JPH03219148A - V-belt - Google Patents

Abstract

PURPOSE:To prevent generation of frictional loss of power so as to improve transmission efficiency in the accelerated transmission state frequently used by setting band contact radiuses in relation to the V-block row with pulleys in the wound state to be smaller than the pitch line radiuses of the V-block. CONSTITUTION:A V-belt performs the specified power transmission between V-groove pulleys, 4, 5 through a row of V-blocks 2 and an endless band 1 in frictional contact with these V-blocks 2. Band contact radiuses R1B, R2B in relation to the V-block row in the region of winding on the V-groove pulleys 4, 5 are set smaller than the pitch line radiuses R1P, R2P of the V-block 2 obtained by connecting together the bent positions of the V-block row. As a result, the band 1 transmits the torque in the same direction as that of the V-block 2 in the accelerated transmission state, and the direction by the frictional force acting between the V-block 2 and band 1 coincides with the transmission direction so as not to generate the frictional loss of power. Transmission efficiency in the accelerated transmission state frequently used can be thereby improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a V-belt, and in particular to an assembled V-belt.

(Prior art) This type of belt is used to transmit large amounts of power at variable speeds, such as in continuously variable transmissions.
It is constructed as described in the publication.

As shown in FIG. 8, this V-belt includes an endless laminated band 1, and a number of V-shaped blocks 2 (only one is shown in the drawing) are sequentially arranged along the endless band 1 so as to be in frictional contact with the endless laminated band 1. and assemble. Each ■-shaped block 2 has a tapered surface 2a that contacts the pulley ■-groove side surface 3, and these tapered surfaces are brought into contact with the pulley V-groove side surface 3 to form a row of V-shaped blocks 2.
A V-belt is put into practical use by wrapping it between grooved pulleys. During this practical use, ■ Band 1 in the wrapping area of the groove pulley and ■
Transmission between the shaped block 2 and the shaped block 2 is carried out by frictional contact at the contact surface 2b between the two. In addition, when the ■-groove pulley is wrapped around the ■-shaped blocks 2, adjacent ■-shaped blocks 2 need to tilt relative to each other in the winding direction. Therefore, as shown in FIG. 8(c), each ■-shaped block 2 is A relief surface 2c is provided on at least one example of the block 2, and the plate thickness t of each square block 2 is made thinner toward the center of rotation of the pulley. As a result, the relative tilting of the adjacent V-shaped blocks 2 occurs around the starting edge 2d of the flank 2c.

(Problem to be Solved by the Invention) However, in the conventional V-belt, since the band contact surface 2b of the ■-shaped block 2 is located outward in the pulley radial direction from the flank starting edge 2d by ΔR, the ■ belt In the speed-up transmission state shown in FIG. 9, the following problem occurs.

In Fig. 9, 4 indicates a driven groove pulley, and 5 indicates a driven groove pulley. Figure 9 shows that ■Held is performing speed-up transmission. Considering the area in which the ■ heald is wrapped around both pulleys 4 and 5 in this state, the contact radius of the band l with respect to the row of ■-shaped blocks 2, that is, the band contact surfaces 2b of adjacent ■-shaped blocks 2 are successively connected. The radius of the dashed line (hereinafter referred to as band contact radius) is RIB on the driving pulley 4 side, R2J on the driven boob U5 side, and the adjacent ■-shaped block 2
The radius of the pitch line of the ■-shaped blocks (
Hereinafter referred to as the pitch line radius) is R on the drive pulley 4 side.
IP, l on the driven pulley 5 side? zp, R11l-R1, -ΔR>O on the driving pulley 4 side, and fhm R2F =ΔRho on the driven pulley 5 side. Therefore, in the speed-up transmission state, it is inevitable that a frictional loss of power will occur due to the frictional force generated between the ■-shaped block 2 and the band 1 on the driven pulley side as explained in the following theory.
A decrease in transmission efficiency cannot be denied.

That is, in FIG. 10, which shows the same state as FIG. 9, if the drive pulley 4 rotates at an angular velocity of ω, and there is no relative velocity between the ■-shaped block 2 and the band 1 on the drive pulley. Assuming this, the moving speed VIP of the pitch line of the ■-shaped block in the driving booth, the moving speed VIP' of the band contact surface, and the moving speed V1m of the band are each expressed by the following equations.

V I P = RI P・ω1 VIP'=(RIP+ΔR)ω Lm −RIB ・ω+ −(RIF+ ΔR) (+
)1', 'VIP' = VI11 Also, since the speed at the driving pulley is transmitted as is on the driven pulley, the moving speed of the pitch line of the ■-shaped block VZF
The moving speed V2m of the band and the moving speed V2m of the band are respectively expressed by the following formula (%). At this time, if the angular velocity of the pitch line of the ■-shaped block at the driven pulley is ωzp, and the angular velocity of the band is ω2, then VZF ""RZP fist ω22 R□ Also, V2m = (RZP + ΔR) (1) KM. On the other hand, the moving speed V2F' of the band contact surface of the ■-shaped block on the driven pulley is naturally V2F' = ωZP (
RAP+ΔR). Therefore, on the driven pulley, a relative velocity Vr of the following equation is generated between the band and the band contact surface of the square block as shown in FIG.

Vr=νZP V211 -ωZP (Rzp+ΔR) (RIP+ΔR)ω1
2F ZF By the way, in the speed-up transmission state, R1+'>R2F,
Also, since ΔR>O, Vr found by the above formula is Vr>
0, and it can be seen that the ■-shaped block moves faster than the band. From this, a frictional force acts between the ■-shaped block and the hunt in the driven pulley, and a frictional force acts on the ■-shaped block in the direction of arrow a in FIG.

However, it was also proven that frictional forces act on the bands in the directions indicated by the arrows in the figure.

At this time, the transmission sharing ratio between the ■-shaped block and the node is the first.
The result will be as shown in Figure 1. In other words, the compressive force of the ■-shaped block in the upper running part of the figure is QA, and the tension of the band is TA.
If the compressive force of the ■-shaped block in the lower running part of the figure is QR, and the tension of the band is TB, then due to the structure of the ■belt, the compressive force of the ■-shaped block is only generated in one running part, and Q++=0. Therefore, if the direction of the force is assumed to be QA>0, then QA>Q, and the tension of the band is Ta<T.
m<.

becomes.

On the other hand, when looking at the transmission torque Tr of the V-belt from the drive pulley side, when the center value of the band winding radius is R111, Tr+ = (QAQ[1) RIP±(TA Tl1)
R11+=QARIF+(Ta TB) R1
1! It is expressed as In this second case, QARIP>O1
Also, (TA Tl1) R11,'< OT: Therefore, in the speed-up transmission state, the ■-shaped block transmits positive torque, while the band transmits negative torque, resulting in frictional loss of power. occurs.

Incidentally, in the deceleration transmission state, the frictional force acting between the V-shaped block and the band coincides with the transmission direction, so the above-mentioned friction loss does not occur.

However, in continuously variable transmissions, where V-belts are mainly used, they are often used in an increasing transmission state to improve fuel efficiency.
In terms of overall transmission efficiency, it is more disadvantageous in terms of overall transmission efficiency if a frictional loss of power occurs in a speed-up transmission state than if a frictional loss of power occurs in a deceleration transmission state.

In this sense, conventional V-belts are disadvantageous, and an object of the present invention is to solve the above-mentioned problems by providing a V-belt that does not cause any frictional loss of power in the speed-up transmission state.

(Means for Solving the Problems) For this invention, the V-belt of the present invention is constructed by assembling a large number of V-shaped blocks so as to be in frictional contact with the belt along an endless band, and the rows of these V-shaped blocks are arranged in V-shaped grooves. In a V-belt used by being wound between pulleys, the band contact radius with respect to the ■-shaped block row when wrapped around the ■-groove pulley is determined by the pitch line of the ■-shaped block connecting the bending positions of the V-shaped block row. The radius is below.

(Function) The V-belt transmits a predetermined power between the groove pulleys via a large number of rows of ■-shaped blocks and an endless band that frictionally contacts them.

By the way, in the case of winding around the groove pulley, the contact radius of the band with the ■-shaped block row was set to be less than the radius of the pitch line of the V-shaped block connecting the bending positions of the V-shaped block row, so that (2) The band transmits torque in the same direction as the V-shaped block, and the frictional force acting between the V-shaped block and the band coincides with the transmission direction, making it possible to eliminate frictional loss of power. Therefore, it is possible to improve the transmission efficiency in the frequently used speed-up transmission state.

(Example) Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an embodiment of the V-belt of the present invention, in which (a) is a sectional view taken in a plane perpendicular to the heald running direction, and (c) is a side view of one V-shaped block. Similar parts to those in the figures are designated by the same reference numerals.

In this example, the endless band 1 is constructed by laminating four endless band elements 18 to lb in the circumferential direction.

Each ■-shaped block 2 which is brought into abrasion contact with the pulley groove side surface 2a has a notch 2e, through which the band 1 is passed and the innermost band element 1d is inserted into the bottom surface 2b of the notch 2e.
and close the open end of the notch 2e with the pin 6.

Each ■-shaped block 2 is further formed with a concave portion 2f and a convex portion 2g that fit into each other to prevent adjacent blocks from being displaced in the vertical and horizontal directions in FIG. 1(a).

Then, the contact surface 2b of the band 1 with respect to the ■-shaped block 2
is positioned toward the tapered end of the ■-shaped block 2 by ΔR' from the starting edge 2d of the flank 2c.As a result, the V-belt winding in FIG. 2 corresponding to FIG. As is clear, the band contact radius RIB on the driving pulley 4 side is smaller than the pitch line radius RIF of the ■-shaped block by ΔR' (R4N+RIP−Δ
R'<O), the band contact radius RZI also on the driven pulley 5 side
I is Δ from the pitch line radius 11zp of the ■-shaped block
It becomes smaller by R' (RZ-RZF ""ΔR'<0
).

Here, considering the frictional loss of power in the speed-up transmission state shown in Fig. 2, the pitch line moving speed VIP of the ■-shaped block on the driving pulley side, the moving speed ν4 of the band contact surface 2b, and the moving speed of the band 1. Vllll is expressed by the following equation, respectively, where ω1 is the angular velocity of the drive pulley.

V I P = RI Pφω.

VIP'=(RIF-ΔR') ω.

V+i −RIB @ω+ = (RIF−ΔR') ω
.

Further, the pitch line moving speed VZF of the ■-shaped block on the driven pulley side and the moving speed V2B of band 1 are expressed by the following equations.

Vzp-RIF” (1+3+ Vzm = (RIP-ΔR') ω.

At this time, if the pitch line angular velocity of the V-shaped block at the driven pulley is ω2F and the angular velocity of band 1 is ω2B, then these are respectively V 2 F =R2F·ω2. Yorimata Vz+
+ = (Rzp-ΔR') from ωzB.

Also, in the driven pulley, the band contact surface 2b of the ■-shaped block
moving speed v2. ' is V2F' = ωzp (RZ
P AR'), and the relative velocity Vr between the band contact surface 2b of the ■-shaped block and the band 1, which is expressed by the difference between this and the above-mentioned VZ11, is Vr=Vzr vzl+ =ωtp (RZP -ΔR') - (RIF −
ΔR') is determined by ω1. By the way, in the speed-up transmission state, RIP>RAF, -ΔR'<0, so Vr found by the above equation becomes Vr<O, which proves that ■-shaped block 2 moves at a slower speed than band 1 on the driven pulley side. It was done.

Therefore, on the driven pulley, a frictional force acts on the ■-shaped block 2 in the direction of the arrow in FIG.
directional frictional force acts.

At this time, the transmission sharing ratio between the ■-shaped block and the band is as shown in FIG. That is, the compressive force QA due to the ■-shaped block and the band tension TA are generated in the upper running part of the figure, and the band tension T is generated in the lower running part of the figure.
, only occurs.

As mentioned above in Fig. 11, if the direction of force is QA>0, then T! l<TA<0.

On the other hand, ■When looking at the belt transmission torque Tr+ on the drive pulley side, the center value of the band winding radius is R11! In this case, as described above, it is expressed as TrI=QA RIF + (TA Te1) RIB. In this formula, QARIP>01(TA
Tl1) Since RIB'> O, in the speed-up transmission state, the ■-shaped block is transmitting positive torque, but the band also transmits positive torque, and no friction loss of power occurs.

Therefore, since there is no frictional loss of power in the frequently used high-speed transmission state, the overall transmission efficiency of a continuously variable transmission or the like using the transmission heald of this example can be improved.

In the above example, the band contact radius R+m (Rzm) is smaller than the pitch line radius RIP (RAF), but
Even when both are the same (ΔR'-0), the above V
Since r becomes 0, frictional loss of power can be eliminated.

FIG. 4(a), O:I) is another example of the belt according to the present invention,
In the figure, the same parts as in FIG. 1 are designated by the same reference numerals.

In this example, the endless bands 1 are arranged in two rows, each in frictional contact with the surface 2b of each square block 2, and the flank 2c is formed only on one surface in the belt running direction. By locating the band contact surface 2b toward the tapered end of the V-shaped block 2 by ΔR' with respect to the flank starting edge 2d, the same effects as in the previous embodiment can be achieved.

Incidentally, as shown in FIGS. 5(a) and 5(b), the same effect can be obtained by setting the band contact surface 2b at the same level as the flank starting edge 2d and setting ΔR'-0. However, in this case, in consideration of manufacturing errors and variations in the V-shaped block, the band contact surface 2b is slightly shifted toward the tapered end of the ■-shaped block 2 from the flank starting edge 2d in order to compensate for the effect. It goes without saying that this is a good thing.

FIGS. 6(a) and 6(b) show still another example of the present invention,
In this example, the opening end of the band insertion notch 2e is not completely closed as shown in FIG. It was designed so that it would never happen. In this example as well, the band contact surface 2b is smaller than the flank starting edge 2d by ΔR'.
By positioning it closer to the tapered end of the shaped block, it is possible to achieve the same effects as in each of the embodiments described above.

FIGS. 7(a) and 7(b) show still another example of the present invention,
In this example, a type having two bands 1 is used, and the tapered surface 2a of each ■-shaped block 2 is formed on the side opposite to the tapered end of the ■-shaped block. In this example as well, the band contact surface 2b is positioned closer to the tapered end of the ■-shaped block than the flank starting edge 2d,
It is possible to achieve the same effects as in each of the embodiments described above.

(Effects of the Invention) Thus, as described above, the belt of the present invention has a contact radius of the band with the ■-shaped block row in the state of being wound around the pulley to be equal to or less than the pitch line radius of the V-shaped block row. Torque is transmitted in the same direction as the block, and the frictional force acting between the ■-shaped block and the band coincides with the transmission direction, making it possible to eliminate frictional loss of power. Therefore, it is possible to improve the transmission efficiency in the frequently used speed-up transmission state.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the V-belt of the present invention, and FIG.
is a cross-sectional view in a plane perpendicular to the belt running direction, (b)
is a partial side view, Fig. 2 is a vector diagram showing the belt in an increased speed transmission state, Fig. 3 is a diagram showing the transmission sharing ratio by the ■-shaped blocks and bands of the same belt, Fig. 4 (a) ), [Yes]) are sectional views and partial side views similar to FIGS. 1(a) and (b) showing other examples of the V-belt of the present invention, and FIGS. 5(a) and (b) are the same A sectional view and a partial side view similar to FIGS. 4(a) and 4(a) showing a modified example of the belt,
FIG. 6(a), [with]) is a sectional view and partial side view similar to FIGS. 1(a) and (b), showing still another example of the V-belt of the present invention, and FIG. 7(a), (b) is a sectional view and side view similar to FIGS. 1(a) and (b) showing still another example of the belt according to the present invention, and FIGS. 8(a), (b), and (C) are respectively A cross-sectional view, a side view, and a plan view of a conventional ■belt in a plane perpendicular to the belt running direction; Fig. 9 is a usage state diagram showing the speed-up transmission state of the same belt; Fig. 10 is a diagram showing the state of use of the same belt in the same state. Vector Diagram FIG. 11 is a diagram showing the transmission sharing ratio by the V-shaped block and band of the Heald in the same state. 1... Endless band 2... ■-shaped block 2a
... Tapered surface 2b ... Band contact surface 2c
...Escape surface 2d...Escape surface start record 4.
・・Drive ■Groove pulley 5・・Driver ■Groove pulley R, □
R211...Band contact radius RIP, R2A...Pinch line radius Fig. 1 (a+ (1)) Fig. 4 (a) Fig. 5 (a) (b) Printing of the drawing (no changes in content) Bundle 1 (b) Figure 6 fa) (bl Figure 7 (a) (b) Figure 9 ζ (b (C) shi-~-J1 Procedural amendment (method) 1. Indication of the case 1990 Patent Application No. 3671 2. Title of the invention ■ Ruto 3. Relationship with the person making the amendment case

Claims (1)

[Claims] 1. A V-belt constructed by assembling a large number of V-shaped blocks along an endless band so as to be in frictional contact therewith, and used by winding a row of these V-shaped blocks between V-groove pulleys. In the V-groove pulley, the contact radius of the band with the V-shaped block row is less than or equal to the radius of the pitch line of the V-shaped block connecting the bending positions of the V-shaped block row. belt.