CN201588666U - Engine pressure-release device - Google Patents

Abstract

The utility model relates to an engine pressure-release device which comprises a cam shaft, a one-way clutch sleeved on the cam shaft, a pressure reducing cam fixedly arranged on the outer circumferential surface of the one-way clutch, a stopping part fixedly arranged on the outer circumferential surface of the one-way clutch, a valve driving part, a stopper pivotally arranged on an arm shaft of the valve driving part, and an elastic component used for positioning the stopper. When the cam shaft rotates clockwise, the stopping part is pivotably propped against the stopper; so that, a hole for fixing the stopper is not required to be additionally processed on the cylinder head structure, the number of parts is reduced, the cost is reduced, and the engine pressure-release device can be suitable for an integral or separated cylinder head.

Description

The engine decompressor

Technical field

The utility model is about a kind of decompressor, refers to a kind of decompressor that is applicable to power engine especially.

Background technique

When cutting the engine,,, stop at last 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 when starting, the piston in the cylinder moves to the firing chamber, and all be in closed condition because of suction valve and outlet valve this moment, so piston must overcome in the cylinder extruded gas pressure to finish the mobile of remainder when mobile.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.

As everyone knows, in order to solve above-mentioned stress problems, some engine can be installed the decompressor with overrunning clutch, when stopping, depending on by engine bent axle that rotatory inertia continues to rotate in the before top dead center of compression stroke, when stopping the rotation the back counter-rotating because of the cylinder pressure rising, form connecting state by the overrunning clutch that is installed between camshaft and the relief cam, relief cam together rotates with camshaft, replace rocking arm and then open suction valve and at least one of outlet valve by the cam part of relief cam, make the pressure in the cylinder to release, therefore can alleviate next time and start required positive torque, help engine start by the startup starting motor driving bent axle or the artificial application of force.Such decompressor can be set in relief cam fixing position, so the External Ring of One-way Clutch side face also convexes with retainer in addition except being provided with relief cam, then must be drilled with a device hole on the Structure of cylinder head.The block of setting-in location usefulness in order to prop up the retainer of overrunning clutch, makes relief cam be blocked in the position of regulation in the device hole, and other has spring housing to be located in the rotating shaft of block, in order to locate this block in special position.

With reference to figure 1 and Fig. 2, be known engine cylinder head fragmentary, and sectional view.Demonstrate among the figure and be provided with a camshaft 91 in the cylinder head 90, reach a valve driver element 92.Group is provided with an overrunning clutch 93 on the camshaft 91, is installed with a relief cam 94 on the overrunning clutch 93 outer shroud side faces highlightedly, reaches a retainer 95.One location is hubbed at the camshaft holder 901 of cylinder head 90 with the rotating shaft of riveted one with block 96.Because of needing additional processing, rotary shaft hole comes out, so if make more uneconomical and at the engine of integral type cylinder head, above-mentioned location just is difficult to reach with the mounting type of block 96.

The model utility content

The purpose of this utility model is to provide a kind of engine decompressor, does not need on Structure of cylinder head additional processing to be used for fixing the device hole of block again, reduces number of parts, reduces cost.

Engine decompressor of the present utility model comprises a camshaft, an overrunning clutch, a relief cam, a retainer, a valve driver element, reaches a block.Above-mentioned overrunning clutch is sheathed on the camshaft, and it is provided with direction is camshaft transmitting torque when reversing.Camshaft is just changeing the rotation of guiding camshaft when holding up normal operation, otherwise then is that camshaft reverses (counter-rotating).

Relief cam and retainer all are fixedly arranged on the outer shroud side face of overrunning clutch, and relief cam includes a working part.Above-mentioned valve driver element includes an arm axle, an arm, and wherein arm is hubbed at arm axle.Block also is hubbed on the arm axle of valve driver element, and includes a blocked part, and wherein when camshaft just changes, retainer pivots and correspondence is resisted against the blocked part.The engine decompressor also comprises an elastic component, can positively replace cylinder head and locatees by the restoring force block of elastic component.

By said apparatus, under engine runs well,, make retainer on the overrunning clutch be resisted against the blocked part of block because of camshaft just changes, reach the location relief cam in the purpose of assigned position.On the other hand, compared to the set-up mode of known block, the utility model adopts the mode that block is located on the single arm axle to save the trouble of reserving a bolt device hole in cylinder head, also thereby economized procedure one.

Above-mentioned block can more include a butting section, the butting section can pivot and contact to replace or do not contact and replace cylinder head, and making retainer when block is touched in the below near a circle when camshaft reverses, retainer also can flexibly promote block easily to be made its rotation and gets back to original position.Above-mentioned butting section can be the cover plate that cylinder head was replaced or disengaged in contact.Above-mentioned elastic component can be torsion spring or extension spring.

Above-mentioned relief cam and retainer can stagger on axially or be overlapping in axially going up.Above-mentioned valve driver element can be a rocking arm type valve driver element or a swing-arm type valve driver element.Above-mentioned retainer can include a plane of inclination, and is outward-dipping along the positive veer of camshaft.

The utility model has the advantages that does not need on Structure of cylinder head additional processing to be used for fixing the device hole of block again, reduces number of parts, reduces cost, on integral type or separating casing head.

Description of drawings

Fig. 1 is known engine cylinder head fragmentary.

Fig. 2 is known engine cylinder head sectional view.

Fig. 3 is the engine cylinder head stereogram of the utility model first preferred embodiment.

Fig. 4 is the engine cylinder head fragmentary of the utility model first preferred embodiment.

Fig. 5 is the decompressor exploded view of the utility model first preferred embodiment.

Fig. 6 is the engine cylinder head sectional view of the utility model first preferred embodiment.

Fig. 7 is the engine cylinder head stereogram of the utility model second preferred embodiment.

Fig. 8 is the engine cylinder head fragmentary of the utility model second preferred embodiment.

Fig. 9 is the decompressor exploded view of the utility model second preferred embodiment.

Figure 10 is that the relief cam of the utility model second preferred embodiment is not made time spent engine cylinder head sectional view.

Figure 11 is the engine cylinder head sectional view that the utility model second preferred embodiment relief cam is done the time spent.

Figure 12 is the decompressor exploded view of the utility model the 3rd preferred embodiment.

Figure 13 is the engine cylinder head sectional view of the utility model the 4th preferred embodiment.

Figure 14 is the engine cylinder head stereogram of the utility model the 5th preferred embodiment.

Figure 15 is the engine cylinder head fragmentary of the utility model the 5th preferred embodiment.

Symbol description

Cylinder head 90 camshaft holders 901

Camshaft 91 valve driver elements 92

Overrunning clutch 93 relief cams 94

Retainer 95 blocks 96

Cylinder head 10 camshaft holders 101

Cover plate 102 camshafts 11

Intake cam 111 exhaust cams 112

Sprocket wheel 113 overrunning clutchs 12,31

Oil duct 121 relief cams 13,32

Working part 131,321 suction valve actuators 14

Roller 141,151,42 arm axles 142,152,45

Arm 143,34,41 are driven portion 144,341,43

Outlet valve actuator 15 ejectors 16,35,44,52

Butting section 161 drive portions 162

Block 17 butting sections 171

Blocked part 172 retainers 18,33

Tappet 21 torsion springs 22,23,46

Contacting part 351 epitaxial raised 352

Hub side 411 fixed ends 412

Decompressor 51 axial X

The positive veer N camshaft of camshaft reverse direction R

Embodiment

With reference to figure 3～6, be respectively the utility model first embodiment's engine cylinder head stereogram, fragmentary, decompressor exploded view, and cylinder head sectional view.Show the cylinder head 10 of an engine cylinder among the figure, and decompressor is assembled wherein promptly.Decompressor includes camshaft 11, overrunning clutch 12, relief cam 13, two valve driver elements 14,15, ejector 16, block 17, reaches a retainer 18.Being installed with two valve actuation cams and a sprocket wheel 113, two valve actuation cams on the camshaft 11 is intake cam 111 and exhaust cam 112, and wherein intake cam 111 is near sprocket wheel 113.

Overrunning clutch 12 is to be set in camshaft 11, and its cover set direction is a transmitting torque when camshaft 11 reverses, and uses a roller-type overrunning clutch in this example.Its general meaning is not lost in the just commentaries on classics of so-called camshaft 11, is meant the rotation of engine camshaft 11 corresponding specific directions under running well, and reverses then to be and the former backward rotation.Also offer an oil duct 121 on the overrunning clutch 12, provide lubricant oil to enter in order between lubricated overrunning clutch 12 and the camshaft 11.

Relief cam 13 is to be fixedly arranged on the outer shroud side face of overrunning clutch 12, and therefore when overrunning clutch 12 reversed transmitting torque because of camshaft 11, relief cam 13 was followed rotation, otherwise it is motionless basically when just changeing.Relief cam 13 includes a working part 131, and this promptly exceeds basic circle and with so that valve driver element 14 produces primary deflector when engine stops and then impelling tappet 21 to open the cylinder valves.In addition, retainer 18 is convex, is installed in equally on the outer shroud side face of overrunning clutch 12.Relief cam 13, retainer 18, and overrunning clutch 12 framies part can see through one-body molded mode and produce.Retainer 18 is to be positioned at the axial X position different with relief cam 13 in this example, and relief cam 13 is near intake cams 111.Retainer 18 includes a plane of inclination, and it is outward-dipping along the positive veer of camshaft.

Two valve driver elements 14,15 are respectively applied for air intake valve and drain tap (figure does not show), be called suction valve actuator 14, with outlet valve actuator 15, intake cam 111 on the camshaft 11 also just corresponds respectively to above-mentioned two valve driver elements 14 with exhaust cam 112,15 roller 141,151 and being provided with.With suction valve actuator 14 is example, and it includes an arm axle 142, an arm 143, reaches a roller 141, and outlet valve actuator 15 has same composition.Be placed in two sides of camshaft of two valve driver elements 14,15.

Valve driver element 14 used in this example is the rocking arm type valve driver element, so arm 143 is a rocking arm.Arm 143 is hubbed at arm axle 142 and side direction (being axial X in this example) and is provided with what protruding kenel presented and one is driven portion 144, and roller 141 is located in the forked end of arm 143 pivotly.

Cylinder head 10 includes a camshaft holder 101, above-mentioned camshaft 11, and the arm axle 142,152 of two valve driver elements be placed through camshaft holder 101 with being arranged in parallel, in the middle of camshaft 11 is positioned at.Cylinder head 10 also comprises a cover plate 102, is that locking is on camshaft holder 101.This routine cam axle bed 101 is the separated type camshaft holder.

Ejector 16 is set in the arm axle 142 of suction valve actuator 14 rotationally, and two ends are respectively butting section 161, reach drive portion 162.Replace a torsion spring 22 of ejector 16 and camshaft holder 101 respectively through being set in arm axle 142 and two ends, the butting section 161 of ejector 16 just is resisted against the cover plate 102 that is locked in camshaft holder 101.The below of drive portion 162 and top be respectively radially corresponding to the portion that is driven 144 on the working part 131 of relief cam 13 and the arm 143, and meaning is the pushing tow of the working part 131 that can be rotated of drive portion 162 and related pushing tow is driven portion 144.

Specifically, the external force that is subjected to a camshaft reverse direction when the drive portion 162 of ejector 16 is during for example from the promotion of relief cam 13, ejector 16 begins to pivot and then with drive portion 162 goes to touch, pusher arm 143 the is other portion that is driven 144, therefore the arm 143 of valve driver element 14 will rotate, cause tappet 21 to move Open valve at last, reach the engine effect of easing stress.

Block 17 is to be set in rotationally on the arm axle 152 of outlet valve actuator 15, includes a butting section 171 and a blocked part 172.See through two ends and replace a torsion spring 23 of block 17 and camshaft holder 101 respectively, the butting section 171 of block 17 just is resisted against the cover plate 102 that is locked in camshaft holder 101, and blocked part 172 is radially corresponding to the retainer 18 on the overrunning clutch 12 outer shroud side faces.

Block 17 description of uses are as follows.Though overrunning clutch 12 can not be coupled ideally and follows rotation when camshaft 11 was just changeing, but in fact still can be because of camshaft 11 and overrunning clutch 12 bodies and the inevitable frictional force of roller thereof are a little just changeed it, so the retainer 18 on the clutch also can be followed rotation.When retainer 18 goes to contact and compressing block blocked part 172 gradually, the cover plate 102 that is resisted against camshaft holder 101 because of the butting section 171 of block 17 keeps motionless so blocks are whole, so also allow retainer 18, overrunning clutch 12, and relief cam 13 all keep static.

Under utmost point special case, when reversing, camshaft 11 make retainer 18 when block 17 is touched in the below near a circle, because of block 17 itself can pivot, to make retainer 18 can flexibly promote block 17 easily and make it rotate (cover plate 102 of block butting section 171 disengaging camshaft holders 101 at this moment), and then get back to original position.

With reference to figure 7～9, be second embodiment's cylinder head stereogram, fragmentary, and decompressor exploded view.Present embodiment decompressor structure is roughly identical with first embodiment, its difference place such as following: camshaft holder 101 is that to act on outlet valve actuator and retainer 33 be to be positioned at the axial position identical with relief cam 32 working part 321, retainer 33 and relief cam 32 all radially corresponding to ejector 16 for integral type camshaft holder, ejector 16, just the two is at the same outer shroud section of overrunning clutch 31, and the two has a predetermined circumferential distance.Also because this particular arrangement can allow ejector 16 have the function of block simultaneously, the blocked part effect of aforementioned block is responsible for by the drive portion 162 of ejector 16; Yes in the butting section of block is replaced by the butting section 161 of ejector 16.Hence one can see that, two spare parts of block and ejector must be set simultaneously in engine, saved cost of material and reduced number of assembling steps.

With reference to Figure 10 and Figure 11, be respectively the relief cam effect, with make the cylinder head sectional view of time spent.When engine runs well and camshaft 11 when just changeing, positive veer such as reference numbers N, retainer 33 on the overrunning clutch 31 can be resisted against the drive portion 162 of ejector 16, be resisted against the cover plate 102 of camshaft holder 101 because of the butting section 161 of ejector 16 this moment, so can keep overrunning clutch 31, relief cam 32, reach retainer 33 transfixions.This moment, relief cam 32 did not act on.

When engine stops and camshaft 11 is reversed, reverse direction such as reference numbers R, relief cam 32 on the overrunning clutch 31 touches and promotes the drive portion 162 of ejector 16 with its working part 321, and then make drive portion 162 be changeed the also portion that is driven 144 on pusher arm 143 sides, and the butting section 161 of ejector 16 is to separate with the cover plate 102 of camshaft holder 101 at this moment.

It is relevant that the circumferential distance of retainer 33 and 321 of relief cam working part and camshaft 11 stop back reverse amount, can obtain this information with prior experiment or emulation according to various occasion conditions.

With reference to Figure 12, be the utility model the 3rd embodiment's decompressor exploded view.This embodiment and second example are roughly the same, only difference is that the arm 34 other portions that are driven 341 are grooves, and the drive portion of ejector 35 includes a contacting part 351, and enters a epitaxial raised 352 in the groove from contacting part 351 side extendings, ejector 35 be with its contacting part 351 radially corresponding to retainer 33, and relief cam working part 321, and with epitaxial raised 352 radially corresponding to groove.This structure also can be brought into play function same as the previously described embodiments.

With reference to Figure 13, be the utility model the 4th embodiment's cylinder head sectional view.This example mainly is to illustrate that it is the engine of a swing-arm type valve driver element that decompressor of the present utility model also is useful in when valve driver element.The swing-arm type valve driver element is as the term suggests the hub side 411 of its arm 41 is at an end, and roller 42 is that the position is between hub side 411 and tappet fixed end 412.Similarly, swing arm 41 sides are provided with the portion that is driven 43 towards axial X projection, are a projection, and an ejector 44 sees through torsion spring 46 and is hubbed on the arm axle 45.This example also has characteristics to be, camshaft 11 and on overrunning clutch 12, valve actuation cam (figure only shows exhaust cam 112) and relief cam 32 all the position above valve driver element.This routine relief cam 32 also is arranged on same axial position as second embodiment with retainer 33.

With reference to Figure 14,15, be the utility model the 5th embodiment's cylinder head stereogram, fragmentary.Present embodiment illustrates that mainly decompressor 51 also can be arranged on close sprocket wheel 113 1 sides and be the side near suction valve actuator 14, and just in the decompressor 51, ejector 52 is and suction valve actuator 14 interacts.Certainly, near sprocket wheel 113 also not necessarily must be intake rocker (or swing arm) as the exposure of above-mentioned each example, also can be exhaust rocker arm (or swing arm), no matter and be any design, decompressor of the present utility model equally all is suitable for, this be know that skill person can think easily and variation.

Though camshaft holder of the foregoing description and cylinder head are the occasion of bulk-breaking, the utility model also is useful in camshaft holder and the cylinder head person of being one of the forming, and the personage who knows this technical field uses when doing easily in this way after reading this specification.

Claims (8)

1. an engine decompressor is installed in a cylinder head, it is characterized in that this engine decompressor comprises:

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;

One retainer is fixedly arranged on the outer shroud side face of this overrunning clutch;

One valve driver element includes an arm axle, an arm, and this arm is hubbed at this arm axle;

One block is hubbed at this arm axle of this valve driver element, includes a blocked part, and wherein when this camshaft is just changeing, this retainer pivots and correspondence is resisted against this blocked part; And

One elastic component is positioned these block pushing and pressing for this cylinder head.

2. engine decompressor according to claim 1 is characterized in that this block includes a butting section, and this butting section can pivot and contact to replace or do not contact and replace this cylinder head.

3. engine decompressor according to claim 2 is characterized in that this butting section is the cover plate that the camshaft holder of this cylinder head is replaced in contact.

4. engine decompressor according to claim 1 is characterized in that this relief cam and this retainer stagger on axially.

5. engine decompressor according to claim 1 is characterized in that this relief cam and this retainer are overlapping in axially going up.

6. engine decompressor according to claim 1 is characterized in that this valve driver element is a rocking arm type valve driver element.

7. engine decompressor according to claim 1 is characterized in that this valve driver element is a swing-arm type valve driver element.

8. engine decompressor according to claim 1 is characterized in that this retainer includes a plane of inclination, and is outward-dipping along the positive veer of this camshaft.

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