CN202090977U - Reset type rocker braking device - Google Patents
Reset type rocker braking device Download PDFInfo
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- CN202090977U CN202090977U CN 201120159441 CN201120159441U CN202090977U CN 202090977 U CN202090977 U CN 202090977U CN 201120159441 CN201120159441 CN 201120159441 CN 201120159441 U CN201120159441 U CN 201120159441U CN 202090977 U CN202090977 U CN 202090977U
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- emptying
- braking
- valve
- piston hole
- piston
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L13/00—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations
- F01L13/06—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for braking
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/12—Transmitting gear between valve drive and valve
- F01L1/18—Rocking arms or levers
- F01L1/181—Centre pivot rocking arms
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/26—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of two or more valves operated simultaneously by same transmitting-gear; peculiar to machines or engines with more than two lift-valves per cylinder
- F01L1/267—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of two or more valves operated simultaneously by same transmitting-gear; peculiar to machines or engines with more than two lift-valves per cylinder with means for varying the timing or the lift of the valves
Abstract
Disclosed is a reset type rocker braking device. A braking piston hole and an oil discharge piston hole which are connected with a braking oil supply channel are arranged inside a rocker, and an oil discharge channel is arranged between the braking piston hole and the oil discharge piston hole. When the rocker is driven by a braking boss of a cam, an exhaust valve is opened to realize braking by a braking piston inside the braking piston hole of the rocker. When the rocker is driven by an exhaust boss of the cam, the rocker moves to drive an oil discharge piston in the oil discharge piston hole to open the oil discharge channel to discharge oil, the braking piston in the braking piston hole moves from a stretching position to a retracting position, and the lifting stroke of the exhaust valve is reduced by means of resetting to form a valve lift curve of movement of a conventional exhaust valve without an engine for braking. An engine braking mechanism and a reset oil discharge mechanism are integrated in the rocker, and the reset type rocker braking device is simple in design and compact in structure, reduces the weight and the height of an engine, increases braking power of the engine, and improves reliability and durability of the engine in operation.
Description
Technical field:
The utility model relates to mechanical field, relates in particular to the valve actuation field of vehicle motor, particularly a kind of replacement formula rocking arm braking device.
Background technique:
In engine braking methods, open exhaust valve in the later stage of engine piston compression stroke, close exhaust valve in the early stage of expansion stroke (generally before the normal unlatching of exhaust valve).A precedent of engine brake is disclosed at U.S. Patent number 3220392 in nineteen sixty-five by comings (Cummins).Braking system is delivered to the exhaust valve that will open through oil hydraulic circuit with the machinery input.Be usually included in reciprocating brake piston in the brake piston hole in the oil hydraulic circuit, this to-and-fro motion comes from the machinery input of motor, such as the motion of the motion of motor injection cam or adjacent exhaust cam.The hydraulic fluid that moves through of brake piston is delivered to sub-piston on the oil hydraulic circuit, makes its to-and-fro motion in slave piston bore, and sub-piston acts on the exhaust valve directly or indirectly, produces the valve motion of engine braking running.
The engine braking apparatus of comings is the annex of overhead on motor.For this type of engine brake is installed, between cylinder and valve gap, to add packing ring, therefore, increase height, weight and the cost of motor extraly.Obviously, solution of the above problems is that the parts with braking device are integrated in the existing parts of motor, as is integrated in the rocking arm of motor, forms the integrated form break.
U.S. mark (Mack) truck company discloses a kind of integrated form rocking arm break in 1974 for No. 3786792 in patent.The brake piston of this braking system is being hydraulically locked in extended position near in the rocking arm cylinder of push rod one end, gives an exhaust valve (early stage every cylinder single valve motor) with the transmission of movement of cam, produces the engine braking running.Cam is integrated in one with conventional boss and braking boss.The brake control valve mechanism of this braking system (combination of funnel-shaped plunger valve+non-return valve) was widely adopted afterwards.
The U.S. all can win (JVS) company and disclose another kind of integrated form rocking arm break in 1974 for No. 3809033 in patent.The brake piston of this braking system is placed near in the rocking arm cylinder of valve bridge one end, can move between non-braking position and application position.In application position, brake piston is hydraulically locked in extended position, gives the valve bridge with the transmission of movement of cam, opens two exhaust valves (every cylinder bivalve motor), produces the engine braking running.This braking system adopts two kinds of oil ducts that separate, and a kind of oil duct only is the break fuel feeding, and another kind is conventional engine lubrication oil duct.
Sweden's Volvo (Volvo) company discloses a kind of integrated form rocking arm braking system that is used for the overhead-cam four-valve engine in 1996 for No. 5564385 at U. S. Patent.It is very close on structure and principle at No. 3809033 disclosed integrated form rocking arm break of patent in 1974 that this braking system and the U.S. all can win (JVS) company.The hydraulic braking piston is placed near in the rocking arm cylinder of valve bridge one end, can move between non-braking position and application position, in the inner gap that forms of motor air valve system.Pressure-bearing oil is supplied with brake piston by pressure controlled valve and is filled up valve clearance in the rocking arm, forms the hydraulic pressure link.This engine braking system has adopted the combined mechanism of " funnel-shaped plunger valve+non-return valve ", has increased the overload pressure relief means thereon and has adopted single oil duct that the oil feeding mechanism of two oil pressure is provided.The low oil pressure of two oil pressure (being lower than the lubrication pressure of motor) is used for the lubricated of motor, and the high oil pressure of two oil pressure (equaling the lubrication pressure of motor) is used for the braking of motor.During braking, brake piston promotes the valve bridge, opens two air exhaust valve brakes simultaneously.
U.S. mark (Mack) truck company discloses another integrated form rocking arm break in calendar year 2001 for No. 6234143 in patent.This braking system was compared in No. 3786792 disclosed patented technology of patent with its 1974, had than cataclysm.At first, the integrated form cam that conventional boss and braking boss form has increased exhaust gas recirculatioon (EGR) boss, helps improving braking force.Secondly, the motor of every cylinder single valve has become every cylinder bivalve, has therefore increased valve bridge (air valve bridge or transverse arm).Also have, brake piston has moved on in the rocking arm piston hole of valve bridge one end from push rod one end, is positioned at exhaust valve (valve) top near pitman arm shaft.During braking, brake piston is opened an exhaust valve by braking jacking block or acting directly on the valve bridge.But, owing to open the single valve braking, the valve bridge is in heeling condition, can produce asymmtric load on valve bridge and rocking arm.In addition, the lifting curve of braking valve (interior valve) is greater than the lifting curve (amount of opening is bigger, closes more late) of non-braking valve (outer valve) or conventional valve.
Comings (Cummins) motor company discloses a kind of integrated form rocking arm braking system that valve rises replacement mechanism that has in calendar year 2001 for No. 6253730 at U. S. Patent, the time open the lifting curve problems such as (open amount bigger, close more late) of the lifting curve of non-symmetrical load that single valve (interior valve) caused and braking valve (interior valve) with solving braking greater than non-braking valve (outer valve) or conventional valve.Valve rises replacement mechanism and the brake piston in the rocking arm is reached at brake valve resets before the highest brake valve rises or withdraw, make brake valve before main valve action beginning, get back to valve seat, the valve bridge is got back to horizontal position, and rocking arm can be opened brake valve and non-brake valve evenly, eliminates any asymmtric load.
But, make engine braking system replacement or reset before the braking valve reaches the highest brake valve and rises, problem is a lot.At first, the opening time of braking valve and highly very short during engine braking, the time that can be used for resetting is just more limited.Secondly, reset when occurring near engine braking load maximum (compression stroke upper dead center), the valve that resets that makes valve rise replacement mechanism bears high oil pressure or big load.The timing (Timing) that engine braking is reset is most important.Take place too morning if reset, brake valve rises loss too many (the valve lifting is low to reach valve closing too early), reduces braking ability.Take place too late if reset, the braking valve can't be closed before main valve action beginning, cause non-symmetrical load.Test shows, this integrated form rocking arm break can't proper functioning when high engine speed because the replacement time too short, reset highly too for a short time, and load on the valve that resets or pressure are very high.
Summary of the invention:
The purpose of this utility model is to provide a kind of replacement formula rocking arm braking device, the technical problem that described this replacement formula rocking arm braking device will solve the reliability that exists in the available engine braking technology and durability is bad, brake unbalance loading or reset shakiness, installation and inconvenient debugging and increase motor height and weight.
This replacement formula rocking arm braking method of the present utility model comprises the braking control mechanism, braking drive organ, exhaust valve actuator and at least one exhaust valve, described exhaust valve actuator comprises cam and rocking arm, described cam contains exhaust boss and at least one braking boss, described exhaust boss is higher than the braking boss, wherein, described braking control mechanism comprises a control valve that is connected with the hydraulic pressure generation device, described braking drive organ comprises oil feeding mechanism, emptying mechanism and brake piston, described brake piston has an extended position and a retracted position in the brake piston hole of rocking arm, the lower end of described brake piston links to each other with at least one described exhaust valve, described oil feeding mechanism comprises braking oil supply gallery and unidirectional delivery valve, the control valve of described braking control mechanism is connected with the inlet of described braking oil supply gallery, the outlet of braking oil supply gallery is connected with the brake piston hole, described unidirectional delivery valve is arranged between braking oil supply gallery and the brake piston hole, perhaps in the braking oil supply gallery, the fuel feeding direction of unidirectional delivery valve is to enter the brake piston hole from the braking oil supply gallery, described emptying mechanism comprises an oil drain valve and emptying passage, and described oil drain valve is connected with the brake piston hole by the emptying passage.
Further, described braking drive organ also comprises preloading spring, the gap that described preloading spring keeps retracted position and the extended position by brake piston to generate in the exhaust valve chain of motor.
Further, described braking drive organ also comprises position-limit mechanism, and described position-limit mechanism limits the stroke of described brake piston in the brake piston hole.
Further, described oil drain valve comprises the emptying piston in the emptying piston hole that is arranged on the rocking arm, the relative emptying piston hole of described emptying piston has an application position and a replacement position, the bottom of described emptying piston hole is communicated with described braking oil supply gallery, the middle part of described emptying piston hole links to each other with an end of an emptying passage, the other end of described emptying passage is communicated with described brake piston hole, in described application position, the emptying piston is closed described emptying passage, in described replacement position, the emptying piston is opened described emptying passage.
Further, described oil drain valve comprises the emptying piston in the emptying piston hole that is arranged in the valve clearance adjusting screw, the relative emptying piston hole of described emptying piston has an application position and an emptying position, also be provided with an emptying passage in the described valve clearance adjusting screw, one end of described emptying passage links to each other with the bottom of emptying piston hole, and the other end of described emptying passage is communicated with described brake piston hole; In described application position, the emptying piston is positioned at the bottom of emptying piston hole, described emptying pathway closure, and in described replacement position, the emptying piston is positioned at the top of emptying piston hole, and described emptying passage is opened.
Further, described braking drive organ also comprises a replacement supporting structure, described replacement supporting structure is fixed on the motor of upside of rocking arm one end at emptying piston hole place, the motion of described replacement supporting structure restriction emptying piston in the emptying piston hole.
Working procedure of the present utility model is: at first, open the braking control mechanism, by braking oil supply gallery simultaneously to emptying piston hole and brake piston hole fuel feeding, brake piston is placed extended position, simultaneously the emptying piston is placed the position of closing the emptying passage, then, utilize the braking boss drive rocking arm in the cam to open at least one exhaust valve of brake piston below with the brake piston that is in extended position, afterwards, utilize the ascent stage that is higher than the exhaust boss of braking boss in the cam to continue to drive rocking arm, utilize simultaneously the motion of rocking arm change the emptying piston in the emptying piston hole the position and open the emptying passage, utilize the emptying passage to brake piston hole emptying, make brake piston move on to retracted position from extended position, skip of the driving of the part at exhaust boss top to exhaust valve, at last, utilize the descending branch of exhaust boss in the cam to make the rocking arm revolution, utilize the return movement of rocking arm change the emptying piston in the emptying piston hole the position and close the emptying passage, continue fuel feeding by braking oil supply gallery and unidirectional delivery valve to the brake piston hole simultaneously, brake piston is placed extended position again, begin a new engine braking cycle period.
Further, a replacement supporting structure is set, described replacement supporting structure is fixed on the motor, utilize the motion of described replacement supporting structure restriction emptying piston in the emptying piston hole at the upside of rocking arm one end at emptying piston hole place.
Further, utilize preloading spring to keep by the retracted position of brake piston and extended position, not the following and impact of elimination exhaust valve chain inside in the inner gap that generates of exhaust valve chain.
Further, the process of described unlatching exhaust valve may further comprise the steps:
1. open the engine braking control mechanism,
2. by the emptying piston hole fuel feeding of described braking oil supply gallery in rocking arm,
3. the emptying piston is built in the position of closing the emptying passage at the emptying piston hole,
4. the brake piston hole fuel feeding in rocking arm by described braking oil supply gallery and unidirectional delivery valve,
5. brake piston is built in extended position in the brake piston hole, forms hydraulic pressure link and locking,
6. the braking boss drive rocking arm of cam and the brake piston that stretches out are opened at least one exhaust valve, produce the brake valve liter,
7. cam arrives at the ascent stage that is higher than the exhaust boss of braking boss, continues to drive rocking arm and the brake piston and the exhaust valve that stretch out,
8. the emptying piston in the emptying piston hole is moved on to the position of opening the emptying passage from the position of closing the emptying passage, by brake piston hole emptying,
9. brake piston moves on to retracted position from extended position in the brake piston hole, and the lift of exhaust valve during the exhaust stroke of motor is reset and reduces,
10. cam rolls back the interior basic circle of cam under the top lift of exhaust boss, rocking arm with the brake piston of withdrawal and exhaust valve toward swivel motion,
11. the emptying piston that drives in the emptying piston hole is got back to application position from the replacement position, closes the emptying passage again,
12. get back to step 4, begin new turbine braking cycle period.
Further, the process of unlatching exhaust valve is further comprising the steps of:
1. the braking control mechanism that kills engine,
2. stop emptying piston hole and brake piston hole fuel feeding in rocking arm,
3. the emptying piston is opened emptying passage emptying,
4. brake piston links with hydraulic pressure between the rocking arm and removes and form a gap,
5. cam up moves from interior basic circle,
6. exhaust valve keeps transfixion,
7. cam arrives at and is higher than the ascent stage of braking boss, drives rocking arm, opens exhaust valve, produces conventional outlet valve liter.
Further, include a compression in the braking boss and discharge boss.
Further, include an exhaust gas recirculatioon boss in the braking boss.
Working principle of the present utility model is: when the needs engine braking, the braking control mechanism is opened, and control valve is to the braking drive organ fuel feeding.Low-pressure oil (engine lubricating oil) enters in the brake piston hole from oil supply gallery and unidirectional delivery valve, and brake piston is in extended position in the brake piston hole of rocking arm.The emptying piston is in application position in the emptying piston hole of rocking arm, close the emptying passage between brake piston hole and the emptying piston hole.The braking boss of cam toward rising, drives the brake piston that is in extended position and hydraulic pressure locking in rocking arm and the brake piston hole from interior basic circle, opens air exhaust valve brake.
The exhaust boss of cam rises when surpassing the height of braking boss; the emptying piston in the emptying piston hole of rocking arm moves on to the replacement position from application position; open the emptying passage between brake piston hole and the emptying piston hole; brake piston hole emptying; brake piston moves on to retracted position from extended position, exhaust valve lift are reset the valve that is varied down to the conventional exhaust valve motion of not being with engine braking and rise curve.
The utility model is compared with prior art, and its effect is actively with tangible.The utility model is integrated in engine braking mechanism and replacement emptying mechanism in the existing rocking arm of motor, simplicity of design, compact structure, reduced motor weight and the height, increase the braking force of motor, improved the reliability and the durability of engine operation.
Description of drawings:
Fig. 1 is first embodiment of replacement formula rocking arm braking device of the present utility model is in the off-position at engine braking apparatus a schematic representation.
Fig. 2 is first embodiment of replacement formula rocking arm braking device of the present utility model is in " opening " position at engine braking apparatus a schematic representation.
Fig. 3 is the schematic representation of the emptying piston of replacement formula rocking arm braking device of the present utility model.
Fig. 4 is the schematic representation that the braking control mechanism of replacement formula rocking arm braking device of the present utility model is in " opening " position.
Fig. 5 is the schematic representation that the braking control mechanism of replacement formula rocking arm braking device of the present utility model is in the off-position.
Fig. 6 is the schematic representation of a kind of cam profile of replacement formula rocking arm braking device of the present utility model.
Fig. 7 is a kind of exhaust valve lift curve of replacement formula rocking arm braking device of the present utility model and the schematic representation of intake valve lifting curve.
Fig. 8 is the schematic representation of second embodiment basic circle position in cam is in of replacement formula rocking arm braking device of the present utility model.
Fig. 9 is the 3rd embodiment of replacement formula rocking arm braking device of the present utility model is in the off-position at engine braking apparatus a schematic representation.
Figure 10 is the 4th embodiment of replacement formula rocking arm braking device of the present utility model is in the off-position at engine braking apparatus a schematic representation.
Embodiment:
Embodiment 1:
Fig. 1 and Fig. 2 have represented that first embodiment of replacement formula rocking arm braking device of the present utility model is in the position of " pass " and " opening " at engine braking apparatus.Comprise four chief components among Fig. 1 and Fig. 2: exhaust valve actuator 200, Exhaust valve mechanism 300, engine braking driving mechanism 100 and replacement supporting structure 150.
The conventional exhaust and braking dual functions of motor that cam 230 is integrated.An increasing boss 220 that is mainly used in the conventional exhaust running of motor is arranged on the interior basic circle 225 of cam 230, and it is bigger than the exhaust boss of conventional (not with engine braking) to strengthen boss 220, is integrated form exhaust boss again.The reason that strengthens is that cam 230 also has small boss 232 and the small boss 233 that is used for engine braking.When motor routine (igniting) operated, in order to skip braking small boss 232 and small boss 233, the bottom of strengthening boss 220 must increase and small boss 232 and small boss 233 about contour transition portions, and its top is equivalent to conventional exhaust boss.Exhaust gas recirculatioon when small boss 232 is used to brake, the compression when 233 of small boss are used to brake discharges.The cam lifting curve that the increasing boss 220 of cam 230, small boss 232 and small boss 233 are generated is described in detail in Fig. 6.
Braking drive organ 100 comprises oil feeding mechanism, emptying mechanism and brake piston 160.
Oil feeding mechanism comprises braking oil supply gallery and unidirectional delivery valve 172.For simplicity's sake, the oil leab of motor in pitman arm shaft 205 and rocking arm 210 do not show at this.The braking oil supply gallery is included in otch 213 and the oil duct 214 in axial bore 211 in the pitman arm shaft 205 and radial hole 212, the rocking arm 210.The outlet of oil duct 214 is connected with brake piston hole 190.Unidirectional delivery valve 172 is arranged between oil duct 214 and the brake piston hole 190, and its fuel feeding direction is to enter brake piston hole 190 from oil duct 214.The valve ball of unidirectional delivery valve 172 is biased on the valve seat by spring 156.In the middle of actual the use, unidirectional delivery valve 172 can increase spring seat or use different mounting types.
Emptying mechanism comprises an oil drain valve and emptying passage 219.Oil drain valve comprises the emptying piston 170 in the emptying piston hole 183 that is arranged on the exhaust rocker arm 210.Emptying piston 170 relative emptying piston holes 183 have three different positions: non-braking position, application position and emptying position.The bottom of emptying piston hole 183 is communicated with oil duct 214.The middle part of emptying piston hole 183 links to each other with an end of emptying passage 219, and the other end of emptying passage 219 is communicated with brake piston hole 190.At non-braking position as shown in Figure 1, emptying piston 170 is positioned at the bottom of emptying piston hole 183, and emptying passage 219 is opened; In application position as shown in Figure 2, emptying piston 170 is positioned at the middle part of emptying piston hole 183, the emptying pathway closure; In the replacement position, emptying piston 170 is positioned at the top of emptying piston hole 183, and the emptying passage is opened once more.Therefore, the switching of oil drain valve is by the interior determining positions of emptying piston 170 at emptying piston hole 183.
When the needs engine braking, as shown in Figure 4, open braking control mechanism 50.The inlet of the axial oil duct 211 in control valve 51 and the pitman arm shaft 205 of braking control mechanism is connected, and passes through other and brake oil supply gallery, to braking drive organ 100 fuel feeding.Low-pressure oil is shifted the emptying pistons 170 in the emptying piston hole 183 onto application position (Fig. 2) from non-braking position (Fig. 1), rests on the bottom surface of adjusting screw 1102 of replacement supporting structure 150.Close emptying passage 219.Meanwhile, machine oil is by unidirectional delivery valve 172, fuel feeding in brake piston hole 190.Brake piston 160 is in extended position in the brake piston hole 190 of rocking arm 210, and forms a gap 234 between the bottom surface, hole in brake piston hole 190 (just rocking arm 210).
When the small boss that is used to brake 233 on the cam 230 (compression discharge boss) from interior basic circle 225 when rising; rocking arm 210 clockwise rotates; drive and be in extended position in the brake piston hole 190 of rocking arm 210 and form the brake piston 160 of hydraulic pressure locking downward, opens the exhaust valve 301 below it.Although a gap 234 is arranged between brake piston 160 and the rocking arm 210, but because the unidirectional delivery valve 172 and the emptying passage 219 of having closed, machine oil has formed between brake piston 160 and rocking arm 210 that hydraulic pressure links and locking, can be with the transmission of movement supply and exhaust door 301 of small boss 233 and small boss 232.
In the process that cam 230 driving rocking arms 210 clockwise rotate, rocking arm 210 leaves replacement supporting structure 150 from contact position shown in Figure 2, and emptying piston 170 also up moves from application position in emptying piston hole 183.But the structure of oil drain valve makes the hypomotility of small boss 233 to open emptying passage 219.The end face 147 (Fig. 3) of emptying piston 170 still contacts with adjusting screw 1102, and the outer wall of emptying piston 170 is still blocked emptying passage 219.
If the braking boss of cam 230 also comprises the small boss 232 that is used for exhaust gas recirculatioon, small boss 232 drives the process of exhaust valves 301 so, and the process that drives exhaust valves 301 with above-mentioned small boss 233 is identical, no longer repeats at this.
Change the ascent stage that is higher than small boss 233 of exhaust boss 220 over to when cam 230 after; it is enough far away that rocking arm 210 leaves replacement supporting structure 150; emptying piston 170 moves on to the replacement position in emptying piston hole 183; annular groove 180 (Fig. 3) on the emptying piston 170 is opened emptying passage 219 among Fig. 2, brake piston hole 190 emptyings.Move on the brake piston 160, eliminate gap 234, lost by the exhaust valve motion that small boss 233 produces, the valve liter of exhaust valve 301 is reset the valve that is varied down to the conventional exhaust valve motion of not being with engine braking and rises curve.
When cam 230 changes the top of exhaust boss 220 over to, the end face 147 (Fig. 3) of emptying piston 170 will break away from adjusting screw 1102, the step surface 148 (Fig. 3) of emptying piston 170 contacts with stop bit screw 179 (Fig. 2) on the rocking arm, and emptying passage 219 is opened fully by the annular groove on the emptying piston 170 180.
When cam 230 turns over the extreme higher position of exhaust boss 220 and roll back down the interior basic circle 225 of cam, brake piston 160 and exhaust valves 301 brake piston 160 below under the effect of valve spring 310 the back motion of rocking arm 210 in being retracted in brake piston hole 190.Emptying piston 170 in the emptying piston hole 183 is got back to application position from the replacement position downwards, closes emptying passage 219 again.Machine oil passes through unidirectional delivery valve 172 once more, fuel feeding in brake piston hole 190, and brake piston 160 is got back to extended position from retracted position in brake piston hole 190, the braking cycle period of a beginning new round.
When not needing engine braking, as shown in Figure 5, close braking control mechanism 50, control valve 51 stops to braking drive organ 100 fuel feeding.Emptying piston 170 does not have the effect of engine oil pressure, is built in as shown in Figure 1 non-braking position at emptying piston hole 183, and emptying passage 219 is opened, and no longer forms hydraulic pressure between brake piston 160 and the rocking arm 210 and links.
When the small boss 233 of cam 230 (compression discharges boss) from interior basic circle 225 when rising, rocking arm 210 clockwise rotates.But because relative movement is only done between rocking arm 210 and the brake piston 160 in the gap 234 between brake piston 160 and the rocking arm 210, exhaust valve 310 keeps transfixion.That is to say that in non-braking state shown in Figure 1, the motion of small boss 233 and small boss 232 can be delivered to exhaust valve 301 because gap 234 loses, the braking running of motor is disengaged.
When cam 230 enter exhaust boss 220 be higher than the ascent stage of small boss 233 time, the gap 234 between brake piston 160 and the rocking arm 210 begins to disappear, rocking arm 210 directly promotes brake piston 160, opens exhaust valve 301.That is to say, to have only the transmission of movement supply and exhaust door 301 at exhaust boss 220 tops, produce conventional exhaust valve motion in non-braking state shown in Figure 1.
As shown in Figure 4 and Figure 5, the braking control mechanism 50 of replacement formula rocking arm braking device of the present utility model is in the position of " opening " and " pass ".Control valve 51 among the figure is a two-position three way type solenoid valve.When braking control mechanism 50 is opened (Fig. 4), the valve body of control valve 51 is opened oil-feed port 111 downwards, closes unloading port 222 simultaneously, and the low-pressure oil of motor (lubricant oil) flows to braking drive organ 100 (Fig. 1 and Fig. 2) from the brake fluid passage.When braking control mechanism 50 cuts out (Fig. 5), the valve body of control valve valve 51 is upwards closed oil-feed port 111, open unloading port 222 simultaneously, the low-pressure oil of motor (lubricant oil) stops to flow to braking drive organ 100 (Fig. 1 and Fig. 2), and braking drive organ 100 is from brake fluid passage and unloading port's 222 emptyings.Owing to be provided with emptying passage 219 (Fig. 1 and Fig. 2) between brake piston hole 190 in the rocking arm 210 and the emptying piston hole 183, each cycle emptying once, might use two two way solenoid valves to replace three-way magnetic valve, that is to say, not need unloading port 222.
Fig. 6 has shown a kind of cam profile in the replacement formula rocking arm braking device of the present utility model, is the interior basic circle of cam comprising braking boss and integrated form exhaust boss 220,225.The braking boss comprises small boss 233 and small boss 232.Integrated form exhaust boss 220 is divided into bottom and top (double dot dash line among Fig. 6 separates them).The bottom of integrated form exhaust boss 220 is a transition portion, and is approaching with high with the braking boss; The top of integrated form exhaust boss 220 is approaching identical with the conventional boss of motor.Like this, when non-braking (conventional igniting) running, the bottom of integrated form exhaust boss 220 is all skipped because of the gap 234 (Fig. 1) of exhaust valve chain inside together with the motion of braking boss (small boss 233 and small boss 232) or is lost, and can not pass to exhaust valve 301; Have only the motion at the top of integrated form exhaust boss 220 to be delivered to exhaust valve 301, it is moving to produce conventional valve elevator.
Fig. 7 has represented the lifting curve of a kind of exhaust valve in the replacement formula rocking arm braking device of the present utility model and the lifting curve of intake valve.The starting point that the conventional valve of engine exhaust port rises curve 220m is 225a, and terminal point is 225b, and its top lift is approximately 220b.If there is not emptying passage 219 (Fig. 1 and Fig. 2) between the brake piston hole 190 of rocking arm 210 and the emptying piston hole 183, to rise the starting point of curve 220v be 225h to the main valve of the increasing that is produced by integrated form exhaust boss 220 during engine braking so, terminal point is 225c, and its top lift 220e is 220a and 220b sum.Because oil drain valve is by the replacement effect of emptying passage 219, the valve of exhaust valve 301 rises curve and rise curve 220m transition to main valve after the main valve that strengthens rises the bottom 220a of curve 220v and the transition point 220t between the 220b of top, rise curve 220m fusion at 220s point and main valve, when terminal point 225b ratio has the emptying passage, do not close in advance.The main valve that strengthens rises and is varied down to conventional valve after curve 220v is reset and rises curve 220m, and replacement is put 220s between 220t and 220m.
When engine braking operates, the motion of the braking boss of cam (small boss 232 and small boss 233), pass to exhaust valve 301 below the brake piston 160 by rocking arm 210 by hydraulic pressure link 234 and brake piston 160 (Fig. 2), the brake valve that the brake valve that produces exhaust gas recirculatioon shown in Figure 7 rises 232v and compresses release rises 233v.The starting point that the brake valve of exhaust gas recirculatioon rises 232v is 225d, is positioned at the later stage of the aspirating stroke of motor, just when the valve of intake valve rises curve 280v and is tending towards cutting out; The terminal point that the brake valve of exhaust gas recirculatioon rises 232v is 225e, is positioned at the early stage of the compression stroke of motor.The starting point that the brake valve that compression discharges rises 233v is 225f, is positioned at the later stage of the compression stroke of motor; The terminal point that the brake valve that compression discharges rises 233v is 225g, is positioned at the early stage of the expansion stroke of motor.Valve rises curve and circulates between 0～720 °, and 0 ° and 720 ° is same point.
When the integrated form exhaust boss 220 of cam 230 from interior basic circle 225 when rising (Fig. 7), rocking arm 210 promotes exhaust valve 301 by hydraulic pressure link 234 and brake piston 160 (Fig. 2) and moves downward.When cam 230 enters the top (greater than the top lift of small boss 233) of integrated form exhaust boss 220 (Fig. 7), the replacement supporting structure 150 that rocking arm 210 is shown in Figure 2 further away from each other.Emptying piston 170 moves on further in emptying piston hole 183, open emptying passage 219, brake piston hole 190 beginning emptyings, brake piston moves on to retracted position on the 160 relative brake piston holes 190, the valve of exhaust valve 301 rises curve and rise curve 220m transition (Fig. 7) to main valve after transition point 220t, close at terminal point 225b at last, the terminal point 225c when not unloading circulation road is leading greatly.So just reduced the lift of exhaust valve, avoided the collision of exhaust valve 301 and engine cylinder piston, also increased braking force, reduced the temperature of cylinder internal at the top dead center position of engine exhaust strokes.
Embodiment 2:
Fig. 8 has represented that second embodiment's of replacement formula rocking arm braking device of the present utility model cam 230 is in the position on the interior basic circle.Present embodiment is applied on the overhead camshaft type engine, between cam 230 and rocking arm 210 push rod is not set, so the valve clearance controlling mechanism is placed in an end of close exhaust valve 301 on the rocking arm 210.Be not provided with under the brake piston 160 and resemble sufficient pad, but act directly on the exhaust valve 301.Another difference of present embodiment and first embodiment is that the unidirectional delivery valve 172 of present embodiment is placed in the oil supply gallery 214, is biased in closed position by spring 156.One of spring 156 is sat up straight and is dropped on the valve ball, and the other end is on spring seat 157.Spring seat 157 is fixed on the rocking arm 210.
Another difference of present embodiment and first embodiment is that the oil drain valve of present embodiment is placed in the valve clearance controlling mechanism.Be placed in the emptying piston hole 183 of adjusting screw 110 emptying piston 170 sliding types.Also increased an emptying passage 197 in the adjusting screw.
When the needs engine braking, as shown in Figure 4, open braking control mechanism 50, control valve 51 is to braking drive organ 100 fuel feeding.Low-pressure oil is from oil supply gallery, and the oil feed non-return valve 172 by as shown in Figure 8 enters brake piston hole 190.Brake piston 160 brake piston hole 190 be built in extended position and with rocking arm 210 between form hydraulic pressure and link.When the braking boss of cam 230 (compression discharges boss) 233 from interior basic circle 225 when rising; rocking arm 210 clockwise rotates; drive and be in extended position in the brake piston hole 190 of rocking arm 210 and form the brake piston 160 of hydraulic pressure locking downward, opens the exhaust valve 301 below it.
In the process that cam 230 driving rocking arms 210 clockwise rotate, the valve clearance adjusting screw 110 on the rocking arm 210 is left replacement supporting structure 150 from contact position shown in Figure 8, and emptying piston 170 also up moves in emptying piston hole 183.But the design of oil drain valve makes the hypomotility of small boss 233 to open emptying passage 219.The end face 147 of emptying piston 170 still contacts with adjusting screw 1102, and emptying piston 170 is still blocked emptying passage 219.
Change the ascent stage that is higher than small boss 233 of exhaust boss 220 over to when cam 230 after; it is enough far away that the valve clearance adjusting screw 110 on the rocking arm 210 is left replacement supporting structure 150; emptying piston 170 moves on to the replacement position on emptying piston hole 183 in; emptying piston 170 is opened emptying passage 219, and emptying passage 197 and 219 emptyings are passed through in brake piston hole 190.Move on the brake piston 160, eliminate the gap 234 between adjusting screw 110 and the brake piston 160, lost by the exhaust valve motion that small boss 233 produces, the valve liter of exhaust valve 301 is reset the valve that is varied down to the conventional exhaust valve motion of not being with engine braking and rises curve.
When cam 230 turns over the extreme higher position of exhaust boss 220 and roll back down the interior basic circle 225 of cam, brake piston 160 and exhaust valves 301 brake piston 160 below under the effect of valve spring 310 the back motion of rocking arm 210 in being retracted in brake piston hole 190.Emptying piston 170 in the emptying piston hole 183 back into initial position from the replacement position, closes emptying passage 219 again.Machine oil passes through unidirectional delivery valve 172 once more, fuel feeding in brake piston hole 190, and brake piston 160 is got back to extended position from retracted position in brake piston hole 190, the braking cycle period of a beginning new round.
When not needing engine braking, as shown in Figure 5, close braking control mechanism 50, control valve 51 stops to braking drive organ 100 fuel feeding.Machine oil in the brake piston hole 190 are owing to can not get replenishing of oil feeding mechanism behind the unlatching emptying of oil drain valve, and no longer form hydraulic pressure between the rocking arm 210 and link.The motion of small boss 233 and braking boss 232 can be delivered to exhaust valve 301 because gap 234 loses, and the braking running of motor is disengaged.The transmission of movement supply and exhaust door 301 that has only exhaust boss 220 tops produces conventional exhaust valve motion.
Embodiment 3:
Fig. 9 has represented that the 3rd embodiment of replacement formula rocking arm braking device of the present utility model is in the position of " pass " at engine braking apparatus.The present embodiment and first embodiment's the main distinction is the Exhaust valve mechanism 300 of motor.The Exhaust valve mechanism 300 of present embodiment contains two exhaust valves, has therefore also increased valve bridge (being valve cross arm again) 400.Resemble foot pad 114 and act on the middle top of valve bridge 400, thereby rocking arm 210 can be opened two exhaust valves simultaneously by valve bridge 400.The spring 156 of unidirectional delivery valve 172 disposes spring seat 157 in the present embodiment.
Present embodiment is except opening simultaneously two exhaust valves when braking, and its working principle is similar to first embodiment, no longer repeats at this.
Embodiment 4:
Figure 10 has represented that the 4th embodiment of replacement formula rocking arm braking device of the present utility model is in the position of " pass " at engine braking apparatus.Present embodiment and the 3rd embodiment's the main distinction is: present embodiment is only opened among two exhaust valves when braking.Increased the valve clearance controlling mechanism of exhaust valve on the rocking arm 210.The valve clearance controlling mechanism of exhaust valve comprises by nut 105 and is locked at valve clearance adjusting screw 110 on the rocking arm 210.Be provided with below the adjusting screw 110 and resemble foot pad 1142.Resemble between foot pad 1142 and the valve bridge 400 and be provided with a gap 130.The effect in gap 130 is identical with gap 234, all is for when the normal operation of motor, the motion of skipping small boss 232 and small boss 233.
Above-mentioned explanation has disclosed a kind of new replacement formula rocking arm braking device and method.Above-mentioned mode of execution should not be regarded as the restriction to the utility model scope, but as representative concrete illustrations more of the present utility model, many other differentiation all might therefrom produce.For instance, here replacement formula rocking arm braking device and method are applicable to the motor of overhead camshaft type engine and push rod engine and single valve and the motor of dual valve simultaneously.For the motor of dual valve, can open single valve braking, also can open the dual valve braking.
Also have, unidirectional delivery valve 172 can adopt other form, as the dish valve etc.Unidirectional delivery valve 172 also can be placed in different positions, such as being placed in the brake piston 160 or in the oil supply gallery.In addition, replacement supporting structure 150 also can be other form.The structure of oil drain valve and arrangement also can be in different ways.Also have, brake piston 160 can adopt different forms, and as " H " type and T-shape, the beneath of brake piston 160 can also add shock mount, also can with resemble foot pad 114 and link to each other etc.
In addition, the form of preloading spring 198 and arrangement also can be varied.Can be helical spring, also can be leaf spring; Can be placed between rocking arm 210 and the motor, also can be placed between rocking arm 210 and the exhaust valve 301, can also be between rocking arm 210 and the valve bridge 400 or between rocking arm 210 and the push rod 201 or the like.Therefore, scope of the present utility model should not limited by above-mentioned concrete illustration, but is decided by claim.
Claims (6)
1. replacement formula rocking arm braking device, comprise the braking control mechanism, braking drive organ, exhaust valve actuator and at least one exhaust valve, described exhaust valve actuator comprises cam and rocking arm, described cam contains exhaust boss and at least one braking boss, described exhaust boss is higher than the braking boss, it is characterized in that: described braking control mechanism comprises a control valve that is connected with the hydraulic pressure generation device, described braking drive organ comprises oil feeding mechanism, emptying mechanism and brake piston, described brake piston has an extended position and a retracted position in the brake piston hole of rocking arm, the lower end of described brake piston links to each other with at least one described exhaust valve, described oil feeding mechanism comprises braking oil supply gallery and unidirectional delivery valve, the control valve of described braking control mechanism is connected with the inlet of described braking oil supply gallery, the outlet of braking oil supply gallery is connected with the brake piston hole, described unidirectional delivery valve is arranged between braking oil supply gallery and the brake piston hole, perhaps in the braking oil supply gallery, the fuel feeding direction of unidirectional delivery valve is to enter the brake piston hole from the braking oil supply gallery, described emptying mechanism comprises an oil drain valve and emptying passage, and described oil drain valve is connected with the brake piston hole by the emptying passage.
2. replacement formula rocking arm braking device as claimed in claim 1, it is characterized in that: described braking drive organ also comprises preloading spring, the gap that described preloading spring keeps retracted position and the extended position by brake piston to generate in the exhaust valve chain of motor.
3. replacement formula rocking arm braking device as claimed in claim 1, it is characterized in that: described braking drive organ also comprises position-limit mechanism, described position-limit mechanism limits the stroke of described brake piston in the brake piston hole.
4. replacement formula rocking arm braking device as claimed in claim 1, it is characterized in that: described oil drain valve comprises the emptying piston in the emptying piston hole that is arranged on the rocking arm, the relative emptying piston hole of described emptying piston has an application position and a replacement position, the bottom of described emptying piston hole is communicated with described braking oil supply gallery, the middle part of described emptying piston hole links to each other with an end of an emptying passage, the other end of described emptying passage is communicated with described brake piston hole, in described application position, the emptying piston is closed described emptying passage, in described replacement position, the emptying piston is opened described emptying passage.
5. replacement formula rocking arm braking device as claimed in claim 1, it is characterized in that: described oil drain valve comprises the emptying piston in the emptying piston hole that is arranged in the valve clearance adjusting screw, the relative emptying piston hole of described emptying piston has an application position and an emptying position, also be provided with an emptying passage in the described valve clearance adjusting screw, one end of described emptying passage links to each other with the bottom of emptying piston hole, and the other end of described emptying passage is communicated with described brake piston hole; In described application position, the emptying piston is positioned at the bottom of emptying piston hole, described emptying pathway closure, and in described replacement position, the emptying piston is positioned at the top of emptying piston hole, and described emptying passage is opened.
6. replacement formula rocking arm braking device as claimed in claim 1, it is characterized in that: described braking drive organ also comprises a replacement supporting structure, described replacement supporting structure is fixed on the motor of upside of rocking arm one end at emptying piston hole place, the motion of described replacement supporting structure restriction emptying piston in the emptying piston hole.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201120159441 CN202090977U (en) | 2011-05-18 | 2011-05-18 | Reset type rocker braking device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201120159441 CN202090977U (en) | 2011-05-18 | 2011-05-18 | Reset type rocker braking device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202090977U true CN202090977U (en) | 2011-12-28 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201120159441 Expired - Lifetime CN202090977U (en) | 2011-05-18 | 2011-05-18 | Reset type rocker braking device |
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| CN (1) | CN202090977U (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012129753A1 (en) * | 2011-03-30 | 2012-10-04 | 奚勇 | Integrated engine braking device |
| CN102787919A (en) * | 2011-05-18 | 2012-11-21 | 上海尤顺汽车部件有限公司 | Method and device for braking reset rocking arm |
| CN106968753A (en) * | 2017-04-20 | 2017-07-21 | 东风商用车有限公司 | Brake actuator and its application method for engine braking oil path |
| CN117569887A (en) * | 2024-01-17 | 2024-02-20 | 潍柴动力股份有限公司 | Engine and valve mechanism thereof |
-
2011
- 2011-05-18 CN CN 201120159441 patent/CN202090977U/en not_active Expired - Lifetime
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012129753A1 (en) * | 2011-03-30 | 2012-10-04 | 奚勇 | Integrated engine braking device |
| CN102733884A (en) * | 2011-03-30 | 2012-10-17 | 奚勇 | Integrated engine-braking device |
| CN102733884B (en) * | 2011-03-30 | 2016-02-03 | 奚勇 | A kind of engine braking apparatus of integrated form |
| CN102787919A (en) * | 2011-05-18 | 2012-11-21 | 上海尤顺汽车部件有限公司 | Method and device for braking reset rocking arm |
| WO2012155315A1 (en) * | 2011-05-18 | 2012-11-22 | 上海尤顺汽车部件有限公司 | Reset type rocker braking method and device |
| CN102787919B (en) * | 2011-05-18 | 2015-03-04 | 上海尤顺汽车部件有限公司 | Method and device for braking reset rocking arm |
| US8991350B2 (en) | 2011-05-18 | 2015-03-31 | Shanghai Universoon Auto Parts Co., Ltd. | Reset type rocker braking method and device |
| CN106968753A (en) * | 2017-04-20 | 2017-07-21 | 东风商用车有限公司 | Brake actuator and its application method for engine braking oil path |
| CN117569887A (en) * | 2024-01-17 | 2024-02-20 | 潍柴动力股份有限公司 | Engine and valve mechanism thereof |
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