JP6841581B1 - Shut-off nozzle featuring a needle valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shut-off nozzle capable of stably closing a resin flow path by a needle valve even if deteriorated resin is deposited in an injection nozzle. SOLUTION: A shut-off nozzle (1) in which a needle valve (3) is inserted into an oblique hole (7) extending from an outer peripheral surface of the nozzle to a resin flow path (6) in the nozzle is targeted. The needle valve (3) is formed of a columnar shaft portion (11) and a tip portion (12). In the present invention, the shaft portion (11) has an outer diameter (D) of a resin flow path in the nozzle. Make it larger than the inner diameter (d) of (6). The hole (7) is formed at a predetermined depth across the resin flow path (6) in the nozzle, whereby a predetermined recess (9) is formed on the inner peripheral surface of the resin flow path (6) in the nozzle. To do so. When the needle valve (3) is advanced, the resin flow path (6) in the nozzle is closed by the side surface of the shaft portion (11). [Selection diagram] Fig. 1

Description

The present invention relates to a shut-off nozzle, and more particularly to a needle-type shut-off nozzle in which a needle valve is inserted obliquely with respect to the injection nozzle to close the resin flow path. is there.

Since the shut-off nozzle is designed to block or open the resin flow path of the injection nozzle, it is used when handling a resin that is prone to so-called spilling of resin leaking from the injection nozzle. It is also used for other purposes, such as when it is desired to prevent the foamed resin from foaming in the injection nozzle. There are various types of shut-off nozzles, such as rotary valve type and needle type. In the rotary valve type, a columnar rotary valve is provided in the resin flow path of the injection nozzle, and the rotary valve has a through hole penetrating in the radial direction on the side surface thereof, depending on the rotation position of the rotary valve. The through holes allow the resin flow path to communicate or close. The needle type is provided with a needle valve that can move forward and backward with respect to the injection nozzle. The resin flow path in the injection nozzle has a small diameter in the vicinity of the outlet, and when the needle valve is driven, the portion having this small diameter is closed and the resin flow path is blocked. Each type of shut-off nozzle has advantages, but the needle-type shut-off nozzle is suitable for foaming of honey or foamed resin in that it can close the resin flow path near the outlet of the injection nozzle. It can be said that it is excellent because it can be suppressed. There are various types of needle-type shut-off valves, and in the type in which the needle valve is housed in the injection nozzle so that it is coaxial with the axis of the injection nozzle, the mechanism for driving the needle valve becomes slightly complicated. At the same time, the shape of the resin flow path in the injection nozzle becomes complicated. On the other hand, as described in Patent Documents 1 and 2, a needle valve is inserted obliquely with respect to the injection nozzle to close the resin flow path in the injection nozzle.

Japanese Unexamined Patent Publication No. 49-86439 Japanese Unexamined Patent Publication No. 3-274125

As shown in FIG. 4A, the shut-off nozzle 50 described in Patent Document 1 is provided on the heating cylinder 51, and has an end cap 53 fixed to the heating cylinder 51 and an end thereof. It is composed of an injection nozzle 54 provided on the cap 53. An insertion hole 56 is formed in the end cap 53 in an oblique direction from the side surface thereof, and a needle valve 58 is inserted into the insertion hole 56. The needle valve 58 is provided with a piston cylinder unit 59 driven by air or hydraulic pressure at its rear end, and the piston cylinder unit 59 is attached to the heating cylinder 51 by an attachment member 61. The injection nozzle 54 is provided with a seat portion 62 on which the tip of the needle valve 58 is seated in the resin flow path. Therefore, when the piston cylinder unit 59 is driven to advance the needle valve 58, the tip of the needle valve 58 comes into contact with the seat portion 62. The needle valve 58 has a smaller diameter than the resin flow path in the injection nozzle 54, but the opening portion in the seat portion 62 is formed to have a smaller diameter than the tip of the needle valve 58, so that the resin flow path is completely closed. Will be.

The shut-off nozzle 70 described in Patent Document 2 is also composed of an injection nozzle 71 and a needle valve 72, as shown in FIG. 4B. An insertion hole 73 is formed in the injection nozzle 71 in an oblique direction from the side surface thereof, and the insertion hole 73 reaches the resin flow path 75 in the injection nozzle 71. The injection flow path 75 has a slightly reduced diameter in the vicinity of the tip portion of the injection nozzle 71, and a spherical valve seat, that is, a seat portion 77 is formed. The needle valve 72 is inserted into such an insertion port 73 and is moved forward and backward by a predetermined piston cylinder unit 78. When the piston cylinder unit 78 is driven to advance the needle valve 72 in such a shut-off nozzle 70, the spherical head of the needle valve 72 is seated on the seat portion 77 and the resin flow path 75 is closed. Become. Further, when the needle valve 72 is retracted, the needle valve 72 is retracted from the resin flow path 75 and the resin flow path 75 is opened. According to Patent Document 2, it is recommended that the diameter of the needle valve 72 be equal to the inner diameter of the resin flow path 75.

In the conventional shut-off nozzle of the type in which the needle valve is driven obliquely with respect to the injection nozzle as shown in (A) and (B) of FIG. 4, the drive mechanism is shut off. It can be installed outside the nozzle, and the structure is simple and excellent. However, there are some issues that need to be resolved. Specifically, after a long period of operation, there is a problem that the deteriorated resin causes the needle valve to insufficiently close the resin flow path. The shut-off nozzle 50 described in Patent Document 1 also has the head of the needle valve 58 seated on the seat portion 62, and the shut-off nozzle 70 described in Patent Document 2 also has the head of the needle valve 72 on the seat portion 77. By sitting down, the resin flow paths are closed. That is, the resin flow path is closed when the head is seated on the seat portions 62 and 77 in a liquid-tight manner. However, if the operation is continued for a long period of time, deteriorated resin may be deposited on the seat portions 62 and 77. If even a small amount of resin is deposited, the heads of the needle valves 58 and 72 do not sit on the seat portions 62 and 77 in a liquid-tight manner, and a gap is created. This results in insufficient closure of the resin flow path by the needle valves 58 and 72.

An object of the present invention is to provide a shut-off nozzle that solves the above problems. Specifically, the needle valve advances and retreats diagonally with respect to the injection nozzle to open the resin flow path in the injection nozzle. -A shut-off nozzle that is designed to be closed, and even if some resin that has deteriorated due to long-term operation accumulates in the injection nozzle, the needle valve can stably close the resin flow path. It is intended to provide a nozzle.

In the present invention, in order to achieve the above object, a needle valve is inserted into an oblique hole reaching the resin flow path in the nozzle from the outer peripheral surface of the nozzle, and the needle valve is driven to close or open the resin flow path in the nozzle. Targets shut-off nozzles that are designed to be used. The needle valve is formed of a columnar shaft portion and a tip portion. In the present invention, the shaft portion is configured so that the outer diameter is larger than the inner diameter of the resin flow path in the nozzle. Then, the holes are formed to a predetermined depth across the resin flow path in the nozzle so that a predetermined recess is formed on the inner peripheral surface of the resin flow path in the nozzle. When the needle valve is advanced and the tip portion is housed in the recess, the side surface of the shaft portion is configured to close the resin flow path in the nozzle.

That is, in the present invention, the needle valve is inserted into an oblique hole reaching the resin flow path in the nozzle from the outer peripheral surface of the nozzle, and the needle valve is driven to close or open the resin flow path in the nozzle. The needle valve is formed from a columnar shaft portion and a tip portion, and the outer diameter of the shaft portion is larger than the inner diameter of the resin flow path in the nozzle. A predetermined depth is formed across the resin flow path in the nozzle, whereby a predetermined recess is formed on the inner peripheral surface of the resin flow path in the nozzle, and the needle valve is advanced to advance the tip portion. It is configured as a shut-off nozzle characterized in that the side surface of the shaft portion closes the resin flow path in the nozzle when it is housed in the recess.
The invention according to claim 2 is characterized in that, in the shut-off nozzle according to claim 1, the tip portion of the needle valve is formed in a hemispherical shape and the recess is formed in a hemispherical concave surface. It is configured as a shut-off nozzle.
The invention according to claim 3 is configured as a shut-off nozzle according to claim 1 or 2, wherein the hole is enlarged in the vicinity of the outer peripheral surface of the nozzle.

As described above, in the present invention, the needle valve is inserted into the diagonal hole reaching the resin flow path in the nozzle from the outer peripheral surface of the nozzle, and the needle valve is driven to close or open the resin flow path in the nozzle. It is intended for shut-off nozzles that have become. In other words, it targets shut-off nozzles that have a simple structure and can be provided at a relatively low cost. According to the present invention, the needle valve is formed of a columnar shaft portion and a tip portion, and the outer diameter of the shaft portion is larger than the inner diameter of the resin flow path in the nozzle, and the hole crosses the resin flow path in the nozzle. Therefore, a predetermined recess is formed on the inner peripheral surface of the resin flow path in the nozzle. According to the present invention, when the needle valve is advanced and the tip portion is housed in the recess, the side surface of the shaft portion closes the resin flow path in the nozzle. Therefore, even if a foreign substance such as deteriorated resin is slightly accumulated in the dent and the advancing length of the needle valve is slightly shortened, the resin flow path in the nozzle is closed by the shaft portion of the needle valve, so that it is stable. The resin flow path in the nozzle can be closed. That is, even if the deteriorated resin is deposited, the effect that the closure is unlikely to be incomplete can be obtained. According to another invention, the tip of the needle valve is formed in a hemispherical shape, and the recess is formed in a hemispherical concave surface. Then, the tip of the needle valve can be smoothly seated in the recess. According to yet another invention, the hole is enlarged in the vicinity of the outer peripheral surface of the nozzle. Then, the contact area between the hole and the shaft portion of the needle valve becomes small, and the frictional force acting when the needle valve is moved forward and backward can be suppressed. As a result, the needle valve can be driven by an actuator having a relatively small driving force, and a shut-off nozzle can be provided at low cost.

It is a front sectional view which shows the shut-off nozzle which concerns on this embodiment. In the figure explaining the operation of the shut-off nozzle according to the present embodiment, (A) is a state in which the needle valve is retracted, and (B) is a resin flow path in the nozzle of the shut-off nozzle in which the deteriorated resin is discharged. (C) is a front sectional view of the shut-off nozzle showing the state of being deposited on the needle valve and the state of advancing the needle valve. It is a front sectional view which shows the shut-off nozzle which concerns on other embodiment of this invention. (A) and (B) are front sectional views showing a conventional shut-off nozzle.

Hereinafter, embodiments of the present invention will be described. Although not shown in the figure, the injection device is roughly composed of a heating cylinder and a screw, and a nozzle adapter 5 is provided at the tip of the heating cylinder. The shut-off nozzle 1 according to the present embodiment is provided on the nozzle adapter 5 as shown in FIG.

The shut-off nozzle 1 according to the present embodiment is composed of an injection nozzle 2 and a needle valve 3, and the injection nozzle 2 is formed with a flow path through which resin flows. In the present embodiment, this flow path has a relatively large inner diameter on the nozzle adapter 5 side, and is formed to have a relatively small diameter from the center to the tip. The flow path formed with this small diameter is referred to as the resin flow path 6 in the nozzle in the present embodiment, and the resin flow path 6 in the nozzle is opened and closed by the needle valve 3 described later. There is.

The injection nozzle 2 is provided with a hole 7 that reaches the resin flow path 6 in the nozzle from the outside, that is, the outer peripheral surface of the nozzle. The hole 7 is provided near the tip of the injection nozzle 2 and reaches the resin flow path 6 in the nozzle from diagonally rearward with respect to the axis of the injection nozzle 2. The hole 7 has a feature peculiar to the present invention. That is, after the hole 7 reaches the resin flow path 6 in the nozzle, it reaches the inner wall on the opposite side of the resin flow path 6 in the nozzle so as to extend further, and the inner wall is cut by a predetermined depth. As a result, a recess 9 is formed on the inner wall of the resin flow path 6 in the nozzle. The recess 9 is adapted to accommodate the tip 12 of the needle valve 3 described below, and is formed in a shape suitable for the shape of the tip 12. In the present embodiment, the recess 9 is formed on a semicircular spherical concave surface.

The needle valve 3 is composed of a columnar shaft portion 11 having a predetermined length and a tip portion 12 formed at the tip of the shaft portion 11, and is slidably inserted into the hole 7 of the injection nozzle 2. There is. The tip portion 12 is formed in a hemispherical shape so as to smoothly contact the recess 9. Although not shown in the figure, the needle valve 3 is moved forward and backward by a predetermined actuator.

The greatest feature of the present invention is that the outer diameter D of the shaft portion 11 of the needle valve 3 is sufficiently larger than the inner diameter d of the resin flow path 6 in the nozzle. The resin flow path 6 in the nozzle is closed by the side surface of the large-diameter shaft portion 11. Since the hole 7 formed in the injection nozzle 2 naturally has the same diameter as the shaft portion 11, the inner diameter is larger than that of the resin flow path 6 in the nozzle. Therefore, the hole 7 is opened so as to cross the resin flow path 6 in the nozzle, and the bore of the resin flow path 6 in the nozzle is discontinuously divided by a predetermined range crossed by the hole 7. Therefore, when the needle valve 3 advances, the resin flow path 6 in the nozzle is completely blocked by the side surface of the shaft portion 11 of the needle valve 3. In other words, it will be completely closed.

In the shut-off nozzle 1 according to the present embodiment, the recess 9 is formed relatively deeply. Therefore, when the needle valve 3 moves forward most and its tip portion 12 is seated in the recess 9, the shaft portion 11 of the needle valve 3 is also housed in the recess 9 by a predetermined section 14. The shut-off nozzle 1 according to the present embodiment can be stably closed by the needle valve 3 even if a predetermined amount of deteriorated resin is deposited in the resin flow path 6 in the nozzle, but this section 14 is secured. By doing so, such an effect is guaranteed.

The operation of the shut-off nozzle 1 according to the present embodiment will be described. The actuator (not shown in the figure) is driven to retract the needle valve 3. Then, as shown in FIG. 2A, the resin flow path 6 in the nozzle is opened. The resin can be injected by driving a screw not shown in the figure. When the needle valve 3 is advanced, the resin flow path 6 in the nozzle is closed as shown in FIG. Each time the molding cycle is performed, the needle valve 3 is moved forward and backward to open and close the resin flow path 6 in the nozzle. When the molding cycle is repeated, deteriorated resin or the like may be deposited on the resin flow path 6 in the nozzle. FIG. 2B shows that the deteriorated resin 16 is deposited in the recess 9. When the actuator is driven to advance the needle valve 3, the tip portion 12 of the needle valve 3 comes into contact with the deteriorated resin 16 as shown in FIG. 2C. At this time, the tip portion 12 cannot be seated in the recess 9. However, if the amount of the deteriorated resin 16 deposited is small, the resin flow path 6 in the nozzle is closed by the side surface of the shaft portion 11 of the needle valve 3. The resin flow path 6 in the nozzle can be stably closed until the deteriorated resin 16 is deposited and the amount reaches the amount corresponding to the length of the section 14 shown by FIG.

The shut-off nozzle 1 according to the present embodiment can be deformed in various ways. FIG. 3 shows the shut-off nozzle 1'according to the second embodiment. In the second embodiment, there are two features, and the first feature is that the hole 7'is enlarged in the vicinity of the outer peripheral surface of the nozzle as indicated by reference numeral 18. As a result, the area where the inner peripheral surface of the hole 7'and the needle valve 3 slide is reduced, and the needle valve 3 can be driven with a relatively small driving force. The second feature is that the dent 9'is relatively shallow. If the dent 9'is deep, the deteriorated resin is likely to be deposited, but since it is relatively shallow, it is difficult to be deposited. However, as a result, the section 14'is slightly shortened, and the margin for stably closing the resin flow path 6 in the nozzle by the needle valve 3 is slightly reduced.

The shut-off nozzle 1 according to the present embodiment can be changed in various ways. For example, a limit switch for detecting the position of the needle valve 3 may be provided. When the needle valve 3 is advanced, the needle valve 3 does not abut on the recess 9 when the deteriorated resin 16 is deposited in the recess 9 as shown in FIG. 2 (C). If the advance position of the needle valve 3 is detected by the limit switch, it is possible to detect when the resin 16 that has deteriorated beyond the permissible amount is deposited. That is, the timing at which the shut-off nozzle 1 should be cleaned can be detected. The needle valve 3 can also be deformed. The tip portion 12 of the needle valve 3 does not have to be hemispherical, but may be formed into a conical shape, a truncated cone shape, or another shape. The angles of the hole 7 and the needle valve 3 can also be modified. In the embodiment shown in FIG. 1, the hole 7 and the needle valve 3 are arranged at an acute angle that is sufficiently small with respect to the resin flow path 6 in the nozzle, but may be arranged at an angle close to a right angle. ..

1 Shut-off nozzle 2 Injection nozzle 3 Needle valve 6 Resin flow path in nozzle 7 Hole 9 Recess 11 Shaft 12 Tip 14 Section 16 Deteriorated resin D Needle valve outer diameter d Inner diameter of resin flow path 6 in nozzle

Claims (3)

A needle valve is inserted into an oblique hole that reaches the resin flow path in the nozzle from the outer peripheral surface of the nozzle, and the needle valve is driven to close or open the resin flow path in the nozzle. And
The needle valve is formed of a columnar shaft portion and a tip portion, and the outer diameter of the shaft portion is larger than the inner diameter of the resin flow path in the nozzle.
The hole is formed at a predetermined depth across the resin flow path in the nozzle, whereby a predetermined recess is formed on the inner peripheral surface of the resin flow path in the nozzle.
A shut-off nozzle characterized in that when the needle valve is advanced and the tip portion is housed in the recess, the side surface of the shaft portion closes the resin flow path in the nozzle. The shut-off nozzle according to claim 1, wherein the tip portion of the needle valve is formed in a hemispherical shape and the recess is formed in a hemispherical concave surface. The shut-off nozzle according to claim 1 or 2, wherein the hole is enlarged in the vicinity of the outer peripheral surface of the nozzle.

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