JP4178643B2 - Belt type continuously variable transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention comprises a transmission belt comprising a plurality of flat plate elements arranged without gaps, and an endless band extending over the flat plate element row, and the flat plate elements are inclined about a rocking edge so that an input / output pulley is provided. The present invention relates to a belt type continuously variable transmission wound around.
[0002]
[Prior art]
An example of a conventional belt-type continuously variable transmission is disclosed in Japanese Patent Application Laid-Open No. 7-12177. As shown in FIGS. 6 and 7, this belt-type continuously variable transmission includes a plurality of flat plate elements 20 arranged without gaps, and a transmission belt 10 formed by spanning the endless band 3 over the flat plate element row, It is wound between a pair of input pulleys and output pulleys composed of a fixed pulley 4 and a movable pulley 5.
[0003]
FIG. 7 is a side view of the transmission belt 10 from which the endless band 3 is omitted. As shown in this figure, the transmission belt 10 has a flat plate element 20 between the fixed pulley 4 and the movable pulley 5. The rocking edge 6 is wound around by being inclined about the rocking edge 6, and the rocking edge 6 is formed downward from the upper end of the shoulder 20s (normally, for example, at a position 1/5 from the upper end of the shoulder 20s) ( (See FIG. 6).
[0004]
[Problems to be solved by the invention]
Conventionally, the angle α formed by the sheave surface 4f of the fixed pulley 4 and the sheave surface 5f of the movable pulley 5 is configured to be equal to the angle β formed by the side surfaces 20f and 20f connected to the shoulder portion 20s of the flat plate element 20. The shoulder side surface 20f of the element 20 abuts substantially uniformly against the fixed pulley sheave surface 4f or the movable pulley sheave surface 5f.
[0005]
For this reason, the distribution of the pulley thrust N with respect to the flat plate element 20 becomes a substantially uniform distribution with respect to the shoulder side surface 20f of the flat plate element 20, as shown in FIG. Therefore, the action center C2 of the pulley thrust N with respect to the flat plate element 20 is located substantially at the center between the shoulder side surfaces 20f.
[0006]
FIG. 9 is a side view showing a flat element row. Considering a state where torque is transmitted from the pulley to the flat element 20-1 and a compressive force is generated between the flat element 20-1 and the flat element 20-2, this state is the pulley thrust of the flat element 20. It can be considered that the frictional force F acts on the center of action C2 of N along the sheave surface. In this case, since the center of action C2 of the pulley thrust N and the rocking edge 6 are separated by a distance ΔL2, a moment M2 (= F × ΔL2) acts on the flat plate element 20 in the direction of the arrow.
[0007]
Therefore, as shown in FIG. 7, the flat plate element 20 transmitting torque is wound around the pulley while being tilted backward by the moment M2 in FIG. 9, so that both shoulder side surfaces 20f and 20f of the flat plate element 20 are wound. However, instead of contacting the sheave surface 4f of the fixed pulley 4 and the sheave surface 5f of the movable pulley 5 with the entire element side surface, for example, a portion as shown in a region X in FIG. In this case, the friction coefficient with respect to the sheave surface is reduced due to the extreme wear of a part of the flat plate element 20, so that there is room for further improvement in the transmission torque capacity of the transmission belt 10 in the conventional transmission.
[0008]
The problem to be solved by the present invention has been made in view of the above-mentioned fact, and suppresses backward tilting of the element due to the moment generated between the pulleys, and the pulley sheave surface and the element side surface facing the sheave surface. It is an object of the present invention to prevent a reduction in the coefficient of friction due to wear of the elements and to improve the transmission torque capacity of the belt type continuously variable transmission.
[0009]
[Means for Solving the Problems]
For this purpose, the belt type continuously variable transmission according to the first aspect of the present invention comprises a plurality of flat plate elements arranged without gaps, and a transmission belt comprising an endless band spanning the flat plate element row. In the belt-type continuously variable transmission wound between the input and output pulleys by inclining around the rocking edge, the shoulder portion on which the endless band is spanned on the flat plate element on the side surface facing the sheave surface It is configured as a flat plate element with a shoulder that has a side surface connected to the sheave surface only on the side surface,
By making the pulley groove angle between the input pulleys smaller than the angle formed by the shoulder side surfaces of the shoulder plate element, the pulley thrust acting on the shoulder side surfaces of the shoulder plate element is on the pulley outer peripheral side. by configuring so as to increase toward, the distance from the pulley axis to effect the center of the pulley thrust, it is characterized in that the distance to the rocking edge from the pulley axis is positioned to be equal .
[0011]
Belt type continuously variable transmission according to the second invention, in the first invention, the pulley groove angle between the output pulley is made smaller than the angle both shoulders sides of the plate element with said shoulder forms the shoulder By configuring the pulley thrust acting on both shoulder sides of the flat plate element to increase toward the outer periphery of the pulley, the distance from the pulley axis to the center of action of the pulley thrust, and from the pulley axis to the locking edge It is characterized by being positioned so that the distance is equal .
[0013]
The belt type continuously variable transmission according to a third aspect of the present invention is the belt-type continuously variable transmission according to the first or second aspect, wherein a difference between an angle formed by both shoulder side surfaces of the shouldered flat plate element and the pulley groove angle is 0.16 to 0.24. (°) is set in the range.
[0014]
【The invention's effect】
The basic configuration of the present invention, the distance from the pulley axis of the working center of the pulley thrust against the flat element, in Rukoto is positioned to be approximately equal to the distance to the rocking edge from the pulley axis. According to this configuration, a moment that tilts the flat plate element backward does not occur around the rocking edge.
[0015]
Further, in this case, the side surface of the flat plate element facing the sheave surface does not locally contact the sheave surface of the pulley, but the entire side surface contacts the sheave surface of the pulley, and a part of the side surface of the flat plate element is extremely worn. As a result, the coefficient of friction against the sheave surface does not decrease. Therefore, according to the said structure , the frictional force which acts on the side surface of the said flat plate element can be transmitted reliably, and the transmission torque capacity of a belt type continuously variable transmission can be improved.
[0016]
By the way, as an example of the flat plate element, there is a shape that comes into contact with the sheave surface only on the side surface that faces the sheave surface and that is continuous with the shoulder portion on which the endless band is spanned. Therefore, the belt type continuously variable transmission according to the first invention, the flat element adopts a plate element with said shoulder, the pulley groove angle between the input pulley, than the angle formed by both shoulders sides of the plate element with said shoulder By reducing the pulley thrust force acting on both shoulder side surfaces of the shoulder plate element, the pulley thrust force acts on the input pulley side plate element from the pulley axis line by increasing the pulley thrust force toward the pulley outer peripheral side. the distance of the distance from the center, positioned such that the distance to the rocking edge from the pulley axis are equal.
[0017]
In this case, since a moment that tilts the flat plate element backward is hardly generated around the rocking edge, the side surface of the flat plate element connected to the shoulder portion over which the endless band is spanned does not locally contact the sheave surface of the pulley. The entire side face of the shoulder is in contact with the sheave face of the pulley, and a portion of the side face of the shoulder portion of the input pulley side flat plate element is not extremely worn, so that the coefficient of friction with respect to the sheave face does not decrease.
[0018]
Therefore, according to the first invention, the frictional force acting on the side surface of the flat element to reliably transmitted, it is possible to improve the transmission torque capacity of the belt type continuously variable transmission.
[0019]
Belt type continuously variable transmission according to the second invention, in the flat element with the shoulder, the pulley groove angle between the output pulley is made smaller than the angle formed by both shoulders sides of the plate element with said shoulder, said shoulder by pulley thrust acting on both shoulders sides biasing flat element is configured so as to increase toward the pulley outer periphery, the distance from the pulley axis to effect the center of the pulley thrust to said output pulley side flat plate element, wherein Position so that the distance from the pulley axis to the locking edge is equal.
[0020]
In this case, the moment that causes the flat plate element to tilt backward hardly occurs around the rocking edge. Therefore, the shoulder side surface of the flat plate element on the output pulley side does not contact the sheave surface of the pulley and the entire side surface of the shoulder portion. The friction coefficient with respect to the sheave surface is not lowered by contact with the sheave surface of the pulley and a part of the shoulder side surface of the output pulley side flat plate element being extremely worn.
[0021]
Therefore, according to the second invention, the frictional force acting on the side surface of the flat element to reliably transmitted, it is possible to further enhance the transmission torque capacity of the belt type continuously variable transmission.
[0023]
As in the belt-type continuously variable transmission according to the third aspect of the invention, the difference between the angle formed by the shoulder side surfaces of the shouldered flat plate element and the pulley groove angle is in the range of 0.16-0.24 (°). If set to, the effects described in the first and second inventions can be obtained most efficiently.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a front view showing an embodiment of a belt-type continuously variable transmission according to the present invention, in which a pulley (hereinafter referred to as a fixed pulley) 4 fixed to a rotating shaft 8 and the rotating shaft 8 are arranged in an axial direction. A pulley formed by a movable pulley (hereinafter referred to as a movable pulley) 5 is a pulley to which engine rotation is input (hereinafter referred to as an input pulley), and the rotation of the input pulley is changed via the transmission belt 1. An output pulley (hereinafter referred to as an output pulley) is configured.
[0025]
FIG. 2 is a side view of FIG. 1 in which an endless band 3 to be described later is omitted. As shown in FIGS. 1 and 2, the transmission belt 1 includes a plurality of flat plate elements 2 arranged without gaps, and a pair of endless bands 3 are stretched over the flat plate element row, and the flat plate elements 2 are rocking edges. 6 is wound around a pair of input pulleys and output pulleys constituted by the fixed and movable pulleys 4 and 5.
[0026]
3 and 4 are a front view and a side view for explaining the moment M1 for tilting the flat plate element 2 backward. First, the operation of the belt type continuously variable transmission will be described. The frictional force F along the rotational direction of the pulley is generated by the pulley thrust N acting on the flat plate element 2 between the fixed pulley sheave surface 4f and the movable pulley sheave surface 5f. At this time, the frictional force F is generated at the acting center C2 (pulley thrust Nc) of the pulley thrust N, whereby torque is transmitted from the input pulley to the flat plate element 2 and an output is given to the output pulley via the transmission belt 1.
[0027]
By the way, considering the state in which torque is transmitted from the pulley to the flat plate element 2-1, and a compressive force is generated between the flat plate element 2-1 and the flat plate element 2-2, this state is the pulley thrust of the flat plate element 2. It can be considered that the frictional force F acts on the action center C2 along the sheave surface.
[0028]
Since the transmission belt 1 is wound between the input and output pulleys when the flat plate element 2 is tilted around the locking edge 6, a predetermined interval is generated between the action center C 2 of the pulley thrust N and the locking edge 6. As a result, a moment M1 for tilting the flat plate element 2 backward is generated.
[0029]
In this case, the side surface 2f of the flat plate element 2-1 comes into contact with the sheave surfaces 4f and 5f, and the friction coefficient with respect to the sheave surfaces 4f and 5f may decrease due to a part of the flat plate element side surface 2f being extremely worn. Therefore, there is room capable of improving the transmission torque capacity.
[0030]
Therefore, in the present invention, as a basic configuration, in order to prevent a moment that tilts the flat plate element 2 backward from occurring around the rocking edge 6, the pulley thrust N acting on the flat plate element 2 from the pulley axis O of the acting center C2 is applied. The distance Lc is positioned to be equal to the distance L6 from the pulley axis O to the rocking edge 6.
[0031]
In the above embodiment, as an example of a flat plate element, as shown in FIG. 1, a side surface that is continuous with a shoulder portion 2 s over which a pair of endless bands 3 are spanned, among the side surfaces facing the fixed sheave surface 4 f and the movable sheave surface 5 f. sheave surface 4f only in the side surface 2s f has 2SF, employs a flat element of the shape in contact with 5f.
[0032]
Therefore, in the above-described embodiment, the pulley groove angle α between the input pulleys is made smaller than the angle β formed by both shoulder side surfaces 2sf of the element 2, as shown in FIG. By configuring the pulley thrust 2s f acting on the pulley to increase toward the pulley outer peripheral side, the distance Lc from the pulley axis O to the pulley thrust acting center C2 with respect to the input pulley side flat plate element 2 is determined as the pulley axis O. Is positioned so as to be equal to the distance L6 from the to the locking edge 6.
[0033]
In this case, the moment M1 that causes the flat plate element 2 to tilt backward is smaller than the moment M2 (see FIG. 9) generated by the prior art and hardly occurs around the rocking edge 6, so that the endless band 3 is spanned. The side surface 2sf of the flat plate element 2 connected to the shoulder portion 2s does not come into contact with the pulley sheave surfaces 4f and 5f locally, but comes into contact with the pulley sheave surfaces 4f and 5f as a whole, and the shoulder side surface 2sf of the input pulley side flat plate element. The friction coefficient with respect to the sheave surfaces 4f and 5f is not lowered by a part of the surface being extremely worn.
[0034]
Therefore, according to the above configuration, the frictional force F acting on the shoulder side surface 2sf of the flat plate element 2 can be reliably transmitted, and the transmission torque capacity of the belt type continuously variable transmission can be improved.
[0035]
In another embodiment, it is preferable to set not only the angle on the input pulley side but also the angle on the output pulley side. In this embodiment, the pulley groove angle α between the output pulleys is configured to be smaller than the angle β formed by the shoulder side surfaces 2sf of the flat plate element 2, so that the pulley thrust force on the output pulley side flat plate element 2 can be reduced. The distance Lc from the pulley axis O of the action center C2 is positioned so as to be equal to the distance L6 from the pulley axis O to the rocking edge 6.
[0036]
In this case, the moment M1 that causes the flat plate element 2 to tilt backward hardly occurs around the rocking edge 6. Therefore, the shoulder side surface 2sf of the flat plate element 2 on the output pulley side contacts the sheave surfaces 4f and 5f, and the output pulley side. The friction coefficient with respect to the sheave surfaces 4f and 5f does not decrease due to extreme wear of a portion of the shoulder side surface 2sf of the flat plate element 2.
[0037]
Therefore, according to the above embodiment, the frictional force F acting on the shoulder side surface 2sf of the flat plate element 2 can be reliably transmitted, and the transmission torque capacity of the belt type continuously variable transmission can be further improved.
[0038]
FIG. 5 shows the relative relationship between the angle α formed by the fixed pulley sheave surface 4f and the movable pulley sheave surface 5f and the angle β formed by the shoulder side surface 2sf of the flat plate element 2 in the belt type continuously variable transmission according to the present invention under predetermined operating conditions. The result of experimentally measuring the slip limit torque (maximum transmission torque) using the angle as a parameter is shown, and the slip limit torque when β-α = 0 corresponding to the conventional example is arranged as 1. At this time, the angle β is a constant value βo = 11.0 (°) of the conventional product.
[0039]
From the above experimental results, it can be seen that if the value of β-α is set in the range of 0 (°) to 0.40 (°), it is possible to transmit torque higher than that of the conventional example. It can also be seen that if the value of β-α is set in the range of 0.16 (°) to 0.24 (°), the transmission torque capacity can be increased by about 20%.
[0040]
Therefore, if the difference between the angle β formed by the shoulder side surfaces 2sf and 2sf of the flat plate element and the pulley groove angle α is set in the range of 0 to 0.40 (°), the operational effects described in the above embodiments. Can be obtained efficiently.
[0041]
If the difference between the angle β formed by the shoulder side surfaces 2sf and 2sf of the shoulder plate element and the pulley groove angle α is set in the range of 0.16 to 0.24 (°), each of the above-described implementations. The effects described in the embodiments can be obtained most efficiently.
[0042]
As is apparent from the above description, the belt-type continuously variable transmission according to the present invention has a distance Lc from the pulley axis O of the center C2 of the pulley thrust Nc to the flat plate element 2 from the pulley axis O to the rocking edge 6. As a result, the moment M that causes the flat plate element 2 to tilt backward does not occur around the rocking edge 6.
[0043]
In this case, the side surface 2s of the flat plate element 2 opposed to the sheave surfaces 4f and 5f does not contact the sheave surfaces 4f and 5f of the pulley, but comes into contact with the sheave surfaces 4f and 5f of the pulley throughout the side surface 2s. The friction coefficient with respect to the sheave surfaces 4f and 5f is not reduced by a part of the side surface 2s being extremely worn. Therefore, according to the said invention, the frictional force F which acts on the side surface 2s of a flat plate element can be transmitted reliably, and the transmission torque capacity of a belt type continuously variable transmission can be improved.
[0044]
The above description is only a preferred embodiment of the present invention, and various modifications can be made within the scope of the claims by those skilled in the art. Although there is an endless laminated band in which terminal-shaped bands are laminated, the endless band may be a single body.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a front view partially showing a cross section of an embodiment of a belt type continuously variable transmission according to the present invention.
FIG. 2 is a side view of FIG.
FIG. 3 is a front view of a flat plate element for explaining a moment M1 generated by the present invention.
4 is a side view of FIG. 3. FIG.
FIG. 5 is an experimental measurement diagram of slip limit torque using a relative angle between a pulley groove angle α and an angle β formed by a shoulder side surface of a flat plate element as a parameter in a belt type continuously variable transmission according to the present invention under predetermined operating conditions. It is.
FIG. 6 is a front view illustrating a conventional belt type continuously variable transmission with a partial cross section.
7 is a side view of FIG. 6. FIG.
8 is a front view of a flat plate element for explaining a moment M2 generated by the prior art. FIG. 9 is a side view of FIG.
[Explanation of symbols]
1 Transmission belt (present invention)
2 Flat element (present invention)
2s Shoulder 2sf Shoulder side C2 Pulley thrust center 3 Endless band 4 Fixed pulley 4f Sheave surface (fixed pulley)
5 Movable pulley 5f Sheave surface (movable pulley)
6 Rocking edge 8 Rotating shaft
10 Transmission belt (conventional)
20 Flat element (conventional)

Claims (3)

A plurality of flat plate elements are arranged without gaps, and a transmission belt, in which an endless band is stretched over this flat plate element row, is wound between input and output pulleys by tilting the flat plate elements around a locking edge. In the belt type continuously variable transmission,
The flat plate element is configured as a flat plate element with a shoulder having a side surface continuous with a shoulder portion over which an endless band is spanned and contacting the sheave surface only with the side surface,
By making the pulley groove angle between the input pulleys smaller than the angle formed by the shoulder side surfaces of the shoulder plate element, the pulley thrust acting on the shoulder side surfaces of the shoulder plate element is on the pulley outer peripheral side. By configuring it to become larger as you go,
The distance from the pulley axis to effect the center of the pulley thrust, a belt type continuously variable transmission, characterized in that the distance to the rocking edge from the pulley axis is positioned to be equal. The pulley groove angle between the output pulley is made smaller than the angle both shoulders sides of the plate element with said shoulder forms, the pulley thrust pulley outer periphery which acts on both shoulders sides of the plate element with said shoulder by configuring so as to increase toward, the distance from the pulley axis to effect the center of the pulley thrust, that the distance to the rocking edge from the pulley axis is positioned to be equal to claim 1, wherein The belt type continuously variable transmission described. Wherein the difference between the angle and the pulley groove angle which both shoulders sides forms a flat element with said shoulder, to claim 1 or 2, characterized in that set in the range of 0.16-0.24 (°) Belt type continuously variable transmission.

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