JPH08245019A - Sheet-like member feeding device - Google Patents

Abstract

PURPOSE: To provide a sheet-like member feeding device that can compatible the high speed correction and precision correction of skew feed of a sheet-like member desirably so as to improve the reliability of skew feed correction remarkably. CONSTITUTION: A sheet-like member P is inserted between a pair of first and second rotating rollers 10, 22 and transferred. At the time of detecting the skew feed of the sheet-like member P, the axis of one roller 10 or 22 is inclined at a specified skew angle to the axis of the other roller 22 or 10 to correct the skew feed of the sheet-like member P. In such a sheet-like member feeding device, the maximum value θ of the skew angle is set to ±1 deg. or less, the surface layer part of the first roller 10 is formed of a rubber elastic body 10a, the surface of the second roller 22 is formed of metal, and the hardness of the rubber elastic body 10a is set into a range of 20 deg.-70 deg..

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device.

[0002]

2. Description of the Related Art As a sheet feeding device, there is known a paper feeding device used for feeding a long sheet-shaped member in a printing machine such as an electrophotographic apparatus. BACKGROUND ART Conventionally, a sheet to be conveyed, which is a sheet-shaped member used for image output of an electrophotographic apparatus, has a maximum dimension in the feeding direction of about 1.2 m, and a cut sheet that has been cut into a predetermined length in advance is used. It was In the case of feeding a paper having a length of about this dimension, the phenomenon that the fed paper is skewed, that is, travels diagonally as a whole, and is fed forward while being gradually displaced in the paper width direction, is hardly a problem. Therefore, the function of correcting skew in the paper feeding device is not particularly required.

However, in recent years, when outputting a longitudinal drawing of an automobile, a bridge, a pipeline or the like, it has become impossible to output a satisfactory drawing using conventional standard size paper. For example, there is a demand to continuously output 5 m to 20 m and create one drawing. However, in the above-described conventional paper feeding device of the electrophotographic apparatus, a slight skew which can be ignored until now is enlarged by the long feeding due to a processing error and an assembly error of the paper feeding component. Therefore, there has been a problem that the image is largely separated from the paper. For example, if the paper is fed 1m and skewed by 1mm, 5m is 5m.
At m and 20 m, the end portion of the paper is displaced by 20 mm. Even if a paper margin of 10 mm is provided in advance for printing an image, if the paper is fed for 20 m, the image will protrude by 10 mm outside the paper.

Therefore, various mechanisms have recently been proposed as a paper feeding device having a function of correcting such skew of paper, but these mechanisms are generally complicated and have a large number of parts, and control is difficult. It was a little difficult and the cost was high, which was a problem. However, among these conventional paper feeding devices, the one disclosed in Japanese Patent Laid-Open No. 5-155470 has a simple mechanism and control, and there is little concern that the cost will increase. This skew feeding correction device tilts one of two rotating rolls with respect to the other (hereinafter referred to as "skew") to control the movement of the paper in the width direction.

However, in such a conventional paper feeding apparatus, it is possible to correct skew at the time of paper feeding at a high speed by setting the skew angle of the roll to be relatively large. It is difficult to correct precisely. The present invention, from various test results by the present inventors,
In order to achieve both high-speed correction and precise correction of skew in paper feed, it is necessary to set the skew angle to a small range and to appropriately set the surface friction coefficient of the metal roll and the hardness of the rubber roll. It was made based on.

[0006]

The present invention has been made in view of such conventional technical problems, and has the following structure. According to the configuration of the invention of claim 1, when the sheet-like member P is sandwiched between the pair of rotating first and second rolls 10 and 22 to be transported and the skew of the sheet-like member P is detected, one of the rolls is rolled. A sheet-shaped member feeding device for correcting the skew of the sheet-shaped member P by inclining the central axes of the sheet-shaped members P to the central axes of the other rolls 22 and 10 at a predetermined skew angle. The maximum value θ of the skew angle is set to ± 1 ° or less, the surface layer of the first roll 10 is formed of the rubber elastic body 10a, the surface of the second roll 22 is formed of metal, and the rubber The sheet-shaped member feeding device is characterized in that the hardness of the elastic body 10a is set in a range of 20 ° to 70 °. According to the configuration of the invention of claim 2, the coefficient of friction of the surface of the second roll 22 with respect to the sheet-like member P is smaller than the coefficient of friction of the surface of the first roll 10 and is in the range of more than 0 and 0.5 or less. 2. The sheet-shaped member feeding device according to claim 1, wherein

[0007]

According to the first aspect of the present invention, when the sheet-like member P is sandwiched between the pair of rotating first and second rolls 10 and 22 and is transferred, and the skew of the sheet-like member P is detected, The central axis of one of the rolls 10 and 22 is tilted forward and backward at a predetermined skew angle with respect to the central axis of the other roll 22 and 10 to correct the skew of the sheet member P. At that time, since the maximum value θ of the skew angle for inclining the central axis of the one roll 10, 22 from the neutral position is set to ± 1 ° or less, the skew of the second roll 22 can be accurately and rapidly performed. When the maximum value of the skew angle ± θ is set large, it takes a long time for the second roll 22 to skew to the predetermined angle position, and it is easy to precisely control and give various skew angles of various sizes. This structure makes it difficult.

In addition, the maximum skew angle ± θ is set small as described above, and the hardness of the rubber elastic body 10a of the first roll 10 is set in the range of 20 ° to 70 °. The skew of the member P can be corrected accurately and at high speed. That is, the second surface made of metal
If the surface friction coefficient of the roll 22 is the same, the skew correction angle is substantially inversely proportional to the hardness of the rubber elastic body 10a of the first roll 10. Therefore, in order to perform high-speed and precise skew correction, it is preferable that the hardness of the first roll 10 is low. But,
If the hardness of the rubber elastic body 10a of the first roll 10 is too low, it becomes difficult to perform precision processing for processing the surface of the rubber elastic body 10a into a cylindrical surface, and particularly, a normal straight travel except when skew correction is performed. Since the feeding of the sheet-shaped member P becomes unstable during feeding, the angle is set to 20 ° or more.

That is, in general, a high hardness is required for the rubber elastic body 10a of the first roll 10 in order to improve the processing accuracy, but it is necessary to secure a high-speed and precise skew correction function and improve the processing accuracy. As the harmony point, the hardness of the rubber elastic body 10a of the first roll 10 is set in the above range. As for the processing accuracy of the rubber elastic body 10a of the first roll 10, after all, the processing accuracy cannot be increased to about the second roll 22 made of metal, no matter how hard the hardness is increased due to the restriction of the material. There is no escape from skewing. Therefore, it is important to prioritize the high-speed and precise skew correction function even if the processing accuracy is slightly sacrificed.

According to the second aspect of the invention, the second roll 22
The coefficient of friction of the surface of the sheet-shaped member P with respect to the sheet-shaped member P is set to be smaller than the coefficient of friction of the surface of the first roll 10 and within the range of more than 0 and 0.5 or less. The correction can be performed more precisely and faster. That is, in order to correct the skew of the sheet-shaped member P at high speed, it is preferable that the surface friction coefficient of the second metal roll 22 with respect to the sheet-shaped member P is large. There is a possibility that the sheet becomes stable and that the soft sheet-like member P is damaged due to the skew operation or the feeding operation, and the quality is deteriorated.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 6 show a sheet feeding device according to an embodiment of the present invention. In FIG. 1, reference numeral 10 indicates a first roll which is a drive roll, and the first roll 10
Is formed by fixing a rubber elastic body 10a made of rubber or elastomer to the cylindrical surface portion of a metal (steel) roll member 10b. The first roll 10 has rotatably supported shafts at both ends on fixed side plates 12 and 13 arranged facing each other, does not perform a skew operation, and has a rotation driving device 1
It is driven to rotate by 1.

The second roll 22, which is a driven roll forming a pair with the first roll, is disposed above the first roll 10, and at least the cylindrical surface is made of a high-rigidity material, specifically, metal (steel). There is. Actually, the second roll 22 is entirely made of metal. The second roll 22 has a shaft portion at the other end rotatably and slightly swingably supported by the other side plate 12 (on the left side in FIG. 1) by, for example, a spherical bearing, and performs a skew operation. The skew operation is performed by swinging the shaft portion 22a at one end of the second roll 22 by the skew driving device 3.

The skew driving device 3 includes a worm wheel 16 rotatably supported on a shaft portion at one end of the first roll 10.
And a worm 18 that meshes with the worm wheel 16,
The worm 18 has a motor 20 for rotating the worm 18 in the forward and reverse directions, and the shaft portion 22a at one end of the second roll 22 is rotatable on the oscillating plate 14 fixed to the worm wheel 16 and can be slightly oscillated. It is supported. Specifically, the shaft portion 22a at one end of the second roll 22 extends in the direction connecting the central axes of the two rolls 10 and 22, and the spherical bearing 23 is inserted into the elongated hole 14a formed in the rocking plate 14. It is slidably inserted. Therefore, the shaft portion 22a at one end of the second roll 22
Are positioned so as not to interfere with one side plate 13.
The center O of the worm wheel 16 is aligned with the center axis of the first roll 10 as shown in FIG.

The worm 1 is driven by the motor 20.
When 8 is driven to rotate, the worm wheel 16 and the rocking plate 14 integrally rotate about the central axis of the first roll 10. As a result, the second roll 22 in which the shaft portion 22a at one end is rotatably supported by the swing plate 14 becomes the first roll 1
It moves along the outer peripheral surface of 0. The shaft portion 22a at one end of the second roll 22 is constantly pressed against the outer peripheral surface of the first roll 10 by a predetermined pressing force by an elastic biasing mechanism composed of a spring (not shown). As a result, the contact surface between the cylindrical surface of the rubber elastic body 10a of the first roll 10 and the cylindrical surface of the second roll 22 pressed against the cylindrical surface of the rubber elastic body 10a A band-shaped nip line is formed as a contact surface by elastic deformation.

However, when the first roll 10 is rotationally driven by the rotary drive device 11, the second roll 22, which is pressed against the first roll 10 by a predetermined frictional force, which will be described later, rotates integrally with the first roll 10. The sheet-like member P (usually paper) sent between the first and second sheets 22 and 22 can be sandwiched and transferred in a predetermined discharge direction. Further, skew feed detection sensors 24 and 26 are installed in front of both rolls 10 and 22 in the feed direction and on both sides in the width direction of the sheet-shaped member P, respectively. When the sheet-shaped member P is skewed and the edges thereof approach, the skew detection sensors 24 and 26 detect the approach of the edges and output a detection signal. The detection operation by each skew detection sensor 24, 26 is performed constantly or at predetermined time intervals.

However, when one skew detection sensor 24 detects skew of the sheet-like member P to the left in FIG. 1, the motor 20 predetermined in one direction based on the detection signal. The shaft 22a is rotationally driven for a time, and the shaft 22a at one end of the second roll 22 is moved downward in FIG. 1 (direction B in FIG. 3) by the operation of the skew drive device 3. On the contrary, when the other skew detection sensor 26 detects the skew of the sheet-shaped member P to the right in FIG. 1, the motor 20 moves in the other direction for a predetermined time based on the detection signal. The shaft portion 2 at one end of the second roll 22 is driven to rotate and is operated by the operation of the skew drive device 3.
2a is moved upward in FIG. 1 (direction C in FIG. 3).
As a result, the second roll 22 is skewed with the supporting portion of the other side plate 12 as a fulcrum, and skew correction is performed on the sheet-shaped member P.

The skew angle of the second roll 22 is a range between the lines B and C on both sides of which the supporting portion of the other side plate 12 is a fulcrum, as shown in FIG. Is θ on both sides of the central axis A of the first roll 10. Here, the maximum value of the skew angle ± θ is
± 1 ° or less, preferably ± 0.5 ° or less, preferably ±
Set it to 0.3 ° or less. As a result, the second roll 22
Skew can be performed accurately and at high speed.

The rubber elastic body 1 of the first roll 10 is used in order to exert the skew correction effect well with the maximum skew angle ± θ of the second roll 22 set small.
The hardness of 0a and the surface friction coefficient of the metal second roll 22 are extremely important. The skew correction action by the skew of the second roll 22 is considered as follows. ． The skew correction action by the thrust force generated by the skew operation itself of the second roll 22. ． A skew correction operation by rotating both rolls 10 and 22 with the sheet-shaped member P sandwiched in a state where the second roll 22 is skewed. When the hard second roll 22 is skewed with respect to the rubber elastic body 10a of the first roll 10, a thrust force due to relative slip is generated in the strip-shaped nip line. This thrust force tends to be proportional to the surface friction coefficient and skew angle of the second roll 22 and inversely proportional to the hardness of the rubber elastic body 10a.

Above. The skew feeding correction action due to is caused by the slip between the second roll 22 and the sheet-like member P, but is caused by the forward and backward movements of the skew, respectively.
Offset on the way back and forth. Therefore, the above. The skew correction effect by is not substantially obtained. In addition, since the maximum value of the skew angle ± θ is as small as ± 1 ° or less, the thrust force is slightly generated. The slight difference that can occur on the way back and forth due to is negligible.

Above. The skew correction action by is caused by the rotation of the second roll 22 and the first roll 10 with their central axes intersecting each other. That is, the second roll 22
Skew the second roll 22 in the inclined state.
Contacts the rubber elastic body 10a of the first roll 10 via the sheet-like member P and forms the strip-shaped nip line in an inclined state, so that different circumferential feeds are provided on the contact surfaces of both rolls, The feeding by the inclined second roll 22 is in the direction of correcting the skew of the sheet-shaped member P.

Both rolls 10 and 22 in this skewed state
The strip-shaped nip line is generally wider as the hardness of the rubber elastic body 10a of the first roll 10 is lower, and
The lower the hardness of the rubber elastic body 10a of the roll 10, the second
Since the rubber elastic body 10a of the first roll 10 easily deforms and follows in the feeding direction of the roll 22, the second roll 22
The skew correction effect of the sheet-shaped member P due to the above is increased. If the strip-shaped nip lines of both rolls 10 and 22 have the same size (the hardness of the rubber elastic body 10a of the first roll 10 is the same), the surface friction coefficient of the second roll 22 with respect to the sheet-shaped member P is The larger the value, the greater the skew correction effect of the sheet-shaped member P.

Therefore, the rubber elastic body 1 of the first roll 10
0a has a hardness of 20 ° to 70 °, preferably 30 ° to 60
Set in the range of °. By setting the hardness of the first roll 10 to be low in this way, it is assumed that the surface friction coefficient of the second roll 22 whose surface is made of metal is the same and that the hardness is substantially inversely proportional to the hardness of the rubber elastic body 10a of the first roll 10. The skew correction angle obtained as a result can be increased, and the skew correction can be performed at high speed. However, if the hardness of the rubber elastic body 10a of the first roll 10 is too low, it becomes difficult to perform a precision process for processing the surface of the rubber elastic body 10a into a cylindrical surface, and especially when the skew correction is not performed normally. Since the sheet-shaped member P is unstablely fed at the time of the straight-line feeding, the angle is set to 20 ° or more, preferably 30 °, as a point of harmony between the improvement of the processing accuracy and the high-speed and precise skew correction function.

On the other hand, the surface friction coefficient of the metal second roll 22 with respect to the sheet-like member P is smaller than that of the rubber elastic body 10a of the first roll 10 and exceeds 0.5 to 0.5.
The following range is set, preferably 0.1 to 0.4. As a result, the surface friction coefficient of the second roll 22 is increased to speed up skew correction, and at the same time, the adverse effect of the surface friction coefficient being too large, that is, the skew correction operation becomes unstable, and the skew operation is also reduced. Alternatively, the feeding operation may damage the soft sheet-like member P and suppress the adverse effect that the quality may deteriorate. When the surface friction coefficient is small (less than 0.1), the slip between the second roll 22 and the sheet-like member P is large, and the surface friction coefficient is large (0.1 to 0.4). Compared with this, the skew correction function is slightly reduced.

Next, the operation of the above embodiment will be described. Initially, the central axes of the second roll 22 and the first roll 10 are parallel to each other, and the two rolls 10, 2 are seen in a plan view shown in FIG.
The central axes of 2 overlap and the first roll 10 shown in FIG.
Coincides with the central axis A of the. While the sheet-shaped member P is being fed from the lower side to the upper side in FIG. 1 (from the left side to the right side in FIG. 2), the skew detection sensors 24 and 26 are used to detect the edge of the sheet-shaped member P. While the approach is not detected, the sheet-like member P is sandwiched between the pair of rotating rolls 10 and 22 and conveyed in a straight traveling state.

Therefore, the center line of the strip-shaped nip line should also coincide with the center axis A of the first roll 10, but the nip line is caused by the manufacturing precision and mounting precision of the rolls 10 and 22. Does not accurately form a rectangle with the center axis A as the center line, the sheet-shaped member P
Will be sent out to the left or right. If the sheet-shaped member P begins to shift to the left, for example, in FIG. 1, one of the skew detection sensors 24 detects the edge of the sheet-shaped member P, and a detection signal from the one skew detection sensor 24 is detected. Based on this, the motor 20 is rotationally driven in one direction, and the worm wheel 16 rotates counterclockwise in FIG. 2 via the worm 18.

As a result, the oscillating plate 14 integrated with the worm wheel 16 also oscillates counterclockwise, and the second roll 2
The central axis of 2 is skewed toward the line B in FIG. Accordingly, the strip-shaped nip line is also downward-sloping in FIG. 3, the sheet-shaped member P is fed forward while being corrected to the right, and the skew in the left direction is corrected. When correcting skew as described above, the maximum skew angle ± θ is ± 1
The hardness of the first roll 10 is set to 20 ° or less.
The friction coefficient of the surface of the second roll 22 with respect to the sheet-like member P is set to be in the range of 0 to 70 ° and more than 0 to 0.5 or less. As a result, the high-speed skew correction operation and the precise correction operation can be satisfactorily achieved at the same time.

On the other hand, when the sheet-shaped member P is displaced to the right in FIG. 1, the motor 20 is rotationally driven based on the detection signal from the other skew detection sensor 26, and is shaken in the same manner as above. The moving plate 14 swings clockwise in FIG. 2, and the second roll 22 moves in a direction in which its central axis line approaches the line C in FIG. As a result, the sheet-shaped member P is moved forward while being shifted to the left, and the shift in the right direction is corrected. When the detection operation by the skew detection sensors 24 and 26 is always performed, the motor 20 is rotationally driven according to the presence or absence of the detection signal, and when the detection operation is performed every predetermined time, the motor 20 is rotated. Should be rotationally driven for a predetermined time. If there is no detection signal from the skew detection sensors 24 and 26, the correction operation also stops. In this way,
The skew of the sheet-shaped member P is corrected, and the sheet-shaped member P is fed straight in a predetermined direction.

By using the sheet-shaped member feeding device according to the above-described embodiment, the surface friction coefficient of the rolls 10 and 22, the surface hardness, the skew angle, and the skew correction speed (the sheet-shaped member P is 1
An experiment was carried out to confirm the relationship between the lateral deviation amount (mm) when the sheet was fed m. (I) Equipment conditions Size of the second roll 22 made of steel: outer diameter 20 mm, length 7
00mm Size of the first roll 10: outer diameter 25mm, length 700m
m Sheet-like member P feeding speed: 50 mm / sec

(Experiment 1) Skew Angle and Skew Correction Speed Condition Skew Angle: ± 0.1 °, ± 0.2 °, ± 0.3 °, ± 0.4 ° Surface friction coefficient of the second roll 22 ( μs): 0.12, 0.33 Hardness of the rubber elastic body 10a of the first roll 10: 60 °

The following is known from FIG. 4 showing the experimental results. (1) The skew correction speed is almost proportional to the skew angle. (2) The skew correction direction matches the skew angle direction. (3) The above relationships (1) and (2) hold even if the surface friction coefficient of the second roll 22 changes. (4) The conveyed paper P never moves due to the skew operation of the second roll 22 and the returning operation itself.

(Experiment 2) Surface friction coefficient of steel second roll 22 and skew correction speed Condition Skew angle: + 0.4 ° Surface friction coefficient of second roll 22: 0.12, 0.21, 0. 33 Hardness of the rubber elastic body 10a of the first roll 10: 40 °, 60 °

The following was found from FIG. 5 showing the experimental results. (1) The skew correction speed is almost proportional to the surface friction coefficient of the second roll 22. (2) (1) is established regardless of the hardness of the rubber elastic body 10a of the first roll 10.

(Experiment 3) Hardness of rubber elastic body 10a of first roll 10 and skew correction speed condition Skew angle: + 0.2 °, + 0.4 ° Surface friction coefficient (μs) of second roll 22 made of steel ): 0.33 Hardness of the rubber elastic body 10a of the first roll 10: 40 °, 60 °, 70 °

The following is known from FIG. 6 showing the experimental results. (1) The skew correction speed is substantially inversely proportional to the hardness of the rubber elastic body 10a. (2) The skew correction speed has a relationship substantially proportional to the skew angle if the rubber elastic body 10a has the same hardness.

By the way, the present invention can be applied not only to a printing machine such as an electrophotographic apparatus, but also to a papermaking machine or a film apparatus. In addition, in the above embodiment, the second
With the shaft portion at the other end of the roll 22 as a fulcrum, the shaft portion 22a at one end
It was configured to move the side to perform skew operation,
It suffices that the strip-shaped nip line is skewed, and it is possible to perform the skew operation with the intermediate portion of the second roll 22 in the central axis direction as a fulcrum, and further, the skew operation can be given to the first roll 10. is there.

[0037]

As can be understood from the above description,
According to the present invention, it is possible to satisfactorily achieve both high-speed correction and precise correction of the skew of the sheet-shaped member, and it is possible to significantly improve the reliability of the skew correction.

[Brief description of drawings]

FIG. 1 is a plan view showing a sheet-shaped member feeding device according to an embodiment of the present invention.

FIG. 2 is a side view in which the side plate is also omitted.

FIG. 3 is a diagram similarly showing the maximum value of the skew angle.

FIG. 4 is a view showing the result of Experiment 1 as well.

FIG. 5 is a view showing a result of Experiment 2 as well.

FIG. 6 is a view showing the result of Experiment 3 as well.

[Explanation of symbols]

10: 1st roll, 10a: rubber elastic body, 22: 2nd
Roll, P: sheet-like member, θ: maximum value of skew angle.

Claims (2)

[Claims] 1. A pair of rotating first and second rolls (1)
0, 22), the sheet-like member (P) is sandwiched between the two rolls (2) and (2), and when the skew of the sheet-like member (P) is detected, the central axis of one roll (10, 22) is changed to the other roll (2).
2, 10) is a sheet-like member feeding device that corrects the skew of the sheet-like member (P) by inclining the center axis of the sheet-like member at a predetermined skew angle in a forward and reverse direction. ) Is set to ± 1 ° or less, and the surface layer of the first roll (10) is formed of a rubber elastic body (10a),
A sheet-shaped member feeding device, characterized in that the surface of the second roll (22) is made of metal, and the hardness of the rubber elastic body (10a) is set in the range of 20 ° to 70 °. 2. The coefficient of friction of the surface of the second roll (22) with respect to the sheet-like member (P) is smaller than the coefficient of friction of the surface of the first roll (10) and more than 0 and 0.5 or less. The sheet-shaped member feeding device according to claim 1, wherein the feeding device is set within the range.