CN100416048C

CN100416048C - Rotation prevention device for rocker arm

Info

Publication number: CN100416048C
Application number: CNB2004800072790A
Authority: CN
Inventors: 久保田良; 菊池一纪
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2003-03-19
Filing date: 2004-03-17
Publication date: 2008-09-03
Anticipated expiration: 2024-03-17
Also published as: JP2004285845A; MXPA05007402A; KR101013253B1; WO2004083609A1; TWI248491B; TW200424425A; JP4052964B2; KR20050109473A; CN1761803A

Abstract

A pair of rocker arm shafts (26) is supported parallelly spaced from each other in a cylinder head (4) of an internal combustion engine. A pair of rocker arms (28, 28) that respectively connect suction/discharge cams (18a) and suction/discharge valves (15, 16) is swingably supported by each rocker arm shaft (26). A cutout (26a) is formed in portion of each rocker arm shaft (26) in an opposing manner. Between the cutouts (26a) is inserted a restriction member (40) with a shape of which both side edges are not parallel when viewed in the axial direction of a cam shaft. The restriction member (40) is pressed against both cutouts (26a) by an inner surface of a cylinder head cover (5). The structure above solves a problem of a gap produced when a rotation prevention member of rocker arm shafts in a valve-operating device of an internal combustion engine is tightened, and solves a problem of hitting noise produced by idling of the rocker arm shafts during engine operation.

Description

Be used to prevent the device of pitman arm shaft rotation

Technical field

The present invention relates to the device that a kind of pitman arm shaft that is used for preventing the valve operating system of internal-combustion engine rotates.

Background technique

Up to now, known use one break stops dismounting to press fit over pitman arm shaft (for example referring to JP2000-329002A, Fig. 6 and Fig. 7) in the rocker shaft hole.Also become known for preventing the device of pitman arm shaft rotation, as shown in Figure 8.This pitman arm shaft rotation arrester has pressing plate 040, and this pressing plate 040 is fixed on the cylinder head 04 by clamping bolt 023 at the middle part between two pitman arm shafts 026 at it.Pressing plate 040 has left arm and right arm, and the rotation that this left arm and right arm have the symmetry on the lower surface that is formed on its opposite end prevents surperficial 040a.Rotation prevents that surperficial 040a is retained as and abuts against corresponding otch 026a and be used to prevent that pitman arm shaft 026 from rotating that this otch is limited in two pitman arm shafts 026.In Fig. 8, reference character 018 expression camshaft, reference character 019 expression camshaft bearing.

When the pressing plate 040 of above-mentioned pitman arm shaft rotation arrester is fastened by clamping bolt 023, rotate on pressing plate 040 edge wherein clamping bolt 023 fastened direction, thereby the otch 026a of a pitman arm shaft 026 (the left pitman arm shaft among Fig. 8) prevents to form a micro-gap S between the surperficial 040a with the rotation of the pressing plate 040 that is associated therein, and wherein this described pitman arm shaft 026 is positioned at the back of pressing plate 040 with respect to the sense of rotation of pressing plate 040.Therefore, when internal combustion engine, gap S makes pitman arm shaft 026 dally, thereby produces Strike note.

Summary of the invention

The purpose of this invention is to provide the device that a kind of pitman arm shaft that is used for preventing the valve operating system of internal-combustion engine rotates, wherein prevent the fastening gap that forms owing to pressing plate.

In order to address the above problem, the invention provides the device that a kind of pitman arm shaft that is used for preventing the valve operating system of internal-combustion engine rotates, it has: a pair of pitman arm shaft, described pitman arm shaft are arranged in the cylinder head each other at interval side by side; A pair of rocking arm, described rocking arm are retained as respectively and contact with exhaust valve with exhaust cam and corresponding intake valve with corresponding intake cam, and are supported swingably by described pitman arm shaft; And limiting component, be used to prevent that pitman arm shaft from rotating, it is characterized in that, described pitman arm shaft is formed with otch respectively on its part, these otch are inclined surfaces and face mutually and assemble downwards, described limiting component has when uneven side margin when the axial direction of camshaft is seen, and the true dip direction of described side margin is identical with the true dip direction of described otch; And described limiting component is plugged between the described otch, and described limiting component is pushed by the internal surface of valve mechanism cover.

In the present invention, have along the limiting component of axially seeing uneven side margin of camshaft and be inserted between the opposed facing otch, these otch are formed in the described pitman arm shaft, and described limiting component is pushed by the internal surface of valve mechanism cover.Therefore pitman arm shaft is fixed to mutual closely the contact and can not produces the motion of sending cracking sounds with limiting component.Therefore, can prevent the Strike note that the idle running owing to pitman arm shaft produces and the wearing and tearing of bearing.In addition, because limiting component is pushed by valve mechanism cover and is fixed, therefore can exempt the up to the present conventional required clamping bolt that is used for limiting component, hole processing process and the fastening process of pitman arm shaft rotation arrester, thereby have the advantage of manufacture cost aspect.

According to the present invention, described limiting component can form along the direction of camshaft and clip convex portion in the cylinder head.

The wearing and tearing that move axially and prevented them of pitman arm shaft like this, have just been prevented.In addition, utilize existing convex portion to fix described limiting component, thereby described limiting component can be fixed on the appropriate location and not need cylinder head is carried out special processing.

Preferably, a camshaft holder can be used as described convex portion.The cross section of described limiting component can be for inverted U-shaped so that can be assemblied on the described convex portion.Therefore, be convenient to the location of described limiting component.

One elastic component can be arranged between the internal surface of described limiting component and valve mechanism cover and between described limiting component and convex portion.

Therefore, described limiting component can be by secure fixation.In addition, because the vibration of valve mechanism cover is absorbed by described elastic component, therefore can reduce the noise that produces owing to vibration.

Described limiting component preferably remains against the outer surface of a camshaft bearing, thereby has reduced the click sound of camshaft bearing and improved the serviceability of camshaft bearing.

Description of drawings

Fig. 1 is a vertical sectional view of using the internal-combustion engine of the embodiment of the invention, cuts open along the plane of roughly extending by crankshaft center line and cylinder-bore axis and gets;

Fig. 2 is the vertical sectional view of internal-combustion engine, gets along roughly cuing open through described cylinder-bore axis and perpendicular to the plane that described crankshaft center line extends;

Fig. 3 is the vertical sectional view of internal-combustion engine, gets along cuing open perpendicular to the plane of described crankshaft center line extension near the cam timing chain;

Fig. 4 is the zoomed-in view on Fig. 1 top;

Fig. 5 from the top, removed the view of the cylinder head of valve mechanism cover;

Fig. 6 is that the VI-VI line along Fig. 5 cuts open the sectional view of getting;

Fig. 7 is that the VII-VII line along Fig. 4 and Fig. 6 cuts open the sectional view of getting; With

Fig. 8 is the view that conventional being used to of expression prevents an example of the device that pitman arm shaft rotates.

Embodiment

Fig. 1 represents to use the internal-combustion engine of the embodiment of the invention with vertical sectional view, and this sectional view is to get along cuing open by the plane of crankshaft center line and cylinder-bore axis.Fig. 2 represents described internal-combustion engine with sectional view, and this sectional view is to cut open along the plane of extending by cylinder-bore axis and vertical crankshaft axis to get.Fig. 3 represents described internal-combustion engine with sectional view, and this sectional view is to get along cuing open perpendicular to the plane of described crankshaft center line extension near cam chain, and Fig. 4 is with the top of the schedule of proportion diagrammatic sketch 1 of amplification.

Internal-combustion engine 1 is an overhead camshaft four-cycle, single-cylinder internal-combustion engine, and it has main body, and this main body comprises: left crankcase 2a, right crankcase 2b, cylinder block 3, cylinder head 4, valve mechanism cover 5, left crankcase cover 6a and right crankcase cover 6b.Described left crankcase 2a and right crankcase 2b fit together, and cylinder block 3, cylinder head 4 and valve mechanism cover 5 are installed on this assembly in turn.Described left crankcase cover 6a is assemblied on the left-hand face of left crankcase 2a, and right crankcase cover 6b is assemblied on the right lateral surface of right crankcase 2b, and makes described crankcase be sealed by these crankcase covers respectively.Left crankcase 2a, right crankcase 2b, cylinder block 3, cylinder head 4, valve mechanism cover 5, left crankcase cover 6a and right crankcase cover 6b link together by bolt or analog.

As illustrated in fig. 1 and 2, piston 8 is assemblied in the cylinder-bore 7 that is limited in the cylinder block 3 slidably, and bent axle 9 is supported among left crankcase 2a and the right crankcase 2b rotationally.The opposed end of connecting rod 12 is pivotally mounted in respectively on piston 8 and the bent axle 9 by wrist pin 10 and crank pin 11.Owing to be arranged in the burning of air-fuel mixture of firing chamber 13 of cylinder-bore 7 top area during to-and-fro motion, bent axle 9 rotates when piston 8.

As shown in Figure 2, suction port 14 and relief opening 15 are limited in the cylinder head 4, and are communicated with the firing chamber 13 that is arranged in cylinder-bore 7 top area.Intake valve 16 and exhaust valve 17 can be opened and can be installed in respectively in suction port 14 and the relief opening 15 with closing.

Camshaft 18 is arranged near the top of intake valve 16 and exhaust valve 17.On camshaft 18, be provided for the cam lobe 18a and the cam lobe 18a that is used for exhaust valve 17 of intake valve 16.One end of camshaft 18 (left end among Fig. 1 and Fig. 4) is supported between cylinder head 4 and the camshaft holder 20 rotationally by camshaft bearing 19a, and opposite end (right-hand member among Fig. 1 and Fig. 4) is supported in the cylinder head 4 rotationally by camshaft bearing 19b.Driven sprocket 21 and magnetic holder 22 pile up and are installed in integratedly by bolt 23 on the described end of camshaft 18.Driving sprocket wheel 24 is installed on the bent axle 9 integratedly.Ring cam set timing chain 25 is provided with around driving sprocket wheel 24 and driven sprocket 21.

As shown in Figure 2, have top and the top of middle part between camshaft 18 top positions and exhaust valve 17 and the middle part between camshaft 18 top positions that a pair of pitman arm shaft 26 of the axis of level respectively is arranged on intake valve 16.The opposed end of pitman arm shaft 26 is supported in cylinder head 4 and the camshaft holder 20.Rocking arm 28 is supported on respectively on the pitman arm shaft 26 swingably.Roller 29 is pivotably mounted on the corresponding end of rocking arm 28 and is retained against the cam lobe 18a of camshaft 18.The other end of rocking arm 28 is held in against the top of the top of intake valve 16 and exhaust valve 17.When internal-combustion engine 1 operation, camshaft 18 makes when bent axle 9 whenever takes two turns that with half rotational speed of bent axle 9 rotating speeds intake valve 16 and exhaust valve 17 open and close once.

As shown in figs. 1 and 4, one is installed in the cylindrical part that diameter that magnetic holder 22 on the described end (left end among Fig. 1 and Fig. 4) of camshaft 18 has the radially inner side that is positioned at driven sprocket 21 reduces and is positioned at the cylindrical part of enlarged-diameter in the axial outside of the cylindrical part that this diameter reduces.A plurality of permanent magnets 35 uniformly-spaced are installed in integratedly along circumference on the inner circumferential surface of cylindrical part of enlarged-diameter.

Coolant pump 30 is arranged on the outside (left side among Fig. 1 and Fig. 4) of camshaft 18.Coolant pump 30 has: pump cover 31, and it is assemblied in the opening in the sidewall that is defined in cylinder head 4; With the pump housing 32, it has sealing and is assemblied in near-end in the pump cover 31.The pump housing 32 has and the cylindrical part of the enlarged-diameter of magnetic holder 22 cylindrical part at a distance of certain distance.Coolant pump 30 also has pump shaft 33, and this pump shaft aligns with the rotation axis of camshaft 18 and opposed end is supported on respectively in the pump cover 31 and the pump housing 32 rotationally.Rotor 34 is installed on the pump shaft 33 and has cylindrical part, and permanent magnet 36 is installed on this cylindrical part and is in the position that is installed in the permanent magnet 35 on the magnetic holder 22 in the face of one.Blade 37 is installed on the rotor 34 integratedly and is arranged in the cylindrical part outside (left side of Fig. 4) of rotor 34.When driven sprocket 21 rotated, magnetic holder 22 and its unitary rotation made that the permanent magnet 36 on the rotor 34 that is installed in coolant pump 30 integratedly rotates under the magnetic force of the permanent magnet 35 that rotates with magnetic holder 22.Therefore coolant pump 30 is driven rotation.

Fig. 5 from the top, removed the view of the cylinder head 4 of valve mechanism cover 5.Fig. 6 is that the VI-VI line along Fig. 5 cuts open the sectional view of getting, and cuts open the sectional view of getting and Fig. 7 is a VII-VII line along Fig. 4 and Fig. 6.

According to current embodiment, (left end among Fig. 5 and the lower end among Fig. 7) is formed with otch 26a to pitman arm shaft 26 in its end, and these otch are faced mutually.As shown in Figure 6, each otch 26a generally has flat cut surface, and relative flat cut surface is inclined surface, along with their extend downwards and approaching mutually.Insert a pressing plate 40 as limiting component between otch 26a from the top, this pressing plate has from the axial direction of camshaft 18 sees uneven opposite side edge (assembling Fig. 6) downwards.

As Fig. 4 and shown in Figure 6, pressing plate 40 has the top edge of arc lower limb and horizontal curvature, and described lower limb is held in against the outer surface of the outer ring of camshaft bearing 19a.This horizontal curvature partly extends to the zone of camshaft holder 20 tops and is bent downwardly then, thereby clips camshaft holder 20, and wherein said camshaft holder is as the convex portion in the cylinder head 4.As shown in Figure 4, therefore pressing plate 40 has inverted U-shaped section.The convex portion that is used to keep pressing plate 40 can be the protruding part except position that is positioned at contiguous camshaft 18 and the camshaft holder 20 that is positioned at described cylinder head 4.

At the elastic component 42 that is provided with between pressing plate 40 and the camshaft holder 20 and between the internal surface of pressing plate 40 and valve mechanism cover 5 such as rubber parts, and this elastic component 42 is pushed by valve mechanism cover 5.Shape when the dot and dash line 42A among Fig. 6 represents that elastic component 42 is in its free state.When valve mechanism cover 5 had been installed, elastic component 42 was pressed to shape shown in Figure 4.Reference character 27 expressions among Fig. 5 and Fig. 7 are assemblied on the pitman arm shaft 26 to prevent the rocking arm 28 axially movable axle collars.

When the air-fuel mixture of firing chamber 13 was lighted in being supplied to internal-combustion engine 1, fuel combustion descended piston 8 to increase the pressure in the firing chamber 13.Also repeat to supply air-fuel mixture, combustion gas and light air-fuel mixture according to predetermined order and timing (timing) by operation intake valve 16 and exhaust valve 17, piston 8 moves back and forth.Piston 8 move through the rotation that connecting rod 12 was transmitted and converted to bent axle 9, be delivered to wheel (not shown) etc. then.The rotation of bent axle 9 also passes to camshaft 18 by driving sprocket wheel 24, cam timing chain 25 and driven sprocket 21, and is transmitted to open and close intake valve 16 and exhaust valve 17 according to predetermined sequence and timing by cam lobe 18a and rocking arm 28 then.

According to current embodiment, pitman arm shaft 26 is limited with otch 26a in its end, and these otch 26a faces mutually, and not parallel (taper) side margin of axially seeing from camshaft 18 of pressing plate 40 is inserted between the described otch 26a.Pressing plate 40 is pushed by the internal surface of valve mechanism cover 5.Therefore, pitman arm shaft 28 and pressing plate 40 are by the motion of fixing in intimate contact mutually and not sending cracking sounds.Therefore, can avoid producing Strike note and bearing wear owing to the idle running of pitman arm shaft 26.In addition, because pressing plate 40 is pushed by valve mechanism cover 5 and is fixed, therefore can exempt up to the present conventional needed clamping bolt, hole processing process and the fastening process that is used for limiting component of pitman arm shaft rotation arrester, thereby aspect manufacture cost, have advantage.

According to current embodiment, in addition, thereby pressing plate 40 is configured as and clips the motion of camshaft holder 20 on camshaft 18 directions and be limited, and has therefore prevented pitman arm shaft 26 owing to wear and tear along the mobile of its axial direction.In addition, utilize existing cam holder 20 stationary platens 40, thereby pressing plate 40 is fixed on the appropriate location and does not need cylinder head 4 is carried out special processing.

According to current embodiment, in addition, at the elastic component 42 that is provided with between pressing plate 40 and the camshaft holder 20 and between the internal surface of pressing plate 40 and valve mechanism cover 5 such as rubber parts, thereby described pressing plate 40 is fixed in position reliably.Because the vibration of valve mechanism cover 5 is absorbed by elastic component 42, therefore reduced the noise that produces owing to vibration.

According to current embodiment, in addition,, can prevent that therefore camshaft bearing 19a from click sound taking place and improved serviceability because the lower end of pressing plate 40 is retained against the outer surface of the outer ring of camshaft bearing 19a.

Claims

1. device that is used to prevent that pitman arm shaft from rotating, its pitman arm shaft that is used for preventing the valve operating system of internal-combustion engine rotates, and have: a pair of pitman arm shaft, described pitman arm shaft are arranged in the cylinder head each other at interval side by side; A pair of rocking arm, described rocking arm are retained as respectively and contact with exhaust valve with exhaust cam and corresponding intake valve with corresponding intake cam, and are supported swingably by described pitman arm shaft; And limiting component, described limiting component is used to prevent that pitman arm shaft from rotating, it is characterized in that,

Described pitman arm shaft is formed with corresponding otch on its part, these otch are the surfaces that tilt, and these otch are faced mutually and assembled downwards; Described limiting component has when uneven side margin when the axial direction of camshaft is seen, and the true dip direction of described side margin is identical with the true dip direction of described otch; And described limiting component is plugged between the described otch, and described limiting component is pushed by the internal surface of valve mechanism cover.

2. the device that is used to prevent that pitman arm shaft from rotating according to claim 1 is characterized in that, described limiting component is configured as along the axial direction of described camshaft and clips convex portion in the cylinder head.

3. the device that is used to prevent the pitman arm shaft rotation according to claim 2 is characterized in that described convex portion is the camshaft holder.

4. the device that is used to prevent the pitman arm shaft rotation according to claim 1 and 2 is characterized in that described limiting component has inverted U-shaped section.

5. the device that is used to prevent that pitman arm shaft from rotating according to claim 1 and 2 is characterized in that, an elastic component is arranged between the described internal surface of described limiting component and valve mechanism cover and between described limiting component and the described convex portion.

6. the device that is used to prevent the pitman arm shaft rotation according to claim 1 and 2 is characterized in that described limiting component is held in the outer surface against camshaft bearing.