JP2020078886A - Mold device and method for manufacturing flow passage member - Google Patents

Abstract

To enhance durability in a mold device for a bent flow passage, in which an undercut mold is displaced in parallel so as to be demolded.SOLUTION: A flow passage molding mold 20 of a mold device 1 comprises: a first core pin 30 to be advanced/retracted between a molding position on a tip end side and a retraction position on a base end side along the axial direction L; a second core pin 40 having an inner turn molding part 41 for molding a circumferential surface portion 92b on an inner turn side of a flow passage 90, and a linkage mechanism 5 for displacing the second core pin 40 toward the side opposite to the inner turn side when the first core pin 30 retracts to the retraction position. The linkage mechanism 5 includes: a tilt guide 51 provided on either one of core pins 30 and 40 so as to extend in the tilt direction; and a sliding engagement part 52 provided on the other core pin. The tilt guide 51 and the sliding engagement part 52 are engaged to each other slidably toward the tilt direction. The tilt angle of the tilt direction with respect to the axial direction L is 0.5°-15°.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a device for manufacturing a flow path member such as a pipe or a pipe joint, and more particularly to a mold device for manufacturing a flow path member having a curved flow path by injection molding.

  In the curved flow path portion of the flow path member such as the pipe and the pipe joint, the pressure loss can be reduced by attaching R to the inner peripheral surface. On the other hand, when this kind of flow path member is manufactured by an injection molding die, the inner peripheral portion of the inner peripheral surface of the curved flow path portion is undercut. In order to remove such an undercut, various mold devices have been developed (see Patent Documents below).

  For example, in Patent Documents 1 to 5, it is possible to perform die cutting by rotating an undercut die during die cutting.

  Patent Document 6 describes a mold device that injection-molds an elbow. The mold apparatus includes an undercut mold piece for an inner peripheral portion of the inner peripheral surface of the curved flow path of the elbow. The back surface of the undercut mold piece opposite to the molding surface is inclined with respect to the die cutting direction along the axis of the straight portion of the elbow. A ridge extending in the tilt direction is formed on the back surface. The ridge is slidably fitted in an inclined groove formed in an inclined tip end surface of a slide driving plate for clamping and demolding. When the slide drive plate is slid in the die-cutting direction, the ridges are slid along the inclined grooves, whereby the undercut die piece is bent and can be die-shifted to the outer peripheral side of the flow path. At this time, the bottom surface of the undercut mold piece, which is orthogonal to the die-cutting direction, is rubbed against the tip surface of another mold piece for the linear flow path of the elbow.

Japanese Patent Laid-Open No. 2016-21539 JP, 2002-018904, A Japanese Patent No. 5969617 JP-A-52-085253 JP-A-52-150467 Japanese Utility Model Publication No. 57-36410

In a mold device (for example, Patent Documents 1 to 5) in which an undercut mold can be rotated to remove the mold, a large load is applied to a rotating mechanism such as a hinge, and there is a problem in long-term durability.
In the mold device of Patent Document 6, the undercut mold piece is bent and moved in parallel to the outer peripheral side of the flow path so that the mold can be removed. However, since the ridges and the inclined grooves are short, In order to secure the required parallel movement amount (deviation amount), it is necessary to increase the angle of inclination of the ridges and inclined grooves, which places a large load on the undercut mold piece and poses a problem with long-term durability. .
In view of such circumstances, it is an object of the present invention to improve the durability of a mold device for a curved flow path, which is obtained by shifting an undercut mold in parallel and punching.

In order to solve the above problems, the present invention is a mold device for injection molding a flow path member having a flow path including a curved flow path part,
An outer peripheral molding die for molding the outer peripheral surface of the flow path member,
A flow path molding die for molding the flow path in the flow path member,
, The flow path molding die,
A first core pin that extends in the axial direction and is moved back and forth between the molding position on the distal end side and the retracted position on the proximal end side along the axial direction;
A second core pin extending along the first core pin, the second core pin having an inner peripheral molding portion that molds a peripheral surface portion on the inner peripheral side of the inner peripheral surface of the flow path;
An interlocking mechanism that, when the first core pin retracts from the molding position to the retracted position, shifts the second core pin to a side opposite to the inner circumference side and then retracts;
And the interlocking mechanism is provided on one of the first and second core pins so as to extend in an inclination direction that is inclined toward the tip end side with respect to the axial direction and opposite to the inner circumference side. An inclined guide and a slide engagement portion provided on the other of the first and second core pins, the inclination guide and the slide engagement portion are slidably engaged in the inclination direction,
An inclination angle of the inclination direction with respect to the axial direction is 0.5° to 15°.

In the mold device, the second core pin serves as an undercut mold. In the flow path member, the peripheral surface portion on the inner circumference side of the curved flow path portion is undercut.
By setting the inclination angle to 0.5° to 15°, it is possible to secure the parallel movement amount (deviation amount) to the side opposite to the inner circumference side of the second core pin and reliably perform die cutting, and the first and second The load applied to the two-core pin is reduced, and the durability of the mold device can be improved.
When the inclination angle is less than 0.5°, the parallel movement amount (shift amount) of the second core pin to the side opposite to the inner circumference side is too small, and the undercut process becomes difficult.
If the inclination angle exceeds 15°, the load applied to the first and second core pins becomes excessive.
The inclination angle is preferably 2° to 5°.
The curved flow path portion refers to a portion in which the flow direction of the fluid in the flow path changes, and includes a flow path curved in an arc shape, a flow path bent at an angle, a confluence portion of a straight path and a branch path, and the like. .

The radius of curvature of the inner circumference of the curved flow passage molding portion for molding the curved flow passage portion in the inner circumference molding portion is 0.15 of the outer peripheral diameter of the cross section orthogonal to the axis of the curved flow passage molding portion. It is preferably double to 1.7 times.
As a result, it is possible to surely perform the die cutting and reduce the pressure loss in the curved flow path portion.
When the radius of curvature is less than 0.15 times the outer diameter, the effect of reducing pressure loss is small.
When the radius of curvature exceeds 1.7 times the outer diameter, the required amount of sliding of the second core pin becomes half or more of the inner diameter, and undercut processing is not easy.
The radius of curvature is preferably 0.3 to 1 times the outer diameter.

A ring portion is formed at one location in the axial direction of the first core pin, the outer peripheral surface of the ring portion constitutes a molding surface of the entire inner circumference of a predetermined portion of the flow path, and the second core pin is It is preferably inserted through the ring portion.
As a result, the entire circumference of the predetermined portion of the flow path can be molded with only the first core pin. Therefore, no streak-like or step-like parting line (joint mark of a plurality of core pins) is formed on the inner circumference of the predetermined portion.
Preferably, the predetermined portion is an end portion of the flow path member. When another pipe is connected to the end of the flow path member and the space between the flow path member and the other pipe is sealed with packing or the like, the sealing performance is improved because there is no parting line. When a fluid such as water is passed through the flow path member and the another pipe, it is possible to reliably prevent the fluid from leaking.
From the viewpoint of eliminating the parting line, the injection molding die apparatus according to the present invention includes an outer peripheral molding die for molding the outer peripheral surface of the flow path member and a flow path molding for molding the flow path in the flow path member. A mold, wherein the flow path molding mold includes first and second core pins extending in the axial direction, a ring portion is formed at one position in the axial direction of the first core pin, and an outer circumference of the ring portion is provided. The surface constitutes a molding surface of the entire inner circumference at a predetermined portion of the flow path, and the second core pin is inserted into the ring portion.

The first core pin has an outer peripheral molding portion that molds a peripheral surface portion on the outer peripheral side of the inner peripheral surface of the flow path,
A part of the ring portion in the circumferential direction is integral with the outer periphery molding portion,
A partial annular portion excluding the part of the ring portion is projected from the outer periphery molding portion to the inner periphery side,
It is preferable that the second core pin is inserted between the inner peripheral surface of the partial annular portion and the outer peripheral molding portion.
As a result, the outer peripheral surface portion is formed by the first core pin, the inner peripheral surface portion is formed mainly by the second core pin, and the entire inner periphery of the predetermined portion is formed by the first core pin. It can be molded by the ring part.

A stopper portion protruding from the peripheral surface of the inner circumference molding portion is formed on the base end side of the ring portion of the second core pin,
It is preferable that the ring portion abuts on the stopper portion while the first core pin is retracting.
Until the ring portion abuts the step portion, the second core pin is displaced outward by the interaction of the slant guide and the slide engagement portion. After the ring portion has abutted against the stopper portion, the second core pin and the first core pin are united and die-cut.

The method of the present invention is a method for producing a flow path member having a flow path including a curved flow path portion by the mold device,
A step of supplying a resin to a cavity defined between an outer peripheral molding die and a flow channel molding die of the mold device to mold a flow channel member having a flow channel including a curved flow channel portion;
A retracting step of retracting the first core pin of the flow path molding die from the molding position at the time of molding to a retracted position on the base end side in the axial direction;
A second core pin having an inner peripheral molding portion that molds a peripheral surface portion on the inner peripheral side of the inner peripheral surface of the flow channel in the flow channel molding die is interlocked with the first core pin when retracted by an interlocking mechanism. Then, an interlocking step of moving back to the side opposite to the inner circumference side and then retreating,
And the shift amount of the second core pin with respect to the retracted amount of the first core pin is tan 0.5° times to tan 15° times.
When it is less than tan 0.5° times (about 0.008 times), the amount of parallel movement (shift amount) of the second core pin to the side opposite to the inner circumference side is too small, and the undercut process becomes difficult.
If it exceeds tan15° times (about 0.268 times), the load applied to the first and second core pins becomes excessive.
The shift amount of the second core pin with respect to the retracted amount of the first core pin is preferably tan2° to tan5° (about 0.034 to about 0.088).

  According to the present invention, it is possible to improve the durability of a mold device for a curved flow path.

FIG. 1 is a front sectional view of a mold apparatus according to the first embodiment of the present invention. FIG. 2 is a front view of a tip end portion of a flow path forming mold of the mold device. FIG. 3A is a plan view of the second core pin of the flow path molding die. FIG. 3B is a plan view of the first core pin of the flow path molding die. FIG. 4A is an exploded perspective view of the flow path molding die. FIG. 4B is a perspective view of the flow path molding die in an assembled state. FIG. 5 is a sectional view taken along the line VV of FIG. 6A to 6D are explanatory views sequentially showing the die cutting process. FIG. 7 is a cross-sectional view of a flow path member made by the mold device. FIG. 8 is a front sectional view of a mold device according to the second embodiment of the present invention. FIG. 9 is a cross-sectional view showing a die-cutting process of the flow path forming die of the die apparatus according to the second embodiment. FIG. 10A is a front view showing the flow path molding die of the mold device according to the third embodiment of the present invention with the core pin unit in the molding position. 10B to 10C are front views sequentially showing a die cutting process of the core pin unit.

Embodiments of the present invention will be described below with reference to the drawings.
1 to 7 show a first embodiment of the present invention.
As shown in FIG. 1, the flow path member 9 is injection-molded by the mold device 1. As shown in FIG. 7, the flow path member 9 to be molded is, for example, an elbow (L-shaped pipe joint). The flow channel 90 of the flow channel member 9 includes a pair of straight flow channel portions 91 and a curved flow channel portion 92. The curved flow path portion 92 is curved at 90°. The bending angle (center angle) of the curved flow path portion 92 is not limited to 90° and may be less than 90° or greater than 90°. The inner peripheral portion 92b of the inner peripheral surface of the curved flow path portion 92 serves as an undercut during injection molding.

Straight flow path portions 91 are connected to both ends of the curved flow path portion 92, respectively. The axes of the pair of linear flow path portions 91 are orthogonal to each other. The inner diameter of the straight flow path portion 91 is larger than the inner diameter of the curved flow path portion 92. An annular step 93 is formed between the inner peripheral surface of the straight flow path portion 91 and the inner peripheral surface of the curved flow path portion 92.
The inner diameter of the straight flow passage portion 91 may be the same as the inner diameter of the curved flow passage portion 92, or the straight flow passage portion 91 and the curved flow passage portion 92 may be connected without a step.
The end portion 91e of each linear flow passage portion 91 is expanded in diameter for connection with another pipe 8 or the like.

  The material of the flow path member 9 is, for example, a high-strength engineering plastic such as polyphenylsulfone (PPSU) or polyphenylene sulfide (PPS), but is not limited to this. Polyethylene (PE), polypropylene (PP), polyacetal (POM) ) Or the like, which may be a relatively soft and slidable resin.

As shown in FIG. 1, the mold device 1 includes an outer peripheral molding mold 10 and a flow path molding mold 20. The outer peripheral molding die 10 molds the outer peripheral surface of the flow path member 9.
The flow path forming die 20 forms the inner peripheral surface of the flow path member 9, and thus forms the flow path 90. The flow path molding die 20 includes a pair of core pin units 21 and 22. The axis lines L ₂₁ and L ₂₂ of the pair of core pin units ₂₁ and ₂₂ are orthogonal to each other. One core pin unit 21 molds one straight flow passage portion 91 of the flow passage 90 and a 45 degree portion of the curved flow passage portion 92 on the side of the one straight flow passage portion 91. The other core pin unit 22 forms the other straight flow path portion 91 of the flow path 90 and the 45 degree portion of the curved flow path portion 92 on the side of the other straight flow path portion 91.
The two core pin units 21, 22 have substantially the same structure, and their movements during injection molding are also substantially the same. Hereinafter, unless otherwise specified, one core pin unit 21 will be described and the other core pin unit 22 will be omitted.

As shown in FIG. 1, the core pin unit 21 of the flow path molding die 20 has a first core pin 30 and a second core pin 40. Each core pin 30, 40 extends in a direction along the axis L ₂₁ of the core pin unit 21 (axial direction L, up and down in FIG. 1 ). These core pins 30 and 40 face each other in the direction along the axis L ₂₂ of the other core pin unit 22. In other words, as shown in FIG. 4, the core pin unit 21 is vertically divided into two (plural) core pins 30 and 40.

  As shown in FIG. 2, the first core pin 30 includes an outer peripheral molding portion 31 at the tip (upper end in FIG. 1) and a first core pin shaft portion 32. The outer peripheral molding portion 31 has a curved shape and molds the peripheral surface portion 92a (FIG. 7) on the outer peripheral side of the inner peripheral surface of the curved flow path portion 92.

  As shown in FIG. 1, the core pin shaft portion 32 is connected to the base end side (lower side in FIG. 1) of the outer periphery molding portion 31. The core pin shaft portion 32 includes a straight flow path molding portion 33 that is continuous with the outer circumference molding portion 31 and a flow path outer portion 34. As shown in FIG. 3( b) and FIG. 4( a ), the linear flow path forming portion 33 is formed in a partial cylindrical shape, and is a portion of the inner peripheral surface of the linear flow passage portion 91 that is continuous with the outer peripheral surface portion 92 a. Mold 91a. As shown in FIG. 2, a step surface 33d is formed between the outer peripheral molding portion 31 and the linear flow path molding portion 33 to mold the outer peripheral portion of the annular step 93 (FIG. 7).

  As shown in FIG. 1, the flow path outer portion 34 extends from the linear flow path forming portion 33 along the axial direction L toward the base end side (downward in FIG. 1 ). The flow path outer portion 34 is formed in a partial conical shape whose diameter increases toward the base end side. The flow path outside portion 34 does not have a flow path forming portion.

  As shown in FIG. 2 and FIG. 3B, a ring portion 35 is formed in a portion (one axial position) between the linear flow path forming portion 33 of the first core pin 30 and the flow path outer portion 34. Has been done. The ring portion 35 has an annular shape with a diameter slightly larger than that of the linear flow path forming portion 33. An outer peripheral portion 35 a (a part) of the ring portion 35 in the circumferential direction is integrated with the outer peripheral molding portion 31.

An inner peripheral portion of the ring portion 35 in the circumferential direction constitutes a partial annular portion 35b having a semicircular shape (partial annular shape). The partial annular portion 35b projects from the rear surface of the outer peripheral molding portion 31 to the inner peripheral side (left side in FIG. 3B). Both circumferential ends of the outer peripheral surface of the partial annular portion 35b are continuous with the outer peripheral surface of the outer peripheral molding portion 31.
As shown in FIG. 1, the ring portion 35 forms one end portion 91 e (predetermined portion) of the flow channel 90. The outer peripheral surface of the ring portion 35 constitutes a molding surface for molding the entire inner circumference of the flow path end portion 91e.

  As shown in FIGS. 1 and 3B, a back surface 30b (a surface facing the second core pin 30) opposite to the molding surface of the first core pin 30 is an inclined surface over the entire length of the first core pin 30. ing. The back surface 30b is inclined toward the outer peripheral side (the side opposite to the inner peripheral side, the right side in FIG. 1) with respect to the axial direction L toward the tip side (upper side in FIG. 1) of the first core pin 30.

  As shown in FIG. 1, the advancing/retreating mechanism 2 is connected to the first core pin 30. The advancing/retreating mechanism 2 is composed of a cylinder and other actuators. By the advancing/retreating mechanism 2, the first core pin 30 is moved along the axial direction L along the axial direction L to the molding position (FIG. 1) on the tip side (FIG. 1) and the retracted position (FIG. 6 (FIG. 6 (bottom side)) on the base end side (FIG. 6). It is moved back and forth between (c) and (d) in FIG.

  As shown in FIG. 2 and FIG. 4A, the second core pin 40 includes an inner peripheral molding portion 41 at the tip (upper end in FIG. 2) and a second core pin shaft portion 42. The inner circumference molding portion 41 is curved so as to warp, and molds a circumferential surface portion 92b (undercut) on the inner circumference side of the inner circumferential surface of the curved flow path portion 92. The second core pin 40 having the inner peripheral molding portion 41 constitutes an undercut mold.

As shown in FIG. 2, the inner radius of curvature R ₄₁ of the peripheral surface of the inner circumference molding portion 41 is preferably 0.15 of the outer diameter φ ₄₃ of the cross section orthogonal to the axis along the bend of the inner circumference molding portion 41. Times to 1.7 times, and more preferably 0.3 times to 1 times.
The front end surface 41e of the inner circumference molding portion 41 is a slanted surface inclined by 45 degrees with respect to the axial direction L.

  As shown in FIG. 1, the core pin shaft portion 42 is connected to the base end side (lower side in FIG. 1) of the inner circumference molding portion 41. The core pin shaft portion 42 includes a linear flow path forming portion 43 that is continuous with the inner circumference forming portion 41, and a flow path outer portion 44. As shown in FIGS. 2 and 3(a), the linear flow path forming portion 43 is formed in a partial cylindrical shape, and has a portion 91b that is continuous with the inner peripheral surface portion 92b on the inner peripheral surface of the linear flow passage portion 91. Mold. Between the inner circumference molding portion 41 and the straight flow path molding portion 43, a step surface 43d for molding the inner circumference portion of the annular step 93 (FIG. 7) is formed.

As shown in FIG. 1, the flow path outer portion 44 extends from the straight flow path forming portion 43 along the axial direction L toward the base end side (downward in FIG. 1). The flow path outer portion 44 is formed in a partial cylindrical shape having a diameter larger than that of the straight flow path forming portion 43 and longer than that of the straight flow path forming portion 43. The flow path outer portion 44 is slidably inserted along the axial direction L between the inner peripheral surface of the partial annular portion 35b of the first core pin 30 and the back surface of the outer peripheral molding portion 31.
The flow path outside portion 34 does not have a flow path forming portion.

  As shown in FIG. 4B, a base portion 45 is provided at the base end side (the side opposite to the tip end portion) of the flow path outer portion 44. The base portion 45 projects inward from the partial annular portion 35b. The base portion 45 is arranged on the base end side (lower side in FIG. 4B) of the ring portion 35.

As shown in FIGS. 1 and 4A, a back surface 40b (a surface facing the first core pin 40) opposite to the molding surface of the second core pin 40 is an inclined surface extending over the entire length of the second core pin 40. ing. The back surface 40b is inclined toward the outer peripheral side (opposite the inner peripheral side, the right side in FIG. 1) with respect to the axial direction L toward the tip side (upper side in FIG. 1) of the second core pin 40.
The back surfaces 30b and 40b (opposing surfaces) of the pair of core pins 30 and 40 are in parallel contact with each other and are in contact with each other.

  As shown in FIG. 1, the interlocking mechanism 5 is interposed between the first core pin 30 and the second core pin 40. When the first core pin 30 is retracted from the molding position to the retracted position, the interlocking mechanism 5 interlocks with the movement of the first core pin 30 and the inclined cam mechanism 5a that shifts the second core pin 40 to the outer side (the side opposite to the inner side). And a stopper mechanism 5b for moving the displaced second core pin 40 integrally with the first core pin 30.

  Specifically, the inclined cam mechanism 5a includes a guide protrusion 51 (inclined guide) protruding from the back surface 30b of the first core pin 30 and a guide groove 52 (slide engagement portion) formed in the back surface 40b of the second core pin 40. )including. The partial annular portion 35b and the base portion 45 (stopper portion) are provided as the stopper mechanism 5b.

  As shown in FIG. 5, the cross section of the guide ridge 51 of the inclined cam mechanism 5a has, for example, a substantially T shape. As shown in FIGS. 1 and 3B, the guide ridge 51 extends linearly from the tip end portion to the base end portion of the first core pin 30 along the inclination direction of the back surface 30b. Preferably, it extends over substantially the entire length of the first core pin 30. Therefore, the guide ridge 51 has a length that extends over the outer peripheral molding portion 31 and the core pin shaft portion 32.

As shown in FIG. 3A, the cross section of the guide groove 52 corresponds to the cross section of the guide ridge 51, and has, for example, a substantially T shape. As shown in FIG. 1, the guide groove 52 extends in a straight line from the front end to the base end of the second core pin 40 in parallel with the guide protrusion 51 along the inclination direction of the back surface 40b. Preferably, it extends substantially the entire length of the second core pin 40. Therefore, the guide groove 52 has a length extending over the inner peripheral molding portion 41 and the core pin shaft portion 42.
As shown in FIG. 5, the guide ridge 51 and the guide groove 52 are fitted (engaged) with each other so as to be relatively slidable in the tilt direction.

  The inclination angles of the back surfaces 30b and 40b, and thus the guide ridges 51 and the guide grooves 52, with respect to the axial direction L are 0.5° to 15°, more preferably 2° to 5°.

The flow path member 9 is produced by the mold apparatus 1 as follows.
As shown in FIG. 1, the advancing/retreating mechanism 2 advances the core pin unit 21 to the molding position. At the molding position, the outer peripheral molding portion 31 and the inner peripheral molding portion 41 are arranged inside the outer peripheral molding die 10. A cavity 1c is formed between the outer periphery molding die 10 and the outer periphery molding portion 31 and the inner periphery molding portion 41.
The material of the flow path member 9 is supplied to the cavity 1c. Thereby, the flow path member 9 is injection molded.
The end portion 91e of the flow path 90 can be formed only by the annular ring portion 35 of the first core pin 30 over the entire circumference. Therefore, no streak-like or step-like parting line (joint trace of a plurality of core pins) is formed on the inner peripheral surface of the flow path end portion 91e.

After the injection molding, the advancing/retreating mechanism 2 retracts the first core pin 30 from the molding position to the retracted position.
As shown in FIG. 6A, in the initial stage of the retracting step, the inner peripheral molding portion 41 is hooked on the inner peripheral portion 92b (undercut) of the curved flow path portion 92, so that the second core pin 40 is It stays in the same position as it was during injection molding. Moreover, the guide ridge 51 of the interlocking mechanism 5 slides along the guide groove 52. Due to the inclined cam action of the guide protrusion 51 and the guide groove 52, the second core pin 40 is displaced outward. By the setting of the inclination angle, the displacement amount of the second core pin 40 with respect to the retracted amount of the first core pin 30 becomes tan 0.5° times to tan 15° times (about 0.008 times to about 0.268 times), preferably It becomes tan2° times to tan5° times (about 0.034 times to about 0.088 times).
Due to the displacement of the second core pin 40, the inner peripheral portion 92b (undercut) of the curved flow path portion 92 and the inner peripheral molding portion 41 are released from being caught. Preferably, when the outer peripheral molding die 10 is opened at the same time as the first core pin 30 is retracted, the flow path member 9 is brought into a movable state, and the catch is easily released.

As shown in FIG. 6B, the partial annular portion 35b abuts the base portion 45 (stopper portion) almost at the same time as the catch is released during the retracting process of the first core pin 30. As a result, the second core pin 40 is moved integrally with the first core pin 30 toward the retracted position, and the inner peripheral molding portion 41 moves to the base end side in the axial direction L with respect to the inner peripheral portion 92b of the curved flow path portion 92. To be done.
As shown in FIG. 6C, the core pin unit 21 can be die-cut from the flow path member 9 in this way. Then, the flow path member 9 can be taken out from the mold device 1.
Although illustration is omitted, it is preferable that the second core pin 40 be biased toward the base end side (downward in FIG. 1) with respect to the first core pin 30 by a biasing means such as a spring. As a result, as shown in FIG. 6D, the second core pin 40 after die cutting is moved to the base end side and aligned with the first core pin 40.

In the mold device 1, by making the guide ridge 51 and the guide groove 52 longer than the molding portions 31 and 41, the movable distance of the guide ridge 51 with respect to the guide groove 52 can be increased. Therefore, even if the guide groove 52 has a small inclination with respect to the axial direction L and thus the die-cutting direction, a sufficient amount of parallel movement (deviation amount) of the second core pin 40 to the outer peripheral side can be secured, and die-cutting can be reliably performed.
The inclination angle of the guide ridge 51 and the guide groove 52 with respect to the axial direction L is preferably 0.5° to 15°, more preferably about 2° to 5°, and the second core pin 40 with respect to the retracted amount of the first core pin 30. By setting the deviation amount to preferably about 0.008 times to about 0.268 times, more preferably about 0.034 times to about 0.088 times, it is possible to surely perform the die cutting and the load applied to the core pins 30 and 40. Will be reduced. As a result, the durability of the mold device 1 can be improved.

Further, preferably 1.7 times or less of the outer diameter phi ₄₁ the radius of curvature R ₄₁ of the inner circumference of the inner circumference forming part 41, more preferably by 1 times or less, can be more reliably stamped.
In the molded flow path member 9, the inner radius of curvature of the curved flow path portion 92 is preferably 0.15 times or more, more preferably 0.3 times or more the inner diameter of the cross section of the curved flow path portion 92. can do. As a result, the pressure loss in the curved flow path portion 92 can be reduced.
No parting line is formed on the inner peripheral surface of the flow path end 91e. Therefore, when another pipe is connected to the flow path end portion 91e and the connection portion is sealed with packing or the like, the sealing performance can be improved because there is no parting line. As a result, it is possible to reliably prevent the fluid such as water flowing in the flow path member 9 and the other pipe from leaking from the connecting portion.

Next, another embodiment of the present invention will be described. In the following embodiments, the same reference numerals will be given to the drawings for the configurations that are the same as the configurations described above and the description thereof will be omitted.
<Second Embodiment>
8 and 9 show a second embodiment of the present invention.
As shown in FIG. 9, the flow path member 9B to be molded in the second embodiment is cheese (T-shaped pipe joint). A connecting portion 97 of the main pipe line 95 and the branch pipe line 96 of the flow passage member 9B constitutes a curved flow passage portion that changes the flow direction of the fluid. Inner peripheral surface portions 97b, which are undercuts, are formed on both sides of the connecting portion 97, respectively.

  As shown in FIG. 8, the flow path molding die 20B in the mold apparatus 1B for the flow path member 9B has three core pin units 21B, 22B, 22B. The main duct 95 of the flow path member 9B is formed by the pair of core pin units 22B, 22B. The branch duct 96 of the flow path member 9B is molded by the core pin unit 21B.

The basic structure of the core pin unit 22B for the main conduit 95 is the same as the core pin units 21 and 22 of the first embodiment.
The core pin unit 21B for the branch pipeline 96 is vertically divided into three core pins 30B, 40B, 40B. Specifically, the core pin unit 21B includes a first core pin 30B in the center and second core pins 40B, 40B on both sides. The first core pin 30B extends linearly in the axial direction L and narrows toward the tip (upper end in FIG. 8). Both side surfaces 36, 36 of the first core pin 30B (surfaces facing the second core pin 40B) approach each other toward the tip (upper end in FIG. 8) in the axial direction L, and are opposite to the corresponding inner circumference side. It is a slope that slopes to the side. Guide ridges 51 are formed over the entire length of each side surface 36 in the longitudinal direction.
Although not shown in detail, the peripheral surface portions of the first core pin 30B on both sides orthogonal to the paper surface of FIG. 8 may form the molding surface of the inner peripheral portion of the branch conduit 96.

  A pair of second core pins 40B is provided on both sides of the first core pin 30B. The basic structure of the second core pin 40B is the same as that of the second core pin 40 of the first embodiment, and includes a core pin shaft portion 42B extending along the first core pin 30B and an inner circumference provided at the tip of the core pin shaft portion 42B. The molding part 41B is included. The inner circumference molding portion 41B is curved so as to warp and molds the inner circumference peripheral surface portion 97b (undercut). The core pin shaft portion 42B forms the inner peripheral surface of the branch pipe passage 96.

  The back surface 46 (the surface facing the first core pin 30B) of each second core pin 40B is an inclined surface parallel to the corresponding side surface 36 of the first core pin 30B, and the guide groove is provided over the entire length of the back surface 46 in the longitudinal direction. 52 is formed. The guide ridge 51 is slidably fitted in the guide groove 52.

As shown in FIG. 9, after injection molding, the first core pin 30B is retracted to the base end side in the axial direction L (downward in FIG. 9). At this time, the second core pins 40B on both sides are slid so as to approach each other by the inclined cam mechanism 5a of the guide convex strip 51 and the guide concave groove 52, and come off from the inner peripheral surface portion 97b (undercut). This allows the core pin unit 21B to be die-cut.
Although illustration is omitted, also in the second embodiment, the first core pin 30B is provided with the ring portion 35 for forming the flow path end portion, the second core pin 40B is provided with the stopper portion 45, and the first core pin 30B is retracted. The ring portion 35 may abut the stopper portion 45 on the way, and thereafter, the first and second core pins 30B and 40B may be integrally retracted.

The inclined cam mechanism 5a of the interlocking mechanism 5 is not limited to the guide ridge 51 and the guide groove 52. Further, the inclined cam mechanism 5a may not be provided on the facing surfaces 30b and 40b.
<Third Embodiment>
FIG. 10 shows a third embodiment of the present invention. As shown in FIG. 10A, in the third embodiment, the tilt cam mechanism 5a of the core pin unit 21 includes the guide shaft 53 and the guide hole 54.

  The guide shaft 53 (inclined guide) is formed in a straight column shape or a rod shape, and is arranged on the inner side (left side in FIG. 10) of the facing surface 30b of the first core pin 30. The base end portion (lower end portion in FIG. 10) of the guide shaft 53 is fixed to the base end portion of the first core pin 30. The tip portion (upper end portion in FIG. 10) of the guide shaft 53 is an open end. The guide shaft 53 is inclined toward the outer peripheral side (right side in FIG. 10) toward the tip end side (upper side in FIG. 10) with respect to the axial direction L. The inclination angle of the guide shaft 53 with respect to the axial direction L is 0.5° to 15°, and more preferably 2° to 5°.

A guide hole 54 (slide engagement portion) is formed in the second core pin 40. The guide hole 54 extends along the inclination direction of the guide shaft 53 and penetrates from the base end surface (lower surface in FIG. 10) of the base portion 45 to the tip end surface (upper surface in FIG. 10).
The guide shaft 53 is inserted (engaged) in the guide hole 5 so as to be slidable in the inclination direction.

  As shown in FIGS. 10A to 10C, after injection molding of the flow path member 9 (see FIG. 7 ), the first core pin 30 retracts to the base end side in the axial direction L (downward in FIG. 10 ). To be done. In conjunction with this, the second cam pin 40 is displaced outward (to the right in FIG. 10) by the inclined cam mechanism 5a between the guide shaft 53 and the guide hole 54. The shift amount of the second core pin 40 with respect to the retracted amount of the first core pin 30 is tan 0.5° times to tan 15° times (about 0.008 times to about 0.268 times), and preferably tan 2° times to tan 5° times. (About 0.034 times to about 0.088 times). As a result, the core pin unit 21 can be reliably removed from the mold, and the load applied to the core pins 30 and 40 can be reduced to improve the durability of the mold apparatus 1.

  As shown in FIG. 10C, at the same time as the second core pin 40 clears the undercut during the retracting process of the first core pin 30, the partial annular portion 35b hits the base portion 45 (stopper portion), Then, the second core pin 40 is moved together with the first core pin 30 toward the retracted position. This point is the same as the first embodiment.

The present invention is not limited to the embodiment described above, and various modifications can be made without departing from the spirit of the present invention.
For example, the tilt guides 51 and 53 may be provided on the second core pin, and the slide engagement portions 52 and 54 may be provided on the first core pin. The inclined guide is a guide groove or a guide hole. The slide engagement portion may be a guide ridge or a guide shaft.
The lengths of the tilt guide and the slide engagement portion may be long enough to secure the required parallel movement amount of the core pin, and both are not necessarily long. If the length of one of the tilt guide and the slide engaging portion is equal to or more than the required parallel movement amount, the length of the other may be shorter than the above one or may be partially provided.
The cross-sectional shapes of the guide ridges 51 and the guide grooves 52 are not limited to the T-shape, but can be arbitrarily modified, and may be, for example, a quadrangle or a semicircle. The cross-sectional shapes of the guide ridge 51 and the guide groove 52 are separable in the facing direction of the core pins 30 and 40 (left and right direction in FIG. 1), and the width direction of the core pins 30 and 40 (perpendicular to the paper surface of FIG. 1). The shape may be such that movement is restricted in each direction. The tilt guide and the slide engagement portion may be separable in a direction intersecting the tilt direction of the tilt guide.
In the die cutting process, the second core pin may not be completely removed from the inner peripheral side peripheral surface portion, and may be forcibly removed by slightly touching the inner peripheral side peripheral surface portion. Good. This is because, after the injection molding, if the flow path member is hardened, the second core pin is elastically deformed when it retracts and comes off.
The number of second core pins of the core pin unit is not limited to one or two, and may be three or more. The first core pin may be surrounded by a plurality of second core pins. In this case, the first core pin does not have to have the flow path forming portion.
The flow path member to be molded is not limited to an elbow (L-shaped pipe joint) and cheese (T-shaped pipe joint), and may be a cross-shaped joint or the like.

  The present invention can be applied to fluid pipes such as a water supply pipe, a hot water supply pipe, a drainage pipe, and an air conditioning pipe.

1, 1B Mold device 1c Cavity 2 Forward/backward mechanism 10 Peripheral molding mold 20, 20B Flow path molding mold 30, 30B First core pin 30b Rear surface (opposing surface)
31 Outer peripheral molding portion 32 First core pin shaft portion 35 Ring portion 35b Partial annular portion 36 Both side surfaces (opposing surfaces)
40, 40B Second core pin 40b Rear surface (opposing surface)
41,41B Inner circumference molding part (undercut mold)
42, 42B Second core pin shaft portion (core pin shaft portion)
45 Base (Stopper)
46 back side (opposite side)
5 Interlocking mechanism 5a Tilt cam mechanism 5b Stopper mechanism 51 Guide ridge (tilt guide)
52 Guide groove (slide engagement part)
53 Guide shaft (tilt guide)
54 Guide hole (slide engagement part)
9, 9B Flow path member 90 Flow path 91e Flow path end portion 92 Bending flow path portion 92a Outer peripheral side peripheral surface portion 92b Inner peripheral side peripheral surface portion (undercut)
97 Connection part 97 (curved flow path part)
97b Inner circumference side surface part (undercut)
L axis direction R ₄₁ radius of curvature φ ₄₁ outer diameter

Claims (6)

A mold device for injection molding a flow path member having a flow path including a curved flow path part,
An outer peripheral molding die for molding the outer peripheral surface of the flow path member,
A flow path molding die for molding the flow path in the flow path member,
, The flow path molding die,
A first core pin that extends in the axial direction and is moved back and forth between a molding position on the distal end side and a retracted position on the proximal end side along the axial direction;
A second core pin extending along the first core pin, the second core pin having an inner peripheral molding portion for molding a peripheral surface portion on the inner peripheral side of the inner peripheral surface of the flow path;
When the first core pin retracts from the molding position to the retracted position, the interlocking mechanism that shifts the second core pin to the side opposite to the inner circumference side and then retracts the second core pin,
And the interlocking mechanism is provided on one of the first and second core pins so as to extend in an inclination direction that is inclined toward the tip end side with respect to the axial direction and opposite to the inner circumference side. An inclined guide and a slide engagement portion provided on the other of the first and second core pins, the inclination guide and the slide engagement portion are slidably engaged in the inclination direction,
A mold apparatus, wherein an inclination angle of the inclination direction with respect to the axial direction is 0.5° to 15°.   The radius of curvature of the inner circumference of the curved flow passage molding portion that molds the curved flow passage portion in the inner circumference molding portion is 0.15 times the outer diameter of the cross section orthogonal to the axis of the curved flow passage molding portion. The mold apparatus according to claim 1, wherein the mold apparatus has a ratio of up to 1.7 times.   A ring portion is formed at one location in the axial direction of the first core pin, the outer peripheral surface of the ring portion constitutes a molding surface of the entire inner circumference of a predetermined portion of the flow path, and the second core pin is The mold device according to claim 1 or 2, which is inserted through the ring portion. The first core pin has an outer peripheral molding portion that molds a peripheral surface portion on the outer peripheral side of the inner peripheral surface of the flow path,
A part of the ring portion in the circumferential direction is integral with the outer periphery molding portion,
A partial annular portion excluding the part of the ring portion is projected from the outer periphery molding portion to the inner periphery side,
The mold device according to claim 3, wherein the second core pin is inserted between the inner peripheral surface of the partial annular portion and the outer peripheral molding portion. A stopper portion projecting from a peripheral surface of the inner circumference molding portion is formed on a base end side of the ring portion of the second core pin,
The mold apparatus according to claim 3, wherein the ring portion abuts on the stopper portion while the first core pin is retracting. A method for manufacturing a flow channel member having a flow channel including a curved flow channel section by the mold device according to claim 1.
A step of supplying a resin to a cavity defined between an outer peripheral molding die and a flow path molding die of the mold device to mold the flow path member;
A retracting step of retracting the first core pin of the flow path molding die from the molding position at the time of molding to the retracted position on the base end side in the axial direction;
A second core pin having an inner peripheral molding portion that molds a peripheral surface portion on the inner peripheral side of the inner peripheral surface of the flow channel in the flow channel molding die is interlocked with the first core pin when retracted by an interlocking mechanism. Then, an interlocking step of moving back to the opposite side of the inner circumference side and then retracting,
And a shift amount of the second core pin with respect to a retracted amount of the first core pin is tan 0.5° times to tan 15° times.

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