WO2021187482A1

WO2021187482A1 - Auxiliary belt auto tensioner and auxiliary drive system

Info

Publication number: WO2021187482A1
Application number: PCT/JP2021/010609
Authority: WO
Inventors: 唯久田中; 洋生森本
Original assignee: Ntn株式会社
Priority date: 2020-03-18
Filing date: 2021-03-16
Publication date: 2021-09-23

Abstract

This auxiliary belt auto tensioner has a first pulley arm (8a) supporting a first idler pulley (7a), a second pulley arm (8b) supporting a second idler pulley (7b), a swing arm (10) swingably supported around a swing support shaft (9), a first spring (12a) that biases the first pulley arm (8a), a second spring (12b) that biases the second pulley arm (8b), and a swing-damping mechanism (32) or a swing-resistance-imparting mechanism (60).

Description

Auxiliary belt auto tensioner and auxiliary drive system

The present invention mainly relates to an auto tensioner for an auxiliary belt used for maintaining tension of a belt for driving an auxiliary machine of an automobile engine, and an auxiliary drive system using the auto tensioner for the auxiliary belt.

In recent years, an increasing number of mild hybrid systems aim to improve fuel efficiency by driving a generator (generator), which is an auxiliary machine of an automobile engine, as a starter (electric motor) when the vehicle starts or accelerates. The starter generator (motor / generator) used in this mild hybrid system is generally called a BSG (Belt Starter Generator).

In automobiles equipped with a mild hybrid system, an auxiliary belt (hereinafter simply referred to as "belt") is wrapped between the starter generator pulley attached to the rotating shaft of the starter generator and the crank pulley attached to the crankshaft. It has a belt transmission device.

This belt transmission device has a feature that the tension side and the slack side of the belt are switched between normal operation and drive of the starter generator. That is, during normal operation in which the starter generator operates as a generator, the crank pulley drives the starter generator pulley via the belt, so that the part of the belt traveling from the starter generator pulley toward the crank pulley becomes the tension side, and the crank. The part of the belt that runs from the pulley to the starter generator pulley is on the slack side. On the other hand, when the starter generator is driven as an electric motor, the starter generator pulley drives the crank pulley via the belt, so that the part of the belt running from the crank pulley to the starter generator pulley becomes the tension side. The part of the belt that runs from the starter generator pulley to the crank pulley is on the slack side.

As described above, the belt transmission device using the starter generator has a feature that the tension side and the slack side of the belt are switched between the normal operation and the drive of the starter generator.

As an auto tensioner for maintaining the tension of the belt of such a belt transmission device, a first idler pulley provided in contact with a portion of the belt traveling from the crank pulley to the starter generator pulley, and a crank pulley from the starter generator pulley to the crank pulley. A second idler pulley provided in contact with a portion of the belt traveling toward, a first swing arm that supports the first idler pulley, and a second swing that supports the second idler pulley. Those having an arm are known (Patent Documents 1 to 3).

The first swing arm and the second swing arm are supported so as to be swingable around a common swing support shaft. Further, the first swing arm and the second swing arm are urged by a spring in a direction in which the first idler pulley and the second idler pulley are brought close to each other.

In this auto tensioner, when the tension side and the slack side of the belt are switched, the first swing arm and the second swing arm swing according to the tension fluctuation of the belt. At this time, of the first idler pulley and the second idler pulley, the other idler pulley is attached to the belt by utilizing the force that the idler pulley that comes into contact with the portion switched from the slack side to the tension side is pushed back from the belt. Since it is pushed in, it is possible to quickly absorb the slack of the belt in the portion where the tension side is switched to the slack side.

Japanese Patent No. 4133320 Japanese Patent No. 4657200 Japanese Patent No. 5634685

Conventional auto tensioners such as Patent Documents 1 to 3 have both a rapid operation of absorbing the slack of the belt and an effective absorption of the vibration of the belt when the belt resonates. Was difficult.

That is, in the auto tensioner of Patent Document 1, the first swing arm that supports the first idler pulley and the second swing arm that supports the second idler pulley have a common swing support shaft. A spring that is swingably supported and urges both arms in a direction that narrows the angle formed by both arms between the first swing arm and the second swing arm, and the angle formed by both arms changes. A damping mechanism that sometimes generates a damper force is provided.

In the auto tensioner of Patent Document 1, in order to speed up the operation of absorbing the slack of the belt, it is necessary to set the damper force of the damping mechanism to be small. However, if the damper force is set to be small, when the belt resonates. It becomes difficult to effectively absorb the vibration of the belt. On the other hand, if the damper force of the damping mechanism is set large, it is possible to effectively absorb the vibration of the belt, but the operation of absorbing the slack of the belt becomes slow, and slip occurs between the belt and the starter generator pulley. There is a risk. In the auto tensioners of

Patent Documents

2 and 3, a damping mechanism is not provided in the first place.

The problem to be solved by the present invention is that the operation of absorbing the slack of the auxiliary belt can be performed quickly, and the vibration of the auxiliary belt is effectively absorbed when the auxiliary belt resonates. Is to provide an auto tensioner for auxiliary belts that can be used.

In order to solve the above problems, the present invention provides an auto tensioner for an auxiliary belt having the following configuration.
The first and second idler pulleys that come into contact with the auxiliary belt,
A first pulley arm that supports the first idler pulley and
A second pulley arm that supports the second idler pulley,
It has a first joint portion to which the first pulley arm is rotatably connected and a second joint portion to which the second pulley arm is rotatably connected, and the first joint portion and the said. A swing arm that is swingably supported around a swing support shaft arranged between the second joints,
A first spring that urges the first pulley arm in a direction in which the first idler pulley approaches the second idler pulley.
A second spring that urges the second pulley arm in a direction in which the second idler pulley approaches the first idler pulley.
A swing damping mechanism that generates a damper force in the direction opposite to the swing direction when the swing arm swings around the swing support shaft, or the swing arm is centered on the swing support shaft. A swing resistance applying mechanism that generates an elastic force in the direction opposite to the swing direction when swinging
Auxiliary belt for auto tensioner.

In this way, when a slack occurs in the portion of the auxiliary belt with which the first idler pulley comes into contact, the first pulley arm rotates with respect to the swing arm by the force of the first spring, so that the first pulley arm becomes the first. The idler pulley 1 moves in the direction approaching the second idler pulley, and the slack of the auxiliary belt can be quickly absorbed. Similarly, when a slack occurs in the portion of the auxiliary belt with which the second idler pulley comes into contact, the second pulley arm rotates with respect to the swing arm by the force of the second spring, so that the second pulley arm is seconded. The idler pulley moves in the direction approaching the first idler pulley, and it is possible to quickly absorb the slack of the auxiliary belt. When the auxiliary belt resonates, the swing arm swings around the swing support shaft, and at this time, a force opposite to the swing direction swings due to the swing damping mechanism or the swing resistance applying mechanism. Since it is applied to the arm, it is possible to absorb the vibration of the auxiliary belt. As described above, in the auxiliary belt auto tensioner, the forces of the first and second pulley arms urged by the first and second springs and the swing damping mechanism or the swing resistance applying mechanism are applied. Since the arm is separate from the swing arm, the operation of absorbing the slack of the auxiliary belt can be performed quickly, and the vibration of the auxiliary belt can be effectively absorbed when the auxiliary belt resonates. Is possible.

It is preferable that the swing arm is formed with a support shaft insertion hole into which the swing support shaft is inserted, and the swing damping mechanism or the swing resistance imparting mechanism is incorporated into the support shaft insertion hole.

In this way, the swing damping mechanism or the swing resistance applying mechanism is built in the swing support shaft portion of the swing arm. Therefore, when the auxiliary belt auto tensioner is attached, the swing damping mechanism is installed. It is not necessary to separately attach a mechanism or a swing resistance applying mechanism, and it is easy to attach an auto tensioner for an auxiliary belt.

The swing damping mechanism includes a cam member that is prevented from rotating around the swing support shaft, and a shoe member that is provided in the support shaft insertion hole and is stopped from rotating by the swing arm. As the member and the shoe member, those having a structure in which they are in frictional contact with each other so as to generate the damper force can be adopted.

By doing so, the swing damping mechanism can be suppressed compactly, so that the auto tensioner for the auxiliary belt can be miniaturized.

As the shoe member, an arc-shaped member provided so as to be movable in the radial direction outside the cam member is adopted, and the shoe member is an elastic member that urges the shoe member toward the cam member. Can be adopted in the configuration in which is attached.

In this way, the shoe member can move in the radial direction by contact with the cam member, and the shoe member is urged toward the cam member by the elastic member, so that the shoe member is between the cam member and the shoe member. The contact surface pressure becomes stable, and the magnitude of the damper force due to the frictional resistance between the cam member and the shoe member also becomes stable.

Further, as the shoe member, a metal leaf spring that is arranged so as to face the radial outer side of the cam member and can be deformed in the radial direction by contact with the cam member can be adopted.

In this way, since the shoe member is a leaf spring that can be deformed in the radial direction by contact with the cam member, the contact surface pressure between the cam member and the shoe member becomes stable, and the frictional resistance between the cam member and the shoe member becomes stable. The magnitude of the damper force is also stable. Further, since the shoe member is a metal leaf spring, the shoe member has excellent wear resistance.

The cam member is formed with a convex curved cam outer peripheral surface that projects outward in the radial direction.
The shoe member has an inner peripheral surface of the shoe that is in frictional contact with the outer peripheral surface of the cam.
When the shoe member rotates relative to the cam member due to the swing of the swing arm, the shoe inner peripheral surface comes into contact with the cam outer peripheral surface as the rotation angle increases. A structure having a shape inclined with respect to the circumferential direction can be adopted so that the surface pressure gradually increases.

In this way, as the swing angle of the swing arm increases, the contact surface pressure of the shoe inner peripheral surface with respect to the cam outer peripheral surface gradually increases. Therefore, when the auxiliary belt resonates, the vibration of the auxiliary belt can be reliably suppressed.

When fixing the swing support shaft to the fixing member, it is preferable to further provide a positioning washer that positions the fixing angle of the cam member with respect to the fixing member to a predetermined angle.

In this way, it is possible to accurately manage the fixing angle of the cam member with respect to the fixing member.

As the swing resistance imparting mechanism, one having a torsion coil spring having one end stopped by the swing support shaft and the other end stopped by the swing arm can be adopted.

In this way, the force in the direction opposite to the swing direction generated when the swing arm swings is due to the elastic force of the torsion coil spring, so a swing damping mechanism that generates a damper force due to frictional resistance is provided. Compared to when it is used, it is less likely to wear and can exhibit stable performance over a long period of time.

A first rotation stopper that receives the first pulley arm and regulates the rotation angle of the first pulley arm, and a second rotation that receives the second pulley arm and regulates the rotation angle of the second pulley arm. It is preferable to further provide a moving stopper.

In this way, the rotation angles of the first and second pulley arms are regulated by the first and second rotation stoppers, respectively, so that the vibration of the auxiliary belt is ensured when the auxiliary belt resonates. It is possible to suppress to.

A first buffer member that absorbs the impact when the first rotation stopper receives the first pulley arm, and
It is preferable to further provide a second cushioning member that absorbs an impact when the second rotation stopper receives the second pulley arm.

In this way, when the first and second rotation stoppers receive the first and second pulley arms, the impact is absorbed by the first and second cushioning members, so that when the auxiliary belt resonates. In addition, it is possible to suppress the generation of abnormal noise (continuous collision noise) from the first and second rotation stoppers.

The first idler pulley is composed of an annular first pulley body having an outer peripheral surface in contact with the accessory belt and a first rolling bearing fitted in the inner circumference of the first pulley body. ,
The second idler pulley is composed of an annular second pulley body having an outer peripheral surface in contact with the accessory belt and a second rolling bearing fitted in the inner circumference of the second pulley body. case,
The first pulley arm includes a pair of split shafts fitted into the first rolling bearing from both sides in the axial direction, a pair of first steel plates supporting both ends of the pair of split shafts in the axial direction, and the pair. It is composed of a dividing shaft and a coupling pin that penetrates and joins the pair of first steel plates.
The second pulley arm includes a pair of split shafts fitted into the second rolling bearing from both sides in the axial direction, a pair of second steel plates supporting both ends of the pair of split shafts in the axial direction, and the pair. It is preferably composed of a dividing shaft and a coupling pin that penetrates and joins the pair of second steel plates.

In this way, the first pulley arm and the second pulley arm can be manufactured at low cost and with high accuracy.

Further, the present invention provides an auxiliary machine drive system using the above-mentioned auxiliary machine belt auto tensioner having the following configuration.
The starter generator pulley attached to the rotating shaft of the starter generator,
With the crank pulley attached to the crankshaft,
The auxiliary belt wound between the starter generator pulley and the crank pulley,
It has the above-mentioned auto tensioner for the auxiliary belt that applies tension to the auxiliary belt, and
The first idler pulley is provided in contact with a portion of the auxiliary belt that travels from the crank pulley toward the starter generator pulley.
The second idler pulley is an auxiliary machine drive system provided in contact with a portion of the auxiliary machine belt that travels from the starter generator pulley toward the crank pulley.

In this auxiliary machine drive system, it is preferable that the auxiliary machine belt auto tensioner is arranged so that the center of the swing support shaft is radially outside the outer circumference of the starter generator pulley.

In this way, the lengths of the first pulley arm and the second pulley arm can be secured, so that the followability of the first idler pulley and the second idler pulley to the slack of the auxiliary belt can be improved. It becomes.

In the auxiliary belt auto tensioner of the present invention, when a slack occurs in the auxiliary belt portion that the first idler pulley contacts, the first pulley arm rotates with respect to the swing arm by the force of the first spring. By moving, the first idler pulley moves in the direction approaching the second idler pulley, and it is possible to quickly absorb the slack of the auxiliary belt. Similarly, when a slack occurs in the portion of the auxiliary belt with which the second idler pulley comes into contact, the second pulley arm rotates with respect to the swing arm by the force of the second spring, so that the second pulley arm is seconded. The idler pulley moves in the direction approaching the first idler pulley, and it is possible to quickly absorb the slack of the auxiliary belt. When the auxiliary belt resonates, the swing arm swings around the swing support shaft, and at this time, a force opposite to the swing direction swings due to the swing damping mechanism or the swing resistance applying mechanism. Since it is applied to the arm, it is possible to absorb the vibration of the auxiliary belt. As described above, in the auxiliary belt auto tensioner, the forces of the first and second pulley arms urged by the first and second springs and the swing damping mechanism or the swing resistance applying mechanism are applied. Since the arm is separate from the swing arm, the operation of absorbing the slack of the auxiliary belt can be performed quickly, and the vibration of the auxiliary belt can be effectively absorbed when the auxiliary belt resonates. Is possible.

Front view showing an example of an auxiliary machine drive system using the auxiliary machine belt auto tensioner of the first embodiment of the present invention. Enlarged view of the vicinity of the swing arm of the auto tensioner for the auxiliary belt shown in FIG. Sectional view taken along the line III-III of FIG. Sectional view taken along line IV-IV of FIG. Cross-sectional view taken along the line VV of FIG. A cross-sectional view showing a state in which the swing arm shown in FIG. 5 swings. Right side view of the auto tensioner for the auxiliary belt shown in FIG. Sectional view taken along the line VIII-VIII of FIG. Sectional view taken along line IX-IX in FIG. The figure which shows typically the auxiliary drive system when the engine is stopped. The figure which shows typically the auxiliary machine drive system at the time of normal operation The figure which shows typically the auxiliary machine drive system at the time of starting a starter generator drive The figure which shows typically the auxiliary drive system when the belt is stretched by aged deterioration. An exploded perspective view of the swing damping mechanism shown in FIG. An exploded perspective view of the second joint shown in FIG. The figure which shows the vicinity of the swing support shaft of the auxiliary belt auto tensioner of 2nd Embodiment of this invention corresponding to FIG. Sectional view taken along the line XIV-XIV of FIG. A cross-sectional view showing a state in which the swing arm shown in FIG. 14 swings. The figure which shows the vicinity of the swing support shaft of the auto tensioner for an auxiliary belt of 3rd Embodiment of this invention corresponding to FIG. Sectional view taken along the line XVII-XVII of FIG. A cross-sectional view showing a state in which the swing arm shown in FIG. 17 swings. The figure which shows the vicinity of the swing support shaft of the auto tensioner for an auxiliary belt of 4th Embodiment of this invention corresponding to FIG. Sectional view taken along the line XX-XX of FIG. A cross-sectional view showing a state in which the swing arm shown in FIG. 20 swings.

FIG. 1 shows an example of an auxiliary machine drive system using the auxiliary machine belt auto tensioner 1 (hereinafter, simply referred to as “auto tensioner 1”) according to the first embodiment of the present invention. This auxiliary drive system was wound between the starter generator pulley 3 attached to the rotating shaft 2 of the starter generator, the crank pulley 5 attached to the crankshaft 4, and the starter generator pulley 3 and the crank pulley 5. It has an auxiliary belt 6 (hereinafter, simply referred to as "belt 6") and an auto tensioner 1 that keeps the tension of the belt 6 within an appropriate range.

The auto tensioner 1 includes a first idler pulley 7a, a second idler pulley 7b, a first pulley arm 8a that supports the first idler pulley 7a, and a second pulley arm that supports the second idler pulley 7b. It has 8b and a swing arm 10 that is swingably supported around a swing support shaft 9.

The first idler pulley 7a is in contact with the outer peripheral surface of the portion of the belt 6 traveling from the crank pulley 5 toward the starter generator pulley 3. Further, the second idler pulley 7b is in contact with the outer peripheral surface of the portion of the belt 6 traveling from the starter generator pulley 3 toward the crank pulley 5. Here, the first idler pulley 7a and the second idler pulley 7b have a span adjacent to the upstream side of the starter generator pulley 3 of the belt 6 and a span adjacent to the downstream side of the starter generator pulley 3 of the belt 6. It is arranged with a span to be sandwiched between them.

The swing arm 10 is formed in a C shape that faces a part of the outer circumference of the starter generator pulley 3 (in the figure, a portion of the outer circumference of the starter generator pulley 3 corresponding to a central angle of 90 degrees or more) in the radial direction. .. The shape of the swing arm 10 is symmetrical with respect to the swing support shaft 9. The center of the swing support shaft 9 is arranged radially outside the outer circumference of the starter generator pulley 3 and outside the region surrounded by the endless belt 6.

The first pulley arm 8a is rotatably connected to a first joint portion 11a provided at one end of the C-shaped swing arm 10 in the circumferential direction. The second pulley arm 8b is rotatably connected to a second joint portion 11b provided at the other end of the C-shaped swing arm 10 in the circumferential direction.

The first pulley arm 8a and the member attached thereto have the same symmetrical configuration as the second pulley arm 8b and the member attached thereto. Therefore, hereinafter, only the configuration of one side of the first pulley arm 8a and the second pulley arm 8b will be described, and for the configuration of the other side, the same code or a code in which the letters a and b at the end are replaced is used. The description will be omitted.

A first spring 12a for urging the first pulley arm 8a in the direction in which the first idler pulley 7a approaches the second idler pulley 7b is incorporated between the first pulley arm 8a and the swing arm 10. There is. Between the first pulley arm 8a and the swing arm 10, a first rotation stopper 13a that receives the first pulley arm 8a and regulates the rotation angle of the first pulley arm 8a is provided. The first rotation stopper 13a is a portion that regulates the rotation angle of the first idler pulley 7a in the direction away from the second idler pulley 7b, and the first idler pulley 7a approaches the second idler pulley 7b. It is composed of a part that regulates the rotation angle in the direction.

As shown in FIG. 2, the first spring 12a is supported between the swing arm 10 and the first pulley arm 8a so that one end is supported by the swing arm 10 and the other end presses the first pulley arm 8a. It is built into. As the first spring 12a, a leaf spring or a torsion coil spring can be adopted, but here, a compression coil spring is adopted. The swing arm 10 is formed with a spring accommodating hole 14 for accommodating the first spring 12a. A bottomed cylindrical slide cap 15 is slidably inserted into the spring accommodating hole 14. The protruding end of the slide cap 15 from the spring accommodating hole 14 is in contact with the contact pin 16 fixed to the first pulley arm 8a. The first spring 12a presses the first pulley arm 8a via the slide cap 15 and the contact pin 16.

Between the swing arm 10 and the first pulley arm 8a, a first cushioning member 17a is provided to absorb the impact when the first rotation stopper 13a receives the first pulley arm 8a. The first cushioning member 17a is made of rubber or elastomer and elastically compresses when the first rotating stopper 13a receives the first pulley arm 8a to absorb an impact.

As shown in FIGS. 8 and 12, the second joint portion 11b is composed of a joint pin 18 and a slide bearing 19. Both ends of the joint pin 18 are press-fitted into the pin holes 20 formed in the second pulley arm 8b. The slide bearing 19 is inserted into an axial through hole 21 formed in the swing arm 10, and the outer circumference of the joint pin 18 is in sliding contact with the inner circumference of the slide bearing 19.

As shown in FIG. 2, the swing support shaft 9 is arranged between the first joint portion 11a and the second joint portion 11b of the swing arm 10. In the figure, the swing support shaft 9 is arranged at the center position in the circumferential direction (center position in the longitudinal direction) of the C-shaped swing arm 10.

As shown in FIG. 3, the swing arm 10 is formed with a support shaft insertion hole 22 into which the swing support shaft 9 is inserted. The support shaft insertion hole 22 is formed so as to penetrate the swing arm 10 in the axial direction. In the embodiment, the swing support shaft 9 is a bolt with a head having a screw shaft portion 23 having a male screw formed on the outer periphery thereof and a head portion 24 provided at one end of the screw shaft portion 23. The screw shaft portion 23 is screwed into a fixing member 25 (a stationary member such as a housing of a starter generator). A washer 26, a sleeve 27, and a cam member 28 are fitted and provided on the outer periphery of the screw shaft portion 23 in this order from the side of the head 24 toward the side of the fixing member 25. The washer 26, the sleeve 27, and the cam member 28 are fixed to the fixing member 25 by the axial force received from the head 24.

The support shaft insertion hole 22 has a small diameter inner diameter portion 29 and a large diameter inner diameter portion 30 having an inner diameter larger than that of the small diameter inner diameter portion 29. The large-diameter inner diameter portion 30 is formed adjacent to the fixing member 25 with respect to the small-diameter inner diameter portion 29. A slide bearing 31 that rotatably supports the outer circumference of the sleeve 27 is fitted in the inner circumference of the small diameter inner diameter portion 29. Inside the large-diameter inner diameter portion 30, a swing damping mechanism 32 that generates a damper force in the direction opposite to the swing direction when the swing arm 10 swings around the swing support shaft 9 is incorporated. ing.

The swing damping mechanism 32 has a cam member 28 and a shoe member 33 that are in frictional contact with each other so as to generate a damper force in response to the swing of the swing arm 10. The cam member 28 is fixed by being pressed against the fixing member 25 by the axial force received from the head 24, and is stopped by the swing support shaft 9 by the fixing.

As shown in FIGS. 3 and 4, a circumferential positioning portion 34 (D-cut portion in the drawing) is formed on the outer periphery of the end portion of the cam member 28 on the side of the fixing member 25, and the circumferential positioning portion 34 is formed with the circumferential positioning portion 34. The positioning washer 35 is fitted. The positioning washer 35 is a member that positions the fixing angle of the cam member 28 with respect to the fixing member 25 to a predetermined angle when the swing support shaft 9 is fixed to the fixing member 25.

As shown in FIG. 4, the positioning washer 35 is provided with an engaging hole 37 that engages with the positioning protrusion 36 provided on the fixing member 25, and the engagement between the protrusion 36 and the engaging hole 37 causes the positioning washer 35 to engage. The angle of the positioning washer 35 with respect to the fixing member 25 is fixed, and further, the angle of the cam member 28 with respect to the positioning washer 35 is fixed by fitting the circumferential positioning portion 34 of the cam member 28 and the positioning washer 35, and as a result, the cam member 28 is fixed. The angle of the cam member 28 with respect to the member 25 is positioned. As shown in FIG. 3, the end opening on the side of the fixing member 25 of the large-diameter inner diameter portion 30 of the support shaft insertion hole 22 is closed by the annular cover 38. The cover 38 is sandwiched between the cam member 28 and the positioning washer 35. Instead of the cover 38, a seal member (for example, an O-ring incorporated between the swing arm 10 and the axially opposed surfaces of the positioning washer 35) can be used.

As shown in FIG. 5, the cam member 28 is inserted into the large-diameter inner diameter portion 30 of the support shaft insertion hole 22. The cam member 28 is formed with a convex curved cam outer peripheral surface 39 that projects outward in the radial direction (see FIG. 11). In the embodiment, a pair of cam outer peripheral surfaces 39 are formed in opposite directions with respect to the swing support shaft 9.

The shoe member 33 is composed of a pair of left and right arc-shaped shoe dividing bodies 40. A radial gap is provided between the outer circumference of each shoe split body 40 and the inner circumference of the large-diameter inner diameter portion 30, and each shoe split body 40 can move in the radial direction within the range of the radial gap. There is. An elastic member 41 that urges each shoe split 40 toward the cam member 28 is attached to the pair of left and right shoe splits 40. The elastic member 41 is a C-shaped circlip. The elastic member 41 presses each shoe split body 40 against the cam outer peripheral surface 39 of the cam member 28 by urging the pair of shoe split bodies 40 in a direction approaching each other. One of the pair of shoe splits 40 is provided with a pressing surface 42 that is pressed in the circumferential direction at one end of the elastic member 41 in the circumferential direction, and the other of the pair of shoe splits 40 is also an elastic member. A pressing surface 42 that is pressed in the circumferential direction at the other end of the circumferential direction of 41 is provided.

The shoe member 33 composed of the pair of shoe split bodies 40 is formed with a shoe inner peripheral surface 43 that is in frictional contact with the cam outer peripheral surface 39. The shoe inner peripheral surface 43 is an elliptical inner peripheral surface centered on the swing support shaft 9, and the cam member 28 is housed inside so that the major axis direction of the ellipse is the protruding direction of the cam outer peripheral surface 39. ing. The shoe inner peripheral surface 43 is always in contact with the cam outer peripheral surface 39 due to the urging force of the elastic member 41.

A detent projection 44 protruding inward in the radial direction is formed on the inner circumference of the large-diameter inner diameter portion 30 of the support shaft insertion hole 22. The detent projection 44 engages with the circumferential end of each arc-shaped shoe dividing body 40, and the shoe member 33 is detented by the swing arm 10 by this engagement.

Here, the shoe inner peripheral surface 43 (the elliptical inner peripheral surface in the embodiment) has a shape inclined with respect to the circumferential direction (that is, the direction along the perfect circle centered on the swing support shaft 9). There is. Therefore, as shown in FIG. 6, when the shoe member 33 rotates relative to the cam member 28 due to the swing of the swing arm 10, the shoe inner peripheral surface 43 with respect to the cam outer peripheral surface 39 increases as the rotation angle increases. The contact surface pressure of is gradually increased.

As shown in FIG. 5, when the swing arm 10 is in the neutral position (that is, the swing arm 10 is at the swing angle at which the contact surface pressure of the shoe inner peripheral surface 43 with respect to the cam outer peripheral surface 39 is the smallest). When), a gap is provided over the entire circumference between the outer circumference of the shoe member 33 and the inner circumference of the large-diameter inner diameter portion 30 of the support shaft insertion hole 22. As shown in FIG. 6, this gap gradually narrows as the shoe member 33 rotates relative to the cam member 28 due to the swing of the swing arm 10, and the swing angle α of the swing arm 10 has a predetermined size. When it reaches the limit, the shoe member 33 cannot rotate relative to the cam member 28 due to the increase in the surface pressure between the support shaft insertion hole 22 and the inner circumference of the large diameter inner diameter portion 30, and the shoe member 33 sways. The moving arm 10 is locked.

As shown in FIGS. 7 and 9, the second idler pulley 7b is fitted into the annular second pulley body 45b having an outer peripheral surface in contact with the belt 6 and the inner circumference of the second pulley body 45b. It is composed of a second rolling bearing 46b.

As shown in FIG. 9, the outer peripheral surface of the second pulley main body 45b is a cylindrical surface having a constant outer diameter along the axial direction. The second pulley body 45b is made of resin. The second rolling bearing 46b has a plurality of rolling elements 49 (balls in the figure) provided between the outer ring 47, the inner ring 48, and the outer ring 47 and the inner ring 48 at intervals in the circumferential direction. The outer ring 47 is fixed to the inner circumference of the second pulley main body 45b. The outer ring 47 can be fixed to the second pulley body 45b by insert molding. That is, by molding the second pulley body 45b with resin while the outer ring 47 is arranged in the molding die of the second pulley body 45b, a part of the outer ring 47 is formed on the inner circumference of the second pulley body 45b. In the embedded state, the outer ring 47 can be fixed to the second pulley main body 45b.

The second pulley arm 8b is a pair of split shafts 50 fitted from both sides in the axial direction into the inner ring 48 of the second rolling bearing 46b, and a pair of second steel plates supporting both ends in the axial direction of the pair of split shafts 50. It is composed of 51b, a pair of dividing shafts 50, and a coupling pin 52 that penetrates and joins a pair of second steel plates 51b.

Each dividing shaft 50 is made of resin or aluminum alloy. Each split shaft 50 has a fitting shaft portion 53 that fits on the inner circumference of the inner ring 48, and a shoulder portion 54 that abuts on the axial end surface of the inner ring 48. The shoulder portion 54 is a stepped portion whose diameter is increased from the axially outer end portion of the fitting shaft portion 53. Further, the split shaft 50 has a flange portion 55 having an outer diameter larger than the inner diameter of the outer ring 47. A labyrinth gap 56 is formed between the axially inner side surface of the flange portion 55 and the second pulley body 45b. A tightening allowance is set between the outer circumference of the fitting shaft portion 53 and the inner circumference of the inner ring 48. The outer circumference of the fitting shaft portion 53 and the inner circumference of the inner ring 48 can be fitted without a tightening allowance.

The pair of second steel plates 51b are arranged so as to face each other in the axial direction with the pair of dividing shafts 50 sandwiched between them. The flat axial inner surface of the second steel plate 51b is in surface contact with the flat axial outer end surface of the dividing shaft 50. The coupling pin 52 is inserted through the axial through hole 57 formed in the pair of second steel plates 51b and the axial through hole 58 formed in the pair of dividing shafts 50. A tightening allowance is set between the outer circumference of the coupling pin 52 and the inner circumference of the through hole 57 of the second steel plate 51b. Further, a tightening allowance is also set between the outer circumference of the coupling pin 52 and the inner circumference of the through hole 58 of the dividing shaft 50. Here, of the inner circumference of the through hole 58, the tightening allowance for the outer circumference of the coupling pin 52 is provided only on the portion outside the fitting shaft portion 53 in the axial direction. A gap is provided between the inner circumference of the fitting shaft portion 53 and the outer circumference of the coupling pin 52. The inner circumference of the through hole 58 and the outer circumference of the coupling pin 52 can be fitted without a tightening margin.

As shown in FIGS. 7 and 9, the pair of split shafts 50 that face each other in the axial direction with the second rolling bearing 46b in between have the same shape and the same dimensions, and the pair of split shafts 50 are in the axial direction. The pair of second steel plates 51b facing each other also have the same shape and dimensions. This makes it possible to standardize the parts and reduce the manufacturing cost of the second pulley arm 8b.

An example of using the above auto tensioner 1 will be described.

FIG. 10A shows an auxiliary drive system when the engine is stopped. Both the starter generator pulley 3 and the crank pulley 5 are stopped. The first idler pulley 7a is urged by the first spring 12a (see FIG. 1) in a direction approaching the second idler pulley 7b, and the second idler pulley 7b is urged by the second spring 12b (see FIG. 1). ) Is urged in the direction approaching the first idler pulley 7a, whereby tension is applied to the belt 6. At this time, the portion of the belt 6 that the first idler pulley 7a contacts (the portion of the belt 6 that travels from the crank pulley 5 toward the starter generator pulley 3 when the engine rotates. The traveling direction of the belt 6 is clockwise). The tension and the tension of the belt 6 portion (the portion of the belt 6 traveling from the starter generator pulley 3 toward the crank pulley 5 when the engine rotates) in contact with the second idler pulley 7b are in a balanced state.

FIG. 10B shows an auxiliary drive system during normal operation (that is, when the starter generator pulley 3 operates as a driven pulley). The crank pulley 5 drives the starter generator pulley 3 via the belt 6. The portion of the belt 6 traveling from the starter generator pulley 3 toward the crank pulley 5 is on the tension side, and the portion of the belt 6 traveling from the crank pulley 5 toward the starter generator pulley 3 is on the slack side. At this time, in the auto tensioner 1, the first pulley arm 8a rotates with respect to the swing arm 10 by the force of the first spring 12a (see FIG. 1), so that the first idler pulley 7a becomes the second idler. It moves in the direction approaching the pulley 7b and quickly absorbs the slack of the belt 6. On the other hand, the second pulley arm 8b is pushed back to the outside of the belt 6 by the tension of the belt 6. The swing arm 10 reaches a position where the elastic restoring force of the first spring 12a and the elastic restoring force of the second spring 12b are balanced while generating a damper force by the swing damping mechanism 32 (see FIGS. 5 and 6). Swing.

FIG. 10C shows an auxiliary drive system when the starter generator is driven (that is, when the starter generator pulley 3 operates as a drive pulley). For example, when the engine is started after idling stop or when the engine power is assisted by the starter generator. The starter generator pulley 3 drives the crank pulley 5 via the belt 6. The portion of the belt 6 traveling from the crank pulley 5 toward the starter generator pulley 3 is on the tension side, and the portion of the belt 6 traveling from the starter generator pulley 3 toward the crank pulley 5 is on the slack side. At this time, in the auto tensioner 1, the second pulley arm 8b rotates with respect to the swing arm 10 by the force of the second spring 12b (see FIG. 1), so that the second idler pulley 7b becomes the first idler. It moves in the direction approaching the pulley 7a and quickly absorbs the slack of the belt 6. On the other hand, the first pulley arm 8a is pushed back to the outside of the belt 6 by the tension of the belt 6. The swing arm 10 reaches a position where the elastic restoring force of the first spring 12a and the elastic restoring force of the second spring 12b are balanced while generating a damper force by the swing damping mechanism 32 (see FIGS. 5 and 6). Swing.

FIG. 10D shows an auxiliary drive system when the belt 6 is stretched due to aged deterioration. At this time, the first idler pulley 7a is moved in the direction approaching the second idler pulley 7b by the first spring 12a (see FIG. 1), and the second idler pulley 7b is moved by the second spring 12b (see FIG. 1). 1) moves toward the first idler pulley 7a, thereby absorbing the elongation of the belt 6 and keeping the tension of the belt 6 within an appropriate range. In the figure, both the starter generator pulley 3 and the crank pulley 5 are stopped.

In this auto tensioner 1, as shown in FIG. 10B, when a portion of the belt 6 traveling from the crank pulley 5 toward the starter generator pulley 3 is slackened, the first pulley arm 8a of the first pulley arm 8a of the first spring 12a By rotating with respect to the swing arm 10 by force, the first idler pulley 7a moves in a direction approaching the second idler pulley 7b, and the slack of the belt 6 can be quickly absorbed. Similarly, as shown in FIG. 10C, when the portion of the belt 6 traveling from the starter generator pulley 3 toward the crank pulley 5 is loosened, the second pulley arm 8b is shaken by the force of the second spring 12b. By rotating with respect to the moving arm 10, the second idler pulley 7b moves in a direction approaching the first idler pulley 7a, and the slack of the belt 6 can be quickly absorbed. In the state of FIGS. 10B and 10C, when the belt 6 resonates, the swing arm 10 swings around the swing support shaft 9, and at this time, the swing damping mechanism 32 reverses the swing direction. Since the damper force is generated, it is possible to absorb the vibration of the belt 6. As described above, in the auto tensioner 1, the first and

second pulley arms

8a and 8b urged by the first and

second springs

12a and 12b and the vibration damping mechanism 32 apply a damper force. Since the moving arm 10 is a separate arm, it is possible to quickly perform an operation of absorbing the slack of the belt 6, and it is possible to effectively absorb the vibration of the belt 6 when the belt 6 resonates. be.

Further, as shown in FIG. 1, in this auto tensioner 1, since the center of the swing support shaft 9 is arranged radially outside the outer circumference of the starter generator pulley 3, the first pulley arm 8a and the second pulley arm 8a and the second It is possible to secure the length of the pulley arm 8b. Therefore, the first idler pulley 7a and the second idler pulley 7b have high followability to the slack of the belt 6.

Further, as shown in FIG. 3, the auto tensioner 1 is provided with a swing damping mechanism 32 incorporated in a support shaft insertion hole 22 of the swing arm 10, and a portion of the swing support shaft 9 of the swing arm 10. Since the auto tensioner 1 is attached to the fixing member 25, it is not necessary to separately attach the swing damping mechanism 32. Therefore, the auto tensioner 1 can be easily attached.

Further, as shown in FIG. 5, the auto tensioner 1 has a configuration in which the cam member 28, which is prevented from rotating around the swing support shaft 9, and the shoe member 33 provided in the support shaft insertion hole 22 are brought into frictional contact with each other. Since the oscillating damping mechanism 32 is adopted, the oscillating damping mechanism 32 is compact. Therefore, the auto tensioner 1 can be miniaturized.

Further, as shown in FIG. 5, in the auto tensioner 1, the shoe member 33 can move in the radial direction by contact with the cam member 28, and the shoe member 33 is an elastic member 41 toward the cam member 28. Since it is urged, the contact surface pressure between the cam member 28 and the shoe member 33 is stable, and the magnitude of the damper force due to the frictional resistance between the cam member 28 and the shoe member 33 is also stable.

Further, as shown in FIG. 6, the auto tensioner 1 has a swing damping mechanism in which the contact surface pressure of the shoe inner peripheral surface 43 with respect to the cam outer peripheral surface 39 gradually increases as the swing angle of the swing arm 10 increases. Since 32 is adopted, it is possible to surely suppress the vibration of the belt 6 when the belt 6 resonates.

Further, as shown in FIG. 3, the auto tensioner 1 has a positioning washer 35 that positions the fixing angle of the cam member 28 with respect to the fixing member 25 to a predetermined angle when the swing support shaft 9 is fixed to the fixing member 25. Therefore, it is possible to accurately manage the fixing angle of the cam member 28 with respect to the fixing member 25.

Further, as shown in FIG. 1, in this auto tensioner 1, the rotation angles of the first and

second pulley arms

8a and 8b are regulated by the first and

second rotation stoppers

13a and 13b, respectively. When the belt 6 resonates, the vibration of the belt 6 can be reliably suppressed.

Further, as shown in FIG. 2, the auto tensioner 1 includes a first cushioning member 17a that absorbs an impact when the first rotation stopper 13a receives the first pulley arm 8a, and a second rotation stopper. Since the 13b has a second cushioning member 17b that absorbs an impact when receiving the second pulley arm 8b, when the belt 6 (see FIG. 1) resonates, the first and second rotating stoppers 13a, It is possible to suppress the generation of abnormal noise (continuous collision sound) from 13b.

Further, as shown in FIG. 9, the auto tensioner 1 has a pair of split shafts 50 fitted into the second rolling bearing 46b from both sides in the axial direction, and a pair of supporting both ends of the pair of split shafts 50 in the axial direction. The second pulley arm 8b is formed by the second steel plate 51b and the coupling pin 52 that penetrates and joins the pair of dividing shafts 50 and the pair of the second steel plates 51b. It is possible to manufacture with high accuracy at low cost. The same applies to the first pulley arm 8a.

13 to 15 show a second embodiment of the present invention. The second embodiment is different from the first embodiment only in the configuration of the shoe member 33 constituting the swing damping mechanism 32 and the presence / absence of the positioning washer 35, and the other configurations are the same. Therefore, the same reference numerals are given to the parts corresponding to the first embodiment, and the description thereof will be omitted.

As shown in FIG. 13, the circumferential positioning portion 34 (D-cut portion in the figure) formed on the outer periphery of the end portion of the cam member 28 on the side of the fixing member 25 is formed in the fixing member 25. The mounting angle of the cam member 28 with respect to the fixing member 25 is positioned at a predetermined angle by fitting to. Here, an example in which the circumferential positioning portion 34 of the cam member 28 is directly fitted to the fixing member 25 has been shown, but as in the first embodiment, the positioning washer between the cam member 28 and the fixing member 25. 35 (see FIGS. 3 and 4) may be interposed so that the circumferential positioning portion 34 of the cam member 28 is fitted to the positioning washer 35.

As shown in FIG. 14, the shoe member 33 is an arch-shaped leaf spring arranged so as to face the radial outer side of the cam member 28. A radial gap is provided between the outer circumference of the shoe member 33 and the inner circumference of the large-diameter inner diameter portion 30, and the shoe member 33 can be deformed in the radial direction within the range of the radial gap. A pair of shoe members 33 are provided corresponding to the pair of cam outer peripheral surfaces 39.

The shoe member 33 is formed with a shoe inner peripheral surface 43 that is in frictional contact with the cam outer peripheral surface 39. The shoe inner peripheral surface 43 is a concave curved inner peripheral surface along the convex curved cam outer peripheral surface 39. As shown in FIG. 14, the shoe inner peripheral surface 43 is in non-contact with the cam outer peripheral surface 39 when the swing arm 10 is in the neutral position, and as shown in FIG. 15, the swing arm 10 is from the neutral position. It is formed so as to come into contact with the outer peripheral surface 39 of the cam when it swings. The shoe inner peripheral surface 43 may be formed so as to be in contact with the cam outer peripheral surface 39 at all times.

On the inner circumference of the large-diameter inner diameter portion 30 of the support shaft insertion hole 22, two detent projections 44 protruding inward in the radial direction are formed at intervals in the circumferential direction. The detent projection 44 receives both ends of the shoe member 33 in the circumferential direction, thereby detenting each shoe member 33 to the swing arm 10. Further, both ends of the shoe member 33 in the circumferential direction are restricted from moving outward in the radial direction at the inner circumference of the large-diameter inner diameter portion 30.

Here, the shoe inner peripheral surface 43 has a shape inclined with respect to the circumferential direction (that is, the direction along the perfect circle centered on the swing support shaft 9). Therefore, as shown in FIG. 15, when the shoe member 33 rotates relative to the cam member 28 due to the swing of the swing arm 10, the shoe inner peripheral surface 43 with respect to the cam outer peripheral surface 39 increases as the rotation angle increases. The contact surface pressure of is gradually increased. Then, when the swing angle of the swing arm 10 reaches a predetermined size, the shoe member 33 cannot rotate relative to the cam member 28 any more, and the swing arm 10 is locked. It becomes.

When the auto tensioner 1 of the second embodiment is adopted, as in the first embodiment, the first and

second pulley arms

8a and 8b urged by the first and

second springs

12a and 12b and the swing damping Since the swing arm 10 to which the damper force is applied by the mechanism 32 is a separate arm, the operation of absorbing the slack of the belt 6 can be quickly performed, and the belt 6 vibrates when the belt 6 resonates. Can be effectively absorbed.

Further, in the auto tensioner 1 of the second embodiment, as shown in FIG. 15, since the shoe member 33 is a leaf spring that can be deformed in the radial direction by contact with the cam member 28, it is between the cam member 28 and the shoe member 33. The contact surface pressure is stable, and the frictional resistance between the cam member 28 and the shoe member 33 is also stable. Further, since the shoe member 33 is a metal leaf spring, the shoe member 33 has excellent wear resistance.

Further, as shown in FIGS. 14 and 15, the auto tensioner 1 of the second embodiment has an inner circumference of the shoe with respect to the outer peripheral surface 39 of the cam as the swing angle of the swing arm 10 increases, as shown in FIGS. 14 and 15. The contact surface pressure of the surface 43 gradually increases. Therefore, even when the tension fluctuation of the belt 6 caused by the rotation fluctuation of the crankshaft 4 shown in FIG. 1 is large, it is possible to effectively prevent the entire auto tensioner 1 including the swing arm 10 from swinging excessively. It is possible to do.

Further, in the auto tensioner 1 of the second embodiment, as in the first embodiment, the swing damping mechanism 32 is located between the outer circumference of the swing support shaft 9 and the inner circumference of the support shaft insertion hole 22 of the swing arm 10. The auto tensioner 1 is compact because it is housed in. Further, the work of attaching the auto tensioner 1 to the belt transmission device is also easy. Other effects are the same as those in the first embodiment.

16 to 18 show a third embodiment of the present invention. The third embodiment replaces the swing damping mechanism 32 of the second embodiment with the swing resistance applying mechanism 60, and the other configurations are the same as those of the second embodiment. Therefore, the same reference numerals are given to the parts corresponding to the second embodiment, and the description thereof will be omitted.

As shown in FIG. 16, the swing support shaft 9 is a bolt with a head having a screw shaft portion 23 having a male screw formed on the outer circumference and a head portion 24 provided at one end of the screw shaft portion 23. A washer 26 and a sleeve 27 are fitted and provided on the outer circumference of the screw shaft portion 23 in this order from the side of the head 24 toward the side of the fixing member 25. The washer 26 and the sleeve 27 are fixed to the fixing member 25 by the axial force received from the head 24.

The sleeve 27 is integrally provided at the end of the sleeve body 61 on the fixing member 25 side with the cylindrical sleeve body 61 that supports the inner circumference of the slide bearing 31 press-fitted into the inner circumference of the support shaft insertion hole 22. It has a sleeve end plate 62 and a circumferential positioning portion 34 extending from the sleeve end plate 62 toward the fixing member 25. An annular space for accommodating the torsion coil spring 63 is formed between the inner circumference of the sleeve body 61 and the outer circumference of the screw shaft portion 23. Further, a notch 64 penetrating in the radial direction is formed at an end portion of the sleeve body 61 opposite to the fixing member 25. The sleeve end plate 62 is fitted on the outer circumference of the screw shaft portion 23.

The swing resistance applying mechanism 60 has a torsion coil spring 63 that twists and deforms in response to the swing of the swing arm 10 when the swing arm 10 swings about a swing support shaft 9. This is a mechanism in which the coil spring 63 generates an elastic force in the direction opposite to the swing direction. A first arm portion 65 that is prevented from rotating by the swing arm 10 is formed at one end of the torsion coil spring 63, and a second arm that is prevented from rotating by the swing support shaft 9 at the other end of the torsion coil spring 63. The portion 66 is formed.

As shown in FIG. 17, the first arm portion 65 penetrates the notch 64 formed in the sleeve body 61 in the radial direction, and the portion protruding toward the outer diameter side through the notch 64 is inserted into the support shaft. It engages with an engaging recess 67 formed on the inner circumference of the hole 22, and one end of the torsion coil spring 63 is prevented from rotating by the swing arm 10 due to the engagement. The second arm portion 66 is engaged with the engagement hole 68 provided in the sleeve end plate 62, and the other end of the torsion coil spring 63 is stopped by the swing support shaft 9 by the engagement. ..

A play in the circumferential direction is provided between the inner surface of the engaging recess 67 and the first arm portion 65. Within this range of play, the torsion coil spring 63 does not undergo torsional deformation even if the swing arm 10 swings, and as shown in FIG. 18, when the swing arm 10 swings beyond the range of play. In addition, the torsion coil spring 63 is twisted and deformed according to the magnitude of the swing. A stopper protrusion 69 is formed on the inner edge of the engaging recess 67 in the radial direction so as to face the inner surface of the notch 64 of the sleeve body 61 in the circumferential direction.

As shown in FIG. 18, in the auto tensioner 1 of the third embodiment, when the swing arm 10 rotates relative to the swing support shaft 9 due to the swing of the swing arm 10, the torsion coil spring is rotated by the relative rotation. 63 is twisted and deformed, and the torsion coil spring 63 generates an elastic force in the direction opposite to the swing direction of the swing arm 10. Then, when the swing angle of the swing arm 10 reaches a predetermined size, the stopper protrusion 69 is received by the inner surface of the notch 64 of the sleeve body 61, and the swing arm 10 is further received by the swing arm 10 with respect to the sleeve body 61. Relative rotation is not possible, and the swing arm 10 is locked.

When the auto tensioner 1 of the third embodiment is adopted, the first and

second pulley arms

8a and 8b urged by the first and

second springs

12a and 12b and the swing resistance are adopted as in the first embodiment. Since the swing arm 10 to which the force opposite to the swing direction is applied by the applying mechanism 60 is a separate arm, the operation of absorbing the slack of the belt 6 can be quickly performed, and the belt 6 resonates. It is possible to effectively absorb the vibration of the belt 6 when the belt 6 is used.

Further, in the auto tensioner 1 of the third embodiment, as in the first embodiment, the swing resistance applying mechanism 60 has the outer circumference of the swing support shaft 9 and the inner circumference of the support shaft insertion hole 22 of the swing arm 10. The auto tensioner 1 is compact because it is housed in between. Further, the work of attaching the auto tensioner 1 to the belt transmission device is also easy.

Further, in the auto tensioner 1 of the third embodiment, since the force in the direction opposite to the swing direction generated when the swing arm 10 swings is due to the elastic force of the torsion coil spring 63, the damper is caused by frictional resistance. Compared with the case where a mechanism for generating a force (for example, the swing damping mechanism 32 shown in FIG. 5) is adopted, wear is less likely to occur, and stable performance can be exhibited for a long period of time.

19 to 21 show a fourth embodiment of the present invention. The fourth embodiment is different from the third embodiment only in that there is no stopper protrusion 69 (see FIG. 17), and the other configurations are the same. Therefore, the same reference numerals are given to the parts corresponding to the third embodiment, and the description thereof will be omitted.

As shown in FIG. 20, the first arm portion 65 of the torsion coil spring 63 is a portion that penetrates the notch 64 formed in the sleeve body 61 in the radial direction and projects toward the outer diameter side through the notch 64. Is engaged with the engaging recess 67 formed on the inner surface of the support shaft insertion hole 22, and one end of the torsion coil spring 63 is prevented from rotating by the swing arm 10 due to the engagement. The first arm portion 65 of the torsion coil spring 63 faces the inner surface of the notch 64 of the sleeve body 61 in the circumferential direction.

In the auto tensioner 1 of the fourth embodiment, as shown in FIGS. 20 and 21, when the swing arm 10 rotates relative to the swing support shaft 9 due to the swing of the swing arm 10, the relative rotation causes the swing arm 10 to rotate relative to the swing support shaft 9. The torsion coil spring 63 is twisted and deformed, and the elastic force of the torsion coil spring 63 generates an elastic force in the direction opposite to the swing direction of the swing arm 10. Then, when the swing angle of the swing arm 10 reaches a predetermined size, as shown in FIG. 21, the first arm portion 65 of the torsion coil spring 63 is received by the inner surface of the notch 64 of the sleeve body 61. After that, the swing arm 10 cannot rotate relative to the sleeve body 61, and the swing arm 10 is locked. The action and effect of the auto tensioner 1 of the fourth embodiment is the same as that of the third embodiment.

In the above embodiment, the auxiliary pulley around which the auxiliary belt 6 is wound is provided by two pulleys, a starter generator pulley 3 attached to the rotating shaft 2 of the starter generator and a crank pulley 5 attached to the crankshaft 4. Although the configured auxiliary machine drive system has been described as an example, in the present invention, the auxiliary machine pulley around which the auxiliary machine belt 6 is wound has three or more pulleys (starter generator pulley 3, crank pulley 5, for example. , Other auxiliary pulleys attached to rotating shafts such as car air conditioners and water pumps) can also be applied to auxiliary drive systems.

The embodiments disclosed this time should be considered to be exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and it is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 Auto tensioner for auxiliary machine belt 3 Starter generator pulley 4 Crank shaft 5 Crank pulley 6 Auxiliary machine belt 7a First idler pulley 7b Second idler pulley 8a First pulley arm 8b Second pulley arm 9 Swing support shaft 10 Swing Moving arm 11a First joint portion 11b Second joint portion 12a First spring 12b Second spring 13a First rotation stopper 13b Second rotation stopper 17a First cushioning member 17b Second cushioning member 22 Support shaft insertion hole 25 Fixing member 28 Cam member 32 Swing damping mechanism 33 Shoe member 35 Positioning seat 39 Cam outer peripheral surface 41 Elastic member 43 Shoe inner peripheral surface 45a First pulley body 45b Second pulley body 46b Second Rolling bearing 50 Split shaft 51a First steel plate 51b Second steel plate 52 Coupling pin 60 Swing resistance imparting mechanism 63 Torsion coil spring

Claims

The first and second idler pulleys (7a, 7b) that come into contact with the auxiliary belt (6),
A first pulley arm (8a) that supports the first idler pulley (7a) and
A second pulley arm (8b) that supports the second idler pulley (7b) and
A first joint portion (11a) to which the first pulley arm (8a) is rotatably connected and a second joint portion (11b) to which the second pulley arm (8b) is rotatably connected. A swing arm (9) that is swingably supported around a swing support shaft (9) arranged between the first joint portion (11a) and the second joint portion (11b). 10) and
A first spring (12a) that urges the first pulley arm (8a) in a direction in which the first idler pulley (7a) approaches the second idler pulley (7b).
A second spring (12b) that urges the second pulley arm (8b) in a direction in which the second idler pulley (7b) approaches the first idler pulley (7a).
A swing damping mechanism (32) that generates a damper force in the direction opposite to the swing direction when the swing arm (10) swings around the swing support shaft (9), or the swing. A swing resistance applying mechanism (60) that generates an elastic force in the direction opposite to the swing direction when the arm (10) swings around the swing support shaft (9).
Auxiliary belt for auto tensioner.
The swing arm (10) is formed with a support shaft insertion hole (22) into which the swing support shaft (9) is inserted.
The auto tensioner for an auxiliary belt according to claim 1, wherein the swing damping mechanism (32) or the swing resistance applying mechanism (60) is incorporated in the support shaft insertion hole (22).
The swing damping mechanism (32) is provided in a cam member (28) that is prevented from rotating around the swing support shaft (9) and a support shaft insertion hole (22), and the swing arm (10). The second aspect of the present invention, wherein the cam member (28) and the shoe member (33) are in frictional contact with each other so as to generate a damper force. Auto tensioner for auxiliary belt.
The shoe member (33) is an arc-shaped member provided so as to be movable in the radial direction on the outer side in the radial direction of the cam member (28), and the shoe member (33) is provided with the shoe member (33). The auto tensioner for an auxiliary belt according to claim 3, wherein an elastic member (41) for urging toward the cam member (28) is attached.
The shoe member (33) is a metal leaf spring that is arranged so as to face the radial outer side of the cam member (28) and is deformable in the radial direction by contact with the cam member (28). The auto tensioner for an auxiliary belt according to 3.
The cam member (28) is formed with a convex curved cam outer peripheral surface (39) that projects outward in the radial direction.
The shoe member (33) is formed with a shoe inner peripheral surface (43) that is in frictional contact with the cam outer peripheral surface (39).
The shoe inner peripheral surface (43) becomes larger as the rotation angle increases when the shoe member (33) rotates relative to the cam member (28) due to the swing of the swing arm (10). The auxiliary machine according to any one of claims 3 to 5, which has a shape inclined with respect to the circumferential direction so that the contact surface pressure of the shoe inner peripheral surface (43) with respect to the cam outer peripheral surface (39) gradually increases. Auto tensioner for belt.
When the swing support shaft (9) is fixed to the fixing member (25), a positioning washer (35) that positions the fixing angle of the cam member (28) with respect to the fixing member (25) to a predetermined angle is further added. The auto tensioner for an auxiliary belt according to claim 6.
The rocking resistance applying mechanism (60) has a torsion coil spring (63) having one end stopped by the swinging support shaft (9) and the other end stopped by the swinging arm (10). Item 1. The auto tensioner for an auxiliary belt according to Item 1 or 2.
A first rotation stopper (13a) that receives the first pulley arm (8a) and regulates the rotation angle of the first pulley arm (8a), and a second pulley arm (8b) that receives the second pulley arm (8b). The auto tensioner for an auxiliary belt according to any one of claims 1 to 8, further comprising a second rotation stopper (13b) that regulates the rotation angle of the pulley arm (8b).
A first buffer member (17a) that absorbs an impact when the first rotation stopper (13a) receives the first pulley arm (8a).
The auxiliary belt according to claim 9, further comprising a second cushioning member (17b) that absorbs an impact when the second rotating stopper (13b) receives the second pulley arm (8b). Auto tensioner.
The first idler pulley (7a) is formed on an annular first pulley body (45a) having an outer peripheral surface in contact with the auxiliary belt (6) and an inner circumference of the first pulley body (45a). Consists of a first rolling bearing fitted
The second idler pulley (7b) is provided on the inner circumference of an annular second pulley body (45b) having an outer peripheral surface in contact with the auxiliary belt (6) and the second pulley body (45b). Consists of a second rolling bearing (46b) fitted
The first pulley arm (8a) includes a pair of split shafts (50) that are fitted into the first rolling bearing from both sides in the axial direction, and a pair that supports both ends of the pair of split shafts (50) in the axial direction. The first steel plate (51a), the pair of dividing shafts (50), and the coupling pin (52) that penetrates and joins the pair of first steel plates (51a).
The second pulley arm (8b) supports a pair of split shafts (50) fitted into the second rolling bearing (46b) from both sides in the axial direction, and both ends in the axial direction of the pair of split shafts (50). The claim is composed of a pair of second steel plates (51b), a coupling pin (52) that penetrates and joins the pair of dividing shafts (50) and the pair of second steel plates (51b). The auto tensioner for an auxiliary belt according to any one of 1 to 10.
The starter generator pulley (3) attached to the rotating shaft (2) of the starter generator and
The crank pulley (5) attached to the crankshaft (4) and
The auxiliary belt (6) wound between the starter generator pulley (3) and the crank pulley (5), and the auxiliary belt (6).
The auxiliary belt auto tensioner (1) according to any one of claims 1 to 11 for applying tension to the auxiliary belt (6).
The first idler pulley (7a) is provided in contact with a portion of the auxiliary belt (6) that travels from the crank pulley (5) toward the starter generator pulley (3).
The second idler pulley (7b) is provided in contact with a portion of the auxiliary belt (6) that travels from the starter generator pulley (3) toward the crank pulley (5). system.
The 12th aspect of the present invention, wherein the auxiliary belt auto tensioner (1) is arranged so that the center of the swing support shaft (9) is radially outside the outer circumference of the starter generator pulley (3). Auxiliary drive system.