CN116357452A - Double-crankshaft serial piston type four-stroke engine - Google Patents

Abstract

The invention belongs to the technical field of piston engines, and particularly relates to a double-crankshaft serial piston type four-stroke engine, which comprises a cylinder body and a serial piston assembly, wherein the cylinder body comprises a first cylinder section and a second cylinder section which are arranged along a first direction; the tandem piston assembly comprises a center rod structure, a first piston and a second piston; the first piston is arranged in the first cylinder section in a sliding manner along a first direction and divides the first cylinder section into a first chamber and a second chamber; the second piston slides along the first direction and sets up in the second jar section, and separates the second jar section into third cavity and fourth cavity, and the first end and the first piston fixed connection of centre pole structure, the second end and the second piston fixed connection of centre pole structure stretch out outside the jar body. Compared with the existing four-stroke engine, the double-crankshaft serial piston four-stroke engine provided by the invention has higher efficiency, and simultaneously has higher power-weight ratio and power-volume ratio.

Description

Double-crankshaft serial piston type four-stroke engine

Technical Field

The invention belongs to the technical field of piston engines, and particularly relates to a double-crankshaft serial piston type four-stroke engine.

Background

The four-stroke engine includes an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke during one working cycle. The piston has two dead points, namely an upper dead point and a lower dead point, the speed of the piston is zero at the dead point, the speed near the middle position reaches the maximum value, the piston has the process of increasing the speed from zero to the maximum value and then decreasing the speed from the maximum value to zero in each stroke, the power is required to be input in the acceleration process, and the power is required to be output in the deceleration process.

In the existing four-stroke engine, each piston corresponds to a connecting rod and a crankshaft, only the acceleration of the piston in the expansion stroke is powered by hot gas, and the power input and output in the other three strokes are realized through the transmission of the connecting rod. When power is input and output through the connecting rod, the big end and the small end of the connecting rod are respectively rubbed with the crank shaft neck and the piston pin to cause energy loss, and the loss is more than 20% of the total loss of the engine according to related data; at the same time, the reaction force of the connecting rod to the piston causes the piston to have a vertical component force to the cylinder wall, which has the following adverse effects:

1. friction is generated in the running process of the piston, so that energy loss is caused, and according to related data, the loss of the piston is approximately half of the total loss of the engine;

2. the abrasion of the piston and the cylinder wall can be accelerated, and the service life of the engine is shortened;

3. forming a knock imagination, generating noise;

4. to cope with this vertical component force, it is necessary to reinforce the strength of the cylinder block, which results in more material consumption, thereby increasing the manufacturing cost of the engine and increasing the volume and weight of the engine block.

Disclosure of Invention

The invention aims to provide a double-crankshaft serial piston type four-stroke engine, which aims to solve the technical problems of the existing four-stroke engine.

In order to achieve the above purpose, the invention adopts the following technical scheme: there is provided a double-crankshaft tandem piston four-stroke engine, one unit basic structure of which includes: the cylinder body, the serial piston assembly and the crankshaft connecting rod assembly; wherein the cylinder block comprises a first cylinder section and a second cylinder section arranged along a first direction; the first cylinder section is provided with a first air inlet valve, a second air inlet valve, a first air outlet valve, a second air outlet valve, a first fuel injection mechanism and a second fuel injection mechanism, and the second cylinder section is provided with a third air inlet valve, a fourth air inlet valve, a third air outlet valve, a fourth air outlet valve, a third fuel injection mechanism and a fourth fuel injection mechanism;

the tandem piston assembly includes a center rod structure, a first piston, and a second piston; the first piston is arranged in the first cylinder section in a sliding manner along the first direction, the first cylinder section is divided into a first chamber and a second chamber, the first air inlet valve, the first exhaust valve and the first fuel injection mechanism are respectively communicated with the first chamber, and the second air inlet valve, the second exhaust valve and the second fuel injection mechanism are respectively communicated with the second chamber; the second piston is arranged in the second cylinder section in a sliding manner along the first direction, the second cylinder section is divided into a third chamber and a fourth chamber, and the third intake valve, the third exhaust valve and the third fuel injection mechanism are respectively communicated with the third chamber; the fourth intake valve, the fourth exhaust valve and a fourth fuel injection mechanism are respectively communicated with the fourth chamber; the first piston is arranged at the first end of the central rod structure, the second piston is arranged in the middle of the central rod structure, the second end of the central rod structure extends out of the cylinder body, and the axis of the central rod structure, the central line of the first cylinder section and the central line of the second cylinder section are overlapped;

the crankshaft connecting rod assembly comprises a first connecting rod, a second connecting rod, a first crankshaft and a second crankshaft; the first end of the first connecting rod is rotationally connected with the first crankshaft, the first end of the second connecting rod is rotationally connected with the second crankshaft, and the second end of the first connecting rod and the second end of the second connecting rod are respectively rotationally connected with the second end of the center rod structure; the first crankshaft and the second crankshaft synchronously rotate and turn reversely, the first connecting rod and the second connecting rod are symmetrically arranged by taking the axis of the center rod structure as a symmetrical axis, and the first crankshaft and the second crankshaft are symmetrically arranged by taking the axis of the center rod structure as a symmetrical axis

According to the double-crankshaft serial piston type four-stroke engine, the first cylinder section and the second cylinder section are arranged along the first direction, the first cylinder section is divided into the first cavity and the second cavity through the first piston, the second cylinder section is divided into the third cavity and the fourth cavity through the second piston, and the first cylinder section, the second cylinder section, the first piston and the second piston form the four-cylinder engine; the synchronous and equidirectional movement of the first piston and the second piston is realized through the center rod structure, so that the double-crankshaft serial piston type four-stroke engine does not need a connecting rod and a crankshaft structure to realize the transmission of power between four strokes, one chamber is positioned in an expansion stroke in each stroke of the first piston and the second piston, namely, each stroke of the first piston and the second piston is powered by the chamber positioned in the expansion stroke; meanwhile, as the first crankshaft and the second crankshaft are symmetrically arranged, the first connecting rod and the second connecting rod are symmetrically arranged, the component force of the central rod structure to the first connecting rod, which is perpendicular to the cylinder wall, is opposite to the component force of the central rod structure to the second connecting rod, which is perpendicular to the cylinder wall, so that the component force and the component force can be offset, friction force between the first piston and the cylinder wall and friction force between the second piston and the cylinder wall can be greatly reduced, thereby reducing energy loss caused by friction, slowing down abrasion between the first piston and the cylinder wall and between the second piston and the cylinder wall, prolonging the service life of the engine, thoroughly solving the knocking phenomenon, avoiding noise caused by the knocking phenomenon, and reducing the manufacturing cost, volume and weight of the engine without strengthening the strength of the cylinder body.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments or the description of the prior art will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a dual crankshaft tandem piston four-stroke engine according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a first piston or a second piston of a dual-crankshaft tandem piston four-stroke engine according to an embodiment of the present invention;

fig. 3 is a cross-sectional view of fig. 2 taken along section line A-A.

Wherein, each reference sign in the figure:

1-a cylinder body; 11-a first cylinder section; 111-a first chamber; 112-a second chamber; 12-a second cylinder section; 121-a third chamber; 122-a fourth chamber; 13-a first inlet valve; 14-a second intake valve; 15-a third intake valve; 16-fourth intake valve; 17-a first exhaust valve; 18-a second exhaust valve; 19-a third exhaust valve; 20-fourth exhaust valve; 201-a first fuel injection mechanism; 202-a second fuel injection mechanism; 203-a third fuel injection mechanism; 204-a fourth fuel injection mechanism; a 2-series piston assembly; 21-a first piston; 211-lubrication channels; 212-a second opening; 22-a second piston; 23-a central rod structure; 231-a central rod; 2312-hollow structure; 232-coat; 2321—a first opening; 2322-a third opening; 2323-fourth openings; 24-connecting piece; 3-crankshaft connecting rod assembly; 31-a crankcase; 32-a first crankshaft; 33-a first link; 34-a second crankshaft; 35-a second link; 36-a first gear; 37-a second gear; 4-a first end cap; 5-a second end cap; 51-cooling lubrication channels; 6-a third end cap; 7-cooling jacket; 8-an air intake passage; 9-an exhaust passage; 30-a first camshaft mechanism; 40-a second camshaft mechanism; 50-lube connector.

Detailed Description

In order to make the technical problems, technical schemes and beneficial effects to be solved more clear, the invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.

It will be understood that when an element is referred to as being "mounted" or "disposed" on another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

It is to be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate or are based on the orientation or positional relationship shown in the drawings, merely to facilitate description of the present application and simplify description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be configured and operated in a particular orientation, and therefore should not be construed as limiting the present application.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

Referring to fig. 1, a description will now be given of a double-crankshaft tandem piston type four-stroke engine provided by the present invention, wherein a unit basic structure of the double-crankshaft tandem piston type four-stroke engine includes a cylinder 1 and a tandem piston assembly 2;

wherein the cylinder block 1 comprises a first cylinder segment 11 and a second cylinder segment 12 arranged in a first direction; wherein a first intake valve 13, a second intake valve 14, a first exhaust valve 17, a second exhaust valve 18, a first fuel injection mechanism 201, and a second fuel injection mechanism 202 are provided on the first cylinder segment 11; and a third intake valve 15, a fourth intake valve 16, a third exhaust valve 19, a fourth exhaust valve 20, a third fuel injection mechanism 203, and a fourth fuel injection mechanism 204 are provided on the second cylinder segment 12.

While the tandem piston assembly 2 comprises a central rod structure 23, a first piston 21 and a second piston 22; the first piston 21 is slidably disposed in the first cylinder segment 11 in the first direction and partitions the first cylinder segment 11 into a first chamber 111 and a second chamber 112, the first intake valve 13, the first exhaust valve 17, and the first fuel injection mechanism 201 are respectively communicated with the first chamber 111, and the second intake valve 14, the second exhaust valve 18, and the second fuel injection mechanism 202 are respectively communicated with the second chamber 112; the second piston 22 is slidably disposed in the second cylinder section 12 in the first direction and partitions the second cylinder section 12 into a third chamber 121 and a fourth chamber 122, and the third intake valve 15, the third exhaust valve 19, and the third fuel injection mechanism 203 are respectively in communication with the third chamber 121; the fourth intake valve 16, the fourth exhaust valve 20, and the fourth fuel injection mechanism 204 are each in communication with the fourth chamber 122; the first direction is the moving direction of the first piston 21 and the second piston 22; the first piston 21 is arranged at a first end of the central rod structure 23, the second piston 22 is arranged in the middle of the central rod structure 23, the second end of the central rod structure 23 extends out of the cylinder body 1, and the axis of the central rod structure 23, the centre line of the first cylinder section 11 and the centre line of the second cylinder section 12 coincide. The fixed connection of the first piston 21 and the second piston 22 can thus be achieved by means of the central rod structure 23, so that the first piston 21 and the second piston 22 can be moved synchronously and in the same direction. In this way, the first cylinder section 11, the second cylinder section 12, and the first and second pistons 21 and 22 constitute one four-cylinder four-stroke engine, which can simplify the structure and design of the engine as compared with a conventional four-cylinder four-stroke engine which needs to have a structure of four cylinders and four pistons.

The fuel used by the double-crankshaft serial piston type four-stroke engine can be diesel oil, gasoline or compressed natural gas, and can also be other fuels, and the fuel can be specifically selected according to actual needs.

For convenience of explanation, the working principle of the double-crankshaft tandem piston type four-stroke engine will be described below with the first direction being the "left-right direction" and the first cylinder segment 11 being on the left side and the second cylinder segment 12 being on the right side as an example.

Setting the initial state that the first piston 21 and the second piston 22 are positioned at the leftmost side, the first intake valve 13 and the first exhaust valve 17 are in a closed state, the first chamber 111 is opened for an expansion stroke, a large amount of energy is released after the fuel in the first chamber 111 is combusted and pushes the first piston 21 to move rightwards, then the second intake valve 14 and the second exhaust valve 18 are in a closed state, and the second chamber 112 enters a compression stroke; since the first piston 21 and the second piston 22 move synchronously and in the same direction, when the first chamber 111 does work and pushes the first piston 21 to move rightward, the second piston 22 moves synchronously to the right, the volume of the third chamber 121 increases to enter an intake stroke, the third intake valve 15 is opened, the fourth exhaust valve 20 is in an opened state, the third exhaust valve 19 and the fourth intake valve 16 are in a closed state, and air enters the third chamber 121 through the third intake valve 15; the volume of the fourth chamber 122 decreases into the exhaust stroke and the gas of the fourth chamber 122 is exhausted through the fourth exhaust valve 20.

When the first piston 21 and the second piston 22 move to the far right, the first stroke of each chamber is ended, the second chamber 112 opens the expansion stroke, pushing the first piston 21 to move leftward, the second piston 22 moves leftward simultaneously, the first chamber 111 enters the exhaust stroke, the third chamber 121 enters the compression stroke, and the fourth chamber 122 enters the suction stroke.

When the piston moves to the far left, the second stroke of each chamber is ended, the third chamber 121 opens the expansion stroke, pushing the second piston 22 to move to the right, the first piston 21 moves to the right synchronously, the first chamber 111 enters the suction stroke, the second chamber 112 enters the exhaust stroke, and the fourth chamber 122 enters the compression stroke.

When the piston moves to the far right, the third stroke of each chamber is ended, the fourth chamber 122 opens the expansion stroke, pushing the second piston 22 to move to the left, the first piston 21 moves synchronously to the left, the first chamber 111 enters the compression stroke, the second chamber 112 enters the suction stroke, and the third chamber 121 enters the exhaust stroke.

When the piston moves to the far left, the fourth stroke of each chamber is completed, i.e. the four chambers all complete a complete four-stroke cycle, and then the following table is referred to.

It will be appreciated that an ignition element for igniting the mixed gas, such as a spark plug, may be further disposed on the cylinder 1, and the structure of the ignition element is the prior art and will not be described herein.

As can be seen from the description of the working principle of the above-described dual-crankshaft tandem piston type four-stroke engine, in this embodiment, one chamber is in an expansion stroke in each of the first piston 21 and the second piston 22, so that each of the first piston 21 and the second piston 22 is powered by the chamber in the expansion stroke, so that the dual-crankshaft tandem piston type four-stroke engine does not need to implement power transmission between four strokes by a connecting rod and a crankshaft structure.

According to the double-crankshaft serial piston type four-stroke engine, the first cylinder section 11 and the second cylinder section 12 are arranged along the first direction, the first cylinder section 11 is divided into the first chamber 111 and the second chamber 112 through the first piston 21, the second cylinder section 12 is divided into the third chamber 121 and the fourth chamber 122 through the second piston 22, so that the first cylinder section 11, the second cylinder section 12, the first piston 21 and the second piston 22 form the engine with one four cylinders, and compared with the traditional four-cylinder four-stroke engine which needs to have the structure with four cylinders and four pistons, the structure and the design of the double-crankshaft serial piston type four-stroke engine can be simplified, and the weight and the volume of the double-crankshaft serial piston type four-stroke engine are reduced; the first piston 21 and the second piston 22 synchronously and co-directionally move through the center rod structure 23, so that the double-crankshaft serial piston type four-stroke engine does not need a connecting rod and a crankshaft structure to realize power transmission between four strokes, one chamber in each stroke of the first piston 21 and the second piston 22 is in an expansion stroke, namely, each stroke of the first piston 21 and the second piston 22 is powered by the chamber in the expansion stroke.

In practical applications, a plurality of dual-piston dual-crankshaft tandem piston four-stroke engines may be used in parallel, for example: a twelve-cylinder engine can be formed by connecting three double-piston double-crankshaft serial-connection piston type four-stroke engines in parallel.

In one embodiment, the dual crankshaft tandem piston four-stroke engine further includes a crankshaft connecting rod assembly 3, the crankshaft connecting rod assembly 3 including a first connecting rod 33, a second connecting rod 35, a first crankshaft 32, and a second crankshaft 34; the first end of the first connecting rod 33 is rotatably connected with the first crankshaft 32, the first end of the second connecting rod 35 is rotatably connected with the second crankshaft 34, and the second end of the first connecting rod 33 and the second end of the second connecting rod 35 are respectively rotatably connected with the second end of the central rod structure 23; the first crankshaft 32 rotates in synchronization with the second crankshaft 34 and turns in opposite directions, and the first connecting rod 33 and the second connecting rod 35 are disposed axisymmetrically about the axis of the center rod structure 23, and the first crankshaft 32 and the second crankshaft 34 are disposed axisymmetrically about the axis of the center rod structure 23.

In a conventional four-cylinder four-stroke engine, a piston generally corresponds to a connecting rod and a crankshaft, so that the piston has a component force perpendicular to the cylinder wall of the cylinder body 1 due to the action of the connecting rod on the piston, friction is generated between the piston and the cylinder wall in the running process of the piston, energy loss is caused, abrasion of the piston and the cylinder wall is accelerated, the service life of the piston is shortened, a knocking phenomenon is caused, noise is generated, and meanwhile, in order to cope with the perpendicular component force, the strength of the cylinder body 1 needs to be enhanced, more materials are consumed, and therefore the manufacturing cost and the machine body volume and weight are increased. In the present embodiment, since the first crankshaft 32 and the second crankshaft 34 are symmetrically disposed, the first connecting rod 33 and the second connecting rod 35 are symmetrically disposed, the component force of the central rod structure 23 perpendicular to the cylinder wall of the first connecting rod 33 and the component force of the central rod structure 23 perpendicular to the cylinder wall of the second connecting rod 35 are opposite, so that the two components can be offset, the friction force between the first piston 21 and the cylinder wall and between the second piston 22 and the cylinder wall can be greatly reduced, the energy loss caused by friction is reduced, the wear between the first piston 21 and the cylinder wall and between the second piston 22 and the cylinder wall is slowed down, the service lives of the first piston 21 and the second piston 22 are prolonged, the knocking phenomenon can be thoroughly solved, the noise generated due to the knocking phenomenon is avoided, and the strength of the cylinder body 1 is not required to be enhanced, thereby the manufacturing cost, the volume and the weight of the engine are reduced.

In an embodiment, the crankshaft connecting rod assembly 3 further comprises a crankcase 31, the crankcase 31 being located on the side of the second cylinder section 12 facing away from the first cylinder section 11, and the second end of the central rod structure 23 extending into the crankcase 31. Specifically, the first connecting rod 33, the second connecting rod 35, the first crankshaft 32 and the second crankshaft 34 are rotatably mounted on the crankcase 31 such that the crankshaft connecting rod assembly 3 is formed as a single unit that is both aesthetically pleasing and effective in protecting the second end of the center rod structure 23, the first connecting rod 33, the second connecting rod 35, the first crankshaft 32 and the second crankshaft 34.

In one embodiment, the crankshaft connecting rod assembly 3 further includes a first gear 36 and a second gear 37 that are meshed with each other, the first gear 36 and the second gear 37 are symmetrically disposed about the axis of the center rod structure 23 as a symmetry axis, the first crankshaft 32 is fixedly connected to the first gear 36, and the second crankshaft 34 is fixedly connected to the second gear 37. So that the first gear 36 and the second gear 37 can synchronously and reversely rotate, thereby driving the first crankshaft 32 and the second crankshaft 34 to synchronously and reversely rotate.

In one embodiment, the crankshaft connecting rod assembly 3 further includes a connecting member 24 coupled to the center rod structure 23, and the second end of the first connecting rod 33 and the second end of the second connecting rod 35 are both rotatably coupled to the connecting member 24. By providing the connection piece 24, a connection of the central rod structure 23 with the first link 33 and of the central rod structure 23 with the second link 35 is achieved.

In one embodiment, as shown in fig. 2 and 3, the center rod structure 23 includes a center rod 231 and an outer sleeve 232, wherein the outer sleeve 232 is sleeved outside the center rod 231, and the first piston 21 and the second piston 22 are fixedly connected with the outer sleeve 232 and can be fixedly connected with the center rod 231 through the outer sleeve 232; the center rod 231 has a hollow structure 2312 for inputting lubricating oil, and at the same time, a first opening 2321 is formed in the outer sleeve 232, the first piston 21 and the second piston 22 are provided with lubricating channels 211, the hollow structure 2312, the first opening 2321 and the lubricating channels 211 are sequentially communicated, and a second opening 212 communicated with the lubricating channels 211 is formed in a side wall of the first piston 21 in clearance fit with the first cylinder section 11 and a side wall of the second piston 22 in clearance fit with the second cylinder section 12. When lubricating oil is introduced into the center rod 231 through the hollow structure 2312, the lubricating oil enters the lubricating channel 211 through the first opening 2321 communicated with the hollow structure 2312 and then enters the space between the first piston 21 and the cylinder wall and the space between the second piston 22 and the cylinder wall through the second opening 212 communicated with the lubricating channel 211, so that lubrication is provided between the first piston 21 and the cylinder wall and between the second piston 22 and the cylinder wall, abrasion of the first piston 21, the second piston 22 and the cylinder body 1 is effectively slowed down, the service life of the double-crankshaft serial piston type four-stroke engine is prolonged, and meanwhile cooling of the serial piston assembly 2 is realized.

In one embodiment, as shown in fig. 1, the dual crankshaft tandem piston four-stroke engine further includes a lubrication oil connector 50 for inputting lubrication oil into the hollow structure 2312, the lubrication oil connector 50 being connected to an end of the center rod 231 protruding outside the cylinder 1. Specifically, the end of the center rod 231 facing away from the first piston 21 is connected to the lubrication connector 50 and is connected to a lubrication source through the lubrication connector 50, so that lubrication can be pumped into the hollow structure 2312 of the center rod 231.

Further, a third opening 2322 is provided at an end of the outer jacket 232 protruding outside the cylinder 1, the third opening 2322 communicating with the gap between the center rod 231 and the outer jacket 232. A fourth opening 2323 is also provided in the outer sleeve 232, and lubricating oil in the lubrication channel 211 can enter the gap between the center rod 231 and the outer sleeve 232 through the fourth opening 2323, and then flow back to the crankcase 31 from the third opening 2322.

In an embodiment, a first end cover 4, a second end cover 5 and a third end cover 6 are arranged in the cylinder body 1 at intervals along the first direction, wherein the first end cover 4 and the second end cover 5 are respectively positioned at two ends of the first cylinder section 11, and the second end cover 5 and the third end cover 6 are positioned at two ends of the second cylinder section 12. So that the cylinder block 1 can be divided into a first cylinder section 11 and a second cylinder section 12 by the first end cap 4, the second end cap 5 and the third end cap 6. Specifically, the middle parts of the second end cover 5 and the third end cover 6 are respectively provided with a via hole, and the center rod structure 23 is arranged on the second end cover 5 and the third end cover 6 in a penetrating way through the via holes.

In one embodiment, a cooling and lubrication channel 51 is provided in the second end cap 5 that extends in a second direction perpendicular to the first direction. This allows the first cylinder section 11 and the second cylinder section 12 to be cooled by injecting a cooling medium into the cooling-lubrication channel 51, while also providing lubrication. The cooling medium may be in a liquid state or a gaseous state, and is not particularly limited.

In an embodiment, the double-crankshaft tandem piston four-stroke engine further comprises a cooling jacket 7, and the cooling jackets 7 are respectively arranged on the first cylinder section 11 and the second cylinder section 12 for cooling the cylinder block 1. By injecting the cooling medium into the cooling jacket 7 in this way, the cooling of the cylinder 1 can be accelerated.

In one embodiment, the dual crankshaft tandem piston four-stroke engine is further provided with an intake passage 8 and an exhaust passage 9, the first intake valve 13, the second intake valve 14, the third intake valve 15, and the fourth intake valve 16 are respectively in communication with the intake passage 8, and the first exhaust valve 17, the second exhaust valve 18, the third exhaust valve 19, and the fourth exhaust valve 20 are respectively in communication with the exhaust passage 9. The intake passage 8 is for supplying air to the first, second, third and fourth intake valves 13, 14, 15 and 16, and the exhaust passage 9 is for providing a passage for gas discharge from the first, second, third and fourth exhaust valves 17, 18, 19 and 20.

In one embodiment, the first, second, third, and fourth intake valves 13, 14, 15, and 16 are disposed on the cylinder 1 at linear intervals parallel to the first direction, and the first, second, third, and fourth exhaust valves 17, 18, 19, and 20 are disposed on the cylinder 1 at linear intervals parallel to the first direction. More specifically, the first intake valve 13 is disposed opposite to the first exhaust valve 17, the second intake valve 14 is disposed opposite to the second exhaust valve 18, the third intake valve 15 is disposed opposite to the third exhaust valve 19, and the fourth intake valve 16 is disposed opposite to the fourth exhaust valve 20. The two-crankshaft tandem piston type four-stroke engine further includes a first camshaft mechanism 30 and a second camshaft mechanism 40 which are disposed opposite to each other outside the cylinder block 1, the first camshaft mechanism 30 being used for driving opening and closing of the first intake valve 13, the second intake valve 14, the third intake valve 15, and the fourth intake valve 16, and the second camshaft mechanism 40 being used for driving opening and closing of the first exhaust valve 17, the second exhaust valve 18, the third exhaust valve 19, and the fourth exhaust valve 20. Thus, the layout of the double-crankshaft serial piston type four-stroke engine can be more reasonable and compact.

For example, compared with a turboshaft engine, the double-crankshaft serial piston type four-stroke engine to be protected has the advantages of low cost, high efficiency, large speed regulation range, wide application range and the like, and is not only suitable for land-sea equipment needing power driving, such as vehicles, ships and the like, but also suitable for aircrafts, such as helicopters and the like.

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the invention.

Claims (10)

1. The double-crankshaft serial piston type four-stroke engine is characterized in that a unit basic structure comprises a cylinder body (1), a serial piston assembly (2) and a crankshaft connecting rod assembly (3); wherein,,

the cylinder (1) comprises a first cylinder section (11) and a second cylinder section (12) arranged along a first direction; the first cylinder section (11) is provided with a first intake valve (13), a second intake valve (14), a first exhaust valve (17), a second exhaust valve (18), a first fuel injection mechanism (201) and a second fuel injection mechanism (202), and the second cylinder section (12) is provided with a third intake valve (15), a fourth intake valve (16), a third exhaust valve (19), a fourth exhaust valve (20), a third fuel injection mechanism (203) and a fourth fuel injection mechanism (204);

the tandem piston assembly (2) comprises a central rod structure (23), a first piston (21) and a second piston (22); the first piston (21) is slidably arranged in the first cylinder section (11) along the first direction, the first cylinder section (11) is divided into a first chamber (111) and a second chamber (112), the first intake valve (13), the first exhaust valve (17) and a first fuel injection mechanism (201) are respectively communicated with the first chamber (111), and the second intake valve (14), the second exhaust valve (18) and a second fuel injection mechanism (202) are respectively communicated with the second chamber (112); the second piston (22) is arranged in the second cylinder section (12) in a sliding manner along the first direction, the second cylinder section (12) is divided into a third chamber (121) and a fourth chamber (122), and the third intake valve (15), the third exhaust valve (19) and a third fuel injection mechanism (203) are respectively communicated with the third chamber (121); -the fourth inlet valve (16), the fourth outlet valve (20) and a fourth fuel injection mechanism (204) are in communication with the fourth chamber (122), respectively; the first piston (21) is arranged at a first end of the central rod structure (23), the second piston (22) is arranged in the middle of the central rod structure (23), a second end of the central rod structure (23) extends out of the cylinder body (1), and the axis of the central rod structure (23), the central line of the first cylinder section (11) and the central line of the second cylinder section (12) are overlapped;

the crankshaft connecting rod assembly (3) comprises a first connecting rod (33), a second connecting rod (35), a first crankshaft (32) and a second crankshaft (34); the first end of the first connecting rod (33) is rotationally connected with the first crankshaft (32), the first end of the second connecting rod (35) is rotationally connected with the second crankshaft (34), and the second end of the first connecting rod (33) and the second end of the second connecting rod (35) are respectively rotationally connected with the second end of the central rod structure (23); the first crankshaft (32) and the second crankshaft (34) synchronously rotate and turn reversely, the first connecting rod (33) and the second connecting rod (35) are symmetrically arranged by taking the axis of the central rod structure (23) as a symmetrical axis, and the first crankshaft (32) and the second crankshaft (34) are symmetrically arranged by taking the axis of the central rod structure (23) as a symmetrical axis.

2. The double-crankshaft serial-connection piston four-stroke engine according to claim 1, wherein the crankshaft connecting rod assembly (3) further comprises a first gear (36) and a second gear (37) which are meshed with each other, the first gear (36) and the second gear (37) are symmetrically arranged with the axis of the central rod structure (23) as a symmetry axis, the first crankshaft (32) is fixedly connected with the first gear (36), and the second crankshaft (34) is fixedly connected with the second gear (37).

3. A double crankshaft tandem piston four-stroke engine according to claim 1, wherein the crankshaft connecting rod assembly (3) further comprises a connecting piece (24) connected to the second end of the central rod structure (23), the second end of the first connecting rod (33) and the second end of the second connecting rod (35) being in rotational connection with the connecting piece (24), respectively.

4. The double-crankshaft serial piston four-stroke engine according to claim 1, wherein the center rod structure (23) comprises a center rod (231) and an outer sleeve (232), the outer sleeve (232) is sleeved outside the center rod (231), and the first piston (21) and the second piston (22) are fixedly connected with the outer sleeve (232);

the center rod (231) is provided with a hollow structure (2312) for inputting lubricating oil, a first opening (2321) is formed in the outer sleeve (232), a lubricating channel (211) is formed in each of the first piston (21) and the second piston (22), the hollow structure (2312), the first opening (2321) and the lubricating channel (211) are sequentially communicated, and a second opening (212) communicated with the lubricating channel (211) is formed in each of the side wall of the first piston (21) in clearance fit with the first cylinder section (11) and the side wall of the second piston (22) in clearance fit with the second cylinder section (12).

5. The double-crankshaft tandem piston four-stroke engine according to claim 4, further comprising a lubrication oil connector (50) for inputting lubrication oil to the hollow structure (2312), the lubrication oil connector (50) being connected to an end of the central rod (231) protruding outside the cylinder (1).

6. The double-crankshaft tandem piston four-stroke engine according to any one of claims 1 to 5, wherein a first end cover (4), a second end cover (5) and a third end cover (6) are arranged in the cylinder block (1) at intervals along the first direction, the first end cover (4) and the second end cover (5) are respectively positioned at two ends of the first cylinder section (11), and the second end cover (5) and the third end cover (6) are positioned at two ends of the second cylinder section (12).

7. A double crankshaft series piston four-stroke engine according to claim 6, wherein a cooling and lubrication channel (51) is provided in the second end cap (5) running through in a second direction, which is perpendicular to the first direction.

8. A double-crankshaft series-piston four-stroke engine according to any of claims 1 to 5, wherein the cylinder block (1) comprises a cooling jacket (7), the first cylinder section (11) and the second cylinder section (12) being provided with cooling jackets (7), respectively.

9. A double-crankshaft series-piston four-stroke engine according to any one of claims 1 to 5, wherein an intake passage (8) and an exhaust passage (9) are further provided on the cylinder block (1), the first intake valve (13), the second intake valve (14), the third intake valve (15) and the fourth intake valve (16) are respectively communicated with the intake passage (8), and the first exhaust valve (17), the second exhaust valve (18), the third exhaust valve (19) and the fourth exhaust valve (20) are respectively communicated with the exhaust passage (9).

10. A double-crankshaft tandem piston four-stroke engine according to any one of claims 1 to 5, wherein the first intake valve (13), the second intake valve (14), the third intake valve (15) and the fourth intake valve (16) are arranged on the cylinder (1) at a linear interval parallel to the first direction; the first exhaust valve (17), the second exhaust valve (18), the third exhaust valve (19) and the fourth exhaust valve (20) are arranged on the cylinder body (1) at intervals along a straight line parallel to the first direction;

the double-crankshaft serial piston four-stroke engine further comprises a first camshaft mechanism (30) and a second camshaft mechanism (40) which are positioned outside the cylinder body (1) and are oppositely arranged;

the first camshaft mechanism (30) is used for driving the first intake valve (13), the second intake valve (14), the third intake valve (15) and the fourth intake valve (16) to open and close, and the second camshaft mechanism (40) is used for driving the first exhaust valve (17), the second exhaust valve (18), the third exhaust valve (19) and the fourth exhaust valve (20) to open and close.

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