Methanol in-cylinder direct injection marine engine cylinder head
By designing injector holes and intake valve holes in the cylinder head of the marine engine, combined with glow plug devices and cooling water channels, the problems of poor methanol fuel atomization and insufficient cylinder head space were solved, realizing direct methanol injection and ignition in the cylinder, and ensuring stable engine operation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZICHAI POWER CO LTD
- Filing Date
- 2025-07-05
- Publication Date
- 2026-06-23
AI Technical Summary
In traditional small- and medium-bore methanol engines for marine use, the methanol fuel supply method leads to poor fuel atomization, affecting the formation of the in-cylinder mixture. Furthermore, the cylinder head space is insufficient to simultaneously accommodate the ignition source and the methanol injector, affecting the engine's stable operation.
Design a methanol direct injection marine engine cylinder head, by setting an injector hole in the middle of the cylinder head and cooperating with a methanol injector, setting an intake valve hole in the circumference, and arranging a glow plug device in one of the intake valve holes, combined with cooling water channel for cooling, to achieve direct injection and ignition of methanol fuel.
It achieves effective atomization of methanol fuel and formation of in-cylinder mixture, ensuring stable engine operation, while not requiring changes to the existing cylinder head structure, thus guaranteeing the stability and reliability of the cylinder head.
Smart Images
Figure CN224396589U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of marine engine cylinder head technology, specifically disclosing a methanol direct injection marine engine cylinder head. Background Technology
[0002] In traditional marine small- and medium-bore methanol engines, methanol fuel is generally supplied through external injection methods such as intake manifold injection and intake manifold premixing. This limits the starting pressure of the methanol injector, resulting in poor methanol fuel atomization, which is not conducive to the formation of in-cylinder mixture. In addition, some fuel flows into the cylinder in liquid form at the intake valve after hitting the wall or re-liquefies in the cylinder, causing piston erosion, cylinder liner scoring, and lubricating oil emulsification, which seriously affects the stable operation of the methanol engine.
[0003] Developing direct injection technology is the best solution to the above problems. However, the limited space in the cylinder head of small- and medium-bore marine engines makes it difficult to simultaneously arrange the ignition source and methanol injector. In other words, the space on the combustion surface of the cylinder head is insufficient to support the simultaneous arrangement of glow plugs and methanol injectors, which has become the main challenge in developing methanol direct injection. Utility Model Content
[0004] In view of the shortcomings of the prior art, this utility model provides a cylinder head for a methanol direct injection marine engine to solve the problems that methanol injection outside the cylinder can easily lead to poor methanol combustion and even affect the stable operation of the engine; and the limited cylinder head space of small and medium diameter marine engines makes it difficult to arrange an ignition source and a methanol injector at the same time.
[0005] The technical solution adopted by this utility model to solve its technical problem is:
[0006] The methanol direct injection marine engine cylinder head includes a cylinder head with an injector hole through the center of the cylinder head. A methanol injector is installed inside the injector hole. Several intake valve holes are evenly spaced along the circumference on the outer side of the injector hole. Both the injector hole and the intake valve holes are cylindrical in shape. A glow plug is installed inside one of the intake valve holes. Several cooling water channels are connected to the bottom of the injector hole and several intake valve holes. Several cooling water channels are located between two adjacent intake valve holes. The ends of several cooling water channels away from the injector hole are connected to a cooling water chamber.
[0007] Furthermore, there are four intake valve holes and four cooling water channels.
[0008] Furthermore, an air inlet is provided on one side of the cylinder head, and a tangential air inlet and a spiral air inlet are provided inside the cylinder head. One end of the tangential air inlet is connected to the air inlet, and the other end of the tangential air inlet is connected to two of the air inlet valve holes, including an air inlet valve hole with an internal glow plug device. The spiral air inlet is connected to the other two air inlet valve holes.
[0009] Furthermore, the glow plug device includes a glow plug, a sheath, and a water seal seat. The water seal seat is interference-fitted to the bottom of the intake valve hole and is fitted onto the bottom of the sheath. The sheath is fitted onto the lower part of the glow plug, and the sheath is threadedly connected to the inner wall of the intake valve hole. The glow plug passes through the sheath and the water seal seat and extends into the cylinder.
[0010] Furthermore, the glow plug includes a hot-head coil located at the bottom, which extends into the cylinder.
[0011] Furthermore, the bottom of the inner side of the sheath is provided with several ribs for assisting in the positioning of the glow plug, which are evenly spaced along the circumference.
[0012] Furthermore, a water cavity is provided on the outer side of the water seal seat, and a sleeve is provided on the inner side of the water seal seat with an interference fit. The sleeve is fitted onto the bottom of the protective sleeve, and the glow plug passes through the protective sleeve and the sleeve.
[0013] Furthermore, the methanol injector includes a methanol injection valve and a second sleeve, which is fitted onto the bottom of the methanol injection valve.
[0014] Furthermore, cooling water inlets are provided at the bottom of both sides of the intake valve hole and at the bottom of one side of the cylinder head. Several cooling water inlets connect the fuel injector hole, the intake valve hole, the cooling water passage, and the cooling water chamber.
[0015] Furthermore, there are six cooling water inlets, which form two cooling water channels. One cooling water channel connects the intake valve hole, the first cooling water channel, and the cooling water chamber, while the other cooling water channel connects the fuel injector hole, the intake valve hole, and the cooling water chamber.
[0016] The beneficial effects of this utility model are:
[0017] This invention does not change the main structure of the existing cylinder head, does not require redesigning the cylinder head mold, ensures the stability of the cylinder head, and is simple and reliable. By setting a methanol injector inside the injector hole, direct injection of methanol fuel into the cylinder can be achieved. By setting a glow plug device inside the intake valve hole, the in-cylinder mixture can be ignited. This invention can arrange the glow plug device and the methanol injector on the cylinder head at the same time, realizing direct injection of methanol fuel into the cylinder and glow plug ignition for small and medium diameter marine engines. Attached Figure Description
[0018] Figure 1 This is a cross-sectional structural diagram of the present invention;
[0019] Figure 2 This utility model Figure 1 Sectional view along line AA in the middle;
[0020] Figure 3This utility model Figure 2 BB-direction sectional view in the middle;
[0021] Figure 4 This is a schematic diagram of the exploded structure of the glow plug device of this utility model;
[0022] Figure 5 This is a schematic diagram of the exploded structure of the methanol injector of this utility model.
[0023] In the diagram: 1. Cylinder head; 11. Tangential intake manifold; 12. Spiral intake manifold; 13. Injector hole; 14. Intake valve hole; 15. Cooling water channel one; 16. Cooling water inlet; 17. Cooling water chamber; 18. Cooling water channel two; 19. Intake port; 2. Glow plug assembly; 21. Glow plug; 211. Hot head coil; 22. Sheath one; 221. Rib plate; 23. Water seal seat; 231. Water chamber; 232. Sheath; 3. Methanol injector; 31. Methanol injection valve; 32. Sheath two. Detailed Implementation
[0024] The present invention will now be described and explained in detail with reference to the accompanying drawings.
[0025] Example 1
[0026] like Figure 1-5 As shown, the methanol direct injection marine engine cylinder head includes a cylinder head 1. A fuel injector hole 13 is provided through the middle of the cylinder head 1. A methanol injector 3 is installed inside the fuel injector hole 13. A plurality of intake valve holes 14 are evenly spaced and arranged circumferentially on the outer side of the fuel injector hole 13. Both the fuel injector hole 13 and the intake valve holes 14 are cylindrical in shape. A glow plug device 2 is installed inside one of the intake valve holes 14. A plurality of cooling water channels 15 are connected to the bottom of the fuel injector hole 13 and the plurality of intake valve holes 14. The plurality of cooling water channels 15 are located between two adjacent intake valve holes 14. The ends of the plurality of cooling water channels 15 away from the fuel injector hole 13 are all connected to the cooling water chamber 17.
[0027] There are four intake valve holes 14, and four cooling water channels 15 are provided in coordination.
[0028] An air inlet 19 is provided on one side of the cylinder head 1. A tangential air inlet 11 and a spiral air inlet 12 are provided inside the cylinder head 1. One end of the tangential air inlet 11 is connected to the air inlet 19, and the other end of the tangential air inlet 11 is connected to two of the air inlet valve holes 14, including an air inlet valve hole 14 with a glow plug device 2 inside. The spiral air inlet 12 is connected to the other two air inlet valve holes 14.
[0029] With the above configuration, the present invention places the glow plug device 2 in the intake valve hole 14 and the methanol injector 3 in the fuel injector hole 13, and cools it through the cooling water channel 15. It does not change the main structure of the cylinder head 1, does not require redesigning the cylinder head 1, ensures the stability of the cylinder head, and the method is simple and reliable. When the engine is running, the methanol injector 3 injects methanol into the cylinder, which mixes with the air in the spiral intake channel 12 to form a mixed atmosphere. The glow plug device 2 ignites the mixed atmosphere, and the methanol burns in the cylinder to do work.
[0030] The glow plug device 2 includes a glow plug 21, a sheath 22, and a water seal seat 23. The water seal seat 23 is interference-fitted to the bottom of the intake valve hole 14 and is fitted onto the bottom of the sheath 22. The sheath 22 is fitted onto the lower part of the glow plug 21 and is threadedly connected to the inner wall of the intake valve hole 14. The glow plug 21 passes through the sheath 22 and the water seal seat 23 and extends into the cylinder.
[0031] The glow plug 21 includes a heating coil 211 disposed at the bottom, which extends into the cylinder.
[0032] The bottom of the inner side of the sheath 22 is provided with several ribs 221 for assisting in the positioning of the glow plug 21, which are evenly and intermittently arranged along the circumference.
[0033] A water cavity 231 is provided on the outer side of the water seal seat 23, and a sleeve 232 is provided on the inner side of the water seal seat 23. The sleeve 232 is fitted on the bottom of the protective sleeve 22, and the glow plug 21 passes through the protective sleeve 22 and the sleeve 232.
[0034] With the above setup, the sleeve 22 is connected to the cylinder head water channel to cool the glow plug device 2 and the cylinder head combustion surface; the water seal seat 23 is interference-fitted into the cylinder head 1, and each water seal seat 23 needs to be matched with an interference-fitted sleeve 232. After the sleeve 232 is installed, the cooling water channel 18 is drilled through, and then the sleeve 22 and the glow plug 21 are pressed into the intake valve hole 14 in sequence. The hot head coil 211 extends into the cylinder interior by about 3-5mm to provide an ignition source for the mixed atmosphere.
[0035] The methanol injector 3 includes a methanol injection valve 31 and a second sleeve 32, with the second sleeve 32 fitted onto the bottom of the methanol injection valve 31.
[0036] With the above settings, the methanol injection valve 31 can spray out a methanol jet to atomize the methanol fuel and mix it with the air in the cylinder.
[0037] Cooling water inlets 16 are provided at the bottom of both sides of the intake valve hole 14 and at the bottom of one side of the cylinder head 1. Several cooling water inlets 16 connect the injector hole 13, the intake valve hole 14, the cooling water passage 15 and the cooling water chamber 17.
[0038] There are six cooling water inlets 16, which form two cooling water channels 2 18. One cooling water channel 2 18 connects the intake valve hole 14, the first cooling water channel 15 and the cooling water chamber 17, and the other cooling water channel 2 18 connects the fuel injector hole 13, the intake valve hole 14 and the cooling water chamber 17.
[0039] With the above setup, after the water seal seat 23 is installed, it is necessary to drill through the cooling water channel 2 18. The cooling water channel 2 18 must be drilled before the protective sleeve 22 is installed and after the seal 232 is installed. Figure 3 The two dotted lines in the diagram represent the drill bit's feed path. The drill bit should penetrate to the cooling water channel 15 or the fuel injector hole 13.
Claims
1. A methanol direct injection marine engine cylinder head, comprising a cylinder head (1), characterized in that, A fuel injector hole (13) is provided through the middle of the cylinder head (1). A methanol injector (3) is installed inside the fuel injector hole (13). A number of intake valve holes (14) are provided evenly and at intervals along the circumference of the outer side of the fuel injector hole (13). The fuel injector hole (13) and the intake valve holes (14) are both cylindrical in shape. A glow plug device (2) is installed inside one of the intake valve holes (14). A number of cooling water channels (15) are connected to the bottom of the fuel injector hole (13) and the intake valve holes (14). The cooling water channels (15) are located between two adjacent intake valve holes (14). The end of the cooling water channels (15) away from the fuel injector hole (13) is connected to the cooling water chamber (17).
2. The methanol direct injection marine engine cylinder head according to claim 1, characterized in that, There are four intake valve holes (14) and four cooling water channels (15) are provided in coordination.
3. The methanol direct injection marine engine cylinder head according to claim 1, characterized in that, An air inlet (19) is provided on one side of the cylinder head (1). A tangential air inlet (11) and a spiral air inlet (12) are provided inside the cylinder head (1). One end of the tangential air inlet (11) is connected to the air inlet (19), and the other end of the tangential air inlet (11) is connected to two of the air inlet valve holes (14) including an internally installed glow plug device (2). The spiral air inlet (12) is connected to the other two air inlet valve holes (14).
4. The methanol direct injection marine engine cylinder head according to claim 1, characterized in that, The glow plug device (2) includes a glow plug (21), a sheath (22) and a water seal seat (23). The water seal seat (23) is interference-fitted to the bottom of the intake valve hole (14) and is fitted onto the bottom of the sheath (22). The sheath (22) is fitted onto the lower part of the glow plug (21) and is threaded to the inner wall of the intake valve hole (14). The glow plug (21) passes through the sheath (22) and the water seal seat (23) and extends into the cylinder.
5. The methanol direct injection marine engine cylinder head according to claim 4, characterized in that, The glow plug (21) includes a hot head coil (211) located at the bottom, which extends into the cylinder.
6. The methanol direct injection marine engine cylinder head according to claim 4, characterized in that, The bottom of the inner side of the sheath (22) is provided with several ribs (221) for positioning the auxiliary glow plug (21) evenly and at intervals along the circumference.
7. The methanol direct injection marine engine cylinder head according to claim 4, characterized in that, A water cavity (231) is provided on the outer side of the water seal seat (23), and a sleeve (232) is provided on the inner side of the water seal seat (23). The sleeve (232) is fitted on the bottom of the first protective sleeve (22), and the glow plug (21) passes through the first protective sleeve (22) and the sleeve (232).
8. The methanol direct injection marine engine cylinder head according to claim 1, characterized in that, The methanol injector (3) includes a methanol injection valve (31) and a second sleeve (32), which is fitted onto the bottom of the methanol injection valve (31).
9. The methanol direct injection marine engine cylinder head according to claim 1, characterized in that, Cooling water inlets (16) are provided at the bottom of both sides of the intake valve hole (14) and at the bottom of one side of the cylinder head (1). Several cooling water inlets (16) connect the injector hole (13), the intake valve hole (14), the cooling water passage (15) and the cooling water chamber (17).
10. The methanol direct injection marine engine cylinder head according to claim 9, characterized in that, There are six cooling water inlets (16), which form two cooling water channels (18). One of the cooling water channels (18) connects the intake valve hole (14), the first cooling water channel (15), and the cooling water chamber (17). The other cooling water channel (18) connects the injector hole (13), the intake valve hole (14), and the cooling water chamber (17).