Plunger and barrel assembly of high-pressure fuel injection pump
By employing a sealing ring and expansion ring structure in the high-pressure fuel injection pump of the diesel engine, the problem of poor sealing of the plunger assembly under high pressure is solved, thereby achieving effective output of high-pressure fuel and reducing fuel consumption.
Patent Information
- Application Number
- CN202423324162.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2025-10-24
- Estimated Expiration
- 2034-12-31
AI Technical Summary
The plunger assembly of the existing high-pressure common rail fuel injection pump for diesel engines has poor sealing performance under 200MPa high pressure, resulting in fuel leakage and affecting oil lubrication and high-pressure pump output pressure.
The structure of sealing rings and expansion rings, combined with the design of a sealing skeleton, improves the sealing effect between the plunger sleeve and the plunger, ensuring the output of high-pressure fuel.
It improves the sealing of the fuel pump, reduces fuel leakage, ensures the output of high-pressure fuel, and reduces the loss of high-pressure fuel.
Smart Images
Figure CN223469361U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a high pressure fuel injection pump plunger pair. BACKGROUND
[0002] The diesel engine high pressure common rail fuel injection pump is mainly used for matching diesel engine and is installed on the power assembly of the bus and truck using diesel as fuel. Figure 1 As shown in the figure, the existing plunger pair includes a plunger sleeve 100', which is internally provided with a through hole 101' for penetrating the plunger 200.
[0003] The sealing mode of the existing plunger pair is gap control after matching. The gap between the outer wall of the plunger 200 and the inner wall of the through hole 101' of the plunger sleeve is required to be δ = ΦD(plunger sleeve diameter) - Φd(plunger diameter) = 4.5-6.0 μm. When the output pressure of the high pressure pump is 160 MPa, the sliding property of the plunger is ensured and the fuel is prevented from leaking downward, thereby playing a sealing role. However, when the output pressure of the high pressure pump is 200 MPa, the extremely high pressure breaks the limit of the gap sealing, causing the fuel to leak downward into the cam chamber and mix with the oil, thereby reducing the lubricating property of the oil and increasing the wear of the cam shaft. The high pressure pump operates abnormally and the output pressure of the high pressure pump decreases, which cannot ensure the fuel pressure required by the injection system. SUMMARY
[0004] The utility model solves the technical problem that the plunger pair in the prior art uses gap control for sealing and cannot adapt to the output pressure of the 200 MPa high pressure pump, and provides a high pressure fuel injection pump plunger pair.
[0005] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme:
[0006] A high pressure fuel injection pump plunger pair, characterized in that it includes a plunger sleeve, the middle part of the plunger sleeve is provided with an upper and lower through plunger hole for penetrating the plunger, the inner wall of the plunger hole is provided with a containing groove, a sealing sleeve ring is arranged in the containing groove, the sealing sleeve ring and the central axis of the plunger hole coincide, the plunger penetrates the plunger hole and the sealing sleeve ring in sequence; the both ends of the sealing sleeve ring are provided with expansion rings, the bottom of the plunger hole is provided with a sealing framework, and the sealing framework is pressed on the end part of the plunger sleeve and the expansion ring opposite to the sealing framework.
[0007] Among them, the outer edge of the both ends of the sealing sleeve ring is provided with an annular groove, and the expansion ring is clamped in the corresponding annular groove.
[0008] The longitudinal section of the expansion ring is trapezoidal, the longitudinal section of the annular groove is rectangular, and the width of the opening of the annular groove is smaller than the long side of the trapezoidal expansion ring.
[0009] The cross section of the sealing framework is annular, and the longitudinal section is concave-shaped, comprising an inner wall for pressing the expansion ring, an outer wall for covering the outer surface of the end of the plunger sleeve, and an annular end cover for connecting the inner wall and the outer wall.
[0010] The connection part of the inner wall and the outer wall of the sealing framework and the annular end cover is provided with an arc-shaped avoiding groove.
[0011] The technical scheme has the beneficial effects that the high-pressure fuel injection pump plunger pair in the utility model improves the sealing structure between the plunger sleeve and the plunger, ensures the sealing effect of up and down sliding, improves the separation of the fuel cavity and the cam cavity of the plunger sleeve in the fuel pump, ensures the output of high-pressure fuel, and reduces the loss of high-pressure fuel output. BRIEF DESCRIPTION OF DRAWINGS
[0012] Figure 1 It is a sectional view of the fuel injection pump plunger pair in the prior art.
[0013] Figure 2 It is a sectional view of the high-pressure fuel injection pump plunger pair of the preferred embodiment in the utility model. DETAILED DESCRIPTION
[0014] The utility model will be further described by way of examples, but the utility model is not limited in the scope of the examples.
[0015] In the description of the utility model, it is understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the utility model.
[0016] As Figure 2As shown, the high-pressure fuel injection pump plunger pair in the embodiment includes a plunger sleeve 100, a plunger hole 101' for passing through the plunger 200 is arranged in the middle of the plunger sleeve 100, the inner wall of the plunger hole 101' is provided with a receiving groove 102, a sealing sleeve ring 1 is arranged in the receiving groove 102, and the sealing sleeve ring 1 coincides with the central axis of the plunger hole 101'. The plunger 200 passes through the plunger hole 101' and the sealing sleeve ring 1 in sequence and extends out of the plunger hole 101'. The two ends of the sealing sleeve ring 1 are provided with expansion rings 12. The bottom of the plunger hole 101' is provided with a sealing skeleton 2. The sealing skeleton 2 is pressed on the end of the plunger sleeve 100 and the expansion ring 12 opposite to the sealing skeleton 2.
[0017] Specifically, the outer edge of the two ends of the sealing sleeve ring 1 is provided with an annular groove 11, and the expansion ring 12 is clamped in the annular groove 11. In the embodiment, the longitudinal section of the expansion ring 12 is a trapezoid, the longitudinal section of the annular groove 11 is a rectangle, and the width of the opening of the annular groove 11 is smaller than the long side of the trapezoidal expansion ring 12.
[0018] The cross section of the above-mentioned sealing skeleton 2 is annular, and the longitudinal section is a concave shape, including an inner wall 21 for pressing the expansion ring 12, an outer wall 22 for covering the outer surface of the end of the plunger sleeve 100, and an annular end cover 23 for connecting the inner wall 21 and the outer wall 22. The distance between the inner wall 21 and the outer wall 22 is matched with the thickness of the end of the plunger sleeve 100.
[0019] In addition, in order to ensure that the end of the plunger sleeve 100 does not collide with the sealing skeleton 2 when the plunger sleeve 100 is assembled with the sealing skeleton 2, and to improve the service life of the sealing skeleton 2, an arc-shaped avoiding groove 24 is arranged at the joint of the inner wall 21 and the outer wall 22 of the sealing skeleton 2 and the annular end cover 23.
[0020] During assembly, the short side of the expansion ring 12 is clamped towards the inside of the annular groove 11 until the long side of the trapezoid enters the inside of the annular groove 11, then the sealing sleeve ring 1 is embedded in the receiving groove 102, the plunger 200 is inserted into the sealing sleeve ring 1 and the plunger hole 101', and finally the sealing skeleton 2 is sleeved on the bottom of the plunger sleeve 100. Of course, in other embodiments, the longitudinal section of the annular groove 11 can also be a reverse trapezoid which is mirror-symmetrical with the longitudinal section of the expansion ring 12, so as to ensure that the expansion ring 12 expands the annular groove 11 to both sides after assembly, thereby abutting against the inner wall of the through hole 101 and the outer surface of the plunger 200, and achieving the sealing effect.
[0021] The high-pressure fuel injection pump plunger couple in the embodiment improves the sealing structure between the plunger sleeve and the plunger, ensures the sealing effect of up and down sliding, improves the separation of the fuel cavity of the plunger sleeve and the cam cavity in the fuel pump, ensures the output of high-pressure fuel, and reduces the loss of high-pressure fuel output.
[0022] Although the specific embodiments of the present application are described above, those skilled in the art should understand that this is only an example, the protection scope of the present application is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present application, but these changes and modifications all fall within the protection scope of the present application.
Claims
1. A high pressure fuel injection pump plunger pair characterized by: It includes a plunger sleeve, the middle part of the plunger sleeve is provided with upper and lower through plunger holes for penetrating the plunger, the inner wall of the plunger hole is provided with a containing groove, a sealing sleeve ring is arranged in the containing groove, the sealing sleeve ring coincides with the central axis of the plunger hole, the plunger penetrates the plunger hole and the sealing sleeve ring in sequence, the both ends of the sealing sleeve ring are provided with expansion rings, the bottom of the plunger hole is provided with a sealing skeleton, and the sealing skeleton is pressed on the end of the plunger sleeve and the expansion ring opposite to the sealing skeleton.
2. The high pressure fuel injection pump plunger couple of claim 1, wherein: The outer edge of the both ends of the sealing sleeve ring is provided with an annular groove, and the expansion ring is clamped in the corresponding annular groove.
3. The high pressure fuel injection pump plunger couple of claim 2, wherein: The longitudinal section of the expansion ring is a trapezoid, the longitudinal section of the annular groove is a rectangle, and the width of the opening of the annular groove is smaller than the long side of the trapezoidal expansion ring.
4. The high pressure fuel injection pump plunger couple of claim 3, wherein: The cross section of the sealing skeleton is annular, the longitudinal section is a concave shape, including an inner wall for pressing the expansion ring, an outer wall for covering the outer surface of the end of the plunger sleeve, and an annular end cover for connecting the inner wall and the outer wall, and the spacing between the inner wall and the outer wall of the sealing skeleton is matched with the end wall thickness of the plunger sleeve.
5. The high pressure fuel injection pump plunger couple of claim 4, wherein: The junction of the inner wall and the outer wall of the sealing skeleton and the annular end cover is provided with an arc-shaped avoiding groove.