JP2582780Y2 - Musical instrument case - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION This invention relates to a musical instrument case.

[0002]

2. Description of the Related Art Conventionally, in an electronic keyboard musical instrument, a metal keyboard chassis is assembled in a synthetic resin musical instrument case, and a number of keys are arranged in parallel on the keyboard chassis to secure the rigidity of the entire musical instrument. , To prevent warping of the instrument case. However, the structure using the keyboard chassis has the disadvantages that not only the number of parts is increased, the assembling work becomes complicated, but also the weight of the entire musical instrument becomes heavy. In recent years, instead of using a metal keyboard chassis, a synthetic resin keyboard chassis has been formed integrally with the instrument case, and a reinforcing thick-walled portion has been formed on the keyboard chassis to provide an overall instrument. It has been studied to secure the rigidity.

[0003]

However, in such a musical instrument case, if a thickened portion for reinforcement is simply formed in a keyboard chassis made of synthetic resin, the surface of the thickened portion is contracted due to shrinkage of the resin during injection molding. There is a problem in that sink marks are generated, and the sink marks cause warpage of the musical instrument case. In such a warped musical instrument case, the interval between adjacent keys and the height of the keys become irregular, and the key pressing timing of the initial touch switch at the time of key pressing becomes irregular, so that the key pressing speed cannot be detected, Quality cannot be guaranteed. In particular, in a large musical instrument case in which keys are arranged, for example, in a number of 61 or more, the above-described problem becomes conspicuous. The present invention has been made in view of the above circumstances, and an object of the invention is to provide a musical instrument case that prevents a sink from occurring on the surface of a thick portion during injection molding, has no warpage, and has high rigidity.

[0004]

According to the present invention, in order to achieve the above-mentioned object, a thickening portion having a hollow portion is formed at a predetermined position of a synthetic resin musical instrument case.

[0005]

According to this invention, it is possible to prevent the occurrence of sink marks on the surface of the thick portion due to shrinkage of the resin during the injection molding by the hollow portion, thereby preventing the occurrence of warpage and the rigidity. You can get something high.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is an external plan view of an electronic keyboard instrument. This electronic keyboard instrument is an instrument case 1 made of synthetic resin.
It has. The musical instrument case 1 includes a main body case 2 and a cover case 3, and a large number of keys (white keys and black keys) 4 are arranged in parallel at the front of the main body case 2.
A cover case 3 is attached to the rear of the key 4 so as to cover the rear end of each key 4. In this case, a speaker sound emitting section 5 is provided on both sides of the cover case 3, and a display section 6 is provided in the center thereof, and various switches 7 for power supply, automatic performance, tone setting, and the like are provided therebetween. Have been.

FIG. 2 is a plan view of the main body case 2, and FIG.
It is AA sectional drawing of. As shown in these figures, the main body case 2 includes a keyboard chassis 1 in which keys 4 are arranged in parallel.
0 and a component storage section 11 for storing electronic components such as a speaker and a power supply (not shown). These components are integrally formed of a thermoplastic resin such as polystyrene (PS). In this case, the component storage portion 11 is formed in an elongated concave shape, and a flange portion 12 is provided on an outer periphery thereof, and a plurality of cylindrical portions 13 are provided at a position close to the keyboard chassis portion 10. A screw insertion hole 14 for inserting a screw (not shown) for attaching the cover case 3 to the upper end portion of the shaped portion 13 and the flange portion 12 is provided.

On the other hand, the keyboard chassis 10 has a structure in which a rear arrangement portion 21 in the middle of the main body case 2 is higher than a front arrangement portion 20 on the left side in FIG. 3, and an intermediate arrangement portion 22 is provided therebetween. I have. The rear array portion 21 is formed so as to gradually increase in height from the front to the rear. The rear end of the rear side array portion 21 has an intermediate leg 2
3 is provided, a key attaching portion 24 to which the key 4 is attached is provided at the uppermost portion of the rear end portion, and two rubber switches (not shown) for obtaining initial touch data are provided at the lowermost portion of the front end portion. Two through holes 25 to be inserted are provided. In this case, the key 4 is, as shown by a two-dot chain line in FIG.
A connecting portion 4b is provided at the rear end via a bent portion 4a, and the adjacent keys 4 are connected by the connecting portion 4b. The connecting portion 4b is positioned by the positioning portion 18 provided on the key attaching portion 24. The key 19 is attached to the key attaching portion 24 by a screw 19, so that the key attaching portion 24 is vertically rotated about the bent portion 4a. The intermediate array unit 22
A groove portion 26 having a V-shaped cross section is provided continuously to the rear array portion 21, and a falling portion 27 having an inverted L-shaped cross section that is continuous with the groove portion 26 is provided. This falling part 27
The stapling hole 28 is provided in which the tip of an L-shaped stopper 4c provided on the key 4 is inserted movably in the vertical direction to regulate the initial position (upper limit position) and the lower limit position of the key 4. I have. A key guide 29 is provided on the falling portion 27 to prevent the key 4 from swaying left and right and to guide the key 4 up and down. The front array section 20 has a structure in which a front leg 30 is provided to intersect with a front end of the falling portion 27 and an inclined portion 31 is provided which is gently inclined from an upper portion of the front leg 30 toward the front end. It has become.

Also, as shown in FIG. 2 and FIG. 3, a predetermined portion of the main body case 2, a rear bottom portion of the component storage portion 11, a front and rear portion of the key attachment portion 24 of the keyboard chassis portion 10, and a V-shaped cross section. At the bottom of the groove 26, at the intersection of the front end of the falling part 27 and the front leg 30, and at the front end of the slope 31,
Thick portions 32 for reinforcement are formed along the direction in which the keys 4 are arranged. As shown in FIG. 3, cavities 33 are formed in the thick portions 32 along the direction in which the keys 4 are arranged. As shown in FIGS. 2 and 3, the rear array portion 21 of the keyboard chassis portion 10 has a reinforcing portion extending from the thick portion 32 at the rear of the key attachment portion 24 to the front end of the rear array portion 21. A large number of ribs 34 are provided at appropriate intervals in the arrangement direction of the keys 4. In these ribs 34,
Similarly to the thick portion 32, a cavity (not shown) is formed.

The thick portion 32 and the hollow portion 33 provided at predetermined positions of the main body case 2 are formed to have substantially the same size. Here, the thick portion 32 at the intersection of the front end of the falling portion 27 and the front leg 30 will be described with reference to FIG. The thickness M of the main body case 2 is such that the length M of the portion formed on the surface of the front end of the falling portion 27 and the length N of the portion formed on the surface of the front leg 30 are equal to the thickness t of the main body case 2. Are formed in a size of approximately 3 to 5.5 times. In this case, although the outer surface of the thick portion 32 is formed on the inclined surface 32, it is not necessarily formed on the inclined surface 32a, and the cross section may be rectangular. The inner diameter R of the hollow portion 33 formed in the thick portion 32 is such that the thickness of the thick portion 32 around the hollow portion 33 is, for example, substantially the same as the thickness t of the main body case 2. The diameter may be smaller than this. The cavity 33 is formed by press-fitting a gas such as air from the outside during injection molding until the resin is solidified.

In such a musical instrument case 1, a plurality of rows (six rows in this embodiment) of thick portions 32 are provided at predetermined positions of the main body case 2 along the direction in which the keys 4 are arranged. 3
Since the hollow portion 33 is formed along the longitudinal direction in the main body 2, it is possible to prevent the sink from occurring on the surface of the thick portion 32 due to the contraction of the resin when the main body case 2 is injection-molded. Accordingly, it is possible to prevent the main body case 2 from being warped, and to obtain a highly rigid body. As a result, the interval between adjacent keys and the key height can be made uniform, and a high-quality keyboard instrument can be obtained. In particular, in the musical instrument case 1, a plurality of rows (five rows in this embodiment) of thick portions 32 are provided in the keyboard chassis section 10 of the main body case 2 to which an external force is applied at the time of a key pressing operation in the arrangement direction of the keys 4. Rib 3 on the array 21
Since a large number of the keys 4 are provided at appropriate intervals in the direction in which the keys 4 are arranged, even a large one in which, for example, 61 or more keys 4 are arranged, sufficient rigidity can be ensured without using a reinforcing bracket or the like. . For this reason, the musical instrument case 1 does not bend due to the key pressing force at the time of key pressing, and it is possible to perform well.

In the above embodiment, a case where the present invention is applied to a keyboard instrument has been described. However, the present invention is not limited to this and can be applied to an instrument case such as a guitar.

[0013]

As described above, according to the present invention, a thickening portion having a hollow portion is formed at a predetermined portion of a musical instrument case made of synthetic resin. The generation of sink marks on the surface of the thick portion can be prevented by the hollow portion, whereby the occurrence of warpage can be prevented and a highly rigid musical instrument case can be obtained.

[Brief description of the drawings]

FIG. 1 is an external plan view of a keyboard instrument of the present invention.

FIG. 2 is a plan view showing the main body case of FIG. 1;

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is an enlarged perspective view of a main part of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Musical instrument case 2 Main body case 10 Keyboard chassis part 32 Thick part 33 Hollow part

Claims (2)

(57) [Scope of request for utility model registration] 1. The case and keyboard chassis are integrated with synthetic resin
The case and the keyboard chassis each have at least one
At the same time, a thick portion for reinforcement is formed and
A musical instrument case characterized in that a hollow portion is formed in the musical instrument case. 2. The keyboard chassis has a plurality of keys arranged therein.
A key attachment portion for attaching the key attachment portion in the key arrangement direction
The musical instrument case according to claim 1, further comprising a thick portion formed with a plurality of rows of hollow portions along the line .