JP4361748B2 - Belt drive - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a belt driving device that applies a driving force to a belt to drive the belt in a belt conveyor, a sheet winding mechanism, and the like.
[0002]
[Prior art]
Conventionally, in the belt conveyor and the sheet take-up mechanism, the following methods as shown in FIGS. 11 and 12 have been used as methods for transmitting the driving force to the belt. For example, by changing the position of the drive roller 102, a tensile tension is applied to the belt 101 to increase the tensile tension, and the friction resistance between the contact surface of the drive roller 102 and the belt 101 that is driven in surface contact with the inner surface of the belt 101 is increased. There is a method of increasing the size and transmitting the driving force of the driving roller 102 to the belt 101 (FIG. 11). When a high driving force is applied to the belt, a plurality of driving rollers are provided, or a pinch roller 103 provided on an axis parallel to the axis of the driving roller is pressed against the belt 101 and the driving roller 102 to A method for increasing the driving force was used (FIG. 12).
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 9-100016 [Patent Document 2]
Japanese Patent Laid-Open No. Sho 46-4072 [Patent Document 3]
Japanese Patent Laid-Open No. 50-97071
However, the conventional method has the following problems. First, in the method of increasing the tension tension of the belt, the tension of the belt must be increased beyond the strength necessary for transporting the load, and the belt must be able to withstand this tension. I had to raise it more than necessary. Further, in the method of providing a plurality of drive rollers, the rotation of the provided drive rollers has to be rotated synchronously, resulting in a large facility and a great cost.
[0005]
Also, with the method of pressing the pinch roller against the belt, parallelism is extremely difficult due to the relationship with the axis of the drive roller, and the pinch roller cannot be pressed evenly, and effective tension cannot be obtained. It was the cause. Further, when the pinch roller is strongly pressed against the driving roller, the pinch roller may be bent (see FIG. 12). Due to the bending of the pinch roller, the central portion of the drive roller cannot be pressurized, and sufficient tensile tension cannot be obtained. This is also a major factor that causes the belt to meander. This problem was particularly noticeable in a wide belt.
[0006]
On the other hand, in order to eliminate the bending of the pinch roller, it is conceivable to use a pinch roller having a large diameter. However, if a pinch roller having a large diameter is used, there is a problem that the winding angle of the belt around the driving roller cannot be sufficiently obtained. there were.
[0007]
Here, the tension and winding angle of the belt will be described with reference to FIG. Here, the case of single drive with one drive roller will be described as an example. The tension required to carry a certain transported object is called effective tension (F _P ) and is expressed by the following equation.
F _P = (61200 · P) / v = F ₁ −F ₂ (N) (Formula 1)
Here, P (kW) is the required power, and v (m / min) is the belt speed. F ₁ (N) is the tension on the tension side of the drive roller, and F ₂ (N) is the tension on the loose side.
Further, the loose side tension (F2) is expressed by the following equation.
F ₂ = F _P / (e ^μθ −1) (Formula 2)
Here, e is the base of the natural logarithm, and μ is a friction coefficient determined by the shape, material and use state of the drive roller. Further, θ (rad) is a winding angle, and is an angle in a range where the illustrated driving roller and the belt are in contact with each other.
[0008]
That is, as shown in Equations 1 and 2, when the winding angle (θ) is increased, the driving force of the driving roller can be applied to the belt more. Therefore, if the winding angle is not sufficient, the driving force cannot be sufficiently transmitted from the driving roller to the belt, and a high driving force cannot be applied to the belt.
[0009]
Further, since the bent pinch roller cannot apply a uniform force to the belt, there are places where the force is applied and places where the force is not applied, and the belt is partially damaged. Further, the belt was damaged by pressing the pinch roller against the belt with a variation in the thickness of the belt and foreign matter.
[0010]
The present invention has been made in view of such a problem, and provides a belt driving device that can provide a necessary effective tension by giving a sufficient driving force to the belt while preventing the belt from being damaged. This is a technical issue.
[0011]
[Means for Solving the Problems]
That is, the present invention relates to a belt, a driving roller that drives the belt, a plurality of nip rolls that rotate in contact with the belt, and a pressure device that presses the nip roll in a direction in which the driving roller and the belt are pressed against each other. And a plurality of the nip rolls are provided on an axis parallel to the axis of the drive roller, and each nip roll is independently rotatable.
[0012]
With the above-described configuration, each nip roll can be pressed independently and a driving force can be applied to the belt, so that an effective tension can be obtained. Also, even if foreign matter adheres to the belt or the thickness varies, only the nip roll at that location moves backward, the other nip rolls can be pressed, and damage to the belt can be prevented at that location. is there. Therefore, the present invention can be suitably used even when the surface of the belt is not smooth, such as when a non-slip protrusion is provided. Since the nip rolls are provided independently, the effective tension of the belt can be easily adjusted by adjusting the number of installations as necessary.
[0013]
Furthermore, since a plurality of the nip rolls are provided independently, it is easy to parallel with the shaft center of the drive roller, and a slight deviation in parallelism does not have a large effect on the whole, and the efficiency of installation work is improved. Can be improved. This effect can be obtained more effectively as the nip roll is thinner. In addition, by adopting the above configuration, the facility can be made extremely compact as compared with the conventional method.
[0014]
Here, the pressurizing device may be any device that can apply a predetermined pressure to the belt via the nip roll, and examples thereof include an air cylinder, a spring, a hydraulic cylinder, and a rubber material. The pressurizing device only needs to be able to press each of the nip rolls independently, and may be provided independently for each of a plurality of nip rolls, or one unit or a plurality of units press a plurality of nip rolls. But it ’s okay. However, by providing the pressurizing device independently for each nip roll, it is easy to adjust the number of nip rolls installed and the pressure.
[0015]
It is desirable that the pressure device according to the present invention presses the nip roll with a constant pressure without being affected by a relative distance from the belt. By being able to press at a constant pressure without being affected by the relative distance to the belt to be pressed, for example, when a foreign object adheres to the belt, the constant pressure can be applied even if the distance from the belt varies. Thus, it is possible to reliably apply a driving force to the belt. An example of such a pressurizing device is an air cylinder that is easy to adjust the pressure and has excellent ease of escape when a foreign object is bitten.
[0016]
In addition, the nip roll of the belt driving device according to the present invention is preferably provided on a plurality of shafts parallel to the shaft center of the driving roller.
[0017]
The plurality of nip rolls are arranged on an axis parallel to the axis of the drive roller. By providing a plurality of rows of this arrangement, the effective tension of the belt can be easily adjusted. That is, as described above, since the effective tension of the belt varies depending on the winding angle (θ), the effective tension of the belt can be easily adjusted by changing the installation location of the nip roll.
[0018]
In the belt drive device according to the present invention, a plurality of the nip rolls are arranged at intervals in the circumferential direction of the drive roller, and a total effective tension value of the belt generated by the nip rolls arranged on the same circumference. However, it is desirable that the value is the same on any circumference.
[0019]
With the above-described configuration, uniform effective tension can be generated over the entire width of the belt, so that the distortion and meandering of the belt can be prevented. Furthermore, since the belt can be pressed evenly, it is possible to prevent the belt from being damaged and painful, and can be suitably used for a thin belt or a cross-shaped belt that is generally easily damaged.
[0020]
Furthermore, it is desirable that the nip rolls are arranged in a staggered manner in the parallel direction of the axis of the drive roller and in the circumferential direction of the drive roller. With the above configuration, since adjacent nip rolls are arranged with a gap therebetween, constant pressure can be applied without interfering with each other. If this staggered arrangement is arranged so that it is in line with the width of the nip rolls arranged in adjacent rows, there will be a problem that the joints of the nip rolls are generated on the belt and the joint parts are damaged. For this reason, it is desirable to arrange at a position slightly overlapping with the width of the nip rolls arranged in adjacent rows.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of a belt driving device according to the present invention will be described in detail with reference to the drawings.
[0022]
FIG. 1 is a schematic configuration diagram of a belt driving device according to the present embodiment, and FIG. 2 is a view taken in the direction of arrow P in FIG. The belt driving device is configured to contact a belt 1 that conveys a load in the X direction, a driving roller 2 that wraps the belt 1 to give a driving force, a receiving roller 3 that serves as a belt receiver, and the belt 1 to rotate and press. A nip roll 4 that presses the nip roll 4 in a direction in which the drive roller 2 and the belt 1 are in pressure contact with each other.
[0023]
As can be clearly seen from FIGS. 1 and 2, the nip rolls 4 are arranged in two rows on two axes in the Y direction parallel to the axis 2 a of the drive roller 2, and the air cylinder 5 is provided for each nip roll 4. Are provided independently. The nip roll 4 and the air cylinder 5 arranged in this way are independently rotatable and pressurizable, and the air cylinder 5 is arranged so as to be pressurized in the direction of the axis 2 a of the drive roller 2.
[0024]
In this embodiment, an air cylinder is selected as the pressurizing device from the viewpoint of ease of adjusting pressure and ease of escape when a foreign object is bitten, but a spring, a hydraulic cylinder, rubber or the like may be used. good.
[0025]
The nip roll is made of urethane rubber, but it is desirable to select an appropriate material in consideration of usage conditions such as pressure resistance and oil resistance. In addition, since the belt drive device according to the present embodiment needs to be pressurized in the radial direction, even if the friction coefficient of the nip roll surface is increased, the relationship with the effective tension of the belt is not affected. There is no need to consider the coefficient of friction.
[0026]
The driving roller 2 has a rubber lining in order to increase the friction coefficient (μ) because the driving force applied to the belt 1 varies depending on the friction coefficient (μ) of the surface as shown in the above-described (Equation 2). is doing. This coefficient of friction (μ) varies depending on the use state such as a dry state.
[0027]
In the belt driving device according to the present embodiment, the belt 1 is wound around the driving roller 2, the air cylinder 5 presses the nip roll 4, and the belt 1 and the driving roller 2 are pressed against each other. In this device, the driving force is transmitted to the belt 1 and a large effective tension can be generated in the belt.
[0028]
Next, adjustment of the effective tension of the belt in the belt driving device configured as described above will be described. First, the nip roll 4 will be described in detail. The nip rolls 4 are arranged in a staggered manner and are in contact with the belt 1. By adopting the staggered arrangement, when the belt moves in the X direction, it is possible to apply pressure evenly over the entire width of the belt. Further, since the staggered arrangement can be arranged with an interval from the adjacent nip rolls 4, it is easy to secure an installation space for an air cylinder or the like that is a pressure device.
[0029]
FIG. 3 is a partially enlarged view of FIG. The nip rolls 41 and 42 arranged in two rows on two axes parallel to the Y direction are arranged at intervals in the Y direction. In the X direction, the nip rolls 42 in the other row are positioned in the interval between the nip rolls 41 arranged in one row. The belt contact paths in one row of nip rolls 41 and the other row of nip rolls 42 slightly overlap. By arranging the nip rolls 41 and 42 in this way, it is possible to prevent the occurrence of streaking of the nip roll and to press the belt uniformly over the entire width of the belt.
[0030]
The air cylinder 5 provided for each nip roll 4 is pressure-adjusted by a single air pressure regulator (not shown) so that the effective tension is constant over the entire width of the belt. The effective tension can be adjusted by adjusting the capacity of the air cylinder based on the diameter of the air cylinder and the angle of the pressure contact position with respect to the drive roller. Furthermore, the effective tension of the belt can be adjusted by adjusting the arrangement position of the nip roll in relation to the winding angle (θ). That is, the effective tension of the belt can be adjusted by selectively adjusting the diameter of the air cylinder, the angle of the pressure contact position with respect to the drive roller, and the position of the nip roll.
[0031]
Here, the case where the nip rolls are arranged on four axes parallel to the Y direction will be described in detail. FIG. 4 is a schematic side view of a belt driving device in which nip rolls are arranged in four rows in parallel with the Y direction, and FIG. 5 is a diagram showing the arrangement of nip rolls in the belt driving device of FIG. Since the configuration other than the arrangement of the nip roll 4 is the same as that of the belt driving device described above, the description thereof is omitted.
[0032]
The nip rolls 4 are arranged in four rows in parallel with the Y direction, and the nip rolls 41, 42, 43, 44 in each row are arranged at intervals. On the other hand, in the X direction, X1 to X25 are arranged.
[0033]
Since the belt 1 moves in the X direction, in order to press the entire belt width evenly, the total value of the effective tensions of the belts generated by the individual nip rolls on the X row may be the same value in all rows. . That is, for example, the total value of the effective tension of the belt generated by the nip rolls 42 and 44 on X1 is set to the same value as the total value of the effective tension of the belt generated by the nip rolls 41 and 43 on X2. Thus, by making the effective tension of the belt the same value in all the X rows, the belt can obtain a uniform tension over the entire width. In this embodiment, the nip rolls are arranged in two rows and four rows, but when the nip rolls are arranged in a plurality of rows, the effective tension of the belt can be adjusted in the same manner.
[0034]
In the present embodiment, as a means for adjusting the effective tension, it is performed by changing the capacity of the air cylinder (air cylinder diameter), and a plurality of air cylinders are adjusted by a single air pressure regulator. It was. However, the effective tension may be adjusted by installing an air pressure regulator in each air cylinder without changing the capacity of each air cylinder.
[0035]
Next, as other embodiments, examples of arrangement of nip rolls in the belt driving device are shown in FIGS. The arrangement other than the arrangement of the nip roll 4 is the same as that of the above-described embodiment, and the description is omitted.
[0036]
In FIG. 6, the nip rolls 4 are arranged in a line without any gap. Although it can be pressed over the entire width of the belt, considering the installation of the air cylinder 5 and the like, there is no gap between the adjacent nip rolls 4 and the installation is restricted. It is desirable to place a gap between the nip rolls 4 adjacent to each other.
[0037]
If the required effective tension cannot be obtained with the one row arrangement, the nip rolls may be arranged in two rows as shown in FIG. In this case, the nip roll 4 is disposed over the entire width of the belt and can be pressed over the entire width of the belt.
[0038]
If the necessary effective tension cannot be obtained even with the two-row arrangement, as shown in FIG. 9, a four-row zigzag arrangement may be used. The pressing by the nip roll 4 is strengthened, and the effective tension can be increased. The staggered arrangement may be a deformed staggered pattern as shown in FIG. In the embodiment, as described above, it is desirable to adjust the position of the nip roll, the pressure of the air cylinder, etc. so that the same effective tension is generated over the entire belt width.
[0039]
【The invention's effect】
As described above, according to the present invention, each belt can be pressed by the individual nip rolls in the direction in which the belt and the driving roller are pressed, so that sufficient driving force can be applied to the belt while preventing damage or breakage of the belt. . In addition, since a plurality of nip rolls are independent of each other and can be easily adjusted, it is possible to obtain an effective tension as necessary.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a belt driving device according to an embodiment.
FIG. 2 is a view taken in the direction of arrow P in FIG.
3 is a partially enlarged view of the belt driving device shown in FIG. 2. FIG.
FIG. 4 is a schematic configuration diagram of a belt driving device in which nip rolls are arranged in a staggered manner.
FIG. 5 is an explanatory diagram of arrangement of nip rolls in the belt driving device shown in FIG. 4;
FIG. 6 is a perspective view showing an example of arrangement of nip rolls.
FIG. 7 is a perspective view showing an arrangement example of nip rolls.
FIG. 8 is a perspective view showing an example of arrangement of nip rolls.
FIG. 9 is a perspective view showing an example of arrangement of nip rolls.
FIG. 10 is a perspective view showing an example of arrangement of nip rolls.
FIG. 11 is a schematic view of a conventional belt driving device.
FIG. 12 is a schematic view of a conventional belt driving device.
FIG. 13 is an explanatory diagram of a winding angle in the belt driving device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Belt 2 Drive roller 3 Receiving roller 4 Nip roll 5 Air cylinder 101 as a pressure device Belt 102 Drive roller 103 Pinch roller

Claims (6)

Belt,
A driving roller for driving the belt;
A receiving roller serving as a belt receiver for winding the belt around the drive roller;
A plurality of nip rolls rotating in contact with the belt, the plurality of nip rolls pressing the belt wound around the drive roller by the receiving roller against the drive roller ;
A pressure device that presses each of the nip rolls in a direction in which the driving roller and the belt are in pressure contact with each other,
The belt drive device according to claim 1, wherein a plurality of the nip rolls are provided on an axis parallel to the axis of the drive roller, and are independently rotatable.   The belt driving device according to claim 1, wherein the pressure device is provided independently for each of the nip rolls.   The belt driving device according to claim 1, wherein the pressure device presses the nip roll with a constant pressure without being affected by a relative distance to the belt.   The belt driving device according to any one of claims 1 to 3, wherein the nip roll is provided on a plurality of shafts parallel to an axis of the driving roller.   The nip rolls are arranged in a plurality of rows at intervals in the circumferential direction of the drive roller, and the total value of the effective tension of the belt generated by the nip rolls arranged on the same circumference is on any circumference. The belt driving device according to any one of claims 1 to 4, wherein the belt driving device also has the same value.   The belt driving apparatus according to claim 5, wherein the nip rolls are arranged in a staggered manner in a parallel direction of an axis of the driving roller and a circumferential direction of the driving roller.

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