TWI385301B - Cooling structure for horizontal engine - Google Patents

Description

Horizontal engine cooling structure

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a cooling structure for a horizontal engine, and more particularly to a cooling structure for a horizontal engine that uses a cooling passage to divert lubricating oil through a connecting wall between a piston chamber and a drive chamber to cool an engine temperature.

The existing four-stroke engine generates high temperatures in the cylinder head and the cylinder block due to the high-speed reciprocating action of the piston. In order to dissipate the high temperature to reduce the deformation of the thermal stress, the existing four-stroke engine will protrude a lot of fins on the cylinder head and the outside of the cylinder block to disperse the high temperature through the air cooling method. In addition, the conventional engine still has : Design of recirculating lubricating oil (also known as oil) along the inner wall surface of the chain chamber in the chain room of the engine.

Referring to FIG. 1, a side cross-sectional view of a conventional vertical engine configuration includes a cylinder head 81, a cylinder block 82, and a crankcase 90 disposed below the cylinder block 82. The cylinder head 81 is provided with a set of intake and exhaust passages (not shown) and a set of intake and exhaust valves (not shown), and a set of camshafts 83 for driving the intake and exhaust valves. The cylinder block 82 is provided with a piston chamber (not shown) for reciprocating a piston 84. The crankcase 90 is provided with a crankshaft 91 and a connecting rod 85 for connecting the crankshaft 91 and the piston 84. One side of the cylinder head 81 and the cylinder block 82 is provided with a chain chamber 86 that can communicate with the cylinder head 81, the cylinder block 82 and the crankcase 90. The chain chamber 86 is provided with a chain 87, and the chain 87 is connected to the crankcase. One of the crankshafts 91 in the drive 91 drives a sprocket 911 and a timing sprocket 831 on the camshaft 83 in the cylinder head 81 to transmit the power of the crankshaft 91 in the crankcase 90 to the cam of the cylinder head 81. Axis 83 drives the intake and exhaust valves.

The vertical engine structure is firstly sprayed to the cylinder head 81 by a pump-pressurized oil pipe (not shown) in the crankcase 90 to be sprayed on the timing sprocket of the camshaft 83. Lubrication is performed on the 831 and the valve mechanism (not shown), and then the lubricating oil flows back down the peripheral wall of the chain chamber 86 into the crankcase 90.

However, the above-mentioned conventional vertical engine construction still has the following problems in practical use. For example, a plurality of heat dissipation fins are protruded from the cylinder head and the cylinder block of the existing engine to disperse the high temperature of the engine through air cooling. However, since the connecting wall surface of the piston chamber (not shown) and the chain chamber 86 is separated from the outermost portion of the engine by the chain chamber 86, it is not possible to dissipate heat by external heat radiating fins, so that it is easy to make the piston chamber The temperature distribution is uneven and causes local thermal stress concentration and the risk of deformation and cracking, and affects engine performance and durability.

Furthermore, there is another conventional horizontal engine in which the conventional horizontal engine is substantially identical in structure to the vertical engine described above, and the main difference is that the cylinder of the horizontal engine is placed in a horizontal direction closer to the horizon. The direction of the engine cylinders is approximately horizontal, so that the lubricating oil is almost always flowed obliquely downward from the cylinder head directly along the inner wall of the lower position of the chain chamber to the crankcase. Moreover, the uneven distribution of the heat source of the horizontal engine piston chamber connecting wall and the influence of engine performance and durability are the same as those of the conventional vertical engine.

Therefore, it is necessary to provide a cooling structure for a horizontal engine to solve the problems of the prior art.

The main object of the present invention is to provide a horizontal engine cooling structure which is provided by temporarily arranging a first oil storage tank in a cylinder head for temporarily storing lubricating oil, and is disposed in a connecting wall between the piston chamber and the driving chamber. The first set of cooling passages directs the lubricating oil in the first oil storage tank obliquely downward into the crankcase to reduce the high temperature generated inside the piston chamber by cooling the connecting wall, thereby improving engine running efficiency and durability.

A secondary object of the present invention is to provide a horizontal engine cooling structure in which a distribution groove is formed between a drainage passage of a cylinder head and a plurality of section passages of a cylinder block, and the shape thereof is an inverted cone having an upper width and a narrow shape. More lubricating oil is drained to the section channel near the central position of the connecting wall to take away more heat sources in the central position, thereby increasing the cooling effect.

To achieve the above object, the present invention provides a horizontal engine cooling structure that is disposed within a horizontal engine that includes a cylinder head and a cylinder block, and one side of the cylinder head and the cylinder block a driving chamber is connected to a crankcase, the cooling structure includes a first oil storage tank and a first group of cooling passages, wherein the first oil storage tank is disposed in the cylinder head for temporarily storing lubricating oil, the first group The cooling passage is disposed in a connecting wall between the piston chamber and the driving chamber for draining the lubricating oil in the first oil storage tank obliquely downward to the crankcase.

In an embodiment of the invention, the first oil storage tank is formed by a common surrounding of the upper half of the two cam bearing seats in the cylinder head and a first surrounding wall.

In an embodiment of the present invention, the first group of cooling passages includes: a first drain passage first drain passage disposed in the first connecting wall of the cylinder head; and a first interval passage disposed in the cylinder The second connecting wall of the block is correspondingly connected to the first draining channel.

In an embodiment of the present invention, a distribution slot is disposed between the first drainage channel and the first interval channel, and the number of the first interval channels is plural.

In an embodiment of the invention, the distribution groove is disposed on the second connecting wall of the cylinder block.

In an embodiment of the invention, the distribution groove is disposed on the first connecting wall of the cylinder head.

In an embodiment of the invention, the distribution groove is formed in a shape that is wide and narrow.

In an embodiment of the invention, the distribution groove is formed in an inverted cone shape.

In an embodiment of the present invention, the cooling structure further includes: a second oil storage tank surrounded by the main body of the two cam bearing seats in the cylinder head, the first surrounding wall and a second surrounding wall And formed under the first oil storage tank.

In an embodiment of the present invention, the second oil storage tank is connected to a second group of cooling passages, and the second group of cooling passages includes: a second draining passage disposed in the first connecting wall of the cylinder head and located Below the first drainage channel, the second drainage channel is correspondingly connected to the second oil storage groove; and a second interval channel is disposed in the second connection wall of the cylinder block and below the first interval channel, and The second interval channel is correspondingly connected to the second drainage channel.

In an embodiment of the invention, the interval passages of the first group and the second group of cooling passages are formed within a second connecting wall covered by an outer diameter of a cylinder liner of the outer circumference of the piston.

In an embodiment of the invention, the horizontal axis of the horizontal engine is at an angle to the horizon, the angle being between 5 and 45 degrees.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

The following description is by way of illustration of the accompanying drawings, The directional terms mentioned in the present invention, such as "upper", "lower", "before", "after", "inside", "outside", "left", "right", etc., are only referred to as additional schemas. direction. Therefore, the directional terms used in the following embodiments of the present invention are merely used to assist in explaining the technical content of the present invention, and are not intended to limit the present invention.

Referring to FIG. 2, a front cross-sectional view showing a cooling structure of a horizontal engine according to a preferred embodiment of the present invention, wherein an engine cooling structure is disposed within a horizontal engine, and the horizontal engine is usually four strokes. The engine includes a cylinder head 11 , a cylinder block 12 , and a crankcase 20 . The cylinder head 11 is disposed obliquely above the cylinder block 12 , and the crankcase 20 is disposed obliquely below the cylinder block 12 . The cylinder head 11 is provided with a set of intake and exhaust passages (not shown), a set of inlet and exhaust valves (not shown) disposed on the intake and exhaust passages, and a set of valve drive members 13; the cylinder block 12 is provided There is a piston chamber 121 (not shown) which allows a piston (not shown) to reciprocate, and the piston chamber 121 is connected to a small piston chamber section of the cylinder head 11, so that the piston chamber 121 referred to hereinafter is also broad. A piston chamber section of the cylinder head 11 is included. The above-mentioned intake and exhaust passages, intake and exhaust valves and pistons are prior art and therefore will not be described in detail herein.

Referring to FIG. 2 again, the crankcase 20 is provided with a crankshaft 21 and a connecting rod (not shown) connecting the crankshaft 21 and the piston. The cylinder head 11 and the cylinder block 1 are internally provided. A drive chamber 14 (shown in Figures 3, 4B, and 5A) is connected to the cylinder head 11, the cylinder block 12, and the crankcase 20. The drive chamber 14 is provided with a driving component (not shown). The inner crankshaft 21 actuates the valve drive member 13 of the cylinder head 11 by the drive member 30, wherein the drive member 30 can be selected from a chain, a tappet or a gear according to engine specifications, and the crankshaft 21 and the valve drive member 13 corresponds to different types of drive elements 30 and has different configurations. For example, in the embodiment in which the driving member 30 is a chain, the power of the crankshaft 21 drives a sprocket (not shown) via one of the crankshafts 21, and the chain transmits power to a camshaft in the cylinder head 11. The timing sprocket (not shown) on the (not shown) allows the cam to directly abut the valve valve (not shown) or through the rocker arm (not shown) to control the opening and closing of the valve. In the embodiment, the cam or rocker arm is the so-called valve drive member 13; or, in another embodiment in which the drive member 30 is a tappet, the power of the crankshaft 21 passes through a crankshaft cam (not shown) on the crankshaft 21. The rocker arm (not shown) is abutted against the tappet, and the tappet transmits power to an upper rocker arm (not shown) in the cylinder head 11 to abut the valve to control the opening and closing of the valve. In this embodiment the upper rocker arm is the so-called valve drive member 13.

In addition, in the normal use state of the locomotive or the automobile, the cylinder axis of the horizontal engine of the embodiment is provided with an angle with the horizon, and the angle is between 5 degrees and 45 degrees, so it is called a horizontal engine. Furthermore, a piston wall section (not shown) of the cylinder head 11 and the drive chamber 14 have a first connecting wall A, and a piston chamber 121 of the cylinder block 12 and the driving chamber 14 also have a The second connecting wall B. The two connecting walls A, B refer to a wall portion which is located between the piston chamber 121 and the driving chamber 14 in a longitudinal direction in a longitudinal side cross-sectional view (as shown in FIGS. 2, 4B and 5A), and thus the connection referred to herein. The wall system includes the first connecting wall A and the second connecting wall B.

Referring to Figures 2 and 3, FIG. 3 is a perspective and partial cross-sectional view of the cylinder head 11 of the preferred embodiment of the present invention. As shown in Figures 2 and 3, the cooling structure of the present invention includes a first oil reservoir 15a and a second oil reservoir 15b. The first oil reservoir 15a is formed by two cam housings 111 in the cylinder head 11. The second portion and a first surrounding wall 112a are collectively surrounded; the second oil reservoir 15b is formed by the main body of the two cam bearing housings 111 in the cylinder head 11, the first surrounding wall 112a and a second surrounding wall. The 112b is collectively surrounded and located below the first oil reservoir 15a. The first oil storage tank 15a and the second oil storage tank 15b are disposed in the cylinder head 11 for temporarily accumulating lubricating oil (not shown) which is returned after lubricating the valve driving member 13; A set of cooling passages 161 and a second set of cooling passages 162 correspond to the first oil storage tank 15a and the second oil storage tank 15b, respectively. The first group of cooling passages 161 are disposed in the connecting walls A and B between the piston chamber 121 and the driving chamber 14. The first group of cooling passages 161 are used to obliquely lower the lubricating oil in the oil reservoir 15 Drain into the crankcase 20. In addition, a distribution slot 17 may be disposed in the middle of the first set of cooling passages 161. The function of the distribution slot 17 is described in detail below.

As shown in FIG. 2, in the embodiment, the first group of cooling passages 161 includes: a first drainage channel 16a and a first interval channel 16b, which are correspondingly connected to the first oil reservoir 15a; the second The group cooling passage 162 includes a second draining passage 16c and a second interval passage 16d corresponding to the second oil storage tank 15b. The first set of cooling passages 161 are located above the second set of cooling passages 162. The first drain passage 16a is provided at an upper end of the first connecting wall A of the cylinder head 11. The first section passage 16b is disposed in the second connecting wall B of the cylinder block 12 and is correspondingly connected to the first draining passage 16a. The second drain channel 16c is disposed at a lower end of the first connecting wall A of the cylinder head 11 (ie, below the first draining passage 16a), and is correspondingly connected to the second oil storage tank 15b. The second section channel 16d is disposed in the second connecting wall B of the cylinder block 12 and below the first section channel 16b, and the second section channel 16d is correspondingly connected to the second draining channel 16c.

Referring to Figures 3, 4A, 4B and 4C again, wherein FIG. 4A is a top cross-sectional view of the oil sump 15a, 15b of the cylinder head 11 of the preferred embodiment of the present invention; FIG. 4B is a preferred embodiment of the present invention. For example, a cross-sectional view of the first oil reservoir 15a of the cylinder head 11 taken along line 4B-4B of FIG. 4A; FIG. 4C is a view of the cylinder head 11 of the preferred embodiment of the present invention taken along line 4C-4C of FIG. 4A. A left side cross-sectional view of the oil sump 15a, 15b. As shown in the figure, the first oil reservoir 15a is formed by the upper half of the two cam bearing housings 111 in the cylinder head 11 and the first surrounding wall 112a; the second oil reservoir 15b is composed of the cylinder The main body of the two cam bearing housings 111 in the head 11, the first surrounding wall 112a and the second surrounding wall 112b are collectively surrounded and located below the first oil reservoir 15a. The cam bearing housing 111, hereinafter referred to as a general term, refers to a combination of a camshaft bearing and a bearing housing of the valve driving member 13. The first oil reservoir 15a and the second oil reservoir 15b disclosed in the preferred embodiment of the present invention are storage spaces formed by the cam bearing housing 111 and the first surrounding wall 112a and the second surrounding wall 112b. However, the invention is not limited thereto. The first oil reservoir 15a and the second oil reservoir 15b may be formed by other members to receive the lubricating oil that is sprayed on the valve driving member 13 for lubrication.

5A and 5B, FIG. 5A is a left side view of the cylinder block 12 of the preferred embodiment of the present invention; FIG. 5B is a cylinder of the preferred embodiment of the present invention taken along line 5B-5B of FIG. 5A. An arc-shaped cross-sectional view of the block 12 (a cross-sectional view of Fig. 5A). As shown in FIGS. 5A and 5B, a distribution slot 17 is disposed between the first drainage channel 16a of the cylinder block 12 and the first section channel 16b, and the number of the first section channels 16b is plural, so as to be efficient. The lubricating oil in the first oil storage tank 15a is drained obliquely downward into the crankcase 20. In the preferred embodiment of the present invention, the distribution slot 17 is preferably disposed on the second connecting wall B of the cylinder block 12, and the number of the first interval channels 16b is four, but the invention is not limited thereto. . The distribution groove 17 can also be disposed at other positions, for example, on the first connecting wall A of the cylinder head 11; the number of the first interval channels 16b can also be other numbers, for example, 2 or 3 or the like.

More specifically, the distribution groove 17 is preferably formed in an inverted cone shape which is wide and narrow, and flows out of the lowest point of the distribution groove 17 by gravity after the lubricating oil flows out of the first drainage channel 16a of the cylinder head 11, thereby The first section passage 16b (ie, the lowermost one) of the cylinder block 12 farthest from the opening of the first drain passage 16a can be preferentially distributed to the lubricating oil, and the inverted tapered distribution groove 17 can achieve an even distribution of lubricating oil. The effect of the plurality of first section passages 16b, and due to the inverted cone-shaped design, the lowest first section passage 16b is not capable of obtaining the most lubricating oil, but the one or two first section passages 16b of the central position may The most lubricating oil is obtained, because in the actual engine operation, the portion of the cylinder block 12 at the central position of the second connecting wall B is thinner and closest to the piston chamber 121, so more lubricating oil flows through the central position. The first section of the passage 16b can take more temperature to increase the cooling effect.

Referring to Figure 6, there is shown a front partial cross-sectional view of a cooling structure of a horizontal engine in accordance with a preferred embodiment of the present invention. As shown in FIG. 6, in the preferred embodiment of the present invention, the first interval channel 16b and the second interval channel 16d form a second connection that can be covered by the outer diameter of a cylinder liner 123 at the periphery of the piston chamber 121. Wall B range (span D). The first section channel 16b and the second section channel 16d are also located substantially between the two coupling holes 122 of the cylinder block 12.

As shown in FIG. 6, when the engine is started, the lubricating oil pumped by the pumping cylinder (not shown) in the crankcase 20 is first introduced into the cylinder head 11 and the lubricating oil is sprayed on the valve. The first oil reservoir 15a and the second oil reservoir 15b are also partially lubricated with the lubricating oil used for the valve driving member 13, or the first oil reservoir 15a and the second oil reservoir 15b are also The lubricating oil for cooling which is pumped by the crankcase 20 is directly housed. The first oil reservoir 15a and the second oil reservoir 15b pass through the first and second sets of cooling passages 161, 162, and pass through the first connecting wall A of the cylinder head 11 and the second connection of the cylinder block 12. Wall B then flows into the crankcase 20 (not shown). Therefore, the first and second sets of cooling passages 161, 162 can take away the temperature generated by the piston chamber 121 and lower the operating temperature of the piston chamber 121. On the other hand, the present invention may also selectively install a lubricating oil cooler (not shown) from the outside of the engine to make it easier to dissipate the temperature, so as to maintain the quality of the lubricating oil from being deteriorated due to high heat, thereby avoiding the engine. Damage to the operation of the piece will increase engine durability and performance.

Although, in a preferred embodiment of the invention, the cooling configuration reveals a system comprising two separate cooling configurations: the first set of cooling configurations is the first set of sump 15a and the corresponding set of first cooling passages 161 (including the first drainage channel 16a, the distribution groove 17 and the plurality of first interval channels 16b); and the second group of cooling structures is the second oil storage groove 15b and the corresponding second set of cooling passages 162 ( The second drain channel 16a and the second interval channel 16b) are included. However, in the effect of the actual use, the first oil storage tank 15a and its corresponding first set of cooling passages 161 are located, because the first oil storage tank 15a is at a higher position, and the distribution tank 17 is lubricating oil. It is distributed to a plurality of first section passages 16b, thus providing a primary cylinder cooling effect. In addition, since the second oil storage tank 15b and the corresponding second cooling passage 162 mechanism are disposed at a lower position, the lubricating oil cannot flow through the hot connecting walls A and B of the cylinder head 11 and the cylinder block 12. The central position has a relatively small effect and only has the function of auxiliary cooling. Therefore, in another embodiment of the present invention, the cooling structure only needs to provide the first group of cooling passages 161 corresponding to the first oil storage tank 15a (including the first drainage channel 16a, the distribution slot 17 and a plurality of The first interval channel 16b) can achieve the desired cooling effect.

As described above, the connection wall surface at the center of the cylinder of the cooling structure of the conventional horizontal engine cannot be cooled by the lubricating oil, so that the heat source of the cylinder is unevenly distributed, thereby causing thermal stress concentration and the risk of deformation and cracking, so that the engine Durability and performance will be affected. The cooling structure of the horizontal engine of the present invention is provided by the first oil sump 15a in the cylinder head 11 for temporarily accumulating lubricating oil, and the connecting walls A and B between the piston chamber 121 and the driving chamber 14 The first group of cooling passages 161 are disposed to drain the lubricating oil in the first oil storage tank 15a downward into the crankcase 20 to reduce the internal generation of the piston chamber 121 by cooling the connecting walls A, B. High temperatures, which in turn improve engine performance and durability.

The present invention has been disclosed in its preferred embodiments, and is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

11‧‧‧Cylinder head

111‧‧‧Cam bearing housing

112a‧‧‧First surrounding wall

112b‧‧‧Second surrounding wall

113‧‧‧Combination hole

12‧‧‧Cylinder block

121‧‧‧Piston room

122‧‧‧bond hole

13‧‧‧Valve drive components

14‧‧‧Drive room

15a‧‧‧First oil storage tank

15b‧‧‧Second oil storage tank

161‧‧‧First set of cooling paths

162‧‧‧Second group of cooling pathways

16a‧‧‧First drainage channel

16b‧‧‧First interval channel

16c‧‧‧Second drain

16d‧‧‧Second interval channel

17‧‧‧Distribution slot

20‧‧‧ crankcase

21‧‧‧ crankshaft

81‧‧‧Cylinder head

82‧‧‧Cylinder block

83‧‧‧ camshaft

831‧‧‧ timing sprocket

84‧‧‧Piston

85‧‧‧ linkage

86‧‧‧Chain room

87‧‧‧Chain

90‧‧‧ crankcase

91‧‧‧ crankshaft

911‧‧‧ drive sprocket

A‧‧‧first connecting wall

B‧‧‧Second connection wall

D‧‧‧Span

Figure 1: Side cross-sectional view of a cooling structure for a conventional vertical engine.

Figure 2 is a front cross-sectional view showing the cooling structure of the horizontal engine of the preferred embodiment of the present invention.

Figure 3 is a perspective and partial cross-sectional view of a cylinder head in accordance with a preferred embodiment of the present invention.

Figure 4A is a top cross-sectional view of the oil sump of the cylinder head of the preferred embodiment of the present invention.

Figure 4B is a front cross-sectional view of the first oil reservoir of the cylinder head taken along line 4B-4B of Figure 4A in accordance with a preferred embodiment of the present invention.

Figure 4C is a left side cross-sectional view of the oil sump of the cylinder head taken along line 4C-4C of Figure 4A in accordance with a preferred embodiment of the present invention.

Figure 5A is a left side view of the cylinder block of the preferred embodiment of the present invention.

Figure 5B is an arcuate cross-sectional view of the cylinder block taken along line 5B-5B of Figure 5A in accordance with a preferred embodiment of the present invention.

Figure 6 is a front partial cross-sectional view showing the cooling structure of the horizontal engine of the preferred embodiment of the present invention.

11. . . Cylinder head

111. . . Cam bearing housing

113. . . Bonding hole

12. . . Cylinder block

122. . . Bonding hole

13. . . Valve drive member

161. . . First set of cooling passages

162. . . Second set of cooling paths

16a. . . First drain

16b. . . First interval channel

16c. . . Second drain

16d. . . Second interval channel

17. . . Distribution slot

20. . . Crankcase

twenty one. . . Crankshaft

A. . . First connecting wall

B. . . Second connecting wall

Claims (12)

A horizontal engine cooling structure is disposed in a horizontal engine, the horizontal engine includes a cylinder block, a cylinder head disposed obliquely above the cylinder block, and a crankshaft disposed obliquely below the cylinder block a cylinder chamber having a piston chamber for allowing a piston to reciprocate; and a drive chamber connected to the crankcase on one side of the cylinder head and the cylinder block, the drive chamber being provided with a driving component Actuating the valve drive member of the cylinder head by the drive member in the crankcase, wherein the cooling structure comprises: a first oil storage tank disposed in the cylinder head for temporarily accumulating from the cylinder head a lubricating oil pumped by the crankcase; and a first set of cooling passages disposed in a connecting wall between the piston chamber and the driving chamber, the first set of cooling passages for the first oil storage tank Lubricating oil is drained obliquely downward to the crankcase, the first set of cooling passages includes: a first drain passage disposed in the first connecting wall of the cylinder head; and a first interval passage disposed in the cylinder block In the second connecting wall, and The drainage channel communicates with the first, wherein the drainage channel is provided between the first section and the first passageway a distribution groove, wider at the grooves formed in the shape of the distribution, the number of the first section of the plurality of channels. The horizontal engine cooling structure according to claim 1, wherein the first oil storage tank is formed by a common surrounding of the upper half of the two cam bearing seats in the cylinder head and a first surrounding wall. The cooling structure of the horizontal engine as described in claim 1 The distribution groove is disposed on the second connecting wall of the cylinder block. The horizontal engine cooling structure according to claim 1, wherein the distribution groove is disposed on the first connecting wall of the cylinder head. The horizontal engine cooling structure according to claim 1, wherein the distribution groove is formed in an inverted cone shape. The horizontal engine cooling structure according to claim 2, further comprising a second oil storage tank temporarily accumulating lubricating oil pumped from the crankcase, the two cam bearings in the cylinder head The main body of the seat, the first surrounding wall and a second surrounding wall are jointly surrounded and located below the first oil storage groove. The horizontal engine cooling structure according to claim 6, wherein the second oil storage tank is connected to a second group of cooling passages, and the second group of cooling passages comprises: a second drain passage disposed at the cylinder The first connecting wall of the head is located below the first draining channel, and the second draining channel is correspondingly connected to the second oil storage tank; and a second interval channel is disposed in the second connecting wall of the cylinder block and Located below the first interval channel, and the second interval channel is corresponding to the second drainage channel. The horizontal engine cooling structure according to claim 7, wherein the interval passages of the first group and the second group of cooling passages form a second connection covered by an outer diameter of a cylinder liner of the outer circumference of the piston Within the wall. The cooling structure of the horizontal engine as described in claim 1 The cylinder axis of the horizontal engine is at an angle to the horizon, and the angle is between 5 and 45 degrees. The horizontal engine cooling structure according to claim 1, wherein the driving element is a chain, and the valve driving member is a cam. The horizontal engine cooling structure of claim 10, wherein the valve drive member further comprises a rocker arm. The horizontal engine cooling structure according to claim 1, wherein the driving element is a tappet, and the valve driving member is an upper rocker arm.