JPH0612267Y2 - Flat belt - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a flat belt in which a circumferential groove extending in the belt longitudinal direction is formed on a lower surface side of a belt base belt which comes into contact with a pulley.

(Prior Art) Conventionally, a flat belt has a structure in which glued canvas is adhered to the entire outer cover of the belt base or the pulley contact surface, or a single rubber is attached to the core wire, and is used for light load transmission. (See, for example, Japanese Utility Model Publication No. 50-43634).

(Problems to be solved by the invention) Therefore, when used at high torque, the core wire sinks and the deformation due to shearing force is large, so that high load transmission cannot be performed.

That is, when there is only a compression rubber layer having low elasticity on the lower side of the cord layer, when high load transmission is performed, as shown in FIGS. 17 and 18, between the cord a and the pulley b. The compressive force acts and the compressed rubber layer c is largely deformed. As a result, the core wire a largely sinks (see the chain line in FIG. 17), and in the length direction, a large shear strain γ is caused by the shear stress τ. As a result, the power transmission capability is reduced, heat generation is increased, and the service life is reduced.

Further, the surface pressure P generated in the compression rubber layer c due to the compression force between the core wire a and the pulley b is not uniform in the belt width direction,
A large surface pressure Pmax is generated for each core wire a, and the slippage between the compression rubber layer c and the pulley b partially accelerates wear.

Therefore, a circumferential groove extending in the longitudinal direction of the belt is formed on the lower surface of the belt base belt in which the spiral endless core wire is embedded so as to contact the pulley, so that the distribution of the surface pressure is made uniform and the transmission capability is improved. A flat belt was conceived and applied separately (Actual application Sho 6
3-107081), in such a structure, since the circumferential groove penetrates the cord layer in the belt thickness direction, the shear force generated in each friction transmission surface divided by the circumferential groove is Vertical cracks may occur in the circumferential groove due to differences or the like. This tendency is particularly great when used for high load transmission.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a flat belt as described above, which prevents vertical tearing during use under high load conditions and enables high load transmission. To do.

(Means for Solving the Problem) The invention of claim (1) is characterized in that the belt base has a core layer in which endless cores are embedded in a spiral shape, and the bottom surface contacts the pulley of the belt base. Assuming a flat belt having a circumferential groove extending in the belt longitudinal direction on the side, a rubbing canvas layer with sudar records arranged in the belt width direction on the upper surface side, and a surface rubber layer having a high friction coefficient on the lower surface side. Respectively,
Further, a compression rubber layer made of highly elastic rubber is interposed between the core wire layer and the surface rubber layer, and the circumferential groove is configured to penetrate the core wire layer in the belt thickness direction.

The invention of claim (2) is the device of claim (1), wherein the diameter of the sudare record of the overhanging canvas layer is 0.75 mm or less.

According to the invention of claim (3), in the invention of claim (1), a long fiber mixed layer is used instead of the sudare canvas layer.

(Operation) According to the invention of claim (1) and the invention of claim (3), since the compression rubber layer below the core wire layer is made of high elastic rubber, even if a compression force is applied from the core wire, It does not deform and prevents the core from sinking. Further, since the surface rubber layer having a high friction coefficient makes the compressive force with the pulley substantially uniform, the shear strain is reduced by the shear stress (see FIGS. 2 and 3). Also, due to the sudare canvas layer, when it is used for a pulley with a crown, thrust of the orbiting groove is pushed up by the action of thrust force, and vertical tearing due to concentration of shearing force due to the difference in power transmission between both sides of the orbiting groove is caused. Effectively suppressed.

In particular, according to the invention of claim (2), the effect of suppressing the occurrence of cracks due to such a dull canvas layer becomes remarkable.

Embodiment An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 1 showing the overall structure of a flat belt, reference numeral 1 is a flat belt, and a belt base band 2 thereof has a cord layer 4 in which a cord 3 is embedded in a spiral shape, and contacts a pulley. A circumferential groove 5 extending in the belt longitudinal direction is formed on the lower surface side.

Further, the flat belt 1 is formed by laminating a sudare canvas layer 7 (nylon cords, 56 pieces / 5 cm) having sudare records 6 arranged in the belt width direction on the upper side of the cord layer 4, and the short fibers 20 on the lower side. Compression rubber layer 8 (E = 430 × 10 ⁶ dyn / cm ² , μ =
0.5) and a surface rubber layer 9 (E = 310 × 10 ⁶ dyn / cm ² , μ = 0.
And 9) are sequentially stacked from the upper side.

According to this structure, as shown in FIGS. 2 and 3, the compressed rubber layer 8 below the core wire layer 4 does not deform even when receiving a compressive force from the core wire 3, and the core wire 3 is not deformed. Since the surface rubber layer 9 makes the compressive force with the pulley 10 substantially uniform, the shear strain γ due to the shear stress is reduced. Here, the reason why the lower side of the core layer 4 is not a compressed rubber layer made of a highly elastic compressed rubber is that if this is done, the coefficient of friction will be low and there will be no deformation, but the sliding power transmission capability will be early. I won't up. Therefore, the compression rubber layer 8 and the surface rubber layer 9 are laminated below the core layer 4.

Further, because of having the circumferential groove 5, as shown in FIGS. 4 and 5, the thrust of the thrust force Fc on the crown 11a of the pulley 11 causes the circumferential groove portion to be pushed up, and
A slight difference in power transmission Fs1-Fs2 causes vertical tearing due to the concentration of shearing force. To prevent this, concentration of these forces is prevented, and in order to reinforce, there is a widthwise direction on the upper surface. The Sudare canvas layer 7 in which the Sudari records 6 are arranged is laminated.

Next, the test results of the flat belt 1 will be described.

(1) Longitudinal tearing test <Test belt> The flat belt 1 of the present invention shown in FIG. 1, the compressed rubber layer 23 below the core layer 22 (E = 250 × 10 ⁶ dyn / cm ² , μ =
0.8) is made of rubber only, and the upper rubber layer 24 and the upper canvas layer 25 (cotton (CC-10)) 70 are embedded above the core layer 22.
Flat belt 21 of Comparative Example 1 (see FIG. 6) in which (70 × 5 × 5 cm square) are laminated, and the flat belt 31 of Comparative Example 2 (the first belt layer 21 of Comparative Example 1 excluding the upper canvas layer 25) 7
(See the figure). The belt dimensions are all
The belt width is 25.4 mm, the belt thickness is 3.56 mm, and the width of the circumferential groove is 1 mm.

<Testing Device> As shown in FIGS. 8 and 9, a driving side pulley 41 (diameter 100 mm, 0 PS) and a driven side pulley 42 (diameter 10
(0 mm, 2600 rpm), the test belt 43 is wound around the driven belt 42, and a running test is performed while applying an axial load of W = 4500 kgf to the driven pulley 42. When a crack penetrates from the back of the belt to the back of the circumferential groove, a vertical tearing occurs. It was determined. Each of the pulleys 41, 42 has a crown 41a, 4 with a diameter of 100 mm.
1a (42a, 42a) is formed.

(2) Friction coefficient measurement test <Test belt> Same as the vertical tear test.

<Testing device> As shown in FIG.
(Diameter 60 mm, number of revolutions 45 rpm), the load cell 53 was connected to one end while the load DW was applied to the other end, and the friction coefficient μ was determined based on the following formula.

μ = [2 × Ln (Rod cell load / DW)] / π (3) Offset test <Test belt> As shown in FIG. 11, a flat belt 6 having no circumferential groove.
1 and the upper surface layer 62 was a canvas layer A, a sheet B not provided, a sloppy canvas C, and a long fiber mixed layer D.

<Testing device> As shown in FIG. 12, the drive pulley 71 (diameter 100 m
m, 360 rpm) and the driven pulley 72 (diameter 100 mm) are wound around the test belt 73, and the driven pulley 72 is F = 50 kg.
A running test was conducted in the state of being pulled at f, and the deviation was checked.

As shown in FIG. 13, each pulley 71, 72 has a crown 71a, 72a having a width of 50 mm and a radius of 450 mm.

<Test Results> As is apparent from the following table, it is understood that the vertical tear can be prevented by providing the canvas layer 25 and the sloppy canvas layer 7 on the upper surface of the belt. However, as shown in FIG. 14, the canvas layer is provided. In this case, the amount of meandering becomes extremely large, which is not desirable as a belt. Therefore, as in the example of the present invention, the sloppy canvas layer 7
It turns out that

Further, in this case, as shown in FIG. 15, it is desirable that the diameter of the Suda record 6 of the Sudare canvas layer 7 is 0.75 mm or less. Note that the crack generation index means that the smaller the index value, the earlier the cracks are generated.

In the above-mentioned embodiment, the sloppy canvas layer 7 is provided on the upper side of the belt base belt 2.
However, as in the flat belt 81 shown in FIG. 16, a long fiber mixed rubber layer 82 may be used instead of the sloppy canvas layer 7.

(Effects of the device) Since the devices of claims (1) and (3) are configured as described above, the compression rubber layer and the sudare canvas layer or the long fiber mixed layer do not increase the meandering amount without increasing the meandering amount. It is possible to prevent the wire from sinking and cracks in the circumferential groove to achieve high load transmission.

In the invention of claim (2), since the diameter of the Suda record of the sloppy canvas layer is 0.75 mm or less, the back surface crack can be effectively suppressed by the Suda record of the Sudare canvas layer.

[Brief description of drawings]

1 to 16 show an embodiment of the present invention, FIG. 1 is a sectional view of a flat belt, FIGS. 2 to 5 are explanatory views of the action, and FIGS. 6 and 7 are comparative examples. Sectional views of the test belt, FIGS. 8 and 9 are explanatory views of the vertical tear test device, FIG. 10 is an explanatory view of the friction coefficient measuring test device, and FIG. 11 is a sectional view of the test belt of the one-sided test, 12 and 13 are sectional views of the one-sided test apparatus, FIGS. 14 and 15 are explanatory diagrams of test results, and FIG. 16 is a sectional view of a modified example. 17 and 18 are explanatory views of the operation of the conventional flat belt. 1, 81 ... Flat belt, 2 ... Belt base band, 3 ... Core wire, 4 ... Core wire layer, 5 ... Circular groove, 6 ... Sudare record, 7 ... Sudare canvas layer, 8 ... ... compressed rubber layer, 9 ... surface rubber layer, 82 ... long fiber mixed rubber layer

Claims (3)

[Scope of utility model registration request] 1. A belt base band has a core wire layer in which endless core wires are embedded in a spiral shape, and a circumferential groove extending in the longitudinal direction of the belt is formed on the lower surface side of the belt base band that contacts the pulley. In the flat belt, the upper surface side has a rubbing canvas layer in which the Suda records are arranged in the belt width direction, the lower surface side has a surface rubber layer having a high friction coefficient, and the core wire layer and the surface rubber layer are further provided. A flat rubber belt, in which a compression rubber layer made of high-elasticity rubber is interposed between, and the circumferential groove extends through the core layer in the belt thickness direction. 2. The diameter of the Suda record in the Sudare canvas layer is 0.7.
The flat belt according to claim 1, which has a thickness of 5 mm or less. 3. A belt base belt has a core wire layer in which endless core wires are embedded in a spiral shape, and a circumferential groove extending in the belt longitudinal direction is formed on the lower surface side of the belt base belt that contacts the pulley. In this flat belt, a long fiber mixed rubber layer is provided on the upper surface side, and a surface rubber layer having a high friction coefficient is provided on the lower surface side. Further, a high elastic rubber is formed between the core layer and the surface rubber layer. A flat belt, wherein a compressed rubber layer is provided, and the circumferential groove extends through the cord layer in the belt thickness direction.