Cam phase adjuster

Abstract

The present application relates to a cam phase regulator. The cam phase regulator includes a stator, a rotor rotatably installed at a radially inner side of the stator, and an oil control valve installed at a radially inner side of the rotor, the oil control valve including a valve body having an outer circumferential surface abutting an inner circumferential surface of the rotor, the rotor having a first flow passage and a second flow passage, the valve body having a first hole and a second hole spaced apart in an axial direction, the first hole communicating with the first flow passage, the second hole communicating with the second flow passage, wherein the valve body has an annular groove formed on the outer circumferential surface, and the first flow passage communicates with the first hole through the annular groove. The cam phase regulator of the present application is easy to process.

Description

Technical Field

[0001] This invention relates to the field of engine technology. Specifically, this invention relates to a cam phase adjuster for an engine. Background Technology

[0002] In modern vehicle internal combustion engines, a Variable Valve Timing (VVT) system is typically used to change the phase relationship between the crankshaft and camshaft between advanced and retarded positions. This adjusts the valve opening and closing times and intake and exhaust volumes to achieve optimal combustion efficiency. The main component of the VVT ​​system is the camshaft phase adjuster, which contains multiple hydraulic chambers. These chambers allow for targeted changes in the phase relationship between the crankshaft and camshaft through the inflow and outflow of hydraulic fluid. Furthermore, an oil control valve is installed in the camshaft phase adjuster to control the flow of hydraulic fluid into and out of the hydraulic chambers.

[0003] For example, CN 109538323A discloses a cam phase adjuster with a typical structure. The centrally located oil control valve of this cam phase adjuster includes a valve body, a valve sleeve, and a valve core nested sequentially. A first and second oil hole are formed radially through the valve body. The two oil holes are respectively connected to corresponding hydraulic passages in the rotor, thereby introducing oil into the hydraulic chambers on both sides of the rotor blades.

[0004] Because the oil holes on the valve body and the openings of the flow channels on the rotor are often difficult to align circumferentially, annular grooves communicating with the two flow channels need to be formed on the radially inner side of the rotor to connect them. These annular grooves connect the circumferentially misaligned oil holes to the flow channels. Since the powder metallurgy green blank processing technology for manufacturing rotors can only form structures with a unidirectionally decreasing diameter, the annular grooves need to be machined separately in subsequent processes. This results in higher production costs, and the surface quality produced in this way is not ideal. Summary of the Invention

[0005] Therefore, the technical problem that this invention needs to solve is to provide a cam phase adjuster that is easy to manufacture.

[0006] The aforementioned technical problem is solved by a cam phase adjuster according to the present invention. The cam phase adjuster includes a stator, a rotor, and an oil control valve. The rotor is rotatably mounted radially inside the stator, and the oil control valve is mounted radially inside the rotor. The oil control valve includes components such as a valve body, the outer peripheral surface of which abuts against the inner peripheral surface of the rotor. The rotor has a first flow channel and a second flow channel for respectively communicating with two different hydraulic chambers on both sides of the rotor blades. The valve body has a first hole and a second hole spaced apart axially, the first hole communicating with the first flow channel and the second hole communicating with the second flow channel. The valve body has an annular groove formed on its outer peripheral surface, and the first flow channel communicates with the first hole through the annular groove.

[0007] The orifice on the valve body and the opening of the flow channel on the rotor are usually not aligned circumferentially. To connect them, an annular channel needs to be formed between the valve body and the rotor. The first flow channel and the first orifice are connected by an annular groove formed on the outer circumferential surface of the valve body, meaning that at least one of these channels does not need to be formed by cutting the inner circumferential surface of the rotor. Therefore, no intermediate protrusion structure sandwiched between the cut portions of the two annular channels is formed on the inner circumferential surface of the rotor, and the inner diameter of the rotor can decrease unidirectionally in the axial direction. This allows the rotor to be demolded and formed in one step during the powder metallurgy green blank processing, reducing secondary processing steps and thus saving manufacturing costs. This structure is commonly used in center-type oil control valves, so the valve body can be arranged coaxially with the rotor.

[0008] According to a preferred embodiment of the invention, the valve body may have a first end extending axially beyond the rotor and a threaded section formed on the outer peripheral surface of the first end. The threaded section is used for connection with a camshaft, thereby adjusting the phase of the camshaft. The first hole is closer to the first end than the second hole. In this case, the annular groove connecting the first flow channel and the first hole preferably extends axially to the end of the threaded section. This is because after the threads are extruded onto the outer peripheral surface of the valve body, an annular groove formed of extruded material is typically generated at the end of the threaded section. Directly expanding this annular groove to form the annular groove connecting the first flow channel and the first hole reduces the difficulty and cost of processing.

[0009] According to another preferred embodiment of the invention, the rotor may have a stepped portion located at the end of the inner circumferential surface of the rotor away from the first end of the valve body. The valve body has a second end extending axially beyond the rotor and a flange extending radially outward from the outer circumferential surface of the second end, the second end of the valve body being opposite to the first end. The flange of the valve body abuts against the end face of the rotor axially, thereby defining an annular channel connecting the second flow channel and the second hole between the flange, the stepped portion, and the outer circumferential surface of the valve body. Since this annular channel is formed jointly by the stepped portion of the rotor and the flange of the valve body, the machining of an annular groove on the inner circumferential surface of the rotor is again avoided. Furthermore, the stepped portion located at the end of the inner circumferential surface allows the rotor to maintain a unidirectional decreasing inner diameter structure. Therefore, the stepped portion can be demolded in one step during the greening process of the rotor, further reducing the process steps and saving processing costs.

[0010] According to another preferred embodiment of the invention, the opening of the first hole toward the rotor and / or the opening of the first flow channel toward the valve body can fall completely into the annular groove of the valve body. Correspondingly, the opening of the second flow channel toward the valve body and / or the opening of the second hole toward the rotor can also fall completely into the annular channel. Attached Figure Description

[0011] The invention is further described below with reference to the accompanying drawings. In the drawings, the same reference numerals represent elements with the same function. Wherein:

[0012] Figure 1 A partial cross-sectional view of a cam phase adjuster according to an embodiment of the present invention is shown. Detailed Implementation

[0013] The following describes specific embodiments of the cam phase adjuster according to the present invention with reference to the accompanying drawings. The detailed description and drawings below are provided to illustrate the principles of the invention, and the invention is not limited to the described preferred embodiments; the scope of protection of the invention is defined by the claims.

[0014] According to an embodiment of the present invention, a cam phase adjuster for an engine of a motor vehicle is provided. Figure 1 A cam phase adjuster according to an embodiment of the present invention is shown. The cam phase adjuster includes a stator, a rotor 10, and an oil control valve arranged coaxially. The rotor is rotatably mounted radially inside the stator, and the oil control valve is mounted at the center of the rotor. The oil control valve includes a valve body 20, a valve sleeve, and a valve core arranged coaxially. The valve body 20, valve sleeve, and valve core are all generally cylindrical, with the valve body 20 mounted radially outside the valve sleeve, and the valve sleeve mounted radially outside the valve core. The outer peripheral surface of the valve body 20 abuts against the inner peripheral surface of the rotor 10.

[0015] For ease of explanation, only the rotor 10 and valve body 20 are shown in the figure. The valve body 20 has a first end 21 and a second end 22 opposite to each other in the axial direction. The first end 21 and the second end 22 extend from opposite directions beyond the axial end face of the rotor 10.

[0016] A threaded section 23 is formed on the outer peripheral surface of the valve body 20 at the first end 21. The camshaft 30 is fixed radially outward of the first end 21 via the threaded section 23. The axial end face of the camshaft 30 abuts against the axial end face of the rotor 10. The threaded section 23 is formed by an extrusion process, so the extruded metal material after threading forms a narrow annular groove at the end of the threaded section 23 near the rotor 10. By expanding this annular groove toward the rotor 10, a wider annular groove 24 is formed, as shown in the figure. The annular groove 24 extends axially from the end of the threaded section 23 into the interior of the rotor 10. The inner peripheral surfaces of the rotor 10 and the camshaft 30 together close the annular groove 24.

[0017] A flange 25 extending radially outward is formed on the outer peripheral surface of the valve body 20 at the second end 22. The flange 25 abuts against the other axial end face of the rotor 10. A stepped portion 11 is formed on the inner peripheral surface of the rotor 10 near the flange 25. The stepped portion 11 of the rotor 10, together with the outer peripheral surface of the valve body 20 and the flange 25, defines an annular channel. Because the stepped portion 11 makes the inner diameter of the rotor 10 still a unidirectionally decreasing structure in the axial direction, the stepped portion 11 can be demolded and formed in one step during the greening process of the rotor 10 without the need for additional processing steps.

[0018] The valve body 20 has a plurality of first holes 26 and a plurality of second holes 27 radially penetrating its sidewalls. The plurality of first holes 26 are evenly distributed circumferentially, and the plurality of second holes 27 are also evenly distributed circumferentially. The first holes 26 and second holes 27 are axially spaced apart, and the first holes 26 are closer to the first end 21 of the valve body 20 than the second holes 27. Each first hole 26 communicates with an annular groove 24, and preferably, the opening of each first hole 26 facing the rotor 10 falls completely into the annular groove 24. Correspondingly, each second hole 27 communicates with an annular channel, and preferably, the opening of each second hole 27 facing the rotor 10 falls completely into the annular channel. The rotor 10 has a first flow channel 12 and a second flow channel 13. The first flow channel 12 communicates the annular groove 24 with a hydraulic chamber (not shown) on one side of the rotor blade (not shown), and preferably, the opening of the first flow channel 12 facing the valve body 20 falls completely into the annular groove 24. The second flow channel 13 connects the annular channel to the hydraulic chamber (not shown) on the other side of the rotor blade, and preferably, the opening of the second flow channel 13 toward the valve body 20 also falls completely into the annular channel.

[0019] According to an embodiment of the present invention, the cam phase adjuster can demold the rotor 10 in one go, and can use the existing structure in the existing processing technology to form the annular groove on the valve body 20. Therefore, the processing technology is simple, the production cost is low, and the processing accuracy of the component surface can be improved.

[0020] While possible embodiments have been described exemplarily in the foregoing description, it should be understood that numerous variations of embodiments exist through combinations of all known and readily conceived technical features and implementation methods. Furthermore, it should be understood that the exemplary embodiments are merely examples and do not in any way limit the scope, application, or construction of the invention. The foregoing description is more intended to provide those skilled in the art with technical guidance for transforming at least one exemplary embodiment, wherein various changes, particularly regarding the function and structure of the components, can be made without departing from the scope of the claims.

[0021] Appendix Label Table

[0022] 10 rotors

[0023] 11. Step section

[0024] 12 First Flow Channel

[0025] 13 Second Flow Channel

[0026] 20 Valve body

[0027] 21 First End

[0028] 22 Second End

[0029] 23 Threaded section

[0030] 24 Annular Groove

[0031] 25 flange

[0032] 26 First Hole

[0033] 27 Second Hole

[0034] 30 Camshaft

Claims

1. A cam phase adjuster, comprising a stator, a rotor (10), and an oil control valve, the rotor (10) being rotatably mounted radially inside the stator, the oil control valve being mounted radially inside the rotor (10), the oil control valve comprising a valve body (20), the outer peripheral surface of the valve body (20) abutting an inner peripheral surface of the rotor (10), the rotor (10) having a first flow channel (12) and a second flow channel (13), the valve body (20) having a first hole (26) and a second hole (27) spaced apart axially, the first hole (26) communicating with the first flow channel (12), the second hole (27) communicating with the second flow channel (13), the valve body (20) having a first end (21) extending axially beyond the rotor (10) and a threaded section (23) formed on the outer peripheral surface of the first end (21), the threaded section (23) being for connection with a camshaft (30). Its features are, The valve body (20) has an annular groove (24) formed on its outer peripheral surface, through which the first flow channel (12) and the first hole (26) communicate. The rotor (10) has a stepped portion (11) located at the end of the inner peripheral surface of the rotor (10) away from the first end (21). The valve body (20) has a second end (22) extending axially beyond the rotor (10) and a flange (25) extending radially outward from the outer peripheral surface of the second end (22). The second end (22) is opposite to the first end (21), and the flange (25) abuts axially against the end face of the rotor (10), thereby defining an annular channel between the flange (25), the stepped portion (11), and the outer peripheral surface of the valve body (20) that communicates the second flow channel (13) and the second hole (27).

2. The cam phase adjuster according to claim 1, characterized in that, The first hole (26) is closer to the first end (21) than the second hole (27).

3. The cam phase adjuster according to claim 2, characterized in that, The annular groove (24) extends axially to the end of the threaded section (23).

4. The cam phase adjuster according to claim 1, characterized in that, The opening of the first hole (26) facing the rotor (10) falls completely into the annular groove (24).

5. The cam phase adjuster according to claim 1, characterized in that, The opening of the first flow channel (12) facing the valve body (20) falls completely into the annular groove (24).

6. The cam phase adjuster according to claim 1, characterized in that, The opening of the second flow channel (13) facing the valve body (20) falls completely into the annular channel.

7. The cam phase adjuster according to claim 1, characterized in that, The opening of the second hole (27) facing the rotor (10) falls completely into the annular channel.

8. The cam phase adjuster according to any one of claims 1 to 7, characterized in that, The valve body (20) is arranged coaxially with the rotor (10).

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