JP2735358B2 - Simultaneous biaxial stretching device for sheet material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a simultaneous biaxial stretching provided with an endless link device that simultaneously and continuously stretches a thermoplastic resin sheet in two directions in a longitudinal direction and a width direction. It concerns the device.

[Conventional technology]

A conventional simultaneous biaxial stretching apparatus is as described in Japanese Utility Model Publication No. 45-6785. The outline thereof will be described with reference to Fig. 5. The sheet-like material 1 is a gripper 3 of an endless link device 2.
The film is simultaneously stretched biaxially in the vertical and horizontal directions while continuously moving in the direction of arrow P while holding both ends thereof. The endless link device 2 is driven endlessly by sprockets 7, 8, 9 and its movement is regulated by guide grooves formed by three guide rails 4, 5, 6 arranged on both sides of the sheet-like material. . A is a preheating section, B is a stretching section, C is a heat treatment section, E is a cooling section, F is a film separation section, G is a link return section, J is a link pitch adjustment section, and K is a film gripping section.

[Problems to be solved by the invention]

In the above-mentioned prior art, the link after the extending portion runs in a guide groove composed of three rails with the roller chain fully extended, and is driven by sprockets installed at the entrance and exit of the sheet. Therefore, when the sheet-like material is to be relaxed vertically in the heat treatment process, the roller chain contracts by the amount of the longitudinal relaxation, so that the transmission force by the roller chain becomes 0, and the transmission is performed via the link plate while being regulated by the rail. As a result, an excessive load was applied to the outlet sprocket and the outlet link due to the wedge effect.

SUMMARY OF THE INVENTION An object of the present invention is to provide a simultaneous biaxial stretching apparatus for a sheet-like material capable of reducing a load acting on a link and an outlet-side sprocket, extending the life of the link, and stabilizing the high-speed running.

[Means for solving the problem]

In order to achieve the above object, a link and a driving device are added near the middle of the sprocket and the exit sprocket of the sheet-like material. In the intermediate drive in which a link in the relaxation section is additionally provided from the vicinity of the entrance, the subsequent link is driven by the exit side sprocket, and the load acting on the link is dispersed. Further, by reducing the clearance between the link and the guide groove after the intermediate drive, the amount of backlash of the link disposed between the intermediate drive and the outlet sprocket can be reduced.

[Action]

The intermediate drive pulls the link after the extension section, and
It acts to push the link up to the exit near the relaxation section. By reducing the play (preferably 0.5 mm or less) between the guide groove and the link near the section into which the link is pushed by the intermediate drive, that is, the vicinity of the film relaxation exit, the play of the link is reduced, and the push of the link by the intermediate drive is transmitted. The force is effectively transmitted to the exit side link. As a result, the load acting on the outlet sprocket and, consequently, the load acting on the link are reduced. That is, the load acting on the link can be reduced by dispersing the entire load necessary for driving the link to each drive device.

Also, by reducing the clearance, the backlash of the link is reduced, and the link operates stably during high-speed running.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS.

In FIG. 1, an unstretched flat film 1 is gripped on both side edges in a gripping section K by a gripping device 3 provided in an endless link device 2 and is heated in a preheating section A,
After being simultaneously stretched in the longitudinal and transverse directions in the stretching section B, the film is heat-set at a predetermined temperature in the heat treatment section C, then the film is shrunk in the relaxation section D, cooled in the cooling interval E, and then separated in the film releasing section F. Then, it continuously advances in the direction of the arrow. The endless link device 2 is guided by guide rails 4, 5, and 6, and is driven by sprockets 7, 8, and 9 provided at both ends and a sprocket 10 provided at an intermediate portion.

The endless link device 2 is configured so that the endless link returns to the grasping section K via the return section G and the link pitch adjustment section J.

2 and 3 show details of the endless link device 2. FIG. A pair of isometric outer links 12, 13 and a pair of inner links 14,
15 are connected by link shafts 16a and 16b in a folded shape, and the link shaft 16b is connected to the aforementioned sprocket 7,
Driven by being engaged with 8, 9 and 10, the link shafts 16a and 16b
Rollers 17 and 18 provided at the lower ends of the guide rails move along the grooves formed by the guide rails 4, 6, and 4, 5, respectively. Reference numeral 19 denotes a space link mounted on the upper portions of the bearing rollers 17 and 18, and the roller chain 20 is set at the maximum pitch of the endless link device 2. FIG. 2 shows a state where each part of the endless link device 2 is completely opened, and the film grip pitch at this time is given by Pmax. That is, heat treatment section C
It is a state of. Figure 3 shows a state in which the bearing rollers 17, 18 is constrained to mu _i by the guide rails 4, 5, 6, the film gripping pitch is P _i. That is, the relaxation section D
To the film separation section F.

The input sprocket 8 pushes the endless link device 2 in the gripping section K and the preheating section A, pulls the endless link device 2 in the stretching section B and the heat treatment section C with the chain 11 with the top roller engaged with the sprocket 10, and relaxes the section. Push in the endless link device 2 of D. Cooling section from sprocket 9
E, The endless link device 2 in the film separation section F is pulled.
Further, the endless link device 2 in the return section G is pulled by the sprocket 7 and the link 2 in the link pitch adjustment section J is pulled.
Press. In the intermediate drive devices 10 and 11 (composed of the intermediate sprocket 10 and the chain 11 with the top roller),
The roller 11a of the chain 11 with the top roller engaged with the intermediate sprocket 10 meshes with the link shaft 16b to pull the endless link device 2 in the extending section B, and the endless link device in the relaxing section D after the intermediate drive 10,11. 2 is pushed into the film cooling section E side. By reducing the clearance between the guide groove and the link (preferably 0.5 mm or less), the effect of the transmission force of the outlet side sprocket 9 is increased in the section where the clearance is large, that is, the clearance In the section after the relaxation section D in which is reduced, there is no interference, and the pushing is performed by the intermediate driving devices 10 and 11. Therefore, the load acting on the link can be reduced. Also, by reducing the clearance, the backlash of the link is reduced, and the link operates stably during high-speed running.

Next, a case where the link is pushed in by intermediate driving will be described as a specific example with reference to FIG.

In the figure, the outer diameter dimension D of the bearing roller 18 of the link,
D 'Joint Gap size Q of the guide groove, Q _1', the dimension of Q _2, Q ₂ ', set as follows.

_{Q 1 = Q 2 '= 0.05~0.25mm} Q 2 = Q 2' = 0.20~0.5mm whereas the desired portion pulling the link by outlet sprocket 9, the outer diameter D of the link bearing rollers 18, and D 'guide The dimensions of the clearances Q ₁ , Q ₁ ′, Q ₂ , Q ₂ ′ with the grooves are set as follows.

The outer outside _{Q 1 = Q 2 '= 0.20~0.5mm} Q 2 = Q 1' = 0.05~0.25mm That link in the middle driving section bearing rollers, also an outlet sprocket drive section to reduce the Joint Gap size in the inner Things.

[Effects of the Invention] According to the present invention, the intermediate drive device is provided, and furthermore, by reducing the clearance between the guide groove and the link in the relaxed section, the load acting on each sprocket is dispersed, and the load acting on the link is reduced. Can be greatly reduced, and the link can be stabilized at high speed.

[Brief description of the drawings]

FIG. 1 is a plan view of a simultaneous biaxial stretching apparatus according to one embodiment of the present invention, FIGS. 2 and 3 are detailed plan views of an endless link apparatus of the present invention, respectively, and FIG. FIG. 5 is a plan view of a conventional stretching machine. 1 ... Film, 2 ... Endless linking device, 3 ... Gripping device, 4,5,6 ... Guide rail, 7,8,9,10 ... Sprocket, 11 ... Chain with top roller, 12,13 …… Outer link, 14,15 …… Inner link, 16a, 16b …… Link axis, 1
7,18 …… Bearing roller, 19 …… Roller chain, 20 ……
Space ring

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshiyuki Takamura 794, Higashi-Toyoi, Oaza, Katsumatsu-shi, Yamaguchi Prefecture Inside the Kasado Plant, Hitachi, Ltd. Kasado Office (56) References JP-A-1-247139 (JP, A)

Claims (1)

(57) [Claims] 1. A device for gripping both ends of a film in order to stretch a thermoplastic flat film is arranged symmetrically and endlessly with respect to a film traveling direction, and is provided with a plurality of isometric links connected to each other in a folding manner. The guide groove itself is provided at one end of the movable link device, and the guide groove itself is narrowed while moving in the film advancing direction while gradually increasing the speed along the divergent guide groove. In the axial stretching apparatus, in addition to the means for driving the link device by an exit side on the entrance side of the film and a driving sprocket, an intermediate driving apparatus is provided in the heat treatment section after the stretching process, and the intermediate driving apparatus is connected to the exit side sprocket. The guide groove width of the link up to,
A simultaneous biaxial stretching apparatus for a sheet-like material, wherein a clearance between the guide groove and a link running through the guide groove is reduced.