WO2020259371A1 - Lower connecting rod, and engine having same - Google Patents

Abstract

A lower connecting rod, and an engine having same. The lower connecting rod (3) is provided with a central hole (33) matched with a crankshaft (4), and the lower connecting rod (3) comprises: an upper connecting rod portion (31) and a control connecting rod portion (32); the upper connecting rod portion (31) is connected to the control connecting rod portion (32), at least one connection point is a rotating connection point, and the axis of rotation of the rotating connection point is parallel to the axis of the central hole (33).

Description

Lower connecting rod, engine with it

This application is required to be submitted to the Chinese Patent Office on June 28, 2019, with the application number of 201910580253.3, and the invention titled "Lower connecting rod and its engine", and on June 28, 2019, with the application number of 201910578737.4, the priority of the Chinese patent application with the title of "lower connecting rod and its engine", the entire content of which is incorporated into this application by reference.

Technical field

The present invention relates to the field of automobiles, and in particular, to a lower connecting rod and an engine having the same.

Background technique

The compression ratio of the engine refers to the ratio of the cylinder volume when the piston moves to bottom dead center to the volume of the combustion chamber when the piston moves to top dead center. Most of the existing engines are fixed compression ratio engines with low fuel combustion efficiency, poor economy, and high emissions. With the development of variable compression ratio technology, the engine began to increase the compression ratio adjustment mechanism, by changing the piston top dead center position and other ways to change the volume of the combustion chamber, thereby changing the compression ratio to meet the needs of different engine loads, so that the engine always works at the maximum A good working area, which not only improves the dynamics, reduces fuel consumption, but also reduces emissions, and solves the contradiction between dynamics, economy, and emissions.

At present, the typical structure for changing the top dead center position of the engine piston is a multi-link mechanism. The lower connecting rod is connected with the connecting rod neck of the crankshaft. However, when the engine is working, the lower connecting rod receives the greatest force due to inertial force. The structural design requirements are strict and the assembly is complicated.

Summary of the invention

In view of this, the present invention aims to propose a lower connecting rod to optimize the assembly process of the lower connecting rod.

In order to achieve the above objective, the technical solution of the present invention is achieved as follows:

A lower connecting rod is provided with a central hole matched with a crankshaft. The lower connecting rod includes: an upper connecting rod part, a control connecting rod part, the upper connecting rod part and the control connecting rod At least one connection point is a rotation connection point, and the rotation axis of the rotation connection point is parallel to the axis of the central hole.

Compared with the prior art, the lower connecting rod of the present invention is less difficult to assemble, and the upper connecting rod part and the control connecting rod part are rotationally connected by a hinge pin, which is beneficial to improving the force of the lower connecting rod.

Another object of the present invention is to provide an engine, the engine comprising: a piston adapted to move in the cylinder of the engine; a crankshaft, the main journal of the crankshaft is rotatably arranged on the engine On the cylinder; the above-mentioned lower connecting rod, the lower connecting rod is sleeved on the connecting rod neck of the crankshaft; the upper connecting rod, the upper connecting rod is connected between the piston and the lower connecting rod; A compression ratio adjustment mechanism, the compression ratio adjustment mechanism is used to adjust the position of the piston in the cylinder, and the compression ratio adjustment mechanism includes a control link, the control link is hinged with the lower link.

Compared with the prior art, the engine compression ratio adjusting mechanism of the present invention has high working reliability and can improve the force of the lower connecting rod.

The above description is only an overview of the technical solution of the present invention. In order to understand the technical means of the present invention more clearly, it can be implemented in accordance with the content of the description, and in order to make the above and other objectives, features and advantages of the present invention more obvious and understandable. In the following, specific embodiments of the present invention are specifically cited.

Description of the drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art.

Figure 1 is an assembly diagram of the piston, upper connecting rod, lower connecting rod, crankshaft, and compression ratio adjusting mechanism;

Figure 2 is an assembly diagram of the piston, upper connecting rod, lower connecting rod, and compression ratio adjusting mechanism;

Figure 3 is an exploded schematic diagram of the upper connecting rod, the lower connecting rod, the crankshaft, the control connecting rod, and the bearing bush;

Figure 4 is a schematic diagram of the assembly of the upper connecting rod, the lower connecting rod, the connecting rod neck, the control connecting rod and the bearing bush;

Figure 5 is a schematic diagram of the lower bearing shell and the remaining surface height of the lower bearing shell;

Figure 6 is an assembly diagram of the upper link, the control link, and the lower link of the first embodiment;

Figure 7 is an exploded schematic view of the lower link of the first embodiment;

Figure 8 is a schematic diagram of the connection of the reaming seat, the connecting arm and the hinge pin;

9 is a schematic diagram of the force analysis of the upper link, the control link, and the lower link of the first embodiment;

Figure 10 is a schematic diagram of the force of the upper connecting rod and the control connecting rod connected by connecting rod bolts at both ends;

Figure 11 is an assembly diagram of the upper link, the control link, and the lower link of the second embodiment;

Figure 12 is an exploded schematic view of the lower link of the third embodiment;

Figure 13 is a schematic diagram of the assembly of the lower link of the fourth embodiment;

Figure 14 is an exploded schematic view of the lower link of the fourth embodiment;

Figure 15 is an exploded schematic view of the lower link of the fifth embodiment;

16 is a cross-sectional view of the upper connecting rod part and the control connecting rod part being rotatably connected at one end, and connecting rod bolts at the other end;

17 is a schematic diagram of the projection area of the lower link of the first embodiment;

Figure 18 is a schematic diagram of the interference between the projection area and the central hole;

19 is a partial solution schematic diagram of the upper link portion and the control link of the lower link in the first embodiment;

20 is a partial solution schematic diagram of the upper link portion and the control link of the lower link in the fifth embodiment;

Figure 21 is a schematic diagram of the relative rotation angle of the upper link portion and the control link portion;

Figure 22 is a plan view of the boss set on the upper link part;

FIG. 23 is a partial enlarged schematic diagram of M in FIG. 22;

Figure 24 is a perspective view of the boss set on the upper link part;

Figure 25 is a schematic diagram of the boss set on the control link and the lower bearing shell has a remaining height;

FIG. 26 is a partial enlarged schematic diagram of position N in FIG. 25;

Figure 27 is a schematic diagram of the assembly of the lower connecting rod, the upper bearing and the lower bearing;

Figure 28 is an exploded schematic diagram of the lower connecting rod, the upper bearing and the lower bearing;

Figure 29 is a schematic view of the assembly of the piston, the upper connecting rod, the lower connecting rod of the sixth embodiment, and the compression ratio adjusting mechanism;

Figure 30 is a schematic diagram of the assembly of the upper link, the lower link of the sixth embodiment, and the control link;

Figure 31 is a cross-sectional view of the upper link, the lower link of the sixth embodiment, and the control link;

Figure 32 is a front view of the lower link of the sixth embodiment;

Figure 33 is a cross-sectional view of the lower link of the sixth embodiment;

Figure 34 is a perspective view of the lower link of the seventh embodiment;

Figure 35 is an exploded schematic view of the lower link of the eighth embodiment;

Figure 36 is a cross-sectional view of the lower link of the ninth embodiment;

Figure 37 is a schematic diagram of the assembly of the upper link, the lower link of the tenth embodiment, and the control link;

Figure 38 is an exploded schematic view of the lower link of the tenth embodiment;

Fig. 39 is a sectional view of the lower link of the tenth embodiment.

Description of Reference Signs: Piston 1, upper connecting rod 2, crankshaft 4, main journal 41, connecting rod journal 42, compression ratio adjusting mechanism 7, control connecting rod 5, eccentric shaft 6, drive shaft 61, eccentric wheel 62, piston pin A. Connecting rod pin B, bearing bush C, control connecting rod pin D, lower connecting rod 3, upper connecting rod portion 31, upper connecting rod pin hole 311, first arm 312, first threaded hole 314, upper center half hole 316. Control link portion 32, control link pin hole 321, second arm 322, second bolt hole 323, second threaded hole 324, lower center half hole 326, center hole 33, connecting rod bolt 35, process bolt 36, boss 37, reaming seat boss 371, connecting arm boss 372, stiffener 38, parting surface 40, upper parting surface 401, lower parting surface 402, reaming seat 51, first reaming seat 511, second reaming seat 512, connecting arm 52, first connecting arm 521, second connecting arm 522, hinge pin 53, hinge pin hole 54, upper bearing 81, lower bearing 82, remaining surface height 91, projection area Q .

Specific embodiment

In order to make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of the embodiments of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

Hereinafter, the present invention will be described in detail with reference to FIGS. 1 to 28 in conjunction with embodiments.

Referring to FIGS. 1 to 3, the engine may include: a piston 1, an upper connecting rod 2, a lower connecting rod 3, a crankshaft 4, and a compression ratio adjusting mechanism 7. Specifically, the lower connecting rod 3 of the embodiment of the present invention is suitable for hinged connection with the crankshaft 4 of the engine, and the piston 1 can move in the cylinder of the engine. As shown in FIGS. 1 and 2, the piston 1 can be in the cylinder bore The inner moves along the up-and-down direction of Figure 1-Figure 2.

The main journal 41 of the crankshaft 4 is rotatably arranged on the cylinder of the engine, and the connecting rod journal 42 of the crankshaft 4 is offset from the central axis of the main journal 41. There may be multiple connecting rod necks 42 of the crankshaft 4.

The lower connecting rod 3 is sleeved on one of the connecting rod necks 42, specifically, the lower connecting rod 3 is provided with a central hole 33, the connecting rod neck 42 is located in the central hole 33, and the lower connecting rod 3 and the connecting rod neck 42 can be Rotate each other. In some embodiments, a connecting rod neck pin or a bearing bush C may be arranged between the lower connecting rod 3 and the connecting rod neck 42 to reduce the wear of the lower connecting rod 3 and the connecting rod neck 42 and prolong the service life of engine parts.

The upper connecting rod 2 is connected between the piston 1 and the lower connecting rod 3, that is, the first end of the upper connecting rod 2 is connected with the piston 1, and the second end of the upper connecting rod 2 is connected with the lower connecting rod 3. Specifically, the first end of the upper connecting rod 2 is hinged with the piston 1, and the second end of the upper connecting rod 2 is hinged with the lower connecting rod 3, so that the upper connecting rod 2 and the piston 1 can rotate mutually. The connecting rod 2 and the lower connecting rod 3 can rotate with each other. In this way, when the lower connecting rod 3 rotates around the connecting rod neck 42 sheathed thereon, the upper connecting rod 2 can be driven to move, thereby driving the piston 1 to move up and down.

The compression ratio adjusting mechanism 7 is used to adjust the position of the piston 1 in the cylinder, so that the position of the piston 1 relative to the cylinder at the top dead center and bottom dead center is changed, and then the compression ratio is changed. As shown in Figures 1 to 2, the compression ratio adjustment mechanism 7 may include: an eccentric shaft 6 and a control link 5, the control link 5 is connected between the lower link 3 and the eccentric shaft 6, and the first end of the control link 5 Connected to the lower link 3, and the second end of the control link 5 is eccentrically connected to the eccentric shaft 6, so that when the eccentric shaft 6 rotates, the power of the eccentric shaft 6 can be transmitted to the lower link 3 through the control link 5, so that The lower link 3 rotates around the connecting rod neck 42 sheathed thereon.

Specifically, when the eccentric shaft 6 rotates, the control connecting rod 5 is pushed to rotate to push the lower connecting rod 3 to rotate, the lower connecting rod 3 pushes the upper connecting rod 2 to rotate, and the upper connecting rod 2 pushes the piston 1 to move up and down. Adjust the position of the piston 1 in the cylinder. Piston 1 moves up and down to change the volume of the combustion chamber, thereby changing the compression ratio. In other words, the compression ratio adjustment mechanism 7 can function to change the engine compression ratio. By changing the compression ratio, it can meet the needs of different loads of the engine, so that the engine always works in the best working area, which not only improves the power performance, reduces fuel consumption, but also reduces emissions, which solves the problem of power, economy, and emissions. The contradiction of sex makes the engine always work in the best fuel consumption zone.

It should be noted that in the description of the present invention, the "first end" of the part refers to the upper end in the figure, and the "second end" refers to the lower end in the figure, but the "first end" and "second end" Words indicating directions such as "end", "upper", "lower" are only for convenience of description, and should not be regarded as a limitation of the present invention.

In a specific embodiment, the compression ratio adjustment mechanism 7 has a small number of parts, which can achieve the purpose of changing the engine compression ratio, which is beneficial to reduce the assembly process of the engine, and the number of parts is small, which is beneficial to improve the compression ratio adjustment mechanism. 7 working reliability.

1, the eccentric shaft 6 may include: a drive shaft 61 and an eccentric 62, the drive shaft 61 is rotatably arranged on the cylinder, the eccentric 62 is eccentrically sleeved on the drive shaft 61, and the eccentric 62 and The drive shaft 61 is relatively fixed. The first end of the control link 5 is hinged with the lower link 3, and the second end of the control link 5 is hinged with the drive shaft 61 through an eccentric 62, so that the control link 5 and the lower link 3 can rotate mutually, and control The connecting rod 5 and the drive shaft 61 are mutually rotatable.

Further, the compression ratio adjusting mechanism 7 may further include: a driving device, which is connected to the driving shaft 61, and the driving device is used to drive the driving shaft 61 to rotate. Specifically, the driving device provides a driving torque for the driving shaft 61 to rotate the driving shaft 61. The first end of the upper connecting rod 2 and the piston 1 are hinged with the piston pin A, and the second end of the upper connecting rod 2 and the lower connecting rod 3 are hinged with the connecting rod pin B.

As shown in Figure 1 to Figure 3, further, the first end of the control link 5 and the lower link 3 are hinged by a control link pin D, and the link pin B and the control link pin D are set in the lower link 3 Located on both sides of the connecting rod neck 42. In other words, the lower link 3 is provided with an upper link pin hole 311 and a control link pin hole 321, and the upper link pin hole 311 and the control link pin hole 321 are provided on both sides of the central hole 33 of the lower link 3, preferably Ground, the line connecting the center lines of the upper link pin hole 311 and the control link pin hole 321 passes through the center line of the center hole 33. The link pin B is located in the upper link pin hole 311, and the control link pin D is located in the control link pin hole 321. The crankshaft 4 is arranged between the piston 1 and the eccentric shaft 6, thereby making the crankshaft 4 closer to the piston 1, so that the kinetic energy of the piston 1 can be quickly transmitted to the crankshaft 4 when the fuel is burned, reducing the kinetic energy loss.

Hereinafter, the lower link 3 of the present invention will be described in detail with reference to FIGS. 1 to 28 in conjunction with embodiments.

Referring to Figures 2 to 4, Figure 6 to Figure 9, Figure 11 to Figure 21, Figure 27 to Figure 28, the lower link 3 according to the embodiment of the present invention may include: an upper link part 31, a control link part 32. The upper link portion 31 is connected to the control link portion 32, and at least one connection point is a rotation connection point. The upper link portion 31 and the control link portion 32 can rotate relative to each other around the rotation connection point, so that the upper link The portion 31 and the control connecting rod portion 32 are rotatably mounted on the connecting rod neck 42 of the crankshaft 4, that is, the lower connecting rod 3 is assembled with the crankshaft 4 by rotating around its rotational connection point.

Compared with the traditional method of simply using multiple bolts to connect the upper link portion 31 and the control link portion 32, the rotary installation method in the present invention can ensure that at least one end of the upper link portion 31 and the control link portion 32 rotates The connection point is pre-assembled, and then the opening angle of the upper link portion 31 and the control link portion 32 is changed, so that the upper link portion 31 and the control link portion 32 are matched with the connecting rod neck 42 to simplify the lower link The assembly process of 3 and crankshaft 4 reduces the difficulty of assembly.

The rotation axis of the rotation connection point is parallel to the axis of the central hole 33, so that the rotation trajectory of the upper link portion 31 and the rotation trajectory of the control link portion 32 are in the same plane, when the upper link portion 31 and the control link portion 32 When one end of the connecting point rotates relative to each other, the opening angle of the upper link portion 31 and the other end of the control link portion 32 can be changed. According to the lower connecting rod 3 of the embodiment of the present invention, the upper connecting rod portion 31 and the control connecting rod portion 32 can rotate relative to each other around the rotating connection point, thereby simplifying the assembly process of the lower connecting rod 3 and the crankshaft 4 and reducing the assembly difficulty.

Referring to Figures 2 to 4, 6 to 9, Figure 11 to Figure 18, and Figure 27 to Figure 28, at the rotating connection point, the upper link portion 31 and the control link portion 32 are rotated by the hinge pin 53 connection. In other words, the hinge pin 53 passes through the upper link portion 31 and the control link portion 32 to realize the hinge connection between the upper link portion 31 and the control link portion 32. In other words, the hinge pin 53 is the rotation connection point.

Further, referring to FIGS. 2 to 4, 6 to 7, 9, 9, 11 to 21, and 27 to 28, one of the upper link portion 31 and the control link portion 32 A reaming seat 51 is provided on the upper side, and the other is provided with a connecting arm 52. The reaming seat 51 and the connecting arm 52 are provided with a hinge pin hole 54 for mounting a hinge pin 53. The hinge pin 53 passes through the reaming hole seat 51. The hinge pin hole 54 and the hinge pin hole 54 on the connecting arm 52 realize the hinge connection between the upper link portion 31 and the control link portion 32 at the hinge pin 53. The hinge pin 53, the reaming hole base 51 and the connecting arm 52 form a hinge structure, and the above-mentioned rotating connection point is formed at the hinge structure.

For example, in the embodiments shown in FIGS. 11-12, 15 and 20-21, the upper link portion 31 is provided with a reaming seat 51, and the control link portion 32 is provided with a connecting arm 52. In the embodiments shown in FIGS. 2 to 4, 6 to 7, 9, 9, 13 to 14, 16 to 19, and 27 to 28, a reaming hole is provided on the control link portion 32 The seat 51 is provided with a connecting arm 52 on the upper link portion 31.

Optionally, referring to FIGS. 7-8, 12-15, and 19-20, the connecting arm 52 includes a first connecting arm 521 and a second connecting arm 522, and the first connecting arm 521 and the second connecting arm 521 The connecting arms 522 are arranged at intervals along the axis of the hinge pin 53, the reaming hole base 51 is sandwiched between the first connecting arm 521 and the second connecting arm 522, and the hinge pin 53 passes through the first connecting arm 521, the reaming hole base 51 and The second connecting arm 522. In other words, the connecting arm 52 has a bifurcated structure and supports both ends of the reaming hole base 51. The reaming seat 51 is a protruding structure. After assembly, the reaming seat 51 is located inside the connecting arm 52 and supports the middle part of the hinge pin 53. The hinge pin 53 connects the upper link portion 31 and the control link portion 32 of the lower link 3 together through the hinge pin hole 54 on the reaming hole seat 51 and the connecting arm 52, and the upper link portion 31 and the control link portion 32 can rotate relative to the hinge pin 53 to change the opening angle of the upper link portion 31 and the control link portion 32.

Optionally, in the embodiments shown in FIGS. 7-8, 12 and 19, the reaming seat 51 is a single reaming seat 51.

Optionally, in the embodiments shown in FIGS. 13-15 and 20, the reaming seat 51 includes a first reaming seat 511 and a second reaming seat 512, and the first reaming seat 511 and the second reaming seat 511 The hole bases 512 are arranged at intervals along the axis of the hinge pin 53, thereby reducing the thickness of the reaming base 51, thereby saving material for the reaming base 51. The first reaming base 511 and the second reaming base 512 are both provided with Hinge pin hole 54. When the reaming seat 51 is sandwiched between the first connecting arm 521 and the second connecting arm 522, the first reaming seat 511 fits the first connecting arm 521, and the second reaming seat 512 and the second connecting arm 522 Fit, the hinge pin 53 sequentially passes through the first connecting arm 521, the first reaming hole seat 511, the second reaming hole seat 512, and the hinge pin hole 54 on the second connecting arm 522, thereby connecting the upper link portion 31 and the control The link parts 32 are connected together.

In some embodiments of the present invention, referring to Figures 6, 9, and 17, a parting surface 40 is formed between the upper link portion 31 and the control link portion 32, and the lower link 3 is on the parting surface 40. The part is divided into two parts, the surface of the upper link portion 31 facing the control link portion 32 and the surface of the control link portion 32 facing the upper link portion 31 are both parting surfaces 40.

Referring to Figures 7, 12, 14-15, and 19-20, the upper link portion 31 is provided with an upper center half hole 316, the control link portion 32 is provided with a lower center half hole 326, The central half-hole 316 and the lower central half-hole 326 are combined to form a central hole 33, which is adapted to be sleeved on the connecting rod neck 42 of the crankshaft 4. When the crankshaft 4 rotates, it drives the lower connecting rod 3 to move.

The plane where the parting surface 40 is located passes through the axis of the central hole 33, which helps to ensure the weight balance of the upper connecting rod portion 31 and the control connecting rod portion 32, thereby helping to improve the dynamic balance performance of the lower connecting rod 3. It is beneficial to simplify the processing technology of the upper link portion 31 and the control link portion 32.

The reaming seat 51 mainly functions to connect the upper link portion 31 and the control link portion 32 and supports the hinge pin 53 and can be arranged on any side of the lower link 3-parting surface 40. There are mainly two structures of the reaming seat 51 on the side of the lower connecting rod 3 parting surface 40. Structure 1: Both the reaming seat 51 and the upper link pin hole 311 are located on the upper link portion 31, as shown in FIGS. 11-12, 15 and 20-21. The upper connecting rod portion 31 is connected to the upper connecting rod pin hole 311 and the support has a bifurcated structure to support both ends of the connecting rod pin B. The upper connecting rod portion 31 and the reaming seat 51 form a Y-shaped structure, wherein the reaming seat 51 It is a Y-shaped bottom, and the upper link portion 31 is a Y-shaped top. When this structure is under force, stress concentration is likely to occur at the junction of the reaming seat 51 and the upper connecting rod portion 31, and the transition between the two should be transitioned in a large arc. At the same time, in the embodiment of FIGS. 11 and 21, in order to avoid the movement track of the upper link 2 connected by the upper link pin hole 311, an avoiding groove is provided where the reaming seat 51 and the upper link portion 31 meet . Structure 2: Both the reaming seat 51 and the control link pin hole 321 are located in the control link portion 32, as shown in Figures 2 to 4, 6 to 7 and 9, 13 to 14, and 16 to 19, Shown in Figure 27-28. In this structure, it is not necessary to provide an escape groove on the reaming seat 51, so that the reaming seat 51 is slightly better than the first structure in terms of force and rigidity, and because the escape groove is no longer provided, the processing technology is simple.

Further, referring to Figures 9 and 11, the axis of the hinge pin hole 54 (the hinge hole pin 54 is not shown in Figures 9 and 11) sleeved outside the hinge pin 53 is located in the plane of the parting surface 40, that is, the hinge The axis of the pin 53 is located in the plane of the parting surface 40, that is, the plane of the parting surface 40 passes through the center of the hinge pin 53, thereby avoiding interference between the lower connecting rod 3 and the crankshaft 4 during the assembly process, and ensuring The assembly work proceeded smoothly.

Optionally, the axis of the hinge pin hole 54 is parallel to the axis of the center hole 33. When the upper link portion 31 and the control link portion 32 rotate relative to each other, the rotation center line is the axis of the hinge pin hole 54, thereby ensuring The rotation track of the upper link portion 31 and the rotation track of the control link portion 32 are in the same plane.

In some embodiments of the present invention, referring to Figs. 7, 12-16, 19-21, and 27-28, the upper link portion 31 is provided with an upper link pin hole 311, and the control link The rod portion 32 is provided with a control connecting rod pin hole 321. Seen from the axial direction of the lower connecting rod 3, as shown in FIG. 11, the parting surface 40 includes: an upper parting surface 401 close to the upper connecting rod pin hole 311 and Control the lower parting surface 402 of the connecting rod pin hole 321, and the hinge pin 53 is located at the upper parting surface 401.

In some embodiments of the present invention, referring to FIGS. 3 to 4, 7 and 12 to 16, one of the connection points between the upper link portion 31 and the control link portion 32 is a screw connection point.

Further, referring to Figures 3-4, Figure 7, Figure 13-14, Figure 16, the upper link portion 31 is provided with an upper link pin hole 311, and the control link portion 32 is provided with a control link The pin hole 321, the upper link portion 31 and the control link portion 32 are enclosed to form a central hole 33, the rotation connection point is located on the side of the central hole 33 close to the upper link pin hole 311, and the screw connection point is located on the center hole 33 Close to the side of the control link pin hole 321. If the distance between the center point line of the hinge pin 53 and the center point line of the center hole 33 is small, the wall thickness of the center hole 33 near the hinge pin 53 will be thinned. When a force is applied, the thinning area will be generated. The deformation is large, resulting in an increased risk of failure of the lower link 3. When the distance between the center point line of the hinge pin 53 and the center point line of the center hole 33 becomes larger, the overall structure of the lower link 3 will become larger, which is not conducive to the overall assembly of the lower link 3. Therefore, the distance between the center point line of the hinge pin 53 and the center point line of the center hole 33 is preferably within a range of 39 mm to 45 mm.

Optionally, a connecting rod bolt 35 is provided at the screw connection point. When assembling the lower connecting rod 3 with the connecting rod neck 42 of the crankshaft 4, a hinge pin 53 is used to first connect the upper connecting rod portion 31 and the control connecting rod portion 32. One end of the upper link section 31 and the control link section 32 are then rotated to increase the opening angle of the upper link section 31 and the control link section 32, thereby facilitating the upper link section 31 and the control connecting rod portion 32 are set on the connecting rod neck 42 of the crankshaft 4, and then at least one of the upper connecting rod portion 31 and the control connecting rod portion 32 is rotated so that the upper connecting rod portion 31 and the control connecting rod portion 32 The opening angle becomes smaller, the upper connecting rod portion 31 is brought into contact with the other end of the control connecting rod portion 32, and the connecting rod bolt 35 is used to fix the contact position, thereby completing the assembly of the lower connecting rod 3 and the crankshaft 4.

Optionally, the central axis of the connecting rod bolt 35 is perpendicular to the central axis of the hinge pin 53, thereby facilitating the tightening or loosening operation of the connecting rod bolt 35.

Referring to Figures 12 and 15, the control link portion 32 is provided with a second bolt hole 323, and the upper link portion 31 is provided with a first threaded hole 314 (not shown in Figures 12 and 15). The bolt 35 passes through the second bolt hole 323 and then is screwed into the first threaded hole 314 to realize the screw connection between the upper link portion 31 and the control link portion 32 at the screw connection point.

Referring to Figures 3 and 14, the control link portion 32 is provided with a second threaded hole 324, the upper link portion 31 is provided with a first bolt hole (not shown in Figures 3 and 14), and the connecting rod bolt 35 pierce the first bolt hole and then screw into the second threaded hole 324 to realize the screw connection between the upper link portion 31 and the control link portion 32 at the screw connection point.

Hereinafter, the force of the lower link 3 will be described with reference to FIGS. 9-10.

In Figure 9-10 and Figure 17, Fa and Fa' are the force of the control link 5 on the lower link 3, Fb and Fb' are the combined force of the lower link 3, and Fc and Fc' are the upper link 2 For the force of the lower link 3, Fx and Fx' are shear forces, and Fy and Fy' are pressing forces. When the engine is working, the explosive pressure of the cylinder is transmitted to the upper connecting rod 2 through the piston 1, and the upper connecting rod 2 transmits the force to the lower connecting rod 3. This force is Fc. Fc will generate a component force on the parting surface 40 of the lower link 3, which is the shear force Fx.

Figure 10 is a schematic diagram of the force analysis of the upper connecting rod part 31 and the control connecting rod part 32 using connecting rod bolts 35 at both ends. Fx' acts on the connecting rod bolt 35, and the shear resistance of the connecting rod bolt 35 is compared It is weak, resulting in easy damage to the connection of the left connecting rod bolt 35 shown in FIG. 10. For the structure of the lower connecting rod 3 shown in Figure 10, in order to reduce the shear force Fx' received by the connecting rod bolt 35, it is necessary to ensure that the upper connecting rod 2 is transmitted to the lower connecting rod 3 when the engine maximum burst pressure is near. The direction of the force Fc' is substantially perpendicular to the parting surface 40 of the lower connecting rod 3. At this time, the angle θ'between the parting surface 40 and the upper connecting rod pin hole 311 and the control connecting rod pin hole 321 is larger. It is not conducive to the adjustment of the structure and size of the lower link 3.

9 is a schematic diagram of the force analysis of the upper connecting rod portion 31 and the control connecting rod portion 32 using a hinge pin 53 at one end and a connecting rod bolt 35 at the other end. When the engine maximum explosive pressure, the force on the lower connecting rod 3 makes it The control link portion 32 is tensioned, and the upper link portion 31 is compressed. When the inertial force is the maximum, the force received by the lower link 3 causes the control link portion 32 to be compressed, and the upper link portion 31 is tensioned. Since the maximum burst pressure is much greater than the maximum inertial force, the force when the hinge pin 53 is close to the upper link pin hole 311 is better than the force when the hinge pin 53 is close to the control link pin hole 321, so the hinge pin is used here. 53 is preferably designed at the position close to the upper link pin hole 311, as shown in Figure 2-Figure 4, Figure 6-Figure 7, Figure 9, Figure 11, Figure 13-Figure 14, Figure 16-Figure 19, Figure 21, Figure 27 -As shown in Figure 28. Since the lower link 3 adopts the hinge pin 53, the shear force Fx acts on the hinge pin 53 through the reaming hole base 51 and the connecting arm 52, and finally the hinge pin 53 overcomes the shear force Fx, and the shear force of the hinge pin 53 It is significantly better than the shear resistance of the connecting rod bolt 35, so the force of the lower connecting rod 3 is improved.

In addition, the explosive pressure of the cylinder is transmitted to the force Fc of the lower connecting rod 3, so that the upper connecting rod portion 31 of the lower connecting rod 3 is compressed. If the connecting rod bolt 35 is used for connection, when the pressing force Fy acts on the connecting rod connecting rod bolt At 35 o'clock, the end of the threaded hole is prone to stress concentration, resulting in thread failure. With the hinged structure, the pressing force Fy acts on the hinge pin 53 through the connecting arm 52, and the hinge pin hole 54 on the connecting arm 52 disperses the pressing force Fy along the edge of the hole, so that the hinge pin 53 is more evenly stressed and avoids The phenomenon of stress concentration occurs like the connecting rod bolt 35 connection.

In Figure 9, the hinge pin 53 can withstand a relatively large shear force. At the time of the engine maximum explosion pressure, the direction of the force Fc transmitted from the upper link 2 to the lower link 3 and the parting surface of the lower link 3 40 may not be close to the vertical. The angle θ between the parting surface 40 and the upper connecting rod pin hole 311 and the control connecting rod pin hole 321 is larger than the angle θ'when the connecting rod bolts 35 at both ends are connected. , The angle θ is between 45° and 65°.

In addition, because the hinge pin 53 itself cannot apply a pre-tightening force to the lower link 3, the other end of the lower link 3 needs to be connected with a pre-tightening force. The upper link portion 31 and the control link portion 32 are connected at the other end. The connection mode of the connecting rod bolt 35 is a connection mode that can apply pre-tightening force. Choosing the connecting rod bolt 35 to connect can also reduce the overall size, weight and processing difficulty of the lower connecting rod 3. Since the shear force generated on the lower connecting rod 3 is mainly overcome by the hinge pin 53, the connecting rod bolt 35 is almost free from shear force, which reduces the risk of failure of the connecting rod bolt 35. At the same time, the connecting rod bolt 35 can use a smaller size, which can reduce the size and weight of the lower connecting rod 3, thereby reducing the reciprocating inertia force of the lower connecting rod 3.

That is to say, after the upper link portion 31 and the control link portion 32 adopt a hinge structure at one end, the force at the other end of the link bolt 35 is improved, so the use specification of the link bolt 35 can be appropriately reduced to save costs.

Optionally, in the embodiments shown in FIGS. 12, 15, and 20, the hinge pin 53 may also be designed at a position close to the pin hole 321 of the control link.

In order to reduce the axial force deformation of the lower link 3, one of the hinge pin hole 54 on the connecting arm 52 and the hinge pin hole 54 on the reaming seat 51 adopts interference fit when mating with the hinge pin 53 . Since the upper link portion 31 and the control link portion 32 of the lower link 3 can rotate about the hinge pin 53, the hinge pin hole 54 on the connecting arm 52 and the hinge pin hole 54 on the reaming seat 51 are the other One fit with the hinge pin 53 may be a transition fit or a clearance fit. For example, in some embodiments of the present invention, as shown in FIG. 8, the hinge pin 53 and the hinge pin hole 54 of the reaming seat 51 are interference fit. , The hinge pin 53 and the hinge pin hole 54 of the connecting arm 52 are transition fit or clearance fit. However, in order to reduce the risk of separation of the lower connecting rod 3 due to the gap between the hinge pin 53 and the hinge pin hole 54 during operation, a transition fit is recommended. In order to further eliminate the gap between the hinge pin 53 and the hinge pin hole 54, after the lower connecting rod 3 and the crankshaft 4 are assembled, a pressing force can be applied on both sides of the hinge pin 53 to deform it under force and increase the radial dimension . At this time, it may be that the hinge pin 53 and the hinge pin hole 54 on the reaming hole seat 51 adopt an interference fit, and the hinge pin 53 and the hinge pin hole 54 on the connecting arm 52 adopt a transition fit.

In some unillustrated embodiments of the present invention, the upper link portion 31 and the control link portion 32 are connected by two connection points, and the two connection points are both rotating connection points. When assembling the upper link portion 31 and the control link portion 32, first complete the hinged connection of the upper link portion 31 and the control link portion 32 at one of the rotating connection points, and then adjust the upper link portion 31 and the control link portion The opening angle of the upper connecting rod part 32, and then the upper connecting rod part 31 and the control connecting rod part 32 are installed on the crankshaft 4, and finally the fixing of the upper connecting rod part 31 and the control connecting rod part 32 is completed at the other rotating connection point. Installation of the lower connecting rod 3 on the crankshaft 4.

Referring to Figures 17-18, the lower link 3 according to the present invention may include: an upper link portion 31, a control link portion 32, and at least one end of the connection between the upper link portion 31 and the control link portion 32 is hinged The pin 53 is hingedly connected, the upper connecting rod portion 31 is provided with an upper connecting rod pin hole 311 suitable for rotating connection with the upper connecting rod 2, and the upper connecting rod pin hole 311 is connected along the axis of the piston pin A and the axis of the connecting rod pin B A projection area Q is formed in the extending direction of the engine, and the hinge pin 53 is located in the projection area Q when the engine is at the maximum explosion pressure.

Fig. 17 is also a schematic diagram of the force of the lower link 3 when the engine is near the maximum burst pressure moment. Specifically, when the hinge pin 53 is in the projection area Q, the engine runs to near the maximum burst pressure moment, from the upper link 2 along Fig. 17 The force acting on the lower link 3 in the direction of the middle arrow is Fc, and the force Fc is decomposed along the parting surface 40 of the lower link 3. The two component forces are: the shear force Fx along the parting surface 40 and the vertical The pressing force Fy in the direction of the separating surface. The force Fy causes the upper link portion 31 of the lower link 3 to be compressed. At the moment of the maximum burst pressure, the force Fc is near the maximum value, which makes the component force Fy relatively large, effectively reducing the hinge pin 53 and the hinge pin hole 54 The gap between them causes the risk of the bearing C being separated. When the hinge pin 53 is in the projection area Q, the parting surface 40 of the lower link 3 is closest to the force Fc, that is, β is approximately equal to 90°, so that the shear force Fx is small, and the shear force Fx is mainly caused by the hinge pin. 53 bears, so that the connecting rod bolt 35 is basically free from shearing force, and the force requirement on the connecting rod bolt 35 is weakened.

According to the lower link 3 of the embodiment of the present invention, when the engine is at the maximum explosion pressure, the hinge pin 53 is located in the projection area Q, so that the force of the lower link 3 can be improved.

In some embodiments of the present invention, as shown in FIG. 7 and FIG. 17, the control link portion 32 is provided with a control link pin hole 321, the upper link pin hole 311, and the center line of the control link pin hole 321 The angle with the parting surface 40 is θ, and θ satisfies: 45°≤θ≤65°.

In some embodiments of the present invention, as shown in FIGS. 17-18, the area between the projection area Q and the central hole 33 is provided with reinforcing ribs 38 to increase the strength and rigidity of the area.

Further, as shown in FIG. 18, there is an interference area between the projection area Q and the central hole 33, and the reinforcing rib 38 is at least partially located in the projection area Q between the interference area and the upper link pin hole 311.

Specifically, referring to FIG. 17, the force transmitted from the upper link 2 acts on the lower link 3 through the upper link pin hole 311 in the arrow direction. This force causes deformation near the upper link pin hole 311 to improve The overall rigidity near the upper link pin hole 311 can shorten the distance between the upper link pin hole 311 and the center hole 33. As the distance between the upper link pin hole 311 and the center hole 33 is shortened, the overall size of the lower link 3 is reduced, making the engine mechanism more compact. At the same time, the weight of the lower link 3 will also be reduced, and the lower link 3 will be lighter, which reduces the inertial force it receives.

The distance between the upper connecting rod pin hole 311 and the center hole 33 is shortened, so that when the engine is near the highest compression ratio, the connecting rod pin B follows the straight line passing through the center of the piston pin A and the center of the connecting rod pin B during the operation of the mechanism. There will be slight interference between the projected projection area Q and the central hole 33 area, that is, there is an interference area between the projected area Q and the central hole 33, and the maximum interference area of the two does not exceed 1% of the central hole 33 area. In the vicinity of the highest compression ratio range, the working condition of the engine is low load. Since the maximum burst pressure of the low load working condition is much lower than the maximum burst pressure of the high load working condition, under this working condition, the projection area Q The slight interference with the area of the central hole 33 affects the deformation of the central hole 33 by increasing the structural strength of the lower connecting rod 3 in the interference area. The structural rigidity of this place can be strengthened by adjusting the position of the reinforcing rib 38 so that the position of the reinforcing rib 38 is included in the projection area Q. The strengthening of the structural rigidity here can eliminate the negative influence caused by the force deformation.

In some embodiments of the present invention, one of the connection points between the upper link portion 31 and the control link portion 32 is a screw connection point, and the screw connection point is located outside the projection area Q. For example, in FIG. 17, the hinge pin 53 is located on the left side of the central hole 33, and the screw connection point is located on the right side of the central hole 33.

Referring to Figures 19-21, the lower link 3 according to the present invention may include: an upper link portion 31, a control link portion 32, and at least one end of the connection between the upper link portion 31 and the control link portion 32 is rotatably connected , So that the upper link portion 31 and the control link portion 32 can relatively rotate around the rotation connection point.

Referring to FIG. 21, the relative rotation angle of the upper link portion 31 and the control link portion 32 is α, and the angle range of α is 0°～170°. For example, the upper link portion 31 and the control link portion 32 can rotate around The opening angle α of the hinge pin 53 can reach 160°-170°. By adjusting the opening angles of the upper connecting rod portion 31 and the control connecting rod portion 32, it is convenient for the lower connecting rod 3 to be put into the cylinder hole during assembly.

In some embodiments of the present invention, one of the upper link portion 31 and the control link portion 32 is provided with a reaming seat 51, and the other is provided with a connecting arm 52, a reaming seat 51 and a connecting arm 52 Rotation connection. Further, there is at least one reaming seat 51 and at least one connecting arm 52. For example, both the reaming seat 51 and the connecting arm 52 are one, and the reaming seat 51 and the connecting arm 52 are arranged adjacent to each other.

In some embodiments of the present invention, the thickness of the upper link portion 31 and the control link portion 32 are equal, and the sum of the thickness of the reaming seat 51 and the connecting arm 52 is equal to the thickness of the upper link portion 31 or the control link portion 32 Therefore, it is beneficial to ensure that the weight of the two parts of the lower link 3 is balanced.

Further, the upper link portion 31 is provided with an upper link pin hole 311, and the control link portion 32 is provided with a control link pin hole 321. In the embodiment of FIGS. 11 and 21, the reaming seat 51 is still located It is close to the position of the upper link pin hole 311, therefore, an escape groove is provided on the reaming hole seat 51, and the escape groove is recessed in a direction away from the upper link pin hole 311 to avoid the upper connecting rod pin hole 311. The trajectory of the upper link 2.

Further, referring to Figures 9 and 11, the center of the rotating connection point is located in the plane of the parting surface 40, that is, the plane of the parting surface 40 passes through the center of the rotating connection point, thereby avoiding the lower connection The rod 3 interferes with the crankshaft 4 during the assembly process.

Referring to Figures 3-4, 7, and 12-16, the lower link 3 according to the present invention may include: an upper link portion 31, a control link portion 32, an upper link portion 31 and a control link The parts 32 are connected, and one of the connection points is a rotation connection point, and the other connection point is an adjustable connection point.

Referring to Figures 22-28, a parting surface 40 is formed between the upper link portion 31 and the control link portion 32, and one end of the upper link portion 31 and the control link portion 32 that is rotationally connected is at the parting surface 40 There is a boss 37. At the rotation connection point, the hinge pin 53 passes through the hinge pin hole 54 on the upper link portion 31 and the control link portion 32 to realize the rotation connection of the upper link portion 31 and the control link portion 32. Due to the gap between the hinge pin hole 54 and the hinge pin 53, the risk of separation of the bearing C increases when the engine is running. By arranging the boss 37 at the parting surface 40 at the rotating connection point and applying an adjusting force at the adjustable connection point, the risk of separation of the bearing C can be reduced. Specifically, due to the lever principle, when a small adjustment force is applied at the adjustable connection point, the boss 37 can produce a large deformation, so that the lower link 3 can apply a large pre-tension to the bearing C. Tightening force, thereby reducing the risk of separation of bearing C. At the same time, the pre-tightening force can also prevent the deformation of the center hole 33 of the lower link 3 caused by the elastic tension of the bearing bush C.

In some embodiments of the present invention, referring to Figures 3, 7, 12, and 14-15, the upper link portion 31 is provided with an upper center half hole 316, and the control link portion 32 is provided with a lower The center half hole 326, the upper center half hole 316 and the lower center half hole 326 are combined to form the center hole 33, the adjustable connection point is a screw connection point, and the screw connection point and the rotation connection point are distributed on the parting surface 40 on both sides of the center hole 33 Place. A connecting rod bolt 35 is provided at the screw connection point. By changing the tightening degree of the connecting rod bolt 35, the adjustment force can be changed, thereby changing the pre-tightening force applied by the lower connecting rod 3 to the bearing C.

In some embodiments of the present invention, the reaming seat 51 is arranged at one end of the parting surface 40, and the boss 37 is arranged on the parting surface 40 on the side of the reaming seat 51, as shown in FIG. 25, the reaming seat 51 is arranged on the control link portion 32, the boss 37 and the reaming seat 51 both extend from the parting surface 40 of the control link portion 32, and extend the parting surface 40 of the upper connecting rod portion 31, and are connected After the rod portion 31 and the control connecting rod portion 32 are assembled and the connecting rod bolt 35 at the adjustable connection point is tightened, the boss 37 and the parting surface 40 of the upper connecting rod portion 31 contact and deform to enlarge the lower connecting rod 3 Pre-tightening force on bearing C.

In other embodiments of the present invention, the connecting arm 52 is arranged at one end of the parting surface 40, the boss 37 is arranged on the parting surface 40 on the side of the connecting arm 52, the reaming seat boss 371 and the control link The parting surface 40 of the portion 32 is deformed when contacted, and the pre-tightening force of the lower connecting rod 3 on the bearing C can also be increased.

In some embodiments of the present invention, as shown in FIGS. 27-28, the lower link 3 further includes bearing shells C respectively arranged in the upper link portion 31 and the control link portion 32, and the two bearing shells C are oppositely buckled It is installed in the center hole 33 in a closed manner, and as shown in Figures 25-26, the thickness of the boss 37 is not less than the remaining height 91 of the corresponding bearing shell C, thereby ensuring the adjustment force at the adjustable connection point When it is too large, the boss 37 can deform, thereby pre-tensioning the bearing C. Specifically, the bearing C provided in the upper link portion 31 is the upper bearing 81, and the bearing C provided in the control link portion 32 is the lower bearing 82. Taking the control link portion 32 as an example, the control link portion 32 The thickness of the boss 37 on the parting surface 40 is not less than the height 91 of the remaining surface of the lower bearing 82.

In some embodiments of the present invention, the boss 37 is an elongated boss 37 for easy processing, and the length direction of the boss 37 is parallel to the axis of the central hole 33. The number of the boss 37 is at least one.

In the embodiment shown in FIGS. 29-33 and the embodiment shown in FIGS. 35-36, the hinge pin hole is the control link pin hole 321. In the embodiment shown in FIG. 34 and the embodiment shown in FIGS. 37-39, the hinge pin hole is the upper link pin hole 311.

Referring to FIGS. 29-34, when the upper link portion 31 and the control link portion 32 are relatively rotated until the first end of the upper link portion 31 contacts the first end of the control link portion 32, the upper link portion 31 The first end and the first end of the control link portion 32 are connected by a link bolt 35, thereby fixing the upper link portion 31 and the control link portion 32 together, so as to realize the connection between the lower link 3 and the connecting rod neck的assembly. Compared with the traditional connecting rod portion 31 and the control connecting rod portion 32 that require two high-strength connecting rod bolts 35 to be connected, only one is needed in the embodiment shown in FIGS. 29-33 and the embodiment shown in FIG. 34 The connecting rod bolt 35, and because the main stress point of the lower connecting rod 3 is not on the connecting surface between the first end of the upper connecting rod portion 31 and the first end of the control connecting rod portion 32, the connecting rod bolt 35 can be more effective than the conventional connecting rod bolt. The strength level of 35 is weak, so as to help reduce the design difficulty of the lower connecting rod 3, reduce the specification of the connecting rod bolt 35, and reduce the size of the lower connecting rod 3.

30, the first end surface of the upper link portion 31 and the first end surface of the control link portion 32 constitute a parting surface 40, and the upper link portion 31 is provided with an upper center half hole 316, the control connection The rod portion 32 is provided with a lower center half hole 326. The upper center half hole 316 and the lower center half hole 326 are combined to form a center hole 33. The connecting rod neck of the crankshaft is located in the center hole 33. The lower connecting rod 3 and the connecting rod neck can be mutually connected. Rotate. The plane where the parting surface 40 is located passes through the axis of the central hole 33, so as to realize that the upper central half-hole 316 and the lower central half-hole 326 are both semicircular, thereby facilitating the processing of the upper central half-hole 316 and the lower central half-hole 326 , Improve processing accuracy.

In the embodiment shown in FIGS. 35-36 and the embodiment shown in FIGS. 37-39, the second end of the upper link portion 31 is in contact with the second end of the control link portion 32, and the upper link portion 31 The second end of the lower connecting rod 3 and the second end of the control connecting rod portion 32 are connected by the process bolt 36, which is beneficial to reduce the vibration and noise generated by the vibration of the lower connecting rod 3 during operation, thereby improving the NVH performance of the engine. The second end of the upper connecting rod portion 31 and the second end of the control connecting rod portion 32 receive less force during the operation of the lower connecting rod 3, and have lower requirements on the specifications and performance of the bolts. The strength level of 35 than the connecting rod bolt can be selected. The weak bolt is used as the craft bolt 36. The connecting rod bolts 35 and the process bolts 36 are distributed on both sides of the central hole 33, so as to ensure that the connection between the upper connecting rod portion 31 and the control connecting rod portion 32 is highly reliable.

The connecting rod bolt 35 and the process bolt 36 are in opposite directions. By installing the connecting rod bolt 35 and the process bolt 36 in opposite directions, it is not only helpful to improve the connection strength between the upper connecting rod portion 31 and the control connecting rod portion 32, but also Improve the strength of the connecting rod bolt 35 and the process bolt 36. For the conventional connecting rod bolt 35 arranged in the same direction, one of the two connecting rod bolts 35 will coincide with the position of the hinge pin hole or the second pin hole As a result, the connecting rod bolt 35 cannot be installed. Therefore, in order to solve the above problem, the connecting rod bolt 35 arranged in the same direction needs to be forced to increase the distance from the hinge pin hole to the center hole 33, or the second pin hole to the center hole 33 In order to ensure that the connecting rod bolt 35 can be installed smoothly, this in turn will not be conducive to the weight reduction of the lower connecting rod 3. Therefore, by reversing the orientation of the connecting rod bolt 35 and the process bolt 36, not only the reliability of the connection between the upper connecting rod portion 31 and the control connecting rod portion 32 can be ensured, but also the weight and volume of the lower connecting rod 3 can be kept small. , So as to help realize the lightweight of the engine. And as shown in FIG. 35, the extending end of the connecting rod bolt 35 and the extending end of the process bolt 36 are not blocked by any parts, and the lower connecting rod 3 has enough installation space to install the connecting rod bolt 35 and the process bolt 36 facing the opposite direction. .

35 and 38, at the hinge pin hole, the upper link portion 31 includes two spaced apart first branch arms 312, and the control link portion 32 is at least partially sandwiched between the two first branch arms 312 between. The control link portion 32 is assembled through the space formed by the two spaced apart first sub-arms 312 to realize the coaxial hinge joint of the upper link portion 31 and the control link portion 32 at the hinge pin hole.

Further, at the hinge pin hole, the control link portion 32 includes two spaced apart second branch arms 322, and the two second branch arms 322 are sandwiched between the two first branch arms 312 to realize the The upper connecting rod 2 or the control connecting rod 5 is connected in the two spaced apart second arms 322. In other words, in the embodiment shown in FIGS. 29-33 and the embodiment shown in FIGS. 35-36, the control link 5, the first arm 312, and the second arm 322 are coaxially hinged to the hinge pin hole Place. In the embodiment shown in Fig. 34 and the embodiment shown in Figs. 37-39, the upper link 2, the first arm 312, and the second arm 322 are coaxially hinged at the hinge pin hole. Further, an avoiding groove is provided at the joint of the two second sub-arms 322 to realize that the upper link 2 or the control link 5 does not interfere with the lower link 3 when the upper link 2 or the control link 5 moves at the hinge pin hole.

An engine according to another embodiment of the present invention includes the lower link 3 of the above embodiment. Compared with the prior art, the engine of the present invention has the following advantages: the engine of the present invention adopts the above-mentioned lower link 3, because at least one connection point between the upper link portion 31 and the control link portion 32 is a rotational connection point Therefore, the assembly of the lower connecting rod 3 and the crankshaft 4 is facilitated, and the force of the lower connecting rod 3 can be improved. Secondly, in the engine of the present invention, a boss 37 is provided at the parting surface 40 at one end of the upper connecting rod portion 31 and the control connecting rod portion 32, which can realize the pretension of the bearing C and reduce the risk of separation of the bearing C .

The term "one embodiment", "an embodiment" or "one or more embodiments" referred to herein means that a specific feature, structure or characteristic described in conjunction with the embodiment is included in at least one embodiment of the present invention. In addition, please note that the word examples "in one embodiment" herein do not necessarily all refer to the same embodiment.

In the instructions provided here, a lot of specific details are explained. However, it can be understood that the embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and technologies are not shown in detail, so as not to obscure the understanding of this specification.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions recorded in the foregoing embodiments are modified, or some of the technical features are equivalently replaced; these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (20)

1. A lower connecting rod (3), characterized in that the lower connecting rod (3) is provided with a central hole (33) matched with the crankshaft (4), and the lower connecting rod (3) comprises: an upper connecting rod Part (31), a control link part (32), the upper link part (31) is connected to the control link part (32), and at least one connection point is a rotation connection point, the rotation connection point The axis of rotation is parallel to the axis of the central hole (33).
2. The lower link (3) according to claim 1, characterized in that, at the rotating connection point, the upper link portion (31) and the control link portion (32) pass through a hinge pin (53). ) Realize rotating connection.
3. The lower link (3) according to claim 2, wherein one of the upper link portion (31) and the control link portion (32) is provided with a reaming seat ( 51), the other is provided with a connecting arm (52), the reaming seat (51) and the connecting arm (52) are provided with a hinge pin hole (54) for installing the hinge pin (53); The upper link part (31) is provided with an upper link pin hole (311), and the control link part (32) is provided with a control link pin hole (321).
4. The lower link (3) according to claim 3, characterized in that the connecting arm (52) comprises two first connecting arms (521) and a first connecting arm (521) and a second connecting arm (521) arranged at intervals along the axis of the hinge pin (53). Two connecting arms (522), the reaming seat (51) is sandwiched between the first connecting arm (521) and the second connecting arm (522).
5. The lower link (3) according to claim 3 or 4, characterized in that, the reaming seat (51) is a single reaming seat (51), and the reaming seat (51) includes two rims The first reaming seat (511) and the second reaming seat (512) are spaced apart in the axial direction of the hinge pin (53), and are connected to the first reaming seat (511) and the second reaming seat (512). ) Is provided with the hinge pin hole (54).
6. The lower link (3) according to claim 3, wherein a parting surface (40) is formed between the upper link portion (31) and the control link portion (32), and The upper link portion (31) is provided with an upper center half hole (316), the control link portion (32) is provided with a lower center half hole (326), the upper center half hole (316) and the The lower central half hole (326) is enclosed to form the central hole (33), and the plane where the parting surface (40) is located passes through the axis of the central hole (33).
7. The lower link (3) according to claim 6, characterized in that the axis of the hinge pin hole (54) lies in the plane of the parting surface (40).
8. The lower link (3) according to claim 6, wherein the upper link portion (31) is provided with an upper link pin hole (311), and the control link portion (32) is provided with There is a control connecting rod pin hole (321), viewed from the axial direction of the lower connecting rod (3), the parting surface (40) includes: an upper parting surface close to the upper connecting rod pin hole (311) (401) and the lower parting surface (402) close to the control link pin hole (321), and the hinge pin (53) is located at the upper parting surface (401).
9. The lower link (3) according to claim 3, characterized in that one of the connection points between the upper link portion (31) and the control link portion (32) is a screw connection point.
10. The lower link (3) according to claim 9, characterized in that, the central hole (33) is enclosed between the upper link portion (31) and the control link portion (32), so The rotating connection point is located on the side of the central hole (33) close to the upper link pin hole (311), and the screw connection point is located on the central hole (33) close to the control link pin hole (321) side.
11. The lower link (3) according to claim 9, wherein a bolt (35) is provided at the screw connection point, and the center axis of the bolt (35) is aligned with the center of the hinge pin (53). The axis is vertical.
12. The lower link (3) according to claim 3, characterized in that the hinge pin hole (54) on the connecting arm (52) and the hinge pin hole (54) on the reaming seat (51) One of the two is interference fit when matched with the hinge pin (53), and the other is a transition fit or clearance fit when matched with the hinge pin (53).
13. The lower link (3) according to claim 1, wherein the upper link portion (31) and the control link portion (32) are connected by two connecting points, and the two The connection points are all rotating connection points.
14. The lower link (3) according to claim 3, wherein the hinge pin hole (54) is the upper link pin hole (311), or the hinge pin hole (54) is the link pin hole ( 321).
15. The lower link (3) according to claim 14, wherein the first end surface of the upper link portion (31) and the first end of the control link portion (32) The end surface constitutes a parting surface (40), the second end of the upper link portion (31) is in contact with the second end of the control link portion (32), and the upper link portion (31) The second end and the second end of the control connecting rod portion (32) are connected by a process bolt (36).
16. The lower connecting rod (3) according to claim 15, characterized in that the bolts (35) and the process bolts (36) are distributed on both sides of the central hole (33).
17. The lower connecting rod (3) according to claim 16, characterized in that the direction of the bolt (35) and the process bolt (36) are opposite.
18. The lower link (3) according to claim 14, characterized in that, at the hinge pin hole (54), the upper link portion (31) includes two spaced apart first branch arms (312). ), the control link portion (32) is at least partially sandwiched between the two first branch arms (312).
19. The lower link (3) according to claim 18, characterized in that, at the hinge pin hole (54), the control link portion (32) includes two spaced-apart second branch arms (322). ), the two second sub-arms (322) are sandwiched between the two first sub-arms (312), and the joint of the two second sub-arms (322) is provided with an escape groove .
20. An engine, characterized by comprising: a piston (1), the piston (1) is adapted to move in the cylinder of the engine; a crankshaft (4), the main journal (41) of the crankshaft (4) can be It is rotatably arranged on the cylinder of the engine; according to the lower connecting rod (3) of any one of claims 1-19, the lower connecting rod (3) is sleeved on the crankshaft (4) Connecting rod neck (42); upper connecting rod (2), said upper connecting rod (2) is connected between said piston (1) and said lower connecting rod (3); compression ratio adjusting mechanism (7) The compression ratio adjusting mechanism (7) is used to adjust the position of the piston (1) in the cylinder, and the compression ratio adjusting mechanism (7) includes a control connecting rod (5), the control connecting rod (5) Articulated with the lower connecting rod (3).

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