JPH0224147Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) This invention relates to a toy piano.

(Prior Art and Problems with the Prior Art) In most conventional toy pianos, the sounding body is a cantilever vibrating sound piece that is supported at one end and free at the other end. In this case, the base body to which one side of the vibrating bar is fixed is made of cast metal or the like, and the vibrating bar is inserted, press-fitted, or screwed into the base body. For this reason, there was severe refraction at the boundary point between the base body and the sound piece, and even when tuned to the correct scale frequency, the frequency would quickly go awry, making it undesirable as a toy given to young children.

On the other hand, there is a proposal to use a toy piano's sounding body as a tone piece that vibrates freely at both ends, that is, supports two points in the vicinity of about 22.4% from both ends of a pipe, rod, or plate.
However, this type of toy piano had the following drawbacks.

(1) If the two-point support of a sound piece such as a pipe, rod, or plate is supported firmly, it will not vibrate easily, but if the support is not strong, it will vibrate easily, but if the sound piece moves and the side plate etc. There have been problems in which the sound pieces come into contact with case parts and no longer produce sound, or the sound pieces come off from the support. This lacks robustness as a toy for young children that will be handled roughly.

(2) When using a sound source that vibrates freely at both ends, for example, consider a pipe-shaped sound piece, the disadvantage is that it sounds well in a certain range, that is, the volume is large, but the volume decreases as you move from this range to other ranges. be. In general, the bass part is difficult to hear. Therefore, many toys have conventionally been used only for a limited number of easy-to-sound ranges around one octave.
There was a problem in that it was difficult to maintain a constant volume level over several octaves like a toy piano. In particular, since they must be arranged side by side within dimensions determined by the width of the keyboard, the diameter of the pipes must remain constant, and it is impossible to increase the volume by changing the diameter of the pipes. This is especially difficult for toy pianos, which require small size, light weight, and low cost.

FIG. 1 is a diagram of a conventional example in which a toy piano case is equipped with free vibrating sound pieces at both ends.

When the key 2 is pressed, the rear end 2a moves upward, pushing up the hammershank 7 attached to the hammershank rail 6. A hammer 3 is attached to the tip of the hammer shank 7, and this hammer 3
is configured to strike a sound piece 1 made of a circular or elliptical tube made of iron or aluminum to produce a scale sound of a desired frequency. Note that the vibrating bar 1 is not limited to a circular tube or an elliptical tube. Sound piece 1 is one key 2
A large number of sound pieces 1 are arranged in parallel at required intervals, and the sound pieces 1 are long for bass sounds and short for high sounds. Each vibrating bar 1 is supported by a long elastic body 5 made of foamed urethane or neoprene foamed rubber in the vicinity of two points corresponding to nodes of the first mode of free vibration at both ends thereof. The lower surfaces of these long elastic bodies are glued (adhesive adhesive may also be used) to the support base member 8, and the upper surfaces thereof are coated with adhesive, and each sound piece 1 is attached to the elastic body 5. It is adhesively fixed to the upper surface, and the interval between adjacent vibrating bars 1 is maintained at a required dimension.

The support member 8 is long and fixed to the side plates of the case in order to support all the sound pieces 1. The same applies to the hammershank rail 6.

As with the lower part, an elastic body 11 made of foamed synthetic rubber such as urethane or neoprene is adhered to the upper surface of the supporting portion of the vibrating bar 1, and the roof plate 4 is lightly pressed from above.

In this case, the conventional case, especially the roof plate 4, covers the entire surface and the volume is extremely low, making it impractical. In other words, in the case of cantilever beam vibration, the roof plate 4 acts as a soundboard and the sound volume increases, but the free-vibrating sound piece 1 at both ends
This is because there is no such soundboard driving force.

If the roof plate 4 is removed, the sound will be produced, but the sound will be uneven depending on the range. As is well known, the vibration mode of the vibrating bar 1 with both ends freely vibrating uses the first mode in which when the portion s between the two support points of the vibrating bar 1 is displaced upward, the portions at both ends other than s are displaced downward. As a result,
There is a 180° phase shift between the sound coming from the s part and the sound coming from both end parts other than the s part. For this reason, if the portion of the roof plate 4 corresponding to the s portion is removed, the sound volume will increase more than if the front surface of the roof plate 4 is removed.

(Means for Solving the Problems) The toy piano according to the present invention has a plurality of sound pieces 1 supported in the vicinity of two points, which are nodes of a free vibrating body at both ends, arranged in parallel corresponding to keys 2, and when the keys 2 are pressed. In a toy piano in which the tone bar 1 is struck with a hammer 3 to emit a scale tone of a predetermined frequency, the tone bar 1 has an elastic upper surface at two supported points separated by a support distance s. The underside of the sound bar 1 is also bonded with an elastic material and is bonded to a support member 8, and at least one of the support members 8 is bonded to the support member 8. The sound volume can be increased by joining the side plate 9 or the front plate 12, or by providing a new partition plate 14 on the support base member 8 and the bottom plate 10, and shielding the vibration sound other than the support interval s of the sound bar 1. It is characterized by:

(Example) Examples will be explained below.

The purpose of the present invention is to improve the overall volume balance by increasing the volume, especially as a countermeasure for low-volume bass parts. Examples of the present invention are shown in FIGS. 2, 3, and 4. In Figure 2,
A sound emitting hole 4a is provided within the two-point support space s, and
The front and rear support members 8 are extended to the front plate 12 and the rear plate 9, respectively, and the roof plate 4 and the support member 8 reduce vibration noise within the two-point support section s and both ends of the portion other than s. It has a shielding structure 14 to prevent it from being mixed with the sound of vibrations. Here, the supporting elastic members 11 and 5 that support the vibrating bar 1 are preferably made of closed-cell foamed urethane, foamed synthetic rubber, or the like.

The support base member 8 in FIG. 2 may be used to completely shield the bass to treble range, or it is also possible to partially shield only the bass range.

Next, in FIG. 3, the supporting base member 8 is used as a width plate having a desired length, and a shielding plate 14 is separately disposed between the support member 8 and the bottom plate 10 from its lower surface (or side surface). In this case, the shielding plate 14 is not attached to one free end side because there is a sink rail 6, a keyboard 2, etc., but it can be combined with the method shown in Figure 2 or omitted as shown in Figure 3. .

Figure 4 shows the case of a toy piano with a roof plate 4 that can be opened and closed.In this case, a partition plate 13 is provided as a substitute for the roof plate 4 in Figure 3, and the area s is made into a sound emitting hole. , or multiple sound emitting holes shall be provided in a separate application.

With the above structure, sounds at 180 degrees different positions do not mix with each other, so the volume increases. According to experiments, even with the simplest structure shown in Figure 3, the volume increased considerably.

(Effects) As described above, according to the present invention, it is possible to fully bring out the advantageous characteristics of the two-point supported sound piece, and the volume is comparable to that of the cantilever sound piece. , it is possible to provide a wonderful toy piano with excellent tone.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing the internal structure of a toy piano with two-point support type sound pieces as sounding bodies; Figure 2;
3 and 4 are sectional views showing each embodiment of the toy piano of the present invention. 1...Sound piece, 2...Key, 3...Hammer, 4...
...Roof plate, 4a... Sound emitting hole, 8... Support member, 10... Bottom plate, 14... Shielding plate.

Claims (1)

[Scope of utility model registration request] A plurality of vibrating bars 1 supported in the vicinity of two points serving as nodes of a free vibrating body at both ends are arranged in parallel corresponding to keys 2, and when the keys 2 are pressed, the vibrating bars 1 are struck with a hammer 3. In a toy piano that emits a scale tone of a predetermined frequency, the tone bar 1 has its upper surface bonded with an elastic material at two supporting points separated by a support gap s, and is in contact with the roof plate 4. The lower surface of the support base member 8 is also bonded with an elastic material and is adhered to a support base member 8, and at least one of the support base members 8 is joined to the side plate 9 or the front plate 12, or the support base member 8 and the bottom plate 10 are connected to each other. A toy piano characterized in that a partition plate 14 is provided between them to block vibration sounds other than the support interval s of the sound piece 1, thereby increasing the sound volume.