Support balanced common rail injector fastening structure

Abstract

The application provides a support balance type common rail injector fastening structure, a positioning ring is sleeved on a rod body positioning section of the common rail injector, the common rail injector rod body is inserted into an injector mounting hole of a cylinder head combined shell, a chamfer surface of a lower surface of the positioning ring is abutted against a hole chamfer of the injector mounting hole, a lower stop shoulder surface of the rod body positioning section is abutted against a lower surface of the positioning ring, a first plane formed by an upper surface of a support is coplanar with a second plane formed by an upper surface of the positioning ring and is perpendicular to an axial line of the common rail injector, a right convex part in an arc surface shape of a lower surface of a right end of the support is abutted against the second plane to form a line contact, a left convex part in an arc surface shape of a lower surface of a left end of the support is abutted against the first plane to form a line contact, the support is fixed with the cylinder head combined shell through screwing, and a bolt is parallel to the axial line of the common rail injector. The application has the advantages of simple structure, convenient disassembly and assembly, easy adjustment and operation, and reliable fastening of the common rail injector.

Description

Technical Field

[0001] This invention belongs to the field of engine technology, and in particular relates to the fastening structure of a support-balanced common rail injector. Background Technology

[0002] The fuel injector is a crucial component of an engine, a precision device requiring extremely high machining accuracy. Its function is to atomize diesel fuel into fine particles and distribute them throughout the combustion chamber, ensuring thorough mixing with air to optimize combustion performance. This effectively improves the combustion efficiency of the diesel engine while reducing the thermal load on related components within the combustion chamber. The fuel injector is one of the key components determining the engine's power, fuel economy, and ensuring its normal operation.

[0003] In the existing technology, common methods for fixing fuel injectors include:

[0004] like Figure 1 As shown in section (A), the injector is fixed to the cylinder head by a mounting plate on the injector body: the cylinder head 1a is a cast aluminum part, and the double-ended stud 4a is interference-fitted into the cylinder head. The injector 3a has an 11mm thick mounting plate 2a, and the injector is fixed to the cylinder head by the injector fixing nut;

[0005] like Figure 2 As shown in section (B), the injector is fixed by a locking nut: the cylinder head 1b is a cast iron part, and the injector 3b mounting hole has an internal thread. The injector is fixed to the cylinder head 1b by the locking nut 2b.

[0006] Based on market demands, traditional six-cylinder diesel engines need to be converted to high-pressure common rail diesel engines, and the fuel injection system needs to be changed from the original mechanical in-line pump to an electronically controlled common rail fuel injection system. The principle for determining the high-pressure common rail installation scheme is to match and install the high-pressure common rail system while minimizing changes to the original engine structure. For example... Figure 2 As shown, since the injectors used in high-pressure common rail diesel engines have an outwardly protruding electrical control plug, diesel inlet, and diesel return port, the existing fixing methods such as mounting plate and locking screw are not suitable for fixing common rail injectors. Therefore, a structural device for fixing common rail injectors needs to be designed. 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, valve cover, etc., this invention proposes a technical solution for fixing the common rail injector using a support-balanced fastening method, as follows:

[0008] A support-balanced common rail injector fastening structure is provided. The common rail injector has a rod positioning section with two axially symmetrical positioning surfaces on a cylindrical rod, and a lower shoulder surface is formed below the positioning surfaces. The key feature is that a positioning ring is fitted onto the rod positioning section of the common rail injector through its first U-shaped groove. The common rail injector rod below the positioning section is inserted into the injector mounting hole of the cylinder head assembly housing. The chamfered surface of the lower surface of the positioning ring abuts against the chamfer of the injector mounting hole. The lower plane of the positioning ring presses against the lower shoulder surface of the rod positioning section at both sides of the lower opening of the first U-shaped groove to achieve positioning. A support plate is accommodated in the support plate mounting hole of the cylinder head assembly housing.

[0009] The first plane formed by the upper surface of the support plate 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 fitted onto the common rail injector through the second U-shaped groove, and the arc-shaped right protrusion on the lower surface of the right end of the support presses against the second plane to form line contact; the arc-shaped left protrusion on the lower surface of the left end of the support presses against the first plane to form line contact; the support is bolted to the bolt mounting holes of the cylinder head assembly housing after passing through the bolt holes, the bolts are parallel to the axis of the common rail injector, and the distance between the bolts and the line contact on the right side of the support is less than the distance between the bolts and the line contact on the left side.

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

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

[0013] Furthermore, the first U-shaped groove of the positioning ring forms an upper opening and a lower opening on the upper and lower planes of the body, respectively. The two side walls of the first U-shaped groove are symmetrical and parallel with the center line of the body axis. 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 on the cylindrical surface of the body.

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

[0015] Furthermore, the lowest points of the arcuate surfaces of the left and right protrusions of the support are located in the same horizontal plane perpendicular to the axis of the bolt through hole.

[0016] Furthermore, the distance between the bolt and the line contact on the right side of the support is less than the distance between the bolt and the line contact on the left side.

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

[0018] This invention features a simple structure, easy assembly and disassembly, and convenient adjustment and operation. The common rail injector is securely fastened and reliable, meeting installation and usage requirements. The injector maintains stable performance throughout the entire operation process without any loosening. Attached Figure Description

[0019] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the existing fuel injector fastening method;

[0021] Figure 2 A schematic diagram of a common rail injector;

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

[0023] Figure 4 This 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 An explosion diagram. Detailed Implementation

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

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

[0027] Figure 2 The diagram shows a schematic of a common rail injector. As can be seen from the diagram, because the common rail injector 1 has an outwardly protruding electronic control plug 12, a diesel inlet, and a diesel return port, it cannot use the existing mounting plate or locking screw fastening method. However, the common rail injector 1 has a rod positioning section below the electronic control plug 12, which has two axially symmetrical positioning surfaces 11 on the cylindrical surface 10 as shown in the AA cross-sectional view. An upper shoulder surface and a lower shoulder surface 111 are formed above and below the positioning surfaces 11, respectively. The two positioning surfaces 11 are parallel to the rod axis, while the lower shoulder surface 111 is perpendicular to the rod axis. This invention mainly utilizes the cylindrical surface 10, positioning surfaces 11, and shoulder surfaces of the rod positioning section of the common rail injector 1, especially the lower shoulder surface 111.

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

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

[0030] Support plate 3 has a plate body with a smooth upper surface 31 and a cylindrical boss 32 fixed to the lower surface of the plate body.

[0031] The support 2 has a long strip-shaped body. The lower surfaces of the left and right ends of the body along its length are respectively formed with an arc-shaped left protrusion 21 and a right protrusion 22. The right end is also provided with a second U-shaped groove 23 that extends longitudinally and penetrates the upper surface of the body and the right protrusion 22. The second U-shaped groove 23 also has a side opening 231 on the right end face of the support 2 body. The body is also provided with a bolt through hole 24 near the second U-shaped groove 23.

[0032] Preferably, the lowest point of the arcuate surface of the left protrusion 21 and the right protrusion 22 is located in the same horizontal plane perpendicular to the axis of the bolt through hole 24.

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

[0034] Preferably, the upper surface of the support 2 also forms an avoidance slope 25 between the bolt through hole 24 and the second U-shaped groove 23, thereby avoiding the obliquely outward protruding electrical control plug 12 and reducing the overall volume of the structure.

[0035] To accommodate the fastening structure of this invention, the cylinder head assembly housing (including the cylinder head, valve chamber body, and valve cover) has also been modified and processed accordingly, with the following machining operations performed at corresponding locations on the cylinder head assembly housing:

[0036] A cylindrical boss 32 for mounting the support plate and support plate mounting holes in the plate body;

[0037] A bolt mounting hole for bolt 5 used to fasten and secure the support 2;

[0038] The injector mounting hole is used to insert and install the common rail injector 1, and the opening of the injector mounting hole is chamfered. The chamfered surface 42 formed on the periphery of the lower plane of the positioning ring 4 body is used to cooperate with the chamfered opening.

[0039] Assembly structure and working principle: The lower cylindrical boss 32 of the support plate 3 is inserted into the lower hole section of the support plate mounting hole of the cylinder head assembly housing, and the plate body of the support plate 3 is embedded in the upper hole section of the support plate mounting hole, thereby realizing the positioning function of supporting, accommodating, limiting and preventing rotation of the support plate 3, and the upper surface 31 of the plate body of the support plate 3 forms the first plane.

[0040] The positioning ring 4 is fitted onto the rod positioning section of the common rail injector 1 through the first U-shaped groove 41. The common rail injector rod below the rod positioning section is inserted into the injector mounting hole of the cylinder head assembly housing. The chamfered surface 42 of the lower surface of the positioning ring 4 abuts against the chamfer of the injector mounting hole, thus achieving coaxiality between the positioning ring 4 and the common rail injector 1 and preventing the positioning ring 4 from detaching 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 positioning section on both sides of the lower opening of the first U-shaped groove 41 to achieve a limit, restricting the common rail injector 1 from axially dislodging upward from the injector mounting hole. Furthermore, the upper surface 43 of the positioning ring 4 forms a second plane. The first plane (the upper surface 31 of the support plate 3) and the second plane (the upper surface 43 of the positioning ring 4) are located in the same horizontal plane, that is, they are coplanar.

[0041] The right end of the support 2 is fitted onto 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 arc-shaped, the right protrusion 22 and the upper surface 43 of the positioning ring 4 form line contact. 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 arc-shaped, the left protrusion 21 and the upper surface 31 of the plate body of the support piece 3 also form line contact. That is, the left and right ends of the support 2 form line contact with the corresponding lower first and second planes to provide support. The support 2 is fixed by bolts 5 passing through bolt holes 24 and screwed into the bolt mounting holes of the cylinder head assembly housing, thereby applying downward pressure to fix the support 2. The left and right ends of the support 2 press against the upper surfaces of the support plate 3 and the positioning ring 4 through line contact. Since the distance between the bolt 5 and the right side of the support 2 is less than the distance between the bolt 5 and the left side, that is, the right lever arm is less than the left lever arm, the common rail injector 1 on the right side needs to overcome a lot of resistance to come out upward, thus achieving a firm and tight fastening effect on the common rail injector 1.

[0042] The two side walls of the first U-shaped groove 41 of the positioning ring 4 correspond to the two positioning surfaces 11 of the rod positioning section for limiting the movement. Thus, the positioning ring 4 can play a certain role in preventing the common rail injector 1 from rotating after it is fixed.

[0043] The two ends of the support 2 are in line contact with the upper surfaces of the support plate 3 and the positioning ring 4, 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 principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A fastening structure for a balanced common rail injector, wherein the common rail injector has a rod positioning section with two axially symmetrical positioning surfaces formed on a cylindrical rod, and a lower shoulder surface is formed below the positioning surfaces, characterized in that... The positioning ring is fitted onto the positioning section of the common rail injector rod through its first U-shaped groove. The common rail injector rod below the positioning section is inserted into the injector mounting hole of the cylinder head assembly housing. The chamfered surface of the lower surface of the positioning ring abuts against the chamfer of the injector mounting hole. The lower plane of the positioning ring presses against the lower shoulder surface of the positioning section of the rod at both sides of the lower opening of the first U-shaped groove to achieve positioning. The support plate is accommodated in the support plate mounting hole of the cylinder head assembly housing. The first plane formed by the upper surface of the support plate 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 fitted onto the common rail injector through the second U-shaped groove, and the arc-shaped right protrusion on the lower surface of the right end of the support presses against the second plane to form line contact; the arc-shaped left protrusion on the lower surface of the left end of the support presses against the first plane to form line contact; the support is bolted to the bolt mounting holes of the cylinder head assembly housing after passing through the bolt holes, and the bolts are parallel to the axis of the common rail injector; The support has a plate body, the smooth upper surface of the plate body forms a first plane, and a cylindrical boss is fixed to the lower surface of the plate body. The cylinder head assembly housing is provided with a cylindrical boss for mounting the support plate and a support plate mounting hole in the plate body. The lower cylindrical boss of the support plate is inserted into the lower section of the support plate mounting hole, and the plate body of the support plate is embedded in the upper section of the support plate mounting hole, thereby realizing the positioning function of supporting, accommodating, limiting and preventing rotation of the support plate. The lowest points of the arc surfaces of the left and right protrusions of the support are located in the same horizontal plane perpendicular to the axis of the bolt hole.

2. The fastening structure for the balanced common rail injector as described in 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 and lower planes of the body, respectively. The two side walls of the first U-shaped groove are symmetrical and parallel with the center line of the body axis. 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 on the cylindrical surface of the body.

3. The fastening structure for the balanced common rail injector as described in claim 1, characterized in that, The second U-shaped groove also has a side opening on the right end face of the support body.

4. The fastening structure for the support-balanced common rail injector as described in claim 1, characterized in that, The distance between the bolt and the line contact on the right side of the support is less than the distance between the bolt and the line contact on the left side.

5. The fastening structure for a balanced common rail injector as described in claim 1 or 4, characterized in that, The distance between the bolt through the hole and the right end of the support is less than one-third of the distance between the bolt through the hole and the left end of the support.

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