CN201165884Y

CN201165884Y - Small-sized general purpose petrol engine of four-stroke overhead camshaft

Info

Publication number: CN201165884Y
Application number: CNU2007200271916U
Authority: CN
Inventors: 冯立群; 兰青
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-09-02
Filing date: 2007-09-02
Publication date: 2008-12-17
Anticipated expiration: 2017-09-02

Abstract

The utility model relates to a four-stroke overhead camshaft small gasoline engine for general purposes, composed of a cylinder head assembly, a distribution mechanism assembly, a cylinder body assembly, a piston assembly, a crankshaft connecting rod assembly, a crankcase assembly, an ignition system and a lubricating circulation system. The four-stroke overhead camshaft small gasoline engine for general purposes is designed on the base of the existing technical products, one distributing cam is changed into two, one is an inlet cam controlling opening and closing of an intake valve and the other is an outlet cam controlling the opening and closing of an exhaust cam, the two cams are arranged on the same shaft in design to form a distribution camshaft which is directly fixedly mounted inside a cylinder head of the cylinder head assembly, simultaneously two valve push rod through holes on the cylinder head assembly and the cylinder body assembly are improved and designed to be an elongated passage which is convenient for the distribution mechanism assembly to pass through, further a cam follower and a valve push rod are saved, and thereby the four-stroke overhead camshaft small gasoline engine for general purposes has the advantages of compact distribution mechanism, reliable timing transmission and operation, reducing the intake resistance, high efficiency, less parts, reducing the failure rate and favoring for increasing the high-speed performance of the gasoline engine.

Description

Four stroke top camshaft small utility gasoline engine

Affiliated technical field

The utility model relates generally to reciprocating piston Spark ignition type petrol engine, relates in particular to a kind of four stroke top camshaft Small Universal gas and oil machine.

Background technique

Prior art products all is to adopt Overhead valve distribution device assembly.This distribution device assembly is by joining the vapour cam, intake valve, exhaust valve, valve actuating push rod, valve lever pin, valve spring, cam follower, timing transmission gearwheel, the timing driving pinion is formed, valve cam and timing transmission gearwheel are one, be installed in the crankcase body in the crankcase assembly, use a valve cam to control air inlet and two kinds of functions of exhaust, a valve cam control air intake-exhaust, performance valve cam usefulness there is more restriction, the appearance curve of valve cam limits the distribution device assembly can only adopt less valve overlap, during less valve overlap only is applicable to, slow-revving petrol engine.Four-stroke gasoline engine is meant that the crank assemblby of petrol engine changes two and changes the motor of finishing four stroke procedure, and four strokes are respectively by air inlet, and compression breaks out, and four kinds of difference in functionalitys of exhaust are formed.Prior art products includes cylinder cover complement, institution of distributing gas's assembly, and the cylinder block assembly, piston assembly, crank assemblby, connecting rod ASSY, crankcase assembly, ignition system, lubricating circulatory system is formed.Cylinder cover complement is by cylinder head, cylinder head cover, and spark plug is formed, and has the waste gas that produces after intake duct and air outlet flue are used for entering of burning mixture and break out work done on the cylinder head and discharges.Valve guide bushing is installed on intake and exhaust port, play the effect of guide-localization when being used for to the upper and lower motion of valve, the firing chamber of four-stroke gasoline engine is shallow hemisphere, intake valve, two valves of exhaust valve have occupied the major part of firing chamber, spark plug is installed in a side of firing chamber, spark plug is one of constituent element of ignition system, its effect is to light the incendivity mixed gas in the suitable moment to make it produce power, also has two porthole push rods to be convenient to valve actuating push rod by the hole in cylinder head and therefrom passes through.；；；；；；；；；；；；；；；；；；；；；；；；；；；；；；；；；；；；；；；；；；；；；；；；；，。Crank assemblby be divided into two kinds a kind of for split type crank assemblby, a kind of is the integral one-piece crankshaft assembly, split type crank assemblby is by a left side, right crankshaft, the crank pin crankshaft bearing is formed, the integral one-piece crankshaft assembly is by integral one-piece crankshaft, crankshaft bearing is formed, connecting rod ASSY also is divided into two kinds, a kind of is split type connecting rod ASSY, a kind of is the integrated type connecting rod ASSY, split type connecting rod ASSY is by connecting rod, connecting rod macropore bearing shell, the connecting rod macropore is formed with mounting screw, the integrated type connecting rod ASSY is by connecting rod, the connecting rod macropore is formed with needle bearing, the integral one-piece crankshaft assembly is joined split type connecting rod ASSY, and split type crank assemblby is joined the integrated type connecting rod ASSY.Crank assemblby, the effect of connecting rod ASSY is to connect piston assembly, the linear reciprocating motion of piston assembly become rotatablely move, and outputting power, end at crank assemblby is equipped with the timing driving pinion, crankcase assembly is by a left side, right crankcase, left and right sides crankcase cover is formed, the timing driving pinion that timing transmission gearwheel is installed in the crankcase body and crank assemblby one end is installed intermeshes to rotate petrol engine is run well, ignition system is by magnetogenerator, contactless ignitor, spark plug, high-voltage ignition coil is formed, the profit circulatory system is by oil storage, the lubrication oil circulation passage is formed, oil storage also claims oil sump, be located at the inner lower half portion of crankcase assembly, the lubrication oil circulation passage is distributed in cylinder cover complement, the cylinder block assembly, crankcase assembly inside.Prior art products is because institution of distributing gas's assembly circuit is long, valve actuating push rod rigidity is poor, the inertial force that pumps is big, responsive to temperature is easily produced thermal expansion, valve cam is difficult to accomplish the accurate control to intake valve steam discharge door open and close Best Times, makes prior art products can only be applicable to many deficiencies such as middle and slow speed of revolution using scope.

Summary of the invention

For overcoming the deficiency of prior art products, the utility model provides a kind of four stroke top camshaft small utility gasoline engine, and this machine has been done distribution device and improved design, makes the higher rotating speed of gasoline functional adaptation.

The technological scheme that the utility model solves the prior art products deficiency is: the vapour cam of joining in institution of distributing gas's assembly in the prior art products is designed to two by an improvement, one is intake cam, the open and close of control intake valve, open and close for exhaust valve control exhaust valve, two cam design become distribution cam axle on the same axis, and distribution cam axle directly is fixed on cylinder head inside in the cylinder cover complement, simultaneously with cylinder cover complement, two valve actuating push rods on the cylinder block on the assembly improve by the hole and are designed to a rectangular passage, so that the distribution device assembly therefrom passes through, cam follower and valve actuating push rod have been cancelled.Four stroke top camshaft small utility gasoline engine described in the utility model is to improve to design on the prior art basis, system synthesis and the component that utilize the mature and reliable of prior art products as much as possible, include cylinder cover complement, the distribution device assembly, the cylinder block assembly, piston assembly, crank assemblby, connecting rod ASSY, crankcase assembly ignition system lubricating circulatory system is formed, four-stroke gasoline engine is by air inlet, compression, outburst, four strokes of exhaust constitute, change this process of finishing by crank assemblby rotation two, cylinder cover complement is by cylinder head, cylinder head cover, spark plug is formed, on cylinder head, have intake duct, two air flues of air outlet flue, one end of air flue is located in the firing chamber of cylinder head bottom, the other end is located at the side of cylinder head, and the firing chamber is a shallow hemisphere.Intake valve, exhaust valve has occupied the major part of firing chamber, spark plug is installed in a side in the firing chamber, on the gas port of firing chamber one end air valve seat ring is installed, the sealing that is used for valve prevents gas leakage, the shape of valve resembles mushroom, front end abuts against with air valve seat ring, the back is a thin bar, valve guide bushing is installed on air flue, and valve stem therefrom passes through, on valve, under play the guide-localization effect when moving, design has a rectangular hole of passing through on the cylinder head, be convenient to the timing driving mechanism and therefrom pass through, also design has distribution cam axle to install and fix seat in cylinder head, is used to install and fix and joins the vapour camshaft.The distribution device assembly is by distribution cam axle, intake valve, exhaust valve, valve rocker, valve spring, pitman arm shaft, timing transmission gearwheel or hinge wheel, timing driving pinion or minor sprocket, the timing drive chain is formed, owing to taked the overhead camshaft design, makes the timing driving mechanism can continue to adopt the timing gear transmission also can select to use the big minor sprocket of timing, chain transmission outward, the sprocket wheel chain adapts to the long distance transmission, in light weight, noise is low, and processing cost is low.The distribution cam axle design has two cams, control intake valve respectively separately, the switching time of exhaust valve, the shape of cam resembles a peach, the highest position of projection is the peach point, unpolarized position is basic circle, difference in size between peach point and the basic circle is a valve lift, cam is important components on the petrol engine, its appearance curve has determined the degree of accuracy of intake valve exhaust valve switching time, and then influence the runnability of petrol engine, position, peach tip is with an end jack-up of valve rocker during cam rotation, the other end of valve rocker is pressed on the top of valve stem, because leverage, the other end of valve rocker is with valve, valve spring is depressed simultaneously and is made valve opening, and using the cam profile of valve rocker is the asymmetric shape in the left and right sides, the peach point that is cam is not on the elongation line of cam base circle central cross line, and this cam profile design is that the point of contact at rocking arm two ends when using valve rocker for adaptation will produce different separately side-play amounts.End design and installation at distribution cam axle has timing transmission hinge wheel, in timing transmission hinge wheel back and the other end design two rolling bearings are arranged, distribution cam axle is gone slick, the cylinder block assembly is by cylinder block, distribution device is formed by the hole, distribution device is an oblong channels by the hole, so that the timing drive chain in the distribution device assembly passes through, simultaneously with cylinder head on pass through the same double lubrication oil circulation drainback passage of doing in hole, length and width by the hole on length and width by the hole and the cylinder head are identical, if adopt the transmission of timing drive chain, by also wanting design and installation timing drive chain Fastening mechanism inside and outside the hole, Fastening mechanism is made up of two tensioner bars and a tensioner bar automatic control regulator, the tensioner bar is a resilient sheet metal of long strip, the outside is surrounded by one deck rubber, two tensioner bars are pressed in the both sides of timing drive chain respectively, tensioner bar automatic control regulator is a cylindrical component, endoporus is equipped with slender axles, a spring is equipped with in the outside of axle, the slender axles front end has a slice pressing plate to be pressed in a tensioner bar outside, because the pressure effect of spring, make pressing plate tightly suppress the timing drive chain and remain certain elasticity, reach self-regulating effect.Automatic control regulator is installed in cylinder block assembly distribution device by the outside, hole, piston assembly is made up of piston, piston ring, wrist pin, the four-stroke piston length is very short, piston ring has three roads, twice are compression ring, are used to prevent gas leakage, are installed in two annular grooves of piston upper end, the 3rd road is an oil ring, is used to prevent that lubricant oil from entering produces carbon deposit with combustion gas blending burning in the cylinder cover chamber of piston head and damage parts and cause exhaust pollution.Crank assemblby be divided into two kinds a kind of be split type crank assemblby, a kind of is the integral one-piece crankshaft assembly, split type crank assemblby is made up of left and right crankshaft, crank pin, crankshaft bearing, the integral one-piece crankshaft assembly is made up of integral shaft, crankshaft bearing, connecting rod ASSY also is divided into two kinds: a kind of is split type connecting rod ASSY, a kind of is the integrated type connecting rod ASSY, split type connecting rod ASSY is made up of split type connecting rod, connecting rod bearing shell, split connecting rod mounting screw, the integrated type connecting rod ASSY is by monolithic linkage, and connecting rod macropore needle bearing is formed.Split type bent axle is joined the integrated type connecting rod ASSY, the integral one-piece crankshaft assembly is joined split type connecting rod ASSY, crank assemblby one end can be installed the timing driving pinion, timing transmission minor sprocket also can be installed, the number of teeth of timing driving pinion or minor sprocket is compared with the number of teeth of timing transmission gearwheel or hinge wheel all will lack one times, be that crank assemblby changes two commentaries on classics, distribution cam axle is goed around, to guarantee the normal operation of four-stroke gasoline engine, crank assemblby, the effect of connecting rod ASSY is to connect piston assembly and crank assemblby, the linear reciprocating motion of piston assembly is become the also outputting power that rotatablely moves, crank assemblby and distribution cam axle are arranged in parallel, intake duct, air outlet flue and distribution cam axle are arranged vertically.Crankcase assembly is by left and right sides crankcase body, and left and right crankcase cover is formed, and ignition system is by contactless ignitor, and magnetogenerator, spark plug, high-voltage ignition coil are formed, and lubricating circulatory system is by oil storage, and the lubrication oil circulation passage is formed, and oil storage also claims oil sump.Be positioned at crankcase lower half portion, the lubrication oil circulation passage is distributed in cylinder cover complement, cylinder block assembly, crankcase assembly inside.

Owing to adopt such scheme, the utility model makes the distribution device compactness because of the distribution cam axle design and installation in cylinder head, two cam design make valve switch obtain Best Times and accurately control, the timing transmission is reliable, intake resistance is low, the efficient height, component reduce rate of fault and reduce, and help improving the petrol engine high speed performance.

Description of drawings:

Below in conjunction with drawings and Examples the utility model is described further.

Fig. 1 is first embodiment's of the utility model a longitudinal section structure sketch.

Fig. 2 is second embodiment's of the utility model a longitudinal section structure sketch.

Among the figure 1, cylinder head, 2, cylinder head cover, 3, timing transmission hinge wheel, 4, timing drive chain, 5, join the vapour camshaft, 6, admission door rocking arm, 7, exhaust valve rocker arm, 8, steam discharge door, 9, spark plug, 10, the cylinder block assembly; 11, piston assembly, 12, crank assemblby, 13, timing transmission minor sprocket, 14, left crankcase, 15, right crankcase, 16, the left crankcase lid, 17, right crankcase cover, 18, magnetogenerator, 19, connecting rod ASSY, 20, join vapour camshaft bearing, 21, intake cam, 22, exhaust cam, 23, intake valve, 24, valve guide bushing, 25, intake duct, 26, air outlet flue, 27, valve spring.

Embodiment

In first embodiment shown in Figure 1, distribution cam axle (5) is gone up position, peach tip that design has intake cam (21), exhaust cam (a 22) cam rocking arm is pressed in an end jack-up on the cam, because the waste gas that the leverage of rocking arm; the other end of rocking arm is depressed valve, the combustion gas of valve opening fresh mix are passed through after intake duct (25) or the burning work done is discharged through air outlet flue (26).Intake valve (23) exhaust valve (8) cuts out under the effect of valve spring (27), and the effect of valve guide bushing (24) is to be used for the guide-localization effect of intake valve (23) exhaust valve (8) when opening or closing.

In second embodiment shown in Fig. 2, distribution cam axle (5) is fixed in the cylinder head (1), at an end of joining vapour camshaft (5) timing being installed phoresys hinge wheel (3) and at an end of crank assemblby (12) timing transmission minor sprocket (13) is installed and relies on timing drive chain (4) to be connected, by crank assemblby (12) rotary driving, joining has (22) two cams of intake cam (21) exhaust cam also along with transmission on the vapour camshaft (5), make intake rocker (6) exhaust rocker arm (7) that is pressed on the cam wheel rise successively or fall; the intake valve that the rocking arm the other end is being pressed (23) exhaust valve (18) equally also is depressed and returns under the effect of valve spring (27), make alternately opening and closing of intake valve (23) exhaust valve (8).

Claims

1, a kind of four stroke top camshaft small utility gasoline engine, by cylinder head (1), cylinder head cover (2), timing transmission hinge wheel (3), timing drive chain (4), join vapour camshaft (5), cylinder block assembly (10), crank assemblby (12), left crankcase (14), right crankcase (15), left crankcase lid (16), right crankcase cover compositions such as (17), it is characterized in that: joining has (22) two cams of intake cam (21) exhaust cam to control intake valve (23) exhaust valve (8) open and close respectively on the vapour camshaft (5), distribution cam axle is installed in cylinder head (1) inside.