JPH085656A - Acceleration converter - Google Patents

Abstract

PURPOSE:To obtain a rigid and small-sized acceleration converter having high natural frequency and strain output sensitivity and excellent in long term stability, hysteresis characteristics and creep characteristic in which the assembling work and repairing work are facilitated. CONSTITUTION:The acceleration converter comprises a cantilever beam 3 comprising a driven part 3a, a flexible part 3d, and a weight part 3e, a pair of reinforcing membranes 4, 5, insulating films 6, 7, four strain gauges SG1-SG4, and a casing 1 (with cover 1a). When the driven part 3a is subjected to vibration or impact from an object 2, the weight part 3e is pivoted about the flexible part 3d relatively to driven part 3a by the inertial force. Consequently, tensile or compressive strain is generated in the reinforcing membranes 4, 5. The strain is detected by means of the strain gauges SG1-SG4 fixed to the reinforcing membranes 4, 5 through the insulating films 6, 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acceleration converter,
More specifically, a weight is supported via a flexible part on a driven part that moves integrally with the object to be measured, and when the driven part receives an acceleration, the weight is moved relative to the driven part. The present invention relates to an acceleration converter of a system in which a strain caused by relative displacement is converted into an electric signal by a strain gauge and the acceleration is detected.

[0002]

2. Description of the Related Art Acceleration converters are widely used for measuring impact strength of a structure or for analyzing an acceleration waveform of vibration generated in a structure. As the conventional acceleration converter used in this way, for example, when the driven portion receives an acceleration, the weight is displaced relative to the driven portion to generate a strain, that is, to detect the acceleration. An electric resistance type strain gauge (in the form of a foil or a wire) whose resistance changes with strain is attached to the surface of the strain generating body (Japanese Patent Publication No.
No. 52,899) and a type in which a diffusion type semiconductor gauge is attached (JP-A-59-158566).

[0003]

In such an acceleration converter, it is required that the output signal is sufficiently large with respect to noise even with a small acceleration and that the response is good. As one measure to improve the sensitivity of the acceleration converter, there is a method of increasing the weight and increasing the amount of beam displacement. However, this method has a drawback that the natural frequency is low and the response frequency range is narrow.

If the spring constant of the strain-flexing portion is reduced,
While the flexure of the strain-flexing part is increased and the strain output is increased, the natural frequency is decreased and the response frequency range is narrowed as in the above. In addition, in order to develop an ultra-compact acceleration transducer, it is necessary to minimize the strain gauge, but the current metal foil strain gauge method has certain limits, is small, and has a high resistance value (specific resistance). The production of strain gauges in) is currently difficult.

On the other hand, in addition to the electric resistance type strain gauge, there is one using the above-mentioned diffusion type semiconductor. In this, the strain generating body is formed of a crystalline silicon substrate and the diffusion type semiconductor is formed on this substrate. By doing so, the strain receiving element is configured. In the case of this diffusion type semiconductor gage, although a gage factor which is significantly higher than that of the electric resistance type strain gage described above can be obtained, it has a large temperature coefficient of resistance and therefore requires a complicated temperature compensation circuit. Since the elastic limit is low and brittle, it is necessary to pay close attention during assembly, and brittle fracture tends to occur due to mechanical overload.

The present applicant has previously proposed the following acceleration converter (hereinafter referred to as the "prior invention") as Japanese Patent Application No. 5-341145 in order to overcome the drawbacks of the prior art. .

That is, according to the invention of the prior application, the weight is supported by the driven portion which integrally moves with the object to be measured through the flexible portion, and when the driven portion receives an acceleration, the weight is moved. In an acceleration converter of the type that detects the acceleration by converting the strain when displaced relative to the driven part into an electric signal with a strain gauge, the side peripheral surface facing the middle part of the beam having a rectangular cross section. By forming slits with a certain depth from both sides of the, the driven part with high rigidity on the base end side, the weight part with high rigidity on the tip end side, and the flexible flexible part in the middle part A cantilever provided with a portion and a pair of slits formed in an intermediate portion of the cantilever so as to straddle each of the driven portion and the weight portion. Flexible pair of flexure plates and this pair At least one pair of strain gauges attached to the slit-side surface layer of the flexure plate so as to detect strain, and the cantilever is deformed by the acceleration acting on the weight portion. Can be detected by the pair of strain gauges by adding a tensile / compressive strain acting on the strain-flexing plate by the bending strain and a bending strain generated by the strain-generating plate itself being deformed by the acceleration acting on the strain-flexing plate. It is configured as follows.

In the acceleration converter according to the invention of the prior application constructed as described above, the flexible portion formed in the middle portion of the cantilever beam functions as the hinge of the beam, and the measured object is driven by the driven portion. When an acceleration is applied via the, bending strain is concentratedly generated in the flexible portion. However, the pair of flexure plates, which are joined to both side surfaces of the driven portion and the weight portion so as to straddle a pair of opposing slits formed to provide the flexible portion, prevent bending of the beam. , One strain plate receives a tensile force, the other strain plate receives a compressive force,
It produces tensile or compressive strain, respectively.

On the other hand, not only these tensile and compressive strains are generated in the strain-flexing plate, but also bending strains are generated by the strain-generating plate itself being deformed into a curved shape by the acceleration acting on the strain-generating plate. To do. Therefore, in the strain gauge attached to the inside (or the facing surface) of the pair of flexure plates, in other words, the surface layer of the flexure plate on the slit side, the increase / decrease in the gap between the driven part and the weight is caused. Not only the tensile strain or compressive strain, but also the bending strain that the flexure plate itself receives an acceleration and bends will be detected,
The strain output can be greatly increased.

However, in the invention of the prior application which is constructed and operates as described above, a strain gauge is adhered to the surface of the flexure plate on the slit (inner surface) side in order to obtain sufficient detection sensitivity. Since the strain gauge must be accurately placed inside the plate at a predetermined position in the narrow area of the slit, the grid portion of the strain gauge cannot be directly checked, resulting in misalignment with the slit or disconnection of the grid. However, there is a difficulty that it is not easy to find such defects.

Further, in the above-mentioned embodiment of the invention of the prior application, as described later, it was not possible to obtain sufficiently satisfactory hysteresis and creep characteristics. The present invention has been made in view of the above circumstances, and its object is to:
It is relatively small, can increase strain output while increasing natural frequency, is easy to assemble, can be used stably for a long time, and the position and state of the strain gauge grid can be directly applied from the outside. Another object of the present invention is to provide an acceleration transducer that is observable and that can improve hysteresis and creep characteristics.

[0012]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides that a weight is supported via a flexible part on a driven part that moves integrally with an object to be measured. In the acceleration converter of the method of converting the strain when the weight is displaced relative to the driven part when the driven part receives an acceleration into an electric signal by a strain gauge to detect the acceleration, the middle part of the beam In addition, by forming slits with a constant depth from both sides of the opposite side peripheral surfaces, a driven part with large rigidity is formed on the base end side, a heavy weight part is formed on the distal end side, and a heavy weight part is formed on the middle part. The both sides of the driven portion and the weight portion so as to straddle a cantilever beam having flexible portions and a pair of slits formed in an intermediate portion of the cantilever beam. A pair of complementary thin films each bonded to a surface A film, a pair of thin-walled insulating films attached to the anti-slit side surfaces of the pair of reinforcing films, and a strain gauge attached to the anti-slit side surfaces of the pair of insulating films, It is configured such that the pair of strain gauges can detect the tensile / compressive strain acting on the reinforcing film due to the deformation of the cantilever beam due to the acceleration acting on the weight portion. It is what

Further, in order to achieve the above object, according to the present invention, a weight is supported via a flexible portion on a driven portion that moves integrally with an object to be measured, and the driven portion accelerates. In the acceleration converter of the type in which the strain when the weight is relatively displaced with respect to the driven part when receiving the force is converted into an electric signal by a strain gauge and the acceleration is detected, it is opposed to the middle part of the beam. By forming slits with a certain depth from both sides of the side peripheral surface, a driven part with large rigidity is formed on the base end side, a weight part with large rigidity is formed on the tip end side, and flexibility is formed in the middle part. A flexible beam having a flexible portion and a pair of slits formed in an intermediate portion of the flexible beam are respectively joined to the driven portion and the peripheral surfaces of the weight portion so as to extend across the pair of slits. Of a thin film having flexible and insulating properties A strong and film, and a strain gauge which is affixed formed in the counter-slit-side surface of the reinforcing film of this pair, and
The tensile / compressive strain acting on the reinforcing film by the deformation of the cantilever beam due to the acceleration acting on the weight portion,
It is characterized in that it can be detected by the pair of strain gauges.

More specifically, the present invention is characterized in that the reinforcing film has a Young's modulus of 7,000 kgf / mm ² or more and a film thickness of 1 to 10 μm.
Further, the present invention is more specifically, the film thickness of the insulating film is
It is characterized in that it is 1 to 10 μm.

[0015]

In the acceleration converter configured as described above, the flexible portion formed in the intermediate portion of the cantilever beam functions as the hinge of the beam, and receives acceleration from the measured object via the driven portion. At this time, bending strain is intensively generated in the flexible portion. But,
A pair of reinforcing films respectively joined to both side peripheral surfaces of the cantilever so as to straddle a pair of opposing slits formed to provide the flexible portion function to prevent bending of the beam, One of the reinforcing films receives a tensile force and the other reinforcing film receives a compressive force to generate tensile strain or compressive strain, respectively.

Therefore, the strain gauges attached to the outer surfaces of the pair of reinforcing membranes, in other words, the surface layers of the reinforcing membranes on the side opposite to the slits, are stretched due to the increase or decrease in the gap between the driven portion and the weight. Strain or compressive strain is detected, and a large strain output can be obtained.

[0017]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. FIG. 1 is a side sectional view schematically showing the overall configuration of an acceleration converter according to the present invention, and FIG. 2 is a sectional view taken along line XX of FIG. Further, FIG. 3 is a circuit diagram showing a configuration of a Wheatstone bridge circuit assembled with a strain gauge attached to the reinforcing film of the embodiment shown in FIGS. 1 and 2.

In FIG. 1, a casing 1 of the acceleration converter is formed in a rectangular columnar cylindrical body, and a mounting flange portion 1 is provided on one surface side (lower end surface side in FIG. 1) of the casing 1.
b and 1c are formed, and a U for mounting screw is formed in the middle part.
The U-shaped grooves 1d and 1e are formed, and the U-shaped grooves 1d and 1e are formed.
The casing 1 is attached to the measured object 2 by a mounting screw (not shown) inserted through e.

On one side wall (the right side wall in FIG. 1) of the casing 1, the base end of the cantilever 3, that is, the base end of the driven portion 3a, is press-fitted, screwed, though not shown.
It is firmly fixed by welding and other fixing means,
The other side wall (the left side wall in FIG. 1) is open, and the open end is closed by the lid 1a.

According to the method of forming the cantilever 3, the slits 3b, 3 having a constant depth from the opposing side peripheral surfaces (upper surface and lower surface in FIG. 1) are formed in the middle portion of the beam having a rectangular cross section.
By forming c, a flexible portion 3d having a predetermined thickness h is provided at the center of the beam in the thickness direction, and a weight portion 3e is provided on the tip side (free end side) of the flexible portion 3d. There is.

That is, only the flexible portion 3d is thin and flexible, and when the driven portion 3a is subjected to acceleration, it has a hinge function, while the driven portion 3a and the weight portion 3e are provided. Means that it is sufficiently thicker than the flexible portion 3d and has a large rigidity so that it does not substantially bend even when subjected to acceleration. Particularly, the weight portion 3e has a mass of an acceleration converter. It is a factor that determines the natural frequency of and the factor that determines the acceleration detection sensitivity.

The driven portion 3 straddles (bridges) a pair of slits 3b, 3c formed in the middle portion of the cantilever 3.
The thin reinforcing films 4 and 5 made of a spring material, for example, beryllium copper, phosphor bronze, etc. are firmly bonded to the both side surfaces of the a and the weight portion 3e by bonding, welding, vapor deposition, or other means. There is. That is, the reinforcing films 4 and 5 are set so that their plate surfaces are parallel to the plate surface of the flexible portion 3d when no load is applied (when acceleration is not applied).

The pair of reinforcing films 4 and 5 have a film thickness of 6 μm and Young's modulus of 16,000 kgf / mm ² , and the film thickness is in the range of 1 to 10 μm. Should be 7,000 kgf / mm ² or more. A surface of the pair of reinforcing films 4 and 5 opposite to the slits 3b and 3c (hereinafter referred to as "anti-slit side surface"), that is, reinforcements arranged to face each other with the flexible portion 3d interposed therebetween. The outer surface (upper surface side and lower surface side) of each of the membranes 4 and 5 has a thickness of 1 to 10 μm, more preferably 5 to 10 μm.
Insulating films 6 and 7 having a thickness of m are attached by an adhesive.

On the surfaces of the insulating films 6 and 7, a thin foil material is used as a raw material, and strain gauges (foil gauges) SG1 and SG2 formed by patterning a grid portion and a gauge tab portion by, for example, a photo etching method, and Strain gauges (foil gauges) SG3 and SG4 which do not appear are attached by an adhesive. This strain gauge S
G1 and SG2 and SG3 and SG4, as shown in the schematic shape in FIG. 2, have two sensing axes oriented in parallel with the longitudinal direction of the cantilever 3 in parallel with each other. Sensitive portions are attached to the outer surfaces of the insulating layers 6 and 7 at the portions corresponding to the slits 3b and 3c.

One end of a lead wire 8 is connected to each of the gauge tabs of these strain gauges SG1 to SG4 by soldering, and the other end side of the lead wire 8 is a cantilever beam 3.
Through the wiring groove 3f formed on the side surface of the casing 1
The other end of each of the lead wires 8 is led to the outside of, and, for example, although not shown, is guided to a measuring device that measures acceleration through a terminal box, but inside or near the acceleration converter, The strain gauges SG1 and SG2 attached to the upper surface of the reinforcing film 4 are arranged on opposite sides as shown in FIG. 3, and the strain gauges SG3 and SG4 attached to the lower surface of the reinforcing film 5 are The Wheatstone bridge circuit 9 is configured by being connected to the opposite sides adjacent to each other.

Although not shown in the drawing, an external resistance for adjusting the initial unbalance of the Wheatstone bridge circuit 9 and temperature compensation is added to the bridge circuit.

Next, the operation of the acceleration converter configured as described above will be described. The casing 1 of the acceleration converter is screwed to the object to be measured 2 and is firmly fixed by other means. In this state, the acceleration G is applied to the driven portion 3a via the bottom portion and the right portion of the casing 1 due to the vibration, impact, etc. of the measured object 2, and the inertial force F acts on the cantilever 3 as shown in FIG. Then, the weight portion 3e is relatively displaced with respect to the casing 1 to bend the flexible portion 3d, and at the same time, the pair of upper and lower reinforcing films 4 and 5 are formed.
Bend.

At this time, the upper reinforcing film 4 is provided with the slit 3b.
The open end (upper end) is deformed so as to open, so that it is stretched by receiving a tensile force, resulting in tensile strain. Also,
The lower reinforcing film 5 is deformed so that the opening end of the slit 3c is closed, so that the lower reinforcing film 5 receives a compressive force and is compressed to generate a compressive strain.

Therefore, the two strain gauges SG1 and S attached to the surface layer portion of the reinforcing film 4 on the side opposite to the slit 3b.
G2 detects the tensile strain due to the spread of the open end (upper end) of the slit 3b by the acceleration acting on the weight 3e, and the cantilever 3 greatly increases the resistance value.

On the other hand, the two strain gauges SG3 and SG attached to the surface layer portion of the reinforcing film 5 on the side opposite to the slit 3c.
In No. 4, the cantilever 3 is deformed as described above by the acceleration acting on the weight 3e and the compressive strain due to the narrowing of the opening end (lower end) of the slit 3c is detected, and the resistance value thereof is greatly reduced. .

The above explanation of the operation is based on the casing 1
Although the acceleration is applied in the upward direction, when the acceleration is applied in the downward direction, the weight portion 3e is relatively displaced upward by the inertial force using the flexible portion 3d as a hinge. Therefore, the resistance values of the strain gauges SG1, SG2 attached to the surface layer surface on the side opposite to the slit 3b of the reinforcing film 4 are greatly reduced contrary to the above description, and the resistance value of the strain gauge SG1 on the opposite side of the slit 3c of the reinforcing film 5 is increased. Strain gauge S attached to the surface
It is easily understood that the resistance values of G3 and SG4 greatly increase.

Thus, according to the above-described embodiment, the first
In addition to the fact that a larger strain output is obtained as compared with the case where a strain gauge is attached to the surface of the flexible portion 3d,
The thin reinforcing films 4 and 5 having flexibility are provided with slits 3b and 3
Since the bridge is configured so as to straddle c, the cantilever 3
Therefore, it is possible to provide an acceleration transducer having a relatively small size, robustness, high natural frequency, and high sensitivity.

Secondly, since the strain gauges SG1, SG2 and SG3, SG4 are attached to the anti-slit side surfaces (the upper surface and the lower surface in FIG. 1) of the reinforcing films 4 and 5, the respective strain gauges are arranged. Acceleration conversion capable of easily aligning the grid portions of SG1 to SG4 with the slits 3b and 3c and easily confirming a defect such as a broken wire of the grid from the outside, and thus improving the reliability of measurement. Can be provided.

Thirdly, the thickness of the reinforcing films 4 and 5 is set to 1 to 10 μm.
In the range of m, the thickness of the insulating films 6 and 7 is 1 to 10 μm.
Since the value is within the range, the hysteresis characteristic and the creep characteristic are improved as shown in FIGS. That is, in FIG. 5, the horizontal axis represents acceleration and the vertical axis represents the output of the acceleration converter, and the hysteresis characteristics of the above-described embodiment of the present invention and the acceleration converter of the prior invention are shown in comparison. is there.

From FIG. 5, compared with the prior invention,
It can be seen that the acceleration converter of the present invention has much smaller hysteresis and is greatly improved. In addition, in FIG.
The horizontal axis represents time (minutes) and the vertical axis represents creep output με (1 × 1
0 ^-6 ) are respectively taken to compare the above-mentioned embodiment according to the present invention with the acceleration converter according to the invention of the prior application.
As can be seen from the above, the creep of the present invention is improved to less than half that of the prior invention.

Incidentally, when the thickness of the reinforcing film is 1 μm or less, the reinforcing effect is significantly reduced, and when it exceeds 10 μm, the rigidity is increased and the output is lowered and the hysteresis characteristics and the creep characteristics are deteriorated. . Further, it has been clarified that if the thickness of the insulating film is less than 1 μm, the insulation resistance becomes too small to be practical, and if it exceeds 10 μm, the creep characteristics and the hysteresis characteristics are deteriorated.

Fourthly, since the strain gauges SG1 to SG4 are attached via the reinforcing films 4 and 5, the weight portion 3 is formed.
By adjusting the weight of e, it is possible to provide an acceleration transducer that can obtain a high resonance frequency (natural frequency) even with the same sensitivity.

Fifth, since high strain sensitivity can be obtained without using a semiconductor gauge as a strain gauge, temperature compensation is easier than that of a semiconductor gauge, and it is not fragile like a semiconductor gauge so that it may crack. , Peeling is difficult, and as a result, the assembly work is facilitated and the initial set value is not easily deviated, and the foil or line strain gauge or the strain gauge formed by vapor deposition or the like is used. It is possible to provide an acceleration converter that can achieve the effect of 1.

The present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the scope of the invention. For example, in the above-described embodiment, the reinforcing films 4 and 5 are adhered to the insulating films 6 and 7 with an adhesive, but the insulating films 6 and 7 may be directly subjected to chemical vapor deposition such as CVD or physical vapor deposition such as sputtering. The case of attaching by vapor deposition means is also included in the gist of the present invention.

The strain gauges SG1 to SG4 are also
The insulating film is not limited to being bonded to the edge films 6 and 7 with an adhesive.
Even when the above-mentioned vapor deposition means is used to attach to 6, 6 and 7,
It is included in the gist of the invention. Further, the present invention is shown in FIG.
As shown as a modified example of
On the back surface of each of the gauges SG1 to SG4, for example, the CVD method
Due to SiO ₂Insulation thin film (3μm, Young's modulus of about 7
300kgf / mm²) To form a reinforcing film and an insulating film.
So that the reinforcing membranes 4'and 5'having both functions of
You may

Further, although the weight portion 3e is shown as an example integrated with the cantilever beam 3, the weight portion 3e is formed as a separate body and is integrated by soldering, brazing, bonding, screwing, or other means. It may be configured to change. In addition, in the casing 1,
Various compensation resistors may be housed, or circuit elements such as an amplifier may be housed.

The mounting flanges 1b and 1c provided on the casing 1 are not limited to being provided on the bottom portion in FIG. 1, but may be provided on the side portion or the upper portion. Further, the attachment structure to the object to be measured is not limited to the illustrated example, and it goes without saying that adhesion, welding, screwing or other means can be used.

Further, the number of strain gauges is not limited to two per one reinforcing membrane, and one or three or more strain gauges may be attached, or two strain gauges may be superposed and attached. May be. The reinforcing films 4 and 5 may be formed integrally with the cantilever 3 instead of being formed separately.

[0044]

As is apparent from the above detailed description, according to the present invention, a relatively small size, high strain sensitivity can be obtained without lowering the natural frequency, and strong toughness against shock and vibration can be obtained. Having, easy assembling work and temperature compensation, it is possible to maintain stability for a long period of time, and it is possible to directly observe defects such as the alignment state of the grid of the strain gauge, disconnection of the grid, etc. from the outside, In addition, it is possible to provide an acceleration converter having excellent hysteresis characteristics and creep characteristics.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a configuration of an embodiment of an acceleration converter according to the present invention.

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

FIG. 3 is applied to the acceleration converter according to the present invention 4
It is a circuit diagram which shows the structure of the Wheatstone bridge circuit assembled by the one strain gauge.

FIG. 4 is a side sectional view showing the configuration of a modified embodiment of the acceleration converter according to the present invention.

FIG. 5 is a hysteresis characteristic diagram showing the hysteresis characteristics of the acceleration converter according to the present invention and the prior invention.

FIG. 6 is a creep characteristic diagram showing the creep characteristics of the acceleration converter according to the present invention and the invention of the prior application.

[Explanation of symbols]

 1 casing 1a lid 1b, 1c mounting flange 1d, 1e mounting groove U groove 2 object to be measured 3 cantilever 3a driven part 3b, 3c slit 3d flexible part 3e weight part 3f wiring groove 4, 5, 4 ', 5'Reinforcement film 6,7 Insulation film 8 Lead wire 9 Wheatstone bridge circuit SG1 to SG4 Strain gauge

Claims (5)

[Claims] 1. A weight is supported by a driven part that moves integrally with an object to be measured through a flexible part, and when the driven part receives an acceleration, the weight is moved relative to the driven part. In the acceleration transducer of the method that detects the acceleration by converting the strain at the time of relative displacement into an electrical signal with a strain gauge, slits with a certain depth from both sides of the opposing side peripheral surface are provided in the middle part of the beam. By forming it, a cantilever having a driven part with high rigidity on the base end side, a weight part with high rigidity on the tip end side, and a flexible part with flexibility on the middle part. And a pair of flexible thin films which are joined to the both side peripheral surfaces of the driven portion and the weight portion so as to straddle a pair of slits formed in the middle portion of the cantilever. Each of the reinforcing film and the surface of the pair of reinforcing films on the side opposite to the slit side. A pair of thin-walled insulating films attached to each other, and a strain gauge attached to the surface of the pair of insulating films on the side opposite to the slit, and the cantilever beam with an acceleration acting on the weight portion. An acceleration transducer characterized in that tensile strain / compression strain acting on the reinforcing film due to deformation of the strain gauge can be detected by the pair of strain gauges. 2. A weight is supported by a driven part that moves integrally with an object to be measured via a flexible part, and when the driven part receives an acceleration, the weight is moved relative to the driven part. In the acceleration transducer of the method that detects the acceleration by converting the strain at the time of relative displacement into an electrical signal with a strain gauge, slits with a certain depth from both sides of the opposing side peripheral surface are provided in the middle part of the beam. By forming it, a cantilever having a driven part with high rigidity on the base end side, a weight part with high rigidity on the tip end side, and a flexible part with flexibility on the middle part. And a thin film having flexibility and insulation, which is joined to the both side peripheral surfaces of the driven portion and the weight portion so as to straddle a pair of slits formed in the middle portion of the cantilever. A pair of reinforcing membranes and a side of the pair of reinforcing membranes opposite to the slit side A strain gauge attached to a surface of the strain gauge, and the strain gauge acting on the reinforcing film by the deformation of the cantilever beam due to the acceleration acting on the weight portion. An acceleration converter characterized by being configured so as to be detected by. 3. The Young's modulus of the reinforcing film is 7,000 kg /
The acceleration converter according to claim 1, wherein the acceleration converter is made of a thin film of ² mm ² or more. 4. The acceleration converter according to claim 1, 2 or 3, wherein the thickness of the reinforcing film is 1 to 10 μm. 5. The acceleration transducer according to claim 1, wherein the insulating film provided between the reinforcing film and the strain gauge has a thickness of 1 to 10 μm.