JPH0721707B2 - Electronic musical instrument keyboard device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a keyboard device for an electronic musical instrument, which improves a touch feeling that enables stable and reliable key operation and also improves durability.

[Conventional technology and problems]

Conventionally, a keyboard device in an electronic keyboard musical instrument such as an electronic organ has a plurality of keys integrally formed of synthetic resin,
A key support member, which is manufactured by press working and has the plurality of keys arranged on the upper surface so as to be swingable in the vertical direction, and is interposed between each key and the key support member to give the key a habit of returning. It is provided with a resilient elastic body such as a spring.

By the way, as a fulcrum structure of a key, it has been conventionally shown in FIGS.
What is shown in the figure is generally adopted. That is, FIG. 1 shows a structure in which the key 3 is supported by the upper end portion of the fulcrum plate 2 fixed to the rear end surface of the key support member 1.
A substantially trapezoidal engagement recess 4 into which the upper end of the fulcrum plate 2 engages is provided on the lower surface of the rear end of the key 3, and the return spring 5 moves the front end of the key 3 upward, that is, in the clockwise direction. The habit is given to the key 3.

In the fulcrum structure of the key plate device, however, since the engaging recess 4 is supported on the upper end of the fulcrum plate 2 only by the force of the return spring 5, the force at the time of key pressing is the center of the key 3 in the left-right direction. When acting on a position deviated from the line, a force for tilting the key 3 in the left-right direction is generated in addition to the force for rotating the key 3 downward. If this force is stronger than the spring force, the key 3 is easily tilted, There was a drawback that it made the touch feeling worse and generated noise at the same time.

In FIG. 2, a fulcrum plate 2 is integrally provided on the rear end of the key support member 1 by bending, and an insertion hole 6 punched in the fulcrum plate 2 is integrally projected on the rear end surface of the key 3. The protrusion 7 is inserted, and the engaging recess 4 provided on the upper surface of the protrusion 7 is inserted into the insertion hole 6 by the force of the return spring 5 composed of a compression coil spring.
It is adapted to be engaged with the upper edge 6a. But,
Such a fulcrum structure has basically the same drawback as the fulcrum structure shown in FIG. 1 because it is basically the same.

FIG. 3 is intended to solve the drawbacks due to the fulcrum structure shown in FIGS. 1 and 2, in which an insertion hole 6 is provided on the surface of the key supporting member 1 and is integrated with the lower surface of the rear end portion of the key 3. The mounting foot 8 provided is inserted into the insertion hole 6 and the engagement recess 4 is pressed against the rear end edge 6b of the insertion hole 6 by the force of the return spring 5. According to such a fulcrum structure, the key 3 is given a habit of returning in the clockwise direction by the return spring 5 and is urged rearward at the same time.
The upper and lower inclined walls 4a, 4b and the rear end edge 6b of the insertion hole 6 can be almost completely regulated, and therefore, the third backlash and the noise can be reduced and a good key operation can be obtained. Therefore,
It can be said that this fulcrum structure is superior to the fulcrum structures shown in FIGS. 1 and 2, but there is a problem in terms of durability of the pivot fulcrum part, because the fulcrum structures are the same or different.

That is, since the key supporting member 1 is usually formed of a metal plate and the insertion hole 6 is punched by press working, the end of the insertion hole 6 as shown in FIGS. 4 (a) and 4 (b). Sagging 9 and burrs 10 are inevitably generated over the entire circumference. It should be noted that FIG. 9A shows the case where the insertion hole 6 is punched from the front surface side of the keyboard frame 1, and FIG. Here, especially among Bali 9 and Bali 10, Bali 10
Is projected on the front surface or the back surface side of the keyboard frame 1, so that when the engagement concave portion 4 comes into contact with the rear end edge 6b of the insertion hole 6, the burr 10 will be the root portion 11a or 11b of the inclined wall 4a or 4b. Abut. Therefore, the key 3
When is rotated, the burr 10 bites into the lower root portion 11b, which is the rotation center of the key 3 in the configuration of FIG. 7A, and the upper root portion 11a of the configuration of FIG. Rub against the burr 10 and use these roots 11a, 11 during long-term use.
b is gradually scraped off. This shaving phenomenon becomes more remarkable as the key pressing operation is performed more strongly, so that the sliding phenomenon of the key 3 is more likely to occur, and the bottom width W of the engaging recess 4 is increased. This increase in the bottom width W causes rattling of the key 3 in the vertical direction, and this rattling promotes scraping by the burr 10. Therefore, good key operation will not be obtained, noise will be generated, and if scraped off particles fall and adhere to the key switch, contact failure will occur and sound will not be produced, resulting in performance and reliability of the instrument itself. Adversely affect.

In addition, the support structure shown in FIGS. 5 and 6 is also adopted. That is, FIG. 5 should be called an improvement of the fulcrum structure shown in FIG. 1, in which the elastic body 15 made of rubber or the like formed in a substantially U shape is fitted and fixed to the upper end of the fulcrum plate 2. is there. In such a fulcrum structure, there is no direct rubbing between the fulcrum plate 2 and the key 3, and since there is no dimensional clearance due to the deformation of the elastic body 15, it is possible to prevent rattling and noise. Have advantages. However, rubbing exists between the fulcrum plate 2 and the elastic body 15 and between the key 3 and the elastic body 15. If the elastic body 15 is completely elastically deformed in response to the rotation of the key 3, it seems that there is no rubbing on the body, but in reality, rubbing in a minute portion always exists. Since the elastic body 15 actively tries to elastically deform, a flexible substance is used, but generally such a substance has low abrasion resistance due to rubbing, and therefore the above-mentioned minute amount is used. It is easy to wear even if it rubs. Further, in the portion where the key support member 1 and the elastic body 15 rub, a crack or the like is likely to occur due to a burr of the key support member 1 and the durability is poor.

On the other hand, regarding the touch feeling, since the rubbing occurs only minutely, it can be said that there is relatively little variation in the touch due to the non-uniform rubbing as in the fulcrum structure shown in FIG. 1 and status slip. However, on the other hand, since the elastic body 15 is elastically deformed according to the rotation of the key 3,
The elastic pressure acts on the touch pressure. In other words, it exhibits a property similar to the sharp increase in the touch pressure due to the above-mentioned bite phenomenon of burr. Moreover, there is no problem if the phenomenon occurs uniformly for each key, but in reality, it is difficult for elastic deformation to uniformly occur due to the slight rubbing. In other words, it is very difficult for a stable touch for each key, and the touch feeling tends to vary.

Next, FIG. 6 shows that the rear end of the key 3 is rotatably supported by a horizontal shaft 16 so that rubbing can be performed more positively. In this case, the rubbing between the key 3 and the shaft 16 is different from the rubbing in any of the fulcrum structures described above, and does not cause a defect, but on the contrary, complements the defect. This is because the cross-sectional shape of the shaft 16 and the hole 17 through which the shaft 16 is inserted is circular,
This is because the key 3 can be smoothly rotated about the shaft 16. In this case, the closer the shaft 16 and the hole 17 are to a perfect circle, the smoother the contact with each other and the better sliding characteristics can be obtained.

Here, in the fulcrum structure shown in FIGS. 1 to 3 and 5, it is conceivable to provide an arcuate sliding contact surface, but such a sliding contact surface is extremely difficult in machining, and It can be said that it is possible. That is, since the key supporting member 1 is pressed, the sagging 9 and the burr 10 shown in FIG. 4 are inevitably formed at the edge of the insertion hole 6 (see FIGS. 2 and 3), and temporarily press the Even if the clearance between the punch and die of the die is adjusted so that the sagging is semicircular, it is difficult to say that it is a part of a perfect circle.

On the other hand, the shaft 16 described above is technically close to a perfect circle because it is cut. Further shaft 16 and hole
If the precision of 17 is increased and a so-called abutting surface is used, the contact area can be secured over the entire circumference of the shaft 16, so that the friction characteristics can be improved.

As described above, the fulcrum structure shown in FIG. 6 can obtain a stable and smooth key operation as compared with the fulcrum structure shown in FIGS. 1 to 3 and 5, but on the other hand, the assembly and the disassembly are not possible. It has a major drawback that the work is troublesome.
That is, the key 3 cannot be removed unless the shaft 16 is removed from the key 3 and the bracket 18. In addition, since the keys are generally arranged in close proximity to each other, the all-key uniaxial system is usually adopted. Therefore, even if one wants to remove one key 3, it cannot be removed unless the shaft is removed from all keys, and all keys are scattered. Also, when taking in, if all the keys are not aligned in reverse, the shaft will not pass and it will be extremely difficult to assemble.

In addition, since all the keys are uniaxial, it is difficult to give the locking function to the axis when moving the keys in the lateral direction, and the lateral movement of the keys is caused by the side surface of the stand cut and raised in the key plate frame 1. Must be regulated. In that case, friction during rotation of the key occurs not only on the key 3 and the shaft 16 but also on the inner surface of the key 3 and the stand, so that it becomes necessary to consider the frictional characteristics at that portion. Therefore, it has been considered to interpose a washer having a good friction characteristic between the key 3 and the stand. However, this causes an increase in the number of parts, which causes a cost increase and further deteriorates the assembling workability. .

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to obtain a stable and reliable key touch feeling and also to change the rotational fulcrum portion with time. An object of the present invention is to provide a keyboard device for an electronic musical instrument that is few and has excellent durability.

[Means for Solving the Problems]

In order to achieve the above object, the present invention comprises a key rotatably arranged on a key support member, and a return elastic body for giving a habit of returning the key to a non-operating state. A rotation fulcrum part having a predetermined width wider than the width of the side wall of the key in the width direction of the key, and having a cross section parallel to a surface perpendicular to the width direction within the predetermined width, each having a circular arc portion; And a rotation fulcrum contact portion having an arc portion having the same radius of curvature as the arc portion of the rotation fulcrum portion slidably abutting the arc portion of the rotation fulcrum portion behind the playing portion of the key. And the rotation fulcrum portion and the rotation fulcrum contact portion are in contact with each other along the circumferential direction of the circumferential surface on which the rotation fulcrum portion and the rotation fulcrum contact portion contact. An annular projection is provided on the circumferential surface over the entire length in the circumferential direction, and a fitting groove corresponding to the projection is provided on the other circumferential surface. Provided, in which each is fitted freely relative sliding.

[Action]

In the present invention, the arc-shaped rotation fulcrum portion and the rotation fulcrum abutment portion have a large contact area when the key is rotated, a good touch feeling is obtained, and variations in the surface are averaged, so that all keys are An almost constant touch feeling is obtained. In addition, there is little secular change in the contact surface, and it is easy to align the key due to the fitting of the protrusions and the fitting groove over the entire length of the circumferential surface. It is more advantageous in terms of feeling and averaging the surface roughness as compared with the case where there is no groove.

〔Example〕

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 7 is a perspective view of the essential parts showing the first embodiment of the keyboard device according to the present invention. This embodiment shows an example in which the all-keys single-axis system is adopted. In the figure, 21 is a coaxial fulcrum member 21, and this rotation fulcrum member 21 is made of synthetic resin and is viewed from the side. Is formed in a shape and is arranged in the width direction of the key supporting member 1 so as to have a length that extends in common to all keys 3, and a set screw is provided on the upper surface of the rear end portion of the key supporting member 1. Legs 22 fixed by means of the like (not shown), and a rotation fulcrum 23 extending forward.
It consists of and. The rotation fulcrums 23 are located above the key supporting member 1 and are spaced apart from each other, and the front surface thereof is formed in an arc shape to form a sliding surface 24 of the key 3. Also, this arcuate sliding surface 24
An annular projecting body (projecting body) 25 is integrally provided so as to correspond to each key 3 over the entire length of the sliding surface in the circumferential direction.

The rear end surface 26 of the key 3 has an arcuate sliding surface of the rotation fulcrum 23.
A rotation fulcrum contact portion 27, which is a concave portion formed in a semi-circular shape with the same radius as the curvature radius of 24, is formed over the entire length of the key 3 in the width direction. Further, a fitting groove 28 into which the projection 25 can be slidably fitted is formed at the center of the rotation fulcrum contact portion 27 in the circumferential surface width direction. Then, the key 3 is given a habit of returning upward by an unillustrated returning elastic body and is urged backward at the same time, so that the rotation fulcrum contact portion 27 of the rotation fulcrum portion 23 is moved. The projection 25 and the fitting groove 28 are fitted to each other by being pressed against the arcuate sliding surface 24.

In such a configuration, when the front end portion of the key 3 is pressed, the key 3 pivots and descends against the return elastic body. At this time, the rotation fulcrum contact portion 27 is formed on the arcuate sliding surface 24 of the rotation fulcrum portion 23.
Sliding down along.

Here, since the rotation fulcrum contact portion 27 is formed over the entire width of the key 3 and the contact area of the rotation fulcrum portion 23 with the arcuate sliding surface 24 is large, stable and reliable key operation is possible. Is what you get.

That is, when the key is pushed, the contact surfaces of both the key and the pivot fulcrum member slide, but the fulcrum structure of the above-mentioned conventional system (particularly FIGS. 1, 2, 3, and 5) As described above, if the contact area is small, the roughness of the surface due to aging or the like, that is, if the variation is large, the resistance changes due to it during the pushing, and the change in the key touch feeling is felt. Moreover, there is a possibility that a plurality of keys may have different touch feelings.

On the other hand, when the contact area is increased as in the present invention, the contact surface itself moves and changes during the movement of the key, but surface variations are averaged due to the large sliding surface area, and the key touch feeling due to the variation is Since the influence on the key is reduced, a smooth key depression operation is possible. Also, the contact surface (sliding surface)
The change over time can be suppressed, and a good key touch feeling can be obtained over many years. Furthermore, since the plurality of keys 3 are supported by the rotation fulcrum member 21, there is no fear that the key touch feeling will be different for each key.

In addition, the projection 25 and the fitting groove 28 further increase the contact area and position the key 3 in the left-right direction to prevent rattling.

FIG. 8 is a perspective view of an essential part showing a second embodiment of the present invention. In this embodiment, the key support member 1 and the pivot fulcrum member 21 are integrally formed by outsert molding, and a plurality of fitting grooves 30 are formed on the arcuate sliding surface 24 of the pivot fulcrum member 21. A protrusion 31 is formed corresponding to the key 3 and is integrally provided at the rotation fulcrum contact portion 27 of each key 3 so as to be slidably fitted in the fitting groove 30.

The rotation fulcrum member 21 integrally has a frame portion 32 that fits into an insertion hole (not shown) provided in the key support member 1 and replaces the leg portion 22 shown in FIG. .

The other structure is similar to that of the first embodiment described above.

Even with such a configuration, the same effect as that of the above embodiment can be obtained.

FIG. 9 is a perspective view of a key support member and a rotation fulcrum member showing a third embodiment of the present invention. This embodiment shows a 1-key 1-axis system. The rotation fulcrum member 21 is formed into a columnar shape in a side view by an upper semicircular portion 21A having a predetermined width wider than the key width and a lower semicircular portion 21B having the same radius and a sufficiently small width. A groove 40 that opens rearward is provided between the semicircular portions 21A and 21B. Further, on the peripheral surfaces of the upper and lower semicircular portions 21A, 21B, a series of projecting bodies 25 for positioning the key in the left-right direction are provided in a protruding manner. The rotation fulcrum member 21 is detachably attached to the key support member 1 by engaging the groove 40 with the rear end edge 6b of the insertion hole 6 formed in the key support member 1.

The structure of the key is similar to that of the first embodiment shown in FIG.

FIGS. 10 (a) and 10 (b) are a side sectional view of an essential part showing the fourth embodiment of the present invention and a view for explaining the effect. This embodiment shows a modification of the third embodiment shown in FIG. 9 and is different only in that the lower half portion of the lower semicircular portion 21B is removed. Therefore, the side surface shape of the rotation fulcrum member 21 is an arc shape extending over a range of approximately 270 °. On the other hand, the rotation fulcrum contact portion 27 of the key 3 is formed in an arc shape of about 200 °.

Here, the reason why the rotation fulcrum member 21 is formed in a substantially 3/4 circular shape is that the rotation fulcrum contact portion 27 can be easily separated from each other even when the rotation fulcrum contact portion 27 is 180 ° or more. Is. That is, as shown in FIG.
When the notch portion 41 of the rotation fulcrum member 21 is turned directly downward (or right above) by rotating the rotation fulcrum member about 45 ° clockwise, even if the rotation fulcrum contact portion 27 extends 180 ° or more. Regardless, it is possible to eliminate the interference portion due to the dimensional difference between d ₁ and d ₂ , so when the rotation fulcrum member 21 is pulled in the direction of the arrow 42, it can be easily pulled out from the rotation fulcrum contact portion 27. When it is taken in reverse, it can be inserted from the direction opposite to the direction of the arrow 42.

In this case, the rotation fulcrum member 21 is assembled to the rotation fulcrum contact portion 27 of the key 3 and then fitted and fixed in the insertion hole 6 of the key support member 1 as in the third embodiment. is there.

FIG. 11 is a side sectional view of the essential parts showing a fifth embodiment of the present invention. This embodiment shows a modification of the above-mentioned fourth embodiment, and a retaining piece 45 attached to the back surface of the key support member 1 is used.
The pivotal fulcrum member by projecting the upper end of the key above the key support member 1.
The concave portion 48 provided on the lower surface 47 of the extension portion 46 that extends toward the rear of 21 is inserted and engaged from below to prevent the rotation fulcrum member 21 from falling off the insertion hole 6. It is a thing. Although the retaining piece 45 is arranged on the cut-and-raised piece 50 formed by cutting and raising the back surface of the key supporting member 1, it may be fixed to the back surface of the key supporting member 1 by a screw or the like. .

The other structure is substantially the same as that of the fourth embodiment shown in FIG.

In addition, in all of the third to fifth embodiments, the rotation fulcrum member 21 of the one-key / one-axis system is shown. Of course, it can be used as a system.

〔The invention's effect〕

As described above, in the keyboard device for an electronic musical instrument according to the present invention, the swing fulcrum portion having a predetermined width wider than the side wall width of the key and the arc portion, and the key playing portion corresponding to the swing fulcrum portion. A rotation fulcrum contact portion having an arcuate portion having the same curvature as the arcuate portion of the rotation fulcrum portion provided further rearward, and the rotation fulcrum portion and the circumferential surface with which the rotation fulcrum abutment portion abuts Along the circumferential direction of the rotation fulcrum portion and the rotation fulcrum abutment portion on one of the circumferential surface is provided with an annular projection extending the entire circumferential direction, the other circumferential surface. Since the fitting grooves corresponding to the protrusions are provided so that the fitting grooves are slidably engaged with each other, the contact area between the rotation fulcrum portion and the rotation fulcrum contact portion is large, and the key is stable and reliable. Motion is obtained,
Improves the key touch feeling. Also, there is little secular change in the contact surface, stable performance is maintained over a long period of time, and the projection and the fitting structure simultaneously position the key in the left-right direction to prevent rattling in the left-right direction. it can.

[Brief description of drawings]

1 to 3 are a side view, a cross-sectional view and a side view of essential parts showing a fulcrum structure in a conventional keyboard device, and FIGS. 4 (a) and 4 (b) are views for explaining the influence of burrs,
FIGS. 5 and 6 are side views of essential parts showing a fulcrum structure in a conventional keyboard device, FIG. 7 is a perspective view showing a first embodiment of the keyboard device according to the present invention, and FIG. FIG. 9 is a perspective view showing a keyboard device according to a second embodiment of the present invention, and FIG. 9 is a perspective view of a key support member and a rotation fulcrum member showing a keyboard device according to a third embodiment of the present invention. b) is a side sectional view showing a fourth embodiment of a keyboard device according to the present invention and a view for explaining the effect, and FIG. 11 is a side sectional view showing a fifth embodiment of the keyboard device according to the present invention. . 1 ... Key support member, 3 ... Key, 21 ... Rotation fulcrum member, 22 ... Leg part, 23 ... Rotation fulcrum part, 24 ... Arc-shaped sliding surface, 25 ... Projected body, 27 …… Rotation fulcrum contact part, 28 …… Mating groove, 30 …… Mating groove, 31 …… Projecting body.

Claims (1)

[Claims] 1. A key rotatably mounted on a key support member, and a return elastic body for imparting a habit of returning the key to a non-operating state. A rotation fulcrum section having a predetermined width wider than the width of the side wall of the key, and having a cross section parallel to a plane perpendicular to the width direction having an arc portion within the predetermined width; A rotation fulcrum contact portion having an arc portion having the same radius of curvature as the arc portion of the rotation fulcrum that abuts in a swingable manner with the predetermined width. Section and the rotation fulcrum abutment portion are in contact with each other along the circumferential direction of the circumferential surface on the circumferential surface of one of the rotation fulcrum portion and the rotation fulcrum abutment portion in the circumferential direction. A ring-shaped projection is provided, and a fitting groove corresponding to the projection is provided on the other circumferential surface. A keyboard device for an electronic musical instrument, characterized in that it is fitted in place.