CN208664500U - Paper cap molding equipment - Google Patents

Abstract

The utility model discloses a kind of paper cap molding equipments, include the first turntable, carrying mould is equipped at intervals on the first turntable etc., it is characterised in that: the carrying mould includes the upper die and lower die of relative movement, and upper mold and lower die, which cooperate, is tensioned paper circle；First turntable periphery is corresponding in turn to equipped with paper circle molding machine, facial tissue molding machine, blowing hot-air device, crimping unit, embossing device and lid arrangement out.The utility model is structurally reasonable, forms fast and stable.

Description

Paper cap molding equipment

Technical field

The utility model relates to a kind of improvement of packing box forming field inventions, more particularly to a kind of rectangular or oval paper The improvement of lid molding equipment is invented.

Background technique

Paper cap includes facial tissue and paper circle, in paper cap forming process, needs to carry out impression to paper circle to form water line, glue spraying And transmitting, flanging molding then is carried out to facial tissue, then the facial tissue after flanging is packed into paper circle, paper circle is then subjected to flanging cladding The firmly flanging of facial tissue, is fixedly connected finally by embossing, the utility model be intended to provide it is a kind of it is structurally reasonable, molding is quick Stable paper cap molding equipment.

Utility model content

Technical problem to be solved in the utility model be overcome the deficiencies of the prior art and provide it is a kind of it is structurally reasonable, at The paper cap molding equipment of type fast and stable.

In order to solve the above-mentioned technical problem, the utility model adopts the following technical scheme that realize: this kind of paper cap at Type equipment includes the first turntable, carrying mould is equipped at intervals on the first turntable etc., it is characterised in that: the carrying mould includes The upper die and lower die of relative movement, upper mold and lower die, which cooperate, is tensioned paper circle；First turntable periphery, which is corresponding in turn to, to be equipped with Paper circle molding machine, facial tissue molding machine, blowing hot-air device, crimping unit, embossing device and lid arrangement out.

The paper circle molding machine includes the second turntable, and die holder is equipped at intervals on the second turntable etc., and die holder includes rotation Turn the internal model of setting and the external mold of lifting setting, external mold is set in internal model periphery；Second turntable periphery, which is corresponding in turn to, to be equipped with Paper circle transport mechanism, water line shaping mechanism, glue-spraying mechanism and upper paper loop mechanism；The upper paper loop mechanism is mutually held in the mouth with the first turntable It connects.

The paper circle transport mechanism includes conveyer belt, and conveyer belt front end is equipped with left and right clamp bar, and left and right clamp bar setting exists Above the internal model of die holder, liftable ejection part is equipped with above left and right clamp bar, the paper circle between left and right clamp bar is by liftout portion On part roof fall to the internal model of die holder.

The water line shaping mechanism includes disc impression knife and the first driving part, the dynamic setting of the impression swivel On tool apron, and tool apron is movably arranged, and the internal model outer peripheral surface of the die holder is equipped with impression slot, and impression knife and impression slot match It closes, the internal model of first driving part and die holder, which is driven, to be cooperated.

The glue-spraying mechanism includes that FE Glue Gun, inductor and the second driving part, FE Glue Gun are connected with inductor signal, FE Glue Gun is arranged in corresponding with the paper circle inner wall in internal model above die holder；The transmission of the internal model of second driving part and die holder Cooperation.

The upper paper loop mechanism includes scraping wings and third driving part, and scraping wings is driven by third driving part by paper Circle pushes on carrying mould；It is equipped with the paper coil for carrying vertical paper circle between the carrying mould and scraping wings, is set above paper coil There is the ramp being mutually connected；Paper circle transfer robots are equipped with above the ramp, the paper circle on die holder is transmitted by paper circle Manipulator is transferred to ramp.

The facial tissue molding machine includes facial tissue stocking mechanism and third turntable, and the third turntable is equipped with molding Slot, forming tank is interior to be equipped with interior step, forms flanging mouth at interior step, is corresponding in turn on the rotation path of the forming tank equipped with face Paper transmission mechanism, molding delivery device and de- material delivery device, the facial tissue transmission mechanism linking facial tissue stocking mechanism and molding Slot carries out facial tissue transmitting, and the facial tissue in forming tank is pushed into flanging mouth by the molding delivery device, and the de- material delivery device will Molding facial tissue releases forming tank.

The blowing hot-air device includes hot air source and slide, and the slide is driven by fourth drive part part and is moved, described Slide is equipped with Ventilated seat, is equipped with ventilation housing in Ventilated seat, and Ventilated seat front end is equipped with cover board, before cover board outer peripheral surface and Ventilated seat End face is the tapered surface to match, and arranged for interval forms outlet air gap between cover board outer peripheral surface and Ventilated seat front end face, described Base rear end of divulging information connects hot air source.

The ventilation housing is T-type cavity, and leading portion cavity internal diameter is greater than back segment cavity internal diameter, is equipped in the leading portion cavity Partition, partition fit with cover board, and partition is equipped with one and irises out stomata, venthole connection corresponding with outlet air gap.

The crimping unit includes to pre-fold station and eventually folding station, pre-folds station and folding station includes removable eventually Hemming die, hemming die is equipped with groove, and the inner wall of groove is inclined outwardly to form flanging guide surface, and bottom portion of groove is equipped with arc folding Side slot, the flanging guide surface are mutually connected with arc flanging groove, and the arc flanging groove for pre-folding station, which has, pre-folds the angle R, eventually The arc flanging groove for rolling over station has the folding angle R eventually, pre-folds the angle R and is greater than the folding angle R eventually.

The utility model has the beneficial effects that improved paper cap molding equipment, realizes the molding of paper circle water line, facial tissue Molding, and paper circle is combined into fixation by glue spraying, flanging, embossing with facial tissue, the equipment integral layout is reasonable, realizes paper cap The molding of fast and stable, and made paper cap stable structure.

Detailed description of the invention

Specific embodiment of the present utility model is described in further detail with reference to the accompanying drawing.

Fig. 1 is the structural schematic diagram of the utility model.

Fig. 2 is the structural schematic diagram of the utility model paper circle molding machine.

Fig. 3 is the structural schematic diagram of paper loop mechanism on the utility model.

Fig. 4 is the structural schematic diagram of the utility model facial tissue molding machine.

Fig. 5 is the molding slot structure schematic diagram of the utility model facial tissue molding machine.

Fig. 6 is the structural schematic diagram of the utility model blowing hot-air device.

Fig. 7 is the structural schematic diagram of the utility model crimping unit.

Specific embodiment

Attached drawing illustrates the structure of the utility model, further illustrates it in relation to details in conjunction with attached drawing below.Referring to attached Fig. 1 and attached drawing 2, the paper cap molding equipment include the first turntable 1, and carrying mould 11 is equipped at intervals on the first turntable 1 etc., described Carrying mould 11 includes the upper mold 111 and lower die 112 of relative movement, and upper mold 111 and lower die 112, which cooperate, is tensioned paper circle；Institute State 1 periphery of the first turntable be corresponding in turn to equipped with paper circle molding machine 2, facial tissue molding machine 3, blowing hot-air device 4, crimping unit 5, Embossing device 6 and out lid arrangement 7；The paper circle molding machine 2 includes the second turntable 21, is equipped at intervals on the second turntable 21 etc. Die holder 211, die holder 211 include the internal model 2111 of rotary setting and the external mold 2112 of lifting setting, and external mold 2112 is set in interior 2111 periphery of mould；Second turntable, 21 periphery is corresponding in turn to equipped with paper circle transport mechanism 22, water line shaping mechanism 23, glue spraying Mechanism 24 and upper paper loop mechanism 25；The upper paper loop mechanism 25 is connected with 1 phase of the first turntable.Working principle is that paper circle passes through paper circle Transport mechanism 22 is sent in the internal model 2111 of the die holder 211 of the second turntable 21, as the second turntable 21 rotates, paper circle outer peripheral surface Water line, glue-spraying mechanism 24 are formed by 23 impression of water line shaping mechanism, glue spraying is carried out to paper circle inner wall, then paper circle is by upper paper Loop mechanism 25 is transferred on the carrying mould 11 of the first turntable 1, and as the first turntable 1 rotates, facial tissue molding machine 3 is by facial tissue flanging It is pushed into paper circle afterwards, blowing hot-air device 4 carries out blowing hot-air softening colloid, crimping unit 5 to paper circle to paper circle inner wall glue spraying position Carry out flanging envelope facial tissue tuck portion, embossing device 6 to paper circle tuck portion and facial tissue tuck portion be embossed bonding, Lid arrangement 7 sends molding paper cap outside out.Wherein embossing device 6 is that this will not be repeated here for the prior art.

Paper circle transport mechanism 22, includes conveyer belt 221, and 221 front end of conveyer belt is equipped with left and right clamp bar 222, left and right folder Item 222 is adhesive tape or hairbrush, and 2111 top of internal model of die holder 211, left and right 222 top of clamp bar is arranged in left and right clamp bar 222 Equipped with liftable ejection part 223, ejection part 223 is liftout cylinder, and the paper circle between left and right clamp bar 222 is by ejection part On 223 roof falls to the internal model 2111 of die holder 211, when work, paper circle is sent to front end by conveyer belt 221 and is hanged by left and right clamp bar 222 Sky clamps, and then liftout cylinder decline is inserted in paper circle, and paper circle lower part is socketed in the internal model of die holder by stretching paper circle top, it Liftout cylinder resets afterwards, and wherein paper snare connects the tensile force in internal model greater than the tensile force being socketed on liftout cylinder, i.e., in paper circle Diameter is greater than internal model outer diameter, and internal model outer diameter is greater than liftout cylinder outer diameter.

Referring to attached drawing 2, water line shaping mechanism 23 includes disc impression knife 231 and the first driving part 232, institute It states impression knife 231 to be rotatably arranged on tool apron 233, and tool apron 233 is movably arranged, specific tool apron 233 is arranged in slide 234 On, slide 234 is removably set in fixing seat 235 by power source drive, and power source is cylinder, the internal model periphery of the die holder Face is equipped with impression slot 236, and impression knife 231 is matched with impression slot 236, and first driving part 232 is interior with die holder 211 The transmission cooperation of mould 2111, the first driving part 232 are transmission rubber tire, and corresponding 2111 lower end of internal model is equipped with driven rubber tire 237, interior Mould 2111 is threaded through on the second turntable 21, and the transmission rubber tire is matched with driven rubber tire 237, transmission rubber tire and driven rubber tire 237, which contact with each other, realizes transmission.

Water line shaping mechanism work when, when die holder 211 runs to water line shaping mechanism with the second turntable 21, internal model by The transmission rotation of first driving part 232, then slide 234 is mobile close to internal model, so that impression knife 231 is attached to the impression slot of internal model In 236, and impression knife 231 rotates on tool apron 233 under the action of impression slot 236, impression knife 231 and impression slot 236 It cooperates and one circle water line of impression formation is carried out to paper circle.

Referring to attached drawing 2, glue-spraying mechanism 24 includes FE Glue Gun 241, inductor 242 and the second driving part 243, glue spraying Rifle 241 is connected with 242 signal of inductor, and inductor 242 is infrared inductor 242, and FE Glue Gun 241 is arranged by riding It is corresponding with the paper circle inner wall in internal model 2111 above die holder 211, after inductor 242 senses the paper circle in internal model 2111, It controls FE Glue Gun 241 and glue spraying is carried out to paper circle inner wall；The internal model 2111 of second driving part 243 and die holder, which is driven, to be cooperated, Second driving part 243 is transmission rubber tire, and corresponding 2111 lower end of internal model is equipped with driven rubber tire, is driven rubber tire and driven rubber tire phase Mutually transmission is realized in contact.

Referring to attached drawing 3, upper paper loop mechanism 25 includes scraping wings 251 and third driving part, and scraping wings 251 is by third Driving part transmission pushes to paper circle on carrying mould 11；It is equipped between the carrying mould 11 and scraping wings 251 and carries vertical paper The paper coil 252 of circle is equipped with the ramp 253 being mutually connected above paper coil 252；Paper is equipped with above the ramp 253 Transfer robots 254 are enclosed, the paper circle on die holder 211 is transferred to ramp 253 by paper circle transfer robots 254；Transmitting is mechanical Hand 254 includes horizontal slide 2541, lifting seat 2542 and left and right Pneumatic clamping jaw 2543, and the lifting seat 2542 is arranged in water On smooth seat 2541, the left and right setting of Pneumatic clamping jaw 2543 cooperates in 2542 lower end of lifting seat and the clamping of paper circle.

When upper paper loop mechanism works, paper circle is placed on ramp 253 by the crawl of transfer robots 254, in ramp It is slid downwards on 253 and overturns state in a vertical shape and fallen into paper coil 252, pushed on carrying mould 11 by scraping wings 251, at this time Upper mold 111 and lower die 112 the paper supply snare that fits connect, later upper mold and lower die relative movement tensioning paper circle, and round paper circle is upper Become square shape paper circle under the action of mould and lower die or oval paper circle, paper circle carry out rotation biography on the first turntable 1 with carrying mould It send.

Referring to attached drawing 4 and attached drawing 5, facial tissue molding machine 3 includes facial tissue stocking mechanism 31 and third turntable 32, described Third turntable 32 is equipped with forming tank 321, and there are three preferably forming tank 321 is spaced apart, interior step is equipped in forming tank 321 322, flanging mouth 323 is formed at interior step 322, the third turntable 332 includes turntable, index dial and power source, and turntable is longitudinal Arrangement；It is corresponding in turn on the rotation path of the forming tank 321 equipped with facial tissue transmission mechanism 33, molding delivery device 34 and de- material Delivery device 35, the facial tissue transmission mechanism 33 is connected facial tissue stocking mechanism 31 and forming tank 321 carries out facial tissue transmitting, it is described at Facial tissue in forming tank 321 is pushed into flanging mouth 323 by type delivery device 34, and the de- material delivery device 35 pushes away molding facial tissue Forming tank 321 out.

The molding delivery device 34 includes the first push plate 341, heating element and the first driving member 342, the heating part Part is arranged in the first push plate 341, and the first push plate 341 enters flanging mouth 323 by the transmission of the first driving member 342；Wherein first pass Moving part 342 includes cam link and the first drive rod, and the setting of the first drive rod is driven in first slide by cam link, the One drive rod is connected with the first push plate 341；Heating element is heating tube, and heating tube is arranged in the first push plate 341.

The de- material delivery device 35 includes the second push plate 351 and the second driving member 352, second push plate 351 by Second driving member 352 is driven across flanging mouth 323；Wherein the second driving member 352 includes the second cylinder and the second drive rod, and Two drive rods are arranged in second slide to be driven by the second cylinder, and the second drive rod is connected with the second push plate 351.

The facial tissue transmission mechanism 33 includes Suction cup assembly 331, third driving member 332 and rotating seat 333, the sucker Component 331 is driven transverse shifting by third driving member 332, and third driving member 332 is arranged on rotating seat 333；Wherein third passes Moving part 332 is third cylinder, and third cylinder is connected with Suction cup assembly 331.

The facial tissue stocking mechanism 31 includes paper frame 311 and the 4th driving member, and the front end of the paper frame 311 is equipped with paper delivery Limiting section 312, paper delivery limiting section 312 are the limited block for being set in paper frame front end, and the setting of the 4th driving member is pushed away in 311 rear end of paper frame Dynamic cardboard moves forward on paper frame 311；Wherein the 4th driving member is the 4th cylinder, and cylinder axis withstands cardboard.

When facial tissue molding machine works, the cardboard on paper frame 311 is pushed Forward by the 4th driving member, 311 front end of paper frame Cardboard carries out limit blocking by paper delivery limiting section 312, and Suction cup assembly 331 is under the action of third driving member 332 and rotating seat 333 Realize rotation and transverse shifting close to 311 front end of paper frame cardboard adsorb be detached from paper delivery limiting section 312, then by rotation with Transverse shifting is transferred in the forming tank 321 of third turntable 332, and then third turntable 32 rotates, and forming tank 321 and molding push Mechanism 34 is corresponding, and the first driving member 342 is driven the first push plate 341 and the cardboard in forming tank 321 is pushed into flanging mouth 323, phase Fold occurs under the blocking of interior step 322 and forms flanging for the cardboard outer rim answered, and third turntable 332 continues to rotate later, molding Slot 321 is corresponding with de- material delivery device 35, and the second driving member 352, which is driven the second push plate 351, will form completion in flanging mouth 323 Cardboard release flanging mouth 323 and forming tank 321.

Referring to attached drawing 6, blowing hot-air device 4 includes hot air source 41 and slide 42, and hot air source 41 is hot-blast stove, the cunning Seat 42 is driven by fourth drive part part and is moved, and fourth drive part part is cam link mechanism, and cam link mechanism drives slide 42 It moves on the slide rail, the slide 42 is equipped with Ventilated seat 43, is equipped with ventilation housing 44 in Ventilated seat 43,43 front end of Ventilated seat is set There is cover board 45,45 outer peripheral surface of cover board and 43 front end face of Ventilated seat are the tapered surface to match, i.e., cover board outer peripheral surface is back taper face, Ventilated seat front end face is also matched back taper face, and arranged for interval is formed between 43 front end face of 45 outer peripheral surface of cover board and Ventilated seat Outlet air gap 46,43 rear end of Ventilated seat connect hot air source 41 by hose, alternatively, 43 rear end of Ventilated seat and hot air source 41 are straight Docking is connect to be connected.

The ventilation housing 44 is T-type cavity, and leading portion cavity internal diameter is greater than back segment cavity internal diameter, the reasonable cloth of ventilation housing 44 It sets, improves hot wind transmission efficiency, be equipped with partition 47 in the leading portion cavity, partition 47 fits with cover board 45, and on partition 47 Stomata 48 is irised out equipped with one, the connection corresponding with outlet air gap 46 of venthole 48 carries out guiding conveying to hot wind, improves hot wind and utilize Rate.

When blowing hot-air device works, slide 42 is moved on the slide rail by the transmission of fourth drive part part, and Ventilated seat 43 pastes Nearly paper circle, outlet air gap 46 is corresponding with paper circle inner wall, and the hot gas that hot-blast stove generates is transmitted in ventilation housing 44, goes out through partition 47 Stomata 48, the orientation of outlet air gap 46 carry out blowing hot-air softening to the colloid on paper circle inner wall.

Referring to attached drawing 7, crimping unit 5 includes to pre-fold station 51 and eventually folding station 52, pre-folds station 51 and eventually folding station 52 include moveable hemming die 53, and specially hemming die 53 is arranged in fixing seat 54, and fixing seat 54 is movably arranged On slide, fixing seat 54 is connected with power source transmission, and power source is cam link mechanism, and hemming die 53 is equipped with groove 531, The inner wall of groove 531 is inclined outwardly to form flanging guide surface 532, and 531 bottom of groove is equipped with arc flanging groove 533, the flanging Guide surface 532 is connected with 533 phase of arc flanging groove, and the arc flanging groove 533 for pre-folding station 51, which has, pre-folds the angle R, rolls over eventually The arc flanging groove 533 of station 52 has the folding angle R eventually, pre-folds the angle R and is greater than the folding angle R eventually.

When crimping unit works, by the transmission of paper circle by pre-folding station 51, power source drive fixing seat 54 is moved up in slide It is dynamic, so that hemming die 53, close to paper circle bottom, paper circle bottom touches the flanging guide surface 532 of hemming die 53, guided in flanging Enter arc flanging groove 533 under the guiding function in face 532 and carry out pre- flanging, similarly carries out whole folding by folding station 52 eventually later Side.

Referring to attached drawing 1, lid arrangement 7, include the Pneumatic clamping jaw 71 and conveyer belt of scalable movement and spinning movement out 72, Pneumatic clamping jaw 71 sets up left clamping jaw and right clamping jaw separately, and left and right clamping jaw, which cooperates, clamps paper circle, and Pneumatic clamping jaw 71 is by rotary pneumatic Cylinder driving is rotated up and down movement, and drives expanding-contracting action, the corresponding mobile clamping bearing seat 11 of Pneumatic clamping jaw 71 by straight line cylinder On paper circle, the upper die and lower die of bearing seat 11 move towards release paper circle, and the paper circle of clamping is sent into conveyer belt by Pneumatic clamping jaw 71 72 are sent outside.

In conclusion the above is only the preferred embodiments of the present utility model only, it is not intended to limit the utility model Protection scope.Within the spirit and principle of the utility model, any modification, equivalent replacement, improvement and so on should all wrap Containing being within the protection scope of the utility model.

Claims (10)

1. paper cap molding equipment includes the first turntable, carrying mould is equipped at intervals on the first turntable etc., it is characterised in that: described Carrying mould includes the upper die and lower die of relative movement, and upper mold and lower die, which cooperate, is tensioned paper circle；First turntable periphery It is corresponding in turn to equipped with paper circle molding machine, facial tissue molding machine, blowing hot-air device, crimping unit, embossing device and lid arrangement out.

2. paper cap molding equipment as described in claim 1, it is characterised in that: the paper circle molding machine includes second turn Disk is equipped at intervals with die holder on the second turntable etc., die holder includes the internal model of rotary setting and the external mold of lifting setting, and external mold is arranged In internal model periphery；Second turntable periphery be corresponding in turn to equipped with paper circle transport mechanism, water line shaping mechanism, glue-spraying mechanism and Upper paper loop mechanism；The upper paper loop mechanism is mutually connected with the first turntable.

3. paper cap molding equipment as claimed in claim 2, it is characterised in that: the paper circle transport mechanism includes conveyer belt, Conveyer belt front end is equipped with left and right clamp bar, and left and right clamp bar is arranged in above the internal model of die holder, and liftable is equipped with above left and right clamp bar Ejection part, in internal model of the paper circle by ejection part roof fall to die holder between left and right clamp bar.

4. paper cap molding equipment as claimed in claim 2, it is characterised in that: the water line shaping mechanism includes disc Impression knife and the first driving part, the impression knife is rotatably arranged on tool apron, and tool apron is movably arranged, the die holder it is interior Mould outer peripheral surface is equipped with impression slot, and impression knife is matched with impression slot, and the internal model transmission of first driving part and die holder is matched It closes.

5. paper cap molding equipment as claimed in claim 2, it is characterised in that: the glue-spraying mechanism includes FE Glue Gun, induction Device and the second driving part, FE Glue Gun are connected with inductor signal, FE Glue Gun be arranged in above die holder in the paper circle in internal model Wall is corresponding；The transmission cooperation of the internal model of second driving part and die holder.

6. paper cap molding equipment as claimed in claim 2, it is characterised in that: the upper paper loop mechanism includes scraping wings and Three driving parts, scraping wings are driven by third driving part and push to paper circle on carrying mould；The carrying mould and scraping wings it Between be equipped with the paper coil for carrying vertical paper circle, be equipped with the ramp being mutually connected above paper coil；It is set above the ramp There are paper circle transfer robots, the paper circle on die holder is transferred to ramp by paper circle transfer robots.

7. paper cap molding equipment as described in claim 1, it is characterised in that: the facial tissue molding machine includes facial tissue storage Mechanism and third turntable, the third turntable are equipped with forming tank, and interior step is equipped in forming tank, forms flanging at interior step Mouthful, it is corresponding in turn on the rotation path of the forming tank equipped with facial tissue transmission mechanism, molding delivery device and de- material delivery device, Facial tissue transmission mechanism linking facial tissue stocking mechanism and forming tank carry out facial tissue transmitting, and the molding delivery device is by forming tank Interior facial tissue is pushed into flanging mouth, and molding facial tissue is released forming tank by the de- material delivery device.

8. paper cap molding equipment as described in claim 1, it is characterised in that: the blowing hot-air device includes hot air source and cunning Seat, the slide are driven by fourth drive part part and are moved, and the slide is equipped with Ventilated seat, are equipped with ventilation housing in Ventilated seat, Ventilated seat front end is equipped with cover board, and cover board outer peripheral surface and Ventilated seat front end face are the tapered surface to match, and cover board outer peripheral surface and logical Arranged for interval forms outlet air gap between wind seat front end face, and the ventilation base rear end connects hot air source.

9. paper cap molding equipment as claimed in claim 8, it is characterised in that: the ventilation housing is T-type cavity, leading portion cavity Internal diameter is greater than back segment cavity internal diameter, is equipped with partition in the leading portion cavity, and partition fits with cover board, and partition is equipped with a circle Venthole, venthole connection corresponding with outlet air gap.

10. paper cap molding equipment as described in claim 1, it is characterised in that: the crimping unit include pre-fold station and Folding station eventually, pre-folds station and folding station includes moveable hemming die eventually, and hemming die is equipped with groove, the inner wall of groove It is inclined outwardly to form flanging guide surface, bottom portion of groove is equipped with arc flanging groove, and the flanging guide surface is mutually held in the mouth with arc flanging groove It connects, the arc flanging groove for pre-folding station, which has, pre-folds the angle R, and the arc flanging groove for rolling over station eventually has the folding angle R eventually, pre-folds R Angle is greater than the folding angle R eventually.