JPH0643560Y2 - Flywheel - Google Patents

Description

[Detailed Description of the Invention] (Industrial field of application) The present invention relates to a flywheel used for a tape recorder and the like, and particularly, an inexpensive and easy to assemble structure in which an annular metal plate is attached to a pulley made of synthetic resin. High flywheel.

(Prior Art) In a tape recorder, a flywheel having a structure in which an annular metal plate is mounted on a pulley made of synthetic resin to increase its inertia moment is often used.

Generally, a flywheel of this type has a plurality of engaging slits radially provided on the peripheral portion of the center hole of the annular metal plate, and a fitting tubular portion protruding from the center of the pulley and fitted into the center hole. After inserting a plurality of engagement projections radially provided on the peripheral surface, the engagement projections are engaged with the peripheral edge of the center hole of the annular metal plate by rotating the annular metal plate and the pulley relatively by a predetermined angle. The engaging projection and the one side surface of the pulley sandwich the annular metal plate.

(Problems to be solved by the invention) By the way, it is preferable that the annular metal plate mounted on the pulley is as large and thick as possible in order to increase the moment of inertia and enhance the flywheel effect. However, the thickness tolerance of the cold-rolled steel sheet, which is the constituent material of the annular metal sheet, is JI.
It is specified by S-G3141, and the variation width of thickness increases as the thickness increases. Therefore, if a thick cold-rolled steel plate is used as the material of the annular metal plate and the annular metal plate is manufactured by press working, it is undeniable that the thickness of the annular metal plate varies. If the thickness of the annular metal plate varies, it becomes difficult to reliably hold the annular metal plate by the engaging projection and the pulley, and the mounting workability also deteriorates.

In order to prevent such a problem, for example, a special material whose thickness variation is minimized is used as the material for forming the annular metal plate, or the dimension between the pulley and the claw portion of the engaging projection is accurately controlled. Will be required. Therefore, the manufacturing cost cannot be denied.

Further, in the above-described structure, since the annular metal plate and the pulley are fitted in the axial direction and then the annular metal plate and the pulley are relatively rotated, the annular metal plate is attached to the pulley. It is difficult to automate the assembly process.
Further, in order to facilitate the above rotation, it is necessary to provide a minute gap between the center hole of the annular metal plate and the fitting cylindrical portion of the pulley. Since it is necessary to make the fitting accuracy sufficiently high, it becomes a factor of increasing the manufacturing cost.

The present invention has been made in consideration of such a situation, and its purpose is to be simple with respect to a synthetic resin pulley without being affected by the variation in the thickness of the annular metal plate constituent material.
Another object of the present invention is to provide a flywheel having a structure in which an annular metal plate is securely mounted and which is inexpensive and easy to assemble.

(Means for Solving the Problems) The flywheel according to the present invention is provided with a synthetic resin pulley,
An annular metal plate is attached and held by using a holding member, and a fitting cylinder portion that fits into a center hole of the annular metal plate is provided at the center of one side surface of the pulley in a protruding manner. At the same time, an abutting portion that abuts on one side surface of the annular metal plate fitted to the fitting tubular portion is provided.

On the other hand, as the holding member, a fitting body that is press-fitted along the axial direction of the fitting tubular portion of the pulley to crimp the fitting tubular portion into the center hole of the annular metal plate, An abutting surface portion that abuts on the other side surface of the annular metal plate fitted to the tubular portion to regulate the press-fitting amount of the fitting body into the fitting tubular portion, and the fitting at a position regulated by the abutting surface portion. A flange is provided which abuts against the other side surface of the annular metal plate by the press-fitting of the united body and is elastically deformed, and presses the annular metal plate by a warping reaction force to sandwich it between the pulley and one side surface of the pulley.

The holding member is press-fitted into the pulley with the annular metal plate interposed therebetween so that the annular metal plate is clamped and held between the pulley and the holding member. .

(Operation) According to the present invention, one side surface of the annular metal plate inserted through the annular tubular portion of the pulley is brought into contact with the abutting portion, and in this state, the fitting body of the holding member is fitted into the fitting tubular portion of the pulley. When the contact surfaces of the holding members are pressed into contact with the other side surface of the annular metal plate, the brim of the pulley elastically deforms and presses the other side surface of the annular metal plate. Is elastically deformed with the pulley and is sandwiched between the flange.

Therefore, even if the thickness of the annular metal plate varies, the annular metal plate is sandwiched between the abutting surface of the pulley and the abutting surface of the holding member in accordance with the thickness, and the position of the annular metal plate is regulated by the elastically deformed brim. Since it is pressed and sandwiched between the pulley and one side surface of the pulley, the annular metal plate is attached and held very firmly regardless of its thickness.

Embodiment An embodiment of the flywheel according to the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing the structure of a flywheel according to an embodiment, and FIG. 2 is an exploded perspective view.

The flywheel 1 is generally a pulley 2 made of synthetic resin.
And a holding member 12 for mounting and holding the ring-shaped metal plate 3 on the pulley 2.

The disk-shaped pulley 2 has a V-shaped belt groove 4 on the outer peripheral side surface thereof, and has a first fitting cylindrical portion 5 at the central portion on the lower surface side (one side surface) and the fitting protrusion 5 An annular abutting portion 6 is formed on the outer periphery of the above, and a second fitting tubular portion 7 is coaxially and integrally formed at an intermediate position between the annular abutting portion 6 and the fitting tubular portion 5. The first fitting cylinder 5 is intended to be integrated by press-fitting the lower end portion of the shaft 11 to be described later to the circular hole 5 in _1, second fitting cylinder 7 ring the outer periphery it is intended to be fitted into the center hole 3 ₁ of the metal plate 3.

Further, the first annular wall 8 is provided on the upper surface side (the other surface side) of the pulley 2.
The second annular wall 9 and the second annular wall 9 are integrally formed coaxially with each other, and the outer surface of the outer second annular wall 9 is provided with teeth 10 that mesh with a gear (not shown).

The shaft 11 is, for example, a capstan of a tape recorder.

For such a pulley 2, the annular metal plate 3 has a central hole.
3 ₁ is fitted into the second fitting tubular portion 7, and the upper surface thereof is press-fitted to a position where it abuts on the abutting portion 6 and mounted on the lower surface side of the pulley 2.

On the other hand, the holding member 12 is a short-axis cylindrical fitting body 13 press-fitted between the first fitting cylinder portion 5 and the second fitting cylinder portion 7 of the pulley 2, and the fitting body 13 Tsuba integrally formed on the lower end surface of the
14 and. In addition, the base of this collar 14 has the second
The contact surface portion 14 for contacting the other side surface of the annular metal plate 3 fitted to the fitting cylindrical portion 7 of the above and for regulating the press-fitting fitting amount of the fitting body 13 to the fitting cylindrical portions 5 and 7. ₁ is formed, and further, a plurality of small projections 12 ₁ are formed in an annular shape on the outer peripheral surface of the fitting body 13.

Therefore, the collar 14 has an inverted umbrella shape that is inclined upward from the base of the fitting 13 toward the outer periphery as shown by the chain double-dashed line in FIG. When the holding member 12 is attached to the pulley 2 with the annular metal plate 3 sandwiched between the holding member 12 and the lower surface side of the pulley 2, that is, the first fitting cylinder portion 5 and the second fitting cylinder of the pulley 2 are attached. When the fitting body 13 is press-fitted into the portion 7 until the abutment surface portion 14 ₁ abuts on the other side surface of the annular metal plate 3, the collar 14 has its outer peripheral edge portion on the lower surface of the pulley 2. And is elastically deformed downward and is pressed against the lower surface of the pulley 2 by its reaction force.

At this time, the small protrusions 12 ₁ firmly press the inner peripheral surface of the fitting body 13 onto the outer peripheral surface of the fitting tubular portion 5, whereby the inner peripheral surface of the first fitting tubular portion 5 is firmly attached to the shaft 11. To crimp. At the same time, the small projection 12 ₁ presses the inner peripheral surface of the second fitting cylindrical portion 7 and firmly presses the outer peripheral surface thereof into the central hole 3 ₁ of the annular metal plate 3.

By this crimping, the holding member 12 (fitting body 13) itself cannot be easily pulled out from the pulley 2 (fitting tubular portions 5 and 7).

A gear 15 is provided on the upper side of the flywheel 1 by being press-fitted into the shaft 11. The gear 15 is obtained by forming the small diameter gear main body 15 ₂ integrally on the upper surface center of the circular base plate 15 _1, the inner peripheral surface of the first annular wall 8 the outer peripheral surface of the circular base plate 15 ₁ of the pulley 2 It is provided by press fitting. And this gear
As shown in FIG. 1, the flywheel 1 in which the shaft 15 is mounted has its shaft 11 inserted through a bearing 18 mounted on a substrate 17,
By inserting the retaining ring 19 into the annular groove 11 ₁ of 11
It is rotatably attached to.

According to the flywheel having the above-described configuration, the annular metal plate 3 is fitted onto the outer periphery of the second fitting cylinder portion 7 of the pulley 2, and in this state, the first fitting cylinder portion 5 and the second fitting cylinder portion are When the fitting body 13 of the holding member 12 is press-fitted between the fitting body 13 and 7,
14 ₁ is pressed into a position where it abuts the other side surface of the annular metal plate 3. As a result, the annular metal plate 3 is sandwiched on both sides by the annular contact portion 6 of the pulley 2 and the contact surface portion 14 ₁ of the holding member 12, and the mounting position thereof is restricted.

In this state, the collar 14 is elastically deformed, and the reaction force abuts against the annular metal plate 3 to press the annular metal plate 3 against the lower surface of the pulley 2, so that the annular metal plate 3 is placed between the flange 14 and the pulley 2. It will be firmly clamped in. Moreover, the fitting body 13 press-fitted between the first and second fitting tubular portions 5 and 7 has the small projection 1
Because it is firmly crimped on the outer peripheral surface of the fitting cylinder 5 by the action of 2 _1, and because is firmly pressed against the outer peripheral surface of the fitting cylinder 5, its involuntary escape effectively prevented Be done. Furthermore, since the first and second fitting tubular portions 5 and 7 pressed by the action of the small protrusions 12 ₁ are firmly crimped to the shaft 11 and the annular metal plate 3, respectively, the press-fitted fitting state is firm. Retained,
The annular metal plate 3 is stably mounted and held on the pulley 2.

Further, with such a structure, the holding member 12 can be assembled by simply press-fitting the holding member 12 to the pulley 2 in the axial direction, so that the assembling workability is good and it is also suitable for automation. is there. Further, even if the thickness of the annular metal plate 3 varies, the contact portion 6 and the contact surface portion on both sides thereof
Since press-fitting of the holding member 12 with respect to the pulley 2 is restricted by the abutment of the 14 _1, it is possible to stabilize and reliable of clamping retention of the annular metal plate 3. Therefore, there is no need for special dimensional control or the like as in the conventional art, and the production cost can be reduced.

The present invention is not limited to the above embodiment. For example, the same can be applied to a structure in which the annular metal plate 3 is mounted on the upper surface side of the pulley 2, and the thickness and diameter of the annular metal plate 3 may be determined according to the specifications. In short, the present invention can be modified in various ways without departing from the scope of the invention.

(Effect of the Invention) As described above, according to the flywheel of the present invention, it is not necessary to control the thickness of the annular metal plate with high accuracy, and the cost can be reduced. Moreover, since it is only necessary to press-fit the holding member into the pulley in the axial direction, the assembly work can be easily performed.

[Brief description of drawings]

FIG. 1 is a sectional view showing the structure of a flywheel according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view of the same embodiment. 1 …… Flywheel, 2 …… Pulley, 3 …… Ring metal plate, 3 ₁
...... Center hole, 5 ...... First fitting cylinder part, 6 ...... A annular contact part, 7 ...
… Second fitting cylinder part, 11 …… Shaft, 12 …… Holding member, 12 ₁ ……
Small protrusions, 13 ...... Mating body, 14 ...... Tsuba, 14 ₁ …… Abutment surface part.

Claims (2)

[Scope of utility model registration request] 1. A pulley (2) made of synthetic resin, an annular metal plate (3), and a holding member (12) for mounting and holding the annular metal plate on the pulley, wherein the pulley has a central portion on one side surface thereof. abuts the abutment on the center hole (3 ₁₎ fitting cylinder portion fitted to the annular metal plate so as to project and (7), on one side of the annular metal plate fitted to the fitting tube The holding member is press-fitted inside the fitting tubular portion of the pulley along the axial direction thereof, and the fitting tubular portion is crimped to the center hole of the annular metal plate. The fitting body (13) to be made to come into contact with the other side surface of the annular metal plate which is provided at the end portion of the fitting body and is fitted into the fitting cylinder portion when the fitting body is press-fitted into the fitting cylinder portion. the contact face portion to regulate the press-fitting amount (14 _1), the annular metal plate by press fitting of the fitting portion to the position regulated by the contact face portions Flywheel elastically deformed in contact with a side surface those, characterized in that a flange (14) sandwiched between one side surface of said presses the annular metal plate pulley by its reaction force. 2. A small projection (12 ₁ ) is provided on the peripheral surface of the fitting body of the holding member to press the outer circumference of the fitting tubular portion of the pulley into the center hole of the annular metal plate fitted therein. The flywheel according to claim 1, wherein