CN210530943U - Compression release type engine cylinder inner brake device with engine oil pressurization function - Google Patents

Abstract

The utility model discloses a compression release formula engine cylinder internal braking device of machine oil pressure boost, include: the camshaft is provided with an oil through cavity along the axial direction and a rotary oil inlet interface device, the rotary oil inlet interface device is communicated with an engine oil supply device, and the engine oil supply device comprises an engine oil pressurization oil way; an exhaust cam of the cam shaft is radially provided with a mounting hole communicated with the oil through cavity, and a sliding plunger mechanism is arranged in the mounting hole; the utility model supplies oil to the oil cavity of the cam shaft through the engine oil pressure increasing oil circuit only when the engine is in the in-cylinder braking mode, and the sliding plunger mechanism extends out of the cam surface of the exhaust cam to form a braking bulge to realize in-cylinder braking; when the engine is in a normal working state, engine oil is decompressed, and the sliding plunger mechanism is recovered in the mounting hole of the exhaust cam; the working time of the sliding plunger mechanism is very short, and the working reliability of the engine is higher.

Description

Compression release type engine cylinder inner brake device with engine oil pressurization function

Technical Field

The utility model relates to the technical field of engines, concretely relates to compression release formula engine cylinder internal braking device of machine oil pressure boost.

Background

In the normal operation process of the engine, the engine completes four working cycles of air intake, compression, work application and exhaust every time the camshaft rotates 360 degrees. At the end of the compression stroke, fuel is injected into the cylinder for combustion, and work is applied to the outside in the subsequent expansion stroke.

The brake in the engine cylinder is a form of auxiliary brake of the whole vehicle, and the brake in the engine cylinder contributes to improving the brake capacity of the whole vehicle and reducing the brake load of the main brake of the whole vehicle. When the engine is braked in the cylinder of the engine, the exhaust valve is opened for a small lift range under the driving of the braking device in the cylinder of the engine when the compression stroke of the engine is close to the top dead center, the compressed high-pressure gas in the cylinder is rapidly released, the pressure in the cylinder is rapidly reduced, and the energy of the power stroke is reduced, so that the engine does not work outwards basically in the next power stroke, the engine is decelerated, and the purpose of braking in the cylinder of the engine is realized.

Chinese utility model patent with publication number CN201241740Y, entitled "a four-stroke internal combustion engine rocker arm integrated form arresting gear" discloses an engine feels jar interior arresting gear, it sets up two braking archs on the exhaust cam for realize opening the intake valve before the intake stroke finishes and increasing the air input, open exhaust valve release pressure before the compression stroke finishes and realize the jar of engine in braking, in order to offset the valve lift that the braking arch arouses when the engine normally operates, need set up hydraulic control's clearance compensation mechanism on the rocker 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.

Disclosure of Invention

In view of this, the technical problem to be solved by the present invention is: an in-cylinder brake device for an engine oil-pressurized compression-release engine is provided to improve the reliability of the operation of the engine.

In order to solve the technical problem, the technical scheme of the utility model is that: an in-cylinder brake device for an oil-pressurized compression-release engine, comprising:

a camshaft provided with a plurality of exhaust cams; the camshaft is provided with an oil through cavity along the axial direction, the camshaft is provided with a rotary oil inlet interface device, the rotary oil inlet interface device is communicated with an engine oil supply device, and the engine oil supply device comprises an engine oil pressurization oil way;

the exhaust cam is provided with a mounting hole along the radial direction, the mounting hole is communicated with the oil through cavity, a sliding plunger mechanism is arranged in the mounting hole, and when oil is supplied to the oil through cavity through the engine oil pressurization oil way, 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, the peripheral surface of the oil inlet shaft neck is provided with an annular oil groove, 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.

And a pressure sensor is arranged in an oil path between the rotary oil inlet interface device and the engine oil supply device.

Wherein, the machine oil pressure boost oil circuit includes: the oil inlet device comprises a first electromagnetic directional valve, a plunger pressure cylinder and a second electromagnetic directional valve which are sequentially connected, wherein the first electromagnetic directional valve is connected with an engine oil path of an engine, and the second electromagnetic directional valve is connected with the rotary oil inlet interface device.

Wherein the plunger pressure cylinder includes: the plunger cylinder body, the cover plate, the small-diameter plunger, the large-diameter plunger and the plunger return spring; the plunger cylinder body is provided with a small-diameter hole and a large-diameter hole which are communicated along the axial direction of the plunger cylinder body, and the cover plate is fixed at the end part of the plunger cylinder body; the small-diameter plunger is slidably mounted in the small-diameter hole, a small oil cavity is enclosed among the small-diameter hole, the small-diameter plunger and the cover plate, and the small oil cavity is connected with the second electromagnetic reversing valve; the large-diameter plunger is slidably mounted in the large-diameter hole, a large oil cavity is defined by the large-diameter hole, the large-diameter plunger and the cover plate, and the large oil cavity is connected with the first electromagnetic reversing valve; the plunger return spring is sleeved on the small-diameter plunger and clamped between the hole bottom of the large-diameter hole and the large-diameter plunger, and a cavity where the plunger return spring is located is free of an oil cavity.

Wherein, the plunger cylinder body is provided with the communicating blow-off hole of oilless chamber.

And a first one-way valve is arranged in an oil way connecting the small oil cavity and the second electromagnetic reversing valve.

The engine oil supply device further comprises an engine oil pressure reducing oil path connected with the engine oil pressurizing oil path in parallel.

The engine oil pressure reducing oil path comprises a pressure reducing valve, and the pressure reducing valve is arranged in an oil path between the second electromagnetic directional valve and the engine oil path of the engine.

Wherein the pressure reducing valve comprises: the pressure regulating valve comprises a valve body, a valve ball, a pressure regulating spring and a pressure regulating screw, wherein an oil inlet and an oil outlet communicated with a valve cavity of the valve body are formed in the valve body, the valve ball is arranged in the valve cavity, the valve ball is blocked at the oil inlet, the pressure regulating screw is in threaded connection with the valve body, one end of the pressure regulating spring is supported at the valve ball, and the other end of the pressure regulating spring is supported at the pressure regulating screw.

The engine oil supply device further comprises a pressure relief oil path, and the pressure relief oil path comprises a camshaft oil cavity pressure relief oil path and a pressure cylinder large oil cavity pressure relief oil path.

The pressure relief oil path of the large oil cavity of the pressure cylinder comprises a first overflow pressure retaining valve, and the first overflow pressure retaining valve is arranged in the oil path between the first electromagnetic directional valve and the oil pan; the camshaft leads to oil chamber pressure release oil circuit and includes second overflow pressure retaining valve, second overflow pressure retaining valve set up in the second electromagnetic directional valve with in the oil circuit between the oil pan.

The engine oil supply device further comprises a small oil cavity oil supplementing oil path of the pressure cylinder.

The oil supplementing oil path of the small oil cavity of the pressure cylinder comprises a second one-way valve, and the second one-way valve is arranged in an oil path between the engine oil path and the small oil cavity.

The first electromagnetic directional valve and the second electromagnetic directional valve are two-position three-way electromagnetic directional valves.

After the technical scheme is adopted, the beneficial effects of the utility model are as follows:

because the utility model discloses a compression release formula engine cylinder internal braking device of machine oil pressure boost, its camshaft has seted up along the axial and leads to the oil pocket, leads to the oil pocket and communicates with machine oil feeding device through rotatory oil feed interface arrangement, and machine oil feeding device includes machine oil pressure boost oil circuit, and the exhaust cam on the camshaft radially has seted up the mounting hole that communicates with logical oil pocket, is provided with the slip plunger mechanism in the mounting hole; when the engine is in a normal working mode, the sliding plunger mechanism does not act; when the engine enters an in-cylinder braking mode, the engine oil pressurization oil path supplies oil to the oil through cavity, the sliding plunger mechanism extends out of the cam surface of the exhaust cam to form a braking bulge, and the valve is pushed to be erected or the valve protective cap is opened to the exhaust valve, so that in-cylinder braking is completed. Compared with the prior art, the sliding plunger mechanism extends out of the cam surface of the exhaust cam under the action of the booster oil only when the engine is in the 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 mechanism is recovered in the mounting hole of the exhaust cam, and the whole exhaust cam is like a common exhaust cam, so that the working reliability of the engine is higher.

Drawings

FIG. 1 is a schematic diagram of an embodiment of an oil pressurized compression release engine in-cylinder brake apparatus 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;

FIG. 6 is a schematic view of the oil supply of FIG. 1;

FIG. 7 is a schematic view of the relief valve arrangement of FIG. 6;

in the figure: i-a valve train; II-engine oil supply device;

10-an exhaust valve; 11-valve spring; 12-valve rocker arm; 13-a rocker shaft; 14-a push rod; 15-a tappet; 20-a camshaft; 21-an intake cam; 22-exhaust cam; 23-oil cavity opening; 24-an annular oil groove; 25-a timing gear; 3-rotating the oil inlet interface device; 31-end cap; 32-fixing the oil sleeve; 321-oil through holes; 40-a pressure sensor; 50-plunger pressurized cylinder; 51-plunger cylinder; 511-air release hole; 52-left end closure; 53-right end cover plate; 54-small diameter plunger; 55-plunger return spring; 56-large diameter plunger; 61-a first electromagnetic directional valve; 62-a second electromagnetic directional valve; 70-a sliding plunger mechanism; 71-a sliding plunger; 711-spring mounting holes; 712-slotted holes; 72-plunger return spring; 73-a pin shaft; 74-plug; 80-a pressure relief valve; 81-a valve body; 811-oil inlet; 812-an oil outlet; 82-a valve ball; 83-pressure regulating spring; 84-pressure regulating screw; 91-a first one-way valve; 92-a second one-way valve; 100-oil pan; 101-a first overflow pressure retention valve; 102-a second overflow pressure retention valve; phi x-macropore; Φ y-pinhole; a-a large oil chamber; b-a small oil chamber; c-no oil cavity; L0-Engine oil circuit; l1-oil pressurization circuit; l2-engine oil pressure relief circuit; l3-camshaft oil cavity pressure relief oil path; l4-big oil chamber pressure relief oil path of pressure cylinder; l5-small oil cavity oil supplementing oil path of pressure cylinder.

Detailed Description

The present invention will be described in further detail with reference to the following drawings and examples.

It is noted that, herein, ordinal terms such as "first," "second," etc., are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; the terms "mounted," "connected," and the like are to be construed broadly and may, for example, be mechanical or electrical connections between elements; the elements may be directly connected or indirectly connected through an intermediate, and a person skilled in the art can understand the specific meaning of the above terms according to specific situations.

The utility model discloses a core lies in, for the supporting machine oil feeding device II of valve train I of engine, provides pressure boost machine oil through machine oil feeding device II, realizes the braking in the engine cylinder.

As shown in fig. 1, in the compression-release engine cylinder braking device with engine oil pressurization according to the embodiment of the present invention, the valve rocker 12 is rotatably mounted on the rocker shaft 13, the push rod 14 and the exhaust valve 10 are respectively disposed at two sides of the rocker shaft 13, when the tappet 15 and the push rod 14 push the valve rocker 12 from one side to swing around the rocker shaft 13 under the action of the exhaust cam 22 of the camshaft 20, the other side of the valve rocker 12 presses the exhaust valve 10, and the valve is opened; when the camshaft rotates a specified angle, the exhaust valve 10 returns under the action of the valve spring 11, 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.

As shown in fig. 1, an oil through cavity 23 is axially formed in the camshaft 20, the camshaft 20 is provided with a rotary oil inlet interface device 3, the rotary oil inlet interface device 3 is communicated with an engine oil supply device II, and the engine oil supply device II is provided with an engine oil pressurization oil circuit. The exhaust cam 22 is provided with a mounting hole along the radial direction, the mounting hole is communicated with the oil through cavity 23, a sliding plunger mechanism 70 is arranged in the mounting hole, and when oil is supplied to the oil through cavity 23 through the engine oil pressurization oil path, the sliding plunger mechanism 70 extends out of the cam surface of the exhaust cam 22 to form a braking bulge.

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 3 is disposed at an opening end of the oil through cavity 23, the rotary oil inlet interface device 3 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, an annular oil groove 24 is disposed on an outer circumferential surface of the oil inlet journal, 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. An end cap 31 is provided at the end of the camshaft 20 for sealing the opening of the oil through chamber 23, and the end cap 31 is also provided with an annular flange for restricting the axial movement of the stationary oil jacket 32.

Wherein, be provided with pressure sensor 40 in the oil circuit between rotatory oil feed interface arrangement 3 and machine oil feed arrangement II for detect feedback oil pressure, as the basis of judging.

As shown in fig. 6, the oil supply device II includes: an engine oil pressurization oil path L1, an engine oil pressure reduction oil path L2, a camshaft oil through cavity pressure relief oil path L3, a pressure cylinder large oil cavity pressure relief oil path L4 and a pressure cylinder small oil cavity oil supplement oil path L5.

As shown in fig. 6, the oil pressure-increasing oil passage L1 includes: the first electromagnetic directional valve 61, the plunger pressure cylinder 50 and the second electromagnetic directional valve 62 are connected in sequence, the first electromagnetic directional valve 61 is connected with an engine oil path L0, and the second electromagnetic directional valve 62 is connected with the rotary oil inlet interface device 3. Preferably, the first electromagnetic directional valve 61 and the second electromagnetic directional valve 62 are two-position three-way electromagnetic directional valves.

Wherein the plunger pressure cylinder 50 includes: plunger cylinder 51, left end apron 52, right end apron 53, minor diameter plunger 54, major diameter plunger 56, plunger return spring 55. The plunger cylinder body 51 is provided with a small-diameter hole and a large-diameter hole which are communicated along the axial direction, the diameter of the large-diameter hole is D, the diameter of the small-diameter hole is D, and the design D > D is adopted, and the two cover plates are fixed at the end part of the plunger cylinder body 51; the small-diameter plunger 54 is slidably mounted in the small-diameter hole, and forms a pair of coupling parts with the small-diameter hole, a small oil cavity B is defined by the small-diameter hole, the small-diameter plunger 54 and the left end cover plate 52, and the small oil cavity B is connected with the second electromagnetic reversing valve 62; big footpath plunger 56 slidable mounting is in big footpath hole, be a pair of idol piece with big footpath hole, enclose into big oil pocket A between big footpath plunger 56 and the right-hand member apron 53 in big footpath hole, big oil pocket A links to each other with first electromagnetic directional valve 61, path plunger 54 is located to big footpath plunger 56's plunger return spring 55 cover, and press from both sides between big footpath hole's hole bottom and big footpath plunger 56, the chamber at plunger return spring 55 place is oil free chamber C, be provided with on the plunger cylinder body 51 with the communicating release hole 511 of oil free chamber C. In order to reduce the difficulty of machining, the large-diameter plunger 56 and the small-diameter plunger 54 are designed as two independent pieces, and a small-diameter plunger return spring may be provided for the small-diameter plunger 54 in the small oil chamber B, which is not shown in detail here. Of course, the large diameter plunger 56 and the small diameter plunger 54 may be designed as one piece if the machining accuracy is required.

Wherein, the oil circuit that the small oil chamber B links with said second electromagnetic directional valve 62 has the first check valve 91 in it, prevent the oil of the oil cavity 23 of the camshaft 20 from flowing backwards into the small oil chamber B.

As shown in fig. 6, the oil pressure-reducing oil passage L2 is connected in parallel to the oil pressure-increasing oil passage L1. The oil relief oil passage includes a relief valve 80, and the relief valve 80 is provided in an oil passage between the second electromagnetic directional valve 62 and the engine oil passage L0.

As shown in fig. 7, in the present embodiment, a pressure reducing valve with a simple structure is designed, and the pressure reducing valve 80 includes: a valve body 81, a valve ball 82, a pressure regulating spring 83 and a pressure regulating screw 84. The valve body 81 is provided with an oil inlet 811 and an oil outlet 812 which are communicated with the valve cavity, the valve ball 82 and the pressure regulating spring 83 are arranged in the valve cavity, the valve ball 82 is blocked at the oil inlet 811, the pressure regulating screw 84 is in threaded connection with the valve body 81, one end of the pressure regulating spring 83 abuts against the valve ball 82, and the other end of the pressure regulating spring 83 abuts against the pressure regulating screw 84. By adjusting the pressure adjusting screw 84, the acting force of the pressure adjusting spring 83 on the valve ball 82 can be adjusted, so that the pressure difference between the oil inlet 811 and the oil outlet 812 can be adjusted.

Obviously, the pressure reducing valve 80 may also be a pressure reducing valve of the prior art.

As shown in fig. 6, the pressure-increasing cylinder large oil chamber pressure-releasing oil path L4 includes a first overflow pressure-maintaining valve 101, and the first overflow pressure-maintaining valve 101 is provided in the oil path between the first electromagnetic directional valve 61 and the oil pan 100. The camshaft oil cavity pressure relief oil passage L3 includes a second overflow pressure retaining valve 102, and the second overflow pressure retaining valve 102 is disposed in an oil passage between the second electromagnetic directional valve 62 and the oil pan 100.

The structure of the overflow pressure retaining valve is the same as that of the pressure reducing valve 80, the pressure of the front end is adjusted through the pressure adjusting spring, and the first overflow pressure retaining valve 101 is used for ensuring that engine oil in the large oil cavity A cannot be emptied when the large oil cavity A is decompressed, so that the lower opening pressure is achieved when the cylinder is braked next time.

As shown in fig. 6, the pressure-increasing cylinder small oil chamber oil-supplementing oil path L5 includes a second check valve 92, and the second check valve 92 is disposed in the oil path between the engine oil path L0 and the small oil chamber B, so that during braking in the oil pressure-increasing cylinder, the engine oil in the engine oil path L0 opens the second check valve 92 and is continuously supplemented into the small oil chamber B.

The working principle of the utility model is as follows:

when the engine normally works, namely the engine is in a non-cylinder braking mode, the first electromagnetic directional valve 61 and the second electromagnetic directional valve 62 are both powered off, the engine oil pressure reducing oil path L2 passes through, the engine oil is communicated with the oil passing chamber 23 of the camshaft 20 through the pressure reducing valve 80 and the second electromagnetic directional valve 62, the thrust generated on the sliding plunger 71 of the sliding plunger mechanism 70 is smaller than the elastic force of the plunger return spring 72, and the sliding plunger 71 is stationary inside the camshaft 20. The pressure sensor 40 detects the camshaft cavity oil pressure, and when the cavity oil pressure is greater than the starting movement oil pressure of the sliding plunger 71 due to a failure or the like, the system issues a failure alarm.

When the engine enters an in-cylinder braking mode, the first electromagnetic directional valve 61 and the second electromagnetic directional valve 62 are both electrified, the engine oil pressurization oil path L1 passes through, the engine oil is communicated with the large oil chamber A, the engine oil acts on one end of the large-diameter plunger 56, the other end of the large-diameter plunger 56 pushes the small-diameter plunger 54 to move, so that the engine oil pressure in the small oil chamber B is greatly increased, the thrust generated on the sliding plunger 71 after the oil pressure of the small oil chamber B is transmitted to the inner cavity of the camshaft is greater than the resultant force of the elastic force of the plunger return spring 72 and the valve spring 11, at this time, the sliding plunger 71 moves, the top of the sliding plunger 71 protrudes out of the cam surface of the exhaust cam 22 of the camshaft 20, the tappet 15 or the valve protective cap is pushed to move upwards, the valve rocker 12 rotates around the rocker.

In the in-cylinder braking process, the pressure sensor 40 detects the oil pressure of the inner cavity of the camshaft, after the large-diameter plunger 56 compresses the plunger return spring 55 to move to the limit position, if the oil pressure fed back by the pressure sensor 40 does not rise or begins to fall any more, the first electromagnetic directional valve 61 is controlled to be powered off (the second electromagnetic directional valve 62 is powered off and keeps the power-on state), the large oil cavity A is connected with the oil pan 100 through the first overflow pressure retaining valve 101, the pressure drops, the large-diameter plunger 56 moves towards the direction far away from the small-diameter plunger 54, after a period of time, the first electromagnetic directional valve 61 is powered on again, and the pressurization process is repeated until the oil pressure of the inner cavity of the camshaft reaches the requirement.

When the in-cylinder braking is required to be finished, the first electromagnetic directional valve 61 and the second electromagnetic directional valve 62 are powered off simultaneously, the camshaft passes through the oil cavity pressure relief oil path L3, the oil pressure in the inner cavity of the camshaft is relieved through the second overflow pressure retaining valve 102, and the sliding plunger 71 returns to the position at the bottom; the pressure relief oil path L4 for the large oil cavity of the pressure increasing cylinder passes through, the pressure in the large oil cavity A is relieved, the large-diameter plunger 56 returns, and the braking process in the cylinder is finished.

Compared with the prior art, the utility model has the advantages that the sliding plunger mechanism only extends out of the cam surface of the exhaust cam under the action of the booster oil when the engine is in the in-cylinder braking mode, and the working time of the sliding plunger mechanism is very short; when the engine is in a normal working state, the engine oil is decompressed, the sliding plunger mechanism is recovered in the mounting hole of the exhaust cam, and the whole exhaust cam is like a common exhaust cam, so that 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.

The foregoing is an example of the preferred embodiment of the present invention, and those parts not described in detail are known to those skilled in the art, and the scope of the present invention is defined by the appended claims, and all equivalent changes that can be made based on the teachings of the present invention are within the scope of the present invention.

Claims (16)

1. An in-cylinder brake device for an oil-pressurized compression-release engine, comprising: a camshaft provided with a plurality of exhaust 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 camshaft is provided with a rotary oil inlet interface device, the rotary oil inlet interface device is communicated with an engine oil supply device, and the engine oil supply device comprises an engine oil pressurization oil way;

the exhaust cam is provided with a mounting hole along the radial direction, the mounting hole is communicated with the oil through cavity, a sliding plunger mechanism is arranged in the mounting hole, and when oil is supplied to the oil through cavity through the engine oil pressurization oil way, the sliding plunger mechanism extends out of the cam surface of the exhaust cam to form a braking bulge.

2. The engine-oil-pressurized compression-release-type engine in-cylinder brake device according to claim 1, wherein the sliding plunger mechanism includes a sliding plunger, a plunger return spring, a pin shaft, and a plug, the mounting hole is a stepped hole including a large hole and a small hole, the small hole radially penetrates a portion of the camshaft on one side of the oil passage chamber and forms a blind hole in a portion of the camshaft on the other side of the oil passage chamber, the large hole is recessed from the oil passage chamber toward an opening direction of the small hole, the pin shaft is installed in the large hole, the sliding plunger is installed in the small hole, the sliding plunger is axially provided with a spring mounting hole and radially provided with a long groove hole, the pin shaft is slidably provided in the long groove hole, the plunger return spring is sandwiched in the spring mounting hole by the pin shaft, when the oil passage chamber is in a pressure-relief 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 engine-pressurized compression-release engine in-cylinder brake apparatus as claimed in claim 1, wherein said rotary oil-intake interface means is provided at an open end of said oil-through chamber; 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, the peripheral surface of the oil inlet shaft neck is provided with an annular oil groove, 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.

4. The engine oil pressurized compression release in-cylinder brake apparatus of claim 1, wherein a pressure sensor is provided in an oil path between the rotary oil feed interface and the oil supply.

5. The oil pressurized compression-release engine in-cylinder brake apparatus according to claim 1, wherein the oil pressurizing oil passage includes: the oil inlet device comprises a first electromagnetic directional valve, a plunger pressure cylinder and a second electromagnetic directional valve which are sequentially connected, wherein the first electromagnetic directional valve is connected with an engine oil path of an engine, and the second electromagnetic directional valve is connected with the rotary oil inlet interface device.

6. The oil pressurized compression release engine in-cylinder brake apparatus as set forth in claim 5, wherein said plunger pressurizing cylinder includes: the plunger cylinder body, the cover plate, the small-diameter plunger, the large-diameter plunger and the plunger return spring; the plunger cylinder body is provided with a small-diameter hole and a large-diameter hole which are communicated along the axial direction of the plunger cylinder body, and the cover plate is fixed at the end part of the plunger cylinder body; the small-diameter plunger is slidably mounted in the small-diameter hole, a small oil cavity is enclosed among the small-diameter hole, the small-diameter plunger and the cover plate, and the small oil cavity is connected with the second electromagnetic reversing valve; the large-diameter plunger is slidably mounted in the large-diameter hole, a large oil cavity is defined by the large-diameter hole, the large-diameter plunger and the cover plate, and the large oil cavity is connected with the first electromagnetic reversing valve; the plunger return spring is sleeved on the small-diameter plunger and clamped between the hole bottom of the large-diameter hole and the large-diameter plunger, and a cavity where the plunger return spring is located is free of an oil cavity.

7. The oil-pressurized compression-release engine in-cylinder brake apparatus according to claim 6, wherein the plunger cylinder is provided with a relief hole communicating with the oil-free chamber.

8. The oil-pressurized compression-release engine in-cylinder brake apparatus according to claim 6, wherein a first check valve is provided in an oil passage connecting the small oil chamber and the second electromagnetic directional valve.

9. The oil-pressurized compression-release engine in-cylinder brake apparatus according to claim 5, wherein said oil supply device further includes an oil pressure-reducing oil passage connected in parallel with said oil pressurizing oil passage.

10. The oil-pressurized compression-release engine in-cylinder brake apparatus according to claim 9, wherein the oil relief oil passage includes a relief valve provided in an oil passage between the second electromagnetic directional valve and the engine oil passage.

11. The oil pressurized compression release engine in-cylinder brake apparatus as set forth in claim 10, wherein said pressure reducing valve includes: the pressure regulating valve comprises a valve body, a valve ball, a pressure regulating spring and a pressure regulating screw, wherein an oil inlet and an oil outlet communicated with a valve cavity of the valve body are formed in the valve body, the valve ball is arranged in the valve cavity, the valve ball is blocked at the oil inlet, the pressure regulating screw is in threaded connection with the valve body, one end of the pressure regulating spring is supported at the valve ball, and the other end of the pressure regulating spring is supported at the pressure regulating screw.

12. The engine oil pressurized compression-release engine in-cylinder brake apparatus according to claim 6, wherein said engine oil supply device further comprises a relief oil passage, said relief oil passage comprising a camshaft oil passage relief oil passage and a booster cylinder large oil passage relief oil passage.

13. The engine-oil-supercharged, compression-release-type engine in-cylinder brake device according to claim 12, wherein said large-oil-chamber pressure-relief oil passage of the supercharging cylinder includes a first overflow pressure-retaining valve provided in an oil passage between said first electromagnetic directional valve and an oil pan; the camshaft leads to oil chamber pressure release oil circuit and includes second overflow pressure retaining valve, second overflow pressure retaining valve set up in the second electromagnetic directional valve with in the oil circuit between the oil pan.

14. The oil-pressurized compression-release engine in-cylinder brake apparatus according to claim 6, wherein said oil supply device further comprises a pressurized-cylinder small-oil-chamber oil-replenishing oil passage.

15. The oil-pressurized compression-release engine in-cylinder brake apparatus according to claim 14, wherein the pressurized-cylinder small-oil-chamber oil-replenishing oil passage includes a second check valve provided in an oil passage between the engine oil passage and the small oil chamber.

16. The oil pressurized compression-release engine in-cylinder brake apparatus according to claim 5, wherein the first electromagnetic directional valve and the second electromagnetic directional valve are two-position three-way electromagnetic directional valves.

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