CN2739365Y

CN2739365Y - Engine decompression device

Info

Publication number: CN2739365Y
Application number: CN 200420080450
Authority: CN
Inventors: 肖享琳
Original assignee: Wuxi Kipor Power Co Ltd
Current assignee: Wuxi Kipor Power Co Ltd
Priority date: 2004-10-19
Filing date: 2004-10-19
Publication date: 2005-11-09
Anticipated expiration: 2014-10-19

Abstract

The utility model relates to an engine decompression device fixed on the camshaft timing gear of oil engine belonging to the technical field of dynamic devices. The swinging arm assembly and the shifting fork assembly are fixed in the groove of the camshaft timing gear by axle pins. A relief spring is connected with the swinging arm assembly and the shifting fork assembly. An arc groove arranged on the end face of the camshaft timing gear communicates with an exhaust cam. A pressure reducing shaft is connected with the swinging arm and extends out of the arc to the exhaust cam. The utility model with simple, compact and reasonable structure greatly increases rotational inertia, effectively ensures the decompression process of the pressure reducing shaft and obviously improves the starting effect, being adequate for the engine with smaller compression ratio as well as satisfying the starting request of the engine with bigger compression ratio with automatic efficient decompression process.

Description

Decompression mechanism in engine

Technical field

The utility model relates to a kind of decompression mechanism in engine, specifically, is used for fixing on the camshaft timing gear of diesel engine, belongs to field of power equipment technology.

Background technique

Before the utility model is made, in prior art, present more general decompression mechanism in engine, decompressor as 186 diesel engines, the type decompressor decompression shaft is fixed on the cylinder head cover by pin and relief spring, thereby to be long arm ends of utilizing decompression shaft to depress rocking arm push valve open realizes decompression for they.There is following problem in this kind device: 1, decompression shaft section angle required precision height, and difficulty of processing is big; 2, the relief spring pretightening force is wayward; 3, retraction stroke is influenced by many places parts such as decompression shaft, cylinder head cover, valve rocker, pad; Need use the manual depression decompression handle when 4, starting, and the angle that decompression handle is depressed is suitable, user's operation easier is big; 5, decompression shaft and the easy oil leakage of cylinder cowl junction.

The decompressor of the publication number CN1188184A that Patent Office of the People's Republic of China announces, its part consists of centrifugal weight, pivot and operative pin, and the three connects with individual wire.This apparatus structure is simple and realized automatic effect of easing stress.There is following problem in this kind device: 1, relief spring adopts individual wire, and active force is little, and effect of easing stress is poor; 2, relief spring props up arm portion and is entangled on the centrifugal weight poor reliability, easily inefficacy; 3, centrifugal weight slides in the relief cam axial trough in this device, and relief cam axle jack-up action of cam power is little, can only start the motor that compression ratio is less or discharge capacity is less.

Therefore the unreasonable effect of easing stress that causes in the practical application of this apparatus structure design is undesirable, and is only applicable to the little defectives such as motor of compression ratio.

Summary of the invention

The purpose of this utility model is to overcome above-mentioned deficiency, thereby provides a kind of simple, compact and reasonable for structure; Can significantly improve startability, be suitable for the big decompression mechanism in engine of compression ratio simultaneously.

Main solution of the present utility model is achieved in that

The utility model adopts swing arm 1 and pull-fork assembly 5 to be fixed in camshaft timing gear 20 grooves 26 by

pivot pin

17,18, relief spring 9 is connected with pull-fork assembly 5 with swing arm 1, be shaped on arc groove 23 and communicate with exhaust cam 25 on camshaft timing gear 20 end faces, decompression shaft 12 links to each other with swing arm 1 and stretches out circular arc 23 to exhaust cam 25.Have square groove 3,4 in swing arm 1, linking to each other with pull-fork assembly boss 6 by square groove 3 drives pull-fork assembly 5 rotations, increases rotary inertia greatly, effectively guarantees the retraction stroke of decompression shaft 12.This decompressor has significantly improved the startup effect, is not only applicable to the less motor of compression ratio, satisfies the startup requirement of big compression ratio engine simultaneously.Decompression shaft 12 rotates between the primary importance and the second place, forms a very little rise part (retraction stroke) at primary importance decompression shaft 12 near above-mentioned cam base circle 24, plays decompression; By the centrifugal rotation of swing arm 1 and pull-fork assembly 5, decompression shaft 12 forwards Fig. 4 second place B to by Fig. 2 primary importance A, and rising, it is partially retracted to rise.Therefore obtain an automatical and efficient decompression process.

Compared with the prior art the utility model has the following advantages:

The utility model is simple, compact and reasonable for structure; Can increase rotary inertia greatly, effectively guarantee the retraction stroke of decompression shaft; Can significantly improve the startup effect, not be only applicable to the less motor of compression ratio, satisfy the startup requirement of big compression ratio engine simultaneously, have automatical and efficient decompression process.

Description of drawings

Fig. 1 is the utility model decompressor major component front view.

Fig. 2 is the A camshaft timing gear front view when decompressor is in primary importance A of Fig. 3 in the utility model.

Fig. 3 is the 2-2 line sectional drawing of Fig. 2 in the utility model.

Fig. 4 is the B camshaft timing gear front view when decompressor is in second place B of Fig. 5 in the utility model.

Fig. 5 is the 4-4 line sectional drawing of Fig. 4 in the utility model.

Embodiment

Embodiment during following the utility model is incited somebody to action in conjunction with the accompanying drawings is further described:

The utility model mainly comprises a camshaft timing gear 20, a pair of around

pivot pin

17,18, the swing arm 1 of rotating and pull-fork assembly 5, a decompression shaft 12 that rotates along with swing arm 1 and rotate in accompanying drawing 1-5.Camshaft timing gear 20 and camshaft 19 are as a whole, being shaped on arc groove 23 on camshaft timing gear 20 end faces communicates with exhaust cam 25, decompression shaft 12 links to each other with swing arm 1 and stretches out circular arc 23 to exhaust cam 25, two pin-and-

holes

21,22 are arranged in the camshaft timing gear groove 26, above-mentioned groove 26 is surrounded by camshaft timing gear interior edge face 27 and axle sleeve back shaft 28, and decompressor is arranged in the groove 26.

Swing arm 1 and pull-fork assembly 5 are fixed in camshaft timing gear 20 grooves 26 by

pivot pin

17,18 in the decompressor, and swing arm 1 square groove 3 links to each other with pull-fork assembly boss 6, and pull-fork assembly 5 is welded together by decompression shift fork 7 and centrifugal weight 8.

Decompression shaft 12 puts in camshaft timing gear arc groove 23 interior ends 14 and terminates near the exhaust cam 25, and the other end 15 of band pin is near axle sleeve 29 end faces, and pin 16 is contained in the swing arm square groove 4, along with swing arm 1 is rotated together.Swing arm 1 and pull-fork assembly 5 are swung between primary importance A and second place B, and the second place and primary importance separate the formation several angle, and swing arm 1 and pull-fork assembly 5 rotate in timing gear groove 26 around pivot pin 17,18.Swing arm 1 and pull-fork assembly 5 are when primary importance A, and decompression shaft section 13 stretches out exhaust cam 25 basic circle faces 24, form a very little rise part.Swing arm 1 and pull-fork assembly 5 rise partially retractedly when second place B, and decompression shaft section 13 is parallel with cam base circle face 24.

Relief spring 9 is an extension spring, pressing spring 9 is connected with pull-fork assembly 5 with swing arm 1, the long-armed semicircle shackle 11 of one end hooks in the aperture of swing arm 1, and the long-armed semicircle shackle 10 of the other end hooks in the aperture of pull-fork assembly 5, makes swing arm 1 and pull-fork assembly 5 be in primary importance A; It is movable that swing arm 1 is connected with

pivot pin

17,18 with pull-fork assembly 5, swing arm 1 is fixed in the timing gear groove 26, can rotate around

pivot pin

17,18 centers, swing arm 1 drives pull-fork assembly 5 by square groove 3 and rotates together, when swing arm exterior edge face 2 during near timing gear interior edge face 27, swing arm 1 and pull-fork assembly 5 are in second place B.

Operating process of the present utility model is described below:

When motor at the state of shutting down, swing arm 1 and pull-fork assembly 5 are under the effect of relief spring 9 biasing forces, as Fig. 2, shown in Figure 3, swing arm 1 and pull-fork assembly 5 etc. lean against on the axle sleeve back shaft 28, remain on primary importance A, decompression shaft section 13 stretches out the aperture and forms very little rise part near exhaust cam 25.

As want ato unit, pulling operation recoil starter rotates bent axle, upwards promote push rod, form the engine compresses stroke, at this moment decompression shaft 12 rises part jack-up tappet, by push rod and adjustment screw rocking arm is swung around pitman arm shaft, the compression valve spring is opened exhaust valve, and the engine chamber partial pressure is released, alleviate the rotation load of bent axle, start running thereby finish.

During engine start, when camshaft timing gear 20 rotating speeds are brought up to predetermined value or are surpassed, swing arm 1 and pull-fork assembly 5 rotate together round

pivot pin

17,18, because the centrifugal force that acts on swing arm 1 and the pull-fork assembly 5 increases, overcome the predetermined load of relief spring 9, thereby make swing arm 1 and pull-fork assembly 5 turn to second place B.As Fig. 4, shown in Figure 5,, make decompression shaft section 13 parallel with cam base circle face 24 so decompression shaft 12 very little rises are partially retracted.Therefore motor is in running, and exhaust valve is not subjected to the interference of decompression shaft 12 according to 25 body contours energy of exhaust cam normal switch.

Claims

1, a kind of decompression mechanism in engine, it is characterized in that adopting swing arm (1) and pull-fork assembly (5) to be fixed in camshaft timing gear (20) groove (26) by pivot pin (17,18), relief spring (9) is connected with pull-fork assembly (5) with swing arm (1), be shaped on arc groove (23) and communicate with exhaust cam (25) on camshaft timing gear (20) end face, decompression shaft (12) links to each other with swing arm (1) and stretches out circular arc (23) to exhaust cam (25).

2, decompression mechanism in engine according to claim 1 is characterized in that the described groove (3,4) that has in swing arm 1.

3, decompression mechanism in engine according to claim 1 is characterized in that described pull-fork assembly (5) is connected with centrifugal weight (8) by decompression shift fork (7).