CN204113366U

CN204113366U - For limiting the fixture of the angular displacement of valve tappet

Info

Publication number: CN204113366U
Application number: CN201290001061.4U
Authority: CN
Inventors: S·瑞姆拉; S·罗曼
Original assignee: Caterpillar Inc
Current assignee: Caterpillar Inc
Priority date: 2011-12-14
Filing date: 2012-11-19
Publication date: 2015-01-21
Anticipated expiration: 2022-11-19
Also published as: WO2013089974A1; US20130152886A1

Abstract

The utility model discloses a kind of fixture (92) of the angular displacement for limiting valve tappet, comprising single type metal master (93), single type metal master (93) has support (94) and the suspension bracket be connected (96).Fixture (92) is configured to be connected to form the position that tappet assembly (30) changes the valve (36) in internal-combustion engine (10) with valve tappet (42).Support (94) can be C shape, and suspension bracket (96) can be U-shaped.Single type metal master (93) also comprises and resistance to wears external frame and be transitioned into the first fillet and second fillet (114) of suspension bracket (96) from support (94), spreads for limiting rest position in the angular displacement limited by the contact between suspension bracket (96) and the wall section (19) of cylinder body (14) stress caused in fixture (92).

Description

For limiting the fixture of the angular displacement of valve tappet

Technical field

The utility model relates generally to the valve tappet for internal-combustion engine, more specifically, relates to by suppressing the fatigue failure of the displacement restriction fixture for valve tappet to extend engine on working life.

Background technique

In internal-combustion engine, use valve tappet to convert the rotary motion of engine cam to straight line motion, for controlling the position of gas exchange valve.Typical design comprises tappet body, and this tappet body couples mutually with push rod, and this push rod is configured to the rocking arm activating one or more gas exchange valve.Tappet body comprises the roller of locating contiguously with engine cam, slides in the tappet bore causing valve tappet to be formed in motor body to make the rotation of engine cam.The slip adjustment push rod of valve tappet, it makes again rocking arm move in known manner.

Described roller can be substantial cylindrical and with the exterior surface of described cam, make ideal interface between this roller and this cam outer face be linear substantially.Duration of work within the engine, by the rotation of valve tappet in tappet bore, valve tappet may misplace with cam.The reason of this dislocation seems to change between motor.Even if engine design identical on the surface can show the problem of misalignment on its different valve tappets in the length of life of motor.Even if in identical motor, some valve tappets trend towards rotating more than other valve tappet or being different from other valve tappet, which increase complexity.

In these years, proposed various strategy to rotate to limit valve tappet.A technology adopts the guiding mechanism coupled with valve tappet.Authorize the U. S. Patent the 5th, 3,886 of Weber, No. 808 propose a kind of like this design.In the patent of Weber, described guiding mechanism comprises the arm of vertically disposed leg and a pair cylindrical shape, and described leg is for being landed in the slit that formed in valve tappet, and described arm is landed in the peripheral groove that is also formed in valve tappet.The hook being connected to leg is arranged in the hole of the cylinder body of motor, and this obviously prevents guiding mechanism and valve tappet rotation.

Have developed the modification in the basic guide design of instructing at Weber in recent years.But along with the continuous advancement of technology, engine design, dutycycle and performance characteristics change, the nature and extent that valve tappet rotates and this consequence within the engine change too.Perhaps be that more gratifying restrictions or the strategy otherwise controlling valve tappet rotation become inapplicable in the past.As many engineered solution, these strategies are just imperfect in beginning.Inefficacy or the damage of valve tappet and associated component may need expensive maintenance or repairing, and shorten the working life of motor.Rotate reason to valve tappet be short in understanding and make to become complicated and unpredictable in the pursuit of the scheme of this technical field together with avoiding redesigning the expectation of motor.

Summary of the invention

In one aspect, a kind of method extending internal-combustion engine working life, comprises and moment of torsion is passed to fixture from rotating into the valve tappet misplaced with cam; Fixture comprises the support that the tappet body around valve tappet engages and the suspension bracket extending into the otch formed in tappet body; Described method also comprises passes through transmitted moment of torsion, simultaneously rotary clamp and valve tappet, and stops the rotation of valve tappet and fixture at stop position, stop position be by the wall section of the cylinder body of suspension bracket and internal-combustion engine between contact limited; Described method also comprises the fatigue failure suppressing fixture, and this is at least in part by spreading via the fillet being transitioned into suspension bracket from support at stop position the stress caused fixture.

On the other hand, a kind of fixture of the angular displacement for limiting valve tappet, the cylinder holes that the cylinder body that described valve tappet is arranged in internal-combustion engine is formed, described fixture comprises the single type metal master with support and suspension bracket, described single type metal master comprises the first jaw and the second relative jaw, and connect the base of the first jaw and the second jaw, so that support forms C shape in the first plane; Each in described first jaw and the second jaw comprises near-end and the free distal end of adjacent base; Described support also comprises the opening side formed by free distal end, for clamping support around valve tappet to form tappet assembly; Described suspension bracket is given prominence to from support on the direction perpendicular to described first plane, and has straight proximal part, and this straight proximal part is connected to base and can be arranged in the otch of formation in valve tappet rotatably to connect on it by fixture; Described suspension bracket also has perpendicular to the distal portions forming U-shaped in the second plane of the first plane, for being connected by the wall section of contiguous to tappet assembly and cylinder body tappet bore; Described single type metal master has the external frame that resistance to wears, the described external frame that resistance to wears be configured to towards and rotate the process of tappet assembly from the angular displacement restriction stop position limited by the contact between suspension bracket and wall section, suppress the interference between base and tappet bore; Described single type metal master also comprises the first fillet and the second fillet that are transitioned into straight proximal part from base, for the stress caused in angular displacement restriction stop position diffusion fixture.

In another, provide a kind of fixture of the angular displacement for limiting valve tappet, angular displacement is caused by engine dynamics between the spreadable life in internal-combustion engine at the assembly of valve tappet and fixture; Described fixture comprises the single type metal master with support and suspension bracket; Described support comprises the first jaw and the second relative jaw and the base being connected the first jaw and the second jaw, so that support forms C shape; Each in described first jaw and the second jaw comprises near-end and the free distal end of adjacent base; Described support also comprises the opening side formed by free distal end, so that separately free distal end comes enlarged openings side, for clamping described support around valve tappet to form assembly; Described suspension bracket is given prominence to from support, and has the distal portions forming U-shaped, for being connected by the wall section of contiguous to assembly and cylinder body tappet bore in internal-combustion engine; Described suspension bracket also has straight proximal part, is connected to base and is arranged in the otch that formed in valve tappet, to be rotatably connected thereto by fixture, by the angular displacement of the contact between suspension bracket and wall section at stop position restriction valve tappet; Described fixture also comprises component, and described component comprises shape and the thickness of single type metal master, for the stress that causes in response to rest position to suppress the fatigue failure of suspension bracket.

Accompanying drawing explanation

Fig. 1 is the partial cutaway schematic of the internal-combustion engine according to an embodiment;

Fig. 2 is the partial cutaway schematic of the part of the motor of Fig. 1;

Fig. 3 is the schematic diagram of the engine valve tappet assembly according to an embodiment;

Fig. 4 is the front view of the part engine valve tappet assembly of Fig. 3;

Fig. 5 is the schematic diagram of the engine valve tappet according to an embodiment;

Fig. 6 is the front view of the engine valve tappet of Fig. 5;

Fig. 7 is the rear view of the engine valve tappet of Fig. 5 and Fig. 6;

Fig. 8 is the top view of the engine valve tappet of Fig. 5-Fig. 7;

Fig. 9 is the bottom view of the engine valve tappet of Fig. 5-Fig. 8;

Figure 10 is the front schematic view of the engine valve tappet of Fig. 5-Fig. 9, compared with the shape of some feature of the engine valve tappet of Known designs;

Figure 11 is the schematic diagram of the angular displacement restriction fixture according to an embodiment;

Figure 12 is another schematic diagram of the fixture of Figure 11;

Figure 13 is the front view of the fixture of Figure 11 and Figure 12;

Figure 14 is the rear view of the fixture of Figure 11-Figure 13;

Figure 15 is the top view of the fixture of Figure 11-Figure 14;

Figure 16 is the bottom view of the fixture of Figure 11-Figure 15;

Figure 17 is the sectional view intercepted along the 17-17 line of Figure 15;

Figure 18 is the sectional view intercepted along the 18-18 line of Figure 15;

Figure 19 is the schematic diagram of the fixture of Figure 11-Figure 18, the shape of some features of fixture compared with Known designs;

Figure 20 is the plan view of the engine valve tappet assembly be arranged in engine cylinder-body;

Figure 21 is the plan view of the engine valve tappet assembly be arranged in the cylinder body of motor.

Embodiment

With reference to figure 1, show the internal-combustion engine 10 according to an embodiment.Internal-combustion engine 10 can be compression ignition diesel engine.Motor 10 can comprise motor body 12, and this motor body 12 has cylinder body 14, and this cylinder body defines cylinder 16 and tappet bore 18.Piston 20 is reciprocating in cylinder 16, and is connected by piston rod 22 in a conventional manner with bent axle 24.Motor 10 also can comprise camshaft 26, and it can respond the rotation of bent axle 24 and rotate.In an illustrated embodiment, merely illustrate a cylinder and a tappet bore, but should be appreciated that, motor 10 will comprise multiple cylinder, multiple piston and multiple tappet bore in most of implementation.Motor 10 also can comprise valve tappet assembly 30, and it is positioned in tappet bore 18 at least in part.In the implementation strategy of practicality, two valve tappet assemblies can be associated with each in described multiple cylinder.Assembly 30 is configured to actuate push 32, and this push rod 32 couples mutually with the rocking arm 34 of the gas exchange valve 36 for motor 10.Two gas exchange valves 36 shown in figure, and intake valve or exhaust valve can be comprised, and be positioned at the cylinder cap 38 of motor body 12 at least partly.The cam 28 of camshaft 26 rotates together with camshaft 26, with moving assembly 30 in tappet bore 18.Understand as knowing further from following description, compared with traditional design, motor 10 can be life-saving and constructing uniquely.Observe, during internal-combustion engine is safeguarded, valve tappet assembly rotates and misplaces with cam, and it has less desirable and potential catastrophic effect.The utility model overcomes these shortcomings in available engine design, and is considered to the premature failure of the parts preventing tappet assembly 30, makes exceed the working life of motor 10, as further described herein in its working life.

Assembly 30 can comprise valve tappet 42 and the angular displacement that is coupled with valve tappet 42 limits fixture 92.Valve tappet 42 can have near-end 44, far-end 46 and and be positioned at far-end 46 and be configured to contact the tappet roller 48 of cam 28.Fixture 92 can comprise support 94 and suspension bracket 96, and support 94 engages with valve tappet 42, and described suspension bracket 96 is connected to support 94 and by the part of valve tappet assembly 30 with cylinder body 14, the wall portion phase-splitting be especially described below couples.Now also with reference to figure 2, wherein illustrate in greater detail tappet assembly 30.Support 94 is shown as being coupled to valve tappet 42, and suspension bracket 96 and the wall section 19 of cylinder body 14 be positioned near tappet bore 18 couple.Tappet roller 48 is shown as contact cam 28, especially demonstrates the ramp 31 that seems cam 28 and nose 29 subsequently has been rotated through roller 48.Ramp 31 and nose 29 illustrate wear mark 33.Further describe the significance of wear mark in the basic reason of the failure mode of diagnosis angular displacement restriction fixture on cam and the improvement in this solution presented below.

With reference now to Fig. 3, show tappet assembly 30, it may present to exit and use in motor 10, or before using in input motor 10, and show other feature.Valve tappet 42 can comprise elongated tappet body 50, and elongated tappet body 50 has outer surface 52 and inner peripheral surface 54.Inner peripheral surface 54 defines longitudinal push-rod hole 56 with central axis 35.Tappet body 50 comprises multiple axial main body section further, comprises the nearly section 60 and section far away 64 that define the opening 62 leading to hole 56.Section 64 far away defines the transverse holes 66 with central axis 37, and wherein tappet roller 48 is rotatably located.Main body 50 also can comprise: fixture section 68, and this fixture section is axially positioned between nearly section 60 and section 64 far away; Intermediate section 69, this intermediate section is axially positioned between fixture section 68 and section 64 far away; And changeover portion 71, this changeover portion is axially positioned between this fixture section 68 and nearly section 60.Each in nearly section 60, section 64 far away and intermediate section 69 can comprise complete diameter section, and limits complete outside dimension, and fixture section 68 can limit the outside dimension 72 of reduction, for receiving support 94 around valve tappet 42, to form assembly 30.

Refer again to Fig. 4 now, show the plan view of a part for tappet assembly 30.Tappet body 50 also can comprise otch 74, and this otch 74 extends axially through nearly section 60, and recessed from outer surface 52.Otch 74 comprises sidewall 76, the sidewall defines proximal channel 78 and the distal end taper portion 80 of otch 74.Passage 78 is configured to coordinate with the straightway of suspension bracket 96, as discussed further in this, thus rotatably tappet body 42 is connected to fixture 92, and the angular displacement of tappet assembly 30 is limited by the restriction of the angular displacement of fixture 92.From Fig. 2, can remember, tappet assembly 30 is coupled with wall section 19 by suspension bracket 96.The angular displacement restriction stop position of fixture 92 can further describe as being limited by the contact be connected between the curved section of suspension bracket 96 of described straightway and wall section 19 at this.By Fig. 4, it should be noted, tapered portion 80 is widened from passage 78 along distal direction.The tapered portion 80 of widening by this way provides gap at sidewall 76 and from support 94 between the first stress of the straightway transition of suspension bracket 96 and the second stress relieve fillet 114, make the rest position at fixture 92 as above, the impact of sidewall 76 on fillet 114 is suppressed.

Referring now to the valve tappet 42 illustrated in Fig. 5, figure in the removed situation of fixture 92.In the embodiment shown, otch 74 is included in and whole otch 74 extends and is orientated the smooth rear wall 82 being parallel to longitudinal axis 35.Rear wall 82 can be directed perpendicular to sidewall 76.Smooth sunk surface 90 can partly be formed in fixture section 68 and part is formed on the changeover portion 71 of tappet body 50, makes smooth rear wall 82 and sunk surface 90 be without transition.Sunk surface 90 provides the depression of the exterior contour of tappet body 50, to hold the feature of the complementary shape of fixture 92, as discussing further herein.Refer again to Fig. 6 now, each section 60 can be recalled, 64 and 69 can limit complete outside dimension.In figure 6, this size is illustrated by reference character 70, and can equal about 30 millimeters in the implementation strategy of reality.In a particular embodiment, size 70 can equal about 29.5 millimeters.Term " about " used herein should be understood in the implication of the rounding of main number and quantity, and therefore, " about " 30 millimeters means from 25.5 millimeters to 30.4 millimeters." about " 29.5 millimeters represent from 29.45 millimeters to 29.54 millimeters etc.Also show the outside dimension of the reduction limited by fixture section 68 in Fig. 6, and represented by reference character 72.In actual implementation strategy, size 72 can equal about 20 millimeters, and more specifically equals about 20.9 millimeters.Passage length size 77 is also show in Fig. 6.Size 77 can equal about 6 millimeters, and more specifically equals about 5.7 millimeters.

In the diagram of Fig. 6, it is further noted that sidewall 76 can be mirror image each other, and eachly comprise the proximal part 86 of straight line and the distal portions 88 of arc, make straight part 86 define passage 78 and curved portion 88 limits tapered portion 80.Straight part 86 can be parallel to each other, and distal portions 88 can be recessed, thus make otch 74 define the shape of tallboy.Each curved portion 88 can also further define the segmental arc 81 of common circle, and it has the radius being greater than about 5 millimeters, and it can equal about 10 millimeters in a particular embodiment.Another outside dimension 79 has been shown in Fig. 6, and it is limited by changeover portion 71.Size 79 can equal about 24 millimeters, more especially equals about 23.6 millimeters.Return and briefly consult Fig. 4, will wander back between sidewall 76 and fillet 114 and there is gap.This gap can comprise axis and circumferencial direction gap.Should also be noted that the radius of curvature of the depression that curved portion 88 limits is greater than the radius of curvature of the depression that each fillet 114 limits.From Fig. 3 to Fig. 6, another feature of understandable tappet assembly 30 is that nearly section 60 and section far away 64 can be understood to limit cylindrical space shell.A part for support 94 and suspension bracket 96 can be positioned at this cylindrical space shell, and its significance will understand further from following description.Although invisible in Fig. 3-Fig. 6, fixture 92 can comprise the smooth inner surface relative and parallel with rear wall 82 with sunk surface 90, and described smooth inside surface portion is formed on the straightway of suspension bracket 96, and part is formed on support 94.

Referring now to Fig. 7, the figure shows the rear view of valve tappet 42, rotate about 180 ° from the view shown in Fig. 6.Can notice, in Fig. 7, the feature of visible tappet body 50 can be substantially identical with the feature shown in Fig. 6, except otch 74 and sunk surface 90.Forward Fig. 8 to, show the top view of valve tappet 42, particularly look down and access aperture 56 along axis 35 because it presents.From Fig. 8 it should be noted that sidewall 76 is oriented perpendicularly to rear wall 82 and rear wall 82 adjoins.Also show the radial depth 84 of otch 74 in Fig. 8, rear wall 82 is recessed into from outer surface 52 thus.In a kind of implementation strategy of practicality, the degree of depth 84 can equal about 15% or larger of whole outside dimension 70.Can contemplate embodiment, wherein size 84 equals about 5 millimeters, more especially equals about 4.75 millimeters.Also show the width dimensions 75 of otch 74, and about 9 millimeters can be equaled, and be about 8.8 millimeters in some embodiments.With reference to Fig. 9, show the bottom view of valve tappet 42, this figure sees along axis 35 at proximal direction.

Forward Figure 10 to, show the view of a part for valve tappet 42, and some geometric attribute difference of the valve tappet 42 compared with designing with known valve stem is shown.In Fig. 10, the special characteristic of known valve tappet design is shown by a dotted line.Such as, can notice, comprise otch at known lifter designs, but the relative narrower passage that only formed of this otch and at all do not have tapered portion.Although Known designs comprises the plat surface with its otch transition, this surface is narrower, shorter, and the shape different from the smooth sunk surface 90 of valve tappet 42.Changeover portion in known gas gate design is slightly narrower than changeover portion 71, and the fixture section in known lifter designs has the relatively large outside dimension than being limited by fixture section 68.Although be not easy due to the point of observation of Figure 10 to understand, the degree of depth of otch 74, size 84, the degree of depth of the otch of Known designs also can be greater than.

Forward Figure 11 and Figure 12 to now, show two different views of fixture 92 and illustrate some feature in more detail.Fixture 92 can comprise single type metal master 93, and it is by such as being formed from single punching press, and single type metal master 93 comprises support 94 and suspension bracket 96, and is configured to couple with valve tappet 42, to form tappet assembly 30, as mentioned above.Support 94 can comprise the first jaw 98 and the second relative jaw 98, and connects the base 102 of jaw 98.Each jaw 98 can be arc, and base 102 can be straight, forms C shape shape in this first plane to make support 94.This C type is readily appreciated that in fig. 12.Each jaw 98 can comprise near-end 104 and the far-end 106 freely of adjacent base 102.In fixture 92, " near-end " represents the position being connected to support 94 closer to suspension bracket 96, and " far-end " refers to away from this position.Holder 94 also comprises the opening side 108 limited by far-end 106 freely, for the fixture section 68 of support 94 around valve tappet 42 being clamped to form tappet assembly 30.Suspension bracket 96 is given prominence to along the direction perpendicular to the first plane from support 94.Therefore, although suspension bracket 96 is actually bending, its outstanding general direction can be understood to the plane perpendicular to C shape place.Suspension bracket 96 can also comprise straight proximal part 110, and as mentioned above, it is connected to base 102 and can be positioned in otch 74 so that fixture 92 is coupled to tappet 42 rotatably.Suspension bracket 96 may further include distal portions 112.This distal portions 112 is bending, and make when fixture 92 is assembled with tappet 42, distal portions 112 bends from axis 35 radially outward.In certain embodiments, distal portions 112 can be understood to be in the second plane perpendicular to the first plane and form U-shaped, and is configured to fixture 92 and tappet assembly 30 to be connected with wall section 19, as described in this.

Can recall, fixture 92 can comprise the inner surface of plane, and it can be oriented to relative with sunk surface 90 and parallel with the rear surface 82 of tappet body 50.In fig. 12, the inner surface 124 of the plane be formed in main body 93 is shown.Opposed inside surface 124 is smooth outer surfaces 120, and is formed on base 102.The straight part 110 of suspension bracket 96 can comprise the outer surface 122 of another plane, and also transition adjacent with outer surface 120.Observe, the known jig Design with nonpitting exterior contour is along with the tappet assembly comprising this fixture is in tappet bore inward turning then tappet bore of can wearing and tearing.Main body 93 can be understood to include wear-resistant exterior contour, and it is constructed to suppress to interfere between base 94 and tappet bore 18 between the tappet bore 18 inward turning refunding at tappet assembly 30.Wear-resistant exterior contour is partly limited by surface 120, and it would not contact tappet bore 18, and the interference between such tappet bore 18 and fixture 92 occurs mainly through far-end 106.In a kind of implementation strategy of practicality, the linearity range that wear-resistant exterior contour can comprise the first bow-shaped section limited by first in jaw 98, the second bow-shaped section limited by another in jaw 98 and be limited by base 102.This section of resistance to wearing exterior contour and its correspondence is the most obvious in the first plane above-mentioned, and understands by description subsequently further.

Referring now to Figure 13, show the front elevation of fixture 92.Can notice, main body 93 is formed as T-shaped in the 3rd plane, and the 3rd plane is the plane of the page in Figure 13, and it is perpendicular to the first plane and the second plane.It should also be noted that support 94 comprises smooth upper edge surface 116, and the lower edge surface 118 of non-flat forms.Each fillet is from smooth upper edge surface 116 to suspension bracket 96 upwards camber.Each fillet 114 further defines radius in the 3rd plane, and this radius is from about 2 millimeters to about 4 millimeters.In a particular embodiment, this radius limited by fillet 114 can equal about 3 millimeters.The radius of disclosed size has been found to give suitable stress spread characteristic to suppress fixture 92, the particularly fatigue failure of suspension bracket 96 in maintenance.The radius of disclosed size also considers it is consistent with other, if coordinated with valve tappet 42 by fixture 92, and exceedingly can not change the shape of valve tappet 42, avoid the impact of sidewall 76 on fillet 114, and have manufacturability.Also show in Figure 13 and install auxiliary taper 130, this is conducive to assembly 30 to slide in tappet bore 18.Auxiliary taper 130 is installed narrow on the direction contrary with the projected direction of suspension bracket 96.

With reference to Figure 14, it illustrates the rear view of fixture 92, and with the geometric attribute by means of the known clamps shown in dotted line, some geometric attribute of main body 93 is by comparison shown.Can notice, known jig Design does not comprise stress spread fillet, but comprises the space limited by the top edge of fixture, is starting to be bent upwards and before being transitioned into suspension bracket, this top edge starts to be bent downwardly from support.Above-mentioned 3rd plane comprises the plane of the page in Figure 13 and Figure 14.

Forward Figure 15 to, show the plan view of fixture 92, and the angle 128 limited by each distal surface 126 clamping 98 is shown.The first above-mentioned plane is the plane of the page in Figure 15.In a kind of implementation strategy of practicality, angle 128 can equal about 110 ° or larger.Having been found that this angle makes jaw 98 launch, engaging around valve tappet 42 for making fixture 92 with enlarged openings side 108.Can also see, jaw 98 is arcs, and each other in mirror image.The width dimensions 135 of suspension bracket can equal about 9 millimeters, more especially equals about 8.58 millimeters, and straight part 110 can be engaged in passage 78.With reference to Figure 16, show the bottom view of fixture 92, and show non-planar surface lower surface 118.Being formed to install assists taper 130 to occur as follows, that is: make the downside in jaw portion 118 curve inwardly, and makes lower surface 118 roughly in coniform, at least within jaw portion 118.Each distal surface 126, also can be processed to remove sharp edge when them and lower surface 118 transition, shows as the distal surface 126 of curve form.

With reference now to Figure 17, show the sectional view intercepted along the 17-17 line in Figure 15.In this sectional view of Figure 17, the crooked outline between upper surface 116 and lower surface 118 is apparent.The thickness size 125 of main body 93 is also show in Figure 17.In certain embodiments, thickness 125 can be even throughout main body 93, and can be less than the radius of fillet 114 restriction.Thickness 125 from about 2 millimeters to about 4 millimeters, more especially about 2.0 millimeters to about 3.0 millimeters, can more especially approximate 2.5 millimeters.Also show the height dimension 133 of support in Figure 17, it is from upper surface 116 to the lowermost portion of support 94 or most advanced and sophisticated measure, this lowermost portion or most advanced and sophisticated adjacent lower surface 118 or be the part of lower surface 118.In one embodiment, size 133 can equal about 8 millimeters, more especially approximates 8.13 millimeters.With reference to Figure 18, show the sectional view intercepted along the 18-18 line in Figure 15.Above-mentioned second plane comprises the page institute of Figure 18 planar.Figure 18 shows the height dimension 131 of suspension bracket, as tip from the upper surface 116 of suspension bracket 96 to distal portions 112 is measured.In one embodiment, size 131 can approximate 5 millimeters, more especially approximates 4.6 millimeters.The linear profile that plat surface 120 and 122 limits is also show in Figure 18.

Referring now to Figure 19, fixture 92 is shown again, and compared with those geometric attributes that some geometric attribute of main body 93 and known clamps are designed.Can recall, main body 93 comprises the exterior contour that resistance to wears, and known jig Design tends to have the exterior contour not preventing wearing and tearing tappet bore.In Figure 19, some feature of known jig Design illustrates by means of dotted line.Can notice, except there is the exterior contour of the linearity range limited by surface 120, also to have in known jig Design and employ nonpitting crooked outline.Also show another angle 129 in Figure 19, in known jig Design, it can be limited by the distal surface in the jaw portion of support.Angle 129 is less than angle 128.The thickness of the main body of known clamps is also less than thickness 125.

Industrial applicibility

Always with reference to each accompanying drawing, motor 10 is burnt in cylinder 16 by the mixture of fuel and air, and driven plunger 20 rotates in a conventional manner to make bent axle 24.The rotation of bent axle 24 will cause camshaft 26 to rotate, make cam 26 against roller 48 rotate and in tappet bore 18 upwards sliding air gate tappet 42 to open valve 36.Biasing spring is coupled with rocking arm 34 and tends to returned to camshaft 26 by valve tappet 42 and close valve 36.Can recall, in motor 10 is safeguarded, fixture 92 is couple to valve tappet 42 rotationally.In motor 10 operation period, valve tappet 42 can rotate and misplace with cam 28.Because the rotation of fixture 92 with valve tappet 42 couples, the moment of torsion that valve tappet 42 is rotated is sent to fixture 92, and fixture 92 and valve tappet 42 are rotated simultaneously.Especially, this moment of torsion can at least mainly be contacted by the straight part 110 of the straight part 86 with suspension bracket 96 that make sidewall 76 and be transmitted.Suspension bracket 96 couples with the wall section 19 in motor 10.Usually there is gap between each in the outside and inner side of suspension bracket 96 and wall section 19, this is contrary with Earlier designs, and in early days in design, fixture at least contacts the inner side of cylinder wall part.Inner side 23 and the outside 21 of wall section 19 represent in fig. 20.Inner side 23 can be rounding, and along with tappet bore 18 transition, and outside 21 can have totally straight shape, makes fixture 92 travelling bridge 96 rotated together with valve tappet 42, to reduce the gap with wall section 19.The rotation of valve tappet 42 and fixture 92 will be tending towards continuing, until gap is reduced to zero, will make the contact between suspension bracket 96 and wall section 19 that fixture 92 is stopped the rotation and will therefore make valve tappet 42 stop the rotation.

In fig. 20, show fixture 92, it may present wherein valve tappet 42 and rotate into and misplace with cam 28, and then it rotates and stops at the angular displacement limited by the contact between fixture 92 and wall section 19 and limit stop position.Angle 140 is also shown in Figure 20, and is identified in the approximate angular displacement that the position of the valve tappet 42 alignd with cam 28 and angular displacement limit the valve tappet 42 and fixture 92 occurred between stop position.In one embodiment, angle 140 can equal about 20 °.Different valve tappet assemblies can have different performances each other in maintenance.In many cases, fixture 92 can rotate about 20 ° from aligned position in the either direction clockwise and in counter clockwise direction.Therefore, fixture 92 can rotate about 40 ° altogether between two angular displacement restriction stop positions.But according to motor and each valve tappet assembly, this angle can change.In addition, some valve tappet assembly can have in one direction than the trend that another direction rotates more.Under any circumstance, can tappet assembly be applied in one or more angular displacement restriction rest position power, in fixture, cause stress.In fixture 92, these stress are diffused by fillet 114, make the fatigue failure of fixture 92 suppressed, and make exceed the working life of motor 10 in working life of tappet assembly 30.According to the reason will explained below, the basic reason that these stress produces and the improvement being expected to successful solution all do not realize for a long time.

Those skilled in the art will be familiar with the concept of engine dynamics.Along with internal combustion engine operation, the dimensional changes that many different linear and rotating force, vibration, thermal conductance cause and other factors, can combine, superpose, subtract each other or otherwise in cross-couplings and unpredictable mode interact with each other.Therefore, any given assembly or method, although the engineering effort of the best, to show from desired different mode, to perform, or can occur.Even if seem small change in the geometrical shape of parts, engine operation parameters or other features, also significant and uncertain impact can be had on engine dynamics.As mentioned above, between motor identical from the teeth outwards, can usually observe significant change, between even identical on interior engine surface part, usually observe the change in phenomenon.The rotation of valve tappet is the phenomenon be considered to because the complicated phenomenon of engine dynamics causes.Challenge in Complete Characterization engine dynamics result in the difficulty solving the problem that tappet rotates, and prevents various to the solution of tappet rotation and the predictability of consequence thereof.

In jig Design comparatively early, as the design by comparison illustrated with the fixture 92 in Figure 14 and Figure 19, the fatigue failure of fixture occurred sometimes before the ordinary life of relevant motor terminates.Two common failure modes have been observed in known jig Design.In some cases, suspension bracket can probably be transitioned into the position of its distal portions in its straight part or lose efficacy in its bending distal portions itself.In particular case, suspension bracket can lose efficacy in " root ", the position that is roughly fixed to described support in straight part.When there is relatively large gap between the sidewall believing the passage formed in the straight part that rear a kind of failure mode is tended to appear at fixture suspension bracket and the valve tappet that is associated.The former failure mode is tending towards occurring in gap when being comparatively tight.The tolerance stack-ups can be sure oing between fixture and valve tappet acts on these changes from tappet assembly to tappet assembly at least partly.The common basic reason of these different failure modes only could be disclosed after extensively studying.

Can recall, wear mark 33 can be formed on cam 28 during safeguarding from contacting with tappet roller 48, as shown in Figure 3.Can notice, mark 33 changes a little on width, but is from left to right symmetrical usually on cam 28.Causing in the research process lost efficacy to tappet assembly of the present utility model, proposing such wear patterns can observe in the self aligned place of valve tappet.This just means, described valve tappet can angular displacement during safeguarding, it may be inclined to adjust to ideal orientation, causes symmetrical wear patterns wider in time.Also observe and tend to the incidence rate that self aligned tappet assembly seems to have the fixture fatigue failure of reduction.In the design that known generation was lost efficacy, also observe wear mark on the cam of correspondence and mark 33 and look different, thinner, absolutely wrong title sometimes, therefore point out this valve tappet at least can not self-aligning in some times.Self aligned reason can not remain unknown in this respect.

With reference to Figure 21, show the valve tappet 142 and fixture 192 that are positioned at cylinder body 114, outside making the suspension bracket of fixture 192 and having 121 and inner side 123 wall section 119 be coupled.Different from the structure shown in Figure 20, tappet 142 and fixture 192 are installed into and make because bolt is connected the position of projection 200 and produce intrinsic dislocation.In other words, fixture 192 and tappet 142 can not be arranged on accurate ideal orientation relative to corresponding cam.In the example illustrated, tappet 142 and fixture 192 only can be arranged in the orientation of angle 141 of restriction, and itself and ideal orientation depart from and is approximately 10 °.

When observing the wear patterns on a lot of different cam, comprise those and the cam misplaced inherently and self-aligning tappet assembly is coupled, find that intrinsic dislocation may cause the different wear patterns in respective cams, this pattern is similar to but is different from the wear patterns that the cam that is associated with the fixture that lost efficacy is observed.By the feature of the further motor that lost efficacy of gauging fixture and a lot of tappet assembly again, infer that the tappet of intrinsic dislocation and clamp assembly itself are associated with the risk increase of losing efficacy further.This similarity of wear patterns, and the possibility obviously shared of fixture fatigue failure, finally cause following hypothesis, that is: the fixture of inefficacy may experienced by the maintenance condition similar with intrinsic dislocation fixture.Although the character of these maintenance conditions still keeps unknown, the friction markings of additional observations in tappet bore finally obtains drawing a conclusion, namely various factors has made fixture " hang-up " and can not self-calibrating in tappet bore, causes stress to be enough to finally cause fatigue failure.This conclusion itself is familiar with contrary with routine, and conventional understanding is: valve tappet always tends to self-regulating.Once tappet assembly, the phenomenon that especially fixture is suspended starts revealed, just can investigate potential cause.Believe now, between motor, and the change between tappet assembly causes such trend, that is: based on the interaction with cylinder body, and the constraint of some tappet assemblies experience on it rotates, and everything does more freely rotates.Can be why these valve tappets are different from other performance and reliably can not turn back to a special reason of aligned position from deviation post from a motor to the change of the size of another cylinder wall part.No matter can not self-aligning, flexural load on fixture and torsional load, finally how cause concrete reason after viewed failure mode, be considered to the sharpest: tappet assembly hangs over angular displacement restriction stop position, and then tappet roller is contacted with nose by the ramp of the rotation of cam of being correlated with.

The utility model solves the problem that in valve tappet assembly, fixture lost efficacy, the working life of motor can be extended, this is at least in part by being designed to the tolerance higher to such bending and torsion load by fixture 92, and by valve tappet 42 being designed to hold fixture 92 best and realizing.As mentioned above, fixture 92 and valve tappet 42 are different from known design respectively in many ways.These differences are supplemented mutually, and failure mode discussed above can no longer be occurred, or need just can occur for a long time during normal engine operation, make exceed the working life of motor 10 in working life of tappet assembly 30.Those skilled in the art will be familiar with the whole engine design of change, comprise new parts, changes the undesirable property of parts or the space floor space of assembly and the change of other fundamental sum costliness.As mentioned above, engine dynamics can substantive and uncertain mode change, even if make minor alteration.May be effective to a challenge or the solution of problem, but often can produce new with unexpected failure mode or have otherwise defect, let alone fringe cost.

But, the feature of this fixture 92 and valve tappet 42, and these features are interact with each other and be conservatively improve in known design with the mode of action of other parts of motor 10, and do not produce new failure mode, and without the need to revising motor itself.Fixture 92 can be thicker and have the shape different from Known designs, as mentioned above.This thickness of fixture 92 is considered to make main body 93 firmer, and fillet 114 has spread the stress that may cause fatigue failure, and the exterior contour that resistance to wears stops fixture against the dragging of tappet bore 18 when fixture rotates to angular displacement restriction stop position and rotates from angular displacement restriction stop position.In the implementation strategy of practicality, fixture 92 can be designed so that far-end 118 and tappet bore 18 have relative gentle interference fit, and other parts of support 94 are not interfered.The fixture contemplated herein also can have the interference reducing or eliminate between suspension bracket and the wall section of cylinder body, contrary with existing design, and in the latter, the bottom of suspension bracket is slightly outwardly and create and think now and interference that is less desirable and tappet bore.When valve tappet 42, the outer surface 90 of depression makes more closely and better to mate with fixture 92 to coordinate, and the thickness that relatively darker otch 74 holds fixture 92 increases, and tapered portion 80 guarantees that sidewall 76 will not impact on fillet 114.Tappet assembly 30 will typically have such space floor space, and tappet assembly 30 can be arranged in motor 10, and not need to make other improvement any to hardware or operation strategy.Therefore, can be understood as at particular aspects the utility model and the material of fixed qty be re-assigned to another from parts, and from existing valve tappet assembly can floor space change space floor space.Wherein valve tappet assembly lost efficacy, or therefore the motor being considered to lose efficacy can be safeguarded by changing existing tappet assembly according to valve tappet assembly of the present utility model into.

This description only for illustration of object, and should not be interpreted as reducing scope of the present utility model by any way.Therefore, those skilled in the art will recognize that, under the prerequisite not deviating from complete and zone of reasonableness of the present disclosure and marrow, can make various amendment to disclosed embodiment at present.Such as, the special characteristic of fixture 92 and tappet 42 has been described to have example sizes and geometrical properties here, and the utility model is not restricted to this, can develop alternative mode of execution based on this instruction.Other side, feature and advantage will become obvious when checking accompanying drawing and appending claims.

Claims

1. one kind for limiting the fixture (92) of the angular displacement of valve tappet (42), the tappet bore (18) that the cylinder body (14) that described valve tappet (42) is arranged in internal-combustion engine (10) is formed; It is characterized in that, described fixture comprises:

Single type metal master (93), comprises support (94) and suspension bracket (96);

Described support (94) has the first jaw (98) and relative the second jaw (98), and connect the base (102) of described first jaw and the second jaw (98), so that described support (94) forms C shape in the first plane, each in first jaw and the second jaw (98) comprises near-end (104) and the free distal end (106) of adjacent described base (102), described support (94) also has the opening side (108) limited by described free distal end (106), for clamping described support (94) around described valve tappet (42) to form tappet assembly (30),

Described suspension bracket (96) is given prominence to from described support (94) on the direction perpendicular to described first plane, and there is straight proximal part (110), described straight proximal part (110) is connected to described base (102) and is arranged in the middle otch (74) formed of described valve tappet (42) to be rotatably connected thereto by described fixture (92), and described suspension bracket (96) also has the distal portions (112) forming U-shaped in the second plane perpendicular to described first plane, for the wall section (19) of described tappet assembly (30) with the described cylinder body (14) of contiguous described tappet bore (18) is connected, and

Described single type metal master (93) has the external frame that resistance to wears, the described external frame that resistance to wears be configured to towards and limit stop position from the angular displacement limited by the contact between described suspension bracket (96) and wall section (19) and rotate the process of described tappet assembly (30), suppress the interference between described base (102) and described tappet bore (18), described single type metal master (93) also comprises the first fillet and the second fillet (114) that are transitioned into described straight proximal part (110) from described base (102), for spreading in described angular displacement restriction rest position the stress caused in described fixture (92).

2. the fixture (92) of the angular displacement for limiting valve tappet (42) according to claim 1, is characterized in that, described single type metal master (93) is forming T-shaped perpendicular in the 3rd plane of each in described first and second planes;

Wherein, described support (94) comprises smooth upper edge surface (116) and the lower edge surface (118) of non-flat forms, and each described first fillet and the second fillet (114) upwards form arc from described smooth upper edge surface (116) to described suspension bracket (96); And

Wherein each described first fillet and the second fillet (114) limit radius in described 3rd plane, and described radius is from 2 millimeters to 4 millimeters.

3. the fixture (92) of the angular displacement for limiting valve tappet (42) according to claim 2, it is characterized in that, described in the external frame that resistance to wears be included in described first plane the first arcuate segment, the second arcuate segment limited by described second jaw (98) and the straightway limited by described base (102) that are limited by described first jaw (98).

4. the fixture (92) of the angular displacement for limiting valve tappet (42) according to claim 3, is characterized in that, described single type metal master (93) comprises uniform thickness, and described uniform thickness is from 2.0 millimeters to 3.0 millimeters;

Wherein said first jaw (98) comprises the first distal surface (126), and described second jaw (98) comprises the second distal surface (126), and wherein said distal surface (126) predetermined angle, described angle is more than or equal to 110 °, and wherein said first jaw and the second jaw (98) have arcuate structure separately, and be mirror image each other.

5. the fixture (92) of the angular displacement for limiting valve tappet (42) according to claim 4, it is characterized in that, described support (94) be also included in the side outstanding with described suspension bracket (96) in the opposite direction on the installation that narrows assist taper (130).

6. one kind for limiting the fixture (92) of the angular displacement of valve tappet (42), it is characterized in that, caused by engine dynamics between the assembly (30) of the described valve tappet (42) of described angular displacement in internal-combustion engine (10) and the spreadable life of described fixture (92), described fixture (92) comprising:

Described support (94), there is the first jaw (98) and relative the second jaw (98) and the base (102) being connected described first jaw and the second jaw (98), so that described support (94) forms C shape, each in described first jaw and the second jaw (98) comprises near-end (104) and the free distal end (106) of adjacent described base;

Described support (94) also has the opening side (108) limited by described free distal end (106), so that separately described free distal end (106) expands described opening side (108), for clamping described support (94) around described valve tappet (42) to form described assembly (30);

Described suspension bracket (96) is given prominence to from described support (94), and has the distal portions (112) forming U-shaped, for being connected by the wall section (19) of contiguous to described assembly (30) and cylinder body (14) tappet bore (18) in described internal-combustion engine (10);

Described suspension bracket (96) also has straight proximal part (110), described straight proximal part (110) is connected to described base (102) and is arranged in the middle otch (74) formed of described valve tappet (42), to be connected thereto by described fixture (92) rotatably, limited the angular displacement of described valve tappet (42) at stop position by the contact between described suspension bracket (96) and described wall section (19); And

Described fixture (92) also has component, and described component comprises shape and the thickness of described single type metal master (93), and the stress for causing in response to rest position suppresses the fatigue failure of described suspension bracket (96).

7. the fixture (92) of the angular displacement for limiting valve tappet (42) according to claim 6, it is characterized in that, described single type metal master (93) also comprises the first fillet and the second fillet (114) that are transitioned into described suspension bracket (96) from described support (94), each in first fillet and the second fillet (114) has the stress spread arc limiting radius, and wherein said base (102) comprises the external frame that resistance to wears, described in the external frame that resistance to wears be configured to suppress the interference between described support (94) and described tappet bore (18);

Wherein said single type metal master (93) comprises uniform thickness, and described uniform thickness is between 2 millimeters to 4 millimeters, and described radius is between 2 millimeters to 4 millimeters; And

Wherein said uniform thickness is less than described radius.