JP7134341B2 - fuel injector - Google Patents

Description

The present application relates to fuel injection valves.

2. Description of the Related Art As background art in this technical field, for example, a fuel injection valve described in Patent Document 1 is known. In Patent Document 1, an elastic portion is provided in an intermediate portion of a tubular body 36 that joins the armature 12 of the valve body and the valve portion 14 . A cylindrical body 36 shown in FIG. 5 is manufactured by rolling a flat plate.

In the developed view, the rectangular opening which is the elastic portion is formed longer in the axial direction (vertical direction in FIG. 5) than in the circumferential direction (horizontal direction in FIG. 5). In the developed view of the cylindrical body 36 in FIG. 5, if the portion where the openings are continuous in the circumferential direction is regarded as one layer, a cutout layer 20 in which the through holes and the cutouts are open, and a through layer 20 in which only the through holes are open. There are 19 They are arranged alternately in the axial direction, and the openings of the respective layers are formed circumferentially with a 1/2 pitch shift of the openings.

Therefore, the plate material portion between the openings of the layers is a circumferential plate portion (peripheral web) extending in the circumferential direction, and the layers are connected via the circumferential web.

With such a configuration, the load received by the valve portion 14 from the valve seat 8 immediately after the fuel injection valve collides with the valve to close is transmitted to the cylindrical body 36, and both ends of the circumferential web receive the load in the axial direction and undergo bending deformation. As a result, the tubular body 36 behaves like a compression spring and absorbs the impact load. This reduces operating noise.

JP-A-2-195084

The load that the valve portion 14 receives from the valve seat 8 immediately after the fuel injection valve is closed is transmitted to the cylindrical body 36 . As a result, when the peripheral web bends and deforms, the cylindrical body 36 has a C-shaped cross-section and is not point-symmetrical, so that the rigidity is unbalanced and the valve body falls in the direction of low rigidity. A phenomenon in the axial direction of the valve body is that it bends in a predetermined direction from the notch layer 20 with low rigidity of the cylindrical body 36 as a base point, and when the bending increases, the armature 12 and the inner peripheral surface of the holder 39 interfere with each other.

The cylindrical body 36 of Patent Document 1 has a plurality of notch layers 20, and the bending angle increases according to the number of layers. In addition, since the elastic portion is long in the axial direction and the cutout layer 20 extends to a relatively long position with respect to the armature 12, the amount of deflection of the armature 12 due to bending of the cutout layer 20 is relatively large. When the armature 12 swings greatly and interferes with the inner peripheral surface of the holder 39, the frictional resistance increases and the elastic deformation of the cylindrical body 36 is significantly hindered. As a result, the impact load is not sufficiently absorbed when the valve is closed, and the operating noise is not reduced much.

A similar problem occurs when the valve is opened, and the load received by the armature 12 immediately after the valve body collides with the core 1 is transmitted to the cylindrical body 36 and bends starting from the cutout layer 20 . Due to this bending, the valve portion 14 swings greatly, and the resulting interference with the inner circumference of the valve seat 8 increases the frictional resistance, which significantly hinders the elastic deformation of the cylindrical body. As a result, the absorption of the collision load when the valve is opened becomes insufficient, and the operating noise is not significantly reduced.

A particular problem is when the armature sliding part clearance or the valve part sliding clearance is small, there is little margin for interference as mentioned above, and strong interference with mating parts occurs due to vibration, reducing operating noise. It means that it will not be done.

This application has been made in view of such circumstances, and by optimizing the size and position of the elastic portion of the cylindrical body, it is possible to avoid interference with the mating parts of the armature and the valve portion when the valve is closed and opened. Or, it is intended to suppress the operation noise when the valve is opened and closed by adjusting it appropriately.

The fuel injection valve disclosed in the present application is
A valve body, which has an armature made of a magnetic material, a tubular body coupled to the armature, and a valve portion coupled to the tubular body, slides axially in the holder due to the magnetic attraction force of the solenoid device. The cylindrical body has a C-shaped cross section, and is provided with an elastic portion in which an opening shorter in the axial direction than in the circumferential direction is formed in the axially intermediate portion of the cylindrical body. The clearance with the armature sliding portion is set larger than the clearance between the valve portion and the valve portion sliding portion that serves as a guide during sliding, and the distance from the elastic portion to the armature sliding portion is set to be elastic. is longer than the distance from the part to the valve part sliding part.

According to the fuel injection valve disclosed in the present application, by setting the clearance of the armature sliding portion to be larger than the clearance of the valve portion sliding portion, the degree of margin for interference due to the tilting of the armature when the valve is closed is reduced to It is made larger than the margin for tilting of the valve body when the valve is opened. Furthermore, by making the distance from the elastic portion to the armature sliding portion longer than the distance from the elastic portion to the valve portion sliding portion, the deflection amount of the armature when opening and closing the valve is made larger than the deflection amount of the valve body. there is With this configuration, when the valve is opened and closed, the frictional resistance caused by interference with the armature or the valve portion will not impede the elastic deformation of the cylindrical body as much as possible. It was realized.

1 is a cross-sectional view showing the configuration of a fuel injection valve according to Embodiment 1; FIG. FIG. 2 is an enlarged view of a portion A of the fuel injection valve of FIG. 1; It is a figure which shows an example before the roll processing of the cylindrical body of FIG. FIG. 4 is a cross-sectional view taken along the line XX when FIG. 3 is rolled; FIG. 4 is a view showing an example of a tubular body having a penetrating layer before being rolled. FIG. 10 is a view showing an example of the cylindrical body before rolling when welding the armature, the cylindrical body, and the valve portion;

Preferred embodiments of a power control device according to the present application will be described below with reference to the drawings. The same reference numerals are assigned to the same contents and corresponding parts, and detailed description thereof will be omitted. In the following embodiments as well, redundant descriptions of the configurations denoted by the same reference numerals will be omitted.

Embodiment 1.
1 is a cross-sectional view showing the configuration of a fuel injection valve 1 according to Embodiment 1, and FIG. 2 is an enlarged view of part A in FIG. 3 is a developed view of the tubular body 62 shown in FIG.

In FIG. 1, the main components of a fuel injection valve 1 are: a solenoid device 2 which is supplied with an electric current from the outside to generate a magnetic attraction force; A spring 4 arranged inside, a holder 5 arranged on the inner circumference of the solenoid device 2, a valve body 6 arranged inside the holder 5, an armature 61 which is a constituent part of the valve body 6 and made of a magnetic material, and the armature 61 It consists of a coupled tubular body 62 , a valve portion 63 coupled to the tubular body 62 , a valve seat 7 in contact with the valve portion 63 , and a plate 8 coupled to the valve seat 7 .

Next, the valve body 6 will be explained. After the armature 61 is press-fitted into the cylindrical body 62, it is joined by welding. The valve portion 63 is also welded to the tubular body 62 . The core 3 is welded after being press-fitted into the holder 5 . The valve seat 7 is coupled with a plate 8 positioned downstream, and the valve seat 7 is fixed by welding the plate 8 and the holder 5 together.

Next, operation of the valve body 6 will be described. When the solenoid device 2 is energized and a magnetic field is generated, an electromagnetic force acts on the armature 61 and the valve body 6 is attracted to the core 3 side. As shown in FIG. 2, the valve body 6 moves in the axial direction while being guided by the armature sliding portion 61a and the valve portion sliding portion 63a. In this embodiment, the outer peripheral portion of the armature 61 facing the inner periphery (holder inner peripheral surface) 5a of the holder 5 serves as an armature sliding portion 61a. The outer peripheral portion of the valve portion 63 facing the inner periphery of the valve seat 7 (valve seat inner peripheral surface 7a) serves as a valve portion sliding portion 63a. The axial movement limit of the valve body 6 toward the core is a position where the armature 61 contacts the core 3 .

After the energization of the solenoid device 2 is stopped, the valve body 6 is guided by the valve portion sliding portion 63a by the elastic force of the spring 4 provided inside the core 3 and moves in the axial direction. The axial movement limit of the valve body 6 away from the core 3 is the position where the valve portion 63 is seated on the valve seat 7 .

The cylindrical body 62 has a C-shaped cross section obtained by rolling a flat stainless steel plate. As shown in FIG. It has an elastic portion with a short opening formed in it. This elastic portion is a cutout layer 10 having one through hole 10a and two cutouts 10b. The upper part and the lower part of the elastic part are elastically connected.

The width of the axial web 12a is twice the plate thickness. This contributes to the improvement of the compressive elasticity of the shaft web 12a as the minimum width that allows good processing with little deformation of the opening peripheral flat portion during pressing. The axial lengths of the open through holes 10a and notches 10b are made equal to the plate thickness. This ensures a relatively long life of the punch during pressing and contributes to minimizing the axial length of the elastic portion as the minimum length that enables good mass production processability.

The load that the valve portion 63 receives from the valve seat 7 is transmitted to the cylindrical body 62 immediately after the fuel injection valve 1 collides with the closed valve. Then, both ends of the axial web 12a are compressed and deformed by the axial load, and the tubular body 62 behaves like a compression spring to absorb the impact load.

As shown in FIG. 4, the cutout layer 10 of the cylindrical body 62 has a C-shaped cross section, and the axial web 12a is not arranged point-symmetrically, so the rigidity against compressive load is uneven. As a result, when an axial load is applied to the cylindrical body 62 when the valve is closed, no stress is applied in line symmetry, and the amount of compression increases in the direction of weak rigidity. As for the valve body 6, the cutout layer 10 of the cylindrical body 62 is bent, and the armature 61 is tilted.

A similar phenomenon also occurs immediately after the fuel injection valve 1 collides with the valve opening. When the bending amount of the cylindrical body 62 increases, the armature 61 comes into contact with the inner peripheral surface 5a of the holder, the valve portion 63 comes into contact with the inner peripheral surface 7a of the valve seat, receives frictional resistance, and the elasticity of the tubular body 62 in the axial direction increases. Inhibit deformation.

By the way, as shown in FIG. ₂ , the clearance C1 of the armature sliding portion 61a, which is the margin of interference due to the tilting of the armature 61, C ₁ >C ₂ is set for clearance C ₂ .

The elastic portion of the tubular body 62 is formed relatively short in the axial direction. As shown in FIG. ₂ , the distance L1 from the elastic portion to the armature sliding portion 61a and the distance L2 from the elastic portion to the valve portion sliding portion 63a _are uniquely defined, facilitating mass production management. _The tilting amount of the armature 61 when the valve is closed is proportional to the distance L1, and the tilting amount of the valve portion 63 when the valve is open is proportional to the distance _L2 , where _L1 > _L2 . Since the amount of inclination is adjusted according to the interference margin, the armature 61 or the valve portion 63 is prevented from interfering excessively. As a result, the operating noise is suppressed.

Thus, by setting the clearance to C ₁ >C ₂ , the margin for interference due to tilting of the armature 61 when the valve is closed is made larger than the margin for tilting of the valve body 6 when the valve is opened. In addition, the axial length of the elastic portion formed in the tubular body 62 is relatively short, and the bent portion at the time of opening and closing the valve is defined at substantially one axial location. Furthermore, by setting the position of the elastic portion so that distance L ₁ >distance L ₂ , the deflection amount of the armature 61 when opening and closing the valve is made larger than the deflection amount of the valve body 6 . These prevent the armature 61 or the valve body 6 from interfering with mating parts such as the inner peripheral surface 5a of the holder and the inner peripheral surface 7a of the valve seat when the valve is opened or closed. Alternatively, by appropriately adjusting the amount of interference so that either the armature 61 or the valve portion 63 does not interfere excessively with the mating part, the frictional resistance caused by the interference does not hinder the elastic deformation of the cylindrical body 62 as much as possible. , suppresses the operating noise by absorbing the impact load when opening and closing the valve.

A notch layer 10 is formed in the intermediate portion of the tubular body 62, and the upper and lower portions of the notch layer 10 are connected via an axial web 12a. With such a configuration, the load received by the valve portion 63 from the valve seat immediately after the fuel injection valve collides with the valve to close is transmitted to the cylindrical body 62, and the upper and lower ends of the shaft web 12a receive the load in the axial direction and are compressed. By deforming, the cylindrical body 62 behaves like a compression spring and absorbs the impact load. By using the cutout layer ₁₀ formed only in the intermediate portion as the elastic portion, the elastic portion can be formed in _a relatively simple shape, and the production control of the distance L1 and the distance L2 can be facilitated. can.

In the above-described embodiment, the elastic portion includes one through hole 10a which is shorter in the axial direction than the circumferential direction, two notches 10b, and a notch layer 10 having an axial web 12a between the openings. Although formed around the axially intermediate portion of the cylindrical body 62 in the axial direction, the number of openings forming the cutout layer 10 is not limited to this.

Embodiment 2.
FIG. 5 is a diagram showing a state before roll processing of a cylindrical body 62 different from that of the first embodiment. In FIG. 5, the elastic portion of the tubular body 62 is formed from the notch layer 10 and the through layer 11 having two through holes 10a downstream of the notch layer 10 via a circumferential plate portion (peripheral web) 12b. Become.

The width of the peripheral web 12b is twice the plate thickness. This contributes to the improvement of the bending elasticity of the peripheral web 12b as the minimum width that allows good processing with little deformation of the opening peripheral flat portion during pressing. The openings formed in the notch layer 10 and the penetrating layer 11 are arranged in the circumferential direction of the cylindrical body 62 with a 1/2 pitch shift of the openings, and the circumferential length of the circumferential web 12b is made uniform. The cutout layer 10 and the penetration layer 11 are connected via a peripheral web 12b, and the upper and lower portions of the elastic portion are elastically connected by two axial webs 12a and one peripheral web 12b. With such a configuration, the effect of suppressing the operation noise is further enhanced as compared with the first embodiment as a form that is easily deformed elastically.

Thus, in Embodiment 2, the cutout layer 10 and the penetration layer 11 are connected via the peripheral web 12b. The load received by the valve portion 63 from the valve seat immediately after the fuel injection valve collides to close the valve is transmitted to the cylindrical body 62, and both ends of the peripheral web 12b receive the load in the axial direction and bend and deform the cylindrical body. 62 behaves like a compression spring and absorbs the impact load. The configuration of the peripheral web 12b and the axial web 12a makes it easy to elastically deform.

Embodiment 3.
FIG. 6 is a diagram showing an example of a state before rolling the tubular body 62 when welding the armature 61 and the valve portion 63 to the tubular body 62 .
Since welding is performed in the axial direction above and below the cylindrical body 62, when the cutout layer 10 is arranged on the welding side of the cylindrical body 62, the heat dissipation path of the heat generated during welding is blocked by the cutouts, resulting in high heat. , deformation or spatter may occur. In this embodiment, as shown in FIG. 6, the penetration layer 11 is arranged on the welding side, so that the heat generated when the armature 61 and the tubular body 62 are welded is radiated from the shaft web 12a of the penetration layer 11 located on the welding side. be done. Since the penetrating layer 11 has more axial webs 12a than the cutout layer 10, heat dissipation is improved. In particular, there is concern about the heat dissipation of the C-shaped end, but since the axial web 12a is arranged in this portion of the penetrating layer 11, the heat dissipation is ensured. These can prevent deformation and spatter due to high heat during welding.

With such a configuration, the heat generated when the armature 61 and the cylindrical body 62 are welded is radiated from the axial web 12a of the penetration layer 11 positioned on the welding side. It should be noted that the contents described above have the same effect even when the valve portion 63 and the cylindrical body 62 are welded.

While this application describes various exemplary embodiments and examples, various features, aspects, and functions described in one or more embodiments may not apply to particular embodiments. can be applied to the embodiments singly or in various combinations.
Accordingly, numerous variations not illustrated are envisioned within the scope of the technology disclosed herein. For example, modification, addition or omission of at least one component, extraction of at least one component, and combination with components of other embodiments shall be included.

1: fuel injection valve, 2: solenoid device, 3: core, 4: spring, 5: holder, 5a: holder inner peripheral surface, 6: valve body, 61: armature, 61a: armature sliding part, 62: tubular Body 63: Valve portion 63a: Valve portion sliding portion 7: Valve seat 7a: Valve seat inner peripheral surface 8: Plate 10: Notch layer 10a: Through hole 10b: Notch 11: penetration layer, 12a: axial web, 12b: peripheral web

Claims (4)

A valve body having an armature made of a magnetic material, a tubular body coupled to the armature, and a valve portion coupled to the tubular body axially slides in the holder by magnetic attraction force of the solenoid device. In the fuel injection valve, the cylindrical body has a C-shaped cross section, and is provided with an elastic portion having an opening shorter in the axial direction than in the circumferential direction at an axially intermediate portion of the cylindrical body. The clearance between the armature sliding portion that serves as a guide during movement is set larger than the clearance between the valve portion and the valve portion sliding portion that serves as a guide during sliding, and the armature sliding portion acts as a guide during sliding. A fuel injection valve, wherein the distance to the moving portion is longer than the distance from the elastic portion to the valve portion sliding portion. The opening of the elastic portion includes at least one through hole and at least one notch formed in the end of the cylindrical body, and has an axial plate portion between the through hole and the notch. 2. The fuel injection valve according to claim 1, characterized in that: The opening of the elastic portion further has another through-hole that is displaced from the through-hole in the axial direction and the circumferential direction, and has a circumferential plate portion between the through-hole and the other through-hole. 3. The fuel injection valve according to claim 2, characterized in that: 3. The cylindrical body, the armature, and the valve portion are welded together, and the other through holes are formed on the armature side and the valve portion side of the cylindrical body, respectively. 4. The fuel injection valve according to 3.

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