JP2004044749A - Plunger stopper made of resin for ratchet type tensioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plunger stopper made of resins in which a pull-out operation of the plunger stopper can be simply achieved without damaging a ratchet mechanism of a ratchet type tnesioner and the rushing out of the plunger can be simply prevented in attaching work of the tensioner to an engine block and in attaching/detaching work of a chain or the like. <P>SOLUTION: The plunger stopper 10 made of resins is for temporarily stopping the rushing-out of the plunger 23 by being used for the ratchet type tensioner 20. A torsional torque absorption part 13 to absorb the torsional torque generated to a lug piece is formed between a forked stopping piece 11 inserted so as to be clamped between a housing body 22 and a ratchet claw body 24, in a state of straddling a spring 25 for the ratchet claw body in a recessed groove 22A and the lug piece 12 extended from the stopping piece 11 and protruded to the outside of the housing body 22. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an accessory of a ratchet type tensioner for applying an appropriate tension to a timing belt, a timing chain, and the like of a vehicle engine, and more particularly, to a plunger restraint for temporarily stopping the plunger from popping out using the ratchet type tensioner. About the tool.
[0002]
[Prior art]
A ratchet-type tensioner for suppressing vibration generated during traveling of a timing belt or a timing chain that transmits rotation between a crankshaft and a camshaft of an engine and maintaining proper tension is a plunger projecting from a housing body. Presses the back surface near the swinging end of the tensioner lever that is pivotally supported on the engine body side, so that the shoe surface of the tensioner lever slides on the slack side of the chain to apply tension. Has become.
[0003]
Therefore, as shown in FIG. 13, the plunger 33 is urged by a plunger spring 36 in the housing body 32 and protrudes to the outside so as to protrude and retract, and the ratchet pawl body shaft 34A provided in the housing body 32 swings. A conventional ratchet-type tensioner having a ratchet pawl body 34 freely supported and urged by a ratchet pawl spring 38 is fixed to an end of a shaft 34A of the ratchet pawl body protruding outside the housing body 32. When the ratchet type tensioner 31 is shipped or mounted on an engine block, the ratchet type tensioner 31 is engaged with the ratchet teeth 33B and the ratchet claws 34B as shown in FIG. At the same time, the stopper pin 39 is inserted into the pin insertion hole 37A of the outer plate 37, and the stopper pin 39 is The plunger 33 does not protrude from the housing main body 32 by abutting against the outer wall end surface 32A of the housing main body 32 or the stopper pin 39 against the stopper hole peripheral wall 32B formed in the housing main body 32 as shown in FIG. After being held as described above and attached to the engine block, the stopper pin 39 is removed (for example, see Patent Document 1).
[0004]
[Patent Document 1]
Japanese Patent No. 3226037 (page 2, FIGS. 5 to 10)
[0005]
However, such a conventional ratchet type tensioner 31 only requires an external plate 37 for making a hole for inserting the stopper pin 39 into the housing body 32 and for forcibly swinging the ratchet claw body 34. In addition, since a processing step of fixing the outer plate 37 to the shaft 34 is required, not only the manufacturing burden and manufacturing cost are increased, but also the stopper pins 39 are inserted into the pin insertion holes 37A of the outer plate 37 so that the When the plunger 33 is prevented from popping out, if the gap between the housing main body 32 and the engine block side is small, the stopper pin 39 contacts and interferes with the engine block side, making it difficult to insert and remove the stopper pin 39. For mounting work, removing and attaching chains There is a problem that can not be easily performed, such as work or.
[0006]
Therefore, in order to solve the above-described problem, as a plunger stopper 41 of the ratchet type tensioner 40 developed by the present applicant and already applied for a patent, a housing of the ratchet type tensioner 40 as shown in FIGS. A bifurcated stop piece 41A inserted so as to be sandwiched between the housing body 42 and the ratchet claw body 44 in a state of straddling the ratchet claw body spring 45 in the concave groove 42A formed in the main body 42; There is a knob provided with a knob 41B extending from the stopper 41A to the outside of the housing body 42 and projecting. Here, reference numeral 43 shown in FIGS. 16 and 17 is a plunger that protrudes and retracts from the housing body 42, reference numeral 43A is a ratchet tooth engraved on the outer peripheral surface of the plunger 43, and reference numeral 42B is A mounting hole for mounting the housing body 42 to the engine block.
[0007]
[Problems to be solved by the invention]
However, as shown in FIG. 18, the plunger stopper 41 of the ratchet type tensioner 40 developed by the present applicant is pulled out of the state where the knob 41B is inserted and twisted, as shown in FIG. There is a danger that the fork-shaped stopping piece 41A integrally formed from above will be in a sandwiching state in which the ratchet claw spring 45 is screwed, and the stopping piece 41A will be pulled up together with the ratchet claw body spring 45 to damage the ratchet mechanism. In this case, a contrivance has been made to easily perform the pull-out operation of the plunger stopper 40.
[0008]
Therefore, an object of the present invention is to solve the above-described problems of the related art, and it is possible to easily achieve a pull-out operation of a plunger stopper without damaging a ratchet mechanism of a ratchet type tensioner. In addition, an object of the present invention is to provide a ratchet type tensioner plunger stopper which can easily prevent the plunger from popping out in the operation of attaching the tensioner to the engine block, attaching and removing the chain, and the like.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a housing body attached to a vehicle engine block, a plunger which is spring-biased from the housing body and projects forward to the outside, and a housing body which opens toward the plunger. And a ratchet pawl body which is arranged in the concave groove and swings in a pivotally supported state, and a ratchet pawl body spring which urges the ratchet pawl body to engage with the ratchet teeth on the outer peripheral surface of the plunger. In order to temporarily stop the plunger from popping out using the ratchet type tensioner, the plunger is sandwiched between the housing body and the ratchet pawl while straddling the ratchet pawl spring in the concave groove. A resin plunger stopper having a bifurcated stop piece inserted into the housing and a knob piece extending from the stop piece to the outside of the housing body and projecting therefrom. The knob piece twist to absorb torque generated in torsion torque absorption site is formed at least between the knob piece with stop pieces.
[0010]
Note that the specific form of the “torsion torque absorbing portion” in the present invention is as follows. Any form, such as a linear form, a curved form, or a combination thereof, may be used as long as the form can greatly reduce the torsional torque transmission.
[0011]
[Action]
The plunger stopper of the ratchet type tensioner according to the present invention, when trying to temporarily stop the plunger from popping out, while holding the knob by hand or the like, while holding the knob with a forked-shaped stopper extending from the knob. By inserting the bracket so as to be sandwiched between the housing body and the ratchet claw body in a state of straddling the spring for the ratchet claw body in the concave groove of the housing body, the stopping piece is formed with the ratchet claw body and the ratchet teeth. Is forcibly maintained to prevent the ratchet claw body from swinging, so that even if the plunger is spring-biased from the housing body and tries to jump out, the jumping out is completely stopped.
[0012]
Also, when releasing the stopped state of the plunger, the knob is pulled up by hand or the like so that the locking piece integrally formed with the knob does not damage the ratchet pawl spring, and the housing body is not damaged. Of the plunger which is spring-biased from the housing body to allow the plunger to protrude forward. That is, when the torsion torque absorbing portion for absorbing the torsional torque of the knob is formed at least between the knob and the stopper, the knob of the plunger stopper is pulled out to twist. However, since the torsion absorbing portion formed between the gripping piece and the stopping piece can absorb such torsion and block the propagation to the stopping piece, the bifurcated stopping piece has a ratchet claw body. Can be smoothly pulled up from the vicinity of the spring.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
An example which is an embodiment of the present invention will be described with reference to FIGS.
First, as shown in FIG. 1, a ratchet type tensioner 20 that applies the resin plunger stopper 10 of the present invention as a temporary stopper for a plunger includes a housing main body 22 attached to a vehicle engine block (not shown). A plunger 23 which is spring-biased from the housing body 22 and protrudes to the outside, and a ratchet claw arranged in the concave groove 22A of the housing body 22 which opens toward the plunger 23 and swings in a pivotally supported state. Body 24 and a ratchet pawl spring 25 for urging the ratchet pawl 24 into engagement with the ratchet teeth 23A on the outer peripheral surface of the plunger, and is suitable for a timing belt, a timing chain, etc. of a vehicle engine. It is designed to apply a great tension.
In addition, 22B in FIG. 1 is a mounting hole for mounting the housing main body 22 to the engine. Further, since the basic tensioner function of such a ratchet type tensioner 20 is the same as that of the conventional ratchet type tensioner 41 described above, the description of the detailed structure, operation, function, and the like will be omitted.
[0014]
Therefore, the resin plunger stopper 10 according to one embodiment of the present invention is used to temporarily prevent the plunger 23 from jumping out of the ratchet type tensioner 20 as described above, and will be described in detail below. I do.
The resin-made plunger stopper 10 of this embodiment is sandwiched between the housing body 22 and the ratchet pawl 24 while straddling the ratchet pawl spring 25 in the concave groove 22A of the ratchet type tensioner 20. Is integrally formed with a forked stopper 11 inserted as described above, and a knob 12 extending from the stopper 11 and protruding outside the housing body 22.
[0015]
As shown in FIG. 2, the resin plunger stopper 10 of this embodiment has a bifurcated restraint because the outer crotch interval W1 of the stopper piece 11 is slightly larger than the groove width W2 of the concave groove 22A. Since the piece 11 is inserted between the housing body 22 and the ratchet pawl 24 by compressing the outer crotch interval W1, the spring-biased plunger is pushed back to move the plunger between the housing body 22 and the ratchet pawl 24. Even if the generated holding force of the stopping piece 11 is released, a widening force in the groove width direction acts between the inserted stopping piece 11 and the concave groove 22A, and the stopping piece 11 is moved into the concave groove 22A of the housing body 22. As long as it is not intentionally pulled out of the stopper 11, the stopper 11 can be completely prevented from falling off.
[0016]
On the other hand, the inner crotch interval of the stop piece 11 is slightly larger than the outer diameter of the ratchet pawl spring 25, and when the stop piece 11 is inserted into the concave groove 22A, the ratchet pawl spring is used. 25, so that it does not become an obstacle for insertion.
Note that the phantom line in FIG. 3 indicates the outline of the concave groove 22 </ b> A in the housing main body 22. As for the material of the plunger stopper 10, it is more preferable to adopt a synthetic resin such as a polyamide resin and a polyacetal resin from the viewpoint of a molding burden and a molding cost.
[0017]
The most characteristic feature of the resin plunger stopper 10 of the present embodiment is that the torsion torque absorbing portion 13 absorbs the torsion torque of the knob 12 generated when the knob 12 is pulled out to twist. Is formed between the knob piece 12 and the stop piece 11, and when the knob piece 12 is pulled out so as to be twisted, the torsional torque absorbing portion 13 absorbs such torsional torque. The propagation to the stop piece 11 is blocked, and the inserted stop piece 11 can be smoothly pulled up from the vicinity of the ratchet pawl spring 25.
[0018]
In this way, when trying to temporarily stop the plunger 23 from jumping out of the ratchet type tensioner 20, the fork-shaped stopping piece 11 extending from the holding piece 12 while holding the holding piece 12 by hand or the like. Is inserted between the housing main body 22 and the ratchet claw body 24 in a state of straddling the ratchet claw body spring 25 in the concave groove 22A of the housing main body 22 so that the stopping piece 11 is Since the engagement state between the ratchet pawl 24 and the ratchet teeth 23A is forcibly maintained to prevent the ratchet pawl 24 from swinging, even if the plunger 23 is spring-biased from the housing body 22 and tries to fly out, The pop-out can be completely stopped. On the other hand, when releasing the stopped state of the plunger 23, the knob 12 is pulled by hand or the like to twist. Even if the stop piece 11 is pulled out from the recessed groove 22A of the housing body 22, the torsion torque absorbing portion 13 absorbs such a torsional torque and blocks the propagation to the stop piece 11, so that the stop piece 11 is ratcheted. The ratchet mechanism 25 is smoothly pulled up from the vicinity of the ratchet pawl spring 25 without the possibility of causing the ratchet mechanism to be in a pinched state in which the pawl spring 25 is twisted and causing a failure in the ratchet mechanism.
[0019]
The resin-made plunger stopper 10 of the present embodiment obtained as described above is formed by a conventional boring process for inserting the stopper pin 39 into the housing body 32 and the ratchet pawl body 34 is forcibly swung. Not only does not require an external plate 37, but also does not require a processing step of fixing the external plate 37 to the shaft 34, the protrusion of the plunger 23 can be easily prevented, and the stopped state of the plunger 23 can be reduced. When releasing, the stopping piece 11 can be smoothly pulled up from the vicinity of the ratchet pawl spring 25, so that the operation of attaching the tensioner to the engine block, attaching the chain, and removing the ratchet can be performed by the ratchet mechanism including the ratchet pawl spring 25 or the like. Can be easily achieved without damaging the tensioner itself. Etc. can be greatly reduced granulation burden and manufacturing costs, the effect is significant.
[0020]
Next, FIGS. 3 to 12 show modified examples of the resin plunger stopper 10 of this embodiment. That is, the resin plunger stopper 10 shown in FIGS. 3 and 4 is obtained by deforming the shape of the knob 12. The resin plunger stopper 10 shown in FIGS. 5 to 7 is obtained by deforming the shape of the torsional torque absorbing portion 13. In the resin plunger stopper 10 shown in FIGS. 8 to 12, the knob 12 is formed of a linear body in the same manner as the torsion torque absorbing portion 13, so that the knob is pulled out from the inserted state. Even in such a case, the twisting torque is not generated as much as possible on the knob piece 12 itself.
[0021]
In addition, regarding the specific form of the torsional torque absorbing portion 13 described above, the gripping piece 12 or the gripping piece 12 from the gripping piece 12 to the restraining piece 11 is less rigid than the rigidity due to the shape of the restraining piece 11. As long as the torsion torque transmission can be largely suppressed, any other forms than those shown in FIGS. 1 to 12 may be used.
[0022]
In the above-described embodiment, the case where the ratchet type tensioner is applied to the hydraulic type tensioner 20 has been described. However, the plunger stopper 10 of the present invention is also applicable to a no-back type ratchet type tensioner having no backlash. Can also be applied.
[0023]
【The invention's effect】
As described above, the resin plunger stopper of the ratchet type tensioner according to the present invention, the ratchet type tensioner and the housing main body in a state of straddling the spring for the ratchet claw body in the concave groove formed in the housing main body of the ratchet type tensioner. By providing a bifurcated stop piece inserted so as to be sandwiched between the ratchet claw body and a knob piece extending from the stop piece and projecting to the outside of the housing body, the plunger is prevented from popping out. In this case, the stop piece extending from the knob piece forcibly keeps the engagement state between the ratchet claw body and the ratchet teeth to prevent the ratchet claw body from swinging, so that the protrusion of the plunger is completely stopped. On the other hand, when releasing the restraining state of the plunger, pull the knob piece by hand or the like and pull the restraining piece out of the groove of the housing. Since the free movement of the lancer can be allowed, the work of attaching the tensioner to the engine block, the work of attaching and detaching the chain, and the like can be easily achieved. Since there is no need for drilling or a shaft 34 for fixing the means to the housing body 32, the manufacturing burden and manufacturing cost of the tensioner itself can be greatly reduced.
[0024]
In addition, since the stopper piece extending from the knob piece is inserted into the concave groove of the housing body, the gap between the housing body 32 and the engine block side as in the related art is small, and the stopper pin 39 is moved to the engine block side. Even in a tensioner installation environment where it is difficult to insert and remove the stopper pin 39 due to contact interference, the stopper can be easily inserted and removed, so that the operation of attaching the tensioner to the engine block and removing the chain can be easily performed. .
[0025]
And, since the torsion torque absorbing portion for absorbing the torsional torque of the knob piece is formed at least between the knob piece and the stop piece, the knob is pulled out from the inserted state so as to twist. Even if there is, the torsion absorbing portion formed between the knob piece and the stop piece can absorb such torsion and block propagation to the forked stop piece, so that the stop piece has a ratchet claw. The inserted stopper can be pulled up smoothly from the vicinity of the ratchet pawl spring without causing the ratchet mechanism to malfunction due to the pinching state in which the body spring is screwed in, so pull out the plunger stopper. The operation can be easily achieved.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a usage mode of a resin plunger stopper of a ratchet type tensioner according to the present invention.
FIG. 2 is an enlarged view of a resin plunger stopper according to the present invention.
FIG. 3 is a view showing a first modification of the resin plunger stopper according to the present invention.
FIG. 4 is a view showing a second modification of the resin plunger stopper according to the present invention.
FIG. 5 is a view showing a third modification of the resin plunger stopper according to the present invention.
FIG. 6 is a view showing a fourth modification of the resin plunger stopper according to the present invention.
FIG. 7 is a view showing a fifth modification of the resin plunger stopper according to the present invention.
FIG. 8 is a view showing a sixth modification of the resin plunger stopper according to the present invention.
FIG. 9 is a view showing a seventh modification of the resin plunger stopper according to the present invention.
FIG. 10 is a view showing an eighth modification of the resin plunger stopper according to the present invention.
FIG. 11 is a view showing a ninth modification of the resin plunger stopper according to the present invention.
FIG. 12 is a view showing a tenth modification of the resin plunger stopper according to the present invention.
FIG. 13 is a perspective view showing a ratchet type tensioner as a first conventional example.
FIG. 14 is a plan view showing a ratchet type tensioner as a second conventional example.
FIG. 15 is a side sectional view of the ratchet type tensioner shown in FIG. 14;
FIG. 16 is a perspective view showing a ratchet type tensioner as a third conventional example.
FIG. 17 is a side sectional view of the ratchet type tensioner shown in FIG. 16;
FIG. 18 is an enlarged view of a main part of the ratchet type tensioner of FIG. 16, showing a state in which the plunger stopper is pulled out.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Plunger stopper 11 ... Restriction piece 12 ... Knob piece 13 ... Torsion torque absorbing part 20 ... Ratchet type tensioner 22 ... Housing body 22A ... Recessed groove 22B ... · Mounting hole 23 ··· Plunger 23A ··· Ratchet teeth 24 ··· Ratchet claw body 25 ··· Spring 37 for ratchet claw body ··· External plate 39 ··· Stopper pin

Claims (1)

A plunger, which is spring-biased from the housing main body and protrudes outward, is provided in a housing main body attached to the vehicle engine block, and a plunger which is disposed in a concave groove of the housing main body opening toward the plunger. Using a ratchet-type tensioner composed of a swinging ratchet claw body and a ratchet claw spring for urging the ratchet claw body into engagement with the ratchet teeth on the outer peripheral surface of the plunger, the plunger is temporarily ejected. Bifurcated stop piece which is inserted so as to be sandwiched between the housing body and the ratchet pawl while straddling the ratchet pawl body spring in the concave groove, and the stop piece. And a knob protruding from the housing body to protrude from the housing body.
A resin plunger stopper for a ratchet type tensioner, wherein a torsion torque absorbing portion for absorbing the torsional torque generated in the knob piece is formed at least between the knob piece and the stopper piece.

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