Valve timing adjustment device

Abstract

Valve timing adjustment device (100, 100a-100i) to be installed on an end section of an output shaft (320) located in an axial direction (AD) at one end of the output shaft, wherein the output shaft is configured to receive a drive force transmitted from a drive shaft (310) in an internal combustion machine (300), and the valve timing adjustment device is configured to use hydraulic pressure to adjust the timing of a valve driven by the output shaft such that it opens and closes, wherein the valve timing adjustment device comprises: a housing (120, 120a) configured to rotate synchronously with the drive shaft; a vane rotor (130) which is received in an interior of the housing and divides the interior of the housing into a plurality of hydraulic chambers (140), wherein the vane rotor is configured to be rotated synchronously with the output shaft; a support spring (50, 50e, 50f) configured to bias the vane rotor relative to the housing in a forward displacement direction or a retardation direction, the support spring comprising: a twisted segment (52); an inner end segment (54, 54e) which is joined to one end of the coiled segment and projects inwards in a radial direction (RD); and an outer end segment (56, 56e) which is joined to another end of the coiled segment and projects outwards in the radial direction; and a bushing component (10, 10a, 10c, 10e) that is fixed to the wing rotor, wherein: The bushing component is formed in a stepped cylindrical tubular shape and includes the following: a large-diameter section (15, 15a, 15c, 15e) formed in a cylindrical tubular shape and located on a radially inner side of the coiled segment, the large-diameter section comprising a straight section (25) located on a radially outer surface of the large-diameter section and extending in the axial direction; and a small-diameter section (13) formed in a cylindrical tubular shape and connected to the large-diameter section on an axial side of the large-diameter section on which the output shaft is placed, wherein the small-diameter section is placed on a radially inner side of the housing and has an outer diameter that is smaller than an outer diameter of the large-diameter section; the coiled segment includes a contact section (58, 58f) located on a radially inner surface of the coiled segment and configured to contact the straight section; and a point of an end of the straight section, which is located on one axial side on which the output shaft is placed, coincides in the axial direction with a point of an end of the contact section, which is located on one axial side, or which is one axial side of the point of the end of the contact section.

Description

Technical field

[0001] The present disclosure relates to a valve timing adjustment device. State of the art

[0002] A hydraulic valve timing adjustment device is known that can adjust or set the valve timing of intake or exhaust valves of an internal combustion engine. The valve timing adjustment device can include a support spring that biases a rotatable output body relative to a rotatable drive body in a forward or retardation direction. In a valve timing adjustment device described in patent reference 1, a bushing component, fixed to a vane rotor (which serves as a rotatable output body) and rotatably supporting a housing (which serves as a rotatable drive body), is inserted into a support spring. List of oppositions patent literature

[0003] Patent literature 1: JP 2017 - 101 608 A Summary of the invention

[0004] According to the inventor's concept of the present application, the bushing component described above would be designed in a stepped cylindrical tubular shape. This is for the following reason: The diameter of a section of the bushing component that contacts the housing in the radial direction can be reduced to increase the sealing surface between the rotor and the housing, thereby limiting hydraulic oil leakage through a gap between the rotor and the housing. Conversely, the diameter of the other section of the bushing component, which contacts the support spring in the radial direction, can be increased to allow the use of a support spring with a larger diameter, thus increasing the output torque of the support spring.

[0005] In the case where the bushing component is formed in a stepped cylindrical tubular shape, a gap must be formed between the bushing component and the housing at the stepped section of the bushing component to ensure sliding capability between the bushing component and an axial end surface of the housing. The inventor of the present application determined that the contact area between the support spring and the bushing component on a portion of a radially inner surface of the support spring, which is supported by the bushing component, can potentially be reduced if the support spring is positioned radially on the outer side of this gap.Reducing the contact area increases the contact pressure between the support spring and the bushing component, potentially leading to increased wear between the two. Therefore, it is desirable to have a technique that can limit the reduction in the contact area between the support spring and the bushing component.

[0006] The present revelation can be implemented as follows.

[0007] According to one aspect or embodiment of the present disclosure, a valve timing adjustment device is provided which is to be installed on an end section of an output shaft located axially at one end of the output shaft, wherein the output shaft is configured to receive a drive force transmitted from a drive shaft in an internal combustion machine, and the valve timing adjustment device is configured to use hydraulic pressure to adjust the timing of a valve driven by the output shaft such that it opens and closes, wherein the valve timing adjustment device comprises the following: a housing configured to rotate synchronously with the drive shaft, a vane rotor which is accommodated in an interior of the housing and divides the interior of the housing into a plurality of hydraulic chambers, the vane rotor being configured to rotate synchronously with the output shaft; a support spring configured to bias the wing rotor relative to the housing in a forward displacement direction or a retardation direction, wherein the support spring comprises the following: a winding segment; an inner end segment which is joined to one end of the coiled segment and projects inwards in a radial direction; and an outer end segment which is joined to another end of the coiled segment and projects outwards in the radial direction; and a bushing component that is fixed to the wing rotor, wherein: The bushing component is formed in a stepped cylindrical tubular shape and includes the following: a large-diameter section formed in a cylindrical tubular shape and located on a radially inner side of the coiled segment, wherein the large-diameter section includes a straight section located on a radially outer surface of the large-diameter section and extending in the axial direction; and a small-diameter section formed in a cylindrical tubular shape and connected to the large-diameter section on an axial side of the large-diameter section on which the output shaft is placed, wherein the small-diameter section is placed on a radially inner side of the housing and has an outer diameter that is smaller than the outer diameter of the large-diameter section; the coiled segment includes a contact section located on a radially inner surface of the coiled segment and configured to contact the straight section; and a point of an end of the straight section, which is located on one axial side on which the output shaft is placed, coincides in the axial direction with a point of an end of the contact section, which is located on one axial side, or which is one axial side of the point of the end of the contact section.

[0008] In the valve timing adjustment device, the point at the end of the straight section located on the axial side where the output shaft is positioned coincides axially with, or is the axial side of, the point at the end of the contact section located on the axial side. Therefore, it is possible to restrict the end of the contact section of the coiled segment on the output shaft side from coming into contact with the straight section, thereby limiting the contact area between the support spring and the bushing component.

[0009] The present disclosure can be implemented in various forms. For example, the present disclosure can be implemented as a machine with internal combustion which includes the valve timing adjustment device, as well as a manufacturing method for the valve timing adjustment device. Brief description of the drawings

[0010] The present disclosure, together with its additional functions, features and advantages, will best be understood from the following description with reference to the accompanying drawings. Fig. 1 a cross-sectional view showing a schematic configuration of a valve timing adjustment device of a first embodiment; Fig. 2 a cross-sectional view, wherein the cross-section is shown along a line II-II in Fig. 1 has been undertaken; Fig. 3 a front view of the valve timing adjustment device, viewed from a side opposite a camshaft; Fig. 4 an enlarged cross-sectional view showing a section of a cross-section extending along a line 4-4 in Fig. 3 has been carried out; Fig. 5 an enlarged cross-sectional view showing a schematic configuration of a valve timing adjustment device of a second embodiment; Fig. 6 an enlarged cross-sectional view showing a schematic configuration of a valve timing adjustment device of a third embodiment; Fig. 7 an enlarged cross-sectional view showing a schematic configuration of a valve timing adjustment device of a fourth embodiment; Fig. 8 an enlarged cross-sectional view showing a schematic configuration of a valve timing adjustment device of a fifth embodiment; Fig. 9 an enlarged cross-sectional view showing a schematic configuration of a valve timing adjustment device of a sixth embodiment; Fig. 10 an enlarged cross-sectional view showing a schematic configuration of a valve timing adjustment device of a seventh embodiment; Fig. 11 an enlarged cross-sectional view showing a schematic configuration of a valve timing adjustment device of another embodiment 1; Fig. 12 an enlarged cross-sectional view showing a schematic configuration of a valve timing adjustment device of the other embodiment 1; Fig. 13 an enlarged cross-sectional view showing a schematic configuration of a valve timing adjustment device of another embodiment 5. Description of the embodiments A. First embodiment

[0011] A valve timing adjustment device 100 of Fig. The device 100 is configured to adjust the valve timing of valves driven by a camshaft 320, which receives a drive force transmitted from a crankshaft 310 in an internal combustion engine of a (not shown) vehicle 300, such that the valves open and close. The valve timing adjustment device 100 is installed in a drive force transmission path extending from the crankshaft 310 to the camshaft 320. More precisely, the valve timing adjustment device 100 is fixed in one direction (hereinafter referred to as an axial direction AD) along an axis of rotation AX of the camshaft 320 at an end section of the camshaft 320. The axis of rotation AX of the valve timing adjustment device 100 coincides with the axis of rotation AX of the camshaft 320.In the case of (not shown in detail) intake valves and exhaust valves, which serve as valves, the valve timing adjustment device 100 of the present embodiment adjusts the valve timing of the exhaust valves.

[0012] An axial hole 322, a delay supply hole 324, and an advance supply hole 326 are formed in the end section of the camshaft 320. The axial hole 322 extends in the axial direction AD. A central bolt 190 is inserted into the axial hole 322 through a wall component 195, which is formed in a cylindrical tubular shape, as described later. The delay supply hole 324 and the advance supply hole 326 each extend in a radial direction RD. The radial direction RD and the axial direction AD are perpendicular to each other. Hydraulic oil is routed through both the delay supply hole 324 and the advance supply hole 326. The hydraulic oil is supplied to and discharged from the delay supply port 324 and the advance supply port 326 via a hydraulic oil control valve 350. The hydraulic oil control valve 350 is a piston valve actuated by a solenoid.The hydraulic oil control valve 350 controls the hydraulic pressure of the hydraulic oil to be supplied to the delay supply port 324 and the advance supply port 326. The operation of the hydraulic oil control valve 350 is controlled by instructions from an ECU (not shown) that controls the overall operation of the internal combustion machine 300. The hydraulic oil is supplied to the hydraulic oil control valve 350 from an oil pump 351. The oil pump 351 pumps the hydraulic oil up to an oil sump 352. The hydraulic oil discharged through the hydraulic oil control valve 350 is drained into the oil sump 352.

[0013] The valve timing adjustment device 100 includes a sprocket 110, a rear cover 115, a housing 120, a vane rotor 130, a bushing component 10, a retaining pin 40, a support spring 50, a front cover 180, a cap 185, the center bolt 190 and the wall component 195.

[0014] The sprocket 110 cooperates with the rear cover 115 and the housing 120, or rather interacts with them, to function as a rotatable drive element that rotates synchronously with the crankshaft 310. A timing chain 360, formed in a loop shape, is wound around the sprocket 110 and a sprocket section 311 of the crankshaft 310. The sprocket 110 is fixed to the rear cover 115 and the housing 120 by a plurality of bolts 112 on its rear side.

[0015] The rear cover 115 is installed on an end surface of the housing 120, which is located on the side (hereinafter referred to simply as the "camshaft 320 side") on which the camshaft 320 is positioned in the axial direction AD. The rear cover 115 slidably contacts an end surface of the vane rotor 130, which is located on the camshaft 320 side.

[0016] The housing 120 is formed in a tubular shape with a base and accommodates the bladed rotor 130. The housing 120 comprises a cylindrical tubular section 121, a base section 125, and a position-limiting section 80.

[0017] The cylindrical tubular section 121 extends in the axial direction AD. As in Fig. As shown in Figure 2, the cylindrical tubular section 121 includes a plurality of partitions 123 that project inwards in the radial direction RD and are arranged one after the other in the circumferential direction. A corresponding assembly of a plurality of vanes 131 of the vane rotor 130, which will be described later, is inserted between each pair of circumferentially adjacent partitions 123.

[0018] As in Fig. As shown in Figure 1, the base section 125 extends in the radial direction RD. An opening 126 is formed at a midpoint of the base section 125. A small-diameter section 13 of the bushing component 10, which will be described later, is inserted into the opening 126. An inner surface 127 of the base section 125, located on the side of the camshaft 320, slidably contacts an end surface of the vane rotor 130, which is located on an opposite side (hereinafter simply referred to as the "side of the front cover 180"), which is arranged in the axial direction AD opposite the side of the camshaft 320. A fitting recess 128 is formed on the inner surface 127 at a location corresponding to a locking pin 150, which will be described later.An outer surface 129, which is an end surface of the bottom section 125, located on the side of the front cover 180 and positioned in the radial direction RD on the inner side of the position-limiting section 80, is slidable relative to a sliding surface 17 of the bushing component 10, which will be described later.

[0019] The position-limiting section 80 is formed on an end surface of the housing 120, located on the side of the front cover 180 and positioned in the radial direction RD on an outer side of the outer surface 129. In the present embodiment, the outer surface 129 is recessed from the position-limiting section 80 towards the side of the camshaft 320, so that the position-limiting section 80 projects in an annular shape around its entire circumference towards the side of the front cover 180. The position-limiting section 80 contacts a section of an end surface of the support spring 50, which is located on the side of the camshaft 320. In this way, the position-limiting section 80 restricts the position of the support spring 50 relative to the bushing component 10 in the axial direction AD.

[0020] An insertion hole 124, extending in the axial direction AD, is formed on the end surface of the housing 120, which is located on the side of the front cover 180. In the present embodiment, the insertion hole 124 is formed on the position-limiting section 80. The retaining pin 40 is inserted into the insertion hole 124 and secured therein.

[0021] The vane rotor 130 is housed in the casing 120. In a state where the vane rotor 130 is clamped between a bushing bottom section 11 of the bushing component 10, which will be described later, and an end surface of the camshaft 320, the central bolt 190 is attached to the end section of the camshaft 320. Therefore, the vane rotor 130 rotates synchronously with the camshaft 320. The vane rotor 130 is rotated relative to the casing 120 in a deceleration or an advance direction according to the hydraulic pressure of the hydraulic oil supplied by the hydraulic oil control valve 350. In this way, the relative rotational phase of the camshaft 320 relative to the crankshaft 310 is changed.

[0022] As in Fig. As shown in Figure 2, the rotor 130 comprises the blades 131 and a hub 135. Extending radially outward from the hub 135, which is located at the center point of the rotor 130, the blades 131 are arranged one after the other circumferentially. Each blade 131 is held circumferentially between two corresponding adjacent partitions 123 and divides a corresponding space into a deceleration chamber 141 and a forward displacement chamber 142, each of which serves as a hydraulic chamber 140. The deceleration chamber 141 is located circumferentially on one side of the blade 131. The forward displacement chamber 142 is located circumferentially on the other side of the blade 131. A receiving hole 132 extends axially along one of the blades 131.The receiving hole 132 is connected to the adjacent delay chamber 141 via a pin-control oil passage 133 on the side of the delay chamber, which is formed on the vane 131, and to the adjacent advance chamber 142 via a pin-control oil passage 134 on the side of the advance chamber, which is formed in the vane 131. The locking pin 150, which is configured to move back and forth in the axial direction AD, is located in the receiving hole 132. The locking pin 150 restricts rotation of the vane rotor 130 relative to the housing 120 and, in a condition where the hydraulic pressure is insufficient, restricts collision between the housing 120 and the vane rotor 130 in the circumferential direction. The locking pin 150 is pre-tensioned by a pre-tension spring 151 in the axial direction AD towards the fitting recess 128, which is formed on the inner surface 127 of the housing 120.

[0023] The hub 135 has an outer shape that is cylindrical and tubular. A through-hole 136 extends axially AD through the center of the hub 135. The inner diameter of the through-hole 136 decreases in a stepped fashion in the axial direction AD from the side of the camshaft 320 to the side of the front cover 180. The central bolt 190 is inserted into the through-hole 136 through the wall component 195, which is also cylindrical and tubular. A fitting section 31 is formed at the center point of the end surface 139 of the hub 135, which is located on the side of the front cover 180. The bushing component 10 is fitted into the fitting section 31. A plurality of retarding oil passages 137 and a plurality of forward displacement oil passages 138 extend in the radial direction RD through the hub 135.Each of the delay oil passages 137 and a corresponding advance oil passage 138 are arranged side by side in the axial direction AD. Each delay oil passage 137 connects a delay connecting passage 371, which will be described later, to the corresponding delay chamber 141. Each advance oil passage 138 connects a advance connecting passage 372, which will be described later, to the corresponding advance chamber 142.

[0024] In Fig. Figure 3 shows the valve timing adjustment device 100 without the front cover 180 and the cap 185 for better understanding. The bushing component 10, which is located in the Fig. 1 and Fig. As shown in Figure 3, the bushing component 10 is fixed to the rotor 130 in such a way that it rotates integrally with the rotor 130. In the present embodiment, the bushing component 10 has the function of rotatably mounting the housing 120.

[0025] The bushing component 10 has an external shape that is a stepped cylindrical tubular form with a base. The reason why the bushing component 10 has this configuration will be discussed later. The bushing component 10 includes the bushing base section 11, the small-diameter section 13, a large-diameter section 15, and the sliding surface 17.

[0026] The bushing bottom section 11 extends radially RD and forms an end part of the bushing component 10, which is located on the side of the camshaft 320. A bushing through-hole 21 extends axially AD through a center point of the bushing bottom section 11. The center bolt 190 is inserted through the bushing through-hole 21. A pin through-hole 22 also extends axially through the bushing bottom section 11. A dowel pin 30 is inserted through the pin through-hole 22. In this configuration, the relative position between the bushing component 10 and the vane rotor 130 is limited in the circumferential direction.

[0027] The small-diameter section 13 is joined to an outer periphery of the bushing bottom section 11 and has an outer shape that is cylindrical and tubular, extending in the axial direction AD. The small-diameter section 13 is inserted into the opening 126 of the bottom section 125 of the housing 120. The small-diameter section 13 is positioned radially RD on the inner side of the opening 126 of the housing 120, so that the small-diameter section 13 rotatably supports the housing 120.

[0028] The large-diameter section 15 forms an end part of the bushing component 10, which is located on the side of the front cover 180 and has an outer shape that is cylindrical and tubular, extending in the axial direction AD. The outer diameter of the large-diameter section 15 is larger than the outer diameter of the small-diameter section 13. The large-diameter section 15 is inserted and positioned in the radial direction RD on the inner side of a helical segment 52 of the support spring 50. A straight section 25 extends along an outer surface of the large-diameter section 15, located on the outer side in the radial direction RD, in the axial direction AD. As shown in Fig. As shown in Figure 1, a retaining section 26, which is recessed inwards in the radial direction RD, is formed at a circumferential location on the radially outer surface of the large-diameter section 15, which is located on the outer side in the radial direction RD. The retaining section 26 holds an inner end segment 54 of the support spring 50, which will be described later. Furthermore, the radially outer surface of the large-diameter section 15, which is located on the outer side in the radial direction RD, contacts a contact section 58 of the support spring 50, which will be described later, at a circumferential location that differs from the location of the retaining section 26.

[0029] Fig. Figure 4 shows, on an enlarged scale, a section of a cross-section which includes the contact section 58 and extends along the radial direction RD. As in Fig. As shown in Figure 4, the sliding surface 17 extends in the radial direction RD and connects the small-diameter section 13 and the large-diameter section 15. Therefore, the small-diameter section 13 is located in the axial direction AD on the side of the camshaft 320 of the large-diameter section 15 and is connected to the large-diameter section 15 by the sliding surface 17. The sliding surface 17 is slidable or displaceable relative to the outer surface 129 of the bottom section 125 of the housing 120. Therefore, a gap C is formed in the axial direction AD between the sliding surface 17 and the bottom section 125 to ensure sliding capability between the sliding surface 17 and the bottom section 125.Furthermore, a corner R1, which is an outer periphery of the sliding surface 17 and is formed by a large-diameter end portion of the section 15 located on the side of the camshaft 320, has a predetermined radius of curvature in its cross-section along the radial direction RD. Therefore, corner R1 does not contact the contact section 58 of the support spring 50. Of the two opposing end portions of the straight section 25, which are arranged opposite each other in the axial direction AD, corner R1 is joined to the end portion of the straight section 25 located on the side of the camshaft 320.

[0030] The retaining pin 40, which is in the Fig. 1 and Fig. The component shown in Figure 3 is inserted into the insertion hole 124 of the housing 120 and fixed therein. The retaining pin 40 holds an outer end segment 56 of the support spring 50, which will be described later.

[0031] The support spring 50 is located in the radial direction RD on the outer side of the large-diameter section 15 of the bushing component 10. The support spring 50 is a torsion coil spring. In the present embodiment, the support spring 50 biases the rotor 130 relative to the housing 120 in the forward displacement direction. The reason for this will be described below.

[0032] The camshaft 320, which is in Fig. As shown in Figure 1, the rotor is rotated to open each exhaust valve against the preload force of a valve spring (not shown). Therefore, the vane rotor 130, which rotates integrally with the camshaft 320, receives a force exerted by a positive torque of the camshaft 320 and preloads the vane rotor 130 in a reverse direction towards the retardation side. Generally, it is necessary that the valve timing adjustment device 100, which adjusts the valve timing of the exhaust valves, sets the relative rotational phase of the camshaft 320 to a phase on the advance side at the time the engine 300 is started with internal combustion, relative to the crankshaft 310. For this reason, the vane rotor 130 is preloaded in the advance direction relative to the housing 120 by the support spring 50.

[0033] As in Fig. As shown in Figure 3, the support spring 50 is eccentric to the bushing component 10. The support spring 50 includes the coiled segment 52, the inner end segment 54, and the outer end segment 56.

[0034] The winding segment 52, which is in the Fig. 1 and Fig. As shown in Figure 3, it is formed by winding a wire spirally and has an outer shape that is generally cylindrical and tubular. The large-diameter section 15 is inserted and positioned in the radial direction RD on the inner side of the wound segment 52. As shown in Fig. As shown in Figure 3, the coiled segment 52 includes the contact section 58, which is formed on the radially inner surface of the coiled segment 52, located on the inner side in the radial direction RD, such that the contact section 58 is located on a portion of the circumferential dimension of the coiled segment 52 and is configured to contact the straight section 25. The contact section 58 will be described in detail later. The remaining radially inner surface of the coiled segment 52, which is different from the contact section 58 in the circumferential direction, does not contact the straight section 25 of the bushing component 10.

[0035] The inner end segment 54 is connected to one end of the coiled segment 52 and is formed by bending the wire such that the inner end segment 54 projects inwards in the radial direction RD. The inner end segment 54 is positioned on and held by the retaining section 26 of the bushing component 10.

[0036] The outer end segment 56 is connected to the other end of the coiled segment 52 and is formed by bending the wire such that the outer end segment 56 projects outwards in the radial direction RD. The outer end segment 56 is positioned so that it is hooked onto and held by the retaining pin 40.

[0037] In the configuration described above, the support spring 50 is supported at three circumferential points, namely the inner end segment 54, the outer end segment 56, and the contact section 58, by the bushing component 10 and the retaining pin 40. In the present embodiment, the outer end segment 56 is located in the axial direction AD on the side of the camshaft 320 of the inner end segment 54. Furthermore, in the present embodiment, the support spring 50 is a rectangular wire spring, which is made from wire having a rectangular cross-section. As in Fig. As shown in Figure 4, one corner R2 of a cross-section of this wire is rounded and has a predetermined radius of curvature. In other words, the term "rectangular cross-section" refers not only to a strictly rectangular cross-section with sharp corners, but also to a macroscopic rectangular cross-section with rounded corners. In the present embodiment, the support spring 50 can also be made from a wire having any polygonal cross-section, such as a hexagonal cross-section, although the support spring 50 is made from the wire having the rectangular cross-section.

[0038] As in Fig. As shown in Figure 1, the front cover 180 is located on the opposite side of the valve timing adjustment device 100, which is arranged in the axial direction AD opposite the side of the camshaft 320. The front cover 180 is fixed to the housing 120 on its front side by a plurality of bolts 188. An opening 184 is generally formed at the center point of the front cover 180. The cap 185 is inserted into the opening 184 to close it.

[0039] The central bolt 190 is positioned along the axis of rotation AX of the valve timing device 100 and secures the valve timing device 100 to the end section of the camshaft 320. The central bolt 190 includes a shaft 191, located in the axial direction AD on the side of the camshaft 320, and a head 192, located in the axial direction AD on the side of the front cover 180. The shaft 191 is inserted through the bushing through-hole 21 of the bushing bottom section 11 of the bushing component 10 and the through-hole 136 of the hub 135 of the vane rotor 130 and is secured at the axial hole 322 such that the wall component 195 is inserted into the radially outer side of the shaft 191. Therefore, the bottom section 125 of the bushing component 10 and the wing rotor 130 are clamped between the head 192 of the central bolt 190 and the end surface of the camshaft 320.In this configuration, the wing rotor 130 and the bushing component 10 are rotated integrally with the camshaft 320.

[0040] The wall component 195 has a cylindrical, tubular shape and surrounds the shaft 191 of the central bolt 190. The wall component 195 divides the space defined between the inner peripheral surface of the axial hole 322 of the camshaft 320 and the outer peripheral surface of the shaft 191 of the central bolt 190 in the radial direction RD into the retardation connection passage 371 and the advance connection passage 372.

[0041] The hydraulic oil supplied to the deceleration supply port 324 by the hydraulic oil control valve 350 is fed to the deceleration chambers 141 through the deceleration connecting passage 371 and the deceleration oil passages 137. As a result, the vane rotor 130 is subjected to a relative rotation in the deceleration direction with respect to the housing 120, so that the rotational phase of the camshaft 320 relative to the crankshaft 310 shifts towards the deceleration side. Furthermore, the hydraulic oil supplied to the advance supply port 326 by the hydraulic oil control valve 350 is fed to the advance chambers 142 through the advance connecting passage 372 and the advance oil passages 138. As a result, the rotor 130 is subjected to a relative rotation relative to the housing 120 in the forward displacement direction, so that the rotational phase of the camshaft 320 relative to the crankshaft 310 shifts towards the forward displacement side.Furthermore, the rotation of the vane rotor 130 relative to the housing 120 is limited when hydraulic oil is supplied to both the retardation chambers 141 and the advance chambers 142, so that the rotational phase of the camshaft 320 relative to the crankshaft 310 is maintained.

[0042] The hydraulic oil supplied to the deceleration chambers 141 or the advance chambers 142 flows through the pin control oil passage 133 on the deceleration chamber side or the pin control oil passage 134 on the advance chamber side into the receiving hole 132. Therefore, when sufficient hydraulic pressure is applied to the deceleration chambers 141 or the advance chambers 142, the locking pin 150 is removed from the fitting recess 128 by the hydraulic oil supplied to the receiving hole 132, against the preload force of the preload spring 151. This allows the rotation of the vane rotor 130 relative to the housing 120.

[0043] One reason why the bushing component 10 of the present embodiment is formed in a stepped cylindrical tubular shape will be explained below. As described above, the hydraulic oil flows into the hydraulic chambers 140, which are formed by the impeller rotor 130 and the housing 120. The hydraulic oil in the hydraulic chambers 140 may leak through a gap between the end surface 139 of the hub 135 and the inner surface 127 of the housing 120. For this reason, it is desirable to ensure a large sealing area between the end surface of the hub 135 and the inner surface 127 of the housing 120. Therefore, it is conceivable to ensure the large dimension of the end surface 139 of the hub 135, which is measured in the radial direction RD, by reducing the dimension of the fitting section 31 of the hub 135, which is measured in the radial direction RD at the end surface 139 of the hub 135.For this reason, in the present embodiment, the outer diameter of the small-diameter section 13 of the bushing component 10, which has the function of rotatably mounting the housing 120, is reduced in order to enable the small-diameter section 13 to be installed in the fitting section 31 of the hub 135.

[0044] Furthermore, it is desirable to design the bushing component 10 according to the inner diameter of the support spring 50, which can ensure the required torque, since the bushing component 10 supports the support spring 50, which is eccentric to the axis of rotation AX, on a portion of a circumferential dimension of the bushing component 10. Therefore, in the bushing component 10, the outer diameter of the large-diameter section 15, which contacts the support spring 50 in the radial direction RD, is increased according to the present embodiment in order to use the support spring 50 with the large diameter that can ensure the high output torque of the support spring 50.

[0045] Since the bushing component 10 is formed in a stepped cylindrical tubular shape, a gap C is required in the axial direction AD between the sliding surface 17, which connects the small-diameter section 13 and the large-diameter section 15, and the outer surface 129 of the housing 120 to ensure sliding capability between the sliding surface 17 and the outer surface 129 of the housing 120. The contact area between the support spring 50 and the bushing component 10 at the contact section 58 of the radially inner surface of the support spring 50, which is supported by the bushing component 10, may be reduced if the support spring 50 is positioned on the outer side of the gap C in the radial direction RD.However, in the valve timing adjustment device 100 of the present embodiment, it is possible to limit a reduction with regard to the contact area between the support spring 50 and the bushing component 10 by providing the following configuration.

[0046] As described above, the corner R2 of the cross-section of the wire of the support spring 50 is rounded and has a predetermined radius of curvature. Therefore, at the circumferential point where the contact section 58 is located, the corner R2 of the support spring 50 does not contact the straight section 25 in the radial direction RD, as shown in Fig. Figure 4 shows that corner R2 does not form the contact section 58. More precisely, the contact section 58 is formed as part of the radially inner surface of the helical segment 52, which contacts the straight section 25 of the bushing component 10.

[0047] Here, a distance L1, measured in the axial direction AD from the end surface of the position-limiting section 80, located on the side of the front cover 180, to the sliding surface 17 of the bushing component 10, is set such that it is greater than the difference between the outer circumferential length of corner R1 of the cross-section of the bushing component 10 and the outer circumferential length of corner R2 of the cross-section of the wire of the support spring 50 in the cross-section along the radial direction RD. In this configuration, the end on the side of the camshaft 320 of the straight section 25 is located in the axial direction AD on the side of the camshaft 320 of the contact section 58.It is understood that the distance L1 can be set such that it is greater than the difference between the axial length of corner R1 of the bushing component 10, measured in the axial direction AD, and the axial length of corner R2 of the support spring 50, also measured in the axial direction AD. In the present embodiment, the sliding surface 17 is located at the circumferential point where the contact section 58 is formed, on the side of the camshaft 320 and on the side of the camshaft 320 of the support spring 50.

[0048] Furthermore, in Fig. Figure 4 shows for better understanding that the position-limiting section 80 is in contact with the end surface on the side of the camshaft 320 of the helical segment 52 of the support spring 50 at a circumferential point that corresponds to the circumferential point of the contact section 58. It is understood that the position-limiting section 80 can contact at least a circumferential part of the end surface on the side of the camshaft 320 of the support spring 50, instead of the circumferential point that corresponds to the circumferential point of the contact section 58, for example, at a circumferential point that corresponds to a circumferential point of the inner end segment 54, which is in Fig. 3 is shown, corresponds to.

[0049] In the present embodiment, the crankshaft 310 corresponds to the secondary aspect of the drive shaft of the present disclosure, and the camshaft 320 corresponds to the secondary aspect of the output shaft of the present disclosure.

[0050] In the valve timing adjustment device 100 of the first embodiment described above, the coiled segment 52 includes the contact section 58, which is formed on the radially inner surface of the coiled segment 52 and is configured to contact the straight section 25. The end of the straight section 25 on the camshaft 320 side is located in the axial direction AD on the camshaft 320 side of the contact section 58. Therefore, it is possible to restrict the end of the contact section 58 on the camshaft 320 side of the coiled segment 52 from coming into contact with the straight section 25 of the large-diameter section 15, and thus it is possible to limit the reduction of the contact area between the support spring 50 and the bushing component 10.Therefore, it is possible to limit an increase in contact pressure generated between the support spring 50 and the bushing component 10, and thereby it is possible to limit an increase in wear between the support spring 50 and the bushing component 10.

[0051] Furthermore, due to the provision of the bushing component 10, which is formed in a stepped cylindrical tubular shape, the diameter of the small-diameter section 13, which contacts the housing 120 in the radial direction RD, can be reduced to ensure a large sealing area between the end surface 139 of the hub 135 and the inner surface 127 of the housing 120. Therefore, it is possible to limit the leakage of hydraulic oil from the hydraulic chambers 140 through the gap between the end surface 139 of the hub 135 and the inner surface 127 of the housing 120. Additionally, the large-diameter support spring 50 can be used, since the diameter of the large-diameter section 15, which contacts the support spring 50 in the radial direction RD, can be increased. Thus, the output torque of the support spring 50 can be increased.

[0052] Furthermore, the position-limiting section 80 formed on the housing 120 restricts the position of the support spring 50 relative to the bushing component 10 in the axial direction AD. This can limit the number of parts required to limit such a position and thus limit or prevent the manufacturing process from becoming complicated. Additionally, the housing 120 can be formed by a cutting process, which limits the manufacturing costs of the housing 120, since the position-limiting section 80, which projects towards the side of the front cover 180, is implemented by recessing the outer surface 129 towards the side of the camshaft 320.

[0053] Furthermore, the stiffness of the support spring 50 can be increased, since the support spring 50 is a rectangular wire spring, and the length of the support spring 50 in the axial direction AD can be reduced. This makes it possible to improve the ease of assembly of the support spring 50 and to limit any increase in the dimensions of the valve timing adjustment device 100, measured in the axial direction AD.

[0054] Furthermore, it is possible to limit the excessive projection of the retaining pin 40 towards the side of the front cover 180, thereby limiting the deterioration in terms of the ease of assembly of the retaining pin 40, since the outer end segment 56 of the support spring 50 is located in the axial direction AD on the side of the camshaft 320 of the inner end segment 54 of the support spring 50. Therefore, it is possible to limit any increase in the dimension of the valve timing adjustment device 100, measured in the axial direction AD.

[0055] Furthermore, the sliding surface 17 of the bushing component 10 is located at the circumferential point where the contact section 58 is formed, in the axial direction AD on the side of the camshaft 320 and on the side of the camshaft 320 of the support spring 50, so that the support spring 50 is not located on the outer side of the gap C in the radial direction RD. Therefore, it is possible to limit the reduction of the contact area between the support spring 50 and the bushing component 10 at the contact section 58, which is formed on the radially inner surface of the support spring 50 and is supported by the bushing component 10.As a result, it is possible to limit the reduction in the contact area between the support spring 50 and the bushing component 10 compared to the structure in which the support spring 50 is positioned on the outer side of the gap C in the radial direction RD. Therefore, it is possible to limit the increase in contact pressure generated between the support spring 50 and the bushing component 10, and consequently, it is possible to limit the increase in wear between the support spring 50 and the bushing component 10. B. Second embodiment

[0056] The valve timing adjustment device 100a of a second embodiment, which is in Fig. Figure 5 shows a valve timing adjustment device 100 in the second embodiment that differs from the first embodiment in terms of the configuration of a position-limiting section 80a. More precisely, the second embodiment's valve timing adjustment device 100a differs from the first embodiment's in that it includes a housing 120a and a bushing component 10a instead of the housing 120 and the bushing component 10. Other parts are the same as in the first embodiment, so identical parts are indicated by the same reference numerals and their detailed descriptions are omitted. Fig. Figure 5 shows, on an enlarged scale, a section of a cross-section which includes the inner end segment 54 and resembles the cross-section shown in Fig. 1 is shown.

[0057] The position-limiting section 80 is removed from the housing 120a. Therefore, the end surface of the housing 120a, located on the side of the front cover 180, is flat. The bushing component 10a includes a large-diameter section 15a instead of the large-diameter section 15. The radially outer surface of the large-diameter section 15a, located on the outer side in the radial direction RD, has a retaining section 26a that is recessed inwards in the radial direction RD and is located at a circumferential point on the radially outer surface of the large-diameter section 15a. The retaining section 26a of the second embodiment is formed at a point that is slightly displaced in the axial direction AD from the position of the retaining section 26 of the first embodiment towards the side of the front cover 180.In this configuration, the retaining section 26a functions as the position-limiting section 80a, and the retaining section 26a holds the inner end segment 54 of the support spring 50 and contacts the end surface on the camshaft 320 side of the inner end segment 54. More precisely, the retaining section 26a also has the function of the position-limiting section 80a. Even in the present embodiment, the end is located on the camshaft 320 side of the straight section (which is shown in ). Fig. 5 not shown in detail) in the axial direction AD on the side of camshaft 320 of the end on the side of camshaft 320 of the contact section (which is in Fig. 5 is not shown in detail).

[0058] The valve timing adjustment device 100a of the second embodiment described above can achieve advantages similar to those of the valve timing adjustment device 100 of the first embodiment. In addition, it is possible to limit the increase in the number of parts, thereby limiting or preventing the complexity of the manufacturing process, since the position limitation section 80a of the holding section 26a of the bushing component 10a also performs the function of the position limitation section 80a. C. Third embodiment

[0059] The valve timing adjustment device 100b of a third embodiment, which is in Fig. The valve timing adjustment device 100 of the third embodiment, as shown in Figure 6, differs from the valve timing adjustment device 100 of the first embodiment with respect to the configuration of a position-limiting section 80b. More precisely, the valve timing adjustment device 100b of the third embodiment differs from the valve timing adjustment device 100 of the first embodiment in that, instead of the housing 120, the valve timing adjustment device 100b includes the housing 120a, which is similar to the housing 120a of the second embodiment, and furthermore includes an intermediate component 80b, which has the function of the position-limiting section 80b. Other parts are the same as in the first embodiment, so identical parts are indicated by the same reference numerals and their detailed descriptions are omitted. Fig. Figure 6 shows, on an enlarged scale, a section of a cross-section which includes the contact section 58, as in Fig. 4.

[0060] The position-limiting section 80 is removed from the housing 120a. Therefore, the end surface of the housing 120a, located on the side of the front cover 180, is flat. In the present embodiment, the intermediate component 80b is a washer having an outer ring shape. The inner diameter of the intermediate component 80b is generally the same as the inner diameter of the coiled segment 52 of the support spring 50. One surface of the intermediate component 80b, located on one side in the axial direction AD, contacts the housing 120, and the other surface of the intermediate component 80b, located on the opposite side in the axial direction AD, contacts the end surface on the camshaft 320 side of the support spring 50 in the axial direction AD. Fig. Figure 6 shows for better understanding that the intermediate component 80b contacts the end surface on the side of the camshaft 320 of the support spring 50 at a circumferential point corresponding to the circumferential point of the contact section 58. However, the intermediate component 80b can contact at least one circumferential part of the end surface on the side of the camshaft 320 of the support spring 50 instead of the circumferential point corresponding to the circumferential point of the contact section 58, for example, at a circumferential point corresponding to the circumferential point of the (in Fig. 6 (not shown in detail) inner end segment of the support spring 50. Furthermore, the intermediate component 80b should not be limited to the washer, but can be a component that can be inserted between the housing 120a and the support spring 50, such as a ring formed in a cylindrical tubular shape.

[0061] The valve timing adjustment device 100b of the third embodiment described above can achieve advantages similar to those of the valve timing adjustment device 100 of the first embodiment. In addition, the position of the support spring 50 relative to the bushing component 10 in the axial direction AD is limited by the intermediate component 80b, which also has the function of the position limitation section 80b, thus simplifying the configuration for limiting the position of the support spring 50 relative to the bushing component 10 in the axial direction AD. D. Fourth embodiment

[0062] The valve timing adjustment device 100c of a fourth embodiment, which is in Fig. Figure 7 differs from the valve timing adjustment device 100a of the second embodiment with respect to the configuration of a position-limiting section 80c. More precisely, the valve timing adjustment device 100c of the third embodiment differs from the valve timing adjustment device 100a of the second embodiment in that the valve timing adjustment device 100c includes a bushing component 10c instead of the bushing component 10a. Other parts are the same as in the second embodiment, so identical parts are indicated by the same reference numerals and their detailed descriptions are omitted. Fig. Figure 7 shows, on an enlarged scale, a section of a cross-section which includes the contact section 58, as in Fig. 4.

[0063] The bushing component 10c includes a large-diameter section 15c instead of the large-diameter section 15a. A position-limiting section 80c, which projects outwards in the radial direction RD, is formed on the end portion of the large-diameter section 15c, which is located on the camshaft 320 side in the axial direction AD. The position-limiting section 80c contacts a portion of an end surface of the support spring 50, which is located on the camshaft 320 side in the axial direction AD. In the present embodiment, the position-limiting section 80c is configured such that it projects outwards in the radial direction RD and extends completely around the large-diameter section 15c in the circumferential direction.Alternatively, the position restriction section 80c can be formed along at least part of the circumference of section 15c with a large diameter. Furthermore, in . Fig. Figure 7 shows for better understanding that the position-limiting section 80c contacts the end surface on the side of the camshaft 320 of the support spring 50 at a circumferential point that corresponds to the circumferential point of the contact section 58. Here, the position-limiting section 80c can contact at least a circumferential part of the end surface on the side of the camshaft 320 of the support spring 50 instead of the circumferential point that corresponds to the circumferential point of the contact section 58, for example, at a circumferential point that corresponds to the circumferential point of the (in Fig. 7 (not shown in detail) inner end segment of the support spring 50 corresponds to.

[0064] The valve timing adjustment device 100c of the fourth embodiment described above can achieve the advantages that are similar to those of the valve timing adjustment device 100a of the second embodiment. E. Fifth embodiment

[0065] The valve timing adjustment device 100d of a fifth embodiment, which is in Fig. The fifth embodiment, as shown in Figure 8, differs from the valve timing adjustment device 100 of the first embodiment with respect to the configuration of a position-limiting section 80d. More precisely, the fifth embodiment's valve timing adjustment device 100d differs from the first embodiment's in that, instead of housing 120, it includes housing 120a, which is similar to housing 120a of the second embodiment, and furthermore, instead of retaining pin 40, it includes retaining pin 40d. Other parts are the same as in the first embodiment, so identical parts are indicated by the same reference numerals, and their detailed descriptions are omitted. Fig. Figure 8 shows, on an enlarged scale, a section of a cross-section which includes the outer end segment 56 and resembles the cross-section shown in Fig. 1 is shown.

[0066] The retaining pin 40d includes a section 80d with an enlarged diameter. This enlarged-diameter section 80d has a diameter larger than the diameter of the rest of the retaining pin 40d. In this configuration, the enlarged-diameter section 80d acts as the position-limiting section 80d and contacts the end surface on the camshaft 320 side of the outer end segment 56 in the axial direction AD. More precisely, the retaining pin 40d has the function of holding the outer end segment 56 of the support spring 50 and also functions as the position-limiting section 80d. The enlarged-diameter section 80d does not necessarily contact the outer end segment 56 and may, in the axial direction AD, contact the end surface on the camshaft 320 side of the helical segment 52.In the present embodiment, the enlarged-diameter section 80d extends completely around the retaining pin 40d. Alternatively, the enlarged-diameter section 80d can be formed on only a portion of the circumference of the retaining pin 40d such that, in the radial direction RD of the valve timing adjustment device 100d, the enlarged-diameter section 80d is formed at least on the inner side of the retaining pin 40d. Even in the present embodiment, the end is located on the side of the camshaft 320 of the straight section (which is in ). Fig. 8 not shown in detail) in the axial direction AD on the side of camshaft 320 of the end on the side of camshaft 320 of the contact section (which is in Fig. 8 is not shown in detail).

[0067] The valve timing adjustment device 100d of the fifth embodiment described above can achieve advantages similar to those of the valve timing adjustment device 100 of the first embodiment. In addition, it is possible to limit the increase in the number of parts, thereby limiting or preventing the complexity of the manufacturing process, since the section 80d with the increased diameter, which functions as the position limiting section 80d, is formed on the retaining pin 40d. F. Sixth embodiment

[0068] The valve timing adjustment device 100e of a sixth embodiment, which is in Fig. Figure 9 differs from the valve timing device 100a of the second embodiment with respect to the configuration of a position-limiting section 80e and the orientation of a support spring 50e. More precisely, the valve timing device 100e of the sixth embodiment differs in that, instead of the bushing component 10a, the support spring 50, and the retaining pin 40, the valve timing device 100e comprises a bushing component 10e, the support spring 50, and a retaining pin 40. Other parts are the same as in the second embodiment, so identical parts are indicated by the same reference numerals, and their detailed descriptions are omitted. Fig. Figure 9 shows, on an enlarged scale, a section of a cross-section similar to the cross-section shown in Fig. 1 is shown.

[0069] The bushing component 10e includes a large-diameter section 15e instead of the large-diameter section 15a. The radially outer surface of the large-diameter section 15e, located on the outer side in the radial direction RD, has a retaining section 26e that is recessed inwards in the radial direction RD and is located at a circumferential point on the radially outer surface of the large-diameter section 15e. The retaining section 26e of the sixth embodiment is formed at a point located in the axial direction AD on the side of the camshaft 320 corresponding to the location of the retaining section 26a of the second embodiment.In this configuration, the retaining section 26e functions as the position-limiting section 80e, and the retaining section 26e holds an inner end segment 54e of the support spring 50 and contacts an end surface of the inner end segment 54e that is located in the axial direction AD on the side of the camshaft 320. More precisely, the retaining section 26e also has the function of the position-limiting section 80e.

[0070] The support spring 50e is arranged by interchanging the left and right sides of the support spring 50 of the second embodiment in the axial direction AD. Therefore, the inner end segment 54e of the support spring 50e is located in the axial direction AD on the camshaft 320 side of an outer end segment 56e. A dimension of the retaining pin 40e, measured in the axial direction AD, is increased compared to a dimension of the retaining pin 40 of the second embodiment, measured in the axial direction AD, and the retaining pin 40e holds the outer end segment 56e of the support spring 50e. Even in the present embodiment, the end is located on the camshaft 320 side of the straight section (which is in Fig. 9 not shown in detail) in the axial direction AD on the side of camshaft 320 of the end on the side of camshaft 320 of the contact section (which is in Fig. 9 is not shown in detail).

[0071] The valve timing adjustment device 100e of the sixth embodiment described above can achieve advantages similar to those of the valve timing adjustment device 100a of the second embodiment. Since the inner end segment 54e of the support spring 50e is located in the axial direction AD on the side of the camshaft 320 of the outer end segment 56e, it is additionally possible to limit an excessive increase in the depth of the insertion hole 124, which is formed on the housing 120a and receives the retaining pin 40e. G. Seventh embodiment

[0072] A valve timing adjustment device 100f of a seventh embodiment, which is in Fig. Figure 10 differs from the valve timing adjustment device 100 of the first embodiment in that the position limitation section 80 has been eliminated and a support spring 50f has been provided instead of the support spring 50. Other parts are the same as in the first embodiment, so identical parts are indicated by the same reference numerals and their detailed descriptions are omitted. Fig. Figure 10 shows, on an enlarged scale, a section of a cross-section which includes a contact section 58f, as in Fig. 4.

[0073] The valve timing adjustment device 100f of the seventh embodiment includes housing 120a instead of housing 120, which is similar to housing 120a of the second embodiment. Therefore, the position limitation section 80 is eliminated or omitted.

[0074] The support spring 50f is a round wire spring made from wire with a circular cross-section. Therefore, the contact section 58f of the support spring 50f is intermittently formed on the radially inner surface of the support spring 50f. In the present embodiment, the radius r1 of the round wire of the spring is set such that it is greater than the sum of the length of the corner R1 of the bushing component 10, measured in the axial direction AD, and the length of the gap C between the sliding surface 17 and the outer surface 129 of the housing 120a, also measured in the axial direction AD.In other words, the radius r1 of the round wire of the spring is set such that it is larger than a dimension L2, which is measured in the axial direction AD between the end (end on the side of camshaft 320) of the straight section 25, which is located on the side of camshaft 320, and the housing 120a. In the above configuration, the end on the side of camshaft 320 of the straight section 25 is located in the axial direction AD on the side of camshaft 320 of the end on the side of camshaft 320 of the contact section 58f.

[0075] The valve timing adjustment device 100f of the seventh embodiment described above can achieve advantages similar to those of the valve timing adjustment device 100 of the first embodiment. In addition, the complexity of configuring the valve timing adjustment device 100f can be reduced because the position limitation section 80 is eliminated, and any increase in manufacturing costs can be limited. Furthermore, the spring constant of the support spring 50f can be reduced because the support spring 50f is a round wire spring, allowing it to be used within a suitable torque range. It is also possible to limit any increase in the cost of the support spring 50f because it is a round wire spring. H. Other embodiments (1) The configuration of the position-limiting section 80 of the first embodiment is merely an example and can be modified in various ways. For example, the position-limiting section 80 is formed by recessing the outer surface 129 relative to the position-limiting section 80 towards the side of the camshaft 320, so that the position-limiting section 80 protrudes in an annular shape over its entire circumference towards the side of the front cover 180. Alternatively, the position-limiting section 80 can be configured as in the valve timing adjustment device 100g, which is shown in Fig. Figure 11 shows a position-limiting section 80g, which projects in a ring shape, formed only at one location, which is the same as the location of the support spring 50 in the radial direction RD. Furthermore, the position-limiting section 80 does not necessarily project over its entire circumference towards the side of the front cover 180, for example, and can project from at least a portion of the entire circumference of a circle towards the side of the front cover 180. Additionally, the position-limiting section 80 can, for example, be formed according to the shape of the end surface on the side of the camshaft 320 of the support spring 50, and the end surface on the side of the camshaft 320 of the support spring 50 can contact the end surface in the axial direction AD along the entire circumference of the end surface on the side of the camshaft 320 of the support spring 50.Furthermore, the position-limiting section 80 is not necessarily configured such that it contacts the end surface on the side of the camshaft 320 of the helical segment 52. For example, the position-limiting section 80 can be configured as in a valve timing adjustment device 100h, which is located in . Fig. Figure 12 shows a position-limiting section 80h that projects from the housing 120 towards the side of the front cover 180 such that the position-limiting section 80h contacts the end surface on the side of the camshaft 320 of the outer end segment 56. More precisely, the position-limiting section 80 can generally be configured such that it projects from the housing 120 in the axial direction AD towards the opposite side, which is located in the axial direction AD opposite the side of the camshaft 320, such that the position-limiting section 80h contacts at least a portion of the end surface on the side of the camshaft 320 of the support spring 50. Even with this configuration, advantages similar to those of the first embodiment can be achieved. (2) In the first and third to fifth embodiments, the support spring 50 is arranged such that the outer end segment 56 is positioned in the axial direction AD on the side of the camshaft 320 of the inner end segment 54. However, even in the first and third to fifth embodiments, similar to the support spring 50e of the sixth embodiment described above, the inner end segment 54e can be positioned in the axial direction AD on the side of the camshaft 320 of the outer end segment 56e. Even in this configuration, the advantages similar to those of the first and third to fifth embodiments can be achieved. (3) In the first to sixth embodiments, the support spring 50 is the rectangular wire spring made from wire having a rectangular cross-section. Alternatively, the support spring 50 can be a round wire spring made from wire having a circular cross-section. Even in this configuration, advantages similar to those of the first to sixth embodiments can be achieved. (4) In the first to sixth embodiments, the end is located on the side of the camshaft 320 of the straight section 25 in the axial direction AD on the side of the camshaft 320 of the contact section 58, 58f. Alternatively, the location of the end on the side of the camshaft 320 of the straight section 25 in the axial direction AD can coincide with the location of the end on the side of the camshaft 320 of the contact section 58, 58f. More precisely, in general, the location of the end on the side of the output shaft 320 of the straight section 25 in the axial direction AD can coincide with the location of the end on the side of the output shaft 320 of the contact section 58, 58f, or it can be located on the side of the output shaft 320 at the location of the end on the side of the output shaft 320 of the contact section 58, 58f.Even with this configuration, the advantages can be achieved that are similar to those of the first to sixth embodiments. (5) The valve timing adjustment device 100, 100a-100f of each of the foregoing embodiments includes the retaining pin 40, 40d, 40e. Alternatively, the retaining pin 40, 40d, 40e can be eliminated, and a projection having an outer shape similar to the outer shape of the retaining pin 40, 40d, 40e can be formed integrally with the housing 120, 120a. The projection retains the outer end segment 56 of the support spring 50. With this modification, the number of parts can be reduced, and a machining step for the insertion hole 124 can be eliminated. Furthermore, a projection 45i, which has an outer shape similar to the outer shape of the retaining pin 40d of the valve timing adjustment device 100d of the fifth embodiment, can be provided in this modification, as in a valve timing adjustment device 100i which is in Fig.As shown in Figure 13, the projection 45i is formed integrally with the housing 120a in one piece. The projection 45i includes a section 80i with an enlarged diameter, which has an outer diameter larger than the diameter of the rest of the projection 45i. The section 80i with the enlarged diameter acts as a position-limiting section 80i and contacts the end surface on the side of the camshaft 320 of the outer end segment 56. Furthermore, as in the sixth embodiment, the support spring 50e can be used, in which the inner end segment 54e is located in the axial direction AD on the side of the camshaft 320 of the outer end segment 56e. More precisely, the projection 45i, which is formed integrally with the housing 120a in one piece, can have the function of holding the outer end segment 56, 56e of the support spring 50, 50e and the function of the position-limiting section 80i.Even with this configuration, the advantages can be achieved which are similar to those of the respective embodiments described above. (6) The configuration of the valve timing adjustment device 100, 100a-100f of the respective embodiments described above is merely an example and can be modified in various ways. For example, a stopper may be provided that limits the axial displacement of the support spring 50, 50e, 50f towards the side of the front cover 180 in the direction AD. This stopper may be designed such that it projects outwards in the radial direction RD from the end portion on the side of the front cover 180 of the bushing component 10, 10a, 10c, 10e. This stopper may extend over the entire circumference of the bushing component 10, 10a, 10c, 10e, or it may be formed on only a portion of the entire circumference of the bushing component 10, 10a, 10c, 10e.If this stopper contacts at least a section of the end surface on the side of the front cover 180 of the support spring 50, 50e, 50f in the axial direction AD, it is possible to further reduce the contact area between the support spring 50, 50e, 50f and the bushing component 10, 10a, 10c, 10e. Furthermore, the support spring 50, 50e, 50f can bias the vane rotor 130 in the deceleration direction relative to the housing 120, 120a, for example, instead of in the forward displacement direction. Additionally, the hydraulic oil control valve 350 can be positioned, for example, along the axis of rotation AX of the valve timing adjustment device 100, 100a-100f, instead of the central bolt 190. Furthermore, the valve timing adjustment device 100, 100a-100f is configured to adjust the valve timing of the exhaust valves, which are driven by the camshaft 320 in such a way that they open and close.Alternatively, the valve timing adjustment device 100, 100a-100f can be configured to adjust the valve timing of the intake valves. Furthermore, the valve timing adjustment device 100, 100a-100f can be used such that it is fixed to the end section of the camshaft 320 (which serves as the output shaft), which receives the driving force from the crankshaft 310 (which serves as the input shaft) via an intermediate shaft. Alternatively, the valve timing adjustment device 100, 100a-100f can be used such that it is installed at the end section of a dual-structure camshaft consisting of an input shaft and an output shaft.

[0076] The present disclosure is not limited to the embodiments described above and can be implemented in various configurations without departing from the fundamental concept of the present disclosure. For example, the technical features of each embodiment that correspond to the technical features in the summary section of the present disclosure can be suitably substituted or combined to overcome some or all of the disadvantages described above or to achieve some or all of the advantages described above. If the technical feature(s) are not described as essential in the description, they may be omitted where appropriate.

Claims

[1] Valve timing adjustment device (100, 100a-100i) to be installed on an end section of an output shaft (320) located in an axial direction (AD) at one end of the output shaft, wherein the output shaft is configured to receive a drive force transmitted from a drive shaft (310) in an internal combustion machine (300), and the valve timing adjustment device is configured to use hydraulic pressure to adjust the timing of a valve driven by the output shaft such that it opens and closes, wherein the valve timing adjustment device comprises: a housing (120, 120a) configured to rotate synchronously with the drive shaft; a vane rotor (130) which is received in an interior of the housing and divides the interior of the housing into a plurality of hydraulic chambers (140), wherein the vane rotor is configured to be rotated synchronously with the output shaft; a support spring (50, 50e, 50f) configured to bias the vane rotor relative to the housing in a forward displacement direction or a retardation direction, the support spring comprising: a twisted segment (52); an inner end segment (54, 54e) which is joined to one end of the coiled segment and projects inwards in a radial direction (RD); and an outer end segment (56, 56e) which is joined to another end of the coiled segment and projects outwards in the radial direction; and a bushing component (10, 10a, 10c, 10e) that is fixed to the wing rotor, wherein: The bushing component is formed in a stepped cylindrical tubular shape and includes the following: a large-diameter section (15, 15a, 15c, 15e) formed in a cylindrical tubular shape and located on a radially inner side of the coiled segment, the large-diameter section comprising a straight section (25) located on a radially outer surface of the large-diameter section and extending in the axial direction; and a small-diameter section (13) formed in a cylindrical tubular shape and connected to the large-diameter section on an axial side of the large-diameter section on which the output shaft is placed, wherein the small-diameter section is placed on a radially inner side of the housing and has an outer diameter that is smaller than an outer diameter of the large-diameter section; the coiled segment includes a contact section (58, 58f) located on a radially inner surface of the coiled segment and configured to contact the straight section; and a point of an end of the straight section, which is located on one axial side on which the output shaft is placed, coincides in the axial direction with a point of an end of the contact section, which is located on one axial side, or which is one axial side of the point of the end of the contact section. [2] Valve timing adjustment device according to claim 1, further comprising a position limitation section (80, 80a-80e, 80g-80i) configured to limit a position of the support spring relative to the bushing component in the axial direction. [3] Valve timing adjustment device according to claim 2, wherein the position limiting section on the housing projects axially towards another axial side which is arranged opposite the output shaft and contacts at least a section of an end surface of the support spring which is located on the one axial side on which the output shaft is placed. [4] Valve timing adjustment device according to claim 2, wherein the position limiting section is radially recessed inwards on the radially outer surface of the large diameter section and contacts an end surface of the inner end segment which is located on the one axial side on which the output shaft is placed. [5] Valve timing adjustment device according to claim 2, wherein: the position restriction section is formed by an intermediate component (80b); and a surface of the position limiting section located on one axial side contacts the housing, and another surface of the position limiting section located on another axial side, which is arranged opposite the output shaft, contacts at least a section of an end surface of the support spring located on one axial side on which the output shaft is placed. [6] Valve timing adjustment device according to claim 2, wherein the position limiting section projects radially outwards on the large diameter section and contacts at least one section of an end surface of the support spring located on the axial side on which the output shaft is placed. [7] Valve timing adjustment device according to claim 2, further comprising a retaining pin (40, 40d, 40e) which is inserted into an insertion hole (124) of the housing which extends in the axial direction and is configured to retain the outer end segment, wherein the position limiting section is formed by a section (80d) with an enlarged diameter of the retaining pin which has an outer diameter which is larger than the outer diameter of a remaining retaining pin and contacts an end surface of the support spring which is located on the one axial side on which the output shaft is placed. [8] Valve timing adjustment device according to any one of claims 1 to 7, wherein the support spring is formed by a wire having a circular cross-section. [9] Valve timing adjustment device according to claim 8, wherein a radius (r1) of the wire is larger than a dimension (L2) measured in the axial direction between the end of the straight section located on the one axial side on which the output shaft is placed and the housing. [10] Valve timing adjustment device according to any one of claims 2 to 7, wherein the support spring is made of a wire having a rectangular cross-section. [11] Valve timing adjustment device according to one of claims 1 to 10, wherein the outer end segment is located in the axial direction on one axial side of the inner end segment on which the output shaft is placed. [12] Valve timing adjustment device according to one of claims 1 to 10, wherein the inner end segment is located in the axial direction on one axial side of the outer end segment on which the output shaft is placed.

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