JP2018165007A - Resin molding die - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin molding die capable of accurately molding a columnar member over an entire extending direction without sinking in the columnar member in a part of the extending direction of the columnar member when forming the columnar member as a resin molded product.SOLUTION: A resin molding die 1 is provided with a molding part 40 having a plurality of layer parts laminated in a vertical direction, and the plurality of layer parts are composed of a first layer part 41, a second layer part 42 laminated on an upper side of the first layer part 41, and a third layer part 43 laminated on an upper side of the second layer part 42. The molding part 40 has a cavity part 44 into which a resin material is poured and the cavity part 44 extends in the vertical direction and is disposed across the first layer part 41, the second layer part 42, and the third layer part 43. A gas permeability of the second layer part 42 is different from a permeability of the first layer part 41 and a permeability of the third layer part 43.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a resin mold.

  A molding die for making a resin molded product is known. For example, Patent Literature 1 describes an insert molding die having a fixed die and a movable die.

JP 2009-66810 A

  When a columnar member is molded as a resin molded product using the molding die as described above, sink marks occur in the columnar member in a part in the extending direction of the columnar member, and the molding accuracy of the columnar member is partially reduced. There was a case.

  In view of the above circumstances, an object of the present invention is to provide a resin molding die that can be accurately molded over the entire direction in which a columnar member extends.

  One aspect of the resin molding die of the present invention includes a molded part having a plurality of layer parts stacked in the vertical direction, and the plurality of layer parts are a first layer part and an upper side of the first layer part. A second layer part laminated on the second layer part, and a third layer part laminated on the upper side of the second layer part, the molding part has a cavity part into which a resin material is poured, and the cavity part is , Extending in the vertical direction, and straddling the first layer portion, the second layer portion, and the third layer portion, the gas permeability of the second layer portion is the transmission of the first layer portion And the transmittance of the third layer portion.

  According to one aspect of the present invention, there is provided a resin molding die that can be accurately molded over the entire extending direction of the columnar member.

FIG. 1 is a cross-sectional view showing a resin mold according to the first embodiment. FIG. 2 is a perspective view showing a forming part of the first embodiment. FIG. 3 is a view of the molded portion of the first embodiment viewed from below. FIG. 4 is a perspective cross-sectional view showing the forming portion of the first embodiment. FIG. 5 is a view showing the forming portion of the first embodiment and is a cross-sectional view taken along the line VV in FIG. FIG. 6 is a perspective cross-sectional view showing the forming part of the first embodiment. FIG. 7 is a cross-sectional view showing a forming part of the second embodiment. FIG. 8 is a perspective view showing a forming part of the second embodiment. FIG. 9 is a perspective cross-sectional view showing a forming part of the second embodiment. FIG. 10 is a view of a part of the molding unit according to the second embodiment as viewed from below.

  The Z-axis direction shown in each figure is a vertical direction Z with the positive side as the upper side and the negative side as the lower side. The X-axis direction shown in each figure is a front-rear direction X orthogonal to the up-down direction Z. The Y-axis direction shown in each drawing is a left-right direction Y orthogonal to both the up-down direction Z and the front-rear direction X. Note that the vertical direction, the front-rear direction, the left-right direction, the upper side, and the lower side are simply names for explaining the relative positional relationship between the parts, and the actual layout relationship is other than the layout relationship indicated by these names. Or the like.

<First Embodiment>
As shown in FIG. 1, the resin molding die 1 of this embodiment is a die for molding a spool valve SV, for example. The spool valve SV has a multistage columnar shape arranged along a central axis J extending in the up-down direction Z. A radial direction centered on the central axis J is simply referred to as “radial direction”, and a circumferential direction centered on the central axis J is simply referred to as “circumferential direction”. The spool valve SV has a first small diameter part SD1, a first large diameter part BD1, a second small diameter part SD2, a second large diameter part BD2, and a third small diameter part SD3 from the lower side to the upper side. In this order.

  The first small diameter portion SD1 is the lower end portion of the spool valve SV. The third small diameter portion SD3 is an upper end portion of the spool valve SV. The outer diameter of the first large diameter portion BD1 and the outer diameter of the second large diameter portion BD2 are larger than the outer diameter of the first small diameter portion SD1, the outer diameter of the second small diameter portion SD2, and the outer diameter of the third small diameter portion SD3. Big and the same.

  The resin molding die 1 has a cavity 1a serving as a mother die having an outer shape of the spool valve SV. The spool valve SV is formed by pouring molten resin into the cavity 1a and cooling it. The resin mold 1 includes a first mold member 10, a second mold member 20, and a third mold member 30.

  The first mold member 10 includes a base 11, a first holding member 12, a molding part 13, a molding part 14, and a plug body 15. That is, the resin molding die 1 includes a base 11, a first holding member 12, a molding part 13, a molding part 14, and a plug body 15. The base 11 has a through hole 11 a that passes through the base 11 in the vertical direction Z along the central axis J. The through hole 11a is connected to the lower end of the cavity 1a.

  The first holding member 12 has a first holding hole 12 a that penetrates the first holding member 12 in the vertical direction Z. The molding part 13 is held inside the first holding hole 12a. The forming part 13 is a part for forming the first small diameter part SD1. The molding part 14 is held inside the first holding hole 12 a on the upper side of the molding part 13. The molding part 14 is a part for molding the first large-diameter part BD1. The plug body 15 has a cylindrical shape extending in the vertical direction Z. The plug 15 is fitted into the through hole 11a and closes the through hole 11a. The upper end surface of the plug 15 constitutes the bottom surface of the cavity 1a.

  The second mold member 20 is fixed to the upper side of the first mold member 10. Between the vertical direction Z of the 1st metal mold member 10 and the 2nd metal mold member 20, the insertion hole 1c which penetrates the resin mold 1 in the horizontal direction Y through the central axis J is provided. The second mold member 20 includes a second holding member 21, a molding part 40, and a molding part 22. That is, the resin molding die 1 includes a second holding member 21, a molding part 40, and a molding part 22.

  The second holding member 21 has a second holding hole 21 a that penetrates the second holding member 21 in the vertical direction Z. The molding part 40 is held inside the second holding hole 21a. The forming part 40 is a part for forming the second large diameter part BD2. The molding part 22 is held inside the second holding hole 21 a on the upper side of the molding part 40. The forming part 22 is a part for forming the third small diameter part SD3. The molding part 22 has a resin injection hole 1b that opens upward. The resin injection hole 1b is connected to the upper end of the cavity 1a. A resin material is poured into the cavity 1a from the resin injection hole 1b. The inner diameter of the resin injection hole 1b decreases from the upper side to the lower side.

  The third mold member 30 has a pair of molding portions 31 extending in the left-right direction Y. That is, the resin molding die 1 has a pair of molding parts 31. A pair of shaping | molding part 31 mutually arrange | positions a clearance gap in the left-right direction Y mutually. A pair of shaping | molding part 31 is inserted from the both sides of the left-right direction Y of the insertion hole 1c, respectively. The gap in the left-right direction Y of the pair of molding parts 31 is a part for molding the second small diameter part SD2 in the cavity 1a.

  The molding part 31 has a groove part 32 that is recessed downward from the upper surface of the molding part 31. The groove 32 extends in the left-right direction Y. The radially inner end portion of the groove portion 32 is located on the radially outer side of a cavity portion 44 described later of the molded portion 40. On the upper side of the radially inner end portion of the groove portion 32, the molding portion 40 is disposed. The radially outer end portion of the groove portion 32 is located on the radially outer side of the first mold member 10 and the second mold member 20 and is exposed to the outside of the resin mold 1.

  As shown in FIGS. 2 to 6, the molding part 40 includes a molding part main body 40a and a flange part 40b. The molded part main body 40a has a substantially rectangular parallelepiped shape. As shown in FIG. 3, the shape of the molded part main body 40 a viewed along the vertical direction Z is a rounded rectangular shape that is long in the left-right direction Y. As shown in FIGS. 2 and 4, the flange portion 40 b protrudes from the upper end portion of the molded portion main body 40 a to both sides in the left-right direction Y. The collar portion 40b has a rectangular parallelepiped shape that is long in the front-rear direction X.

  As shown in FIGS. 2 to 5, the molding portion 40 has a hollow portion 44 that penetrates the molding portion main body 40 a in the vertical direction Z. The cavity 44 is disposed along the central axis J. The inner surface of the cavity 44 is cylindrical with the central axis J as the center. In the present embodiment, the dimension of the cavity 44 in the direction orthogonal to the vertical direction Z, that is, the inner diameter of the cavity 44 is uniform along the vertical direction Z. In the present specification, “the dimensions are uniform” includes that the dimensions are substantially the same in addition to the dimensions being exactly the same. The cavity part 44 is a part for molding the second large diameter part BD2 in the cavity 1a. That is, the resin material is poured into the cavity 44.

  As shown in FIGS. 3 and 5, the molding portion 40 has a groove portion 40 c. The groove portion 40 c is recessed upward from the lower surface of the molding portion 40. The groove portion 40 c extends in the left-right direction Y from one end to the other end in the left-right direction Y of the molding portion 40. As shown in FIG. 3, the groove 40 c is provided at the center in the front-rear direction X on the lower surface of the molded part 40. The shape seen from the lower side of the groove part 40c is a rectangular shape long in the left-right direction Y. The dimension of the groove part 40 c in the front-rear direction X is smaller than the inner diameter of the cavity part 44. The groove portion 40 c is divided into both sides in the left-right direction Y by the hollow portion 44.

  As shown in FIG. 5, the molding portion 40 has a plurality of layer portions that are stacked in the vertical direction Z. The plurality of layer parts include a first layer part 41, a second layer part 42, and a third layer part 43. In the present embodiment, the molding part 40 is configured by laminating a first layer part 41, a second layer part 42, and a third layer part 43 in the vertical direction Z. The first layer part 41 is a layer part arranged on the lowermost side. The second layer part 42 is a layer part stacked on the upper side of the first layer part 41. The third layer portion 43 is a layer portion that is stacked on the upper side of the second layer portion 42. The third layer portion 43 is a layer portion disposed on the uppermost side.

  The first layer portion 41 has a first through hole 41 a that penetrates the first layer portion 41 in the vertical direction Z. The second layer portion 42 has a second through hole 42 a that penetrates the second layer portion 42 in the vertical direction Z. The third layer portion 43 has a third through hole 43 a that penetrates the third layer portion 43 in the up-down direction Z. The 1st through-hole 41a, the 2nd through-hole 42a, and the 3rd through-hole 43a are mutually connected, and comprise the cavity part 44 mentioned above. That is, the hollow portion 44 extends in the up-down direction Z and is disposed across the first layer portion 41, the second layer portion 42, and the third layer portion 43.

  The gas permeability of the second layer part 42 is different from the gas permeability of the first layer part 41 and the gas permeability of the third layer part 43. Here, in this specification, “gas permeability” is an index indicating the ease of passage of gas, and is measured, for example, by a leak test. That is, when a leak test is performed on a certain target, the gas permeability is larger as the gas leakage amount is larger, and the gas permeability is smaller as the gas leakage amount is smaller. It does not specifically limit as a leak test, For example, the leak test method by the pressure change prescribed | regulated to JIS2332: 2012 can be used.

  For example, when forming a columnar member extending in the vertical direction Z as a resin molded product using a resin molding die, sink marks occur in the columnar member in a part of the vertical direction Z, and the molding accuracy of the columnar member is partially increased. There was a case of decline. Causes of sink marks in the columnar member in a part in the vertical direction Z include, for example, that air remains in the cavity into which the resin material is poured and a portion that is difficult to be filled with the resin material occurs, There are places where the temperature is different in the vertical direction Z, and a part where the molding shrinkage rate partially increases may be considered.

  On the other hand, according to the present embodiment, the gas permeability of the second layer portion 42 disposed between the first layer portion 41 and the third layer portion 43 in the vertical direction Z is the first layer portion. 41 and the gas permeability of the third layer portion 43 are different. Therefore, in the first layer portion 41 to the third layer portion 43, the gas permeability of the layer portions adjacent in the vertical direction Z is different. Thereby, it is easy to make the gas permeability of each layer part a value that matches the part where the columnar member is prone to sink.

  Specifically, by increasing the gas permeability of the layer part that forms the columnar member to be formed, that is, in the second embodiment, the part where the sink marks are likely to occur in the second large diameter part BD2, the cavity part passes through the inside of the layer part. The air can be extracted from inside 44. Thereby, it is possible to suppress the occurrence of a portion in which the air hardly remains in the hollow portion 44 and the resin portion is not easily filled in the hollow portion 44. Therefore, it is possible to suppress the occurrence of sink marks partially in the molded second large diameter portion BD2.

  For example, when increasing the gas permeability of the layer part, it is conceivable to increase the porosity by making the material of the layer part porous. The higher the porosity, the lower the thermal conductivity of the material. When the thermal conductivity is small, the temperature of the layer portion during molding tends to be low, and the molding shrinkage rate of the resin molded product can be reduced. Thereby, by increasing the gas permeability of the layer portion that forms the portion where the sink is likely to occur in the second large diameter portion BD2, the thermal conductivity of the layer portion can be reduced, and the portion formed by the layer portion can be reduced. Mold shrinkage can be reduced. Therefore, it is possible to suppress the molding shrinkage rate from being partially increased in the second large diameter portion BD2 to be molded, and it is possible to suppress the occurrence of partial sinking in the second large diameter portion BD2.

  As described above, according to the present embodiment, it is possible to suppress the occurrence of sink marks in a part of the columnar member to be molded in the vertical direction Z. Thereby, the resin molding die 1 which can be shape | molded accurately over the columnar member, ie, the whole direction extended in 2nd large diameter part BD2, is obtained.

  In the present embodiment, the gas permeability of the second layer part 42 is larger than the gas permeability of the first layer part 41 and the gas permeability of the third layer part 43. For example, a portion where sink marks are likely to occur in a columnar member to be molded tends to be an intermediate portion between the upper end portion and the lower end portion of the columnar member. Therefore, it is possible to suppress the occurrence of sink marks in the intermediate portion of the columnar member by increasing the gas permeability of the second layer portion 42. Therefore, the second large-diameter portion BD2 can be molded more accurately over the entire vertical direction Z. The gas permeability of the first layer part 41 and the gas permeability of the third layer part 43 are, for example, the same.

  The dimension H2 in the vertical direction Z of the second layer part 42 is smaller than the dimension H1 in the vertical direction Z of the first layer part 41. The dimension H3 in the vertical direction Z of the third layer part 43 is smaller than the dimension H2 in the vertical direction Z of the second layer part 42. The dimension H <b> 1 in the vertical direction Z of the first layer part 41 is the dimension in the vertical direction Z in the portion of the cavity part 44 that is disposed in the first layer part 41. The dimension H <b> 2 in the vertical direction Z of the second layer part 42 is the dimension in the vertical direction Z at a portion of the cavity part 44 that is disposed in the second layer part 42. The dimension H3 in the up-down direction Z of the third layer part 43 is the dimension in the up-down direction Z of the portion of the cavity part 44 disposed in the third layer part 43. That is, the dimension H1 in the vertical direction Z in the portion disposed in the first layer portion 41 of the cavity portion 44 is larger than the dimension H3 in the vertical direction Z in the portion disposed in the third layer portion 43 of the cavity portion 44. Accordingly, the second layer portion 42 is disposed on the upper side of the center of the vertical direction Z in the molding portion 40.

  Here, it has been found by experiments and the like by the present inventors that the intermediate portion where the sink marks are likely to occur in the columnar member tends to be closer to the upper side than the center in the vertical direction Z. Therefore, by arranging the second layer part 42 having a larger gas permeability than the first layer part 41 and the third layer part 43 closer to the upper side, it is possible to suppress the occurrence of sink marks more effectively. Therefore, the second large-diameter portion BD2 can be molded more accurately over the entire vertical direction Z.

  In addition, for example, when the columnar member to be molded is cylindrical, a portion where sink marks are likely to be an intermediate portion in the vertical direction Z, and in particular, tends to be closer to the upper side than the center. Therefore, when the inner surface of the cavity 44 is cylindrical in order to form the columnar second large-diameter portion BD2 as in the present embodiment, the gas permeability of the second layer portion 42 is increased. Therefore, it is easy to suppress sink marks particularly effectively.

  In addition, the second large diameter portion BD2 formed by the forming portion 40 of the present embodiment is a portion that slides in the spool valve SV, and the outer diameter is uniform with accuracy over the entire vertical direction Z. Is required. Therefore, when the inner diameter of the cavity 44 is uniform along the vertical direction Z in order to mold the sliding cylindrical member, the effect of accurately molding the columnar member over the entire vertical direction Z is Is particularly useful.

  In the present embodiment, at least one of the plurality of layer portions has porosity. In the present embodiment, the second layer portion 42 among the first layer portion 41, the second layer portion 42, and the third layer portion 43 has porosity. Thereby, the gas permeability of the second layer portion 42 can be easily and suitably increased. Therefore, it is possible to suppress the occurrence of sink marks.

  In the second layer portion 42, the inner peripheral surface of the second through hole 42 a is exposed in the cavity portion 44. In other words, the second layer portion 42 is a porous portion having porosity and a part of which is exposed in the cavity portion 44. Thereby, the shaping | molding part 40 has a porous part. Here, in this specification, “a part of the layer part is exposed in the cavity part” includes that a part of the layer part constitutes a part of the inner side surface of the cavity part.

  The molding part 40 has a hole 47 that connects the second layer part 42, which is a porous part, and the outside of the molding part 40. For example, if air remains in the cavity 44, sink marks may occur in the resin molded product as described above, and the remaining air is compressed and burned, resulting in gas burning in which a part of the resin molded product is carbonized. May occur. On the other hand, for example, it is conceivable to evacuate the hollow portion by dividing the molding portion and providing an exhaust hole on the divided surface between the divided molding portions. However, in this case, when the resin material to be filled exceeds the dividing surface, the exhaust hole is blocked, and the exhaust in the cavity portion may be insufficient. In addition, the exhaust holes are filled with a resin material, and burrs may occur.

  On the other hand, according to the present embodiment, the air in the cavity 44 is exposed from the part exposed in the cavity 44 of the second layer part 42 that is a porous part, through the hole 47, and the molded part. 40 can be exhausted to the outside. Therefore, by disposing the portion of the porous portion exposed in the hollow portion 44 at a place where sink marks and gas burn are likely to occur, the hollow portion 44 can be sufficiently exhausted during molding. Therefore, it is possible to suppress the air from remaining in the cavity 44 during the molding of the resin molded product, to suppress the occurrence of sink marks in the resin molded product, and to suppress the occurrence of gas burning. Moreover, since the part exposed in the cavity part 44 is a porous part which has porosity, it can suppress that a resin material is filled, and can also suppress that a burr | flash generate | occur | produces in a resin molded product. Further, as described above, since the gas permeability of the second layer portion 42 is relatively high, the hole portion 47 is connected to the second layer portion 42, so that the exhaust in the cavity portion 44 can be more easily performed.

  The hole 47 has a first hole 45 and a second hole 46. The first hole 45 extends in the up-down direction Z. The first hole 45 opens in at least one of the upper surface of the molded portion 40 and the lower surface of the molded portion 40 on the radially outer side of the cavity portion 44. In the present embodiment, the first hole 45 opens on the lower surface of the molding part 40. Thereby, the air that has flowed into the hole 47 from the inside of the cavity 44 via the second layer portion 42 can be discharged from the lower side of the molding portion 40.

  As shown in FIG. 1, in this embodiment, the lower opening of the first hole 45 faces the groove 32. Therefore, the air discharged from the lower opening of the first hole 45 passes through the groove 32 and is discharged to the outside of the resin molding die 1. As described above, when a plurality of molding parts are stacked in the vertical direction Z as in this embodiment, air can be discharged from either side of the molding part 40 in the vertical direction Z. By providing the groove 32 and the like, the air discharged from the molding portion 40 can be easily discharged to the outside of the resin molding die 1.

  As shown in FIG. 5, the first hole 45 is connected to the second layer 42. Therefore, the air that has flowed into the second layer portion 42 from the cavity portion 44 can be directly discharged to the outside of the molding portion 40 through the first hole portion 45. The first hole portion 45 extends linearly downward from the upper end portion of the second layer portion 42 and opens on the lower surface of the molding portion 40. As shown in FIGS. 2 to 4, the lower opening of the first hole 45 opens at the bottom of the groove 40 c. Here, the groove portion 40 c is disposed so as to face the groove portion 32 in the third mold member 30 in the vertical direction Z. Thereby, the air discharged from the lower opening of the first hole portion 45 can be discharged to the outside of the resin molding die 1 through the groove portion 40c and the groove portion 32, and the air is more easily discharged.

  As shown in FIG. 5, the upper end of the first hole 45 has a semicircular shape that protrudes upward. A plurality of first hole portions 45 are provided. As shown in FIG. 3, in the present embodiment, for example, two first hole portions 45 are provided. The two first holes 45 are arranged on both sides in the left-right direction Y with the central axis J interposed therebetween. The cross-sectional shape orthogonal to the vertical direction Z of the first hole 45 is a circular shape. The inner diameter of the first hole 45 is smaller than the inner diameter of the cavity 44.

  As shown in FIGS. 5 and 6, the second hole 46 is connected to the first hole 45. A plurality of second holes 46 are provided along the vertical direction Z. In the present embodiment, three second holes 46 are provided, that is, a second hole 46a, a second hole 46b, and a second hole 46c. The second hole part 46a, the second hole part 46b, and the second hole part 46c are arranged at equal intervals in this order from the lower side to the upper side. Each of the second holes 46 a to 46 c has an annular shape that surrounds the radially outer side of the cavity 44. More specifically, the second holes 46a to 46c are annular with the central axis J as the center. The cross-sectional shape orthogonal to the circumferential direction of the second holes 46a to 46c is a circular shape. The second hole 46a, the second hole 46b, and the second hole 46c overlap in the vertical direction Z.

  The second hole portion 46 a is disposed in the first layer portion 41. The second hole part 46b and the second hole part 46c are arranged in the second layer part 42 which is a porous part. Therefore, the air can be taken into the hole 47 from the entire circumferential direction of the second layer part 42 by the second holes 46b and 46c, and the taken-in air is outside the molding part 40 through the first hole 45. Can be discharged. Therefore, it is easier to evacuate the cavity 44.

  As shown in FIG. 3, the second hole 46 overlaps with the first hole 45 when viewed in the vertical direction Z. As shown in FIGS. 5 and 6, each first hole 45 connects a plurality of second holes 46. Therefore, the air taken into the hole 47 from the plurality of second holes 46 can be discharged to the outside of the molding unit 40 through the first hole 45. Thereby, it is easier to exhaust the inside of the cavity 44.

  In the present embodiment, the molding part 40 is a single member. That is, each layer part is a part of the forming part 40 which is a single member. Therefore, there is no gap between the layer portions adjacent in the vertical direction Z, and the molding accuracy of the second large-diameter portion BD2 to be molded can be improved. The molding unit 40 is manufactured using, for example, a 3D printer. At that time, the gas permeability of each layer part can be varied for each layer part by changing the output of the laser irradiated to the raw material such as metal powder for manufacturing the molded part 40. Specifically, the lower the laser output, the higher the gas permeability of the layer portion. Therefore, when manufacturing the forming part 40 of the present embodiment, after forming the first layer part 41 with a relatively high laser output, the laser output is reduced to form the second layer part 42, and again The third layer portion 43 is formed by increasing the laser output.

  The present invention is not limited to the above-described embodiment, and other configurations can be employed. In the following description, the same configurations as those in the above embodiment may be omitted by appropriately attaching the same reference numerals.

  The molding part 40 is not particularly limited as long as the gas permeability of the second layer part 42 is different from the gas permeability of the first layer part 41 and the gas permeability of the third layer part 43. The gas permeability of the second layer part 42 may be smaller than the gas permeability of the first layer part 41 and the gas permeability of the third layer part 43. Further, the gas permeability of the first layer portion 41 and the gas permeability of the third layer portion 43 may be different from each other. Moreover, the number of each layer part may be four or more. Moreover, the dimension H1, H2, H3 of the up-down direction Z of each layer part is not specifically limited.

  Moreover, each layer part does not need to have porosity. Each layer part may be partially porous. Only a part of the second layer portion 42 where the hollow portion 44 is exposed may be a porous portion. Further, at least one of the first layer part 41 and the third layer part 43 may be a porous part. Further, only a part of at least one of the first layer part 41 and the third layer part 43 may be a porous part. As long as at least a part of the first layer part 41 and the third layer part 43 is a porous part exposed to the cavity part 44, the second layer part 42 may not be a porous part. Moreover, the whole of the first layer part 41, the second layer part 42, and the third layer part 43 may be a porous part. In this case, the entire part constituting the inner surface of the cavity 44 becomes a porous part, and the exhaust in the cavity 44 is easier to perform.

  Moreover, the hole part 47 will not be specifically limited if the porous part and the exterior of the shaping | molding part 40 are connected. The first hole 45 may be opened on the upper surface of the molded part 40, or may be opened on both the lower surface of the molded part 40 and the upper surface of the molded part 40. Further, the number of first holes 45 and the number of second holes 46 are not particularly limited.

  Further, the molding parts 13, 14, 22, 31 other than the molding part 40 may have the same configuration as the molding part 40. Thereby, sink marks and gas burns can be prevented from occurring in the entire spool valve SV, and the entire spool valve SV can be accurately molded.

Second Embodiment
The molding part 240 of this embodiment shown in FIGS. 7 to 10 is a part of a resin molding die for molding the resin molded product M shown in FIG. The molding part 240 is a part for molding the upper end resin part MU of the resin molded product M. The upper end resin part MU has protrusions Ma, Mb, Mc and the like as a plurality of protrusions protruding.

  As shown in FIG. 8, the shape of the molded part 240 viewed along the axial direction is a square shape. The molding part 240 has a through hole 249 that penetrates the molding part 240 in the vertical direction Z. As shown in FIG. 10, the shape of the through-hole 249 viewed along the vertical direction Z is a circular shape centered on the central axis J. As shown in FIG. 7, the molding part 240 has a first layer part 241, a second layer part 242, and a third layer part 243. The second layer part 242 is a porous part, and has a higher gas permeability than the first layer part 241 and the third layer part 243.

  As shown in FIG. 10, in the present embodiment, a plurality of hollow portions 244 are provided on the radially outer side of the through holes 249. The plurality of cavities 244 surround the radially outer side of the through hole 249. The plurality of cavities 244 include a cavity 244a in which the protrusion Ma is formed, a cavity 244b in which the protrusion Mb is formed, and a cavity 244c in which the protrusion Mc is formed.

  As shown in FIG. 7, the cavity 244a extends in the up-down direction Z. The cavity portion 244a includes a molding cavity portion 244d serving as a mother die having an outer shape of the projection portion Ma, and a resin injection hole portion 244e into which a resin material is injected. The molding cavity 244d is a recess that is recessed upward from the lower surface of the first layer portion 241. An upper end portion of the molding cavity portion 244d is disposed in the second layer portion 242. A part of the second layer part 242 is arranged above the molding cavity part 244d. The resin injection hole portion 244e opens in the upper surface of the third layer portion 243. The lower end of the resin injection hole portion 244e opens to the bottom surface of the molding cavity portion 244d that is a recess. A resin material is poured into the molding cavity 244d from the resin injection hole 244e. The inner diameter of the resin injection hole 244e becomes smaller from the upper side to the lower side.

  In the hollow portion 244a, the molding hollow portion 244d is disposed across the first layer portion 241 and the second layer portion 242, and the resin injection hole portion 244e is disposed across the second layer portion 242 and the third layer portion 243. Thus, the first layer portion 241, the second layer portion 242, and the third layer portion 243 are disposed over the first layer portion 241, the second layer portion 242, and the third layer portion 243. Since the upper end portion of the molding cavity portion 244d is disposed in the second layer portion 242, the second layer portion 242 is exposed in the upper end portion of the molding cavity portion 244d. Thereby, the air in the shaping | molding cavity part 244d can be discharged | emitted outside the shaping | molding part 240 through the 2nd layer part 242 which is a porous part.

  A complicated shape having a plurality of protrusions Ma, Mb, Mc such as the upper end resin portion MU has a problem that sink marks are likely to occur during molding. On the other hand, it is conceivable to open an air vent hole at the upper end of the molding cavity 244d for molding the protrusion Ma, but the resin injection hole 244e is connected to the upper end of the molding cavity 244d. Difficult to open holes for use.

  On the other hand, according to the present embodiment, the upper end portion of the molding cavity portion 244d is arranged in the second layer portion 242 that is a porous portion, so that the air vent hole is opened at the upper end portion of the molding cavity portion 244d. The air in the molding cavity 244d can be extracted through the second layer part 242 without causing the air to escape. As a result, the occurrence of sink marks can be suppressed, and the upper end resin portion MU having a complicated shape can be accurately molded.

  The cavity part 244b has a molding cavity part 244f and a resin injection hole part 244g, similarly to the cavity part 244a. Although illustration is omitted, the cavity 244c also has a molded cavity and a resin injection hole, similarly to the cavities 244a and 244b.

  In addition, in FIG. 10, when the shaping | molding part 240 is seen from the lower side, the part which the 2nd layer part 242 exposes is shown by shading. More specifically, the portion shown by hatching in FIG. 10 is the bottom surface of the molding cavity formed by a part of the second layer portion 242.

  As shown in FIG. 8, the hole portion 247 has a third hole portion 248 connected to the second layer portion 242 that is a porous portion. In the present embodiment, the third hole portion 248 is provided in the second layer portion 242. A plurality of third holes 248 are provided. The multiple third holes 248 include a third hole 248a, a third hole 248b, and a third hole 248c. The third holes 248a and 248b open on the side surface in the front-rear direction X of the forming unit 240 in the direction orthogonal to the up-down direction Z. The third hole portion 248c opens on the side surface in the left-right direction Y in the direction orthogonal to the up-down direction Z of the molding portion 240. As a result, the air flowing into the hole 247 from the cavity 244 can be discharged in the direction perpendicular to the vertical direction Z via the third hole 248. Thus, even when other molding parts are stacked in the vertical direction Z of the molding part 240, air can be easily discharged from the hole 247 to the outside of the resin molding die.

  As shown in FIGS. 9 and 10, the third hole 248 a extends in the front-rear direction X. The third hole portion 248a extends from one end portion in the front-rear direction X of the molding portion 240 to the other end portion. Two third holes 248a are provided with the through hole 249 sandwiched in the left-right direction Y. The cross-sectional shape orthogonal to the front-rear direction X of the third hole 248a is a circular shape.

  The third hole portion 248b extends in the front-rear direction X in the radial direction. The third hole portion 248b is disposed at the center in the left-right direction Y of the second layer portion 242 between the two third hole portions 248a. The third hole 248b overlaps the central axis J when viewed along the front-rear direction X. Two third holes 248b are provided with the through hole 249 sandwiched in the front-rear direction X. An end portion on the radially inner side of the third hole portion 248b is disposed away from the through hole 249 radially outward. The cross-sectional shape orthogonal to the front-rear direction X of the third hole 248b is a circular shape. The center of the third hole 248b is located above the center of the third hole 248a.

  The third hole 248c extends in the left-right direction Y in the radial direction. The third hole portion 248 c is disposed at the center in the front-rear direction X in the second layer portion 242. The third hole portion 248c overlaps with the central axis J when viewed along the left-right direction Y. Two third holes 248c are provided with the through hole 249 sandwiched in the left-right direction Y. An end portion on the radially inner side of the third hole portion 248c is disposed away from the through hole 249 radially outward. The cross-sectional shape orthogonal to the left-right direction Y of the third hole 248c is a circular shape. The position in the vertical direction Z at the center of the third hole 248c is the same as the position in the vertical direction Z at the center of the third hole 248b.

  As shown in FIG. 10, a part of the third holes 248 a, 248 b, 248 c is arranged at a position overlapping the cavities 244 a, 244 b, 244 c in the vertical direction Z. Therefore, the air in the cavities 244a, 244b, 244c can easily flow into the third holes 248a, 248b, 248c from the second layer 242. This makes it easier to exhaust the cavities 244a, 244b, and 244c. In the present embodiment, a part of the third holes 248a, 248b, 248c is disposed above the molding cavities 244d, 244f.

  In each embodiment mentioned above, although the hole has the part provided in the 2nd layer part which is a porous part, it is not restricted to this. The hole part should just be connected with a porous part, for example, the structure opened to the surface of a porous part may be sufficient. Specifically, for example, in the molding part 40 of the first embodiment, the hole part may be arranged only in the first layer part 41 and the hole part may be opened on the lower surface of the second layer part 42. Further, each layer portion may be a separate member. Moreover, in each embodiment mentioned above, a hole does not need to be provided.

  Moreover, the resin molded product shape | molded with the resin molding metal mold | die of each embodiment mentioned above is not specifically limited. The shape of the part of the resin molded product molded by the molding part of each embodiment described above is not particularly limited. Moreover, the resin molding die may be composed of only one molding part. Moreover, each said structure can be suitably combined in the range which does not mutually contradict.

  DESCRIPTION OF SYMBOLS 1 ... Resin molding die, 40, 240 ... Molding part, 41, 241 ... 1st layer part, 42, 242 ... 2nd layer part, 43, 243 ... 3rd layer part, 44, 244, 244a, 244b, 244c ... hollow part, 45 ... first hole part, 46, 46a, 46b, 46c ... second hole part, 47, 247 ... hole part, 248, 248a, 248b, 248c ... third hole part, Z ... vertical direction

Claims (11)

A molding part having a plurality of layer parts stacked in the vertical direction,
The plurality of layer portions are
A first layer part;
A second layer portion laminated on the upper side of the first layer portion;
A third layer portion laminated on the upper side of the second layer portion;
Including
The molded part has a hollow part into which a resin material is poured,
The hollow portion extends in the vertical direction, and is disposed across the first layer portion, the second layer portion, and the third layer portion,
The resin molding die in which the gas permeability of the second layer portion is different from the transmittance of the first layer portion and the transmittance of the third layer portion.   2. The resin molding die according to claim 1, wherein the transmittance of the second layer portion is larger than the transmittance of the first layer portion and the transmittance of the third layer portion.   The vertical dimension in a portion arranged in the first layer part of the cavity part is larger than a vertical dimension in a part arranged in the third layer part of the cavity part. Resin mold.   The resin molding die according to claim 2 or 3, wherein the molding part has a hole part that connects the second layer part and the outside of the molding part. The hole has a first hole that opens in at least one of the upper surface of the molded portion and the lower surface of the molded portion;
The resin molding die according to claim 4, wherein the first hole portion is connected to the second layer portion. The hole has a second hole connected to the first hole,
The resin molding die according to claim 5, wherein the second hole portion is an annular shape that is disposed in the second layer portion and surrounds a radially outer side of the cavity portion. The hole has a third hole connected to the second layer,
The resin molding die according to any one of claims 4 to 6, wherein the third hole portion opens on a side surface in a direction orthogonal to the vertical direction of the molding portion.   The resin molding die according to any one of claims 1 to 7, wherein at least one of the layer portions has porosity.   The resin molding die according to any one of claims 1 to 8, wherein the molding part is a single member.   The resin molding die according to any one of claims 1 to 9, wherein an inner surface of the hollow portion has a cylindrical shape extending in a vertical direction.   The dimension of the direction orthogonal to the up-down direction of the said cavity part is a resin molding die as described in any one of Claim 1 to 10 uniform along an up-down direction.

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