KR102435415B1 - double injection mold improving rotation structure - Google Patents

Abstract

The present invention relates to a double injection mold with an improved rotational structure, and more specifically, relates to a double injection mold capable of reducing frictional force and load of a motor by improving the rotational structure of a conventional shaft which rotates only by being in contact with a bush. The double injection mold with an improved rotational structure of the present invention includes a fixed mold, a movable mold compatible with the fixed mold, and a core part installed in the fixed mold and forming first and second cavities when combined with the movable mold, and a core rotating means for rotating the core part.

Description

Double injection mold improving rotation structure

The present invention relates to a double injection mold having an improved rotational structure, and more particularly, to a dual injection mold capable of reducing frictional force and reducing motor load by improving the conventional rotational structure of a shaft that rotates only in contact with a bush. will be.

In general, double injection is a method of molding a product made of two different resins or two resins of different colors by sequentially injecting two different resins or molten synthetic resins of different colors in a single mold.

The injection mold for this double injection has two injection parts so that two types of resins can be injected, and the first cavity into which the first resin is injected, and the secondary injection molded product into the primary injection molded product in the first cavity. It is configured to include a second cavity into which the second resin is injected and injected.

This double injection has less restriction on shape, wide range of product application, and diversification of design is possible. In addition, since two types of resins are injection-molded at the same time, the production efficiency is increased, reducing production costs and increasing productivity, unlike the prior art where two types of resins were injected separately and then fused and bonded or went through a painting process. can

A double injection mold is disclosed in Republic of Korea Public Utility Model No. 20-2010-0000722. The configuration and operation of such a double injection mold are shown in FIGS. 1 and 2 .

The double injection mold is usually composed of a fixed-side mold 10' and a movable-side mold 30', and is molded and opened. , the resin injection part is positioned to penetrate the fixed side mold 10', including the first injection machine 11' and the second injection machine 13', to be connected to the following cavity. The movable side mold 30' includes a core 31', a movable side platen 33', a shaft 35', and a bush 37'.

The core 31' is configured to form a space in which the resin is injected when the fixed side mold 10' and the movable side mold 30' are molded, and the first cavity 311' and the second cavity 313'. includes The first cavity 311 ′ is a space in which the first injection product 311a ′ is molded, and the second cavity 313 ′ is a space in which the second injection product is molded and has a shape corresponding to the external shape of the injection product.

The shaft 35' is formed by the first cavity 311' in a configuration that linearly moves (A', C') and rotates (B') the core 31' from the movable side platen 33'. 1 is configured to move the injection product to the second cavity 313 ′, and penetrates the movable side template 33 ′ and is coupled to the lower side of the core 31 ′. The bush 37' serves to prevent wear due to friction or the like while the shaft 35' moves within the movable side mold 30'.

The above-described double injection mold includes a bush to prevent or minimize friction between the shaft and the movable side mold when the core rotates. As such, when the shaft rotates only in contact with the bush, there is a problem of causing wear of the shaft or damage to the bush due to friction with the bush. In addition, it causes a large load on the motor connected to the shaft.

Republic of Korea Public Utility Model No. 20-2010-0000722: Double injection mold containing self-lubricating plastic bush

The present invention was created to improve the above problems, and it is an object of the present invention to provide a double injection mold capable of reducing frictional force and reducing the load on the motor by improving the rotational structure of the conventional shaft that rotates only in contact with the bush. .

A double injection mold with improved rotational structure of the present invention for achieving the above object includes: a fixed mold; a movable mold capable of being molded with the fixed mold; a core part installed in the fixed mold to form first and second cavities when combined with the movable mold; and a core rotating means for rotating the core part after separating it from the stationary mold, wherein the core rotating means includes a cylindrical cover mounted on the stationary mold to penetrate the stationary mold, and inserted inside the cover A shaft having one side coupled to the core part and a plurality of bearings installed at regular intervals between the shaft and the cover are provided.

The core rotating means further includes a fixing bush installed between the bearings to prevent the bearings from moving when the shaft is linearly moved to fix the inner rings of the bearings.

The core rotating means further includes a moving bush installed between the bearings to cope with deformation due to thermal expansion of the bearings.

The core rotating means further includes a support bush coupled to one side of the cover to support the moving bush.

The core rotating means further includes an elastic member for absorbing the load transmitted from the support bush.

As described above, the present invention can significantly reduce frictional resistance during linear and rotational motion of the shaft by improving the conventional shaft rotation structure that rotates only in contact with the bush by installing the bearing and the bush together around the shaft. . In addition, it is possible to effectively reduce the load on the motor.

1 is a cross-sectional view showing a cross-section of a conventional double injection mold,
Figure 2 is a cross-sectional view for showing the operation of Figure 1,
3 is a cross-sectional view of a double injection mold according to an embodiment of the present invention;
Figure 4 is a perspective view of the shaft applied to Figure 3,
5 is a cross-sectional view taken from the main part of FIG. 3,
Figure 6 is a cross-sectional view showing the operation of Figure 3,
7 is a cross-sectional view taken from a main part of a double injection mold according to another example of the present invention.

Hereinafter, a double injection mold with improved rotational structure according to a preferred embodiment of the present invention will be described in detail.

The double injection mold of the present invention is an injection mold for sequentially injecting two dissimilar resins or molten synthetic resins of different colors in one mold to mold a product made of two dissimilar resins or two resins having different colors.

3 to 6, the double injection mold according to an embodiment of the present invention is installed in a stationary mold 10, a movable mold 20 that can be molded to the stationary mold 10, and a stationary mold 10. The core part 30 forming the first and second cavities 21 and 23 when combined with the movable mold 20, and the core rotation for rotating the core part 30 after separating the core part 30 from the stationary mold 10 have the means

The fixed mold 10 is located on one side of the movable mold 20 . In a state in which the stationary mold 10 is fixed, the movable mold 20 is moved and molded and molded.

The core part 30 is installed in the stationary mold 10 . The core part 30 is provided with two cores 31 and 33 . For example, the first core 31 and the second core 33 are spaced apart and provided in parallel. The first core 31 and the second core 33 have the same shape.

The core part 30 rotates 180° after being separated from the stationary mold 10 by the core rotating means.

The movable mold 20 forms a cavity space in which molten resin is injected and molded into a predetermined shape. In the illustrated example, two cavities 21 and 23 are provided. For example, the first cavity 31 is formed at a position corresponding to the first core 31 , and the second cavity 23 is formed at a position corresponding to the second core 33 .

The movable mold 20 is connected to the first inlet 25 and the second cavity 23 connected to the first cavity 21 so that the molten resin can be injected into the first and second cavities 21 and 23 . The second inlet 27 is formed, respectively.

The core rotating means serves to rotate the core part 30 after separating the core part 30 from the stationary mold 10 by pushing the core part 30 in the direction of the movable mold 20 .

The illustrated core rotating means includes a cylindrical cover 40 mounted on the stationary mold 10 so as to penetrate the stationary mold 10 , and a shaft inserted into the cover 40 and one side of which is coupled to the core part 30 . 50 and a plurality of tapered roller bearings 60 installed at regular intervals between the shaft 50 and the cover 40 are provided.

The cover 40 has a hollow cylindrical structure. The cover 40 supports the bearing 60 to cover the load transmitted from the shaft 50 and determines the straightness of the shaft 50 .

In order to fix the cover 40 to the stationary mold 10 , a cap 45 is installed on one side of the stationary mold 10 , and a fixing plate 47 is installed on the other side of the stationary mold 10 . One side of the cover 40 is in contact with the cap 45 , and the other side of the cover 40 is in contact with the fixing plate 47 .

A circular through-hole is formed in the center of the cap 45 and the fixing plate 47 so that the shaft 50 can pass through the cap 45 and the fixing plate 47 .

The shaft 50 is inserted inside the cover 40 . The outer diameter of the shaft 50 is formed smaller than the inner diameter of the cover (40). One side of the shaft 50 is coupled to the core part 30 , and the other side of the shaft 50 is connected to the connection shaft 5 of a conventional driving equipment. The shaft 50 is capable of linear motion and rotational motion inside the cover 40 by a driving device. The surface of the shaft 50 is preferably surface-treated to have a high degree of smoothness.

A flow path 51 passing through the center of the shaft is formed inside the shaft 50 . And a rotation guide groove 53 and a straight guide groove 55 are formed on the outer peripheral surface of the shaft 50 .

The rotation guide groove 53 is formed at 360° along the circumference of the outer peripheral surface of the shaft 50 . When the shaft 50 rotates, the rotation guide groove 53 becomes a groove for accommodating the key 5 to be described later. The shaft 50 is rotatable only when the key 5 is positioned in the rotation guide groove 53 .

The straight guide groove 55 extends from one end of the shaft 50 to the rotation guide groove 53 in a straight line. Two straight guide grooves 55 are formed at intervals of 180°. On the contrary, when only one key 5 is installed, of course, only one straight guide groove 55 may be formed. It is located in the straight guide groove 55 for moving the shaft 50 in a straight line.

The bearing 60 is installed at a predetermined interval between the shaft 50 and the cover 40 . An appropriate number of bearings 60 is installed depending on the load applied to the shaft 50 and the length of the shaft 50 .

A roller bearing or a ball bearing may be used as the bearing 60 . The illustrated example shows a state in which a tapered roller bearing is applied as the bearing 60 . Tapered roller bearings can withstand high radial and axial loads.

The shaft 50 is inserted into the bearing 60 . Accordingly, the inner ring of the bearing 60 is in contact with the outer circumferential surface of the shaft 50 , and the outer ring of the bearing 60 is in contact with the inner circumferential surface of the cover 40 . When the shaft 50 moves in a straight line, the shaft 50 slides in contact with the inner ring of the bearing 60 .

A fixing bush 71 is installed between the bearings 60 to prevent movement of the bearings 60 when the shaft 50 is linearly moved. The fixing bush 71 is in contact with the outer peripheral surface of the shaft 50 . A plurality of fixing bushes 71 are installed at regular intervals along the longitudinal direction of the shaft 50 . Among the plurality of fixing bushes 71 , each of the fixing bushes 71a positioned on the front and back sides has a rather short width.

Both edges of the fixing bush 71 are in contact with the inner ring of the bearings 60 and serve to fix the inner ring of the bearing 60 .

A key 5 is formed to protrude from the inner circumferential surface of any one of the plurality of fixing bushes 71 . Two keys 5 are formed at intervals of 180° on the inner circumferential surface of the fixing bush 71 .

Meanwhile, a moving bush 73 is further installed between the bearings 60 in order to respond to deformation due to thermal expansion of the bearings 60 . The moving bush 73 is formed to surround the fixed bush 71 from the outside. Accordingly, the inner peripheral surface of the moving bush 73 is in contact with the outer peripheral surface of the fixed bush 71 , and the outer peripheral surface of the moving bush 73 is in contact with the inner peripheral surface of the cover 40 . Both edges of the moving bush 73 are in contact with the outer ring of the bearing 60 . The moving bush 73 serves to absorb the micro-movement of the bearing 60 due to the thermal expansion of the shaft 50 .

Among the plurality of moving bushes 73 , each of the moving bushes 73a positioned at the front and rear sides has a rather short width.

And a support bush 75 may be further installed to support the moving bush 73 . The support bush 75 is coupled to one side of the cover 40 and is in contact with the moving bush 73a installed at the frontmost side. The movement of the fine bearing 60 transmitted during thermal expansion of the shaft 50 or movement of the shaft 50 is transmitted to the support bush 75 through the moving bush 73 . In order to absorb the load transmitted from the support bush 75, it is preferable that the elastic member 77 is installed in the present invention.

A spring may be applied to the elastic member 77 . The elastic member 77 is installed between the cap 45 and the support bush 75 . An insertion groove into which one side of the elastic member 77 is inserted is provided in the cap 45 , and an insertion groove into which the other side of the elastic member 77 is inserted is provided in the support bush 75 . The elastic member 77 installed between the cap 45 and the support bush 75 effectively absorbs the load transmitted from the support bush 75 .

The present invention having the above-described core rotating means greatly reduces frictional resistance during linear and rotational motion of the shaft by improving the conventional shaft rotation structure that rotates only in contact with the bush by installing a bearing and a bush together around the shaft. In addition to this, it is possible to effectively reduce the load on the motor that rotates the shaft.

After the molten resin is injected into the first cavity 21 and the primary injection product is molded, the movable mold 20 is separated from the stationary mold 10 and opened. Thereafter, when the shaft 50 is pushed in the direction of the movable mold 20 by the driving equipment, the core part 30 is separated from the stationary mold 10 to be in a state as shown in FIG. 6 . When the shaft 50 is rotated 180° in this state, the first core 31 on which the primary injection molded in the first cavity 21 is placed moves to the position of the second cavity 23, and the second core 33 ) moves to the position of the first cavity 21 . Then, the shaft 50 is moved in the direction of the stationary mold 10 again to couple the core part 30 to the stationary mold 10 , and then the movable mold 20 is coupled to the stationary mold 10 . Then, a different type of resin or a molten resin having a different color is injected into the second cavity 23 to form a second injection product.

Meanwhile, as another example of the present invention, a state in which a ball bearing is applied as a bearing is shown in FIG. 7 .

Referring to FIG. 7 , the bearings 80 are installed on the shaft 50 at regular intervals. As the bearing 80 , a single row deep groove ball bearing may be used.

The shaft 50 is inserted into the bearing 80 . Accordingly, the inner ring of the bearing 80 is in contact with the outer circumferential surface of the shaft 50 , and the outer ring of the bearing 80 is in contact with the inner circumferential surface of the cover 40 . When the shaft 50 moves linearly, the shaft 50 slides in contact with the inner ring of the bearing 80 .

The fixed bush 71 and the moving bush 73 are installed on both sides of the bearing 80 as in the embodiment of FIG. 5 . Both edges of the fixing bush 71 are in contact with the inner ring of the bearing 80 and serve to fix the inner ring of the bearing 80 . Both edges of the moving bush 73 are in contact with the outer ring of the bearing 80 . The moving bush 73 serves to absorb the micro-movement of the bearing 80 due to the thermal expansion of the shaft 50 .

Components not described in FIG. 7 are the same as those of FIG. 5, and thus detailed descriptions thereof will be omitted.

As mentioned above, although the present invention has been described with reference to an embodiment, it will be understood that this is only an example, and that various modifications and equivalent embodiments are possible therefrom by those of ordinary skill in the art. Therefore, the true scope of protection of the present invention should be determined only by the appended claims.

10: fixed mold 20: movable mold
30: core part 40: cover
50: shaft 60: bearing
71: fixed bush 73: moving bush
75: support bush 77: elastic member

Claims (5)

delete a fixed mold;
a movable mold capable of being molded with the fixed mold;
a core part installed in the fixed mold to form first and second cavities when combined with the movable mold;
and a core rotating means for rotating the core part after separating it from the fixed mold;
The core rotating means includes a cylindrical cover mounted on the stationary mold so as to penetrate the stationary mold, a shaft inserted inside the cover and having one side coupled to the core part, and a predetermined interval between the shaft and the cover. It has a plurality of bearings to be installed,
The core rotating means is installed between the bearings to prevent movement of the bearings during linear movement of the shaft and further includes a fixing bush for fixing the inner rings of the bearings. . a fixed mold;
a movable mold capable of being molded with the fixed mold;
a core part installed in the fixed mold to form first and second cavities when combined with the movable mold;
and a core rotating means for rotating the core part after separating it from the fixed mold;
The core rotating means includes a cylindrical cover mounted on the stationary mold so as to penetrate the stationary mold, a shaft inserted inside the cover and having one side coupled to the core part, and a predetermined interval between the shaft and the cover. It has a plurality of bearings to be installed,
The core rotating means is installed between the bearings, the double injection mold with improved rotation structure, characterized in that it further comprises a moving bush to cope with the deformation caused by the thermal expansion of the bearings. The double injection mold with improved rotation structure according to claim 3, wherein the core rotating means further comprises a support bush coupled to one side of the cover to support the moving bush. [Claim 5] The double injection mold with improved rotation structure according to claim 4, wherein the core rotating means further comprises an elastic member for absorbing the load transmitted from the support bush.

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