JP2007285213A - Press fit structure and common rail having the press fit structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide press fit structure and a common rail having the press fit structure, preventing burr or finishing agent from flowing out to a flow passage such as a fuel supply passage, without needing any special surface finishing step for preventing generation of burr with respect to an inner face of a press-fitted part. <P>SOLUTION: In structure where an orifice member 4 is press-fitted in a branched pipe part 12 of a common rail 1, a cutout part 43 is formed to an outer peripheral side corner part of a tip part of the orifice member 4, and a sealing space 5 is formed between a step part 15 of the branched pipe part 12 and the cutout part 43 in press-fitting of the orifice member 4. Foreign matters such as burr generated in the press-fitting or finishing agent are sealed in the sealing space 5 and do not flow out to the fuel supply passage. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a press-fitting structure of a press-fitting part employed in, for example, a common rail that is a component part of an internal combustion engine for automobiles, and a common rail including the press-fitting structure. In particular, the present invention relates to a countermeasure for solving a problem caused by burrs or the like that occur during press-fitting of press-fitting parts.

  Conventionally, a configuration in which a press-fit component is press-fitted into a passage or a recess formed in the press-fit component is known. For example, as disclosed in Patent Document 1 and Patent Document 2 below, there is a configuration in which an orifice member is press-fitted into a fuel outlet portion of a common rail provided in a fuel supply system of a diesel engine. This will be specifically described below.

  FIG. 6 is a cross-sectional view of a fuel outlet portion and its peripheral portion in a conventional common rail a. As shown in this figure, the common rail a includes a common rail main body b and a branch pipe portion c protruding from the common rail main body b to the outer periphery side corresponding to each injector (in FIG. 6, only one branch pipe portion c is shown. And). A pressure accumulation space d for storing high-pressure fuel is formed inside the common rail body b. On the other hand, the branch pipe portion c is formed with a branch passage f having one end communicating with the pressure accumulating space d and the other end communicating with the fuel pipe e. The fuel pipe e is integrally assembled to the common rail a by a nut g attached to a male screw formed on the outer peripheral surface of the branch pipe portion c. A cylindrical orifice member i having a small-diameter orifice passage h is fitted into the branch passage f formed in the branch pipe portion c by press-fitting. That is, the orifice member i having an outer diameter dimension slightly larger than the inner diameter dimension of the branch passage f is mounted by press-fitting. The orifice member i restricts a part of the fuel supply path, thereby suppressing the pulsation of the fuel accompanying the opening and closing of the injector and realizing a stable fuel supply operation.

  In such a configuration, when the orifice member i is press-fitted into the branch passage f of the branch pipe portion c, the inner peripheral surface of the branch passage f and the outer peripheral surface of the orifice member i slide relative to each other. A part of the inner peripheral surface of the branch passage f and a part of the outer peripheral surface of the orifice member i may be scraped off to generate burrs, which may be peeled off. Further, when the surface treatment is applied to the inner peripheral surface of the branch passage f or the outer peripheral surface of the orifice member i, the surface treatment agent may be peeled off. And this burr | flash (metal powder) and a surface treating agent may be discharged | emitted by the said orifice channel | path h, and may enter into the branch channel | path f of the branch pipe part c. In such a case, as the engine is driven, the fuel supplied from the common rail a to the injectors and foreign matters such as burrs and surface treatment agents enter the injector, and the fuel injection operation of the injector can be performed satisfactorily. It may become difficult to cause a decrease in engine output.

The following Patent Document 3 has been proposed as a means for avoiding the generation of the burr. In Patent Document 3, the inner surface of the branch passage is washed with water and degreased, and then subjected to a surface treatment with a zinc calcium phosphate treatment agent to reduce the frictional resistance when the orifice member is pressed. This prevents the generation of burrs.
JP 2002-322965 A JP 2003-49741 A JP 2004-36441 A

  However, as disclosed in Patent Document 1 and Patent Document 2 described above, in order to avoid adverse effects on the injector in the case where burrs and surface treatment agents are peeled off when the orifice member is pressed, the above press-fitting operation is performed. Later, a cleaning operation for removing these burrs and surface treatment agents from the fuel supply path is required. This necessitates a special instrument for the cleaning operation, and also complicates the manufacturing operation of the common rail.

  On the other hand, in the one disclosed in Patent Document 3, although the possibility that the burr or the surface treatment agent is peeled off is low, it is necessary to perform a special surface treatment on the inner surface of the common rail in advance. This is not preferable because it causes an increase in manufacturing steps and an increase in manufacturing costs.

  Such a problem is not limited to the press-fitting of the press-fitting component (the orifice member) at the fuel outlet portion of the common rail, and may occur similarly in other press-fitting structures. For example, when a press-fitting part (for example, a check valve) is press-fitted into a fuel passage in an engine fuel pump, or when a press-fitting part (for example, a spacer for restricting the cooling water flow path) is press-fitted into a cooling water circulation path. is there.

  The present invention has been made in view of such a point, and an object of the present invention is to prevent the occurrence of burrs or the like on the inner surface of a press-fit component (in the above-described case, the branch pipe portion of the common rail). To provide a press-fit structure capable of preventing foreign matters such as burrs and surface treatment agents from flowing out into a flow path such as a fuel supply path without requiring a special surface treatment process, and a common rail equipped with the press-fit structure. It is in.

-Principle of solving the problem-
The solution principle of the present invention taken in order to achieve the above object is to form a space for collecting and holding foreign matters such as burrs and surface treatment agents between the press-fit member and the press-fit component. At the same time, in the press-fitted state, the foreign matter is surely contained by sealing the space by a seal portion that is a contact portion between the press-fitted member and the press-fitted component.

-Solution-
Specifically, the present invention relates to a press-fitting component in which a flow passage communicating with a fluid passage is formed inside a press-fit member having a fluid passage in which a large diameter portion and a small diameter portion are formed via a stepped portion. It is premised on a press-fitting structure formed by press-fitting from the large-diameter part side to a position where it comes into contact with the step part. For this press-fit structure, a first seal portion is formed between the inner peripheral surface of the large-diameter portion of the press-fit member and the outer peripheral surface of the press-fit component that abuts on the press-fit member, while the step portion of the press-fit member and A second seal portion is formed with the tip portion of the press-fitting part that comes into contact, and an enclosure space for enclosing foreign matter is formed in a region extending between the first seal portion and the second seal portion. As described above, a cutout portion is formed in at least one of the corner portion at the front end portion of the press-fitting component and the corner portion on the outer peripheral side of the stepped portion of the press-fitted member.

  Due to this specific matter, when a press-fitting part is pressed into the large diameter part of the fluid passage formed in the press-fitted member, burrs are generated due to the relative sliding of the two parts, and the burr is peeled off or the surface is removed. When the treatment is applied, the surface treatment agent may be peeled off, but these foreign substances are at least one of the corner portion at the tip of the press-fitted part and the corner portion on the outer peripheral side of the stepped portion of the press-fit member. Is enclosed in the enclosed space obtained by forming the notch. The sealed space includes a first seal portion between the inner peripheral surface of the large-diameter portion of the press-fit member and the outer peripheral surface of the press-fit component that is in contact therewith, a stepped portion of the press-fit member, and a press-fit component that is in contact therewith. Therefore, the foreign matter in the enclosed space is not discharged into the fluid passage. For this reason, it is avoided that a foreign material is mixed in the fluid flowing through the fluid passage. For example, when applied to a fuel supply system of an internal combustion engine for automobiles, the foreign matter does not enter the injector or the like, the fuel injection operation of the injector can be maintained well, and an appropriate operating state of the internal combustion engine can be obtained. Can do.

  Moreover, the following are also mentioned as another solution means for achieving the said objective. In other words, a press-fit structure is formed by press-fitting a press-fitting part in which a flow passage communicating with the opening of the fluid passage is press-fitted into a press-fit member in which a recess having a fluid passage opening is formed at the center of the bottom. And For this press-fit structure, a first seal portion is formed between the inner peripheral surface of the concave portion of the press-fitted member and the outer peripheral surface of the press-fitting component that abuts on the press-fit member, while the bottom portion of the concave portion of the press-fit member A second seal portion is formed with the tip portion of the press-fitting component that comes into contact, and an enclosure space for enclosing foreign matter is formed in a region extending between the first seal portion and the second seal portion. As described above, a cutout portion is formed in at least one of the corner portion at the tip portion of the press-fitting component and the corner portion of the concave portion of the press-fit member. This solution means that the “large-diameter portion of the fluid passage” and the “small-diameter portion” in the above-described solution means “the recessed portion of the press-fit member” and “the fluid passage opening to the bottom of the recessed portion”, respectively. It is.

  Similarly to the case of the above-described solution means, this solution means that the foreign matter generated in the press-fitting operation is enclosed in the enclosed space, and this foreign matter is not discharged into the fluid passage. This prevents foreign matter from being mixed into the fluid flowing through the fluid passage.

  As a specific configuration for forming the enclosed space, a corner portion at the tip of the press-fitted part is cut out over the entire periphery. Thereby, it is possible to prevent foreign matter from being discharged during the press-fitting operation only by processing a part of the press-fitted part, and a highly practical configuration can be obtained.

  Moreover, the following is mentioned as a structure which can prevent reliably that a foreign material is discharged | emitted by improving the sealing performance of a 2nd seal part. An annular protrusion that surrounds the outer periphery of the flow path is formed at the tip of the press-fitting part, and the protrusion is brought into contact with the stepped part of the press-fitting member to constitute the second seal portion, while the tip of the press-fitting part The corner portion of the portion is cut out, and the enclosed space is formed from the contact position of the protrusion to the stepped portion of the press-fitted member to the cut-out portion of the press-fit component.

  In addition, an annular protrusion that surrounds the outer periphery of the flow path is formed at the tip of the press-fitting component, and this protrusion is brought into contact with the bottom of the concave portion of the press-fit member to constitute the second seal portion. The corner portion at the tip of the component is cut out, and the enclosed space is formed from the contact position of the protrusion to the bottom of the concave portion of the press-fitted member to the cut-out portion of the corner portion at the tip of the press-fitted component. .

  According to these specific matters, in the second seal portion, since the relatively small area of the tip end surface of the protrusion becomes the seal surface, it is easy to obtain high flatness of the seal surface, and high sealing performance is ensured. be able to. In addition, since the enclosed space is formed from the contact position of the protrusion to the cut-out part of the press-fitting part, all foreign matters can be collected and held even when the amount of foreign matters generated during press-fitting operation is relatively large. It is possible to form a large enclosed space, and it is possible to reliably prevent discharge of foreign matter into the fluid passage.

  As a specific application location of the press-fitting structure according to each of the above-described solving means, there is a common rail provided in the fuel supply system of the internal combustion engine. Specifically, with respect to a common rail having a common rail main body and a branch pipe portion as a press-fit member projecting from the common rail main body to the outer peripheral side corresponding to each injector, the branch pipe portion is connected to the common rail main body. A branch passage communicating with the formed pressure accumulation space is formed, and a cylindrical orifice member as a press-fitting part is attached to the inside of the branch passage by press-fitting.

  The orifice member is press-fitted in order to suppress fuel pulsation accompanying opening and closing of the injector and realize a stable fuel supply operation. If foreign matter such as burrs or surface treatment agent enters the injector together with the fuel during the press-fitting operation of the orifice member, the fuel injection operation may be adversely affected. However, according to this solution, the foreign matter is recovered and held in the enclosed space. Therefore, it is possible to prevent foreign matter from entering the injector, improve the fuel injection operation, and obtain an appropriate operating state of the internal combustion engine.

  In the present invention, an enclosed space for collecting and holding foreign substances such as burrs and surface treatment agents is formed between the press-fitted member and the press-fitted component, and a seal portion between the two places the enclosed space. A sealed space ensures that foreign matter is contained. For this reason, the foreign material generated in the press-fitting operation is collected in the enclosed space and is not discharged into the fluid passage. Therefore, for example, when applied to a fuel supply system of an automobile internal combustion engine, the foreign matter does not enter the injector or the like, the fuel injection operation of the injector can be maintained well, and an appropriate operating state of the internal combustion engine can be maintained. Obtainable.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. This embodiment demonstrates the case where this invention is applied to the common rail with which the fuel supply system of the diesel engine for motor vehicles was equipped. The common rail is for storing the fuel supplied from the high-pressure fuel pump in a high-pressure state and distributing the fuel to each injector. That is, the common rail and each injector are connected by a fuel pipe, and high pressure fuel is supplied to the injector that has performed the valve opening operation, and this fuel is supplied into the cylinder.

(First embodiment)
-Configuration of the connection between the common rail and fuel pipe-
First, the configuration of the connecting portion between the common rail and the fuel pipe will be described. FIG. 1 is a cross-sectional view of a connection portion between the common rail 1 and the fuel pipe 2. As shown in this figure, the common rail 1 is a substantially cylindrical member made of, for example, machine structural steel. The common rail main body 11 and the object protruding from the common rail main body 11 to the outer peripheral side corresponding to each injector. A branch pipe portion 12 (only one branch pipe portion 12 is shown in FIG. 1) as a press-fitting member. For example, in the case of an in-line four-cylinder engine, the branch pipe portions 12 are provided at four locations. In the case of a V-type six-cylinder engine, a common rail 1 is provided for each bank. The pipe part 12 is provided in three places.

  A pressure accumulation space 11 a for storing high-pressure fuel is formed inside the common rail body 11. On the other hand, a branch passage (fluid passage) 13 having one end communicating with the pressure accumulation space 11 a and the other end communicating with the fuel pipe 2 is formed in the branch pipe portion 12. A diameter-enlarged portion 13 a that extends in a tapered shape toward the fuel pipe 2 is formed at the outer end of the branch passage 13 (the end on the side where the fuel pipe 2 is connected). The enlarged diameter portion 13a functions as a pressure receiving seat surface with which the upstream end of the fuel pipe 2 is brought into contact. A male screw 14 is formed on the outer peripheral surface of the branch pipe portion 12.

  On the other hand, the fuel pipe 2 has a substantially spherical connecting portion 21 at the upstream end portion in the fuel flow direction (see the arrow in FIG. 1), and a pipe main body 22 extending from the connecting portion 21 toward the injector. I have. A fuel flow path 2 a is formed from the connecting portion 21 to the pipe body 22. The fuel pipe 2 is connected to the common rail 1 by a nut 3 screwed into the male screw 14 formed on the outer peripheral surface of the branch pipe portion 12. That is, a through hole 31 having a diameter slightly larger than the outer diameter of the pipe body 22 is formed in the head of the nut 3, and the nut with the pipe body 22 of the fuel pipe 2 inserted through the through hole 31. 3 is screwed into the external thread 14 on the outer peripheral surface of the branch pipe portion 12, thereby pressing the connection portion 21 of the fuel pipe 2 against the enlarged diameter portion 13 a of the branch passage 13, and thereby the branch passage 13 of the branch pipe portion 12. The fuel pipe 2 is assembled to the common rail 1 in a state where the fuel flow path 2 a of the fuel pipe 2 is communicated. Further, the abutment surface 32 of the nut 3 with respect to the connection portion 21 of the fuel pipe 2, that is, the surface 32 around the lower end portion of the through hole 31 is substantially coincident with the outer surface shape (substantially spherical shape) of the connection portion 21. It is processed into a spherical recess, and the nut 3 and the connecting portion 21 of the fuel pipe 2 are in surface contact.

  A cylindrical orifice member 4 as a press-fitting part having a relatively small-diameter orifice passage 41 at the center is fitted into the branch passage 13 formed in the branch pipe portion 12 by press-fitting. That is, the orifice member 4 having an outer diameter dimension slightly larger than the inner diameter dimension of the branch passage 13 is attached by press-fitting. By restricting a part of the fuel supply path (the branch passage 13) by the orifice member 4, pulsation of fuel accompanying opening and closing of the injector is suppressed, and a stable fuel supply operation can be realized.

-Configuration of the press-fitting portion of the orifice member 4-
Hereinafter, the configuration of the press-fitting portion of the orifice member 4 will be described in detail. FIG. 2 is an enlarged sectional view showing the press-fitted portion of the orifice member 4. FIG. 2 (a) shows a state before the press-fitting of the orifice member 4, and FIG. Shows a state after being pressed.

  As shown in FIG. 2, a step portion 15 is formed in the branch passage 13 formed in the branch pipe portion 12, and the pressure accumulation space 11 a side of the common rail body 11 has a smaller diameter than the step portion 15. The upstream small-diameter portion 16 is used. On the other hand, the fuel pipe 2 side (upper side in FIG. 2) from the step portion 15 is a downstream large diameter portion 17 having a large diameter. That is, the step portion 15 is provided with an abutting surface 18 formed of an annular plane facing the fuel pipe 2 side, and the abutting surface 18 is provided with the tip end surface of the orifice member 4 (the lower side in FIG. 2). Surface) 42 abuts.

  The orifice member 4 is made of metal (for example, carbon steel (S45C), stainless steel (SUS303), brass, etc.), and before being pressed into the branch passage 13 (downstream large diameter portion 17). In the state, the outer diameter is formed to be slightly larger than the inner diameter of the downstream large-diameter portion 17.

  The feature of this embodiment is that the corner portion at the tip of the orifice member 4 (the corner on the outer peripheral side of the downstream end in the press-fitting direction) is slightly cut out over the entire circumference. The notch 43 is formed. Specifically, the orifice member 4 is cut out at an inclination angle of about 60 ° with respect to the extending direction of the tip surface 42 of the orifice member 4 (horizontal direction in FIG. 2) to form a cutout portion 43. For this reason, in a state where the orifice member 4 is press-fitted into the large-diameter portion 17 on the downstream side of the branch passage 13 and the tip surface 42 is in contact with the contact surface 18, as shown in FIG. Between the corner portion, which is the boundary portion between the downstream large-diameter portion 17 and the contact surface 18, and the cutout portion 43 of the orifice member 4, the cross-sectional shape is substantially triangular, and the axis of the orifice member 4 is centered. An enclosed space 5 extending in the circumferential direction as a center is formed. As will be described later, the enclosure space 5 is used to enclose foreign matters such as burrs and surface treatment agents that are generated during the press-fitting operation of the orifice member 4 so that foreign matters are not discharged into the branch passage 13 and the fuel flow passage 2a. It has become.

-Press fitting work of orifice member 4-
Next, the press-fitting work of the orifice member 4 will be described. As shown in FIG. 2, the orifice member 4 is press-fitted into the downstream large-diameter portion 17 of the branch passage 13 before the fuel pipe 2 and the nut 3 are assembled to the common rail 1. During the press-fitting operation, burrs are generated due to relative sliding between the inner peripheral surface of the branch passage 13 and the outer peripheral surface of the orifice member 4, and the burrs are peeled off or the inner peripheral surface of the branch passage 13 and the orifice member 4. When the surface treatment is applied to the outer peripheral surface, the surface treatment agent may be peeled off. In the present embodiment, when such foreign matter is generated, the foreign matter is enclosed in the enclosed space 5 simultaneously with the completion of the press-fitting operation of the orifice member 4. The enclosed space 5 includes a first seal portion A configured by contacting the inner peripheral surface of the branch passage 13 and the outer peripheral surface of the orifice member 4, and the contact surface 18 of the stepped portion 15. Is sealed by the second seal portion B formed by contacting the front end surface 42 of the orifice member 4. For this reason, the foreign matter in the enclosed space 5 is not discharged to the branch passage 13 or the fuel flow path 2a. Accordingly, it is possible to prevent foreign matters from being mixed into the fuel flowing toward the injector, maintain the fuel injection operation of the injector satisfactorily, and obtain an appropriate engine operating state.

  As described above, in this embodiment, the enclosed space 5 is formed between the branch pipe portion 12 and the orifice member 4 almost simultaneously with the completion of the press-fitting operation of the orifice member 4 with respect to the downstream large-diameter portion 17 of the branch passage 13. Foreign substances such as burrs and surface treatment agents are enclosed in the enclosed space 5. For this reason, foreign matters such as burrs and surface treatment agents are discharged into the fuel supply path without requiring a special surface treatment process for preventing the occurrence of burrs on the inner surface of the branch passage 13. Can be prevented.

(Second Embodiment)
Next, a second embodiment will be described. In the present embodiment, the shape of the tip portion of the orifice member 4 is different from that of the first embodiment described above, and other configurations are the same as those of the first embodiment. Therefore, only the shape of the tip portion of the orifice member 4 will be described here.

  FIG. 3 is a diagram corresponding to FIG. 2 in the present embodiment. 3A shows a state before the orifice member 4 is press-fitted into the branch passage 13 of the branch pipe portion 12, and FIG. 3B shows the orifice member 4 in the branch passage 13 of the branch pipe portion 12. It is sectional drawing which shows the state after press-fitting.

  As shown in FIG. 3, a ring-shaped protrusion 44 formed so as to surround the outer periphery of the orifice passage 41 is formed at the distal end portion of the orifice member 4 according to the present embodiment. Further, similarly to the first embodiment, the corner portion at the tip of the orifice member 4 is formed with a notch 43 that is slightly notched around the entire periphery.

  Since the tip end portion of the orifice member 4 is formed in this way, a relatively small area of the tip end surface of the projection 44 becomes a seal surface, and it becomes easy to obtain a high flatness of the seal surface. High sealing performance can be ensured for the sealing portion B of the. Further, when the orifice member 4 is press-fitted into the branch passage 13, the tip of the projection 44 is slightly deformed (plastically deformed) by pressing against the contact surface 18 of the step portion 15. The degree of adhesion between the tip portion of the orifice member 4 and the contact surface 18 is increased, and a higher sealing performance can be obtained for the second seal portion B.

  In the present embodiment, a space is also formed between the tip end portion of the orifice member 4 and the contact surface 18 of the step portion 15 by providing the projection 44, and this space also functions as the enclosed space 5. The enclosure space 5 can be enlarged.

(Third embodiment)
Next, a third embodiment will be described. In this embodiment, the shape of the outer peripheral surface of the orifice member 4 is different from that of the first embodiment described above, and other configurations are the same as those of the first embodiment. Therefore, only the shape of the outer peripheral surface of the orifice member 4 will be described here.

  FIG. 4 is a diagram corresponding to FIG. 2 in the present embodiment. As shown in FIG. 4, the orifice member 4 according to the present embodiment has an outer diameter dimension on the common rail body 11 side (lower side in the figure) from the central part in the axial direction (vertical direction in FIG. 4). The outer diameter dimensions on the fuel pipe 2 side (upper side in the figure) are different from each other. Specifically, the outer diameter dimension on the fuel pipe 2 side is formed to be slightly larger than the inner diameter dimension of the downstream large-diameter portion 17 of the branch passage 13 as in the above-described embodiments. On the other hand, the outer diameter of the common rail main body 11 is smaller than the inner diameter of the downstream large diameter portion 17 of the branch passage 13. That is, the lower half of the outer peripheral surface of the orifice member 4 is formed as a notch 43 having a small diameter.

  For this reason, in a state where the orifice member 4 is press-fitted into the branch passage 13, a gap is formed between the notch (small diameter portion) 43 and the inner peripheral surface of the branch passage 13, and this gap is used as the enclosed space 5. Can function.

(Fourth embodiment)
Next, a fourth embodiment will be described. In the present embodiment, the shape of the step portion 15 of the branch passage 13 is different from that of the first embodiment described above. Further, the tip of the orifice member 4 in the present embodiment is not provided with a notch, and is formed as a cylindrical orifice member 4.

  FIG. 5 is a diagram corresponding to FIG. 2 in the present embodiment. As shown in FIG. 5, as a feature of the present embodiment, the stepped portion 15 of the branch passage 13 is formed with an enclosed space 5A formed by recessing the corner portion. The enclosed space 5A has a slightly recessed outer peripheral portion of the contact surface 18 constituting the step portion 15 toward the common rail main body 11 side (lower side in the figure), and an inner periphery of the branch passage 13. The vicinity of the step portion 15 on the surface is formed to be slightly recessed on the outer peripheral side. That is, the enclosed space 5A is a space having an L-shaped cross section and is formed over the entire circumference of the branch pipe portion 12 when the orifice member 4 is press-fitted as shown in FIG. Yes.

  Even with such a configuration, when the orifice member 4 is press-fitted into the branch passage 13, foreign matters such as burrs and surface treatment agents are collected and held in the enclosed space 5 </ b> A formed by the recessed portion, and the inside of the branch passage 13 Foreign matter is not discharged into the fuel flow path.

-Other embodiments-
Each embodiment described above demonstrated the case where this invention was applied to the common rail with which the fuel supply system of the diesel engine for motor vehicles was equipped. The present invention is not limited to this, and can also be applied as a press-fitting structure for other press-fitting parts. For example, the present invention can be similarly applied to a delivery pipe provided in a fuel supply system of an automobile gasoline engine. In addition, when a press-fitting part is press-fitted into a fuel passage in an engine fuel pump, or in a cooling water circulation path. For example, when press-fitting parts are press-fitted into the case.

It is sectional drawing which shows the connection part of the common rail and fuel pipe in 1st Embodiment. FIGS. 2A and 2B are cross-sectional views showing a press-fitting operation of an orifice member, FIG. 2A shows a state before press-fitting the orifice member, and FIG. 2B is a cross-sectional view showing a state after press-fitting the orifice member. . It is a figure equivalent to FIG. 2 in 2nd Embodiment. It is a figure equivalent to FIG. 2 in 3rd Embodiment. It is a figure equivalent to FIG. 2 in 4th Embodiment. It is a figure equivalent to FIG. 1 in a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Common rail 11 Common rail main body 11a Accumulation space 12 Branch pipe part (press-fit member)
13 Branch passage (fluid passage)
15 Step portion 16 Upstream side small diameter portion 17 Downstream side large diameter portion (concave portion)
18 Contact surface 4 Orifice member (press-fit part)
41 Orifice passage (flow path)
42 Front end surface 43 Notch portion 44 Projection 5, 5A Enclosed space A First seal portion B Second seal portion

Claims (6)

For a press-fit member having a fluid passage in which a large-diameter portion and a small-diameter portion are formed via a step portion, a press-fitting component in which a flow path communicating with the fluid passage is formed is stepped from the large-diameter portion side. In the press-fitting structure formed by press-fitting to the position that contacts the part,
The first seal portion is formed between the inner peripheral surface of the large-diameter portion of the press-fit member and the outer peripheral surface of the press-fit component that contacts the press-fit member, while the step portion of the press-fit member and the press-fit component that touches the stepped portion A second seal part is formed between the first seal part and a sealing space for enclosing foreign matter is formed in a region extending between the first seal part and the second seal part. As described above, a press-fitting structure is characterized in that a notch is formed in at least one of the corner part at the tip of the press-fitting part and the corner part on the outer peripheral side of the stepped part of the press-fitted member. In the press-fitting structure formed by press-fitting a press-fitting component having a flow passage communicating with the opening of the fluid passage formed therein into a press-fitting member in which a concave portion in which a fluid passage opens is formed at the center of the bottom,
The first seal portion is formed between the inner peripheral surface of the concave portion of the press-fitted member and the outer peripheral surface of the press-fitting component that abuts on the press-fitting member. A second seal portion is formed between the front end portion and an enclosure space for enclosing foreign matter is formed in a region extending between the first seal portion and the second seal portion. The press-fitting structure is characterized in that a notch is formed in at least one of the corner portion at the tip of the press-fitting component and the corner portion of the concave portion of the press-fitted member. In the press-fitting structure according to claim 1 or 2,
The press-fitting structure is characterized in that the enclosed space is formed by cutting a corner portion at the tip of the press-fitting part over the entire periphery. In the press-fit structure according to claim 1,
An annular protrusion is formed around the outer periphery of the flow path at the tip portion of the press-fitting component, and the second seal portion is configured by contacting the protrusion with the stepped portion of the press-fit member. The corner of the tip of the press-fitted part is cut out,
The press-fitting structure, wherein the enclosed space is formed from a contact position of the protrusion to the stepped portion of the press-fitted member to a notch portion of the press-fitted component. In the press-fitting structure according to claim 2,
An annular protrusion that surrounds the outer periphery of the flow path is formed at the tip of the press-fitting component, and the second seal portion is configured by the protrusion coming into contact with the bottom of the concave portion of the press-fit member. The corner of the tip of the press-fitted part is notched,
The press-fitting structure, wherein the sealed space is formed from a position where the protrusion contacts the bottom of the concave portion of the press-fitted member to a cut-out portion of the press-fitted component. A common rail comprising the press-fitting structure according to any one of claims 1 to 5 and provided in a fuel supply system of an internal combustion engine, the common rail main body, and an outer periphery corresponding to each injector from the common rail main body A branch pipe portion as a press-fitting member protruding to the side,
A branch passage communicating with a pressure accumulating space formed in the common rail main body is formed in the branch pipe portion, and a cylindrical orifice member as a press-fitting part is fitted into the branch passage by press-fitting. Common rail characterized by that.

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