Engine cylinder head oil injection hole once forming precision reamer

Abstract

The utility model provides a kind of engine cylinder head oil injection hole one-time forming precision reamer, including tool body, first cutting edge, second cutting edge, third cutting edge and fourth cutting edge are sequentially provided with in tool body from clamping end to cutting end;When tool body rotates, the rotation track of first cutting edge, second cutting edge, third cutting edge and fourth cutting edge is coaxially arranged;First cutting edge is used for first oil hole forming;Second cutting edge is used for second oil hole forming;Third cutting edge is used for third oil hole forming;Fourth cutting edge is used for fourth oil hole forming.By integrating four processing cutting edges in single tool body, and simultaneously completing the processing of all oil holes in one clamping, the coaxiality deviation of each section oil hole caused by factors such as tool repeated positioning error, spindle taper hole cleanliness influence, tool radial runout and machine tool thermal deformation in traditional process due to multiple tool changes is completely avoided.

Description

Technical Field

[0001] This utility model relates to the field of engine cylinder head manufacturing technology, specifically a precision reamer for one-time forming of oil injection holes in engine cylinder heads. Background Technology

[0002] The fuel injection holes on the engine cylinder head are a key component of the fuel injection system. Their structure typically consists of a first fuel hole, a second fuel hole, a third fuel hole, and a fourth fuel hole connected in sequence (see reference). Figure 3 The diameter of each oil hole decreases progressively to meet the requirements of fuel atomization and injection pressure.

[0003] Currently, the conventional machining process for these four-segment oil injection holes employs a "one-time clamping, four-tool change" method. Specifically, after the workpiece is clamped and positioned once, the first, second, third, and fourth oil holes are machined sequentially by changing tools of different diameters. Although a single clamping helps ensure the relative positional accuracy between the holes, in actual machining, due to the need for multiple tool changes, a slight deviation in the relative position of the tool and the workpiece is inevitable after each tool change. This deviation mainly stems from factors such as the repeatability of the tool holder, the cleanliness of the spindle taper hole, the radial runout of the tool itself, and the thermal deformation of the machine tool system.

[0004] The positional deviations that occur during the tool changing process directly lead to cumulative errors in the coaxiality of the various oil holes. When the coaxiality of the first, second, third, and fourth oil holes exceeds the design allowable range, a series of problems will occur: First, it will change the fuel flow trajectory, increase flow resistance, and affect the fuel atomization effect and injection accuracy; second, it may cause stress concentration at the oil hole connection, reducing the fatigue life of the cylinder head.

[0005] Therefore, there is an urgent need to develop a new oil injection hole machining process to eliminate the positional deviation caused by tool changes, thereby improving the coaxiality accuracy of multi-segment oil holes. Utility Model Content

[0006] To address the technical problems in the background art, this utility model discloses a precision reamer for one-time forming of the fuel injection hole in the engine cylinder head.

[0007] This utility model provides a precision reamer for one-time forming of oil injection holes in engine cylinder head, including a tool body for machining and forming oil injection holes on engine cylinder head. The oil injection hole is composed of a first oil hole, a second oil hole, a third oil hole and a fourth oil hole connected in sequence with decreasing diameter. The tool body is provided with a first cutting edge, a second cutting edge, a third cutting edge and a fourth cutting edge in sequence from the clamping end to the cutting end. When the blade rotates, the rotation trajectories of the first, second, third, and fourth cutting edges are arranged coaxially. The first cutting edge is used to form the first oil hole; The second cutting edge is used for forming the second oil hole; The third cutting edge is used for forming the third oil hole; The fourth cutting edge is used for forming the fourth oil hole.

[0008] Furthermore, the cutting part of the tool body is provided with an axially extending groove that penetrates the tool body radially; The portion of the blade body located between adjacent grooves constitutes the cutting blade; The first, second, third, and fourth cutting edges are located on the outer side of the cutter.

[0009] Furthermore, the blade body is provided with an axially extending infusion port; The cutting fluid is introduced through the inlet port; The outlet of the infusion port is located in the cutting part of the blade.

[0010] Furthermore, the outlet is located on the wall of the groove.

[0011] Furthermore, the outlet is located at the root of the groove wall.

[0012] Furthermore, there are four exits, which are located on the same axial position as the first, second, third, and fourth cutting edges of the blade body.

[0013] Furthermore, there are three exits; The outlets at both ends are located on the same axial direction as the first and fourth cutting edges of the tool body, respectively; The middle exit section is located on the same axial position as the second cutting edge of the blade body, and the remaining section is located on the same axial position as the third cutting edge of the blade body.

[0014] Furthermore, the orientation of the outlet forms an acute or obtuse angle with the axis of the blade body; The outlet faces the cutting end of the tool body.

[0015] The beneficial effects of this utility model are: 1. By integrating four machining edges into a single tool body and simultaneously machining all oil holes in a single setup, this process completely avoids the coaxiality deviations of oil holes caused by factors such as repeated tool positioning errors, spindle taper hole cleanliness issues, tool radial runout, and machine tool thermal deformation resulting from multiple tool changes in traditional processes. The rotational trajectories of each cutting edge are coaxially arranged, ensuring extremely high coaxiality accuracy for the first, second, third, and fourth oil holes from a technological perspective. This guarantees a stable and smooth fuel flow trajectory through each oil hole, effectively reducing flow resistance and improving fuel atomization and injection accuracy, thereby enhancing engine combustion efficiency and emissions performance. Furthermore, it avoids stress concentration at oil hole connections caused by coaxiality deviations, significantly improving the fatigue strength and long-term reliability of the engine cylinder head and extending component life.

[0016] 2. The traditional "one-time clamping, four-time tool changing" is simplified to "one-time clamping, one-time forming", which greatly reduces the auxiliary time of the machine tool (such as tool changing and tool setting time) and improves production efficiency. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Figure 1 This is the front view of this utility model; Figure 2 This is a bottom view of the present invention; Figure 3 This is a front sectional view of the part of the engine cylinder head where the fuel injection holes are located; In the diagram: 1. Blade body; 2. Groove; 3. Cutting blade; 4. Infusion port; 5. Cylinder cover; 11. First cutting edge; 12. Second cutting edge; 13. Third cutting edge; 14. Fourth cutting edge; 31. First oil hole; 32. Second oil hole; 33. Third oil hole; 34. Fourth oil hole; 41. Outlet. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the present invention, and therefore only show the components relevant to the present invention.

[0020] like Figure 1 As shown, this utility model discloses a precision reamer for one-time forming of fuel injection holes in engine cylinder heads, including a cylindrical cutter body 1, used for machining and forming fuel injection holes on engine cylinder heads 5, as shown. Figure 3 As shown, the oil injection hole is composed of a first oil hole 31, a second oil hole 32, a third oil hole 33 and a fourth oil hole 34 connected in sequence with decreasing diameter.

[0021] The cutting portion of the cutter body 1 has four grooves 2 evenly distributed circumferentially around the cutter body 1. The two walls of each groove 2 are perpendicular to each other, thus forming a cutter 3 of uniform thickness between adjacent grooves 2. The structure of the grooves 2 has the following advantages: 1. It forms four completely symmetrical cutters 3. This symmetrical structure ensures excellent dynamic balance performance of the cutter body 1 during high-speed rotation, effectively suppressing vibration during the cutting process. 2. Each cutter 3 has a regular geometry and uniform cross-section. This structure provides the necessary chip space, and the uniform thickness distribution allows cutting force and heat to be evenly transferred and dispersed throughout the cutter body 1, preventing local stress concentration, thereby reducing tool wear and deformation, and extending tool life.

[0022] From the clamping end of the cutter body 1 to the cutting end, the outer surface of the cutter 3 is sequentially provided with a first cutting edge 11, a second cutting edge 12, a third cutting edge 13, and a fourth cutting edge 14. When the cutter body 1 rotates, the rotation trajectories of the first cutting edge 11, the second cutting edge 12, the third cutting edge 13, and the fourth cutting edge 14 are arranged coaxially, and the diameter of the trajectory decreases progressively. The rotation trajectories of the first cutting edge 11, the second cutting edge 12, the third cutting edge 13, and the fourth cutting edge 14 are modeled after the oil injection holes. The first cutting edge 11 is used for forming the first oil hole 31; the second cutting edge 12 is used for forming the second oil hole 32; the third cutting edge 13 is used for forming the third oil hole 33; and the fourth cutting edge 14 is used for forming the fourth cutting edge 14.

[0023] Because the cutting process of the tool body 1 generates a large amount of heat, an axially extending fluid inlet 4 is provided inside the tool body 1. The cutting fluid is input from the inlet of the fluid inlet 4; the outlet 41 of the fluid inlet 4 is located at the root of the groove wall of the groove 2 in the cutting part of the tool body 1. Compared with the traditional use of an external spray pipe, the advantages of this setting are: 1. The cutting fluid is directly delivered to the vicinity of the first to fourth cutting edges 14 that are performing the cutting task through the fluid inlet 4 inside the tool body 1. This "internal direct" delivery method ensures that the cutting fluid can act accurately and efficiently on the cutting point, thereby achieving sufficient cooling of the cutting edge and effectively avoiding tool annealing, hardness reduction and excessive wear caused by the accumulation of cutting heat; at the same time, the excellent lubrication effect reduces cutting resistance. The combined effect of these two factors significantly improves the service life of the precision reamer and ensures the surface finish of the inner walls of each section of the oil hole.

[0024] In a traditional design, there are four outlets 41, located on the same axial direction as the first cutting edge 11, the second cutting edge 12, the third cutting edge 13, and the fourth cutting edge 14 on the blade body 1. Too many outlets 41 would reduce the strength of the cutter 3 and affect the service life of the precision reamer. Therefore, in this embodiment, there are three outlets 41; the outlets 41 at both ends are located on the same axial direction as the first cutting edge 11 and the fourth cutting edge 14 on the blade body 1, respectively; the middle outlet 41 is partially located on the same axial direction as the second cutting edge 12 on the blade body 1, and the remaining portion is located on the same axial direction as the third cutting edge 13 on the blade body 1.

[0025] like Figure 2 As shown, the outlet 41 is oriented at an acute or obtuse angle to the axis of the tool body 1; the outlet 41 faces the cutting end of the tool body 1. With this configuration, the cutting fluid no longer flows parallel to the tool axis or randomly, but is precisely guided in front of the cutting edge where cutting will occur. This allows for sufficient cooling and lubrication of the machining area before the cutting edge contacts the workpiece material, effectively reducing the temperature of the cutting area, minimizing tool wear, and creating favorable conditions for subsequent cutting.

[0026] Compared with existing technologies, the beneficial effects of this embodiment are as follows: 1. By integrating four machining edges into a single tool body 1 and simultaneously completing the machining of all oil holes in one clamping, the coaxiality deviation of each section of oil holes caused by factors such as repeated tool positioning errors, spindle taper hole cleanliness effects, tool radial runout, and machine tool thermal deformation caused by multiple tool changes in traditional processes is completely avoided. The rotation trajectories of each cutting edge are arranged coaxially, ensuring that the first, second, third, and fourth oil holes 34 have extremely high coaxiality accuracy from a process principle perspective. This ensures that the fuel flows smoothly and stably through each section of oil holes, effectively reducing flow resistance, thereby improving the fuel atomization effect and injection accuracy, and enhancing the combustion efficiency and emission performance of the engine. It also avoids stress concentration at the oil hole connection due to excessive coaxiality, significantly improving the fatigue strength and long-term reliability of the engine cylinder head 5, and extending the service life of the components. 2. The traditional "one-time clamping, four-time tool changing" is simplified to "one-time clamping, one-time forming", which greatly reduces the auxiliary time of the machine tool (such as tool changing and tool setting time) and improves production efficiency.

[0027] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A precision reamer for one-time forming of fuel injection holes in engine cylinder head, comprising a cutter body (1) for machining fuel injection holes on engine cylinder head (5), wherein the fuel injection holes are composed of a first oil hole (31), a second oil hole (32), a third oil hole (33), and a fourth oil hole (34) connected in sequence with decreasing diameters, characterized in that: The blade body (1) is provided with a first cutting edge (11), a second cutting edge (12), a third cutting edge (13) and a fourth cutting edge (14) in sequence from the clamping end to the cutting end. When the blade (1) rotates, the rotation trajectories of the first cutting edge (11), the second cutting edge (12), the third cutting edge (13) and the fourth cutting edge (14) are arranged coaxially. The first cutting edge (11) is used to form the first oil hole (31); The second cutting edge (12) is used to form the second oil hole (32); The third cutting edge (13) is used for forming the third oil hole (33); The fourth cutting edge (14) is used to form the fourth oil hole (34).

2. The precision reamer for one-time forming of the fuel injection hole in the engine cylinder head according to claim 1, characterized in that: The cutting part of the blade (1) is provided with an axially extending groove (2) that penetrates the blade (1) radially. The portion of the blade body (1) located between adjacent grooves (2) constitutes the cutter (3); The first cutting edge (11), the second cutting edge (12), the third cutting edge (13) and the fourth cutting edge (14) are disposed on the outer side of the cutter (3).

3. The precision reamer for one-time forming of the fuel injection hole in the engine cylinder head according to claim 2, characterized in that: The blade body (1) is provided with an axially extending infusion hole (4). The cutting fluid is introduced from the inlet of the fluid inlet (4); The outlet (41) of the infusion hole (4) is located in the cutting part of the blade body (1).

4. The precision reamer for one-time forming of the fuel injection hole in the engine cylinder head according to claim 3, characterized in that: The outlet (41) is located on the groove wall of the groove (2).

5. The precision reamer for one-time forming of the fuel injection hole in the engine cylinder head according to claim 4, characterized in that: The outlet (41) is located at the root of the groove wall (2).

6. The precision reamer for one-time forming of the fuel injection hole in the engine cylinder head according to claim 5, characterized in that: The outlet (41) is set to four, which are located on the same axial position of the blade body (1) as the first cutting edge (11), the second cutting edge (12), the third cutting edge (13) and the fourth cutting edge (14).

7. The precision reamer for one-time forming of the fuel injection hole in the engine cylinder head according to claim 6, characterized in that: The outlet (41) is set to three; The outlets (41) at both ends are located on the same axial position of the blade body (1) as the first cutting edge (11) and the fourth cutting edge (14); The middle outlet (41) portion is located in the same axial position as the second cutting edge (12) on the blade body (1), and the remaining portion is located in the same axial position as the third cutting edge (13) on the blade body (1).

8. The precision reamer for one-time forming of the fuel injection hole in the engine cylinder head according to claim 3, characterized in that: The orientation of the outlet (41) forms an acute or obtuse angle with the axis of the blade body (1); The outlet (41) faces the cutting end of the tool body (1).

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