JPH05296270A - Coned disc spring device - Google Patents

Abstract

PURPOSE:To widen an operating range of a coned disc spring device whose source of elasticity is formed by combining a plurality of coned disc spring elements and to realize various loaded conditions within the operating range by interposing an inversion stopping member between the coned disc spring elements disposed opposite to each other. CONSTITUTION:A plurality of coned disc spring elements 8 each of which is made to abut on the back of a movable pulley 5 are erected in series with one another outside a V-groove formed between a fixed pulley 4 and the movable pulley 5 both of which are made in pairs and mounted on a pulley shaft 7 with the movable pulley 5 being movable along the pulley shaft 7, and alternate projecting and recessed faces of each coned disc spring element 8 and disposed by a predetermined number while the backs of the elements face each other. A circular inversion-stopping plate 9 crossing the outer peripheral edge of each coned disc spring is enclosed in a space that each pair of adjacent elements forms. If one of the coned disc springs facing each other has reached a point of sticking earlier than the other coned disc spring by reason of its predetermined stress value, further deformation of the former is prevented while deformation of the latter is continued. As the diameter of winding of a V-velt decreases, each coned disc spring element 8 is deformed and approximates a flate plate, but is prevented from being deformed past the point of sticking by the inversion stopping plate 9 and is therefore not inversed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc spring device used in a device such as a movable transmission pulley.

[0002]

2. Description of the Related Art As a conventional disc spring device, there is one used for a movable transmission pulley shown in FIG. FIG. 4 shows a continuously variable transmission in which rotary drive is transmitted from a drive shaft to a pulley of a driven shaft via a V belt. As shown in the figure, the driven shaft 10 is rotatably supported by a frame 11 via a bearing 12. Furthermore, the driven shaft has a bearing 1
A V-shaped pulley 16 is attached to the driven face 15 via the rollers 3 and 14. The V-shaped pulley 16 includes a fixed pulley 17 and a movable pulley 18, and a V-belt 19 has a plurality of disc springs 20 superposed on the outside of the movable pulley 18. In the continuously variable transmission having such a movable speed change pulley, the movable pulleys of the paired pulleys are opened and closed to increase or decrease the winding diameter of the V-belt 19 wound around the gap to perform the speed change. In this case, a disc spring device having a plurality of disc spring elements arranged side by side is arranged outside the movable pulley in order to satisfy the opening / closing stroke of the pulley from low speed rotation to high speed rotation.

Among the general characteristics of the Belleville spring element, there is a relationship between the deformation displacement of the Belleville spring and the pressing load, in which the pressing load increases with the increasing deformation displacement, or gradually increases after a predetermined displacement. .. On the other hand, the pressing load reaches a peak with an increase in the deformation displacement of the disc spring, and thereafter, the pressing load decreases as the disc spring goes upright (the contact point).

As described above, the continuously variable transmission transmits the rotation of the drive shaft to the driven shaft by the movable pulley and the V-shaped belt. If the pressing load of the movable pulley is small, the transmission surface between the pulley and the belt is reduced. On the other hand, slippage occurs, and on the other hand, the larger the pressing load of the disc spring element, the more pressing force acts between the pulley and the belt than the predetermined pressing load. Transmission efficiency is poor.

When the pressing load is small and slippage occurs on the transmission surfaces of the pulley and the belt, the slippage can be prevented by arranging the Belleville spring elements in parallel. If a disc spring element having a characteristic that the pressing load increases with an increase is adopted, in the state shown in the lower half of FIG. 4, the belt is pressed with an excessive pressing force, so that the transmission efficiency is reduced. Therefore, it is conceivable to employ a disc spring that has a characteristic that the pressing load reaches a peak with the increase of the deformation displacement and then the pressing load decreases toward the close contact point, without decreasing the transmission efficiency.

[0006] Such a disc spring element further improves the transmission efficiency of the driving force by the belt by setting both sides of the deformation displacement and the pressing load characteristics, including the peak time of the pressing load, as the operating range with respect to the moving range of the movable pulley. Can be higher.

[0007]

When a disc spring device is used in a belt type continuously variable transmission, in view of improving transmission efficiency, the purpose is to select a disc spring element having the above-mentioned characteristics. However, in order to increase the moving distance of the movable pulley, it is necessary to dispose a plurality of disc spring elements facing each other. However, in such a plurality of Belleville spring elements, due to the variation in the load of each Belleville spring, the element with a high pressure load pushes the element with a low pressure, and from the above-described pressure load-deformation displacement attenuation curve Along with the generation of noise, the disk spring element itself is inverted to draw a deformation curve. That is, the reversing disc spring element prevents the movable pulley from moving properly, which not only deteriorates the transmission efficiency but also adversely affects the transmission characteristics of the continuously variable transmission. Therefore, the present invention does not reverse within the operating range even if the load of each disc spring varies when a pressing force is applied to the disc spring element, and the pressing load is set to the performance in the initial setting state. An object is to provide a disc spring device that can be kept.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and even if the load of each disc spring element varies, each element does not invert, so that noise is generated at the time of inversion. It is possible to adopt a Belleville spring element that has a peak in the Belleville spring load within the operating range of deformation and displacement of each element of the Belleville spring, and avoids a reduction in transmission efficiency at high speed rotation when using such an element. Is what you can do.

In order to achieve such an object, in a disc spring device in which a plurality of disc spring elements are combined and used as an elastic source, a reversal prevention member is interposed between the disc spring elements arranged so as to face each other. ..

[0010]

EXAMPLES An example of the present invention will be described in detail below.
Although the description that overlaps with the description described with reference to FIG. 4 is omitted, in FIG. 1, the power from the drive source 1 is transmitted to the V-shaped pulley 3 of the continuously variable transmission by the V-shaped belt 2. This V
The mold pulley 3 is erected so as to have a pair of fixed pulleys 4 and a sloped surface facing a movable pulley 5 slidably supported by a movable pulley support member, and between the V grooves formed by the sloped surfaces. A V-shaped belt 2 is endlessly wound so as to transmit a driving force from a pulley axially supported by a drive shaft of a drive source 1. The power from the drive source 1 is transmitted by the frictional force between the end surface of the V-shaped belt 2 and the inclined surface of the V groove of the pulley of the continuously variable transmission. This frictional force is generated by being pressed by the compressive deformation force of the plurality of disc-shaped disc spring devices 6 contacting the outside of the movable pulley 5, and the frictional force and V
The position of the V-shaped belt on the V-groove inclined surface varies depending on the relationship with the rotation speed of the mold belt. That is, when the V-shaped belt 2 starts rotating, the V-shaped belt 2 is wound around a position where the winding diameter is large.
The winding diameter decreases as the rotation speed increases. When this winding diameter decreases, the V-groove gap between the pulleys expands, and the movable pulley 5 retracts on the movable pulley support member.
In a general elastic body, its load (pressing load) increases according to the amount of deformation due to the load-deformation characteristic, but in the present invention, since the above-mentioned disc spring element having a peak in the load-deformation displacement characteristic is adopted. In addition, the wrapping diameter of the V-shaped belt and the frictional force of the pulleys related to the V-shaped belt are applied to the rotational drive in an optimal state to improve the transmission efficiency.

FIG. 2 shows the load-displacement characteristics of each disc spring element used in the present invention. Each disc spring element has a dish shape in which its center is deformed into a concave shape, and when a gradual stress is applied in a direction in which the outer peripheral edge of the dish becomes a flat plate,
The stress increases with the amount of dish deformation, and then decreases after reaching a peak. In this case, in the vicinity of the inflection point of the decreasing curve, the central portion and the outer peripheral edge of the Belleville spring element become flat (contact point), and then the Belleville spring element reverses and the irregularities are reversed. After the reversal, the disc spring element shows an increase or decrease in stress according to the initial displacement amount. As described above, the Belleville spring element used in the present invention adopts a range in which the operating range thereof increases and decreases including the peak load in FIG. 2, and does not require the deformation pressing force after the contact point. However, if multiple disc spring elements are arranged in series and a uniform stress is applied between the elements, the amount of deformation between the disc spring elements may vary due to variations in the mass of each element, the plate thickness, or the composition of the material. May be different. This means that the load-deformation characteristic curve of each element in FIG. 2 is not drawn uniformly, and some elements reach the contact point early and those adjacent elements do not reach the contact point. Will exist. Therefore, when each element is arranged in series due to the variation in load-deformation characteristics of each element, the element with a large load (not reaching the contact point) has a small load due to the deformation between the elements (it quickly reaches the contact point). An element with a small load will generate noise and will flip when it reaches the peak point of the load. Such variations in the deformation characteristics of the respective elements cause fluctuations in the frictional force between the pulley and the belt, resulting in a reduction in the transmission efficiency of the rotational driving force. From this point of view, in the present invention, the variation of each disc spring element is allowed, and the element is provided with a displacement limiting member that does not uniformly reverse even when the contact point is reached.

FIG. 3 shows an embodiment of the structure of a disc spring device 6 according to the present invention. A pair of fixed pulley 4 and movable pulley 5 mounted on a pulley shaft 7, and the movable pulley 5 is a pulley shaft. 7, a plurality of disc spring elements are erected in series outside the V groove formed between the pulleys so as to come into contact with the back surface of the movable pulley. A predetermined number of sheets are arranged alternately so that the front and back sides of the sheets are back to back. A circular reversal prevention plate 9 (reversal prevention member) that vertically cuts the outer peripheral edge of the disc spring is included in the space formed between the two adjacent elements.
The reversal prevention plate 9 is made of a highly rigid material and has a diameter substantially equal to the diameter of the disc spring, and separates the load-displacement characteristic of each disc spring prevention. That is, when one of the pair of disc springs facing each other reaches the contact point earlier than the other disc spring element by a predetermined stress value (load), further deformation is prevented and the other deformation is continued. It was done. As a result, when the winding diameter of the V-belt becomes smaller, the disc spring element deforms and approaches the flat plate, but the reversal prevention plate prevents deformation after the contact point and does not reverse. As is apparent from the above description, when the disc spring device of the present invention is used in an continuously variable transmission, each disc spring element adapted to continuously shift from low speed rotation to high speed rotation has a plurality of disc spring elements. It is possible to constrain the deformation-stress characteristics in the operating range, to avoid noise caused by further deformation, and to introduce a disc spring with a peak load in the operating range into the continuously variable transmission. Therefore, it is possible to avoid a significant decrease in transmission efficiency during conventional high-speed rotation.

[0013]

According to the Belleville spring device of the present invention, the load-deformation characteristics of a plurality of Belleville spring elements are constrained within the operating range to avoid noise caused by further deformation and to operate further. A Belleville spring having a peak of stress (load) in the range can be introduced. Therefore, the operating range can be widened and various load states can be obtained in the operating range.

[Brief description of drawings]

FIG. 1 is a sectional view of a speed change pulley device using a disc spring device of the present invention.

FIG. 2 is an explanatory diagram of a load-displacement curve of a disc spring element.

FIG. 3 is an explanatory view of a disc spring device of the present invention.

FIG. 4 is a schematic explanatory view of a speed change pulley device using a conventional disc spring device.

[Explanation of symbols]

 1 Drive Source 2 V-Type Belt 3 V-Type Pulley 4 Fixed Pulley 5 Movable Pulley 6 Disc Spring 7 Pulley Shaft 8 Disc Spring Element 9 Reversal Blocking Plate (Reversal Blocking Member)

Claims (1)

[Claims] 1. A Belleville spring device in which a plurality of Belleville spring elements are combined and used as an elastic source is characterized in that a reversal blocking member is interposed between the Belleville spring elements arranged to face each other. Disc spring device.