High-pressure-resistant plunger pair structure for diesel engine

Abstract

The utility model relates to diesel engine parts technical field, concretely disclose a kind of high-pressure-resistant plunger pair structure for diesel engine, including wear-resistant sealing assembly, wear-resistant sealing assembly includes main body, connecting point, wear-resistant sleeve, negative pressure cavity and negative pressure ring, connecting pad is circularly arrayed below the outer surface of main body, wear-resistant sleeve is set on the outer surface of connecting pad, negative pressure cavity is set in the center inside main body, negative pressure ring is set in the inside of negative pressure cavity, and the radius of negative pressure ring is less than the radius of wear-resistant sleeve, since the original structure modification replaces wear-resistant sealing assembly, thus can effectively improve sealing performance, enhance wear resistance and fatigue resistance, high-pressure injection working condition, prolong service life.

Description

Technical Field

[0001] This utility model relates to the field of diesel engine parts, and in particular to a high-pressure resistant plunger assembly structure for diesel engines. Background Technology

[0002] The plunger assembly is a core precision component in the diesel engine fuel injection system. Its performance directly determines the diesel engine's power output, fuel economy, and emissions. As diesel engines develop towards higher power, higher compression ratio, and lower emissions, the injection pressure of the fuel injection system continues to increase. Existing plunger assemblies have the following technical defects under high-pressure conditions: 1. Insufficient sealing performance: Traditional plunger assemblies achieve sealing through a precise fit between the outer circle of the plunger and the inner hole of the plunger sleeve. Under high pressure, fuel leakage is prone to occur in the gap between the plunger and the plunger sleeve, which not only reduces injection efficiency but also causes accelerated wear on the mating surfaces due to the scouring effect of leaked fuel. 2. Limited wear resistance: During the reciprocating motion of the plunger, the mating surfaces are subjected to high-frequency friction and impact. Existing materials (such as GCr15 bearing steel) are difficult to meet the long-term use requirements under high pressure and high temperature conditions, and are prone to failure phenomena such as scratches and roughening. 3. Poor fatigue resistance: Under high pressure cyclic load, stress concentration is easily generated at the edge of the oil inlet hole of the plunger head and plunger sleeve, which leads to crack initiation and propagation, shortening the service life. Therefore, developing a high-pressure plunger assembly structure with excellent sealing performance, wear resistance, and fatigue resistance has become the key to solving the above problems. Utility Model Content The purpose of this invention is to provide a high-pressure resistant plunger assembly structure for diesel engines. This structure can effectively improve sealing performance, enhance wear resistance and fatigue resistance, and extend service life under high-pressure injection conditions.

[0003] To achieve the above objectives, this utility model employs a wear-resistant sealing assembly, which includes a main body, a connection point, a wear-resistant sleeve, a negative pressure chamber, and a negative pressure ring. The connection pad is arranged in a circular array on the lower outer surface of the main body, the wear-resistant sleeve is disposed on the outer surface of the connection pad, the negative pressure chamber is disposed inside the center of the main body, and the negative pressure ring is disposed inside the negative pressure chamber, with the radius of the negative pressure ring being smaller than the radius of the wear-resistant sleeve.

[0004] The wear-resistant sealing assembly further includes a lower cavity and an upper cavity. The lower cavity is disposed on the outer surface of the main body and is located below the negative pressure chamber. The upper cavity is disposed on the outer surface of the main body and is also located above the negative pressure chamber.

[0005] The wear-resistant sealing assembly further includes an upper ring gasket and a lower ring gasket. The upper ring gasket is disposed inside the upper slot, and the lower ring gasket is disposed inside the lower slot. The radii of the upper ring gasket and the lower ring gasket are the same as the radius of the wear-resistant sleeve.

[0006] The wear-resistant sealing assembly further includes a mounting cavity and a pressure detector. The mounting cavity is located inside the upper part of the main body, and the pressure detector is located inside the center of the mounting cavity, with its upper end located above the main body.

[0007] The wear-resistant sealing assembly also includes a mounting bracket, which is arranged in a hexagonal array above the main body and is perpendicular to the main body.

[0008] Beneficial effects: 1. A high-pressure resistant plunger assembly structure for a diesel engine according to this utility model, wherein the connection point is to connect the wear-resistant sleeve to the main body by welding, and the radii of the upper ring gasket and the lower ring gasket are the same as the radius of the wear-resistant sleeve. Thus, during use, the wear-resistant sleeve will prevent the main body from excessive wear while ensuring sealing.

[0009] 2. This utility model discloses a high-pressure plunger assembly structure for a diesel engine. During operation, the reciprocating motion of the plunger creates a localized low pressure within the negative pressure chamber. Due to the pressure difference between the inside and outside of the chamber, atmospheric pressure or high-pressure fuel pressure pushes the negative pressure ring, causing it to tightly adhere to the inner wall of the negative pressure chamber and the plunger sleeve. The essence of the atmospheric negative pressure effect is "utilizing the pressure inside the enclosed space to be lower than the external pressure, resulting in a squeezing force exerted by the external pressure on the enclosed boundary." This atmospheric negative pressure effect forms a self-tightening seal, filling the fitting gap, blocking the fuel leakage path, and effectively enhancing the sealing reliability under high-pressure conditions. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0012] Figure 2 This is a top view of the entire utility model.

[0013] Figure 3 This is a utility model Figure 2BB line structural cross-sectional view.

[0014] 101-Main body, 102-Connection point, 103-Wear-resistant sleeve, 104-Lower hollow groove, 105-Upper hollow groove, 106-Lower ring gasket, 107-Upper ring gasket, 108-Negative pressure chamber, 109-Negative pressure ring, 110-Installation chamber, 111-Pressure detector, 112-Mounting bracket. Detailed Implementation

[0015] Please see Figures 1-3 , Figure 1 This is a schematic diagram of the overall structure of this utility model. Figure 2 This is a top view of the entire utility model. Figure 3 This is a utility model Figure 2 The AA-line structural cross-sectional view shows that this utility model provides a high-pressure resistant plunger assembly structure for diesel engines, including the wear-resistant sealing assembly 100. The wear-resistant sealing assembly 100 includes the main body 101, the connection point 102, the wear-resistant sleeve 103, the negative pressure chamber 108, and the negative pressure ring 109. The connection point 102 is arranged in a circular array on the lower outer surface of the main body 101. The wear-resistant sleeve 103 is disposed on the outer surface of the connection point 102. The negative pressure chamber 108 is disposed inside the center of the main body 101. The negative pressure ring 109 is disposed inside the negative pressure chamber 108, and the radius of the negative pressure ring 109 is smaller than the radius of the wear-resistant sleeve 103.

[0016] In this embodiment, the main body 101 is made of 42CrMo high-strength alloy steel and is cylindrical in shape. The connection points 102 are formed by tungsten inert gas welding and are arranged in a ring on the lower outer surface of the main body 101. The wear-resistant sleeve 103 is made of silicon carbide ceramic and is tubular in shape. The negative pressure ring 109 is made of nitrile rubber and is annular in shape. It is installed in the center of the negative pressure cavity 108 by interference fit and is tightly fitted to the inner wall of the negative pressure cavity 108. The connection points 102 formed by tungsten inert gas welding can hold the wear-resistant sleeve 103 in place. The 03 is firmly connected to the main body 101 and can withstand high-frequency vibration and impact under high-pressure conditions, preventing the wear-resistant sleeve 103 from falling off. The surface hardness of the wear-resistant sleeve 103, made of silicon carbide ceramic material, is much higher than that of traditional GCr15 bearing steel, which can effectively resist friction and wear during the reciprocating motion of the plunger and significantly reduce the wear rate of the outer surface of the main body 101. The cooperation between the negative pressure chamber 108 and the negative pressure ring 109 lays the foundation for the overall sealing structure. The tight fit between the negative pressure ring 109 and the negative pressure chamber 108 can initially block fuel penetration and provide a guarantee for subsequent multi-stage sealing.

[0017] Furthermore, the wear-resistant sealing assembly 100 also includes the lower cavity 104 and the upper cavity 105. The lower cavity 104 is disposed on the outer surface of the main body 101 and is located below the negative pressure chamber 108. The upper cavity 105 is disposed on the outer surface of the main body 101 and is also located above the negative pressure chamber 108.

[0018] In this embodiment, the lower slot 104 and the upper slot 105 can effectively absorb the stress waves generated by the impact of high-pressure fuel, reduce the concentration of stress on the outer surface of the main body 101, improve the fatigue strength of the main body 101, reduce the risk of crack initiation, and the slot structure reduces the amount of material used without affecting the strength of the main body, reduces the overall weight of the wear-resistant sealing assembly 100, and reduces the inertial load during the operation of the diesel engine.

[0019] Furthermore, the wear-resistant sealing assembly 100 also includes the upper ring gasket 107 and the lower ring gasket 106. The upper ring gasket 107 is disposed inside the upper slot 105, and the lower ring gasket 106 is disposed inside the lower slot 104. The radii of the upper ring gasket 107 and the lower ring gasket 106 are the same as the radius of the wear-resistant sleeve 103.

[0020] In this embodiment, the upper ring gasket 107 and the lower ring gasket 106, made of fluororubber, have excellent oil resistance and high temperature resistance, and can work stably within a wide temperature range. The upper ring gasket 107, the lower ring gasket 106 and the wear-resistant sleeve 103 have the same radius, forming a continuous outer peripheral protective structure that completely covers the outer surface of the main body 101, preventing the main body 101 from directly contacting and rubbing against the plunger sleeve, and extending the overall wear life.

[0021] Furthermore, the wear-resistant sealing assembly 100 also includes the mounting cavity 110 and the pressure detector 111. The mounting cavity 110 is disposed above the interior of the main body 101, and the pressure detector 111 is disposed at the center inside the mounting cavity 110, with the upper end of the pressure detector 111 disposed above the main body 101.

[0022] In this embodiment, the pressure detector 111 can collect pressure data of the negative pressure chamber 108 and the surrounding area in real time, providing accurate pressure feedback for the diesel engine control system, facilitating timely adjustment of injection parameters and improving power output stability.

[0023] Furthermore, the wear-resistant sealing assembly 100 also includes the mounting bracket 112, which is arranged in a hexagonal array above the main body 101 and is also perpendicular to the main body 101.

[0024] In this embodiment, the hexagonal array of mounting brackets 112 enables rapid positioning and installation of the wear-resistant sealing assembly 100 and other plunger components. Simultaneously, the hexagonal layout ensures uniform stress distribution, allowing it to withstand sufficient pre-tightening force and preventing loosening after assembly. The "L"-shaped mounting brackets 112 evenly distribute assembly stress to the upper area of ​​the main body 101, preventing stress concentration in localized areas. The standardized mounting hole dimensions and hexagonal layout adapt to the assembly requirements of different diesel engine plunger models, eliminating the need for significant modifications to existing assembly equipment and reducing application and promotion costs.

[0025] The above-disclosed embodiments are merely preferred embodiments of the present utility model and should not be construed as limiting the scope of the present utility model. Those skilled in the art can understand that implementing all or part of the above-described embodiments and making equivalent changes in accordance with the claims of the present utility model are still within the scope of the utility model.

Claims

1. A high-pressure resistant plunger assembly structure for a diesel engine, characterized in that, The assembly includes a wear-resistant sealing component comprising a body (101), a connection point (102), a wear-resistant sleeve (103), a negative pressure chamber (108), and a negative pressure ring (109). The connection point (102) is arranged in a circular array on the lower outer surface of the body (101). The wear-resistant sleeve (103) is disposed on the outer surface of the connection point (102). The negative pressure chamber (108) is disposed inside the center of the body (101). The negative pressure ring (109) is disposed inside the negative pressure chamber (108), and the radius of the negative pressure ring (109) is smaller than the radius of the wear-resistant sleeve (103).

2. The high-pressure resistant plunger assembly structure for diesel engines as described in claim 1, characterized in that, The wear-resistant sealing assembly further includes a lower cavity (104) and an upper cavity (105), the lower cavity... (104) is disposed on the outer surface of the main body (101), and the lower slot (104) is disposed below the negative pressure chamber (108), the upper slot (105) is disposed on the outer surface of the main body (101), and the upper slot (105) is also disposed above the negative pressure chamber (108).

3. The high-pressure resistant plunger assembly structure for diesel engines as described in claim 2, characterized in that, The wear-resistant sealing assembly further includes an upper ring gasket (107) and a lower ring gasket (106), the upper ring gasket... (107) is disposed inside the upper empty groove (105), and the lower ring pad (106) is disposed inside the lower empty groove (104), and the radii of the upper ring pad (107) and the lower ring pad (106) are consistent with the radius of the wear-resistant sleeve (103).

4. The high-pressure resistant plunger assembly structure for diesel engines as described in claim 1, characterized in that, The wear-resistant sealing assembly also includes a mounting cavity (110) and a pressure detector (111). The mounting cavity (110) is located above the interior of the main body (101), and the pressure detector (111) is located at the center of the interior of the mounting cavity (110), with the upper end of the pressure detector (111) located above the main body (101).

5. The high-pressure resistant plunger assembly structure for diesel engines as described in claim 1, characterized in that, The wear-resistant sealing assembly also includes a mounting bracket (112) arranged in a hexagonal array above the body (101), and the mounting bracket (112) is also arranged perpendicularly to the body (101).

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