Double-shaft synchronous tightening equipment for flange plate bolt of cam shaft of marine diesel engine

Abstract

The invention discloses marine diesel engine camshaft flange plate bolt double-shaft synchronous tightening equipment which comprises a double-tightening mechanism matched with a flange to be tightened in a camshaft box, and the double-tightening mechanism comprises two tightening tools capable of being held on a camshaft in the camshaft box; each tightening mechanism comprises at least two tightening execution units which are symmetrically arranged along the cam shaft; the double-tightening mechanism is provided with an adjusting mechanism used for adjusting the height of the double-tightening mechanism and controlling the double-tightening mechanism to rotate. A positioning mechanism for confirming the initial position of the double-tightening mechanism is arranged on the double-tightening mechanism and the flange to be tightened; the adjusting mechanism comprises an indexing mechanism and a supporting platform. The indexing mechanism is connected with the two tightening tools of the double-tightening mechanism and drives the two tightening tools to rotate synchronously. The indexing mechanism is arranged on a supporting platform of which the height can be adjusted; the equipment can effectively deal with a narrow space of a camshaft box of a marine diesel engine, a center belt shaft structure, a cam and a circular flange plate which need to be processed at the same time and meet the high-quality synchronous tightening process requirement.

Description

Technical Field

[0001] This invention relates to bolt tightening equipment, and more particularly to a dual-shaft synchronous tightening device for bolts on the camshaft flange of a marine diesel engine. Background Technology

[0002] Bolts are common fasteners that play a vital role in various mechanical equipment and structures. Proper bolt tightening is essential for the safety, stability, and normal operation of equipment. The bolted connection of the camshaft flange of a marine diesel engine is a critical link in its power transmission chain, and its assembly quality directly affects the reliability and lifespan of the main engine. However, in the actual assembly process of this component, the following problems exist:

[0003] The operating space is extremely narrow: the camshaft is installed in a sealed camshaft housing, and the operator can only pass through a narrow opening on the side of the housing (such as...). Figure 1 (As shown) to perform the operation. This limited space makes it difficult for conventional automated tightening equipment to intervene, and also severely restricts the operator's arm movement and the range of tool swing.

[0004] The double-flange structure presents complex challenges: such as Figure 1 As shown, within a single camshaft housing, a cam flange and a round flange are respectively installed at both ends of the camshaft, both of which require bolt tightening. This not only doubles the workload, but also, because the structures of the two flanges and their clearances with adjacent cams are different, further increases the complexity and difficulty of designing a single device that can accommodate both structures.

[0005] Synchronous and symmetrical tightening is impossible: Existing processes mainly rely on operators using torque wrenches to tighten bolts one by one while rotating the camshaft. This method cannot achieve cross-tightening of bolts, which easily leads to uneven force on the flange surface and skewing, causing problems such as gasket seal failure and large dispersion of bolt preload, thus creating potential leaks and loosening hazards for long-term equipment operation.

[0006] The intermediate shaft structure presents unique challenges: the camshaft body is at the center of the camshaft flange, making it impossible to directly apply to most automated tightening devices designed for flat flanges (whose drive mechanisms are typically located at the center). Designing a tightening device that can bypass or grip the central shaft is the core challenge in achieving automation.

[0007] Low assembly efficiency: Due to the space and structural limitations mentioned above, operators need to tighten the bolts on the two flanges one after the other. The tightening process is cumbersome and slow, which has become a significant bottleneck on the marine diesel engine assembly line, seriously restricting the assembly efficiency and capacity improvement of the whole machine.

[0008] The operation is physically demanding and the working environment is harsh: operators need to apply high torque in an awkward posture for a long time, which not only consumes a lot of physical strength, but also easily leads to unstable tightening quality due to fatigue, and may even cause personal injury risks. Summary of the Invention

[0009] Purpose of the invention: The purpose of this invention is to provide a dual-shaft synchronous tightening device for camshaft flange bolts of marine diesel engines that can effectively cope with the narrow space of the camshaft box, the central shaft structure, the need to simultaneously handle the cam and the round flange and meet the requirements of high-quality synchronous tightening process.

[0010] Technical Solution: The dual-shaft synchronous tightening device for marine diesel engine camshaft flange bolts of the present invention includes a dual tightening mechanism that matches the flange to be tightened in the camshaft housing. The dual tightening mechanism includes two tightening fixtures that can engage with the camshaft in the camshaft housing, and the two tightening fixtures are spaced apart. Each tightening mechanism includes at least two tightening execution units symmetrically arranged along the camshaft. The dual tightening mechanism is provided with an adjustment mechanism for adjusting its height and controlling its rotation. The dual tightening mechanism and the flange to be tightened are provided with a positioning mechanism for confirming the initial position of the dual tightening mechanism.

[0011] By incorporating two tightening fixtures that engage with the camshaft, the problem of installation and positioning of the tightening mechanism in a center-shaft structure is first solved. Instead of passing through the flange center, the tightening fixtures engage with the shaft from the outside, thus bypassing the obstruction of the central shaft (camshaft). Each tightening fixture has at least two symmetrical tightening execution units along the axis, enabling the equipment to simultaneously apply torque to bolts at symmetrical positions on the same flange, achieving symmetrical and synchronous tightening and effectively avoiding panel misalignment and preload dispersion caused by manual tightening. The spacing between the two tightening fixtures corresponding to the two flanges also bypasses the annular protrusion in the middle of the camshaft. Combined with the adjustment mechanism, height adjustment and rotation control are achieved, allowing one set of equipment to collaboratively handle the tightening tasks of two flanges. The positioning mechanism ensures that the tightening execution units are accurately aligned with the bolt positions before each operation. In summary, this equipment can perform symmetrical tightening operations on double flanges with camshafts in confined spaces, eliminating the need for manual tightening, significantly improving assembly quality and efficiency, and reducing labor intensity.

[0012] Preferably, the adjustment mechanism includes an indexing mechanism and a support platform. The indexing mechanism is connected to two tightening fixtures of the double tightening mechanism and drives the two to rotate synchronously. The indexing mechanism is set on the support platform whose height can be adjusted.

[0013] By connecting the indexing mechanism to two tightening fixtures and driving them to rotate synchronously, precise coordination of the two tightening mechanisms in terms of rotation angle is achieved. This is crucial to ensuring that the bolts on the two flanges can be tightened synchronously in a predetermined sequence (such as the cross-rotation method). Setting the indexing mechanism on an adjustable-height support platform allows the entire actuator to flexibly adapt to the height position of different diesel engine camshaft models, enhancing the equipment's versatility and ease of operation.

[0014] Preferably, the tightening fixture includes a hinged fixture carrier and a drive unit for opening and closing the fixture carrier, and the tightening execution unit is disposed on the fixture carrier.

[0015] The device employs a hinged tooling carrier, with its opening and closing controlled by a drive unit, enabling rapid and reliable clamping and releasing of the camshaft. This simple and compact structure, with minimal space requirements for opening and closing, makes it particularly suitable for the confined operating space within the camshaft housing.

[0016] Preferably, the tooling carrier is provided with a V-shaped positioning block for contacting the camshaft surface, wherein at least one V-shaped positioning block is a height-adjustable structure so that the two tightening toolings are concentric with the camshaft when they engage with it.

[0017] By setting V-shaped positioning blocks on the tooling carrier, the radial positioning accuracy is ensured when the tightening tooling clamps the camshaft, enabling the tightening execution unit to be accurately centered. At least one of the V-shaped positioning blocks is height-adjustable. This design can effectively compensate for machining errors of the camshaft or slight diameter differences between different batches of camshafts, ensuring that the equipment remains concentric with the camshaft after each clamping, thereby ensuring the accurate transmission of tightening torque and the uniformity of bolt force.

[0018] Preferably, the tightening execution unit includes a bit that matches the flange to be tightened, as well as a rotation unit and a telescopic unit for controlling the rotation and extension of the bit. The telescopic unit is equipped with a sensing device for issuing a positioning signal when the bit reaches a set position.

[0019] The tightening unit integrates a bit, a rotating unit, and a telescopic unit, forming a complete automatic tightening module. The telescopic unit controls the axial movement of the bit, enabling dynamic engagement and disengagement with the bolt during rotation. The sensing device sends a signal when the bit reaches the set position, providing precise feedback to the control system and ensuring that torque output is only initiated after the bit is fully in place. This effectively avoids slippage or bolt head damage caused by poor engagement, improving the reliability and safety of the operation.

[0020] Preferably, the rotating unit is a hydraulic structure, and the rotating units of all tightening actuators on the same tightening fixture share the same oil circuit.

[0021] By configuring the rotating unit as a hydraulic structure, it can output high torque to meet the high preload requirements of marine diesel engine flange bolts. All tightening actuators on the same tightening fixture share the same oil circuit, which greatly simplifies the hydraulic pipeline layout, avoids interference problems caused by too many pipelines in a narrow space, and ensures the synchronization and consistency of torque output of multiple tightening units.

[0022] Preferably, the support platform is provided with a retainer for connecting the indexing mechanism, and the retainer is ball-hinged to the telescopic device of the support platform.

[0023] The cage is ball-jointed to the telescopic device of the support platform, while the indexing mechanism is connected to the cage, allowing the indexing mechanism to not only rise and fall, but also swing to more flexibly enter the camshaft box for operation.

[0024] Preferably, the positioning mechanism includes a positioning auxiliary fixture and an optical fiber sensor; the positioning auxiliary fixture is detachably connected to the flange to be tightened, and the positioning auxiliary fixture is provided with a positioning probe for detection by the optical fiber sensor; the optical fiber sensor is installed on the tightening fixture.

[0025] A precise initial angle positioning system is formed by combining a detachable positioning auxiliary fixture and a fiber optic sensor mounted on the tightening fixture. Before automated operation, the system can accurately identify the angular position of the first bolt to be tightened by detecting the probe on the auxiliary fixture through the sensor, providing a reliable starting reference for subsequent indexing and tightening in a preset sequence (such as the cross-clamp method).

[0026] Preferably, the positioning auxiliary fixture is provided with a V-shaped positioning groove for engaging with the bolt head on the flange to be tightened, and the positioning probe axis passes through the center of the bolt head being engaged; the positioning auxiliary fixture is also provided with a positioning side for the positioning probe to also pass through the center of the camshaft, and the positioning side abuts against the adjacent bolt head.

[0027] The specific design of the V-shaped positioning groove and positioning side on the positioning auxiliary tooling ensures that when it is installed on the flange, the axis of the positioning probe can accurately pass through the center of the bolt head and the center of the camshaft. This establishment of dual positioning references allows the probe position detected by the fiber optic sensor to uniquely and accurately correspond to the actual spatial position of the first bolt, significantly improving the accuracy and reliability of the initial positioning.

[0028] Preferably, the positioning auxiliary tooling is equipped with a magnetic mechanism for adsorbing onto the flange to be tightened.

[0029] A magnetic mechanism is installed on the positioning auxiliary fixture, allowing it to quickly and firmly attach to the flange (made of steel) to be tightened. This detachable connection method ensures the stability of the positioning fixture during equipment entry and hole finding, and also allows for quick removal after the operation is completed without affecting subsequent processes, thus improving operational convenience.

[0030] Beneficial effects: By employing a double tightening mechanism that can engage with the central shaft, a tightening execution unit arranged symmetrically along the axis, and a precise adjustment and positioning mechanism, this invention effectively solves the problem of automated synchronous tightening of camshaft flange bolts for marine diesel engines in narrow spaces and under central shaft conditions, thus achieving high-quality and high-efficiency assembly operations. Attached Figure Description

[0031] Figure 1 A schematic diagram of the marine diesel engine camshaft box, which is the application object of this invention;

[0032] Figure 2 This is a schematic diagram of the overall assembly structure of this equipment;

[0033] Figure 3 This is a schematic diagram of the working status of this equipment;

[0034] Figure 4 Schematic diagram on the right side of the tooling for tightening bolts on the cam flange;

[0035] Figure 5 Schematic diagram of the left side of the tooling for tightening the cam flange bolts;

[0036] Figure 6 This is a schematic diagram of the adjustable V-shaped positioning block structure;

[0037] Figure 7 This is a schematic diagram of the tightening actuator structure;

[0038] Figure 8 This is a schematic diagram of the clamping drive unit structure;

[0039] Figure 9 A schematic diagram of the left side of the tooling for tightening bolts on a round flange;

[0040] Figure 10 Schematic diagram on the right side of the tooling for tightening round flange bolts;

[0041] Figure 11 This is a schematic diagram of the right side of the indexing mechanism;

[0042] Figure 12 This is a schematic diagram of the left side of the indexing mechanism;

[0043] Figure 13 This is a schematic diagram of the structure connecting the double tightening mechanism to the indexing mechanism;

[0044] Figure 14 A schematic diagram of the supporting platform;

[0045] Figure 15 This is a schematic diagram of the positioning auxiliary tooling structure in the positioning mechanism. Detailed Implementation

[0046] See Figure 1 and Figure 3 As shown, the application scenario of this device is a marine diesel engine camshaft housing 1, which has a rectangular opening on its side (camshaft housing opening 1-5). The device of this invention enters the camshaft housing through this opening. The camshaft 1-1 penetrates the housing. There is a cam flange 1-2 on its right side and a round flange 1-3 on its left side. The bolt holes on the two flanges are symmetrically distributed. There is a cam 1-4 in the middle of the camshaft 1-1, and the distance from the right side of the cam 1-4 to the cam flange is less than the distance from the left side of the cam to the round flange. It should be noted that in this specific embodiment, the directional terms such as "left," "right," and "side" are all based on... Figure 1 The perspective shown.

[0047] like Figure 2 As shown, the assembly structure of the dual-axis synchronous tightening device for marine diesel engine camshaft flange bolts of the present invention mainly consists of the following parts: dual tightening mechanism 2, indexing mechanism 3, support platform 4, and positioning mechanism.

[0048] The double tightening mechanism 2 includes: a cam flange bolt tightening fixture 2-1 corresponding to the cam flange positions 1-2, and a round flange bolt tightening fixture 2-2 corresponding to the round flange positions 1-3. The two mechanisms have similar main structures and both adopt a hinge-type opening and closing design, but have been adapted to the different spatial constraints on both sides.

[0049] See Figures 4-5 The cam flange bolt tightening fixture 2-1 includes a first fixed fixture carrier 2-1-1, a first tightening execution unit 2-1-2, a first clamping drive unit 2-1-3, a first movable fixture carrier 2-1-4, a second tightening execution unit 2-1-5, a first fixed V-shaped positioning block 2-1-6, a first adjustable V-shaped positioning block 2-1-7, a rotary joint 2-1-8, and a hydraulic circuit 2-1-9. To achieve symmetrical tightening, the first tightening execution unit 2-1-2 and the second tightening execution unit 2-1-5 are symmetrically arranged about the camshaft 1-1. The first fixed V-shaped positioning block 2-1-6 and the first adjustable V-shaped positioning block 2-1-7 are symmetrically arranged about the camshaft for radial positioning.

[0050] See Figure 6The first adjustable V-shaped positioning block 2-1-7 includes a V-shaped block body 2-1-71, a fine-pitch adjusting screw 2-1-72, and a wedge-shaped adjusting block 2-1-73. The fine-pitch adjusting screw 2-1-72 passes through the V-shaped block body 2-1-71 and the wedge-shaped adjusting block 2-1-73. The wedge-shaped adjusting block 2-1-73 has an elongated through hole, allowing the fine-pitch adjusting screw 2-1-72 to slide up and down. The V-shaped block body 2-1-71 is slidably connected within the first movable tooling carrier 2-1-4 (allowing it to slide up and down). By adjusting the fine-pitch adjusting screw 2-1-72, the wedge-shaped adjusting block 2-1-73 is pushed to slide, thereby achieving V-shaped vertical height adjustment. This adjustment is a preliminary calibration operation for the equipment. After completing one calibration for the camshaft of the same model of marine diesel engine, the position is locked and kept fixed during operation to ensure that the tightening mechanism is concentric with the camshaft when it grips the camshaft. Hydraulic circuit 2-1-9 is arranged within the annular groove on the outer wall of the workpiece. The hollow hydraulic wrenches in the two tightening actuators share one inlet and one return oil circuit, while the hollow hydraulic wrench used for clamping has its own separate inlet and return oil circuit. To avoid interference between the oil circuit and the camshaft box when the tightening mechanism rotates the positioning bolt, the direction is changed and the bending radius of the oil circuit is reduced by installing the rotary joint 2-1-8, which is located in the outer space of the middle cam 1-4.

[0051] See Figure 7 Taking the second tightening actuator 2-1-5 as an example, its structure includes: a hollow hydraulic wrench 2-1-51, a hexagonal bit 2-1-52, an electromagnetic spring 2-1-53, and a micro switch 2-1-54. The hollow hydraulic wrench 2-1-51 serves as a rotational power source, with a hollow output end that allows the hexagonal bit to pass through and transmit torque. In this embodiment, the hydraulic wrench is a small-sized, thin structure customized for the camshaft box space. Its oil inlet and outlet are connected via a hydraulic oil circuit 2-1-9 arranged in the annular groove on the outer wall of the workpiece. The hexagonal bit, as the final torque actuator, is made of high-strength alloy steel. Its large end is the first-stage bit, which engages with the output end of the hydraulic wrench via an axial sliding pair (the sliding pair restricts the axial displacement of the hexagonal bit, preventing slippage), allowing it to move axially. Its small end is the second-stage bit, directly acting on the bolt head, and its top end is provided with a guide slope to facilitate automatic sliding into the hexagonal hole of the bolt during rotation. The electromagnetic spring acts as a linear actuator, with its cylinder fixed to the tooling carrier and its push rod connected to the tail of the hexagonal screwdriver bit. When energized, the electromagnetic spring extends, pushing the bit forward; when de-energized, it retracts due to internal spring force. A microswitch is mounted on the electromagnetic spring push rod. When the hexagonal screwdriver bit is fully extended to its working position, the electromagnetic spring cylinder triggers the switch, sending a "bit in position" signal to the control system. This signal stops the electromagnetic spring from pushing the hexagonal screwdriver bit. During the tightening process, the intelligent hydraulic pump station senses the torque in real time and de-energizes the electromagnetic spring when the torque reaches a set value, causing the hexagonal screwdriver bit to retract.

[0052] See Figure 8 The first clamping drive unit 2-1-3 comprises a rotating hollow hydraulic wrench 2-1-31, a hexagonal drive shaft 2-1-32, a retaining ring 2-1-33, and a fixing screw 2-1-34. The rotating hollow hydraulic wrench is also a thin structure customized for space, mounted on the first fixed tooling carrier 2-1-1. Its output end is fitted with the hexagonal drive shaft, which engages with a hexagonal hole on the movable tooling carrier 2-1-4. When the hollow hydraulic wrench is driven to rotate, the hexagonal drive shaft can drive the movable tooling carrier to rotate, realizing the opening and closing action of the two halves of the tooling body, thereby clamping or releasing the camshaft 1-1. The retaining ring is a cylindrical structure with an internal opening that engages with the hexagonal drive shaft. It is mounted on the hexagonal drive shaft to limit the axial floating of the movable tooling carrier during the opening and closing process. The fixing screw is mounted on the retaining ring, simultaneously fixing the retaining ring and the hexagonal drive shaft to prevent detachment.

[0053] See Figures 9-10The main structure of the circular flange bolt tightening fixture 2-2 is the same as that of the cam flange bolt tightening fixture 2-1. Both adopt a hinge-type fixture carrier design and include components such as a third tightening execution unit 2-2-1, a second fixed fixture carrier 2-2-2, a fourth tightening execution unit 2-2-3, a second movable fixture carrier 2-2-4, a second clamping drive unit 2-2-5, a rotary joint 2-2-6, and a hydraulic circuit 2-2-7. The tightening execution unit and clamping drive unit of this mechanism are exactly the same as those on the cam flange side. However, since the circular flange 1-3 is located on the left side of the camshaft, its axial distance from the intermediate cam 1-4 is smaller, and the operating space is narrower. Therefore, this mechanism has been adapted in the following aspects: the axial thickness of the second fixed fixture carrier 2-2-2 and the second movable fixture carrier 2-2-4 is smaller than that of the corresponding components on the cam flange side. This thinning design allows the entire mechanism to smoothly enter the narrow gap between the round flange and the side wall of the cam box, while maintaining sufficient structural strength to withstand the tightening torque. To avoid the space occupied by the intermediate cam and indexing mechanism, and considering the thinned tooling carrier design, the rotary joint 2-2-6 and hydraulic oil circuit 2-2-7 of this mechanism are uniformly arranged on the left side of the tooling body (i.e., outside the round flange). The hydraulic oil circuit 2-1-9 of the tooling for tightening the cam flange bolts then converges into the intelligent hydraulic pump station 5. A section of arc-shaped open guide rail 2-2-8 is bolted to the right side of the second fixed tooling carrier 2-2-2. The cross-section of this guide rail is I-shaped, its arc is concentric with the camshaft, and its arc length covers the entire rotation angle range required for all bolt tightening positions. The guide rail is made of aluminum alloy, increasing strength while reducing weight. The arc-shaped open guide rail has a gap with the second movable tooling carrier, facilitating the mechanism's gripping of the camshaft. The function of this guide rail is to cooperate with the auxiliary guide wheel on the indexing mechanism to provide additional support and traction for the round flange bolt tightening fixture, ensuring its stability during rotation and synchronization with the cam flange side. Since this structure is not required on the cam flange side, it is only installed on the round flange side.

[0054] See Figures 11-13The indexing mechanism 3 is the core transmission and control component of this invention, used to drive the double tightening mechanism 2 to rotate synchronously and accurately around the camshaft axis. It includes an integrated joint module 3-1, a gearbox 3-2, a support plate 3-3, an integrated connector 3-4, a first roller 3-5, an integrated guide rail with an external meshing open gear ring 3-6, a double-ended screw 3-7, and a second roller 3-8. The integrated guide rail with an external meshing open gear ring 3-6 is the core transmission and load-bearing component. This component integrates the functions of a transmission gear ring and a guide rail. Its right side is bolted to the first fixed fixture carrier 2-1-1 of the cam flange tightening mechanism via the integrated connector 3-4, thus pulling the cam flange tightening mechanism; its left side is connected to the second fixed fixture carrier 2-2-2 of the round flange tightening mechanism via the double-ended screw 3-7, thereby achieving synchronous drive. The support plate 3-3 is a fixed component, installed at the front end of the retainer 4-1 of the support platform 4. Its five first rollers 3-5 on the right side cooperate with the guide rail portion of the integrated external meshing open gear ring guide rail 3-6, constraining it to retain only rotational freedom, ensuring the rotation angle covers ±90°. The four second rollers 3-8 (auxiliary guide wheels) on the left side of the support plate 3-3 cooperate with the arc-shaped open guide rail 2-2-8 on the round flange tightening mechanism, providing guidance and traction. Power is provided by the integrated joint module 3-1, which is fixedly installed on the side of the support plate and integrates a servo motor, harmonic reducer, and high-precision encoder. The output shaft of this module transmits power through two pairs of external meshing cylindrical gears in the gearbox 3-2, ultimately driving the integrated external meshing open gear ring guide rail 3-6 to rotate. Precise positioning of the rotation angle can be achieved through closed-loop control of the encoder.

[0055] See Figure 2 , Figure 14The support platform 4 serves as the foundation for the entire equipment, providing lifting, balancing, and adaptive adjustment functions for the front-end actuator. It includes: a cage 4-1, a ball joint 4-2, a counterweight 4-3, a lifting electric cylinder 4-4, a movable trolley 4-5, and an intelligent hydraulic pump station 5. The cage 4-1 is a frame structure, with its front end bolted to the support plate 3-3 of the indexing mechanism 3, and its rear end connected to the ball joint 4-2. The ball joint 4-2 has multi-directional follow-up capability, allowing the actuator to adaptively deflect within a small range to compensate for alignment errors and eliminate the opposing internal forces that may arise from rigid connections. A lower limit block and left and right limit blocks are provided on the outside of the ball joint to prevent the front-end mechanism from sagging due to gravity when the equipment is not clamped to the camshaft. A combined counterweight 4-3 is installed behind the ball joint. The ball joint is fixed to the top of the lifting electric cylinder 4-4, which has a built-in servo motor and ball screw mechanism. The control system can precisely adjust the working height of the equipment to align the double tightening mechanism with the camshaft box opening. During the tightening operation, the electric cylinder remains locked in position, providing stable support. The lifting electric cylinder is mounted on the movable trolley 4-5. The movable trolley has a box-type structure, with an intelligent hydraulic pump station 5 installed in its internal cavity, providing power to all hydraulic wrenches. For ease of operation, the control and display functions of the pump station are connected to the intelligent touch screen display on the upper surface of the trolley via wiring. The trolley is equipped with casters at its four corners with brakes, allowing for free movement and flexible deployment on site. Once it reaches the working position, the trolley can be fixed in place by braking.

[0056] See Figure 4 , Figure 15The positioning mechanism includes a positioning auxiliary fixture 6 and a fiber optic sensor 7. The positioning auxiliary fixture includes a positioning probe 6-1, a positioning side 6-2, a positioning base 6-3, and a fiber optic baffle 6-4. The positioning base 6-3 has a V-shaped positioning groove on its bottom surface for engaging with a selected bolt head on the cam flange 1-2, ensuring the axis of the positioning probe 6-1 passes through the center of the bolt head. The positioning side 6-2 is located on one side of the positioning base 6-3 for engaging with adjacent bolts, allowing the axis of the positioning probe 6-1 to pass through the center of the camshaft 1-1. Magnetic patches 6-5 are installed on the back and sides of the positioning base for fixing it to the cam flange. The positioning probe 6-1 is a slender rod, vertically fixed to the positioning base, extending upwards to the outside of the cam flange, with a tapered tip for easy identification by the fiber optic sensor. The fiber optic baffle 6-4 is fixed to the positioning base with screws. When the fiber optic sensor 7 detects the fiber optic baffle 6-4, it sends a corresponding signal to the control system to slow down the servo motor speed in the integrated joint module 3-1, preventing the tightening mechanism from rotating too fast and missing the positioning probe 6-1. The fiber optic sensor 7 is a diffuse reflection fiber optic sensor, installed on the right side of the cam flange bolt tightening fixture 2-1 (i.e., the side closer to the cam flange). This sensor includes a fiber optic head and an amplifier. When the indexing mechanism drives the tightening mechanism to rotate, the fiber optic sensor indirectly identifies the precise angle of the first bolt to be tightened by detecting the position of the positioning probe, providing a starting reference for subsequent orderly tightening.

[0057] The working process of this equipment can be briefly described as follows:

[0058] S1, Initial positioning: Select a bolt on the cam flange that is close to the opening of the camshaft box as a reference, and magnetically attach the positioning auxiliary tooling to the bolt position; push the movable trolley to the front of the camshaft box opening, adjust the height of the lifting electric cylinder, so that the central axis of the double tightening mechanism is initially aligned with the camshaft axis.

[0059] S2, Entry and Clamping: Slowly push the front end of the equipment into the camshaft box, finely adjust the radial position through the movable trolley casters, and finely adjust the height through the lifting electric cylinder, so that the left side of the cam flange bolt tightening fixture fits with the right side of the cam, and determine the axial position; synchronously control the clamping drive unit of the double tightening mechanism to drive the hinged fixture carrier to close and clamp the camshaft.

[0060] S3, Hole Finding and Tightening: The indexing mechanism drives the double tightening mechanism to rotate. When the fiber optic sensor detects the positioning probe on the positioning auxiliary tooling, it determines the position of the first bolt. When the rotation approaches the target angle, the hollow hydraulic wrench of the tightening execution unit slows down the rotation speed. At the same time, the electromagnetic spring drives the hexagonal bit to extend, so that the bit enters the inner hexagon of the bolt during rotation. After the micro switch provides feedback on the position signal, the intelligent hydraulic pump station applies force according to the predetermined torque to complete the synchronous tightening of the first pair of bolts.

[0061] S4, Sequential Operation: The indexing mechanism rotates to the next target angle according to the cross method. When it is near the target angle, it decelerates and repeats the above process of finding holes, connecting bits, and tightening torque until all bolts in symmetrical positions are tightened.

[0062] S5, Equipment Separation: After all bolts are tightened, the indexing mechanism rotates back to the initial entry angle, and the clamping drive unit of the double tightening mechanism reverses its action to release the camshaft; slowly pull the movable trolley backward so that the entire equipment exits from the camshaft box opening, completing the tightening operation.

Claims

1. A dual-shaft synchronous tightening device for camshaft flange bolts of marine diesel engines, characterized in that: Includes a double tightening mechanism (2) that matches the flange to be tightened in the camshaft housing (1). The double tightening mechanism (2) includes two tightening fixtures that can engage with the camshaft (1-1) in the camshaft housing (1), and the two tightening fixtures are spaced apart. Each tightening mechanism includes at least two tightening execution units that are symmetrically arranged along the camshaft (1-1). The double tightening mechanism (2) is provided with an adjustment mechanism for adjusting its height and controlling its rotation. The double tightening mechanism (2) and the flange to be tightened are provided with a positioning mechanism for confirming the initial position of the double tightening mechanism (2).

2. The device according to claim 1, characterized in that: The adjustment mechanism includes an indexing mechanism (3) and a support platform (4). The indexing mechanism (3) is connected to two tightening fixtures of the double tightening mechanism (2) and drives the two to rotate synchronously. The indexing mechanism (3) is set on the support platform (4) whose height can be adjusted.

3. The device according to claim 1, characterized in that: The tightening fixture includes a hinged fixture carrier and a drive unit that drives the opening and closing of the fixture carrier. The tightening execution unit is mounted on the fixture carrier.

4. The device according to claim 3, characterized in that: The tooling carrier is provided with a V-shaped positioning block for contacting the surface of the camshaft (1-1), wherein at least one V-shaped positioning block is a height-adjustable structure so that the two tightening toolings are concentric with the camshaft (1-1) when they engage with the camshaft (1-1).

5. The device according to claim 1, characterized in that: The tightening execution unit includes a bit that matches the flange to be tightened, as well as a rotation unit and a telescopic unit that control the rotation and extension of the bit. The telescopic unit is equipped with a sensing device for issuing a positioning signal when the bit reaches a set position.

6. The device according to claim 5, characterized in that: The rotating unit is a hydraulic structure, and all rotating units of the tightening actuators on the same tightening fixture share the same oil circuit.

7. The device according to claim 2, characterized in that: The support platform (4) is provided with a retainer (4-1) for connecting the indexing mechanism (3), and the retainer (4-1) is ball-hinged to the telescopic device of the support platform (4).

8. The device according to claim 1, characterized in that: The positioning mechanism includes a positioning auxiliary fixture (6) and an optical fiber sensor (7); the positioning auxiliary fixture (6) is detachably connected to the flange to be tightened, and the positioning auxiliary fixture (6) is provided with a positioning probe (6-1) for detection by the optical fiber sensor (7); the optical fiber sensor (7) is installed on the tightening fixture.

9. The device according to claim 8, characterized in that: The positioning auxiliary tool (6) is provided with a V-shaped positioning groove for engaging with the bolt head on the flange to be tightened, and the axis of the positioning probe (6-1) passes through the center of the bolt head being engaged; the positioning auxiliary tool (6) is also provided with a positioning side (6-2) for engaging the positioning probe (6-1) through the center of the camshaft (1-1), and the positioning side (6-2) abuts against the adjacent bolt head.

10. The device according to claim 9, characterized in that: The positioning auxiliary tooling (6) is equipped with a magnetic mechanism for adsorbing onto the flange to be tightened.

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