JPH0516433Y2 - - Google Patents

Description

[Detailed explanation of the idea]

(Industrial Application Field) The present invention relates to a V-belt used in a dry transmission. (Prior Art) Currently, a belt-type continuously variable transmission is being developed as a transmission for driving an automobile. This belt-type continuously variable transmission is constructed by attaching variable-speed pulleys with variable groove spacing to the drive shaft and driven shaft, and wrapping a V-belt between the two variable-speed pulleys.The groove spacing is adjusted to adjust the rotation pitch. The diameter is changed and the speed is changed steplessly. Furthermore, there are two types of belt-type continuously variable transmissions; one is a wet-type transmission that uses a metal V-belt (see, for example, Japanese Patent Publication No. 55-6783);
The other type is a dry type transmission using a rubber V-belt (see, for example, Japanese Utility Model Publication No. 10408/1983). In general, variable speed pulleys are made of metal materials such as cast iron, steel, and aluminum alloy, so metal V-belts must be used in lubricating oil to prevent friction surface seizure and wear, but rubber V-belts are This is not necessary and is advantageous in terms of cost and maintenance. Incidentally, a transmission for driving an automobile is required to have an extremely high torque transmission capability. For example, when transmitting the maximum torque of a 1000 c.c. engine using a rubber V-belt, the V-belt must withstand a side pressure of around 20 kg/cm ² . However, standard rubber V-belts currently in practical use are usually used at 4 to 5 kg/cm ² or less, and even high-load rubber V-belts have a weight of 10 kg/cm ^{2 .}
The extent is the limit. The reason for this is that the rubber V-belt undergoes buckling deformation under high lateral pressure, and the V-belt generates heat and is destroyed. (Problem to be solved by the invention) Therefore, the applicant developed a V-belt (Japanese Patent Application Laid-open No.
60-49151), such V-belts have a higher transmission capacity than conventional rubber V-belts, but they do not meet strict conditions such as transmitting high torque with small pulleys. However, there is a problem that the force applied to the block becomes excessive, and if the block is made of high-strength resin or hard rubber alone, the strength of the block becomes insufficient, leading to early breakage. Therefore, it is conceivable to bury a metal material as a reinforcing material inside the block for the purpose of reinforcing the block, but as the force applied to the block becomes excessive, it is necessary to increase the thickness of the buried metal material. However, increasing the thickness of the metal material increases the weight of the block, which increases centrifugal tension during belt operation.
Particularly during high-speed operation, the belt generates more heat and the transmission efficiency decreases, resulting in another problem of shortened belt life. Incidentally, while the specific gravity of resin and rubber is 1.0 to 1.6, the specific gravity of metal is 2.7 even if aluminum alloy, a lightweight metal, is used. The present invention was developed in view of the above, and an object thereof is to provide a V-belt for high-load transmission that is lightweight, has excellent torque transmission ability, high speed performance, and has a long belt life. (Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention is constructed by embedding a reinforcing material made of fiber-reinforced plastic in a resin material, which has a higher specific strength than metal materials. It is characterized by what it did. (Example) Hereinafter, an example of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, the V-belt 1 according to the present invention has a pair of endless tension bands 2 and 3.
and a plurality of V blocks 4 which are fixed to the tension bands 2 and 3 at a constant pitch in the longitudinal direction thereof. As shown in FIGS. 3 to 6, the V-block 4 has a plate-shaped reinforcing material 6 made of fiber-reinforced plastic (hereinafter simply referred to as FRP) embedded approximately in the center of a main body 5 made of a resin material. Become. The V-block 4 has an upper beam part 4a, a lower beam part 4b, and a center pillar part 4c that connects them, and these form engagement grooves 7 and 8 in which the tension bands 2 and 3 are engaged. has been done. The reinforcing member 6 also has a shape corresponding to the V-block 4, and has an upper beam portion 6a, a lower beam portion 6b, and a center pillar portion 6c. Near the center portions of the upper and lower parts of the front and rear surfaces of the reinforcing member 6 are recesses 5a, 5b, where parts of the main body 5 are removed.
It is exposed through 5c and 5d. Recesses 5a, 5
b, 5c, and 5d are for regulating the position of the reinforcing member 6 with respect to the main body 5 during block molding. The side surfaces 6d and 6e of the reinforcing member 6 are substantially on the same plane, and are located substantially parallel to the contact surface of the main body 5 with the pulley, that is, the inclined side surfaces 4d and 4e of the V block 4. The tension bands 2 and 3 each have low-stretch core bodies 9 and 9 arranged substantially in the same plane, rubber members 10 and 11 that hold the core bodies 9 and 9, and rubber members 10 and 11 near the upper and lower surfaces. It is composed of buried woven fabrics 12, 12 and 13, 13. In addition, tension band 2,
3, the upper and lower surfaces of each V-block 4 have convex portions provided in the engagement grooves and concave portions that engage with the curved convex surfaces (convex portions 7a, 8a of the engagement grooves 7, 8 and curved convex surfaces 7b, 8b, Only the recesses 3a and 3b of the tension band 3 are shown). ) The material of the main body 5 of the V block 4 is 6,6 nylon, aromatic nylon, thermoplastic resin such as polyethylene terephthalate, phenol resin, hard polyurethane, unsaturated polyester, polyimide, thermosetting resin such as epoxy resin, ebonite, etc. Hard rubber is used alone or in combination with short fibers, fillers, friction modifiers, etc. The reinforcing material 6 embedded in the V block 4 is reinforced with long fibers such as carbon fiber, glass fiber, alumina fiber, and aramid fiber.
Made of FRP. The core bodies 9, 9 constituting the tension bands 2, 3 are made of synthetic fibers such as polyamide, polyester, polyaramid, inorganic fibers such as steel, glass, carbon, etc.
Alternatively, it is made of a blend of these materials and is used as a monofilament or multifilament cord or fabric. The rubber members 10 and 11 are required to be made of a material with a large compressive Young's modulus and excellent wear resistance, and generally known synthetic rubber reinforced with short fibers is used. The woven fabrics 12 and 13 are required to be made of materials with excellent flexibility and abrasion resistance, and are generally made of textile fibers such as cotton, polyamide, polyester, and polyaramid, or blends thereof. Next, a life test conducted on a V-belt of the present invention and a comparative example will be explained. Sample belt In contrast to the V-block, this example uses carbon fiber (PAN type) with an epoxy resin matrix.
A composite reinforcing material (CFRP) is used, and in the comparative example, a reinforcing material made of aluminum alloy (2017T3) is used. Since CFRP can optimally utilize the strength of carbon fibers by changing the fiber orientation direction and configuring it in layers, we performed stress analysis on various laminate configurations and found the optimal laminate configuration for the shape of the reinforcing material. A 2 mm plate was first press-formed and then cut into a predetermined shape. In addition, a 2 mm plate of the Al alloy was punched out using a press. The main body of the V-block is a resin material made by kneading phenolic resin, NBR, vinylon (short fiber), and calcium carbonate in a ratio of 55:10:25:10, and has a bending modulus of elasticity of 350 kgf/mm ² and a bending strength.
It is 13kgf/ ^mm2 . A common tension band was used for each V-belt, and the test was conducted by changing the V-block. The V-block was formed by insert molding using an injection molding machine after adhering a reinforcing material of a predetermined shape. Design dimensions are top width 45.6mm, thickness 4.8mm, belt angle
26°, block mounting pitch 5.0mm, belt circumference 740
mm. The characteristics of the V block used in the test are shown in the table below.

【table】

[Table] Note that the tensile strength and tensile modulus of the present invention examples are with respect to the orientation direction of the uniaxial reinforcing material. Test method In order to evaluate the transmission ability of the belt, as shown in Fig. 7, the drive pulley 21 (pitch diameter 72.2 mm,
rotation speed 2500 rpm) and driven pulley 22 (pitch diameter
152.5 mm) and tested by varying the axial load DW1 so that the slip rate of the belt was 1.8% according to the input torque (test conditions A). In addition, in order to evaluate the high-speed performance of the belt, a drive pulley 31 (pitch diameter
152.5mm) and driven pulley 32 (pitch diameter 72.12mm)
The sample belt 33 _is wound between the
= 100Kg, and the test was conducted by changing the rotation speed of the drive pulley 31 and varying the belt circumferential speed in a no-load state (test condition B). Test results are shown in the table below. Note that the ST value was determined using the following formula. ST value = Tr/r・rθ (Kg/m) Tr…Input torque (Kg・m) r…Pulley radius (m) θ…Belt wrapping angle at drive side pulley (radean)

【table】

[Table] The belt of this example uses CFRP, which has excellent specific strength, so it is lightweight and has excellent high-speed performance.While the comparative example breaks early under high load conditions, it has significantly superior torque transmission ability. Indicated. Note that the belt failure under test condition A was due to damage to the reinforcing material of the block. Further, the ST value of 2800 Kgf/m in the example of the present invention corresponds to the transmission capacity capable of driving an automobile with a displacement of 1500 c.c. when viewed as an automobile belt. The FRP used in the above example has excellent lightness,
Although CFRP has high strength, other FRP reinforced with glass fiber, aramid fiber, alumina fiber, boron fiber, etc. can also be used as long as it has a superior specific strength compared to ultra-strength aluminum alloy. or
It goes without saying that FRP reinforced with cut fibers such as SMC (Sheet Molding Compound) has inferior performance to long fiber reinforced materials, but if used thicker, it can exhibit better performance than aluminum alloy. In the above embodiment, the V block 4 and the tension bands 2, 3 are locked in the longitudinal direction of the belt by the engagement between the convex part of the V block 4 and the recess of the tension bands 2, 3. A concave portion may be formed on the block side, and a convex portion may be formed on the tension band side, and both portions may be engaged and locked, and the method of locking the V block and the tension band is not particularly limited. For example, chemical fixing means using an adhesive may be used. In addition, in the above embodiment, the V-belt 1 is applied to obtain the friction transmission force with the speed change pulley on the side surface of the V-block and the side surface of the tension band. It can be applied to a V-belt that obtains the above-mentioned frictional transmission force, and can also be applied to a type with one tension band. In addition to being used in continuously variable transmissions for automobiles, the V-belt of the present invention can also be applied as a V-belt for continuously variable or step-variable transmissions in vehicles equipped with engines such as agricultural machinery and civil engineering and construction machinery. can.
It is also suitable for high-load V-belts in general industrial machinery driven by electric motors. (Effect of the invention) As mentioned above, the invention has excellent specific strength.
Since FRP is used as a reinforcing material for the block, it is lightweight, has excellent torque transmission ability, and has excellent high-speed performance.

[Brief explanation of the drawing]

Figure 1 is a side view of the V-belt according to the present invention, Figure 2 is a side view of the V-belt according to the present invention;
The figure is a sectional view taken along the - line in Figure 1, Figures 3 and 4 are a front view and side view of the V block, and Figure 5
Figures 6 and 6 are front and side views of the reinforcing material, Figure 7
The figure and FIG. 8 are explanatory diagrams of the test method. 1...V belt, 2, 3...Tension band, 4...V
Block, 4a... Upper beam part, 4b... Lower beam part, 4c... Center pillar part, 5... Main body, 5
a, 5b, 5c, 5d... recess, 6... reinforcing material,
6a... Upper beam part, 6b... Lower beam part, 6c
...Center pillar section.

Claims (1)

[Claims for Utility Model Registration] (1) A belt consisting of a plurality of blocks secured to an endless tension band, the blocks comprising:
A V-belt characterized in that a reinforcing material made of fiber-reinforced plastic, which has a higher specific strength than a metal material, is embedded in a resin material. (2) The V-belt according to claim 1, wherein the reinforcing material is formed by laminating fiber-reinforced plastics reinforced with long fibers. (3) The V-belt according to claim 1 or 2, wherein the fiber-reinforced plastic is reinforced with carbon fibers.