CN110566308B - Reset slide valve type rocker arm mechanism for engine braking and braking method thereof - Google Patents
Reset slide valve type rocker arm mechanism for engine braking and braking method thereof Download PDFInfo
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- CN110566308B CN110566308B CN201910829155.9A CN201910829155A CN110566308B CN 110566308 B CN110566308 B CN 110566308B CN 201910829155 A CN201910829155 A CN 201910829155A CN 110566308 B CN110566308 B CN 110566308B
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- valve core
- oil
- control
- mounting hole
- rocker arm
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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
- F01L1/20—Adjusting or compensating clearance
- F01L1/22—Adjusting or compensating clearance automatically, e.g. mechanically
- F01L1/24—Adjusting or compensating clearance automatically, e.g. mechanically by fluid means, e.g. hydraulically
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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
Abstract
The invention discloses a reset slide valve type rocker arm mechanism for engine braking and a braking method thereof, wherein the reset slide valve type rocker arm mechanism comprises a control mechanism, an oil filling mechanism, a rocker arm body and a driven mechanism; the rocker arm body is provided with a control mechanism, an oil filling mechanism and a driven mechanism; the switching of the working mode of the engine is controlled by controlling the on-off of an external electromagnetic valve; the electromagnetic valve is switched on, the engine enters a braking mode, a control valve core in the control mechanism is pushed by high-pressure oil to move downwards, the slide valve core further moves downwards under the action of spring force to isolate an oil supply duct and a pressure duct, the driven mechanism forms a closed space, the oil in the oil duct of the closed space pushes the driven mechanism to move under the action of the cam, an exhaust valve directly connected with the driven mechanism is opened, and compressed gas is released, so that effective engine braking is generated, and the speed of a vehicle is reduced. The invention has high integration level, simple control, reliability and effectiveness.
Description
Technical Field
The invention relates to the field of engine braking, in particular to a reset slide valve type rocker arm mechanism for engine braking and a braking method thereof.
Background
With the improvement of road conditions and the development of automobile technology, the engine power of modern automobiles is higher and higher, and the friction inside the automobile and the air resistance of the automobile body are smaller and smaller, which means that the deceleration capacity of the automobile is reduced. On the other hand, the domestic heavy-duty truck often has the overload phenomenon, and when long slope, frequently use the stopper often can cause the stopper overheated wearing and tearing even inefficacy. Therefore, the main braking system, which is the service braking of the automobile, cannot meet the braking requirement of the automobile under high speed and heavy load, and an auxiliary braking mechanism must be added to ensure the braking safety performance of the automobile.
When the engine is braked, when the compression stroke of the engine is close to the top dead center, the exhaust valve is opened by a small lift (1-2mm) under the driving of the engine braking mechanism, the compressed high-pressure gas in the cylinder is rapidly released, the pressure in the cylinder is rapidly reduced, so that the energy of the power stroke is reduced, therefore, in the next power stroke, the engine does not work outwards basically, the engine is decelerated, and the braking in the engine cylinder is realized.
U.S. cornins (Cummins) proposed a hydraulic engine brake and was disclosed in 1965 (U.S. patent No. 3120392). This is a precedent for the engine braking device. The engine brake system is an accessory which is arranged on an engine in an overhead mode, and a small valve is added to the engine and is specially used for engine braking. In this technique, the engine brake transmits mechanical input to the exhaust valve to be opened by hydraulic transmission. The hydraulic circuit typically includes a master piston reciprocating in a master piston bore, the reciprocating motion resulting from mechanical input to the engine, such as rocking of an injection rocker arm, the motion of the master piston being hydraulically transferred to a slave piston on the hydraulic circuit to reciprocate in a slave piston bore, the slave piston acting directly or indirectly on an exhaust valve to produce valve actuation for engine braking operation. To install such an engine brake, a gasket is added between the cylinder and the valve cover, which additionally increases the height, weight, and cost of the engine;
the engine brake device is integrated in the conventional rocker arm, so that the rocker arm is compact in structure and light in weight, and the engine brake device disclosed by Chery automobile GmbH with the application number of 200810024409.2 is easy to control, but needs to be additionally provided with a cam switching device, and is relatively high in manufacturing and assembling cost; and the opening time and height of the brake valve is very short when the engine is braked, the time available for resetting is more limited.
Disclosure of Invention
The invention aims to provide a reset slide valve type rocker arm mechanism for engine braking and a braking method thereof, aiming at overcoming the defects in the prior art, and the efficiency of the engine during exhaust braking can be effectively improved.
The invention firstly discloses a reset slide valve type rocker arm mechanism for engine braking, which comprises a rocker arm body, a control mechanism, an oil filling mechanism and a driven mechanism.
The rocker arm body is arranged on the rocker arm shaft through a middle through hole, and the rocker arm shaft is further arranged on the rocker arm bracket by using a fixing bolt;
the control mechanism is arranged in the middle of the rocker arm body and is communicated with the driven mechanism and the oil filling mechanism through a pressure oil duct in the rocker arm body, the top end of the control mechanism is also connected with a control oil duct which is controlled by an externally connected electromagnetic valve, the bottom of the control mechanism is connected with an oil supply oil duct, and an engine hydraulic oil supply system provides oil pressure;
the oil filling mechanism is arranged in the middle part of the rocker arm body and is used for supplying engine oil for the pressure oil duct;
and the driven mechanism is arranged in the other end of the rocker arm body and used for driving the exhaust valve to open and close, and meanwhile, the driven mechanism mounting hole is connected with the control mechanism mounting hole through the pressure oil duct.
As the preferred scheme of the invention, a driven mechanism mounting hole, a control mechanism mounting hole and an oil charging mechanism mounting hole for mounting a driven mechanism, a control mechanism and an oil charging mechanism are respectively arranged in the rocker arm body; the rocker arm body is also provided with a pressure oil duct, an oil supply oil duct and a control oil duct; the pressure oil duct is sequentially communicated with the driven mechanism mounting hole, the control mechanism mounting hole and the oil charging mechanism mounting hole from front to back; the oil supply channel is a three-way channel, the front end of the oil supply channel is communicated with the control mechanism mounting hole, the upper end of the oil supply channel is communicated with the bottom of the oil charging mechanism mounting hole, and the rear end of the oil supply channel is communicated with a hydraulic oil supply system of the engine; one end of the control oil duct is communicated with the upper part of the control mechanism mounting hole, and the other end of the control oil duct is communicated with an external electromagnetic valve oil way;
the oil filling mechanism is arranged in the oil filling mechanism mounting hole, the driven mechanism is arranged in the driven mechanism mounting hole, and the control mechanism is arranged in the control mechanism mounting hole.
The electromagnetic valve is a two-position three-way electromagnetic valve.
In a preferred embodiment of the invention, a roller is mounted on the rocker arm body at the end remote from the driven means by means of a roller shaft, said roller being in constant contact with the engine cam for transmitting movement during each stroke of the cam.
As the preferred scheme of the invention, the control mechanism comprises a stop ring, a clamp spring, a control valve core return spring, a slide valve core and a slide valve core return spring; the top end of the control mechanism mounting hole is sealed by a sealing device; the control valve core is of a cylindrical structure with an open lower end and is arranged between the sealing device and the sliding valve core; the upper end of the sliding valve core is of an open tubular structure, the lower end of the sliding valve core is of a stepped shaft structure with a small lower part and a large upper part, and the diameter of the sliding valve core is smaller than the inner diameter of the tubular structure of the control valve core; the upper end of the control valve core return spring is abutted with the upper bottom surface of the control valve core cylindrical structure, the lower end of the control valve core return spring is abutted with the lower bottom surface of the slide valve core cylindrical structure, and the outer diameter of the control valve core return spring is smaller than the inner diameter of the slide valve core cylindrical structure; the stop ring and the clamp spring are arranged at the bottom end of the control mechanism mounting hole in a matched mode and used for limiting the displacement of the return spring of the sliding valve core; the upper end of the spool return spring is abutted against a step surface formed by the spool stepped shaft, the lower end of the spool return spring is abutted against the stop ring, and the elastic coefficient of the spool return spring is greater than that of the control spool return spring.
And a grinding wheel overrun groove is arranged in the control mechanism mounting hole, and the groove wall at the lower end of the grinding wheel overrun groove can be used for limiting the stroke of the control valve core.
A slender throttling ring groove is processed in the middle of the sliding valve core, the lower end of the sliding valve core extends out of the control mechanism mounting hole, and the extending part is supported on the rocker arm bracket; the sliding valve core is matched with the rocker arm body to move up and down relative to the control mechanism mounting hole, when a throttling ring groove in the middle of the sliding valve core is communicated with the pressure oil duct, the oil supply duct is communicated with the pressure oil duct, and when the throttling ring groove is not communicated with the pressure oil duct, the oil supply duct is separated from the pressure oil duct.
As the preferred scheme of the invention, the oil filling mechanism comprises a one-way valve return spring, a one-way valve and a one-way valve seat; the top end of the mounting hole of the oil filling mechanism is sealed by a sealing device; the upper end of the one-way valve return spring is abutted against the lower end face of the sealing device, and the lower end of the one-way valve return spring is abutted against the one-way valve; the check valve is arranged at the bottom of the mounting hole of the oil filling mechanism through a check valve seat; in the oil filling process, engine oil in the oil supply oil duct jacks up the one-way valve and flows into the pressure oil duct.
As a preferable aspect of the present invention, the follower mechanism includes an adjusting bolt, a gap adjusting nut, a follower plunger spring, a follower plunger, and a elephant foot; the clearance adjusting nut and the adjusting bolt are arranged above the driven mechanism mounting hole in a threaded fit mode, and meanwhile the clearance adjusting nut and the adjusting bolt are matched for adjusting and fixing the driven mechanism; the driven plunger is arranged under the adjusting bolt, the upper end of the driven plunger is of an open tubular structure, and the lower end of the driven plunger is a spherical contact head; the spherical contact head is connected with the elephant foot, and the elephant foot is directly connected with an exhaust valve of the engine in a contact mode.
The driven mechanism further comprises a driven plunger spring, the driven plunger spring is sleeved on the adjusting bolt, the lower end of the driven plunger spring is abutted to the lower bottom surface of the driven plunger tubular structure, and the outer diameter of the driven plunger spring is smaller than the inner diameter of the driven plunger tubular structure.
The invention also discloses a braking method of the reset slide valve type rocker arm mechanism for engine braking, which comprises the following steps:
when the electromagnetic valve is switched on, the engine is switched from a normal working mode to a braking mode, high-pressure oil is filled in the control oil channel, the control valve core moves downwards to abut against the wall of a grinding wheel overtravel groove in the mounting hole of the control mechanism, a return spring of the control valve core is stressed and compressed to push the slide valve core to move downwards, so that a throttling ring groove on the slide valve core is not communicated with a pressure oil channel any more, the oil supply oil channel is separated from the pressure oil channel, a driven mechanism forms a closed space, and the interior of; when the camshaft rotates to the cam braking lift range, the rocker arm body drives the driven mechanism to move downwards, and the driven plunger moves downwards along with the rocker arm body because engine oil in the closed space of the driven mechanism cannot be compressed, so that the elephant foot connected with the lower end of the driven plunger pushes the exhaust valve to open, compressed air is discharged, and the speed of a vehicle is reduced;
when the electromagnetic valve is closed, the engine is switched from a braking mode to a normal working mode, the control oil duct communicated with the electromagnetic valve drains oil, the control valve core is jacked up under the action of a control valve core return spring to be contacted with the sealing device, further, the slide valve core moves upwards under the action of the slide valve core return spring, so that the throttling ring groove on the slide valve core is communicated with the pressure oil duct again, the oil supply oil duct is communicated with the pressure oil duct, and the driven plunger slowly returns under the action of the spring force of the exhaust valve; when the cam shaft rotates to the cam exhaust lift, the driven plunger is returned and integrated with the rocker arm body, the whole exhaust process is consistent with the normal exhaust process, and only when the cam rotates to the normal exhaust angle, the driven plunger can push the exhaust valve to open for exhaust.
Compared with the prior art, the invention has the following beneficial effects:
(1) the invention has high integration design, greatly reduces the weight and the volume of the whole machine on the basis of realizing the braking of the engine, occupies small space and has high practicability; and the combined structure is adopted, so that the installation is convenient.
(2) The invention adopts the electromagnetic valve to switch the working modes, the electromagnetic valve is directly communicated with the control oil way, and when the electromagnetic valve is opened, the high-pressure oil in the control oil way pushes the control mechanism to work, thereby achieving the purpose of braking.
(3) According to the invention, the throttle ring groove is designed on the sliding valve core, when the throttle ring groove of the sliding valve core moves to the oil supply duct and the pressure oil duct to be communicated, the driven plunger starts to return, and when the sliding valve core is processed, the return time of the driven plunger can be controlled by controlling the depth of the throttle ring groove, so that the driven plunger slowly returns, and mechanical damage and reduction of braking power caused by too fast return are avoided; different engines can be adapted through different processing degrees, and different braking powers can be provided.
Drawings
FIG. 1 is an isometric view of the mechanism of the present invention in its entirety;
FIG. 2 is a general cross-sectional view of the mechanism of the present invention;
FIG. 3 is a schematic view of the rocker arm body of the present invention;
FIG. 4 is a schematic view of the follower mechanism of the present invention;
FIG. 5 is a detailed schematic view of the control mechanism of the present invention in its normal operating mode;
FIG. 6 is a detailed schematic of the control mechanism in the braking mode of the present invention;
FIG. 7 is an enlarged schematic view of a spool restriction of the present invention;
FIG. 8 is a schematic view of the oil fill mechanism of the present invention in the braking mode;
in the figure: 1-driven mechanism, 11-adjusting bolt, 12-gap adjusting nut, 13-driven plunger spring, 14-driven plunger, 15-elephant foot, 2-control mechanism, 21-baffle ring, 22-snap spring, 23-control valve core, 24-control valve core return spring, 25-slide valve core, 26-slide valve core return spring, 3-oil filling mechanism, 31-one-way valve return spring, 32-one-way valve, 33-one-way valve seat, 4-rocker arm body, 41-pressure oil duct, 42-oil supply oil duct, 43-control oil duct, 44-driven mechanism mounting hole, 45-control mechanism mounting hole, 46-oil filling mechanism mounting hole, 51-roller and 52-roller shaft.
Detailed Description
In order to facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. The preferred embodiments of the present invention are shown in the drawings, but the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.
For convenience of description, an end close to the exhaust valve is defined as an "inboard end", and an end far from the exhaust valve is defined as an "outboard end".
As shown in fig. 1, an embodiment of the present invention provides a reset slide valve type rocker arm mechanism for engine braking, which includes a rocker arm body 4, a control mechanism 2, an oil filling mechanism 3, and a driven mechanism 1.
As shown in fig. 3, a driven mechanism mounting hole 44, a control mechanism mounting hole 45 and an oil filling mechanism mounting hole 46 are formed in the rocker arm body 4, and a pressure oil passage 41, an oil supply oil passage 42 and a control oil passage 43 are formed in the rocker arm body 4; wherein, the pressure oil duct 41 is connected with a driven mechanism mounting hole 44, a control mechanism mounting hole 45 and an oil charging mechanism mounting hole 46 in sequence from the inner side end to the outer side end; the inner side end of the oil supply channel 42 is connected with the control mechanism mounting hole 45, the outer side end is connected with the oil charging mechanism mounting hole 46, and oil pressure is provided by a hydraulic oil supply system of the engine; one end of the control oil duct 43 is connected with the control mechanism mounting hole 45, and the other end is connected with an external solenoid valve oil path.
As shown in fig. 2 and 3, the rocker arm body 4 is mounted on the engine rocker shaft through a through hole in the middle; a roller 51 and a roller shaft 52 which are attached to the outer end of the rocker arm 4, always kept in contact with the cam, and used for transmitting the motion from the cam; the control mechanism 2 is arranged in a control mechanism mounting hole 45 in the inner side end of the rocker arm body 4 and is communicated with the driven mechanism 1 and the oil filling mechanism 3 through a pressure oil duct 41, the top end of the control mechanism 2 is also connected with a control oil duct 43 which is controlled by an externally connected electromagnetic valve, the bottom of the control mechanism is connected with an oil supply oil duct 42, and oil pressure is provided by an engine hydraulic oil supply system; the oil filling mechanism 3 is arranged in an oil filling mechanism mounting hole 46 in the inner side end of the rocker arm body 4 and used for supplying engine oil for the pressure oil duct 41; the driven mechanism 1 is mounted in a driven mechanism mounting hole 44 at the inner end of the rocker arm body 4 and used for driving the exhaust valve to open and close, and meanwhile, the driven mechanism mounting hole 44 is connected with a control mechanism mounting hole 45 through a pressure oil channel 41.
As shown in fig. 1 and 2, the roller 51 is always in contact with the engine cam, and can transmit motion well in each stroke of the cam, so as to drive the reset slide valve type rocker arm mechanism to move around the rocker shaft, and complete the functions of braking exhaust and normal exhaust.
As shown in fig. 4, wherein the follower mechanism 1 includes an adjusting bolt 11, a gap adjusting nut 12, a follower plunger spring 13, a follower plunger 14, and a elephant foot 15; the clearance adjusting nut 12 and the adjusting bolt 11 are installed above the driven mechanism installation hole 44 in a threaded fit mode, and meanwhile the clearance adjusting nut and the adjusting bolt are matched for positioning and fixing the driven mechanism; the driven plunger 14 is a cylindrical structure with an open upper end, and the lower end is a spherical contact head connected with the elephant foot 15; the elephant foot 15 is in direct contact with the engine exhaust valve. It is further noted that the driven plunger spring 13 is sleeved on the adjusting bolt 11, and the diameter of the driven plunger spring 13 is smaller than the inner diameter of the cylindrical structure of the driven plunger 14.
As shown in fig. 5, the control mechanism 2 includes a stop ring 21, a snap spring 22, a control valve core 23, a control valve core return spring 24, a spool 25, and a spool return spring 26; the top end of the control mechanism mounting hole 45 is sealed by a sealing device; the upper end of the slide valve core 25 is of an open tubular structure, and the lower end of the slide valve core is of a stepped shaft structure with a small lower part and a big upper part; the control valve core 23 is a cylindrical structure with an open lower end and is arranged between the sealing device and the sliding valve core 25; the upper end of a control valve core return spring 24 is contacted with the inner end surface of the control valve core 23, and the lower end is contacted with the cylindrical inner end surface of a sliding valve core 25; the upper end of the slide valve core return spring 26 is contacted with a step surface formed by a step shaft of the slide valve core 25, and the lower end is contacted with the stop ring 21; the baffle ring 21 and the clamp spring 22 are arranged at the bottom end of the control mechanism mounting hole 45 in a matched mode and used for limiting the displacement of the sliding valve core return spring 26; further, the lower end of the spool 25 is supported on the rocker arm bracket, and the motion of the rocker arm body 4 is matched to achieve the effect of communicating or separating the oil supply passage 42 and the pressure passage 41.
As shown in fig. 5 and fig. 6, it should be noted that the two drawings show the structural position form of the control mechanism 2 in different working states of the engine; in fig. 5, the control valve core 23 is located at the upper part of the cavity at the top end of the control mechanism mounting hole 45, which is the normal operating mode state of the engine, while in fig. 6, the control valve core 23 is located at the lower part of the cavity at the top end of the control mechanism mounting hole 45, which is the braking mode state of the engine.
As shown in fig. 7, an elongated throttle ring groove is formed in the middle of the spool 25, and the design is a key part for communicating or blocking the oil supply passage 42 and the pressure passage 41; when the throttle ring groove in the middle of the spool is connected to the pressure oil duct 41, the oil supply duct 42 is connected to the pressure oil duct 41, and when the throttle ring groove is not connected to the pressure oil duct 41, the oil supply duct 42 is separated from the pressure oil duct 41, for example, the pressure oil duct 41 and the oil supply duct 42 in the overall cross-sectional view of fig. 2 are in a separated state, for example, the pressure oil duct 41 and the oil supply duct 42 in fig. 5 and 6 are in a connected state, where fig. 6 is a control mechanism state at a certain time in the braking mode, and at this time, the pressure oil duct 41 and the oil supply duct 42 are in a connected state; in the normal operation mode, the oil supply passage 42 and the pressure passage 41 are always in communication with each other. When the two oil passages are communicated, the oil in the pressure oil passage 41 flows back to the oil supply oil passage 42 due to the elastic force of the valve spring, so that the driven plunger 14 is slowly returned, and mechanical damage and reduction of braking power caused by too fast return are avoided. Furthermore, by designing and processing the throttling ring groove, the throttling ring groove can adapt to different engines and provide different braking powers.
As shown in fig. 8, the oil-filling mechanism 3 includes a check valve return spring 31, a check valve 32, and a check valve seat 33; wherein the top end of the oil filling mechanism mounting hole 46 is sealed by a sealing device; the upper end of the one-way valve return spring 31 is contacted with the end face of the sealing device, and the lower end of the one-way valve return spring is propped against the one-way valve 32; the one-way valve 32 is placed on a hollow ring of the one-way valve seat 33 and is tightly attached; the one-way valve seat 33 is installed at the lower end of the oil filling mechanism installation hole. Further, a through hole connected with the oil supply oil passage 42 is formed below the oil filling mechanism mounting hole 46, and in the oil filling process, the engine oil jacks up the check valve 32 and flows into the pressure oil passage 41 to complete oil filling.
The working process of the invention is as follows:
when the engine is in a normal working mode, the electromagnetic valve is in a disconnected state, and the oil supply duct 42 is always ensured to be communicated with the pressure oil duct 41;
when the electromagnetic valve is switched on, the engine is switched from a normal working mode to a braking mode; the control oil duct 43 communicated with the electromagnetic valve is filled with high-pressure oil, the control valve core 23 is pushed to move downwards until the control valve core 23 is abutted against the groove wall of the grinding wheel overtravel groove in the control mechanism mounting hole 45, the further pressed control valve core return spring 24 pushes the slide valve core 25 to move downwards to separate the oil supply oil duct 42 from the pressure oil duct 41, the driven mechanism 1 forms a closed space, and the interior of the closed space is filled with engine oil; when the camshaft rotates to the cam braking lift range, the rocker arm drives the driven mechanism 1 to move downwards, because the liquid can not be compressed, the engine oil in the pressure oil duct 41 can push the driven plunger 14 to move downwards along with the rocker arm body 4, the driven plunger 14 is connected with the elephant foot 15, and therefore the elephant foot 15 pushes the exhaust valve to open, compressed air is discharged, and the speed of a vehicle is reduced; at this stage, the bottom of the spool 25 is supported on the rocker arm bracket, so that the spool 25 is continuously pushed into the control mechanism mounting hole 45, but the throttling ring groove in the middle of the spool is not always communicated with the pressure oil duct 41, and the oil supply duct and the pressure oil duct are always in a cut-off state at this stage;
as shown in fig. 4, 6 and 7, after the camshaft rotates out of the cam braking lift, the spool 25 is continuously pushed into the control mechanism mounting hole 45, the entire spool 25 moves upward relative to the rocker arm body so that the throttling ring groove in the middle of the spool is communicated with the pressure oil duct 41, the oil supply oil duct 42 is communicated with the pressure oil duct 41 again, and thus the driven plunger 14 slowly returns until the inner end surface pushes against the lower end surface of the adjusting bolt 11 under the action of the exhaust valve spring force;
when the camshaft rotates to the cam exhaust lift, the driven plunger 14 is returned and is integrated with the rocker arm body 4, so that the whole exhaust process is consistent with the normal exhaust process;
after the exhaust is finished, as shown in fig. 8, when the camshaft is rotated to the cam oil filling lift, the rocker arm body drives the adjusting bolt to move upwards, the cavity between the adjusting bolt and the driven plunger is enlarged, so that the oil pressure of the pressure oil duct is reduced, in the process, the slide valve core 25 moves downwards relative to the rocker arm body 4, the throttling ring groove in the middle of the slide valve core is not communicated with the pressure oil duct, the oil supply oil duct 42 and the pressure oil duct 41 are cut off again, so that the driven mechanism 1 forms a closed space, the oil pressure in the pressure oil duct 41 is smaller than the oil pressure in the oil supply oil duct 42 due to the spring force action of the driven plunger spring 13, the oil filling mechanism 3 works, the one-way valve 32 is jacked up under the action of the pressure difference, the oil supply oil duct 42 supplements the pressure oil duct 41, the oil.
As shown in fig. 5, when the electromagnetic valve is closed, the engine is switched from the braking mode to the normal operation mode, the control oil duct 43 communicated with the electromagnetic valve drains oil, the control valve core 23 is jacked up to contact with the end face of the sealing device under the action of the control valve core return spring 24, further, the slide valve core 25 moves upwards under the action of the slide valve core return spring 26, the oil supply oil duct 42 is always ensured to be communicated with the pressure oil duct 41, and the driven plunger 14 can only push the exhaust valve to open when the cam rotates to a normal exhaust angle.
The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.
Claims (8)
1. A reset spool rocker mechanism for engine braking, comprising:
the rocker arm body (4) is arranged on the rocker arm shaft, and the rocker arm shaft is further arranged on the rocker arm bracket by using a fixing bolt;
the control mechanism (2) is arranged in the middle of the rocker arm body (4), is communicated with the driven mechanism (1) and the oil filling mechanism (3) through a pressure oil duct (41) in the rocker arm body, the top end of the control mechanism (2) is also connected with a control oil duct (43) and is controlled by an external electromagnetic valve, and the bottom of the control mechanism is connected with an oil supply oil duct (42) which is used for providing oil pressure by an engine hydraulic oil supply system;
the oil filling mechanism (3) is arranged in the middle part of the rocker arm body (4) and is used for supplying engine oil for the pressure oil duct (41);
the driven mechanism (1) is arranged in the other end of the rocker arm body (4) and used for driving an exhaust valve to open and close, and meanwhile, a driven mechanism mounting hole (44) is connected with a control mechanism mounting hole (45) through the pressure oil duct (41);
the control mechanism (2) comprises a stop ring (21), a clamp spring (22), a control valve core (23), a control valve core return spring (24), a sliding valve core (25) and a sliding valve core return spring (26); the top end of the control mechanism mounting hole is sealed by a sealing device; the control valve core is of a cylindrical structure with an open lower end and is arranged between the sealing device and the sliding valve core; the upper end of the sliding valve core is of an open tubular structure, the lower end of the sliding valve core is of a stepped shaft structure with a small lower part and a large upper part, and the diameter of the sliding valve core is smaller than the inner diameter of the tubular structure of the control valve core; the upper end of the control valve core return spring is abutted with the upper bottom surface of the control valve core cylindrical structure, the lower end of the control valve core return spring is abutted with the lower bottom surface of the slide valve core cylindrical structure, and the outer diameter of the control valve core return spring is smaller than the inner diameter of the slide valve core cylindrical structure; the stop ring and the clamp spring are arranged at the bottom end of the control mechanism mounting hole in a matched mode and used for limiting the displacement of the return spring of the sliding valve core; the upper end of the sliding valve core return spring is abutted against a step surface formed by the sliding valve core stepped shaft, the lower end of the sliding valve core return spring is abutted against the stop ring, and the elastic coefficient of the sliding valve core return spring is greater than that of the control valve core return spring;
a slender throttling ring groove is processed in the middle of the sliding valve core (25), the lower end of the sliding valve core (25) extends out of the control mechanism mounting hole, and the extending part is supported on the rocker arm bracket; the slide valve core is matched with the rocker arm body (4) to move up and down relative to the control mechanism mounting hole, when a throttling ring groove in the middle of the slide valve core is communicated with the pressure oil duct (41), the oil supply duct (42) is communicated with the pressure oil duct (41), and when the throttling ring groove is not communicated with the pressure oil duct (41), the oil supply duct (42) is separated from the pressure oil duct (41).
2. The reset spool valve type rocker arm mechanism for engine braking according to claim 1, wherein a follower mechanism mounting hole (44), a control mechanism mounting hole (45) and an oil filling mechanism mounting hole (46) for mounting a follower mechanism, a control mechanism and an oil filling mechanism are respectively formed in the rocker arm body; a pressure oil duct (41), an oil supply oil duct (42) and a control oil duct (43) are further processed in the rocker arm body; the pressure oil duct is sequentially communicated with the driven mechanism mounting hole, the control mechanism mounting hole and the oil charging mechanism mounting hole from front to back; the oil supply channel is a three-way channel, the front end of the oil supply channel is communicated with the control mechanism mounting hole, the upper end of the oil supply channel is communicated with the bottom of the oil charging mechanism mounting hole, and the rear end of the oil supply channel is communicated with a hydraulic oil supply system of the engine; one end of the control oil duct is communicated with the upper part of the control mechanism mounting hole, and the other end of the control oil duct is communicated with an external electromagnetic valve oil way;
the oil filling mechanism (3) is arranged in the oil filling mechanism mounting hole, the driven mechanism (1) is arranged in the driven mechanism mounting hole, and the control mechanism (2) is arranged in the control mechanism mounting hole.
3. A reset spool valve rocker mechanism for engine braking as claimed in claim 1 characterised in that a roller (51) is mounted on the rocker body at the end remote from the follower by a roller shaft (52), the roller being in constant contact with the engine cam for transmitting motion on each stroke of the cam.
4. The reset spool valve rocker mechanism for engine braking of claim 1 wherein the control mechanism mounting hole (45) has a grinding wheel over-travel slot therein, the slot wall at the lower end of the grinding wheel over-travel slot being adapted to limit the travel of the control valve spool.
5. The reset spool rocker mechanism for engine braking according to claim 1, characterized in that the oil-filled mechanism (3) comprises a one-way valve return spring (31), a one-way valve (32), a one-way valve seat (33); the top end of the oil filling mechanism mounting hole (46) is sealed by a sealing device; the upper end of the one-way valve return spring (31) is abutted against the lower end face of the sealing device, and the lower end of the one-way valve return spring is abutted against the one-way valve; the check valve is arranged at the bottom of the mounting hole of the oil filling mechanism through a check valve seat; during oil filling, the engine oil in the oil supply oil passage jacks up the check valve and flows into the pressure oil passage (41).
6. The reset spool valve rocker mechanism for engine braking as claimed in claim 1, characterized in that the follower mechanism (1) comprises an adjusting bolt (11), a lash adjusting nut (12), a follower plunger spring (13), a follower plunger (14) and a elephant foot (15); the clearance adjusting nut (12) and the adjusting bolt (11) are installed above the driven mechanism installation hole (44) in a threaded fit mode, and meanwhile, the clearance adjusting nut and the adjusting bolt are matched for adjusting and fixing the driven mechanism; the driven plunger (14) is arranged right below the adjusting bolt, the upper end of the driven plunger is of an open tubular structure, and the lower end of the driven plunger is a spherical contact head; the spherical contact head is connected with the elephant foot (15), and the elephant foot (15) is directly connected with an engine exhaust valve in a contact mode.
7. The reset spool type rocker mechanism for engine braking as set forth in claim 6, characterized in that said follower mechanism further comprises a follower plunger spring (13) fitted over the adjusting bolt, the lower end of the follower plunger spring abutting against the lower bottom surface of said follower plunger cylindrical structure, and the outer diameter of said follower plunger spring (13) being smaller than the inner diameter of the follower plunger (14) cylindrical structure.
8. A method of braking a reset spool rocker mechanism for engine braking as claimed in claim 1 wherein:
when the electromagnetic valve is switched on, the engine is switched from a normal working mode to a braking mode, high-pressure oil is filled in the control oil duct (43), the control valve core (23) moves downwards to abut against the groove wall of a grinding wheel overtravel groove in the control mechanism mounting hole (45), the control valve core return spring (24) is stressed and compressed to push the slide valve core (25) to move downwards, so that a throttling ring groove on the slide valve core is not communicated with the pressure oil duct (41), the oil supply duct (42) is separated from the pressure oil duct (41), the driven mechanism (1) forms a closed space, and the interior of the closed space is filled with engine oil; when the camshaft rotates to the cam braking lift range, the rocker arm body drives the driven mechanism (1) to move downwards, and because engine oil in the closed space of the driven mechanism cannot be compressed, the driven plunger (14) moves downwards along with the rocker arm body (4), so that the elephant foot (15) connected with the lower end of the driven plunger pushes an exhaust valve to open, compressed air is discharged, and the speed of a vehicle is reduced;
when the electromagnetic valve is closed, the engine is switched from a braking mode to a normal working mode, oil is drained from a control oil duct (43) communicated with the electromagnetic valve, a control valve core (23) is jacked up to be contacted with a sealing device under the action of a control valve core return spring (24), further, a slide valve core (25) moves upwards under the action of a slide valve core return spring (26), so that a throttling ring groove in the slide valve core is communicated with a pressure oil duct (41) again, an oil supply oil duct (42) is communicated with the pressure oil duct (41), and a driven plunger (14) slowly returns under the action of an exhaust valve spring force; when the camshaft rotates to the cam exhaust lift, the driven plunger (14) is returned and integrated with the rocker arm body (4), the whole exhaust process is consistent with the normal exhaust process, and only when the cam rotates to the normal exhaust angle, the driven plunger (14) can push the exhaust valve to open for exhaust.
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| CN201910829155.9A CN110566308B (en) | 2019-09-03 | 2019-09-03 | Reset slide valve type rocker arm mechanism for engine braking and braking method thereof |
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| CN201910829155.9A CN110566308B (en) | 2019-09-03 | 2019-09-03 | Reset slide valve type rocker arm mechanism for engine braking and braking method thereof |
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| CN110566308B true CN110566308B (en) | 2020-08-25 |
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| CN112065525B (en) | 2020-09-09 | 2021-11-19 | 潍柴动力股份有限公司 | Rocker arm mechanism and engine assembly |
| CN112253274B (en) * | 2020-09-11 | 2022-02-18 | 浙江九隆机械有限公司 | Brake rocker arm |
| CN113123843B (en) * | 2021-05-11 | 2022-07-29 | 浙江康和机械科技有限公司 | Braking rocker arm assembly, device thereof and engine |
| CN114033525A (en) * | 2021-12-16 | 2022-02-11 | 浙江康和机械科技有限公司 | Braking rocker arm, braking rocker arm system and vehicle |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| US6253730B1 (en) * | 2000-01-14 | 2001-07-03 | Cummins Engine Company, Inc. | Engine compression braking system with integral rocker lever and reset valve |
| WO2002101212A2 (en) * | 2001-06-13 | 2002-12-19 | Diesel Engine Retarders, Inc. | Latched reset mechanism for engine brake |
| CN101319636B (en) * | 2008-06-03 | 2010-12-08 | 江苏大学 | Integrated valve actuating mechanism used for engine driving and braking condition, and its control method |
| DE112014003482T5 (en) * | 2013-07-29 | 2016-04-07 | Cummins Inc. | Apparatus and method for adjusting the play of engine brakes |
| CN203594476U (en) * | 2013-11-20 | 2014-05-14 | 浙江康和机械科技有限公司 | Integrated rocker arm braking device of engine |
| CN204386688U (en) * | 2014-12-25 | 2015-06-10 | 浙江康和机械科技有限公司 | The integrated rocker arm brake apparatus of mechanically joined motor reset is risen with valve |
| CN104500164B (en) * | 2015-01-03 | 2017-01-11 | 浙江康和机械科技有限公司 | Integrated engine brake rocker arm structure |
| EP3430246B1 (en) * | 2016-03-14 | 2020-01-15 | Volvo Truck Corporation | A device for controlling at least one valve in an internal combustion engine |
| CN108868947B (en) * | 2018-08-06 | 2023-07-25 | 浙江大学 | Reset rocker arm type engine braking device and braking method thereof |
| CN109162785B (en) * | 2018-08-06 | 2023-11-24 | 浙江大学 | Cam-driven engine braking device and braking method thereof |
| CN110173314B (en) * | 2019-05-15 | 2023-07-18 | 浙江大学 | Valve bridge capable of realizing compression release type engine braking and exhaust braking method thereof |
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Effective date of registration: 20220628 Address after: 317600 Taiwan trade processing zone, Damaiyu Development Zone, Yuhuan City, Taizhou City, Zhejiang Province Patentee after: Zhejiang Yutai Seiko Co.,Ltd. Address before: 310058 Yuhang Tang Road, Xihu District, Hangzhou, Zhejiang 866 Patentee before: ZHEJIANG University |