CN220101412U - Sealing structure of fuel injector and engine - Google Patents

Abstract

The utility model discloses a sealing structure of a fuel injector, which includes a fuel injector, a cylinder head, and a cylinder head cover. The top surface of the cylinder head is provided with a fuel injector hole, and the fuel injector is installed on the fuel injector. In the injector hole, the cylinder head cover is installed on the top surface of the cylinder head; it also includes a bushing and a second O-ring. A bushing is provided between the injector hole and the injector. The inner side has a clearance fit with the fuel injector; the upper end of the fuel injector hole is expanded, and a counterbore is formed at the upper end of the fuel injector hole; the upper end of the bushing is higher than the top surface of the cylinder head, and the cylinder head cover is provided with The corresponding relief groove avoids the bushing body which is higher than the top surface of the cylinder head; the counterbore cooperates with the bushing to form a second sealing groove, and the second O-ring is installed in the second sealing groove. The utility model has the advantages of good sealing performance, stable structure, and convenient disassembly and assembly.

Description

A sealing structure of a fuel injector and an engine

Technical field

The utility model relates to the technical field of fuel injector sealing, and in particular to a sealing structure of a fuel injector and an engine.

Background technique

Effective sealing of diesel engine oil is one of the prerequisites to ensure its efficient operation. The use of lubricating oil must consider sealing requirements. Currently commonly used sealing solutions include O-rings, sealing pads and interference.

The cylinder head cover is a cover on the engine cylinder head that seals the valve mechanism. When the engine is working, its inner cavity is filled with oil and gas containing atomized lubricating oil, as well as liquid lubricating oil that splashes and lubricates moving parts. These lubricating oil and oil and gas must be obtained Complete seal. Most of the existing cylinder head covers are an annular flat belt. Generally, sealing glue is applied on the sealing belt, or non-asbestos flat gaskets are used, or sealing forms such as sealing strips and paper pads are used. However, it is difficult to ensure the sealing effect. Engine oil During the normal rotation of the lubricated camshaft, oil leakage will occur near the cylinder head cover injector.

Ordinary cylinder head cover paper gaskets are cheap and easy to use. However, when the exhaust side is exposed to heat radiation or the cylinder head cover bolts are used to support the muffler or aftertreatment above, oil leakage is likely to occur due to heat or vertical vibration.

The existing patent document CN205064158U discloses a cross-chamber fuel injection structure for diesel engines, which has an annular groove on the outer wall of the middle part of the injector body. A sealing ring is nested in the annular groove, and the sealing ring is elastically pressed against the injector. on the inner wall of the orifice. Although this sealing structure can prevent oil from seeping into the combustion chamber below the fuel injector from the joint surface of the fuel injector and the fuel injector hole, oil is spread all over the surface of the cylinder head, such as the cylinder head cover and cylinder head around the fuel injector hole. The joint surface seal fails, and the oil on the surface of the cylinder head will enter the injector hole. Although the oil is blocked by the sealing ring of the existing patent document CN205064158U, the oil will accumulate in the upper area of the sealing ring in the injector hole, and the cleanliness is low. . Moreover, when the fuel injector is disassembled, the sealing ring fails, and the accumulated oil will enter the combustion chamber below the fuel injector. Starting the car again will cause the illusion of burning oil, leading to misdiagnosis of car faults.

As an improvement, a special-shaped ring seal is used around the cylinder head cover. The cylinder head cover and cylinder head can be directly fitted with small deformation and reliable sealing. However, due to the four-valve arrangement, when the cylinder head cover is sealed around the injector, the cylinder head cover is not wide enough to arrange special-shaped rings or O-ring grooves.

For example, for some models, the width of the joint surface between the surface of the cylinder head cover and the periphery of the injector hole is small. The width of the joint surface of some models is only 5mm, and the diameter of the sealing ring is only 3mm. The processing accuracy is high, and because the joint surface is only 1mm wide on one side, it not only results in poor sealing effect on the joint surface, but also easily damages both sides of the sealing groove and destroys the top surface structure of the cylinder head.

The disclosure of the above background technology content is only used to assist in understanding the concepts and technical solutions of the present utility model. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above content has been disclosed on the filing date of this patent application, In this case, the above background technology should not be used to evaluate the novelty and inventiveness of this application.

Utility model content

On the one hand, the purpose of the utility model is to provide a sealing structure of a fuel injector with good sealing performance, stable structure, and easy disassembly and assembly; on the other hand, it is to provide an engine with good sealing properties of the fuel injector and cylinder head cover.

To this end, the utility model proposes a sealing structure of a fuel injector and an engine.

Preferably, the utility model may also have the following technical features:

A sealing structure for a fuel injector, including a fuel injector, a cylinder head, and a cylinder head cover. The top surface of the cylinder head is provided with a fuel injector hole, and the fuel injector is installed in the fuel injector hole. The cylinder head cover is installed on the top surface of the cylinder head; it also includes a bushing and a second O-ring. A bushing is provided between the fuel injector hole and the fuel injector. The inner side of the bushing and the fuel injector Clearance fit; the upper end of the injector hole is expanded, and a counterbore is formed at the upper end of the injector hole; the upper end of the bushing is higher than the top surface of the cylinder head, and the cylinder head cover is provided with a corresponding relief groove Avoid the bushing body that is higher than the top surface of the cylinder head; the counterbore cooperates with the bushing to form a second sealing groove, and the second O-ring is installed in the second sealing groove.

Further, after the second O-ring is extruded and deformed, the second O-ring abuts against the bushing.

Further, the distance from the side wall of the counterbore to the inner wall of the injector hole is 0.5 to 1.5 mm larger than the diameter of the second O-ring.

Further, the distance from the side wall of the counterbore to the inner wall of the injector hole is 0.5 to 1 mm larger than the diameter of the second O-ring.

Further, the height of the counterbore is smaller than the diameter of the second O-ring.

Further, the outer side of the bushing has a clearance fit with the fuel injector hole, and the clearance is smaller than the clearance between the bushing and the fuel injector.

Further, a first sealing groove is provided in the upper part of the fuel injector hole, and a first O-ring is provided in the first sealing groove.

Further, the bushing is a copper sleeve or a steel sleeve.

An engine includes the sealing structure of the above-mentioned fuel injector.

Further, a third sealing groove is provided around the bottom surface of the cylinder head cover, and a third sealing ring is provided in the third sealing groove, and the third sealing ring is used to achieve sealing between the inside and outside of the cylinder head cover.

Compared with the existing technology, the beneficial effects of this utility model include: by adding a bushing, the casting difficulty of the cylinder head is reduced, the scrap rate is reduced, and it plays a guiding transition role. At the same time, the bushing is higher than the top surface of the cylinder head. On the one hand, it can greatly It reduces the processing difficulty of the bushing. On the other hand, it cooperates with the counterbore to form a second sealing groove to avoid damage to the second O-ring. On the other hand, it prevents oil from flowing between the bushing and the injector, ensuring the injector's safety. Product disassembly and assembly cleanliness.

Description of the drawings

Figure 1 is a top view of the utility model.

Fig. 2 is a cross-sectional view along the line B-B in Fig. 1 .

Figure 3 is an enlarged view of point C in Figure 2.

Figure 4 is a bottom view of the cylinder head cover of the present invention.

Figure 5 is a structural diagram of the top surface of the cylinder head of the present utility model.

Detailed ways

The utility model will be further described in detail below with reference to the specific embodiments and the accompanying drawings. It should be emphasized that the following description is merely exemplary and is not intended to limit the scope and application of the present invention.

Non-limiting and non-exclusive embodiments will be described with reference to the following drawings, in which like reference numerals refer to like parts unless specifically stated otherwise.

As shown in Figures 1 to 5, a sealing structure of a fuel injector includes a fuel injector 1, a cylinder head 3, and a cylinder head cover 2. The top surface of the cylinder head 3 is provided with a fuel injector hole. The oil injector 1 is installed in the injector hole, and the cylinder head cover 2 is installed on the top surface of the cylinder head. It also includes a bushing 4 and a second O-ring 5. There is a bushing 4 between the injector hole and the injector 1. The casting accuracy of the injector hole is high. By adding the bushing 4, the cylinder head can be lowered. 3 casting difficulty, reducing the scrap rate. The inner side of the bushing 4 has a clearance fit with the injector 1, and the outer side has a small clearance fit with the injector hole to ensure airtightness and installation accuracy. The upper end of the fuel injector hole is expanded to form a countersunk hole 6 at the upper end of the fuel injector hole, and the overall fuel injector hole has a countersunk hole structure; the horizontal height of the upper end of the bushing 4 is higher than the top surface of the cylinder head 3 The cylinder head cover 2 is provided with a corresponding relief groove 8 to avoid the bushing body which is higher than the top surface of the cylinder head 3, so as to prevent the bushing 4 from interfering with the installation and fixation of the cylinder head cover 2. The counterbore 6 cooperates with the bushing 4 to form a second sealing groove, and the second O-ring 5 is installed in the second sealing groove. In this embodiment, the bushing 4 is higher than the top surface of the cylinder head 3. On the one hand, the processing difficulty of the bushing 4 can be greatly reduced; on the other hand, it cooperates with the counterbore 6 to form a second sealing groove to avoid damage to the second O-ring 5. If the bushing 4 is flush with the top surface of the cylinder head 3, it is difficult to process due to machining errors. If the height of the bushing 4 is lower than the top surface of the cylinder head 3, it will cause a gap in the second sealing groove. When the second O-ring is squeezed, the second O-ring deforms toward the gap and is likely to be notched. The edges (the upper edge of the bushing and the edge of the bottom of the counterbore) are cut, causing damage to the second O-ring and affecting the sealing effect.

In the above embodiment, during assembly, the fuel injector 1 and the bushing 4 are assembled to the fuel injector hole on the cylinder head 3, and then the second O-ring 5 is installed into the second sealing groove, and then the cylinder head is The cover 2 is assembled to the cylinder head 3, and the cylinder head cover 2 is used to press the second O-ring 5, so that the cylinder head 3 and the cylinder head cover 2 cooperate with the second O-ring 5 to form a sealing surface around the fuel injector 1 , prevent the oil on the top surface of the cylinder head 3 from penetrating into the injector hole, and improve the cleanliness of the disassembly and assembly of the injector 1. At the same time, preferably, after the second O-ring 5 is extruded and deformed, the second O-ring 5 contacts the outside of the bushing 4 to form another sealing surface.

Specifically, the distance from the side wall of the counterbore 6 to the inner wall of the injector hole is greater than the diameter of the second O-ring 5 by 0.5 to 1.5 mm, preferably 0.5 to 1 mm. The height of the counterbore 6 is smaller than the diameter of the second O-ring 5 .

A first sealing groove is provided in the upper part of the injector hole, and a first O-ring 9 is provided in the first sealing groove for sealing the joint surface between the bushing 4 and the injector hole.

The bushing 4 is a copper sleeve or a steel sleeve.

An engine includes the sealing structure of the above-mentioned fuel injector. Specifically, a third sealing groove is provided around the bottom surface of the cylinder head cover 2, and a third sealing ring 10 is provided in the third sealing groove. The third sealing ring 10 is used to achieve sealing between the inside and outside of the cylinder head cover 2. , to prevent the engine oil on the top surface of the cylinder head 3 from seeping out of the cylinder head cover 2.

Those skilled in the art will recognize that many variations on the above description are possible, so the examples and drawings are merely illustrative of one or more specific implementations.

Although what are regarded as exemplary embodiments of the present invention have been described and illustrated, those skilled in the art will appreciate that various changes and substitutions are possible therein without departing from the spirit of the invention. In addition, many modifications may be made to adapt a particular situation to the teachings of the invention without departing from the central concepts described herein. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but the present invention may also include all embodiments and their equivalents falling within the scope of the present invention.

Claims (10)

1. A sealing structure for a fuel injector, including a fuel injector, a cylinder head, and a cylinder head cover. The top surface of the cylinder head is provided with a fuel injector hole, and the fuel injector is installed in the fuel injector hole. , the cylinder head cover is installed on the top surface of the cylinder head; it is characterized in that: it also includes a bushing and a second O-ring, a bushing is provided between the fuel injector hole and the fuel injector, the bushing The inner side of the bushing has a clearance fit with the fuel injector; the upper end of the fuel injector hole is expanded, and a counterbore is formed at the upper end of the fuel injector hole; the upper end of the bushing is higher than the top surface of the cylinder head, and the cylinder head cover is provided with There is a corresponding relief groove to avoid the bushing body that is higher than the top surface of the cylinder head; the counterbore cooperates with the bushing to form a second sealing groove, and the second O-ring is installed in the second sealing groove. . 2. The sealing structure of the fuel injector according to claim 1, characterized in that: after the second O-ring is extruded and deformed, the second O-ring abuts against the bushing. 3. The sealing structure of the fuel injector according to claim 2, characterized in that the distance from the side wall of the counterbore to the inner wall of the fuel injector hole is 0.5-1.5 mm larger than the diameter of the second O-ring. 4. The sealing structure of an injector according to claim 2, wherein the distance from the side wall of the counterbore to the inner wall of the injector hole is 0.5-1 mm larger than the diameter of the second O-ring. 5. The sealing structure of an injector according to claim 1, wherein the height of the counterbore is smaller than the diameter of the second O-ring. 6. The sealing structure of the fuel injector according to claim 1, characterized in that: the outer side of the bushing and the fuel injector hole fit with a clearance, and the clearance is smaller than the clearance between the bushing and the fuel injector. 7. The sealing structure of the fuel injector according to claim 6, characterized in that: a first sealing groove is provided in the upper part of the fuel injector hole, and a first O-shaped sealing groove is provided in the first sealing groove. lock up. 8. The sealing structure of an injector according to claim 1, wherein the bushing is a copper sleeve or a steel sleeve. 9. An engine, characterized by: comprising the sealing structure of the fuel injector according to claim 1. 10. The engine according to claim 9, characterized in that: a third sealing groove is provided around the bottom surface of the cylinder head cover, a third sealing ring is provided in the third sealing groove, and the third sealing ring is used to achieve Internal and external sealing of the cylinder head cover.