A marine engine cylinder body sealing groove processing device and method, and a marine engine

Abstract

The application provides a marine engine cylinder body sealing groove processing device and method and a marine engine, relates to the field of marine engine manufacturing, and aims to solve the problem that existing boring devices are inconvenient to process non-standard size sealing grooves. The application forms a slidable and rotatable cooperation structure between the fixed seat and the cutter bar, and is supplemented with a locking part, so that the cutter bar can not only slide along the sliding hole to flexibly adjust the rotary processing radius of the boring cutter, realize step-by-step cutting of a wider non-standard groove body with a narrower standard boring cutter, but also rotate along the sliding hole to adaptively adjust the cutting rake angle of the boring cutter. In the process of full-edge cutting of the base groove body by the first-step boring cutter, the rake angle is moderately reduced to enhance the impact resistance of the cutting edge and maintain the stability of boring, and the rake angle is increased in the process of local-edge light cutting of the expanded groove by the second-step boring cutter to reduce the cutting resistance and improve the feeding efficiency. The universality of the standard cutter is improved, the processing stability and operation efficiency in the process of step-by-step cutting are balanced, and the forming quality of the large-diameter sealing groove is improved.

Description

Technical Field

[0001] This invention relates to the field of marine engine manufacturing, specifically to a marine engine cylinder block sealing groove processing device, method, and marine engine. Background Technology

[0002] The segmented cylinder block assembly connection surface of large marine engines requires the machining of large-diameter annular sealing grooves. Milling with a small-diameter end mill results in low machining efficiency, high tool wear, and extremely long machining time.

[0003] Chinese patent (publication number: CN115070367A) discloses a scheme for using a boring bar combined with a rotary tool to make large-diameter sealing grooves. However, the width of the boring bar's cutting edge must be exactly equal to the width of the cylinder block sealing groove. When dealing with non-standard sealing grooves such as 4.5mm wide ones, it is still necessary to customize boring bars with non-standard widths. Although multiple boring bar clamping positions are set, they are for machining sealing grooves of different specifications, rather than switching clamping positions to achieve machining of the same non-standard width sealing groove. Even with multiple radial clamping positions, under a rigid fixed clamping structure, multi-step boring with fixed parameters is not only inefficient, but also leads to easy chipping of the cutting edge during the heavy cutting stage, poor cutting during the light cutting stage, and poor surface quality of the groove wall, making it difficult to meet the high-efficiency boring requirements of non-standard sealing grooves. Summary of the Invention

[0004] In view of this, the present invention provides a machining apparatus, method and marine engine for machining cylinder block sealing grooves, which improves the versatility of standard cutting tools and reduces the cost of tool customization and use, while also balancing machining stability and overall work efficiency in the step-by-step cutting process.

[0005] The first objective of this invention is to provide a machining device for sealing grooves in marine engine cylinder blocks, employing the following solution: include: The tool holder is capable of rotating and is equipped with a rotation drive unit and a fixed unit. The rotation drive unit extends radially along the rotation axis and then connects to the fixed unit. A fixed base is installed on the fixed part and has a sliding hole; The tool holder is detachably mounted with a boring bar. The tool holder and the sliding hole form a sliding fit and are fitted with a locking element. The tool holder slides axially relative to the sliding hole to adjust the turning radius of the boring bar, and / or the tool holder rotates axially relative to the sliding hole to adjust the rake angle of the boring bar's machining position.

[0006] Furthermore, the rotary drive unit is also connected to a counterweight unit, which and the fixing unit are located on opposite sides of the rotary axis, and a counterweight block is installed on the counterweight unit.

[0007] Furthermore, the fixed base is provided with a plurality of locking holes that are connected to the sliding holes. The locking holes are spaced apart along the axial direction of the sliding holes, and at least two locking holes are staggered along the circumferential direction. The outer circumference of the tool bar is provided with locking grooves distributed along the generatrix direction. After the locking member is engaged with the locking hole, it is inserted into the locking groove to lock the axial and circumferential positions of the tool bar relative to the sliding hole.

[0008] Furthermore, the locking groove and the locking element inserted therein are in an interference fit.

[0009] Furthermore, multiple locking holes located in the same circumferential position simultaneously engage with locking components, protruding into the locking groove to constrain the position of the tool bar, while the locking components engaged with other locking holes retract into the locking holes.

[0010] Furthermore, the locking hole is a threaded hole, and the locking element is a locking pin with a threaded section. One end of the threaded section of the locking pin is connected to the optical shaft to form a locking end, and its diameter is smaller than that of the threaded section. The other end is connected to an operating part, which is configured to be rotated and adjusted under the action of external force.

[0011] Furthermore, it also includes a drive spindle, which is connected to a rotary drive unit and adjusts the speed according to the rotary machining radius and rake angle.

[0012] Furthermore, the drive spindle is equipped with a feed mechanism that reciprocates along the rotation axis of the tool holder.

[0013] A second objective of the present invention is to provide a method for machining a sealing groove in a marine engine cylinder block, utilizing the machining apparatus for machining a sealing groove in a marine engine cylinder block as described in the first objective, comprising: The tool holder slides and rotates relative to the sliding hole, the boring tool is adjusted to the first turning radius and the first rake angle, and locked by the locking device. Then, driven by the tool holder, it rotates at the first speed to bore out the basic groove. Unlock the tool holder, allowing it to slide and rotate relative to the sliding hole. Adjust the boring tool to the second turning radius and second rake angle, and then relock it. Subsequently, rotate it at the second rotation speed under the drive of the tool post to bore the side allowance of the base groove to achieve the desired target width. Among them, the second front angle is greater than the first front angle, and the second rotational speed is greater than the first rotational speed.

[0014] A third objective of the present invention is to provide a marine engine in which the sealing groove of the cylinder block is processed using the marine engine cylinder block sealing groove processing method described in the second objective.

[0015] Compared with the prior art, the advantages and positive effects of this invention are: To address the problem that existing boring devices are inconvenient for machining non-standard sized sealing grooves, this invention establishes a sliding and rotating mating structure between the fixed base and the tool holder, supplemented by a locking component. This allows the tool holder to not only slide along the sliding hole to flexibly adjust the boring tool's rotation radius, enabling the step-by-step cutting of wider non-standard grooves with a narrower standard boring tool, but also to rotate along the sliding hole to adaptively adjust the boring tool's rake angle. During step-by-step cutting, in the first step where the boring tool cuts the base groove with its full edge, the rake angle is appropriately reduced to enhance the cutting edge's impact resistance and maintain boring stability. In the second step, when the boring tool lightly cuts the groove with a partial edge, the rake angle is increased to reduce cutting resistance and improve feed efficiency. This not only improves the versatility of standard tools and reduces tool customization and usage costs, but also balances machining stability and overall operating efficiency during step-by-step cutting, contributing to improved final forming quality of large-diameter sealing grooves. Attached Figure Description

[0016] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0017] Figure 1 This is a schematic diagram of the tool holder in one or more embodiments of the present invention.

[0018] Figure 2 This is a schematic diagram of a tool holder in one or more embodiments of the present invention.

[0019] Figure 3 This is a schematic diagram of a marine engine cylinder block sealing groove machining device in one or more embodiments of the present invention.

[0020] In the figure, 1 is the rotary drive unit; 2 is the fixed part; 3 is the tool holder; 4 is the locking groove; 5 is the boring tool; 6 is the counterweight unit; 7 is the counterweight block; 8 is the fixed base; and 9 is the locking hole. Detailed Implementation

[0021] Example 1 In a typical embodiment of the present invention, such as Figure 1 - Figure 3 As shown, a machining device for sealing grooves in marine engine cylinder blocks is presented.

[0022] Existing boring devices rely on expensive custom-made tools when machining non-standard sized sealing grooves. Furthermore, when using standard narrow-blade tools for multiple step-by-step grooving operations, the fixed rake angle makes it difficult to balance the drastically different stress conditions of heavy cutting on the entire cutting edge and light cutting on the side edges, easily leading to cutting vibration, reduced efficiency, and poor groove wall quality. Therefore, this embodiment provides a machining device for marine engine cylinder block sealing grooves. Through the sliding and rotating structure of the tool holder 3, the rotational machining radius and rake angle of the boring tool 5 can be dynamically adjusted to adapt to the cutting requirements of different machining stages. This solves the problems of poor machining quality and low efficiency in existing technologies. It allows for flexible adjustment of the rotational machining radius and rake angle of the boring tool 5, thereby improving machining efficiency, reducing tool costs, and improving the surface quality and geometric accuracy of the groove.

[0023] like Figures 1-3 As shown, the machining device for the sealing groove of the marine engine cylinder block mainly includes a tool holder, a fixed seat 8, and a tool holder 3. The tool holder is capable of rotation and is provided with a rotation drive part 1 and a fixed part 2. The rotation drive part 1 extends radially along the rotation axis and connects to the fixed part 2. The fixed seat 8 is mounted on the fixed part 2 and has a sliding hole. The tool holder 3 is detachably mounted with a boring bar 5. The tool holder 3 forms a sliding fit with the sliding hole and is fitted with a locking element. The tool holder 3 slides axially relative to the sliding hole to adjust the rotation machining radius of the boring bar 5, and / or, the tool holder 3 rotates axially relative to the sliding hole to adjust the rake angle of the machining position of the boring bar 5.

[0024] It should be noted that the boring tool 5 is a cutting tool used for finishing holes or grooves.

[0025] After the tool holder 3 is adjusted to the desired position, the locking element is fixed relative to the sliding hole. The locking element typically achieves its locking function through mechanical friction, threaded fastening, or pin insertion.

[0026] The rotary machining radius refers to the radius of the circular trajectory formed by the tip of the boring bar during its rotary motion. By adjusting this radius, the diameter of the machined sealing groove can be controlled.

[0027] The rake angle is the angle between the rake face of the fifth cutting edge of a boring bar and the reference plane. The size of the rake angle affects the cutting force, chip formation, tool life, and the quality of the machined surface.

[0028] like Figure 1 As shown, the tool holder can adopt an integral molding structure and be mounted on the machine tool spindle via the rotary drive unit 1, thereby driving the tool holder to rotate by the machine tool spindle. The fixed seat 8 is a base-type structure and is connected to the tool holder by welding, fastener assembly, integral molding, etc., to ensure that there is no relative movement between the fixed seat 8 and the tool holder, and to meet the requirement of smooth transmission of driving torque during rotary machining.

[0029] The tool holder's fixing part 2 can have pre-drilled bolt holes and a limiting groove. The bottom size and shape of the fixing seat 8 match the limiting groove, allowing it to be inserted into the limiting groove and secured with bolts or other fasteners. Alternatively, the fixing seat 8 can be welded in place after being inserted into the limiting groove.

[0030] The sliding hole provided on the fixed seat 8 can be formed by machining before installation onto the tool holder, by drilling or boring with a drilling machine or boring machine. The inner wall of the sliding hole is smooth and the roundness can meet the requirements of sliding and rotating fit with the tool holder 3.

[0031] The tool holder 3 is a cylindrical rod. The boring bar 5 is fixed to one end of the tool holder 3 with screws. The tool holder 3 is inserted into the sliding hole and is tightened by a locking member screwed into the side of the fixing seat 8. Optionally, the cylindrical rod of the tool holder 3 can be provided with a flat surface. The boring bar 5 is mounted on the tool holder 3 by a clamping mechanism. After the tool holder 3 is inserted into the sliding hole, the locking member abuts against the flat surface to lock the tool holder 3.

[0032] like Figure 3 As shown, the tool holder 3 slides axially relative to the sliding hole, thereby changing the radial distance of the boring bar 5 extending from the tool holder to adjust the turning radius of the boring bar 5. Simultaneously, the tool holder 3 rotates axially relative to the sliding hole, thereby changing the orientation of the cutting edge of the boring bar 5 relative to the workpiece to adjust the rake angle of the boring bar 5's machining position. After adjustment, the tool holder 3 is fixed by a locking mechanism.

[0033] The marine engine cylinder block sealing groove machining device proposed in this embodiment achieves flexible adjustment of the boring bar 5's rotation radius and rake angle through axial sliding and rotation of the tool holder 3 within the sliding hole. Therefore, when machining non-standard sealing grooves, there is no need to customize a special boring bar 5, reducing tool costs. Simultaneously, the cutting parameters of the boring bar 5 can be adjusted according to the cutting requirements of different machining stages, effectively avoiding chipping during heavy cutting and poor cutting during light cutting, thus improving machining efficiency and groove wall surface quality.

[0034] In actual machining, because the rotary drive unit 1 of the tool holder extends radially along the rotation axis and connects to the fixed part 2, and the fixed part 2 is equipped with components such as the tool holder 3 and the boring tool 5, the tool holder is prone to significant imbalance during high-speed rotation, which in turn causes vibration and affects machining accuracy and equipment stability. To address this, in this embodiment, the rotary drive unit 1 is also connected to a counterweight unit 6. The counterweight unit 6 and the fixed part 2 are located on opposite sides of the rotation axis, and a counterweight block 7 is installed on the counterweight unit 6 to balance the overall mass distribution of the tool holder.

[0035] The counterweight 7 rotates with the tool holder, providing a balancing torque during rotation. The connection between the counterweight 7 and the counterweight part 6 can be rigid, such as by bolts, welding, or integral molding, to ensure that the counterweight part 6 does not undergo relative displacement during high-speed rotation. By positioning the counterweight part 6 on the opposite side of the rotation axis, forming a lever arm opposite to the fixed part 2, the eccentric mass generated by the fixed part 2 and its supported components can be effectively counteracted. The counterweight part 6 and the fixed part 2 are arranged symmetrically or approximately symmetrically with respect to the tool holder's rotation axis, ensuring that the center of gravity of the entire rotating assembly falls as close as possible to the rotation axis, thereby reducing or eliminating unbalanced torque.

[0036] The mass, shape, and installation position of the counterweight 7 can be precisely calculated and adjusted according to actual dynamic balancing requirements. The counterweight 7 can be made of high-density material and installed on the counterweight part 6 by bolts, slots, or press-fitting. To achieve adjustable balancing, the counterweight 7 can be set to be adjustable or replaceable, for example, by increasing or decreasing the number of counterweights 7, changing their installation position, or using counterweights 7 of different masses, to adapt to the balancing requirements under different tool configurations or machining parameters.

[0037] In actual machining processes, especially when subjected to large cutting forces, if the locking effect of the locking components is insufficient, small axial or circumferential displacements can easily occur, thus affecting machining accuracy.

[0038] In this embodiment, the fixed base 8 is provided with multiple locking holes 9 that connect to the sliding holes, providing a channel for the insertion of the locking member, so that the locking member can pass through the locking holes 9 and contact the tool bar 3. The locking holes 9 are spaced apart along the axial direction of the sliding hole, and at least two locking holes 9 are staggered along the circumferential direction, providing multiple preset locking points for the axial and circumferential positions of the tool bar 3. The outer circumference of the tool bar 3 is provided with locking grooves 4 distributed along the generatrix direction. After the locking member cooperates with the locking holes 9, it is inserted into the locking grooves 4 to lock the axial and circumferential positions of the tool bar 3 relative to the sliding hole.

[0039] The locking holes 9 are distributed at a certain interval along the axial direction of the sliding hole, which can reduce the number of locking holes 9 in a single axial position, keep the locking holes 9 at a suitable distance, and prevent the locking parts that the locking holes 9 mate with from causing improper interference during operation.

[0040] On the fixed base 8, at least two locking holes 9 are staggered along the circumferential direction of the sliding hole, so that when the tool holder 3 rotates circumferentially within the sliding hole, it can be locked at multiple discrete circumferential angles. By selecting different circumferentially staggered locking holes 9 for locking, the rake angle of the boring tool 5 at the machining position can be precisely adjusted to optimize cutting performance and surface quality.

[0041] The outer circumferential surface of the tool holder 3 is provided with locking grooves 4 distributed along its generatrix direction, that is, the distribution direction of the locking grooves 4 is parallel to the axial direction of the tool holder 3. The locking grooves 4 cooperate with the locking holes 9, and when the locking element is inserted into the locking grooves 4, a mechanical limit can be formed. The distribution along the generatrix direction ensures that after locking the circumferential position of the tool holder 3, the tool holder 3 can still be axially slidably adjusted, thereby adapting to the machining requirements of using the same rake angle for different machining radii.

[0042] The locking element extends into the locking groove 4 on the outer circumference of the tool holder 3 through the locking hole 9 on the fixed base 8, forming a mechanical interlocking structure. The end of the locking element enters the groove, thereby preventing the tool holder 3 from moving axially and circumferentially within the sliding hole. Through the synergistic action of the locking hole 9, the locking groove 4, and the locking element, the axial and circumferential positions of the tool holder 3 relative to the sliding hole can be precisely locked. Axial locking ensures the stability of the boring tool 5's rotational machining radius, while circumferential locking ensures the accuracy of the boring tool 5's rake angle, stably controlling the boring machining parameters.

[0043] To improve the rigidity and stability of the tool holder 3's positioning, this embodiment sets the locking groove 4 and the locking element inserted therein as an interference fit. The actual size of the locking element is slightly larger than the corresponding size of the locking groove 4, thereby generating radial pressure when the two are engaged, forming a tight, gapless connection. Specifically, the locking end size of the locking element and the width or depth size of the locking groove 4 can be precisely controlled to achieve the expected interference within the tolerance range. The locking end of the locking element can be cylindrical, with its diameter or characteristic size slightly larger than the corresponding size of the locking groove 4. During assembly, the locking element is pressed into or screwed into the locking groove 4, generating a fastening force through the elastic deformation of the material.

[0044] When the tool holder 3 is adjusted to the required axial and circumferential positions, the corresponding locking holes 9 and locking grooves 4 align. Multiple locking holes 9 located in the same circumferential position simultaneously engage with locking components, which extend into the locking grooves 4 to constrain the position of the tool holder 3, forming multi-point locking. This improves the stability of the axial and circumferential positioning of the tool holder 3. The locking components engaged with other locking holes 9 retract into the locking holes 9, avoiding interference between non-target locking components and the tool holder 3. This ensures that only the preset locking points function, thereby simplifying operation and preventing the positioning accuracy of the tool holder 3 from being affected by misoperation or unnecessary contact.

[0045] Specifically, in this embodiment, the locking hole 9 is a threaded hole, and the locking element is a locking pin with a threaded section. The threaded section mates with the threaded hole, and its axial position is adjusted by rotation. One end of the threaded section of the locking pin is connected to an optical shaft to form a locking end, and its diameter is smaller than that of the threaded section, allowing the locking end to retract smoothly into the threaded hole. The other end is connected to an operating part, configured to accept external force for rotational adjustment. When the locking pin is screwed into the threaded hole, it can generate an axial thrust, thereby achieving the fastening and positioning of the tool holder 3.

[0046] The operating part can be in the form of a handle, knob, hexagonal head, cross groove, or slotted head, etc. Its function is to facilitate the operator to apply external force and rotate the operating part to drive the locking pin to rotate. Rotating the operating part causes the threaded section of the locking pin to screw in or out of the threaded hole, thereby realizing the engagement or disengagement of the locking end with the locking slide 4, as well as the adjustment of the locking degree.

[0047] By adjusting the axial sliding and rotation of the tool holder 3 relative to the sliding hole, the machining radius and rake angle of the boring bar 5 are changed. However, in order to ensure the machining effect, in addition to adjusting the changes in the machining radius and rake angle of the boring bar 5, different cutting speeds are also matched to it to ensure machining quality and efficiency. Specifically, the marine engine cylinder block sealing groove machining device also includes a drive spindle, which is connected to the rotary drive unit 1 and can adjust the speed according to the machining radius and rake angle.

[0048] The drive spindle typically consists of a motor and a corresponding transmission mechanism. The output end of the drive spindle is mechanically connected to the rotary drive unit 1 of the tool holder, thereby driving the boring tool 5 to perform rotary cutting. The connection between the drive spindle and the rotary drive unit 1 of the tool holder can adopt various forms such as direct coupling, gear meshing, or synchronous belt drive to meet the requirements of different machining accuracy and torque transmission.

[0049] During machining, when the machining radius or rake angle of the boring bar 5 changes, the optimal spindle speed matching the current machining conditions can be calculated in real time based on preset machining strategies or empirical parameters, and the spindle speed can be adjusted accordingly. For example, when the machining radius increases, if a constant cutting speed needs to be maintained, the spindle speed will decrease accordingly; conversely, when the machining radius decreases, the speed will increase. Similarly, changes in the rake angle also affect cutting force, cutting heat, and chip removal performance, so the cutting conditions need to be optimized by adjusting the speed. For example, when the machining radius increases, the rake angle also increases, and the cutting edge of the boring bar 5 operates locally with low resistance. To improve machining efficiency, the speed can be increased to increase the boring speed.

[0050] In actual processing, relying solely on radial and circumferential adjustments and speed control is insufficient to achieve precise control over the machining depth of the sealing groove. This is especially true when stepped machining is required or when there are strict requirements for the groove depth, which may necessitate frequent machine stops for adjustments, affecting processing efficiency and accuracy.

[0051] In this embodiment, the drive spindle is equipped with a feed mechanism that reciprocates along the rotation axis of the tool holder. The feed mechanism can take various forms; for example, it can be a ball screw pair driven by a servo motor, where the precise control of the servo motor enables the ball screw to rotate, thereby driving the nut connected to the tool holder or drive spindle to move axially. Alternatively, it can be a hydraulic or pneumatic cylinder, where controlling fluid pressure and flow drives the piston rod to extend and retract axially, thus achieving the feed motion of the boring tool 5. It can also be a rack and pinion mechanism, where the rotation of the gear drives the rack to move axially. Regardless of the form used, the core function of the feed mechanism is to provide stable, precise, and controllable axial displacement.

[0052] Along the rotation axis of the tool holder, the boring bar 5 moves parallel to the rotation axis of the tool holder during machining. This allows the boring bar 5 to penetrate deep into the workpiece to machine the bottom or sidewalls of the sealing groove, thereby controlling the machining depth and forming a specific groove shape. The feed mechanism enables the boring bar 5 to move forward and backward cyclically in the axial direction, meeting the needs of cutting feed, tool retraction, and multi-layer or stepped machining.

[0053] Example 2 In another typical embodiment of the present invention, such as Figure 1 - Figure 3 As shown, a method for machining a sealing groove in a marine engine cylinder block is provided, utilizing the machining apparatus for a marine engine cylinder block sealing groove as described in Example 1. The steps include: The tool holder 3 is slid and rotated relative to the sliding hole. The boring tool 5 is adjusted to the first turning radius and the first rake angle and locked by the locking member. Then, it is rotated at the first speed under the drive of the tool holder to bore the basic groove. Unlock the tool holder 3, allowing it to slide and rotate relative to the sliding hole. Adjust the boring tool 5 to the second turning radius and second rake angle, and then relock it. Subsequently, under the drive of the tool holder, rotate at the second rotation speed to bore the side allowance of the base groove to achieve the desired target width. Among them, the second front angle is greater than the first front angle, and the second rotational speed is greater than the first rotational speed.

[0054] Specifically, during the machining process, rough machining is first performed. According to the preset machining program, the tool holder 3 slides axially within the sliding hole of the fixed seat 8 via the drive mechanism to set the rotation radius of the boring bar 5. Simultaneously, the cutting rake angle of the boring bar 5 is adjusted by rotating the tool holder 3 relative to the sliding hole. The first rotation radius is set slightly smaller than the final target width to allow for subsequent finishing. The first rake angle can be selected to be suitable for rough machining and provide good chip removal performance. After adjustment, the tool holder 3 is locked in the set axial and circumferential positions by the locking mechanism. Subsequently, the drive spindle rotates the tool holder at a first rotation speed, causing the boring bar 5 to cut the workpiece, forming the basic groove of the sealing groove. The first rotation speed is usually selected at a relatively low speed to ensure the stability of rough machining and effectively remove a large amount of material.

[0055] After rough machining, the finishing stage begins. First, the tool holder 3 is unlocked by operating the locking mechanism. Next, the tool holder 3 is driven to slide and rotate within the sliding hole, adjusting the boring bar 5 to the second rotation radius and second rake angle. The second rotation radius is set to precisely match the final target width of the sealing groove. A smaller second rake angle is chosen to achieve better surface quality and lower cutting force. After adjustment, the tool holder 3 is securely locked again using the locking mechanism. Subsequently, the spindle is driven to rotate the tool holder at the second rotation speed, performing fine cutting on the side of the base groove until the desired final width is achieved.

[0056] Meanwhile, a higher rotational speed is typically chosen for the second rotational speed to improve finishing efficiency and surface finish. During this process, the second rake angle is set greater than the first rake angle, which helps reduce cutting deformation, lower cutting forces, improve chip removal, and contribute to a smoother machined surface. Furthermore, setting the second rotational speed higher than the first speed improves machining efficiency and helps improve surface finish while reducing tool marks.

[0057] The above technical solution is illustrated below with specific examples: When machining a sealing groove in a large marine engine cylinder block, assuming a circular sealing groove with a diameter of Ø1207mm and a width of 4.5mm is required, traditional machining methods face problems such as high tool customization costs, low machining efficiency, and poor cutting stability. This embodiment utilizes a standard-width boring bar 5 (e.g., 4mm wide) to complete the machining of this non-standard width sealing groove through a step-by-step machining process, optimizing the cutting procedure.

[0058] To machine a 4.5mm wide sealing groove, a 4mm wide base groove needs to be boring first. A standard 4mm wide boring bar 5 is mounted on the tool holder 3. By unlocking the locking mechanism, the tool holder 3 is slid relative to the sliding hole along its axial direction, adjusting the boring bar 5's rotation radius to the first rotation radius, enabling it to bore a base groove with a diameter of Ø1207mm. Simultaneously, the tool holder 3 is rotated relative to the sliding hole along its axial direction, adjusting the boring bar 5's rake angle to the first rake angle. This smaller rake angle accommodates the larger cutting force of the first full-cut operation, preventing chipping.

[0059] After adjustment, the axial and circumferential positions of the tool holder 3 relative to the sliding hole are locked by the locking device. The spindle is driven to rotate the tool holder at a first rotation speed of 5 revolutions per minute according to the set first rotation radius and first rake angle. At the same time, the feed mechanism controls the tool holder to feed along the axial direction at a feed speed of 0.25 mm per minute, and a basic groove with a diameter of Ø1207 mm, a width of 4 mm, and a depth of 3.8 mm is bored out.

[0060] After the basic groove boring is completed, unlock the tool holder 3 and slide it again relative to the sliding hole along the axis of the tool holder 3. Fine-tune the turning radius of the boring bar 5 to the second turning radius so that it can bore the side allowance of 0.5mm of the basic groove to achieve the target width of 4.5mm. At the same time, rotate the tool holder 3 relative to the sliding hole along the axis of the tool holder 3 to adjust the rake angle of the boring bar 5 to the second rake angle. The second rake angle is larger than the first rake angle to accommodate the smaller cutting force of the second step of light side cutting, cutting only 0.5mm of side allowance, improving cutting smoothness and groove wall surface quality.

[0061] After relocking the tool holder 3, the drive spindle rotates the tool post at a second rotation speed (6 revolutions per minute) based on the set second rotation radius and second rake angle, achieving the same machining depth of 3.8mm to bore the side allowance of the base groove. The second rotation speed is higher than the first; the second step is a light cut, using a higher speed to improve machining efficiency and surface finish. By flexibly adjusting the rotation radius and rake angle of the boring bar 5, non-standard width sealing grooves can be machined, reducing the need for custom tools and machining costs.

[0062] Example 3 In another embodiment of this invention, a marine engine is proposed, wherein the sealing groove of its cylinder block is processed by the above-described marine engine cylinder block sealing groove processing method.

[0063] As the main structure of marine engines, the cylinder block currently mostly adopts a segmented structure. Sealing grooves are distributed on the connecting surfaces between adjacent cylinder blocks. These grooves are used to install seals, ensuring effective isolation between the combustion chamber and the cooling water and lubricating oil passages, preventing media leakage. The sealing grooves on the cylinder block are used to accommodate sealing rings or gaskets.

[0064] In this embodiment, the sealing groove on the marine engine cylinder block is obtained through a step-by-step machining method of rough boring the base groove and finish boring the side allowance. This allows for precise control of the sealing groove's size, shape, and surface quality. By adjusting the boring bar 5's rotation radius and rake angle in stages, and coordinating different rotation speeds, problems such as stress concentration, surface damage, or insufficient precision that might occur with single-pass machining can be effectively avoided. In particular, the second rake angle is greater than the first rake angle, and the second rotation speed is greater than the first rotation speed. This allows the finish machining stage to remove the side allowance with less cutting force, higher cutting efficiency, and better surface quality, thereby ensuring that the sealing groove meets the requirements of the marine engine.

[0065] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A machining device for sealing grooves in marine engine cylinder blocks, characterized in that, include: The tool holder is capable of rotating and is equipped with a rotation drive unit and a fixed unit. The rotation drive unit extends radially along the rotation axis and then connects to the fixed unit. A fixed base is installed on the fixed part and has a sliding hole; The tool holder is detachably mounted with a boring bar. The tool holder and the sliding hole form a sliding fit and are fitted with a locking element. The tool holder slides axially relative to the sliding hole to adjust the turning radius of the boring bar, and / or the tool holder rotates axially relative to the sliding hole to adjust the rake angle of the boring bar's machining position.

2. The marine engine cylinder block sealing groove processing device as described in claim 1, characterized in that, The rotary drive unit is also connected to a counterweight unit, which and the fixing unit are located on opposite sides of the rotary axis. A counterweight block is installed on the counterweight unit.

3. The marine engine cylinder block sealing groove processing device as described in claim 1, characterized in that, The fixed base is provided with a plurality of locking holes that are connected to the sliding holes. The locking holes are spaced apart along the axial direction of the sliding holes, and at least two locking holes are staggered along the circumferential direction. The outer circumference of the tool bar is provided with locking grooves distributed along the generatrix direction. After the locking member is engaged with the locking hole, it is inserted into the locking groove to lock the axial and circumferential positions of the tool bar relative to the sliding hole.

4. The marine engine cylinder block sealing groove processing device as described in claim 3, characterized in that, The locking groove and the locking element inserted therein are in an interference fit.

5. The marine engine cylinder block sealing groove processing device as described in claim 3 or 4, characterized in that, Multiple locking holes located in the same circumferential position simultaneously engage locking components, which extend into the locking groove to constrain the position of the tool bar, while the locking components engaged with other locking holes retract into the locking holes.

6. The marine engine cylinder block sealing groove processing device as described in claim 5, characterized in that, The locking hole is a threaded hole, and the locking element is a locking pin with a threaded section. One end of the threaded section of the locking pin is connected to the optical shaft to form a locking end, and the diameter is smaller than that of the threaded section. The other end is connected to an operating part, which is configured to be rotated and adjusted under the action of external force.

7. The marine engine cylinder block sealing groove processing device as described in claim 1, characterized in that, It also includes a drive spindle, which is connected to a rotary drive unit and adjusts the speed according to the rotary machining radius and rake angle.

8. The marine engine cylinder block sealing groove machining device as described in claim 7, characterized in that, The drive spindle is equipped with a feed mechanism that reciprocates along the rotation axis of the tool holder.

9. A method for machining a sealing groove in a marine engine cylinder block, utilizing the machining apparatus for machining sealing grooves in a marine engine cylinder block as described in any one of claims 1-8, characterized in that, The tool holder slides and rotates relative to the sliding hole, the boring tool is adjusted to the first turning radius and the first rake angle, and locked by the locking device. Then, driven by the tool holder, it rotates at the first speed to bore out the basic groove. Unlock the tool holder, allowing it to slide and rotate relative to the sliding hole. Adjust the boring tool to the second turning radius and second rake angle, and then relock it. Subsequently, rotate it at the second rotation speed under the drive of the tool post to bore the side allowance of the base groove to achieve the desired target width. Among them, the second front angle is greater than the first front angle, and the second rotational speed is greater than the first rotational speed.

10. A marine engine, characterized in that, The sealing groove on the cylinder block is obtained by the machining method for the sealing groove of the marine engine cylinder block as described in claim 9.

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