Camshaft assembly with pressure reduction structure

Abstract

The utility model relates to a cam shaft assembly with a pressure reduction structure. The cam shaft assembly comprises a shaft body provided with an exhaust cam and a flail block assembly. The flail block assembly is composed of a supporting base, a flail block and a step pin, the supporting base is in interference fit with the step pin through a step hole, and the flail block is hinged to the step pin. The exhaust cam is provided with a first pin hole which is in clearance fit with the end of the step pin. And the flail block is linked with the decompression pin through the transmission pin to realize decompression control when the engine is started and stopped. The torsional spring reset piece enables the flail block to reset, the supporting seat is matched with the shaft body through the supporting hole, and the limiting step ensures the assembly precision. The utility model has the advantages of integrated design, simplified assembly process and improved production efficiency, and is suitable for the motorcycle engine decompression system.

Description

Technical Field

[0001] This utility model relates to the field of motorcycle engine technology, and more specifically, to a camshaft assembly with a decompression structure. Background Technology

[0002] When a motorcycle engine starts, it needs to draw in new gas for compression. Near the end of the compression, a large compression resistance will be generated. If the pressure is not reduced at this time, the starting force will increase and starting will be very difficult. Therefore, a pressure reduction structure is needed to reduce the pressure and ensure that the engine starts smoothly.

[0003] In existing technologies, the decompression structure typically requires assembling components such as the slewing mechanism, support seat, and support pin onto the camshaft one by one, which severely restricts production efficiency.

[0004] For example, Chinese Patent Publication No. CN112360588A, published on February 12, 2021, discloses an invention entitled "Decompression Structure for a Motorcycle Engine". This application discloses a decompression structure for an engine, which requires the support pins, sling blocks, support seats and other structures to be assembled onto the shaft one by one during assembly, which reduces the overall production efficiency. Utility Model Content

[0005] This invention overcomes the shortcomings of existing technologies where the decompression assembly on a motorcycle engine camshaft requires the assembly of support pins, sling blocks, support seats, and other parts one by one onto the shaft body, severely restricting production efficiency. It provides a camshaft assembly with a decompression structure, which directly fits the sling block assembly, composed of sling blocks, support seats, and other structures, onto the shaft body during assembly, improving installation convenience and thus increasing production efficiency.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a camshaft assembly with a pressure reduction structure, comprising: a shaft body with an exhaust cam and a sling block assembly disposed on the shaft body;

[0007] The throwing block assembly includes a support base, a throwing block, and a step pin. The support base is provided with a step hole that is interference-fitted with the step pin. One end of the throwing block is hinged to the step pin.

[0008] The exhaust cam has a first pin hole on its end face near the sling block, and the end of the stepped pin away from the stepped hole is clearance-fitted with the first pin hole.

[0009] The flail block assembly is composed of a support seat, a flail block and a stepped pin, the stepped pin is in interference fit with the stepped hole on the support seat, the flail block is hinged on the stepped pin, so that the support seat, the flail block and the stepped pin form an integral assembly, and the positioning and installation of the flail block assembly can be realized by inserting the stepped pin into the first pin hole when assembling.

[0010] The first hole is arranged through the flail block, the stepped pin is provided with a stepped retaining ring on the outer side wall, and the stepped pin is in interference fit with the stepped hole after penetrating through the first hole.

[0011] The stepped retaining ring is arranged in the circumferential direction of the stepped pin, the stepped retaining ring and the support seat form a limiting ring groove after the stepped pin is in interference fit with the stepped hole, the first hole on the flail block is located in the limiting ring groove, the flail block is limited, and the flail block is prevented from being separated from the stepped pin.

[0012] The second hole is arranged at the end of the flail block away from the stepped hole, and the transmission pin is arranged in the second hole.

[0013] When the engine starts, the shaft body starts to rotate, when the shaft body reaches a certain rotating speed, the flail block is thrown out due to the centrifugal force, so that the pressure relief pin originally higher than the base circle of the exhaust cam becomes lower than the base circle of the exhaust cam, at this time, the pressure relief valve does not have the pressure relief effect.

[0014] The torsional spring reset member is arranged on the stepped pin, one end of the torsional spring reset member is inserted into the third hole, and the other end of the torsional spring reset member abuts against the shaft body.

[0015] The torsional spring reset member is arranged in the stepped pin, one end of the torsional spring reset member is inserted into the third hole, and the other end of the torsional spring reset member abuts against the shaft body.

[0016] The support pin is arranged on the end face of the exhaust cam close to the flail block, and the end face of the support pin away from the exhaust cam abuts against the support seat.

[0017] The arrangement of the supporting pin can increase the supporting area of the supporting seat on the supporting seat, support the supporting seat, prevent the supporting seat from having a cantilever structure in the process of later pressure assembly of the bearing, and ensure that the end surface of the supporting seat can keep vertical to the axis of the shaft body.

[0018] As preferred, the exhaust cam is provided with a third pin hole on the end surface close to the flyweight, and the supporting pin is inserted into the third pin hole.

[0019] The supporting pin is matched with the third pin hole through insertion, so that the supporting pin can be conveniently assembled.

[0020] As preferred, the center of the supporting seat is provided with a supporting hole matched with the shaft body.

[0021] The arrangement of the supporting hole facilitates the matching of the supporting hole with the shaft body.

[0022] As preferred, a limiting step is arranged on the shaft body, and the limiting step abuts against the end surface of the supporting seat after the flyweight assembly is installed on the shaft body.

[0023] After the flyweight assembly is installed on the shaft body, the limiting step abuts against the end surface of the supporting seat. Under the action of the limiting step, the limiting step can limit the supporting seat. When the supporting hole passes through the shaft body, the position of the supporting seat is installed in place when the supporting seat abuts against the limiting step.

[0024] As preferred, a supporting sleeve is arranged on the end surface of the supporting seat away from the flyweight, and the bearing is arranged on the supporting sleeve.

[0025] The supporting sleeve can increase the supporting area between the supporting seat and the shaft body, reduce the pressure intensity of the supporting seat on the shaft body, and make the supporting sleeve more stable on the shaft body.

[0026] As preferred, a plurality of supporting through holes are arranged on the supporting seat.

[0027] The supporting through holes can not only reduce the weight of the supporting seat, but also adjust the weight distribution of the whole flyweight assembly, and realize dynamic balance of the shaft body under high-speed rotation.

[0028] Compared with the prior art, the flyweight assembly is composed of the supporting seat, the flyweight and the step pin, the step pin is in interference fit with the step hole on the supporting seat, the step pin is fixed on the supporting seat, and the flyweight is hinged on the step pin, so that the supporting seat, the flyweight and the step pin form an integral assembly; when assembled, the supporting seat is sleeved on the shaft body, and the step pin is inserted into the first pin hole, so that the positioning and installation of the flyweight assembly can be realized. Therefore, the installation efficiency can be improved, and the production efficiency of the enterprise can be improved.

[0029] The limiting step is arranged on the shaft body, and after the flail block assembly is installed on the shaft body, the limiting step abuts against the end surface of the supporting seat, so that the assembly can be simpler, and the assembly efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is the sectional view of the utility model.

[0031] Figure 2 is the overall structural diagram of the utility model.

[0032] Figure 3 is the overall structural diagram of the flail block assembly of the utility model.

[0033] Figure 4 is the explosion view of the utility model.

[0034] Figure 5 is the explosion view of the utility model from another angle.

[0035] In the drawing: 1, exhaust cam, 11, limiting step;

[0036] 2, shaft body, 21, first pin hole, 22, second pin hole, 23, third pin hole;

[0037] 3, flail block assembly, 31, supporting seat, 311, step hole, 312, supporting hole, 313, supporting sleeve, 314, supporting through hole, 32, flail block, 321, first hole, 322, second hole, 323, third hole, 33, step pin, 331, first cylindrical section, 332, second cylindrical section, 333, step stop ring, 34, transmission pin, 35, bearing;

[0038] 4, torsion spring reset piece;

[0039] 5, pressure relief pin, 51, transmission groove;

[0040] 6, supporting pin. DETAILED DESCRIPTION

[0041] The technical scheme of the utility model will be further concretely described below by specific embodiments and in combination with the drawings:

[0042] Embodiment 1: referring to Figures 1 to 5 As shown in the figure, a camshaft assembly with pressure relief structure, comprising: the shaft body 1 provided with the exhaust cam 2 and the flail block assembly 3 arranged on the shaft body 1.

[0043] The flail block assembly 3 comprises a supporting seat 31, a flail block 32 and a step pin 33, the supporting seat 31 is provided with a step hole 311 in interference fit with the step pin 33; one end of the flail block 32 is hinged to the step pin 33;

[0044] The exhaust cam 2 is provided with a first pin hole 21 on the end face close to the flail 32, and the stepped pin 33 is in clearance fit with the first pin hole 21 at the end away from the stepped hole 311.

[0045] The flail assembly 3 in the utility model is composed of the support seat 31, the flail 32 and the stepped pin 33, the stepped pin 33 is in interference fit with the stepped hole 311 on the support seat 31, the stepped pin 33 can be fixedly arranged on the support seat 31, meanwhile, the flail 32 is hinged on the stepped pin 33, so that the support seat 31, the flail 32 and the stepped pin 33 form an integral assembly; during assembly, the support seat 31 is sleeved on the shaft body 1, and the stepped pin 33 is inserted into the first pin hole 21, so that the positioning and installation of the flail assembly 3 can be realized. Therefore, the installation efficiency can be improved, and the production efficiency of the enterprise can be improved.

[0046] In one of the embodiments, the flail 32 is provided with a first hole 321 penetrating therethrough, the stepped pin 33 is provided with a stepped blocking ring 333 on the outer side wall, and the stepped pin 33 is in interference fit with the stepped hole 311 after penetrating through the first hole 321; the stepped blocking ring 333 and the support seat 31 limit the flail 32.

[0047] The stepped blocking ring 333 is protrudingly arranged in the circumferential direction of the stepped pin 33, and after the stepped pin 33 is in interference fit with the stepped hole 311, the stepped blocking ring 333 cooperates with the support seat 31 to form a limiting ring groove, the first hole 321 on the flail 32 is located in the limiting ring groove, and the flail 32 is limited, thereby preventing the flail 32 from being separated from the stepped pin 33.

[0048] The stepped blocking ring 333 not only limits the flail 32, but also facilitates the installation of the torsional spring reset member 4. Specifically, the stepped blocking ring 333 divides the stepped pin 33 into two cylindrical segments, namely a first cylindrical segment 331 and a second cylindrical segment 332, the first cylindrical segment 331 cooperates with the first hole 321 and the stepped hole 311, and the outer side of the second cylindrical segment 332 is sleeved with the torsional spring reset member 4, and the second cylindrical segment 332 is in interference fit with the first pin hole 21. The stepped blocking ring 333 plays a blocking role on the outer side of the stepped pin 33, and provides a reasonable installation space for the torsional spring reset member 4.

[0049] The flail 32 is provided with a third hole 323, the torsional spring reset member 4 is sleeved around the stepped pin 33, one end of the torsional spring reset member 4 is inserted into the third hole 323, and the other end of the torsional spring reset member 4 abuts against the shaft body 1. The torsional spring reset member 4 can provide a restoring force for the flail 32, so that the flail 32 can be reset when the engine stops working.

[0050] The end of the flapper 32 away from the stepped hole 311 is provided with a second hole 322, a transmission pin 34 is arranged in the second hole 322; a second pin hole 22 is arranged on the end face of the exhaust cam 2 close to the flapper 32, a pressure relief pin 5 is rotatably arranged in the second pin hole 22, a transmission groove 51 is arranged on the end of the pressure relief pin 5 away from the second pin hole 22, and the end of the transmission pin 34 away from the second hole 322 is arranged in the transmission groove 51.

[0051] When the engine starts, the shaft body 1 starts to rotate, when the shaft body 1 reaches a certain rotating speed, the flapper 32 is thrown out due to the centrifugal force, so that the pressure relief pin 5 originally above the base circle of the exhaust cam 2 becomes lower than the base circle of the exhaust cam 2, at this time the pressure relief valve does not have pressure relief effect. When the engine is turned off, the torsional spring reset member 4 can reset the flapper 32,

[0052] At the same time, the effective working position of the pressure relief pin 5 is above the cam base circle, and the pressure relief effect is achieved, which ensures the effectiveness of the pressure relief valve when the engine starts next time. The torsional spring reset member 4 in the application can also use other forms of reset member, as long as the flapper 32 can rotate freely around the stepped pin 33 when the engine works, and the flapper 32 can return to the initial position under the action of the reset member when the engine stops working.

[0053] The center of the support seat 31 is provided with a support hole 312 matched with the shaft body 1. A limiting step 11 is arranged on the shaft body 1, and the limiting step 11 abuts against the end face of the support seat 31 after the flapper assembly 3 is installed on the shaft body 1. Under the action of the limiting step 11, the limiting step 11 can limit the support seat 31. When the support hole 312 passes through the shaft body 1, the position of the support seat 31 is installed in place when the support seat 31 abuts against the limiting step 11.

[0054] A support sleeve 313 is arranged on the end face of the support seat 31 away from the flapper 32, and a bearing 35 is arranged on the support sleeve 313. The bearing 35 is arranged on the support sleeve 313, so that when the shaft body 1 rotates, the balls in the bearing 35 rotate, and the outer surface of the bearing 35 can remain stationary, thereby saving the arrangement of related oil lines.

[0055] In one embodiment, a plurality of support through holes 314 are further arranged on the support seat 31. The support through holes 314 not only can reduce the weight of the support seat 31 as a whole, but also can adjust the weight distribution of the entire flapper assembly 3, so as to realize dynamic balance of the shaft body 1 under high speed rotation.

[0056] The flange block assembly 3 is composed of the supporting seat 31, the flange block 32 and the stepped pin 33, the stepped pin 33 is in interference fit with the stepped hole 311 on the supporting seat 31, the stepped pin 33 is fixedly arranged on the supporting seat 31, meanwhile, the flange block 32 is hinged on the stepped pin 33, so that the supporting seat 31, the flange block 32 and the stepped pin 33 form an integral assembly, the supporting seat 31 is sleeved on the shaft body 1, and the stepped pin 33 is inserted into the first pin hole 21, so that the positioning installation of the flange block assembly 3 is realized.

[0057] In addition, the limiting step 11 is arranged on the shaft body 1, the limiting step 11 abuts against the end surface of the supporting seat 31 after the flange block assembly 3 is installed on the shaft body 1, so that the assembly is more simple, and the assembly efficiency is improved.

[0058] Embodiment 2: refer to Figures 1 to 5 As shown in the figure, a camshaft assembly with a pressure reducing structure comprises a shaft body 1 provided with an exhaust cam 2 and a flange block assembly 3 arranged on the shaft body 1.

[0059] The flange block assembly 3 comprises a supporting seat 31, a flange block 32 and a stepped pin 33, the supporting seat 31 is provided with a stepped hole 311 in interference fit with the stepped pin 33, one end of the flange block 32 is hinged on the stepped pin 33,

[0060] The exhaust cam 2 is provided with a first pin hole 21 on the end surface close to the flange block 32, and the end portion of the stepped pin 33 away from the stepped hole 311 is in clearance fit with the first pin hole 21.

[0061] The flange block assembly 3 is composed of the supporting seat 31, the flange block 32 and the stepped pin 33, the stepped pin 33 is in interference fit with the stepped hole 311 on the supporting seat 31, the stepped pin 33 can be fixedly arranged on the supporting seat 31, meanwhile, the flange block 32 is hinged on the stepped pin 33, so that the supporting seat 31, the flange block 32 and the stepped pin 33 form an integral assembly, the supporting seat 31 is sleeved on the shaft body 1, and the stepped pin 33 is inserted into the first pin hole 21, so that the positioning installation of the flange block assembly 3 is realized. Therefore, the installation efficiency can be improved, and the production efficiency of the enterprise is improved.

[0062] In one embodiment, the first hole 321 is arranged through the flange block 32, the stepped blocking ring 333 is arranged on the outer side wall of the stepped pin 33, the stepped pin 33 is in interference fit with the stepped hole 311 after passing through the first hole 321, and the stepped blocking ring 333 and the supporting seat 31 limit the flange block 32.

[0063] The stepped blocking ring 333 is protruded in the circumferential direction of the stepped pin 33, and after the stepped pin 33 is in interference fit with the stepped hole 311, the stepped blocking ring 333 cooperates with the support seat 31 to form a limiting ring groove, and the first hole 321 on the flail block 32 is located in the limiting ring groove, thereby limiting the flail block 32 and preventing the flail block 32 from being separated from the stepped pin 33.

[0064] The stepped blocking ring 333 not only limits the flail block 32, but also facilitates the installation of the torsion spring reset member 4. Specifically, the stepped blocking ring 333 divides the stepped pin 33 into two cylindrical segments, i.e., a first cylindrical segment 331 and a second cylindrical segment 332, the first cylindrical segment 331 cooperates with the first hole 321 and the stepped hole 311, and the outer side of the second cylindrical segment 332 is sleeved with the torsion spring reset member 4, and the second cylindrical segment 332 is in interference fit with the first pin hole 21. The stepped blocking ring 333 plays a blocking role on the outer side of the stepped pin 33, thereby providing a reasonable installation space for the torsion spring reset member 4.

[0065] The flail block 32 is provided with a third hole 323, the torsion spring reset member 4 is sleeved on the outer periphery of the stepped pin 33, one end of the torsion spring reset member 4 is inserted into the third hole 323, and the other end of the torsion spring reset member 4 abuts against the shaft body 1. The torsion spring reset member 4 can provide a restoring force for the flail block 32, so that the flail block 32 can be reset when the engine stops working.

[0066] The end of the flail block 32 away from the stepped hole 311 is provided with a second hole 322, and the second hole 322 is provided with a transmission pin 34; the end face of the exhaust cam 2 close to the flail block 32 is provided with a second pin hole 22, the second pin hole 22 is rotatably provided with a pressure relief pin 5, the end of the pressure relief pin 5 away from the second pin hole 22 is provided with a transmission groove 51, and the end of the transmission pin 34 away from the second hole 322 is provided in the transmission groove 51.

[0067] When the engine starts, the shaft body 1 starts to rotate, and when the shaft body 1 reaches a certain rotating speed, the flail block 32 is flung out due to the centrifugal force, so that the pressure relief pin 5 originally above the base circle of the exhaust cam 2 becomes lower than the base circle of the exhaust cam 2, and at this time, the pressure relief valve does not have a pressure relief effect. When the engine is turned off, the action of the torsion spring reset member 4 can reset the flail block 32,

[0068] and the effective working position of the pressure relief pin 5 is above the cam base circle, thereby having a pressure relief effect and ensuring the effectiveness of the pressure relief valve when the engine starts next time. The torsion spring reset member 4 in the application can also be other forms of reset member, as long as the flail block 32 can rotate freely around the stepped pin 33 when the engine works, and the flail block 32 can return to the initial position under the action of the reset member when the engine stops working.

[0069] The center of the support seat 31 is provided with a support hole 312 matched with the shaft body 1. The shaft body 1 is provided with a limiting step 11, and the limiting step 11 abuts against the end surface of the support seat 31 after the flail block assembly 3 is installed on the shaft body 1. Under the action of the limiting step 11, the limiting step 11 can limit the position of the support seat 31. When the support hole 312 passes through the shaft body 1, the position of the support seat 31 is installed in place when the support seat 31 abuts against the limiting step 11.

[0070] The end surface of the support seat 31 away from the flail block 32 is provided with a support sleeve 313, and the bearing 35 is arranged on the support sleeve 313. The bearing 35 is arranged on the support sleeve 313, so that when the shaft body 1 rotates, the balls in the bearing 35 rotate, and the outer surface of the bearing 35 can remain in a stationary state, thereby eliminating the arrangement of the related oil circuit.

[0071] In one embodiment, a plurality of support through holes 314 are further arranged on the support seat 31. The support through holes 314 can not only reduce the weight of the support seat 31 as a whole, but also adjust the weight distribution of the entire flail block assembly 3, so as to realize dynamic balance of the shaft body 1 under high-speed rotation.

[0072] The structure of the present application is similar to that in Embodiment 1, except that the support pin 6 is arranged on the end surface of the exhaust cam 2 close to the flail block 32, and the end surface of the support pin 6 away from the exhaust cam 2 abuts against the support seat 31.

[0073] The support pin 6 can be arranged as needed. The arrangement of the support pin 6 can increase the support area of the support seat 31 on the support seat 31, support the support seat 31, prevent the support seat 31 from appearing cantilever structure in the process of later pressing the bearing 35, and ensure that the end surface of the support seat 31 can keep vertical to the axis of the shaft body 1.

[0074] In one embodiment, the third pin hole 23 is arranged on the end surface of the exhaust cam 2 close to the flail block 32, and the support pin 6 is inserted into the third pin hole 23. The support pin 6 is matched with the third pin hole 23 in the form of insertion, which can facilitate the assembly of the support pin 6.

[0075] The flail block assembly 3 in the utility model is composed of the support seat 31, the flail block 32 and the step pin 33, the step pin 33 is in interference fit with the step hole 311 on the support seat 31, so that the step pin 33 is fixedly arranged on the support seat 31, meanwhile, the flail block 32 is hinged on the step pin 33, so that the support seat 31, the flail block 32 and the step pin 33 form an integral assembly; when assembling, the support seat 31 is sleeved on the shaft body 1, and the step pin 33 is inserted into the first pin hole 21, so that the positioning and installation of the flail block assembly 3 can be realized. Therefore, the efficiency of installation can be improved, and the production efficiency of enterprises can be improved.

[0076] In addition, the shaft body 1 is provided with a limiting step 11, after the flyweight assembly 3 is installed on the shaft body 1, the limiting step 11 abuts against the end face of the supporting seat 31, so that the assembly can be simpler, and the assembly efficiency is improved.

[0077] The above-mentioned embodiments are only the preferred schemes of the present application, and do not limit the present application in any form, and other variants and modifications are still possible without exceeding the technical schemes recorded in the claims.

Claims

1. A camshaft assembly with a pressure-reducing structure, characterized in that, include: A shaft with an exhaust cam and a sling assembly mounted on the shaft; The throwing block assembly includes a support base, a throwing block, and a step pin. The support base is provided with a step hole that is interference-fitted with the step pin. One end of the throwing block is hinged to the step pin. The exhaust cam has a first pin hole on its end face near the sling block, and the end of the stepped pin away from the stepped hole is clearance-fitted with the first pin hole.

2. The camshaft assembly with a pressure-reducing structure according to claim 1, characterized in that, The first hole is provided through the swing block, and a step retaining ring is provided on the outer wall of the step pin. After the step pin passes through the first hole, it is interference-fitted with the step hole; the step retaining ring and the support seat limit the swing block.

3. The camshaft assembly with a pressure-reducing structure according to claim 1 or 2, characterized in that, A second hole is provided at the end of the blower block away from the stepped hole, and a transmission pin is provided in the second hole; a second pin hole is provided on the end face of the exhaust cam near the blower block, and a pressure reducing pin is rotatably provided in the second pin hole; a transmission groove is provided at the end of the pressure reducing pin away from the second pin hole, and the end of the transmission pin away from the second hole is located in the transmission groove.

4. The camshaft assembly with a pressure-reducing structure according to claim 1, characterized in that, It also includes a torsion spring reset component; the throwing block is provided with a third hole, the torsion spring reset component is sleeved on the stepped pin, one end of the torsion spring reset component is inserted into the third hole, and the other end of the torsion spring reset component abuts against the shaft.

5. The camshaft assembly with a pressure-reducing structure according to claim 1, characterized in that, A support pin is provided on the end face of the exhaust cam near the sling block, and the end face of the support pin away from the exhaust cam abuts against the support seat.

6. The camshaft assembly with a pressure-reducing structure according to claim 5, characterized in that, The exhaust cam has a third pin hole on its end face near the sling block, and the support pin is inserted into the third pin hole.

7. The camshaft assembly with a pressure-reducing structure according to claim 1, 2, 4, or 5, characterized in that, The support base has a support hole in the center, which fits into the shaft.

8. The camshaft assembly with a pressure-reducing structure according to claim 7, characterized in that, A limiting step is provided on the shaft. After the swing block assembly is installed on the shaft, the limiting step abuts against the end face of the support seat.

9. The camshaft assembly with a pressure-reducing structure according to claim 7, characterized in that, A support sleeve is provided on the end face of the support base away from the throwing block, and the bearing is installed on the support sleeve.

10. The camshaft assembly with a pressure-reducing structure according to claim 7, characterized in that, Several support holes are also provided through the support base.

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