JPH01169150A - Transmission belt - Google Patents

Abstract

PURPOSE:To reduce the noise level of a transmission belt by providing the cylindrical face of a rolling member of a rocker-joint pin to connect many link plates in order with two or more kinds of radii of curvature which are established between the maximum and the minimum radius of curvature to satisfy a specified equation. CONSTITUTION:Many link plates 2 are mutually connected in order through a rocker- joint pin 1, and many V-shaped blocks frictionally engaged with the V-groove of a pulley are provided in line in the longitudinal direction of endless link connecting bodies 3, 4 of the link plate 2. The rocker-joint pin 1 consists of a pair of rolling members 1a, 1b which can roll as they come into contact with each other on a cylindrical face having the same radius of curvature, and the cylindrical face of the rolling member is provided with two or more kinds of the radii of curvature r1-r3, which are selected to have a value found between the maximum and the minimum radius of curvature in which the equation 1 is satisfied by a half sheave angle gamma of the V- groove of the pulley, the maximum distance Rmax from a contact between the rolling members to the rotational center of the pulley in a state of the stretched belt, alpha= Sin<-1>(P0/2Rmax), and a pitch P0 between the rocker-joint pins. Thus the noise level of a transmission belt can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a power transmission belt that is used by being passed between two groove pulleys of a continuously variable transmission.

(Prior art) Conventionally, this kind of power transmission belt is
As described in Publication No. 38, an endless link connection is constructed by sequentially connecting a large number of link plates with a rocker joint pin consisting of a pair of rolling members that can roll in contact with each other on a cylindrical surface with the same radius of curvature. There is a known type in which a body is provided with a number of V-shaped blocks sequentially arranged in the longitudinal direction and frictionally engaged with the pulley groove.

However, in a power transmission belt with such a configuration, since the cylindrical surfaces of the rolling members of the rocker joint pins are the same between the rocker joint pins, when the power transmission belt is wound around the V-groove pulley, a specific frequency (belt mesh primary frequency) noise level increases.

Therefore, the applicant of this application previously filed Utility Application No. 1983-92838.
We have developed a technology that uses two or more types of rocker joint pins that have different radii of curvature on the cylindrical surface of the rolling member, thereby preventing noise levels from increasing at specific frequencies. It has already been proposed.

(Problem to be Solved by the Invention) However, in this proposed technique, the maximum and minimum values of the radius of curvature of the cylindrical surface of the rolling member are not defined, so the problem may vary depending on the selection of the radius of curvature. It was confirmed that the noise level was high at the primary frequency of belt meshing. It was also confirmed that the torque fluctuation became large just before the continuously variable transmission stopped, causing jerky vibrations.

(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 pulley winding radius caused by the difference in the radius of curvature of the cylindrical surface of the rolling member. The radius of curvature of the cylindrical surface of the member is set to a value that does not cause the above problem, and a large number of link plates are connected by a rocker joint pin consisting of a pair of rolling members that can roll in contact with each other on the cylindrical surface of the same radius of curvature. The endless link connection body is provided with a number of V-shaped blocks sequentially arranged in the longitudinal direction and frictionally engaged with the pulley V groove, and the rocker joint pin In a power transmission belt in which two or more types of radii of curvature are set on the cylindrical surface of the rolling member, the radius of curvature is defined as the maximum radius of curvature r + *mx that satisfies 0.08/2 tan r≦ ≦0.13/2 tan 7 The selected configuration is characterized by a minimum radius of curvature r+aiy+.

(Function) ■During the actual use of the transmission belt hanging on the grooved pulley, ■the grooved pulley frictionally engages with it, and the ■shape block transfers power between the ■shape block and the endless link connection body. Power is transferred between the two to enable predetermined power transmission.

However, since two or more radii of curvature are set on the cylindrical surface of the rolling member of the rocker joint pin, and these radii of curvature are selected to values between rsax + reia defined by the above formula, the transmission belt does not fit into the V-groove. Wrapping it around the pulley can prevent the noise level from becoming high at a certain frequency or the torque fluctuations becoming large just before stopping, which can prevent the occurrence of jerky vibrations.

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

FIG. 1 shows an embodiment of the power transmission belt of the present invention, in which (a) is a cutaway plan view of the main part, (b) is a longitudinal sectional front view, and (c) is a longitudinal sectional side view of the main part.

In these figures, 1 is a large number of rocker joint pins, each rocker joint pin is composed of a pair of rolling members 1a, lb, and each pair of rolling members is connected to each other with cylindrical surfaces of the same radius of curvature touching each other. It is possible to roll. Therefore, the radius of curvature of the cylindrical surface of the rolling member between the rocker joint pins is rI+ r2+
Three different types of rocker joint pins are prepared as shown by r3, and a large number of link plates 2 are interconnected by these three types of rocker joint pins to form an endless link connection body 3.4.

The three types of rocker joint pins are arranged in random order, but the arrangement order is the same between link connectors 3 and 4. Then, the two link connecting bodies 3.4 are arranged at a pitch P such that the same type of rocker joint pins are adjacent to each other.
They are arranged side by side, offset by a half of 0, and each rocker joint pin of each link assembly is inserted between the pins of the other link assembly.

At this time, if there is a gap between the ends of the pins 1 that have entered each other, this gap is filled with a bush 5 (only one is shown for convenience in the drawing), so that the relative position of the link connectors 3 and 4 in the longitudinal direction remains unchanged. so that it is maintained.

A V-shaped block 6, which collectively and laterally surrounds these link bodies 3.4, is provided so as to be slidable in the longitudinal direction of the link bodies 3.4. For this purpose, a protrusion 6b is provided between the windows 68 formed in each V-shaped block 6, thereby keeping the relative positions of the link bodies 3, 4 in the axial direction of the bottle (1) unchanged.

In assembling the above-mentioned power transmission belt, the link connecting bodies 3.4 are assembled immediately before they are made into an endless state, and these link connecting bodies 3.4 are arranged side by side.

The window 6a of the ■-shaped block 6 is fitted into the link connecting bodies 3.4 juxtaposed in this manner, and the ■-shaped block 6 is sequentially assembled.

When the last ■-shaped block is fitted, the last bottle 1 is inserted through the pin insertion hole (not shown) provided in the last ■-shaped block, and the link connecting bodies 3 and 4 are made into an endless shape. Complete the transmission belt assembly.

In practical use, as shown in FIG. 1(b), the square block 6 is wound around the pulley groove 7, and the transmission belt is passed between the V-groove bobbles. At this time, the power of the driving pulley is transferred from the V-shaped block 6 that is frictionally engaged with the groove of the link connecting body 3.
, 4, and frictionally engaged with the V groove of the driven pulley.■
The pulley is reached through the shaped block 6, and power can be transferred between the two pulleys.

And the rolling member 1a of the rocker joint pin 1.

The radii of curvature rl+r2+r3 of the cylindrical surface at 1b are determined as follows.

First, referring to FIG. 2, which is shown as an x-y coordinate system, the pulley running radius R of the rocker joint pin 1 when the radius of curvature of the cylindrical surface of the rolling member is r (pulley rotation from the contact point B1 of the rolling members 1a and lb) (distance to center 0).

In FIG. 2, link plate 2a is a link that is completely wrapped around the pulley, link plate 2b is a link plate that is beginning to be wrapped, and link plate 2c is a link plate that is not wrapped. FIG. 3 also shows the rocker joint pin between the link plates 2a and 2b enlarged in the x-y coordinate system.

β is the intersection angle between the link plates 2a and 2b (the angle formed by the link plate center lines), and point At is the rolling member 1a when the center lines of the link plates 2a and 2b form a straight line.

The contact point of lb, point B1 is the rolling member 1a when the intersection angle is β, the contact point of lb, point 01 is the center point of the radius of curvature of the rolling member 1a, point CI is the point B, and a line segment 0. - The leg of the perpendicular drawn to A, Ro is the distance between point 0 and point A.

Here, Q A, = (Re ・sin θ, R,, ・co
s θ), then the pulley winding radius R of rocker joint pin 1 (=O
Bυ is −l (R6・sin θ, Ro・cos θ)+(r
+(cos (β/2)-1), 0)+ (0+ r+
-5in(β/2)1=l(Re ・5ine+r
+(cos(β/2)−1).

1.・cos o ft -5in (β/2))
It becomes 1.

Here, as can be seen from Figure 4, the relationship between β and θ is as follows: β + (π/2 + θ) + (π/2 - α) = π, °, β = α
−θ. However, a wsin-' (Po/2Ro) (P,: pitch) By the way, when the winding is completely completed, θ=-α, β-
2α, the pulley running radius R of the rocker joint pin is as follows. Next, in FIG. 1(c), 11 < r z
If <r3, then the pulley running radius difference ΔR of the rocker joint pin due to the difference between the maximum radius of curvature r3 and the minimum radius of curvature r of the cylindrical surface of the rolling member is expressed as...-(1).

On the other hand, the rocker joint pin pulley running radius difference ΔR due to the difference ΔW in the V-shaped block width is ΔR=ΔW/2 ta
It is expressed as n r - (2) (T: half-sheep angle of pulley groove).

In equation (1), ΔR is the difference between rl and rl, Δr==r,
The larger -r is, and the smaller R0 is, the larger it becomes.Furthermore, in equation (2), -R is in a proportional relationship with ΔW, so Δ
The relationship shown in FIG. 5 holds between r and ΔW, with Ro as a parameter. In Fig. 5, RO”Ra1n indicates the relationship when the pulley running radius of the Rockersillion Indian pin is the minimum value in the speed change range of the continuously variable transmission, and R, = R□8 indicates the pulley running radius of the Rockersillion Indian pin. The relationship when the radius is the maximum value in the speed change range of the continuously variable transmission is shown.

By the way, for every difference ΔW in the V-shaped block width, the belt meshing is 1
When the vibration level L and the torque fluctuation amount T of the next frequency were determined through experiments, it was confirmed that they each changed with the trends shown in FIG. 6. Further, the perceptually acceptable noise level and torque fluctuation level are L t and T + respectively, and from this, the noise level and the torque fluctuation level are L t and T + respectively.

It was confirmed that in order to suppress both torque fluctuations within the allowable range, the difference ΔW between the V-shaped block widths should be within the range of 0.08 to 0.13 am.

From this, the curvature radius difference Δr of the cylindrical surface of the rolling member that satisfies both noise level and torque fluctuation is found to be within the range shown by X in Figure 7, which is a transposition of Figures 5 and 6. I understand. However, torque fluctuations become a problem just before the continuously variable transmission stops, that is, when the gear ratio is at its lowest speed ratio and the diameter of the belt wrapped around the output side V-groove pulley is at its maximum. , Δ that satisfies both noise level and torque fluctuation.
The range of r is actually as shown by Y in FIG.

Expressing this range using formulas, from formulas (1) and (2), 0.08/2 tan 1≦≦0.13/2 tan r −(3)
The radius of curvature of the cylindrical surface of the rolling member rl+r! is the value between r3+rt that satisfies this equation. By determining +r=, it is possible to suppress both the noise level and the torque fluctuation to an acceptable level.

Therefore, in this example, T=11°, P0=7.
82am, Lag = 81mm as an example, r
1=5peng, r=8 mm, r==10 mm. As a result, both the torque and the torque fluctuation in equation (3) can be suppressed within the allowable range. Also, when r, = 5 mm is substituted into equation (3), 9.
26≦r3≦ratio 93, and from this, r, = 10
It can be seen that by setting the value to mm, the noise level and torque fluctuation can be suppressed within the permissible range.

(Effects of the Invention) The power transmission belt of the present invention has a radius of curvature between the maximum radius of curvature and the minimum radius of curvature determined as described above for the cylindrical surface of the rolling member constituting the rocker joint pin. It is possible to prevent the noise level from becoming high at a specific frequency when the belt is wound around the V-groove pulley, and it is also possible to prevent the occurrence of jerky vibrations due to large torque fluctuations just before stopping.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the power transmission belt of the present invention, and FIG.
) is a cutaway plan view of the main part, (b) is a longitudinal front view, and (c) is a longitudinal front view.
2 and 3 are schematic diagrams of the rocker joint pin, respectively. Figure 4 is a schematic diagram showing the state of the transmission belt wrapped around the pulley. Figure 5 is the curvature of the cylindrical surface of the rolling member. Figure 6 is a diagram showing the relationship between the radius difference and the difference in ■-shaped block width. Figure 6 is a diagram showing the relationship between the difference in V-shaped block width and the noise level and torque fluctuation amount of the belt mesh primary frequency. Figure 7 is a region diagram showing the range of the difference in the radius of curvature of the cylindrical surface of the rolling member that satisfies the noise level and torque fluctuation. l...Rocker joint pin la, lb...Rolling member 2...Link plate 3.4...Endless link connection body 6...■Shaped block 7...Pulley ■Groove Patent applicant Nissan Motor Co., Ltd. Δr=r3−r. Figure 6

Claims (1)

[Claims] 1. An endless link connection body constructed by sequentially connecting a number of link plates with a rocker joint pin, which is a pair of rolling members that can roll in contact with each other on a cylindrical surface with the same radius of curvature. This endless link connection body is provided with a number of V-shaped blocks that are sequentially arranged in the longitudinal direction and frictionally engage with the pulley V groove, and two or more types of curvature radius are provided on the cylindrical surface of the rolling member of the rocker joint pin. For the set transmission belt, the radius of curvature is ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (r: Half sheave angle of the pulley V groove R_m_a_x: Connects the rolling member contact point and the pulley rotation center when the belt is in a straight line state. Maximum length of line segment (length when belt pulley winding radius is maximum) α: sin^-^1 (P_0/2R_m_a_x) P_
0: A power transmission belt characterized in that the value is selected between a maximum radius of curvature r_m_a_x and a minimum radius of curvature r_m_i_n that satisfy the pitch between rocker joint pins.