JPH04246042A - belt conveyor device - Google Patents

Abstract

PURPOSE:To reduce any possible damage to the side edge part of a belt at time of correcting a meandering motion in the belt as well as to facilitate the meandering correction of the belt, in a belt conveyor device conveying paper or the like. CONSTITUTION:This conveyor device is so constituted that a central part of a support frame 15 supporting a driven roller 14 free of rotation is held in a seesaw type of this roller 14 with a supporting means 22 interposed with a spring 21 pressurizing an endless belt 20 being rolled on this driven roller 15, and thereby any meandering of the endless belt 20 is smoothly corrected.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt conveying device using a wide endless belt used for conveying paper in a copying machine or the like.

0002

[Prior Art] As a method for preventing shifting of an endless belt stretched between rollers, in the case of a narrow endless belt, it is relatively easy to prevent shifting by providing flanges at both ends of the rollers. can. However, in the case of a wide endless belt, the shearing force is large, and it is difficult to prevent the shearing by the method described above. Furthermore, when deviation occurs in a wide endless belt, the side edges of the endless belt rub against the flanges with strong force, causing damage to the periphery of the endless belt. In particular, in the case of wide elastic endless belts, the side edges contact the flanges with strong force and the endless edges roll up, resulting in excessive internal stress at the side edges of the endless belt, resulting in tearing or permanent deformation. It suffered a great deal of damage. For this reason, there is an increasing demand for a belt conveying device that has less damage to the endless belt and is inexpensive.

Conventionally, this type of belt conveying device was disclosed in Japanese Patent Application Laid-open No. 5
A configuration as shown in Japanese Patent No. 8-95016 was common.

The configuration will be explained below with reference to FIG. 13. As shown in the figure, a shaft rod 43 supported by a fulcrum load 42 along a horizontal plane is provided around a sleeve 41 formed at the center in the longitudinal direction.
A feed roller 44 is rotatably attached to the feed roller 44, and the endless belt 45 is rotatably attached to both ends of the shaft rod 43 and has a circumferential surface that comes into contact with the side edges of an endless belt 45 detached from the feed roller 44. A correction piece roller 47 having a wheel portion 46 is provided, and the traveling wheel portion 46 is slidably provided on a rail base 48 having a predetermined length extending in the running direction of the endless belt 45.

In the above configuration, meandering occurs in the endless belt 45 for some reason, and the endless belt 45 deviates from the normal running position of the feed roller 44.
5 comes into pressure contact with the circumferential surface of the correction piece roller 47, the correction piece roller 47 with which the side edge of the endless belt 45 is in pressure contact is forcibly rotated, and the correction piece roller 47 connects the traveling wheel portion 46 and the rail 48. By sliding the shaft rod 43 through the endless belt 45
The endless belt 45 is tilted from a position perpendicular to the running direction to correct the deviation of the endless belt 45.

[0006]

[Problems to be Solved by the Invention] In such a conventional belt conveying device, the side edge of the endless belt 45 comes into pressure contact with the correction piece roller 47, so that the feed roller 44 is tilted and one piece of the endless belt 45 is moved. Since the offset is corrected, a strong force is applied to the side edges of the endless belt 45.
The endless belt 45 is frequently damaged, and the endless belt 45 must be replaced frequently, which poses a problem of time consuming and high cost.

The present invention solves the above-mentioned problems, and provides an inexpensive belt conveying device that eliminates the force acting on the side edges of an endless belt, reduces damage to the endless belt, makes it easy to correct belt deviation, and is inexpensive. The purpose is to provide

[0008]

[Means for Solving the Problems] In order to achieve the above object, the belt conveying device of the present invention has a first means that rotatably supports a driving roller at one end and a driven roller is provided at the other end. a transport unit main body, a support frame that rotatably supports the driven roller, a support means whose one end is connected to the center of the support frame and whose other end is connected to the transport unit main body, and the drive roller and the driven roller. an endless belt wound around a roller, and the supporting means is connected to the transport unit main body with the longitudinal center of the driven roller as a fulcrum via a spring that applies a force in the feeding direction of the endless belt. The structure is such that the driven roller is supported in a swingable manner.

[0009] A second means is such that a plurality of support means for swingably supporting the driven roller are provided, and these support means are provided near the center of the main body of the conveyance unit.

[0010] Furthermore, the third means is configured such that at least one of the supporting portion of the supporting means on the transport unit main body side and the connecting portion on the support frame side is movable.

The fourth means includes a flange provided at the end of the driven roller, a spring provided between the flange and the side edge of the endless belt wound around the driven roller, and a compression degree of the spring. The present invention is configured to include a detection means for detecting, and to detect deviation of the endless belt.

0012

[Function] With the configuration of the first means described above, in the belt conveying device of the present invention, when the endless belt tries to displace due to some reason, the driven roller supported in a see-saw shape with tension at the center The endless belt is automatically tilted around the center of the driven roller as a fulcrum so that the displaced end of the endless belt is positioned ahead of the other end, and the belt's traveling vector is accordingly tilted. It returns to its normal state, and the tilt of the driven roller is also restored.

Furthermore, with the configuration of the second means, even when the width of the endless belt is widened and the driven roller is supported at a plurality of locations, the same effect as the first means can be achieved by gathering the plurality of support means near the center. This will bring about

Furthermore, the configuration of the third means increases the degree of freedom of the support portion of the support means, and the driven roller can smoothly displace and follow the displacement of the endless belt due to its meandering, so that meandering correction can be carried out quickly. becomes.

Furthermore, with the configuration of the fourth means, the displacement of the endless belt can be detected by detecting the degree of compression of the spring, so the displacement state of the endless belt can be measured numerically, and the displacement of the driven roller can be easily adjusted. Become.

[0016]

Embodiments (Embodiment 1) An embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

As shown in the figure, a plurality of developing devices 1 are provided,
When an electrostatic latent image is formed on the photoreceptor 2, the developer 1 is activated to develop it with toner. Continuous image processing is performed so that the paper 4 is transferred to the paper 4 via a plurality of rollers 5 at the transfer conveyance section 6, and then the paper 4 is sent to the next fixing section 7 and is ejected to the outside via the paper ejection roll 8. A forming device is configured.

The present invention relates to a belt conveyance device in the transfer conveyance section 6, and details thereof will be explained below.

A pair of side plates 9 are supported by a plurality of stays 10 at intervals, and a drive roller 13 is rotatably provided at the front end of a conveyance unit main body 12 in which a plurality of auxiliary rollers 11 are provided between the side plates 9. On the other hand, the driven roller 14 is rotatably supported by a support frame 15, and a support frame side support part 16 is provided at the longitudinal center of the support frame 15.
6 through a pin 17, and the other support rod 18 is provided on a stay 10 provided on the transport unit main body 12 so as to be slidable back and forth through a bearing 19. An endless belt 20 is always wound between the drive roller 13 and the driven roller 14 between the frame 15 and the stay 10.
A spring 21 is provided so as to pressurize the supporting means 22.
It consists of The shaft portion 23 of the driven roller 14 rotatably supported by the support frame 15 is engaged in a long groove 25 of a receiving portion 24 provided at the rear end of the transport unit main body 12 so as to be movable back and forth.

Further, flanges 26 are provided at both ends of the driven roller 14, and a flanged washer 27, which the side edge of the endless belt 20 comes into contact with, is rotatably provided on the driven roller 14. There is a compression spring 2 between 27
There are 8.

The mechanism by which belt snakes occur in the belt conveying device having the above structure will be explained below with reference to FIGS. 6 and 7.

For example, if LL...Left end circumference LR...Right end circumference PL...Left end tension when attached to the traveling mechanism PR...Right end tension when attached to the traveling mechanism, each tension is applied. The amount of elongation of the belt in this state is given by ΔLL=εLL PL ΔLR=εLR PR.

At this time, if PR is larger than PL by ΔP (initial circumference LL=LR), ΔLR=εLR PR=εLR(PL+ΔP)=εL
R PL + εLR ΔP = ΔLL + εLR ΔP, and the right end where the tension is greater by ΔP is εLRΔP
However, the circumference also becomes longer.

In other words, if the roller diameters are the same at both the left and right ends, there will be a delay of εLRΔP per revolution of the belt wound around the roller, and the meandering angle Q=tan-1(εLRΔ
P/B) B: Belt width.

In other words, when a tension difference occurs, meandering occurs in which the belt's traveling vector is tilted (tilt angle θ) by the difference between the larger and smaller tension forces.

In order to prevent this, it is necessary to create a structure in which the circumferential length does not change or decreases even if the tension increases relative to the opposite end.

Therefore, the belt conveying device of the present invention is configured in a seesaw type with the center of the driven roller as a fulcrum, and the one with greater tension is pulled toward the driving roller and the circumference becomes shorter. The operation will be explained below.

If the endless belt 20 tries to move to the right side with respect to the driven roller 14 for some reason as shown in FIG. 8, the center of the support frame 15 that rotatably supports the driven roller 14 is supported by the supporting means 22 so as to be able to swing freely through the spring pressure of the spring 21, and the tension (a) of the driven roller 14 is always provided at the center position. When the center of moves, the tension at the center of the driven roller 14 (a) and the reaction force at the center of the endless belt 20 (b)
The position of the driven roller 14 shifts, and a difference occurs in the tension that was applied uniformly to the right and left ends of the driven roller 14, and the driven roller 14 uses the support means 22 as a fulcrum, so that the right side of the driven roller 14 retreats and the left side moves forward. In other words, the right end of the driven roller 14 moves toward the driving roller 13, and the circumference of the right side of the endless belt 20 becomes shorter, and the endless belt 20, which was biased toward the right, is pulled toward the left. It is sent. Through such an operation, the endless belt 20 is driven at a normal running position.

Further, the driven roller 14 is
Since the support frame 15 which rotatably supports the endless belt 20 is provided in pressure contact with the endless belt 20 by the spring pressure of the spring 21 provided on the support means 22, the endless belt 2
The degree of contact of the driven roller 14 with respect to 0 is increased, the displacement of the endless belt 20 acts quickly on the driven roller 14, and the supporting means 22 can smoothly displace the driven roller 14.

Furthermore, when the endless belt 20 shifts to one side, the compression spring 28 on the one side of the endless belt 20 is compressed, and the spring pressure of the compression spring 28 tries to return the endless belt 20 to its normal running course. It acts to return the endless belt 20 to its normal state, and can supplement the running adjustment of the endless belt 20.

Note that the position where the spring pressure of the compression spring 28 is applied to the side edge of the endless belt 20 is at the position where it is wound around the driven roller 14, so the endless belt 20
The side edge portion of the endless belt 20 is less distorted than when pressure is applied at a position where it is not wound around the driven roller 14, and the side edge portion of the endless belt 20 is less damaged.

(Embodiment 2) Embodiment 3 of the present invention will be described below with reference to FIGS. 9 and 10.

Embodiment 2 is provided with a plurality of supporting means in Embodiment 1, and the same parts as in Embodiment 1 are given the same reference numerals and detailed explanations will be omitted.

As shown in the figure, the same supporting means A30 and supporting means A'30' are provided near the center of the supporting frame 15 between the supporting frame 15 that rotatably supports the driven roller 14 and the stay 10. It is something that

The operation of the above configuration will be explained with reference to FIG. If the moment of the support means A is F1, the moment of the support means A' is F2, and ΔF=F1-F2, then the moment M=γ×ΔF, and since γ is the distance from the center of the support frame 15, the moment can be expressed as It can be seen that in order to make it smaller, γ can be made smaller.

That is, the distance γ from the center of the support frame 15
Support means A30 and support means A'30 in a small state of
By providing ', the same effect as in the first embodiment is brought about.

(Embodiment 3) Embodiment 3 of the present invention will be described below with reference to FIG. 11.

Embodiment 3 provides flexibility in supporting the stay side of the support means in Embodiment 1, and the same parts as in Embodiment 1 are given the same reference numerals and detailed explanations will be omitted.

As shown, the shaft 18 of the support means 22
The alignment bearing 3 is placed on the stay 10 side that slidably supports the
5.

With the above configuration, the shaft rod 18 is not only slidably supported but also swingably supported by the alignment bearing 35, so that the driven shaft 18, which is rotatably supported by the support frame 15, The rollers 14 smoothly follow the deviation of the endless belt 20, and the running of the endless belt 20 is always maintained normally.

(Embodiment 4) Embodiment 4 of the present invention will be described below with reference to FIG. 12.

[0042] The same parts as in the first embodiment are given the same numbers and detailed explanations will be omitted.

As shown in the figure, there are flanges 26 provided at both ends of the driven roller 14, and flanged washers 27 that come into contact with the side edges of the endless belt 20 wound around the driving roller 13 and the driven roller 14. A compression spring 28 is provided between the
Compression spring 2 that is compressed when the endless belt 20 shifts to one side
A detection means 36 such as a scale measurement for measuring the compression width of 8 is provided.

Note that the detection means 36 may detect mechanically, electrically, or optically, and the mechanism of the detection means 36 is not limited.

With the above configuration, the state of displacement of the endless belt 20 on one side can be measured numerically, and the displacement of the driven roller 14 can be easily adjusted.

[0046]

As is clear from the above-described embodiments, according to the present invention, the center of the support frame that rotatably supports the driven roller is supported by support means with a spring interposed, and the driven roller is Since it is held in a seesaw state, the driven roller smoothly follows the displacement of the endless belt.
It is possible to easily correct the meandering of an endless belt, and to provide an inexpensive belt conveying device with less damage to the endless belt. Further, it is possible to provide a belt conveying device in which the skewed state of the endless belt can be measured numerically and the displacement of the driven roller can be easily adjusted.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional top view of a belt conveying device according to a first embodiment of the present invention.

[Fig. 2] A perspective view of the belt conveying device in the first embodiment.

[
FIG. 3 is a sectional view showing the support means of the belt conveying device in the first embodiment.

FIG. 4 is a schematic diagram showing the relationship between the belt conveying device and the photoreceptor in the first embodiment.

FIG. 5 is a schematic diagram of an image forming apparatus incorporating a belt conveying device in the first embodiment.

[Fig. 6] A perspective view of a roller to explain the meandering generation mechanism of the belt.

[Fig. 7] A perspective view of the belt showing the belt advancement vector to explain the meandering generation mechanism of the belt.

FIG. 8 is a top view showing the driven roller portion for explaining belt meandering correction in the first embodiment.

FIG. 9 is a partially sectional top view of a belt conveying device according to a second embodiment of the present invention.

FIG. 10 is a partially sectional top view of a driven roller portion explaining the positional relationship of support means in the second embodiment.

[Figure 11
]A sectional view showing the support means in the third embodiment.

[Figure 12]
A partially sectional top view of the belt conveying device in the fourth embodiment

[Fig. 13] Front view of a conventional belt conveying device

[Explanation of symbols]

12 Transport unit main body 13 Drive roller 14 Followed roller 15 Support frame 16 Support frame side support part 19 Bearing 20 Endless belt 21 Spring 22, 30, 30' Support means 26 Flange 28 Compression spring 35 Alignment bearing 36 Detection means

Claims (4)

[Claims] Claims: 1. A transport unit main body rotatably supporting a drive roller at one end and a driven roller provided at the other end; a support frame rotatably supporting the driven roller; and a central portion of the support frame. and an endless belt wound around the drive roller and the driven roller, and a force is applied to the support means in a direction in which the endless belt is stretched. The belt conveying device has a structure in which the driven roller is swingably supported with respect to the conveying unit main body using the axial center of the driven roller as a fulcrum via a biasing spring. 2. The belt conveying device according to claim 1, further comprising a plurality of supporting means for swingably supporting the driven roller, and the plurality of supporting means are provided near the center of a support frame for supporting the driven roller. 3. The belt conveying device according to claim 1, wherein at least one of the supporting portion of the supporting means on the side of the conveying unit main body and the connecting portion of the supporting frame is movable. 4. A flange provided at both ends of the driven roller, a compression spring provided between the flange and the side edge of the endless belt wound around the driven roller, and a detection means for detecting the degree of compression of the compression spring. 3. The belt conveying device according to claim 1, further comprising: a configuration for detecting deviation of the endless belt.