CN210919173U - Compression release type in-cylinder brake device for engine - Google Patents

Abstract

The utility model discloses a compression release type engine cylinder inner brake device, a camshaft is provided with a camshaft axial channel extending along the axial direction, an exhaust cam is provided with an exhaust cam radial hole communicated with the camshaft axial channel along the radial direction, a brake mechanism is arranged in the camshaft corresponding to each exhaust cam, the brake mechanism comprises a sliding plunger and a control shaft which are connected, the sliding plunger is slidably arranged in the exhaust cam radial hole, and the control shaft is slidably arranged in the camshaft axial channel; when braking is carried out in the cylinder, the braking mechanism is controlled by the driving mechanism, the control shaft slides along the axial channel of the cam shaft and drives the sliding plunger to slide along the radial hole of the exhaust cam, so that the sliding plunger extends out of the cam surface of the exhaust cam to form a braking bulge, and even if the sliding plunger is subjected to the downward pressing force of the tappet, the sliding plunger cannot sink due to the bearing of the control shaft, the braking is reliable, and the braking effect is good; when the brake is not in the cylinder, the brake mechanism is controlled by the reset mechanism, and the sliding plunger retracts into the radial hole of the exhaust cam.

Description

Compression release type in-cylinder brake device for engine

Technical Field

The utility model relates to the technical field of engines, concretely relates to arresting gear in compression release formula engine cylinder.

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 cylinder is braked, the compression stroke engine applies auxiliary work to the outside, when the compression stroke is close to the top dead center, the exhaust valve is opened by a small lift range under the driving of the braking device in the engine cylinder, 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 apply work to the outside basically in the next power stroke, the engine is decelerated, and the purpose of braking in the engine cylinder is achieved.

Chinese utility model patent with publication number CN201241740Y, entitled "a four-stroke internal combustion engine rocker arm integrated form arresting gear" discloses an engine in-cylinder 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 in-cylinder braking of engine, 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.

To this end, the applicant developed a new type of in-cylinder engine braking device and has already filed a patent application with application number 201911000047.7 entitled "compression-release in-cylinder engine braking device", but in subsequent practical applications, the applicant found that the following problems exist, which are to be further improved:

when the brake state is in the cylinder, the reverse thrust of the sliding plunger on hydraulic oil is large, so that the pressure of the hydraulic oil is high instantly, impact is caused on a sealing element and the like, and the sealing reliability is influenced; under the condition of high hydraulic pressure, the condition that hydraulic oil is not compressible is not established, so that the sliding plunger is caused to sink in a proper amount under the action of the tappet, and the braking effect is influenced.

Disclosure of Invention

In view of this, the technical problem to be solved by the present invention is: provided is a compression-release in-cylinder brake device for an engine, which is reliable in braking.

In order to solve the technical problem, the technical scheme of the utility model is that: a compression-release engine in-cylinder brake apparatus, comprising: a camshaft provided with a plurality of exhaust cams;

the exhaust cam is provided with an exhaust cam radial hole along the radial direction, and the exhaust cam radial hole is communicated with the camshaft axial channel;

the inner part of the camshaft is provided with a braking mechanism corresponding to each exhaust cam, the braking mechanism comprises a sliding plunger and a control shaft which are connected, the sliding plunger is slidably arranged in a radial hole of the exhaust cam, and the control shaft is slidably arranged in an axial channel of the camshaft;

when braking is carried out in the cylinder, the braking mechanism is controlled by a driving mechanism, the control shaft slides along the axial channel of the camshaft and drives the sliding plunger to slide along the radial hole of the exhaust cam, so that the sliding plunger extends out of the cam surface of the exhaust cam to form a braking bulge; when the brake is not in the cylinder, the brake mechanism is controlled by a reset mechanism, and the sliding plunger retracts into the radial hole of the exhaust cam.

The sliding plunger comprises a plunger body, a plunger inclined through hole is formed in the plunger body and located in the camshaft axial channel, and the plunger inclined through hole is inclined relative to the camshaft axial channel.

The outer end face of the plunger body is an outward-convex curved surface, one end of the plunger body, which is located in the axial channel of the camshaft, is provided with a plunger pressure relief hole, and the plunger pressure relief hole is communicated with the plunger inclined through hole.

The control shaft comprises a control shaft horizontal section and a control shaft inclined section which are connected, the control shaft horizontal section is matched with the cross section of the axial channel of the camshaft in shape, and the control shaft horizontal section is in sliding fit with the axial channel of the camshaft; the control shaft inclined section is mounted in the plunger inclined through hole in a constrained mode and penetrates out of the plunger inclined through hole, the control shaft inclined section is matched with the cross section shape of the plunger inclined through hole, and the control shaft inclined section is in sliding fit with the plunger inclined through hole; the included angle between the control shaft inclined section and the control shaft horizontal section is an inclined angle, and the inclined angle is not larger than the self-locking angle of the control shaft.

The outer peripheral surface of one end, far away from the horizontal section of the control shaft, of the inclined section of the control shaft is provided with a support arc surface, the support arc surface is supported on the axial channel of the camshaft, and the support arc surface is matched with the arc surface of the axial channel of the camshaft.

And the end part of the horizontal section of the control shaft is provided with an assembling threaded hole.

The control shaft is an integrated component, and the horizontal section of the control shaft is directly connected with the inclined section of the control shaft.

The control shaft can also be a split component, the horizontal section of the control shaft is connected with the inclined section of the control shaft through a pin shaft, two opposite connecting parts are arranged on the end face of the horizontal section of the control shaft, an end part through hole is formed in the end part of the inclined section of the control shaft, and the pin shaft penetrates through the end part through hole and is installed on the connecting parts.

And an ejector rod is arranged between the adjacent control shafts in the axial channel of the camshaft, and the end part of the ejector rod is abutted against the end part of the control shaft.

The first end of camshaft axial passageway is the blind end, canceling release mechanical system set up in the first end of camshaft axial passageway, canceling release mechanical system includes reset spring and spacing seat, one side of spacing seat supports and leans on reset spring, the opposite side of spacing seat supports and leans on the control shaft.

The camshaft is provided with a camshaft pressure relief hole, the camshaft pressure relief hole is communicated with the camshaft axial channel, and the camshaft pressure relief hole is arranged close to the end part of the camshaft and is positioned on the wall of the camshaft between the limiting seat and the exhaust cam.

The axial channel of the camshaft is provided with a hydraulic cavity, the driving mechanism is a hydraulic driving mechanism, and the hydraulic driving mechanism is communicated with the hydraulic cavity through a rotary oil inlet interface device;

the hydraulic driving mechanism comprises an electromagnetic directional valve, a pressure relief oil way and a one-way oil way, wherein the one-way oil way is provided with a one-way valve, the pressure relief oil way is provided with an overflow pressure retaining valve, and the pressure relief oil way is provided with a pressure relief valve; when the electromagnetic directional valve is powered off, the hydraulic cavity is communicated with an oil pan through the pressure relief oil way and is communicated with an engine oil way through the pressure relief oil way; when the electromagnetic directional valve is electrified, the engine oil circuit supplies oil to the hydraulic cavity through the one-way oil circuit, and the sliding plunger extends out of the cam surface of the exhaust cam to form a braking bulge.

The rotary oil inlet interface device comprises a fixed oil sleeve, a fixed oil sleeve and a rotary oil inlet interface device, wherein the fixed oil sleeve is provided with an oil through hole, the oil through hole is connected with the hydraulic driving mechanism, the camshaft is provided with an oil inlet journal, the oil inlet journal is rotatably and hermetically mounted on the fixed oil sleeve, the peripheral surface of the oil inlet journal is provided with an annular oil groove, the annular oil groove is communicated with the hydraulic cavity, and the oil through hole is communicated with the annular oil groove; the end of the camshaft is provided with a plug sealing the opening of the axial passage of the camshaft, the space between the plug and the control shaft forming the hydraulic chamber.

The hydraulic chamber may be arranged to correspond to the mounting journal of the camshaft, a space between two adjacent control shafts forms the hydraulic chamber, the second end of the axial passage of the camshaft is blocked, the rotary oil inlet interface device is arranged at the mounting journal of the camshaft, and the rotary oil inlet interface device includes: the camshaft seat is internally provided with a bearing bush, the mounting shaft neck is rotatably and hermetically mounted on the bearing bush, the peripheral surface of the mounting shaft neck is provided with an annular oil groove, the annular oil groove is communicated with the hydraulic cavity, the camshaft seat and the bearing bush are provided with oil through holes communicated with the annular oil groove, and the oil through holes are connected with the hydraulic driving mechanism; the first end and the second end of the axial channel of the camshaft are respectively provided with the resetting mechanism.

The driving mechanism can also be a linear driving mechanism, the linear driving mechanism is arranged close to the second end of the axial channel of the camshaft, and when the cylinder is braked, the linear driving mechanism pushes the control shaft close to the second end of the axial channel of the camshaft, so that the sliding plunger extends out of the cam surface of the exhaust cam to form a braking bulge.

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

because the camshaft of the compression-release type engine cylinder inner braking device of the utility model is provided with the camshaft axial channel extending along the axial direction, the exhaust cam is provided with the exhaust cam radial hole communicated with the camshaft axial channel along the radial direction, the braking mechanism is arranged inside the camshaft corresponding to each exhaust cam, the braking mechanism comprises the sliding plunger and the control shaft which are connected, the sliding plunger is slidably arranged in the exhaust cam radial hole, and the control shaft is slidably arranged in the camshaft axial channel; when all the sliding plungers are not contacted with the tappet, the driving mechanism drives the control shaft to slide along the axial channel of the camshaft and drives the sliding plungers to slide along the radial holes of the exhaust cam, so that the sliding plungers extend out of the cam surface of the exhaust cam to form braking protrusions, and the in-cylinder braking is realized.

After the control shaft pushes the sliding plunger to extend out of the cam surface of the exhaust cam to form a braking bulge, even if the sliding plunger is pressed downwards by the tappet, because of the bearing of the control shaft and the self-locking action of the inclined surface, the component force generated by the force applied by the sliding plunger to the control shaft along the axial direction of the control shaft is not larger than the friction force applied to the control shaft, the control shaft cannot axially move, and the sliding plunger cannot sink, so that the braking is reliable and the braking effect is good; when the brake is not carried out in the cylinder, the control shaft is pushed under the action of the reset mechanism to drive the sliding plunger to reversely slide along the axial channel of the camshaft to retract into the radial hole of the exhaust cam in the reverse sliding process, so that the normal operation of the engine is not hindered.

The plunger body of the sliding plunger is provided with a plunger inclined through hole inclined relative to the axial channel of the camshaft, the control shaft comprises a control shaft horizontal section and a control shaft inclined section which are connected, the control shaft horizontal section is matched with the cross section shape of the axial channel of the camshaft and is in sliding fit with the cam shaft, the control shaft inclined section is restricted to be installed in the plunger inclined through hole and penetrates out of the plunger inclined through hole, and the control shaft inclined section is matched with the cross section shape of the plunger inclined through hole and is in sliding fit with the plunger inclined through hole; the inclination angle of the plunger inclined through hole is equal to that of the inclined section of the control shaft, and since the inclination angle is small and not larger than the self-locking angle thereof, even if the tappet applies a larger force to the sliding plunger, the control shaft does not move.

The inclined plane pushing mode is adopted between the sliding plunger piston and the control shaft inclined section, in addition, the support cambered surface of the control shaft inclined section is supported in the axial channel of the camshaft, the powerful pushing and supporting effect is achieved on the sliding plunger piston, the sliding plunger piston extends out of the cam surface of the exhaust cam to form a braking bulge, and then the pushing of the tappet is resisted, so that the braking in the cylinder is more reliable.

Drawings

Fig. 1 is a schematic cross-sectional view of a first compression-release engine in-cylinder brake device according to an embodiment of the present invention;

fig. 2 is a schematic cross-sectional view of a compression-release engine in-cylinder brake device according to a second embodiment of the present invention;

fig. 3 is a schematic cross-sectional view of a compression-release engine in-cylinder brake device according to a third embodiment of the present invention;

FIG. 4 is a schematic view of the single cylinder condition of FIG. 1 near the end of the camshaft during in-cylinder braking;

FIG. 5 is a schematic cross-sectional view B-B of FIG. 4;

FIG. 6 is a schematic view of the single cylinder condition of FIG. 1 near the end of the camshaft during non-in-cylinder braking; (ii) a

FIG. 7 is a schematic cross-sectional view of C-C of FIG. 6;

FIG. 8 is a front view of a control shaft of the integrated component of FIG. 1;

FIG. 9 is a left side view of FIG. 8;

FIG. 10 is a perspective view of FIG. 8;

FIG. 11 is an axial cross-sectional view of FIG. 8;

FIG. 12 is an axial cross-sectional view of the control shaft of the split member;

FIG. 13 is a left side view of FIG. 12;

FIG. 14 is a front view of the sliding plunger of FIG. 1;

fig. 15 is a sectional view of fig. 14 in the axial direction thereof;

FIG. 16 is a perspective view of FIG. 14;

fig. 17 is a sectional view of fig. 16 in the axial direction thereof;

in the figure: i-a valve train; II, a hydraulic driving mechanism; III-a linear drive mechanism;

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-camshaft axial passage; 24-an annular oil groove; 25-camshaft relief vent; 26-mounting a journal; 261-annular oil groove; 30-a rotary oil inlet interface device; 31-clogging; 32-fixing the oil sleeve; 321-oil through holes; 40-a reset mechanism; 41-a return spring; 42-a limiting seat; 50-an overflow pressure retaining valve; 60-an oil pan; 70-a braking mechanism; 71-a control shaft; 711-control shaft horizontal section; 7111-assembling threaded holes; 7112-a connecting portion; 712-control axis inclination section; 7121-supporting arc surface; 713-pin shaft; 72-a sliding plunger; 721-plunger inclined through hole; 722-plunger relief hole; 723-curved surface; 73-a mandril; 80-a solenoid directional valve; 90-rotating oil inlet interface device; 91-camshaft seat; 911-oil through hole; 92-bearing bush; 93-end caps; 94-sealing ring; 100-a one-way valve; 200-a pressure reducing valve; a-a hydraulic chamber; b-a hydraulic chamber;

in the figure, the circular arc arrow indicates the camshaft rotation direction, and the double arrow indicates the control shaft movement direction.

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, sets up arrestment mechanism for the valve actuating mechanism I's of engine camshaft, for the supporting actuating mechanism of arrestment mechanism, realizes the braking in the engine cylinder reliably.

Example one

As shown in fig. 1, in the compression-release engine cylinder brake device 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 on both 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 opens; 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. The camshaft 20 is held in synchronization with the engine crankshaft by timing gears.

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, the camshaft 20 is provided with a camshaft axial passage 23 extending along the axial direction thereof, the exhaust cam 22 is provided with an exhaust cam radial hole along the radial direction thereof, and the exhaust cam radial hole is communicated with the camshaft axial passage 23; a brake mechanism 70 is arranged in the camshaft 20 corresponding to each exhaust cam 22, the brake mechanism 70 comprises a control shaft 71 and a sliding plunger 72 which are connected, the sliding plunger 72 is slidably arranged in the radial hole of the exhaust cam, and the control shaft 71 is slidably arranged in the axial channel 23 of the camshaft; when braking in the cylinder, the braking mechanism 70 is controlled by a driving mechanism (in this embodiment, the driving mechanism specifically adopts a hydraulic driving mechanism II), the control shaft 71 slides along the axial channel 23 of the camshaft and drives the sliding plunger 72 to slide along the radial hole of the exhaust cam, so that the sliding plunger 72 extends out of the cam surface of the exhaust cam 22 to form a braking protrusion; when the brake mechanism 70 is controlled by the reset mechanism 40 during non-cylinder braking, the sliding plunger 72 retracts into the exhaust cam radial hole, and the engine operates normally.

As shown in fig. 14 to 17 and fig. 1, the sliding plunger 72 includes a plunger body, the plunger body defines a plunger inclined through hole 721, the plunger inclined through hole 721 is located in the camshaft axial passage 23, the plunger inclined through hole 721 is inclined with respect to the camshaft axial passage 23, and the plunger inclined through hole 721 is a long hole extending along the axial direction of the plunger body. The outer end face of the plunger body is optimally designed to be an outward convex curved surface 723, and when the brake is performed in the cylinder, the curved surface 723 is in line contact with the tappet 15 instead of in surface contact, so that the service life can be prolonged. Further, one end of the plunger body located in the axial passage 23 of the camshaft is provided with a plunger pressure relief hole 722, the plunger pressure relief hole 722 is communicated with the plunger inclined through hole 721, and oil or gas in a bottom cavity of the radial hole of the exhaust cam (when the braking mechanism 70 is driven by a linear driving mechanism III described below, gas in the bottom cavity of the radial hole of the exhaust cam) can be released through the plunger pressure relief hole 722, so that smooth movement of the sliding plunger 72 is ensured.

As shown in fig. 8-11 and fig. 1, the control shaft 71 is a one-piece member, and includes a control shaft horizontal section 711 and a control shaft inclined section 712, which are directly connected, wherein the control shaft inclined section 712 has an inclination such that the control shaft 71 is self-locked when the sliding plunger 72 is pushed by the tappet 15, wherein the control shaft horizontal section 711 is adapted to the cross-sectional shape of the camshaft axial passage 23 (for example, the diameter of the camshaft axial passage 23 is 2R, the diameter of the control shaft horizontal section 711 is also 2R), the control shaft horizontal section 711 is slidably fitted to the camshaft axial passage 23, wherein the control shaft inclined section 712 is constrained to be mounted to the plunger inclined through hole 721 and passes through the plunger inclined through hole 721, the control shaft inclined section 712 is adapted to the cross-sectional shape of the plunger inclined through hole 721 (for example, as shown in fig. 14 and 15, the length of the plunger inclined through hole 721 is a, the width is b, the inclination is α, the control shaft inclined section 712 has an inclination of α, the width is further adapted to the axial supporting arc face of the camshaft inclined section 7123, the control shaft inclined section 712 is mounted to the axial supporting arc face of the camshaft inclined section 7121, and the axial supporting arc face of the camshaft inclined section 7123 is mounted to the camshaft inclined section 7123, and the axial supporting arc face of the camshaft inclined section 7121 is further provided in the axial supporting arc face of the camshaft supporting section 7123 (for supporting axial supporting arc face 7121).

From mechanics principles, the self-locking condition of the control shaft 71 is that the force along the axis received by the control shaft 71 is not more than the maximum friction force, the control shaft 71 satisfies the self-locking condition, and is only related to the friction coefficient (defined as f1) between the sliding plunger 72 and the control shaft 71, the friction coefficient (defined as f2) between the control shaft 71 and the camshaft axial passage 23, and the inclination angle of the inclined section of the control shaft, regardless of the pressure of the tappet 15 against the sliding plunger 72, when the material, surface quality, heat treatment conditions, working conditions (lubrication, etc.) of the parts are determined, the magnitudes of f1 and f2 can be determined, and as long as the designed inclination angle is smaller than the self-locking angle (which can be obtained according to mechanical analysis and is not described herein), the control shaft 71 will not move axially no matter how much force is applied to the sliding plunger 72 by the tappet 15 (without considering other factors such as spring force and hydraulic force).

As shown together in fig. 12 and 13, for the convenience of manufacture, the control shaft 71 may be designed as a split component, and the horizontal section 711 and the inclined section 712 of the control shaft are connected by a pin 713. Two opposite connecting portions 7112 are provided at both sides of the end surface of the control shaft horizontal section 711, an end portion through hole is provided at the end portion of the control shaft inclined section 712, and the pin 713 passes through the end portion through hole and is mounted to the connecting portions 7112. The end face of the inclined control shaft section 712 is in contact with the end face of the horizontal control shaft section 711, so that the brake mechanism 70 is a single unit that is not movable relative to each other. When the brake is in the cylinder, the inclined section 712 of the control shaft bears the downward acting force and transmits the force to the supporting arc face 7121 and the pin 713 to bear together; when the in-cylinder braking state is finished, the control shaft inclined section 712 bears upward acting force, and the acting force is transmitted to the control shaft horizontal section 711 through the pin 713 and the joint end face to be borne.

As shown in fig. 1, a push rod 73 is further disposed between adjacent control shafts 71 in the camshaft axial passage 23, and an end of the push rod 73 abuts against an end of the control shaft 71. The push rod 73 can transmit force to the adjacent control shaft 71 on one hand; on the other hand, by adjusting the length of the push rod 73, the distance by which each cylinder slide plunger 72 protrudes out of the exhaust cam 22 can be adjusted, and the uniformity of the height by which each cylinder slide plunger 72 protrudes out of the exhaust cam 22 is ensured. The longer the length of the push rod 73 is, the shorter the sliding distance of the control shaft 71 is, and the smaller the projecting distance of the sliding plunger 72 is; conversely, the shorter the length of the plunger 73, the longer the sliding distance of the control shaft 71, and the larger the projecting distance of the sliding plunger 72.

As shown in fig. 1, wherein the first end of the camshaft axial passage 23 is a closed end, the reset mechanism 40 is disposed at the first end of the camshaft axial passage 23, the reset mechanism 40 includes a reset spring 41 and a limit seat 42, one side of the limit seat 42 abuts against the reset spring 41, and the other side of the limit seat 42 abuts against the control shaft 71. The limit seat 42 can limit the limit position of the control shaft 71 moving towards the first end of the camshaft axial passage 23; further, by adjusting the length of the stopper seat 42, the height of the sliding plunger 72 protruding from the exhaust cam 22, which is close to the cylinder of the return mechanism 40, can be controlled. The longer the limit seat 42 is, the shorter the sliding distance of the control shaft 71 close to the reset mechanism 40 is, and the smaller the projecting distance of the sliding plunger 72 connected with the control shaft 71 is; conversely, the shorter the stopper seat 42 is, the longer the sliding distance of the control shaft 71 close to the reset mechanism 40 is, and the larger the projecting distance of the sliding plunger 72 connected to the control shaft 71 is.

As shown in fig. 1, the camshaft 20 is further provided with a camshaft relief hole 25, the camshaft relief hole 25 is communicated with the camshaft axial passage 23, and the camshaft relief hole 25 is disposed near the end of the camshaft 20 and is located on the camshaft wall between the limiting seat 42 and the exhaust cam 22. Since the volume of the chamber between the brake mechanism 70 adjacent to the reset mechanism 40 and the reset mechanism 40 is changed during the movement of the control shaft 71, the pressure of the chamber can be released through the camshaft relief hole 25, ensuring smooth movement of the moving member.

As shown in fig. 1, the axial passage 23 of the camshaft is provided with a hydraulic chamber a, the driving mechanism specifically adopts a hydraulic driving mechanism II, and the hydraulic driving mechanism II is communicated with the hydraulic chamber a through a rotary oil inlet interface device 30. The hydraulic driving mechanism II comprises an electromagnetic directional valve 80, a pressure relief oil path and a one-way oil path, wherein the one-way oil path is provided with a one-way valve 100, the pressure relief oil path is provided with an overflow pressure retaining valve 50, and the pressure relief oil path is provided with a pressure relief valve 200; the electromagnetic directional valve 80 preferably adopts a two-position three-way electromagnetic directional valve, and when the electromagnetic directional valve 80 is powered off, the hydraulic cavity A is communicated with the oil pan 60 through a pressure relief oil path and is communicated with an engine oil path through a pressure reduction oil path; when the electromagnetic directional valve 80 is energized, the engine oil passage supplies oil to the hydraulic chamber a through the one-way oil passage, and the slide plunger 72 extends out of the cam surface of the exhaust cam 22 to form a braking protrusion.

As shown in fig. 1, in this embodiment, the hydraulic chamber a is disposed at the second end of the axial passage 23 of the camshaft, wherein the rotary oil inlet interface device 30 includes a fixed oil sleeve 32, the fixed oil sleeve 32 is provided with an oil through hole 321, the oil through hole 321 is connected to the hydraulic driving mechanism II, 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 hydraulic chamber a through a radial hole, and the oil through hole 321 is communicated with the annular oil groove; the end of the camshaft 20 is provided with a plug 31 that seals the opening of the camshaft axial passage 23, and the space between the plug 31 and the control shaft 71 forms a hydraulic pressure chamber a.

As shown in fig. 4, 5 and 1, when braking is performed in the cylinder, the hydraulic driving mechanism II drives the braking mechanism 70, the engine oil path supplies oil to the hydraulic chamber a through the one-way oil path, the control shaft 71 is pushed to push the sliding plunger 72 to slide along the exhaust cam radial hole in the process of sliding along the camshaft axial passage 23, and the sliding plunger 72 extends out of the cam surface of the exhaust cam 22 to form a braking protrusion, so that braking in the cylinder is achieved. Because the control shaft 71 forcibly pushes the sliding plunger 72 to extend out of the cam surface of the exhaust cam 22 to form a braking protrusion, even if the sliding plunger 72 is pressed down by the tappet 15, the sliding plunger 72 cannot sink due to the support of the control shaft 71, so that the braking is reliable and the braking effect is good.

As shown in fig. 6, 7 and 1, during non-cylinder braking, under the action of the reset mechanism 40, the control shaft 71 is pushed to slide along the axial channel 23 of the camshaft in the reverse direction, and the sliding plunger 72 is driven to slide in the reverse direction to retract the radial hole of the exhaust cam, so that the engine enters a normal operating condition.

Example two

As shown in fig. 2, the compression-release engine in-cylinder brake apparatus of the second embodiment is substantially the same as that of the first embodiment, except that: the hydraulic cavity B corresponds to the mounting journal 26 of the camshaft 20, a space between two adjacent control shafts 71 forms the hydraulic cavity B, the second end of the camshaft axial passage 23 is blocked, the rotary oil inlet interface device 90 is arranged at the mounting journal 26, the rotary oil inlet interface device 90 comprises a camshaft seat 91, end covers 93 are arranged on two sides of the camshaft seat 91, a bearing bush 92 is arranged in the camshaft seat 91, the mounting journal 26 is rotatably and hermetically mounted on the bearing bush 92, a sealing ring 94 is used for achieving oil sealing of a revolute pair, an annular oil groove 261 is formed in the outer peripheral surface of the mounting journal 26, the annular oil groove 261 is communicated with the hydraulic cavity B through a radial hole, oil through holes 911 communicated with the annular oil groove 261 are formed in the camshaft seat 91 and the bearing bush 92, and the oil through holes 911 are connected with a.

In this embodiment, the first end and the second end of the axial passage 23 of the camshaft are respectively provided with the reset mechanism 40, and accordingly, both ends of the camshaft 20 are provided with the camshaft pressure relief holes 25.

The structure at the position of the lubricating oil hole of the original camshaft mounting journal can be modified in the implementation mode, so that the structure is more compact; in addition, because the hydraulic cavity B divides the axial passage 23 of the camshaft into two parts, engine oil enters from the hydraulic cavity B in the middle of the camshaft 20, the moving time proportion of the control shaft 71 can be obviously improved, the in-cylinder braking reaction time of the engine is greatly shortened, and the in-cylinder braking performance is good.

According to the present embodiment, the camshaft axial passage 23 can be divided into two or more parts, and the in-cylinder braking performance is better, but the structure becomes complicated. Such structures are not shown or described in detail herein.

EXAMPLE III

As shown in fig. 3, the compression-release engine in-cylinder brake apparatus of the third embodiment is substantially the same as that of the first embodiment except that: the driving mechanism adopts a linear driving mechanism III, the linear driving mechanism III is arranged close to the second end of the camshaft axial passage 23, the second end of the camshaft axial passage 23 is not closed, and when the cylinder is braked, the linear driving mechanism III pushes a control shaft 71 close to the second end of the camshaft axial passage 23, so that a sliding plunger 72 extends out of the cam surface of the exhaust cam 22 to form a braking bulge. The linear driving mechanism III may be a known linear motor, or a telescopic cylinder (such as a telescopic cylinder, a telescopic electric cylinder), or a linear electromagnet, and is not limited herein.

The above illustration and description are mainly directed to a valve mechanism with a tappet, and the same applies to an overhead valve mechanism without a tappet, and reference may be made to the above embodiments.

The foregoing is an example of the preferred embodiment of the present invention, and the details not described are known to those skilled in the art, and the scope of the present invention is defined by the claims and any equivalent changes based on the teachings of the present invention are within the scope of the present invention.

Claims (15)

1. A compression-release engine in-cylinder brake apparatus, comprising: a camshaft provided with a plurality of exhaust cams; it is characterized in that the preparation method is characterized in that,

the exhaust cam is provided with an exhaust cam radial hole along the radial direction, and the exhaust cam radial hole is communicated with the camshaft axial channel;

the inner part of the camshaft is provided with a braking mechanism corresponding to each exhaust cam, the braking mechanism comprises a sliding plunger and a control shaft which are connected, the sliding plunger is slidably arranged in a radial hole of the exhaust cam, and the control shaft is slidably arranged in an axial channel of the camshaft;

when braking is carried out in the cylinder, the braking mechanism is controlled by a driving mechanism, the control shaft slides along the axial channel of the camshaft and drives the sliding plunger to slide along the radial hole of the exhaust cam, so that the sliding plunger extends out of the cam surface of the exhaust cam to form a braking bulge; when the brake is not in the cylinder, the brake mechanism is controlled by a reset mechanism, and the sliding plunger retracts into the radial hole of the exhaust cam.

2. The compression-release engine in-cylinder brake apparatus as defined in claim 1, wherein said sliding plunger includes a plunger body defining a plunger angled through-hole, said plunger angled through-hole being located within said camshaft axial passage, said plunger angled through-hole being angled with respect to said camshaft axial passage.

3. The in-cylinder brake device of a compression-release engine according to claim 2, wherein the outer end surface of the plunger body is an outwardly convex curved surface, and one end of the plunger body located in the axial passage of the camshaft is provided with a plunger pressure relief hole which is communicated with the plunger inclined through hole.

4. The compression-release engine in-cylinder brake apparatus as defined in claim 2, wherein said control shaft includes a control shaft horizontal section and a control shaft inclined section connected, said control shaft horizontal section conforming to a cross-sectional shape of said camshaft axial passage, said control shaft horizontal section slidably engaging said camshaft axial passage; the control shaft inclined section is mounted in the plunger inclined through hole in a constrained mode and penetrates out of the plunger inclined through hole, the control shaft inclined section is matched with the cross section shape of the plunger inclined through hole, and the control shaft inclined section is in sliding fit with the plunger inclined through hole; the included angle between the control shaft inclined section and the control shaft horizontal section is an inclined angle, and the inclined angle is not larger than the self-locking angle of the control shaft.

5. The compression-release engine in-cylinder brake apparatus as defined in claim 4, wherein a support arc surface is provided on an outer peripheral surface of an end of the control shaft inclined section remote from the control shaft horizontal section, the support arc surface being supported by the camshaft axial passage, the support arc surface being adapted to an arc surface shape of the camshaft axial passage.

6. The compression-release engine in-cylinder brake apparatus as defined in claim 4 or 5, wherein the control shaft is a one-piece member, and the control shaft horizontal section and the control shaft inclined section are directly connected.

7. The compression-release engine in-cylinder brake apparatus as defined in claim 4 or 5, wherein the control shaft is a split member, the horizontal section of the control shaft and the inclined section of the control shaft are connected by a pin, the end surface of the horizontal section of the control shaft is provided with two opposite connecting portions, the end of the inclined section of the control shaft is provided with an end through hole, and the pin passes through the end through hole and is mounted to the connecting portion.

8. The compression-release engine in-cylinder brake apparatus as defined in claim 1, wherein a carrier rod is provided between adjacent ones of said control shafts in said camshaft axial passage, an end of said carrier rod abutting against an end of said control shaft.

9. The compression-release engine in-cylinder brake apparatus as defined in claim 1, wherein the first end of the axial passage of the camshaft is a closed end, the return mechanism is disposed at the first end of the axial passage of the camshaft, the return mechanism includes a return spring and a retainer seat, one side of the retainer seat abuts against the return spring, and the other side of the retainer seat abuts against the control shaft.

10. The compression-release engine in-cylinder brake apparatus as defined in claim 9, wherein said camshaft is provided with a camshaft relief hole, said camshaft relief hole communicating with said camshaft axial passage, said camshaft relief hole being provided near an end of said camshaft and on a wall of said camshaft between said retainer seat and said exhaust cam.

11. The compression-release engine in-cylinder brake apparatus as defined in claim 1, wherein said camshaft axial passage is provided with a hydraulic chamber, said drive mechanism is a hydraulic drive mechanism, said hydraulic drive mechanism is communicated with said hydraulic chamber by a rotary oil-intake interface means;

the hydraulic driving mechanism comprises an electromagnetic directional valve, a pressure relief oil way and a one-way oil way, wherein the one-way oil way is provided with a one-way valve, the pressure relief oil way is provided with an overflow pressure retaining valve, and the pressure relief oil way is provided with a pressure relief valve; when the electromagnetic directional valve is powered off, the hydraulic cavity is communicated with an oil pan through the pressure relief oil way and is communicated with an engine oil way through the pressure relief oil way; when the electromagnetic directional valve is electrified, the engine oil circuit supplies oil to the hydraulic cavity through the one-way oil circuit, and the sliding plunger extends out of the cam surface of the exhaust cam to form a braking bulge.

12. The in-cylinder brake device of a compression-release engine according to claim 11, wherein the hydraulic chamber is disposed at the second end of the axial passage of the camshaft, and the rotary oil inlet port device comprises a fixed oil sleeve, the fixed oil sleeve being provided with an oil passage hole, the oil passage hole being connected to the hydraulic drive mechanism, the camshaft being provided with an oil inlet journal, the oil inlet journal being rotatably and sealingly mounted to the fixed oil sleeve, an annular oil groove being formed in an outer circumferential surface of the oil inlet journal, the annular oil groove being communicated with the hydraulic chamber, the oil passage hole being communicated with the annular oil groove; the end of the camshaft is provided with a plug sealing the opening of the axial passage of the camshaft, the space between the plug and the control shaft forming the hydraulic chamber.

13. The compression-release engine in-cylinder brake apparatus as defined in claim 11, wherein the hydraulic chamber corresponds to a mounting journal of the camshaft, a space between two adjacent control shafts forms the hydraulic chamber, a second end of the axial passage of the camshaft is blocked by a plug, the rotary oil inlet interface is disposed at the mounting journal of the camshaft, and the rotary oil inlet interface comprises: the camshaft comprises a camshaft seat, wherein a bearing bush is arranged in the camshaft seat, the mounting shaft neck is rotatably and hermetically mounted on the bearing bush, an annular oil groove is formed in the outer peripheral surface of the mounting shaft neck, the annular oil groove is communicated with the hydraulic cavity, oil through holes communicated with the annular oil groove are formed in the camshaft seat and the bearing bush, and the oil through holes are connected with the hydraulic driving mechanism.

14. The compression-release engine in-cylinder brake apparatus as defined in claim 13, wherein the first and second ends of the camshaft axial passage are provided with the return mechanism, respectively.

15. The compression-release engine in-cylinder brake apparatus as defined in claim 1, wherein said actuating mechanism is a linear actuating mechanism disposed adjacent to said second end of said camshaft axial passage, said linear actuating mechanism pushing said control shaft adjacent to said second end of said camshaft axial passage during in-cylinder braking to extend said sliding plunger beyond said cam surface of said exhaust cam to form a braking lobe.

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