An injector, combustion chamber and engine

Abstract

The present application relates to a kind of injector, combustion chamber and engine, injector includes shell and valve body, the bottom of shell is provided to the jet hole that is inclined to the direction away from combustion chamber cylinder wall, valve body is set in shell, and can reciprocate between opening position and closed position along its own axial direction, when valve body is in opening position, the flow area between valve body and shell is greater than 0, when valve body is in closed position, the flow area between valve body and shell is 0, the valve stem of valve body is provided with the flow guide structure that fuel gas stream is guided into spiral airflow.The above-mentioned injector is single-hole directional injection, can form high penetration distance rotational flow jet, so that as much fuel fluid as possible is injected to the center of combustion chamber, reduce the amount of fuel reaching cylinder wall, so as to reduce combustion loss, improve combustion thermal efficiency, rotating airflow is also more conducive to gas mixing, enhance combustion efficiency, further improve combustion thermal efficiency, and help to reduce the probability of unburned gas in next working cycle causing early combustion.

Description

Technical Field

[0001] This invention relates to the field of engine technology, and in particular to an injector, a combustion chamber, and an engine. Background Technology

[0002] For direct injection gas engines, gas fluid needs to be injected into the engine's combustion chamber through an injector.

[0003] The existing injector includes a housing and a valve body disposed within the housing. A valve plate is disposed at the bottom of the valve body. The valve body reciprocates relative to the housing along its own axis to adjust the gap between the valve plate and the bottom end face of the housing, thereby realizing the opening and closing of the injector.

[0004] When the aforementioned injector is in the open state, there is a gap between the valve plate and the housing throughout the entire circumference. As a result, the fuel is sprayed out in all directions, the airflow is dispersed, the penetration distance is short, and the mixing effect is poor. Furthermore, because the injector needs to make way for the spark plug in the center of the combustion chamber, the injector is close to the cylinder wall on the side of the combustion chamber. During injection, a considerable portion of the fuel is injected onto the cylinder wall, forming a wall quenching effect, which reduces the combustion thermal efficiency and further reduces the fuel mixing effect. Some unmixed and unburned fuel directly reaches the exhaust valve. When the exhaust valve opens, the fuel is discharged, further reducing the thermal efficiency. Ultimately, this results in low fuel utilization, low overall thermal efficiency, and the residual unburned fuel is very likely to cause engine pre-ignition. Summary of the Invention

[0005] The first objective of this invention is to provide an injector that improves the gas mixing effect, avoids the wall quenching effect, increases gas utilization and combustion thermal efficiency, and prevents engine pre-ignition.

[0006] A second objective of the present invention is to provide a combustion chamber and an engine that include the above-described injector.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] In a first aspect of this application, an injector is provided for injecting fuel into a combustion chamber, comprising:

[0009] The casing has a nozzle at the bottom that is inclined away from the cylinder wall of the combustion chamber;

[0010] The valve body is disposed within the housing and is capable of reciprocating between an open position and a closed position relative to the housing along its own axial direction. When the valve body is in the open position, the flow cross-sectional area between the valve body and the housing is greater than 0. When the valve body is in the closed position, the flow cross-sectional area between the valve body and the housing is 0. The valve stem of the valve body is provided with a flow guiding structure for guiding the passing fuel gas flow into a spiral gas flow.

[0011] In one possible implementation, the housing includes:

[0012] A valve seat is sleeved on the valve stem of the valve body. A valve plate is provided at the lower end of the valve stem of the valve body. When the valve body is in the closed position, the valve plate is in contact with the bottom end face of the valve seat. When the valve body is in the open position, the valve plate is in clearance fit with the bottom end face of the valve seat.

[0013] The cap is a cover that is open at one end and closed at the other end. The cap is located at the bottom of the valve seat and covers the bottom of the valve seat and the valve plate. The spray hole is located at the closed end of the cap.

[0014] In one possible implementation, the angle α between the axis of the nozzle and the axis of the injector satisfies 10°≤a≤30°.

[0015] In one possible implementation, the flow guiding structure includes:

[0016] A flow guide cap is coaxially arranged with the valve stem of the valve body. A first flow passage gap is formed between the flow guide cap and the housing. Multiple through holes are evenly distributed around the flow guide cap, and each through hole forms a second flow passage gap.

[0017] A guide plate is provided at least on the side of the guide cap near the nozzle. One end of the guide plate extends radially from the valve stem of the valve body toward the edge of the guide cap and gradually bends away from the meridian direction of the guide cap. At least one through hole is provided between two adjacent guide plates.

[0018] In one possible implementation, the two side surfaces of the flow guide cap along the axial direction are curved surfaces that arch towards the lower end of the valve stem away from the valve body.

[0019] In one possible implementation, the diameter of the nozzle is 3mm to 6mm.

[0020] As can be seen from the above technical solutions, the injector provided by the present invention includes a housing and a valve body. The bottom of the housing is provided with a spray hole that is inclined away from the cylinder wall of the combustion chamber. The valve body is disposed inside the housing and can reciprocate between an open position and a closed position relative to the housing along its own axis. When the valve body is in the open position, the flow cross-sectional area between the valve body and the housing is greater than 0. When the valve body is in the closed position, the flow cross-sectional area between the valve body and the housing is 0. A flow guiding structure is provided on the valve stem of the valve body to guide the passing fuel gas flow into a spiral gas flow.

[0021] In application, the fuel fluid entering the injector first passes through the guide structure and becomes a pre-preset swirling airflow. The swirling airflow is then directed downwards from the nozzle and injected into the combustion chamber. Because it is a single-hole directional injection, a high-penetration swirling jet can be formed, thereby injecting as much fuel fluid as possible into the center of the combustion chamber, reducing the amount of fuel reaching the cylinder wall, thus reducing combustion loss and improving combustion thermal efficiency. The swirling airflow is also more conducive to gas-fuel mixing, enhancing combustion efficiency and further improving combustion thermal efficiency. It also helps to reduce the probability of unburned gas causing pre-ignition in the next working cycle.

[0022] In a second aspect of this application, a combustion chamber is provided, which is formed by a cylinder head, a cylinder and a piston. The cylinder head is provided with an injector as described in the first aspect and its possible implementations. The injector is offset from the central axis of the combustion chamber, and one end of the injector with a nozzle extends into the combustion chamber.

[0023] In one possible implementation, the piston has a combustion chamber recess on its top, and the piston top surface is formed around the combustion chamber recess. A circumferential flange is provided on the circumferential surface of the combustion chamber recess, and a first guide surface is provided on the side of the circumferential flange near the piston top surface. The injector is located above the piston top surface, and the nozzle of the injector faces the first guide surface.

[0024] In one possible implementation, the angle α between the axis of the nozzle and the axis of the injector satisfies 10°≤a≤30°, and the angle b between the first guide surface and the top surface of the piston satisfies 20°≤b≤40°, and b>a.

[0025] In one possible implementation, the bottom of the combustion chamber recess is provided with a central boss protruding towards the bottom surface of the cylinder head, and the circumferential surface of the combustion chamber recess is provided with a second guide surface on the side of the circumferential flange near the bottom of the combustion chamber recess. The second guide surface, the bottom surface of the combustion chamber recess, and the circumferential surface of the central boss are smoothly connected in sequence.

[0026] In one possible implementation, the angle c between the circumferential surface of the central boss and the axis of the piston satisfies 60°≤c≤80°, and the sum of the angle a between the axis of the nozzle and the axis of the injector and the angle c between the circumferential surface of the central boss and the axis of the piston satisfies 90°≤(a+c)≤110°.

[0027] In a third aspect of this application, an engine is provided, including a combustion chamber as described in the second aspect and its possible implementations.

[0028] Since the combustion chamber and engine employ the injector described in the first aspect and its possible implementations, the combustion chamber and engine should have the same beneficial effects as the aforementioned injector, which will not be elaborated further here. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the injector provided in an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of the structure of the injector cap provided in an embodiment of the present invention;

[0032] Figure 3 A schematic diagram of the valve body of the injector provided in an embodiment of the present invention. Figure 1 ;

[0033] Figure 4 A schematic diagram of the valve body of the injector provided in an embodiment of the present invention. Figure 2 ;

[0034] Figure 5 A schematic diagram of the flow guiding structure of the valve body of the injector provided in an embodiment of the present invention;

[0035] Figure 6 This is a schematic diagram of the combustion chamber provided in an embodiment of the present invention.

[0036] In the picture:

[0037] 100 is the housing; 110 is the valve seat; 120 is the cover; 121 is the end plate; 122 is the side wall plate; 200 is the valve body; 210 is the valve stem; 220 is the valve plate; 230 is the flow guiding structure; 231 is the flow guiding cap; 232 is the through hole; 233 is the flow guiding plate; 300 is the nozzle; 400 is the combustion chamber recess; 410 is the circumferential flange; 420 is the first flow guiding surface; 430 is the second flow guiding surface; 440 is the central boss; 441 is the circumferential surface of the central boss; 500 is the piston top surface; 600 is the spark plug. Detailed Implementation

[0038] One of the core aspects of this invention is to provide an injector whose structural design can improve the gas mixing effect, avoid the wall quenching effect, improve gas utilization and combustion thermal efficiency, and prevent engine pre-ignition.

[0039] Another core aspect of this invention is to provide a combustion chamber including the aforementioned injector and an engine.

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] This application provides an injector, such as... Figure 1 As shown, the injector includes a housing 100 and a valve body 200.

[0042] The housing 100 is used to cooperate with the cylinder head to fix the injector on the cylinder head. The bottom of the housing 100 is used to extend into the combustion chamber. The bottom of the housing 100 is provided with an injection hole 300 that is inclined away from the cylinder wall of the combustion chamber.

[0043] The valve body 200 is disposed within the housing 100 and can reciprocate between the open and closed positions relative to the housing 100 along its own axial direction. When the valve body 200 is in the open position, the flow cross-sectional area between the valve body 200 and the housing 100 is greater than 0. It should be noted that the valve body 200 can have multiple open positions, and the flow cross-sectional area between the valve body 200 and the housing 100 is different in each open position. The fuel fluid can flow to the nozzle 300 through the gap between the valve body 200 and the housing 100. When the valve body 200 is in the closed position, the flow cross-sectional area between the valve body 200 and the housing 100 is 0, and the fuel fluid cannot flow to the nozzle 300 through the gap between the valve body 200 and the housing 100. A flow guiding structure 230 is provided on the valve stem 210 of the valve body 200 to guide the passing fuel gas flow into a spiral airflow.

[0044] The fuel injected by the injector provided in this application embodiment includes, but is not limited to, hydrogen, natural gas, ammonia, and other gaseous gases.

[0045] Compared with the prior art, the injector provided in this application embodiment, when applied, the fuel fluid entering the injector first passes through the guide structure 230 and becomes a pre-preset swirling airflow. The swirling airflow is then directionally injected into the combustion chamber from the nozzle 300. Since it is a single-hole directional injection, a high-penetration swirling jet can be formed, thereby injecting as much fuel fluid as possible into the center of the combustion chamber, reducing the amount of fuel reaching the cylinder wall, thereby reducing combustion loss and improving combustion thermal efficiency. The increased penetration distance and swirling airflow are also more conducive to gas-fuel mixing, enhancing combustion efficiency and further improving combustion thermal efficiency. It also helps to reduce the probability of unburned gas causing pre-ignition in the next working cycle.

[0046] Please see Figure 1 and Figure 2 In one embodiment of this application, the housing 100 includes a valve seat 110 and a cap 120. The valve seat 110 is sleeved on the valve stem 210 of the valve body 200. A valve plate 220 is provided at the lower end of the valve stem 210 of the valve body 200. When the valve body 200 is in the closed position, the valve plate 220 is in contact with the bottom end face of the valve seat 110. When the valve body 200 is in the open position, the valve plate 220 is in clearance fit with the bottom end face of the valve seat 110.

[0047] Please continue reading. Figure 1 The circumferential surface of the valve plate 220 is provided with a first conical surface, and the bottom end face of the valve seat 110 is provided with a second conical surface. When the valve body 200 is in the closed position, the first conical surface and the second conical surface are in contact and cooperate to ensure the sealing effect when closed.

[0048] The cap 120 is a cover that is open at one end and closed at the other end. The cap 120 is set at the bottom of the valve seat 110, covering the bottom of the valve seat 110 and the valve plate 220. The spray hole 300 is set at the closed end of the cap 120 at the bottom of the housing 100. The cap 120 and the valve body 200 can be an integral structure, or fixedly connected by welding, or connected by a detachable connection structure such as a threaded connection.

[0049] Specifically, such as Figure 1 and Figure 2 As shown, the cap 120 includes an end plate 121 and a circumferentially closed side wall plate 122 that rises from the periphery of the end plate 121. The side wall plate 122 is engaged with the bottom of the valve seat 110. The end plate 121 is the closed end of the cap 120, and the spray hole 300 is disposed on the end plate 121.

[0050] It is foreseeable that the angle α between the axis of the nozzle 300 and the axis of the injector is related to the injection direction of the gas fluid. It needs to be designed according to the position of the injector in the combustion chamber, the structure of the piston, and the flow field simulation definition. In the embodiment of this application, the angle α between the axis of the nozzle 300 and the axis of the injector satisfies 10°≤a≤30°.

[0051] Please see Figure 1 , Figure 3 , Figure 4 as well as Figure 5 In one embodiment of this application, the flow guiding structure 230 includes a flow guiding cap 231 and a flow guiding plate 233. The flow guiding cap 231 is coaxially arranged with the valve stem 210 of the valve body 200. A first flow passage gap is formed between the flow guiding cap 231 and the housing 100. A plurality of through holes 232 are evenly distributed around the flow guiding cap 231, and each through hole 232 forms a second flow passage gap. The fuel fluid passes through the flow guiding structure 230 from the first flow passage gap and the second flow passage gap.

[0052] In this embodiment, at least one of the two surfaces of the flow guide cap 231 along the axial direction is provided with a plurality of flow guide plates 233 evenly distributed circumferentially. It should be noted that through holes 232 caused by process errors and human errors, as well as the non-uniform distribution of flow guide plates 233 in the circumferential direction, are also within the scope of protection of this solution. Furthermore, the flow guide plates 233 are at least provided on the side of the flow guide cap 231 near the nozzle 300. One end of the flow guide plate 233 extends radially from the valve stem 210 of the valve body 200 to the edge of the flow guide cap 231 and gradually bends away from the meridian direction of the flow guide cap 231. At least one through hole 232 is provided between two adjacent flow guide plates 233. The flow guide plates 233 can guide the fuel fluid passing through the through hole 232 to form a rotating airflow.

[0053] Of course, based on the above structure, the guide plate 233 can also be twisted from the end closest to the valve stem 210.

[0054] To further optimize the above technical solution, the two sides of the guide cap 231 in the axial direction are curved surfaces that arch towards the lower end of the valve stem 210 away from the valve body 200, so that the guide cap 231 forms an umbrella-shaped structure. This allows the valve body 200 to move upward as a whole when it moves to the closed position, reducing gas resistance, and to move downward as it moves to the open position, increasing gas gathering and gas thrust.

[0055] Furthermore, each guide plate 233 can also act as a reinforcing rib, increasing the overall structural strength of the guide structure 230.

[0056] In one embodiment of this application, the thickness of the flow guide cap 231 and the flow guide plate 233 is 0.5mm~1mm, and the maximum outer diameter of the flow guide cap 231 is smaller than the inner diameter of the valve seat 110 to form a first flow passage gap.

[0057] It should be noted that the above-described flow guiding structure 230 is merely a preferred embodiment provided in this application, and is not actually limited to this. Other methods can also be used to guide the fuel fluid. For example, the flow guide plate 233 may not be provided; instead, the through holes 232 may be inclined, using the through holes 232 to guide the fuel fluid into a spiral fluid. The above-mentioned through holes 232 can be circumferentially closed through holes 232, or the through holes 232 can be set at the edge of the flow guide cap 231, forming circumferentially open through holes 232.

[0058] Alternatively, in other embodiments, the flow guide cap 231 can be directly omitted, and multiple circumferentially distributed spiral flow guides 233 can be used to guide the fuel fluid into a spiral fluid.

[0059] Preferably, in one embodiment of this application, the diameter of the nozzle 300 is 3mm to 6mm.

[0060] This application embodiment also provides a combustion chamber, which is formed by a cylinder head, a cylinder, and a piston. The cylinder head is located above the cylinder and is sealed to the cylinder. The piston is reciprocally disposed inside the cylinder. The cylinder head is provided with an intake passage, an exhaust passage, an intake throttle valve, and an exhaust throttle valve. The intake passage and the exhaust passage are respectively connected to the combustion chamber. The intake throttle valve is disposed in the intake passage and is used to control the intake of the combustion chamber. The exhaust throttle valve is disposed in the exhaust passage and is used to control the exhaust of the combustion chamber.

[0061] The cylinder head is provided with an injector as described in the above embodiment. Since the spark plug 600 is provided at the center of the combustion chamber, the injector is offset from the central axis of the combustion chamber. The end of the injector with the nozzle 300 extends into the combustion chamber. Since the combustion chamber uses the injector described in the above embodiment, please refer to the above embodiment for the technical effect of the combustion chamber.

[0062] Please see Figure 6In one embodiment of this application, in order to form a strong tumble flow in the combustion chamber and further enhance the gas mixing effect, a combustion chamber recess 400 is provided on the top of the piston, and a piston top surface 500 is formed around the combustion chamber recess 400 on the top of the piston. A circumferential flange 410 is provided on the circumferential surface of the combustion chamber recess 400, and a first guide surface 420 is provided on the side of the circumferential flange 410 near the piston top surface 500. The first guide surface 420 slopes downward from the side near the piston top surface 500. The injector is located above the piston top surface 500, and the nozzle 300 of the injector faces the first guide surface 420. The first guide surface 420 is a circumferentially closed rotary surface.

[0063] The fuel fluid ejected by the injector flows into the combustion chamber recess 400 under the guidance of the first guide surface 420. While forming a tumble flow in the combustion chamber recess 400, it avoids fuel loss that is directly discharged from the exhaust valve, thereby reducing thermal efficiency loss.

[0064] Preferably, in one embodiment of this application, the angle α between the axis of the nozzle 300 and the axis of the injector satisfies 10°≤a≤30°, and the angle b between the first guide surface 420 and the piston top surface 500 satisfies 20°≤b≤40°, and b>a.

[0065] Further optimize the above technical solutions, such as Figure 6 As shown, a central boss 440 protruding towards the bottom surface of the cylinder head is provided at the bottom of the combustion chamber recess 400. A second guide surface 430 is provided on the side of the circumferential flange 410 near the bottom of the combustion chamber recess 400. The second guide surface 430, the bottom surface of the combustion chamber recess 400 and the circumferential surface 441 of the central boss 440 are smoothly connected in sequence. The second guide surface 430 and the circumferential surface 441 of the central boss 440 are both circumferentially closed rotary surfaces.

[0066] The plane passing through the piston axis and the injector axis is the central symmetry plane of the combustion chamber. In this application, the intersection of the first guide surface 420 and the central symmetry plane is an inclined straight line segment or a curved segment, the intersection of the circumferential flange 410 and the central symmetry plane is a curved segment protruding towards the central boss 440, the intersection of the second guide surface 430 and the central symmetry plane is a curved segment protruding away from the central boss 440, and the intersection of the circumferential surface 441 of the central boss 440 and the central symmetry plane is an inclined straight line segment or a curved segment.

[0067] exist Figure 6 In the embodiment shown, the intersection line of the first guide surface 420 and the central symmetry plane, and the intersection line of the circumferential surface 441 of the central boss 440 and the central symmetry plane are both inclined straight line segments.

[0068] Please continue reading. Figure 6 The angle c between the circumferential surface 441 of the central boss 440 and the piston axis satisfies 60°≤c≤80°, and the sum of the angle a between the axis of the nozzle 300 and the axis of the injector, and the angle c between the circumferential surface 441 of the central boss 440 and the piston axis satisfies 90°≤(a+c)≤110°. It should be noted that the angle b between the first guide surface 420 and the piston top surface 500, and the angle c between the circumferential surface 441 of the central boss 440 and the piston axis are defined comprehensively by combustion chamber structure, combustion, and flow field simulation.

[0069] In application, the first guide surface 420 is used to guide the fuel fluid to the bottom of the combustion chamber recess 400, that is, to allow the fuel fluid to diffuse into the lower region of the combustion chamber and form a cyclone there, which strongly mixes with the intake air to form a strong mixing effect. The second guide surface 430 is used to guide the fuel fluid to the central boss 440 of the combustion chamber recess 400, and to diffuse into the upper region of the combustion chamber through the guidance of the central boss 440, forming a strong tumble effect. Tumble continues to form at the top of the combustion chamber. After passing through the central boss 440, part of the gas mixture continues to form a mixing effect on the other side of the central boss 440. This makes the gas mixing of the combustion chamber provided in this embodiment of the application good and the combustion efficiency high, thereby improving the combustion thermal efficiency, which helps the fuel to burn completely, reduces the emission of unburned gas, and reduces the probability of pre-ignition caused by unburned gas in the next working cycle.

[0070] This application also provides an engine that includes a combustion chamber as described in the above embodiments. Since the engine uses the combustion chamber described in the above embodiments, the technical effects of the engine can be referred to the above embodiments.

[0071] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "a," and / or "the" are not specifically singular and may include the plural. Generally, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements. An element defined by the phrase "comprising an..." does not exclude the presence of other identical elements in the process, method, product, or apparatus that includes the element.

[0072] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0073] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0074] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the core ideas of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. An injector for injecting fuel into a combustion chamber, characterized in that, include: The housing (100) has an injection hole (300) at the bottom that is inclined away from the cylinder wall of the combustion chamber. A valve body (200) is disposed within the housing (100) and is capable of reciprocating between an open position and a closed position relative to the housing (100) along its own axial direction. When the valve body (200) is in the open position, the flow cross-sectional area between the valve body (200) and the housing (100) is greater than 0. When the valve body (200) is in the closed position, the flow cross-sectional area between the valve body (200) and the housing (100) is 0. A flow guiding structure (230) is provided on the valve stem (210) of the valve body (200) to guide the passing fuel gas flow into a spiral airflow. The flow guiding structure (230) includes a flow guiding cap (231) and a flow guiding plate (233). The flow guiding cap (231) The flow guide cap (231) is coaxially arranged with the valve stem (210) of the valve body (200). A first flow passage gap is formed between the flow guide cap (231) and the housing (100). The flow guide cap (231) is circumferentially distributed with a plurality of through holes (232), and each of the through holes (232) forms a second flow passage gap. The flow guide plate (233) is at least disposed on the side of the flow guide cap (231) near the nozzle (300). One end of the flow guide plate (233) extends radially from the valve stem (210) of the valve body (200) toward the edge of the flow guide cap (231) and gradually bends away from the meridian direction of the flow guide cap (231). At least one of the through holes (232) is disposed between two adjacent flow guide plates (233).

2. The injector according to claim 1, characterized in that, The housing (100) includes: A valve seat (110) is sleeved on the valve stem (210) of the valve body (200). A valve plate (220) is provided at the lower end of the valve stem (210) of the valve body (200). When the valve body (200) is in the closed position, the valve plate (220) is in contact with the bottom end face of the valve seat (110). When the valve body (200) is in the open position, the valve plate (220) is in clearance fit with the bottom end face of the valve seat (110). The cap (120) is a cover that is open at one end and closed at the other end. The cap (120) is located at the bottom of the valve seat (110) and covers the bottom of the valve seat (110) and the valve plate (220). The spray hole (300) is located at the closed end of the cap (120).

3. The injector according to claim 1, characterized in that, The angle α between the axis of the nozzle (300) and the axis of the injector satisfies 10°≤a≤30°.

4. The injector according to any one of claims 1-3, characterized in that, The two sides of the flow guide cap (231) in the axial direction are curved surfaces that arch towards the lower end of the valve stem (210) away from the valve body (200).

5. The injector according to any one of claims 1-3, characterized in that, The diameter of the nozzle (300) is 3mm to 6mm.

6. A combustion chamber, comprising a cylinder head, a cylinder, and a piston, characterized in that, The cylinder head is provided with an injector as described in any one of claims 1-5, the injector being offset from the central axis of the combustion chamber, and one end of the injector having a nozzle (300) extending into the combustion chamber.

7. The combustion chamber according to claim 6, characterized in that, The piston has a combustion chamber recess (400) on its top, and the piston top surface (500) is formed around the combustion chamber recess (400). A circumferential flange (410) is provided on the circumferential surface of the combustion chamber recess (400). A first guide surface (420) is provided on the side of the circumferential flange (410) near the piston top surface (500). The injector is located above the piston top surface (500), and the nozzle (300) of the injector faces the first guide surface (420).

8. The combustion chamber according to claim 7, characterized in that, The angle α between the axis of the nozzle (300) and the axis of the injector satisfies 10°≤a≤30°, and the angle b between the first guide surface (420) and the piston top surface (500) satisfies 20°≤b≤40°, and b>a.

9. The combustion chamber according to claim 8, characterized in that, The bottom of the combustion chamber recess (400) is provided with a central boss (440) protruding towards the bottom surface of the cylinder head. The circumferential surface of the combustion chamber recess (400) is provided with a second guide surface (430) on the side of the circumferential flange (410) near the bottom of the combustion chamber recess (400). The second guide surface (430), the bottom surface of the combustion chamber recess (400) and the circumferential surface (441) of the central boss (440) are connected in a smooth transition.

10. The combustion chamber according to claim 9, characterized in that, The angle c between the circumferential surface (441) of the central boss (440) and the axis of the piston satisfies 60°≤c≤80°, and the sum of the angle a between the axis of the nozzle (300) and the axis of the injector and the angle c between the circumferential surface (441) of the central boss (440) and the axis of the piston satisfies 90°≤(a+c)≤110°.

11. An engine, characterized in that, Includes the combustion chamber as described in any one of claims 6-10.

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