JP2005325855A - Blade tensioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve rigidity of a blade shoe, and to prevent fall of a blade spring. <P>SOLUTION: The blade tensioner is provided with a blade spring 3 arranged in a blade shoe 2 on a side opposite to a chain sliding surface 2a and to be inserted into a first cut 21a formed in a tip 21 of the blade shoe 2 in one end thereof and to be inserted into a second cut 22a formed in a base end 22 of the blade shoe 2 in the other end thereof and for applying spring force to a chain, and a base member 4 having a pin 42 for turnably supporting the base end 22 of the blade shoe 22 and having a slide surface 41 for slidably supporting the tip 21 of the blade shoe 2 when the blade shoe 2 is deformed. The first cut 21a is formed with a first and a second side wall parts 21c and 21d opposite to a first and a second side surfaces 3c and 3d of the blade spring 3, and the second cut 22a is formed with a second side wall part 22c opposite to the first side surface 3c of the blade spring 3. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a blade tensioner including a blade shoe having a chain sliding surface and a leaf spring-like blade spring that applies a spring force to the shoe.

  In an automobile engine, a blade tensioner is used as a tensioner for applying a tension force to a timing chain or an auxiliary machine (oil pump or the like) driving chain.

  As shown in Japanese Patent Application Laid-Open No. 2000-234656, a conventional blade tensioner is arranged by laminating a blade shoe having a chain sliding surface curved in an arc shape on the opposite side of the chain sliding surface of the blade shoe. Via a plurality of leaf springs for applying spring force to the chain, and a support shaft that rotatably supports the base end of the blade shoe. The tip of the blade shoe is slidable. And a base member having a slide surface to be supported. Each end portion of the blade spring is engaged with a notch formed in the distal end portion and the proximal end portion of the blade shoe.

  During chain operation, the chain travels while sliding on the chain sliding surface of the blade shoe. At this time, the spring force accompanying the elastic deformation of the blade spring acts on the chain as a pressing load, maintaining the chain tension. It has come to be. In addition, when the chain tension fluctuates during operation, the tip of the blade shoe slides on the slide surface and the base end rotates around the support shaft so that the blade shoe and the blade spring The radius of curvature changes, and a spring force corresponding to the deformation acts on the chain.

  By the way, when an excessive pressing load is applied from the chain at the time of resonance of the chain span, the blade shoe may be excessively deformed to the side where the radius of curvature is increased. In such a case, an excessive bending stress is generated at the positions where the incisions are formed in the leading end and the base end of the blade shoe.

However, in the conventional blade tensioner, only a notch for inserting a blade spring is formed at the distal end portion and the proximal end portion of the blade shoe.
JP 2000-234656 A

  The problem to be solved by the present invention is to improve the rigidity of the blade shoe and to prevent the blade spring from falling off in the blade tensioner.

  A blade tensioner according to a first aspect of the present invention is a blade shoe having a chain sliding surface curved in an arc shape, and a blade shoe disposed on the opposite side of the chain sliding surface of the blade shoe and formed at the tip of the blade shoe. One end is inserted into one notch and the other end is inserted into a second notch formed at the base end portion of the blade shoe, and a leaf spring shape for applying a spring force to the chain via the blade shoe A base member having a plurality of blade springs, a support shaft portion that rotatably supports the base end portion of the blade shoe, and a slide surface that slidably supports the tip portion of the blade shoe when the blade shoe is deformed And. The first cut has a first side wall portion facing the side surface on one end side of the blade spring, and the second cut has a second side wall facing the side surface on the other end side of the blade spring. The part is formed.

  According to the first aspect of the present invention, the first and second cuts of the blade shoe are not opened on both sides, and have first and second side walls, respectively. The rigidity of the location can be improved. Thus, even when an excessive pressing load is applied from the chain, the blade shoe can be prevented from being excessively pushed, and as a result, the chain behavior can be controlled not only by the blade spring but also by the blade shoe. In addition, in this case, each side wall portion is disposed opposite to the side surface on the end portion side of the blade spring, so that it is possible to prevent the blade spring from falling off from each notch of the blade shoe.

  According to a second aspect of the present invention, in the first aspect, any one of the first and second side wall portions is provided at a position facing both side surfaces on one end side or the other end side of the blade spring. In this case, the rigidity of the blade shoe can be further improved where the side wall portions are disposed on both sides of the blade spring. At the same time, the blade spring can be prevented from falling off from both sides of each notch of the blade shoe.

  According to a third aspect of the present invention, in the first aspect, when the blade shoe and the blade spring are deformed to the side where the radius of curvature is increased, the contact member disposed so that the lowermost blade spring contacts the base member or the engine The corresponding contact member is provided with an extending portion disposed on both sides of the blade spring.

  In this case, the behavior of the chain can be reliably controlled by the contact member, and the blade spring can be reliably prevented from falling off from the side by the extending portion of the contact member.

  According to a fourth aspect of the present invention, in the first aspect, in the first or second cut at each end portion of the blade shoe, a pin for connecting opposing wall surfaces of the cut is implanted. In this case, the planted pin can further increase the rigidity of the notch formation portion at each end of the blade shoe and can prevent the blade spring from falling off. In this case, since it is only necessary to embed a pin after the blade spring is assembled into the blade shoe, the blade spring can be easily assembled.

  According to a fifth aspect of the present invention, in the first aspect, the clip member having a pair of leg portions disposed on both sides of the blade spring is attached to the longitudinal central portion of the blade shoe. In this case, the clip member can more reliably prevent the blade spring from falling off the blade shoe.

  With the blade tensioner according to the present invention, the rigidity of the blade shoe can be improved, and the blade spring can be prevented from falling off.

  1 to 5 are views for explaining a blade tensioner according to an embodiment of the present invention. FIG. 1 is a front view of the blade tensioner installed in a chain system, and FIG. 2 is pushed by the chain. FIG. 3 is a sectional view taken along line III-III in FIG. 1, FIG. 4 is a sectional view taken along line IV-IV in FIG. 1, and FIG. 5 is a sectional view taken along line VV in FIG.

  As shown in FIG. 1, the blade tensioner 1 includes a blade shoe 2 having a chain sliding surface 2 a that is curved in an arc shape, and a blade shoe 2 that is stacked on the opposite side of the chain sliding surface 2 a of the blade shoe 2. Are mainly composed of a plurality of leaf springs 3 in the form of leaf springs for applying a spring force to a chain (not shown) via a base, and a base member 4 for supporting the blade shoe 2.

  The blade shoe 2 has a distal end portion 21 and a proximal end portion 22 provided on the other end side, and the chain sliding surface 2 a extends between the distal end portion 21 and the proximal end portion 22. . A first notch 21a is formed in the distal end portion 21, and one end 3a of the blade spring 3 is inserted and locked into the first notch 21a. Similarly, a second cut 22a is formed in the base end portion 22, and the other end 3b of the blade spring 3 is inserted into and locked in the second cut 22a.

  The tip portion 21 of the blade shoe 2 is slidably supported by a flat slide surface 41 provided on the base member 4. The tip 21 is always in contact with the slide surface 41 so as to slide on the slide surface 41 when the blade shoe 2 is deformed according to the pressing load from the chain.

  As shown in FIG. 3, the slide surface 41 has a flat, substantially V-shaped cross section, and the tip portion 21 of the blade shoe 2 is substantially cross-sectional along the slide surface 41 having such a substantially V-shaped cross section. It has a V-shaped contact surface 21b.

  A pin (support shaft portion) 42 fixed to the base member 4 is inserted into the base end portion 22 of the blade shoe 2 (see FIG. 5), and the base end portion 22 is rotatable around the pin 42. It is supported.

  As shown in FIG. 3, the first cut 21 a is formed with a side wall portion 21 c that faces the first side surface 3 c on one end side of the blade spring 3. Further, as shown in FIG. 4, not only the side wall portion 21 c but also the side wall portion 21 d facing the second side surface 3 d of the blade spring 3 is formed at the bottom of the first cut 21 a. As shown in FIG. 5, the second cut 22 a is formed with a side wall portion 22 c that faces the first side surface 3 c on the other end side of the blade spring 3.

  A contact member 5 is attached to the base member 4 at a predetermined interval from the lowermost blade spring 3. The abutting member 5 is a substantially T-shaped member, and has a pad portion 50 having a curved surface (abutting surface) 50a with which the lowermost blade spring 3 abuts when the blade spring 3 is deformed at maximum, and below the pad portion 50. The shaft portion 51 extends and is locked to the base portion 4. The base member 4 is formed with a plurality of mounting holes 43 into which mounting bolts (not shown) are inserted.

Next, the operation of the blade tensioner configured as described above will be described.
During operation, a chain (not shown) slides on the chain sliding surface 2 a of the blade shoe 2, and at this time, a spring force according to the deformation of the blade spring 3 is passed through the blade shoe 2 through the chain. By acting on the chain tension, the chain tension is maintained. At this time, the contact surface 21b of the blade shoe distal end portion 21 is moved while sliding on the slide surface 41 having a substantially V-shaped cross section in accordance with the deformation of the blade shoe 2.

  In this case, the notches 21a and 22a of the blade shoe 2 are not open on both sides, and have first and second side walls, respectively. Can be improved. As a result, even when an excessive pressing load is applied from the chain, the blade shoe 2 can be prevented from being excessively deformed and pushed in. As a result, the chain behavior can be controlled not only by the blade spring 3 but also by the blade shoe 2. Can also be done.

  In addition, in this case, since the notches 21a and 22a of the blade shoe 2 are closed at least on one side, the blade spring 3 is prevented from falling off from the notches 21a and 22a of the blade shoe 2 to the sides. it can.

  Further, since the side wall portions 21c and 21d are provided on both sides of the blade spring 3 at the bottom of the first notch 21a of the blade shoe 2, the rigidity of the blade shoe 2 can be further improved, and the blade shoe 2 It is possible to prevent the blade spring 3 from falling off from both sides of the first cut 21a.

  Next, when excessive tension is generated in the chain due to resonance of the chain and an excessive pressing force acts on the blade shoe 2 from the chain, the blade shoe 2 and the blade spring 3 are moved to the side where the radius of curvature becomes large. Deform. At this time, the lowermost blade spring 3 contacts the contact surface 50a of the pad portion 50 of the fixing member 5 (see FIG. 2). Thereby, further deformation of the blade shoe 2 and the blade spring 3 is stopped. In this way, the movement of the blade spring 3 and the blade shoe 2 can be controlled.

  In the above embodiment, the contact member 5 simply has the curved surface 50a on the contact side with the lowermost blade spring 3, but the application of the present invention is not limited to this. . 6A and 6B show a modification of the contact member, where FIG. 6A is a front view of the contact member, and FIG. 6B is a side view thereof. In FIG. Shows the part.

  This contact member 5 'differs from the contact member 5 of the above embodiment in that it has a pair of extending portions 52 extending from both sides of the pad portion 50 in a direction orthogonal to the contact surface 50a. Yes. These extending portions 52 are arranged on the sides of the first and second side surfaces 3c, 3d of the blade spring 3, and thereby, the falling off of the blade spring 3 from the side can be prevented more reliably. The slit 51 a formed in the shaft portion 51 is for reducing the diameter of the shaft portion 51 when the shaft portion 51 is inserted into the mounting hole of the base member 4.

  FIG. 7 shows a blade shoe / blade spring assembly in a blade tensioner according to a second embodiment of the present invention. In FIG. 7, the same reference numerals as those in the embodiment denote the same or corresponding parts.

  As shown in FIG. 7, in this second embodiment, a pin (here, a roll pin or spring pin) 6 is planted so as to connect the opposing wall surface of the second notch 22a at the base end portion 22 of the blade shoe 2. It is installed. In this case, the planted pin 6 can further increase the rigidity of the notch formation portion at the base end portion 22 of the blade shoe 2 and can prevent the blade spring 3 from falling off. In this case, since the pin 6 may be embedded after the blade spring 3 is assembled into the blade shoe 2, the blade spring 3 can be easily assembled.

  8 and 9 show a blade shoe and blade spring assembly in a blade tensioner according to a third embodiment of the present invention, in which (a) is a front view of the blade shoe and blade spring assembly, (B) is the whole perspective view of the clip member. In the figure, the same reference numerals as those in the above embodiment denote the same or corresponding parts.

  As shown in FIG. 8, in the blade tensioner 1, a clip member 7 is attached to a substantially central portion in the longitudinal direction of the blade shoe 2. As shown in FIG. 9, the clip member 7 includes a flat plate-like main body portion 70, a claw portion 71 that rises upward from both side edges of the main body portion 70 and is fixed to both side surfaces of the blade shoe 2, and a main body portion. It has at least a pair (here, two pairs) of leg portions 72 that hang downward from both side edges of the 70 and are disposed on both sides of the blade spring 3. The leg 72 of the clip member 7 can more reliably prevent the blade spring 3 from coming off from the side.

  In each of the above embodiments, the blade tensioner unitized with the base member has been described as an example. However, the present invention is not unitized with the base member, that is, the blade is attached to the engine-side component corresponding to the base member. It may be a blade tensioner configured to be attached with a shoe. In this case, the contact member is also attached to an engine side component, for example, an engine block.

  The blade tensioner according to the present invention is particularly suitable for a timing chain of an automobile engine, but may be applied to an accessory driving chain such as an oil pump.

It is a front view of the blade tensioner of the installation state by one Example of this invention. FIG. 2 is a front view of the blade tensioner of FIG. 1 in a state where a blade spring is pushed from a chain. It is the III-III sectional view taken on the line of FIG. It is the IV-IV sectional view taken on the line of FIG. It is the VV sectional view taken on the line of FIG. The modification of the contact member is shown, (a) is a front view, (b) is a side view. FIG. 6 is an overall perspective view of a blade shoe / blade spring assembly constituting a blade tensioner according to a second embodiment of the present invention. FIG. 6 is a front view of a blade shoe / blade spring assembly constituting a blade tensioner according to a third embodiment of the present invention. FIG. 9 is a perspective view of a clip member incorporated in a blade shoe / blade spring assembly (FIG. 8).

Explanation of symbols

1: Blade tensioner

2: Blade shoe 2a: Chain sliding surface 21: Tip portion 21c: (First) side wall portion 21d: (First) side wall portion 22: Base end portion 22c: (Second) side wall portion

3: Blade spring 3c: First side 3d: Second side

4: Base member 41: Slide surface 42: Pin (support shaft)

Claims (5)

A blade tensioner for applying tension to the chain,
A blade shoe having a distal end portion, a proximal end portion provided on the other end side, a chain sliding surface extending between the distal end portion and the proximal end portion and curved in an arc shape;
One end of the blade shoe is disposed on the opposite side of the chain sliding surface of the blade shoe, and one end thereof is inserted into the first notch formed at the distal end portion, and the second notch formed at the proximal end portion. A plurality of leaf springs in the form of leaf springs, the other ends of which are inserted, and a spring force is applied to the chain via the blade shoes;
A base member having a support shaft portion that rotatably supports the base end portion of the blade shoe, and a slide surface that slidably supports the tip portion of the blade shoe when the blade shoe is deformed. ,
The first notch is formed with a first side wall portion facing the side surface on the one end side of the blade spring, and the second notch has a side surface on the other end side of the blade spring. Opposing second side wall portions are formed,
Blade tensioner characterized by that. In claim 1,
Either one of the first or second side wall portions is provided at a position facing both side surfaces on the one end side or the other end side of the blade spring.
Blade tensioner characterized by that. In claim 1,
When the blade shoe and the blade spring are deformed to the side where the radius of curvature is increased, an abutting member arranged so that the lowermost blade spring abuts is provided on the base member or the engine side, The contact member is provided with an extending portion disposed on both sides of the blade spring.
Blade tensioner characterized by that. In claim 1,
A pin for connecting opposing wall surfaces of the cut in the first or second cut is planted at the distal end or the base end of the blade shoe.
Blade tensioner characterized by that. In claim 1,
A clip member having a pair of legs disposed on both sides of the blade spring is attached to the longitudinal center of the blade shoe.
Blade tensioner characterized by that.

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