Center-mounted intermediate locking phaser

Abstract

The present invention relates to a central intermediate locking phaser, which relates to the technical field of engines. The central intermediate locking phaser of the present invention includes a sprocket, a locking pin seat, a stator, a rotor, a locking pin assembly, a one-way valve assembly, a front cover, and a planar spiral structure return spring; the sprocket is provided with a sprocket groove and a sprocket pin hole groove, and the first blade of the rotor is provided with a locking pin round hole, a left stepped one-way valve hole, a right stepped one-way valve hole and their mating structures, which expands the range of large-angle control realized by the VVT, and the initial position of the VVT is set in the middle of the condition range, and the adjustment in both the advance and retard directions can respond quickly; it solves the requirements for the phase compatibility of cold start and Atkinson cycle, and can also reach the retard phase required by the Atkinson cycle relatively quickly.

Description

Technical Field

[0001] The present invention relates to the technical field of engines, and more specifically, the present invention relates to a central locking phaser of a variable valve timing system. Background Art

[0002] At high engine speeds, more air is required, but the intake valve may close before all the required air has entered, resulting in reduced performance. Therefore, the timing of valve opening and closing is very important. A continuously open valve will cause fuel to be discharged from the engine without being burned, which will reduce the performance of the engine and increase exhaust pollution. Therefore, the engine idle speed cannot be too low. The crankshaft drives the camshaft through a timing belt, gears or a chain. The profile and position of the cams on the camshaft are usually optimized for a specific engine speed. Usually, this will reduce the torque at low engine speeds and the power at high engine speeds. VVT technology enables it to be changed according to the engine operating conditions, improving the efficiency and power of the engine.

[0003] The principle of Variable Valve Timing (VVT) technology is to adjust the amount of intake or exhaust air, the opening and closing time, and the angle of the valves according to the operating conditions of the engine, so as to achieve the best amount of air intake, improve the combustion efficiency of the engine, improve its power performance and increase fuel economy. VVT technology not only enables the engine to have better torque transmission characteristics and lower fuel consumption under partial load, but also can significantly improve the comprehensive performance of the engine at high and low speeds, and under large and small loads. The variable valve cam phaser is the most commonly used component in VVT technology.

[0004] Chinese Patent CN106150587B discloses a central variable valve timing device, in which the phaser includes a stator, a rotor, and a cover plate. The stator, rotor, and cover plate cooperate to form more than two sealing cavities. The rotor has sealing arms, and the sealing arms evenly divide the corresponding sealing cavities into an advance cavity and a retard cavity. The rotor is provided with two locking pins, and two arc-shaped grooves are formed on the cover plate. Two locking members abut against adjacent ends of the two arc-shaped grooves; it has the advantages of simple structure, convenient use, and double-locking function, with the oil control valve in the center, fast adjustment response speed, small oil pressure loss, and high fuel economy; however, the reset action response of the phaser is slow, and the mating part between the rotor and the stator is prone to wear under adverse working conditions.

[0005] The Chinese invention patent application publication text CN106703925A discloses a high-precision rotor for automotive VVT, and the Chinese invention patent CN105234411B discloses a powder metallurgy phaser rotor for engine VVT made of aluminum alloy material. Although it can improve production efficiency and reduce costs, its high-temperature resistance performance is still insufficient. Under long-term use conditions, the adjustment accuracy may deteriorate. Moreover, with the continuous enhancement of market competition in the automotive industry, most of the current mainstream passenger vehicle manufacturing industries have achieved or are developing engines with a thermal efficiency of more than 40%. To achieve this thermal efficiency goal, most adopt the Atkinson cycle technology. The Atkinson cycle requires the intake valve to close significantly late, and the late closing of the intake valve is not conducive to the cold start of the engine. The VVT phaser in the prior art cannot simultaneously meet the requirements of cold start and the Atkinson cycle for the phase; limited by the existing structure, the time required for the VVT in the prior art to adjust from the most advanced position to the most retarded position is relatively long, and it is difficult to ensure the transient accuracy; thus, the existing VVT phasers are difficult to fully meet the requirements of the Atkinson cycle for phase adjustment. Summary of the Invention

[0006] In order to solve the above problems in the existing clinical technology, the purpose of the present invention is to provide a center-mounted intermediate locking phaser.

[0007] The center-mounted intermediate locking phaser of the present invention includes a sprocket, a locking pin seat, a stator, a rotor, a front cover, and a planar spiral structure return spring; it is characterized in that: the sprocket has a disc-shaped sprocket body, and a non-through sprocket groove is provided on the sprocket body, and a non-through sprocket pin hole groove is provided on the inner side of the sprocket groove; the rotor is coaxially arranged in the stator; the stator includes a stator cylinder body, and three stator bosses are provided on the inner side of the stator cylinder body; the locking pin seat is arranged in the sprocket pin hole groove of the sprocket; the rotor includes a rotor body and a first blade, a second blade, and a third blade arranged on the outer side of the rotor body; an advance chamber and a retard chamber are respectively formed between the first blade, the second blade, and the third blade and the adjacent stator bosses; a camshaft bolt hole is provided at the center of the rotor, and a first annular groove, a second annular groove, and a third annular groove are provided in the camshaft bolt hole; the second annular groove is communicated with the retard chamber through a retard chamber side oil hole, the third annular groove is communicated with the advance chamber through an advance chamber side oil hole, and the first annular groove is communicated with the sprocket pin hole groove through a rotor unlocking oil hole; left and right grooves are symmetrically arranged on both sides of the first blade, a left groove side hole is provided in the left groove, a right groove side hole is provided in the right groove, and a locking pin round hole, a left stepped one-way valve hole, and a right stepped one-way valve hole parallel to the axial direction are further provided on the first blade.

[0008] Among them, the left stepped one-way valve hole and the right stepped one-way valve hole are arranged on both sides of the lock pin round hole in a symmetric or asymmetric manner. A left stepped one-way valve hole side groove is arranged on the outer side of the left stepped one-way valve hole, and the left stepped one-way valve hole side groove communicates with the left stepped one-way valve hole; a right stepped one-way valve hole side groove is arranged on the outer side of the right stepped one-way valve hole, and the right stepped one-way valve hole side groove communicates with the right stepped one-way valve hole; the left groove side hole penetrates the lock pin round hole, and the right groove side hole penetrates the lock pin round hole; a one-way valve assembly is arranged in the left stepped one-way valve hole and the right stepped one-way valve hole, and a lock pin assembly is arranged in the lock pin round hole; when the phaser is in the initial position, the lock pin round hole is aligned with the sprocket pin hole groove.

[0009] Among them, the front cover is arranged at the front end of the rotor, and the sprocket is arranged at the rear end of the rotor. The sprocket, the stator and the front cover are connected by fasteners.

[0010] Among them, the planar spiral structure return spring is arranged on the upper end surface of the front cover. The planar spiral structure has an outer ring and an inner ring, and the outer ring and the inner ring are limited and supported by a positioning rod.

[0011] Among them, the one-way valve assembly is composed of a one-way valve disc, a one-way valve spring and a one-way valve base; the one-way valve base has a stepped seat with a cylindrical structure, and the one-way valve spring is sleeved on the cylindrical structure of the one-way valve base.

[0012] Among them, the one-way valve disc is close to the rear ends of the left stepped one-way valve hole and the right stepped one-way valve hole, the one-way valve base is close to the front ends of the left stepped one-way valve hole and the right stepped one-way valve hole, and the one-way valve spring is arranged between the one-way valve disc and the one-way valve base.

[0013] Among them, the lock pin assembly is composed of a locking pin, a locking spring and a locking spring seat.

[0014] Among them, the locking pin has a long cylindrical structure, and there is an annular concave structure in the middle of the long cylindrical structure; the locking spring is arranged between the groove at the front end of the locking pin and the locking spring seat.

[0015] Among them, an axial round hole is arranged at the center of the sprocket body, teeth are arranged on the outer ring of the sprocket body, and a plurality of axial threaded holes are arranged on the sprocket body.

[0016] Among them, bolt through holes are respectively arranged on the three stator bosses.

[0017] Among them, the front cover has a disc-shaped structure. An axially shaped hole is provided at the center inside the front cover, and a plurality of axially tapered threaded counterbores are provided on the front cover. Screws pass through the axially tapered threaded counterbores, bolt through-holes, and threaded holes to screw and fix the front cover, stator, and sprocket; a long groove or hole structure penetrating axially is provided at the edge of the front cover. The first positioning rod passes through the long groove or hole structure and is riveted and fixed to the stator for limiting the outer ring of the planar spiral structure return spring.

[0018] Among them, the second positioning rod and the third positioning rod pass through the central through-hole of the front cover and are press-riveted and fixed to the rotor for limiting and supporting the inner ring of the planar spiral structure return spring.

[0019] Among them, the locking pin seat is a metal bushing, and the locking pin seat is press-riveted and fixed to the sprocket; the locking pin seat is quenched and has an annular structure, and the inside of the annular structure has an elliptical center.

[0020] Among them, the sprocket groove is a C-shaped groove.

[0021] Among them, the sprocket and the stator are of an integral structure.

[0022] Compared with the prior art, the in-line intermediate locking phaser of the present invention has the following beneficial effects:

[0023] The phaser of the present invention can be adjusted in both the advance chamber and the retard chamber directions, expanding the range of large-angle control that VVT can achieve. And the initial position of VVT is set in the middle of the condition range, and the adjustment in both the advance and retard directions can respond quickly; it solves the requirements for phase compatibility of cold start and Atkinson cycle, and can also reach the retard phase required by the Atkinson cycle relatively quickly. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is an assembly structure diagram of the in-line intermediate locking phaser of the present invention;

[0025] Figure 2 is an exploded structure diagram of the in-line intermediate locking phaser of the present invention;

[0026] Figure 3 is a schematic structural diagram of the rotor in the in-line intermediate locking phaser of the present invention;

[0027] Figure 4 is a sectional structure diagram of the in-line intermediate locking phaser of the present invention;

[0028] Figure 5 is a perspective view of the in-line intermediate locking phaser of the present invention.

[0029] The meanings represented by the respective reference numerals in the figures are as follows:

[0030] 10 - sprocket, 11 - sprocket body, 12 - sprocket groove, 13 - sprocket pin hole groove; 20 - locking pin seat; 30 - stator, 31 - stator cylinder, 32 - stator boss, 33 - advance chamber, 34 - advance chamber side oil hole, 35 - retard chamber, 36 - retard chamber side oil hole, 37 - stator bolt through hole; 40 - locking pin assembly, 41 - locking pin, 42 - locking spring, 43 - locking spring seat; 50 - one - way valve assembly, 51 - one - way valve disc, 52 - one - way valve spring, 53 - one - way valve base; 60 - front cover; 70 - planar spiral structure return spring; 80 - rotor, 81 - first vane, 82 - second vane, 83 - third vane, 84 - left groove, 85 - left groove side hole, 86 - locking pin round hole, 87 - right groove side hole, 88 - right groove, 89 - left stepped one - way valve hole, 90 - right stepped one - way valve hole, 91 - left stepped one - way valve hole side groove, 92 - right stepped one - way valve hole side groove, 93 - camshaft bolt hole, 95 - rotor unlocking oil inlet hole, 96 - first annular groove, 97 - second annular groove, 98 - third annular groove, 101 - first positioning rod, 102 - second positioning rod, 103 - third positioning rod, 105 - screw. Detailed implementation manners

[0031] The following will further elaborate on the in - center intermediate locking phaser of the present invention in combination with specific embodiments to help those skilled in the art have a more complete, accurate and in - depth understanding of the technical solution of the present invention.

[0032] As Figures 1-5As shown in the figure, the center-mounted intermediate locking phaser of this embodiment includes a sprocket 10, a locking pin seat 20, a stator 30, a rotor 80, a locking pin assembly 40, a one-way valve assembly 50, a front cover 60, a planar spiral structure return spring 70, a first positioning rod 101, a second positioning rod 102, a third positioning rod 103, and a screw 105. The sprocket 10 has a disc-shaped sprocket body 11. An axial circular hole is provided at the center of the sprocket body 11. Teeth are provided on the outer ring of the sprocket body 11. A plurality of axial threaded holes are provided on the sprocket body 11. And a non-through sprocket groove 12 is provided on the sprocket body 11, preferably a C-shaped groove. A non-through sprocket pin hole groove 13 is provided on the inner side of the sprocket groove. The rotor 80 is coaxially arranged inside the stator 30. The front cover 60 is arranged at the front end of the rotor 80, and the sprocket 10 is arranged at the rear end of the rotor 80. The planar spiral structure return spring 70 is arranged at the upper end surface of the front cover 60 and has a planar spiral structure. The planar spiral structure has an outer ring and an inner ring, and the outer ring and the inner ring are limited and supported by positioning rods (the first positioning rod 101 passes through the through groove on the outer side of the front cover 60 and cooperates with the stator 30 to limit and support the outer ring of the planar spiral structure return spring 70; the second positioning rod 102 and the third positioning rod 103 pass through the front cover 60 and cooperate with the rotor 80 to limit and support the inner ring of the planar spiral structure return spring 70). The stator 30 includes a stator cylinder 31. Three stator bosses are provided on the inner side of the stator cylinder 31. Bolt through holes are respectively provided on the three stator bosses. The sprocket 10, the stator 30, and the front cover 60 are positioned by positioning pins and connected by fasteners. In this embodiment, the fasteners are 3 screws 105. Specifically, the front cover 60 has a disc-shaped structure. An axial special-shaped hole is provided at the center of the inside of the front cover 60, and a plurality of axial tapered threaded counterbores are provided on the front cover 60. The screw 105 passes through the axial tapered threaded counterbore, the bolt through hole, and the threaded hole of the sprocket body 11 and is screwed and fixed to the sprocket 10. The locking pin seat 20 is arranged in the sprocket pin hole groove 13 of the sprocket 10, and the locking pin seat 20 has an annular structure. The inside of the annular structure has an elliptical center, and the major axis direction of the elliptical center points to the sprocket center. The locking pin seat is a metal bushing, which is press riveted and fixed to the sprocket. To ensure strength and avoid wear, the locking pin seat must be quenched.

[0033] The rotor 80 includes a rotor body and a first vane 81, a second vane 82, and a third vane 83 arranged on the outer side of the rotor body; the first vane 81, the second vane 82, and the third vane 83 respectively form an advance chamber 33 and a retard chamber 35 with the adjacent bosses (see Figure 5 ) Figure 5Only the advance chamber 33 and the lag chamber 35 formed between the first blade 81 and the adjacent boss are marked out, as shown in Fig. 5. The second blade and the third blade also form an advance chamber 33 and a lag chamber 35 with the adjacent boss. The volume of the first blade is larger than that of the second blade 82 and the third blade 83. Referring to the attached Figures 3-5 As shown, a camshaft bolt hole 93 is provided at the center of the rotor 80. The camshaft bolt hole 93 is used to connect to a camshaft and the camshaft bolt hole 93 is provided with a first annular groove 96, a second annular groove 97 and a third annular groove 98. The second annular groove 97 communicates with the lag chamber 35 through a lag chamber side oil hole 36. The third annular groove 98 communicates with the advance chamber 33 through an advance chamber side oil hole 34. The first annular groove 96 communicates with the sprocket pin hole groove 13 through a rotor unlocking oil inlet hole 95. On both sides of the first blade 81, a left groove 84 and a right groove 88 are symmetrically provided. A left groove side hole 85 is provided in the left groove 84, and a right groove side hole 87 is provided in the right groove 88. A lock pin round hole 86 parallel to the axial direction, a left stepped check valve hole 89 and a right stepped check valve hole 90 are also provided on the first blade. The left stepped check valve hole 89 and the right stepped check valve hole 90 are symmetrically arranged on both sides of the lock pin round hole 86. A left stepped check valve hole side groove 91 is provided outside the left stepped check valve hole 89, and the left stepped check valve hole side groove 91 communicates with the left stepped check valve hole 89. A right stepped check valve hole side groove 92 is provided outside the right stepped check valve hole 90, and the right stepped check valve hole side groove 92 communicates with the right stepped check valve hole 90. The left groove side hole 85 penetrates through the lock pin round hole 86, and the right groove side hole 87 penetrates through the lock pin round hole 86.

[0034] The check valve assembly 50 is composed of a check valve piece 51, a check valve spring 52 and a check valve base 53. The check valve base 53 has a stepped seat with a cylindrical structure. The check valve spring 52 is sleeved on the cylindrical structure of the check valve base 53. There are two check valve assemblies 50, which are respectively arranged in the left stepped check valve hole 89 and the right stepped check valve hole 90. The check valve piece 51 is close to the rear ends of the left stepped check valve hole 89 and the right stepped check valve hole 90. The check valve base 53 is close to the front ends of the left stepped check valve hole 89 and the right stepped check valve hole 90. The check valve spring 52 is arranged between the check valve piece 51 and the check valve base 53.

[0035] The lock pin assembly 40 is composed of a locking pin 41, a locking spring 42, and a locking spring seat 43. The locking pin 41 is disposed within the lock pin round hole 86. The locking pin 41 has a long cylindrical structure, and an annular concave structure is provided in the middle of the long cylindrical structure. The locking spring 42 is disposed between the groove at the front end of the locking pin 41 and the locking spring seat 43. When the phaser is in the initial position, the lock pin round hole 86 is aligned with the sprocket pin hole groove 13.

[0036] In the present invention, the designed rotor is an aluminum alloy powder sintered part, which can be processed and formed by powder metallurgy technology. The elemental composition of the aluminum alloy is as follows: 3.60 - 3.90 wt% of Cu, 1.15 - 1.35 wt% of Li, 0.25 - 0.50 wt% of Mn, 0.01 - 0.10 wt% of Nb, 0.10 - 0.15 wt% of Zr, 0.03 - 0.10 wt% of Ti, and the balance is Al and inevitable impurities, and the content of inevitable impurities is more than 1.0 wt%. The aluminum alloy powder sintered part is mixed according to the above elemental composition, and 1.0% of polyamide and 0.5% of paraffin are added based on the total amount of the aluminum alloy raw materials and mixed evenly; then warm compaction molding is carried out at 130 °C and a molding pressure of 120 - 180 MPa to obtain a green body, and then sintering is carried out at 600 - 610 °C for 60 min in an inert gas atmosphere. After sintering, sandblasting is carried out and secondary solution treatment is carried out, holding for 1 h at 480 - 500 °C, holding for 2 h at 520 - 540 °C, and finally aging treatment is carried out at 150 - 160 °C for 30 hours. The tensile strength of the aluminum alloy powder sintered part is 420 - 450 MPa, and the HRB hardness can reach more than 78, having excellent mechanical properties.

[0037] For the center-mounted intermediate locking phaser of the present invention, when the engine ECU gives an unlocking action signal, the oil pressure flows through the first annular groove 96 of the camshaft bolt hole 93 on the rotor 80 to the rotor unlocking oil inlet hole 95 and enters the sprocket pin hole groove 13. Oil pressure is generated at the bottom of the locking pin, and the locking pin overcomes the locking spring and lifts upward to complete the unlocking function. At this time, the engine oil in the advance chamber 33 and the retard chamber 35 of the phaser cannot be discharged through the engine oil control valve, and the engine phase remains unchanged. When the engine ECU gives a phase advance action signal, the oil pressure flows through the third annular groove 98 of the rotor camshaft bolt hole 93 to the advance chamber side oil hole 34 and enters the advance chamber 33. The rotor 80 is affected by the oil pressure, and the phaser moves toward the advance chamber. At this time, the retard chamber 35 discharges oil, and the engine oil flows to the valve sleeve drain hole and then out from the bolt flange surface. When the engine ECU gives a phase stabilization action signal, the engine oil control valve controls the oil circuits of both the advance chamber 33 and the retard chamber 35 to be closed to achieve the phase stabilization target value. When the engine ECU gives a phase retard action signal, the oil pressure flows through the second annular groove 97 of the rotor camshaft bolt hole 93 to the retard chamber side oil hole 36 and enters the retard chamber 35. The rotor 80 is affected by the oil pressure, and the phaser moves toward the retard chamber 35. At this time, the advance chamber 33 of the phaser discharges oil, and the engine oil flows to the valve sleeve drain hole and then out from the bolt flange surface. When the engine stops and the phaser needs to perform a reset action, there are two cases for the phaser: (1) When the phase is in the advance position, the rotor 80 is affected by the camshaft torque and is forced in the retard direction. At this time, the engine oil in the advance chamber 33 and the retard chamber 35 of the phaser cannot be discharged through the engine oil control valve. Therefore, the engine oil flows from the advance chamber 33 through the sprocket groove 12 to the left groove 84 provided outside the first vane 81 of the rotor 80, then to the locking pin round hole 86, lifting the check valve disc 51 of the check valve assembly 50 on the right side of the rotor 80. The engine oil flows to the side groove 92 of the right stepped check valve hole and then to the retard chamber 35, realizing the movement of the rotor 80 in the retard direction, thereby achieving the reset of the engine stop locking pin. (2) When the phase is in the retard position, at this time, the engine oil in the advance chamber 33 and the retard chamber 35 of the phaser cannot be discharged through the engine oil control valve. The rotor 80 is affected by the spring torque and is forced in the advance direction. The engine oil in the retard chamber 35 flows through the sprocket groove 12 to the locking pin round hole 86, lifting the check valve disc 51 of the check valve assembly 50 on the left side of the rotor 80. The engine oil flows to the side groove 91 of the left stepped check valve hole and then to the advance chamber 33, realizing the movement of the rotor 80 in the advance direction, thereby achieving the reset of the engine stop locking pin.

[0038] In addition to the oil circuits of the advance chamber 33 and the retard chamber 35, the center-mounted intermediate locking phaser of the present invention adds an additional oil circuit for actively controlling unlocking or locking through the design and improvement of the sprocket 10 and the rotor 80. At the same time, through the internal oil circuit circulation function, after the rotor 80 is adjusted to any phase, it can still quickly lock to the intermediate initial position. The phaser of the present invention can be adjusted in both directions of the advance chamber 33 and the retard chamber 35, expanding the range of large-angle control that VVT can achieve. Moreover, the initial position of VVT is set in the middle of the condition range, and the adjustment in both the advance and retard directions can respond quickly, solving the requirements for the phase compatibility of cold start and the Atkinson cycle, and at the same time, it can also relatively quickly reach the retard phase required by the Atkinson cycle.

[0039] For those of ordinary skill in the art, the specific embodiments only exemplarily describe the present invention. Obviously, the specific implementation of the present invention is not limited by the above-mentioned methods. As long as various non-substantive improvements are made by adopting the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A centrally mounted intermediate locking phaser, comprising a sprocket, a locking pin seat, a stator, a rotor, a front cover and a planar spiral structure return spring; characterized in that: The sprocket has a disc-shaped sprocket body, a non-through sprocket groove is provided on the sprocket body, and a non-through sprocket pin hole groove is provided on the inner side of the sprocket groove; the rotor is coaxially arranged in the stator; the stator includes a stator cylinder, and three stator bosses are provided on the inner side of the stator cylinder; the locking pin seat is arranged in the sprocket pin hole groove of the sprocket; the rotor includes a rotor body and a first blade, a second blade and a third blade arranged on the outer side of the rotor body; the first blade, the second blade and the third blade respectively form an advance chamber and a lag chamber with adjacent stator bosses; the center of the rotor is provided with a convex The wheel shaft bolt hole, the camshaft bolt hole is provided with a first annular groove, a second annular groove and a third annular groove; the second annular groove is connected with the retardation chamber through the retardation chamber side oil hole, the third annular groove is connected with the advance chamber through the advance chamber side oil hole, the first annular groove is connected with the sprocket pin hole groove through the rotor unlocking oil inlet hole; the first blade is symmetrically provided with a left groove and a right groove on both sides, the left groove is provided with a left groove side hole, the right groove is provided with a right groove side hole, and the first blade is also provided with a locking pin circular hole parallel to the axial direction, a left stepped one-way valve hole and a right stepped one-way valve hole.

2. The centrally mounted intermediate locking phaser according to claim 1, characterized in that: The left stepped one-way valve hole and the right stepped one-way valve hole are symmetrically or asymmetrically arranged on both sides of the locking pin circular hole, and a left stepped one-way valve hole side groove is arranged on the outer side of the left stepped one-way valve hole, and the left stepped one-way valve hole side groove is communicated with the left stepped one-way valve hole; a right stepped one-way valve hole side groove is arranged on the outer side of the right stepped one-way valve hole, and the right stepped one-way valve hole side groove is communicated with the right stepped one-way valve hole; the left groove side hole passes through the locking pin circular hole, and the right groove side hole passes through the locking pin circular hole; a one-way valve assembly is arranged in the left stepped one-way valve hole and the right stepped one-way valve hole, and a locking pin assembly is arranged in the locking pin circular hole; when the phaser is in the initial position, the locking pin circular hole is directly opposite to the sprocket pin hole groove.

3. The centrally mounted intermediate locking phaser according to claim 2, characterized in that: The front cover is arranged at the front end of the rotor, the sprocket is arranged at the rear end of the rotor, and the sprocket, the stator and the front cover are connected by fasteners.

4. The centrally mounted intermediate locking phaser according to claim 3, characterized in that: The planar spiral structure return spring is arranged at the upper end surface of the front cover, the planar spiral structure has an outer ring and an inner ring, and the outer ring and the inner ring are limitedly supported by a positioning rod.

5. The centrally mounted intermediate locking phaser according to claim 2, characterized in that: The one-way valve assembly is composed of a one-way valve plate, a one-way valve spring and a one-way valve base; the one-way valve base has a stepped seat with a cylindrical structure, and the one-way valve spring is sleeved on the cylindrical structure of the one-way valve base.

6. The centrally mounted intermediate locking phaser according to claim 5, characterized in that: The one-way valve plate is close to the rear ends of the left stepped one-way valve hole and the right stepped one-way valve hole, the one-way valve base is close to the front ends of the left stepped one-way valve hole and the right stepped one-way valve hole, and the one-way valve spring is arranged between the one-way valve plate and the one-way valve base.

7. The centrally mounted intermediate locking phaser according to claim 2, characterized in that: The locking pin assembly consists of a locking pin, a locking spring and a locking spring seat.

8. The centrally mounted intermediate locking phaser according to claim 7, characterized in that: The locking pin is in the form of an elongated cylindrical structure, and a ring-shaped concave structure is provided in the middle of the elongated cylindrical structure; the locking spring is arranged between the groove at the front end of the locking pin and the locking spring seat.

9. The centrally mounted intermediate locking phase shifter according to any one of claims 1 to 8, characterized in that: The center of the sprocket body is provided with an axial circular hole, the outer ring of the sprocket body is provided with gear teeth, and the sprocket body is provided with a plurality of axial threaded holes.

10. The centrally mounted intermediate locking phaser according to claim 9, characterized in that: The three stator bosses are respectively provided with bolt through holes.

11. The centrally mounted intermediate locking phaser according to claim 10, characterized in that: The front cover is a disc-shaped structure, an axial special-shaped hole is provided at the inner center of the front cover and a plurality of axial conical threaded countersunk holes are provided on the front cover, screws pass through the axial conical threaded countersunk holes, bolt holes and threaded holes to screw and fix the front cover, stator and sprocket; an axially penetrating long groove or hole structure is provided at the edge of the front cover, a first positioning rod passes through the long groove or hole structure and is riveted and fixed to the stator, so as to limit the outer ring of the planar spiral structure reset spring.

12. The centrally mounted intermediate locking phaser according to claim 8, characterized in that: The second positioning rod and the third positioning rod pass through the central through hole of the front cover and are fixedly connected to the rotor by riveting, and are used to limit and support the inner ring of the planar helical structure return spring.

13. The centrally mounted intermediate locking phaser according to claim 1, characterized in that: The locking pin seat is a metal bushing, and the locking pin seat is fixedly connected to the sprocket by riveting; the locking pin seat is quenched and is a circular ring structure, and the interior of the circular ring structure has an elliptical center.

14. The centrally mounted intermediate locking phaser according to claim 1, characterized in that: The sprocket groove is a C-shaped groove.

15. The centrally mounted intermediate locking phaser according to claim 1, characterized in that: The sprocket and the stator are an integrated structure.

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