CN201255018Y - Cam shaft automatic decompressor mechanism for engine - Google Patents
Cam shaft automatic decompressor mechanism for engine Download PDFInfo
- Publication number
- CN201255018Y CN201255018Y CNU2008200999504U CN200820099950U CN201255018Y CN 201255018 Y CN201255018 Y CN 201255018Y CN U2008200999504 U CNU2008200999504 U CN U2008200999504U CN 200820099950 U CN200820099950 U CN 200820099950U CN 201255018 Y CN201255018 Y CN 201255018Y
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- CN
- China
- Prior art keywords
- centrifugal
- camshaft
- mandrel
- engine
- exhaust cam
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- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Abstract
The utility model discloses an automatic decompression mechanism of an engine camshaft. A camshaft is provided with a driven sprocket and an exhaust cam; the surface of the camshaft is provided with an axial groove which reaches the exhaust cam; one end of a core shaft is fixed with a centrifugal block; the other end thereof penetrates through the driven sprocket, extends into the axial groove and reaches the exhaust cam; the core shaft can rotate when driven by the centrifugal block; because the core shaft can cause different lift ranges in the rotating process, the core shaft can be higher or lower than the base circle of the exhaust cam; when the core shaft is higher than the base circle, the exhaust valve can be opened; and the centrifugal block is provided with a return spring. The utility model has the advantages of simple and compact structure, easy installation and flexible combination for operation, and can reduce the noise generated by the cylinder head. The performance is reliable. When the engine is started, the utility model can achieve the effect of automatic decompression; after the engine is started, the utility model can normally operate again.
Description
Technical field
Automatic decompression device when the utility model relates to a kind of startup of being located on the engine cam, this camshaft has automatic pressure-reducing function to the cylinder internal air pressure when engine start, thereby is beneficial to engine start.
Background technique
Engine piston can stop, and is to reach a balance because the piston two ends are stressed.Behind engine misses, because inertia, the crank-connecting rod piston mechanism also will be proceeded back and forth to move up and down.Cylinder head valve normal switch, obviously when being in compression stroke, because the inlet and outlet door is closed, cylinder pressure can not discharge reduction voluntarily.Position cylinder internal air pressure this moment that piston stops is higher relatively.Next circulation directly starts if the cylinder internal air pressure is not reduced pressure when motor need start moment, will be that very difficulty, particularly pin start, and is especially all the more so to large-duty engine.Therefore, the available engine major part all is equipped with the startup mechanism of decompressor, using the more startup mechanism of decompressor at present mainly is " one-way element " formula camshaft decompression mechanism, this mechanism of decompressor relates to one-way element and one-way element positioning supports, its deficiency is that installing space is had certain requirement, and the position is too narrow can't install.
The model utility content
At the prior art above shortcomings, the purpose of this utility model provides a kind of compact structure, be convenient to install, the engine cam automatic decompression device of reliable performance.
The technical solution of the utility model is achieved in that the engine cam automatic decompression device, comprise camshaft, driven sprocket and exhaust cam are installed on camshaft, it is characterized in that: it also comprises centrifugal and mandrel, the camshaft surface is provided with and reaches the axial groove of exhaust cam, mandrel one end and centrifugal are fixing, the other end passes to enter from driven sprocket and arrives the exhaust cam position in the axial groove, mandrel is rotatable under centrifugal drive, mandrel has different lifts in rotary course can make mandrel or be higher or lower than the exhaust cam basic circle, open exhaust valve when being higher than the exhaust cam basic circle, centrifugal is provided with the return torsion spring.
On camshaft, be provided with the equilibrium block that is used for equilibrium centrifugation piece rotary inertia.
Described centrifugal is provided with limited post, and limited post is provided with plastic sheath, and limited post stretches in the restraining groove on the driven sprocket, and restraining groove is corresponding with the limited post running orbit.
It also comprises the postive stop baffle that is fixed on the camshaft, and postive stop baffle is positioned at the centrifugal outside and is used to limit the centrifugal angle of throwing away, and postive stop baffle and centrifugal contacting point are provided with the reducing noise rubber piece.
The utility model adopts centrifugal to cooperate the structure of mandrel to realize decompression automatically.When the motor proper functioning, the camshaft high speed rotating utilizes centrifugal force, overcomes the torsion of return torsion spring, throws away for centrifugal, and the mandrel that drives simultaneously on centrifugal rotates a certain angle, and makes the recessed camshaft basic circle of mandrel, then the rocking arm proper functioning.Behind engine misses, camshaft speed reduces gradually until stopping, and centrifugal of this moment is under the effect of return torsion spring power, get back to initial position, simultaneously the mandrel on centrifugal is also along with turning over several angle, this moment mandrel a little more than the exhaust cam basic circle, back down exhaust valve slightly, open certain angle when causing exhaust valve closing at this moment, when next ato unit, not tight because of exhaust valve closing, then inner pressure of air cylinder reduces, be convenient to start, play the effect of decompression.And the design of equilibrium block can be guaranteed the camshaft running steadily.
The utility model is simple and compact for structure, installs easily, and the flexible combination of turning round reduces the cylinder head noise, reliable performance.
Description of drawings
Fig. 1-the utility model structural representation;
Fig. 2-centrifugal block structural diagram;
Fig. 3-driven sprocket structural drawing;
Fig. 4-postive stop baffle structural drawing;
Fig. 5-equilibrium block and centrifugal mounting structure figure on driven sprocket.
Embodiment
The utility model is described in further detail below in conjunction with accompanying drawing.
Referring to Fig. 1, as can be seen, the utility model engine cam automatic decompression device comprises camshaft 1, centrifugal 2 and mandrel 3 from the figure, timing driven sprocket 4 and exhaust cam 5 are installed on camshaft 1, and camshaft 1 surface is provided with and reaches the axial groove of exhaust cam.Mandrel 3 one ends and centrifugal 2 are fixing, and the other end passes to enter from driven sprocket 4 and arrives exhaust cam 5 positions in the axial groove.Mandrel 3 is rotatable under centrifugal 2 drive, because mandrel is chamfered edge structure or cam structure at exhaust cam basic circle position, so mandrel 3 has different lifts and can make mandrel or be higher or lower than the exhaust cam basic circle in rotary course, open exhaust valve when being higher than the exhaust cam basic circle.Be provided with return torsion spring 6 for centrifugal 2, after the centrifugal force that makes centrifugal rotation disappeared, the return torsion spring can make centrifugal return.Described centrifugal 2 is provided with limited post 7 (see figure 2)s, and limited post 7 stretches in the restraining groove 8 on the driven sprocket 4, and restraining groove 8 is corresponding with limited post 7 running orbits, and driven sprocket 4 structures are seen Fig. 3.Limited post 7 is provided with plastic sheath 9, its objective is to reduce noise and buffering, the flexible combination when restraining groove 8 slides that makes centrifugal 2.
Because the speed of camshaft 1 running is quite high, so rotary inertia that must have an equilibrium block to come the equilibrium centrifugation piece to bring also, make the camshaft running steadily, designing on camshaft 1 by driven sprocket 4 based on this utility model has a fixing equilibrium block 10, sees Fig. 5 simultaneously.
Excessive and exceed the torque range of return torsion spring 6 in order to prevent to throw away for centrifugal 2 angle, the utility model also has additional the postive stop baffle 11 that is fixed on the camshaft 1, postive stop baffle 11 is positioned at centrifugal 2 outside and is used to limit centrifugal 2 angle of throwing away, postive stop baffle 11 is provided with block rubber 12 with centrifugal 2 contacting point, its purpose be equally buffering and reduce in conjunction with the time noise, make both flexible combinations, postive stop baffle 11 structures are seen Fig. 4.
The utility model working procedure is as follows:
When the motor proper functioning, camshaft 1 high speed rotating utilizes centrifugal force, overcome the torsion of return torsion spring 6, throw away for centrifugal 2, the mandrel 3 that drives simultaneously on centrifugal 2 rotates a certain angle, make mandrel 3 recessed exhaust cam basic circle, then exhaust valve rocker arm proper functioning.When throwing away for centrifugal 2, the limited post 7 on centrifugal slides along restraining groove 8 tracks on the timing driven sprocket, and it throws angle away by postive stop baffle 11 restrictions.Simultaneously, equilibrium block 10 is also thrown away because of centrifugal force, reaches the purpose that the equilibrium centrifugation piece rotates the rotary inertia that brings.
Behind engine misses, camshaft 1 rotating speed reduces gradually until stopping, and centrifugal 2 of this moment got back to initial position under the effect of camshaft return torsion spring power, simultaneously the mandrel 3 on centrifugal 2 is also along with turning over several angle, make mandrel protrude the exhaust cam basic circle, open certain angle when causing exhaust valve closing at this moment, when next ato unit, because of exhaust valve closing not tight, then inner cylinder pressure reduces, and is convenient to start, and plays the effect of decompression.
Claims (4)
1, the engine cam automatic decompression device, comprise camshaft (1), driven sprocket (4) and exhaust cam (5) are installed on camshaft (1), it is characterized in that: it also comprises centrifugal (2) and mandrel (3), camshaft (1) surface is provided with and reaches the axial groove of exhaust cam (5), mandrel (3) one ends and centrifugal (2) are fixing, the other end passes to enter from driven sprocket (4) and arrives exhaust cam (5) position in the axial groove, mandrel (3) is rotatable under the drive of centrifugal (2), mandrel (3) has different lifts in rotary course can make mandrel or be higher or lower than the exhaust cam basic circle, open exhaust valve when being higher than the exhaust cam basic circle, centrifugal (2) are provided with return torsion spring (6).
2, engine cam automatic decompression device according to claim 1 is characterized in that: be provided with the equilibrium block (10) that is used for equilibrium centrifugation piece (2) rotary inertia on camshaft (1).
3, engine cam automatic decompression device according to claim 1 and 2, it is characterized in that: described centrifugal (2) are provided with limited post (7), limited post (7) is provided with plastic sheath (9), limited post (7) stretches in the restraining groove (8) on the driven sprocket (4), and restraining groove (8) is corresponding with limited post (7) running orbit.
4, engine cam automatic decompression device according to claim 3, it is characterized in that: it also comprises the postive stop baffle (11) that is fixed on the camshaft (1), postive stop baffle (11) is positioned at centrifugal (2) outside and is used to limit the angle that centrifugal (2) are thrown away, and postive stop baffle (11) is provided with reducing noise rubber piece (12) with centrifugal (2) contacting point.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008200999504U CN201255018Y (en) | 2008-09-09 | 2008-09-09 | Cam shaft automatic decompressor mechanism for engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008200999504U CN201255018Y (en) | 2008-09-09 | 2008-09-09 | Cam shaft automatic decompressor mechanism for engine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201255018Y true CN201255018Y (en) | 2009-06-10 |
Family
ID=40738334
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU2008200999504U Expired - Lifetime CN201255018Y (en) | 2008-09-09 | 2008-09-09 | Cam shaft automatic decompressor mechanism for engine |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201255018Y (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111042890A (en) * | 2019-12-25 | 2020-04-21 | 重庆隆鑫机车有限公司 | Two-way positioning pressure reducing valve and engine |
| CN114135359A (en) * | 2021-11-30 | 2022-03-04 | 江门市大长江集团有限公司 | Engine and pressure reducing cam catch structure |
-
2008
- 2008-09-09 CN CNU2008200999504U patent/CN201255018Y/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111042890A (en) * | 2019-12-25 | 2020-04-21 | 重庆隆鑫机车有限公司 | Two-way positioning pressure reducing valve and engine |
| CN114135359A (en) * | 2021-11-30 | 2022-03-04 | 江门市大长江集团有限公司 | Engine and pressure reducing cam catch structure |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term |
Granted publication date: 20090610 |
|
| CX01 | Expiry of patent term |