JPH0523867Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a block for a power transmission belt used in continuously variable transmissions and the like.

[Prior Art] A belt for a continuously variable transmission used in an automobile power transmission system, a so-called CVT belt, has a driving pulley 1 and a driven pulley 2, as illustrated in FIG.
By changing the radius of the contact position between these pulleys 1 and 2 and the belt 3, an arbitrary speed ratio can be obtained. A conventional belt 3 of this type consists of an endless carrier band 4 made of a thin metal plate having a multilayer structure, and a large number of metal blocks 5 stacked in the length direction of the carrier band 4. Power is transmitted through these blocks 5. The communication will take place.

As an example is shown in FIGS. 5 and 6, the conventional block 5 includes a body portion 7 having a pair of left and right tapered surfaces 6, and a head portion 8 connected to the body portion 7. The carrier band 4 is passed through a groove 9 between the head 8 and the head 8. In addition, in order to position each block 5, a protrusion 10a protruding from one side in the thickness direction, and a protrusion 10a protruding from one side in the thickness direction.
A structure may be adopted in which a recess 10b is provided on the back side of the block 0a, and the protrusion 10a and recess 10b of adjacent blocks are fitted into each other.

Also, Japanese Patent Application Laid-Open No. 60-245853 (prior art 1)
As in the block disclosed in
The radially inner end of the part that is press-fitted into the shaped groove is easily elastically deformed inward in the groove width direction, and
As seen in Publication No. 49151 (prior art 2),
A block with a tapered surface that fits the V-shaped groove of the pulley is provided with a groove for engaging the endless tension band, and when the block is engaged with the pulley and under pressure, the block engages with the side surface of the tension band. A V-belt that is flush with the side surface of the block has also been proposed.

[Problem that the invention attempts to solve]

The conventional block 5 (Fig. 5) mentioned above contacts the pulleys 1 and 2 at the left and right tapered surfaces 6, so when it runs on the pulleys 1 and 2, it moves in the direction shown by arrow A in Fig. 6. The force is received from the driving pulley 1. When the block 5 applies rotational force to the driven pulley 2, it receives a force in the direction A' from the driven pulley 2 as a reaction. Further, forces in the directions of arrows B ₁ and B ₂ act on each block 5 adjacent to each other in the front-rear direction. In this way, the centers of the points of application of the forces received from the front and rear blocks 5 and the points of application of the forces received from the pulleys 1 and 2 are shifted from the direction of movement of the block 5. A moment about an axis parallel to the axis of 2 is generated. For example, in FIG. 6, when receiving a force in the direction of arrow A from pulleys 1 and 2, block 5 tends to fall in the direction of arrow C.

Moreover, since the span _L0 of each tapered surface 6 in contact with the pulleys 1 and 2 is short, the pulley 1 remains in the state in which the block 5 rotates around an axis parallel to the direction of movement, as shown by the two-dot chain line in FIG. (or 2), there is a possibility that the block 5 will be clamped in the V-shaped groove of the pulley 1 (or 2). Moreover, since the span L ₀ is short, the moment of resistance due to the frictional force generated on the contact surfaces with the pulleys 1 and 2 is small. Therefore, there is a problem in that when an external force is applied to the block 5, it tends to fall around an axis parallel to the axes of the pulleys 1 and 2. These problems cannot be solved by the prior art 1 described above.

Therefore, in order to solve the above-mentioned problems, the present inventors devised a block 5' as shown in FIG. 7. This block 5' has two upper and lower tapered surfaces 6a, 6b.
b are in contact with the pulleys 1 and 2, respectively, and the carrier band 4 passes through the groove 9 between the tapered surfaces 6a and 6b.

However, in the case of this block 5', although the span (L ₀ +L ₀ ') in contact with the pulley can be made long, in order for the tapered surfaces 6a and 6b to ideally make line contact with the pulleys 1 and 2, the taper surface 6a , 6b must be finished with high precision. That is, if the dimensional accuracy of the tapered surfaces 6a, 6b is poor, the tapered surfaces 6a, 6b will come into contact with the pulleys 1, 2 unevenly, which will adversely affect the life of the pulleys 1, 2 and the block 5'.

Furthermore, since the above-described prior art 2 also has a long span of the surface in contact with the pulley, unless the angle of the side surface of the block is finished with extremely high precision, the block will come into contact with the pulley unevenly, causing a reduction in service life.

Therefore, the purpose of the present invention is to prevent the block from falling around an axis parallel to the axis of the pulley or rotating around an axis parallel to the direction of movement of the block while the belt is running, and to prevent the block from falling around an axis parallel to the axis of the pulley while the belt is running. The purpose is to allow the block to contact the pulley evenly even if the span of the block is lengthened.

[Means for solving problems]

In order to achieve the above purpose, the present invention provides pulleys 1,
a first body portion 12 having a pair of left and right first tapered surfaces 15 in contact with the slope 1a of the V-shaped groove;
A pair of left and right second tapered surfaces 16 that contact the slope 1a at a position closer to the outer periphery of the pulley than the body portion 12
a neck portion 14 connecting the first body portion 12 and the second body portion 13; and a neck portion 14 located on both sides of the neck portion 14 between the first body portion 12 and the second body portion 13. The present invention is applied to a transmission belt block 11 having a pair of left and right carrier band insertion grooves 17 formed therein. The lower surface side of the first body part 12 (in this specification, the center side of the pulley is referred to as the lower surface side) is located near both ends 12a in the width direction, and both ends 12a are bent slightly downward. A first constricted portion 20 is provided which is hollowed out so that the second constricted portion 20 can be
The upper surface side of the body part 13 (in this specification, the outer circumferential side of the pulley is referred to as the upper surface side) is located near both ends 13a in the width direction, and both ends 13a can be bent slightly upward. A second constricted portion 21 is provided which has a hollow shape.

[Effect]

In the block with the above configuration, the carrier band passes between the first body part and the second body part, the tapered surface of the first body part contacts the pulley below the carrier band, and the second body part contacts the pulley above the carrier band. The tapered surface of is in contact with the pulley. Therefore, when the block runs on the pulley, the discrepancy between the point of action of the force received from the pulley and the point of action of the force received from the front and rear blocks is reduced or eliminated. Also,
Since the first body portion and the second body portion each contact the pulley, a sufficiently long span of contact with the pulley can be obtained. Therefore, this is effective in suppressing the block from falling down about an axis parallel to the axis of the pulley or from rotating about an axis parallel to the direction of movement of the block.

The block of the present invention can bend slightly in the vertical direction at both ends in the width direction due to the constrictions provided in the first body part and the second body part. Even if there is a slight angular difference between the block and the tapered surface, the angular difference is absorbed by the bending of the end. Therefore, even if the span at the point where the block and pulley contact is made sufficiently long, the block can come into even contact with the pulley.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 1 to 3. The belt blocks 11 of this embodiment are used in a state where they are stacked in the thickness direction as in the conventional case. The material of the block 11 may be cermet or ceramics in addition to iron-based metals. The carrier band 4 may be the same as the conventional one, and has a multilayer structure in which a plurality of thin endless belt-shaped steel plates are stacked in the thickness direction. Note that the block 11 can freely slide on the carrier band 4.

The block 11 includes a first body part 12, a second body part 13, and a neck part 14. On both sides of the first body part 12, there are a pair of left and right first tapered surfaces 1 that are in contact with the slope 1a of the V-shaped groove of the pulley.
5 is provided. Further, the second body portion 13 is provided with a pair of left and right second tapered surfaces 16 that contact the pulleys 1 and 2 at a position above the first body portion 12 . In FIG. 3, the line indicated by a dashed dotted line is the line of contact with the pulleys 1 and 2.

Moreover, between the first body part 12 and the second body part 13, grooves 17 for passing the carrier band 4 are provided on both left and right sides of a neck part 14 that connects them to each other. The first body portion 12 has a taper start line 1 in a side view (FIG. 3).
It has a tapered shape with the lower side slightly tapered at 8. By having such a tapered shape, it is possible to cope with bending when the block 11 passes through the pulleys 1 and 2.

Then, on the lower surface side of the first body part 12, a first constriction part 2 is located near both ends 12a in the width direction.
0 is set. This constriction 20 is the first
Both end portions 12a of the body portion 12 are hollowed out so that they can be bent slightly downward. Further, on the upper surface side of the second body portion 13, a second
A constricted portion 21 is provided. The constricted portion 21 is hollowed out so that both ends 13a of the second body portion 13 can be bent slightly upward. The two-dot chain line in FIG. 2 shows the outline of a conventional block without a constriction.

Furthermore, a protrusion 23 protruding in the thickness direction of the block 11 and a depression 24 located on the back side of the protrusion 23 are provided at the center in the width direction of the second body portion 13. This recess 24 is formed in a size such that the protrusion 23 of the block 11 located on the rear side can fit therein. In addition, the protrusion 23 and the depression 2
4 is not limited to the illustrated example. for example,
The protrusion 23 and the depression 24 may be provided so as to be located on the taper start line 18, respectively.

The block 11 has a first body part 12 and a second body part 12.
By providing the body portion 13 with the constricted portions 20 and 21, the widthwise opposite ends 12a and 13a can be slightly bent in the vertical direction. For this reason,
Even if there is a slight angular difference between the slope 1a of the V-shaped groove of the pulley and the tapered surfaces 15, 16 of the block 11, the ends 12a, 13a will not move as shown exaggeratedly by the two-dot chain line in FIG. By bending, the slope 1a of the V-shaped groove
This allows the tapered surfaces 15 and 16 to come into equal contact with the pulleys ₁ and 2 over the spans L 1 and L ₂ . In other words, tapered surface 1
5 and 16 can be increased.

For example, for an inclination angle of 11° on the slope 1a of the V-shaped groove,
Adjust the angle θ of the tapered surfaces 15 and 16 (see Figure 1) to ±
Allowable up to 11°5′. In addition, the end portions 12a, 13
Since the rigidity of a is softened, the contact surfaces of the pulleys 1 and 2 will fit better.

Further, the carrier band 4 passes through the groove 17 between the first body part 12 and the second body part 13, and furthermore, on the lower side of the carrier band 4, the first tapered surface 15 contacts the pulleys _{1 and} 2 with a span L 1. , on the upper side of the carrier band 4, the second tapered surface 16 contacts the pulleys 1 _{, 2} with a span L2. Therefore, when the block 11 runs on the pulleys 1 and 2, the force received from the drive pulley 1 is divided into two parts, upper and lower, as shown by arrows F ₁ and F ₂ in FIG. The force received from the driven pulley 2 is divided into two parts, upper and lower, as shown by arrows F ₁ ' and F ₂ ' in FIG. Also, the forces received from the front and rear blocks come between the points of action F ₁ , F ₂ and F ₁ , 'F ₂ ', as shown by arrows F ₃ and F ₄ .
Therefore, the forces become balanced, and almost no moment is generated for rotation around an axis parallel to the axes of the pulleys 1 and 2.

Moreover, the contact span between the block 11 and the pulleys ₁ and 2 is the sum of L1 and _L2 , and the span can be made sufficiently long. Therefore, block 1
This is effective in preventing block 1 from falling around an axis parallel to the axes of pulleys 1 and 2 or rotating around an axis parallel to the direction of movement of block 11. In addition, the weight can be reduced by the amount by which the constrictions 20 and 21 are thinned out, and the burden on the carrier band 4 due to centrifugal force is reduced. Note that the ratio of the spans L ₁ and L ₂ mentioned above is
L 1 :L 2 = L 1 :L 2 = L ₁ :L ₂ = A ratio of around 6:7 is optimal.

[Effect of idea]

According to the present invention, it is possible to suppress the movement of the block falling around an axis parallel to the axis of the pulley or the movement of trying to rotate around an axis parallel to the running direction of the block, and the tapered surface of the block is even with the pulley. This reduces the factors that degrade the durability of pulleys, blocks, and carrier bands, resulting in a transmission belt with a longer service life.

[Brief description of the drawings]

Figures 1 to 3 show one embodiment of the present invention, with Figure 1 being a front view of the block, Figure 2 being a front view showing the relationship between the block and the V-shaped groove, and Figure 3 being a side view of the block. 4 is a side view conceptually showing the relationship between the belt and the pulley, FIG. 5 is a front view of the conventional block, and FIG. 6 is a side view of the conventional block shown in FIG. FIG. 7 is a front view showing an improved version of the conventional block. 1...Drive side pulley, 1a...Slope of V-shaped groove,
2... Driven pulley, 4... Carrier band, 1
1...Block, 12...First body part, 12a
...End, 13...Second body part, 13a...End, 14...Neck, 15...First tapered surface, 16
...Second tapered surface, 17...Groove, 20...First constriction, 21...Second constriction.

Claims (1)

[Scope of claim for utility model registration]
a first body portion having a tapered surface; a second body portion having a pair of left and right second tapered surfaces contacting the slope at a position closer to the outer periphery of the pulley than the first body portion; A power transmission belt block comprising a neck connecting two body parts, and a pair of left and right carrier band insertion grooves located on both sides of the neck and formed between the first body part and the second body part. and a first constriction located on the lower surface side of the first body portion near both ends in the width direction and having a hollow shape so that both ends can be bent slightly downward. A second constriction is provided on the upper surface side of the second body part, and the second constriction is located near both ends in the width direction of the second body part and is hollowed out so that both ends can be bent slightly upward. A power transmission belt block characterized by having a section.