JP3063300B2 - Cal release mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cull releasing mechanism,
In particular, the present invention relates to a cull releasing mechanism for preventing cull from adhering to a plunger after molding in a molding apparatus for molding a thermosetting resin.

[0002]

2. Description of the Related Art FIG. 2 is a cross-sectional view schematically showing an example of a conventional molding apparatus for molding a thermosetting resin. The molding apparatus 1 is illustrated in FIG. 2 with the upper mold and the lower mold closed, and the upper mold 2 is located above the parting line A.
The lower mold 3 is arranged at the lower part. The upper die 2 has a structure in which a plate 4a having a molding surface on a lower surface and a plate 4b are fixed with a plurality of bolts 5. Plate 4a, 4b
Has a plunger 6 inserted therethrough. Reference numeral 7 denotes a pot, and 16 denotes a transfer cylinder of a molding machine. On the other hand, the lower mold 3 is a plate 8 having a molding surface on the upper surface.
a, the spacer 8b and the base member 8c are fixed to each other. An ejector pin 9 is inserted through the center of the plate 8a. Reference numeral 11 denotes a guide pin, which is fixed to the upper mold 2 and which has a guide hole 1 of the lower mold 3.
2 so that it can be inserted through.

In the molding apparatus 1, the mold can be opened by raising the upper mold 2 from a state shown in the figure by a drive source (not shown), and closed by lowering the upper mold 2 by the drive source. It can be in a mold state. In molding, a molded article is obtained by injecting and curing a thermosetting resin in a closed state. FIG.
FIG. 3 is an enlarged sectional view showing a main part of the molding apparatus 1 shown in FIG. 2. In this molding apparatus 1, a molded article 13 made of a thermosetting resin is obtained according to the molding method described above. By the way, as is apparent from FIG. 3, after the molding is completed, a cull 14 is formed on the upper portion of the ejector pin 9, and the upper surface of the cull 14 is the tip 6 a of the plunger 6 on the upper mold side.
Closely adhered to. The tip 6a of the plunger 6 on the cull 14
, The cull 14 cannot be removed from the molding device 1 smoothly. Therefore, in order to prevent the cull 14 from adhering to the tip 6a of the plunger 6, conventionally, the tip surface 6a of the plunger 6 is polished to reduce the surface roughness of the tip surface 6a to about 0.8S. Or the tip surface 6a of the plunger 6 is hard Cr plated or PVD
The surface releasability is enhanced by making the surface smooth by performing a surface treatment such as the above.

[0004]

However, even if the surface roughness of the distal end face 6a of the plunger 6 is made fine or the above-mentioned surface treatment is performed, depending on the type of the thermosetting resin, it may still occur. And the plunger tip 6a could not be sufficiently prevented from adhering. If the material strength of the molded product 13 is low, the molded product 13 is immediately broken at the boundary between the runner 15 and the cull 14, and
Was sometimes attached. Also, depending on the molding material,
The adhesion of the plunger 6 to the distal end surface 6a is high. In such a case, it is difficult to prevent the cull 14 from adhering to the distal end surface 6a of the plunger 6 by the above-described conventional method.

An object of the present invention is to provide a cull releasing mechanism that can reliably prevent the phenomenon of adhesion between a plunger and a cull regardless of the type of thermosetting resin and the cull shape.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a cull releasing mechanism used in a molding apparatus for molding a thermosetting resin, comprising: a plunger provided in an upper mold or a lower mold;
Rotating drive means coupled to the plunger so that the plunger can be rotated less than one revolution when the mold is closed , wherein the rotary drive means rotates with the plunger.
Pinion connected to the plunger as described above, and the pinion
The Rukoto that having a rack combined in emission characterized.

[0007]

According to the cull releasing mechanism of the present invention, the plunger can be driven to rotate in the closed state. Therefore, by the rotation of the plunger, a shear stress is applied to the boundary between the distal end face of the plunger and the cull, whereby the plunger and the cull can be separated smoothly. That is,
The present invention focuses on the fact that the attachment portion between the distal end surface of the plunger and the cull is relatively tightly adhered, but can be easily separated by shearing force. Is added to facilitate the separation of the cull from the plunger.

[0008]

FIG. 4 is a schematic sectional view of a molding apparatus to which an embodiment of the present invention is applied. The molding device 21 is configured substantially similarly to the molding device 1 shown in FIG. Therefore, for the same parts as the molding apparatus 1 shown in FIG.
The description is omitted by attaching the same reference numerals. A feature of the molding device 21 is that the plunger 6 provided on the upper mold 2 is configured to be rotatable.
That is, the plunger 6 is connected to the pinion 23 via the Oldham coupling 22 on the upper end side. And the pinion 23 is connected to the rack 24,
The rack 24 is configured to be movable by the air cylinder 25 in the paper plane-paper back direction of FIG. That is, the Oldham coupling 22, the pinion 23, the rack 24, and the air cylinder 25 constitute the rotation driving means of the present invention. Note that a hydraulic cylinder may be used instead of the air cylinder 25.

The configuration of the rotation driving means will be described in more detail with reference to FIG. FIG. 1 is a cross-sectional view of a main part of the molding apparatus 21 as viewed from the right in FIG. A plunger 6 is inserted through the center of the plates 4a and 4b of the upper die 2. A pinion 23 is connected to an upper end of the plunger 6 via an Oldham coupling 22. Therefore, the plunger 6 is configured to be able to rotate together with the pinion 23. On the other hand, the pinion 23 is engaged with a rack 24, and the rack 24 has an engagement recess 24a on one end side. On the other hand, a U-shaped merging member 26 is fixed to the cylinder rod 25 a of the air cylinder 25, and the tip of the engaging member 26 is engaged with the concave portion 24 a of the rack 24. Therefore, by driving the air cylinder 25 and reciprocatingly driving the cylinder rod 25a in the direction indicated by arrow B, the rack 24 is moved in the direction indicated by arrow B so that the pinion 23 and, consequently, the plunger 6 can rotate. It is configured. In the present embodiment, the plunger 6 and the pinion 23 are connected by the Oldham coupling 22. However, when the pinion 23 and the plunger 6 have the same axis, the Oldham coupling 22
There is no need to use.

In the cull releasing mechanism of this embodiment, since the above-mentioned rotary driving means is connected to the plunger 6, after the molding is completed, the plunger 6 is driven to rotate in the direction of the arrow as shown in FIG. Thereby, the adhesion state between the tip surface 6a of the plunger 6 and the cull 14 can be eliminated. That is, the tip surface 6a of the plunger 6 and the cull 14
Are in intimate contact with each other after the completion of molding, but the intimate contact portions can be easily separated by applying shear stress. Therefore,
By the rotation of the plunger 6, the adhesion phenomenon between the cull 14 and the distal end surface 6a of the plunger is easily eliminated. However, at this time, the pressure of the plunger needs to be zero. Further, the plunger rotation does not need to be rotated once, but may be rotated by 1 °.

In the above embodiment, the pinion 23, the rack 24 and the air cylinder 25
Although the rotation drive means of the present invention is
It is not limited to this. For example, the plunger 6 may be rotated by directly connecting the plunger 6 to a rotation drive source such as a motor or the like via a gear or the like, and the plunger 6 may be rotationally driven using a rotary actuator or the like. Is also good. Further, as shown in FIG. 6, a pin 28 may be protruded from the plunger 6 and moved back and forth by an air cylinder 29 to be rotated. Further, as shown in a schematic plan view in FIG. 7, a plurality of pinions 23 are engaged with one rack 24, and the plurality of pinions 23 are connected to a plurality of plungers. The present invention can also be applied to a molding device having a plunger.

In the above-described embodiment, the cull releasing mechanism for preventing the cull 14 and the plunger 6 from adhering to each other on the upper mold 2 side has been described. May be connected. However, on the lower mold 3 side, as will be described with reference to FIGS. 8 and 9, the plunger 9 can be prevented from sticking to the cull by devising the discharging process of the molded product 13. However, the above-mentioned rotation driving means is not always necessary. That is, the discharge of the molded article 13 from the molding apparatus is usually performed by lowering the plunger 9 from the molding end state shown in FIG. 8 (FIG. 9A) and then moving the plunger 9 upward again. (FIG. 9B). As described above, on the lower die 3 side, the plunger 9 is separated from the cull when the plunger 9 is lowered once, so that the above-described rotation driving means is not necessarily required.

[0013]

According to the present invention, since the plunger provided on the upper mold or the lower mold can be rotated by the rotary driving means at the end of molding, the plunger is rotated by the rotation of the plunger. The contact between the tip surface and the cull is eliminated. That is, since shearing force is forcibly applied to the boundary between the plunger tip surface and the cull, the phenomenon of close contact between the plunger tip surface and the cull is eliminated, thereby easily separating the cull from the plunger. It becomes possible. In the cull release mechanism of the present invention, as described above, the cull is separated by applying shear stress between the tip surface of the plunger and the cull.
It does not depend on the characteristics of the molding material, so it is possible to reliably release the cull even when molding a molding material with high adhesion, and molding even when molding a molded product with a part with low mechanical strength The cull can be released without causing breakage of the product.

In addition, since it is merely a means for connecting the plunger with a means for rotating the plunger, the operation is carried out only by connecting the rotary driving means to a conventionally used general-purpose molding apparatus. be able to. Therefore, the cull mold release mechanism of the present invention designs and
It can be easily configured by follow-up processing without the need for manufacturing.

[Brief description of the drawings]

FIG. 1 is a partially cutaway sectional view for explaining a cull releasing mechanism according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view showing a conventional molding apparatus.

FIG. 3 is a partially enlarged cross-sectional view for explaining the adhesion phenomenon between a plunger and a cull.

FIG. 4 is a schematic sectional view showing a molding apparatus to which an embodiment of the present invention is applied.

FIG. 5 is a partially enlarged cross-sectional view for explaining a step of eliminating a phenomenon of close contact between a tip end surface of a plunger and a cull in the embodiment.

FIG. 6 is a plan view for explaining another example of the rotation driving unit.

FIG. 7 is a plan view for explaining a rotary drive unit when applied to a multi-plunger system.

FIG. 8 is a partially cutaway enlarged sectional view showing a state of the lower mold side at the time of completion of molding.

9 (a) is a partially enlarged cross-sectional view showing a state where a plunger is lowered on a lower mold side, and FIG. 9 (b) is a part showing a state where a molded product is removed from the mold by raising a plunger on the lower mold side. FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Molding apparatus 2 ... Upper mold 3 ... Lower mold 14 ... Cull 22 ... Oldham coupling 23 ... Pinion 24 ... Rack 25 ... Air cylinder

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-32619 (JP, A) JP-A-5-63014 (JP, A) JP-A-63-39525 (JP, U) JP-A-6-39525 77235 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 45/40 B29C 45/02 H01L 21/56

Claims (1)

(57) [Claims] 1. A cull release mechanism used in a molding apparatus for molding a thermosetting resin, comprising: a plunger provided in an upper mold or a lower mold; and when the mold is closed, the plunger is rotated less than one turn. Rotating drive means coupled to the plunger so that the plunger can rotate.
Pini connected to the plunger to rotate with
And on, characterized Rukoto that having a rack combined in the pinion, Cal release mechanism.