WO2012113126A1

WO2012113126A1 - Method and apparatus for braking integrated exhaust engine

Info

Publication number: WO2012113126A1
Application number: PCT/CN2011/001503
Authority: WO
Inventors: 杨洲
Original assignee: 奚勇
Priority date: 2011-02-25
Filing date: 2011-09-05
Publication date: 2012-08-30
Also published as: CN102650224B; CN102650224A

Abstract

A method for braking an integrated exhaust engine. When an exhaust brake (700) of a brake control mechanism (50) is closed, the exhaust back pressure of the engine is increased. An inner exhaust valve (3001) is opened downwards by rebounding at a late stage of an intake stroke, a brake piston (160) within a valve bridge is moved to an operating position, and the inner exhaust valve (3001) is kept perpetually open at a low flow rate, the exhaust braking of the engine is thus generated. When a cam (230) of the engine drives a valve bridge (400) to open an exhaust valve (400), a support mechanism (125) integrated within a rocker arm (210) is separated from the valve bridge (400), a fluid discharging passage (197) within the valve bridge is opened, and the brake piston (160) is retracted to a non-operating position. Also provided is an apparatus for implementing the method, comprising a brake driving mechanism and a brake control mechanism. The brake driving mechanism comprises the brake piston (160), a piston-limiting mechanism (137, and 142), a fuel supplying mechanism, a fuel discharging mechanism, and the support mechanism (125). The brake piston (160) is arranged within a piston hole (190) of the valve bridge (400). The fuel discharging mechanism comprises within the valve bridge (400) the fluid discharging passage (197). The support mechanism (125) is adjustably integrated within the rocker arm (210), the bottom of the support mechanism is closely in contact with the valve bridge (400), sealing the fluid discharging passage (197). The apparatus has a simple braking principle, compact structure, and is convenient to install and to adjust.

Description

Integrated deflated engine braking method and device

Technical field

The present invention relates to the field of machinery, and more particularly to the field of valve actuation of vehicle engines, and more particularly to an integrated deflation type engine braking method and apparatus.

Background technique

Engine braking technology can be divided into in-cylinder braking and out-of-cylinder braking. In-cylinder braking of the engine requires only temporary conversion of the engine to a compressor. The fuel is cut off during the conversion process, and the exhaust valve is opened at the end of the compression stroke of the engine piston, allowing the compressed gas (air during braking) to be released, and the energy absorbed by the compressed gas during the compression stroke of the engine cannot In the subsequent expansion stroke, it returns to the engine piston, but is dissipated through the engine's exhaust and heat dissipation system. The end result is effective engine braking that slows down the speed of the vehicle.

The engine's out-of-cylinder braking technology was first available in 1956 (see US Patent No. 2730090). It uses a current limiting device, such as an exhaust butterfly valve, in the exhaust pipe of the engine to raise the exhaust back pressure of the engine. The resistance on the engine piston increases during the exhaust stroke, producing engine braking. The engine's out-of-cylinder brake is also called exhaust brake, and the exhaust butterfly valve or other exhaust restrictor is also called the exhaust brake.

The in-cylinder brake of the engine can be further divided into a compression release type brake and a deflation type brake. The engine's compression-release brake opens the exhaust valve near the end of the engine piston compression stroke, closing the exhaust valve after the end of the compression stroke (before the expansion or power stroke, the exhaust valve is normally open). A precedent for compression-release brakes is disclosed by Cummins in U.S. Patent No. 3,220,392, 1965. The brake system passes the mechanical input through the hydraulic circuit to the exhaust valve to be opened. The hydraulic circuit typically includes a primary piston that reciprocates within the primary piston bore from a mechanical input of the engine, such as movement of the engine fuel injection cam or movement of an adjacent exhaust cam. The movement of the main piston is transmitted to the secondary piston on the hydraulic circuit through the hydraulic fluid to reciprocate in the secondary piston bore, and the secondary piston acts directly or indirectly on the exhaust valve to generate the engine brake operation. Valve movement.

The deflated brake of the engine is that the exhaust valve maintains a small amount of constant opening (partial periodic deflation braking) during a partial cycle, or during a period of non-exhaust stroke (intake stroke, compression stroke, in addition to normal opening). And the expansion or power stroke) keep a small amount of constant opening (full cycle deflation brake). The main difference between partial cycle bleed brake and full cycle bleed brake is that the former does not open the exhaust valve during most of the intake stroke. The inventors have provided related descriptions and examples for the deflated engine braking system and method in U.S. Patent No. 6,594,996.

A precedent for the engine full cycle bleed brake system is disclosed by Muir in 1970 in U.S. Patent No. 3,525,317. The brake system divides the engine brake into three gears. The first gear is the brake generated by the friction loss caused by the engine and the moving parts of the vehicle. The second gear is the full cycle bleed brake generated by keeping the exhaust valve of the engine continuously for a small amount of constant opening. The third gear is to add an exhaust butterfly valve based on the full-cycle deflation brake of the second gear to generate a combined brake.

An engine partial cycle deflation brake system is disclosed in U.S. Patent No. 5,086, 838, to Mann (M1N). When the engine is braked, the exhaust valve is slightly opened at the end of the engine intake stroke, then remains constant throughout the entire compression stroke, and finally closed at the beginning of the expansion or power stroke.

Engine bleed-type brakes are typically used in conjunction with engine exhaust brakes (such as exhaust butterfly valves) to form a combined brake. Using an exhaust butterfly valve or other exhaust restrictor to raise the exhaust back pressure may cause the exhaust valve to bounce or float (floating valve). The engine industry generally disapproves of the float valve because the opening and closing of the exhaust valve during the float valve is not driven by the cam, and the seating speed of the valve cannot be controlled. Too large a valve seating speed may damage the engine. However, in U.S. Patent No. 4,848,289, the disclosure of U.S. Pat. .

A combined braking method for compression-release engine braking and exhaust brakes is disclosed in Volvo, Sweden, in U.S. Patent No. 5,146,890. Among them, the brake cam of the engine adds an exhaust gas recirculation (EGR) boss in addition to the compression release brake boss. In this way, the exhaust valve opens near the bottom dead center of the intake stroke, and the high back is generated by the exhaust brake. Pressing the exhaust gas (air during braking), refilling the engine cylinder from the exhaust pipe to increase the compression braking power. U.S. Patent No. 5,692,469, issued to U. When the exhaust back pressure is high enough, the exhaust valve floats or bounces near the end of the intake stroke. During the floating of the exhaust valve, it is intervened by a brake device, that is, it is intercepted by a hydraulically controlled piston before the floating exhaust valve is closed, preventing it from closing, keeping it small The constant opening causes a partial cycle bleed brake (the exhaust valve closes after the exhaust stroke). The brake system is an engine for a single exhaust valve per cylinder. In 2006, German Man (M1N) (US Patent No. 7013867, Chinese Patent No. 200310123153.7) extended the above technology to an engine with a double exhaust valve per cylinder.

The reliability and durability of the above-mentioned deflated engine brake system of the German (M1N) face many problems because it relies on the intermittent opening or floating of the brake exhaust valve, which is inconsistent in time and size. . It is well known that the floating height of the exhaust valve is dependent on the exhaust back pressure, which is dependent on the engine speed and is affected by the quality and control of the exhaust brake and the design of the exhaust manifold. At medium and low speeds, the exhaust valve may not float enough or not at all, and the launching mechanism cannot be activated. At this time, the demand for engine braking is high because the engine is mostly used at such a speed. In addition, excessive exhaust back pressure not only floats the braked exhaust valve (outer valve), but also floats the non-braking exhaust valve (internal valve). The seating speed of the inner valve will be too large, affecting the reliability and durability of the engine. Also, the deflated engine brake requires an additional bracket for withstanding the braking load and for unloading the engine brake. This additional bracket (support mechanism) is separate from the engine's exhaust valve drive system, making the design of the engine difficult. Not only is it inconvenient to install and commission, it is also possible to increase the height and weight of the engine.

Summary of the invention

The object of the present invention is to provide an integrated deflation type engine braking method, which solves the reliability and durability of the deflated engine braking technology in the prior art. Poor sex, inconvenient installation and commissioning, and increased technical issues such as engine height and weight. The integrated deflation type engine braking method of the present invention includes a process of opening and closing an inner exhaust valve of a motor by using a brake control mechanism, a cam, a rocker arm and a valve bridge, the brake control mechanism Including an exhaust brake, the valve bridge is provided with a discharge passage and a piston hole, a piston piston is disposed in the piston hole, and the brake piston has a piston hole in the piston hole a non-operating position and an operating position, wherein the rocker arm is integrated with a supporting mechanism, and the lower side of the supporting mechanism abuts the valve bridge and closes the unloading passage in the valve bridge, and is characterized in that: During the opening and closing of the inner exhaust valve of the brake control mechanism, the cam, the rocker arm and the wide bridge drive engine, the exhaust brake is used to limit the airflow in the exhaust pipe of the engine, and the exhaust back pressure in the exhaust pipe of the engine is increased. Using the exhaust back pressure to move the inner exhaust valve downward when the cam is in the inner base circle position and the cylinder piston of the engine is near the end of the intake stroke a gap is formed between the inner exhaust valve and the cylinder seat of the engine, and the brake piston extends from the non-operating position and locks to the operating position following the inner exhaust valve in the piston hole of the valve bridge, The position of the inner exhaust valve and the gap are maintained. When the cam is turned from the inner base circle to the conventional exhaust boss, the movement of the cam is transmitted to the valve bridge by the rocker arm, and the valve bridge is driven to move downward and The wide bridge is separated from the support mechanism integrated in the rocker arm, and the unloading passage in the valve bridge is unloaded, and the brake piston is retracted into the non-operating position in the valve bridge. When the cam continues to drive the valve bridge to move downward, the valve The bridge opens the inner and outer exhaust valves of the engine. When the cam rotates past the conventional exhaust boss and returns to the inner base circle, the inner and outer exhaust valves close, and the rocker and valve bridge are reset. The support mechanism integrated in the rocker arm re-closes the valve bridge and closes the unloading passage in the valve bridge to start a new braking cycle.

Further, the process of opening and closing the inner exhaust valve of the engine by using the brake control mechanism, the cam, the rocker arm and the valve bridge comprises the following steps:

1) opening the brake control mechanism, closing the exhaust brake to increase the exhaust back pressure in the engine exhaust pipe,

2) When the cam is in the inner base circle position and the cylinder piston of the engine is near the end of the intake stroke, the exhaust gas back pressure is used to overcome the spring force and the cylinder pressure on the inner exhaust valve, and the inner exhaust valve is driven. Open a gap down,

3) The brake piston extends from the non-operating position and locks to the operating position following the inner exhaust valve in the piston bore of the valve bridge.

4) Hold the open inner exhaust valve with the brake piston in the operating position that is extended downward to maintain the gap between the inner exhaust valve and the inner exhaust valve.

5) The cam continues to rotate along the inner base circle. The cylinder piston of the engine keeps the inner exhaust valve from the end of the intake stroke, through the entire compression stroke and most of the power stroke, using the brake piston locked in the operating position. The open gap creates an engine bleed-type brake.

6) The cam is turned from the inner base circle to the conventional exhaust boss, the cam drive valve bridge moves downward, the valve bridge is separated from the support mechanism integrated in the rocker arm, and the unloading passage in the valve bridge is opened to discharge.

7) The brake piston is retracted from the operating position back to the inoperative position within the piston bore of the valve bridge,

8) The cam continues to drive the valve bridge to move downwards, and the valve bridge opens the inner and outer exhaust valves together.

9) The cam rotates past the conventional exhaust boss, returns to the inner base circle, the exhaust valve closes, and the braking process returns to step 2) to start a new brake cycle.

10) Turn off the brake control mechanism, open the exhaust brake, release the restriction on the airflow in the engine exhaust pipe, and release the engine brake operation to return to the normal ignition operation.

The present invention also provides an integrated deflation type engine brake device, the integrated deflation type engine brake device comprising a brake drive mechanism and a brake control mechanism, the engine including a cam, a rocker An arm, a rocker shaft, a valve bridge, an inner exhaust valve and an outer exhaust valve, the inner exhaust valve being adjacent to the rocker shaft, the outer exhaust valve being offset from the rocker shaft, wherein the brake The driving mechanism includes a brake piston, a piston limiting mechanism, an oil supply mechanism, an oil discharge mechanism and a supporting mechanism, and the brake piston is disposed above the inner exhaust valve and located in a piston hole in the valve bridge, the piston a limiting mechanism limits movement between the inoperative position and the operating position of the brake piston within the piston bore, the oil supply mechanism being coupled to a piston bore in the valve bridge, the oil discharge mechanism including a setting a discharge passage in the valve bridge, the discharge passage is in communication with a piston hole in the valve bridge, the support mechanism is integrally disposed in the rocker arm, and the lower end of the support mechanism closes the discharge passage The brake control mechanism includes an exhaust brake, and the exhaust brake has a closed position and an open position.

Further, the oil discharge mechanism has an oil supply position and an oil discharge position, and in the oil supply position, the support mechanism abuts the valve bridge, and in the oil discharge position, the The support mechanism is separated from the valve bridge.

Further, the oil supply mechanism includes a one-way oil supply and an oil supply flow passage, and the one-way oil supply valve is disposed between the oil supply flow passage and the brake piston.

Further, the oil supply mechanism is integrated with the support mechanism, the oil supply mechanism includes a one-way oil supply valve, and the one-way oil supply valve is disposed in the support mechanism.

Further, the brake driving mechanism further includes a pressure relief mechanism.

Further, the brake driving mechanism further includes an automatic valve clearance adjusting mechanism. Further, the brake control mechanism further includes a variable exhaust valve spring mechanism disposed on the inner exhaust valve, wherein the variable exhaust valve spring mechanism includes a variable exhaust valve a spring force, the variable exhaust valve spring force includes at least two stages of exhaust valve spring force, and the two-stage exhaust valve spring force includes a brake spring force and a non-braking spring Acting force, the non-braking spring force is equivalent to the force of the conventional exhaust valve spring on the outer exhaust valve, and the braking spring force is smaller than the non-braking spring force The inner exhaust valve is subjected to a spring force of the brake during the rise of the brake valve.

Further, the variable exhaust valve spring mechanism includes two exhaust valve springs acting on the inner exhaust valve, and the combined action of the two exhaust valve springs on the inner exhaust valve The force is equivalent to the force of a conventional exhaust valve spring on the outer exhaust valve, wherein only one exhaust valve spring applies a spring force to the inner exhaust valve during the brake valve lift.

Further, the variable exhaust valve spring mechanism includes an inner spring and an outer spring sleeved on the inner exhaust valve, the outer spring is longer than the inner spring, and the outer spring is at the brake valve Applying a spring force to the inner exhaust valve during the lift, the inner spring does not apply a spring force to the inner exhaust valve during the rise of the brake valve, and the combined force of the outer spring and the inner spring on the inner exhaust valve Exhaust The force of the conventional exhaust valve spring on the door is equal.

Further, the supporting mechanism is adjustably integrated in the rocker arm, and the supporting mechanism comprises an adjusting screw fixed on the rocker arm by a nut, and the adjusting screw is connected with the elephant foot pad, like the lower end of the foot pad Close the valve bridge and close the outlet of the unloading channel in the valve bridge.

Further, the supporting mechanism supporting mechanism is adjustably integrated in the rocker arm, and the supporting mechanism comprises an adjusting screw fixed on the rocker arm by a nut, and an oil supply piston is arranged under the adjusting screw to supply oil The inside of the piston contains an oil supply passage and a one-way oil supply valve, and the lower end of the oil supply piston abuts the valve bridge and closes the outlet of the discharge passage in the valve bridge

The working principle of the present invention is: When the engine brake is required, the brake control mechanism is slammed, the exhaust brake is closed, and the exhaust back pressure in the engine exhaust pipe upstream of the exhaust brake is increased. When the engine cylinder pressure is low and the exhaust back pressure is high (near the engine cylinder intake stroke end, the exhaust cam is located on the inner base circle, the exhaust rocker arm and the valve bridge are in a relatively stationary position), The force exerted by the air back pressure on the inner exhaust valve overcomes the force of the exhaust valve spring and the cylinder pressure, causing the inner exhaust valve to rebound downward. A brake piston located on the inner exhaust valve moves from the inoperative position to the operating position following the inner exhaust valve in the piston bore of the valve bridge. The low-pressure engine oil of the engine supplies oil from the oil supply flow path and the one-way oil supply valve to the brake piston hole, and the oil is filled with a gap formed downward by the brake piston. Since the one-way oil supply valve does not allow the fluid to flow backward, the discharge flow passage is closed by the support mechanism, a hydraulic link is formed between the brake piston and the valve bridge, the brake piston is locked in the operating position, and the internal exhaust gas that will be reversed downward is opened. Hold the door and let it fall back to the seat. From the end of the engine's intake stroke, through the entire compression stroke and most of the power stroke, the inner exhaust valve always maintains a small amount of constant enthalpy, resulting in a deflated engine brake. The brake load is transmitted from the inner exhaust valve through the brake piston, the hydraulic link formed between the brake piston and the valve bridge, the wide bridge, the support mechanism and the rocker arm to the cam at the inner base circle position. When the cam is turned from the inner base circle to the conventional exhaust boss, the cam drives the valve bridge to move downward. The valve bridge is separated from the support mechanism, and the unloading passage is opened to discharge oil. The brake piston is retracted from the operating position to the inoperative position. The valve bridge opens and closes the two exhaust valves together under the push of the cam. The cam rotates past the conventional exhaust boss and returns to the inner base circle, with the braking cycle starting from the beginning. Such a braking cycle, repeated cycles until braking The control mechanism is turned off. At this time, the exhaust brake (butterfly valve) is opened, the exhaust back pressure in the engine exhaust pipe upstream of the exhaust brake is lowered, and the exhaust valve cannot be reversely opened (the force of the exhaust valve spring is much larger than the brake spring). The moving piston is in the non-operating position in the piston hole of the valve bridge, and the engine exits the braking state and returns to the ignition state.

The effect of the present invention is positive and significant compared to the prior art. The invention integrates the entire deflation type brake mechanism into the existing valve drive chain of the engine, has a compact structure, reduces the weight and height of the engine, simplifies the engine brake device, and increases the reliability and durability of the engine operation.

DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic illustration of a first embodiment of an integrated bleed-type engine brake apparatus of the present invention in its "off" position.

Figure 2 is a schematic illustration of the first embodiment of the integrated bleed-type engine brake device of the present invention in its "open" position.

Figure 3 is a schematic illustration of the second embodiment of the integrated bleed-type engine brake of the present invention in its "off" position.

Figure 4 is a schematic illustration of the second embodiment of the integrated bleed-type engine brake device of the present invention in its "open" position.

Figure 5 is a schematic illustration of a third embodiment of the integrated bleed-type engine brake device of the present invention in its "off" position.

Figure 6 is a schematic illustration of a third embodiment of the integrated bleed-type engine brake device of the present invention in its "open" position.

detailed description

Example 1

As shown in Figures 1 and 2, the first embodiment of the integrated bleed-type engine brake of the present invention is in its "off" and "open" positions, respectively. The figure includes four main components: exhaust valve actuator 200, exhaust valve 300 (including inner exhaust valve 3001 and outer exhaust valve 3002), starting The mechanism drives the drive mechanism 100 and the engine brake control mechanism 50.

The exhaust valve actuator 200 includes a cam 230, a cam follower 235, a rocker arm 210, and a valve bridge 400. A lash adjustment system is typically provided at one end of the rocker arm 210 (on the side of the valve bridge or on the side near the cam). In the present embodiment, a valve clearance adjusting screw 110 is disposed on one side of the valve bridge 400, and the valve clearance adjusting screw 110 is located on the rocker arm 210 and fixed by the locking nut 105. The valve clearance adjusting screw 110 is coupled to the foot pad 1 14 such that the foot pad 114 is centrally located above the wide bridge 400. The rocker arm 210 is swingably mounted on the rocker shaft 205, and the valve bridge 400 spans the inner exhaust valve 3001 and the outer exhaust valve 3002. The cam 230 has a conventional boss 220 on the inner base circle 225 for normal operation of the engine.

The inner exhaust valve 3001 and the outer exhaust valve 3002 are respectively placed on the valve seat 320 in the engine block 500 by a valve spring 3101 and a valve spring 3102 (referred to as a valve spring 310) to block gas (air during engine braking). The flow between the engine cylinders and the exhaust pipe 600. The exhaust valve actuator 200 transmits the mechanical movement of the cam 230 through the wide bridge 400 to the inner exhaust valve 3001 and the outer exhaust valve 3002 to periodically open and close. The inner exhaust valve 3001 is adjacent to the rocker shaft 205, and the outer exhaust valve 3002 is moved away from or away from the rocker shaft 205.

The brake drive mechanism 100 includes a brake piston 160. Brake piston 160 is disposed within inner exhaust valve 3001 and piston bore 190 of valve bridge 400 and is movable between an inoperative position (Fig. 1) and an operational position (Fig. 2). The positioning pin 137 fixed in the valve bridge 400 and the limiting groove 142 on the brake piston 160 form a piston limiting mechanism. The piston limit mechanism controls the distance 234 between the inoperative position and the operating position of the brake piston 160. A brake spring 177 is disposed between the brake piston 160 and the wide bridge 400, and the force of the brake spring 177 is much smaller than the force of the valve spring 3101.

The brake drive mechanism 100 also includes an oil supply mechanism. The oil supply mechanism includes a one-way oil supply valve 172 and an oil supply flow path. The one-way fuel supply valve 172 is located within the wide bridge 400. The oil supply passage supplies oil to the high pressure flow passage 412 and the brake piston 160 through the one-way oil supply valve 172. The oil supply passage includes an axial hole 211 and a radial hole 212 in the rocker shaft 205, a slit 213 and an oil passage 214 in the rocker arm 210, and a horizontal hole 113 and a vertical hole 115 in the adjusting screw 110. . One-way fuel supply valve 172 only allows engine Low pressure lubricating oil enters the bore 190 of the brake piston 160 from the oil supply passage.

The brake drive mechanism 100 also includes a support mechanism 125. The support mechanism 125 is adjustably integrated within the rocker arm 210 and includes an adjustment screw 1102 that is secured to the rocker arm 210 by a nut 1052. The adjustment screw 1102 is coupled to the elephant foot pad 1 142. The underside of the footpad 1 142 abuts the valve bridge 400, closing the relief passage 197 in the valve bridge.

The brake drive mechanism 100 also includes an oil discharge mechanism. The oil discharge mechanism includes a discharge passage (or discharge orifice) 197 in the valve bridge 400. The oil discharge mechanism includes an oil supply position and an oil discharge position. In the oil supply position (Fig. 1 and Fig. 2), the support mechanism 125 abuts the valve bridge 400 to close the discharge passage 197; in the unloading position, the support mechanism 125 and the valve The bridge 400 is separated and the unloading channel 197 is opened. The unloading position of the oil discharge mechanism is formed by the exhaust valve actuator 200 pushing the valve bridge 400 and the exhaust valve 300 downward to move the support mechanism 125 (like the foot pad 1142) apart from the valve bridge 400.

The brake control mechanism 50 includes an exhaust brake, such as an exhaust butterfly valve 700. The exhaust butterfly valve 700 includes a valve plate 702 that rotates about a valve shaft 704. The drive unit 750 of the brake control mechanism 50 turns off and on the exhaust brake (e.g., the exhaust butterfly valve 700) based on the control signal given by the control unit 800.

When engine braking is required, the brake control mechanism 50 is opened, the exhaust brake 700 is closed, the airflow in the exhaust tail pipe 710 is restricted, and the engine exhaust pipe upstream of the exhaust brake 700 (including the exhaust pipe 610, the exhaust pipe) The exhaust back pressure in the 620 and the exhaust pipe 630, etc. is increased. When the engine cylinder pressure is low and the exhaust back pressure is high (near the end of the intake stroke, the exhaust cam 230 is located on the inner base circle 225, and the exhaust rocker arm 210 and the valve bridge 400 are in a relatively stationary position). The force exerted by the exhaust back pressure on the exhaust valve 300 overcomes the force of the exhaust valve spring 310 and the cylinder pressure, causing the exhaust valve to rebound a small amount to open 330 (Fig. 2). The gaps 330 are similar to 234. The brake piston 160 located on the inner exhaust valve 3001 follows the inner exhaust valve 3001 in the piston bore 190 of the valve bridge from the inoperative position (Fig. 1) to the operating position (Fig. 2). The low pressure engine oil of the engine enters the high pressure oil passage 412 from the oil supply passage through the one-way oil supply valve 172, filling the gap 234 formed by the brake piston 160 downward. Since the one-way oil supply valve 172 does not allow the fluid to flow backward, the unloading passage 197 is closed by the support mechanism 125, and a hydraulic link is formed between the brake piston 160 and the valve bridge 400, and the brake piston 160 is formed. When locked in the operating position, the inner exhaust valve 3001 that opens backwards is held against it, and is not allowed to fall back to the valve seat 320. From the end of the intake stroke of the engine, through the entire compression stroke and most of the power stroke, the inner exhaust valve 3001 is always kept at a small constant opening (gap 330), resulting in a deflated engine brake. The brake load is transmitted from the inner exhaust valve 3001 through the brake piston 160, the hydraulic link formed between the brake piston 160 and the valve bridge, the valve bridge 400, the support mechanism 125 and the rocker arm 210 to the position at the inner base circle 225. Cam 230.

When the cam 230 is turned from the inner base circle 225 to the conventional exhaust boss 220, the cam 230 drives the rocker arm 210 and the valve bridge 400, and the valve bridge 400 moves downward. The distance between the valve bridge 400 and the support mechanism 125 (like the foot pad 1142) increases, and the two gradually separate. The unloading passage 197 in the valve bridge 400 opens the oil discharge, and the brake piston 160 is pressed back from the operating position to the inoperative position (the force of the exhaust valve spring 3101 is much larger than the brake spring 177). The valve bridge 400 opens and closes the inner exhaust valve 3001 and the outer exhaust valve 3002 under the push of the cam 230 and the rocker arm 210. The cam 230 rotates past the conventional exhaust boss 220 and returns to the inner base circle 225. The braking cycle begins from the beginning and is repeated until the brake control mechanism 50 is closed. At this time, the exhaust brake (butterfly valve) is opened, the airflow in the exhaust tail pipe 710 is not restricted, and the engine exhaust pipe (exhaust pipe 610, exhaust pipe 620, exhaust pipe 630, etc.) upstream of the exhaust brake is inside. The exhaust back pressure is reduced, the exhaust valve cannot be reversely opened (the force of the exhaust valve spring 3101 is much greater than the brake spring 177), and the brake piston 160 is in the non-operating position in the piston bore of the valve bridge (Fig. 1). , the engine exits the braking state and returns to the ignition state.

Example 2:

As shown in Figures 3 and 4, the second embodiment of the integrated bleed-type engine brake of the present invention is in its "off" and "open" positions, respectively. The main differences between this embodiment and the first embodiment are:

1. Added automatic valve clearance adjustment mechanism. The automatic valve clearance adjustment mechanism includes an adjustment piston 162 and an adjustment spring 166. The adjustment piston 162 is located within the central opening of the valve bridge 400 that opens upwardly. The adjustment spring 166 is located between the adjustment piston 162 and the valve bridge 400, biasing the adjustment piston 162 upwardly against the foot pad 1 14 . The one-way oil supply valve of the oil supply mechanism is located inside the regulating piston 162. Adjustment piston 162 A valve gap 130 is disposed between the valve bridge 400 and the valve bridge 400. The wide gap 130 is smaller than the stroke 234 of the brake piston 160 (the distance between the non-operating position and the operating position), and is mainly used to adjust the thermal expansion and contraction of the inner exhaust valve 3001 and the outer exhaust valve 3002, and the cam 230 is maintained. The predetermined position between the rocker arm 210 and the valve bridge 400 when the base circle 225 is positioned, so that the underside of the support mechanism 125 integrated in the rocker arm 210 (like the foot pad 1142) abuts the valve bridge 400, and the unloading in the closed valve bridge Flow channel 197.

2. Added pressure relief mechanism. The pressure relief mechanism includes a pressure relief hole 152 in the brake piston 160. When the oil pressure in the bore 190 of the brake piston 160 is increased, the oil leakage through the gap between the brake piston 160 and the bore 190, the positioning groove 137 on the brake piston 160, and the pressure relief hole 152 is increased. The oil pressure acting on the brake piston 160 does not exceed a predetermined value designed.

3. A variable exhaust valve spring mechanism is added to the inner exhaust valve 3001 that is subjected to the braking load. The variable exhaust valve spring mechanism contains a variable exhaust valve spring force. The variable exhaust valve spring force includes at least two stages of exhaust valve spring force. The two-stage exhaust valve spring force includes a brake spring force and a non-braking spring force. The non-braking spring force is equivalent to the force of the conventional exhaust valve spring on the outer exhaust valve 3002. The inner exhaust valve 3001 receives a brake spring force that is less than the non-braking spring force during the brake valve lift. The variable exhaust valve spring mechanism of the present embodiment includes an exhaust valve spring 3101 (outer spring) and an exhaust valve spring 312 acting on the inner exhaust valve 3001.

(inside spring). A spacing 131 (Fig. 3) is provided between the inner spring 312 and the spring seat 3021. The spacing 131 is approximately the same as the brake valve lift 330 (Fig. 4) (generally less than 2 mm). Thus, the inner spring 312 does not apply a spring force to the inner exhaust valve 3001 during the brake valve lift, and the inner exhaust valve 3001 only receives the force of the outer spring 3101. Since the force of the outer spring 3101 is smaller than the force of the conventional exhaust valve spring (e.g., 3102), the inner exhaust valve 3001 receives a spring force that is less than the spring force received by the outer exhaust valve 3002 during the brake valve lift. However, once the lift of the inner exhaust valve 3001 exceeds the brake lift 131 (or the brake valve rises 330), the combined force of the exhaust valve spring 3101 and the exhaust valve spring 312 on the inner exhaust valve 3001 (non-made) The dynamic spring force is equivalent to the force of the conventional exhaust valve spring 3102 on the outer exhaust valve 3002, thereby ensuring equalized movement of the inner exhaust valve 3001 and the outer exhaust valve 3002. When engine braking is required, the brake control mechanism 50 is opened, the exhaust brake is closed, the airflow in the exhaust tail pipe 710 is restricted, and the engine exhaust pipe (exhaust pipe 610, exhaust pipe 620, and row) upstream of the exhaust brake The exhaust back pressure in the gas pipe 630 or the like is increased. When the engine cylinder pressure is low and the exhaust back pressure is high (near the end of the intake stroke, the exhaust cam 230 is located on the inner base circle 225, and the exhaust rocker arm 210 and the valve bridge 400 are in a relatively stationary position) The exhaust back pressure acts on the inner exhaust valve 3001 against the force of the outer spring 3101 and the cylinder pressure, causing the inner exhaust valve 3001 to rebound a small amount to open 330 (Fig. 4). The brake piston 160 located on the inner exhaust valve 3001 moves downwardly from the inoperative position (Fig. 3) to the operative position (Fig. 4) within the piston bore 190 of the valve bridge 400. The low pressure engine oil of the engine enters the high pressure oil passage 412 from the oil supply passage through the one-way oil supply valve 172, filling the gap 234 formed by the brake piston 160 downward. Since the one-way oil supply valve 172 does not allow the fluid to flow backward, the unloading passage 197 is closed by the support mechanism 125, a hydraulic link is formed between the brake piston 160 and the valve bridge 400, and the brake piston 160 is locked in the operating position, which will reverse the direction. The lower open inner exhaust valve 3001 is held against it and is not allowed to fall back to the valve seat 320. From the end of the intake stroke of the engine, through the entire compression stroke and most of the power stroke, the inner exhaust valve 3001 is always kept at a small constant opening (gap 330), resulting in a deflated engine brake. The brake load is transmitted from the inner exhaust valve 3001 through the brake piston 160, the hydraulic link formed between the brake piston 160 and the valve bridge, the valve bridge 400, the support mechanism 125 and the rocker arm 210 to the position at the inner base circle 225. Cam 230.

When the cam 230 is turned from the inner base circle 225 to the conventional exhaust boss 220, the cam 230 drives the rocker arm 210 and the valve bridge 400, and the valve bridge 400 moves downward. The distance between the valve bridge 400 and the support mechanism 125 (like the foot pad 1142) increases, and the two gradually separate. The unloading passage 197 in the wide bridge 400 opens the unloading oil, and the brake piston 160 is pressed back from the operating position to the inoperative position (the force of the exhaust valve spring 3101 is much larger than the brake spring 177). The valve bridge 400 simultaneously opens and closes the inner exhaust valve 3001 and the outer exhaust valve 3002 under the push of the cam 230 and the rocker arm 210. The cam 230 is rotated past the conventional exhaust boss 220, back to the inner base circle 225, and the braking cycle is repeated from the beginning, and the cycle is repeated until the brake control mechanism 50 is closed.

Since the force of the spring 3102 received by the outer exhaust valve 3002 is greater than that of the inner exhaust valve 3001 The force of the outer spring 3101, when the inner exhaust valve 3001 is rebounded due to the increase in the exhaust back pressure, the outer exhaust valve 3002 does not rebound or the rebound is reduced. Thus, while the inner exhaust valve 3001 is more likely to open the brake, the outer exhaust valve 3002 is less likely to open, thereby reducing its seating speed and increasing the reliability and durability of the engine.

Example 3:

As shown in Figures 5 and 6, the third embodiment of the integrated bleed-type engine brake of the present invention is in its "off" and "open" positions, respectively. The oil supply mechanism of this embodiment is integrated with the support mechanism 125. The adjusting screw 1102 of the support mechanism 125 has an oil supply piston 162 inside. The oil supply piston 162 has a hydraulic flow passage 115 communicating with the hydraulic flow passage 214 in the rocker arm 210 by adjusting the transverse oil hole 113 in the screw 1102. A one-way oil supply valve 172 is disposed in the hydraulic flow passage 115. In addition, the discharge passage 197 in the valve bridge 400 is also an oil supply passage. A seal 173 disposed in the end face of the oil supply piston 162 prevents leakage due to uneven or misaligned contact surfaces.

When engine braking is required, the brake control mechanism 50 is opened, the exhaust brake is closed, the airflow in the exhaust tail pipe 710 is restricted, and the engine exhaust pipe (exhaust pipe 610, exhaust pipe 620, and row) upstream of the exhaust brake The exhaust back pressure in the gas pipe 630 or the like is increased. When the engine cylinder pressure is low and the exhaust back pressure is high (near the end of the intake stroke, the exhaust cam 230 is located on the inner base circle 225, and the exhaust rocker arm 210 and the valve bridge 400 are in a relatively stationary position) The exhaust back pressure acts on the inner exhaust valve 3001 against the force of the outer spring 3101 and the cylinder pressure, causing the inner exhaust valve 3001 to rebound a small amount to open 330 (Fig. 6). The brake piston 160 located on the inner exhaust valve 3001 moves downwardly from the inoperative position (Fig. 5) to the operative position (Fig. 6) within the piston bore 190 of the valve bridge 400. The low-pressure engine oil of the engine directly enters the bore 190 of the brake piston 160 from the oil supply passage 1 15 and the one-way oil supply valve 172 in the support mechanism 125 and the discharge passage 197 in the valve bridge 400, filling the brake piston 160 downward. A gap 234 is formed. Since the one-way oil supply valve 172 does not allow the fluid to flow backward, the unloading passage 197 is closed by the support mechanism 125, a hydraulic link is formed between the brake piston 160 and the valve bridge 400, and the brake piston 160 is locked in the operating position, which will reverse the direction. The lower open inner exhaust valve 3001 is held against it and is not allowed to fall back to the valve seat 320. From the end of the engine's intake stroke, after the entire compression For most of the power strokes, the inner exhaust valve 3001 is always kept at a small amount and constant opening (gap 330), resulting in a deflated engine brake. The brake load is transmitted from the inner exhaust valve 3001 through the brake piston 160, the hydraulic link formed between the brake piston 160 and the support mechanism 125, the valve bridge 400, the support mechanism 125 and the rocker arm 210, to the position of the inner base circle 225. Cam 230.

When the cam 230 is turned from the inner base circle 225 to the conventional exhaust boss 220, the cam 230 drives the rocker arm 210 and the valve bridge 400, and the valve bridge 400 moves downward. The distance between the valve bridge 400 and the support mechanism 125 (like the foot pad 1142) increases. The oil supply piston 162 in the support mechanism 125 slides down under oil pressure (or a spring can be added thereto if necessary). The sliding distance of the oil supply piston 162 is determined by a snap ring 176 mounted inside the piston. After the descent, the fuel supply piston 162 will block the cross hole 1 13 in the adjusting screw 1102 and stop supplying oil to the one-way oil supply valve 172. Thus, when the oil supply piston 162 is separated from the discharge passage 197 in the valve bridge 400, the oil from the oil supply passage does not leak outward. However, once the unloading passage 197 in the valve bridge 400 is opened and the oil is unloaded, the brake piston 160 is pressed back from the operating position to the inoperative position (the force of the exhaust valve spring 3101 is much greater than the brake spring 177). The valve bridge 400, driven by the cam 230 and the rocker arm 210, simultaneously opens and closes the two exhaust valves 3001 and 3002. The cam 230 rotates past the conventional exhaust boss 220 and returns to the inner base circle 225. The braking cycle begins from the beginning and is repeated until the brake control mechanism 50 is closed.

The above description discloses a new integrated deflated engine brake device and method. The many specific embodiments described above are not to be considered as limiting the scope of the invention, but rather as some specific examples of the invention, many other variations are possible. For example, the integrated deflated engine brakes and methods here can be used not only for overhead cam engines but also for pusher engines.

Also, the exhaust brake of the brake control mechanism may be not only an exhaust butterfly valve but also other types of current limiting devices such as a variable geometry turbocharger. As long as it can increase the exhaust back pressure function of the engine.

In addition, the one-way oil supply can be a ball valve or other types of valves, such as a disc valve. Also, the brake piston 160 can be varied, such as "H" type and "T" type. Also, the automatic valve clearance adjusting mechanism used in Embodiment 2 can be applied to other embodiments. In addition, the variable exhaust valve spring mechanism on the inner exhaust valve for braking may also take various forms, and may be a spring or a plurality of springs, and may be a coil spring or other form of spring, as long as it can be realized. The spring force on the exhaust valve during the valve lift (approximately 0 to 2 mm) is less than the spring force on the conventional exhaust valve (outer exhaust valve), and during the valve lift above the brake valve rise, the action The spring force on the inner and outer exhaust valves is approximately the same.

Therefore, the scope of the invention should not be determined by the specific examples described above, but by the claims.

Claims

Claim

An integrated deflation type engine braking method comprising a process of driving an internal exhaust valve opening and closing of a motor by a brake control mechanism, a cam, a rocker arm and a valve bridge, the brake control mechanism comprising An exhaust brake, wherein the valve bridge is provided with a discharge passage and a piston hole, wherein the piston hole is provided with a brake piston, and the brake piston has a non-in the piston hole An operating position and an operating position, wherein a rocking arm is integrated with a supporting mechanism, and the lower side of the supporting mechanism abuts the wide bridge and closes the unloading passage in the valve bridge, and is characterized by: The internal control valve, the cam, the rocker arm and the valve bridge drive the internal exhaust valve of the engine to open and close, use the exhaust brake to limit the airflow in the exhaust pipe of the engine, and improve the exhaust back pressure in the exhaust pipe of the engine Using the exhaust back pressure to move the inner exhaust valve downward when the cam is in the inner base circle position and the cylinder piston of the engine is near the end of the intake stroke A gap is created between the inner exhaust valve and the cylinder seat of the engine, and the brake piston extends downward from the inoperative position and locks in the operating position following the inner exhaust valve in the piston bore of the valve bridge. Holding the position of the inner exhaust valve and the gap, when the cam is turned from the inner base circle to the conventional exhaust boss, the movement of the cam is transmitted to the valve bridge by the rocker arm, and the valve bridge is driven to move downward and Separating the valve bridge from the support mechanism integrated in the rocker arm, opening the unloading passage in the valve bridge to unload, and the brake piston retracting into the non-operating position in the valve bridge, when the cam continues to drive the valve bridge to move downward, The valve bridge opens the inner and outer exhaust valves of the engine. When the cam rotates past the conventional exhaust boss and returns to the inner base circle, the inner and outer exhaust valves close, and the rocker and valve bridge are reset. The support mechanism integrated in the rocker arm re-closes the valve bridge and closes the unloading passage in the valve bridge to start a new braking cycle.

2. The integrated deflation type engine braking method according to claim 1, wherein: said inner exhaust valve of said engine is opened and closed by a brake control mechanism, a cam, a rocker arm and a valve bridge. The process includes the following steps:

1) opening the brake control mechanism, closing the exhaust brake to increase exhaust back pressure in the engine exhaust pipe, 2) when the cam is in the inner base circle position and the cylinder piston of the engine is near the end of the intake stroke, the exhaust gas back pressure is used to overcome the spring force and cylinder pressure on the inner exhaust valve, and the inner exhaust valve is driven to Open a gap,

4) The brake inner piston in the operating position, which is extended downward, is used to press the open inner exhaust valve to maintain the gap opened by the inner exhaust valve.

5) The cam continues to rotate along the inner base circle. The cylinder piston of the engine maintains the inner exhaust valve by the brake piston locked in the operating position from the end of the intake stroke, through the entire compression stroke and most of the power stroke. The open gap creates an engine bleed-type brake.

6) The cam is turned from the inner base circle to the conventional exhaust boss, the cam drive valve bridge moves downward, the valve bridge is separated from the support mechanism integrated in the rocker arm, and the unloading passage in the valve bridge is opened to unload the oil.

7) The brake piston is retracted from the operating position back to the non-operating position within the piston bore of the valve bridge,

9) The cam rotates past the conventional exhaust boss, returns to the inner base circle, the exhaust valve closes, and the braking process returns to step 2) to start a new braking cycle.

10) closing the brake control mechanism, opening the exhaust brake, releasing the restriction on the airflow in the exhaust pipe of the engine, reducing the exhaust back pressure in the exhaust pipe of the engine, releasing the engine brake operation, and returning to the conventional ignition Operation.

3. An integrated deflated engine brake device comprising a brake drive mechanism and a brake control mechanism, the engine comprising a cam, a rocker arm, a rocker shaft, a valve bridge and an inner exhaust valve and an outer An exhaust valve, the inner exhaust valve is adjacent to the rocker shaft, and the outer exhaust valve is offset from the rocker shaft, wherein: the brake drive mechanism comprises a brake piston, a piston limit mechanism, An oil mechanism, an oil discharge mechanism and a support mechanism, the brake piston is disposed above the inner exhaust valve and located in a piston hole in the valve bridge, and the piston limiting mechanism limits the brake piston in the piston hole Movement between the inoperative position and the operating position, the oil supply mechanism and the valve bridge The piston hole is connected, the oil discharge mechanism includes a discharge passage disposed in the valve bridge, the discharge passage is in communication with a piston hole in the valve bridge, and the support mechanism is integrally disposed on the rocker arm The lower end of the support mechanism closes the outlet of the unloading passage, the brake control mechanism includes an exhaust brake, and the exhaust brake has a closed position and an open position.

4. The integrated bleed type engine brake apparatus according to claim 3, wherein: said oil discharge mechanism has an oil supply position and an oil discharge position, and said oil supply position is The support mechanism abuts the valve bridge, and in the unloading position, the support mechanism is separated from the valve bridge.

5. The integrated deflation type engine brake device according to claim 3, wherein: said oil supply mechanism comprises a one-way oil supply valve and an oil supply flow path, and said one-way oil supply valve is disposed Between the oil supply passage and the brake piston.

6. The integrated deflation type engine brake device according to claim 3, wherein: said oil supply mechanism is integrated with said support mechanism, said oil supply mechanism includes a one-way oil supply valve The one-way oil supply valve is disposed in the support mechanism.

7. The integrated bleed-type engine brake apparatus according to claim 3, wherein: said brake drive mechanism further includes a pressure relief mechanism.

8. The integrated bleed-type engine brake apparatus according to claim 3, wherein: said brake drive mechanism further includes an automatic valve clearance adjustment mechanism.

9. The integrated deflation type engine brake device according to claim 3, wherein: said brake control mechanism further comprises a variable exhaust gas disposed on said inner exhaust valve a door spring mechanism, the variable exhaust valve spring mechanism includes a variable exhaust valve spring force, and the variable exhaust valve spring force includes at least two stages of exhaust valve spring force, the two The stage exhaust valve spring force includes a brake spring force and a non-braking spring force, and the non-braking spring force acts on the outer exhaust valve spring on the outer exhaust valve The force of the brake spring is smaller than the non-braking spring force, and the inner exhaust valve receives the spring force of the brake during the rise of the brake valve.

10. The integrated deflation type engine brake device according to claim 9, wherein: said variable exhaust valve spring mechanism comprises two exhaust valves acting on said inner exhaust valve a spring, the combined force of the two exhaust valve springs on the inner exhaust valve is equivalent to the force of a conventional exhaust valve spring on the outer exhaust valve, wherein only one exhaust valve spring is at the brake valve A spring force is applied to the inner exhaust valve during the rise.

11. The integrated bleed-type engine brake apparatus according to claim 9, wherein: said variable exhaust valve spring mechanism comprises an inner spring and an outer sleeve that are sleeved on said inner exhaust valve a spring, the outer spring being longer than the inner spring, the outer spring applying a spring force to the inner exhaust valve during the rise of the brake valve, and the combined force of the outer spring and the inner spring on the inner exhaust valve The force of the conventional exhaust valve spring on the outer exhaust valve is equal.

12. The integrated bleed-type engine brake device according to claim 3, wherein: said support mechanism is adjustably integrated in said rocker arm, said support mechanism comprising a nut fixed at An adjusting screw on the rocker arm, the adjusting screw is connected to the foot pad, like the lower end of the foot pad abutting the valve bridge and closing the outlet of the unloading channel in the valve bridge.

13. The integrated deflation type engine brake device according to claim 3, wherein: said support mechanism is adjustably integrated in said rocker arm, said support mechanism comprising a nut fixed at The adjusting screw on the rocker arm is provided with an oil supply piston under the adjusting screw. The oil supply piston internally has an oil supply passage and a one-way oil supply valve. The lower end of the oil supply piston abuts the valve bridge and closes the discharge passage in the valve bridge. Export.