JPH053203B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a CV cable connection method using an extrusion molding method, and in particular, a method for connecting CV cables using an extrusion molding method. This relates to a method of performing the process (without replacing the mold).

[Prior Art] If this method of continuously performing extrusion molding and crosslinking is adopted, the working time can be greatly shortened.

However, if one mold is simply used for both molding and crosslinking, (1) thermal expansion of the molded insulator during crosslinking cannot be absorbed;

(2) Difficult to control pressurization during crosslinking and subsequent cooling.

A problem arises.

Therefore, in order to solve the above problem, the following method has been proposed (Japanese Patent Application No. 59-222828).

In Figure 5, 10 is the cable core, and 12 is its connection part.

14 is a pressure cylinder for crosslinking.

Reference numeral 16 denotes a molding die, which is split into two, for example, and whose flanges 60 are connected with bolts 62 to form a mold. This bolt 62 is made of a material such as polypropylene that can withstand the heat and pressure during extrusion molding, but cannot withstand the heat and pressure during crosslinking and breaks.

First, the crosslinking agent-containing polyethylene 54 is extruded into the molding die 16.

Next, a high-pressure pressurized fluid 56 is introduced into the pressurized cylinder 14 and simultaneously heated to a required temperature to effect crosslinking.

At that time, as described above, the bolt 62 is broken, so there is no problem with the thermal expansion of the molded product, and the pressurized fluid 56 can enter the molding die 16, so that the molded product can be pressurized.

[Problems to be Solved by the Invention] In the above method, since the bolt 62 is gradually heated, it takes time to heat it to a state where it can be broken. During this time, the thermal expansion of the molded body continues, and there is a possibility that the internal pressure will increase. Also, bolts cannot be reused.

The present invention takes the above points into consideration and aims to provide a method that enables the reuse of necessary parts.

[Means for Solving the Problems] As shown in FIGS. 1 to 4, the present invention provides the following features: (1) A split is made in at least one place so that the entire or part of the molding die 16 can be opened and closed. (2) A fluid pressure cylinder 38 is provided on one side of the cracked part so that the pressurized fluid can enter the inside and pressurize the molded body when it is opened.
is fixed, and a receiving plate 50 is provided on the other side, the mold 16 is closed, and the rod 42 of the hydraulic cylinder is fixed.
(3) When pressurized fluid enters the pressurized cylinder 14, the pressurized fluid enters the cylinder chamber. 47, and the rod 42 is moved backward by the force thereof, thereby releasing the lock. "The mold can be opened and closed freely."
As in the example below, you can split the mold into two and hinge one side, or if the entire mold is made of an elastic material such as metal, the mold can be split in only one place and the metal This means that it may be opened and closed using its elasticity.

Furthermore, "the entire mold or a part of the mold can be opened and closed" means that when the mold is made of one shell, as in the case of Fig. 5 above,
This means that the entire mold, or when the mold is made of a plurality of layers as in the examples described later, a part of the mold can be opened and closed.

[Example] In FIGS. 2 and 3, 14 is a pressure cylinder for crosslinking, which is the same as the conventional one.

Reference numeral 16 denotes a molding die, which in this case is composed of an elastic tube 18 and a molding cylinder 20, which will be described below.

The elastic tube 18 is made of a material that can withstand the heat of crosslinking, such as crosslinked polyethylene. Its inner surface shape is the same as that of the reinforcing insulator.

Polyethylene 54 is extruded inside this,
During crosslinking, the molded body is pressurized from the outside.

The molding tube 20 is cylindrical.

This is divided into two halves, for example, a left half 24 and a right half 26, and one side of them is attached to a hinge 3.
0 and can be opened and closed freely.

Note that the left and right and front and back are determined as indicated by arrows 28 in FIG.

The shaping tube 20 serves to maintain the shape of the elastic tube 18. Therefore, it is made of a material that can withstand the pressure during molding, such as iron.

32 is a locking means for the molding cylinder 20, and this portion is shown enlarged in FIGS. 1 and 4.

34 is a metal fitting for attaching the cylinder, and the molding cylinder 2
It is fixed at the left half 24 of 0. It also has a round hole 36 in the cable axis direction.

38 is a hydraulic cylinder, which is fixed to the metal fitting 34.

40 is that piston.

42 is a rod that passes through the above-mentioned round hole 36.

A chamber 44 on the head side of the hydraulic cylinder 38 communicates with the outside of the pressurizing cylinder 14 through a pipe 46, or is sealed. Further, the chamber 47 on the rod side communicates with the space inside the pressurizing cylinder 14 through a small hole 48 (the role of these will be described shortly).

Reference numeral 50 denotes a receiving plate, which is fixed to the right half 26 of the molding cylinder 20. It has a tapered hole 52 into which the tip of the rod 42 fits.

- Action of only the locking means 32: By combining the left half 24 and the right half 26, the forming cylinder 2
Close 0.

Advance the rod 42 and insert the receiving ring 50 at its tip.
into the hole 52. As a result, the closed state of the molding cylinder 20 is locked.

Next, when the pressurized fluid 56 enters the pressurized cylinder 14, the pressurized fluid 56 enters the chamber 47 through the small hole 48,
Move the rod 42 backward.

Therefore, the tip of the rod 42 comes out of the hole 52, the lock is released, and the molding tube 20 can be opened freely.

[Overall operation] (1) Extrusion molding After connecting the cable core 10, the molding die 16 is assembled thereon, and the locking means 3 is assembled as described above.
Lock 2.

Then, the pressurizing cylinder 14 is assembled thereon.

High pressure air is sent into the hydraulic cylinder 38 through the pipe 46 to prevent the rod 42 from coming out of the receiver 50.

Then, the polyethylene 54 is press-fitted into the molding die 16.

(2) Bridging and cooling The chamber 44 on the head side of the hydraulic cylinder 38 is opened to the atmosphere through a pipe 46.

A pressurized fluid 56 (eg, silicone oil) is introduced into the mold 16 and simultaneously heated by suitable means. Then, as described above, the lock is released and the molding die 16 can be opened and closed.

When the molded insulator inside the molding die 16 thermally expands, the force opens the molding die 16 and applies pressure through the elastic tube 18 .

Cooling is also performed in this state.

[Another Embodiment] (1) When using a plurality of locking means 32, in order to ensure the operation of each hydraulic cylinder 38, a second locking means 32 is used.
As shown in the figure, the rods of each cylinder are connected by rods 58.

(2) Instead of feeding high-pressure air through the pipe 46 to prevent the rod 42 from coming out, a spring (not shown) may be inserted into the rod 44 to achieve the same effect.

[Effects of the Invention] A split is made in at least one place so that the whole or a part of the molding die can be opened and closed, and a fluid pressure cylinder is fixed to one side of the split part,
In addition, a receiving metal is provided on the other side, the mold is closed,
When the rod of the fluid pressure cylinder is advanced, the tip of the rod enters the receiver to lock the closed state of the mold, and when pressurized fluid enters the pressurized cylinder, it flows into the cylinder. The rod is moved back by the force and the lock is released. (1) During crosslinking, the closing lock of the mold 16 is automatically released. Therefore, the molded body can be pressurized and its thermal expansion can be absorbed without any problem.

(2) The locking means 32 can be used repeatedly.

[Brief explanation of drawings]

1 to 4 relate to embodiments of the present invention,
1 is an explanatory diagram showing a horizontal cross section of the locking means 32 and its vicinity, FIG. 2 is an explanatory diagram of the whole, FIG. 3 is a cross-sectional view taken at - in FIG. 2, and FIG.
A perspective view of the part No. 2, FIG. 5 is an explanatory view of the prior art, and a cross section of the negative portion is shown in FIG. 6. 14: Pressure tube, 16: Molding die, 18: Elastic tube, 20: Molding tube, 32: Locking means, 3
8: Hydraulic cylinder, 42: Rod, 48: Small hole,
50: Receiver, 54: Polyethylene, 56: Pressurized fluid.

Claims (1)

[Scope of Claims] 1. A mold for molding is housed in a pressurizing cylinder for crosslinking, and after extruding polyethylene containing a crosslinking agent into the molding mold, A method for connecting a CV cable, in which a pressurized fluid is introduced, the fluid penetrates into the inside of the molding die, and the molded body is heated and crosslinked while being pressurized by the fluid, the method comprising: A split is made at a location so that the entire mold or a portion thereof can be opened and closed, and when the mold is opened, the pressure fluid can penetrate into the inside and pressurize the molded object, A fluid pressure cylinder is fixed on one side of the cracked part, and a receiver is provided on the other side, and when the mold is closed and the rod of the fluid pressure cylinder is advanced,
The tip of the pressurized fluid enters the receiver to lock the closed state of the mold, and when the pressurized fluid enters the pressurized cylinder, it also enters the cylinder and its force causes the rod to close. 1. A method for connecting a CV cable, characterized in that the lock is released by moving back.