CN109340306A

CN109340306A - A Single Shaft Balance Shaft System for Variable Compression Ratio Engine

Info

Publication number: CN109340306A
Application number: CN201811148868.0A
Authority: CN
Inventors: 陈志伟; 龙立; 万建; 邹伟; 刘爽
Original assignee: Dongfeng Motor Corp
Current assignee: Dongfeng Motor Corp
Priority date: 2018-09-29
Filing date: 2018-09-29
Publication date: 2019-02-15

Abstract

The invention discloses a single-shaft balance shaft system of a variable compression ratio engine. It includes a balance shaft located on the side of the crankshaft and installed on the engine block, the balance shaft is an eccentric shaft structure, and the front end of the balance shaft is drivingly connected with a drive gear located on the crankshaft through a driven gear. On the premise of satisfying the functional requirement of balancing the moment of inertia, the invention can well isolate the torsional vibration of the crankshaft of the three-cylinder engine and reduce the gear meshing noise.

Description

A kind of uniaxiality balance axle system of variable compression ratio engine

Technical field

The invention belongs to technical field of automobile engine, and in particular to a kind of uniaxiality balance axis of variable compression ratio engine System.

Background technique

Current automotive industry requires higher and higher, the miniaturization of automobile engine forward direction, big detonation pressure side for energy-saving and environment-friendly To development, current each Automobile Enterprises propose various solutions to cope with engine power performance and Eco-power raising.

Such as published patent, it is used to have such as a variety of known to WO 98/51911, WO 00/31377, WO 03/008783 There are the engine embodiment of variable compression ratio, the internal combustion engine operation that this kind of engine is used to use under changing load and speed When by adjusting effective discharge capacity or compression ratio improve its whole efficiency.Such as published patent WO 03/008783, can be changed The mechanical driving device of compression ratio engine contains at least one cylinder, and bottom is connected to the piston on transmission parts in the cylinder On the one hand middle up and down motion, the transmission parts pass through small size rack gear and cooperate with the guiding device with rolling bearing, another party Face is cooperated by another large scale rack gear with the gear being connected on connecting rod.The connecting rod of the variable compression ratio engine of this type It is connected by gear with burning the cylinder piston and control the cylinder piston, the gear being connected with connecting rod plays leverage, for adjusting in real time Save the compression ratio of such engine, it can be seen that the engine of this type have for Transmission Engine one it is important Feature, i.e., it is many times larger toward complex inertia mass.In addition, crankshaft system torsional oscillation mentions accessory wheel system components since detonation pressure is larger New challenge is gone out, for three cylinder variable compression ratio engines, the size of crankshaft torsional vibrations is compared with conventional engines It greatly improves.However, designing common sense according to engine needs to design balance shaft system to it when reciprocal inertia force square is larger It is balanced, to balance single order two-stage reciprocating inertia force square (can not consider more than second order), need to be arranged two balance shafts, reflect It is compact in current engine structure, arrangement space is limited, uniaxiality balance axle system is also a kind of relatively effective solution party Case.

The characteristics of the first order reciprocating inertia force square can only be generally balanced based on uniaxiality balance axle system, existing uniaxiality balance axis System is most of, and structure is complicated, has a single function, and is driven using chain driving or metal gear, cannot when reciprocal inertia force square is larger When well solving the NVH problem of whole system, and being applied to three cylinder machines, since crankshaft torsional vibrations are big compared with four-cylinder, unavoidably The problem of bringing in terms of torsional oscillation.The balance shaft as disclosed in patent CN107676174 and CN205806326 subtracts although introducing Shake gear, can be effectively reduced the size of crankshaft torsional vibrations, but after this kind of balance shaft of application, engine need to be provided separately lubricating oil pump and The drive scheme of other attachmentes leads to complicated integral structure, and for variable compressive described in patent WO 03/008783 Than engine, since reciprocal inertia force is huge, enough spaces can not be provided to balance reciprocal inertia force square.

Summary of the invention

The object of the invention is in order to solve deficiency existing for above-mentioned background technique, provide a kind of vibration isolating effect it is obvious, Functional diversities, compact-sized, the uniaxiality balance axle system of variable compression ratio engine that is easy for installation and removal.

The technical solution adopted by the present invention is that: a kind of uniaxiality balance axle system of variable compression ratio engine, including be located at Crankshaft side is installed on the balance shaft on engine cylinder body, and the balance shaft is eccentric shaft structure, and the balance shaft front end passes through Driven gear is connect with the sliding tooth wheel drive being located on crankshaft.

Further preferred structure, the balance shaft are fixedly arranged at the front end with transmission gear and forward horizontal stand counterweight, and rear end is fixed There is rear counterweight.

Further preferred structure, the driven gear be decoupling gear, the decoupling gear include gear ring, rubber ring, Wheel hub, the rubber ring is between the gear ring and the wheel hub；The wheel hub is integrated in one with forward horizontal stand counterweight.

Further preferred structure is equipped with aligning structure between the driving gear and decoupling gear.

Further preferred structure, the aligning structure include two the first counterbores, described for driving Gear Root setting The second counterbore of Gear Root setting is decoupled, the second counterbore on the decoupling gear is located at two the first counterbores of driving gear Between.And inner ring web thickness is uneven, it is described that repeated hole and the not uniform thickness web is gone on the one hand to can be used for loss of weight, on the one hand It can be used for adjusting crankshaft imbalance amount.

Further preferred structure, the forward horizontal stand counterweight wheel hub web are unsymmetric structure, and forward horizontal stand counterweight is generally Semicircle shape structure.

Further preferred structure, the rear counterweight wheel hub web is unsymmetric structure, and rear counterweight wheel is whole For semicircle shape structure.

Further preferred structure, the decoupling gear lower section are equipped with oil baffle, and the oil baffle is by being disposed around Bolt fastening on oil sump.

Further preferred structure, the rear counterweight are integrated in one with wet type belt pulley, the rear counterweight Inside has the wheel hub cooperated with the wet type belt pulley gear ring, and the wet type belt pulley gear ring is pressed into the rear counterweight On wheel hub.

Further preferred structure, the rear counterweight are equipped with the boss with third threaded hole.The third screw thread Hole is used to adjust the uneven inertia after balance shaft assembly assembly: if amount of unbalance is overproof, the adjustable screw thread hole depth； If amount of unbalance is insufficient, it can be screwed into the clump weight of certain mass by the threaded hole, increase assembly amount of unbalance.

Further preferred structure, the forward horizontal stand counterweight and rear counterweight wheel hub inner ring be equipped with for the balance Axis positioning surface cooperates the first positioning surface and the second positioning surface.Cooperate when installation with the balance shaft positioning surface, prevents the balance The front and back end counterweight is rotated relative to the balance shaft when axle system operating.

Further preferred structure, the balance shaft middle position open up thrust groove, the thrust groove and are installed on cylinder body On thrust button axial limiting.

Further preferred structure, the thrust groove include two thrust surfaces, open up semi-circular recesses on the thrust surface Structure, the semi-circular recesses structure and thrust button limit connect.

Further preferred structure, the thrust button include bottom plate and with bottom plate support connected vertically, in the support Between setting and balance shaft cooperation groove, open up screw hole on the bottom plate, be fixedly connected by bolt with engine cylinder body.

Further preferred structure, the balance shaft of the balance shaft system, driving gear, driven gear, rear counterweight Deng can adjust unbalance mass, for balancing biggish past complex inertia mass.

The present invention can be well isolated from the torsion of three cylinder machine crankshafts under the premise of meeting the functional requirement of balancing inertia torque Vibration reduces gear engagement noise.

Detailed description of the invention

Fig. 1 is the general illustration of balance shaft system of the invention；

Fig. 2 is the cut away view of balance shaft system in Fig. 1；

Fig. 3 is balance shaft schematic diagram；

Fig. 4 is the left view of balance shaft system in Fig. 1；

Fig. 5 is the exploded view of driving gear and decoupling gear in the present invention；

Fig. 6 is the rear counterweight schematic diagram of balance shaft system of the present invention；

Fig. 7 is the oil baffle schematic diagram of balance shaft system of the present invention.

Wherein, wherein 1- drives gear (11- removes repeated hole, 12- keyway, the first counterbore of 13-), 2- to decouple gear (21- tooth Circle, 22- forward horizontal stand counterweight, 23- rubber ring, the first positioning surface of 25-, 26- through-hole, 27- wheel hub, the second counterbore of 28-, 29- support Muscle), 3- balance shaft (31- front support axle journal, the rear end 32- support axle journal, the first threaded hole of 33-, the second threaded hole of 34-, 35- First radial positioning face, the second radial positioning of 36- face, 37- thrust groove, the first balance weight of 38-, the second balance weight of 39-), 4- stops (51- wet type belt pulley, 52- through-hole, 53- second are positioned for counterweight after push-plate (41- pedestal, 42- support, 43- groove), 5- Face, 54- third threaded hole, 55- boss), 6- bearing, 8- oil baffle (81- oil baffle threaded hole).

Specific embodiment

The following further describes the present invention in detail with reference to the accompanying drawings and specific embodiments, convenient for this hair is well understood It is bright, but they limiting the invention.

As shown in Figure 1, the present invention provides a kind of variable compression ratio engine balance shaft system, including driving gear 1, with The driven gear ring 21 of gear engagement is driven, driven gear ring becomes one with forward horizontal stand counterweight 22, forms decoupling gear 2.Decoupling Gear 2 is connect by bolt with 3 front end of balance shaft (left side in Fig. 1).3 front and back end of balance shaft is equipped with bearing 6.In addition, described Balance shaft system further includes rear counterweight 5, which becomes one with wet type belt pulley 51, blending bolt fastening In balance shaft rear end (right side in Fig. 1).The wet type belt pulley 51 drives engine oil pump by belt.The decoupling gear 2 Lower section there is oil baffle 8, oil baffle 8 is mounted on engine sump tank by bolt.

As shown in Figures 2 and 3, balance shaft 3 is respectively provided with front support axle journal 31 and rear end support axle journal 32, for installing Front and back end bearing, front and back end bearing is installed on engine cylinder body, it is possible thereby to support balance shaft system.Balance shaft front/rear end It is respectively provided with the first threaded hole 33 and the second threaded hole 34, for fixing forward horizontal stand counterweight 22 and rear counterweight 5, when assembly is first Balance shaft 3 is mounted on engine cylinder body, is then bolted, forward horizontal stand counterweight 22, rear counterweight 5 are fastened on In balance shaft.3 front and back end of balance shaft is machined with the first radial positioning face 35 and the second radial positioning face 36, and balance is matched in a pre-installation For being aligned when weighing 22, rear counterweight 5.3 middle position of balance shaft is machined with thrust groove 37, matched balance shaft Thrust button 4 is mounted on lower cylinder body or oil sump, balance shaft play on axially and radially direction when preventing from running at high speed, thus Improve the NVH effect of balance shaft system.

3 part of balance shaft is processed, and 180 ° of symmetrical first balance weights 38 and the second balance weight 39 are formed, Under the premise of guaranteeing axis performance requirement, overall weight as smaller as possible and amount of unbalance.The symmetrical balance weight needs Guarantee consistent with the direction of anterior-posterior balance counterweight 22 and 5 after installing.

Front and back end bearing 6 preferably uses rolling bearing, because the balance shaft system overall structure is compact, integral arrangement Space is more rich, and without the independent processing and lubrication oil duct in balance shaft and cylinder body, simplifies the manufacture of balance shaft.As one kind Embodiment, front and back bearings are all made of needle bearing.

As depicted in figs. 1 and 2, the thrust button 4 includes pedestal 41 and support 42, and pedestal 41 passes through under bolt and engine Cylinder body or oil sump connection.The support 42 has certain interval in axially and radially direction with balance shaft thrust groove 37.Balance When axis operates, balance shaft thrust button can provide axial two-way and radial direction thrust function.Position is located at oil sump at this Near, without individually lubrication.

Fig. 4 indicates the driving gear 1 and decoupling gear 2 of balance shaft system, and driving 1 Central web section of gear has several Remove repeated hole 11, and not beat duplicate removal bore region thickness with web inconsistent for duplicate removal bore region thickness.Driving inner ring gear is machined with key Slot 12, for being connect with crankshaft.By removing repeated hole 11 and not the gear web of uniform thickness, crankshaft injustice can be adjusted most possibly It measures.

Drive gear 1 and decoupling gear 2 that there is phase relation, phase relation causes confusion when to prevent installation, such as Fig. 4 institute Showing in driving gear 1 and decouple the initial engagement position of gear 2, driving 1 root position of gear processes two the first counterbores 13, It decouples 2 root position of gear and processes second counterbore 28.When installation, first driving gear 1 is mounted on crankshaft, and will balance Axis 3 is mounted on cylinder body, then decoupling gear 2 is mounted on to the front end of balance shaft 3, guarantees the second counterbore 28 on decoupling gear 2 Between 2 the first counterbores 13 of driving gear 1, that is, it can guarantee the phase relation of entire balance shaft system and crankshaft.Phase Relationship is most important for balance shaft system or even global vibration of engine, and engine designs initial stage, past according to engine Multiple inertia force size, each sub- part of balance shaft is adjusted and optimizes to its counterweight size and location, so as to entirely balance shafting The amount of unbalance of system meets engine design requirement.Once phase relation solidifies, the counterweight and amount of unbalance of each sub- part are just solid Change, driving gear can effectively decompose the amount of unbalance of balance shaft system with the phase relation for decoupling gear setting in the present invention Onto each sub- part, the control and cost be conducive in manufacture and assembling process is reduced.

As shown in figure 5, decoupling gear 2 include wheel hub 27, rubber ring 23 and driven gear ring 21, wheel hub 27 preferably with forward horizontal stand Counterweight 22 is integrated in one, and therefore saves on integral installation space, supporting rib 29 is set in 27 web of wheel hub, rubber ring 23 passes through vulcanization Technique is connected on driven gear ring 21 and the wheel hub 27 being integrated in one with forward horizontal stand counterweight, and with 3 front end of balance shaft (in Fig. 1 Left side) it is fastened by bolts.Preferably there are several spoke architectures among the inner ring and outer ring of the wheel hub, guaranteeing that transmitting is strong Under the premise of degree requires, the weight of gear is reduced to the greatest extent.Inner ring processes the first positioning surface 25, when installation with 3 front end of balance shaft The first radial positioning face 35 cooperation, prevent it is wrongly installed or installation after there is relative motion, form a kind of effective torque drive Structure.Wheel hub inner ring is formed with a through-hole 26, and bolt is by the through-hole when installation, and connect with balance shaft 3.

If Fig. 6 is indicated, rear counterweight 5 is combined as a whole with wet type belt pulley 51 by press-fit approach, rear counterweight 5 Positioned at the outside (right side of balance shaft in Fig. 1) of wet type belt pulley 51,51 inner ring of wet type belt pulley is machined with the second positioning surface 53 With through-hole 52, during installation, the second radial positioning face 36 of the second positioning surface 53 and balance shaft rear end cooperates, before guaranteeing after installation Counterweight is symmetrical at 180 ° afterwards.Counterweight 5 and 51 transition position of wet type belt pulley have one to be machined with third threaded hole 54 afterwards Boss 55, balance shaft assembly assembly after amount of unbalance detection when, can be by changing the boss if amount of unbalance is overproof 55 54 depth of third threaded hole is adjusted, if amount of unbalance is insufficient, can by be screwed into certain mass band mass block, increase Amount of unbalance.

As shown in fig. 7,8 surrounding of oil baffle below decoupling gear is distributed four threaded holes 81, pass through 4 bolts when installation Oil baffle is fixed on oil sump, the oil baffle plate structure is compact, when structure can effectively prevent balance shaft system to run at high speed Decouple the agitation of gear mesh machine oil.

The content being not described in detail in this specification belongs to the prior art well known to professional and technical personnel in the field.

Claims

1. A single-shaft balance shaft system of a variable compression ratio engine, characterized in that: it comprises a balance shaft (3) positioned on the side of the crankshaft and installed on the engine cylinder, and the balance shaft (3) is an eccentric shaft structure, The front end of the balance shaft (3) is drivingly connected with a drive gear (1) on the crankshaft through a driven gear.

2 . The single-shaft balance shaft system of a variable compression ratio engine according to claim 1 , wherein a transmission gear and a front balance weight ( 22 ) are fixed at the front end of the balance shaft ( 3 ). A rear balance weight (5) is fixed at the end.

3. The single-shaft balance shaft system of a variable compression ratio engine according to claim 2, wherein the driven gear is a decoupling gear (2), and the decoupling gear (2) comprises a tooth A ring (21), a rubber ring (23), a wheel hub (27), the rubber ring (23) is located between the ring gear (21) and the wheel hub (27); the wheel hub (27) is balanced with the front The counterweight (22) is integrated into one.

4 . The single-shaft balance shaft system of a variable compression ratio engine according to claim 3 , wherein an alignment structure is provided between the drive gear ( 1 ) and the decoupling gear ( 2 ). 5 .

5 . The single-shaft balance shaft system of a variable compression ratio engine according to claim 4 , wherein the alignment structure comprises two first counterbores ( 13 ) provided at the root of the drive gear ( 1 ). 6 . ), the second counterbore (28) provided at the tooth root of the decoupling gear (2), and the second counterbore (28) on the decoupling gear (2) is located in the two first countersunk holes (28) of the drive gear (1). between the counterbore (13).

6 . The single-shaft balance shaft system of a variable compression ratio engine according to claim 2 , wherein the front balance weight ( 22 ) has a semicircular structure. 7 .

7. The single-shaft balance shaft system of a variable compression ratio engine according to claim 3, characterized in that: an oil baffle (8) is arranged below the decoupling gear (2), and the oil baffle (8) Fastened to the oil pan by bolts arranged around it.

8. A uniaxial balance shaft system for a variable compression ratio engine according to claim 2, characterized in that: the rear balance weight (5) and the wet pulley (51) are integrated into one body, and the rear balance The inner side of the counterweight (5) is provided with a hub matched with the gear ring of the wet pulley (51), and the gear ring of the wet pulley (51) is press-fitted onto the rear balance weight hub.

9 . The uniaxial balance shaft system of a variable compression ratio engine according to claim 8 , wherein the rear balance weight ( 5 ) is provided with a boss with a third threaded hole ( 54 ). 10 . (55).

10. A single-shaft balance shaft system for a variable compression ratio engine according to claim 2, characterized in that: the front balance weight (22) and the rear balance weight (5) are provided on the inner ring of the wheel hub for A first positioning surface (25) and a second positioning surface (53) are matched with the positioning surface of the balance shaft (3).

11. The single-shaft balance shaft system of a variable compression ratio engine according to claim 1, wherein a thrust groove (37) is provided in the middle position of the balance shaft (3), and the thrust groove ( 37) and the thrust plate (4) installed on the cylinder body to limit axially.

12 . The single-shaft balance shaft system of a variable compression ratio engine according to claim 11 , wherein the thrust groove ( 37 ) comprises two thrust surfaces, and the thrust surfaces are provided with a half-shaft opening. A circular groove structure, the semicircular groove structure is connected with the thrust plate (4) in a limited position.

13 . The single-shaft balance shaft system of a variable compression ratio engine according to claim 11 , wherein the thrust plate ( 4 ) comprises a bottom plate ( 41 ) and a support vertically connected to the bottom plate ( 41 ). 14 . A seat (42) is provided in the middle of the support (42) with a groove (43) matched with the balance shaft, and the bottom plate (41) is provided with screw holes, which are fixedly connected to the engine cylinder block through bolts.