JPH0266355A - Tensioner - Google Patents

Abstract

PURPOSE:To effectively lock the push of a pressing member by using a stopper having a slip preventing means provided at the position where the curved face and part of the pressing member abuts. CONSTITUTION:A stopper 100 is expanded, opened end parts 101 are separated from a casing 20 to remove. Before a tensioner is mounted on an equipment, the push of a pressing member 40 is locked. After it is mounted on the equipment, the tension of the tensioner is applied. In such a stopper 100, a small hole 110 is opened at a position corresponding to the abutting position of the end part of the pressing member 40 and its edge part is engaged with a part of the end part of curved end of the pressing member 40. Thus, the stopper 100 is not unexpectedly detached, thereby a stable pushing lock state being obtained.

Description

[Detailed Description of the Invention] [Field of Application in Industry A] The present invention relates to a tensioner that applies a constant tension to a chain or timing belt that drives the camshaft of an engine of a two-wheeled vehicle or a four-wheeled vehicle. be.

[Prior Art] Tensioners such as chain tensioners and belt tensioners are used to press the chain or belt in a certain direction to maintain a certain tension when the chain or belt becomes loose due to stretching or abrasion during use. is used to maintain the

FIG. 9 shows a conventional tensioner disclosed in Japanese Utility Model Application No. 19015/1983. A cylindrical casing 1 that is installed substantially vertically through a fixing bolt hole 1a, a shaft-shaped rotating body 2 that is rotatably inserted into the casing 1,
A pressing body 3 is screwed onto a male threaded portion 2a formed at the tip of the rotary body 2 and is propelled by the rotation of the rotary body 2, and a spring (torsion) is fitted onto the rotary body 2 and applies rotational force to the rotary body 2. The main parts are constituted by a spring) 4 and a bearing 5 which has a non-circular bearing hole through which the pressing body 3 passes, is fixed to the casing 1, and restricts rotation of the pressing body 3.

In such a configuration, the rotating body 2 is rotated and the spring 4 is
Chain suppressor 3 with rotational energy stored in
When the rotating body 2 comes into contact with an external member such as a belt, the spring 4
This rotational force is transmitted to the suppressor 3. However, since the rotation of the suppressing body 3 is restricted by the bearing 5, the rotational force of the rotary body 2 is converted into propulsive force to press the chain, belt, etc. This allows chains, belts, etc. to maintain a constant tension without loosening.

In the figure, 7 is a seal bolt screwed into the base end (lower end) of the casing 1, and 6 is a bellows that covers between the pressing body 3 and the casing 1.

With such a tensioner, it is necessary to lock the propulsion of the pressing body 3 before assembling the device or during transportation, and for this purpose, the stopper 10 is used. The stopper lO is configured such that the hook portion 10a on the open end side is locked to the outer surface of the casing 1 while in contact with the tip of the suppressor 3, thereby locking the propulsion of the suppressor 3, thereby preventing the device from being propagated. The assembly is to be removed later.

[Problem to be solved by the invention] In the tensioner described above, the pressing body 3 that comes into contact with external materials
The distal end portion 3a has a flat shape. However,
When the external material is a belt or chain, the edge portion of the flat tip 3a interferes with the belt or chain directly or with the pressing member that presses it, causing a hindrance to the endless movement of the belt or chain. The tip 3a of the body 3 is formed into an arcuate curved surface. For the suppressor 3 having such a situation, a stopper 10 shown in FIG.
If this is applied, there is an inconvenience that slippage occurs between the tip 3a of the suppressor 3 and the stopper 10, the stopper 10 comes off, the lock of the presser 3 is released, and the presser is propelled.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a tensioner that can reliably lock even a suppressor having a curved tip.

[Means for Solving the Problems] The present invention provides a screwed state in which a rotating body that is rotationally biased by a spring and a pressing body whose rotation is restrained by a bearing and whose tip portion that comes into contact with external members is formed into a curved surface. inserted into the casing with
In the device for converting the rotational force of the rotating body into an axial propulsive force of the pressing body, a stopper is removably attached to the casing and comes into contact with a tip of the pressing body to lock the propulsion of the pressing body; The stopper is characterized by comprising means for preventing the tip of the pressing body from slipping, which is provided at a contact area of the tip of the pressing body.

[Function] In the above configuration, the curved tip of the suppressor comes into contact with the anti-slip means formed on the stopper, and the stopper is prevented from coming off by the engagement force or frictional force with the anti-slip means. There is.

[Embodiment] FIGS. 1, 2, and 3 show the overall configuration of an embodiment of the present invention. The tensioner includes a casing 20 in which an axial cavity 21 is formed, a rotating body 30 and a pressing body 40 that are screwed into the cavity 21 of the casing 20.
A spring (torsion spring) 50 that applies rotational force to the rotating body 30, a bearing 60 that is attached to the tip of the casing 20 (the left end in FIG. 1) and restricts the rotation of the pressing body 40, and the casing 20 and the pressing It is provided with a bellows 70 which can be expanded and contracted to cover the space between the body 40 and the body 40.

In the present invention, as will be described later, the pressing body 40 performs a propulsion motion by the rotation of the rotary body 30, and its tip 45 makes smooth contact with external materials such as chains and belts. It is formed into an arc-shaped curved surface. The pressing body 40 is propelled by the energy stored in the spring 50 via the rotating body 30, and a stopper 100 is used to prevent unnecessary propulsion when the tensioner is not used. stopper 100
As shown in FIGS. 2 and 3, it has a band shape bent at a substantially right angle, and its open end 101 is folded back inside to form a groove 2 on the outer surface of the casing 20.
By being inserted into 7, it is attached to casing 20. Then, the stopper 100 is expanded and the open end 101
Its removal is effected by separating it from the groove 27. As a result, when the tensioner is assembled to the device, the forward motion of the pressing body 4o is locked, and when the tensioner is later removed, the tensioning action of the tensioner is performed. Such a stopper 100
A means for preventing the tip of the pressing body from slipping is provided at the contact area of the tip 45 of the pressing body 40. In this embodiment, as shown in FIG. 6, a small hole 110 is opened at a position corresponding to the abutment area of the distal end portion 45 to form the anti-slip means 45. Since the edge of the small hole 100 engages with a portion of the curved tip 45 of the pressing body 40, the engagement force prevents the stopper 100 from slipping. For this reason,
The stopper 100 does not come off inadvertently, and a stable propulsion lock state can be obtained.

7 and 8 show another example of the anti-slip means of the stopper 100. In FIG. 7, a circular arc portion 120 projecting outward is formed approximately at the center of the band-shaped stopper lOO. This arcuate portion 120 has a curved tip 45 of the pressing body 40.
A portion of the stopper enters and engages, and the engagement force prevents the stopper from slipping against each other, thereby preventing the stopper from coming off. In FIG. 8, a friction band 130 is wound around the approximate center of the stopper 100. As shown in FIG. The friction band 130 is made of a material such as rubber or synthetic resin that has a large coefficient of friction, and when the tips 45 of the suppressing bodies 40 come into contact with each other, the frictional force prevents each other from slipping. This results in
The stopper 100 is prevented from coming off. In the illustrated example, the friction band 14 is also provided at the open end 101 of the stopper 100.
This is to prevent the casing 2o from coming off the slit 27. The anti-slip means are not limited to those described above, and may be appropriate grooves, knurling, or other means. By providing such a non-slip means, the stopper 100 can reliably lock the pushing body 40 from advancing.

Each element of the present invention will be specifically explained below.

The casing 20 is to be attached to equipment such as an engine (not shown), and a mounting hole 22 for this purpose is formed in the outer part. Further, a seal bolt 80 is screwed into the base end (the right end in FIG. 1) via a packing 81 to maintain airtightness on the base end side.

The rotating body 30 is rotatably supported within the casing 20. The rotating body 30 is formed by connecting a male threaded portion 3 on the distal end side and a shaft portion 32 on the proximal end side, and a suppressor 40 is screwed into the male threaded portion 31 to transmit rotational force. conduct. Further, the shaft portion 32 is supported within the support recess 23 of the casing 20 for rotational support. In this case, a bottomed cylindrical support member 82 is provided between the shaft portion 32 and the support recess 23 of the casing. The support member 82 is inserted between the rotating body 30 and the casing 20 to provide rotational support for the rotating body 30. By inserting the supporting member 82 in this way, the rotational support of the rotating body 30 is smoothly supported. In addition, since the process is performed reliably, it is not necessary to process the support recess 23 of the casing 20 with high precision, and the rotating body 30
This makes it possible to prevent wear of the casing 20. Note that the shaft portion 32 of this rotating body 30 has an axial split slit 3.
3 is formed and, as will be described later, is engaged with a spring 5o and biased to rotate.

The pressing body 40 includes a vibrator 42 having a female thread 41 formed on its inner surface, and a bushing shaft 43 fitted into the tip of the vibrator 42 .

The vibrator 42 is screwed into the male threaded portion 31 of the rotating body 3o to transmit the rotational force of the rotating body 30, and is also inserted into the bearing 60 in a rotationally restrained state to convert the rotational force of the rotating body 3o into propulsive force. It is something. On the other hand, a portion of the bush shaft 43 including a tip 45 formed into a curved surface extends outward from the casing 2o, and the tip portion 45 directly hits a chain, belt, etc., or a roller that presses them. contact through. This maintains tension in chains, belts, etc.

The spring 50 is connected to such a pressing body 4o and the rotating body 30.
has been extrapolated to This spring 5o is inserted into the pressing body 40 and the rotating body 3o when they are in a screwed state, and the extrapolated portion extends from the inside to the outside of the rotating body 30.
, a pressing body 4o, and a spring 50.

Such a triple structure has the advantage that a sufficient stroke of the pressing body 40 can be ensured even if the length of the device in the advancing and retracting direction of the pressing body 40 is shortened. Here, one end 51 of the spring 50 is bent into an oval shape to engage with the casing 20, and the other end 52 is formed into a split slit 33 of the rotating body 30.
The rotor 30 is inserted into the rotor 30 to engage with the rotating body 30. Therefore, when the seal bolt 80 is removed, the casing 2
Insert a screwdriver etc. into the split slit 33 from the outside of the
When the rotating body 30 is rotated, rotational energy can be stored in the spring 50. Note that the end 52 on the rotating body side at 5° of the spring is connected to the split slit 33 of the rotating body 30.
After being inserted into the rotating body 30, it is bent in the radial direction of the rotating body 30, but due to this bending, the spring 5 is
The above-mentioned radial displacement of spring 5o can be prevented, and stable operation of spring 5o is ensured.

The bearing 60 restricts the rotation of the pressing body 40, and is prevented from being pulled out by the circlip 61 so that the casing 20
Attached to the tip of the 4 and 5 show the structure of this bearing 60 and its installation. The bearing 60 has a bearing hole 62 formed in the center part, and engagement pieces 63 formed at 90 degree intervals in the outer part. ing. Bearing hole 62
The pressing body 40 is formed into a substantially oval shape in which both sides of a circle are cut parallel to each other, and the outer shape is the same.
The vibration part 42 is inserted into the bearing hole 62 to restrain the rotation of the pressing body 40. On the other hand, the engagement piece 63 restricts rotation against the rotational force of the rotating body 30. For this reason, the casing 2 corresponds to the engagement piece 63.
Engagement grooves 24 are formed at 90 degree intervals on the distal end surface of the 0, and the rotation is restrained by fitting the engagement pieces 63 into the engagement grooves 24. In this case, the depth of the engagement groove 24 of the casing 20 is larger than that of the engagement piece 63, and the bearing 60 is installed in a state slightly retracted from the front end surface of the casing 20. A clip groove 25 into which the circlip 61 is fitted is formed on the inner surface of the casing 20 that protrudes beyond the bearing 60.

Furthermore, a spacer 9 is provided between the bearing 60 and the casing 20.
0 is inserted. The spacer 90 is inserted between the bearing 60 and the casing 20 at the opposing portion, and in particular, the portion of the bearing 6o corresponding to each engagement piece 63 is bent into a U-shape so as to wrap around each engagement piece 63. As a result, the engaging piece 63
and the engagement groove 24 of the casing 20. The spacer 90 having such a structure prevents the pressing force of the engaging piece 63 due to the rotational force of the rotating body 30 transmitted through the pressing body 40 from directly acting on the casing 20 with the wide surface of the spacer 90. Therefore, the engagement piece 63 and the casing 2
This makes it possible to prevent the end faces of the engagement grooves 24 from being worn out.

In this way, by using the spacer 90 for the bearing 60 and using the supporting member 82 of the rotating body 30, the casing 2
0 can be made of a material with poor wear resistance such as aluminum or synthetic resin, and even in this case, the tensioner can prevent wear of the casing 20 at the mounting part of the bearing 60 and the shaft part of the rotating body 30. It operates without any problems and is lightweight. In addition, one end 51 of the spring 50 is extracted from a part of the engagement groove 24 in the casing 20 to be engaged with the casing 20 described above.

Next, the bellows 70 is passed between the bush shaft 43 of the pressing body 40 and the casing 20, and covers the space between them. A protruding line 71 is formed on the inner surface of the end of the bellows 70 on the pressing body 40 side.
is fitted into a corresponding groove 44 formed on the outer surface of the bush shaft 43. The end portion on the pressing body 40 side is sealed by winding the garter spring 72 from the outside. On the other hand, the end on the casing side is connected to a cap 73 attached to the casing 20. Note that this connection can be made by any suitable means such as adhesion or welding. The cap 73 is made of a substantially cylindrical hard material with an inner diameter that is approximately equal to the outer diameter of the casing 20 on the base side and whose tip is slightly bent inward. It is attached to the casing 20 by caulking 74 at a predetermined position on the outer peripheral surface of 73. The bellows 7o is connected to a bent portion at the tip of the cap 73. Furthermore, casing 20
A circumferential groove 26 is formed on the outer surface, and a seal ring 75 is wound around this circumferential groove 26. The seal ring 75 is made of an elastic body, and when the cap 73 is attached to the casing 20 while being wound around the circumferential groove 26, the cap 73
It comes into close contact with the inner surface and the outer surface of the casing 20 to seal the space between them. Therefore, intrusion of dust from the outside and leakage of the lubricating oil sealed inside the casing 20 are prevented.

With the structure using such a seal ring 75, airtightness between the cap 73 and the casing 20 can be ensured. Therefore, when attaching the cap 73, it is not necessary to press-fit the cap to maintain airtightness of the part, and there is no need for a high degree of dimensional accuracy for press-fitting. Therefore, processing can be performed easily and productivity is improved.

In addition, in FIG. 1, 40a, 60a and 90a are circulation paths for lubricating oil established in the pressing body 40, the bearing 6o, and the spacer 90, respectively. Casing lubricant 20
It is designed to circulate evenly inside.

[Effects of the Invention] As explained above, the present invention uses a stopper provided with an anti-slip means at the portion where the curved tip of the pressing body comes into contact, so that there is no slippage between the tip of the pressing body and the stopper. , there is no slippage, and the stopper can reliably lock the propulsion of the pressing body without coming off.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, FIGS. 2 and 3 are a plan view and a side view thereof, and FIGS. 4 and 5 are perspective views and sectional views showing a bearing mounting structure, Figure 6 (a
), (b) is a diagram showing an example of a stopper, FIG. 7(b),
8(b) and FIGS. 8(a) and 8(b) are views showing other examples of the stopper, and FIG. 9 is a sectional view of the conventional example. 20...Casing, 3o...Rotating body, 4o...
Pressing body, 50... Spring, 60... Bearing, 100...
- Stopper, 110.120,130... Anti-slip means. (Otsu Roy 0O 48 figures full 41st J51

Claims (1)

[Scope of Claims] A rotating body biased to rotate by a spring and a pressing body whose rotation is restrained by a bearing and whose tip portion is formed into a curved surface and comes into contact with an external member are inserted into a casing in a screwed state, The apparatus for converting the rotational force of the rotating body into the axial propulsion force of the pressing body, further comprising: a stopper that is removably attached to the casing and comes into contact with the tip of the pressing body to lock the propulsion of the pressing body; A tensioner comprising: anti-slip means for the tip of the pressing body provided at a contact portion of the stopper with the tip of the pressing body.