JPH0686085B2 - Vent port opening / closing device of injection molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a vent port opening / closing device for an injection molding machine.

(Prior Art) In the injection molding machine industry, in recent years, diversification of injection molded products has forced production of a wide variety of products in small quantities, and the chances of resin replacement and color replacement are increasing. Therefore, purging for resin change and color change of the injection molding machine is a short time, and minimizing the amount of purging resin is an important issue for saving raw materials.

It has been known that it is effective to increase the internal pressure in the measuring process for purging as a means of efficient resin change and color change. It has also been confirmed that it has the effect of quickly scraping off old resin.

(Problems to be Solved by the Invention) However, since the vent-type injection molding machine has a vent hole in the barrel, various means have been proposed because a means for closing the vent hole at the time of resin change or color change is required. .

However, when the resin used in the vent-type injection molding machine is heated and melted in the barrel, high-pressure volatile components are generated. In some cases, the plug receives a strong force due to abnormal internal pressure, and there is a high possibility that an accident will occur due to damage and scattering of the members that make up the plug and the mounting bolts that mount the plug. There was a need to develop a vent port opening / closing device with a simple structure that can easily handle opening / closing of vent holes.

[Structure of Invention]

(Means for Solving the Problem) A vent port opening / closing device for an injection molding machine according to the present invention is a vent port opening / closing device in which a vent hole formed in a barrel of an injection molding machine can be opened to an airtight space portion. Has a gap in the vent hole, and a portion following the tip end is formed so as to completely close the vent hole, a vent port surrounding the vent hole, and an upper end of the vent port. A vent port lid that is also provided at the center of the vent port lid, and a member that is provided by being fitted in the penetration portion of the vent port lid and that guides the vent plug forward and backward; A bearing provided on the upper end of the port lid for holding the base end of the vent plug, an arm having one end swingably connected to the base end of the vent plug via a first connecting pin, and a predetermined bearing for the bearing. Angle rotation A handle that is rotatably attached and that the other end of the arm is swingably connected through a second connecting pin and that opens and closes the vent plug through the arm by turning by the predetermined angle; and the vent plug. It is interposed at any part of itself and the part from the vent plug to the barrel through the arm, handle and bearing, and enables relative movement of the vent plug in the opening direction when the vent plug is closed. The movable part and an elastic member that prevents relative movement of the movable part until a predetermined barrel internal pressure acts on the vent plug provided in the movable part.

(Operation) With the configuration as described above, opening / closing of the vent plug is performed by advancing / retreating the vent plug via the arm by turning the handle, and when operating with the vent plug closed, in the weighing process. When an abnormal internal pressure occurs in the barrel due to the pressure of the volatile component generated from the molten resin, the vent plug is pushed up in the direction of opening the vent hole against the elastic member. At that time, the tight fitting part between the vent plug and the vent hole is disengaged, and a gap is created between the vent plug and the vent hole. Volatile components leak from this gap into the vent port, reducing the abnormal internal pressure and preventing accidents. can do.

(Embodiment) A first embodiment of the present invention will be described below with reference to FIGS. 1 to 6.

In FIG. 1, reference numeral 1 is a barrel, and 2 is a screw fitted into the barrel 1, which is rotated by a driving device (not shown) and is moved back and forth in the axial direction. Reference numeral 3 denotes a vent hole formed in the barrel 1, which opens substantially tangentially to the inner diameter of the barrel (rightward in the drawing).

The vent port 4 has a bottom portion 6 fixed to the barrel 1 with a bolt 8 so as to form an airtight hollow portion 5 surrounding the vent hole 3.

Vent port lid 7 provided on the upper end of the vent port 4
A bearing 10 of an opening / closing device 9 having a mechanism for opening / closing a vent plug 13 to be described later with respect to the vent hole 3 is provided on the upper part of the bearing 12 via a spring spring 11 as an elastic member, as shown in detail in FIG. Is attached so as to be movable in parallel with the vent plug 13 and elastically.

FIG. 2 is a sectional view of the vent port 4 and the opening / closing device 9,
The opening / closing device 9 shows a state in which the vent plug 13 opens the vent hole 3.

In FIG. 2, a tip portion (hereinafter referred to as a loose fitting portion) 14a of the vent plug 13 is formed into a shape that creates a gap between the vent hole 3 and the vent hole 3, and a close fitting portion 14b at the next stage has a vent hole 3 It is formed in a shape that perfectly fits the vent hole 3 so that it fits tightly into the bottom hole and acts as a plug.

Further, the tip end 15 has an arc shape so as to match the inner surface of the barren when the vent hole 3 is closed. Vent plug in Fig. 6
Details of the tip of 13 are shown.

Bush with an O-ring 17 inserted in the vent port lid 7.
16 is attached and slidably supports the central portion of the vent plug 13.

The base end side of the vent plug 13 is provided with an arm 19 via a first connecting pin 18.
It is connected to one end (see FIGS. 4 and 5).
The other end of the arm 19 is connected to the boss 25 of the handle 21 by the second connecting pin 20.

The handle boss 25 is rotatably attached to the bearing 10 about a shaft 22 provided at the center thereof, and a rotary lever 26.
The rotation is given by. Reference numeral 23 denotes a first lock pin for locking the rotation of the handle 21, which is attached to the bearing 10 so as to penetrate the handle boss 25 and be removable. In this embodiment, the handle is at the position shown in FIG.
It is used only when there is 21, so that the handle 21 does not rotate due to other careless force. Reference numeral 24 denotes a stopper, which opposes one end of an outer peripheral stepped portion 25a having a small diameter of about 180 ° on the outer periphery of the handle boss 25, and regulates the rotation angle of the handle boss 25. When the handle boss 25 is locked by the first lock pin 23, a slight gap is formed between the stopper 24 and one end of the outer peripheral step portion 25a. When the first lock pin 23 is inserted, , The hole on the side of the handle boss 25 is easy to find.

As shown in FIG. 2, when the handle 21 is in the counterclockwise turning limit position in FIG. 2, the second connecting pin 20 is located at the bottom dead center side with respect to the vent plug 13, and the vent plug 13 is vented. It is constructed so as to be pulled out from the hole 3 and at a position which is swung by δ counterclockwise from the extension of the straight line connecting the first connecting pin 18 and the shaft 22.

Next, referring to FIG. 3, FIG. 3 shows a state in which the vent plug 13 of the opening / closing device 9 closes the vent hole.

As shown in FIG. 3, the handle 21 is rotated by the rotation lever 26.
Is rotated approximately 180 ° from the state of FIG. 2 to the position of FIG. 3 in the clockwise direction by approximately 180 °, one end of the outer peripheral step portion 25a of the handle boss 25 comes into contact with the stopper 24, and the handle boss 25
The rotation angle of the is clockwise is regulated.

At this time, the second connecting pin 20 is on the top dead center side, and
It is configured so as to be located at a position which is rotated clockwise by δ from the straight line connecting the connecting pin 18 and the shaft 22 as shown in the drawing.

Reference numeral 27 is a liner, and in this state, the position of the tip end 15 of the vent plug 13 is adjusted according to the position of the inner diameter portion of the barrel 1.

Next, the operation of this embodiment will be described.

The opening and closing of the vent hole 3 is performed by rotating the rotation lever 26 as shown in FIGS. 2 and 3. First, as shown in FIG. 3, the first lock pin 23 that locks the rotation of the handle 21 is removed, and the handle 21 is moved clockwise from the state shown in FIG. 2 to the position shown in FIG. 3 by the lever 26 for rotation. When rotated 180 °, the vent plug 13 closes the vent hole 3, and one end of the outer peripheral step 25a of the handle boss 25 is stopped by the stopper 2
It contacts with 4 and regulates the rotation angle of the handle 21 in the clockwise direction. In this state, when the internal pressure of the barrel 1 becomes high, the pressure causes a force to push back the vent plug 13. The force tries to rotate the handle boss 25 about the shaft 22 via the first connecting pin 18, the arm 19, and the second connecting pin 20, but the second connecting pin 20 moves as shown in FIG. Since it is located at a position that is rotated clockwise by δ from the straight line connecting the connecting pin 18 and the shaft 22,
The rotation of the handle boss 25 is blocked by the stopper 24. Therefore, the force to push back the vent plug 13 is the handle boss 25,
It acts on the bearing 10 as it is via the shaft 22 and the stopper 24, and pushes the bearing 10 up against the flat spring 11 from the vent port lid 7. At that time, the vent plug 13 is lifted by the amount of compression of the flat spring 11, and the close fitting portion 14b of the vent plug 13 and the vent hole 3 are disengaged so that the loose fitting portion 14a is fitted in the vent hole 3. Become. Therefore, the vent hole 3 and the loose fitting portion
The pressure generated at the vent portion is released into the vent port 4 through the gap with 14a. In this embodiment, an example is shown in which the opening / closing device 9 is opened / closed manually, but it is not necessary to manually
It may be opened and closed by hydraulic means.

Next, a second embodiment will be described with reference to FIGS.

The difference from the first embodiment lies in the system in which the rotation amount of the handle 21 is restricted and locked. Various methods are conceivable for restricting and locking the turning amount of the handle 21, one of which is the second lock pin 30 adopted in this embodiment (details are shown in FIG. 12).
There is a method to use, the plunger of the second lock pin 30
32 is pressed against a fitting hole 28 formed in the handle boss 25 by a built-in spring 33 or the like.
The lock pin 30 restricts the rotation of the handle 21. A second lock pin 30 is attached to the bearing 10, and a tip end plunger 32 of the second lock pin 30 is constantly pressed into a fitting hole 28 of a handle boss 25. Only when the handle 21 is rotated-that is, when the vent plug 10 is lifted to open the vent hole 3 and when the vent hole 3 is lowered to close the vent plug 3 with the vent plug 3, the plunger 32 of the second lock pin 30 is turned by the knob 31. Knob 3 after retracting for a while and rotating about 180 °
When 1 is released, the plunger 32 is pressed against the fitting hole 28 of the handle boss 21 by the spring 33, and the rotation of the handle boss 21 is restricted. Further, a third embodiment will be described with reference to FIG. This is also related to the method of restricting and locking the rotation amount of the handle 21, and the stopper 24 shown in the first embodiment.
Instead of this, a bearing wall 29 formed on the bearing 10 is used. At this time, the handle boss 25 has a shape as shown in FIG.

In this embodiment, the second connecting pin 20 is provided so as to be displaced by δ in the clockwise direction (in FIG. 13) from the line connecting the first connecting pin 18 and the shaft 22. The handle boss 25 inevitably rotates to the right due to the force that pushes up the vent plug 13, so that the handle boss 25 comes into contact with the bearing wall 29, and the rotation of the handle boss 25 is restricted. The bearing 10 receives the force that pushes up the vent plug 13.

In the above-described embodiment, the vent plug 13 is controlled by the internal pressure of the barrel 1.
Although an example of moving the bearing 10 against the spring spring 11 has been shown to push up, the invention is not limited to this, and the vent plug 13 can be expanded and contracted and an elastic member corresponding to the elastic spring 11 is interposed. The push-up allowance portion interposing this elastic member may be interposed at any portion between the vent plug 13 and the vent port lid 7, such that only the tip side of the vent plug 13 may be pushed up. Needless to say.

〔The invention's effect〕

According to the present invention, the vent hole can be easily opened and closed by the handle, and at the same time, when an abnormal internal pressure occurs in the vent portion, the pressure can be appropriately released,
It is possible to prevent breakage of the member that constitutes the vent port and scattering accident of the mounting member.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention, FIG. 2 is a sectional view of FIG. 1 with a vent plug open, and FIG. 3 is the same as FIG. FIG. 4 is a cross-sectional view showing a state in which the vent plug is closed, FIG. 4 is a partial view taken along line AA of FIG. 1, and FIG.
1 is a top view of FIG. 1, FIG. 6 is a detailed view of the tip of a vent plug, FIG. 7 is a configuration diagram showing a second embodiment, and FIG. 8 is a sectional view of FIG. Fig. 9 shows the state when
FIG. 7 is a sectional view similar to FIG. 7 with the vent plug closed, FIG. 10 is a partial view taken along the line AA of FIG. 7, FIG. 11 is a top view of FIG. The figure shows the fitting diagram of the second lock pin,
FIG. 13 is a block diagram showing the third embodiment. 1 ... Barrel, 2 ... Screw, 3 ... Vent hole, 4 ... Vent port, 5 ... Airtight cavity, 6 ... Bottom, 7 ... Vent port lid, 8 ... Bolt, 9 ... Switchgear, 10 ... Bearing, 11 ... Sara spring (elastic member), 12 ... Bolt, 13 ... Vent plug, 14 ... Tip part, 14a ... Free fitting part, 14b ... Close fitting part, 15 ... cutting edge, 16
...... Bush, 17 …… O ring, 18 …… First connection pin, 19 …… Arm, 20 …… Second connection pin, 21 …… Handle, 25a …… Outer peripheral step, 22 …… Shaft, 23… … First lock pin, 24 …… Stopper, 25 …… Handle boss, 26 …… Rotating lever, 27 …… Liner, 28 …… Mating hole, 29 …… Bearing wall, 30 …… Second lock pin, 31 …… Knob, 32 …… Plunger, 33 …… Spring.

Claims (1)

[Claims] 1. A vent port opening / closing device in which a vent hole formed in a barrel of an injection molding machine can be opened to an airtight space, wherein (a) a tip portion is fitted in the vent hole with a clearance. The part following the tip part is a vent plug formed so as to completely close the vent hole, (b) a vent port surrounding the vent hole, and (c) provided at the upper end of the vent port, and at the center thereof. A vent port lid having a penetrating portion that fits into the vent plug; (d) a member that is fitted into the penetrating portion of the vent port lid and that guides the vent plug forward and backward (e) the vent port A bearing provided on the upper end of the lid for holding the base end of the vent plug; and (f) an arm whose one end is swingably connected to the base end of the vent plug via a first connecting pin. ) The bearing can be swung to a specified angle. A handle attached to the other end of the arm so as to be swingable via a second connecting pin, for opening and closing the vent plug through the arm by turning the arm at a predetermined angle; and (h) the vent plug. A movable member that is interposed at any part of itself and the portion from the vent plug to the barrel via the arm, handle, and bearing to enable relative movement in the opening / closing direction of the vent plug when the vent plug is in a state. And an elastic member that prevents relative movement of the movable portion until a predetermined barrel internal pressure acts on the vent plug provided in the movable portion. Vent port switchgear.