JP2001304359A - Tensioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To wind up a tooth circle, allowing rotatory operation from a different direction from the rear end part of a first shaft member. SOLUTION: A rotatable first shaft member 11, a second shaft member 12 screwed with the first shaft member 11 and axially moved in a rotation restrained state, and a spring 13 tightened by the rotation of the first shaft member 11 in one direction for energizing the first shaft member 11 to rotate in the other direction, are stored in a case 14. An engaging part 21, with which an operating member 25 for rotating the first shaft member 11 is engaged, is formed at the first shaft member 11, and an operation aperture 15 enabling insertion of the operating member 25 is opened at the side face of the case 14 on which the engaging part 21 faces.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw type tensioner for maintaining a constant tension of an endless belt, a chain or the like.

[0002]

2. Description of the Related Art A tensioner is used when an endless belt or a chain, for example, a timing belt or a timing chain of an automobile or the like is stretched or worn during use.
When the tension becomes loose, it is used to press them in a certain direction to apply a certain tension.

FIG. 12 shows a tensioner conventionally used. First and second shaft members 110 and 120 are assembled and inserted into case 100. The case 100 is attached to the engine body, and therefore, the flange portion 130 in which the attachment hole 131 is formed extends outward.

[0004] First and second shaft members 110 and 12
No. 0 forms the external thread portion 111 on the outer peripheral surface of the first shaft member 110, while the second shaft member 1
This is performed by forming a female screw portion 121 on the inner peripheral surface of the screw 20 and screwing these screw portions 111 and 121 together.
First and second shaft members 110, 1 assembled
Reference numeral 20 denotes a rear end of the first shaft member 110 for receiving the seat 15.
By being fitted in the case 100, it is supported in the case 100.

[0005] The first shaft member 110 is inserted into the case 100 so as to rotate. This rotation is performed by the rotation urging force of the torsion spring 160. Torsion spring 1
60 has one end locked to the slit 112 on the rear end surface of the first shaft member 110 and the other end locked to the case 100, and is assembled with the torsion spring 160 tightened to apply a predetermined torque. Then, the first shaft member 110 is rotated by the rotational urging force of the torsion spring 160.

The second shaft member 120 has a cylindrical shape, and has a bearing 140 fixed to a distal end portion of the case 100.
, The tip portion protrudes outside the case 100. The through hole of the bearing 140 through which the second shaft member 120 penetrates is a non-circular shape such as a substantially oval shape, and the outer shape of the second shaft member 120 is formed in the same shape as the non-circular through hole. . Therefore, the rotation of the second shaft member 120 is restricted.

In such a structure, even if the first shaft member 110 is rotated by the action of the rotational urging force of the torsion spring 160, the second shaft screwed to the first shaft member 110.
Shaft member 120 does not rotate. For this reason, the rotation urging force of the torsion spring 160 is converted into the propulsion force of the second shaft member 120 via the rotation of the first shaft member 110, and the second shaft member 120 advances.
Thereby, since the second shaft member 120 presses the timing belt or the timing chain, a constant tension can be applied to these.

The tightening of the torsion spring 160 for urging the first shaft member 110 to rotate is performed by the first shaft member 11.
0 is performed. Therefore, the first shaft member 1
An opening 1 is provided at the rear end of the case 100 facing the rear end surface of the case 10.
05 is formed. Then, the rotation lock member 190 is inserted into the opening 105, and the tip of the rotation lock member 190 is engaged with the slit 112 of the first shaft member 110 and rotated, whereby the torsion spring 160 is tightened.

After the tightening, the rotation lock member 190 is mounted on the engine body while being inserted, the rotation lock member 190 is removed, and the tension state of the timing belt and the timing chain is adjusted.

[0010] Maintenance of the engine and the tensioner is performed in a state where the tension applied to the timing chain and the timing belt is released. in this case,
The rotation lock member 1 described above in a state of being mounted on the engine body.
An operating member 90 or a driver is inserted into the opening 105 at the rear end of the first shaft member 110, and the first shaft member 110 is rotated. Thereby, the torsion spring 160
And the second shaft member 120 is retracted. Maintenance is performed in a state where the operation member such as the rotation lock member 190 is inserted, that is, in a state where the advancement of the second shaft member 120 is prevented, or after the tensioner is removed from the engine body.

By locking the spring force of the torsion spring 160 in this manner, the second shaft member 120 does not inadvertently press the timing chain and the timing belt, so that the teeth of the cam sprocket jump or the engine body side. Can be prevented from being damaged. After the maintenance is completed as described above, the rotation lock member 190 or the driver or the like is removed and reused with the tensioner attached to the engine body.

[0012]

However, there is a case where there is no space at the rear end side of the tensioner due to the structure of the engine body and the layout of peripheral parts of the tensioner. In such a case, in the conventional structure, the operation members such as the rotation lock member 190 and the driver cannot be inserted from the rear end of the first shaft member 110, and the torsion spring 1
60 cannot be rolled up. For this reason, there is a problem that the spring cannot be wound up, and it is not possible to prevent the tooth jump of the cam sprocket and the damage of the tensioner mounting portion of the engine body.

The present invention has been made in consideration of such conventional problems, and is intended for a case where operation from the rear end side of the tensioner is not possible due to a difference in the structure of the engine body and a relationship with peripheral parts. Even if there is, it is an object to provide a tensioner which has a structure capable of winding up a spring, and thereby, can be securely attached to and detached from an engine body.

[0014]

In order to achieve the above-mentioned object, a first aspect of the present invention is a state in which a rotatable first shaft member is screwed to the first shaft member and rotation is restricted. A second shaft member that moves in the axial direction with
A tensioner that is housed inside a case and a spring that is wound and fastened by rotation of the first shaft member in one direction and urges the first shaft member to rotate in the other direction; A rotation operation of the member from outside can be performed from a side surface of the case.

According to the present invention, even when the rotation operation cannot be performed from the rear end side of the case, the first side is provided from the side of the case.
Since the rotation operation of the shaft member can be performed, the spring can be tightened via the first shaft member. For this reason, attachment and detachment of the tensioner can be reliably performed.

According to a second aspect of the present invention, there is provided a first shaft member rotatable, a second shaft member screwed to the first shaft member and moving in the axial direction with rotation restricted. A tensioner that is housed inside a case and a spring that is wound and fastened by rotation of the first shaft member in one direction and urges the first shaft member to rotate in the other direction; An engaging portion with which the operating member for rotating the member is engaged is formed on the first shaft member, and an operation window through which the operating member can be inserted is opened on a side surface of the case facing the engaging portion. And

According to the present invention, the operation member is inserted from the operation window formed on the side surface of the case and is engaged with the engagement portion of the first shaft member. By operating the operation member in this engaged state to rotate the first shaft member, the spring can be tightened. Therefore, even when the rear end side of the case cannot be operated, the spring can be wound up, and the tensioner can be securely attached and detached.

The invention according to claim 3 is the invention according to claim 2, wherein the engagement portion comprises a plurality of engagement grooves formed on an outer periphery of the first shaft member, and the operation window is provided with the operation window. It is characterized in that it is formed so as to be longer along the rotation direction of the first shaft member.

According to the present invention, the first shaft member can be rotated by moving the operation member in the length direction of the operation window while the operation member is engaged with the engagement groove. Causes the spring to be tightened. Therefore, even if the rear end of the case cannot be operated,
The spring can be wound up, and the tensioner can be securely attached and detached.

According to a fourth aspect of the present invention, in the second aspect of the present invention, the engaging portion comprises engaging teeth formed on the entire outer surface of the first shaft member, and the operating member includes the engaging member. A gear portion in which a meshing tooth meshing with the false tooth is formed on the entire outer surface,
A shaft portion integrally formed with the gear portion and supported on an end face of the operation window.

In the present invention, the first shaft member can be rotated by rotating the operation member in a state where the engagement teeth of the operation member are meshed with the engagement teeth of the first shaft member. This rotation winds the spring. During this rotation, the shaft of the operation member is supported on the end face of the operation window, so that the operation member can be smoothly rotated. Thus, even when the rear end of the case cannot be operated, the spring can be wound up,
The attachment and detachment of the tensioner can be reliably performed.

[0022]

FIG. 1 shows a cross section of an engine body to which an embodiment of the present invention is applied. Inside the engine body 1, a crank sprocket 2 and a pair of cam sprockets 3, 3 are arranged, and an endless timing chain 4 is stretched between them. A chain guide 5 that swings about a fulcrum 7 is provided inside the engine body 1. Chain guide 5
, The timing chain 4 slides. A tensioner 10 according to an embodiment to be described later is connected to the chain guide 5, and the tension of the timing chain 4 is adjusted via the chain guide 5 by applying a pushing force from the tensioner 10 in the arrow X direction.

In this structure, the space at the rear end of the tensioner 10 is small, so that operation from the rear end of the tensioner 10 is difficult. For this reason, tensioner 1
An operation window 15 is formed on the side surface of the case 14 of the "0" so that the operation can be performed from the side surface. The second shaft member 12 of the tensioner 10 presses the chain guide 5.

Hereinafter, a tensioner according to the present invention will be described in detail with reference to an embodiment shown in the drawings. In each of the embodiments, the same elements are denoted by the same reference numerals and correspond to each other.

(Embodiment 1) FIGS. 2 to 5 show a first embodiment of a tensioner and a first shaft member 11.
, The second shaft member 12, the spring 13, and the case 1
And 4.

The case 14 includes a first shaft member 11,
The second shaft member 12 and the spring 13 are accommodated in an assembled state, and a cavity 14a for accommodating the second shaft member 12 and the spring 13 is formed in the axial direction. An opening 14 for tightening the spring 13 is provided at the rear end of the case 14.
b is formed.

The first shaft member 11 has a substantially columnar shape as a whole, and extends inside the case 14 in the axial direction. The first shaft member 11 is rotatably supported in the case 11 by receiving the rear end 11 b of the first shaft member 11 with the receiving seat 17. Also, the first shaft member 11
, A cylindrical spacer 18 is extrapolated.

The spacer 18 includes a flange 11d integrally formed on the rear end side of the first shaft member 11 and a case 11
The first shaft member 11 is restrained from moving in the axial direction by the receiving seats 17 and the bearings 19 on both sides.

The rear end 11 of the first shaft member 11
b, a slit 16 is formed, and the slit 16 faces the opening 14 b of the case 14. Therefore, the first shaft member 11 can be rotated by inserting a screwdriver or the like from the opening 14b of the case 14 and inserting it into the slit 16 and rotating it. This rotation allows the spring 13 to be described later to be tightened. Can be.

The second shaft member 12 has a cylindrical shape extending in the axial direction. A female screw portion 12a is formed on the inner peripheral surface of the second shaft member 12, and this female screw portion 12a is screwed into a male screw portion 11a formed on the outer peripheral surface of the first shaft member 11. Thereby, the second shaft member 12 is connected to the first shaft member 11.
The second shaft member 12 penetrates the bearing 19 described above, and its outer shape is a non-circular shape such as a substantially oval shape. The through-hole of the bearing 19 through which the second shaft member 12 penetrates is non-circular with the same diameter as the second shaft member 12, whereby the rotation of the second shaft member 12 is restrained, and To reciprocate. The tip of the second shaft member 12 is provided with a cap 20.
Is covered.

As the spring 13, a torsion spring having a larger diameter than the shaft cover 18 of the first shaft member 11 is used, and the first shaft member 11 and the second shaft member 12 are inserted into the coil portion. Is done. Torsion spring 13
Has one end locked to the slit 16 of the first shaft member 11 and the other end locked to the case 14, thereby urging the first shaft member 11 to rotate.

In addition to the above configuration, in this embodiment, the first shaft member 1 has an engagement hole 21 as an engagement portion.
1 is formed. The engagement hole 21 is formed in the rear end portion 11b of the first shaft member 11, and the rear end portion 11b of the first shaft member 11 is formed in a cylindrical shape, and the circumference of the rear end portion 11b is formed. A plurality is formed above at appropriate intervals. In this case, each of the engagement holes 21 is formed toward the axis of the first shaft member 11.

On the side surface of the case 14 where the engagement hole 21 faces,
The operation window 15 described above is formed. The operation window 15 has a slit shape elongated in the rotation direction of the first shaft member 11, so that an operation member 25 described later can move inside the operation window 15.

As shown in FIGS. 3 and 5, the operating member 25 has a pin shape, and when inserted into the operating window 15 of the case 14, its distal end is engaged with the first shaft member 11. It is inserted into the hole 21 and engaged.

In such an embodiment, when attaching or detaching the tensioner 10, the operating member 25 is inserted through the operating window 15 on the side surface of the case 14, and the distal end of the operating member 25 is engaged with the engaging hole 21 of the first shaft member 11. Plug in. In this state, the operation member 25 is moved in the direction of arrow R along the direction in which the torsion spring 13 is wound. At this time, the operation member 25 moves along the length direction of the operation window 15. With this move,
Since the first shaft member 11 rotates in the direction in which the torsion spring 13 is wound, the torsion spring 13 can be wound up. The second shaft member 12 is drawn into the case 14 by the winding of the torsion spring 13.

When the operation member 25 reaches the end point of the operation window 25, another operation member 25 is similarly inserted into the engagement hole 21 of the first shaft member 11, and in this inserted state, the operation member 25 is inserted. By moving along the operation window 15, the torsion spring 13 is wound up through the rotation of the first shaft member 11, and the second shaft member 12 is retracted. After the predetermined winding of the torsion spring 13 is completed by the above operation, the tensioner 10 is removed from the engine body with the operation member 25 being inserted into the engagement hole 21.

In this state, since the operating member 25 acts as a stopper, the first shaft member 11 does not rotate and the second shaft member 12 does not advance. Therefore, even when the rotation operation from the rear end side of the case 14 cannot be performed, the rotation operation of the first shaft member 11 is performed from the operation window 15 on the side surface of the case 14 by being arranged as illustrated in FIG. Therefore, the torsion spring 13 can be wound up via the first shaft member 11. For this reason, the attachment and detachment of the tensioner 10 can be reliably performed in a state where jumping of the teeth of the cam sprocket 3 and breakage of the portion where the tensioner 10 is mounted on the engine body are prevented.

(Embodiment 2) FIGS. 6 to 11 show Embodiment 2 of the tensioner 10. FIG. In this embodiment, the engaging teeth 3 are attached to the rear end 11b of the first shaft member 12.
1 are integrally formed. The engaging teeth 31 are formed all around the outer surface so as to be slightly higher than the cylindrical rear end portion 11b. Note that the spacer 18 is not extrapolated to the first shaft member 11 of this embodiment, and therefore, the movement of the first shaft member 11 in the axial direction is not restricted. It is a rotatable structure.

In this embodiment, the operating member 35
Has a structure having a gear portion 36 and a shaft portion 37 as shown in FIG. Engaging teeth 38 meshing with the engaging teeth 31 are formed around the entire outer surface of the gear portion 36. On the other hand, the shaft portion 37 is formed by integrally projecting from the center of the gear portion 36 to both left and right sides.

The operation window 15 of the case 14 of this embodiment is provided on a side surface of the case 14 facing the engagement teeth 31 of the first shaft member 11. This operation window 15
Are formed so as to be longer along the rotation direction of the first shaft member 11. The operation window 15 is provided for the operation member 3.
And the insertion hole 15a into which the gear portion 36 of the fifth
5a is formed by a bearing surface 15b that blocks the periphery of 5a.

In such an embodiment, as shown in FIGS. 10 and 11, the operating member 35 is inserted into the operating window 15 and the biting teeth 38 of the gear portion 36 are engaged with the first shaft member 11. Engage with the denture 31. At this time, the shaft portion 37 of the operation member 35 is supported in contact with the bearing surface 15b.
In this state, when the gear portion 36 is rotated by a finger or the like in the direction of arrow R along the direction in which the torsion spring 13 is tightened, the operating member 35 rotates while the shaft portion 37 rolls on the bearing surface 15b. By this rotation, the first shaft member 1
Since 1 rotates, the torsion spring 13 can be wound up via the first shaft member 11.

After the winding of the torsion spring 13 is completed, the first shaft member 1 is moved by a pin (not shown).
1 rotation is regulated. This regulation is, for example, the operation window 15
The pin is inserted through the slit 16 of the first shaft member 11
It can be easily done by plugging in. By inserting the pin, the first shaft member 11 does not rotate, and the second shaft member 12 does not advance.

Even in such an embodiment, even if the rotation operation from the rear end side of the case 14 cannot be performed by the arrangement as shown in FIG. Since the rotation operation of the first shaft member 11 can be performed, the torsion spring 13 can be wound up through the first shaft member 11. For this reason, the attachment and detachment of the tensioner 10 in a state where the cam sprocket 3 prevents the tooth jump can be surely performed.

The present invention is not limited to the above embodiments, but can be variously modified. For example, instead of the engagement hole 21 in the first embodiment, a convex engagement portion may be formed to rotate the first shaft member 11. Also, the engagement teeth 31 in the second embodiment
The shaft member 11 may be formed in a state recessed from the outer surface of the rear end portion 11b. Further, as a spring for urging the first shaft member 11 to rotate, a spiral spring or other appropriate spring can be used. Further, the spring may bias the first shaft member 11 so that the second shaft member 12 is drawn into the case 14. Although not shown, also in this case, the chain guide 5 is arranged so that the timing chain 4 holds the tension, and the second shaft member 12 is connected to the chain guide 5. In addition, the present invention can be similarly applied to devices other than the engine body of the automobile.

[0045]

As described above, according to the first aspect of the present invention, since the rotating operation of the first shaft member can be performed from the side surface of the case, the spring is wound via the first shaft member. It can be tightened and the tensioner can be securely attached and detached. Therefore, tooth jump of the cam sprocket and the like can be reliably prevented.

According to the second aspect of the present invention, by rotating the first shaft member in the engaged state of the operation member inserted from the operation window on the side surface of the case, the spring can be wound and tightened. Even when the rear end of the case cannot be operated, the spring can be wound up, and the attachment and detachment of the cushion can be reliably performed.

According to the third aspect of the present invention, in addition to the effect of the second aspect, the operating member is engaged with the engaging groove and the operating member is moved in the longitudinal direction of the operating window. Since the first shaft member can be rotated, the spring can be wound up, and the tensioner can be securely attached and detached.

According to the fourth aspect of the present invention, in addition to the effect of the second aspect, the operating member is moved in a state where the engaging teeth of the operating member are meshed with the engaging teeth of the first shaft member. By rotating the first shaft member, the spring can be wound up even when the rear end of the case cannot be operated, so that the tensioner can be securely attached and detached. .

[Brief description of the drawings]

FIG. 1 is a partially broken front view of an engine body to which the present invention is applied.

FIG. 2 is a front view of the first embodiment of the tensioner.

FIG. 3 is a left side view of FIG. 2;

FIG. 4 is a longitudinal sectional view of FIG.

FIG. 5 is a sectional view taken along line AA of FIG. 2;

FIG. 6 is a front view of a tensioner according to a second embodiment.

FIG. 7 is a left side view of FIG.

8 is a longitudinal sectional view of FIG.

FIG. 9A is a front view of an operation member according to the second embodiment,
(B) is a side view.

FIG. 10 is an enlarged sectional view taken along line BB of FIG. 6;

FIG. 11 is an enlarged sectional view taken along line CC of FIG. 6;

FIG. 12 is a sectional view of a conventional tensioner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Tensioner 11 1st shaft member 12 2nd shaft member 13 Torsion spring 14 Case 15 Operation window 21 Engagement hole 25 Operation member 31 Engagement tooth 35 Operation member 36 Gear part 37 Shaft part 38 Biting tooth

Claims (4)

[Claims] A first rotatable shaft member; a first rotatable shaft member;
A second shaft member that is screwed to the shaft member and moves in the axial direction while rotation is restricted;
And a spring that is wound around by rotation of the shaft member in one direction and biases the first shaft member to rotate in the other direction is housed inside the case. A tensioner, wherein a rotation operation from the outside is enabled from a side surface of the case. 2. A first rotatable shaft member and a first rotatable shaft member.
A second shaft member that is screwed to the shaft member and moves in the axial direction while rotation is restricted;
And a spring which is wound and tightened by rotation of the shaft member in one direction and biases the first shaft member to rotate in the other direction is housed inside the case, and rotates the first shaft member. A tensioner, wherein an engaging portion with which an operating member to be engaged is formed on the first shaft member, and an operation window through which the operating member can be inserted is opened on a side surface of the case facing the engaging portion. . 3. The engaging portion includes a plurality of engaging grooves formed on an outer periphery of the first shaft member, and the operation window is elongated along a rotation direction of the first shaft member. The tensioner according to claim 2, wherein the tensioner is formed. 4. The engaging member includes engaging teeth formed on the entire outer surface of the first shaft member, and the operating member includes a meshing tooth meshing with the engaging teeth formed on the entire outer surface. 3. The tensioner according to claim 2, further comprising a gear portion, and a shaft portion formed integrally with the gear portion and supported on an end face of the operation window.