An oil injector with static leakage structure

Abstract

The utility model relates to a kind of common rail oil atomizers with static leakage structure, contain oil atomizer body, control valve seat, control valve couple, needle valve assembly and needle valve body, innovation is in: middle hole pressure accumulation chamber is equipped in oil atomizer body, for accommodating control valve couple and needle valve assembly;Control valve couple as only static leakage couple, by control valve sleeve and clearance cooperation control valve stem is formed, control valve sleeve is built in and includes the static oil return passage of first inclined oil hole, first vertical oil return hole and annular groove, cooperate the second oil return through hole on control valve seat high-pressure sealing surface, form specific fuel leakage backflow path.Compared with traditional 2000bar common rail oil atomizer, static leakage couple reduces, fuel leakage amount is greatly reduced, effectively reduce fuel consumption, reduce carbon emission, while improving oil atomizer reliability and service life.Middle hole pressure accumulation chamber can reduce injection pressure fluctuation, improve average effective injection pressure and multiple injection precision.Oil atomizer body and needle valve body structure simplification, reduce processing difficulty and manufacturing cost.

Description

Technical Field

[0001] This utility model belongs to the field of internal combustion engine injector design technology, and particularly relates to an injector with a static leakage structure. Background Technology

[0002] Among the many components of an internal combustion engine, the fuel injector plays a crucial role, and its performance directly affects the overall performance of the engine. Currently, mainstream fuel injectors in China have certain technical limitations. Their maximum injection pressure can only reach 2000 bar, which is insufficient to meet the demands of internal combustion engines for higher injection pressures to improve combustion efficiency. More importantly, these injectors employ a dual-part static leakage structure. On one hand, there is high-pressure fuel static leakage between the injector assembly and the control valve assembly; on the other hand, there is also high-pressure fuel leakage between the control valve assembly and the injector assembly. These two leakage structures not only lead to fuel waste and increased fuel consumption, but also adversely affect engine emissions, making carbon emissions difficult to control effectively. Furthermore, the existing injector body uses a long, narrow oil passage and various intersecting holes. This complex design significantly increases the difficulty of manufacturing, resulting in high manufacturing costs and limiting the product's promotion and application. Therefore, upgrading fuel injector technology is urgently needed. Summary of the Invention

[0003] To address the problems existing in the prior art, this utility model provides an injector with a static leakage structure.

[0004] This utility model is implemented as follows: an injector with a static leakage structure includes an injector body, a control valve seat, a control valve assembly, a needle valve assembly, and a needle valve body. The feature is that the injector body is provided with a central accumulator chamber, which accommodates the control valve assembly and the needle valve assembly. The control valve assembly constitutes the only static leakage assembly of the injector, including the control valve sleeve and the control valve stem that is clearance-fitted with the guide hole of the control valve sleeve; The control valve sleeve is provided with a static oil return channel that runs through its interior. The static oil return channel includes: a first oblique oil return hole opened on the chamfered surface at the lower end of the guide hole; a first vertical oil return hole that passes through the minor diameter of the valve sleeve and the guide hole, with its lower end intersecting the first oblique oil return hole and its upper end connecting to the first annular groove on the large end face of the valve sleeve. The control valve seat is press-fitted into the inner hole at the upper end of the injector body. Its bottom high-pressure sealing surface is in sealing fit with the large end face of the valve sleeve, and a second return oil through hole is provided on the high-pressure sealing surface. After fuel leaks from the fit gap between the control valve stem and the guide hole, it flows sequentially through: a first oblique return oil hole opened on the chamfered surface at the lower end of the guide hole; a first vertical return oil hole that is connected to the first oblique return oil hole; a first annular groove on the large end face of the valve sleeve; the second return oil through hole on the high-pressure sealing surface of the control valve seat; and finally flows into the receiving cavity of the control valve seat and enters the return oil system.

[0005] Further preferably, the two ends of the control valve stem are spherical structures: the upper end has a first spherical structure located inside the control cavity; the lower end has a second spherical structure that contacts the needle valve stem plane of the needle valve assembly; the end face of the small diameter of the first spherical structure has a first chamfer of no more than 0.3 mm; and the intersection of the second spherical structure and the outer diameter of the guide section has a second chamfer.

[0006] In a further preferred embodiment, the control valve sleeve has a two-stage outer diameter structure: the lower valve sleeve minor diameter is located inside the accumulator chamber; the upper second major diameter is guided and fitted with the upper inner hole of the injector body; the upper end face of the second major diameter forms a first sealing ring surface and a second sealing ring surface through a first annular groove; the lower end of the control valve sleeve is provided with a sealing surface that fits against the needle valve assembly.

[0007] In a further preferred embodiment, the receiving cavity of the control valve seat is provided with a sealing conical surface; the receiving cavity is connected to the second return oil passage through the transition conical surface; and the outer diameter of the control valve seat is guided and matched with the inner hole at the upper end of the injector body.

[0008] In a further preferred embodiment, the upper end of the injector body is symmetrically provided with oil return channels on both sides: the left channel includes: a first inclined oil hole starting at the end of the threaded hole and a first vertical oil return hole intersecting the first inclined oil hole; the right channel includes: a second inclined oil hole starting at the inner end face annular groove and a second vertical oil return hole intersecting the second inclined oil hole; the upper ends of the first vertical oil return hole and the second vertical oil return hole are connected to the two oil return grooves.

[0009] A further preferred embodiment has a stepped central bore volume chamber within the needle valve body, which accommodates the needle valve assembly and has no oblique oil passages or oil reservoir structures; the needle valve body is fitted to the injector body via its lower end face.

[0010] A further preferred embodiment has a connecting structure inside the control valve sleeve: the upper end of the guide hole is a hollow hole, which forms a control cavity with the control valve stem; the upper end of the hollow hole is connected to the oil outlet throttling hole; and the small diameter side of the valve sleeve is provided with an oil inlet throttling hole.

[0011] More preferably, when the control valve stem is at the bottom dead center, the lower end of its guide section is submerged in the guide hole of the control valve sleeve by at least 0.3 mm.

[0012] More preferably, the valve screw is provided with a dynamic oil return channel that runs through its interior, including: a second annular groove communicating with the receiving cavity; a vertical hole that runs through the second annular groove; and a transverse hole that connects the vertical hole and the annular volume cavity.

[0013] A further preferred embodiment includes a dynamic return path: when the injector is energized, fuel flows from the control chamber through the outlet throttle orifice into the receiving chamber of the control valve seat, and then sequentially passes through: the second annular groove of the valve screw, the vertical hole, the horizontal hole, the annular volume cavity formed by the small outer circle of the valve screw and the inner hole of the injector body, the first oblique oil hole and the first vertical return oil hole on the left side of the injector body, the second vertical return oil hole and the second oblique oil hole on the right side of the injector body; the inner end face annular groove, and finally flows back to the fuel tank through the left return oil hole.

[0014] The advantages and technical effects of this utility model are as follows: The technical effects of this utility model are mainly reflected in the following three aspects. Through structural innovation and optimized design, the dual goals of performance improvement and cost reduction are achieved: 1. Significantly reduces static fuel leakage, improving fuel efficiency and environmental friendliness. Traditional 2000bar common rail injectors typically have two static leakage components (such as the control valve component and the needle valve component), resulting in significant static leakage. This invention retains only the control valve component as the sole static leakage component. Leakage is controlled through the clearance fit between the control valve stem and the control valve sleeve. Combined with a carefully designed static return oil channel (including oblique return oil holes, vertical return oil holes, and annular grooves), static leakage is significantly reduced under the same pressure. This improvement directly reduces engine fuel consumption and carbon emissions. Furthermore, by eliminating one component, it enhances the injector's reliability and lifespan.

[0015] 2. Optimize the central accumulator structure to reduce pressure fluctuations and improve fuel injection accuracy. The injector body adopts a large-diameter accumulator chamber (Q1) design, which has a large volume and can effectively buffer high-pressure fuel fluctuations during injection, reduce pressure loss at the nozzle end, and thus improve the average effective injection pressure. Traditional injectors, due to their long and narrow fuel supply channels, are prone to pressure fluctuations during injection, resulting in uneven fuel injection volume due to differences in the intervals between multiple injections. However, the large-diameter structure of this invention stabilizes the pressure through energy storage, significantly improving the accuracy of multiple injections, and is especially suitable for high-frequency, multi-stage injection requirements.

[0016] 3. Simplify the structure and processing technology to reduce manufacturing costs. The injector body eliminates the elongated oil passage structure, and the needle valve body adopts a stepped central bore volume chamber (Q2) design without inclined oil passages or oil reservoirs. The needle valve assembly is accommodated and fuel is guided solely through the stepped central bore. The high-pressure sealing surface of the control valve seat directly seals with the large end face of the control valve sleeve, eliminating the need for a support ring or sealing ring, resulting in a simpler structure. These improvements significantly reduce machining difficulty (such as reducing inclined hole machining and complex cavity forming processes), shorten the production cycle, and, due to the reduced number of components and simplified structure, significantly lower manufacturing costs, thereby enhancing market competitiveness.

[0017] In summary, this utility model achieves significant results in reducing leakage, stabilizing injection pressure, and improving accuracy and reliability through innovative static leakage structure, optimized central hole pressure storage, and simplified structural design. It also takes into account environmental protection and economy, and is suitable for high-pressure, high-precision common rail injection systems. Attached Figure Description

[0018] Figure 1 Injector assembly diagram of this utility model Figure 2 Figure of the fuel injector body for implementation of this patent Figure 3 Enlarged view of a portion of the control valve section Figure 4 The control valve stem implemented in this patent Figure 5 Control valve sleeve implemented for this patent Figure 6 Valve seat for implementation of this patent In the figure, 1-injector body, 11-upper inner hole, 12-first inclined oil hole, 13-second vertical oil return hole, 14-second inclined oil hole, 15-third vertical oil return hole, 16-inner end face annular groove, 17-oil return groove, 18-lower end face, 19-left side oil return hole, Q1-middle hole accumulator chamber; 2-Control valve assembly, 21-Control valve sleeve, 211-Inlet throttle hole, 212-Outlet throttle hole, 213-Small diameter of valve sleeve, 214-Second large diameter, 215-First annular groove, 216-Guide hole, 217-Empty knife hole, 218-Chamfered surface, 23-Static return oil channel, 231-First oblique return oil hole, 232-First vertical return oil hole; 22-Control valve stem, 221-Small diameter end, 222-First chamfer, 223-First spherical structure, 224-Guide section, 225-Second spherical structure, 226-Second chamfer; 3-Control valve seat, 31-Sealing cone surface, 32-Transition cone surface, 33-Upper end face, 34-High pressure sealing surface, 35-Second oil return through hole, 36-Outer diameter, Q5-Receiving cavity; 4-Valve screw, 41-Second annular groove, 42-Vertical hole, 43-Transverse hole, Q6-Annular volume cavity; 5-Needle valve assembly, 51-Needle valve stem; 6-Needle valve body; Q2-Stepped central bore volume chamber; Q3-Control chamber; Q4-Return oil volume chamber. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this utility model.

[0020] like Figure 1 As shown, this embodiment discloses an injector with a static leakage structure, which mainly includes injector body 1, control valve seat 3, control valve assembly 2, needle valve assembly 5, needle valve body 6 and valve screw 4, etc. Its injection pressure can reach 2000 bar. By optimizing the static leakage structure and the central hole pressure storage design, the technical effects of low leakage, low pressure fluctuation and low processing difficulty are achieved.

[0021] The overall structure and assembly relationship of this utility model The injector body 1 has a central accumulator chamber Q1, which is a relatively large volume cavity used to accommodate the control valve assembly 2 and the needle valve assembly 5, serving to buffer high-pressure fuel and reduce pressure fluctuations during injection. The control valve seat 3 is press-fitted into the upper inner hole 11 of the injector body 1, and its bottom high-pressure sealing surface 34 is in sealing fit with the large end face of the control valve sleeve 21 in the control valve assembly 2; the valve screw 4 is pressed against the upper end of the control valve seat 3 to fix the control valve seat 3. The needle valve body 6 is attached to the lower end face of the injector body 1 through its lower end face 18, and has a stepped central volume cavity Q2 inside, used to accommodate the needle valve assembly 5 and guide fuel flow.

[0022] The structure and static leakage channel of the control valve assembly 2 in this utility model: The control valve assembly 2 is the only static leakage assembly of this injector. It consists of a control valve sleeve 21 and a control valve stem 22. The two are fitted together to control the static leakage.

[0023] The structure of the control valve sleeve 21 is as follows: Figure 5 As shown, the control valve sleeve 21 has a two-stage outer diameter structure: the lower end is the valve sleeve minor diameter 213, which is located in the accumulator chamber Q1 of the injector body 1; the upper end is the second major diameter 214, which is guided and matched with the upper inner hole 11 of the injector body 1 to ensure the axial positioning accuracy of the control valve sleeve 21.

[0024] The control valve sleeve 21 has a guide hole 216 at its center for clearance fit with the control valve stem 22; the upper end of the guide hole 216 is a hollow hole 217, which together with the control valve stem 22 forms the control chamber Q3; the upper end of the hollow hole 217 is connected to the oil outlet throttle hole 212 for controlling the flow rate of fuel from the control chamber Q3; the small diameter 213 of the control valve sleeve 21 has an oil inlet throttle hole 211 on its side for introducing high-pressure fuel into the control chamber Q3.

[0025] The static oil return channel 23 of the control valve sleeve 21 is a key structure for static leakage, specifically including: a first oblique oil return hole 231: opened on the 20° chamfered surface 218 at the lower end of the guide hole 216, with a diameter not less than φ0.5mm; a first vertical oil return hole 232: penetrating the valve sleeve minor diameter 213 of the control valve sleeve 21 and the guide hole 216, with its lower end intersecting the first oblique oil return hole 231, and its upper end connecting to the first annular groove 215 on the large end face of the control valve sleeve 21. The first annular groove 215 divides the large end face of the control valve sleeve 21 into a first sealing ring surface and a second sealing ring surface, used for sealing and cooperating with the high-pressure sealing surface 34 of the control valve seat 3; the lower end of the control valve sleeve 21 is provided with a sealing surface 219 that fits against the needle valve assembly 5.

[0026] The structure of the control valve stem 22 is as follows: Figure 4 As shown, the control valve stem 22 is a stepped cylindrical short rod with spherical structures at both ends: The upper end is provided with a first spherical structure 223, which is located in the control cavity Q3 and contacts the plane to achieve self-positioning adjustment; the end face of the small diameter end 221 where the first spherical structure 223 is located is provided with a first chamfer 222 of no more than 0.3mm to reduce stress concentration.

[0027] The lower end is provided with a second spherical structure 225, which contacts the needle valve rod 51 of the needle valve assembly 5 to realize motion transmission; a second chamfer 226 is provided at the intersection of the second spherical structure 225 and the outer diameter of the guide section 224 to avoid interference.

[0028] The guide section 224 of the control valve stem 22 is clearance-fitted with the guide hole 216 of the control valve sleeve 21 to form a static leakage gap. When the control valve stem 22 is at the bottom dead center, the lower end of its guide section 224 is recessed into the guide hole 216 of the control valve sleeve 21 by at least 0.3 mm to prevent the movement of the needle valve assembly 5 from being obstructed.

[0029] The structure of control valve seat 3: as follows Figure 6 As shown, a receiving cavity Q5 is provided at the center of the upper end of the control valve seat 3. A sealing cone surface 31 is provided inside the receiving cavity Q5 for cooperating with the sealing ball to achieve dynamic sealing. The upper part of the receiving cavity Q5 is connected to the upper end surface 33 of the control valve seat 3 through a transition cone surface 32.

[0030] The bottom end of the control valve seat 3 is a high-pressure sealing surface 34, which seals against the large end face of the control valve sleeve 21. A second return oil through hole 35 with a diameter not less than φ0.8mm is provided on the high-pressure sealing surface 34. Its upper outlet communicates with the transition cone surface 32, and its lower inlet is located within the center of the first annular groove 215 of the control valve sleeve 21. The outer diameter 36 of the control valve seat 3 is guided and fitted with the upper inner hole 11 of the injector body 1 to ensure assembly accuracy.

[0031] The return oil passage of injector body 1: as follows Figure 2As shown, symmetrical return channels are provided on both sides of the upper end of the injector body 1 to guide statically and dynamically leaked fuel back to the fuel tank: Left oil return channel: includes a first inclined oil hole 12 starting at the end of the threaded hole, and a second vertical oil return hole 13 intersecting the first inclined oil hole 12; Right-side oil return channel: includes a second inclined oil hole 14 starting at the inner end face annular groove 16, and a third vertical oil return hole 15 intersecting the second inclined oil hole 14.

[0032] The upper ends of the second vertical oil return hole 13 and the third vertical oil return hole 15 are connected to the two oil return grooves 17, forming a convergence area for the oil return path.

[0033] Structure of needle valve body 6: The needle valve body 6 has a stepped central bore volume chamber Q2 to accommodate the needle valve assembly 5 and guide fuel flow. Unlike traditional structures, this needle valve body 6 does not have an inclined oil passage or oil reservoir structure; it achieves its function solely through the stepped central bore, reducing processing difficulty and manufacturing costs.

[0034] Dynamic oil return channel: The valve screw 4 is provided with a dynamic oil return channel that runs through its interior, including: a second annular groove 41 that communicates with the receiving cavity Q5; a vertical hole 42 that runs through the second annular groove 41; and a transverse hole 43 that connects the vertical hole 42 with the annular volume cavity Q6.

[0035] This injector includes a static return path and a dynamic return path, as detailed below: 1. Static oil return path After high-pressure fuel leaks from the gap between the control valve stem 22 and the guide hole 216 of the control valve sleeve 21, it flows sequentially through: the first oblique return oil hole 231 of the lower chamfered surface 218 of the guide hole 216 of the control valve sleeve 21; the first vertical return oil hole 232 that communicates with the first oblique return oil hole 231; the first annular groove 215 of the large end face of the control valve sleeve 21; the second return oil through hole 35 of the high-pressure sealing surface 34 of the control valve seat 3; and finally enters the receiving cavity Q5 of the control valve seat 3 and flows back to the fuel tank through the dynamic return oil path.

[0036] 2. Dynamic oil return path When the injector is energized, the control valve stem 22 is raised, and high-pressure fuel flows from the control chamber Q3 through the outlet throttle hole 212 into the receiving chamber Q5 of the control valve seat 3, and then sequentially through: the second annular groove 41 of the valve screw 4; the vertical hole 42 of the valve screw 4; the transverse hole 43 of the valve screw 4; the annular volume cavity Q6 formed by the small outer circle of the valve screw 4 and the inner hole of the injector body 1; the first oblique oil hole 12 and the second vertical oil return hole 13 on the left side of the injector body 1; the third vertical oil return hole 15 and the second oblique oil hole 14 on the right side of the injector body 1; the annular groove 16 on the inner end face of the injector body 1; and finally flows back to the fuel tank through the left return hole 19.

[0037] The injector in this embodiment achieves significant technical advantages through the following design: Reduce static leakage components: Only control valve component 2 is retained as a static leakage component. Compared with the traditional structure of two static leakage components, the static fuel leakage is significantly reduced, which directly reduces fuel consumption rate and carbon emissions, while improving the reliability and service life of the injector.

[0038] Optimized medium-hole accumulator structure: The volume design of the large medium-hole accumulator chamber Q1 reduces pressure fluctuations during injection, lowers pressure loss at the nozzle end, and improves the average effective injection pressure and the accuracy of multiple injections.

[0039] Simplified structure and processing: The injector body 1 has no slender oil passage structure, and the needle valve body 6 has no oblique oil passage and oil collection groove, but only a stepped central hole structure, which reduces the processing difficulty and manufacturing cost, and enhances market competitiveness.

[0040] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An injector with a static leakage structure, comprising an injector body (1), a control valve seat (3), a control valve assembly (2), a needle valve assembly (5), and a needle valve body (6), characterized in that: The injector body (1) is provided with a central accumulator chamber (Q1), which accommodates the control valve assembly (2) and the needle valve assembly (5). The control valve assembly (2) constitutes the only static leakage assembly of the injector, including a control valve sleeve (21) and a control valve stem (22) that is clearance-fitted with the guide hole (216) of the control valve sleeve (21). The control valve sleeve (21) is provided with a static return oil passage (23) extending through its interior, the static return oil passage (23) comprising: The first oblique oil return hole (231) is opened on the chamfered surface (218) at the lower end of the guide hole (216); The first vertical oil return hole (232) passes through the small diameter (213) of the valve sleeve and the guide hole (216), and its lower end intersects with the first oblique oil return hole (231), and its upper end connects to the first annular groove (215) on the large end face of the valve sleeve. The control valve seat (3) is press-fitted into the upper inner hole (11) of the injector body (1) by the valve screw (4). Its bottom high pressure sealing surface (34) is sealed with the large end face of the valve sleeve, and a second oil return through hole (35) is provided on the high pressure sealing surface (34). After fuel leaks from the gap between the control valve stem (22) and the guide hole (216), it flows sequentially through: the first oblique return oil hole (231) opened on the chamfered surface (218) at the lower end of the guide hole (216); the first vertical return oil hole (232) that is connected to the first oblique return oil hole (231); the first annular groove (215) on the large end face of the valve sleeve; the second return oil through hole (35) on the high pressure sealing surface (34) of the control valve seat (3); and finally flows into the receiving cavity (Q5) of the control valve seat (3) and enters the return oil system.

2. The injector with a static leakage structure according to claim 1, characterized in that: The control valve stem (22) has two spherical structures at both ends: the upper end is provided with a first spherical structure (223) located in the control cavity (Q3); the lower end is provided with a second spherical structure (225) that is in plane contact with the needle valve stem (51) of the needle valve assembly (5); the end face of the small diameter end (221) where the first spherical structure (223) is located is provided with a first chamfer (222) not greater than 0.3mm; the second spherical structure (225) is provided with a second chamfer (226) at the intersection of the outer diameter of the guide section (224).

3. The injector with a static leakage structure according to claim 1, characterized in that: The control valve sleeve (21) has a two-stage outer diameter structure: the lower valve sleeve minor diameter (213) is located in the accumulator chamber (Q1); the upper second major diameter (214) is guided and fitted with the upper inner hole (11) of the injector body (1); The upper end face of the second large diameter (214) forms a first sealing ring surface and a second sealing ring surface through the first annular groove (215); the lower end of the control valve sleeve (21) is provided with a sealing surface (219) that fits with the needle valve assembly (5).

4. The injector with a static leakage structure according to claim 1, characterized in that: The control valve seat (3) has a sealing cone surface (31) in its receiving cavity (Q5); the receiving cavity (Q5) is connected to the second return oil through hole (35) through the transition cone surface (32); the outer diameter (36) of the control valve seat (3) is guided and fitted with the inner hole (11) at the upper end of the injector body (1).

5. The injector with a static leakage structure according to claim 1, characterized in that: The injector body (1) has symmetrical oil return channels on both sides of its upper end: the left channel includes a first inclined oil hole (12) starting at the end of the threaded hole and a second vertical oil return hole (13) that intersects with the first inclined oil hole (12); the right channel includes a second inclined oil hole (14) starting at the inner end face annular groove (16) and a third vertical oil return hole (15) that intersects with the second inclined oil hole (14); the upper ends of the second vertical oil return hole (13) and the third vertical oil return hole (15) are connected to the two oil return grooves (17).

6. The injector with a static leakage structure according to claim 1, characterized in that: The needle valve body (6) is provided with a stepped central hole volume cavity (Q2), which accommodates the needle valve assembly (5) and has no inclined oil passage or oil tank structure; the needle valve body (6) is attached to the injector body (1) through the lower end face (18).

7. The injector with a static leakage structure according to claim 1, characterized in that: The control valve sleeve (21) has a communication structure: the upper end of the guide hole (216) is a hollow hole (217), which forms a control cavity (Q3) with the control valve rod (22); the upper end of the hollow hole (217) is connected to the oil outlet throttling hole (212); the side of the valve sleeve small diameter (213) is provided with an oil inlet throttling hole (211).

8. The injector with a static leakage structure according to claim 1, characterized in that: When the control valve stem (22) is at the bottom dead center, the lower end of its guide section (224) sinks into the guide hole (216) of the control valve sleeve (21) by at least 0.3 mm.

9. The injector with a static leakage structure according to claim 1, characterized in that: The valve screw (4) is provided with a dynamic oil return channel that runs through its interior, including: A second annular groove (41) communicating with the receiving cavity (Q5); a vertical hole (42) penetrating the second annular groove (41); and a transverse hole (43) connecting the vertical hole (42) and the annular volume cavity (Q6).

10. The injector with a static leakage structure according to claim 8, characterized in that: It also includes dynamic oil return path: When the injector is energized, fuel flows from the control chamber (Q3) through the fuel outlet throttle hole (212) into the receiving chamber (Q5) of the control valve seat (3), and then passes through the second annular groove (41) of the valve screw (4) and the vertical hole (42) in sequence. The transverse hole (43) and the annular volume cavity (Q6) formed by the small outer circle of the valve screw and the inner hole of the injector body (1) are respectively. The first inclined oil hole (12) and the second vertical return oil hole (13) on the left side of the injector body (1), the third vertical return oil hole (15) and the second inclined oil hole (14) on the right side of the injector body (1); the inner end face annular groove (16), and finally flow back to the oil tank through the left return oil hole (19).

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