JP6916518B2 - Manufacturing method of injection molding die, molding method by injection molding die, injection molding die and molded product - Google Patents

Description

The present invention relates to a method for producing an injection molding die, a molding method using an injection molding die, an injection molding die, and a molded product. In particular, the present invention relates to a method for producing an injection molding die suitable for producing a game board provided in a pachinko game machine, an arrange ball game machine, a sparrow ball game machine, or the like.

When manufacturing a mold for injection molding, the mold is manufactured in consideration of the molding shrinkage rate of the resin used for molding in advance with respect to the design data of the product.

However, even if a predetermined molding shrinkage is taken into consideration, the injection-molded product may have various defects such as warpage and sink marks, and the molding shrinkage may occur uniformly depending on the thickness and shape of the product. Therefore, it is not easy to produce a molded product with high dimensional accuracy.

Conventionally, errors and deviations in the molding dimensions of such molded products are optimal after trial and error by adjusting various molding conditions such as injection pressure, injection speed, cylinder temperature, mold temperature, and cooling time during mass production. We have found the molding conditions and adjusted them so that the error becomes as small as possible.

In recent years, based on these facts, various techniques for analyzing the optimum molding conditions on a computer by CAE simulation have been proposed (Patent Document 1). However, the analysis result by simulation does not always exactly match the actual molding, and in the end, it is often necessary to reset the optimum molding conditions. On the contrary, there was a problem that it became difficult to find out what was the problem.

Japanese Unexamined Patent Publication No. 2001-246655

Therefore, the present invention has been made in view of the above problems, and is a molded product with higher position accuracy for a part that requires accuracy as compared with some other parts such as an assembly boss and a positioning boss. The main purpose is to provide a method for producing an injection molding die, a molding method using an injection molding die, and a mold, and to provide a molded product produced by these injection molding dies. ..

The present invention has taken the following measures to achieve the above-mentioned main object.

The present invention is a method for producing an injection molding die for molding a molded product having an assembly or positioning boss, which comprises the following steps (1) to (4). A method for producing a mold and a mold for injection molding produced by this production method are provided.
(1) Based on the design data of the molded product, an arbitrary reference point is determined, and at least a part of the boss or rib used for assembly or positioning (hereinafter referred to as "correction target boss, etc.") is designed. Temporary mold processing step of producing a temporary mold processed so as to be produced in a form smaller than the data (2) Using the temporary mold, a predetermined injection pressure, injection speed, cylinder temperature, mold temperature, Temporary molding process of molding a temporary molded product according to molding conditions such as cooling time (3) Temporary molding that measures the positional relationship between the reference point of the temporary molded product and the boss to be corrected and measures the positional deviation with respect to the design data. Product measurement step (4) This mold processing step of correcting the position of the correction target boss or the like based on the measurement result of the positional deviation by the temporarily molded product measurement step and processing the correction target boss or the like.

In the resin molded product, the assembling boss, the positioning boss, the rib, or the like may be required to have higher position accuracy than the outer peripheral shape or the like. The present invention provides a method for manufacturing a mold capable of molding such an assembly boss or the like, which requires higher position accuracy, at an accurate relative position. By using the injection molding die according to the manufacturing method according to the present invention, the position deviation of the correction target boss or the like with respect to the reference point is small, and the assembly boss or the like can be molded at an accurate position with respect to the reference point. can. In the injection molding die produced in this way, the pitch between the reference point and the boss to be corrected and the pitch between the reference point and the portion other than the boss to be corrected are produced at different ratios with respect to the design data. , The pitch between the reference point and the boss to be corrected can be a molding die capable of manufacturing a molded product whose pitch is closer to the value of the design data with respect to the pitch with respect to other parts.

Further, in the method for manufacturing an injection molding die according to the present invention, the reference point may be an assembly boss or a positioning boss.

By using the reference point itself as the assembly boss or the positioning boss as the reference point, the positional relationship between the assembly bosses or the positioning bosses is accurately provided, so that the assembled product is assembled at a more accurate position. be able to.

Further, in the method for producing an injection molding die according to the present invention,
In the temporary mold processing process
The bosses or ribs used for assembly or positioning other than the reference point are divided into a plurality of groups, and one or two or more of the bosses or ribs in each group are designated as correction target bosses or the like. It may be.

When selecting the boss to be corrected, the bosses or ribs used for assembly or positioning in the vicinity are specified as one group, and one or two or more of the bosses to be corrected are set as the boss to be corrected. It was done. By adopting such a configuration, the number of correction target bosses or ribs to be measured can be reduced, so that the measurement work in the temporarily molded product measurement step can be reduced.

Further, in the method for producing an injection molding die according to the present invention,
In the temporary mold processing step, the bosses or ribs of each group other than the correction target bosses and the like may be characterized in that they are not processed.

By identifying nearby bosses or ribs used for assembly or positioning as one group, setting one or two or more of them as correction target bosses, and not processing other bosses in the temporary mold processing process. , It is possible to reduce the work of mold processing in the temporary mold processing process.

Further, in the method for producing an injection molding die according to the present invention,
In the main mold processing process, the bosses or ribs of each group not processed in the temporary mold processing process other than the correction target bosses and the like are processed based on the reference bosses or the correction target bosses of each group. It may be characterized in that.

The bosses or ribs that were not processed in the temporary processing process are processed in the main mold processing process. Since the correction values of the reference point and the correction target boss of each group are known, processing is performed based on this correction value, or main processing is performed based on the correction target boss whose position has already been corrected. As a result, the boss or rib that has not been machined in the temporary machining process can be machined at an accurate position.

The present invention is characterized in that, using the above-mentioned mold, the molding conditions for injection molding are the same as or close to the molding conditions determined in the temporary molding step. I will provide a.

Since the present invention corrects the misalignment between the reference point and the boss to be corrected under the molding conditions in the temporary molding process, the misalignment correction can be performed more accurately by molding under the same molding conditions as in the temporary molding process. By reflecting this, it is possible to produce a molded product that is more accurate in the design data.

Furthermore, the present invention provides a molded product and a game board molded by the above-mentioned manufacturing method.

FIG. 1 is a flowchart of a method for manufacturing an injection molding die according to the first embodiment. FIG. 2 is a perspective view showing an example of a game plate 10 molded by the injection molding die according to the first embodiment. FIG. 3 is a rear view of the gaming machine 10 molded by the injection molding die according to the first embodiment. FIG. 4 is an explanatory diagram for explaining the production of the injection molding die according to the first embodiment. FIG. 5 is a schematic view showing a processing method in the present mold processing process. FIG. 6 is an explanatory diagram for explaining the production of the injection molding die according to the second embodiment. FIG. 7 is an explanatory diagram for explaining the production of the injection molding die according to the third embodiment.

Hereinafter, a method for producing an injection molding die, a molding method using an injection molding die, and an embodiment of the injection molding die according to the present invention will be described in detail. In the following embodiment, a case where a game plate of a pachinko game machine is manufactured will be described as an example, but a method for manufacturing an injection molding mold, a molding method using an injection molding mold, and injection molding according to the present invention will be described. The mold is not limited to the molding of the game plate of the pachinko game machine, and can be applied to all molding of resin molded products having a boss or the like to be corrected. Molding methods using molds and injection molding molds are also included.

(First Embodiment)
FIG. 1 shows a flowchart of a process of manufacturing by the injection molding die according to the first embodiment. 2 and 3 show a game plate 10 as an example of a molded product manufactured by the injection molding die according to the first embodiment. Hereinafter, a method for producing an injection molding die and a molding method using this injection molding die will be described at the same time, and these explanations include a description of the injection molding die and a description of the molded product. Replace with.

The method for producing an injection molding die according to the present invention mainly includes a temporary mold processing step, a temporary molding step, a temporary molded product measuring step, and a present mold processing step as shown in FIG.

(Temporary mold processing process)
First, based on the design data of the game plate 10 shown in FIG. 2, which is scheduled to be produced as a mass-produced molded product, processing data considering the molding shrinkage rate of the game plate 10 is produced. When producing the processing data of the game board 10 according to the first embodiment, processing data different from some design data is produced as follows. First, as shown in FIG. 3, any position of the assembly boss 12b or the positioning boss 12c provided on the game board 10 is set as a reference point. The reference point can be set to any part. For example, it may be the center of the winning opening 15 of the game board 10. Preferably, as shown in FIG. 3, any one of the assembly bosses 12b may be used as a reference point. In the present embodiment, the upper left assembly boss 12b is used as the reference point as the reference boss 12a. Then, with respect to the reference boss 12a, such as a boss or rib (not shown) other than the reference boss 12a, such as an assembly boss 12b for assembling other parts, a positioning boss 12c, or a rib. The bosses and the like that require the accuracy of all relative positions (hereinafter referred to as "correction target bosses and the like 12d") are smaller than the size of the assembly boss 12b and the ribs originally set as the game board 10. Create processing data so that it is molded. Here, the assembling boss is a boss that is assembled with the assembling part by a screw, and the positioning boss or the rib is an assembling part so that it can be easily arranged at a predetermined position when assembling the assembling part. A boss or rib that supports the outer circumference of the. For example, as shown in FIG. 3, the size of the assembly boss 12b on the design data is the boss outer diameter φ12 and the inner diameter φ8, but the machining data in the temporary mold machining process is as shown in FIG. The outer diameter is set to φ8 and the inner diameter is set to φ4, and it is designed so that a temporary boss with an outer diameter of φ8 and an inner diameter of φ4 is produced when molded with a temporary mold manufactured in the temporary mold processing process. .. The sizes of the outer diameter and the inner diameter are merely examples, and may be set to smaller diameters. The inner diameter is provided to determine the center of the pin in the process of measuring the temporarily molded product, which will be described later. Therefore, it does not necessarily have to be the inner diameter, and it suffices if it can be molded so that the center of the temporary boss can be easily recognized. For example, a conical protrusion may be formed at the center of the temporary boss, or a cross mark may be engraved on the surface of the temporary boss so that the center can be recognized. In the case of positioning ribs, the ribs are set to be thinner than the original ribs. For the calculation of the product shrinkage rate, various conventionally proposed methods can be adopted. For example, it may be performed by CAE simulation as shown in the conventional example.

Using the processing data produced in this way, a temporary mold is produced by machining or the like. In the temporary mold produced in this way, the outer shape, the parts other than the correction target boss 12d such as the reference boss 12a are processed based on the design data, and only the correction target boss 12d is smaller than the design data. It becomes a molding die that can be manufactured by.

(Temporary molding process)
Next, a temporarily molded product of the game plate 10 is produced using the temporary mold described above. At this time, molding conditions such as injection pressure, injection speed, cylinder temperature, mold temperature, and cooling time are set in advance. The molding conditions at this time are not particularly limited, but are not necessarily the molding conditions obtained by trial and error so that the product approaches the design data of the product, and the molding most suitable for mass production in mass production. It is good to set the conditions. That is, the conditions with the shortest molding time and high mass productivity may be set in consideration of the injection pressure, the injection speed, the cylinder temperature, the mold temperature, the cooling time, and the like. As shown in FIG. 4, the game plate 10 which is a temporarily molded product thus molded is molded based on the design data except for the outer shape, the reference boss and other parts other than the correction target boss 12d, and the correction target boss and the like are formed. Only 12d is manufactured in a smaller form (thin boss, etc.) than the design data. Therefore, the forms other than 12d, such as the correction target boss, are the same as the forms at the time of mass production.

(Temporarily molded product measurement process)
Next, the positional deviation is measured by comparing the relative positional relationship between the reference boss 12a of the temporarily formed game plate 10 and the correction target boss 12d and the design data. At this time, by measuring the relative position between the center of the reference boss 12a and the center of the correction target boss or the like 12d, the positional deviation with respect to the original design data can be accurately measured. For example, in the temporarily molded game plate 10 shown in FIG. 4, the correction target boss or the like 12b'should be at the position of arrow A on the design data, but the actual molded product is at the position of 12b'. If there is, the error becomes a misalignment. That is, the α position is shifted in the vertical direction and the β position is shifted in the horizontal direction. It should be noted that the actual molded product does not have such a large misalignment and has a smaller misalignment, but for convenience of explanation, the misalignment is exaggeratedly displayed in FIG. The misalignment may be measured in two dimensions, vertically and horizontally, as in the present embodiment, depending on the required accuracy, or the distance to the reference boss in one dimension (pitch only). You may measure the misalignment of.

(This mold processing process)
Next, based on the value of the positional deviation between the reference boss 12a and the correction target boss 12d obtained in the temporarily molded product measurement step, processing data in which the positions of the assembly bosses 12b and the like are corrected is produced. That is, if it is 12b', the processing data is created by shifting the center position by the value of the distance between α and β. As the processing data at this time, the processing data of the original boss outer diameter φ12, the inner diameter φ8 size, and the original rib thickness is created. Based on the processing data corrected in this way, the temporary mold is processed again by machining or the like to prepare the main mold. The processing of the injection molding die in this step is mainly the processing of the 12d portion such as the correction target boss. The actual misalignment is at most several mm or less, and most of them are 1.0 mm or less. Therefore, even if the center position of 12d such as the boss to be corrected of the mold is originally corrected and processed. As shown in FIG. 5, since the boss hole of the core mold 21 of the 12d mold such as the correction target boss processed by temporary processing and the sleeve hole 22 into which the sleeve pin 25 is inserted are made small in diameter, the alternate long and short dash line is formed. Even when the center position is shifted (corrected) as in the above, it is often sufficient to only widen the boss hole and the sleeve hole 22. Therefore, it is possible to reduce large corrections such as thickening correction in the mold processing in the main processing process, and it is possible to reduce the work in the main processing process. Further, as for the inner diameter, the core pin 23 having the original inner diameter may be attached to the modified sleeve hole 22. Of course, it is not excluded that the boss hole such as the correction target boss and the sleeve hole 22 itself are reprocessed when the position is largely displaced. In this way, the main mold for injection molding for mass production is completed. In the injection molding die produced in this way, only the correction target boss 12d and the like are position-corrected. Therefore, regarding the design data, the pitch between the reference boss 12a and the correction target boss 12d and the reference boss 12a and the correction target boss are corrected. The mold is manufactured at a ratio different from the pitch with the portion other than the above (for example, the outer peripheral rib 18).

(Mass production molding process)
Using the injection molding die thus produced, the game plate 10 as a mass-produced molded product is produced. As the injection molding conditions at this time, the conditions set in the temporary molding process are used. By setting the injection conditions such as injection pressure, injection speed, cylinder temperature, mold temperature, cooling time, etc. to the same or near the same as the temporary molding process, the misalignment under those conditions is corrected. Therefore, it is possible to mold a molded product having an accurate relative position with respect to the reference boss 12a such as the correction target boss. Generally, it is preferable to perform molding under conditions in which each injection condition such as injection pressure, injection speed, cylinder temperature, mold temperature, cooling time, etc. is within ± 5% of the injection conditions in the temporary processing step.

The game plate 10 thus produced produces a molded product in which the positions of the assembling boss 12b, the positioning boss 12c, or the ribs, which require relatively high accuracy, are close to the design data in position with respect to the reference boss 12a. can do. That is, the positional deviation between the reference boss 12a and the correction target boss 12d is produced in a positional relationship that more accurately reflects the design data with respect to the positional deviation from other parts. Therefore, it is possible to manufacture the game board 10 to which the assembled product or the like can be attached at a more accurate position.

In particular, in the case of a molded product such as the game plate 10 having a large opening 19 in which a symbol variation display device is attached in the center as shown in FIG. 2 or having a plate thickness different depending on the location, an assembly boss It was extremely difficult to fabricate the mold so that the positions of 12b, the positioning boss 12c, or the ribs would be the original positions only by calculating the product shrinkage rate. According to the manufacturing method and the molded product using this injection molding mold, the parts other than 12d such as the boss to be corrected use a mold having the same shape as the mass production mold, and the molding conditions at the time of mass production. Since the misalignment of the correction target boss or the like 12d is corrected based on the product molded in 1 above, the position of the correction target boss or the like 12d with respect to the reference boss 12a can be made into an extremely accurate molded product.

Further, at the time of mass production molding, since the molding conditions are set in advance, it is not necessary to set the molding conditions, the number of trial shots can be reduced, and the mass production process can be started immediately. Further, since the molding conditions are set to be suitable for mass production, it is possible to suppress the occurrence of defective products as compared with the conventional ones.

(Second Embodiment)
A method for producing the injection molding die according to the second embodiment is shown in FIG. The method for producing an injection molding die according to the second embodiment has a different range of 12d such as a boss to be corrected from the first embodiment. In the first embodiment, all the assembling bosses 12b or the positioning bosses 12c other than the reference boss 12a are set as the correction target bosses and the like 12d in the mold main processing step, but all the bosses and the like 12d need to be processed. For example, as shown in FIG. 6, the assembly boss is located at a position relatively close to the reference boss 12a and has a small influence on the assembly (for example, within a 10 cm range). For the 12b or the positioning boss 12c (the range circled in FIG. 6), the mold may be manufactured according to the design data in the mold temporary processing step and may not be corrected from the beginning. The assembly boss or the like to be corrected can be arbitrarily set in consideration of other assembly parts and other influences.

(Third Embodiment)
A method for manufacturing an injection molding die according to a third embodiment is shown in FIG. The method for producing an injection molding die according to the third embodiment is characterized by a method for specifying 12d such as a boss to be corrected. Specifically, as shown in circles B, C, and D in FIG. 7, a plurality of assembly bosses 12b and positioning bosses 12c other than the reference point are divided into groups of those in the vicinity. .. Then, any one or more assembly bosses 12b or positioning bosses 12c are specified as correction target bosses 12d from each of these groups. Preferably, the assembling boss 12b or the positioning boss 12c near the center of each group may be the correction target boss or the like 12d. Then, the assembling boss 12b and the positioning boss 12c (such as the boss indicated by the dotted line in FIG. 7) other than those selected for the correction target boss 12d are provisionally prepared without producing processing data in the temporary mold processing step. Do not process into a mold. Therefore, in the temporary molding, the assembly boss 12b and the positioning boss 12c other than those selected for the correction target boss 12d are not formed.

Then, in the temporarily molded product measuring step, the positional deviation between the reference boss 12a of the temporarily molded molded product and the respective correction target bosses 12d is measured, and the correction target bosses, etc. 12d are added to the processing data in the main mold processing process. Reflect the misalignment of. On the other hand, the assembly boss 12b or the positioning boss 12c other than the one selected as the correction target boss 12d is found to be misaligned between the reference boss 12a and the correction target boss 12d. Machining data is created with reference to the positional deviation of the target boss 12d. Since the assembly boss 12b or the positioning boss 12c in each group is at a short distance, the misalignment in each group is almost the same as the misalignment of the correction target boss 12d, so that it is almost accurate. It becomes possible to process in various positions.

By setting the correction target bosses and the like 12d for each group in this way, the number of correction target bosses or ribs to be measured can be reduced, so that the measurement work in the temporarily molded product measurement process can be reduced. can. Further, by not processing the bosses other than 12d such as the correction target boss in the temporary mold processing process, the mold processing work in the temporary mold processing process can be reduced.

In the machining of the assembling boss 12b or the positioning boss 12c other than those selected for the correction positive target boss, etc. 12d in this mold machining process, instead of creating machining data based on the reference boss 12a, Processing data may be created based on 12d such as the correction target boss of each group. Since the position of each correction target boss or the like 12d is corrected, it is possible to process the correction target boss or the like into an accurate position based on the correction target boss or the like 12d.

As shown in the above-described embodiment, it can be used for molding a game board of a game machine that uses a game ball as a game medium.

10 ... Game board, 12a ... Reference boss, 12b ... Assembly boss, 12c ... Positioning boss, 12d ... Correction target boss, etc. 15 ... Winning opening, 18 ... Outer rib, 19 ... Opening, 21 ... Core type, 22 ... Sleeve hole, 23 ... Core pin, 25 ... Sleeve pin

Claims (5)

A method for producing an injection molding die, which comprises the following steps (1) to (4) in a method for producing an injection molding die for molding a molded product having an assembly or positioning boss. ..
(1) Based on the design data of the molded product, an arbitrary reference point is determined, and at least a part of the boss or rib used for assembly or positioning (hereinafter referred to as "correction target boss, etc.") is designed. Temporary mold processing step of producing a temporary mold processed so as to be produced in a form smaller than the data (2) Using the temporary mold, a predetermined injection pressure, injection speed, cylinder temperature, mold temperature, preformed to the positional relationship of the provisional molding step (3) the reference point of the temporary molded article for molding the temporary molded product by molding conditions between cooling and the correction target boss such measures, measures the positional deviation with respect to the design data Product measurement step (4) This mold processing step of correcting the position of the correction target boss or the like based on the measurement result of the positional deviation by the temporarily molded product measurement step and processing the correction target boss or the like. The method for manufacturing an injection molding die according to claim 1, wherein the reference point is an assembly boss or a positioning boss. In the temporary mold processing process
The bosses or ribs used for assembly or positioning other than the reference point are divided into a plurality of groups, and one or two or more of the bosses or ribs in each group are designated as correction target bosses or the like. The method for producing an injection molding die according to claim 1 or 2. The method for producing an injection molding die according to claim 3, wherein in the temporary mold processing step, the bosses or ribs of each group other than the correction target bosses and the like are not processed. In the main mold processing process, the bosses or ribs of each group not processed in the temporary mold processing process other than the correction target bosses and the like are processed based on the reference bosses or the correction target bosses of each group. The method for producing an injection molding die according to claim 4, wherein the mold is manufactured.

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