JP2562160B2 - Transmission belt - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a transmission belt that is used by being stretched between V-groove pulleys of a continuously variable transmission.

(Prior Art) Conventionally, as a transmission belt of this type, as described in Japanese Patent Laid-Open No. 59-200838, a rocker joint composed of a pair of rolling members capable of rolling in contact with each other on cylindrical surfaces having the same radius of curvature. A model in which an endless link connecting body constituted by connecting a large number of link plates one after another by a pin is provided, and a plurality of V-shaped blocks which are sequentially arranged in the longitudinal direction thereof and frictionally engage with the pulley V groove are provided. It has been known.

However, in the transmission belt having such a structure, the rolling member cylindrical surface of the rocker joint pin is the same between the rocker joint pins, so that when the transmission belt is wound around the V-groove pulley, a specific frequency (belt meshing primary frequency) The noise level will be high.

Therefore, the applicant of the present application previously filed Japanese Utility Model Application No. 62-92838,
We have previously proposed a technology aiming at preventing noise levels from increasing at a specific frequency by using two or more types of rocker joint pins with different radii of curvature of the rolling member cylindrical surface between the rocker joint pins. is there.

(Problems to be Solved by the Invention) By the way, in this proposed technique, the maximum value and the minimum value of the radius of curvature of the cylindrical surface of the rolling member are not specified,
It was confirmed that the noise level increased at a certain belt meshing primary frequency depending on the selection of the radius of curvature.
Moreover, it was confirmed that the fluctuation of the torque became large just before the stop of the continuously variable transmission, and the rattling vibration occurred.

(Means for Solving the Problems) The present invention is based on the fact that all of these problems occur in accordance with the difference in the radius of curvature of the rolling member, which is caused by the difference in the radius of curvature of the cylindrical surface. It defines the radius of curvature of the cylindrical surface of the member to a value that does not cause the above problem. It consists of a pair of rolling members, and these rolling members make contact with each other on cylindrical surfaces of the same radius of curvature. With the rocker joint pin, an endless link connecting body formed by connecting a number of link plates sequentially is provided, and a plurality of Vs frictionally engaged with the pulley V groove by sequentially arranging the endless link connecting body in the longitudinal direction. In a transmission belt using two or more types of rocker joint pins, the rocker joint pins are provided with a shaped block, and the radius of curvature of the rolling member cylindrical surface is different between the rocker joint pins. Each radius of curvature of the different rolling members cylindrical surface between Intopin, To a value between the maximum radius of curvature r _max and the minimum radius of curvature r _min that satisfies

(Operation) During practical use of the transmission belt hung on the V-groove pulley, the V-groove pulley transfers power to and from the V-shaped block that frictionally engages with the V-shaped pulley. Power is transferred between the two to enable predetermined power transmission.

However, 2 on the cylindrical surface of the rocker joint pin rolling member.
Since more than one kind of radius of curvature is set and these radii of curvature are selected as values between r _max and r _min defined by the above formula, when the transmission belt is wound around the V groove pulley, the noise level is high at a specific frequency. It is possible to prevent the occurrence of jerky vibration due to a large torque fluctuation immediately before the stop.

(Examples) Hereinafter, the present invention will be described in detail based on illustrated examples.

FIG. 1 shows an embodiment of the power transmission belt of the present invention.
Shows a cutaway plan view of essential parts, (b) shows a front view in vertical section, and (c) shows a side view in vertical section.

In these figures, reference numeral 1 denotes a number of rocker joint pins, each rocker joint pin comprising a pair of rolling members 1a, 1b,
The rolling members of each pair contact cylindrical surfaces having the same radius of curvature with each other so that they can roll with each other. Therefore, three types of rocker joint pins are prepared so that the radius of curvature of the rolling member cylindrical surface is different between the rocker joint pins as shown by r ₁ , r ₂ and r ₃ , and a large number of these three types of rocker joint pins are used. The link plates 2 are connected to each other to form endless link connection bodies 3 and 4.

The three rocker joint pins have a random arrangement order, but the link connection bodies 3 and 4 have the same arrangement order. Then, the two link connecting bodies 3 and 4 are juxtaposed by being displaced by the radius of the pin arrangement pitch P ₀ so that the rocker joint pins of the same type are adjacent to each other, and each rocker joint pin of each link connecting body is connected to the other link connecting body. In between the pins. At this time, if there is a gap between the ends of the pins 1 that have entered each other, the gap 5 is filled with the bush 5 (only one is shown in the drawing for convenience) so that the relative positions in the longitudinal direction of the link coupling bodies 3 and 4 do not change. To be kept at.

A V-shaped block 6 which encloses the link connecting bodies 3 and 4 together in the lateral direction is sequentially provided slidably in the longitudinal direction of the link connecting bodies 3 and 4. Therefore, a protrusion 6b is provided between the windows 6a formed in each V-shaped block 6 to keep the relative position of the link connectors 3 and 4 in the axial direction of the pin (1) unchanged.

In assembling the above-mentioned transmission belt, the link connecting bodies 3 and 4 are assembled until just before the endless shape, and the link connecting bodies 3 and 4 are juxtaposed. The window 6a of the V-shaped block 6 is fitted into the link connection bodies 3 and 4 arranged side by side in this way, and the V-shaped block 6 is assembled in sequence. Then, when the final V-shaped block is fitted, the link connecting bodies 3 and 4 are made into an endless shape while inserting the final pin 1 through the pin insertion hole (not shown) provided in the final V-shaped block. Complete the assembly of the power transmission belt.

In practical use, as shown in FIG. 1 (b), the V-shaped block 6 is wound around the pulley V groove 7 and the transmission belt is stretched between the V groove pulleys. At this time, the power of the driving pulley is changed from the V-shaped block 6 frictionally engaged with the V groove to the link connecting body.
V that has reached 3 and 4 and is frictionally engaged with the V groove of the driven pulley
It is possible to reach the pulley through the shaped block 6 and transfer power between the both pulleys.

Then, the radii of curvature r ₁ , r ₂ , r ₃ of the cylindrical surfaces of the rolling members 1a, 1b of the rocker joint pin 1 are determined as follows, respectively.

First, referring to FIG. 2 shown as an xy coordinate system, when the radius of curvature of the cylindrical surface of the rolling member is r ₁ , the pulley running radius R of the rocker joint pin 1 (from the contact point B ₁ of the rolling members 1a and 1b to the pulley rotation). Find the distance to the center 0).

In FIG. 2, the link plate 2a is a link that is completely wound around the pulley, the link plate 2b is a link plate that has started winding, and the link plate 2c is a link plate that is not wound. Fig. 3 shows the link plates 2a, 2
The rocker joint pin between b is expanded and shown to an xy coordinate system.

β is the angle of intersection between the link plates 2a and 2b (the angle formed by the link plate center lines), and point A ₁ is the rolling member 1a when the center lines of the link plates 2a and 2b are one straight line, 1b the contact point B ₁ represents rolling element 1a when the crossing angle beta, contacts 1b, the point 0 ₁ is the radius of curvature of the center point of the rolling member 1a, the line segment O ₁ point O ₁ from the point B ₁ -A ₁ is a perpendicular foot, R ₀ is the distance between point 0 and point A ₁ .

here, Then, the radius R (= 0 B ₁ ) of the rocker joint pin 1 around the pulley is Becomes

Here, the relationship between β and θ is β + (π / 2 + θ) + (π / 2−α) = π∴β = α−θ, as can be seen from FIG. However, α = sin ^-1 (P ₀ / 2R ₀ ) (P ₀ : pitch) By the way, when winding is completely completed, θ = -α, β
= 2α, the pulley running radius R of the rocker joint pin is Becomes Next, when r ₁ <r ₂ <r ₃ in FIG. 1C, the maximum radius of curvature r ₃ and the minimum radius of curvature r _{1 of the} rolling member cylindrical surface are set.
The difference in the pulley running radius of the rocker joint pin ΔR is Is represented by

On the other hand, the pulley running radius difference ΔR of the rocker joint pin due to the V-shaped block width difference ΔW is represented by ΔR = ΔW / 2tan γ (2) (γ: half sheave angle of pulley V groove).

(1) as ΔR is larger difference [Delta] r = r ₃ -r ₁ between r _3, r ₁ in the expression, also increases as R ₀ is small, and (2) because ΔR is proportional to ΔW in formula , Δr and ΔW satisfy the relationship shown in FIG. 5 with R ₀ as a parameter. In Fig. 5, R ₀ = R _min shows the relationship when the pulley running radius of the rocker joint pin is the minimum value in the gear shift range of the continuously variable transmission, and R ₀ = R _max is the pulley running radius of the rocker joint pin. Shows the relationship when is the maximum value in the shift range of the continuously variable transmission.

By the way, when the vibration level L of the belt meshing primary frequency and the torque fluctuation amount T were obtained by an experiment for each difference ΔW of the V-shaped block width, it was confirmed that the vibration level L and the torque fluctuation amount T change with the tendency as shown in FIG. 6, respectively. Also, the noise level and the torque fluctuation level which are permissible perceptually are L ₁ and T ₁ , respectively. Therefore, in order to suppress both the noise level and the torque fluctuation within the permissible range, the V-shaped block width difference ΔW is 0.08. It was confirmed that it should be within the range of 0.13 mm.

From this, it is understood that the curvature radius difference Δr of the cylindrical surface of the rolling member that satisfies both the noise level and the torque fluctuation is in the range indicated by X in FIG. 7 which is a transfer of FIGS. 5 and 6. . The torque fluctuation becomes a problem immediately before the stop of the continuously variable transmission, that is, when the gear ratio is the minimum speed ratio and the belt winding diameter of the output side V-groove pulley is maximum. Δ that satisfies both noise level and torque fluctuation
The range of r is actually as shown by Y in FIG.

When this range is expressed by an equation, from equations (1) and (2) Therefore, if the radii of curvature r ₁ , r ₂ , r ₃ of the cylindrical surface of the rolling member are determined to be a value between r ₃ and r ₁ that satisfies this equation, both noise level and torque fluctuation can be suppressed to an allowable level. You can

Therefore, in this example, r = 11 °, P ₀ = 7.82 m
Taking m and R _max = 81 mm as an example, r ₁ = 5 mm, r ₂ = 8 mm, r
Determine to ₃ = 10 mm. Thus, in equation (3) Is 0.094 / 2tan γ, and both the noise level and torque fluctuation can be suppressed within the allowable range by satisfying the expression (3). When r ₁ = 5 mm is substituted into the formula (3), 9.26 ≦ r ₃
≦ 11.93, which also shows that the noise level and the torque fluctuation can be suppressed within the permissible range by setting r ₃ = 10 mm.

(Effects of the Invention) Thus, in the transmission belt of the present invention, the cylindrical surface of the rolling member constituting the rocker joint pin is set to have the radius of curvature between the maximum radius of curvature and the minimum radius of curvature determined as described above, and therefore the transmission belt is V-shaped. It is possible to prevent the noise level from becoming high at a specific frequency when wound around the grooved pulley, and to prevent the jerky vibration from occurring due to the large torque fluctuation immediately before the stop.

[Brief description of drawings]

FIG. 1 shows an embodiment of a power transmission belt of the present invention, in which FIG. 1 (a) is a plan view of a notched portion of the same, and FIG.
(C) is a longitudinal side view of a main part, FIGS. 2 and 3 are schematic diagrams of rocker joint pins, FIG. 4 is a schematic diagram showing a pulley winding state of a transmission belt, and FIG. 5 is a rolling member cylinder. FIG. 6 is a diagram showing the relationship between the difference in the radius of curvature of the surfaces and the difference in the V-shaped block width. FIG. 6 is a diagram showing the relationship between the difference in the V-shaped block width and the noise level of the belt meshing primary frequency and the torque fluctuation amount. FIG. 7 is a region diagram showing the range of the radius of curvature difference of the cylindrical surface of the rolling member that satisfies the noise level and the torque fluctuation. 1 ... Rocker joint pin 1a, 1b ... Rolling member, 2 ... Link plate 3,4 ... Endless link connection body 6 ... V-shaped block, 7 ... Pulley V groove

Claims (1)

(57) [Claims] 1. A large number of link plates are sequentially connected by a rocker joint pin which is composed of a pair of rolling members and which rolls in contact with each other on cylindrical surfaces having the same radius of curvature. And a plurality of V-shaped blocks which are sequentially arranged in the longitudinal direction and frictionally engage with the pulley V groove.
As the rocker joint pin, in the transmission belt using two or more types of rocker joint pins, the curvature radius of the rolling member cylindrical surface is different between the rocker joint pins, and the curvature of the rolling member cylindrical surface is different between the rocker joint pins. Each radius, A transmission belt having a maximum curvature radius r _max and a minimum curvature radius r _min that satisfy