KR20170043334A

KR20170043334A - Valve apparatus for an inclined gate of a hot runner injection mold

Info

Publication number: KR20170043334A
Application number: KR1020150142958A
Authority: KR
Inventors: 허남욱
Original assignee: 허남욱
Priority date: 2015-10-13
Filing date: 2015-10-13
Publication date: 2017-04-21
Also published as: KR101769207B1

Abstract

In particular, the gate 22 of the hot runner injection mold is inclined at a predetermined angle with respect to the surface 13a of the cavity 13, and the molten resin of the runner 41 on the side of the manifold 40 A nozzle portion 30 having a valve pin hole 33 and a molten resin passage 31 for guiding the molten resin to the cavity 13 is inserted into the fixing die 11 and the inlet 22a of the gate 22, And an outlet 31b of the molten resin passage 31 are inserted into the valve pin hole 33 in the hot runner injection mold opened in the inner wall of the valve pin hole 33, Is lifted up and down by the vertical movement of the first piston 70 and is rotated by the cam mechanism constituted by the cam pin 55 and the cam track 53 and the up and down movement of the second piston 80, The gate 22 is opened and closed.

Description

VALVE APPARATUS FOR AN INCLINED GATE OF HOT RUNNER INJECTION MOLD

The present invention relates to a gate valve apparatus for opening and closing a gate of a hot runner injection mold, and more particularly, to a gate valve apparatus for opening and closing a gate of a hot runner injection mold, in which a gate is inclined with respect to a cavity surface so that molten resin is injected with a gentle inclination relative to the surface of the gate, To a rotary gate valve device which opens and closes by a rotary valve pin that is vertically lifted and lowered and operated to rotate by operation of a cam mechanism and a double piston mechanism.

Generally, as disclosed in Patent Documents 1 and 2 below, a cavity is formed between an upper mold and a lower mold, and the cavity is opened when the lower mold is separated from the parting line, When it is combined with the mold, it is sealed. A gate for injecting the molten resin into the cavity is provided at the lower end of the upper mold constituting the upper side wall of the cavity. The upper mold is provided with a nozzle mechanism in which a resin passage for guiding the molten resin supplied through the runner of the manifold into the cavity through the gate is formed inside the body. A gate valve device for opening and closing the gate is also provided. The gate valve device is composed of a valve pin installed vertically and slidably through the nozzle, and a cylinder mechanism moving the valve pin up and down so that the tip portion of the lower end of the valve pin opens and closes the gate.

In the above-described conventional hot runner injection mold apparatus, the gate is formed in a direction substantially perpendicular to the surface of the cavity, and a molten resin injected into the cavity through the gate at a high pressure is injected onto the surface of the molten resin filled in the cavity The collision causes a ripple on the surface of the molten resin filled in the cavity, and the ripples on the surface cause a poor injection to form a flow mark on the molded product after completion of injection molding.

JPH07-251429 JPP2015-63110

The present invention has been made to solve the above-mentioned problems of the conventional injection mold apparatus, and it is an object of the present invention to provide a molten resin injected into a cavity, in which a gate is provided in a direction inclined with respect to the surface of the cavity And a gate valve device capable of opening and closing the inclined gate.

According to an aspect of the present invention,

And a nozzle portion provided with a molten resin passage and a valve pin hole for guiding the molten resin of the manifold side runner to the cavity side and being inserted into the fixed die, And the gate of the molten resin passage is opened and closed in a hot runner injection mold which is opened at a lower side wall of the valve pin hole,

Wherein the gate valve device includes: a valve pin slidably installed in the valve pin hole, the valve pin having a connection passage for connecting an outlet of the molten resin passage and an inlet of the gate to each other; And a double piston mechanism composed of a first piston for moving the valve pin upward or downward in the longitudinal direction and a second piston for slidably moving up and down relative to the valve pin; And a communication position in which the connecting passage of the valve pin communicates the outlet of the molten resin passage with the inlet of the gate and a connecting position where the connecting passage of the valve pin communicates with the melting position And a cam mechanism that converts the rotation of the valve pin into a rotation operation of reciprocating rotation between an outlet of the resin passage and a blocking position for blocking the inlet of the gate.

The cam mechanism includes at least one cam pin fixed to the second piston so as to protrude in the radial direction from the second piston toward the outer circumferential surface of the valve pin and at least one cam pin fixed to the outer surface of the valve pin at a predetermined helical angle, It is characterized by the inclusion of a slidably received helical groove.

The lower end side wall of the valve pin linearly moves to an upper limit position where the gate inlet is opened and the outlet of the molten resin passage is closed at the same time when the first piston rises to the upper limit position, The lower side wall of the valve pin linearly moves to a lower limit position where the gate inlet and the outlet of the molten resin passage are closed.

When the second piston moves to the lower limit position, the outer circumferential surface of the valve pin is rotated to a position where it blocks the outlet of the molten resin passage and the gate inlet, and when the second piston moves to the upper limit position, And the pin is rotated by the cam mechanism to a position where the connecting passage of the valve pin communicates with the outlet of the molten resin passage and the inlet of the gate.

According to the gate valve device of the hot runner injection mold of the present invention, the molten resin injected into the cavity through the gate is injected obliquely to the surface of the molten resin of the cavity, so that ripples are formed on the surface of the molten resin filled in the cavity As a result, it is possible to prevent occurrence of injection molding defects such as flow marks in the molded product.

The gate valve device of the present invention opens and closes the gate while the valve pin rotates by the two-stage operation of the double piston by the cam mechanism, so that it is possible to open and close the gate formed obliquely from the side of the valve pin.

1 is a partial cross-sectional view of a hot runner injection mold equipped with a gate valve device of the present invention,
2 is an enlarged detail view of the portion " A " of Fig. 1,
3 is a partially enlarged perspective view of a valve pin having a spiral groove formed on an outer peripheral surface thereof,
4 to 6 are partial cross-sectional views showing, in step-by-step, operational states of the gate valve device of the present invention,
4 is a sectional view showing a state in which the valve pin is lowered to the lower limit position by the lowering operation of the first piston and the lower end outer surface of the valve pin blocks the outlet of the molten resin passage and the inlet of the gate,
Fig. 5 is a cross-sectional view of the valve according to the present invention. Fig. 5 is a cross-sectional view of the valve pin shown in Fig. 4, in which the valve pin is axially rotated by the upward movement of the second piston, Sectional view showing a state in which the molten resin is injected,
6, in the state of FIG. 5, the valve pin is reversely rotated by the lowering operation of the second piston, so that the lower end outer surface of the valve pin blocks the outlet of the molten resin passage and the inlet of the gate Sectional view showing a state in which the end of the gate is cut.

Hereinafter, preferred embodiments of a gate valve device of a hot runner injection mold according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a partially assembled cross-sectional view of a hot runner injection mold equipped with a gate valve device of the present invention. As shown in FIG. 1, the hot runner injection mold includes an upper fixing die 11 and a lower movable die 12. The movable die 12 forms a cavity 13 with the fixed die. A gate 22 inclined at a predetermined angle with respect to the surface 13a of the cavity 13 is formed on the bottom surface of the fixed die 11 in contact with the surface 13a of the cavity 13. [ 1, the gate 22 may be formed in the gate block 21 assembled on the bottom surface of the fixed die 11, but it may be formed by machining directly on the bottom surface of the fixed die 11 It is possible.

1 and 2, it is preferable that the gate 22 is formed as a curved surface having a gently convex shape on the upper side wall of the passage. As the molten resin passes through the gate 22, it flows into the cavity without resistance along the curved surface of the gate 22, thereby improving the melt flowability through the gate.

The fixed die 11 is provided with a molten resin passage 31 through which an inlet 31a communicates with the runner 41 of the manifold folder 40 and guides the molten resin supplied from the runner 41 of the manifold, A nozzle portion 30 formed separately from the molten resin passage 31 is provided in the longitudinal direction so that the valve pin hole 33 in which the pin 50 is slidably mounted is provided. On the upper side of the manifold 40, there is provided an upper plate 60 provided with a double piston mechanism to be described later.

1 and 2, the gate valve device of the present invention is slidably installed in the valve pin hole 33 and has an outlet 31b of the molten resin passage 31, A valve pin (50) having a connecting passage (51) for communicating the inlet (22a) of the gate (22) with each other; The upper end of the valve pin 50 is connected and the compressed air is supplied to the upper first chamber 71 through the first flow path 61 so that the lower end of the valve pin 50 is moved to the lower- The lower end of the valve pin 50 is moved upward to the upper limit position by supplying the compressed air to the lower second chamber 72 through the second flow path 62, A first piston 70 which is slidably moved along the longitudinal direction of the valve pin 50 and which is connected to the third chamber 81 on the upper side via a third flow path 63, And the second piston 80 is moved up to the upper limit position by supplying compressed air to the lower fourth chamber 82 through the fourth flow path 64 A double piston mechanism constructed; And the second piston (80) reciprocates linearly when the second piston (80) linearly reciprocates between the upper limit and the lower limit, the connecting passage (51) of the valve pin (50) And the inlet 22a of the gate 22 and the outlet 31b of the molten resin passage 31 and the inlet 22a of the gate 22, Into a rotating operation of the valve pin (50) rotating reciprocally between the blocking positions.

1, the cam mechanism includes a pair of cam pins (not shown) fixed to the side wall of the second piston 80 so as to protrude in the radial direction from the second piston 80 toward the outer peripheral surface of the valve pin 50 And a cam track 53 accommodated in the cam track 55 so that the tip of the cam pin 55 slidably moves. The cam track 53 is formed by the first piston 70, The valve pin 50 also has a straight groove 53a formed in the longitudinal direction on the outer circumferential surface of the pin so as to move together with the up and down reciprocating movement of the second piston 70 when the piston reciprocates linearly in the longitudinal direction, And a helical groove 53b formed at a predetermined helical angle on the outer circumferential surface of the valve pin 50 so that the valve pin 50 rotates when the valve pin 50 is lifted and the tip end of the cam pin 55 is slidably received .

Therefore, when the second piston 80 is lifted or lowered, the cam pin 55 also moves up or down together with the valve pin 55, which slidably receives the tip of the cam pin 55 in the spiral groove 53b of the outer circumferential surface, The cam 50 rotates along the spiral direction of the helical groove 53b as the cam pin 55 ascends. At this time, since the valve pin 50 does not move vertically by the stopped first piston 70, the valve pin 50 does not move in the vertical direction but rotates.

Hereinafter, the operation of the gate valve device having the above-described configuration will be described.

(I) Pre-production phase (Figure 1)

1 shows a state in which the lower end of the valve pin 50 connected to the first piston 70 is located at the upper limit position H1 in the valve pin hole 33 and the upper limit The lower side wall of the valve pin 50 at the position H1 blocks the outlet 31b of the molten resin passage 31 and the inlet 22a of the gate 22 of the nozzle unit 30, ) Of the molten resin does not flow into the cavity (13).

(II) Falling phase of valve pin (Figure 4)

4, in the state of FIG. 1, as the first piston 70 is lowered to the lower limit position, the valve pin 50 blocks the outlet 31b of the molten resin passage 31 and the inlet 22a of the gate 22 And the lower end moves linearly to the lower limit position H2.

The inlet port 51a and the outlet port 51b of the connection passage 51 correspond to the outlet 31b of the molten resin passage 31 and the inlet 22a of the gate 22, They rotate at a constant angle at the same height and are located at positions that do not communicate with each other.

(III) injection step (Figure 5)

When the compressed air is supplied to the lower fourth chamber 82 of the second piston 80 through the fourth flow path 64 in the state of FIG. 4, the second piston 80 is moved to the upper limit position . As the second piston 80 rises, the cam pin 55 also ascends and the valve pin 50 is rotated about the spiral direction of the helical groove 53b to which the cam pin 55 is engaged The inlet 51a and the outlet 51b of the connecting passage 51 communicate with the outlet 51b of the molten resin passage 31 and the inlet 22a of the gate 22 with each other as shown in Fig. The molten resin on the side of the molten resin passage 31 of the nozzle portion 30 is injected in the inclined direction with respect to the surface of the cavity 13 while passing through the gate 22 and is filled in the cavity 13. [

Since the molten resin is injected in the inclined direction into the cavity 13 by the inclined gate 22 and is filled therein, a phenomenon of causing ripples in the molten resin in the cavity, which is a cause of the flow mark on the surface of the injection molded product And also improves fluidity in the cavity.

(IV) Gate Closure and Gate Cutting Step (Figure 6)

When the injection is completed in the injection step, the second piston 80 is lowered to the lowered position as shown in FIG. 4 in the state of FIG. When the second piston 80 descends, the valve pin 50 is rotated by the cam action of the cam mechanism of the cam pin 55 and the helical groove 53b to move the molten resin passage 31 and the gate (22) to close the inlet of the gate and the outlet of the molten resin passage, and at the same time the resin protruding from the end of the gate is cut.

(V) Opening of cavities and taking out molding products

After the molten resin in the cavity is formed through the step (IV), the valve pin 50 is raised to the upper limit position in the state shown in FIG. 1, and then the movable die 12 is separated from the fixed die 11 The molded product is taken out from the cavity 13.

11; Fixed die 12: movable die
13: cavity 13a: gate surface
21: gate block 22: gate
22a: Gate inlet 30: Nozzle part
31: molten resin passage 31a: inlet
31b: outlet 33: valve pin hole
40: Manifold folder 41: Runner
50: valve pin 51: connection passage
51a: inlet 51b: outlet
53: cam track 53a: straight groove
53b: helical groove 55: cam pin
60: upper plate 61, 62, 63, 64:
70: first piston 71: first chamber
72: second chamber 80: second piston
81: third chamber 82: fourth chamber

Claims

A gate 22 formed to be inclined at a predetermined angle with respect to the surface 13a of the cavity 13 and a molten resin passage 31 for guiding the molten resin of the runner 41 on the side of the manifold 40 to the cavity 13 side And a nozzle portion 30 formed in the fixing die 11 by forming a valve pin hole 33. The inlet 22a of the gate 22 and the outlet 31b of the molten resin passage 31 A gate valve apparatus for opening and closing the inclined gate (22) in a hot runner injection mold opened in an inner wall of the valve pin hole (33)
Wherein the gate valve device comprises:
A connecting passage 51 for slidably moving in the valve pin hole 33 and for connecting the outlet 31b of the molten resin passage 31 and the inlet 22a of the gate 22 to each other, A valve pin (50) provided;
A first piston 70 for raising or lowering the valve pin 50 in the longitudinal direction and a second piston 80 for vertically moving up and down by supporting the valve pin 50 in a slidable manner, Piston mechanism; And
When the second piston 80 reciprocates linearly between the upper limit position and the lower limit position, the linear reciprocating movement of the second piston 80 is controlled such that the connection passage 51 of the valve pin 50 is communicated with the molten resin passage 31 Of the gate 22 and the outlet 31b of the molten resin passage 31 and the inlet 22a of the gate 22 and the outlet 31b of the molten resin passage 31 and the inlet 22a of the gate 22, To the rotary operation of the valve pin (50), which rotates reciprocally between the valve member (50) and the valve member (50).

The method according to claim 1,
The cam mechanism includes at least one cam pin (55) fixed to the side wall of the second piston (80) radially protruding from the second piston (80) toward the outer peripheral surface of the valve pin (50); A straight groove 53a extending in the longitudinal direction on the outer circumferential surface of the valve pin 50 and a helical groove 53b formed continuously at an upper end of the straight groove 53a at a constant helical angle 53), and the tip of the corresponding cam pin (55) is slidably accommodated in the cam track (53).

3. The method of claim 2,
When the first piston 70 is raised to the upper limit position, the lower side wall of the valve pin 50 opens the gate inlet 22a and simultaneously closes the outlet 31b of the molten resin passage 31 When the first piston 70 is lowered to the lower limit position, the lower side wall of the valve pin 50 is connected to the gate inlet 22a and the outlet 31b of the molten resin passage 31 To the lower limit position where it closes the gate valve.

3. The method of claim 2,
When the second piston 80 moves to the lower limit position, the outer circumferential surface of the valve pin 50 is rotated to a position where it cuts off the outlet 31b of the molten resin passage 31 and the gate inlet 22a When the second piston 80 is moved to the upper limit position, the valve pin 50 is rotated by the cam mechanism so that the connecting passage 51 of the valve pin 50 is connected to the outlet of the molten resin passage 31 31b) and the inlet (22a) of the gate (22) are communicated with each other.

The method according to claim 1,
Wherein the gate (22) is formed in a curved surface with a gently convex upper side wall of the passage.