JP2012111084A - Smc-molding system and method of producing smc-molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an SMC-molding system that can reduce the percent defective of a molded article without measuring hardness of an SMC sheet when the SMC sheet is molded.SOLUTION: The SMC molding system includes: a carrier device 1 that has a feed roll 11 for intermittently feeding a predetermined quantity of long SMC sheet 20, and a strain-detecting unit 12 for detecting the strain of the SMC sheet when the SMC sheet is stopped; a cutter 2 for cutting the SMC sheet 20 thus fed; a presser 3 for molding the SMC sheet 30 thus cut. The SMC molding system is further provided with a controller 4, wherein the controller adjusts, based on the strain detected by the strain-detecting unit 12, at least one of the quantity of SMC sheet 20 fed by the feed roll 11 of the carrier device 1, heat temperature of the presser 3, and a mold clamping velocity.

Description

  The present invention relates to an SMC molding system and a method for manufacturing an SMC molded article.

  A SMC sheet is produced by sandwiching a resin composition containing a resin, a filler, a curing agent, and the like with glass fibers between two upper and lower release films, and pressing and impregnating with a impregnation apparatus while transporting the sheet in a sheet form. This SMC sheet is wound around the winding shaft in a cylindrical shape and stored, or is stored in a container in a zigzag manner. The SMC sheet pulled out from the winding shaft or the container is transported to a cutting device by a transport device and cut to a predetermined weight (length). The cut SMC sheets are stacked on the lower mold and set to a desired projected area (charge pattern), and the molded product is obtained by lowering the upper mold and pressing it with the upper and lower molds.

  It is important to grasp the hardness of the SMC sheet in the production of the molded product. This is because if the hardness of the SMC sheet set in the lower mold is changed, the fluidity at the time of pressing is changed, which affects productivity such as molding failure. The hardness of the SMC sheet can be accurately grasped by using a hardness measuring instrument or the like, but for that purpose, the SMC sheet is cut into a predetermined size and the hardness measurement is performed, so the productivity increases. It will decline. In view of this, there has been proposed a conveyance device that includes a pair of feed rolls for sandwiching an SMC sheet, and at least one of the rolls is movable in the sandwiching direction of the SMC sheet, and detects the movement distance and outputs the hardness of the SMC sheet. (Patent Document 1).

  In this transport device, a constant pressing force is applied from the feed roll to the SMC sheet passing between the upper and lower rolls of the pair of feed rolls. When the upper roll can move in the SMC sheet clamping direction, the softer the SMC sheet that passes through, the weaker the force against the pressing force of the feed roll, and the upper roll moves downward. The sheet hardness can be grasped. For this reason, the SMC sheet can be easily grasped without cutting the SMC sheet at the time of SMC sheet molding and measuring its hardness with a separate hardness measuring instrument, etc., so the work time until molding can be shortened and the productivity of the molded product can be reduced. Can be improved.

JP 2010-5826 A

  However, when the force of the SMC sheet against the pressing force of the feeding roll against the SMC sheet is weaker, the upper force of the feeding roll may be moved by reflecting the opposing force in the pressing force. There are cases where it is not possible. If it becomes so, the hardness of a SMC sheet cannot fully be grasped but it becomes difficult to obtain a good molded product.

  The present invention has been made in view of the circumstances as described above, and an SMC molding system and an SMC molding that can reduce the defective rate of a molded product without measuring the hardness of the SMC sheet at the time of SMC sheet molding. It is an object to provide a method for manufacturing a product.

  In order to solve the above problems, an SMC molding system of the present invention includes a feed roll that intermittently feeds a long SMC sheet by a predetermined amount, and a deflection amount detection unit that detects a deflection amount when the SMC sheet is stopped. An SMC molding system including a conveying device, a cutting device that cuts a sent SMC sheet, and a press device that molds the cut SMC sheet, based on the deflection amount detected by the deflection amount detection unit. A control device is provided that adjusts at least one of the feed amount of the SMC sheet by the feed roll of the transport device, the heating temperature of the press device, and the mold cutoff speed.

  In this SMC forming system, the transport device is provided with a front receiving roll and a rear receiving roll at a predetermined interval in the transport direction of the SMC sheet, and the front receiving roll and the rear receiving roll are provided with the front receiving roll and the rear receiving roll. It is preferable that the SMC sheet is bridged and conveyed by the feed roll, and the deflection amount detection unit detects the deflection amount of the bridged SMC sheet.

  In the SMC molding system, it is preferable that the transport device is provided with an output unit that outputs the hardness of the SMC sheet based on the deflection amount detected by the deflection amount detection unit.

  The method for producing an SMC molded product of the present invention is a method for producing an SMC molded product by cutting a long SMC sheet that is intermittently delivered by a predetermined amount, and press-molding the cut SMC sheet. The amount of deflection at the time of stopping the SMC sheet to be sent is detected, and based on the amount of deflection, at least one of the amount of feeding of the SMC sheet, the heating temperature at the time of press molding of the SMC sheet, and the die cutoff speed is selected. It is characterized by adjusting.

  ADVANTAGE OF THE INVENTION According to this invention, even if it does not measure the hardness of a SMC sheet at the time of SMC sheet shaping | molding, the defect rate of a molded product can be reduced.

It is the schematic of the SMC shaping | molding system which is one Embodiment of this invention. (A), (b) is a schematic diagram which shows the SMC sheet spanned by the front side receiving roll and the rear side receiving roll. (A), (b) is the graph which showed the fluctuation | variation of the deflection amount in the same SMC sheet.

  The present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic view of an SMC molding system according to an embodiment of the present invention.

  As shown in FIG. 1, a long SMC sheet 20 folded and stored in a container 5 in a zigzag manner is conveyed by the conveying device 1 and sent out to the cutting device 2. The SMC sheet 20 sent out from the conveying device 1 is cut by the cutting device 2. The cut SMC sheets 30 are stacked, set in a desired projection area (charge pattern) on the lower die 31 of the press device 3, and pressed by the upper and lower dies 32, 31 by the lowering of the upper die 32 of the press device 3. As a result, a molded product is obtained. A control device 4 is electrically connected to the transport device 1, and the operation of the transport device 1 is controlled by the control device 4.

  The conveyance device 1 includes a feed roll 11 configured by a pair of rolls that sandwich the SMC sheet 20 and a deflection amount detection unit 12 that detects the deflection amount of the SMC sheet 20. The feed roll 11 is rotationally driven, and the SMC sheet 20 is conveyed and sent out by the rotation of the roll. The feed roll 11 is controlled by the control device 4 so as to perform intermittent operation in which the stop and the operation are alternately repeated, and the stop time and the operation time of the feed roll 11 are also controlled.

  The transport device 1 is provided with a front receiving roll 13 and a rear receiving roll 14 at a predetermined interval in the transport direction of the SMC sheet 20. In FIG. 1, the front receiving roll 13 and the rear receiving roll 14 are provided in the front stage of the feed roll 11 in the conveying direction of the SMC sheet 20, but may be provided in the rear stage. Also, the control device 4 may be electrically connected to the front receiving roll 13 and the rear receiving roll 14 so that the SMC sheet 20 may be conveyed by rotating the roll.

  The SMC sheet 20 pulled out from the container 5 is conveyed by the feed roll 11 so as to be bridged between the front receiving roll 13 and the rear receiving roll 14. When the feed roll 11 is stopped, the SMC sheet 20 spanned between the front receiving roll 13 and the rear receiving roll 14 is bent as shown in FIG. The state of the bent state varies depending on the hardness of the SMC sheet 20.

  FIG. 2A shows a case where the SMC sheet 20 is hard. Since the SMC sheet 20 has high rigidity and small deformation due to its own weight, the deflection amount L is small. On the other hand, FIG. 2B shows a mode in which the SMC sheet 20 is soft. In this aspect, since the SMC sheet 20 has low rigidity and large deformation due to its own weight, the deflection amount L is large.

  As described above, the deflection amount L of the SMC sheet 20 is closely related to the hardness of the SMC sheet 20. Therefore, if the relationship between the hardness of the SMC sheet 20 and the deflection amount L is grasped in advance, the deflection amount detection unit 12 determines the deflection amount L of the SMC sheet 20 when the feeding roll 11 is stopped when the SMC sheet 20 is conveyed. By detecting, the hardness of the SMC sheet 20 can be easily grasped.

  The relationship between the hardness of the SMC sheet 20 and the deflection amount L can be easily grasped from the correspondence data obtained by collecting the correspondence data between the hardness of the SMC sheet 20 and the deflection amount L by the following method, for example. That is, the amount of deflection L is measured for the SMC sheet 20 having a known hardness measured by using a hardness measuring instrument or the like. This is performed for a plurality of SMC sheets 20 having different hardnesses, and data on the hardness of the SMC sheet 20 and the corresponding deflection amount L of the SMC sheet 20 is collected.

  The deflection amount detection unit 12 that detects the deflection amount L of the SMC sheet 20 is, for example, the position of the lowermost end and the uppermost position of the SMC sheet 20 in a state of being bent between the front receiving roll 13 and the rear receiving roll 14. Any distance can be used as long as it can quantitatively detect the distance between the two. For example, a known type such as a non-contact type such as a laser gauge used to measure the distance by irradiating laser light and measuring the reflected light, or a contact type such as a dial gauge is adopted. can do.

  In the present embodiment, when the feed roll 11 whose intermittent operation is controlled by the control device 4 is stopped, the cutting device 2 cuts the SMC sheet 20 and is bridged between the front receiving roll 13 and the rear receiving roll 14. The deflection amount detection unit 12 detects the deflection amount L of the SMC sheet 20 in the state. It is not necessary to interrupt the work for detecting the deflection amount L, and the work time is effectively utilized, so work efficiency is good.

  The control device 4 is composed of, for example, a microcomputer provided with a memory or the like, and is further electrically connected to the press device 3 in this embodiment.

  The control device 4 adjusts the feed amount of the SMC sheet 20 by the feed roll 11 of the transport device 1 based on the deflection amount L of the SMC sheet 20 detected by the deflection amount detection unit 12 of the transport device 1. At least one of the heating temperature and the mold cut-off speed is adjusted. When the heating temperature of the press device 3 and the die cut-off speed are not adjusted, the control device 4 may not be electrically connected to the press device 3.

  In the control device 4, correspondence data between the hardness of the SMC sheet 20 and the deflection amount L is stored in the memory. Furthermore, in addition to data relating to any one of the amount of SMC sheet 20 fed by the feed roll 11 of the transport device 1 according to the hardness of the SMC sheet 20, the mold temperature of the press device 3, and the mold cutoff speed, the transport device 1 and a program for controlling the operation of the press apparatus 3 are also stored in the memory. The program stored in the memory is executed by a microcomputer or the like, and the intermittent operation of the feed roll 11 of the transport device 1, the heating temperature of the press device 3, the die shut-off speed, etc. are appropriately controlled based on the data stored in the memory. Is done.

  Here, the data relating to the feed amount of the SMC sheet 20 by the feed roll 11 of the transport device 1 according to the hardness of the SMC sheet 20 is the hardness of the SMC sheet 20 and the optimum charge pattern of the SMC sheet 30 having the hardness. The data having the information on the correspondence relationship with the feed amount of the SMC sheet 20 for this purpose. The correspondence relationship between the hardness of the SMC sheet 20 and the delivery amount of the SMC sheet 20 for the optimum charge pattern of the SMC sheet 30 having the hardness is obtained based on the following information, for example.

  When the SMC sheet 20 is hard, the fluidity of the SMC sheet 30 in the mold of the press apparatus 3 is small, and when the SMC sheet 20 is soft, the fluidity of the SMC sheet 30 in the mold of the press apparatus 3 is large. If the fluidity of the SMC sheet 20 is small, the flow distance of the SMC sheet 30 set in the press device 3 is small, so that the projected area of the SMC sheet 30 is set to be large. When the flowability of the SMC sheet 20 is large, the flow distance of the SMC sheet 30 set in the press device 3 is increased, so that the projected area of the SMC sheet 30 is set to be small. Then, the length of operation of the rotational drive of the feed roll 11 of the transport device 1 is adjusted to adjust the feed amount of the SMC sheet 20, and a desired charge pattern is obtained by cutting the sent SMC sheet 20 with a cutting device. An SMC sheet 30 is obtained.

  The data relating to the mold temperature of the press device 3 according to the hardness of the SMC sheet 20 corresponds to the hardness of the SMC sheet 20 and the optimum mold temperature of the press device 3 when forming the SMC sheet 30 having the hardness. Data with related information. The correspondence relationship between the hardness of the SMC sheet 20 and the optimum mold temperature of the press device 3 when forming the SMC sheet 30 having the hardness is obtained based on the following information, for example.

  The relationship between the hardness of the SMC sheet 20 and the fluidity of the SMC sheet 30 in the mold of the press device 3 is as described above. If the flowability of the SMC sheet 20 is small, the flow distance of the SMC sheet 30 set in the press apparatus 3 is reduced. Therefore, the mold temperature of the press apparatus 3 is set high so that the flowability of the SMC sheet 30 is increased. . When the flowability of the SMC sheet 20 is large, the flow distance of the SMC sheet 30 set in the press apparatus 3 is increased, so that the mold temperature of the press apparatus 3 is set low so that the flowability of the SMC sheet 30 is decreased. . If the mold temperature is set high, the amount of heat applied to the SMC sheet 30 increases and the fluidity of the SMC sheet 30 in the mold increases. Conversely, if the mold temperature is set to be low, the amount of heat applied to the SMC sheet 30 is reduced, and the fluidity of the SMC sheet 30 in the mold is suppressed.

  Further, the data regarding the die cut-off speed of the press device 3 according to the hardness of the SMC sheet 20 is the optimum die cut-off of the press device 3 when the SMC sheet 30 having the hardness and the hardness of the SMC sheet 20 is formed. Data having information on correspondence with speed. The correspondence relationship between the hardness of the SMC sheet 20 and the optimum die closing speed of the press device 3 when forming the SMC sheet 30 having the hardness is obtained based on, for example, the following information.

  The relationship between the hardness of the SMC sheet 20 and the fluidity of the SMC sheet 30 in the mold of the press device 3 is as described above. If the flowability of the SMC sheet 20 is small, the flow distance of the SMC sheet 30 set in the press device 3 is reduced. Therefore, the die cutoff speed of the press device 3 is set to be slow so that the flowability of the SMC sheet 30 is increased. Is done. When the fluidity of the SMC sheet 20 is large, the flow distance of the SMC sheet 30 set in the press device 3 is increased, so that the die closing speed of the press device 3 is set to be faster so that the fluidity of the SMC sheet 30 is decreased. The If the mold cut-off speed is set to be slow, the amount of heat applied to the SMC sheet 30 increases and the fluidity of the SMC sheet 30 in the mold increases. On the other hand, if the die cut-off speed is set faster, the amount of heat applied to the SMC sheet 30 is reduced, and the fluidity of the SMC sheet 30 in the die is suppressed.

  In the present embodiment, the control device 4 determines the hardness of the SMC sheet 20 from the deflection amount L of the SMC sheet 20 detected by the deflection amount detection unit 12 of the conveying device 1 based on the correspondence data between the hardness of the SMC sheet 20 and the deflection amount L. Get information about

  Then, the SMC sheet 20 feed amount based on the data relating to the feed amount of the SMC sheet 20 by the feed roll 11 of the transport device 1 according to the hardness of the SMC sheet 20, the die temperature of the press device 3, and the die cutoff speed, the press At least one of the heating temperature of the apparatus 3 and the mold cutoff speed is adjusted.

  For example, when the SMC sheet 20 is hard, the operating time of the rotational drive of the feed roll 11 of the transport device 1 is increased in order to obtain the charge pattern of the SMC sheet 30 that is set in the press device 3 and has a large projected area. Adjustment is made so that the feed amount of the SMC sheet 20 is increased. Alternatively, the mold temperature of the press device 3 is adjusted to be higher. Alternatively, the die cutoff speed of the press device 3 is adjusted to be slow. All of these can be adjusted, or any two can be selected and adjusted.

  By adjusting the feed amount of the SMC sheet 20 by the feed roll 11, the SMC sheet 20 having a predetermined length is sent to the cutting device 2 and cut into a predetermined length, thereby obtaining the SMC sheet 30 having a large projected area. As a result, it is possible to prevent the occurrence of unfilled (insufficient thickness) defects and scraping defects during the molding of the SMC sheet 30, and the defective rate of the molded product can be reduced. Further, the fluidity of the SMC sheet 30 in the mold is increased by adjusting the mold temperature of the press device 3 to be higher or by adjusting the mold cut-off speed slower. As a result, it is possible to prevent the occurrence of unfilled (insufficient thickness) defects and scraping defects during the molding of the SMC sheet 30, and the defective rate of the molded product can be reduced.

  On the other hand, when the SMC sheet 20 is soft, the operation time of the rotational drive of the feed roll 11 of the transport device 1 is shortened in order to obtain the charge pattern of the SMC sheet 30 set in the press device 3 and having a small projected area. Adjustment is made so that the delivery amount of the SMC sheet 20 is reduced. Alternatively, the mold temperature of the press device 3 is adjusted to be low. Alternatively, the die cutoff speed of the press device 3 is adjusted to be faster. All of these can be adjusted, or any two can be selected and adjusted.

  By adjusting the feed amount of the SMC sheet 20 by the feed roll 11, the SMC sheet 20 having a predetermined length is sent to the cutting device 2, cut into a predetermined length, and the SMC sheet 30 having a small projected area is obtained. As a result, it is possible to prevent the occurrence of pinhole defects on the surface of the molded product, and to reduce the defective rate of the molded product. Further, the fluidity of the SMC sheet 30 in the mold is suppressed by adjusting the mold temperature of the press device 3 to be low or adjusting the mold cutoff speed to be high. As a result, it is possible to prevent the occurrence of pinhole defects on the surface of the molded product, and to reduce the defective rate of the molded product.

  In the detection of the deflection amount of the SMC sheet 20 by the deflection amount detection unit 12 of the transport device 1, even if the same SMC sheet 20 is stored in the same container 5, due to other factors such as irregularities and folds on the surface of the SMC sheet 20 The deflection amount L may vary. FIG. 3A is a graph showing the variation in the amount of deflection in the same SMC sheet. The vertical axis represents the amount of deflection, and the horizontal axis represents the time axis when the amount of deflection at the time of stopping the same SMC sheet that is intermittently fed is sequentially detected. The solid line is a graph showing the variation of the deflection amount of the soft SMC sheet, and the dotted line is the graph showing the variation of the deflection amount of the hard SMC sheet.

  Thus, even if the information on the hardness of the SMC sheet is obtained from the detection result of the deflection amount having a large fluctuation in the same SMC sheet, it may not be said that the information is more accurate. Therefore, as shown in FIG. 3 (b), the amount of deflection of the SMC sheet is subjected to a moving average process a certain number of times, and more accurate information can be obtained by obtaining information on the hardness of the SMC sheet from this result. Such processing can be performed by a control device, for example.

  Furthermore, in this embodiment, the information on the hardness of the SMC sheet 20 obtained in the control device 4 may be output to the output unit 15 such as a monitor or a printer. The output unit 15 is electrically connected to the deflection amount detection unit 12 of the transport device 1.

  For example, if the output unit 15 is configured by a monitor, the hardness of the SMC sheet 20 can be digitally displayed. If the information on the hardness of the SMC sheet 20 is output to the output unit 15, the person in charge of molding can easily grasp the hardness of the SMC sheet 20. The person in charge of molding can adjust any of the feed amount of the SMC sheet 20 that is not controlled by the control device 4, the mold temperature of the press device 3, and the mold cutoff speed based on the knowledge obtained through experience.

  As described above, the control device 4 and the person in charge of molding adjust any one of the feed amount of the SMC sheet 20, the mold temperature of the press device 3, and the mold shut-off speed, so that the defective rate of the molded product can be more reliably reduced. Can do.

  Examples of the present invention are shown below, but the present invention is not limited thereto.

<Example 1>
In the SMC molding system shown in FIG. 1, an SMC sheet was molded to obtain a bathtub having a weight of 21 kg as a molded product.

Conventionally, a long SMC sheet having a standard hardness of 6 kg / m ² and a width of 1 m is cut into a length of 500 mm with a cutting device, and after laminating seven of these, a lower die of the press device And was molded by heating and pressing. The defective rate of the molded product was 30%. The amount of deflection of the long SMC sheet having the standard hardness used for this molding was 100 mm. Moreover, the standard speed of the mold cut-off speed at the time of molding was set to 1 mm / second when the distance between the upper mold and the lower mold until the mold was completely closed was 0-30 mm. .

  In this embodiment, the deflection amount detection unit 12 of the transport apparatus 1 detects the deflection amount of the long SMC sheet 20 having the above-described standard hardness, and this is subjected to a moving average process five times. Based on the average deflection amount, the feed amount of the SMC sheet 20 by the feed roll 11 of the transport device 1 is adjusted by the control device 4 so as to be 600 mm longer than the conventional length of 500 mm, and this is cut. The device 2 was cut. Seven of the cut SMC sheets 30 were stacked, set in the lower mold 31 of the press device 3 and molded by heating and pressing. At the time of molding, based on the average amount of deflection, the mold cutoff speed of the press device 3 was further adjusted from the conventional 1 mm / second to 0.7 mm / second by the control device.

  The control device 4 stores correspondence data between the hardness of the SMC sheet 20 and the amount of deflection. Further, data relating to any one of the feed amount of the SMC sheet 20 by the feed roll 11 of the transport device 1, the die temperature of the press device 3, and the die shut-off speed according to the hardness of the SMC sheet 20 is also stored. .

  The defective rate of the obtained molded product was 20%, and it was confirmed that the defective rate was lower than before.

<Example 2>
Using the SMC sheet 20 accommodated in a container different from the container in which the SMC sheet 20 used in Example 1 was accommodated, molding was performed in the same manner as in Example 1.

  In this embodiment, based on the average deflection amount, the control device 4 adjusts the feed amount of the SMC sheet 20 by the feed roll 11 of the transport device 1 so as to be 400 mm shorter than the conventional length of 500 mm. This was cut with the cutting device 2. Seven of the cut SMC sheets 30 were stacked, set in the lower mold 31 of the press device 3 and molded by heating and pressing. At the time of molding, based on the average amount of deflection, the mold cutoff speed of the press device 3 was further adjusted by the control device 4 from the conventional 1 mm / second to 1.3 mm / second.

  The defective rate of the obtained molded product was 20%, and it was confirmed that the defective rate was lower than before.

DESCRIPTION OF SYMBOLS 1 Conveyance apparatus 11 Feed roll 12 Deflection amount detection part 13 Front side receiving roll 14 Rear side receiving roll 15 Output part 2 Cutting apparatus 3 Press apparatus 31 Lower mold 32 Upper mold 4 Control apparatus 20, 30 SMC sheet

Claims (4)

  A conveying device having a feed roll that intermittently feeds a long SMC sheet by a predetermined amount and a deflection amount detection unit that detects a deflection amount when the SMC sheet is stopped, a cutting device that cuts the sent SMC sheet, and a cutting device An SMC molding system comprising a press device for molding the SMC sheet, and based on the deflection amount detected by the deflection amount detection unit, the feed amount of the SMC sheet by the feed roll of the transport device, A SMC molding system, characterized in that a control device for adjusting at least one of a heating temperature of the press device and a die cutoff speed is provided.   The transport device is provided with a front receiving roll and a rear receiving roll at a predetermined interval in the transport direction of the SMC sheet, and the SMC sheet is bridged between the front receiving roll and the rear receiving roll. The SMC molding system according to claim 1, wherein the deflection amount detection unit that is conveyed by the feed roll detects a deflection amount of the SMC sheet that is bridged.   The SMC according to claim 1, wherein the transport device is provided with an output unit that outputs the hardness of the SMC sheet based on a deflection amount detected by the deflection amount detection unit. Molding system.   A method of manufacturing an SMC molded product that cuts a long SMC sheet that is intermittently delivered by a predetermined amount and press-molds the cut SMC sheet, wherein the deflection amount at the time of stopping the SMC sheet that is intermittently delivered And adjusting at least one of the feed amount of the SMC sheet, the heating temperature during the press molding of the SMC sheet, and the die cut-off speed based on the deflection amount of the SMC molded product, Production method.

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