CN202065024U - Valve gear of engine - Google Patents

Abstract

The utility model relates to a valve gear of an engine, which comprises a camshaft, a one-way clutch, a decompression cam, a rocker mechanism, a pushing piece and an elastic piece, wherein the one-way clutch is sheathed onto the camshaft; the decompression cam is fixedly arranged on the peripheral face of the outer ring of the one-way clutch and is provided with a working part and a stop part; the rocker mechanism is provided with a rocker and a rocker shaft; the pushing piece is pivotally arranged on the rocker shaft and comprises an abutting part, a driving part and a backstop part; and the elastic piece is simultaneously abutted with the pushing piece and the rocker. When the camshaft rotates anticlockwise, the driving part is driven by the working part to push a driven part, so that the rocker rotates; and when the camshaft rotates clockwise, the stop part is abutted with the backstop part. Thereby, when the valve gear of the engine simultaneously has an engine decompression function and a valve noise elimination function, the use number of the elastic piece is reduced, and moreover, the configuration structure of the valve gear is simplified.

Description

The engine valve mechanism

Technical field

The utility model relates to a kind of valve mechanism of engine, refers to a kind of engine valve mechanism with rocking arm especially.

Background technique

The engine valve mechanism is to be mounted in the cylinder head, can enter the firing chamber with control oil gas by the open and close of valve and be burnt, and impels engine running, and then waste gas is discharged.Generally in order to ensure valve can close, factor such as reason rising-heat contracting-cold effect does not cause gas to leak, can make between rocking arm and the valve rod or keep a gap between rocking arm and the cam base circle in advance.Yet, will cause temperature rising in the cylinder head by starting a cold engine engine to hot car process, the effect of expanding with heat and contract with cold that this temperature fall produced will make the valve clearance of cylinder head for internal combustion engines change, the different sound when this gap causes valve opening easily and closes.

When cutting the engine,,, stop at last again there being many impedance meetings to cause rotating under the gradual slow among this process because the effect of inertia that bent axle is rotatablely moved makes engine can continue to rotate some revolutions.Wherein Zui Da impedance is the compression pressure of compression stroke, therefore often makes engine be subjected to the effect of this compression pressure and counter-rotating after causing normal rotation to stop, and stops then.

When engine will restart, the piston in the cylinder moved to the firing chamber, and all be in closed condition because of suction valve and outlet valve this moment, so must overcome the interior extruded gas pressure of cylinder to finish the mobile of remainder when piston moves.That is, no matter be to start or the artificial application of force starts, all must provide enough moment of torsion to overcome the gas pressure in the aforementioned cylinder with electric motor.If start with electric motor, then electric motor must be designed to have than the high pulling torque specification, can't miniaturization and increase cost; If start with the artificial application of force again, for example trample to start the occasion of locomotive engine at need, then can cause trampling difficult and the burden increase user.

The model utility content

The purpose of this utility model provides a kind of engine valve mechanism, can have system sound function and decompression simultaneously.

The purpose of this utility model is achieved in that the engine valve mechanism comprises a camshaft, an overrunning clutch, a relief cam, a rocker arm body, an ejector and an elastic component.Above-mentioned overrunning clutch is sheathed on camshaft, transmitting torque when camshaft reverses.

Above-mentioned relief cam is fixedly arranged on the outer shroud side face of overrunning clutch, includes a working part and a retainer.Above-mentioned rocker arm body includes a rocking arm and a pitman arm shaft, and rocking arm is hubbed at pitman arm shaft and includes a valve end and and is driven portion.

Above-mentioned ejector includes a butting section, a drive portion and a blocked part.Elastic component is replaced ejector and rocking arm respectively, makes ejector and rocking arm counterrotating.Ejector can be hubbed at pitman arm shaft or rocking arm.

When camshaft reversed, working part drove the drive portion ejection and is driven portion, and rocking arm is rotated; When camshaft just changeed, retainer was resisted against the blocked part.

Above-mentioned elastic component can be a torsion spring, includes a spiral section, a rocking arm end that extends respectively from the spiral section two ends and an ejection end, and wherein spiral section is set in pitman arm shaft, and the rocking arm end is resisted against rocking arm, and the ejection end is resisted against ejector.

The said cylinder head can be slidingly equipped with a valve rod, and valve rod includes a masthead end.The configuration of elastic component impels the valve end of rocking arm to be pressed on the masthead end towards convergence.

Cylinder head can include a cover plate, and elastic component impels the butting section contact of ejector to be resisted against cover plate.The blocked part can be a hook arrangement, and disposes with the retainer subtend.

Valve mechanism design of the present utility model only uses an elastic component that location ejector (belonging to engine decompression associated mechanisms) and elimination rocking arm and the required strength in gap, valve rod top can be provided simultaneously.

Description of drawings

Fig. 1 is the engine part exploded view of the utility model first preferred embodiment.

Fig. 2 is that the engine of the utility model first preferred embodiment partly disconnects stereogram.

Fig. 3 is the engine phantom of the utility model first preferred embodiment when camshaft just changes.

Fig. 4 is Fig. 3 partial enlarged drawing.

Fig. 5 is the engine phantom of the utility model first preferred embodiment when camshaft reverses.

Fig. 6 is the engine part stereogram of the utility model second preferred embodiment.

Fig. 7 is the engine phantom of the utility model second preferred embodiment.

Fig. 8 is the engine part exploded view of the utility model the 3rd preferred embodiment.

Fig. 9 is the engine part stereogram of the utility model the 3rd preferred embodiment.

The primary component symbol description

Cylinder head 10 camshaft holders 11

Cover plate 12 bolts 14

Nut 15 valve rod 16a, 16b

Masthead end 161 camshafts 21

Valve actuation cam 22 relief cams 23

Outer circumferential face 230 working part 231

Retainer 232 overrunning clutchs 24

Rocker arm body 30a, 30b rocking arm 31,41

Valve end 311,413 is driven portion 312,412

Cam action end 313 pitman arm shafts 32

Ejector 33,40 butting sections 331,401

Drive portion 332,402 blocked parts 333

Elastic component 34,42 spiral sections 341

Ejection end 342 rocking arm ends 343

Axis hole 411 spacing H

Embodiment

With reference to figure 1 and Fig. 2, be that the engine part exploded view of first preferred embodiment disconnects stereogram with part.Show the cylinder head 10 of an engine among the figure, cylinder head 10 includes a camshaft holder 11, projection has four bolts, 14, one U type cover plates 12 to be passed by four bolts 14 and is carried on camshaft holder 11 end faces on camshaft holder 11 end faces, and four bolts 14 are screwed together in four nuts 15 and with cover plate 12 location.Cover plate 12 acts on as pad.

Also be slidingly equipped with corresponding two rocker arm body 30a in the cylinder head 10,30b and two valve rod 16a, 16b.One camshaft 21 is arranged in camshaft holder 11 rotationally, is installed with two valve actuation cams 22 (is air inlet usefulness, and is exhaust usefulness) on the camshaft 21.

Some composition of two rocker arm bodies is identical, and this sentences rocker arm body 30a is the example explanation, and it comprises a rocking arm 31 and a pitman arm shaft 32, and wherein rocking arm 31 is hubbed at this pitman arm shaft 32, and pitman arm shaft 32 is located in camshaft holder 11.Rocking arm 31 two ends form a valve end 311 and a cam action end 313 respectively, valve end 311 correspondences are resisted against the masthead end 161 of valve rod 16a, cam action end 313 is corresponding to valve actuation cam 22, and wherein valve end 311 and cam action end 313 lay respectively at the two opposite sides of rocking arm self pivot axis.Cam action end 313 is a roller kenel end in this example.Specifically, rocker arm body 30a more than rocker arm body 30b moreed and is located at one of rocking arm 31 side direction and is driven portion 312, for example a projection.

Also be provided with a relief cam 23, an overrunning clutch 24, above-mentioned rocker arm body 30a, an ejector 33 and an elastic component 34 in the cylinder head 10.Overrunning clutch 24 is sheathed on camshaft 21, transmitting torque when camshaft 21 reverses.Its general meaning is not lost in the just commentaries on classics of so-called camshaft 21, is meant the rotation of engine camshaft 21 corresponding specific directions under running well, and reverses then to be and the former backward rotation.

Relief cam 23 is fixedly arranged on the outer shroud side face of overrunning clutch 24, includes a working part 231 and a retainer 232.In this example retainer 232 be one along peripheral, oblique extend, similar structure of colluding shape.Ejector 33 is hubbed at pitman arm shaft 32, includes the butting section 331, a drive portion 332 and the blocked part 333 that link to each other in regular turn.Blocked part 333 also is a hook arrangement and disposes with retainer 232 subtends in this example.

Elastic component 34 is replaced ejector 33 and rocking arm 31 respectively, makes ejector 33 and rocking arm 31 counterrotatings.In this example, elastic component 34 is torsion springs, includes a spiral section 341, a rocking arm end 343 that extends respectively from spiral section 341 two ends and an ejection end 342.Spiral section 341 is set in pitman arm shaft 32, and rocking arm end 343 is resisted against the valve end 311 of rocking arm 31, and ejection end 342 is resisted against ejector 33.Make the valve end 311 of rocking arm 31 be pressed on masthead end 161 by elastic component 34, also make butting section 331 contacts of ejector 33 be resisted against cover plate 12 towards convergence.

With reference to figure 1, Fig. 3 and Fig. 4, Fig. 3 is the engine phantom when camshaft just changes simultaneously, and Fig. 4 is a partial enlarged drawing.When camshaft 21 was just changeing, overrunning clutch 24 can not be coupled basically and follow rotation.But because of inevitable frictional force between camshaft 21 and overrunning clutch 24 bodies and roller thereof is a little just changeed it, so the retainer 232 on the overrunning clutch 24 also can be followed rotation.When retainer 232 goes to the blocked part 333 of contact and compressing ejector 33 gradually, because of being resisted against cover plate 12, the butting section 331 of ejector 33 keeps motionless, and so also allow retainer 232, overrunning clutch 24 and relief cam 23 all keep static.This moment, engine there is no decompression.

Specifically, because cylinder head 10 is provided with cover plate 12, when the butting section 331 of ejector 33 is resisted against cover plate 12, blocked part 333 can only contact to replace at retainer 232 and not contact the relief cam outer circumferential face of replacing lower 230, and just a spacing H is left with relief cam outer circumferential face 230 in blocked part 333.

With reference to figure 1 and Fig. 5, Fig. 5 is the engine phantom when camshaft reverses simultaneously.When reversing, camshaft 21 cause overrunning clutch 24 and the relief cam 23 on it also to rotate synchronously, the working part 231 of relief cam 23 outwards promotes blocked part 333, and then make the portion that is driven 312 of drive portion 332 corresponding ejection rocking arm 31 side direction, finally cause rocking arm 31 to rotate.Rocking arm 31 rotates and means that also its valve end 311 can be rotated and 16 displacements of promotion valve rod, reaches the engine effect of easing stress.

Utilize structure of the present utility model to reach and only use an elastic component 34 that rocking arm 31 and the pre-power of mechanism of decompressor ejector 33 required elasticity promptly are provided simultaneously, reduce the usage quantity of elastic component, reduce the structural arrangements of whole cost and simplification valve mechanism.

With reference to figure 6 and Fig. 7, be second embodiment's engine part stereogram and sectional view.The difference of the present embodiment and first example is in cylinder head 10 cover plate is not set.In the case, owing to lack the element that to replace the location for butting section 331, the application of force of elastic component 34 will make the blocked part 333 of ejector 33 be contacted with the outer circumferential face 230 of relief cam 23, impel the blocked part 333 of ejector 33 when engine just changes to be contacted with the outer circumferential face 230 and retainer 232 of relief cam 23 simultaneously.

With reference to figure 8 and Fig. 9, be the 3rd embodiment's engine part exploded view and stereogram.This example is that with the main difference of a last example portion that is driven 412 of Rocker arm 41 is near upwards projection axis hole 411, and the butting section 401 of ejector 40 constitutes a L type cross section with drive portion 402 from the end face view.Elastic component 42 is to replace respectively in the butting section 401 of ejector 40 and the valve end 413 of Rocker arm 41 equally.

The foregoing description only is to give an example for convenience of description, and the interest field that the utility model is advocated should be as the criterion so that claim is described certainly, but not only limits to the foregoing description.

Claims (6)

1. an engine valve mechanism is to be assembled in the cylinder head, it is characterized in that comprising:

One camshaft;

One overrunning clutch is sheathed on this camshaft, transmitting torque when this camshaft reverses;

One relief cam is fixedly arranged on the outer shroud side face of this overrunning clutch, includes a working part and a retainer;

One rocker arm body includes a rocking arm and a pitman arm shaft, and this rocking arm is hubbed at this pitman arm shaft and includes a valve end and and is driven portion;

One ejector includes a butting section, a drive portion and a blocked part; And

One elastic component is replaced this ejector and this rocking arm respectively, makes this ejector and this rocking arm counterrotating;

Wherein, when this camshaft reversed, this working part drives this drive portion ejection, and this was driven portion, and this rocking arm is rotated, and when this camshaft was just changeing, this retainer was resisted against this blocked part.

2. engine valve mechanism as claimed in claim 1, it is characterized in that this elastic component is a torsion spring, include a spiral section, extend a rocking arm end and an ejection end respectively from these spiral section two ends, this spiral section is set in this pitman arm shaft, this rocking arm end is resisted against this rocking arm, and this ejection end is resisted against this ejector.

3. engine valve mechanism as claimed in claim 1 is characterized in that this cylinder head is slidingly equipped with a valve rod, and this valve rod includes a masthead end, and this elastic component is to impel this valve end of this rocking arm to be pressed on this masthead end towards convergence.

4. engine valve mechanism as claimed in claim 1 is characterized in that this cylinder head includes a cover plate, and this elastic component is to impel this butting section contact of this ejector to be resisted against this cover plate.

5. engine valve mechanism as claimed in claim 1 is characterized in that this portion of being driven is in this rocking arm side direction projection.

6. engine valve mechanism as claimed in claim 1 is characterized in that this portion of being driven is in the projection that makes progress of this rocking arm.

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