JP4500638B2 - Surge tank - Google Patents

Description

  The present invention relates to a structure of a surge tank in an automobile gasoline engine or diesel engine.

  A surge tank is attached to the cylinder head of the automobile engine via an intake manifold to supply air into the combustion chamber. As such a surge tank, a tank composed of an upper member and a lower member divided into two parts in the vertical direction has been adopted. In this two-part type surge tank, a branch pipe constituting the intake manifold is formed integrally with the lower member, and an attachment portion for connecting a throttle valve is provided on the side portion of the combined portion of the upper member and the lower member. It is coupled. When this mounting portion is joined to the throttle valve, the throttle valve and the inner space of the surge tank are connected to each other through a cylindrical air passage formed by combining the half cylindrical portions formed in the upper member and the lower member. Will communicate. The upper member and the lower member are fastened together with an open annular gasket interposed between the combined portions, and a throttle valve is connected to the mounting portion via another annular gasket so that the surge tank is hermetically sealed. Assembled.

In the seal structure in the above assembly, a so-called three-surface joining portion is configured so that the open end of the open annular gasket abuts on the circular gasket at a right angle. In the case of such a three-sided sealing structure, the sealing performance of the three-sided matching portion is deteriorated due to the positional deviation between the upper member and the lower member inevitably generated in processing. In order to absorb this displacement, the compression amount of the gasket is increased, liquid packing is applied, or the tolerance accuracy of the knock pin for positioning the upper member and the lower member is increased, and the upper member and After the lower member is fastened and assembled, measures such as cutting the end face of the mounting portion to obtain its flatness have been taken. Patent Document 1 discloses a surge tank that is of a two-divided type and has a seal structure that does not have such a three-surface mating portion.
JP 2000-199460 A

  Thus, although the surge tank in the intake manifold of Patent Document 1 is divided into upper and lower parts, the lower member (lower member) has a cover plate shape, and therefore the attachment portion of the throttle valve is naturally an upper member (upper member). ), And there are restrictions on the site where the mounting portion is formed. In particular, in order to meet the demands for lighter engines, it has been attempted to form a surge tank with a synthetic resin molded body, but it keeps the strength of the surge tank by suppressing the opening deformation of the branch pipe constituting the intake manifold. Therefore, the lower member is preferably made of aluminum. In this case, both the upper member and the lower member need to have a shape that is somewhat deep in terms of strength. However, when the lower member is a lid plate like the surge tank of Patent Document 1, even if the lower member is made of aluminum, there is a difficulty in its strength, and it can meet the requirements for weight reduction required for the engine. It was not a thing.

  The present invention has been made in view of the above circumstances, and is a surge tank that is divided into upper and lower parts and has excellent sealing performance without having a three-surface mating portion, and can be reduced in weight while maintaining strength. It is intended to provide.

The surge tank according to the invention of claim 1 is a surge tank that includes a throttle valve mounting portion, and is assembled by assembling and fastening two upper and lower members made of an upper member and a lower member to each other through a gasket. said one of the two members is formed a throttle valve mounting section through a circular cylindrical communicating portion, the outer peripheral portion of the circular tubular communicating portion constitutes a part of the mating surface of said one member, the other member has a semi-cylindrical recess was formed to cover the outer periphery of the circular cylindrical communicating portion, the inner peripheral surface of the recess constitutes a part of the mating surface of the other member side, wherein The gasket is formed in such a shape that it can be interposed between the mating surfaces , and the portion of the gasket that is interposed between the cylindrical communication portion and the recess is a concave half of the outer peripheral surface of the outer peripheral portion. It is an arcuate arch portion And said that you are.

In the present invention, as in the invention of claim 2, wherein a is lower members one member, when the other member is the upper member, or as in the invention of claim 3, wherein the one member is the upper member When the other member is a lower member, any of them may be used.

According to the surge tank according to the invention of claim 1, the outer peripheral portion of said circular tubular communicating portion constitutes a part of the mating surface of said one member, the other members of the circular tubular communicating portion Since there is a recess formed to cover the outer periphery, and the inner peripheral surface of the recess constitutes a part of the mating surface on the other member side, both the upper member and the lower member have a certain depth. Due to such shape characteristics, even if the upper member is made of synthetic resin and the lower member is made of aluminum, the required strength as a surge tank can be obtained, which contributes to the weight reduction of the engine. Further, since the gasket is formed in such a shape that it can be interposed between the two mating surfaces as described above, the gasket itself can be a closed ring, and the three-surface mating portion as in the prior art can be used. Therefore, it is possible to ensure a good sealing performance without taking measures for absorbing the positional deviation in processing of the upper member and the lower member.

  The best mode for carrying out the present invention will be described below with reference to the drawings. 1 is a schematic partially cutaway front view of an engine in which the surge tank of the present invention is employed, FIG. 2 is an arrow view in the X direction in FIG. 1, and FIG. 3 is a perspective view of a gasket employed in the surge tank of the present invention. 4 is a view similar to FIG. 2 of a modification of the embodiment, and FIG. 5 is a view similar to FIG. 2 of another embodiment.

FIG. 1 shows an eight-cylinder automobile engine, 1 is a cylinder block, 2 is a cylinder head, 3 is an intake manifold, and 4 is connected so as to conjugate eight branch pipes 31 constituting the intake manifold 3. Surge tank. The surge tank 4 is composed of an upper member 5 and a lower member 6 which are divided into upper and lower parts, and both the members 5 and 6 have a certain depth and have substantially the same internal volume. An internal space 56 for storing the water is formed. Eight branch pipes 31 are connected to the lower member 6 so as to communicate with the inner space 56 in a state of four in two rows. Flange 5a, 6a is formed in the opening side peripheral part of upper member 5 and lower member 6, and the mutually opposing surface of both flanges 5a, 6a constitutes one part of the mating surface of upper member 5 and lower member 6.

A throttle valve mounting portion 8 for attaching the throttle valve 7 is formed at one end portion of the surge tank 4. In this embodiment, the throttle valve mounting portion 8 is coupled to one end portion of the lower member 6. A cylindrical communication part (cylindrical communication part) 61 is formed in a bowl shape at the opening end. And the upper half part of this cylindrical communication part 61 protrudes from the mating surface by the said flange 6a, and is set as the semi-cylindrical protrusion part 61a. On the other hand, the upper member 5 includes a semi-cylindrical recess 51 formed at one end so as to receive the protruding portion 61a. The inner surface of the recess 51 and the outer peripheral surface of the protruding portion 61a constitute a mating surface of the upper member 5 and the lower member 6 together with the opposing surfaces of the flanges 5a and 6a.

FIG. 3 shows a gasket 9 interposed on the mating surface in the surge tank 4 having the above-described structure, and the gasket 9 in the figure shows an example of a molded body made of a rubber material. Also good. The gasket 9 is formed in a substantially rectangular closed ring shape so as to follow the shape of the mating surfaces of the upper member 5 and the lower member 6, and has an upward concave shape with one of its ends substantially the same curvature as the outer peripheral surface of the protruding portion 61 a. A semicircular arc arch portion 9a is formed. A groove that can receive the gasket 9 having such a shape is formed on the mating surface of the upper member 5 and the lower member 6 (reference numeral omitted).

When assembling the surge tank 4 having the above configuration, the gasket 9 is half-loaded into the groove formed on the mating surface of the lower member 6, and the groove formed on the mating surface of the upper member 5 is inserted into the upper half of the gasket 9. So that the upper member 5 is put on the upper member 5 and the flanges 5a and 6a are fastened together by bolts and nuts (not shown). Thus, the gasket 9 including the arch portion 9a is interposed on the mating surface including the peripheral surfaces of the protruding portion 61a and the concave portion 51, and the airtightness of the inner space 56 of the surge tank 4 is maintained. The throttle valve 7 is attached to the throttle valve attachment portion 8 via another annular gasket (not shown). Therefore, the annular gasket and the gasket 9 do not constitute a three-surface mating portion, and even if there is a slight positional shift in processing of the upper member 5 and the lower member 6, the sealing performance is not deteriorated. Such a cumbersome treatment such as cutting is unnecessary. Further, the upper member 5 and the lower member 6 can be manufactured by integral molding of the co-synthetic resin, and the surge tank 4 can be supplied at a low cost and at a low cost.

  FIG. 4 shows a modification of the first embodiment. In the case of the engine as shown in FIG. 1, during the operation, a large stress is applied to the left and right branch pipes 31 of the intake manifold 3, and a force to open both branch pipes 31 acts. Thus, both the upper member 5 and the lower member 6 in the first embodiment can be made of a synthetic resin molded body, but the strength is insufficient when the lower member 6 is made of a synthetic resin. Therefore, at least the lower member 6 is preferably made of lightweight aluminum. However, since it is impossible to manufacture the lower member 6 provided with the cylindrical communication portion 61 and the throttle valve mounting portion 8 by integral molding of aluminum, in the example of FIG. 4, the protruding portion 61 a of the cylindrical communication portion 61. The upper half 8a of the throttle valve mounting portion 8 is a separate member 10 formed by integrally molding aluminum.

  Thus, a portion on the mating surface of the separate member 10 and the lower member 6 is provided with a liquid packing (FIPG) interposed between the separate members at a predetermined position, and the gasket 9 similar to the above is attached. If the upper member 5 is joined and fastened to the lower member 6 so as to cover the separate member 10, the surge tank 4 shown in FIG. 4 is obtained. Even if the upper member 5 is made of a synthetic resin, there is no problem in strength. Thus, a combination with such an aluminum lower member 6 maintains a strength and a lightweight surge tank is obtained. Contributes to Since the other configuration is the same as that of the first embodiment, the same reference numerals are given to the common parts, and the description thereof is omitted.

In the example of FIG. 5, the throttle valve mounting portion 8 is integrally connected to the upper member 5 via a cylindrical communication portion 52 similar to the cylindrical communication portion 61, and the mating surface of the cylindrical communication portion 52 by the flange 5 a is formed. The part protruding further downward is a semi-cylindrical protrusion 52a similar to the protrusion 61a. On the other hand, the portion corresponding to the protrusion 52a of the lower member 6, the concave portion 62 similar to the recess 51 is formed. The gasket 9 is equivalent to the upside-down gasket 9 shown in FIG. 3. Accordingly, the surge tank 4 is assembled by interposing and fastening the upper member 5 and the lower member 6 with the gasket 9 interposed between the mating surfaces. be able to. In this case, since the cylindrical member 61 and the throttle valve mounting portion 8 do not exist in the lower member 6, the lower member 6 can be manufactured by integrally molding aluminum, and a lightweight surge tank that maintains strength. This contributes to reducing the weight of automobile engines with fewer parts. Since other configurations are the same as described above, common portions are denoted by the same reference numerals and description thereof is omitted.

It is a schematic partial notch front view of the engine by which the surge tank of this invention was employ | adopted. It is an X direction arrow figure in FIG. It is a perspective view of the gasket employ | adopted as the surge tank of this invention. It is a figure similar to FIG. 2 of the modification. It is a figure similar to FIG. 2 of another Example.

Explanation of symbols

4 Surge tank 5 Upper member 51 Recess 52 Cylindrical communication part (tubular communication part)
52a Protruding part 6 Lower member 61 Cylindrical communication part (tubular communication part)
61a Protrusion
62 recess 9 gasket

Claims (3)

A surge tank comprising a throttle valve mounting portion and assembled by combining and fastening upper and lower two members made of an upper member and a lower member via a gasket on a mating surface of each other,
Said one of the two members is formed a throttle valve mounting section through a circular cylindrical communicating portion, the outer peripheral portion of the circular tubular communicating portion constitutes a part of the mating surface of said one member, the other member has a semi-cylindrical recess was formed to cover the outer periphery of the circular cylindrical communicating portion, the inner peripheral surface of the recess constitutes a part of the mating surface of the other member side, wherein The gasket is formed in such a shape that it can be interposed between the mating surfaces , and the portion of the gasket that is interposed between the cylindrical communication portion and the recess is a concave half of the outer peripheral surface of the outer peripheral portion. A surge tank characterized by an arcuate arch . In the surge tank according to claim 1 ,
The surge tank, wherein the one member is a lower member and the other member is an upper member. In the surge tank according to claim 1 ,
The surge tank, wherein the one member is an upper member and the other member is a lower member.

Images