JPH06109758A - Acceleration sensor - Google Patents

Abstract

PURPOSE:To enable a break to be detected, regarding the thin wall section of an acceleration detecting probe, by providing a break detection wiring means on the probe in such a way as reaching the vicinity of a weight across the thin wall section from the side of a seat, and again returning to the side of the seat. CONSTITUTION:An acceleration detecting probe 1 flexes, when exposed to acceleration. Thus, the acceleration concentrates upon a thin wall section 2, and matching balance between the resistance values of each gauge resistor constituting a bridge circuit is lost, due to the piezoresistance effect of gauge resistors. An electrical signal corresponding to a change in the balance is, therefore, taken out externally via a wiring means 12, a wire and a lead pin, and the acceleration is thereby measured. The thin wall section 2 may be broken, upon exposure to a large impact. In this case, a thin wall section break detecting wiring means 13 is laid in such a way as crossing the entire breadth of the section 2 and, therefore, a break at any position leads to the break of the means 13. Thus, the break of the probe 1 can be detected simply by checking the electrical continuity of two lead pins 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acceleration detecting device used for suspension control, ABS, etc. for automobiles.

[0002]

2. Description of the Related Art FIG. 5 is a cross-sectional view showing a conventional acceleration detecting device. In the drawing, reference numeral 1 denotes a semiconductor device having a circuit in which a gauge resistance as a piezoelectric element exhibiting a piezoresistive effect is wired in a bridge shape. The acceleration detecting beam 2 for converting the generated acceleration into a voltage is a thin portion provided in the acceleration detecting portion A of the acceleration detecting beam 1 in order to concentrate the applied acceleration and improve the sensitivity. The acceleration detecting section A is composed of a piezoelectric element P and a wiring means 12 for connecting them in a bridge.

Further, since 3 has a cantilever structure, a pedestal as a support for supporting the end of the acceleration detecting beam 1 and a weight 4 attached to the end of the acceleration detecting beam 1 opposite to the pedestal 3. Reference numeral 5 denotes a base portion of the exterior of the acceleration detection device, 6 denotes a cap portion of the exterior of the acceleration detection device, and the cap portion 6 and the base portion 5 form a case C. Numeral 7 draws out the electric signal whose acceleration is converted to the outside of the exterior,
In addition, it is a lead pin that draws an input voltage.

Further, 8 is a wire for electrically connecting the acceleration detecting beam 1 and the lead pin 7, 9 is a viscous oil enclosed in the acceleration detecting device for improving impact resistance, and 10 is an oil. A sponge having closed cells attached to the cap portion 6 for absorbing the thermal expansion of 9 to prevent the exterior from being deformed, and an adhesive 11 for attaching the sponge 10 to the cap 6.

6 and 7 are a plan view and a partially cutaway front view of the acceleration detection beam 1, in which reference numeral 12 is an acceleration by electrically connecting a piezoelectric element P to a bridge. Wiring means for forming the detection unit A,
It is provided on the acceleration detection beam 1. t is a region in the thin portion 2 where the wiring means 12 does not exist.

Next, the operation will be described. First, when acceleration is applied to an acceleration detection device mounted on a vehicle,
Upon receiving this acceleration, the acceleration detection beam 1 bends. For this reason, the stress resulting from this bending concentrates on the thin portion 2, and the piezoresistive effect of the gauge resistance causes the balance of the resistance values of the cage resistances constituting the bridge circuit to be lost. Therefore, an electric signal corresponding to the change in the balance is transmitted to the outside through the wiring means 12, the wire 8 and the lead pin 7, and the acceleration can be measured by processing the electric signal outside.

[0007]

Since the conventional acceleration detecting device is constructed as described above, the thin portion 2 of the acceleration detecting beam 1 may be broken when a large impact is applied,
In particular, when the portion where the wiring means 12 of the gauge resistance exists in the thin portion 2 is broken, the bridge circuit is broken and the break can be detected, but the area t where the wiring means 12 is not present.
In the part (2), the bending of the acceleration detection beam 1 cannot be detected, and as a result, there is a problem that the acceleration cannot be detected with high accuracy.

The invention of claim 1 has been made to solve the above problems, and an object thereof is to provide an acceleration detecting device capable of detecting a break in any portion of the thin portion of the acceleration detecting beam. And

It is an object of the present invention to obtain an acceleration detecting device capable of detecting a break in a thin portion by detecting a voltage across a high resistance connected between the thin portion break detecting wiring ends. And

Further, the invention according to claim 3 provides an acceleration detecting device capable of detecting the breakage of the thin portion by detecting the voltage across the diode connected between the ends of the thin portion breakage detecting wiring. To aim.

[0011]

According to another aspect of the present invention, there is provided an acceleration detecting device, wherein an acceleration detecting beam crosses the thin portion from the pedestal side to the vicinity of the weight and then returns to the pedestal side. Such a thin portion breakage detecting wiring means is provided.

The acceleration detecting device according to the invention of claim 2 is
On the acceleration detection beam, the wiring means for detecting the thin portion breakage that crosses the thin portion from the pedestal side to reach the vicinity of the weight and returns to the pedestal side again, and in the middle of the wiring means for the thin portion breakage detection And a low resistance for detecting breakage of the thin portion, and a high resistance for detecting breakage of the thin portion is connected to both ends of the wiring means for detecting breakage of the thin portion.

The acceleration detecting device according to the invention of claim 3 is
On the acceleration detection beam, the wiring means for detecting the thin portion breakage that crosses the thin portion from the pedestal side to reach the vicinity of the weight and returns to the pedestal side again, and in the middle of the wiring means for the thin portion breakage detection It is provided with a low resistance for thin-wall portion breakage detection connected, and a thin-walled portion breakage detection diode is reversely connected to both ends of the thin-wall portion breakage detection wiring means.

[0014]

In the acceleration detecting device according to the first aspect of the present invention, since the thin portion breakage detecting wiring means is provided over the entire width of the thin portion, disconnection detection can be performed regardless of which thin portion is broken. Therefore, the acceleration detection value can be detected with high accuracy together with the determination of whether the acceleration value is normal or not.

In the acceleration detecting device according to the second aspect of the present invention, the bending of the thin portion is detected by detecting the change of the high resistance terminal voltage due to the change of the current flowing in the thin portion breakage detection wiring. Enable accuracy detection.

In the acceleration detecting device according to the third aspect of the invention, the change in the voltage between the terminals of the diode due to the change in the current flowing through the thin portion breakage detection wiring is detected, thereby making it possible to easily and inexpensively break the thin portion. To enable highly accurate detection.

[0017]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 13 is a wiring means 1 of a bridge circuit.
Wiring means for detecting thin portion breakage provided separately from 2, which crosses the thin portion 2 from the pedestal 3 side of the acceleration detection beam 1,
As shown in FIG. 2, after reaching the vicinity of the weight 4, it is wired so as to return to the pedestal 3 side.

Further, 14 is a wiring means 1 for detecting a thin portion breakage.
Both ends of 3 are two lead pins provided so as to be electrically connected to the outside of the apparatus, and 15 is a wire for electrically connecting the lead pin 14 and the thin portion breakage detecting wiring means 13. In addition, the same components as those shown in FIG. 6 are denoted by the same reference numerals, and duplicate description thereof will be omitted.

Next, the operation will be described. First, when acceleration is applied to an acceleration detection device mounted on a vehicle,
Upon receiving this acceleration, the acceleration detection beam 1 bends. Therefore, the stress due to this bending concentrates on the thin portion 2, and the piezoresistive effect of the gauge resistance causes the resistance values of the gauge resistances forming the bridge circuit to be out of balance. Therefore, an electric signal corresponding to the change in the balance is transmitted to the outside through the wiring means 12, the wire 8 and the lead pin 7, and the acceleration can be measured by processing the electric signal outside.

On the other hand, when a large impact is applied to the acceleration detecting device, it may be broken at the thin portion 2 of the acceleration detecting beam 1. However, the thin portion breakage detecting wiring means 13 includes the area t of the thin portion 2. Since it traverses the entire width, the thin-wall portion breakage detecting wiring means 13 may be broken at any portion.
Breaks. Therefore, the breakage of the acceleration detection beam 1 can be detected by confirming the electrical continuity of the two lead pins 14.

Example 2. In the above-mentioned embodiment, the breakage is detected by confirming the continuity of the two lead pins 14. However, as shown in FIG. 3, a high resistance 16 is provided between the two lead pins 14, and the thin portion breaks. Wiring means for detection 1
3 is provided with a low resistance 17 in an appropriate row, and a voltage is applied to the two lead pins 14 from the DC power source 20, so that the disconnection can be detected.

That is, if the thin portion 2 is not broken,
Since a large current Ia flows through the low resistance 17, the high resistance 16
Is small (Ib≈0), and the voltage across the high resistance 16 is low. However, when the thin portion 2 is broken and the low resistance 17 is disconnected from the circuit together with a part of the thin portion breakage detection wiring means 13, the voltage across the high resistance 16 increases. Therefore, by detecting the increased voltage, the breakage of the thin portion 2 can be detected.

Example 3. Further, instead of the high resistance 16 shown in FIG. 3, a diode 18 as shown in FIG. 4 may be used which prevents current (forward direction) from flowing in the direction of current (Ib) (reverse connection). Of course, also in this case, the voltage change for detecting the breakage of the thin portion can be extracted from both ends of the diode 18 with a simple and low-cost configuration, whereby the acceleration can be measured with high accuracy.

[0024]

As described above, according to the first aspect of the invention, the acceleration detecting beam crosses the thin portion from the pedestal side to reach the vicinity of the weight and returns to the pedestal side again. Since the thin portion breakage detecting wiring means is provided, when the thin portion of the acceleration detection beam is broken at any part due to a large impact or the like, this can be reliably detected, and in this state It is possible to prevent the acceleration measurement from being continued, and therefore, by replacing or repairing a new acceleration detection beam, it is possible to obtain an accurate acceleration detection.

According to the second aspect of the present invention, wiring means for detecting a thin portion breakage is provided on the acceleration detecting beam so as to reach the vicinity of the weight by crossing the thin portion from the pedestal side and returning to the pedestal side again. And a low resistance for thin-wall break detection connected in the middle of the thin-wall break detection wiring means, and a high resistance for thin-wall break detection connected to both ends of the thin-wall break detection wiring means. Since it is configured as described above, there is an effect that by detecting the voltage across the high resistance, it is possible to reliably and easily detect the breakage of the thin portion.

According to the third aspect of the present invention, the thin portion breakage detecting wiring is formed on the acceleration detecting beam so as to cross the thin portion from the pedestal side, reach the vicinity of the weight, and return to the pedestal side again. Means and a low resistance for detecting thin-wall breakage connected in the middle of the thin-wall break detection wiring means, and a diode for thin-wall break detection in opposite directions at both ends of the thin-wall break detection wiring means. Since it is configured to be connected, there is an effect that by detecting the voltage across the diode, the breakage of the thin portion can be detected reliably, easily, and at low cost.

[Brief description of drawings]

FIG. 1 is a plan view showing a main part of an acceleration detecting device according to an embodiment of the invention of claim 1. FIG.

FIG. 2 is a front view showing a partially cutaway main part of the acceleration detecting device in FIG.

FIG. 3 is a circuit diagram showing an acceleration detecting device according to an embodiment of the present invention.

FIG. 4 is a circuit diagram showing an acceleration detecting device according to an embodiment of the invention of claim 3;

FIG. 5 is a vertical cross-sectional view showing a conventional acceleration detection device.

FIG. 6 is an enlarged plan view showing a part of a conventional acceleration detection device.

7 is a front view showing a partially cutaway view of the acceleration detecting device in FIG.

[Explanation of symbols]

 1 Acceleration detection beam 2 Thin part 3 Pedestal 4 Weight 9 Oil 13 Wiring means for detecting breakage of thin part 16 High resistance 17 Low resistance 18 Diode A Acceleration detection part P Piezoelectric element C Case

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[Procedure amendment]

[Submission date] February 22, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 3

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

According to a second aspect of the present invention, there is provided a thin portion breakage detecting wiring .
An object of the present invention is to obtain an acceleration detecting device capable of detecting a break in a thin portion by detecting a flowing circuit current .

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

Further, the invention of claim 3 is also the same as in claim 2, wherein the acceleration detecting device capable of detecting the breakage of the thin portion by detecting the circuit current flowing in the thin part breakage detection wiring. Aim to get.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0015

[Correction method] Change

[Correction content]

The acceleration detecting device in the invention of claim 2 is the folding of the thin portion, by detecting the current change that flows through the thin portion folded sensing wire, to the breaking of the possible precision detection.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction content]

The acceleration detection device in the invention of claim 3, by detecting the current change that flows through the detection wire folded thin portion like the second aspect, high breakage of the thin portion at a simple and inexpensive circuit Enable accuracy detection.

[Procedure correction 6]

[Document name to be amended] Statement

[Name of item to be corrected] 0022

[Correction method] Change

[Correction content]

That is, if the thin portion 2 is not broken,
Since a large current Ia flows through the low resistance 17, the high resistance 16
Is small (Ib≈0 circuit current≈Ia). However, when the thin portion 2 is broken and the low resistance 17 is disconnected from the circuit together with a part of the thin portion break detection wiring means 13, the circuit current = Ib≈0 , and the thin portion 2 is broken due to the current value change. Can be detected.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Name of item to be corrected] 0023

[Correction method] Change

[Correction content]

Example 3. Further, instead of the high resistance 16 shown in FIG. 3, a diode 18 as shown in FIG. 4 may be used which prevents current (forward direction) from flowing in the direction of current (Ib) (reverse connection). well, also in this case, a simple and low-cost configuration, times in order to detect the bending of the thin portion
Acceleration can be measured with high accuracy by comparing changes in the path current .

[Procedure Amendment 8]

[Document name to be amended] Statement

[Name of item to be corrected] 0024

[Correction method] Change

[Correction content]

[0024]

As described above, according to the first aspect of the invention, the acceleration detecting beam crosses the thin portion from the pedestal side to reach the vicinity of the weight and returns to the pedestal side again. Since the thin portion breakage detecting wiring means is provided, when the thin portion of the acceleration detection beam is broken at any part due to a large impact or the like, this can be reliably detected, and in this state It is possible to prevent the acceleration measurement from being continued, and therefore, by replacing the new acceleration detection device, it is possible to obtain a device that can always accurately detect the acceleration.

[Procedure Amendment 9]

[Document name to be amended] Statement

[Name of item to be corrected] 0025

[Correction method] Change

[Correction content]

According to the second aspect of the present invention, wiring means for detecting a thin portion breakage is provided on the acceleration detecting beam so as to cross the thin portion from the pedestal side, reach the vicinity of the weight, and return to the pedestal side again. A low resistance for thin-wall break detection connected in the middle of the thin-wall break detection wiring means, and a high resistance for thin-wall break detection connected to both ends of the thin-wall break detection wiring means. Since it is configured as described above, there is an effect that by detecting the change in the circuit current, it is possible to reliably and easily detect the breakage of the thin portion.

[Procedure Amendment 10]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Change

[Correction content]

According to the third aspect of the present invention, the thin portion breakage detecting wiring is formed on the acceleration detecting beam so as to cross the thin portion from the pedestal side, reach the vicinity of the weight, and return to the pedestal side again. Means and a low resistance for detecting thin-wall breakage connected in the middle of the thin-wall break detection wiring means, and a diode for thin-wall break detection in opposite directions at both ends of the thin-wall break detection wiring means. Since it was configured to connect, the circuit
By detecting the change in current, it is possible to
There is an effect that what can be detected reliably, easily and at low cost is obtained.

Claims (3)

[Claims] 1. An acceleration detection beam having one end supported by a pedestal and a weight provided at the other end, a thin-walled portion formed on the acceleration detection beam for concentrating stress generated by acceleration. An acceleration detecting section including a piezoelectric element connected on the thin portion and converting the change of the stress into an electric signal is bridged, and the acceleration detecting beam having the acceleration detecting section and the thin portion is enclosed in viscous oil. In the semiconductor acceleration detecting device including a case, a wire for detecting a thin-walled portion that crosses the thin-walled portion from the pedestal side, reaches the vicinity of the weight, and returns to the pedestal side again on the acceleration detection beam. An acceleration detecting device comprising means. 2. An acceleration detection beam having one end supported by a pedestal and a weight provided at the other end, a thin-walled portion formed on the acceleration detection beam for concentrating stress generated by acceleration. An acceleration detecting section including a piezoelectric element connected on the thin portion and converting the change of the stress into an electric signal is bridged, and the acceleration detecting beam having the acceleration detecting section and the thin portion is enclosed in viscous oil. In the semiconductor acceleration detecting device including a case, a wire for detecting a thin-walled portion that crosses the thin-walled portion from the pedestal side, reaches the vicinity of the weight, and returns to the pedestal side again on the acceleration detection beam. Means, a low resistance for thin-wall break detection connected in the middle of the thin-wall break detection wiring means, and a high resistance for thin-wall break detection connected to both ends of the thin-wall break detection wiring means With And an acceleration detecting device. 3. An acceleration detection beam having one end supported by a pedestal and a weight provided at the other end, a thin portion formed on the acceleration detection beam for concentrating stress generated by acceleration. An acceleration detecting section including a piezoelectric element connected on the thin portion and converting the change of the stress into an electric signal is bridged, and the acceleration detecting beam having the acceleration detecting section and the thin portion is enclosed in viscous oil. In the semiconductor acceleration detecting device including a case, a wire for detecting a thin-walled portion that crosses the thin-walled portion from the pedestal side, reaches the vicinity of the weight, and returns to the pedestal side again on the acceleration detection beam. Means, a low resistance for thin-wall portion breakage detection connected in the middle of the thin-wall breakage detection wiring means, and a thin-wall breakage detection diode reversely connected to both ends of the thin-wall break detection wiring means. When An acceleration detecting device comprising: