Electromagnetically actuable intake valve for a high-pressure pump, and high-pressure pump

Abstract

The invention relates to an electromagnetically actuable intake valve for a high-pressure pump of a fuel injection system, in particular of a common-rail injection system, comprising a reciprocating valve closure element (2) that engages with a valve seat (1) and is loaded in the closing direction by the spring force of a valve spring (3) which is supported on a spring plate (4) connected to the valve closure element (2), further comprising a reciprocating armature (6) that engages with an electromagnet (5) and is loaded in the direction of the valve closure element (2) by the spring force of an armature spring (7) which is larger than that of the valve spring (3). According to the invention, the spring plate (4) has a first abutment face (9) for limiting the opening travel of the valve closure element (2) and a second abutment face (10) for mechanically coupling to the armature (6). The invention also relates to a high-pressure pump having such an intake valve.

Claims

1. An electromagnetically actuable intake valve for a high-pressure pump of a fuel injection system, comprising: a reciprocating valve closure element (2) which interacts with a valve seat (1) and which is loaded in a closing direction of the valve closure element (2) by a spring force of a valve spring (3) which is supported on a spring plate (4) connected to the valve closure element (2); and a reciprocating armature (6) which interacts with an electromagnet (5) and which is loaded in an opening direction of the valve closure element (2) by a spring force of an armature spring (7), wherein the spring force of the armature spring (7) is larger than the spring force of the valve spring (3), and wherein the spring plate (4) has a first abutment surface (8) for limiting an opening stroke of the valve closure element (2) and a second abutment surface (9) for contacting the armature (6), such that the spring plate (4) is defined by a section (10) which projects beyond the valve closure element (2) in an axial direction so as to form the second abutment surface (9).

2. The intake valve as claimed in claim 1, wherein the spring plate (4) is of sleeve-like form at least in sections and is placed on an end of the valve closure element (2).

3. The intake valve as claimed in claim 1, wherein the first abutment surface (8) is an annular end face of the spring plate (4).

4. The intake valve as claimed in claim 1, wherein the armature (6) is in the form of a solenoid plunger and is surrounded, at least regionally, by an annular magnet coil (12) of the electromagnet (5).

5. The intake valve as claimed in claim 1, wherein a central recess (13) for accommodating and supporting the armature spring (7) is formed in the armature (6).

6. The intake valve as claimed in claim 1, wherein at least one throughflow opening (14) is formed in the armature (6).

7. A high-pressure pump for a fuel injection system, the high-pressure pump comprising: a housing part (11) forming the valve seat (1), wherein the intake valve of claim 1 is integrated into the housing part (11) of the high-pressure pump.

8. The intake valve as claimed in claim 1, wherein the spring plate (4) is of sleeve-like form at least in sections and is pressed on an end of the valve closure element (2).

9. The intake valve as claimed in claim 1, wherein the first abutment surface (8) interacts in a stroke-limiting manner with a housing part (11), the housing part (11) forming the valve seat (1).

10. The intake valve as claimed in claim 1, wherein at least one throughflow opening (14), which is arranged decentrally, is formed in the armature (6).

11. The intake valve as claimed in claim 1, wherein the valve closure element (2) does not extend into the armature (6).

12. The intake valve as claimed in claim 1, wherein the armature (6) includes a central abutment surface that contacts the second abutment surface (9) of the spring plate (4).

13. An electromagnetically actuable intake valve for a high-pressure pump of a fuel injection system, comprising: a reciprocating valve closure element (2) which interacts with a valve seat (1) and which is loaded in a closing direction of the valve closure element (2) by a spring force of a valve spring (3) which is supported on a spring plate (4) connected to the valve closure element (2); and a reciprocating armature (6) which interacts with an electromagnet (5) and which is loaded in an opening direction of the valve closure element (2) by a spring force of an armature spring (7), wherein the spring force of the armature spring (7) is larger than the spring force of the valve spring (3), and wherein the spring plate (4) has a first abutment surface (8) for contacting a housing part (11) of the high-pressure pump and a second abutment surface (9) for contacting the armature (6), such that the spring plate (4) is defined by a section (10) which projects beyond the valve closure element (2) in an axial direction so as to form the second abutment surface (9).

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) A preferred embodiment of the invention will be explained in more detail below on the basis of the appended drawing.

(2) The single drawing FIGURE shows a schematic longitudinal section through an electromagnetically actuable intake valve according to the invention, which is integrated into a high-pressure pump for a fuel injection system.

DETAILED DESCRIPTION

(3) The intake valve illustrated schematically in the FIGURE is integrated into a housing part 11 of a fuel high-pressure pump. The housing part 11 forms a valve seat 1 of the intake valve. At the same time, guidance of a reciprocating valve closure element 2 of the intake valve is brought about, said element interacting with the valve seat 1 in a sealing manner. In the closing direction, the valve closure element 2 is loaded by the spring force of a valve spring 3 which surrounds that end of the valve closure element 2 which faces away from the valve seat 1. The valve spring 3 is supported both on the housing part 11 and on a spring plate 4 which is pressed onto and completely encloses the end of the valve closure element 2.

(4) In the FIGURE, the intake valve is illustrated in the open position. The opening stroke of the valve closure element 2 is in this case limited by the spring plate 4 which for this purpose has an abutment surface 8 which is formed by the annular end face of the spring plate 4 which faces toward the housing part 11. In the open position of the intake valve, the abutment surface 8 bears against the housing part 11 of the high-pressure pump. The spring force of the valve spring 3 acting in the closing direction is in this case exceeded by the spring force of an armature spring 7 which loads an armature 6 in the direction of the spring plate 4. The spring force of the armature spring 7, which spring is accommodated in a central recess 13 of the armature 6, is for this purpose selected to be larger than that of the valve spring 3. Here, the armature 6 bears against a section 10, projecting beyond the valve closure element 2, of the spring plate 4.

(5) For the purpose of closing the intake valve, there is provided an electromagnet 5 which comprises an annular magnet coil 12. If the magnet coil is electrically energized, a magnetic field builds up, the magnetic force of which moves the armature 6 upward counter to the spring force of the armature spring 7. The armature 6 detaches from the spring plate 4 in the process, with the result that the spring force of the valve spring 3 pulls the valve closure element 2 into the valve seat 1. The spring plate 4 lifts off from the housing part 11 in the process. Throughflow openings 14, which are provided in the armature 6 and are arranged decentrally, bring about pressure equalization.

(6) For the purpose of opening the intake valve, the electrical energization of the magnet coil 12 is stopped. The spring force of the armature spring 7 subsequently returns the armature 6 back into its starting position. In the process, the armature 6 abuts against an abutment surface 9 of the spring plate 4, which surface is formed by an end face, facing toward the armature 6, of the section 10 of the spring plate 4. The abutment force of the armature 6 is diverted via the spring plate 4 into the housing part 11 as soon as said plate bears against the housing part 11. Since the spring plate 4 is pressed onto the end of the valve closure element 2, the valve closure element 2 is lifted out of the valve seat 1 via the movement of the spring plate 4, and the intake valve opens. Fuel is then able to flow via a low-pressure space 15, which is delimited by the housing part 11 and a valve body 18, via the valve seat 1 into a high-pressure element space 16 of the high-pressure pump.

(7) In the case of the intake valve according to the invention which is represented, the mechanical coupling of the armature 6 to the valve closure element 2, which is required to open the intake valve, is brought about indirectly via the spring plate 4. Said plate has for this purpose the section 10, projecting beyond the valve closure element 2, with the abutment surface 9. The core of the invention is thus a modified spring plate 4. The modified spring plate 4 causes a radial joining position 17 in the region of the press fit of the spring plate 4 on the valve closure element 2 to be relieved of load, and the robustness of the intake valve increases.

(8) The invention is not restricted to the embodiment of an integrated intake valve illustrated in the FIGURE, but also includes intake valves which have a valve plate for forming the valve seat 1.