CN111230954B

CN111230954B - Resin sheet cutting machine

Info

Publication number: CN111230954B
Application number: CN201911172311.5A
Authority: CN
Inventors: 藤井正典
Original assignee: Konan Design Industries Co ltd
Current assignee: Konan Design Industries Co ltd
Priority date: 2018-11-28
Filing date: 2019-11-26
Publication date: 2022-09-27
Anticipated expiration: 2039-11-26
Also published as: CN111230954A; JP2020082298A; TWI799653B; TW202106480A; JP7094013B2

Abstract

The invention provides a resin sheet cutting machine which can cut hard resin sheets such as acrylic resin and the like in a short cutting time in a mode of not generating cutting chips and can ensure good cutting surface quality. The method comprises the steps of lowering an upper blade (9) in a state that a resin sheet passes between the upper blade (9) and a lower blade (10), and driving the upper blade (9) and the lower blade (10) into the resin sheet, thereby generating brittle fracture to cut the resin sheet, wherein the thickness (T1) of a blade main body (9a) of the upper blade (9) is smaller than the thickness (T2) of a blade main body (10a) of the lower blade (10), so that the upper blade (9) can drive into the resin sheet more easily than the lower blade (10). Therefore, on the basis of cutting in a short time without generating cutting chips, the difference of driving amounts of the upper cutter (9) and the lower cutter (10) caused by the influence of the recoil of the lifting mechanism for lifting the upper cutter (9) can be reduced, and good cut surface quality can be ensured.

Description

Resin sheet cutting machine

Technical Field

The present invention relates to a resin sheet cutting machine for cutting a hard resin sheet.

Background

A hard resin sheet is generally produced by extrusion molding, and is continuously extruded by an extruder for the extrusion molding, and then cut into a predetermined length to obtain a product. As a resin sheet cutter for cutting (hereinafter, also simply referred to as "cutter"), many cutters move a circular saw in a cutting direction (sheet width direction) while moving in an extrusion direction (sheet flow direction) in accordance with an extrusion speed of an extruder.

However, when the resin sheet is cut with a circular saw, debris (chips) is generated at the time of cutting, and therefore, a separate process for removing the debris adhering to the resin sheet by static electricity is required, and the debris sandwiched between the protective films covering the upper and lower surfaces of the resin sheet and the cutter may cause quality defects in the subsequent process. Further, since the time taken for one cutting is relatively long, it is sometimes difficult to apply the method to the production of a wide or short resin sheet, and when the extrusion speed is high, it is necessary to extend the movable range of the circular saw in the sheet flowing direction in cooperation with the high extrusion speed, and the entire cutting machine is increased in size.

In view of this, the present applicant has developed a cutting machine (hereinafter referred to as a "single-blade cutting machine") that cuts a resin sheet by lowering a blade of a blade having a plate shape, which is held above a resin sheet passing position, until the blade penetrates the resin sheet in a thickness direction. In this single-blade cutting machine, the resin sheet can be cut without generating chips, so that a process of chip disposal is not required, and there is no concern that the chips cause quality defects in a later process. Further, since the cutting can be performed in a shorter time than a cutting machine using a circular saw, the application range for manufacturing a wide and short resin sheet is wide, and even when the extrusion speed is high, the movable range of the cutter in the sheet flowing direction can be made short, and the entire cutting machine can be made compact (see patent document 1).

The single-blade cutting machine can ensure very high quality of cut surfaces in cutting polycarbonate and resin sheets with the same grade hardness as polycarbonate. However, when a resin sheet to be cut is a resin having a very small value of elongation and impact strength compared to polycarbonate and having physical properties close to those of glass, for example, polymethyl methacrylate resin (PMMA), general-purpose polystyrene (GPPS), methyl methacrylate/styrene copolymer resin (MS), or the like called acrylic resin, brittle fracture occurs from the driven position at the moment when a cutter is driven, and the resin sheet is broken and cut, so that the cut surface has poor perpendicularity to the front surface and the back surface and has a rough surface finish, and a line as a boundary between the back surface and the cut surface does not become a straight line and has many irregularities.

On the other hand, as a cutting machine for a hard resin sheet such as an acrylic resin, there is proposed a cutting machine: the starting point of the brittle fracture is generated by striking a cutter on the upper and lower surfaces of the resin sheet, and the brittle fracture is propagated in the sheet thickness direction, so that the cutting can be performed in a short time without generating chips. In this cutting machine, in order to smoothly obtain a good cut surface, it is important to minimize the deviation of the driving timing of the upper and lower blades and the blade tip interval in the sheet flow direction (for example, see patent document 2).

Patent document 1: japanese patent laid-open publication No. 2018-24057

Patent document 2: japanese laid-open patent publication No. 2005-59156

However, in the cutting machine proposed in patent document 2 and the like, in general, the upper blade is held by a blade holder attached to the elevating mechanism, and the lower blade having the same specification as the upper blade is held in a fixed manner, and when cutting is performed, the upper blade and the blade holder are lowered integrally, and the resin sheet is driven in simultaneously with the lower blade, and therefore the driving amount of the upper blade is smaller than that of the lower blade due to the influence of backlash of the elevating mechanism.

Further, if the driving amount of the resin sheet by the upper blade is smaller than that by the lower blade, as schematically shown in fig. 10, even if the deviation of the blade pitch between the upper blade 51 and the lower blade 52 is adjusted to be small, the perpendicularity of the fracture surface extending from the driving position of the lower blade 52 is low, and the fracture surfaces extending from the driving positions of the upper and

lower blades

51, 52 are continuous with each other at the third fracture surface to cut the resin sheet S, and at this time, chips broken into powder are likely to be generated, and whisker-like projections are likely to be generated at the third fracture surface to degrade the quality of the fracture surface.

Disclosure of Invention

Accordingly, an object of the present invention is to provide a resin sheet cutting machine capable of cutting a hard resin sheet such as acrylic resin in a short cutting time without generating chips and ensuring good quality of cut surfaces.

In order to solve the above problem, a resin sheet cutting machine according to the present invention includes: a band plate-shaped upper blade which is held to be capable of ascending and descending above a passing position of a resin sheet to be cut; a lower blade having a plate shape, the lower blade being fixedly held below a passing position of the resin sheet; and a lifting mechanism for lifting the upper blade, wherein the upper blade and the lower blade are arranged such that blade tips formed on one side of the respective blade bodies face each other in the vertical direction, and the upper blade and the lower blade are lowered in a state where a resin sheet is passed between the upper blade and the lower blade to drive the upper blade and the lower blade into the resin sheet, whereby the resin sheet is cut by brittle fracture starting from the driving positions of the blade tips of the upper blade and the lower blade, and in the resin sheet of the cutting machine, the thickness dimension of the blade body of the upper blade is smaller than the thickness dimension of the blade body of the lower blade.

That is, in a resin sheet cutting machine in which a resin sheet is brittle-broken and cut in a short time without generating chips by lowering an upper blade held so as to be able to be raised and lowered and driving the upper blade and a lower blade held so as to be fixed into the resin sheet, the upper blade is made easier to drive into the resin sheet than the lower blade by making the thickness dimension of the blade body of the upper blade smaller than the thickness dimension of the blade body of the lower blade, and thus a difference in the driving amount between the upper blade and the lower blade caused by the influence of backlash of a raising and lowering mechanism can be reduced and good cut surface quality can be ensured.

Preferably, the ratio of the thickness dimension of the blade main body of the upper blade to the thickness dimension of the blade main body of the lower blade is 1/1.5 to 1/4.

Further, by adopting a structure in which the upper blade and the lower blade are held by the blade holder detachably attached to the cutter body, respectively, and can be replaced integrally with the blade holder, the replacement work of the upper blade and the lower blade can be realized in a short time.

In addition, the driving amount of the resin sheet by the upper blade and the lower blade can be easily adjusted by a configuration in which a wedge is assembled at a position sandwiched in the vertical direction between the cutter holder holding the lower blade and the cutter body, and the wedge is moved in the horizontal direction, whereby the position of the lower blade can be adjusted in the vertical direction.

In addition, if the tool holder holding the lower blade is configured to be replaceable with the tool receiving member receiving the tool bit of the upper blade, the tool holder can be simply replaced with the tool receiving member, and the conventional single blade cutting machine can be easily switched to use.

In the resin sheet cutting machine of the present invention, as described above, the upper blade is lowered in a state where the resin sheet is passed between the upper blade held so as to be able to ascend and descend and the lower blade held so as to be fixed, the upper blade and the lower blade are driven into the resin sheet, thereby causing brittle fracture to cut the resin sheet, and the upper blade is driven into the resin sheet more easily than the lower blade by making the thickness dimension of the blade body of the upper blade smaller than the thickness dimension of the blade body of the lower blade.

Drawings

Fig. 1 is a front view of a resin sheet cutter of an embodiment.

Fig. 2 is a left side view of fig. 1.

Fig. 3 is an enlarged sectional view taken along line III-III of fig. 1.

Fig. 4 is an external perspective view (a state viewed from a lower side) of the tool holder for upper blade of fig. 3.

Fig. 5 is an external perspective view of a fixed holding member in which the tool holder for lower blade of fig. 3 is fitted.

Fig. 6 is an explanatory view of the dimensions of the upper blade and the lower blade of fig. 3.

Fig. 7 is an explanatory diagram of the cutting operation corresponding to fig. 3.

FIG. 8 is a schematic view for explaining a cutting phenomenon in the cutting machine of FIG. 1.

Fig. 9 is a sectional view of a main part for explaining another use mode of the cutting machine of fig. 1.

Fig. 10 is a schematic diagram illustrating a cutting phenomenon in a conventional cutting machine.

Description of the reference numerals

1 … base station; 2 … rectangular frame; 3 … workbench; 4 … lifting and lowering means; 5 … column members; 6 … crank mechanism (lifting mechanism); 7. 8 … tool holder; 9, feeding a knife 9 …; 9a … knife body; 9b … tool bit; 10 … lower cutter; 10a … knife body; 10b … tool bit; 11 … securing the retaining member; 12 … wedge; 21 … pressing plate; 22 … press bolt; 23 … an elastic member; 24 … tool receiving member.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in fig. 1 and 2, the resin sheet cutting machine comprises a rectangular plate-shaped base 1, a pair of rectangular frames 2 standing on the upper surfaces of both side portions of the base 1, a table 3 straddling between the upper surfaces of the upper side portions of both the rectangular frames 2, a flat plate-shaped lifting member 4 disposed above the table 3, column members 5 fixed to both sides of the lifting member 4, and a crank mechanism (lifting mechanism) 6 for lifting the lifting member 4 and the column members 5 integrally.

Tool holders

7 and 8 extending in the left-right direction of the cutter body (left-right direction in fig. 1) are attached to the lower edge portion of the lifting member 4 and the upper surface of the table 3, an upper blade 9 having a plate shape is held by the upper tool holder 7, and a lower blade 10 having a plate shape is held by the lower tool holder 8.

In a state where the resin sheet S continuously extruded from the extruder (not shown) is passed between the upper blade 9 and the lower blade 10, the crank mechanism 6 is operated to lower the upper blade 9 integrally with the cutter holder 7, the lifting member 4, and the two-column member 5, thereby cutting the resin sheet S (see fig. 7). In this cutting machine, a hard resin sheet such as an acrylic resin having a smaller value of elongation and impact strength than polycarbonate is used as a cutting object.

The base 1 is held so as to be capable of reciprocating in the sheet flow direction, and is connected to a servomotor via a motion conversion mechanism that converts rotary motion into linear motion, while the illustration of the base 1 is omitted. When the cutting machine performs the cutting operation, the servo motor is driven to move downstream of the sheet flow in accordance with the extrusion speed of the extruder, and the sheet returns to the original position after the cutting is completed.

As shown in fig. 1 and 3, a long fixing member 11 extending in the left-right direction of the cutter body is fixed to the upper surface of the table 3 so as to face the lower edge of the lifting member 4, and a wedge 12 for adjusting the vertical position of the lower blade 10 and the tool holder 8 (for holding the lower blade 10) is fitted into a rectangular groove 11a provided in the upper surface of the fixing member 11. Thus, the upper blade 9 held so as to be movable upward and downward above the passing position of the resin sheet S and the lower blade 10 fixedly held below the passing position of the resin sheet S are arranged in a state where the respective blade heads face each other in the vertical direction.

Here, a wedge 12 is assembled at a position sandwiched in the vertical direction between a fixed holding member 11 fixed to the table 3 of the cutter body and the lower cutter holder 8. The upper surface of the wedge 12 and the lower surface of the lower blade tool holder 8 facing thereto are inclined surfaces inclined at the same angle with respect to the left-right direction of the cutter body. Thus, when the wedge 12 is moved in the horizontal direction, the vertical position of the lower blade 10 can be adjusted integrally with the tool holder 8 for the lower blade.

Further, L-shaped side plates 13 are erected on both side portions of the upper surface of the table 3 as viewed from the side, and guide plates 14 for guiding the column member 5 in the vertical direction are fixed to the side plates 13. Each column member 5 penetrates the table 3 in the vicinity of the position where the side plate 13 stands, and is connected to the crank mechanism 6 by a leg portion 5a provided on the lower end side thereof.

The crank mechanism 6 includes a servomotor 15 provided on the base 1, a crankshaft 17 connected to the servomotor 15 by a pulley 16, and a connecting member 18 rotatably connected to the crankshaft 17 and the leg portion 5a of each column member 5. Both ends of the crankshaft 17 are rotatably supported by a support member 19, and the support member 19 is provided on the lower surface side of the table 3. Thus, when the servo motor 15 is driven, the column members 5 coupled to the crankshaft 17 are guided by the guide plate 14 and move up and down in accordance with the rotation of the crankshaft 17, and the up-and-down member 4 to which the column members 5 are fixed, the tool holder 7 attached to the up-and-down member 4, and the upper blade 9 held by the tool holder 7 also move up and down integrally.

As shown in fig. 1 and 3, the vertically movable member 4 has a plurality of windows 4a cut in a lower portion thereof, and mounting bolts 20 are screwed from lower edges of the windows 4a to a tool holder 7 (for an upper blade) that holds the upper blade 9. The head of each mounting bolt 20 is sized to be easily grasped by hand so that the lifting member 4 can be easily attached to and detached from the tool holder 7 for feeding.

As shown in fig. 3 and 4, the upper blade tool holder 7 is a long member formed in an コ -shaped cross section, and the majority of the upper blade 9 is inserted into the コ -shaped cross section in a downward posture together with the plate-shaped pressing plate 21. Then, the pressing plate 21 is pressed by the pressing bolt 22 screwed from the outer side surface of one (downstream side) side wall thereof, and the upper blade 9 is sandwiched between the pressing plate 21 and the other (upstream side) side wall. Thereby, the upper blade 9 is held so as to be able to move up and down integrally with the tool holder 7 above the passing position of the resin sheet S.

As shown in fig. 3 and 5, the cutter holder 8 for the lower blade is slightly different in size from the cutter holder 7 for the upper blade but has the same basic structure, and the lower blade 10 is fixedly held in an upward posture below the passing position of the resin sheet S.

Further, long elastic members 23 having a rectangular cross section and made of sponge are joined to the lower surfaces of both side walls of the upper blade holder 7 and the upper surfaces of both side walls of the lower blade holder 8. The upper elastic member 23 is formed to be thicker than the height at which the upper blade 9 protrudes from the side wall of the tool holder 7, and the lower elastic member 23 is formed to be thicker than the height at which the lower blade 10 protrudes from the side wall of the tool holder 8. Accordingly, in a natural state, neither the upper blade 9 nor the lower blade 10 protrudes from the elastic member 23, and an accident such as the operator being cut the finger is less likely to occur. The cutting of the resin sheet S can be stably performed in a state where the resin sheet S is sandwiched by the upper and lower elastic members 23 being compressed.

As shown in fig. 6, the upper blade 9 and the lower blade 10 are each composed of a

blade body

9a, 10a having a constant thickness and a

cutting tip

9b, 10b having a triangular cross-section formed on one side of the

blade body

9a, 10a, and carbon tool steel, high-speed steel, cemented carbide, stainless steel, ceramics, or the like is used as a material thereof. The angles of the

cutting edges

9b and 10b of the upper blade 9 and the lower blade 10 are the same (about 15 to 30 degrees), and the upper blade 9 is formed thinner than the lower blade 10 with respect to the

blade bodies

9a and 10 a. Specifically, the thickness T1 of the blade body 9a of the upper blade 9 is in the range of 0.2 to 2.0mm, the thickness T2 of the blade body 10a of the lower blade 10 is in the range of 0.5 to 3.0mm, and the ratio T1/T2 of the two is set to 1/1.5 to 1/4.

The mounting positions of the upper blade 9 and the lower blade 10 are adjusted so that the difference in the vertical distance between the

blade tips

9b and 10b is 0.2mm or less and the difference in the vertical distance between the

blade tips

9b and 10b in the sheet flow direction is 0.1mm or less.

Next, the cutting operation of the cutting machine will be described. Although not shown, a roller conveyor for supporting the lower surface of the resin sheet from the extruder to the front of the cutter, a film coating device for coating the upper and lower surfaces of the resin sheet with a protective film, a labeling machine for adhering a label to the upper surface of the resin sheet in the vicinity of the downstream end of the roller conveyor, and a take-off roll for taking off the resin sheet from the downstream end of the roller conveyor and feeding the resin sheet to the cutter are provided between the cutter and the extruder.

That is, the resin sheet continuously extruded from the extruder flows downstream with its lower surface supported by the roller conveyor, and the film coating device coats the upper and lower surfaces with the protective film, and after the label is stuck to the upper surface by the labeling machine, the resin sheet is sent to the cutter by the pull roll.

In the cutting machine, when the cutting position of the resin sheet S passing between the upper blade 9 and the lower blade 10 reaches a predetermined position, the base 1 starts moving downstream at the extrusion speed of the extruder, and the column member 5, the elevation member 4, the cutter holder 7, and the upper blade 9 start moving down integrally by the operation of the crank mechanism 6 before and after the movement. As shown in fig. 7, after the resin sheet S is clamped by compressing the elastic members 23 of the upper and

lower tool holders

7, 8, when the resin sheet S is driven by the upper and

lower blades

9, 10, brittle fracture occurs starting from the driving position, and the resin sheet S is cut.

Here, in the upper blade 9 and the lower blade 10, the blade body 9a of the upper blade 9 is formed thinner than the blade body 10a of the lower blade 10 as described above, and therefore the upper blade 9 is easier to drive the resin sheet S than the lower blade 10. Therefore, even if there is an influence of the backlash of the crank mechanism 6 that lowers the upper blade 9, the difference in the driving amount of the resin sheet S by the upper blade 9 and the lower blade 10 can be suppressed to be small, and as schematically shown in fig. 8, the resin sheet S can be cut by extending the broken surfaces from the driving positions of the upper blade 9 and the lower blade 10 at substantially right angles to the surface and the back of the resin sheet S and continuing the broken surfaces to each other in the vicinity of the center in the thickness direction of the resin sheet S. Therefore, it is difficult to generate powder-like chips at the time of cutting and to generate whisker-like projections on the cut surface, and a flat cut surface can be obtained.

The cut resin sheets S are then sent to the next step by a discharge conveyor (not shown) provided downstream of the cutting machine. In the cutting machine after the cutting operation, the base 1 moves to the upstream side and returns to the original position, and the column member 5, the lifting member 4, the tool holder 7, and the upper blade 9 are integrally lifted and returned to the original position.

In the resin sheet cutting machine having the above-described configuration, the upper blade 9 is lowered in a state where the resin sheet S is passed between the upper blade 9 held so as to be able to ascend and descend and the lower blade 10 held so as to be fixed, and the upper blade 9 and the lower blade 10 are driven into the resin sheet S, whereby brittle fracture occurs and cutting is performed, and therefore cutting can be performed in a short time without generating chips.

Further, since the thickness T1 of the blade body 9a of the upper blade 9 is made smaller than the thickness T2 of the blade body 10a of the lower blade 10, the upper blade 9 can be driven into the resin sheet S more easily than the lower blade 10, and therefore, as compared with the case where the upper blade and the lower blade are made to have the same specification, it is possible to reduce the difference in the driving amount between the upper blade 9 and the lower blade 10 due to the influence of the backlash of the crank mechanism 6, and to ensure good cut surface quality.

Further, since the upper blade 9 and the lower blade 10 are held by the

blade holders

7 and 8, respectively, and the

blade holders

7 and 8 are detachably attached to the cutter body, the upper blade 9 can be replaced integrally with the blade holder 7, and the lower blade 10 can be replaced integrally with the blade holder 8. This replacement operation can be performed in a short time without requiring a thorough operation, and therefore, the efficiency of the entire resin sheet manufacturing operation can be significantly improved as compared with a case where the upper blade and the lower blade are separately attached to and detached from the cutting machine.

Further, since the wedge 12 assembled between the tool holder 8 for the lower blade and the fixed holding member 11 is moved in the horizontal direction, the vertical position of the lower blade 10 can be adjusted integrally with the tool holder 8, and thus the driving amount of the resin sheet S by the upper blade 9 and the lower blade 10 can be easily adjusted.

When the resin sheet to be cut is a resin sheet made of polycarbonate or a resin having a physical property value such as elongation of the same level as that of polycarbonate, the cutter holder 8 for the lower blade 10 and the lower blade can be simply switched to the conventional single blade cutting machine and used by replacing it with the cutter receiving member 24 that receives the tip of the upper blade 9, as shown in fig. 9.

The resin sheet cutting machine of the present invention is not limited to cutting the resin sheet continuously extruded from the extruder as in the embodiment, and can be applied to cutting a part of the resin sheet already formed in a constant size in a batch process. In a cutting machine for batch type cutting, a moving mechanism of a base station is not required.

Claims

1. A resin sheet cutting machine is characterized in that,

the resin sheet cutting machine comprises: a band plate-shaped upper blade which is held to be capable of ascending and descending above a passing position of a resin sheet to be cut; a lower blade having a plate shape, the lower blade being fixedly held below a passing position of the resin sheet; and a lifting mechanism for lifting the upper blade, wherein the upper blade and the lower blade are arranged such that blade tips formed on one side of the respective blade bodies face each other in the vertical direction, and the upper blade and the lower blade are lowered in a state where a resin sheet is passed between the upper blade and the lower blade to drive the upper blade and the lower blade into the resin sheet, thereby causing brittle fracture starting from the driving positions of the blade tips of the upper blade and the lower blade to cut the resin sheet,

the thickness dimension of the knife main body of the upper knife is smaller than that of the knife main body of the lower knife, and the ratio of the thickness dimensions of the knife main bodies of the upper knife and the lower knife is 1/1.5-1/4.

2. The resin sheet cutting machine according to claim 1,

the upper blade and the lower blade are respectively held by a blade holder, which is detachably attached to the cutter body, and are replaceable integrally with the blade holder.

3. The resin sheet cutting machine according to claim 2,

a wedge is assembled at a position sandwiched between the cutter holder holding the lower blade and the cutter body in the vertical direction, and the lower blade can be adjusted in position in the vertical direction by moving the wedge in the horizontal direction.

4. The resin sheet cutting machine according to claim 2,

the tool holder holding the lower blade can be replaced with a tool receiving member receiving the tool bit of the upper blade.