CN210768970U

CN210768970U - Compression release type in-cylinder brake device for engine

Info

Publication number: CN210768970U
Application number: CN201921769286.4U
Authority: CN
Inventors: 于明卉; 王昊天
Original assignee: Weifang Lichuang Electronic Technology Co Ltd
Current assignee: Weifang Lichuang Electronic Technology Co Ltd
Priority date: 2019-10-21
Filing date: 2019-10-21
Publication date: 2020-06-16
Anticipated expiration: 2029-10-21

Abstract

The utility model discloses a compression release formula engine in-cylinder arresting gear, include: the camshaft is provided with a plurality of exhaust cams and a plurality of intake cams; the camshaft is provided with an oil through cavity along the axial direction, and the camshaft is provided with a rotary oil inlet interface device which is respectively communicated with the high-pressure oil way and the pressure relief oil way through an electromagnetic directional valve; the exhaust cam and the air inlet cam are both provided with mounting holes along the radial direction, the mounting holes are communicated with the oil through cavity, a sliding plunger mechanism is arranged in the mounting holes, and when oil is supplied to the oil through cavity, the sliding plunger mechanism extends out of the cam surface of the exhaust cam to form a braking bulge. Compared with the prior art, the engine has higher working reliability, simultaneously, the air inlet valve and the air outlet valve release the compression pressure of the piston at the same time or close to the same time, the release efficiency is high, the compressed charge in the cylinder released by opening the air inlet valve enters the air inlet pipe of other cylinders, the intake charge of the corresponding cylinder is increased, and the braking power is increased when the compression stroke is performed.

Description

Compression release type in-cylinder brake device for engine

Technical Field

The utility model relates to an in-cylinder brake technical field especially relates to a compression release formula in-cylinder brake equipment.

Background

The in-cylinder braking technology of the engine mainly goes through the development processes of exhaust butterfly valve braking, air-release braking, compression release braking and the like, wherein the compression release braking technology is the best technology of the braking performance of the engine at present, and the basic principle is as follows: when the engine is dragged backwards, the piston compresses the gas in the cylinder to generate braking power in the process of ascending the compression stroke piston. Before the compression top dead center, the compression release type brake device drives the exhaust valve to open a certain opening degree, compressed high-temperature and high-pressure charging in the cylinder is discharged, at the moment, the pressure in the cylinder is rapidly reduced, after a certain crank angle, the exhaust valve is closed again, the piston moves downwards, and as the charging in the cylinder is greatly reduced, the working of the charging in the cylinder on the piston is also greatly reduced, and the counter braking power of the compression charging in the cylinder on the piston is reduced or eliminated.

Compression release braking technology, generally combined with exhaust butterfly valve braking, during the exhaust stroke, the exhaust passage of the engine is closed by the butterfly valve, back pressure is established, and the piston is subjected to the pressure of gas during the upward process, so that the upward speed is reduced, the power loss of the piston is increased, and the braking power is generated again.

Chinese utility model patent CN201241740Y discloses a four-stroke internal combustion engine rocking arm integrated form arresting gear, it sets up two braking archs on the control cam for realize opening the (air) intake valve before the intake stroke finishes and increase the air input, open the cylinder braking that the exhaust valve released pressure realized the engine before the compression stroke finishes, in order to offset the valve lift that the arch arouses of braking when the engine normal operating, need set up hydraulic control's clearance compensation mechanism on the rocking arm. Because the normal operating state accounts for the vast majority of the operating state of the whole engine, the clearance compensation mechanism is in the working state in the vast majority of the operating time of the engine, higher requirements on reliability and the like are provided, and the structure is more complex.

SUMMERY OF THE UTILITY MODEL

The above-mentioned not enough to prior art, the utility model provides a compression release formula engine cylinder internal braking device to improve the reliability of engine work.

In order to solve the technical problem, the utility model discloses a compression release formula engine in-cylinder arresting gear, include: the valve actuating mechanism comprises a camshaft, and the camshaft is provided with a plurality of exhaust cams and a plurality of intake cams; the camshaft is provided with an oil through cavity along the axial direction, the exhaust cam and the intake cam are respectively provided with a mounting hole along the radial direction, the mounting holes are communicated with the oil through cavity, a sliding plunger mechanism is arranged in the mounting holes, the camshaft is provided with a rotary oil inlet interface device, and the rotary oil inlet interface device is respectively communicated with a high-pressure oil path and a pressure relief oil path through an electromagnetic directional valve; when the electromagnetic directional valve is powered off, the oil through cavity is communicated with the pressure relief oil way, and when the electromagnetic directional valve is powered on, the high-pressure oil way is communicated with the oil through cavity and supplies oil to the oil through cavity, so that the sliding plunger mechanism extends out of the cam surface of the exhaust cam to form a braking bulge.

Wherein, the sliding plunger mechanism comprises a sliding plunger, a plunger return spring, a pin shaft and a plug, the mounting hole is a stepped hole, the stepped hole comprises a big hole and a small hole, the small hole radially penetrates through the part of the cam shaft at one side of the oil through cavity and forms a blind hole at the part of the cam shaft at the other side of the oil through cavity, the big hole is sunken from the oil through cavity to the opening direction of the small hole, the pin shaft is mounted in the big hole, the sliding plunger is mounted in the small hole, the sliding plunger is axially provided with a spring mounting hole and radially provided with a slotted hole, the pin shaft is slidably arranged in the slotted hole, the plunger return spring is clamped in the spring mounting hole by the pin shaft, when the oil through cavity is in a pressure relief state, the plunger return spring pushes the sliding plunger against the bottom of the blind hole, the plug is screwed at the outer opening end of the spring mounting hole and seals the spring mounting hole.

The rotary oil inlet interface device is arranged at the opening end part of the oil through cavity.

The rotary oil inlet interface device comprises a fixed oil sleeve, the camshaft is provided with an oil inlet shaft neck, the oil inlet shaft neck is rotatably and hermetically mounted on the fixed oil sleeve, an annular oil groove is formed in the peripheral surface of the oil inlet shaft neck, the annular oil groove is communicated with the oil through cavity, the fixed oil sleeve is provided with an oil through hole, and the oil through hole is communicated with the annular oil groove.

And the end part of the camshaft is provided with an end cover for sealing the opening of the oil through cavity.

The end cover is provided with an annular flange for limiting the axial movement of the fixed oil jacket.

The annular oil groove is not arranged on the outer peripheral surface of the oil inlet shaft neck but arranged on the inner peripheral surface of the fixed oil sleeve.

And the pressure relief oil way is communicated with an oil pan of the engine.

And an overflow valve is arranged in the pressure relief oil way.

And a pressure sensor is arranged in an oil path connecting the oil through hole of the fixed oil sleeve and the electromagnetic directional valve.

Wherein, the electromagnetic directional valve is a two-position three-way electromagnetic directional valve.

After the technical scheme is adopted, the utility model has the advantages that:

1. when the engine is in a normal working mode, the electromagnetic directional valve is powered off, and the sliding plunger mechanism does not act; when the engine enters an in-cylinder braking mode, the electromagnetic directional valve is electrified to control the high-pressure oil path to supply oil to the oil through cavity of the cam shaft, and the sliding plunger of the sliding plunger mechanism extends out of the cam surfaces of the exhaust cam and the intake cam to respectively form braking bulges to push the valve tappet or the valve protective cap to open the exhaust valve and the intake valve so as to complete in-cylinder braking. Compared with the prior art, the sliding plunger extends out of the cam surfaces of the exhaust cam and the intake cam only when the engine is in an in-cylinder braking mode, the working time of the sliding plunger mechanism is very short, and when the engine is in a normal working state, the sliding plunger is recovered in the mounting holes of the exhaust cam and the intake cam, the whole exhaust cam and the whole intake cam are like a common exhaust cam, and therefore the working reliability of the engine is higher. The utility model is suitable for a camshaft underlying engine also is applicable to camshaft overhead engine.

2. Through setting up the phase place of mounting hole on intake cam and the exhaust cam, make intake valve and exhaust valve release the compression pressure of piston simultaneously or near simultaneously, release efficiently, the effect is better.

3. The in-cylinder compressed charge released by the intake valve opening will be admitted to the intake pipe, raising the pressure in the intake pipe. For a multi-cylinder engine, when one cylinder is positioned at the top dead center of a compression stroke, other cylinders can be in an intake stroke intake valve opening state, for example, a six-cylinder engine, when 1 cylinder is positioned at the top dead center of the compression stroke, 3 cylinders and 6 cylinders intake valves are opened, the intake charges of the 3 cylinders and 6 cylinders are increased due to the rise of the pressure in an intake pipe, and the reverse acting force of the charges on pistons is increased when the compression stroke is carried out, namely, the braking power is increased.

Drawings

FIG. 1 is a schematic structural view of an embodiment of an in-cylinder brake apparatus for a compression-release engine of the present invention;

FIG. 2 is an enlarged view of a portion of FIG. 1 at I;

FIG. 3 is a reference view of the embodiment of FIG. 1 showing the operation of the sliding plunger as it extends;

FIG. 4 is a cross-sectional view taken at A-A of FIG. 1;

FIG. 5 is a schematic view of the cam shaft portion of the sliding plunger mechanism of FIG. 2 with the sliding plunger mechanism removed;

in the figure: 10-exhaust valve, 11 a-valve spring, 12 a-valve rocker, 13 a-rocker shaft, 14 a-push rod, 15 a-tappet, 15 b-tappet, 20-camshaft, 21-intake cam, 22-exhaust cam, 23-oil through cavity, 24-annular oil groove, 25-timing gear, 31-end cover, 32-fixed oil sleeve, 321-oil through hole, 40-pressure sensor, 50-overflow valve, 60-oil pan, 70-sliding plunger mechanism, 71-sliding plunger, 711-spring mounting hole, 712-slotted hole, 72-plunger return spring, 73-pin shaft, 74-plug wire, 80-electromagnetic directional valve, phi x-phi large hole and y-small hole.

Detailed Description

The present invention will be further explained with reference to the drawings and examples.

As shown in FIG. 1, in a compression-release type engine in-cylinder brake device, a valve rocker arm 12a is rotatably mounted on a rocker shaft 13a, a push rod 14a and an exhaust valve 10a are respectively arranged at two sides of the rocker shaft 13a, when a tappet 15a and the push rod 14a push the valve rocker arm 12a from one side to swing around the rocker shaft 13a under the action of an exhaust cam 22 of a camshaft 20, the other side of the valve rocker arm 12a presses the exhaust valve 10a, and the valve is opened; when the camshaft rotates by a specified angle, the exhaust valve 10a is returned by the valve spring 11a, and the valve is closed. Camshaft 20 is held in synchronization with the engine crankshaft by timing gear 25.

The above structure is a part of the engine valve train for controlling the motion of the exhaust valve, and the camshaft 20 is further provided with a plurality of intake cams 21 for controlling the opening and closing motions of the corresponding intake valves, only the tappet 15b is shown in fig. 1, and the structures of the intake valves and the like are not shown.

As shown in fig. 1, an oil through cavity 23 is axially formed in the camshaft 20, a mounting hole is radially formed in the exhaust cam 22, the mounting hole is communicated with the oil through cavity 23, a sliding plunger mechanism 70 is arranged in the mounting hole, and a rotary oil inlet interface device is arranged on the camshaft 20 and is respectively communicated with the high-pressure oil path and the pressure relief oil path through an electromagnetic directional valve 80. When the electromagnetic directional valve 80 is powered off, the oil through cavity 23 is communicated with the pressure relief oil path, and when the electromagnetic directional valve 80 is powered on, the high-pressure oil path is communicated with the oil through cavity 23 and supplies oil to the oil through cavity 23, so that the sliding plunger mechanism 70 extends out of the cam surface of the exhaust cam 22 to form a braking bulge.

The pressure relief oil path is communicated with an oil pan 60 of the engine, and an overflow valve 50 is arranged in the pressure relief oil path.

Preferably, the electromagnetic directional valve 80 is a two-position three-way electromagnetic directional valve.

The intake cam 21 is also provided with a mounting hole along the radial direction, and a sliding plunger mechanism 70 is also arranged in the mounting hole.

As shown in fig. 2, 3, 4 and 5, the sliding plunger mechanism 70 includes a sliding plunger 71, a plunger return spring 72, a pin 73 and a plug 74, the mounting hole is a stepped hole, the stepped hole includes a large hole Φ x and a small hole Φ y, the small hole Φ y radially penetrates through the portion of the camshaft on one side of the oil chamber 23 and forms a blind hole on the portion of the camshaft on the other side of the oil chamber 23, the large hole Φ x is recessed from the opening direction of the oil chamber 23 to the small hole Φ y, the pin 73 is mounted in the large hole Φ x, the sliding plunger 71 is mounted in the small hole Φ y, the sliding plunger 71 is axially provided with a spring mounting hole 711 and radially provided with a long slot 712, the pin 73 is slidably disposed in the long slot 712, the plunger return spring 72 is clamped in the spring mounting hole by the pin 73, when the oil chamber 23 is in a pressure relief state, the plunger return spring 72 pushes the sliding plunger 71 against the bottom of the blind hole 711, the plug 74 is screwed to the outer opening end of the spring mounting hole 711 and seals the spring mounting hole 711.

During assembly, the sliding plunger 71 is firstly installed from the small hole phi y, the plunger return spring 72 is installed into the spring installation hole 711, the plunger return spring 72 is compressed, the pin shaft 73 is installed in place from the oil through cavity 23, then the plunger return spring 72 is loosened, the pin shaft 73 is clamped into the large hole phi x, and finally the screw plug 74 is screwed to seal the spring installation hole 711.

As shown in fig. 1, the rotary oil inlet interface device is arranged at the opening end of the oil through cavity 23, the rotary oil inlet interface device includes a fixed oil sleeve 32 and an end cover 31, the camshaft 20 is provided with an oil inlet journal, the oil inlet journal is rotatably and hermetically mounted on the fixed oil sleeve 32, the outer circumferential surface of the oil inlet journal is provided with an annular oil groove 24, the annular oil groove 24 is communicated with the oil through cavity 23, the fixed oil sleeve 32 is provided with an oil through hole 321, and the oil through hole 321 is communicated with the annular oil groove 24. The end cover 31 is provided at the end of the camshaft 20 for sealing the opening of the oil passage chamber 23, and the end cover 31 is further provided with an annular flange for restricting the axial movement of the stationary oil jacket 32.

The utility model discloses a theory of operation is:

as shown in fig. 2, when the engine normally operates, the electromagnetic directional valve 80 is de-energized, and the oil passage chamber 23 of the camshaft 20 communicates with the oil pan 60 through the electromagnetic directional valve 80 and the relief valve 50 to be relieved. The sliding plunger 71 sinks at the bottom of the blind hole under the action of the plunger return spring 72, and the exhaust valve 10a is normally opened and closed.

As shown in fig. 3, when the engine enters the in-cylinder braking mode, the electromagnetic directional valve 80 is controlled to be energized, the oil-through cavity 23 of the camshaft 20 is filled with high-pressure hydraulic oil, the sliding plunger 71 moves upwards under the action of the hydraulic oil, the top end of the sliding plunger protrudes out of the cam surface of the exhaust cam 22 to form a braking protrusion, and the

valve lifters

15a and 15b or a valve cap (camshaft overhead structure) are pushed to open the exhaust valve 10a and the intake valve near the top dead center of the compression stroke of the engine to complete one cycle of in-cylinder braking, and at this time, the pin shaft 73 is attached to the lower bottom surface of the slotted hole 712 of the.

The utility model discloses in, be provided with pressure sensor 40 in the oil circuit that the logical oilhole 321 of fixed oil jacket 32 and solenoid directional valve 80 are connected, pressure sensor 40 is used for detecting the pressure of hydraulic oil, and the feedback is as the foundation of judging.

In the present invention, the annular oil groove 24 may not be provided on the outer peripheral surface of the oil inlet journal but on the inner peripheral surface of the fixed oil jacket 32. When the camshaft 20 rotates, the annular oil groove 24 can communicate the hydraulic oil from the high-pressure oil passage with the oil communication chamber 23.

The utility model discloses in, the hydraulic oil in the high-pressure oil circuit can drive the hydraulic pump through the engine and produce, also can adopt other booster mechanisms to realize.

The present invention is not limited to the above embodiments, and all improvements based on the concept, principle, structure and method of the present invention will fall within the protection scope of the present invention.

Claims

1. A compression-release in-cylinder brake apparatus for an engine, comprising:

the valve actuating mechanism comprises a camshaft, and the camshaft is provided with a plurality of exhaust cams and a plurality of intake cams; it is characterized in that the preparation method is characterized in that,

the camshaft is provided with an oil through cavity along the axial direction, the exhaust cam and the intake cam are respectively provided with a mounting hole along the radial direction, the mounting holes are communicated with the oil through cavity, a sliding plunger mechanism is arranged in the mounting holes, the camshaft is provided with a rotary oil inlet interface device, and the rotary oil inlet interface device is respectively communicated with a high-pressure oil path and a pressure relief oil path through an electromagnetic directional valve; when the electromagnetic directional valve is powered off, the oil through cavity is communicated with the pressure relief oil way, and when the electromagnetic directional valve is powered on, the high-pressure oil way is communicated with the oil through cavity and supplies oil to the oil through cavity, so that the sliding plunger mechanism extends out of the cam surface of the exhaust cam to form a braking bulge.

2. The compression-release engine in-cylinder brake apparatus as defined in claim 1, wherein said sliding plunger mechanism includes a sliding plunger, a plunger return spring, a pin and a plug, said mounting hole is a stepped hole, said stepped hole includes a large hole and a small hole, said small hole radially penetrates a portion of said camshaft on one side of said oil passage chamber and forms a blind hole in a portion of said camshaft on the other side of said oil passage chamber, said large hole is recessed from said oil passage chamber toward an opening direction of said small hole, said pin is mounted in said large hole, said sliding plunger is mounted in said small hole, said sliding plunger is axially provided with a spring mounting hole and radially provided with a long groove hole, said pin is slidably provided in said long groove hole, said plunger return spring is sandwiched in said spring mounting hole by said pin, when said oil passage chamber is in a pressure-released state, the plunger return spring enables the sliding plunger to abut against the bottom of the blind hole, and the plug is screwed at the outer opening end of the spring mounting hole and seals the spring mounting hole.

3. The compression-release engine in-cylinder brake apparatus as defined in claim 1, wherein said rotary oil-intake interface means is provided at an open end of said oil-through chamber.

4. The compression-release engine in-cylinder brake apparatus as defined in claim 1, wherein said rotary oil inlet interface means includes a fixed oil jacket, said camshaft is provided with an oil inlet journal, said oil inlet journal is rotatably and sealingly mounted to said fixed oil jacket, an annular oil groove is formed in an outer circumferential surface of said oil inlet journal, said annular oil groove is communicated with said oil through cavity, said fixed oil jacket is formed with an oil through hole, and said oil through hole is communicated with said annular oil groove.

5. The compression-release engine in-cylinder brake apparatus as defined in claim 4, wherein an end of said camshaft is provided with an end cap sealing an opening of said oil passage chamber.

6. The compression-release engine in-cylinder brake apparatus as defined in claim 5, wherein said end cap provides an annular flange for limiting axial movement of said stationary oil jacket.

7. The compression-release engine in-cylinder brake apparatus as defined in claim 4, wherein the annular oil groove is provided not on an outer peripheral surface of the oil inlet journal but on an inner peripheral surface of the fixed oil jacket.

8. The compression-release engine in-cylinder brake apparatus according to claim 1, wherein the pressure-relief oil passage communicates with an oil pan of the engine.

9. The compression-release engine in-cylinder brake apparatus according to claim 1, wherein a relief valve is provided in the relief oil passage.

10. The in-cylinder brake apparatus for a compression-release engine according to claim 4, wherein a pressure sensor is provided in an oil passage connecting the oil passage hole of the fixed oil jacket and the electromagnetic directional valve.

11. The compression-release engine in-cylinder brake apparatus as defined in claim 1, wherein said electromagnetic directional valve is a two-position three-way electromagnetic directional valve.