CONNECTION STRUCTURE OF AN INLET PIPE

Abstract

Connecting structure of an inlet pipe (1) for an engine head (2), comprising: a partition wall element (5) which divides an inlet passage (3) along its axial direction and is inserted into the engine head (2); and an elastic seal (17) having a frame shape provided between the engine head (2) and the intake pipe (1) to seal therebetween, wherein the inlet pipe (1) is provided at its connecting end portion (1a) with an elastic body (21) which presses the partition wall element (5) in its insertion direction, the elastic body (21) is formed integrally in the elastic seal (17), and the inlet pipe (1) is provided at its connecting end portion (1a) with a recess portion (11) which is recessed in an axial direction of the inlet pipe (1), wherein the recess portion (11) is provided on its inner wall with a step portion (12) which holds a portion of the elastic body (21) on its insertion side which can be inserted into the recess portion (11), characterized in that the elastic body (21) comprises: a main body (24) inserted into the recess portion (11) and held by the step portion (12); a pressing portion (25) projecting from an end face of the main body (24) opposite the engine head (2) to press the partition wall element (5); and a contact portion (26) extending from the main body (24) in its insertion direction to the recess portion (11) to be brought into contact with a side surface of the step portion (12).

Description

BACKGROUND OF THE INVENTION(1) Field of the invention

[0001] The present invention relates to a connecting structure of an intake pipe according to the preamble of claim 1, and more particularly to a connecting structure of an intake pipe for an engine head. (2) Description of the state of the art

[0002] As a conventional connecting structure of an intake pipe, a connecting structure of an intake pipe for an engine head is generally known (see, for example, JP 2017-150366 A). JP 2017-150366 A discloses a technique of holding a partition member between an engine head and an intake pipe, wherein the partition member is inserted into the engine head along its axial direction to divide an intake passage. The partition member includes a metal partition plate for dividing the intake passage and resin fitting portions provided on both sides across the metal partition plate, and the fitting portion is inserted into a recess portion formed on an inner wall of the intake passage of the engine head from the axial direction of the intake passage (see paragraph

[0015] of JP 2017-150366 A).According to this technique, a tumble flow (rolling flow, charge rotation transverse to the cylinder axis) for improving fuel economy or the like is generated in a combustion chamber of the engine when a valve in the intake pipe reduces an opening degree of an intake port divided by the partition wall member.

[0003] However, the technique shown in JP 2017-150366 A holds the partition member between the engine head and the intake pipe by inserting it into the engine head without using rigid fastening with a bolt or the like, so that the partition member (particularly the resin insert portion) slides against the engine head due to engine pulsation. This causes the partition member to wear, raising concerns that abrasion powder from the partition member may adversely affect combustion.

[0004] JP 2008-151 078 A shows a generic connecting structure of an inlet pipe with the features of the preamble of claim 1.

[0005] The subsequently published DE 10 2017 220 793 A1 shows an intake device for an engine comprising the following parts: an intake manifold provided to allow intake air to flow in; a cylinder head through which an intake channel is formed so that intake air flowing in through an intake manifold is supplied into cylinders of the engine; a flow control valve arranged in the intake manifold and capable of regulating a flow direction of the intake air to generate a tumble flow in the intake air flowing into the cylinder head from the intake manifold; a control plate configured to reinforce a tumble flow of the intake air resulting from the flow control valve;and a control plate support portion connected to the control plate and connected between the intake manifold and the cylinder head so that the control plate is inserted into the intake port, thereby enhancing the tumble flow of the intake air, improving durability, reducing the loss of the generated tumble flow, and ultimately improving the performance of the engine.; SUMMARY OF THE INVENTION

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to provide a joint structure of an intake pipe capable of suppressing sliding of a partition wall member against an engine head due to engine pulsation.

[0007] The object is achieved by a connecting structure of an inlet pipe having the features of claim 1. Advantageous developments of the present invention are the subject of the dependent claims.

[0008] The connecting structure of the intake pipe of the present invention includes a partition member that divides the intake passage along its axial direction and is inserted into an engine head, and an elastic seal having a frame structure provided between the engine head and the intake pipe to seal therebetween. The intake pipe is provided at its connecting end portion with an elastic body that urges the partition member in its insertion direction. Accordingly, the elastic body urges the partition member in the insertion direction, so that sliding of the partition member against the engine head due to engine pulsation is suppressed.

[0009] Because the elastic body is formed integrally in the elastic seal according to the invention, the elastic body and the elastic seal can be easily handled as a one-piece body.

[0010] According to the invention, since the inlet pipe is provided with a recess portion at its connecting end portion and a stepped portion on its inner wall, which holds a portion of the elastic body on its insertion side to be inserted into the recess portion, holding by the stepped portion limits displacement of the portion of the elastic body on its insertion side into the recess portion. This not only makes it possible to establish a holding structure of the elastic body using the recess portion, but also allows the recess portion to prevent the inlet pipe from increasing in thickness, thus suppressing defective molding and prolonging a lead time.

[0011] Preferably, if the elastic body is formed in an elongated shape in plan view, and the step portion includes a middle step portion and an end step portion, the middle step portion supports a middle portion of the elastic body in its longitudinal direction, and the end step portion supports an end portion of the elastic body in its longitudinal direction. This allows the step portion to stably support the elastic body even if the elastic body deteriorates over time. As a result, the elastic body can effectively press the partition member for a long period of time.

[0012] Additionally, if the elastic body preferably comprises a main body, a pressing portion, and a contact portion, the pressing portion presses the partition member in its insertion direction, with the contact portion in contact with a side surface of the step portion that holds the main body. This allows the step portion to stably hold the elastic body even if the elastic body deteriorates over time. As a result, the elastic body can effectively press the partition member for a long period of time.

[0013] Preferably, when the contact portion comprises a contact plate and a pair of supports, the elastic body can press the partition member more effectively.

[0014] Preferably, when the partition member comprises a partition plate and an insertion portion, and the elastic body is provided to press the insertion portion in the insertion direction, the elastic body presses the insertion portion of the partition member in the insertion direction to suppress sliding of the partition member against the engine head due to pulsation of the engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention is further described in the following detailed description with reference to the aforementioned plurality of drawings which are non-limiting examples of exemplary embodiments of the present invention, in which like reference numerals represent similar parts throughout the several views of the drawings, and wherein: Fig. 1 is a longitudinal sectional view of a connecting structure of an inlet pipe according to an embodiment; Fig. 2 an enlarged sectional view along a line II-II of the Fig. 1 is; Fig. 3A and Fig. 3B each shows an enlarged sectional view along a line III-III of the Fig. 1, where Fig. 3A shows a state in which an elastic seal is provided, and Fig. 3B shows a state in which the elastic seal is removed; Fig. Figure 4 is a perspective view of the elastic seal; Fig. 5 is an enlarged view of a main part, in the direction of an arrow V of the Fig. 4 considered, is; Fig. 6 is a perspective view of a partition wall element according to an embodiment; Fig. 7A and Fig. 7B each illustrate a connection structure of an inlet pipe according to other embodiments, wherein Fig. Figure 7A shows another embodiment comprising an elastic body separated from an elastic seal, and Fig. 7B shows yet another embodiment in which an inlet pipe does not include a recess portion; and Fig. 8 shows a connection structure of an inlet pipe according to still another embodiment. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0016] The details shown herein are merely examples and for the purpose of illustrative discussion of embodiments of the present invention and are presented because they are believed to be the most useful and easily understood description of the principles and conceptual aspects of the present invention. In this regard, no attempt is made to show structural details of the present invention in more detail than is necessary for a basic understanding of the present invention, the description being made with the aid of the drawings, which will make it apparent to those skilled in the art how the embodiments of the present invention may be practiced.

[0017] A connecting structure of an intake pipe according to the present embodiment is a connecting structure of an intake pipe (1) for an engine head (2), the connecting structure comprising a partition member (5) dividing an intake passage (3) along its axial direction and inserted into the engine head, and an elastic seal (17) having a frame shape provided between the engine head and the intake pipe to seal therebetween, the intake pipe being provided at its connecting end portion (1a) with an elastic body (21) pressing the partition member in its insertion direction (see, for example, Fig. 1 and Fig. 2, etc.). The intake pipe is usually a pipe for supplying intake air to a combustion chamber of an engine.

[0018] Examples of the connection structure of the intake pipe according to the present embodiment include an embodiment in which the elastic body (21) is integrally formed in the elastic seal (17) (see, for example, Fig. 4 etc.).

[0019] Examples of the connection structure of the inlet pipe according to the present embodiment include an embodiment in which the inlet pipe (1) is provided at its connection end portion (1a) with a recessed portion (11) which is recessed in an axial direction of the inlet pipe, and the recessed portion is provided at its inner wall with a step portion (12) for holding a portion of the elastic body (21) on its insertion side to be inserted into the recessed portion (see, for example, Fig. 2 and Fig. 3 etc.).

[0020] In the case of the above-mentioned embodiment, the elastic body (21) may be formed in an elongated shape in a plan view, and for example, the step portion (12) may include a middle step portion (12a) holding a middle portion of the elastic body in its longitudinal direction and an end step portion (12b) holding an end portion of the elastic body in its longitudinal direction (see, for example, Fig. 3 etc.).

[0021] In the case of the above-mentioned embodiment, the elastic body (21) may, for example, comprise a main body (24) inserted into the recess portion (11) and held by the step portion (12), a pressing portion (25) projecting from an end surface of the main body toward the engine head (2) to press the partition wall member (5), and a contact portion (26) extending from the main body in its insertion direction toward the recess portion (11) to be brought into contact with a side surface of the step portion (12) (see, for example, Fig. 2 and Fig. 4 etc.).

[0022] Examples of the connection structure of the intake pipe according to the present embodiment include an embodiment in which the partition member (5) comprises, for example, a partition plate (5a) dividing the intake passage (3), and fitting portions (5b) provided on both sides of the partition plate, which are fitted into corresponding recess portions (6) from an axial direction of the intake passage formed in an inner wall of the intake passage of the engine head (2), and in which the elastic member (21) presses the fitting portion in its fitting direction (see, for example, Fig. 2 and Fig. 7 etc.)

[0023] The reference numeral in parentheses of each element described in the above embodiments indicates correspondence with a particular element described in the embodiments described below. Embodiments

[0024] Hereinafter, the present invention will be described in detail using embodiments with reference to the drawings. In the present embodiment, an intake pipe 1 of an intake manifold connected to an intake passage 3 of an engine head 2 (also referred to as a "cylinder head") is exemplified as an "intake pipe" according to the present invention (see Fig. 1). (1) Connection structure of an inlet pipe

[0025] In a connecting structure of the intake pipe 1 according to the present embodiment, the engine head 2 has the intake passage 3 into which a partition wall member 5 for dividing the intake passage 3 into two intake passages 3a and 3b along its axial direction from the outside in the axial direction is inserted, as shown in Fig. 1. The partition member 5 includes a partition plate 5a made of a metal for dividing the intake passage 3, and a pair of insertion portions 5b and 5b provided on both sides of the partition plate 5a, which are inserted into corresponding recess portions 6 formed in an inner wall of the intake passage 3 of the engine head 2 from the outside in the axial direction of the intake passage (see Fig. 7). The partition plate 5a extends from the intake passage 3 of the engine head 2 to an intake passage 9 of the intake pipe 1. One end of each of the insertion portions 5b is exposed at an end surface of the engine head 2. The intake pipe 3 includes a valve 8 rotatably provided inside the intake passage 3a for changing an opening degree of the intake passage 3a partitioned by the partition member 5.

[0026] As in the Fig. 2 and Fig. 3, a pair of recessed portions 11, which are recessed in the axial direction of the intake pipe 1, are internally provided with an elastic seal 17, which will be described later, in a connecting end portion 1a of the intake pipe 1. Each of the recessed portions 11 is arranged at a position corresponding to the corresponding insert portions 5b of the partition wall member 5 inserted into the engine head 2. In other words, each of the recessed portions 11 is arranged at a position where a pressing portion 25, which will be described later, can be inserted for pressing the insert portion 5b.

[0027] Each of the recessed portions 11 is provided on its inner wall with a step portion 12 that supports an insertion-side surface of the elastic body 21, described below, to be inserted into the corresponding recessed portions 11. The step portion 12 includes a middle step portion 12a that supports a middle portion of the elastic body 21 in its longitudinal direction, and a pair of end step portions 12b and 12b that support an end portion of the elastic body 21 in its longitudinal direction. The step portions 12a and 12b are provided on an inner wall 14 near the axis of the inlet pipe 1, which is a part of an inner wall of the recessed portion 11, but are not provided on an outer wall 5 opposite the inner wall. The step portions 12a and 12b each have a lower end extending to a bottom surface of each of the recessed portions 11.The connecting end portion 1a of the above-mentioned inlet pipe 1 is formed in a shape of a flange (see . Fig. 1).

[0028] Between the engine head 2 and the intake pipe 1, the elastic seal 17 is provided, which has a frame shape and is made of rubber (or made of an elastomer), for sealing between the engine head 2 and the intake pipe 1 (see Fig. 4), as in the Fig. 1 to 3. The elastic seal 17 is arranged to surround the partition wall member 5. The elastic seal 17 is mounted in mounting grooves 18 and 19 formed in the connecting end portions of the intake pipe 1 and the engine head 2, respectively. The elastic seal 17 is integrally formed from a plurality of elastic seals corresponding to the number of cylinders of the engine.

[0029] As in the Fig. As shown in FIGS. 2 to 4, the elastic body 21 is provided for pressing the insertion portion 5b of the partition wall member 5 in the insertion direction into the elastic seal 17 in the connecting end portion 1a of the intake pipe 1. The elastic body 21 is integrally formed with the elastic seal 17 on its inner peripheral side, with connecting portions 22 provided therebetween. The elastic body 21 is formed in an elongated shape in a plan view.The elastic body 21 includes a main body 24 inserted into the recess portion 11 and held by each of the step portions 12a and 12b, a pressing portion 25 protruding from an end surface of the main body 24 facing the engine head 2 to press the insertion portion 5b of the partition member 5, and a contact portion 26 extending from the main body 24 in its insertion direction toward the recess portion 11 to be brought into contact with a side surface of the middle step portion 12a. The main body 24 is formed in a shape that can be press-fitted into the recess portion 11. The contact portion 26 includes a contact plate 26a brought into contact with a side surface of the intermediate stage portion 12a, and a pair of supports 26b and 26b provided on both sides of the contact plate 26a and laterally supporting the intermediate stage portion 12a (see . Fig. 5). (2) Operation of a connecting structure of an inlet pipe

[0030] Next, an operation of the connecting structure of the intake pipe 1 having the above-described configuration will be described. As shown in Fig. As shown in Fig. 1, when an opening degree of the one intake passage 3a by the valve 8 in an open state (indicated by a virtual line in the drawing) is maximized, intake air flowing through the intake pipe 1 flows through each of the intake passages 3a and 3b to be supplied to the combustion chamber of the engine. Meanwhile, when the opening degree of the one intake passage 3a by the valve 8 in a closed state (indicated by a solid line in the drawing) is minimized, the intake air flowing through the intake pipe 1 hardly flows through the one intake passage 3a and flows through the other intake passage 3b to be supplied to the combustion chamber of the engine.Then the intake air is supplied to the combustion chamber at an increased flow rate, so that a tumble flow (rolling flow, charge rotation transverse to the cylinder axis) is generated in order to achieve rapid combustion of a fuel therein.

[0031] The connecting structure of the intake pipe 1 is configured such that, while a space between the engine head 2 and the intake pipe 1 is sealed by the elastic seal 17, the elastic body 21, using its surface pressure, pushes the pair of insertion portions 5b and 5b of the partition wall member 5 in their insertion direction (or in a downstream direction of the intake air flow). This suppresses sliding (vibration) of the insertion portions 5b in the corresponding recessed portions 6 due to engine pulsation. (3) Effect of the embodiments

[0032] The connection structure of the intake pipe 1 of the present embodiment is configured such that the partition member 5, which divides the intake passage 3 along its axial direction, is inserted into the engine head 2, and the elastic seal 17, which has a frame shape, is provided between the engine head 2 and the intake pipe 1 to seal therebetween. The elastic body 21 is provided in the connection end portion 1a of the intake pipe 1 to urge the partition member 5 in its insertion direction. Accordingly, the elastic body 21 urges the partition member 5 in the insertion direction, so that sliding of the partition member 5 against the engine head 2 due to engine pulsation is suppressed.

[0033] The present embodiment is configured such that the elastic body 21 is integrally formed with the elastic seal 17. This allows the elastic body 21 and the elastic seal 17 to be easily handled as a single unit.

[0034] In addition, the present example is configured such that the intake pipe 1 is provided with the recess portion 11 at its connecting end portion 1a, and the recess portion 11 is provided on its inner wall with the step portion 12 for holding a portion of the elastic body 21 on its insertion side to be inserted into the recess portion 11. As a result, displacement (or falling) of the portion of the elastic body 21 on its insertion side into the recess portion 11 is limited by holding the step portion 12. This not only enables a holding structure of the elastic body 21 to be defined using the recess portion 11, but also allows the recess portion 11 to prevent the intake pipe 1 from increasing in thickness to suppress defective molding and an increase in a lead time.

[0035] The present embodiment is configured such that the elastic body 21 is formed in an elongated shape in a plan view, and the step portion 12 includes the middle step portion 12a and the end step portion 12b. Consequently, the middle step portion 12a supports a middle portion of the elastic body 21 in its longitudinal direction, and the end step portion 12b supports an end portion of the elastic body 21 in its longitudinal direction. This allows the step portion 12 to stably support the elastic body 21 even if the elastic body 21 deteriorates over time. As a result, the elastic body 21 can effectively press the partition wall member 5 for a long period of time.

[0036] In addition, the present embodiment is configured so that the elastic body 21 includes the main body 24, the pressing portion 25, and the contact portion 26. As a result, the pressing portion 25 presses the partition member 5 in its insertion direction with the contact portion 26 in contact with a side surface of the step portion 12 that holds the main body 24. This allows the step portion 12 to stably hold the elastic body 21 even if the elastic body 21 deteriorates over time. As a result, the elastic body 21 can effectively press the partition member 5 for a long period of time.

[0037] In the present invention, the elastic body 21 is provided integrally with the elastic seal 17. For example, in an alternative not claimed, the elastic body 21 may be provided separately from the elastic seal 17, as shown in Fig. 7A is shown.

[0038] The holding structure (or the step portion 12) of the elastic body 21 is fixed using the recess portion 11. For example, in an unclaimed alternative, the connecting end portion 1a of the inlet pipe 1 may be provided with a recess portion 29 for holding a bottom portion of the elastic body 21 without providing the recess portion 11, as shown in Fig. 7B is shown.

[0039] According to the invention, the step portion 12 is provided on the inner wall 14 of the recess portion 11. For example, in a non-claimed alternative, the step portion 12 can be provided in both the inner wall 14 and the outer wall 15 of the recess portion 11, as shown in Fig. 7A. In addition, as shown in Fig.8, for example, stepped ribs 30 connected between the inner wall 14 and the outer wall 15 of the recess portion 11 may be used.

[0040] The present invention is widely used as a technique related to a connecting structure of an intake pipe for an engine head used in vehicles such as cars, buses, and trucks.

Claims

[1] Connecting structure of an inlet pipe (1) for an engine head (2), comprising: a partition wall element (5) which divides an inlet passage (3) along its axial direction and is inserted into the engine head (2); and an elastic seal (17) having a frame shape provided between the engine head (2) and the intake pipe (1) to seal therebetween, wherein the inlet pipe (1) is provided at its connecting end portion (1a) with an elastic body (21) which presses the partition wall element (5) in its insertion direction, the elastic body (21) is formed integrally in the elastic seal (17), and the inlet pipe (1) is provided at its connecting end portion (1a) with a recess portion (11) which is recessed in an axial direction of the inlet pipe (1), wherein the recess portion (11) is provided on its inner wall with a step portion (12) which holds a portion of the elastic body (21) on its insertion side which can be inserted into the recess portion (11), characterized by that the elastic body (21) comprises: a main body (24) inserted into the recess portion (11) and held by the step portion (12); a pressing portion (25) projecting from an end face of the main body (24) opposite the engine head (2) to press the partition wall element (5); and a contact portion (26) extending from the main body (24) in its insertion direction to the recess portion (11) to be brought into contact with a side surface of the step portion (12). [2] The connecting structure of the inlet pipe (1) according to claim 1, wherein the elastic body (21) is formed in an elongated shape in a plan view, and the step portion (12) comprises a middle step portion (12a) holding a middle portion of the elastic body (21) in its longitudinal direction, and an end step portion (12b) holding an end portion of the elastic body (21) in its longitudinal direction. [3] The connecting structure of the intake pipe (1) according to claim 1 or 2, wherein the contact portion (26) comprises a contact plate (26a) brought into contact with a side surface of the step portion (12), and a pair of supports (26b) provided on both sides of the contact plate (26a) for laterally supporting the step portion (12). [4] The connecting structure of the inlet pipe (1) according to any one of claims 1-3, wherein the partition wall element (5) comprises a partition wall plate (5a) dividing the intake passage (3), and insertion portions (5b) provided on both sides of the partition wall plate (5a) and inserted into corresponding recessed portions from an axial direction of the intake passage (3) formed on an inner wall of the intake passage (3) of the engine head (2), and the elastic body (21) is provided to press the insertion portion (5b) in its insertion direction.

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