JP2922094B2 - Release agent application 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 release agent applying mechanism in a rubber hose extruder. More specifically, the present invention relates to a release agent applying mechanism for applying a release agent uniformly and continuously stably to the inner peripheral surface of unvulcanized rubber being extruded into a tube from an extruder.

[0002]

2. Description of the Related Art In general, a rubber hose used for a power steering hose or a fuel hose of an automobile is formed by bending a mandrel bent into a predetermined shape into an unvulcanized or semi-vulcanized (hereinafter, uncured). In this case, a rubber hose having an inner diameter substantially equal to the outer diameter of the cross section of the mandrel is inserted and closely fitted, and vulcanization molding is performed in this state.
At this time, insert the unvulcanized soft rubber hose into the bent mandrel smoothly and easily remove it after vulcanization molding. Is coated with a release agent. However, this method requires a step of separately applying a release agent to the inner surface of the rubber hose after the extrusion molding, which has led to an increase in the manufacturing cost of the rubber hose.

[0003] In order to solve this problem, it has been proposed to spray a release agent on the inner surface of an unvulcanized rubber hose being extruded. For example, 5-1
In the extrusion molding machine disclosed in Japanese Patent No. 6280, a communication path for supplying a release agent to a spindle in a die is provided,
A release agent is fed into the communication path from outside the molding machine by compressed air and sprayed from the tip of the spindle.
By doing so, the mold release agent is made to adhere to the inner peripheral surface of the extruded unvulcanized rubber hose in a mist state.

[0004]

However, since the extruder is of a straight head type, for example, the molding of the inner and outer surface layers of a composite rubber hose cannot be performed by a single extruder. However, when a high-viscosity release agent is used, there is a problem that spraying is not performed well. Further, there is a possibility that foreign matter may be clogged in the spray gun, the spray port at the tip of the spindle, or the like. Also,
If the hose has a small diameter, the spindle naturally has a small diameter,
There is a problem that it is difficult to incorporate them.

The present invention has been made to solve such a problem. The present invention is applicable to a wide range of viscosity of the release agent by sending the release agent in a liquid state to the application section. An object of the present invention is to provide a release agent applying mechanism capable of uniformly applying a predetermined amount of a release agent to the inner peripheral surface of a rubber hose without changing the state.

[0006]

SUMMARY OF THE INVENTION A release agent applying mechanism according to the present invention is a release agent in an extruder for forming a rubber hose by extruding unvulcanized rubber into a tube from a gap between a die and a tubular spindle. A mold application mechanism,
(A) a release agent supply pipe inserted into the cavity of the spindle; and (b) a release agent application pad fixed to the tip of the release agent supply pipe. A mold application pad having water absorbency and elasticity, and disposed near the tip of the spindle so as to be able to slide on the inner peripheral surface of the extruded tubular rubber; and (d) supplying the pad and the release agent. The tube is characterized in that it is adjustable in the axial direction of the spindle.

On the other hand, the release agent supply pipe is disposed substantially coaxially with the inner peripheral surface of the spindle via a sealing ring, and the release agent application pad is connected to the front end opening of the release agent supply pipe. It is formed so as to be closed, and when the rubber is extruded into a tube, the seal ring and the mold are separated between the outer peripheral surface of the release agent supply pipe, the inner peripheral surface of the spindle and the inner peripheral surface of the tubular rubber. Preferably, a cylindrical space defined by the agent application pad is formed, and an opening for discharging the release agent into the cylindrical space is opened on the side peripheral surface of the release agent supply pipe.

The release agent application pad is formed on the outer periphery of the tip end of the spindle, and the end of the release agent supply pipe is connected to the release agent application pad such that the cavity thereof communicates with the release agent application pad. Are preferred.

[0009]

According to the release agent application mechanism (hereinafter simply referred to as the application mechanism) of the present invention, a release agent application pad (hereinafter simply referred to as "supply tube") is supplied from outside the extruder through a release agent supply tube (hereinafter simply referred to as "supply tube"). If the unvulcanized rubber is extruded while being absorbed by the pad, the pad is in sliding contact with the inner peripheral surface of the extruded tubular rubber (hereinafter, simply referred to as a rubber hose). Of the release agent is uniformly applied to the inner peripheral surface of the rubber hose. Further, since the release agent is supplied in a liquid state, the viscosity of the release agent or the required application amount per unit area can be easily adjusted by changing the supply pressure of the release agent, for example.

Therefore, even if a high-viscosity release agent is used, uniform coating is possible.

Further, since a throat portion of the supply path for generating the mist of the release agent is not required and a relatively wide supply path can be used, even if some foreign matter or the like is mixed in the release agent. In addition, the supply path is not clogged.

Further, since the position of the pad can be adjusted in the axial direction of the spindle, the amount of the release agent applied to the inner surface of the rubber hose can be adjusted.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a coating mechanism according to the present invention.

FIG. 1 is a sectional view showing an embodiment of the coating mechanism of the present invention, FIG. 2 is a sectional view of a main part showing another embodiment of the coating mechanism of the present invention, and FIG. 3 is applied to the coating mechanism of the present invention. FIG. 4 is an explanatory diagram showing an example of a supply mechanism that can be used.

In FIG. 1, reference numeral 1 denotes a crosshead extruder, the head portion of which is shown. Reference numeral 2 denotes an extrusion screw, 3 denotes a die, 4 denotes a spindle, 5 denotes a crosshead, and 6 denotes a release agent supply pipe (hereinafter simply referred to as a supply pipe). A spindle 4 is coaxially incorporated inside the die 3, and an end opening (hereinafter, referred to as an end) of the die 3 forming an extrusion port.
The unvulcanized rubber is extruded into a tubular shape by the extrusion screw 2 from an annular gap between the extrusion port 7 and the tip of the spindle 4.

The extruded unvulcanized rubber hose H is wound up (see FIG. 3). Then, it is usually placed once on a predetermined tray, and then inserted into a mandrel and vulcanized.

As shown in FIG. 1, the spindle 4 is formed in a hollow shape, and a supply pipe 6 is inserted into a cavity 8 thereof. The rear end side (not shown) of the supply pipe 6 is connected to a release agent supply mechanism provided outside the extruder 1 on the right end side (not shown) of the crosshead 5 in the figure. (See FIG. 3). further,
The supply pipe 6 is configured to be moved in the axial direction of the supply pipe 6 by a moving mechanism (not shown) provided on the right end side of the crosshead 5.

Referring back to FIG. 1, the supply pipe 6 is
The ring 9 is fitted, and the outer peripheral side of the O-ring 9 is in close contact with the inner peripheral surface of the spindle support tube 10. At the tip of the supply pipe 6, a felt made of synthetic fiber is fixed with an epoxy resin adhesive or the like. This felt is the pad 11 for applying the release agent to the inner surface of the rubber hose H. The outer diameter of the pad 11 is substantially equal to the inner diameter of the rubber hose H to be extruded, and is attached so as to close the opening at the end of the supply pipe 6. Therefore, when the rubber hose H is extruded, the pad 11 slides on the inner peripheral surface of the rubber hose H, so that a narrow conical cylindrical closed space 12 on the outer surface is formed.

The release agent sent from the supply pipe 6 is discharged from the discharge port 13 formed in the supply pipe 6 into the cylindrical space 12, filled and absorbed by the pad 11. Discharge port 13
Is not particularly limited.

When the rubber hose H is extruded, the release agent absorbed in the cylindrical space 12 and the pad 11 adheres to the inner peripheral surface of the rubber hose H and the pad 1
1 is applied uniformly by sliding contact. Since the release agent in the pad 11 and the cylindrical space 12 decreases with the movement of the rubber hose H, a new release agent is continuously introduced from the supply pipe 6 due to the negative pressure.

As described above, since the supply pipe 6 is movable in the axial direction, the amount of the release agent applied to the inner surface of the rubber hose H can be adjusted. That is, when the supply pipe 6 is retracted in the crosshead direction, the portion of the cylindrical space 12 corresponding to the inner surface of the rubber hose becomes small, so that the amount of the release agent applied is reduced. This increases the amount of application.

FIG. 3 shows a mechanism for feeding the release agent into the extruder 1. A rubber hose H is extruded to the left of the crosshead 5, and a release agent is supplied from the right.
By providing an overflow pipe 15 in the release agent tank 14 and a return pipe 16 for returning the overflowed release agent to the release agent tank 14 by the pump 16a, the water level of the release agent is always kept at a predetermined position, for example, the cylindrical space 12. And can be kept at the same level. By doing so, it is possible to feed a predetermined amount of the release agent without using a means such as a pump. Therefore, the flow rate of the release agent can be easily adjusted by changing the water level in the release agent tank, and it can be applied to release agents having different viscosities and different rubber extrusion speeds. It can be easily accommodated by adjustment. of course,
In the present invention, the present invention is not limited to such a method. For example, a release agent feeding device such as a gear pump may be used.

The application mechanism shown in FIG. 2 is different from that shown in FIG. 1 in the shape and installation state of the supply pipe. That is, the spindle 17 has a straight tubular shape, and the supply pipe 19 is disposed inside the cavity 18 of the spindle 17 at a position off the axis. And the supply pipe 19
Is connected to the tip of the spindle 17. On the other hand, the pad 20 has a groove 2 along the outer periphery of the tip of the spindle 17.
1 and communicates with the tip of the supply pipe 19. By forming in this manner, the inside of the rubber hose H to be extruded and the cavity 18 of the spindle 17 are in communication. Therefore, the extruded rubber hose H
Even when the inside of the rubber hose is hermetically closed, for example, when the tip of the rubber hose is gripped, the inside of the rubber hose does not become negative pressure, and there is no danger of collapse.

Also in the present application mechanism, the spindle 17 can be moved in the axial direction. This coating mechanism (FIG. 2) is suitable for a large diameter hose molding machine.

The structure for preventing the negative pressure from being generated by connecting the inside of the rubber hose H to the cavity of the spindle is not limited to the structure shown in FIG. For example, a disk having a groove for accommodating a pad on a side periphery is attached to a tip of a spindle, and a release agent supply pipe is attached so that a cavity thereof communicates with the groove (the axis of the spindle may be passed). Various configurations can be adopted, such as providing a through hole for communicating the spindle cavity with the outside of the tip (hose cavity) using a disk.

In the present embodiment (FIGS. 1 to 3), the extruder to be applied is a crosshead type, but may be a straight head type.

[0027]

The coating mechanism of the present invention is applicable to a release agent having a wide range of viscosities. The coating state is not changed by a small amount of foreign matter, and a predetermined amount of the release agent is uniformly applied to the inner peripheral surface of the rubber hose. Can be applied.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a coating mechanism of the present invention.

FIG. 2 is a sectional view showing another embodiment of the coating mechanism of the present invention.

FIG. 3 is an explanatory view showing an example of a supply mechanism to which the coating mechanism of the present invention can be applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Extruder 3 Die 4, 17 Spindle 6 Supply pipe 8 Cavity 9 O-ring 11, 20 Pad 12 Cylindrical space 13 Discharge port 18 Cavity 19 Supply pipe

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B29C 47/20-47/28 B29C 47/94 B05C 1/06 B29C 33/58

Claims (3)

(57) [Claims] 1. A release agent applying mechanism in an extruder for forming a rubber hose by extruding unvulcanized rubber into a tube from a gap between a die and a tubular spindle, and comprising: (a) A release agent supply pipe inserted into the cavity, and (b) a release agent application pad fixed to the tip of the release agent supply pipe; and (c) the release agent application pad absorbs water. (D) the pad and the release agent supply pipe are arranged in the axial direction of the spindle so that the pad and the release agent supply pipe have an elasticity and an elasticity and can slide on the inner peripheral surface of the extruded tubular rubber. Release agent application mechanism that can be adjusted to move. 2. The release agent supply pipe is disposed substantially coaxially with a spindle inner peripheral surface via a sealing ring, and the release agent application pad is provided at the front end opening of the release agent supply pipe. It is formed so as to be closed, and when the rubber is extruded into a tube, the seal ring and the mold are separated between the outer peripheral surface of the release agent supply pipe, the inner peripheral surface of the spindle and the inner peripheral surface of the tubular rubber. The cylindrical space defined by the agent application pad is formed, and an opening for discharging the release agent into the cylindrical space is opened on the side peripheral surface of the release agent supply pipe. Release agent application mechanism. 3. The release agent application pad is formed on the outer periphery of the tip end portion of the spindle, and the end portion of the release agent supply pipe is connected to the release agent application pad so that its cavity communicates with the release agent application pad. The release agent applying mechanism according to claim 1.