CN205315119U - Variable compression compares piston - Google Patents

Abstract

The utility model discloses a variable compression compares piston, including piston upper part of the body, the piston lower part of the body, locking round pin, reed and motor driver, its characterized in that: motor stator fixes on the motor cabinet at endotheca center, the endotheca is connected with the piston lower part of the body through the boss and is fixed under the restraint of snap ring, there is fixed circle wheel structure the electric motor rotor upper end, has connecting device to be used for connecting the reed tail end around the circle wheel structure, the periphery of endotheca is another ring of columniform key seat, and key seat upper portion has four pinholes to be used for installing locking round pin, and the round pin head of locking round pin is month tooth structure and cooperatees with the locking groove of piston upper part of the body inner wall that the round pin tail of locking round pin passes through the connecting hole with the head end of reed and is connected, the spring mounting is between the pinhole of the pinhole of locking round pin and endotheca, and the return that plays the twin lock shotpin acts on. The utility model discloses few, the simple structure of part for the engine all has good dynamic property and fuel economy under different work condition.

Description

A kind of variable compression ratio piston

Technical field

The invention belongs to a kind of piston of automobile engine, say it is the piston of a kind of variable compression ratio more specifically.

Background technology

Compression ratio is the ratio of the maximum volume of cylinder when lower dead center with cylinder minimum volume when top dead center, the words that compression ratio is big, when compression ends, mixture pressure and temperature are more high, rate of combustion speeds, and thus the efficiency of combustion of engine can improve, but the compression ratio of engine can not be too high, because for petrol motor, the words that compression ratio is high can produce pinking, and for reducing the impact that pinking brings to engine, this kind of problem seems particularly outstanding in the design of engine with supercharger. Fixing compression ratio becomes a very important factor of restriction mechanical supercharging and turbosupercharged engine. It is known that after turbo-charging gets involved, the temperature of combustion chamber and pressure can significantly raise, if this value is too high, pinking is just inevitable. Engine can be produced huge injury by this, also can affect Power output simultaneously. So, turbo-charging and the mechanically-sapercharged engine of fixing compression ratio can only design more much lower than common natural aspirated engine compression ratio. But this kind of too low compression ratio design, can cause again engine when particularly turbo-charging does not get involved completely, and efficiency of combustion is very low, much fewer than the power that common natural aspirated engine produces of the power that can produce. This contradiction is the major reason impelling Designers to develop variable compression ratio engine.

The object of variable compression ratio is to improve the fuel economy of engine with supercharger. In engine with supercharger, in order to prevent pinking. its compression ratio is lower than naturally aspirated engine. When low pressure, thermo-efficiency reduces. and fuel economy is declined. Special in turbosupercharged engine due to degree of supercharging rise slowly when low compression ratio moment of torsion rise also very slow. form so-called supercharging hysteresis phenomenon. That is, engine is when low speed, and supercharging is delayed. wait until engine accelerate to certain rotating speed after supercharging system just play a role.In order to address this problem, variable compression ratio is important method. In other words. the running on the lower load at low pressure makes compression ratio bring up to identical with naturally aspirated engine compression ratio or exceed: on the other hand. under the high loading operating mode of high pressure charging, suitably reduce compression ratio. In other words, along with the change of load regulates compression ratio continuously. thermo-efficiency can be improved from underload in high whole condition range.

The compression ratio of general engine is immutable, because combustion volume and actual displacement are all fixing parameters, reserves in the design. But, in order to make modern engine function play better efficiency in the operating mode of various change, by installing additional, some machinery assemblies make engine be changed the compression ratio of engine in operational process by the control of ECU to planners.

But there is Railway Project in variable compression ratio engine technology at present. It mainly contains the change that cylinder head has carried out a large amount of complexity, manufacturing cost is increased greatly, the mechanical assembly having installed large amount of complex additional makes reliability reduce, cost increases, in addition changeable compression ratio technique realize it is necessary to have the relative movement each other of two components, so can sealing problem be the critical problem causing variable compressive realize, above variety of problems result in the restriction of changeable compression ratio technique.

Summary of the invention

Technical problem to be solved by this invention is for above-mentioned problem, providing a kind of variable compression ratio piston, it changes, by the relative position changed between piston top and connecting rod, dynamic property, the fuel economy that engine compression ratio makes engine all have under different load operating mode.

For solving the problems of the technologies described above, the present invention adopts following technical scheme to realize:

A kind of variable compression ratio piston, comprises piston upper body, piston lower body, lock shotpin, spring, reed and motor drive unit, it is characterised in that:

Described motor stator is fixed on the motor seat at inner sleeve center, inner sleeve is fixed on piston lower body by snap ring, there is fixing round wheel construction spring fitting inner sleeve between the lock groove of shotpin and the pin-and-hole of inner sleeve motor rotor upper end that is connected with piston lower body, coupling device is had to be used for connecting reed tail end around circle wheel construction, the pin tail of the first end traction lock shotpin of reed, inner sleeve is connected with piston lower body and fixes under the constraint of snap ring, and piston upper body is connected by guide plate with piston lower body.

The periphery of described inner sleeve is that another encloses cylindrical key seat, four equally distributed pin-and-holes are arranged at key seat top, the plunger of lock shotpin is that cross section is trapezoidal arc structure and lock groove with piston upper body inwall matches, the pin tail of lock shotpin is that shaft-like shape structure connects in hole by being connected with the first end of reed, has four equally distributed boss at the bottom of the seat of inner sleeve.

Described piston upper body divides section part to have four equally distributed guiding holes, and the inwall place of piston upper body has upper and lower two circle cross sections to be trapezoidal lock groove.

Described piston lower body divides section to be cast with four equally distributed guide plates to be inserted in four corresponding equally distributed guiding holes of piston upper body, piston lower body bottom surface has four recessed holes of truncated cone-shaped.

Described reed is the elastic metallic structure that head and the tail have coupling device.

Compared with prior art the invention has the beneficial effects as follows:

1. adopt motor-driven mode to make mechanical movement more reliable.

2. make use of the pressure of working medium in the mass force of piston and cylinder to promote being separated from each other and combination of piston space, reduce the driving power of motor greatly so that the control strategy installing electric machine at internal piston additional becomes possibility.

3., owing to only changing in piston body, do not relate to the cylinder head even change of engine entirety so that the good manufacturability of this invention.

4. mechanical component quantity owing to installing additional is few, and portion parts belongs to supporting part ripe on standardized component and market, so the cost of this invention is low.

5., owing to connecting motor rotor and lock shotpin with reed, reed plays shock absorption so that the tolerance range of motor is required by the present invention can not be too high.

Relative deficiency part of the present invention is to be used for the compression ratio of two-stage variable and can not be used for electrodeless variable compression ratio engine.

Accompanying drawing explanation

Fig. 1 is the main sectional view of piston component.

Fig. 2 is the oblique drawing of internal piston.

Fig. 3 is the main sectional view of motor seat part.

Fig. 4 is the A-A projection view that motor seat part master analyses and observe.

Fig. 5 is the front view of lock shotpin.

Fig. 6 is the vertical view of lock shotpin.

In figure: piston upper body 1, lock shotpin 2, inner sleeve 3, snap ring 4, reed 5, spring 6, motor (motor rotor 7, motor stator 8), piston lower body 9.

Embodiment

Below in conjunction with accompanying drawing, the present invention is described in detail

As shown in Figure 1, Figure 2, whole piston is divided into piston upper body 1 and piston lower body 9 two parts, the bottom surface periphery of piston upper body 1 has four fan-shaped guiding holes, inwall has the two trapezoidal lock grooves of circle, the end face of piston lower body 9 has four fan-shaped guide plates corresponding with the guiding hole of piston upper body 1, and base is cast with four conical recessed holes.

Such as Fig. 5, Fig. 6, lock shotpin 2 is cylindrical part, before be cast with the circular arc plunger that cross section is trapezoidal enclose with the inwall two of piston upper body 1 trapezoidal lock groove match after have the rigid stick shape pin tail of cylindrical cross-section for being connected reed 5.

Such as Fig. 3, Fig. 4, the bottom of inner sleeve 3 has four recessed holes of cone of four conical boss and piston lower body 9 to match the rotation of incompatible restriction inner sleeve 3 on axis direction, the center of inner sleeve 3 is that cylindrical electrical machine seat is used for fixing motor stator 8, the periphery of inner sleeve 3 is that another encloses cylindrical key seat, and key seat top has four pin-and-holes to be used for installing lock shotpin 2 and spring 6.

Snap ring 4 is the rigidity structure that the circular arc not overlapped by the inside and outside center of circle is formed, and has certain elasticity, for preventing inner sleeve 3 to be shifted, plays maintenance, stable.

Such as Fig. 2, reed 5 is four elastic steel disc compositions, plays buffering, the effect of the pin tail of traction lock shotpin 2, and there is connection hole reed 5 two ends, and first end connects the pin tail of lock shotpin 2, and tail end connects motor rotor 7.

Such as Fig. 1,2, motor is divided into motor stator 8 and motor rotor 7, and motor stator 8 is fixed in inner sleeve 3, and motor rotor 7 rotates, and there is fixing round wheel construction motor rotor 7 upper end, has four coupling devices to be used for connecting reed 6 around circle wheel construction.

Between the pin-and-hole that spring 6 is arranged on lock shotpin 2 and the pin-and-hole of inner sleeve 3, play a part lock shotpin 2 times positions.

If when engine needs low compression ratio, in breathing process, connecting rod pulls piston that piston is moved to lower dead center by top dead center, the plunger of lock shotpin 2 is in the lower lock groove of piston upper body 1, now cylinder interior gas pressure is very little and close to barometric point so ignore, when piston is close to lower dead center, now motor rotor 7 rotates, band movable contact spring 5 tightens, reed 5 Strain lock shotpin 2 is separated with the lower lock groove of piston upper body 1 and spring 6 is in compressed state, now without any being connected between piston upper body 1 with piston lower body 9, at lower dead center place, piston lower body 9 moves to contrary direction owing to being subject to the effect of connecting rod, move to former direction due to the effect of mass force in piston upper body 1, therefore piston upper body 1 reduces with the relative distance of piston lower body 9, when the upper lock groove of piston upper body 1 just aligns with lock shotpin 2 plunger, motor stopping work, the plunger now locking shotpin 2 is under the effect of compression spring 6, in insertion in lock groove, under now engine operates in low compression ratio operating mode.

If when engine needs high compression ratio, in exhaust process, connecting rod pulls piston that piston is moved to top dead center by lower dead center, the plunger of lock shotpin 2 is in the upper lock groove of piston upper body 1, now cylinder interior gas pressure slightly larger than barometric point so ignore, when the piston is near the top dead centre, now motor rotor 7 rotates, band movable contact spring 5 tightens, reed 5 taut wire line makes lock shotpin 2 be separated with the upper lock groove of piston upper body 1 and spring 6 is in compressed state, now without any being connected between piston upper body 1 with piston lower body 9, at top dead center place, piston lower body 9 moves to contrary direction owing to being subject to the effect of connecting rod, move to former direction due to the effect of mass force in piston upper body 1, therefore piston upper body 1 increases with the relative distance of piston lower body 9, when the lower lock groove of piston upper body 1 just aligns with lock shotpin 2 plunger, motor stopping work, the plunger now locking shotpin 2 is under the effect of compression spring 6, in insertion in lock groove, under now engine operates in high compression ratio operating mode.

Claims (5)

1. a variable compression ratio piston, comprise piston upper body (1), piston lower body (9), lock shotpin (2), spring (6), reed (5) and motor drive unit, it is characterized in that: described motor stator (8) is fixed on the motor seat at inner sleeve (3) center, inner sleeve (3) is fixed on piston lower body (9) by snap ring (4), spring (6) is arranged between the groove of lock shotpin (2) and the pin-and-hole of inner sleeve (3) inner sleeve (3) motor rotor (7) upper end that is connected with piston lower body (9) fixing round wheel construction, coupling device is had to be used for connecting reed (5) tail end around circle wheel construction, the pin tail of first end traction lock shotpin (2) of reed (5), inner sleeve (3) is connected with piston lower body (9) and fixes under the constraint of snap ring (4), piston upper body (1) is connected by guide plate with piston lower body (9).

2. a kind of variable compression ratio piston according to claim 1, it is characterized in that: the periphery of described inner sleeve (3) is that another encloses cylindrical key seat, four equally distributed pin-and-holes are arranged at key seat top, the plunger of lock shotpin (2) is that cross section is trapezoidal arc structure and lock groove with piston upper body (1) inwall matches, the pin tail of lock shotpin (2) is that shaft-like shape structure connects in hole by being connected with the first end of reed (5), has four equally distributed boss at the bottom of the seat of inner sleeve (3).

3. a kind of variable compression ratio piston according to claim 1, it is characterized in that: described piston upper body (1) point section part has four equally distributed guiding holes, the inwall place of piston upper body (1) has upper and lower two circle cross sections to be trapezoidal lock groove.

4. a kind of variable compression ratio piston according to claim 1, it is characterized in that: described piston lower body (9) point section is cast with four equally distributed guide plates and is inserted in four corresponding equally distributed guiding holes of piston upper body (1), and piston lower body (9) bottom surface has four recessed holes of truncated cone-shaped.

5. a kind of variable compression ratio piston according to claim 1, it is characterised in that: described reed (5) be the elastic metallic structure having coupling device from beginning to end.