CN205977444U - Piston structure - Google Patents

Abstract

The utility model discloses a piston structure, top land have " U " shape boss, should form the pit in " U " shape region that the boss enclosed, and the place ahead of " U " shape boss open end is equipped with two (air) intake valves and dodges the hole, and the rear side of " U " shape boss blind end is equipped with two exhaust valves and dodges the hole, sets up the ring channel in the periphery of " U " shape boss, and the hole is dodged to this ring channel and (air) intake valve and the hole intercommunication is dodged to the exhaust valve. The utility model discloses a this structure can reach ideal pressure scaling when avoiding the knockings to appear effectively, improved under the condition that does not change air intake system and rolled the flow ratio, change piston combustion chamber and spark plug interval, caused near spark plug to more gas mixtures, realized the best gas mixture in spark plug position, the pit has increased valve and piston clearance, for changing the valve lift headspace, makes VVT slew range wider, the utility model discloses effectively increasing the heat efficiency and the economic nature of engine are avoided the deformation of piston pin hole and are pulled.

Description

Piston structure

Technical field

This utility model belongs to technical field of internal combustion engines, specifically, particularly to a kind of piston structure.

Background technology

Piston is one of critical component of electromotor, and its Main Function is subject to the gas pressure in cylinder, and by this Pressure passes to connecting rod by piston pin, to promote bent axle to rotate.Top land and cylinder head, cylinder wall collectively constitute combustor, Therefore piston-shaped design has direct relation with combustion-chamber shape and compression ratio, and it directly affects the indoor vortex of burning, rolling The formation of stream and burning and intensity.

Existing small-displacement gasoline engine, mostly adopts flat-head piston, and manufacturing process is simple, but has that endotherm area is little, pressure Contracting cannot form, than in less than normal, cylinder, the shortcomings of move compared with high current field, extend burning time, reduce the constant volume degree of burning, make The thermal efficiency obtaining electromotor is low.Good Combustion chamber design can make full use of compression and when change the raising of gaseous mixture Tumble and swirl Motivation efficiency of combustion, thus improve the performance of electromotor.

The atmospheric pressure that piston is born in advance passes to connecting rod by piston pin and piston boss, but the total bearing area of piston pin Limited, so, the surface pressure between piston pin and key seat is very high, and the relative velocity between piston pin and key seat is very low in addition, Hydrodynamic lubrication oil film is difficult to be formed, and easily causes pulling of pin-and-hole, when piston is worked with piston pin, flexural deformation is mutually inharmonious, can Pin-and-hole deformation even key seat cracking can be caused, piston lubrication technique needs constantly to explore and improves.

Piston for IC engine service life be typically service life of aeroengine bottleneck, how to design a high efficiency and The piston for IC engine of durable, and then the raising efficiency of internal combustion engine and the big problem that performance is engine art.

Utility model content

In view of the above-mentioned deficiency of prior art, technical problem to be solved in the utility model is to provide a kind of new work Plug structure.

Technical solutions of the utility model are as follows：A kind of piston structure, including top land, piston skirt, piston pin Seat and piston pin hole it is characterised in that：Described top land has " u "-shaped boss, and this " u "-shaped boss area defined is formed Pit, the bottom surface of pit is inclined-plane, and the medial wall of pit is to pass through fillet mistake between scalene cone, and the bottom surface of pit and medial wall Cross, be provided with two symmetrical inlet valves in the front at described " u "-shaped boss openings end and avoid hole, " u "-shaped boss blind end Rear side be provided with two symmetrical exhaust valves and avoid hole, in the periphery setting cannelure of described " u "-shaped boss, this cannelure Avoid hole with inlet valve and exhaust valve avoids hole and connects, the region that described top land is located at cannelure periphery is avoided by inlet valve Hole and exhaust valve avoid hole and are separated into four planes, the respectively first plane, the second plane, the 3rd plane and fourth plane.

Using above technical scheme, top land arranges pit, and the bottom surface of pit is inclined-plane, and the medial wall of pit is oblique cone Pass through round-corner transition, this is designed with and forms strong extruding in cylinder beneficial to gaseous mixture between face, and the bottom surface of pit and medial wall Flowing, and then accelerate the burning velocity of combustion mixture in cylinder, improve engine thermal efficiency." u "-shaped boss effectively increases Top land area, its endotherm area also accordingly increases, and can accelerate the heat dissipation of piston, is conducive to reducing piston unit area Thermic load, reduces high compression ratio and brings phenomenon of detonation.Piston crown is to avoid valve, it is to avoid piston is bumped against with valve, is entering Exhaust side is provided with four valves and avoids hole, and four valves avoid hole all using open by design, and that is, it directly connects piston head The outer in portion.Because inlet valve is relatively large in diameter, thus inlet valve avoid hole diameter also answer relative set more greatly, thus lead to into The thickness that gas side avoids between hole and firepower off coast wall diminishes, and in engine operation process, because wall is thin, operating temperature is high, Operating mode is severe, can produce piston material ablation herein, therefore valve avoids hole open by design, cancels piston material herein, it is to avoid Piston material ablation occurs.

Preferably, the inclination angle of described pit bottom surface is 8 ° -10 °, the depth of pit is 2.5mm-7.0mm.

Preferably, described " u "-shaped boss exceeds cylinder block upper surface 0.5mm-2.0mm.

During piston lower work, due to being subject to very big stress, flexural deformation when piston is worked with piston pin is not mutually assisted Adjust, serious edge load can be caused on the upside of piston boss in the hole, being likely to result in pin-and-hole permanent deformation even makes key seat split, For this reason, piston pin hole outer upper surface is horn mouth technological design, can effectively reduce upper edge load in pin-and-hole, it is to avoid pin-and-hole Crackle in deformation and key seat.

In order to mitigate piston weight to a certain extent, the inner side of described piston boss is curved surface of cutting sth. askew, whole piston pin Seat is up big and down small trapezoidal, and this design can make full use of the effective pressure area of piston boss, reduces piston mass simultaneously, subtracts The impulse force that little inertia causes.

When piston is located at lower dead center, piston boss bottom is the shortest with crankshaft counter balance distance, because piston pin hole bottom is Produced by casting, dimensional tolerance ratio is larger, and crankshaft counter balance is similarly casting and generates, dimensional tolerance is also larger, two castings Tolerance stack, tolerance can be bigger, in engine operation process, there is piston boss and interferes risk with crankshaft counter balance. In order to machine fining-off is adopted to piston boss bottom, machined region is set in piston boss bottom, thus work is effectively ensured Plug pin seat bottom size, it is to avoid piston boss interferes the appearance of failure mode with crankshaft counter balance.

When electromotor just starts, lubricating system does not also have normal work, can't be formed effectively between piston and cylinder holes Lubricating oil film, is easy to scuffing of cylinder bore problem between piston and casing wall, for avoiding the appearance of this situation, in described piston skirt Outer wall is provided with equadag coating.

Beneficial effect：This utility model passes through this structure while being effectively prevented from pinking and occur, and can reach preferably Compression ratio；Improve Tumble and swirl in the case of not changing gas handling system；Change distance between piston combustion bowl and spark plug, More gaseous mixtures cause spark plug nearby it is achieved that the optimal gaseous mixture of spark-plug location；Pit increased valve and piston space Gap, for changing valve stroke headspace, makes VVT range of operation wider；This utility model can effectively improve the thermal efficiency and start Machine economy, it is to avoid the deformation of piston pin hole and pulling.

Brief description

Fig. 1 is the structure chart at the piston structure top that this utility model provides；

Fig. 2 is the vertical direction profile of Fig. 1；

Fig. 3 is another vertical direction profile of Fig. 1；

Fig. 4 is the upward view of the piston structure that this utility model provides.

Specific embodiment

The utility model is described in further detail with reference to the accompanying drawings and examples：

As shown in Figure 1, Figure 2, Figure 3, Figure 4, piston structure includes top land, piston skirt 12, piston boss 9 and Piston pin hole 11, is provided with equadag coating on the outer wall of piston skirt 12.Top land has " u "-shaped boss 5, and this " u "-shaped is convex Platform 5 exceeds cylinder block upper surface 0.5mm-2.0mm." u "-shaped boss 5 area defined forms pit 3, and the bottom surface of pit 3 is Inclined-plane, the inclination angle of pit 3 bottom surface is 8 ° -10 °.The depth of pit 3 is gradually increased from front to back, and numerical value is 2.5mm-7.0mm.Recessed The medial wall in hole 3 is to pass through round-corner transition between scalene cone, and the bottom surface of pit 3 and medial wall.

As shown in Figure 1, Figure 3, the front in " u "-shaped boss 5 opening is provided with two symmetrical inlet valves and avoids hole 6, the rear side of " u "-shaped boss 5 blind end is provided with two symmetrical exhaust valves and avoids hole 6 ', and inlet valve avoids hole 6 and is more than row Valve avoids hole 6 '.In the periphery setting cannelure 13 of " u "-shaped boss 5, this cannelure 13 and inlet valve avoid hole 6 and exhaust valve Avoid hole 6 ' connection, the region that top land is located at cannelure 13 periphery avoids hole 6 ' point by inlet valve avoidance hole 6 and exhaust valve It is divided into four planes, the respectively first plane 1, the second plane 2, the 3rd plane 4 and fourth plane 7, this four planes are same Highly go up, and between this four planes and cannelure 13, pass through arc transition.

As shown in Figure 2, Figure 4 shows, piston pin hole 11 outer upper surface is horn mouth 8.The inner side of piston boss is curved surface of cutting sth. askew, Whole piston boss is up big and down small trapezoidal, and the bottom of piston boss is provided with machined region 10.

Preferred embodiment of the present utility model described in detail above.It should be appreciated that the ordinary skill people of this area Member just can make many modifications and variations according to design of the present utility model without creative work.Therefore, all this technology necks In domain, technical staff passes through logical analyses, reasoning or limited reality on the basis of existing technology according to design of the present utility model Test available technical scheme, all should be in the protection domain being defined in the patent claims.

Claims (7)

1. a kind of piston structure, including top land, piston skirt, piston boss and piston pin hole it is characterised in that：Institute State top land and there is " u "-shaped boss (5), this " u "-shaped boss (5) area defined forms pit (3), the bottom of pit (3) Face is inclined-plane, and the medial wall of pit (3) is to pass through round-corner transition between scalene cone, and the bottom surface of pit (3) and medial wall, in institute The front stating " u "-shaped boss (5) opening is provided with two symmetrical inlet valves avoidance hole (6), and " u "-shaped boss (5) is closed The rear side at end is provided with two symmetrical exhaust valves and avoids hole (6 '), in the periphery setting cannelure of described " u "-shaped boss (5) (13), this cannelure (13) avoids hole (6) with inlet valve and exhaust valve avoids hole (6 ') and connects, and described top land is located at annular The region of groove (13) periphery avoids hole (6) by inlet valve and exhaust valve avoids and cheats (6 ') and be separated into four planes, and respectively first Plane (1), the second plane (2), the 3rd plane (4) and fourth plane (7).

2. piston structure as claimed in claim 1 it is characterised in that：The inclination angle of described pit (3) bottom surface is 8 ° -10 °, The depth of pit (3) is 2.5mm-7.0mm.

3. piston structure as claimed in claim 1 it is characterised in that：Described " u "-shaped boss (5) exceeds cylinder block upper table Face 0.5mm-2.0mm.

4. piston structure as claimed in claim 1 it is characterised in that：Described piston pin hole outer upper surface is horn mouth (8).

5. piston structure as claimed in claim 1 it is characterised in that：The inner side of described piston boss is curved surface of cutting sth. askew, Whole piston boss is up big and down small trapezoidal.

6. the piston structure as described in claim 1 or 5 it is characterised in that：The bottom setting of described piston boss is organic Machining area (10).

7. piston structure as claimed in claim 1 it is characterised in that：The outer wall of described piston skirt is provided with graphite Coating.