Camshaft structure of engine
By designing crescent centrifugal arms, coupling pins, tension springs and sealing balls in the engine camshaft, forming an airway for exhaust and decompression, the problems of reduced pressure performance and unstable decompression in the prior art are solved. , achieving more stable engine start and operation.
Patent Information
- Application Number
- CN202421193640.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-29
- Publication Date
- 2025-02-11
- Estimated Expiration
- 2034-05-29
AI Technical Summary
The pressure reducing valve design of existing engine camshafts has problems such as reduced pressure reduction performance and unstable pressure reduction, resulting in poor engine start-up.
An engine camshaft structure is designed, using crescent centrifugal arms, coupling pins, tension springs and sealing balls. The exhaust grooves on the pressure reducing pins are combined with the sealing balls to form an airway for exhaust and pressure reduction. , ensure the stability of decompression.
It improves the pressure relief performance and stability of the engine camshaft, ensuring that the engine can start and operate smoothly in both motion and non-sporty states.
Smart Images
Figure CN222457536U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of engines and relates to an engine camshaft structure. Background Art
[0002] The camshaft is a component in a piston engine. Its function is to control the opening and closing of the valve. When a general-purpose gasoline engine is pneumatic, a cylinder decompression device is generally used on the general-purpose gasoline engine to make its start smoother. At present, a pressure reducing valve is installed on the timing driven gear of the camshaft. However, when in use, the movable end of the centrifugal arm of the current pressure reducing valve only limits the initial position of the centrifugal arm through a limiter. After long-term use, the centrifugal arm will be away from the driven gear, resulting in a decrease in the decompression performance of the camshaft. In addition, during the operation of the centrifugal arm, it cannot move along a fixed track, and the pressure reducing valve is unstable. Utility Model Content
[0003] The utility model aims to solve the above problems in the prior art and proposes an engine camshaft structure.
[0004] The purpose of the utility model can be achieved through the following technical solutions: an engine camshaft structure, including a camshaft body, an intake cam, an exhaust cam, a timing driven gear, a mounting plate and a pressure reducing valve assembly, the pressure reducing valve assembly including a pressure reducing pin, a centrifugal arm, a connecting pin and a tension spring, one end of the centrifugal arm is fixed to the mounting plate by a swing block rivet, characterized in that an exhaust through hole is provided on the exhaust cam, an isolation sleeve is embedded in the exhaust through hole, a sealing ball is provided in the isolation sleeve, an exhaust groove is provided on the side of the pressure reducing pin close to the isolation sleeve, when the exhaust cam is exhausted, the sealing ball falls into the exhaust groove, and an airway is formed between the sealing ball and the exhaust through hole to perform exhaust pressure reduction.
[0005] In the above-mentioned engine camshaft structure, a mounting groove for installing a centrifugal arm is provided on the camshaft body, a through hole is provided on the mounting groove, one end of the connecting pin passes through the through hole and is vertically engaged with the centrifugal arm and the other end is fixed on the decompression pin, one end of the tension spring is connected to the centrifugal arm, and the other end is fixed to the mounting plate by a spring rivet.
[0006] In the above-mentioned engine camshaft structure, a connecting portion is provided at one end of the centrifugal arm, the connecting portion is C-shaped, and the connecting pin is vertically clamped on the notch of the connecting portion.
[0007] In the above-mentioned engine camshaft structure, the timing driven gear, the intake cam, the exhaust cam, the mounting plate and the pressure reducing valve assembly are sequentially arranged on the camshaft body, and the intake cam, the exhaust cam and the mounting plate are integrally formed. By integrally forming the intake cam, the exhaust cam, the mounting plate and the camshaft body, the processing is convenient, the processing efficiency is improved, and the processing cost is reduced.
[0008] In the above-mentioned engine camshaft structure, the centrifugal arm is crescent-shaped.
[0009] In the above-mentioned engine camshaft structure, a limit rod is also provided on the mounting plate. The setting of the limit rod can limit the running track of the centrifugal arm, thereby improving the stability of decompression.
[0010] Compared with the prior art, the utility model has a simple structure. When the engine is in a moving state, the camshaft body rotates at a high speed, and the centrifugal arm rotates toward one side of the limit rod under the action of centrifugal force. During the rotation, the pressure reducing pin is driven to rotate through the connection of the connecting pin, so that the exhaust groove on the pressure reducing pin rotates to below the sealing ball, and the sealing ball falls into the exhaust groove, so that an airway is formed between the sealing ball and the exhaust through hole for exhaust and pressure reduction. Conversely, when the engine is in a non-moving state, the tension spring pulls back through the elastic force, so that the centrifugal arm returns to its initial state, and the exhaust groove on the pressure reducing pin lifts the sealing ball during the process of rotating back, so that the sealing ball and the exhaust through hole are sealed, and the airway is closed. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Figure 1 It is a structural schematic diagram of the utility model;
[0012] Figure 2 It is a side view of the utility model;
[0013] Figure 3 It is an exploded view of the utility model.
[0014] In the figure, 1. camshaft body; 2. intake cam; 3. exhaust cam; 4. timing driven gear; 5. mounting plate; 6. pressure reducing valve assembly; 61. pressure reducing pin; 62. centrifugal arm; 63. connecting pin; 64. tension spring; 8. connecting part; 9. exhaust through hole; 10. isolation sleeve; 11. exhaust groove; 12. limit rod; 13. mounting groove; 14. swing block rivet; 15. spring rivet; 16. sealing ball. DETAILED DESCRIPTION
[0015] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments. Example
[0016] like Figures 1 to 3As shown, an engine camshaft structure includes a camshaft body 1, an intake cam 2, an exhaust cam 3, a timing driven gear 4, a mounting plate 5 and a pressure reducing valve assembly 6, wherein the pressure reducing valve assembly 6 includes a pressure reducing pin 61, a centrifugal arm 62, a connecting pin 63 and a tension spring 64, one end of the centrifugal arm 62 is fixed to the mounting plate 5 by a swing block rivet 14, the centrifugal arm 62 is crescent-shaped, one end of the centrifugal arm 62 is provided with a connecting portion 8, the connecting portion 8 is C-shaped, and the connecting pin 63 is vertically clamped on the notch of the connecting portion 8. In this way, the connecting pin 63 can be prevented from being separated from the centrifugal arm 62.
[0017] The camshaft body 1 is provided with a mounting groove 13 for mounting the centrifugal arm 62, and the mounting groove 13 is provided with a through hole. One end of the connecting pin 63 passes through the through hole and is vertically engaged with the centrifugal arm 62, and the other end is fixed on the decompression pin 61. One end of the tension spring 64 is connected to the centrifugal arm 62, and the other end is fixed to the mounting plate 5 through a spring rivet 15.
[0018] The exhaust cam 3 is provided with an exhaust through hole 9, in which an isolation sleeve 10 is embedded, and a sealing ball 16 is arranged in the isolation sleeve 10. In the present embodiment, the sealing ball 16 is a steel ball, and may also be a sphere made of other materials.
[0019] The decompression pin 61 is provided with an exhaust groove 11 on one side close to the isolation sleeve 10. The exhaust groove 11 is a horizontal section and is not recessed inward. When the exhaust cam 3 is exhausted, the sealing ball 16 falls into the exhaust groove 11, and an airway is formed between the sealing ball 16 and the exhaust through hole 9 to exhaust and reduce pressure.
[0020] In the above-mentioned engine camshaft structure, the timing driven gear 4, the intake cam 2, the exhaust cam 3, the mounting plate 5 and the pressure reducing valve assembly 6 are sequentially arranged on the camshaft body 1, and the intake cam 2, the exhaust cam 3 and the mounting plate 5 are integrally formed. By integrally forming the intake cam 2, the exhaust cam 3, the mounting plate 5 and the camshaft body 1, the processing is convenient, the processing efficiency is improved, and the processing cost is reduced.
[0021] The mounting plate 5 is also provided with a limit rod 12. The setting of the limit rod 12 can limit the running track of the centrifugal arm 62, thereby improving the stability of the decompression.
[0022] The utility model has a simple structure. When the engine is in a moving state, the camshaft body 1 rotates at a high speed, and the centrifugal arm 62 rotates toward one side of the limit rod 12 under the action of centrifugal force. During the rotation, the pressure relief pin 61 is driven to rotate through the connection of the connecting pin 63, so that the exhaust groove 11 on the pressure relief pin 61 rotates to below the sealing ball 16, so that the sealing ball 16 falls into the exhaust groove 11, so that an airway is formed between the sealing ball 16 and the exhaust through hole 9 for exhaust and pressure relief. On the contrary, when the engine is in a non-moving state, the tension spring 64 pulls back through the elastic force, so that the centrifugal arm 62 returns to its initial state. During the process of the exhaust groove 11 on the pressure relief pin 61 rotating back, the sealing ball 16 is lifted up, so that the sealing ball 16 and the exhaust through hole 9 are sealed, and the airway is closed.
[0023] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.
Claims
1. An engine camshaft structure, comprising a camshaft body (1), an intake cam (2), an exhaust cam (3), a timing driven gear (4), a mounting plate (5) and a pressure reducing valve assembly (6), wherein the pressure reducing valve assembly (6) comprises a pressure reducing pin (61), a centrifugal arm (62), a connecting pin (63) and a tension spring (64), wherein one end of the centrifugal arm (62) is fixed to the mounting plate (5) by a swing block rivet (14), characterized in that: The exhaust cam (3) is provided with an exhaust through hole (9), an isolation sleeve (10) is embedded in the exhaust through hole (9), a sealing ball (16) is arranged in the isolation sleeve (10), an exhaust groove (11) is provided on the side of the pressure reducing pin (61) close to the isolation sleeve (10), the sealing ball (16) falls into the exhaust groove (11), and an airway is formed between the sealing ball (16) and the exhaust through hole (9) to perform exhaust pressure reduction.
2. An engine camshaft structure according to claim 1, characterized in that: The camshaft body (1) is provided with a mounting groove (13) for mounting a centrifugal arm (62), and the mounting groove (13) is provided with a through hole. One end of the connecting pin (63) passes through the through hole and is vertically engaged with the centrifugal arm (62), and the other end is fixed to the decompression pin (61). One end of the tension spring (64) is connected to the centrifugal arm (62), and the other end is fixed to the mounting plate (5) through a spring rivet (15).
3. The engine camshaft structure according to claim 1, characterized in that: A connecting portion (8) is provided at one end of the centrifugal arm (62), the connecting portion (8) is C-shaped, and the connecting pin (63) is vertically clamped on the notch of the connecting portion (8).
4. The engine camshaft structure according to claim 1, characterized in that: The timing driven gear (4), the intake cam (2), the exhaust cam (3), the mounting plate (5) and the pressure reducing valve assembly (6) are sequentially arranged on the camshaft body (1); the intake cam (2), the exhaust cam (3) and the mounting plate (5) are integrally formed.
5. The engine camshaft structure according to claim 1, characterized in that: The centrifugal arm (62) is crescent-shaped.
6. The engine camshaft structure according to claim 1, characterized in that: A limiting rod (12) is also provided on the installation plate (5).