Priority is claimed on Japanese Patent Application No. 2020-023174, filed Feb. 14, 2020, the contents of which are incorporated herein by reference.
The present invention relates to an impact detection device and a percussion instrument.
Japanese Patent Publication No. 3933566 (hereinafter referred to as Patent Document 1) discloses a percussion instrument in which a vibration sensor (piezoelectric element) for detecting vibration of a body to be struck (head) due to an impact or the like. The vibration sensor is held between the body to be struck and a support base (frame). In this percussion instrument, an elastic body (cushion material) is sandwiched between the vibration sensor and the body to be struck, and between the vibration sensor and the support base.
However, in the percussion instrument of Patent Document 1 there is a problem in that the degree of freedom of vibration of the vibration sensor is low because the movement (vibration) of the vibration sensor accompanying the impact on the body to be struck is restricted by the elastic body.
The present invention has been made in view of the above circumstances. A one object of the present invention is to provide an impact detection device and a percussion instrument that can hold the vibration sensor against the body to be struck, and improve the degree of freedom of the vibration of the vibration sensor accompanying an impact on the body to be struck.
According to a first aspect of the present invention, an impact detection device includes: a body configured to be struck; a vibration sensor that detects vibration of the body; a support base that supports the vibration sensor; a first elastic body sandwiched between the vibration sensor and the body; and a second elastic body sandwiched between the vibration sensor and the support base. A dimension of each of the first elastic body and the second elastic body is smaller than a dimension of the vibration sensor when viewed from an arrangement direction in which the first elastic body, the vibration sensor, and the second elastic body are arranged.
According to a second aspect of the present invention, a percussion instrument includes: a support member; and an impact detection device resting on the support member and including: a body configured to be struck; a vibration sensor that detects vibration of the body; a support base that supports the vibration sensor; a first elastic body sandwiched between the vibration sensor and the body; and a second elastic body sandwiched between the vibration sensor and the support base. A dimension of each of the first elastic body and the second elastic body is smaller than a dimension of the vibration sensor when viewed from an arrangement direction in which the first elastic body, the vibration sensor, and the second elastic body are arranged.
Hereinafter, one embodiment of the present invention will be described with reference to
As shown in
The body to be struck 2 has a striking surface 2a that is struck by a stick or the like. The body to be struck 2 of this embodiment is formed in a plate shape. Further, the body to be struck 2 includes an elastic sheet portion 21 and a support plate portion 22 which are overlapped in the thickness direction thereof. The elastic sheet portion 21 is made of an elastic body such as silicon rubber. The support plate portion 22 has a higher elastic modulus than the elastic sheet portion 21 and is made of as a metal or the like. The striking surface 2a of the body to be struck 2 is formed by (the surface of) the elastic sheet portion 21. Further, a surface 2b (back surface 2b) of the body to be struck 2 facing the opposite side to the striking surface 2a, is formed by (the surface of) the support plate portion 22. The axis in
The shape of the body to be struck 2 seen from the thickness direction is not limited to a circular shape, but may be an arbitrary shape such as a polygonal shape. Further, the body to be struck 2 may be a head formed in a membrane shape such as a film.
The vibration sensor 3 detects the vibration of the body to be struck 2 accompanying an impact on the body to be struck 2 (that is, the vibration of the body to be struck 2 corresponding to an impact on the body to be struck 2). The vibration sensor 3 is a piezoelectric sensor that outputs an electric signal corresponding to the vibration. The vibration sensor 3 is formed in a plate shape or a membrane shape. The vibration sensor 3 may be, for example, a sensor using a polyvinylidene fluoride (PVDF) film or an electret. In this embodiment, the vibration sensor 3 is arranged on the back surface 2b side of the body to be struck 2. Further, the plan view shape of the vibration sensor 3 seen from the thickness direction (vertical direction in
The vibration sensor 3 may be arranged on the striking surface 2a side of the body to be struck 2, for example. Further, the plan view shape of the vibration sensor 3 may be any shape such as a polygonal shape.
As shown in
The support base 4 may be, for example, a double-sided beam in which only both ends in the longitudinal direction are fixed to the body to be struck 2. In this case, the vibration sensor 3 may be arranged at a portion of the support base 4 between both ends.
The first elastic body 5 is sandwiched between the vibration sensor 3 and the body to be struck 2. The second elastic body 6 is sandwiched between the vibration sensor 3 and the support base 4. The first elastic body 5 and the second elastic body 6 sandwich the vibration sensor 3 from the thickness direction thereof. As a result, the vibration sensor 3 is held between the body to be struck 2 and the support base 4.
The elastic moduli of the first and second elastic bodies 5 and 6 are smaller than the elastic moduli of the body to be struck 2 and the support base 4. That is, the first and second elastic bodies 5 and 6 are more easily deformed elastically than the body to be struck 2 and the support base 4. The first and second elastic bodies 5 and 6 are, for example, rubber or sponge.
In this embodiment, the dimensions of the first elastic body 5 and the second elastic body 6 are equal to each other when viewed from the arrangement direction of the first elastic body 5, the vibration sensor 3, and the second elastic body 6 (vertical direction in
The dimensions of the first elastic body 5 and the second elastic body 6 as seen from the arrangement direction of the first elastic body 5, the vibration sensor 3, and the second elastic body 6 are smaller than the dimension of the vibration sensor 3. It is sufficient that the dimensions of the portions of the first and second elastic bodies 5 and 6 that contact the vibration sensor 3 is at least smaller than the dimension of the surface of the vibration sensor 3 with which the first and second elastic bodies 5 and 6 come into contact.
Further, in this embodiment, the center C3 of the vibration sensor 3, the center C5 of the first elastic body 5, and the center C6 of the second elastic body 6 coincide with each other when viewed from the arrangement direction. Further, as shown in
The center C3 of the vibration sensor 3 and the centers C5 and C6 of the first and second elastic bodies 5 and 6 may be positioned offset from the center C2 of the body to be struck 2, for example. Further, the center C5 of the first elastic body 5 and/or the center C6 of the second elastic body 6 may be positioned offset from the center C3 of the vibration sensor 3. Further, the centers C5 and C6 of the first and second elastic bodies 5 and 6 may be positioned so as to be offset from each other.
The first elastic body 5 is bonded to the vibration sensor 3 and the body to be struck 2, respectively. In this embodiment, the entire region of the first facing surface 5a of the first elastic body 5 facing the vibration sensor 3 is bonded to the vibration sensor 3. Further, the entire region of the second facing surface 5b of the first elastic body 5 facing the body to be struck 2 is bonded to the body to be struck 2. The second elastic body 6 is bonded to the vibration sensor 3 and the support base 4, respectively. In this embodiment, the entire region of the first facing surface 6a of the second elastic body 6 facing the vibration sensor 3 is bonded to the vibration sensor 3. Further, the entire region of the second facing surface 6b of the second elastic body 6 facing the support base 4 is bonded to the support base 4. The adhesive layer (not shown) for adhering the first and second elastic bodies 5 and 6 to the body to be struck 2, the vibration sensor 3, and the support base 4 may be an adhesive, a double-sided tape, or the like.
In the impact detection device 1 of this embodiment, when the body to be struck 2 is struck, the vibration of the body to be struck 2 is transmitted to the vibration sensor 3 via the first elastic body 5. Further, the vibration of the body to be struck 2 is transmitted to the vibration sensor 3 via the support base 4 and the second elastic body 6. As a result, the vibration sensor 3 vibrates and outputs a signal corresponding to the vibration, and a sound source unit (not shown) processes the output signal from the vibration sensor 3 and outputs the sound signal to a speaker (not shown). The speaker emits a sound corresponding to the sound signal.
As described above, according to the impact detection device 1 of this embodiment and the percussion instrument 100 including the impact detection device 1, the vibration sensor 3 is sandwiched between the body to be struck 2 and the support base 4 via the first elastic body 5 and the second elastic body 6. As a result, the vibration sensor 3 can be held with respect to the body to be struck 2.
Further, in the impact detection device 1 and the percussion instrument 100 of this embodiment, the dimensions of the first elastic body 5 and the second elastic body 6 as seen from the arrangement direction of the first elastic body 5, the vibration sensor 3, and the second elastic body 6 are smaller than the dimension of the vibration sensor 3. That is, the vibration sensor 3 has a portion that is not sandwiched between the first elastic body 5 and the second elastic body 6. Therefore, it is possible to prevent the vibration of the vibration sensor 3 accompanying an impact on the body to be struck 2 from being restricted by the first and second elastic bodies 5 and 6. That is, the degree of freedom of vibration of the vibration sensor 3 can be improved. In particular, the sensitivity of the vibration sensor 3 to high frequency vibration can be improved. As a result, a higher frequency signal is input from the vibration sensor 3 to the sound source unit, so that the response speed in the sound source unit can be improved. That is, it is possible to suppress a time lag between striking the body to be struck 2 and emitting a sound in the speaker.
Further, since vibration in a wider frequency band is detected by the vibration sensor 3, the information obtained from the vibration sensor 3 increases, so that it is possible to correspond to various musical expressions. For example, by detecting the vibration in a wide frequency band by the vibration sensor 3, a difference is likely to appear in the vibration waveform detected by the vibration sensor 3 depending on the striking position on the striking surface 2a of the body to be struck 2. This makes it possible to estimate the striking position on the striking surface 2a of the body to be struck 2. By being able to estimate the striking position, for example, different sound signals can be output to the speaker depending on the striking position.
Further, in the impact detection device 1 of this embodiment, the support base 4 is fixed to the body to be struck 2. As a result, vibration in a wider frequency band can be detected by the vibration sensor 3. Further, since the body to be struck 2 and the support base 4 are (directly) connected with each other without sandwiching a separate member therebetween, the impact detection device 1 and the percussion instrument 100 can be compactly configured.
Moreover, in the impact detection device 1 of this embodiment, the body to be struck 2 includes the elastic sheet portion 21 made of an elastic body, and the support plate portion 22 that has a higher elastic modulus than the elastic sheet portion 21 and is overlaid on the elastic sheet portion 21 in the thickness direction thereof. As a result, vibration in a wider frequency band can be detected by the vibration sensor 3.
Further, in the impact detection device 1 of this embodiment, the center C3 of the vibration sensor 3, the center C5 of the first elastic body 5, and the center C6 of the second elastic body 6 coincide with each other when viewed from the arrangement direction of the first elastic body 5, the vibration sensor 3, and the second elastic body 6. Therefore, when the vibration sensor 3 is sandwiched between the first elastic body 5 and the second elastic body 6, it is possible to prevent the vibration sensor 3 from tilting and coming into contact with the body to be struck 2 or the support base 4. That is, the vibration sensor 3 can be stably sandwiched between the first elastic body 5 and the second elastic body 6.
Moreover, in the impact detection device 1 of this embodiment, the center C3 of the vibration sensor 3 and the centers C5 and C6 of the first and second elastic bodies 5 and 6 coincide with the center C2 of the body to be struck 2 when viewed from the arrangement direction. As a result, compared to a case where the center C3 of the vibration sensor 3 and the centers C5 and C6 of the first and second elastic bodies 5 and 6 are offset from the center C2 of the body to be struck 2, the sensitivity of the vibration sensor 3 to striking of the body to be struck 2 can be further improved.
Further, in the impact detection device 1 of this embodiment, the support base 4 is sufficiently rigid. That is, the support base 4 is less likely to be deformed than the first and second elastic bodies 5 and 6. Therefore, it is less likely for the high frequency vibration accompanying the impact on the body to be struck 2 to be absorbed by support base 4. As a result, the vibration sensor 3 can detect vibrations of higher frequencies.
Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention.
In some embodiments, for example, as shown in
In some embodiments, the support base 4 may be a cantilever beam in which only a first end portion 41 in the longitudinal direction is fixed to the body to be struck 2, as shown in
In such a configuration, as compared with the case where the support base 4 has a bowl shape or a double-sided beam as in the above embodiment, the support base 4 (particularly the portion excluding the first end portion 41) is more likely to vibrate with the vibration of the body to be struck 2. As a result, it is possible to prevent the vibration of the vibration sensor 3 accompanying an impact on the body to be struck 2 from being restricted by the support base 4. That is, the degree of freedom of vibration of the vibration sensor 3 can be further improved.
In some embodiments, for example, as shown in
In the configurations illustrated in
Further, in the configuration illustrated in
The shape of the adhesive layer 7 in a plan view may be a circular shape as illustrated in
In some embodiments, for example, as shown in
In the configuration illustrated in
As illustrated in
Further, in a case where only an area on a part of the second facing surface 5b of the first elastic body 5 facing the body to be struck 2 is bonded to the body to be struck 2, then compared to the case where the entire second facing surface 5b of the first elastic body 5 is bonded to the body to be struck 2, it is possible to prevent the vibration of first elastic body 5 accompanying an impact on the body to be struck 2 from being restricted by the body to be struck 2. As a result, the vibration accompanying an impact on the body to be struck 2 can be efficiently transmitted from the body to be struck 2 to the vibration sensor 3 through the first elastic body 5.
Further, in a case where only an area on a part of the second facing surface 6b of the second elastic body 6 facing the support base 4 is bonded to the support base 4, then compared to the case where the entire second facing surface 6b of the second elastic body 6 is bonded to the support base 4, it is possible to prevent the vibration of the second elastic body 6 accompanying an impact on the body to be struck 2 from being restricted by the support base 4. As a result, the vibration accompanying an impact on the body to be struck 2 can be efficiently transmitted from the support base 4 to the vibration sensor 3 through the second elastic body 6.
In some embodiments, for example, only one of the first elastic body 5 and the second elastic body 6 may be bonded to the vibration sensor 3, and the other may not be bonded to the vibration sensor 3.
According to some embodiments of the present invention, the vibration sensor can be held with respect to the body to be struck, and the degree of freedom of vibration of the vibration sensor accompanying an impact on the body to be struck can be improved.
Number | Date | Country | Kind |
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2020-023174 | Feb 2020 | JP | national |
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Number | Date | Country | |
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20210256946 A1 | Aug 2021 | US |