JPH09257827A - Acceleration detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide inexpensively an acceleration detector being excellent in a low frequency characteristic and accuracy in detection and free from the possibility of occurrence of disconnection and destruction of an element. SOLUTION: A printed board 2 functioning also as a reference member is fixed on a base member 1 being a member of which the acceleration is to be detected and a mass body 6 is supported on the board by a leaf spring 5 being an elastic support member so that it is displaceable relatively to the base member 1 in the direction of receiving the acceleration. Opposite to the lower side of the portion of the leaf spring 5 at which the mass body 6 is supported, a photoreflector 7 and the base part of a dome-shaped elastic body 8 covering this and having a reflecting surface 9 formed inside the upper part are fixed on the printed board 2. The mass body 6 and the printed board 2 are displaced relatively when they receive the acceleration in the directions A shown by arrows, and thereby a distance between the reflecting surface 9 and the photoreflector 7 is changed. This change is detected by the photoreflector 7, an output signal thereof is processed by a processing circuit 10 and thereby information on the acceleration is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acceleration detector for detecting acceleration when a reference member (acceleration detection target member) undergoes acceleration / deceleration. The present invention relates to an acceleration detector suitable for controlling sounds generated by electronic musical instruments and automatic musical instruments based on acceleration information.

[0002]

2. Description of the Related Art The acceleration received by a moving object or a stationary object is detected, a warning is issued when the acceleration exceeds a predetermined value, the moving speed or various other parameters are obtained based on the detected acceleration information, and the acceleration is calculated. Various acceleration detectors have been developed to perform parameter control related to.

For example, there is an acceleration detector as shown in FIG. This is the base member 2 which is the member for which acceleration is to be detected.
The base end portion of a leaf spring 22 having a mass body 21 attached to the tip end thereof is fixed to a ridge portion 20a formed on the upper surface by a screw 23, and the mass body 21 is subjected to acceleration by the cantilevered leaf spring 22. It is movably supported in the direction (direction of arrow A). Further, between the screw 23 of the leaf spring 22 and the mass body 21, a strain sensor 24 such as a strain cage element or a piezo element is provided.
Is firmly attached by a method such as pressure heating using an adhesive.

Then, the strain sensor 24 and the base member 2
The processing circuit 26 on the printed circuit board 25, which is mounted in close proximity to 0, is connected by a connection line 27. According to this acceleration sensor, when the base member 20 is subjected to acceleration in the direction of arrow A and is displaced in the same direction, the mass body 21 is displaced with a delay due to inertial force in order to maintain the position at that time. The positional relationship (distance D) in the direction A shown in the figure changes relatively, and the leaf spring 2 is moved according to the magnitude of the acceleration received.
2 bends and deforms as shown by a virtual line.

At this time, the strain generated on the surface of the leaf spring 22 is
Detected by the strain sensor 24, the detection signal is input to the processing circuit 26 on the printed circuit board 25 for processing, and acceleration detection information (signal) is output. The acceleration detection principle of the case where a strain gauge is used as the strain sensor 24 and the case where a piezo element is used will be described in more detail.

<When a strain gauge element is used> The strain gauge element has a property of showing a resistance value according to the dimension at that time. When a strain gauge element is attached to the root of the leaf spring 22,
The resistance value of the strain gauge element when the leaf spring 22 is not deformed as shown by the solid line in FIG. 12 is R1, and the strain gauge element when the leaf spring 22 is deformed by δ at the tip as shown by the phantom line. When the resistance value is R2, (R2-R1) becomes a value proportional to the displacement δ. That is, this difference in resistance value (R2-
R1) can be treated as a value proportional to the magnitude of the acceleration received by the mass body 21.

<When a Piezo Element is Used> The piezo element has a property of generating a voltage according to the speed of dimensional change.
After the dimension changes, no voltage is generated when the dimension remains constant. Therefore, when a piezo element is attached to the base of the leaf spring 22, if the voltage generated by the piezo element is V, it will be a value proportional to the value obtained by differentiating the displacement δ of the leaf spring 22 with time. The voltage V is not generated when a constant acceleration is continuously applied. Therefore, the value obtained by time-integrating the generated voltage V is proportional to the displacement δ and is proportional to the received acceleration.

[0008]

The above-mentioned piezo element is inexpensive in terms of price. However, since the voltage V generated by the piezo element is proportional to the rate of change of the displacement δ as described above, a value proportional to acceleration can be obtained by integrating the voltage V over time. However, in reality, even when the displacement δ is zero, V has a slight DC component. Therefore, if this voltage V is integrated as it is, even if the displacement δ is zero, the integrated value gradually increases with the passage of time, and it is detected as if a large acceleration is being applied.

In order to avoid this, it is necessary to cut the direct current component of the generated voltage V, that is, to filter the low frequency component (through a high pass filter) and perform the integration. However, in that case, the low frequency voltage V generated by the acceleration becomes difficult to be reflected in the integrated value. That is, there is a problem that the low-frequency characteristic deteriorates, and a relatively slow change in acceleration, such as when a person shakes the base member 20 by hand, may not be detected.

On the other hand, since the strain gauge element can directly detect the amount of strain (displacement δ), an output corresponding to the magnitude of the acceleration can be obtained without integrating, so that the low frequency characteristic as when using a piezo element is obtained. There is no factor that deteriorates. But,
There is a problem that the manufacturing process of the strain gauge element requires a high degree of control and is expensive.

Further, in any case, a slight dimensional change of the surface 22a caused by the bending as shown by the phantom line when the acceleration is applied from the steady state shown by the solid line in FIG. 13 of the leaf spring 22 is detected. Therefore, since the detection signal is small, it is necessary to improve the S / N and reduce the drift of the processing circuit in order to stably amplify it, and the processing circuit 26 becomes expensive. Further, in both cases, it is necessary to firmly adhere the element of the strain sensor 24 to the leaf spring 22 by applying pressure and heating by using an adhesive to prevent deterioration due to repeated stress, aging, etc., which is also costly.

Further, in any case, the leaf spring 2
From the strain sensor 24 adhered to 2 to the processing circuit 26 on the printed circuit board 25, it is necessary to provide wiring by the connection line 27, and not only the labor becomes a factor of cost increase,
There is also a problem that the connecting line may be broken due to vibration or acceleration. Furthermore, there is a risk that excessive stress will be applied to the strain sensor 24, which may damage the element.

The present invention has been made in order to solve various problems in such a conventional acceleration detector, and has an excellent low-frequency characteristic, and is free from the risk of disconnection or element destruction. The purpose is to provide a detector at low cost. Here, the “acceleration detection target member” used in the above description and the following description refers to what degree of acceleration is applied when an object subjected to acceleration (or inertial force) receives acceleration (or inertial force). It can be said that it is a reference member (base member) that serves as a reference for detecting whether or not.

[0014]

In order to achieve the above object, an acceleration detector according to the present invention supports a reference member and a mass body, and supports the mass body so as to be displaceable in a direction in which acceleration is applied to the reference member. An elastic support member, and a displacement detection means provided between the reference member and the mass body or the elastic support member, for detecting relative displacement between the reference member and the mass body according to the acceleration received by the reference member, and Acceleration information output means for outputting information indicating the magnitude of acceleration based on the displacement detection signal from the displacement detection means.

Further, a reference member and a mass body, an elastic support member having a base end portion fixed to the reference member, and a distal end portion supporting the mass body so as to be displaceable in a direction in which the reference member receives acceleration, and the reference member. Distance detection means provided between the mass body or the elastic support member to detect the distance between the reference member and the mass body or the elastic support member, and the magnitude of acceleration based on the distance detection signal from the distance detection means. The acceleration detector may include an acceleration information output unit that outputs information indicating

Further, a housing having a gripping portion to be gripped by a human hand, a reference member fixed in the housing, and a mass body in the housing in the direction of receiving acceleration with respect to the reference member. Displacement-supporting elastic support member, and displacement detection provided between the reference member and the mass body or elastic support member, and detecting relative displacement between the reference member and the mass body according to the acceleration received by the reference member. There is also provided an acceleration detector including means and acceleration information output means for outputting information indicating the magnitude of the acceleration based on a displacement detection signal from the displacement detection means. In these acceleration detectors, the mass body can also serve as an electronic component including a circuit board that constitutes the acceleration information output means.

Furthermore, a housing having a gripping portion to be gripped by a human hand, a reference member fixed in the housing, and a direction in which the mass body is subjected to acceleration with respect to the reference member in the housing. A guide holding member for displaceably guiding and holding, a pair of coil springs for urging the mass body to the neutral position from both sides in the direction of receiving acceleration with respect to the reference member, and a reference member fixedly provided on the reference member side. Displacement detecting means for detecting the relative displacement of the reference member and the mass body according to the acceleration received by the member in a non-contact manner, and acceleration information for outputting information indicating the magnitude of the acceleration based on the displacement detection signal by the displacement detecting means. An acceleration detector having an output means is also provided.

[0018]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a vertical cross-sectional view of an acceleration detector showing a first embodiment of the present invention, and FIG. 2 is a plan view of a leaf spring having a mass body fixed thereto. In FIG. 1, a base member 1 which is an acceleration detection target member
The printed circuit board 2 is screwed onto the pair of protrusions 1a and 1b like the teeth of a geta, which are formed at intervals in the longitudinal direction.
And is fixed in parallel to the surface of the base member 1. The printed circuit board 2 also serves as a reference member that serves as a reference for detecting the above-mentioned acceleration.

On this printed circuit board 2, a base end portion 5a of a leaf spring 5 which is an elastic support member is fixed to a ridge 1a of a base member 1 by a co-tightening screw 3 which is common to the printed circuit board 2. The leaf spring 5 is bent in a crank shape from the base end portion 5a and rises up, and the intermediate portion 5b is formed on the printed circuit board 2
A mass body 6 made of a material having a large mass such as lead or iron is fixed to the upper surface of the tip portion 5c, which extends in parallel with, and is displaceable in a direction in which the base member 1 receives acceleration (direction of arrow A). I have a support.

When the leaf spring 5 to which the mass body 6 is fixed is viewed from above in FIG. 1, as shown in the plan view of FIG.
b is formed to be thin, and when the base member 1 receives an acceleration, it is easily deformed when the relative positional relationship between the two changes due to the inertial force of the mass body 6. Two screw holes 5d for inserting the screws 3 are formed in the base end portion 5a,
The tip portion 5c is formed in a size capable of sufficiently mounting the mass body 6.

A photo reflector 7 is fixedly mounted on the printed circuit board 2 below the tip 5c of the leaf spring 5. Then, a dome-shaped elastic body 8 made of an elastic material such as rubber and having a base fixed to the printed circuit board 2 is provided so as to cover the upper portion of the photo reflector 7, and a columnar pressing portion 8a provided on the upper portion thereof is provided. The lower surface of the tip end 5c of the leaf spring 5 is brought into contact with the lower surface of the leaf spring 5, and the pressing portion 8a is bent in a steady state so that the pressing portion 8a is slightly crushed. It can be displaced in any direction shown in A.

A reflective surface 9 is formed on the lower surface of the pressing portion 8a of the dome-shaped elastic body 8 by applying white coating or sticking a white piece. The photo-reflector 7 and the dome-shaped elastic body 8 constitute displacement detecting means and distance detecting means. These detection means are provided between the print base plate 2 which is a reference member and a portion of the leaf spring 5 which is an elastic support member that is displaced together with the mass body 6. When the mass body 6 is fixed to the lower surface side of the leaf spring 5, the photo reflector 7 and the dome-shaped elastic body 8 are provided between the Phnom substrate 2 and the mass body 6. A processing circuit 10 for driving the photo reflector 7 and processing a detection signal of the photo reflector 7 is also provided on the printed circuit board 2.

The photoreflector 7 is a reflection type photosensor, and as shown in FIGS. 3A and 3B, a light emitting element (light emitting diode) 7a and a light receiving element (phototransistor) 7b are spaced from each other on the upper surface. When a constant current If is passed through the light emitting element 7a to emit light, the light is reflected by the reflecting surface 9 and received by the light receiving element 7b. When a constant voltage Vc is applied to the light receiving element 7b, a photocurrent I that linearly changes with respect to the received light amount.
c is obtained.

The amount of light received depends on the distance d between the photo reflector 7 and the reflecting surface 9 shown in FIG.
The distance d can be known from the magnitude of the photocurrent Ic. Since this distance d corresponds to the distance D between the printed circuit board 2 which is the reference member shown in FIG. 1 and the tip 5c which is displaced together with the mass body 6 of the leaf spring 5, it is possible to detect a change in this distance D. Become. Since the change in the distance D corresponds to the acceleration, the acceleration information can be obtained from the photocurrent Ic flowing through the light receiving element 7b of the photo reflector 7.

To explain this in more detail, the mass 6
Is m, and the base member 1 receives the acceleration α,
The mass body 6 receives an inertial force F of F = mα. If the spring constant of the leaf spring 5 at the position of the mass body 6 is k, a displacement δ of δ = F / k = (m / k) · α occurs at that position. Since m / k is a constant, a displacement δ proportional to the acceleration α is generated.

In FIG. 1, assuming that the distance between the photo reflector 7 and the reflecting surface 9 of the dome-shaped elastic body 8 when the base member 1 is not subjected to acceleration is d1, and the distance when acceleration is received is d2, (d1 The magnitude of −d2) is the above displacement δ. This δ can be directly treated as a value proportional to the magnitude of acceleration. Therefore, the distance is d
The photocurrent Ic flowing through the light receiving element 7b shown in FIG. 3B when it is ₁ is Ic ₁ , and the photocurrent Ic when the distance is d2.
Is expressed as Ic ₂ , (Ic ₁ −Ic ₂ ) can be treated as a value proportional to the magnitude of the acceleration received by the mass body 6,
There is no factor that deteriorates the low frequency characteristics as when using a piezo element.

Moreover, since this photo reflector 7 is cheaper than the strain gauge element and is fixedly mounted on the printed circuit board 2, the work of connecting the processing circuit 10 with the connecting line becomes unnecessary, It is directly connected by the printed wiring on the printed circuit board 2.

An example of a circuit in which the photo reflector 7 and the processing circuit 10 are connected is shown in FIG. In FIG.
Reference numeral 11 is a + 5V positive voltage line, 12 is a ground line, and a light emitting element of the photo reflector 7 is provided between both lines.
(LED) 7a is connected in series with the protection resistor R1, and
The light receiving element (PT) 7b is connected in series to the emitter side thereof through a resistor R2 for current detection.

Further, the collector of the transistor TR is connected to the positive voltage line 11 via the resistor R4, the emitter is connected to the earth line 12, and the base is connected to the light receiving element 7b and the resistor R2 via the variable resistor R3. It is connected to point d. Further, if necessary, an A / D conversion circuit 13 is provided,
Alternatively, the inverting circuit 14 may be further provided between the connection point a and the A / D conversion circuit 13.

With this circuit configuration, the magnitude of the photocurrent Ic flowing in the light receiving element 7b of the photoreflector 7 according to the amount of received light is detected as the voltage across the terminals of the resistor R2, and the detected voltage is detected by the transistor TR. Inverted amplification is performed by an amplifier circuit using the resistor R4 and a voltage Va that is an analog output that is acceleration information is obtained from point a. Variable resistance R
3 is provided to adjust the offset value (reference value) of the voltage Va. Here, the offset value of the voltage Va is a voltage output when the acceleration detector is not receiving acceleration (when the leaf spring 5 is in the flat state shown in FIG. 1).

The acceleration detector shown in FIG. 1 is shown as a change in the voltage Va which is an analog output when the acceleration sensor shown in FIG. 1 is shaken up and down with the mass body 6 on the upper side and the base member 1 on the lower side. 5 shows.

When the acceleration detector is shaken upward from the stationary state,
According to the acceleration, the distance D between the mass body 6 and the printed circuit board 2 as the reference member decreases, and the amount of light received by the light receiving element 7b of the photo reflector 7 increases, so that the photocurrent Ic increases. As a result, the voltage at the point d rises, and the voltage Va at the point a obtained by inverting and amplifying the voltage falls from the offset value Va ₀ . When the acceleration decreases and reaches a constant speed, the distance D returns to the original value, and the voltage Va also returns to the offset value Va ₀ . Then slowly stop on top (acceleration becomes negative)
Then, when stopped, the mass body 6 tries to continue to further rise due to its inertial force, so that the distance D increases and the voltage Va rises, and then returns to the offset value Va ₀ .

When the acceleration detector is shaken downward from the stationary state,
The distance D between the mass body 6 and the printed circuit board 2 increases in accordance with the acceleration, and the light receiving element 7 of the photo reflector 7
Since the amount of light received by b decreases, the photocurrent Ic decreases. As a result, the voltage at the point d decreases, and the voltage Va at the point a obtained by inverting and amplifying the voltage rises from the offset value Va ₀ . When the acceleration decreases and reaches a constant speed, the distance D returns to the original value, and the voltage Va also returns to the offset value Va ₀ .

When it is suddenly stopped below (acceleration becomes a large negative value), the mass member 6 tries to continue lowering due to its inertial force, but the base member 1 suddenly stops, so that the distance D is suddenly decreased. Since the voltage at the point d sharply increases and the voltage Va at the point a sharply drops, the distance D rapidly returns due to the restoring force of the leaf spring 5, and the voltage Va also becomes a natural state after overshooting. It suddenly rises and returns to the offset value Va ₀ after overshooting (see FIG. 5). As is apparent from FIG. 5, when suddenly moved or stopped, the absolute value of the acceleration increases at that time, so that the voltage Va changes rapidly.

From the above description, the processing circuit 10 can be said to be acceleration information output means. The voltage Va, which is an analog output, may be output as it is as acceleration information to the utilization circuit of the external device. However, if the utilization circuit requires input of digital data, this voltage Va is
Converted to digital data by the / D conversion circuit 13,
It can also be output as acceleration information to a utilization circuit (not shown).

The voltage Va is a voltage that decreases as the distance between the leaf spring 5 and the printed circuit board 2 decreases and increases as the distance increases, but depending on the circuit used, it may be better to reverse the voltage. Therefore, in such a case, the voltage Va at the point a may be inverted by the inverting circuit 14 and output, or may be further converted into digital data by the A / D conversion circuit 13 and output. Further, by differentially amplifying the voltage at the point a and the offset value Va _0, it is possible to obtain an absolute value indicating only the magnitude of acceleration and a voltage output having a polarity indicating the direction of acceleration.

Using the output of this acceleration detector, that is, the acceleration information, for example, an electronic musical instrument, an automatic performance device, a karaoke device, a DTM (music) is set as a beat timing at an acceleration detection time of a predetermined value or more or an acceleration peak detection time.・ Tempo control and dynamics control of controller etc. can be performed.

Next, another embodiment of the present invention will be described. FIG. 6 is a side view of a main part of an acceleration detector according to a second embodiment of the present invention, in which parts corresponding to those in FIG. 1 are designated by the same reference numerals and are provided on the base member 1 and the printed circuit board 2. Illustration of the processing circuit 10 is omitted.

In this acceleration detector, the dome-shaped elastic body 8 in the acceleration detector shown in FIG. 1 is omitted, and the leaf spring 5 as an elastic supporting member is provided on the printed circuit board 2 as a reference member.
Facing the free end of the photo reflector 7
Instead of this, the light emitting diode (LED) 15 and the semiconductor position detecting element (PSD) are fixed at a predetermined interval. Then, the light emitted from the LED 15 is reflected by the lower surface of the leaf spring 5 toward the PSD 16 and is received by the PSD 16.

When the acceleration detector does not receive acceleration, the leaf spring 5 is in parallel with the printed circuit board 2 as shown by the solid line in FIG. 6, and the lower surface of the leaf spring 5 for the light emitted from the LED 15 at that time. The light receiving point on the PSD 16 of the reflected light by is set to the point a at the center in the longitudinal direction.

When the acceleration detector receives acceleration in the direction of arrow A, the mass body 6 is fixed to the base member (not shown) as described above due to the relationship between the inertial force of the mass body 6 and the force received by the acceleration. Since it is displaced relative to the printed circuit board 2, the tip end of the leaf spring 5 supporting the mass body 6 is moved downward as shown by a chain double-dashed line in FIG. Bend upward as indicated by the dashed line. Thereby, the leaf spring 5 of the light emitted from the LED 15
The light receiving point on the PSD 16 of the light reflected by the lower surface of the above moves to the point b or the point c depending on the degree of the bending, that is, the magnitude of the acceleration.

Since the ratio of the currents drawn from the electrodes at both ends of the PSD 16 changes depending on the position of the light receiving point, the relative displacement amount of the mass body 6 with respect to the printed circuit board 2, that is, the magnitude of the acceleration is detected by detecting the ratio. You can get direction information. In this case, the LED 15 and the PSD 16 serve as a displacement detection unit that detects a relative displacement due to an inertial force according to the acceleration received by the mass body 6. Also,
Instead of the PSD 16, a light receiving element array in which a plurality of light receiving elements (phototransistors) are arranged linearly may be used. In the present technology, the element interval can be set to 1 to 2 mm, so that the output of each light receiving element can be directly extracted as digital position information.

FIG. 7 is a side view of a main part of an acceleration detector showing a third embodiment of the present invention. The parts corresponding to those in FIG. 1 are designated by the same reference numerals, and the base member 1 and the printed circuit board are shown. 2. The upper processing circuit 10 is not shown. In this speed detector, a gray chart (also referred to as gray scale) plate 17 is vertically fixed to the tip of a leaf spring 5 supporting a mass body 6 near the tip, and the gray chart plate 17 is fixed.
The transmission type photo interrupter 18 is fixedly mounted on the printed circuit board 2 via a supporting piece 19 which is bent in a crank shape so as to sandwich it.

The light transmittance of the gray chart plate 17 changes from 0 to 100% from the lower end to the upper end in FIG.
The transmissive photo interrupter 18 is a gray chart plate 1
A light emitting element is provided on one side sandwiching 7 and a light receiving element is provided on the other side, and a photocurrent corresponding to the amount of light passing through the gray chart plate 17 flows through the light receiving element. Therefore, by detecting the magnitude of the photocurrent, the position of the gray chart plate 17 in the direction of the arrow A, that is, the relative movement of the mass body 6 on the printed circuit board 2 when the acceleration in the direction of the arrow is received. Information on the amount of displacement, that is, the magnitude and direction of acceleration can be obtained.

In this case, the gray chart plate 17 and the transmissive photo interrupter 18 are displacement detecting means for detecting the displacement according to the acceleration received by the acceleration detector.
In addition, the transmissive photo interrupter 18 and the printed circuit board 2
Since the connection with the processing circuit (not shown) can be performed by a wiring pattern formed on the support piece 19 or a flat cable along the support piece 19, there is no risk of disconnection. The acceleration detection target member in each of these embodiments is not limited to the flat plate-shaped base member as shown in FIG. 1, but can be formed in various shapes, and can be fixed in a device or an object whose acceleration is to be detected. It can also be installed or stored in a dedicated housing.

8 and 9 are an external view showing a state in which the acceleration detector according to the fourth embodiment of the present invention is held by a hand, and an enlarged vertical sectional view of a main part thereof. This acceleration detector is suitable for performing tempo control and dynamics control of sounds generated by the electronic musical instrument described above.

The acceleration detector 30 shown in FIG. 8 is a housing 31 having a grip portion 31a that is to be gripped by a person's hand 40, in which the acceleration detection target member has a shape like a short baseball butt. Each member for detecting acceleration, a signal processing circuit, and the like are all built in the housing 31, and the detected acceleration information is sent to a device to be used through a code 32. Instead of using the code 32, a wireless transmission circuit may be added to the processing circuit and the acceleration data may be wirelessly transmitted to the utilization circuit (utilization device).

The housing 31 is formed of resin or the like by being divided into, for example, two parts, that is, an upper part and a lower part. When using the acceleration detector 30, the user holds the housing 3 with his / her hand 40.
By grasping the one grasping portion 31a and swinging the grasping portion 31a up and down, information corresponding to the change in the acceleration can be sent to the utilization device.

The internal structure of this acceleration detector will be described with reference to FIG. 9. In FIG. 9 as well, substantially the same parts as those in FIG. 1 are designated by the same reference numerals, and a description thereof will be omitted. The printed circuit board 2 serving as a reference member inside the large-diameter portion from the tip of the housing 31 via a plurality of spacer members 39.
Is fixed horizontally parallel to the axis L of the housing 31.

A cylindrical body 33 is vertically erected on the upper surface of the printed circuit board 2 near the end of the housing 31 close to the tip thereof, and a mass body 34 is housed in the cylindrical body 33 in the direction of receiving acceleration (arrow). It is held so that it can be displaced in the direction A). That is, the tubular body 33 is a guide holding member for the mass body 34. In the mass body 34, a cylindrical portion 34a that is in sliding contact with the inner surface of the cylindrical body 33 and a cylindrical portion 34b along the central axis thereof are integrally formed with a material having a large mass such as iron in a vertically symmetrical shape. Grease is applied to the outer surface of the cylindrical portion 34a of the mass body 34 and the inner surface of the cylindrical body 33 to reduce frictional resistance during sliding.

At the upper and lower ends of the tubular body 33, a pair of tubular spring receivers 37 and 38 are fixedly mounted concentrically with the tubular body 33, and the spring bearings 37 and 38 and the mass body 34 are connected to each other. A pair of coil springs 35 and 36 are engaged between them to urge the mass body 34 from both sides in the direction of receiving acceleration with respect to the housing 31 to the neutral position in the figure. The cylindrical portion 34 of the mass body 34
A reflecting surface 9 is provided on the lower end surface of the substrate b, and is opposed to the photo reflector 7 fixed on the printed circuit board 2.

According to this speed detector 30, when the housing 31 is shaken in the direction of arrow A (vertical direction in the figure), the mass body 34 which receives an inertial force in accordance with the acceleration of the housing 31 has coil springs 35,
It slides in the cylindrical body 33 against the urging force of the casing 36,
And the relative position with respect to the printed circuit board 2 fixed to it is displaced. That is, the distance between the photo reflector 7 and the reflection plate 9 changes, and the magnitude of the photocurrent flowing through the light receiving element of the photo reflector 7 by the processing circuit 10 is changed according to the change, as in the case of the first embodiment. Information indicating the received acceleration can be output by processing such as converting the voltage into a voltage and amplifying the voltage.

In this example, the reflecting surface 9 is provided only on the lower end surface of the cylindrical portion 34b of the mass body 34, and one photo reflector 7 is provided on the printed circuit board 2 so as to face it, but the mass body 34 is provided. A reflecting surface may be formed also on the upper end surface 34c of the cylindrical portion 34b, and the photoreflector 7'may be arranged on the inner surface of the upper end portion of the cylindrical body 33 so as to face it, as indicated by a phantom line. .

In that case, both photo reflectors 7,
If the output of 7'is differentially sent to the processing circuit 10, a large output can be obtained and the mechanical and electrical non-linear characteristics are respectively compensated, and the compensating circuit can be eliminated. The compensating circuit can have a simple structure, and the matching with the circuit to be used can be achieved quickly.

Further, by using two dome-shaped elastic bodies similar to the dome-shaped elastic body 8 used in the example shown in FIG. 1, the mass body 34 in FIG. 7 is sandwiched from above and below, and pre-compression is applied to the dome-shaped portion. (Preload) is applied to set, a reflecting surface is formed on the inner end surface of at least one of the upper and lower dome-shaped elastic bodies, and the reflecting surface is opposed to the printed board 2 and / or the cylindrical shape. The photo reflector 7 may be fixed to the inner surface of the end portion of the body 33.

FIG. 10 is a vertical sectional view similar to FIG. 9 of the acceleration detector showing the fifth embodiment of the present invention, and FIG. 11 is a perspective view of the leaf spring support fitting. Like the acceleration detector 30 described above, the acceleration detector 40 shown in FIG. 10 also has a shape like a shortened baseball ball, and has a casing having a grip portion (not shown) to be gripped by a human hand. All members for detecting acceleration, a signal processing circuit, and the like are built in the body 41, and the detected acceleration information is sent to a device to be used through a code or by wireless communication.

Inside the large-diameter portion from the tip of the acceleration detector 40, as shown in FIG. 10, a pair of support portions 41a are integrally formed with the casing 41 at intervals along the axis L thereof.
41b is formed in a semicircular shape in the radial direction, and a high-rigidity reference plate 42, which is a reference member, is provided on the upper surface thereof with screws 43, 43.
Are fixed along the axis L.

A plate spring support fitting 44 is fixed to the reference plate 42. As shown in FIG. 11, the leaf spring support metal fitting 44 is formed by bending an iron plate having high rigidity.
a and a leaf spring mounting portion 4 horizontally extending from both ends thereof
The vertical portion 44a is formed in a U-shape including 4b and 44c.
44d and attachment piece 44e by cutting and raising in the central city of
Is formed. The mounting hole 44 is attached to the mounting piece 44e.
f is provided with a plurality of screw holes 44g in the upper and lower leaf spring mounting portions 44b and 44c.

The opening 4 of the leaf spring support fitting 44 is
The reference plate 42 is inserted into the 4d, and the screw 45 is attached to the mounting piece 44e.
Is inserted into the mounting hole 44f of the reference plate 42 and is screwed into a screw hole (not shown) of the reference plate 42 to fix the plate spring support fitting 44 to the reference plate 42. The plate spring support fittings 4 and 4 may be directly fixed together with the reference plate 42 by the support portion 41a screw 43 of the housing 41.

Each leaf spring mounting portion 44 of the leaf spring support fitting 44
b and 44c are leaf springs 4 which are elastic supporting members, respectively.
6, 46 'are fixed at one end with screws 47, 47', and the circuit boards 48, 48 'of the processing circuits 10, 10' are attached to the other ends of the leaf springs 46, 46 ', respectively.
It is fixed by 9,49 '. In this embodiment,
The circuit boards 48, 48 'constituting the processing circuits 10, 10' including the acceleration information output means and the various electronic components 50, 50 'mounted thereon also serve as the mass bodies in the above-described embodiments.

The processing circuits 10 and 10 'have the same structure as the circuit shown in FIG.
Is its transistor TR and resistors R1, R2, R
4. If the variable resistor R3 and the A / D conversion circuit 13 and the inverting circuit 14 are provided, the transistors, resistors, etc. constituting them are also included. The function of the mass body is enhanced by collecting these electronic components as close to the tip portions (right end portions in FIG. 10) of the circuit boards 48 and 48 'as possible.

Then, the photo reflector 51 and the dome-shaped elastic body 52 are mounted on the lower surface of the upper circuit board 48, and the contact member 53 for contacting the lower end surface thereof is fixed to the upper surface of the reference plate 42. A displacement detecting means or a distance detecting means between the reference plate 42, the circuit board 48 forming the mass body, and the electronic component 50 is configured.

Similarly, the photo reflector 51 'and the dome-shaped elastic body 52' are mounted on the upper surface of the lower circuit board 48 ', and the abutting member 53' abutting on the lower end surface of the photo reflector 51 'is attached to the reference plate 42.
Is fixed to the lower surface of the base plate 42, which constitutes a displacement detecting means or a distance detecting means between the reference plate 42 and the circuit board 48 'and the electronic component 50' which form a mass body.
The circuit board 48 and the circuit board 48 'are connected by a flat cable 55.

According to this speed detector 40, when the housing 41 is shaken in the direction of arrow A (vertical direction in the figure), the circuit board 48 and the electronic component 5 which act as a mass body in accordance with the acceleration thereof.
0 and the circuit board 48 ′ and the electronic component 50 ′ receive an inertial force to bend the leaf springs 46 and 46 ′ respectively, so that one of the circuit boards 48 and 48 ′ moves relatively close to the reference plate 42. Then, the other is relatively displaced so as to be separated from the reference plate 42.

Therefore, the photo reflectors 51 and 51 'are
Thus, a signal corresponding to the relative displacement of the circuit boards 48 and 48 'with respect to the reference plate 42 in the opposite direction is detected according to the magnitude of the acceleration received by the speed detector 40. Therefore, if the outputs of both photoreflectors 51 and 51 'are operated and amplified by the processing circuit 10 or 10', a large output can be obtained, and acceleration information in which mechanical and electrical nonlinear characteristics are compensated is obtained. Will be obtained.

In this embodiment, as described above, the electronic components 50 and 50 'themselves including the circuit boards 48 and 48' of each processing circuit 10 or 10 'also serve as a mass body (inertial body). , These parts are collected on the tip end side when the housing 41 is swung in the direction of arrow A, where large acceleration is generated, and it is not necessary to provide an extra mass body. The degree will be limited.

Therefore, in order to increase the degree of freedom in design, all the electronic components mounted on each circuit board 48 or 48 'are put in one package, and the package is filled with an adhesive to form one component. Can be Then, each package is finished into a mass body having a uniform center of gravity. The center of gravity may be eccentric, but each package must have the same eccentricity. Furthermore, the processing circuit using these electronic components may be integrated into an IC or an LSI.

When the mass as the mass body is insufficient, an additional mass body is added to the circuit board 48 or 48 'at a predetermined position (preferably at the free end side) or the leaf spring 46 or 4.
It is fixed to the free end side of 6'by an adhesive or a screw. By doing so, the detection sensitivity does not differ for each product. That is, there is no need to perform sensitivity adjustment work for each product. That is, the electronic components can be mounted on the circuit boards 48, 48 'as if the mass body 6 in FIG. 1 is mounted on the leaf spring 5. If the desired mass cannot be obtained with only the circuit board and electronic components, a mass body may be additionally provided.

In any of the above-described embodiments of the present invention, the relative displacement of the mass body with respect to the reference member or the relative distance between the leaf spring and the reference member deformed by the displacement is detected according to the acceleration received by the acceleration detector. Therefore, the acceleration information can be obtained without subjecting the detection signal to high-pass processing or integration processing, there is no factor causing deterioration of the low frequency characteristic, and the processing circuit can be simple.

As the displacement or distance detecting means, an inexpensive sensor such as a photo reflector can be used. Further, if the sensor is fixed to the reference member side, excessive stress is not applied and there is no risk of damage. Further, since the sensor and the processing circuit for the detection signal thereof can be provided on the same printed circuit board, wiring by a connecting line is not required, which not only reduces the working cost but also eliminates the possibility of disconnection.

[0071]

As described above, the acceleration detector according to the present invention can accurately detect acceleration by using a sensor for displacement or distance detection which is inexpensive and has a good low frequency characteristic. In addition, it is possible to eliminate the risk of disconnection or destruction of the element. If the acceleration detection target member is a housing having a gripping portion that can be gripped by a human hand, and if all the members and processing circuits necessary for acceleration detection are built in the housing, the operability is good and the It is most suitable for tempo control and dynamics control of generated sound.

Furthermore, without using a special mass body,
It is also possible to detect acceleration by using an electronic component including a circuit board forming a processing circuit for outputting information indicating the magnitude of acceleration from an output signal of the sensor as the mass body.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an acceleration detector showing a first embodiment of the present invention.

FIG. 2 is a plan view of a leaf spring to which a mass body is fixed in the acceleration detector of FIG.

FIG. 3 is an explanatory diagram of a photo reflector 7 in FIG.

FIG. 4 is a circuit diagram in which the photo reflector 7 and a processing circuit 10 are connected.

5 is a waveform diagram showing a change in voltage Va output from point a of FIG. 4 due to acceleration.

FIG. 6 is a side view of a main part of an acceleration detector according to a second embodiment of the present invention.

FIG. 7 is a side view of a main part of an acceleration detector according to a third embodiment of the present invention.

FIG. 8 is an external view showing a state where an acceleration detector according to a fourth embodiment of the present invention is held by a hand.

FIG. 9 is an enlarged vertical cross-sectional view of the main part of the same.

FIG. 10 is an enlarged vertical sectional view of an essential part of an acceleration detector showing a fifth embodiment of the invention.

11 is a perspective view of the leaf spring support fitting 44 in FIG.

FIG. 12 is a vertical sectional view similar to FIG. 1, showing an example of a conventional acceleration detector.

FIG. 13 is an explanatory diagram for explaining the dimensional change of the surface due to the bending of the leaf spring when the same is subjected to acceleration.

[Explanation of symbols]

1 ... Base member (acceleration detection target member), 2 ... Printed circuit board (reference member), 3, 4 ... Screw, 5 ... Leaf spring (elastic support member), 6 ... Mass body, 7 ... Photo reflector, 7a ...
Light emitting element, 7b ... Light receiving element, 8 ... Domed elastic body, 9 ...
Reflective surface 10, 10 '... Processing circuit, 30, 40 ... Acceleration detector, 31, 41 ... Housing (acceleration detection target member), 3
2 ... Cord, 33 ... Cylindrical body (guide holding member), 34 ... Mass body, 35, 36 ... Coil spring (elastic support member), 3
7, 38 ... Spring receiver, 39 ... Spacer member, 42 ... Reference plate (reference member), 44 ... Leaf spring support fitting, 46, 46 '
... Leaf springs (elastic support members), 48, 48 '... Circuit boards,
50, 50 '... Electronic parts, 51, 51' ... Photo reflector, 52, 52 '... Dome-shaped elastic member hand, 53, 5
3 '... abutting member, 55 ... flat cable,

Claims (5)

[Claims] 1. A reference member and a mass body, an elastic support member that supports the mass body so as to be displaceable in a direction in which the reference member is subjected to acceleration, and between the reference member and the mass body or the elastic support member. Displacement detecting means provided for detecting relative displacement between the reference member and the mass body according to the acceleration received by the reference member, and information indicating the magnitude of the acceleration based on a displacement detection signal from the displacement detecting means. And an acceleration information output means for outputting 2. A reference member and a mass body; an elastic support member having a base end portion fixed to the reference member, and a distal end portion movably supporting the mass body in a direction in which the reference member receives acceleration; Distance detection means provided between the reference member and the mass body or the elastic support member for detecting the distance between the reference member and the mass body or the elastic support member, and a distance detection signal by the distance detection means. An acceleration detector, comprising: acceleration information output means for outputting information indicating the magnitude of the acceleration based on the acceleration information output means. 3. A housing having a gripping portion to be gripped by a human hand, a reference member fixed in the housing, and a direction in which the mass body is subjected to acceleration with respect to the reference member in the housing. Is provided between the elastic support member and the reference member and the mass body or the elastic support member, and detects the relative displacement between the reference member and the mass body according to the acceleration received by the reference member. An acceleration detector comprising: a displacement detecting means; and an acceleration information output means for outputting information indicating the magnitude of the acceleration based on a displacement detection signal from the displacement detecting means. 4. The acceleration detector according to claim 1, wherein the mass body is an electronic component including a circuit board that constitutes the acceleration information output means. vessel. 5. A housing having a gripping portion to be gripped by a human hand, a reference member fixedly provided in the housing, and a mass body in the housing in a direction of receiving acceleration with respect to the reference member. A guide holding member that guides and holds the mass member in a displaceable manner, a pair of coil springs that bias the mass body to a neutral position from both sides in the direction of receiving acceleration with respect to the reference member, and fixed to the reference member side. Displacement detecting means for detecting relative displacement between the reference member and the mass body according to the acceleration received by the reference member, and information indicating the magnitude of the acceleration based on a displacement detection signal from the displacement detecting means An acceleration detector, comprising: