CN1928392A - Inner ratchet wheel fastening device - Google Patents

Abstract

The invention discloses a tension device with inner paw wheel, not only with mechanism of preventing piston moving back but also limiting the figure dimension, comprising shell 1 formed the hydraulic cylinder (1a); tube-shaped piston 2 with floor, which can slide freely in hydraulic cylinder in virtue of oil pressure; circular tube with rim (3), which is pricked up from the floor of hydraulic cylinder and of which said piston is mounted with the outside freely; return spring (4) in the circular tube with rim, which can push the piston to the convex direction; paw wheel mechanism preventing piston moving back. The paw wheel mechanism is made of containing groove (18) for locating ring formed in the inner part of piston; multiple circular grooves (21) formed on the outer part of the circular tube with rim in distance; locating ring (24) embedded between containing groove and circular groove.

Description

Inner ratchet wheel fastening device

Technical field

The present invention relates to prevent the tension device of the hydraulic type that the transmission chain bar is lax.

Background technique

Volume be suspended on the sprocket wheel and the situation of transferring power under, with the chain that a plurality of chain links connect and compose, the linking department wearing and tearing of each chain link can be extended.If as the trailing wheel that drives two-wheeled motor vehicle, reveal the roller chain that extension is rolled up in the outside, can deal with elongation by the position of adjusting sprocket wheel, but, under the situation of the timing chain that the picture engine interior uses, installation tensioner prevents the excess tension that is accompanied by the shake of elongation and is accompanied by shake.

Figure 11 represents general tension device in the past, comprise shell (a) and be slidably disposed on plunger (b) on this shell (a), by the grease chamber (d) in being formed on this plunger (b) sends into working oil (c) from the outside, plunger (b) is outstanding via the disc spring (e) that is built in the grease chamber (d).Thereby, be that the nutted rod (h) that swing at the center is boosted with axle (g), give the tension force of lax chain (f) with appropriateness.Otherwise when when chain (f) effect of going up has big tension force, closure of check ring stops retreating of plunger (b).Like this, chain (f) is remained on the state that suitable tension force effect is always arranged.

But, in the tension device in the past, corresponding to the tension force that affacts chain (f), plunger (b) is outstanding repeatedly, return motion (vibration), absorb to impact, still, when chain (f) has bigger when lax, plunger (b) is also outstanding greatly, and the ratchet action is in case outstanding words just can not retreat.And, be accompanied by the pulsation of chain, stop impact by the oil pressure of supporting plunger and between plunger and as the viscous damping power of the oil film between the sliding eye of Spielpassung.The rounded cross section of the plunger in past (mouth) has very big influence between the film area of outer circumferential face to viscous damping power.

Like this, give the tension force of lax chain (f) with appropriateness, otherwise, when big tension force affacts on the chain (f), stoping retreating of plunger (b), chain (f) always is in the state of the tension force effect of appropriateness.But, when additional excessive tension force, stand fast in order to make plunger, be necessary to be equipped with the mechanism that prevents that this plunger from retreating, still, as shown in figure 11, under situation about this mechanism that prevents that plunger from retreating being installed on the shell, the overall dimensions of device can enlarge.

On the other hand, will prevent that the mechanism that this plunger retreats is arranged under the situation of stretcher enclosure, it is big that the external diameter of this shell can become.That is, for pack into positioning ring and and then guarantee its stationary plane, be necessary the fluting, under the situation of the peripheral part that positioning ring is encased in plunger, be necessary to have stop and be inserted in the shell with the cylindrical body of stationary plane on this peripheral part, therefore, it is big that the diameter of shell must become.In addition, under the situation of slotting on the shell, in order to ensure thickness, it is big that the external diameter of shell can become direct.

Positioning ring is being encased under the situation of perimembranous in the plunger, can increasing the external diameter of shell.But, be necessary to guarantee to be used to guarantee to release the insertion space of spring of the elastic force of plunger.In the past, be encased in the internal diameter of spring, so the external diameter of the bar that has locking groove of positioning ring is also little, because the cause of intensity and surface pressure prevents that the power of allowing that retreats from can diminish owing to dwindle the external diameter of positioning ring.As this inner ratchet wheel fastening device, " chain stretching device " of opening 2001-82558 number according to the spy is known.

In this " chain stretching device ", the oil hydraulic cylinder that plunger can be encased in with freely swinging shell is indoor, between the safety check and plunger of the bottom of the oil hydraulic cylinder chamber of packing into, pack into the bar guider of tubular, utilize Returnning spring to push the flange that end thereafter is inserted into the front end of the bar in this bar guider, give the high-lighting of plunger outward portion direction.On the interior week of the front end of bar guider, form the guiding groove that can hold positioning ring that a part cuts off, at an end of this guiding groove perpendicular end surface is set, form inclined end face at the other end.On the periphery of bar, equally spaced form a plurality of circumferential grooves, second conical surface in the interior week that is formed on this circumferential groove is contacted, the amount of returning of restriction plunger with positioning ring on being coupled to aforementioned inclined end face.

That is, in this chain stretching device, release means, thin bar and bar guider are set, installing and locating ring (locating clip) between bar and bar guider in the internal diameter of this spring as plunger.And, because the groove with stationary plane of fixing this ring is arranged on the interior perimembranous of the peripheral part of bar and bar guider, because this is former thereby adopt the little positioning ring of external diameter, the surface pressure of positioning ring groove increases, and exists the very big problem of stopping power when plunger is retreated.

The content of invention

Like this, the tension device in past exists aforesaid problem.Problem to be solved by this invention is exactly these problems, and its objective is provides a kind of have anti-locking mechanism of structure that the plunger that adopts positioning ring retreats and the inner ratchet wheel fastening device that suppresses the boundary dimension of shell.

According to internal clickwork tension device of the present invention, by constituting: the shell that forms oil hydraulic cylinder with the bottom, the plunger of the tubular that the end is arranged that in this oil hydraulic cylinder, can be free to slide by oil pressure, hold up from the end of oil hydraulic cylinder and described plunger can be sleeved on the cylindrical body of the band edge on its periphery with being free to slide, with with the Returnning spring of this plunger in the mode that projected direction loads is contained in the cylindrical body of band edge, prevent the ratchet mechanism that this plunger retreats; This ratchet mechanism is by constituting with the bottom: be formed on the positioning ring receiving groove of the interior perimembranous of plunger, be formed on a plurality of circumferential grooves on the tube portion periphery of band edge cylindrical body with certain interval, be embedded in the receiving groove of positioning ring and the positioning ring between the circumferential groove.

Utilize this structure, this ratchet mechanism under positioning ring is fixed to state in the positioning ring receiving groove, is moved upward at the tube portion periphery of the band edge cylindrical body permission plunger that slides when plunger is outstanding, when applying impacting force on plunger, positioning ring plays a part to prevent plunger to retreat.Here,, can strengthen the external diameter of positioning ring to greatest extent, the area of contact of widening positioning ring and positioning ring receiving groove, the restraint when the increase plunger retreats by in plunger, disposing positioning ring between week and the band edge cylindrical body periphery.

Preferably, this positioning ring receiving groove, the line footpath of its depth ratio positioning ring is big, with its upper end as the plane of inclination that tilts upward towards central shaft, its lower end is as the vertical surface with respect to central shaft, and the circumferential groove of band edge cylindrical body is made of the conical surface that the plane of inclination of fixed groove with the arc surface that is formed on downside and the maximum diameter peripheral part from this arc surface to the top forms.In addition, preferably, positioning ring adopts elasticity with piano string etc., has a high-intensity material simultaneously.By this structure, when plunger was outstanding, positioning ring was fixed on the lower end of positioning ring receiving groove reliably, and with tube portion periphery hole enlargement and the undergauge of band edge cylindrical body, smoothly slide, be moved upward repeatedly by one side for one side.

In addition, the degree of depth of groove and the line of ring footpath should make it to have clearance with estimation error interior.The degree of depth of the fixed groove of the peripheral part of band edge cylindrical body must exceed the over half of the line footpath that is embedded in the positioning ring in this fixed groove, and the part that exceeds when plunger is outstanding hangs on the receiving groove, and what have that ring can rise reliably colludes the extension surplus.In addition, the outstanding resistance that produces by the positioning ring hole enlargement must be littler than the power of the Returnning spring that plunger is released.

The back-up ring that is fixed the lip part of band edge cylindrical body is coupled on the bottom periphery of this oil hydraulic cylinder, can prevents the come-up of band edge cylindrical body.By this structure, can simplify the operation of packing into of band edge cylindrical body.

According to inner ratchet wheel fastening device of the present invention, because at the internal diameter of plunger and have installing and locating ring between the peripheral part of band edge cylindrical body of external diameter in small gap, so, do not strengthen the external diameter of shell, on the other hand, the positioning ring diameter does not dwindle yet.Thereby, can prevent retreating of plunger by the positioning ring between positioning ring receiving groove and band edge cylindrical body.

In addition,, make it on the bottom surface of oil hydraulic cylinder, to hold up because the back-up ring that the utilization of band edge cylindrical body is coupled on the periphery of oil hydraulic cylinder bottom is fixed, so, can not float and stable the time, also can the occurrence positions skew.

Description of drawings

Fig. 1 is the longitudinal section of expression according to the embodiment of inner ratchet wheel fastening device of the present invention;

Fig. 2 is the planimetric map of expression according to the installment state of inner ratchet wheel fastening device of the present invention;

Fig. 3 is the longitudinal section of expression according to plunger of the present invention;

Fig. 4 is the sectional view of the A part of presentation graphs 2 enlargedly;

Fig. 5 is the longitudinal section of expression according to band edge cylindrical body of the present invention;

Fig. 6 is that the 6-6 of Fig. 4 is to view;

Fig. 7 is the sectional view of the B part of presentation graphs 5 enlargedly;

Fig. 8 is a part longitudinal section of representing the underpart of tension device of the present invention enlargedly;

Fig. 9 is the planimetric map of Fig. 8;

Figure 10 is the sectional view of the C part of presentation graphs 1 enlargedly;

Figure 11 is the part longitudinal section side view of the user mode of the traditional tension device of expression.

Embodiment

Inner ratchet wheel fastening device according to an embodiment of the invention, shown in Fig. 1 and 2, comprise: the shell 1 that forms cylindric oil hydraulic cylinder 1a as the die casting member made, be contained in the plunger 2 in this oil hydraulic cylinder 1a, hold up from the end of oil hydraulic cylinder and this plunger 2 can be sleeved on band edge cylindrical body 3 on its periphery with being free to slide, be configured in the Returnning spring 4 in this band edge cylindrical body 3, prevent the ratchet mechanism that this plunger retreats.Shell 1 has and forms assembly department 14a, the 14b that is installed to the mounting hole of using on the engine cylinder-body 5.

Shown in 3, in the upper end portion of this plunger 2, form with what ェ ャ-De ロ-6 (air director) was pressed into and be pressed into hole 15, simultaneously, at upper end portion periphery formation fixed groove 16.The anti-front end that flies out plate 11 that is installed on the spring lock-joint is fixed on this fixed groove 16, is embedded in the interior plunger 2 of oil hydraulic cylinder 1a of shell 1, owing to the elastic force of Returnning spring 4 can not fly out (with reference to Fig. 1 and Fig. 2).Thereby under situation about tension device being installed on the engine cylinder-body 5, plunger 2 can not given prominence to.

This plunger 2 has the space 17 that band edge cylindrical body 3 embeds in inside, form positioning ring receiving groove 18 in interior all underparts in this space 17.This positioning ring receiving groove 18 as Fig. 4 represents enlargedly, has the width of regulation, and simultaneously, upper end 29 tilts with angle [alpha] upward towards axis, and the depth D of positioning ring receiving groove 18 is bigger than the line footpath of the positioning ring of describing later 24.

Shown in Fig. 5 and 6, band edge cylindrical body 3 has the lip part 19 slightly littler than the bore of oil hydraulic cylinder 1a in the lower end, on the periphery of tube portion 20, forms circumferential groove 21,21 with certain spacing ...The oilhole 22,22 of slotted hole is set in the underpart of tube portion 20 ..., at the upper end of lip part 19 configuration back-up ring 23.Shown in Fig. 7 amplified, circumferential groove 20 had circular-arc fixed groove 25 and the conical surface 28 that positioning ring 24 can contact with fitting together perfectly.Flexible and the high-intensity piano string of these positioning ring 24 apparatus forms.

As shown in Figure 1, the plunger 2 of Xing Chenging is embedded in the oil hydraulic cylinder 1a of shell 1 in a manner described, and band edge cylindrical body 3 is embedded in the space 17 in the plunger 2.Hold Returnning spring 4 in the space in band edge cylindrical body 3, load the elastic force that pushes away on the plunger 2.Here, shown in Fig. 8 and 9, the lip part 19 of band edge cylindrical body 3 is embedded into by back-up ring 23 at the end of oil hydraulic cylinder, with this band edge cylindrical body 3 can not fix from the mode that cylinder bottom is floated.Band edge cylindrical body 3 is because the impacting force that is produced by oil pressure in the course of action of the tension device of oil pressure effect affacts on the lip part 19, so can not float.But, the small vibration when the engine start that oil pressure does not act on and when carrying, the surface friction drag of positioning ring 24 can make band edge cylindrical body 3 come-ups when plunger is outstanding.In order at this moment not make it come-up, use the back-up ring 13 of compacting lip part 19.The external diameter of this back-up ring 13 is bigger than the bore of the oil hydraulic cylinder of shell 1, by the elastic force of back-up ring 13, fixed with the frictional force in oil hydraulic cylinder aperture.This prevents the power that floats, is several times of the buoyancy that produced by positioning ring 24.Owing to utilize the surface friction drag of back-up ring 13 to prevent buoyancy, so back-up ring for as being pressed into of elastomeric back-up ring 13, does not utilize the power littler than being pressed into of rigid body just can assemble with the processing of groove on the bore of oil hydraulic cylinder.

Ball seat 9 is installed, in the upper end of this ball seat 9 configuration check ball 7, the outlet of stopping up oil circuit 26 in the hole on the end of the oil hydraulic cylinder 1a that is located at shell 1.From the end of oil hydraulic cylinder outstanding ball seat 9 and check ball 7, cover with spherical cap 8, in addition, check ball 7 compresses the outlet of oil circuit 26 by ball spring 10.

When chain elongation plunger 2 is given prominence to, the working oil that in oil circuit 26, flows, to push away on the check ball 7, from being formed on the otch 27,27 on the spherical cap 8 ... flow in the oil hydraulic cylinder, the part of working oil flows through the oilhole 22,22 in the tube portion 20 that is formed on band edge cylindrical body 3 ... in the gap of intrusion plunger 2 and oil hydraulic cylinder inner peripheral surface and the gap of plunger 2 and tube portion 20, finish lubrication.Otherwise, when being pushed back, when check ball 7 is closed oilhole 26,, can prevent retreating of plunger 2 by the ratchet mechanism action when the big load of effect on plunger 2.

Ratchet mechanism is made of the positioning ring receiving groove 18 and the circumferential groove 21 of subtend shown in Figure 10 and the positioning ring 24 that is inlaid in this circumferential groove periphery.The circumferential groove 21 of the peripheral part of band edge cylindrical body 3 has and conical surface 28 and fixed groove 25, so that can slide at plunger 2 positioning ring 24 when projected direction moves.That is, conical surface 28 and circular-arc fixed groove 25 form continuously, when locating slot 24 from fixed groove 25 along conical surface 28 when moving, its external diameter increases.

The upper end of positioning ring receiving groove 18 has the angle [alpha] with respect to the axle center, forms greatlyyer with respect to the angle beta in axle center than fixed groove 25.In Figure 10, α=60 °, β=45 °, but also can α＞β, α＞45 °, the desirable value of the braking force when retreating according to plunger changes.The lower end is the right angle with respect to the axle center of plunger, when plunger is outstanding, tangles positioning ring 24 with the lower end 23 that constitutes this right angle face, constitutes conical surface 28 risings of an integral body along the circumferential groove 21 of band edge cylindrical body 3 by plunger 2 and positioning ring 24, and plunger 2 is outstanding.

The depth D of the positioning ring receiving groove 18 of perimembranous in the plunger is as long as the line footpath than positioning ring 24 is big when positioning ring 24 is positioned at the outer circumferential face of band edge cylindrical body 3.Be formed on the degree of depth of making circular-arc fixed groove 25 on the outer circumferential face of band edge cylindrical body 3, line footpath over half that surpasses positioning ring 24, with in the positioning ring receiving groove 18 that when plunger is outstanding, is hooked on plunger 2, to have this positioning ring 24 surplus of colluding extension that can rise reliably be condition.In addition, the outstanding resistance that causes with the hole enlargement power by positioning ring is a condition less than the Returnning spring masterpiece that plunger 2 is released.

Claims (3)

1. inner ratchet wheel fastening device, it is characterized in that, this tension device is by constituting with the bottom: the shell that forms oil hydraulic cylinder, the plunger of the tubular that the end is arranged that in this oil hydraulic cylinder, can be free to slide by oil pressure, hold up from the end of oil hydraulic cylinder and described plunger can be sleeved on the cylindrical body of the band edge on its periphery with being free to slide, with with the Returnning spring of this plunger in the mode that projected direction loads is contained in the cylindrical body of band edge, prevent the ratchet mechanism that this plunger retreats; This ratchet mechanism is by constituting with the bottom: be formed on the positioning ring receiving groove of the interior perimembranous of plunger, be formed on a plurality of circumferential grooves on the tube portion periphery of band edge cylindrical body with certain interval, be embedded in the receiving groove of positioning ring and the positioning ring between the circumferential groove.

2. inner ratchet wheel fastening device as claimed in claim 1, above-mentioned positioning ring receiving groove, its degree of depth is greater than the line footpath of positioning ring, with the plane of inclination that forms on it towards central shaft tilts upward, its lower end is the face vertical with respect to central shaft, and the circumferential groove of band edge cylindrical body is made of the conical surface that fixed groove with arc surface that is formed on downside and the maximum diameter peripheral part plane of inclination from this arc surface to the top form.

3. inner ratchet wheel fastening device as claimed in claim 1 or 2 is combined with the back-up ring of the lip part that is fixed the band edge cylindrical body in the bottom of above-mentioned oil hydraulic cylinder periphery, prevents the come-up of band edge cylindrical body.

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