A follow-up eccentric tool for crankshaft grinding

Abstract

The utility model discloses a follow eccentric tool for crankshaft grinding processing belongs to crankshaft processing frock technical field, including split type follow eccentric frame and ring support seat mechanism, split type follow eccentric frame sets up on ring support seat mechanism, split type follow eccentric frame includes follow ring, axle diameter support mechanism, axle diameter support mechanism is connected on follow ring, and follow ring sits on ring support seat mechanism, and axle diameter support mechanism is used for clamping and supporting crankshaft work piece, ring support seat mechanism is connected with machine tool guide rail cooperation, and ring support seat mechanism can reciprocatingly move along guide rail under machine tool power drive, follow ring includes ring body, web, and web is connected in ring body inside, and the middle part of web is hollow area, axle diameter support mechanism includes pressing plate, support base, and the connection of bolt and clearance adjusting spacer piece group is arranged between pressing plate and support base. The utility model discloses through the cooperation of pressing plate, support base, follow ring, has realized the quick clamping and dismounting of crankshaft axle diameter, and the operation is convenient, and the structure is compact.

Description

Technical Field

[0001] This utility model belongs to the field of crankshaft machining tooling technology, specifically relating to a follower eccentric tooling for crankshaft grinding. Background Technology

[0002] In reciprocating compressors used in large-scale chemical, petroleum, and natural gas industries, compressors with large eccentric crankshafts are often employed to meet the demands of high displacement and high pressure applications. By increasing the eccentricity, the piston stroke and working volume are increased, thereby improving the compressor's output power and compression efficiency. These compressors have a wide range of applications, commonly used in natural gas pipeline transportation and gas compression in large-scale chemical production.

[0003] However, the machining characteristics of a crankshaft are determined by its structural features. Due to the eccentricity between the crankpin and the main journal axis, the crankshaft's stiffness is significantly reduced. During the grinding of crankshaft bends, the eccentricity generates centrifugal force during rotation, causing bending of the workpiece's axis of rotation. This results in uneven cutting depths in the radial direction, severely affecting the accuracy of the bend's geometry. In the final machining result, the cylindricity of the bend is difficult to guarantee, especially for crankshafts with large eccentricities, where the relatively lower rigidity exacerbates the impact on machining accuracy.

[0004] To prevent bending deformation of the workpiece due to radial cutting forces and its own poor rigidity, conventional methods typically use a center rest as an auxiliary support to increase workpiece rigidity. However, when machining a selected crankshaft bend, with that bend as the rotation centerline, the conventional center rest cannot provide effective support due to the eccentricity. Therefore, it is necessary to design an eccentric rest that can adapt to the eccentricity to support the crankshaft diameter and achieve precision machining of the bend. Existing eccentric rests are usually complex in structure, lack versatility, and are difficult to guarantee coaxiality and repeatability during frequent disassembly and assembly. This has become a key factor restricting the machining quality of crankshafts with large eccentricities. Utility Model Content

[0005] This utility model addresses the above-mentioned problems and overcomes the shortcomings of the existing technology by providing a follow-up eccentric tooling for crankshaft grinding. It features strong versatility, precise positioning, high rigidity, and easy assembly and disassembly, effectively improving the machining accuracy of crankshafts with large eccentricity.

[0006] To achieve the above objectives, the present invention adopts the following technical solution.

[0007] This utility model provides a follower eccentric fixture for crankshaft grinding, comprising a split follower eccentric frame and a ring support mechanism. The split follower eccentric frame is mounted on the ring support mechanism. The split follower eccentric frame includes a follower ring and a shaft diameter support mechanism. The shaft diameter support mechanism is connected to the follower ring, and the follower ring is located on the ring support mechanism. The shaft diameter support mechanism is used to clamp and support the crankshaft workpiece. The ring support mechanism is connected to the guide rail on the machine tool and can reciprocate along the guide rail under the power drive of the machine tool.

[0008] Furthermore, the follower ring includes a ring body and a web, with the web connected to the inner side of the ring body and a hollowed-out area in the middle. A shaft diameter support mechanism is detachably connected to the web, and the web has several positioning connection holes that detachably connect with the shaft diameter support mechanism. The shaft diameter support mechanism is fixed to the positioning connection holes by bolts. The height of the shaft diameter support mechanism fixed to the web can be adjusted using the positioning connection holes, adapting to the machining requirements of crankshafts with different eccentricities.

[0009] Furthermore, the shaft diameter support mechanism includes a pressure plate and a support base, and the pressure plate and the support base are connected by bolts and a set of gap adjusting shims; the pressure plate is provided with a first semicircular structure, and the support base is provided with a second semicircular structure that is adapted to the first semicircular structure; the first semicircular structure is provided with a first inclined stop structure, and the second semicircular structure is provided with a second inclined stop structure that mates with the first inclined stop structure.

[0010] Furthermore, the shaft diameter support mechanism also includes two semi-circular bushings, which are respectively fitted and fixed in the first semi-circular structure and the second semi-circular structure. The end faces of the two semi-circular bushings do not contact each other when the crankshaft workpiece is clamped.

[0011] Furthermore, the gap adjusting shim group is composed of several stainless steel shims with a thickness of 0.1mm stacked together, and the gap adjusting shim group is sandwiched at the connection end face between the pressure plate and the support base.

[0012] Furthermore, the ring support mechanism includes a base, a first support roller assembly, a second support roller assembly, and a lead screw transmission mechanism. The base is slidably connected to the guide rail of the machine tool. The first and second support roller assemblies are disposed opposite to each other at both ends of the upper surface of the base. The lead screw transmission mechanism is connected through the base. A split-type follower eccentric frame is disposed between the first and second support roller assemblies. Driven by the lead screw transmission mechanism, the first and second support roller assemblies can move towards and away from each other on the base.

[0013] Furthermore, the height of the first support roller assembly on the base is lower than the height of the second support roller assembly; both the first support roller assembly and the second support roller assembly include a wheel mounting seat and a roller, the wheel mounting seat is slidably connected to the base, and the roller is installed in the wheel mounting seat and can rotate on the wheel mounting seat.

[0014] Furthermore, the center of the first support roller assembly is lower than the center of the second support roller assembly, and the height difference is 5%-8% of the outer radius of the follower ring.

[0015] The beneficial effects of this utility model are: 1. The split-type follower eccentric bracket of this utility model adopts a split structure design. Through the cooperation of the pressure plate, support base, and follower ring, it realizes quick clamping and disassembly of the crankshaft diameter, which is convenient to operate and has a compact structure. Through the several positioning connection holes provided on the web, the height position of the shaft diameter support mechanism fixed on the web can be adjusted, thus adapting to the crankshaft machining requirements of different eccentricities, improving the versatility of tooling, and reducing the tooling change cost of crankshaft machining. Through the design of the inclined surface stop structure, this utility model enables the pressure plate and follower ring to generate radial clamping force when the bolts are tightened, realizing self-centering and resetting, ensuring repeatability and positioning accuracy, and effectively solving the problem of coaxiality reduction caused by frequent disassembly and assembly.

[0016] 2. This utility model employs a staggered support roller assembly, with the height difference set at 5%-8% of the outer radius of the follower ring. The follower ring's own weight generates a stable eccentric torque, eliminating radial movement caused by screw drive backlash and providing preload during grinding, significantly suppressing grinding chatter and ensuring the cylindricity of the crankshaft's turning diameter. This utility model also features a clearance adjusting shim assembly at the connection between the pressure plate and the support base. This shim assembly is made of stacked 0.1mm thick stainless steel shims, which can flexibly compensate for bushing machining errors and wear, effectively extending the tooling's service life and reducing maintenance costs. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural schematic diagram of a follower eccentric tooling for crankshaft grinding according to this utility model.

[0018] Figure 2 This is a schematic diagram of the planar structure of a follower eccentric tooling for crankshaft grinding according to this utility model.

[0019] Figure 3 This is a schematic diagram of the follower ring of a follower eccentric tooling for crankshaft grinding according to this utility model.

[0020] Figure 4 This is a schematic diagram of the pressure plate of a follower eccentric tooling for crankshaft grinding according to this utility model.

[0021] Figure 5 This is a schematic diagram of the support base of a follower eccentric tooling for crankshaft grinding according to this utility model.

[0022] Figure 6 This is a diagram showing the usage state of a follower eccentric tooling for crankshaft grinding according to this utility model.

[0023] In the diagram, the markings are: 1 for follower ring, 2 for shaft diameter support mechanism, 3 for ring support seat mechanism, 4 for wheel mounting seat, 5 for roller, and 6 for crankshaft workpiece. 101 is the ring body, 102 is the web, and 103 is the positioning connection hole; 201 is a pressure plate, 2011 is the first inclined surface stop structure, and 2012 is the first semi-circular structure; 202 is the support base, 2021 is the second inclined surface stop structure, 2022 is the second semi-circular structure; 203 is the semi-circular bushing; 301 is the first support roller assembly, 302 is the second support roller assembly, 303 is the base, and 304 is the lead screw transmission mechanism. Detailed Implementation

[0024] To make the technical problems solved, the technical solutions, and the beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0025] Combination Figure 1 , Figure 2 and Figure 6 As shown in the embodiment of this utility model, a follower eccentric fixture for crankshaft grinding includes a split follower eccentric frame and a ring support mechanism 3. The split follower eccentric frame is mounted on the ring support mechanism 3. Specifically, the split follower eccentric frame includes a follower ring 1 and a shaft diameter support mechanism 2. The shaft diameter support mechanism 2 is connected to the follower ring 1 and is used to clamp and support the crankshaft workpiece 6. The follower ring 1 is located on the ring support mechanism 3. The ring support mechanism 3 is connected to the guide rail on the machine tool and can reciprocate along the guide rail under the power drive of the machine tool to realize the feed motion during the grinding process.

[0026] like Figure 3As shown, the follower ring 1 includes a ring body 101 and a web 102. The web 102 is connected to the inner side of the ring body 101, and the middle part of the web 102 is a hollow area to reduce weight. The shaft diameter support mechanism 2 is detachably connected to the web 102. The web 102 is provided with a plurality of positioning connection holes 103 that cooperate with the shaft diameter support mechanism 2. The shaft diameter support mechanism 2 is fixed to the positioning connection holes 103 by bolts. In this embodiment, the height position of the shaft diameter support mechanism 2 fixed on the web 102 can be adjusted by the plurality of positioning connection holes 103 provided on the web 102, which can adapt to the crankshaft machining requirements with different eccentricities and improve the versatility of the tooling.

[0027] like Figure 4 and Figure 5 As shown, the shaft diameter support mechanism 2 includes a pressure plate 201 and a support base 202. The pressure plate 201 and the support base 202 are connected by bolts and a set of gap adjusting shims. A first semicircular structure 2012 is provided on the pressure plate 201, and a second semicircular structure 2022 adapted to the first semicircular structure 2012 is provided on the support base 202. A first inclined stop structure 2011 is provided on the first semicircular structure 2012, and a second inclined stop structure 2021 that mates with the first inclined stop structure 2011 is provided on the second semicircular structure 2022. In a preferred embodiment, both the first inclined stop structure 2011 and the second inclined stop structure 2021 are fitted together to form a 1:10 taper. Under the action of bolt preload, radial clamping force is generated between the first inclined surface stop structure 2011 and the second inclined surface stop structure 2021, which not only ensures the coaxiality requirement of the whole circle formed by the first semicircular structure 2012 and the second semicircular structure 2022 and the outer circle of the follower ring 1, but also enables self-centering and reset during frequent disassembly and assembly, with repeatability accuracy ≤0.02mm.

[0028] In a specific embodiment, the shaft diameter support mechanism 2 further includes two semi-circular bushings 203; the two semi-circular bushings 203 are respectively fitted and fixed in the first semi-circular structure 2012 and the second semi-circular structure 2022. The semi-circular bushings 203 are prepared according to the shaft diameter dimensions of the crankshaft workpiece 6 and are used to clamp the shaft diameter of the crankshaft workpiece 6. When clamping the crankshaft workpiece 6, the end faces of the two semi-circular bushings 203 do not contact each other, thereby avoiding interference due to deformation of the end faces under force and ensuring tightness of fit.

[0029] In a specific embodiment, the gap adjusting shim assembly is composed of several 0.1mm thick stainless steel shims stacked together. The gap adjusting shim assembly is clamped at the connection end face between the pressure plate 201 and the support base 202. By adding or removing stainless steel shims, the diameter of the circular hole formed by the first semicircular structure 2012 and the second semicircular structure 2022 can be finely adjusted to compensate for the machining error of the outer circle of the semicircular bushing 203 and the wear after multiple disassemblies and reassemblies, thereby extending the service life of the eccentric frame without replacing the bushing.

[0030] In a specific embodiment, the ring support mechanism 3 includes a base 303, a first support roller assembly 301, a second support roller assembly 302, and a lead screw transmission mechanism 304; the base 303 is slidably connected to the guide rail of the machine tool. The first support roller assembly 301 and the second support roller assembly 302 are disposed opposite to each other at both ends of the upper surface of the base 303. The lead screw transmission mechanism 304 is connected through the base 303. A split-type follower eccentric frame is disposed between the first support roller assembly 301 and the second support roller assembly 302. Handwheels are provided at both ends of the lead screw transmission mechanism 304. Driven by the lead screw transmission mechanism 304, rotating the handwheels converts the movement into linear motion of the lead screw transmission mechanism 304 inside the base 303, causing the first support roller assembly 301 and the second support roller assembly 302 to move towards or away from each other on the base 303, thereby adjusting the distance between the first support roller assembly 301 and the second support roller assembly 302 to adapt to follower rings 1 with different outer diameters.

[0031] Furthermore, on the base 303, the height of the first support roller assembly 301 is lower than the height of the second support roller assembly 302. Both the first support roller assembly 301 and the second support roller assembly 302 include a wheel mounting seat 4 and a roller 5. The wheel mounting seat 4 is slidably connected to the base 303, and the roller 5 is mounted in the wheel mounting seat 4 and can rotate on the wheel mounting seat 4. The center of the roller in the first support roller assembly 301 is lower than the center of the roller in the second support roller assembly 302, with a height difference of 5%-8% of the outer radius of the follower ring 1. This height difference allows the follower ring 1 to form a stable eccentric torque under its own weight, which can eliminate radial movement caused by the lead screw drive backlash and provide an adjustable preload during grinding, effectively suppressing grinding chatter and thus further improving the grinding accuracy of the crankshaft bevel.

[0032] In use, first, the follower ring 1 is erected, and the crankshaft is inserted into the follower ring 1 to the position of the shaft diameter to be supported. Then, the support base 202, pressure plate 201, and semi-circular bushing 203 are installed and assembled with the crankshaft workpiece 6 shaft diameter, and the fastening bolts at the corresponding connections are tightened to complete the assembly of the split-type follower eccentric frame. The assembled split-type follower eccentric frame and crankshaft workpiece 6 assembly is hoisted and lowered onto the first support roller assembly 301 and the second support roller assembly 302 of the ring support base mechanism 3. The process chucks on both sides of the crankshaft workpiece 6 are inserted into the positioning holes of the eccentric fixture that have been adjusted on the machine tool. Then, the runout error of the follower ring 1 is adjusted through the lead screw transmission mechanism 304 inside the ring support base mechanism 3. During this process, the runout of the outer circle of the follower ring 1 should not exceed 0.02mm. After the tooling of this utility model is assembled and adjusted, the crankshaft workpiece 6 can be ground.

[0033] It is understood that the above specific description of this utility model is only used to illustrate this utility model and is not limited to the technical solutions described in the embodiments of this utility model. Those skilled in the art should understand that modifications or equivalent substitutions can still be made to this utility model to achieve the same technical effect; as long as the use needs are met, they are all within the protection scope of this utility model.

Claims

1. A follower eccentric tooling for crankshaft grinding, characterized in that: The device includes a split-type follower eccentric frame and a ring support mechanism. The split-type follower eccentric frame is mounted on the ring support mechanism. The split-type follower eccentric frame includes a follower ring and a shaft diameter support mechanism. The shaft diameter support mechanism is connected to the follower ring, and the follower ring is located on the ring support mechanism. The shaft diameter support mechanism is used to clamp and support the crankshaft workpiece. The ring support mechanism is connected to the guide rail on the machine tool and can reciprocate along the guide rail under the power drive of the machine tool.

2. The follower eccentric tooling for crankshaft grinding according to claim 1, characterized in that: The follower ring includes a ring body and a web. The web is connected to the inner side of the ring body, and the middle part of the web is a hollow area. The shaft diameter support mechanism is detachably connected to the web. The web is provided with several positioning connection holes that cooperate with the shaft diameter support mechanism for detachable connection. The shaft diameter support mechanism is fixed to the positioning connection holes by bolts.

3. The follower eccentric tooling for crankshaft grinding according to claim 2, characterized in that: The shaft diameter support mechanism includes a pressure plate and a support base. The pressure plate and the support base are connected by bolts and a set of gap adjustment shims. The pressure plate is provided with a first semicircular structure, and the support base is provided with a second semicircular structure that is adapted to the first semicircular structure. The first semicircular structure is provided with a first inclined stop structure, and the second semicircular structure is provided with a second inclined stop structure that is matched and connected with the first inclined stop structure.

4. The follower eccentric tooling for crankshaft grinding according to claim 3, characterized in that: The shaft diameter support mechanism also includes two semi-circular bushings, which are respectively fitted and fixed in the first semi-circular structure and the second semi-circular structure. The end faces of the two semi-circular bushings do not contact each other when the crankshaft workpiece is clamped.

5. The follower eccentric tooling for crankshaft grinding according to claim 3, characterized in that: The gap adjusting shim group is composed of several stainless steel shims with a thickness of 0.1mm stacked together, and the gap adjusting shim group is sandwiched at the connection end face between the pressure plate and the support base.

6. The follower eccentric tooling for crankshaft grinding according to claim 1, characterized in that: The ring support mechanism includes a base, a first support roller assembly, a second support roller assembly, and a lead screw transmission mechanism. The base is slidably connected to the guide rail of the machine tool. The first support roller assembly and the second support roller assembly are disposed opposite each other at both ends of the upper surface of the base. The lead screw transmission mechanism is connected through the base. Driven by the lead screw transmission mechanism, the first support roller assembly and the second support roller assembly can move towards each other and away from each other on the base.

7. The follower eccentric tooling for crankshaft grinding according to claim 6, characterized in that: The height of the first support roller assembly on the base is lower than the height of the second support roller assembly; both the first support roller assembly and the second support roller assembly include a wheel mounting seat and a roller, the wheel mounting seat is slidably connected to the base, and the roller is installed in the wheel mounting seat and can rotate on the wheel mounting seat.

8. The follower eccentric tooling for crankshaft grinding according to claim 7, characterized in that: The center of the first support roller assembly is lower than the center of the second support roller assembly, and the height difference is 5%-8% of the outer radius of the follower ring.

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