JPS5951419B2 - Method and device for manufacturing rubber parts with interior inserts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for manufacturing a rubber component incorporating an insert.

It is widely used in cup seals, anti-vibration rubber, grommets, and other parts to incorporate inserts into rubber parts for the purpose of reinforcing the rubber parts.

Typical examples of manufacturing methods for this type of rubber parts are shown in Figures 1 to 4.
As shown in the figure. For example, when manufacturing a ring-shaped rubber part A with an insert 11 inside as shown in FIG. Molded product 1
There is a method in which the molded products 121 and 122 are disposed facing each other, the insert 11 is fitted into the groove, and the facing contact surfaces of both molded products 121 and 122 are bonded. Another method is to attach an insert holding pin 141 to the bottom of the cavity of the mold 14 as shown in FIG.
is formed to hold the insert 11 therein, and the mold 1 is
There is a method of molding by closing the mold using 5 and press-fitting the rubber material into the cavity using means such as a plunger 16. However, the former method requires adhesion, resulting in poor workability and increased manufacturing costs, and also has unstable quality factors such as peeling due to adhesive strength.

Furthermore, in the latter method, a hole 142 remains in the rubber part obtained after the retaining pin is removed, as shown in FIG.
A part of 1 is exposed, so it cannot be said to be a complete insert interior rubber part. Furthermore, if this part is used in a liquid such as acid or alkali, if the insert is made of metal, the exposed part will corrode, making it unusable. In view of the above circumstances, it is an object of the present invention to provide a method for manufacturing a rubber component completely equipped with an insert, and a manufacturing apparatus for implementing the method with good workability. Therefore, the manufacturing method of the present invention uses a mold having a cavity for molding rubber parts as well as a cavity that communicates with the cavity and stores a rubber material to be supplied to the cavity, and inserts support pins into the cavity for molding the rubber parts. The insert is held inside, and both cavities are filled with rubber material, and the mold is released before the rubber material solidifies.At the same time, the insert support pin is removed, the mold is clamped again, and the pressurizing means is used to replenish the mold. The method is characterized in that the rubber material is pressurized and press-fitted into the cavity in the cavity for molding the rubber part after the insert support pin is removed.

The present invention also provides an apparatus for carrying out the above manufacturing method,
The present invention provides a device in which the insert support pin is automatically removed when the mold is released, and the pressurizing means is activated.

Hereinafter, the manufacturing method of the present invention will be explained with reference to Examples.

5 to 7 show the steps for manufacturing a ring-shaped rubber part according to the present invention.

In the figure, 10 is a plunger, 2 is an upper mold, 3 is a middle mold, and 4 is a plunger.
5 is a lower mold, 5 is a preforming mold, 101 is a plunger hot plate, and 41 is a lower hot plate. As shown in FIG. 5, a cavity (hereinafter referred to as a product section) 61 in which a ring-shaped rubber part is to be molded is formed between the upper die 2 and the outer die 3, and a protrusion of the upper die inside the product section is formed. As will be described later, a cavity 62 (hereinafter referred to as the preliminary material section) in which rubber material to be supplied to the product section 61 is to be stored is formed between the surface 21 and the molding surface 52 at the center of the preforming mold opposite thereto. The product section 61 and the preliminary material section 62 are in communication with each other. On the outer periphery of the molding surface 52 of the preforming mold 5, a plurality of insert support pins 53, 53, .
. . . are arranged protrudingly in a ring shape, and when the mold is closed, the support pins 53, 53, . . .
protrude inward. The support pins 53, 53, . . . have insert support grooves 53], 531, .
... is formed. A plunger 10 is placed on the surface of the upper mold 2.
A pot 63 provided opposite to the upper mold 2 communicates with the product portion 61 via a plurality of injection ports 64, 64, . . . provided in the upper mold 2. By the way, when manufacturing a rubber component having an interior insert according to the present invention, as shown in FIG.
1c..., and close the upper mold 2, middle mold 3, and preforming mold 5, pressurize the rubber material in the pot 63 with the plunger 10, and pour the rubber material into the injection ports 64, 64,・
. . . to fill the product section 61 and the preliminary material section 62 communicating therewith.

As a result, the insert θ insert 11 supported by the insert support pin 53 is wrapped in the rubber material within the product section 61. This preforming is carried out for several seconds after pressurization. At this time, the rubber material has not yet been sufficiently vulcanized and remains fluid. Immediately after the preforming, the preforming mold 5 is removed as shown in FIG.

As a result, a preform is formed, which is made of the rubber material of the product part 61 and the reserve material part 62, and has the insert 11 held within the product part 61. Insert 1 of the preform
1, some of which are insert support pins 53, 53,...
The voids 54, 54 after the separation of...
・Exposed in the hole (hereinafter referred to as the support pin hole). Next, as shown in FIG. 7, after removing the preforming mold 5, the lower mold 4 is assembled to the middle mold 3, and the preliminary material of the preformed part 62 (FIG. 6), which maintains fluidity even after being pressurized, is inserted into the support pin hole. 54,54
, . . . to completely encapsulate the insert 11, and is pressurized and vulcanized at a predetermined molding pressure and temperature for a predetermined time to complete the main compression molding.

Therefore, the rubber material of the preliminary material portion 62 is inserted into the support pin hole 54.
,54,... are filled. At the same time, it is necessary to set the amount to be sufficient to apply molding pressure. As shown in the above embodiments, the present invention involves molding a preformed product consisting of a product part that wraps around an insert supported by an insert support pin and a preliminary material part connected to the product part, and then inserting the insert from the insert. After the support pin is removed, the rubber material of the preliminary material section is press-fitted into the gap left after the support pin has been removed, and compression molded to obtain the intended insert inner rubber part.

In addition, in the present invention, it is shown in FIG. It is possible to obtain not only rubber parts but also rubber parts with inserts of various shapes as shown in FIGS. 9 and 10, and not only ring-shaped rubber parts but also plate-shaped parts as shown in FIG. Rubber parts of various shapes such as rubber parts can be obtained. Therefore, according to the present invention, it is possible to obtain a rubber part that completely encapsulates the insert, and since the rubber materials of the product part and the preliminary material part are bonded in an unvulcanized state and highly compressed, it is possible to obtain a rubber part that completely encloses the insert. There is no risk of peeling or cracking. Next, an apparatus capable of carrying out the method of the present invention with extremely good workability will be described with reference to the embodiments shown in FIGS. 12 to 16.

Note that FIGS. 12 to 14 show an apparatus and steps for carrying out the present invention using the apparatus, and FIGS. 15 and 16 are plan views of members constituting the apparatus. Note that the same parts and parts having the same function as those in the apparatus shown in FIGS. 5 to 8 are designated by the same reference numerals. In the figure, 10 is a plunger, 2 is an upper mold, 3 is a middle mold, 4 is a lower mold, 40 is a die plate, 101 is an upper hot plate, and 41 is a lower hot plate.

A cylindrical protrusion 21 is formed in the center of the upper mold 2, and a ring-shaped cavity 61, which is a product part, is formed between the outer periphery of the protrusion 21 and the middle mold 3.

A cavity 62 serving as a preliminary material portion communicating with the product portion 61 is formed between the end surface of the protruding portion 21 and the central concave surface of the lower mold 4 facing thereto. A plurality of injection ports 64, 64, . A through hole 43 is bored in the center of the lower mold 4, and the through hole opens into the preliminary material portion 62. In addition, the above-mentioned through hole 4 of the lower mold 4
A plurality of through holes 44, 44, . As shown in the half plan view of FIG. 15, the preliminary material portion 62 of the lower mold 4 has radial grooves 45 that serve as preliminary material flow paths communicating between the opening of the through hole 43 and the through hole 44 on the outer periphery thereof. , 45, . . . . Further, a plurality of guide pin holes 46, 46, . As shown in the half plan view of FIG. 16, the die plate 40 has an elliptical shape formed by combining semicircles centered on a first center point A through hole 402 is a piston sliding hole, and a through hole 4 is a guide pin sliding hole on the circumference at a predetermined distance from the center point X.
03, 403, . . . , and guide pin sliding holes 405, 405, 405 similar to the above are bored on the circumference at the same distance from the second center point Y as above.

Further, through holes 407, 407, 407, which are support pin rod sliding holes, are bored on the circumference centered on the center point Y. Guide pin sliding hole 403, 403... and 4
05, 405, ... concave grooves 408, 40 between
8,... are formed. Further, a concave groove 409 is also formed between the piston sliding hole 402 and a semicircle centered on the second center point Y. The above is the structure of half of the die plate, but the other half has a similar structure.
The central through hole 43 of the lower mold 4 forms a piston sliding hole, into which the piston 7 for extruding the preliminary material is inserted.
Around the piston rod is a torsion coil spring 73.
is installed.

Further, an insert support pin 53 is inserted into each through hole 44 provided at an annular position on the outer periphery of the through hole 43 of the lower mold 4 to form an insert support pin sliding hole, and a torsion coil spring is installed around the pin rod. 55 is installed. Furthermore, guide pin rod sliding holes 46, 4 are provided on the outer periphery of the bottom of the lower mold 4.
6, . . . are bored, a guide pin 8 is fixed to the top of each hole, and a torsion coil spring 81 is attached around the pin rod portion. The process of carrying out the method of the present invention using the above embodiment apparatus will be explained.

First, insert support pins 53, 53 as shown in FIG.
, .
The arrangement of the lower mold 4 and the piston sliding hole 43 in the center of the lower mold
The bottom opening of the die plate 40 and the bottom opening of the guide pin sliding hole 46 are shown in FIG. 16, respectively.
Place it so that it matches... Therefore, the lower ends of the pin rods of the car, dowel pins 8, 8, . is supported on a hot plate 41. Further, the bottoms of the insert support pins 53, 5, 3, . With the mold set up in this way, the rubber material in the pot 63 formed on the upper part of the upper mold 2 is pressurized by the plunger 10 to open the injection port 6.
4, 64, . . . , the product section 61 and the preliminary material section 62 communicating therewith are press-fitted and filled. As a result, the insert 11 supported within the product section 61 by the insert support pins 53, 53, . . . is wrapped with the rubber material. This preforming is carried out for several seconds after pressurization. At this time, the rubber material has not yet been sufficiently vulcanized and remains fluid. After the above-mentioned preforming, the die plate 40 and the mold above it are released from the mold, as shown in FIG.

The upper mold has guide pin sliding holes 46, 46,...
. . . Spring 81, 81. It is pushed up integrally by the urging force of... At this time, the insert support pins 53, 53, . . . are connected to the spring receivers 56, 56, .
It is pushed down by the biasing force of a spring 55 provided between the stepped portion 47 of No. 4 and is detached from the insert 11. Insert support pins 53, 53, . . . Support pin holes 54, 54, . . . are provided at the bottom of the insert 11 after detachment.
... is formed. Next, the die plate 40 is transferred.

Arrow W in FIG. 16 indicates the direction of relative movement of the lower mold 4 with respect to the die plate 40 at this time. Due to this transfer, the piston sliding hole 43 and guide pin sliding holes 46, 4 of the lower mold are
6, ... are the concave grooves 409 at the second center Y, respectively.
and die plate guide pin rod sliding hole 405,
405, . . . and the support pin sliding holes 44, 44, . . . to match the support pin rod sliding holes 407, 407, . . By closing the mold, the preliminary material extrusion piston 7 is pushed up as shown in FIG.
... through the support pin holes 54, 5 of the product part 61.
4. It is press-fitted into the inside. At this time, the lower ends of the insert support pins 53, 53, . In this way, as shown in FIG. 17, a molded product consisting of a ring-shaped rubber product 6" completely enclosing the insert 11 and a rubber material 62" attached to it as a preliminary material part is obtained.
By removing this, the desired product is obtained.
As explained above using the implementation device, the device of the present invention has the following features:
A cavity consisting of a product part and a preliminary material part communicating with the product part is formed between the first molding die and the second molding mold, and a through hole communicating with the preliminary material part is provided in the second molding mold to accommodate the piston. In addition, a through hole communicating with the product part is provided so that an insert support pin can be inserted thereinto, and the insert supported by the support pin can be positioned in the product part, and then the insert is inserted into the second mold. A third die plate, which can be assembled and transported, is provided for supporting the insert in the product section and for filling the product section and the pre-material section with rubber material in the lowered position of the piston; The mold is released from the second mold and transferred, and the mold is closed again at a predetermined position, thereby lowering the insert support pin and raising the piston. The insert support pin is detached from the insert contained therein, and the rubber material of the preliminary material section is press-fitted into the gap after the detachment using a piston, thereby making it possible to obtain the desired rubber product.

However, when using this device, it is possible to obtain a rubber product with an insert inside through a series of mechanical operations, which greatly improves workability, and it is also possible to obtain a product with good quality that completely includes the insert.

[Brief explanation of the drawing]

1 to 4 are diagrams showing the conventional manufacturing method, FIGS. 5 to 7 are diagrams showing the implementation steps of the method of the present invention, and FIG.
9 to 11 are diagrams showing rubber parts manufactured by the method of the present invention, and FIGS. 12 to 14 are diagrams showing a cross section of the device of the present invention and implementation steps, 15 and 16 are half plan views of the lower mold and die plate of the apparatus of the present invention, respectively, and FIG. 17 is a diagram showing a molded rubber part. 10...Plunger, 11...Insert, 2...Upper mold, 3...Middle size, 4
...Lower die, 40...Die plate,
5...Preforming mold, 61...Product section, 62...Preliminary material section 53...Insert support pin, 7...Piston , 8...
·guide pin.

Claims (1)

[Scope of Claims] 1. A second cavity communicating with the first cavity is formed between a mold having a first cavity for molding a target rubber part and a mold having an insert support pin. At the same time, the insert support pin is made to protrude into the first cavity, and with the insert supported by the insert support pin, the first cavity and the second cavity communicating therewith are connected to each other.
A preformed product is formed by filling a rubber material into the cavity of the first cavity containing the insert, and forming a preformed product consisting of a product part formed by a first cavity and a preliminary material part formed by a second cavity connected thereto, and the preformed product is solidified. The insert support pin is removed from the product part by moving the mold equipped with the insert support pin, and after removing the insert support pin, the mold is closed again, and the preliminary material part is pressed by pressure means. A method of manufacturing a rubber part having an interior insert, characterized in that a rubber material is pressurized and press-fitted into a gap in a product section after detachment of an insert support pin for compression molding. 2 The first cavity is where the desired rubber part is molded.
a first mold having a cavity, a second mold assembled to the first mold, and a third die plate assembled to the second mold and transportable.
A second cavity communicating with the cavity is formed between the first mold and the second mold, and the second mold communicates with the first cavity. A through hole that communicates with the first cavity and a through hole that communicates with the second cavity are provided, and an insert support pin is inserted into the through hole that communicates with the first cavity, and a piston is inserted into the through hole that communicates with the second cavity. Further, each rod portion of the support pin and the piston is wound with a spring, and the third mold, which can be transferred, is provided with the first mold provided in the second mold.
A through hole is provided at each orbital position of the through hole that communicates with the cavity of the second mold and the through hole that communicates with the second cavity, and the through hole that communicates with the second mold cavity that communicates with the second mold The tip of the insert support pin that supports the insert is inserted into the first cavity at a position where the through holes of the mold No. 3 are aligned, and at this position, the rubber material is inserted into the first cavity and the second cavity. After injecting into the cavity, the third mold is released and transferred to connect the through hole of the second mold communicating with the first cavity and the through hole of the third mold at the orbital position of the through hole. The mold is closed at the position where the holes match, and the piston in the through hole that communicates with the second cavity of the second mold is supported on the surface of the third mold, and with the biasing force of the spring. The interior insert has an inner insert configured to push the piston up into the second cavity so that the rubber material in the cavity is press-fitted into the gap formed in the rubber material in the first cavity after the insert support pin is detached. Rubber parts manufacturing equipment.