阅读说明：本技术 新型二冲程多缸柴油机扫气装置 (Novel two-stroke multi-cylinder diesel engine scavenging device ) 是由 覃壮革 沈捷 左俊杰 于 2021-04-28 设计创作，主要内容包括：本发明公开了一种新型二冲程多缸柴油机扫气装置,安装于气缸体的腰部上。新型二冲程多缸柴油机扫气装置包括：壳体、气门帽、扫气阀、阀座、进气道以及气门弹簧。壳体,固定于气缸体的腰部上,且壳体的一端具有进气口。气门帽,设置于壳体内,且气门帽与气缸体内的凸轮轴相连接。扫气阀,设置于壳体内,且扫气阀的一端与气门帽固定连接。阀座,设置于进气口内,且扫气阀的另一端位于阀座与进气口之间。进气道,进气道的一端与进气口相连通。以及气门弹簧,套设于扫气阀的一端上,并与气门帽相连接。借此,本发明的新型二冲程多缸柴油机扫气装置,结构简单合理,可以精准的实现定时定量扫气,且布置灵活。(The invention discloses a novel scavenging device of a two-stroke multi-cylinder diesel engine, which is arranged on the waist part of an air cylinder body. Novel two-stroke multi-cylinder diesel engine scavenging device includes: casing, valve cap, scavenging valve, disk seat, intake duct and valve spring. And the shell is fixed on the waist of the cylinder block, and one end of the shell is provided with an air inlet. And the valve cap is arranged in the shell and is connected with the camshaft in the cylinder body. And the scavenging valve is arranged in the shell, and one end of the scavenging valve is fixedly connected with the valve cap. And the valve seat is arranged in the air inlet, and the other end of the scavenging valve is positioned between the valve seat and the air inlet. And one end of the air inlet channel is communicated with the air inlet. And the valve spring is sleeved on one end of the scavenging valve and is connected with the valve cap. Therefore, the novel two-stroke multi-cylinder diesel engine scavenging device is simple and reasonable in structure, can accurately realize timing and quantitative scavenging, and is flexible in arrangement.)

1. The utility model provides a novel two-stroke multi-cylinder diesel engine scavenge device, installs on the waist of cylinder block, its characterized in that, novel two-stroke multi-cylinder diesel engine scavenge device includes:

the shell is fixed on the waist of the cylinder block, and one end of the shell is provided with an air inlet;

the valve cap is arranged in the shell and is connected with the camshaft in the cylinder body;

the scavenging valve is arranged in the shell, and one end of the scavenging valve is fixedly connected with the valve cap;

the valve seat is arranged in the air inlet, and the other end of the scavenging valve is positioned between the valve seat and the air inlet;

one end of the air inlet channel is communicated with the air inlet; and

the valve spring is sleeved on one end of the scavenging valve and is connected with the valve cap;

the air inlet channel, the annular air inlet cavity and the tangential air inlet which are communicated in sequence are arranged in the air cylinder body, and the other end of the air inlet channel is communicated with the air inlet channel of the air cylinder body;

the exhaust valve is connected with the camshaft through a rocker arm, a push rod and a tappet, and the camshaft can control the opening and closing of the exhaust valve and the scavenging valve.

2. A novel scavenging apparatus for a two-stroke multi-cylinder diesel engine as claimed in claim 1, further comprising a valve guide provided on said one end of said scavenging valve.

3. A novel scavenging apparatus for a two-stroke multi-cylinder diesel engine according to claim 2, further comprising a valve oil seal provided on said valve guide.

4. A novel scavenging apparatus for a two-stroke multi-cylinder diesel engine as claimed in claim 1, wherein said housing is fixed to said cylinder block by bolts and a sealing structure is provided between said housing and said cylinder block.

5. A novel scavenging apparatus for a two-stroke multi-cylinder diesel engine according to claim 1, wherein a valve cap guide hole is further provided in said cylinder block, and said valve cap is connected to said camshaft through said valve cap guide hole.

6. A novel two-stroke multi-cylinder diesel engine scavenging device as claimed in claim 1, wherein when the piston in the cylinder block descends, the exhaust valve opens, and when the piston continues to descend, the intake port opens, so that the pressurized air enters the cylinder block through the intake passage, the cylinder block intake passage, the annular intake chamber and the tangential intake port in sequence, and forms the uniflow scavenging.

7. A novel two-stroke multi-cylinder diesel engine scavenging device as claimed in claim 6, wherein said intake port is closed when said piston is traveling upward.

Technical Field

The invention relates to the technical field of two-stroke diesel engines, in particular to a novel two-stroke multi-cylinder diesel engine scavenging device.

Background

The scavenging mechanism of the modern two-stroke diesel engine mainly comprises a crankcase scavenging structure and a scavenging pump scavenging structure or a combined structure of the crankcase scavenging structure and the scavenging pump scavenging structure. The crankcase scavenging is realized by utilizing a piston to move downwards and compressing the mixed gas in the crankcase to enter the upper part of the piston; the scavenging pump is used for scavenging air, and air is forcibly fed from scavenging holes on the circumference of the lower part of the cylinder through the scavenging pump. If the scavenging is to sweep the mixed combustible gas into the cylinder, the scavenging is used for the two-stroke gasoline engine. If fresh air is swept into the cylinder by the scavenge pump, a naturally aspirated two-stroke diesel engine is used. In the case of a supercharged two-stroke diesel engine, the compressor supplies fresh charge directly for scavenging.

At present, a scavenging port is generally arranged at the lower part of a cylinder of a two-stroke diesel engine, and the scavenging port is partially or completely opened and closed by utilizing the shielding effect of the up-and-down motion of a piston; an exhaust port is generally arranged above a scavenging port of a cylinder, and air distribution is completed by matching a piston with the air port. In order to exhaust the burnt exhaust gas and to fill the cylinder with fresh air, a two-stroke diesel engine must be equipped with a dedicated scavenging pump (supercharger) driven by a moving part and a scavenging tank for storing pressurized air. A circle of air inlets are uniformly distributed at the lower part of the cylinder, and an exhaust valve is arranged on the cylinder cover. And the air distribution is completed by the matching of the piston and the air port or the matching of the piston and the exhaust valve.

As shown in fig. 1, the scavenging process of a conventional two-stroke diesel engine: after the pressure of air is increased by the scavenging pump, the air enters the cylinder through an air chamber arranged outside the cylinder and an air inlet end at the lower part of the cylinder, and drives waste gas upwards along the center line of the cylinder to be discharged out of the cylinder from an exhaust port (an exhaust port at the circumference of the cylinder or an exhaust valve on a cylinder cover) above the scavenging port.

In the traditional multi-cylinder two-stroke diesel engine, a crosshead structure is arranged between a connecting rod and a piston to prolong the length of a cylinder, a sealing structure is arranged between the piston and the crosshead, and a cavity between the sealing structure and the piston is used as a scavenging cavity. The inlet of the scavenging cavity is provided with a one-way valve which is matched with the scavenging port on the cylinder in an opening and closing way to realize timing scavenging, and the sealing structure prevents the scavenging from entering the crankcase.

In the prior art, the gas distribution mechanism of the two-stroke diesel engine is used as a reference, the top gas inlet mode is adopted, and the reverse spiral upward scavenging is realized by the structure after the gas flow directly rushes to the lower part of the cylinder, which is called reverse tumble scavenging.

No matter which intake structure is adopted, the current two-stroke diesel engine has the following disadvantages:

1. or the opening and closing of the scavenging port is controlled completely by the shielding effect of the piston, the influence of the piston stroke and the gas distribution phase is large, the scavenging process time is short, the scavenging is incomplete and thorough, the scavenging quality is poor, and the heat efficiency is low;

2. the reverse tumble scavenging is completely dependent on the movement of a gas flow field for scavenging, so that multiple uncontrollable factors exist, and the problem of unclean scavenging also exists;

3. the multi-cylinder two-stroke diesel engine with crosshead and one-way valve to control scavenging time has lengthened cylinder, increased height of the whole engine and complicated structure.

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Disclosure of Invention

The invention aims to provide a novel scavenging device of a two-stroke multi-cylinder diesel engine, which has a simple and reasonable structure, can accurately realize timing and quantitative scavenging, and is flexible in arrangement.

In order to achieve the purpose, the invention provides a novel scavenging device of a two-stroke multi-cylinder diesel engine, which is arranged on the waist part of a cylinder body. Novel two-stroke multi-cylinder diesel engine scavenging device includes: casing, valve cap, scavenging valve, disk seat, intake duct and valve spring. And the shell is fixed on the waist of the cylinder block, and one end of the shell is provided with an air inlet. And the valve cap is arranged in the shell and is connected with the camshaft in the cylinder body. And the scavenging valve is arranged in the shell, and one end of the scavenging valve is fixedly connected with the valve cap. And the valve seat is arranged in the air inlet, and the other end of the scavenging valve is positioned between the valve seat and the air inlet. And one end of the air inlet channel is communicated with the air inlet. And the valve spring is sleeved on one end of the scavenging valve and is connected with the valve cap. The cylinder body is internally provided with a cylinder body inlet channel, an annular inlet cavity and a tangential inlet which are sequentially communicated, and the other end of the inlet channel is communicated with the cylinder body inlet channel. The exhaust valve is connected with the camshaft through a rocker arm, a push rod and a tappet, and the camshaft can control the opening and closing of the exhaust valve and the scavenging valve.

In an embodiment of the invention, the novel scavenging device of the two-stroke multi-cylinder diesel engine further comprises a valve guide pipe which is arranged at one end of the scavenging valve.

In an embodiment of the invention, the novel scavenging device of the two-stroke multi-cylinder diesel engine further comprises a valve oil seal arranged on the valve guide pipe.

In one embodiment of the present invention, the housing is fixed to the cylinder block by bolts, and a seal structure is provided between the housing and the cylinder block.

In one embodiment of the present invention, a valve cap guide hole is further formed in the cylinder block, and the valve cap is connected to the camshaft through the valve cap guide hole.

In one embodiment of the present invention, when the piston in the cylinder block moves downward, the exhaust valve is opened, and when the piston continues to move downward, the intake port is opened, so that the pressurized air sequentially enters the cylinder block through the intake port, the intake port of the cylinder block, the annular intake cavity and the tangential intake port, and forms the direct-flow scavenging.

In one embodiment of the invention, the inlet port is closed when the piston is moving upwards.

Compared with the prior art, the novel scavenging device for the two-stroke multi-cylinder diesel engine, disclosed by the invention, has a simple and reasonable structure, can realize scavenging of the multi-cylinder two-stroke diesel engine by additionally installing the scavenging device outside the engine, can perform timing and quantitative scavenging on a cylinder by controlling the camshaft, solves the problems of incomplete scavenging of the two-stroke diesel engine and low inflation efficiency and the defects of an air inlet structure, can accurately realize timing and quantitative scavenging, and is flexible to arrange.

Drawings

FIG. 1 is a schematic illustration of a prior art two-stroke diesel engine breathing process;

FIG. 2 is a structural schematic diagram of a scavenging device of a novel two-stroke multi-cylinder diesel engine, which is arranged on a cylinder block, according to an embodiment of the invention;

fig. 3 is a schematic view of an intake structure of a cylinder block according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a novel scavenging device of a two-stroke multi-cylinder diesel engine according to an embodiment of the invention.

Description of the main reference numerals:

1-shell, 2-air inlet, 3-valve cap, 4-camshaft, 5-scavenging valve, 6-valve seat, 7-air inlet, 8-valve spring, 9-cylinder air inlet, 10-annular air inlet cavity, 11-tangential air inlet, 12-exhaust valve, 13-rocker arm, 14-push rod, 15-tappet, 16-valve guide pipe, 17-valve oil seal, 18-valve cap guide hole, 19-piston and 20-cylinder body.

Detailed Description

The following detailed description of the present invention is provided in conjunction with the accompanying drawings, but it should be understood that the scope of the present invention is not limited to the specific embodiments.

Throughout the specification and claims, unless explicitly stated otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element or component but not the exclusion of any other element or component.

Fig. 2 is a schematic structural diagram of a scavenging device of a novel two-stroke multi-cylinder diesel engine according to an embodiment of the invention, which is mounted on a cylinder block 20. Fig. 3 is a schematic view of an intake structure of the cylinder block 20 according to an embodiment of the present invention. Fig. 4 is a schematic structural diagram of a novel scavenging device of a two-stroke multi-cylinder diesel engine according to an embodiment of the invention.

As shown in fig. 2 to 4, a scavenging device for a novel two-stroke multi-cylinder diesel engine according to a preferred embodiment of the present invention is mounted on the waist portion of a cylinder block 20. Novel two-stroke multi-cylinder diesel engine scavenging device includes: the valve comprises a shell 1, a valve cap 3, a scavenging valve 5, a valve seat 6, an air inlet 7 and a valve spring 8. The cylinder block 20 includes a housing 1 fixed to a waist portion thereof, and the housing 1 has an intake port 2 at one end thereof. And a valve cap 3 disposed in the housing 1, the valve cap 3 being connected to a camshaft 4 in the cylinder block 20. And the scavenging valve 5 is arranged in the shell 1, and one end of the scavenging valve 5 is fixedly connected with the valve cap 3. And the valve seat 6 is arranged in the air inlet 2, and the other end of the scavenging valve 5 is positioned between the valve seat 6 and the air inlet 2. One end of the intake passage 7 communicates with the intake port 2. And the valve spring 8 is sleeved on one end of the scavenging valve 5 and is connected with the valve cap 3. The cylinder body 20 is provided with a cylinder body inlet 9, an annular inlet chamber 10 and a tangential inlet 11 which are communicated in sequence, and the other end of the inlet 7 is communicated with the cylinder body inlet 9. The cylinder block 20 further includes an exhaust valve 12 therein, the exhaust valve 12 is connected to the camshaft 4 through a rocker arm 13, a pushrod 14, and a tappet 15, and the camshaft 4 can control opening and closing of the exhaust valve 12 and the scavenging valve 5.

In one embodiment of the present invention, the scavenging device of the novel two-stroke multi-cylinder diesel engine further comprises a valve guide 16 arranged at one end of the scavenging valve 5. The novel scavenging device of the two-stroke multi-cylinder diesel engine also comprises a valve oil seal 17 which is arranged on the valve guide pipe 16.

In an embodiment of the present invention, the housing 1 is fixed to the cylinder block 20 by bolts, and a seal structure is provided between the housing 1 and the cylinder block 20. The cylinder block 20 also has a valve cap guide hole 18 therein, and the valve cap 3 is connected to the camshaft 4 through the valve cap guide hole 18.

In one embodiment of the present invention, when the piston 19 in the cylinder block 20 moves downward, the exhaust valve 12 is opened, and when the piston 19 continues to move downward, the intake port 2 is opened, so that the charge air enters the cylinder block 20 through the intake passage 7, the cylinder block intake passage 9, the annular intake chamber 10, and the tangential intake port 11 in this order, and the uniflow scavenging is performed. When the piston 19 moves upward, the intake port 2 is closed.

In practical application, the novel scavenging device for the two-stroke multi-cylinder diesel engine is arranged at the waist position of the cylinder block 20, can be applied to the two-stroke multi-cylinder diesel engine through simple modification, and particularly comprises the following components: a scavenging device is provided at the waist of the cylinder block 20, and a scavenging valve 5 is provided in the scavenging device, and the scavenging valve 5 and the exhaust valve 12 can share a single camshaft 4 to control opening and closing. The scavenging device is composed of a shell 1, a valve cap 3, a valve spring 8, a valve oil seal 17, a valve guide pipe 16, a scavenging valve 5 and a valve seat 6. The shell 1 is provided with an air inlet 2 and an air inlet channel 7, the installation and sealing structure of the device is required to be arranged at the waist part of the cylinder, and the device is fixed and sealed on the cylinder body 20 through bolts and gaskets; an annular air inlet cavity 10 is arranged around the cylinder block 20 and is communicated with an air inlet 7 of the scavenging device through an air inlet 9 of the cylinder block, and a plurality of tangential air inlets 11 are arranged on the wall of the cylinder block 20 along the circumference. The exhaust valve 12 is controlled to open and close by the camshaft 4, the tappet 15, the pushrod 14, and the rocker arm 13. The cylinder block 20 is provided with a block inlet duct 9, an inlet chamber, a tangential inlet port 11 and a valve cap guide bore 18. It should be noted that, through one-dimensional analysis and cam profile and position design of the lower air inlet 2, the optimal air distribution phase can be realized to obtain the optimal air exchange effect. When the piston 19 descends, the exhaust valve 12 is opened, and most of the pressure and exhaust gas in the cylinder is exhausted; the piston 19 continues to move downwards, the air inlet 2 is opened, the scavenging valve 5 is opened, the pressurized air tangentially enters the cylinder and rotates upwards to form direct-current scavenging; until the piston 19 moves upwards to close the air inlet 2, the air inlet process is completed. Wherein, the scavenging valve 5 and the exhaust valve 12 can share one camshaft 4 to control the opening and the closing; furthermore, the scavenging device can use an electromagnetic valve to replace a set of mechanism of the valve spring 8, the valve oil seal 17, the valve guide pipe 16, the inlet valve and the valve seat ring, and adopts electronic control to realize timing opening and closing scavenging. The cylinder block 20 is provided at a cylinder waist portion thereof with a mounting and sealing structure of a scavenging device and a guide hole of the valve cap 3. An annular air inlet cavity 10 is arranged around the cylinder and communicated with an air inlet 7 of a scavenging device through an air inlet 9 of the cylinder body, and a plurality of tangential air inlets 11 are arranged on the wall of the cylinder along the circumference. The scavenging means is fastened to the cylinder block 20 by bolts with a seal structure in between. The piston 19 moves up and down in the cylinder, when a circle of tangential air inlet 11 on the cylinder is positioned below a piston ring, if a scavenging valve (a traditional two-stroke method) is not arranged, high-pressure air or mixed gas enters a crankcase through a gap between the outer circle of a piston skirt and the cylinder, the pressure of the crankcase is increased, a large amount of gas and oil blowby of an engine breather are caused, and the scavenging valve 5 has the significance that under the condition, air inlet is cut off, and no high-pressure gas enters the crankcase.

In conclusion, the novel scavenging device for the two-stroke multi-cylinder diesel engine has the following beneficial effects:

1. the timing and quantitative external scavenging of the traditional two-stroke multi-cylinder diesel engine can be realized by simple modification;

2. the position of the lower scavenging port in the height direction can be flexibly arranged according to the requirement, and the lower scavenging port is very practical when the stroke length of the piston 19 is required to be changed;

3. the height of the engine cannot be increased by adopting the device;

4. the device combines the electronic control technology, and can more accurately realize the timing and quantitative scavenging of the multi-cylinder two-stroke diesel engine.

5. Simple structure is reasonable, and realization that can be accurate is scavenging regularly and quantitatively, and arranges in a flexible way.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and its practical application to enable one skilled in the art to make and use various exemplary embodiments of the invention and various alternatives and modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims and their equivalents.