Intake manifold support structure

Abstract

To provide an intake manifold support structure capable of shortening a front / back length dimension of an engine, and reducing a burden of support on a front side of an intake manifold.SOLUTION: A support structure includes a cylinder head 6 and a stationary structure body 2, and supports an intake manifold 9. An axial length direction of a crank shaft core is a right / left direction, a horizontal direction orthogonal to the right / left direction is a front / back direction, and one side in the front / back direction is a front side. The intake manifold 9 comprises a synthetic resin collector part 40, and plural branch pipe parts derived to a front side from the collector part 40. An intake outlet part 9d on a front end side of a branch pipe part 9a is supported by the cylinder head 6, and the collector part 40 is supported by the stationary structure body 2, and is one right / left end side of the synthetic resin collector part 40. A throttle body 12 is mounted to a side opposite to a support side of the stationary structure body 2.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a support structure for an intake manifold, and more particularly to a support structure for an intake manifold that enables the longitudinal dimension of an engine to be shortened and reduces the load on the front side of the intake manifold. [Background technology]

[0002] Conventionally, there is an engine that includes a cylinder head, an intake manifold, and a throttle body, with the axial direction of the crank shaft being the left-right direction, the horizontal direction perpendicular to the left-right direction being the front-rear direction, and one side in the front-rear direction being the front side, the intake manifold including a collector section and a number of branch pipe sections extending from the collector section to the front side, and the intake outlet section at the front end of each branch pipe section being supported by the cylinder head (see, for example, Figure 3 of Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-110297 A Summary of the Invention [Problem to be solved by the invention]

[0004] Problem 1: The length of the engine from front to rear becomes longer. In the engine of Patent Document 1, a throttle body is attached to the rear of the collector section, and the throttle body protruding rearward from the collector section increases the front-to-rear length of the engine. <Problem 2> The burden of supporting the front of the intake manifold increases. In the engine of Patent Document 1, the intake manifold is supported on one side of the cylinder head, so that the rotational moment caused by the up and down movement of the collector portion places a large burden on the support of the front side of the intake manifold. In particular, since a comparatively heavy throttle body is attached to the rear of the collector portion, the load on the front side of the intake manifold for supporting the intake manifold is further increased by the rotational moment caused by the up and down movement of the throttle body.

[0005] An object of the present invention is to provide a support structure for an intake manifold which maintains a short longitudinal dimension of an engine and reduces the load on the front side of the intake manifold. [Means for solving the problem]

[0006] The main configuration of the present invention is as follows. As shown in FIG. 5, the support structure includes a cylinder head 6 and a fixed structure 2, and supports an intake manifold 9. As shown in FIG. 4, the axial direction of the crank shaft C is the left-right direction, as shown in FIG. 3, the horizontal direction perpendicular to the left-right direction is the front-rear direction, and one side of the front-rear direction is the front side. As shown in FIG. 5, the intake manifold 9 includes a collector portion 40 made of synthetic resin, and a plurality of branch pipe portions 9a, 9b (see FIG. 9 for the branch pipe portion 9b) extending forward from the collector portion 40. An intake outlet portion 9d on the front end side of each of the branch pipe portions 9a, 9b is supported by the cylinder head 6, and the collector portion 40 is supported by the fixed structure 2. As shown in FIG. 5, this is an intake manifold support structure characterized in that a throttle body 12 is attached to one of the left and right ends of a collector part 40 made of synthetic resin, opposite the side supported by a fixed structure 2. Effect of the Invention

[0007] The present invention has the following advantages. Effect 1: The engine front-to-rear length L is kept short. As shown in FIG. 5, the throttle body 12 is attached to one of the left and right ends of the collector portion 40, so that the longitudinal dimension L of the engine is kept short as shown in FIG. Effect 2: The burden of supporting the front side of the intake manifold 9 is reduced. As shown in FIG. 5, the collector portion 40 is supported by the fixed structure 2, and the intake manifold 9 is supported at both the front and rear ends, so that the support load on the front side of the intake manifold 9 is reduced. As shown in FIG. 5, the collector part 40 located rearward from the cylinder head 6 is made of lightweight synthetic resin, so that the rotational moment caused by the up and down movement of the collector part 40 is small, which also reduces the burden of supporting the front side of the intake manifold 9. Since the comparatively heavy throttle body 12, which is normally located behind the collector part 40, is attached to either the left or right side of the collector part 40, the rotational moment caused by the up and down movement of the throttle body 12 is smaller than when it is attached to the rear of the collector part 40, and in this respect too, the support burden on the front side of the intake manifold 9 is reduced. [Brief description of the drawings]

[0008] [Figure 1] 1 is a perspective view of a multi-purpose four-wheeled vehicle according to an embodiment of the present invention, viewed from above on the front side. [Diagram 2] FIG. 2 is an explanatory diagram of an engine and its surroundings mounted on the multi-purpose four-wheeled vehicle of FIG. 1, with FIG. 2(A) being a side view and FIG. 2(B) being a rear view. [Diagram 3] FIG. 3 is a side view of the engine of FIG. 2. [Figure 4] FIG. 3 is a rear view of the engine of FIG. 2. [Diagram 5] FIG. 2 is a perspective view of the intake manifold and its surrounding area. [Figure 6] FIG. 6 is a rear view of FIG. 5. [Figure 7] 7A and 7B are diagrams for explaining the lower support structure of the intake manifold in FIG. 5, FIG. 7A being a sectional view of the main part, and FIG. 7B being an exploded perspective view of the main part. [Figure 8] 8A and 8B are diagrams for explaining the lower support structure in FIG. 5, in which FIG. 8A is a rear view of the main part, and FIG. 8B is a perspective view of the main part. [Figure 9] FIG. 2 is a cross-sectional plan view of an intake manifold used in an engine mounted on the utility vehicle of FIG. 1. [Figure 10] FIG. 10 is a perspective view showing a longitudinal rear section of the intake manifold of FIG. 9. [Figure 11] 2 is a vertical sectional side view of an oil detection device used in an engine mounted on the multipurpose four-wheeled vehicle of FIG. 1. [Figure 12] FIG. 12 is a perspective view of the oil detection device of FIG. 11 and its surrounding area. [Figure 13] FIG. 13 is an enlarged perspective view of the oil detector of FIG. 12. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] FIGS. 1 to 13 are diagrams for explaining a multipurpose four-wheel vehicle according to an embodiment of the present invention and an engine and a transmission mounted thereon. In this embodiment, a multipurpose four-wheel vehicle equipped with an inclined four-stroke inline two-cylinder diesel engine and a CTV will be described.

[0010] FIG. 1 shows an off-road utility four-wheel vehicle V, and as shown in FIG. 2, an engine E is disposed transversely with a crankshaft 1A facing sideways. In this embodiment, as shown in FIG. 4, the axial length direction of the crank shaft C is the left-right direction, as shown in FIG. 3, the horizontal direction perpendicular to the left-right direction is the front-rear direction, the forward direction of the vehicle in the front-rear direction is the front side, and the opposite side is the rear side. As shown in Fig. 1, this multipurpose four-wheeled vehicle V includes a pair of left and right front wheels 31, 31, a pair of left and right rear wheels 32, 32, a front bonnet 33, a passenger section 34, and a rear loading platform (cargo) 35. A pair of left and right seats (passenger seats) 34A, 34A are arranged in the passenger section 34 surrounded by pipe material 34p. In Fig. 1, reference numeral 34s denotes a backrest of the seat 34A, reference numeral 36 denotes a steering handle, and reference numeral 37 denotes an opening and closing door.

[0011] 2(A) and (B) show an engine E and its surroundings mounted on a multipurpose four-wheeled vehicle V, and as shown in Fig. 2(A), the engine E and the transmission 2A are disposed behind the seat 34A and below the front of the loading platform 35. The seat 34A is configured with a seat 34b and a backrest 34s supported by a support frame 38 that is in a reclined-back position, and the engine E is disposed immediately behind the support frame 38 and in a central position slightly to the right in the left-right direction as shown in Fig. 2(B).

[0012] As shown in Fig. 2(A), engine E is mounted on a machine frame (not shown) in a position in which the piston (not shown) moves slightly backward, and a transmission 2A is disposed behind a crankcase 1 of engine E. This transmission 2A is a CVT (Continuously Variable Transmission), and a differential (differential device) 3 is provided behind it. Rear axles 4 extend from the differential 3 on the left and right sides, and as shown in Fig. 2(A), support connecting members 39 are installed to connect a bottom plate 35e of a loading platform 35 and the differential case 3A.

[0013] As shown in FIG. 2(B), the support frame portion 38 supporting the seat 34A has left and right side panels 38a, 38a and a back panel 38b between them, and as shown in FIG. 2(A), the upper portion of the back panel 38b forms a vertical frame portion 38c supporting the backrest 34s. As shown in FIG. 2(A), the cargo bed 35 has a front plate 35a, left and right side plates 35b, 35c, a rear plate (tailgate plate) 35d, and a bottom plate 35e, and is mounted directly above the engine E located at the rear of the vehicle body.

[0014] As shown in Fig. 2(A), this engine is a horizontally mounted inclined engine, and as shown in Fig. 3, when viewed in a direction parallel to the crank axis C, the piston movement axis P is tilted backward at an angle θ with respect to the vertical line, and the engine has a crankcase 1, a cylinder 5, a cylinder head 6, and a head cover 7. The overall length (front-to-rear length of the engine) L, overall height (engine height) T, and overall width (engine width) W shown in Fig. 4 of engine E are more compact than conventional engines.

[0015] As shown in Fig. 2(A), an oil pan 8 is attached below the crankcase 1, and an intake manifold 9 is attached to the rear side (intake side) of the cylinder head 6. The output of the engine E is changed in speed by a transmission 2A disposed behind the crankcase 1, and then transmitted to the left and right rear axles 4, 4 and rear wheels 32, 32 (see Fig. 1) via a differential 3. An oil inspection device equipped with an oil gauge 30 is mounted on the front side of the crankcase 1, facing diagonally upward and forward.

[0016] An intake manifold 9 shown in FIG. 9 is made of synthetic resin, and has a manifold front portion 9A having a pair of branch pipe portions 9a, 9b, and a manifold rear portion 9B following the manifold front portion 9A. As shown in FIG. 5, the front end of the manifold front portion 9A is elastically supported on the cylinder head 6 via an elastic insulator 10, and a supported portion 15 provided on the lower portion of the manifold rear portion 9B is supported on the housing 2Aa of the transmission 2A.

[0017] As shown in Fig. 5, a fuel injector 11 is provided at the top of each branch pipe 9a, 9b (see Fig. 9 for branch pipe 9b) facing downward and forward, and a throttle body 12 is attached to the right side wall 40f of the manifold rear part 9B. The intake manifold 9 has an intake inlet 9i that opens sideways on the right side of the rear part, and two intake outlets 9d at its front end (the front ends of each branch pipe 9a, 9b). As shown in FIG. 9, the throttle body 12 includes a venturi portion 12a, a throttle valve 12b, and a valve actuator 12c.

[0018] The following describes the support structure for the intake manifold 9, which is a major element of this engine, the internal structure and outer wall structure of the collector section 40 of this intake manifold 9, the engine model that uses the intake manifold 9, and the engine oil inspection device.

[0019] The support structure of the intake manifold 9 is as follows. As shown in FIG. 5, the support structure for the intake manifold 9 includes a cylinder head 6 and a fixed structure 2, and supports the intake manifold 9. As described above, the axial length direction of the crank shaft C shown in FIG. 4 is the left-right direction, and as shown in FIG. 3, the horizontal direction perpendicular to the left-right direction is the front-rear direction, and one side of the front-rear direction (the side toward which the vehicle moves forward) is the front side. As shown in FIG. 5, the intake manifold 9 includes a collector portion 40 made of synthetic resin, and a plurality of branch pipe portions 9a, 9b (see FIG. 9 for branch pipe portion 9b) extending forward from the collector portion 40. The intake outlet portions 9d at the front ends of the branch pipe portions 9a, 9b are supported by the cylinder head 6, and the collector portion 40 is supported by the fixed structure 2. As shown in FIG. 5, the throttle body 12 is attached to one of the left and right ends of the collector portion 40 made of synthetic resin, on the side opposite to the side supported by the fixed structure 2.

[0020] As shown in FIG. 5, according to this support structure for the intake manifold 9, the throttle body 12 is attached to one of the left and right ends of the collector portion 40, so that the longitudinal dimension L of the engine is kept short, as shown in FIG. As shown in FIG. 5, the collector portion 40 is supported by the fixed structure 2, and the intake manifold 9 is supported at both the front and rear ends, so that the support load on the front side of the intake manifold 9 is reduced. As shown in FIG. 5, the collector part 40 located rearward from the cylinder head 6 is made of lightweight synthetic resin, so that the rotational moment caused by the up and down movement of the collector part 40 is small, which also reduces the burden of supporting the front side of the intake manifold 9. Since the comparatively heavy throttle body 12, which is normally located behind the collector part 40, is attached to either the left or right side of the collector part 40, the rotational moment caused by the up and down movement of the throttle body 12 is smaller than when it is attached to the rear of the collector part 40, and in this respect too, the support burden on the front side of the intake manifold 9 is reduced.

[0021] In addition to the above-described support structure, in the support structure of this intake manifold 9, as shown in FIG. 7(B), the collector portion 40 is elastically supported on the fixed structure 2 via a pair of connecting plates 17, 17 formed in the same isosceles triangle. The isosceles triangles of this invention include not only geometric isosceles triangles whose three vertices are edges, but also shapes similar to geometric isosceles triangles (hereinafter referred to as "similar isosceles triangles") whose three vertices are arc-shaped or have other shapes and whose two included angles between the two sides are equal. As shown in FIG. 5, the collector part 40 is elastically supported on the fixed structure via a pair of connecting plates 17, 17, and the intake manifold 9 is supported on both the front and rear sides, thereby reducing the support load on the front side of the intake manifold 9. In addition, since the collector portion 40 is elastically supported by the fixed structure 2, the vertical vibration of the collector portion 40 and the relatively heavy throttle body 12 is reduced, and the support load on the front side of the intake manifold 9 is reduced.

[0022] As shown in FIG. 5, in the support structure of this intake manifold 9, the throttle body 12 is supported on a fixed structure 12B via an intake piping 14, and a flexible pipe 14A having elasticity is used for the intake piping 14. Although the vehicle body frame is used as the fixed structure 12B, the fixed structure 12B may be a device mounted on the vehicle.

[0023] As shown in FIG. 5, with this support structure for the intake manifold 9, the rear side of the intake manifold 9 is elastically supported via the flexible pipe 14A, thereby reducing the vertical vibration of the throttle body 12 and further reducing the burden of supporting the front side of the intake manifold 9.

[0024] As shown in Figure 3, in the support structure for this intake manifold 9, a fixed structure 2 is disposed below the intake manifold 9, the collector portion 40 has a supported portion 15 at its lower portion, and the fixed structure 2 has a support portion 16 protruding upward from its upper side, and the supported portion 15 of the collector portion 40 is supported by the support portion 16 of the fixed structure 2. As shown in FIG. 3, according to this support structure for the intake manifold 9, the space below the intake manifold 9 can be effectively used as an arrangement space for the fixed structure 2.

[0025] As shown in FIG. 8(A), in the support structure of this intake manifold 9, the fixed structure 2 has a divided mating surface 28A of the housing 2Aa, and the support portion 16 of the fixed structure 2 protrudes from the housing 2Aa along the divided mating surface 28A. According to the support structure of the intake manifold 9 shown in FIG. 8(A), the support portion 16 can be formed at the same time as the housing 2Aa is molded using a metal mold. This fixed structure 2 is a transmission 2A, whose housing 2Aa is divided into a left housing portion 27 and a right housing portion 28 which are joined at a division mating surface 28A, and the support portion 16 is formed in the right housing portion 28.

[0026] As shown in FIG. 8(A), in the support structure of this intake manifold 9, the fixed structure 2 has a support portion 16, and this support portion 16 and the supported portion 15 of the collector portion 40 are connected via an elastic connector S. As shown in Figure 8 (B), according to this support structure of the intake manifold 9, the presence of the elastic connecting body S makes the supporting part 16 and the supported part 15 shorter and increases their rigidity compared to when the supported part 15 is directly connected to the supporting part 16, thereby improving the durability of the supporting part 16 and the supported part 15.

[0027] As shown in FIG. 7(A), in the support structure of this intake manifold 9, the elastic connecting body S includes a pair of connecting plates 17·17 that sandwich the supporting part 16 and the supported part 15 from both sides, a pair of fasteners 18·19 that attach the pair of connecting plates 17·17 to the supporting part 16 and the supported part 15, and a knock pin 20 that is attached to either the supporting part 16 or the supported part 15. The knock pin 20 is inserted through the pair of connecting plates 17·17, and an elastic collar 23·23 is attached to at least one of the fasteners 18 of the pair of fasteners 18·19. The supported part 15 of the collector part 40 is elastically supported on the supporting part 16 of the fixed structure 2 via the elastic collar 23·23 positioned by the pair of fasteners 18·19 and the knock pin 20. According to this support structure for the intake manifold 9, the intake manifold 9 can be elastically supported on the fixed structure 2 by the elastic connector S having a simple structure.

[0028] As shown in FIG. 7(B), in the support structure for the intake manifold 9, the pair of connecting plates 17, 17 each include a knock pin insertion hole 20a through which a knock pin 20 is inserted, and fastener insertion holes 18a, 19a through which a pair of fasteners 18, 19 (see FIG. 7(A) for the fastener 18) are inserted, and the pair of fastener insertion holes 18a, 19a are configured to be line-symmetrical with respect to a virtual axis of symmetry 20b that radially intersects the knock pin insertion hole 20a, with the pair of fastener insertion holes 18a, 19a being arranged at line-symmetrical positions. The pair of connecting plates 17·17 are shaped like an isosceles triangle with three circular arc vertices, and are made of metal plates. As shown in FIG. 7(B), according to this support structure for the intake manifold 9, the assembled shape of the connecting plates 17 / 17 is consistent whether they are facing front or back, and the relative positions of the knock pin insertion hole 20a and the pair of fastener insertion holes 18a / 19a are consistent, so there is no need to check whether the connecting plates 17 / 17 are facing front or back, and the installation work of the connecting plates 17 / 17 is facilitated.

[0029] As shown in FIG. 7(B), a knock pin insertion hole 20a is provided in the apex corner 17a of each connecting plate 17, and a pair of fastener insertion holes 18a, 19a are provided in a pair of base corners 17b, 17b which are at different angles from the apex corner 17a. As shown in FIG. 7(B), with this support structure for the intake manifold 9, when installing the connecting plates 17·17, the top corner 17a where the knock pin insertion hole 20a is provided and the bottom corners 17b·17b where the fastener insertion holes 18a·19a are provided can be distinguished from each other simply by checking the difference in the angles of the corners, and the installation posture of the connecting plates 17·17 can be confirmed, making the installation of the connecting plates 17·17 even easier.

[0030] As shown in Fig. 7(A), the boss portion 16A of the support portion 16 sandwiched between the left and right connecting plates 17·17 and each of the connecting plates 17·17 are rigidly fastened and fixed by a first bolt 25 and a first nut 26 constituting a first fastener 19 inserted into a boss hole 16a formed in the boss portion 16A and fastener insertion holes 19a·19a of each of the connecting plates 17·17. The posture of each connecting plate 17·17 around the first bolt 25 is determined by the fitting of both ends 20p·20p of a knock pin 20 protruding to the left and right from the support portion 16 with the knock pin insertion holes 20a·20a of each connecting plate 17·17 shown in Fig. 7(B).

[0031] 7(A), elastic collars 23 made of a flexible material such as rubber are fitted into the through hole 15a of the supported portion 15 on both the left and right sides, and a metal spacer 24 is fitted into the boss portions 23b of the elastic collars 23. Then, with the spacer 24 sandwiched between the left and right connecting plates 17, the second fastener 18 is tightened and fixed by a second bolt 21 and a second nut 22 which are passed through the fastener insertion holes 18a of the connecting plates 17 and the inner hole 24a of the spacer 24.

[0032] As shown in Fig. 7(A), the elastic collar 23 has a cylindrical boss portion 23b and a disk-shaped flange portion 23a, and has an L-shaped cross section, and when fastened by the second bolt 21 and the second nut 22, the left and right flange portions 23a are slightly compressed left and right. Therefore, the intake manifold 9 is in a state where it is elastically supported by the housing 2Aa of the transmission 2A. Note that the connecting plates 17, which are rigidly fixed to the supported portion 15, may be attached to the supporting portion 16 in a resiliently supported state.

[0033] Next, the internal structure of the collector portion 40 of the intake manifold 9 will be described. As shown in FIG. 9, the intake manifold 9 includes a collector portion 40 and a plurality of branch pipe portions 9a and 9b extending from the collector portion 40. The collector portion 40 has a longitudinal direction which corresponds to the left-right direction, and a throttle communication port 41 is opened at one of the left and right ends of the collector portion 40 . The branch pipes 9a and 9b have tank side openings 9aa and 9ba facing the internal space 40S of the collector section 40. As shown in FIG. 9, the collector portion 40 has a boundary wall 45 at the boundary between the throttle communication port 41 and the tank side opening 9ba of the branch pipe portion 9b close to the throttle communication port 41, and this boundary wall 45 has an inward protrusion 45a that protrudes toward the internal space 40S of the collector portion 40.

[0034] As shown in FIG. 5, according to this collector portion 40, a throttle communication port 41 is opened at one of the left and right ends of the collector portion 40, and the throttle body 12 is connected to this port, so that the front-to-rear length L of the engine is kept short, as shown in FIG. Furthermore, the amount of intake air for each cylinder is equalized according to the internal structure of the collector portion 40. The reason for this is presumed to be as follows. The intake resistance of the inward protrusion 45a shown in Figure 9 interferes with the supply of intake air to the cylinders close to the throttle communication port 41, which tend to have a large intake volume, and the intake air not used to supply to these cylinders is supplied to distant cylinders, which tend to have a small intake volume, thereby equalizing the intake volume of each cylinder.

[0035] As shown in FIG. 9, in the internal structure of this collector section 40, the inner surface of the inward protrusion 45a is formed as an inwardly protruding arc surface 45aa. According to the internal structure of collector portion 40, turbulence is unlikely to occur in the intake air due to inwardly protruding arcuate surface 45aa shown in FIG. 9, and the supply of intake air to each cylinder is unlikely to be hindered by turbulence.

[0036] Next, the outer wall structure of the collector section 40 will be described. As shown in FIG. 9, in the outer wall structure of this collector portion 40, of the left and right end walls of the collector portion 40, the anti-throttle side end wall 40e opposite the end wall having the throttle communication port 41 protrudes toward the anti-throttle side further than the internal passage 9ac of the anti-throttle side branch pipe portion 9a. According to this outer wall structure of collector part 40, at the anti-throttle side end wall 40e shown in FIG. 9, the internal space 40S of collector part 40 is expanded further toward the anti-throttle side than the internal passage 9ac of branch pipe part 9a on the anti-throttle side, promoting the intake of air into cylinders farther from the throttle communication port 41 and making the intake amounts of each cylinder more uniform.

[0037] As shown in FIG. 9, in the outer wall structure of the collector portion 40, an end wall 40c on the opposite side to the cylinder head of the collector portion 40 protrudes beyond the throttle communication port 41 toward the opposite side to the cylinder head.

[0038] According to this outer wall structure of the collector part 40, the internal space 40S of the collector part 40 is expanded toward the opposite cylinder head side more than the throttle communication port 41 at the end wall 40c on the opposite cylinder head side shown in FIG. 9, promoting the intake of air into the cylinders farthest from the throttle communication port 41 and making the intake amount of each cylinder more uniform. In FIG. 10, reference numeral 40a denotes a ceiling wall of the collector portion 40, and reference numeral 40b denotes a bottom wall.

[0039] Next, engine models using an intake manifold will be described. As shown in FIG. 9, this intake manifold 9 is an intake manifold in which a pair of left and right branch pipes 9a and 9b are led out from a collector portion 40, and is used in a two-cylinder engine. When this intake manifold 9 is used in a two-cylinder engine in which the difference in the intake paths from the throttle communication port 41 is large, the effect of equalizing the intake amounts of each cylinder becomes apparent.

[0040] A pair of branch pipes 9a and 9b shown in Fig. 5 (see Fig. 9 for branch pipe 9b) extend straight and parallel to each other from the collector portion 40 toward the cylinder head 6. As shown in Fig. 9, peripheral walls 9ab and 9bb of tank side openings 9aa and 9ba of the pair of branch pipes 9a and 9b each protrude from the cylinder head side end wall 40d of the collector portion 40 toward the internal space 40S of the collector portion 40.

[0041] This intake manifold 9 is used in a four-stroke in-line two-cylinder engine in which the crank pin angle of the crankshaft 1A shown in FIG. 4 is 180° and the phase difference between the intake stroke of the second cylinder on the throttle communication port 41 side shown in FIG. 9 and the intake stroke of the first cylinder which follows this intake stroke is 180° in crank angle. When used with this engine model, the first cylinder, whose intake stroke begins with a relatively small phase difference of 180 degrees after the start of the intake stroke of the second cylinder, is prone to insufficient intake, and when this intake manifold is used with the above engine, the effect of equalizing the intake amount of each cylinder becomes even more pronounced.

[0042] Next, the engine oil detection device will be described. The engine 2 shown in FIG. 2(A) is equipped with an oil gauge, which, as shown in FIG. 11, includes an oil gauge 30, a guide pipe 53 that guides the oil gauge 30 to the engine oil EO in the oil pan 8, and a support pipe 52 that supports the guide pipe 53 on the crankcase 1. The support pipe 52 is inserted into a support pipe insertion hole 51 of the crankcase 1 . The lower end of the guide pipe 53 has an inner fitting portion 53A which is fitted and fixed into the upper end of the support pipe 52. A protrusion 54 is provided around the inner circumference of the inner fitting portion 53A. The guide pipe 53 has a curved portion 53c in the middle. As shown in FIG. 11, the curved portion 53c causes the upper portion of the guide pipe 53 to incline upward and away from the crankcase 1, and the oil gauge 30 inserted into the guide pipe 53 is configured to come into contact with the curved portion 53c, the protrusion 54, and the inner circumferential surfaces of the support pipe 52.

[0043] This engine oil gauge device is suitable when the only access route to the oil gauge is diagonally above the guide pipe 53 due to the engine installation environment, and can be accessed from diagonally above the guide pipe 53, allowing the oil gauge 30 to be inserted and removed along the diagonally upward direction of the guide pipe 53. Furthermore, as shown in FIG. 11, with this engine oil testing device, the oil gauge 30 inserted into the guide pipe 53 comes into contact with three points: the curved portion 53c, the protrusion 54, and the inner surface of the support pipe 52. This creates a large resistance in the direction in which the oil gauge 30 is pulled out, and prevents the oil gauge 30 from coming out of the guide pipe 53 due to inertial force when the vehicle on which the engine is mounted is braked.

[0044] As shown in FIG. 11, in this engine oil detection device, the lower end of the support pipe 52 is provided with a tapered section 52D whose inner diameter gradually decreases downward. As shown in Figure 11, in this engine oil inspection device, the oil gauge 30 which penetrates the support pipe 52 is received inside the tapered portion 52D at the lower end of the support pipe 52, thereby suppressing the oscillation of the oil gauge 30 which protrudes from the support pipe 52 toward the oil pan 8.

[0045] As shown in FIG. 11, in this engine oil inspection device, the inner fitting portion 53A of the guide pipe 53 is expanded, and the oil gauge 30 inserted into the guide pipe 53 is configured to contact the non-expanded portion 53Aa of the guide pipe 53 adjacent to the upper side of the expanded inner fitting portion 53A. As shown in FIG. 11, in this engine oil inspection device, the oil gauge 30 also comes into contact with the non-expanded diameter portion 53Aa of the guide pipe 53 adjacent to the internally fitted portion 53A, so that the resistance in the direction in which the oil gauge 30 is pulled out becomes even greater.

[0046] As shown in FIG. 11, in the engine oil detection device, a concave groove 54a is provided around the outer periphery of the protrusion 54, and an O-ring 54b is fitted into this concave groove 54a, and the pipe gap 54c between the fitted portion 53A of the guide pipe 53 and the support pipe 52 is sealed by this O-ring 54b. According to this engine oil inspection device, the sealing performance of the pipe gap 54c is improved.

[0047] As shown in FIG. 11, in this engine oil detection device, an upper end portion 52a of a support pipe 52 is spaced upward from an upper edge portion 51a of a support pipe insertion hole 51 of a crankcase 1 at a distance d.

[0048] As shown in FIG. 11, with this engine oil inspection device, foreign matter such as dust that has accumulated around the support pipe insertion hole 51 does not enter the pipe gap 54c from the upper end 52a of the support pipe 52, which is spaced upward, so damage to the O-ring 54b due to foreign matter getting caught in it is prevented.

[0049] 11, guide pipe 53 made of metal or the like has an internal fitting portion 53A that is fitted into enlarged diameter portion 52A of support pipe 52, an upper end portion (base end portion) 53B into which plug portion 30A made of an elastic material fitted into the upper end portion of oil gauge 30 is fitted, and an intermediate portion 53C between internal fitting portion 53A and upper end portion 53B. Intermediate portion 53C, which is the original diameter of the pipe material, has a curved portion 53c formed by bending the intermediate portion in the longitudinal direction at an angle x (e.g., 35 to 45 degrees).

[0050] As shown in Fig. 11, the upper end 53B has an expanded diameter opening 53b where the original pipe material is expanded in diameter and the plug portion 30A is tightly fitted inside. The upper side (base end side) of the expanded diameter opening 53b is formed as a groove portion 58, and the lower side (tip end side) is formed as a gradually changing diameter portion 59 where the diameter gradually increases from the original diameter toward the expanded diameter opening 53b. The expanded diameter opening 53b is set to a diameter such that the plug portion 30A, which is pushed into its inner circumferential surface by the operation of the fingers, does not easily come out.

[0051] 11, the oil gauge 30 has a grip portion 30B at the upper part (base end) made of a metal bar, a gauge portion 30C which is integrally connected to the lower part of the grip portion 30B by a rivet 60, and a plug portion 30A which is fitted into the grip portion 30B. The plug portion 30A has a stepped tubular portion 30a which is lightly press-fitted into the enlarged diameter opening 53b, and a large diameter stop portion 30b which is received by the groove portion 58. The upper end portion of the grip portion 30B is rounded at approximately 270 degrees to form a hook portion 30f through which a finger can pass.

[0052] As shown in FIG. 11, the gauge section 30C is a long, thin, flat-sectioned plate made of a flexible material (e.g., spring steel), with first and second torsional sections 61, 62 formed at the lower end and twisted 180 degrees at the upper end, respectively. It should be noted that a line N shown in FIG. 11 indicates the upper limit of the engine oil EO remaining in the oil pan 8 and the lower part of the crankcase 1.

[0053] 11, a bracket 64 made of a metal plate is attached by welding or other means to a location between the inner fitting portion 53A and the curved portion 53c of the guide pipe 53. The bracket 64 has a hole (not shown) through which it can be fastened to an attachment boss 50A formed on the crankcase 1 with a bolt 65. The attachment boss 50A was a boss for attaching an oil gauge to the crankcase of the engine before the improvement, and in this engine it is effectively used as a boss for screwing in the bolt 65. FIG. 12 shows a perspective view of the oil gauge of FIG. 11 and its surrounding area, and FIG. 13 shows an enlarged perspective view of the oil gauge of FIG.

[0054] In the multi-purpose four-wheel vehicle V shown in FIG. 1, as shown in FIG. 2(A), the engine E is disposed behind the seat 34A and under the front part of the cargo bed 35, the oil detection device is disposed in front of the crankcase 1, and the upper part of the guide pipe 53 extends obliquely toward the upper front. As shown in Fig. 3, grip portion 30B at the upper end of oil gauge 30 is located behind back panel 38b which is a support member of seat 34A (see Figs. 2(A)(B)), and an openable (or removable) lid 66 is provided on back panel 38b, and by opening (or removing) lid 66, the oil detector can be accessed from diagonally above and forward of guide pipe 53, and engine oil level can be checked by inserting and removing oil gauge 30 along the diagonally upward and forward direction of guide pipe 53. Reference numeral 67 in Fig. 3 denotes an oil filter. [Explanation of symbols]

[0055] 2...fixed structure, 2Aa...housing, 6...cylinder head, 9...intake manifold, 9a, 9b...branch pipe portion, 9d...intake outlet portion, 12...throttle body, 12B...fixed structure, C...crankshaft, 14...intake piping, 14A...flexible pipe, 15...supported portion, 16...support portion, 28A...split mating surface, 40...collector portion.

Claims

1. A support structure including a cylinder head 6 and a fixed structure 2, and supporting an intake manifold 9, The axial direction of the crank shaft C is defined as the left-right direction, the horizontal direction perpendicular to the left-right direction is defined as the front-rear direction, and one side of the front-rear direction is defined as the front side. The intake manifold 9 includes a collector portion 40 made of synthetic resin, and a plurality of branch pipe portions 9a and 9b extending forward from the collector portion 40. An intake outlet portion 9d at the front end of each of the branch pipe portions 9a and 9b is supported by the cylinder head 6. The collector portion 40 is supported by the fixed structure 2. The support structure for an intake manifold is characterized in that a throttle body is attached to one of the left and right ends of a collector portion made of synthetic resin, the end opposite to the end supported by a fixed structure.

2. 2. The intake manifold support device according to claim 1, An intake manifold support structure, characterized in that a throttle body (12) is supported on a fixed structure (12B) via an intake piping (14), and a flexible pipe (14A) having elasticity is used for the intake piping (14).

3. The support structure for an intake manifold according to claim 1 or 2, A fixed structure 2 is disposed below the intake manifold 9, A support structure for an intake manifold, characterized in that the collector portion (40) has a supported portion (15) at its lower portion, the fixed structure (2) has a support portion (16) protruding upward from its upper side, and the supported portion (15) of the collector portion (40) is supported by the support portion (16) of the fixed structure (2).

4. 4. The support structure for an intake manifold according to claim 3, An intake manifold support structure, characterized in that a fixed structure (2) has a division mating surface (28A) of a housing (2Aa), and a support portion (16) of the fixed structure (2) protrudes from the housing (2Aa) along the division mating surface (28A).

Images