JP5679769B2 - Resin intake manifold - Google Patents

Description

  The present invention includes a surge tank to which intake air is supplied from an inlet to which a throttle body is connected, and a plurality of outlet pipes extending from the surge tank to the engine side. Secondary additive gas injection for connecting a secondary additive gas pipe for discharging a secondary additive gas such as EGR gas or blow-by gas to be recirculated to the intake side of the engine for combustion and purging The present invention relates to an intake manifold provided with an inlet.

  Such a gas pipe structure for secondary addition is disclosed as an evaporative fuel pipe structure in Patent Documents 1 and 2 below. The secondary additive gas returned to the intake side has various purposes. However, when the number of cylinders of the engine is plural, it is necessary to distribute each cylinder at the same ratio. This is because if the air-fuel ratio is not made uniform for each cylinder, a loss occurs in engine efficiency, resulting in a reduction in fuel consumption and damage to parts.

  As a method for uniformly distributing these secondary additive gases to the respective cylinders, a method in which these gases are diffused in the intake manifold and uniformly mixed with the intake air is generally used. In particular, a surge tank provided to make the intake air flow uniform is often used as a space for diffusing the secondary additive gas.

  In Patent Document 1, in order to ensure the degree of freedom of arrangement when arranging a purge pipe in a surge tank provided with an outlet pipe for intake air to each cylinder in a line from the side of the cylinder along the axis of the cylinder, A method of brazing and fixing a purge pipe in a surge tank is disclosed.

  On the other hand, Patent Document 2 discloses an intake manifold of a type in which a plurality of outlet pipes extend from the top of a surge tank. In the intake manifold of Patent Document 2, a secondary addition gas introduction pipe for recirculating at least one of evaporative fuel, EGR gas, and blow-by gas is connected to the back wall on the opposite side of the outlet port of the surge tank. At the center of the outlet arrangement area of the outlet pipe. In addition, this gas inlet pipe projects the inlet port of the gas inlet pipe into the space inside the surge tank at the same time that the pipe inlet port of the gas inlet pipe protrudes outside the surge tank. It extends to a position corresponding to the opening edge of the intake port of the surge tank. As a result, the introduced secondary addition gas is quickly diffused in the surge tank so that the discharge amount and air-fuel ratio to each cylinder can be made uniform.

JP-A-11-210573 JP 2006-207469 A

  However, in the configuration of the intake manifold of Patent Document 1, the distance from the evaporated fuel introduction port of the surge tank to the extension port of each outlet pipe of the surge tank is different.

  For this reason, the secondary additive gas introduced from the secondary additive gas inlet on the one side into the surge tank becomes lean according to the distance from the outlet pipe on the side close to the inlet to the outlet pipe on the far side. There is a problem that the distribution efficiency of the secondary additive gas in the cylinder is poor and the air-fuel ratio is different. Moreover, since it brazes in a surge tank, it becomes expensive also in cost. In addition, although patent document 1 is a description about a purge pipe, the same can be said also about the case where EGR gas and blow-by gas are recirculated from a viewpoint of secondary addition gas mixed in intake air.

  Moreover, since the gas pipe for secondary addition described in Patent Document 2 is provided with an opening toward a space near the center of the surge tank, it is preferable from the viewpoint of uniform air-fuel ratio to each cylinder. I can say that. However, since the secondary addition gas pipe is routed from the back side of the surge tank and is connected to the back wall of the surge tank at a right angle, there is a problem that it is bulky. Here, the “back wall” means a wall on the side facing the outlet pipe. Further, the gas introduction pipe protrudes into the surge tank, and the flow of intake air in the surge tank is likely to be disturbed, and the protruding position and the protruding state are limited. Furthermore, when the engine is placed horizontally with respect to the vehicle body (the crankshaft is substantially perpendicular to the vehicle traveling direction), the secondary addition gas pipe may pierce other parts during a vehicle collision. This also leads to a gas leak.

  In view of such a problem, the present invention allows the secondary addition pipe to connect the secondary addition gas pipe from the side of the surge tank, while allowing the secondary addition pipe through the plurality of outlet pipes branched from the surge tank. An object of the present invention is to provide an intake manifold capable of releasing the additive gas more evenly into each cylinder and equalizing the air-fuel ratio.

In order to solve the above-described problems, an intake manifold according to the present invention includes an inlet connected to a throttle body disposed above, a surge tank having an outlet of an outlet pipe to each cylinder at the bottom, and the extension A resin intake manifold that is connected to the surge tank through a port and has an outlet pipe that extends from the bottom of the surge tank and rises up to face the surge tank, along the back wall of the surge tank , have a secondary additive gas inlet which is projected into the surge tank towards the inwardly bulged portion provided inside of the surge tank, the inward bulging portion, the secondary additive gas inlet secondary additive gas inlet port formed in the through-hole from is characterized that you have been opened.

  In such a configuration, since the secondary additive gas inlet projects laterally from the surge tank, the secondary additive gas pipe can be connected from the side of the surge tank. Further, since the protrusion of the secondary additive gas inlet is a protrusion along the back wall of the surge tank, the bulk of the secondary additive gas pipe is reduced. In addition, since there is no protruding portion in the surge tank, the flow of intake air in the surge tank is not disturbed.

  In addition, the surge tank is connected to the throttle body at the top, and the outlet pipe to each cylinder rises from the outlet pipe extension port formed at the bottom of the surge tank so as to face the surge tank. Flows from the bottom to the bottom of the surge tank and then flows upward from the bottom. Therefore, it is possible to secure the position of the secondary additive gas inlet so that the air-fuel ratio to each cylinder can be made uniform on the back wall of the surge tank (the wall on the side opposite to where the outlet pipe rises).

  In the above, the secondary additive gas inlet further has a secondary additive gas inlet at a position corresponding to approximately the center of the outlet arrangement region of each outlet pipe in the surge tank.

  In such a configuration, the secondary additive gas inlet may further be provided with a secondary additive gas inlet at a position corresponding to substantially the center of the extended outlet array region of each outlet pipe on the back wall in the surge tank. it can. As a result, the secondary additive gas can be mixed into the intake air at a position before the intake air branches to the respective output ports and at an approximately equal distance from each output port.

  According to the intake manifold of the present invention, the secondary additive gas inlet and the secondary additive gas pipe connected to the intake manifold can be configured not to be bulky in the peripheral space of the intake manifold.

  At the same time, the secondary additive gas inlet projects sideways along the back wall of the surge tank, so the secondary additive gas inlet in the surge tank opens along the back wall of the surge tank, There is no opening protruding into the space, and the flow of intake air in the surge tank is not disturbed. In addition, since there is no gas introduction port protruding into the surge tank, there is no possibility of being stuck somewhere in the event of a vehicle collision.

  Further, in the configuration of the intake manifold according to the present invention, the intake air flows from above the surge tank to the bottom of the surge tank, and flows branched from the bottom to the top. Therefore, it is possible to secure the position of the secondary additive gas inlet so that the air-fuel ratio to each cylinder can be made uniform on the back wall of the surge tank (the wall on the side opposite to where the outlet pipe rises).

  In particular, if the secondary additive gas inlet is in the back wall of the surge tank and is approximately in the center of the outlet tube extension region, the intake air is just before branching to each output port, and The secondary additive gas can be mixed into the intake air at a position where the distances are substantially equal. As a result, the air-fuel ratio in each cylinder can be made uniform. In addition to the above, if the secondary additive gas inlet is located as close as possible to the throttle body above the surge tank, the secondary additive gas diffuses into the surge tank earlier, so that the air-fuel ratio can be made uniform. With this, more effective effects can be obtained.

  Furthermore, since the intake manifold capable of obtaining the above functions and effects is formed of resin and is formed of only two divided members, it is excellent in mass productivity and greatly contributes to cost reduction.

The perspective view which isolate | separates and shows one example of the intake manifold which concerns on embodiment of this invention into the upper member and the lower member. Sectional drawing of the intake manifold. The transverse cross section of the pipe addition part for secondary addition in the surge tank of the intake manifold.

  A specific example of the intake manifold according to the present embodiment will be described with reference to FIGS. 1 to 3 for the understanding of the present invention. Note that this embodiment is an example of one embodiment of the present invention, and modifications are allowed without departing from the gist of the present invention.

  As shown in FIG. 1, the intake manifold 100 of the present embodiment shown in FIGS. 1 and 2 is composed of a resin member that is divided into an upper member 11 and a lower member 12. 2, a surge tank 2 to which intake air is supplied from an inlet 1 to which a throttle body 20 is connected, and a plurality of outlet pipes 3 extending from the bottom of the surge tank 2 to the engine side. Yes. The space between the bottom of the surge tank 2 and the outlet pipe 3 is referred to as an extension port 3a (or simply “extension port 3a”) of the outlet pipe 3.

  The surge tank 2 is provided with a secondary additive gas inlet 4. The secondary additive gas inlet 4 is provided with a secondary additive gas pipe that distributes at least one of the evaporated fuel, EGR gas, blowby gas, etc. in a fuel tank (not shown) as the secondary additive gas to be refluxed. (Not shown) is connected.

  Intake manifold 100 is formed with an inlet 1 to which throttle body 20 is directly connected. Entrance 1 is also the entrance of surge tank 2. Therefore, the surge tank 2 continues from the entrance 1. The surge tank 2 has a vertically long portion in the vertical direction, and an outlet 3a of an outlet pipe 3 extending to each cylinder is formed at the bottom. At the bottom of the surge tank 2, the portion where the extended ports 3a are arranged is called an extended port arrangement area. In FIG. 1, the extending ports 3a are formed side by side for three cylinders. The extended port arrangement area refers to a region where these three extended ports are arranged. In this specification, the surge tank 2 is called “upper” on the intake upstream side and “lower” on the downstream side, but it is called for convenience and is not limited to upper and lower in the direction of gravity.

  The inlet 1 of the surge tank 2 does not have to have the same width as the extended outlet arrangement region. Therefore, the surge tank 2 has a shape that continuously extends from the inlet 1 through the vertically long portion to the wide extension opening array region. In order to control the flow of intake air, the cross-sectional area of the vertically long portion may change from top to bottom. In FIG. 2, the cross-sectional area of the vertically long portion is narrowed downward from the entrance 1.

  Outlet pipes 3 are formed from the extending ports 3a formed at the bottom of the surge tank 2 toward the cylinders. The outlet pipe 3 rises from the bottom of the surge tank 2 so as to face the surge tank 2. Then, at a position substantially the same as the entrance 1, the connection flange 3 c is bent to the opposite side to the entrance 1 and connected to the engine side. An outlet 3b is opened in the connection flange 3c. That is, the engine is disposed in the rising direction of the outlet pipe 3.

  Thus, the intake manifold 100 of the present invention has a V-shape or U-shape that rises from the bottom of the surge tank 2 so that the outlet pipe 3 faces the surge tank 2, so that the throttle body 20 to the engine In the meantime, the flow path length for shaping the flow of intake air is secured, and the front-rear length is shortened to make it compact.

  Also, between the surge tank 2 and the outlet pipe 3, in order to ensure the strength of the intake manifold 100 as a whole, the longitudinal ribs 32 and the lateral ribs 31 are formed to have a T-shaped cross section.

  The secondary additive gas inlet 4 is formed in the back wall 2 a of the surge tank 2 so as to protrude from the side surface of the intake manifold 100. Here, the back wall 2a of the surge tank 2 refers to the side surface opposite to the rise of the outlet pipe 3 in the surge tank 2. Further, the number of secondary additive gas inlets is not necessarily one, and a plurality of secondary additive gas inlets may be provided. For example, reference numerals 13 and 14 are secondary additive gas inlets. For example, if reference numeral 13 is a brake pipe, reference numeral 14 is a blow-by gas inlet.

  FIG. 3 shows a planar cross section of the secondary additive gas inlet 4. The secondary additive gas inlet 4 is integrated with the back wall 2a of the surge tank 2 at the protruding base 4a. Then, an inwardly bulging portion 2 e is formed inside the surge tank 2. The secondary additive gas inlet 5 is opened in the inwardly bulging portion 2e. Therefore, a through hole is formed from the secondary additive gas inlet 4 to the secondary additive gas inlet 5. In other words, the secondary additive gas inlet 5 is formed along the inner wall surface of the surge tank 2. As will be described later, the inwardly bulging portion 2 e is a portion provided for opening the secondary additive gas inlet 5 at a predetermined position on the inner wall of the surge tank 2.

  Thus, since the intake manifold 100 of the present invention is formed by two resin-molded members, the intake manifold 100 must have a shape that can be molded, and the secondary addition projectingly formed on the side of the surge tank 2 The gas injection port 4 is configured not to form a protruding port inside the surge tank 2.

  At this time, the secondary additive gas introduction port 5 opens on the back wall 2a at a position corresponding to approximately the center of the extended port arrangement area of each outlet pipe 3. Here, “the position of the back wall 2a corresponding to substantially the center of the extended outlet arrangement region of each outlet pipe 3” is the inner surface of the back wall 2a of the surge tank 2 and the extended outlet region. It refers to a position that faces almost the center, and does not mean the center of the back wall 2a. In addition, the secondary additive gas inlet 5 may be said to open at a position corresponding to substantially the center of the outlet arrangement region of each outlet pipe 3 inside the surge tank 2. Furthermore, “substantially the center of the extended port array region” includes a position where the air-fuel ratio of each cylinder becomes uniform.

  Next, the function of the secondary additive gas inlet 4 in the intake manifold 100 of the present invention will be described. Intake air from an air cleaner (not shown) is introduced into the throttle body 20. In the throttle body 20, the throttle valve 20 a rotates according to the opening / closing of the accelerator, and the amount of intake air passing through the throttle body 20 is adjusted. The intake air that has passed through the throttle body 20 is introduced into the surge tank 2.

  The surge tank 2 is a space provided before branching to the outlet pipe 3 to each cylinder, and the intake air is supplied from a buffer space that always keeps the intake air constant to each cylinder having different intake air intake timings. To do. The outlet pipe 3 extending to the surge tank 2 and connected via the outlet 3a is connected to the intake port of each cylinder. The intake air in the surge tank 2 flows through the outlet pipe 3 by the negative pressure in the engine cylinder and is sent to each cylinder. At this time, the intake air is rectified while flowing in the outlet pipe 3.

  On the other hand, for example, the purge gas is sent from the canister, the blow-by gas is sent from the crank chamber, and the EGR gas is sent from the exhaust manifold to the intake manifold 100 by means such as piping or pipes.

  These secondary additive gas pipes are connected to the secondary additive gas inlet 4. At this time, the secondary additive gas inlet 4 is formed on the back wall 2a of the surge tank 2 of the intake manifold 100 so as to protrude in the lateral direction, so that the secondary additive gas pipe is easily connected.

  Further, the piping of the secondary additive gas can be routed along the side surfaces of the intake manifold 100 and the surge tank 2. Therefore, the pipe is not bulky as compared with the case where the pipe approaches the intake manifold 100 or the back wall 2a of the surge tank 2 at a right angle.

  In addition, since the secondary additive gas inlet 4 is formed so as to be inserted into the back wall 2a of the surge tank 2 from the side surface side, in other words, on the side where the outlet pipe 3 to each cylinder is disposed. The degree of freedom of arrangement is higher than when it is provided.

  Further, the secondary additive gas inlet 4 is inserted into the back wall 2a of the surge tank 2 from the side surface side, and the intake manifold 100 of the present invention is formed from two resin molded members of the upper member 11 and the lower member 12. Therefore, an outlet projecting inward is not formed in the surge tank 2. The outlet of the secondary additive gas inlet 4 in the surge tank 2 is a secondary additive gas inlet 5 that opens in a shape along the inner wall of the surge tank 2. Therefore, the flow of intake air in the surge tank 2 is not disturbed.

  The secondary additive gas is introduced into the surge tank 2 from the secondary additive gas inlet 4 through the secondary additive gas inlet 5 in the surge tank 2. Since the secondary additive gas inlet 5 is provided at a position corresponding to approximately the center of the extended outlet arrangement area provided at the bottom of the surge tank 2, the secondary additive gas is mixed with the intake air from above. Thus, it is possible to reach any outlet pipe 3 by movement of almost the same distance. As a result, the air-fuel ratio of each cylinder can be made uniform.

  At this time, the closer the secondary additive gas inlet 5 is to the inlet 1 of the surge tank 2, the earlier the mixing with the intake air is, the more preferable from the viewpoint of making the air-fuel ratio of each cylinder uniform.

  Further, as shown in FIGS. 1 and 2, the intake manifold 100 having such a configuration has a bottom line of the surge tank 2 and an extension port 3a to an outlet 3b of each outlet pipe 3 by a dividing line 6 shown in FIG. By dividing the upper and lower parts into two parts, both the upper member 11 and the lower member 12 divided into two parts can be easily molded. The upper member 11 is more complicated than the lower member 12, but can be molded by a mold that opens to the left and right and a mold that opens up and down as shown by arrows in FIG.

  In such mold forming, the secondary additive gas inlet 4 provided to project to the side of the surge tank 2 is open toward the opening direction of the left and right molds. Molded. The same applies to the secondary additive gas inlets 13 and 14 projecting to the opposite side of the surge tank 2 from the secondary additive gas inlet 4.

  Further, the secondary additive gas inlet 5 that the projecting base 4a of the secondary additive gas inlet 4 opens into the surge tank 2 only needs to be opened at the inner surface of the surge tank 2 formed by a mold that is opened up and down. However, the secondary additive gas inlet 5 formed by the projecting base 4a of the secondary additive gas inlet 4 is, however, in contrast to the back wall 2a having a convex rounded shape as shown in FIG. Since the opening opens in an elliptical shape along the inner surface indicated by the broken line, the opening 3a of each outlet pipe 3 is largely offset from the arrangement area of the outlets 3a.

  Therefore, in the illustrated example, as shown in FIGS. 2 and 3, a step 2 b that runs vertically on the inner surface of the back wall 2 a of the surge tank 2 on the side opposite to the protruding direction of the secondary additive gas inlet 4 is provided. An inwardly bulging portion 2e is formed so as to extend downward from the inner surface of the shoulder portion 2c protruding to the back portion under the entrance 1. The secondary additive gas inlet 5 corresponding to the protruding base 4a of the secondary additive gas inlet 4 is opened below the step 2b that runs vertically.

  As a result, the outlet pipes 3 are arranged at suitable positions in the arrangement direction of the extension ports 3a. In the illustrated example, particularly in the illustrated example, the protrusions of the secondary additive gas injection ports 4 are arranged. When viewed from the side, an opening is provided at a position slightly in front of the center.

  In the illustrated example, the inward bulging portion 2e is provided so as to extend from the shoulder portion 2c to the inner surface of the surge tank back wall 2a to a position where the secondary additive gas inlet 5 is opened, and downward at the end position of the extension. The step 2b running in the left-right direction is formed. With this configuration, the mold can be formed by a mold that opens up and down on the inner surface of the surge tank 2.

  The intake manifold 100 of the present embodiment is not particularly limited in material, but is made of resin in the illustrated example. Specifically, PA6GF30 (polyamide 6 + with 30% glass) is employed. Thereby, required strength and heat resistance can be obtained. However, the intake manifold 100 of the present embodiment rises after the outlet pipe 3 extends forward in front of the bottom of the surge tank 2 and is compact in a manner that faces the surge tank 2 in the immediate vicinity, and is as light as possible. Because of the relationship, there is a surface that is prone to vibration and damage.

  Therefore, as shown in FIG. 1, lateral ribs 31 extending in the lateral direction connecting the entrance 1 and the outlet pipes 3, and extending downward from a substantially horizontal center position of these lateral ribs 31 to the surge tank 2 and each Longitudinal ribs 32 that connect between the central portions of the outlet pipes 3 and the arrangement area are provided and reinforced. Further, the in-mold passages forming the lateral ribs 31 and the longitudinal ribs 32 are formed by injection molding using the lower end side of the back wall 2a of the surge tank 2 as a resin injection port, from the surge tank 2 side to each outlet pipe 3 side. It becomes a resin flow passage that promotes the resin flow to, and the resin flow to the connection flange 3c of the outlet 3b having a large volume is improved.

  At the projecting boundary portion of the secondary additive gas inlet 4 from the outer surface of the surge tank 2, stress due to vibration transmitted from the secondary additive gas pipe connected to the secondary additive gas inlet 4 is concentrated. Easy to break. Corresponding to this, as shown in FIG. 1, an axial rib 34 for dispersing the concentrated stress is integrally formed around the protruding base 4a protruding from the outer surface of the surge tank 2 of the secondary additive gas inlet 4. doing. Such a configuration is preferably performed for the other secondary additive gas inlets 13 and 14 in the same manner. Since the secondary additive gas inlet 4 protrudes along the back wall 2a of the surge tank 2, the ribs 34 are integrally formed along the back wall 2a, and the rib 34 is formed on the front side and the surge tank 2 on the front side. The back side of the secondary additive gas inlet 4 is omitted because it is reinforced by the upper and lower ribs 34 and the back wall 2a.

  In particular, the volume of the connection flange 1a formed at the inlet 1 is radiated in the vicinity of the connection flange 3c of each outlet pipe 3 by relaying the connection flange 1a on the lateral rib 31 by the resin flow to the connection flange 3c having a large volume. It is suitable for promoting the resin flow to the connection flange 3c through the beam-like rib 31a which extends to the both sides. In addition, the resin flow from the surge tank 2 side to the outlet pipe 3 side is such that both the horizontal rib 31 and the vertical rib 32 have no openings or breaks such as windows in the middle from the surge tank 2 side to the outlet pipe 3. Has helped to promote. In addition, reinforcing ribs 33 that connect the outlets 3b of the outlet pipes 3 are formed on the lower member 12 side.

  In the present invention, the secondary additive gas inlet is projected from the surge tank so as to be convenient for connecting the secondary additive gas pipe, and is set so as not to be bulky in the longitudinal direction of the vehicle body. This is practically used to equalize the discharge amount and air-fuel ratio of the next added gas to each cylinder through each outlet pipe.

DESCRIPTION OF SYMBOLS 1 Entrance 2 Surge tank 2a Back wall 2e Inward bulging part 3 Outlet pipe | tube 3a Extending port 3b Outlet 4 Secondary additive gas inlet 4a Projection base 5 Secondary additive gas inlet 20 Throttle body 100 Intake manifold

Claims (2)

An inlet connected to the throttle body disposed above, a surge tank having an outlet for an outlet pipe to each cylinder at the bottom, and connected to the surge tank via the extension, A resin intake manifold having an outlet pipe extending from the bottom and rising up to face the surge tank,
Along said back wall of the surge tank, have a secondary additive gas inlet which is projected into the surge tank towards,
An inward bulge is provided inside the surge tank,
The inward the swollen portion, the secondary additive resin intake manifold secondary additive gas inlet port formed in the through-hole from the gas inlet is characterized that you have been opened.   2. The resin-made product according to claim 1, wherein the secondary additive gas inlet has a secondary additive gas inlet at a position corresponding to substantially the center of the outlet arrangement region of each outlet pipe in the surge tank. Intake manifold.