JP2006009705A - Fuel injection amount adjusting method in assembly of electromagnetic fuel injection valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid deterioration and lowering in yield caused by generation of chips when setting an axial position of a spring receiver member in a fixed core and adjust a fuel injection amount, in assembly of an electromagnetic fuel injection valve. <P>SOLUTION: The fuel injection amount is adjusted in assembly by sequentially performing: a first step for temporally press-fitting the spring receiver member 27 into the fixed core 22 from behind the fixed core separated at least from a valve seat member 10; a second step for cleaning from both ends of the fixed core 22 to eliminate the chips which is generated when the fixed core 22 is temporally press-fitted into the spring receiver member 27; and a third step for connecting the valve seat member 10 with the fixed core through a magnetic cylinder body 9 so that the return spring 23 and the valve assembly 17 are arranged between the valve member 10 and the fixed core 22, checking the fuel injection amount with a state where the fixed core 22 is surrounded by a coil assembly 24, and finally press-fitting the spring receiver member 27 into the fixed core 22 so that the spring receiver member 27 can move a minute amount in the fixed core. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an improvement in a method for adjusting a fuel injection amount by determining an axial position of a spring receiving member in a fixed core when an electromagnetic fuel injection valve is assembled.

A spring receiving member is press-fitted into a cylindrical fixed core, and a return spring is compressed between the spring receiving member and a valve assembly formed by coaxially coupling a movable core and a valve body whose rear end faces the front end of the fixed core. An electromagnetic fuel injection valve provided is already known from, for example, Patent Document 1 and the like.
JP 2003-314399 A

  By the way, when the axial position of the spring receiving member in the fixed core is changed, the spring load of the return spring that is contracted between the spring receiving member and the valve assembly changes, and accordingly, the electromagnetic fuel injection valve In order to adjust the fuel injection amount, it is necessary to change the axial position of the spring receiving member in the fixed core. In the fuel injection valve, the fuel injection amount is confirmed while changing the press-fitting position of the spring receiving member into the fixed core with the electromagnetic fuel injection valve almost assembled except for the state where the rear of the fixed core is opened. After the position of the spring receiving member is determined so that a desired fuel injection amount can be obtained, chips are removed in a reverse cleaning process in which a cleaning liquid is supplied to the electromagnetic fuel injection valve from its front end side.

  However, it is difficult to reliably remove the chips generated by press-fitting the spring receiving member into the fixed core in the back washing process, resulting in a decrease in quality and a decrease in yield.

  The present invention has been made in view of such circumstances, and can adjust the fuel injection amount when assembling the electromagnetic fuel injection valve while avoiding quality deterioration and yield deterioration due to generation of chips. It is an object of the present invention to provide a fuel injection amount adjusting method when assembling the electromagnetic fuel injection valve.

  In order to achieve the above object, the invention according to claim 1 is directed to a cylindrical fixed core surrounded by a coil assembly in which a coil is wound around a bobbin and to which a magnetic cylindrical body is coaxially coupled. A cylindrical spring bearing member having a single slit extending in the direction and having a substantially C-shaped cross-sectional shape is press-fitted with an axial position adjustable, and is coaxially coupled to the front end of the magnetic cylindrical body. A valve assembly that is seated on a valve seat provided in a valve seat member, a valve assembly in which a movable core having a rear end facing the front end of the fixed core is coaxially coupled, and the spring receiving member, When the electromagnetic fuel injection valve is assembled, a return spring is contracted and a fuel passage is formed in the fixed core and the spring receiving member for flowing fuel flowing in from the rear end side of the fixed core. Axial position of member in fixed core In determining and adjusting the fuel injection amount, a first step of temporarily press-fitting the spring receiving member from the rear side into the fixed core separated from at least the valve seat member, and a spring receiver to the fixed core A second step of performing cleaning from both ends of the fixed core in order to remove chips generated by temporary press-fitting of the member, and the valve so that the return spring and the valve assembly are disposed between the fixed core and The seat member is coupled to the fixed core via the magnetic cylindrical body, and the spring receiving member is moved by a small amount within the fixed core while checking the fuel injection amount in a state where the fixed core is surrounded by the coil assembly. The third step of finally performing the press-fitting process is sequentially executed.

  According to a second aspect of the invention, in addition to the configuration of the first aspect of the invention, after the second step, the return spring is brought into contact with the front end of the spring receiving member from the front side of the fixed core. It is characterized by being assembled.

  Furthermore, the invention described in claim 3 is characterized in that, in addition to the configuration of the invention described in claim 1 or 2, the minute press-fitting amount of the spring receiving member in the third step is 100 μm or less.

  According to the first aspect of the present invention, when the electromagnetic fuel injection valve is assembled, the spring receiving member is temporarily press-fitted from the rear side into the fixed core that is separated from at least the valve seat member in the first step. The chips generated by the temporary press-fitting are removed by washing from both ends of the fixed core in the second step, and the majority of the required press-fitting amount is covered by the temporary press-fitting, Most of the chips that can be generated by the press-fitting of the spring receiving member can be easily removed by washing from both ends of the fixed core that is open at both ends. Moreover, in the third step, the spring receiving member is finally press-fitted so as to move the minute amount within the fixed core while checking the fuel injection amount in a state in which the valve assembly can be opened and closed. In the final press-fitting process of the receiving member, almost no chips are generated. Therefore, it is possible to adjust the fuel injection amount while avoiding deterioration in quality and deterioration in yield due to generation of chips when the electromagnetic fuel injection valve is assembled.

  According to the second aspect of the invention, since the return spring is assembled from the front side of the fixed core, it is possible to improve the assembly efficiency so that there is no step in the assembly path of the return spring. it can.

  Further, according to the invention described in claim 3, since the spring receiving member moves by an extremely minute amount of 100 μm or less by the final press-fitting process, it is possible to reliably suppress the generation of chips when adjusting the fuel injection amount. .

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.

  1 to 6 show an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of an electromagnetic fuel injection valve. FIG. 2 is a longitudinal sectional view for explaining temporary press-fitting of a spring receiving member. 3 is a longitudinal sectional view for explaining the cleaning of the spring receiving member after temporary press-fitting, FIG. 4 is a longitudinal sectional view for explaining the assembly of the return spring, the valve assembly and the valve seat member, and FIG. 5 is the fuel injection. FIG. 6 is a longitudinal sectional view for explaining final cleaning, and FIG. 6 is a longitudinal sectional view for explaining the amount adjustment.

  First, referring to FIG. 1, an electromagnetic fuel injection valve for injecting fuel into an engine (not shown) is a valve body which is spring-biased in a direction in which the valve seat 8 has a valve seat 13 at the front end thereof. And a solenoid housing in which a coil assembly 24 capable of exerting an electromagnetic force for driving the valve body 20 on the side separated from the valve seat 13 is connected to the valve housing 8. The solenoid unit 6 accommodated in the coil 25 and the coupler 40 that faces the connection terminals 38 connected to the coil 30 of the coil assembly 24 are integrally provided so that at least the coil assembly 24 and the solenoid housing 25 are embedded. And a covering portion 7 made of synthetic resin.

  The valve housing 8 includes a magnetic cylindrical body 9 formed of a magnetic metal and a valve seat member 10 that is liquid-tightly connected to the front portion of the magnetic cylindrical body 9 by welding in a press-fitted state. The valve seat member 10 is welded to the magnetic cylinder 9 with its rear end fitted to the front end of the magnetic cylinder 9, and the valve seat member 10 opens to the front end surface thereof. A fuel outlet hole 12, a tapered valve seat 13 connected to the inner end of the fuel outlet hole 12, and a guide hole 14 connected to the rear end large diameter portion of the valve seat 13 so as to guide the valve body 20. Are provided coaxially. A steel plate injector plate 16 having a plurality of fuel injection holes 15 leading to the fuel outlet hole 12 is welded to the front end of the valve seat member 10 in a liquid-tight manner.

  The solenoid unit 6 includes a cylindrical movable core 18, a cylindrical fixed core 22 that faces the movable core 18, and a return spring that exerts a spring force that biases the movable core 18 toward the side away from the fixed core 22. 23 and an electromagnetic force that attracts the movable core 18 toward the fixed core 22 against the spring force of the return spring 23 while being arranged so as to surround the rear portion of the valve housing 8 and the fixed core 22. A coil assembly 24, and a solenoid housing 25 surrounding the coil assembly 24 so that the front end of the valve assembly 8 is connected to the valve housing 8.

  The movable core 18 is slidably fitted to the rear portion of the valve housing 8, and the movable core 18 is coaxial with the valve body 20 that can be seated on the valve seat 13 and close the fuel outlet hole 12. The valve assembly 17 is configured by being connected to each other. In this embodiment, the movable core 18, the valve shaft 19 integrally connected to the movable core 18, and the valve body 20 integrally formed at the front end of the valve shaft 19 constitute a valve assembly 17. In the valve assembly 17, a through hole 21 communicating with the inside of the valve housing 8 is formed coaxially with a bottomed shape with the front end closed, and the valve assembly 17 is a return spring on the side where the valve body 20 is seated on the valve seat 13. 23 is energized.

  The rear end of the magnetic cylinder 9 in the valve housing 8 is coaxial with the front end of the fixed core 22 via a nonmagnetic cylinder 26 as a nonmagnetic member formed in a circular cross section by a nonmagnetic metal such as stainless steel. The rear end of the magnetic cylinder 9 is butt welded to the front end of the nonmagnetic cylinder 26, and the rear end of the nonmagnetic cylinder 26 connects the front end of the fixed core 22 to the nonmagnetic cylinder 26. It is welded to the fixed core 22 in a fitted state.

  The fixed core 22 is integrally formed with an extended cylindrical portion 22c extending rearward from the coil assembly 24. The fixed core 22 has a small diameter hole 51 and the small diameter hole. A large-diameter hole 52 having a diameter larger than that of the small-diameter hole 51 and a tapered hole 53 connecting the small-diameter hole 51 and the large-diameter hole 52 are provided coaxially.

  In the small diameter hole 51 of the fixed core 22, a spring receiving member 27 having a single slit 27a extending in the axial direction and having a substantially C-shaped cross section is press-fitted coaxially so that the axial position can be adjusted. The return spring 23 is interposed between the spring receiving member 27 and the movable core 18.

  A ring-shaped stopper 28 made of a non-magnetic material is fixed to the inner periphery of the rear end of the cylindrical movable core 18 from the rear end surface of the movable core 18 so as to avoid the movable core 18 coming into direct contact with the fixed core 22. It is press-fitted so as to slightly protrude toward the core 22 side. The coil assembly 24 is formed by winding a coil 30 around a bobbin 29 surrounding the rear portion of the valve housing 8, the nonmagnetic cylindrical body 26 and the fixed core 22.

  The solenoid housing 25 has an annular end wall 31a opposite to the valve portion 5 side end of the coil assembly 24 at one end, and has a cylindrical shape surrounding the coil assembly 24, and is formed of a magnetic metal 31 made of magnetic metal. And a flange portion 22a that protrudes radially outward from the rear end portion of the fixed core 22 and faces the end portion on the opposite side of the valve portion 5 of the coil assembly 24. The flange portion 22a The other end of the magnetic frame 31 is magnetically coupled. In addition, a fitting cylinder portion 31b for fitting the magnetic cylinder body 9 in the valve housing 8 is coaxially provided on the inner periphery of the end wall 31a of the magnetic frame 31, and the solenoid housing 25 is provided with the fitting cylinder portion. The valve housing 8 is connected to the valve housing 8 by fitting the valve housing 8 to 31b.

  The fuel filter 34 is attached to the large-diameter hole 52 which the fixed core 22 has in the rear part. In addition, a fuel passage 35 communicating with the through hole 21 of the movable core 18 is formed in the fixed core 22 and the spring receiving member 27.

  The covering portion 7 fills not only the solenoid housing 25 and the coil assembly 24 but also a part of the valve housing 8 and most of the inlet cylinder 33 while filling the gap between the solenoid housing 25 and the coil assembly 24. The magnetic frame 31 of the solenoid housing 25 is provided with a notch 36 for arranging an arm portion 29a formed integrally with the bobbin 29 of the coil assembly 24 outside the solenoid housing 25. It is done.

  A coupler 40 is integrally provided on the covering portion 7 so as to face the connection terminals 38 connected to both ends of the coil 30 in the coil assembly 24. The base end of the connection terminal 38 is provided on the arm portion 29a. The coil ends 30 a of the coil 30 are welded to the connection terminals 38.

  Incidentally, the covering portion 7 includes a first resin molding layer 7a that covers the solenoid housing 25 and constitutes a part of the coupler 40, and a second resin molding layer 7b that covers the first resin molding layer 7a. The first resin molding layer 7a is not covered with the second resin molding layer 7b and is exposed to the outside from the middle portion of the coupler 40, and the rear portion of the inlet tube 33 is covered with the second resin molding layer 7b. The first resin molding layer 7a is not covered with the second resin molding layer 7b at the portion corresponding to the rear portion of the valve housing 8, and is exposed to the outside. Thus, the first resin molding layer 7a at the middle portion of the coupler 40 and the portion corresponding to the rear portion of the valve housing 8 has endless engagement grooves 48 for engaging the end portions of the second resin molding layer 7b. 49 is formed, and an endless engagement groove 50 for engaging the end portion of the second resin molding layer 7 b is provided on the outer periphery of the intermediate portion of the inlet tube 33. That is, the end portion of the second covering portion 7 b is engaged with the first covering portion 7 a and the inlet tube 33 in an uneven manner.

  The front end of the nonmagnetic cylindrical body 26 surrounds a part of the movable core 18 and is coaxially coupled to the rear end of the magnetic cylindrical body 9 in the valve housing 8 by butt welding. The front part of the fixed core 22 with the front end facing the rear end of the movable core 18 is fitted and fixed.

  A small-diameter fitting portion 22 b that forms an annular stepped portion 43 facing forward is provided coaxially at the front portion of the fixed core 22, and the small-diameter fitting portion 22 b is formed on the nonmagnetic cylindrical body 26. It is fitted to the rear part of the nonmagnetic cylindrical body 26 until the stepped part 43 comes into contact with the rear end of the nonmagnetic cylindrical body 26 so as to be in close contact with the inner surface of the intermediate part. It is fixed to the magnetic cylinder 26.

  An intermediate portion of the movable core 18 is provided with a guide portion 18a slidably in contact with the inner peripheral surface of the rear portion of the magnetic cylindrical body 9, and the valve body 20 is slidable on the inner peripheral surface of the valve seat member 10, that is, the guide hole 14. There is provided a journal portion 20a to be fitted to.

  The fuel injection amount of such an electromagnetic fuel injection valve is adjusted by determining the spring force of the return spring 23, that is, the axial position of the spring receiving member 27 in the fixed core 22 when the electromagnetic fuel injection valve is assembled. In adjusting the fuel injection amount, first, as shown in FIG. 2, the spring receiving member 27 is temporarily press-fitted into the fixed core 22 in a state separated from the valve seat member 10 from the rear side. The first step is executed.

  Thus, in this embodiment, the coil assembly 24 accommodated in the solenoid housing 25 so as to surround the fixed core 22 to the fixed core 22 to which the magnetic cylindrical body 9 is coupled via the nonmagnetic cylindrical body 26. Are fixed together with the coil assembly 24 and the solenoid housing 25 embedded in the covering portion 7, with the coupler 40 integrally facing the connection terminals 38 connected to the coils 30 of the coil assembly 24. A first step of temporarily press-fitting the spring receiving member 27 into the core 22 is executed.

  In the next second step, as shown in FIG. 3, cleaning from both ends of the fixed core 22 is performed in order to remove chips generated by temporary press-fitting of the spring receiving member 27 into the fixed core 22.

  After the completion of the cleaning in the second step, the third step is executed. In this third step, first, as shown in FIG. 4, the return spring 23 and the valve assembly 17 are placed between the fixed core 22. The valve seat member 10 to which the injector plate 16 is fixed is coupled to the fixed core 22 via the magnetic cylindrical body 9. In this state, the fixed core 22 is surrounded by the coil assembly 24. In this state, as shown in FIG. 5, the spring receiving member is moved so as to move a small amount in the fixed core 22 while checking the fuel injection amount. 27 is finally press-fitted.

  In addition, when the third step is executed after the second step is completed, the return spring 23 is assembled from the front side of the fixed core 22 so as to contact the front end of the spring receiving member 27, and the third step. The minute press-fitting amount of the spring receiving member 27 is 100 μm or less.

  After the completion of the third step, as shown in FIG. 6, if necessary, a cleaning liquid is flowed from the valve seat member 10 side for final cleaning, and then the fuel filter 34 is inserted into the large-diameter hole of the fixed core 22. By attaching to 52, the assembly of the electromagnetic fuel injection valve is completed.

  Next, the operation of this embodiment will be described. When the electromagnetic fuel injection valve is assembled, the spring receiving member 27 is attached from the rear side to the fixed core 22 that is separated from at least the valve seat member 10 in the first step. Temporary press-fitting is performed, and chips generated by the temporary press-fitting are removed by washing from both ends of the fixed core 22 in the second step, so that most of the required press-fitting amount can be covered by temporary press-fitting. By doing so, most of the chips that can be generated by press-fitting the spring receiving member 27 can be easily removed by washing from both ends of the fixed core 22 in a state where both ends are open.

  In addition, in the third step, the spring receiving member 27 is finally press-fitted so as to move the minute amount within the fixed core 22 while confirming the fuel injection amount in a state where the valve assembly 17 can be opened and closed. In the final press-fitting process of the spring receiving member 27, almost no chips are generated. Therefore, it is possible to adjust the fuel injection amount while avoiding deterioration in quality and deterioration in yield due to generation of chips when the electromagnetic fuel injection valve is assembled.

  Further, after the second step is completed, the return spring 23 is assembled from the front side of the fixed core 22 so as to contact the front end of the spring receiving member 27, so that there is no step in the assembly path of the return spring 23. Assembling efficiency can be improved.

  Further, since the spring receiving member 27 moves by the final press-fitting process in the third step is an extremely small amount of 100 μm or less, generation of chips can be reliably suppressed when adjusting the fuel injection amount.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. It is.

It is a longitudinal cross-sectional view of an electromagnetic fuel injection valve. It is a longitudinal cross-sectional view for demonstrating temporary press-fitting of a spring receiving member. It is a longitudinal cross-sectional view for demonstrating the washing | cleaning after temporary press-fitting of a spring receiving member. It is a longitudinal cross-sectional view for demonstrating assembly | attachment of a return spring, a valve assembly, and a valve seat member. It is a longitudinal cross-sectional view for demonstrating fuel injection amount adjustment. It is a longitudinal cross-sectional view for demonstrating final washing | cleaning.

Explanation of symbols

9 ... Magnetic cylinder 10 ... Valve seat member 13 ... Valve seat 17 ... Valve assembly 18 ... Movable core 20 ... Valve body 22 ... Fixed core 23 ... Return Spring 24 ... Coil assembly 27 ... Spring receiving member 27a ... Slit 29 ... Bobbin 30 ... Coil 35 ... Fuel passage

Claims (3)

  A cylindrical fixed core (22) surrounded by a coil assembly (24) formed by winding a coil (30) around a bobbin (29) and coaxially coupled with a magnetic cylindrical body (9) is axially A cylindrical spring bearing member (27) having a single slit (27a) extending in the shape and having a substantially C-shaped cross section is press-fitted with an adjustable axial position, and the magnetic cylindrical body (9) A valve body (20) that can be seated on a valve seat (13) provided on a valve seat member (10) that is coaxially coupled to the front end of the movable core, and a movable core (18) whose rear end faces the front end of the fixed core (22) ) Are coaxially coupled, and a return spring (23) is provided between the valve assembly (17) and the spring receiving member (27), and the fixed core (22) and the spring receiving member (27) Inside, the fuel flowing in from the rear end side of the fixed core (22) is circulated. When adjusting the fuel injection amount by determining the axial position of the spring receiving member (27) in the fixed core (22) when assembling the electromagnetic fuel injection valve in which the fuel passage (35) is formed, A first step of temporarily press-fitting the spring receiving member (27) from the rear side into the fixed core (22) that is separated from at least the valve seat member (10); A second step of performing cleaning from both ends of the fixed core (22) to remove chips generated by temporary press-fitting of the spring receiving member (27), the return spring (23) and the valve assembly (17) ) Is arranged between the fixed core (22) and the valve seat member (10) is coupled to the fixed core (22) via the magnetic cylinder (9) and the coil assembly (24). With the fixed core (22) surrounded An electromagnetic fuel characterized by sequentially executing a third step of finally press-fitting the spring receiving member (27) so as to move a minute amount within the fixed core (22) while checking the fuel injection amount. A method for adjusting the fuel injection amount when the injection valve is assembled.   After the second step, the return spring (23) is assembled from the front side of the fixed core (22) so as to contact the front end of the spring receiving member (27). A fuel injection amount adjusting method at the time of assembling the electromagnetic fuel injection valve.   The fuel injection amount adjusting method at the time of assembling the electromagnetic fuel injection valve according to claim 1 or 2, wherein the minute press-fitting amount of the spring receiving member (27) in the third step is 100 µm or less.

Images