CN114687828A - Oil control valve for cam phase adjuster - Google Patents

Abstract

The present invention relates to an oil control valve for a cam phase adjuster. The engine oil control valve comprises a shell, a valve sleeve, a valve core and a one-way valve. The valve comprises a shell, a valve sleeve and a valve core, wherein the shell, the valve sleeve and the valve core are cylindrical, the valve core is axially slidably arranged on the radial inner side of the valve sleeve, and the valve sleeve is fixedly arranged on the radial inner side of the shell. The valve housing has a cavity inside a sidewall thereof and an oil port leading from a radially outer side to the cavity for communicating with a working hydraulic chamber of the cam phase adjuster, and a check valve is installed in the cavity to selectively close the oil port. Wherein the cavity extends axially within the side wall of the housing and has axially opposite open and closed ends, and wherein the one-way valve is axially inserted into the cavity from the open end of the cavity. The engine oil control valve is convenient to manufacture and assemble.

Description

Oil control valve for cam phase adjuster

Technical Field

The invention relates to the technical field of vehicles. In particular, the present invention relates to an oil control valve for a cam phase adjuster.

Background

In an internal combustion engine of a modern vehicle, a phase relationship between a crankshaft and a camshaft is changed between an advanced position and a retarded position, typically by means of a Variable Valve Timing (VVT) system, in order to adjust a Valve opening and closing time and an intake and exhaust gas amount of the internal combustion engine, thereby obtaining optimum combustion efficiency. The main component of a VVT system is a cam phase adjuster. The cam phase adjuster includes a stator and a rotor arranged coaxially, a plurality of hydraulic chambers being formed between the stator and the rotor, by means of which the phase relationship between the crankshaft and the camshaft can be changed in a targeted manner by the inflow and outflow of a hydraulic medium. Furthermore, in order to control the flow of hydraulic medium into or out of the pressure chamber, it is also necessary to install an oil control valve in the cam phase adjuster.

Fig. 1 shows an oil control valve according to the patented technology of the present applicant. As shown in fig. 1, the oil control valve includes a cylindrical housing 10', a valve sleeve 20', and a valve core 30 '. The valve sleeve 20 'is fixedly installed at a radial inner side of the housing 10', and the valve core 30 'is axially slidably installed at a radial inner side of the valve sleeve 20'. An oil inlet P 'communicated with a hydraulic source, a first oil port communicated with an advance chamber of the cam phase adjuster, and a second oil port communicated with a retard chamber are formed in the valve sleeve 20'. The diaphragm type check valve 40' is fixed in a mounting groove at the radial outer side of the oil inlet P ' through a pressure plate 60 '. A cavity is formed between the pressure plate 60 'and the valve sleeve 20' and may be communicated to a corresponding flow passage in the cam phase adjuster through corresponding through holes in the pressure plate 60 'and the housing 10', and thus to an advance chamber or a retard chamber of the cam phase adjuster. The cavity may also communicate with the interior cavity of the valve sleeve 20 'via an oil inlet P'. The check valve 40' ensures that the hydraulic fluid from the advance chamber or the retard chamber can only be opened unidirectionally toward the inside of the cavity when its own hydraulic pressure is higher than the hydraulic pressure in the cavity. In the cam phase adjuster using the engine oil control valve, if the liquid pressure in a certain advance chamber or retard chamber is too high due to the vibration of the vane, the check valve opens the oil port communicated with the advance chamber or retard chamber, so that the hydraulic fluid flows into the oil inlet P 'from the advance chamber or retard chamber and is supplemented into the advance chamber or retard chamber through the oil inlet P'. A similar flow channel design is also disclosed in the applicant's patent application DE 102017105074 a1 and the like.

In such an oil control valve, the metal sheet of the check valve can be formed only in a planar structure due to the size limitation of the diaphragm type check valve. In order to ensure the sealing of the radially outer oil holes, a separate pressure plate is required to provide a flat contact surface for the check valve. However, this mounting increases the number of parts and requires the formation of complex cavity shapes, thus increasing the cost of tooling and assembly.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is to provide an oil control valve which is convenient to manufacture and assemble.

The above technical problem is solved by an oil control valve for a cam phase adjuster according to the present invention. The engine oil control valve comprises a shell, a valve sleeve, a valve core and a one-way valve. The non-return valve is in particular a diaphragm non-return valve. The valve sleeve is arranged on the valve body, the valve core is arranged on the valve sleeve, and the valve sleeve is fixedly arranged on the valve body. The valve housing has a cavity inside a sidewall thereof and an oil port leading from a radially outer side to the cavity for communicating with a working hydraulic chamber of the cam phase adjuster, and a check valve is installed in the cavity to selectively close the oil port. Wherein the cavity extends axially within the side wall of the housing and has axially opposite open and closed ends, and wherein the one-way valve is axially inserted into the cavity from the open end of the cavity. Thus, the passage leading to the oil inlet can be conveniently utilized for mounting the check valve, and a detachable component does not need to be added. This reduces the number of parts, simplifies the assembly process, and reduces the production cost.

According to a preferred embodiment of the invention, the one-way valve may have a body portion and a support portion radially supported between the body portion and the radially inner surface of the cavity such that the body portion conforms to the radially outer surface of the cavity. This ensures sealing of the oil port by the check valve, so that hydraulic fluid from the oil port can only flow unidirectionally into the cavity through the check valve under its own hydraulic pressure higher than the hydraulic pressure in the cavity, without leaking from around the check valve. Preferably, the support portion may be a folded edge of the one-way valve, the folded edge extending radially inwardly of the body portion and abutting a radially inner surface of the cavity. Further preferably, the check valve may have two folded edges, which may be bent toward each other from both axial ends of the body portion, respectively. Such a folded edge may be formed integrally with the body portion of the one-way valve and be achieved by bending a metal sheet. Alternatively, the one-way valve may be supported in the cavity by other types of support portions or mounting structures in the cavity.

According to a further preferred embodiment of the invention, the one-way valve may axially abut the closed end of the cavity, thereby being axially positioned with respect to the cavity.

According to another preferred embodiment of the invention, the valve housing may have an open first end and a closed second end, the first end being axially opposite the second end, the open end of the cavity facing the second end of the valve housing. Generally, the radially inner side of the cavity communicates with an oil inlet of the oil control valve, and hydraulic fluid entering the oil inlet is from a space between the closed second end of the valve sleeve and the housing. Thus, hydraulic fluid from the hydraulic pressure source may flow from the open end of the cavity into the cavity and the oil inlet.

According to another preferred embodiment of the invention, the housing may have a stopper portion axially abutting an end of the check valve near the open end of the cavity, thereby restraining the check valve in the cavity.

According to another preferred embodiment of the invention, the valve sleeve may comprise a core part and a mantle part, the mantle part mantle the radially outer side of the core part, the cavity being located radially between the core part and the mantle part. In this case, the core portion may be made of a metal material in order to reduce abrasion generated on the sliding contact surface between the valve sleeve and the valve core, and the clad portion may be made of a plastic material in order to be fixedly installed in the housing. Preferably, such a valve sleeve may be manufactured by an over-molding process.

Drawings

The invention is further described below with reference to the accompanying drawings. Identical reference numbers in the figures denote functionally identical elements. Wherein:

fig. 1 shows a cross-sectional view of an oil control valve according to the prior art;

FIG. 2 illustrates a cross-sectional view of an oil control valve according to an embodiment of the present invention; and

fig. 3 illustrates a cross-sectional view of a valve housing of an oil control valve according to an embodiment of the present invention.

Detailed Description

Hereinafter, a specific embodiment of an oil control valve according to the present invention will be described with reference to the accompanying drawings. The following detailed description and drawings are included to illustrate the principles of the invention, which is not to be limited to the preferred embodiments described, but is to be defined by the appended claims.

According to an embodiment of the present invention, an oil control valve for a timing system of a vehicle engine is provided. Specifically, such oil control valves are typically installed in a cam phase adjuster of a timing system. The cam phase adjuster has a stator and a rotor that are relatively rotatable, the rotor being mounted radially inward of the stator, and an oil control valve may be fixedly mounted at the center of the rotor for controlling the flow of hydraulic fluid into or out of an advance chamber (also referred to as an a chamber) and a retard chamber (also referred to as a B chamber) formed on both sides of a vane of the rotor. The operating principle and basic structure of such cam phase adjusters are known in the art and will not be described in detail here. An embodiment of an oil control valve for such a cam phase adjuster according to the present invention will be explained in detail below mainly with reference to fig. 2 to 3.

Fig. 2 shows a sectional view of the oil control valve according to the embodiment. As shown in fig. 2, the oil control valve includes a housing 10, a valve housing 20, a valve core 30, and a check valve 40. The housing 10, the valve sleeve 20, and the valve core 30 are each substantially cylindrical members. Wherein the spool 30 is axially slidably mounted on a radially inner side of the valve sleeve 20, and the valve sleeve 20 is fixedly mounted on a radially inner side of the housing 10.

Fig. 3 shows a cross-sectional view of the valve housing 20. As shown in fig. 3, the valve sleeve 20 has axially opposed first and second ends 21, 22. Wherein the first end 21 is open and the second end 22 is closed for a main lumen 23 surrounded by the cylindrical side wall of the valve housing 20. As shown in fig. 2, the spool 30 is inserted into the main chamber 23 of the housing 20 from the open first end 21 and is abutted against the closed second end 22 by the spring 50, so that the spool 30 can slide in the main chamber 23 in the axial direction under the action of an external force.

As shown in fig. 3, the valve housing 20 has multiple sets of ports that communicate with different hydraulic flow passages. A plurality of first oil ports a (i.e., ports a) spaced apart in the circumferential direction are communicated to the cavities a located on the side of the rotor blade through respective hydraulic flow passages (not shown) in the housing 10 and the rotor, respectively. Accordingly, a plurality of second oil ports B (i.e., ports B) spaced at intervals in the circumferential direction are respectively communicated with the cavities B located at the other side of the rotor blade through the corresponding hydraulic flow passages (not shown) in the housing 10 and the rotor. A plurality of oil inlets P (i.e., P ports) spaced along the circumferential direction are respectively communicated to the hydraulic source through corresponding hydraulic flow passages in the valve housing 20. The first oil ports a are circumferentially arranged in one-to-one alignment with the corresponding second oil ports B, and circumferentially staggered from the corresponding oil inlets P. In the present embodiment, the number of the first oil ports a, the second oil ports B, and the oil inlets P of the valve sleeve 20 is four, respectively, and the oil inlets P are axially located between the first oil ports a and the second oil ports B, but this is only illustrative, the valve sleeve 20 may have a greater or lesser number of these oil ports, and the arrangement order of the different oil ports in the axial direction may possibly be changed.

Referring again to fig. 2, the spool 30 has an annular groove 31 formed radially outward. The annular groove 31 has an axial extension such that a relatively closed space is formed between the annular groove 31 and the inner wall of the valve sleeve 20. Depending on the axial position of the valve spool 30 in the valve housing 20, the space may communicate the first port a or the second port B of the valve housing 20 with the oil inlet P. When the spool 30 is located in a certain area range near the left side in the drawing, the ring groove 31 may communicate the oil inlet P with the first port a, so that hydraulic fluid from the hydraulic pressure source may flow from the oil inlet P into the respective a cavities of the cam phase adjuster through the first port a; and when the spool 30 is located in a certain area range near the right side in the drawing, the ring groove 31 may communicate the oil inlet P with the second port B, so that the hydraulic fluid from the hydraulic pressure source may flow from the oil inlet P into the respective B chambers of the cam phase adjuster through the second port B.

As shown in fig. 3, the valve sleeve 20 has, in addition to a main interior chamber 23 surrounded by a side wall, at least one cavity 24 extending axially within its side wall. Each cavity 24 communicates with, and is respectively substantially circumferentially aligned with, a respective oil inlet P, such that the oil inlet P is formed as a through hole communicating the respective cavity 24 with the main internal cavity 23. Radially outside each cavity 24, the valve sleeve 20 furthermore has oil bores in the form of two respective through holes, namely a first bore 25 and a second bore 26. In correspondence with these two holes, the housing 10 also has two additional oil holes, a third hole 11 and a fourth hole 12, as shown in fig. 2. Wherein the first hole 24 is aligned with the third hole 11 and the second hole 26 is aligned with the fourth hole 12. The cavity 24 can be connected to a chamber a via the first bore 24, the third bore 11 and a corresponding hydraulic channel (not shown) in the rotor, and can also be connected to a chamber B corresponding to the chamber a via the second bore 26, the fourth bore 12 and a corresponding hydraulic channel (not shown) in the rotor.

As shown in fig. 3, since the cavity 24 is formed inside the side wall, the cavity 24 is located offset radially outward of the main lumen 23, that is, an area surrounded by the outer peripheral contour of the cross section of the cavity 24 and an area surrounded by the outer peripheral contour of the cross section of the main lumen 23 are distant from each other without overlapping as viewed in a section perpendicular to the axial direction. The cavity 24 has axially opposite open and closed ends. Wherein the open end of the cavity 24 is directed towards the second end 22 of the valve housing 20 and the closed end of the cavity 24 is directed towards the first end 21 of the valve housing 20. That is, the opening direction of the cavity 24 is opposite to the opening direction of the main lumen 23. Hydraulic fluid from the hydraulic source may flow from the open end of the cavity 24 to the oil inlet P.

A one-way valve 40 is mounted in each cavity 24. In the present embodiment, the check valve 40 is a member made of an elastic metal sheet. The non-return valve 40 has two flaps (not shown) which can be opened unidirectionally towards the radially inner cavity 24 and which are aligned with the first and second openings 25, 26, respectively. The check valve 40 may selectively close the first and second holes 25 and 26. That is, when the hydraulic fluid from the a or B chamber acts on the respective flap at a greater hydraulic pressure than the hydraulic pressure in the cavity 24, the flap will open toward the interior of the cavity 24, allowing hydraulic fluid from the respective a or B chamber to flow into the cavity 24. In this case, on the one hand, the cavity 24 needs to have a certain radial length, at least in correspondence of the opening position of the flap, in order to make room for the flap to open, and on the other hand, the non-return valve 40 needs to fit tightly against the radially outer surface of the cavity 24 in the cavity 24, in order to ensure the sealing of the first and second holes 25, 26. For this, the check valve 40 may be preferably formed as an elastic member bent from an elongated metal sheet extending in the axial direction. Specifically, the check valve 40 may have a main body portion 41 and two folded edges 42. The body portion 41 is a middle portion of the elongated metal sheet that closely conforms to the radially outer surface of the cavity 24. Since the elongated metal piece is difficult to be processed into an arc shape in the width direction, in order to ensure the close fitting, the radially outer side surfaces of the main body portion 41 and the cavity 24 are both flat surfaces, i.e., both extend not only in a straight line in the axial direction but also in a straight line in a cross section perpendicular to the axial direction. The two folded edges 42 are connected to opposite ends of the main body portion 41, in particular, to axial ends of the main body portion 41, respectively, and are bent oppositely such that the two folded edges 42 extend radially inward of the main body portion 41, respectively. In this case, one side of each folded edge 42 faces radially outward, and the other side faces radially inward. The radially inwardly facing side of the folded edge 42 abuts the radially inner surface of the inner cavity 24. Due to the elasticity of the metal sheet itself, when the one-way valve 40 is mounted in the cavity 24, the two folded edges 42 will be radially supported between the body portion 41 and the radially inner surface of the inner cavity 24, so that the body portion 41 fits tightly on the radially outer surface of the inner cavity 24. At this time, the cavity 24 may have a substantially rectangular cross section in a section passing through the center axis of the oil control valve as shown in fig. 3. Preferably, the two folded edges 42 do not extend radially outside the oil inlet P, thereby preventing blockage of the oil inlet P.

When installing such a one-way valve 40, the one-way valve 40 may be axially inserted into the cavity 24 directly from the open end of the cavity 24. To facilitate positioning of the check valve 40 in the axial direction, an end of the check valve 40 facing the closed end of the cavity 24 may axially abut the closed end of the cavity 24 when the check valve 40 is installed in the cavity 24. While the other end of the one-way valve 40 may extend out of the cavity 24 or be fully inserted into the cavity 24, which may be accomplished by adjusting the length relationship of the two according to different needs. Further, the housing 10 may also have a stopper portion (not shown), which may be a raised portion on an inner sidewall or end wall of the housing 10, which may axially abut an end portion of the check valve 40 near the open end of the cavity 24 when the valve sleeve 20 with the check valve 40 is installed in the housing 10, thereby restraining the check valve 40 in the cavity 24.

In the oil control valve according to the present invention, one or more cavities 24 may be formed in the valve housing 20, each cavity 24 corresponding to a different one of the oil inlets P, and a corresponding check valve 40 is installed in each cavity 24. In fig. 2 and 3 of the present embodiment, two cavities 24 and two check valves 40 are schematically shown, which are evenly spaced in the circumferential direction. However, it will be appreciated by those skilled in the art that more (e.g., three, four) or fewer (e.g., one) cavities 24 and one-way valves 40 may be provided.

For ease of manufacture, the valve sleeve 20 according to the above embodiment may be constructed of a core portion 27 and a sheath portion 28. Here, the core portion 27 is a substantially cylindrical portion made of, for example, a metal material, and the sheath portion 28 is a portion made of, for example, a plastic material, which is wrapped radially outside the core portion 27. The core portion 27 may also form the closed second end 22 of the valve sleeve 20. The core portion 27 made of a high-strength metal material contacts the sliding valve core 30, thereby preventing the inner wall of the valve sleeve 20 from being worn. The cladding portion 28, which is made of plastic material, contacts the stationary housing 10, facilitating installation and reducing structural weight and material costs. The cavity 24 may preferably be located radially between the cored portion 27 and the cladded portion 28. Preferably, such a valve sleeve 20 may be manufactured by an over-molding process. The core portion 27 is placed in a mold and a liquid cladding material is poured and cooled to form the cladding portion 28 and cavity 24.

The engine oil control valve has simple structure and easy processing and assembly, thereby effectively reducing the production cost. In addition, the valve sleeve 20 of this design can be used directly with existing product components, thereby further reducing design and manufacturing costs.

In another embodiment according to the present invention, the structure of the check valve 40 may be changed. In particular, the check valve 40 may have different support means. For example, the body portion 41 of the one-way valve 40 may be supported in the cavity 24 by other forms of support portions, such as by leg portions or protruding portions that are integrally formed with or attached to the body portion 41. Alternatively, the one-way valve 40 may be secured by a mounting structure in the cavity 24, such as a snap groove or the like on the inner wall of the cavity 24.

According to yet another embodiment of the invention, the valve sleeve 20 can also be manufactured in different ways. For example, the valve sleeve 20 may be manufactured by being integrally injection molded or machined. Further, the valve sleeve 20 may be integrally formed of only a metal material.

Although possible embodiments have been described by way of example in the above description, it should be understood that numerous embodiment variations exist, still by way of combination of all technical features and embodiments that are known and that are obvious to a person skilled in the art. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. From the foregoing description, one of ordinary skill in the art will more particularly provide a technical guide to convert at least one exemplary embodiment, wherein various changes may be made, particularly in matters of function and structure of the components described, without departing from the scope of the following claims.

List of reference numerals

10. 10' shell

11 third hole

12 fourth hole

20. 20' valve sleeve

21 first end

22 second end

23 main lumen

24 cavity

25 first hole

26 second hole

27 core part

28 coating part

30 valve core

31 ring groove

40 one-way valve

41 body part

42 folded edge

50 spring

60' pressing plate

A first oil port/A port

B second oil port/B port

P oil inlet/P port

Claims (10)

1. An oil control valve for a cam phase adjuster, comprising a housing (10), a valve housing (20), a valve core (30), and a check valve (40), wherein the housing (10), the valve housing (20), and the valve core (30) are cylindrical, the valve core (30) is axially slidably installed at a radial inner side of the valve housing (20), the valve housing (20) is fixedly installed at a radial inner side of the housing (10), the valve housing (20) has a cavity (24) inside a sidewall thereof and an oil port leading from a radial outer side to the cavity (24) for communicating with a working hydraulic chamber of the cam phase adjuster, the check valve (40) is installed in the cavity (24) to selectively close the oil port,

it is characterized in that the preparation method is characterized in that,

the cavity (24) extends axially within the side wall of the valve housing (20) and has axially opposite open and closed ends, and the one-way valve (40) is axially inserted into the cavity (24) from the open end of the cavity (24).

2. An oil control valve according to claim 1, characterized in that the check valve (40) has a main body portion (41) and a support portion radially supported between the main body portion (41) and a radially inner side surface of the cavity (24) such that the main body portion (41) abuts the radially outer side surface of the cavity (24).

3. An oil control valve according to claim 2, characterized in that the support portion is a folded edge (42) of the one-way valve (40), the folded edge (42) extending radially inside the body portion (41) and abutting a radially inside surface of the cavity (24).

4. An oil control valve according to claim 3, wherein said check valve (40) has two said folded edges (42), and said two folded edges (42) are respectively bent from both axial ends of said main body portion (41) toward each other.

5. An oil control valve according to claim 1, characterized in that the one-way valve (40) axially abuts the closed end of the cavity (24).

6. The oil control valve of claim 1, wherein said valve housing (20) has a first end that is open and a second end that is closed, said first end being axially opposite said second end, said cavity (24) having an open end facing said second end of said valve housing (20).

7. An oil control valve according to claim 1, characterized in that the housing (10) has a stop portion which axially abuts an end of the check valve (40) close to the open end of the cavity (24) so as to restrain the check valve (40) in the cavity (24).

8. The oil control valve according to any one of claims 1 to 7, wherein the valve sleeve (20) includes a core portion (27) and a clad portion (28), the clad portion (28) being clad radially outside the core portion (27), the cavity (24) being located radially between the core portion (27) and the clad portion (28).

9. Machine oil control valve according to claim 8, characterized in that the sleeve core portion (27) is made of a metal material and the clad portion (28) is made of a plastic material.

10. Machine oil control valve according to claim 9, characterized in that the valve sleeve (20) is manufactured by an overmoulding process.

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