JP2015163769A - Resin-made intake manifold with egr gas distribution function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize to facilitate an integral arrangement of an EGR passage at a resin-made intake manifold.SOLUTION: A branch pipe 6 of an intake manifold is constituted by an upper element 2 and a lower element 4 that are injection molded products. The upper surface of the upper element 2 is provided with an EGR gas distribution segment 17 in an attitude crossing over the branch pipe 6, and a cover plate 18 is welded and fixed to its upper surface. A mating surface between the EGR gas distribution segment 17 and the cover plate 18 is formed with a groove-type EGR passage constituted by an EGR groove 26. Since the upper element 2 can be easily manufactured by an injection molding, it is possible to provide the resin-made intake manifold integrally formed with the EGR passage. Since the EGR gas distribution segment 17 and the cover plate 18 have not only flat segments 17a, 18a but also downward-faced curved segments 17b, 18b, they are superior in a welding and fixing characteristic and the EGR gas distribution characteristic.

Description

  The present invention relates to a resin 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 so as to cross 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.

  On the other hand, although the intake manifold is made of resin, when the intake manifold is made of resin, the intake manifold itself is not provided with an EGR passage. A spacer plate is arranged between them, and an EGR passage is provided in this spacer plate (for example, Patent Document 1).

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

  When the EGR passage is provided integrally with the intake manifold, there are advantages that the number of members can be reduced and the assembly efficiency of the engine can be improved, problems such as loosening due to vibration can be eliminated, and sealing performance can be ensured. In addition, since a metal casting 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.

  It can be said that this problem can be solved by making the intake manifold a resin-made product (in this case, the intake manifold needs to be composed of a plurality of parts and joined to each other). However, the shape of the resin molded product is limited in terms of die-cutting, and it is difficult to mold the EGR passage with a hollow shape (if the passage is bent, it becomes impossible to manufacture).

  When the tubular EGR passage, which is a separate member, is fixed to the intake manifold, as in Patent Document 2, it takes time and effort, so the meaning of integration is reduced. If the EGR passage is bent, the EGR passage itself is made up of multiple parts. Therefore, the meaning such as cost reduction is lost.

  The present invention has been made to improve such a current situation, and provides a resin intake manifold integrated with an EGR passage in a state where it can be reasonably manufactured, and has been improved in relation thereto. The object is to provide an intake manifold.

  The present invention includes a number of configurations, the typical of which is specified in each claim. Among these, the invention of claim 1 is a resin intake manifold having a plurality of branch pipes arranged in parallel, and an EGR gas distribution extending in a direction crossing the branch pipes on an outer surface of the branch pipe group A cover plate is welded and fixed thereto, and an EGR passage is provided on the mating surface between the EGR gas distribution portion and the cover plate, and the EGR passage and each branch pipe communicate with each other through an outlet hole. .

  The invention of claim 2 embodies claim 1, and this invention has three or more branch pipes and a plurality of inter-branch portions, and among the plurality of branch pipe portions, In some cases, the EGR gas distribution part is flat, and the remaining branch pipe part has a curved part that is bent so as to be recessed from the flat part, and the EGR gas distribution part has a flat part in the EGR gas distribution part. A branch EGR passage extending substantially parallel to the main EGR passage toward the curved portion is provided, and the outlet holes are provided at both ends of the branch EGR passage.

  A third aspect of the present invention is a specific example of the second aspect of the present invention. In the present invention, a flange-like joint portion fixed to one side surface of the cylinder head with a bolt is provided at the end portion of the branch pipe. On the other hand, the EGR gas distribution part is provided near the end part of the branch pipe group, and when viewed from the direction facing one side surface of the cylinder head, the EGR gas distribution part is located above the curved part in the EGR gas distribution part. One or more bolt insertion holes are provided in the site.

  It should be noted that the inter-branch portion of claims 2 and 3 means a portion between the vertices of the branch pipe, and does not mean a portion excluding the branch portion. It does not exclude that the flat portion or the curved portion protrudes outside the apex of the branch pipe.

  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 a molding method using Therefore, it is possible to reduce the size and weight and reduce the cost, and to improve the assembly efficiency of the engine.

  In addition, since the lid plate is welded to the EGR gas distribution section, the EGR passage can ensure high sealing performance, and the screw holes are not required as in the case of fastening with bolts. Furthermore, there is no problem that the bolt head is exposed and the object is caught.

  Since the flow of EGR gas has straightness, it tends to flow strongly toward the end. However, when a curved portion is provided as in claim 2, the flow rate of EGR gas flowing through the main EGR passage is reduced by the curved portion. Therefore, the distribution of the EGR gas to the branch EGR passage can be ensured.

  Since the plurality of intake ports open in order, EGR gas is supplied to the plurality of branch pipes in order from the outlet hole. However, since the outlet holes are provided at both ends of the branch EGR passage, the branch EGR passage goes straight in the branch EGR passage. The EGR gas flowing with the property is surely discharged from each outlet hole to each branch pipe. In this respect as well, the EGR gas distribution is excellent.

  In the invention of claim 2, since the branch EGR passage is provided, the width of the EGR gas distribution part and the cover plate is widened at the branch EGR passage, so that the welding area of the cover plate is increased and the bonding strength is increased. Can be up. Furthermore, since the curved portion is bent so as to be lowered from the flat portion, the thickness of the curved portion can be reduced to contribute to weight reduction and compactness.

  If the structure of Claim 3 is employ | adopted, since a wrench can be operated from the location of a curved part and a junction part can be fastened to a cylinder head, EGR gas distribution to an intake manifold is not impaired, without impairing the function which can fasten a joint part to a cylinder head firmly Can have a function.

  In the case of four cylinders, there are three inter-branch portions. In this case, a combination of two flat portions and one curved portion may be used, or a combination of one flat portion and two curved portions. It may be. The same applies to the case of 6 cylinders or more.

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 closed with 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 disposed on the front surface of the engine body facing the forward direction of the vehicle or on the rear surface, but the front and rear of this specification are not related to this front and rear. . 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 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. In addition, although the polyamide type synthetic resin like PA6 (polyamide 6, nylon 6) containing glass fiber is used for the material of each part 2, 3, and 4, you may use another kind of resin. .

  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 during molding. As shown in FIG. 8A, the middle part 3 has a container-like shape opened downward, and the upper part 2, the middle part 3 and the lower part 4 constitute a surge tank 5.

  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. The joint 9 has bolt insertion holes 11 at a plurality of locations along the circumferential direction. 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).

  In the upper part 2, there is a hole 12 at a position between the first branch pipe 6 and the seventh part. This hole 12 fixes the lower left part of the joint 9 in the middle part 3 to the cylinder head 1. It is for inserting a bolt and a wrench. 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 hole 14 is formed at a substantially central portion, and screw holes 15 into which fastening screws are screwed are provided at three apex 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 passage The upper part 2 constituting the intake manifold is provided with an EGR passage for distributing and supplying EGR gas to the end portions (straight portions 6a, 7b, 8b) of the branch pipes 6, 7, 8 ing. 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. The flange 23 is inclined in a side view so that the upper end is close to the cylinder head 1 and the lower end is away from the cylinder head 1.

  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 that is located between the first branch pipe 6 and the second branch pipe 7 and extends parallel to the main EGR groove 26, and a communication groove 28 that connects the two-groove EGR passages 26, 27 are provided. Is formed.

  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.

  Since the present embodiment has three branch pipes 6, 7, 8, an inter-branch portion between the first branch pipe 6 and the second branch pipe 7, and the second branch pipe 7 and the third branch. There are two inter-branch parts with an inter-branch part between the tubes 8. In the EGR gas distribution portion 17, the inter-branch portion between the first branch pipe 6 and the second branch pipe 7 is a flat portion 17 a, and thus the main EGR groove 26 is connected to the first branch pipe 6. It is in a straight posture with the second branch pipe 7. The branch EGR groove 27 is also straight when viewed from the front.

  On the other hand, the EGR gas distributor 17 has a main EGR groove 26 which is bent downward so as to enter the inside of the surge tank 5 at the portion between the second branch pipe 7 and the third branch pipe 8. For this reason, the third outlet hole 31 is opened to the third branch pipe 8 in a lateral orientation. One upper bolt insertion hole 11 provided in the middle part 3 is located at a position above the downward curved portion 17b of 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.

  That is, the first outlet hole 29 in the inclined posture can be easily formed by the pair of molds 33 and 34 without using a slide shape. This is one of the advantages of this embodiment. In this case, the line connecting the upper end 29a and the lower end 29b of the first outlet hole 29 needs to be located at the position of the mating surface of both the protrusions 332a and 33b. The EGR gas inflow hole 24 and the bolt insertion hole 25 of the flange 23 are formed by a slide pin that is slidably provided in one of the molds 33 and 34.

  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 substantially the same front-rear position. That is, the outlet holes 29, 30, and 31 are generally aligned in a horizontal line. Accordingly, the downward 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, the upper surface of the inlet portion 19 located outside the first branch pipe 6 in the EGR gas distribution portion 17 is formed into a step-shaped first end flat portion 17 c higher than the flat portion 17 a, thereby The end of the EGR groove 26 is stopped at the upper part of the first branch pipe 6 to form an EGR gas inflow hole 24 over substantially the entire length of the inlet portion 19, and the main groove type EGR passage and the inlet constituted by the upper and lower main EGR grooves 26. The EGR gas inflow hole 24 of the part 19 is concentric. Similarly, as shown in FIG. 9, the portion of the upper surface of the third branch pipe 8 in the EGR gas distribution portion 17 is a second end flat portion 17 d.

  The cover plate 18 extends beyond the main EGR groove 26 so as to approach the flange 23. Therefore, the portion of the lid plate 18 that overlaps the inlet 19 is a flat first extension 18c that rises. Further, the end portion of the cover plate 18 opposite to the flange 23 is also a second extension portion 18e extending beyond the end of the main EGR groove 26, and this second extension portion 18e is also the EGR gas distribution portion 17. This flat portion overlaps the second 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 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 flat EGR gas distribution portion 17 a in the EGR gas distribution portion 17, auxiliary passages 36 with very narrow intervals are formed at the 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. First, in relation to the claims, 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 Can be easily manufactured by injection molding using the molds 33 and 34. Therefore, although it is an intake manifold integrally provided with an EGR passage, it can be easily formed as a resin molded product, which can contribute to cost reduction and weight reduction. Moreover, since the cover plate 18 is integrated with the EGR gas distribution part 17 by welding, it has excellent sealing properties and can be made compact.

  The EGR gas distribution unit 17 and the cover plate 18 include flat portions 17a (17c, 17d), 18a (18c, 18d) and downward curved portions 17b, 18b, but the flat portions 17a (17c, 17d), 18a. The presence of (18c, 18d) improves adhesion when the EGR gas distribution portion 17 is vibration welded to the lid plate 18, so that the bonding strength of the lid plate 18 can be significantly improved.

  Further, since the inter-branch portion between the second branch pipe 7 and the third branch pipe 8 in the EGR gas distribution part 17 is formed as a downward curved part 17b, it is easy to fasten the joint part 9 with a bolt. EGR gas can be accurately supplied to the branch pipes 6, 7, and 8 while ensuring the property. Further, the EGR gas flows straight through the main EGR groove 26, but the downward 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. Problems can also be prevented.

  Further, if the EGR passage is only the main EGR groove 26, the EGR gas easily passes through the outlet holes 19 and 30 of the first branch pipe 6 and the second branch pipe 7, but as in the embodiment. If a branch EGR groove 27 parallel to the main EGR groove 26 is provided at the right and left ends, and outlet holes 29 and 30 are provided at both left and right ends thereof, the EGR gas can be accurately diverted from the communication groove 28 having a large opening area to the branch EGR groove 27 There is an advantage that the EGR gas can be accurately guided to the outlet holes 29 and 30.

  Further, since the three cylinders suck in order, the EGR gas is supplied to the three outlet holes 29, 30, and 31 in order, but is provided at the end of any of the outlet holes 29, 30, and 31. Therefore, the EGR gas enters the outlet holes 29, 30, and 31 with straightness, so that the EGR gas can be accurately supplied to the branch pipes 6, 7, and 8.

  Further, if the branch EGR grooves 27 are provided at the locations of the flat portions 17a and 18a, the front and rear widths of the flat portions 17a and 18a are increased, so that the welding area can be increased and the bonding strength can be increased. In addition, since both ends of the cover plate 18 are extended to the outside of the main EGR groove 26, the welding area is also increased in this respect and the bonding strength is improved. In particular, if both the left and right ends of the EGR gas distribution part 17 and the cover plate 18 are configured to be flat parts 17c, 17d, 18c, 18d, the vibration can be stably fixed and the adhesion can be made uniform when fixed by vibration welding. Bonding strength can be increased.

  When the downwardly curved portion 17b of the main EGR groove 26 is bent backward and the outlet holes 29, 30, and 31 are arranged in a horizontal straight line, the EGR gas supply timing to the branch pipes 6, 7, and 8 can be aligned. In addition, since the throttle valve mounting seat 13 can be moved as close to the cylinder head 1 as possible, it is possible to contribute to the compactness of the engine and the effective use of space.

  When the branch EGR groove 27 is provided, the provision of the narrow auxiliary passage 36 at the partition portion 35 between the main EGR groove 26 and the branch EGR groove 27 has 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), but the auxiliary passage 36 has a long left and right length. This makes it possible to easily finely adjust the passage amount of the EGR gas while increasing the value.

  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.

  Further, if the throttle valve mounting seat 13 and the EGR gas distributor 17 are arranged on the surge tank 5, the space above the surge tank 5 can be used effectively. However, the EGR gas distributor 17 is throttled as in this embodiment. If it is arranged behind the valve mounting seat 13, the dead space behind the throttle valve mounting seat 13 can be used effectively to contribute to the compactness of the intake manifold.

  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. (If the EGR gas distribution part 17 is provided in a circular part, the height from the branch pipes 6, 7, 8 is higher at the end part (longitudinal side edge) in the width direction of the EGR gas distribution part 17). Therefore, there is a possibility that the volume of the EGR gas distribution unit 17 may increase accordingly.)

  Furthermore, if the EGR gas distribution part 17 is provided in the circular part of the branch pipes 6, 7, 8, the intake air tends to flow tangentially in the circular part of the branch pipes 6, 7, 8, The EGR gas may tend to be returned to the outlet holes 29, 30, 31, but the EGR gas distributor 17 is connected to the straight portions 6 a, 7 a, 8 a of the branch pipes 6, 7, 8 as in this embodiment. Since the EGR gas ejected from the outlet holes 29, 30, and 31 is quickly carried to the cylinder head 1 by the intake air flowing with straightness, the outlet holes 29, 30, It is possible to prevent deposits from adhering to the opening edge of 31.

  The EGR passage is composed of EGR grooves 26, 27, and 28 and a grooved EGR passage and a straight EGR gas inflow hole 24. Since the inlet portion 19 has an integral structure as a whole, the inlet portion 19 and the EGR pipe The connection with the passage 20 is simple and the sealing performance between the flange 20 of the EGR pipe line 19 can be ensured to be high, and the strength of the inlet portion 19 is ensured to be high, so that the EGR pipe line 19 The joint strength can be improved.

(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 as already mentioned, it can also be applied to an intake manifold having four or more cylinders. 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 also be applied to a die-cast intake manifold. The lid plate may be fastened with bolts.

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

1 Cylinder head 2 Upper part constituting main body of intake manifold 3 Middle part constituting main body of intake manifold 4 Lower part constituting main body of intake manifold 5 Surge tank 6, 7, 8 Branch pipe 9 Fixed to cylinder head Joint part 13 Throttle valve mounting seat 17 EGR gas distribution part 17a, 18a Flat part 17b, 18b Downward curved part 17c, 18d End flat part 18 Cover plate 18c, 18d Extension part 19 Inlet part 20 EGR piping 24 EGR gas inflow hole 26 Main Main EGR groove constituting groove type EGR passage 27 Branch groove type EGR passage as branch EGR groove 28 Communication groove constituting groove type EGR communication passage 29, 30, 31 Outlet hole (communication hole)
33, 34 Mold 37 Rib for welding

Claims (3)

A resin intake manifold having a plurality of branch pipes arranged in parallel,
An EGR gas distribution part extending in a direction crossing each branch pipe is integrally provided on the outer surface of the group of branch pipes, and a lid plate is fixed thereto by welding, and is attached to a mating surface between the EGR gas distribution part and the lid plate. An EGR passage is provided, and the EGR passage and each branch pipe are communicated with each other through an outlet hole.
Plastic intake manifold with EGR gas distribution function. It has three or more branch pipes and has a plurality of inter-branch portions. In some of the plurality of branch pipe portions, the EGR gas distribution portion is flat and the remaining branch pipe portions are not provided. It is a curved portion bent so as to be recessed from the flat portion, and a branch EGR passage extending substantially parallel to the main EGR passage toward the curved portion is provided in the flat portion of the EGR gas distribution portion, The outlet holes are provided at both ends of the branch EGR passage.
The resin intake manifold with an EGR gas distribution function according to claim 1. The end portion of the branch pipe is provided with a flange-like joint fixed to one side of the cylinder head with a bolt, while the EGR gas distribution portion is provided near the end portion of the branch pipe group, One or a plurality of bolt insertion holes are provided in a portion of the joint portion above the curved portion in the EGR gas distribution portion as seen from the direction facing one side surface of the cylinder head.
A resin intake manifold with an EGR gas distribution function according to claim 2.

Images