JPS6346299B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a power transmission device, particularly one using a multi-protrusion belt. (Prior Art) In general, compared to a V-belt, a multi-protrusion belt having a plurality of engagement protrusions in the belt running direction has the following advantages: (i) it can be applied against relatively small diameter pulleys; (ii) It has advantages such as excellent reverse bending resistance and (iii) relatively long life, so it is widely used in power transmission devices. Conventionally, as such a power transmission device, the first
As shown in FIG. ，
It is known to be wound around a plurality of pulleys e having a plurality of pulley grooves d, d, d into which the pulleys b and b fit. By the way, in a belt having a tensile material,
Although there may be some discrepancies depending on the belt structure, the tension body, and the degree of Young's modulus of the belt material, the pitch line almost matches the position of the tension body, and generally the pitch line is determined by the position of the tensile body. However, when the inside dimension from the pitch line is large like the belt As a result of being subjected to extreme compression, the engagement protrusions are unable to absorb this compression and meander, hanging on the pulley as it is, producing an abnormally high squeak. In addition, when a tension pulley is used to press from the side of the band-shaped part a, the part outside the pitch line is compressed and the part inside is expanded, but in this case, the top of the engagement ridge is a considerable distance from the pitch line. extremely stretched to be in
There is a problem in that the protrusions crack and break. Therefore, in order to solve the above problem, for example,
As shown in FIG. 11, a pulley g has a plurality of V-shaped grooves f in contact with each other on the circumferential surface, and the groove f
A multi-row belt k having a V-shaped protrusion h that fits into each of the V-shaped protrusions h and a band i commonly joined to each V-shaped protrusion h at the base of each V-shaped protrusion h, A tensile member 1 is inserted into the inside of each V-shaped ridge h inside the base line of the V-shaped ridge h, and the innermost part of each V-shaped ridge h and each groove f of the pulley g is connected. A power transmission device has been proposed in which a gap m is provided between the valleys between the V-shaped protrusions h and the tops of the grooves f of the pulley g (Japanese Patent Publication No. 49-7817
(see publication). (Problems to be Solved by the Invention) In this device, the tension member 1 of the belt is the first
Since the V-shaped protrusions h, h... are placed much more inward than the conventional belt shown in Figure 0, the pitch line also moves inward accordingly. As a result, the distance from the pitch line to the top of the V-shaped ridges h, h... is reduced, and the degree of compression that the V-shaped ridges receive when bending along the pulley g is reduced, which reduces the squeak noise caused by meandering. The occurrence of cracks is reduced, and the V-shaped protrusions receive less stretch when pressed from the opposite side by a tension pulley, so cracks do not occur, but the tensile member 1 does not crack due to the protrusions h, h... Since the pulley diameter is small and the transmission capacity is poor, the belt-shaped part (the side surface of the i) hardly contributes to power transmission. Since it has been used in automobiles, the usage conditions have become harsher, and in addition to the trend towards compactness, there is also a demand for improvements in transmission horsepower and lifespan, which has the drawback of not being able to adequately meet these demands. The present invention has been made in view of this point, and the tensile material is left embedded in the strip part of the multi-protrusion belt, and the strip part is made trapezoidal in cross section, and the pulley around which the multi-protrusion belt is wound is adapted to the same shape. The purpose of the present invention is to provide a power transmission device that eliminates the above-mentioned drawbacks of the conventional belt by giving the band-shaped portion a V-belt-like mechanism and exerting a wedge effect on the entire multi-protruded belt. shall be. (Means for Solving the Problems) The structure of the present invention for achieving the above object is a multi-protrusion belt in which a plurality of engagement protrusions are provided to protrude from the lower surface of the belt-like part along the longitudinal direction. and a plurality of pulleys each having a plurality of pulley grooves into which each engaging protrusion of the multi-protrusion belt fits, and the belt-shaped portion of the multi-protrusion belt is made of a tensile member. is buried and has an essentially trapezoidal cross-section with an upper side larger than a lower side, and the entire multi-protrusion belt is formed into a substantially V-shape, while the outermost pulley groove surface of each pulley is larger than the other pulley groove surfaces. is further formed to extend outward in the radial direction and has a shape corresponding to the outer surface of the engagement protrusion and the strip portion, and the multi-protrusion belt Both outer surfaces of the pulley are in substantially full contact with both outermost pulley groove surfaces of the pulley. (Function) The multi-protrusion belt in which the tensile member is embedded has a trapezoidal cross section and the inclined side surface of the band part and the side surface of the engaging protrusion are brought into full contact with the pulley groove surface. The entire belt, including the parts, functions like a V-belt and exhibits a wedge effect. (Example) Examples of the present invention will be described below with reference to the drawings. Embodiment 1 In FIG. 1, 1 is a power transmission device,
A multi-protrusion belt A in which a plurality of engagement protrusions 3, 4, 5 are provided to protrude from the lower surface of the belt-shaped portion 2 along the longitudinal direction.
and a plurality of pulleys 10 having a plurality of pulley grooves 7, 8, 9 into which the engagement protrusions 3, 4, 5 of the multi-protrusion belt A fit. The strip portion 2 of the multi-projection belt A has the following cross-section:
Both side surfaces 2a, 2a of the band-shaped portion 2 have an essentially bilaterally symmetrical isosceles trapezoidal cross section with the upper side larger than the lower side.
However, the outer surfaces 3a and 5a of the outermost engagement protrusions 3 and 5
In other words, they are formed continuously in substantially the same plane. Inside this band-shaped part 2, in order from the top, there are upper canvas 11, 12, an upper rubber layer 13, an adhesive rubber layer 15 in which a tensile member 14 is embedded, and a lower rubber layer 16.
are layered. The upper canvas 11, 12 is a woven fabric made of cotton, polyester, nylon, aramid, or a blended yarn thereof, which is plain-woven, wide-angle, or stretch-treated, and is bonded and rubberized by a known method. It is used as As the tensile member 14, the tension of the multi-protrusion belt A,
Thickness, twist, etc. are set considering flexibility etc.
Using polyester, nylon, aramid,
A material that has been subjected to a known adhesive treatment is used. The adhesive rubber layer 15 is made of a rubber-like elastic material such as CR, NR, SBR, NBR, or urethane that is compatible with the usage conditions of the multi-protrusion belt A, and is made of a known rubber compound that is particularly advantageous for adhesion. It will be done. The upper and lower rubber layers 13, 16 and the engagement protrusions 3, 4, 5 are made of a rubber-like elastic body made of the same material as the adhesive rubber layer 15, and have particularly good lateral pressure resistance and friction resistance (friction coefficient). This is a well-known rubber compound that takes into consideration the above-mentioned properties, but filaments of cotton, rayon, nylon, polyester, aramid, carbon fiber, etc. are cut into appropriate lengths and, if necessary, known adhesive treatments are applied. A belt is used in which the particles are distributed uniformly and the belt is placed almost perpendicular to the longitudinal direction of the belt. Example 2 In this example, a lateral pressure reinforcing material was provided to further improve lateral pressure properties. In FIG. 2, a lateral pressure reinforcing material 21 is provided below the adhesive rubber layer 15 (tensile member 14). Note that the other configurations are the same as in the first embodiment. In addition, in order to further increase the lateral pressure property than the multi-projection belt B shown in FIG. 2, the multi-projection belt C shown in FIG.
2 are arranged. As such lateral pressure reinforcing members 21 and 22, a canvas having the same structure as the upper canvas 11 and 12, or a blind made of cotton, rayon, polyester, nylon, or Kevlar and subjected to an adhesive treatment is used. Next, a method for manufacturing the multi-protrusion belt will be described. Manufacturing method 1 First, on a split mold which is a cylindrical mold and has a large number of V-grooves in the circumferential direction on the outer circumferential surface, a large number of rubber-like elastic bodies containing filaments that will become engagement protrusions are formed in advance into a V-shape. Insert the shaped object into the groove. An adhesive rubber sheet is wrapped thereon, a lateral pressure reinforcing material is inserted as required, and a tensile material is then spirally wound. Next, if necessary, add lateral pressure reinforcement, and finally wrap the rubberized upper canvas the required number of times to complete the molding. Next, an elastic cylindrical sheet is fitted as a sleeve on the outside of this molded product, and the molded product is vulcanized in a vulcanizing can (for example, an autoclave). When vulcanization is completed, the sleeve (elastic cylindrical sheet) is removed, and after cooling, the vulcanized product is removed from the mold, pulled repeatedly, placed in a cutting mantle, and cut at a predetermined angle. Manufacturing method 2 First, molding is performed in the opposite manner to manufacturing method 1 on a cylindrical mold with a smooth outer circumferential surface. However, it becomes an engagement protrusion,
A rubber elastic body containing filament is simply a sheet that is wound in the required amount. Then, by wrapping the lateral pressure reinforcing material and the above canvas,
Vulcanize in the same manner as in manufacturing method 1. When vulcanization is completed, the sleeve is removed, cooled, and the vulcanized product is removed from the mold. Then, it is placed in a mantle as it is, and the portion that will become the engaging protrusion is formed into a V shape. Methods include (i) scraping with a V-blade, (ii) scraping with a hob cutter, and (iii) scraping with a grinder. When a large number of V-shaped portions are formed in the circumferential direction of the vulcanized product in this manner, the portions are cut at the required angle using a cutter. Next, various tests in which the performance of multi-protrusion belts A, B, C, and X were compared and examined will be explained. The test device has a diameter of 120 mm as shown in Figure 6.
Drive pulley 31 (4900r.pm) and driven pulley 3
2. A multi-protrusion belt 34 with three engaging protrusions and a belt length of 980 mm is wound around an idle pulley 33 (applying force F in the tensioning direction) having a diameter of 90 mm. (1) Comparison of transmitted horsepower (test method) Using the device shown in Figure 6, a load of F = 90 kg was applied to the idle pulley 33, and (1) the transmitted force when the slip rate was 1%, (2) ) The change in slip ratio when the load horsepower was changed was measured. (Test Results) The test results are shown in Table 1 and FIG.

[Table] From the above table, the transmitted horsepower is more than 30% greater with the multi-protrusion belt A (see Figure 1) according to the present invention than with the conventional multi-protrusion belt X (see Figure 10). ing. In the multi-projection belt A, both sides 2a, 2a of the belt-shaped portion 2 are also connected to the pulley 3.
It is thought that this is because it acts as a friction surface with 1 and 32, that is, the entire belt acts as if it were a V-belt. Therefore, in the multi-projection belts B and C in which the lateral pressure reinforcing materials 21 and 22 are embedded, the lateral pressure property increases,
Furthermore, the transmitted horsepower increases. Furthermore, from FIG. 7, it can be seen that the multi-protrusion belts A, B, and C according to the present invention have a smaller increase in slip rate than the conventional multi-protrusion belt X. (ii) Comparison of durability life (test method) Using the device shown in Figure 6, a load of F = 90 kg was applied to the idle pulley 33, and the load horsepower to the driven pulley 32 was maintained at 18 PS. I took the test. (Test Results) The test results are shown in Table 2.

[Table] From Table 2, multi-protrusion belt A according to the present invention,
It can be seen that the durability time of B and C is more than 60% longer than the conventional multi-protrusion belt X. (iii) Relationship between belt tension and noise (test method) Using the device shown in Fig. 6, a load of F = 90 kg was applied to the idle pulley 33, and the load horsepower to the driven pulley 32 was set to 10 PS. The critical tension for noise generation was measured. (Test results) The test results are shown in Table 3.

[Table] From Table 3, the limit tension of the multi-protrusion belt A according to the present invention is determined by the conventional multi-protrusion belt X.
It can be seen that B and C are sufficiently small and there is plenty of room during use. The standard tension of the belt is 45Kg.
It is. (iv) the inclination angle of the outer surface of the strip, the durability life,
Relationship with transmitted horsepower (test method) Using the testing device shown in Figure 6, a load of F = 90 kg was applied to the idle pulley 33, and the upper angle α (see Figure 9) of the multi-projection belt 34 was changed. The effect of this on transmitted horsepower and life was measured. The test was conducted at a load horsepower of the driven pulley 32 of 18PS. (Test Results) The test results are as shown in Figure 8. 8th
It can be seen from line Y in the figure that the transmitted horsepower decreases as the belt upper angle α increases. On the other hand, from line Z, the life is determined by the upper angle α
is the tip angle β of the engagement protrusion (see Figure 9) of 40~
It can be seen that it is the longest when the size is 50%. Therefore, the belt upper angle α should be within a range that has a long belt life and a relatively large transmitted horsepower, that is, -12 to +12% of the tip angle β.
A size in the range of is desirable. For example, if the tip angle β is 40 degrees, the belt top angle α is 17.5
It is best to be in the range of 22.5 degrees to 22.5 degrees. (v) Relationship between misalignment and belt jumping (test method) In a 2000c.c. diesel engine, the 6th
In the device shown in the figure, the idler pulley 33 is
= 25Kg load was applied, and the rotation speed of the drive pulley 31 was changed from (i) 0 to 5000r.pm for 5 seconds, (ii) 5000r.pm
One cycle consisted of changing the speed from 5000r.pm to 0r.pm for 10 seconds and (iii) 5000r.pm to 0r.pm for 5 seconds, and the process was repeated 50 times to check for jumping. (Test Results) (1) In the multi-protrusion belt X of the type shown in FIG. 10, the belt X jumped at the 20th alignment after one alignment. (2) Multi-protrusion belt A of the type shown in Figure 1
In this case, although the alignment was changed up to 3 degrees, no jumping occurred in belt A. It should be noted that if the test occurred more than 3 times, the test was discontinued due to severe fatigue of the tensile member. (vi) Relationship between the number of engaging protrusions and transmitted horsepower (test method) Using the device shown in Figure 6, a load of F = 90 kg was applied to the idler pulley 33, and the slip ratio was 1%. Changes in transmission horsepower were measured.
Note that the multi-protrusion belts X type and A type used in the test are different from the multi-protrusion belts X and A types except for the number of engagement protrusions.
Basically the same as A. (Test Results) The test results are shown in Table 4. That is,
It can be seen that the effect is greatest when the number of engaging protrusions is three, and as the number increases, the effect decreases.

[Table] Note that when the number of engaging protrusions is two, the buckling of the back becomes particularly large and the transmission capacity is reduced, so it is desirable to have three or more engaging protrusions. Moreover, in Examples 1 and 2, both side surfaces 2a, 2a of the band-shaped portion 2 are formed continuously in essentially the same plane as the outer surfaces 3a, 5a of the outermost engagement protrusions 3, 5. However, in addition to the above
As is clear from the test results in (vi), both side surfaces of the band-shaped portion deviate from the outer surface of the outermost engagement ridge by an angle of 40 to 60% of the tip angle of the outermost engagement ridge. It can also be configured to do so. As a specific example, Example 3 will be described next. Embodiment 3 In the multi-protrusion belt D shown in FIG.
The multi _- projection belt E shown in FIG.
In this case, both side surfaces 2a, 2a of the band-shaped portion 2 are deviated inward by an angle θ ₂ . The basic structure of the multi-protrusion belts D and E is the same as the multi-protrusion belt A shown in FIG. In addition, multi-protrusion belt B,
Needless to say, a side pressure member can be provided as shown in C. Next, a test comparing the performance of multi-protrusion belts A, D, and E will be described. Here, the belt upper angles α (see FIG. 6) of the multi-projection belts A, D, and E are 20°, 22.5°, and 17.5°, respectively. (vii) Relationship between belt upper angle and slip rate (test method) Using the device shown in Figure 6, a load of F = 90 kg was applied to the idle pulley 33, and each of the multi-protrusion belts A, D, and E was tested. We measured the change in slip ratio when the transmission horsepower was changed. (Test Results) The test results are shown in Figure 12. From FIG. 12, it can be seen that the smaller the belt upper angle α is, the smaller the slip ratio is. (Effects of the Invention) Since the present invention is constructed as described above, the multi-protrusion belt as a whole, including the band-like portion of the multi-protrusion belt, functions like a V-belt and exhibits a wedge effect. It has various practical effects such as increased horsepower, reduced slipping noise caused by low tension, and reduced belt jumping caused by fluctuations in negative fluid.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view of the main part of the power transmission device of the first embodiment, FIGS. 2 and 3 are longitudinal sectional views of the same main part of the second embodiment, and FIGS. 4 and 5 are the longitudinal sectional views of the main part of the power transmission device of the third embodiment, respectively. Fig. 6 is an explanatory diagram of the test equipment, Fig. 7 is a graph showing the relationship between transmitted horsepower and slip ratio, and Fig. 8 is a graph showing the relationship between belt upper angle and lifespan.
A graph showing the relationship with transmitted horsepower, FIG. 9 is an explanatory diagram showing the upper angle and tip angle of the multi-protruded belt, FIGS. 10 and 11 are longitudinal cross-sectional views of the conventional example, and FIG. It is a graph showing the relationship between transmission horsepower and slip ratio when the belt upper angle is changed. A, B, C, D, E...Multi-projection belt, 1...
Power transmission device, 2... Band-shaped portion, 3, 4, 5... Engaging protrusion, 7, 8, 9... Pulley groove, 10... Pulley, 2a... Side surface, 3a, 5a... Outer surface, 1
1, 12... Upper canvas, 13... Upper rubber layer, 1
4... Tensile body, 15... Adhesive rubber layer, 16... Lower rubber layer, 21, 22... Lateral pressure reinforcing material.

Claims (1)

[Scope of Claims] 1. A multi-protrusion belt in which a plurality of engagement protrusions are provided longitudinally protruding from the lower surface of a band-shaped portion, and each engagement protrusion of the multi-protrusion belt is fitted. A device comprising a plurality of pulleys having a plurality of pulley grooves,
The strip portion of the multi-protrusion belt is essentially trapezoidal in cross section, with the tensile member embedded and the upper side larger than the lower side, and the entire multi-protrusion belt is formed in a substantially V shape, while The outer pulley groove surface is formed to extend further in the radial direction than the other pulley groove surfaces and has a shape corresponding to the outer surface of the engagement protrusion and the band-shaped portion, thereby forming a multi-protrusion belt. 1. A power transmission device characterized in that both outer surfaces of the multi-projection belt are substantially entirely in contact with groove surfaces of both outermost pulleys of the pulley at the portion where the belt is wound around the pulley. 2. The multi-protrusion belt is a power source according to claim 1, in which the side surface of the belt-shaped portion and the outer surface of the outermost engaging protrusion are continuous so that they are located on substantially the same straight line in cross section. transmission device. 3 In the cross section of the multi-protrusion belt, the side surface of the belt part is offset from the outer surface of the outermost engagement protrusion by an angle corresponding to -12 to +12% of the tip angle of the engagement protrusion. A power transmission device according to claim 1. 4. The power transmission device according to claim 1, 2, or 3, wherein the belt-shaped portion has a lateral pressure reinforcing material in a portion below the tensile member. 5. The power transmission device according to claim 4, wherein the band-shaped portion has another lateral pressure reinforcing material in a portion above the tensile member. 6 The lateral pressure reinforcing material is a blind in claim 4.
5. The power transmission device according to item 5. 7. The power transmission device according to claim 4 or 5, wherein the lateral pressure reinforcing material is a reinforcing canvas.