WO2015159782A1

WO2015159782A1 - Tensioner

Info

Publication number: WO2015159782A1
Application number: PCT/JP2015/061044
Authority: WO
Inventors: 隆広伊藤; 芳幸高橋; 貴雄小林
Original assignee: 日本発條株式会社
Priority date: 2014-04-14
Filing date: 2015-04-08
Publication date: 2015-10-22
Also published as: JP6431049B2; JPWO2015159782A1; BR112016024025A2; CN106415067B; BR112016024025B1; CN106415067A

Abstract

Provided is a tensioner capable of being more compact as a result of having a concentric arrangement of constituent components and capable of preventing undulations or twisting during winding up of a coil spring. A tubular guide section (13) is formed on a bearing (6) that restricts rotation of a second shaft member (4); a spring-locking slit (18) is formed in the guide section (13); an other-side hook section (5c) of a coil spring (5) that rotates and impels a first shaft member (3) is pulled to the outside from the spring-locking slit (18) and is movably locked in the guide section (13). Undulations and twisting do not occur in a coil section (5a) even if the number of coil section (5a) windings increase during winding up of the coil spring (5), as a result of the other-side hook section (5c) moving along the guide section (13) in accordance with said increase.

Description

Tensioner

The present invention relates to a tensioner that is attached to an engine body of an automobile and applies tension to a timing chain or a timing belt in the engine body.

The tensioner that applies tension to the timing chain and timing belt in the engine body is attached to the outer surface of the engine body, and the rotational force that is rotated by the torque of the spring is converted into propulsive force to It functions to press. Therefore, the tensioner restrains the rotation of the first shaft member and the second shaft member that are screwed together, a spring such as a coil spring and a mainspring spring that urges the first shaft member to rotate, and the rotation of the second shaft member. A bearing that converts rotational force to the second shaft member into propulsive force, a case that accommodates these and attached to the outer surface of the engine body, and a spacer that prevents the first shaft member and the second shaft member from falling off the case And have.

On the other hand, in order to adapt the tensioner to a small vehicle or a two-wheeled vehicle, the tensioner has been downsized. In reducing the size, it is preferable that the stroke of the second shaft member that is propelled to press the timing chain or the timing belt is not reduced in terms of securing the tension of the timing chain or the timing belt.

For this reason, conventionally, a spacer is disposed outside the first shaft member and the second shaft member that are screwed together, and a coil spring is disposed outside the spacer to form an assembly, and the assembly is accommodated in a case. A tensioner having a concentric quadruple structure from the inner side to the outer side in the radial direction has been developed (see Patent Document 1). By adopting a concentric quadruple structure in this way, it is not necessary to have a structure in which the components are arranged in the length direction, so that it is possible to reduce the size while securing the stroke of the second shaft member.

Japanese Patent No. 2079172

In the conventional tensioner reduced in size by adopting the quadruple structure, one side hook portion of the coil spring is engaged with the winding slit of the first shaft member, and the other side hook portion is engaged with the groove portion in the case. The structure is stopped. In such a structure, if the coil spring is wound up by rotating the first shaft member, the number of turns of the coil portion of the coil spring increases and the coil portion extends, so that the locking position of the other hook portion is the coil portion. It changes along the axial direction. However, since the other side hook portion is locked to the groove portion of the case and torque acts, the degree of freedom of displacement in the axial direction is reduced, and an unreasonable force acts on the coil portion from the other side hook portion. As a result, undulation or entanglement may occur in the coil portion, and the coil spring may not be stably wound up.

This will be described with reference to a quadruple tensioner 300 shown in FIG. The tensioner 300 in FIG. 15 includes a pair of shaft members including a first shaft member 330 and a second shaft member 340 that are screwed together by a screw portion, a cylindrical spacer 370 that surrounds the outside of the pair of shaft members, and a spacer 370. A four-fold assembly is formed by a coil spring 350 that surrounds the outside. In this assembly, the coil portion 351 of the coil spring 350 surrounds the outer side of the spacer 370, while the one-side hook portion 352 of the coil spring 350 is a winding fastening slit 331 at the base end portion (lower end portion) of the first shaft member 330. The other side hook portion 353 is locked to the case 310. The tensioner 300 is assembled by incorporating such a quadruple structure assembly into the case 310 and fixing the bearing 360 that restricts the rotation of the second shaft member 340 to the distal end (upper end). And the torque which rotates the 1st shaft member 330 is given by rotating the 1st shaft member 330 by the winding shaft inserted in the slit 331 for winding, and winding up the coil spring 350.

In such a tensioner 300, when the overall length is shortened for miniaturization, the overall length of the coil spring 350 needs to be shortened. For this reason, the number of turns of the coil portion 351 of the coil spring 350 is reduced. When the number of turns of the coil part 351 of the coil spring 350 is reduced, the difference between the diameter of the coil part 351 in the free state and the diameter of the coil part 351 when the coil spring 350 is wound up after being set on the tensioner 300 increases. . This tendency becomes conspicuous because the number of turns of the coil spring 350 decreases as the tensioner 300 is reduced in size, and the difference between the inner diameter L2 of the coil portion of the coil spring 350 and the diameter L1 of the spacer 370 inside the coil spring 350 is increased. Becomes larger. When such a coil spring 350 is wound up, since the degree of freedom of displacement of the other side hook portion 353 in the axial direction is small, the coil spring 350 is swelled or entangled.

The present invention has been made in consideration of such a problem, and is a tensioner that enables downsizing by a concentric arrangement structure of component parts, and is used for urging the first shaft member. It is an object of the present invention to provide a tensioner capable of preventing swell and entanglement during winding of a coil spring.

In the tensioner of the present invention, a first shaft member and a second shaft member are screwed together by a screw portion, and the pair of shaft members propelled by the second shaft member by rotation of the first shaft member, and the pair of shaft members A cylindrical spacer disposed so as to surround the outside of the coil, a coil spring disposed so as to surround the outside of the spacer, and a coil spring capable of rotating to urge the first shaft member, and a plate-like attachment A quadruple structure comprising a bearing that is fixed to the member and arranged so as to surround the outside of the coil spring, the bearing being fixed to the mounting member, and A guide portion that extends in a cylindrical shape in the propulsion direction of the second shaft member and surrounds the outside of the coil spring and a tip portion of the guide portion, and the second shaft member is rotated. The coil spring has a hook portion on one side locked to the first shaft member and a hook portion on the other side locked to the bearing. A tensioner that rotationally biases the first shaft member, wherein a spring locking slit extending in the axial direction of the pair of shaft members is formed in the guide portion, and the other hook portion of the coil spring is the spring engagement member. The other hook portion is movable in the length direction of the guide portion in accordance with the increase / decrease in the number of coil turns of the coil spring by being pulled out from the stop slit and locked to the guide portion. Features.

In the present invention, it is preferable that a notch portion into which the other hook portion of the coil spring enters and engages is formed in the spring locking slit.
Moreover, it is preferable that the said notch part becomes the taper shape which spreads gradually along the propulsion direction of the said 2nd shaft member.
Moreover, it is preferable that the said notch part is provided in the part which the said other side hook part reaches at the winding end of a coil spring, and is extended linearly along the circumferential direction of the said coil spring.

According to the present invention, the cylindrical guide portion is formed in the bearing that rotationally restrains the second shaft member, the spring locking slit is formed in the guide portion, and the coil spring that rotates and biases the first shaft member is provided. The other side hook portion is pulled out from the spring locking slit and locked to the guide portion. As a result, the other side hook portion can move in the length direction of the guide portion in accordance with the increase or decrease of the number of coil turns of the coil spring, and even if the number of turns of the coil portion increases or decreases during winding of the coil spring, the increase or decrease Following this, the other side hook portion can move along the guide portion. For this reason, an excessive stress does not act on a coil part at the time of winding of a coil spring, and a wave | undulation and an entanglement do not generate | occur | produce in a coil part. As a result, the coil spring can be stably wound up.

It is a longitudinal cross-sectional view which shows the tensioner of 1st Embodiment of this invention. It is a top view of the tensioner of a 1st embodiment. (A) is a top view of a coil spring, (b) is a front view. (A) is a top view of a bearing, (b) is a longitudinal cross-sectional view, (c) is a bottom view. It is a front view which shows the tensioner of the state before winding up of a coil spring. FIG. 6 is a plan view of FIG. 5. It is a front view which shows the tensioner of the state after winding up of a coil spring. FIG. 8 is a plan view of FIG. 7. It is a front view which shows the state before winding up of the coil spring in the tensioner of 2nd Embodiment. FIG. 10 is a plan view of FIG. 9. It is a front view which shows the state after winding up of the coil spring in the tensioner of 2nd Embodiment. It is a top view of FIG. It is a front view which shows the state after winding up of the coil spring in the tensioner of 3rd Embodiment. FIG. 14 is a plan view of FIG. 13. It is sectional drawing of the conventional structure of the tensioner miniaturized by the quadruple structure.

Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments. In addition, in each embodiment, the same code | symbol is attached | subjected and corresponded to the same member.

(First embodiment)
1 to 8 show a tensioner 1 according to an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of the entire tensioner 1, and FIG. 2 is a plan view. 3 shows a coil spring, FIG. 4 shows a bearing, and FIGS. 5 to 8 show operating states.

As shown in FIGS. 1 and 2, the tensioner 1 includes a mounting member 2, a pair of

shaft members

3, 4, a coil spring 5, a bearing 6, and a spacer 7.

The mounting member 2 is formed in a thick plate shape and is attached to the engine body (not shown). In order to attach to the engine body, the attachment member 2 has a plurality of attachment holes 2a penetrating in the plate thickness direction, and bolts (not shown) can penetrate the attachment holes 2a (see FIG. 2). ). In FIG. 1, reference numeral 2b denotes a mounting surface on which the mounting member 2 comes into contact with the outer surface of the engine main body. With the mounting surface 2b in contact with the outer surface of the engine main body, a bolt is inserted into the mounting hole 2a and screwed into the engine main body. As a result, the tensioner 1 is attached to the engine body. A bearing 6 is fixed to the mounting member 2. For this reason, the fixing member 2 is formed with a plurality of fixing grooves 2c that are recessed from the mounting surface 2b in the thickness direction. As shown in FIG. 2, each fixing groove 2c is formed in a substantially arc shape when viewed from above, and a fixing piece 16 of a bearing 6 described later is press-fitted into the fixing groove 2c.

The pair of

shaft members

3 and 4 includes a first shaft member 3 and a second shaft member 4 screwed together, and the second shaft member 4 is propelled in the engine body by rotating the first shaft member 3. It has become.

As shown in FIG. 1, the first shaft member 3 is integrally formed with a shaft portion 3a on the mounting member 2 side (base end side) and a screw portion 3b extending in the axial direction from the shaft portion 3a. A male screw portion 8 is formed on the outer periphery of the screw portion 3b. The rotation of the base end portion of the shaft portion 3 a is supported by abutting against a receiving seat 19 press-fitted into the mounting member 2. Further, a winding slit 3c into which a winding jig 20 for rotating the first shaft member 3 is inserted is formed on the base end surface of the shaft portion 3a. By inserting the winding jig 20 into the winding slit 3c and rotating the first shaft member 3, the coil spring 5 described later can be wound up. After the winding, the sealing plug 21 is fitted to close the winding tightening hole outside the winding slit 3c.

The second shaft member 4 is formed in a cylindrical shape, and an internal thread portion 9 into which the external thread portion 8 of the first shaft member 3 is screwed is formed on the inner surface thereof. The second shaft member 4 propels the inside of the engine body as the first shaft member 3 rotates, and presses the timing chain and the timing belt in the engine body to apply these tensions. A cap 10 is put on the tip of the second shaft member 4.

The coil spring 5 is formed by a coil part 5a extending along the axial direction of the pair of

shaft members

3 and 4 in a screwed state, and one side hook part 5b and the other side hook part 5c at both ends of the coil part 5a. (See FIG. 3). As shown in FIG. 3, the one-side hook portion 5 b is bent inward from the coil portion 5 a and is inserted into the winding slit 3 c on the proximal end surface of the first shaft member 3 to be locked. The other hook portion 5c is bent outward from the coil portion 5a and is locked to a bearing 6 described later. In such a structure, by rotating the first shaft member 3, the coil spring 5 can be wound up and torque can be applied, and the coil spring 5 rotationally biases the first shaft member 3 by this torque.

The bearing 6 serves to restrain the rotation of the second shaft member 4 and is formed by a guide portion 13, a fixing portion 14, and a sliding hole 15 as shown in FIGS. The fixed portion 14 is fixed to the mounting member 2, and the guide portion 13 extends in a cylindrical shape from the fixed portion 14 toward the propulsion direction of the second shaft member 4. Thereby, the guide part 13 is in a state of rising from the mounting surface 2b of the mounting member 2 toward the front (upward in FIG. 1). The extending end portion of the guide portion 13 is a bent portion 13a bent radially inward, and the sliding hole 15 is formed in the bent portion 13a.

The second shaft member 4 is slidably penetrated through the sliding hole 15. The inner surface of the sliding hole 15 is formed in an oval shape, a parallel cut, a rectangular shape, or other non-circular shape. The outer surface of the second shaft member 4 penetrating the sliding hole 15 is also formed in a non-circular shape corresponding to the sliding hole 15, whereby the bearing 6 restrains the rotation of the second shaft member 4. . In such a structure, when the first shaft member 3 is rotated by the torque of the coil spring 5, the second shaft member 4 screwed with the first shaft member 3 is linearly propelled in the axial direction without rotating. In addition, tension is applied to the timing chain and the timing belt.

The fixing portion 14 is connected to the guide portion 13 in a state where the fixing portion 14 is bent from the proximal end portion of the guide portion 13 in an intersecting direction that is substantially orthogonal. In this embodiment, the fixing portion 14 is formed by a plurality (four) of fixing pieces 16 bent radially from the base end portion of the guide portion 13. Each fixed piece 16 is formed by a bent portion 16a bent radially outward from the base end portion of the guide portion 13, and a folded portion 16b folded in the rising direction of the guide portion 13 from the end portion of the bent portion 16a. Yes. The folded portion 16b is formed in a substantially arc shape having a size corresponding to the fixing groove 2c (see FIG. 2) of the mounting member 2, and the folded portion 16b is press-fitted into the fixing groove 2c of the mounting member 2. Thus, the bearing 6 is fixed to the mounting member 2 in a state where the bearing 6 rises from the mounting member 2. Then, by fixing the mounting member 2 to the engine body so that the mounting surface 2b is in contact with the outer surface of the engine body, the fixing piece 16 is sandwiched between the mounting member 2 and the outer surface of the engine body. The tensioner 1 can be stably attached to the engine body.

The bearing 6 is formed with a spring locking slit 18. As shown in FIG. 4, the spring locking slit 18 is formed by cutting out a part of the guide portion 13 of the bearing 6 along the length direction. Accordingly, the spring locking slit 18 extends along the propulsion direction of the second shaft member 4 in the same manner as the guide portion 13. In this embodiment, the spring locking slits 18 are formed at two opposing positions of the guide portion 13, but may be one or three or more. As shown in FIG. 1, the spring locking slit 18 pulls out the other hook portion 5c of the coil spring 5 to the outside of the bearing 6, and the other hook portion 5c pulled out from the spring locking slit 18 is a guide. Locked to the portion 13.

The spacer 7 is formed in a cylindrical shape, and a lower end portion in the length direction is an inner bent portion 7a bent inward in the radial direction, and an outer end portion in which the upper end portion in the length direction is bent outward in the radial direction. It is a bent portion 7b. The inner bent portion 7 a is in contact with the proximal end surface of the second shaft member 4, and the outer bent portion 7 b is in contact with the bent portion 13 a of the guide portion 13 in the bearing 6. Thus, the spacer 7 prevents the pair of

shaft members

3 and 4 from coming out of the bearing 6.

In this embodiment, by inserting the pair of

shaft members

3 and 4 in a screwed state into the spacer 7, the spacer 7 is disposed so as to surround the outside of the pair of

shaft members

3 and 4. The coil spring 5 is disposed so as to surround the outer side of the spacer 7, and the one-side hook portion 5 b of the coil spring 5 is inserted into the winding slit 3 c of the first shaft member 3 and locked. Then, the second shaft member 4 is passed through the sliding hole 15 of the bearing 6, and the pair of

shaft members

3 and 4 in a screwed state are attached to the bearing 6. At this time, the other hook portion 5 of the coil spring 5 is pulled out from the spring locking slit 18 of the bearing 6 to the outside of the bearing 6 and is locked to the guide portion 13 of the bearing 6 to form an assembly assembly. Thereafter, the fixing piece 16 of the bearing 6 is press-fitted into each fixing groove 2 c of the mounting member 2 to fix the bearing 6 to the mounting member 2, and the mounting member 2 is mounted on the engine body to form the tensioner 1.

In such a structure, a quadruple structure in which a spacer 7 surrounds the outer side of the pair of

shaft members

3 and 4 in a screwed state, a coil spring 5 surrounds the outer side of the spacer 7, and a bearing 6 surrounds the outer side of the coil spring 5. It becomes. For this reason, the total length can be shortened. And since the rear-end part of the 2nd shaft member 4 can move within the guide part 13 of the bearing 6, the inside of the guide part 13 can be used as an effective stroke. Thereby, even if the overall length is shortened, the stroke of the second shaft member 4 can be secured, and good tension can be applied to the timing chain and the timing belt in the engine body.

Furthermore, in this embodiment, the spring locking slit 18 is formed in the length direction in the guide portion 13 of the bearing 6, and the other hook portion 5 c of the coil spring 5 is pulled out from the spring locking slit 18 to guide the guide portion 13. Therefore, the other side hook portion 5c is arranged in the length direction of the guide portion 13 according to the increase / decrease of the coil diameter accompanying the increase / decrease in the number of coil turns at the time of winding and unwinding of the coil spring 5 (spring engagement). The other side hook portion 5c can move to the front side of the guide portion 13 when the coil spring 5 is wound up. 5 to 8 show the action of pulling out the other hook portion 5c.

5 and 6 show a state before the coil spring 5 is wound up, and the second shaft member 4 has advanced forward from the bearing 6. At this time, as shown in FIG. 5, the coil portion 5 a of the coil spring 5 is expanded and shortened, and the other hook portion 5 c of the coil spring 5 extends in the length direction of the guide portion 13 of the bearing 6. The guide portion 13 is locked at an approximately middle portion. 7 and 8 show a state in which the first shaft member 3 is rotated by the winding jig 20 and the coil spring 5 is wound up. As the coil spring 5 is wound up, the number of turns of the coil portion 5a increases, and the coil portion 5a expands while the coil diameter of the coil portion 5a is reduced. At this time, since the other hook portion 5c of the coil spring 5 is movable along the length direction of the guide portion 13, the other hook portion 5c follows the increase in the number of turns of the coil portion 5a. 13 can move forward. For this reason, an unreasonable stress does not act on the coil part 5a when the coil spring 5 is wound up, and no swell or entanglement occurs in the coil part 5a. Therefore, the coil spring 5 can be wound up stably. Further, when the second shaft member 4 propels the inside of the engine body, the number of coil turns of the coil spring 5 is reduced and the coil diameter is expanded. When the coil spring 5 is expanded, the other side hook portion is 5 c moves to the rear side along the guide portion 13. For this reason, the second shaft member 4 can be smoothly promoted.

(Second Embodiment)
9 to 12 show a tensioner 1A according to a second embodiment of the present invention. FIGS. 9 and 10 show the coil spring 5 before winding, and FIGS. 11 and 12 show the coil spring 5 after winding.

In the tensioner 1A, the notch portion 31 is formed in the guide portion 13 of the bearing 6 with respect to the tensioner 1 of the first embodiment, and other configurations are the same as those of the first embodiment.

As with the tensioner 1 of the first embodiment, the bearing 6 is fixed to the mounting member 2 by press-fitting a plurality of fixing pieces 16 into the fixing grooves 2 c of the mounting member 2. By fixing to the mounting member 2, the guide portion 13 of the bearing 6 rises from the mounting member 2 so as to extend in the propulsion direction of the second shaft member 4. Inside the guide portion 13 of the bearing 6, a pair of

shaft members

3, 4, a spacer 7, and a coil spring 5 in a screwed state are sequentially arranged from the inner side to the outer side in the radial direction.

In the guide portion 13, a spring locking slit 18 is formed so as to extend along the axial direction of one

shaft member

3, 4, and the other hook portion 5 c of the coil spring 5 is formed in the spring locking slit 18. It is pulled out to the outside and is locked to the guide portion 13. A notch 31 is formed in the spring locking slit 18 of this embodiment. The notch 31 is a groove for the other hook portion 5c of the coil spring 5 to enter and engage therewith. The notch 31 is formed from an intermediate portion in the length direction of the guide portion 13 in the spring locking slit 18 to a tip portion (a portion where the other hook portion 5c reaches the winding end portion of the coil spring 5).

In this embodiment, the cutout 31 is formed in a tapered shape that gradually spreads along the propulsion direction of the second shaft member 4. That is, the notch portion 31 is formed in the guide portion 13 so as to be inclined at an angle α with respect to the propulsion direction of the second shaft member 4. The angle α is appropriately set within a range of about 0 ° to 30 ° according to the coil diameter of the coil spring 5. Such a tapered notch 31 is pulled out from the spring locking slit 18 and locked to the guide portion 13, and the other hook portion 5 c of the coil spring 5 is coiled when the coil spring 5 is wound and unwound. It becomes a guide surface that slides while engaging as the coil diameter expands or contracts with the increase or decrease of the number of turns.

9 and 10 show a state before the coil spring 5 is wound up, and the second shaft member 4 has advanced forward from the bearing 6. At this time, as shown in FIG. 5, the coil portion 5 a of the coil spring 5 is expanded and shortened, and the other hook portion 5 c of the coil spring 5 is the length of the guide portion 13 of the bearing 6. It is located in the middle part of the direction and is locked to the guide part 13. 11 and 12 show a state where the coil spring 5 is wound up. As the coil spring 5 is wound up, the number of turns of the coil portion 5a increases, and the coil portion 5a expands while the coil diameter of the coil portion 5a is reduced. As the number of coil turns of the coil portion 5a increases, the other hook portion 5c moves forward along the guide portion 13 while sliding on the tapered cutout portion 31, and reaches the winding end portion. That is, the other side hook portion 5 c moves along the tapered notch 31 following the expansion and contraction of the diameter as the coil diameter increases due to the winding of the coil spring 5. In such an operation of the other-side hook portion 5c, excessive stress does not act on the coil portion 5a when the coil spring 5 is wound up, so that no swell or entanglement occurs in the coil portion 5a. Therefore, the coil spring 5 can be wound up stably. When the second shaft member 4 propels the inside of the engine body, the number of coil turns of the coil spring 5 decreases and the coil diameter increases, but when the coil spring 5 is expanded, the other side hook portion 5c. Moves to the rear side along the tapered notch 31, so that the second shaft member 4 can be smoothly promoted.

(Third embodiment)
13 and 14 show a tensioner 1B according to a third embodiment of the present invention, and shows a state after the coil spring 5 is wound up.

Also in the tensioner 1B of this embodiment, the spring locking slit 18 is formed in the guide portion 13 of the bearing 6, and the notch 33 is formed in the spring locking slit 18. Other configurations are the same as those of the first embodiment.

The notch 33 is provided at a portion where the other side hook portion 5 c reaches at the winding end of the coil spring 5. Such a notch 33 is provided at the end of the spring locking slit 18 in the length direction. The cutout portion 33 extends linearly along the circumferential direction of the coil spring 5 at this portion. In this structure, before the coil spring 5 is wound up, the coil portion 5 a is pulled in the axial direction, and the other hook portion 5 c is locked to the notch portion 33. Due to this locking, the other side hook portion 5 c remains in the cutout portion 33. When the coil spring 5 is wound up in this state, the tip (upper end) of the coil portion 5a extends to the vicinity where the notch portion 33 is located and matches the axial direction. With such a structure, it is possible to cope with changes in the coil diameter and length when the coil spring 5 is wound up, and no excessive stress is applied to the coil spring 5 at the time of winding, and swells and entanglements are generated in the coil. Since it does not generate | occur | produce in the part 5a, the coil spring 5 can be wound up stably.

DESCRIPTION OF

SYMBOLS

1, 1A, 1B Tensioner 3 1st shaft member 4 2nd shaft member 5 Coil spring 5a Coil part 5b One side hook part 5c Other side hook part 6 Bearing 7 Spacer 13 Guide part 14 Fixing part 15 Sliding hole 16 Fixed piece 18 Spring locking slits 31, 33 Notch

Claims

A pair of shaft members, wherein the first shaft member and the second shaft member are screwed together by a threaded portion, and the second shaft member is propelled by rotation of the first shaft member;
A cylindrical spacer disposed so as to surround the outside of the pair of shaft members;
A coil spring which is disposed so as to surround an outer side of the spacer, and which can be wound up to rotate and bias the first shaft member;
It is fixed to a plate-shaped mounting member and has a quadruple structure consisting of a bearing arranged so as to surround the outside of the coil spring.
The bearing includes a fixed portion fixed to the mounting member, a guide portion extending in a cylindrical shape from the fixed portion toward the propulsion direction of the second shaft member, and surrounding the outer side of the coil spring, and the guide portion Formed by a sliding hole that penetrates and slides in a state in which the second shaft member is rotationally restricted,
The coil spring is a tensioner in which one side hook portion is locked to the first shaft member and the other side hook portion is locked to the bearing to urge the first shaft member to rotate,
A spring locking slit extending in the axial direction of the pair of shaft members is formed in the guide portion,
The other hook portion of the coil spring is pulled out from the spring locking slit and is locked to the guide portion, so that the other hook portion of the guide portion is adjusted according to the increase or decrease of the number of coil turns of the coil spring. A tensioner characterized by being movable in the length direction.
2. The tensioner according to claim 1, wherein a notch portion into which the other hook portion of the coil spring enters and engages is formed in the spring locking slit.
The tensioner according to claim 2, wherein the notch has a tapered shape that gradually spreads along the propulsion direction of the second shaft member.
3. The tensioner according to claim 2, wherein the notch portion is provided at a portion where the other side hook portion reaches at a winding end of the coil spring and extends linearly along a circumferential direction of the coil spring. .