Machining tool and method suitable for large-diameter main bearing hole of diesel engine base

Abstract

The invention discloses a machining tool and method suitable for a large-diameter main bearing hole of a diesel engine base, solves the problems that in the prior art, the number of machining tool bits is large, errors are prone to being caused during installation, and hole walls are prone to being scratched, and has the beneficial effects that the machining efficiency and the machining quality are improved. According to the specific scheme, the machining tool suitable for the large-diameter main bearing hole of the diesel engine base comprises a rough boring tool and a fine boring tool, the rough boring tool comprises a first tool handle, the first tool handle is connected with a first tool rest, the first tool rest is cross-shaped, and a first turning tool is arranged at each end of the first tool rest; the length of each first turning tool exceeding the first tool rest is gradually increased; the fine boring cutter comprises a second cutter handle, the second cutter handle is connected with a second cutter frame, the second cutter frame is a double-turning-tool cutter frame, cutter clamping block bodies are arranged on the two sides of the second cutter frame respectively, the cutter clamping block bodies can be folded relative to the second cutter frame, and the cutter clamping block bodies on the two sides of the second cutter frame are detachably connected with a second turning tool and a third turning tool respectively.

Description

Technical Field

[0001] The invention relates to the technical field of diesel engine base machining, in particular to a tool and method for machining a large-diameter main bearing hole of a diesel engine base. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] The main bearing holes in the engine base of large diesel engines are critical dimensions and have high machining requirements. For example, the maximum main bearing diameters for the X82DF and 9x92DF (Dual-Fue) engines are Φ1100 (+0.105 / 0) mm, Φ1168 (+0.105 / 0) mm, and Φ1108 (+0.105 / 0) mm, respectively. The main bearing hole diameter must be at least Φ1100 mm, with a roughness of Ra1.6. The main shaft hole straightness must be 0.01 mm, and any adjacent holes must have a coaxiality of 0.03 mm. These requirements place strict demands on form and position tolerances and roughness.

[0004] Due to the large diameter of the machine body, the thickness of each gear also becomes thicker accordingly. For example, the thickness of the main bearing seat of the 9x92DF machine base is 404mm, and the tools used for processing also become longer accordingly. The processing accuracy and roughness of the large-diameter main bearing hole become processing difficulties.

[0005] When rough machining the large-diameter main bearing hole of a diesel engine base, the allowance is uneven and the machining vibration is large. Conventional boring tool machining requires two cuts, and the machining efficiency is relatively low.

[0006] In order to improve processing efficiency, some tools are equipped with multiple processing heads. Although the processing efficiency is improved during the processing, the clamping is more complicated due to the large number of heads. Once one or more of the heads are not installed properly, the accuracy and roughness of the main bearing hole will be affected. Moreover, when using a tool with multiple heads to finish the main bearing hole, the head is likely to scratch the hole wall of the main bearing hole when retracting the tool.

[0007] Second, for large main bearing holes, the quality of the rough boring tool is also relatively large, and it needs to be installed on site and removed after installation. If the quality of the rough boring tool is too large, it will be inconvenient to install and easy to remove.

[0008] In addition, the processing of large-diameter main bearing holes requires high tool stability and high strength of the tool body itself. In addition, the determination of machining allowance is also required. Especially during finishing, the reserved machining allowance and tool blade selection will affect the machining effect. Summary of the Invention

[0009] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a machining tool suitable for large-diameter main bearing holes of diesel engine bases, so as to solve the machining problem that the large-diameter main bearing holes of diesel engine bases are affected by the diameter and the thickness of the intermediate body, and the machining accuracy and roughness are difficult to ensure.

[0010] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0011] A machining tool suitable for machining a large-diameter main bearing hole in a diesel engine base, comprising a rough boring tool and a fine boring tool. The rough boring tool comprises a first tool holder connected to a first tool rest. The first tool rest is cross-shaped. A first turning tool is provided at each end of the first tool rest. In a clockwise direction, the length of each first turning tool extending beyond the first tool rest gradually increases.

[0012] The precision boring tool includes a second tool holder, which is connected to the second tool holder. The second tool holder is a double turning tool holder. Tool clamp blocks are respectively arranged on both sides of the second tool holder. The tool clamp blocks are foldable relative to the second tool holder. The tool clamp blocks on both sides of the second tool holder are respectively detachably connected to the second turning tool and the third turning tool.

[0013] As described above, a machining tool suitable for a large-diameter main bearing hole of a diesel engine base is provided with a first open groove at each end of the first tool holder, and a first opening is provided on the side of the first open groove of the first tool holder. After the first turning tool is provided in the first open groove, the first fastener passes through the first opening and abuts against the first turning tool. The first blade of the first turning tool is provided beyond the first open groove, and the first open groove of the first tool holder is located on the side of the first tool holder away from the first tool handle.

[0014] As described above, a tool suitable for machining large-diameter main bearing holes in a diesel engine base, wherein the first tool holder includes a center section, the center section is connected to the first tool handle, the center section is provided with four extending sections to form a cross shape, each extending section is provided with multiple weight-reducing holes, and adjacent extending sections are connected by a counterweight rod.

[0015] As described above, the tool for machining large-diameter main bearing holes in a diesel engine base is suitable, wherein the second turning tool and the third turning tool are both arc blades, and the radius of the third turning tool tip is greater than that of the second turning tool tip.

[0016] As described above, a machining tool suitable for large-diameter main bearing holes of a diesel engine base, the second tool holder is in a straight line shape, and second open grooves are respectively provided at both ends of the second tool holder. The tool holder block is installed in the second open groove, and the width of the tool holder block is adapted to the width of the second open groove. The tool holder block is detachably connected to the second turning tool or the third turning tool.

[0017] As described above, a machining tool suitable for a large-diameter main bearing hole of a diesel engine base is provided with a protrusion block in the second open groove, one end of the tool holder block is hingedly connected to one side of the connecting ear, and the other side of the connecting ear is hingedly connected to the protrusion block, so that the tool holder block can extend from the end of the second open groove.

[0018] As described above, a machining tool suitable for a large-diameter main bearing hole of a diesel engine base is provided, wherein the tool holder block is provided with a mounting groove, and a second opening is provided on the side of the tool holder block. After the second turning tool or the third turning tool is installed in the mounting groove, the second fastener passes through the second opening and abuts against the second turning tool or the third turning tool.

[0019] In a second aspect, the present invention further discloses a method for machining a large-diameter main bearing hole of a diesel engine base, using the machining tool for the large-diameter main bearing hole of a diesel engine base.

[0020] The above-mentioned method for machining a large-diameter main bearing hole of a diesel engine base includes the following contents:

[0021] Place the rough boring tool into the main bearing hole, leaving a 2mm margin on one side of the main bearing hole, and perform rough boring on the main bearing hole using the rough boring tool;

[0022] One side of the second tool holder of the fine boring tool is connected to the second turning tool, and the tool holder block on the other side is folded and the third turning tool is not installed;

[0023] After the rough boring process is completed, the second tool holder is connected to the processing spindle, and the fine boring tool is placed in the main bearing hole. A 0.15mm margin is left on one side of the main bearing hole. The main bearing hole is semi-finished by the second turning tool. After the processing is completed, the processing spindle drives the second tool holder to retract the tool.

[0024] After the semi-finishing is completed, the second turning tool is removed and the tool holder block connected to the second turning tool is retracted. The third turning tool is installed on one side of the second tool holder. The main bearing hole is finish-machined by the third turning tool. After the machining is completed, the machining spindle drives the second tool holder to retract.

[0025] In the above-mentioned method for processing a large-diameter main bearing hole of a diesel engine base, the second turning tool selects a blade with a tip of R0.2, and the third turning tool selects a blade with a tip of R0.8.

[0026] The beneficial effects of the present invention are as follows:

[0027] 1) The machining tools in the present invention include a rough boring tool and a fine boring tool. The rough boring tool performs rough machining on the main bearing hole, and the fine boring tool performs semi-finishing and fine machining on the main bearing hole. The rough boring tool is cross-shaped. Thus, four first turning tools are provided, which facilitates rapid and accurate installation. The length of the four first turning tools exceeding the first tool holder gradually increases, so that rough machining can be completed in one cut, effectively shortening the machining time and improving the efficiency of rough machining of the main bearing hole. The number of first turning tools is controlled, so that the first turning tools can be quickly installed in place to avoid affecting the accuracy and roughness of the main bearing hole.

[0028] The fine boring tool is a double-tool holder, so there will not be too many turning tools. The tool holder block of the second tool holder is foldable. When the second turning tool or the third turning tool is installed, the tool holder block is extended. When the second turning tool or the third turning tool is not needed, the corresponding tool holder block can be retracted to shorten the overall length and avoid the second turning tool or the third turning tool or the other side of the second tool holder scratching the wall of the main bearing hole when the tool is retracted.

[0029] 2) In the present invention, the first tool holder is provided with the first turning tool, and the structure of the first tool holder is reasonably arranged. The first tool holder includes 4 protruding sections to control the mass of the first tool holder, and weight-reducing holes are provided to further control the mass of the first tool holder, so as to facilitate the installation and disassembly of the rough boring tool.

[0030] 3) The second turning tool and the third turning tool in the present invention are both arc blades, which can significantly reduce the residual ridge height during the processing, thereby improving the surface quality and shortening the processing time, solving the problem that the processing accuracy and roughness of the main bearing hole of the large-diameter machine base are affected by the diameter and the thickness of the intermediate body, and are beneficial to improving the processing quality of the main bearing hole.

[0031] 4) In the present invention, second open grooves are respectively provided at both ends of the second tool holder, a protruding block is provided in the second open groove, and a convex block is provided on the tool holder block. The convex block and the protruding block are hingedly connected by a connecting ear. This makes it convenient to hide the tool holder block in the second open groove to avoid scratching the main bearing hole wall when retracting the tool, and also makes it convenient to pull the tool holder block out of the second open groove to connect with the second turning tool or the third turning tool.

[0032] 5) The processing method provided in the present invention can realize the processing of the main bearing hole of the engine base of a large diesel engine, first performing rough processing, then semi-finishing and finishing, leaving appropriate margins in rough processing and semi-finishing respectively, to avoid the problem of large processing vibration caused by uneven margins, and in semi-finishing and finishing, the tool holder block can be folded relative to the second tool holder to make space for the second turning tool and the third turning tool when retracting the tool, to avoid the extended tool holder block, the second turning tool or the third turning tool scratching the hole wall of the main bearing hole, and the method has been verified through practice to improve the processing quality of the main bearing hole of the engine base and effectively shorten the processing time. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0034] Figure 1 This is a schematic diagram of the main bearing hole of the diesel engine base.

[0035] Figure 2 The present invention is a schematic diagram of a rough boring tool suitable for machining a large-diameter main bearing hole of a diesel engine base according to one or more embodiments of the present invention.

[0036] Figure 3 The present invention is a schematic diagram of a precision boring tool suitable for machining a large-diameter main bearing hole of a diesel engine base according to one or more embodiments of the present invention.

[0037] In the figure: the distances or sizes between parts are exaggerated to show the positions of various parts, and the schematic diagram is for reference only.

[0038] Among them: 1. main bearing hole, 2 diesel engine base, 3. first tool holder, 4. first tool handle, 5. first turning tool, 6. counterweight rod, 7. first opening, 8. extension section, 9. first open groove, 10. second tool handle, 11. second turning tool, 12. tool holder block, 13. connecting ear, 14. protrusion, 15. second tool holder. DETAILED DESCRIPTION

[0039] It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0040] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless otherwise clearly indicated in the present invention, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "include" and / or "comprising" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or their combinations;

[0041] As introduced in the background technology, the processing tools for the main bearing holes of the diesel engine base in the prior art cannot guarantee the processing accuracy and roughness of the main bearing holes, and the processing tools are prone to damage the wall of the main bearing holes when retracting the tool. In order to solve the above technical problems, the present invention proposes a processing tool suitable for the large-diameter main bearing holes of the diesel engine base.

[0042] Example 1

[0043] In a typical embodiment of the present invention, referring to Figure 1 、 Figure 2 and Figure 3 As shown, a machining tool suitable for a large-diameter main bearing hole in a diesel engine base includes a rough boring tool and a fine boring tool. The rough boring tool includes a first tool holder 4, which is connected to a first tool holder 3. The first tool holder 3 is cross-shaped, and a first open slot is provided at each end of the first tool holder 3. The first tool holder 3 is provided with a first opening 7 on the side of the first open slot 9. After a first turning tool 5 is provided in the first open slot 9, a first fastener passes through the first opening 7 and abuts against the first turning tool 5. The first cutting edge of the first turning tool 5 is provided beyond the first open slot 9. In the clockwise direction, the length of each first cutting edge beyond the corresponding first open slot 9 gradually increases.

[0044] The precision boring tool includes a second tool holder 10, which is connected to a second tool holder 15. The second tool holder 15 is a double-turning tool holder. Tool clamp blocks 12 are respectively arranged on both sides of the second tool holder 15. The tool clamp blocks 12 are foldable relative to the second tool holder 15. The tool clamp blocks on both sides of the second tool holder 15 are respectively detachably connected to the second turning tool 11 and the third turning tool. The foldable tool clamp block 12 can be pulled out from the second tool holder 15 when the tool clamp block 12 needs to be connected to the second turning tool 11 or the third turning tool to install the second turning tool 11 and the third turning tool. When the second turning tool 11 or the third turning tool is retracted, the tool clamp block 12 is folded relative to the second tool holder 15 to avoid the extended tool clamp block from touching the wall of the main bearing hole 1 when the tool is retracted, so as to avoid scratching the wall of the hole.

[0045] refer to Figure 2 As shown, the first tool holder 3 includes a central section, which is connected to the first tool handle 4. The central section is provided with four protruding sections 8 to form a cross shape. The adjacent protruding sections 8 are connected by an arc transition. The length of each protruding section 8 is the same. Each protruding section 8 is provided with a plurality of weight-reducing holes to control the weight of the first tool holder. The adjacent protruding sections 8 are connected by a counterweight rod 6. The counterweight rod 6 and the protruding sections 8 on both sides form a structure approximately in the shape of a right triangle. The first open groove of the first tool holder 3 is located on the side of the first tool holder 3 away from the first tool handle 4.

[0046] In some examples, the length of the first tool handle 4 is an extended tool handle, the first tool handle 4 is a cylindrical structure, the thicker end of the first tool handle 4 is connected to the central section of the first tool holder 3, and the other end of the first tool handle is frustum-shaped to be engaged with the machining spindle.

[0047] Among them, the length of the first open groove 9 is greater than that of the first turning tool 5. The first turning tool 5 uses an existing turning tool. The tool head part of the first turning tool 5 is provided with a stage to limit the tool head part of the first turning head through the end of the first extending section.

[0048] In this embodiment, each extending section 8 is provided with a first opening 7 at the portion extending beyond the counterweight rod 6. A plurality of first openings 7 are provided along the length direction of the first open groove 9, and a distance is set between two adjacent first openings 7. The first fastener can be a first bolt, and the first opening 7 is a first bolt hole. The first bolt passes through the first opening 7 and abuts against the first turning tool 5 to fix the first turning tool.

[0049] It should be noted that the second turning tool 11 and the third turning tool are both arc blades, the radius of the third turning tool tip is larger than the radius of the second turning tool tip, the second turning tool selects a blade with a tip of R0.2, and the third turning tool specifically selects a blade with a tip of R0.8.

[0050] refer to Figure 3 As shown, the second tool holder 15 is in a straight line shape, and the second tool handle 10 is connected to the center of the second tool holder 15. The structure of the second tool handle 10 is the same as that of the first tool handle 4. Second open grooves are respectively provided at both ends of the second tool handle 10. The second open groove is located on the side of the second tool holder 15 away from the second tool handle 10. A tool holder block 12 is installed in the second open groove, and the tool holder block 12 is detachably connected to the second turning tool 11 or the third turning tool.

[0051] It should be noted that a protruding block is provided in the second open groove, and the protruding block can be a long strip. A protrusion 14 is also provided on one side of the tool holder block 12. The protrusion 14 of the tool holder block is hingedly connected to one side of the connecting ear 13. The connecting ear 13 is provided on both sides of the protruding block. The distance between the connecting ears on both sides is smaller than the width of the second open groove. The other side of the connecting ear 13 is hingedly connected to the protruding block. By pulling the tool holder block 12 relative to the second tool holder 15, the tool holder block 12 can be extended from the end of the second open groove. Pushing the tool holder block 12 inward can retract the tool holder block relative to the second open groove.

[0052] In addition, the width of the tool holder block 12 is adapted to the width of the second open groove, so that the tool holder block can be inserted into the second open groove, and the tool holder block 12 can be driven to move under the action of external force. A mounting groove is provided on the side of the tool holder block 12 away from the protrusion, and a second opening is provided on the side of the tool holder block. After the second turning tool or the third turning tool is installed in the mounting groove, the second fastener passes through the second opening and abuts against the second turning tool 11 or the third turning tool, thereby achieving the fixation of the second turning tool or the third turning tool, and also facilitating the removal of the second turning tool and the third turning tool. The second fastener can be a second bolt, and the second opening can be a second bolt hole.

[0053] The processing tool provided in this embodiment adopts a cross-shaped four-turning tool symmetrical rough boring tool, which evenly distributes the rough processing allowance on the four tool positions by time-sharing and component cutting, and completes the rough processing of the boring hole with one cut, solving the problem of vibration caused by uneven allowance during rough processing of large-diameter main bearing holes; the second turning tool is used for semi-finishing, and the third turning tool is used for finishing. The first and second tool holders are reasonably structured, effectively controlling the quality of the first and second tool holders, facilitating and quick replacement, and the overall cooperation can quickly process the main bearing hole. The second and third turning tools both use R-arc blades, solving the processing problem that the main bearing hole of the large-diameter machine base is difficult to ensure the processing accuracy and roughness due to the influence of the diameter and the thickness of the intermediate body.

[0054] Example 2

[0055] This embodiment provides a method for machining a large-diameter main bearing hole in a diesel engine base, using a machining tool for machining a large-diameter main bearing hole in a diesel engine base described in Example 1, and specifically includes the following steps:

[0056] Place the rough boring tool into the main bearing hole 1, leaving a 2mm margin on one side of the main bearing hole, and perform rough boring on the main bearing hole using the rough boring tool;

[0057] One side of the second tool holder 15 of the fine boring tool is connected to the second turning tool 11, and the tool holder block on the other side is folded and the third turning tool is not installed;

[0058] After the rough boring process is completed, the second tool holder 10 is connected to the machining spindle, and the fine boring tool is placed in the main bearing hole 1, leaving a 0.15mm margin on one side of the main bearing hole. The main bearing hole is semi-finished by the second turning tool. During the boring process, the hole mouth is trial-cut to confirm the boring tool size. After the processing is completed, the machining spindle drives the second tool holder 10 to retract the tool. During the retraction process, the tool holder block 12 on the other side of the second tool holder 15 is folded to avoid scratching the spindle hole wall.

[0059] After the semi-finishing is completed, the second turning tool 11 is removed and the tool holder block 12 connected to the second turning tool is retracted. The third turning tool is installed on one side of the second tool holder 15. The main bearing hole is finish-machined by the third turning tool. When boring, the hole mouth is trial-cut to confirm the size of the boring tool. After the processing is completed, the processing spindle drives the second tool holder to retract.

[0060] Specifically, the second turning tool 11 selects a blade with a cutting edge of R0.2, and the third turning tool selects a blade with a cutting edge of R0.8.

[0061] The above processing method can realize the processing of the main bearing hole of the engine base 2 of a large diesel engine. Rough processing is carried out first, and then semi-finishing and finishing are carried out. Appropriate allowances are left in rough processing and semi-finishing respectively to avoid the problem of large processing vibration caused by uneven allowances and ensure the processing quality. In semi-finishing and finishing, the tool holder block can be folded relative to the second tool holder to make room for the second turning tool and the third turning tool when retracting the tool to avoid the extended tool holder block, the second turning tool or the third turning tool scratching the hole wall of the main bearing hole. The method has been verified in practice to improve the processing quality of the main bearing hole of the engine base, effectively shorten the processing time, and improve the processing efficiency of a single engine base.

[0062] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A tool for machining large diameter main bearing holes in a diesel engine base, characterized in that: The tool comprises a rough boring tool and a fine boring tool. The rough boring tool comprises a first tool handle connected to a first tool holder. The first tool holder is cross-shaped. A first turning tool is provided at each end of the first tool holder. In a clockwise direction, the length of each first turning tool extending beyond the first tool holder gradually increases. The precision boring tool includes a second tool holder, which is connected to the second tool holder. The second tool holder is a double turning tool holder. Tool clamp blocks are respectively arranged on both sides of the second tool holder. The tool clamp blocks are foldable relative to the second tool holder. The tool clamp blocks on both sides of the second tool holder are respectively detachably connected to the second turning tool and the third turning tool.

2. A machining tool for a large-diameter main bearing hole of a diesel engine base according to claim 1, characterized in that: A first open groove is provided at each end of the first tool holder, and a first opening is provided on the side of the first open groove. After the first turning tool is provided in the first open groove, the first fastener passes through the first opening and abuts against the first turning tool. The first blade of the first turning tool is provided beyond the first open groove. The first open groove of the first tool holder is located on the side of the first tool holder away from the first tool handle.

3. A machining tool for a large-diameter main bearing hole of a diesel engine base according to claim 1, characterized in that: The first tool holder includes a central section, which is connected to the first tool handle. The central section is provided with four extending sections to form a cross shape. Each extending section is provided with multiple weight-reducing holes, and adjacent extending sections are connected by a counterweight rod.

4. A tool for machining large-diameter main bearing holes of a diesel engine base according to claim 1, characterized in that: The second turning tool and the third turning tool are both arc blades, and the radius of the third turning tool tip is greater than the radius of the second turning tool tip.

5. The tool for machining large-diameter main bearing holes of a diesel engine base according to claim 1, characterized in that: The second tool holder is in a straight line shape, and second open grooves are respectively provided at both ends of the second tool holder. The tool holder block is installed in the second open groove. The width of the tool holder block is adapted to the width of the second open groove. The tool holder block is detachably connected to the second turning tool or the third turning tool.

6. A tool for machining large-diameter main bearing holes in a diesel engine base according to claim 5, characterized in that: A protruding block is provided in the second open slot, one end of the tool holder block is hingedly connected to one side of the connecting ear, and the other side of the connecting ear is hingedly connected to the protruding block, so that the tool holder block can extend from the end of the second open slot.

7. The tool for machining large-diameter main bearing holes of a diesel engine base according to claim 5, characterized in that: The tool holder block is provided with a mounting groove, and the side of the tool holder block is provided with a second opening. After the second turning tool or the third turning tool is installed in the mounting groove, the second fastener passes through the second opening and abuts against the second turning tool or the third turning tool.

8. A method for machining large diameter main bearing holes in a diesel engine base, characterized in that: A machining tool suitable for a large-diameter main bearing hole of a diesel engine base is used as claimed in any one of claims 1 to 7.

9. A method for machining a large-diameter main bearing hole of a diesel engine base according to claim 8, characterized in that: Includes the following: Place the rough boring tool into the main bearing hole, leaving a 2mm margin on one side of the main bearing hole, and perform rough boring on the main bearing hole using the rough boring tool; One side of the second tool holder of the fine boring tool is connected to the second turning tool, and the tool holder block on the other side is folded and the third turning tool is not installed; After the rough boring process is completed, the second tool holder is connected to the processing spindle, and the fine boring tool is placed in the main bearing hole. A 0.15mm margin is left on one side of the main bearing hole. The main bearing hole is semi-finished by the second turning tool. After the processing is completed, the processing spindle drives the second tool holder to retract the tool. After the semi-finishing is completed, the second turning tool is removed and the tool holder block connected to the second turning tool is retracted. The third turning tool is installed on one side of the second tool holder. The main bearing hole is finish-machined by the third turning tool. After the machining is completed, the machining spindle drives the second tool holder to retract.

10. A method for machining a large-diameter main bearing hole of a diesel engine base according to claim 9, characterized in that: The second turning tool is selected to have a blade with a tip of R0.2, and the third turning tool is selected to have a blade with a tip of R0.8.

Images