JP4341635B2 - Molding method of intake flow control valve unit - Google Patents

Description

  The present invention relates to a method for forming an intake air flow control valve unit for controlling an air flow (tumble flow) formed in an intake pipe of an engine and formed in a combustion chamber.

  In recent years, as shown in Patent Documents 1 to 4, an intake air flow control valve device for improving combustion by controlling a tumble flow has been proposed and put into practical use in some engines. FIG. 8 shows a cross-sectional view of an engine 90 equipped with an intake flow control valve (butterfly) 22. 91 is a piston, 92 is an intake valve, 12 is an intake manifold (intake pipe), 94 is a combustion chamber, and 95 is a fuel injection valve. T indicates a tumble flow.

JP 2003-293775 A German Patent Publication DE 19504256A1 JP-T-2002-543324 Japanese Patent Laid-Open No. 5-141540

  FIG. 9 shows an example of a conventional intake flow control valve device for a four-cylinder engine. This is also described in the specification of Japanese Patent Application No. 2005-228278, and has a very simple structure. The intake flow control valve device 10 includes an intake manifold 12, a valve unit 20, and a valve shaft 14. The intake manifold 12 is made of resin, and four intake passages 23 are formed by partition walls 12b. The valve shaft 14 is made of metal.

  The valve unit 20 includes a housing 21 and a butterfly (intake flow control valve) 22 as a valve member. The resin butterfly 22 can rotate together with the valve shaft 14 inside the housing 21, and opens and closes the intake passage 23. FIG. 7 shows a sectional view of a conventional intake flow control valve. As shown in FIG. 7, the butterfly 22 has a boss portion (rotation center portion) 24 having a hole 25 having a rectangular cross section through which the valve shaft 14 passes. The boss 24 is rotatably supported by a support hole 26 (see FIG. 6) of the housing 21 via a bearing 29. In this specification, “rectangle” includes a square.

  As shown in FIG. 9, the valve shaft 14 has a rectangular cross section, and all the partition wall through holes 12a of the intake manifold 12 and the rectangular holes 25 of the boss portions 24 of all butterflies 22 are slidable. It has penetrated. Thereby, the butterfly 22 rotates synchronously with the rotation of the valve shaft 14.

  Further, there is a slight gap between the rectangular cross section of the valve shaft 14 and the rectangular hole 25 of the boss portion 24 of the butterfly 22. The presence of this gap and the fact that the butterfly 22 is made of resin make it possible for the metal valve shaft 14 to slide smoothly relative to the butterfly 22. Incidentally, the resin is flexible and has the property of not easily damaging the metal even if it interferes with the metal on the other side.

  This sliding is necessary for the following reason. That is, since the intake manifold 12 is made of resin and the valve shaft 14 is made of metal to ensure strength, the linear expansion coefficients are different. For this reason, a difference in linear expansion between the two occurs at a high temperature or a low temperature. At this time, when the metal valve shaft 14 is fixed to the butterfly 22 (when it is not slidable), the side surface of the butterfly 22 interferes with the side wall of the housing 21 so that both are damaged. Will occur. In order to prevent this “galling”, the metal valve shaft 14 is required to slide smoothly with respect to the butterfly 22.

  On the other hand, the butterfly 22 may be subject to pressure fluctuations due to intake pulsation or backfire. At this time, if the butterfly 22 is made of resin, there is a possibility that the butterfly 22 is damaged due to insufficient strength. For this reason, in the United States, it is planned that the law will require that the butterfly valve be designed so that it does not break, or that the breakage be detected even if it is broken.

  As a countermeasure, it can be considered that the butterfly 22 is made of a metal such as aluminum having a sufficient strength. However, even if the butterfly 22 is made of metal, the counterpart valve shaft 14 is made of metal, so that the rectangular hole at the center of rotation of the valve shaft 14 has a rectangular cross section, particularly when subjected to pressure fluctuations. There is a risk of interference (rubbing) with the outer peripheral surface and hindering the sliding of the valve shaft 14. In addition, this “rubbing” between metals may damage each outer surface.

  On the other hand, as a conventional problem, the gap between the side walls of the partition wall of the housing 21 and the butterfly 22 (hereinafter referred to as “seal gap”) must be minimized to seal the intake air flow. Due to manufacturing variations, there was a limit to reducing this gap. Further, since the hole 25 of the boss portion 24 is rectangular, it is difficult to ensure the coaxiality between the bearing 29 fixed to the housing 21 and the slidable portion hole 25, and the above manufacturing variation promotes this problem. . Due to the poor coaxiality due to the manufacturing variation, problems such as an uneven load applied to the bearing 29, easy wear, and increased butterfly turning resistance have been induced.

  The present invention has been made in view of the above problems, and its object is to form a highly reliable seal gap as small as possible with respect to pressure fluctuations in the intake pipe as well as at high and low temperatures. An object of the present invention is to provide a method of molding an intake flow control valve unit that is possible and can ensure the coaxiality of the housing-side bearing and the sliding portion hole.

The present invention provides, as means for solving the above problems, a method for molding an intake air flow control valve unit according to each of the claims.
According to the first aspect of the present invention, there is provided a method of molding an intake air flow control valve unit, wherein a metal intake air flow control valve is disposed as an insert in a mold, and the housing surrounding the intake air flow control valve; A resin member that is fixed to the center of rotation of the intake flow control valve and has a polygonal hole is simultaneously resin-molded using a set of molds.

  As a result, since the resin sliding member is interposed, the metal valve shaft which is also a sliding member does not slide directly in contact with the hole of the metal intake flow control valve. . That is, the metal valve shaft slides in contact with the resin sliding member. Resin is flexible and has the property of not easily damaging the metal even if it interferes with the metal on the other side, so that it does not cause “galling” on the metal valve shaft.

  Furthermore, the intake flow control valve is arranged as an insert in the mold, and is molded together with the housing in a set of molds, thereby improving the accuracy of the seal gap between the intake flow control valve and the housing. be able to. And the coaxiality of a housing side bearing and a sliding part hole is securable. In other words, since two parts molded simultaneously in one set of molds are used as a set, the seal gap formed in relation to the two parts and the product variation of the coaxiality are suppressed. That is, it becomes possible to form individual seal gaps as small as possible.

  According to the second aspect of the present invention, the method for molding the intake air flow control valve unit uses an independent mold that defines the length of the resin member. By a simple method, the length of the resin member can be defined, and the sliding resistance of the valve shaft described later can be set to an appropriate value.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The apparatus 50 including the intake flow control valve unit manufactured by the method according to the present invention is installed on the inlet side of the combustion chamber of the engine. As a result, air that has passed through an air cleaner and a surge tank (not shown) flows into the combustion chamber of the engine via the intake flow control valve device 50. The intake flow control valve device 50 controls the flow direction of the intake air flowing into the combustion chamber, that is, the direction of the tumble flow T.

  4 and 5 show an intake flow control valve device manufactured by the method according to the present invention. A device 50 including an intake air flow control valve unit according to the present invention includes an intake manifold 12, a valve unit 60, and a valve shaft 64 as shown in FIG. The intake manifold 12 is made of resin, and forms four storage chambers 16 as shown in FIG. In this case, the valve device 50 is applied to a four-cylinder engine. Therefore, the intake manifold 12 has four accommodating chambers 16 corresponding to the four intake passages 23 in an aligned manner. The storage chamber 16 of the intake manifold 12 constitutes a part of the intake passage 23 that connects the surge tank and the combustion chamber of the engine. The valve shaft 64 is made of metal.

  As shown in FIG. 5, the valve unit 60 is housed in each housing chamber 16 of the intake manifold 12. As shown in FIG. 6, the valve unit 60 includes a resin housing 61, a butterfly 62 as a valve member, and a metal thin bearing 29. The metal bearing 29 is fixed to the housing 61. The housing 61 is formed in a frame shape, and the intake passage 23 is formed inside. And the storage chamber 16 of the intake manifold 12 is a substantially rectangular parallelepiped. Therefore, the housing 61 is formed in a substantially rectangular parallelepiped where the passage 23 corresponds to the storage chamber 16. That is, the housing 61 is formed in a square frame shape having a substantially rectangular cross section. In the passage 23 formed by the housing 61, intake air flowing from the surge tank into the combustion chamber of the engine flows. Therefore, the passage 23 constitutes an intake passage. The housing 61 is formed slightly smaller than the storage chamber 16 of the intake manifold 12.

  A butterfly 62 is disposed inside the housing 61. The butterfly 62 can rotate with the valve shaft 64 inside the housing 61. The butterfly 62 opens and closes the passage 23 formed by the housing 61 by rotating together with the valve shaft 64. As will be described later, the butterfly 62 has a sliding member having a hole having a rectangular cross section through which the valve shaft 64 passes. The valve shaft 14 has a rectangular cross section, and slidably passes through all the partition wall through holes 12 a of the intake manifold 12 and the rectangular holes 25 of the boss portions 24 of all the butterflies 22. Thus, the valve shaft 14 connects the plurality of valves in an aligned manner, and the butterfly 62 rotates in synchronization with the rotation of the valve shaft 14.

  FIG. 5 shows a method for assembling the intake manifold 12, the valve unit 60, and the valve shaft 64. First, each valve unit 60 is assembled in the four accommodating chambers 16 of the intake manifold 12. Thereafter, the valve shaft 64 is inserted from the partition wall through hole 12 a located on the outermost side of the intake manifold 12. Thereby, all the butterflies 62 are aligned and connected.

FIG. 1 shows an intake flow control valve (butterfly) manufactured by the method according to the present invention. FIG. 1A is a front view of the intake flow control valve, and FIG. 1B is a side view thereof.
The butterfly 62 has a highly rigid structure including a plurality of ribs 62c, and is made of aluminum. This is to prevent intake pressure fluctuations and damage due to backfire. And the butterfly 62 has the boss | hub part (rotation center part) 62a. The boss part 62a has a through hole 62b having a substantially rectangular cross section. A resin member 63 is integrally formed with the butterfly 62 in the substantially rectangular hole 62b. The resin used for the resin member 63 is, for example, nylon. The resin member 63 includes a sliding portion 263a and a bearing portion 263b. The sliding portion 263a has a rectangular frame shape including a rectangular hole 63a smaller than the substantially rectangular hole 62b. A valve shaft 64 is inserted through the rectangular hole 63a. And the cross section of the valve shaft 64 is also substantially rectangular.

  In addition, bearing portions 263b are integrally formed at both ends of the boss portion 62a. The butterfly 62 is rotatably supported by the metal bearing 29 fixed to the support hole 26 (see FIG. 6) of the housing 21 through the bearing portion 263b. The reason why the metal bearing 29 is disposed in the housing 21 is that metal is excellent in terms of wear resistance and strength. It is also conceivable to eliminate the bearing portion 263b fixed to the butterfly 62 and directly support the end portion of the metal boss portion 62a with respect to the metal bearing 29. However, contact rotation between metals is not preferable because there is a risk of “galling”.

  As shown in FIGS. 4 and 5, the valve shaft 64 penetrates all the partition wall through holes 12 a of the intake manifold 12, and at the same time, the sliding portion 263 a integrally formed with the boss portions 62 a of all the butterflies 62. The rectangular cross-sectional hole 63a is penetrated. Thereby, the butterfly 62 of each valve unit 60 rotates synchronously with the rotation of the valve shaft 64.

  Further, there is a slight gap S between the rectangular cross section of the valve shaft 64 and the rectangular hole 63a of the sliding portion 263a. The presence of this gap and the fact that the sliding portion 263a is made of resin makes it possible for the metallic valve shaft 64 to slide smoothly with respect to the butterfly 62. Incidentally, the resin is flexible and has the property of not easily damaging the metal even if it interferes with the metal on the other side.

  On the other hand, the sliding resistance R of the valve shaft 64 with respect to the butterfly 62 may not be too large or too small. If the sliding resistance R is too large, as described above, “galling” between the housing 61 and the butterfly 62 occurs due to a difference in thermal expansion due to a difference in material between the intake manifold 12 and the valve shaft 64 at a high temperature or a low temperature. If the sliding resistance R is too small, the valve shaft 64 vibrates in the axial direction due to the vibration of the engine and damages the inner surface of the rectangular hole of the sliding portion 263a of the butterfly 62, or the thrust bearing ( (Not shown).

  That is, the sliding resistance R needs to be set in an appropriate range. This can be achieved by appropriately selecting the gap S and the length L of the sliding member 63.

  In the intake flow control valve manufactured by the method according to the present invention, the conventional resin sliding member and the resin bearing member are integrated into a member 263. That is, the sliding member function part of the member 263 is 263a, and the bearing member function part is 263b. Since the two members are one, the cost can be reduced. That is, the butterfly 62 is resin-molded as an insert, and the butterfly 62 and the member 63 are integrated (integral molding). Furthermore, it is preferable that the member 63 includes a retaining function part 263c of the member 63 from the butterfly 62.

  Next, the molding method according to the present invention will be described with reference to FIGS. FIG. 2 shows a mold for an intake flow control valve unit according to the present invention, and shows a YY section in FIG. FIG. 3 shows a ZZ cross section of the intake flow control valve unit mold of FIG.

  A, B, C, and D are split molds considering mold splitting. A and B are mother molds, and C and D are small molds independent of the mother mold. k1 and k2 are cavities (cavities) into which the molten resin flows. Specifically, k1 is a cavity in which the housing 61 is molded, and k2 is a cavity in which the integrated sliding portion 263a and bearing portion 263b (hereinafter referred to as “resin member 63”) are molded. . k9 is a gate port into which the housing resin flows. The integrated resin gate 63 for the resin member 63 is not shown here. 62 is a metal butterfly as an insert.

  The housing 61 and the resin member 63 may be made of the same thermoplastic resin or different resins. In order to insert and combine the mold C, an opening 62d (see FIG. 1) is clear immediately below the boss 62a of the butterfly 62. Moreover, D1 part is a space for assembling the metal thin bearing 29 after molding.

  And the molding method of this subject is demonstrated from this. First, the molds A, B, C, and D are matched using the metal butterfly 62 as an insert. Next, the molten thermoplastic resin flows into the mold from the gate openings k8 and k9. Incidentally, the resin temperature at this time is 150-180 degreeC. The resin that has flowed into the mold is filled in the cavities k1 and k2 and solidified by being cooled to become the housing 61 and the resin member 63, respectively.

  When the resin is solidified, the molds A, B, C, and D are disassembled, and the butterfly 62 with the housing 61 and the resin member 63 attached thereto is taken out. In the butterfly 62, the resin member 63 is fixed by installing a retaining portion 263c (see FIG. 1).

  By making the mold C independent of the mother molds A and B, it becomes easy to manufacture various molds C having different lengths Lx. By changing the length Lx, the length L of the sliding member 63 can be appropriately selected. In addition, the sliding resistance R of the valve shaft 64 can be appropriately selected.

  As described above, since the resin sliding member is interposed, the metal valve shaft, which is also a sliding member, slides in direct contact with the hole of the metal intake flow control valve. There is no. That is, the metal valve shaft slides in contact with the resin sliding member. Resin is flexible and has the property of not easily damaging the metal even if it interferes with the metal on the other side, so that it does not cause “galling” on the metal valve shaft.

  Furthermore, the intake flow control valve is arranged as an insert in the mold, and is molded together with the housing in a set of molds, thereby improving the accuracy of the seal gap between the intake flow control valve and the housing. be able to. And the coaxiality of a housing side bearing and a sliding part hole is securable. In other words, since two parts molded simultaneously in one set of molds are used as a set, the seal gap formed in relation to the two parts and the product variation of the coaxiality are suppressed. That is, it becomes possible to form individual seal gaps as small as possible.

  Since the molding method according to the present invention is characterized by using an independent mold that defines the length of the resin member, the length of the resin member can be defined by a simple method. The sliding resistance of the valve shaft can be set to an appropriate value.

  Further, in this specification, the intake flow control valve is discussed, but the configuration according to the present invention can of course be used for an engine throttle valve. Further, a modified example in which “polygon” is used instead of “rectangular” is within the scope of the idea of the present invention.

1 is an intake flow control valve manufactured by a method according to the present invention. It is a figure explaining the method which concerns on this invention. It is a figure explaining the method which concerns on this invention. 1 is an intake flow control valve device manufactured by a method according to the present invention. 1 is an intake flow control valve device manufactured by a method according to the present invention. 1 is an intake flow control valve unit manufactured by a method according to the present invention. It is sectional drawing of the intake flow control valve manufactured by the conventional method. It is sectional drawing of the engine provided with the intake flow control valve manufactured by the conventional method. This is an intake flow control valve device manufactured by a conventional method.

Explanation of symbols

10 Intake Flow Control Valve Device of Conventional Example 50 Intake Flow Control Valve Device According to the Present Invention

Claims (2)

A metal intake flow control valve (62) is placed as an insert in the mold (A, B),
A housing (61) surrounding the intake flow control valve;
Resin molding (63) fixed to the rotation center (62a) of the intake flow control valve and having a polygonal hole (63a) is simultaneously molded using a set of molds. A method of molding the intake air flow control valve unit (60), which is characterized.   The method for molding an intake air flow control valve unit (60) according to claim 1, wherein an independent mold that defines the length (L) of the resin member is used.

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