CN112814817A - Valve assembly and oil sprayer - Google Patents

Abstract

The invention discloses a valve assembly, comprising a valve seat, a valve seal and a valve holder. The valve seat has a cavity, the bottom of the cavity forms a sealing surface, and the valve seal is arranged in the cavity The valve holder abuts on the valve seal in two states of being inside and forming a seal with the sealing surface or being out of the seal. A fuel injector is also disclosed, comprising a fuel injector body and a valve assembly mounted on the fuel injector body, wherein the valve assembly is the aforementioned valve assembly.

Description

Valve assembly and oil sprayer

Technical Field

The invention relates to the field of fuel injection, in particular to a valve assembly and a fuel injector.

Background

With increasingly stringent emissions regulations, high pressure common rail systems have become the mainstream of diesel fuel injection systems. The fuel injection device is a key component of a high-pressure common rail system, and the technical level of the fuel injection device directly determines the reliability, the dynamic property and the economical efficiency of an end product. Therefore, the problems of injection stability, assembly and low processing cost of the fuel injection device are solved, and product development needs to be considered.

In the structure of the fuel injection device disclosed in the prior art, the valve assembly structure thereof is shown in fig. 1. The housing accommodates a valve seat, in which a discharge throttle is formed, which is connected to a control chamber. The outlet throttle is opened or closed by a valve seal, for which purpose a sealing cone is formed on the valve seat which communicates with the throttle and a spherical valve seal is designed to open and close, the valve seal of the valve seat being seated at high speed on its seat in order to achieve the high opening and closing speeds required for the operation of the fuel injection device for internal combustion engines. The valve sealing member is opened or closed by a piston controlled by a magnetic valve or a piezoelectric element through a guide member, and the guide member is restricted by a valve holding member to enable the guide member to move radially.

Disclosure of Invention

The embodiment of the invention aims to provide a valve component and a fuel injector so as to solve the problems of difficulty in part machining and difficulty in assembly in the related technology.

According to a first aspect of the present invention, there is provided a valve assembly comprising a valve seat having a cavity therein, the cavity having a bottom forming a sealing surface, a valve seal disposed in the cavity and forming a seal with the sealing surface or being out of the seal, and a valve retainer abutting against the valve seal.

Further, the sealing surface is a conical surface.

Further, an orifice is opened in the valve seat, and the orifice communicates with the seal surface.

Further, the valve seal is a sealing ceramic ball or a steel ball.

Further, the valve retainer comprises an armature, a valve needle and a ball valve seat, the valve needle penetrates through the armature and is fixedly connected with the ball valve seat, the valve sealing member is fixed on the ball valve seat, and the armature controls the valve sealing member to open and close.

Further, the valve retainer further comprises a return spring, and two ends of the return spring are respectively abutted against the armature and the valve seat.

Further, the return spring is sleeved outside the armature.

Further, a gap exists between the armature and the ball valve seat.

According to a second aspect of the present invention there is provided a fuel injector comprising an injector body and a valve assembly mounted on the injector body, characterised in that the valve assembly is as described in the first aspect.

Further, the valve seat is fixed on the fuel injector body through a locking threaded sleeve, and a through hole for the valve retainer to pass through is formed in the locking threaded sleeve.

The technical scheme provided by the embodiment of the application can have the following beneficial effects:

according to the embodiment, the concave cavity is arranged in the valve seat, the bottom of the concave cavity forms the sealing surface, the centering function is provided for the valve sealing piece, the valve sealing piece can automatically fall onto the sealing surface under the influence of gravity on the sealing surface during assembly, and the assembly difficulty is reduced.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. It should be understood that the following described embodiments are illustrative of the present application only, and are not limiting upon the scope of the application, as illustrated in the accompanying drawings, wherein:

FIG. 1 is a cross-sectional view of a prior art valve assembly, the reference numbers in the figure having: an injector body 1; sealing the ceramic ball 2; a ball valve seat 3; a locking screw sleeve 4; a valve seat 5; a valve needle 6; an overtravel pad 7; an armature 8; a hydraulic balance hole z;

FIG. 2 is a cross-sectional view of a valve assembly provided by an embodiment of the present invention, the reference numbers in the figure having: an injector body 11; sealing the ceramic balls 12; a ball valve seat 13; a lock screw 14; a valve seat 15; a valve needle 16; an armature 17; a return spring 18; a concave cavity a; a sealing surface b; an orifice c; through the hole d.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

FIG. 1 is a prior art fuel injection assembly valve assembly for understanding the improvements of the present application in comparison to FIG. 2.

Referring to fig. 1, a valve seat 5 is shown mounted in the cavity of the injector body 1, with an orifice and sealing cone in the valve seat 5, forming an outlet throttle which is connected to a control chamber. The sealing ceramic ball 2 is a sealing device, and the opening and the closing of the throttling device are controlled by controlling the movement of the sealing ceramic ball 2, so that the fuel injection is controlled. The valve needle 6 belongs to a piston piece controlled by an electromagnetic valve, the electromagnetic valve indirectly controls the guide piece ball valve seat 3 through the valve needle 6 and an armature 8, and the motion of the valve sealing piece sealing the ceramic ball 2 is indirectly controlled. The locking screw sleeve 4 is used for fixing the valve seat 5 to form a control chamber, and is used for axially guiding the guide piece ball valve seat 3, righting the ball valve seat 3, and establishing an oil path on the locking screw sleeve 4 to ensure pressure balance for normal operation of the ball valve seat 3. The overtravel pad 7 functions to control the movement stroke of the moving member armature 8.

Referring to fig. 2, an embodiment of the present invention provides a valve assembly, which includes a valve seat 15, a valve seal and a valve retainer, wherein the valve seat 15 has a cavity a therein, the bottom of the cavity forms a sealing surface b, the valve seal is disposed in the cavity and forms a seal or is separated from the seal, and the valve retainer abuts against the valve seal.

According to the embodiment, the concave cavity is arranged in the valve seat, the bottom of the concave cavity forms the sealing surface, the centering function is provided for the valve sealing piece, the valve sealing piece can automatically fall onto the sealing surface under the influence of gravity on the sealing surface during assembly, and the assembly difficulty is reduced.

In this embodiment, the sealing surface is a conical surface. The conical surface and the steel ball form a simple and efficient sealing structure.

In the present embodiment, an orifice c is opened in the valve seat 15, and the orifice communicates with the seal surface. Due to the high fuel injection system pressures (typically above 1000bar), orifice c is designed to effectively reduce the spring force required to form the seal.

In this embodiment, the valve holder includes an armature 17, a valve needle 16, and a ball valve seat 13, the valve needle 16 passes through the armature 17 and then is connected to the ball valve seat 13, and the armature 17 controls the opening and closing of the valve seal. There is no fixed connection between the armature 17, the valve needle 16, and the ball valve seat 13, and there is relative movement in the movement.

In this embodiment, the valve holder further includes a return spring 18, and both ends of the return spring 18 are respectively abutted against the armature 17 and the valve seat 15. And is fitted over armature 17. Different from the structure of fig. 1, because the locking screw sleeve only has through holes, the return spring contacts the valve seat 15 and the armature 17, the armature is accelerated to rise, the opening speed of the sealing ceramic ball is increased, and the opening delay of the oil injection device is reduced.

In the present exemplary embodiment, a gap is present between the armature 17 and the ball seat 13. Because the armature and the valve needle are not fixedly connected, relative movement exists, and the gap provides a buffer stroke for the armature. The embodiment also provides a fuel injector, which comprises a fuel injector body 11 and a valve assembly installed on the fuel injector body 11, wherein the valve assembly is the above valve assembly.

In this embodiment, the valve seat 15 is fixed to the injector body 11 by a lock screw 14, and a through hole d through which the valve holder passes is formed in the lock screw 14. The hydraulic balance hole and the guide function of the locking screw sleeve in the figure 1 are replaced by other parts, the structure is optimized, and only the function of locking the valve seat 15 is needed to be provided, and the movement of the armature 17, the return spring 18, the valve needle 16 and the ball valve seat 13 is guaranteed not to be influenced.

It can be seen that the valve assembly of the present application (fig. 2) optimizes the ball seat 13 and increases the contact area of the ball seat 13 with the valve needle 16 and armature 17 to provide a self-righting function and a moving axial guidance function as compared to the prior art valve assembly (fig. 1). And through optimizing the ball valve seat 13, the structure of the locking threaded sleeve 14 is simplified, the functions of assembly guiding and axial guiding are cancelled, and the hydraulic balance hole z is cancelled. By optimizing the ball valve seat 13, the travel pad 7 is eliminated, the function thereof is also integrated into the armature 17, and the armature is axially limited by the ball valve seat 13. And meanwhile, the assembly is more convenient.

Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.

It will be understood that the present application is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the application is limited only by the appended claims.

Claims (10)

1. A valve assembly is characterized by comprising a valve seat, a valve sealing member and a valve retaining member, wherein the valve seat is internally provided with a concave cavity, the bottom of the concave cavity forms a sealing surface, the valve sealing member is arranged in the concave cavity and forms sealing or is separated from the sealing surface, and the valve retaining member is abutted against the valve sealing member.

2. The valve assembly of claim 1, wherein the sealing surface is a conical surface.

3. The valve assembly of claim 2, wherein an orifice is formed in the valve seat, the orifice communicating with the sealing surface.

4. The valve assembly of claim 1, wherein the valve seal is a sealing ceramic ball or steel ball.

5. The valve assembly of claim 1, wherein the valve retainer includes an armature, a valve needle and a ball seat, the valve needle passing through the armature and fixedly attached to the ball seat, the valve seal being fixed to the ball seat, the armature controlling the opening and closing of the valve seal.

6. The valve assembly of claim 5, wherein the valve retainer further comprises a return spring having ends abutting the armature and the valve seat, respectively.

7. The valve assembly of claim 6, wherein the return spring is sleeved outside the armature.

8. The valve assembly of claim 5, wherein a gap exists between the armature and the ball valve seat.

9. A fuel injector comprising a fuel injector body and a valve assembly mounted on the fuel injector body, characterised in that the valve assembly is as claimed in any one of claims 1 to 6.

10. The fuel injector according to claim 9, characterized in that the valve seat is fixed to the injector body by a lock nut in which a through hole through which the valve holder passes is opened.

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