Longitudinal stretching machine
By setting up an auxiliary mechanism in the longitudinal stretching machine, the problem of film slippage caused by changes in forming conditions between the longitudinal stretching machine and the transverse stretching machine was solved, thus achieving stable longitudinal stretching and continuous production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHIBAURA MASCH CO LTD
- Filing Date
- 2026-01-15
- Publication Date
- 2026-07-21
AI Technical Summary
During the conveying process between the longitudinal stretching machine and the transverse stretching machine, the film's forming conditions become unstable due to changes in ambient temperature and humidity, affecting the stability of the stretching process.
An auxiliary mechanism is set in the longitudinal stretching machine, including multiple rollers and auxiliary components. The auxiliary mechanism is located on the downstream side and conveys the film synchronously with the stretching rollers on the downstream side. The film conveying is stabilized by adjusting the mechanism and clamping unit to prevent slippage.
Even with changes in molding conditions, longitudinal stretching can be performed stably, reducing film slippage and improving stretching stability and production continuity.
Smart Images
Figure CN122425885A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a longitudinal stretching machine. Background Technology
[0002] JP2009-249480A discloses a successive biaxial stretching apparatus for forming porous membranes using a transverse stretching machine. This apparatus performs longitudinal stretching using a longitudinal stretching machine, followed by transverse stretching using a transverse stretching machine. The longitudinal stretching machine stretches the membrane longitudinally using the speed difference between the front and rear rollers, while the transverse stretching machine uses clamps to grasp the two side edges of the membrane and stretches it transversely. In this successive biaxial stretching apparatus, to suppress membrane slippage in the longitudinal stretching machine, the transverse stretching machine applies a tension to the membrane exceeding the tensile force required for longitudinal stretching.
[0003] However, generally speaking, there is a gap of several meters between the longitudinal stretching machine and the transverse stretching machine. During the transfer of the film from the longitudinal stretching machine to the transverse stretching machine, it is cooled and shrinks. Therefore, changes in forming conditions such as ambient temperature and humidity may cause the operation to become unstable, requiring corresponding adjustments to the settings. Summary of the Invention
[0004] The purpose of this invention is to enable stable longitudinal stretching even when molding conditions change.
[0005] According to one aspect of the present invention, a longitudinal stretching machine for stretching a film along a conveying direction includes: a plurality of rollers disposed separately in the conveying direction, which stretch the film by means of a difference in rotational speed while conveying the film; and an auxiliary mechanism disposed downstream of the rollers in the conveying direction, which assists in conveying the film in accordance with the conveying speed of the downstream rollers. Attached Figure Description
[0006] Figure 1 This is a structural diagram showing the state of the longitudinal stretching machine involved in the embodiment of the present invention from the side.
[0007] Figure 2 This is the front view of the auxiliary mechanism installed on the longitudinal stretching machine.
[0008] Figure 3 yes Figure 2 Side view of the middle.
[0009] Figure 4 This is a side view showing one of the sprocket units in the holding mechanism.
[0010] Figure 5 This is a block diagram of the auxiliary mechanism.
[0011] Figure 6This is a side view of the clamping unit that constitutes the gripping mechanism.
[0012] Figure 7 This is a rear view of the clamping unit.
[0013] Figure 8 This is a side view showing the gripper of the clamping unit in the open state.
[0014] Figure 9 This diagram illustrates the contact surface between the claw and the membrane.
[0015] Figure 10 This diagram illustrates an example of deformation of the contact surface between the claw and the membrane. Detailed Implementation
[0016] Hereinafter, the longitudinal stretching machine 1 according to an embodiment of the present invention will be described with reference to the accompanying drawings. Furthermore, in each drawing, the scale of each structure has been appropriately changed for ease of explanation, and the illustrations are not necessarily strictly accurate.
[0017] First, refer to Figure 1 The overall structure of the longitudinal stretching machine 1 is described.
[0018] Figure 1 This is a structural diagram showing the state of the longitudinal stretching machine 1 from the side.
[0019] like Figure 1 As shown, the longitudinal stretching machine 1 stretches the film F along the conveying direction (longitudinal direction). The longitudinal stretching machine 1 is part of a successive biaxial stretching device that sequentially stretches the film F longitudinally and laterally, perpendicularly intersecting the conveying direction. A transverse stretching machine (not shown) is provided downstream of the longitudinal stretching machine 1.
[0020] Membrane F is made of resin and contains oil. In this case, the oil content in membrane F is approximately 70%. Membrane F becomes porous when the oil is removed by stretching. Membrane F is, for example, a battery separator disposed between the electrodes of a secondary battery.
[0021] like Figure 1 As shown, the longitudinal stretching machine 1 includes a frame 2, multiple heating rollers 3, stretching rollers 5 as multiple rollers, multiple cooling rollers 6, multiple guide rollers 8, and an auxiliary mechanism 100.
[0022] The stand 2 supports the heating roller 3, stretching roller 5, cooling roller 6, guide roller 8 and auxiliary mechanism 100 with the help of support components (not shown).
[0023] Heating roller 3 is rotatably supported on stand 2. Heating roller 3 is driven to rotate by a drive motor (not shown). Heating roller 3 heats the material supplied from upstream while conveying it downstream to stretch it. The surface of heating roller 3 is heated by a fluid (in this case, high-temperature oil) flowing inside. Three heating rollers 3 are provided here, but there can be one or more. A clamping roller 4 is provided on at least one of the multiple heating rollers 3.
[0024] The clamping roller 4 is pressed against the heating roller 3 with a predetermined pressure while the film F is clamped between the clamping roller 4 and the heating roller 3. The clamping roller 4 rotates as the film F is conveyed and abutted. The clamping roller 4 clamps the film F between the clamping roller 4 and the heating roller 3 and removes oil from the surface of the film F.
[0025] Multiple stretching rollers 5 (five in this case) are separately arranged in the conveying direction. The stretching rollers 5 are driven to rotate by a drive motor (not shown). The stretching rollers 5 located downstream rotate at a higher speed than those located upstream. While conveying the film F, the stretching rollers 5 stretch the film F by utilizing the speed difference between the upstream and downstream sides.
[0026] In recent years, the demand for high strength and thin film has increased, leading to a trend towards higher stretch ratios. However, in the stretching roller 5, oil contained in the film F may precipitate on the surface and remain between the film and the stretching roller 5, potentially causing the film F to slip. Furthermore, to improve productivity, the molding production line is moving at higher speeds, making it difficult to remove the oil from the surface of the film F using the clamping roller 4.
[0027] Therefore, it may be impossible to obtain sufficient clamping force required to stretch the film F using the stretching roller 5. Therefore, in the longitudinal stretching machine 1 according to this embodiment, an auxiliary mechanism 100 is provided to suppress the slippage of the film F relative to the stretching roller 5.
[0028] Cooling roller 6 is rotatably supported on stand 2. Cooling roller 6 is driven to rotate by a drive motor (not shown). Cooling roller 6 cools the material supplied from upstream stretching roller 5 while conveying it downstream. The surface of cooling roller 6 is cooled by a fluid (in this case, low-temperature oil) flowing inside. There are three cooling rollers 6, but there can be one or more. A clamping roller 7 is provided on at least one of the multiple cooling rollers 6.
[0029] The clamping roller 7, with the film F sandwiched between it and the cooling roller 6, is pressed against the cooling roller 6 with a predetermined pressure. The clamping roller 7 rotates as the film F is conveyed and pressed against it. The clamping roller 7 holds the film F between itself and the cooling roller 6 and removes oil from the surface of the film F.
[0030] Guide rollers 8 are respectively disposed upstream and downstream of the auxiliary mechanism 100. The guide rollers 8 change the travel direction of the conveyed film F. One guide roller 8 changes the travel direction in such a way that it guides the film F supplied from the stretching roller 5 via the cooling roller 6 upward. The other guide roller 8 changes the travel direction in such a way that it guides the film F supplied from the auxiliary mechanism 100 toward the transverse stretching machine (not shown).
[0031] The auxiliary mechanism 100 is located downstream of the cooling roller 6. That is, the auxiliary mechanism 100 is located downstream of the stretching roller 5 in the conveying direction. The auxiliary mechanism 100 conveys the film F at the same conveying speed as the stretching roller 5 located at the downstream end. The auxiliary mechanism 100 assists in the conveying of the film F in accordance with the conveying speed of the downstream stretching roller 5.
[0032] In the longitudinal stretching machine 1, an auxiliary mechanism 100 is provided to assist in the conveying of the film F in accordance with the conveying speed of the downstream stretching roller 5. Therefore, even if the film F slides relative to the stretching roller 5, the auxiliary mechanism 100 assists in the conveying of the film F by stretching it downstream in the conveying direction. Thus, the slippage of the film F relative to the stretching roller 5 can be suppressed, and longitudinal stretching can continue stably even if the forming conditions change. In addition, the slippage of the film F in the longitudinal stretching machine 1 can be suppressed without using the transverse stretching machine located downstream.
[0033] The auxiliary mechanism 100 is configured to longitudinally transport the film F, which is conveyed upward from the stretching roller 5 via the cooling roller 6 and the guide roller 8, downward. That is, the auxiliary mechanism 100 is longitudinally arranged so that the conveying direction of the film F is vertical.
[0034] In this way, the auxiliary mechanism 100 is configured to convey the film F along the longitudinal direction (vertical direction), thus reducing the area occupied by the auxiliary mechanism 100 on the stand 2 compared to the case where the film F is conveyed along the transverse direction. Therefore, it is also easy to add the auxiliary mechanism 100 to a longitudinal stretching machine that does not already have one.
[0035] Next, refer to Figures 2 to 5 The specific structure of the auxiliary mechanism 100 will be explained.
[0036] Figure 2 This is the front view of the auxiliary mechanism 100 installed on the longitudinal stretching machine 1. Figure 3 yes Figure 2 Side view. Figure 4 This is a side view of a sprocket unit 30 in the holding mechanism 20. Figure 5 This is a block diagram of auxiliary mechanism 100.
[0037] like Figure 2As shown, auxiliary mechanisms 100 are respectively disposed at both ends of the membrane F in the width direction. Each auxiliary mechanism 100 conveys the membrane F in the conveying direction in a manner that does not stretch the membrane F in the width direction. The distance between the auxiliary mechanisms 100 is adjusted by the adjustment mechanism 50 (described later) in a manner that follows the width of the membrane F.
[0038] The auxiliary mechanism 100 includes a support frame 10, a pair of gripping mechanisms 20, an adjustment mechanism 50, and a controller 60 (see reference). Figure 5 ).
[0039] The support frame 10 is supported on the platform 2 by means of a support component (not shown). The support frame 10 is formed into a rectangular frame shape. A support plate 11 is provided at the center of the support frame 10 in the width direction.
[0040] The support plate 11 extends along the conveying direction. The support plate 11 connects a support portion 10a extending upstream in the conveying direction along the width direction and a support portion 10b extending downstream in the conveying direction along the width direction. The support plate 11 supports the rotary motor 53a of the ball screw 53, which will be described later.
[0041] The holding mechanism 20 is supported on the support frame 10. A pair of holding mechanisms 20 are provided to clamp the membrane F in the width direction. The holding mechanism 20 can be moved in the width direction of the membrane F by the adjustment mechanism 50. The position of the holding mechanism 20 in the width direction of the membrane F is adjusted accordingly to the width of the supplied membrane F. The holding mechanism 20 has a main body 21, a pair of sprocket units 30, a chain 35, and multiple clamping units 40.
[0042] The main body 21 is formed into a roughly rectangular plate shape. For example... Figure 3 As shown, the main body 21 is mounted on the support frame 10 by means of the sliding mechanism 52 described later. That is, the main body 21 can move relative to the support frame 10 in the width direction of the membrane F.
[0043] like Figure 2 and Figure 3 As shown, the sprocket units 30 are respectively arranged on the upstream and downstream sides of the conveying direction. Figure 4 As shown, the sprocket unit 30 has a pair of sprockets 31, a circular plate component 32, and a drive motor 33 (see reference). Figure 5 ).
[0044] A pair of sprockets 31 are arranged in a manner that overlaps at a predetermined distance in the direction of rotation. Each sprocket 31 drives a chain 35, which will be described later.
[0045] The circular plate component 32 is disposed between a pair of sprockets 31 constituting the sprocket unit 30. That is, the circular plate component 32 is disposed between a pair of chains 35, which will be described later. The circular plate component 32 and the sprockets 31 are arranged concentrically (coaxially). The circular plate component 32 rotates synchronously with the pair of sprockets 31.
[0046] Two circular plate components 32 are provided, overlapping a pair of sprocket units 30 in the direction of rotation axis. The abutment portion 32a of the circular plate component 32 closest to one sprocket 31 is formed in a conical shape to facilitate access to the opening and closing portion 44 of the clamping unit 40, which will be described later. Similarly, the abutment portion 32a of the circular plate component 32 closest to the other sprocket 31 is formed in a conical shape to facilitate access to the opening and closing portion 44 of the clamping unit 40, which will be described later. Alternatively, the circular plate component 32 may be constituted by a single component.
[0047] Drive motor 33 (reference) Figure 5 The drive motor 33 drives the sprocket unit 30 to rotate. The drive motor 33 drives at least one of a pair of sprocket units 30 located in the same auxiliary mechanism 100 to rotate. Here, the drive motor 33 drives the sprocket unit 30 on the downstream (lower) side in the conveying direction to rotate.
[0048] Chains 35 are respectively disposed on the upper and lower surfaces of the membrane F. The chains 35 are wound around the sprockets 31 of each of the pair of sprocket units 30. The chains 35 rotate by the rotation of the sprockets 31 and transport the clamping unit 40.
[0049] like Figure 2 As shown, the clamping unit 40 holds the side end of the membrane F while continuously rotating around a pair of sprocket units 30. In a pair of auxiliary mechanisms 100, each clamping unit 40 rotates in opposite directions. That is, one (in Figure 2 The clamping unit 40 (on the left) rotates clockwise, while the other (in...) Figure 2 The clamping unit 40 (located on the right) rotates counterclockwise. Thus, the clamping unit 40 rotates in the same direction (in the opposite position of the pair of auxiliary mechanisms 100) at their respective positions. Figure 2 (The middle part moves linearly downwards.)
[0050] As described above, each auxiliary mechanism 100 conveys the film F in the conveying direction without stretching it in the width direction. That is, the clamping unit 40 is configured to move parallel to the opposite positions of the pair of auxiliary mechanisms 100.
[0051] Alternatively, the spacing between the clamping units 40 of the opposing pair of auxiliary mechanisms 100 can be adjusted to gradually narrow towards the downstream side of the conveying direction by making the position of one of the sprockets 31 in the sprocket units 30 of the same auxiliary mechanism 100 adjustable. In this case, the holding force of the clamping unit 40 can be increased by stretching the membrane F along the width direction.
[0052] like Figure 2 and Figure 3 As shown, the clamping unit 40 has a pair of claws 43 that open when the circular plate member 32 enters and close when the circular plate member 32 exits to hold the film F. The clamping units 40, respectively provided in a pair of auxiliary mechanisms 100, respectively hold both ends of the film F in the width direction when the circular plate member 32 exits. In the auxiliary mechanism 100, by providing the clamping units 40, the film F can be firmly held to assist in conveying. The clamping unit 40 will be referred to later. Figures 6 to 10 Please provide a detailed explanation.
[0053] like Figure 2 As shown, the adjustment mechanism 50 has an end detection sensor 51 as a sensor, multiple sliding mechanisms 52, and ball screws 53 as multiple drive mechanisms.
[0054] End detection sensors 51 are respectively disposed at both ends of the membrane F supplied to the auxiliary mechanism 100. The end detection sensors 51 detect the position of the membrane F in the width direction at both ends. The end detection sensors 51 send an electrical signal corresponding to the detected position of the membrane F's ends to the controller 60 (see reference). Figure 5 ).
[0055] The sliding mechanism 52 supports the main body 21 of the auxiliary mechanism 100 so that it can move relative to the support frame 10 along the width direction of the membrane F. The sliding mechanisms 52 are respectively provided on the upstream and downstream sides of the main body 21 in the conveying direction. Each sliding mechanism 52 has a guide rail 52a supported on the support frame 10 and a slider 52b mounted on the main body 21 and sliding on the guide rail 52a (see reference). Figure 3 ).
[0056] The ball screw 53 has a rotary motor 53a. The ball screw 53 adjusts the position of the auxiliary mechanism 100 in the width direction in a manner that follows the width of the membrane F detected by the end detection sensor 51. The ball screws 53 are respectively provided on the upstream and downstream sides of the main body 21 in the conveying direction and operate synchronously.
[0057] In this way, by providing the adjustment mechanism 50, the position of the pair of auxiliary mechanisms 100 in the width direction can be adjusted in accordance with the width of the membrane F, so that the position of the clamping unit 40 in the width direction relative to the end of the membrane F can always be kept constant.
[0058] Electrical signals from various sensors, such as the end detection sensor 51, are input to the controller 60. The controller 60 controls the operation of the drive motor 33 and the rotary motor 53a. The controller 60 is composed of a microcomputer equipped with a CPU, RAM, ROM, input / output interfaces, etc. The controller 60 performs various processes by reading and executing programs stored in the ROM by the CPU. The controller 60 can also be composed of multiple microcomputers.
[0059] Next, refer to Figures 6 to 10 The clamping unit 40 will be described.
[0060] Figure 6 This is a side view of the clamping unit 40 that constitutes the gripping mechanism 20. Figure 7 This is a rear view of the clamping unit 40. Figure 8 This is a side view showing the gripper 43 of the clamping unit 40 in the open state. Figure 9 This is a diagram illustrating the contact surface 43a between the claw portion 43 and the membrane F. Figure 10 This figure illustrates a deformation example of the contact surface 43a between the claw portion 43 and the membrane F.
[0061] like Figure 6 and Figure 7 As shown, the clamping unit 40 has a main body 41, a pair of claws 43, a pair of opening and closing parts 44, and a pair of helical springs 45 as force-applying components.
[0062] The main body 41 is formed in a block shape. The main body 41 is provided at both ends in the height direction of the clamping unit 40. The main body 41 has a chain portion 42 that forms part of the chain 35.
[0063] Each chain section 42 is connected to the chain section 42 of the adjacent clamping unit 40 to form a chain 35 (see reference). Figure 7 In this way, since the chain portions 42 of the clamping unit 40 are connected to each other to form a pair of chains 35, the driving force from the sprocket 31 can be transmitted to the clamping unit 40, and the clamping unit 40 can be prevented from tilting.
[0064] A pair of claw portions 43 are arranged opposite each other. When the opening and closing part 44 is open, the claw portions 43 are in the open state. When the opening and closing part 44 is closed, the claw portions 43 are in the closed state. Each claw portion 43 has a contact surface 43a that contacts the membrane F.
[0065] With the claw 43 closed, the contact surfaces 43a are parallel to each other across the membrane F. At this time, the contact surfaces 43a are pressed together by the helical spring 45. Thus, the claw 43 can hold the membrane F by the force of the helical spring 45. Figure 9 As shown, a groove 43b is formed on the contact surface 43a.
[0066] The groove 43b is disposed at an angle relative to the conveying direction on the contact surface 43a. Here, the groove 43b is formed on the entire surface of the contact surface 43a. Alternatively, the groove 43b may be formed only on a portion of the contact surface 43a.
[0067] By forming a groove 43b on the contact surface 43a, sliding of the membrane F relative to the contact surface 43a can be prevented. In addition, since the groove 43b is formed obliquely on the contact surface 43a, even if the membrane F slides, the claw 43 will close and can further grip the membrane F.
[0068] In addition, such as Figure 10 As shown, the groove 43b can also be formed into a diagonal shape that intersects the contact surface 43a with an inclined shape. In this case, it can achieve the same effect as the groove 43b formed at an inclined angle.
[0069] like Figure 6 As shown, a pair of opening and closing portions 44 are arranged opposite each other. Each opening and closing portion 44 is connected to the back surface of the claw portion 43. The opening and closing portions 44 are arranged to protrude toward the back surface of the claw portion 43. The opening and closing portions 44 are formed such that their free ends 44a are separated from each other. In addition, as Figure 7 As shown, the opening / closing portion 44 is formed as a curved surface with rounded corners. This allows the circular plate component 32 to easily enter between the pair of opening / closing portions 44.
[0070] A pair of helical springs 45 are provided so as to apply force to each of the opening and closing parts 44. The helical springs 45 apply force to the opening and closing parts 44 in the direction of closing them together. Alternatively, other force-applying components or elastic components such as leaf springs may be provided instead of helical springs 45.
[0071] like Figure 8 As shown, when the circular plate component 32 enters between the pair of opening and closing parts 44, the force of the circular plate component 32 to open the opening and closing parts 44 will overcome the force of the coil spring 45, and the opening and closing parts 44 will be in the open state. As a result, the claw part 43 connected to the opening and closing parts 44 will also be in the open state.
[0072] With the clamping unit 40 positioned around the circular plate member 32, the circular plate member 32 opens the opening / closing portion 44 and the claw portion 43, thus the clamping unit 40 does not hold the membrane F. On the other hand, when the clamping unit 40 is away from the circular plate member 32 ( Figure 2 As shown in the range C), the opening and closing part 44 and the claw part 43 are in a closed state, so the clamping unit 40 holds the membrane F.
[0073] In this way, the opening and closing of the claw 43 can be switched by the entry and exit of the circular plate component 32, so there is no need to set up a complex mechanism for opening and closing the claw 43 to switch the opening and closing of the claw 43.
[0074] The effects of this embodiment will be explained below.
[0075] The longitudinal stretching machine 1, which stretches the film F along the conveying direction, includes: a plurality of stretching rollers 5, which are separately arranged in the conveying direction, and stretch the film F by means of the rotational speed difference while conveying the film F; and an auxiliary mechanism 100, which is arranged downstream of the stretching rollers 5 in the conveying direction, and assists in conveying the film F in accordance with the conveying speed of the downstream stretching rollers 5.
[0076] In addition, the auxiliary mechanism 100 conveys the film F at the same conveying speed as the stretching roller 5 located at the downstream end.
[0077] Based on these structures, since an auxiliary mechanism 100 is provided to assist in the conveying of the film F in accordance with the conveying speed of the downstream stretching roller 5, even if the film F intends to slide relative to the stretching roller 5, the auxiliary mechanism 100 assists in the conveying of the film F by stretching it downstream in the conveying direction. Therefore, sliding of the film F relative to the stretching roller 5 can be suppressed, and thus, even if the forming conditions change, longitudinal stretching can continue stably. In addition, without using a transverse stretching machine located downstream, sliding of the film F in the longitudinal stretching machine 1 can be suppressed.
[0078] The auxiliary mechanism 100 is configured to longitudinally transport the film F, which is conveyed upward from the stretching roller 5, downward.
[0079] According to this structure, the auxiliary mechanism 100 is configured to convey the film F in the longitudinal (vertical) direction, thus reducing the area occupied by the auxiliary mechanism 100 on the stand 2 compared to the case where the film F is conveyed in the transverse direction. Therefore, it is also easy to add the auxiliary mechanism 100 to a longitudinal stretching machine that does not already have one.
[0080] The auxiliary mechanism 100 has clamping units 40 that hold the two ends of the membrane F in the width direction respectively.
[0081] According to this structure, since the auxiliary mechanism 100 has a clamping unit 40, it can firmly hold the membrane F and assist in its transport.
[0082] The auxiliary mechanism 100 also includes: a pair of chains 35, which are respectively disposed on the upper surface side and the lower surface side of the membrane F and transport the clamping unit 40; and a pair of sprockets 31, which are respectively disposed on the upstream side and the downstream side in the transport direction and drive the chains 35.
[0083] According to this structure, the clamping unit 40 is transported by a sprocket 31 and a chain 35. Therefore, the clamping unit 40 is held on the auxiliary mechanism 100 by the engagement of the sprocket 31 and the chain 35. Therefore, there is no need to provide guide components such as guide rails to prevent the clamping unit 40 from falling off the auxiliary mechanism 100.
[0084] It also includes a circular plate component 32, which is disposed between a pair of chains 35 and rotates together with the sprocket 31. The clamping unit 40 has a pair of claws 43, which open when the circular plate component 32 enters and close when the circular plate component 32 exits to hold the membrane F.
[0085] According to this structure, tilting of the clamping unit 40 can be prevented, and the opening and closing of the claw 43 can be switched by the entry and exit of the circular plate member 32, thus eliminating the need for a complex mechanism for opening and closing the claw 43. Therefore, tilting of the clamping unit 40 can be prevented with a simple structure, and the opening and closing of the claw 43 can be switched.
[0086] The claw portion 43 has a groove portion 43b on the contact surface 43a with the membrane F that is inclined relative to the conveying direction.
[0087] According to this structure, since a groove 43b is formed on the contact surface 43a, sliding of the membrane F relative to the contact surface 43a can be prevented. In addition, since the groove 43b is formed obliquely on the contact surface 43a, even if the membrane F slides, the claw 43 will close and can further bite into the membrane F.
[0088] The auxiliary mechanisms 100 are respectively disposed at both ends of the membrane F in the width direction. The longitudinal stretching machine 1 also has an adjustment mechanism 50 that adjusts the distance between a pair of auxiliary mechanisms 100 in a manner that follows the width of the membrane F.
[0089] In addition, each auxiliary mechanism 100 conveys the membrane F along the conveying direction in a manner that does not stretch the membrane F in the width direction.
[0090] In addition, the adjustment mechanism 50 includes: an end detection sensor 51 that detects both ends of the membrane F; and a ball screw 53 that adjusts the position of the auxiliary mechanism 100 in the width direction in a manner that follows the width of the membrane F detected by the end detection sensor 51.
[0091] Based on these structures, by providing the adjustment mechanism 50, the position of the pair of auxiliary mechanisms 100 in the width direction can be adjusted in accordance with the width of the membrane F. Therefore, the position of the clamping unit 40 in the width direction relative to the end of the membrane F can always be kept constant.
[0092] The embodiments of the present invention have been described above. However, the above embodiments only illustrate a part of the application examples of the present invention and are not intended to limit the technical scope of the present invention to the specific structure of the above embodiments.
Claims
1. A longitudinal stretching machine for stretching a film along a conveying direction, characterized in that it comprises: Multiple rollers, separately arranged in the aforementioned conveying direction, stretch the film while conveying it using a difference in rotational speed; and An auxiliary mechanism is provided downstream of the roller in the conveying direction to assist in the conveying of the film in accordance with the conveying speed of the downstream roller.
2. The longitudinal stretching machine according to claim 1, characterized in that, The aforementioned auxiliary mechanism conveys the film at the same conveying speed as the roller located at the downstream end.
3. The longitudinal stretching machine according to claim 1, characterized in that, The aforementioned auxiliary mechanism is configured to transport the film, which is conveyed upward from the aforementioned roller, downward along the longitudinal direction.
4. The longitudinal stretching machine according to claim 1, characterized in that, The aforementioned auxiliary mechanism has clamping units that respectively hold both ends of the membrane in the width direction.
5. The longitudinal stretching machine according to claim 4, characterized in that, It also has: A pair of chains, respectively disposed on the upper and lower surfaces of the membrane, transport the clamping unit; and A pair of sprockets are respectively located on the upstream and downstream sides of the aforementioned conveying direction and drive the aforementioned chain.
6. The longitudinal stretching machine according to claim 5, characterized in that, It also includes a circular plate component, which is disposed between the pair of chains and rotates together with the sprocket. The clamping unit has a pair of claws that open when the circular plate component enters and close when the circular plate component exits to hold the membrane.
7. The longitudinal stretching machine according to claim 6, characterized in that, The claw portion has a groove on the contact surface with the membrane that is inclined relative to the conveying direction.
8. The longitudinal stretching machine according to any one of claims 1 to 7, characterized in that, The aforementioned auxiliary mechanisms are respectively disposed at both ends of the membrane in the width direction. The aforementioned longitudinal stretching machine also includes an adjustment mechanism that adjusts the distance between a pair of the aforementioned auxiliary mechanisms in a manner that follows the width of the aforementioned film.
9. The longitudinal stretching machine according to claim 8, characterized in that, Each of the aforementioned auxiliary mechanisms conveys the membrane along the aforementioned conveying direction in a manner that does not stretch it along the aforementioned width direction.
10. The longitudinal stretching machine according to claim 8, characterized in that, The aforementioned adjustment mechanism has the following characteristics: A sensor that detects both ends of the aforementioned membrane; and The drive mechanism adjusts the position of the auxiliary mechanism in the width direction in a manner that follows the width of the membrane detected by the sensor.