WO2016006471A1

WO2016006471A1 - Tensioner

Info

Publication number: WO2016006471A1
Application number: PCT/JP2015/068433
Authority: WO
Inventors: 隆広伊藤; 貴雄小林
Original assignee: 日本発條株式会社
Priority date: 2014-07-08
Filing date: 2015-06-25
Publication date: 2016-01-14
Also published as: JPWO2016006471A1; CN106536981B; CN106536981A; JP6499173B2

Abstract

Provided is a tensioner for suppressing retraction of the appearing margin position of a propulsion member and spring fatigue fracturing which occur over time, and preventing output loss due to excessive tension. A tensioner (1) is accommodated in a case (5) with a rotating member (3) and a propulsion member (2) threaded together by a screw part (6), the rotating member (3) is rotatably urged by the torque of a spring (4), the propulsion member (2) is made to reciprocate relative to the case (5) by the rotation of the rotating member (3), and one end surface of the rotating member (3) slides over a receiving surface (7) of the case (5), whereby sliding resistance is created between the rotating member (3) and the receiving surface (7) along with the rotation of the rotating member (3). The sliding resistance during rotation of the rotating member (3) in a first rotation direction (11), corresponding to the retraction of the propulsion member (2), is set to be great enough to suppress the rotation of the rotating member (3) in the same direction (11), and the sliding resistance during rotation of the rotating member (3) in a second rotation direction (12), corresponding to the advancing of the propulsion member (2), is set to be great enough to suppress the rotation of the rotating member (3) in the same direction (12).

Description

Tensioner

The present invention relates to a tensioner that adjusts the tension of a belt or chain so as to keep it constant.

The tensioner is used for an engine of a motor vehicle such as a two-wheeled vehicle or a four-wheeled vehicle, for example, and when the engine timing chain or the timing belt is pushed with a predetermined force, the tensioner is elongated or loosened. , Acts to keep the tension constant.

FIG. 11 shows a state in which the tensioner 200 is mounted on the engine body 300 of the automobile. A pair of cam sprockets 310 and a crank sprocket 320 are arranged inside the engine body 300, and a timing chain 330 is stretched between these

sprockets

310 and 320 in an endless manner. A chain guide 340 is swingably disposed on the moving path of the timing chain 330, and the timing chain 330 moves while sliding on the chain guide 340. The tensioner 200 is fixed to the engine main body 300 in a state where the engine main body 300 is inserted so as to pass through a mounting hole 360 formed in the engine main body 300.

FIG. 12 shows a general structure of the tensioner 200. A cylindrical propelling member 210, a shaft-like rotating member 230 that is screwed to the propelling member 210 by a screw portion 220, a spring 240 such as a coil spring that applies rotational torque to the rotating member 230, and a case 250 that accommodates these. The case 250 is fixed to the engine main body 300 by bolting or the like. The propulsion member 210 is constrained from rotating by a bearing member 260 attached to the front end portion of the case 250, so that the propulsion member 210 advances with respect to the case 250 by the rotational force of the rotating member 230 transmitted through the screw portion 220. Then, the timing chain 330 is pressed. On the other hand, when the tension of the timing chain 330 increases, the propelling member 210 moves backward while rotating the rotating member 230 in the reverse direction. By these operations, the tension of the timing chain 330 is kept constant.

In such a tensioner 200, a dish-shaped receiving member 270 is provided inside the case 250. The receiving member 270 is a receiving surface that abuts the one end surface 231 of the rotating member 230 and slides in a contact state. When the receiving member 270 and the one end surface 231 of the rotating member 230 are in contact with each other, if the vibration (input load) from the engine is large, the sliding portion changes from a static friction state to a dynamic friction state. Decreases. That is, the frictional resistance of the sliding portion between the receiving member 270 and the rotating member 230 and the frictional resistance of the screw portion 220 in which the propelling member 210 and the rotating member 230 are screwed are reduced. In this state, when the propulsion member 210 receives a large vibration (alternate load) from the engine, the rotating member 230 rotates greatly to increase the return amount of the propelling member 210 and the timing chain flutters. For this reason, it is necessary to increase the sliding resistance between the receiving member 270 (hereinafter referred to as the receiving surface) and the one end surface 231 of the rotating member 230. Conventionally, the receiving surface and the rotating member are brought into contact with each other on a continuous surface. The structure (refer patent document 1) and the structure (refer patent document 2) which form an uneven | corrugated serration in a receiving surface and a rotation member, and mesh | engage mutually are developed.

Japanese Patent Laid-Open No. 2001-50056 JP2013-142441A

As described above, the propelling member and the rotating member are screwed together by the screw portion and accommodated in the case, the rotating member is rotationally biased by the spring, and one end surface of the rotating member is the receiving surface of the case (receiving member 270). In the tensioner having the structure shown in FIG. 12 that slides on the rotary member, the following three torques 1 to 3 act on the rotating member, and the balance position of these torques determines the starting position of the propelling member and the timing chain. It is designed to suppress abnormal behavior.
Torque 1 ... Rotational torque in the backward direction (return) of the propulsion member generated in the screw portion when engine vibration (alternate load) accompanying the fluctuation in the tension of the timing chain is input to the propulsion member Torque 2 ... Rotation Resistance torque of sliding friction when one end surface of the member slides on the receiving surface Torque 3 ... Torque in the advancing direction urged by the spring

Such a structure has the following problems.
(1) When the frictional resistance of the sliding portion of the threaded portion and the sliding portion of the one end surface of the rotating member decreases due to long-term use, torque 1 increases and torque 2 decreases. For this reason, the allowance position of the propelling member tends to move backward, and the rotational movement angle (return operation) of the rotating member due to engine vibration increases.
(2) Under a situation where the period of the rotational motion is close to the natural frequency in the rotational direction of the spring, excessive stress is locally generated, and fatigue failure due to stress concentration is likely to occur. In particular, when the rotational motion angle of the rotating member exceeds approximately 70 °, the stress concentration near the hook where the spring is locked to the rotating member increases, and fatigue failure tends to occur in this portion.
(3) When the response to increasing the torque 2 and the torque 3 is performed in order to suppress the rotational movement angle of the rotating member, the protruding position of the propelling member tends to advance, thereby increasing the tension of the timing chain and the engine Loss of output.
The torque 2 can be increased by increasing the contact diameter of one end face of the rotating member as described in, for example,

Patent Documents

1 and 2, and the torque 3 can be increased by, for example, a spring torque. This is possible by increasing (biasing force). In such an increase in the torque 2 and the torque 3, the resistance torque is increased by increasing the diameter of the one end face of the rotating member. Therefore, the resistance in the backward (returning) direction of the propulsion member increases and the propulsion member It becomes difficult to return. Further, the torque of the screw directly acts on the rotating member to constantly urge the propelling member in the advance direction. In such a structure, at the moment when the waveform of the engine vibration (alternating load) is at the minimum value, the load acting on the screw surface and one end surface of the rotating member becomes small. At this moment, the torque of the spring is always applied to the rotating member. Since it is acting, the rotating member rotates strongly so as to fill a gap in the advancing direction of the propelling member, and the propelling member advances momentarily and unnecessarily. In Patent Document 2, since the torsion spring is not used, the coil spring urges the propulsion member in the advance direction, but the rotation torque of the rotation member (rotation torque in the direction in which the propulsion member advances) is increased. Since the torque to be converted is small and the serrations on the one end surface of the rotating member are formed with uneven serrations, the propulsion member moves in the advancing direction when the lead angle of the screw and the inclined surface angle of the unevenness on the serrations are approximately equal. There are also inconveniences that cannot be activated.

The present invention has been made in consideration of such problems, and it is possible to prevent the propulsion member from moving backward and the fatigue failure of the spring over time, and to prevent output loss due to excessive tension. The purpose is to provide a simple tensioner. *

The tensioner according to the present invention is housed in a case in a state where the rotating member and the propelling member are screwed together by a threaded portion, the rotating member is rotated and biased by a torque of a spring, and the propelling member is rotated by the rotation of the rotating member. The sliding member generates a sliding resistance between the rotating member and the receiving surface as the rotating member rotates by sliding the one end surface of the rotating member with the receiving surface of the case. And the sliding resistance during rotation of the rotating member in the first rotation direction corresponding to the backward movement of the propulsion member is set to a size capable of suppressing rotation of the rotating member in the same direction, The sliding resistance during rotation of the rotating member in the second rotation direction corresponding to the advancement of the propelling member is set to a size capable of suppressing the rotation of the rotating member in the same direction. To do.

In this case, the first inclined surface corresponding to the first rotation direction and the second inclined surface corresponding to the second rotation direction intersect with the advancing / retreating direction of the propelling member on the one end surface and the receiving surface of the rotating member. It is preferable to form continuously in the state inclined with respect to the predetermined angle.

In addition, it is preferable that the angle θ1 of the first slope is set so that the sum of the rotational torque of the rotating member, the rotational torque of the threaded portion, and the torque of the spring expressed by Formula 1 is greater than zero. .
W × R1 · tan (ρ1 + θ1) + W × R2 · tan (ρ2−θL) + T> 0
... Formula 1
(Wherein, W is an input load to the propulsion member, R1 is a contact radius to the receiving portion of one end surface of the rotating member, ρ1 is a friction angle of one end surface of the rotating member, ρ2 is a friction angle of the screw portion, and R2 is (The thread surface contact diameter of the thread portion, θL is the lead angle of the thread portion, and T is the torque of the spring.)

Further, it is preferable that the angle θ1 of the first slope is set smaller than the angle θ2 of the second slope.

Further, it is preferable that the first slope and the second slope are continuous via a corner portion, and the corner portion is formed in an R shape.

Further, it is preferable that one slope body having a triangular section is formed by the first slope and the second slope adjacent to the first slope, and the slope body is arranged on the circumference at an arrangement angle of 70 ° or less. .

According to the present invention, it is possible to suppress retraction of the starting position of the propelling member and the fatigue failure of the spring over time, and to prevent output loss due to excessive tension.

1 shows a first embodiment of the present invention and is an overall sectional view of a tensioner. FIG. It is a fragmentary perspective view of a rotation member. It is a perspective view of a receiving member. It is sectional drawing which shows the contact state of a rotating member and a receiving member. It is sectional drawing of a slope body. It is an end view which shows arrangement | positioning of the slope body in a rotation member. 2nd Embodiment of this invention is shown, (a) And (b) is the front view and right view of a rotating member. (A) And (b) is the front view and right view of a shaft main body of 2nd Embodiment. (A), (b) and (c) are the left view, the front view, and the right view of the corrugated member of 2nd Embodiment. It is sectional drawing which shows another example of the contact state of a rotating member and a receiving member. It is a front view which shows the state which mounted | wore the engine main body with the tensioner. It is sectional drawing which shows the conventional tensioner.

[First Embodiment]
1 to 6 show a first embodiment of the present invention, FIG. 1 is an overall sectional view of a tensioner 1, FIG. 2 is a partial perspective view of a rotating member 3, and FIG. 3 is a perspective view of a receiving member 7 as a receiving surface. 4 is a cross-sectional view showing a contact state between the rotating member 3 and the receiving member 7, FIG. 5 is a cross-sectional view of the inclined body, and FIG. 6 is an end view showing the arrangement of the inclined body in the rotating member 3.

As shown in FIG. 1, the tensioner 1 includes a propelling member 2 and a rotating member 3 that are screwed together, a spring 4, and a case 5 that accommodates these members.

The propulsion member 2 presses the timing chain 230 (see FIG. 10) of the engine main body, is formed in a cylindrical shape, and is inserted into the case 5 so as to freely advance and retract. The propulsion member 2 linearly advances from the front end portion of the case 5 by pressing the rotational force of the rotating member 3 and presses the timing chain, while the engine body load (alternate load) is input from the timing chain. By this, it recedes linearly and rotates the rotating member 3 in the reverse direction. In order to convert the rotation of the rotating member 3 into the forward / backward movement of the propelling member 2, the through hole 51 at the tip portion of the case 5 through which the propelling member 2 passes is formed in an oval or rectangular non-circular shape, and The outer surface is formed in a corresponding non-circular shape. In FIG. 1, the arrow FD is the advance direction of the propelling member 2, and the arrow BK is the backward direction.

The propelling member 2 and the rotating member 3 are accommodated in the case 5 while being screwed together. Therefore, a female screw 61 is formed on the inner surface of the propelling member 2 and a male screw 62 is formed on the outer surface of the rotating member 3, and the female screw 61 and the male screw 62 are screws that screw the propelling member 2 and the rotating member 3 together. It is part 6.

The rotating member 3 is a shaft body integrally including a screw forming portion 31 on the propelling member 2 side on which a male screw 62 is formed and a shaft portion 32 extending from the screw forming portion 31 to the rear side in the axial direction. The shaft portion 32 is rotatably supported by a receiving member 7 provided on the case 5, whereby the entire rotating member 3 can rotate in the forward and reverse directions within the case 5.

The spring 4 is formed of a coil spring, the coil portion 43 is externally inserted into the shaft portion 32 of the rotating member 3, the hook portion 41 on one side is locked to the case 5, and the hook portion 42 on the other side is locked to the rotating member 3. Locked to the shaft portion 32. In this case, the other hook portion 42 is locked to the shaft portion 32 by being inserted into an axial slit 33 formed in the shaft portion 32. The spring 4 stores torque that rotates the rotating member 3 by being tightened, and the rotating member 3 is rotated by the torque of the spring 4.

The case 5 is fixed to the engine body by bolting or the like. A receiving member 7 as a receiving surface for supporting the shaft portion 32 of the rotating member 3 is provided at the rear end portion in the case 5. The receiving member 7 is fixed to the case 5 by being press-fitted into the support recess 52 at the rear end of the case 5. An end surface 34 (hereinafter referred to as one end surface 34) on the shaft portion 32 side of the rotating member 3 is in contact with the receiving member 7, and the rotation of the rotating member 3 is supported by this contact.

In the above structure, the rotating member 3 is rotated by the torque of the spring 4, and the rotation of the rotating member 3 is transmitted from the screw portion 6 to the propelling member 2, so that the propelling member 2 advances in the direction of arrow FD (hereinafter referred to as advance FD). Press the timing chain. On the other hand, when the timing chain is tensioned by the alternating load from the engine body and the load is input to the propulsion member 2, the propulsion member 2 moves backward in the direction of the arrow BK (hereinafter referred to as reverse BK). In this backward movement, the rotating member 3 rotates in the reverse direction via the screw portion 6. In the following description, the rotation direction of the rotation member 3 corresponding to the backward movement BK of the propulsion member 2 is described as a first rotation direction 11, and the rotation direction of the rotation member 3 corresponding to the advancement FD of the propulsion member 2 is described as a second rotation direction 12. To do. In the rotation of the rotation member 3 in these rotation directions, the one end surface 34 of the rotation member 3 slides on the surface of the receiving member 7, so that sliding resistance is generated.
In the present invention, the sliding resistance during rotation of the rotating member 3 in the first rotation direction 11 corresponding to the backward movement BK of the propelling member 2 is such that the rotation resistance of the rotating member 3 in the same direction 11 can be suppressed. Is set to be In this way, by suppressing the rotation of the rotation member 3 in the first rotation direction 11, the operation of the propulsion member 2 in the backward BK direction can be suppressed. Further, in the present invention, the sliding resistance when the rotating member rotates in the second rotation direction corresponding to the advancement FD of the propelling member 2 is also large enough to suppress the rotation of the rotating member 3 in the same direction 12. Is set to be By suppressing the rotation of the rotating member 3 in the second rotation direction 12 in this manner, the operation of the propelling member 2 in the advance FD direction can be suppressed, and the output loss is reduced.

FIG. 2 shows the shaft portion 32 of the rotating member 3. The first inclined surface 13 and the second inclined surface 14 are formed on the one end surface 34 of the shaft portion 32 of the rotating member 3 so as to be alternately positioned on the circumference in a state where they are adjacent to each other. FIG. 3 shows a receiving member 7 on which the rotating member 3 slides. The entire receiving member 7 is formed in a dish shape, and the bottom surface 71 is formed so that the first inclined surface 15 and the second inclined surface 16 are adjacent to each other on the circumference. The first slopes 13 and 15 and the

second slopes

14 and 16 are processed by forging, cutting, or other means.

The rotating member 3 is assembled to the case 5 so that one end surface 34 of the rotating member 3 faces the bottom surface 71 of the receiving member 7, and by this assembly, the first

inclined surfaces

13, 15 and the second

inclined surfaces

14, 16 are formed on them. It becomes the state which the unevenness | corrugation which becomes becomes engaged. Therefore, when the rotating member 3 rotates in the first rotating direction 11, the first inclined surface 13 of the rotating member 3 slides on the first inclined surface 15 of the receiving member 7, and the rotating member 3 rotates in the second rotating direction 12. When doing so, the second slope 14 of the rotating member 3 slides on the second slope 16 of the receiving member 7. That is, in the rotation of the rotating member 3 in the first rotation direction 11, the first

inclined surfaces

13 and 15 slide with each other, while in the rotation of the rotating member 3 in the second rotation direction, the second

inclined surfaces

14 and 16 are in contact with each other. It slides. Therefore, the rotating member 3 rotates while generating sliding resistance with the receiving member 7 when rotating in any of the first rotating direction 11 and the second rotating direction 12.

As described above, the first inclined surface 13 of the rotating member 3 and the first inclined surface 15 of the receiving member 7 are formed corresponding to the first rotating direction 11 of the rotating member 3, and the second inclined surface 14 of the rotating member 3 and the receiving member 7. The second inclined surface 16 is formed corresponding to the second rotation direction of the rotating member 3. As shown in FIG. 4, the first

inclined surfaces

13 and 15 and the second

inclined surfaces

14 and 16 are formed on the propulsion member 2. It is formed continuously so as to incline at a predetermined angle with respect to the surface 19 intersecting perpendicularly with the advancing / retreating direction (retreating BK and advancing FD).

FIG. 5 shows the first slope 13 and the second slope 14 in the rotating member 3. The first inclined surface 13 and the second inclined surface 14 stand in an inclined state having respective angles θ1 and θ2 from a surface 19 (see FIG. 4) that intersects perpendicularly with the advancing and retreating direction of the propelling member 2. The angle θ1 of the first slope 13 is set to be smaller than the angle θ2 of the second slope 14, whereby the first slope 13 is longer than the second slope 14. The angle relationship between θ1 and θ2 is the same for the first inclined surface 15 and the second inclined surface in the receiving member 7. By setting in this way, when the rotating member 3 rotates in the first rotation direction 11 corresponding to the backward movement BK of the propelling member 2, the first inclined surface 13 of the rotating member 3 slides on the first inclined surface 15 of the receiving member 7. The sliding resistance increases due to movement. On the other hand, when the rotating member 3 rotates in the second rotation direction 12 corresponding to the advancement FD of the propelling member 2, the second inclined surface 14 of the rotating member 3 slides on the second inclined surface 16 of the receiving member 7, so that the sliding The torque in the advancement FD direction of the propulsion member 2 is weakened by the dynamic resistance, and excessive advancement of the propulsion member 2 can be suppressed.

In the structure of the present embodiment, when the rotating member 3 rotates in the first rotating direction corresponding to the backward BK direction of the propelling member 2, the first inclined surface 13 does not get over the first inclined surface 15 on the receiving member 7 side. Cannot rotate in the direction. For this reason, the backward tendency of the propelling member 2 can be suppressed. Since the backward tendency can be suppressed in this way, it is possible to suppress an increase in the rotation angle of the rotating member 3 due to the input of engine vibration (alternate load). And since it can suppress that the rotation angle of the rotation member 3 becomes large, excessive stress does not concentrate on the hook part 42 of the other side of the spring 4 latched by the rotation member 3, and the hook of the other side The stress concentration near the portion 42 can be relaxed, and the occurrence of fatigue failure due to the stress concentration can be prevented.

On the other hand, when the rotating member 3 rotates in the second rotating direction corresponding to the advance FD direction of the propelling member 2, the rotating member 3 rotates in the same direction unless the second inclined surface 14 gets over the second inclined surface 16 on the receiving member 7 side. Can not do it. For this reason, the advancing tendency of the propelling member 2 can be suppressed. By suppressing the advancement tendency of the propelling member 2 in this way, an increase in the tension of the timing chain due to excessive advancement of the propelling member 2 can be suppressed, and loss of engine output can be reduced. And as mentioned above, since the sliding resistance at the time of the movement of the propulsion member 2 in both the backward and forward movement directions increases, it is possible to stabilize the advance / retreat behavior of the propulsion member 2 without having to increase the torque of the spring 4. It becomes possible.

In the tensioner 1 of FIG. 1, the angle of the

first slopes

13 and 15 is θ1, the input load from the engine to the propulsion member 2 is W, the contact radius of the end surface 34 of the rotating member 3 to the receiving member 7 is R1, The friction angle of one end surface 34 of the rotating member 3 is ρ1, the friction angle of the screw portion 6 is ρ2, the screw surface contact diameter of the screw portion 6 is R2, the lead angle of the screw portion 6 is θL, and the torque of the spring 4 is T. In this case, the sliding torque generated on the one end surface 34 of the rotating member 3 sliding with the receiving member 7 is W × R1 · tan (ρ1 + θ1), and the sliding torque generated on the screw portion 6 is W × R2. Tan (ρ2-θL) Here, the sliding torque W × R1 · tan (ρ1 + θ1) of the one end surface 34 of the rotating member 3 and the sliding torque W × R2 · tan (ρ2−θL) generated in the threaded portion 6 act in opposite directions. The sliding torque W × R1 · tan (ρ2 + θ1) of the one end surface 34 of the rotating member 3 and the torque T of the spring 4 act in the same direction.

From the above, in the tensioner 1, Equation 1 is established.
W × R1 · tan (ρ1 + θ1) + W × R2 · tan (ρ2−θL) + T> 0
... Formula 1

In Equation 1, when the sum is larger than zero, the rotational force of the rotating member 3 in the backward BK direction of the propelling member 2, that is, the first rotating direction 11 may be generated with respect to the input load from the engine. Absent. The friction angles ρ1 and ρ2 decrease due to deterioration over time, and when the sum of Equation 1 becomes smaller than zero due to the decrease, the propelling member 2 operates greatly in the backward BK direction. For this reason, the angle θ1 of the

first slopes

13 and 15 is set so that Equation 1 ensures zero or more in relation to the deteriorated friction angles ρ1 and ρ2.

In the actual tensioner design, the values of the friction angles ρ1 and ρ2 in Formula 1 vary with the magnitude of the engine vibration (alternate load) (input load W), and the larger the engine vibration, the smaller the friction angles ρ1 and ρ2 (dynamic friction). Coefficient). In the static state, the friction angles ρ1 and ρ2 are about 6.8 °. In the dynamic state, the friction angles ρ1 and ρ2 change according to the input load W. At the largest input load W, ρ1 and ρ2 are about 2 to 3 °. Become. Considering such changes in the friction angles ρ1 and ρ2, for example, when W = 100 N, R1 = 4.5 mm, R2 = 4 mm, θL = 12 °, and T = 1.0 Nmm, θ1 is 4.9 °. It is preferable to make it about or more.

As shown in FIG. 4, the first inclined surface 13 of the rotating member 3 and the adjacent second inclined surface 14 are continuous via the corner portion 21, and the second inclined surface 16 adjacent to the first inclined surface 15 of the receiving member 7. Is continuous through the corner 23. In this embodiment, these corners 21 and 23 are formed in a rounded R shape. By making the corner portions 21 and 23 R-shaped, the load can be dispersed and stress concentration can be suppressed. Thereby, rotation to the 1st rotation direction 11 and the 2nd rotation direction of the rotation member 3 can be made smooth.

In this embodiment, as shown in FIG. 4, a slope 17 having a triangular cross section is formed by the first slope 13 in the rotating member 3 and the second slope 14 adjacent thereto, and the first slope in the receiving member 7. 15 and the second inclined surface 16 adjacent thereto form one inclined body 18 having a triangular cross section. FIG. 6 shows the arrangement of the inclined body 17 in the circumferential direction of the rotating member 3. 6 and 5, A is an arrangement angle on the circumference of the first slope 13, B is an arrangement angle on the circumference of the second slope 14, and the slope body is a circle with an arrangement angle of C = A + B. It is good to arrange them equally on the circumference. In this case, the other side hook portion 42 of the spring 4 is locked to the rotating body 3, and stress concentrates on the other side hook portion 42 of the spring 4 due to the rotation of the rotating body 3, and fatigue failure is likely to occur. Become. On the other hand, by making the arrangement angle C of the sloped body 17 70 degrees or less, the stress concentration on the spring 4 can be dispersed, and the risk of fatigue failure of the spring 4 can be reduced.

In the above embodiment, the angle θ1 of the

first slopes

13 and 15 is set smaller than the angle θ2 of the second slopes 14 and 16 (θ1 <θ2), but the angle θ1 is set larger than the angle θ2. Is also possible (θ1> θ2). FIG. 10 shows a case where the angle θ1 of the

first slopes

13 and 15 is set larger than the angle θ2 of the

second slopes

14 and 16. By setting θ1> θ2 in this way, the rotation of the rotating member 3 in the first rotation direction 11 when the engine vibration is large can be suppressed, so that the backward movement BK of the propelling member 2 can be suppressed, and the propelling member 2 can be prevented from returning too much.
Although the receiving member 7 is assembled to the case 5 to serve as the receiving surface of the rotating member 3, the receiving surface of the rotating member 3 may be processed directly into the case 5.

[Second Embodiment]
7 to 9 show a second embodiment of the present invention. As shown in FIG. 7, the rotating member 3 is formed by the screw forming portion 31 in which the male screw 62 is formed and the shaft portion 32 extending coaxially from the screw forming portion 31, and one end surface 34 of the shaft portion 32. The first slope 13 and the second slope 14 are formed along the circumferential direction. In this embodiment, the rotating member 3 of FIG. 7 is configured by a combination of a shaft main body 36 shown in FIG. 8 and a corrugated member 37 shown in FIG.

As shown in FIG. 8, the shaft body 36 includes a screw forming portion 31 in which a male screw 62 is formed and a shaft portion 32 extending coaxially from the screw forming portion 31. The first slope 13 and the second slope 14 are not formed. A semicircular arc-shaped attachment portion 35 is only formed on the end surface portion of the shaft portion 32. On the other hand, as shown in FIG. 9, the first inclined surface 13 and the second inclined surface 14 are formed along the circumference on one end surface 34 of the corrugated member 37. A semi-arc-shaped ring body 39 is formed on the other end surface 38 of the corrugated member 37 on the shaft main body 36 side, and the corrugated member 37 is formed by connecting the ring body 39 to the mounting portion 35 of the shaft main body 36 by press fitting. Are connected to the shaft member 36 to be integrated. Thereby, the rotation member 3 shown in FIG. 7 is producible.

In such a structure, since the corrugated member 37 can be exchanged, it can be exchanged to the first inclined surface 13 and the second inclined surface 14 having different inclination angles, or to the inclined body 17 having different arrangement angles on the circumference. The replacement can be easily performed, and the required tensioner characteristics can be easily accommodated.

DESCRIPTION OF SYMBOLS 1 Tensioner 2 Propulsion member 3 Rotating member 4 Spring 5 Case 6 Thread part 7 Receiving member 11 1st rotation direction 12

2nd rotation direction

13, 15

1st slope

14, 15

2nd slope

17, 18 Slope body 19 Intersecting surface 21 , 23 corners

Claims

The rotating member and the propelling member are accommodated in the case in a state where the rotating member and the propelling member are screwed together, the rotating member is rotationally biased by the torque of the spring, and the propelling member moves forward and backward with respect to the case by the rotation of the rotating member. A structure in which a sliding resistance is generated between the rotating member and the receiving surface as the rotating member rotates by sliding one end surface of the rotating member with the receiving surface of the case;
The sliding resistance at the time of rotation of the rotating member in the first rotation direction corresponding to the backward movement of the propelling member is set to a size capable of suppressing the rotation of the rotating member in the same direction,
The sliding resistance when the rotating member rotates in the second rotating direction corresponding to the advancement of the propelling member is set to a size capable of suppressing the rotation of the rotating member in the same direction. Tensioner.
A tensioner according to claim 1, wherein
The first inclined surface corresponding to the first rotation direction and the second inclined surface corresponding to the second rotation direction on one end surface and the receiving surface of the rotating member with respect to a surface intersecting the advancing / retreating direction of the propulsion member A tensioner characterized by being formed continuously in an inclined state at a predetermined angle.
A tensioner according to claim 2,
The angle θ1 of the first slope is set so that the sum of the rotational torque of the rotating member, the rotational torque of the threaded portion, and the torque of the spring represented by Formula 1 is greater than zero. Tensioner.
W × R1 · tan (ρ1 + θ1) + W × R2 · tan (ρ2−θL) + T> 0
... Formula 1
(Wherein, W is an input load to the propulsion member, R1 is a contact radius to the receiving portion of one end surface of the rotating member, ρ1 is a friction angle of one end surface of the rotating member, ρ2 is a friction angle of the screw portion, and R2 is (The thread surface contact diameter of the thread portion, θL is the lead angle of the thread portion, and T is the torque of the spring.)
A tensioner according to claim 2 or 3,
The tensioner according to claim 1, wherein the angle θ1 of the first slope is set smaller than the angle θ2 of the second slope.
A tensioner according to any one of claims 2 to 4,
The tensioner, wherein the first slope and the second slope are continuous via a corner, and the corner is formed in an R shape.
A tensioner according to any one of claims 2 to 5,
The first inclined surface and the second inclined surface adjacent thereto form one inclined body having a triangular cross section, and the inclined body is arranged on the circumference at an arrangement angle of 70 ° or less. Tensioner.