Support balance type common rail fuel injector fastening structure

Abstract

The invention provides a support balance type common-rail oil injector fastening structure which is characterized in that a positioning ring is sleeved on a rod body positioning section of a common-rail oil injector, a rod body of the common-rail oil injector is inserted into an oil injector mounting hole of a cylinder cover combined shell, and a chamfer surface of the lower surface of the positioning ring abuts against an orifice chamfer of the oil injector mounting hole; the lower plane of the positioning ring abuts against the lower blocking shoulder face of the positioning section of the rod body. A first plane formed by the upper surfaces of the supporting pieces and a second plane formed by the upper surface of the positioning ring are coplanar and are perpendicular to the axis of the common-rail oil sprayer. The right end of the support is arranged on the common rail oil sprayer in a sleeving mode, and an arc-face-shaped right protruding part on the lower surface of the right end of the support abuts against the second plane to form linear contact. An arc-surface-shaped left lug boss on the lower surface of the left end of the support is pressed against the first plane to form linear contact; the support is fixedly connected with the cylinder cover combined shell in a threaded mode, and the bolt is parallel to the axis of the common rail oil sprayer. The common-rail oil injector fastening device is simple in structure, easy to disassemble and assemble, easy to adjust and operate and reliable in common-rail oil injector fastening.

Description

Technical Field

[0001] The invention belongs to the technical field of engines, and in particular relates to a fastening structure of a support-balanced common rail injector. Background Art

[0002] The fuel injector is a key component of the engine and is a precision device with very high processing accuracy. The function of the fuel injector is to atomize the diesel into finer particles and distribute them in the combustion chamber to fully mix with the air, optimize the combustion performance as much as possible, effectively improve the combustion efficiency of the diesel engine, and reduce the heat load of the relevant parts of the diesel engine combustion chamber. The fuel injector is one of the key components that determines the power and economic indicators of the engine and ensures the normal operation of the diesel engine.

[0003] In the prior art, common ways of fixing the fuel injector are:

[0004] like Figure 1 As shown in the middle (A), the fuel injector is fixed to the cylinder head through the receiving plate on the fuel injector body: the cylinder head 1a is a cast aluminum part, and the stud 4a is inserted into the cylinder head with interference fit. There is an 11mm thick receiving plate 2a on the fuel injector 3a body, and the fuel injector is fixed to the cylinder head with the fuel injector fixing nut;

[0005] like Figure 2 As shown in the middle (B) part, the injector is fixed with a locking screw sleeve: the cylinder head 1b is a cast iron part, an internal thread is made in the mounting hole of the injector 3b, and the injector is fixed to the cylinder head 1b by a locking screw sleeve 2b.

[0006] According to market requirements, the traditional six-cylinder diesel engine needs to be transformed into a high-pressure common rail diesel engine, and the fuel injection system is changed from the original mechanical inline pump to an electronically controlled common rail fuel injection system. The principle of the high-pressure common rail installation plan is to match and install the high-pressure common rail system without changing the original engine structure as much as possible. Figure 2 As shown, since the upper part of the injector used in the high-pressure common rail diesel engine has an electronic control plug, a diesel inlet port, and a diesel return port that protrude obliquely outward, the existing fixing methods through the connecting plate and the locking screw sleeve are not suitable for fixing the common rail injector. Therefore, it is necessary to design a matching structural device for fixing the common rail injector. Summary of the invention

[0007] In view of the structural characteristics of the cylinder head of a six-cylinder diesel engine, combined with the structural form of the common rail injector, and taking into account the surface structural characteristics of the valve chamber, the valve chamber cover, etc., the present invention proposes a technical solution for fixing the common rail injector by a support balanced fastening method, which is as follows:

[0008] The support-balanced common rail fuel injector fastening structure is characterized in that a rod body positioning section with two axially symmetrical positioning surfaces is formed on a cylindrical rod body of the common rail fuel injector, and a lower shoulder surface is formed below the positioning surface, and the positioning ring is sleeved on the rod body positioning section of the common rail fuel injector through its first U-shaped groove, the common rail fuel injector rod body below the rod body positioning section is inserted into the fuel injector mounting hole of the cylinder head assembly housing, and the chamfered surface of the lower surface periphery of the positioning ring is abutted against the chamfer of the orifice of the fuel injector mounting hole; the lower plane of the positioning ring presses against the lower shoulder surface of the rod body positioning section at both sides of the lower opening of the first U-shaped groove to achieve limiting; the support piece is accommodated in the support piece mounting hole of the cylinder head assembly housing;

[0009] The first plane formed by the upper surface of the support piece and the second plane formed by the upper surface of the positioning ring are coplanar and perpendicular to the axis of the common rail injector;

[0010] The right end of the support is sleeved on the common rail injector through the second U-shaped groove, and the right raised portion of the arc-shaped surface on the lower surface of the right end of the support is pressed against the second plane to form a line contact; the left raised portion of the arc-shaped surface on the lower surface of the left end of the support is pressed against the first plane to form a line contact; the support is screwed and fixed with the bolt mounting hole of the cylinder head assembly housing after the bolt passes through the bolt through the hole, the bolt is parallel to the axis of the common rail injector, and the distance between the bolt and the line contact on the right side of the support is smaller than the distance between the bolt and the line contact on the left side.

[0011] Furthermore, the support piece has a plate body, a smooth upper surface of the plate body forms a first plane, and a cylindrical boss is fixedly connected to the lower surface of the plate body.

[0012] Furthermore, the cylinder head assembly shell is provided with a cylindrical boss for mounting the support piece and a support piece mounting hole on the plate body. The lower cylindrical boss of the support piece is inserted into the lower hole section of the support piece mounting hole, and the plate body of the support piece is embedded in the upper hole section of the support piece mounting hole, thereby realizing the supporting, accommodating, limiting and anti-rotation positioning functions of the support piece.

[0013] Furthermore, the first U-shaped groove of the positioning ring forms an upper opening and a lower opening on the upper plane and the lower plane of the main body respectively, and the two side walls of the first U-shaped groove are symmetrically parallel to the center of the main body axis, and one end of the two side walls is connected by the bottom surface of the groove of the arc surface, and the other end forms a side opening located on the cylindrical surface of the main body.

[0014] Furthermore, the second U-shaped groove is also formed with a side opening on the right end surface of the support body.

[0015] Furthermore, the lowest points of the arc-shaped surfaces of the left and right raised portions of the support are located in the same horizontal plane perpendicular to the axis of the bolt through hole.

[0016] Further, the distance of the line contact between the bolt and the right side of the support is smaller than the distance of the line contact between the bolt and the left side.

[0017] Further, the distance between the bolt through hole and the right end of the support is less than one third of the distance between the bolt through hole and the left end of the support.

[0018] The invention has a simple structure, is easy to disassemble and assemble, is easy to adjust and operate, and the common rail fuel injector is reliably fastened and can meet the installation and use requirements; the fuel injector has stable performance during the entire operation process and has no looseness. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings that constitute a part of the present invention are used to provide further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 It is a schematic diagram of the fastening method of the fuel injector in the prior art;

[0021] Figure 2 It is a structural schematic diagram of a common rail injector;

[0022] Figure 3 It is a schematic diagram of the fastening structure of the present invention;

[0023] Figure 4 It is a three-dimensional schematic diagram of the assembly state of the three core components of the fastening structure of the present invention;

[0024] Figure 5 for Figure 4 Explosion diagram. DETAILED DESCRIPTION

[0025] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0026] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0027] Figure 2 The common rail injector is a schematic diagram of the structure of the common rail injector. As can be seen from the figure, the common rail injector 1 is provided with an electric control plug 12, a diesel inlet port, and a diesel return port that obliquely protrude outward, so the conventional plate fixing method and locking screw sleeve fastening method cannot be used. However, the common rail injector 1 has a rod body positioning section formed on a section of the rod body below the electric control plug 12, which forms two axially symmetrical positioning surfaces 11 on the cylindrical surface 10 as shown in the AA cross-sectional view, and an upper shoulder surface and a lower shoulder surface 111 are formed above and below the positioning surface 11, respectively. The two positioning surfaces 11 are parallel to the rod axis, and the lower shoulder surface 111 is perpendicular to the rod axis. The present invention mainly combines and utilizes the cylindrical surface 10, the positioning surface 11, and the shoulder surface of the rod body positioning section of the common rail injector 1, especially the lower shoulder surface 111.

[0028] The core components of the fastening structure of the present invention are:

[0029] The positioning ring 4 has a flat cylindrical body, and a first U-shaped groove 41 is provided on the body. The first U-shaped groove 41 forms an upper opening and a lower opening on the upper plane 43 and the lower plane of the body respectively. The two side walls of the first U-shaped groove 41 are symmetrically parallel to the center of the axis of the body. One end of the two side walls is connected by the groove bottom surface 412 of the arc surface, and the other end forms a side opening 411 located on the cylindrical surface of the body; a chamfered surface 42 is formed on the periphery of the lower plane of the body.

[0030] The support piece 3 comprises a plate body portion, wherein the plate body portion has a smooth upper surface 31 , and a cylindrical boss 32 is fixedly connected to the lower surface of the plate body portion.

[0031] The support 2 has a body in the shape of a long strip, and the lower surfaces of the left and right ends of the body in the length direction are respectively formed with a left convex portion 21 and a right convex portion 22 in the shape of an arc surface, and the right end is also provided with a second U-shaped groove 23 extending longitudinally and penetrating the upper surface of the body and the right convex portion 22 respectively, and the second U-shaped groove 23 is also formed with a side opening 231 on the right end surface of the support 2 body; the body is also provided with a bolt through hole 24 adjacent to the second U-shaped groove 23;

[0032] Preferably, the lowest points of the arc-shaped surfaces of the left protrusion 21 and the right protrusion 22 are located in the same horizontal plane perpendicular to the axis of the bolt through hole 24 .

[0033] Preferably, the distance between the bolt hole 24 and the right end of the support 2 is smaller than the distance between the bolt hole 24 and the left end of the support 2; further, the distance between the bolt hole 24 and the right end of the support 2 is less than one-third of the distance between the bolt hole 24 and the left end of the support 2. The smaller the distance between the bolt hole 24 and the right end of the support 2 relative to the distance between the bolt hole 24 and the left end of the support 2, the greater the leverage effect. For a specific analysis, please see the subsequent content.

[0034] Preferably, an avoidance slope 25 is formed on the upper surface of the support 2 between the bolt through hole 24 and the second U-shaped groove 23, so as to avoid the electric control plug 12 protruding obliquely outward, thereby reducing the overall volume of the structure.

[0035] In order to cooperate with the fastening structure of the present invention, the cylinder head assembly housing (including the cylinder head, the valve chamber body and the valve chamber cover) is also improved and processed accordingly, and the following parts are processed at the corresponding parts of the cylinder head assembly housing:

[0036] A cylindrical boss 32 for mounting the support piece and a support piece mounting hole on the plate body;

[0037] a bolt mounting hole for screwing a bolt 5 for fastening the support 2;

[0038] The fuel injector installation hole is used for inserting and installing the common rail fuel injector 1, and the fuel injector installation hole has a chamfered hole opening, and the chamfered surface 42 formed on the periphery of the lower plane of the positioning ring 4 body is used to match the chamfered hole opening.

[0039] Assembly structure and working principle: The cylindrical boss 32 at the lower part of the support piece 3 is inserted into the lower hole section of the support piece mounting hole of the cylinder head assembly housing, and the plate body of the support piece 3 is embedded in the upper hole section of the support piece mounting hole, so as to achieve the positioning functions of supporting, accommodating, limiting and preventing rotation of the support piece 3, and the upper surface 31 of the plate body of the support piece 3 constitutes a first plane;

[0040] The positioning ring 4 is sleeved on the rod body positioning section of the common rail injector 1 through the first U-shaped groove 41, and the common rail injector rod body below the rod body positioning section is inserted into the injector mounting hole of the cylinder head assembly housing. The chamfered surface 42 on the peripheral edge of the lower surface of the positioning ring 4 abuts against the chamfer of the hole of the injector mounting hole, so that the coaxial center of the positioning ring 4 and the common rail injector 1 can be achieved and the positioning ring 4 can be prevented from escaping through the side opening of the first U-shaped groove 41; the lower plane of the positioning ring 4 presses against the lower shoulder surface 111 of the rod body positioning section at both sides of the lower opening of the first U-shaped groove 41 to achieve position limiting, so as to limit the common rail injector 1 from axially escaping from the injector mounting hole upward; and the upper surface 43 of the positioning ring 4 constitutes a second plane, and the first plane (the upper surface 31 of the plate body of the support piece 3) and the second plane (the upper surface 43 of the positioning ring 4) are located in the same horizontal plane, that is, the two are coplanar.

[0041] The right end of the support 2 is sleeved on the common rail injector 1 through the second U-shaped groove 23, and the right protrusion 22 on the lower surface of the right end of the support 2 presses against the upper surface 43 of the positioning ring 4. Since the right protrusion 22 is an arc-shaped surface, the right protrusion 22 forms a line contact with the upper surface 43 of the positioning ring 4; the left protrusion 21 on the lower surface of the left end of the support 2 presses against the upper surface 31 of the plate body of the support piece 3. Since the left protrusion 21 is also an arc-shaped surface, the left protrusion 21 also forms a line contact with the upper surface 31 of the plate body of the support piece 3. That is, the left and right ends of the support 2 respectively form a line contact pressure support with the first plane and the second plane corresponding to the lower side, and the support 2 is screwed and fixed with the bolt mounting hole of the cylinder head assembly housing after the bolt 5 passes through the bolt through hole 24, so that the support 2 is pressed down and fixed, and the left and right ends of the support 2 are pressed against the upper surfaces of the support piece 3 and the positioning ring 4 respectively through line contact, and because the line contact distance between the bolt 5 and the right side of the support 2 is smaller than the line contact distance with the left side, that is, the right side force arm is smaller than the left side force arm, the common rail injector 1 on the right side wants to escape upward, and the resistance that needs to be overcome is very large, thereby achieving the firmness and tightening effect of the common rail injector 1.

[0042] The two side walls of the first U-shaped groove 41 of the positioning ring 4 are correspondingly limited to the two positioning surfaces 11 of the rod body positioning section, so that the positioning ring 4 can play a certain anti-rotation effect on the common rail injector 1 after being fixed.

[0043] The two ends of the support 2 are in line contact with the upper surfaces of the support piece 3 and the positioning ring 4, respectively, which also enhances the reliability and balance of the contact.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The fastening structure of the support-balanced common rail injector, the common rail injector has a rod body positioning section with two axially symmetrical positioning surfaces formed on a cylindrical rod body, and a lower shoulder surface is formed below the positioning surface, characterized in that: The positioning ring is sleeved on the rod body positioning section of the common rail fuel injector through its first U-shaped groove, and the common rail fuel injector rod body below the rod body positioning section is inserted into the fuel injector mounting hole of the cylinder head assembly housing, and the chamfered surface of the peripheral edge of the lower surface of the positioning ring is in contact with the chamfer of the hole of the fuel injector mounting hole; the lower plane of the positioning ring presses against the lower shoulder surface of the rod body positioning section at both sides of the lower opening of the first U-shaped groove to achieve position limiting; the support piece is accommodated in the support piece mounting hole of the cylinder head assembly housing; The first plane formed by the upper surface of the support piece and the second plane formed by the upper surface of the positioning ring are coplanar and perpendicular to the axis of the common rail injector; The right end of the support is sleeved on the common rail injector through the second U-shaped groove, and the right raised portion of the arc-shaped surface on the lower surface of the right end of the support is pressed against the second plane to form a line contact; the left raised portion of the arc-shaped surface on the lower surface of the left end of the support is pressed against the first plane to form a line contact; the support is screwed and fixed with the bolt mounting hole of the cylinder head assembly housing after the bolt passes through the bolt through hole, and the bolt is parallel to the axis of the common rail injector.

2. The support-balanced common rail injector fastening structure according to claim 1, characterized in that: The support piece has a plate body portion, a smooth upper surface of the plate body portion forms a first plane, and a cylindrical boss is fixedly connected to the lower surface of the plate body portion.

3. The support-balanced common rail injector fastening structure according to claim 2, characterized in that: The cylinder head assembly shell is provided with a cylindrical boss for mounting the support piece and a support piece mounting hole on the plate body. The cylindrical boss at the lower part of the support piece is inserted into the lower hole section of the support piece mounting hole, and the plate body of the support piece is embedded in the upper hole section of the support piece mounting hole, thereby realizing the supporting, accommodating, limiting and anti-rotation positioning functions of the support piece.

4. The support-balanced common rail injector fastening structure according to claim 1, characterized in that: The first U-shaped groove of the positioning ring forms an upper opening and a lower opening on the upper plane and the lower plane of the main body respectively. The two side walls of the first U-shaped groove are symmetrically parallel to the center of the main body axis. One end of the two side walls is connected by the groove bottom surface of the arc surface, and the other end forms a side opening located on the cylindrical surface of the main body.

5. The support-balanced common rail injector fastening structure according to claim 1, characterized in that: The second U-shaped groove is also formed with a side opening on the right end surface of the support body.

6. The support-balanced common rail injector fastening structure according to claim 1, characterized in that: The lowest points of the arc-shaped surfaces of the left and right raised parts of the support are located in the same horizontal plane which is perpendicular to the axial center line of the bolt through hole.

7. The support-balanced common rail injector fastening structure according to claim 1, characterized in that: The distance at which the bolt contacts the line on the right side of the support is less than the distance at which the bolt contacts the line on the left side.

8. The support-balanced common rail injector fastening structure according to claim 1 or 7, characterized in that: The distance between the bolt through hole and the right end of the support is less than one third of the distance between the bolt through hole and the left end of the support.

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