JPH1018923A - Structure for synthetic-resin-made intake manifold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent the loosening of an abutting part due to resin pressure, when molten resin is packed into an inside passage along the peripheral edge of the abutting part between half bodies. SOLUTION: In the structure of a synthetic-resin-made intake manifold obtained by abutting mating synthetic-resin-made half bodies WU and WL to pack molten resin into an inside passage WP along the peripheral edge of a abutting part, thus joining mating half bodies, the half bodies are fitted with each other, which the mating step part SU and SL of the respective half bodies are combined in the inner side of the inside passage of the part, and mating engaging parts KU and KL, for engaging a back up member 2K supporting the abutting part from the back surface side at the time of packing the molten resin into the inside passage, are provided on the back surface side of the abutting part of the respective half bodies. Also, the engaging part is to be a groove part provided along the peripheral edge of the abutting part, or is to be plural pin holes provided along the peripheral edge of the abutting part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an intake manifold made of a synthetic resin for an internal combustion engine, and more particularly, to a structure in which halves made of a synthetic resin are abutted and formed along the periphery of the abutting portion. The present invention relates to a structure of a synthetic resin intake manifold obtained by joining the above-mentioned halves by filling a molten resin into an internal passage.

[0002]

2. Description of the Related Art Conventionally, as a method for molding a synthetic resin hollow product, synthetic resin halves are abutted with each other and melted in an internal passage formed along the periphery of the abutting portion. A method of obtaining a hollow molded product by joining the above-mentioned halves by filling a resin is known. Further, a method is known in which, when joining the halves, the molten resin can be filled into the internal passage in a molding die for molding the halves.

For example, Japanese Patent Publication No. 2-38377 discloses that one mold is basically provided with a male molding part and a female molding part for molding a set of half halves, and the other metal 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 a molding part comprising at least one male molding part and two female molding 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 body and joining a pair of abutted half bodies so that a finished product can be obtained for each rotation operation (so-called die rotary injection (D
RI) method).

By the way, as is well known, an intake manifold is connected to a cylinder head of an engine in order to supply intake air to a combustion chamber of each cylinder. This intake manifold is a quite large part even in the intake system, and for further weight reduction around the engine,
Instead of conventional light alloys (such as aluminum alloys),
It is considered to be formed of a synthetic resin. In the case of the intake manifold, the temperature of the intake system is lower than that of the exhaust system, and it is possible to apply synthetic resin (especially synthetic resin reinforced with fibers etc.). Since it receives continuous vibration input from etc., it is necessary to pay sufficient attention to its molding in order to secure reliability for long-term use.

[0006]

By the way, when molding a hollow article made of synthetic resin, molten resin is injected into the internal passage formed along the periphery of the abutting portion between the pair of halves as described above. When the method of filling and joining both is adopted, when the molten resin for joining the two halves is filled into the internal passage of the abutting portion, the resin pressure is used to, for example, divide the half into an unsupported hollow side. There is a case where the abutting portion is loosened due to deformation of the resin, and the molten resin in the internal passage leaks to the periphery such as the hollow side. In such a case, it is difficult to ensure sufficient bonding strength, and in particular, in the case of the above-mentioned synthetic resin intake manifold, there is a problem that a problem may occur in maintaining reliability for long-term use. there were.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned technical problems, and a molten resin is filled in an internal passage formed along a peripheral edge of an abutting portion between a pair of halves. An object of the present invention is to provide a structure of an intake manifold made of synthetic resin, which can surely prevent looseness of the abutting portion due to the pressure of the molten resin when joining the two.

[0008]

For this reason, the invention according to claim 1 of the present application (hereinafter referred to as the first invention) abuts a pair of synthetic resin halves, and The structure is a synthetic resin intake manifold obtained by joining the half-divided bodies together by filling a molten resin into an internal passage formed along the peripheral edge of the portion, wherein the half-divided body is Inside the inner passage of the abutment portion, the respective stepped portions are combined and fitted to each other, and the back side of the abutment portion of each half is filled with the molten resin in the internal passage. In this case, there is provided an engaging portion for engaging a backup member for supporting the abutting portion from the back side.

The invention according to claim 2 of the present application (hereinafter,
The second invention) is characterized in that, in the first invention, the engaging portion is a groove portion provided along a peripheral edge of the abutting portion.

[0010] Further, the invention according to claim 3 of the present application (hereinafter referred to as "the invention")
According to a third aspect of the present invention, in the first aspect, the engaging portion is a plurality of pin holes provided along the periphery of the abutment portion.

[0011] Further, the invention according to claim 4 of the present application.
(Hereinafter, referred to as a fourth invention) is a molding die according to any one of the first to third inventions, in which each of the half-divided bodies is openably and closably combined with each other. Can be rotated by a predetermined angle with respect to each mold, and in each of the molds, in the rotation direction at each of the predetermined angles, in a male / female / female repeating order
It is molded by a rotary injection molding mold having at least one male mold part and two female mold parts, and the inside of the internal passage is filled with molten resin in the same mold. It is characterized by being performed in.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An intake manifold for an engine intake system according to an embodiment of the present invention will be described below.
A detailed description will be given with reference to the accompanying drawings. 10 to 1
In FIG. 6, an intake manifold W which is a molded product according to the present embodiment is shown. The intake manifold W includes, for example, one inlet portion Wi and a plurality (three in the present embodiment) of outlet portions Wo, and the inlet portion Wi and each outlet portion Wo have a predetermined angle (in the present embodiment). (In the form, almost right angle)
Is set to make. This shaped article W, as will be described later in detail, for example, by a so-called die rotary injection (DRI) method, one of the upper and lower at the mold half body W _U and W _L along with shaping each MOLDED by bonding by abutting both W _U and W _L in the mold, it is obtained as a hollow tubular body.

In the present embodiment, as can be seen clearly from FIG. 12, the mold parting line Lp of the molded product W is arranged so as to avoid the pipe end parts (the inlet part Wi and each outlet part Wo), that is, the mold parting line Lp. Is set so as not to appear on the end surface of the pipe and to form a closed loop along the periphery of the molded product W. The abutting surface of the half-split bodies W _U and W _L is formed along the mold dividing line Lp. By forming the mold parting line Lp in a closed loop shape that avoids the pipe end portion, the roundness of the pipe end cylindrical portion can be increased. As a result, it is possible to maintain good sealing performance in the assembled state with the mating component. Further, in the present embodiment, preferably, each of the pipe end portions of the inlet portion Wi and the outlet portion Wo is, for example, an upper half body (upper half) W.
It is designed to be integrally molded on the _U side.

[0014] 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). In the present embodiment, as can be seen from FIG. 16, it is preferable that the lowermost part of the internal passage W _P has a very limited length in the center of the three outlets Wo of the molded product W. It is possible to confirm the filling degree of the secondary resin in the internal passage W _P by observing the filling degree of the resin (secondary resin) at this opening portion (for example, about 10 mm at the maximum). It is like this.

[0015] In this embodiment, the internal passage W _P both halved body is filled with a molten resin (secondary resin) in W _U, when joining and if W _L, abutment by pressure of the molten resin to the loosening reliably prevented, the semi-split body W _U, W _L
, In the inner side than the internal passage W _P of the abutment, each of the step portion S _U, are combined is what S _L (see FIGS. 14 to 16) adapted to fit into each other. Therefore,
When filling both halved bodies W _U, the secondary resin for joining W _L inside passage W _P, it can be restricted from leaking to the inside of the molten resin in the passageway W _P. That is, it is possible to effectively deal with inward leakage that is generally difficult to inspect.

Further, in this embodiment, as best seen in FIG. 14, the abutment back side of each half split body W _U, W _L, the secondary resin is filled into the internal passage W in _P When
Engagement portions K _U and K _L are provided for engaging a backup member that supports the abutment portion from the back side. 17, the engaging portion K _U, but is an enlarged cross-sectional view for explaining the K _L,
FIG 17 and FIG. 10 or the like, the upper-half body (upper half) W _U engaging portion K _U of is configured as a groove portion provided along the periphery of the abutment. Preferably, the groove _KU is continuous. Then, this groove portion (engaging portion K _U), the upper half W _U to be formed on the mold 2 corresponding (movable mold to be described later) a vertical wall-shaped backup unit 2 _K is adapted to be engaged .

Meanwhile, the engaging portion K _L of the lower half body (lower half) W _L is configured as a plurality of pin holes provided along the periphery of the abutment. Arrangement position of the pin hole K _L is shown by a broken line circle in FIG. 10. Then, this pin hole (the engaging portion K _L), the lower half W mold 13 corresponding to the _L (fixed rotor to be described later) which is formed in backup pins 13 _K is adapted to engage. These backup pins 13 _K are preferably
From the tip side toward the base side has a reduced diameter small amount, so-called, is formed in a reverse tapered shape, against the action of the resin pressure in the internal passage W _P, than from its rear side abutments It can be strongly supported. The degree of this reverse taper is
During mold opening, the backup pins 13 _K is as it is pulled out from the pin holes K _L, are set so that exit without any trouble at some forced venting.

As described above, since the engaging portions K _U and K _L are provided on the rear surface side of the abutting portion of each of the halves W _U and W _L ,
Engaging portion K _U, with the abutments in K _L back up member for supporting the side (vertical wall-shaped backup unit 2 _K, backup pins 13 _K) engaging the secondary into the internal passage W _P Even if the resin pressure is applied when the resin is filled, loosening of the abutment portion can be reliably prevented. As a result, the joint strength between the halves W _U and W _L can be secured, and the reliability of the intake manifold W for long-term use can be maintained.

In this case, the vertical wall-shaped backup portion 2 _K that engages with the groove portion K _U and the backup pin 13 _K that engages with the pin hole K _L are combined. on the back side of the abutment body W _L, it is only several pin holes K _L remains, the engaging portion is less conspicuous as compared with the case remain in the molded product W as groove K _U, of the molded article W It is possible to stop the influence on the external appearance. Therefore, for example, as shown in FIG. 18, both the half-pieces W _U ′ and WL _L ′ are provided with a pin-hole-shaped joint portion K ′ so that the resin pressure acting in the internal passage W _P ′ can be reduced. Alternatively, loosening of the abutment portion may be reliably prevented.

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. 1 to 5 are longitudinal cross-sectional explanatory views of a forming die for forming 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 its molding portion, 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 No. 2 is not limited to the upper and lower sides, and may be used so as to be opposed to each other in the horizontal (left and right) direction, for example.

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 center of 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 the central portion thereof projects in a cylindrical shape. The spool 12a of the spool bush 12 is
An opening is provided on the surface of the central projection 13a.

As can be seen from FIG. 5, the outer peripheral portion of the rotor 13 is formed with a tooth portion 13g which meshes with the drive gear 14 arranged in the vicinity thereof. The 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. It 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. There is.

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 is used.
The tips 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 taper portion 34c is formed on one end side of the slide guide 34, and the taper portion 34c is
It is engaged with the tapered hole 33c of the slide die 33. On the other hand, the guide drive plate 3
A recess 34d for engaging 7 is formed, and the guide drive plate 37 engages with one of the slide guides 34. The guide driving plate 37 is
The back side is supported by a back plate 38. As shown in FIG. 5, a pair of guide rails 38a for guiding a sliding operation of the guide driving plate 37 along the back plate 38 are fixed to the back plate 38. ing.

The guide driving plate 37 is driven by a driving means 49 (see FIG. 5) such as a hydraulic cylinder in a direction along the back plate 38 to move along the guide rail 38a and slide. The engagement state 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 rotation 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), when the guide drive plate 37 is driven (moved forward) to the main body 30 side of the movable die 2, the 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 in the initial position when the movable die 2 is closed with respect to the fixed die 1 (see FIG. 1) and does not exert a driving force on the slide die 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 (moved forward) toward the main body 30 of the movable die 2. As a result, the taper hole 33c of the slide die 33 is arranged along the taper portion 34c of the slide guide 34,
The slide die 33 is slid outward, and the core portion 33a thereof is pulled out from the pipe end portion of 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 (two in the example of FIG. 4 on the right side) and ejecting the ejector plates 46a and 46b, 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). When the mold is opened after the molding process is completed (see Fig. 2)
The ejector pin 27a is projected to the inside.

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 plate blocks 20 has a molding part 20A, 20B or 20.
C is provided. The molding part 20C is a male mold part formed in a convex shape, and both the molding parts 20A and 20BC are female mold parts formed in a concave shape. That is, the rotor 13 of the fixed mold 1 includes one male molding portion 20C and two female molding portions 20A and 20B. The two female molding portions 20A, each of 20B, the lower half W _L of the molded product W
The backup pins 13 _K corresponding to the respective engaging portions K _L (pin holes) formed in are respectively arranged at predetermined positions.

Incidentally, there is no resin passage connected to each of the molded portions 20A, 20B, 20C provided in 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 at least an arc length corresponding to an angle of 120 degrees. Along with this (that is, according to the rotation direction and the number of rotations), the rotor 13 is rotated in a predetermined direction by 120 degrees. The control of the rotation of the drive gear 14 (that is, the rotation control of the rotor 13) is
This is performed by controlling the 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.

On the other hand, 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
The 0Cs are provided in a circumferentially equidistant manner (that is, at an angle of 120 degrees to each other). The molding part 40B is a male mold part formed in a convex shape, and the molding parts 40A and 40C are both female mold 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. 1 to 4 are longitudinal sectional explanatory views taken along the line A-C in FIG.
FIG. 5 is a vertical cross-sectional explanatory view taken along the line BB in FIG. 7.

The molding plate 40 of the movable mold 2 includes the molding parts 4
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. Female mold parts 40A, 40C
The secondary for bonding to bond 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 resin are connected. on the other hand,
Only the primary resin passage 41B is connected to the male molding 40B. Each of the primary resin passages 41 (41A, 41)
B, 41C) are the respective molded portions 40 (40A, 40B, 40).
It is connected to the side surface of the portion corresponding to the molded product inlet portion Wi in C). In addition, each secondary resin passage 42 (42A,
42C) are provided as a pair on both sides of each molding portion 40A, 40C, and are connected by providing a gate portion 42g on a side surface of a portion of each molding portion 40A, 40C corresponding to the molded product outlet portion Wo.

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

When the movable die 2 is closed with respect to the fixed die 1, a predetermined resin passage and a branch portion resin passage 43 (that is, a resin passage) are formed by the switching slot 21 provided in the rotor 13 of the fixed die 1. , The spool 12a), and this connection state can be switched by the 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 primary resin is always supplied to the molding portion 40B regardless of the rotation position of the rotor 13.

The forming process of the intake manifold W, which is performed using the forming die having the above-described structure, will be described. First, in the 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 parts of these 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 in the rotational position shown 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, 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 the molding machine (not shown).
The molten resin passes through the spool 12a and the branched resin passage 4
The resin is supplied to each of the resin passages 42A, 41C, 41B communicating with the third resin passage 3. In this example, as the material resin, for example, a nylon resin mixed with glass reinforced fiber was used. As a result, in the molding cavity in which the respective molding parts of the fixed mold 1 and the movable mold 2 are combined, the following molded body is molded. -Molding part 40A (female mold) / molding part 20A (female mold): finished product W-Molding part 40B (male mold) / molding part 20B (female mold): Lower half W _L -Molding part 40C (female mold) / 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 ) do not exist, molten resin is injected after setting a dummy having the same outer shape as the one obtained by abutting the upper half W _U and the lower half W _L. 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 example of FIGS. 1 to 4) is set to engage with the recess 34d.

During this injection step, the molding section 40A of the movable mold 2
Are filled with the secondary resin in the respective secondary resin passages 42A. In the present embodiment, as described above, the half body W
_U and W _L are configured so that, inside the inner passage W _P of the abutting portion, the respective step portions S _U and S _L (see FIGS. 14 to 16) are combined and fitted together. Therefore, when the secondary resin that joins the two halves W _U and W _L is filled in the internal passage W _P , it is possible to regulate the leakage of the molten resin in the passage W _P to the inside. Further, the abutment back side of each half split body W _U, W _L, when the secondary resin into the interior passage W in _P is filled, engaging a backup member for supporting the abutment from the back side Engaging portions K _U , K _L (grooves, pin holes) are provided, and backup members (vertical wall-shaped backup portion 2 _K , backup pin 1) are provided in these engaging portions K _U , K _L.
3 _K ), the back side of the abutting portion can be firmly supported, and the resin pressure acts when the secondary resin is filled in the internal passage W _P. Also, loosening of the abutment portion is reliably prevented.

After the above 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.

Next, by moving the piston rod 39 forward, the slide guide 34 that engages with the slide die 33 for the finished product W is advanced (see FIG. 3).
The core portion 33a of the slide die 33 is pulled out from the exit 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.

Then, by further advancing the slide guide 34, each protruding 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 removed from the entrance 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 (see FIG. 4). ). In this manner, the core members (core member 36a and slide-type core portion 33a) corresponding to the inner peripheral portions of the two pipe ends (the inlet Wi and the outlet Wo) forming the angle of the finished product W do not interfere. The finished product W can be taken out without taking out.

On the other hand, the molding section 40B (male) and the molding section 20
The lower half W _L molded in the cavity formed by B (female mold) is left in the molding part 20B of the fixed mold 1, and is formed by the molding part 40C (female mold) / molding part 20C (male mold). The upper half W _U molded in the cavity is a movable mold 2
Is left in the molding section 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 Since the upper half W _U is left in each of the 40 C, the rotation of the rotor 13 causes the upper half W _U and the lower half W _L to be separated between the molding portion 40 C (female mold) and the molding portion 20 B (female mold). 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
However, each secondary resin passage 4 for 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 the molding machine (not shown).
The molten resin passes through the spool 12a and the branched resin passage 4
3 are supplied to the resin passages 41A, 42C, 41B. As a result, in the molding cavity in which the respective molding parts of the fixed mold 1 and the movable mold 2 are combined, the following molded body is molded. Molding part 40A (female mold) / molding part 20C (male mold): Upper half W _U -Molding part 40B (male mold) / Molding part 20A (female mold): Lower half W _L -Molding part 40C (female mold) / molding Part 20B (female): Finished product W In addition, in the molding part 40B (male) of the movable mold 2, in 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 normal rotation and reversal of the rotor 13 of the fixed mold 1 every 120 degrees, mold clamping, injection and mold opening are performed each time, so that one rotation operation of the rotor 13 is performed. The molded product W can be obtained.

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 first aspect of the present invention, in the above-mentioned half body, inside the inner passage of the above-mentioned abutting portion, the respective stepped portions are combined and fitted to each other. Therefore, when the molten resin for joining the two halves is filled in the internal passage, the leakage of the molten resin in the passage to the inside can be regulated. That is, it is possible to effectively deal with leakage to the inside where inspection is generally difficult. Furthermore,
Since the engaging portion is provided on the rear surface side of the abutting portion of each half body, a backup member that supports the abutting portion from the rear surface is engaged with the engaging portion to melt in the internal passage. Even if the resin pressure is applied when the resin is filled, it is possible to reliably prevent the abutment portion from being loosened. As a result, the joining strength between the half bodies can be ensured, and the reliability of the intake manifold for long-term use can be maintained.

According to the second aspect of the present invention, basically, the same effects as those of the first aspect can be obtained. In particular, since the engaging portion is a groove portion provided along the peripheral edge of the abutting portion, a backup member (for example, a wall-shaped backup member) that engages with the groove portion supports the abutting portion from the back side. Thus, it is possible to reliably prevent the abutment portion from being loosened by the action of the resin pressure in the internal passage. The backup member is preferably continuous along the peripheral edge of the abutting portion.

Further, according to the third invention of the present application, basically, the same effect as that of the first invention can be obtained. In particular, since the engaging portion is a plurality of pin holes provided along the periphery of the abutting portion, by supporting the abutting portion from the back side with a pin-shaped backup member engaging with the groove, It is possible to reliably prevent the abutting portion from being loosened against the action of the resin pressure in the internal passage. In this case, only a plurality of pin holes remain on the back side of the abutting portion of the molded product (intake manifold). The effect on appearance can be slightly stopped. The pin-shaped backup member and the backup member that engages with the groove may be used in combination.

Further, according to the fourth invention of the present application,
Basically, the same effect as any one of the first to third inventions can be obtained. In particular, each of the halves is molded by a mold for rotary injection molding (die rotary injection (DRI)), and the molten resin is filled in the internal passage in the same mold. , When molding a synthetic resin intake manifold by the DRI method, it is possible to reliably prevent looseness at the abutting part against the action of resin pressure in the internal passage, and secure the joint strength between the half halves. can do.

[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 a vertical cross-sectional explanatory view similar to FIG. 1, showing a slide mold 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 a front explanatory view of a movable die of the above-mentioned forming die.

FIG. 8 is a front explanatory 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 a 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 a side view illustrating the molded product.

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

FIG. 14 is a vertical cross-sectional explanatory view of the molded product taken along the line EE in FIG.

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 sectional view for explaining an engaging portion of the molded product.

FIG. 18 is an explanatory longitudinal sectional view corresponding to FIG. 14 of a molded product according to another embodiment of the present invention.

[Explanation of symbols]

1 ... fixed die 2 ... movable die 2 _K ... Tatekabejo backup unit 13 ... rotor 13 _K ... backup pins 20A, 20B, 20C ... formed portion 40A of the fixed mold side, 40B, 40C ... of the movable die side molding part K _L ... Engagement part (pin hole) of lower half body K _U ... Engagement part (groove part) of upper half body K '... Engagement part (pin hole) S _L ... Step part S of lower half body S _U ... stepped portion W of the upper-half body ... intake manifold W _L ... lower half body W _P ... internal passage W _U ... upper-half body

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Akira Shimonishi 2-1-1 Taoyuan, Ikeda City, Osaka Prefecture Daihatsu Industry Co., Ltd. (72) Daibun Okada 2-1-1 Taoyuan, Ikeda City, Osaka Prefecture No. Daihatsu Kogyo Co., Ltd. (72) Nobuyuki Homi, No. 175, Oazahara, Yatsumotomatsucho, Higashihiroshima City, Hiroshima Prefecture (72) Inventor Ryuji Takashina, 175 Ojihara Hachimotomatsucho, Higashihiroshima City, Hiroshima Prefecture No. 1 Daikyo Co., Ltd.

Claims (4)

[Claims] 1. A pair of synthetic resin halves are abutted against each other, and a molten resin is filled in an internal passage formed along a peripheral edge of the abutting portion to thereby form the halves. And the structure of the synthetic resin intake manifold obtained by joining the above, wherein the half-split body is combined with each other by combining the respective step portions inside the internal passage of the abutment portion. On the back side of the abutting portion of each half, an engaging portion is provided for engaging a backup member that supports the abutting portion from the back side when the internal passage is filled with the molten resin. The structure of the intake manifold made of synthetic resin. 2. The structure of an intake manifold made of synthetic resin according to claim 1, wherein said engaging portion is a groove provided along a peripheral edge of the abutting portion. 3. The device according to claim 1, wherein the engaging portion is a plurality of pin holes provided along a peripheral edge of the abutting portion.
Structure of the intake manifold made of synthetic resin described. 4. A molding die in which each of the half-divided bodies is openably and closably combined with each other, and one of the molding dies is rotatable with respect to the other by a predetermined angle. Molded in a rotating injection molding die having at least one male molded part and two female molded parts in a rotating male / female / female repetition order in the rotation direction. The structure of the synthetic resin intake manifold according to any one of claims 1 to 3, wherein the molten resin is filled in the same mold.