JP3156838B2 - Injection mold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding die in which a first runner and a second runner are provided in a pair of a fixed die and a movable die. ,
In particular, it is paired like a main body and a lid , and has a large volume or
The present invention relates to an injection molding die suitable for molding molded articles having different capacities and shapes or for molding hollow molded articles.

[0002]

2. Description of the Related Art An injection molding method for obtaining a molded product by injecting a molten resin into a cavity of a mold to obtain a molded product is conventionally known, and products of various shapes can be obtained by this molding method.
In particular, this molding method is suitable for mass production of one kind, for example, mass production of containers in the case of containers, and is molded in large quantities by this molding method. By the way, recently, there has been a shift from the mass production method as described above to a small-quantity production of a plurality of articles, for example, a molding method for molding a product such as a main body and a lid, and a main body and a handle. When molding the main body and the lid in this way, the main body can be molded with one mold and the lid can be molded with another mold. However, problems such as increased production efficiency, reduced production cost, increased installation space, and the like arise. Therefore, it is desirable to mold two types of molded products with a single-sided mold.

On the other hand, as a method for producing a synthetic resin hollow molded article, a production method using an injection molding machine is known. When a hollow molded product is manufactured by an injection molding machine, the hollow molded product is molded as a half semi-hollow molded product or a divided body in the primary molding, and the divided surface, that is, the flange portion is abutted in the secondary molding, and The molten resin is injected and welded to the butted portions to produce one hollow molded product. Japanese Patent Application Laid-Open No. 62-873 describes this injection molding method.
As shown in No. 15, a mold composed of a fixed mold, a slide mold and the like is used. In these molds, a pair of primary molding cavities for molding a half semi-hollow molded product by primary molding, and a flange portion where the half semi-hollow molded product abuts in the secondary molding. Is formed.
The slide mold is provided with a first sub sprue communicating with the primary molding cavity and a second sub sprue communicating with the secondary molding cavity. Therefore, when the mold is clamped and the molten resin is injected from the sprue of the fixed mold through the first sub-sprue of the slide mold into the cavities for primary molding, a pair of semi-hollow molded articles are molded by these cavities. The movable platen is opened, the slide mold is slid, the flanges of the semi-hollow molded product are abutted, and the mold is clamped to move the sprue of the fixed mold to the secondary molding cavity via the second sub-sprue of the slide mold. Upon injection, the semi-hollow molded article is joined at the flange portion to form a hollow molded article. By opening the movable metal plate and projecting the ejector pins, a hollow molded product is obtained.

[0004]

As described above, when two types of molded products are molded using a single-sided mold, production efficiency and the like can be increased. Different filling times can cause problems. That is, when the injection is performed under the condition to obtain the small volume product, the cavity for obtaining the large volume product is insufficiently filled. On the other hand, when the injection is performed under the condition to obtain the large volume or the product, the cavity that obtains the small volume product is excessive. Filling. Attempts have been made to solve the above problem by increasing the size of the gate leading to the cavity with a large volume and decreasing the gate of the cavity with a small size. There is a limit in the size of the gate and molding is not possible in practice. Such a problem is divided into a primary molding and a secondary molding, and when a product having a large volume is molded by the primary molding and a smaller product is molded by the secondary molding, there is a difference in volume between the molds on one surface. It is thought that the product can be molded, but a switching device for switching from the primary molding to the secondary molding has not yet been proposed.
In fact, products with a large capacity difference in the surface mold are not molded.

When a slide mold is used in addition to a fixed mold, a hollow molded product can be manufactured by an injection molding machine. Therefore, there is an advantage that the production process of the hollow molded product can be automated and mass-produced. In addition, since it is formed by injection molding, it has a feature that a hollow molded article having a complicated shape can be manufactured. However, when a hollow molded article is manufactured by the injection molding method, a secondary molding is required in addition to the primary molding. In addition to the first sub-sprue connected to the primary molding cavity, the slide mold has a secondary molding. Since the second sub-sprue communicating with the next molding cavity must be separately provided, the structure becomes complicated, and even if hot, maintenance of these sub-sprues becomes complicated. Therefore, the present invention provides volume and shape by primary molding and secondary molding.
Aims different moldings kills with easily molded in a mold of one side, to provide an injection mold of the like.

[0006]

The object of the present invention is to achieve the above object by providing in a mold a runner switching means capable of freely switching between a runner for primary molding and a runner for secondary molding. It is assumed that. That is, in order to achieve the above object, the invention according to claim 1 includes a first mold and a second mold each including a fixed mold and a movable mold.
A runner, a second runner, a plurality of cavities communicating with these runners and having different shapes or volumes , and runner switching means for switching the runners. When the runner switching means is switched to the first position, the main sprue connected to the injection nozzle communicates with the first runner. When the runner switching means is switched to the second position, the main sprue communicates with the second runner. The switching order of the switching means depends on the shape of the cavity.
Alternatively, it is configured to be determined by the volume . According to a second aspect of the present invention, the first or second runner of the first aspect communicates with a plurality of sub-spurs, and a third aspect of the present invention provides that the movable mold of the first or second aspect is fixed. A moving mold that slides or rotates with respect to a mold, wherein a first runner is a runner for primary molding for molding a primary molded product, and a second runner is for integrating the primary molded product. 5. A runner for secondary molding of
According to the invention described above, the runner switching means according to any one of claims 1 to 3 has a valve body slidably driven in a bore of a fixed plate, and the valve body has a lower surface. First and second openings
When the valve body is in the first position, the main sprue connected to the injection nozzle communicates with the first runner through the first resin path, and when driven to the second position, It is configured to communicate with the second runner via the second resin path.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described. As shown in FIG. 1A, the mold according to the present embodiment also includes a fixed mold 10 attached to the fixed platen 1 and a movable mold that forms a pair with the fixed mold 10. 20. The fixed platen 1 is provided with a well-known sprue 2 and a runner switching device 3 described in detail later. The fixed mold 10 and the movable mold 20 have first and second cavities 21 and 22 formed therein.
Ejector rods 26 and 27 are provided on the zero side corresponding to the first and second cavities 21 and 22, respectively. The ends of these ejector rods 26 and 27 are attached to an ejector plate 28 as is well known.

The parting surface of the fixed mold 10 is shown in FIG.
(B), the first runner 11 and the second runner 12 are formed in the vertical direction in the figure. Then, the first runner 11 communicates with the first cavity 21 via the sub sprue 13 of the fixed mold 10. The second runner 12 communicates with the second cavity 22 via the sub sprue 14 of the fixed mold 10. The second runner 12 is curved in an arc shape, and a portion communicating with the sub sprue 14 at the tip is in a paired relationship with the first runner 11 as shown in the drawing. Therefore, forces are balanced at the time of mold clamping, injection, and the like.

The first cavity 21 is formed by the concave portion 15 of the fixed mold 10 and the core 23 of the movable mold 20. The second cavity 22 is formed by the parting surface of the fixed mold 10 and the recess 24 of the movable mold 20. With these first and second cavities 21 and 22, molded products having different shapes and volumes such as a main body and a lid, a main body and a handle, and the like can be molded. An example is shown in which the box body is formed by the large first cavity 21 and the lid that closes the opening of the box body is formed by the second cavity 22 having a smaller volume.

The first and second runners 11 and 12 described above include:
At a substantially middle portion thereof, it communicates with the sprue 2 of the fixed mold 1 via a bore 4. A runner switching device 3 is provided in the vicinity of the communication. The runner switching device 3 includes, in the fixed platen 1, a cylindrical bore 4 having a semicircular cross section, which is opened perpendicularly to the plane of FIG.
1 and a driving device, such as an air cylinder unit A, for slidingly driving the valve body 5 in the left-right direction in FIG.

As shown in the perspective view of FIG. 2A, the valve element 5 has a shape obtained by dividing a cylinder into two pieces in the axial direction. The lower surface 6 slides in contact with the parting surface of the fixed mold 10. On the lower surface 6 of the valve element 5, first and second resin paths 7, 8 formed by cutting the valve element 5 to a predetermined depth in one direction and in the opposite direction are formed at predetermined intervals. And the first resin path 7
Is provided with a first through hole 7 '. From the second resin path 8, a concave groove 9 having the same depth in the axial direction extends toward the first resin path 7, and a second through hole 8 ′ is formed at an end of the concave groove 9. I have. Therefore, when the valve body 5 is driven to the first position shown in FIGS. 2B and 2C by the piston cylinder unit A, the sprue 2 of the fixed platen 1 is aligned with the first through hole 7 '. The first through hole 7 ′ communicates with the first runner 11 via the first resin path 7. On the other hand, the valve element 5
Is driven to the second position, as shown in FIGS. 2D and 2E, the sprue 2 communicates with the second through hole 8 ′,
The second runner 12 is formed via the concave groove 9 and the second resin path 8.
Communicate with As described above, the valve element 5 has a shape obtained by dividing the cylinder into two pieces in the axial direction, and the first and second resin paths 7 and 8 are open on the lower surface side. be able to.

Next, a molding method using the dies 10 and 20 will be described. For example, an injection machine equipped with a two-condition controller measures a resin material to be injected into the first cavity 21 having a large volume. Then, the valve element 5 is replaced by (b) in FIG.
Drive to the position shown in (c). Then, the sprue 2 of the fixed plate 1 is connected to the first cavity 8 ′ of the valve element 5, the first resin path 7, the first runner 11 of the fixed mold 10, and the first cavity 21 via the sub sprue 13. Communicate with Therefore, the molten resin is injected from the nozzle N into the first cavity 21 which is clamped at a predetermined pressure. The first cavity 21 is filled with the molten resin, and the box body H is formed. The state after the injection is completed is shown in FIG.

After the injection is completed, the resin material to be injected into the second cavity 22 having a small volume is measured. The valve body 5 is moved by the air cylinder unit A, as shown in FIG.
Drive to the second position shown in (e). Then, the sprue 2 of the fixed plate 1 is moved to the second through hole 8 ′ of the valve body 5, the second resin path 8, and the second runner 1 of the fixed mold 10.
2. It communicates with the second cavity 22 through the sub sprue 14. Therefore, the molten resin is similarly injected from the nozzle N at a set predetermined pressure. The molten resin is filled in the second cavity 22, and the lid F is formed as shown in FIG.

When the molten resin in the first and second cavities 21 and 22 is solidified, the movable die 20 is opened by the movable platen 29, and the box body H and the lid F are ejected by the ejector rods 26 and 27. Take out the molded products H and F, and move the movable mold 2
The resin material to be injected into the first cavity 21 before the mold 0 is clamped to the fixed mold 1 is measured. Hereinafter, molding is performed in the same manner.

According to the present embodiment, various effects can be obtained. For example, since the runner switching device 3 is provided,
The gate can be selected to have a size corresponding to the first and second cavities 21 and 22. Further, since an injection machine equipped with a two-condition controller is used, defects such as short shots and burrs occur in the molded product. There is no such thing. In addition, since the first cavity 21 having a large volume, which takes time to cool and solidify, is filled first, the molding efficiency can be improved. Furthermore, since the weighing and injection are performed in two steps, the molded products H and F having a large capacity can be obtained even with a small-capacity injection machine.

The present invention can be implemented in various forms without being limited to the above embodiment. For example, in the above embodiment, one box body H and one lid F are formed, but a plurality of sub-runners are branched from the first and second runners 11 and 12 to form a plurality of box bodies. It is clear that H and lid F can be molded simultaneously. In addition, in the above-mentioned molding example, the measurement is performed twice by using an injection machine equipped with a two-condition controller. However, the measurement can be performed once and the injection can be performed twice. In the above embodiment, it is simply assumed that the time required for cooling and solidification is longer in the first cavity 21 having a large volume, but the time required for cooling and solidifying differs depending on the shape of the molded product. Therefore, upon implementation, it is desirable to determine the injection order based on the shapes and volumes of the first and second cavities 21 and 22.

Next, a second embodiment of the present invention will be described with respect to a mold for molding a hollow molded article and a molding method using the mold. As shown in FIG. 4A, the mold according to the present embodiment includes a fixed platen 30 located on the left side in the figure, a fixed mold 50 attached to the fixed platen 30, and the like. First, which is divided into minutes and is slidably driven in the vertical direction in the figure;
It is roughly composed of two slide dies 60, 60 ', and a movable plate 67 for driving these slide dies 60, 60' in the mold opening direction.

A sprue 32 is provided at a substantially central axis of the fixed board 30 so as to cross the fixed board 30 as is well known in the art. In addition, the fixed platen 30 includes (b) in FIG.
As shown in FIG. 3, first and second runners 33 and 34 are formed to extend symmetrically in the figure in a vertical direction with the sprue 32 as a center. Moreover,
A sprue 32 is provided on the fixed platen 30 with the first and second runners 3.
A runner switching device 35 for switching to 3, 34 is provided. Runner switching device 35 is formed in a direction perpendicular to the paper surface in (b) of FIG. 4, the cylinder 36 of the cross section semicircle, a valve body 37 which is slidingly guided in the cylinder 36, the valve body And a piston / cylinder device A for driving the driving device 37.

As shown in FIG. 5A, the valve body 37 has a shape obtained by dividing a cylinder into two in the axial direction. The lower surface 38 slides in contact with the parting surface of the fixed mold 30. On the lower surface 38 of the valve body 37, first and second resin paths 39 and 40, which are notched to a predetermined depth so as to cross the valve body 37, are formed at predetermined intervals. Then, a first through hole 39 ′ is formed in the first resin path 39. A groove 41 having the same depth in the axial direction extends from the second resin path 40 toward the first resin path 39, and a second through hole 40 ′ is formed at an end of the groove 41. . Therefore, when the valve body 37 is driven to the first position shown in (b) and (c) of FIG. 5 by the piston cylinder device A , the sprue 32 of the fixed platen 30 is connected to the first through hole 39 ′. The first through hole 39 ′ is aligned with the first resin passage 3.
9 and communicate with the first runner 33. When the valve element 37 is driven to the second position shown in FIGS. 5D and 5E, the sprue 32 passes through the second through hole 40 ′, the concave groove 41 and the second resin path 40. To communicate with the second runner 34.

As shown in FIG. 4A, the first core 51 and the first concave portion are located at the center of the fixed mold 50 in the vertical direction, that is, above the sprue 32 in the figure. 52 are provided at predetermined intervals. Further, a second core 53 and a second concave portion 54 are similarly provided at a predetermined distance below the sprue 32. The above-mentioned first core 51 and second core 53 are formed at positions equidistant from the center position where the sprue 32 is provided, and the first and second concave portions 52 and 54 are also formed at positions equidistant from each other. Is formed. Although not shown in the figure,
These cores 51 and 53 and recesses 52 and 54 are also balanced in the left-right direction. Since they are provided symmetrically in this manner, no offset load acts on the fixed mold 30 or the like at the time of mold clamping or at the time of primary and secondary molding.

A first sub-sprue 55 communicating with the first runner 33 opens on the top surface of the first core 51, and a bottom of the first recess 52 communicates with the first runner 33 similarly. The opened second sub-sprue 56 is open. Similarly, the second
A third sub-sprue 57 communicating with the first runner 33 is opened on the top surface of the core 53 of the third sub-sprung, and a fourth sub-sprue similarly communicating with the first runner 33 is formed at the bottom of the second recess 54. 58 is open. The fixed mold 30 is further provided with first and second sub sprues 59, 59 'for secondary molding. The first and second sub-sprue 5 for these secondary moldings
9, 59 'communicate with the second runner 34, respectively.

The slide mold is composed of first and second slide molds 60 and 60 'divided at substantially the center in the vertical direction. A first recess 61 and a first core 62 that form a pair with the first core 51 and the first recess 52 of the fixed mold 50 are formed in the first slide mold 60 located above. Have been. Thereby, the first and second cavities 6 for forming the first and second semi-hollow molded products A and B are provided between the fixed die 50 and the first slide die 60.
4, 65 are formed. Also, the second core 53 of the fixed mold 30 is provided to the second slide mold 60 ′ located below.
In addition, a second concave portion 61 'and a fourth core 62' that form a pair with the second concave portion 54 are formed respectively. Thereby, the third and fourth cavities 64 'and 65' for forming the third and fourth semi-hollow molded products A 'and B' are similarly formed.

The first slide die 60 is driven vertically by a piston cylinder device 66 as a driving device, and the second slide die 60 'is similarly driven downward and upward by a piston cylinder device 66'. To be driven. Well-known ejector pins 70, 70 'face the bottoms of the first and second concave portions 61, 61', and these ejector pins 70, 70 '
1, 71 'protrudes into the first and third cavities 64, 64'.

Next, the first to fourth semi-hollow molded articles A, B, A ', B are formed by primary molding using the fixed mold 50 and the first and second slide molds 60, 60'. 'Molded
Then, a molding method for molding a hollow molded article by injecting a molten resin into the periphery thereof by secondary molding will be described. First, second
The slide molds 60 and 60 'are slid to the first position shown in FIG. Further, the valve body 37 of the runner switching device 35 is also switched to the first position shown in FIGS. Then, the molten resin for the primary molding is injected from the sprue 32 of the fixed platen 30 in a known manner. The molten resin flows from the sprue 32 of the fixed platen 30 to the first through hole 39 ′ of the valve body 37 of the runner switching device 35, the first resin passage 39, the first runner 33 and the first to fourth sub sprues 55 to 58. To fill the first to fourth cavities 64-65 '. This allows
First to fourth primary semi-hollow molded articles A, B, A ', B' are molded. The state after the primary molding is completed is shown in FIG.

After the cooling and solidification, the movable plate 67 and the first and second
The slide dies 60 and 60 'are opened at a predetermined interval. Then, the first slide die 60 is slid upward by the piston cylinder device 66 so that the opening of the first semi-hollow molded product A is aligned with the opening of the second semi-hollow molded product B. Move to position 2. Second slide mold 60 '
Is slid downward by the piston cylinder device 66 ', and moved to a second position where the opening of the third semi-hollow molded article A' is aligned with the opening of the fourth semi-hollow molded article B '. Then clamp the mold. The state where the mold is clamped at the second position is shown in FIG. In this state,
The open ends of the first to fourth primary semi-hollow molded products A to B ′ are butted against each other. Further, the valve body 37 of the runner switching device 35 is switched to the second position.

A molten resin for secondary molding is injected from an injection machine. The molten resin reaches the second runner 34 through the sprue 32 of the fixed board 30, the second through hole 40 ′ of the valve body 37 of the runner switching device 35, the concave groove 41, and the second resin path 40. Then, it is injected from the first and second sub-spurs 59 and 59 ′ for secondary molding into the butting portion. Thus, the first to fourth primary semi-hollow molded articles A, B and A ′, B ′ are respectively integrated. The integrated state is shown in FIG. After cooling and solidification, the movable plate 67 and the first and second slide dies 60 and 60 'are opened. Primary semi-hollow molded product A ~
Although the surface area of B ′ is not exactly shown in the drawing, there is a difference, and when the movable metal plate 67 is opened, the integrated molded product becomes
It is opened toward the first and second slide molds 60, 60 '. The molded product is ejected by the ejector pins 70, 70 '. The above operation is repeated to mold.

According to the present embodiment, the runner switching device 3
By simply switching the fifth valve body 37 from the first position to the second position, primary molding and secondary molding can be performed, and the hollow molded article can be easily molded by the injection molding method. Also,
1 at a position where the substantially central axis of the fixed mold 50 is the center of symmetry.
Since the next molded products A, B, A ', B' are molded, a uniform load acts on the fixed mold 50, the slide molds 60, 60 'and the like at the time of molding. Further, the secondary molding is also performed at a position with the substantially central axis of the fixed mold 50 as the center of symmetry.
The unbalanced load does not act during the next molding. Therefore, the mold 5
The probability of failure occurring at 0, 60, 60 'etc. is also low,
In addition, there is obtained an effect that uneven wear and the like of the mold clamping device hardly occur.

The second embodiment can be implemented in various forms without being limited to the above example. For example, in the above embodiment, the slide dies 60, 60 'are slid up and down to take the first position and the second position, but instead of sliding, the slide dies 60, 60' The first and second positions can be adopted even when each of them is rotated. Even with such an implementation, the runner switching device 35
From the first runner 33 to the second runner 34
Obviously, it can be easily switched to
In the above-described embodiment, an example has been described in which a hollow molded product is obtained from the first to fourth primary semi-hollow molded products A to B ′. However, a primary molded product having another shape is integrally formed by secondary molding. It is also clear that molded products other than hollow molded products can be obtained in the same manner.

[0029]

As described above, according to the present invention, a pair of dies including a fixed die and a movable die are provided with a first runner,
A second runner and a shape communicating with these runners or
A plurality of cavities having different volumes and runner switching means for switching the runner are provided. When the runner switching means is switched to the first position, a main sprue connected to an injection nozzle communicates with the first runner, When switching to the two positions, the main sprue communicates with the second runner, and the switching order of the runner switching means is determined by the shape or volume of the cavity. Primary molding and secondary molding can be easily performed with the same mold. As described above, according to the present invention, the primary molding and the secondary molding can be performed by switching the runner instead of the size of the gate. It is possible to mold two or more high-quality molded products with no mold, etc. with a single-sided mold, and to easily mold hollow products such as hollow products that require primary and secondary molding. An effect unique to the present invention can be obtained. At this time, the switching order of the runner switching means is determined by the shape of the cavity or
Is determined by the volume , that is, it can be filled with a time difference in consideration of the cooling and solidification time, so that the molding efficiency can be improved. According to the invention described in claim 4, the runner switching means has a valve element which is slidably driven in the bore of the fixed platen, and the first and second resin paths of the valve element are provided on the lower surface of the valve element. Since the opening is provided, in addition to the above-described effects, an effect that the runner can be easily taken out when the mold is opened is obtained.

[Brief description of the drawings]

FIG. 1 is a view showing an example of a first embodiment of a mold according to the present invention, in which (a) is a schematic cross-sectional view showing the whole, and (b) is a plan view showing a runner portion. .

FIGS. 2A and 2B are views showing a first embodiment of a runner switching device, wherein FIG. 2A is a perspective view of a valve body, FIG. 2B is a plan view of the valve body at a first position, and FIG. (C) is a side sectional view, (d) is a plan view when the valve body is at the second position,
(E) is a side sectional view thereof.

FIG. 3 is a view showing a molding state using the mold shown in FIG. 1, and FIG.
(B) is a cross-sectional view showing a state after the secondary molding.

FIG. 4 is a view showing an example of a second embodiment of a mold according to the present invention, in which (a) is a schematic cross-sectional view showing the whole, and (b) is a plan view showing a runner portion. .

FIGS. 5A and 5B are diagrams showing a second embodiment of the runner switching device, in which FIG. 5A is a perspective view of a valve body, and FIG. 5B is a plan view when the valve body is at a first position; (C) is a side sectional view, (d) is a plan view when the valve body is at the second position,
(E) is a side sectional view thereof.

6 is a view showing a molding state using the mold shown in FIG. 4, in which (a) shows a state after the primary molding,
(B) is a cross-sectional view showing a state after the secondary molding.

[Explanation of symbols]

 1, 30 Fixed board 2, 32 Sprue (main sprue) 3, 35 Runner switching device 5, 37 Valve 6, 38 Lower surface 7, 39 First resin path 8, 40 Second resin path 11, 33 First Runner 12, 34 Second runner 13, 14, 53-59, 59 'Subsprue

Continuation of the front page (56) References JP-A-4-301422 (JP, A) JP-A-2-36918 (JP, A) JP-A-63-189616 (JP, U) JP-A-59-169911 (JP) , U) Shokai Sho 59-169919 (JP, U) Shokai Sho 56-74719 (JP, U) Injection molding dies, pp. 100-101 (Nikkan Kogyo Shimbun, December 10, 1976 (Issue 4th edition) (58) Fields surveyed (Int. Cl. ⁷ , DB name) B29C 45/00-45/84

Claims (4)

(57) [Claims] 1. A fixed mold (10, 50) and a movable mold (2).
0, 60, 60 '), a first runner (11, 33) and a second runner (12, 34).
And a plurality of cavities communicating with these runners and having different shapes or volumes , and runner switching means for switching the runners, wherein the runner switching means (3, 35) is provided. Is switched to the first position, the main sprue (2, 3) connected to the injection nozzle (N)
2) communicates with the first runner (11, 33) and switches to the second position, the main sprue (2, 32) communicates with the second runner (12, 34) and the runner switching. The order in which the means are switched depends on the shape of the cavity.
Or an injection mold characterized by being determined by volume . 2. The method according to claim 1, wherein the first or second runner (11, 12, 33, 34) has a plurality of sub-sprues (1).
3, 14, 55-59, 59 '). 3. The movable mold according to claim 1, wherein the movable mold slides or rotates with respect to a fixed mold, and the first runner has one. A mold for injection molding, wherein the second runner (34) is a runner for secondary molding for integrating the primary molded product with a runner for primary molding for molding the next molded product. 4. The runner switching means (3, 35) according to claim 1 is slidably driven in a bore (4, 36) of a fixed board (1, 30). Valve (5, 3
7), and the valve body (5, 37) has a lower surface (6,
38), the first and second resin paths (7, 8, 39, 4).
0) is formed, and when the valve element (5, 37) is at the first position, the main sprue (2, 32) connected to the injection nozzle is connected to the second sprue via the first resin path (7, 39). The first runner (11, 33) communicates with the second runner (12, 34) via the second resin path (8, 40) when driven to the second position. Mold.