JPH0379842A - Tensioner - Google Patents

Abstract

PURPOSE:To improve operativity by way of unitizing a mechanical part and a movable shoe by providing the movable shoe which rotates as a mobile force of a pressure body is applied on a casing where the pressure body linearly moves with torque. CONSTITUTION:When a stopper pin is pulled off after a tensioner A is set, a rotor 3 rotates with torque of a coil spring 5 and thereby a pressure body 4 proceeds in the linear direction to work to rotate a movable shoe 7. As the movable shoe 7 always presses a chain with this rotation, the chain maintains a specific tension. In this constitution, the movable shoe 7 is set on a casing 2 and the movable shoe 7 is arranged in one body only by way of fastening the casing 2 on a specific position. Consequently, it is possible to improve operativity as well as simplifying the installation of the tensioner A and making the whole body including the tensioner A and the movable shoe 7 compact.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a tensioner that applies a constant tension to a chain, timing belt, or the like that drives a camshaft of an engine of a two-wheel vehicle or a four-wheel vehicle.

[Prior art] Tensioners such as chain tensioners and belt tensioners are designed to apply a constant tension to a running chain or belt by pressing it in a certain direction when the chain or belt stretches during use or becomes loose due to wear. used. Therefore, the tensioner can always be propelled in the pressing direction.

Because of these characteristics, tensioners have conventionally included a rotating body that is biased to rotate by a coil spring or the like, and a pressing body that is screwed onto the rotating body and moves in a linear direction by the rotational force of the rotating body. The structure is such that these are housed within the casing. The pressing body passes through the bearing attached to the casing, and the opposing surfaces of the pressing body and the bearing are formed into non-circular shapes to restrict rotation of the pressing body, and the tip of the pressing body is in contact with a chain, belt, etc. are in contact with each other. With this structure, the rotation of the rotating body is converted into the propulsive force of the pressing body, and the pressing body always acts to press the chain, belt, etc. In such tensioners, it is necessary to prevent wear on the tip of the pressing body that comes into contact with the chain, belt, etc., and a shoe is interposed between the pressing body and the chain or belt, but this shoe is The equipment is attached to the outside wall.

[Problems to be Solved by the Invention] As described above, the conventional tensioner presses the chain, belt, etc. through the shoe, but since the shoe is attached to the engine separately from the tensioner, it is difficult to attach the tensioner and the shoe. It is necessary to select the location of these components, and it is also necessary to form brackets and the like to attach them to equipment such as engines. Furthermore, it is necessary to individually attach the tensioner and shoe to equipment such as an engine, making assembly into the equipment complicated.

SUMMARY OF THE INVENTION An object of the present invention is to provide a tensioner that solves the above problems by eliminating the need to attach a shoe to equipment such as an engine.

[Means for Solving the Problems] The tensioner according to claim (1) of the present invention includes a casing in which a rotating body that rotates by a spring force and a pressing body that moves linearly by the rotational force of the rotating body are inserted in a screwed state. and a movable shoe whose one end is pivotally supported by the casing and rotates about the pivot in response to the moving force of the pressing body.

Further, the tensioner according to claim (2) of the present invention includes a casing into which a rotating body that rotates by a spring force and a pressing body that moves linearly due to the rotation of the rotating body are inserted in a screwed state, and this casing is fixed. and a movable shoe whose one end is pivotally supported by the plate and rotates about the pivot in response to the moving force of the pressing body.

The spring 1 rotating body and the pressing body, which are the mechanism parts of the tensioner described in claims (1) and (2), are triple-layered in which the pressing body and the spring are sequentially arranged outwards with the rotating body as the center inside the casing. It may be assembled into a structure.

Further, in the tensioner according to claim (1), a fixing shoe may be provided on the side of the casing opposite to the advancing side of the pressing body.

The tensioner according to claim (2) may be provided with a fixing shoe on the side of the plate opposite to the side to which the casing is fixed.

[Operation] The pressing body inserted into the casing in a screwed state with the rotating body advances in the axial direction by the rotation of the rotating body. The movable shoe rotates when the pressing body advances and acts to press the chain, belt, etc., but the movable shoe is attached to the casing or the plate to which the casing is fixed and is integrated with the mechanism of the tensioner. , the movable shoe can be attached simply by attaching the tensioner to equipment such as an engine.

The casing that houses the mechanism of the tensioner can be made smaller by assembling the spring 1, the pressing body 1, and the rotating body, which constitute the mechanism, in a triple structure within the casing.

In addition, a tensioner with a movable shoe and a fixed shoe places a movable shoe on the loose side of the belt or chain to regulate the slack, and a fixed shoe on the tension side of the chain to guide the movement of the chain. do.

[Examples] Hereinafter, the present invention will be specifically described with reference to Examples shown in the accompanying drawings. In each embodiment, the same elements are denoted by the same reference numerals and correspond to each other.

1, 2 and 3 show a first embodiment of the present invention, in which a tensioner A includes a hollow casing 2, a rotating body 3 and a pressing body 4 which are screwed into the casing 2.
, a coil spring 5 that rotates the rotating body 3 , a bearing 6 into which the pressing body 4 is inserted, and a movable shoe 7 that comes into contact with the tip of the pressing body 4 .

The casing 2 has a flange portion 2 in a direction perpendicular to the axial direction.
1.21 is formed on the outer surface, and this flange portion 21
．． The tensioner 1 is fixed by being bolted to the wall of a device such as an engine through a mounting hole 22° 22 formed in the tensioner 21. Also, the tip side of the casing 2 (upper end side in the illustrated example)
A long groove 23 is formed on the inner surface into which a hook portion 51 at one end of a coil spring 5, which will be described later, is inserted.

The rotating body 3 and the pressing body 4 are inserted in the axial direction of the casing 2 in a screwed state.

The rotating body 3 includes a male threaded portion 31 on the tip side and a body portion 32 on the rear end side (lower end side in the illustrated example), and a radially extending collar portion 34 is provided at the boundary between these parts. It is formed in one piece. Further, an axial engagement groove 35 is formed in the rear end surface of the body portion 32 . The hook portion 52 at the other end of the coil spring 5 is inserted into the engagement groove 35, and
A tool (not shown) such as a driver is inserted, and by rotating the rotating body 3 with this tool, an initial torque is applied to the coil spring 5. A stopper pin 8 is inserted into the engagement groove 35 from a direction perpendicular to the axial direction of the casing 2, thereby locking the rotation of the rotating body 3 against the initial torque of the coil spring 5. Note that this stopper bin 8 is removed after being attached to the device, and the rotating body 3 is rotated by the spring force of the coil spring 5. The pressing body 4 is formed in a cylindrical shape and is screwed into the male threaded portion 31 of the rotating body 3. For this reason, a female threaded portion 41 is formed on the inner surface of the pressing body 4 to be screwed into the male threaded portion 31. This pressing body 4 advances in the axial direction as the rotating body 3 rotates to apply tension to the chain, belt, etc., and is provided at the rear end side to prevent it from being pulled out from the casing 2 by advancing in the axial direction. A stopper flange 42 is formed. This advancement of the pressing body 4 is performed by rotating the rotary body 3 by the torque stored in the torsion coil spring 5. In order to rotate the rotary body 3, the body 32 of the rotary body 3 is inserted into the coil portion 53 of the coil spring 5, and the hook portion 51 at one end of the coil spring 5 is inserted into the coil portion 53 of the coil spring 5.
is inserted into the long groove 23 of the casing 2, and the hook portion 52 at the other end is inserted into the engagement groove 35 of the rotating body 3, so that torque is transmitted to the rotating body 3.

The bearing 6 restricts the rotation of the pressing body 4 by being inserted therethrough. This bearing 6 has retaining pieces 61 fitted to the inner surface of the casing 2 formed at 90 degree intervals on the outer circumferential side, and a bearing hole through which the pressing body 4 passes is formed in the center. The bearing hole and the outer peripheral surface of the pressing body 4 are formed into a non-circular shape, such as a substantially oval shape, so that the bearing 6 restrains the rotation of the pressing body 4.

Therefore, the rotational force of the rotating body 3 is converted by the bearing 6 into a propulsive force for linear movement of the pressing body 4, and the pressing body 4 moves in the direction in which a chain, belt, etc. is pressed.

In FIG. 1, 9 is a circlip fitted into the inner surface of the tip end of the casing 2, and serves to prevent the bearing 6 from coming off.
0 is a cylindrical collar into which the pressing body 4 is loosely inserted, and the bearing 6
and the flange portion 34 of the rotating body 4,
The movement of the rotating body 3 in the axial direction is suppressed by the reaction force caused by the thrust of the pressing body 4, thereby preventing the rotating body 3 from wobbling.

The movable shoe 7 is provided outside the tip of the casing 2. The movable shoe 7 is entirely made of a plate curved in an arc shape, and one end in the length direction (in the illustrated example, the right end side)
is rotatably supported on the outside of the casing 2. Therefore, on the outer surface of the tip end of the casing 2, there is a bracket part 24 extending in the radial direction, and a shaft part 2 connected to the bracket part 24.
5 is formed, and a pivot tube 71 is formed on one end side of the movable shoe 7 to be fitted over the shaft portion 25.
The movable shoe 7 is configured to rotate around the shaft portion 25 as the center of rotation. The movable shoe 7 is curved into an arc so as to cover the tip of the casing 2, and the other end opposite to the pivot tube 71 is a free end 72. Further, the central portion of the movable shoe 7 serves as a point of action on which the propulsive force of the pressing body 4 acts. In this embodiment, a cap 11 is fitted onto the tip of the pressing body 4 with a spring pin 12 so that it cannot be removed, and the propulsive force of the pressing body 4 acts through this cap 11. . In this case, the cap 11 has a spherical tip, and a spherical recess 73 is formed in the center of the movable shoe 7 to which the spherical surface of the cap 11 comes into contact. Therefore, the propulsive force of the pressing body 4 acts on the movable shoe 7. Then, due to the action of the propulsive force of the pressing body 4, the movable shoe 7 rotates about the shaft portion 25 of the casing 2 in a direction away from the casing 2 (clockwise in the illustrated example). During this rotation, the contact portion between the cap 11 and the movable shoe 7 slides within the spherical surface and surface contact is maintained, so that the movable shoe 7 rotates smoothly and the pressing body 4 Propulsion force can also be transmitted accurately. Note that a return spring (not shown) may be attached between the pivot tube 71 of the movable shoe 7 and the shaft portion 25 of the casing 2, and this spring may bias the movable shoe 7 in the direction of contact with the cap 11. Can be selected arbitrarily. The spring force of this return spring must be less than the propulsive force of the pressing body 4.

4 and 5 show examples in which the tensioner A described above is used as a chain tensioner. In these figures, the chain 80 is stretched between the driving sprocket 81 and the driven sprocket 82. , the drive sprocket 81 is rotating counterclockwise as shown by the arrow.

In such a structure, the lower side of the chain 80 is the tight side, and the upper side is the loose side, and the chain 8o sag mainly occurs on the slack side. Tensioner A is this chain 80
It is arranged so as to act on the slack side of the fourth
In the figure, it is provided inside the chain 8o so as to press the chain 80 outward, and in FIG. 5, it is provided outside the chain 80 so as to press the chain 8o inward. In these figures, since the movable shoe 7 is attached to the casing 2, the casing 2
By fixing the movable shoe 7 to an engine or the like, the movable shoe 7 comes into contact with the chain 80. In this case, the casing 2 is fixed such that the free end 72 of the movable shoe 7 faces in the running direction of the chain 8o. After such attachment, when the stopper bin 8 is pulled out, the rotating body 3 is rotated by the torque of the coil spring 5, and thereby the pressing body 4 advances in a linear direction and acts to rotate the movable shoe 7. Due to this rotation, the movable shoe 7 constantly presses the chain 80, so that the chain 80 maintains a constant tension. In this embodiment, the movable shoe 7 is attached to the casing 2, and the movable shoe 7 is also integrally provided by simply fixing the casing 2 to a predetermined location.

Therefore, attachment of the tensioner A is simplified, and the entire structure including the tensioner and the movable shoe is made compact, improving ease of handling. In addition, the shoe can be used even for equipment that does not have a bracket for fixing the shoe, and it not only has a wide range of versatility, but also
Greater freedom in device design.

6, 7, and 8 show a tensioner B as a second embodiment. In this embodiment, a movable shoe 7 and a fixed shoe 70 are provided at both ends of the casing 2 in the axial direction, respectively. Of these, the movable shoe 7 has the same structure as the previous embodiment, and is rotated by the propulsive force of the pressing body 4 and acts to press the chain, belt, etc. On the other hand, the fixed shoe 70 is attached to the opposite side of the movable shoe 7 and has the same overall shape as the movable shoe 7. The fixed shoe 70 is attached such that its free end is located opposite the free end of the movable shoe 7. Therefore, a bracket part 26 and a shaft part 27 are integrally extended on the left outer surface of the rear end of the casing 2.
One end side of a fixing shoe 70 is pivotally supported on this shaft portion 27 . Further, a cap 13 is fitted to the rear end of the casing 2, and the fixed shoe 70 is attached to the cap 13.
The center part is in contact with the Such a fixed shoe 70
Unlike the movable shoe 7, the propulsive force of the pressing body 4 does not act on it, but it simply acts as a running guide for the chain belt.As shown in Fig. 9, the movable shoe 7 is attached to the chain belt. The tensioner B is attached to the inside of the belt 80 such that the fixing shoe 70 contacts the slack side of the chain 80 and the tensioner B contacts the tension side of the chain 80.

FIG. 10 shows a tensioner C according to a third embodiment.

The tensioner C has a bracket part 24 for mounting the movable shoe 7 integrally formed with the casing 2 of the tensioner A. Also, the flange part 21 for fixing to the fixed member is formed of a plate separate from the casing, and the mechanism part built into the casing has a triple structure in which a pressing body and a spring are sequentially arranged outward with the rotating body as the center. In terms of structure, tensioner A
There is a difference between

The tensioner C includes a plate 91, a mechanism section 92 attached to the plate 91, and a movable shoe 7.

The plate 91 is a plate-like body with mounting holes 22 and 22 for fixing it to a fixed member such as a side wall of the engine, and the movable shoe 7 and the mechanism part 92 are mounted on the same side of the plate 91.
is installed.

As shown in FIG. 11, the mechanism part 92 has a triple structure in which a pressing body 4 is screwed onto the rotary body 3 from the outside, and a torsion coil spring 5 is disposed further outside of this pressing body 4. It is assembled into.

The pushing body 4 has an open end that is not closed by a cap or the like, and its rotation is restrained by a bearing 6 so that it can move in a straight line. The coil spring 5 is attached so that a hook portion 51 at one end is locked to the casing 2 and a hook portion 52 at the other end is inserted into the retaining groove 35 of the rotating body 3 to impart rotational torque to the rotating body 3. . In such an assembled state, the rotating body 3 is prevented from rotating inadvertently by the torsion spring 5.
The stopper bin 8 is passed through the through hole 95 of the casing 2, and its tip is engaged with the engagement groove 35 of the rotating body 3.

The mechanism section 92 assembled in this manner is attached to the plate 91 so that the open end of the pressing body 4 comes into contact with one side of the substantially center of the movable shoe 7, thereby forming a tensioner C. The tensioner C is attached to the plate 91 in such a way that the other side of the movable shoe 7 is brought into contact with the loose side of the chino 80.
It is fixed through the mounting holes 22, 22 of the holder, and is used by removing the stopper bin 8. At this time, tensioner C operates in the same manner as tensioner A.

In this tensioner C, since the mechanism part 92 has the triple structure described above, it is compact, and even if the pivot point of the movable shoe 7 is provided at a distance from the mechanism part 92, the bracket part 24 can be easily removed like in the tensioner A. There is no lack of strength when the shoe is extended, and the degree of curvature of the movable shoe 7 can be made gentler due to the separation, which has the advantage of suppressing mutual wear between the movable shoe 7 and the ceno 80 as much as possible. be.

FIG. 12 shows a tensioner D according to a fourth embodiment.

The tensioner D is an extension of the plate 91 of the tensioner C, and a fixing shoe 96 is provided at the end of the extension.

In the tensioner D, the mechanism part 92 and the movable shoe 7 are attached to the plate 91 in the same way as the tensioner C, and the sliding surface of the chino 80 is attached to the tip of the plate 91 on the opposite side to the fixed side of the mechanism part 92. A fixing shoe 96 is attached so as to face outward. A substantially U-shaped standing wall 91a is formed at the tip of the plate 91 along the outer shape of the plate 91, and the fixing shoe 96 is attached by caulking 97, 97 along the outer surface of this standing wall 91a. ing.

The fixed shoe 96 is made of the same material 1 as the movable shoe 7, for example, 6,6-nylon.

And in this tensioner D, the movable shoe 7 is
The fixing shoe 96 is used to press the outer surface of the loose side of the cheno to restrict its loosening, and the fixing shoe 96 comes into contact with the inner surface of the tight side of the chino 80 to guide the movement of the chino 80.

FIG. 13 shows a tensioner E according to a fifth embodiment.

The tensioner E has the same structure as the tensioner D except that the sliding surface of the chain 80 of the fixed shoe 96 of the tensioner D is provided facing inward of the plate 91.

The fixing shoe 96 of the tensioner E is formed in a substantially U-shape,
An upright wall 9 formed by bending the tip of a plate 91 at a substantially right angle
An upright wall 91a is attached to the inside of La so as to be wrapped in a U-shape.

This tensioner E has a movable shoe 7 and a fixed shoe 96.
are in contact with the outer surfaces of the loose side and the tight side of the ceno 80, respectively.

Note that the fixing shoes 96 of the tensioners D and E are not necessarily provided on the upright wall 91a formed on the plate 91, but may be directly fixed to the upper surface of the flat plate 91.

Further, as a modification of the tensioner A, the mechanism section of the tensioner A may be a triple structure mechanism section of the tensioner C,
In this case, there is an advantage that the tensioner A can be made more compact.

[Effects of the Invention] As explained above, in the present invention, a movable shoe is attached so that one end is pivotally supported by the casing or a plate to which the casing is attached, and the movable shoe can move a chino, a belt, etc. by the moving force of the pressing body. Since it is pressed, the mechanical part and the movable shoe are integrated into a unit, and the ease of handling is improved.

[Brief explanation of drawings]

1, 2, and 3 are longitudinal sectional views, plan views, and left side views of a first embodiment of the present invention, and FIGS. 4 and 5 are side views showing an example of use as a chain tensioner. 6th
7 and 8 are a longitudinal sectional view, a plan view, and a left side view of the second embodiment, and FIG. 9 is a side view showing an example of its use.
Fig. 10 is a side view showing an example of use of the third embodiment, Fig. 11 is a sectional view taken along line X-X in Fig. 10, Fig. 12 is a side view showing an example of use of the fourth embodiment, and Fig. 13. FIG. 7 is a side view showing an example of use of the fifth embodiment. A, B, C, D, E... Tensioner, 2... Casing, 3... Rotating body, 4... Pressing body 5... Torsion spring, 7... Movable shoe 70.96.・Fixed shoe,
91... Plate. 59 diagrams 10 songs 11 diagrams 12 diagrams

Claims (5)

[Claims] (1) A casing into which a rotating body that rotates by a spring force and a pressing body that moves linearly due to the rotational force of this rotating body are inserted in a screwed state, and one end is pivotally supported by this casing, and the moving force of the pressing body is and a movable shoe that rotates about the pivot portion in response to the tensioner. (2) A casing into which a rotating body that rotates by a spring force and a pressing body that moves linearly due to the rotation of this rotating body are inserted in a screwed state, a plate to which this casing is fixed, and one end of which is pivotally supported by this plate. A tensioner comprising a movable shoe that rotates about the pivot in response to the moving force of the pressing body. (3) The spring, the rotary body, and the pressing body are assembled in a triple structure in which the pressing body and the spring are sequentially arranged outward in a casing with the rotating body as the center. ) or (2). (4) The tensioner according to claim (1), characterized in that a fixing shoe is provided on the side of the casing opposite to the advancing side of the pressing body. (5) The tensioner according to claim (2), characterized in that a fixing shoe is provided on the opposite side of the plate to the side to which the casing is fixed.