CN106762196B

CN106762196B - Hydraulic motor driven variable compression ratio piston

Info

Publication number: CN106762196B
Application number: CN201710156279.6A
Authority: CN
Inventors: 苏岩; 朱振华; 解方喜; 郭淑芳; 王耀东; 邵珠杰; 石卜从; 赵海平; 冯爽; 于岐
Original assignee: Jilin University
Current assignee: Jilin University
Priority date: 2016-10-18
Filing date: 2017-03-16
Publication date: 2023-05-23
Anticipated expiration: 2037-03-16
Also published as: CN106481477A; CN106762196A

Abstract

The patent discloses a hydraulic motor driven variable compression ratio piston, which comprises a piston top, a piston skirt, a hydraulic motor mechanism, a rotating wheel, a speed reducing device and an inlet and outlet oil duct; the piston top and the piston skirt are respectively provided with a cavity, the hydraulic motor mechanism is arranged in the cavity of the piston skirt, the rotating wheel is arranged in the cavity of the piston top, four spiral plates on the rotating wheel are matched with four semicircular bulges on the piston top, the contact part between the hydraulic motor and the rotating wheel is a speed reducing device formed by matching a driving gear, a planetary gear and an internal gear, and the hydraulic motor is formed by a hydraulic base, a hydraulic blade, a hydraulic baffle plate, a sealing spring and an elliptic cavity of the piston skirt; the pressure oil enters the elliptical oil cavity from the oil duct, so that the hydraulic blade rotates to drive the rotating wheel to rotate, and under the action of the guide rod, the top of the piston moves relatively to the skirt part of the piston to change the compression ratio of the engine.

Description

Hydraulic motor driven variable compression ratio piston

Technical Field

The present invention relates to an engine piston for a vehicle, and more particularly, to a hydraulic motor-driven variable compression ratio piston.

Background

The compression ratio is the ratio of the total volume of the cylinder to the volume of the combustion chamber, and represents the degree to which the gas in the cylinder is compressed when the piston moves from the bottom dead center to the top dead center, and is an important parameter for measuring the performance of the engine, and is one of the most important factors affecting the efficiency of the engine. Generally, the higher the compression ratio, the better the engine performance. For a conventional engine, once designed, the compression ratio is fixed because the combustion chamber volume and the cylinder working volume are fixed parameters. The compression ratio of modern automobile engine is 8-12, diesel engine is 12-22.

The variable compression ratio technology is mainly one technology for supercharged engines. The fixed compression ratio does not fully exert the performance of the engine, and in fact, the thermal efficiency of the engine is low and accordingly the overall performance is relatively poor at low load and low speed operation, and a larger compression ratio can be used at this time, whereas at high load and high speed operation, knocking easily occurs and a large thermal load and mechanical load are generated if the compression ratio is too high, and a smaller compression ratio can be used at this time. The potential of the engine can be furthest excavated along with the change of the load by continuously adjusting the compression ratio, so that the heat efficiency is effectively improved in the whole working condition area, and the comprehensive performance of the engine is further improved.

The variable compression ratio technique can be used:

1. the heat efficiency of the engine is improved, and the fuel economy of the engine is improved to a great extent.

2. Is beneficial to reducing the emission.

3. Has good fuel adaptability.

4. Under the condition of the same output power, the structure can be more compact, and the low-displacement high-power and high-torque can be achieved.

5. The fuel economy at partial load and the dynamic performance at large load are both considered, and the knocking risk in the combustion process is avoided while the low-speed dynamic performance of the engine is improved.

6. The running stability can be improved to a certain extent, and the noise is reduced.

At present, the variable compression ratio of the domestic and foreign engines is generally complex in structure, the engine structure is generally required to be changed greatly, sometimes the processing is difficult, and the problem to be solved is how to simplify the mechanism to realize the ideal effect in a limited space; the newly added movable parts such as control and auxiliary mechanisms and the like cause the increase of vibration, friction loss and abrasion, and the increase of the mass of the engine, so that the movement of the large mass body needs to consume a great part of energy; the compression ratio of the engine is timely and accurately changed, corresponding high-precision control equipment is needed, and the matching difficulty is high; when the compression ratio is too high, the blow-by gas may consume power of the engine and cause malfunction of parts such as an engine body. If too much mixed gas leaks into the crankcase, the deterioration of lubricating oil can be caused; the research and development and manufacturing costs are high.

Disclosure of Invention

The invention aims to solve the technical problems of complex mechanism structure, more parts, poor manufacturability, high research and development cost and the like in the prior art, and provides a hydraulic motor driven variable compression ratio piston.

In order to solve the technical problems, the invention is realized by adopting the following technical scheme:

the hydraulic motor driven variable compression ratio piston is characterized in that the hydraulic motor driven variable compression ratio piston divides a piston of a traditional internal combustion engine into a piston top part and a piston skirt part; eight seal springs are arranged in round holes of the hydraulic base, eight hydraulic blades are arranged in rectangular holes of the hydraulic base, the hydraulic blades are in contact with the seal springs, the part fastening springs, the seal springs and the hydraulic base are assembled into a hydraulic rotating mechanism and are arranged in round grooves of the piston skirt, a hydraulic baffle plate is covered on the hydraulic rotating mechanism, and the part hydraulic base, the hydraulic blades, the hydraulic baffle plate, the seal springs and an elliptic cavity of the piston skirt are assembled to form a hydraulic motor; inserting the spline into a spline hole of the hydraulic base; the rotating wheel is decelerated and torque is increased through a gear deceleration mechanism, a ball bearing is placed on the side face of a boss of the rotating wheel, the rotating wheel is fixed on the freedom degree of motion around an axis through two end covers, an arch hole on the end cover is penetrated by a circular hole fixing seat of a hydraulic baffle, and then a clamping ring is placed in a clamping ring groove of a piston skirt part to fix the end covers; the piston top is placed on the piston skirt, a columnar rod at the piston top is inserted into a circular hole fixing seat of the hydraulic baffle plate to guide the piston top, and a semicircular bulge at the piston top is in line contact with a spiral plate on the rotating wheel.

The center of the breaking surface of the top of the piston is a large cavity, four columnar rods uniformly extend out of the periphery of the bottom surface of the cavity, and a semicircular bulge is arranged inwards at the middle position of each columnar rod.

The center of the breaking surface of the piston skirt is provided with a circular cavity, the side surface of the cavity is provided with a circle of snap ring groove, the bottom surface of the cavity is provided with a large oval hole, the bottom surface of the oval hole is also provided with a circular groove for placing a hydraulic base, the left side and the right side of a pin hole at the piston skirt are respectively provided with an oil duct in an upward drilling mode, the lengths of the left oil duct and the right oil duct are different, the terminals of the two oil ducts extend along the edge of the oval hole in the horizontal direction in an arc of 30 degrees and 150 degrees, and then enter the oval hole.

The rotating wheel is of a cylindrical structure, four spiral plates are uniformly distributed on the outer side of the cylinder, a cylindrical body is arranged on the base of the cylinder, a circular boss is arranged at the bottom of the cylindrical body and used for fixing the circular wheel, and an inner gear is drilled on the inner face of the boss.

The speed reducing mechanism is formed by respectively and simultaneously externally meshing three planetary gears with a driving gear and internally meshing the three planetary gears with an internal gear in a boss of the rotating wheel.

The main body of the hydraulic blade is a rectangular body, round corners are rounded, and a cylindrical support rod is arranged on the end face of the rectangular body.

The hydraulic base is of a cylindrical structure, a spline hole is drilled in the middle of the upper end face of the cylinder, eight rectangular openings are uniformly distributed on the side face of the cylinder, and round holes are drilled in the inner side face of the rectangular hole horizontally.

The hydraulic baffle is of a circular plate-shaped structure, a circular hole is formed in the middle of the circular plate, and four circular hole-shaped fixing seats are distributed around the circular plate.

The side surface of the hydraulic blade is tightly contacted with the side surface of the elliptical hole of the piston skirt, and a certain pre-pressure exists between the contact surfaces of the hydraulic blade and the elliptical hole of the piston skirt due to the pre-tightening force of the sealing spring applied on the hydraulic blade.

Compared with the prior art, the invention has the beneficial effects that:

1. the invention only processes the inside of the piston and adds corresponding parts and a set of hydraulic control system, without changing the integral structure of the cylinder, so that the mechanism structure is simple.

2. The invention uses the rotation of the hydraulic motor as the driving force, and has compact structure, smaller outline size, low noise and long service life.

3. After the torque provided by the hydraulic motor is applied, the compression ratio is changed through the spiral matching between the rotating wheel and the top of the piston, and the hydraulic motor is reliable in operation.

4. The invention has low manufacturing cost because of few processing parts and the reprocessing of the piston.

Drawings

The invention is further described below with reference to the accompanying drawings:

fig. 1 is a front cross-sectional view of a hydraulic motor driven variable compression ratio piston according to the present invention.

Fig. 2 is a C-C projection view shown in fig. 1.

Fig. 3 is a D-D projection view shown in fig. 1.

Fig. 4 is an E-E projection view shown in fig. 1.

Fig. 5 is an oblique view of the assembly of the present invention with the piston crown removed.

Fig. 6 is a front view of a rotor component of the present invention.

Fig. 7 is a top view of a rotor component of the present invention.

Fig. 8 is a front view of a piston top part of the present invention.

Fig. 9 is a B-B projection view of the front view of fig. 8.

Fig. 10 is a front view of the hydraulic vane.

Fig. 11 is a left side view of the hydraulic vane.

Fig. 12 is a front view of the hydraulic mount.

Fig. 13 is an A-A projection view of the front view of fig. 12.

Fig. 14 is a front cross-sectional view of the piston skirt.

Fig. 15 is a B-B projection view of the main section of fig. 14.

FIG. 16 is a C-C projection view of the main section of FIG. 14.

In the figure: the hydraulic piston comprises a piston top, a 2-fastening spring, a 3-rotating wheel, a 4-clamping ring, a 5-end cover, a 6-ball bearing, a 7-hydraulic baffle, 8-hydraulic blades, 9-sealing springs, a 10-piston skirt, 11-splines, 12-hydraulic bases, 13-planetary gears and 14-driving gears.

Detailed description of the preferred embodiments

The invention is described in detail below with reference to the attached drawing figures:

referring to fig. 1 and 2, the piston is divided into two parts of a piston top 1 and a piston skirt 10 along a breaking plane, a hydraulic motor, a speed reducing mechanism and a rotating wheel 3 are assembled in a cavity formed by the two parts, two oil passages are drilled in the piston skirt 10 to provide an inlet and outlet oil passage for the hydraulic motor, and connecting rods are arranged in four round holes at the edge of the breaking plane of the piston top 1 and used for connecting a fastening spring 2.

Referring to fig. 8 and 9, the center of the partial section of the piston top 1 is a large cavity, four columnar bars are uniformly distributed around the bottom of the cavity, each columnar bar is provided with a semicircular protrusion, and the protrusions are inward in direction and in line contact with the spiral plate of the rotating wheel through the semicircular protrusions, so that the piston top 1 can move relative to the piston skirt 10.

Referring to fig. 14, 15 and 16, the center of the breaking surface of the piston skirt 10 is a large cavity, a circle of snap ring grooves are drilled at the upper part of the side surface of the cavity, the shape of the cavity is a circular cavity, the lower surface of the circular cavity is an elliptical hole, the elliptical long axis is equal to the radius of the cavity of the piston top 1, a circular groove is drilled at the bottom surface of the elliptical hole of the piston skirt 10, the circular groove is used for fixing the hydraulic base 12, four arch holes corresponding to the piston top 1 are uniformly distributed at the edge of the breaking surface of the piston skirt 10, and connecting rods are also arranged in the arch holes; left and right oil channels are drilled on the left and right sides of a pin hole of the piston skirt 10 along the direction of the axis of the piston, the lengths of the two oil channels are different, the terminal end of the left oil channel extends along the edge of an elliptical hole at 30 degrees and 150 degrees in the horizontal direction and then enters the elliptical hole, and similarly, the terminal end of the right oil channel extends along the edge of the elliptical hole at the opposite directions at 30 degrees and 150 degrees in the horizontal direction and then enters the elliptical hole.

Referring to fig. 1 and 2, the hydraulic baffle 7 is a circular plate structure, a circular hole is formed in the middle of the circular plate, and four circular hole-shaped fixing seats are distributed around the circular plate.

Referring to fig. 6 and 7, the rotating wheel 3 is a cylindrical structure, four spiral plate-shaped structures are distributed on the outer side of the cylinder, a column body is arranged at the bottom of the cylinder, a circular boss is arranged at the bottom of the column body and used for fixing the rotating wheel 3, and an inner gear is arranged on the inner side of the boss.

Referring to fig. 10 and 11, the main body of the hydraulic blade 8 is a rectangular body, rounded corners are formed, and a cylindrical support rod is arranged on the end surface of the rectangular body.

Referring to fig. 12 and 13, the hydraulic base 12 is a cylindrical structure, a spline hole is drilled in the center of the cylinder, eight cuboid openings are uniformly distributed on the side surface of the cylinder facing the axis of the cylinder, the opening surface of the cuboid opening is flush with the end surface of the cylinder, and a round hole is drilled on one surface in the cuboid for mounting a sealing spring.

Referring to fig. 1, 2 and 5, the seal spring 9 is placed in the circular hole of the hydraulic base 12, then the cylindrical parts of the eight hydraulic blades 8 are inserted into the circular hole of the hydraulic base 12, the

parts

8, 9 and 12 form a hydraulic rotating mechanism, the above hydraulic rotating mechanism is placed on the circular hole of the bottom surface of the elliptical hole of the piston skirt 10 through the hydraulic base 12, the parts hydraulic base 12, the hydraulic blades 8, the hydraulic baffle 7, the seal spring 9 and the elliptical cavity of the piston skirt 10 are assembled to form a hydraulic motor, the side surfaces of the eight hydraulic blades 8 are contacted with the elliptical Kong Cemian of the piston skirt 10, and a certain pretightening force is arranged between the contact surfaces through the seal spring 9. Placing a hydraulic baffle 7 on the upper part of the hydraulic rotating mechanism, wherein the side surface of the hydraulic baffle 7 is in interference fit with a piston skirt 10; the spline 11 is inserted into a spline hole of the hydraulic base 12, a driving gear 14 is arranged at the upper end of the spline 11, three planetary gears 13 are uniformly distributed between the driving gear 14 and an internal gear on the rotating wheel 3, the planetary gears 13 are externally meshed with the driving gear 14, the three planetary gears 13 are internally meshed with the internal gear on the rotating wheel 3, the inner circular surface of the ball bearing 6 is contacted with the side surface of a boss of the rotating wheel 3, two end covers 5 are placed on the hydraulic baffle 7 and compress the rotating wheel 3 by using the lower end surface of the end cover 5, and an arch hole of the end cover 5 penetrates through a round hole fixing seat of the hydraulic baffle 7 and fixes the end cover 5 by using the clamping ring 4; four columnar rods of the piston top 1 are placed in a circular hole fixing seat of the hydraulic baffle 7 and are matched into clearance fit, a semicircular convex structure on the columnar rods is in line contact with a spiral plate on the rotating wheel 3, a parting plane of the piston top 1 is overlapped with a parting plane of the piston skirt 10, then the piston top 1 is connected with the piston skirt 10 through four fastening springs 2 by connecting rods, and uncontrolled relative movement of the piston top 1 and the piston skirt 10 due to inertia force and air pressure in a severe movement process of the piston is prevented.

Referring to fig. 1, 3, 4 and 14, when the engine needs high compression ratio, the hydraulic pump guides hydraulic oil to the left oil duct at the pin hole of the piston skirt 10 through the crankshaft and connecting rod oil path, then the hydraulic oil flows upwards along the axis direction of the piston and horizontally flows into the oval cavity along 30 degrees and 150 degrees, the area of the oil cavity in the oil inlet cavity is larger than the area of the oil outlet cavity, the pressure of the oil inlet cavity is larger than the pressure of the oil outlet cavity, so that the hydraulic blade 8 rotates positively, the driving gear 14 is driven by the spline 11 to rotate positively, at the moment, the rotation speed of the driving gear 14 is high, the torque is small, the rotation speed of the rotating wheel 3 is small through the speed reducing and torque increasing effect of the planetary gear 13, the torque is increased, the rotating wheel 3 overcomes the pretightening force effect of the fastening spring 2 through the guiding effect of the round hole fixing seat on the hydraulic baffle 7 and increases relative to the distance of the piston skirt 10, and the compression ratio is increased.

Referring to fig. 1, 3, 4 and 14, when the engine needs low compression ratio, the hydraulic pump guides hydraulic oil to the right oil duct at the pin hole of the piston skirt 10 through the crankshaft and connecting rod oil path, then the hydraulic oil flows upwards from the right oil duct at the pin hole of the piston skirt 10 and flows into the oval cavity along 30 degrees and 150 degrees horizontally, at this time, the pressure of the oil outlet cavity is greater than the pressure in the oil inlet cavity, so the hydraulic vane 8 reverses, the hydraulic vane 8 drives through the driving gear 14, the planetary gear 13 decelerates and increases torsion, torque is transmitted to the rotating wheel 3, the rotating wheel 3 reverses, the distance between the piston top 1 and the piston skirt 10 is reduced under the pretightening force of the fastening spring, and the engine has low compression ratio at this time.

Claims

1. The hydraulic motor driving type variable compression ratio piston is characterized by comprising a piston top (1), a fastening spring (2), a rotating wheel (3), a clamping ring (4), an end cover (5), a ball bearing (6), a hydraulic baffle plate (7), a hydraulic blade (8), a sealing spring (9), a piston skirt (10), a spline (11), a hydraulic base (12), a planetary gear (13) and a driving gear (14);

the traditional internal combustion engine piston is divided into a piston top (1) and a piston skirt (10); eight sealing springs (9) are placed in round holes of a hydraulic base (12), eight hydraulic blades (8) are placed in rectangular holes of the hydraulic base (12), the hydraulic blades (8) are in contact with the sealing springs (9), the part fastening springs (2), the sealing springs (9) and the hydraulic base (12) are assembled into a hydraulic rotating mechanism and are installed in round grooves of a piston skirt (10), a hydraulic baffle plate (7) covers the hydraulic rotating mechanism, and oval cavities of the part hydraulic base (12), the hydraulic blades (8), the hydraulic baffle plate (7), the sealing springs (9) and the piston skirt (10) are assembled to form a hydraulic motor; inserting the spline (11) into a spline hole of the hydraulic base (12); the rotating wheel (3) is decelerated and torque is increased through a gear deceleration mechanism, a ball bearing (6) is placed on the side face of a boss of the rotating wheel (3), the rotating wheel (3) is fixed on the freedom degree of motion around an axis through two end covers (5), an arch hole on the end cover (5) is penetrated by a circular hole fixing seat of a hydraulic baffle plate (7), and then a clamping ring (4) is placed in a clamping ring groove of a piston skirt (10) to fix the end covers (5); the piston top (1) is placed on the piston skirt (10), a columnar rod of the piston top (1) is inserted into a circular hole fixing seat of the hydraulic baffle (7) to guide the piston top (1), and a semicircular bulge of the piston top (1) is in line contact with a spiral plate on the rotating wheel (3).

2. The hydraulic motor driving type variable compression ratio piston according to claim 1, wherein the center of the breaking surface of the piston top (1) is a large cavity, four columnar bars uniformly extend out of the periphery of the bottom surface of the cavity, and a semicircular bulge is arranged inwards at the middle position of each columnar bar.

3. The piston of claim 1, wherein the piston skirt (10) has a circular cavity drilled in the center of the parting plane, a ring of snap ring grooves are formed on the side surface of the cavity, a large oval hole is drilled on the bottom surface of the cavity, a circular groove is drilled on the bottom surface of the oval hole for placing the hydraulic base (12), an oil passage is drilled on the left and right sides of the pin hole at the piston skirt (10), the lengths of the left and right oil passages are different, and the terminal ends of the two oil passages extend along the edge of the oval hole in the horizontal direction at an arc of 30 degrees and 150 degrees and then enter the oval hole.

4. The hydraulic motor driven variable compression ratio piston according to claim 1, wherein the rotating wheel (3) is of a cylindrical structure, four spiral plates are uniformly distributed on the outer side of the cylinder, a cylindrical body is arranged on the base of the cylinder, a circular boss is arranged at the bottom of the cylindrical body and used for fixing the rotating wheel (3), and an inner gear is drilled on the end face of the boss.

5. The hydraulic motor driven variable compression ratio piston according to claim 1, wherein the speed reducing mechanism is formed by externally engaging three planetary gears (13) with a driving gear (14) respectively and internally engaging with an internal gear in a boss of the rotating wheel (3).

6. A hydraulic motor driven variable compression ratio piston according to claim 1, characterized in that the body of the hydraulic vane (8) is a rectangular body with rounded corners and a cylindrical support bar at the end face of the rectangular body.

7. The hydraulic motor driven variable compression ratio piston according to claim 1, wherein the hydraulic base (12) is of a cylindrical structure, a spline hole is drilled in the middle of the upper end face of the cylinder, eight rectangular openings are uniformly distributed on the side face of the cylinder, and round holes are drilled in the inner side face of the rectangular hole horizontally.

8. The hydraulic motor driven variable compression ratio piston according to claim 1, wherein the hydraulic baffle (7) is a circular plate-shaped structure, the middle of the circular plate is a circular hole, and four circular hole-shaped fixing seats are distributed around the circular plate.

9. The hydraulic motor driven variable compression ratio piston according to claim 1, wherein the side surface of the hydraulic vane (8) is in close contact with the side surface of the elliptical hole of the piston skirt (10), and a certain pretightening force exists between the contact surfaces of the hydraulic vane (8) and the elliptical hole of the piston skirt (10) due to pretightening force exerted on the hydraulic vane (8) by the sealing spring (9).