Patent Description:
Patent Literature <NUM> discloses a yarn re-winder which is configured to re-wind a yarn supplied from a yarn supply package to a bobbin so as to form a wound package. To be more specific, the yarn re-winder includes a bobbin holding member (support arm) which is swingable and supports a bobbin to be rotatable, a friction roller which makes contact with a wound package and rotates the wound package, and a motor which rotationally drives the friction roller. As the friction roller is rotationally driven, the wound package passively rotates and a yarn is wound onto the wound package (winding operation). The support arm swings as the diameter of the wound package increases.

In the above-described yarn re-winder, the wound package may vibrate due to reasons such as deformation of the wound package (i.e., slight deviation from the optimal shape). Such vibration may cause further deformation of the rotating wound package, and this may result in collapse in shape of the wound package. To solve this problem, for example, a vibration suppression mechanism shown in Patent Literature <NUM> may be provided in the above-described yarn re-winder. The vibration suppression mechanism includes a brake piece attached to a support arm, a brake body pressed onto the brake piece, and a spring biasing the brake body. With this arrangement, the vibration of the support arm is suppressed by friction force acting between the brake piece and the brake body, and hence the vibration of the package is suppressed.

In the vibration suppression mechanism of Patent Literature <NUM>, the biasing force of the spring is not actively changed in the winding operation. On this account, when the biasing force of the spring is set large in advance in order to ensure the suppression of vibration, the above-described friction force may become too large. When the friction force is too large, the swing of the support arm in accordance with the increase in diameter of the wound package may not be smoothly performed. Meanwhile, when the biasing force is set small in advance in order to ensure smooth swing of the support arm, the friction force may become too small. When the friction force is too small, the vibration of the wound package may not be sufficiently suppressed. Furthermore, when, for example, the biasing force required for sufficiently suppressing the vibration of the wound package is significantly larger than the biasing force which is sufficient to allow the support arm to smoothly swing, it may be impossible to achieve both the smooth swing of the support arm and the suppression of the vibration of the wound package.

An object of the present invention is to achieve both smooth movement of a support arm and suppression of vibration of a package.

The above problems are resolved by the invention as defined in the appended independent claim. Further embodiments are defined in the dependent claim.

A yarn winder of a first aspect of the invention is defined in claim <NUM>.

According to this aspect, as the vibration suppression member is pressed onto the support arm by the pressing mechanism, friction force acts between the vibration suppression member and the support arm. This friction force suppresses the vibration of the support arm, with the result that the vibration of the package is suppressed. Furthermore, the pressing mechanism is able to change the magnitude of the pressing force during the winding operation. In other words, the friction force is changeable during the winding operation. Therefore, when the support arm is moved in the predetermined direction, the support arm can be smoothly moved in a reliable manner as the friction force is decreased. Meanwhile, when the vibration of the package is suppressed, the suppression of the vibration of the support arm is ensured as the friction force is increased. As such, both the smooth movement of the support arm and the suppression of the vibration of the package are achieved.

According to a second aspect of the invention, the yarn winder of the first aspect is arranged such that the pressing mechanism includes a fluid pressure cylinder which changes the magnitude of the pressing force in accordance with t pressure of supplied fluid.

As the pressing mechanism, for example, a typical ball-screw mechanism or an electric actuator may be used. These mechanisms, however, essentially change the position of an object rather than the magnitude of pressing force. For this reason, it may be difficult to precisely control the magnitude of the pressing force by these mechanisms. Furthermore, the above-described mechanisms are typically unlikely to absorb vibration. That is to say, when, for example, the support arm slightly vibrates and the vibration is propagated to the vibration suppression member, repulsion to the vibration by the pressing mechanism tends to occur. This may cause the pressing force to be unstable. According to the aspect, the magnitude of the pressing force can be changed by changing the pressure of the supplied fluid. Furthermore, because the hydrostatic pressure cylinder typically has a cushioning property, even if the vibration suppression member vibrates, the vibration is absorbed and a change in the pressing force is suppressed. It is therefore possible to suppress the pressing force from becoming unstable.

According to a third aspect of the invention, the yarn winder of the first or second aspect further includes a contact pressure applying roller which applies contact pressure to the package which is rotating, the contact pressure applying roller being movable in accordance with a change in diameter of the package.

In the arrangement in which the package rotates while being in contact with the contact pressure applying roller, the package rotates in such a way that its surface is along the surface of the contact pressure applying roller. On this account, depending on, for example, the hardness (density) of the package, significant vibration may occur even if the package is only slightly deformed from the optimal shape. In such an arrangement, the pressing force is changeable, with the result that smooth movement of the support arm and suppression of vibration of the package are both achieved.

In addition to the above, when the support arm and the contact pressure applying roller are both movable, the movement of the support arm and the movement of the contact pressure applying roller may be unstable, and such instability may cause the package to easily vibrate. According to the aspect, because the magnitude of the pressing force is changeable during the winding operation, even if the movement of the support arm or the movement of the contact pressure applying roller becomes unstable, the vibration of the package is reliably suppressed by increasing the pressing force.

According to a fourth aspect of the invention, the yarn winder of the third aspect further includes a biasing mechanism which is configured to bias the contact pressure applying roller toward the package.

For example, in an arrangement in which contact pressure is applied to a package by biasing a support arm toward a contact pressure applying roller, the gravity acting on the package may influence on the magnitude of the contact pressure in addition to the biasing force, depending on the positional relationship between the package and the contact pressure applying roller. In this case, because it may be necessary to take into account of a change in the weight of the package during the winding operation, the contact pressure may not be easily controllable. According to the aspect, because the contact pressure applying roller is biased toward the package, the magnitude of the contact pressure is maintained to be constant by maintaining the biasing force to be constant, irrespective of the weight of the package. In other words, it is unnecessary to take into account of a change in weight of the package. The contact pressure is therefore easily controllable.

According to a fifth aspect of the invention, the yarn winder of the third or fourth aspect further includes: a tension applying mechanism which is configured to apply tension to the yarn wound onto the package and is capable of changing the magnitude of the tension; and a contact pressure changing mechanism which is capable of changing the magnitude of the contact pressure.

Typically, when the tension of the yarn to be wound is high and the contact pressure is high, the density (hardness) of the package is also high. For this reason, when the magnitude of the tension and the magnitude of the contact pressure are changeable as in the aspect, it is possible to wind the yarn with desired density. In this connection, the package rotates with its surface being along the surface of the contact pressure applying roller. On this account, when, for example, the hardness (density) of the package is increased, significant vibration may occur even when the package is only slightly deformed from the optimal shape. In such an arrangement, the pressing force is changeable during the winding operation, with the result that smooth movement of the support arm and suppression of vibration of the package are both achieved.

According to a sixth aspect of the invention, the yarn winder of any one of the first to fifth aspects is arranged such that a contact surface of the vibration suppression member, where the vibration suppression member makes contact with the support arm, extends along the predetermined direction.

When the contact surface is tilted with respect to the predetermined direction (moving direction of the support arm), the support arm may be pressed in the predetermined direction by the vibration suppression member, and hence the support arm may, for example, unintentionally move in the predetermined direction. According to the aspect, because the contact surface extends along the predetermined direction, it is possible to avoid the pressing of the support arm in the predetermined direction by, for example, pressing the vibration suppression member in the direction perpendicular to the contact surface. Therefore, for example, unintentional movement of the support arm in the predetermined direction is avoided.

According to a seventh aspect of the invention, the yarn winder of any one of the first to sixth aspects is arranged such that the vibration suppression member is rotatable about a rotation fulcrum which is fixed to a predetermined position.

According to the aspect, by utilizing the principle of leverage, the vibration suppression member can be strongly and stably pressed onto the support arm.

According to an eighth aspect of the invention, the yarn winder of any one of the first to seventh aspects is arranged such that the cradle device includes an arm driving unit which is configured to move the support arm in the predetermined direction.

According to the aspect, when the support arm is moved by the arm driving unit, the support arm can be smoothly moved as the pressing force is decreased (i.e., the friction force is decreased). Meanwhile, when the support arm is not moved, it is possible to increase the pressing force (i.e., increase the friction force) without any problems. On this account, it is possible to reliably suppress the vibration of the support arm by increasing the pressing force. As such, by changing the magnitude of the pressing force in accordance with the operation of the arm driving unit, it is possible to effectively achieve both the smooth movement of the support arm and the suppression of the vibration of the package.

The yarn winder of any one of the first to eighth aspects may be arranged such that the support arm includes: an arm main body; and a contact target roller which is supported by the arm main body to be rotatable, the vibration suppression member making contact with the contact target roller.

For example, when a part of the support arm in contact with the vibration suppression member is fixed to the arm main body, the friction force may be too large and the movement of the support arm may not be smoothly done. Then, it is possible to facilitate smooth movement of the support arm by the rotatable contact target roller.

According to a ninth aspect of the invention, the yarn winder of any one of the first to eighth aspects is arranged such that the support arm is swingable about a swing fulcrum fixed to a predetermined position.

For example, in an arrangement in which the support arm moves in the predetermined direction in a parallel manner, a space or the like for allowing the support arm to perform the parallel movement is required, and this may cause the upsizing of the device. According to the aspect, the traveling range of the support arm is short at around the swing fulcrum, as compared to the arrangement in which the support arm moves in a parallel manner. It is therefore possible to avoid the increase in size of the device.

The yarn winder further includes a control unit, during the winding operation, the control unit changing the magnitude of the pressing force between first pressing force and second pressing force which is smaller than the first pressing force.

In this case, the friction force is maintained to be large by pressing the vibration suppression member onto the support arm by the relatively large first pressing force, with the result that the vibration of the package is suppressed. Meanwhile, for example, the pressing force is decreased to the second pressing force at predetermined intervals, with the result that the friction force is temporarily decreased and the support arm is allowed to reliably move in the predetermined direction. For these reasons, the vibration of the package is reliably suppressed in the normal state, and the support arm is allowed to smoothly move in a reliable manner when the support arm moves.

The yarn winder further includes an arm driving unit which is configured to move the support arm in the predetermined direction, the control unit setting the magnitude of the pressing force at the first pressing force when the arm driving unit is not driven, and setting the magnitude of the pressing force at the second pressing force when the arm driving unit is driven.

In this case, when the support arm is not moved, it is possible to increase the pressing force without any problems. On this account, it is possible to reliably suppress the vibration of the support arm by the large first pressing force. Meanwhile, when the support arm is moved, the magnitude of the pressing force is decreased to the second pressing force. It is therefore possible to smoothly move the support arm in a reliable manner. As such, both the smooth movement of the support arm and the suppression of the vibration of the package are effectively achieved.

According to a tenth aspect of the invention, the yarn winder of any one of the first to ninth aspects further includes a package diameter detection unit which is configured to detect a change in diameter of the package, the control unit controlling the arm driving unit based on a detection result of the package diameter detection unit.

According to this aspect, it is possible to allow the support arm to suitably move in accordance with a change in diameter of the package.

According to a eleventh aspect of the invention, the yarn winder of any one of the first to tenth aspect further includes a storage unit which stores a pattern regarding a change over time of the pressing force in advance, the control unit reading the patter before the start of the winding operation.

According to this aspect, with the simple control of causing the control unit to read the pattern before the start of the winding operation, it is possible achieve both the smooth movement of the support arm and the suppression of the vibration of the package.

According to a twelfth aspect of the invention, the yarn winder of any one of the first to eleventh aspects further includes: a vibration detection unit which is configured to detect vibration of the package; when the magnitude of the vibration of the package detected by the vibration detection unit is larger than a predetermined threshold, the control unit increasing the pressing force as compared to a case where the magnitude of the vibration is smaller than the threshold.

According to this aspect, because the pressing force is relatively small (i.e., the friction force is relatively small) when the magnitude of the vibration of the package is equal to or lower than a predetermined level, smooth movement of the support arm is facilitated. Meanwhile, because the pressing force is relatively large (i.e., the friction force is relatively large) when the magnitude of the vibration of the package is equal to or higher than the predetermined level, suppression of the vibration of the package is facilitated.

The following will describe an embodiment of the present invention with reference to <FIG>. An up-down direction and a front-rear direction shown in <FIG> will be used as an up-down direction and a front-rear direction of a re-winder <NUM>. A direction orthogonal to both the up-down direction and the front-rear direction (i.e., a direction perpendicular to the plane of <FIG>) is set as an axial direction of a bobbin B. A direction in which a yarn Y runs will be referred to as a yarn running direction.

To begin with, the structure of a re-winder <NUM> (yarn winder of the present invention) of the present embodiment will be described with reference to <FIG> is a schematic side view of the re-winder <NUM>. As shown in <FIG>, the re-winder <NUM> includes members such as a yarn supplying unit <NUM>, a winding unit <NUM>, a controller <NUM> (control unit of the present invention). The re-winder <NUM> is configured to re-wind a yarn Y wound on a yarn supply package Ps supported by the yarn supplying unit <NUM> back to a bobbin B by the winding unit <NUM>, so as to form a wound package Pw (package of the present invention). To be more specific, the re-winder <NUM> is used for, for example, re-winding a yarn Y wound on a yarn supply package Ps in a more beautiful manner, and for forming a wound package Pw with desired density. (Details will be given later.

The yarn supplying unit <NUM> is, for example, attached to a front surface of a lower portion of a base <NUM> which vertically extends. The yarn supplying unit <NUM> is arranged to be able to support the yarn supply package Ps on which the yarn Y is wound. The yarn supplying unit <NUM> is therefore able to supply the yarn Y.

The winding unit <NUM> is configured to form the wound package Pw by winding a yarn Y onto a bobbin B. The winding unit <NUM> is provided at an upper portion of the base <NUM>. The winding unit <NUM> includes members such as a cradle device <NUM> and a contact roller <NUM> (contact pressure applying roller of the present invention).

The cradle device <NUM> supports the bobbin B to be rotatable. The cradle device <NUM> includes a cradle arm <NUM> (support arm of the present invention) which is supported by the base <NUM> to be swingable and supports the bobbin B to be rotatable. At a leading end portion of the cradle arm <NUM>, a bobbin holder (not illustrated) is attached to be rotatable and to hold the bobbin B. The bobbin holder is rotationally driven by a winding motor <NUM>. The winding motor <NUM> is, for example, a typical AC motor in which the rotation number is variable. The winding motor <NUM> is therefore able to change the rotation speed of the bobbin B. The winding motor <NUM> is electrically connected to the controller <NUM> (see <FIG>).

The contact roller <NUM> makes contact with the surface of the wound package Pw to adjust the shape of the wound package Pw by applying a contact pressure to the surface. The contact roller <NUM> is supported by a swinging boom <NUM> to be rotatable with the axial direction of the bobbin B functioning as the rotational axis. The swinging boom <NUM> is attached to the base <NUM> to be swingable with the axial direction of the bobbin B functioning as the swing axis. The contact roller <NUM> makes contact with the wound package Pw and is rotated by the rotation of the wound package Pw.

A traverse guide <NUM> is provided in the vicinity of the contact roller <NUM> (i.e., immediately upstream of the wound package Pw in the yarn running direction). The traverse guide <NUM> is reciprocated in the axial direction of the bobbin B by an unillustrated driving device, so as to traverse the yarn Y.

Between the yarn supplying unit <NUM> and the winding unit <NUM>, a guide roller <NUM> and a tension sensor <NUM> are provided so that the guide roller <NUM> is upstream of the tension sensor <NUM> in the yarn running direction. The guide roller <NUM> guides the yarn Y unwound from the yarn supply package Ps to the downstream side in the yarn running direction. The guide roller <NUM> is provided on the front surface of the base <NUM> and above the yarn supplying unit <NUM>. The guide roller <NUM> is rotationally driven by a roller driving motor <NUM>, for example. The roller driving motor <NUM> is, for example, a typical AC motor in which the rotation number is variable. The roller driving motor <NUM> is therefore able to change the rotation speed of the guide roller <NUM>. The roller driving motor <NUM> is electrically connected to the controller <NUM> (see <FIG>).

The yarn Y running between the wound package Pw and the guide roller <NUM> in the yarn running direction receives a predetermined tension as the wound package Pw and the guide roller <NUM> are differentiated in circumferential speed (i.e., the wound package Pw is rotated at a higher speed than the guide roller <NUM>). The tension varies in accordance with the difference in circumferential speed between the wound package Pw rotationally driven by the winding motor <NUM> and the guide roller <NUM> rotationally driven by the roller driving motor <NUM>. (The larger the difference in circumferential speed is, the higher the tension is. ) In this way, the tension applied to the yarn Y is changeable. The winding motor <NUM> and the roller driving motor <NUM> are equivalent to a tension applying mechanism of the present invention.

The tension sensor <NUM> is provided between the wound package Pw and the guide roller <NUM> in the yarn running direction and is configured to detect the tension applied to the yarn Y. The tension sensor <NUM> is electrically connected to the controller <NUM> (see <FIG>) and sends a result of detection of the tension to the controller <NUM>.

The controller <NUM> includes members such as CPU, a ROM, and a RAM (storage unit <NUM>). The storage unit <NUM> stores, for example, parameters such as an amount of the wound yarn Y, a winding speed, and the magnitude of tension applied to the yarn Y. The controller <NUM> controls components by using the CPU and a program stored in the ROM, based on the parameters stored in the RAM (storage unit <NUM>), etc..

The structure of the winding unit <NUM> will be further detailed with reference to <FIG> shows the winding unit <NUM> and its surroundings. As described above, the winding unit <NUM> includes members such as the cradle device <NUM> and the contact roller <NUM>. The cradle arm <NUM> of the cradle device <NUM> supports the bobbin B from the both sides in the axial direction to be rotatable, for example. Alternatively, the cradle arm <NUM> may support the bobbin B from one side in the axial direction. The cradle arm <NUM> includes an arm main body <NUM> and a contact target roller <NUM>.

The arm main body <NUM> is a member extending in a direction orthogonal to the axial direction of the bobbin B. The arm main body <NUM> is supported to be swingable about a swing fulcrum <NUM> which is attached to a predetermined position of the base <NUM> (i.e., positionally fixed relative to the base <NUM>). The direction of the swing axis of the arm main body <NUM> is, for example, substantially parallel to the axial direction of the bobbin B. The arm main body <NUM> is swung in a predetermined direction orthogonal to the axial direction of the bobbin B (i.e., in a moving direction shown in <FIG>) by an arm driving motor <NUM> (arm driving unit of the present invention) via an endless belt <NUM>, for example. In other words, when the arm main body <NUM> is viewed in the axial direction, if the angle between the vertical line and the center line of the arm main body <NUM> is an angle θ, the angle θ is changeable by the arm driving motor <NUM>. The arm driving motor <NUM> is electrically connected to the controller <NUM> (see <FIG>). The moving direction of the arm main body <NUM> may not be orthogonal to the axial direction of the bobbin B, as long as the moving direction intersects with the axial direction of the bobbin B.

The contact target roller <NUM> is a roller member which is attached to an intermediate part of the arm main body <NUM> in its longitudinal direction so as to be rotatable. The rotational axis direction of the contact target roller <NUM> is substantially parallel to the axial direction of the bobbin B. The contact target roller <NUM> is in contact with a vibration suppression lever <NUM> (vibration suppression member of the present invention).

The vibration suppression lever <NUM> suppresses the vibration of the wound package Pw by suppressing the vibration of the cradle arm <NUM>. The vibration of the wound package Pw occurs due to, for example, the vibration of the cradle arm <NUM> caused by the operation of the winding motor <NUM> and/or slight deformation of the wound package Pw (as compared to the optimal circular shape). When the wound package Pw vibrates, the deformation of the wound package Pw may be accelerated and the shape of the wound package Pw may be collapsed. For this reason, the vibration suppression lever <NUM> is provided to suppress the vibration of the wound package Pw. The vibration suppression lever <NUM> is a long and arc-shaped member. The vibration suppression lever <NUM> is supported to be rotatable about a rotation fulcrum <NUM> which is attached to a predetermined position of the base <NUM> (i.e. positionally fixed relative to the base <NUM>. The direction of the rotation of the vibration suppression lever <NUM> is, for example, substantially parallel to the axial direction of the bobbin B. When viewed in the axial direction of the bobbin B, a contact surface <NUM> (indicated by a thick line) in contact with the cradle arm <NUM> of the vibration suppression lever <NUM> is a circular arc centered on the rotation fulcrum <NUM>. To put it differently, the contact surface <NUM> extends along a predetermined direction (moving direction of the cradle arm <NUM>).

The vibration suppression lever <NUM> is pressed onto the contact target roller <NUM> by a later-described pressing mechanism <NUM>. Friction force therefore acts between the vibration suppression lever <NUM> and the contact target roller <NUM>. This friction force suppresses the vibration of the cradle arm <NUM>, with the result that the vibration of the wound package Pw is suppressed. The direction in which the vibration suppression lever <NUM> is pressed onto the contact target roller <NUM> (pressing direction) is perpendicular to the contact surface <NUM> (as indicated by an arrow <NUM> in <FIG>). This prevents the cradle arm <NUM> to be pressed in the predetermined direction. Therefore, for example, unintentional movement of the cradle arm <NUM> in the predetermined direction is avoided. Furthermore, on account of the principle of leverage with the rotation fulcrum <NUM> functioning as the fulcrum, the junction between the piston rod <NUM> and the vibration suppression lever <NUM> functioning as the force point, and the part where the vibration suppression lever <NUM> is in contact with the contact target roller <NUM> functioning as the action point, the vibration suppression lever <NUM> is strongly and stably pressed onto the contact target roller <NUM>.

As described above, the contact roller <NUM> is supported by the swinging boom <NUM> to be rotatable. The swinging boom <NUM> is supported by the base <NUM> to be swingable (as indicated by an arrow <NUM> in <FIG>). The contact roller <NUM> is swingable in accordance with a change in diameter of the wound package Pw. To be more specific, in accordance with the increase in diameter (thickening) of the wound package Pw on account of the winding of the yarn Y onto the bobbin B, the contact roller <NUM> swings away from the shaft center of the bobbin B in the radial direction of the wound package Pw. The swinging boom <NUM> is biased toward the wound package Pw (i.e., in the direction in which the contact roller <NUM> is pressed onto the wound package Pw) by a biasing mechanism <NUM>.

The biasing mechanism <NUM> includes, for example, an air cylinder <NUM> and an electro-pneumatic regulator <NUM> (contact pressure changing mechanism of the present invention). The biasing mechanism <NUM> is able to change the contact pressure in accordance with the pressure of compressed air supplied to the air cylinder <NUM>. The air cylinder <NUM> is, for example, a typical push-type cylinder. A piston rod <NUM> of the air cylinder <NUM> is connected to the swinging boom <NUM>. The air cylinder <NUM> is connected, through pipes, to a supply port (not illustrated) connected to a source of compressed air and an exhaust port (not illustrated) through which air is discharged. The electro-pneumatic regulator <NUM> is provided between the supply and discharge ports and the air cylinder <NUM>. For example, the electro-pneumatic regulator <NUM> includes plural electromagnetic valves, a pressure gauge, and a controller and is arranged to be able to adjust the pressure of compressed air supplied to the air cylinder <NUM>. The electro-pneumatic regulator <NUM> is electrically connected to the controller <NUM> (see <FIG>). The compressed air with pressure adjusted by the electro-pneumatic regulator <NUM> is supplied to the air cylinder <NUM> through a supply tube <NUM>. As a result, the swinging boom <NUM> is pressed by the piston rod <NUM> (as indicated by an arrow <NUM> in <FIG>) and the contact roller <NUM> is biased toward the wound package Pw. In this way, the contact pressure is applied to the wound package Pw.

In the vicinity of the contact roller <NUM>, a proximity sensor <NUM> (package diameter detection unit of the present invention) is provided to detect that the contact roller <NUM> is approaching. A non-limiting example of the proximity sensor <NUM> is an electrostatic capacitance contactless sensor. The proximity sensor <NUM> is provided outside the swing range of the contact roller <NUM> (behind the contact roller <NUM> in <FIG>). The proximity sensor <NUM> is electrically connected to the controller <NUM> (see <FIG>). When the distance between the proximity sensor <NUM> and the contact roller <NUM> becomes equal to or shorter than a predetermined distance, the proximity sensor <NUM> detects that the contact roller <NUM> is approaching, and sends a detection signal to the controller <NUM>.

The following will describe a winding operation of winding the yarn Y by the re-winder <NUM> structured as described above, with reference to <FIG> show actions of the cradle arm <NUM> and the contact roller <NUM> during the winding operation.

To begin with, in a state in which the yarn Y connects the yarn supply package Ps with the wound package Pw (see <FIG>), the controller <NUM> (see <FIG>) controls the winding motor <NUM> and the roller driving motor <NUM> to rotate the bobbin B and the guide roller <NUM>. As a result, the yarn Y is wound onto the bobbin B (see <FIG>). The controller <NUM> controls the winding motor <NUM> and the roller driving motor <NUM> so that the circumferential speed of the wound package Pw is higher than the circumferential speed of the guide roller <NUM>. The larger the difference in circumferential speed between the wound package Pw and the guide roller <NUM> is, the higher the tension of the yarn Y is. Furthermore, the controller <NUM> controls the electro-pneumatic regulator <NUM> to keep the pressure of the compressed air supplied to the air cylinder <NUM> to be constant at a predetermined level. As a result, the contact roller <NUM> is biased toward the wound package Pw with predetermined force, and contact pressure is applied from the contact roller <NUM> to the surface of the wound package Pw. Typically, when the tension of the yarn Y is high and the contact pressure is high, the density (hardness) of the wound package Pw is also high.

As the yarn Y is wound onto the bobbin B and the diameter of the wound package Pw increases (i.e., the wound package Pw thickens), the contact roller <NUM> is pressed by the surface of the wound package Pw and moves outward in the radial direction of the wound package Pw (as indicated by an arrow <NUM> in <FIG>). When the distance between the contact roller <NUM> and the contact roller <NUM> becomes equal to or shorter than a predetermined distance, the proximity sensor <NUM> detects that the contact roller <NUM> is approaching, and sends a detection signal to the controller <NUM>. To put it differently, the proximity sensor <NUM> detects a change in diameter of the wound package Pw. When receiving the detection signal from the proximity sensor <NUM>, the controller <NUM> controls the arm driving motor <NUM> to swing the cradle arm <NUM> by a predetermined angle. As a result, the shaft center of the bobbin B moves away from the shaft center of the contact roller <NUM> in the radial direction of the wound package Pw (as indicated by an arrow <NUM> in <FIG>). In accordance with the movement of the wound package Pw, the swinging boom <NUM> swings and the contact roller <NUM> moves away from the proximity sensor <NUM> (as indicated by an arrow <NUM> in <FIG>). As the wound package Pw further thickens, the contact roller <NUM> approaches the proximity sensor <NUM> again. In this way, the contact roller <NUM> reciprocally swings. As the operations above are repeated, the angle θ (see <FIG>) increases in accordance with the thickening of the wound package Pw.

During the winding operation, as the vibration suppression lever <NUM> is pressed onto the contact target roller <NUM> by the pressing mechanism <NUM>, friction force acts between the vibration suppression lever <NUM> and the contact target roller <NUM>. This friction force suppresses the vibration of the cradle arm <NUM>, with the result that the vibration of the wound package Pw is suppressed. In this regard, the vibration suppression lever <NUM> is biased by a spring in known arrangements, and the biasing force is not actively changed during the winding operation. On this account, when the biasing force of the spring is set large in advance in order to ensure the suppression of vibration, the friction force may become too large and the above-described swing of the cradle arm <NUM> may not be smoothly performed. Meanwhile, when the biasing force of the spring is set small in advance in order to ensure smooth swing of the cradle arm <NUM>, the friction force may become too small and the vibration of the wound package Pw may not be sufficiently suppressed. In particular, because the vibration is highly likely to occur when the density (hardness) of the wound package Pw is arranged to be high, the pressing force of the pressing mechanism <NUM> is required to be large. In this case, however, the pressing force required to sufficiently suppress the vibration of the wound package Pw may be significantly larger than pressing force with which the cradle arm <NUM> is smoothly swung. In such a state, smooth swing of the cradle arm <NUM> and suppression of the vibration of the wound package Pw may not be concurrently achieved. Under this circumstance, in the present embodiment, the pressing mechanism <NUM> is arranged as described below, in order to concurrently achieve the smooth swing of the cradle arm <NUM> and the suppression of the vibration of the wound package Pw.

Referring back to <FIG>, the structure of the pressing mechanism <NUM> will be described. The pressing mechanism <NUM> includes, for example, an air cylinder <NUM> (fluid pressure cylinder of the present invention) and an electro-pneumatic regulator <NUM>. The air cylinder <NUM> is, for example, a typical pull-type cylinder. The air cylinder <NUM> is attached to the base <NUM>. A leading end portion of a piston rod <NUM> of the air cylinder <NUM> is connected to an end portion of the vibration suppression lever <NUM>. In the present embodiment, the junction between the vibration suppression lever <NUM> and the piston rod <NUM> is provided to oppose a part where the contact surface <NUM> is formed, over the rotation fulcrum <NUM>. However, the disclosure is not limited to this arrangement. The air cylinder <NUM> is connected, through pipes, to a supply port (not illustrated) connected to a source of compressed air and an exhaust port (not illustrated) through which air is discharged. The air cylinder <NUM> typically has a cushioning property. On this account, even if the vibration suppression lever <NUM> vibrates, the vibration is absorbed and a change in the pressing force is suppressed.

The electro-pneumatic regulator <NUM> is provided between the supply and discharge ports and the air cylinder <NUM>. For example, the electro-pneumatic regulator <NUM> includes plural electromagnetic valves, a pressure gauge, and a controller and is arranged to be able to adjust the pressure of compressed air supplied to the air cylinder <NUM>. The electro-pneumatic regulator <NUM> is electrically connected to the controller <NUM> (see <FIG>). The compressed air with pressure adjusted by the electro-pneumatic regulator <NUM> is supplied to the air cylinder <NUM> through a supply tube <NUM>. As a result, the vibration suppression lever <NUM> is pulled by the piston rod <NUM> (as indicated by an arrow <NUM> in <FIG>) and the contact surface <NUM> is pressed onto the contact target roller <NUM>. The magnitude of the pressing force is changed in accordance with the pressure of compressed air supplied to the air cylinder <NUM>. In other words, the pressing force increases as the pressure of the supplied compressed air increases. As such, the pressing mechanism <NUM> is able to change the magnitude of the pressing force during the winding operation of winding the yarn Y.

The following will describe the control of the pressing force during the winding operation with reference to <FIG> and <FIG> is a graph showing variations over time of an operation of the arm driving motor <NUM> during the winding operation, the pressure of compressed air supplied to the air cylinder <NUM>, and an angle of the cradle arm <NUM>.

In an initial state, the winding operation is performed such that the controller <NUM> rotationally drives the winding motor <NUM> to wind the yarn Y into the bobbin B. The time point t is t0 (see <FIG> and <FIG>). At this stage, the arm driving motor <NUM> is on standby (OFF in <FIG>) and the cradle arm <NUM> is on standby at a predetermined position. In other words, the above-described angle θ is kept constant (θ=θ1 as shown in <FIG> and <FIG>). Furthermore, the pressure of compressed air supplied to the air cylinder <NUM> is at a constant value (P1) (see <FIG>), and the vibration suppression lever <NUM> is pressed onto the contact target roller <NUM> with predetermined first pressing force.

In this state, the yarn Y is wound onto the bobbin B and the wound package Pw increases in diameter as described above, and the contact roller <NUM> swings. As the proximity sensor <NUM> detects that the contact roller <NUM> is approaching, a detection signal is sent to the controller <NUM>. The time point t is t1 at this stage (see <FIG> and <FIG>). Based on the detection result of the proximity sensor <NUM>, the controller <NUM> drives the arm driving motor <NUM> (ON in <FIG>) to swing the cradle arm <NUM>. At the same time, the controller <NUM> controls the electro-pneumatic regulator <NUM> (see <FIG>) to lower the pressure of the compressed air supplied to the air cylinder <NUM> from P1 to P2 (<P1) (see <FIG>). As a result, the magnitude of the pressing force is changed to second pressing force which is smaller than the first pressing force. As such, the magnitude of the pressing force exerted by the pressing mechanism <NUM> is changed during the winding operation of winding the yarn Y. Consequently, the friction force acting between the vibration suppression lever <NUM> and the contact target roller <NUM> is temporarily decreased, with the result that the cradle arm <NUM> smoothly swings.

Thereafter, when the angle θ of the cradle arm <NUM> becomes θ2 (>θ1), the controller <NUM> stops the arm driving motor <NUM> (see <FIG> and <FIG>). At this stage, the time point t is t2. At the same time, the controller <NUM> controls the electro-pneumatic regulator <NUM> to return the pressure of the compressed air supplied to the air cylinder <NUM> from P2 to P1. As a result, the magnitude of the pressing force returns from the second pressing force to the first pressing force, and hence the vibration of the cradle arm <NUM> is suppressed by large friction force again. In this way, the controller <NUM> controls the pressing mechanism <NUM> to change the magnitude of the pressing force between the first pressing force and the second pressing force. As the operations above are repeated, smooth swing of the cradle arm <NUM> and suppression of the vibration of the wound package Pw on account of suppression of the vibration of the cradle arm <NUM> are concurrently achieved during the winding operation of winding the yarn Y.

As described above, as the vibration suppression lever <NUM> is pressed onto the cradle arm <NUM> by the pressing mechanism <NUM>, friction force acts between the vibration suppression lever <NUM> and the cradle arm <NUM>. This friction force suppresses the vibration of the cradle arm <NUM>, with the result that the vibration of the wound package Pw is suppressed. Furthermore, the pressing mechanism <NUM> is able to change the magnitude of the pressing force during the winding operation. In other words, the friction force is changeable during the winding operation. Therefore, when the cradle arm <NUM> is moved in the predetermined direction, the cradle arm <NUM> can be smoothly moved in a reliable manner as the friction force is decreased. Meanwhile, when the vibration of the wound package Pw is suppressed, the suppression of the vibration of the cradle arm <NUM> is ensured as the friction force is increased. As such, both the smooth movement of the cradle arm <NUM> and the suppression of the vibration of the wound package Pw are achieved.

Furthermore, because the pressing mechanism <NUM> includes the air cylinder <NUM>, the magnitude of the pressing force can be changed by changing the supply pressure of the compressed air. Furthermore, because the air cylinder <NUM> typically has a cushioning property, even if the vibration suppression lever <NUM> vibrates, the vibration is absorbed and a change in the pressing force is suppressed. It is therefore possible to suppress the pressing force from becoming unstable.

In the arrangement in which the wound package Pw rotates while being in contact with the contact roller <NUM>, the wound package Pw rotates in such a way that its surface is along the surface of the contact roller <NUM>. On this account, depending on, for example, the hardness (density) of the wound package Pw, significant vibration may occur even when the wound package Pw is only slightly deformed from the optimal shape. In such an arrangement, changeable pressing force and coexistence of smooth movement of the cradle arm <NUM> and suppression of vibration of the wound package Pw are effective.

In addition to the above, when the cradle arm <NUM> and the contact roller <NUM> are both movable, the movement of the cradle arm <NUM> and the movement of the contact roller <NUM> may be unstable, and such instability may cause the wound package Pw to easily vibrate. In the present invention, because the magnitude of the pressing force is changeable during the winding operation, even if the movement of the cradle arm <NUM> or the movement of the contact roller <NUM> becomes unstable, the vibration of the wound package Pw is reliably suppressed by increasing the pressing force.

In addition to the above, because the contact roller <NUM> is biased toward the wound package Pw, the magnitude of the contact pressure is maintained to be constant by maintaining the biasing force to be constant, irrespective of the weight of the wound package Pw. In other words, it is unnecessary to take into account of a change in weight of the wound package Pw. The contact pressure is therefore easily controllable.

In addition to the above, when the magnitude of the tension and the magnitude of the contact pressure are changeable, it is possible to wind the yarn Y with desired density. In this connection, when, for example, the hardness (density) of the wound package Pw is increased, significant vibration may occur even when the wound package Pw is only slightly deformed from the optimal shape. In such an arrangement, changeable pressing force during the winding operation and coexistence of smooth movement of the cradle arm <NUM> and suppression of vibration of the wound package Pw are particularly effective.

In addition to the above, because the contact surface <NUM> of the vibration suppression lever <NUM> extends along the predetermined direction, it is possible to avoid the pressing of the cradle arm <NUM> in the predetermined direction by, for example, pressing the vibration suppression lever <NUM> in the direction perpendicular to the contact surface <NUM>. Therefore, for example, unintentional movement of the cradle arm <NUM> in the predetermined direction is avoided.

In addition to the above, the vibration suppression lever <NUM> is rotatable about the rotation fulcrum <NUM>. Therefore, by utilizing the principle of leverage, the vibration suppression lever <NUM> can be strongly and stably pressed onto the cradle arm <NUM>.

In addition to the above, when the cradle arm <NUM> is moved by the arm driving motor <NUM>, the cradle arm <NUM> can be smoothly moved as the pressing force is decreased (i.e., the friction force is decreased). Meanwhile, when the cradle arm <NUM> is not moved, it is possible to increase the pressing force (i.e., increase the friction force) without any problems. On this account, it is possible to reliably suppress the vibration of the cradle arm <NUM> by increasing the pressing force. As such, by changing the magnitude of the pressing force in accordance with the operation of the arm driving motor <NUM>, it is possible to effectively achieve both the smooth movement of the cradle arm <NUM> and the suppression of the vibration of the wound package Pw.

In addition to the above, it is possible to facilitate smooth movement of the cradle arm <NUM> by the rotatable contact target roller <NUM>.

In addition to the above, the cradle arm <NUM> is swingable about the swing fulcrum <NUM>. The traveling range of the cradle arm <NUM> is therefore short at around the swing fulcrum. It is therefore possible to suppress, for example, the apparatus from being upsized, as compared to an arrangement in which the cradle arm <NUM> is moved in a parallel manner.

In addition to the above, during the winding operation, the controller <NUM> changes the magnitude of the pressing force between the first pressing force and the second pressing force. In other words, when the cradle arm <NUM> does not swing, the vibration suppression lever <NUM> is pressed onto the cradle arm <NUM> with relatively large first pressing force, and hence the friction force is maintained to be large. The vibration of the wound package Pw is therefore suppressed. Meanwhile, when the cradle arm <NUM> swings, the pressing force is temporarily decreased to the second pressing force, with the result that the friction force is temporarily decreased and the cradle arm <NUM> is allowed to reliably swing in the predetermined direction. For these reasons, the vibration of the wound package Pw is reliably suppressed in the normal state, and the cradle arm <NUM> is allowed to smoothly move in a reliable manner when the cradle arm <NUM> swings. As such, both the smooth movement of the cradle arm <NUM> and the suppression of the vibration of the wound package Pw are effectively achieved.

In addition to the above, the controller <NUM> controls the operation of the arm driving motor <NUM> based on a detection result of the proximity sensor <NUM>. It is therefore possible to allow the cradle arm <NUM> to suitably swing in accordance with a change in diameter of the wound package Pw.

The following will describe modifications of the above-described embodiment. The members identical with those in the embodiment above will be denoted by the same reference numerals and the explanations thereof are not repeated.

Control performed by the controller <NUM> in the re-winder 1a arranged as described above will be described with reference to a graph in <FIG>. As shown in <FIG>, when the magnitude of vibration detected by the vibration sensor <NUM> is smaller than a predetermined threshold, the controller <NUM> changes the pressure of compressed air supplied to the air cylinder <NUM> between P1 and P2 in the same manner as in the embodiment above. Meanwhile, when the magnitude of the vibration is larger than the threshold, the controller <NUM> controls the electro-pneumatic regulator <NUM> to arrange the pressure of the compressed air supplied to the air cylinder <NUM> to be P3 which is higher than P1. In other words, when the magnitude of the vibration is larger than the threshold, the above-described pressing force is arranged to be large as compared to a case where the magnitude of the vibration is smaller than the threshold. When the magnitude of the vibration becomes smaller than the threshold again, the controller <NUM> decreases the pressure of the compressed air again. With this arrangement, because the friction force is relatively small when the magnitude of the vibration of the wound package Pw is small, smooth movement of the cradle arm <NUM> is facilitated. Meanwhile, when the magnitude of the vibration of the wound package Pw become large, suppression of the vibration of the wound package Pw is facilitated by relatively large friction force.

Claim 1:
A yarn winder (<NUM>) forming a package (Pw) by winding a yarn (Y) onto a bobbin (B), comprising:
a cradle device (<NUM>) which includes a support arm (<NUM>) supporting the bobbin (B) to be rotatable and is capable of moving the support arm (<NUM>) in a predetermined direction intersecting with an axial direction of the bobbin (B);
a vibration suppression member (<NUM>) which is pressed onto the support arm (<NUM>) so as to suppress vibration of the support arm (<NUM>);
a pressing mechanism (<NUM>) configured to press the vibration suppression member (<NUM>) onto the support arm (<NUM>),
characterized in that:
the pressing mechanism (<NUM>) is capable of changing the magnitude of pressing force during a winding operation of winding the yarn (Y), and
the yarn winder (<NUM>) includes:
a control unit (<NUM>),
during the winding operation, the control unit (<NUM>) changing the magnitude of the pressing force between first pressing force and second pressing force which is smaller than the first pressing force, and
an arm driving unit (<NUM>) which is configured to move the support arm (<NUM>) in the predetermined direction,
the control unit (<NUM>)
setting the magnitude of the pressing force at the first pressing force when the arm driving unit (<NUM>) is not driven, and
setting the magnitude of the pressing force at the second pressing force when the arm driving unit (<NUM>) is driven.