CN111379620A

CN111379620A - Engine assembling method and engine

Info

Publication number: CN111379620A
Application number: CN201811639052.8A
Authority: CN
Inventors: 渠娜; 刘涛; 刘俊杰; 张树旻; 尹吉; 杨乐; 刘君宇; 钟德华; 姜志永; 李文庆; 李红政
Original assignee: Great Wall Motor Co Ltd
Current assignee: Great Wall Motor Co Ltd
Priority date: 2018-12-29
Filing date: 2018-12-29
Publication date: 2020-07-07

Abstract

The invention discloses an engine and an assembly method thereof. The assembling method of the engine comprises the following steps: the compression ratio adjusting mechanism is used for adjusting the position of the piston in a cylinder hole of the cylinder and comprises an eccentric shaft and a control rod, and the control rod is provided with a first control rod hole and a second control rod hole; the assembling method comprises the following steps: the piston pin penetrates through the piston hole and the first connecting rod hole, the connecting rod pin penetrates through the second connecting rod hole and the first split hole, the control rod pin penetrates through the first control rod hole and the second split hole, and the first split body and the second split body are fixed to install the first split body and the second split body on the connecting rod neck. According to the assembling method of the engine, the assembling precision of the engine can be improved by reasonably arranging the assembling steps.

Description

Engine assembling method and engine

Technical Field

The invention relates to the field of automobiles, in particular to an engine and an assembly method thereof.

Background

The compression ratio of the engine is the ratio of the volume of the cylinder when the piston moves to the bottom dead center to the volume of the combustion chamber when the piston moves to the top dead center. Most of the existing engines are fixed compression ratio engines, and have low fuel combustion efficiency, poor economical efficiency and high emission. With the development of variable compression ratio technology, engines have begun to incorporate compression ratio adjustment mechanisms to vary the compression ratio by varying the combustion chamber volume by, for example, varying the piston top dead center position.

The existing engine assembling method is complex and time-consuming, the motion reliability among parts in the engine is poor, in addition, the number of hinge joints among the parts is large, the inherent mechanism accumulated tolerance is large, the problem of insufficient compression ratio adjusting precision is faced, the assembling precision of a driving shaft of the compression ratio adjusting mechanism is low, the compression ratio adjusting precision is influenced, and the NVH performance of the engine is easily influenced.

Disclosure of Invention

In view of this, the invention aims to provide an engine assembling method which is simple and convenient and has high assembling precision.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a method of assembling an engine, the engine comprising: the piston is suitable for moving in a cylinder bore of the engine, and one end of the piston is provided with a piston bore matched with a piston pin; a crankshaft, a main journal of which is rotatably provided on a cylinder block of the engine; an adjustment element, the adjustment element comprising: the first split body and the second split body are sleeved on a connecting rod neck of the crankshaft, the first split body is provided with a first split body hole matched with the connecting rod pin, and the second split body is provided with a second split body hole matched with the control rod pin; a connecting rod connected between the piston and the adjusting element, a first end of the connecting rod being provided with a first connecting rod hole cooperating with the piston pin, and a second end of the connecting rod being provided with a second connecting rod hole cooperating with the connecting rod pin; a compression ratio adjustment mechanism for adjusting the position of the piston within the cylinder bore, the compression ratio adjustment mechanism comprising: the eccentric shaft and the control rod are connected between the adjusting element and the eccentric shaft, a first end of the control rod is provided with a first control rod hole matched with the control rod pin, and a second end of the control rod is provided with a second control rod hole matched with the eccentric shaft;

the assembly method comprises the following steps:

s1: threading the wrist pin through the piston bore and the first connecting rod bore;

s2: penetrating the connecting rod pin through the second connecting rod hole and the first split hole;

s3: inserting the lever pin through the first lever aperture and the second split aperture;

s4: and fixing the first split body and the second split body so as to install the first split body and the second split body on the connecting rod neck.

According to some embodiments of the invention, the S4 is performed after the S1, the S2 and the S3, and the sequence of the S1, the S2 and the S3 is not limited.

According to some embodiments of the invention, each of the first and second sub-bodies has a "U" -shaped arm, and in the S2, the second end of the link is located in a "U" -shaped space of the "U" -shaped arm of the first sub-body; in S3, the first end of the control rod is located in the U-shaped space of the U-shaped arm of the second segment, and each of the link pin and the control rod pin is in interference fit with the mounting hole on the corresponding U-shaped arm.

In particular, each of said "U" -shaped arms comprises: the forearm mounting hole has been seted up on the forearm, the postbrachium mounting hole has been seted up on the postbrachium, the forearm mounting hole the central axis of postbrachium mounting hole aligns.

Further, each of the link pin and the lever pin has a large diameter end and a small diameter end, an outer diameter of the large diameter end is larger than an outer diameter of the small diameter end, central axes of the large diameter end and the small diameter end are aligned, and the central axis of each of the link pin and the lever pin is aligned with a central axis of a mounting hole corresponding to the "U" -shaped arm.

Further, the big diameter end of each of the connecting rod pin and the control rod pin is in interference fit with the corresponding front arm mounting hole, and the small diameter end of each of the connecting rod pin and the control rod pin is in interference fit with the corresponding rear arm mounting hole.

Optionally, an interference between the small-diameter end and the corresponding rear arm mounting hole is larger than an interference between the large-diameter end and the corresponding front arm mounting hole.

According to some embodiments of the invention, in the S2, the second link hole is clearance-fitted with the small diameter end of the link pin; in S3, the first lever hole is clearance-fitted to the small-diameter end of the lever pin.

Further, in S2 and S3, a side of the rear arm facing away from the front arm is padded on a press-fitting work platform.

Specifically, in S2, the small diameter end of the link pin is first fitted into the second link hole and the rear arm mounting hole of the first division via the front arm mounting hole of the first division, and the large diameter end of the link pin is then fitted into the front arm mounting hole of the first division;

in S3, the small-diameter end of the lever pin is first fitted into the first lever hole and the rear arm mounting hole of the second block through the front arm mounting hole of the second block, and the large-diameter end of the lever pin is then fitted into the front arm mounting hole of the second block.

Optionally, a connecting rod press-fitting boss is arranged at the second end of the connecting rod, the connecting rod press-fitting boss protrudes out of the outer surface of the second end of the connecting rod, so that no gap is left between the second end of the connecting rod and the U-shaped arm of the first split body, and the connecting rod press-fitting boss exceeds the outer contour of the first split body by 3mm-10 mm;

the first end of the control rod is provided with a control rod press-fitting boss, the control rod press-fitting boss protrudes out of the outer surface of the first end of the control rod, so that no gap exists between the first end of the control rod and the U-shaped arm of the second split body, and the control rod press-fitting boss exceeds the outer contour of the second split body by 3-10 mm.

According to some embodiments of the invention, the method of assembling an engine further comprises S5: rotating the first sub-body about the link pin such that the first sub-body is located within a diameter range of the piston, the S5 being before the S4 and after the S1 and the S2.

Further, between S5 and S4, S6 is further included: and putting the assembly of the first split body, the piston and the connecting rod into the cylinder hole top, so that the crankshaft half hole of the first split body surrounds the connecting rod neck.

According to some embodiments of the invention, the eccentric shaft comprises: a drive shaft and an eccentric provided on the drive shaft, the assembling method further comprising S7: and installing the eccentric wheel in the second control rod hole.

Optionally, the S7 is after the S4.

According to some embodiments of the present invention, the crankshaft has a plurality of connecting rods, each connecting rod has an adjusting element disposed thereon, each adjusting element is connected to a connecting rod and a control rod, each control rod has an eccentric disposed in a second control rod hole, and the S7 is followed by S8: and correcting the positions of all the eccentric wheels by using the technological mandrel.

Optionally, the diameter of the process mandrel is smaller than the diameter of the drive shaft, and the difference in diameter is 10mm to 20 mm.

Specifically, the S8 is followed by S9: and gradually penetrating the driving shaft through all the eccentric wheels, and gradually withdrawing the process mandrel.

Further, a driving shaft hole is arranged on the driving shaft, an eccentric wheel hole is arranged on the eccentric wheel, and the step S9 is followed by the step S10: and the transmission pin penetrates through the driving shaft hole and the eccentric wheel hole so as to fix the eccentric wheel on the driving shaft.

Optionally, a drive shaft oil hole is formed in the drive shaft, an eccentric wheel oil hole is formed in the eccentric wheel, the eccentric wheel oil hole is communicated with the drive shaft oil hole, the drive shaft is a hollow drive shaft, a lubricating oil passage is formed in the hollow structure of the drive shaft, and the drive shaft oil hole is communicated with the hollow structure.

Compared with the prior art, the assembling method of the engine has the following advantages:

according to the assembling method of the engine, the assembling precision of the engine can be improved by reasonably arranging the assembling steps; the process mandrel is used, so that the assembly precision and the assembly efficiency can be improved; the combined eccentric shaft can improve the integral structural rigidity and the compression ratio control precision.

Another object of the present invention is to provide an engine assembled by the above assembling method.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is an assembled schematic view of a piston, connecting rod, adjustment element, crankshaft, compression ratio adjustment mechanism;

FIG. 2 is an assembled schematic view of the piston, connecting rod, adjusting element, crankshaft, compression ratio adjustment mechanism, upper cylinder, and lower cylinder;

FIG. 3 is a schematic view of the assembly of the link pin with the link, first split;

FIG. 4 is an assembled view of the linkage, adjustment member, and control lever;

FIG. 5 is a schematic view of a connecting rod;

FIG. 6 is a schematic view of a control lever;

FIG. 7 is a cross-sectional view of the adjustment member;

FIG. 8 is a perspective view of the adjustment member;

FIG. 9 is an assembled view of the piston, the connecting rod and the first split body;

FIG. 10 is a schematic view of an eccentric shaft;

FIG. 11 is a schematic view of an eccentric assembled with a control lever;

FIG. 12 is a schematic view of the assembly of the drive shaft, eccentric and control rod;

FIG. 13 is a schematic view of the installation of the driving shaft and the eccentric wheel in the lower cylinder body;

FIG. 14 is a perspective view of the link pin, lever pin;

FIG. 15 is a cross-sectional view of the link pin, lever pin;

FIG. 16 is a schematic view of the assembly of the link pin with the link and adjustment member;

FIG. 17 is a side sectional view of the adjustment member;

FIG. 18 is a schematic view of one embodiment of an engine assembly method of the present invention.

Description of reference numerals:

the piston 1, the piston hole 11, the connecting rod 2, the first connecting rod hole 21, the second connecting rod hole 22, the connecting rod press-fitting boss 23, the adjusting element 3, the first split body 31, the first split body hole 311, the first bolt hole 313, the first screw hole 314, the first avoidance groove 315, the first crankshaft half hole 316, the first "U" -shaped arm 317, the first front arm 318, the first front arm mounting hole 318a, the first rear arm 319, the first rear arm mounting hole 319a, the second split body 32, the second split body hole 321, the second bolt hole 323, the second screw hole 324, the second avoidance groove 325, the second crankshaft half hole 326, the second "U" -shaped arm 327, the second front arm 328, the second front arm mounting hole 328a, the second rear arm 329, the second rear arm mounting hole 329a, the crankshaft hole 33, the expansion section 34, the adjusting oil passage 35, the first bolt 351, the second bolt 352, the crankshaft 4, the main journal 41, the connecting rod journal 42, the control rod 5, the first control rod hole 51, and the first control rod hole 51, The second control rod hole 52, the control rod press-fitting boss 53, the eccentric shaft 6, the drive shaft 61, the drive shaft oil hole 611, the drive shaft hole 612, the eccentric wheel 62, the eccentric wheel oil hole 621, the eccentric wheel hole 622, the flange 63, the compression ratio adjusting mechanism 7, the upper cylinder 81, the lower cylinder 82, the press-fitting work platform 91, the punch 92, the pad plate 93, the piston pin a, the connecting rod pin B, the connecting rod neck pin C, the control rod pin D, the transmission pin E, the large diameter end 94, the small diameter end 95, and the pin lubricating oil passage 96.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

The present invention will be described in detail with reference to fig. 1 to 18 in conjunction with examples.

Referring to fig. 1 to 2, the engine includes: piston 1, connecting rod 2, adjusting element 3, crankshaft 4 and compression ratio adjusting mechanism 7.

The piston 1 is movable in a cylinder bore of an engine, and as shown in fig. 1, the piston 1 is movable in the cylinder bore in the up-down direction of fig. 1. The main journal 41 of the crankshaft 4 is rotatably provided on a cylinder block of the engine, which includes an upper cylinder block 81 and a lower cylinder block 82, as shown in fig. 2, 12-13, and the crankshaft 4 is provided on a main shaft hole between the upper cylinder block 81 and the lower cylinder block 82. The journals 42 of the crankshaft 4 are offset from the center axis of the main journal 41, and there may be a plurality of journals 42 of the crankshaft 4.

The adjusting element 3 is sleeved on one of the connecting rod necks 42, specifically, a crank hole is formed in the adjusting element 3, the connecting rod neck 42 is located in the crank hole, and the adjusting element 3 and the connecting rod neck 42 can rotate mutually. In some embodiments, a journal pin C or bushing may be disposed between the adjustment element 3 and the journal 42 to reduce wear of the adjustment element 3 and the journal 42 and extend the service life of the engine components.

The connecting rod 2 is connected between the piston 1 and the adjusting element 3, i.e. a first end of the connecting rod 2 is connected to the piston 1 and a second end of the connecting rod 2 is connected to the adjusting element 3. Specifically, the first end of the connecting rod 2 is hinged to the piston 1 through a piston pin A, the second end of the connecting rod 2 is hinged to the adjusting element 3 through a connecting rod pin B, and therefore the connecting rod 2 and the piston 1 can rotate relative to each other, and the connecting rod 2 and the adjusting element 3 can rotate relative to each other, so that when the adjusting element 3 rotates around a connecting rod neck 42 sleeved with the adjusting element 3, the connecting rod 2 can be driven to move, and the piston 1 is driven to move up and down.

The compression ratio adjusting mechanism 7 is used for adjusting the position of the piston 1 in the cylinder hole of the cylinder, so that the position of the piston 1 relative to the cylinder is changed at the top dead center or the bottom dead center, and then the compression ratio is changed. As shown in fig. 1, the compression ratio adjustment mechanism 7 may include: the eccentric shaft 6 and the control rod 5, the control rod 5 is connected between the adjusting element 3 and the eccentric shaft 6, the first end of the control rod 5 is connected with the adjusting element 3, and the second end of the control rod 5 is eccentrically connected with the eccentric shaft 6, so that when the eccentric shaft 6 rotates, the power of the eccentric shaft 6 can be transmitted to the adjusting element 3 through the control rod 5, and the adjusting element 3 rotates around the connecting rod neck 42 sleeved with the adjusting element.

Specifically, when the eccentric shaft 6 rotates, the control rod 5 is pushed to rotate, the control rod 5 pushes the adjusting element 3 to rotate, the adjusting element 3 pushes the connecting rod 2 to rotate, and the connecting rod 2 pushes the piston 1 to move up and down, so that the position of the piston 1 in the cylinder can be adjusted. The piston 1 moves up and down, changing the volume of the combustion chamber and thus the compression ratio. That is, the compression ratio adjustment mechanism 7 may function to change the engine compression ratio. By changing the compression ratio, the load requirements of different engines can be met, and the engines can always work in the optimal working area, so that the dynamic property is improved, the oil consumption is reduced, the emission is reduced, the contradiction between the dynamic property and the economical efficiency and the emission is well solved, and the engines can always work in the optimal oil consumption area.

It should be noted that, in the description of the present invention, the "first end" of the component refers to the upper end in fig. 1, and the "second end" refers to the lower end in fig. 1, but words indicating orientation such as "first end", "second end", "upper", "lower", etc. are for convenience of description only and should not be construed as limiting the present invention.

Referring to fig. 1, the eccentric shaft 6 may include: the driving shaft 61 is rotatably arranged on the cylinder body, the eccentric wheel 62 is sleeved on the driving shaft 61, and the eccentric wheel 62 is fixed relative to the driving shaft 61. A first end of the control rod 5 is articulated with the adjusting element 3 by means of a control rod pin D, and a second end of the control rod 5 is articulated with the drive shaft 61 by means of an eccentric 62, whereby the control rod 5 and the adjusting element 3 and the control rod 5 and the drive shaft 61 are rotatable relative to each other.

The link pin B and the lever pin D are disposed on both sides of the link neck 42 on which the adjustment element 3 is fitted.

The crankshaft 4 is disposed between the piston 1 and the eccentric shaft 6, thereby bringing the crankshaft 4 closer to the piston 1 so that kinetic energy of the piston 1 can be rapidly transferred to the crankshaft 4 upon combustion of fuel, reducing loss of kinetic energy.

Referring to fig. 1, one end of the piston 1 is provided with a piston hole 11 to be engaged with a piston pin a, and referring to fig. 2 to 5, a first end of the connecting rod 2 is provided with a first connecting rod hole 21 to be engaged with the piston pin a, and a second end of the connecting rod 2 is provided with a second connecting rod hole 22 to be engaged with a connecting rod pin B.

The adjustment element 3 may be a stretch-break profile, and the adjustment element 3 comprises: the first sub-body 31 and the second sub-body 32, namely the adjusting element 3, are formed by connecting the first sub-body 31 and the second sub-body 32 in a matching way. The contact surface of the first and

second bodies

31 and 32 is an expansion surface 34, and the expansion surface 34 of the first and

second bodies

31 and 32 has a certain roughness. The first crankshaft half-hole 316 of the first split body 31 and the second crankshaft half-hole 326 of the second split body 32 are sleeved on the connecting rod neck 42 of the crankshaft 4, the first crankshaft half-hole 316 and the second crankshaft half-hole 326 surround the crankshaft hole 33, the first split body 31 is provided with a first split body hole 311 matched with the connecting rod pin B, and the second split body 32 is provided with a second split body hole 321 matched with the control rod pin D.

Referring to fig. 2, 4 and 6, a first end of the lever 5 is provided with a first lever hole 51 engaged with the lever pin D, and a second end of the lever 5 is provided with a second lever hole 52 engaged with the eccentric shaft 6.

The assembling method of the engine according to the embodiment of the invention comprises the following steps:

s1: a piston pin A penetrates through the piston hole 11 and the first connecting rod hole 21, so that the first end of the connecting rod 2 and the piston 1 can be connected into a piston connecting rod assembly through the piston pin A, and the piston 1 and the connecting rod 2 are connected in an articulated manner, as shown in FIG. 9;

s2: the link pin B is inserted through the second link hole 22 and the first sub-body hole 311, thereby achieving the hinge connection of the link 2 and the first sub-body 31, as shown in fig. 3-4, 9;

s3: the control rod pin D is inserted into the first control rod hole 51 and the second split hole 321, thereby realizing the hinged connection of the control rod 5 and the second split 32, as shown in fig. 4;

s4: the first and

second bodies

31 and 32 are fixed to each other to mount the first and

second bodies

31 and 32 on the journals 42, thereby achieving the hinge connection of the adjustment element 3 to the corresponding journal 42, as shown in fig. 2.

According to the assembling method of the engine provided by the embodiment of the invention, the assembling precision of the engine can be improved by reasonably arranging the assembling steps.

In some embodiments of the invention, S4 is performed after S1, S2, S3, and the order of S1, S2, S3 is not limited. For example, in an alternative embodiment, the adjustment elements 3 may be assembled in the sequence of S1, S2, S3, S4 by connecting the piston 1 to the connecting rod 2, connecting the connecting rod 2 to the first body 31, connecting the control rod 5 to the second body 32, and fixing the first body 31 to the second body 32 such that the adjustment elements 3 are fitted over the corresponding connecting rod necks 42. In another alternative embodiment, the assembly can be performed in the sequence of S2, S1, S3, S4, in which the connecting rod 2 is connected to the first sub-body 31, the piston 1 is connected to the connecting rod 2, the control rod 5 is connected to the second sub-body 32, and finally the first sub-body 31 and the second sub-body 32 are fixed, so that the adjusting element 3 is sleeved on the corresponding connecting rod neck 42. There are many sequences of steps S1, S2, S3 and S4, such as S2, S3, S1 and S4, or S3, S2, S1 and S4, which are not listed here.

Preferably, step S1 is performed after step S2, so that the link 2 is connected to the first sub-body 31 by using the link pin B, which is convenient to operate.

Referring to fig. 4 and 8, each of the first and

second division bodies

31 and 32 has a "U" -shaped arm, and in S2, the second end of the link 2 is located in the "U" -shaped space of the "U" -shaped arm of the first division body 31; in S3, the first end of the control lever 5 is located in the "U" shaped space of the "U" shaped arm of the second split body 32, and each of the link pin B and the control lever pin D is interference-fitted with the mounting hole on the corresponding "U" shaped arm.

In particular, each "U" shaped arm comprises: forearm and postbrachium have seted up the forearm mounting hole on the forearm, have seted up the postbrachium mounting hole on the postbrachium, and the mounting hole on "U" shape arm is forearm mounting hole and postbrachium mounting hole promptly, and the central axis of forearm mounting hole, postbrachium mounting hole aligns.

Further, referring to fig. 14, in order to avoid press-fitting deformation, the link pin B and the lever pin D are stepped pins, that is, each of the link pin B and the lever pin D has a large diameter end 94 and a small diameter end 95, the outer diameter of the large diameter end 94 is larger than that of the small diameter end 95, the central axes of the large diameter end 94 and the small diameter end 95 are aligned, and the central axis of each of the link pin B and the lever pin D is aligned with the central axis of the mounting hole of the corresponding "U" -shaped arm, so that the link pin B and the lever pin D can be conveniently mounted in the mounting hole of the corresponding "U" -shaped arm.

Alternatively, the difference between the diameters of the large diameter end 94 and the small diameter end 95 is 0.1mm to 0.6mm, such as 0.2mm or 0.4 mm. The large-diameter end 94 and the small-diameter end 95 are connected through arcs, so that stress of the connecting rod pin B and the control rod pin D during press fitting can be removed, and smooth press fitting is guaranteed. The arc diameters of the large-diameter end 94 and the small-diameter end 95 may be 0.4mm to 1mm, for example, 0.6mm or 0.8 mm.

Specifically, referring to fig. 8, first body 31 has a first "U" shaped arm 317, first "U" shaped arm 317 including: first front arm 318 and first rear arm 319, first front arm mounting hole 318a has been seted up on first front arm 318, first rear arm 319 has been seted up first rear arm mounting hole 319a, and the central axis of first front arm mounting hole 318a, first rear arm mounting hole 319a aligns, is convenient for install link pin B in first front arm mounting hole 318a, first rear arm mounting hole 319 a.

The second section 32 has a second "U" shaped arm 327, the second "U" shaped arm 327 comprising: a second front arm 328 and a second rear arm 329, wherein the second front arm 328 has a second front arm mounting hole 328a, the second rear arm 329 has a second rear arm mounting hole 329a, and the central axes of the second front arm mounting hole 328a and the second rear arm mounting hole 329a are aligned, so that the control rod pin D can be conveniently mounted in the second front arm mounting hole 328a and the second rear arm mounting hole 329 a.

In S2, the second end of the link 2 is located in the "U" space of the first "U" shaped arm 317; in S3, the first end of the control lever 5 is located in the "U" shaped space of the second "U" shaped arm 327.

Further, the large diameter end 94 of each of the link pin B and the lever pin D is interference fit with the corresponding front arm mounting hole, and the small diameter end 95 of each of the link pin B and the lever pin D is interference fit with the corresponding rear arm mounting hole.

The interference between the small diameter end 95 and the corresponding rear arm mounting hole is not equal to the interference between the large diameter end 94 and the corresponding front arm mounting hole. Alternatively, the interference between the small diameter end 95 and the corresponding rear arm mounting hole is larger than the interference between the large diameter end 94 and the corresponding front arm mounting hole, so that the deformation of the front arm during press fitting can be reduced. Specifically, when the link pin B or the control lever pin D is press-fitted, the interference between the large-diameter end 94 and the corresponding forearm mounting hole is reduced, and the press-fitting force between the large-diameter end 94 and the corresponding forearm mounting hole during press-fitting can be weakened, so that the deformation of the corresponding forearm can be reduced. The rear arm of the U-shaped arm is suitable for being in contact with the press-fitting working platform 91, so that the magnitude of interference of the fit between the small-diameter end 95 and the rear arm mounting hole is increased, the press-fitting work safety can be guaranteed, and the deformation of the rear arm of the U-shaped arm can be prevented.

For example, the interference between the small diameter end 95 and the corresponding rear arm mounting hole may be 0.013mm to 0.087mm, and the interference between the large diameter end 94 and the corresponding front arm mounting hole may be 0.006mm to 0.080 mm.

Specifically, the large diameter end 94 of link pin B is interference fit with the first front arm mounting hole 318a, and the small diameter end 95 of link pin B is interference fit with the first rear arm mounting hole 319 a. The interference between the small diameter end 95 of link pin B and the first rear arm mounting hole 319a is greater than the interference between the large diameter end 94 of link pin B and the first front arm mounting hole 318 a.

The thickness of the large diameter end 94 of the link pin B is smaller than the thickness of the first front arm 318, so that the thickness of the large diameter end 94 and the first front arm mounting hole 318a is reduced, and the possibility of deformation of the first front arm 318 can be reduced.

Likewise, the large diameter end 94 of the lever pins D is an interference fit with the second forward arm mounting hole 328a, and the small diameter end 95 of each of the lever pins D is an interference fit with the second rearward arm mounting hole 329 a. The interference between the small diameter end 95 of the lever pin D and the second rear arm mounting hole 329a is greater than the interference between the large diameter end 94 of the lever pin D and the second front arm mounting hole 328 a.

The thickness of the large diameter end 94 of the lever pin D is less than the thickness of the second forearm 328, thereby reducing the thickness of the engagement of the large diameter end 94 with the second forearm mounting hole 328a and reducing the likelihood of deformation of the second forearm 328.

In S2, the second link hole 22 is in clearance fit with the small-diameter end 95 of the link pin B, so that abrasion of the second link hole 22 and the link pin B due to press-fitting deformation of the first "U" -shaped arm 317 can be reduced, and the amount of clearance may be 0.005mm to 0.060mm, for example, 0.010mm, 0.020mm, 0.030mm, or 0.040 mm; in S3, the first lever hole 51 is in clearance fit with the small diameter end 95 of the lever pin D, and the amount of clearance may be 0.005mm to 0.060mm, for example, 0.010mm, 0.020mm, 0.030mm, or 0.040mm, to reduce the wear of the first lever hole 51 and the lever pin D due to press-fitting deformation of the second "U" -shaped arm 327.

Referring now to fig. 15-17, lubrication between the adjustment element 3 and the link pin B is described, and lubrication between the adjustment element 3 and the control link pin D is similar and will not be described again.

The connecting rod pin B is provided with a pin lubricating oil passage 96, the first split body 31 of the adjusting element 3 is provided with an adjusting oil passage 35, the pin lubricating oil passage 96 is communicated with the adjusting oil passage 35, and lubricating oil in the crankshaft hole 33 can enter the pin lubricating oil passage 96 through the adjusting oil passage 35 so as to lubricate the positions of the connecting rod pin B, the second connecting rod hole 22 and the first split body hole 311 and reduce the abrasion of parts at the hinged part of the connecting rod 2 and the first split body 31.

Specifically, as shown in fig. 7 to 8, the first and second divided

bodies

31 and 32 are fixed by a fastener, which may include: first and

second bolts

351 and 352, the first and

second bolts

351 and 352 being disposed at both sides of the crank hole 33, and the first and

second bolts

351 and 352 being oriented in opposite directions, thereby fixing the first and

second segments

31 and 32 together.

By mounting the first bolt 351 and the second bolt 352 in opposite directions, not only the connection strength between the first component 31 and the second component 32 can be improved, but also the strength of the bolts themselves can be improved, in the conventional bolts arranged in the same direction, one of the two bolts can be overlapped with the position of the first component hole 311 or the second component hole 321, so that the bolts cannot be mounted, therefore, in order to solve the above problems, the bolts arranged in the same direction need to be forced to increase the distance from the first component hole 311 to the crankshaft hole 33 or the distance from the second component hole 321 to the crankshaft hole 33, so as to ensure that the bolts can be mounted smoothly, but this in turn can be disadvantageous for realizing light weight of the adjusting element 3.

Therefore, by reversing the orientation of the first bolt 351 and the second bolt 352, not only can the connection reliability of the first and second sub-bodies 31 and 32 be ensured to be high, but also the mass and volume of the adjustment element 3 can be ensured to be small, thereby contributing to the weight reduction of the engine.

The crankshaft 4 must be set up using a tool to simultaneously tighten the first bolt 351 and the second bolt 352 in opposite directions, limited by the bolt-reversal arrangement position of the adjusting element 3. The first bolt 351 and the second bolt 352 are simultaneously screwed down, so that the stress of the adjusting element 3 is uniform, the bearing bush is uniformly deformed, and the bearing holding problem is prevented.

Preferably, the strength grade of the first bolt 351 and the second bolt 352 is not lower than 14.9. In the embodiment, when the engine is at the maximum explosion pressure, the force applied to the first and second split holes 311 and 321 tends to pre-separate the first and

second split bodies

31 and 32, and specifically, the force applied to the first and second split holes 311 and 321 is decomposed to the fastening position of the first and

second bolts

351 and 352, so that the first and second split holes 311 and 321 are subjected to a large pulling force, and therefore, in order to ensure that the first and

second split bodies

31 and 32 are not separated, the pretightening force of the first and second bolts 352 needs to be increased, but since the space reserved for installing the first and

second bolts

351 and 352 by the adjusting element 3 is limited, the specifications of the first and

second bolts

351 and 352 cannot be increased, and therefore, by selecting the strength grade of the first and

second bolts

351 and 352 which is larger, specifically, the strength levels of the first and

second bolts

351 and 352 are not lower than 14.9, so that the adjustment element 3 can be fastened to prevent the first and second sub-bodies 31 and 32 from being separated, thereby ensuring the normal operation of the engine.

Further, as shown in fig. 7, the first body 31 is provided with a first bolt hole 313 and a first screw hole 314, and the first bolt hole 313 is parallel to but not coincident with the axis of the first screw hole 314, specifically, the first bolt hole 313 is provided to provide an entrance/exit for the first bolt 351, and the first screw hole 314 is provided to provide a support for fixing the second bolt 352. Second body 32 is provided with second bolt hole 323 and second threaded hole 324, second bolt hole 323 is parallel to the axis of second threaded hole 324 but not coincident with it, specifically, through second bolt hole 323, second bolt 352 is provided with access, through second threaded hole 324, for first bolt 351 is provided with support.

The axes of the first bolt 351 and the second bolt 352 are orthogonal to the bore of the cylinder, in a specific embodiment, when the first component 31 and the second component 32 are connected in a matching manner, the friction force at the connection part between the first component 31 and the second component 32 is large due to the fact that the roughness of the contact surface (namely the expansion surface 40) of the first component 31 and the second component 32 is large, and the problem that when an engine is arranged, the separation surface of the adjusting element 3 has shear force due to the fact that the adjusting element 3 is not arranged at the position where the engine is stressed at the maximum and the axis of the bolt is parallel to the bore of the cylinder, and therefore the bolt is prone to break can be solved. The adjusting element 3 is designed to be of a quadrilateral structure, so that the stress condition can be improved.

Optionally, the first bolts 351 and the second bolts 352 are flange bolts. The heads of the first bolt 351 and the second bolt 352 are flanges, and the diameters of the flanges are larger, so that the bearing stress surfaces of the bolts can be increased.

Optionally, the outer surface of the adjusting element 3 is a blank surface, which can simplify the processing procedure of the adjusting element 3 and is beneficial to reducing the cost of the adjusting element 3.

Specifically, referring to fig. 1-2, 4, and 7, the connecting rod 2 is hinged to the adjusting element 3 at a first split hole 311, the control rod 5 is hinged to the adjusting element 3 at a second split hole 321, the first split 31 is provided with a first avoidance slot 315, the first avoidance slot 315 is used for avoiding a second end of the connecting rod 2, the second split 32 is provided with a second avoidance slot 325, and the second avoidance slot 325 is used for avoiding a first end of the control rod 5, so as to ensure that the adjusting element 3 can avoid the movement tracks of the connecting rod 2 and the control rod 5 when the engine operates, and further ensure that the engine can operate normally.

Further, the boundary lines of the first avoidance groove 315 and the second avoidance groove 325 are both two straight lines, and one of the two straight lines is provided with an arc avoidance section, so that the motion trajectory of the connecting rod 2 or the control rod 5 can be further avoided, and the improvement of the reliability of the normal operation of the engine is facilitated.

Further, in S2 and S3, the side of the rear arm facing away from the front arm is padded on the press-fitting work platform 91. For example, referring to fig. 3, in S2, the side of the first rear arm 319 facing away from the first front arm 318 is laid on the press-fitting work platform 91. In S3, the side of the second rear arm 329 facing away from the second front arm 328 is laid on the press-fitting work platform 91.

Specifically, in S2, small diameter end 95 of link pin B is fitted into second link hole 22 and first rear arm mounting hole 319a through first front arm mounting hole 318a of first split body 31, large diameter end 94 of link pin B is fitted into first front arm mounting hole 318a, and the first end of link 2 is seated on backing plate 93, facilitating the assembly of link pin B. The use of punch 92 to apply pressure to link 2 facilitates the installation of large diameter end 94 of link pin B into first forearm mounting hole 318 a.

In S3, the small-diameter end 95 of the lever pin D is fitted into the first lever hole 51 and the second rear-arm mounting hole 329a through the second front-arm mounting hole 328a of the second split body 32, the large-diameter end 94 of the lever pin D is fitted into the second front-arm mounting hole 328a, and the second end of the lever 5 is seated on the shim plate 93, facilitating the assembly of the lever pin D. The use of the punch 92 to apply pressure to the lever 5 facilitates the installation of the large diameter end 94 of the lever pin D into the second forearm mounting hole 328 a.

Alternatively, as shown in fig. 3 to 5, the second end of the connecting rod 2 is provided with a connecting rod press-fitting boss 23, and the connecting rod press-fitting boss 23 protrudes out of the outer surface of the second end of the connecting rod 2, so that there is no gap between the second end of the connecting rod 2 and the first "U" -shaped arm 317 of the first sub-body 31, that is, the total thickness of the second end of the connecting rod 2 is equal to the distance between the first front arm 318 and the first rear arm 319, so that the relative movement between the connecting rod 2 and the first sub-body 31 during the press-fitting process is reduced, and the connecting rod press-fitting boss 23 exceeds the outer contour of the first sub-body 31 by 3mm to 10 mm;

referring to fig. 4 and 6, the first end of the control rod 5 is provided with a control rod press-fitting boss 53, and the control rod press-fitting boss 53 protrudes from the outer surface of the first end of the control rod 5, so that there is no gap between the first end of the control rod 5 and the second U-shaped arm 327 of the second block 32, that is, the total thickness of the first end of the control rod 5 is equal to the distance between the second front arm 328 and the second rear arm 329, thereby reducing the relative movement between the control rod 5 and the second block 32 during the press-fitting process, and the control rod press-fitting boss 53 exceeds the outer contour of the second block 32 by 3mm to 10mm, for example, 5mm or 8 mm.

Referring to fig. 9, the engine assembling method further includes S5: the first sub-body 31 is rotated about the connecting rod pin B so that the first sub-body 31 is located within the diameter range of the piston 1, and in a specific embodiment, the first sub-body 31 may be maintained at a position within the diameter range of the piston 1 using an elastic band.

Optionally, S5 is before S4 and after S1 and S2.

Further, between S5 and S4, S6 is further included: the assembly of the first body 31, piston 1, connecting rod 2 is placed from the cylinder bore top so that the crankshaft half bore of the first body 31 embraces the connecting rod neck 42. That is, after the connecting rod 2, the piston 1, and the first divided body 31 are connected, the first divided body 31 is adjusted to the state shown in fig. 9 such that the position of the first divided body 31 is within the diameter range of the piston 1, and the first divided body 31 is inserted from the cylinder bore top portion while being wrapped with a tool (e.g., an elastic band). After the cylinder hole is put into the bottom dead center, the first sub-body 31 is adjusted to the position of the corresponding connecting rod neck 42. At this point, the pre-assembled control rod 5 and the second split body 32 are placed in the position of the connecting rod neck 42.

Referring to fig. 1 to 2 and 10 to 13, the eccentric shaft 6 includes: the driving shaft 61 and the eccentric 62, the eccentric 62 being disposed on the driving shaft 61, the assembling method further comprising S7: the eccentric 62 is mounted in the second lever bore 52 as shown in fig. 11.

Optionally, S7 is after S4. In other words, the eccentric 62 can be mounted in the second control rod bore 52 after the piston 1, the connecting rod 2, the adjusting element 3, the crankshaft 4 and the control rod 5 have been assembled.

The crankshaft 4 has a plurality of connecting rods 42, each connecting rod 42 is provided with an adjusting element 3, each adjusting element 3 is connected with the connecting rod 2 and the control rod 5, each control rod 5 is provided with an eccentric wheel 62 in the second control rod hole 52, and as shown in fig. 11, S7 is followed by S8: the position of all the eccentrics 62 is corrected using a technological mandrel so that the centers of the eccentrics 62 are substantially on the same line. Referring to fig. 11-12, the number of eccentrics 62 is four. The process mandrel is inserted into the bearing holes of the four eccentrics 62 and the lower cylinder 82, and after the process mandrel is inserted, the center positions of all the eccentrics 62 are substantially the same in the cylinder, thereby completing the position correction of the eccentrics 62. By using the process mandrel, the assembly precision and the assembly efficiency can be improved.

Optionally, the diameter of the process mandrel is smaller than the diameter of the drive shaft 61, so that the process mandrel makes initial adjustments to the position of all the eccentrics 62 and facilitates the withdrawal of the process mandrel from the eccentrics 62. Optionally, the difference in diameter between the process mandrel and the drive shaft 61 is 10mm to 20 mm. The length of the process mandrel is equal to the length of the drive shaft 61.

Specifically, referring to fig. 12, S8 is followed by S9: the drive shaft 61 is progressively threaded through all the eccentrics 62 and the process mandrel is progressively withdrawn. After the assembly of the drive shaft 61 with the eccentric 62 is completed, as shown in fig. 10. The left end of the driving shaft 61 is provided with a flange 63, the flange 63 is adapted to be fixed with the lower cylinder 82, and the driving shaft 61 is rotatable with respect to the flange 63, thereby supporting the driving shaft 61 on the lower cylinder 82. After the flange 63 and the driving shaft 61 are assembled in advance, the driving shaft 61 passes through the bearing hole of the lower cylinder 82 and the eccentric wheel 62, and the process mandrel is gradually withdrawn.

Further, referring to fig. 10, 12-13, the driving shaft 61 is provided with a driving shaft hole 612, the eccentric wheel 62 is provided with an eccentric wheel hole 622, and S10 follows S9: drive pin E passes through drive shaft bore 612 and eccentric bore 622 to secure eccentric 62 to drive shaft 61.

After the assembly of the driving shaft 61 is completed, the liquid nitrogen cools the driving pin E, and the cooled driving pin E is easily fitted into the eccentric wheel 62, thereby completing the assembly of the combined eccentric shaft 6. The combined eccentric shaft 6 is adopted, so that the integral structural rigidity can be improved, and the compression ratio control precision can be improved.

During the assembly of the eccentric shaft 62, the drive shaft hole 612 and the eccentric hole 622 are in the same direction during the assembly of the eccentric shaft 6. The eccentric wheel 62 is centered with respect to the driving shaft 61 by visual inspection, and the relative position of the eccentric wheel 62 and the driving shaft 61 is completely fixed by using a driving pin E, which serves to fix the relative position of the eccentric wheel 62 and the driving shaft 61.

Optionally, a driving shaft oil hole 611 is formed in the driving shaft 61, an eccentric wheel oil hole 621 is formed in the eccentric wheel 62, the eccentric wheel oil hole 621 is communicated with the driving shaft oil hole 611, after the transmission pin E is assembled, the eccentric wheel oil hole 621 can be opposite to the driving shaft oil hole 611, and the transmission pin E also plays a role in positioning the oil hole. The driving shaft 61 is a hollow driving shaft, a lubricating oil passage is formed by the hollow structure of the driving shaft 61, the driving shaft oil hole 611 is communicated with the hollow structure, and lubricating oil enters the driving shaft oil hole 611 through the hollow structure, further enters the eccentric wheel oil hole 621 and finally enters the eccentric wheel 62 to lubricate the control rod 5.

Fig. 18 shows an embodiment of the engine assembling method according to the present invention, which is performed sequentially according to the sequence of S2, S1, S5, S6, S3, S4, S7, S8, S9 and S10, although in some embodiments not shown, the sequence of S1, S2 and S3 may be changed and is not listed here.

An engine according to an embodiment of another aspect of the present invention is assembled using the method of assembling an engine according to the above embodiment.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. A method of assembling an engine, said engine comprising:

the piston (1) is suitable for moving in a cylinder bore of the engine, and one end of the piston (1) is provided with a piston bore (11) matched with a piston pin (A);

a crankshaft (4), a main journal (41) of the crankshaft (4) being rotatably provided on a cylinder block of the engine;

an adjustment element (3), the adjustment element (3) comprising: the crankshaft assembly comprises a first split body (31) and a second split body (32), wherein the first split body (31) and the second split body (32) are sleeved on a connecting rod neck (42) of the crankshaft (4), the first split body (31) is provided with a first split body hole (311) matched with a connecting rod pin (B), and the second split body (32) is provided with a second split body hole (321) matched with a control rod pin (D);

a connecting rod (2), said connecting rod (2) being connected between said piston (1) and said adjusting element (3), a first end of said connecting rod (2) being provided with a first connecting rod hole (21) cooperating with said piston pin (A), a second end of said connecting rod (2) being provided with a second connecting rod hole (22) cooperating with said connecting rod pin (B);

a compression ratio adjustment mechanism (7), the compression ratio adjustment mechanism (7) being for adjusting a position of the piston (1) within the cylinder bore, the compression ratio adjustment mechanism (7) comprising: an eccentric shaft (6) and a control rod (5), the control rod (5) being connected between the adjusting element (3) and the eccentric shaft (6), a first end of the control rod (5) being provided with a first control rod hole (51) cooperating with the control rod pin (D), and a second end of the control rod (5) being provided with a second control rod hole (52) cooperating with the eccentric shaft (6);

the assembly method comprises the following steps:

s1: -threading the piston pin (a) through the piston bore (11) and the first connecting rod bore (21);

s2: penetrating the connecting rod pin (B) through the second connecting rod hole (22) and the first split hole (311);

s3: -passing said lever pin (D) through said first lever hole (51) and said second split hole (321);

s4: and fixing the first split body (31) and the second split body (32) to install the first split body (31) and the second split body (32) on the connecting rod neck (42).

2. The engine assembling method according to claim 1, wherein said S4 is performed after said S1, said S2 and said S3, and the sequence of said S1, said S2 and said S3 is not limited.

3. The assembling method of the engine according to claim 1, characterized in that each of the first and second divided bodies (31, 32) has a "U" shaped arm, and in the S2, the second end of the connecting rod (2) is located in a "U" shaped space of the "U" shaped arm of the first divided body (31); in S3, the first end of the control lever (5) is located in the U-shaped space of the U-shaped arm of the second split body (32), and each of the link pin (B) and the control lever pin (D) is interference-fitted with the mounting hole on the corresponding U-shaped arm.

4. A method of assembling an engine according to claim 3, wherein each of said "U" -shaped arms comprises: the forearm mounting hole has been seted up on the forearm, the postbrachium mounting hole has been seted up on the postbrachium, the forearm mounting hole the central axis of postbrachium mounting hole aligns.

5. The engine assembling method according to claim 4, wherein each of the link pin (B) and the control lever pin (D) has a large diameter end (94) and a small diameter end (95), an outer diameter of the large diameter end (94) is larger than an outer diameter of the small diameter end (95), central axes of the large diameter end (94) and the small diameter end (95) are aligned, and the central axis of each of the link pin (B) and the control lever pin (D) is aligned with a central axis of a mounting hole of the corresponding "U" -shaped arm.

6. The method of assembling an engine according to claim 5, wherein the large-diameter end (94) of each of the link pin (B) and the control lever pin (D) is interference-fitted with the corresponding front arm mounting hole, and the small-diameter end (95) of each of the link pin (B) and the control lever pin (D) is interference-fitted with the corresponding rear arm mounting hole.

7. The engine assembly method according to claim 6, characterized in that the interference between the small diameter end (95) and the corresponding rear arm mounting hole is larger than the interference between the large diameter end (94) and the corresponding front arm mounting hole.

8. The assembling method of the engine according to claim 7, wherein in the S2, the second link hole (22) is clearance-fitted with a small-diameter end (95) of the link pin (B); in S3, the first lever hole (51) is clearance-fitted to the small-diameter end (95) of the lever pin (D).

9. The engine assembling method according to claim 8, wherein in said S2 and said S3, a side of said rear arm facing away from said front arm is padded on a press-fitting work platform (91).

10. The engine assembling method according to claim 9, wherein in S2, the small diameter end (95) of the link pin (B) is fitted into the second link hole (22) and the rear arm mounting hole of the first division body (31) through the front arm mounting hole of the first division body (31), and the large diameter end (94) of the link pin (B) is fitted into the front arm mounting hole of the first division body (31);

in S3, the small-diameter end (95) of the lever pin (D) is fitted into the first lever hole (51) and the rear-arm mounting hole of the second block (32) through the front-arm mounting hole of the second block (32), and the large-diameter end (94) of the lever pin (D) is fitted into the front-arm mounting hole of the second block (32).

11. The assembling method of the engine according to the claim 3, characterized in that the second end of the connecting rod (2) is provided with a connecting rod press-fitting boss (23), the connecting rod press-fitting boss (23) protrudes the outer surface of the second end of the connecting rod (2) so that no gap is left between the second end of the connecting rod (2) and the U-shaped arm of the first split body (31), and the connecting rod press-fitting boss (23) exceeds the outer contour of the first split body (31) by 3mm-10 mm;

the first end of the control rod (5) is provided with a control rod press-fitting boss (53), the control rod press-fitting boss (53) protrudes out of the outer surface of the first end of the control rod (5), so that no gap exists between the first end of the control rod (5) and the U-shaped arm of the second sub-body (32), and the control rod press-fitting boss (53) exceeds the outer contour of the second sub-body (32) by 3-10 mm.

12. The engine assembling method according to claim 1, further comprising S5: rotating the first division body (31) around the link pin (B) such that the first division body (31) is located within a diameter range of the piston (1), the S5 being before the S4 and after the S1 and the S2.

13. The method of assembling an engine according to claim 12, further comprising, between S5 and S4, S6: and putting the assembly of the first split body (31), the piston (1) and the connecting rod (2) from the top of a cylinder hole so that a crankshaft (4) of the first split body (31) semi-hole encircles the connecting rod neck (42).

14. The method of assembling an engine according to claim 1, wherein the eccentric shaft (6) comprises: a drive shaft (61) and an eccentric (62), the eccentric (62) being disposed on the drive shaft (61), the assembling method further comprising S7: mounting the eccentric (62) within the second control rod bore (52).

15. The method of assembling an engine according to claim 14, wherein said S7 is subsequent to said S4.

16. The method of assembling an engine according to claim 14, wherein the crankshaft (4) has a plurality of connecting journals (42), each connecting journal (42) having an adjusting element (3), each adjusting element (3) being connected to a connecting rod (2) and a control rod (5), each control rod (5) having an eccentric (62) disposed in the second control rod hole (52), and S8 following S7: the positions of all eccentrics (62) are corrected using a technological mandrel.

17. Method of assembling an engine according to claim 16, characterized in that the diameter of the process mandrel is smaller than the diameter of the drive shaft (61) and the difference in diameter is 10-20 mm.

18. The method of assembling an engine of claim 16, further comprising, after said S8, S9: and gradually penetrating the driving shaft (61) through all the eccentric wheels (62), and gradually withdrawing the process mandrel.

19. The assembling method of the engine according to claim 18, wherein the driving shaft (61) is provided with a driving shaft hole (612), the eccentric wheel (62) is provided with an eccentric wheel hole (622), and the step S9 is followed by the step S10: a drive pin (E) is inserted through the drive shaft hole (612) and the eccentric wheel hole (622) to fix the eccentric wheel (62) to the drive shaft (61).

20. The assembling method of the engine according to claim 19, wherein a driving shaft oil hole (611) is formed in the driving shaft (61), an eccentric wheel oil hole (621) is formed in the eccentric wheel (62), the eccentric wheel oil hole (621) communicates with the driving shaft oil hole (611), the driving shaft (61) is a hollow driving shaft (61), a hollow structure of the driving shaft (61) forms a lubricating oil passage, and the driving shaft oil hole (611) communicates with the hollow structure.

21. An engine assembled using the method of assembling an engine according to any one of claims 1 to 20.