A camshaft device with multi-stage oil supply

Abstract

The present invention relates to the technical field of diesel engines, and particularly to a camshaft device with multi-stage fuel supply, which includes a camshaft, an oil pump cam group arranged at one end of the camshaft, a cavity formed in the camshaft, a screw arranged at the end of the oil pump cam group away from the oil pump cam group, and the oil pump cam group at least includes a first oil pump cam and a second oil pump cam. A connecting rod is arranged in the cavity, and an expansion medium is filled in the cavity. A first plunger is arranged between the connecting rod and the oil pump cam group; a second plunger is arranged between the connecting rod and the screw; a sealed space for accommodating the expansion medium is formed between the first plunger and the second plunger. By arranging two or more oil pump cam groups at a certain angle, the present invention utilizes the characteristic of large thermal shrinkage rate of paraffin to increase the fuel supply advance angle during cold start, which not only ensures the cold start smoke color quality but also ensures the compliance of emissions.

Description

Technical Field

[0001] This invention patent relates to the technical field of diesel engines, and particularly to a camshaft device with multi-stage fuel supply. Background Art

[0002] In traditional single-cylinder water-cooled engines, the oil pump cam is fixed on the camshaft. Regardless of the engine temperature change, the camshaft always rotates at a set angle, and the fuel supply advance angle remains unchanged. During cold start of a single-cylinder water-cooled engine, there is a large amount of smoke and a very loud noise in the exhaust pipe. After the engine temperature rises, the smoke color returns to normal. Increasing the fuel supply advance angle can make the smoke color normal during cold start, but the emissions fail to meet the regulatory standards. Therefore, it is necessary to provide a device that can automatically change the fuel supply advance angle according to the engine temperature change, ensuring both normal smoke color during cold start and compliance with emission standards.

[0003] The technical problem to be solved by this invention patent is: To overcome the technical problems in the above technology, this invention patent provides a camshaft device with multi-stage fuel supply, including a camshaft, an oil pump cam group arranged at one end of the camshaft, a cavity opened in the camshaft, and a screw arranged at the end of the camshaft far from the oil pump cam group. Moreover, the oil pump cam group at least includes a first oil pump cam and a second oil pump cam. A connecting rod is arranged in the cavity, and an expansion medium is filled in the cavity. Among them, a first plunger is arranged between the connecting rod and the oil pump cam group; a second plunger is arranged between the connecting rod and the screw; a sealed space for accommodating the expansion medium is formed between the first plunger and the second plunger.

[0004] Further, the diameter of the first plunger is larger than that of the second plunger.

[0005] Further, a baffle is fixed on the screw, and a spring is sleeved on the screw. One end of the spring abuts against the baffle, and the other end abuts against the bottom of the cavity.

[0006] Further, rubber rings are sleeved on both the first plunger and the second plunger, and the outer diameter of the rubber ring abuts against the inner diameter of the cavity.

[0007] Further, the number of the rubber rings is four, and they are evenly distributed at one end of the first plunger and the second plunger close to the screw.

[0008] Further, an installation groove is opened on the camshaft, and the oil pump cam group is installed in the installation groove.

[0009] Further, the expansion medium is paraffin.

[0010] Beneficial effects: This invention patent is a camshaft device with multi-stage fuel supply. After two or more oil pump cams rotate at a certain angle and are arranged in sequence, taking advantage of the large thermal shrinkage rate of paraffin, when the engine is cold, it operates with a larger fuel supply advance angle, increasing the in-cylinder explosion pressure and temperature, thereby improving the combustion environment and obtaining better exhaust smoke color. At this time, due to the thrust of paraffin melting and expanding, the oil pump cams with a smaller angle participate in the work, ensuring the emission performance of the engine. Description of the Drawings

[0011] Figure 1 is a schematic diagram of the overall structure of this invention patent;

[0012] Figure 2 is a schematic diagram of the structure of the oil pump cam group of this invention patent;

[0013] Figure 3 is a schematic diagram of the camshaft structure of this invention patent;

[0014] Figure 4 is a schematic diagram of the structure of the first oil pump cam of this invention patent;

[0015] Figure 5 is a schematic diagram of the connecting rod structure of this invention patent;

[0016] Figure 6 is a schematic diagram of the structure of the second plunger of this invention patent;

[0017] Figure 7 is a schematic diagram of the spring structure of this invention patent;

[0018] In the figure:

[0019] 100, camshaft; 101, mounting groove; 110, first oil pump cam; 111, first plunger; 120, second oil pump cam; 121, second plunger; 130, cavity; 131, connecting rod; 140, screw; 141, baffle; 142, spring; 150, rubber ring. Detailed Embodiment

[0020] In order to enable those skilled in the art to better understand the technical solution of this invention patent, the following will clearly and completely describe the technical solution in the embodiments of this invention patent with reference to the accompanying drawings in the embodiments of this invention patent. Obviously, the described embodiments are only a part of the embodiments of this invention patent, rather than all of the embodiments. Based on the embodiments in this invention patent, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this invention patent.

[0021] As used herein, "one embodiment" or "an embodiment" refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention patent. In the description of the present invention patent, it should be understood that the orientation or positional relationship indicated by terms such as "upper", "top", "bottom", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention patent and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention patent. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. Moreover, the terms "first", "second", etc. are used to distinguish similar objects and do not necessarily have to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention patent described herein can be implemented in an order other than those illustrated or described herein.

[0022] Embodiment 1, such as Figures 1 to 6As shown in the figure, a camshaft 100 device with multi-stage fuel supply includes a camshaft 100, a fuel pump cam group arranged at one end of the camshaft 100, a cavity 130 opened in the camshaft 100, a screw 140 arranged at the end of the camshaft away from the fuel pump cam group, and the fuel pump cam group at least includes a first fuel pump cam 110 and a second fuel pump cam 120. A connecting rod 131 is arranged in the cavity 130, and an expansion medium is filled in the cavity 130. Among them, a first plunger 111 is arranged between the connecting rod 131 and the fuel pump cam group; a second plunger 121 is arranged between the connecting rod and the screw; a sealed space for accommodating the expansion medium is formed between the first plunger 111 and the second plunger 121. The fuel pump cam group is slidably arranged at one end of the camshaft 100, and a screw 140 is fixedly arranged at the other end. The cavity 130 is opened along the axis of the camshaft 100. One end of the connecting rod 131 abuts against the fuel pump cam group, and the other end abuts against the screw 140. The expansion medium is filled around the connecting rod 131. The first plunger 111 is located in the cavity 130, and one end of the first plunger 111 abuts against the fuel pump cam group, and the other end abuts against the connecting rod 131; the second plunger 121 is located in the cavity 130, and one end of the second plunger 121 abuts against the connecting rod 131, and the other end abuts against the screw 140. The expansion medium is filled between the first plunger 111 and the second plunger 121. When the system is at a low temperature, the first fuel pump cam 110 participates in the work, enabling the engine to work with a larger fuel supply advance angle, ensuring the cold engine smoke color quality. When the system temperature rises to a high temperature, the expansion medium is heated and melts and expands, pushing the fuel pump cam group to move left. When the paraffin is completely melted, the second fuel pump cam 120 participates in the work. At this time, the engine works with a smaller fuel supply advance angle, ensuring the emission performance and also ensuring the smoke color quality during hot operation.

[0023] The diameter of the first plunger 111 is larger than that of the second plunger 121. The diameter difference between the first plunger 111 and the second plunger 121 results in different acting forces after the paraffin melts. The acting force of the smaller diameter is smaller. In the sealed space formed by the cavity 130 and the rubber ring 150, the two piston rods together with the entire fuel pump cam group move left, so that the second fuel pump cam 120 participates in the work.

[0024] A baffle 141 is fixed on the screw 140, and a spring 142 is sleeved on the screw 140. Among them, one end of the spring 142 abuts against the baffle 141, and the other end abuts against the bottom of the cavity 130. After the expansion medium is heated and melts and expands, pushing the fuel pump cam group to move left, under the action of the spring 142, the baffle 141 is pushed left to make up for the paraffin space, thereby amplifying the displacement of the fuel pump cam.

[0025] A rubber ring 150 is sleeved on both the first plunger 111 and the second plunger 121, and the outer diameter of the rubber ring 150 abuts against the inner diameter of the cavity 130. The rubber ring 150 can confine the expansion medium in the cavity 130, thus ensuring the sealing performance in the cavity 130 and preventing the expansion medium from flowing out of the cavity 130.

[0026] The number of the rubber rings 150 is four, and they are evenly distributed at one end of the first plunger 111 and the second plunger 121 close to the screw 140. Evenly arranging two sets of the rubber rings 150 can play a better sealing role for the expansion medium in the cavity 130.

[0027] An installation groove 101 is formed on the camshaft 100, and the oil pump cam group is installed in the installation groove 101. The installation groove 101 is located at one end of the camshaft 100 away from the screw 140, and the size of the installation groove 101 is adapted to the size of the oil pump cam group.

[0028] The expansion medium is paraffin. The expansion medium is not limited to paraffin, and it can also be other media with a relatively high shrinkage rate.

[0029] The above are only the preferred embodiments of the present invention patent, and are not intended to limit the present invention patent. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention patent shall be included in the protection scope of the present invention patent.

Claims

1. A camshaft device with multi-stage oil supply, characterized in that: including a camshaft, an oil pump cam group arranged at one end of the camshaft, a cavity opened in the camshaft, and a screw arranged at the end of the camshaft away from the oil pump cam group, and, the oil pump cam group at least includes a first oil pump cam and a second oil pump cam, a connecting rod is arranged in the cavity, and the cavity is filled with an expansion medium, wherein, a first plunger is arranged between the connecting rod and the oil pump cam group; a second plunger is arranged between the connecting rod and the screw; a sealing space for accommodating the expansion medium is formed between the first plunger and the second plunger.

2. The camshaft device for multi-stage oil supply according to claim 1, characterized in that: the diameter of the first plunger is larger than the diameter of the second plunger.

3. The camshaft device for multi-stage oil supply according to claim 1, characterized in that: a baffle is fixed on the screw, and a spring is sleeved on the screw, wherein, one end of the spring abuts against the baffle, and the other end abuts against the bottom of the cavity.

4. The camshaft device for multi-stage oil supply according to claim 1, characterized in that: rubber rings are sleeved on both the first plunger and the second plunger, and the outer diameter of the rubber ring abuts against the inner diameter of the cavity.

5. The camshaft device for multi-stage oil supply according to claim 4, characterized in that: the number of the rubber rings is four, and they are evenly distributed at one end of the first plunger and the second plunger close to the screw.

6. The camshaft device for multi-stage oil supply according to claim 1, characterized in that: an installation groove is opened on the camshaft, and the oil pump cam group is installed in the installation groove.

7. The camshaft device for multi-stage oil supply according to claim 1, characterized in that: the expansion medium is paraffin.

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