CN113795656A - Variable compression ratio mechanism, engine and automobile - Google Patents
Variable compression ratio mechanism, engine and automobile Download PDFInfo
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- CN113795656A CN113795656A CN201980087088.6A CN201980087088A CN113795656A CN 113795656 A CN113795656 A CN 113795656A CN 201980087088 A CN201980087088 A CN 201980087088A CN 113795656 A CN113795656 A CN 113795656A
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- compression ratio
- center
- connecting rod
- variable compression
- positioning
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B75/00—Other engines
- F02B75/04—Engines with variable distances between pistons at top dead-centre positions and cylinder heads
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D15/00—Varying compression ratio
- F02D15/02—Varying compression ratio by alteration or displacement of piston stroke
Abstract
A variable compression ratio mechanism, a variable compression ratio engine and an automobile comprise a piston (1) arranged in an engine cylinder body in a sliding way, a crankshaft (4) arranged in the engine cylinder body in a rotating way and an eccentric shaft (6) with an eccentric wheel (7), an adjusting connecting rod (3) arranged on a crank pin (14) in the crankshaft (4) in a rotating way, and an execution connecting rod (2) and a driving connecting rod (5) which are hinged to two ends of the adjusting connecting rod (3) and are respectively hinged and connected with the piston (1) and the eccentric wheel (7); and the pivot angle of the actuating connecting rod (2) is set to be lower than 30 degrees by taking a hinge shaft between the actuating connecting rod (2) and the piston (1) as a swing center, and the pivot angle of the driving connecting rod (5) is set to be smaller than 27 degrees by taking the eccentric wheel (7) as a swing center.
Description
Cross Reference to Related Applications
The present disclosure claims priority of application date of 2019, 30.12.2019, application No. 201811646188.1, and patent application name of "variable compression ratio mechanism and engine", and priority of application date of 2019, 30.12.2019, application No. 201811646189.6, and patent application name of "variable compression ratio mechanism and engine".
The disclosure relates to the technical field of engines, in particular to a variable compression ratio mechanism, and also relates to a variable compression ratio engine with the variable compression ratio mechanism and an automobile with the variable compression ratio engine.
At present, engines used on automobiles are all fixed compression ratio engines, namely the compression ratio of the engine cannot change along with the load. However, the compression ratio should be determined as a compromise result of power performance, economy and combustion, which cannot be too large or too small, and at low speed and low load or partial load, if the compression ratio is too small, the combustible mixture cannot be sufficiently mixed, which results in low combustion efficiency, high fuel consumption, and insufficient combustion emission, whereas at high speed and high load, if the compression ratio of the engine is too large, knocking is easily generated, and if the compression ratio is light, the power output is affected, and if the compression ratio is heavy, the engine parts are damaged.
The multi-connecting-rod type variable compression ratio mechanism is the only engine technology which achieves mass production conditions, and changes the compression ratio of an engine by continuously changing the top dead center position of a piston of the engine so as to meet different engine load requirements and enable the engine to work in an optimal working area all the time, so that the power performance of the engine can be improved, the oil consumption can be reduced, the emission can be reduced, and the contradiction between the power performance, the economy and the emission performance can be well solved.
The existing multi-connecting-rod type variable compression ratio mechanism is generally composed of a piston, a crankshaft, an eccentric shaft with an eccentric wheel, an adjusting connecting rod rotating on a crank pin of the crankshaft, an executing connecting rod and a driving connecting rod hinged at two ends of the adjusting connecting rod and respectively hinged with the piston and the eccentric shaft.
Under the rotation of the eccentric shaft, the top dead center of the piston can be changed through the linkage of the multi-connecting-rod structure, so that the change of the compression ratio can be realized. However, in the existing variable compression ratio mechanism with a multi-link structure, because the swing angle of the link is large, the abrasion loss of the link is large, the abrasion is serious, and the reliability of the mechanism is influenced after a long time.
In addition, the adjusting link is generally formed in a separate structure in an expansion-breaking manner and is connected to the adjusting link by a connecting member such as a connecting member. During the operation of the engine, the combustion and explosion force in the cylinder borne by the piston is transmitted to the multi-connecting-rod structure, so that the stress on the connecting piece in the adjusting connecting rod is large, particularly the connecting piece can bear large tangential force, the connecting piece is easy to damage, the connection failure is further caused, and the normal operation of the engine is influenced.
Disclosure of Invention
In view of the above, the present disclosure is directed to a variable compression ratio mechanism capable of reducing a swing angle of a connecting rod during engine operation, thereby reducing wear of the connecting rod.
In order to achieve the purpose, the technical scheme of the disclosure is realized as follows:
a variable compression ratio mechanism comprises a piston arranged in an engine cylinder in a sliding manner, a crankshaft arranged in the engine cylinder in a rotating manner, an eccentric shaft with an eccentric wheel, an adjusting connecting rod arranged on a crank pin in the crankshaft in a rotating manner, and an executing connecting rod and a driving connecting rod which are hinged to two ends of the adjusting connecting rod and are respectively hinged with the piston and the eccentric wheel; and the swing angle of the actuating connecting rod is set to be lower than 30 degrees by taking the actuating connecting rod and the hinge shaft between the pistons as swing centers, and the swing angle of the driving connecting rod is set to be smaller than 27 degrees by taking the eccentric wheel as a swing center.
Further, a distance L1 between the centers of the hinge shafts at both ends of the actuating link, a distance L2 between the center of the crankpin and the centers of the hinge shafts between the adjusting link and the actuating link, a distance L3 between the center of the crankpin and the centers of the hinge shafts between the adjusting link and the actuating link, and a distance L4 between the centers of the hinge shafts at both ends of the actuating link are set to satisfy the following relations: L1/L3 ═ L4/L2.
Further, a distance L3 between the center of the crank pin and the center of the hinge shaft between the adjusting link and the driving link, a distance L4 between the centers of the hinge shafts at both ends of the driving link, a distance L5 between the center of the eccentric wheel and the center of the rotation of the crankshaft, and a distance r between the center of the rotation of the crankshaft and the center of the crank pin are set to satisfy a value of (L42+ L32-r2)/L52 of 0.9-1.1.
Furthermore, the piston and the execution connecting rod are hinged and connected through a connecting pin, and the execution connecting rod, the driving connecting rod and the adjusting connecting rod are hinged and connected through a connecting pin.
Furthermore, a bushing pressed in the corresponding pin hole is arranged at each connecting pin.
Furthermore, the adjusting connecting rod comprises an upper rod part and a lower rod part which are fixedly connected together through a connecting piece, a joint surface between the upper rod part and the lower rod part is orthogonal to the axis of the connecting piece, a mounting hole for the crank pin to pass through is formed between the upper rod part and the lower rod part in a surrounding mode, and the connecting piece is divided into two parts which are arranged on two opposite sides of the mounting hole.
Further, the connecting piece is a bolt.
Further, the upper rod part and the lower rod part are formed by a powder forging process.
Furthermore, a meshing part which is used for forming mutual meshing between the upper rod part and the lower rod part is arranged at the joint surface.
Further, the snapping part comprises a positioning protrusion integrally configured on the upper rod part and a groove configured on the lower rod part corresponding to the positioning protrusion, and the positioning protrusion is embedded in the groove.
Furthermore, the occlusion part comprises pin holes correspondingly arranged on the upper rod part and the lower rod part, and positioning pins with two ends respectively inserted in the pin holes on the upper rod part and the lower rod part.
Furthermore, the engaging part comprises a positioning groove, a positioning sleeve ring and a positioning raised head, wherein the positioning groove is formed on the upper rod part, the positioning sleeve ring is embedded into the positioning groove and sleeved on the connecting piece, the positioning sleeve ring is provided with the positioning raised head, and the positioning hole is formed on the lower rod part, is matched with the positioning raised head and is embedded into the positioning hole.
Further, the upper rod part and the lower rod part are formed by a powder forging process.
Further, the distance e between the movement track of the center of the hinge shaft between the piston and the actuating connecting rod and the perpendicular line of the rotation center of the crankshaft is set to be 30-40 degrees between the movement track of the center of the hinge shaft between the piston and the actuating connecting rod and the connecting line between the rotation center of the crankshaft and the center of the crank pin, and the connecting line between the centers of the hinge shafts at the two ends of the actuating connecting rod is parallel or nearly parallel to the axis of the connecting piece.
Compared with the prior art, the method has the following advantages:
(1) the variable compression ratio mechanism of the present disclosure can reduce the friction loss of the connecting rod and the reciprocating inertia force thereof by limiting the swing angle of the connecting rod during operation, thereby reducing the abrasion of the connecting rod.
In addition, in the present disclosure, by setting the distance relationship between the members, it is possible to reduce the swing angle of the link during operation, so that the friction loss of the link can be reduced by the reduction of the swing angle, and the swing acceleration of the link can be reduced to reduce the reciprocating inertia force of the link, thereby reducing the wear of the link.
(2) According to the variable compression ratio mechanism, when the included angle CA is 30-40 degrees, namely the crankshaft rotates to the position near the maximum explosion pressure of the cylinder, the axis of the execution connecting rod is parallel or nearly parallel to the axis of the connecting piece, so that the explosion pressure of the cylinder transmitted to the adjusting connecting rod by the execution connecting rod is transmitted along the axial direction of the connecting piece, the tangential force borne by the connecting piece is reduced, and the connecting piece can be prevented from being damaged, and the connection reliability can be guaranteed.
In addition, according to the adjusting connecting rod, the meshing part is arranged at the joint surface between the upper rod part and the lower rod part in the adjusting connecting rod, and when the explosion pressure of the cylinder is smaller than the maximum value, the meshing part bears the tangential force borne by the connecting piece, so that the tangential force of the connecting piece can be reduced, the connecting piece is prevented from being damaged, and the connecting reliability can be guaranteed.
Another object of the present disclosure is to propose a variable compression ratio engine comprising an engine block, further comprising a variable compression ratio mechanism as described above provided in said engine block.
It is a further object of the present disclosure to provide an automobile including the variable compression ratio engine described above.
The accompanying drawings, which are included to provide a further understanding of the disclosure, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure and are not to limit the disclosure. In the drawings:
fig. 1 is a schematic structural view of a variable compression ratio mechanism according to a first embodiment of the present disclosure;
FIG. 2 is a schematic structural diagram of an adjusting link according to a first embodiment of the disclosure;
fig. 3 is a schematic structural view of an engaging portion formed by the positioning protrusion and the groove according to a first embodiment of the disclosure;
FIG. 4 is a schematic structural view of a snap-in portion formed by a positioning pin and a pin hole according to a first embodiment of the present disclosure;
fig. 5 is a schematic structural view of an engaging portion formed by the positioning collar and the positioning hole according to the first embodiment of the disclosure;
FIG. 6 is a graph illustrating the relationship between the distance and angle between the components of the variable compression ratio mechanism according to the first embodiment of the present disclosure;
fig. 7 is a schematic swing diagram of an actuating link according to a first embodiment of the disclosure (a dotted line structure in the drawing illustrates the actuating link when swinging to the other side limit position);
fig. 8 is a schematic swinging diagram of a driving link according to a first embodiment of the disclosure (a dotted line structure in the drawing illustrates the driving link swinging to the other side limit position);
FIG. 9 is a schematic view of an angle adjustment link according to a first embodiment of the present disclosure;
description of reference numerals:
1-piston, 2-actuating link, 3-adjusting link, 4-crankshaft, 5-driving link, 6-eccentric shaft, 7-eccentric wheel, 8-link, 9-locating pin, 10-locating collar, 11-piston connecting pin, 12-actuating link connecting pin, 13-driving link connecting pin, 14-crank pin;
101-positioning raised heads;
301-upper rod part, 3011-positioning bulge, 302-lower rod part, 303-mounting hole and 304-connecting pin hole of adjusting connecting rod.
It should be noted that, in the present disclosure, the embodiments and features of the embodiments may be combined with each other without conflict.
The present disclosure will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.
Example one
The present embodiment relates to a variable compression ratio mechanism which is a multi-link type variable compression ratio mechanism, and as shown in fig. 1, the mechanism includes a piston 1 slidably provided in an engine block, not shown in the drawings, a crankshaft 4 rotatably provided in the engine block and an eccentric shaft 6 having an eccentric 7, an adjusting link 3 rotatably provided on a crank pin in the crankshaft 4, and an actuating link 2 and a driving link 5 hinged to both ends of the adjusting link 3 and hinged to the piston 1 and the eccentric 7, respectively.
As shown in fig. 2, the structure of the adjusting link 3 specifically includes an upper rod portion 301 and a lower rod portion 302 which are fixedly connected together by a connecting piece 8, the structures of the upper rod portion 301 and the lower rod portion 302 are preferably set to be the same, and both can be formed by a powder forging process, and a joint surface M is formed between the two due to connection, and the joint surface M is also orthogonally arranged with respect to the axis of the connecting piece 8. Further, a mounting hole 303 for passing a crank pin of the crankshaft 4 is also formed between the upper rod portion 301 and the lower rod portion 302, that is, the adjusting link 3 is rotatably mounted on the crank pin through the mounting hole 303, and the connecting members 8 are respectively provided at two opposite sides of the mounting hole 303.
In this embodiment, the connecting member 8 for fixedly connecting the two rod portions of the adjusting connecting rod 3 is preferably a bolt, and both the upper rod portion 301 and the lower rod portion 302 as the main structure of the adjusting connecting rod 3 can be formed by a powder forging process, and after the connecting member 8 is connected, the upper rod portion 301 and the lower rod portion 302 are in a central symmetrical structure relative to the center of the mounting hole 303. The upper rod part 301 and the lower rod part 302 are respectively provided with a through adjusting connecting rod pin hole 304, and the actuating connecting rod 2 and the driving connecting rod 5 are respectively connected with the adjusting connecting rod pin holes 304 on the upper rod part 301 and the lower rod part 302.
In addition, in the present embodiment, an engaging portion for engaging the upper rod portion 301 and the lower rod portion 302 with each other is also provided at the upper rod portion 301 and the joint surface M. The engagement part can share the component force of the explosion pressure along the joint surface when the explosion pressure in the cylinder is transmitted to the adjusting connecting rod 3 through the actuating connecting rod 2 in the running process of the engine, so that the tangential force born by the connecting piece 8 formed by the bolt can be reduced, and the aim of avoiding the damage of the bolt can be fulfilled.
Structurally, as a possible structure, as shown in fig. 3, for example, the engaging portion includes a positioning protrusion 3011 integrally formed on the upper rod portion 301, and a groove is formed on the lower rod portion 302 corresponding to the positioning protrusion 3011, and the positioning protrusion 3011 is inserted into the groove, thereby achieving the mutual engagement between the upper rod portion 301 and the lower rod portion 302.
As another possible structure, as shown in fig. 4, the engaging portion may also include pin holes correspondingly formed on the upper rod portion 301 and the lower rod portion 302, and positioning pins 9 respectively inserted into the pin holes formed on the upper rod portion 301 and the lower rod portion 302 at two ends. Thus, the upper rod portion 301 and the lower rod portion 302 can be engaged with each other by inserting both ends of the positioning pin 9 into the pin holes of the two rod portions.
It should be noted that the shape of the positioning protrusion 3011 is not limited to that shown in fig. 3, and the matching groove may be any shape that can make the two rods assume a snap-fit shape. Meanwhile, the positioning pin 9 is also the same as the positioning protrusion 3011, and the cross-sectional shape of the pin hole matched with the positioning pin is not limited, so that the snap function can be realized. In addition, for the positioning protrusions 3011 or the positioning pins 9, the number of the positioning protrusions and the arrangement rule at the joint surface M can be selected according to the shape and the size of the joint surface between the upper rod portion 301 and the lower rod portion 302, and the positioning protrusions and the positioning pins do not affect the structural strength of the joint surface between the two rod portions, and can ensure that a required biting force is obtained.
Of course, in addition to the positioning protrusions 3011 and the positioning pins 9, as another possible structure, as shown in fig. 5, the engaging portion of the present embodiment may further include a positioning groove formed on the upper rod portion 301 around the connecting member 8, a positioning collar 10 having a positioning protrusion 101 embedded in the positioning groove and sleeved on the connecting member 8, and a positioning hole formed on the lower rod portion 302 also around the connecting member 8. The positioning holes are arranged in a shape, number and position arrangement which is matched to the positioning projections 101 on the positioning collar 10, so that the positioning projections 101 can be inserted into the positioning holes, and the two rod parts can be engaged with each other.
In addition to the above-described adjusting link 3 in the present embodiment, other components such as the actuating link 2, the driving link 5, and others can be referred to in the related art of the engine. In a preferred embodiment, the piston 1 and the actuating link 2, the actuating link 2 and the adjusting link 3, and the driving link 5 and the adjusting link 3 are hinged by connecting pins. At this time, the piston 1 and the actuating link 2 are hinged to each other by a piston connecting pin 11, and the adjusting link 3 is hinged to the actuating link 2 and the driving link 5 by an actuating link connecting pin 12 and a driving link connecting pin 13, respectively. In the embodiment, the connecting pins can be respectively provided with the bushings which are pressed in the corresponding pin holes, so that the abrasion of the connecting pins and the connecting rod structures is reduced.
When the variable compression ratio mechanism of the embodiment works, the eccentric shaft 6 in the variable compression ratio mechanism can be driven to rotate by a motor arranged on an engine cylinder body through a speed reducer, the rotation of the eccentric shaft 6 enables the supporting point of the driving connecting rod 5 to move up and down through the eccentric wheel 7, the change of the supporting point of the driving connecting rod 5 can change the upper dead point of the piston 1 through the linkage of the adjusting connecting rod 3 and the executing connecting rod 2, and therefore the adjustment of the compression ratio of the engine can be realized.
Further, in the variable compression ratio mechanism of the present embodiment, the pivot angle of the actuator connecting rod 2 is set to be less than 30 ° with the hinge shaft between the actuator connecting rod 2 and the piston 1, that is, the piston connecting pin 11, as the pivot center, and the pivot angle of the drive connecting rod 5 is set to be less than 27 ° with the eccentric 7 as the pivot center. By limiting the swing angle of the two connecting rods during working, the friction loss and the reciprocating inertia force of the connecting rods can be reduced, and the effect of reducing the abrasion of the connecting rods can be achieved.
Based on the above arrangement of the pivot angle, as an embodiment, referring to fig. 6 in combination with fig. 7, for each member of the variable compression ratio mechanism, taking the actuating link 2 that swings during operation as an example, the distance L1 between the centers of the hinge shafts at both ends of the actuating link 2, i.e., the distance between the center of the piston connecting pin 11 and the center of the actuating link connecting pin 12, the distance L2 between the center of the crankpin 14 and the center of the hinge shaft between the adjusting link 3 and the actuating link 2, i.e., the distance between the center of the crankpin 14 and the center of the actuating link connecting pin 12, the distance L3 between the center of the crankpin 14 and the center of the hinge shaft between the adjusting link 3 and the driving link 5, i.e., the distance between the center of the crankpin 14 and the center of the driving link connecting pin 13, and the distance L4 between the centers of the hinge shafts at both ends of the driving link 5, i.e., the distance between the driving link connecting pin 13 and the center of the eccentric 7, the four distances are set to satisfy L1/L3 ═ L4/L2.
Due to the arrangement of the relation, when the execution connecting rod 2 works, the included angle beta between the limit positions (2a and 2b) at two sides to which the execution connecting rod swings can be within 30 degrees, and the swinging angle of the execution connecting rod 2 is small, so that the friction loss of the execution connecting rod in swinging can be reduced, the inertia force of reciprocating swinging of the execution connecting rod can be reduced, and the purpose of reducing the abrasion is further achieved. When the above relation L1/L3 is not satisfied as L4/L2, the larger the deviation between L1/L3 and L4/L2 is, the larger the swing angle β of the actuating link 2 becomes, and at this time, the wear amount caused by the swing is greatly increased.
Similarly to the above-described setting of the swing angle of the actuating link 2, for the setting of the swing angle of the actuating link 5 which is also in the swing shape in operation, as a practical embodiment, this embodiment is combined with that shown in fig. 8, a distance L3 between the center of the crank pin 14 and the center of the hinge shaft between the adjusting link 3 and the actuating link 2, that is, a distance between the center of the crank pin 14 and the center of the actuating link connecting pin 13, a distance L4 between the centers of the hinge shafts at both ends of the actuating link 5, that is, a distance between the actuating link connecting pin 13 and the center of the eccentric 7, a distance L5 between the center of the eccentric 7 and the center of rotation of the crankshaft 4, and a distance r between the center of rotation of the crankshaft 4 and the center of the crank pin 14 are set to satisfy a value of (L42+ L32-r2)/L52 of 0.9-1.1.
At this time, the value of the expression (L42+ L32-r2)/L52 made up of the above distances may be, for example, 0.9, 0.95, 1.0, 1.02, 1.05, 1.08, or 1.1. The value of the expression is in the interval, so that the included angle alpha between the two limit positions (5a and 5b) to which the driving connecting rod 5 swings can be within 27 degrees when the driving connecting rod 5 works, the swinging angle of the driving connecting rod 5 is small, the friction loss of the driving connecting rod in swinging can be reduced, the inertia force of reciprocating swinging of the driving connecting rod can be reduced, and the purpose of reducing the abrasion is achieved. When the value of the above expression is not within the above numerical range, the more it exceeds the range, the larger the swing angle α of the drive link 5 becomes, and at this time, the amount of wear due to the swing is greatly increased.
The variable compression ratio mechanism of the present embodiment can reduce the friction loss and the reciprocating inertia force of the actuator link 2 and the drive link 5 during operation by limiting the swing angles of the two links, thereby reducing the wear thereof and improving the service life of the two link structures, and thus has excellent practicability.
Further, referring to fig. 6, the present embodiment also makes, for each member of the variable compression ratio mechanism, the distance L1 between the centers of the hinge shafts at both ends of the actuating link 2, i.e., the distance between the center of the piston connecting pin 11 and the center of the actuating link connecting pin 12, the distance L2 between the center of the crank pin 14 and the centers of the hinge shafts between the adjusting link 3 and the actuating link 2, i.e., the distance between the center of the crank pin 14 and the center of the hinge shaft between the actuating link 12, the distance L3 between the center of the crank pin 14 and the center of the hinge shaft between the adjusting link 3 and the driving link 5, i.e., the distance between the center of the crank pin 14 and the center of the driving link connecting pin 13, the distance L4 between the centers of the hinge shafts at both ends of the driving link 5, i.e., the distance between the center of the driving link connecting pin 13 and the center of the eccentric 7, and the perpendicular distance e between the center of the hinge shaft between the piston 1 and the actuating link 2 (i.e., the center of the piston connecting pin 11), the five distances are set such that when the movement locus of the center of the piston connecting pin 11 and the angle CA between the rotation center of the crankshaft 4 and the center connecting line of the crank pin 14 are 30 to 40 degrees, the center connecting line between the hinge shafts at both ends of the actuating link 2 is parallel or nearly parallel to the axis of the connecting member 8, that is, the bolt on the adjusting link 3.
Specifically, as shown in fig. 9, when the above-mentioned angle CA is 30 ° to 40 °, for example, 32 °, 35 °, 36.5 ° or 38 °, the crankshaft 4 in the engine is rotated until the fuel explosion pressure in the engine block is in the vicinity of the maximum value, at which time the above-mentioned distances L1, L2, L3, L4 and e make the line connecting the center of the piston connecting pin 11 and the center of the actuator connecting rod connecting pin 12 parallel or nearly parallel to the axis of the connecting member 8, that is, the angle a7+ a8 is equal to or nearly 90 °. Thus, when the cylinder explosion pressure is transmitted to the adjusting connecting rod 3 through the actuating connecting rod 2, because the actuating connecting rod 2 is parallel or nearly parallel to the bolt, the direction of the force FB transmitted to the adjusting connecting rod 3 is also parallel or nearly parallel to the bolt, so that the force applied to the bolt is mainly the force F7y along the axial direction of the bolt, and the tangential force F7x perpendicular to the axial direction of the bolt is smaller, thereby achieving the effect of avoiding the bolt from being damaged.
The angle a7 is an angle between a plane of the joint surface of the adjusting link 3 and a line connecting the center of the actuating link connecting pin 11 and the center of the actuating link connecting pin 12, and the angle A8 is an angle between a line connecting the center of the actuating link connecting pin 11 and the center of the actuating link connecting pin 12 and a line connecting the centers of the piston connecting pin 11 and the actuating link connecting pin 12.
In addition, when the crankshaft 4 rotates to make CA at an angle other than the above-mentioned 30 ° -40 ° interval, the deviation of the sum of the angles a7 and A8 from 90 ° is large, so that the direction of the force FB transmitted from the actuator connecting rod 2 to the adjuster connecting rod 3 is at an angle to the axial direction of the bolt, and can be decomposed into two force components in the axial direction and the tangential direction of the bolt (i.e., in the direction in which the joint surface M extends). In this case, the design of the engaging portion of the adjusting link 3, which is received at the joint surface M between the upper rod portion 301 and the lower rod portion 302, can share the component force transmitted to the joint surface between the upper rod portion 301 and the lower rod portion 302 through the positioning protrusion 3011, the positioning pin 9 or the positioning protrusion 101 on the positioning collar 10, so that the tangential force borne by the bolt can be reduced, and the purpose of avoiding the bolt from being damaged can be achieved.
The variable compression ratio mechanism of the embodiment can reduce the tangential force applied to the connecting piece 8 formed by the bolts by making the driving connecting rod 2 and the bolt axially parallel and arranging the occlusion part on the adjusting connecting rod 3 through the two designs, thereby avoiding the damage of the connecting piece 8, and selecting the bolts into smaller specifications, thereby having good practicability.
Example two
The present embodiment relates to a variable compression ratio engine that includes an engine block, and further includes a variable compression ratio mechanism as in the first embodiment provided in the engine block.
The engine of the present embodiment, by using the variable compression ratio mechanism of the first embodiment, can reduce the wear of the actuator link 2 and the drive link 5, and can improve the service life of the two link structures, thereby having excellent practicability.
The engine of the embodiment adopts the variable compression ratio mechanism in the first embodiment, so that the tangential force borne by the connecting piece formed by the bolt in the adjusting connecting rod can be reduced, the connecting piece can be prevented from being damaged, the connection reliability can be guaranteed, and the practicability is good.
EXAMPLE III
The present embodiment relates to an automobile including a variable compression ratio engine as in the second embodiment.
The above description is only exemplary of the present disclosure and should not be taken as limiting the disclosure, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present disclosure should be included in the scope of protection of the present disclosure.
Claims (15)
- A variable compression ratio mechanism comprises a piston (1) arranged in an engine cylinder in a sliding way, a crankshaft (4) arranged in the engine cylinder in a rotating way and an eccentric shaft (6) with an eccentric wheel (7), an adjusting connecting rod (3) arranged on a crank pin (14) in the crankshaft (4) in a rotating way, and an executing connecting rod (2) and a driving connecting rod (5) which are hinged at two ends of the adjusting connecting rod (3) and are respectively hinged with the piston (1) and the eccentric wheel (7); the method is characterized in that: the swinging angle of the execution connecting rod (2) is set to be lower than 30 degrees by taking a hinge shaft between the execution connecting rod (2) and the piston (1) as a swinging center, and the swinging angle of the driving connecting rod (5) is set to be smaller than 27 degrees by taking the eccentric wheel (7) as a swinging center.
- The variable compression ratio mechanism according to claim 1, characterized in that: a distance L1 between hinge shaft centers at both ends of the actuating link (2), a distance L2 between a center of the crank pin (14) and hinge shaft centers between the adjusting link (3) and the actuating link (2), a distance L3 between a center of the crank pin (14) and hinge shaft centers between the adjusting link (3) and the actuating link (5), and a distance L4 between hinge shaft centers at both ends of the actuating link (5) are set to satisfy the following relations: L1/L3 ═ L4/L2.
- The variable compression ratio mechanism according to claim 1, characterized in that: a distance L3 between the center of the crank pin (14) and the center of the hinge shaft between the adjusting link (3) and the driving link (5), a distance L4 between the centers of the hinge shafts at both ends of the driving link (5), a distance L5 between the center of the eccentric wheel and the center of the crank shaft, and a distance r between the center of the crank shaft and the center of the crank pin are set to satisfy a value of (L42+ L32-r2)/L52 of 0.9-1.1.
- The variable compression ratio mechanism according to claim 1, characterized in that: the piston (1) and the execution connecting rod (2), the driving connecting rod (5) and the adjusting connecting rod (3) are hinged through connecting pins.
- The variable compression ratio mechanism according to claim 4, characterized in that: and bushings which are pressed in the corresponding pin holes are respectively arranged at the connecting pins.
- The variable compression ratio mechanism according to any one of claims 1 to 5, characterized in that: the adjusting connecting rod (3) comprises an upper rod part (301) and a lower rod part (302) which are fixedly connected together through a connecting piece (8), a joint surface between the upper rod part (301) and the lower rod part (302) is orthogonal to the axis of the connecting piece (8), a mounting hole (303) for the crank pin (14) to pass through is formed between the upper rod part (301) and the lower rod part (302), and the connecting piece (8) is divided into two parts which are arranged on two opposite sides of the mounting hole (303).
- The variable compression ratio mechanism according to claim 6, characterized in that: the connecting piece (8) is a bolt.
- The variable compressor mechanism of claim 6, wherein: and the joint surface is provided with a meshing part which is used for forming mutual meshing between the upper rod part (301) and the lower rod part (302).
- The variable compression ratio mechanism according to claim 8, characterized in that: the occluding part comprises a positioning protrusion (3011) integrally constructed on the upper rod part (301) and a groove constructed on the lower rod part (302) corresponding to the positioning protrusion (3011), and the positioning protrusion (3011) is embedded in the groove.
- The variable compression ratio mechanism according to claim 8, characterized in that: the occlusion part comprises pin holes correspondingly arranged on the upper rod part (301) and the lower rod part (302), and positioning pins (9) with two ends respectively arranged in the pin holes on the upper rod part (301) and the lower rod part (302).
- The variable compression ratio mechanism according to claim 8, characterized in that: the occlusion part comprises a positioning groove, a positioning sleeve ring (10) and a positioning raised head (101), wherein the positioning groove is formed in the upper rod part (301) around the connecting piece (8), the positioning sleeve ring is embedded into the positioning groove and sleeved on the connecting piece (8), the positioning sleeve ring is provided with the positioning raised head (101), the positioning hole is formed in the lower rod part (302) around the connecting piece (8), the positioning hole is matched with the positioning raised head (101) and the positioning raised head (101) is embedded into the positioning hole.
- The variable compression ratio mechanism according to claim 6, characterized in that: the upper rod part (301) and the lower rod part (302) are formed by a powder forging process.
- The variable compression ratio mechanism according to claim 6, characterized in that: the vertical distance e between the motion track of the center of a hinge shaft between the piston (1) and the execution connecting rod (2) and the rotation center of the crankshaft (4) is set to be 30-40 degrees when the included angle CA between the motion track of the center of the hinge shaft between the piston (1) and the execution connecting rod (2) and the rotation center of the crankshaft (4) and the center connecting line of the crank pin (14) is 30-40 degrees, and the connecting line between the centers of the hinge shafts at two ends of the execution connecting rod (2) is parallel or close to parallel with the axis of the connecting piece (8).
- A variable compression ratio engine comprising an engine block, characterized in that: further comprising a variable compression ratio mechanism according to any one of claims 1 to 13 provided in the engine block.
- An automobile, characterized in that: comprising a variable compression ratio engine according to claim 14.
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811646189.6 | 2018-12-30 | ||
| CN201811646188.1A CN110671199B (en) | 2018-12-30 | 2018-12-30 | Variable compression ratio mechanism and engine |
| CN201811646188.1 | 2018-12-30 | ||
| CN201811646189.6A CN110657024A (en) | 2018-12-30 | 2018-12-30 | Variable compression ratio mechanism and engine |
| PCT/CN2019/129241 WO2020140843A1 (en) | 2018-12-30 | 2019-12-27 | Variable compression ratio mechanism, engine and automobile |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113795656A true CN113795656A (en) | 2021-12-14 |
| CN113795656B CN113795656B (en) | 2023-01-06 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201980087088.6A Active CN113795656B (en) | 2018-12-30 | 2019-12-27 | Variable compression ratio mechanism, engine and automobile |
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| Country | Link |
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| CN (1) | CN113795656B (en) |
| WO (1) | WO2020140843A1 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114893295B (en) * | 2022-05-25 | 2023-07-04 | 一汽解放汽车有限公司 | Engine connecting rod and engine |
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| JP4038959B2 (en) * | 2000-05-09 | 2008-01-30 | 日産自動車株式会社 | Variable compression ratio mechanism of internal combustion engine |
| JP4387770B2 (en) * | 2003-11-19 | 2009-12-24 | 日産自動車株式会社 | Internal combustion engine |
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- 2019-12-27 WO PCT/CN2019/129241 patent/WO2020140843A1/en active Application Filing
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| CN1512050A (en) * | 2002-12-27 | 2004-07-14 | 日产自动车株式会社 | IC engine having variable compression ratio mechanism and its control method |
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| CN113795656B (en) | 2023-01-06 |
| WO2020140843A1 (en) | 2020-07-09 |
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