JPH07214659A - Method and apparatus for bending molding of thermoplastic synthetic resin panel - Google Patents

Abstract

PURPOSE:To enhance the production efficiency and efficiently produce a homogenous synthetic resin partition panel of high quality at a low cost. CONSTITUTION:A plurality of thermoplastic synthetic resin panels P are picked up one at a time to be successively transferred to a feed passage 2 and the feed means of the feed passage is intermittently driven at the same time in synchronous relation to the transfer of the synthetic resin panels P and, during the temporary stop of the synthetic resin panels P on the feed passage, each of the synthetic resin panels P is intermittently heated from the rear surface thereof by a linear heating means 41 extended along the feed passage. The synthetic resin panel P reaching bending temp. is successively bent at a specific angle along a bending line by a bending means 4 to be cooled and fixed while the bent and fixed synthetic resin panel P is successively discharged to the outside in the same posture by a discharge chute 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous bending method for bending a plurality of thermoplastic synthetic resin plates sequentially along a straight line at a right angle, and a bending forming apparatus therefor.

[0002]

2. Description of the Related Art In display shelves and the like of products, partition plates made of synthetic resin such as vinyl chloride or acrylic resin are often used to sort various products by type. The basic structure consists of a plate material with an L-shaped cross section that is made by bending a rectangular synthetic resin plate at a right angle from a predetermined part. When using it, one bending part is placed on the display shelf and the other bending part is used. The same type of product is displayed between the adjacent partition plates with the section standing upright. Under the present circumstances, such partition plates are manufactured one by one using a special bending jig.

[0003]

By the way, if the partition plate is damaged even a little, the appearance of the product is deteriorated. Therefore, the partition plate of the entire sales floor is often replaced with a new one. In particular, a partition plate made of an acrylic plate is more expensive than a partition plate made of vinyl chloride, but has excellent physical properties (heat resistance, environment resistance, strength, etc.), high transparency, and excellent appearance. Therefore, it is often used in the sales floor of fresh foods, high-grade sundries, precious metals, etc., and its finish may affect the evaluation of products.

However, in the above-mentioned manual production, the amount that one worker can produce per day is 2000 to 300.
Since it is only 0, the production efficiency is low and the cost is high, and high precision production cannot be expected without increasing the cost.

The present invention has been made to solve the above problems, and an object thereof is to improve the production efficiency and to efficiently form a uniform and high-quality partition plate at a low cost and a molding apparatus. To develop.

[0006]

Means for Solving the Problems The above-mentioned problems are solved by bending a plurality of thermoplastic synthetic resin plates of the present invention, which are sequentially fed while being heated along a folding curve while being sequentially supplied, and discharged. In the molding method, one by one is picked up from a plurality of thermoplastic synthetic resin plates and sequentially placed on a feeding path of the synthetic resin plate, and the conveying means of the feeding path is the synthetic resin plate. Of the synthetic resin plate is driven intermittently in synchronization with the transfer of the synthetic resin plate, and a linear heating means extending in the feeding path during the feeding of the synthetic resin plate along the predetermined folding curve. Is heated from the lower surface in multiple stages, the synthetic resin plate that has reached the bending temperature is sequentially bent and fixed at a predetermined angle along the folding curve by the bending means, and the bent synthetic resin plate is sequentially Including discharging to the outside of the machine by the discharging chute It is eliminated by folding the molding method of a thermoplastic synthetic resin sheet characterized by comprising.

The present invention is particularly suitable for bending of an acrylic resin plate, and guides the side surface of the synthetic resin plate in a straight line during feeding of the synthetic resin plate and sandwiches the heating means. While pressing the upper surface, the heating means is operated during intermittent driving of the conveying means. Further, preferably, the bending means temporarily bends the synthetic resin plate at a predetermined angle or more, then returns it to a predetermined bending angle and cools and fixes it.

Further, the above object is to provide a bending forming apparatus for a thermoplastic synthetic resin plate according to the present invention, in which a plurality of thermoplastic synthetic resin plates are sequentially supplied while being heated along a bending curve and mechanically sequentially bent and discharged. And a synthetic resin plate transfer means for picking up one by one from a plurality of laminated thermoplastic synthetic resin plates and sequentially transferring them to a linear synthetic resin plate feeding path, and the transfer means. A heating section having a transfer section having a transfer section for intermittently positively feeding the transferred thermoplastic synthetic resin plate along the supply path and a linear heating section extending in the supply section. Section, heating operation means for intermittently operating the heating means, and a thermoplastic synthetic resin plate which is installed at the downstream end of the feeding path and is fed, is bent at right angles in sequence along the heating wire. A bend forming part having a bend / cooling means for fixing; A thermoplastic synthetic resin plate bending and forming apparatus is also provided, which is equipped with a discharge chute that receives a thermoplastic synthetic resin plate bent by a bending / cooling means in a predetermined posture and discharges it outside the machine in the same posture. To be done.

Preferably, the transfer section is controlled so as to be stopped when the thermoplastic synthetic resin plate is transferred by the transfer means and to start driving after the transfer is completed, and the heating means is heated by the heat bar. It has a fluororesin film on its heating surface, the heating operation means is an elevating cylinder of the heat bar, and when driving the transportation means, it stands by below the synthetic resin plate and stops the transportation means. It is constructed so that it sometimes rises to a position where it abuts the lower surface of the synthetic resin plate.

Further, the bending and forming section has the same plane as a number of pairs of conveying rolls on the extension of the feeding path, and a plurality of pairs of synthetic resin plate mounting rolls are arranged in a row, and the heat bar of the heat bar. The folding means includes a bending means for rotating around an axis on the extension line, a rotating means for rotating the bending means at a predetermined bending angle, and a cooling means for fixing the bent form. The bending means has a plurality of bending arms arranged in a comb-like shape which is located below the folding curve of the synthetic resin plate and rotates about an axis parallel to the folding curve. The means is composed of a pipe material that connects the base ends of the bending arms to each other and is connected to an external compressor, and the pipe material has a large number of air outlet holes linearly arranged. The rotating means temporarily rotates the bending arm at a predetermined bending angle or more, and then returns the bending arm to the predetermined bending angle.

[0011]

The synthetic resin plates stacked in multiple stages by the transfer means are sequentially transferred from the upper stage to the resin plate feed path. The synthetic resin plate transferred to the feeding path is sequentially conveyed to the heating unit of the next stage until it leaves the portion where the next synthetic resin plate is transferred. When the synthetic resin plate reaches each heating section, the conveying means of the feeding path is temporarily stopped each time, and at the same time, the heating section operating means is activated,
For example, after raising the heat bar and heating the upper surface of the heat bar for a predetermined heating time on the synthetic resin plate in the heating portion of each step along the folding curve, the heat bar 26a descends.
Here, the transporting means is restarted, and the driving is continued until the synthetic resin plate reaches the heating section of the next stage.

At this time, at the same time, the synthetic resin plate also sequentially reaches the bent portions. When this is reached, the transport means is stopped. The drive timing at this time is synchronized with the start / stop of the conveying means. When the synthetic resin plate reaches the bent portion, for example, the bending means including a bending arm starts to rotate from the horizontal state to the substantially vertical state around the cooling pipe material. This rotation is slightly larger than a predetermined set angle, and the synthetic resin plate is once bent over the set curve along the folding curve.
This bending angle is usually in the range of the set angle + (5-10) °.

This is because when a thermoplastic synthetic resin is heated under normal heating conditions, it is usual that a few percent of the elastic portion remains, so that elastic recovery after molding or internal distortion as distortion. This is to utilize the characteristics that remain and to ensure an accurate bending angle. That is, for example, 90
In order to maintain the shape of the bent product that is bent at a degree of 90 °, an angle that can return to the original shape (about +5 to +1 from 90 °)
Bend excessively to about 0 °. At this time, the heating state of the portion of the synthetic resin plate along the folding curve is in a state where the above-mentioned return occurs. Therefore, when the bending force of the synthetic resin plate is released, it tends to return to 90 ° or less. When this restoration is supported at a position of 90 ° so as to stop the restoration and forced cooling is performed, a synthetic resin plate accurately bent at a right angle can be molded.

On the other hand, when the bending arm is driven by an electric motor to ensure high speed, it is difficult to stop the electric motor suddenly at high speed. When the stop timing is set according to the bending angle, it is almost impossible to stop the electric motor accurately at the same angle, but it is possible to allow some overrun when the return of the resin plate is considered. . However, it is extremely difficult to return the overrun and stop the rotation at an exact 90 ° rotational position by just controlling the electric motor. In the present invention, the bending arm is rotated in the opposite direction immediately after the synthetic resin plate is once bent at 90 ° or more. During this time, once 90 °
The synthetic resin plate P bent as described above is left to the behavior of returning to the original shape. Before the movement, the position of the bending arm 62a is fixed at 90 ° to return the synthetic resin plate P to the original shape. It is an accurate stop at 90 °.

Therefore, since it is necessary to accurately perform the reverse rotation stop operation by the electric motor, a method of physically forcibly stopping the bending arm at a predetermined angle is adopted to absorb the stop error during the reverse rotation stop. Performs highly accurate positioning. In the present invention, for example, a method is adopted in which the striker is actuated at the same time when the reverse rotation of the electric motor is stopped, and the striker is engaged with a part of the bending arm actuating member for positioning. In this case, if the tip of the striker is formed in a conical shape, even if there is a slight deviation from the engagement portion, the engagement portion is forcibly engaged with the engagement portion for reliable positioning. In this way, a uniform bending angle is obtained.

Thus, when the synthetic resin plate is accurately bent at a predetermined angle, cooling air is blown out from the cooling pipe material to positively cool the back side of the bent portion of the synthetic resin plate to form a bent shape. Fix it. When this cooling is completed, the folding means reversely returns to the original position and returns, and at the same time, the conveying means is driven,
The synthetic resin plate for which the bending has been completed is transferred to the discharge chute of the next stage.

[0017]

The present invention will be described in detail below with reference to illustrated embodiments. FIG. 1 is a front view showing a configuration example of an entire apparatus for producing a thermoplastic synthetic resin plate according to the present invention, and FIG. 2 is a plan view of the apparatus. The bending apparatus for a thermoplastic synthetic resin plate according to the present invention heats linearly and stepwise along a folding curve while sequentially feeding a plurality of the same synthetic resin plates on a linear feeding path, and at the same temperature. When it reaches the point, it is mechanically sequentially bent along the same bending curve and continuously discharged out of the machine.

Therefore, according to the above-mentioned embodiment, the synthetic resin is picked up one by one from the plurality of laminated thermoplastic synthetic resin plates P and sequentially transferred to a predetermined position of the linear synthetic resin plate feeding path 2. The plate transfer section 1, the transfer means 3 for intermittently and positively transferring the thermoplastic synthetic resin plate P transferred by the transfer section 1 along the feeding path 2, and the feeding path 2 are provided. A linear heating portion 4 that is extended and that linearly heats the synthetic resin plate P along a bending curve; and a heating operation means 5 that intermittently operates the heating means 41 of the heating portion 4, A bending molding portion 6 installed at the downstream end of the feeding path 2 for sequentially bending the conveyed thermoplastic synthetic resin plate P at a right angle along a folding curve, and folding by the folding molding portion 6. Receiving the bent thermoplastic synthetic resin plate P in a predetermined posture, while keeping the same posture And a discharge chute 7 is discharged to the outside.

FIG. 3 shows the main part of the transfer section 1, and the transfer section 1 picks up a plurality of laminated thermoplastic synthetic resin plates P one by one from the top at predetermined time intervals. The transfer means is provided for sequentially transferring to the entrance of the feeding path 2. As means for this transfer, for example, a cylinder is used to sequentially push out the side surfaces of the synthetic resin plate P in the horizontal direction, or two upper surfaces of the synthetic resin plate P are arranged in parallel in a pressure contact state. A method may be considered in which the uppermost synthetic resin plate P is fed horizontally while sequentially sliding the lowermost synthetic resin plate P by intermittently driving the roller while pressing it from above, but in this embodiment, FIG. As shown, the suction pad 11 is used to securely suck the uppermost synthetic resin plate P,
A method of transferring this to a predetermined portion at the entrance of the feeding path 2 is adopted.

That is, in FIG. 3, the suction pad 11 is made of, for example, synthetic rubber and has a stretchable structure.
It is supported at a right angle to the tip of the arm 12 via 1a, and the pipe material 11a is always urged in the extension direction by a spring 11b. A base end of the arm 12 is horizontally supported by an air cylinder 13 having a guide rod 12a, and the air cylinder 13 operates to move the suction pad 11 up and down by a predetermined distance. Further, the air cylinder 13 is provided with a rodless cylinder 14 arranged in parallel with a side portion of the feeding path 2 along the feeding path 2 so that the laminated portion 15 of the synthetic resin plate P and the feeding path 2 are provided. Reciprocates to and from the entrance. The pipe material 11a is connected to a vacuum pump (not shown), and the vacuum pump is operated when the synthetic resin plate P is adsorbed, and the outside air is introduced when the synthetic resin plate P is detached.

In FIGS. 1 and 2, the stacking portion 15 of the synthetic resin plate P is supported by a loading plate 15a which can be lifted and lowered by an electric motor 15b, and the electric motor 15b is a preset uppermost synthetic resin plate P. It stops upon receiving a signal from a sensor (not shown) such as a photoelectric sensor installed at the arrival position, and restarts after a predetermined time has elapsed. That is, the electric motor 15b operates while the uppermost synthetic resin plate P is adsorbed by the adsorption pad 11 and the synthetic resin plate P is transferred to a predetermined portion at the entrance of the feeding path 2. Then, the next synthetic resin plate P is raised to the reaching position.

Further, in this embodiment, in order to prevent the two sheets from being lifted at the same time due to the influence of the suction force of the suction pad 11 and the static electricity of the synthetic resin plate P, the front side of the synthetic resin plate P in the conveying direction is prevented. A stopper (not shown) made of an elastic material is attached to a portion of the frame (not shown) corresponding to the front end surface of the lower synthetic resin plate P.

Although it was considered to use a conveyor belt as the feeding path 2 for the synthetic resin plate P, it is difficult to convey a large number of synthetic resin plates P in parallel on the same plane by the conveyor belt. Therefore, a guide plate that separately mounts the synthetic resin plate P and guides it in the horizontal plane is required, and there is a risk that sliding contact marks may remain on the synthetic resin plate P. Therefore, in the present embodiment, as the conveying means 3 for the synthetic resin plate P, a large number of conveying roll pairs 31 as shown in FIGS. A chain that transmits power and a timing belt 33 are adopted.
That is, as shown in FIG. 2, a large number of pairs of conveying roll pairs 31 arranged at predetermined intervals in the width direction are installed on the conveying path. A large number of these pairs of transport rolls 31 are driven by a drive motor 32 so that a chain or timing belt 33
Driven synchronously via.

The feeding path 2 has a heating portion 4 in a portion extending from a predetermined position of its inlet to a predetermined length, and a bend forming portion 6 in a portion adjacent to the downstream side of the heating portion 4. I have it. The heating unit 4 is arranged in a predetermined gap formed between the pair of transport rolls 31 and extends over the entire length of the heating unit 4, and a temperature control device (not shown) for the heat bar 41. Consists of. In the present embodiment, the length of the heating section 4 is set to a length sufficient for arranging 5 sheets at the same time if the partition plate is of a size that meets the usual specifications. Specifically, the heat bar 41 has a length of 2 m, and a long bar member having a width of 12 mm is used, and the upper surface of the heat bar 41 is the same when the synthetic resin plates P which are intermittently conveyed are stopped. The lower surface of the synthetic resin plate P is contacted and heated directly. Therefore, in the present embodiment, the heat bar 41 is supported by a plurality of air cylinders (not shown), the heat bar 41 is lowered below the upper surface of the pair of transport rolls 31 when the synthetic resin plate P is transported, and only during heating. An air cylinder (not shown) is operated to make a bid up to the same height as the upper surface of the transport roll pair 31. This operation timing is detected by a limit switch (not shown) installed corresponding to the arrival position of the conveyed synthetic resin plate P, and at the same time the drive of the drive motor 32 is stopped.
The air cylinder is operated. Since it is difficult to maintain the linearity of the heat bar 41, the heat bar 41 is fixedly held by a linear metal frame (not shown) having an L-shaped cross section through a heat insulating pedestal such as Bakelite. Further, a heat-resistant fluororesin tape (not shown) is attached to the contact surface of the heat bar 41 with the synthetic resin plate P to protect the heating surface of the synthetic resin plate P and perform uniform heating. I try to get an elegant molded product.

The synthetic resin plate P transferred to a predetermined position on the feeding path 2 by the suction pad 11 moves forward while repeatedly stopping and carrying by a number of carrying roll pairs 31 of the carrying means 3. The heat bar 41 intermittently heats the same curve. At this time, if there is nothing to regulate the side surface of the synthetic resin plate P, a large number of pairs of transport rolls 31
There is no guarantee that it will move linearly on the upper surface of the. Therefore,
In this embodiment, the positional relationship between the heat bar 41 and the synthetic resin plate P is maintained, and in order to heat only the same portion of the synthetic resin plate P, linear heating portion guides parallel to each other on the left and right side portions of the feeding path 2 are provided. 21 is provided.

In order to ensure the linearity of the guide 21,
As shown in FIG. 4, it is made of a mold material having an L-shaped cross section, and is longitudinally arranged on a support frame member 23 erected between the pillar portions 22 standing upright on the left and right sides of the feeding path 2 via a pair of left and right brackets 24. Supported at multiple points in the direction. Therefore, a plurality of vertically long screw holes 21a are formed at predetermined intervals in the longitudinal direction of the guide 21. The pillar portion 22 is screwed into the base portion 22d, and the pillar body 22a is slidably fitted to the pillar body 22a, and the frame end has a substantially T-shaped appearance for supporting the left and right ends of the support frame member 23. The support member 22b and the spring 22c for urging the frame end support member 22b downward are provided. The upper and lower ends of the pillar main body 22a are threaded, and a flange 22a-1 is formed adjacent to the upper end of the lower end screw portion 22a '. Also, a double nut 22a-3 is attached to the upper screw portion 22a-2 of the column main body 22a,
The double nut 22a-3 and the frame end support member 22
The spring 22c is interposed between the spring 22c and b. Frame end support portion 22 of the frame end support member 22b
The b'has a fitting hole into which the left and right ends of the support frame member 23 are fitted.

On the other hand, the bracket 24 comprises a fitting portion 24a slidably fitted to the supporting frame member 23 and a guide supporting portion 24b projecting downward from the fitting portion 24a. The first screw hole 24 is provided on the upper surface of 24a.
A'is formed so as to penetrate to the inside, and a second screw hole 24b 'is formed in the guide support portion 23b. The guide 21 is supported by the bracket 24 by screwing a bolt 25 into the second screw hole 24b 'and the screw hole 21a of the guide 21. Then, a bolt (not shown) is screwed into the first screw hole 24a 'formed in the fitting portion 24a of the bracket 24, so that the bracket 24 is fixed to a desired position of the support frame member 23.

With the above structure, the lower limit position of the guide 21 is set by adjusting the screwing amount of the column main body 22a with respect to the base portion 22d, and the downward elastic force of the frame member 23 is set to the position of the double nut 22a-3. It is adjusted by adjusting. The distance between the pair of left and right guides 21 is set by loosening the bolts screwed into the first screw holes 24a 'of the fitting portion 24a and sliding the bracket 24 along the support frame member 23. Adjusted to. In this way, by attaching the left and right guides 21, it is possible to prevent meandering during the transportation of the synthetic resin plate P, so that the heating width is not widened and the heating efficiency is not reduced.

By the way, generally, when a thermoplastic synthetic resin plate is linearly heated from one side, a difference in thermal expansion occurs between the front and back sides, and a warp protruding toward the heating side occurs. This phenomenon is particularly severe when the acrylic plate is heated by a bar heater. In the case of contact heating with the heat bar 41 as described above, both sides of the heating bar are warped to cause floating, and the posture during conveyance is not constant, and uneven heating occurs. Therefore, it is necessary to forcibly suppress the warp during contact heating and always bring the heat bar 41 into close contact with the synthetic resin plate P evenly. In the present invention, since the synthetic resin plate P is intermittently heated while being conveyed, the warp is suppressed by the rollers.

FIG. 4 shows a warp suppressing mechanism according to this embodiment. According to FIG. 4, the warp suppressing member 26 is supported by a supporting mechanism similar to that of the guide 21.
That is, the warp suppressing member 26 is composed of a long plate body 26a having an L-shaped cross section and a large number of rollers 26b arranged in the longitudinal direction of the plate body 26a at predetermined intervals. Reference numeral 26 also shares the support frame member 23, and is fixed to the bracket 24 having the above-mentioned structure using the bolt 25. Therefore, the warp suppressing member 26 is also attached to the guide 2 described above.
As in No. 1, the lower limit position is set by adjusting the screwing amount of the column main body 22a with respect to the base portion 22d, and the downward elastic force is also adjusted by adjusting the position of the double nut 22a-3. Further, in order to correspond to the size of the bent molded product, the interval between the pair of left and right warp suppressing members 26 sandwiching the heat bar 41 is set to the first screw hole 2 of the fitting portion 24a.
Loosen the bolts screwed into 4a ',
4 is slid along the support frame member 23 to adjust the distance to a desired value.

As described above, the warp suppressing member 26 can be adjusted in its lower limit position, that is, the height for pressing the synthetic resin plate P, and its downward elasticity can be adjusted. The distance between the lower limit position and the upper surface of the transport roll pair 31 is
This has a great influence on the bending forming by the device of the present invention. That is, the distance between the upper surface of the pair of transport rolls 31 and the lower surface of the roller 26a of the warp suppressing member 26 (hereinafter, referred to as clearance) may be set to be substantially equal to the thickness of the synthetic resin plate P to be molded. Results are obtained. When the thickness is more than the plate thickness, not only the pressure is small but also the heating efficiency is lowered.
According to the actual measurement, when the clearance is set to be equal to or larger than the plate thickness, there is a temperature decrease of 4 to 5 ° C. on the back surface side of the contact surface of the heat bar 41. On the other hand, when the clearance is set to be equal to or less than the plate thickness, the temperature decrease is reduced, but the heater traces are slightly increased. The rollers 26a are designed to elastically press the synthetic resin plate P by the springs 22c of the above-mentioned supporting column 22, and if the clearance is set smaller than the thickness of the synthetic resin plate P, the pressing force increases.

Table 1 shows the influence when the clearance is changed by using the synthetic resin plate P made of 2 mm acrylic resin. The molding conditions were that the heat bar temperature was 180 ° C., and one molding was performed every 10 seconds.

[0033]

[Table 1]

It can be seen from Table 1 that good results can be obtained when the clearance is set to the thickness of the synthetic resin plate P used. Further, it is also possible to reduce the temperature difference between the pressing portions of the left and right rollers 26a that sandwich the heat bar 41.
This is a condition for obtaining favorable results.

It has also been found that the distance between the roller 26a and the heat bar 41 also has a great influence on the bending molding of the present invention. Table 2 shows the influence when the distance is changed.

From this table, it can be understood that it is preferable that the position of the roller 26a be as close to the heat bar 41 as possible within a range where it does not interfere with the heat bar 41. The molding conditions were a plate thickness of 2 mm, a clearance of 2 mm and a heater of 180 ° C., and one was molded in 10 seconds. However, in Table 2, the center means the installation position of the heat bar 41.

[0037]

[Table 2]

From Table 2, the position of the roller 26a should be as close to the heat bar as possible, and 10 mm from the heater for safety.
It can be said that the shifted position is appropriate.

Next, regarding the influence of the temperature of the heat bar 41 and the heating time, the temperature of the heat bar 41 is not particularly limited as long as it is equal to or higher than the melting temperature Tg of the synthetic resin plate P. However, since the temperature of the heating resin is limited, the heater temperature and the heating time must be determined so as to fall within the range. Moreover, it is unsuitable above the combustion temperature of the protective paper attached to the synthetic resin plate. For example, in the case of a plate material made of acrylic resin, the melting temperature TG is about 100 ° C., so that the heater temperature is 120 to 240 ° C., and the resin temperature is also appropriately 120 ° C. to 240 ° C., preferably the heater temperature. Is 170 ° C to 210 ° C.

When an acrylic resin plate is heated by contact with the heat bar 41, the heating time must be determined by the heater temperature and the plate thickness. Further, since the present invention heats intermittently in a batch system, the total heating time is divided into batches,
In consideration of the temperature drop during movement, it is necessary to add a few seconds to the cost. For example, when the plate thickness is 2 mm and the heater temperature is 180 ° C., molding can be performed in 30 seconds. In the case of the batch system using five-step heating, 30/5 = 6 seconds, so that the diameter is 40 seconds and requires 8 seconds.

The results of changing the heater temperature under the same conditions (angle, heating, cooling time, etc.) are shown below.

Plate thickness 2 mm, heating 8 seconds × 5, cooling 5 seconds (1
(1 molding in 0 seconds)

[0043]

[Table 3]

The reason why the present invention employs batch type heating as described above is as follows. As already mentioned,
Although the partition plate made of acrylic resin is more expensive than that made of vinyl chloride, its selling points are its excellent physical properties (heat resistance, environmental resistance, strength, etc.) and its elegant appearance. Then, in order to maintain an elegant appearance, a protective paper is adhered to the plate material before processing, and the protective paper is adhered to the heat bar 41 for heating even during processing. However, a trace of the heater remains on the heating part. Further, when folded, the protective paper of the heating portion is torn, but a part of the protective paper may adhere and become difficult to peel off. On the other hand, heat bar 4
The efficiency is improved by increasing the length of 1 and heating continuously. However, in the contact movement type that moves while contacting the heater, defects on the protective paper are likely to occur. This is because the heat bar 41 is pressed against the heating portion and the sliding contact state is maintained. On the other hand, it is necessary to suppress the plate in order to reduce warpage of the synthetic resin plate P and uneven heating.
In addition to this, the fluororesin tape attached to the heating surface of the heat bar 41 is easily worn.

Therefore, although the heating efficiency is somewhat inferior, a multi-step batch type heating is adopted because an appearance and stability similar to hand processing can be realized. In batch heating, it is easy to adapt the time required for bending and cooling, and it is easy to set various conditions. It is necessary to set the bending cooling time not to be longer than the one batch heating time, and if it does not match, the subsequent synthetic resin plate P must wait for a predetermined time after heating. In the meantime, the subsequent synthetic resin plate P is cooled. This is summarized in Table 4
become that way.

[0046]

[Table 4]

At the downstream end of the heating section 4 described above, a thermoplastic synthetic resin plate P heated to a predetermined bending temperature and conveyed is bent at right angles in sequence along a folding curve. The bending part 6 forming an important component is continuously installed. The bending portion 6 forms the same plane as a large number of pairs of conveying rolls 31 on the extension of the feeding path 2 as shown in FIG.
, A plurality of pairs of synthetic resin plate mounting rolls 61 are arranged in a row, a bending means 62 that rotates about an axis line on the extension line of the heat bar 41, and the bending means 62 is approximately 90 °.
The rotating means 63 for rotating and the cooling means 64 for fixing the bent shape are provided.

The synthetic resin plate mounting roll pair 61 has substantially the same structure as that of the transport roll pair 31, and in the example shown in FIGS. 1 and 2, eight sets are divided into right and left on the extension line of the heat bar 41. It consists of a pair 61 of rolls. Among these synthetic resin plate mounting roll pairs 61, the gaps between the six adjacent roll pairs 61 sandwiched by two and one roll pairs 61 arranged before and after in the transport direction of the synthetic resin plate P are the same. The folding means 62 is rotatably installed around a straight line connecting the gaps.
Therefore, the bending means 62 has a comb shape as a whole as shown in FIG. 8, and the five comb-teeth portions thereof are the bending arms 62.
and a portion connecting the base ends of the bending arms 62a is a pipe member 64a forming a part of the cooling means 64.

According to the embodiment shown in FIGS. 1 and 2, the edge support guide 68 for positioning and supporting one side edge of the synthetic resin plate P has the side opposite to the turning side of the folding means 62. Of the synthetic resin plate is abutted and guided, and is extended to a portion supporting the same side surface. The edge support guide supports one side edge of the synthetic resin plate P from the side surface and prevents the synthetic resin plate P from being laterally displaced when the synthetic resin plate P is bent. The synthetic resin plate P is supported by the support guide 68.
The placement form on the synthetic resin plate placement roll pair 61 is stabilized.

Furthermore, according to the embodiment, in addition to the edge support guide 68, a bent portion plate pressing member 69 extending inward along the bent valley line of the synthetic resin plate P is provided. .
The bent plate pressing member 69 has a structure similar to that of the warp suppressing member 26 of the heating unit 4, and the plate body 69a.
A large number of rollers 69b are arranged in a straight line at predetermined intervals in the longitudinal direction. The bent plate pressing member 69 is
When the synthetic resin plate P is bent, the synthetic resin plate P has a function of preventing the synthetic resin plate P from being lifted up from the synthetic resin plate mounting roll pair 61 along the bending curve.
Is pressed against the synthetic resin plate mounting roll pair 61 along the folding curve to improve the molding efficiency.

The bending arm 62a is made of a metal rod having a substantially T-shaped cross section with a rib on the back side as shown in FIG. This is for ensuring the strength of the arm 62a and the smoothness of the pressing surface, and for pressing a part of the back surface of the synthetic resin plate P with a predetermined area. by the way,
It was found that when the synthetic resin plate P was bent at the same time along the heated bending curve by the plurality of bending arms 62a described above, both ends of the bent molded product in the width direction were warped outward. Assuming that the bending arm 62a is adopted, it is impossible to make the width of the arm 62a larger than the gap between the adjacent roll pairs 61.
As a result of various studies to prevent the warp with a width equal to or less than the gap, as a result, the pressing surface of the bending arm 62a that presses both ends of the synthetic resin plate P is changed to another bending arm 62a.
It was found that a better result can be obtained by making it more protruding. In this embodiment, of the plurality of bending arms 62a having the same structure as described above, a spacer 62b made of a synthetic resin piece is integrally attached to a part of the pressing surface of the bending arm 62a located at the end. If the attachment position of the spacer 62b is close to the base end, the intended purpose is achieved.

On the other hand, the pipe member 64a connecting the bending arms 62a is formed with a large number of air outlet holes 64a 'for cooling the heating portion of the synthetic resin plate P from the lower surface on the same straight line. The end of the pipe material 64a is connected to a compressor (not shown) outside the machine via a rotary pipe joint or the like. By the way, when the air is directly applied to the molded product, the protective paper is peeled off.
b is fixed to a frame (not shown) along the lower side of the bent portion of the synthetic resin plate P, and air is blown directly onto the inner surface of the iron plate 64b, so that the inner surface forms an air flow along the protective paper, and the protective paper does not peel Air is applied to the bent portion at an angle.

FIG. 5 shows a model of an example of the rotating means 63 of the folding arm 62a applied to this embodiment. The rotating means 63 is a bracket 64 fixed to a frame (not shown). The drive unit main body 63a is pivotally supported by the drive unit main body 63a, and an electric motor (not shown) is built in the drive unit main body 63a. An output shaft end of the electric motor is projected from an outer surface of the drive unit main body 63a, and a striker 66 described later is provided at the output shaft end.
The second operation metal fitting 63b is fixed. The rotation actuating rod 65 of the bending arm 62a is vertically movably inserted into the drive unit body 63a. Same operating rod 6
Reference numeral 5 is supported by the drive unit main body 63a by the electric motor and a power transmission mechanism such as a rack and a pinion, and moves up and down. The upper end of the actuating rod 65 has a pivotal support portion 6 protruding from the rear surface of the base end portion of the bending arm 62a.
2c, and a first actuating metal fitting 65a for actuating the first and second limit switches 67a, 67b for forward / reverse / stop of the electric motor is attached to the lower end of the actuating rod 65. There is.

The first and second limit switches 67
As shown in an enlarged view in FIG. 10, a and 67b are fixed to the frame at a predetermined interval within the moving range of the first actuating fitting 65a. Further, a third limit switch 67c is fixed to a portion of the drive portion main body 63a corresponding to the second operating metal piece 63b. Further, the striker 66 is attached to the drive unit main body 63a substantially horizontally within the range of movement of the back surface of the first actuating metal fitting 65a. The striker 66 is made of a metal rod having a conical tip end, and its base end is attached to the rod end of the air cylinder 66a. The striker 66 repeats its operation at a predetermined time upon receiving a signal from the third limit switch 67c. . Then, a positioning hole 6 with which the tip of the striker 66 engages with a part of the back surface (right side in FIG. 10) of the first operation fitting 65a.
5a 'is formed.

In such a configuration, when the synthetic resin plate P is conveyed to the heating section of the next stage in the feeding path 2, a limit switch (not shown) is turned on and all the roll pairs 31 arranged in line in the feeding path 2
Is stopped, and at the same time, the air cylinder 42 is activated to raise the heat bar 41, and after heating the upper surface of the heat bar 41 for a predetermined time along the folding curve of the synthetic resin plate P of each stage,
The heating bar (not shown) runs out and the heat bar 41 descends. Here, the drive motor 32 is restarted and the drive of the pair of transport rolls 31 is continued until the signal from the limit switch is sent.

At this time, the synthetic resin plate mounting roll pair 61 is driven by a separate drive motor independent of the drive motor 32, but a limit switch is also installed in the bending portion 6 individually, and When the resin plate P reaches the predetermined mounting portion of the pair of synthetic resin plate mounting rolls 61, the drive motor 32 is stopped for the same period of time. The drive timing at this time is to start the electric motor 32,
In sync with the stop.

When the synthetic resin plate mounting roll pair 61 is stopped, the operation of the bending portion 6 is started. That is, when the first limit switch 67a operates and an electric motor (not shown) built in the drive unit main body 63a rotates to move the operating rod 65 upward, a plurality of pivotal members pivotally attached to the upper end of the operating rod 65 are provided. The bending arm 62a in the horizontal state is pushed by the pivotally supporting portion 62a 'and starts to rotate upward about the axis of the pipe material 64a. When the actuating rod 65 moves upward by a predetermined distance, the first actuating metal fitting 65a at the lower end moves to the second limit switch 67.
At the same time, the motor is stopped and the electric motor is stopped, and the electric motor is reversed. At this stop, the bending arm 62a is rotated from the horizontal state to an angle slightly exceeding 90 °, and the synthetic resin plate P is once bent at a right angle or more along the bending curve. This bending angle is usually in the range of 90 ° + (5-10) °.

As described above, in the present invention, the reason why the bending arm 62a is once rotated by 90 ° or more and the bending angle of the synthetic resin plate P is once bent at a right angle or more in the initial stage is as follows.
It is as follows. Usually, a thermoplastic resin is plastically deformed when heated to a predetermined temperature and external force is applied. However,
It is not easy to bring the entire resin into a completely thermoplastic state, and it is common for some of the elastic parts to remain depending on the heating conditions. Therefore, it may be elastically restored after molding, or may remain inside as strain. Also in the present invention, if the resin plate P is not sufficiently heated along the folding curve, it will elastically return to its original shape even if the resin plate P is bent exactly 90 °, and a right angle bent product is obtained. Can't get Therefore, in order to maintain the shape of a bent product bent at 90 °, a method of sufficiently cooling at the time of 90 ° and an excess of 90 ° in consideration of elastic return are considered. It is conceivable to employ either a method of bending and then fixing by cooling.

The present invention takes into consideration the above-mentioned characteristics of the synthetic resin and adopts a method of fixing the form by efficient cooling. Therefore, the limit angle (about +5 to ++ from 90 °) at which the original shape can be restored by the first bending operation as described above.
Bend excessively to about 10 °. At this time, the heating state of the portion of the synthetic resin plate P along the bending curve is in a state where the above-mentioned return occurs. Therefore, the synthetic resin plate P
When the bending force of is released, it tries to return to 90 ° or less. When this restoration is supported at a position of 90 ° so as to stop the restoration and forced cooling is performed, the synthetic resin plate P bent at a right angle can be formed.

The bending arm 62a is driven by an electric motor in order to ensure high speed, but it is difficult for the electric motor to stop immediately upon receiving a signal from the limit switch during high speed rotation. Therefore, as described above, the bending angle of the synthetic resin plate P by the bending arm 62a is set to 9
When it is set to 0 °, it is almost impossible to stop the electric motor accurately at the same angle, but when the return of the resin plate P is taken into consideration, some overrun can be expected, and the electric motor is stopped. High accuracy is not required for the position. However, it is very difficult to control the electric motor in order to return the overrun to 90 ° accurately. In the present invention, a method is adopted in which the above-mentioned characteristics at the time of resin molding are utilized, and at the same time, a stop position by the electric motor is secured to improve bending accuracy.

That is, according to the present invention, the drive of the electric motor is stopped and a reverse signal is given at the same time when a predetermined time has elapsed after the second limit switch 67b was actuated to reverse the electric motor. As a result, the bending arm 62 is provided immediately after the synthetic resin plate P is once bent at 90 ° or more.
Rotate a in the opposite direction. In the meantime, the synthetic resin plate P once bent at 90 ° or more is left to return to its original shape.
Before the movement is made, the position of the bending arm 62a is set to 90.
It is fixed at 90 °, and the return of the synthetic resin plate P to the original shape is accurately stopped at 90 °.

Therefore, it is necessary to accurately perform the reverse rotation stop operation by the electric motor, but it is difficult to realize it as described above. Therefore, in order to absorb the stop error at the time of the reverse rotation stop and to perform the highly accurate positioning, the method of physically forcibly stopping the bending arm 62a at a predetermined angle is considered to be reliable, and in the present invention, the electric drive is performed. When the reverse rotation of the motor is stopped, the third limit switch 67c is turned on by the second operating metal fitting 63b to operate the striker 66,
The front end of the striker 66 is attached to the lower end of the operating rod 65, and the positioning hole 65 of the first operating fitting 65a is attached.
The method of engaging with a'and positioning is adopted. In this case, even if the position of the positioning hole 65a 'is slightly displaced from the tip position of the striker 66, the striker 66 is
Since the tip of each is conical, the positioning hole 65
When engaging with a ', it is forcibly engaged with the hole 65a' to enable reliable positioning. In this way, a uniform bending angle is obtained.

Thus, when the synthetic resin plate P is accurately bent at 90 °, a compressor (not shown) is actuated and cooling air is blown out from the air blowing hole 64a 'of the pipe member 64a, and the iron plate 64b having an arc-shaped cross section. The rear surface side of the bent portion of the synthetic resin plate P is positively cooled for a predetermined time through the arc surface to fix the bent shape. When this cooling is finished,
The bending arm 62a reversely returns to the original position and returns, and at the same time, the synthetic resin plate mounting roll pair 61 is driven to transfer the synthetic resin plate P, which has been bent and formed, to the discharge chute 7 of the next stage.

As shown in FIGS. 1 and 2, the discharge chute 7 comprises a cage-shaped container having a continuous inlet at the outlet end of the pair of synthetic resin plate mounting rolls 61, and the bottom of the chute 7 is folded. When the sensor detects that the entire curved molded product is reliably placed, the opening / closing member 71 made of stainless steel automatically opens to one side. According to this embodiment, the width of the discharge chute 7 for accommodating the product can be adjusted by sliding in the width direction (vertical direction in FIG. 2) to correspond to the bending width of the synthetic resin plate. When the synthetic resin plate P bent at a right angle as shown in FIG. 11 is transferred to the opening / closing member 71 of the discharge chute 7, the opening / closing member 71 is provided on the bent portion side of the plate P. It is configured to open downward from one side. With such a one-sided opening, the synthetic resin plate P always falls in the posture shown in FIG. 7B while sliding the opening / closing member 71. The falling synthetic resin plates P are sequentially stacked and accommodated in the trolley 8 that stands by in the lower position in the falling posture. Therefore, the loading surface of the truck 8 has a substantially inverted V-shaped cross section.

[0065]

As is apparent from the above description, according to the present invention, for example, a synthetic resin partition plate having an L-shaped cross section can be bent automatically and efficiently without requiring manpower. Not only is this possible and production efficiency is improved, but high-quality products can be manufactured continuously.
In particular, in the present invention, the synthetic resin plate is intermittently conveyed along the heating line and is heated in multiple stages, and at the bent portion, once bent over a predetermined angle, the elastic deformation characteristic is used up to a set angle. Since it is returned and then accurately positioned at that angle and then cooled and fixed, not only is it possible to ensure the required heating time and link the heating part and the bending part, but it is also possible to achieve extremely high bending accuracy. A highly homogeneous product can be stably obtained.

[Brief description of drawings]

FIG. 1 is a front view showing the overall configuration of a bending apparatus of the present invention.

FIG. 2 is a plan view of the device.

FIG. 3 is a partial front view showing a main part of a transfer means for a synthetic resin plate in the same apparatus.

FIG. 4 is a cross-sectional view showing a substantially half of a feeding unit in the same device.

FIG. 5 is a side view showing a schematic configuration example of a bent portion of the device.

FIG. 6 is a side view showing an operation example when a bending operation is performed by the bending portion.

FIG. 7 is a side view showing an example of an operation at the time of fixing the bending by the bending portion.

FIG. 8 is an overall configuration diagram showing an example of bending means of the same bending portion.

FIG. 9 is a cross-sectional view showing a shape example of a bending arm as the bending means.

FIG. 10 is an explanatory diagram when the striker is operating when the bending is fixed by the bending portion.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 (Thermoplastic) synthetic resin plate transfer means 11 Suction pad 11a Pipe material 11b Spring 12 Arm 12a Guide rod 13 Air cylinder 14 Rodless cylinder 15 Laminated portion 15a Loading plate 15b Electric motor 2 Synthetic resin plate feeding path 21 Heating unit Guide 21a Screw hole 22 Strut part 22a Strut body 22a-1 Flange 22a-2 Upper screw part 22a-3 Double nut 22b Frame end support member 22b 'Frame end support part 22c Spring 23 Frame material 24 Bracket 24a Fitting part 24a' No. 1 Screw Hole 24b Guide Supporting Part 24b 'Second Screw Hole 25 Bolt 26 Warp Suppression Member 26a Plate Material Body 3 Synthetic Resin Plate Conveying Means 31 Conveying Roll Pair 32 Drive Motor 33 (Chain or Timing Belt) Transmission Means 4 Synthetic Resin Plate Heating Part 4 Heat bar 42 Air cylinder 5 Heating part operating means 6 Bending forming part 61 Synthetic resin plate mounting roll pair 62a Bending arm 62b Spacer 62c Pivoting part 63 Rotating means 63a Driving part body 63b Second operating metal fitting 64 Cooling means 64a Pipe Material 64a 'Air blowout hole 64b Iron plate 65 Rotating operating rod 65a First operating metal fitting 66 Striker 66a Air cylinder 67a, 67b, 67c First to third limit switch 68 Edge support guide 69 Bent plate retainer 69a Plate material Main body 69b Roll 7 Discharge chute 71 Opening / closing member 8 Cart P Synthetic resin plate

Claims (6)

[Claims] 1. A plurality of thermoplastic synthetic resin plates are sequentially supplied while being heated along a folding curve and being sequentially bent,
A method for bending a thermoplastic synthetic resin plate to be ejected, which comprises picking up one by one from a plurality of thermoplastic synthetic resin plates and sequentially transferring them to a feeding path of the synthetic resin plate, Predetermined by intermittently driving the transporting means of the feeding path in synchronization with the transfer of the synthetic resin plate, and by linear heating means extending in the feeding path during feeding of the synthetic resin plate. The synthetic resin plate is heated from the lower surface in multiple steps along the folding curve, and the synthetic resin plate that has reached the bending temperature is bent and fixed at a predetermined angle along the folding curve by the bending means. And a bent synthetic resin plate are sequentially discharged to the outside of the machine by a discharge chute, and a method for bending a thermoplastic synthetic resin plate. 2. The bending molding method according to claim 1, wherein the synthetic resin plate is an acrylic resin plate. 3. The bending method according to claim 1, wherein the heating means is operated during intermittent driving of the conveying means. 4. The folding molding method according to claim 1, wherein the folding means temporarily bends the synthetic resin plate at a predetermined angle or more, then returns to the predetermined bending angle and cools and fixes. 5. A bending forming apparatus for thermoplastic synthetic resin plates, which sequentially heats a plurality of thermoplastic synthetic resin plates along a folding curve while mechanically bending and discharging the thermoplastic synthetic resin plates. A synthetic resin plate transfer means for picking up one by one from a plurality of thermoplastic synthetic resin plates and sequentially transferring them to a linear synthetic resin plate feeding path, and a thermoplastic resin transferred by the transfer means. A transport unit having a transport unit that positively and intermittently feeds the synthetic resin plate along the feed route; a heating unit extending in the feed route and having a linear heating unit; and the heating unit. A heating section actuating means for intermittently activating, and a bending / fixing step of sequentially bending and fixing the thermoplastic synthetic resin plate which is installed at the downstream end of the feeding path and is fed along the heating wire. A bent forming part having a cooling means, and the bending / cooling means An apparatus for bending a thermoplastic synthetic resin plate, comprising: a discharge chute that receives the thermoplastic synthetic resin plate that has been bent and bent in a predetermined posture and discharges it outside the machine in the same posture. 6. The fold-forming section 6 has the same plane as a number of pairs of conveying rolls on the extension of the feeding path, and a plurality of pairs of synthetic resin plate mounting rolls are arranged in a row, and A bending means for rotating around an axis line on the extension line of the heat bar, a rotating means for rotating the bending means at a predetermined bending angle, and a cooling means for fixing the bent shape. Item 6. The bending apparatus according to Item 5.