JPS60116948A - Petal-like leaf spring and shock absorbing mechanism using petal-like leaf spring - Google Patents

Abstract

PURPOSE:To prevent the unsatisfactory operation of a head by absorbing the large braking torque generated at the contact surface of a gear and incorporating a leaf spring suppressing this braking torque to be lower than the starting torque in the gear. CONSTITUTION:When the drive torque from a motor is applied to a worm gear 46 via a worm, the tip 26, i.e., acting point, of a petal-like spring 21 and the tip 52, i.e., acting point, of a brake plate 48 pinch the upper and lower side faces of the worm gear 46, thereby the worm gear 46 applies the same rotation to a pinion 45. Furthermore, a caulking section 51 is adjusted to adjust the compression quantity of the petal-like leaf spring 21 so that the torque somewhat lower than the maximum torque of the worm gear 46 is transmitted to the pinion 45. Accordingly, even if the strong braking force is generated, the tip 26 of the leaf spring 21 is slipped, and the action larger than the said torque is not generated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a leaf spring configured as a beam of equal strength and a shock absorbing device using this leaf spring. This relates to a buffer mechanism inserted in part to prevent malfunction.

A so-called linear tracking mechanism that moves the head in a linear motion is used in a part of the head feeding device of a player in an audio device.

This linear tracking mechanism is used in some devices such as compact disc decks and record players, but because compact disc decks require relatively high-speed linear motion, there is a possibility that the head may malfunction once. When this occurs, it is often impossible to restart smoothly. This is because the braking torque between the worm directly connected to the motor and the worm gear meshing with the worm is greater than the starting torque of the motor. This example is specifically shown in FIG. That is, FIG. 1 shows a part of the head feeding mechanism of a compact disc deck, and a head 1 for reading information stored in the compact disc deck is supported by a housing 2 of the compact disc deck. The head 1 is attached to a head guide bar 3 so as to be able to move in parallel, and a rack 4 for being driven is cut in the side surface of the head 1. This rack 4 meshes with a pinion 7, which is the final stage of a gear train 6 connected to a motor 5, and is driven by the rotational force of the motor 5. The gear train 6 used here is composed of two sets of gear systems 8 and 9 equipped with large and small concentric synchronous gears and a worm 10 directly connected to the motor 5. worm gear 1
A pinion 12, which has a smaller diameter than the worm gear 11 and rotates in synchronization with the worm gear 11, meshes with a gear 13 on the larger diameter side of the gear system 8 that forms a pair. The pinion 7 has a smaller diameter than the gear 13.
is concentrically synchronous with gear 13, and as mentioned above, rack 4
Since the head 1 is in mesh with the head 1, the rotational motion of the motor 5 is finally converted into the linear motion of the head 1.

In the feeding mechanism configured as described above, the relative position of the head 1 to the compact disk deck is always controlled by electronic control such as a microcomputer, but there may be a problem with this electronic control or the control mechanism may not function properly. If this happens, a so-called overrun phenomenon occurs. When an overrun occurs, the head 1 deviates from the normal operating range and comes into forceful contact with a blocking point [a provided inside the housing 2, for example, and the linear movement of the head 1 is stopped. At this time, a part of the high kinetic energy generated in the rotor of the motor 5 is lost as frictional heat on the sliding surfaces of each gear in the gear train 6, but the overrun of the head 1 causes the motor 5 to overrun. Because the drive cannot be controlled, a worm circumferential braking force unique to the worm mechanism is generated between the worm lO directly connected to the rotating shaft of the motor 5 and the worm gear 11, and this acts as a braking torque for restarting the motor. Become. The braking torque generated between the worm lO and the worm gear 11 results in a large sliding resistance at their contact surfaces, and the sliding resistance between them is usually larger than the starting torque of the motor 5. Therefore, even if the motor 5 is energized in the reverse rotation direction to recover the head 1 from the blocking position a, it is generally impossible to start the head 1 in the opposite direction.

In order to prevent such malfunction of the head 1, a damper 14 may be provided as shown in FIG. It is not very desirable in terms of cotton and control.

The present invention was made in view of these points, and its purpose is not to directly control and stop the linear motion of the head 1 like the damper 14, but to suppress the large amount of noise generated on the contact surfaces of the gears in the gear train 6. Absorbs braking torque (sliding resistance),
To provide a leaf spring capable of suppressing the braking torque at least lower than the starting torque of a motor 5, and a buffer mechanism for preventing malfunction of a head 1 in which this leaf spring is incorporated into a gear.

That is, in this invention, a petal-shaped leaf spring is formed by forming several leaf spring units 1-, each having a shape that can be regarded as a beam of equal strength, around a support disk in the central part, thereby achieving the above-mentioned effect. At the same time, by inserting this petal-shaped leaf spring between the coaxial worm gear and pinion, if a braking torque exceeding a specified value is applied to the worm gear, it will cause slippage and restart the motor in the opposite direction. The feature is that it does not interfere.

This *rrA will be explained in detail below with reference to examples.

2 and 3 show a preferred embodiment of the petal-shaped leaf spring according to the present invention, while FIGS. 4 and 5 show a conventional general-purpose star-shaped spring. has been done. Second
In FIG. 3 and FIG. 3, the petal-shaped leaf spring 21 includes a support disk 23 provided with an insertion hole 22 in the center into which a shaft of a pinion, which will be described later, is inserted, and a support disk 23 integrally attached to the periphery of the support disk 23. For example, a petal-shaped leaf spring unit 24 is formed as a four-lobed curved beam of equal strength, and each leaf spring unit 1-24 has a dowel hole on the support disk 23 side. 25 are drilled.

In this embodiment, the leaf spring unit 24 has a circular outer periphery as shown in the plan view of FIG.
The inner peripheral portion of the leaf spring unit 24 is concave so that the cross-sectional width of the spring increases linearly from the tip 26 of the leaf spring unit 24 to the maximum width. This is because the leaf spring unit 24 is made of a beam having a uniform cross-sectional thickness so as to generate equal stress against external forces. In other words, the outer edge of bending, as given by the formula for a beam of equal strength, is: bending stress M: bending moment ■: moment of inertia of area e: distance from the neutral axis to the outer edge Z: section modulus (I/e) Since this refers to a beam where the stress takes a constant value depending on the tensile and compressive strength of the materials used, for example, the allowable stress value, it is necessary to set the section modulus Z in proportion to the distribution of bending moment +=M. be. Therefore, as shown by the two-dot chain line, a triangular plate may be formed in which the two sides facing the tip 26 of the temporary spring unit 24 are straight, but this is just a design problem. In addition, a dowel hole 2 drilled in the leaf spring unit 24
5 is for the purpose of maintaining the posture in the circumferential direction and for the reason that the leaf spring unit 24 is formed integrally with the support disk 23, so the condition of an equal strength beam is no longer satisfied, and the bending moment 1 is It is provided for the purpose of adjusting the relationship between ~M and the section modulus 2, and the position and diameter are set depending on the shape of each leaf spring unit 24, and it is meant to approximately restore the linearity of the section change.

The differences between this petal-shaped leaf spring 21 and the general-purpose star-shaped spring 27 shown in FIGS. 4 and 5 will be described below.

This general-purpose star-shaped spring 27 is integrally formed with, for example, a four-leaf leaf spring unit 29 of a support plate 28 supported as a cantilever. In the example shown in the accompanying drawing, each version spring unit 29 is a beam of equal strength with a triangular outline, but is formed so that it receives a load only at the free end of its tip 30, and its base 31 is connected to the support plate 28. It is integrated and formed so that the cross section is concave upward in the figure, as shown in FIG. In this state, when a force is applied to the tip 30 of each leaf spring unit 29, stress is concentrated on the base portion 31, and a notch effect is generated in the joint portion 32 of each adjacent leaf spring unit 29, so that stress is concentrated. For this reason,
There is a disadvantage that the fatigue limit is lowered at this location and fatigue failure may occur. On the contrary, in the petal-shaped leaf spring 21 according to the present invention, the notch effect is less likely to occur, so fatigue failure caused by the notch effect does not occur. In addition, the number of support points is 8 for the petal-shaped leaf spring 21, and 8 for the general-purpose star-shaped spring 2.
7 has 4 points, so the petal-shaped leaf spring 2 according to the present invention
The amount of elastic energy that 1 can store is extremely large. This indicates that the petal-shaped leaf spring 21 is extremely resistant to fatigue failure and has a small size and a large elastic energy storage capacity. Although this embodiment shows the case where the leaf spring unit 24 has four leaves, the above effect can be obtained if the leaf spring unit 24 has three or more leaves.

Next, by utilizing the above-mentioned characteristics of the petal-shaped leaf spring 21 that it is resistant to fatigue damage, small in size, and has a large elastic energy storage capacity, the petal-shaped leaf spring 21 is used to prevent malfunction of the head in a compact disc deck. A buffer mechanism incorporating the leaf spring 21 will be explained.

A preferred embodiment of the present invention is shown in FIG. 6, and will be described with reference to this part A. Note that FIG. 6 is a sectional view of a buffer mechanism in which a petal-shaped leaf spring 21 is incorporated into a portion of the gear system 9 in the conventional example described above. Gear 9 in Figure 1
, the pinion 12, the worm gear 11, and their associated mechanisms have already been explained, so their explanation will be omitted here, and the explanation will be limited to those related to the present invention. This buffer mechanism 40 includes a fixed shaft 42 fixed to a substrate 41, a pinion assembly 43 that rotates around the fixed shaft 42, and a pinion assembly 43 that rotates around the fixed shaft 42.
It is equipped with a stopper 44 that rotatably holds the container. The pinion system assembly 43 includes a pinion 45, a worm gear 46 located above the pinion 45 in the figure, a τ petal-shaped plate spring 21, a back-up plate 47 that supports the petal-shaped plate spring 21 from below, and a worm gear 46 located above the pinion 45 in the figure. It consists of a brake plate 48 that presses down the gear 46 from above.

The back-up plate 47 is integrally disposed at the upper end of the teeth of the pinion 45, and a protrusion 49 is protruded from the upper surface of the back-up plate 47 at a position corresponding to the knock hole 25 of the petal-shaped leaf spring 2I. The petal-shaped leaf spring 21 is inserted into the shaft portion 50 of the pinion 45, and is set so as not to change its position in the circumferential direction while the knock hole 25 is fitted into the projection 49.

In this embodiment, two petal-shaped ridge springs 21 are inserted, but this is selected based on the relative relationship between the braking torque and the spring coefficient, and is a design issue. The worm gear 46 is similarly inserted into the shaft portion 50 of the pinion 45, and eight points of the tip 26, which are the points of action of the petal-shaped leaf spring 21, are in contact with the lower surface.

A brake plate 48 is inserted into the shaft portion 50 at the upper part of the worm gear 46, and a caulking portion 51 on the outer periphery of the shaft portion 50 causes the tip 52 of the brake plate 48 to apply a set force to the upper surface of the worm gear 46. They are caulked and fixed together while they are in contact with each other. In this state, the worm gear 46 meshes with the worm 10 directly connected to the motor 5, and the large diameter gear 13 of the adjacent gear 8 meshes with the pinion 45.

In the above configuration, when the driving torque from the motor 5 is applied to the worm gear 46 by the worm 10, the tip 26, which is the point of action of the petal-shaped plate spring 21, and the tip 52, which is the point of action of the brake plate 48, are moved above and below the worm gear 46. Since the worm gear 46 holds the sides of the pinion 45, the worm gear 46 gives the same rotation to the pinion 45. At this time, the caulking portion 51
By adjusting the amount of compression of the petal-shaped leaf spring 21 and adjusting the frictional force, it is possible to transmit a torque slightly lower than the maximum torque of the worm gear 46 to the pinion 45. If you do this, pinion 45
Even if a strong braking force is generated in the rear stage, the kinetic energy of the motor 5 and the worm 10 in the front stage of the worm gear 46 will be lost in the rear stage after the pinion 43 because the tip 26 of the petal-shaped leaf spring 21 slips. cannot produce an effect greater than the 1-lux obtained by adjusting the frictional force of . Therefore, a strong braking force is generated and the motor 5
Even if the machine stops, it can be restarted in the opposite direction without any hindrance.

As described above, according to the present invention, it is possible to provide a novel leaf spring that is resistant to fatigue fracture, is small in size, and has a strong elastic energy absorption ability, and also allows the user to use the spring as a type of clutch device. It is possible to provide a very effective damping mechanism for the read head in a linear tracking device of a disk deck to prevent malfunction.

[Brief explanation of drawings]

FIG. 1 is a schematic plan view showing a part of the feeding mechanism of a conventional compact disk drive, FIG. 2 is a plan view of a petal-shaped leaf spring according to the present invention, and FIG. 3 is a cross-sectional view taken along the line A-A. Fourth
The figure is a plan view of a conventional general-purpose star spring, and Figure 5 is its B-B
The line sectional view and FIG. 6 are partial sectional views of the buffer mechanism according to the present invention. In the figure, l is the head, 2 is the housing, 3 is the head guide, 4 is the rack, 5 is the motor, 6 is the gear train, 7 is the pinion, 8, 9
is gear system, 10 is worm, 11 is worm gear, 1
2 is a pinion, 13 is a gear, 14 is a damper, 21 is a petal-shaped leaf spring, and 22 is an insertion hole. 23 is a support disk, 24 is a leaf spring unit, 25 is a dowel hole, 26 is a tip of the leaf spring unit 1-, 27 is a general-purpose star spring, 28 is a support plate, 29 is a leaf spring unit, and 30 is a leaf spring unit. Tip, 40 is a buffer mechanism, 41 is a substrate, 42
is a fixed shaft, 43 is a pinion system assembly, 44 is a grommet shaft, 4
5 is a pinion, 46 is a worm gear, 47 is a back-up plate, 48 is a brake plate, 49 is a protrusion, 50 is a shaft portion, 51
This is the caulking part. Patent Applicant General Co., Ltd. Patent Attorney Takuya Ohara Figure 1 Figure 2 Figure 4 Figure 6

Claims (1)

[Scope of Claims] (1) A petal-shaped leaf spring formed by integrally forming a plurality of petal-shaped leaf spring units formed of curved beam-like beams of equal strength on the periphery of a support disk. (2. The petal-shaped leaf spring according to claim (1), characterized in that the support disc side of the plate A unit is provided with knock holes for obtaining equal strength. (3) A linear tracking mechanism in audio equipment that has a worm gear driven by a worm directly connected to a motor and a pinion that rotates in synchronization with the rotation of the worm gear, and is transmitted from the pinion through a gear transmission groove. In the feeding mechanism for feeding the reading head, the pinion is loosely fitted onto a fixed shaft provided upright on the board, and a nopeck-up plate is integrally attached to the shaft of the pinion, and on the back-up plate, A petal-shaped leaf spring formed by integrally forming a plurality of leaf spring units formed of curved beam-like beams of equal strength on the periphery of a support disk is arranged so as to be able to rotate integrally with the pinion, and A worm gear is fitted into the bearing of the pinion so as to come into contact with the tip of each spring unit of the petal-shaped plate spring, and a friction force between the petal-shaped plate spring and the worm gear causes a □
A buffer mechanism using a petal-shaped plate spring, characterized in that the worm gear is pressed against the petal-shaped plate spring by a control plate so that the generated torque is slightly smaller than the maximum torque of the worm gear.