JP2003322226A - Blade-type tensioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blade-type tensioner having a function to guide the tip section of a blade shoe, which is easily machined and assembled. <P>SOLUTION: The blade tensioner is provided with the blade shoe 2, which has a chain running face 2a and wherein a base end section 20 is rotatably supported on a base 4 and a tip section 21 is slidably supported on the slide plate 41 of the base 4, and a blade spring 3, which is arranged on the side opposite to the chain running face of the blade shoe 2. The slide plate 41 is curved into an arc-shape and has a recessed arc face 41a. The tip section 21 of the blade shoe 2 has a projected arc face 21c, which corresponds to the recessed arc face 41a of the slide plate 41a and slides on the recessed arc face 41a. In this case, the tip section 21 of the blade shoe 2 is guided so as to be positioned at the center position on the slide plate 41 in its widthwise direction by the automatic aligning action of the recessed arc face 41a of the slide plate 41. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blade tensioner composed of a blade shoe and a leaf spring-shaped blade spring attached to the blade shoe, and to an improvement in its structure.

[0002]

2. Description of the Related Art A blade tensioner is used as a tensioner for exerting tension on a chain. A conventional blade tensioner rotatably supports the base end of the blade shoe and a plurality of blade springs mounted on the back side of the resin-made blade shoe and the rear side of the blade shoe, and allows the tip to slide. It is composed of a supporting metal base. During operation of the blade tensioner, the elastic repulsive force due to the deformation of the blade spring acts on the chain as a pressing load.

Further, in the blade tensioner disclosed in Japanese Patent Laid-Open No. 2000-234656, a pair of guide portions for guiding the movement of the tip portion of the blade shoe when the tip portion slides on the base is provided on the base. ing. These guide portions are provided integrally with the slide surface on both side edges in the width direction of the slide surface of the base,
It is bent in the direction orthogonal to the slide surface. In addition, a convex arc surface is formed on the side where each guide portion faces the tip of the blade shoe, which reduces the sliding resistance between each guide portion and the blade shoe, and improves the smoothness of the blade shoe. Movement is ensured.

[0004]

[Patent Document 1] Japanese Patent Laid-Open No. 2000-234656 (see paragraph number [0036])

The convex arcuate surface formed on the guide portion is generally formed by ironing, but this ironing must be repeated a plurality of times with respect to the guide portion before bending. In the conventional blade tensioner, the machining of the base is troublesome.

The present invention has been made to solve the above-mentioned conventional problems, and an object thereof is to provide a blade tensioner which has a guide function for the tip of the blade shoe and can be easily processed and assembled. To do.

[0007]

A blade tensioner according to the invention of claim 1 is a blade tensioner for exerting a tension force on a chain, which is rotatably supported by a base and a chain traveling surface. And an arc-shaped blade shoe having an arc, and a leaf spring blade spring disposed on the side opposite to the chain running surface of the blade shoe. The tip of the blade shoe is slidably supported by a slide plate provided on the base.
The slide plate is curved in an arc shape so as to have a concave arc surface on the side facing the tip of the blade shoe,
The tip portion of the blade shoe has a convex arc surface corresponding to the concave arc surface of the slide plate.

According to the first aspect of the present invention, when the blade tensioner is in operation, the tip of the blade shoe contacts the slide plate and slides on the slide plate. At this time, the tip of the blade shoe has a convex arc surface. Touches the concave arc surface of the slide plate. As a result, the concave arc surface of the slide plate exerts a guide function by self-aligning action with respect to the convex arc surface of the blade shoe tip, and as a result, when the blade shoe tip slides on the slide plate, The blade shoe tip is always guided so as to be positioned at the widthwise central position on the slide plate.

In this case, a slide plate bent in an arc shape is used as a member exhibiting the guide function of the tip portion of the blade shoe, and this slide plate can be bent and deformed by a single bending process. .
Further, it is not necessary to perform complicated processing such as ironing processing on the base. This facilitates processing of the base and thus the entire blade tensioner.

A blade tensioner according to a second aspect of the present invention is, like the first aspect of the invention, a blade tensioner for exerting a tension force on a chain, which comprises a base and
The base is provided with an arc-shaped blade shoe rotatably supported and having a chain running surface, and a leaf spring blade spring disposed on the side opposite to the chain running surface of the blade shoe. The tip of the blade shoe is slidably supported by a slide plate provided on the base. The tip of the blade shoe has a convex arcuate surface, and the slide plate has at least two flat portions that intersect each other and contact the convex arcuate surface of the tip of the blade shoe.

According to the second aspect of the present invention, when the blade tensioner is in operation, the tip of the blade shoe abuts the slide plate and slides on the slide plate. Is in contact with the convex arcuate surface of the tip of the blade shoe, and thereby the tip of the blade shoe is guided so as to be positioned at the center position in the width direction on the slide plate.

In this case, a slide plate bent so as to intersect with each other is used as a member exhibiting the guide function of the tip of the blade shoe, and the bending deformation of this slide plate can be performed by a single bending process. Is. Further, it is not necessary to perform complicated processing such as ironing processing on the base. This facilitates processing of the base and thus the entire blade tensioner.

A blade tensioner according to a third aspect of the present invention is, like the first aspect of the invention, a blade tensioner for exerting a tension force on a chain, which includes a base and
The base is provided with an arc-shaped blade shoe rotatably supported and having a chain running surface, and a leaf spring blade spring disposed on the side opposite to the chain running surface of the blade shoe. The tip of the blade shoe is slidably supported by a slide plate provided on the base. A ridge portion extending in the longitudinal direction is formed at the center of the blade shoe in the width direction, and a groove for movably receiving the ridge portion is formed on the slide plate.

According to the third aspect of the present invention, when the blade tensioner is in operation, the tip of the blade shoe abuts on the slide plate and slides on the slide plate. It engages with the groove of the slide plate, so that when the blade shoe tip portion slides on the slide plate, the blade shoe tip portion is guided so as to be positioned at the widthwise center position on the slide plate. .

In this case, a ridge formed on the tip of the blade shoe and a groove formed on the slide plate are used as a member that exerts the guide function of the tip of the blade shoe. Both molding and groove processing of the slide plate are easy. Further, it is not necessary to perform complicated processing such as ironing processing on the base.
This facilitates processing of the base and thus the entire blade tensioner.

A blade tensioner according to a fourth aspect of the present invention is, like the first aspect of the invention, a blade tensioner for exerting a tension force on a chain, which includes a base,
The base is provided with an arc-shaped blade shoe rotatably supported and having a chain running surface, and a leaf spring blade spring disposed on the side opposite to the chain running surface of the blade shoe. The tip of the blade shoe is slidably supported by a slide plate provided on the base. In addition, a groove extending in the longitudinal direction is formed at the center of the blade shoe in the width direction, and the slide plate is formed with a ridge portion that movably engages with the groove.

According to the invention of claim 4, when the blade tensioner is in operation, the tip of the blade shoe abuts on the slide plate and slides on the slide plate. Engages with the groove of the tip portion, so that when the blade shoe tip portion slides on the slide plate, the blade shoe tip portion is guided so as to be positioned at the widthwise center position on the slide plate. .

In this case, a groove formed on the tip of the blade shoe and a ridge formed on the slide plate are used as a member for exhibiting the guide function of the tip of the blade shoe. The groove can be easily formed by resin molding, and the ridge on the slide plate can be easily formed by pressing. Further, it is not necessary to perform complicated processing such as ironing processing on the base. This facilitates processing of the base and thus the entire blade tensioner.

A blade tensioner according to a fifth aspect of the present invention is, like the first aspect of the invention, a blade tensioner for exerting a tension force on a chain, which includes a base and
The base is provided with an arc-shaped blade shoe rotatably supported and having a chain running surface, and a leaf spring blade spring disposed on the side opposite to the chain running surface of the blade shoe. The tip of the blade shoe is slidably supported by a slide plate provided on the base. In addition, a pair of guide portions that hang down beyond both side ends of the slide plate are integrally formed at both end portions in the width direction of the tip end portion of the blade shoe.

According to the fifth aspect of the present invention, when the blade tensioner is in operation, the tip of the blade shoe abuts on the slide plate and slides on the slide plate. Each hanging guide portion guides the movement of the blade shoe tip portion on the slide plate from both sides.

In this case, since the guide portions integrally formed at both side edges of the blade shoe tip are used as the member exhibiting the guide function of the blade shoe tip.
It is not necessary to perform a complicated process such as ironing on the base, and the blade tensioner can be easily processed.

A blade tensioner according to a sixth aspect of the present invention is, like the first aspect of the invention, a blade tensioner for exerting a tension force on a chain, which includes a base and
The base is provided with an arc-shaped blade shoe rotatably supported and having a chain running surface, and a leaf spring blade spring disposed on the side opposite to the chain running surface of the blade shoe. The tip of the blade shoe is slidably supported by a slide plate provided on the base. Further, a through hole penetrating the tip portion in the width direction is formed at the tip portion of the blade shoe, and the through hole has a pair of U-shapes having a pair of guide portions that hang down beyond both side ends of the slide plate. -Shaped guide member is inserted.

According to the invention of claim 6, when the blade tensioner is in operation, the tip of the blade shoe abuts on the slide plate and slides on the slide plate. At this time, the through hole of the tip of the blade shoe is inserted. Each guide portion of the U-shaped guide member guides the movement of the tip of the blade shoe on the slide plate from both sides.

In this case, since a U-shaped guide member inserted into the through hole of the blade shoe tip is used as a member for exhibiting the guide function of the blade shoe tip, complicated processing such as ironing is performed. Since it is not necessary to apply to the base, the blade tensioner can be easily processed.

A blade tensioner according to a seventh aspect of the present invention is, like the first aspect of the invention, a blade tensioner for exerting a tension force on a chain, which includes a base,
The base is provided with an arc-shaped blade shoe rotatably supported and having a chain running surface, and a leaf spring blade spring disposed on the side opposite to the chain running surface of the blade shoe. The tip of the blade shoe is slidably supported by a slide plate provided on the base. In addition, the base end and the tip of the blade shoe are formed with grooves for inserting the respective ends of the blade spring, and these grooves avoid contact with the respective ends of the blade spring. Recessed recesses are formed respectively. In the concave relief part on the tip side,
A U-shaped guide member having a pair of guide portions that hang down over both side ends of the slide plate is inserted.

According to the invention of claim 7, when the blade tensioner is in operation, the tip of the blade shoe abuts on the slide plate and slides on the slide plate. At this time, the concave relief portion of the tip of the blade shoe is removed. Each guide portion of the U-shaped guide member to be inserted guides the movement of the tip portion of the blade shoe on the slide plate from both sides.

In this case, since a U-shaped guide member inserted into the concave relief portion of the blade shoe tip portion is used as a member for exhibiting the guide function of the blade shoe tip portion, complicated work such as ironing is required. There is no need to perform processing on the base, and processing of the blade tensioner becomes easy.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. [ First Embodiment ] FIG. 1 is a side view of a blade tensioner according to a first embodiment of the present invention, and FIG. 2 is a partial view taken along the arrow II in FIG.

As shown in FIG. 1, a blade tensioner 1
Is a resin blade shoe 2 which has a chain running surface 2a on which a chain (not shown) runs while sliding, and which is curved in an arc shape, and a leaf spring which is arranged on the opposite side of the chain running surface 2a of the blade shoe 2. It is mainly composed of a plurality of blade springs 3 and a metal base 4 to which the blade shoes 2 are attached.

A pin 5 having one end fixed to the base 4 is inserted through the base end portion 20 of the blade shoe 2, and the blade shoe 2 is rotatably supported by the pin 5. Further, a groove 20a having a concave escape portion 20b is formed in the base end portion 20 of the blade shoe 2.

The tip 21 of the blade shoe 2 is slidably supported by a slide plate 41 integrally provided on the base 4. Further, a groove 21a having a recessed escape portion 21b is formed in the tip portion 21 of the blade shoe 2.

One end of the blade spring 3 is inserted into the groove 20a on the base end side of the blade shoe 2, and the other end is inserted into the groove 21a on the tip end side of the blade shoe 2. At this time, since the recessed escape portions 20b and 21b are formed in the grooves 20a and 21a, the edge portions of the tips of the blade springs 3 are formed at the blade shoes 2a.
Direct contact with is avoided.

As shown in FIG. 2, the slide plate 41 is bent in an arc shape by being bent, and has a concave arc surface 41a on the side facing the blade shoe tip 21. . On the other hand, the blade shoe tip 2
1, a convex arc surface 21c corresponding to the concave arc surface 41a of the slide plate 41 is formed. Further, the base 4 is formed with a plurality of mounting holes 41 (FIG. 1) into which bolts for mounting the blade tensioner are inserted.

During operation of the blade tensioner, the chain runs while sliding on the chain running surface 2a of the blade shoe 2. At this time, the elastic repulsive force due to the deformation of the blade spring 3 acts on the chain as a pressing load. , This maintains the tension of the chain.

When operating the blade tensioner,
With the deformation of the blade shoe 2 and the blade spring 3, the blade shoe tip 21 slides on the slide plate 41 in a state where the blade shoe tip 21 is in contact with the slide plate 41 of the base 4.

At this time, the convex arcuate surface 21c of the blade shoe tip 21 is changed to the concave arcuate surface 4 of the slide plate 41.
It is in sliding contact with 1a. As a result, the slide plate 4
The concave arc surface 41a of No. 1 exerts a guide function by the self-aligning action with respect to the convex arc surface 21c of the blade shoe tip portion 21, and as a result, when the blade shoe tip portion 21 slides on the slide plate 41. The blade shoe tip 21 is always guided so as to be positioned at the center position on the slide plate 41 in the width direction (left-right direction in FIG. 2).

In this case, the blade shoe tip 21
A slide plate 41 bent in an arc shape is used as a member exhibiting the guide function of 1. The bending deformation of the slide plate 41 can be performed by a single bending process. Further, it is not necessary to perform complicated processing such as ironing processing on the base. This facilitates processing of the base 4 and thus the entire blade tensioner.

[ Second Embodiment ] FIG. 3 is a side view of a blade tensioner according to a second embodiment of the present invention, and FIG. 4 is a partial view taken along arrow IV of FIG. In these figures,
The same reference numerals as those in the first embodiment indicate the same or corresponding portions.

As shown in FIGS. 3 and 4, in the second embodiment, the slide plate is composed of slide plates 41 and 41 'which are bent into a flat and substantially V shape.

During operation of the blade tensioner, the blade shoe tip portion 21 slides on the slide plates 41 and 41 'with the blade shoe tip portion 21 in contact with the slide plates 41 and 41'. The arcuate surface 21c is in sliding contact with each flat surface 41b, 41'b intersecting in a V shape on the slide plates 41, 41 '. Thereby, when the pressing force is applied from the blade shoe tip 21 to the slide plates 41, 41 'during operation, the flat surfaces 41b, 41'b cause the blade shoe tip 21 to slide on the slide plates 41, 4'.
It acts so as to be positioned at the widthwise central position of 1 '.

In this case, the blade shoe tip 21
The slide plates 41 and 41 'bent so as to intersect each other are used as the member exhibiting the guide function of 1. The bending deformation of the slide plates 41 and 41' can be performed by one bending process. Further, it is not necessary to perform complicated processing such as ironing processing on the base. This facilitates processing of the base and thus the entire blade tensioner.

[ Third Embodiment ] FIG. 5 is a side view of a blade tensioner according to a third embodiment of the present invention, and FIG. 6 is a sectional view taken along line VI-VI of FIG. In these figures, the same reference numerals as those used in the first or second embodiment denote the same or corresponding parts.

As shown in FIGS. 5 and 6, in the third embodiment, the blade shoe tip portion 21 has a ridge portion 21d 'extending in the longitudinal direction at the center portion in the width direction (left and right direction in FIG. 6). Have The slide plate 41 is formed with a groove 41c for movably receiving the ridge 21d '. The ridge 21d' projects downward beyond the groove 41c.

When the blade tensioner is in operation, the blade shoe tip 21 is moved to the flat surface 4 of the slide plate 41.
The slide plate 41 slides on the slide plate 41 while being in contact with 1b. At this time, the ridge 21d 'formed at the center of the blade shoe tip 21 is slid on the slide plate 41.
Is engaged with the groove 41c. Accordingly, when the blade shoe tip 21 slides on the slide plate 41, the blade shoe tip 21 is guided so as to be positioned at the center position in the width direction on the slide plate 41.

In this case, the blade shoe tip 21
As a member that exerts the guide function of, the ridge 21d 'formed on the blade shoe tip 21 and the groove 41c formed on the slide plate 41 are used.
Both the resin molding of 1d 'and the groove processing of the slide plate 41 are easy. Further, it is not necessary to perform complicated processing such as ironing processing on the base. This allows
The base and thus the entire blade tensioner can be easily processed.

[ Fourth Embodiment ] Although not shown, the fourth embodiment is a modification of the third embodiment, and, contrary to the third embodiment, a slide plate is used. 41 has a ridge, and a groove in the longitudinal direction with which the ridge engages is formed in the blade shoe tip 21.

Also in this case, during operation, the blade shoe tip 21 can be positioned at the widthwise center position on the slide plate 41, and the ridges on the slide plate 41 can be press-formed and the blade shoe tip can be formed. Grooving into 21 is easy,
This facilitates processing of the base and thus the entire blade tensioner.

[ Fifth Embodiment ] FIG. 7 is a side view of a blade tensioner according to a fifth embodiment of the present invention, and FIG. 8 is a partial view taken along arrow VIII of FIG. In these figures, the same symbols as those in the first to fourth embodiments indicate the same or corresponding parts.

As shown in FIGS. 7 and 8, in the fifth embodiment, a pair of left and right tensions is formed so that the blade shoe tip portion 21 hangs down from both side edges in the width direction (left and right direction in FIG. 8). It has a projecting portion (guide portion) 21d. The slide plate 41 has a flat surface 41b on the side facing the blade shoe tip 21. Each overhanging portion 21d of the blade shoe tip portion 21 is integrally formed when the blade shoe 2 is resin-molded, and extends beyond both side ends of the slide plate 41.

When the blade tensioner is in operation, the blade shoe tip portion 21 moves toward the flat surface 4 of the slide plate 41.
While sliding on the slide plate 41 in a state of contacting with 1b, at this time, each overhanging portion 21d hanging from both side edges of the blade shoe tip portion 21 moves the blade shoe tip portion 21 on the slide plate 41. Guide from both sides.

In this case, the blade shoe tip 21
Since the overhanging portions 21d integrally formed on both side edges of the blade shoe tip portion 21 are used as a member that exerts a guide function of the blade tensioner, it is not necessary to perform complicated processing such as ironing processing on the base, and the blade tensioner Processing becomes easy.

[ Sixth Embodiment ] FIG. 9 is a side view of a blade tensioner according to a sixth embodiment of the present invention, and FIG. 10 is a partial view taken along arrow X in FIG. In these figures, the same symbols as those in the first to fifth embodiments indicate the same or corresponding parts.

As shown in FIG. 9 and FIG.
In the above embodiment, the blade shoe tip portion 21 has a through hole 21e penetrating the tip portion in the width direction (left and right direction in FIG. 10).
have. The slide plate 4 is provided in the through hole 21e.
A pair of left and right guide portions 6a that hang down beyond both side ends of 1
A guide piece (guide member) 6 having is inserted.
The guide piece 6 is formed by, for example, bending a metal strip in a U shape.

When the blade tensioner is in operation, the blade shoe tip portion 21 moves toward the flat surface 4 of the slide plate 41.
While sliding on the slide plate 41 in a state of being in contact with 1b, at this time, each guide portion 6 of the U-shaped guide piece 6 which is inserted through the through hole 21e of the blade shoe tip portion 21.
a guides the movement of the blade shoe tip 21 on the slide plate 41 from both sides.

In this case, the blade shoe tip 21
Since the U-shaped guide piece 6 inserted into the through hole 21e of the blade shoe tip portion 21 is used as a member for exhibiting the guide function of the blade shoe, it is not necessary to perform complicated processing such as ironing on the base, The tensioner can be easily processed.

[ Seventh Embodiment ] FIG. 11 shows a seventh embodiment of the present invention.
12 is a side view of a blade tensioner in accordance with the embodiment of FIG.
It is a XII arrow partial view of FIG. In these figures, the same reference numerals as those in the first to sixth embodiments indicate the same or corresponding parts.

As shown in FIGS. 11 and 12, in the seventh embodiment, a pair of left and right guide portions 6'that hang down beyond the both side ends of the slide plate 41 in the concave relief portion 21b of the blade shoe tip portion 21. A guide piece (guide member) 6'having a is inserted. Guide piece 6 '
Is formed by bending a metal strip in a U-shape as in the sixth embodiment.

During operation of the blade tensioner, the tip portion 21 of the blade shoe is placed on the flat surface 4 of the slide plate 41.
While sliding on the slide plate 41 in a state of contacting with 1b, at this time, each guide portion 6'a of the U-shaped guide piece 6'inserted through the concave relief portion 21b of the blade shoe tip portion 21 slides. The movement of the blade shoe tip 21 on the plate 41 is guided from both sides.

In this case, the blade shoe tip 21
As a member that exerts the guide function of the above, since the U-shaped guide piece 6'inserted in the concave relief portion 21b of the blade shoe tip portion 21 is used, it is not necessary to perform complicated processing such as ironing on the base. , Processing of blade tensioner becomes easy.

In each of the above-described embodiments, the slide plate portion is formed on a part of the base 4 so that the slide plates 41 and 41 'are integrally provided on the base 4, but the present invention is not limited to this. The application is not limited to this, and the slide plate produced separately from the base 4 is
The present invention can be similarly applied to the one integrally attached to the base 4 using a well-known fixing means such as welding or bolting.

[0061]

As described above, according to the present invention, there is an effect that it is possible to realize a blade tensioner that has a guide function for the tip of the blade shoe and that can be easily processed and assembled.

[Brief description of drawings]

1 is a side view of a blade tensioner according to a first embodiment of the present invention. FIG.

FIG. 2 is a partial view taken along line II of FIG.

FIG. 3 is a side view of a blade tensioner according to a second embodiment of the present invention.

FIG. 4 is a partial view taken along line IV of FIG.

FIG. 5 is a side view of a blade tensioner according to a third embodiment of the present invention.

6 is a sectional view taken along line VI-VI of FIG.

FIG. 7 is a side view of a blade tensioner according to a fifth embodiment of the present invention.

FIG. 8 is a partial view taken along arrow VIII of FIG.

FIG. 9 is a side view of a blade tensioner according to a sixth embodiment of the present invention.

FIG. 10 is a partial view taken along arrow X in FIG.

FIG. 11 is a side view of a blade tensioner according to a seventh embodiment of the present invention.

12 is a partial view taken along arrow XII of FIG.

[Explanation of symbols]

1: Blade tensioner 2: Blade shoe 2a: Chain running surface 20: Base end 20a: groove 20b: concave relief portion 21: Tip 21a: groove 21b: concave relief portion 21c: convex arc surface 21d: Overhang part (guide part) 21d ': ridge 21e: Through hole 3: Blade spring 4: Base 41: Slide plate 41 ': slide plate 41a: concave arc surface 41b: flat surface 41'b: flat surface 41c: groove 6: Guide piece (guide member) 6a: Guide part 6 ': Guide piece (guide member) 6'a: Guide part

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Naoji Sakamoto             Mie prefecture Nabari city Hachiman character Kuchi Irino 1300 No. 50 Bol             Gwarner Morstec Japan Co., Ltd.             Inside the company F term (reference) 3J049 AA08 BB02 BB10 BB12 BE08                       BE09

Claims (7)

[Claims] 1. A blade tensioner for exerting a tension force on a chain, comprising a base and a chain traveling surface, a base end portion is rotatably supported by the base, and a tip end portion is the base. An arc-shaped blade shoe slidably supported by a slide plate provided in, and a leaf spring blade spring disposed on the side opposite to the chain running surface of the blade shoe, wherein the slide plate is The blade shoe is curved in an arc shape so as to have a concave arc surface on the side opposite to the tip portion, and the tip portion of the blade shoe has a convex arc surface corresponding to the concave arc surface of the slide plate. It has a self-centering action of the concave arc surface of the slide plate so that the tip of the blade shoe is on the slide plate. It is guided so as to be positioned in the widthwise direction central position, the blade tensioner, characterized in that. 2. A blade tensioner for exerting a tension force on a chain, which has a base and a chain traveling surface, a base end portion is rotatably supported by the base, and a tip end portion is the base. An arc-shaped blade shoe slidably supported by a slide plate provided in, and a leaf spring blade spring disposed on the opposite side of the chain running surface of the blade shoe, the blade shoe of the The tip portion has a convex arcuate surface, the slide plate has at least two flat surface portions that intersect each other, and each flat surface portion contacts the convex arcuate surface of the tip end portion of the blade shoe. Guides the tip of the blade shoe so that it is positioned at the center position in the width direction on the slide plate. Blade tensioner according to claim. 3. A blade tensioner for exerting a tension force on a chain, comprising a base and a chain traveling surface, a base end portion is rotatably supported by the base, and a tip end portion is the base. An arc-shaped blade shoe slidably supported by a slide plate provided in, and a leaf spring blade spring disposed on the opposite side of the chain running surface of the blade shoe, the blade shoe of the A ridge portion extending in the longitudinal direction is formed at the tip in the widthwise central portion,
A blade tensioner characterized in that a groove for movably receiving the ridge is formed in the slide plate. 4. A blade tensioner for exerting a tension force on a chain, comprising a base and a chain traveling surface, a base end portion is rotatably supported by the base, and a tip end portion is the base. An arc-shaped blade shoe slidably supported by a slide plate provided in, and a leaf spring blade spring disposed on the opposite side of the chain running surface of the blade shoe, the blade shoe A groove extending in the longitudinal direction is formed in the widthwise central portion of the tip portion, and a ridge portion with which the groove is movably engaged is formed on the slide plate. Blade tensioner to do. 5. A blade tensioner for exerting a tension force on a chain, comprising a base and a chain traveling surface, a base end portion is rotatably supported by the base, and a tip end portion is the base. An arc-shaped blade shoe slidably supported by a slide plate provided in, and a leaf spring blade spring disposed on the opposite side of the chain running surface of the blade shoe, the blade shoe of the A blade tensioner, wherein a pair of guide portions that hang down beyond both side ends of the slide plate are integrally formed at both end portions in the width direction of the tip end portion. 6. A blade tensioner for exerting a tension force on a chain, comprising a base and a chain traveling surface, a base end portion is rotatably supported by the base, and a tip end portion is the base. An arc-shaped blade shoe slidably supported by a slide plate provided in, and a leaf spring blade spring disposed on the opposite side of the chain running surface of the blade shoe, the blade shoe of the A through hole is formed in the tip portion so as to penetrate the tip portion in the width direction, and the through hole has a U-shaped guide member having a pair of guide portions that hang down beyond both side ends of the slide plate. The blade tensioner is characterized in that. 7. A blade tensioner for exerting a tension force on a chain, comprising a base and a chain traveling surface, a base end portion is rotatably supported by the base, and a tip end portion is the base. An arc-shaped blade shoe slidably supported by a slide plate provided in, and a leaf spring blade spring disposed on the opposite side of the chain running surface of the blade shoe, the blade shoe of the A groove for inserting each end of the blade spring is formed in each of the base end portion and the tip end portion, and each groove has a concave shape for avoiding contact with each end portion of the blade spring. Relief portions are respectively formed, and the recessed relief portion of the tip portion has a pair of guide portions that hang down beyond both side ends of the slide plate. Shaped guide member is inserted, the blade tensioner, characterized in that.