JPS58179629A - Manufacture of pipe joint made of plastic - Google Patents

Abstract

PURPOSE:To perform an injection molding of the ring grooved joint for fitting a rubber ring quickly and increase a production, by introducing a cooling medium in a mold and cooling the tip part of a cylindrical core and a diameter expanding step part of a core body. CONSTITUTION:A molten plastic material is injected and filled in the cavity 8 shaped by an outer mold and a core and a diameter expanded joint 9 is shaped. When a filling is finished, a cooling medium is passed through a spiral groove 14 by a hose 16 and the tip part 13a of a cylindrical core 11 and the surface of the diameter expanding step part 6a of a core body 6 are cooled. Then, when the cylindrical core 11 is parted, the opening end side 9a of a receptacle is deformed but immediately restored. The core body 6 is moved in the direction of an arrow C and the cooled diameter expanding step part 6a is stopped at the position of the opening and 9a of the receptacle and the hardening of the opening end part 9a is accelerated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an injection molding method for a flexible pipe joint, in which a socket provided at one end of a special V'C short my-t-shaped pipe is formed with an enlarged diameter. A ring s1!il- for attaching a rubber ring is formed on the inner peripheral surface of the opening side of the socket cavity to accommodate slight bends in the connecting pipe. It is designed so that it can be easily molded into an IC.

The molding method for the above-mentioned Pufsnak pipe fittings includes a secondary forming method in which the entire softened Defsnack pipe end is pushed into the mold, which is composed of a core mold and an outer mold;
There is an injection molding means for melting and press-fitting a thermoplastic resin into a cavity of an injection mold consisting of a lamp wick mold and an outer mold. However, in such a molding die, the groove for attaching the rubber ring becomes an undercut portion, so the core mold portion that molds the ring groove and its vicinity has the function of holding the diameter of the government metal while expanding and reducing the diameter. It is necessary to use a combination core mold that also has the function of being able to be removed. For this reason, conventional core molds are extremely complex, consisting of many parts, cannot withstand continuous use over long periods of time, and are prone to failure and maintenance. Also, the production cost is high, so it is possible to reduce the product cost and the processing cost completely! , there wasn't.

On the other hand, it is known that thermoplastic synthetic resins have a temperature range in which they can recover even if they are subjected to considerable deformation during the curing process after being shaped in a bath-molten state.
Here, this condition range is called the thermoelasticity range. If this characteristic is utilized, it is possible to form the trough line with a simple mold device having an undercut part, and in the fv1 elastic state range, the Kinsei-kai has the characteristic that even if it is removed from the mold by forcibly pulling it out while completely deforming the molding socket, it can be immediately restored and molded. Using this kind of thinking, for example, the first
When molding an annular grooved joint 1 for attaching a rubber ring as shown in the figure (partial cross-sectional side view), a core mold is used to ensure precision regardless of the primary molding or secondary & shaping. As the subsequent molding means, for example, an injection molding core mold as shown in FIG. 2 (partially sectional side view) is used. That is, the molding core mold 2 is equipped with a split outer mold Jfr button that regulates the outer circumferential surface of the joint l with a socket, and the expanding diameter part opening side regulating mold of the joint l is provided with the split outer mold Jfr button that regulates the outer peripheral surface of the joint l with a socket. A movable □ mold 5 is partially fitted with the VC, and the split outer mold 4 and the movable mold 5 constitute an outer mold. On the other hand, as for the core mold, the above-mentioned assembly is performed by forming a groove 8 inside the outer mold, and inserting the core metal main body 6 in the axial direction into the rubber ring of the joint l with a socket. The core mold for molding the mounting groove 1a (FIG. 1) is configured as a cylindrical core mold 7 that is fitted into the core mold body 6 and is slidable therein.

The movable mold 5 is configured to be detached from and retracted from the split outer mold 4 by operating rods 5m and 5a, and the cylindrical core mold 7 is provided with a sliding VC.

Further, a flange 7b is formed on one end side of the cylindrical core mold 7, and when the cylindrical core mold 7 is removed from the mold, the movable mold 5 is moved by hooking on the flange 7tl. ing. Note that 7a is a protruding portion for forming the annular groove portion.

On the other hand, the molding is carried out as shown in FIGS. 8 to 5 (a sectional view illustrating a partial operation in FIG. 2) VC. That is, as shown in FIG. 8, a bubble stick material is press-fitted into the cavity 8 in a bath melted state, and the enlarged diameter joint portion 9 is formed.

Next, especially the opening side of the enlarged diameter socket of the enlarged diameter joint part 9 is moved to the front mold 7. The copper of the movable mold 6 as shown in FIG. 5 is moved (arrow A').
Move the mold as indicated by arrow B. However, the inner diameter of the socket opening end 9a of the enlarged diameter joint part 9 is regulated by the regulating surface 7C shown by the dotted line in FIG. Alternatively, after curing, the core mold body 6 and the outer mold 4 are retracted and opened for molding.

However, in such a molding die, the entire mold is injection molded in a heated state, and cooling of the socket opening end (IlII9a, especially on the regulating surface 7C side) is delayed, and the restoring opening end side 9a is in a hot extrusion state. This prevents the temperature from falling below the 100% range and increases the waiting time for curing.Therefore, it has been pointed out that molding takes time and the cost of raw fish cannot be reduced.

The present invention has been made with attention to these points, and in particular, an injection molding method in which the injection molding mold is improved to actively cool the restoration regulating surface, thereby completely shortening the curing waiting time and increasing production. We try to provide everything. However, this invention consists of an outer mold consisting of an outer mold body and a cylindrical outer mold for molding the front part of the socket, and a core mold consisting of a core mold body and a cylindrical core mold for molding the socket. The cylindrical outer mold and the cylindrical core mold are used to maintain a high temperature fC on the socket part made of "Ranuchik material", and the outer mold is not removed, and then the cylindrical core mold is injected using Ark. In the method of ejecting and moving so that the front part of the socket is forcibly expanded, the inner peripheral surface of the cylindrical core mold is connected to the core mold body at a deep position of the socket. By passing cold water introduced from the communication hole provided in the core mold body into the formed groove, the depth of the receiving hole of the cylindrical core mold is 0.
The entire gist of this is to perform all demolding of the cylindrical core mold while keeping the socket opening side at a high temperature of 100 m and a low temperature at the open side of the socket.

The present invention will be described in detail below based on all the drawings, but the drawings show a specific example of carrying out the present invention, and the present invention is not limited to the illustrated mold, and within the scope of not departing from the gist of the present invention. It is also possible to carry out the same process with some specially designed molds. FIG. 6 (partially cut away side view) shows an example of the creation molding die 10 in which the present invention is fully implemented, and FIG. 7 (partially cutaway side view)
8 and 9 (partial cross-sectional views taken along line (2)) are diagrams for explaining the configuration, and FIGS. 8 and 9 (partial cross-sectional diagrams for explaining the operation in FIG. 6) are diagrams for explaining the forming process.

That is, in the injection molding die 1O in which the present invention is fully implemented, the split outer die 4 and the movable die 5 are constructed in the same manner as the example die 2, as shown in FIG. On the other hand, the core mold body 6 is formed to have a diameter p smaller than that of the mold for regulating the inner peripheral surface of the enlarged diameter socket of the diameter enlarged step part 6a for shaping the inner peripheral surface of the receiving slot opening part, and its axial length. Invade and form. [7] The cylindrical core mold has an annular groove portion 11a for attaching a rubber ring as shown by 11 in FIG. 6, and a sliding holding portion 12 of the moving mold 5 on the purple heating side,
The other side is configured as a cooling side 18, and the cooling side 1
The distal end 188k of the mold body 8 is formed as a thin beak portion that covers the enlarged diameter step portion 68 formed on the core mold body 6. The inner surface of the thin-walled portion of the beak, that is, the enlarged diameter stepped portion 6a of the core mold body 6
A spiral groove 14 is entirely formed on the joint surface side with the spiral groove 14.
is formed as a refrigerant circulation path. On the other hand, the introduction and discharge of the refrigerant communicating with this spiral groove 14 is carried out through a communication hole 15.15 opened in the enlarged diameter step portion 6a, and the communication hole 15. Both ends are connected to each other.

In order to ensure these connections, it is recommended that the core mold body 6 and the cylindrical core mold 11 be of a non-rotating sliding type.For example, a key may be provided on the core mold body 6. Then, cylindrical core mold 1
Completely form the ear grooves in 1 and assemble. Also, this communication hole 15
．． 15 communicates with passage holes 17 and 17 provided in the main body 6 of the core mold, respectively, and refrigerant circulation hoses 16 are connected to the passage holes 17, respectively. One side will be the introduction side and the other side will be the discharge side.

The method of the present invention using the injection molded metal mlO@ constructed as described above is carried out as follows. That is, as shown in FIG. 6, a molten plastic material is injected and filled into a cavity 8 formed by an outer mold and a core mold to form an enlarged diameter joint portion 9. During this formation, the entire mold is kept in a heated state. When the filling is completed, the refrigerant is passed through the spiral groove 14 by the hose 16 and the cylindrical core rXut is
The beak-shaped portion 1B & of the core mold body 6 and the surface starch of the enlarged diameter step portion 6a of the core mold body 6 are cooled. As a result, first, the enlarged diameter joint 9
It is possible to completely promote the softening of the thermoelastic clay on the open end side of the receiver. Then, the refrigerant circulation is completely stopped, and the entire mold 11 is demolded as shown in FIG. 8, so that the socket opening end 9a deforms as explained in FIG. 4 and immediately returns to its original state.

Next, in the present invention, the core mold body 6 is moved in the direction of the arrow C in FIG. 9, and the enlarged diameter stepped portion 68 is held at the position of the marking opening end 9a as shown in the figure.

However, since this enlarged diameter step part (as mentioned in iaIri) is cooled by the refrigerant Wi ring, when the restoring receiver opening lower part 9a comes into contact with the opening part 9m, this socket opening Since the movable mold 5 is in a heated state during the restoring abutment of 9a, even if it reaches the thermoelastic state region by leaving the movable mold 5, it will return to the thermoelastic state region again during this contact, or the hardened tip and By performing the injection molding at the enlarged diameter step of the core mold body 6, the injection molding of the annular grooved joint for attaching a rubber ring as shown in Fig. 1 can be performed quickly, increasing production and reducing costs. can contribute to the decline.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway side view showing an example of an annular grooved joint for attaching a rubber ring molded according to the present invention, Fig. 2 is a partially cutaway side view showing an example of a conventional injection mold for the same, and Fig. 8 , 4th
5 and 5 are cross-sectional views partially illustrating the operation of FIG. 2, FIG. 6 is a partially cutaway side view of the injection mold used in the present invention, and FIG.
The figure is a partial cross-sectional view taken along the cutting line 1g-6, and FIGS. 8 and 9 are partial cross-sectional views for explaining the operation of FIG. 6. l... Joint with ring groove for attaching rubber ring 2... Injection mold 4... Split outer mold 5...
・Movable mold 6...Core mold body 7...N tilted core mold 8...Cavidy 9...Expanded diameter joint part lO...Injection mold 11...Cylindrical core metal Mold 12...Heating part 18...Cooling part
14...Spiral groove 15...Continuous m hole 1
6... Honu 17... Passage hole applicant Kubota Tekko Co., Ltd. Procedural Amendment (Responsive Japan Patent Office Chief Examiner, Japan Patent Office Examiner)
■ Incident Display Showa S7 Patent Application No. 62282 Showa
Year Trial No. 3 Relationship with the person making the amendment Patent Representative Hiroshi Keitabe 4 Agent Postal code 530 Address 2-3-7 Dojima, Kita-ku, Osaka Shinko Hill Telephone Osaka (06) ) 343-2325 (main) 7
Each column of the contents of the amendment (υ "Scope of claims wtf" will be corrected in the attached document. (2) "High temperature" in the first line of page 7 of the specification will be corrected to "low temperature". (3 ) Corrected to "low temperature J't-r high temperature" in the negative second line of No. 7. (4) Corrected "softening" to "hardening" in page 9, No. 17t7 of the same. (2, Patent Scope of Claims (1) A rubber ring mounting groove fc, a Pufstick J!L!Iw joint for all sides of the socket?A cylindrical outer metal for injection molding, an outer mold body and a cylindrical outer metal for molding the front part of the socket. The outer mold consists of an outer mold, a core mold body and a hook-shaped core mold for socket molding, a socket part made of injected Buchstick material, and a front cylindrical shape. A method in which the outer mold 1 is removed while the outer mold and the cylindrical core mold are kept at a high temperature, and then the cylindrical core is discolored and the cylindrical core is removed and moved so that the front part of the socket is forcibly expanded. In this case, the refrigerant introduced from the communication hole provided in the core mold body is completely passed through the groove formed on the inner circumferential surface of the cylindrical core mold at the recessed position of the socket. A method for manufacturing a Puchstic pipe joint, characterized in that demolding of a cylindrical core mold is carried out with the receiving hole of the cylindrical core mold kept at a low temperature at 0111t and the open side of the cylindrical core mold at a high temperature. .

Claims (1)

[Claims] (1) Pufstik pipe joint with a socket with a groove for attaching a rubber ring.When performing full injection molding, an outer mold consisting of an outer mold body, a cylindrical outer mold for molding the front part of the socket, and a core metal. A state in which a core mold consisting of a mold body and a cylindrical core mold for socket molding is used, and a receiving part made of an injected plastic material is kept at a high temperature by the cylindrical outer mold and the cylindrical core mold. In this method, the outer mold 71 is removed from the mold, and then the cylindrical core mold is removed and moved so that the front part of the socket is forcibly expanded. By completely passing the refrigerant introduced from the communication hole provided in the core mold body into the concave groove formed on the inner circumferential surface side of the joint with the core mold body, the inner side of the socket of the cylindrical core mold A method for producing a Pufsnack pipe joint, characterized by demolding a cylindrical core mold while keeping the open side of the socket at a low temperature.