JPS6372941A - Power transmission belt - Google Patents

Abstract

PURPOSE:To reduce chord oscillation, suppress the generation of noise and improve durability by forming the inside and outside edges of link plates which form the inner and outer peripheries of an endless link linking member into arc shapes along V-belt winding arcs respectively and reducing a projecting quantity. CONSTITUTION:V-blocks 6 are put around the V-groove 7 of each pulley and a power transmission belt is put around the V-groove pulleys and the power of a driving side pulley is transmitted from the blocks 6 which are frictionally joined to the V-groove to link linking members 3, 4 and, after that, arrives at a driven pulley via blocks 6 which are frictionally engaged with the V-groove of the driven side pulley, carrying out the delivery of power between both pulleys. With the two linking members 3, 4 as one set, these are placed in parallel in such a way that the positions of their respective pins 1 are shifted from each other, thereby, the arranging pitch of the pins 1 is halved from L to L/2, enabling the bending pitch of the power transmission belt put around the V-grooves 7 to be halved. Thereby, the poligonal shape of the power transmission belt with respect to pulleys is made further close to circle, causing the contacting positions of the blocks 6 with the V-groove 7 to be slightly displaced when these are wound into or delivered out of the V-groove 7, to reduce a chordal oscillation.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to (1) a power transmission belt used by being stretched between grooved pulleys.

(Prior Art) Various types of transmission belts of this kind have been known in the past, such as those shown in Japanese Patent Application Laid-Open No. 59-144843 and Japanese Utility Model Application No. 59-42345. .

This power transmission belt includes a link connection body formed by connecting a large number of adjacent pins to each other by link plates, and a series of ■-shaped blocks are provided on this link connection body so as to be slidable in the longitudinal direction. In practical use, the ■-shaped block is wrapped around the pulley's ■ groove, allowing power to be transferred between the V-groove pulleys.

However, in this configuration, the link connection is only one tree,
When a series of ■-shaped blocks are assembled to this, the distance to the pulley rotation center is different between both ends and the center of the link plate in the pulley wrapping area, and the V-shaped blocks at both ends of the link plate are connected to the Boo IJ 'V groove. As a result, the pitch of the ■-shaped block that frictionally engages with the pulley V groove is equivalent to a pin arrangement pinch. For this reason,
■The straight parts of the transmission belt between the grooved pulleys repeatedly move toward and away from each other, causing string vibrations that not only tend to generate abnormal sounds and noises, but also cause the load to concentrate on specific ■-shaped blocks. It was also disadvantageous in terms of durability.

In order to solve this problem, it is effective to reduce the pin arrangement pitch, but there is a limit to the size reduction due to the requirements for pin and link strength, so it is not possible to solve the problem. The reality was that they were not getting it.

Another way to reduce the pin arrangement pitch is to arrange multiple link connectors side by side so that the pin positions are shifted, and to assemble a common ■-shaped block to the link connectors arranged in this way. It is conceivable to reduce the arrangement pitch of the upper pins by the above-mentioned deviation.

(Problem to be Solved by the Invention) However, in this countermeasure, as shown in FIG.
and project out from each other at the pin joint portion like ΔL. Therefore, the hole of the ■-shaped block that is to be fitted into the juxtaposed link connecting bodies must be made larger by the overhang amount ΔL, and the ■-shaped block will tilt due to backlash against the link connecting bodies, and due to abnormal contact. ■It causes increased wear on the shaped block and increased pulley collision noise.

This tendency becomes more pronounced as the amount of overhang ΔL increases, but as shown in Figure 3, this amount of overhang ΔL changes the radius of the V-belt winding arc to R.
1 The pin arrangement pitch in each endless link connection body is Lp
, where θ is the phase shift angle between the endless link bodies arranged in parallel, it is expressed as follows.

Here, as described in the above-mentioned document, although the inner edge of each link plate forming the inner periphery of the endless link connection body is formed into an arc shape along the V-belt wrapping arc, each link plate forming the outer periphery of the endless link connection body Considering the case where a conventional link plate shape in which the outer edge of the link plate is a straight line or an inverted circular arc is used as a roadbed, the above-mentioned overhang amount ΔL becomes extremely large as shown by the solid line a in Fig. 4, and the above-mentioned It is undeniable that a problem will occur.

(Means for Solving the Problems) The present invention reduces the amount of overhang by making the inner and outer edges of each link plate forming the inner and outer peripheries of the endless link connection body arc-shaped along the V-belt wrapping arc. This is an attempt to solve the above problem.

(Function) When a power transmission belt is used between V-groove pulleys, the power from the driving pulley is transmitted from the ■-shaped block that is frictionally engaged with the V-groove to all the endless link connections, and then transferred to the driven side. It reaches the pulley through a V-shaped block that is frictionally engaged with the groove of the pulley, making it possible to transfer power between both pulleys.

During this time, the transmission belt wound around the pulley has a plurality of linked link bodies arranged side by side such that the pin positions are shifted, so that the actual pitch of the pin arrangement is reduced. As a result, the polygonal winding of the transmission belt around the pulley becomes close to a circle, which not only reduces string vibration and suppresses the generation of abnormal noise, but also improves durability by avoiding load concentration on a specific V-shaped block. can be improved.

In addition, when a plurality of endless link connecting bodies are arranged side by side so that the pin positions are shifted, the inner and outer edges of each link plate are shaped like an arc along the circular arc around which the transmission belt is wound.
The above-mentioned amount of overhang can be made smaller, and the rattling of the ■-shaped block can be correspondingly reduced, thereby reducing wear of the V-shaped block and pulley collision noise caused by abnormal light.

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

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

Reference numeral 1 in these figures denotes a large number of pins, and adjacent pins are interconnected by link plates 2 to form endless link connections 3 and 4. Note that each pin 1 is a well-known silent pin consisting of two parts 1a and Ib divided in the radial direction, and by making the dividing surfaces mutually inverted cylindrical surfaces, the link plate 2 is formed as shown in Fig. 1(C). Rotation is possible by rolling contact of the inverted circular divided surfaces with each other.

In this example, two 88-end link connectors 3.4 are arranged side by side so that the pins 1 are shifted from each other, and the pin 1 of each link connector is inserted between the pins 1 of the other link connector. At this time, if there is a gap between the ends of the pins l that have entered each other,
A bushing 5 (only one shown in the drawing for convenience) fills this gap so that the relative longitudinal position of the link connection 3.4 remains unchanged.

A square block 6 which laterally surrounds these link bodies 3.4 is sequentially provided so as to be slidable in the longitudinal direction of the link bodies 3.4. For this purpose, a projection 6b is provided between the windows 6d formed in each ■-shaped block 6, thereby keeping the relative position of the pin (1) of the link connection body 3.4 in the axial direction unchanged.

In assembling the above-mentioned power transmission belt, the link connecting bodies 3.4 are assembled until just before they are made into an endless state, and these link connecting bodies 3.4 are juxtaposed.

The V-shaped block 6 is sequentially assembled by fitting the ■-shaped block window 6a into the link connecting bodies 3.4 juxtaposed in this way.

After fitting the last ■-shaped block, insert the last pin 1 into the link connecting body 3 through the pin insertion hole 6c shown in FIG.
．． 4 into an endless shape to complete the transmission belt assembly. In addition, if you do not want to thicken the last ■-shaped block in which the pin insertion hole 6c is provided, as shown by the two-dot chain line in Fig. A notch 6d may be formed to constitute a pin insertion hole.

In practical use, as shown in Figure 1, the V-shaped block 6 is wound around the pulley groove 7, and the transmission belt is passed between the V-groove pulleys. At this time, the power of the driving pulley is transferred from the V-shaped block 6 frictionally connected to the groove of the link connecting body 3.
．． 4, and then reaches that pulley via the ■-shaped block 6 that is frictionally engaged with the V-groove of the driven pulley, and power can be transferred between both pulleys.

In this example, the link connecting bodies 3 and 4 are arranged as a set of two, and the pins 1 are arranged side by side with their positions shifted, so that the arrangement pitch of the pins l is changed from L to 172L as shown in FIG. 1(b). Reduced by half to Pulley V? The bending pinch of the transmission belt caught in the n7 can be halved. As a result, the shape of the polygonal shading of the transmission belt relative to the pulley becomes closer to a circle, and when the ■-shaped block 6 is wound into the pulley ■ groove 7 or when it is unwound, the contact position with the boo IJ V groove is moved in the radial direction of the pulley. It is only slightly displaced, which can reduce string vibrations.

Moreover, when each ■-shaped block 6 is located at both ends of the link plate (2) of the link connecting body 3 (4) with the same structure, the link plate (2) of the other link connecting body 4 (3)
) will be located in the center. Therefore, even if the frictional engagement of the ■-shaped block 6 with the V-shaped JV groove 7 is not performed by the former link plate, it is performed by the latter link plate, and the ■-shaped block 6 that does not frictionally engage with the V-groove 7 is It can be eliminated. Therefore, pulley V
? The load can be shared among all the V-shaped blocks in 87, and it is possible to prevent the load from being applied to a particular V-shaped block.

By the way, in the present invention, as shown in FIG. 1 (C1),
The inner and outer edges 2a and 2b of each link plate 2 forming the inner and outer peripheries of the endless link connection body 3.4 are made into an arc shape along the transmission belt winding arc, and the respective radii of curvature R+ and Rz are determined as follows. . That is, FIG. 2 (al is a schematic diagram when the circular arc diameter of the pulley winding of the transmission belt is the maximum like J, and bl is a schematic diagram when this is an intermediate value (gear ratio 1) like R1.
:l) or a schematic diagram when the value is twice the minimum diameter, the same figure (
C) shows a schematic diagram when this is the minimum like R8.

The radii of curvature R1 and R2 are such that their centers of curvature are on the center of rotation of the boob in the wrapped state shown in FIG. II for each width up to 2b
, , When +1□, R, = R, -H.

Rz = Re + Hz The radii of curvature R+ and Rz are determined so that

In such a configuration, the diameter of the circular arc around which the transmission belt is wound is set to a gear ratio of 1.
Or, in Figure 2 (b
), each endless link assembly 3.4 does not extend in any way from the other endless link assembly 4.3.

As the diameter of the circular arc around which the transmission belt is wound increases in the direction of R7 in Figure 2 fal, the end of the link plate 2 is stretched toward the inner circumference from the adjacent endless link connection body, as shown by 2c in the same figure. put out.

As the diameter of the circular arc around which the power transmission belt is wound is made smaller in the direction of R3 in FIG. put out.

The amount of overhang is shown by the dotted line in FIG. 4, but this amount of overhang is also halved due to the arcuate shape of the inner and outer edges of the link plate. Therefore, there is no need to make the window 68 in FIG. 1(b) as large as before, which should be increased in consideration of this amount of overhang, and the V-shaped block 6 is The tilt caused by backlash can be reduced. Therefore, it is possible to prevent an increase in wear due to abnormal contact of the ■-shaped block 6 and an increase in pulley collision noise.

The pin arrangement pitch, which is reduced by arranging a plurality of endless link bodies 3 and 4 side by side with their pin positions shifted, increases the collision frequency of the transmission belt and increases the power in the transmission using the transmission belt. This is also advantageous in that it shifts the negative wave number from the frequency of the transmission gear and the pump as a hydraulic power source for speed change control, eliminating resonance points and helping to reduce noise.

(Effects of the Invention) As described above, in the power transmission belt of the present invention, since the inner and outer edges of each link plate are formed in an arc shape along the transmission belt winding arc, the endless link connections are mutually connected at the pulley winding portion of the power transmission belt. The amount of overhang can be reduced. Therefore, V for these endless link connections
It is possible to reduce the backlash of the block and reduce abnormal hits caused by the inclination of the block, thereby reducing the wear of the V-shaped block and the noise of pulley collisions.

[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, fb) is a longitudinal sectional front view, Fig. 2(C) is a longitudinal sectional side view of the main part, Fig. 2(a),
(b) and fc) are schematic diagrams showing the spacer winding portion of the same belt for each winding arc diameter, Fig. 3 is an explanatory diagram showing the mutual overhang of the endless link connected bodies, and Fig. 4 is this overhang. FIG. 3 is a diagram showing a comparison between a conventional belt and a belt of the present invention in terms of change characteristics in quantity. l... Pin 2... Link plate 2a... Same inner edge 2b... Same outer edge 2c
, 2d...the same overhang part

Claims (1)

[Scope of Claims] 1. A plurality of endless link connecting bodies each having a large number of pins connected to each other by link plates are arranged side by side so that the positions of the pins are shifted, and these endless link connecting bodies are A power transmission belt in which a large number of V-shaped blocks, which are collectively laterally surrounded and frictionally engaged with pulley V grooves, are sequentially provided in the longitudinal direction of the endless link connectors arranged side by side, inside and outside the endless link connectors. A power transmission belt characterized in that the inner and outer edges of each circumferential link plate are arc-shaped along the V-belt wrapping arc. 2. Claim 1, wherein the arcs at the inner and outer edges of each of the link plates have a common center point.
Transmission belt as described in section. 3. Claim 2, wherein the common center point coincides with the center of the arc around which the V-belt is wound around the gear ratio 1.
Transmission belt as described in section. 4. The power transmission belt according to claim 2, wherein the common center point coincides with the center of the V-belt winding arc when the V-belt winding arc diameter is twice the practical minimum diameter.