CN1283908C - Decompressor for engine - Google Patents

Abstract

First and second contact parts 56, 57 are interlinked and coupled with an exhaust valve 28 or an intake valve, and are installed to a cam follower 40. A valve cam slidably contacting with the first contact part 56 is installed to a camshaft 36, and a decompression cam 65 slidably contacting the second contact part 57 in a compression stroke is integrally installed to a rotor with a rotary solenoid 66 rotatable around the same axial line as the camshaft 36. A one-way clutch 67 connecting the decompression cam 65 and the camshaft 36 according to the rotation of a rotor due to excitation of the rotary solenoid 66 is installed between the decompression cam 65 and the camshaft 36.

Description

The decompressor of motor

Technical field

The present invention relates to the decompressor of motor, the particularly relevant improvement of having used the decompressor of electromagnetism coil.

Background technique

Used the decompressor of electromagnetism coil, open clear 62-135806 communique and spy and open flat 4-148008 communique etc. by for example real by known, in these communiques, in compression stroke, exhaust valve is opened by the electromagnetism coil, when engine start, extract the compression pressure of motor, improve the startability of motor in view of the above.

But in above-mentioned existing technology, the electromagnetism coil be because must bring into play the compulsory power that exhaust valve is opened, thus be necessary to use electromagnetism coil than relatively large, and bindiny mechanism between binding electromagnetism coil and the exhaust valve etc. must be arranged.

The present invention is exactly in view of relevant situation, can use small-sized electromagnetism coil and not need the decompressor of the motor of bindiny mechanism etc. to be purpose to provide a kind of.

Summary of the invention

In order to achieve the above object, the described invention of first technological scheme, it is characterized in that, possessing has: with exhaust valve or intake valve interlock, when linking, be provided with the cam follower of the 1st and the 2nd contacting part, with the camshaft that is provided with the valve cam of aforementioned the 1st contacting part sliding contact, and have and the rotor electromagnetism coil of this camshaft around the rotary rotor of same axis, and can be with aforementioned the 2nd contacting part sliding contact in compression stroke, be wholely set at aforementioned epitrochanterian relief cam, and the rotation of the aforementioned rotor that produces corresponding to the excitation according to aforementioned rotor electromagnetism coil in compression stroke, link the overrunning clutch between aforementioned relief cam and the aforementioned camshaft.

According to such formation, by in compression stroke to rotor electromagnetism coil excitation, link between relief cam and the camshaft corresponding with overrunning clutch, on the relief cam that together rotates with camshaft, the 2nd contacting part is by sliding contact, exhaust valve or intake valve are opened, and corresponding to the compression pressure that extracts motor, can improve the startability of motor.And the electromagnetic force brought into play of rotor electromagnetism coil, so long as for making overrunning clutch be the transferring power state, and rotor rotation is got final product, can also make rotor electromagnetism coil is more small-sized object, in addition, because on the roller of rotor electromagnetism coil, relief cam is wholely set, so do not need original necessary connect mechanism etc.And overrunning clutch is the transferring power state just in compression stroke, does not need sensor etc. just can control the time of the compression pressure of extraction motor.

In addition, the described invention of second technological scheme, on the formation of the described invention of above-mentioned first technological scheme, it is characterized in that, aforementioned overrunning clutch has: be configured between aforementioned camshaft and the relief cam, on coaxial, center in the camshaft, be provided with and cross in it, the roller holding member of the ring-type of the retaining hole between the outer circumferential face, with along with the place ahead to the sense of rotation of aforementioned camshaft, has plane of inclination for the foreign side position that makes its radial direction that becomes camshaft, be arranged on relief cam interior week in conjunction with recess, and can combine with aforementioned plane of inclination from the rear side of the sense of rotation of aforementioned camshaft, a part is contained in aforementioned in conjunction with recess, rotation freely remains on the roller on the aforementioned retaining hole, and contact in compression stroke with the projection of the aforementioned roller that begins in interior week from aforementioned roller holding member, this roller is sent in conjunction with the recess thruster to aforementioned, be arranged on the pushing teat of the periphery of aforementioned camshaft, and with the same direction of the sense of rotation of aforementioned camshaft, to aforementioned relief cam loading spring power, be arranged on the clutch spring between aforementioned roller holding member and the aforementioned relief cam; It constitutes aforementioned rotor electromagnetism coil, when its excitation, and the spring force of opposing aforementioned clutch spring, the electromagnetic force that effect makes aforementioned relief cam and roller rotate to the opposite direction with the sense of rotation of aforementioned camshaft.

Formation according to so described invention of second technological scheme, in the erasing state of rotor electromagnetism coil, rotation corresponding to camshaft, even roller is pushed at the pushing teat, because relief cam by clutch spring, is endowed the elastic force to sense of rotation the place ahead of camshaft, so roller does not contact with inclined-plane in conjunction with recess, can freely rotate, overrunning clutch keeps cutting off the state of the transmission of power between relief cam and the camshaft always.Therefore, the rotation of relief cam and camshaft is irrelevant, and is static always, because the 1st contacting part and valve cam sliding contact, exhaust valve or intake valve carry out on-off action by the acting characteristic corresponding to the cam curve of valve cam.On the one hand, in compression stroke, if to rotor electromagnetism coil excitation, the spring force of opposing clutch spring, rotor and relief cam are to the counter-rotation of the sense of rotation of camshaft, the roller that is pushed by the pushing teat of camshaft is clamped between the inclined-plane and aforementioned pushing teat in conjunction with recess, the rotational power of camshaft is delivered to relief cam, so by the 2nd contacting part and relief cam sliding contact, exhaust valve or intake valve are opened in compression stroke, can when engine start, extract the compression pressure of motor.And, as long as rotor electromagnetism coil is the spring force of opposing clutch spring, only performance makes rotor and relief cam get final product to the electromagnetic force of the counter-rotation of the sense of rotation of camshaft, can also make the further miniaturization of rotor electromagnetism coil, and, rotor and relief cam are diminished to the angle of the counter-rotation of the sense of rotation of camshaft get final product, can also simplify the structure of rotor electromagnetism coil.

The described invention of the 3rd technological scheme, on the formation of the described invention of above-mentioned second technological scheme, it is characterized in that, the stator of aforementioned rotor electromagnetism coil keeps by the stator retainer that is fixed in cylinder cap, block is arranged on the aforementioned roller holding member, the a pair of restriction face that can contact with the aforementioned block of the slewing area that should limit aforementioned roller holding member, position in the circumferencial direction devices spaced apart of camshaft, be formed on the stator former retainer, between aforementioned roller holding member and stator former retainer, be provided with aforementioned roller holding member to giving the return spring of elastic force with the opposite direction of the sense of rotation of aforementioned camshaft.According to relevant formation, the co-rotational fixed angle of roller holding member and camshaft within the specific limits, overrunning clutch is also corresponding to the rotation of roller holding member in aforementioned certain limit, cut off the transmission of power between relief cam and the camshaft, make roller holding member and relief cam be returned to original position by return spring, prepare during for following engine start, relief cam and roller holding member can positively be returned to initial position.

Have again, the described invention of the 4th technological scheme on the formation of the described invention of above-mentioned the 3rd technological scheme, is characterized in that, outstanding on the aforementioned roller holding member and on the aforementioned block that is provided with, O shape is installed encircles for contact with aforementioned two restriction faces to its radial direction foreign side.According to relevant formation, can do one's utmost to suppress the noise that produces owing to impact to the restriction face of block.

Description of drawings

Fig. 1 is the longitudinal section of the significant points of motor.

Fig. 2 is the 2-2 line sectional view of Fig. 1.

Fig. 3 is the 3-3 line sectional view of Fig. 1.

Fig. 4 is the expanded view at position shown in 4 arrows of Fig. 1.

Fig. 5 is the 5-5 line sectional view of Fig. 4.

Fig. 6 is the 6-6 line sectional view of Fig. 4.

Fig. 7 is the 7-7 line sectional view of Fig. 4.

Fig. 8 is the corresponding sectional view of Fig. 7 with the operating state that is used for illustrating successively rotor electromagnetism coil.

Fig. 9 is and the corresponding sectional view of Fig. 6 under the establishment initial state of overrunning clutch.

Figure 10 be with based on the corresponding sectional view of Fig. 6 under the unlatching initial state of the exhaust valve of relief cam.

Figure 11 be with based on the corresponding sectional view of Fig. 6 under the unlatching done state of the exhaust valve of relief cam.

Figure 12 is and the corresponding sectional view of Fig. 6 that is returned at roller holding member and relief cam under the original state.

Figure 13 is used for explanation before compression stroke, and the decompression when making engine start begins the figure in period.

Figure 14 is used to illustrate that in compression stroke midway the decompression when making engine start begins the figure in period.

Embodiment

Below, the one embodiment of the present of invention shown in illustrate embodiments of the present invention with reference to the accompanying drawings.

Fig. 1-Figure 14 is expression one embodiment of the present of invention, Fig. 1 is the longitudinal section of the significant points of motor, Fig. 2 is the 2-2 line sectional view of Fig. 1, Fig. 3 is the 3-3 line sectional view of Fig. 1, Fig. 4 is the expanded view at position shown in 4 arrows of Fig. 1, Fig. 5 is the 5-5 line sectional view of Fig. 4, Fig. 6 is the 6-6 line sectional view of Fig. 4, Fig. 7 is the 7-7 line sectional view of Fig. 4, Fig. 8 is the corresponding sectional view of Fig. 7 with the operating state that is used for illustrating successively rotor electromagnetism coil, Fig. 9 is and the corresponding sectional view of Fig. 6 under the establishment initial state of overrunning clutch, Figure 10 be with based on the corresponding sectional view of Fig. 6 under the unlatching initial state of the exhaust valve of relief cam, Figure 11 be with based on the corresponding sectional view of Fig. 6 under the unlatching done state of the exhaust valve of relief cam, Figure 12 is and the corresponding sectional view of Fig. 6 that is returned at roller holding member and relief cam under the original state, Figure 13 is used for explanation before compression stroke, decompression when making engine start begins the figure in period, Figure 14 is used to illustrate that in compression stroke midway the decompression when making engine start begins the figure in period.

At first, in Fig. 1 and Fig. 2, this motor for example is a single-cylinder engine, and its engine body 14 has cylinder body 16 that combines with crankcase 15 and the cylinder cap 17 that combines with this cylinder body 16.In the cylinder barrel 18 on being arranged at cylinder body 16, piston 19 is chimeric slidably, faces the firing chamber 20 at the top of this piston 19, forms between cylinder body 16 and cylinder cap 17.In addition, form valve cage 21 on the top of cylinder cap 17.

On cylinder cap 17, setting faces the inlet valve port 22 of the end face of firing chamber 20, with be communicated with this inlet valve port 22, suction port 24 at a lateral opening of cylinder cap 17, and face the exhaust valve port 23 of the end face of previous combustion chamber 20, be communicated with this exhaust valve port 23 in addition, at the relief opening 25 of the another side of cylinder cap 17 opening, simultaneously, the spark plug 26 that faces firing chamber 20 is installed.

On cylinder cap 17, guide cylinder 29 that the chimeric on-off action that is fixed with the intake valve 27 that can open and close inlet valve port 22 leads and the guide cylinder 30 that the on-off action of the exhaust valve 28 that can open and close exhaust valve port 23 is led.Between the baffle plate 31 and cylinder cap 17 that are provided with to the upper end of the side-prominent intake valve 27 of valve cage 21 from guide cylinder 29, it is the valve spring 33 that closing direction is given elastic force upward that compression is provided with intake valve 27.In addition, between the baffle plate 32 and cylinder cap 17 that are provided with to the upper end of the side-prominent exhaust valve 28 of valve cage 21 from guide cylinder 30, it is the valve spring 34 that closing direction is given elastic force upward that compression is provided with exhaust valve 28.

Comprehensively with reference to Fig. 3, in valve cage 21, accommodate the valve gear 35 of driven for opening and closing intake valve 27 and exhaust valve 28, this valve gear 35 has rotation and freely is supported on camshaft 36 on the cylinder cap 17, with the axis parallel with this camshaft 36 arranged, is being supported in the air inlet side on the cylinder cap 17 and the pitman arm shaft 37,38 of exhaust side above the camshaft 36, and the air inlet side rocking arm 39 that supports swingably by air inlet side pitman arm shaft 37, and the exhaust side Rocker arm 40 that supports swingably by exhaust side rocking arm 38 as the cam driven device.

Camshaft 36 has and the parallel axis of bent axle (not having diagram), and this bent axle links by connecting rod 41 and piston 19, and in 2 positions of axle direction devices spaced apart, by ball bearing 42,43, rotation freely is supported on the cylinder cap 17.The cam chain chamber 44 of an end that faces this camshaft 36 is forming between cylinder cap 17 through cylinder body 16 from crankcase 15, and in cam chain chamber 44, driven sprocket 45 is fixed on an end of camshaft 36.And by being wrapped in the cam chain 46 on this driven sprocket 45, the reduction speed ratio with 1/2 is delivered to camshaft 36 from the rotating power of aforementioned bent axle.

On this camshaft 36, be provided with air inlet side cam 47 corresponding and the exhaust side cams 48 as valve cam corresponding with exhaust side Rocker arm 40 with air inlet side rocking arm 39.

But, on cylinder cap 17, being used for can be to the assembling of the cylinder cap 17 of aforementioned camshaft 36, to ball bearing 42, the assembling of 43 cylinder cap 17 and to the opening portion 49 of assembling of the driven sprocket 45 of an end of camshaft 36 etc., be provided with on coaxial with camshaft 36, this opening portion 49 is by cover 50 sealings.And, distolateral at another of camshaft 36, have the bolt 51 of the fastening head 51a that combines with the outside of cylinder cap 17, coaxial with camshaft 36, be interspersed in this camshaft 36 and cylinder cap 17, be anchored on aforementioned cover parts 50 by this bolt 51 is screwed togather, and aforementioned cover parts 50 are fixed in cylinder cap 17.

Aforementioned air inlet side and exhaust side pitman arm shaft 37,38 have the axis parallel with camshaft 36, be fitted to cylinder cap 17 from aforementioned opening portion 49 sides, be incorporated into the outer end, outer ring of ball bearing 42, this outer ring is held on and cylinder cap 17 between board 52, also be incorporated into aforementioned air inlet side and exhaust side pitman arm shaft 37,38, be attached to cylinder cap 17, stop the pitman arm shaft 37,38 of air inlet side and exhaust side to move in view of the above, thereby be installed on the cylinder cap 17 axial.

On an end of the air inlet side rocking arm 39 that can swingingly support by air inlet side pitman arm shaft 37, with the tappet screw 53 of the last end in contact of intake valve 27 as regulating the advance and retreat position and being screwed togather, on the other end of air inlet side rocking arm 39, axle is supported with the roller 54 that rolls and contact with air inlet side cam 47.That is, air inlet side rocking arm 39 is corresponding to the rotation of camshaft 36, and the acting characteristic of the cam curve by corresponding air inlet side cam 47 is carried out the wobbling action of driven for opening and closing intake valve 27.

On an end of the exhaust side Rocker arm 40 that can swingingly support by exhaust side pitman arm shaft 38, with the tappet screw 55 of the last end in contact of exhaust valve 28 as regulating the advance and retreat position and being screwed togather.In addition, on the other end of exhaust side Rocker arm 40, be supported with as rolling in the roller 56 of the 1st contacting part that contact, on this roller 56 with exhaust side cams 48 at axle, at its axle direction, be provided with by one is outstanding as the contact teat 57 of the 2nd contacting part of adjacency.

In addition, on cylinder cap 17, be provided with the assembling that is used to carry out to the air inlet side rocking arm 39 of air inlet side pitman arm shaft 37, to the opening portion 58 of the assembling of the baffle plate 31 of the upper end of intake valve 27 and assembling of the valve spring 33 between baffle plate 31 and cylinder cap 17 etc., and be used to carry out to the exhaust side Rocker arm 40 of exhaust side pitman arm shaft 38 assembling, to the opening portion 59 of the installation of the baffle plate 32 of the upper end of exhaust valve 28 and assembling of the valve spring 34 between baffle plate 32 and cylinder cap 17 etc., these opening portions 58,59 are closed by the cover 60,61 that is combined on the cylinder cap 17.

In Fig. 4-Fig. 6, with exhaust side cams 48 adjoining positions on, compression stroke can with the relief cam 65 that contacts teat 57 sliding contacts of aforementioned exhaust side Rocker arm 40, coaxial around camshaft 36 and disposing, on cylinder cap 17, the stator 69 of the rotor electromagnetism coil 66 of the rotor that is wholely set 68 that aforementioned relief cam 65 is had is supported, between camshaft 36 and relief cam 65, is provided with overrunning clutch 67.And relief cam 65 and overrunning clutch 67 together are assembled on the cylinder cap 17 from aforementioned opening portion 58,59 with camshaft 36 after being installed to aforementioned camshaft 36.

Relief cam 65 is on the part of circumferencial direction, has ridge 65a at radial direction foreign side protuberance, form ring-type around camshaft 36, in compression stroke, aforementioned roller 56 can sliding contact exhaust side cams 48 the state of the 48a of basis circle portion (with reference to Fig. 6) under, when aforementioned ridge 65a sliding contact contacts teat 57, aforementioned roller 56 is floated 0 swing of exhaust side Rocker arm 4 from the aforementioned basis circle 48a of portion.

Overrunning clutch 67 is configured between camshaft 36 and the relief cam 65, coaxial in the camshaft 36, have: be provided with and cross in it, the roller holding member 72 of the ring-type of the retaining hole 71 between the outer circumferential face, with along with towards the place ahead along the sense of rotation 77 of camshaft 36, has plane of inclination 73a for the foreign side position that makes its radial direction that becomes camshaft 36, be arranged on relief cam 65 interior week in conjunction with recess 73, and can combine with aforementioned plane of inclination 73a from rear side along the sense of rotation 77 of camshaft 36, a part is contained in aforementioned in conjunction with recess 73, rotation freely remains on the roller 74 on the aforementioned retaining hole 71, and contact in compression stroke with projection from the aforementioned roller 74 of the interior week beginning of aforementioned roller holding member 72, this roller 74 is sent in conjunction with recess 73 thrusters to aforementioned, be arranged on the pushing teat 75 of the periphery of aforementioned camshaft 36, and with the same direction of the sense of rotation 77 of aforementioned camshaft 36, performance is arranged on the clutch spring 76 between aforementioned roller holding member 72 and the aforementioned relief cam 65 to the spring force that aforementioned relief cam 65 loads.

Aforementioned pushing teat 75 is in the part corresponding with the retaining hole 71 of aforementioned roller holding member 72, by the groove 78 of the part remove its circumferencial direction is set, remove residual part behind its groove 78 as forming towards the outstanding pushing teat 75 of radial direction foreign side on the periphery of camshaft 36.In addition, from aforementioned retaining hole 71, in the position of circumferencial direction devices spaced apart, on roller holding member 72, outstanding being provided with the outstanding wrist 72a of the Zhou Dynasty of radial direction foreign side from it outside, on the interior week of relief cam 65, what this wrist 72a was held in setting holds recess 79.And clutch spring 76 compressions are arranged between aforementioned wrist 72a and the relief cam 65, are housed inside and hold recess 79.

In such overrunning clutch 67, rotation corresponding to camshaft 36, in compression stroke, pushing teat 75 as shown in Figure 6, even reach the position that pushes roller 74, do not act under the state of relief cam 65 at electromagnetic attraction from rotor electromagnetism coil 66, because relief cam 65 is by clutch spring 76, give elastic force to the place ahead along the sense of rotation 77 of camshaft 36, so roller 74 does not contact with plane of inclination 73a in conjunction with recess 73, can freely rotate, thereby can be in the state that cuts off the transmission of power between relief cam 65 and the camshaft 36 always.Therefore, the irrelevant to rotation of relief cam 65 and camshaft 36, static always, by roller 56 sliding contact exhaust side cams 48, exhaust valve 28 carries out on-off action by the acting characteristic corresponding to the cam curve of exhaust side cams 48.

On the one hand, if to rotor electromagnetism coil 66 excitations, the spring force of opposing clutch spring 76, relief cam 65 is to the counter-rotation of the sense of rotation 77 of camshaft 36, the roller 74 that is pushed by the pushing teat 75 of camshaft 36 is clamped between the plane of inclination 73a and pushing teat 75 in conjunction with recess 73, the rotational power of camshaft 36 is delivered to relief cam 65, because contact teat 57 and relief cam 65 sliding contacts, exhaust valve 28 is opened in compression stroke, in view of the above, just can when engine start, extract the compression pressure of motor.

Rotor electromagnetism coil 66 is when its excitation, the spring force of opposing clutch spring 76, performance makes relief cam 65 constitute to the electromagnetic force of the counter-rotation of the sense of rotation 77 of camshaft 36, have coaxial around camshaft 36 rotor 68 and around this rotor 68 and the stator 69 of fixed configurations, aforementioned relief cam 65 is wholely set on rotor 68.

In Fig. 7, stator 69 is by iron core 80 and be wound in bobbin 81, the coil 82 that is contained in aforementioned unshakable in one's determination 80 constitutes, this iron core 80 has the shape of cross section of the summary U word shape that square side is opened in the radial direction, coaxial in the camshaft 36, separate for example both sides of 4 positions, equally spaced a plurality of position at circumferencial direction, each one outstandingly over the ground is provided with side- prominent teat 80a, 80a in the radial direction ..., keep unshakable in one's determination 80 stator retainer 83 and cylinder cap 17 bindings.

Rotor 68 is between stator 69 and camshaft 36, form coaxial ring-type around this camshaft 36, the teat 80a, the 80a that are had with stator former 69 ... identical teat 68a, the 68a of group number ... outstanding to radial direction foreign side, separate on equally spaced a plurality of position at the circumferencial direction of rotor 68 and to be highlighted setting.

In the holding state of such rotor electromagnetism coil 66, shown in Fig. 8 (a), make each the teat 68a that is had along rotor 68 ... in the part of rear side of sense of rotation 77 of camshaft 36, with edge each teat 80a in stator 69 ... in the part of front side of aforementioned sense of rotation 77 corresponding, thereby the relative rotation position of decision stator 69 and rotor 68.

And, if to coil 82 energising excitations, then at each teat 68a of rotor 68 ... dash, shown in the solid arrow of Fig. 8 (b), the electromagnetic attraction effect is in rotor 68, as all, produce as with the torsion of direction shown in the sense of rotation 77 reciprocal arrows 84 of camshaft 36.Because this torsion, by the direction rotation of rotor 68 shown in arrow 84, overrunning clutch 67 is opening state, the rotational power of camshaft 36 is delivered to rotor 68 by overrunning clutch 67, if rotor 68 and camshaft 36 together turn to the position shown in Fig. 8 (c), for example rotates 26.5 degree, then at each teat 68a of rotor 68 ... in, shown in the solid line arrow, the electromagnetic attraction effect of opposition side mutually acts on rotor 68 all torsion and is [0].

The action of the overrunning clutch 67 by being opening state, rotor 68 together rotates with camshaft 36, turning to the position shown in Fig. 8 (d), for example 55 when spending, at each teat 68a of rotor 68 ... in, shown in the solid line arrow, generation to the sense of rotation 77 unidirectional torsion of camshaft 36, in rotor 68 is all, also act on camshaft 36 unidirectional torsion, in view of the above, aforementioned overrunning clutch 67 becomes closed condition.

But, on aforementioned roller holding member 72, be wholely set outstanding block 72b to its radial direction foreign side.On the one hand, at the stator 69 that keeps rotor electromagnetism coil 66, be fixed on the stator retainer 83 on the cylinder cap 17 of engine body 14, the a pair of restriction face 85,86 that can contact with the block 72b of the slewing area that should limit roller holding member 72, position in the circumferencial direction devices spaced apart of camshaft 36, be formed on the stator former retainer 83, at the front end of block 72b, send out contact for making aforementioned two restriction faces, 85,86 bullets, O shape ring 87 is installed.

In addition, between roller holding member 72 and stator retainer 83, be provided with and give return spring 88 to the opposite direction elastic force of the sense of rotation 77 of camshaft 36 to roller holding member 72, cut off under the state of power at overrunning clutch 67, by the spring force of return spring 88, aforementioned block 72b is pushed to restriction face 85 sides.

Below, on one side with reference to Fig. 9-Figure 14, the effect with regard to this embodiment on one side describes, and when engine start, in its compression stroke, forces to make exhaust valve 28 to be opened, when extracting the compression pressure of motor, to rotor electromagnetism coil 66 excitations.So, as shown in Figure 9, if the spring force of opposing clutch spring 76, relief cam 65 is to the counter-rotation of the sense of rotation 77 of camshaft 36, in compression stroke, the pushing teat 75 of camshaft 36 pushes rollers 74, then this roller 74 clamping between in conjunction with the plane of inclination 73a of recess 73 and pushing teat 75, and the rotating power of camshaft 36 is delivered to relief cam 65.In view of the above, camshaft 36, roller holding member 72 and relief cam 65 are at the state from Fig. 9, when for example becoming the state of the Figure 10 that rotates 20 degree, the ridge 65a of contact teat 57 sliding contact relief cams 65, for roller 56 is floated from the 48a of basis circle portion of exhaust side cams 48,0 swing of exhaust side Rocker arm 4, exhaust valve 28 carries out breakdown action.

Camshaft 36 is further rotated, when the state of Fig. 9 rotation 50 is spent, as shown in figure 11, contact teat 57 is in the position with the descending part sliding contact of ridge 65a in relief cam 65, the swing of exhaust side Rocker arm 40 finishes, and exhaust valve 28 becomes closed condition.Thereafter, as shown in figure 12, if camshaft 36 is further rotated, block 72b contacts with the restriction face 86 of stator retainer 83, then stops the rotation to the sense of rotation 77 of roller holding member 72.In view of the above, no matter camshaft 36 is relief cam 65 and roller holding member 72 and rotate, the rotor 68 of rotor electromagnetism coil 66 and relief cam 65 are based on inertia, perhaps under the situation of the excited state that continues rotor electromagnetism coil 66, torsion based on rotor electromagnetism coil 66 also acts on, and for example rotates about 5 degree to sense of rotation 77.Therefore, removed the clamping at the plane of inclination of roller 74 73a and 75 of teats of pushing, overrunning clutch 67 becomes the cut-out dynamic regime.

Like this, pass through rotor electromagnetism coil 66 excitations in compression stroke, link between relief cam 65 and the camshaft 36 corresponding to overrunning clutch 67, by contacting the relief cam 65 that teat 57 sliding contacts and camshaft 36 together rotate, exhaust valve 28 is opened, corresponding to the compression pressure that extracts motor, can improve the startability of motor.And, the electromagnetic force that rotor electromagnetism coil 66 is brought into play, so long as can make overrunning clutch 67 be the transferring power state, and the power that rotor 68 is rotated gets final product, can make rotor electromagnetism coil 66 become more small-sized article, in addition, because relief cam 65 is wholely set on the rotor 68 of rotor electromagnetism coil 66, so do not need original necessary bindiny mechanism etc.And, make overrunning clutch 67 be the transferring power state only in compression stroke, do not need sensor etc., just can control the time of the compression pressure that extracts motor.

In addition, overrunning clutch 67 is at the spring force of opposing clutch spring 76, rotor 68 and relief cam 65 are when the counter-rotation of the sense of rotation 77 of camshaft 36, the roller 74 that pushes by the pushing teat 75 of camshaft 36 clamping between in conjunction with the plane of inclination 73a of recess 73 and pushing teat 75, the rotating power of camshaft 36 is delivered to relief cam 65 and constitutes, the spring force of rotor electromagnetism coil 66 opposing clutch springs 76, as long as performance makes rotor 68 and relief cam 65 to the electromagnetic force of the counter-rotation of the sense of rotation 77 of camshaft 36, can make the 66 further miniaturizations of rotor electromagnetism coil.

And, rotor 68 and relief cam 65 are diminished to the angle of the counter-rotation of the sense of rotation 77 of camshaft 36 get final product, can simplify the structure of rotor electromagnetism coil 66.Promptly, by have unshakable in one's determination 80 and be wound in bobbin 81, the simple structure that is contained in the coil 82 in aforementioned unshakable in one's determination 80 constitutes stator 69, this iron core 80 separates the both sides of equally spaced a plurality of positions at circumferencial direction, each one outstandingly over the ground is provided with outstanding teat 80a, the 80a in side in the radial direction ... rotor 68 also is to make teat 68a, 68a ... outstanding to radial direction foreign side, separate at circumferencial direction and to be highlighted the simple structure of setting on equally spaced a plurality of position and to constitute.

In addition, the stator 69 of rotor electromagnetism coil 66, keep by the stator retainer on the cylinder cap 17 that is fixed in engine body 14 83, the a pair of restriction face 85,86 that can contact with the block 72b on being arranged on roller holding member 72, on the position of the circumferencial direction devices spaced apart of the camshaft 36 of the slewing area that should limit roller holding member 72, be formed on the stator retainer 83, between roller holding member 72 and stator retainer 83, return spring 88 from elastic force to the opposite direction of the sense of rotation 77 of camshaft 36 that roller holding member 72 is given is set.

Therefore, roller holding member 72 fixes on certain limit with the angle that camshaft 36 together rotates, overrunning clutch 67 is also corresponding to the rotation in aforementioned certain limit of roller holding member 72, cut off the transmission of power between relief cam 65 and the camshaft 36, as shown in figure 12, by return spring 88, roller holding member 72 and relief cam 65 are returned to original position, prepare during for following engine start, relief cam 65 and roller holding member 72 can positively be returned to initial position.

Have again, block 72b is arranged on the roller holding member 72 highlightedly to its radial direction foreign side, owing to be to send out with two restriction faces, 85,86 bullets of stator holding member 83 to contact, and O shape ring 87 has been installed on the block 72b, so can do one's utmost to suppress because the noise that the impact of the restriction face 85,86 of block 72b is produced.

But, before compression stroke, when engine start, as shown in figure 13, from decompression beginning set angle, promptly push teat 75 and begin decompression with the crankshaft angles that roller 74 begins to contact, with respect in non-decompression state, chamber pressure increase shown in dotted line is shown in solid line, by chamber pressure is reduced, can improve the startability of motor.To this, in compression stroke midway, when engine start, as shown in figure 14, in the compression stroke after surpassing decompression beginning set angle, by contact, and begin decompression, with respect under non-decompression state to the roller 74 that pushes teat 75, chamber pressure increase shown in dotted line, shown in solid line, reduce by making chamber pressure, can improve the startability of motor.

Above, embodiments of the invention have been described, the present invention is not limited to the foregoing description, only otherwise break away from the present invention who is put down in writing in the scope of claim, just can carry out various design alterations.

For example, the present invention also go for by with air inlet side cam 47 in abutting connection with the relief cam 65 that is set, make the decompressor of intake valve 27 enforced openings in compression stroke.

According to the described invention of first technological scheme as above, by in compression stroke to rotor electromagnetism coil excitation, link between relief cam and the camshaft corresponding with overrunning clutch, exhaust valve or intake valve are opened, correspondence extracts the compression pressure of motor, can improve the startability of motor.And the electromagnetic force brought into play of rotor electromagnetism coil, so long as for making overrunning clutch be the transferring power state, and rotor rotation is got final product, can also make rotor electromagnetism coil is more small-sized object, in addition, because on the roller of rotor electromagnetism coil, relief cam is wholely set, so do not need original necessary binding to connect structure etc.And overrunning clutch is the transferring power state just in compression stroke, does not need sensor etc. just can control the time of the compression pressure of extraction motor.

In addition, according to the described invention of second technological scheme, as long as rotor electromagnetism coil is the spring force of opposing clutch spring, performance makes rotor and relief cam get final product to the electromagnetic force of the counter-rotation of the sense of rotation of camshaft, can also make the further miniaturization of rotor electromagnetism coil, and, rotor and relief cam are diminished to the angle of the counter-rotation of the sense of rotation of camshaft get final product, can also simplify the structure of rotor electromagnetism coil.

According to the described invention of the 3rd technological scheme, the co-rotational fixed angle of roller holding member and camshaft within the specific limits, overrunning clutch is also corresponding to the rotation of roller holding member in aforementioned certain limit, cut off the transmission of power between relief cam and the camshaft, make roller holding member and relief cam be returned to original position by return spring, prepare during for following engine start, relief cam and roller holding member can positively be returned to initial position.

Have again,, can suppress the noise that produces owing to impact with doing one's utmost the restriction face of block according to the described invention of the 4th technological scheme.

Claims (4)

1. the decompressor of a motor, it is characterized in that, possessing has: with exhaust valve (28) or intake valve interlock, when linking, be provided with the 1st and the 2nd contacting part (56,57) cam follower (40), with the camshaft (36) that is provided with the valve cam (48) of described the 1st contacting part (56) sliding contact, and have and the rotor electromagnetism coil (66) of this camshaft (36) around the rotary rotor of same axis (68), and can be with described the 2nd contacting part (57) sliding contact in compression stroke, be wholely set the relief cam (65) on described rotor (68), and the rotation of the described rotor (68) that produces corresponding to the excitation according to described rotor electromagnetism coil (66) in compression stroke, link the overrunning clutch (67) between described relief cam (65) and the described camshaft (36).

2. the decompressor of motor as claimed in claim 1, it is characterized in that, described overrunning clutch (67) has: be configured between described camshaft (36) and the relief cam (65), on coaxial, center in the camshaft (36), be provided with and cross in it, the roller holding member (72) of the ring-type of the retaining hole between the outer circumferential face (71), with along with the place ahead towards the sense of rotation (77) of described camshaft (36), has plane of inclination (73a) for the foreign side position that makes its radial direction that becomes camshaft (36), be arranged on relief cam (65) interior week in conjunction with recess (73), and can combine with described plane of inclination (73a) from the rear side of the sense of rotation (77) of described camshaft (36), a part is contained in described in conjunction with recess (73), rotation freely remains on the roller (74) on the described retaining hole (71), and contact in compression stroke with projection from the described roller (74) of the interior week beginning of described roller holding member (72), this roller (74) is sent in conjunction with recess (73) thruster to described, be arranged on the pushing teat (75) of the periphery of described camshaft (36), and with the same direction of the sense of rotation (77) of described camshaft (36), to described relief cam (65) loading spring power, be arranged on the clutch spring (76) between described roller holding member (72) and the described relief cam (65); It constitutes described rotor electromagnetism coil (66), when its excitation, resist the spring force of described clutch spring (76), the electromagnetic force that effect makes described relief cam (65) and roller (68) rotate to the opposite direction with the sense of rotation (77) of described camshaft (36).

3. the decompressor of motor as claimed in claim 2, it is characterized in that, the stator (69) of described rotor electromagnetism coil (66) keeps by the stator retainer (83) that is fixed in cylinder cap (17), block (72b) is arranged on the described roller holding member (72), the a pair of restriction face (85 that can contact with the described block (72b) of the slewing area that should limit described roller holding member (72), 86), circumferencial direction in camshaft (36), the position of devices spaced apart, be formed on the described stator retainer (83), between described roller holding member (72) and described stator retainer (83), be provided with described roller holding member (72) to giving the return spring (88) of elastic force with the opposite direction of the sense of rotation (77) of described camshaft (36).

4. the decompressor of motor as claimed in claim 3, it is characterized in that, go up at described roller holding member (72), outstanding to its radial direction foreign side and on the described block (72b) that is provided with, O shape be installed encircle (87) for contact with described two restriction faces (85,86).

Images