Intake manifold

Abstract

To provide an intake manifold capable of reducing the number of part items, simplifying a structure, facilitating molding, facilitating and ensuring vibration welding, and surely holding a flame-extinguishing element.SOLUTION: The intake manifold includes: a surge tank St elongated in the direction of a straight line X and a first half of a plurality of branch pipes Bp; a cylindrical portion 120 having an intake port, a receiving portion, and fitting holes in that order, centered on an axis S intersecting the straight line X; a base member 100 defining a first joint, and second halves of the surge tank and the plurality of branch pipes; a cover member 200 defined by a second joint joined to the first joint and joined to the base member; and a flame quenching element 300; wherein the first and second joining portions 130 and 230 are spaced apart from the fitting holes in the linear direction so that joining surfaces 130a1 and 230a1 define a void 124 between the first joining portion 130 and the fitting holes in a plane parallel to the line X, and the cover member includes a restricting portion 220 facing the cavity portion on the side opposite to the receiving portion, adjacent to the peripheral edge of the flame quenching element, and restricting the element from slipping out.SELECTED DRAWING: Figure 17

Description

[Technical Field]

[0001] The present invention relates to a resin intake manifold that is applied to the intake system of an engine, and in particular to an intake manifold that has a flame arrestor disposed near the intake port and is formed by joining multiple molded members together by vibration welding. [Background technology]

[0002] A known conventional intake manifold includes an intake port, a recessed mounting portion with a semi-cylindrical surface formed inside the intake port, a base member that defines the chamber and half of the branch passages, a flame quenching device as a flame quenching element fitted into the mounting portion, a flame quenching device fixing member that presses the flame quenching device radially, a covering portion that covers the flame quenching device fixing member, and a cover member that defines the chamber and half of the branch passages, and the base member, flame quenching device fixing member, and cover member are joined simultaneously at their joints by vibration welding (see, for example, Patent Document 1).

[0003] This intake manifold requires a dedicated flame quenching device fixing member for fixing the flame quenching device in the radial direction, which increases the number of parts, complicates the structure, and increases costs. In addition, the arc-shaped joint between the flame quenching device fixing member and the intake port is formed as an approximately semi-cylindrical surface centered on the axis of the intake port, and the joint in the region of the chamber and branch passage is formed as a band-shaped flat surface and a curved surface parallel to the longitudinal axis of the chamber.

[0004] When vibration welding is performed, it is preferable that all of the joining surfaces of the joint between the base member and the cover member are parallel to the vibration direction of the vibration welding and are elongated in the vibration direction. On the other hand, in the conventional intake manifold described above, although the axial direction of the intake port, which is parallel to the joining surface of the arc-shaped joint, needs to be the vibration direction for vibration welding, the joining surface formed in the chamber area is long and twisted relative to the vibration direction, which makes vibration welding difficult and may result in insufficient welding.Furthermore, since the arc-shaped joint of the cover member is close to the rectangular flange portion of the base member, there is a risk that sufficient vibration amplitude may not be ensured. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-59431 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in consideration of the above circumstances, and its object is to provide an intake manifold that can reliably hold an incorporated flame quenching element in a predetermined position while reducing the number of parts, simplifying the structure, facilitating molding using a resin material, and facilitating and ensuring joining by vibration welding. [Means for solving the problem]

[0007] The intake manifold of the present invention comprises a first molded member that defines a long surge tank and a first half of a plurality of branch pipes in the direction of a predetermined straight line, a tubular portion having an intake port, a receiving portion, and a fitting hole, in that order, centered on an axis that intersects the straight line, and a first joint, a second molded member that defines a second joint that is joined to the first molded member and includes a second half of the surge tank and the plurality of branch pipes and a second joint that is joined to the first joint, and a quenching element that is fitted into the fitting hole so as to abut against the receiving portion, and both joint surfaces of the first joint and the second joint form planes parallel to the straight line and are formed away from the fitting hole in the direction of the straight line to define a void between the first joint and the fitting hole, and the second molded member includes a restricting portion on the side opposite the receiving portion that faces the void and is adjacent to the peripheral edge of the quenching element to restrict removal of the quenching element.

[0008] In the above-mentioned intake manifold, the first joint may include a first long joint extending in a linear direction in the surge tank area, and a first surrounding joint rising from the middle of the first long joint and surrounding the fitting hole, the first surrounding joint being formed away from the fitting hole to define a void between the rising area from the first long joint and the fitting hole, and the void may include a flat surface adjacent to the regulating portion in the axial direction.

[0009] In the intake manifold described above, the receiving portion may have an annular receiving surface that is perpendicular to the axis.

[0010] In the intake manifold, the first surrounding joint may have a configuration in which the joint surface of the rising region forms a concave curved surface and includes a region that extends at a predetermined inclination angle relative to a flat surface.

[0011] In the intake manifold described above, the flat surface and the restricting portion may extend to a plane including the axis in a direction perpendicular to the axis and the straight line.

[0012] In the intake manifold, the first surrounding joint may be bent into a rectangular shape.

[0013] In the above intake manifold, the second joint may include a second elongated joint joined to the first elongated joint and a second surrounding joint joined to the first surrounding joint, and the regulating portion may include an opposing surface adjacent to and facing a semi-peripheral portion and the flat surface of the flame quenching element in an inner region of the second surrounding joint.

[0014] In the intake manifold, the flat surface may be formed so as to be flush with an end of the flame quenching element fitted in the fitting hole in the axial direction.

[0015] In the above-mentioned intake manifold, the restricting portion may have a back surface opposite to the opposing surface that forms a curved surface that is streamlined and connected to the inner wall surface of the wall portion that defines the second half of the surge tank.

[0016] In the intake manifold, the first molded member may include flange portions that are joined to the cylinder head of the engine at the ends of the branch pipes, and the mounting surfaces of the flange portions may extend parallel to a straight line.

[0017] In the intake manifold, the first surrounding joint portion may include a region that extends at a predetermined inclination angle relative to the mounting surface of the flange portion.

[0018] In the above-mentioned intake manifold, the plurality of branch pipes may be arranged in a straight line, the cylindrical portion may define a first half of the surge tank and face the wall portion on the side where the plurality of branch pipes are arranged in the axial direction, and the regulating portion may define a second half of the surge tank and face the wall portion on the side where the plurality of branch pipes are arranged in the axial direction.

[0019] In the intake manifold, the cylindrical portion may be arranged midway between the surge tank in the linear direction.

[0020] In the intake manifold, the axis of the fitting hole may be perpendicular to the straight line.

[0021] In the intake manifold, the first molded member may have a flange surface around the intake port to which a throttle device is attached. [Effects of the Invention]

[0022] The intake manifold having the above-described configuration can achieve a reduction in the number of parts, a simplified structure, easy molding using resin material, and easy and reliable joining using vibration welding, while also securely holding the incorporated flame quenching element in a predetermined position. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is an external perspective view showing an intake manifold and functional components attached thereto according to an embodiment of the present invention; [Figure 2] 1 is a perspective view showing an intake manifold according to one embodiment, as viewed from the second molded member (cover member) side. FIG. [Figure 3] 1 is a perspective view showing an intake manifold according to one embodiment, viewed from the first molded member (base member) side. [Figure 4] FIG. 2 is an exploded perspective view of the intake manifold according to the embodiment; [Figure 5] FIG. 2 is an exploded perspective view of the intake manifold according to the embodiment; [Figure 6] 1 is a perspective view showing a first molded member (base member) that constitutes an intake manifold according to one embodiment. [Figure 7]1 is a perspective cross-sectional view of a first molded member (base member) that constitutes an intake manifold according to one embodiment, cut along a plane that includes the axis of a fitting hole. [Figure 8] 2 is a cross-sectional view of a first molded member (base member) that constitutes an intake manifold according to one embodiment, cut along a plane that passes through the axis of a fitting hole. FIG. [Figure 9] FIG. 3 is a perspective view showing a second molded member (cover member) that constitutes the intake manifold according to one embodiment. [Figure 10] 3 is a perspective cross-sectional view of a second molded member (cover member) that constitutes an intake manifold according to one embodiment, cut along a plane that includes the axis of a fitting hole. FIG. [Figure 11] 4 is a cross-sectional view of a second molded member (cover member) that constitutes an intake manifold according to one embodiment, cut along a plane that passes through the axis of a fitting hole. FIG. [Figure 12] FIG. 2 is a perspective view showing a flame quenching element that constitutes an intake manifold according to one embodiment. [Figure 13] FIG. 13 is a cross-sectional view of the flame-extinguishing element shown in FIG. 12. [Figure 14] 10 is a cross-sectional view illustrating an operation of fixing a second molded member (cover member) to a first molded member (base member) by vibration welding in an intake manifold according to one embodiment. FIG. [Figure 15] 2 is a cross-sectional view of the intake manifold according to the embodiment taken along a plane including the axis of a fitting hole. FIG. [Figure 16] This is a partial cross-sectional view of an intake manifold according to one embodiment, showing the relationship between a flame quenching element fitted into a fitting hole of a first molded member (base member) and a regulating portion of a second molded member (cover member), taken along a plane including a straight line intersecting (perpendicular to) the axis of the fitting hole and viewed from inside the surge tank. [Figure 17] FIG. 1 is a perspective cross-sectional view showing the relationship between a flame quenching element fitted into a fitting hole of a first molded member (base member) and a regulating portion of a second molded member (cover member) in an intake manifold according to one embodiment, taken along a plane including the axis of the fitting hole. [Figure 18]FIG. 1 is a perspective cross-sectional view taken along a plane parallel to the axis of the fitting hole, showing the relationship between the flame quenching element fitted into the fitting hole of the first molded member (base member) and the regulating portion of the second molded member (cover member) in an intake manifold according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. The intake manifold of the present invention is molded using a resin material in a mold and is disposed between a throttle device located downstream of an intake duct in an engine intake system and a cylinder head of an engine body. The intake manifold M according to one embodiment is applied to engines mounted on, for example, personal watercraft (PWC) or outboard motors.

[0025] As shown in FIG. 1, the intake manifold M is fitted with a throttle device Tm, a fuel injection valve Fv and a fuel pipe Fp as a fuel injection system, and a sensor unit U for detecting intake pressure, intake temperature, and the like. 2 to 5, the intake manifold M includes a base member 100 as a first molded member, a cover member 200 as a second molded member, and a flame quenching element 300. With the flame quenching element 300 incorporated into the base member 100, the base member 100 and the cover member 200 are fixed together by vibration welding, and as a whole, the intake manifold M defines a surge tank St that temporarily stores intake air and a plurality of (here, four) branch pipes Bp. The surge tank St is formed to be long in the direction of the straight line X and to have a cylindrical shape with both ends closed. The branch pipes Bp are arranged in the direction of the straight line X and are formed so as to curve while extending in a direction substantially perpendicular to the straight line X.

[0026] The base member 100 is injection molded using a resin material in a mold, and as shown in Figures 4 to 6, it has a wall portion 110 as the first half of the surge tank St and multiple branch pipes Bp, a cylindrical portion 120 centered on the axis S, a first joint portion 130, a flange portion 140, a flange portion 150, and a bracket portion 160.

[0027] The wall portion 110 includes a tank wall portion 111 that defines approximately half of the surge tank St, a branch wall portion 112 that defines approximately half of the multiple branch pipes Bp, and a lattice-shaped reinforcing rib 113 formed mainly on the outer wall surface of the tank wall portion 111.

[0028] The tank wall portion 111 is formed so as to define a recessed portion that forms a substantially cylindrical inner wall surface 111a that is elongated in the direction of a straight line X that intersects with the axis S (here, perpendicular to the axis S). The branch wall portion 112 defines approximately half of each of the four branch passages, and is formed so as to curve while extending in a direction approximately perpendicular to the straight line X. The lattice-shaped reinforcing ribs 113 are formed to protrude in a lattice pattern from the outer wall surface of the tank wall 111 at a predetermined height according to the region, in order to increase the overall bending strength of the wall 110.

[0029] The cylindrical portion 120 is disposed in the middle of the surge tank St, that is, in the middle (here, approximately in the center) of the tank wall portion 111 in the direction of the straight line X, and is formed so as to open in the direction of the axis S that intersects with the straight line X. The cylindrical portion 120 has an outer contour formed in a roughly rectangular shape, and has an intake port 121, a receiving portion 122, a fitting hole 123, and a void portion 124 formed therein in that order from the outside in the direction of the axis S, and also has a flange surface 125 and four screw holes 126 on the outside around the intake port 121.

[0030] The intake port 121 is a circular opening centered on the axis S, and is a region through which the intake air that has passed through the throttle device Tm is introduced into the surge tank St. The receiving portion 122 is formed as an annular receiving surface having a circular ring shape centered on the axis S and a flat surface perpendicular to the axis S, and is configured to receive the end portion 300b of the flame quenching element 300 fitted into the fitting hole 123 in the direction of the axis S. Here, because receiving portion 122 is formed as an annular receiving surface, it can be closely fitted to end portion 330b of flame quenching element 300 in an annular shape, improving sealing performance. As a result, it is possible to reliably prevent flames entering through intake port 121 from entering between fitting hole 123 and outer peripheral surface 300a of flame quenching element 300. The fitting hole 123 is a cylindrical hole centered on the axis S, and serves to fit the flame quenching element 300 therein and position it in the radial direction while holding the flame quenching element 300 therein.

[0031] The void portion 124 is an area secured by separating the first joint portion 130 and the fitting hole 123 in the direction of the straight line X, and as shown in FIG. 7, has a flat surface 124a recessed from the first joint portion 130 in the direction of the axis S, and a side surface 124b facing the flat surface 124a in the direction of the straight line X. The flat surface 124a is located on the end side of the fitting hole 123, is a surface perpendicular to the axis S, and is formed so as to form a semicircular notch that extends to a plane P on the surface including the axis S in a direction perpendicular to the axis S and the straight line X, and that follows the peripheral portion of the fitting hole 123. The flat surface 124a is formed so as to be flush with the end 300c of the flame quenching element 300 fitted into the fitting hole 123 in the direction of the axis S. The flat surface 124a is adjacent to the restricting portion 220 formed on the cover member 200 in the direction of the axis S.

[0032] The flange surface 125 is an area where the joining portion of the throttle device Tm is joined, and is provided with an annular groove 125a into which the seal member Sr (see FIGS. 17 and 18) is fitted. The screw holes 126 are formed at the four corners of the flange surface 125 and are used to screw in screws for fastening the throttle device Tm.

[0033] As shown in Figures 6, 7, and 18, the first joint portion 130 has a rectangular cross-section convex rib 130a having a joint surface 130a1 parallel to a straight line X that intersects with the axis S of the fitting hole 123, and stepped surfaces 130b formed on both sides of the convex rib 130a. The first joint 130 has its joint surface 130a1 abutted against the joint surface 230a1 of the second joint 230 of the cover member 200 and fixed by vibration welding, and is provided with a first long joint 131, a first surrounding joint 132, and a first branch side joint 133.

[0034] The first long joint portion 131 is formed so as to extend in the direction of a straight line X on one side of the tank wall portion 111 that defines the surge tank St. As shown in Figures 6 to 8, the first surrounding joint portion 132 is interposed so as to rise from the middle of the first elongated joint portion 131 and is formed so as to bend in a rectangular shape and surround the periphery of the fitting hole 123.

[0035] Here, the first surrounding joint 132 is formed to include a rising region 132a, an inclined region 132b, a transition region 132c, and an elongated region 132d. The rising region 132a rises from the first long joint portion 131 and is a transition region where the normal to the joint surface 130a1 begins to change direction to approach the axis S, and in this region, the joint surface 130a1 is formed as a concave curved surface. The inclined region 132b is formed so that it extends in a direction perpendicular to the straight line X and faces the fitting hole 123, and the normal to the joining surface 130a1 forms a predetermined inclination angle α with respect to the direction of the axis S, i.e., forms an inclination angle α with respect to the flat surface 124a. The transition region 132c is a region where the normal to the joining surface 130a1 begins to change direction away from the direction of the axis S, and in this region, the joining surface 130a1 is formed as a convex curved surface. The elongated region 132d is a region that extends in the linear X direction, and is formed linearly, so that the amount of outward protrusion can be reduced compared to a shape that is curved outward in a convex shape, which contributes to miniaturization.

[0036] The first surrounding joint 132 having the above-mentioned configuration is formed, for example, as shown in Figure 7, on a plane P which is part of the plane including the axis S and the straight line X, at a distance L from the fitting hole 123 in a direction perpendicular to the axis S, in order to define a void portion 124 between the rising region 132a from the first long joint 131 and the fitting hole 123. That is, the first joint portion 130 has a joint surface 130a1 that is parallel to the straight line X and is formed at a distance from the fitting hole 123 in the direction of the straight line X so as to define a void portion 124 between the first joint portion 130 and the fitting hole 123. In this way, since the first joint 130 (the rising region 132a of the first surrounding joint 132) is formed away from the fitting hole 123, an area in which the void portion 124 having the width dimension L is formed can be secured compared to when the rising region 132a is formed along and adjacent to the fitting hole 123.

[0037] Furthermore, as shown in Figures 7 and 8, the first surrounding joint 132 is formed so that the joint surface 130a1 of the rising region 132a from the first long joint 131 forms a concave curved surface and the joint surface 130a1 of the inclined region 132b rises more gently than the flat surface 124a so that it forms a predetermined inclination angle α with respect to the flat surface 124a. In this way, since the first surrounding joint 132 is gentler than the flat surface 124a, vibration welding can be performed more reliably compared to when the first surrounding joint 132 has the same rising angle as the flat surface 124a.

[0038] The first branch-side joint 133 is formed so as to be curved in a region extending from the other side of the tank wall 111 that defines the surge tank St to the branch wall 112.

[0039] The flange portion 140 is provided with a mounting surface 141 and five circular holes 142 for passing bolts therethrough, so as to be joined to the cylinder head of the engine at the end of the branch pipes Bp. The mounting surface 141 is formed as a flat surface that is joined to the mounting surface of the cylinder head, and defines the open ends of the four branch pipes Bp. The mounting surface 141 extends parallel to the straight line X and serves as a reference plane Rp to which a load F is applied perpendicularly when vibration welding is performed, as shown in Fig. 8. The vibration direction of vibration welding is oriented so as to coincide with the direction of the straight line X that is parallel to the mounting surface 141.

[0040] Furthermore, the relationship between the mounting surface 141 and the first surrounding joint 132 is formed so that the joint surface 130a1 of the inclined region 132b of the first surrounding joint 132 forms a predetermined inclination angle β with respect to the mounting surface 141, as shown in Figure 8. The inclination angle β is smaller than the inclination angle γ of the flat surface 124a relative to the mounting surface 141. Therefore, compared to when the first surrounding joint 132 extends along the inclination angle γ, the load F applied during vibration welding is more reliably transmitted to the region of the first surrounding joint 132, and vibration welding can be performed more reliably.

[0041] The flange portion 150 is to which the sensor unit U is attached, and as shown in FIG. 6, is formed in the area of ​​the tank wall portion 111 and has a joining surface 151, a circular hole 152, and two screw holes 153. The bracket portion 160 is joined and fixed to a part of the engine, and as shown in Figures 2, 3, and 5, is formed to extend from the tank wall portion 111 and has a circular hole 161 through which a bolt is passed.

[0042] The cover member 200 is injection molded using a resin material in a mold, and as shown in Figures 4, 5, and 9, it has a wall portion 210 as the second half of the surge tank St and multiple branch pipes Bp, a regulating portion 220, a second joint portion 230, a boss portion 240, an attachment portion 250, and a bracket portion 260.

[0043] The wall portion 210 includes a tank wall portion 211 that defines approximately half of the surge tank St, a branch wall portion 212 that defines approximately half of the multiple branch pipes Bp, and a lattice-shaped reinforcing rib 213 formed mainly on the outer wall surface of the tank wall portion 211.

[0044] The tank wall portion 211 is formed so as to define a recessed portion that forms a substantially cylindrical inner wall surface 211a that is elongated in the direction of a straight line X that intersects with the axis S (here, perpendicular to the axis S). The branch wall portion 212 defines approximately half of each of the four branch passages, and is formed so as to curve while extending in a direction approximately perpendicular to the straight line X. The lattice-shaped reinforcing ribs 213 are formed to protrude in a lattice pattern from the outer wall surface of the tank wall 211 at a predetermined height according to the region, in order to increase the overall bending strength of the wall 210.

[0045] As shown in FIGS. 9 to 11, the restricting portion 220 is formed in the middle of the surge tank St, that is, in the middle (here, the center) of the tank wall portion 211 in the direction of the straight line X, facing the void portion 124 of the base member 100, and facing the flat surface 124a in the direction of the axis S, and is provided with an opposing surface 221, an end surface 222, a back surface 223, and side surfaces 224 on both sides in the direction of the straight line X. The restricting portion 220 faces the cavity portion 124 on the opposite side of the base member 100 from the receiving portion 122, and is adjacent to the peripheral portion (semi-peripheral portion Sp) of the flame quenching element 300 to restrict the flame quenching element 300 from coming off in the direction of the axis S.

[0046] The opposing surface 221 is a plane perpendicular to the axis S formed in the inner region of the second surrounding joint 232 of the second joint 230, and extends to a position adjacent to the plane P in the direction perpendicular to the axis S and the line X, and is formed to form a rectangular semicircular notch adjacent to the semi-peripheral edge portion Sp of the end 300c of the flame quenching element 300 adjacent to the flat surface 124a and fitted in the fitting hole 123. Furthermore, as shown in Fig. 11, the opposing surface 221 is formed to form an inclination angle γ with respect to the reference plane Rp during vibration welding, similar to the flat surface 124a.

[0047] The end surface 222 is formed as a result of ensuring the thickness of the regulating portion 220 in order to increase the rigidity of the opposing surface 221, and is formed to form a plane adjacent to or abutting the plane P of the base member 100. Here, with respect to the opposing surface 221 and the end surface 222, "adjacent" means a state in which they face each other closely with a predetermined minute gap therebetween to facilitate joining by vibration welding. By adopting this "adjacent" configuration, vibration welding becomes easy even when there is a dimensional error or when the straight line X does not intersect the axis S perpendicularly (is not orthogonal). The end surface 222 may be adjacent to or in contact with the plane P because it has less effect on vibration welding than the opposing surface 221.

[0048] 18, the rear surface 223 is formed to form a curved surface that is streamlined and connected to the inner wall surface 211a of the tank wall portion 211. This allows the intake air that has passed through the flame quenching element 300 to be smoothly guided into the surge tank St.

[0049] That is, as shown in FIG. 18, the restricting portion 220 is arranged with respect to the void portion 124 as a recess so as to face the flat surface 124a with a small gap in the direction of the axis S, and to face the side surface 124b with a small gap in the direction of the straight line X. This minute gap allows minute vibration when vibration is applied in the linear X direction during vibration welding, preventing melting and solidification in unnecessary areas and enabling vibration welding to be performed easily and reliably.

[0050] As shown in Figures 9, 10, and 18, the second joint portion 230 has a rectangular cross-section convex rib 230a having a joint surface 230a1 parallel to a straight line X intersecting the axis S of the fitting hole 123, and concave ribs 230b formed on both sides of the convex rib 230a. The second joint portion 230 has a joint surface 230a1 abutted against the joint surface 130a1 of the first joint portion 130 of the base member 100 and fixed by vibration welding, and is provided with a second long joint portion 231, a second surrounding joint portion 232, and a second branch side joint portion 233.

[0051] The second elongated joint portion 231 corresponds to the first elongated joint portion 131, and is formed so as to extend in the direction of the straight line X on one side of the tank wall portion 211 that defines the surge tank St. The second surrounding joint 232 corresponds to the first surrounding joint 132, and as shown in Figures 9 and 10, it is formed so as to rise from the middle of the second long joint 231 and to bend in a rectangular shape to surround the regulating portion 220.

[0052] Here, the second surrounding joint 232 is formed to include a rising region 232a, an inclined region 232b, a transition region 232c, and an elongated region 232d. The rising region 232a is a transition region that rises from the second elongated joint portion 231 and where the normal to the joint surface 230a1 begins to change direction to approach the axis S, and in this region, the joint surface 230a1 is formed as a convex curved surface. The inclined region 232b is formed so that it extends in a direction perpendicular to the straight line X and faces the mating hole 123, and the normal to the mating surface 230a1 forms a predetermined inclination angle α with respect to the direction of the axis S, i.e., forms an inclination angle α with respect to the opposing surface 221, similar to the mating surface 130a1 of the inclined region 132b. The transition region 232c is a region where the normal to the joining surface 230a1 begins to change direction away from the direction of the axis S, and in this region, the joining surface 230a1 is formed as a concave curved surface. The long region 232d is a region that extends in the linear X direction, and is formed linearly, so that the amount of outward protrusion can be reduced compared to a shape that is convexly curved outward, which contributes to miniaturization.

[0053] The second joint portion 230 having the above-described configuration has a shape corresponding to the first joint portion 130. That is, the second joint portion 230 has a joint surface 230a1 that is parallel to the line X and is formed at a distance from the fitting hole 123 in the direction of the line X so as to define a void portion 124 between the first joint portion 130 and the fitting hole 123. In this way, since the second joint 230 (the rising region 232a of the second surrounding joint 232) is formed away from the fitting hole 123, a void portion 124 can be provided in the base member 100, and an opposing surface 221 can be provided that is adjacent to and faces the flat surface 124a of the void portion 124 and has a large contour that is adjacent to the semi-peripheral edge portion Sp of the flame quenching element 300.

[0054] The second branch side joint 233 corresponds to the first branch side joint 133, and is formed so as to be curved in the region extending from the other side of the tank wall 211 that defines the surge tank St to the branch wall 212.

[0055] The boss portion 240 is for fixing the fuel pipe Fp, and has three screw holes 241 in the branch wall portion 212 area. The mounting portion 250 is for mounting the fuel injection valve Fv, and is provided with a through-hole 251 that penetrates into the branch passage in the area of ​​the branch wall portion 212. The bracket portion 260 is formed as a protruding piece that protrudes in the direction of the straight line X on the tank wall portion 211, and has holes 261 for fixing various functional components.

[0056] 6, 7, and 15, in the base member 100 having the above configuration, the cylindrical portion 120 defines the first half of the surge tank St and faces the wall portion 110 (tank wall portion 111) on the side where the branch pipes Bp are arranged in the direction of the axis S. In addition, in the cover member 200, the restricting portion 220 defines the second half of the surge tank St and faces the wall portion 210 (tank wall portion 211) on the side where the branch pipes Bp are arranged in the direction of the axis S. Therefore, when molding cover member 200 using a mold, if restricting portion 220, which faces flat surface 124a in the direction of axis S of tubular portion 120, is to be molded into an annular shape, it would be difficult to mold back surface 223 into a curved surface using a slide piece or the like in the inner region. Therefore, in the above embodiment, the restricting portion is molded using a two-piece mold without using a slide piece, that is, formed as restricting portion 220 having a substantially rectangular shape with a semicircular cutout. This makes it possible to easily mold using a resin material.

[0057] The flame quenching element 300 prevents flames resulting from backfire from flowing into the surge tank St, and as shown in Figures 12 and 13, is formed in a cylindrical shape with the axis S as the center as a whole, and has an outer circumferential surface 300a, an end 300b that abuts against the receiving portion 122, and an end 300c that is flush with the flat surface 124a. As shown in FIGS. 16 and 17, the semi-peripheral edge portion Sp of the end portion 300c is a region adjacent to the opposing surface 221 of the restricting portion 220.

[0058] The flame quenching element 300 is composed of a flame blocking structure 310 and an elastic cylindrical body 320 . The flame blocking structure 310 is formed in a cylindrical shape by winding, for example, a corrugated stainless steel thin plate to define honeycomb-shaped passages. The elastic cylindrical body 320 is made of a rubber material and is formed so as to cover the outer circumferential surface and the peripheral edge regions at both ends of the fire interruption structure 310, and is provided with three annular ribs 321 on the outer circumferential surface. The annular rib 321 is formed so as to be inclined toward the end portion 300c side, and plays a role in preventing the flame quenching element 300 fitted into the fitting hole 123 from coming off due to its elastic deformation.

[0059] The flame quenching element 300 is positioned relative to the base member 100 and the cover member 200 such that the annular rib 321 is elastically deformed while the outer peripheral surface 300a is fitted into the fitting hole 123 of the base member 100 and the end portion 300b is abutted against the receiving portion 122, and the opposing surface 221 of the regulating portion 220 of the cover member 200 is adjacent to the semi-peripheral edge portion Sp of the end portion 300c.

[0060] Next, the assembly of the intake manifold M will be described. First, the base member 100 and the cover member 200, which are molded from a resin material, and the flame quenching element 300 are prepared. Then, the flame quenching element 300 is fitted into the fitting hole 123 of the base member 100. Then, as shown in FIG. 14, in a welding device having a reference surface Rp, the base member 100 is fixed so that the mounting surface 141 of the flange portion 140 is placed on the reference surface Rp. Next, the cover member 200 is brought close to the base member 100 from above, and the joint surface 230a1 of the second joint portion 230 is brought into contact with the joint surface 130a1 of the first joint portion 130.

[0061] Next, a load F is applied from above perpendicular to the reference plane Rp, and vibration is applied in the direction of a straight line X (direction perpendicular to the paper surface of FIG. 14) so ​​that the cover member 200 moves slightly relative to the base member 100. During vibration welding, all of the joining surfaces 130a1, 230a1 of the first joining portion 130 and the second joining portion 230 are formed as surfaces parallel to the line X (vibration direction), making vibration welding easy. Furthermore, the first long joining portion 131 of the first joining portion 130 and the second long joining portion 231 of the second joining portion 230 are long in the vibration direction (line X direction), making bonding by vibration welding more reliable.

[0062] In the intake manifold M fixed by the vibration welding, as shown in Figures 15 to 17, the restricting portion 220 of the cover member 200 faces the void portion 124 on the side opposite the receiving portion 122 of the base member 100 and is adjacent to the peripheral portion (semi-peripheral portion Sp) of the flame quenching element 300, thereby preventing the flame quenching element 300 from coming loose. In particular, the first joint portion 130 includes a first surrounding joint portion 132 that surrounds the fitting hole 123, and the first surrounding joint portion 132 is formed at a distance from the fitting hole 123 to define the void portion 124 between the rising region 132a and the fitting hole 123, so that the restricting portion 220 can be configured to be adjacent to the flat surface 124a of the void portion 124 and adjacent to the semi-peripheral edge portion Sp of the flame quenching element 300. Therefore, the flame quenching element 300 can be reliably restricted so as not to slip out in the direction of the axis S.

[0063] As described above, the intake manifold M having the above-described configuration includes the surge tank St and the first half (wall portion 110) of the branch pipes Bp, which are long in the direction of the straight line X, the cylindrical portion 120 having the intake port 121, the receiving portion 122, and the fitting hole 123 in this order, centered on the axis S intersecting the straight line X, and the first molded member (base member 100) that defines the first joint portion 130, and the second half (wall portion 210) of the surge tank St and the branch pipes Bp, and the second joint portion 230 that is joined to the first molded member and is joined to the first molded member. 00), and a flame quenching element 300 fitted into the fitting hole 123 so as to abut against the receiving portion 122, the first joint portion 130 and the second joint portion 230 have both joint surfaces 130a1, 230a1 that form planes parallel to the line X, and are formed at a distance from the fitting hole 123 in the direction of the line X to define a void portion 124 between the first joint portion 130 and the fitting hole 123, and the second molded member (cover member 200) includes, on the side opposite the receiving portion 122, a restricting portion 220 that faces the void portion 124 and is adjacent to the peripheral portion (semi-peripheral portion Sp) of the flame quenching element 300 to restrict slipping out of the flame quenching element 300. This allows the number of parts to be reduced, the structure to be simplified, molding to resin materials to be facilitated, and joining to be facilitated and ensured by vibration welding to be facilitated and ensured, while also allowing the incorporated flame quenching element 300 to be securely held in place.

[0064] In particular, the first joint 130 includes a first long joint 131 extending in the linear X direction in the region of the surge tank St, and a first surrounding joint 132 rising from the middle of the first long joint 131 and surrounding the fitting hole 123, and the first surrounding joint 132 is formed at a distance from the fitting hole 123 to define the void 124 between the rising region 132a from the first long joint 131 and the fitting hole 123. Therefore, a restricting portion 220 can be provided as the restricting portion, which has an opposing surface 221 adjacent to and facing the semi-peripheral edge portion Sp of the flame quenching element 300 and the flat surface 124a of the void 124, and the flame quenching element 300 can be more reliably held in place.

[0065] In the above embodiment, the cover member 200 is shown as a second molded member including the restricting portion 220 that defines an opposing surface 221 adjacent to the semi-peripheral portion Sp of the flame quenching element 300 (over an angular range of 180 degrees) as a restricting portion that is adjacent to the peripheral portion of the flame quenching element 300 on the side opposite the receiving portion 122 and restricts the flame quenching element 300 from slipping out. However, the present invention is not limited to this, and the restricting portion may be adjacent to the peripheral portion of an angular range narrower than 180 degrees.

[0066] In the above embodiment, the first surrounding joint 132 and the second surrounding joint 232 are shown as being bent into a rectangular shape as the first surrounding joint and the second surrounding joint, but this is not limited to this, and the first joint and the second joint having other shapes may be adopted as long as the joint surfaces of the first joint and the second joint are formed as surfaces in the longitudinal direction of the surge tank St and parallel to the straight line X that intersects with the axis S of the fitting hole 123, and are formed at a distance from the fitting hole 123 in the direction of the straight line X.

[0067] In the above embodiment, the relationship between the surge tank St, which is long in the direction of the straight line X, and the fitting hole 123 of the tubular portion 120, which is centered on the axis S, is such that the axis S intersects the straight line X perpendicularly (i.e., orthogonally), but this is not limited to this, and the relationship may be such that the intersecting angle deviates from orthogonal as long as vibration welding is possible.

[0068] As described above, the intake manifold of the present invention achieves a reduction in the number of parts, a simplified structure, easy molding using resin material, and easy and reliable joining using vibration welding, while also being able to securely hold the incorporated flame quenching element in a predetermined position. Therefore, it can be applied to engines such as outboard motors for jet skis and small boats, and is also useful as an intake manifold for engines of other vehicles, ships, etc. [Explanation of symbols]

[0069] M intake manifold Tm throttle device St surge tank X Longitudinal direction of surge tank Rp branch pipe S axis center 100 base member (first molding member) 110 Wall (1st half) 111 Tank wall 111a Inner wall 112 Branch wall 113 Lattice reinforcement rib 120 Cylindrical part 121 Air intake 122 Receiving portion (annular receiving surface) 123 Fitting hole 124 Vacant part 124a flat surface 124b Side 125 flange surface 126 screw holes 130 1st joint 130a1 joint surface 131 First long joint 132 1st enclosure joint 132a Rising region 132b Inclined region (region extending at a predetermined inclination angle) 132c transition region 132d Long range 133 First branch side junction α: Inclination angle of the first surrounding joint (inclined area) relative to the flat surface 140 flange 141 Mounting surface Rp Reference plane during vibration welding β Inclination angle of the first surrounding joint (inclined area) relative to the mounting surface P plane 200 Cover member (second molding member) 210 Wall (second half) 211 Tank wall 211a Inner wall surface 212 Branch wall 213 Lattice-shaped reinforcing rib 220 Regulatory Department 221 Opposite surface 222 End face 223 Back side 224 Side 230 Second joint 230a1 joint surface 231 Second long joint 232 Second enclosure joint 232a Rising region 232b Slope area 232c transition region 232d Long range 233 Second branch side junction 240 Boss 250 Mounting part 260 Bracket part 300 Anti-inflammatory elements 300a Outer surface 300b end 300c Edge (periphery) Sp semi-peripheral (peripheral) 310 Fire Breaking Structure 320 Elastic Cylinder

Claims

1. a first molded member that defines a surge tank and a first half of a plurality of branch pipes that are long in the direction of a predetermined straight line, a cylindrical portion that has an axial center that intersects with the straight line and that has an intake port, a receiving portion, and a fitting hole in that order, and a first joint; a second molding member joined to the first molding member, the second molding member defining a second joint portion joined to the surge tank, second halves of the plurality of branch pipes, and the first joint portion; a flame quenching element fitted into the fitting hole so as to abut against the receiving portion, the first joint portion and the second joint portion have joint surfaces that are parallel to the straight line and are spaced apart from the fitting hole in the direction of the straight line to define a void between the first joint portion and the fitting hole; the second molding member includes, on the opposite side to the receiving portion, a restricting portion facing the cavity portion and adjacent to the peripheral edge of the flame quenching element to restrict removal of the flame quenching element; An intake manifold characterized by:

2. the first joint portion includes a first elongated joint portion extending in the direction of the straight line in the surge tank region, and a first surrounding joint portion rising from the middle of the first elongated joint portion and surrounding the fitting hole, the first surrounding joint portion is formed at a distance from the fitting hole to define the void portion between the rising region from the first elongated joint portion and the fitting hole, The cavity portion includes a flat surface adjacent to the restricting portion in the axial direction.

2. The intake manifold according to claim 1, wherein:

3. The receiving portion forms an annular receiving surface perpendicular to the axis.

2. The intake manifold according to claim 1, wherein:

4. the first surrounding joint portion includes a region in which a joint surface of the raised region forms a concave curved surface and extends at a predetermined inclination angle with respect to the flat surface; 3. The intake manifold according to claim 2, wherein:

5. The flat surface and the restricting portion extend to a plane including the axis in a direction perpendicular to the axis and the straight line.

3. The intake manifold according to claim 2, wherein:

6. The first surrounding joint portion is bent into a rectangular shape.

3. The intake manifold according to claim 2, wherein:

7. the second joint portion includes a second elongated joint portion joined to the first elongated joint portion and a second surrounding joint portion joined to the first surrounding joint portion, The restricting portion includes an opposing surface adjacent to and opposing a semi-peripheral edge portion of the flame quenching element and the flat surface in an inner region of the second surrounding joint.

3. The intake manifold according to claim 2, wherein:

8. The flat surface is formed so as to be flush with an end of the flame quenching element fitted into the fitting hole in the direction of the axis.

3. The intake manifold according to claim 2, wherein:

9. a back surface of the restricting portion located opposite to the opposing surface forms a curved surface that is streamlined and connected to an inner wall surface of a wall portion that defines the second half of the surge tank; 2. The intake manifold according to claim 1, wherein:

10. the first molded member includes flange portions that are joined to a cylinder head of an engine at ends of the plurality of branch pipes, The mounting surface of the flange portion extends parallel to the straight line.

3. The intake manifold according to claim 2, wherein:

11. the first circumferential joint includes a region extending at a predetermined inclination angle relative to the mounting surface; 11. The intake manifold according to claim 10.

12. The plurality of branch pipes are arranged in the direction of the straight line, the cylindrical portion defines the first half of the surge tank and faces a wall portion on the side where the plurality of branch pipes are arranged in the axial direction; the restricting portion defines the second half of the surge tank and faces, in the axial direction, a wall portion on a side on which the plurality of branch pipes are arranged.

2. The intake manifold according to claim 1, wherein:

13. The cylindrical portion is disposed at a middle of the surge tank in the direction of the straight line.

13. An intake manifold according to any one of claims 1 to 12.

14. The axis of the fitting hole is perpendicular to the straight line.

14. The intake manifold of claim 13.

15. The first molded member includes a flange surface around the intake port to which a throttle device is attached.

14. The intake manifold of claim 13.

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