Crank shrinkage fit heating device

Abstract

The utility model relates to a crank shrinkage fit heating device which comprises an electromagnetic induction heater, the electromagnetic induction heater comprises a shell, an electromagnetic induction coil arranged in the shell and a magnetizer fixed on the electromagnetic induction coil, and the shell comprises a front end plate and a rear end plate which are shaped like a Chinese character'hui '. The outer pipe is connected between the front end plate and the rear end plate, the inner pipe is located in the outer pipe, and a tubular cavity is defined by the front end plate, the rear end plate, the inner pipe and the outer pipe. The electromagnetic induction coil and the magnetizer are arranged around the inner pipe, and an insulating layer is arranged between the electromagnetic induction coil and the magnetizer and the inner pipe; a cavity matched with a crank arm of the crank in shape is formed in the inner pipe; an air inlet and an air outlet are formed in the two sides of the outer pipe respectively, and a power connector connected with the electromagnetic induction coil is further arranged on the outer pipe. The heating device has the advantages that the full-surrounding square-tube-shaped electromagnetic induction heater is arranged, the crank arm except a crank pin is placed in the electromagnetic induction heater, the whole crank arm is heated, the heating uniformity is higher, the whole deformation of the crank is uniform, and the shrinkage fit machining quality is greatly improved.

Description

Technical Field

[0001] This utility model relates to the field of crank sleeve processing technology, and in particular to a crank sleeve heating device. Background Technology

[0002] The crankshaft is the most important component in an engine. The engine drives the connecting rods in a reciprocating motion via the pistons, and this motion is converted into torque output by the crankshaft through the crankshaft. In large, low-speed marine diesel engines, the crankshaft, due to its enormous overall mass, often employs a semi-assembled structure. The main journal and crankshaft are joined together using a "red-sleeve" process. This "red-sleeve" process involves heating the crankshaft to a certain temperature to enlarge the bore, then fitting the room-temperature main journal into the bore. After cooling, the interference fit between the main journal and the crankshaft bore creates a clamping force, making it a unit capable of withstanding the required load.

[0003] During the machining of crankshaft bushings, bonding strength is primarily determined by interference fit and temperature. Minimum interference fit is controlled to prevent loosening and slippage at the mating joints, while maximum interference fit is controlled to prevent material damage and deformation at the mating joints. Uniform temperature distribution on the crank bore inner wall is maintained to ensure the roundness of the mating joints and the overall quality of the bushing machining. The interference fit can be calculated using empirical formulas during the machining process. Achieving a uniformly distributed temperature on the crank bore inner wall to control irregular deformation becomes a key issue in improving the quality of crankshaft bushings.

[0004] In the crankshaft bushing process, traditional heating methods often use natural gas as an energy source. This not only causes carbon buildup and severe oxidation on the heated surfaces, but also results in long heating cycles and uneven temperature distribution, making it difficult to precisely control the deformation of the workpiece. Currently, the industry standard heating method is electromagnetic induction heating.

[0005] Existing crankshaft electromagnetic induction heating systems mainly consist of a ring-shaped crank arm coil and a circular crank bore coil. The circular crank bore coil is inserted into the crank bore of the crankshaft to heat the area around the bore. The crank arm coil is positioned around the crank arm between the crank arm bore and the crank pin to heat the crank arm between these two points. This arrangement is problematic because the area around the crank bore is asymmetrical. Using a single circular coil inside the crank bore for induction heating would create an uneven temperature field and thermal deformation in the vicinity of the bore, ultimately failing to guarantee the required heat transfer quality. The aforementioned solution compensates for this by using a ring-shaped crank arm coil to heat the area between the crank arm bore and the crank pin, thereby improving the uniformity of heating around the crank bore.

[0006] However, it is clear that this combined heating scheme still makes it difficult to ensure the uniformity of heating around the crank bore, resulting in uneven crank deformation and affecting the quality of the crank sleeve machining.

[0007] Therefore, it is necessary to improve and optimize the existing red-covering equipment so that it can better meet user needs. Utility Model Content

[0008] The purpose of this utility model embodiment is to address the shortcomings of the existing technology structure by proposing a crankshaft heating device to solve the defects in the existing technology.

[0009] To achieve the aforementioned utility model objectives, the crankshaft heating device proposed in this utility model embodiment is implemented through the following technical solution:

[0010] A crankshaft arm heating device includes an electromagnetic induction heater. The electromagnetic induction heater includes a housing, an electromagnetic induction coil disposed within the housing, and a magnetic conductor fixed on the electromagnetic induction coil. The housing comprises U-shaped front and rear end plates, an outer tube connected between the front and rear end plates, and an inner tube located within the outer tube. The front and rear end plates, the inner tube, and the outer tube form a tubular cavity. The electromagnetic induction coil and the magnetic conductor are arranged around the inner tube and an insulating layer is provided between them. A cavity matching the shape of the crankshaft arm is formed within the inner tube. An air inlet and an air outlet are respectively provided on both sides of the outer tube, and a power connector for connecting the electromagnetic induction coil is also provided on the outer tube.

[0011] The tubular cavity is also equipped with several coil temperature sensors for measuring the temperature of the electromagnetic induction coil, and the outer tube is provided with a signal line interface for connecting the coil temperature sensors.

[0012] The inner tube is also equipped with a workpiece temperature sensor for measuring the temperature around the crank arm crank hole inside the inner tube, and the outer tube is equipped with a signal line interface for connecting the workpiece temperature sensor.

[0013] The crank sleeve heating device also includes an air-cooling component, which is connected to the air inlet via an air pipe.

[0014] The crank sleeve heating device also includes a controller, which controls the connection to the air-cooling assembly and can control the connection to the signal line interface and power connector via cables.

[0015] The crank sleeve heating device includes several electromagnetic induction heaters, and also includes a hoisting mechanism and a cabinet. The cabinet is provided with several placement positions for placing electromagnetic induction heaters. The hoisting mechanism has grippers that match the shape of the electromagnetic induction heaters and can hoist the electromagnetic induction heaters in the placement positions to workstations near the cabinet.

[0016] Compared with existing technologies, the beneficial effects of this utility model are:

[0017] 1. A fully enclosed U-shaped tubular electromagnetic induction heater is installed. By placing the crank arm (excluding the crank pin) inside the electromagnetic induction heater, the entire crank arm is heated. This results in higher heating uniformity, significantly improved uniformity of crank heating, and more consistent overall deformation, greatly improving the quality of the crank sleeve processing.

[0018] 2. The air-cooled structure completely eliminates faults from the water system and uses a temperature sensor to monitor the coil temperature in real time to adjust the blower airflow, thus ensuring coil safety.

[0019] 3. By monitoring the workpiece temperature in real time through a temperature sensor, the alternating current frequency is automatically controlled, thereby improving the uniformity of the overall heating of the crank arm. Attached Figure Description

[0020] The above features and advantages of the present invention will become clearer and easier to understand from the following description of exemplary embodiments thereof in conjunction with the accompanying drawings.

[0021] Figure 1 This is a schematic diagram (I) of the overall structure of the crank sleeve heating device according to an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram (II) of the overall structure of the crank sleeve heating device according to an embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram (I) of the electromagnetic induction heater according to an embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram (II) of the electromagnetic induction heater according to an embodiment of the present invention;

[0025] Figure 5 This is a schematic diagram of the internal structure of the electromagnetic induction heater according to an embodiment of the present invention. Detailed Implementation

[0026] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0027] The terms "front," "rear," "left," "right," "inner," and "outer" used in this specification are merely for clarity of description and are not intended to limit the scope of implementation of this utility model. Any changes or adjustments to their relative relationships, without substantially altering the technical content, shall also be considered within the scope of implementation of this utility model.

[0028] In the description of the following embodiments, unless otherwise expressly specified and limited, the term "connection" and other such terms should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an indirect connection through an intermediate medium; it can be the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0029] See Figure 1-5 As shown in the figure, this utility model embodiment proposes a crankshaft heating device, which includes a cabinet 1, a hoisting mechanism 2 and several electromagnetic induction heaters 3.

[0030] The housing of the electromagnetic induction heater 3 includes a U-shaped front end plate 31, a rear end plate 32, an outer tube 33, and an inner tube 34.

[0031] The outer tube 33 is fitted outside the inner tube 34 and forms a gap with the inner tube 34. The outer tube 33 and the inner tube 34 are respectively connected between the front end plate 31 and the rear end plate 32, thereby forming a tubular cavity between the front end plate 31, the rear end plate 32, the outer tube 33 and the inner tube 34.

[0032] An electromagnetic induction coil and a magnetic conductor 35 fixed to the electromagnetic induction coil are disposed within this cavity. The electromagnetic induction coil and the magnetic conductor 35 are arranged around the inner tube 34, and an insulating and heat-insulating layer 36 is provided between them. In this embodiment, the insulating and heat-insulating layer 36 is made of clay insulation cotton. Since the mechanism of the electromagnetic induction coil is a common technology in the industry, it is only briefly shown in the figure, and its structure will not be described in detail. Any electromagnetic induction coil structure that can heat a metal crank workpiece can be applied here.

[0033] In addition, the tubular cavity is equipped with several coil temperature sensors for measuring the temperature of the electromagnetic induction coil. The inner tube 34 is also equipped with a workpiece temperature sensor 341 for measuring the temperature around the crank arm crank hole inside the inner tube.

[0034] The inner tube 34 forms a cavity that matches the shape of the crank arm of the crank 5.

[0035] An air inlet 331 is provided on one side of the outer tube 33, and several exhaust outlets 332 are evenly distributed on the opposite side to form a forced convection air duct. The outer tube 33 is provided with a power connector 333 for connecting to the electromagnetic induction coil, a signal line interface 334 for connecting to the coil temperature sensor, and a signal line interface 335 for connecting to the workpiece temperature sensor.

[0036] In addition, the crank sleeve heating device also includes an air-cooling component and a controller 4. The air-cooling component is a blower connected to the air inlet 331 via an air pipe. The controller 4 controls the air-cooling component and can control the signal line interface 334 and the power connector 333 via cables. Based on the feedback signals from the coil temperature sensor and the workpiece temperature sensor, it adjusts the airflow of the air-cooling component and the alternating current frequency of the electromagnetic induction coil in real time.

[0037] The cabinet 1 is provided with several placement slots 11 for placing electromagnetic induction heaters, which are used to store electromagnetic induction heaters.

[0038] The lifting mechanism 2 has grippers 21 that fit the shape of the electromagnetic induction heater, enabling it to lift the electromagnetic induction heater 3 from the cabinet 1 to a workstation near the cabinet 1. In this embodiment, the lifting mechanism 2 uses a balanced folding lifter. However, those skilled in the art will understand that the weight of the electromagnetic induction heater mainly consists of the weight of the shell, coil, and magnetic conductor, and more specifically, it depends on the workpiece size and heating process. The shell can also be deformed or fitted with accessories to suit the lifting process. Therefore, the choice of lifting mechanism is not limited to this; any equipment capable of stably lifting the electromagnetic induction heater can be used.

[0039] Compared with existing technologies, the beneficial effects of this utility model are:

[0040] 1. A fully enclosed square tubular electromagnetic induction heater is installed. By placing the crank arm (excluding the crank pin) inside the electromagnetic induction heater, the entire crank arm is heated. This results in higher heating uniformity and more uniform overall crank deformation, greatly improving the processing quality of the crank sleeve.

[0041] 2. It adopts a pure air-cooled heat dissipation design, which completely avoids the risk of leakage, scaling and other failures that may exist in traditional water-cooling systems. It also uses a temperature sensor to monitor the coil temperature in real time to adjust the blower airflow, thereby ensuring the safety of the coil.

[0042] 3. The temperature of the workpiece is monitored in real time by a temperature sensor, and the frequency of the alternating current is automatically controlled to improve the uniformity of the overall heating of the crank arm.

[0043] The present invention has been described in detail above through embodiments. However, those skilled in the art will understand that the above embodiments are only one of the preferred embodiments of the present invention. Due to space limitations, not all embodiments can be listed here. Any implementation that can embody the technical solution of the claims of the present invention is within the protection scope of the present invention.

[0044] It should be noted that the above content is a further detailed description of the present utility model in conjunction with specific embodiments, and it should not be considered that the specific embodiments of the present utility model are limited to this. Under the guidance of the above embodiments, those skilled in the art can make various improvements and modifications based on the above embodiments, and these improvements or modifications fall within the protection scope of the present utility model.

Claims

1. A crankshaft heating device, comprising an electromagnetic induction heater, wherein the electromagnetic induction heater comprises a housing, an electromagnetic induction coil disposed within the housing, and a magnetic conductor fixed on the electromagnetic induction coil, characterized in that: The housing includes U-shaped front and rear end plates, an outer tube connected between the front and rear end plates, and an inner tube located inside the outer tube. The front and rear end plates, the inner tube, and the outer tube together form an annular tubular cavity. The electromagnetic induction coil and the magnetic conductor are arranged around the inner tube and an insulating and heat-insulating layer is provided between them. A cavity matching the shape of the crankshaft and crank arm is formed inside the inner tube. An air inlet and an air outlet are respectively provided on both sides of the outer tube, and a power connector for connecting the electromagnetic induction coil is also provided on the outer tube.

2. The crank sleeve heating device according to claim 1, characterized in that: The tubular cavity is also equipped with several coil temperature sensors for measuring the temperature of the electromagnetic induction coil, and the outer tube is provided with a signal line interface for connecting the coil temperature sensors.

3. The crankshaft heating device according to claim 2, characterized in that: The inner tube is also equipped with a workpiece temperature sensor for measuring the temperature around the crank arm crank hole inside the inner tube, and the outer tube is equipped with a signal line interface for connecting the workpiece temperature sensor.

4. The crank sleeve heating device according to claim 3, characterized in that: The crank sleeve heating device also includes an air-cooling component, which is connected to the air inlet via an air pipe.

5. The crank sleeve heating device according to claim 4, characterized in that: The crank sleeve heating device also includes a controller, which controls the connection to the air-cooling assembly and can control the connection to the signal line interface and power connector via cables.

6. The crankshaft heating device according to claim 5, characterized in that: The crankshaft heating device includes multiple electromagnetic induction heaters, and also includes a hoisting mechanism and a cabinet. The cabinet is provided with several placement positions for placing electromagnetic induction heaters. The hoisting mechanism has grippers that match the shape of the electromagnetic induction heaters and can hoist the electromagnetic induction heaters in the placement positions to workstations near the cabinet.

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