JP5521203B2 - Auto tensioner - Google Patents

Description

  The present invention relates to an auto tensioner that keeps a belt tension moderate.

  Patent Document 1 describes a belt tensioning device in which a torsion coil spring, a spring strip, and a damping sleeve are provided between a hub and a housing casing. In this belt tensioning device, one end of the torsion coil spring is in contact with the housing casing, and the other end is in contact with one end of the spring strip. The other end of the spring strip is in contact with a fixed part formed on a lid which is firmly connected to the hub, and a damping sleeve is arranged between the spring strip and the receiving casing. The torsion coil spring is preloaded with a radially expanding preload, which causes the damping sleeve to be pressed against the inside of the receiving casing by the radial expansion of the spring strip. A braking force is generated by further increasing the pressing force against the damping sleeve.

Japanese Patent Laying-Open No. 2006-97898 (FIGS. 1 and 2)

  However, in the belt tensioning device described in Patent Document 1 described above, the damping sleeve is simply sandwiched between the spring strip and the receiving casing by the radial expansion of the spring strip by preloading (the damping sleeve is Therefore, when the preload is not applied to the damping sleeve at all times, when the circumferential force is applied to the damping sleeve, the damping sleeve slides on the outer circumferential surface of the spring strip. . Even if the pressing force against the damping sleeve is properly adjusted by preloading, the pressing force may decrease with long-term use. Thus, when the pressing force with respect to the damping sleeve is reduced, the damping sleeve becomes slippery in the circumferential direction, and the braking force is greatly reduced.

  Therefore, an object of the present invention is to provide an auto tensioner that suppresses a decrease in braking force.

Means for Solving the Problems and Effects of the Invention

Auto-tensioner of the present invention, solid a constant has been based, a rotating member rotatably supported relative to the base, together with the provided rotatably on the rotary member, and the pulley can be brought into contact with the belt A cylindrical member formed between at least one of the base and the rotating member that extends in parallel with a direction from the base toward the rotating member between the base and the rotating member; A coil spring disposed in the cylindrical member and compressed in the axial direction of the cylindrical member with one end locked to the rotating member or the base, and one end to the base or the rotating member and locked, the other end is provided with an arcuate reinforcing member extending along the inner peripheral surface of the other end portion and locked the cylindrical member of said coil spring. The extending direction from the other end of the reinforcing member toward the one end is opposite to the winding direction from the other end of the coil spring toward the one end and the circumferential direction. And the said reinforcement member is arrange | positioned along the internal peripheral surface of the said cylindrical member, and the adjacent thing is comprised by the some block body mutually engaged by pivot engagement, A friction member having an L-shaped cross section that is unmovably coupled from the block body is formed with respect to the extending direction, and the coupling between the block body and the friction member is performed by meshing the unevenness formed with each other. there are, conjugates of the friction member and the block body, so as to be abutted on opposite sides of the coil spring, turn its height along the winding direction of the coil spring is high . The coil spring presses the bottom surface of the friction member against the base or the rotating member by a repulsive force due to the compression, and the outer surface of the friction member is pressed by the rotation of the rotating member. The block body is expanded in a direction in contact with the inner peripheral surface.
The term “locking” as used herein includes those that are stopped by being in contact with each other, those that are locked by being hooked, and those that are fixed in an abutting state by an adhesive or welding.

According to this, since the friction member is coupled to the reinforcing member (block body) by engaging the concave and convex portions , the cylinder can be used even if the friction member is not always urged to contact the inner peripheral surface of the cylindrical member. when the circumferential force to the friction member due to friction with the inner circumferential surface of the member is applied, the friction member hardly slip et respect reinforcing member (block body), it is possible to suppress the reduction of the braking force . Further, since the friction member is pressed against the base (or rotating member) along the winding direction of the coil spring by the repulsive force of the coil spring, the cylindrical member of the reinforcing member (block body) on which the friction member is formed The arrangement state along the inner periphery is stabilized. Therefore, the outer peripheral surface of the friction member comes into surface contact with the inner peripheral surface of the cylindrical member with certainty, and uneven wear is suppressed.
In the present invention, the friction member has an L-shaped cross section. Thereby, the arrangement | positioning state along the internal peripheral surface of the cylindrical member of the reinforcement member (block body) in which the friction member was formed becomes more stable. Further, the contact area between the base (or the rotating member) and the cylindrical member and the friction member can be increased, and the braking effect is also increased.

  Further, in the present invention, the reinforcing member is arranged along the inner peripheral surface of the cylindrical member, and is constituted by a plurality of block bodies in which adjacent members are pivotally engaged with each other, and the friction Since the members are non-movably coupled to the respective block bodies, the respective block bodies change their positional relationship so that the outer peripheral surface of the friction member uniformly contacts the inner peripheral surface of the cylindrical member. Therefore, uneven wear can be reliably suppressed. As a result, the stress can be uniformly distributed in the circumferential direction over a long time.

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

  Here, an embodiment will be described in which the auto tensioner according to the present invention is installed in an engine block of an automobile and the tension of a transmission belt that drives an auxiliary machine of the engine is kept constant.

  Next, an auto tensioner according to an embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a longitudinal sectional view showing the overall configuration of an auto tensioner according to an embodiment of the present invention. FIGS. 2 and 3 are both reference cross-sectional views of the cylindrical member of the auto tensioner shown in FIG. 1 and the inside thereof, FIG. 2 is along the VI-VI line, and FIG. 3 is along the VII-VII line. It is.

  In the present embodiment, the coil spring 4 is disposed inside a cylindrical member 405 formed on the base 402. In addition, the cylindrical member by which the coil spring 4 is arrange | positioned in the inside may be formed in the rotation member.

  The base 402 of the present embodiment includes a bottom wall 3 having a circular planar shape, and a cylindrical member 15 extending upward from a peripheral edge of a through hole 3a formed in the bottom wall 3. Not fixed to the engine block. Furthermore, the base 402 has a cylindrical member 405 extending upward from the peripheral edge thereof. A mounting portion 406 for mounting the base 402 to the engine block protrudes from the outer peripheral surface of the cylindrical member 405. The attachment portion 406 is formed with a through hole 406a into which a bolt (not shown) is inserted.

  The rotating member 421 includes a boss portion 22 and an arm 426 on which the pulley 28 is provided. The rotating member 421 has an annular protrusion 425 that protrudes downward. An annular groove 423 adjacent to the annular protrusion 425 is formed inside the annular protrusion 425 in the rotation member 421. The tip of the cylindrical member 405 formed on the base 402 is located in the concave groove 423 and is separated from the surface of the concave groove 423. The annular protrusion 425 overlaps the outer peripheral surface in the vicinity of the tip of the cylindrical member 405 with a slight gap. This makes it difficult for foreign matter from entering the cylindrical member 405.

  As shown in FIG. 3, the cylindrical member 405 formed on the base 402 is an arc-shaped member extending along the inner peripheral surface 405 a of the cylindrical member 405, and its end (other end) 31 b is A bent reinforcing member (elastic body) 431 is arranged. As shown in FIGS. 2 and 3, the end portion (one end) 31 a of the reinforcing member 431 is fixed in contact with a protrusion 413 formed on the rotating member 421. One end portion (lower end portion in FIG. 1) 4a of the coil spring 4 disposed in a compressed state in the cylindrical member 405 is fixed in contact with the bottom wall 3 of the base 402, and the other end portion. (Upper end portion in FIG. 1) 4b is in contact with the end portion 31b of the reinforcing member 431.

  A friction member 435 made of synthetic resin is fixed to the reinforcing member 431 so as not to move in the extending direction of the reinforcing member 431 by integral molding. The friction member 435 of the present embodiment is an arc-shaped member that extends from the vicinity of one end 31a of the reinforcing member 431 to the vicinity of the other end 31b. As shown in FIG. 3, five protrusions 433 projecting inward are formed on the inner peripheral surface side of the reinforcing member 431. The friction member 435 is formed to wrap around to the outer peripheral surface 432 while engaging with the protrusion 433 formed on the inner peripheral surface. Thereby, the friction member 435 is securely fixed to the reinforcing member 431.

  A plurality of friction members 435 may be movably coupled to the reinforcing member 431. However, as described above, one friction member 435 is movably coupled to the reinforcing member 431 of the present embodiment. Has been. Therefore, in this embodiment, it is preferable that the tensile modulus of the material of the reinforcing member 431 and the friction member 435 is close. In this way, the friction member 435 can be prevented from being damaged due to the difference in tensile elastic modulus with the reinforcing member 431.

  The friction member 435 has a first extending portion 435a and a second extending portion 435b, and has an L-shaped cross-sectional shape. Moreover, the 1st extension part 435a can take the state which contact | abuts with the inner peripheral surface 405a of the cylindrical member 405 across a slight clearance gap, and the state which contact | abuts. In the present embodiment, the second extending portion 435b contacts the rotating member 421. And the 2nd extension part 435b becomes the height in order along the counterclockwise rotation direction in FIG. 3 from the protrusion 413 vicinity so that it can contact | abut with the upper surface part which the adjacent coil spring 4 opposes. Yes.

  With the above-described configuration, when the rotation member 421 rotates in the clockwise direction in FIG. 2 (counterclockwise direction in FIG. 3), the reinforcing member 431 in contact with the protrusion 413 formed on the rotation member 421. On the other hand, a force in the same direction acts. Here, one end 4 a of the coil spring 4 in which the other end 4 b is in contact with the end 31 b of the reinforcing member 431 is in contact with and restrained by the base 402. Therefore, due to the force transmitted from the coil spring 4, the reinforcing member 431 is moved in a direction in which the outer peripheral surface 432 approaches the inner peripheral surface 405a of the cylindrical member 405, that is, in a direction in which the friction member 435 contacts the inner peripheral surface 405a. Try to spread. Thus, a braking force acts on the rotating member 421.

  As described above, the auto tensioner 401 according to the present embodiment can suppress a decrease in braking force. Further, since the upper surface of the friction member 435 is pressed against the rotating member 421 by the repulsive force of the coil spring 4, the arrangement along the inner peripheral surface 405a of the cylindrical member 405 of the reinforcing member 431 on which the friction member 435 is formed. The installation state is stabilized and uneven wear is suppressed.

  Next, the cylindrical member of the auto tensioner according to the present embodiment and the cross section inside thereof will be described below with reference to FIGS. 4 and 5. 4 and 5 are cross-sectional views of the cylindrical member of the auto tensioner according to the present embodiment and the inside thereof, FIG. 4 is a view corresponding to FIG. 3 which is a reference cross-sectional view, and FIG. 5 is a reference cross-sectional view. FIG. 3 is a diagram corresponding to FIG. 2.

  In this embodiment, the configurations of the reinforcing member 431 and the friction member 435 of the auto tensioner 401 in FIGS. 2 and 3 are changed, and other configurations are substantially the same as those in FIG. In the following description, components having substantially the same configurations as those in FIGS. 2 and 3 are denoted by the same reference numerals and description thereof is omitted as appropriate.

  As shown in FIGS. 4 and 5, in the auto tensioner 501 of the present embodiment, the arc-shaped reinforcing member 531 extending along the inner peripheral surface 405 a of the cylindrical member 405 is disposed along the inner peripheral surface 405 a. It is composed of two block bodies 532 and 533. One end portion of the block body 532 constituting the reinforcing member 531 is an end portion 31 a that comes into contact with the protrusion 413 formed on the rotating member 421. Further, one end portion of the block body 533 is an end portion 31 b that comes into contact with the end portion 4 b of the coil spring 4.

  The end 532a opposite to the one end 31a of the block body 532 and the end 533a opposite to the one end 31b of the block 533 are pivotally engaged. That is, the contact portion between the end portion 532a of the block body 532 and the end portion 533a of the block body 533 is movable in the width direction of the block bodies 532 and 533 (the radial direction of the arcuate auxiliary member 531). The positional relationship between the block body 532 and the block body 533 is changed by moving the contact portion between the end portion 532a of the block body 532 and the end portion 533a of the block body 533.

  In addition, the friction member 535 according to the present embodiment is fixedly coupled to each of the block body 532 and the block body 533 constituting the reinforcing member 531 so as to be a combined body. The friction member 535 fixed to the block body 532 has an arc shape extending from the vicinity of one end 31a of the block body 532 to the vicinity of the other end 532a. Further, the friction member 535 fixed to the block body 533 has an arc shape extending from the vicinity of one end portion 533a of the block body 533 to the vicinity of the other end portion 31b.

  With the configuration as described above, when the rotating member 421 rotates counterclockwise in FIG. 4 (clockwise in FIG. 5), the block body 532 is in contact with the protrusion 413 formed on the rotating member 421. And the force of the same direction acts with respect to the block body 533 pivot-engaged with the block body 532, respectively. At this time, the block body 532 and the block body 533 constituting the reinforcing member 531 are deformed by the force transmitted from the coil spring 4 whose one end 4 a is restrained by the base member 402, and the inner peripheral surface 405 a of the cylindrical member 405. In the direction in which the friction member 535 comes into contact with the inner peripheral surface 405a. Thus, a braking force acts on the rotating member 421.

  As described above, the auto tensioner 501 of the present embodiment can suppress a reduction in brake force and uneven wear, like the auto tensioner 401 in FIGS.

  Further, in the auto tensioner 501 of the present embodiment, the reinforcing member 531 is configured by two block bodies 532 and 533 that are pivotally engaged with each other. Therefore, the block bodies 532 and 533 can change the positional relationship with each other so that the friction member 535 fixed to the block bodies 532 and 533 abuts uniformly on the inner peripheral surface 405a of the cylindrical member 405. As a result, uneven wear can be reliably suppressed, and stress can be uniformly distributed in the circumferential direction over a long period of time.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. For example, in the present embodiment, the case where one friction member 535 is coupled to each of the two block bodies 532 and 533 constituting the reinforcing member 531 has been described, but the friction member coupled to the reinforcing member The number is not limited to these. The friction member preferably has an L-shaped cross section.

  In the above-described embodiment, one end 4a of the coil spring 4 is locked by contacting the boss 22 (or the bottom wall 3), but the boss 22 (or the bottom wall 3). The coil spring 4 and the rotating member 421 (or the base 402) may be locked by forming a hole in the hole, bending the end 4a, and entering and hooking the end 4a. Furthermore, you may fix with the adhesive agent or welding in the state which the rotation member 421 (or base 402) and the coil spring 4 contacted. Further, not only one end 4a of the coil spring 4, but also the other end 4b and the end 31b of the reinforcing member (block body), and the end 31a of the reinforcing member (block body) and the base 2 (or the rotation). The protrusion 13 (or 413) formed on the moving member 421) may be locked as described above, or may be fixed in contact with each other. That is, the coil spring, the reinforcing member (block body), the rotating member, and the base need only be engaged with each other and stopped.

  Furthermore, although the case where the reinforcing member 531 is configured by the two block bodies 532 and 533 has been described in the above-described embodiment, the reinforcing member 531 may be configured by three or more block bodies.

  In the present embodiment, the friction member and the reinforcing member (block body) are integrally formed. However, the friction member may be any one of synthetic resin, brass, plated brass, bronze, and plated bronze. When it consists of these, you may fix both with the adhesive agent. In this case, it is preferable to appropriately select an adhesive having good adhesive compatibility between the friction member and the reinforcing member (block body). Further, when the friction member is made of any one of brass, plated brass, bronze, and plated bronze, both may be fixed by brazing. Even in these cases, as described above, even if a circumferential force is applied to the friction member, the friction member hardly slides in the circumferential direction with respect to the reinforcing member (block body).

Further, the reinforcing member (block body) and the friction member may be joined by engaging the unevenness. In this case, the reinforcing member (block body) is made of metal, and the friction member is not limited to being made of bronze, but the friction member is made of synthetic resin, brass, whose main component is one of nylon resin, polyacetal resin, or polyarylate resin. Further, it may be made of any one of plated brass and plated bronze.
In this configuration, since the friction member is coupled to the reinforcing member (block body) by engaging the concave and convex portions, friction is caused even when the circumferential force of the friction member is generated by the friction member coming into contact with the inner peripheral surface. The member hardly slides against the reinforcing member (block body).
As for the engagement of the reinforcing member (block body) and the friction member, the reinforcing member (block body) is coupled to the reinforcing member (block body) by being fitted into the penetrating portion in a state of protruding from the outer peripheral surface of the reinforcing member (block body). It may be what is done. The reinforcing member (block body) may be formed with a jagged uneven portion instead of the penetrating portion, and the uneven portion corresponding to the uneven portion may be formed on the friction member. And the reinforcement member (block body) and the friction member are couple | bonded because these uneven | corrugated | grooved parts mesh | engage.

It is a longitudinal section showing the whole auto tensioner composition by the embodiment of the present invention. It is a reference sectional view which meets a VI-VI line of the principal part in the auto tensioner shown in FIG. It is a reference sectional view which meets a VII-VII line of an important section in the auto tensioner shown in FIG. It is sectional drawing of the auto tensioner by this embodiment, and is a figure equivalent to FIG. FIG. 5 is another sectional view of the auto tensioner shown in FIG. 4 and corresponds to FIG. 2.

401, 501 Auto tensioner 402 Base 4 Coil spring 4a End (one end)
4b end (the other end)
405 Cylindrical member 405a Inner peripheral surface 421 Rotating member 28 Pulley 531 Reinforcing member 31a End (one end)
31b end (other end)
535 Friction member 532, 533 Block body

Claims (1)

With a fixed base,
A rotating member supported rotatably with respect to the base;
A pulley rotatably provided on the rotating member and capable of contacting the belt;
A cylindrical member formed on at least one of the base and the rotating member, extending in parallel with the direction from the base toward the rotating member between the base and the rotating member;
A coil spring disposed in the cylindrical member and having one end locked to the rotating member or the base in a compressed state in the axial direction of the cylindrical member;
An arc-shaped reinforcing member having one end locked with the base or the rotating member and the other end locked with the other end of the coil spring and extending along the inner peripheral surface of the cylindrical member. And
The extending direction from the other end of the reinforcing member toward the one end is opposite to the winding direction from the other end of the coil spring toward the one end and the circumferential direction,
The reinforcing member is arranged along the inner peripheral surface of the cylindrical member, and is constituted by a plurality of block bodies in which adjacent members are pivotally engaged with each other,
Each of the block bodies is formed with a friction member having an L-shaped cross section that is coupled to the block body so as not to move with respect to the extending direction thereof.
The combination of the block body and the friction member is an engagement of the irregularities formed with each other,
The combined body of the block body and the friction member has a height that increases in order along the winding direction of the coil spring so as to be able to contact the opposing surface of the coil spring.
The coil spring presses the bottom surface of the friction member against the base or the rotating member by a repulsive force due to the compression, and the outer surface of the friction member is pressed by the rotation of the rotating member. An auto tensioner, wherein the block body is expanded in a direction in contact with the inner peripheral surface.