INJECTOR

Abstract

The present invention relates to an injector comprising the following parts: a housing; an electromagnetic generating element housed in the housing and configured such that a coil is wound around the outer circumferential surface of the coil former to generate an electromagnetic field when current is applied; a core inserted into the end section of the coil former on the fuel rail side to form a magnetic circuit generated by the electromagnetic generating element using an electromagnetic field; a guide tube inserted into the end section of the coil former on the motor side to form a magnetic circuit in conjunction with the core;a molded part designed to surround the electromagnetic generating element and the outer circumferential surface of the core to prevent the ingress of moisture, and to be injected into a space between the inner circumferential surface of the coil former and the outer circumferential surface of the core to seal the gap between the electromagnetic generating element and the core, and a cover connected to and provided with the outer circumferential surface of the core to form a magnetic circuit together with the core.

Description

[Technical area of ​​the invention]

[0001] The present invention relates to an injector, specifically an injector that injects and supplies the fuel flowing in from a fuel rail into the combustion chamber of an engine. [Technical background of the invention]

[0002] An electromagnetically actuated valve in the form of an injector for a fuel injection system of a conventional internal combustion engine comprises an almost tubular core surrounded by a magnetic coil, which serves as the inner pole and partially as the fuel channel. The magnetic coil is completely enclosed circumferentially by, for example, a ferromagnetic outer valve casing (housing), which is thus formed in a stepped sleeve and serves as the outer pole to a component of the external magnetic circuit. The magnetic coil, the core, and the valve casing (housing) form an electrically excited actuating element.

[0003] While the solenoid coil, with its winding filled into the coil body, surrounds the valve sleeve (guide tube) externally, the core is inserted into the inner opening of the valve sleeve (guide tube), which extends concentrically to the valve's longitudinal axis. The valve sleeve is elongated and has a thin wall. The opening serves as a guide for the axially movable valve needle, particularly along the valve's longitudinal axis. The valve sleeve extends axially, for example, over half the total axial length of a fuel injector.

[0004] In addition to the core and the valve needle (needle shaft), a valve seat is arranged in the opening and is attached to the valve sleeve (guide tube), for example, by an overlapping weld. The valve seat has a solid valve seat surface. The valve needle (needle shaft) is formed, for example, by a tubular armature, a tubular needle section, and a spherical valve closure body, the latter being connected to the needle section, for example, by an overlapping weld. Downstream of the valve seat body, on the end section surface, an injection plate, for example, in the form of a pot, is arranged, the circumferentially curved support edge of which points upwards in the opposite direction of the flow. The solid connection between the valve seat body and the injection plate is achieved, for example, by an annularly sealed, overlapping weld.Since one or more transverse openings are arranged in the needle section of the valve needle, fuel flowing through the armature in the inner longitudinal bore can be released to the outside and flow along the valve closure body, for example a flattened surface, to the valve seat surface.

[0005] The injection valve is actuated electromagnetically in a known manner. An electromagnetic circuit, comprising a magnetic core, an inner core, an outer valve casing, and an armature, serves to axially move the valve needle (needle shaft) and to open or close the orifice against a spring force of the return spring acting on the valve needle. An end section of the armature, separate from the valve body, faces the core. Instead of the core, a cover element, for example, can be provided as the inner pole, and this cover element closes the magnetic circuit.

[0006] The spherical valve closure body interacts with a valve seat surface of a valve seat body that tapers in a frustoconical shape in the flow direction. Within the valve seat body, the valve seat surface is formed axially on the downstream side of the guide opening. The injection orifice plate comprises four nozzles, formed by at least one of, for example, erosion, laser drilling, or punching.

[0007] The insertion depth of the core in the injector is crucial, particularly for the timing of the valve needle. One end-section position of the valve needle is determined by the valve body contacting the valve seat surface when the solenoid coil is not energized. Another end-section position is determined by an armature contacting an end section of the downstream core when the solenoid coil is energized. The timing is set by axially moving a core, which is then connected to the valve sleeve at a predetermined position.

[0008] An adjusting element in the form of an adjusting sleeve is inserted next to the return spring into the flow bore of the core, which extends concentrically to the valve's longitudinal axis and serves to supply fuel towards the valve seat. The adjusting sleeve (tube) serves to regulate the spring preload of the return spring, which is in contact with it. The return spring is supported on the valve needle within the armature area by the opposing sides of the sleeve, with the dynamic injection quantity also being adjusted by the adjusting sleeve. A fuel filter is located in the valve sleeve above the adjusting sleeve.

[0009] The inlet end section of the valve is formed by a metallic fuel inlet sleeve, which is surrounded by an injection-molded plastic part that stabilizes, protects, and encloses it. A flow bore extending concentrically to the valve's longitudinal axis in a tube of the fuel inlet sleeve (extension tube) serves to supply fuel. The injection-molded plastic part is shaped, for example, so that the plastic directly surrounds the valve sleeve and parts of the valve body.

[0010] However, since the environment of a conventional adjustment valve (injector) is one where the injector is repeatedly exposed to high (temperature) and low temperatures during engine operation and is constantly exposed to moisture, there is a high probability that water has entered the interior of the injector, and if the injector comes into contact with water, insulation failure due to a short circuit can occur.

[0011] This means that in the case of the conventional injector, as in Fig.As shown in Figure 1, since both axially oriented end sections of the coil former are in contact with the core and the housing, the molded part was not injected into the inner circumferential surface of the coil. Therefore, at high temperature, low temperature, or high water content, a tiny space forms between the coil and the core or between the core and the housing, with water flowing into spaces (1, 2) (in the direction shown by the arrow), and when moisture reaches terminal (3), to which the current is applied through the resin-free space within the injector, a short-circuit fault has occurred.

[0012] Therefore, it is necessary to develop a structure for a plastic injection molded part (molded part) that can block the inflow of moisture under strict conditions.

[0013] The KR 2013-0105832 A describes an injection valve.

[0014] DE 103 32 348 A1 describes a fuel injection valve.

[0015] The JP 2018 - 189 002 A describes a fuel injection valve.

[0016] DE 100 21 072 A1 describes a fuel injection valve. [Content of the invention][Purpose of the invention]

[0017] The present invention is made to improve upon the problems of the conventional injector described above, and it is an objective of the present invention to offer an injector that is able to prevent the inflow of moisture regardless of the ambient conditions.

[0018] To achieve the above objective, an injector that supplies fuel flowing from a fuel rail to the engine, according to the present invention, is characterized in that the injector comprises the following parts: a housing; an electromagnetic generating element housed in the housing and configured such that a coil is wound around the outer circumferential surface of the coil body to generate an electromagnetic field when current is applied; a core inserted into the end section of the coil body on the fuel rail side to form a magnetic circuit generated by the electromagnetic generating element using an electromagnetic field; a guide tube inserted into the end section of the coil body on the engine side to form a magnetic circuit in conjunction with the core;a molded part designed to surround the electromagnetic generating element and the outer circumferential surface of the core to prevent the ingress of moisture, and to be injected into a space between the inner circumferential surface of the coil former and the outer circumferential surface of the core to seal the gap between the electromagnetic generating element and the core, and a cover connected to and provided with the outer circumferential surface of the core to form a magnetic circuit together with the core.

[0019] Furthermore, it is also possible that the core comprises the following parts: an insert part that is inserted into the inner circumferential surface of the coil body to form a magnetic circuit in conjunction with the electromagnetic generating part; a connecting part of the molded part that is connected to an end section of the insert part on the fuel rail side and is designed such that the molded part is injected into the connecting part, since it has an outer diameter that is smaller than an outer diameter of the insert part; and a threshold connecting part that is connected to an end section of the connecting part of the molded part on the fuel rail side and supports the cover, being received into the coil body, since it has an outer diameter that is larger than an outer diameter of the insert part.

[0020] Furthermore, it is also possible that the coil body comprises the following parts: a coil main body on which the coil is wound and on whose inner circumferential surface the core and the guide tube are inserted, and a first injection part on which a first injection opening of the molded part is formed to prevent the inflow of moisture, since the molded part is injected by being connected to an end section of the coil main body on the side of the fuel rail and a core receiving groove is formed along the circumferential direction to receive the sill connection part.

[0021] Furthermore, although the coil body is connected to an end section of the coil main body on the motor side and is supported by contact with the housing, it is also possible that the coil body includes a second injection part on which a second injection opening of the molded part is formed to prevent the inflow of moisture, as the molded part is injected.

[0022] At the same time, although the cover is designed to have a diameter larger than the diameter of the threshold connection part in order to cover the threshold connection part in the axial direction, it is also possible that an injection groove is formed to allow the first injection opening of the molded part to be freely exposed, and that a cutting part is formed to enlarge an injection chamber of the molded part.

[0023] Furthermore, it is also possible that the molded part comprises the following parts: a main body of the molded part, which is received into the housing and is configured to surround the outer circumferential surface of the electromagnetic generating part, the outer circumferential surface of the threshold connecting part, and the outer circumferential surface of the cover; a sealing part of the housing, which is configured to extend from an inner circumferential surface of the main body of the molded part to seal an end section of the housing on the fuel rail side; and a first sealing part, which is configured to extend from the inner circumferential surface of the main body of the molded part and pass through the first injection opening of the molded part and surround the outer circumferential surface of the connecting part of the molded part.

[0024] Furthermore, it is also possible that the molded part includes a second sealing part, which is designed to extend from the main body of the molded part and pass through the second injection opening of the molded part and surround the inner circumferential surface of the coil body.

[0025] Furthermore, it is also possible that the guide tube comprises the following parts: a main tube body designed for insertion into the coil body, and a receiving part for the molded part, which is formed on the outer circumferential surface of the main tube body and is shaped in a groove form along the circumferential direction to receive the molded part. [Effects of the invention]

[0026] As described above, according to the injection valve (injector) of the present invention, the housing is sealed and a space between the coil body and the core as well as a space between the coil body and the guide tube are sealed to prevent the inflow of moisture even in harsh environmental conditions, thereby preventing the occurrence of defects due to a short circuit. [Brief description of the invention]

[0027] They show: Fig. 1: A reference view showing the water flow paths with arrow symbols from a cross-section of a conventional injector. Fig. 2: a perspective view of an injector according to an embodiment of the present invention. Fig. 3: a cross-sectional view of Fig. 2. Fig.4: A perspective view of a core in an injector according to an embodiment of the present invention. Fig. 5: a cross-sectional view of Fig. 4. Fig. 6: a perspective view of an electromagnetic generating part in an injector according to an embodiment of the present invention. Fig. 7: A side view of an electromagnetic generating element in an injector according to an embodiment of the present invention. Fig. 8: A side view of a guide tube in an injector according to an embodiment of the present invention. Fig. 9: an enlarged partial view of Fig. 3. Fig. 10: a reference view showing only one molded part in Fig. 9 shows. Fig. 11: a perspective view of a cover in an injector according to an embodiment of the present invention. [Examples of the invention]

[0028] Preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0029] Referring to the Fig. 2 and Fig. 3 An injector according to the present invention is described in which an end section of the injector is axially connected on one side to a fuel rail (not shown in the drawings) and its end section is axially connected on another side to a motor (not shown in the drawings), wherein the fuel flowing in from the fuel rail (not shown in the drawings) is injected into the motor (not shown).

[0030] Furthermore, the injector comprises the following parts: a housing 100, an electromagnetic generating part 200, a core 300, a guide tube 400, a molded part 500, a cover 600, an extension tube 10, a power supply part 20, a tube 30, a return spring 40, an armature 50, a needle shaft 60, a ball 70, a valve seat 80 and a measuring orifice 90.

[0031] Simultaneously, the electromagnetic generating unit 200 is incorporated into the housing 100, into which the core 300 and the guide tube 400 are slidably connected, and the cover 600 is inserted into the outer circumferential surface of the core 300. Furthermore, an end section of the core 300 on the fuel rail side is inserted into the inner circumferential surface of the extension tube 10, and an end section of the core 300 on the motor side is inserted into the inner circumferential surface of the guide tube 400. Additionally, the tube 30 is inserted into the inner circumferential surface of the core 300, and the armature 50 is inserted into the inner circumferential surface of the guide tube 400. The return spring 40 is provided between the tube 30 and the armature 50.Furthermore, the needle shaft 60 is designed to be linearly movable through the armature 50, with one end section of the needle shaft 60 on the fuel rail side being supported by the return spring 40 and another end section on the engine side being designed to contact the ball 70. The ball 70 is also received in the valve seat 80, with the measuring orifice 90 being provided in the end section of the valve seat 80 on the engine side. In addition, the electromagnetic generating unit 200 is electrically connected to the power supply unit 20.

[0032] Furthermore, the molded part 500 is designed to surround the following parts: the extension tube 10, the power supply part 20, the housing 100, the electromagnetic generation part 200, the core 300, the guide tube 400 and the cover 600.

[0033] Referring to Fig.3 According to one embodiment of the present invention, the injector comprises the following parts: the housing 100, the electromagnetic generating part 200, the core 300, the guide tube 400, the molded part 500 and the cover 600.

[0034] The housing 100 accommodates the electromagnetic generating element 200, the core 300, and the cover 600 within its interior, since its open end section on the fuel rail side is cylindrical, with the guide tube 400 inserted into its end section on the motor side. Simultaneously, its open end section on the fuel rail side is sealed by the molded part 500.

[0035] Referring to Fig.In sections 3 to 5, the core 300 is cylindrical and designed such that its end section on the fuel rail side is inserted into the extension tube 10 and its end section on the engine side is inserted into the electromagnetic generating unit 200. The core 300 also comprises the following parts: an insertion part 310, a connecting part of the molded part 320, a sill connection part 330, a cover connection part 340, a fuel inlet part 350, and a pipe connection part 360. Furthermore, the insertion part 310 has an outer diameter R1 that corresponds to the inner diameter of the electromagnetic generating unit 200, so that it can be inserted into the inner circumferential surface of the electromagnetic generating unit 200.The connecting part of the molded part 320 extends axially from the insert part 310, but the outer diameter R2 of the molded part 320 is smaller than the outer diameter R1 of the insert part 310 (R2 < R1). Furthermore, the threshold connection part 330 has an outer diameter R3 that is larger than the outer diameter R1 of the insert part 310 (R1 < R3), so that the threshold connection part 330 is well situated and supported on the electromagnetic generating part 200.The cover connecting part 340 is designed such that it has an outer diameter which corresponds to the inner diameter of the cover 600, since the cover 600 is connected to its outer circumferential surface, and the fuel inlet part 350 is designed such that it has an outer diameter which corresponds to the inner diameter of the extension pipe 10, since it is connected insertably into the extension pipe 10, and the pipe connecting part 360 is designed such that it has an outer diameter which corresponds to the inner diameter of the guide pipe 400, since it is connected insertably into the guide pipe 400.

[0036] Under references to Fig. 3, Fig. 6 and Fig.7 The electromagnetic generating part 200 is incorporated into the housing 100 and is designed so that the core 300 and the guide tube 400 are inserted, and comprises a coil former 210 and a coil 220. In addition, the coil 220 is wound on the outer circumferential surface of the coil former 210.

[0037] The coil body 210 comprises the following parts: a coil main body 211, a first injection part 212 and a second injection part 213. In addition, the coil main body 211 is cylindrical, so that the coil 220 is wound on its outer circumferential surface and thus the core 300 and the guide tube 400 are inserted into its inner circumferential surface.

[0038] The first injection part 212 is formed on an end section of the coil main body 211 on the fuel rail side and comprises first injection openings 212a of the molded part and a core receiving groove 212b. The core receiving groove 212b is formed in a groove shape such that it has an inner diameter corresponding to the outer diameter R3 of the threshold connection part 330, so that the threshold connection part 330 of the core 300 is properly seated. Furthermore, the first injection openings 212a of the molded part are designed to penetrate along the circumferential direction at a predetermined interval, so that the molded part 500 is injected into the inner circumferential surface of the coil main body 211. Therefore, the first injection openings 212a and the core receiving groove 212b are formed in a groove shape along the axial direction, with the first injection openings 212a being formed outside the radius of the core receiving groove 212b.Although in the present embodiment the first injection openings 212a of the molded part are formed at 90 degree intervals for 4 pieces along the circumferential direction, the present invention is not limited thereto.

[0039] The second injection element 213 is formed on the end section of the coil body 211 on the motor side and comprises second injection openings 213a and housing contact elements 213b. The housing contact elements 213b are designed to extend from the coil body 211 along the circumferential direction towards the motor. That is, a plurality of the housing contact elements 213b are designed along the circumferential direction to be in contact with the housing. Furthermore, second injection openings 213a are formed in a space surrounded by the coil body 211, the housing contact element 213b, and the housing 100. Although in the present embodiment the housing contact elements 213b are formed at 90-degree intervals of four along the circumferential direction, the present invention is not limited thereto.

[0040] Referring to Fig. 3 and Fig.The guide tube 400 is inserted into the electromagnetic generating part 200 and is formed in which the core 300 is inserted, and comprises a main tube body 410 and a receiving part of the molded part 420. The main tube body 410 is cylindrical so that it can be inserted into the housing 100 and the electromagnetic generating part 200. Furthermore, the receiving part of the molded part 420 is formed in a groove shape along the circumferential direction on the main tube body 410, and is inserted into the electromagnetic generating part 200. That is, a space for injecting the molded part 500 is formed between the inner circumferential surface of the coil main body 211 and the outer circumferential surface of the main tube body 410.

[0041] Referring to Fig.Figures 3 to 11 describe the molded part 500 as being designed such that a plastic resin material is injected into it by inset injection molding (using an inset injection molding process) and comprising a molded part main body 510, a housing sealing part 520, a first sealing part 530, and a second sealing part 540. The molded part main body 510 is received in the housing 100 and is designed to surround the outer circumferential surface of the electromagnetic generating part 200, the outer circumferential surface of the threshold connection part 330, and the outer circumferential surface of the cover 600. Furthermore, the housing sealing part 520 is connected to the molded part main body 510 and is designed to surround the outer circumferential surface of the housing 100.The first sealing element 530 extends from the inner circumferential surface of the main body of the molded part 510 and passes through the first injection opening 212a of the molded part, and is configured to surround the outer circumferential surface of the connecting part of the molded part 320. The second sealing element 540 extends from the main body of the molded part 510 and passes through the second injection opening 213a of the molded part, and is configured to surround the inner circumferential surface of the coil body 210 and the receiving part of the molded part 420.

[0042] That is, the several first sealing parts 530 are formed along the circumferential direction according to the shape of the first injection opening 212a of the molded part and are formed such that they have the same inner diameter R3 as the outer diameter of the clutch shoe 330, extending in the radial direction after extending towards the engine, and they are connected in the form of a ring according to the shape of the connecting part of the molded part 320.

[0043] At the same time, the second sealing parts 540 are designed such that the circumferential direction extends inwards in the radial direction according to the shape of the second injection opening 213a of the molded part and they extend along the inner circumferential surface of the coil body 210, and they are connected in a ring shape according to the shape of the receiving part 420 of the molded part.

[0044] The cover 600 is connected to an outer circumferential surface of the cover connection part 340 of the core 300 and a surface of the sill connection part 330 on the side of the fuel rail and comprises a cover main body 610, an injection groove 620 and a cutting part 630.The main cover body 610 is designed such that, although it has an outer diameter larger than the outer diameter R3 of the coupling stage 330 in order to cover the threshold connection part 330 in the axial direction, the injection groove 620 is designed such that it extends inwards in the radial direction from the main cover body 610 in accordance with the position of the first injection openings 212a of the molded part, in order to expose the first injection openings 212a of the molded part, and a step is formed in the main cover body 610 in a direction parallel to the axial direction in order to widen a space into which the molded part 500 is injected, and the separating part 630 is formed by cutting.

[0045] Referring to Fig.In paragraphs 2 to 11, the effect of the injector according to an embodiment of the present invention is described: the injector is improved such that the first injection openings 212a of the molded part and the second injection openings 213a of the molded part are provided on the coil body 210 so that the molded part 500 can be injected up to the inner circumferential surface of the coil body 210.

[0046] As in Fig.As shown in Figure 1, the molded part was not injected into the inner circumferential surface of the coil former because, in the case of a conventional injector, both end sections of the axially oriented coil former are in contact with the core and the housing. Therefore, at high temperature, low temperature, or high water content, a tiny space forms between the coil and the core or between the core and the housing, with water flowing into spaces (1 and 2) (in the direction shown by the arrow). If moisture reaches terminal (3), to which the current is applied through the resin-free space within the injector, a short-circuit fault occurs.

[0047] According to the present invention, however, the ingress of moisture can be prevented even under harsh environmental conditions, since a gap between the coil body 210 and the core 300 is sealed by the first sealing part 530 and a gap between the coil body 210 and the housing 100 is sealed by the second sealing part 540.

[0048] In the present invention, the connecting part of the molded part 320 and the receiving part of the molded part 420 are designed so that the molded part 500, which is injected into the first injection openings 212a and the second injection openings 213a of the molded part, fulfills a sufficient sealing function. That is, the molded part 500, which is injected into the first injection openings 212a and the second injection openings 213a of the molded part, is designed to completely surround the core 300 and the guide tube 400 by being injected along the connecting part of the molded part 320 and the receiving part of the molded part 420. As a result, a space between the inner circumferential surface of the coil former 210 and the core 300 and the guide tube 400 is completely sealed by the molded part 500.

[0049] Furthermore, the injection groove 620 and the cutting element 630 are incorporated into the cover 600 to enable efficient injection of the molded part 500. Since the molded part 500 is injected using the insert injection molding process, space is required to inject molding material into the first injection ports 212a of the molded part. Therefore, according to the present invention, access to the first injection ports 212a of the molded part is facilitated by the injection groove 620 and the cutting element 630.

[0050] Finally, the housing sealing element 520 is formed in the molded part 500 by increasing the molded part length to surround the outer circumferential surface of the housing 100. Conventionally, the open end section of the housing is designed to be exposed to the outside, and consequently, moisture can easily infiltrate through this open end section. However, since, according to the present invention, the open axially oriented end section of the housing 100 and the outer circumferential surface of the housing 100 are sealed by the housing sealing element 520, the infiltration of moisture can be further reduced.

[0051] Table 1 shows the results of the insulation performance test using a conventional injector. In this test (temperature shock via cold water), when the injector was exposed to 140 °C for 1 hour and then immersed for 5 minutes at a temperature of 0 °C to 4 °C, it is evident that all test samples exhibited poor insulation resistance (less than 10 MΩ) due to a short circuit.

[0052] Here, insulation resistance represents a measure of insulation performance. A high voltage is applied between the injector terminal and the metal part forming the injector body (housing, etc.), and a resistance value is obtained by measuring the current. If the resistance value is greater than 10 MΩ, this means that the current is barely flowing.

[0053] Furthermore, the insulation resistance has the ability to prevent current from flowing to components other than the injector coil. Therefore, if the insulation resistance value is low (less than 10 MΩ), it can be interpreted that, since current is flowing to other components, a short circuit to the engine through the injector body is possible, as the injector is installed in the engine. [Table 1] test items Sample number Before the test [MΩ] After the test [MΩ] Results Temperature shock from cold water 1 Normal (more than 10) 1,4 Bad 2 Normal (more than 10) 0,1 Bad 3 Normal (more than 10) 0,3 Bad 4 Normal (more than 10) 0,2 Bad 5 Normal (more than 10) 0,1 Bad 6 Normal (more than 10) 0,2 Bad

[0054] In contrast, in the case of the injector according to the present invention, as shown in Table 2, all conditions under which the reference values ​​of the insulation resistance of 10 [MΩ] or more are exceeded were met with temperature shock by cold water. [Table 2] test items Sample number Before the test [MΩ] After the test [MΩ] Results Thermal shock from cold water 1 Normal (more than 10) Normal (more than 10) Passed 2 Normal (more than 10) Normal (more than 10) Passed 3 Normal (more than 10) Normal (more than 10) Passed 4 Normal (more than 10) Normal (more than 10) Passed 5 Normal (more than 10) Normal (more than 10) Passed 6 Normal (more than 10) Normal (more than 10) Passed

[0055] Therefore, according to the present invention, it is possible to reduce the occurrence of defects due to a short circuit by preventing the inflow of moisture even under harsh environmental conditions.

[0056] Although the present invention is described in detail with reference to exemplary embodiments, it is understood that the invention is not limited to the disclosed exemplary embodiments and that it is apparent to the person skilled in the art that various changes and modifications can be made without deviating from the technical spirit of the present invention and from the equivalent scope of the claims set forth below.

[0057] All simple variations or modifications of the present invention shall be included within the scope of the present invention and the specific scope of protection of the present invention is clearly defined by the attached claims. [List of reference symbols] 100 cases 200 electromagnetic generating unit 210 coil formers 211 Coil body 212 first injection part 212a first injection opening of the molded part 213 second injection part 213a second injection port of the molded part 220 coil 300 core 310 Insert part 320 Connecting part of the molded part 330 Threshold connection part 400 guide tube 410 Main pipe body 420 Receiving part of the molded part 500 molded parts 510 Main body of the molded part 520 Sealing part of the housing 530 first sealing part 540 second sealing part 600 Coverage 610 Cover main body 620 Injection groove 630 Cutting part

Claims

[1] Injector that supplies fuel flowing in from a fuel rail to the engine, comprising the following parts: a case; an electromagnetic generating element housed within the casing and designed such that a coil is wound around the outer circumferential surface of the coil body to generate an electromagnetic field when current is applied; a core inserted into the end section of the coil body on the fuel rail side to form a magnetic circuit generated by the electromagnetic generating part using an electromagnetic field; a guide tube that is inserted into the end section of the coil body on the side of the motor to form a magnetic circuit in conjunction with the core; a molded part designed to surround the electromagnetic generating element and the outer circumferential surface of the core to prevent the ingress of moisture, and to be injected into a space between the inner circumferential surface of the coil former and the outer circumferential surface of the core to seal the gap between the electromagnetic generating element and the core, and a cover that is connected to the outer circumferential surface of the core and is designed to form a magnetic circuit together with the core, the core comprises the following parts: an insert part that is inserted into the inner circumferential surface of the coil body, a connecting part of the molded part which has an outer diameter that is smaller than an outer diameter of the insert part, and a sill connection part which has an outer diameter that is larger than the outer diameter of the insertion part. [2] Injector according to claim 1, wherein the insertion part forms a magnetic circuit in conjunction with the electromagnetic generating part; wherein the connecting part of the molded part is connected to an end section of the insertion part on the fuel rail side and is designed such that the molded part is injected into the connecting part, and wherein the sill connection part is connected to an end section of the connecting part of the molded part on the fuel rail side and supports the cover, being received into the coil body. [3] Injector according to claim 2, wherein the coil body comprises the following parts: a coil main body on which the coil is wound and on whose inner circumferential surface the core and the guide tube are inserted, and a first injection part in which a first injection opening of the molded part is formed to prevent the inflow of moisture, since the molded part is injected by being connected to an end section of the coil main body on the side of the fuel rail and a core receiving groove is formed along the circumferential direction to receive the threshold connecting part. [4] Injector according to claim 3, wherein the coil body comprises the following parts: a coil main body on which the coil is wound and on whose inner circumferential surface the core and the guide tube are inserted, and a first injection part in which a first injection opening of the molded part is formed to prevent the inflow of moisture, since the molded part is injected by being connected to an end section of the coil main body on the side of the fuel rail and a core receiving groove is formed along the circumferential direction to receive the threshold connecting part. [5] Injector according to claim 3, wherein the cover has a diameter larger than the diameter of the threshold connection part in order to cover the threshold connection part in the axial direction, however it is also possible to form an injection groove to allow the first injection opening of the molded part to be freely exposed, and to form a cutting part to enlarge an injection chamber of the molded part. [6] Injector according to claim 4, wherein the molded part comprises the following parts: a main body of the molded part which is incorporated into the housing and is designed to surround the outer circumferential surface of the electromagnetic generating part, the outer circumferential surface of the threshold connecting part and the outer circumferential surface of the cover; a sealing part of the housing, extending from an inner circumferential surface of the main body of the molded part to seal an end section of the housing on the fuel rail side, and a first sealing part which is designed to extend from the inner circumferential surface of the main body of the molded part and pass through the first injection opening of the molded part and surround the outer circumferential surface of the connecting part of the molded part. [7] Injector according to claim 6, wherein the molded part further comprises a second sealing part which is designed to extend from the main body of the molded part and pass through the second injection opening of the molded part and surround the inner circumferential surface of the coil body. [8] Injector according to claim 1, wherein the guide tube comprises the following parts: a main tube body designed for insertion into the coil body, and a receiving part of the molded part formed on the outer circumferential surface of the main tube body and provided in a groove shape along the circumferential direction to receive the molded part.

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