JP2015163768A - Intake manifold with egr gas distribution function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To assure a strength of an EGR gas distribution part while assuring an easiness in molding a composing member when an intake manifold is made by resin and an EGR passage is integrally arranged with it.SOLUTION: A branch pipe 6 of an intake manifold is constituted by an upper element 2, a middle element 3 and a lower element 4 that are injection molded components. The upper surface of the upper element 2 is provided with an EGR gas distributing part 17 crossing the branch pipe 6. A cover plate 18 is welded and fixed to its upper surface. A mating surface between the EGR gas distributing part 17 and the cover plate 18 is formed with a groove-type EGR passage constituted by an EGR groove 26. The cover plate 18 is provided with an inlet part 19 protruded to outside a group of branch pipes 6, 7, 8. The inlet part 19 has an EGR gas flow-in hole 24 that is not a groove, the EGR gas flow-in hole 24 and the main EGR groove 26 are concentrically communicated to each other. Since the inlet part 19 is an integral structure, it is superior in its strength and at the same time a sealing characteristic when it is connected in flange to the EGR pipe is also superior.

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 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.

Japanese microfigures in Japanese Utility Model Sho 63-177653 Japanese micro-fimu of 03-1561

  Providing the EGR passage integrally with the intake manifold has the advantage of eliminating problems such as loosening due to vibration, the ability to reduce the assembly effort, and the ability to ensure 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 solved by making the intake manifold a molded product using a mold, such as a molded product made of resin or a die-cast product made of light metal such as aluminum. However, in the case of a molded product using a mold, there are restrictions on the shape from the point of die cutting, and it is difficult to mold with a hollow EGR passage (manufacturing is impossible when the passage is bent) become.).

  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 grooved EGR passage is formed on the mating surface of both. However, if the inlet of the EGR passage is formed up to the cover plate, it is troublesome to connect the EGR conduit to the EGR passage, the strength of the connection portion with the inlet conduit, or the EGR conduit There is a risk that the sealing performance will deteriorate.

  The present invention has been made to improve the current situation. Further, the present application discloses various improved configurations related to an intake manifold molded from a resin or the like, but these can also be provided as independent inventions.

  An intake manifold according to the present invention includes a plurality of branch pipes arranged in parallel, and an EGR gas distribution portion extending in a direction crossing the branch pipe is integrally provided on an outer surface of the branch pipe. And a groove type EGR passage made of a groove formed in one or both of the EGR gas distribution part and the cover plate is provided in the overlapping part of the EGR gas distribution part and the cover plate, This is a basic configuration in which EGR gas is supplied from the grooved EGR passage to each branch pipe.

  One end portion of the EGR gas distribution portion is an inlet portion that protrudes outside the group of branch pipes and does not overlap the lid plate, and the EGR communicated with the grooved EGR passage at the inlet portion. A gas inflow hole is provided.

  In addition, although an intake manifold single structure product may be sufficient, in the case of a molded product such as a resin molded product, it is generally manufactured by joining a plurality of parts. A structure in which a surge tank is provided integrally is also included.

  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 molding using a (mold). That is, although the intake manifold is integrally provided with an EGR passage, a molded product of synthetic resin or an aluminum die-cast product can be adopted, which can contribute to cost reduction and weight reduction.

  The EGR passage provided in the intake manifold is composed of a grooved EGR passage and an EGR gas inflow hole, and the entire inlet portion provided with the EGR gas inflow hole has an integral structure. Can be easily connected, and high sealing performance can be secured with respect to the joint with the EGR pipe, and the joint strength with the EGR pipe can be improved by securing a high strength at the inlet portion.

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 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 shows the cylinder bore in a substantially vertical position, it can be applied 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 parts of synthetic resin, and welds the upper part 2 and the middle part 3, The whole is integrated by welding the middle part 3 and the lower part 4. 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, the material of each part 2, 3, and 4 can use polyamide-type synthetic resin like PA6 (polyamide 6, nylon 6) containing glass fiber.

  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).

  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 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. 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 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.

  A portion of the EGR gas distribution portion 17 between the first branch pipe 6 and the second branch pipe 7 is a flat portion 17a. Therefore, the main EGR groove 26 is formed in the first branch pipe 6 and the second branch pipe. 7 is in a straight posture. The branch EGR groove 27 is also straight.

  On the other hand, the EGR gas distribution part 17 has a main EGR groove 26 at a portion between the second branch pipe 7 and the third branch pipe 8 in a downward curved part 17b bent so as to enter 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 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.

  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 substantially the same front-rear position. That is, the outlet holes 29, 30, and 31 are generally aligned in a horizontal line. Therefore, 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 stepped first end flat portion 17c higher than the 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, 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, contributing to cost reduction and weight reduction.

  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 connection with the EGR pipe line 20 is simple, the sealing property 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. The joint strength with the path 19 can also be improved.

  In the present embodiment, the EGR gas inflow hole 24 also exists between the flange, 23 and the main EGR groove 26 (that is, the EGR gas inflow hole 24 is provided over the entire length of the inlet portion 19. However, it is also possible to provide the EGR gas inflow hole 24 only at the flange 23. However, if the EGR gas inflow hole 24 is provided over the entire length of the inlet portion 19 as in this embodiment, there is an advantage that the rigidity of the inlet portion 19 is increased.

  Furthermore, the present embodiment has various advantages that depart from the claims. For example, when the EGR gas distribution unit 17 and the cover plate 18 are bent in a front view, and the EGR gas distribution unit 17 and the cover plate 18 are provided with flat portions 17a (17c, 17d), the EGR gas distribution unit 17 is covered. Since the adhesion is improved when vibration welding is performed on the plate 18, the bonding strength of the lid plate 18 can be remarkably improved.

  Further, when the portion between the second branch pipe 7 and the third branch pipe 8 of the EGR gas distribution portion 17 is formed as the downward curved portion 17b as in the present embodiment, the ease of bolt fastening is secured. EGR gas can be accurately supplied to the branch pipes 6, 7, and 8. 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.

  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.

  Moreover, if both ends of the cover plate 18 are extended to the outside of the main EGR groove 26, the welding area can be increased and the bonding strength can be improved. In particular, as described above, when both the extension portions 17c and 17d are formed in a flat shape in accordance with the end flat portions 17c and 17d of the EGR gas distribution portion 17, the vibration can be stably applied and firmly adhered when fixed by vibration welding. Since it becomes uniform, the bonding strength can be increased.

  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.

  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), 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.

  Furthermore, when the flange 23 of the inlet 19 is inclined in a side view so that the upper end is closer to the cylinder head 1 and the lower end is away from the cylinder head 1 as in the embodiment, the bolt 22 The position is easy to see and the wrench is easy to operate, so the burden on the operator can be reduced (if the EGR passages of Patent Documents 1 and 2 are joined to the EGR pipe by flange joining, the flange 23). If the posture is oriented vertically, the lower bolt insertion hole 25 is difficult to see, and if the flange 23 is in a horizontal posture, the rotating operation of the rear bolt is troublesome.)

  Furthermore, if the throttle valve is attached to the throttle valve attachment seat 13, the center of gravity of the intake manifold is closer to the third branch pipe 8, so that vibration may occur easily. However, as in the present embodiment, the EGR gas distributor 17 If the EGR gas inflow hole 24 is protruded to the opposite side of the throttle valve mounting seat 13, the inlet 19 can act as a balancer and the center of gravity can be brought closer to the left and right middle portions of the intake manifold, contributing to vibration suppression. You can do it.

  Further, the heat of the EGR gas tends to escape upward from the EGR gas distribution part 17 and the cover plate 18, but when the EGR gas distribution part 17 is arranged on the surge tank 5 as in the embodiment, the EGR gas distribution part 17 In addition, the heat dissipation from the cover plate 18 can be improved, and the EGR gas distribution unit 17 is cooled by atmospheric air from below, so that the cooling performance of the EGR gas distribution unit 17 and the cover plate 18 (and the EGR gas (Coolability) can be further 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 can also be applied to an intake manifold having two cylinders or 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).

  Furthermore, the connection method of the EGR pipe does not need to be a flange joint. The EGR pipe is inserted into a cylindrical boss provided at the inlet from the outside or the inside, or the EGR pipe is inserted into the EGR gas inflow hole of the inlet. May be used. Of course, a pipe joint may be used. 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 portion 13 Throttle valve mounting seat 17 EGR gas distribution portion 18 Cover plate 19 Inlet portion 20 EGR piping 24 EGR gas inflow hole 26 Main EGR groove constituting main groove type EGR passage 27 Branch groove type EGR passage as branch EGR groove 28 groove Type EGR communication passage composing groove 29, 30, 31 Exit hole (communication hole)
33, 34 Mold 35 Partition wall 36 Auxiliary passage 37 Rib for welding

Claims (1)

A plurality of branch pipes arranged in parallel; an EGR gas distribution portion extending in a direction crossing the branch pipe is integrally provided on an outer surface of the branch pipe, and a lid plate is fixed to the EGR gas distribution section; A grooved EGR passage made of a groove formed in one or both of the EGR gas distribution portion and the cover plate is provided in the overlapping portion of the distribution portion and the cover plate. EGR gas is supplied to each branch pipe,
One end portion of the EGR gas distribution portion is an inlet portion that protrudes outside the group of branch pipes and does not overlap the lid plate, and an EGR gas inflow communicating with the grooved EGR passage into the inlet portion. A hole,
Intake manifold with EGR gas distribution function.

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