JP3912415B2 - Spring mechanism - Google Patents

Description

  The present invention relates to a spring mechanism that uses the repulsive force of a spring, and more particularly, to a spring mechanism that can be attached even when the place to be attached is limited in space.

  As a spring mechanism using the repulsive force of a spring, for example, a mechanism using a coil spring or a straight leaf spring has been often used.

  However, the former one of the conventional spring mechanisms, that is, the one using a coil spring, is difficult to accurately generate the repulsive force intended by the designer, and the deformation progresses as the period of use becomes longer. It was difficult to stabilize the operating axis of the spring during use.

  The latter of the above conventional spring mechanisms, that is, those using a straight leaf spring, are so large that the mounting position must be taken into account when the characteristics intended by the designer are provided. In particular, when there is a space limitation in the place to be installed, it could not be easily installed.

  The present invention has been made paying attention to this point, and it is an object of the present invention to provide a spring mechanism that can be attached to a place where space is limited while having the characteristics intended by the designer.

In order to achieve the above object, the spring mechanism according to claim 1 is a spring mechanism having a V-shaped leaf spring formed by bending a planar leaf spring and comprising both blade leaf springs. A first support part for fixing the V-shaped leaf spring to the keyboard frame is provided on a part of the outer surface of one of the blade springs of the blade springs. A second support portion for supporting the rear portion of the key is provided on a part of the outer surface of the other wing plate spring, and is formed by operating the key supported by the second support portion. An imaginary rotation center that is an intersection of a tangent that is in contact with a part of the outer surface of the other blade blade spring at the beginning of the bending section and a tangent that is in contact with a part of the outer surface at the end of the bending section is A position bent in a V shape from the position where the rear part of the key is attached on the outer surface of the other wing leaf spring So as to be positioned farther than the distance to the, by said key is operated, the key is characterized in that rotates about the virtual rotation center.

Preferably, a part of each outer surface of the blade blade springs is provided at a position closer to the opening than the bent portion of the V-shaped leaf spring.

According to the first aspect of the present invention, there is provided a spring mechanism having a V-shaped leaf spring formed by bending a planar leaf spring and formed of both blade leaf springs, one of the blade blade springs. A first support portion for fixing the V-shaped leaf spring to the keyboard frame is provided on a part of the outer surface of the blade blade spring of the other blade spring, and the other blade spring of the blade blade springs. A second support part for supporting the rear part of the key is provided on a part of the outer surface of the key, and at the initial stage of the bending section formed by operating the key supported by the second support part. A virtual rotation center that is an intersection of a tangent line that contacts a part of the outer surface of the other wing plate spring and a tangent line that contacts a part of the outer surface at the end of the bending section is the other wing plate spring. The distance from the position where the rear part of the key is attached to the position bent in a V shape So as to be location, by which the key is operated, since the key is rotated around the said virtual rotation center, while providing the intended properties of the designer, in places of space limitations It can be attached.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  1 to 3 are a plan view, a right side view, and a left side view, respectively, of a keyboard device for an electronic piano to which a spring mechanism according to a first embodiment of the present invention is applied. Hereinafter, the player side of the keyboard device is referred to as the front side, and the opposite side is referred to as the rear side.

  As shown in the figure, in the keyboard device of the present embodiment, the entire key is supported by the keyboard frame 100, and the keyboard frame 100 is supported by the shelf board 101. The key 40 is composed of a white key and a black key, and each key is rotated around the contact point with the support portion 41 by a support portion 41 extending in the front direction slightly behind the center of the keyboard frame 100. Is supported so as to be rotatable in the vertical direction. The mass body 50 is supported by the keyboard frame 100 below the key 40. The mass body 50 extends substantially horizontally in the front-rear direction as a whole, and the tip of the support piece 102 is formed by a support piece 102 erected on the front side of the keyboard frame 100 and a recess 51 for receiving the support piece 102. It rotates as a rotation center R50.

  In order to maintain the engagement state between the tip of the support piece 102 and the recess 51, one end of the S-shaped spring 42 presses the recess 52 provided on the back side of the recess 51 in the mass body 50. The recess 52 is formed of a rib having a constant width in the thickness direction of the mass body 50, and a thin plate portion extends vertically in the center of the recess 52 in the width direction of the rib. The end of the S-shaped spring 42 that engages with the recess 52 is bifurcated with a slit in the center, and the thin plate portion is inserted into the slit for engagement.

  The middle part of the S-shaped spring 42 is in contact with the edge of the spring through hole 103 at the center of the keyboard frame 100 in the front-rear direction. It is comprised so that the receiving part 43 may be pressed. As a result, the S-shaped spring 42 acts to press the mass body 50 against the distal end portion of the support piece 102 at the position of the recess 52 and to push down the rear portion of the mass body 50 from the rotation center R50.

  The front end portion of the mass body 50 is in contact with the lower end portion of the hanging piece 44 of the key 40, and is rotated in conjunction with the key when the key 40 is pressed. A switch board 60 is supported by the keyboard frame 100 near the lower part of the front end of the mass body 50, and a key switch 61 formed of dome-shaped rubber is fixed on the switch board 60. On the lower surface of the front portion of the mass body 50, a switch drive unit 53 having a pair of legs extending downward at a position corresponding to the key switch 61 is provided. The switch driving unit 53, the switch board 60, and the key switch 61 constitute a key pressing switch that senses the key pressing speed by using a conduction start time difference at the time of key pressing due to a difference between two contact distances in the key switch 61. ing.

  The mass body 50 extends to the rear portion of the keyboard frame 100 and is supported in the vicinity of the rear end portion by a felt stopper member 104 fixed on the keyboard frame 100 in the rest position (non-key-pressed state). When the key 40 is depressed, the mass body 50 moves from the rest position indicated by the solid line in FIGS. 2 and 3 to the key depression position indicated by the alternate long and short dash line. A stopper member 105 is held immediately behind the key 40 in the keyboard frame 100 and serves to stop the mass body 50 that has reached the key pressing position. The stopper member 105 covers the cushioning felt 105a with a protective sheet 105b, and the contact portion 54 at the rear end of the mass body 50 presses the buffering felt 105a through the protective sheet 105b. The cushioning felt 105a is usually configured by overlapping felts having different stiffnesses so as to provide a buffering action against a collision of the rear end portion of the mass body 50 and a reliable stop feeling with respect to the player's fingers. The mass body 50 is made of plastic from the front part to the vicinity of the rotation center R50, and is formed so that a metal bar extends from the rear part. The mass of the metal bar extending backwards causes inertia at the time of key depression. Causes resistance.

  A sensor device 70 is attached to the rear part of the keyboard frame 100. The sensor device 70 generally has a structure in which two tension members are supported at both ends of the keyboard. Of the two tension members, one tension member 71 is used for sensing, and is held between the cushioning felt 105a of the stopper member 105 and the protective sheet 105b and extends toward the front of the keyboard device. Yes. The other tension member 72 is a compensation member provided to prevent a decrease in sensitivity of the sensing tension member 71 due to a disturbance factor. The compensation tension member 72 extends in parallel with the sensing tension member 71 at a position slightly away from the stopper member 105 so as not to contact the mass body 50.

  A tension portion 70A supported by the keyboard frame 100 is provided outside the left end of the keyboard row. The tension portion 70 </ b> A includes a holding member 73 fixed to the keyboard frame 100 and a tension plate spring 74 attached to the holding member 73. The leaf spring 74 extends rearward from the holding member 73 and then is folded back to form a V shape. A small groove is formed at the free end of each leaf spring 74, and one end of each of the sensing tension member 71 and the compensation tension member 72. It supports to pull the part.

  A detection unit 80 supported by the keyboard frame 100 is provided outside the right end of the keyboard row. The detection unit 80 has a structure in which a detection leaf spring 82 extends from the detection circuit board 81. The detection leaf spring 82 is in the form of a leaf spring, the base end portion is fixed to the detection circuit board 81 with screws 88, 88, and the distal end portion is formed with a small groove so that the end portion of the sensing tension member 71 is formed. Supports to pull. A strain sensor 83 is attached near the base end of the detection leaf spring 82. In this example, the strain sensor 83 is configured using a piezo element. The detection circuit board 81 is provided with a circuit (not shown) for detecting an output signal from the strain sensor 83 and an adjustment element 84 for fine adjustment thereof. Further, the end of the compensation tension member 72 on the right side of the keyboard row is fixedly supported by the keyboard frame 100.

  In the sensor device 70, the following settings are further made. The tension plate spring 74 is stronger than the detection plate spring 82. Further, the tension member 72 for compensation has a higher tensile rigidity than the tension member 71 for sensing. That is, the compensation tension member 72 is fixedly supported at the right end by the keyboard frame 100 and pulled at the left end by the tension plate spring 74 to be in a predetermined extension state. On the other hand, the sensing tension member 71 is held at the left end position in FIG. 1 together with the compensation tension member 72 and the tension plate spring 74 as a joint holding portion. Further, the right end is held at the free end of the detection leaf spring 82 so as to bend the detection leaf spring 82. Therefore, in order to stabilize the position of the left end in a state where the compensation tension member 72 is pulled, the tension force of the tension leaf spring 74 is increased so that the detection leaf spring 82 is not greatly bent. The tensile rigidity of the tension member 72 is increased.

  As described above, the tension plate spring 74 is formed in a V shape. In this way, when the tensioning leaf spring 74 is formed in a V shape, the free end of the leaf spring 74 is virtually rotated around the center VR (see FIGS. 1 and 3). . That is, if the leaf spring 74 is formed in a flat shape and its free end is formed at the same position, it is equal to the fixed end formed at the position of the virtual center VR. That is, if the leaf spring 74 is formed in a flat shape, the size thereof is larger than that in the case where it is formed in a V shape. As a result, when there is a space limitation in the place where the leaf spring 74 is attached, the attachment is difficult and the attachment is not easy. In a linear leaf spring, its fixed end is fixed to one of two ends. However, in a V-shaped leaf spring, its fixed portion (holding portion) is not limited to an end. Since it may be formed in the intermediate portion, the degree of freedom of the attachment position is increased in this respect as well.

  Next, the operation of this keyboard apparatus will be described. 2 and 3 show a pause state before key depression. When the key is pressed from this state, the key 40 rotates downward about the rotation center R40, and the hanging piece 44 pushes down the mass body 50. Accordingly, the mass body 50 rotates about the rotation center R50, and the switch driving unit 53 moves downward toward the key switch 61. The switch driving unit 53 of the mass body 50 is in contact with the key switch 61, turns on the key pressing switch, and operates the sound generation mechanism to generate sound. During this time, the mass body 50 raises the rear part from the rotation center R50. Immediately after the switch drive unit 53 comes into contact with the key switch 61, the abutment portion 54 at the rear end of the mass body 50 abuts against the stopper member 105, whereby the rotation of the mass body 50 and the key 40 is stopped. .

  The sensor device 70 operates as follows. When the key pressing force is increased or decreased in the key pressing state, the contact portion 54 at the rear end portion of the mass body 50 changes the amount of bending of the stopper member 105, particularly the buffer felt 105a. The cushioning felt 105a of the stopper member 105 is held between the protective sheet 105b. Therefore, when the bending amount of the buffer felt 105a changes, the meandering amount of the sensing tension member 71 accompanying the bending also changes. When the amount of meandering increases, the distance between the ends of the sensing tension member 71 decreases, and accordingly, the bending of the detection leaf spring 82 increases. Therefore, the output of the strain sensor 83 increases. By picking up this output change, it is possible to detect a change in the pressing force applied to the key after the key is pressed. If the volume, sound quality, etc. are changed accordingly, after-touch control can be performed. By appropriately selecting the flexibility of the buffer felt 105a and the protective sheet 105b of the stopper member 105, even when a plurality of keys are pressed, the bending of the stopper member 105 due to each key pressing is stretched for sensing. Reflecting on the meandering of the member 71, accurate aftertouch control can be performed.

  However, the tension member 71 used in the sensor device 70 is long and straddles both sides of the keyboard row. Therefore, the change in length due to disturbance factors such as temperature and humidity after being attached to the keyboard device also becomes large. If the end of the tension member for sensing is fixed to the keyboard frame, the linear expansion coefficient of the tension member itself and the expansion coefficient of the keyboard frame itself disturb the distortion amount of the strain sensor due to disturbance factors. End up. Therefore, it is necessary to deal with these disturbance factors for accurate aftertouch control.

  The sensor device 70 of the present embodiment uses two tension members, and a sensing tension member 71 is provided in parallel to the compensation tension member 72. Then, the tension member 72 is stretched by applying the spring force of the tension plate spring 74 to the compensation tension member 72, and the sensing tension member 71 is the same as the compensation tension member 72 on the tension plate spring 74. The sensing tension member 71 itself receives the spring force of the detection leaf spring 82 in a state where one end is supported at this position. Therefore, even if a disturbance factor acts, the influence is absorbed by the compensating tension member 72, and the spreading to the sensing tension member 71 is prevented. That is, even if expansion heat is generated due to a rise in temperature after being attached to the keyboard device, the support point by the tension plate spring 74 is moved by the extension of the tension member. Since the thermal expansion amount is the same as that of the compensation tension member 72 and the sensing tension member 71, sensing is supported at one end at the position of the tension leaf spring 74 moved by the extension of the compensation tension member 72. The tension member 71 does not affect the other end of thermal expansion. This compensation action is similarly performed against the influence of humidity between the compensation tension member 72 and the sensing tension member 71 having the same elongation rate due to humidity. Depending on the external force at the time of attachment, the tension length of the tension member may change. On the other hand, the influence can be reduced by increasing the tensile rigidity of the compensating tension member 72.

  Further, the sensing tension member 71 has a portion corresponding to the key that is biased in a direction perpendicular to the tension direction (a direction in which a plurality of keys are arranged) by operating the key. Moves in the tensioning direction (due to tension). Since the amount of movement of the end portion, that is, the amount of bending of the detection leaf spring 82 is very small compared to the amount of deflection of the portion corresponding to the key, it is suitable to use a piezo element as the strain sensor 83. That is, since the amount of deviation of the part corresponding to the key of the sensing tension member 71 can be detected by the slight amount of deflection of the detection leaf spring 82, a wide dynamic range can be obtained and the detection accuracy can be improved. Furthermore, since the amount of bending of the detection leaf spring 82 is very small, the space is saved.

  FIG. 4 is a side view of a keyboard device for an electronic piano to which a spring mechanism according to the second embodiment of the present invention is applied.

  In the figure, a keyboard frame 200 is fixed to a shelf board 201 with screws 202 and 203. The keyboard frame 200 is provided with a guide 204 for restricting the horizontal movement of the key 300 when the key 300 is pressed, and a stopper 205 for restricting the vertical downward movement is placed. .

  The key 300 and the keyboard frame 200 are rotatably attached via a V-shaped plate spring 400. Cylindrical boss portions 401 and 402 are provided at predetermined positions on the inner facing surface of the opening of the V-shaped leaf spring 400, respectively. Screw holes are formed through the boss portions 401 and 402 toward the outer surface of the opening of the V-shaped plate spring 400. By screwing screws 403 and 404 into screw holes formed in the boss portions 401 and 402, respectively, the key 300 and the keyboard frame 200 are rotatably attached via the V-shaped plate spring 400. .

  In the keyboard apparatus configured as described above, when the performer depresses the key 300 to the maximum position, the key 300 moves as indicated by a one-dot chain line in the figure. At this time, the key 300 is moved to the position of the stopper member 205 due to the bending of the V-shaped leaf spring 400, but the key 300 is virtually rotated around the center VR ′. become. That is, when the conventional key rotation structure is used, it is necessary to configure the key so that the center VR ′ is the center of rotation. With this configuration, the length of the key is usually It must be longer than the length of the key 300 in FIG. For this reason, the size of the entire device must be larger than the keyboard device of FIG. Conversely, according to the keyboard device of the present embodiment, the overall size of the device can be reduced as compared with the conventional keyboard device.

It is a top view of the keyboard apparatus for electronic pianos which applied the spring mechanism which concerns on the 1st Embodiment of this invention. It is a right view of the keyboard apparatus for electronic pianos which applied the spring mechanism which concerns on the 1st Embodiment of this invention. It is a left view of the keyboard apparatus for electronic pianos which applied the spring mechanism which concerns on the 1st Embodiment of this invention. It is a side view of the keyboard apparatus for electronic pianos which applied the spring mechanism which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 70 ... Sensor apparatus, 70A ... Tension part, 71 ... Sensing tension member, 72 ... Compensation tension member, 73 ... Holding member, 74 ... Plate spring for tension, 80 ... Detection part, 81 ... Detection circuit Substrate, 82 ... detecting leaf spring, 83 ... strain sensor, 300 ... key, 200 ... keyboard frame, 400 ... V-shaped leaf spring

Claims (2)

A spring mechanism having a V-shaped leaf spring composed of both wing leaf springs formed by bending a planar leaf spring,
A first support portion for fixing the V-shaped plate spring to the keyboard frame is provided on a part of the outer surface of one of the wing plate springs.
A second support part for supporting the rear part of the key is provided on a part of the outer surface of the other wing part leaf spring among the wing part leaf springs,
A tangent line in contact with a part of the outer surface of the other wing leaf spring at the initial stage of the bending section formed by operating the key supported by the second support section, and the outer section at the end of the bending section. The distance from the position where the rear of the key is attached to the position where the rear part of the key is bent on the outer side surface of the other wing leaf spring is the distance from the virtual rotation center which is the intersection with the tangent line that touches a part of the side surface To be placed further away,
Wherein by the key is operated, the spring mechanism the key, characterized in that rotates about the virtual rotation center.   3. The spring mechanism according to claim 2, wherein a part of each outer surface of each of the blade blade springs is provided at a position closer to the opening than a bent portion of the V-shaped leaf spring.

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