JP5425015B2 - Chain tensioner lever - Google Patents

Description

  The present invention relates to a chain tensioner lever, and more particularly, to a chain tensioner lever having a structure in which a shoe surface is pressed against a chain by a resilient force of a torsion coil spring to bias the chain.

  Conventionally, in a chain transmission device that transmits rotation between shafts at separate positions, for example, used for driving an auxiliary machine such as an automobile engine, in order to eliminate chain slack and prevent chain run-out during running As a chain tensioner lever, a shoe surface for sliding the chain is formed along the longitudinal direction, and the lever base end is pivotally supported by the lever mounting surface, and the lever body and lever mounting 2. Description of the Related Art A chain tensioner lever that includes a torsion coil spring that is interposed between a surface and a shoe surface that presses a shoe surface against the chain by its biasing force is known.

FIG. 8 shows an example of a chain tensioner lever of this type that is conventionally known. The chain tensioner lever 500 accommodates at least the winding portion 521 of the torsion coil spring 520 in the lever main body 510. The spring accommodating part 530 is formed inside, and an opening in which the torsion coil spring 520 can be incorporated is provided in the spring accommodating part 530, and the winding part 521 of the torsion coil spring 520 is provided in the spring accommodating part 530. A boss portion 514 having a boss outer peripheral surface 114a to be loosely fitted is provided.
In addition, when the chain tensioner lever 500 is assembled and attached to the attachment surface R, a part of the lever peripheral wall portion 511 forming the spring accommodating portion 530 is twisted so as to be inserted into the spring attachment hole sh and generate a torsion torque. A cutout region 516a through which the support arm portion 523 that is locked to the attachment surface R side of the coil spring 520 passes is formed.
Further, before the lever main body 510 is assembled and mounted on the mounting surface R, the support arm 523 is previously engaged with the engagement recess 516b provided at one end of the notch region 516a, and the torsion coil spring 520 is twisted. There has been proposed one in which a torsion coil spring 520 can be incorporated in the lever main body 510 in a state where torque is generated (see Patent Document 1).

  In the conventional chain tensioner lever 500, the pressing arm portion 522 that biases the shoe surface S of the torsion coil spring 520 is positioned at the corner of the shoe surface side peripheral wall portion 511 a of the spring housing portion 530, and the winding of the torsion coil spring 520 is performed. A support arm that is inserted into the spring mounting hole sh of the mounting surface R when the turning portion 521 is loosely fitted to the boss portion 514 and the lever main body 510 is assembled to the mounting surface R on the engine side surface at the other end of the torsion coil spring 520. The portion 523 is engaged with the engaging recess 516b formed at one end of the notch region 516a formed in the opening of the spring accommodating portion 530 in a twisted state so as not to come out of the lever body 510. The chain tensioner lever 500 was stored and transported (see FIG. 8).

JP 2000-274501 A JP 2009-108909 A

However, in the conventional chain tensioner lever 500, the lever main body 510 is rotated while the support arm 523 is engaged with the engagement recess 516b, and the support arm 523 is inserted into the spring mounting hole sh. The lever main body 510 is intended to be assembled to the surface R. However, depending on the arrangement of the chain C, the entire lever main body 510 may be rotated while the torsion coil spring 520 is engaged with the engagement recess 516b. It is difficult to align the spring mounting hole sh and the tip of the support arm portion 523, and the support arm portion 523 of the torsion coil spring 520 housed in the lever body 510 while maintaining the lever body 510 at an appropriate angle. Is removed from the engagement recess 516b, and the support arm 523 of the torsion coil spring 520 is deformed and attached to the position of the spring mounting hole sh. That there was also.
In such a case, the tip of the support arm portion 523 of the torsion coil spring 520 is made into the spring mounting hole sh of the mounting surface R in a state where the support arm portion 523 of the torsion coil spring 520 is removed from the engaging portion 516b of the lever peripheral wall portion 511. As shown in FIG. 8, the torsion coil spring 520 is located on the mounting surface side of the lever body 510 and is hidden by the lever body 510, as shown in FIG. The person performs the assembling work in a state where only the support arm portion 523 of the torsion coil spring 520 is visible.
As described above, since the worker must perform the assembly work without visually observing the state of the torsion coil spring 520, the torsion coil spring 520 is displaced from the original mounting position, tilted, or in extreme cases. As a result, the torsion coil spring 520 falls off and the torsion coil spring 520 cannot be fixed at the designed position, and the assembly work of the chain tensioner lever 500 cannot be performed smoothly (see FIG. 10).

  Further, in the assembly work of the conventional chain tensioner lever 500, the lever main body 510 is assembled to the mounting surface R from the state in which the torsion coil spring 520 is previously locked and accommodated in the lever main body 510 as in the above-described prior art. The engaging recess is not provided on the mounting surface side peripheral wall portion of the lever main body 510, and the torsion coil spring is attached to the spring accommodating portion 530 of the lever main body 510 at the stage of assembling the chain tensioner lever 500 to the mounting surface R. In some cases, the torsion coil spring 520 is assembled to the mounting surface R without being engaged with the lever main body 510, and in such a case, the position of the torsion coil spring 520 is stabilized in the lever main body 510. In addition, there are more problems in the assembling work such as dropping of the torsion coil spring 520 as described above. Was al.

  In the chain tensioner lever 500 of the prior art, the distal end of the pressing arm portion 522 of the torsion coil spring 520 is positioned at the corner of the spring accommodating portion 530 so that the pressing arm portion 522 is rotated relative to the lever body 510. Since it did not occur, even if the pressing arm portion 522 of the torsion coil spring 520 is locked at an appropriate place to prevent the falling off, a member that locks the pressing arm 522 and prevents the falling off is arranged. The torsion coil spring 520 without making the operation of mounting the torsion coil spring 520 to the lever body 510 difficult, such as how to engage the pressing arm portion 522 of the torsion coil spring 520 with such a locking member. There has been a problem that it has not been solved yet about how to prevent the dropout.

  The present invention solves the problems of the prior art as described above, and the technical problem of the present invention, that is, the object of the present invention is to prevent the torsion coil spring from falling off during assembly work on the mounting surface. An object of the present invention is to provide a chain tensioner lever that reliably blocks and to which a torsion coil spring is easily attached.

  According to a first aspect of the present invention, there is provided a lever main body formed on a pivot shaft that is erected on a mounting surface by forming a shoe surface for sliding the chain along the longitudinal direction, and the lever main body, A chain tensioner lever provided between a mounting surface and a torsion coil spring that presses the shoe surface against the chain, wherein the lever body includes a shoe surface side peripheral wall portion on which the shoe surface is formed and the shoe A lever peripheral wall portion composed of an anti-shoe surface side peripheral wall portion facing the surface side peripheral wall portion, an arc-shaped peripheral wall portion connecting the shoe surface side peripheral wall portion and the anti-shoe surface side peripheral wall portion, and anti-attachment of the lever peripheral wall portion A lever side wall portion covering the surface side, a reinforcing rib portion interposed between any two of the shoe surface side peripheral wall portion, the anti-shoe surface side peripheral wall portion and the arc-shaped peripheral wall portion, and the lever side wall portion. The pivot shaft A shaft hole that penetrates, a boss portion that forms a boss outer peripheral surface for loosely fitting the torsion coil spring, and a spring locking rib portion that protrudes from the shoe surface side peripheral wall portion and engages with the torsion coil spring. The torsion coil spring includes a pressing arm portion that presses an inner surface of the shoe surface side peripheral wall portion, a winding portion that is connected to the pressing arm portion, and a support arm portion that is supported on the mounting surface. In the spring accommodating part defined by the shoe surface side peripheral wall part, the reinforcing rib part and the arc-shaped peripheral wall part, the boss outer peripheral surface of the boss part is loosely fitted via a winding part, and the pressing arm part of the torsion coil spring is When the spring is biased by the elastic force of the torsion coil spring, the pressing position is in contact with the inner surface of the peripheral surface of the shoe surface side wall, and the elastic force does not act on the torsion coil spring in the direction opposite to the biasing direction. A member that abuts against the inner surface of the reinforcing rib when rotated. The spring locking rib portion engages with the pressing arm portion of the torsion coil spring between the pressing position and the locking position so as to rotate from the spring accommodating portion. The torsion coil spring is prevented from coming out, and the torsion coil spring is biased while pressing the pressing arm portion of the torsion coil spring against the inner surface of the reinforcing rib portion in a state where the winding portion is eccentric with respect to the boss portion. The above-described problem is solved by being able to move to the unlocking position that is out of the space between the pressing position engaged by the spring locking rib portion and the locking position.

  The chain tensioner lever of the invention according to claim 2 further solves the above-described problem by the tip of the spring locking rib portion having an arc shape in addition to the configuration of the invention according to claim 1. Is.

  A chain tensioner lever according to a third aspect of the present invention is the same as that of the first or second aspect of the invention, wherein the spring locking rib portion is wide in the loading / unloading direction of the torsion coil spring and perpendicular to the rotation direction. The above-described problems are further solved by being formed narrow in the direction to be applied.

  The chain tensioner lever of the invention according to claim 4 is locked to the mounting surface side when the lever body is assembled and mounted to the mounting surface in addition to the configuration of the invention according to any one of claims 1 to 3. A notch region through which the support arm portion of the torsion coil spring is inserted is formed on a part of the mounting surface side of the lever peripheral wall portion defining the spring accommodating portion, and the elastic force when the torsion coil spring is attached to the lever body Thus, the above-described problem is further solved by forming an engagement recess for engaging and holding the support arm portion of the torsion coil spring at one end of the notch region.

  A chain tensioner lever according to a fifth aspect of the present invention is the chain tensioner lever according to any one of the first to fourth aspects, wherein the torsion coil spring causes the winding portion to be eccentric with respect to the boss portion. In a state where the pressing arm portion of the torsion coil spring is biased while being pressed against the inner surface of the reinforcing rib portion, the relationship between the pressing position engaged by the spring locking rib portion and the locking position is removed. By being able to move to the stop release position, the above-described problem is further solved.

  Therefore, according to the tensioner lever for a chain of the present invention, a lever body that is formed to have a shoe surface that slides the chain along the longitudinal direction and is rotatably supported by a pivot shaft that is erected on the mounting surface; By providing a torsion coil spring that is interposed between the lever body and the mounting surface and presses the shoe surface against the chain, not only the chain can be slid reliably but also the following A specific effect can be produced.

  That is, according to the chain tensioner lever of the first aspect of the present invention, the lever body includes a shoe surface side peripheral wall portion on which the shoe surface is formed, and a shoe surface side peripheral wall portion and the shoe surface side peripheral wall portion and the shoe surface. A lever peripheral wall portion comprising an arc-shaped peripheral wall portion connecting the side peripheral wall portion and the anti-shoe surface side peripheral wall portion, a lever side wall portion covering the anti-mounting surface side of the lever peripheral wall portion, a shoe surface side peripheral wall portion and an anti-shoe Boss outer peripheral surface loosely fitted between the reinforcing rib portion interposed between any two of the surface side peripheral wall portion and the arc-shaped peripheral wall portion, the shaft hole standing from the lever side wall portion and penetrating the pivot shaft, and the torsion coil spring And a spring locking rib that protrudes from the shoe surface side peripheral wall and engages with the torsion coil spring, and the torsion coil spring presses the inner surface of the shoe surface side peripheral wall Winding connected to arm and pressing arm And a supporting arm portion attached to the mounting surface, and a spring housing portion defined by the shoe surface side peripheral wall portion, the reinforcing rib portion, and the arc-shaped peripheral wall portion, on the boss outer peripheral surface of the boss portion via the winding portion When the pressing arm portion of the torsion coil spring is loosely fitted and urged by the elastic force of the torsion coil spring, the elastic force acts on the pressing position that contacts the inner surface of the peripheral surface of the shoe surface and the torsion coil spring. The spring locking rib portion is disposed between the pressing position and the locking position so that the spring locking rib portion can be freely rotated between the pressing position and the locking position. The torsion coil spring is engaged with the pressing arm portion of the torsion coil spring to prevent the torsion coil spring from coming out of the spring accommodating portion, so that the torsion coil spring is provided by the spring locking rib portion provided on the lever peripheral wall portion of the lever body. Engage and hold in the spring housing of the lever body Since there is no fall off, the mounting operation of the tensioner lever chain can be performed reliably without error.

In addition, since the rotation range of the torsion coil spring is limited by the inner surface of the spring engaging rib portion, the possibility of mounting the torsion coil spring in an unstable state during rotation is greatly reduced and stable. Can be assembled.
Furthermore, the rotation range of the torsion coil spring is limited from the pressing position when pressing the shoe side peripheral wall portion to the locking position contacting the reinforcing rib portion, and the spring engagement rib portion does not fall off in this rotation range. Since the torsion coil spring can be attached / detached at the locking position, the torsion coil spring does not fall off in the rotation range assumed in a normal mounting state. The torsion coil spring can be virtually eliminated during the assembly of the tensioner lever, and the torsion coil spring can be easily mounted at the locking position. Assembling work of the spring can be simplified.
Further, when the torsion coil spring is biased while pressing the pressing arm portion of the torsion coil spring against the inner surface of the reinforcing rib portion in a state where the winding portion is eccentric with respect to the boss portion, the spring engaging rib portion engages. Because it is possible to move to the unlocking position that deviates between the combined pressing position and the locking position, the position where the torsion coil spring can be inserted / removed is only possible at the position where the torsion coil spring cannot normally be taken. The torsion coil spring can be easily assembled for the operator, and the torsion coil spring can be more reliably prevented from coming off from the lever body.

  According to the chain tensioner lever of the invention of claim 2, in addition to the effect of the invention of claim 1, the tip of the spring locking rib portion has an arc shape, so that the torsion coil spring The range of engagement with the pressing arm portion of the torsion coil spring becomes smaller as the tip of the spring locking rib portion engaging with the pressing arm portion approaches the locking position, and the torsion coil spring is locked at the locking position. Since the locking force to be applied is very small, it is possible for the operator to easily perform the mounting operation of the torsion coil spring at this locking position without requiring a particularly large force.

  According to the chain tensioner lever of the invention according to claim 3, in addition to the effect of the invention according to claim 1 or claim 2, the spring locking rib portion rotates wide in the loading / unloading direction of the torsion coil spring. Since the spring locking rib portion is wide in the direction in which the torsion coil spring falls off, the rigidity against the force of pulling out the spring is high. Accordingly, the retaining function for the torsion coil spring is greatly enhanced, and the possibility of damaging the spring locking rib portion can be greatly reduced.

  According to the chain tensioner lever of the invention according to claim 4, in addition to the effect of the invention according to any of claims 1 to 3, the chain tensioner lever is engaged with the attachment surface side when the lever body is assembled to the attachment surface. A notch region through which the supporting arm portion of the torsion coil spring to be stopped is inserted is formed on a part of the mounting surface side of the lever peripheral wall portion defining the spring accommodating portion, and due to the elastic force when the torsion coil spring is attached to the lever body Since the engaging recess for engaging and holding the support arm of the torsion coil spring is formed at one end of the notch region, when the torsion coil spring is previously attached to the lever body, the end of the notch region is Not only is the support arm of the torsion coil spring engaged with the provided engagement recess to prevent the torsion coil spring from falling off, but also the spring engagement rib is engaged with the pressing arm of the torsion coil spring. The chain tensioner lever can be stored and transferred in a state in which the torsion coil springs are prevented from falling off, such as preventing the coil springs from falling off. When the assembly work is performed with the engagement disengaged, the torsion coil spring can be prevented from falling off by the spring locking rib portion, and the assembly work can be stabilized.

The usage aspect figure of the tensioner lever for chains which is one Example of this invention. FIG. 2 is a cross-sectional arrow view on the AA line of FIG. 1. The back side perspective view of the lever main body shown by FIG. Explanatory drawing of the press position state of the torsion coil spring shown by FIG. Explanatory drawing of the latching position state of the torsion coil spring shown by FIG. Explanatory drawing of the latch release position state of the torsion coil spring shown by FIG. The partial cross section figure which shows the state of the spring at the time of the assembly | attachment of the lever main body shown by FIG. The perspective view of the tensioner lever for chains of a prior art. Explanatory drawing at the time of the assembly | attachment of the tensioner lever for chains of a prior art. Explanatory drawing of the spring drop-off state at the time of the assembly | attachment of the tensioner lever for chains of a prior art.

  According to the present invention, a shoe surface for sliding a chain is formed along a longitudinal direction, and is pivotally supported by a pivot shaft erected on the mounting surface, and between the lever main body and the mounting surface. A tensioner spring for a chain that is provided with a torsion coil spring that presses the shoe surface against the chain, and the lever body is opposite to the shoe surface side peripheral wall portion and the shoe surface side peripheral wall portion that form the shoe surface. A lever peripheral wall portion comprising a shoe surface side peripheral wall portion, an arc-shaped peripheral wall portion connecting the shoe surface side peripheral wall portion and the anti-shoe surface side peripheral wall portion, a lever side wall portion covering the anti-mounting surface side of the lever peripheral wall portion, and a shoe A reinforcing rib portion interposed between any two of the surface side peripheral wall portion, the anti-shoe surface side peripheral wall portion and the arc-shaped peripheral wall portion, a shaft hole standing from the lever side wall portion and penetrating the pivot shaft, and a torsion coil spring Loose fit A boss portion that forms an outer peripheral surface of the shoe, and a spring locking rib portion that protrudes from the peripheral wall portion of the shoe surface and engages with the torsion coil spring, and the torsion coil spring covers the inner surface of the peripheral surface portion of the shoe surface. A spring that includes a pressing arm portion that presses, a winding portion that is connected to the pressing arm portion, and a support arm portion that is supported on the mounting surface, and is partitioned by a shoe surface side peripheral wall portion, a reinforcing rib portion, and an arcuate peripheral wall portion The inner surface of the peripheral surface of the shoe surface side when the pressing arm portion of the torsion coil spring is urged by the elastic force of the torsion coil spring and is loosely fitted to the boss outer peripheral surface of the boss portion in the housing portion Rotating between the pressing position that contacts with the torsion coil spring and the locking position that contacts the inner surface of the reinforcing rib when the torsion coil spring does not act and rotates in the direction opposite to the urging direction And the spring locking rib portion is a torsion coil spring between the pressing position and the locking position. The torsion coil spring engages with the pressing arm portion to prevent the torsion coil spring from coming out of the spring accommodating portion, and the torsion coil spring presses the pressing arm portion of the torsion coil spring with the winding portion eccentric with respect to the boss portion. When it is biased while being pressed against the inner surface of the part, it can be moved to the unlocking position that is disengaged between the pressing position engaged by the spring locking rib and the locking position, and assembled to the mounting surface. As long as the torsion coil spring can be simply attached by reliably preventing the torsion coil spring from falling off during the operation, any specific mode may be used.

That is, the specific material of the lever body used in the present invention may be any material as long as it can achieve smooth sliding running of the chain, such as polyamide 46 resin, It is preferable to use a synthetic resin material such as polyamide 66 resin, polyacetal resin, or glass fiber reinforced polyamide resin.
In addition, it is preferable that the synthetic resin material as illustrated is integrally molded, but at least the surface of the lever body molded with a metal material such as aluminum is formed with a layer of the synthetic resin material illustrated above on the surface that is in sliding contact with the chain. There may be.

Also, various forms of engagement of the torsion coil spring by the spring locking rib portion provided on the main body lever are conceivable. For example, the front end portion of the spring locking rib portion is locked so as to become narrower in sequence. In the position, the engagement with the torsion coil spring may be negligible.
Furthermore, when it is desired to place importance on the stable stability of the spring, the number of reinforcing ribs provided on the lever body is increased so that a smaller spring accommodating part is defined by the arc-shaped peripheral wall part and the plurality of reinforcing rib parts. If the rotating range of the coil spring is reduced, or the gap between the lever side wall and the spring locking rib is reduced to reduce the movable range in the insertion / removal direction of the torsion coil spring, the torsion coil spring can move. The range can be reduced and the position stability can be improved.

Hereinafter, the chain tensioner lever of the present invention will be described with reference to the drawings.
Here, FIG. 1 is a schematic view of a chain transmission device assembled with a chain tensioner lever according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line AA in FIG. 3 is a rear perspective view of the lever main body shown in FIG. 1, FIG. 4 is an explanatory view showing a state where the torsion coil spring shown in FIG. 1 is in a pressing position, and FIG. FIG. 6 is an explanatory diagram of a state where the torsion coil spring shown is in the locking position, FIG. 6 is an explanatory diagram of a state where the torsion coil spring shown in FIG. 1 is in the locking release position, and FIG. It is a partial cross section figure which shows the state of the spring at the time of the assembly | attachment of the lever main body shown by FIG.

  A chain tensioner lever 100 according to an embodiment of the present invention shown in FIGS. 1 to 7 has a base end side of a resin-molded lever main body 110 that is rotatable on a mounting surface R of the engine main body by a pivot shaft P. It is supported by.

  As shown in FIGS. 1 and 2, the chain tensioner lever 100 has a shoe surface S formed along the longitudinal direction of the lever body 110 on the drive side sprocket SP1 attached to the crankshaft and the auxiliary shaft. The lever main body 110 is slidably contacted with the outer periphery of the slack side of the chain C spanned between the attached sprocket SP2 and the lever main body 110 is moved around the pivot axis P toward the chain C by the biasing force of the torsion coil spring 120. The shoe surface S presses the chain C to prevent it from loosening.

As shown in FIGS. 2 and 3, the lever main body 110 is provided with a lever peripheral wall portion 111 around the periphery, covered with a lever side wall portion 112 on the side opposite to the mounting surface, and opened on the mounting surface R side. doing.
The lever peripheral wall portion 111 includes a shoe surface side peripheral wall portion 111a having a shoe surface S for sliding the chain C, an anti-shoe side peripheral wall portion 111b opposite to the shoe surface S, and the shoe side peripheral wall portion 111a and the anti shoe. An arc-shaped peripheral wall portion 116 having an arc shape connected to the side peripheral wall portion 111b.
In addition, a plurality of reinforcing rib portions 113 (referred to as a central reinforcing rib portion 113a and a tail reinforcing rib portion 113b, respectively) are provided between the shoe surface side peripheral wall portion 111a and the anti-shoe surface side peripheral wall portion 111b with a space therebetween. Is provided.

As shown in FIG. 3, the pivot shaft P penetrates the spring accommodating portion 130 defined by the arc-shaped peripheral wall portion 116 on the lever side wall portion 112, the shoe surface side peripheral wall portion 111a and the central side reinforcing rib portion 113a. A boss 114 having a shaft hole 114 a is formed integrally with the lever side wall 112.
The end surface of the boss portion 114 facing the mounting surface R protrudes slightly toward the mounting surface R side from the lever peripheral wall portion 111, and when the lever main body 110 rotates, a portion other than the end surface of the boss portion 114 becomes the mounting surface R. The lever main body 110 can be smoothly rotated with respect to the pivot axis P by the boss portion 114 without rattling.
Further, the flange portion Pc formed on the pivot shaft P restricts the movement of the lever body 110 in the axial direction of the pivot shaft P.
The boss outer peripheral surface 114b of the boss portion 114 is formed concentrically with the shaft hole 114a, and the winding portion 121 of the torsion coil spring 120 is loosely fitted around the boss outer peripheral surface 114b.

The pressing arm portion 122 extending from one end of the winding portion 121 of the torsion coil spring 120 is bent at the tip end thereof toward the mounting surface R side at the pressing position 122a on the inner side surface of the shoe surface side peripheral wall portion 111a. It is touched.
Further, the support arm portion 123 extending from the other end of the wound portion 121 of the torsion coil spring 120 is inserted through the cutout region 116a formed in the arc-shaped peripheral wall portion 116, and the tip portion thereof is on the mounting surface R side. It is inserted into a spring mounting hole sh that is bent and drilled in the mounting surface R.

  As shown in FIGS. 1 and 2, in a state where the lever main body 110 is assembled to the mounting surface R, the torsion coil spring 120 has a resilient force caused by a torsion torque, and the lever main body around the pivot axis P is generated. 110 is urged to rotate counterclockwise in FIG. 1 and presses the outer peripheral surface of the chain C via the shoe surface S.

As shown in FIGS. 3 to 6, the arc-shaped peripheral wall portion 116 is formed with a notch region 116a in a range of about 60 ° with respect to the center of the shaft hole 114a, and the torsion coil spring 120 is supported in the notch region 116a. An arcuate engagement recess 116b for engaging and holding the support arm 123 is formed as a spring locking portion at the end of the arm 123 in the direction in which the elastic force acts.
The engaging recess 116b keeps the support arm 123 engaged with the engaging recess 116b in a state where the torsion coil spring 120 is assembled in the lever main body 110.
Thereby, the torsion coil spring 120 is prevented from coming out of the lever body 110 and dropping off before the operation of assembling the lever body 110 to the mounting surface R.

When the support arm 123 is removed from the engagement recess 116b and no torsional elastic force is generated in the torsion coil spring 120, the torsion coil spring 120 can be rotated to the locking position shown in FIG. It is.
That is, in this embodiment, the torsion coil spring 120 is rotatable within a certain range in a free state where the torsional spring force does not act on the torsion coil spring 120. It freely rotates in a range from a pressing position 122a that comes into contact with and presses the inner side surface of the side peripheral wall 111a and a locking position 122b that comes into contact with the inner side surface of the central reinforcing rib 113a that constitutes the spring accommodating portion 130. Is.

  In addition, a spring locking rib portion 115 projects from the shoe surface side peripheral wall portion 111a into the spring accommodating portion 130, and the torsion coil spring 120 is in a rotating range from the pressing position 122a to the locking position 122b described above. The torsion coil spring 120 is prevented from coming out of the spring accommodating portion 130 (see FIG. 2).

As shown in FIGS. 1 to 6, the spring locking rib portion 115 has a plate-like shape as a whole that substantially crosses the rotation range of the torsion coil spring 120, and the spring locking rib tip portion 115 a has a circular shape. It is arc-shaped and becomes narrower toward the tip, and is formed thicker in the insertion / removal direction of the torsion coil spring 120.
The spring locking rib portion 115 having such a shape prevents the torsion coil spring 120 from falling off the lever main body 110 even if the torsion coil spring 120 freely rotates by any moment, and the spring locking rib. Since the portion 115 is wide in the spring insertion / removal direction and has high rigidity with respect to the pulling direction of the torsion coil spring 120, the support arm portion 123 of the torsion coil spring 120 is temporarily attached to the torsion coil spring 120 when the lever body 110 is assembled. Even if a large tensile force is applied, the torsion coil spring 120 is reliably prevented from falling off and the lever main body 110 such as the spring locking rib 115 is prevented from being damaged.

In the chain tensioner lever 100 of this embodiment, the torsion coil 121 is pressed against the inner side surface of the central reinforcing rib portion 113a while the winding portion 121 of the torsion coil spring 120 is eccentric with respect to the boss portion 114 and the pressing arm portion 122 is pressed against the inner side surface of the central reinforcing rib portion 113a. When the spring 120 is biased to the lower left in FIG. 6, the tip of the pressing arm 122 can be moved from the rotation position 122b to the unlocking position 122c positioned further downward in FIG.
At the unlocking position 122c, the pressing arm portion 122 of the torsion coil spring 120 is out of the engagement range by the spring locking rib portion 115. At this position, the torsion coil spring 120 is attached to or detached from the spring accommodating portion 130. It becomes possible.

Next, the process of incorporating the torsion coil spring 120 and the process of assembling and mounting the chain tensioner lever 100 according to this embodiment on the mounting surface R will be described below.
First, when the torsion coil spring 120 is assembled into the lever main body 110, the torsion coil spring 120 is shifted to one side of the boss portion 114 as shown in FIG. Is inserted into the spring accommodating portion 130 at a position exceeding the position.
When the torsion coil spring 120 is accommodated in the spring accommodating portion 130, the support arm portion 123 of the torsion coil spring 120 is rotated in the direction of the shoe surface side peripheral wall portion 111a to support the engagement arm portion 123 in the engagement recess 116b of the notch region 116a. Are engaged, the pressing arm portion 122 of the torsion coil spring 120 is positioned at the pressing position 122a on the inner surface of the shoe surface side peripheral wall portion 111a. In this state, the torsional spring force acts on the torsion coil spring 120. Therefore, the torsion coil spring 120 does not rattle in the spring accommodating portion 130, and the pressing arm portion 122 of the torsion coil spring 120 is prevented from being engaged with the spring locking boss portion 115 and coming out. .

Further, since the support arm portion 123 of the torsion coil spring 120 is engaged and held in the engagement recess 116b of the notch region 116a, the torsion coil spring 120 does not come out of the lever body 110 and fall off.
Therefore, when it is necessary to temporarily stock the chain tensioner lever 100, the torsion coil spring 120 and the lever main body 110 are integrated so as to be stored and transported in this state. It becomes easy.

Further, when the chain tensioner lever 100 of this embodiment is assembled to the mounting surface R of the engine or the like, the supporting arm portion 123 of the torsion coil spring 120 incorporated in the lever main body 110 is engaged with the engaging recess in the vicinity of the mounting surface R. 116b and after the torsion coil spring 120 is inserted into the spring mounting hole sh provided on the mounting surface R, the pivot shaft P is inserted and screwed to complete the assembly operation.
In such assembling work, even if the support arm 123 of the torsion coil spring 120 is released from the operator's hand when the support arm 123 is in a state of being disengaged from the engagement recess 116b, As shown in FIG. 7, the spring locking rib portion 115 prevents the pressing arm portion 122 of the torsion coil spring 120 from coming out of the spring accommodating portion 130 and falling off, thereby reducing the complexity of the assembly work. The work can be continued easily without using a complicated nerve.

About the arrangement | positioning aspect of this latching position 122b and the latch release position 122c, it is possible not only to carry out by the method mentioned above but to take another method.
For example, since the inner diameter of the winding portion 121 of the torsion coil spring 120 usually has a considerable margin as compared with the diameter of the boss outer peripheral surface 114b, the winding of the torsion coil spring 120 is required when the torsion coil spring 120 is mounted. The pressing arm portion 122 is inserted with the portion 121 inclined to the boss portion 114 so that the pressing arm portion 122 is positioned as close as possible to the boss portion 114, and the pressing arm portion 122 of the torsion coil spring 120 is inserted into the tip of the spring locking rib portion 115. It is also possible to incorporate into the spring accommodating portion 130 through the unlocking position 122c (a position similar to the position shown in FIG. 6) that avoids the above.
It should be noted that when the torsion coil spring 120 is attached to the lever main body 110, the operator is forced to take a position or posture in which the torsion coil spring 120 cannot normally be taken. The torsion coil spring 120 is inserted and removed at a position exceeding the engaged rotation range.
As a result, in the operation of assembling the chain tensioner lever 100 to the assembly surface, the possibility that the torsion coil spring 120 will come out even if the torsion coil spring 120 is separated from the operator's hand during the operation is minimized. The operation of attaching the spring 120 to the lever main body 110 can be easily performed at the above-described locking release position 122c.

In addition, regarding the play provided between the inner diameter of the winding part 121 of the torsion coil spring 120 and the outer diameter of the boss part 114, the eccentric range of the torsion coil spring 120 increases as the play of the torsion coil spring 120 increases. Although it can be said that the movement to the above-described unlocking position 122c is facilitated, increasing the play increases the range of rattling of the torsion coil spring 120 and increases the instability of that position, so that the torsion coil spring 120 is increased. On the other hand, if the play of the torsion coil spring 120 is too small, the movement to the locking release position 122c described above cannot be performed smoothly, which hinders the mounting operation of the torsion coil spring 120. become.
In consideration of these, as shown in FIG. 6, the play of the torsion coil spring 120 is moved downward in the drawing while the push arm portion 122 side of the winding portion 121 is decentered to the maximum extent. When it is moved, that is, when the torsion coil spring 120 is moved together and its pressing arm portion 122 is separated from the spring locking rib portion 115 to the maximum extent, the pressing arm portion 122 engages with the spring locking rib portion 115. It is appropriate to make it move to a position outside the matching range.
The amount of play of the torsion coil spring 120 is combined with the size of the spring locking rib portion 115 that determines the range in which the pressing arm portion 122 is engaged, and the size of the chain tensioner lever 100 and the elasticity of the torsion coil spring 120 are Considering the force, etc., the balance between the possibility of falling out and the ease of wearing should be set to an optimum value in terms of comparative balance.

  Further, when the spring locking rib portion 115 is made of a synthetic resin that can be slightly deformed, for example, the spring locking rib portion 115 has an arcuate tip shape and approaches the end of the locking position 122b. The engagement force between the rib portion 115 and the pressing arm portion 122 of the torsion coil spring 120 is reduced so that the engagement force is applied to the engagement position 122b even though it is slight. A force may be applied to the torsion coil spring 120 at the locking position 122b where the locking force becomes very small, and the end of the spring locking rib 115 may be elastically deformed and pushed into the pressing arm 122, in this case the locking position. 122b and the lock release position 122c are basically the same position.

In the chain tensioner lever 100 according to the embodiment of the present invention obtained as described above, the lever main body 110 is opposed to the shoe surface side peripheral wall portion 111a on which the shoe surface S is formed and the shoe surface side peripheral wall portion 111a. A lever peripheral wall portion 111 composed of an anti-shoe surface side peripheral wall portion 111b, a shoe surface side peripheral wall portion 111a, and an arcuate peripheral wall portion 116 connecting the anti-shoe surface side peripheral wall portion 111b, and an anti-mounting surface side of the lever peripheral wall portion 111 A lever side wall portion 112 covering the shoe surface, a reinforcing rib portion 113 interposed between the shoe surface side peripheral wall portion 111a and the anti-shoe surface side peripheral wall portion 111b, and a penetrating shaft P extending from the lever side wall portion 112. A boss 114 formed with a shaft hole 114a and a boss outer peripheral surface 114b for loosely fitting the torsion coil spring 120, and a shoe surface side peripheral wall 111a. A spring engagement rib portion 115 that engages with the helical coil spring 120, and the torsion coil spring 120 presses against the inner surface of the shoe surface side peripheral wall portion 111 a and the winding arm portion continuously connected to the pressing arm portion 122. The boss of the boss portion 114 is provided in a spring accommodating portion 130 that includes a portion 121 and a support arm portion 123 that is supported on the mounting surface R and is partitioned by the shoe surface side peripheral wall portion 111a, the reinforcing rib portion 113, and the arc-shaped peripheral wall portion 116. The inner surface of the shoe surface side peripheral wall portion 111a is loosely fitted to the outer peripheral surface 114b via the winding portion 121 and the pressing arm portion 122 of the torsion coil spring 120 is urged by the torsional elastic force of the torsion coil spring 120. And a locking position 122b that contacts the inner surface of the reinforcing rib portion 113 when the torsion coil spring 120 does not have a resilient force and rotates in the direction opposite to the biasing direction. The spring locking rib 115 engages with the pressing arm 122 of the torsion coil spring 120 between the pressing position 122a and the locking position 122b to be twisted from the spring accommodating portion 130. By preventing the coil spring 120 from coming off, the possibility of the torsion coil spring 120 coming out and falling off during the mounting work of the torsion coil spring 120 on the mounting surface R can be eliminated, and the assembling work can be simplified. At the same time, when the torsion coil spring 120 is biased while pressing the pressing arm portion 122 of the torsion coil spring 120 against the inner surface of the reinforcing rib portion 113 in a state where the winding portion 121 is eccentric with respect to the boss portion 114, the spring engagement. It is possible to move to a locking release position 122c that is disengaged between the pressing position 122a and the locking position 122b engaged by the locking rib 115. Thus, the work of incorporating the torsion coil spring 120 into the lever main body 110 can be simplified and excellent workability can be exhibited.
Further, since the rigidity of the spring locking rib portion 115 is increased in the insertion / removal direction of the torsion coil spring 120 to increase its rigidity, it is possible to more reliably prevent the torsion coil spring 120 from slipping out and damage the spring locking rib portion 115. The effect is enormous.

DESCRIPTION OF SYMBOLS 100 ... Chain tensioner lever 110 ... Lever main body 111 ... Lever peripheral wall part 111a ... Shoe surface side peripheral wall part 111b ... Anti shoe surface side peripheral wall part 112 ... Lever side wall part 113 (113a) 113b) ... Reinforcement rib part 114 ... Boss part 114a ... Shaft hole 114b ... Boss outer peripheral surface 115 ... Spring locking rib part 115a ... Spring locking rib tip part 116 ...・ Arc-shaped peripheral wall portion 116a... Notch region 116b... Engagement recess 120... Torsion coil spring 121 .. winding portion 122... Press arm portion 122a .. press position 122b. Position 122c ... Unlocking position 123 ... Support arm part 130 ... Spring accommodating part P ... Pivot shaft bh ... Bolt hole sh · Spring mounting hole S · · · shoe surface C · · · chain R · · · mounting surface SP1 · · · drive sprocket SP2 · · · driven sprocket

Claims (4)

A shoe body that slides the chain is formed along the longitudinal direction, and a lever body that is rotatably supported by a pivot shaft that is erected on the mounting surface, and an interposition between the lever body and the mounting surface A tensioner lever for a chain comprising a torsion coil spring that presses the shoe surface against the chain,
The lever main body connects the shoe surface side peripheral wall portion forming the shoe surface, the anti shoe surface side peripheral wall portion facing the shoe surface side peripheral wall portion, the shoe surface side peripheral wall portion, and the anti shoe surface side peripheral wall portion. Any one of a lever peripheral wall portion composed of an arc-shaped peripheral wall portion, a lever side wall portion covering the side opposite to the mounting surface of the lever peripheral wall portion, the shoe surface-side peripheral wall portion, the anti-shoe surface-side peripheral wall portion, and the arc-shaped peripheral wall portion. A reinforcing rib part interposed between the two, a boss part standing from the lever side wall part and forming a shaft hole through which the pivot shaft passes and a boss outer peripheral surface loosely fitting the torsion coil spring; A spring locking rib portion protruding from the shoe surface side peripheral wall portion and engaging with the torsion coil spring;
The torsion coil spring includes a pressing arm portion that presses an inner surface of the shoe surface side peripheral wall portion, a winding portion that is connected to the pressing arm portion, and a support arm portion that is attached to the mounting surface. It is loosely fitted to the boss outer peripheral surface of the boss portion through the winding portion in the spring accommodating portion defined by the surface side peripheral wall portion, the reinforcing rib portion, and the arc-shaped peripheral wall portion,
When the pressing arm portion of the torsion coil spring is urged by the elastic force of the torsion coil spring, the elastic force acts on the pressing position that contacts the inner surface of the shoe surface side peripheral wall portion and the torsion coil spring. Without being rotated, it is arranged so as to be freely rotatable between the engaging position where it abuts against the inner surface of the reinforcing rib portion when rotated in the direction opposite to the urging direction,
The spring locking rib portion engages with the pressing arm portion of the torsion coil spring between the pressing position and the locking position to prevent the torsion coil spring from coming out of the spring accommodating portion,
When the torsion coil spring is biased while pressing the pressing arm portion of the torsion coil spring against the inner surface of the reinforcing rib portion in a state where the winding portion is eccentric with respect to the boss portion, the spring locking rib portion A chain tensioner lever, wherein the chain tensioner lever is movable to a lock release position that is disengaged between a press position and a lock position engaged with each other.   The chain tensioner lever according to claim 1, wherein a tip of the spring locking rib portion has an arc shape.   3. The chain according to claim 1, wherein the spring locking rib portion is formed to be wide in a loading / unloading direction of the torsion coil spring and narrow in a direction perpendicular to the rotation direction. 4. Tensioner lever. A part on the mounting surface side of the arcuate peripheral wall portion in which the notch region through which the support arm portion of the torsion coil spring that is locked to the mounting surface side is assembled and mounted on the mounting surface defines the spring housing portion Formed into
The engagement recess for engaging and holding the support arm portion of the torsion coil spring by the elastic force when the torsion coil spring is mounted on the lever body is formed at one end of the notch region. The chain tensioner lever according to claim 3.

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