JP6329783B2 - Intake manifold with EGR gas distribution function - Google Patents

Description

  The present invention relates to an intake manifold having an EGR gas distribution function.

  EGR devices that return a part of exhaust gas (EGR gas) to the intake system for exhaust gas purification or the like are widely used in internal combustion engines for vehicles. As a means for distributing the EGR gas to each branch pipe of the intake manifold, Patent Document 1 discloses that the EGR passage is integrated with the branch pipe of the intake manifold in a posture crossing the branch pipe in the cast intake manifold. It is disclosed that EGR gas is supplied to each branch pipe from the EGR passage and the communication hole opened to the branch pipe.

  Patent Document 2 discloses that the EGR passage is manufactured separately from the intake manifold and is fixed to a group of branch pipes. The EGR passage has a single pipe-like structure, whether it is provided integrally with the intake manifold or manufactured separately and fixed.

  Furthermore, the intake manifold is also formed as a resin molded product. In this case, the EGR gas distribution unit is provided on a spacer plate disposed between the intake manifold and the cylinder head (for example, Patent Document 3). .

Japanese microfigures in Japanese Utility Model Sho 63-177653 Japanese micro-fimu of 03-1561 JP 2010-255485 A

Providing the EGR passage integrally with the intake manifold has the advantage of eliminating problems such as loosening due to vibration, the advantage of reducing the labor of assembly, and the advantage of ensuring sealing performance. Since the cast product is manufactured using a sand mold, there is a problem that not only mass production is bad and manufacturing takes much labor, but also the weight tends to increase.

  This problem can be improved by making the intake manifold a resin molded product or a light metal die-cast product. However, in the case of a resin molded product or die-cast product using a mold, there are restrictions on the shape from the point of die cutting, and it is difficult to mold with the EGR passage made hollow (when the passage is bent) Is impossible to manufacture.)

In this regard, it can be said that the EGR passage is constituted by an EGR gas distribution portion integrated with the intake manifold and a cover plate covering the EGR gas passage, and a groove type EGR passage is formed on the mating surface of both. In this case, it is conceivable to form the EGR passage in a simple straight line as in Patent Document 1, and to provide an outlet hole to the branch pipe in the middle of the EGR passage. There is a possibility that the supply of EGR gas to the branch pipe may be incomplete. That is, there is a possibility that variations in the supply amount (ejection amount) of the EGR gas from the plurality of outlet holes may occur, resulting in variations in the combustion of each cylinder.

  The present invention is based on such knowledge, and it is easy to set the advantage of equalizing the amount of EGR gas supplied to a plurality of branch pipes and the amount of EGR gas supplied to each branch pipe. It is intended to provide an improved intake manifold, including the advantage of leveling.

In the present invention , on the outer surface of a group of a plurality of branch pipes arranged in parallel, a horizontally long EGR gas distribution portion extending so as to cross the branch pipe group is integrally provided, and a lid plate is welded to the EGR gas distribution section. An EGR passage is provided on the mating surface of the gas distribution part and the cover plate, and the EGR passage is connected to a main EGR passage having an EGR gas inflow hole and a communication passage branched from the main EGR passage. The branch EGR passage extends substantially parallel to the main EGR passage.

Further, an auxiliary passage having a narrow groove width through which EGR gas can pass is formed on the mating surface of the partition that separates the main EGR passage and the branch EGR passage.

In the present invention, the EGR passage may be formed by forming a groove in only one of the EGR gas distribution part and the cover plate, or may be formed by a groove provided in both. There is no limitation on the cross-sectional shape of the passage, and a circular shape or a square shape can be adopted . Auxiliary passage also, it may be constituted by reducing the thickness of one only of the partition portion of the partition portion and the cover plate of the EGR gas distribution portion, constituted by thinning the both thickness Also good.

  In the present invention, since the EGR passage is composed of an EGR gas distribution portion integrally formed on a member including the branch pipe and a cover plate covering the EGR gas distribution section, the member including the branch pipe is a mold that is in close contact with and separated from the mold. It can be easily manufactured by an injection molding method using (molded shape) or die casting. Therefore, although the intake manifold is integrally provided with an EGR passage, a resin molded product or a die-cast product can be easily adopted, which can contribute to cost reduction and weight reduction.

  In the present invention, the EGR passage is composed of a main EGR passage and a branch EGR passage substantially parallel to the main EGR passage, and an outlet hole is provided at an end of the branch EGR passage, and EGR gas is supplied from the outlet hole to the branch pipe. EGR gas is also supplied to each outlet hole in order because the intake air is supplied to each cylinder in turn, but the outlet hole is located at the end of the branch EGR passage or the main EGR passage. Since the EGR gas goes straight to the outlet hole when it is provided, the outlet holes are provided at the ends of the branch EGR passage and the main EGR passage, so that the EGR gas is substantially evenly distributed from each outlet hole. Can be ejected.

  That is, it is possible to prevent the EGR gas from passing through the outlet holes and to eject the EGR gas from each outlet hole evenly. Therefore, the supply amount of EGR gas to each cylinder can be equalized as much as possible to contribute to stabilization of combustion in each cylinder.

  When the branch EGR passage is provided, the EGR gas distribution portion and the cover plate are widened at the portion where the branch EGR passage is provided. Therefore, the intake manifold is made of resin and the lid is welded to the EGR gas distribution portion by vibration or the like. In this case, the sealing area can be increased by increasing the welding area. In this case, if the lid plate is wide only at the portion where the branch EGR passage is provided, there is an advantage that the amount of resin used can be suppressed and the weight can be reduced and the size can be reduced.

  Now, EGR gas enters the branch EGR passage from the main EGR passage through the communication passage, but in order to further equalize the amount of EGR gas ejected from each outlet hole, the amount entering the branch EGR passage through the communication passage Therefore, it can be said that this point can be realized by setting the size of the opening area of the communication path. However, since the communication passage is connected to the main EGR passage in a state of a horizontal hole, there is a possibility that the flow amount of EGR gas greatly changes due to a slight change in dimensions, and therefore it is difficult to set the dimensions of the communication passage. There is a risk.

About this point, in the present invention, since the small spacing of the gap, the amount of EGR gas through the unit length is small and stable, the amount of EGR gas passing through the gap, the vertical groove of the gap By changing the width and length (the length in the longitudinal direction of the main passage and the branch EGR passage), fine adjustment can be made accurately. That is, even if the length of the gap is changed to some extent, the passing amount of the EGR gas does not change excessively, and the passing amount of the EGR gas can be appropriately changed according to the changing amount of the length or the like. Accordingly, it is possible to easily realize the setting of the amount of EGR gas flowing in the branch EGR passage so that the EGR gas is ejected from each outlet hole.

It is a figure which shows the intake manifold which concerns on embodiment, (A) is the perspective view seen from the cylinder head side, (B) is the perspective view seen from the cylinder head opposite side. (A) is a front view, (B) is a rear view. (A) is a left side view, (B) is a side view. It is the left view which the main-body part isolate | separated. It is a separation perspective view of an upper part and a lid plate. It is the whole top view. (A) is a principal part top view in the state which carried out the cover plate, (B) is a principal part top view in the state which removed the cover plate. (A) is a cross-sectional view taken along the line VIII-VIII in FIG. 7 (B) in a state where a cover plate is applied, and (B) is a partial cross-sectional view showing a molding means for the upper part. It is IX-IX sectional view taken on the line of FIG. 7 (B). FIG. 8 is a cross-sectional view taken along the line XX in FIG. FIG. 7A is a cross-sectional view taken along the line XI-XI in FIG. 7B, and FIG.

(1). Basic structure of intake manifold Next, an embodiment of the present invention will be described with reference to the drawings. This embodiment is applied to an intake manifold of an internal combustion engine mounted on a vehicle. First, the basic structure of the intake manifold will be described mainly with reference to FIGS.

  In this specification, front / rear / left / right words are used to specify the direction, but the crank axis direction is specified as the left / right direction, and the horizontal direction perpendicular thereto is specified as the front / rear direction. The direction is specified in FIGS. With respect to the front-rear direction, the front direction is the front toward the cylinder head 1 and the front direction is the rear (therefore, the front-rear direction and the left-right direction are defined with reference to the cylinder head 1).

  When mounted on a vehicle, the intake manifold may be arranged on the front surface of the engine body facing the forward direction of the vehicle or on the rear surface opposite to the forward direction, but before and after this specification, It has nothing to do with this. The vertical direction is based on the axial direction of the cylinder bore. Although the drawing assumes a state in which the cylinder bore is in a substantially vertical posture, it is naturally applicable to a slant type internal combustion engine such as a forward tilt type.

  The main body of the intake manifold is composed of three parts, an upper part 2, a middle part 3 and a lower part 4, all of which are molded products of resin. The upper part 2 and the middle part 3 are welded together, The whole is integrated by welding the part 3 and the lower part 4 together. In FIG. 1 (A), parallel lines are attached to the middle part 3, and in FIG. 1 (B), parallel lines are displayed on the upper part 2 and the lower part 4, thereby making it easy to see the shape and boundary of the three parts. ing. Flange 2a, 3a, 4a is provided in the mating surface of each part 2,3,4. As the material for each of the parts 2, 3, and 4, a polyamide-based synthetic resin such as PA6 (polyamide 6 and nylon 6) containing glass fibers is used, but other types of synthetic resins may be used.

  Needless to say, the reason why the intake manifold is composed of the parts 2, 3 and 4 is that there is a restriction of die cutting at the time of molding. As shown in FIG. Is a container-like form opened downward, and the surge tank 5 is constituted by the upper part 2, the middle part 3 and the lower part 4.

  The present embodiment is an intake manifold for a three-cylinder internal combustion engine, and therefore includes first to third three branch pipes 6, 7, and 8 arranged in the left-right direction. Each of the branch pipes 6, 7, and 8 has a substantially circular shape in a side view in which the direction of the lower part 4 is changed from downward, forward, upward, and backward, starting from the position of the rear lower surface of the lower part 4. Accordingly, the intake air moves in a substantially circular shape (turns) toward the intake port of the cylinder head 1.

  The lower half of each branch pipe 6, 7, 8 is formed by the lower part 4, and the upper half is composed of the upper part 2 and the middle part 3. The lower part 4 is shown as a single structure in the figure, but is manufactured by joining a plurality of parts. The end portions of the branch pipes 6, 7, and 8 are linear portions 6a, 7a, and 8a that are substantially horizontal in a side view. Therefore, the intake air enters from the branch pipes 6, 7, 8 toward the intake port of the cylinder head 1 with straightness.

  As can be easily understood from FIG. 2, the interval between the start ends of the branch pipes 6, 7, and 8 is narrower than the interval between the end portions. For this reason, the lower half part of the 2nd branch pipe 7 and the 3rd branch pipe 8 is bent so that it may distance from the 1st branch pipe 6, so that it goes downstream.

  As can be easily understood from FIG. 1, the upper part of the middle part 3 is provided with a flange-like joint 9 in which outlet holes 6 b, 7 b, 8 b of the branch pipes 6, 7, 8 are opened. 9 is fixed to the cylinder head 1 with a plurality of bolts (not shown) via a spacer 10 (see FIG. 3) (the joint 9 may be directly fixed to the cylinder head 1). Therefore, the upper part 2 is arranged in front of the joint portion 10 in the middle part 3. A bolt insertion hole of the joint portion 9 is denoted by reference numeral 11. As shown in FIG. 1 (A), a space with ribs is vacant on the rear surface of the joint 9 for weight reduction, but a space with ribs is omitted in FIG. 2 (B).

For example, as shown in FIG. 1B , a hole 12 is formed in the upper part 2 between the first branch pipe 6 and the second branch pipe 7. For inserting a bolt and a wrench for fixing the lower left portion of the joint portion 9 to the cylinder head 1. Therefore, the middle part 3 has a cylindrical shape opened forward at the location of the hole 12.

  As shown in FIG. 1B, a throttle valve mounting seat for fixing a throttle valve 13 '(see FIG. 3) is provided at a position between the second branch pipe 7 and the third branch pipe 8 in the upper part 2. 13 is protrudingly provided. The throttle valve mounting seat 13 has a generally triangular shape, and an intake introduction hole 14 is formed at a substantially central portion, and screw holes 15 into which fastening screws are screwed are provided at three vertex portions.

  The throttle valve mounting seat 13 is arranged at a certain distance from the joint 9 of the middle part 3, and the axial center of the intake hole 14 (or the vertical of the seating surface) is closer to the front as it goes upward. It tilts forward in a side view so as to deviate. Accordingly, when the throttle valve is fastened with screws, the wrench is used in an obliquely downward posture.

(2). EGR distribution passage The upper part 2 constituting the intake manifold is provided with an EGR distribution passage for distributing and supplying EGR gas to the end portions of the branch pipes 6, 7, and 8. This point will be described with reference to other drawings.

  The EGR passage is provided at the rear end portion of the upper part 2, and as can be understood from FIG. 5, the upper part 2 is integrally formed in a posture crossing the straight portions 6a, 7a, 8a of the branch pipes 6, 7, 8 The EGR gas distribution portion 17 is formed, and a lid plate 18 is deposited on the EGR gas distribution portion 17 from above. The EGR gas distribution part 17 has an inlet part 19 that protrudes outside the group of branch pipes 6, 7, and 8 and on the side far from the throttle valve mounting seat 13, and the inlet part 19 includes an EGR pipe 20. A flange 23 fastened to the end plate 21 with a bolt 22 is integrally provided.

  As clearly shown in FIG. 3 (A), the flange 23 of the inlet 19 is substantially rhombus in side view, and an EGR gas inflow hole 24 is opened at the center thereof, and bolts are provided at both upper and lower ends. The insertion hole 25 is vacant.

  As shown in FIGS. 6 and 7B, the EGR gas distribution portion 17 includes a main EGR groove 26 that opens upward and extends to the position of the third branch pipe 8, and a rear side of the main EGR groove 26. A branch EGR groove 27 located between the first branch pipe 6 and the second branch pipe 7 and extending in parallel with the main EGR groove 26 and a communication groove 28 connecting both the groove type EGR passages 26 and 27 are formed. ing.

  On the other hand, a main EGR groove 26, a branch EGR groove 27, and a communication groove 28 are formed on the lower surface of the cover plate 18 corresponding to the upper part 2, and the main groove having a circular cross section is formed by the upper and lower main EGR grooves 26. The EGR passage is configured, and the upper and lower branch EGR grooves 27 form a branch groove EGR passage having a circular cross section. The upper and lower communication grooves 28 form an oval groove type EGR passage. Therefore, in this embodiment, the groove type EGR passage is formed by the grooves provided in both the EGR gas distribution portion 17 and the cover plate 18.

  As shown in FIG. 8A, a first outlet hole 29 opened to the first branch pipe 6 communicates with the right end of the branch EGR groove 27, and a second branch is formed at the left end of the branch EGR groove 27. A second outlet hole 30 opened in the pipe 7 communicates with the end of the main EGR groove 26, and a third outlet hole 31 opened in the third branch pipe 8 communicates. The first outlet hole 29 is inclined so as to approach the axis of the first branch pipe 6 as it goes downward. On the other hand, the second outlet hole 30 has a substantially vertical posture and opens at the right end portion of the second branch pipe 7. Further, the third outlet hole 31 is in a substantially horizontal posture (laterally) and opens toward the upper part of the third branch pipe 8. In the case of four cylinders, two branch EGR grooves 27 may be formed.

  Of the EGR gas distribution portion 17, the portion between the first branch pipe 6 and the second branch pipe 7 and the EGR gas inflow hole 24 side thereof are the main flat portions 17 a, and therefore the main EGR groove 26. Is in a straight posture between the first branch pipe 6 and the second branch pipe 7. The branch EGR groove 27 is also straight.

On the other hand, main EGR groove 26 of the EGR gas distribution unit 17, the second branch pipe 7 in a portion between the third branch pipe 8, the downward curved portion bent to enter toward the inside of the surge tank 5 For this reason, the third outlet hole 31 is opened to the third branch pipe 8 in a lateral orientation. One bolt insertion hole 11 in the upper part provided in the middle part 3 is located at a position above the curved portion 17b in the EGR gas distribution portion 17 in a front view. Therefore, the wrench can be used without any trouble when fastening the bolt.

  As shown in FIG. 8 (B), the upper part 2 is formed using a cavity mold 33 and a core mold 34 that sandwich the upper part 2 from above and below. By providing the molds 33 and 34 with the projections 33a and 34a, they can be molded by pulling out. Since the second outlet hole 29 faces the relative movement direction of both molds 33 and 34, there is no problem of die cutting. Moreover, since the 3rd exit hole 31 is shape | molded entirely by the protrusion provided in the core metal mold | die 34, it can shape | mold also in this case without a problem.

  As can be easily understood from FIGS. 6 and 7, the outlet holes 29, 30, and 31 are arranged in the left-right direction with the front and rear positions being substantially the same. That is, the outlet holes 29, 30, and 31 are generally aligned in a horizontal line. Accordingly, the curved portion 17b is bent in a plan view so that the end thereof is shifted toward the cylinder head 1 side.

  As shown in FIG. 9, by forming the upper surface of the inlet portion 19 located outside the first branch pipe 6 in the EGR gas distribution portion 17 with a step-shaped first end flat portion 17c higher than the main flat portion 17a, An end of the main EGR groove 26 is stopped at the upper part of the first branch pipe 6, an EGR gas inflow hole 24 is formed over substantially the entire length of the inlet portion 19, and a main groove type EGR passage constituted by upper and lower main EGR grooves 26 The EGR gas inlet hole 24 of the inlet 19 is concentric. Similarly, as shown in FIG. 9, a portion of the upper surface of the third branch pipe 8 in the EGR gas distribution portion 17 is a second end flat portion 17d.

  The cover plate 18 extends beyond the main EGR groove 26 so as to approach the flange 23. Accordingly, the portion of the cover plate 18 that overlaps the inlet portion 19 is a first extension portion 18 c that rises, and the first extension portion 18 c overlaps the first end flat portion 17 c of the EGR gas distribution portion 17. End flat part. Further, the end of the cover plate 18 opposite to the flange 23 is also a second extension 18d that extends beyond the end of the main EGR groove 26, and this second extension 18d is also the EGR gas distributor 17. The end flat portion overlaps the second end flat portion 17d.

  As described above, in the present embodiment, the branch EGR groove 27 is provided, and the cover plate 18 is also provided with the branch EGR groove 27. However, the entire cover plate 18 is matched to the width of the branch EGR groove 27 or the like. Instead of setting the width, only the portion of the main flat portion 17a where the branch EGR groove 27 is provided is set to be wide. For this reason, the volume of the EGR gas distribution part 17 and the cover board 18 can be suppressed, and it can reduce in weight.

  As shown in FIG. 10, in the main flat portion 17 a of the EGR gas distribution portion 17, auxiliary passages 36 with a very narrow interval are formed at locations of the partition portions 35 on both sides of the communication groove 28. The auxiliary passage 36 may be configured by lowering the upper surface of the partition portion 35 of the EGR gas distribution unit 17 or may be configured by increasing the lower surface of the partition portion 35 of the cover plate 18 as indicated by a one-dot chain line. Or both may be adopted.

  As shown in FIG. 11 and FIGS. 5, 6, and 7 (B), the upper surface of the EGR gas distribution unit 17 and the lower surface of the cover plate 18 are improved in adhesion during vibration welding using ultrasonic waves or the like. Two narrow ribs 37 having a low height are formed. The ribs 37 may be one by one, or three or more. Further, the rib 37 may be formed on only one of the EGR gas distribution portion 17 and the lid plate 18.

  As described above, the cover plate 18 extends further to the ends than the left and right ends of the main EGR groove 26, and the ribs 37 extend beyond both ends of the main EGR groove 26 and the EGR gas distributor 17 and the cover plate 18. It extends to the end. Therefore, the lid plate 18 is welded to the EGR gas distribution portion 17 with a wide area also on the left and right outer sides of the main EGR groove 26.

(3) Summary Next, advantages of the present embodiment will be described. In the present invention, since the EGR passage is composed of the EGR gas distribution portion 17 integrally formed with the upper part 2 and the cover plate 18 covered therewith, the upper part 2 is injected using the molds 33 and 34. It can be easily manufactured by molding. Therefore, although it is an intake manifold integrally provided with an EGR passage, it can be easily formed as a resin molded product, contributing to cost reduction and weight reduction.

Further, since the EGR gas distribution portion 17 and the cover plate 18 are provided with the main flat portions 17a and 18a and the end flat portions 17c, 17d, 18c, and 18d), when the cover plate 18 is vibration welded to the EGR gas distribution portion 17. Adhesion is improved . For this reason, the joint strength of the cover plate 18 can be significantly improved.

  In addition, since both ends of the cover plate 18 are extended to the outside of the main EGR groove 26, the welding area can be increased to improve the bonding strength. Further, as described above, since both the extension portions 18c and 18d are formed as flat portions in accordance with the end flat portions 17c and 17d of the EGR gas distribution portion 17, the vibration can be stably performed when fixing by vibration welding. At the same time, the adhesion can be made uniform, and the bonding strength can be increased.

  Furthermore, since the main flat portions 17a and 18a have the front and rear widths larger than other portions due to the formation of the branch EGR grooves 27, high joint strength can be secured at the portions of the main flat portions 17a and 18a. As a result, the effect of the pressure of EGR gas and heat can be eliminated, and high bonding strength can be ensured.

Now, if only the main EGR groove 26 exists in the EGR passage, the EGR gas easily passes through the outlet holes 29 and 30 of the first branch pipe 6 and the second branch pipe 7 without passing through. On the other hand, when the branch EGR groove 27 parallel to the main EGR groove 26 is provided and the outlet holes 29 and 30 are provided at both left and right ends as in the embodiment, the EGR gas is branched from the communication groove 28 having a large opening area. There is an advantage that the EGR gas can be accurately guided to the outlet holes 29 and 30 by accurately diverting into the groove 27.

Furthermore, since the three cylinders take in the air in order, the EGR gas is supplied to the three outlet holes 29, 30, and 31 in order, but each of the outlet holes 29, 30, and 31 is provided at the end of the passage. Therefore, the EGR gas enters the outlet holes 29, 30, and 31 with straightness, and therefore, the EGR gas can be accurately supplied to the branch pipes 6, 7, and 8.

  Furthermore, in this case, if the narrow auxiliary passage 36 is provided at the partition portion 35 between the main EGR groove 26 and the branch EGR groove 27, there is an advantage that the flow rate of the EGR gas can be easily adjusted. That is, if the EGR gas supply amount to the first and second branch pipes 6 and 7 is adjusted only by changing (trimming) the cross-sectional area of the communication groove 28, the supply amount of EGR gas can be reduced by a slight difference in cross-sectional area. However, it is difficult to set the EGR gas supply amount (selection of dimensions). However, since the auxiliary passage 36 is long in the left and right directions, the adjustment allowance can be adjusted by adjusting the left and right lengths or the vertical groove width. This makes it possible to easily finely adjust the passage amount of the EGR gas while increasing the value.

  In addition, since the front and rear positions of the outlet holes 29, 30, and 31 are aligned, the amount of EGR gas supplied to the branch pipes 6, 7, and 8 can be made uniform to contribute to stabilization of combustion. In addition, since the outlet holes 29, 30, and 31 are close to the joint 9, the EGR gas touches only the inner surface of the end portions (6a, 7a, 8a) of the branch pipes 6, 7, and 8, and accordingly , Dirt of each branch pipe 6, 7, 8 can be suppressed.

  Furthermore, since one bolt insertion hole 11 of the joint portion 9 is located at the curved portion 17b, EGR gas is accurately supplied to the branch pipes 6, 7, and 8 while ensuring ease of bolt fastening. it can. Further, the EGR gas flows straight through the main EGR groove 26, but the curved portion 17b becomes a resistance and the flow rate is suppressed, so that a large amount of EGR gas is supplied only to the third branch pipe 8. Can also be prevented.

Further, since the curved portion 17b is bent backward in plan view, the throttle valve mounting seat 13 can be shifted as far back as possible. As a result, the throttle valve 13 'can be moved as close to the cylinder head 1 as possible, which can contribute to the downsizing of the internal combustion engine.

In this case, when the EGR gas distribution part 17 is arranged on the straight parts 6a, 7a, 8a of the branch pipes 6, 7, 8 as in this embodiment, the volume of the EGR gas distribution part 17 is reduced as much as possible, and the weight is reduced. You can contribute to the reduction (if provided EGR gas distribution unit 17 to the circular portion, the height from the branch pipe 6, 7, 8 at the location of the front and rear longitudinal side edges of the EGR gas distribution part 17 is increased, it just EGR gas There is a possibility that the volume of the distribution part 17 may increase.)

  Moreover, in this embodiment, each exit hole 29,30,31 is located between the axial centers of the adjacent branch pipes 6,7,8 (namely, each exit hole 29,30,31 is In this way, the height of the outlet holes 29, 30, and 31 can be lowered, so that the EGR gas distribution is possible. By reducing the thickness of the portion 17 as much as possible, the intake manifold can be made compact and lightweight.

(4). Others The present invention can be embodied in various ways other than the above embodiment. For example, the embodiment is applied to an intake manifold for three cylinders, but can also be applied to an intake manifold having two cylinders or four or more cylinders. In the case of two cylinders, an L-shaped branch EGR passage is provided upstream from the first branch pipe, EGR gas is supplied to the first branch pipe from the end thereof, and EGR is supplied from the end of the main EGR passage to the second branch pipe. Supply gas.

  In the case of four cylinders, a T-shaped first branch EGR passage is provided between the first branch pipe and the second branch pipe, and an L-shaped second branch is provided between the second branch pipe and the third branch pipe. It is possible to employ a configuration in which a branch EGR passage is provided and the end thereof communicates with the third branch pipe, and a bent portion is provided in the main EGR passage between the third branch pipe and the fourth branch pipe. Alternatively, two T-shaped branch EGR passages are provided between the first branch pipe and the second branch pipe and between the third branch pipe and the fourth branch pipe, respectively, and an outlet hole is formed at the end thereof. It may be provided.

  Further, the branch pipe does not need to be bent in a circular shape when viewed from the side, and may be linear or L-shaped (or J-shaped). When the main body of the intake manifold is composed of a plurality of parts, it is possible to join parts separated in the front-rear direction.

  The present invention can actually be embodied in a resin intake manifold. Therefore, it can be used industrially.

DESCRIPTION OF SYMBOLS 1 Cylinder head 2 Upper part which comprises the main body of an intake manifold 3 Middle part which comprises the main body of an intake manifold 4 Lower part which comprises the main body of an intake manifold 5 Surge tank 6, 7, 8 Branch pipe 17 EGR gas distribution part 17a, 18a Main flat portion 18 Cover plate 19 Inlet portion 20 EGR piping 24 EGR gas inflow hole 26 Main EGR groove constituting main EGR passage 27 Branch EGR groove constituting branch EGR passage 28 Communication groove constituting EGR communication passage 29, 30 , 31 Outlet hole (communication hole)
35 Partition 36 Auxiliary passage

Claims (1)

A laterally long EGR gas distribution part extending so as to cross the branch pipe group is integrally provided on the outer surface of the group of the plurality of branch pipes arranged in parallel, and a lid plate is welded to the EGR gas distribution part. The EGR passage is provided on the mating surface with the lid plate,
The EGR passage, a main EGR passage having an EGR gas inflow hole, is constituted by said branch EGR passage be connected to a communication passage extending in parallel the main EGR passage substantially branched from the main EGR passage,
An auxiliary passage having a narrow groove width through which EGR gas can pass is formed on the mating surface of the partition that separates the main EGR passage and the branch EGR passage.
Intake manifold with EGR gas distribution function.

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