JP2014145350A - Flow passage connecting structure of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an increase of processing costs of members for securing seal performance, and to improve the efficiency of the fastening work of the mutual members, in an internal combustion engine in which the two members are laminated on and fixed to each other, and fluid passages of both the members are connected to each other.SOLUTION: A joint pipe 14 is fixed to a surge tank 3 being one member, and a throttle body 5 being the other member is laminated on and fixed to the surge tank 3. A cooling water passage 15 communicating with the joint pipe 14 is opened at the throttle body 5. A flange 18 arranged at the joint pipe 14 is welded to the surge tank 3. An O-ring 21 is fit to an annular ring 19 formed at the flange 18. Since the O-ring 21 is fit to the joint pipe 14, the surge tank 3 is dispensed with particular processing, and a cost increase can be prevented. Since the O-ring 21 is held at the joint pipe 14 in a fall-off prevention manner, a time and labor for assembling can be reduced.

Description

  The present invention relates to a flow path connection structure of two members in an internal combustion engine in which two members having flow paths through which a fluid flows are fixed.

  In an internal combustion engine, a fluid such as cooling water or oil is used. Therefore, there are many members in which a fluid passage is formed. For example, Patent Document 1 describes that a cooling unit is provided at an inlet portion (collecting portion) of an intake manifold. In Patent Document 1, an inlet pipe and an outlet pipe of the cooling unit are provided at an inlet portion of the intake manifold. Are integrally provided, and a cooling water hose is connected to these pipes.

  In this Patent Document 1, the throttle body is fixed at the inlet of the intake manifold. Although it is necessary to position the throttle body accurately, in Patent Document 1, since there is no positioning means, the assembly is troublesome. In Japanese Patent Application Laid-Open No. 2004-228620, a joint pipe that penetrates through the throttle body is protruded from the inlet portion of the intake manifold, and a cooling water passage provided in the throttle body is fitted into the joint pipe to form a cooling water passage. Also disclosed is a structure for positioning the throttle body.

JP-A-11-159354 Japanese Patent Application No. 2012-215749

  Now, there is a structure in which members having fluid passages are overlapped and connected to each other and the fluid passages are connected to each other in the internal combustion engine. In this case, the mating surfaces of the two members are formed flat, In order to ensure the sealing performance between the members, a sealing material such as an O-ring or a gasket is interposed between the two members. The sealing material is generally fitted in an annular groove provided in one member.

  However, in some cases, it may be troublesome to form the annular groove in the member. In other words, when post-processing must be performed, it takes time and effort, and even in the case of molded products such as resin products and die-cast products, a slide mold is required and the structure of the mold becomes complicated. Such problems often occur. Furthermore, since the mating surfaces of the two members are flat, the sealing material can easily fall off the annular groove, and the fixing operation of the members can be troublesome.

  The present invention has been made to improve such a current situation, and the point of projecting a joint pipe from one member follows the idea of Patent Document 2 while ensuring sealing performance with a simple structure. The assembly efficiency is also improved.

  In the present invention, a joint pipe having an outward projecting portion is provided on one of two members overlapping each other, and the other member is fitted into the outward projecting portion of the joint pipe to fix both members. Thus, in the internal combustion engine in which the fluid passage of the other member is connected to the joint pipe, the joint pipe is a member different from the one member, and the one of the joint pipes protrudes outward from the joint pipe. A flange that overlaps the surface of the member is formed, an annular groove that opens toward the other member is formed in the flange, and a sealing material that is pressed by the other member is fitted into the annular groove. Yes.

  The present invention can be applied to each part of an internal combustion engine. For example, as in Patent Document 2, it can be applied to a cooling water passage connection between an intake manifold and a throttle body. Alternatively, it can be applied to connection of an intake passage, connection of oil, and the like. In addition, as means for fixing the joint pipe to one member, forced fitting by driving, interference fitting using heat shrinkage, vibration welding (when the joint pipe and one member are made of resin), adhesion with an adhesive, etc. There are various aspects.

  According to the present invention, since the annular groove into which a sealing material such as an O-ring is fitted is formed in the flange of the joint pipe, there is no need to perform special processing on one member and the other member, and the manufacturing cost of these members Can be suppressed. In addition, it can easily cope with a change (difference) in the length of the joint pipe. Furthermore, even when the member has only a hole for the fluid passage, it is possible to cope with it, and the compatibility with existing members is excellent.

  Further, since the sealing material such as the O-ring is fitted to the outward projecting portion of the joint pipe and is held so as not to fall off, it is not necessary to pay attention to the dropping of the sealing material one by one when fixing the members. For this reason, the fixing operation | work of members can be performed efficiently. This is also one of the advantages of the present invention. Further, since the annular groove is formed in the flange, there is an advantage that the sealing material such as an O-ring can be made as small as possible (if the sealing material is disposed outside the flange, the sealing material becomes large in diameter, which increases costs. ).

(A) is a top view of embodiment, (B) is a BB view side view of (A). It is II-II sectional view taken on the line of FIG. It is a figure which shows the fixed process of a joint pipe. (A) is a cross-sectional side view of the main part before the joint pipe is fixed and the throttle body is fixed, (B) is a BB view of (A), and (C) is a side with the throttle body fixed. It is sectional drawing.

(1) Description of Structure Next, an embodiment of the present invention will be described with reference to the drawings. The present embodiment is applied to a cooling water passage connection structure provided in the intake manifold and the throttle body. The internal combustion engine of the embodiment has three cylinders. Therefore, as shown in FIG. 1, the intake manifold 1 includes three branch pipes 2, and the three branch pipes 2 are gathered in one surge tank 3. ing. Therefore, the surge tank 3 is a collecting portion, and a resin throttle body 5 is fixed to the front surface of the surge tank 3 with screws 6.

  In relation to the claims, in this embodiment, the intake manifold 1 is one member and the throttle body 5 is the other member. A flange 2 a is provided at the end of the branch pipe 2 in the intake manifold 1, and the flange 2 a is fixed to the cylinder head 7.

  The throttle body 5 is formed with an intake passage 7 that opens forward and backward, and a valve body (not shown) is arranged in the intake passage 8. The opening degree of the valve body is controlled by an electric motor (not shown). Further, on the front surface of the throttle body 5, a cylindrical portion 5 a that connects the intake hose 9 is projected. A flange 5 b is provided at the rear end of the throttle body 5, and the flange 5 b is fixed (fastened) to the surge tank 3 with a plurality of screws 6.

  The intake manifold 1 is made of resin and integrated by stacking and welding two parts. As schematically shown in FIG. 2, a water cooling type cooling unit 10 for cooling the EGR gas is arranged inside the surge tank 3 as an example of the cooling water passage.

  The cooling unit 10 can employ various structures such as a structure having a thin tube bent in a zigzag pattern and a structure having a large number of fins. In any case, an inlet and an outlet for cooling water are provided. In the embodiment, the inlet is opened rearward, and a rearward inflow pipe 10 provided integrally with the surge tank 3 communicates with the inlet. Needless to say, a cooling water hose 12 is connected to the inflow pipe 11. The inflow pipe 11 may be manufactured as a separate member from the surge tank 3 and fixed to the surge tank 3 by forced fitting, welding, or the like.

  An outlet 13 of the cooling unit 10 is opened toward the front, and a joint pipe 14 is connected to the outlet 13 by insertion. Therefore, the joint pipe 14 functions as an outflow pipe from which the cooling water of the cooling unit 10 flows out.

  The joint pipe 14 has a protruding portion 14 a that protrudes forward from the front surface of the surge tank 3, and the exposed portion 14 a is fitted into a cooling water passage 15 provided in the throttle body 5. As a result, the throttle body 5 is positioned. The throttle body 5 is integrally provided with a forward-facing cylinder portion 17 for connecting the cooling water hose 16. It is also possible to connect the cooling water hose 16 to the projecting portion 14a of the joint pipe 14 by forming the projecting portion 14a of the joint pipe 14 so as to be exposed to the front of the throttle body 5.

  A circular flange 18 for welding to the surge tank 3 of the intake manifold 1 by vibration or the like is integrally formed at the base of the protrusion 14 a in the joint pipe 14. An annular groove 19 is formed on the front surface of the flange 18. The annular groove 19 has a function of inserting and gripping the tip of the jig 20 when welding the flange 18 by vibration, and a function of fitting an O-ring 21 as an example of a sealing material.

  That is, when the joint pipe 14 is welded and fixed to the surge tank 3, the flange 18 can be vibrated accurately by inserting the tip of the jig 20 into the annular groove 19, while the joint pipe 14 is fixed. As shown in FIG. 4A, the O-ring 21 is fitted, and the presence of the O-ring 21 ensures that there is no water leakage between the throttle body 5 and the flange 18.

  The inner peripheral surface of the annular groove 19 coincides with the outer peripheral surface of the protruding portion 14a. For this reason, even if the O-ring 21 is displaced forward, the O-ring 21 is pushed into the annular groove 19 when the throttle body 5 is overlapped and fixed. This is one of the advantages of this embodiment. When the flange 18 is vibrated and welded to the surge tank 3 by high frequency or ultrasonic waves, a concentric group of ribs or an annular groove is formed on one or both of the mating surfaces of the flange 18 and the surge tank 3. Is preferably provided.

  In this embodiment, the joint pipe 14 is welded to the surge tank 3, but the joint pipe 14 can be fixed by forced fitting, bonding, screwing, or the like. Alternatively, it is also possible to fix the joint pipe 14 by pressing the throttle body 5 without fixing the joint pipe 14 to the surge tank 3 independently (therefore, the joint pipe 14 is merely inserted lightly into the surge tank 3). Good.)

  Further, the joint pipe 14 does not need to penetrate deeply into the surge tank 3, and the inward penetration dimension into the surge tank 3 can be arbitrarily set depending on the structure of the cooling unit 10. When the fluid is exhaust gas, a gasket made of an inorganic material may be used as the sealing material.

  Further, the cooling water passage provided in the surge tank 3 is not limited to the cooling unit 10, and a heating unit for preventing freezing of moisture condensed in the surge tank 3 may be provided.

  The present invention can be embodied in various ways. For example, the application target is an oil passage connection point between the oil filter and the chain cover (or cylinder block), a connection point between the exhaust manifold and the catalytic converter, a connection point between the exhaust pipe and the exhaust turbocharger, etc. It can be widely applied to locations where gaskets are interposed. Needless to say, the joint pipe may be made of metal. If the fixing of the flange to one member is not welding or adhesion, it is possible to secure a seal between the flange and one member by forming an annular groove on the back of the flange and fitting a sealing material into this is there.

  The present invention is actually applicable to connection of flow paths at various locations in an internal combustion engine. Therefore, it can be used industrially.

1 Intake manifold (one member)
3 Surge tank 5 Throttle body (other member)
6 Screw as an example of fastener 10 Cooling unit 13 Outlet of cooling water passage 14 Joint pipe 14a Protrusion portion of joint pipe 15 Cooling water passage of throttle body 18 Flange 19 Annular groove 20 Jig for welding 21 As an example of sealing material O-ring

Claims (1)

A joint pipe having an outward projecting portion is provided on one of two members that overlap each other, and the other member is fitted into the outward projecting portion of the joint pipe to fix both members, thereby In the internal combustion engine connecting the fluid passage of the other member and the joint pipe,
The joint pipe is a member different from the one member, and a flange that overlaps the surface of the one member is formed on the outward projecting portion of the joint pipe, and the flange is opened toward the other member. An annular groove is formed, and a sealing material pressed by the other member is fitted into the annular groove.
Flow path connection structure for an internal combustion engine.

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