A fixing tool for dismounting medium-speed diesel engine connecting rod bearing bush

Abstract

The application discloses a kind of medium-speed diesel engine connecting rod bearing bush dismounting with fixed tool, belong to diesel engine maintenance equipment technical field.The tool includes base fixed component, adjusting assembly, compensation mechanism, connecting arm component and connecting rod end support component.Base fixed component is installed in rack observation hole by fixed plate, adjusting assembly realizes length adjustment by the cooperation of hinged adjusting slide bar and adjusting sliding groove, and utilizes the compensation mechanism of shaft jointing cubic block, fixed clamp block and movable clamp block to realize multi-degree-of-freedom alignment;Connecting arm is connected with sliding groove by flat head hole pin to avoid space interference;Support component end is equipped with rubber pad and nylon head, and is equipped with 15 ° inclination support plate and reinforcing block.The application is light in structure, can be flexibly adjusted to compensate connecting rod position deviation;Realize the dismounting of connecting rod bearing bush under the condition of not disassembling cylinder cover, greatly reduce labor intensity, improve maintenance efficiency, have very high practical value.

Description

Technical Field

[0001] This invention relates to the field of special tools for diesel engine repair, specifically to a connecting rod fixing fixture used in the process of disassembling connecting rod bearings in medium-speed diesel engines. Background Technology

[0002] Diesel engines are the core power units of ships, construction machinery, and large transportation equipment. Their working environment is typically characterized by high loads and high temperatures, leading to severe wear on internal moving parts. Connecting rod bearings are critical sliding support components connecting the connecting rod and the crankshaft, and must be regularly inspected or replaced during major or intermediate diesel engine overhauls.

[0003] In current maintenance operations, it is usually necessary to fix the connecting rod in a specific position to facilitate the removal of the bearing shell. However, the traditional tooling commonly used in the industry is a fixed structure, which has the following significant drawbacks in practical applications: 1. Bulky structure and high operating space requirements: Traditional tooling is bulky and heavy, making installation and disassembly extremely laborious. Due to the limited internal space of the engine compartment of medium-speed diesel engines, the bulky tooling makes installation extremely inconvenient and increases the labor intensity of workers.

[0004] 2. Poor adaptability and insufficient adjustment capability: Since there may be slight deviations in the position of the connecting rod in different cylinder positions of a diesel engine, traditional fixed tooling lacks the degree of adjustment freedom and cannot adapt to these deviations, often resulting in the inability to effectively clamp the connecting rod or even complete the disassembly operation smoothly.

[0005] 3. Cumbersome procedures and high maintenance costs: Before using traditional tooling, maintenance personnel must first disassemble the cylinder head and fuel injection mechanism of the diesel engine. This not only adds a large number of extra work steps, but also takes a very long time. Taking a 270 series diesel engine as an example, it usually requires 4 to 5 skilled workers to complete the disassembly of all connecting rod bearings using traditional tooling, which takes about 2.5 days, resulting in high labor and time costs.

[0006] 4. Frequent crankshaft rotation is required: Existing technologies often require repeated crankshaft rotation to match the tooling position, which increases operational risks and equipment wear.

[0007] Therefore, there is an urgent need to develop a new type of tooling that is lightweight, flexible in adjustment, and can complete the disassembly of the connecting rod lower bearing without disassembling the cylinder head. Summary of the Invention

[0008] The purpose of this invention is to address the problems of existing diesel engine connecting rod bearing removal fixtures, such as large weight, lack of adjustability, requirement to disassemble the cylinder head and injector structure, and low maintenance efficiency, by providing a medium-speed diesel engine connecting rod fixing fixture. This fixture can flexibly adjust the support angle and position, achieving rapid and stable support for the connecting rod, significantly reducing labor intensity and shortening the maintenance cycle.

[0009] To achieve the above objectives, the technical solution of the present invention is as follows: A fixing tool for disassembling and assembling connecting rod bearings of a medium-speed diesel engine includes a base fixing assembly, a compensation mechanism, an adjustment assembly, a connecting arm assembly, and a connecting rod end support assembly.

[0010] The base mounting assembly includes a mounting plate and a mounting shaft. The mounting plate is used for detachable mounting to the inspection hole of the diesel engine frame, thereby allowing the tooling to be installed on the outside of the frame without removing the cylinder head. The mounting shaft extends laterally through and is fixed to the mounting plate, providing a hinge reference for subsequent components.

[0011] A compensation mechanism is disposed between the base fixing assembly and the adjusting assembly to compensate for positional deviations of the connecting rod in multiple degrees of freedom. Specifically, the compensation mechanism includes a shaft-connected cube, a fixed clamping block, a movable clamping block, an adjusting screw, and a positioning block. The fixed clamping block is fixed to the fixed plate, and the movable clamping block is closed and connected to the fixed clamping block to form a receiving cavity. The cylindrical portions at both ends of the shaft-connected cube are rotatably connected to the receiving cavity, forming a universal adjustment structure, allowing the shaft-connected cube to swing relative to the fixed plate in multiple directions. The adjusting screw passes through the shaft-connected cube and is connected to the positioning block. By rotating the adjusting screw, the positioning block can be driven to make linear displacement along the axial direction, achieving precise compensation for the support position.

[0012] The adjustment assembly includes a hinged adjusting slide rod and an adjusting slide groove. One end of the hinged adjusting slide rod is hinged to the fixed shaft, allowing the slide rod to swing about the fixed shaft in a vertical plane. The slide rod has a guide groove along its length, and the adjusting slide groove is slidably connected to the hinged adjusting slide rod by fasteners passing through the guide groove. This allows adjustment of the extension length of the adjusting slide groove relative to the hinged adjusting slide rod to accommodate the distance requirements of the connecting rod at different crankshaft rotation angles.

[0013] A connecting arm assembly connects the compensation mechanism and the adjusting assembly. Specifically, the connecting arm assembly includes a connecting arm and a flat-headed pin with a hole. One end of the connecting arm is fixedly connected to the adjusting block, and the other end of the connecting arm is hinged to the adjusting slide groove via the flat-headed pin with a hole. Using a flat-headed pin with a hole instead of conventional bolts and nuts can effectively shorten the radial dimension of the connection and avoid spatial interference with the connecting rod or crankshaft in the narrow crankcase.

[0014] A connecting rod end support assembly is fixedly mounted at the end of the adjusting slide groove to directly support the connecting rod. The support assembly includes a support plate, which is welded to the end of the adjusting slide groove, with a preset inclination angle of 15° between them to ensure optimal force contact between the support surface and the lower part of the connecting rod. The support surface of the support plate has a protective contact structure, including a rubber pad laid on the support surface and a nylon head fixed to the support plate by screws. Together, they form a flexible support surface that provides stable support force while preventing damage to the machined surface of the connecting rod.

[0015] Furthermore, the fixed clamping block and the movable clamping block are connected by hexagonal socket screws; the cylindrical portions at both ends of the axially connected cube are clamped within the cylindrical receiving cavity formed after the fixed clamping block and the movable clamping block are joined, and can rotate in multiple directions relative to the receiving cavity. This structure is simple and compact, and achieves universal adjustment.

[0016] Furthermore, the connecting arm assembly also includes a pin hole plate and a cotter pin. The pin hole plate is fixedly mounted on the adjusting slide groove. The flat-headed pin with a hole passes sequentially through the end of the connecting arm and the pin hole plate. The cotter pin passes through the hole at the end of the flat-headed pin with a hole, forming a mechanical anti-loosening locking structure to prevent the pin from falling off under vibration.

[0017] Furthermore, a reinforcing block is fixedly provided below the support plate. The reinforcing block is fixedly connected to the support plate and the adjusting slide groove respectively, in order to enhance the bending stiffness of the support plate when bearing load and prevent structural deformation.

[0018] Furthermore, the fasteners between the hinged adjusting slide rod and the adjusting slide groove include a bolt and a nut. The bolt passes through the guide groove of the hinged adjusting slide rod and the corresponding hole of the adjusting slide groove, and is threadedly connected to the nut. By tightening or loosening the nut, the sliding unlocking and locking of the adjusting slide groove and the hinged adjusting slide rod can be achieved.

[0019] Furthermore, the adjusting screw and the adjusting block are connected by a thread. By rotating the adjusting screw, the adjusting block can be driven to make linear displacement along the axial direction of the adjusting screw, thereby realizing micro-feeding.

[0020] Compared with the prior art, the beneficial effects of the present invention are: 1. Simplified maintenance procedures and significantly improved efficiency: The entire disassembly process does not require the removal of the cylinder head and fuel injection mechanism, significantly shortening maintenance time. Actual testing shows that maintenance efficiency can be improved by more than 50% compared to traditional tooling.

[0021] 2. Lightweight design reduces labor intensity: The tooling is compact and can be used flexibly within the limited internal space of the diesel engine. Its weight is reduced by 40% compared to traditional tooling, and a single person can easily complete the handling and installation operations.

[0022] 3. Flexible adjustment and strong versatility: The tooling adopts a combination structure of sliding rod and hinge, which can adapt to the slight positional differences of different models of diesel engines and different cylinder positions of the same engine, solving the pain point of traditional fixed tooling that "cannot be locked tight or can not be inserted".

[0023] 4. Safety protection: The contact surfaces are made of nylon and rubber, which effectively avoids damage to the connecting rod and bearings caused by improper operation. According to statistics, the damage rate of related parts has been reduced by more than 80%. Attached Figure Description

[0024] Figure 1 This is one of the schematic diagrams of the overall structure of the fastener for disassembling and assembling the connecting rod bearing of a medium-speed diesel engine according to the present invention; Figure 2 This is the second schematic diagram of the overall structure of the fastener for disassembling and assembling the connecting rod bearing of the medium-speed diesel engine according to the present invention; Figure 3 This is one of the schematic diagrams illustrating the use of the fixing tool for disassembling and assembling the connecting rod bearing of a medium-speed diesel engine according to the present invention; Figure 4 This is the second schematic diagram of the application scenario of the fixing tool for disassembling and assembling the connecting rod bearing of the medium-speed diesel engine according to the present invention.

[0025] The following are the labels in the diagram: 1. Fixed plate; 2. Fixed shaft; 3. Hinge adjusting slide bar; 4. Fixed clamping block; 5. Movable clamping block; 6. M6 socket head cap screw; 7. Adjusting screw; 8. Shaft connecting cube block; 9. Adjusting block; 10. M12 bolt; 11. Connecting arm; 12. M10 bolt; 13. Adjusting slide groove; 14. Rubber pad; 15. Nylon head; 16. M10 socket head cap screw; 17. Support plate; 18. Reinforcing block; 19. Cotter pin; 20. Pin hole plate; 21. Flat head pin with hole; 22. M10 nut. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0027] Please see Figures 1 to 4 This invention provides a preferred embodiment of a fixing tool for disassembling and assembling connecting rod bearings in a medium-speed diesel engine. The fixing tool comprises five main functional modules: a base fixing assembly, a compensation mechanism, an adjustment assembly, a connecting arm assembly, and a connecting rod end support assembly. These will be described in detail below.

[0028] like Figure 1 and Figure 2 As shown, the base fixing assembly mainly includes a fixing plate 1 and a fixing shaft 2. The fixing plate 1 serves as the mounting base for the overall tooling of this invention, and its external dimensions match the specifications of the observation hole on the diesel engine frame. In actual operation, the operator uses multiple (e.g., four) M12 bolts to fasten the fixing plate 1 to the observation hole on the diesel engine frame, thereby providing a stable and reliable reference support for the entire tooling. The fixing shaft 2 extends laterally through and is fixed to the fixing plate 1, with its extension direction approximately perpendicular to the mounting plane of the fixing plate 1. This fixing shaft 2 is used to achieve a hinged connection with the subsequent adjustment assembly, providing the tooling with initial rotational freedom. The fixing plate 1, as the mounting base for the entire tooling, is shaped according to the specifications of the diesel engine observation hole. In actual operation, the fixing plate 1 is fixed to the frame using four bolts. The fixing shaft 2 extends laterally through the fixing plate 1 and is hinged to the bottom end of the hinged adjusting slide rod 3. This hinged structure allows the slide rod to swing at an angle in the vertical plane.

[0029] like Figure 1 and Figure 2 As shown, the compensation mechanism is disposed between the base fixing assembly and the adjusting assembly, and is used to compensate for positional deviations of the connecting rod caused by manufacturing, installation, or differences in different cylinder positions in multiple degrees of freedom. In this preferred embodiment, the compensation mechanism specifically includes a shaft-connected cubic block 8, a fixed clamping block 4, a movable clamping block 5, an adjusting screw 7, and an adjusting block 9.

[0030] The fixed clamping block 4 is preferably fixed to the fixed plate 1 by welding. The movable clamping block 5 is connected to the fixed clamping block 4 by M6 socket head cap screws 6, forming a cavity with cylindrical receiving spaces at both ends when they are closed. The main body of the axially connected cubic block 8 is cubic in shape, with cylindrical protrusions extending outward from its left and right ends. These cylindrical protrusions are rotatably connected to the receiving cavities formed by the fixed clamping block 4 and the movable clamping block 5 when they are closed, thus forming a multi-angle adjustment structure similar to a universal joint. This structure allows the axially connected cubic block 8 to be adjusted in multiple directions, such as pitch and yaw, relative to the fixed plate 1.

[0031] The adjusting screw 7 passes through the shaft-connected cube 8, and its front end is connected to the adjusting block 9. Specifically, the adjusting screw 7 and the adjusting block 9 can be connected by a threaded connection or a rotary connection, so that when the operator rotates the adjusting screw 7, the adjusting block 9 can be precisely pushed or pulled to make a small linear displacement, thereby achieving fine compensation for the front end support position.

[0032] The hinged adjusting slide rod 3 and the adjusting slide groove 13 constitute the main telescopic mechanism of the tooling. The hinged adjusting slide rod 3 has a guide groove on its body, and is connected to the adjusting slide groove by two sets of bolts 12 and nuts 22 passing through the guide groove. By loosening and sliding the nuts 22, the operator can precisely adjust the extension length of the adjusting slide groove 13 relative to the slide rod 3 to adapt to the support distance requirements of the diesel engine at different crankshaft angles.

[0033] To compensate for deviations in the connecting rod's position in three-dimensional space, this device incorporates a complex compensation mechanism at the front end: a fixed clamping block 4 is welded to a fixed plate 1 and engages with a movable clamping block 5 via M6 hexagonal socket screws 6. The two cylindrical ends of a shaft-connected cubic block 8 are rotatably connected to this engaging structure, forming an adjustment mechanism similar to a universal joint. An adjusting screw 7 is connected to an adjusting block 9 via the shaft-connected cubic block 8; rotating the screw allows for fine-tuning of the small displacements of the front-end support assembly.

[0034] The compensation mechanism and the telescopic assembly are connected via a connecting arm 11. One end of the connecting arm 11 is connected to the adjusting block 9 via an M12 bolt 10. The other end of the connecting arm 11 is connected to the adjusting groove 13 via a flat-headed pin with a hole 21, a pin hole plate 20, and a cotter pin 19. Key improvement: Compared to conventional bolts and nuts, the use of a flat-headed pin with a hole 21 significantly reduces the physical dimensions of the connection, effectively avoiding physical interference with connecting rods or crankshafts within the limited engine compartment space.

[0035] The tooling's execution end is a support assembly, which is welded and fixed to the adjusting slide 13 via a support plate 17, maintaining a specific inclination angle of 15° between them. This angle has been optimized through actual working condition simulation to ensure optimal stress contact between the support surface and the lower part of the connecting rod. A reinforcing block 18 is welded below the support plate 17 to prevent bending deformation of the support plate when the connecting rod is under stress. A rubber pad 14 is laid on the support surface, and a nylon head 15 is fastened to the support plate with two M10 hex socket screws 16. This combination of soft and hard design provides sufficient support force while ensuring that the contact surface of the connecting rod is not scratched.

[0036] Combination Figure 3 and Figure 4 The following details the specific operating steps for disassembling and assembling the connecting rod bearing of a medium-speed diesel engine using the above preferred embodiment: Step 1: Fixture Installation. First, the operator does not need to disassemble the diesel engine cylinder head and fuel injection mechanism. Simply open the inspection hole cover on the side of the diesel engine frame, align the fixing plate 1 with the mounting plane of the inspection hole, and secure the entire fixture base to the engine frame housing using four M12 bolts (e.g., Figure 3 (As shown).

[0037] Step 2: Position Adjustment and Alignment. Based on the specific position of the connecting rod where the bearing bush needs to be disassembled, the operator performs the following adjustments: Loosen the M10 nut 22, slide the adjusting groove 13 along the guide groove of the hinged adjusting slide rod 3, and roughly adjust the extension length of the support assembly; simultaneously, utilizing the hinge structure between the hinged adjusting slide rod 3 and the fixed shaft 2, as well as the universal adjustment function of the shaft-connected cube block 8 in the compensation mechanism, to roughly align the posture of the support plate 17 with the support part at the lower part of the connecting rod; then, rotate the adjusting screw 7, driving the adjusting block 9 and the connecting arm 11 to perform micron-level precision micro-feeding, so that the rubber pad 14 and nylon head 15 on the support plate 17 are tightly fitted with the area around the threaded hole of the connecting rod (e.g., Figure 4 (As shown). Because this invention has multi-degree-of-freedom compensation capabilities, it can easily adapt to three-dimensional position deviations of the connecting rod.

[0038] Step 3: Locking and Operation. After the support assembly and connecting rod reach the ideal fit, tighten the M10 nut 22 to lock the adjusting slide 13 and the hinged adjusting slide 3, while ensuring all fasteners are locked. At this point, the fixture provides a stable and rigid support for the connecting rod. Subsequently, the operator can rotate the crankshaft at a small angle. With the reliable support of the fixture, the connecting rod and the crankshaft bearing will separate relative to each other, allowing maintenance personnel to easily and safely complete the bearing disassembly.

[0039] Step 4: Tooling disassembly. After the operation is completed, loosen the M10 nut 22, rotate the adjusting screw 7 in the opposite direction to separate the support assembly from the connecting rod, and finally remove the fixing bolts on the observation hole of the fixing plate 1 on the frame. The entire tooling can then be removed from the diesel engine as a whole, without leaving any parts in the crankcase.

[0040] In summary, the connecting rod bearing removal and fixing tool for medium-speed diesel engines provided by this invention, through the organic cooperation of a base fixing component, a multi-degree-of-freedom compensation mechanism, a telescopic adjustment component, a compact connecting arm, and a flexible end support component, achieves rapid, precise, and stable support of the connecting rod under the harsh condition of not disassembling the cylinder head. Its lightweight structure, flexible adjustment, and strong adaptability significantly reduce maintenance labor intensity, improve work efficiency, and effectively protect the supported components, possessing extremely high practical value and market potential.

[0041] The above are merely embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A fixing tool for disassembling and assembling connecting rods and connecting rod bearings in a medium-speed diesel engine, characterized in that... include: The base fixing assembly includes a fixing plate (1) and a fixing shaft (2); the fixing plate (1) is used to be detachably fixed to the observation hole of the diesel engine frame, and the fixing shaft (2) extends laterally through and is fixed to the fixing plate (1). The compensation mechanism includes a shaft-connected cubic block (8), a fixed clamping block (4), a movable clamping block (5), an adjusting screw (7), and an adjusting block (9); the fixed clamping block (4) is fixed on the fixed plate (1), the movable clamping block (5) is closed and connected to the fixed clamping block (4) to form a receiving cavity, and the cylindrical parts at both ends of the shaft-connected cubic block (8) are rotatably connected to the receiving cavity to form a universal adjustment structure; the adjusting screw (7) passes through the shaft-connected cubic block (8) and is connected to the adjusting block (9); The adjustment assembly includes a hinged adjustment slide rod (3) and an adjustment groove (13); one end of the hinged adjustment slide rod (3) is hinged to the fixed shaft (2), the body of the hinged adjustment slide rod (3) is provided with a guide groove along the length direction, and the adjustment groove (13) is slidably connected to the hinged adjustment slide rod (3) through the guide groove by fasteners, so as to adjust the extension length of the adjustment groove (13) relative to the hinged adjustment slide rod (3); The connecting arm assembly includes a connecting arm (11) and a flat-headed pin with a hole (21); one end of the connecting arm (11) is fixedly connected to the adjusting block (9), and the other end of the connecting arm (11) is hinged to the adjusting slide (13) through the flat-headed pin with a hole (21); The connecting rod end support assembly is fixedly installed at the end of the adjusting slide (13) and is used to directly support the connecting rod.

2. The medium-speed diesel engine connecting rod fixing fixture according to claim 1, characterized in that: The fixed clamping block (4) and the movable clamping block (5) are connected by an internal hexagonal screw (6); the cylindrical portions at both ends of the axially connected cubic block (8) are clamped in the cylindrical receiving cavity formed after the fixed clamping block (4) and the movable clamping block (5) are closed, and can rotate in multiple directions relative to the receiving cavity.

3. The medium-speed diesel engine connecting rod fixing fixture according to claim 1, characterized in that: The connecting arm assembly also includes a pin hole plate (20) and a cotter pin (19); the pin hole plate (20) is fixedly mounted on the adjusting slide (13), the flat-headed pin with a hole (21) passes through the end of the connecting arm (11) and the pin hole plate (20) in sequence, and the cotter pin (19) passes through the hole at the end of the flat-headed pin with a hole (21), forming a mechanical anti-loosening locking structure.

4. The medium-speed diesel engine connecting rod fixing fixture according to claim 1, characterized in that: The connecting rod end support assembly includes a support plate (17), which is welded and fixed to the end of the adjusting slide (13), and a preset tilt angle of 15° is provided between the support plate (17) and the adjusting slide (13).

5. The connecting rod fixing fixture for a medium-speed diesel engine according to claim 4, characterized in that: Place A reinforcing block (18) is fixedly provided below the support plate (17). The reinforcing block (18) is fixedly connected to the support plate (17) and the adjusting slide (13) respectively, and is used to enhance the bending stiffness of the support plate (17).

6. The connecting rod fixing fixture for a medium-speed diesel engine according to claim 4, characterized in that: The support plate (17) has a protective contact structure on its support surface. The protective contact structure includes a rubber pad (14) laid on the support surface of the support plate (17) and a nylon head (15) fixed to the support plate (17) by screws. The rubber pad (14) and the nylon head (15) together form a flexible support surface for direct contact with the connecting rod surface.

7. The connecting rod fixing fixture for a medium-speed diesel engine according to claim 1, characterized in that: The fasteners between the hinged adjusting slide (3) and the adjusting slide (13) include a bolt (12) and a nut (22); the bolt (12) passes through the guide groove of the hinged adjusting slide (3) and the corresponding hole of the adjusting slide (13) and is threaded to the nut (22). By tightening or loosening the nut (22), the sliding unlocking and locking between the adjusting slide (13) and the hinged adjusting slide (3) can be achieved.

8. The fixing tool for disassembling and assembling connecting rod bearings of a medium-speed diesel engine according to claim 1, characterized in that: The adjusting screw (7) and the adjusting block (9) are connected by a thread. By rotating the adjusting screw (7), the adjusting block (9) can be driven to make linear displacement along the axial direction of the adjusting screw (7).

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