TWI816430B - Limiting structure of internal combustion engine pressure reducing device - Google Patents

Abstract

The present invention relates to a limiting structure of a decompression device of an internal combustion engine. The decompression device is assembled on a camshaft. The camshaft has at least an exhaust cam and a timing sprocket that drives the camshaft to rotate; the decompression device The device includes a support seat arranged along the axial direction of the camshaft, a swing arm pivoted on the support seat, a reset unit provided on the camshaft and capable of interacting with the swing arm, and a reducer that can be driven by the swing arm. When pressing the camshaft group, the outer surface of the support seat is provided with a limiting portion. The limiting portion at least includes a first diameter portion that is a first length away from the central axis of the camshaft, and a second length away from the central axis of the camshaft. A second diameter portion, a first stopper portion is formed between the first diameter portion and the second diameter portion; a limiting bump is protruded toward the support seat on one side of the swing arm, and is formed by the diameter of the camshaft. Viewed from the direction, the limiting protrusion is located outside the outer contour of the first stop part and overlaps and contacts it in projection; whereby the limiting part can be formed integrally with the support seat, so that it can The processing engineering required for setting up the limiting part is reduced, the versatility of the limiting part is improved, and the difficulty of designing the limiting structure of the pressure reducing device is reduced, thereby improving the efficiency of the pressure reducing device.

Description

Limiting structure of internal combustion engine pressure reducing device

The present invention relates to a limiting structure of a pressure reducing device of an internal combustion engine, and in particular, to a limiting structure of a pressure reducing device of an internal combustion engine that ensures the swing limiting effect of a swing arm.

Press, the swing arm of the internal combustion engine decompression device is rotated by the centrifugal force generated by the rotation of the camshaft. In order to avoid the excessive swing angle of the swing arm from interfering with other components, and the positioning effect of the swing arm when the camshaft does not rotate, the swing arm returns to its original position. , so the swing angle of the swing arm must be limited.

As shown in Figures 1 and 2, the applicant applied for the domestic patent I575151 "Pressure Reducing Device for Internal Combustion Engines", which provides a limiter hole 111 on the base 11 of the pressure reducing device 1, and at the same time, A limiter block 121 is protruding from one end of the swing arm 12. The limiter block 121 is embedded in the limiter hole 111, and the limiter hole 111 limits the range of movement of the limiter block 121, thereby limiting the movement of the limiter block 121. The swing angle of the swing arm 12; however, the base 11 must have a certain degree of rigidity, so processing the stopper hole 111 on the base 11 will increase the difficulty of processing, and the stopper hole 111 also needs to have a certain degree of accuracy, which increases the overall manufacturing cost and manufacturing engineering difficulty of the pressure reducing device 1 .

Therefore, how to provide a limiting structure for a pressure reducing device of an internal combustion engine to simplify the manufacturing process of the swing arm limiting structure of the pressure reducing device and reduce the manufacturing cost has become an urgent issue for the internal combustion engine industry to solve.

The main purpose of the present invention is to provide a limiting structure of a pressure reducing device for an internal combustion engine, thereby overcoming the shortcomings of conventional limiting mechanisms of internal combustion engine pressure reducing devices such as difficulty in processing and difficulty in design.

To this end, some embodiments of the present invention provide a limiting structure of a pressure reducing device of an internal combustion engine. The pressure reducing device is assembled on a camshaft. The camshaft at least has an exhaust cam and a positive cam that drives the camshaft to rotate. When the sprocket; the decompression device includes a support seat provided along the axial direction of the camshaft, a swing arm pivoted on the support seat, a reset unit provided on the camshaft and capable of interacting with the swing arm, For the decompression camshaft group driven by the swing arm, the outer surface of the support seat is provided with a limiting portion. The limiting portion at least includes a first diameter portion that is a first length away from the central axis of the camshaft, and a distance away from the camshaft. The second diameter portion of the central axis of the shaft has a second length, and a first stop portion is formed between the first diameter portion and the second diameter portion; a limiting bump is provided on one side of the swing arm toward the support seat. , viewed from the radial direction of the camshaft, the limiting bump is located outside the outer contour of the first stop portion and overlaps and contacts it in projection.

To this end, some embodiments of the present invention provide a limiting structure of a decompression device for an internal combustion engine. The exhaust cam of the camshaft is provided with a bearing on one side adjacent to the timing sprocket, and the swing arm is located on the between the exhaust cam and the support seat, and the support seat is used to prevent the bearing from sliding toward the exhaust cam side.

To this end, some embodiments of the present invention provide a limiting structure of a decompression device for an internal combustion engine. The exhaust cam of the camshaft is provided with a bearing on one side adjacent to the timing sprocket. The support base is located on the Between the exhaust cam and the bearing, the swing arm is located between the bearing and the support seat between.

To this end, some embodiments of the present invention provide a limiting structure of a decompression device for an internal combustion engine. Viewed in the axial direction of the camshaft, a part of the outer edge of the first diameter portion of the support seat faces the second diameter portion. A second stopper that can accommodate at least the limiting protrusion is extended.

To this end, some embodiments of the present invention provide a limiting structure of a pressure reducing device for an internal combustion engine. A first stopper is formed between the first diameter portion and the second diameter portion; the first stopper has a The first stop surface has a flat surface, the second stop portion has a second stop surface, the second stop surface has a flat surface; the flat surface of the first stop surface and the second stop surface have a flat surface. This plane of the stop surface is arranged at an angle.

To this end, some embodiments of the present invention provide a limiting structure of a pressure reducing device for an internal combustion engine. The aforementioned support seat is provided with at least one stop surface for the limiting protrusion to contact and limit. The at least one The stop surface is formed on the forward side of the camshaft rotation direction.

To this end, some embodiments of the present invention provide a limiting structure of a decompression device for an internal combustion engine. The camshaft has at least an intake cam and an exhaust cam; at least one of the aforementioned stop surfaces on the support base is located on the support seat. Within the optimal angle range between the lobe portion of the intake cam and the lobe portion of the exhaust cam.

To this end, some embodiments of the present invention provide a limiting structure of a decompression device for an internal combustion engine. Viewed from the axial direction of the camshaft, the limiting convex block is located on the first diameter of the support seat. The outer edge of the part.

To this end, some embodiments of the present invention provide a limiting structure of an internal combustion engine pressure reducing device. The support base has a first support base and a second support base. The first support base is located between the second support base and the second support base. Between the exhaust cam, the swing arm is disposed between the first support seat and the second between the support seats; the limiting portion is provided on at least one of the first support seat and the second support seat.

To this end, some embodiments of the present invention provide a limiting structure of an internal combustion engine decompression device. The exhaust cam has a convex portion and a base circular portion; when viewed in the axial direction of the camshaft, the limiting portion is located at Within the range of the base circle portion of the exhaust cam.

The effect that the present invention can achieve through some embodiments is that the limiting part can be formed integrally with the support base, thereby reducing the processing engineering and lifting of the limiting part. Its versatility can reduce the difficulty in designing the limiting structure of the pressure reducing device, thereby improving the effectiveness of the pressure reducing device.

The effect that the present invention can achieve through some embodiments is to improve the compactness of the pressure reducing device.

The effect that the present invention can achieve through some embodiments is that it can improve the compactness of the pressure reducing device and ensure the limiting effect when the swing arm is reset after swinging.

The effect that the present invention can achieve through some embodiments is to ensure the limiting effect when the swing arm is reset after swinging.

The effect that the present invention can achieve through some embodiments is to improve the limiting effect of the swing arm when it is reset after swinging.

The effect that the present invention can achieve through some embodiments is to ensure the limitability of the swing arm when swinging and returning after swinging.

The effect that the present invention can achieve through some embodiments is to improve the limiting effect of the swing arm when it is reset after swinging.

The effect that the present invention can achieve through some embodiments is that it can improve the compactness of the pressure reducing device and facilitate the installation of the limiting part.

1: Pressure reducing device

11: base

111: Limiting hole

12: Swing arm

121:Limit block

2: Pressure reducing device

21:First support base

211:First shaft hole

212: First penetration hole

22:Second support base

221:Second shaft hole

222: Second penetration hole

223: Limiting part

2231:First diameter part

2232:Second diameter part

2233: First stopper

22331: First stop surface

2234: Second stopper

22341: Second stop surface

23: Swing arm

231:Pivot hole

232: Top support part

233:Action Department

2331:Notch slot

234:Limiting bump

24:Reset unit

241: Push piece

2411: Pushing part

2412:Rod

242: Elastic parts

25: Decompression camshaft group

251: Decompression camshaft

2511:Central Ministry

2512: Cam part

2513: Insertion hole

2514: Arc surface

2515:Flat section

252:Actuating pin

26:Pivot

3: Camshaft

31:Exhaust cam

311: Groove

31a: convex part

31b: base circle part

32:Intake cam

32a: convex part

32b: base circle part

33:First bearing

331: Outer ring part

332:Inner ring part

333: Ball part

34:Second bearing

35: Accommodation groove

36:Exhaust rocker arm

37: Timing sprocket

3a:Central axis

4: Two-wheeler

41: Frame unit

42: Steering mechanism

43:Ride unit

A:Internal combustion engine

A1: Cylinder department

A2: Piston assembly

A3:Crankshaft

A4: Continuous transmission system

A41: Speed change belt

A42:Output shaft

A5: Transmission unit

A51: Drive shaft

A52: transmission belt

A6: Electrical parts

A7: Liquid cooling radiator set

A71: Radiator water tank

A72: Cooling fan

A8: Swingarm

A9:Exhaust device

RW: rear wheel

T: driving parts

[Figure 1, 2] I575151 patent case.

[Fig. 3] is a schematic diagram of the pressure reducing device of the internal combustion engine of the present invention.

[Fig. 4] is an exploded view of the pressure reducing device of the present invention.

[Figure 5] is a schematic diagram of the assembly of the pressure reducing device of the present invention.

[Figure 6] is a schematic diagram of the limit of the pressure reducing device of the present invention.

[Fig. 7] is a cross-sectional view of the pressure reducing device of the present invention.

[Figures 8 and 9] are diagrams of the swing arm limiting action of the pressure reducing device of the present invention.

[Figs. 10 and 11] show an embodiment of the internal combustion engine of the present invention.

In order to make it easier for the examiner to understand the structure of the present invention and the effects it can achieve, it is described below with reference to the drawings;

First, please refer to the limiting structure of the internal combustion engine pressure reducing device of the present invention as shown in Figures 3, 4 and 5. The pressure reducing device 2 is assembled on the camshaft 3 and is adjacent to the exhaust gas of the camshaft 3. Cam 31. The pressure reducing device 2 at least includes a first support seat 21 or a second support seat 22 provided on the camshaft 3, and a swing arm 23 pivoted on the first support seat 21 or the second support seat 22. One or both of them are pivoted on the first support base 21 or the second support base 22 , the reset unit 24 is provided on the camshaft 3 and can resist the swing arm 23 , and can be driven by the swing arm 23 Pressure reducing camshaft group 25.

As shown in Figures 3, 4, 5, 6 and 7, the camshaft 3 has an exhaust cam 31 and an intake cam 32; the exhaust cam 31 has a lobe 31a and a base that can push the exhaust rocker arm 36. Round portion 31b; the intake cam 32 has a convex portion 32a and a base round portion 32b that can push the intake rocker arm; the camshaft 3 supports a first bearing 33 and a second bearing 34 respectively on both ends; A timing sprocket 37 is provided on one side of the camshaft 3. The timing sprocket 37 is connected to the crankshaft A3 of the internal combustion engine A through a driving member T, whereby the timing sprocket 37 can drive the camshaft 3 to rotate; The first bearing 33 is located between the exhaust cam 31 and the timing sprocket 37 .

As shown in Figures 3, 4, 5, 6 and 7, the present invention is implemented by setting up two support seats, that is, the support seat has a first support seat 21 and a second support seat 22; the first support seat 21 is along the The camshaft 3 is integrally formed on the camshaft 3 in the axial direction, or is tightly fitted on the camshaft 3 in the axial direction as another component. The first support seat 21 is adjacent to the exhaust cam. 31. Since the first support seat 21 is close to the exhaust cam 31, the first support seat 21 can also be formed by the side wall of the exhaust cam 31 extending along the axial direction of the camshaft 3; the present invention The first support seat 21 is illustrated as extending axially from the camshaft 3, but this does not limit the specific implementation of the first support seat 21 of the present invention; the first support seat 21 is installed away from the camshaft 3. The intake cam 32 is located on the side of the exhaust cam 31, that is, the camshaft 3 has an intake cam 32, an exhaust cam 31 and the first support seat 21 in sequence. The first support seat 21 is provided with a The first shaft hole 211; the first support base 21 is provided with a first through hole 212 on the other side of the first shaft hole 211; the exhaust cam 31 corresponds to the first hole 212 of the first support base 21. The penetration hole 212 has an opening-shaped inlay groove 311 recessed on its side.

As shown in Figures 3, 4, 5, 6 and 7, the second support seat 22 is located between the exhaust cam 31 and the first bearing 33; more specifically, the second support seat 22 is located along the The camshaft 3 is axially formed on the camshaft 3 in an integrally formed manner, or is tightly fitted on the camshaft 3 in the form of another component. The second support seat 22 of the present invention is formed by a diameter of the camshaft 3 The extension is given as an example, but does not limit the invention to the specific implementation of the second support seat 22; the second support seat 22 is provided on the camshaft 3 in a spaced manner from the first support seat 21; More specifically, the second support seat 22 is installed away from the exhaust cam 31 and on the side of the first support seat 21 , that is, the camshaft 3 is sequentially connected to the intake cam 32 , the intake cam 32 , and the intake cam 32 along the axial direction. The exhaust cam 31, the first support base 21 and the second support base 22; the second support base 22 is provided with a second shaft hole 221, and the second shaft hole 221 of the second support base 22 is in contact with the first support base. The first shaft hole 211 of the base 21 is provided correspondingly, and the second support base 22 is also provided with a second through hole 222 corresponding to the first through hole 212 of the first support base 21. The second support base 22 A limiting portion 223 is provided on the side of the second shaft hole 221 and the second through hole 222 . Viewed from the axial direction of the camshaft 3 , the limiting portion 223 is located on the exhaust cam 31 Within the range of the base circular portion 31b; the second support seat 22 on the camshaft 3 is provided with a first bearing 33 on the side away from the first support seat 21 for supporting the camshaft 3, that is, the first bearing 33 is provided. A bearing 33 is provided on the adjacent side of the second support seat 22. The first bearing 33 has an outer ring portion 331, an inner ring portion 332, and a ball portion located between the outer ring portion 331 and the inner ring portion 332. 333, the inner ring portion 332 of the first bearing 33 and the camshaft 3 are connected in a tight fitting manner, whereby the inner ring portion 332 of the first bearing 33 can be driven by the camshaft 3 to rotate synchronously. ; The camshaft 3 is also provided with a second bearing 34 on the side of the intake cam 32; it should be mentioned that when the present invention is implemented, the limiting portion 223 can also be provided on the first support seat 21; as follows The description is still based on the example of arranging the limiting part 223 on the second support base 22 .

As shown in Figures 4, 8, and 9, the arc-shaped arrows in Figures 8 and 9 represent the rotation direction of the camshaft 3; the limiting portion 223 of the second support seat 22 has a first distance from the central axis 3a of the camshaft 3. The length of the first diameter portion 2231 and the second length of the second diameter portion 2232 from the central axis 3a of the camshaft 3. In a specific embodiment of the present invention, the length of the first diameter portion 2231 from the central axis 3a of the camshaft 3 is Less than, the distance between the second diameter portion 2232 and the central axis 3a of the camshaft 3; a first stop portion 2233 can be formed between the first diameter portion 2231 and the second diameter portion 2232. It has a first stop surface 22331, which has a plane along the radial direction of the second support seat 22; a part of the outer edge of the first diameter portion 2231 extends toward the second diameter portion 2232. The second stop portion 2234 has a second stop surface 22341. The second stop surface 22341 has a plane along the arc direction of the outer peripheral edge of the second support base 22, whereby the second stop portion 2234 has a second stop surface 22341. The surface 22341 has an accommodation effect or a guiding effect at the same time. The plane of the first stop surface 22331 and the plane of the second stop surface 22341 are arranged at an angle. The first stop surface 22331 and the second stop surface 22341 are at least One is disposed toward the forward side in the rotation direction of the camshaft 3; at least one of the first stop surface 22331 and the second stop surface 22341 is disposed between the wheel convex portion 32a of the intake cam 32 and the between the convex portion 31a of the exhaust cam 31; furthermore, at least one of the first stop surface 22331 and the second stop surface 22341 is provided between the convex portion 32a of the intake cam 32 and the Within the optimal angular range between the lobe portions 31a of the exhaust cam 31, thereby ensuring the limiting effect of the limiting portion 223; because the limiting portion 223 is located outside the second support seat 22 profile, so the limiting part 223 can be formed integrally with the second support base 22, thereby reducing the processing engineering required for setting the limiting part 223; What needs to be mentioned more is that when the camshaft 3 of the internal combustion engine A has to be changed due to the change of the engine model, since the limiting portion 223 is provided on the outer profile of the second supporting seat 22, the limiting portion The portion 223 can still be applied, thereby improving the versatility of the limiting portion 223 and thereby reducing the difficulty in designing the limiting mechanism of the pressure reducing device 2 of the internal combustion engine A.

As shown in Figures 4, 6, 7, 8, and 9, the swing arm 23 is disposed between the exhaust cam 31 and the second support seat 22, or the swing arm 23 is disposed on the first bearing. 33 and the first support seat 21, the second support seat 22 can be used to prevent the first bearing 33 from sliding toward the exhaust cam 31 side. In the present invention, the swing arm 23 is arranged on the first support Take the example between the base 21 and the second support base 22; the swing arm 23 is an arc-shaped body, and a pivot hole 231 is provided at one end of the swing arm 23. The pivot hole 231 is connected to the first support base. The first axis hole 211 of 21 corresponds to the second axis hole 221 of the second support base 22, whereby a pivot 26 can be inserted through the second axis hole 221 of the second support base 22. The pivot hole 231 of the swing arm 23 and the first shaft hole 211 of the first support base 21 allow the swing arm 23 to swing freely with the pivot 26 as the swing center. The pivot 26 passes through When the second shaft hole 221 of the second support base 22 and the first shaft hole 211 of the first support base 21 are tightly connected with at least one of the second shaft hole 221 or the first shaft hole 211 The swing arm 23 and the pivot shaft 26 are connected in a sliding fit manner. The swing arm 23 is pivoted between the second axis hole 221 of the second support base 22 and the first shaft hole 221 of the second support base 22 through the pivot shaft 26 . The first axis hole 211 of the support base 21 can thereby support both ends of the pivot shaft 26. Therefore, the pivot shaft 26 can be prevented from being cantilevered for the swing arm 23 to pivot. Accordingly, the pivot shaft 26 can be pivoted. The shaft 26 can maintain proper rigidity; the pivot 26 is arranged parallel to the central axis 3a of the camshaft 3 .

As shown in Figures 4, 5, 6, 7, 8, and 9, the swing arm 23 is provided with a supporting portion 232 extending outward from one end of the pivot hole 231, and the swing arm 23 is provided with a supporting portion 232 at the other end of the pivot hole 231. There is an actuating part 233. The actuating part 233 has a notch groove 2331 opened laterally by the swing arm 23. The swing arm 23 is provided with a limiting protrusion 234 extending outwardly from the side between the supporting part 232 and the actuating part 233. , furthermore, when viewed from the axial direction of the camshaft 3 , the limiting protrusion 234 is located at the outer edge of the first diameter portion 2231 of the limiting portion 223 of the second support seat 22 . The block 234 is provided correspondingly to the limiting portion 223 of the second support base 22. The limiting protrusion 234 extends into the upper end edge of the limiting portion 223 of the second support base 22 and contacts the limiting portion 223. The upper end edge of the position portion 223 moves and is limited to a moving distance. Furthermore, when viewed in the radial direction of the camshaft 3, the limiting protrusion 234 and the limiting portion 223 are arranged to overlap and contact each other. This limits the swing position of the swing arm 23; since the limiting portion 223 is provided on the outer profile of the second support base 22, the limiting protrusion 234 secures the limiting portion 223 after installation. Above and in contact with each other in a projected overlapping manner, the contact area of the limiting bump 234 and the limiting part 223 can be reduced when the limiting action is performed, thereby preventing the limiting bump 234 from contacting the limiting part 223 A sticky situation occurs.

As shown in Figures 4, 5, and 7, the camshaft 3 is provided with a receiving groove 35 in the radial direction between the second support seat 22 and the first support seat 21, and the reset unit 24 is embedded In the receiving groove 35 of the camshaft 3, the reset unit 24 can be composed of a single elastic member, or a combination of an elastic member and a pushing member; in the present invention, the reset unit 24 is composed of an elastic member and a pushing member. A push piece is used as an example; the reset unit 24 has a push piece 241 and an elastic member 242 sleeved on the outer circumference of the push piece 241; the push piece 241 has The push part 2411 with a larger outer diameter and the rod part 2412 extending to one side from the push part 2411, the elastic member 242 is located below the push part 2411 and on the outer circumference of the rod part 2412. The pushing portion 2411 of the pushing member 241 abuts against the supporting portion 232 of the swing arm 23 .

As shown in Figures 4, 5, and 7, the pressure reducing camshaft group 25 has a pressure reducing camshaft 251 and an actuating pin 252 inserted on the pressure reducing camshaft 251. The pressure reducing camshaft 251 has a pivot portion 2511. With the cam portion 2512, the pivot portion 2511 can be pivoted through the first through hole 212 of the first support base 21 and the second through hole 222 of the second support base 22. The pivot portion 2511 is An insertion hole 2513 is provided in the radial direction, and the insertion hole 2513 can be used for inserting the actuating pin 252. The other end of the actuating pin 252 is embedded in the notch groove 2331 of the actuating part 233 of the swing arm 23. The swing arm 23 can drive the actuating pin 252 when swinging, so that the swing arm 23 can drive the decompression camshaft group 25 to rotate; the cam portion 2512 fastens the insert located on the exhaust cam 31 side. In the groove 311, one side of the cam portion 2512 is an arc surface 2514, and the other side is a flat surface 2515.

As shown in FIGS. 10 and 11 , the present invention takes the internal combustion engine A implemented in the two-wheeled vehicle 4 as an example, but the application scope of the internal combustion engine A is not limited thereto. The two-wheeled vehicle 4 at least has a frame unit 41. The front end of the frame unit 41 is provided with a steering mechanism 42. The rear section of the frame unit 41 is provided with a riding unit 43 for a driver to ride on. The internal combustion engine A is hung on the On the frame unit 41 and located below the riding unit 43; the internal combustion engine A has a cylinder part A1, a piston assembly A2 extending into the cylinder part A1, a crankshaft A3 that can be driven by the piston assembly A2, and a crankshaft A3 that can be driven by the crankshaft. The continuously variable transmission system A4 driven by A3 can be controlled by the continuously variable transmission system. The transmission unit A5 driven by A4; the crankshaft A3 is equipped with an electric component A6 and a liquid cooling radiator group A7 on the other side of the continuously variable transmission system A4; the continuously variable transmission system A4 has a transmission belt A41 and an output shaft A42; the transmission Unit A5 has a transmission shaft A51. The transmission shaft A51 is provided with a transmission belt A52 that can drive the rear wheel RW. The two ends of the transmission shaft A51 are pivoted with a freely swinging rear rocker A8. The transmission shaft A51 and the output shaft A42 is arranged coaxially; the liquid cooling radiator group A7 has a water tank A71 and a cooling fan A72; the internal combustion engine A is provided with an exhaust device A9 on the side of the continuously variable transmission system A4.

As shown in Figures 3, 5, 6, 7, 8 and 9, the pressure reducing device 2 of the present invention is implemented. The pressure reducing device 2 is assembled on the camshaft 3 in the axial direction of the camshaft 3, and is located between the exhaust cam 31 and the first bearing 33; when the internal combustion engine A is not started, the decompression device 2 can push the holding portion 232 of the swing arm 23 through the reset unit 24, so that The limiting protrusion 234 of the swing arm 23 is limited by the first stop portion 2233 of the limiting portion 223 of the second support base 22, whereby the actuating portion 233 of the swing arm 23 can be moved by the actuating pin. 252 to drive the decompression camshaft 251 to rotate at a preset angle, so that the arc surface 2514 of the cam portion 2512 can slightly protrude from the base circle of the exhaust cam 31, so that the exhaust rocker arm 36 can be formed Pushing up, the exhaust valve (not shown in the figure) can be slightly opened; when the internal combustion engine A is started, the swing arm 23 of the decompression device 2 will generate a force with the rotation of the camshaft 3 The centrifugal force will swing with the pivot 26 as the swing center. When the swing arm 23 swings, the swing arm 23 will use the actuating part 233 to drive the actuating pin 252 of the decompression camshaft group 25 , so that the pivot portion 2511 of the decompression camshaft 251 can rotate at a larger angle as the rotation center, and then the arc surface 2514 of the decompression camshaft group 25 can be screwed into the insert groove 311, and The pressure reducing camshaft 251 The flat surface 2515 of the cam portion 2512 rotates out toward the outside of the notch 311, whereby the arc surface 2514 of the cam portion 2512 of the decompression camshaft group 25 no longer protrudes from the exhaust cam 31 base circle, and the decompression camshaft 251 of the decompression camshaft group 25 no longer pushes the exhaust rocker arm 36; because the limiting bump 234 of the swing arm 23 enters the second support seat 22 The limiting part 223 is limited by the first stopping part 2233. Therefore, through the mutual limiting effect of the limiting protrusion 234 of the swing arm 23 and the limiting part 223 of the second support base 22, The rotation range of the decompression camshaft group 25 is limited.

The effect of the present invention is that, the decompression device 2 is assembled on the camshaft 3, and the camshaft 3 has at least an intake cam 32 and an exhaust cam 31; 3. The second support base 22 provided axially, the swing arm 23 pivoted on the second support base 22, and the reset unit 24 provided on the camshaft 3 and interacting with the swing arm 23 can be The decompression camshaft group 25 driven by the swing arm 23 has a limiting portion 223 on the outer surface of the second support seat 22. The limiting portion 223 at least includes a first diameter that is closer to the central axis 3a of the camshaft 3. part 2231, and a second diameter part 2232 far away from the central axis 3a of the camshaft 3. A first stop part 2233 is formed between the first diameter part 2231 and the second diameter part 2232; the swing arm 23 A limiting protrusion 234 protrudes toward the second support seat 22 on one side of the camshaft 3 . When viewed from the radial direction of the camshaft 3 , the limiting protrusion 234 is located above the first stop portion 2233 , overlaps in projection, and contacts. ; In this way, the limiting portion 223 can be formed integrally with the second support base 22, thereby reducing the processing engineering required for setting the limiting portion 223 and improving the versatility of the limiting portion 223, and can This reduces the difficulty in designing the limiting structure of the pressure reducing device 2, thereby improving the efficiency of the pressure reducing device 2.

To sum up, the structure of the present invention can indeed achieve the claimed purpose, and it should meet the requirements of novelty, advancement and practicality for an invention patent. I am filing an application for an invention patent in accordance with the law. I pray for your review and assistance. For the review and approval of the patent, it is up to Gan De.

2: Pressure reducing device

21:First support seat

211:First shaft hole

212: First penetration hole

22:Second support base

221:Second shaft hole

222: Second penetration hole

223: Limiting part

22331: First stop surface

22341: Second stop surface

23: Swing arm

231:Pivot hole

232: Top support part

233:Action Department

2331:Notch slot

234:Limiting bump

24:Reset unit

241: Push piece

2411: Pushing part

2412:Rod

242: Elastic parts

25: Decompression camshaft group

251: Decompression camshaft

2511:Central Ministry

2512: Cam part

2513: Insertion hole

2514: Arc surface

2515:Flat section

252:Actuating pin

26:Pivot

3: Camshaft

31:Exhaust cam

311: Groove

31a: convex part

31b: base circle part

32:Intake cam

32a: convex part

32b: base circle part

33:First bearing

331: Outer ring part

332:Inner ring part

333: Ball part

34:Second bearing

35: Accommodation groove

Claims (10)

A limiting structure of a decompression device of an internal combustion engine. The decompression device is assembled on a camshaft. The camshaft has at least an exhaust cam and a timing sprocket that drives the camshaft to rotate. The decompression device includes an exhaust cam along the camshaft. a support seat arranged axially upward, a swing arm pivoted on the support seat, a reset unit provided on the camshaft and capable of interacting with the swing arm, and a decompression camshaft group capable of being driven by the swing arm, It is characterized in that: the outer surface of the support seat is provided with a limiting portion, and the limiting portion at least includes a first diameter portion that is a first length away from the central axis of the camshaft, and a second length away from the central axis of the camshaft. The second diameter portion has a first stopper portion formed between the first diameter portion and the second diameter portion; a limiting convex portion is protruded toward the support seat on one side of the swing arm, and is formed by the radial direction of the camshaft. Viewed from a visual perspective, the limiting bump is located outside the outer contour of the first stop portion and overlaps and contacts it in projection. The limiting structure of the decompression device of an internal combustion engine as described in claim 1, wherein a bearing is provided on the side of the exhaust cam of the camshaft adjacent to the timing sprocket, and the swing arm is provided between the exhaust cam and the timing sprocket. between the support seats, and the support seat is used to prevent the bearing from sliding toward the exhaust cam side. The limiting structure of the internal combustion engine decompression device as claimed in claim 1, wherein a bearing is provided on the side of the exhaust cam of the camshaft adjacent to the timing sprocket, and the support base is provided between the exhaust cam and the timing sprocket. Between the bearings, the swing arm is disposed between the bearings and the support seat. The limiting structure of the internal combustion engine decompression device as claimed in claim 1, wherein, viewed from the axial direction of the camshaft, a portion of the outer edge of the first diameter portion of the support seat extends towards the second diameter portion with at least The second stop portion can be used to accommodate the limiting bump. The limiting structure of the internal combustion engine pressure reducing device as described in claim 4, wherein the third A first stop portion is formed between a diameter portion and the second diameter portion; the first stop portion has a first stop surface, the first stop surface has a flat surface, and the second stop portion has a second stop portion. The second stop surface has a flat surface; the flat surface of the first stop surface and the flat surface of the second stop surface are arranged at an angle. The limiting structure of the internal combustion engine pressure reducing device as claimed in claim 5, wherein the aforementioned support seat is provided with at least one stop surface for the limiting convex block to contact and limit, and the at least one stop surface forms On the forward side of the camshaft rotation direction. The limiting structure of the internal combustion engine decompression device as claimed in claim 5, wherein the camshaft has at least an intake cam and an exhaust cam; the at least one stop surface on the support seat is located on the intake cam Within the optimal angle range between the lobe portion and the lobe portion of the exhaust cam. The limiting structure of the internal combustion engine decompression device according to any one of claims 1 to 4, wherein, viewed from the axial direction of the camshaft, the limiting convex block is located on the first side of the supporting seat. The outer edge of the diameter. The limiting structure of the internal combustion engine pressure reducing device as claimed in claim 2 or 3, wherein the support base has a first support base and a second support base, and the first support base is located between the second support base and the exhaust gas Between the cams, the swing arm is provided between the first support base and the second support base; the limiting portion is provided on at least one of the first support base and the second support base. The limiting structure of the internal combustion engine decompression device as claimed in claim 1, wherein the exhaust cam has a convex portion and a base circular portion; when viewed in the axial direction of the camshaft, the limiting portion is located on the exhaust cam within the range of the base circle.

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