injector

Abstract

The present application provides a kind of injector, reduce the influence of supply pressure, and facilitate the valve core opening valve.Jet (1) includes: main body part (10), it is formed with the flow path (FP) of the gas fuel being supplied from flow inlet (11) and flows to the side of flow outlet (12) at least one part of axial direction;Valve shaft part (20) is arranged to be able to advance and retreat in the inside of main body part (10) in axial direction, and valve core (24) is arranged in front end part and is closed to flow outlet (12);Spring (31) is driven to valve shaft part (20) in the direction of retreat and closes the valve of flow outlet (12) by force;And solenoid (40) is driven to valve shaft part (20) in the direction of advance by the elasticity of spring (31) in opposition, and flow outlet (12) is opened to valve, and valve shaft part (20) includes pressure part (25), which is subjected to the pressure of gas fuel flowing in flow path (FP) in the direction of retreat.

Description

Technical Field

[0001] This invention relates to an injector. Background Technology

[0002] Previously, as an injector installed in a vehicle for injecting fuel, a direct injection injector that directly injects fuel into the cylinder of an engine is known. It is well known that such direct injection injectors also employ an externally opening structure, i.e., a structure that closes the valve by pulling the valve core closer to the valve seat (for example, see Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1

[0006] Japanese Patent Application Publication No. 2001-082254 Summary of the Invention

[0007] The technical problem that the invention aims to solve

[0008] In the aforementioned externally opening injector, to prevent the valve core from opening unexpectedly due to the pressure of the supplied gaseous fuel, a spring is used to pull the valve core closer to the valve seat to close the valve, thus counteracting the pressure. However, when the pressure inside the main body is low, there is a problem that the spring load is too large, making it difficult for the valve core to open. If the electromagnetic attraction of the solenoid is increased to counteract the spring load, the following problems will occur: the impact during valve closure increases, leading to decreased durability and quietness, which is related to the increase in size and cost associated with the enlargement of the device.

[0009] The present invention was made in view of the above-mentioned technical problems, and its object is to provide an injector that reduces the influence of gaseous fuel pressure and facilitates valve core opening.

[0010] Technical solutions adopted to solve technical problems

[0011] According to one aspect of the present invention, an electromagnetically driven injector for injecting gaseous fuel into a cylinder of an engine comprises: a main body having at least a portion of a flow path for the gaseous fuel supplied from an inlet to flow axially toward an outlet; a valve shaft having a valve core disposed within the main body for axial movement, and having a valve core at a front end for opening and closing the outlet; a spring having a force applied to the valve shaft in a retracting direction to close the outlet; and a solenoid having elastically driven the valve shaft in a forward direction against the spring to open the outlet, the valve shaft including a pressure-bearing portion that bears the pressure of the gaseous fuel flowing within the flow path in a retracting direction.

[0012] Invention Effects

[0013] According to the present invention, an injector can be provided that reduces the influence of supply pressure and facilitates valve opening. Attached Figure Description

[0014] Figure 1 This is a perspective view illustrating an example of an embodiment of the injector of the present invention.

[0015] Figure 2 This is a top view illustrating an example of an embodiment of the injector of the present invention.

[0016] Figure 3 yes Figure 2 The AA section view shown.

[0017] Figure 4 yes Figure 2 The BB cross-sectional view shown.

[0018] Figure 5 yes Figure 3 Enlarged sectional view of the main part.

[0019] Figure 6A This is a perspective view showing the inflow side block in an example of an embodiment of the injector of the present invention.

[0020] Figure 6B This is a front view of the inflow side block, illustrating an example of an embodiment of the injector of the present invention.

[0021] Figure 6C This is a top view showing an example of an embodiment of the injector of the present invention, specifically the inflow side block.

[0022] Figure 6D yes Figure 6B The shown is a CC sectional view.

[0023] Figure 6E yes Figure 6C The DD sectional view shown.

[0024] Figure 7A This is a perspective view of a bearing block in an example of an embodiment of the injector of the present invention.

[0025] Figure 7B This is a front view of the bearing body in an example of an embodiment of the injector of the present invention.

[0026] Figure 7C This is a top view showing a bearing block in an example of an embodiment of the injector of the present invention.

[0027] Figure 7D yes Figure 7B The EE sectional view shown.

[0028] Figure 7E yes Figure 7C The FF sectional view shown.

[0029] Figure 8A This is a perspective view showing an example of an embodiment of the injector of the present invention, specifically the outflow side block.

[0030] Figure 8B This is a front view of the outflow side block in an example of an embodiment of the injector of the present invention.

[0031] Figure 8C yes Figure 8B The GG cross-sectional view shown.

[0032] Figure 9 This is an enlarged cross-sectional view of the main part of one example of a different embodiment of the injector of the present invention. Detailed Implementation

[0033] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[0034] Figure 1 This is a perspective view showing the outline of the injector according to this embodiment. Figure 2 This is its top view. Figure 3 yes Figure 2 AA section view, Figure 4 yes Figure 2 BB cross-sectional view.

[0035] <Overall Structure of Injector 1>

[0036] The injector 1 illustrated in these figures includes a main body 10, which forms at least a portion of a flow path FP through which gaseous fuel supplied from the inlet 11 flows axially toward the outlet 12 when gaseous fuel is injected into a cylinder of an engine (not shown). Furthermore, when used as a direct injection injector, a nozzle component (not shown) can be separately installed on the outlet 12 side and inserted into the engine cylinder.

[0037] Inside the main body 10, a valve shaft portion 20 is provided, which is coaxially joined by a base end member 21, a plunger member 22, and a front end member 23 in that order, so that it can move axially within the main body 10. A valve core 24 for opening and closing the outlet 12 is provided at the front end 20b of the valve shaft portion 20, but details about the valve shaft portion 20 will be described later.

[0038] Furthermore, a spring 31 and a solenoid 40 are disposed inside the main body 10. The spring 31 applies force to the valve shaft 20 in a backward direction, thereby closing the outlet 12. The solenoid 40, against the elasticity of the spring 31, drives the valve shaft 20 in a forward direction, thereby opening the outlet 12. The "forward direction" referred to here means the direction in which the valve core 24 moves away from the outlet 12. Figure 3 The direction of valve opening is as follows: (below the center) and (i.e., the valve opening direction). Conversely, the "reverse direction" refers to the direction in which the valve core 24 approaches the outlet 12. Figure 3 The direction above the valve (i.e., the direction of valve closure) is the same thereafter.

[0039] In the example shown above, the main body 10 includes an inflow side block 50 with an inlet 11. The inflow side block 50 is configured such that the inlet 11 is open at one end 50a (one end 10a of the main body 10), and gaseous fuel supplied by a fuel supply device not shown flows in from the inlet 11. A receiving portion 30 is formed between the inflow side block 50 and the bearing block 60, which houses the base end 20a of the valve shaft portion 20. The inflow side block 50 and the bearing block 60 are coaxially engaged and held by a cylindrical inflow side bushing 13 disposed around them.

[0040] When the inflow side block 50 and the bearing block 60 are coaxially joined, in the illustrated example, the other end 50b of the inflow side block 50 opposite to the bearing block 60 is formed into a cylindrical shape. Simultaneously, at the other end 60a of the bearing block 60 opposite to the inflow side block 50, the outer diameter of the small-diameter cylindrical portion 61 of the cylindrical other end 50b of the inflow side block 50 is formed with a stepped portion 62 to reduce the diameter of the other end 60a. With this structure, by abutting the stepped portion 62 against the cylindrical other end 50b of the inflow side block 50 and joining it with the small-diameter cylindrical portion 61 of the bearing block 60, coaxiality between the inflow side block 50 and the bearing block 60 is ensured.

[0041] Furthermore, a large-diameter cylindrical portion 63a with an outer diameter capable of being embedded into the inflow-side bushing 13 is formed at one end 60a of the bearing block 60, and a flange-like protrusion 64 protruding circumferentially is formed on the circumferential surface of the large-diameter cylindrical portion 63a. With this structure, when the inflow-side block 50, which is coaxially engaged with the bearing block 60, is held, the end edge of the inflow-side bushing 13 abuts against the protrusion 64, and the inflow-side bushing 13 is engaged with the large-diameter cylindrical portion 63a of the bearing block 60, thus ensuring their coaxiality.

[0042] Furthermore, in the inflow side block 50, a plurality of branched flow paths 51 extending radially outward are formed relative to the inflow inlet 11 formed along the axial direction. In the illustrated example, the four branched flow paths 51, arranged at equal angular intervals along the circumference, are formed to extend in a direction orthogonal to the axial direction.

[0043] The branched flow path 51, as described above, is formed in communication with the inlet 11 as part of the flow path FP for the flow of gaseous fuel supplied from the inlet 11, and opens on the circumferential surface 50c of the inflow side block 50. As shown, the portion of the inflow side block 50, including at least a portion of the opening 52, is formed with a diameter smaller than the diameter of the remaining cylindrical portion 53, whose outer diameter allows it to fit tightly against the inner circumferential surface of the inflow side bushing 13. With this structure, a gap 54 communicating with each branched flow path 51 is formed between the circumferential surface 50c of the inflow side block 50 and the inflow side bushing 13, and this gap 54 forms part of the flow path for the gaseous fuel flow.

[0044] On the other hand, in the bearing block 60, a first shaft hole 65 and a second shaft hole 66, which communicate with the flow path FP for gaseous fuel flow, are formed together with a portion of the flow path FP. The inner diameter of the second shaft hole 66 is larger than the inner diameter of the first shaft hole 65. They are formed to overlap axially and pass through the bearing block 60. The first shaft hole 65 opens at one end 60a of the bearing block 60, and the second shaft hole 66 opens at the other end 60b of the bearing block 60. The first shaft hole 65 is formed to allow the valve shaft portion 20, which moves axially within the body portion 10, to slide through. The second shaft hole 66 is formed to allow the bushing 42 of the solenoid 40 to pass through. This will be described later.

[0045] Furthermore, in the bearing block 60, a plurality of passages 67 extending radially outward are formed relative to the first shaft hole 65 and the second shaft hole 66 formed along the axial direction. In the illustrated example, the four passages 67 arranged at equal angular intervals along the circumference are formed to extend in a direction orthogonal to the axial direction.

[0046] The passage 67 formed as described above, as part of the flow path FP for gaseous fuel flow, is formed in communication with the second shaft hole 66 and opens on the circumferential surface 60c of the bearing block 60. As shown, the portion of the bearing block 60 including at least a portion of the opening on the inflow side block 50 side is formed with a diameter smaller than the diameter of the large-diameter cylindrical portion 63a that engages with the inflow side bushing 13, and is substantially flush with the circumferential surface 60c of the cylindrical end side of the inflow side block 50 that engages with the small-diameter cylindrical portion 61 (the circumferential surface 50c of the small-diameter portion of the inflow side block 50). With this structure, a gap 68 communicating with each passage 67 is formed between the circumferential surface 60c of the bearing block 60 and the inflow side bushing 13, and this gap 68, together with the gap 54 formed between the circumferential surface 50c of the inflow side block 50, forms part of the flow path FP for gaseous fuel flow.

[0047] As a result, the gaseous fuel supplied from the inlet 11 is guided through the branched flow path 51 formed in the inlet side block 50 and the gap 54 formed between the inlet side bushing 13, and then flows through the passage 67 formed in the bearing block 60 and axially to be guided into the interior of the bearing block 60.

[0048] In addition, in one example shown in the figure, the main body 10 includes, in addition to the aforementioned inflow side block 50, bearing block 60 and inflow side bushing 13, an outflow side block 70 with an outlet 12 formed thereon and an outflow side bushing 14 that holds the outflow side block 70 coaxially with the inflow side block 50 and bearing block 60.

[0049] The outflow side bushing 14 is formed with the same diameter as the inflow side bushing 13. The end edge of one end 14a of the outflow side bushing 14 is abutted against the protrusion 64 formed on the bearing block 60 from the opposite side of the side that engages with the inflow side bushing 13, and the outflow side bushing 14 is engaged with the large diameter cylindrical portion 63b of the bearing block 60 to ensure coaxiality with the inflow side block 50 and the bearing block 60.

[0050] When the outflow side block 70 and the outflow side bushing 14 are coaxially joined, in the illustrated example, the end 70a of the outflow side block 70 opposite to the outflow side bushing 14 is formed into a cylindrical shape. Simultaneously, on the end 70a of the outflow side block 70 opposite to the outflow side bushing 14, the large-diameter cylindrical portion 71, whose outer diameter can be inserted into the cylindrical end 14b of the outflow side bushing 14, is formed with a stepped portion 72 to reduce the diameter of the end 70a. With this structure, by abutting the stepped portion 72 against the cylindrical end 14b of the outflow side bushing 14 and joining it with the large-diameter cylindrical portion 71 of the outflow side block 70, the coaxiality between the outflow side block 70 and the outflow side bushing 14 is ensured.

[0051] Furthermore, at one end 70a of the larger diameter cylindrical portion 71, the smaller diameter cylindrical portion 73, which is continuous with the larger diameter cylindrical portion 71 and whose outer diameter can be inserted into the bushing 42 of the solenoid 40, is formed with a stepped portion 74 to reduce the diameter at the aforementioned end 70a. Moreover, the bushing 42 of the solenoid 40 is coaxially inserted into the second shaft hole 66 of the bearing block 60 and the smaller diameter cylindrical portion 73 of the outflow side block 70. This structure ensures the coaxiality of the outflow side block 70 and the bearing block 60. A sealing member 46 is installed between the second shaft hole 66 and the bushing 42 to prevent gaseous fuel from flowing out of the flow path FP. Additionally, a buffer member 75 is provided on the end face of the smaller diameter cylindrical portion 73 to mitigate the impact and noise during collisions with the adjacent plunger member 22.

[0052] On the other hand, a first through hole 76, a second through hole 77, a third through hole 78, and a fourth through hole 79, which are interconnected, are formed on the outflow side block 70 as part of the flow path FP for gaseous fuel flow. The first through hole 76, the second through hole 77, the third through hole 78, and the fourth through hole 79 are coaxially overlapped in this order and formed to penetrate the outflow side block 70. The first through hole 76 is open at one end 70a of the outflow side block 70, and the fourth through hole 79 is open at the other end 70b of the outflow block 70 (the other end 10b of the main body 10). The second through hole 77 includes a guide hole 771 and a passage 772 formed on the outer periphery of the guide hole 771 for gaseous fuel to pass through. A valve seat member 81 constituting the valve seat part 80 is installed in the third through hole 78. The valve seat member 81 is held in place by an annular fixing member 83 fixed to the fourth through hole 79 so that it cannot be detached. However, the details of the valve seat part 80 will be described later. The first through hole 76, the second through hole 77, the third through hole 78 and the fourth through hole 79 are formed as through holes for the valve shaft portion 20 to be inserted into the interior of the main body portion 10 along the axial direction. The area around the inserted valve shaft portion 20 is formed as part of a flow path FP for the flow of gaseous fuel.

[0053] Reference Figure 4 The path for air to enter the interior of the main body 10 will be explained. The inflow side block 50 is provided with a vent 55 at one end 50a, which is connected to the receiving part 30, so that air can flow into the interior of the receiving part 30 from the vent 55.

[0054] Furthermore, a through hole 69 is formed in the bearing block 60, extending from one end 60a to the other end 60b. The through hole 69 connects the space 41 within the main body 10, which houses the solenoid 40, to the housing 30, and is configured such that atmospheric air can flow into the interior of the space 41 through the housing 30. Additionally, the through hole 69 can also be used as a path for wiring the solenoid 40.

[0055] <Valve Structure of Injector 1>

[0056] The valve structure of the injector 1 will be described below. This valve structure is an on / off valve that allows the valve shaft portion 20 to move forward and backward relative to the valve seat member 81 of the valve seat portion 80, switching between a state in which the valve core 24 of the valve shaft portion 20 is seated and the flow path FP is blocked (closed valve state) and a state in which the valve core 24 of the valve shaft portion 20 is unseaten and the flow path FP is released (open valve state).

[0057] The base end member 21 of the valve shaft portion 20 has a flange portion 211 protruding circumferentially on the circumferential surface of one end 21a for receiving a spring 31. The spring 31 is recessed between the lower surface of the flange portion 211 and the upper surface of the bearing block 60. Furthermore, a connecting hole 212 for connecting to the plunger member 22 is recessed along the axis from the end face of the other end 21b to the end 21a side. On the other hand, an annular groove 213 is formed along the inner circumferential direction on the circumferential surface of the other end 21b side. A sealing member 214, made of a material such as silicone rubber, with excellent airtightness and sliding properties, and a ring member 215, made of a material such as fluororesin, with excellent lubricity, are provided in the annular groove 213. The sealing member 214 and the ring member 215 contact the inner circumferential surface of the first shaft hole 65 of the bearing block 60, so that the other end 21b side of the base end member 21 is airtightly and slidably inserted into the first shaft hole 65 of the bearing block 60. With this structure, the end face of the other end 21b of the base end member 21 facing the bearing block 60 of the passage 67 functions as the pressure-bearing part 25 of the face that bears the pressure of the gaseous fuel introduced into the passage 67 in the backward direction.

[0058] The plunger member 22 of the valve shaft portion 20 has a connecting rod 221 formed at one end 22a with a stepped portion 222, the outer diameter of which can be inserted into the connecting hole 212 of the base end member 21. Furthermore, as shown, the plunger member 22 has a recessed insertion hole 223 and a connecting hole 224 arranged to align their axes. The insertion hole 223 is formed from the other end 22b of the plunger member 22 toward one end 22a. The diameter of the connecting hole 224 is smaller than that of the insertion hole 223. The connecting hole 224 is further formed from the end of the insertion hole 223 toward one end 22a and is used for connection with the front end member 23. Furthermore, in the plunger member 22, by forming a passage 225 that connects the end face of one end 22a of the stepped portion 222 with the through hole 223, the passage 225 and the through hole 223 are formed as part of a flow path FP for gaseous fuel flow.

[0059] The front end member 23 of the valve shaft portion 20 has a connecting rod 231 formed at one end 23a with a reduced diameter at that end 23a. The outer diameter of the connecting rod 231 can be inserted into the connecting hole 224 of the plunger member 22. Furthermore, the front end member 23 has an umbrella-shaped valve core 24 at its front end, formed with a larger diameter at the other end 23b and having an inclined surface 24a. On the other hand, a sliding portion 232 is formed at the axial middle portion 23c of the front end member 23. The diameter of the sliding portion 232 is slightly larger than the diameter of the connecting rod 231. The sliding portion 232 is configured to slide through a guide hole 771 formed in the second through hole 77 of the outflow side block 70. With this structure, together with the pressure portion 25 of the base end member 21, which slides hermetically relative to the first shaft hole 65 of the bearing block 60, axial movement can be guided at two locations, thus allowing the valve shaft portion 20 to move in a stable posture.

[0060] The valve seat portion 80 includes an annular valve seat member 81 with a valve hole 82 at its center and a fixing member 83, and is formed of an elastic material such as rubber or synthetic resin. In the illustrated injector 1, the valve hole 82 serves as the outlet 12 for gaseous fuel. The valve hole 82 of the valve seat member 81 forms part of the flow path FP for gaseous fuel flow. An annular groove 84 is formed on the outer peripheral surface of the valve seat member 81, and a sealing member 85 is provided in the annular groove 84. The sealing member 85 allows the valve seat member 81 to be airtightly mounted in the third through hole 78, except for the valve hole 82. The valve hole 82 has a larger diameter at one end 82a and the other end 82b, while the axial middle portion 82c becomes a smaller diameter throttling portion. The inner peripheral edge of the other end 82b of the valve hole 82 is rounded and is configured such that the inclined surface 24a of the valve core 24 can contact and separate from the inner peripheral edge. With this structure, a portion of the inclined surface 24a of the valve core 24 (the inner side of the contact diameter with the inner periphery of the valve hole 82) is configured as a pressure-bearing portion 26, which serves as a surface that bears the pressure of the gaseous fuel introduced into the valve hole 82 in the forward direction.

[0061] <Action of Injector 1>

[0062] The operation of injector 1 will be explained below.

[0063] The solenoid 40 of the drive valve shaft 20 is disposed along the inner circumferential surface of the outflow side bushing 14. More specifically, the solenoid 40 is disposed within a space 41 divided by the bearing block 60, the outflow side block 70, and the outflow side bushing 14, and has a bushing 42, an electromagnetic coil 43, a plunger 44, and a core 45. The plunger 44 is formed by the plunger member 22 of the valve shaft 20. The core 45 is formed by the small-diameter cylindrical portion 73 of the outflow side block 70. The electromagnetic coil 43 is disposed on the outer side of the bushing 42, and the plunger 44 and the core 45 are disposed on the inner circumferential side of the bushing 42.

[0064] Injector 1 is a normally closed injector. Therefore, when the solenoid 40 is de-energized, the elasticity of the retracted spring 31 applies force to the valve core 24 in the backward direction, forming a closed valve state where it sits on the valve seat member 81 of the valve seat portion 80. The solenoid 40 operates based on the flow rate required downstream, for example, by current supplied from a control device such as an on-board ECU. When the solenoid 40 is energized, the plunger 44 is attracted by the core 45 magnetized by the electromagnetic coil 43 and moves in the forward direction. The valve core 24 of the valve shaft portion 20 moves away from the valve seat member 81 of the valve seat portion 80, releasing the flow path FP to allow fluid to flow out. Then, when the solenoid 40 is de-energized again, the elasticity of the spring 31 applies force to the valve core 24 in the backward direction, causing the valve core 24 of the valve shaft portion 20 to sit on the valve seat member 81 of the valve seat portion 80, blocking the flow path FP to stop the flow of fluid.

[0065] A first shaft hole 65 is formed between the passage 67 and the receiving portion 30, and the pressure-bearing portion 25 of the base end member 21 of the valve shaft portion 20 can slide airtightly in the first shaft hole 65. The pressure inside the receiving portion 30, which is in communication with the atmosphere, is equal to the atmospheric pressure. On the other hand, the pressure in the flow path FP (the passage 67 portion) for the flow of gaseous fuel becomes relatively high due to the pressure of the gaseous fuel. As a result, the pressure in the flow path FP (the passage 67 portion) acts on the pressure-bearing portion 25 of the base end member 21 sliding in the first shaft hole 65, and generates a force that presses the base end member 21 in the backward direction.

[0066] Therefore, when the injector 1 operates, the pressure-bearing part 26, which acts as a surface that bears the pressure of the gaseous fuel introduced into the valve orifice 82 through the flow path FP in the forward direction, generates a force that moves the valve core 24 in the forward direction. Figure 5 (As shown by the downward-pointing black arrow), on the other hand, the pressure-bearing part 25, which acts as the surface bearing the pressure of the gaseous fuel introduced into the passage 67 in the backward direction, generates a force that causes the valve core 24 to move in the backward direction. Figure 5 (The upward-pointing black arrow is shown). Therefore, considering the force that moves the valve core 24 in the backward direction, the elasticity of the spring 31 can be set to a correspondingly weaker degree. Compared with the existing example where the pressure of the introduced gaseous fuel only acts in the valve core's opening direction, the valve core 24 can be easily opened even when the pressure within the main body 10 is low. Furthermore, there is no need to increase the electromagnetic attraction of the solenoid 40, thus avoiding various problems caused by increasing the electromagnetic attraction of the solenoid.

[0067] At this time, the surface of the pressure-receiving part 26 of the valve core 24 that bears the pressure of the gaseous fuel introduced into the valve orifice 82 in the forward direction and the surface of the pressure-receiving part 25 that bears the pressure of the gaseous fuel introduced into the passage 67 in the backward direction are configured such that their respective projected areas are approximately projected onto a plane orthogonal to the axial direction (projection plane). The "projected area" referred to here is the area when these surfaces are projected perpendicularly onto the projection plane, i.e., the area of ​​the orthographic projection. Therefore, the force of the gaseous fuel pressure pressing against the pressure-receiving part 26 in the forward direction and the force of the gaseous fuel pressure pressing against the pressure-receiving part 25 in the backward direction can be balanced, thereby minimizing the influence of the supply pressure supplied to the valve core 24. Therefore, compared to the conventional example, the valve core 24 can be opened more reliably and more easily.

[0068] Additionally, the illustrated injector 1 includes an adjusting spring 91, which applies force to the base-side member 21 in the forward direction to adjust the spring load of the spring 31. The adjusting spring 91 is disposed between a receiving member 93 and the base-side member 21. The receiving member 93 is located within the receiving portion 30, closer to the inlet 11 than the spring 31, and is axially movable via a retractable rod 92. The rod 92 is configured to move under the pressure of the gaseous fuel supplied from the inlet 11, compressing the adjusting spring 91. Thus, by providing the adjusting spring 91, fluctuations in the spring load caused by individual differences in the spring 31 can be absorbed; however, the adjusting spring 91 can also be omitted.

[0069] Figure 9 This is an enlarged cross-sectional view of the main part of the injector 2, which is a different embodiment of the present invention. The injector 2 described above differs only in the structure of the pressure-receiving part 25; otherwise, it has the same structure as the injector 1. Therefore, the same reference numerals are used for the same components, and their descriptions are omitted. That is, in the injector 1, the pressure-receiving part 25 is provided on the end face of the other end 21b side of the base end member 21, but in the injector 2, the pressure-receiving part 25 is provided in the middle part 22c of the plunger member 22. Even with the above configuration, the function of the pressure-receiving part 25 does not change; therefore, it can be appropriately modified according to the actual needs of design and manufacturing.

[0070] Those skilled in the art can readily make various modifications to the above exemplary embodiments without substantially departing from the new teachings and beneficial effects of the present invention, and all such modifications are included within the protection scope of the present invention.

[0071] Symbol Explanation

[0072] 1. Injector; 2. Injector; 10. Main body section; 10a One end; 10b The other end; 11. Inlet / Outlet; 12. Outlet; 13. Inflow side bushing; 13a One end; 13b The other end; 14. Outflow side bushing; 14a One end; 14b The other end; 20 Valve shaft section; 20a base; 20b Front end; 21. Base end side member; 21a One end; 21b The other end; 211 Flange portion; 212 Connecting hole; 213 Annular groove; 214 Sealing components; 215 Ring components; 22. Plunger components; 22a One end; 22b The other end; 22c Middle section; 221 Connecting rod; 222 Step section; 223 Through hole; 224 Connecting holes; 225 access; 23. Front-end side components; 23a One end; 23b The other end; 23c Middle part; 231 Connecting rod; 232 Sliding part; 24 Valve core; 24a Inclined surface; 25. Pressure-bearing part; 26. Pressure-bearing part; 30. Containment Department; 31. Spring; 40 Solenoid; 41. Space; 42. Bushing; 43. Electromagnetic coil; 44. Plunger; 45 cores; 46. ​​Sealing components; 50 Flow into the side block; 50a at one end; 50b The other end; 50c perimeter; 51 branching paths; 52. Opening; 53. The remainder; 54. Gap; 55 Vent; 66 Bearing blocks; 60a one end; 60b The other end; 60c Perimeter; 61. Small-diameter cylindrical section; 62. Step section; 63a Large-diameter cylindrical section; 63b: Large-diameter cylindrical portion; 64. Protruding part; 65 First shaft hole; 66 Second shaft hole; 67 access; 68. Gap; 69 Through holes; 70. Outflowing side block; 70a, one end; 70b The other end; 71. Large-diameter cylindrical section; 72. Step section; 73. Small-diameter cylindrical section; 74. Step section; 75. Buffer components; 76 First through hole; 77 Second through hole; 771 Guide hole; 772 access; 78 Third through hole; 79 Fourth through hole; 80 Valve seat section; 81 Valve seat component; 82 Valve hole; 82a One end; 82b The other end; 82c Middle section; 83. Fixed components; 84. Annular groove; 85 Sealing components; 91 Adjusting spring; 92 strokes; 93. Supporting components; FP flow path.

Claims

1. An injector, which is an electromagnetically driven injector for injecting gaseous fuel into the cylinder of an engine, characterized in that, include: The main body has at least a portion of a flow path for the gaseous fuel supplied from the inlet to flow axially toward the outlet side; A valve shaft portion, wherein the valve shaft portion is configured to move axially within the body portion, and a valve core for opening and closing the outlet is provided at the front end portion; A spring that applies force to the valve shaft in the retracting direction to close the outlet valve; as well as A solenoid, which elastically drives the valve shaft in the forward direction against the spring, thereby opening the outlet valve. The valve shaft includes a pressure-bearing part, which bears the pressure of the gaseous fuel flowing in the flow path in the retracting direction.

2. The injector as claimed in claim 1, characterized in that, The main body includes: An inflow side block, wherein the inflow side block is formed with the inlet; A bearing block in which a first shaft hole and a second shaft hole communicating with the flow path are formed together with a portion of the flow path, the first shaft hole being open at one end and the second shaft hole being open at the other end; An inflow-side bushing that retains the inflow-side block, which is coaxially engaged with the bearing block, and forms part of the flow path between the inflow-side block and the bearing block; Outflow side block, wherein the outflow side block forms the outflow outlet; and The outflow side bushing holds the outflow side block, the inflow side block, and the bearing block coaxially.

3. The injector as claimed in claim 2, characterized in that, The valve shaft portion includes: The base end side member has a flange portion at one end, which supports the spring between itself and the bearing block. The other end of the base end side member is airtight and slidably inserted into the first shaft hole of the bearing block. A plunger assembly having a portion of the flow path axially connected from one end to the other; and The front-end component has the valve core disposed at its front end. The base end member, the plunger member, and the front end member are coaxially joined, and the end face of the other end of the base end member functions as the pressure-bearing part.

4. The injector as claimed in claim 2, characterized in that, In the flow path side block, a plurality of branched flow paths extending radially outward are formed as part of the flow path and communicate with the flow inlet. The portion of the bearing block side, including at least a portion of the opening of the branched flow path, is formed as a small diameter, thereby forming a portion of the flow path communicating with the branched flow path between the circumferential surface of the inflow side block and the inflow side bushing.

5. The injector as claimed in claim 2, characterized in that, In the bearing block, a plurality of passages extending radially outward are formed as part of the flow path and communicate with the second shaft hole. The portion of the inflow side block, including at least a portion of the opening of the passage, is formed as a small diameter, thereby forming a portion of the flow path communicating with the passage between the circumferential surface of the bearing block and the inflow side bushing.

6. The injector as claimed in claim 3, characterized in that, The solenoid is disposed along the inner circumferential surface of the outflow side bushing, and the plunger component of the valve shaft is disposed on the inner circumferential side of the solenoid.

7. The injector as claimed in any one of claims 1 to 6, characterized in that, The projected areas of the valve core surface that bears the pressure of the gaseous fuel in the forward direction and the pressure-bearing part surface that bears the pressure of the gaseous fuel in the backward direction are approximately the same when projected onto a plane orthogonal to the axial direction.

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