JP7396015B2 - Work straightening method and work straightening device - Google Patents

Description

The present invention relates to a workpiece straightening method and a workpiece straightening apparatus for correcting the straightness, roundness, etc. of a long metal workpiece such as an aluminum (Al) tube material.

Note that in this specification and claims, the term "aluminum" is used to include aluminum and its alloys.

2. Description of the Related Art Drawn tubes obtained by drawing extruded aluminum tubes, so-called ED tubes, are often used as substrates for photosensitive drums in electrophotographic devices such as copying machines, printers, and facsimiles.

The ED tube used as a substrate for a photosensitive drum is required to have high surface accuracy as well as high dimensional accuracy. In particular, straightness, that is, no waviness or bending in the axial direction, is strictly required.

Under these circumstances, ED pipes, which are long workpieces that have undergone extrusion processing and drawing processing, have traditionally been subjected to straightening processing to improve their straightness and roundness. It is common practice to cut the material into predetermined dimensions and use it as a substrate for a photosensitive drum.

As shown in Patent Documents 1 and 2 below, a workpiece straightening device is used for straightening a long workpiece. As shown in FIG. 4, the work straightening device includes a roll straightening machine 1 that actually straightens the tubular work W, and a work loading machine 2 that throws the tubular work W into the roll straightening machine 1.

The roll straightening machine 1 is arranged along a conveyance line (straightening pass line) X of a tubular workpiece, and includes a large number of pairs of upper and lower drum-shaped straightening rolls 11, 11. Further, among the many sets of straightening rolls 11, 11, a positioning guide is provided on the rear side (upstream side) of the first straightening roll 11, 11 arranged on the most entry side (rear side). A roll 13 is arranged. The guide roll 13 is supported by a lifting cylinder 14 so as to be able to rise and fall between an elevated position corresponding to the transport line X and capable of supporting the tubular workpiece W, and a retreat position where it is retracted downward from the transport line has been done. By connecting the tubular work W between the straightening rolls 11 and 11, the tubular work W is sent forward (downstream) while being given self-axis rotation by the driving force of the straightening rolls 11 and 11, and is straightened during that time. The degree and roundness are now being corrected.

On the other hand, the work feeder 2 includes a plurality of support rolls 21 arranged at intervals along the conveyance line X at the rear (upstream side) of the roll straightening machine 1. Each support roll 21 is configured to be able to carry and support the tubular workpiece W from below, and is supported by the lifting cylinder 22, and has an elevated support position where the tubular workpiece W is supported and a lower support position where it is spaced apart from the tubular workpiece W. It is configured to be able to be individually raised and lowered between the retracted position and the retracted position.

Further, a push member 23 for pushing the work is provided at the rear of the work feeder 2 in correspondence with the transport line X. This pushing member 23 is configured to be able to send the tubular work W forward by a driving means while supporting the rear end portion of the tubular work W.

When straightening a tubular workpiece W using the above-mentioned workpiece straightening device, when the tubular workpiece W is loaded into the roll straightening machine 1 while keeping all the support rolls 21 of the workpiece loading machine 2 at the upward support position, the tubular workpiece W When the tip enters between the first straightening rolls 11 and 11, self-axis rotation is applied to the tubular work W, so the tubular work W swings and the outer circumferential surface of the tubular work W hits the support roll. 21, which may cause harmful scratches on the outer circumferential surface of the tubular workpiece W.

Therefore, as shown in FIG. 5, in order to avoid the above-mentioned surface damage, when the tip of the tubular workpiece W is fed into the introduction positioning guide roll 13 of the roll straightening machine 1, all of the parts on the workpiece feeding machine 20 side are By lowering the support roll 21 to the retracted position and supporting the tubular work W at two points at both front and rear ends, interference between the tubular work W and the support roll 21 is prevented.

Japanese Patent Application Publication No. 2008-161890 Japanese Patent Application Publication No. 2018-118266

By the way, even when the conventional workpiece straightening device is operating normally, when the tip (front end) of the tubular workpiece W enters between the first straightening rolls 11, 11, the tubular workpiece W swings. Vibrations occur, but when the straightening process is repeated, there is a problem in that abnormal vibrations (flapping) with large amplitudes occur. In particular, if such flapping occurs, there is a risk that the contact portion of the tubular work W with the first straightening rolls 11, 11 may be damaged by concave deformation or the like.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a workpiece straightening method and device that can suppress the occurrence of harmful flapping of the workpiece.

In order to achieve the above object, the inventors first investigated the mechanism by which flapping occurs. According to this, when the rear end of the workpiece is pushed while being supported by a pushing member and the front end of the workpiece is thrown into the first straightening roll of the roll straightening machine, the rear end and front end of the workpiece are used as nodes, and the workpiece is Although the workpiece vibrates in its natural vibration mode, it has gradually become clear that there is a close relationship between the natural frequency (Hz) of the workpiece and the rotational speed (r/s) of the workpiece, which rotates on its own axis when placed in the straightening roll. It's becoming clear. Furthermore, the inventor analyzed the investigation results and repeatedly conducted detailed experimental research, and found that resonance occurs when the natural frequency of the workpiece's secondary natural vibration mode matches the workpiece rotation speed. It was discovered that a lot of flapping occurs due to resonance. On the other hand, since the anti-node part of a workpiece that undergoes natural vibration is displaced the most, it was discovered that flapping can be effectively suppressed by suppressing the part that displaces the most, and the present invention was developed based on this finding. I arrived at the eggplant.

That is, the present invention includes the following means.

[1] A pair of straightening rolls placed across a conveyance line is equipped with a plurality of roll straightening machines placed at intervals along the conveyance line, and the long workpieces placed along the conveyance line are then A workpiece straightening method in which the workpiece is fed into the roll straightening machine by pushing the workpiece forward while supporting the end portion with a pushing member,
The position of the work supported by the pushing member is defined as a work rear support position, the position of the work restrained by the first straightening roll of the roll straightening machine is defined as the work straightening entrance position, and the The part from the workpiece correction entrance position to the workpiece rear support position is defined as an unloaded part, and when the flapping suppressing means is brought into contact with the unloaded part from a direction perpendicular to the conveyance line,
When the length of the unloaded part when the natural frequency in the secondary natural vibration mode of the unloaded part matches the rotational speed of the workpiece is "L1",
The position of contact with the workpiece by the flapping suppressing means is set in the range of (0.15×L1) to (0.35×L1) or (0.65×L1) to (with the workpiece correction entrance position as a base point). A workpiece straightening method characterized in that the workpiece straightening method is set within a range of 0.85×L1).

[2] The workpiece straightening method according to item 1, wherein the flapping suppressing means is brought into contact with the workpiece when the length of the unloaded portion is between (0.9×L1) and (1.1×L1). .

[3] The workpiece straightening method according to item 1 or 2, wherein a flapping suppressing roll is used as the flapping suppressing means.

[4] A plurality of support rolls are provided behind the roll straightening machine along the conveyance line,
Each support roll is provided so as to be movable up and down between a raised position where it supports the workpiece and a lowered position where it retreats from the workpiece.
4. The workpiece straightening method according to item 3, wherein any one of the plurality of support rolls also serves as the flapping suppression roll.

[5] The method for straightening a workpiece according to any one of items 1 to 4 above, wherein the workpiece is constituted by an aluminum tube.

[6] The method for straightening a workpiece according to any one of items 1 to 5 above, wherein the workpiece is constituted by a drawn tube.

[7] The workpiece straightening method according to any one of items 1 to 6 above, wherein the workpiece is used as a substrate for a photosensitive drum.

[8] A pair of straightening rolls placed across a conveyance line is equipped with a plurality of roll straightening machines arranged at intervals along the conveyance line, and the long workpieces placed along the conveyance line are then A workpiece straightening device configured to load the workpiece into the roll straightening machine by pushing the workpiece forward while supporting the end portion with a pushing member,
The position of the work supported by the pushing member is defined as a work rear support position, the position of the work restrained by the first straightening roll of the roll straightening machine is defined as the work straightening entrance position, and the A portion from the workpiece correction entrance position to the workpiece rear support position is defined as an unloaded portion, and includes a flapping suppressing means for abutting the unloaded portion from a direction perpendicular to the conveyance line;
When the length of the unloaded part where the natural frequency in the secondary natural vibration mode of the unloaded part and the rotational speed of the workpiece matches is "L1",
The contact position of the flapping suppressing means against the workpiece is in the range of (0.15×L1) to (0.35×L1) or (0.65×L1) to (with the workpiece correction entrance position as a base point). A workpiece straightening device characterized in that the workpiece straightening device is set within a range of 0.85×L1).

According to the workpiece straightening method of invention [1], a part of a vibrating workpiece with a large amount of displacement is identified, and the flapping suppressing means is appropriately brought into contact with the specific part, so that flapping occurs in the workpiece. can be effectively prevented.

According to the workpiece straightening method of invention [2], since the flapping suppressing means is brought into contact with the workpiece W when the length of the unloaded portion is around "L1", the occurrence of flapping is suppressed even more efficiently. can do.

According to the workpiece straightening method of invention [3], since the flapping suppressing roll is brought into contact with the workpiece, the workpiece can be supported in a stable state.

According to the workpiece straightening method of invention [4], since one of the support rolls is also used as a flapping suppressing roll, there is no need to separately provide a flapping suppressing roll, and the component parts can be omitted accordingly. The device can be simplified.

According to the workpiece straightening methods of inventions [5] to [7], the above effects can be obtained more reliably.

According to the workpiece straightening device of invention [8], since an apparatus capable of carrying out the method invention of the above-mentioned [1] is specified, the same effects as described above can be obtained.

FIG. 1A is a side view of a workpiece straightening apparatus for carrying out a workpiece straightening method according to an embodiment of the present invention, before a workpiece is put into a straightening roll. FIG. 1B is a side view of a workpiece straightening device for implementing a workpiece straightening method according to an embodiment of the present invention, showing a state immediately after a workpiece is put into a straightening roll. FIG. 2 is a schematic plan view for explaining the positional relationship between a workpiece and a displacement measuring device in the workpiece straightening device of the embodiment. FIG. 3A is a cross-sectional view for explaining an example of a pushing member applicable to the workpiece straightening device of the embodiment. FIG. 3B is a sectional view for explaining another example of the pushing member applicable to the workpiece straightening device of the embodiment. FIG. 4 is a side view of a conventional workpiece straightening device in a state before the workpiece is put into the straightening roll. FIG. 5 is a side view of a conventional workpiece straightening device in a state immediately after the workpiece is put into the straightening roll.

1A and 1B are side views showing a workpiece straightening device to which a workpiece straightening method according to an embodiment of the present invention is applied. In this specification, in order to facilitate understanding of the invention, the left side of FIGS. 1A and 1B will be referred to as the "front side (downstream side)" and the right side will be referred to as the "rear side (upstream side)". .

First of all, the workpiece W to be straightened in the workpiece straightening apparatus of this embodiment is a tubular workpiece W, such as an ED used as a substrate for a photosensitive drum of an electrophotographic apparatus such as a copying machine, a printer, or a facsimile machine. The target is aluminum pipe materials made of pipes, etc.

As shown in FIGS. 1A and 1B, the workpiece straightening device of this embodiment includes a roll straightening machine 1 provided on the front side (downstream side) and a workpiece inputting machine 2 provided on the rear side (upstream side). It is equipped with

The roll straightening machine 1 includes a housing 10, and within the housing 10, a large number of sets (multiple pairs) of drum-shaped straightening rolls 11, 11 arranged along the conveyance line X and forming upper and lower pairs are provided. There is. In this embodiment, a pair of straightening rolls 11, 11 arranged on the most upstream side (rear side) among the multiple sets of straightening rolls 11, 11 is referred to as first straightening rolls 11a, 11a.

Further, a positioning guide roll 13 is disposed upstream of the first straightening rolls 11a, 11a in the housing 10 so as to be movable up and down.

The workpiece feeder 2 is equipped with a pushing member 23 for pushing the workpieces corresponding to the rear side of the transport line X. This pushing member 23 can push the tubular work W forward over a predetermined distance range by the driving force of a chain drive mechanism or a fluid pressure cylinder mechanism (not shown) while supporting the rear end of the tubular work W. It is configured so that it can be done.

In this embodiment, as will be described later, the position of the workpiece W substantially supported by the pushing member 23 is defined as the workpiece rear support position. This is the position of the node at the rear end when vibrating in the natural vibration mode. Therefore, for example, if the pushing member 23 is a trumpet-shaped pushing member 23 that opens the rear end outer peripheral surface of the workpiece W and supports only the rear end surface in an unsupported state as shown in FIG. 3A, the workpiece W The rear end surface of is set at the workpiece rear support position P2. Furthermore, if the pushing member 23 is a gripping type pushing member 23 that grips and restrains the rear end of the work W as shown in FIG. 3B, the tip of the gripping portion of the pushing member 23 on the work W The position is set to the workpiece rear support position P2.

Further, the workpiece input machine 2 is provided with a plurality of support rolls 21 arranged at intervals along the conveyance line X on the upstream side (rear side) of the roll straightening machine 1. Each support roll 21 is supported by an elevating drive cylinder 22 so as to be movable up and down between an elevated position where it supports the tubular workpiece W on the conveyance line X and a retracted position where it is separated from the tubular workpiece W.

Among the plurality of support rolls 21, the two front support rolls 21a also serve as flapping suppressing rolls constituting flapping suppressing means.

The flapping suppressing roll 21a is arranged at a position unique to this embodiment, as will be described in detail later, and is configured to support and abut a specific portion of the workpiece W to suppress the occurrence of flapping.

Needless to say, the number of support rolls 21 installed is not particularly limited. Further, a support roll 21 that does not also serve as the flapping suppressing roll 21a may be installed between or in front of the flapping suppressing roll 21a.

In the workpiece straightening device of this embodiment, as shown in FIG. 1A, the tubular workpiece W is supported by the support roll 21 in the raised position, and the workpiece W is pushed forward along the conveyance line X by the pushing member 23. Then, when the leading end of the workpiece W is put into the first straightening rolls 11a and 11a and restrained, all the support rolls 21 including the support rolls 21a and 21a that also serve as flapping suppression rolls are in the retracted position. The work W passes between the straightening rolls 11, 11 while being supported at two points, front and back, a restraining position by the straightening rolls 11a, 11a and a supporting position by the pushing member 23. Subsequently, when the work W passes through a predetermined section to be described later, the flapping suppressing rolls 21a, 21a rise and come into contact with the work W, and in this state, the work W is pushed forward. After passing through a predetermined section, the flapping suppressing rolls 21a, 21a descend to the retracted position, and the workpiece W is supported at two points in front and behind the first straightening rolls 11a, 11a and the pushing member 23. , the straightening process is completed by passing between the straightening rolls 11, 11.

In this embodiment, when the leading end of the workpiece W is placed between the first straightening rolls 11a, 11a, the support rolls 21a, 21a, which also serve as flapping suppression rolls, remain elevated and support the workpiece W. Even if the other support rolls 21 descend to the retracted position while the workpiece W passes through a predetermined section, the flapping suppression rolls 21a, 21a descend to the retracted position and separate from the workpiece W. good.

Next, the contact positions of the flapping suppressing rolls 21a, 21a with respect to the workpiece W in this embodiment will be described in detail.

FIG. 2 is a schematic plan view for explaining the positional relationship between the workpiece and the flapping suppressing rolls 21a, 21a in the workpiece straightening device of the embodiment, and the thick wavy line shown in the figure indicates the workpiece in the secondary vibration mode. The waveform when W undergoes natural vibration is exaggerated.

As shown in FIGS. 1A to 2, when the work W is being pushed by the pushing member 23 and being straightened by the straightening rolls 11, when all the support rolls 21 have descended to the retracted position, the first Between the pair of straightening rolls 11a, 11a and the pushing member 23, the front side of the workpiece W is restrained by the first straightening rolls 11a, 11a, and the rear end is supported by the pushing member 23. , it is in a state of vibration mode in which natural vibration occurs with both front and rear ends as nodes.

As shown in FIG. 2, the position of the workpiece W which is restrained by the first straightening rolls 11a, 11a, that is, the position of the front joint, is defined as the workpiece straightening entrance position P1, and the workpiece W is supported by the pushing member 23. The position of the workpiece W, that is, the position of the rear (rear end) joint, is defined as a workpiece rear end support position P2, and furthermore, the part of the workpiece W from the workpiece correction entrance position P1 to the workpiece rear end support position P2 is defined as an unloaded part W1, Let the length of the unloaded portion W1 be "L". This length "L" is a variable value that gradually becomes shorter as the correction process progresses.

On the other hand, when the workpiece W passes through the straightening roll 11, it is rotated around its own axis in the circumferential direction by the driving force of the straightening roll 11.

In this embodiment, the natural frequency fn (Hz) of the unloaded portion W1 of the workpiece W in the secondary natural vibration mode matches the rotational speed Rn (r/s) of the workpiece W when it rotates on its own axis. When the length of the unloaded portion W1 at the time is "L1", the contact position (support position) L2 with respect to the workpiece W by the flapping suppression roll 21a is (0.15 ×L1) to (0.35×L1) or (0.65×L1) to (0.85×L1).

In other words, the following relationship is established: (0.15×L1)≦L2≦(0.35×L1) or (0.65×L1)≦L2≦(0.85×L1).

By setting the contact position L2 by the flapping suppressing roll 21a in the above range in this way, abnormal vibrations such as flapping of the workpiece W can be effectively suppressed.

In other words, the inventor discovered that resonance occurs when the natural frequency fn of the workpiece W in the secondary natural vibration mode matches the workpiece rotational speed Rn, and that resonance causes a lot of harmful flapping. was clarified. In addition, since a workpiece that undergoes natural vibration has a large amount of displacement at its antinode, this part fluctuates greatly when flapping occurs. Therefore, by abutting and supporting the flapping suppressing roll 21a around the abdomen, the occurrence of flapping can be effectively suppressed.

Therefore, in the workpiece W of length L1 (unloaded portion W1) that naturally vibrates in the secondary natural vibration mode, the antinode position is 0.25×L1 from the workpiece correction entrance position P1, and 0. Since the position is set at a position of .75×L1, we found a method of monitoring the surrounding area and derived the above relational expression.

Furthermore, the length L of the unloaded portion W1 gradually becomes shorter as the straightening process progresses, but the length L of the unloaded portion W1 becomes smaller when the natural frequency in the secondary natural vibration mode becomes equal to the rotational speed. Since the length of the unloaded portion W1 becomes "L1" and the displacement becomes large, the occurrence of flapping can be suppressed more effectively by bringing the flapping suppression roll 21a into contact before and after the length of the unloaded portion W1 reaches "L1". becomes possible. Specifically, the length L of the unloaded portion W1 is preferably between (0.9×L1) and (1.1×L1), and more preferably ( It is preferable to bring the flapping suppressing roll 21a into contact between 0.95×L1) and (1.05×L1). In this embodiment, the preferable length range of the unloaded portion W1 to which the flapping suppressing roll 21a comes into contact corresponds to the above-mentioned predetermined section. In addition, in this embodiment, the preferable length range of the unloaded portion W1 to which the flapping suppression roll 21a comes into contact includes an upper limit value and a lower limit value, respectively. In other words, when the length of the unloaded portion W1 that is preferable for contacting the flapping roll 21a is "La", the relationship (0.9×L1)≦La≦(1.1×L1) is established. More preferably, the relationship (0.95×L1)≦La≦(1.05×L1) is established.

In this embodiment, a part of the support roll 21 is also used as the flapping suppression roll 21a, but the present invention is not limited to this, and in the present invention, the flapping suppression roll 21a is provided separately from the support roll 21. You can do it like this. Furthermore, in the embodiment described above, the flapping suppressing roll 21a is used as the flapping suppressing means, but in the present invention, the flapping suppressing means is not limited to the roll, and the flapping suppressing means is not limited to the roll. Any device may be used as long as it can suppress flapping (vibration) by coming into contact with it from a direction perpendicular to the direction. For example, a guide roll may be used as the flapping suppressing means.

Next, a specific method for calculating the contact position of the flapping suppressing roll 21a with respect to the workpiece W will be explained.

First, the rotation speed Rn (r/s) of the tubular workpiece W that rotates on its own axis in the circumferential direction during straightening is determined by actual measurement or the like. For example, the rotational speed of the tubular workpiece W that is rotated in a stable state by the driving force of the straightening roll 11 is measured using a tachometer to determine the rotational speed Rn. Note that if the influence of slippage between the straightening roll 11 and the tubular workpiece W is clearly understood, the rotational speed Rn of the tubular workpiece W can be calculated from the rotational speed of the straightening roll 11 and the installation angle of the straightening roll 11. You can also do it.

Next, the natural frequency fn of the tubular workpiece W in the second natural vibration mode is determined using the following relational expression.

Here, "kn" is a constant corresponding to the eigenvalue, "E" is the modulus of longitudinal elasticity, "I" is the moment of inertia, "A" is the cross-sectional area, and "L" is the length (the length of the unfilled part W1). ), ``ρ'' is the density.

In this relational expression, "kn" is calculated using the second natural vibration mode with one end fixed and one end supported. In other words, it can be considered that the straightening roll 11 side is in a fixed state and the pushing member 23 side is in a supported state.

Therefore, as described above, when the length of the unloaded portion W1 becomes "L1", the natural frequency fn and the rotation speed Rn become equal.

In the work straightening device of this embodiment, as described above, after determining the contact position L2 of the flapping suppression roll 21a, full-scale mass production is started. During mass production, the workpieces W are properly abutted and supported by the flapping suppression roll 21a, thereby effectively suppressing the occurrence of flapping, preventing the generation of defective workpieces, and improving production efficiency. There is.

As described above, in the workpiece straightening device of the present embodiment, a portion of the vibrating workpiece W with a large amount of displacement is specified, and the flapping suppression roll 21a is brought into contact with the specified portion. It is possible to effectively prevent the occurrence of sticking. Therefore, generation of defective workpieces W due to flapping can be reliably prevented, and yield and production efficiency can be improved.

In addition, in the workpiece straightening device of this embodiment, when the flapping suppression roll 21a is brought into contact with the workpiece W while the length of the unloaded portion W1 is around "L1", the occurrence of flapping is suppressed even more efficiently. can do. However, in the present invention, in addition to bringing the flapping suppressing roll 21a into contact with the work W while the length of the unloaded portion W1 is around “L1”, in addition, the length of the unloaded portion W1 is around “L1”. The flapping suppressing roll 21a may be brought into contact with the workpiece W at other times.

A tubular thin-walled aluminum tube as the workpiece W was straightened using a roll straightening device similar to that of the above embodiment. At this time, the circumferential rotation speed Rn (r/s) of the work W in the circumferential direction is measured by actual measurement, and the work W when the natural frequency fn (Hz) in the secondary natural vibration mode matches the above rotation speed Rn. The length L1 (unloaded portion W1) was calculated in the same manner as in the above embodiment.

As shown in Table 1, in level (experiment example) 1, the support roll 21a, which also serves as a flapping suppression roll, is installed at a distance of 0.1 x L1 from the workpiece correction entrance position P1. did. Similarly, for levels 2 to 9, 0.2 x L1, 0.3 x L1, 0.4 x L1, 0.5 x L1, 0.6 x L1, 0 Support rolls 21a, which also serve as flapping suppression rolls, were installed at distances of .7×L1, 0.8×L1, and 0.9×L1, respectively. Note that in the item of measurement position in Table 1, only the ratio of distance to L1 is listed.

Here, levels 2, 3, 7, and 8 correspond to Examples as shown in Table 1, and the flapping suppressing roll 21a falls within the range of "L2", which is a range specific to the present invention, that is, (0.15 ×L1) to (0.35×L1) or (0.65×L1) to (0.85×L1).

On the other hand, levels 1, 4 to 6, and 9 correspond to comparative examples as shown in Table 1, and the flapping suppressing roll 21a is installed at a position that deviates from the range of "L2" described above.

Then, for each level 1 to 9, 200 works W were passed through and straightened. At this time, the flapping suppressing roll 21a is brought into contact with each level 1 to 9 when the length of the unloaded portion W1 of the work W is at least between (0.95×L1) and (1.05×L1). support to suppress the occurrence of flapping.

Then, through operator observation, it is confirmed whether or not harmful flapping has occurred for each level 1 to 9, and for levels where one or more flapping has occurred, it is marked as "×" as it is not possible to reliably suppress flapping. The level where no flapping occurred was rated as "○" as it was considered that flapping could be reliably suppressed. The evaluation results are also shown in Table 1.

As is clear from Table 1, it can be seen that at levels 2, 3, 7, and 8 related to the present invention (examples), the occurrence of flapping can be reliably prevented. On the other hand, in levels 1, 4 to 6, and 9 related to comparative examples that deviate from the gist of the present invention, it can be seen that the occurrence of flapping cannot be reliably prevented.

The workpiece straightening method of the present invention can be suitably used for straightening the straightness, roundness, etc. of a workpiece such as an aluminum tube.

1: Roll straightening machine 11: Straightening roll 11a: First straightening roll 21a: Support roll (flapping suppression roll, flapping suppression means)
23: Push member fn: Natural frequency in the secondary natural vibration mode L: Length of the part where the workpiece is not inserted L1: Length of the part where the workpiece is not inserted when the secondary natural frequency and the rotation speed match L2 :Measurement position (detection position)
P1: Workpiece correction entrance position P2: Workpiece rear end support position Rn: Workpiece rotation speed W: Workpiece W1: Workpiece-unloaded area X: Transport line

Claims (8)

A pair of straightening rolls placed across a conveyance line is equipped with a plurality of roll straightening machines arranged at intervals along the conveyance line, and a long workpiece placed along the conveyance line is straightened at its rear end. A workpiece straightening method in which the workpiece is loaded into the roll straightening machine by pushing it forward while being supported by a pushing member,
The position of the work supported by the pushing member is defined as a work rear support position, the position of the work restrained by the first straightening roll of the roll straightening machine is defined as the work straightening entrance position, and the The part from the workpiece correction entrance position to the workpiece rear support position is defined as an unloaded part, and when the flapping suppressing means is brought into contact with the unloaded part from a direction perpendicular to the conveyance line,
When the length of the unloaded part when the natural frequency in the secondary natural vibration mode of the unloaded part matches the rotational speed of the workpiece is "L1",
The position of contact with the workpiece by the flapping suppressing means is set in the range of (0.15×L1) to (0.35×L1) or (0.65×L1) to (with the workpiece correction entrance position as a base point). Set it within the range of 0.85 x L1) ,
When the workpiece is put into the straightening roll, the flapping suppressing means is retracted and does not come into contact with the workpiece,
A method for straightening a workpiece , characterized in that the flapping suppressing means is brought into contact with the workpiece at a point in time when the second-order natural frequency in the second-order natural vibration mode of the unloaded portion matches the rotational speed of the workpiece . 2. The workpiece straightening method according to claim 1, wherein the flapping suppressing means is brought into contact with the workpiece when the length of the unloaded portion is between (0.9×L1) and (1.1×L1). The workpiece straightening method according to claim 1 or 2, wherein a flapping suppressing roll is used as the flapping suppressing means. A plurality of support rolls are provided behind the roll straightening machine along the conveyance line,
Each support roll is provided so as to be movable up and down between a raised position where it supports the workpiece and a lowered position where it retreats from the workpiece.
The workpiece straightening method according to claim 3, wherein any one of the plurality of support rolls also serves as the flapping suppression roll. The workpiece straightening method according to any one of claims 1 to 4, wherein the workpiece is constituted by an aluminum tube. The workpiece straightening method according to any one of claims 1 to 5, wherein the workpiece is constituted by a drawn pipe. 7. The workpiece straightening method according to claim 1, wherein the workpiece is used as a substrate for a photosensitive drum. A pair of straightening rolls placed across a conveyance line is equipped with a plurality of roll straightening machines arranged at intervals along the conveyance line, and a long workpiece placed along the conveyance line is straightened at its rear end. A workpiece straightening device configured to load the workpiece into the roll straightening machine by pushing it forward while supporting it with a pushing member,
The position of the work supported by the pushing member is defined as a work rear support position, the position of the work restrained by the first straightening roll of the roll straightening machine is defined as the work straightening entrance position, and the A portion from the workpiece correction entrance position to the workpiece rear support position is defined as an unloaded portion, and includes a flapping suppressing means for abutting the unloaded portion from a direction perpendicular to the conveyance line;
When the length of the unloaded part where the natural frequency in the secondary natural vibration mode of the unloaded part and the rotational speed of the workpiece matches is "L1",
The contact position of the flapping suppressing means against the workpiece is in the range of (0.15×L1) to (0.35×L1) or (0.65×L1) to (with the workpiece correction entrance position as a base point). 0.85×L1) ,
When the workpiece is put into the straightening roll, the flapping suppressing means is retracted and does not come into contact with the workpiece, and the second natural frequency in the second natural vibration mode of the unloaded part and the rotational speed of the workpiece. A workpiece straightening device characterized in that the flapping suppressing means is configured to come into contact with the workpiece at a time point when the flapping suppressing means coincides with the workpiece .

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