TW201529957A - Pressure relief device of internal combustion engine - Google Patents

Abstract

The present invention relates to a pressure relief device of an internal combustion engine. The pressure relief device is assembled on a camshaft. The camshaft comprises an intake cam and an exhaust cam. The end of camshaft at the exhaust cam is configured with a receiving groove. The side of exhaust cam at the receiving groove is configured with a pivoting hole. The pressure relief device comprises a base plate, a counterweight swing arm, an elastic element, a pressure relief camshaft and a shaft rod. The base plate is disposed on the camshaft adjacent to the exhaust cam, and is configured with a shaft hole. The opposite end of the shaft hole is configured with a position-limiting hole. The two ends between the shaft hole and the position-limiting hole are respectively configured with a through hole and an engaging groove. One end of the counterweight swing arm is configured with a pivot hole, and the pivot hole is corresponded to the shaft hole of the base plate. The side of the counterweight swing arm near the pivot hole is configured with a hook hole. The counterweight swing arm is configured with a notch. Another end of the counterweight swing arm at the pivot hole is configured with a position-limiting bump protruded outwardly. One end of the position-limiting bump may be slidably inserted within the position-limiting hole of the base plate. One end of the elastic element is hooked on the engaging groove of the base plate, and another end is hooked in the hook hole of the counterweight swing arm. The pressure relief camshaft is received within the receiving groove of the camshaft and is penetrated through the through hole of the base plate. The pressure relief camshaft comprises a base portion. A cam portion is extended from the base portion toward the direction of the exhaust cam. One side of the cam portion is an arc surface, and another side is a flat surface. The edge of the cam portion is extended with a pivot portion. One end of the pivot portion is inserted into the pivoting hole of the exhaust cam. The base portion of the pressure relief camshaft is extended with a lever portion on another side of the extended cam portion. One end of the lever portion may be slidably inserted in the notch of the counterweight swing arm. One end of the shaft rod is inserted in the shaft hole of the base plate, and another end is inserted in the pivot hole of the counterweight swing arm. Thus, when the counterweight swing arm is driven by the centrifugal force of camshaft rotation for swinging, the pressure relief camshaft may be driven to rotate within the receiving groove of the camshaft. While being used for the internal combustion engines of different exhaust volumes, it is only required to process and change the radial position of the receiving groove on the camshaft for directly applying the pressure relief device with no need of manufacturing a new pressure relief device, so as to enhance the universality of the pressure relief device and further enhance the effect of the pressure relief device.

Description

Pressure reducing device for internal combustion engine

The present invention relates to a pressure reducing device for an internal combustion engine, and more particularly to a pressure reducing device for an internal combustion engine which can improve the versatility of a pressure reducing device for an internal combustion engine.

As shown in Fig. 1, at the beginning of the internal combustion engine 1, in order to prevent the piston 11 provided in the internal combustion engine 1 from rising when the bottom dead center rises, the pressure reducing device 14 is disposed on the cam shaft 13 in the cylinder head 12.

The decompression device 14 is disposed beside the exhaust cam 131 of the camshaft 13 , and the exhaust rocker arm 15 is pushed by the decompression device 14 at the beginning of the internal combustion engine 1 . After being pushed up by the pressure reducing device 14, the exhaust valve (not shown) is opened to a slight opening, whereby when the internal combustion engine 1 is started, the piston 11 is bottom dead center. When the air pressure generated by the combustion chamber 16 is pushed up, the air pressure generated by the rising of the piston 11 can be discharged from the slightly opened exhaust valve, thereby reducing the impedance of the piston 11 when it is pushed up from the bottom dead center. The 俾 can facilitate the starting of the internal combustion engine 1.

The internal combustion engine 1 can reduce the impedance of the piston 11 when it is pushed up from the bottom dead center by providing a pressure reducing device 14 on one side of the cam shaft 13. However, how to ensure the operability of the decompression device 14 and how to make the decompression device 14 widely applicable to the internal combustion engine 1 of various exhaust amounts should be an urgent problem to be overcome by the internal combustion engine.

SUMMARY OF THE INVENTION A primary object of the present invention is to provide a pressure reducing device for an internal combustion engine, whereby the lack of versatility of the pressure reducing device of the conventional internal combustion engine can be overcome.

The present invention is directed to the above object, and the main technical means employed is to provide a pressure reducing device for an internal combustion engine, the pressure reducing device being assembled on a cam shaft having an intake cam and an exhaust cam, the cam shaft Having a receiving groove at the exhaust cam end, the exhaust cam is The accommodating recess side is provided with a pivot hole; the decompression device comprises a base plate, a counterweight swing arm, an elastic component, a decompression camshaft and a shaft; the base plate is disposed on the camshaft and adjacent to the camshaft An exhausting cam, the base plate is provided with a shaft hole, and a limiting hole is disposed at an opposite end of the shaft hole, and the two ends between the shaft hole and the limiting hole are respectively provided with a consistent perforation and a fitting groove; the weight swinging arm a pivot hole is disposed at one end, the pivot hole corresponding to the shaft hole of the base plate, and the weight swing arm is provided with a hook hole adjacent to the pivot hole, and the weight swing arm is provided with all slots, the weight The other end of the pivot arm is provided with an outwardly protruding limiting protrusion, and one end of the limiting protrusion is slidably inserted into the limiting hole of the base; the elastic element is hooked at one end The other end of the base plate is hooked on the hook hole of the weight swing arm; the decompression camshaft is received in the receiving groove of the cam shaft and passes through the through hole of the base plate. The decompression camshaft has a base portion, and a cam portion is extended from the base portion toward the exhaust cam. The cam portion has a circular arc surface on one side and the other side a pivoting portion, the end edge of the cam portion is extended with a pivot portion, one end of the pivot portion is inserted into the pivot hole of the exhaust cam, and the base of the decompression camshaft is extended to the cam portion a lever portion is disposed on one side, and one end of the lever portion is slidably inserted into the slot of the weight swing arm; one end of the shaft is inserted into the shaft hole of the base, the shaft The other end is inserted into the pivot hole of the counterweight swing arm.

The effect that the present invention can achieve by the above technical means is that when the weight swing arm is swung by the centrifugal force of the rotation of the cam shaft, the recessed cam shaft can be driven to receive the recessed groove of the cam shaft. Internal rotation; when it is intended to be used in an internal combustion engine with different displacements, it is only necessary to process and change the accommodating groove in the radial position of the camshaft to directly apply the pressure reducing device without making a new pressure reducing device. Thereby, the versatility of the pressure reducing device can be improved, thereby improving the use efficiency of the pressure reducing device.

1‧‧‧ internal combustion engine

11‧‧‧Piston

12‧‧‧ cylinder head

13‧‧‧Camshaft

131‧‧‧Exhaust cam

14‧‧‧Decompression device

15‧‧‧Exhaust rocker

16‧‧‧ combustion chamber

2‧‧‧Reducing device

21‧‧‧Base

211‧‧‧ shaft hole

212‧‧‧Limited holes

213‧‧‧through holes

214‧‧‧ slotted

21a‧‧‧ Missing slot

22‧‧‧weight swing arm

221‧‧‧Pivot hole

222‧‧‧ hook hole

223‧‧‧ slotting

224‧‧‧Extension

225‧‧‧ Limit bumps

23‧‧‧Flexible components

24‧‧‧Decompression camshaft

241‧‧‧ base

242‧‧‧Cam Department

2421‧‧‧Arc surface

2422‧‧ ‧ flat cut

243‧‧‧ pivot

244‧‧‧Dipstick

25‧‧‧ shaft

3‧‧‧Camshaft

31‧‧‧Exhaust cam

311‧‧‧ pivot hole

32‧‧‧Intake cam

33‧‧‧ accommodating grooves

A‧‧‧ internal combustion engine

Figure 1 is a schematic view of a pressure reducing device of a conventional internal combustion engine.

Figure 2 is a schematic view of a pressure reducing device of the internal combustion engine of the present invention.

Figure 3 is an exploded view of the pressure reducing device of the internal combustion engine of the present invention.

Figure 4 is a schematic view showing the assembly of the pressure reducing device of the present invention.

Figure 5 is a schematic view showing a reduced pressure state of the pressure reducing device of the internal combustion engine of the present invention.

FIG.

In order to make it easier for the examiner to understand the structure of the present invention and the achievable effects, the following description is provided with reference to the drawings; first, referring to the second and third embodiments, the pressure reducing device of the internal combustion engine of the present invention, the pressure reducing device The 2 series is disposed on the camshaft 3 and is adjacent to the exhaust cam 31 of the camshaft 3. The decompression device 2 includes a base 21, a counterweight arm 22, an elastic element 23, and a decompression cam. A shaft 24 and a shaft 25.

The base plate 21 is integrally formed on the cam shaft 3 or is fitted to the cam shaft 3 in another member manner, and the base plate 21 is adjacent to the exhaust cam 31; more specifically, the base plate 21 It is mounted on the side of the exhaust cam 31 away from the intake cam 32, that is, the cam shaft 3 is sequentially connected to the intake cam 32, the exhaust cam 31 and the base 21, and the base 21 is provided with a shaft hole 211. A long arc-shaped limiting hole 212 is disposed at an opposite end of the shaft hole 211, and a second end between the shaft hole 211 and the limiting hole 212 is respectively provided with a permanent through hole 213 and an opening facing outward. The groove 214; in addition, when the base plate 21 is tightly fitted to the cam shaft 3 by another member, the through hole 213 is recessed by the base plate 21 with a notch 21a and the cam shaft 3 concave. The accommodating recesses 33 are formed in common.

The weight swing arm 22 is an arc-shaped body. One end of the weight swing arm 22 is provided with a pivot hole 221 corresponding to the shaft hole 211 of the base plate 21, and the weight swing arm 22 A hook hole 222 is disposed adjacent to the pivot hole 221, and an opening opening 223 is formed in the hook hole 222 toward the other end of the weight swing arm 22 and facing the one side of the base plate 21, the slot The 223 is formed by a substantially parallel surface. The outer side of the slot 223 defines an extending portion 224. The end of the extending portion 224 has a limiting protrusion 225 protruding from a side thereof, that is, the weight swing arm 22 is pivoted. The other end of the shaft hole 221 is provided with a limiting protrusion 225 protruding outward.

One end of the elastic member 23 is hooked on the recess 214 of the base plate 21, and the other end of the elastic member 23 is hooked on the hook hole 222 of the weight swing arm 22.

The decompression camshaft 24 has a base portion 241. The decompression camshaft 24 has a cam portion 242 extending from the base portion 241 toward the exhaust cam 31. The cam portion 242 has a circular arc surface 2421 on one side and a flat surface on the other side. 2422, the end of the cam portion 242 The pivot portion 243 is provided with a pivot portion 243. The base portion 241 of the decompression camshaft 24 is extended with a lever portion 244 on the other side of the extended cam portion 242.

One end of the shaft 25 is inserted into the shaft hole 211 of the base 21, and the other end of the shaft 25 is inserted into the pivot hole 221 of the weight swing arm 22.

Referring to FIG. 2, FIG. 3 and FIG. 4, the decompression device 2 of the present invention is assembled. The cam shaft 3 is provided with an exhausting groove 31 on the side of the exhaust cam 31, and an open receiving recess 33 is formed. The camshaft 3 is far away. The end edge of the air cam 32 is provided with a pivot hole 311 at the venting cam 31; the base 21 of the pressure reducing device 2 is disposed on the cam shaft 3 adjacent to the exhaust cam 31, the pressure reducing device The decompression camshaft 24 of the second embodiment is inserted into the through hole 213, and the decompression camshaft 24 penetrates the pivot hole 311 of the camshaft 3 with the pivot portion 243, and then the one end of the shaft 25 is inserted. On the shaft hole 211 of the base plate 21, the weight swing arm 22 is finally inserted into the shaft 25 by the pivot hole 221, and the limiting protrusion 225 of the weight swing arm 22 is slidable. The shifting is inserted into the limiting hole 212 of the base 21, and one end of the elastic member 23 is hooked on the recess 214 of the base 21. The other end of the elastic member 23 is hooked to the counterweight arm 22 On the hook hole 222, at the same time, the lever portion 244 of the decompression camshaft 24 is slidably embedded in the slot 223 of the weight swing arm 22; thereby the weight swing arm 22 can be the shaft 2 5 is a swing of the swing center, and the decompression camshaft 24 is centered on the pivot portion 243 in the receiving recess 33, and is driven by the counterweight swing arm 22 to make a return of nearly 90 degrees, and The circular arc surface 2421 of the cam portion 242 of the decompression camshaft 24 protrudes from the accommodating recess 33 of the cam shaft 3 and slightly protrudes from the base circle of the exhaust cam 31, thereby completing the pressure reducing device of the present invention. The formation of 2.

As shown in FIGS. 2 and 5, when the internal combustion engine A is not actuated, the circular arc surface 2421 of the cam portion 242 of the decompression camshaft 24 of the decompression device 2 is slightly convex. The base circle of the exhaust cam 31 can thus form a topping of the exhaust rocker arm (not shown in the drawing), thereby allowing the exhaust valve to be slightly opened; as shown in Figures 2, 3 and 6, when After the internal combustion engine A is started, the centrifugal force generated by the counterweight swing arm 22 of the decompression device 2 with the rotation of the camshaft 3 will swing with the shaft 25 as the swing center, when the counterweight swing arm When the swinging arm 22 is rotated, the weight swing arm 22 will move the lever portion 244 of the pressure reducing camshaft 24 with the slit 223 to rotate the pressure reducing camshaft 24 with the pivot portion 243. The center rotates in the accommodating recess 33 of the camshaft 3, that is, the arcuate surface 2421 of the cam portion 242 of the decompression camshaft 24 is screwed into the accommodating recess 33, and the decompression camshaft The flat surface 2422 of the cam portion 242 of the second portion 24 is rotated out of the accommodating recess 33, whereby the cam portion 242 of the decompression camshaft 24 no longer protrudes from the base circle of the exhaust cam 31, and the decompression cam The shaft 24 no longer pushes the exhaust rocker arm; since the limiting protrusion 225 of the weight swing arm 22 is inserted into the limiting hole 212 of the base 21, the limit protrusion of the counterweight arm 22 is The interaction of the 225 with the limiting aperture 212 of the base 21 limits the extent of rotation of the reduced pressure camshaft 24.

The effect of the present invention is that a pivot hole 221 is defined at one end of the weight swing arm 22, and the pivot hole 221 corresponds to the shaft hole 211 of the base plate 21, and the weight swing arm 22 is adjacent to the pivot shaft. A hole 222 is defined in the hole 221, and an opening 223 is formed in the other end of the weight swinging arm 22, and the counterweight swinging arm 22 is disposed at the other end of the pivot hole 221 There is a limiting protrusion 225 protruding outwardly, the limiting protrusion 225 is inserted into the limiting hole 212 of the base 21; the decompression camshaft 24 has a base 241, and the decompression camshaft 24 is provided by the base A cam portion 242 having a smaller diameter than the base portion 241 is disposed in the direction of the exhaust cam 31. The cam portion 242 has a circular arc surface 2421 on one side and a flat cut surface 2422 on the other side. The end edge of the cam portion 242 extends a pivot. a shaft portion 243, the base portion 241 of the decompression camshaft 24 is extended with a lever portion 244 on the other side of the extended cam portion 242, and the lever portion 244 can be inserted into the slot 223 of the weight swing arm 22; When the counterweight swing arm 22 is swung by the centrifugal force of the rotation of the cam shaft 3, the decompression camshaft 24 can be rotated in the receiving recess 33 of the camshaft 3; When the internal combustion engine A (that is, the camshaft 3 of different outer diameters) is to be used for different displacements, the machining recess can be directly changed to the radial position of the camshaft 3, and the reduction can be directly applied. The device 2 is pressed without the need to make a new pressure reducing device 2, whereby the versatility of the pressure reducing device 2 can be improved, thereby improving the use efficiency of the pressure reducing device 2.

Another effect of the present invention is that the cam portion 242, the pivot portion 243, and the lever portion 244 of the decompression camshaft 24 are axially disposed, so that the radial volume of the decompression device 2 can be effectively reduced.

Yet another effect of the present invention is that the limit bump 2 of the swing arm 22 is supported by the counterweight The 25 series is inserted into the limiting hole 212 of the base 21 to define the maximum swing of the weight swing arm 22, so the limiting protrusion 225 of the weight swing arm 22 and the limiting hole of the base 21 The interaction of 212 can limit the amplitude of the rotation of the decompression camshaft 24, whereby the overall weight of the base 21 can be alleviated on the one hand; on the other hand, the lever portion 244 of the decompression camshaft 24 can be prevented from breaking.

A further effect of the present invention is that the weight swing arm 22 is an arcuate body, and the weight swing arm 22 extends outside the slot 223 with an extension 224, and the end of the extension 224 faces one side. A limiting protrusion 225 is convexly disposed, thereby increasing the inertia and operability of the weight swing arm 22.

The second effect of the present invention resides in that the slit 223 is formed by approximately two parallel faces, whereby the processing of the slit 223 can be facilitated.

The decompression device of the internal combustion engine of the present invention can achieve the purpose of appealing by the above-mentioned structure, and should meet the requirements of novelty, advancement and industrial utilization of the invention patent, and apply for an invention patent according to law, pray for it. Examine the detailed examination of the members and grant approval for the examination and approval of the invention patents.

2‧‧‧Reducing device

21‧‧‧Base

211‧‧‧ shaft hole

212‧‧‧Limited holes

213‧‧‧through holes

214‧‧‧ slotted

21a‧‧‧ Missing slot

22‧‧‧weight swing arm

221‧‧‧Pivot hole

222‧‧‧ hook hole

223‧‧‧ slotting

224‧‧‧Extension

225‧‧‧ Limit bumps

23‧‧‧Flexible components

24‧‧‧Decompression camshaft

241‧‧‧ base

242‧‧‧Cam Department

2421‧‧‧Arc surface

2422‧‧ ‧ flat cut

243‧‧‧ pivot

244‧‧‧Dipstick

25‧‧‧ shaft

3‧‧‧Camshaft

31‧‧‧Exhaust cam

311‧‧‧ pivot hole

32‧‧‧Intake cam

33‧‧‧ accommodating grooves

Claims (7)

A pressure reducing device for an internal combustion engine, the pressure reducing device being assembled on a cam shaft, the cam shaft having an intake cam and an exhaust cam, wherein the cam shaft is provided with a receiving groove at the exhaust cam end, the exhaust The cam is provided with a pivot hole on the side of the receiving groove; the decompression device includes a base plate, a counterweight swing arm, an elastic component, a decompression camshaft and a shaft; the base plate is disposed on the camshaft and adjacent to the camshaft In the exhaust cam, the base plate is provided with a shaft hole, and the opposite end of the shaft hole is provided with a limiting hole, and the two ends between the shaft hole and the limiting hole are respectively provided with a consistent perforation and a fitting groove; One end of the swing arm is provided with a pivot hole corresponding to the shaft hole of the base plate, and the weight swing arm is provided with a hook hole adjacent to the pivot hole, and the weight swing arm is provided with a slot. The other end of the pivoting arm is provided with an outwardly protruding limiting protrusion, and one end of the limiting protrusion is slidably inserted into the limiting hole of the base; Fastened to the groove of the base plate, and the other end is hooked on the hook hole of the weight swing arm; the decompression camshaft is received a recessed camshaft having a base portion through which the camshaft has a base portion, and a cam portion extending from the base portion toward the exhaust cam, the cam portion having a circular arc surface on one side One side is a flat cut surface, and a flange portion is extended from an end edge of the cam portion. One end of the pivot portion is inserted into a pivot hole of the exhaust cam, and the base of the decompression cam shaft is extended to the cam portion. The other side of the lever is provided with a shifting portion, and one end of the pivoting portion is slidably inserted into the slot of the weight swing arm; one end of the shaft is inserted into the shaft hole of the base, The other end of the shaft is inserted into the pivot hole of the counterweight swing arm. The pressure reducing device for an internal combustion engine according to claim 1, wherein the base plate is tightly fitted to the cam shaft by another member, and the through hole is recessed from the base plate with the cam and the cam The receiving grooves of the shaft are formed together. The pressure reducing device for an internal combustion engine according to claim 1, wherein the slit of the weight swing arm is formed by an approximately parallel surface, and the opening of the slit is outward. The pressure reducing device of the internal combustion engine of claim 1 or 3, wherein an extension of the slot of the weight swing arm extends an extension of the end of the extension, and a limit projection is protruded toward a side of the extension. The pressure reducing device for an internal combustion engine according to claim 1, wherein the limiting hole is a long curved hole. The pressure reducing device for an internal combustion engine according to claim 1, wherein the slot is provided on the other end of the weight swing arm with respect to the hook hole. The pressure reducing device for an internal combustion engine according to claim 1, wherein the base plate is integrally formed on the cam shaft.