JPH05329873A - Rotary molding system - Google Patents

Abstract

PURPOSE:To smoothly transport molds to enhance a productivity by a method wherein a mold lower than an object temperature in an annealing station in a rotary injection molding system is again transported toward an annealing system inlet in a rotary form to be annealed. CONSTITUTION:In an annealing station 4 provided succeeding to an injecting station, a rotary transport path 13 is provided for transporting a plurality of molds 6 from an inlet toward the same inlet in a rotary form. On the transport path 13, cooling devices 14-21 are disposed. Each of the cooling devices is composed of a cooling block containing a cooling medium circulating inside and having a uniform temperature distribution and provided with a temperature measuring device for detecting a mold temperature. The molds are brought into contact with the cooling devices 14-21 to be annealed. In the vicinity of an outlet of the annealing station 4, a branching stage 33 provided with a temperature measuring device 34 for detecting the temperature of the mold 6 is disposed. A controller judges whether the mold 6 is transported again toward the inlet or toward a molded piece delivery station 5 by comparing the detection temperature of the temperature measuring device 34 with an object temperature, thereafter changing over the transport path.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary molding system, and more particularly, to a predetermined heating station and injection molding station for a pair of molds in which each unit has a cavity formed therein through a transfer means. The present invention relates to a rotary molding system for molding a molded product having a high dimensional accuracy and a small internal strain by sequentially transferring a slow cooling station and a molded product take-out station in this order.

[0002]

2. Description of the Related Art In recent years, various types of injection molding that take advantage of molding by improving the precision of plastic molding, etc.
For example, a plastic lens such as an aspherical lens (optical element) is injection-molded. In the conventional molding apparatus of this type, the resin injected from the injection molding machine is cooled and cured on the spot to take out the resin from the mold, and then the next resin is injected again into the mold. There is something
By uniformly cooling the mold after the injection molding, it is possible to obtain a molded product with high dimensional accuracy and less internal distortion.

Conventionally, as such a slow cooling device, for example, JP-A-61-287710 and JP-A-62-6.
0622, JP-A-62-117716, JP-A-62-105615, or JP-A-3-164.
There is one described in Japanese Patent Publication No. 210. In these products, a cooling hole is provided in a mold, and a cooling medium is flown into the cooling hole to gradually cool the molded product.

In addition to the above, Japanese Patent Laid-Open No. 61-279515
There is one such as that described in Japanese Patent Laid-Open Publication No. 2003-242242, in which a heating member and a cooling member are formed from the same member, and a temperature sensor is arranged in the same place as the heating member and the cooling member, thereby The temperature of heating and cooling is adjusted uniformly. By the way, in the injection molding apparatus adopting these slow cooling methods, the resin injected from the injection molding machine is cooled and hardened on the spot to take out the resin from the mold, and then the resin is injected into the mold again. Since the resin of No. 1 is injected, the next resin cannot be injected into the mold by the injection molding machine until the resin is cured, so not only is the usage efficiency extremely poor, but the resin in the exit passage of the injection molding machine The problem that it hardened has occurred.

As a means for preventing such a problem from occurring, for example, there is one described in Japanese Patent Laid-Open No. 3-36005. This one prepares a plurality of molds, transfers the molds in which the resin is injected by the injection molding machine to a plurality of cooling press machines provided at different places, and then gradually cools by each cooling machine, After gradually cooling, the mold is transferred to the molded product ejection station.

In this type of rotary molding system, since the slow cooling rate and the mold temperature at the time of taking out the molded product have a great influence on the quality of the molded product, these must be controlled with high control. In addition, the temperature of the mold tends to become non-uniform during slow cooling, so it is necessary to make the temperature of the mold uniform. Therefore, in this conventional example,
In order to satisfy the above requirements, a cooling press, a cooling temperature detecting means, a measuring means for measuring the cooling time of the mold,
A mold for storing a cooling curve showing a temperature corresponding to a cooling time according to a molded product to be injection-molded and a controller for controlling a mold to be taken out from the cooler are provided, and the mold is formed by using a traverser. By adopting a system that prevents the mold from staying in one place by controlling the transfer speed and transfer waiting time of the mold, the transfer of the mold to the cooling press is smoothed and the efficiency of use of the mold is improved. I am trying to improve.

[0007]

However, in such a rotary molding system, after transferring the molds to a plurality of cooling presses, the cooling presses are gradually cooled by the respective cooling presses, and after gradually cooling. Since the mold is being transferred to the molded product unloading station, the cooling press cannot be used to cool the next mold while the mold is present in the cooling press until the target temperature is reached. There was a problem that the efficiency deteriorates, and as a result, the mold cannot be cooled smoothly.

In order to solve such a problem, it is conceivable to increase the number of cooling presses. However, if the number of cooling presses is increased, there is a problem that the cost increases accordingly. Therefore, there is a demand for a rotary molding system that can smoothly transfer the mold and improve the usage efficiency of the mold. Therefore, in the present invention, the mold which has not reached the target temperature at the time of slow cooling is again transferred to the inlet of the slow cooling station in a rotary manner to perform slow cooling again, and the mold is smoothly transferred. An object of the present invention is to provide a rotary molding system capable of improving the productivity of a resin molded product and molding a uniform and highly accurate resin molded product.

[0009]

The invention according to claim 1 is
In order to solve the above problems, a pair of molds in which each unit has a cavity formed therein are provided with a predetermined heating station, an injection molding station, a slow cooling station and a molded product unloading station through transfer means. In the rotary molding system for molding a molded product by sequentially transferring sequentially, the slow cooling station is a rotary transfer means for transferring a plurality of molds from an inlet to the inlet again in a rotary manner, and a rotary transfer means on the transfer means. A plurality of gradual cooling devices each having a cooling block in which a cooling medium is circulated and a temperature distribution is uniform while being disposed, and a temperature measuring device provided in the gradual cooling device and measuring the temperature of the mold. The cooling block is brought into contact with a mold which is rotary-moved on the rotary transfer means to gradually cool the mold. It is characterized in that it has to so that.

In order to solve the above-mentioned problems, the slow cooling station has a soaking unit between predetermined annealing units, and the annealing unit produces the soaking unit. The feature is that the temperature distribution is made uniform. In order to solve the above-mentioned problems, the invention according to claim 3 provides a heating and warming station between the slow cooling station and the molded product take-out station, and the heating and warming station causes the mold to move from the slow cooling station to the molded product. Transfer means for transferring to the take-out station,
A plurality of heating and heat-retaining devices arranged on the transfer means to keep the temperature of the mold constant.

In order to solve the above-mentioned problems, a fourth aspect of the present invention provides a transfer path or a molded product take-out station near the exit of the slow cooling station for transferring the mold toward the inlet of the slow cooling station again. Is provided with a branching unit that is switch-connected to a transfer path for moving toward the mold, and the branching unit connects the temperature measuring device that measures the temperature of the mold and the transfer route of the mold based on the detection information of the temperature measuring device. And a control means for selecting.

[0012]

According to the first aspect of the present invention, rotary transfer means for transferring a plurality of molds from the inlet of the slow cooling station to the inlet again in a rotary manner, and a rotary transfer means disposed on the transfer means and internally A plurality of gradual cooling devices having a cooling block in which a cooling medium is circulated and having a uniform temperature distribution, and a temperature measuring device provided in the gradual cooling device to measure the temperature of the mold are provided, and the temperature is set on the rotary transfer means. The mold is gradually cooled by bringing the cooling block into contact with the mold transferred in a rotary manner.

Therefore, when the mold transferred from the slow cooling station to the molded product take-out station is not cooled to the target slow cooling temperature, the mold is again transferred to the inlet of the slow cooling station and slowly cooled again. It As a result, the mold can be smoothly transferred without being retained, the productivity of the resin molded product can be improved, and a uniform and highly accurate resin molded product can be molded.

According to the second aspect of the invention, the temperature distribution produced by the slow cooling device is made uniform by the soaking means provided between the slow cooling devices. Therefore, the non-uniform temperature distribution of the mold that occurs during slow cooling is removed. As a result, deformation of the resin due to thermal strain is prevented, and a molded product with high dimensional accuracy and low internal strain can be obtained. In the invention according to claim 3, a heating and heat retaining station is provided between the slow cooling station and the molded product take-out station, and the heating and warming station transfers the mold toward the gradually cooling station and the molded product take-out station. And a plurality of heating and heat-retaining devices which are disposed on the transfer means and keep the temperature of the mold constant.

Therefore, when the mold gradually cooled to the target temperature in the slow cooling station is kept at the target temperature until it is transferred to the molded product take-out station, and the mold remains in the take-out station. The mold temperature of the subsequent mold does not decrease. As a result, a uniform and highly accurate resin molded product is molded. In the invention according to claim 4, a branch which is switched and connected near the exit of the slow cooling station to a transfer path for transferring the mold toward the inlet of the slow cooling station again or a transfer path for transferring the mold toward the molded product take-out station. Means are provided, and the mold transfer path is selected by detecting the temperature of the mold on the branching means.
Therefore, the branch means determines the final transfer path of the mold, and the fine adjustment of the temperature of the mold is easily performed.

[0016]

EXAMPLES The present invention will be described below based on examples.
1 and 2 are views showing an embodiment of a rotary molding system according to the invention described in any one of claims 1 to 4. First, the configuration will be described. In FIG. 1, reference numeral 1 is a rotary molding system, and the molding system 1 includes a heating station 2, an injection molding station 3, and a slow cooling station 4.
And a molded product take-out station 5. Although not shown, the dies 6 transferred by the rotary molding system 1 are a pair of dies in which each unit forms a cavity therein, as is well known, and the pair of dies are self-holding such as screws. The mechanisms are connected to each other so as to self-hold the force in the mold clamping direction.

The stations 2 to 5 are connected via a transfer path 7 such as a belt conveyor as transfer means, and the mold 6 is connected to the stations 2 to 5 via the transfer path 7.
Transferred between. The heating station 2 has a plurality of heating devices 11, and the heating device 11 heats the mold 6 to a target temperature. The injection molding station 3 has an injection molding machine 12 and is configured to inject and fill molten resin into the cavity of the mold 6.

The molded product take-out station 5 is equipped with a mold opening / closing device, a take-out robot, a pallet, etc., which are not shown, so that the self-holding function of the mold 6 can be released or the self-holding function can be given. Then, the resin molded product is taken out from the mold 6 in which the self-holding function is released and is transferred to the heating station 2 again. On the other hand, the slow cooling station 4 is provided with a rotary transfer path 13 such as a belt conveyor as a rotary transfer means for transferring a plurality of molds 6 from the entrance to the entrance again in a rotary manner. A plurality of slow cooling devices 14 to 21 are arranged in the.

Each of the slow cooling devices 14 to 21 has a cooling block in which a cooling medium is circulated and has a uniform temperature distribution. The cooling block is brought into contact with the mold 6 to slowly cool the mold 6. It is like this. Further, the slow cooling devices 14 to 21 are provided with temperature measuring devices 23 to 30, respectively.
Is adapted to detect the temperature of the mold 6. Further, a branch stage 32 is provided at the inlet of the slow cooling station 4, and the branch stage 32 is composed of a direction changer using a roller. The path for transferring to the cooling station 4 and the path for returning the mold 6 from the exit side of the slow cooling station 4 are connected.

A branch stage 33 is provided near the outlet of the slow cooling station 4 as a branching means. The branch stage 33 is composed of a direction changer using a roller and can rotate 90 °. Thus, the mold 6 is switched and connected to the transfer path for transferring the mold 6 toward the inlet of the slow cooling station 4 again or the transfer path for transferring the mold 6 toward the molded product take-out station 5.

The branch stage 33 is provided with a temperature measuring device 34 for measuring the temperature of the mold 6, so that information detected by the temperature measuring device 34 is output to a branch control device 35 as a control means. It has become. The branch control device 35 has a computer, compares the target slow cooling temperature of the mold 6 set in the internal program with the detection information of the temperature measuring device 34, and compares the branch stage 33.
To determine the transfer route.

Further, between the slow cooling devices 15 to 17, soaking parts 36, 37 and 39 as soaking means are provided between the slow cooling devices, and the soaking parts 36 to 39 are The temperature distribution produced by the slow cooling devices 15 to 17 by air cooling is made uniform. In addition, the slow cooling station 4 and the molded product take-out station 5
In between, a heat insulation station 41 is provided,
The heating / warming station 41 has a transfer path 42 composed of a belt conveyor or the like as a transfer means for transferring the mold 6 toward the slow cooling station 4 and the molded product take-out station 5. Heating and heat-retaining devices 43 and 44 are provided on the transfer path 42, and the heat-retaining devices 43 and 44 keep the temperature of the mold 6 constant.

Further, a rotary transfer path 45 is provided from the outlet of the heating and heat retaining station 41 toward the inlet,
Also on the transfer path 45, a plurality of heating and heat retaining devices 46 to 52 for keeping the temperature of the mold 6 constant are provided. A branch stage 53 is provided at the entrance of the heating / warming station 41, and the branch stage 53 is composed of a direction changer using a roller, and by rotating 90 °, the transfer path 42 and the rotary transfer path. It is designed to be connected to either one of the 45.

Further, a branch stage 54 is provided at the outlet of the heating / warming station 41, and the branch stage 54 is composed of a direction changer using rollers, and is rotated by 90 ° so that the transfer path is moved. 42 and the molded product take-out station 5, or the transfer path 42 and the rotary transfer path 45. The branch stage 54 is provided with a temperature measuring device 55, which detects the temperature of the mold 6 and outputs the detected information to the branch control device 35. The branch controller 35 determines the transfer path of the branch stage 54 by comparing the target slow cooling temperature of the mold 6 set in the internal program with the detection information of the temperature measuring device 55.

Next, the operation will be described. The die 6 to which the self-holding function is given by the die opening / closing device in the take-out station 5 is heated to a substantially glass transition point by the heating device 12, and then transferred to the injection filling station 3, where the injection molding station 3 inside the cavity. Molten resin is injected and filled in.

The mold 6 filled with the molten resin is transferred to the slow cooling station 4. Hereinafter, the processing in the slow cooling station 4 will be described based on the flowchart shown in FIG. The flowchart of FIG. 2 is executed by the slow cooling work program stored in the branch control device 35. First, after being transferred from the injection molding station in step S1, it is transferred to the transfer path 13 through the branch stage 32 in step S2 as shown by the arrow a. Next, in step S3, the mold 6 is cooled by the slow cooling devices 14 and 15. At this time, the die 6 is cooled by the temperature measuring devices 23 and 24 of the slow cooling devices 14 and 15.
After the temperature is measured and the temperature of the cooling block is adjusted from the temperature measurement result, the cooling block is brought into contact with the mold 6 to gradually cool the mold 6. After the gradual cooling, the heat equalizing section 36 equalizes the temperature of the mold 6. Thereafter, in the same manner, the die 6 is gradually cooled and soaked by the soaking units 16, 17 soaking sections 37, 38.

Next, after the mold 6 is transferred to the branch stage 33, the temperature is measured on the branch stage 33, and it is determined in step S4 whether or not the mold temperature is below the target temperature. If there is, it proceeds to step S2 and is transferred to the rotary transfer path 13, and the slow cooling devices 18 to 21 of the rotary transfer path 13 are transferred.
The mold 6 is gradually cooled again. On the other hand, step S4
When it is determined that the mold temperature is equal to or lower than the target temperature, the process proceeds to step S5 and is transferred to the branch stage 53 as shown by the arrow b. Next, in step S6, the mold 6 is transferred to the transfer path 42 and heated and kept at a constant temperature by the heating and keeping devices 43 and 44. Next, in S7, the mold 6 is transferred to the branch stage 54, and the mold temperature is measured by the temperature measuring device 55 on the branch stage 54.

At this time, if the mold temperature matches the target temperature and it is determined that the mold take-out station 5 does not retain the mold, the process proceeds to step S8. In step S8, as shown by the arrow c, the molded product is transferred to the molding product take-out station 5, where the mold 6 is opened to take out the molded product, and then the mold is clamped again to perform the heating station. Transferred to 2.

On the other hand, if the mold temperature does not match the target temperature in step S7 and the mold remains in the molded product take-out station 5, the process proceeds to step S5, and the rotary transfer path 45 is provided as indicated by arrow d. The mold is transferred, and the heat insulation devices 46 to 52 heat the mold again. As described above, in this embodiment, the rotary transfer path 13 for transferring the plurality of molds 6 from the entrance of the slow cooling station 4 toward the entrance again in a rotary manner, and the rotary transfer path 13 are disposed on the transfer path 13. In addition, a plurality of slow cooling devices 14 to 21 each having a cooling block in which a cooling medium is circulated and a temperature distribution is uniform, and a slow cooling device.
14 to 21, temperature measuring device 23 to measure the temperature of the mold 6
30 is provided, and the mold 6 is gradually cooled by bringing the cooling block into contact with the mold 6 that is transferred in a rotary manner on the rotary transfer path 13. When the mold 6 transferred to 5 is not cooled to the target slow cooling temperature, the mold 6 can be transferred again to the inlet of the slow cooling station 4 and slowly cooled again. As a result, the die 6 can be prevented from staying and smoothly transferred, the productivity of the resin molded product can be improved, and a uniform and highly accurate resin molded product can be molded. ..

Further, since the temperature equalizing parts 36 to 38 provided between the slow cooling devices 15 to 17 are intended to equalize the temperature distribution generated by the slow cooling devices 14 to 17, the slow cooling is performed. It is possible to eliminate the non-uniform temperature distribution of the mold 6 that occurs during the process. As a result, it is possible to prevent deformation of the resin due to thermal strain, and it is possible to obtain a molded product with high dimensional accuracy and low internal strain.

Further, a heating / warming station 41 is provided between the slow cooling station 4 and the molded product take-out station 5.
The heating and heat retaining station 41 is disposed on the rotary transfer path 45 for transferring the mold 6 from the slow cooling station 4 toward the molded product take-out station 5 and the transfer path 45 to keep the temperature of the mold 6 constant. Hold multiple heating and heat retaining devices 43, 44
And 46 to 52, it is possible to maintain the target temperature until the mold 6 that has been gradually cooled to the target temperature in the slow cooling station 4 is transferred to the molded product taking station 5. It is possible to prevent the mold temperature of the succeeding mold 6 from being lowered when the mold 6 stays at 5 or the like. As a result, a uniform and highly accurate resin molded product can be molded.

Further, in the vicinity of the outlet of the slow cooling station 4, a transfer path for transferring the mold 6 toward the inlet of the slow cooling station 4 again or a molded product take-out station 5
A branch stage 54 that is switch-connected to the transfer path for moving toward the side is provided, and the transfer path of the mold 6 is selected by detecting the temperature of the mold 6 on the branch stage 54. The final transfer route of the mold 6 can be determined by 54, and fine adjustment of the mold temperature can be easily performed.

[0033]

According to the first aspect of the present invention, when the mold transferred from the slow cooling station to the molded product take-out station is not cooled to the target slow cooling temperature, the mold is again cooled at the slow cooling station. It can be transferred to the inlet of and cooled down again. As a result, the mold can be prevented from staying and smoothly transferred, the productivity of the resin molded product can be improved, and a uniform and highly accurate resin molded product can be molded.

According to the second aspect of the present invention, it is possible to eliminate the non-uniform temperature distribution of the mold that occurs during slow cooling. As a result, it is possible to prevent deformation of the resin due to thermal strain, and it is possible to obtain a molded product with high dimensional accuracy and low internal strain. According to the third aspect of the invention, the mold that has been gradually cooled to the target temperature in the slow cooling station can be kept at the target temperature until it is transferred to the molded product take-out station, and the mold stays in the take-out station. It is possible to prevent the die temperature of the subsequent die from being lowered when the die is operating. As a result, a uniform and highly accurate resin molded product can be molded.

According to the invention described in claim 4, the final transfer route of the mold can be determined by the branching means,
Fine adjustment of the mold temperature can be easily performed.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an embodiment of a rotary molding system according to the present invention.

FIG. 2 is a flowchart of a slow cooling operation performed by a branch control device.

[Explanation of symbols]

 1 rotary molding system 2 heating station 3 injection molding station 4 slow cooling station 5 molded product take-out station 6 mold 7 transfer path (transfer means) 13 rotary transfer path 14-21 slow cooling device 23-30 temperature measuring device 33 branch stage ( (Branching means) 34 Temperature measuring instrument 35 Branching control device (control means) 36 Heat soaking unit (heat soaking means) 41 Heating / keeping station 43, 44, 46 to 52 Heating / keeping device 45 Rotary transfer path

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Osamu Nakayama 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd.

Claims (4)

[Claims] 1. A pair of molds in which each unit has a cavity formed therein are sequentially transferred to a predetermined heating station, an injection molding station, a slow cooling station, and a molded product unloading station in order through transfer means. Thus, in the rotary molding system for molding a molded product, the slow cooling station is arranged on the rotary transfer means for transferring a plurality of molds from an inlet to the inlet again in a rotary manner, and on the transfer means. In addition, a plurality of gradual cooling devices having a cooling block in which a cooling medium is circulated inside and a temperature distribution is uniform, and a temperature measuring device provided in the gradual cooling device and measuring the temperature of the mold are provided. To the mold transferred in a rotary manner on the means,
A rotary molding system characterized in that the mold is gradually cooled by bringing the cooling blocks into contact with each other. 2. The gradual cooling station has a soaking means between predetermined gradual cooling devices, so that the temperature distribution produced by the gradual cooling device is soaked by the soaking device. The rotary molding system according to claim 1, which is characterized in that. 3. A heating and warming station is provided between the slow cooling station and the molded product take-out station, and the heating and warming station transfers the mold from the slow cooling station to the molded product take-out station.
The rotary molding system according to claim 1 or 2, further comprising a plurality of heating and heat retaining devices which are disposed on the transfer means and which keep the temperature of the mold constant. 4. A branching means switchably connected near the exit of the slow cooling station to a transfer path for transferring the mold again toward the inlet of the slow cooling station or a transfer path for transferring the mold toward the molded product take-out station. The branch means is provided, and has a temperature measuring device for measuring the temperature of the mold, and a control means for selecting a mold transfer path based on detection information of the temperature measuring device. The rotary molding system according to any one of Items 1 to 3.