JP5267949B2 - Synthetic resin piston-like member and injection mold - Google Patents

Description

The present invention relates to a synthetic resin-made piston-like member used for a manual push-down pump or the like used by being assembled and fixed to a mouth tube portion of a container body, and an injection mold for injection-molding this piston-like member It is about.

FIG. 2 of the cited document 1 shows a typical example of a manual push-down pump used by being assembled and fixed to the mouth tube portion of the container body. FIG. 7 shows an example of this type of manual depression pump.
In FIG. 7, a manual push-down pump 1 is mainly disposed in the vicinity of a cylindrical upper end portion of a cylinder portion 2 having a flange 3 attached to an outer flange shape, and is disposed inside the cylinder portion 2 so as to be movable up and down in a close sliding manner. And the nozzle head 15 provided with a nozzle 15a fitted to the upper end of the piston portion 104.
And this pump 1 is assembled | attached and fixed to the mouth tube part 19 of the container main body 18 via the packing 20 by the flange 3 using the assembly | attachment cap 16, and is used.

FIG. 8 shows the piston portion 104 used in the pump 1 shown in FIG.
This piston portion 104 is provided with a seal tube piece 107 attached to the outside of the lower end portion of a cylindrical stem 105 via an outer flange-like connecting portion 106.
The seal cylinder piece 107 has its side peripheral walls gradually enlarged in diameter with the upper end facing upward and the lower end facing downward to form the seal portions 108a and 108b in the upper and lower directions. The outer peripheral surfaces 108a and 108b are in close sliding contact with the inner peripheral surface of the cylinder portion.

On the other hand, Reference 2 describes an injection mold having a submarine gate as an injection gate. FIG. 11 shows an example of a mold provided with a submarine gate.
The mold 51 includes an upper mold 51a and a lower mold 51b. The lower mold 51b forms a side peripheral surface of a molded product at the tip of a runner 57 disposed along the parting line 56. The submarine gate 58 is inclined so as to be embedded in the mold wall, and the tip of the submarine gate 58 is connected to the cavity surface 53 of the lower mold 51b to open the gate port 58p. In addition, ejector pins 59a and 59b are disposed on the lower mold 51b.

The above-described side peripheral surface of the seal cylinder piece 107 of the piston portion 104 is molded using a cavity mold 52 having a submarine gate 58 as shown in FIGS. 9 and 10A. As shown in FIG. 10A, the submarine gate 58 is disposed so that the gate port 58p opens to the cavity surface 53 corresponding to the substantially central height position of the seal cylinder piece 107.
FIG. 9 is a perspective view of the cavity mold 52 in FIG. 10A, and is a perspective view with the lower side in FIG. )

Japanese Patent Laid-Open No. 2000-16452 JP 2005-169893 A

Here, FIG.10 (b) shows the state in the middle of die-cutting the piston part 104 of FIG. 8 from the state of Fig.10 (a). (In the figure, the white arrow indicates the drawing direction.)
As shown in this figure, when the mold is cut, the seal portion 108a on the seal cylinder piece 107 formed in an upwardly expanding diameter is opened to the cavity surface 53 of the cavity mold 52. In some cases, the contact with the peripheral edge of the opening of the gate port 58p is strong, and the seal 108a is deformed or partially damaged by such contact. As a result, the sealing performance is impaired and the function as a pump is sufficiently exerted. There arises a problem that it cannot be performed and the smooth slidability in the vertical direction is impaired.

In the synthetic resin piston-like member having the seal cylinder piece as described above, the deformation and damage of the seal portion at the time of mold release from the mold due to the gate opening of the injection gate are prevented. The object of the present invention is to provide a synthetic resin-made piston-like member that has a technical problem of preventing it from a mold shape and exhibits a high productivity, a sealing function and a smooth slidability.

Among the means for solving the above problems, the main configuration of the present invention relating to the synthetic resin piston-shaped member is as follows.
In the piston member made of synthetic resin that can be moved up and down inside the cylindrical member,
A seal cylinder piece is continuously connected to the outside of the cylindrical stem via an outer flange-shaped connecting portion, and the diameter of the seal cylinder piece is gradually increased with the upper end portion facing upward and the lower end portion facing downward. The upper and lower seal portions are formed and the outer peripheral surfaces of the upper and lower seal portions are in close sliding contact with the inner peripheral surface of the cylindrical member,
Protruding portions are provided at predetermined positions between the upper and lower seal portions on the side peripheral surface of the seal cylinder piece,
The protruding height of this convex part is a range that does not protrude outward from the upper and lower seal parts,
It is said that the injection gate is provided with an injection gate at the position of the convex portion to be injection molded.

Here, in the above configuration, the term “cylindrical member” or “piston-like member” is used instead of the term “cylinder part” or “piston part”, which is a member constituting the above-described manual depression pump.
This is because the piston-like member of the present invention is not limited to a member used in a manual push-down pump, and is generally widely disposed inside the cylinder-like member so as to be movable up and down in a close sliding manner. In view of the fact that the present invention can be applied to other members, the term “cylindrical member” or “piston member” is used from such a viewpoint.

And according to the said structure, let the shape of a seal | sticker cylinder piece be the shape which protruded in the predetermined position between the upper and lower seal parts of the side peripheral surface, and the gate port of the injection gate is formed in this convex part position. By arranging and injection molding,
The cavity surface of the mold forming the side peripheral surface of the seal cylinder piece is provided with a concave portion at a position corresponding to the convex portion, and the gate port of the injection gate opens to the cavity surface provided with the concave portion. It is possible to effectively prevent the problem that the seal part on the seal cylinder piece is in strong contact with the peripheral edge of the opening of the gate port.

In addition, the above-described prevention effect by the convex portion (the concave portion of the mold surface) can surely prevent deformation and damage of the seal portion of the seal cylinder piece, and the seal function and smooth slidability are fully exhibited. A synthetic resin piston-like member can be provided.
Further, the means according to the above configuration is not the adjustment of the molding conditions relating to die cutting or the like, but corresponds to the mold shape, and can reliably prevent deformation and damage of the seal portion of the cylinder piece with high productivity. .

  Further, by setting the protruding height of the convex portion within a range that does not protrude outward from the upper and lower seal portions, the convex portion does not interfere with the sealing function of the seal portion with respect to the cylindrical member.

  Another configuration of the present invention relating to the synthetic resin piston-shaped member is that the shape from the top of the convex portion toward the lower base end portion is a gently inclined surface in the main configuration described above.

The shape of the convex portion can be determined in consideration of the die-cutting property of the convex portion itself in addition to the effect of preventing strong contact with the peripheral edge of the gate opening of the seal portion. Thereby, the strong contact to the opening peripheral part of the gate opening of a seal | sticker part can be more effectively relieve | moderated with the smooth mold release property of convex part itself.
In addition, it is preferable that the width of the convex portion is as narrow as possible, and the protrusion height is about 0.03 mm, so that the effect of preventing strong contact with the peripheral edge portion of the gate opening of the seal portion is exhibited.
Of course, the protruding height of the convex portion is not limited to about 0.03 mm, and the effect of preventing the above contact, the seal portion moldability and the mold release property, etc., as long as it does not protrude outward from the upper and lower seal portions. It can be determined as appropriate in consideration.

  Still another configuration of the present invention relating to the synthetic resin piston-shaped member is that, in the main configuration, a cylindrical cylinder portion, and a cylindrical piston portion disposed in close sliding contact with the inside of the cylinder portion, It has a nozzle head portion fitted to the upper end portion of the piston portion, and is used as a piston portion of a manual push-down pump that is assembled and fixed to the mouth tube portion of the container body. .

  The said structure concerns on the main uses of the synthetic resin piston-shaped member of this invention. By using the piston-like member of the present invention as a piston portion of a manual push-down pump, it is possible to provide a manual push-down pump that exhibits sealing performance reliably, has a smooth slidability, and is excellent in operability. .

Next, among the means for solving the above-described problems related to the present invention, the main configuration of the present invention related to the injection mold is as follows:
A seal cylinder piece is continuously connected to the outside of the cylindrical stem via an outer flange-like connecting portion, and the diameter of the seal cylinder piece is gradually increased with the upper end facing upward and the lower end facing downward. The piston-like member configured to form the seal part up and down by an injection gate that opens a gate port in a portion corresponding to the space between the upper and lower seal parts of the cavity surface forming the side peripheral surface of the seal cylinder piece. An injection mold for injection molding,
A predetermined region of the cavity surface portion is engraved to form a recess, and a gate opening is positioned in the recess.

The above-described configuration is an injection molding metal for molding the synthetic resin piston-like member of the present invention which is injection-molded by arranging the gate port of the injection gate at the position of the convex portion formed on the side peripheral surface of the seal cylinder piece. It relates to the mold.
Then, a predetermined region of the cavity surface portion is engraved to form a recess, and the gate port of the injection gate is opened at the cavity surface where the recess is engraved. In this case, it is possible to reliably prevent the seal portion from being deformed or damaged by the upper seal portion whose diameter is gradually increased upwardly in the seal cylinder piece and is in strong contact with the peripheral edge portion of the opening of the gate port.

Since the present invention has the above-described configuration, the following effects can be obtained.
In the one having the main configuration of the synthetic resin piston-like member of the present invention, the shape of the seal cylinder piece is a shape in which a convex portion is protruded at a predetermined position between the upper and lower seal portions of the side peripheral surface. Since the injection gate is provided with the injection gate at the position of the protrusion, the cavity surface of the mold that forms the side surface of the seal cylinder piece corresponds to the protrusion. Since the recess is engraved at the position where the gate port of the injection gate is located in this recess, the upper seal portion formed in a gradually expanding diameter of the seal cylinder piece is strongly against the opening peripheral edge of the gate port. The problem of contact can be effectively prevented.

(A) is a half vertical side view showing a piston portion which is an embodiment of the piston-like member of the present invention, and (b) is an enlarged view of a seal cylinder piece in (a). FIG. 2 is a schematic explanatory view showing an example of an injection mold of the present invention for forming the member of FIG. FIG. 3 is a perspective view of a second cavity mold in FIG. 2. It is a schematic explanatory drawing which expands a principal part and shows the state in the middle of the die cutting process of the member of FIG. It is a half vertical side view which shows the sealing member which is the other Example of the piston-shaped member of this invention. (A) is an example of a pouring container with a sliding bottom lid, (b) is a half-longitudinal section showing a sliding bottom lid which is still another embodiment of the piston-like member of the present invention used in the container of (a). It is a side view. It is a vertical side view which shows an example of a manual depression pump. It is a semi-longitudinal side view which shows the piston part in FIG. It is a perspective view of the cavity metal mold | die which arrange | positioned the submarine gate for shape | molding the piston part of FIG. FIG. 9 is a schematic explanatory diagram of a process of punching out the piston part of FIG. 7 from the mold of FIG. 8. It is a schematic explanatory drawing which shows an example of the injection mold which arrange | positioned the submarine gate.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below along the examples with reference to the drawings.
FIG. 1 shows an embodiment of a synthetic resin piston-like member according to the present invention.
This piston-like member shows the piston part 4 according to the present invention used as a member of the manual push-down pump 1 shown in FIG. 7 in place of the conventional piston part 104 shown in FIG. Yes, (a) half vertical side view, (b) is an enlarged view of the vicinity of the seal cylinder piece 7 in (a).
The piston portion 4 is an injection-molded product made of high-density polyethylene resin, and has a cylindrical stem 5, and a seal cylinder piece 7 is connected to the outside of the lower end portion of the stem 5 via an outer flange-shaped connecting portion 6. It is set.
In addition, the seal cylinder piece 7 has its side peripheral wall gradually enlarged in diameter with the upper end facing upward and the lower end facing downward to form seal portions 8a and 8b in the upper and lower sides. The outer peripheral surfaces of the seal portions 8a and 8b are in close sliding contact with the inner peripheral surface of the cylinder portion 2 which is one of the members constituting the manual push-down pump 1 shown in FIG. Yes.

The piston part 4 is different from the conventional piston part 104 shown in FIG. 8 in that a predetermined position between the upper and lower seal parts 8a and 8b on the side peripheral surface of the seal cylinder piece 7, that is, as will be described later. The point is that a pair of left and right projections 9 project from a region where the gate opening of the submarine gate, which is one of the injection gates of the molding die, is opened.
Further, as shown in FIG. 1B, the projecting height of the convex portion 9 is set in a range that does not protrude outward from the upper and lower seal portions 8a and 8b. Thereby, this convex part 9 does not disturb the sealing function with respect to the cylinder part 2 of seal part 8a, 8b.
In this embodiment, the protruding height of the convex portion 9 is 0.03 mm.

  Further, in this embodiment, the shape from the top of the convex portion 9 toward the lower base end portion is a gently inclined surface (see FIG. 1B), and thus the convex portion 9 itself can be smoothly cut out. Can be achieved.

  Next, FIG. 2 is a schematic explanatory view showing an example of an injection mold for molding the piston portion 4 of FIG. 1 partially longitudinally, and this mold is an example of the injection mold of the present invention. It corresponds to. 3 is a perspective view of the second cavity mold 52b in FIG. 2, and is a perspective view seen with the lower side in FIG. 2 facing up for easy viewing.

2 includes a first cavity mold 52a, a second cavity mold 52b, and a core mold 55, and the side peripheral surface of the seal cylinder piece 7 of the piston portion 4 is formed by the second cavity mold 52b. Is done.
The cavity surface 53 of the second cavity mold 52b is provided with a concave portion 54 for forming the convex portion 9 formed on the side peripheral surface of the seal cylinder piece 7. (See also Fig. 3)

  Then, a submarine gate 58 is disposed so as to incline from the tip of the runner 57 disposed along the parting line 56 with the core mold 55 so as to enter the mold wall of the second cavity mold 52b. The tip of the submarine gate 58 is connected to the cavity surface 53 in which the concave portion 54 is engraved, so that the gate port 58p is located at the opening position.

FIG. 4 is a schematic explanatory view showing, in an enlarged manner, an essential part of a state in the middle of a die-cutting process from the second cavity mold 52b of the seal cylinder piece 7 portion of the piston portion 4 of FIG. (In the figure, the white arrow indicates the drawing direction.)
As can be seen in this figure, since the recess 54 is formed in the cavity surface 53, the seal portion 8a of the seal cylinder piece 7 can be smoothly molded without contacting the peripheral edge of the gate port 58p of the submarine gate 58. Unplugging can be achieved.
On the other hand, in the conventional mold having no recess 54, as described above, the seal portion 108a may be in strong contact with the peripheral edge of the opening of the gate port 58p as shown in FIG.

  Next, FIG. 5 is a semi-vertical side view showing a sealing member which is another embodiment of the synthetic resin piston-like member according to the present invention. This seal member 11 is used in place of the conventional seal member 111 used in the manual depression pump 1 of FIG.

Referring to FIG. 7, the nozzle head 15 is stored in a state where the nozzle head 15 is screwed to the ring body 17 disposed on the assembled cap 16 before use of the dispensing container with the manual push-down pump. In this state, the sealing member 111 closes the vent hole 5p formed through the cylinder portion 2 and exhibits a function of preventing the inflow of air.
In the state of FIG. 7 in which the nozzle head 15 is screwed off from the ring body 17 in use, the seal member 111 is displaced upward with respect to the cylinder portion 2 and the vent hole 5p is opened.

  The seal member 11 shown in FIG. 5 has a structure similar to that of the piston portion 4 of FIG. 1, and a seal cylinder piece 13 is continuously provided outside the lower end portion of the cylindrical stem 12. The upper end portion and the lower end portion of the cylindrical piece 13 are the seal portions 13a and 13b, and these points are the same as the seal member 111 shown in FIG.

  However, similarly to the piston portion 4 in FIG. 1, a convex portion 14 that does not exist in the seal member 111 in FIG. 7 is projected on the side peripheral surface of the seal cylinder piece 13 of the seal member 11. This is injection-molded by a submarine gate through the portion 14, and, like the piston portion 4 in FIG. 1, there is no deformation or damage of the seal portion 13a at the time of die-cutting, and the seal function is reliably exhibited. .

As mentioned above, although the structure of this invention and its effect were demonstrated along the Example, embodiment of this invention is not limited to the said Example.
For example, in the above embodiment, as an example of the piston-like member of the present invention, the example of the piston portion 4 and the seal member 11 used in the manual push-down pump has been described. However, the piston-like member of the present invention can be used as a manual push-down pump. It is not limited to the member to be used, and can be widely applied to a member that is generally disposed inside the cylindrical member so as to be movable up and down in a close sliding manner.

  FIG. 6A is a half-vertical side view showing an example of a dispensing container with a sliding bottom lid, and FIG. 6B is a half-vertical side view of a sliding bottom lid 25 used in this dispensing container 21. However, the sliding bottom cover 25 corresponds to an example of the piston-like member of the present invention.

The pouring container 25 shown in FIG. 6 (a) includes a container body 22 having a cylindrical body 23, a manual push-down pump 24 that is assembled and fixed to the upper end of the container body 22, and a slidable slide that can be displaced upward. The sliding bottom cover 25 is arranged in contact with the member, and the sliding bottom cover 25 is moved upward and downward as the internal pressure is reduced by pouring the content liquid, thereby preventing air from entering the container. It is what has.
In the embodiment of FIG. 6, a bottom cover 29 having a central opening is laid at the lower end of the container body 22.

As shown in FIG. 6 (b), the sliding bottom cover 25 is formed on the outer side of the short cylindrical bottom cover body 26 via the outer flange-shaped connecting piece 27, like the piston portion 4 in FIG. 1 and the upper and lower ends of the seal cylinder piece 27 are formed as seal parts 27a and 27b, and the side surface of the seal cylinder piece 27 is convex as in the piston part 4 of FIG. A portion 28 is provided so as to be injection-molded by a submarine gate through the convex portion 28, so that there is no deformation or damage of the seal portion 27a at the time of die cutting, and the inner surface of the body portion 23 is not deformed. The sealing function is reliably demonstrated.
Here, the body portion 23 corresponds to a cylinder-like member such as the cylinder portion 2 in FIG. 7, and the bottom lid body 26 of the sliding bottom lid 25 is a stem 5 of a piston-like member such as the piston 4 in FIG. It corresponds to.

In addition, for the injection mold of the present invention, the examples shown in FIGS. 2 and 3 mainly show examples of cavity molds in which a submarine gate, which is one of injection gates, is provided. The mold structure can be configured in various manners such as selecting another type of injection gate in consideration of the shape, die-cutting property, etc., and further dividing the mold.
2 and 3 show an example in which submarine gates are arranged at a pair of two locations on the left and right, but the number of submarine gates arranged depends on the shape of the piston-shaped member to be molded and the molding. In consideration of the property, it can be set to one place, and further, it can be set to three or four places. Of course, in this case, convex portions corresponding to the number of locations of the submarine gates are formed on the side peripheral surface of the seal cylinder piece of the piston-like member.

As described above, the synthetic resin piston-like member of the present invention eliminates the deformation and damage of the seal portion due to the gate port of the injection gate, and exhibits excellent sealing performance and operability. A wide range of application development can be expected as a member such as a lowering pump.

1; Manual push-down pump 2; Cylinder part 3; Flange 4 and 104; Piston part 5 and 105; Stem 5 p; Vent hole 6 and 106; Connection piece 7 and 107; Seal cylinder piece 8a and 8b; Seal part 9; convex parts 11 and 111; seal member 12; stem 13; seal cylinder pieces 13 a and 13 b; seal part 14; convex part 15; nozzle head 15 a; Main body 19; mouth tube portion 20; packing 21; pouring container 22; container body 23; barrel portion 24; manual push-down pump 25; sliding bottom lid 26; bottom lid body 27; 28; convex portion 29; bottom cover 51; mold 51a; upper mold 52b; lower mold 52; cavity mold 52a; first cavity mold 52b; Surface 54; recess 55; core die 56; parting line 57; runner 58; submarine gate 58p; gate port 59a; ejector pin 59b;

Claims (4)

A synthetic resin piston-like member disposed on the inner side of the cylinder-like member so as to be movable up and down, and a seal cylinder piece is continuously provided on the outer side of the cylindrical stem via an outer flange-like connecting portion. The upper and lower seal portions are gently expanded in diameter with the upper end portion facing upward and the lower end portion facing downward to form seal portions in the upper and lower portions, and the outer peripheral surface of the upper and lower seal portions is the inner peripheral surface of the cylindrical member. A projecting portion projecting at a predetermined position between the upper and lower seal portions on the side peripheral surface of the seal cylinder piece, and the projecting height of the projecting portion is determined from the upper and lower seal portions. A synthetic resin-made piston-like member characterized in that it is an area that does not protrude outward and is injection-molded by providing a gate port of an injection gate at the position of the convex portion. The synthetic resin piston-like member according to claim 1, wherein the shape from the top of the convex portion toward the lower base end portion is a gently inclined surface. A cylindrical cylinder part, a cylindrical piston part disposed in close contact with the inside of the cylinder part, and a nozzle head part fitted to the upper end part of the piston part; The synthetic resin-made piston-like member according to claim 1 or 2, wherein the piston-like member is used as a piston portion of a manual push-down pump that is assembled and fixed to a mouth tube portion. A seal cylinder piece is connected to the outside of the cylindrical stem via an outer flange-like connecting portion, and the diameter of the seal cylinder piece is gradually increased with the upper end portion facing upward and the lower end portion facing downward. An injection gate that opens a gate port at a portion corresponding to a space between the upper and lower seal portions of a cavity surface that forms a side peripheral surface of the seal cylinder piece. An injection mold in which an injection molding is performed by the above-described method, wherein a concave region is formed by engraving a predetermined region of the cavity surface portion, and a gate opening is located in the concave portion.

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