WO2015043207A1

WO2015043207A1 - Crankshaft assembly of inline four-cylinder engine and molding method therefor

Info

Publication number: WO2015043207A1
Application number: PCT/CN2014/078100
Authority: WO
Inventors: 宋溦; 蔡继春; 卢艳坤; 李向春; 李德全
Original assignee: 北汽福田汽车股份有限公司; 北京智科投资管理有限公司
Priority date: 2013-09-25
Filing date: 2014-05-22
Publication date: 2015-04-02
Also published as: CN104439364B; CN104439364A

Abstract

A molding method for a crankshaft assembly of an inline four-cylinder engine comprises the following steps: S1, adjusting a center of gravity of the crankshaft having a first balancing block and a second balancing block to coincide with a central axis of the crankshaft; S2, increasing the mass of the first balancing block and the second balancing block to deflect the center of gravity of the crankshaft from the central axis of the crankshaft; and S3, drilling removing weight holes on the first balancing block and the second balancing block respectively to make the center of gravity of the crankshaft assembly to coincide with the central axis of the crankshaft. A crankshaft assembly of an inline four-cylinder engine is also disclosed. The molding method for the crankshaft assembly simplifies the complexity of the operation, enhances the production efficiency, and reduces the production cost.

Description

Crankshaft assembly for in-line four-cylinder engine and forming method thereof

Field of the Invention This invention relates to the automotive field, and more particularly to a crankshaft assembly for an inline four cylinder engine and a method of forming the same. Say

Background technique

In recent years, with the development of the automobile industry, the requirements for vehicle comfort are getting higher and higher. As the source of automobile power, the control requirements for noise and vibration are more and more strict. The dynamic balance design of the engine crankshaft is an important part of it.

Book

The in-line four-cylinder engine is the most widely used engine structure type, and the dynamic balance design of the crankshaft is particularly important, and its dynamic balance design goal is to optimize the crankshaft dynamic imbalance to a minimum, so that the crankshaft is brought during engine operation. The engine has minimal yaw and vibration.

However, in the production and manufacturing process, the crankshaft needs to meet the dynamic balance design requirements of the crankshaft. The crankshaft may need to process the heavy holes on any one or more balance blocks, which makes the tooling design of the station difficult and difficult to operate. High, long processing time. Summary of the invention

The present invention aims to solve at least one of the technical problems existing in the prior art. Accordingly, it is an object of the present invention to provide a method of forming a crankshaft assembly for an in-line four-cylinder engine which is less difficult and has high production efficiency and low production cost.

Another object of the present invention is to provide a crankshaft assembly for an inline four-cylinder engine which is less difficult and has high production efficiency and low production cost.

A molding method for a crankshaft assembly for an in-line four-cylinder engine according to a first aspect of the present invention, comprising the steps of: S1, adjusting a center of gravity of a crankshaft having a first balance weight and a second balance weight to a center of the crankshaft The axes coincide; S2, increasing the mass of the first balance block and the second balance block such that the center of gravity of the crankshaft assembly is offset from the central axis of the crankshaft; and S3, for the first balance The block and the second balance block drill a heavy hole, respectively, such that the center of gravity of the crankshaft assembly coincides with the central axis of the crankshaft.

Method for forming a crankshaft assembly for an in-line four-cylinder engine according to the present invention, the crankshaft assembly is machined to a heavy-hole There are only two axial positions, namely the first balance block and the second balance block, which reduces the difficulty of drilling the tool assembly of the crankshaft assembly, simplifies the complexity of the station operation, improves the production efficiency, and Reduced production costs.

Optionally, the first balance block and the second balance block in step S1 are located on the same side of the central axis of the crankshaft. Thereby, the angular distribution area of the de-heavy hole is reduced.

Further, the increase of the mass of the first balance block in step S2 is obtained by increasing the radius, the width or the thickness of the first balance block; the increase of the mass of the second balance block is caused by the second balance The radius, width or thickness of the block is increased.

Optionally, the crankshaft has a central main journal, and the first balance block and the second balance block are symmetrical about the central main journal.

Further, the crankshaft further includes: at least one third balance block, at least one of the third balance blocks being disposed between the first balance block and the central main journal; and at least one fourth balance block, at least One of the fourth balance blocks is disposed between the second balance weight and the center main journal, and at least one of the fourth balance weights and at least one of the third balance weights are symmetrical about the center main journal.

A crankshaft assembly for an in-line four-cylinder engine according to a second aspect of the present invention, comprising: a crankshaft having a center main journal; a first balancer, the first balancer being disposed on the crankshaft and located at the a side of the center main journal; and a second balance block disposed on the crankshaft and spaced apart from the first balance block in the axial direction of the crankshaft, the second balance a block is located on the other side of the central main journal, wherein the first balance block is provided with a first predetermined mass and a first de-weighted hole, and the second balance block is provided with a second predetermined mass and a Second, the heavy holes are removed such that the center of gravity of the crankshaft assembly coincides with the central axis of the crankshaft.

According to the crankshaft assembly for an in-line four-cylinder engine of the present invention, the axial position of the crankshaft assembly machining de-weighting hole is fixed in a designated area, that is, the first balance block and the second balance block, so that the dynamic balance detecting station hits When the heavy hole is removed, the distribution range of the drilled heavy hole is small, thereby reducing the difficulty of tooling design for drilling the heavy hole, simplifying the complexity of the work of the station, improving the production efficiency, and reducing the production cost.

Optionally, the first weight and the second weight are symmetric about the center spindle and are respectively adjacent to both ends of the crankshaft. Thereby, the dynamic balance design requirements of the crankshaft assembly can be better achieved.

Further, the quality of the first predetermined mass is equal to the mass of the second predetermined mass.

Optionally, the mass of the first predetermined mass is obtained by increasing a radius, a width or a thickness of the first weight; the mass of the second predetermined mass is determined by a radius of the second balancing block, The width or thickness is increased.

Further, the crankshaft assembly further includes: at least one third balance block, at least one of the third balance blocks being disposed between the first balance block and the central main journal; and at least one fourth balance block, at least one The fourth balance block is disposed between the second balance weight and the center main journal, and at least one of the fourth balance weight and at least one of the third balance weights are symmetrical about the center main journal.

The additional aspects and advantages of the invention will be set forth in part in the description which follows. DRAWINGS

The above and/or additional aspects and advantages of the present invention will become apparent and readily understood from

1 is a schematic view showing a state in which a crankshaft assembly increases the mass of a first balance weight and a second balance weight according to an embodiment of the present invention;

2 is a schematic illustration of a crankshaft assembly drilling a heavy hole in a first weight and a second weight in accordance with an embodiment of the present invention. detailed description

The embodiments of the present invention are described in detail below, and the examples of the embodiments are illustrated in the drawings, wherein the same or similar reference numerals are used to refer to the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are intended to be illustrative only, and are not to be construed as limiting.

In the description of the present invention, it is to be understood that the terms "center", "lateral", "upper", "lower", "left", "right", "vertical", "horizontal", "top", The orientation or positional relationship of the "bottom", "inside", "outside" and the like is based on the orientation or positional relationship shown in the drawings, and is merely for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the indicated device. Or the components must have a particular orientation, are constructed and operated in a particular orientation, and are therefore not to be construed as limiting the invention. Moreover, the terms "first" and "second" are used for the purpose of description only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, features defining "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more unless otherwise stated.

In the description of the present invention, it should be noted that the terms "installation", "connected", and "connected" should be understood broadly, and may be either fixed or detachable, unless explicitly stated or defined otherwise. Connected, or connected in one piece; can be directly connected, or indirectly connected through an intermediate medium, and can be internal to the two elements. The specific meaning of the above terms in the present invention can be understood by a person of ordinary skill in the art.

A crankshaft assembly for an in-line four-cylinder engine in accordance with an embodiment of the present invention will now be described with reference to FIGS. 1 and 2. 100.

As shown in FIGS. 1 and 2, a molding method of a crankshaft assembly 100 for an in-line four-cylinder engine according to an embodiment of the first aspect of the present invention includes the following steps:

S1, adjusting the center of gravity 101 of the crankshaft 1 having the first balance block 2 and the second balance block 3 to coincide with the central axis 12 of the crankshaft 1;

52. increasing the mass of the first weight 2 and the second weight 3 such that the center of gravity 101 of the crankshaft assembly 100 is offset from the central axis 12 of the crankshaft 1;

53. The heavy holes are drilled into the first balance block 2 and the second balance block 3, respectively, such that the center of gravity 101 of the crankshaft assembly 100 coincides with the central axis 12 of the crankshaft 1.

In the examples of Figs. 1 and 2, the crankshaft 1 has a first balance block 2 and a second balance block 3, a first balance block

2 and the second balance block 3 are spaced apart from each other in the axial direction of the crankshaft 1, and optionally, the first balance block 2, the second balance block 3 is integrally formed with the crankshaft 1. Here, the crankshaft 1 may be an in-line four-cylinder four-balanced crankshaft, or an in-line four-cylinder eight-balanced crankshaft or the like.

In the theoretical design stage of the crankshaft assembly 100, the center of gravity 101 of the crankshaft 1 can first be adjusted to coincide with the central axis 12 of the crankshaft 1, and then a certain mass is added to the first weight 2 and the second weight 3, respectively. The static unbalance amount of the crankshaft assembly 100 is offset in a direction opposite to the first crank 4, at which time the center of gravity 101 of the crankshaft assembly 100 is offset from the central axis 12 of the crankshaft 1, as shown in FIG. Here, it should be noted that the amount of static imbalance of the offset can be designed according to the complexity factor of the different crankshaft assemblies 100 and the manufacturing process level of the blank. The above steps S 1 and S2 can be implemented and verified by a digital model.

At the same time, during the production process of the crankshaft assembly 100, the dynamic balance detecting step only passes through the heavy holes of the first balance block 2 and the second balance block 3 of the crankshaft, for example, can be drilled on the first balance block 2, respectively. The first de-biting hole 21, the heavy hole 31 is drilled in the second balancing block 3, so that the center of gravity 101 of the final crankshaft assembly 100 approaches the central axis 12 of the crankshaft 1, at which time the center of gravity 101 of the crankshaft assembly 100 is The central axis 12 of the crankshaft 1 substantially coincides to meet the dynamic balance design requirements of the crankshaft 1, as shown in FIG. Here, it should be noted that "the center of gravity 101 of the crankshaft assembly 100 substantially coincides with the central axis 12 of the crankshaft 1" is understood to mean that the center of gravity 101 of the crankshaft assembly 100 and the central axis 12 of the crankshaft 1 are completely coincident, at which point the center of gravity of the crankshaft assembly 100 101 is located on the central axis 12 of the crankshaft 1, or the distance between the center of gravity 101 of the crankshaft assembly 100 and the central axis 12 of the crankshaft 1 is within a small range.

That is to say, in the design stage, after the crankshaft assembly 100 is balanced, the balance weights on the same side of the central axis 12 of the crankshaft 1 on the left and right sides of the crankshaft 1 (for example, the first balance block shown in FIGS. 1 and 2) can be used. 2 and Adding a certain mass to the two balancing blocks 3), during processing, deduplicating only on the balancing block designed to increase the mass in advance (for example, the first balancing block 2 and the second balancing block 3 shown in Figs. 1 and 2) That is, the dynamic balance of the crankshaft assembly 100 is achieved by drilling the heavy holes.

According to the molding method of the crankshaft assembly 100 for an in-line four-cylinder engine according to an embodiment of the present invention, the axial position of the crankshaft assembly 100 for processing the de-duty holes is only two, that is, the first balancer 2 and the second balancer 3, so that The tooling design for drilling the heavy-duty hole of the crankshaft assembly 100 reduces the difficulty, simplifies the complexity of the operation of the station, improves the production efficiency, and reduces the production cost.

In one embodiment of the invention, the first weight 2 and the second weight 3 are located on the same side of the central axis 12 of the crankshaft 1 in step S1. Referring to FIGS. 1 and 2, the first weight 2 and the second weight 3 may be substantially fan-shaped, and the first weight 2 and the second weight 3 are both located below the central axis 12 of the crankshaft 1, specifically, first One end of the weight 2 and the second weight 3 is connected to the outer peripheral surface of the crankshaft 1, and the other end extends in a direction away from the central axis 12 of the crankshaft 1, so that when the masses of the first weight 2 and the second weight 3 are increased , it can effectively ensure that the center of gravity 101 of the crankshaft assembly 100 is offset toward the direction of the first balance block 2 and the second balance block 3 (for example, as shown in FIGS. 1 and 2), and by the first balance block 2 and the first The second balance block 3 is disposed on the same side of the central axis 12 of the crankshaft 1, and the angular distribution area of the de-weighting holes is reduced.

Further, the increase in the mass of the first weight 2 in step S2 is obtained by increasing the radius, width or thickness of the first weight 2, and the increase in the mass of the second weight 3 is caused by the radius of the second weight 3, The width or thickness is increased.

That is to say, increasing the mass of the first weight 2 can be obtained by increasing the radius of the first weight 2, that is, increasing the length of the first weight 2 in the radial direction of the crankshaft 1, or by adding the first weight 2 The width of the first balance block 2 in the circumferential direction of the crankshaft 1 is increased, or the thickness of the first balance block 2 can be increased, that is, the first balance block 2 is increased on the central axis 12 of the crankshaft 1. The distance between the two surfaces is obtained.

Increasing the mass of the second weight 3 can be obtained by increasing the radius of the second weight 3, that is, increasing the length of the second weight 3 in the radial direction of the crankshaft 1, or by increasing the width of the second weight 3, ie Increasing the opening angle of the second weight 3 in the circumferential direction of the crankshaft 1 or by increasing the thickness of the second weight 3, that is, increasing the two surfaces of the second weight 3 on the central axis 12 of the crankshaft 1 The distance between them is obtained.

Alternatively, the crankshaft 1 has a central main journal 11, the first counterweight 2 and the second counterweight 3 being symmetrical about the central main journal 11. As shown in Figures 1 and 2, the crankshaft 1 is substantially symmetrical about a central plane 111 of the central main journal 11, the first counterweight 2 and the second counterweight 3 being symmetrical about a central plane 111 of the central main journal 11. Further, the crankshaft 1 further includes: at least one third balance block and at least one fourth balance block, at least one third balance block being disposed between the first balance block 2 and the central main journal 11, at least one fourth balance block Between the second weight 3 and the central main journal 11, at least one fourth counterweight and at least one third counterweight are symmetrical about the central main journal 11.

For example, in one example of the present invention, the third balance block and the fourth balance block are each substantially fan-shaped, and the third balance block and the fourth balance block are both disposed on the crankshaft 1, and the third balance block and the central main journal 11 The distance between the first balance block 2 and the central main journal 11 is smaller than the distance between the second balance block 3 and the central main journal 11 and the distance between the second balance block 3 and the central main journal 11 is The distance between the third balance block and the central main journal 11 is equal to the distance between the fourth balance block and the central main journal 11. Optionally, the crankshaft 1 is an in-line four-cylinder eight-balanced crankshaft. It should be understood that the number of the third balance block and the fourth balance block can be set according to actual requirements to better meet the actual requirements.

The third balance block and the fourth balance block are respectively one, and the third balance block and the fourth balance block are disposed adjacent to the first balance block 2 and the second balance block 3, respectively. For example, when the crankshaft 1 is an in-line four-cylinder eight-balanced crankshaft, the distance between the third balancer and the first balancer 2 is smaller than the distance between the other balance block and the first balancer 2, and the fourth balance block and the The distance between the two balance blocks 3 is smaller than the distance between the other balance blocks and the second balance block 3. At this time, the mass of the third balance block and the mass of the fourth balance block may be increased to make the center of gravity of the crankshaft assembly 100 101 is offset from the central axis 12 of the crankshaft 1, and then the third and fourth weight removal holes are drilled on the third and fourth balance weights, respectively, such that the center of gravity 101 of the crankshaft assembly 100 is substantially parallel to the central axis 12 of the crankshaft 1. coincide.

Here, it should be noted that the increase in the mass of the third balance block is obtained by increasing the radius, the width or the thickness of the third balance block, and the increase in the mass of the fourth balance block is made by the radius, width or thickness of the fourth balance block. Increased.

Further, the crankshaft 1 further includes: a third balance block and a fourth balance block, the third balance block is disposed on the crankshaft 1 and located at a side of the first balance block 2 away from the central spindle neck 11, and the fourth balance block is disposed at On the crankshaft 1 and on the side of the second counterweight 3 remote from the central main journal 11, the fourth counterweight and the third counterweight are symmetrical about the central main journal 11.

That is, the distance between the third balance block and the central main journal 11 is greater than the distance between the first balance block 2 and the central main journal 11, and the distance between the fourth balance block and the central main journal 11 is greater than the second balance. The distance between the block 3 and the central main journal 11 is, in other words, the first counterweight 2 is located between the third counterweight and the central main journal 11, and the second counterweight 3 is located between the fourth counterweight and the central main journal 11. At this time, the mass of the third balance block and the fourth balance block may be increased, or the quality of the third balance block and the fourth balance block may not be increased.

In summary, when the crankshaft 1 is an in-line four-cylinder eight-balanced crankshaft, only the first balancer 2 and the second may be added. The mass of the weight 3 is balanced such that the center of gravity 101 of the crankshaft assembly 100 is offset from the central axis 12 of the crankshaft 1, and then the heavy holes are drilled on the first weight 2 and the second weight 3, respectively, such that the center of gravity 101 of the crankshaft assembly 100 The central axes of the crankshafts coincide.

Or merely increasing the mass of the third balance weight and the fourth balance weight such that the center of gravity 101 of the crankshaft assembly 100 is offset from the central axis 12 of the crankshaft 1, and then the heavy holes are drilled on the third balance weight and the fourth balance weight, respectively, so that The center of gravity 101 of the crankshaft assembly 100 coincides with the central axis of the crankshaft.

Or simultaneously increasing the mass of the first balance block 2, the second balance block 3, the third balance block and the fourth balance block such that the center of gravity 101 of the crankshaft assembly 100 is offset from the central axis 12 of the crankshaft 1, and then at the first balance block 2 The second balance block 3, the third balance block and the fourth balance block are respectively drilled with heavy holes such that the center of gravity 101 of the crankshaft assembly 100 coincides with the central axis of the crankshaft.

As shown in FIGS. 1 and 2, a crankshaft assembly 100 for an in-line four-cylinder engine according to an embodiment of the second aspect of the present invention includes a crankshaft 1, a first weight 2, and a second weight 3.

The crankshaft 1 has a central main journal 11. The first weight 2 is provided on the crankshaft 1 and on one side of the center main journal 11. For example, in the examples of FIGS. 1 and 2, the crankshaft 1 extends along its axial direction, the central main journal 11 is disposed on the crankshaft 1, and is located substantially at the center of the crankshaft 1, and the first balancer 2 may be substantially fan-shaped, the first balance Block 2 is located on the left side of the central main journal 11. Alternatively, the first weight 2 is integrally formed with the crankshaft 1.

The second weight 3 is disposed on the crankshaft 1, and the second weight 3 is spaced apart from the first weight 2 in the axial direction of the crankshaft 1, and the second weight 3 is located on the other side of the center spindle neck 11, wherein The first weight 2 is provided with a first predetermined mass (not shown) and a first weight removal hole 21, and the second weight 3 is provided with a second predetermined mass (not shown) and a second The heavy holes 31 are such that the center of gravity 101 of the crankshaft assembly 100 coincides with the central axis 12 of the crankshaft 1. Here, it is to be noted that the first predetermined mass and the second predetermined mass are in the first balancing block 2 and the molding method of the crankshaft assembly 100 for the in-line four-cylinder engine according to the embodiment of the first aspect of the present invention. The added mass on the second balance block 3.

Referring to FIGS. 1 and 2, the second weight 3 may be substantially fan-shaped, the second weight 3 is located on the right side of the center spindle neck 11, and the first predetermined mass and the second predetermined mass are respectively disposed on the first weight 2 And the second balance block 3, at this time, the center of gravity 101 of the crankshaft assembly 100 is offset from the central axis 12 of the crankshaft 1, that is, the center of gravity 101 of the crankshaft assembly 100 does not coincide with the central axis 12 of the crankshaft 1, the first de-weighting hole 21 and the Two de-weighting holes 31 are respectively formed on the first balance block 2 and the second balance block 3, and the first de-weighting hole 21 and the second de-weighting hole 31 are drilled on the first balance block 2 and the second balance block 3, respectively. The center of gravity 101 of the crankshaft assembly 100 can be made substantially coincident with the central axis 12 of the crankshaft 1. Here, "the center of gravity 101 of the crankshaft assembly 100 substantially coincides with the central axis 12 of the crankshaft 1" can be understood as a crankshaft. The center of gravity 101 of the assembly 100 and the central axis 12 of the crankshaft 1 are completely coincident, at which point the center of gravity 101 of the crankshaft assembly 100 is located on the central axis 12 of the crankshaft 1, or the distance between the center of gravity 101 of the crankshaft assembly 100 and the central axis 12 of the crankshaft 1. In a small range. It should be understood that the number, shape, and size of the first de-weighting hole 21 and the second de-weighting hole 31 may be set according to actual requirements to better meet actual requirements.

According to the crankshaft assembly 100 for an in-line four-cylinder engine according to an embodiment of the present invention, the axial position of the crankshaft assembly 100 for processing the de-weighting holes is fixed in the designated area, that is, the first balancer 2 and the second balancer 3, so that When the dynamic balance detecting station hits the heavy hole, the distribution range of the drilled heavy hole is small, thereby reducing the difficulty of the tooling design of drilling the heavy hole, simplifying the complexity of the operation of the station, improving the production efficiency, and Reduced production costs.

In one embodiment of the invention, the first weight 2 and the second weight 3 are symmetrical about the central main journal 11, and the first weight 2 and the second weight 3 are respectively disposed adjacent to both ends of the crankshaft 1. 1 and 2, the first balancer 2 and the second balancer 3 are both located below the central axis 12 of the crankshaft 1, and the distance between the first balancer 2 and the central main journal 11 is equal to the second balance 3 The distance from the central main journal 11 when the crankshaft 1 is an in-line four-cylinder four-balanced crankshaft, the distance between the first balancer 2 and the central main journal 11 is greater than the other balance blocks and the center on the left side of the central main journal 11 The distance between the main journals 11, the distance between the second balancer 3 and the central main journal 11 is greater than the distance between the other balance blocks on the right side of the central main journal 11 and the central main journal 11. Thus, by arranging the first balance block 2 and the second balance block 3 adjacent to both ends of the crankshaft 1, respectively, the dynamic balance design requirements of the crankshaft assembly 100 can be better achieved.

Further, the quality of the first predetermined mass is equal to the mass of the second predetermined mass. That is, the added mass on the first balance block 2 is equal to the added mass on the second balance block 3. Of course, the present invention is not limited thereto. In other examples of the present invention, the quality of the first predetermined mass may also be different from the mass of the second predetermined mass, that is, the added mass on the first balancing block 2 is not equal to the first The weight of the second balance block 3 is increased. It is to be understood that the added mass on the first weight 2 and the specific value of the added mass on the second weight 3 can be set according to actual requirements to better meet the actual requirements.

Optionally, the first predetermined mass is integrally formed with the first balance block 2, the second predetermined mass, and the second balance 3, respectively, and the quality of the first predetermined mass may be obtained by the first balance 2 The radius, width or thickness is increased, and the mass of the second predetermined mass can be obtained by increasing the radius, width or thickness of the second weight 3.

In other words, increasing the mass of the first weight 2 can be obtained by increasing the radius of the first weight 2, that is, increasing the length of the first weight 2 in the radial direction of the crankshaft 1, or by increasing the width of the first weight 2 , that is, increasing the opening angle of the first balance block 2 in the circumferential direction of the crankshaft 1, or by increasing the first balance The thickness of the block 2, i.e., the distance between the two surfaces of the first weight 2 on the central axis 12 of the crankshaft 1 is increased.

Further, the crankshaft 1 further includes: at least one third balance block and at least one fourth balance block, at least one third balance block being disposed between the first balance block 2 and the central main journal 11, at least one fourth balance block Between the second weight 3 and the central main journal 11, at least one fourth counterweight and at least one third counterweight are symmetrical about the central main journal 11.

Further, the crankshaft 1 further includes: a third balance block and a fourth balance block, the third balance block is disposed on the crankshaft 1 and located at a side of the first balance block 2 away from the central spindle neck 11, and the fourth balance block is disposed at On the crankshaft 1 and on the side of the second balance block 3 away from the central main journal 11, the fourth balance block and the third balance block are about the center main journal That is, the distance between the third balance block and the central main journal 11 is greater than the distance between the first balance block 2 and the central main journal 11, and the distance between the fourth balance block and the central main journal 11 is greater than the second balance. The distance between the block 3 and the central main journal 11 is, in other words, the first counterweight 2 is located between the third counterweight and the central main journal 11, and the second counterweight 3 is located between the fourth counterweight and the central main journal 11. At this time, the mass of the third balance block and the fourth balance block may be increased, or the quality of the third balance block and the fourth balance block may not be increased.

In summary, when the crankshaft 1 is an in-line four-cylinder eight-balanced crankshaft, the mass of the first balancer 2 and the second balancer 3 may be increased only so that the center of gravity 101 of the crankshaft assembly 100 is offset from the central axis 12 of the crankshaft 1. Then, the heavy holes are respectively drilled on the first balance block 2 and the second balance block 3 such that the center of gravity 101 of the crankshaft assembly 100 coincides with the central axis of the crankshaft.

Or merely increasing the mass of the third balance weight and the fourth balance weight such that the center of gravity 101 of the crankshaft assembly 100 is offset from the central axis 12 of the crankshaft 1, and then the heavy holes are drilled on the third balance weight and the fourth balance weight, respectively, so that Crankshaft assembly

The center of gravity 101 of 100 coincides with the central axis of the crankshaft.

In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "illustrative embodiment", "example", "specific example", or "some examples", etc. Particular features, structures, materials or features described in the examples or examples are included in at least one embodiment or example of the invention. In the present specification, the schematic representation of the above terms does not necessarily mean the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples.

While the embodiments of the present invention have been shown and described, the embodiments of the invention may The scope of the invention is defined by the claims and their equivalents.

Claims

What is claimed is: 1. A method of forming a crankshaft assembly for an in-line four-cylinder engine, comprising: the following steps: S1, adjusting a center of gravity of a crankshaft having a first balance weight and a second balance weight to the crankshaft The central axes coincide;

52. increasing a mass of the first weight and the second weight to bias the center of gravity of the crankshaft assembly away from the central axis of the crankshaft;

53. A heavy hole is drilled into the first balance block and the second balance block, respectively, such that the center of gravity of the crankshaft assembly coincides with the central axis of the crankshaft.

2. The method of forming a crankshaft assembly for an in-line four-cylinder engine according to claim 1, wherein said first balancer and said second balancer are located in said crankshaft in step S1 The same axis

3. The method of forming a crankshaft assembly for an in-line four-cylinder engine according to claim 2, wherein the increase in the mass of the first weight in step S2 is caused by the radius of the first weight, Increase in width or thickness;

The increase in mass of the second weight is obtained by increasing the radius, width or thickness of the second weight.

The method of molding a crankshaft assembly for an in-line four-cylinder engine according to any one of claims 1 to 3, wherein the crankshaft has a central main journal, the first balancer and the first The two balance blocks are symmetrical about the central spindle.

5. The method of forming a crankshaft assembly for an in-line four-cylinder engine according to claim 4, wherein the crankshaft further comprises:

At least one third balance weight, at least one of the third balance blocks being disposed between the first balance block and the central main journal; and

At least one fourth balance block, at least one of the fourth balance blocks being disposed between the second balance block and the central main journal, at least one of the fourth balance block and at least one of the third balance blocks The central spindle is symmetrical.

6. A crankshaft assembly for an in-line four-cylinder engine, comprising:

a crankshaft having a central main journal;

a first balance block, the first balance block is disposed on the crankshaft and located at one side of the central main journal; and a second balance block disposed on the crankshaft and The first balance block is on the axis of the crankshaft Separating from each other, the second balancer is located on the other side of the central main journal, wherein the first balance block is provided with a first predetermined mass and a first de-weighted hole, and the second balance block A second predetermined mass and a second de-weighting hole are provided thereon to coincide the center of gravity of the crankshaft assembly with the central axis of the crankshaft.

7. The crankshaft assembly for an in-line four-cylinder engine according to claim 6, wherein: said first weight and said second weight are symmetric about said central spindle and respectively adjacent said crankshaft Set at both ends.

8. The crankshaft assembly for an in-line four-cylinder engine of claim 7, wherein the mass of the first predetermined mass is equal to the mass of the second predetermined mass.

9. The crankshaft assembly for an in-line four-cylinder engine according to claim 6, wherein a mass of said first predetermined mass is obtained by increasing a radius, a width or a thickness of said first weight;

The mass of the second predetermined mass is obtained by increasing the radius, width or thickness of the second weight.

10. A crankshaft assembly for an in-line four-cylinder engine according to any one of claims 6-9, further comprising: