Engine crankshaft balance optimization mechanism

Abstract

The utility model discloses an engine crankshaft balance optimization mechanism relates to internal -combustion engine technical field, including crankshaft body, be equipped with the main shaft neck on the crankshaft body, connecting rod axle neck and the crank arm of connecting both, be equipped with the balance weight on the crank arm, the balance weight is equipped with an avoidance recess on the side surface of adjacent connecting rod axle neck, the vertical section profile of avoidance recess is arc, the utility model discloses the avoidance recess of accurate design provides the necessary physical space for adjacent moving parts, makes the balance weight under the condition of weight reduction, better provides the balance effect, has improved the operation reliability of engine.

Description

Technical Field

[0001] This utility model relates to internal combustion engine technology, specifically to an engine crankshaft balancing optimization mechanism. Background Technology

[0002] The crankshaft is the core component of an engine, its function being to convert the reciprocating motion of the piston into rotational motion and output power. Because the piston and connecting rod assemblies generate enormous inertial forces during operation, counterweights are typically placed on the crankshaft crank arms to balance these forces and reduce engine vibration and noise. The most common balancing method involves casting or forging counterweights of a certain mass into the extension of each crank arm; these counterweights use the centrifugal force generated by their rotation to counteract some of the inertial forces.

[0003] However, in existing technologies, especially in multi-cylinder V-type or horizontally opposed engines, the compact engine structure and small cylinder center distance result in a very close distance between adjacent connecting rod journals. To provide sufficient balancing force, the mass and volume of the balance weight are often designed to be large. However, when the balance weight rotates with the crankshaft, its outer edge profile is very prone to motion interference with adjacent connecting rod journals or connecting rod big ends mounted on the journals. To avoid interference, traditional designs usually reduce the size and mass of the balance weight, but this sacrifices the balancing effect, which leads to increased engine vibration and, over time, accelerated crankshaft wear. Utility Model Content

[0004] The purpose of this invention is to provide an engine crankshaft balancing optimization mechanism to solve problems such as the impact of traditional designs on crankshaft balance and the resulting increased wear in the prior art.

[0005] First aspect: In order to achieve the above objectives, the present invention provides the following technical solution: an engine crankshaft balancing optimization mechanism, including a crankshaft body, wherein the crankshaft body is provided with a main journal, a connecting rod journal and a crank arm connecting the two, and a balance block is provided on the crank arm, wherein a clearance groove is provided on the side surface of the balance block facing the adjacent connecting rod journal, and the vertical cross-sectional profile of the clearance groove is arc-shaped.

[0006] The contour of the clearance groove matches the outer circular motion trajectory of the adjacent connecting rod journal, and a safe clearance is maintained between them.

[0007] The depth of the clearance groove gradually increases from the outer edge of the balance block toward the crank arm, forming a smoothly transitioning curved surface structure.

[0008] The balance block is provided with at least one weight-reducing hole inside the avoidance groove, and the weight-reducing hole is located away from the bottom wall of the avoidance groove.

[0009] Furthermore, the width of the safety gap is not less than 1 mm.

[0010] Furthermore, the clearance groove is arranged symmetrically about the line connecting the center of mass of the balance block and the center of rotation of the crankshaft body.

[0011] Furthermore, the surface of the clearance groove is a smooth surface that has been polished, and the clearance groove and the balance block are integrally formed by casting.

[0012] Furthermore, the top and bottom walls of the clearance groove are coated with a lubricating layer.

[0013] As described in the first aspect above, the crankshaft balancing optimization mechanism is applied to a V-type engine or a horizontally opposed engine.

[0014] Compared with the prior art, the engine crankshaft balancing optimization mechanism provided by this utility model...

[0015] 1. By setting a balance block on the crank arm, and providing a clearance groove on the side of the balance block facing the connecting rod journal, the vertical cross-sectional profile of the clearance groove is arc-shaped, providing the necessary physical space for adjacent moving parts, eliminating the risk of interference during rotation, improving the operational reliability of the engine, and the designed clearance groove is made by removing the part of the balance block that contributes less to the balancing torque, and by optimizing the mass distribution of the remaining part, the balance block can still provide a good balancing effect with limited weight reduction.

[0016] 2. The key to ensuring the dynamic balance performance of the optimized balance block is to arrange the clearance grooves symmetrically about the line connecting the center of mass of the balance block and the center of rotation of the crankshaft. Symmetrical machining means that the material removed from the balance block is symmetrical about its center of mass. After this operation, the new center of mass of the balance block is still strictly located on the original line. No new uncontrollable unbalanced torque will be generated due to the grooves. This ensures that the balance block only generates the required centrifugal force without introducing additional disturbances, simplifying the dynamic balance correction process of the entire crankshaft. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings.

[0018] Figure 1 This is a schematic diagram of the overall structure of the engine crankshaft balancing optimization mechanism provided in an embodiment of the present utility model;

[0019] Figure 2A schematic diagram of the structure of the balance block and adjacent connecting rod shaft diameter and other components provided in this embodiment of the utility model;

[0020] Figure 3 This is a schematic diagram of the structure of the balance block and the clearance groove provided in the embodiment of the present utility model;

[0021] Figure 4 This is a schematic diagram of the structure of components such as the balance block and weight reduction hole provided in an embodiment of the present utility model.

[0022] Explanation of reference numerals in the attached figures:

[0023] 1. Crankshaft body; 2. Main journal; 3. Connecting rod journal; 4. Crank arm; 5. Balance weight; 6. Clearance groove; 7. Safety clearance; 8. Weight reduction hole; 9. Lubrication layer. Detailed Implementation

[0024] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0025] As attached Figure 1 To be continued Figure 4 As shown:

[0026] Example 1:

[0027] This utility model provides an engine crankshaft balancing optimization mechanism, including a crankshaft body 1. The crankshaft body 1 is provided with a main journal 2, a connecting rod journal 3 and a crank arm 4 connecting the two. The crank arm 4 is provided with a balance block 5. A clearance groove 6 is formed on the side surface of the balance block 5 facing the adjacent connecting rod journal 3. The vertical cross-sectional profile of the clearance groove 6 is arc-shaped.

[0028] It should be noted that by setting a balance block 5 on the crank arm 4, and providing an avoidance groove 6 on the side of the balance block 5 facing the connecting rod journal 3, the vertical cross-sectional profile of the avoidance groove 6 is arc-shaped, providing the necessary physical space for adjacent moving parts, eliminating the risk of interference during rotation, and improving the operational reliability of the engine. Moreover, the designed avoidance groove 6 is made by removing a portion of the material on the balance block 5 that contributes less to the balancing torque, and by optimizing the mass distribution of the remaining portion, so that the balance block 5 can still provide a good balancing effect with limited weight reduction.

[0029] Working principle: When the crankshaft rotates at high speed, the balance block 5 moves in a circular motion along with the crank arm 4. By precisely machining an arc-shaped avoidance groove 6 on the side wall of the balance block 5 facing the danger zone, the groove always maintains a safe physical gap with the adjacent connecting rod journal 3 throughout the entire rotation cycle of the crankshaft. Thus, while fully utilizing the inertial balancing effect, the balance block 5 cleverly avoids the area where a collision would occur, achieving a balance between performance and reliability within a limited space.

[0030] In this embodiment: the contour of the avoidance groove 6 matches the outer circular motion trajectory of the adjacent connecting rod journal 3, and a safe gap 7 is maintained between them.

[0031] It should be noted that "matching" here does not mean that the shapes are exactly the same, but rather that the profile of the avoidance groove 6 is designed based on the motion trajectory of the adjacent connecting rod journal 3 at all possible positions during crankshaft rotation. Through computer-aided engineering motion simulation analysis, the final shape of the groove is accurately calculated to ensure that the gap between the inner surface of the groove and the moving parts is greater than zero at any phase angle of crankshaft rotation of 360 degrees, thereby maximizing the avoidance effect and minimizing material removal.

[0032] In this embodiment, the width of the safety gap 7 is not less than 1 mm.

[0033] It should be noted that by setting the installation gap to be no less than 1mm, the thermal expansion of components such as the crankshaft under high-temperature conditions is taken into account firstly, thus avoiding the loss of gap due to expansion; secondly, it accommodates the manufacturing tolerances and assembly errors of parts, ensuring consistency in mass production and providing redundancy for the safe operation of the engine under extreme conditions.

[0034] In this embodiment, the depth of the avoidance groove 6 gradually increases from the outer edge of the balance block 5 toward the crank arm 4, forming a smoothly transitioning curved surface structure.

[0035] It should be noted that this smooth curved surface with gradual depth avoids sharp corners and abrupt changes in cross-section, reduces stress concentration, improves the fatigue strength of the balance block 5 under alternating loads, reduces the risk of cracks from the groove, and the smooth streamlined curved surface helps to reduce air resistance during high-speed rotation, which has a positive effect on reducing wind resistance loss.

[0036] In this embodiment, the avoidance groove 6 is arranged symmetrically about the line connecting the center of mass of the balance block 5 and the rotation center of the crankshaft body 1.

[0037] It should be noted that symmetrically arranging the clearance groove 6 about the line connecting the center of mass of the balance block 5 and the crankshaft rotation center is the key to ensuring the dynamic balance performance of the optimized balance block 5. Symmetrical machining means that the material removed from the balance block 5 is symmetrical about its center of mass. After this operation, the new center of mass of the balance block 5 is still strictly located on the original line. It will not generate new and uncontrollable unbalanced torque due to the groove, thus ensuring that the balance block 5 only generates the required centrifugal force without introducing additional disturbances, simplifying the dynamic balancing correction process of the entire crankshaft.

[0038] In this embodiment: at least one weight-reducing hole 8 is provided on the balance block 5 and inside the avoidance groove 6, and the weight-reducing hole 8 is located away from the bottom wall of the avoidance groove 6.

[0039] It should be noted that the setting of the weight reduction hole 8 is a way to balance the balance block 5 inertia. Its main purpose is not simply to reduce weight, but to accurately adjust the rotational inertia and mass distribution of the balance block 5 without affecting the avoidance function. The requirement that the weight reduction hole 8 be far away from the bottom wall of the groove is to ensure the structural strength and rigidity of the avoidance groove 6 area and to avoid weakening its bending and torsional resistance due to the opening.

[0040] By increasing or decreasing the number, size, and position of the weight reduction holes 8, the balance performance of the balance block 5 can be finely adjusted to adapt to the balance requirements of different engine models, thereby improving the versatility and adjustability of the design platform.

[0041] In this embodiment: the surface of the avoidance groove 6 is a smooth surface that has been polished, and the avoidance groove 6 and the balance block 5 are integrally formed by casting.

[0042] It should be noted that polishing the groove surface to form a smooth surface is an effective fatigue-resistant manufacturing process. Polishing can remove micro-cracks, machining marks and other defects on the material surface, improve the fatigue limit of the surface, and prevent the generation of stress concentration sources.

[0043] By adopting a one-piece casting method, the integrity and material continuity of the balance block 5 are guaranteed. Its strength is far higher than that of the balance block 5 connected by welding or bolting. At the same time, the one-piece molding also avoids assembly errors, improves the reliability and consistency of the product, and is suitable for industrial production.

[0044] In this embodiment, the top and bottom walls of the clearance groove 6 are coated with a lubricating layer 9.

[0045] It should be noted that this design is another safety feature. In extreme cases, such as engine knocking causing excessive instantaneous deformation of the crankshaft, a solid lubricating layer 9 is coated on the surface of this groove. The lubricating layer 9 is made of Teflon coating material, which can provide temporary lubrication in the event of accidental contact, preventing catastrophic failures such as crankshaft seizure caused by dry friction. This buys valuable time for the engine electronic control system to identify and cut off power, thereby minimizing potential losses.

[0046] The foregoing description only illustrates certain exemplary embodiments of the present invention. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. An engine crankshaft balancing optimization mechanism, characterized in that, include: The crankshaft body (1) is provided with a main journal (2), a connecting rod journal (3) and a crank arm (4) connecting the two. The crank arm (4) is provided with a balance block (5). The balance block (5) has a clearance groove (6) on one side surface facing the adjacent connecting rod journal (3). The vertical cross-sectional profile of the clearance groove (6) is arc-shaped. The outline of the clearance groove (6) matches the outer circular motion trajectory of the adjacent connecting rod journal (3), and a safe clearance (7) is maintained between them. The depth of the clearance groove (6) gradually increases from the outer edge of the balance block (5) toward the crank arm (4), forming a smooth transition curved surface structure; At least one weight-reducing hole (8) is provided on the balance block (5) and inside the avoidance groove (6), and the weight-reducing hole (8) is located away from the bottom wall of the avoidance groove (6).

2. The engine crankshaft balancing optimization mechanism according to claim 1, characterized in that, The width of the safety gap (7) is not less than 1 mm.

3. The engine crankshaft balancing optimization mechanism according to claim 1, characterized in that, The clearance groove (6) is arranged symmetrically about the line connecting the center of mass of the balance block (5) and the center of rotation of the crankshaft body (1).

4. The engine crankshaft balancing optimization mechanism according to claim 1, characterized in that, The surface of the avoidance groove (6) is a smooth surface that has been polished, and the avoidance groove (6) and the balance block (5) are integrally formed by casting.

5. The engine crankshaft balancing optimization mechanism according to claim 1, characterized in that, The top and bottom walls of the clearance groove (6) are coated with a lubricating layer (9).

6. The engine crankshaft balancing optimization mechanism according to any one of claims 1-5, characterized in that: The crankshaft body (1) is used in V-type engines or horizontally opposed engines.

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