Camshaft structure of motorcycle engine and engine

Abstract

The utility model belongs to the technical field of motorcycle engines, and particularly discloses a motorcycle engine cam shaft structure and an engine, the motorcycle engine cam shaft structure comprises a cam shaft, and an exhaust cam is arranged on the cam shaft; the flange plate is arranged on the cam shaft, a throwing block is hinged to the side, away from the exhaust cam, of the flange plate, a valve element shaft is rotationally connected to the cam shaft, the throwing block can drive the valve element shaft to rotate, and a limiting assembly used for fixing the valve element shaft is arranged on the flange plate. According to the utility model, the valve core shaft can be limited through the arranged limiting assembly, so that the displacement deviation of the valve core shaft in the movement process can be avoided, and in the normal operation process of an engine, the valve core shaft is prevented from excessively rotating or not rotating in place, so that a valve is opened in advance in the normal operation state of the engine; normal operation of the engine is ensured, and the combustion efficiency of the engine is guaranteed.

Description

TECHNICAL FIELD

[0001] The utility model relates to motorcycle engine technical field especially a kind of motorcycle engine camshaft structure and engine. BACKGROUND

[0002] Fuel combustion in the cylinder of motorcycle engine produces heat energy, which is converted into mechanical energy, and then drives the wheels of the motorcycle to rotate through the crankshaft, to realize the motorcycle driving. Because the space of motorcycle is limited, its engine has the advantages of small size and low noise.

[0003] In motorcycle engine, valve is an important component of engine, which is responsible for inputting air into engine and discharging exhaust gas after combustion. Valve includes intake valve and exhaust valve. Intake valve sucks air into engine to mix with fuel for combustion, and exhaust valve discharges exhaust gas after combustion and dissipates heat.

[0004] In prior art, when engine starts or single-cylinder motorcycle works at large displacement, it is difficult to start due to large internal pressure of cylinder. Therefore, the applicant proposes a kind of motorcycle engine camshaft structure and engine. SUMMARY

[0005] In view of the above-mentioned shortcomings of prior art, the purpose of the utility model is to provide a kind of motorcycle engine camshaft structure and engine, to solve the problem of difficult starting of motorcycle engine in prior art.

[0006] To achieve the above-mentioned purpose and other related purposes, the utility model provides a kind of motorcycle engine camshaft structure, which comprises a camshaft, and an exhaust cam is arranged on the camshaft.

[0007] A flange plate is arranged on the camshaft, and a weight is hingedly connected to the side of the flange plate away from the exhaust cam. A valve core shaft is rotatably connected to the camshaft, and the weight can drive the valve core shaft to rotate. A limiting assembly is arranged on the flange plate to limit the valve core shaft.

[0008] Optionally, the limiting assembly comprises a limiting block and a limiting bearing. The limiting block is arranged on the flange plate, and a clamping groove is arranged on the limiting block. A limiting groove is arranged on the camshaft along its axial direction. The clamping groove and the limiting groove form an annular space, and the limiting bearing is arranged in the annular space. The valve core shaft penetrates through the limiting bearing.

[0009] Optionally, the limiting block comprises a first limiting part and a second limiting part arranged continuously on the flange plate. A transition part is arranged between the first limiting part and the second limiting part, and the clamping groove is arranged on the transition part.

[0010] Optionally, the camshaft is provided with a mounting groove for mounting the valve core shaft, the mounting groove extends along the axial direction of the camshaft, the limiting groove is continuously arranged with the mounting groove, and at least a part of the mounting groove extends into the exhaust cam.

[0011] Optionally, the first limiting part is provided with a first boss, the second limiting part is provided with a second boss, the first boss and the second boss form a limiting space, the free end of the flyweight can rotate around the rotation center of the flyweight in the limiting space, the flyweight is provided with a fixing groove, and the first boss penetrates through the fixing groove.

[0012] Optionally, the valve core shaft is provided with a shifting rod, the shifting rod penetrates through the transition part and enters the fixing groove, and the shifting rod can swing in the overlapping area of the fixing groove and the limiting space under the driving of the flyweight.

[0013] Optionally, the first boss is provided with a first abutting part, the second boss is provided with a second abutting part, and the transition part is provided with a third abutting part, and the first abutting part, the second abutting part and the third abutting part are used for limiting the flyweight.

[0014] Optionally, the second limiting part is provided with a mounting part, and the camshaft is provided with a pin shaft penetrating into the mounting part.

[0015] Optionally, the reset spring is arranged on the flange plate and is used for resetting the flyweight.

[0016] The utility model also provides an engine comprising the engine camshaft structure.

[0017] As described above, the utility model provides a motorcycle engine camshaft structure and engine, has following beneficial effect:

[0018] (1) in the utility model, through setting flyweight, can when starting engine, fling open, synchronous drive valve core shaft rotation, after rotating a certain angle through the end of valve core shaft opens valve in advance, reduces the pressure of combustion chamber, is convenient for engine in just beginning starting.

[0019] (2) in the utility model, through setting valve core shaft, can make the pressure reduction in engine combustion chamber, for single cylinder engine, it can carry out greater displacement, is favorable to the performance of engine.

[0020] (3) The utility model discloses a limiting assembly is set up, can be limited to the valve core axle to can avoid the displacement deviation of valve core axle in the movement process, in the engine operation process, guarantee valve core axle to produce the influence to the valve, avoid the valve engine to open the valve in advance under the normal operation state, ensure the normal operation of engine, and the combustion efficiency of engine can improve. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The structure schematic diagram of an embodiment of the utility model is shown as follows:

[0022] Figure 2 The sectional view of an embodiment of the utility model is shown as follows:

[0023] Figure 3 The enlarged view of A in an embodiment of the utility model is shown as follows:

[0024] Figure 4 The structure schematic diagram of the camshaft in an embodiment of the utility model is shown as follows:

[0025] Figure 5 The structure schematic diagram of the flange plate in an embodiment of the utility model is shown as follows:

[0026] Figure 6 The front view of the flange plate in an embodiment of the utility model is shown as follows:

[0027] Figure 7 The sectional view of the flange plate in an embodiment of the utility model is shown as follows.

[0028] BRIEF DESCRIPTION OF DRAWINGS

[0029] Camshaft 1, exhaust cam 2, limiting groove 3, installation groove 4, flange plate 5, first limiting portion 6, second abutting portion 601, second limiting portion 7, transition portion 8, third abutting portion 801, clamping groove 9, limiting bearing 10, first boss 11, second boss 12, first abutting portion 1201, return spring 13, installation portion 14, flyweight 15, fixed groove 16, valve core axle 17, limiting pin 1701, plane 18, lever 19, pin shaft 20. DETAILED DESCRIPTION

[0030] The other advantages and effects of the utility model can be easily understood by the person skilled in the art from the content disclosed in the specification. The utility model can also be implemented or applied by another different specific embodiment, and each detail in the specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the utility model.

[0031] It is to be noted that the diagrams provided in the present embodiment only schematically illustrate the basic concept of the present application, and thus the diagrams only show the components related to the present application, rather than being drawn according to the number, shape and size of the components in actual implementation. The configuration, ratio, size, etc. shown in the diagrams attached to the present specification are only used to cooperate with the content disclosed in the present specification, so as to be understood and read by those skilled in the art, and do not define the limiting conditions for the implementation of the present application, and thus do not have substantial technical significance. Any modification of the structure, change of the ratio relationship or adjustment of the size, without affecting the effects and purposes that can be achieved by the present application, should still fall within the scope of the technical content disclosed by the present application. Meanwhile, the terms such as "upper", "lower", "left", "right", "middle" and "one" in the present specification are only for the convenience of clear description, and do not define the range of implementation of the present application. The change or adjustment of the relative relationship, without substantially changing the technical content, is also considered as the implementation scope of the present application.

[0032] As shown in Figures 1-7 The present application provides a motorcycle engine camshaft structure and an engine.

[0033] In an exemplary embodiment, the motorcycle engine camshaft structure comprises:

[0034] A camshaft 1, the camshaft 1 is provided with an exhaust cam 2;

[0035] A flange plate 5 is arranged on the camshaft 1, and a flyweight 15 is hingedly connected to the side of the flange plate 5 away from the exhaust cam 2. A valve core shaft 17 is rotatably connected to the camshaft 1, and the flyweight 15 can drive the valve core shaft 17 to rotate. The flange plate 5 is provided with a limiting assembly for limiting the valve core shaft 17.

[0036] In the present embodiment, the flyweight 15 can be thrown away when the engine starts, and simultaneously drive the valve core shaft 17 to rotate. After rotating by a certain angle, the valve core shaft 17 drives the valve to open in advance, reduces the pressure in the combustion chamber, and facilitates the starting of the engine.

[0037] Meanwhile, in the present embodiment, the valve core shaft 17 can reduce the pressure in the engine combustion chamber, and for a single-cylinder engine, it can have a larger displacement, which is beneficial to improve the performance of the engine.

[0038] It is worth mentioning that in the embodiment, the limit component is arranged to limit the valve core shaft 17, so as to avoid displacement deviation of the valve core shaft 17 during movement, to ensure that the valve core shaft 17 does not affect the valve during engine operation, to avoid the valve engine from opening the valve in advance under normal operation, and to ensure the normal operation of the engine, and the combustion efficiency of the engine is improved.

[0039] It is also worth mentioning that in the embodiment, the valve core shaft 17 is in the working position when in the low-speed state, and the flapper 15 is thrown out under the action of the centrifugal force when in the high-speed state, and the function of opening in advance disappears.

[0040] In an exemplary embodiment, the limit component includes a limit block and a limit bearing 10, the limit block is arranged on the flange plate 5, the limit block is provided with a clamping groove 9, the camshaft 1 is provided with a limit groove 3 along the axial direction of the camshaft 1, the clamping groove 9 and the limit groove 3 form an annular space, the limit bearing 10 is arranged in the annular space, and the valve core shaft 17 penetrates through the limit bearing 10.

[0041] In the embodiment, the limit bearing 10 is arranged to limit the axial and radial directions of the valve core shaft 17. Since the valve core shaft 17 needs to rotate to realize the corresponding function, and due to assembly, long-term wear and other reasons, a certain movement space is arranged corresponding to each movement direction of the valve core shaft 17. The valve core shaft 17 is prone to over-rotation or rotation out of position during operation, which may cause the valve to open in advance during normal operation of the engine. The limit bearing 10 is arranged to limit the axial and radial directions of the valve core, thereby ensuring the stability of the valve core shaft 17.

[0042] For example, the limit block includes a first limit part 6 and a second limit part 7 arranged continuously on the flange plate 5, a transition part 8 is arranged between the first limit part 6 and the second limit part 7, and the clamping groove 9 is arranged on the transition part 8. The first limit part 6 and the second limit part 7 are arranged in the form of embracing the camshaft 1, which enhances the fixing effect of the flange plate 5 and the camshaft 1, and the transition part 8 provides a mounting environment for the limit bearing 10.

[0043] It is worth mentioning that in the embodiment, the first limit part 6 and the second limit part 7 are arranged continuously on the flange plate 5 through the transition part 8, which is more convenient to install, and the transition part 8 can provide a mounting environment for the limit bearing 10, which is also more convenient for assembly of various parts.

[0044] In an exemplary embodiment, the camshaft 1 is provided with a mounting groove 4 for mounting the valve core shaft 17, the mounting groove 4 extends along the axial direction of the camshaft 1, the limit groove 3 and the mounting groove 4 are arranged continuously, at least a part of the mounting groove 4 extends into the exhaust cam 2, and the diameter of the limit groove 3 is greater than the diameter of the mounting groove 4.

[0045] In the embodiment, the installation groove 4 and the limiting groove 3 are arranged continuously along the axial direction of the camshaft 1 in a stepped groove, wherein the limiting groove 3 is located at the end of the camshaft 1 and extends to the middle of the camshaft 1, the installation groove 4 extends from the end of the limiting groove 3 close to the exhaust cam 2 to the exhaust cam 2 until a part of the installation groove 4 enters the body of the exhaust cam 2. The step formed between the limiting groove 3 and the installation groove 4 has two functions, the first is to install the bearing, the inner end surface of the bearing abuts against the step, which facilitates the positioning of the bearing, and the second is to install the camshaft 1, when the camshaft 1 passes through the flange plate 5, the limiting groove 3 can avoid the limiting bearing 10, so that the camshaft 1 can pass through the flange plate 5 smoothly and be fixed with the flange plate 5.

[0046] For example, in the embodiment, the end of the valve core shaft 17 is provided with a flat surface 18, and the flat surface 18 is located on the exhaust cam 2, that is, the part of the installation groove 4 mentioned above extends to the exhaust cam 2, when the flat surface 18 of the valve core is arranged outward, the flat surface 18 is lower than the base circle of the exhaust cam 2, at this time, the exhaust valve is in a closed state; when the flat surface 18 of the valve core becomes inclined or perpendicular to the axis of the camshaft 1, the flat surface 18 will be higher than the base circle of the exhaust cam 2, at this time, when the exhaust cam 2 rotates, the exhaust valve can be opened in advance by the flat surface 18 being higher than the base circle of the exhaust cam 2.

[0047] In an exemplary embodiment, the first limiting portion 6 is provided with a first boss 11, the second limiting portion 7 is provided with a second boss 12, the first boss 11 and the second boss 12 form a limiting space, the free end of the flail 15 can rotate around the rotation center of the flail 15 in the limiting space, the flail 15 is provided with a fixing groove 16, and the first boss 11 penetrates through the fixing groove 16.

[0048] For example, the valve core shaft 17 is provided with a lever 19, the lever 19 penetrates through the transition portion 8 and enters the fixing groove 16, and the lever 19 can swing in the overlapping area of the fixing groove 16 and the limiting space under the driving of the flail 15.

[0049] In the embodiment, the limiting space is provided to limit the free end of the flail 15 to swing between the area where the limiting space and the fixing groove 16 overlap, so as to limit the flail 15, and thus limit the rotation angle of the lever 19 and the rotation angle of the valve core shaft 17.

[0050] Exemplarily, the first boss 11 is provided with a first abutting part 1201, the second boss 12 is provided with a second abutting part 601, and the transition part 8 is provided with a third abutting part 801, and the first abutting part 1201, the second abutting part 601 and the third abutting part 801 are used for limiting the throw-out block 15. In the embodiment, in addition to the first boss 11 capable of limiting the throw-out block 15, the first abutting part 1201, the second abutting part 601 and the third abutting part 801 are all capable of limiting the throw-out block 15, so that the inaccuracy of limiting after the first boss 11 is worn out for a long time is avoided, and the limiting effect is improved.

[0051] It is worth noting that in the embodiment, the shift lever 19 passes through the fixing groove 16, so that the moving direction of the shift lever 19 in the axial direction of the camshaft 1 is limited, thereby limiting the movement of the valve core shaft 17 and improving the limiting effect.

[0052] In an exemplary embodiment, the second limiting part 7 is provided with a mounting part 14, and the camshaft 1 is provided with a pin shaft 20 penetrating into the mounting part 14.

[0053] In the embodiment, the pin shaft 20 is arranged, so that the relative rotation between the limiting block and the camshaft 1 is avoided, and the function of the valve core shaft 17 is affected.

[0054] In an exemplary embodiment, the flange plate 5 is further provided with a return spring 13, the return spring 13 is a tension spring, one end of the return spring 13 is arranged on the flange plate 5, and the other end of the return spring 13 is arranged on the throw-out block 15. When the engine normally works, the centrifugal force is greater than the elastic force of the return spring 13, the shift lever 19 abuts against the first boss 11, and the plane 18 faces the opening. At this time, the valve core shaft 17 does not need to open the valve in advance, and when the engine stops, the return spring 13 drives the throw-out block 15 to reset, the plane 18 is higher than the base circle of the exhaust cam 2, and the valve core shaft 17 can open the valve in advance.

[0055] In an exemplary embodiment, the end of the valve core shaft 17 is further provided with a limiting pin 1701. In addition to the first boss 11, the limiting pin 1701 can abut against the transition part 8 after the valve core shaft 17 rotates to a certain angle, so that the rotating angle of the valve core shaft 17 is limited, and the limiting effect is improved.

[0056] The utility model also proposes an engine, it includes above-mentioned engine camshaft 1 structure.

[0057] In conclusion, the limiting assembly is arranged, so that the valve core shaft 17 can be limited, thereby the displacement deviation of the valve core shaft 17 in the movement process can be avoided, the valve core shaft 17 is prevented from rotating excessively or not rotating in place in the normal operation process of the engine, the valve engine is prevented from opening the valve in advance in the normal operation state, the normal operation of the engine is ensured, and the combustion efficiency of the engine is guaranteed.

[0058] The above embodiments only exemplarily illustrate the principles and effects of the present application, and are not used to limit the present application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes completed by those skilled in the art without departing from the spirit and technical thought disclosed by the present application should be covered by the claims of the present application.

Claims

1. A motorcycle engine camshaft structure characterized by, The application relates to an engine camshaft structure. The engine camshaft structure comprises a camshaft, an exhaust cam provided on the camshaft, a flange plate provided on the camshaft, a weight hinged on the side of the flange plate away from the exhaust cam, a valve core shaft rotationally connected to the camshaft, the weight being capable of driving the valve core shaft to rotate, a limiting assembly provided on the flange plate and used for limiting the valve core shaft. The limiting assembly comprises a limiting block and a limiting bearing, the limiting block is provided on the flange plate, a clamping groove is provided on the limiting block, a limiting groove is provided on the camshaft along the axial direction of the camshaft, the clamping groove and the limiting groove form an annular space, the limiting bearing is arranged in the annular space, and the valve core shaft penetrates through the limiting bearing. An installation groove for installing the valve core shaft is arranged on the camshaft, the installation groove is arranged along the axial direction of the camshaft, the limiting groove and the installation groove are continuously arranged, at least a part of the installation groove extends into the exhaust cam, and the diameter of the limiting groove is larger than the diameter of the installation groove. The limiting block comprises a first limiting part and a second limiting part which are continuously arranged on the flange plate, a transition part is arranged between the first limiting part and the second limiting part, and the clamping groove is arranged on the transition part.

2. The motorcycle engine camshaft structure according to claim 1, characterized in that: A first boss is arranged on the first limiting part, a second boss is arranged on the second limiting part, the first boss and the second boss form a limiting space, the free end of the weight can rotate around the rotation center of the weight in the limiting space, a fixing groove is arranged on the weight, and the first boss penetrates through the fixing groove.

3. The motorcycle engine camshaft structure according to claim 2, characterized in that: A lever is arranged on the valve core shaft, the lever penetrates through the transition part and enters the fixing groove, and the lever can swing in the overlapping area of the fixing groove and the limiting space under the driving of the weight.

4. The motorcycle engine camshaft structure according to claim 3, characterized in that: A first abutting part is arranged on the first boss, a second abutting part is arranged on the second boss, a third abutting part is arranged on the transition part, and the first abutting part, the second abutting part and the third abutting part are used for limiting the weight.

5. The motorcycle engine camshaft structure according to claim 3, characterized in that: An installation part is arranged on the second limiting part, and a pin shaft penetrating through the installation part is arranged on the camshaft.

6. The motorcycle engine camshaft structure according to claim 2, characterized in that: A reset spring is further arranged on the flange plate and used for resetting the weight.

7. The motorcycle engine camshaft structure according to claim 1, characterized in that: The application further discloses an engine camshaft structure comprising any one of the engine camshaft structures as claimed in claims 1-7.

8. An engine characterized by: ​

Images