti-lock brake device according to claim 3, wherein the heater portion is a conductive paste portion applied on a signal print line of the printed circuit board. 5. The antilock brake system according to claim 1, wherein the dew condensation sensor is a humidity sensor having a negative electric resistance characteristic with respect to humidity.