Intake manifold
The intake manifold design addresses the issue of long engine dimension and uneven air volume by using inward projections to redirect intake air, resulting in a compact engine with uniform air distribution.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- KUBOTA CORP
- Filing Date
- 2023-06-29
- Publication Date
- 2026-07-02
Smart Images
Figure 0007883974000001 
Figure 0007883974000002 
Figure 0007883974000003
Abstract
Description
Technical Field
[0001] The present invention relates to an intake manifold, and more particularly to an intake manifold in which the longitudinal dimension of the engine is shortened and the intake air volume of each cylinder is equalized.
Background Art
[0002] Conventionally, there is an intake manifold including a collector portion and a plurality of branch pipe portions led out from the collector portion, with the longitudinal direction of the collector portion being the left-right direction and a throttle communication port being opened at the center position in the left-right direction of the collector portion (see, for example, FIG. 3 of Patent Document 1).
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] 《Problem 1》 The longitudinal dimension of the engine becomes long. In the intake manifold of Patent Document 1, the longitudinal dimension of the engine becomes long due to the throttle body protruding from the collector portion. 《Problem 2》 The intake air volume of each cylinder may become uneven. To solve Problem 1, in the engine of Patent Document 1, it is conceivable to open the throttle communication port at one end in the left-right direction of the collector portion. However, in this case, the ventilation paths from the throttle communication port to each branch pipe portion are different, and the intake air volume to the cylinders close to the throttle communication port tends to be large, while the intake air volume to the distant cylinders tends to be small, and the intake air volume of each cylinder may become uneven.
[0005] An object of the present invention is to provide an intake manifold in which the longitudinal dimension of the engine is shortened and the intake air volume of each cylinder is equalized.
Means for Solving the Problems
[0006] The main components of the present invention are as follows: As illustrated in Figure 9, it comprises a collector section 40 and a plurality of branch pipe sections 9a and 9b led out from the collector section 40. With the longitudinal direction of the collector section 40 being the left-right direction, a throttle communication port 41 is opened on one end of the collector section 40, The branch pipe sections 9a and 9b are equipped with tank-side openings 9aa and 9ba facing the internal space 40S of the collector section 40. As illustrated in Figure 9, the collector section 40 is provided with a boundary wall 45 at the boundary between the throttle communication port 41 and the tank-side opening 9ba of the branch pipe section 9b near the throttle communication port 41, and this boundary wall 45 is The inside Protruding toward the internal space 40S of the collector section 40 Formed by an inwardly projecting arcuate surface 45aa Inward-facing projection 45a Conversely, there is an outward-facing projection that protrudes outward from the internal space 40S of the collector section 40. Equipped with Furthermore, the outward-facing projection is provided at the portion near the throttle communication port 41, and the inward-facing projection 45a is provided at the portion of the branch pipe portion 9b near the tank-side opening 9ba, which is close to the throttle communication port 41. The peripheral walls 9ab and 9bb of the tank-side openings 9aa and 9ba of the branch pipe sections 9a and 9b protrude from the cylinder head-side end wall 40d of the collector section 40 toward the internal space 40S of the collector section 40. An intake manifold characterized by the following: [Effects of the Invention]
[0007] The present invention provides the following effects: Effect 1: The engine's front-to-rear length (L) is shortened. As illustrated in Figure 5, a throttle communication port 41 is opened on one end of the collector section 40, and the throttle body 12 is connected thereto, so the front-to-rear length L of the engine is shortened, as illustrated in Figure 3. Effect 2: The intake volume of each cylinder is equalized. The intake volume for each cylinder is equalized. The reason for this is presumed to be as follows: As illustrated in Figure 9, the intake resistance of the inwardly protruding portion 45a obstructs the supply of intake air to the cylinders closer to the throttle communication port 41, where the intake air volume tends to be high. The intake air that is not used to supply these cylinders is then supplied to the distant cylinders, where the intake air volume tends to be low, thus equalizing the intake air volume to each cylinder. [Brief explanation of the drawing]
[0008] [Figure 1] This is a perspective view of the multi-purpose four-wheeler according to an embodiment of the present invention, seen from the front upper side. [Figure 2] This is an explanatory diagram of the engine mounted on the multi-purpose four-wheeler of FIG. 1 and its peripheral parts. FIG. 2(A) is a side view, and FIG. 2(B) is a rear view. [Figure 3] This is a side view of the engine of FIG. 2. [Figure 4] This is a rear view of the engine of FIG. 2. [Figure 5] This is a perspective view of the intake manifold and its peripheral parts. [Figure 6] This is a rear view of FIG. 5. [Figure 7] This is a diagram for explaining the lower support structure of the intake manifold of FIG. 5. FIG. 7(A) is a cross-sectional view of the main part, and FIG. 7(B) is an exploded perspective view of the main part. [Figure 8] This is a diagram for explaining the lower support structure of FIG. 5. FIG. 8(A) is a rear view of the main part, and FIG. 8(B) is a perspective view of the main part. [Figure 9] This is a cross-sectional plan view of the intake manifold used in the engine mounted on the multi-purpose four-wheeler of FIG. 1. [Figure 10] This is a perspective view showing the longitudinal rear of the intake manifold of FIG. 9. [Figure 11] This is a longitudinal side view of the oil inspection device used in the engine mounted on the multi-purpose four-wheeler of FIG. 1. [Figure 12] This is a perspective view of the oil inspection device of FIG. 11 and its peripheral parts. [Figure 13] This is an enlarged perspective view of the oil inspection device of FIG. 12.
Embodiments for Carrying Out the Invention
[0009] FIGS. 1 to 13 are diagrams for explaining the multi-purpose four-wheeler according to an embodiment of the present invention and the engine and transmission mounted thereon. In this embodiment, a multi-purpose four-wheeler equipped with an inclined 4-cycle in-line 2-cylinder diesel engine and a CTV will be described.
[0010] An all-purpose four-wheeler V for offloading is shown in Fig. 1. As shown in Fig. 2, the engine E is arranged horizontally with the crankshaft 1A in a lateral position. In this embodiment, as shown in Fig. 4, the axial length direction of the crankshaft center C is defined as the left-right direction, and as shown in Fig. 3, the horizontal direction orthogonal to the left-right direction is defined as the front-back direction. The vehicle forward side in the front-back direction is defined as the front side, and the opposite side is defined as the rear side for explanation. As shown in Fig. 1, this all-purpose four-wheeler 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 compartment 34, and a rear cargo bed 35. In the passenger compartment 34 surrounded by the pipe material 34p, a pair of left and right seats (riding seats) 34A·34A are arranged. The reference numeral 34s in Fig. 1 is the backrest of the seat 34A, the reference numeral 36 is the steering wheel, and the reference numeral 37 is the opening and closing door.
[0011] Figs. 2(A) and (B) show the engine E mounted on the all-purpose four-wheeler V and its peripheral parts. As shown in Fig. 2(A), the engine E and the transmission 2A are arranged behind the seat 34A and below the front part of the cargo bed 35. The seat 34A is composed of a seat base 34b and a backrest 34s, which are supported by a support frame portion 38 in a rearwardly tilted diagonal posture. Immediately behind the support frame portion 38 and at a position in the central part that is slightly to the right in the left-right direction as shown in Fig. 2(B), the engine E is provided.
[0012] As shown in Fig. 2(A), the engine E is mounted on the body frame (not shown) in a posture where the moving direction of the piston (not shown) is slightly rearwardly tilted. The transmission 2A is arranged behind the crankcase 1 of the engine E. This transmission 2A is a CVT (Continuously Variable Transmission), and a differential 3 is provided on its rear side. Rear axles 4 extend left and right from the differential 3, and as shown in Fig. 2(A), a support connecting member 39 that connects the bottom plate 35e of the cargo bed 35 and the differential case 3A is installed.
[0013] As shown in Figure 2(B), the support frame 38 that supports the seat 34A has left and right side plates 38a, 38a and a back plate 38b between them, and as shown in Figure 2(A), the upper part of the back plate 38b is a vertical frame 38c that supports the backrest 34s. As shown in Figure 2(A), the cargo bed 35 comprises a front plate 35a, left and right side plates 35b and 35c, a rear plate (side panel) 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 Figure 2(A), this engine is a transversely mounted, inclined engine. As shown in Figure 3, when viewed parallel to the crank axis C, the piston movement axis P is mounted at an angle θ to the rear with respect to the perpendicular. It comprises a crankcase 1, a cylinder 5, a cylinder head 6, and a head cover 7. The overall length (front-to-back length) L and overall height (engine height) T of the engine E shown in Figure 3, and the overall width (engine width) W shown in Figure 4, are more compact compared to conventional engines.
[0015] As shown in Figure 2(A), an oil pan 8 is mounted below the crankcase 1, and an intake manifold 9 is mounted on the rear (intake side) of the cylinder head 6. The output of the engine E is shifted by a transmission 2A located behind the crankcase 1, and then transmitted through the differential 3 to the left and right rear axles 4,4 and rear wheels 32,32 (see Figure 1). An oil inspection device equipped with an oil gauge 30 is mounted on the front of the crankcase 1, facing diagonally upward and forward.
[0016] The intake manifold 9 shown in Figure 9 is made of synthetic resin and has a front manifold 9A with a pair of branch pipe sections 9a and 9b, and a rear manifold 9B that follows the front manifold 9A. As shown in Figure 5, the front end of the front part 9A of the manifold is elastically supported by the cylinder head 6 via an elastic insulator 10, and the supported part 15 located at the bottom of the rear part 9B of the manifold is supported by the housing 2Aa of the transmission 2A.
[0017] As shown in Figure 5, fuel injectors 11 are mounted on the upper part of each branch pipe section 9a, 9b (see Figure 9 for branch pipe section 9b) in a forward-downward orientation, and a throttle body 12 is attached to the right side wall 40f of the rear part 9B of the manifold. The intake manifold 9 has an intake inlet 9i that opens laterally on the right side of its rear, and two intake outlets 9d at its front end (the front end of each branch pipe section 9a, 9b). As shown in Figure 9, the throttle body 12 comprises a venturi section 12a, a throttle valve 12b, and a valve actuator 12c.
[0018] This document describes the support structure of the intake manifold 9, which is a key component of this engine; the internal and external wall structure of the collector section 40 of the intake manifold 9; the engine models that use the intake manifold 9; and the engine's oil inspection device.
[0019] The support structure for the intake manifold 9 is as follows: As shown in Figure 5, the support structure for the intake manifold 9 includes the cylinder head 6 and the fixed structure 2, and supports the intake manifold 9. As described above, the axial direction of the crank axis C shown in Figure 4 is the left-right direction, the horizontal direction perpendicular to the left-right direction is the front-rear direction as shown in Figure 3, and one side of the front-rear direction (the side the vehicle is moving forward) is the front side. As shown in Figure 5, the intake manifold 9 comprises a collector section 40 made of synthetic resin and a plurality of branch pipe sections 9a and 9b (see Figure 9 for branch pipe sections 9b) leading forward from the collector section 40. The intake outlet section 9d at the front end of each branch pipe section 9a and 9b is supported by the cylinder head 6, and the collector section 40 is supported by the fixed structure 2. As shown in Figure 5, the throttle body 12 is attached to one end of the synthetic resin collector section 40, on the side opposite to the side supported by the fixed structure 2.
[0020] As shown in Figure 5, with this intake manifold 9 support structure, the throttle body 12 is attached to one end of the collector section 40, so that the engine's front-to-rear length L is kept short, as shown in Figure 3. As shown in Figure 5, the collector section 40 is supported by the fixed structure 2, and the intake manifold 9 is supported from both the front and rear, thus reducing the burden on the front support of the intake manifold 9. As shown in Figure 5, since the collector section 40, which is located behind the cylinder head 6, is made of lightweight synthetic resin, the rotational moment caused by the vertical movement of the collector section 40 is reduced, and in this respect as well, the burden on the front support of the intake manifold 9 is reduced. Since the relatively heavy throttle body 12, which is normally located on the rear side of the collector section 40, is attached to one side of the collector section 40, the rotational moment caused by the vertical movement of the throttle body 12 is reduced compared to when it is attached to the rear side of the collector section 40. In this respect as well, the burden on the front support of the intake manifold 9 is reduced.
[0021] In this intake manifold 9 support structure, in addition to the support structure described above, as shown in Figure 7(B), the collector portion 40 is elastically supported to the fixed structure 2 via a pair of connecting plates 17·17 formed in the shape of the same isosceles triangle. The isosceles triangles of this invention include not only geometric isosceles triangles in which the three vertices are edges, but also shapes similar to geometric isosceles triangles (hereinafter referred to as "similar isosceles triangles") in which the three vertices are arc-shaped or have other shapes, and the two angles between the two sides are equal. As shown in Figure 5, the collector section 40 is elastically supported by a fixed structure via a pair of connecting plates 17, 17, and the intake manifold 9 is supported at both the front and rear, thereby reducing the burden on the front support of the intake manifold 9. Furthermore, since the collector section 40 is elastically supported by the fixed structure 2, vertical vibrations between the collector section 40 and the relatively heavy throttle body 12 are reduced, thereby reducing the burden on the front support of the intake manifold 9.
[0022] As shown in Figure 5, in this intake manifold 9 support structure, the throttle body 12 is supported by a fixed structure 12B via an intake pipe 14, and an elastic, flexible pipe 14A is used for the intake pipe 14. The fixed structure 12B is made from the vehicle's frame, but the fixed structure 12B may also be a device mounted on the vehicle.
[0023] As shown in Figure 5, with this intake manifold 9 support structure, the rear side of the intake manifold 9 is elastically supported via the flexible pipe 14A, thereby reducing vertical vibrations of the throttle body 12 and further reducing the burden on the front support of the intake manifold 9.
[0024] As shown in Figure 3, in this intake manifold 9 support structure, a fixed structure 2 is positioned below the intake manifold 9, the collector section 40 has a supported section 15 at its lower part, and the fixed structure 2 has a support section 16 that protrudes upward from its upper side, and the supported section 15 of the collector section 40 is supported by this support section 16 of the fixed structure 2. As shown in Figure 3, with this intake manifold 9 support structure, the space below the intake manifold 9 is effectively utilized as space for arranging the fixed structure 2.
[0025] As shown in Figure 8(A), in this intake manifold 9 support structure, the fixed structure 2 has a dividing mating surface 28A of the housing 2Aa, and the support portion 16 of the fixed structure 2 protrudes from the housing 2Aa along the dividing mating surface 28A. According to the support structure of the intake manifold 9 shown in Figure 8(A), the support portion 16 can be formed simultaneously when the housing 2Aa is molded using a 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 together at a dividing mating surface 28A, and the support portion 16 is formed in the right housing portion 28.
[0026] As shown in Figure 8(A), in the support structure of this intake manifold 9, the fixed structure 2 is provided with 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), with this intake manifold 9 support structure, the interposition of the elastic connector S shortens the distance between the support part 16 and the supported part 15 compared to the case where the supported part 16 and the supported part 15 are directly connected, and their rigidity is increased, thus improving the durability of the support part 16 and the supported part 15.
[0027] As shown in Figure 7(A), in the support structure of this intake manifold 9, the elastic connector S comprises a pair of connecting plates 17-17 that sandwich the support portion 16 and the supported portion 15 from both sides, a pair of fasteners 18-19 that attach the pair of connecting plates 17-17 to the support portion 16 and the supported portion 15, and a knock pin 20 that is attached to either the support portion 16 or the supported portion 15. The knock pin 20 is inserted through the pair of connecting plates 17-17, and elastic collars 23-23 are attached to at least one of the fasteners 18 of the pair of fasteners 18-19. The supported portion 15 of the collector portion 40 is elastically supported by the support portion 16 of the fixed structure 2 via the elastic collars 23-23 positioned by the pair of fasteners 18-19 and the knock pin 20. This support structure for the intake manifold 9 allows the intake manifold 9 to be elastically supported by the fixed structure 2 using a simple elastic connector S.
[0028] As shown in Figure 7(B), in the support structure of this intake manifold 9, the pair of connecting plates 17-17 each have a knock pin insertion hole 20a through which a knock pin 20 is inserted, and a fastener insertion hole 18a-19a through which a pair of fasteners 18-19 (see Figure 7(A) for fastener 18) is inserted. Furthermore, the pair of fastener insertion holes 18a-19a are arranged in a line-symmetric shape with respect to a virtual axis of symmetry 20b that transverses the knock pin insertion hole 20a in the radial direction. This pair of connecting plates 17·17 are similar isosceles triangles with three arc-shaped vertices and are made of metal plates. As shown in Figure 7(B), with this intake manifold 9 support structure, the assembly shape of the connecting plates 17-17 matches regardless of whether they are facing up or down, and the relative positions of the knock pin insertion hole 20a and the pair of fastener insertion holes 18a-19a coincide. Therefore, it is unnecessary to check the front and back of the connecting plates 17-17, and the installation work of the connecting plates 17-17 becomes easier.
[0029] As shown in Figure 7(B), a knock pin insertion hole 20a is provided at the top corner 17a of each connecting plate 17, 17, and a pair of fastener insertion holes 18a, 19a are provided at a pair of bottom corners 17b, 17b that have a different angle from the top corner 17a. As shown in Figure 7(B), with this support structure of the intake manifold 9, when installing the connecting plates 17, 17, the top corner 17a with the knock pin insertion hole 20a and the bottom corners 17b, 17b with the fastener insertion holes 18a, 19a can be identified simply by checking the difference in the angles of the corners, and the installation orientation of the connecting plates 17, 17 can be confirmed, making the installation of the connecting plates 17, 17 even easier.
[0030] As shown in Figure 7(A), the boss portion 16A of the support portion 16, which is sandwiched between the left and right connecting plates 17, 17, and each connecting plate 17, 17 are rigidly fastened and fixed by a first bolt 25 and a first nut 26 that constitute a first fastener 19, which are inserted through the boss hole 16a formed in the boss portion 16A and the fastener insertion holes 19a, 19a of each connecting plate 17, 17. The orientation of each connecting plate 17, 17 around the first bolt 25 is determined by the fitting of both ends 20p, 20p of the knock pin 20 protruding from the left and right from the support portion 16 with the knock pin insertion holes 20a, 20a of each connecting plate 17, 17 as shown in Figure 7(B).
[0031] As shown in Figure 7(A), elastic collars 23, 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 metal spacers 24 are fitted into the boss portions 23b, 23b of the elastic collars 23, 23. With the spacers 24 sandwiched between the left and right connecting plates 17, 17, the two connecting plates 17, 17 are fastened and fixed by second bolts 21 and second nuts 22 that constitute a second fastener 18, which are passed through the fastener insertion holes 18a, 18a of each connecting plate 17, 17 and the inner hole 24a of the spacer 24.
[0032] As shown in Figure 7(A), the elastic collar 23 has a cylindrical boss portion 23b and a disc-shaped flange portion 23a, forming an L-shaped cross-section. In the assembled state, when tightened with the second bolt 21 and the second nut 22, the left and right flange portions 23a are slightly compressed to the left and right. Therefore, the intake manifold 9 is elastically supported by the housing 2Aa of the transmission 2A. Alternatively, the connecting plates 17, 17, which are rigidly fixed to the supported portion 15, may be attached to the support portion 16 in an elastically supported state.
[0033] Next, the internal structure of the collector section 40 of the intake manifold 9 will be described. As shown in Figure 9, the intake manifold 9 comprises a collector section 40 and a plurality of branch pipe sections 9a and 9b leading out from the collector section 40. With the longitudinal direction of the collector section 40 being the left-right direction, a throttle communication port 41 is opened on one of the left or right ends of the collector section 40. The branch pipe sections 9a and 9b are equipped with tank-side openings 9aa and 9ba facing the internal space 40S of the collector section 40. As shown in Figure 9, the collector section 40 is provided with a boundary wall 45 at the boundary between the throttle communication port 41 and the tank-side opening 9ba of the branch pipe section 9b near the throttle communication port 41, and this boundary wall 45 is provided with an inward projection 45a that protrudes toward the internal space 40S of the collector section 40.
[0034] As shown in Figure 5, with this collector section 40, a throttle communication port 41 is opened on one end of the collector section 40, and the throttle body 12 is connected thereto, so as shown in Figure 3, the engine's front-to-rear length L is kept short. Furthermore, the internal structure of this collector section 40 equalizes the intake air volume for each cylinder. The reason for this is presumed to be as follows. The intake resistance of the inward protrusion 45a shown in Figure 9 obstructs the supply of intake air to the cylinders closer to the throttle communication port 41, where the intake air volume tends to be high. The intake air that is not used to supply these cylinders is supplied to the distant cylinders, where the intake air volume tends to be low, thus equalizing the intake air volume to each cylinder.
[0035] As shown in Figure 9, in the internal structure of this collector portion 40, the inner surface of the inwardly projecting portion 45a is formed by an inwardly projecting arcuate surface 45aa. According to the internal structure of this collector section 40, the inwardly protruding arcuate surface 45aa shown in Figure 9 makes it difficult for turbulence to occur in the intake air, and the supply of intake air to each cylinder is less likely to be obstructed by turbulence.
[0036] Next, the exterior wall structure of the collector section 40 will be described. As shown in Figure 9, in the outer wall structure of this collector section 40, of the left and right end walls of the collector section 40, the end wall 40e on the opposite side from the end wall with the throttle communication port 41 protrudes further toward the opposite side of the throttle than the internal passage 9ac of the branch pipe section 9a on the opposite side of the throttle. According to the outer wall structure of the collector section 40, at the anti-throttle side end wall 40e shown in Figure 9, the internal space 40S of the collector section 40 is expanded on the anti-throttle side than the internal passage 9ac of the anti-throttle side branch pipe section 9a, promoting intake to cylinders farther from the throttle communication port 41, and making the intake volume of each cylinder more uniform.
[0037] As shown in Figure 9, in the outer wall structure of this collector portion 40, the end wall 40c of the collector portion 40 on the side opposite the cylinder head protrudes further away from the cylinder head than the throttle communication port 41.
[0038] According to the outer wall structure of this collector portion 40, at the end wall 40c on the side opposite the cylinder head as shown in Figure 9, the internal space 40S of the collector portion 40 is expanded toward the side opposite the cylinder head than the throttle communication port 41, promoting intake to cylinders farther from the throttle communication port 41, and making the intake volume of each cylinder more uniform. In Figure 10, reference numeral 40a denotes the top wall of the collector unit 40, and reference numeral 40b denotes the bottom wall.
[0039] Next, we will explain engine models that use an intake manifold. As shown in Figure 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 the collector section 40, and is used in a two-cylinder engine. When this intake manifold 9 is used in a two-cylinder engine with a large difference in the intake path from the throttle communication port 41, the effect of equalizing the intake volume of each cylinder becomes apparent.
[0040] The pair of branch pipe sections 9a and 9b shown in Figure 5 (see Figure 9 for branch pipe section 9b) extend straight and parallel from the collector section 40 toward the cylinder head 6. As shown in Figure 9, the peripheral walls 9ab and 9bb of the tank-side openings 9aa and 9ba of the pair of branch pipe sections 9a and 9b both protrude from the cylinder head-side end wall 40d of the collector section 40 toward the internal space 40S of the collector section 40.
[0041] This intake manifold 9 is used in a 4-stroke inline 2-cylinder engine where the crankpin angle of the crankshaft 1A shown in Figure 4 is 180°, and the phase difference between the intake stroke of the second cylinder on the throttle communication port 41 side shown in Figure 9 and the intake stroke of the first cylinder that follows it is 180° in crank angle. When used in this engine model, the intake stroke of the first cylinder, which begins with a relatively small 180° phase difference after the intake stroke of the second cylinder, is prone to insufficient intake. When this intake manifold is used in the above engine, the effect of equalizing the intake volume of each cylinder becomes even more pronounced.
[0042] Next, I will explain the engine oil inspection device. The engine 2 shown in Figure 2(A) is equipped with an oil inspection device, which, as shown in Figure 11, includes an oil gauge 30, a guide pipe 53 that guides the oil gauge 30 into the engine oil EO in the oil pan 8, and a support pipe 52 that supports the guide pipe 53 to the crankcase 1. The support pipe 52 is inserted through the support pipe insertion hole 51 of the crankcase 1. The lower end of the guide pipe 53 is provided with an internal fitting portion 53A, which is fitted and fixed to the upper end of the support pipe 52. A projection 54 is provided around the inner circumference of the internal fitting portion 53A, and the middle part of the guide pipe 53 is provided with a curved portion 53c. As shown in Figure 11, the curved portion 53c causes the upper part of the guide pipe 53 to tilt upward away from the crankcase 1, and the oil gauge 30 inserted into the guide pipe 53 is configured to contact the inner surfaces of the curved portion 53c, the protrusion 54, and the support pipe 52.
[0043] This engine oil inspection device is suitable when, due to the engine mounting environment, the only access route to the oil inspection device is diagonally above the guide pipe 53. It allows access from diagonally above the guide pipe 53, and the oil gauge 30 can be inserted and removed along the diagonally upward direction of the guide pipe 53. Furthermore, as shown in Figure 11, with this engine oil inspection device, the oil gauge 30 inserted into the guide pipe 53 contacts three points: the curved portion 53c, the protrusion 54, and the inner surface of the support pipe 52. This provides significant resistance to the oil gauge 30 being pulled out, preventing it from being pulled out of the guide pipe 53 by inertia when the vehicle equipped with the engine is braked.
[0044] As shown in Figure 11, the oil inspection device for this engine is provided with a tapered section 52D at the lower end of the support pipe 52, the inner diameter of which gradually decreases downwards. As shown in Figure 11, with this engine oil inspection device, the oil gauge 30 that penetrates the support pipe 52 is received inside the tapered portion 52D at the lower end of the support pipe 52, and the swinging of the oil gauge 30 that protrudes from the support pipe 52 towards the oil pan 8 is suppressed.
[0045] As shown in Figure 11, in this engine oil inspection device, the inner fitting portion 53A of the guide pipe 53 is enlarged in diameter, and the oil gauge 30 inserted into the guide pipe 53 is configured to contact the non-enlarged portion 53Aa of the guide pipe 53 adjacent to the enlarged inner fitting portion 53A above it. As shown in Figure 11, with this engine oil inspection device, the oil gauge 30 also contacts the non-enlarged portion 53Aa of the guide pipe 53 adjacent to the inner fitting portion 53A, thus increasing the resistance to pulling out the oil gauge 30.
[0046] As shown in Figure 11, in this engine oil inspection device, a concave groove 54a is provided around the outer circumference of the protrusion 54, and an O-ring 54b is fitted inside this concave groove 54a, and this O-ring 54b seals the gap 54c between the inner fitting portion 53A of the guide pipe 53 and the support pipe 52. According to this engine's oil inspection device, the sealing performance of the 54c gap between pipes is improved.
[0047] As shown in Figure 11, in this engine oil inspection device, the upper end portion 52a of the support pipe 52 is spaced upward from the upper edge portion 51a of the support pipe insertion hole 51 of the crankcase 1.
[0048] As shown in Figure 11, with this engine oil inspection device, foreign matter such as dust accumulated around the support pipe insertion hole 51 cannot enter the gap between the pipes 54c from the upper end 52a of the support pipe 52 which is spaced apart upwards d, thus preventing damage to the O-ring 54b due to foreign matter getting caught.
[0049] As shown in Figure 11, the guide pipe 53, made of metal or the like, has an inner fitting portion 53A that is fitted into the enlarged diameter portion 52A of the support pipe 52, an upper end (base end) 53B into which the plug portion 30A made of elastic material fitted to the upper end of the oil gauge 30 is fitted, and an intermediate portion 53C between the inner fitting portion 53A and the upper end portion 53B. The intermediate portion 53C, which is the diameter of the original pipe material, has a curved portion 53c formed in which its longitudinal intermediate portion is bent at an angle x (e.g., 35 to 45 degrees).
[0050] As shown in Figure 11, the upper end portion 53B has an enlarged diameter opening 53b, which is the area where the original pipe material is enlarged in diameter and the plug portion 30A is tightly fitted inside. The upper side (base end side) of the enlarged diameter opening 53b is formed as a groove portion 58, and the lower side (tip side) is formed as a diameter change portion 59, where the diameter gradually increases from the original diameter toward the enlarged diameter opening 53b. The diameter of the enlarged diameter opening 53b is set to such a degree that the plug portion 30A, which is pushed into its inner circumferential surface by finger manipulation, cannot easily come out.
[0051] As shown in Figure 11, the oil gauge 30 has a gripping portion 30B at the top (base end) made of a metal rod, a gauge portion 30C connected and integrated to the lower part of the gripping portion 30B by a rivet 60, and a plug portion 30A fitted onto the gripping portion 30B. The plug portion 30A has a stepped cylindrical portion 30a that is lightly press-fitted into the enlarged opening 53b and a large-diameter stop portion 30b that is received by the groove portion 58. The upper end of the gripping portion 30B is rounded at approximately 270 degrees to form a hook portion 30f through which a finger can be inserted.
[0052] As shown in Figure 11, the gauge portion 30C is made of a thin, flat, elongated plate-like material (e.g., spring steel) with a flexible surface, and has first and second twisted portions 61 and 62 formed at its lower end, twisted at 180 degrees and at its lower end, twisted at 90 degrees, respectively. The line N shown in Figure 11 represents the upper limit of the engine oil EO accumulated in the oil pan 8 and the lower part of the crankcase 1.
[0053] As shown in Figure 11, a metal plate bracket 64 is attached to the guide pipe 53 between the inner fitting portion 53A and the curved portion 53c by means of welding or other means. The bracket 64 can be fastened and secured to a mounting boss 50A formed in the crankcase 1 by bolts 65 through holes (not shown) formed in the bracket 64. The mounting boss 50A is the boss portion for mounting the oil gauge in the crankcase of the engine before the improvement, and in this engine it is effectively utilized as a boss for screwing in bolts 65. Figure 12 shows a perspective view of the oil inspection device and its surrounding area from Figure 11, and Figure 13 shows an enlarged perspective view of the oil inspection device from Figure 12.
[0054] In the multi-purpose four-wheeled vehicle V shown in Figure 1, as shown in Figure 2(A), the engine E is located behind the seat 34A and under the front of the cargo bed 35, the oil inspection device is located on the front side of the crankcase 1, and the upper part of the guide pipe 53 extends diagonally upward and forward. As shown in Figure 3, the gripping portion 30B at the upper end of the oil gauge 30 is located behind the back plate 38b, which is a support member of the seat 34A (see Figures 2(A) and 2(B)). The back plate 38b is provided with an openable (or removable) cover 66. By opening (or removing) the cover 66, the oil inspection device can be accessed from diagonally above and in front of the guide pipe 53, and the oil gauge 30 can be inserted and removed along the guide pipe 53 in a diagonally upward direction to check the engine oil level. Reference numeral 67 in Figure 3 indicates an oil filter. [Explanation of Symbols]
[0055] 9...Intake manifold, 9a·9b...Branch pipe section, 9aa·9ba...Tank side opening, 9d...Intake outlet section, 12...Throttle body, 12B...Fixed structure, 14...Intake piping, 14A...Flexible pipe, 15...Supported section, 16...Support section, 28A...Separation mating surface, 40...Collector section, 40S...Internal space, 40e...End wall on the side opposite the throttle, 40c...End wall on the side opposite the cylinder head, 41...Throttle communication port, 45...Boundary wall, 45a...Inward projection, 45aa...Arch surface.
Claims
1. It comprises a collector section (40) and a plurality of branch pipe sections (9a) and (9b) led out from the collector section (40), With the longitudinal direction of the collector portion (40) being the left-right direction, a throttle communication port (41) is opened on one end of the collector portion (40). The branch pipe sections (9a) and (9b) are provided with tank-side openings (9aa) and (9ba) facing the internal space (40S) of the collector section (40). The collector section (40) is provided with a boundary wall (45) at the boundary between the throttle communication port (41) and the tank-side opening (9ba) of the branch pipe section (9b) near the throttle communication port (41). This boundary wall (45) has an inward projection (45a) formed by an inwardly projecting arcuate surface (45aa) that protrudes toward the internal space (40S) of the collector section (40), and an outward projection that, conversely, protrudes toward the outside from the internal space (40S) of the collector section (40). The outward projection is provided near the throttle communication port (41), and the inward projection (45a) is provided near the tank-side opening (9ba) of the branch pipe section (9b) near the throttle communication port (41). An intake manifold characterized in that the peripheral walls (9ab) and (9bb) of the tank-side openings (9aa) and (9ba) of the branch pipe sections (9a) and (9b) protrude from the cylinder head-side end wall (40d) of the collector section (40) toward the internal space (40S) of the collector section (40).
2. In the intake manifold described in claim 1, An intake manifold characterized in that, of the left and right end walls of the collector section (40), the anti-throttle side end wall (40e) opposite to the end wall with the throttle communication port (41) protrudes further to the anti-throttle side than the internal passage (9ac) of the anti-throttle side branch pipe section (9a).
3. In the intake manifold described in claim 1, An intake manifold characterized in that the end wall (40c) of the collector portion (40) on the side opposite the cylinder head protrudes further toward the side opposite the cylinder head than the throttle communication port (41).
4. In an intake manifold according to any one of claims 1 to 3, An intake manifold characterized by having a collector section (40) from which a pair of left and right branch pipe sections (9a) and (9b) are led out, and being used in a two-cylinder engine.
5. In the intake manifold described in claim 4, An intake manifold characterized in that the crankpin angle of the crankshaft (1A) is 180°, and the phase difference between the intake stroke of the second cylinder on the throttle communication port (41) side and the intake stroke of the first cylinder that follows it is 180° in crank angle, and is used in a four-stroke inline two-cylinder engine.