JPWO2020194679A1 - Tensioner lifter - Google Patents

Abstract

The tensioner lifter (25) is pressed against the drive shaft (38) in the axial direction, and resists the rotation of the drive shaft (38) around the axis (27) according to the friction torque with the drive shaft (38). A friction member (55) to be applied and an elastic member (58) to apply a pressing force to the friction member (55) toward the thrust member (26a) in the axial direction are provided. At the shaft end of the drive shaft (38), the thrust extends outward from the virtual cylindrical surface (62) coaxial with the axis (27) and inscribed in the point of action of the elastic member (58) with respect to the friction member (55). A large-diameter shaft (41) to be received by the member (26a) is formed. This provides a tensioner lifter capable of generating a stable friction torque with respect to the drive shaft.

Description

The present invention includes a drive shaft that is rotatably supported around an axis and has a male screw engraved on the shaft body, and a thrust member that supports the shaft end of the drive shaft in the thrust direction while restraining the displacement of the drive shaft in the radial direction. , A propulsion body having a female screw that meshes with the male screw on the inner surface, which is restrained relative to the thrust member in a relative non-rotatable manner around the axis, and an elastic force that drives the drive shaft around the axis, depending on the meshing of the male screw and the female screw. The present invention relates to a tensioner lifter provided with a spring that applies a propulsive force to the propulsion body in a direction away from the thrust member.

U.S. Pat. In the tensioner lifter, the drive shaft is received by the thrust member at the shaft end. At the shaft end of the drive shaft, a stepped surface is formed to receive the friction member of the annular plate pressed against the thrust member. The friction member imparts a resistance force to the rotation of the drive shaft around the axis according to the friction torque with the drive shaft. The rotation of the drive shaft is moderately constrained. Therefore, the propulsive force of the propulsion body is stabilized.

Japanese Patent No. 4934816

When the friction torque is generated, the string-wound spring presses the friction member against the stepped surface. At this time, the string-wound spring is pressed against the friction member on the outer side in the radial direction from the stepped surface. Since the diameter of the shaft end of the drive shaft is smaller than the diameter of the string-wound spring, there is a concern that the drive shaft is unstablely supported by the thrust member. The generation of good friction torque cannot be realized. On the other hand, if a large spring load is applied to the string-wound spring for the purpose of stabilizing the friction torque, there is a concern that the pressing force applied to the cam chain becomes too high.

The present invention has been made in view of the above circumstances, and provides a tensioner lifter capable of generating stable friction torque with respect to the drive shaft and avoiding excessive load on the cam chain. With the goal.

According to the first aspect of the present invention, a drive shaft having a male screw that is rotatably supported around an axis and is engraved on the shaft body, and the drive shaft in the thrust direction while restraining the displacement of the drive shaft in the radial direction. A thrust member that supports the shaft end, a propulsion body that is restrained relative to the thrust member so as not to rotate relative to the shaft end and has a female screw that meshes with the male screw on the inner surface, and drives the drive shaft around the shaft line. A spring that generates an elastic force and applies a propulsive force to the propulsion body in a direction away from the thrust member according to the engagement of the male screw and the female screw, and a spring that is pressed against the drive shaft in the axial direction and around the axis. In a tensioner lifter including a friction member that generates a frictional force with the drive shaft and an elastic member that urges the friction member toward the thrust member in the axial direction, the shaft end of the drive shaft. A large-diameter shaft that is coaxial with the axis and extends outward from the virtual cylindrical surface inscribed in the point of action of the elastic member with respect to the friction member and is received by the thrust member is formed.

According to the second aspect of the present invention, a drive shaft having a male screw that is rotatably supported around an axis and is engraved on the shaft body, and the drive shaft in the thrust direction while restraining the displacement of the drive shaft in the radial direction. A thrust member that supports the shaft end, a propulsion body that is restrained relative to the thrust member so as not to rotate relative to the shaft end and has a female screw that meshes with the male screw on the inner surface, and drives the drive shaft around the shaft line. A spring that generates an elastic force and applies a propulsive force to the propulsion body in a direction away from the thrust member according to the engagement of the male screw and the female screw, and a spring that is pressed against the drive shaft in the axial direction and around the axis. In a tensioner lifter including a friction member that generates a frictional force with the drive shaft and an elastic member that urges the friction member toward the thrust member in the axial direction, the drive shaft is the thrust. Between a large-diameter shaft that is accepted in a recess formed in a member and a cylindrical body that is coaxial with the axis and has a smaller diameter than the large-diameter shaft and is coupled to the large-diameter shaft in the axial direction. Is provided with a medium-diameter shaft that forms a first stepped surface.

According to the third side surface, in addition to the configuration of the second side surface, the male screw is formed to have a smaller diameter than the large diameter shaft.

According to the fourth side surface, in addition to the configuration of any one of the first to third side surfaces, the elastic member is provided so as to be rotatable relative to the friction member.

According to the fifth side surface, in addition to the configuration of any one of the first to fourth side surfaces, the tensioner lifter surrounds the propulsion body and has one end located on the friction member side of the propulsion body in the axial direction. The elastic member is sandwiched between the one end of the collar member and the friction member on the friction member side of the propulsion body in the axial direction.

According to the sixth side surface, in addition to the configuration of the fifth side surface, the friction member or the collar member is formed with a boss that regulates the displacement of the elastic member in the radial direction.

According to the seventh aspect of the present invention, a drive shaft having a male screw rotatably supported around an axis and carved on the shaft body, and the drive shaft in the thrust direction while restraining the displacement of the drive shaft in the radial direction. A thrust member that supports the shaft end, a propulsion body that is restrained relative to the thrust member so as not to rotate relative to the shaft end and has a female screw that meshes with the male screw on the inner surface, and drives the drive shaft around the shaft line. A spring that generates an elastic force and applies a propulsive force to the propulsion body in a direction away from the thrust member according to the engagement of the male screw and the female screw, and a spring that is pressed against the drive shaft in the axial direction and around the axis. In a tensioner lifter including a friction member that generates a frictional force with the drive shaft and an elastic member that urges the friction member toward the thrust member in the axial direction, the propulsion body is surrounded by the above. The elastic member includes a collar member having one end located on the friction member side of the propulsion body in the axial direction, and the elastic member has the one end of the collar member and the elastic member on the friction member side of the propulsion body in the axial direction. It is sandwiched between the friction member and the friction member.

According to the eighth aspect of the present invention, a drive shaft having a male screw that is rotatably supported around an axis and is engraved on the shaft body, and the drive shaft in the thrust direction while restraining the displacement of the drive shaft in the radial direction. A thrust member that supports the shaft end, a propulsion body that is constrained to the thrust member so as to be relatively non-rotatable around the axis and has a female screw that meshes with the male screw on the inner surface, and drives the drive shaft around the axis. In a tensioner lifter provided with a spring that generates an elastic force and applies a propulsive force to the propulsion body in a direction away from the thrust member according to the engagement of the male screw and the female screw, the tensioner lifter is pressed against the drive shaft in the axial direction. Provided with an elastic member that applies a pressing force to the drive shaft toward the thrust member.

According to the ninth aspect, in addition to the configuration of the eighth aspect, the tensioner lifter comprises a collar member that surrounds the propellant and is immovably constrained in a direction away from the thrust member, the collar member and said. The elastic member is arranged between the drive shaft and the elastic member.

According to the first aspect, a driving force is applied to the driving shaft around the axis by the action of the spring. When the drive shaft rotates, propulsive force is applied to the propulsion body according to the engagement of the male and female threads. At this time, the friction member applies a resistance force to the rotation of the drive shaft around the axis according to the friction torque with the drive shaft. The rotation of the drive shaft is moderately constrained. Therefore, the propulsive force of the propulsion body is stabilized. Since the drive shaft is received by the thrust member by a large-diameter shaft extending outward from the point of action of the elastic member, the drive shaft can be stably supported by the thrust member. Friction torque can be satisfactorily generated between the thrust member and the large-diameter shaft.

According to the second aspect, a driving force is applied to the driving shaft around the axis by the action of the spring. When the drive shaft rotates, propulsive force is applied to the propulsion body according to the engagement of the male and female threads. At this time, the friction member applies a resistance force to the rotation of the drive shaft around the axis according to the friction torque with the drive shaft. The rotation of the drive shaft is moderately constrained. Therefore, the propulsive force of the propulsion body is stabilized. Since the drive shaft is received by the thrust member by a large diameter shaft extending outward from the medium diameter shaft, the drive shaft can be stably supported by the thrust member. Friction torque can be satisfactorily generated between the thrust member and the large-diameter shaft.

According to the third aspect, since the male screw is formed to have a smaller diameter than the large diameter shaft, the drive shaft can be stably supported with respect to the thrust member.

According to the fourth aspect, since relative rotation is allowed between the elastic member and the friction member, twisting of the elastic member can be prevented. The elastic member can appropriately exert an elastic force on the friction member.

According to the fifth aspect, the collar member can realize the shortening of the elastic member in the axial direction. Therefore, the behavior of the elastic member can be stabilized. Since the collar member is partially replaced with the elastic member, it is possible to reduce the use of the relatively expensive elastic member and reduce the manufacturing cost.

According to the sixth aspect, since the position of the elastic member is set in the radial direction with respect to the friction member, the elastic member can act on the friction member with a force balanced in the circumferential direction. Friction torque can be satisfactorily generated between the thrust member and the large-diameter shaft.

According to the seventh aspect, the collar member can realize the shortening of the elastic member in the axial direction. Therefore, the behavior of the elastic member can be stabilized. Since the collar member is partially replaced with the elastic member, it is possible to reduce the use of the relatively expensive elastic member and reduce the manufacturing cost.

According to the eighth aspect, since the elastic member is directly pressed against the drive shaft, the number of parts can be reduced as compared with the case where another member is interposed between the elastic member and the drive shaft. As the number of parts is reduced, the number of connected parts between parts is reduced, so that the risk of malfunction can be reduced.

According to the ninth aspect, the collar member can realize the shortening of the elastic member in the axial direction. Therefore, the behavior of the elastic member can be stabilized. Since the collar member is partially replaced with the elastic member, it is possible to reduce the use of the relatively expensive elastic member and reduce the manufacturing cost.

FIG. 1 is a vertical sectional side view of an internal combustion engine according to an embodiment of the present invention. (First Embodiment) FIG. 2 is an enlarged cross-sectional view of the tensioner lifter according to the first embodiment observed on the cut surface including the axis. (First Embodiment) FIG. 3 is a three-arrow view of FIG. (First Embodiment) FIG. 4 is a four-arrow view of FIG. (First Embodiment) FIG. 5 corresponds to a partially enlarged view of FIG. 2, and is a conceptual diagram schematically showing a stopper inserted into the drive shaft. (First Embodiment) FIG. 6 is an enlarged cross-sectional view of the tensioner lifter according to the second embodiment observed on the cut surface including the axis. (Second embodiment) FIG. 7 is an enlarged cross-sectional view of the tensioner lifter according to the third embodiment observed on the cut surface including the axis. (Third embodiment) FIG. 8 is an enlarged cross-sectional view of the tensioner lifter according to the fourth embodiment observed on the cut surface including the axis. (Fourth Embodiment) FIG. 9 is an enlarged cross-sectional view of the tensioner lifter according to the fifth embodiment observed on the cut surface including the axis. (Fifth Embodiment)

25 ... Tensioner lifter 25a ... Tensioner lifter 25b ... Tensioner lifter 25c ... Tensioner lifter 26a ... Thrust member 27 ... Axis line 28 ... Propulsion body 36 ... Shaft body 37 ... Male screw 38 ... Drive shaft 41 ... Large diameter shaft 43 ... Medium diameter shaft 46 ... Spring (spring)
48 ... Female screw 55 ... Friction member 56 ... Collar member 56a ... One end 58 ... Elastic member (belleville spring)
59 ... Boss 62 ... Virtual cylindrical surface 71 ... Friction member 72 ... Color member 72a ... One end 75 ... Elastic member (O-ring)
76 ... Boss 78 ... Virtual cylindrical surface 82 ... Elastic member (string-wound spring)
91 ... Color member 94 ... Elastic member (disc spring)
101 ... Friction member 103 ... Elastic member (tsurumaki spring)
105 ... Virtual cylindrical surface

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

First Embodiment

FIG. 1 schematically shows an internal combustion engine according to an embodiment of the present invention. The internal combustion engine 11 guides a linear reciprocating motion of a crank case 13 that rotatably supports the crankshaft 12 around the rotation axis Rx, and a piston that is coupled to the crankcase 13 and connected to the crankshaft 12 by a connecting rod. A cylinder block 14, a cylinder head 15 coupled to the cylinder block 14 to partition the combustion chamber from the piston, and a movement controlled to open and close the intake valve and the exhaust valve facing the combustion chamber by being coupled to the cylinder head 15. A head cover 16 for accommodating a valve mechanism is provided. When the piston descends and the intake valve opens, the air-fuel mixture is introduced into the combustion chamber. When the intake valve closes and the piston rises, the air-fuel mixture is compressed in the combustion chamber. When the air-fuel mixture is ignited in the combustion chamber, the air-fuel mixture burns and the volume of the combustion chamber expands. Along with this, the piston descends, and when the exhaust valve opens as the piston continues to rise, exhaust gas is discharged from the combustion chamber. In this way, power is taken out from the crankshaft 12.

The internal combustion engine 11 incorporates a valve operating mechanism 17 that realizes an opening / closing operation of the intake valve and the exhaust valve at a predetermined timing according to the linear reciprocating motion of the piston. The valve operating mechanism 17 is driven by a drive sprocket 18 fixed to the crankshaft 12 and rotating around the rotation axis Rx, and a driven sprocket 21 fixed to the camshaft 19 and rotating around the rotation axis Xc of the camshaft 19. It includes an annular cam chain 22 that is wound around the sprocket 18 and the driven sprocket 21. The rotation of the crankshaft 12 is transmitted to the camshaft 19 by the action of the cam chain 22. The cam chain 22 becomes tense in the region pulled from the driven sprocket 21 to the driven sprocket 18 and relaxes in the region returning from the driven sprocket 18 to the driven sprocket 21.

The valve operating mechanism 17 includes a chain guide 23 that contacts the cam chain 22 on the tension side of the cam chain 22 and a tensioner 24 that contacts the cam chain 22 on the loose side of the cam chain 22 to apply tension to the cam chain 22. Are combined. The chain guide 23 extends linearly along the trajectory of the cam chain 22 on the tension side from the position outside the centrifugal direction of the driven sprocket 21 to the position outside the centrifugal direction of the driving sprocket 18. The tensioner 24 extends along the trajectory of the cam chain 22 on the relaxation side from the position outside the centrifugal direction of the drive sprocket 18 to the position outside the centrifugal direction of the driven sprocket 21. The tensioner 24 is curved so as to bulge toward the trajectory of the cam chain 22 on the tension side. A pressing pressure acts on the cam chain 22 on the relaxation side from the tensioner 24 toward the trajectory of the cam chain 22 on the tension side. The determined tension can be maintained in the cam chain 22 on the relaxation side by the action of the pressing pressure applied from the tensioner 24.

The tensioner 24 is swingably connected to the crankcase 13 around the swing axis Sx on the outside of the track of the cam chain 22 on the relaxation side. The swing axis Sx is located parallel to the rotation axis Rx of the crankshaft 12. A tensioner lifter 25 that exerts a driving force on the tensioner 24 in a tangential direction around the swing axis Sx is connected to the tensioner 24 at a position away from the swing axis Sx. The tensioner 24 can apply tension to the cam chain 22 on the relaxation side according to the driving force of the tensioner lifter 25.

The tensioner lifter 25 includes a casing 26 coupled to the cylinder block 14 and a propulsion body 28 that projects from the casing 26 so as to be displaceable in the axis 27 direction and is pressed against the tensioner 24 at the tip. The axis 27 is tangentially located around the swing axis Sx and intersects the trajectory of the cam chain 22 on the relaxation side. The cylinder block 14 is formed with a mounting seat 32 that surrounds the mounting hole 29 and receives the casing 26 on the seat surface 31 orthogonal to the axis 27.

The casing 26 closes the mounting hole 29 from the outside of the cylinder block 14, and has a thrust member 26a fastened to the mounting seat 32 with two bolts 33 and a surrounding wall 26b extending in a cylindrical shape in the axial direction from the thrust member 26a. Be prepared. A plug member 34 coaxial with the axis 27 is screwed into the thrust member 26a from the outside of the cylinder block 14.

As shown in FIG. 2, the tensioner lifter 25 according to the first embodiment includes a drive shaft 38 having a male screw 37 rotatably supported by a thrust member 26a around an axis 27 and engraved on a shaft body 36. The drive shaft 38 has a large-diameter shaft 41 formed of a cylindrical body coaxial with the axis 27 and received in a recess 39 formed in the thrust member 26a, and a cylindrical body coaxial with the axis 27 and having a smaller diameter than the large-diameter shaft 41. A medium-diameter shaft 43 is provided, which is formed of the above-mentioned surface and is coupled to the large-diameter shaft 41 in the axial direction to form a first stepped surface 42 with the large-diameter shaft 41. The shaft body 36 is formed of a cylindrical body having a diameter smaller than that of the medium diameter shaft 43, and is coupled to the medium diameter shaft 43 in the axial direction. The shaft body 36 forms a second stepped surface 44 with the medium diameter shaft 43. The drive shaft 38 is formed from, for example, a metal material.

A cup washer 45 is attached to the large diameter shaft 41 of the drive shaft 38. The cup washer 45 covers the end surface of the large-diameter shaft 41 along the outer circumference and also covers the outer peripheral surface of the large-diameter shaft 41. The cup washer 45 is fitted into the recess 39 of the thrust member 26a. The recess 39 constrains the displacement of the drive shaft 38 in the radial direction. The cup washer 45 is sandwiched between the thrust member 26a and the large-diameter shaft 41 by the recess 39, and functions to prevent the large-diameter shaft 41 from rattling with respect to the recess 39.

A spring 46 is mounted on the outer circumference of the medium-diameter shaft 43 of the drive shaft 38. The mainspring 46 generates an elastic force that drives the drive shaft 38 around the axis 27. The mainspring 46 exerts an elastic force for driving the drive shaft 38 in the direction of rotation protruding with respect to the female screw.

The propulsion body 28 is attached to the shaft body 36 from the tip (open end). The propulsion body 28 includes a tubular body 28a that coaxially divides the through hole 47 with the shaft body 36, and a cap 28b that closes the through hole 47 at the open end of the tubular body 28a and is pressed against the tensioner 24. The cylinder 28a and the cap 28b are each molded from, for example, a metal material.

A female screw 48 that meshes with the male screw 37 of the shaft body 36 is engraved on the inner surface of the through hole 47. The propulsion body 28 is restrained so as to be unable to rotate relative to the thrust member 26a around the axis 27. When the drive shaft 38 rotates according to the elastic force of the spring 46, the propulsion body 28 advances in a direction away from the thrust member 26a according to the engagement of the male screw 37 and the female screw 48. When the drive shaft 38 rotates in the opposite direction against the elastic force of the spring 46, the propulsion body 28 retracts toward the thrust member 26a according to the engagement of the male screw 37 and the female screw 48.

The propulsion body 28 penetrates the guide 51 coupled to the enclosure wall 26b of the casing 26. The guide 51 is formed with an opening 51a for receiving the propulsion body 28 so as to be freely displaced in the axial direction. As shown in FIG. 3, the opening 51a is partitioned by a contour other than a circle. Here, the opening 51a partitions a cylindrical space that partially partitions a plane. The opening 51a constrains the relative rotation of the propulsion body 28 with respect to the guide 51 around the axis 27. The guide 51 is formed from, for example, a metal material.

The guide 51 is formed with an arm piece 52 extending in four directions in the radial direction. The individual arm pieces 52 are received by a notch 53 formed at the tip of the enclosure wall 26b. The arm piece 52 restrains the rotation of the guide 51 around the axis 27. In this way, the guide 51 functions as a detent for the propulsion body 28 around the axis 27 while allowing displacement of the propulsion body 28 in the axial direction. The individual arm pieces 52 are constrained within the notch 53 by a C-clip 54 mounted on the outer peripheral surface of the enclosure wall 26b.

As shown in FIG. 2, the friction member 55 is received on the second step surface 44 from the axial direction. The friction member 55 is formed of an annular flat plate surrounding the shaft body 36. The friction member 55 is formed from, for example, a metal material. The friction member 55 is pressed against the second stepped surface 44 in the axial direction.

A collar member 56 is mounted on the outer periphery of the propulsion body 28 between the guide 51 and the friction member 55 in the axial direction. The collar member 56 is formed in a cylindrical shape surrounding the propulsion body 28, and has one end 56a located on the friction member 55 side of the propulsion body 28 in the axial direction. A flange 57 extending radially outward is formed at one end 56a of the collar member 56. The color member 56 is molded from, for example, a resin material or a metal material.

A disc spring (elastic member) 58 is sandwiched between the flange 57 of the collar member 56 and the friction member 55 on the friction member 55 side of the propulsion body 28 in the axial direction. Since the other end 56b of the collar member 56 is restrained by the guide 51, the disc spring 58 exerts an elastic force that applies a pressing force to the friction member 55 toward the thrust member 26a in the axial direction. The disc spring 58 is received by the friction member 55 so as to be relatively rotatable. On the inner circumference of the friction member 55, a boss 59 that stands up in a direction away from the thrust member 26a and regulates the displacement of the disc spring 58 in the radial direction is formed. Here, the large-diameter shaft 41 extends outward from the virtual cylindrical surface 62 that is coaxial with the axis 27 and is inscribed in the action point 61 of the disc spring 58 with respect to the friction member 55. Further, the large-diameter shaft 41 extends outward from the virtual cylindrical surface 63 coaxial with the axis 27 and inscribed by the disc spring 55.

A grind 64 is formed on the large-diameter shaft 41 of the drive shaft 38 along a virtual plane including the axis 27. The thrust member 26a is formed with a through hole 65 that opens in the recess 39 and is closed by the plug member 34. The through hole 65 partitions the cylindrical space coaxially with the axis 27. As shown in FIG. 4, a groove 66 extending on a three-diameter line is formed on the outer surface of the thrust member 26a around the through hole 65.

As shown in FIG. 5, a stopper 67 is inserted into the grind 64 through the through hole 65 prior to the closure of the plug member 34. The mainspring 46 can be wound according to the rotation of the stopper 67. By being wound, elastic force is accumulated in the mainspring 46. The stopper 67 can be fitted into the groove 66 at a specific rotation position. In this way, the rotational position of the drive shaft 38 can be constrained by the action of the stopper 67. After the stopper 67 is removed, the through hole 65 is closed with the plug member 34.

By the action of the mainspring 46, a driving force is applied to the drive shaft 38 around the axis 27. When the drive shaft 38 rotates, a propulsive force is applied to the propulsion body 28 according to the engagement of the male screw 37 and the female screw 48. At this time, the friction member 55 applies a resistance force to the rotation of the drive shaft 38 around the axis 27 according to the friction torque with the drive shaft 38. Similarly, the large-diameter shaft 41 imparts resistance to the rotation of the drive shaft 38 around the axis 27 according to the friction torque with the cup washer 45. In this way, the rotation of the drive shaft 38 is appropriately restrained. Therefore, the propulsive force of the propulsion body 28 is stabilized. Since the drive shaft 38 is received by the thrust member 26a by the large-diameter shaft 41 having a diameter larger than that of the medium-diameter shaft 43 that spreads outward from the action point 61 of the disc spring 58 and receives the mainspring 46, the drive shaft 38 is received by the thrust member 26a with respect to the thrust member 26a. The drive shaft 38 can be stably supported. Friction torque can be satisfactorily generated between the thrust member 26a and the large-diameter shaft 41.

In the present embodiment, the disc spring 58 is sandwiched between one end 56a of the collar member 56 and the friction member 55 on the friction member 55 side of the propulsion body 28 in the axial direction. The collar member 58 realizes a shortening of the elastic member that exerts the pressing force of the friction member 55, and realizes the adoption of a disc spring 58 instead of a long string-wound spring. The behavior of the elastic member is stabilized. Since the collar member 58 is partially replaced with the elastic member, the use of the relatively expensive elastic member can be reduced and the manufacturing cost can be reduced.

The friction member 55 is formed with a boss 59 that regulates the displacement of the disc spring 58 in the radial direction. Since the position of the disc spring 58 is set in the radial direction with respect to the friction member 55, the disc spring 58 can act on the friction member 55 with a force balanced in the circumferential direction. Friction torque can be satisfactorily generated between the thrust member 26a and the large-diameter shaft 41.

Second embodiment

As shown in FIG. 6, the tensioner lifter 25a according to the second embodiment includes a friction member 71 that is received by the second step surface 44 from the axial direction. The friction member 71 is formed of an annular flat plate surrounding the shaft body 36. The friction member 71 is formed from, for example, a metal material. The friction member 71 is pressed against the second stepped surface 44 in the axial direction.

A collar member 72 is mounted on the outer periphery of the propulsion body 28 between the guide 51 and the friction member 71 in the axial direction. The collar member 72 is formed in a cylindrical shape surrounding the propulsion body 28, and has one end 72a located on the friction member 71 side of the propulsion body 28 in the axial direction. A flange 73 extending radially outward is formed at one end 72a of the collar member 72. The color member 72 is molded from, for example, a resin material or a metal material. The propulsion body 28 is formed with a positioning piece 74 that is inscribed in the collar member 72 and restrains the displacement of the collar member 72 in the radial direction.

An O-ring (elastic member) 75 is sandwiched between the flange 73 of the collar member 72 and the friction member 71 on the friction member 71 side of the propulsion body 28 in the axial direction. Since the other end 72b of the collar member 72 is restrained by the guide 51, the O-ring 75 exerts an elastic force that applies a pressing force to the friction member 71 toward the thrust member 26a in the axial direction. The O-ring 75 is received by the friction member 71 so as to be relatively rotatable. On the inner circumference of the friction member 71, a boss 76 that stands up in a direction away from the thrust member 26a and regulates the displacement of the O-ring 75 in the radial direction is formed. Here, the large-diameter shaft 41 of the drive shaft 38 extends outward from the virtual cylindrical surface 78 that is coaxial with the axis 27 and is inscribed in the action point 77 of the O-ring 75 with respect to the friction member 71. Further, the large-diameter shaft 41 extends outward from the virtual cylindrical surface 79 that is coaxial with the axis 27 and is inscribed by the O-ring 75. Other configurations are the same as those of the tensioner lifter 25 described above.

By the action of the mainspring 46, a driving force is applied to the drive shaft 38 around the axis 27. When the drive shaft 38 rotates, a propulsive force is applied to the propulsion body 28 according to the engagement of the male screw 37 and the female screw 48. At this time, the friction member 71 applies a resistance force to the rotation of the drive shaft 38 around the axis 27 according to the friction torque with the drive shaft 38. Similarly, the large-diameter shaft 41 imparts resistance to the rotation of the drive shaft 38 around the axis 27 according to the friction torque with the cup washer 45. In this way, the rotation of the drive shaft 38 is appropriately restrained. Therefore, the propulsive force of the propulsion body 28 is stabilized. Since the drive shaft 38 is received by the thrust member 26a by the large-diameter shaft 41 having a diameter larger than that of the medium-diameter shaft 43 that spreads outward from the action point 77 of the O-ring 75 and receives the mainspring 46, the drive shaft 38 is received by the thrust member 26a with respect to the thrust member 26a. The drive shaft 38 can be stably supported. Friction torque can be satisfactorily generated between the thrust member 26a and the large-diameter shaft 41.

In the present embodiment, the O-ring 75 is sandwiched between one end 72a of the collar member 72 and the friction member 71 on the friction member 71 side of the propulsion body 28 in the axial direction. The collar member 72 realizes a shortening of the elastic member that exerts the pressing force of the friction member 71, and realizes the adoption of an O-ring 75 instead of a long string-wound spring. The behavior of the elastic member is stabilized. Since the collar member 72 is partially replaced with the elastic member, the use of the relatively expensive elastic member can be reduced and the manufacturing cost can be reduced.

The friction member 71 is formed with a boss 76 that regulates the displacement of the O-ring 75 in the radial direction. Since the position of the O-ring 75 is set in the radial direction with respect to the friction member 71, the O-ring 75 can act on the friction member 71 with a force balanced in the circumferential direction. Friction torque can be satisfactorily generated between the thrust member 26a and the large-diameter shaft 41.

Third embodiment

As shown in FIG. 7, the tensioner lifter 25b according to the third embodiment includes a washer 80 mounted on the outer periphery of the medium-diameter shaft 43 and received by the spring 46 from the axial direction. The washer 80 is molded from, for example, a metal material.

A collar member 81 is mounted on the outer periphery of the propulsion body 28 between the guide 51 and the washer 80 in the axial direction. The collar member 81 is formed in a cylindrical shape surrounding the propulsion body 28, and is sandwiched between the guide 51 and the washer 80 in the axial direction. The color member 81 is molded from, for example, a resin material or a metal material.

A string-wound spring (elastic member) 82 is arranged between the guide 51 and the second stepped surface 44 in the axial direction inside the collar member 81. The string winding spring 82 is sandwiched between the guide 51 and the second step surface 44 in a compressed state. The string winding spring 82 is continuous from the equal diameter body 82a having a constant winding diameter around the propulsion body 28 and the equal diameter body 82a, and is a second step surface between the propulsion body 28 and the second step surface 44 in the axial direction. It has a reduced diameter body 82b having a diameter that gradually shrinks toward 44. The string winding spring 82 is received by the second step surface 44 at the tip of the reduced diameter body 82b. Here, the large-diameter shaft 41 of the drive shaft 38 extends outward from the virtual cylindrical surface 84 that is coaxial with the axis 27 and is inscribed in the action point 83 of the string-wound spring 82 with respect to the second step surface 44. Further, the large-diameter shaft 41 extends outward from the virtual cylindrical surface 85 that is coaxial with the axis 27 and is inscribed by the string-wound spring 82. Other configurations are the same as those of the tensioner lifter 25 described above.

In the tensioner lifter 25b according to the present embodiment, since the string-wound spring 82 is directly pressed against the drive shaft 38, the number of parts is reduced as compared with the case where another member is interposed between the string-wound spring 82 and the drive shaft 38. Will be done. As the number of parts is reduced, the number of connected parts between parts is reduced, so that the risk of malfunction is reduced.

Fourth Embodiment

As shown in FIG. 8, the tensioner lifter 25c according to the fourth embodiment includes a collar member 91 mounted on the propulsion body 28 between the guide 51 and the thrust member 26a. The collar member 91 is formed in a cylindrical shape surrounding the propulsion body 28, and has one end 91a located on the thrust member 26a side of the propulsion body 28 in the axial direction. A flange 92 extending radially outward is formed at one end 91a of the collar member 91. A cylindrical positioning piece 93 protruding toward the thrust member 26a is formed on the outer periphery of the flange 92. The color member 91 is molded from, for example, a resin material or a metal material.

A disc spring (elastic member) 94 is sandwiched between the flange 92 of the collar member 91 and the second stepped surface 44 of the drive shaft 38 in the axial direction. Since the other end 91b of the collar member 91 is restrained by the guide 51, the disc spring 94 exerts an elastic force that applies a pressing force to the second stepped surface 44 toward the thrust member 26a in the axial direction. The disc spring 94 is fitted inside the positioning piece 93. The positioning piece 93 regulates the displacement of the disc spring 94 in the radial direction. Here, the large-diameter shaft 41 of the drive shaft 38 extends outward from the virtual cylindrical surface 96 that is coaxial with the axis 27 and is inscribed in the action point 95 of the disc spring 94 with respect to the second step surface 44. Further, the large-diameter shaft 41 extends outward from the virtual cylindrical surface 97 that is coaxial with the axis 27 and is inscribed by the disc spring 94. Other configurations are the same as those of the tensioner lifter 25 described above.

In the tensioner lifter 25c according to the present embodiment, since the disc spring 94 is directly pressed against the drive shaft 38, the number of parts is reduced as compared with the case where another member is interposed between the disc spring 94 and the drive shaft 38. Will be done. As the number of parts is reduced, the number of connected parts between parts is reduced, so that the risk of malfunction is reduced. Moreover, since the disc spring 94 is arranged between the collar member 91 and the drive shaft 38, the collar member 91 realizes shortening of the elastic member that exerts the pressing force of the drive shaft 38 in the axial direction, and also realizes shortening of the elastic member. Belleville spring 94 will be used instead of the long string-wound spring. Therefore, the behavior of the elastic member is stabilized. Since the collar member 91 is partially replaced with the elastic member, it is possible to reduce the use of the relatively expensive elastic member and reduce the manufacturing cost.

Fifth Embodiment

As shown in FIG. 9, the tensioner lifter 25d according to the fifth embodiment includes a friction member 101 that is received by the second step surface 44 from the axial direction. The friction member 101 is formed of an annular flat plate surrounding the shaft body 36. The friction member 101 is formed from, for example, a metal material. The friction member 101 is pressed against the second stepped surface 44 in the axial direction.

A collar member 102 is mounted on the outer periphery of the propulsion body 28 between the guide 51 and the friction member 101 in the axial direction. The collar member 102 is formed in a cylindrical shape surrounding the propulsion body 28, and has one end 102a located on the friction member 101 side of the propulsion body 28 in the axial direction. The color member 102 is formed from, for example, a resin material or a metal material. The propulsion body 28 inscribes in the collar member 102 and restrains the displacement of the collar member 102 in the radial direction. The collar member 102 may come into contact with the friction member 101 or the guide 51 at least at one of the one end 102a and the other end 102b.

A string-wound spring (elastic member) 103 is mounted on the outer circumference of the collar member 102. A string-wound spring (elastic member) 103 is sandwiched between the guide 51 and the friction member 101 in the axial direction. The string-wound spring 103 exerts an elastic force that applies a pressing force to the friction member 101 toward the thrust member 26a in the axial direction. The string-wound spring 103 is received by the friction member 101 so as to be relatively rotatable. Here, the large-diameter shaft 41 of the drive shaft 38 extends outward from the virtual cylindrical surface 105 that is coaxial with the axis 27 and is inscribed in the point of action 104 of the string-wound spring 103 with respect to the friction member 101. Further, the large-diameter shaft 41 extends outward from the virtual cylindrical surface 106 which is coaxial with the axis 27 and is circumscribed by the string winding spring 103. Other configurations are the same as those of the tensioner lifter 25 described above.

By the action of the mainspring 46, a driving force is applied to the drive shaft 38 around the axis 27. When the drive shaft 38 rotates, a propulsive force is applied to the propulsion body 28 according to the engagement of the male screw 37 and the female screw 48. At this time, the friction member 101 applies a resistance force to the rotation of the drive shaft 38 around the axis 27 according to the friction torque with the drive shaft 38. Similarly, the large-diameter shaft 41 imparts resistance to the rotation of the drive shaft 38 around the axis 27 according to the friction torque with the cup washer 45. In this way, the rotation of the drive shaft 38 is appropriately restrained. Therefore, the propulsive force of the propulsion body 28 is stabilized. Since the drive shaft 38 is received by the thrust member 26a by the large diameter shaft 41 having a diameter larger than that of the relay shaft 43 that spreads outward from the action point 104 of the string winding spring 103 and receives the mainspring 46, the drive shaft 38 is received by the thrust member 26a with respect to the thrust member 26a. The drive shaft 38 can be stably supported. Friction torque can be satisfactorily generated between the thrust member 26a and the large-diameter shaft 41.

Claims (9)

A drive shaft (38) having a male screw (37) rotatably supported around the shaft line (27) and engraved on the shaft body (36).
A thrust member (26a) that supports the shaft end of the drive shaft (38) in the thrust direction while restraining the displacement of the drive shaft (38) in the radial direction.
A propulsion body (28) having a female screw (48) that is restrained relative to the thrust member (26a) around the axis (27) and meshes with the male screw (37) on the inner surface.
An elastic force that drives the drive shaft (38) is generated around the axis (27), and the propulsion moves away from the thrust member (26a) according to the engagement of the male screw (37) and the female screw (48). A spring (46) that gives propulsion to the body (28),
A friction member (55; 71) that is pressed against the drive shaft (38) in the direction of the axis (27) and generates a frictional force with the drive shaft (38) around the axis (27).
A tensioner lifter (25; 25a; 25d) comprising an elastic member (58; 75; 103) that biases the friction member (55; 71; 101) toward the thrust member (26a) in the axial direction (27). ),
A virtual end of the drive shaft (38) is coaxial with the axis (27) and inscribed in the point of action of the elastic member (58; 75; 103) with respect to the friction member (55; 71; 101). A tensioner lifter characterized in that a large-diameter shaft (41) that extends outward from the cylindrical surface (62; 78; 105) and is received by the thrust member (26a) is formed. A drive shaft (38) having a male screw (37) rotatably supported around the shaft line (27) and engraved on the shaft body (36).
A thrust member (26a) that supports the shaft end of the drive shaft (38) in the thrust direction while restraining the displacement of the drive shaft (38) in the radial direction.
A propulsion body (28) having a female screw (48) that is restrained relative to the thrust member (26a) around the axis (27) and meshes with the male screw (37) on the inner surface.
An elastic force that drives the drive shaft (38) is generated around the axis (27), and the propulsion moves away from the thrust member (26a) according to the engagement of the male screw (37) and the female screw (48). A spring (46) that gives propulsion to the body (28),
With a friction member (55; 71; 101) that is pressed against the drive shaft (38) in the direction of the axis (27) and generates a frictional force with the drive shaft (38) around the axis (27). ,
A tensioner lifter (25; 25a; 25d) comprising an elastic member (58; 75; 103) that biases the friction member (55; 71; 101) toward the thrust member (26a) in the axial direction (27). ),
The drive shaft (38) has a large-diameter shaft (41) that is accepted by the recess (39) formed in the thrust member (26a), and is coaxial with the axis (27) and has a smaller diameter than the large-diameter shaft (41). Medium-diameter shaft (43) formed of the cylindrical body of the above, coupled to the large-diameter shaft (41) in the axial direction (27), and forming a first stepped surface (42) with the large-diameter shaft (41). ) And a tensioner lifter. The tensioner lifter according to claim 2, wherein the male screw (37) is formed to have a smaller diameter than the large diameter shaft (41). In the tensioner lifter according to any one of claims 1 to 3, the elastic member (58; 75; 103) is provided so as to be rotatable relative to the friction member (55; 71; 101). Tensioner lifter. One end of the tensioner lifter according to any one of claims 1 to 4, which surrounds the propulsion body (28) and is located on the friction member (55; 71) side of the propulsion body (28) in the axial direction. A collar member (56; 72) having (56a; 72a) is provided, and the elastic member (58; 75) has the collar on the friction member (55; 71) side of the propulsion body (28) in the axial direction. A tensioner lifter characterized in that it is sandwiched between the one end (56a; 72a) of the member (56; 72) and the friction member (55; 71). In the tensioner lifter according to claim 5, the boss (59; 76) that restricts the displacement of the elastic member (58; 75) in the radial direction to the friction member (55; 71) or the collar member (56; 72). ) Is formed in the tensioner lifter. A drive shaft (38) having a male screw (37) rotatably supported around the shaft line (27) and engraved on the shaft body (36).
A thrust member (26a) that supports the shaft end of the drive shaft (38) in the thrust direction while restraining the displacement of the drive shaft (38) in the radial direction.
A propulsion body (28) having a female screw (48) that is restrained relative to the thrust member (26a) around the axis (27) and meshes with the male screw (37) on the inner surface.
An elastic force that drives the drive shaft (38) is generated around the axis (27), and the propulsion moves away from the thrust member (26a) according to the engagement of the male screw (37) and the female screw (48). A spring (46) that gives propulsion to the body (28),
A friction member (55; 71) that is pressed against the drive shaft (38) in the direction of the axis (27) and generates a frictional force with the drive shaft (38) around the axis (27).
In a tensioner lifter (25; 25a) comprising an elastic member (58; 75) that biases the friction member (55; 71) toward the thrust member (26a) in the axial direction (27).
A collar member (56; 72) having one end (56a; 72a) located on the friction member (55; 71) side of the propulsion body (28) in the axial direction around the propulsion body (28) is provided. ,
The elastic member (58; 75) is the one end (56a; 72a) of the collar member (56; 72) on the friction member (55; 71) side of the propulsion body (28) in the axial direction. A tensioner lifter characterized by being sandwiched between a friction member (55; 71). A drive shaft (38) having a male screw (37) rotatably supported around the shaft line (27) and engraved on the shaft body (36).
A thrust member (26a) that supports the shaft end of the drive shaft (38) in the thrust direction while restraining the displacement of the drive shaft (38) in the radial direction.
A propulsion body (28) having a female screw (48) that is restrained relative to the thrust member (26a) around the axis (27) and meshes with the male screw (37) on the inner surface.
An elastic force that drives the drive shaft (38) is generated around the axis (27), and the propulsion moves away from the thrust member (26a) according to the engagement of the male screw (37) and the female screw (48). In a tensioner lifter (25b; 25c) with a spring (46) that imparts propulsion to the body (28).
It is characterized by comprising an elastic member (82; 94) that is pressed against the drive shaft (38) in the axial direction and applies a pressing force to the drive shaft (38) toward the thrust member (26a). Tensioner lifter. The tensioner lifter according to claim 7 is provided with a collar member (91) that surrounds the propulsion body (28) and is constrained so as to be non-displaceable in a direction away from the thrust member (26a). A tensioner lifter, characterized in that the elastic member (94) is arranged between the drive shaft (38) and the drive shaft (38).

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