JP3205508B2 - Synthetic resin intake manifold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for abutting synthetic resin halves and filling a molten resin into an internal passage formed along the periphery of the abutting portion. The present invention relates to a synthetic resin intake manifold obtained by joining halves.

[0002]

2. Description of the Related Art Conventionally, as a method of forming a tubular body such as a pipe made of synthetic resin, a half body made of synthetic resin is abutted, and an internal passage formed along a peripheral edge of the abutting portion. A method of obtaining a hollow molded article as a tubular body by joining the above-mentioned halves by filling a molten resin therein is known. In addition, there is known a method in which when the halves are joined, filling of the internal passage with the molten resin is performed in a predetermined mold (for example, in a molding die for molding the halves). I have.

[0003] For example, Japanese Patent Publication No. 2-38377 basically provides a male mold part and a female mold part for molding a set of half bodies in one mold, and the other mold. A pair of mold structures in which a female mold portion and a male mold portion opposed to these mold portions are provided in a mold are disclosed, and by using such a mold, each half body can be simultaneously formed. After molding (injection molding), one mold is slid with respect to the other, thereby abutting the halves remaining in the female mold parts, and applying a molten resin to the periphery of the abutting part. There has been disclosed a method in which the two are joined by injection (a so-called die slide injection (DSI) method).

[0004] For example, Japanese Patent Publication No. 7-4830 basically discloses a mold that is openably and closably combined with one another, wherein one mold is rotatable by a predetermined angle with respect to the other. A mold structure for rotary injection molding, in which a mold is provided with at least one male mold part and two female mold parts in a repetition order of male / female / female in the rotation direction at the predetermined angle. Is disclosed, and by using such a mold, every rotation (for example, forward / reverse) operation,
A method of forming each half-piece and joining the abutted pair of half-pieces so that a finished product is obtained for each rotation operation (so-called die-rotary injection (D)
RI) method).

[0005]

By the way, when the molten resin (so-called secondary resin) for joining the two halves together in a predetermined mold and then joining them together is filled in the internal passage, the internal passage is not filled. If there is a part that comes in contact with the mold surface, the secondary resin loses its heat at this contact part and the fluidity decreases as the temperature decreases, and the secondary resin spreads sufficiently throughout the internal passage. In filling, trouble may occur. In addition, the secondary resin may protrude from the contact portion between the internal passage and the mold surface to form burrs, and there is a problem that the appearance is not preferable.

In addition, for example, in a manifold, each part of an internal passage can be filled with a secondary resin without increasing the number of gates.
Further, it is conceivable to form the internal passage in a closed loop so that the internal passage can be prevented from being exposed to the pipe end face. In this case, the tubular body is formed with a portion along the longitudinal axis and the pipe end. The division direction is different for each part. Therefore, the sectional shape of the internal passage also changes suddenly, and it becomes difficult to flow the secondary resin smoothly.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and is intended for a method in which a pair of halves are abutted in a predetermined mold, and then a secondary resin is filled into an internal passage and joined. It is another object of the present invention to provide a synthetic resin intake manifold having an internal passage through which the temperature of the secondary resin can be prevented from lowering and through which the secondary resin can flow smoothly.

[0008]

For this reason, the synthetic resin tubular body of the invention according to claim 1 of the present application (hereinafter referred to as the present invention) has a structure in which a pair of synthetic resin halves are brought into abutment with each other. By filling the molten resin in a predetermined mold into an internal passage formed along the periphery of the abutting portion,
A synthetic resin intake manifold obtained by joining the halves together, wherein the intake manifold includes one inlet pipe and a plurality of outlet pipes, and the inlet pipe and each outlet pipe The part is set so as to form a substantially right angle, and the middle part in the longitudinal direction of the pipe and the vicinity of the pipe end on the inlet side are divided in the opening and closing direction of the mold, while the vicinity of the pipe end on the outlet side is It is configured by combining a pair of halves divided in a direction substantially perpendicular to the opening and closing direction. In the middle part in the longitudinal direction and near the pipe end on the inlet side, the peripheral wall of each half has a substantially U-shaped cross section that opens in the opening and closing direction, and the two halves are in opposition to each other. A first internal passage having a closed cross section is formed by being joined together. In the vicinity of the pipe end on the outlet side, the peripheral wall of each half has a substantially L-shaped cross section. The bodies are abutted against each other to form a second internal passage having a closed cross section.
The first and second internal passages are connected in an arc shape in the vicinity of the pipe end on the outlet side, and have a gently changing cross-section at the connection portion to form a closed-loop passage as a whole. It is like doing it.

[0009]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 10 to 21 show an intake manifold W which is a molded product according to the present embodiment. The intake manifold W
As can be clearly understood from FIGS. 10 to 13, for example, includes one inlet pipe Wi and a plurality (three in this embodiment) of outlet pipes Wo, and includes the inlet pipe Wi and each outlet pipe. Wo is set so as to form a predetermined angle (substantially a right angle in the present embodiment). As will be described later in detail, the molded article W is formed by, for example, a so-called die rotary injection (D).
RI) method, the upper and lower half halves W _{U in} one mold
And W _L are formed, respectively, and both W _U and W _L are abutted and joined in the forming die to obtain a hollow tubular body.

In the present embodiment, as can be clearly understood from FIG. 12, the molded product W is formed at the middle part in the longitudinal direction of the pipe and in the vicinity of one end of the pipe (the inlet pipe Wi). While being divided in the opening / closing direction (vertical direction in FIG. 12), a pair of half bodies W _U divided in a direction substantially perpendicular to the opening / closing direction near the other pipe end (outlet pipe Wo). , and it is composed of a combination of W _L. The parting line Lp indicating this dividing line is formed so as to avoid the pipe ends of the inlet pipe Wi and the outlet pipes Wo, that is, the parting line Lp.
so that p does not appear on the pipe end face, and the molded product W
Is set so as to form a closed loop along the periphery of. Incidentally, half body W _U, abutting surfaces of and what W _L will be formed along the parting line Lp. This parting line Lp
Is formed in a closed loop shape avoiding the pipe end,
The roundness of the tube end cylindrical portion can be increased. This makes it possible to maintain good sealing performance when assembled with the mating component. Further, in the present embodiment, preferably, each of the pipe ends of the inlet Wi and the outlet Wo is
Both, and it is molded integrally with the example above-half body (upper half) W _U side.

[0011] As best seen in FIGS. 14 to 16, along the closed loop (i.e., along the outer periphery of the abutment surface), is preferably formed in the wall of each half split body W _U, W _L was closed cross section grooved internal passage W _P is provided for, in the internal passage W in _P, the upper and lower half body W _U, for joining the two mutually the after abut each other and if W _L (Secondary resin).

Further, in the present embodiment, as shown in FIGS. 17 and 18, in the middle part in the axial direction and near the end of one of the pipes (the inlet pipe Wi in the present embodiment), each halved body W _U, together with the wall portion of the peripheral edge of the W _L has a substantially U-shaped cross section that opens to the mold opening and closing direction (the vertical direction in the drawing), both halved bodies W _U, W _L from each other The internal passage W having a closed cross section by being abutted
_P1 (first internal passage) is formed. The first internal passage W _P 1 is, as shown by a dashed-dotted line curve in FIGS. 20 and 21, excluding the vicinity of the end of the other pipe (three outlet pipes Wo in the present embodiment). Halves W _U ,
Constitute a passage portion of the periphery of the W _L.

On the other hand, the other pipe section (three outlet pipe sections Wo)
In the end portion, as it can be seen from FIG. 19, collision each halved body W _U, together with the wall portion of the peripheral edge of the W _L has a substantially L-shaped cross section, both halved bodies W _U, W _L from each other By being combined, an internal passage W _P 2 (second internal passage) having a closed cross section is formed. The second internal passage W _P 2 constitutes a semicircular passage near the ends of the three outlet pipes Wo, as shown by the dashed curves in FIGS. 20 and 21.

The first internal passage W _P 1 and the second internal passage W _P
2 and, as can be well understood from the shape near the edge of the outlet pipe portion Wo of the parting line L _P in FIG. 12 are connected in a circular arc shape, both internal passage W _P 1, W _P 2, the connection The cross section changes gradually in the part. In addition, a closed loop passage is formed as a whole. In the present embodiment, the gate portion _GP for injecting the secondary resin with respect to the internal passages W _P 1 and W _P 2 is, for example, as shown by a virtual line (two-dot chain line) in FIG. respectively provided in the vicinity of the connection portion between W _P 2 and the first internal passage W _P 1 of the right and left outer, inner passage W _P 1 from the gate portion G _P of the two places, W _P 2
The inside is sufficiently supplied and filled with the secondary resin.

As described above, according to the present embodiment, the molded article W as a tubular body is formed at an intermediate portion in the longitudinal direction of the pipe and at one end of the pipe (the pipe end of the inlet pipe Wi). ) Is divided in the opening and closing direction of the mold, while a pair near the other pipe end (the pipe ends of the three outlet pipes Wo) is divided in a direction substantially perpendicular to the opening and closing direction. half body W _U of, is constructed by combining W _L, also, since the internal passage W _P 1, W _P 2 is formed in a closed loop as a whole, to each part of the internal passage without particularly increasing the number of gates can filled with a secondary resin, also it can be avoided that the internal passages W _P 1, W _P 2 is exposed to the pipe end face. In the middle of each tube of the molded article W in the longitudinal direction and near the pipe end of one of the pipes (the inlet pipe Wi), the two halves W _U and W _L are brought into contact with each other by abutment. while shaped cross section is combined with cross-sectionally closed shape of the first internal passage W _P 1 is formed, the tube end near the other tube section (three outlet tube portion Wo), both halved bodies W _U, W _L how to combine a substantially L-shaped cross section by abutting a closed cross section shape of the second
Since the internal passages W _P 2 are formed, the internal passages W _P 1 and W _P 2 are formed.
Does not come into contact with the mold surface.

Accordingly, it is possible to prevent the temperature of the secondary resin from decreasing and the fluidity from decreasing, and it is possible to sufficiently fill and fill the entire internal passages W _P 1 and W _P 2 with the secondary resin. Thus, both halved bodies W _U, the bonding strength was how W _L can be sufficiently secured. Moreover, the internal passage W _P 1,
The secondary resin does not protrude from W _P 2, and the appearance of the molded article W can be kept good. Further, since the internal passages W _P 1 and W _P 2 are formed in a closed cross section,
Leakage of the secondary resin to the outside (mold side) of the internal passages W _P 1 and W _P 2 can be more reliably prevented, and the leakage of the secondary resin causes an increase in the pressing force from the outside to the inside of the pipe. It is possible to effectively prevent the pipe from falling down and the secondary resin from leaking into the pipe. In this case, the first and second internal passages W _P 1 and W _P 2 are connected in an arc shape, and the cross section changes gently at the connection portion, so that the secondary resin can flow smoothly. It is also possible to suppress a decrease in the filling property of the secondary resin due to a sudden change in the cross-sectional shape of the internal passages W _P 1 and W _P 2.

Next, the configuration of a molding die used for manufacturing (molding) the intake manifold W according to the present embodiment will be described. In the present embodiment, the intake manifold W is preferably formed by a so-called die rotary injection (DRI) method. FIGS. 1 to 5 are longitudinal sectional views of a mold for molding the intake manifold. As can be clearly understood from FIGS. 1, 2 and 5, the molding die includes a fixed die 1 connected to a molding machine (for example, an injection molding machine: not shown),
The fixed die 1 is provided with a rotating mechanism for rotating a predetermined portion including a molded portion thereof, as will be described in detail below. In FIGS. 1 to 5, the fixed mold 1 and the movable mold 2 are drawn in a vertically arranged state, but both molds 1 and 2 in a state where they are actually attached to a molding machine (not shown) are shown. The arrangement structure of 2 is not limited to the upper and lower sides, and may be used, for example, in a horizontal (left / right) direction.

The fixed die 1 is provided with a base board 11 fixed to the main body 10, a spool bush 12 fixed to the center of the base board 11 and the main body 10, and a coaxial arrangement with the spool bush 12. The injection head (not shown) of the molding machine is fixed to the spool bush 12. The rotor 13 is basically formed in a disk shape, and a central portion thereof protrudes in a columnar shape.
An opening is provided on the surface of the central projection 13a.

As can be clearly understood from FIG. 5, the outer peripheral portion of the rotor 13 is formed with a tooth portion 13g that meshes with the drive gear 14 disposed in the vicinity thereof. Drive gear 14
Is connected to a driving source 15 such as a hydraulic motor, and the driving gear 14 is rotated by the driving source 15 so that the rotor 13 rotates in a predetermined direction at a predetermined angle in accordance with the rotation direction and the number of rotations. (In this embodiment, 120 degrees).

On the other hand, the movable mold 2 includes a base board 31 disposed in parallel with the main body section 30 and a mold board 40 fixed to the main body section 30. Is provided. Note that the mold plate 40 is actually composed of a central cylindrical portion 40d and three block bodies surrounding the cylindrical portion 40d. The main body 30 and the base board 3
1 is connected to, for example, a hydraulic driving means (not shown) so that the opening and closing operation can be performed on the fixed mold 1 at a predetermined timing. Note that spacer blocks 32a and 32b (see FIG. 5) are interposed between the main body 30 and the base board 31. In addition, the movable mold 2 includes:
A slide mold 33 that slides along a mold plate 40 in a direction orthogonal to the opening and closing direction of the movable mold 2 and a rod-shaped slide guide 34 that drives the slide mold 33 in conjunction with the opening and closing operation of the movable mold 2 are provided. I have.

The slide die 33 corresponds to the outlet Wo of the molded product W, and has a core portion 33a (FIGS. 2 to 4).
Reference) corresponds to the inner peripheral portion at the tube end of the molded product outlet Wo. Further, regarding the inlet portion Wi of the molded product W, the core member 3 fixed to the main body support plate 35 of the movable mold 2
The tip portions of 6a and 36b correspond to each other. still,
As will be described later, the slide mold 33 and the slide guide 34 are provided in the movable mold 2 so as to form an upper half (upper half) W _U and a portion where the upper and lower halves W _U and W _L are abutted. Are provided at two locations where they are joined with a secondary resin.

A tapered portion 34c is formed at one end of the slide guide 34, and the tapered portion 34c
It is engaged with the tapered hole 33c of the slide die 33. On the other hand, the guide drive plate 3
The guide drive plate 37 is configured to engage with one of the slide guides 34. The guide driving plate 37 is
The back side is supported by a back plate 38, and a pair of guide rails 38a for guiding a sliding operation of the guide driving plate 37 along the back plate 38 is fixed to the back plate 38, as shown in FIG. ing.

The guide driving plate 37 is driven by a driving means 49 (see FIG. 5) such as a hydraulic cylinder in the direction along the back plate 38 to move along the guide rail 38a and slide. The state of engagement with the guide 34 (that is, which of the left and right slide guides 34 is engaged) is switched. The switching of the engagement state between the guide drive plate 37 and the slide guide 34 is performed in response to the turning operation of the rotor 13 by a control signal from a controller (not shown) of the molding apparatus. .

A piston rod 39 of, for example, a hydraulic drive cylinder (not shown) which expands and contracts in the same direction as the operating direction (opening / closing direction) of the movable mold 2 is provided on the back surface of the back plate 38. The slide guide 34 can be driven (moved forward / backward) via the back plate 38 and the guide drive plate 37 by the expansion / contraction operation of the piston rod 39. Ejector pins 47a, 47b, 47c and ejector rings 48a, 48b attached to the ejector plates 46a, 46b, 46c are provided inside the main body 30 of the movable die 2. Note that the ejector rings 48a, 48b is a tube end of the inlet Wi of the molded product W or upper half W _U to eject (push up) but each core member 36a, 36
It is arranged so as to surround the outer periphery of b.

The three ejector plates 46 (46)
a, 46b, 46c) are such that when the guide drive plate 37 is driven (moved forward) toward the main body 30 side of the movable mold 2, two projecting pins 37a projecting from the drive plate 37 The ejector plate 46 penetrates through each hole 35h of the main body support plate 35.
By pressing the back side of (46a, 46b, 46c), two of the three sheets are pushed up. Which two of the three ejector plates 46
Whether (46a, 46b, 46c) is pushed up is switched according to the engagement state between the guide drive plate 37 and the slide guide 34.

The slide guide 34 is at the initial position when the movable mold 2 is closed with respect to the fixed mold 1 (see FIG. 1), and does not exert a driving force on the slide mold 33. The slide die 33 is located at a molding position (a position corresponding to an inner peripheral portion of a tube end portion of the molded product outlet Wo). Further, after the molding process is completed, even when the mold is opened (see FIG. 2), the slide guide 34 is still at the initial position, and the slide mold 33 is maintained in the molding position.

Thereafter, as shown in FIG. 3, the slide guide 34 is driven (moves forward) toward the main body 30 of the movable mold 2. Thereby, the tapered hole 33c of the slide mold 33 is arranged along the tapered portion 34c of the slide guide 34,
The slide die 33 is slid outward, and the core portion 33a is pulled out of the pipe end at the outlet Wo of the molded product W. That is, the core portion 33 of the slide die 33 that slides in a direction (perpendicular to) the opening and closing direction of the movable die 2.
a is withdrawn from the pipe end (outlet Wo) of the finished product W.

When the slide guide 34 is further advanced, as shown in FIG.
The three protruding pins 37 a are provided in the three holes 3 of the main body support plate 35.
By ejecting the ejector plates 46a and 46b through two of them (the two on the right in the example of FIG. 4) out of 5h, the ejector pins 47a and 47b and the ejector rings 48a and 48b are operated. It has become. The fixed mold 1 is provided with, for example, hydraulically driven ejector pins 27a and 27b (see FIGS. 1, 2 and 5). In a series of operation examples shown in FIGS. When the mold is opened after the completion of the molding process (see Fig. 2)
The ejector pin 27a is protruded from the main body.

FIG. 6 is an explanatory front view showing the mold-matching surface side of the rotor 13 of the fixed mold 1. As shown in FIG. As shown in this figure, three mold plate blocks 20 are fixed to the rotor 13 around the center projecting portion 13a in a circumferentially equidistant shape (that is, at an angle of 120 degrees from each other), Each of these mold block 20 is provided with a molded part 20A, 20B or 20.
C is provided. The molded part 20C is a male part formed in a convex shape, and both the molded parts 20A and 20BC are female parts formed in a concave shape. That is, the rotor 13 of the fixed mold 1 includes one male mold part 20C and two female mold parts 20A and 20B.

It should be noted that there is no resin passage connected to each molding portion 20A, 20B, 20C provided on the rotor 13 of the fixed mold 1. However, on the surface of the central protruding portion 13a of the rotor 13, as described later, a group of long grooves is formed in order to switch the connection state between the resin passage connected to the molding portion on the movable mold 2 side and the spool 12a of the spool bush 12. (In the present embodiment, a total of five switching slots)
(21A, 21B, 21C) are provided. These switching slots 21 include a single switching slot 21C and a molding section 20C, and two parallel switching slots 21B and a molding section 2C.
0B, and the two parallel switching slots 20A are provided so as to point to the forming portion 20A, respectively.

As described above, the outer peripheral portion of the rotor 13 is provided with a tooth portion 13g meshing with the drive gear 14 for an arc length corresponding to at least an angle of 120 degrees. (That is, according to the rotation direction and the number of rotations), the rotor 13 is rotated by 120 degrees in a predetermined direction. The control of the rotation of the drive gear 14 (that is, the control of the rotation of the rotor 13)
This is performed by controlling a drive source 15 (see FIG. 5) such as a hydraulic motor. In the present embodiment, the rotor 13
Is set so as to be alternately rotated in a forward direction and a reverse direction by 120 degrees at a predetermined timing. For example, when the drive gear 14 rotates in the state of FIG.
3 rotates counterclockwise in FIG.

FIG. 7 is an explanatory front view showing the mold-matching surface side of the mold plate 40 of the movable mold 2. As shown in this figure, the mold plate 40 has three molded portions 40A, 40B, 4
0C are provided circumferentially equally (that is, at an angle of 120 degrees to each other). The molded part 40B is a male part formed in a convex shape, and the molded parts 40A and 40C are female parts formed in a concave shape. That is, the movable mold 2 includes one male mold part 40B and two female mold parts 40B.
A, 40C. Note that FIGS. 1 to 4 are longitudinal sectional explanatory views along the line A-C in FIG.
FIG. 5 is an explanatory longitudinal sectional view taken along line BB in FIG.

The mold 40 of the movable mold 2 has
Primary and secondary resin passages 41 (41A, 41B, 41C), 42 directly connected to 0A, 40B, 40C, respectively.
(42A, 42C) and two types of branched resin passages 43 formed in the central cylindrical portion 40d of the mold plate 40. The female mold 40A, 4
The 0C, second for joining joining half body (W _U, W _L) one for supplying primary resin for molding the primary resin passage 41A, and 41C, half body W _U are abutted, was what W _L Secondary resin passages 42A and 42C for supplying the next resin are connected. On the other hand, only the primary resin passage 41B is connected to the male mold 40B. Each of the primary resin passages 41 (41A,
41B, 41C) are the respective molded portions 40 (40A, 40B, 4).
0C) is connected to the side surface of the portion corresponding to the molded article inlet pipe Wi. In addition, each secondary resin passage 42 (42
A, 42C) are provided in pairs on both sides of each of the molded parts 40A, 40C, and are connected by providing a gate part 42g on the side surface of a part corresponding to the molded article outlet pipe Wo in each of the molded parts 40A, 40C. ing.

When the movable mold 2 is closed with respect to the fixed mold 1, the branch resin passage 43 branches from a center portion 43 d corresponding to the spool 12 a of the spool bush 12 as a base point. Primary and secondary resin passages 41 (41A, 41A) connected to the sections 40A, 40C.
C), 42 (42A, 42C), six branch portions are provided. Each branch portion is positioned so that its tip is separated from the one end of the corresponding resin passage by a predetermined distance on an extension thereof.

When the movable mold 2 is closed with respect to the fixed mold 1, the predetermined resin passage is formed into the branch resin passage 43 by the switching slot 21 provided in the rotor 13 of the fixed mold 1 (that is, the branch resin passage 43). , Spool 12 a), and this connection state can be switched by rotation of the rotor 13. The primary resin passage 41B connected to the male molded portion 40B is directly connected to the branch resin passage 43 (to the center portion 43d). Therefore,
The aforementioned molding portion 40B, regardless of the rotational position of the rotor 13, at all times, so that molding the supplied primary resin lower half W _L.

A process of forming the intake manifold W, which is performed by using the above-configured forming die, will be described. First, as an initial state, when the fixed mold 1 is combined with the movable mold 2 in the state shown in FIG. 6, the combination of the molding portions of these two molds 1 and 2 is as follows. Molding part 40A (female mold) of movable mold 2 / molding part 20A of fixed mold 1 (female mold) Molding part 40B of movable mold 2 (male mold) / molding part 20B of fixed mold 1 (female mold) Movable Molded part 40C of mold 2 (female mold) / molded part 20C of fixed mold 1 (male mold)

At this time, the switching slot 21 of the rotor 13 of the fixed die 1 is at the rotation position indicated by the broken line in FIG. That is, the pair of switching slots 21A is
Each of the secondary resin passages 42A and the branch resin passages 43 communicates with the molding portion 40A of the second member 40A, while the switching slot 21C
Is the primary resin passage 41 with respect to the molding portion 40C of the movable mold 2.
C and the branch resin passage 43 are communicated. In addition, movable mold 2
The primary resin passage 41B for the molding portion 40B is always in communication with the branch resin passage 43.

Therefore, in this state, when the movable mold 2 is closed with respect to the fixed mold 1 (see FIGS. 1 and 5), the mold is clamped, and a molten resin is injected from a molding machine (not shown).
The molten resin is supplied to the branch resin passage 4 via the spool 12a.
The resin is supplied to each of the resin passages 42A, 41C, 41B communicating with the third resin passage 3. In this embodiment, as the material resin, for example, a nylon resin mixed with a glass reinforcing fiber was used. As a result, in the molding cavity in which the molding portions of the fixed mold 1 and the movable mold 2 are combined, the following molded body is molded. And forming section 40A (female) / molding portion 20A (female): finished product W · forming portion 40B (male) / molding portion 20B (female): lower half W _L-shaped portion 40C (female) / molding Part 20C (male type): Upper half W _U

In the case of the first injection step, the molding section 4
0A (female mold) / molded cavity formed by molding section 20A (female mold) has a molded half-split body (upper half W).
Since _U and lower half W _L) is not present, after setting the dummy with the upper half W _U and lower half W _L and the same outer shape as that by abutting the injection of the molten resin is performed. Further, the guide driving plate 37 is always provided with the finished product W
Guide 34 engaging with slide mold 33 for
(The slide guide 34 on the right side in the examples of FIGS. 1 to 4) is set so as to engage with the concave portion 34 d.

At the time of this injection step, the molding part 40A of the movable mold 2
Incidentally secondary resin filled in each of the secondary resin passage 42A for, in this case, abutting primary resin passage 41A connected to the molding portion 40A is half body W _U, and if W _L is in a mold In this case, the internal passages W _P 1 and W _P 2 are shut off. After the injection step, the movable mold 2 is retracted from the fixed mold 1 to open the mold (see FIG. 2). At this time, the ejector pin 27a on the fixed mold 1 side is protruded,
The finished product W does not remain on the fixed mold 1 side.

In the present embodiment, as described above, the molded product W is formed in the middle of the longitudinal direction of each pipe and in the vicinity of one pipe end (the pipe end of the inlet pipe Wi). , 2
In the vicinity of the other pipe end (the pipe end of the outlet pipe Wo), it is divided in a direction substantially perpendicular to the opening / closing direction (see, for example, FIG. 12). The parting line Lp indicating this dividing line is formed so as to avoid the pipe ends (the inlet part Wi and each outlet part Wo), that is, the parting line Lp
Is set so as not to appear on the pipe end face, and to form a closed loop along the periphery of the molded article W. Incidentally, half body W _U, abutting surfaces of and what W _L will be formed along the parting line Lp. Further, in the present embodiment, preferably, the entrance Wi and the exit W
each tube end portion of the o are both adapted to be molded integrally with the example above-half body (upper half) W _U side.

In this embodiment, the upper half W
_U and lower half W _L, in the vicinity of the end portion of the middle portion and the inlet tube portion Wi in the longitudinal direction of the tube, each half split body W _U,
Walls of the peripheral edge of the W _L is formed with a substantially U-shaped cross section which opens the opening and closing direction of the mold. On the other hand, the upper half W _U and the lower half W _L may have three in the vicinity of the end portion of the outlet tube portion Wo, each halved body W _U, W _L wall portion substantially L-shaped cross section of the periphery of the molding Have been. By abutting the the upper half W _U and lower half W _L with each other. In the vicinity of the end portion of the middle portion and the inlet tube portion Wi in the longitudinal direction of the pipe, the first internal passage of the cross-sectionally closed shape W _P 1 (FIG. 17 and Figure 18 reference) whereas is formed, three in the vicinity of the end portion of the outlet tube portion Wo, the second internal passage of the cross-sectionally closed shape W _P 2 (FIG. 19
Reference) is formed. Also, at the time of this collision, the first
The cross sections of the two internal passages W _P 1 and W _P 2 change gently at the connecting portions thereof, and form a closed loop passage as a whole.

[0043] By configuring the internal passage W _P 1, W _P 2 Thus, the respective portions of the internal passage without particularly increasing the number of gates can fill the secondary resin, also, the interior passage W _P 1, W _P 2
Can be prevented from being exposed on the pipe end face. Further, since the internal passages W _P 1 and W _P 2 are formed in a closed cross section, the secondary resin in the internal passages W _P 1 and W _P 2 does not come into contact with the surface of the molding die. The temperature decrease of the secondary resin can be suppressed. In addition, the secondary resin does not protrude from the internal passages W _P 1 and W _P 2, and the appearance of the molded article W is also kept good. Furthermore, both the first and second internal passage W _P 1, W _P 2, since moderately cross-section varies in its connection part, the secondary resin flows smoothly, the internal passage W _P 1, W _P 2 Of the secondary resin due to a sudden change in the cross-sectional shape of the resin can also be suppressed.

Next, by moving the piston rod 39 forward, the slide guide 34 engaged with the slide die 33 for the finished product W is advanced (see FIG. 3), and the finished product W
The core portion 33a of the slide die 33 is pulled out from the outlet tube portion Wo of the finished product W. In this manner, the core 33a of the slide die 33 that slides in a direction (perpendicular to) the opening and closing direction of the molding die (movable die 2) can be removed from the finished product W.

By further moving the slide guide 34 forward, each projecting pin 37a of the guide drive plate 37 is moved.
Then, the corresponding ejector plates 46a, 46b are pushed up, and the ejector pins 47a, 47b and the ejector ring 48a are actuated (thrusting operation). Thereby, the core member 36a is withdrawn from the inlet pipe Wi of the finished product W, and the finished product W is released from the movable mold 2 and can be taken out of the mold (FIG. 4). reference). In this manner, for the two pipe ends (the inlet pipe Wi and the outlet pipe Wo) forming the angle of the finished product W, the core material (the core member 36a and the slide-type core 33a) corresponding to the inner periphery thereof. Can be withdrawn without any trouble, and the finished product W can be taken out.

On the other hand, the forming part 40B (male type) and the forming part 20
B is lower half W _L molded with formed cavity (female mold) is left in the molding portion 20B of the fixed mold 1, also formed by molding portion 40C (female) / molding portion 20C (male) Upper half W _U molded in cavity is movable mold 2
Is left in the molding part 40C. Then, the rotor 13 of the fixed die 1 is moved in the direction indicated by the arrow in FIG.
After being rotated by the degree, the movable mold 2 is advanced and closed with respect to the fixed mold 1 to perform mold clamping. still,
At this time, the guide driving plate 37 is slid along the guide rail 37a of the back plate 37,
The engagement with the right slide guide 34 in FIG. 4 is released, and this time the recess 34d of the left slide guide 34 is released.
Is adapted to be engaged.

By combining the fixed mold 1 in the rotating state with the movable mold 2, the combination of the molding portions of the two molds 1 and 2 is as follows. -Molding part 40A (female mold) of movable mold 2 / molding part 20C of fixed mold 1 (male)-Molding part 40B of movable mold 2 (male) / molding part 20A of fixed mold 1 (female mold)-Movable type 2 of the molding portion 40C (female) / molding portion 20B (female) of the fixed mold 1 at this time, as described above, the lower half W _L is the molding portion 20B of the fixed mold 1, forming part of the movable mold 2 upper half W _U to 40C it is, since the left respectively, by the rotation of the rotor 13, and the upper half W _U and lower half W _L is out with the molding portion 40C (female) and molding portion 20B (female) It will be abutted in the cavity formed.

Further, at this time, the switching slot 21 of the rotor 13 of the fixed type 1 is at the rotation position indicated by a broken line in FIG. That is, the switching slot 21C allows the primary resin passage 41A and the branch resin passage 43 to communicate with the molding portion 40A of the movable mold 2, while the switching slot 21B
Are the respective secondary resin passages 4 with respect to the molding portion 40C of the movable mold 2.
2C communicates with the branch resin passage 43. The primary resin passage 41B for the molding portion 40B of the movable mold 2 is always in communication with the branch resin passage 43.

Therefore, in this state, the movable mold 2 is closed to the fixed mold 1 (see FIGS. 1 and 5), the mold is clamped, and the molten resin is injected from a molding machine (not shown).
The molten resin is supplied to the branch resin passage 4 via the spool 12a.
3 are supplied to the resin passages 41A, 42C, 41B. As a result, in the molding cavity in which the molding portions of the fixed mold 1 and the movable mold 2 are combined, the following molded body is molded. -Molding part 40A (female type) / Molding part 20C (male type): Upper half W _U Molding part 40B (male type) / Molding part 20A (female type): Lower half W _L -Molding part 40C (female type) / molding Part 20B (female type): finished product W In addition, in the molding part 40B (male type) of the movable die 2, the rotor 13
Regardless of the rotation state, always, so that the lower half W _L is molded.

Thereafter, the mold is opened to take out the finished product W. In this rotor rotation state, the left slide guide 34 in FIGS. 1 to 4 is driven, and the left two ejector plates 46a, 46b, 46c (46b, 46c) are driven. At this time, the lower half W _L is the molding portion 20A of the fixed mold 1, the molding portion 40A of movable die 2 the upper half W _U is, so that the left, respectively.

Then, in this state, the rotor 13 is rotated in the reverse direction by 120 degrees to perform mold clamping, thereby returning to the initial state (see FIG. 4), and repeating the same steps to form one completed product. W is obtained. That is, by repeating the forward rotation and the reverse rotation of the rotor 13 of the fixed mold 1 every 120 degrees, the mold clamping, the injection and the mold opening are performed each time, so that one rotation operation of the rotor 13 is performed for one rotation operation. The molded article W can be obtained.

In the molded article W thus obtained, since the internal passages W _P 1 and W _P 2 have a closed cross section, the secondary resin does not come into contact with the molding die surface. Therefore, a decrease in the temperature of the secondary resin, that is, a decrease in the fluidity can be suppressed, and the entirety of the internal passages W _P 1 and W _P 2 is filled with the secondary resin by spreading sufficiently, so that the two halves W _U and W It is possible to sufficiently secure the bonding strength between _L. Moreover, the internal passages W _P 1 and W _P 2
The secondary resin does not protrude from and does not form burrs,
The appearance of the molded article W can also be kept good. Further, since the first and second internal passages W _P 1 and W _P 2 change their cross sections gently at their connection portions, the secondary resin can flow smoothly, and the internal passages W _P 1 and W _P 2 It is possible to suppress a decrease in the filling property of the secondary resin due to a sudden change in the cross-sectional shape of W _P 2.

Although the above embodiment is directed to an intake manifold formed by a so-called DRI method, the present invention is not limited to such a case. For example, the so-called DSI method or other Even when molded by a general molding method, it can be applied effectively. Further, the present invention is not limited to the above-described embodiment, and it goes without saying that various improvements or design changes can be made without departing from the gist of the present invention.

[0054]

According to the present invention, the intake manifold is divided at an intermediate portion in the longitudinal direction of the pipe and in the vicinity of the pipe end on the inlet side in the opening and closing direction of the mold, while the pipe end on the outlet side is formed. In the vicinity of the part, the half passage divided in a direction substantially perpendicular to the opening and closing direction is configured by combining the internal passages, and since the internal passage is formed in a closed loop as a whole, the internal passage is formed without increasing the number of gates. Each part can be filled with a secondary resin, and the internal passage can be prevented from being exposed at the pipe end. In the longitudinal direction of each pipe of the intake manifold and in the vicinity of the pipe end on the inlet side, the substantially U-shaped cross sections are combined by abutting the two halves to form a closed cross-section. While the first internal passage is formed, in the vicinity of the pipe end on the outlet side, the substantially L-shaped cross sections are combined by abutting the two halves to form the second internal passage having a closed cross section. Since it is formed, the internal passage does not contact the mold surface. Therefore, it is possible to suppress a decrease in the fluidity due to a decrease in the temperature of the secondary resin, and it is possible to sufficiently fill and fill the entire internal passage with the secondary resin. As a result, a sufficient joining force between the two halves can be secured. In addition, the secondary resin does not protrude from the internal passage, and the appearance of the molded article (tubular body) can be kept good. Furthermore,
Since the internal passages (both the first and second internal passages) are formed in a closed cross section, the leakage of the secondary resin to the outside of the internal passages (the mold surface side) can be more reliably prevented, and the pipes caused by such leakages can be prevented. It is possible to effectively prevent the pipe from collapsing and the secondary resin from leaking into the pipe due to an increase in the pressing force from the outside. In this case, the first and second internal passages are connected in an arc shape near the pipe end on the outlet side, and the cross section changes gently at the connection portion. And a decrease in the filling property of the secondary resin due to a sudden change in the cross-sectional shape of the internal passage can be suppressed.

[Brief description of the drawings]

FIG. 1 is an explanatory longitudinal sectional view along a line A-C in FIG. 7, showing a state in which a molding die according to an embodiment of the present invention is clamped.

FIG. 2 is an explanatory longitudinal sectional view similar to FIG. 1, showing a mold opening state of the molding die.

FIG. 3 is an explanatory longitudinal sectional view similar to FIG. 1, showing a slide die driving state of the molding die.

4 is an explanatory longitudinal sectional view similar to FIG. 1, showing an ejector mechanism driving state of the molding die.

FIG. 5 is an explanatory longitudinal sectional view taken along line BB in FIG. 7, showing a closed state of the molding die.

FIG. 6 is an explanatory front view of a stationary rotor of the molding die.

FIG. 7 is an explanatory front view of a movable mold of the molding die.

FIG. 8 is an explanatory front view for explaining a switching state of the movable resin passage.

FIG. 9 is an explanatory front view for explaining a switching state of the movable resin passage.

FIG. 10 is an explanatory plan view of a molded product according to the embodiment of the present invention.

FIG. 11 is an explanatory front view of the molded article.

FIG. 12 is an explanatory side view of the molded article.

FIG. 13 is an explanatory vertical sectional view of the molded product taken along a line DD in FIG. 11;

14 is an explanatory longitudinal sectional view of the molded product taken along line EE in FIG. 10;

FIG. 15 is an enlarged explanatory view of a portion F of FIG. 13 of the molded product.

FIG. 16 is an enlarged explanatory view of a portion G in FIG. 13 of the molded product.

FIG. 17 is an enlarged vertical cross-sectional explanatory view showing a structure of a first internal passage of the molded product.

FIG. 18 is an enlarged vertical sectional explanatory view showing a structure of a first internal passage of the molded article.

FIG. 19 is an enlarged vertical cross-sectional explanatory view showing a structure of a second internal passage of the molded product.

FIG. 20 is an explanatory plan view schematically showing the arrangement of internal passages of the molded article.

FIG. 21 is an explanatory front view schematically showing the arrangement of internal passages of the molded article.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fixed mold 2 ... Movable mold 13 ... Rotor 20C ... Molded part 40A, 40B, 40C ... Movable mold side 42 ... Secondary resin passage W ... Intake manifold (synthetic resin tubular body) Wi ... Inlet pipe WL _L Lower half Wo Outlet pipe W _P1 First internal passage W _P2 Second internal passage W _U Upper half

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-246781 (JP, A) JP-A-3-230924 (JP, A) JP-A-7-246654 (JP, A) (58) Survey Field (Int.Cl. ⁷ , DB name) B29C 65/70 B29C 45/00-45/84 F02M 35/104

Claims (1)

(57) [Claims] 1. A pair of synthetic resin halves are abutted against each other, and a molten resin is filled in a predetermined mold into an internal passage formed along the periphery of the abutting portion. A synthetic resin intake manifold obtained by joining the halves together, wherein the intake manifold includes one inlet pipe portion and a plurality of outlet pipe portions each having a cylindrical pipe end. The inlet pipe section and each outlet pipe section are set so as to form a substantially right angle, and the middle part in the longitudinal direction of the pipe and the vicinity of the pipe end on the inlet side are divided in the opening and closing direction of the mold. On the other hand, in the vicinity of the pipe end on the outlet side, it is configured by combining a pair of halves divided in a direction substantially perpendicular to the opening and closing direction, and in the middle in the longitudinal direction and near the pipe end on the inlet side. Then each half A wall having a substantially U-shaped cross-section opening in the opening and closing direction, and a first internal passage having a closed cross-section formed by abutting the two halves against each other; In the vicinity of the side pipe end, the peripheral wall of each half has a substantially L-shaped cross section, and the two halves are brought into contact with each other to form a second internal passage having a closed cross section. The first and second internal passages are connected in an arc shape in the vicinity of the pipe end on the outlet side, and have a gently changing cross-section at the connection portion, so that a closed loop passage as a whole is formed. An intake manifold made of a synthetic resin, characterized in that the intake manifold is formed.