JPH07112657A - Electronic control device with acceleration detector - Google Patents

Abstract

PURPOSE:To provide an electronic control device with an acceleration detector requiring no noise countermeasure, capable of reducing the installation space, and easy to calibrate the characteristic of the acceleration detector. CONSTITUTION:An electronic control device 1 is mounted with many electronic parts including an acceleration detector 2 on a circuit board 3, the circuit board 3 is fixed to a bottom plate 4 made of a metal, and a metal case 5 is covered on it. The electronic control device 1 controls a hydraulic circuit based on the acceleration of an automobile detected by the acceleration detector 2 and the revolving speed of wheels detected by a revolving speed sensor, adjusts the brake pressure, and performs brake control so that the wheels are not locked. The acceleration detector 2 is manufactured via the application of silicon micro-machine technique, for example, and it is miniaturized to the level that it can be sufficiently stored in the electronic control device 1. Since the acceleration detector 2 is covered by the metal bottom plate 4 and the metal case 5, it is not affected by the electromagnetic noise of an automobile.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic control device for braking a moving body, and more particularly to an electronic control device with an acceleration detector provided with an acceleration detector for detecting the acceleration of the moving body.

[0002]

2. Description of the Related Art In recent years, an ABS has been used to perform braking control so that wheels are not locked when a vehicle brake is applied.
(Anti-Lock Brake System) is popular. This AB
In S, a rotation speed sensor that detects the rotation speed of the wheel, an acceleration detector that detects the acceleration of the automobile, an electronic control device, etc. are provided, and the electronic control device is the wheel detected by the rotation speed sensor and the acceleration detector. The brake pressure is adjusted based on the rotation speed of the vehicle and the acceleration of the vehicle to control the braking of the vehicle.

Here, as the acceleration detector, there is, for example, one described in Japanese Patent Application No. 4-2203. This acceleration detector includes a bobbin around which a coil is wound, a magnetic body that passes through the center of the bobbin, and two leaf springs that support both ends of the magnetic body. The magnetic body is displaced according to acceleration,
When the magnetic field changes, the change in the magnetic field is detected by the coil, and the acceleration is obtained from the output of the coil.

Due to the structure of this acceleration detector, it is difficult to reduce its size. On the other hand, the above electronic control device tends to be downsized. Therefore, as a matter of course, the acceleration detector and the electronic control device are separated without incorporating the acceleration detector into the electronic control device.

Further, since the direction of acceleration detected by the acceleration detector is made to coincide with the moving direction of the automobile, it is necessary to provide the mounting angle of the acceleration detector with an appropriate degree of freedom. Therefore, mounting the acceleration detector requires a sufficient space, which makes it difficult to incorporate the acceleration detector into the electronic control unit.

[0006]

However, when the acceleration detector and the electronic control unit are separated, the following drawbacks occur.

(1) As shown in FIG. 9, an electronic control unit 10
1 requires the harness 103 to connect the acceleration detector 102. Therefore, in an automobile in which a lot of electromagnetic noise is generated, noise is picked up by the harness, and this noise affects the detection output of the acceleration detector. Therefore, the harness is electromagnetically shielded and the acceleration detector is provided with a noise filter, resulting in an increase in the number of parts and an increase in cost.

(2) In order to install the acceleration detector and the electronic control unit, each space and each mounting fitting are required.

(3) Since a plurality of acceleration detectors and a plurality of electronic control units are arbitrarily combined in the mass production process,
It has been necessary to make the characteristics of these acceleration detectors uniform and reduce variations in braking control.

By the way, a small acceleration detector has been developed by recent electronic technology. For example, Japanese Patent Laid-Open No. 5-
No. 149968 discloses a small acceleration detector called a "semiconductor sensor". By incorporating such a small acceleration detector in the electronic control unit, the above-mentioned drawbacks can be solved at once.

Therefore, an object of the present invention is to integrate an acceleration detector and an electronic control device, and a device for this integration, thereby providing an electronic control device with an acceleration detector having many advantages. To do.

[0012]

In order to solve the above-mentioned problems, the present invention controls a braking means for braking a moving body based on a detection output of an acceleration detector for detecting the acceleration of the moving body to move the moving body. In an electronic control device for controlling body braking, an acceleration detector is attached to the electronic control device, and a conductive portion connecting the acceleration detector and the electronic control device is housed in a metal casing of the electronic control device.

The acceleration detector is mounted on a circuit board of the electronic control unit or attached to a metal casing of the electronic control unit.

The acceleration detector is attached to the electronic control unit via a support, and the acceleration detector is supported in a state where the moving direction of the moving body and the direction of the acceleration detected by the acceleration detector match.

The acceleration detector is preferably connected to the circuit board of the electronic control unit via a flexible board.

It is preferable that the electronic control unit be provided with a calibration means for calibrating the detection output of the acceleration detector.

A failure diagnosis means for diagnosing a failure of the acceleration detector may be provided in the electronic control unit.

[0018]

According to the present invention, the acceleration detector is attached to the electronic control unit, and the conductive portion connecting the acceleration detector and the electronic control unit is housed in the metal casing of the electronic control unit. It is not affected by picked-up noise and does not require parts for noise suppression. Further, since the acceleration detector and the electronic control device are integrated, in order to install the acceleration detector and the electronic control device,
Only one space and one mounting bracket are required.

If the acceleration detector is mounted on the circuit board of the electronic control unit, the connection between the acceleration detector and the electronic control unit is most simplified, and if the acceleration detector is attached to the metal casing of the electronic control unit, The circuit board of the electronic control device need not be upsized.

If the acceleration detector is attached to the electronic control unit via the support in a state where the direction of the acceleration detected by the acceleration detector matches the moving direction of the moving body, the acceleration can be accurately detected.

If the acceleration detector is connected to the circuit board of the electronic control unit via the flexible board, the direction of the acceleration detector can be easily adjusted and the acceleration detection direction can be easily matched with the moving direction of the moving body. it can.

Since the combination of the acceleration detector and the electronic control device is determined, the electronic control device is provided with a calibration means for calibrating the detection output of the acceleration detector, and the calibration of the characteristics of the acceleration detector by the calibration means is once set. Then, constant braking control becomes possible.

If the electronic control unit is provided with a failure diagnosing means for diagnosing a failure of the acceleration detector, it is not necessary to connect the electronic control apparatus to an external device via a harness for diagnosing the failure.

[0024]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an embodiment of an electronic control unit according to the present invention. An electronic control unit (hereinafter referred to as an ECU) 1 of this embodiment mounts a large number of electronic components including an acceleration detector 2 on a circuit board 3, fixes the circuit board 3 to a metal bottom plate 4, and The metal case 5 is covered from above. A pair of brackets 6 are fixed to both sides of the bottom plate 4, and the ECU 1 is attached by inserting respective screws into the small holes of the brackets 6 and screwing these screws into a predetermined member.

The ECU 1 is applied to, for example, an ABS of an automobile. The ECU 1 includes an acceleration of the vehicle detected by the acceleration detector 2 and a rotation speed sensor (not shown).
Based on the rotation speed of the wheel detected by, the hydraulic circuit (not shown) is controlled, the brake pressure is adjusted, and the braking control is performed so that the wheel does not lock.

The acceleration detector 2 is manufactured by applying, for example, a silicon micromachine technique, and is miniaturized so as to be sufficiently contained in the ECU 1. This acceleration detector 2
It is mounted on the circuit board 3 of the CU 1, and the circuit board 3 is covered with a metal bottom plate 4 and a metal case 5. Therefore, the acceleration detector 2 is not affected by the electromagnetic noise of the automobile. Also, unlike the conventional method, it is not necessary to connect the ECU and the acceleration detector via a harness, electromagnetically shield this harness, or attach a noise filter to the acceleration detector, thus reducing the number of parts and increasing the cost. Can be realized.

Further, since it is not necessary to mount the ECU 1 and the acceleration detector 2 separately, it suffices to secure only the space for mounting the ECU 1. Further, the bracket 6 of the ECU 1 allows the acceleration detector 2 together with the ECU 1.
Since it is attached to the body or chassis of the automobile, there is no need for a mounting bracket for mounting the acceleration detector 2.

As shown in FIG. 2, the acceleration detector 2 is EC
It may be fixed to the outer wall surface of the U1 metal case 5. In this acceleration detector 2, the detector itself is covered with a metal case, and a plurality of terminal pins project from the bottom of the detector,
These terminal pins penetrate the metal case 5 of the ECU 1 and are connected to the circuit board 3. Therefore, similarly to the device of FIG. 1, the acceleration detector 2 is not affected by the electromagnetic noise of the automobile. Further, since the acceleration detector 2 is not mounted on the circuit board 3, the circuit board 3 does not need to be upsized, and the existing circuit board can be used as it is.

As shown in FIG. 3, the acceleration detector 2 may be attached to the L-shaped support 7, and the L-shaped support 7 may be fixed to the circuit board 3. The flat plates 7a and 7b of the L-shaped support 7
Angle θ is predetermined, and the flat plate 7a of the L-shaped support 7 is fixed on the circuit board 3 in a predetermined direction. As a result, the direction in which the acceleration detector 2 detects the acceleration is determined on the circuit board 3.

If the ECU 1 is attached to the body or chassis of an automobile and the ECU 1 is fixed in a predetermined posture, the direction of acceleration detection by the acceleration detector 2 is determined. Therefore, it is possible to match the acceleration detection direction of the acceleration detector 2 with the traveling direction of the automobile and detect the acceleration in the traveling direction.

As shown in FIG. 4, the acceleration detector 2 can be attached by using the heat dissipation plate 9 of the electronic element 8 instead of the L-shaped support 7 described above. In this case, since it is not necessary to provide the L-shaped support 7, it is not necessary to increase the number of parts. Of course, the angle and direction of the heat sink 9 are appropriately determined.

FIG. 5 and FIG. 6 show how the acceleration detector 2 is connected.

In FIG. 5, each terminal pin 2a of the acceleration detector 2 is appropriately bent, and these terminal pins 2a are connected to the circuit board 3.

In FIG. 6, the acceleration detector 2 is connected to the L
The acceleration detector 2 is fixed to the mold support 7 and is connected to the circuit board 3 via the flexible board 11. Since the flexible board 11 has flexibility, the circuit board 3
Even if the acceleration detector 2 is attached at any angle and direction, the connection process can be performed quickly.

Of course, even when the acceleration detector 2 is fixed to the metal case 5 or the heat dissipation plate 9, the connection may be made via the flexible substrate 11.

Next, since the acceleration detector 2 is incorporated in the ECU 1, the characteristics of the acceleration detector 2 can be easily calibrated.

For this calibration, tilt the ECU 1
The acceleration detection direction of the acceleration detector 2 is made to coincide with the gravitational acceleration direction, and the detection output of the acceleration detector 2 at this time is sampled. Subsequently, the acceleration detection direction of the acceleration detector 2 is made horizontal, and the detection output of the acceleration detector 2 when the acceleration is “0” is sampled. The detection output of the acceleration detector 2 at this time is sampled by reversing the direction. That is, 1G, 0G, -1G (G
= 9.8 m / s ² ) The detection output of the acceleration detector 2 is sampled for each acceleration.

This sampling is performed by a central processing unit (hereinafter referred to as CPU) built in the ECU 1, and the detection output of each is stored in the CPU. Here, if the output characteristic of the acceleration detector 2 with respect to the acceleration is represented by the alternate long and short dashed line B in the graph of FIG. 7, the CPU stores the data corresponding to the alternate long and short dashed line B.

The CPU obtains the offset voltage and the sensitivity for calibrating the alternate long and short dash line B to the solid line A representing a predetermined standard characteristic as calibration values. This offset voltage is a voltage applied to the acceleration detector 2. Further, this sensitivity is determined by the amplification factor of the detection output of the acceleration detector 2.

The CPU sets these offset voltages and sensitivities, and thereby calibrates the output characteristic of the acceleration detector 2 from the one represented by the alternate long and short dash line B to the standard one represented by the solid line A.

If such a calibration is performed, the output characteristics of the acceleration detector need not be constant, so that the mass productivity of the acceleration detector is improved and the cost can be reduced.

Note that the calibration may be performed by another method. For example, if the data corresponding to the one-dot chain line B which is the output characteristic of the acceleration detector 2 is stored, the acceleration corresponding to the detection output of the acceleration detector 2 can be obtained by referring to this data.

By the way, even when the acceleration detector and the electronic control unit are separately installed as in the conventional case, it is possible to calibrate the detection output of the acceleration detector. In this case, based on the procedure of deciding the combination of the acceleration detector and the electronic control device, calibrating the output characteristics of the acceleration detector, and then mounting the acceleration detector and the electronic control device in the vehicle,
Since it is necessary to manage the combination of the acceleration detector and the electronic control device until it is mounted on the vehicle, the assembly process and parts management become complicated. On the other hand, in this embodiment, since the ECU 1 and the acceleration detector 2 are integrated,
The assembly process and parts management are not complicated.

Next, as shown in FIG. 8, the acceleration detector 2 is provided with a failure diagnosis terminal 2b, and the failure of the acceleration detector 2 is diagnosed on the circuit board 3. Here, a failure diagnosis signal is applied from the CPU 12 to the failure diagnosis terminal 2b, and the failure diagnosis is performed by the CPU 12 based on the detection output of the acceleration detector 2.

In this case, since it is not necessary to connect the ECU 1 to the external device via the harness for diagnosing the failure of the acceleration detector, the cost is not increased and the maintenance management is improved. Further, since the failure is diagnosed inside the ECU 1, it is not affected by electromagnetic noise. Therefore, the electronic control device according to the present invention is suitable for an acceleration detector having a failure diagnosis terminal.

[0047]

As described above, according to the present invention, the acceleration detector is attached to the electronic control unit, and the conductive portion connecting the acceleration detector and the electronic control unit is housed in the metal casing of the electronic control unit. There is. Therefore, a harness for connecting the acceleration detector and the electronic control device is not needed, and the influence of noise is eliminated. Further, since the acceleration detector and the electronic control device are installed, only one space and one mounting bracket are required. Furthermore, since the combination of the acceleration detector and the electronic control device is determined, the characteristics of the acceleration detector can be easily calibrated.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of an electronic control device according to the present invention.

FIG. 2 is a perspective view showing an example of arrangement of acceleration detectors in the electronic control device of FIG.

3 is a perspective view showing another example of the arrangement of the acceleration detectors in the electronic control unit of FIG.

FIG. 4 is a perspective view showing another example of arrangement of acceleration detectors in the electronic control unit of FIG. 1.

5 is a perspective view showing an example of a connection mode of an acceleration detector in the electronic control device of FIG.

6 is a perspective view showing another example of the connection mode of the acceleration detector in the electronic control device of FIG.

FIG. 7 is a chart showing output characteristics of an acceleration detector with respect to acceleration.

FIG. 8 is a diagram showing a modification of the electronic control unit of FIG.

FIG. 9 is a diagram showing a conventional electronic control device and an acceleration detector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electronic control device 2 Acceleration detector 3 Circuit board 4 Bottom plate 5 Metal case 6 Bracket 7 L-shaped support tool 8 Electronic element 9 Heat sink 11 Flexible board 12 Central processing unit

Claims (11)

[Claims] 1. An electronic control device for controlling a braking means for braking a moving body based on a detection output of an acceleration detector for detecting an acceleration of the moving body to control the braking of the moving body. An electronic control unit with an acceleration detector, in which a conductive part for connecting the acceleration detector and the electronic control unit is housed in a metal casing of the electronic control unit. 2. The electronic control device with an acceleration detector according to claim 1, wherein the acceleration detector is mounted on a circuit board of the electronic control device. 3. The electronic control device with an acceleration detector according to claim 1, wherein the acceleration detector is attached to a metal casing of the electronic control device. 4. The acceleration detector is attached to an electronic control unit via a support, and the support has a moving direction of a moving body and an acceleration detected by the acceleration detector in the same direction. The electronic control unit with an acceleration detector according to claim 1, which supports the acceleration detector. 5. The electronic control device with an acceleration detector according to claim 4, wherein the support is a heat radiating plate that radiates heat of electronic components of the electronic control device. 6. The electronic control device with an acceleration detector according to claim 1, wherein the terminal pin of the acceleration detector is directly connected to the circuit board of the electronic control device. 7. The electronic control device with an acceleration detector according to claim 1, wherein the acceleration detector and the circuit board of the electronic control device are connected via a flexible substrate. 8. The electronic control unit comprises a calibration means for calibrating the detection output of the acceleration detector with respect to the acceleration.
An electronic control unit with an acceleration detector according to. 9. The acceleration detector according to claim 8, wherein the calibration means calibrates the detection output of the acceleration detector by adjusting the offset voltage applied to the acceleration detector and the sensitivity of the acceleration detector. Electronic control unit. 10. The electronic control device with an acceleration detector according to claim 9, wherein the calibration means obtains a calibration value from a detection output of the acceleration detector when a known gravitational acceleration is applied. 11. The electronic control device with an acceleration detector according to claim 1, further comprising a failure diagnosing means for diagnosing a failure of the acceleration detector.