JP7094013B2 - Resin sheet cutting machine - Google Patents

Description

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

A hard resin sheet is generally manufactured by extrusion molding, is continuously extruded from an extruder that performs the extrusion molding, and then cut into a predetermined length to obtain a product. As a resin sheet cutting machine (hereinafter, also simply referred to as a “cutting machine”) that cuts the cutting, the circular saw is moved in the extrusion direction (sheet flow direction) following the extrusion speed of the extruder to cut in the cutting direction (sheet). There are many things that can be moved in the width direction as well.

However, when the resin sheet is cut with a circular saw, chips (chips) are generated during cutting, so a separate process for removing the chips adhering to the resin sheet due to static electricity is required, and cutting with an extruder is required. Chips sandwiched between the protective film coated on the upper and lower surfaces of the resin sheet between the machines and the resin sheet may cause quality defects in the subsequent process. In addition, since the time required for one cutting is relatively long, it may be difficult to apply it to the production of wide or short resin sheets, and if the extrusion speed is high, the sheet flow direction of the circular saw is adjusted accordingly. It is necessary to take a long movable range of the saw, and there is also a problem that the entire cutting machine becomes large.

On the other hand, the applicant cuts the resin sheet by lowering the strip-shaped blade held above the resin sheet passing position until the cutting edge penetrates the resin sheet in the thickness direction. We have developed a machine (hereinafter referred to as "single-edged cutting machine"). Since this single-edged cutting machine can cut the resin sheet without generating chips, the process of chip processing is unnecessary, and there is no possibility that the chips cause quality defects in the subsequent process. In addition, since cutting can be performed in a shorter time than using a circular saw, the range of application to the production of wide and short resin sheets is wide, and even when the extrusion speed is high, the cutting tool flow direction The movable range is short, and the entire cutting machine can be made compact (see Patent Document 1).

The above-mentioned single-edged cutting machine can ensure extremely high cut surface quality in cutting polycarbonate and resin sheets having the same level of hardness. However, the resin sheet to be cut has a much smaller elongation and izot strength value than polycarbonate and has physical properties similar to those of glass, such as polymethyl methacrylate resin (PMMA) called acrylic resin and general-purpose polystyrene (GPPS). In the case of methyl methacrylate / styrene copolymer resin (MS), etc., the moment the blade is driven, brittle fracture occurs starting from the driving position, and the cut surface is cut by cracking. The squareness with respect to the front and back surfaces is poor and the surface roughness is also rough, and the line that is the boundary between the back surface and the cut surface is not a straight line and has a large number of irregularities.

On the other hand, as a cutting machine for a hard resin sheet such as acrylic resin, a blade is driven into both the upper and lower surfaces of the resin sheet to generate a starting point of brittle fracture, and the brittle fracture is propagated in the sheet thickness direction to generate chips. It has been proposed that cutting can be performed in a short time without generating it. In this cutting machine, in order to obtain a smooth and good cut surface, it is important to minimize the deviation of the cutting timing of the upper and lower blades and the distance between the cutting edges in the sheet flow direction (for example, Patent Documents). See 2nd class.).

Japanese Unexamined Patent Publication No. 2018-24507 Japanese Unexamined Patent Publication No. 2005-59156

However, in the cutting machine proposed in Patent Document 2 and the like, the upper blade is generally held by a blade holder attached to the elevating mechanism, and the lower blade having the same specifications as the upper blade is fixedly held. At the time of cutting, the upper blade is lowered integrally with the blade holder and driven into the resin sheet at the same time as the lower blade. It will be less than the amount of driving.

When the amount of the upper blade driven into the resin sheet is smaller than that of the lower blade, as shown schematically in FIG. 10, even if the deviation between the cutting edge distance between the upper blade 51 and the lower blade 52 is adjusted to be small, the lower blade is lowered. The squareness of the fracture surface extending from the driving position of the blade 52 becomes worse, and the fracture surfaces extending from the driving positions of the upper and lower blades 51 and 52 continuously cut the resin sheet S at the third fracture surface. At that time, chips that are broken into powder are likely to be generated, or whisker-like protrusions are generated on the third fracture surface, and the quality of the cut surface is likely to deteriorate.

Therefore, it is an object of the present invention 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 cut surface quality.

In order to solve the above problems, the present invention has a strip-shaped upper blade that is held up and down above the passing position of the resin sheet to be cut, and is fixedly held below the passing position of the resin sheet. A strip-shaped lower blade is provided, and an elevating mechanism for raising and lowering the upper blade is provided. The upper blade and the lower blade are arranged, and the upper blade is lowered while the resin sheet is passed between the upper blade and the lower blade, and the upper blade and the lower blade are driven into the resin sheet, whereby the upper blade and the lower blade are formed on the resin sheet. In a resin sheet cutting machine that causes brittle fracture starting from the cutting position of the blade edge and cuts, 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, by lowering the upper blade held so as to be able to move up and down and driving the lower blade fixedly held with the upper blade into the resin sheet, brittle fracture occurs in the resin sheet and chips are not generated. In a resin sheet cutting machine that can cut in a short time, the thickness dimension of the blade body of the upper blade is made smaller than the thickness dimension of the blade body of the lower blade, making it easier to drive the upper blade into the resin sheet than the lower blade. By doing so, the difference in the driving amount between the upper and lower blades due to the backlash of the elevating mechanism is reduced, and good cut surface quality can be ensured.

The ratio of the thickness dimension of the blade body of the upper blade to the lower blade is preferably 1 / 1.5 to 1/4.

Further, the upper blade and the lower blade are each held by a blade holder detachably attached to the main body of the cutting machine, and if a configuration is adopted in which the upper blade and the lower blade can be replaced integrally with the blade holder, the upper blade is used. And the lower blade can be replaced easily in a short time.

A cotter is incorporated at a position where the blade holder holding the lower blade and the cutting machine main body are sandwiched in the vertical direction, and by moving the cotter in the horizontal direction, the lower blade is positioned in the vertical direction. If the configuration is adjustable, the amount of driving of the upper and lower blades into the resin sheet can be easily adjusted.

Further, if the blade holder that holds the lower blade is replaceable with a blade receiving member that receives the cutting edge of the upper blade, the conventional blade holder can be easily replaced with the blade receiving member. It will be possible to switch to the single-edged cutting machine of.

In the resin sheet cutting machine of the present invention, as described above, the upper blade is lowered while the resin sheet is passed between the upper blade held so as to be able to move up and down and the lower blade held fixedly. By driving the blade and lower blade into the resin sheet, brittle fracture occurs and the resin sheet is cut, and the thickness dimension of the blade body of the upper blade is made smaller than the thickness dimension of the blade body of the lower blade. Since the upper blade is easier to drive into the resin sheet than the lower blade, cutting can be done in a short time without generating chips, and the upper and lower blades are driven due to the backlash of the elevating mechanism that raises and lowers the upper blade. The difference in quantity is small, and good cut surface quality can be ensured.

Front view of the resin sheet cutting machine of the embodiment Left side view of FIG. Enlarged sectional view taken along line III-III in FIG. External perspective view of the blade holder for the upper blade in FIG. 3 (viewed from below) External perspective view of the fixed holding member into which the blade holder for the lower blade of FIG. 3 is fitted. Explanatory drawing of dimensions of upper blade and lower blade of FIG. Explanatory diagram of cutting operation corresponding to FIG. Schematic diagram illustrating a cutting phenomenon in the cutting machine of FIG. Sectional drawing of the main part explaining another usage form of the cutting machine of FIG. Schematic diagram illustrating the cutting phenomenon in a conventional cutting machine

Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, this resin sheet cutting machine includes a rectangular plate-shaped base 1, a pair of rectangular frames 2 erected on the upper surfaces of both sides of the base 1, and both rectangular frames 2. A table 3 passed between the upper surfaces of the upper side portion, a flat plate-shaped elevating member 4 arranged above the table 3, pillar members 5 fixed on both sides of the elevating member 4, and an elevating member 4. The main part of the cutting machine main body is composed of a crank mechanism (elevating mechanism) 6 that raises and lowers both pillar members 5 integrally. Blade holders 7 and 8 extending in the left-right direction (left-right direction in FIG. 1) of the cutting machine main body are attached to the lower edge portion of the elevating member 4 and the upper surface of the table 3, and a strip plate is attached to the upper blade holder 7. The upper blade 9 in the shape of a strip and the lower blade 10 in the shape of a strip are held in the lower blade holder 8.

Then, the crank mechanism 6 is operated while the resin sheet S continuously extruded from the extruder (not shown) is passed between the upper blade 9 and the lower blade 10, and the upper blade 9 is moved to the blade holder 7. The resin sheet S is cut by lowering the elevating member 4 and both pillar members 5 integrally (see FIG. 7). This cutting machine targets hard resin sheets such as acrylic resin, which have smaller elongation and Izod strength values than polycarbonate.

Although not shown, the base 1 is held so as to be reciprocally movable in the seat flow direction, and is connected to the servomotor via a motion conversion mechanism that converts rotary motion into linear motion. When the cutting machine performs the cutting operation, it is driven by the servomotor to move to the downstream side of the sheet flow following the extrusion speed of the extruder, and return to the original position after the cutting is completed.

As shown in FIGS. 1 and 3, a long fixed holding member 11 extending in the left-right direction of the cutting machine main body facing the lower edge portion of the elevating member 4 is fixed to the upper surface of the table 3. A blade holder 8 (for the lower blade) for holding the lower blade 10 and a cotter 12 for adjusting the vertical position of the lower blade 10 are fitted into the rectangular groove 11a provided on the upper surface of the fixed holding member 11. There is. As a result, the upper blade 9 that is held up and down above the passing position of the resin sheet S and the lower blade 10 that is fixedly held below the passing position of the resin sheet S move their respective cutting edges in the vertical direction. They are arranged so as to face each other.

Here, the cotter 12 is incorporated at a position where it is vertically sandwiched between the fixed holding member 11 fixed to the table 3 of the cutting machine main body and the blade holder 8 for the lower blade. The upper surface of the cotter 12 and the lower surface of the blade holder 8 for the lower blade facing the cotter 12 are inclined surfaces that are inclined at the same angle with respect to the left-right direction of the cutting machine main body. As a result, when the cotter 12 is moved in the horizontal direction, the vertical position of the lower blade 10 can be adjusted integrally with the blade holder 8 for the lower blade.

Further, L-shaped side plates 13 are erected on both sides of the upper surface of the table 3, and guide plates 14 for guiding the pillar member 5 in the vertical direction are fixed to each of these side plates 13. There is. Each pillar member 5 penetrates the table 3 in the vicinity of the standing position of the side plate 13, and is connected to the crank mechanism 6 by a leg portion 5a provided on the lower end side thereof.

The crank mechanism 6 is rotated around a servomotor 15 installed on a base 1, a crank shaft 17 connected to the servomotor 15 by a belt 16, a crank shaft 17, and a leg portion 5a of each pillar member 5. It is composed of a connecting member 18 that is movably connected. Both ends of the crank shaft 17 are rotatably supported by a support member 19 provided on the lower surface side of the table 3. As a result, when the servomotor 15 is driven, each pillar member 5 connected to the crank shaft 17 is guided by the guide plate 14 to move up and down as the crank shaft 17 rotates, and each pillar member 5 is fixedly moved up and down. The member 4, the blade holder 7 attached to the elevating member 4, and the upper blade 9 held by the blade holder 7 are also integrally raised and lowered.

As shown in FIGS. 1 and 3, the elevating member 4 has a plurality of windows 4a opened at the lower portion, and a blade holder 7 (for the upper blade) that holds the upper blade 9 from the lower edge of each of the windows 4a. The mounting bolt 20 is screwed into. Each mounting bolt 20 has a size such that the head can be easily grasped by hand so that the blade holder 7 for the upper blade can be easily attached to and detached from the elevating member 4.

As shown in FIGS. 3 and 4, the blade holder 7 for the upper blade is a long member formed in a U-shaped cross section, and most of the upper blade 9 is inside the U-shaped cross section. Is inserted together with the strip-shaped push plate 21 in a downward posture. Then, the push plate 21 is pushed by the push bolt 22 screwed from the outer surface of the side wall on one side (downstream side), and the upper blade 9 is sandwiched between the push plate 21 and the side wall on the other side (upstream side). As a result, the upper blade 9 is held so as to be able to move up and down integrally with the blade holder 7 above the passing position of the resin sheet S.

Further, as shown in FIGS. 3 and 5, the blade holder 8 for the lower blade has slightly different dimensions from the blade holder 7 for the upper blade, but has the same basic structure, and passes through the resin sheet S. The lower blade 10 is fixedly held in an upward posture below the position.

A long elastic member 23 having a rectangular cross section made of a sponge is adhered to the lower surfaces of both side walls of the blade holder 7 for the upper blade and the upper surfaces of the both side walls of the blade holder 8 for the lower blade. The upper elastic member 23 is formed thicker than the protrusion height of the upper blade 9 from the side wall of the blade holder 7, and the lower elastic member 23 is formed thicker than the protrusion height of the lower blade 10 from the side wall of the blade holder 8. ing. As a result, in the natural state, neither the upper blade 9 nor the lower blade 10 protrudes from the elastic member 23, and an accident in which the operator cuts a finger or the like is less likely to occur. Further, the resin sheet S can be cut stably with the upper and lower elastic members 23 compressed and sandwiching the resin sheet S.

As shown in FIG. 6, the upper blade 9 and the lower blade 10 have a blade body 9a and 10a having a constant thickness, and a blade edge 9b and 10b having a triangular cross section formed on one side of the blade body 9a and 10a, respectively. As the material thereof, carbon tool steel, high speed steel, super hard alloy, stainless steel, ceramics and the like are used. The angles of the blade tips 9b and 10b of the upper blade 9 and the lower blade 10 are the same (about 15 to 30 degrees), but the blade bodies 9a and 10a are formed so that the upper blade 9 is thinner than the lower blade 10. There is. Specifically, the thickness dimension T1 of the blade body 9a of the upper blade 9 is in the range of 0.2 to 2.0 mm, and the thickness dimension T2 of the blade body 10a of the lower blade 10 is in the range of 0.5 to 3.0 mm. The ratio T1 / T2 of the two is set to be 1 / 1.5 to 1/4.

Further, at the mounting positions of the upper blade 9 and the lower blade 10, the variation in the spacing between the cutting edges 9b and 10b in the vertical direction is 0.2 mm or less, and the variation in the spacing between the cutting edges 9b and 10b in the sheet flow direction is 0.1 mm or less. It is adjusted to be.

Next, the cutting operation of this cutting machine will be described. Between this cutting machine and the extruder, although not shown, a roller conveyor that supports the lower surface of the resin sheet from the extruder to the front of the cutting machine, and a protective film is coated on the upper and lower surfaces of the resin sheet in the middle. A film covering device, a labeler that attaches a label to the upper surface of the resin sheet near the downstream end of the roller conveyor, and a take-up roll that takes the resin sheet from the downstream end of the roller conveyor and sends it to the cutting machine are installed.

That is, the resin sheet continuously extruded from the extruder flows to the downstream side while the lower surface is supported by the roller conveyor, the upper and lower surfaces are covered with the protective film by the film covering device, and the upper surface is labeled with the labeler. After being pasted, it is sent to the cutting machine by a take-up roll.

In the cutting machine, when the cutting position of the resin sheet S passed between the upper blade 9 and the lower blade 10 reaches a predetermined position, the base 1 starts to move to the downstream side following the extrusion speed of the extruder. Around that time, the column member 5, the elevating member 4, the blade holder 7, and the upper blade 9 start to descend integrally by the operation of the crank mechanism 6. Then, as shown in FIG. 7, after the elastic members 23 of the upper and lower blade holders 7 and 8 are compressed to sandwich the resin sheet S, when the upper blade 9 and the lower blade 10 are driven into the resin sheet S, the driving is performed. Brittle fracture starting from the position occurs 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 the upper blade 9 is formed thinner than the lower blade 10. Is also easy to be driven into the resin sheet S. 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 amount of driving of the upper blade 9 and the lower blade 10 into the resin sheet S is suppressed to a small size, which is schematically shown in FIG. As shown, the fracture surface extends substantially at right angles to the front and back surfaces of the resin sheet S from the respective driving positions of the upper blade 9 and the lower blade 10, and the fracture surfaces are continuous near the center in the thickness direction of the resin sheet S. Then, the resin sheet S is cut. Therefore, it is difficult for chips to be broken into powder and whiskers-like protrusions to be generated on the cut surface at the time of cutting, and a flat cut surface can be obtained.

Then, the cut resin sheet S is sent to the next process by a discharge conveyor (not shown) installed on the downstream side of the cutting machine. Further, in the cutting machine after the cutting operation, the base 1 moves to the upstream side and returns to the original position, and the pillar member 5, the elevating member 4, the blade holder 7 and the upper blade 9 are integrally raised to the original position. Return to position.

This resin sheet cutting machine has the above-mentioned configuration, and lowers the upper blade 9 in a state where the resin sheet S is passed between the upper blade 9 held so as to be able to move up and down and the lower blade 10 held fixedly. Since the upper blade 9 and the lower blade 10 are driven into the resin sheet S to cause brittle fracture and cut, the cutting can be performed in a short time without generating chips.

Moreover, the thickness dimension T1 of the blade body 9a of the upper blade 9 is made smaller than the thickness dimension T2 of the blade body 10a of the lower blade 10, so that the upper blade 9 can be more easily driven into the resin sheet S than the lower blade 10. Compared to the case where the blade and the lower blade have the same specifications, the difference in the driving amount between the upper blade 9 and the lower blade 10 due to the backlash of the crank mechanism 6 is smaller, and good cut surface quality can be ensured. can.

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 main body of the cutting machine, the upper blade 9 is the blade holder 7. The lower blade 10 can be replaced integrally with the blade holder 8. Since this replacement work can be performed in a short time without requiring skill, the efficiency of the entire resin sheet manufacturing work can be significantly improved as compared with the case where the upper blade and the lower blade are independently attached to and detached from the cutting machine main body.

Further, by moving the cotter 12 incorporated between the blade holder 8 for the lower blade and the fixed holding member 11 in the horizontal direction, the vertical position of the lower blade 10 can be adjusted integrally with the blade holder 8. Therefore, the amount of driving of the upper blade 9 and the lower blade 10 into the resin sheet S can be easily adjusted.

Further, when the resin sheet to be cut is changed to one made of polycarbonate or a resin having a physical property value such as elongation at the same level as that of polycarbonate, as shown in FIG. 9, for the lower blade 10 and the lower blade. By simply replacing the blade holder 8 with the blade receiving member 24 that receives the cutting edge of the upper blade 9, the blade holder 8 can be easily switched to the conventional single-edged cutting machine for use.

The resin sheet cutting machine of the present invention is not limited to the one that cuts the resin sheet continuously extruded from the extruder as in the embodiment, but a part of the resin sheet already formed to a certain size is batched. Of course, it can also be applied to those that are cut in a process. A cutting machine that performs batch processing cutting does not require a moving mechanism for the base.

1 Base 2 Rectangular frame 3 Table 4 Elevating member 5 Pillar member 6 Crank mechanism (elevating mechanism)
7, 8 Blade holder 9 Upper blade 9a Blade body 9b Blade tip 10 Lower blade 10a Blade body 10b Blade tip 11 Fixed holding member 12 Cotta 21 Push plate 22 Push bolt 23 Elastic member 24 Blade receiving member

Claims (4)

A strip-shaped upper blade that is held up and down above the passing position of the resin sheet to be cut, a strip-shaped lower blade that is fixedly held below the passing position of the resin sheet, and the above. The upper blade and the lower blade are provided with an elevating mechanism for raising and lowering the upper blade, and the upper blade and the lower blade are arranged so that the cutting edges formed on one side of each blade body face each other in the vertical direction. By lowering the upper blade while passing the resin sheet between the two and driving the upper and lower blades into the resin sheet, the brittleness starting from the driving position of the cutting edges of the upper and lower blades into the resin sheet. In a resin sheet cutting machine that causes breakage and cuts
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, and the ratio of the thickness dimension of the blade body of the upper blade to the lower blade is 1 / 1.5 to 1/4. A resin sheet cutting machine characterized by this. The first aspect of the present invention is characterized in that the upper blade and the lower blade are each held by a blade holder detachably attached to a cutting machine main body and can be replaced integrally with the blade holder. Resin sheet cutting machine. A cotter is incorporated in a position where the blade holder holding the lower blade and the cutting machine main body are sandwiched in the vertical direction, and the lower blade can be adjusted in the vertical direction by moving the cotter in the horizontal direction. The resin sheet cutting machine according to claim 2 , wherein the resin sheet cutting machine is characterized by the above. The resin sheet cutting machine according to claim 2 , wherein the blade holder that holds the lower blade can be replaced with a blade receiving member that receives the cutting edge of the upper blade.

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