TWI424118B - Engine cylinder head structure - Google Patents

Description

Engine cylinder head structure

The present invention relates to an engine cylinder head structure, and more particularly to an engine cylinder head structure suitable for a locomotive.

The purpose of the engine cooling system is to prevent the engine from overheating and damage, or to avoid work efficiency. The cooling system can be roughly classified into an air cooling system, an oil cooling system, a water cooling system, or a hybrid system in which the air cooling system flows around the engine to remove heat, and the oil cooling system is a lubricating oil cooler that first cools and lubricates. The oil is then circulated inside the engine by the lubricating oil to remove heat. The water cooling system uses water and coolant to flow in the water jacket of the engine to remove heat.

Refer to Figures 1~2. The conventional engine cylinder head mainly includes a cylinder head body 90 and a cam shaft seat 91. The cylinder head body 90 has four sides substantially divided into a ring, and the order is: a spark plug side 901, an exhaust side 902, a chain chamber side 903, and an intake side 904. The spark plug side 901 is recessed with an air inlet passage 906. The air inlet passage 906 extends deep into the chamber wall 96 of the chain chamber 908, and the opposite sides of the combustion chamber wall 95 of the cylinder head body 90 are respectively the combustion chamber 905 and the aforementioned inlet air flow. Road 906. A spark plug 94 is also inserted into the combustion chamber wall 95. The intake air passage 906 is in communication with one of the exhaust passages 907 located on the exhaust side.

The camshaft seat 91 is fixed to the cylinder head body 90 for supporting a camshaft 92, and one end of the camshaft 92 is coaxially sleeved with a sprocket 931. A chain 932 extends from the chain chamber 908 and is simultaneously hung on the sprocket 931 and a crankshaft (not shown) for transmitting crankshaft power to the camshaft 92.

The cooling air flow entering the air flow passage 906 first cools the spark plug 94, the outer surface of the combustion chamber wall 95, and then leads to the exhaust air passage 907, so that the temperature of the engine exhaust side 902 is also slightly lowered. However, in terms of the existing structural design, the airflow discharge area cannot be greatly increased due to the limitation of the distance and the thickness of the bolt locking holes 911, 912 and the thickness of the exhaust passage (not shown), so that it is difficult to improve the heat dissipation effect.

For such a conventional engine cylinder head, the cooling effect on the chain chamber side 903 is also neglected so that there is a potential risk of high temperature accumulation on the chain chamber side 903.

SUMMARY OF THE INVENTION A primary object of the present invention is to provide an engine cylinder head structure that enhances engine cooling under a limited head space.

To achieve the above object, the engine cylinder head structure of the present invention comprises a cylinder head body, a camshaft seat, a valve cam mechanism, a sprocket, a chain and a connecting pipe. The cylinder head body includes a spark plug side and a chain chamber side, the Mars plug side recess is provided with an open air inlet flow passage, and the chain chamber side defines a chain chamber. The camshaft seat is fixed to the cylinder head body.

The valve cam mechanism includes a cam shaft rotatably supported by the cam shaft seat. The sprocket is coaxially sleeved on the camshaft, and the chain is hung on the sprocket and extends in the chain chamber.

The communication pipe passes through the chain chamber from the air inlet passage, and includes a first opening and a second opening. The first opening communicates with the air flow passage, and the second opening communicates with the outer side of the cylinder head body.

With the above structural design, the cooling air flow passes from the air inlet passage on the spark plug side to the exhaust passage and the communication pipe, thereby taking into consideration both the cooling exhaust side and the chain chamber side. There is a substantial increase in the overall cooling effect of the engine.

The engine cylinder head structure may further include at least one sealing ring interposed between the communication pipe and the cylinder head body to prevent gas or lubricating oil in the engine from leaking to the external environment.

The cylinder head to which the present invention is applicable may be one-piece or separate. In the case of a one-piece cylinder head, the cylinder head body includes a side opening, the side opening is covered by a side cover, and the communication tube can be designed to be integrally formed with the side cover. The aforementioned side cover may include a labyrinth structure for assisting in the separation of blow-by gas.

The cylinder head body can be formed with a fin structure on the surface to enhance the heat dissipation effect. The valve cam mechanism may include a two-valve cam that is responsible for the steps of intake and exhaust respectively. The cylinder head body may be formed with a flow guiding structure on the surface, which is exposed to the inlet air flow passage, thereby guiding the wind flow on the spark plug side. The flow cross section of the connecting tube can be circular or other geometric shape.

Refer to Figures 3~6. The figure shows a cylinder head portion of a locomotive engine. The engine cylinder head mainly includes a cylinder head body 11 and a camshaft seat 12. The outer circumference of the cylinder head body 11 can be roughly divided into a spark plug side 111, an exhaust side 112, a chain chamber side 113, and an intake side 114. The cylinder head body 11 defines a combustion chamber 15 and a chain chamber 14. The engine cylinder head structure of the embodiment also needs to be combined with an upper cover (not shown) and the cylinder head body 11 to close the cylinder head body 11 on the top surface, and cover the valve cam mechanism 20, the chain and the like. , especially known as the split cylinder head.

The spark plug side 111 is recessed with an air inlet passage 13 which is open to the outside and extends inwardly to a side wall 141 of the chain chamber 14. Separated between the inlet air passage 13 and the combustion chamber 15 is a combustion chamber wall 151 which is connected to the chain chamber side wall 141. A spark plug 30 is fixed through the combustion chamber wall 151 and the end projects into the combustion chamber 15.

The exhaust side 112 is on one side of the port having the exhaust passage 116, the intake side 114 is on one side of the port having the intake port 115, and the chain chamber side 113 is on the side of the chain chamber 14. The cylinder head body 11 is formed with a fin structure 16 on the outer surface that helps the engine to dissipate heat. The intake passage 13 is in communication with the exhaust passage 17.

The cylinder head body 11 is further formed with a flow guiding structure 131 on the surface, and the flow guiding structure 131 is exposed to the air inlet flow passage 13 for smoothing the air flow and avoiding turbulence.

The camshaft base 12 is fixed to the cylinder head body 11 and has a substantially quadrangular shape as viewed from the top surface, and has four bolt locking holes 121 to 124 distributed at four corners. The camshaft seat 12 is for supporting a valve cam mechanism 20. In detail, the valve cam mechanism 20 includes a cam shaft 21 and two valve cams 22, 23 fixed to the cam shaft 21, and the cam shaft 21 is rotatably supported by the cam shaft seat 12 through the two bearings 27, 28. The two valve cams 22, 23 are used to push the corresponding rocker arm mechanism (not shown), thereby causing displacement of the intake valve and the exhaust valve (not shown).

A sprocket 24 is coaxially fixed to the camshaft 21, and a chain 25 is hung thereon. The chain 25 extends to the chain chamber 14 and is attached to a sprocket (not shown) on a crankshaft at the other end, thereby transmitting crankshaft power to the valve cam mechanism 20.

Specifically, the two ends of the connecting tube 26 have a first opening 261 and a second opening 262. The connecting tube 26 extends through the chain chamber 14 in a direction parallel to the X coordinate. The first opening 261 communicates with the air inlet passage 13 and the second opening. 262 is connected to the outer side of the cylinder head body 11. As can be seen from the figure, the direction in which the communicating pipe 26 and the chain chamber extend (parallel Z coordinates) is substantially vertical.

In a practical practice, a through hole 143, 144 may be formed in each of the two cavity walls 141, 142 constituting the chain chamber 14, and then the through hole 143, 144 is passed through the previously completed communication pipe 26, and finally the communication pipe 26 is locked to the cylinder head by the bolt 33. Body 11. Of course, the configuration of the communication tube 26 must be performed without interfering with the chain 25. For example, in the present embodiment, the communication tube 26 is located within the outline of the chain, thereby saving space.

In order to prevent the gas or lubricating oil in the inner chamber of the engine from leaking from the imperfect fit between the communication tube 26 and the cylinder head body 11 to the external environment, a sealing ring 31, 32 may be looped on both ends of the communicating tube 26 to seal The rings 31, 32 are disposed between the communication tube 26 and the cylinder head body 11.

As can be seen from the above, when the external air flow flows in the direction of the parallel X coordinate from the intake air flow passage 13 on the spark plug side, a part flows to the exhaust air flow path 17 (parallel Y coordinate), and the other part flows to the communication pipe 26, Therefore, not only the exhaust side 112 can obtain an appropriate cooling effect, but also the chain chamber side 113 can also have the effect of lowering the temperature, so that the overall heat dissipation effect of the engine is better, thereby improving the engine performance.

Although the flow cross section of the communication pipe 26 in the above embodiment is circular, it is of course not limited thereto, and may be other various shapes such as an ellipse, a square, a rectangle or other polygons.

Referring to Figures 7 and 8, there is shown a plan view of a cylinder head of the second preferred embodiment and a cross-sectional view thereof. In the present embodiment, the engine cylinder head structure is an integral cylinder head, and the cylinder head body 50 has a side opening 501 as an operating opening for assembling and repairing the valve cam mechanism 52 or the chain transmission component. Therefore, it is not necessary to assemble the upper cover on the top surface of the cylinder head body 50, but it is necessary to cover the side opening 501 from the side of the cylinder head body 50 with the one side cover 51. In particular, the side cover 51 is integrally formed with the communication tube 53. It can be seen that the cylinder head structure of the present invention is suitable for an integrated cylinder head and a split cylinder head. In this example, the inward surface of the side cover 51 assembled to the cylinder head body 50 includes a labyrinth structure 511 for enhancing the oil and gas separation effect of the blow-by gas.

The above-mentioned embodiments are merely examples for convenience of description, and the scope of the claims is intended to be limited to the above embodiments.

90. . . Cylinder head body

901. . . Mars plug side

902. . . Exhaust side

903. . . Chain side

904. . . Intake side

905. . . Combustion chamber

906. . . Air inlet

907. . . Exhaust flow channel

908. . . Chain room

91. . . Camshaft seat

911,912. . . Bolt lock with hole

92. . . Camshaft

931. . . Sprocket

932. . . Chain

94. . . Mars plug

95. . . Combustion chamber wall

96. . . Cavity wall

11,50. . . Cylinder head body

111. . . Mars plug side

112. . . Exhaust side

113. . . Chain side

114. . . Intake side

115. . . Intake

116. . . Exhaust passage

12. . . Camshaft seat

121,122,123,124. . . Bolt lock with hole

13. . . Air inlet

131. . . Diversion structure

14. . . Chain room

141,142. . . Cavity wall

143,144. . . perforation

15. . . Combustion chamber

151. . . Combustion chamber wall

16. . . Fin structure

17. . . Exhaust flow channel

20,52. . . Valve cam mechanism

twenty one. . . Camshaft

22,23. . . Valve cam

twenty four. . . Sprocket

25. . . Chain

26,53. . . Connecting pipe

261. . . First opening

262. . . Second opening

27,28. . . Bearing

30. . . Mars plug

31,32. . . Sealing ring

33. . . bolt

501. . . Side opening

51. . . Side cover

511. . . Labyrinth structure

Figure 1 is a cross-sectional view of a conventional engine cylinder head.

Figure 2 is a cross-sectional view of the engine cylinder head taken along line II-II of Figure 1.

Figure 3 is a top plan view of a cylinder head in accordance with a first preferred embodiment of the present invention.

Figure 4 is a cross-sectional view of the engine cylinder head taken along line IV-IV of Figure 3.

Figure 5 is a cross-sectional view of the engine cylinder head taken along line V-V of Figure 4.

Figure 6 is a cross-sectional view of the engine cylinder head taken along line VI-VI of Figure 4.

Figure 7 is a plan view of a cylinder head in accordance with a second preferred embodiment of the present invention.

Figure 8 is a cross-sectional view of the engine cylinder head taken along line VIII-VIII of Figure 7.

11. . . Cylinder head body

12. . . Camshaft seat

13. . . Air inlet

14. . . Chain room

141,142. . . Cavity wall

143,144. . . perforation

15. . . Combustion chamber

151. . . Combustion chamber wall

16. . . Fin structure

20. . . Valve cam mechanism

twenty one. . . Camshaft

22,23. . . Valve cam

twenty four. . . Sprocket

26. . . Connecting pipe

261. . . First opening

262. . . Second opening

27,28. . . Bearing

30. . . Mars plug

31,32. . . Sealing ring

Claims (8)

An engine cylinder head structure includes: a cylinder head body including a spark plug side and a chain chamber side, the Mars plug side recess is provided with an open air inlet flow passage, the chain chamber side defines a chain chamber; and a cam a shaft seat fixed to the cylinder head body; a valve cam mechanism comprising a cam shaft rotatably supported on the cam shaft seat; a sprocket coaxially sleeved on the cam shaft; a chain attached to the camshaft a sprocket extending in the chain chamber; and a communication tube passing through the chain chamber from the air inlet passage, including a first opening and a second opening, the first opening communicating with the air inlet passage The second opening is communicated to the outer side of the cylinder head body. The engine cylinder head structure according to claim 1, further comprising at least one sealing ring sandwiched between the communication pipe and the cylinder head body. The cylinder head structure of the engine of claim 1, wherein the cylinder head body further comprises a side opening, the side opening is covered by a side cover, and the connecting tube and the side cover are integrally formed . The engine cylinder head structure of claim 3, wherein the side cover comprises a labyrinth structure. The engine cylinder head structure of claim 1, wherein the cylinder head body has a fin structure formed on the surface. The engine cylinder head structure of claim 1, wherein the valve cam mechanism comprises a two-valve cam. The engine cylinder head structure according to claim 1, wherein the cylinder head body is formed with a flow guiding structure on the surface and exposed to the air inlet flow path. The engine cylinder head structure according to claim 1, wherein the communication pipe has a circular cross section.