WO2003052295A1

WO2003052295A1 - Tensioner

Info

Publication number: WO2003052295A1
Application number: PCT/JP2002/013255
Authority: WO
Inventors: Tanehira Amano; Takao Kobayashi
Original assignee: Nhk Spring Co., Ltd.
Priority date: 2001-12-18
Filing date: 2002-12-18
Publication date: 2003-06-26
Also published as: JP3962817B2; CN1606667A; JP2003184968A; AU2002354218A1; CN100398871C

Abstract

The amplitude of a second shaft member of a tensioner to which an externally applied load is applied is suppressed minutely. A first shaft member (3) and a second shaft member (4), screwed together by thread portions (8), (9), and a torsion spring (5) urging rotationally the first shaft member (3) in one direction are received in a case (2). By restricting the rotation of the second shaft member (4), rotational urging force of the torsion spring (5) is converted into propulsion force of the second shaft member (4). An elastic member (20) for generating a resistance torque against an externally applied force applied to the second shaft member (4) is installed between the first shaft member (3) and the second shaft member (4) so that the amplitude of the second shaft member (4) is suppressed minutely.

Description

Technical Specification

The present invention relates to a tensioner for keeping the tension of an endless belt chain constant. Background art

For example, the tensioner pushes a timing chain used in an automobile engine or a timing belt with a predetermined force, and acts to keep the tension constant when these elongate or loosen.

FIG. 13 shows a state in which the cushion 100 is mounted on the engine body 200 of the automobile. Inside the engine body 200, a pair of force sprockets 210, 210 and a crank sprocket 220 are arranged, and these sprockets 210, 210, 220 are arranged. In between, the timing chain 230 is extended endlessly. A chain guide 240 is swingably disposed on the movement path of the timing chain 230, and the timing chain 230 slides on the chain guide 240. I have. The engine body 200 has a mounting surface 250 formed thereon, and the tensioner 100 is formed on the mounting surface 250 by a port 270 that passes through the mounting hole 260 of the mounting surface 250. Fixed. The engine body 200 is filled with lubricating oil (not shown).

Figs. 14 and 15 show a tensioner 100 conventionally used, and a rotating shaft 120 and a propulsion shaft 130 are assembled and arranged inside a case 110. Has been done. The case 110 includes a main body 111 extending in the axial direction to insert the shafts 120, 130, and a flange 1 extending from the main body 111 in a direction intersecting the axial direction. 1 and 2. The flange portion 112 is for attaching the tensioner 100 to the engine body 200. Therefore, the flange portion 112 is attached to the engine body 200. Mounting holes 113 are formed to allow a port to be screwed through. The main body 111 accommodates each of the components described below. For this reason, a housing hole 114 having the same diameter is formed in the inside along the axial direction.

The assembling of the rotating shaft 120 and the propulsion shaft 130 forms an external thread portion 121 on the outer surface of the rotating shaft 120, while forming an internal thread portion 131 on the inner surface of the propulsion shaft 130, It is performed by screwing these threaded portions 1 2 1 and 1 3 1. Inside the case 110 corresponding to the proximal end of the rotating shaft 120, a receiving seat 140 is provided so as to be located in the storage hole 114. The end of the tomb of the rotating shaft 120 is supported by 140. In the assembled state, the propulsion shaft 130 is screwed into the front half of the rotary shaft 120 and the rear half where the propulsion shaft 130 is not screwed. 150 are arranged.

The torsion spring 150 has one end hook portion 151 inserted into a slit 123 formed in the base end of the rotating shaft 120 and locked, and the other end hook portion 152 is a case. Locked at 110. Therefore, when the torsion spring 150 is twisted to assemble with a predetermined torque applied, the rotating shaft 120 is rotated by the urging force of the torsion spring 150.

A bearing 160 is fixed to a tip portion of the case 110 by a retaining ring 170, and the propulsion shaft 130 passes through a sliding hole 161 of the bearing 16. The inner surface of the sliding hole 161 of the bearing 160 and the outer surface of the propulsion shaft 130 are formed in a substantially oval shape, parallel cut, or other non-circular shape, so that the propulsion shaft 130 rotates. It is in a restrained state. The bearing 160 is formed in a flat plate shape having a predetermined thickness, and a plurality of fixing pieces 162 are formed on the outer peripheral side. The fixed piece 162 fits into the notch groove 115 formed at the tip of the case 110, so that the entire bearing 160 is in a state where rotation is stopped. In this way, the rotation of the bearing 160 with respect to the case 110 is stopped, and the rotation is restricted to the case 110 via the propulsion shaft 130 through the bearing 160 through the bearing 160. Therefore, in this rotation restricted state, the propulsion shaft 130 moves back and forth with respect to the case 110.

At the tip of the propulsion shaft 130, a cap 180 is attached. 180 is in contact with the above-described chain guide 240 in the engine body 200 described above.

Further, inside the case 110, a spacer 190 is arranged. The spacer 190 has a cylindrical shape extending in the axial direction (propulsion direction) so as to surround the rotary shaft 120 and the propulsion shaft 130, and the shaft 1 2 in a screwed state is formed. 0, 130 are prevented from falling out of the tip of the case 110. In order to prevent the falling off, the rotating shaft 120 is formed in a flanged shape that can abut against the spacer 190.

In the tensioner 100 having the above structure, the rotating shaft 120 is rotated by the urging force of the torsion spring 150, and this rotational force is converted into the propulsive force of the propulsion shaft 130. 130 will advance. Thus, the propulsion shaft 130 presses the timing chain 230 through the cap 180 and the chain guide 240, and thus tension can be applied to the timing chain 230.

In such a tensioner, it is necessary to strongly press the chain guide 240 in order to stabilize the operation by suppressing the pushing amount (amplitude) of the propulsion shaft 130 against the external input load from the chain guide 240. . For this purpose, (1) increase the spring torque of the torsion spring 150, (2) the male screw part 1 2 1 and the female screw part 1 3 1 that screw the rotary shaft 120 and the propulsion shaft 130 together. To reduce the lead angle of the shaft (for example, from 12 ° to 9 °). ③ Increase the diameter of the end face of the rotating shaft 120 and the rotating shaft 120 and the receiving seat 140 (case 110). ), Etc., the contact area is increased.

However, with these corresponding structures, the propulsion (forward) characteristic of the propulsion shaft 130 tends to be stronger. If the propulsion shaft 130 protrudes more than necessary, the friction between the chain guide 240 and the chain 230 increases, which causes a large engine output loss. .

On the other hand, in Japanese Patent Application Laid-Open No. 2000-210102, a friction plate is provided on a case, and a flange-shaped friction surface having a large contact diameter is provided on a portion of the rotary shaft facing the friction plate. Further, a structure is disclosed in which a friction surface is held by an auxiliary spring so as not to contact a friction plate. With this structure, when the external input load from the chain guide is small, the friction surface contacts the friction plate. It does not touch, but when the external input load exceeds a certain level, the friction surface can contact the friction plate and generate frictional force. This eliminates the need for the above-mentioned structures (1) to (3), thereby reducing the output loss of the engine and suppressing the amplitude of the propulsion shaft against a large external input load.

The structure of Japanese Patent Laid-Open Publication No. 2001-21012 also makes it possible to suppress the amplitude of the propulsion shaft, but depending on the engine model, the characteristic that focuses on the suppression of the amplitude may be reduced. May be required.

The present invention has been made to meet such a demand, and an object of the present invention is to provide a tensioner capable of performing fine amplitude suppression with respect to external input weight. Disclosure of the invention

In order to achieve the above object, a tensioner according to the first aspect of the present invention includes a first shaft member and a second shaft member screwed by a screw portion, and the first shaft member being rotated in one direction. A biasing torsion spring housed in the case, the tensioner for restricting rotation of the second shaft member and converting the rotational urging force of the torsion spring into a propulsion force of the second shaft member; An elastic member for generating a resistance torque against an external input load input to the first shaft member is disposed between the first shaft member and the second shaft member. According to the first aspect of the present invention, when an external input load is input to the second shaft member, the load acts on the elastic member disposed between the first shaft member and the second shaft member. . Thus, the elastic member generates a resistance torque against an external input load, so that the amplitude of the second shaft member can be reduced.

According to the first aspect of the present invention, the elastic member is disposed between the first shaft member and the second shaft member. Always generate resistive torque. Therefore, regardless of the magnitude of the external input load, since the resistance torque is generated to control the amplitude of the second shaft member, fine amplitude suppression can be performed.

Also, by increasing the spring torque of the torsion spring or reducing the lead angle of the threaded part, etc. Therefore, it is not necessary to increase the propulsive force of the second shaft member. For this reason, the friction between the chain guide and the chain does not increase, and the output loss of the engine can be reduced.

The invention according to claim 2 is the tensioner according to claim 1, wherein the elastic member is compressed by the first shaft member and the second shaft member. And a coil spring that is compressed by an external input load to generate a friction torque with the first shaft member.

In the second aspect of the present invention, the elastic member is formed by a coil spring. The coil spring is compressed by the first shaft member and the second shaft member, and is also compressed by an external load applied to the second shaft member. Compressed. By this compression, a friction torque is generated between the first shaft member and the generated friction torque is increased, so that the rotation of the first shaft member is restricted. That is, when the external input load is input, the second shaft member is pushed into the case, so that the first shaft member rotates in the direction opposite to the rotational biasing direction of the torsion spring. On the other hand, a braking force due to the frictional force of the compression spring acts. For this reason, the pushing amount (amplitude) of the second shaft member is suppressed.

Also in the invention of claim 2, since the coil spring compressed by the external input load is disposed between the first shaft member and the second shaft member, there is an input of the external input load. Since the coil spring always generates a friction torque to suppress the rotation of the first shaft member, fine amplitude suppression of the second shaft member can be performed.

The invention according to claim 3 is the tensioner according to claim 1, wherein the elastic member is twisted by an external load applied to a second shaft member. And a coil spring that generates a reaction torque in the same direction as the rotational urging direction.

According to the third aspect of the present invention, when an external input load is input to the second shaft member, the coil spring is twisted to generate a reaction torque or increase the reaction torque. Because of this, On the other hand, the pushing force on the second shaft member due to the external input load is small, and the pushing amount (amplitude) of the second shaft member can be suppressed.

Also in the invention of claim 3, since the coil spring that is twisted by the external input load and generates a reaction torque is disposed between the first shaft member and the second shaft member, Fine amplitude suppression of the second shaft member according to the input of the input load can be performed.

The invention according to claim 4 is the cushioning device according to claim 2, wherein a support seat for supporting the coil spring on either the first shaft member or the second shaft member. It is characterized by being provided.

Since the coil spring is supported by the support seat provided on the shaft member in this manner, the connection between the coil spring and the shaft member is stabilized. For this reason, even if the first shaft member repeats reciprocating rotation, the operation can be satisfactorily performed, and stable operation can be ensured.

The invention according to claim 5 is the tensioner according to any one of claims 2 to 4, wherein the coil spring has an end on the first shaft member side that is the second shaft member. The diameter is gradually reduced in a direction opposite to the direction in which the shaft member is propelled.

In the invention set forth in claim 5, since the end portion on the first shaft member side has a smaller diameter, the first shaft member slides positively with the first shaft member. For this reason, the friction torque between the first shaft member and the first shaft member can be increased, whereby the amplitude of the second shaft member can be suppressed.

The invention according to claim 6 is the tensioner according to claims 2 to 5, wherein the coil winding direction of the coil spring is opposite to the thread cutting direction of the threaded portion of the first shaft member. It is characterized by the fact that

By setting the coil winding direction opposite to the thread cutting direction of the first shaft member in this way, when the second shaft member is pushed in by the external input load and the first shaft member rotates, the coil spring is The coil diameter is twisted in the direction of winding. For this reason, the coil spring Can be smoothly operated without interfering with surrounding parts such as a case. The invention set forth in claim 5 is the cushioning device according to any one of claims 2 to 6, wherein the clutch portion that rotates as the second shaft member advances and retreats includes a clutch. The coil spring is characterized in that one end of the coil spring is locked to the clutch portion and the other end is locked to the first shaft member.

According to the seventh aspect of the present invention, the clutch portion formed on the second shaft member twists the coil spring, so that a reaction torque is generated in the coil spring. For this reason, the amplitude of the second shaft member can be suppressed.

The invention according to claim 8 is the tensioner according to claim 1, wherein the elastic member is arranged in contact with the first shaft member and the second shaft member, It is a disc spring, a rubber molded body or a resin molded body that generates a friction torque with the first shaft member by being compressed by a force load.

In the invention of claim 8, a disc spring, a rubber molded body or a resin molded body is used as the elastic member. These disc springs, rubber molded bodies and resin molded bodies are all deformed when an external input load is applied to the second shaft member, and generate friction torque with the first shaft member. . For this reason, the rotation of the first shaft member is restricted, so that the amplitude of the second shaft member can be suppressed.

Also in the invention of claim 8, since the disc spring, the rubber molded body or the resin molded body is disposed between the first shaft member and the second shaft member, the input of the external input load is reduced. In this case, a friction torque is always generated, so that the amplitude of the second shaft member can be finely controlled.

The invention according to claim 9 is the cushioning device according to any one of claims 1 to 8, wherein a buffer plate is provided between the elastic member and the first shaft member. It is characterized by being inserted.

The cushioning plate inserted between the elastic member and the first shaft member acts to prevent the elastic member from biting into the first shaft member. For this reason, the elastic member operates smoothly. And the wear of the elastic member and the first shaft member can be suppressed, and the durability can be improved. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a plan view showing a tensioner according to Embodiment 1 of the present invention, FIG. 2 is a cross-sectional view taken along line C--C in FIG. 1, and FIG. FIG.

(a) shows the conventional tensioner, (b) shows the tensioner of the first embodiment, FIG. 4 is a sectional view showing the tensioner of the second embodiment, and FIG. FIG. 6 is a partial cross-sectional view showing a modification of the second embodiment, FIG. 6 is a partial cross-sectional view showing another modification of the second embodiment, and FIG. 7 is a tensioner of the third embodiment. FIG. 8 is a cross-sectional view illustrating a tensioner according to a fourth embodiment, FIG. 9 is a cross-sectional view illustrating a tensioner according to a fifth embodiment, and FIG. 11 is a sectional view showing a tensioner according to a sixth embodiment, FIG. 11 is a sectional view showing a tensioner according to a seventh embodiment, and FIG. 12 is a sectional view showing a tensioner according to an eighth embodiment. FIG. 13 is a sectional view showing a state in which the tensioner is mounted on the engine body, and FIG. FIG. 1 is a plan view showing a conventional cushioner. FIG. 15 is a cross-sectional view taken along line QQ in FIG. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be specifically described with reference to the illustrated embodiments. In each embodiment, the same members are denoted by the same reference numerals and correspond to each other.

(Embodiment 1)

1 to 3 show a tensioner A1 according to a first embodiment of the present invention. A case 2, a first shaft member 3, a second shaft member 4, a grip spring 5, a bearing 6, and a shaft It has 7 sensors.

Case 2 has a substantially T-shaped cross section in which a flange portion 2b extends in a substantially orthogonal direction from a tip of a body portion 2a. Then, from the trunk 2a to the part where the flange 2 is formed, The receiving hole 2c is formed to extend in the same direction. The tip of the storage hole 2c is open, and the assembly of the first and second shaft members 3, 4, the torsion spring 5, and the spacer 7 is stored in the storage hole 2c. You.

The flange portion 2b of the case 2 is for mounting to an engine body, which is a device to be used, and has a mounting hole 2d through which a port (not shown) screwed to the engine body penetrates. At the time of attachment to the engine body, the tip surface of the flange portion 2b comes into contact with the attachment surface 250 of the engine body 200, as in FIG.

The first shaft member 3 is rotated by being urged by a torsion spring 5 described later, and the second shaft member 4 is propelled from the case 2 by the rotation of the first shaft member 3. The first shaft member 3 has a shaft portion 3a on the proximal end side and a screw portion 3b on the distal end side integrally formed in the axial direction, and an outer periphery of the screw portion 3b on the distal end side has An external thread 8 is formed. In addition, the base end of the shaft portion 3a comes into contact with a receiving seat 19 provided in the case 2, whereby the rotation thereof is supported. Further, a slit 3e into which a distal end of a fastening jig (not shown) for rotating the first shaft 3 is inserted is formed in the base end surface of the shaft portion 3a. The slit 3 e communicates with the jig hole 2 e formed in the base end face of the body 2 a of the case 2. By rotating the first shaft member 3 via e, a torsion spring 5 described later can be wound and tightened.

The second shaft member 4 is formed in a cylindrical shape, and on the inner surface thereof, a female screw 9 with which the male screw 8 of the first shaft member 3 is screwed is formed. These shaft members 3 and 4 are inserted into the storage hole 2 c of the case 2 with the female screw 9 and the male screw 8 screwed together. A cap 10 is attached to the tip of the second shaft member 4. The cap 10 is composed of a head 10 Oa and a leg 1 Ob, the head 10 a covers a tip portion of the second shaft member 4, and the leg 10 b is attached to the second shaft member 4. The spring pins 11 are press-fitted into these in a state where they are fitted to the distal end portions thereof, and are prevented from coming off and fixed to the second shaft member 4. The torsion spring 5 is extrapolated to the shaft portion 3a of the first shaft member 3. This twist The hook 5a at one end of the hook 5 is inserted and locked in a hook groove 2f formed in the case 2, while the hook 5b at the other end is connected to the first shaft member 3 and the slit 3 at the bottom. Inserted and locked in e. Therefore, the first shaft member 3 can be rotated by tightening the torsion spring 5 and applying a torque.

The bearing 6 is attached to the tip of the case 2 and is fixed by a retaining ring 13. The bearing 6 has a sliding hole 6a, and the second shaft member 4 passes through the sliding hole 6a. The inner surface of the sliding hole 6a of the bearing 6 and the outer surface of the second shaft member 4 are formed in a substantially oval shape, a D-cut ゃ parallel cut, and other non-circular shapes. The member 4 is in a state where the rotation is restricted.

The bearing 6 is formed in a flat plate shape having a predetermined thickness, and a plurality of fixing pieces 613 are radially formed on the outer peripheral side. When the fixing piece 6b is fitted into the notch groove 2g formed in the front end portion of the case 2, the entire bearing 6 is in a state where rotation is stopped. When the bearing 6 is stopped from rotating with respect to the case 2 in this manner, the second shaft member 4 that has penetrated the bearing 6 is restrained from rotating by the case 2 via the bearing 6.

The first shaft member 3 is screwed to the second shaft member 42 via the threaded portions 8 and 9, and the rotational force of the first shaft member 3 rotated by the rotational urging force of the torsion spring 5. Is transmitted to the second shaft member 4. Since the second shaft member 4 is rotationally constrained by the bearing 6, the second shaft member 4 advances and retreats with respect to the case 2.

The spacer 7 has a cylindrical shape, and a threaded portion of the first shaft member 3 and the second shaft member 4 is inserted therein. In this case, a large-diameter flange portion 3c is formed at a boundary portion between the shaft portion 3a and the thread portion 3b in the first shaft member 3, and the spacer 7 has a base end portion. It is in contact with the flange 3c. The distal end of the spacer 7 faces the bearing 6, and the contact with the bearing 6 prevents the first and second shaft members 13, 14 from coming out of the case 2.

In addition to the above, in this embodiment, a coil spring 20 as an elastic member is provided. The coil spring 20 is disposed between the first shaft member 3 and the second shaft member 4. I have. In this embodiment, the coil spring 20 is disposed between the threaded portion 3 of the first shaft member 3 and the base end of the second shaft member 4.

Further, as the coil spring 20, a compression spring having hook portions at both ends being free ends is used. One end 20 a of the coil spring 20 made of a compression spring is in contact with the second shaft member 4, while the other end 20 b is in contact with the first shaft member 3. In this case, the other end portion 20 b comes into contact with the flange portion 3 c of the first shaft member 3. Such a coil spring 20 is assembled in a state where both end portions 20a and 20b are in contact with both shaft members 3 and 4 and are compressed to some extent.

Therefore, when an external input load that pushes the second shaft member 4 is input, a compressive force is applied directly to the coil spring 20 in which the distal end portion 20a is in contact with the second shaft member 4, and the coil spring Hey 20 is compressed. Since the other end 20 b of the coil spring 20 is in contact with the first shaft member 3, the compression of the coil spring 20 causes a friction torque between the coil spring 20 and the first shaft member 3. Occurs or the friction torque already generated further increases. Thereby, a braking force acts on the first shaft member 3, and the rotation of the first shaft member 3 is restricted.

FIG. 3 explains the operation of this embodiment in comparison with the conventional tensioner shown in FIGS. 14 and 15, and the conventional tensioner has the same reference numerals as those in FIG. Is added to the corresponding. As shown in the figure, a rotational urging force composed of a torque T acts on the first shaft member 3 by a torsion spring 5. When the external input load F is input, the second shaft 4 is pushed into the case 2, so that the first shaft member 3 rotates in the direction of arrow D against the rotational urging force of the torsion spring 5.

The tensioner without the coil spring 20 rotates in the direction of arrow D with a rotation torque Tk corresponding to the load of the external input load F, as shown in FIG. In this case, the rotation angle of the first shaft member 3 is 0 2, and the amplitude of the second shaft member 4 corresponding to the angle Θ2 is B.

On the other hand, in this embodiment, as shown in FIG. A coil spring 20 composed of a compression spring is disposed between the second shaft member 4 and the coil spring 20 when the external input load F is input to the second shaft member 4. A friction torque is generated between the lower end portion 20b and the flange portion 3c of the first shaft member 3, or the friction torque is larger than the friction torque already generated.

This friction torque T 1 is obtained by multiplying the axial load W of the coil spring 20, the contact radius r of the first shaft member 3, and the coefficient of friction between the first shaft member 3 (T Ί = r 'μ). The friction torque Τ1 exerts a braking action on the rotation angle 02 at which the first shaft member 3 is forcibly rotated by the pushing of the second shaft member 4. For this reason, the rotation angle of the first shaft member is reduced from 0 ° to Θ1, and the pushing amount (amplitude) Β1 of the second shaft member 4 can be reduced.

In such an embodiment, the coil spring 20 is disposed between the first shaft member 3 and the second shaft member 4 so that when an external input load F is input, the coil spring 2 0 must be compressed to generate friction torque or increase. Therefore, regardless of the magnitude of the external input load F, the amplitude of the first shaft member 3 can be suppressed, so that fine amplitude suppression can be performed.

Further, it is not necessary to increase the spring torque of the torsion spring 5 or to reduce the lead angle of the threaded portions 8 and 9 to increase the propulsive force of the second shaft member 4 to suppress the amplitude. For this reason, the friction between the chain guide and the chain does not become large, and the output loss of the engine can be reduced.

(Embodiment 2)

FIG. 4 shows a tensioner 1 according to a second embodiment of the present invention, in which a buffer plate 22 is inserted between a coil spring 20 composed of a compression spring and a flange portion 3c of the first shaft member 3. Have been. The buffer plate 22 is made of a thin metal plate such as a washer, and is provided so as to be sandwiched between the other end portion 20 b of the coil spring 20 and the flange portion 3 c of the first shaft member 3.

By providing such a buffer plate 22, it is possible to prevent the other end portion 20 b of the coil spring 20 from biting into the first shaft member 3. This makes the coil spring 20 circle Smooth operation can be performed, wear of the coil spring 20 and the first shaft member 3 can be suppressed, and durability can be achieved.

FIG. 5 and FIG. 6 show variations of this embodiment. In the embodiment shown in FIG. 5, between the flange portion 3c of the first shaft member 3 and the other end portion 20b of the coil spring 20, a metal washer 23 such as iron or stainless steel and a PTFE ( A buffer plate 22 made of a laminate of a resin washer 24 such as poly (tetrafluoroethylene) and the above-mentioned metal washer 25 is inserted. A buffer plate made of a metal washer 26 is inserted between one end 20 a of the coil spring 20 and the second shaft member 4.

In the embodiment shown in FIG. 6, a solid lubricant 27 such as PTFE is coated on the outer surface of the wire of the coil spring 20. Further, between both end portions of the coil spring 20 and the flange portion 3c of the first shaft member 3 and the second shaft member 4, a buffer plate made of a metal washer 23 and a metal washer 26 is inserted. ing.

By inserting such various cushioning plates between the coil spring 20 and the first shaft member 3 and the or the second shaft member 4, or by coating the coil spring 20 with a solid lubricant. The coefficient of friction between the coil spring 20 and the first shaft member 3 and / or the second or fourth shaft member 4 can be arbitrarily adjusted. This makes it possible to easily obtain the desired friction torque.

(Embodiment 3)

FIG. 7 shows A3 of the third embodiment of the present invention. In the tensioner A3 of this embodiment, both ends 20a and 20b of a coil spring 20 composed of a compression spring are supported by the first shaft member 3 and the second shaft member 4.

That is, a stepped portion 3 g having an outer diameter corresponding to the inner diameter of the coil spring 20 is formed between the flange portion 3 c and the screw portion 3 b of the first shaft member 3, while the second shaft member 4 A step 4 g having an outer diameter corresponding to the inner diameter of the coil spring 20 is formed at the end of the first shaft member 3 side. These steps 3 g and 4 g serve as support seats for supporting the ends of the coil spring 20. Then, these steps 3 g and 4 g are applied to both ends 20 a and 20 b of the coil spring 20. By inserting it, a more stable support state is achieved. Note that a metal washer 22 as a buffer plate is sandwiched between the other end 2 Ob of the coil spring 20 and the flange 3 c of the first shaft member 3. Also in this embodiment, the coil spring 20 is in a compressed state to some extent.

Since both ends of the coil spring 20 are supported by the first and second shaft members 3 and 4 in this manner, even if the first shaft member 3 repeats reciprocating rotation, it smoothly responds to its operation. As a result, stable operation can be performed. The end of the coil spring 20 can be stably supported if it is one of the shaft members 3 and 4.

(Embodiment 4)

FIG. 8 shows a tensioner A4 according to Embodiment 4 of the present invention. Also in this embodiment, both ends 20a and 20b of the coil spring 20 are attached to both shaft members 3 and 4, similarly to the tensioner A3 of the third embodiment shown in FIG. Supported. Therefore, it is possible to smoothly respond to the reciprocating rotation of the first shaft member 3. In addition, in the present embodiment, the coil diameter of the coil portion of the coil spring 20 located on the first shaft member 3 side is reduced. That is, the diameter of the coil spring 20 gradually decreases at the end on the first shaft member side in the direction opposite to the direction in which the second shaft member 4 is propelled. Then, the gradually reduced other end 2 Ob is supported by the step 3 g of the first shaft member. With such a small diameter, the coil spring 20 and the first shaft member 3 can slide positively, and the friction torque between them can be increased. However, the amplitude of the second shaft member 4 can be suppressed. In addition, since the coil diameter of the coil spring 20 is large on the side of the second shaft member 4, the friction torque generated from the coil spring 20 can be increased. Rotation angle of member 3 Can be smaller. Thereby, the amplitude of the second shaft member 4 can be reduced. It should be noted that the rate of change of the diameter of the end of the coil spring 20 can be arbitrarily changed, whereby the reaction torque can be arbitrarily adjusted.

(Embodiment 5)

FIG. 9 shows a tensioner A5 according to Embodiment 5 of the present invention. Also in this embodiment, the elastic member 30 is disposed between the first shaft member 3 and the second shaft member 4, but the elastic member 30 is formed of a cylindrical resin molded body. I have. As the resin molded body, a hard filler mixed resin or the like can be used.

The elastic member 30 made of a resin molded body is disposed so as to be sandwiched between the first shaft member 3 and the second shaft member 4, so that the elastic member 30 can receive an external input load to the second shaft member 4. Compressed. This compression generates a friction torque with the first shaft member 3 or increases the generated friction torque. Therefore, a braking force acts on the first shaft member 3 and the amplitude of the second shaft member 4 can be suppressed. However, a rubber molded body such as a synthetic rubber can be used instead of the resin molded body.

(Embodiment 6)

FIG. 10 shows a first embodiment A6 of the sixth embodiment of the present invention. In this embodiment, the elastic member 31 disposed between the first shaft member 3 and the second shaft member 4 is formed of a laminate of disc springs.

The elastic member 31 made of a laminate of disc springs is compressed by an external input load to the second shaft member 4 by being sandwiched between the first shaft member 3 and the second shaft member 4. Therefore, friction torque is generated between the first shaft member 3 and the generated friction torque is increased. Also, between the stacked disc springs, a braking force << is generated due to friction. Accordingly, a braking force acts on the first shaft member 3 by these, and the amplitude of the second shaft member 4 can be suppressed.

(Embodiment 7)

FIG. 11 shows a tensioner A7 according to a seventh embodiment of the present invention. In this embodiment, the main body 41 has the second shaft member 4 located on the engine body side, and the clutch 42 has the second shaft member 4 located on the first shaft member 3 side of the body 41. It is configured. The main body 41 and the clutch part 42 are propelled from Case 2. Further, the clutch part 42 and the main body part 41 are engaged with each other by forming a locking claw 43 having an isosceles triangle shape.

On the other hand, a hook portion 33 a at one end of a coil spring 33 as an elastic member is locked to the clutch portion 42. The coil spring 33 is externally inserted into the screw portion 3 b of the first shaft member 3, and the hook portion 33 b at the other end is engaged with the flange portion 3 c of the first shaft member 3. In this embodiment, the coil spring 33 is disposed between the first shaft member 3 and the second shaft member 4 in a compressed state, and is connected via hook portions 33 a and 33 b at both ends. It is engaged with both shaft members 3 and 4 in a twisted state. Thereby, the coil spring 33 has a reaction torque against the external input load.

In such an embodiment, when an external input load is applied to the second shaft member 4, the reaction torque of the coil spring 33 increases according to the angle and height of the locking claw 43. For this reason, in this embodiment, since the braking is performed by the torque of the torsion spring 5 and the reaction torque of the coil spring 33 in response to the external input load, the amplitude of the second shaft member 4 is finely suppressed. can do.

(Embodiment 8)

FIG. 12 shows a cushion A 8 according to an eighth embodiment of the present invention. Also in this embodiment, similarly to the tensioner A 7 of the seventh embodiment, the second shaft member 4 is formed by the main body portion 41 on the distal end side and the clutch portion 42 on the first shaft member 3 side. In addition, a locking claw 43 is formed between them. Further, the coil spring 33 is disposed between the first shaft member 3 and the second shaft member 4, and the hook portion 33a at one end is engaged with the clutch portion 42, and the hook portion at the other end. 33 b is locked to the flange portion 3 c of the first shaft member 3.

In this embodiment, the locking claw 43 is formed in a saw-tooth shape, and this The reverse rotation of 2 is not possible. Therefore, after the second shaft member 4 is once propelled, the clutch portion 42 does not rotate in the reverse direction, and the reaction torque by the coil spring 33 can be increased.

(Embodiment 9)

Although not shown in this embodiment, in Embodiments 1 to 8, the coil winding direction of the coil spring is opposite to the thread cutting direction of the external thread portion 8 of the first shaft member 3. Thus, when the first shaft member 3 is rotated by the second shaft member 4 being pushed by the external input load, the coil spring is twisted in a direction in which the coil diameter is tightened. Therefore, the coil diameter does not increase, interference with surrounding components can be prevented, and operation becomes smooth. Industrial applicability

According to the first aspect of the present invention, the elastic member is disposed between the first shaft member and the second shaft member. Since the resistance torque is generated, it is possible to finely suppress the amplitude of the second shaft member. Further, since the friction between the chain guide and the chain does not increase, the output loss of the engine can be reduced.

According to the second aspect of the present invention, in addition to having the same effect as the first aspect of the present invention, a coil disposed between the first shaft member and the second shaft member Since the compression of the spring generates a friction torque to suppress the rotation of the first shaft member, fine amplitude suppression of the second shaft member can be performed.

According to the third aspect of the invention, in addition to having the same effects as the first aspect of the invention, a coil disposed between the first shaft member and the second shaft member Since the spring is twisted to generate a reaction torque, it is possible to perform fine amplitude suppression and large amplitude suppression on the second shaft member according to the input of the external input load.

According to the invention set forth in claim 4, in addition to the effect of the invention set forth in claim 2, the first system is provided. Since the support seat for supporting the coil spring is provided on either the shaft member or the second shaft member, even if the first shaft member repeats reciprocating rotation, it can respond to the operation well, Stable operation can be ensured.

According to the fifth aspect of the invention, in addition to having the effects of the second to fourth aspects of the invention, it is possible to increase the friction torque with the first shaft member. In addition, the amplitude of the second shaft member can be suppressed. Also, an arbitrary friction torque can be set depending on the spring shape.

According to the invention set forth in claim 6, in addition to having the effects of the inventions set forth in claims 2 to 5, the coil winding direction is opposite to the thread cutting direction of the first shaft member. Accordingly, the coil spring does not have a large coil diameter and does not interfere with surrounding parts such as a case, and thus the operation can be performed smoothly.

According to the invention set forth in claim 7, in addition to having the effects of the inventions set forth in claims 2 to 6, the clutch portion formed on the second shaft member twists the coil spring. However, a reaction torque is generated in the coil spring, and the amplitude of the second shaft member can be suppressed.

According to the invention of claim 8, in addition to having the effect of the invention of claim 1, the disc spring, the rubber molded body and the resin molded body are compressed to form the first shaft member and Since a friction torque is generated between the first shaft member and the second shaft member, the amplitude of the second shaft member can be suppressed.

According to the ninth aspect of the present invention, in addition to having the effects of the inventions of the first to eighth aspects, the fact that the three simple members bit into the first shaft member is prevented by the buffer plate. In order to prevent this, smooth operation of the elastic member can be performed, wear of the elastic member and the first shaft member can be suppressed, and durability can be improved.

Claims

The scope of the claims

1. A first shaft member and a second shaft member screwed together by a screw portion, and a torsion spring for urging the first shaft member to rotate in one direction are accommodated in a case. A tensioner for restricting rotation of a shaft member and converting the rotational urging force of a torsion spring into a propulsion force of a second shaft member,

An elastic member for generating a resistance torque against an external input load input to a second shaft member. A tensioner disposed between the first shaft member and the second shaft member.

2. The elastic member is disposed between the first shaft member and the second shaft member in a compressed state, and is compressed by an external input load. 2. The cushioning spring according to claim 1, wherein the spring is a coil spring that generates a friction torque with the shaft member.

3. The elastic member is a coil spring that generates a reaction torque in the same direction as the rotational biasing direction of the torsion spring by being twisted by an external input load to the second shaft member. The tensioner according to claim 1.

4. The tensioner according to claim 2, wherein a support seat for supporting the coil spring is provided on either the first shaft member or the second shaft member.

5. The coil spring according to claim 2, wherein the end of the first shaft member on the side of the first shaft member has a diameter gradually reduced in a direction opposite to a propulsion direction of the second shaft member. A tensioner according to any of the preceding clauses.

6. The tensioner according to any one of claims 2 to 5, wherein a coil winding direction of the coil spring is opposite to a thread cutting direction of a threaded portion of the first shaft member. . (F) a clutch portion that rotates as the second shaft member advances and retreats is formed on the second shaft member; one end of the coil spring is locked to the clutch portion, and the other end is the first shaft member. The tensioner according to any one of claims 2 to 6, wherein the tensioner is locked to the tensioner.

8. The elastic member is arranged in contact with the first shaft member and the second shaft member, and generates a friction torque with the first shaft member by being compressed by an external input load. The tensioner according to claim 1, wherein the tensioner is a disc spring, a rubber molding rest, or a resin molding.

9. The tensioner according to any one of claims 1 to 7, wherein a buffer plate is inserted between the elastic member and the first shaft member.