CN103453090B - Ratchet-type tensioner - Google Patents

Abstract

The invention provides a kind of ratchet-type tensioner, remove the engagement of the ratchet mechanism be made up of plunger and ratchet when maintenance service easily, make ratchet mechanism reliably when engine running and stably work, and misoperation does not occur, thus reduction dither tone, and prevent the hot sticky of plunger.In ratchet-type tensioner (100), the hook tooth (151) utilizing tool pin (T) to remove ratchet (150) is made up of tool pin engagement portion (154) and pin insertion hole (114) the ratchet cancel system of the engagement of the rack tooth (122) of plunger (120), described tool pin engagement portion (154) is arranged at the plunger side front end area of ratchet (150) and the pin front end (T1) for tool pin (T) abuts engaging, and described pin insertion hole (114) is arranged at described shell main body (110) and towards tool pin engagement portion (154) insertion tool pin (T).

Description

Ratchet-type tensioner

Technical field

The present invention relates to the ratchet-type tensioner timing chain of the camshaft driving motor etc. being given to tension force.

Background technique

In the prior art, there will be a known the stretcher that a kind of timing chain driven the camshaft etc. of motor uses, the outstanding masterpiece that this stretcher makes spring and external hydraulic produce for be inserted into slidably housing and and form the plunger of grease chamber between housing, thus give tension force to timing chain.

As shown in figure 16, as this existing stretcher, such as, can adopt the stretcher 500 with following structure.Described stretcher 500 comprises: piston 526, and it is inserted into housing 512 slidably along the direction orthogonal with the glide direction of plunger 514, thus and between housing 512, form secondary grease chamber 520; Oil circuit 544, acts on secondary grease chamber 520 for making external hydraulic; Atmospheric air chamber 528, the opposition side in secondary grease chamber 520 is formed, built with the second spring 534 being carried out towards secondary grease chamber 520 exerting a force by piston 526 by housing 512 and piston 526 strokes of sections; Lid 530, is embedded in atmospheric air chamber 528.The air connectivity hole 532 be communicated with air is set at this atmospheric air chamber 528, when the active force that outside hydraulic pressure makes piston 526 resist the second spring 534 in secondary grease chamber 520 carries out mobile, closes described air connectivity hole 532 by piston 526; Carve in the part of being surrounded by housing 512 of plunger 514 and establish tooth bar 538; And multiple engaging tooth 536 that can engage with tooth bar 538 is set in the front end of the piston rod 524 being fixed on piston 526; Engaging tooth 536 retreats the flank of tooth with the anti-plunger of tooth bar 538 and is formed as vertical with the advance and retreat direction of plunger 514 (referenced patent document 1).

Prior art document

Patent documentation

Patent documentation 1: Japanese utility model patents mandate No. 2559664 publication (mandate claims of model utility, Fig. 1).

Summary of the invention

In above-mentioned existing stretcher 500, be incorporated in the inside of atmospheric air chamber 528 due to the piston rod 524 being provided with multiple engaging tooth 536 and sealed by lid 530, so when making timing chain relax to carry out the maintenance service such as positioning operation, part replacement operation of ratchet-type tensioner, timing chain, there is the difficult problem in maintenance service operation as described below: even if the plunger 514 pushing back arbitrarily ratchet-type tensioner makes it retreat, also cannot remove the engagement between the engaging tooth 536 of piston rod 524 and the tooth bar 538 of plunger 514.

And, in above-mentioned existing stretcher 500, because plunger 514 and piston 526 are cylindrical structure, so just, there are the following problems: corresponding to the vibration of the plunger 514 during engine-driving, engagement between the tooth bar 538 and the engaging tooth 536 of piston 526 of plunger 514 presents excessive spline state, and make the engaging tooth 536 of piston 526 be easy to hypodontia, shortly become engagement throughout the facewidth whole region generation distortion not mate, cause the ratchet mechanism be made up of engaging tooth 536 and tooth bar 538 to produce misoperation; In addition, when manufacture and the maintenance service of stretcher, plunger 514 and piston 526 cause producing assembling by mistake each other around respective axis rotation.

In addition, in above-mentioned stretcher 500 in the past, the anti-plunger forming engaging tooth 536 and tooth bar 538 due to the flank of tooth vertical with the advance and retreat direction with plunger 514 retreats the flank of tooth, so there are the following problems: the temperature variation of motor etc. cause chain tension excessive, the movement of the direction of retreat of plunger 514 is caused also to be restricted thus, cause plunger 514 hot sticky, or chain is advanced with excessive tension force always and the burden of chain and noise is increased.

Therefore, the maximum assumed value of the movement of the direction of retreat of the corresponding plunger 514 occurred because chain tension is excessive, the ratchet mechanism be made up of engaging tooth 536 and tooth bar 538 arranges the backlash (backlash of regulation; Gear sideshake) amount, but the impact sound being called dither tone that such backlash amount is larger when more cannot reduce engine start.

In addition, in order to solve this when engine start this problem of incidental impact sound, additional orifice (orifice) mechanism and oil-bearing structure can be taked as countermeasure, or plunger force spring 518 is changed to the modes such as the spring of reply high loading, but there are the following problems, not only therefore number of components and manufacture cost increase, and stretcher self also becomes maximization.

At this, the present invention, for solving existing problem, namely, the object of the present invention is to provide a kind of ratchet-type tensioner, and this ratchet-type tensioner, when maintenance service, can remove the engagement of the ratchet mechanism be made up of plunger and ratchet easily; Further, produce misoperation when engine running do not make ratchet mechanism reliable and stable operation, thus reduce dither tone for the backlash of the plunger counter-force generation of bearing from timing chain when suppressing to start after long-term placement motor; And allow the movement of the direction of retreat of the plunger occurred because the chain tension after engine start is excessive, to prevent the hot sticky of plunger.

First, the invention involved by technological scheme 1 is a kind of ratchet-type tensioner, comprising: the shell main body being formed with the oily supply passage of external pressure oil; From the plunger that the plunger reception hole of this shell main body is slidably given prominence to towards chain of advancing; Be accommodated in be formed at described shell main body the high-pressure oil chamber between plunger reception hole and the hollow portion of plunger in, and carry out the plunger loading spring that loads along the projected direction of plunger; Be intercalated in the ratchet reception hole of described shell main body, and carry out along the direction orthogonal with the advance and retreat direction of plunger the cylindric ratchet that slides; To the ratchet loading spring that the hook tooth of the plunger side front end area being arranged at this ratchet loads towards the rack tooth of plunger side; The rear end embedding described ratchet reception hole is neighbouring to make spring locking plug (plug) of ratchet loading spring dropping place; Wherein, tool pin is utilized to be made up of to the ratchet cancel system of the hook tooth removing described ratchet for the engagement of the rack tooth of described plunger tool pin engagement portion and pin insertion hole, the plunger side front end area that described tool pin engagement portion is arranged at described ratchet abuts engaging to make the pin front end of tool pin, described pin insertion hole is arranged at described shell main body and towards tool pin engagement portion insertion tool pin, solves described problem thus.

Invention involved by technological scheme 2, except the structure of the involved invention of technological scheme 1, the tool pin engagement portion of described ratchet is formed at the step-like bearing surface between hook tooth and ratchet outer circumferential face by the plunger side front end area at described ratchet and forms, and the pin insertion hole of described shell main body is arranged to push back ratchet with the step-like bearing surface of described tool pin driving ratchet with the back-loading direction to ratchet, solves described problem thus.

Invention involved by technological scheme 3, except the structure of the involved invention of technological scheme 1, the tool pin engagement portion of described ratchet is made up of the taper bearing surface plunger side front end area of described ratchet being cut away a part towards back-end region side, and the pin insertion hole of described shell main body is arranged to push back ratchet with the taper bearing surface of described tool pin pressing ratchet with the back-loading direction to ratchet, solves described problem thus.

Invention involved by technological scheme 4, except the structure of inventing involved by any one of technological scheme 1 to 3, the loading force of described ratchet loading spring is set the component being greater than ratchet glide direction plunger being occurred when engine start from the counter-force that chain side of advancing retreats, and be set the chain tension be less than after the engine started excessive time plunger is occurred from the counter-force that chain side of advancing retreats the component of ratchet glide direction, solve described problem thus.

Invention involved by technological scheme 5, except the structure of inventing involved by any one of technological scheme 1 to 4, the rack tooth of described plunger is formed by stop surface and slip surface, concave-convex surface; Described stop surface tilts to plunger advancement side relative to the glide direction of described ratchet, and described slip surface tilts to plunger relative to the glide direction of described ratchet and retreats side; And the hook tooth of described ratchet is formed by stop opposed faces and slip opposed faces, concave-convex surface; Described stop opposed faces tilts to plunger advancement side relative to the glide direction of described ratchet, and described slip opposed faces tilts to plunger relative to the glide direction of described ratchet and retreats side, solves described problem thus.

Invention involved by technological scheme 6, except the structure of the involved invention of technological scheme 5, the tilt angle of described stop surface is formed be less than the tilt angle of described slip surface, solves described problem thus.

Invention involved by technological scheme 7, except the structure of inventing involved by any one of technological scheme 1 to 6, make the hook tooth of described ratchet can not carry out to distortion the engagement matching mechanism for seedlings engaged in whole facewidth universe for the rack tooth of described plunger side, be configured to make the outer circumferential face of described ratchet be in spline state relative to the inner peripheral surface of described ratchet reception hole, solve described problem thus.

Invention involved by technological scheme 8, except the structure of the involved invention of technological scheme 7, described engagement matching mechanism for seedlings is made up of ratchet side raised line and case side groove, described ratchet side raised line is arranged at the outer circumferential face of described ratchet along glide direction, described case side groove with the state of this ratchet side raised line male-female engagement under to be arranged at the inner peripheral surface of described ratchet reception hole along glide direction, solve described problem thus.

Invention involved by technological scheme 9, except technological scheme 7 or the involved structure of inventing of technological scheme 8, described ratchet possesses the ratchet total length size being greater than ratchet outside dimension, solves described problem thus.

Invention involved by technological scheme 10, except the structure of inventing involved by any one of technological scheme 7 to 9, described ratchet loading spring is inserted in the spring reception hole of described ratchet along glide direction, solves described problem thus.

At this, ratchet-type tensioner of the present invention comprises: the oily supply passage shell main body being formed with external pressure oil; From the plunger that the plunger reception hole of this shell main body is slidably given prominence to towards chain of advancing; Be accommodated in be formed at described shell main body the high-pressure oil chamber between plunger reception hole and the hollow portion of plunger in, and carry out the plunger loading spring that loads along the projected direction of plunger; Be intercalated in the ratchet reception hole of described shell main body, and carry out along the direction orthogonal with the advance and retreat direction of plunger the cylindric ratchet that slides; To the ratchet loading spring that the hook tooth of the plunger side front end area being arranged at this ratchet loads towards the rack tooth of plunger side; The rear end embedding described ratchet reception hole is neighbouring to make the spring locking of ratchet loading spring dropping place fill in.By said structure, tension force can not only be given from the plunger of ratchet-type tensioner to in-engine timing chain, but also effect specific to following the present invention can be obtained.

Namely the ratchet-type tensioner of the present invention, involved by technological scheme 1, the hook tooth utilizing tool pin to remove ratchet is made up of tool pin engagement portion and pin insertion hole relative to the ratchet cancel system of the engagement of the rack tooth of plunger, described tool pin engagement portion is arranged at the plunger side front end area of ratchet and the pin front end for tool pin abuts engaging, and described pin inserts and is arranged at described shell main body and inserts towards tool pin engagement portion for tool pin.By such structure, the pin front end of tool pin is made to abut the tool pin engagement portion being sticked in ratchet from pin insertion hole, easily to remove the engagement of hook tooth relative to the rack tooth of plunger of ratchet, thus the plunger of ratchet-type tensioner can be pushed back to make it retreat, so significantly can alleviate the homework burden of the maintenance service such as location and part replacement of ratchet-type tensioner under the state that timing chain is relaxed, timing chain.

Ratchet-type tensioner of the present invention involved by technological scheme 2, except the effect that the involved invention of technological scheme 1 obtains, also obtain following effect: the step-like bearing surface that the tool pin engagement portion of ratchet is formed between hook tooth and ratchet outer circumferential face by the plunger side front end area at ratchet is formed, and the pin insertion hole of shell main body is arranged to push back ratchet with the step-like bearing surface of tool pin driving ratchet with the back-loading direction to ratchet.By such structure, make the driving masterpiece of the tool pin of inserting on the pin insertion hole of shell main body for step-like bearing surface, thus work in the mode pushing back ratchet to the back-loading direction of ratchet, so easily can remove the engagement of hook tooth relative to the rack tooth of plunger of ratchet.

Ratchet-type tensioner of the present invention involved by technological scheme 3, except the effect that the involved invention of technological scheme 1 obtains, also obtain following effect: the tool pin engagement portion of ratchet is made up of the taper bearing surface plunger side front end area of ratchet being cut away a part towards back-end region side, and the pin insertion hole of shell main body is arranged to push the taper bearing surface of ratchet to be pushed back in the back-loading direction of ratchet to ratchet by tool pin.By such structure, the pushing force of the tool pin interted in the pin insertion hole of shell main body has produced the component of following effect, namely ratchet is pushed back, so the engagement of hook tooth relative to the rack tooth of plunger of ratchet easily can be removed by taper bearing surface to the back-loading direction of ratchet.

The present invention involved by technological scheme 4, except inventing the effect of acquisition involved by any one of technological scheme 1 to 3, also obtain following effect: the active force of ratchet loading spring is set than large by the component of the ratchet glide direction making plunger produce from the counter-force that chain side of advancing retreats when engine start, if produce the counter-force making plunger retreat thus when engine start, then the active force of ratchet loading spring acts on the hook tooth of ratchet to be meshed with the rack tooth of plunger, so the movement that can not only limit the direction of retreat of the plunger having produced backlash retreats displacement to stop, and reduce the dither tone of timing chain, and the active force of plunger loading spring is only, and to make plunger give prominence to the active force of force just enough, so do not need the plunger loading spring of special reply high loading and orifice mechanism and oil-bearing structure, number of components and manufacture cost can be reduced and make stretcher self miniaturization.

In addition, it is little by the component of the ratchet glide direction making plunger produce from the counter-force that chain side of advancing retreats when the active force of ratchet loading spring is set more excessive than chain tension after the engine started, if produce the counter-force making plunger retreat when chain tension thus is after the engine started excessive, then the active force of ratchet loading spring acts on the hook tooth of ratchet, the hook tooth of ratchet and the rack tooth of plunger is made to depart from engagement (engagement is separated), and plunger is retreated until the active force of ratchet loading spring is relatively greater than the component of ratchet glide direction, even if so because of the temperature variation etc. of motor make plunger exceedingly before so that there is the mistake load that check causes, also can not limit the movement of the direction of retreat of plunger and allow to retreat displacement to prevent the hot sticky of plunger.Moreover, can also by the active force of adjustment ratchet loading spring, the moment that the engagement excessive caused to the chain tension after engine start is separated adjusts, so can reliably prevent the hot sticky of plunger.

The present invention involved by technological scheme 5, except inventing the effect of acquisition involved by any one of technological scheme 1 to 4, also obtain following effect: the rack tooth of plunger is rolled oblique stop surface by the glide direction relative to ratchet to plunger advancement and retreats to plunger and rolls oblique slip surface concave-convex surface and is formed, and the hook tooth of ratchet is rolled oblique stop opposed faces and retreats the oblique slip opposed faces concave-convex surface of inclination to plunger and formed to plunger advancement by the glide direction relative to ratchet.By such structure, if produce the counter-force making plunger retreat when chain tension is after the engine started excessive, then this counter-force acts on the stop opposed faces of ratchet as component via the stop surface of plunger side, the component having acted on the stop opposed faces of ratchet acts on as the less component of ratchet glide direction, depart from the rack tooth of the hook tooth with plunger that make ratchet and engage, the rack tooth of plunger slides via the stop opposed faces of ratchet and returns the amount of a tooth in slip opposed faces, so the wearing and tearing of incidental hypodontia etc. on the hook tooth of ratchet and the rack tooth of plunger when the chain tension after engine start can be prevented excessive, and the movement of the direction of retreat of plunger can not be limited and successfully allow to retreat displacement, and the serviceability excess impact for ratchet loading spring can avoided and play very well.

The present invention involved by technological scheme 6, except the effect that the involved invention of technological scheme 5 obtains, also obtain following effect: the tilt angle of stop surface is formed be less than the tilt angle of slip surface, even if produce the counter-force making plunger retreat thus when engine start, also the rack tooth of plunger can be stoped to be separated with the engagement of the hook tooth of ratchet, so there is the movement of the direction of retreat of the plunger of backlash when can be limited in engine start, to stop retrogressing displacement.

The present invention involved by technological scheme 7, except inventing the effect of acquisition involved by any one of technological scheme 1 to 6, also obtain following effect: the engagement matching mechanism for seedlings that the hook tooth of ratchet is not engaged in whole facewidth region relative to the rack tooth of plunger side with having distortion is formed relative to the state of the inner peripheral surface spline of ratchet reception hole to make the outer circumferential face of ratchet.By such structure, for the vibration of plunger during engine-driving, with engage independently between the rack tooth of plunger side and the hook tooth of ratchet, make the outer circumferential face of ratchet relative to the inner peripheral surface spline of ratchet reception hole, so can make the ratchet mechanism that is made up of plunger and ratchet reliably and stably work, and the hook tooth of ratchet can be made correctly to engage in whole facewidth region for the rack tooth of plunger side, so the distortion mistake between the rack tooth of plunger side and the hook tooth of ratchet can being avoided to assemble cause is to eliminate the misoperation of ratchet mechanism.

Ratchet-type tensioner of the present invention involved by technological scheme 8, except the effect that the involved invention of technological scheme 7 obtains, also obtain following effect: engagement matching mechanism for seedlings by be arranged at along glide direction ratchet outer circumferential face ratchet side raised line and with the state of this ratchet side raised line male-female engagement under be arranged at the inner peripheral surface of ratchet reception hole along glide direction case side groove form.By such structure, slide under can being fully in spline state at the inner peripheral surface making the outer circumferential face of ratchet relative to ratchet reception hole, so the ratchet mechanism be made up of plunger and ratchet can be made successfully to work, and because the ratchet reception hole in case side imposes groove, so compared with the engagement matching mechanism for seedlings imposing raised line with the ratchet reception hole in case side, the making burden of engagement matching mechanism for seedlings significantly can be alleviated.

Ratchet-type tensioner of the present invention involved by technological scheme 9, except the effect that technological scheme 7 or the involved invention of technological scheme 8 obtain, also obtain following effect: ratchet possesses the ratchet total length size being greater than ratchet outside dimension, even if when assume responsibility for superfluous load thus on ratchet, also the inclination relative to the incidental ratchet of the glide direction in ratchet reception hole can be suppressed, to prevent the partial wear of ratchet, so the ratchet mechanism be made up of plunger and ratchet can be made more successfully to carry out work.

In addition, ratchet-type tensioner of the present invention involved by technological scheme 10, except the effect that invention involved any one of technological scheme 7 to 9 obtains, also obtain following effect: ratchet loading spring is inserted in the spring reception hole of ratchet along glide direction, just become ratchet loading spring thus and almost all insert state in the spring reception hole of ratchet, so compared with this situation of outer circumferential face being embedded in ratchet outside ratchet loading spring, ratchet can be made to simplify and miniaturization relative to the installation form of ratchet reception hole.

Accompanying drawing explanation

Fig. 1 is the using state figure of the ratchet-type tensioner 100 of first embodiment of the invention.

Fig. 2 is the main portions enlarged view of the ratchet-type tensioner 100 shown in Fig. 1.

Fig. 3 is the enlarged view of rack tooth and hook tooth.

Fig. 4 is the sectional view along the A-A line shown in Fig. 2.

Fig. 5 is the exploded view of ratchet, ratchet force-application spring and spring locking plug.

Give prominence to the engagement schematic diagram of action with plunger when Fig. 6 is engine start.

With the engagement schematic diagram of plunger backward movement when Fig. 7 is engine start.

Fig. 8 is the engagement schematic diagram that the excessive plunger caused of chain tension retreats when starting.

Fig. 9 is the engagement separated state schematic diagram in the excessive plunger backward movement process caused of chain tension.

Figure 10 is the engagement schematic diagram at the end of the excessive plunger caused of chain tension retreats.

Figure 11 is the explanatory drawing of the ratchet releasing action in first embodiment of the invention.

Figure 12 is the main portions enlarged view of the ratchet-type tensioner 100 of second embodiment of the invention.

Figure 13 is the sectional view along the B-B line shown in Figure 12.

Figure 14 is the exploded view of ratchet, ratchet force-application spring and spring locking plug.

Figure 15 is the explanatory drawing of the ratchet releasing action in second embodiment of the invention.

Figure 16 is the sectional view of existing ratchet-type tensioner 500.

The explanation of reference character

100,200: ratchet-type tensioner

110,210: shell main body

111,211: oily supply passage

112,212: plunger reception hole

113,213: ratchet reception hole

113a: case side groove

114,214: pin insertion hole

120,220: plunger

121,221: hollow portion

122,222: rack tooth

122a: stop surface

122b: slip surface

130,230: plunger loading spring

140,240: check valve unit

141,241: ball seat

141a, 241a: oil circuit

141b, 241b: valve seat

142,242: check ball

143,243: ball loading spring

144,244: bell retainer

150,250: ratchet

151,251: hook tooth

151a: stop opposed faces

151b: slip opposed faces

152: ratchet side raised line

153,253: spring reception hole

154,254: tool pin engagement portion

154a: step-like bearing surface

254a: taper bearing surface

160,260: ratchet loading spring

170,270: spring locking is filled in

171,271: projecting tabs

S1: driving side sprocket wheel

S2: slave end sprocket wheel

C: timing chain

L: movable rod

G: fixed guide

P: piston portion high-pressure oil chamber

R: high-pressure oil chamber

D: ratchet outside dimension

W: ratchet total length size

Fs: the active force of ratchet loading spring

F1: make the counter-force that plunger retreats during engine start

F2: counter-force during engine start rear chain overtension, plunger being retreated

F1: the component of the ratchet glide direction produced by counter-force F1

F2: the component of the ratchet glide direction produced by counter-force F2

Fh: the component being acted on plunger stop surface by counter-force F2

θ: the tilt angle being formed in the stop surface on plunger

α: the tilt angle being formed in the slip surface on plunger

T: tool pin

T1: pin front end

500: existing ratchet-type tensioner

512: housing

514: plunger

516: grease chamber

518: spring

520: secondary grease chamber

524: piston rod

526: piston

528: atmospheric air chamber

530: lid

532: air connectivity hole

534: the second springs

536: engaging tooth

538: tooth bar

544: oil circuit

548: oil circuit

550: oil groove

Embodiment

Ratchet-type tensioner of the present invention comprises: shell main body, is formed with the oily supply passage of external pressure oil; Plunger, slidably gives prominence to from the plunger reception hole of this shell main body towards chain of advancing; Plunger loading spring, be accommodated in be formed at described shell main body the high-pressure oil chamber between plunger reception hole and the hollow portion of plunger in, and to exert a force along the projected direction of plunger; Cylindric ratchet, is intercalated in the ratchet reception hole of described shell main body, and slides along the direction orthogonal with the advance and retreat direction of plunger; Ratchet loading spring, loads the hook tooth of the plunger side front end area by being arranged at this ratchet rack tooth towards plunger side; Spring locking is filled in, and the rear end embedding described ratchet reception hole is neighbouring also for ratchet loading spring dropping place.Ratchet cancel system utilizes tool pin to remove the engagement of hook tooth relative to the rack tooth of plunger of ratchet, described ratchet cancel system is made up of tool pin engagement portion and pin insertion hole, described tool pin engagement portion is arranged at the plunger side front end area of ratchet and the pin front end for tool pin abuts engaging, described pin insertion hole is arranged in described shell main body and also inserts towards tool pin engagement portion for tool pin, the engagement of the ratchet mechanism be made up of plunger and ratchet can be removed easily when maintenance service, the work not making ratchet mechanism reliable and stable while misoperation occurs when engine running, thus reduce dither tone for the backlash of the plunger counter-force generation of bearing from timing chain when suppressing to start after long-term placement motor, and allow the movement of the direction of retreat of the plunger produced because of engine start rear chain overtension, thus prevent the hot sticky of plunger, as long as ratchet-type tensioner of the present invention can reach above-mentioned effect, its embodiment can be arbitrary.

Such as, about the grown form of the shell main body in ratchet-type tensioner of the present invention, can be any one following form, that is: the pressure oil supplied from oil pump directly be imported the form of the oily supply passage be formed in shell main body; Or be arranged with the form in oil storage portion, described oil storage portion, for before the pressure oil supplied from oil pump being imported the oily supply passage be formed in shell main body, is temporary in the back portion of shell main body.

In addition, when ratchet-type tensioner of the present invention, for the bottom stoping pressure oil to be installed in plunger reception hole to the check valve unit of oily supply passage from adverse current in high-pressure oil chamber, or described check valve unit also can not be arranged on the bottom of plunger reception hole.

Further, when comprising the ratchet-type tensioner of above-mentioned check valve unit, as long as its concrete element form is arranged on the bottom of plunger reception hole, in order to stop the pressure oil adverse current extremely oily supply passage in high-pressure oil chamber, can be then arbitrary, such as, can be the form comprising ball seat, check ball, ball loading spring and bell retainer.Described ball seat is communicated with oily supply passage and supplies pressure oil to high-pressure oil chamber side; Described check ball is opposite with the valve seat of this ball seat; This check ball exerts a force to ball seat pushing by described ball loading spring; Described bell retainer is for limiting the amount of movement of check ball.

And, about the active force of ratchet loading spring used in ratchet-type tensioner of the present invention, if set larger than the component of ratchet glide direction making plunger produce from the counter-force that chain side of advancing retreats when engine start and more excessive than chain tension after the engine started time plunger is retreated the component of ratchet glide direction that produces of counter-force little, the active force of any absolute value can be adopted, be more preferably set to the active force of the friction factor also contemplated between the rack tooth of plunger and the hook tooth of ratchet.

Further, about the hook tooth of the ratchet used in ratchet-type tensioner of the present invention relative to the engagement matching mechanism for seedlings of the rack tooth of plunger side, as long as formed with the state that the outer circumferential face of ratchet is in spline relative to the inner peripheral surface of ratchet reception hole, it can be arbitrary concrete form, such as, be made up of ratchet side raised line and case side groove, described ratchet side raised line is by the rectangular spline of outer circumferential face being arranged at the ratchet possessing circular cross-section along glide direction, the splines such as involute splines are formed, described case side groove is by roughly with the inner peripheral surface of the ratchet reception hole in footpath carving the rectangular flower keyway of establishing groove along glide direction with ratchet with under the concavo-convex state engaged of this ratchet side raised line, the splines such as involute splines groove are formed, be made up of ratchet side groove and case side raised line, described ratchet side groove is made up of the spline such as rectangular flower keyway, involute splines groove of the outer circumferential face being arranged at the ratchet possessing circular cross-section along glide direction, and described case side raised line is by roughly forming with the spline such as rectangular spline, involute splines of the inner peripheral surface of the ratchet reception hole in footpath with ratchet with being arranged at along glide direction under the concavo-convex state engaged of this ratchet side groove, or, utilize the ratchet that possesses oval cross section and possess and carry out spline with the ratchet reception hole of this ratchet roughly shell main body of the oval cross section of similar shape.

In addition, about the concrete form of the present embodiment ratchet used, as long as possess multiple hook tooth in the plunger side front end area of ratchet to be provided with tool pin engagement portion simultaneously, described hook tooth can not engage to distortion in whole facewidth universe with the rack tooth being located at plunger side quarter; Described tool pin engagement portion abuts engaging for the pin front end of tool pin.

Such as, about the concrete form of hook tooth, if possess the space of teeth of equal pitch and the plural hook tooth of same tooth depth, just can disperse mesh loadings equably to engage towards the rack tooth of plunger side, therefore more preferred.

In addition, about the concrete form of the tool pin engagement portion set by the plunger side front end area of ratchet, as long as the engagement of the ratchet mechanism be made up of plunger and ratchet can be removed easily when maintenance service, it can be then any one following form, that is, the step-like bearing surface between hook tooth and ratchet outer circumferential face is formed in the plunger side front end area of ratchet; Or, the plunger side front end area of ratchet is cut away the taper bearing surface of a part towards back-end region side.

[embodiment]

Below, based on Fig. 1 to Figure 15, the ratchet-type tensioner 100 as one embodiment of the invention is described.

Here, Fig. 1 is the use aspect graph of the ratchet-type tensioner 100 of first embodiment of the invention, and Fig. 2 is the sectional view being exaggerated the ratchet-type tensioner 100 shown in Fig. 1, and Fig. 3 is the enlarged view of rack tooth and hook tooth.Fig. 4 is the sectional view along the A-A line shown in Fig. 2, Fig. 5 is ratchet, the exploded view of ratchet loading spring and spring locking plug, give prominence to the rack tooth of action with plunger when Fig. 6 is engine start, hook tooth and engagement schematic diagram, with the rack tooth of plunger backward movement when Fig. 7 is engine start, hook tooth and engagement schematic diagram, Fig. 8 is the rack tooth that the excessive plunger caused of chain tension retreats when starting, hook tooth and engagement schematic diagram, Fig. 9 is the rack tooth in the excessive plunger backward movement caused of chain tension, hook tooth and nibble from view, Figure 10 is the rack tooth at the end of the excessive plunger caused of chain tension retreats, hook tooth and engagement schematic diagram, Figure 11 is the explanatory drawing of the ratchet releasing action in first embodiment of the invention, Figure 12 is the main portions enlarged view of the ratchet-type tensioner 100 of second embodiment of the invention, Figure 13 is the sectional view along the B-B line shown in Figure 12, Figure 14 is ratchet, the exploded view of ratchet loading spring and spring locking plug, Figure 15 is the explanatory drawing of the ratchet releasing action in second embodiment of the invention.

First, as shown in Figure 1, the slack-side of being carried out the timing chain C set up between the driving side sprocket wheel S1 that rotates and the slave end sprocket wheel S2 being fixed on camshaft by the bent axle of motor is located at as the ratchet-type tensioner 100 of first embodiment of the invention, and be installed on engine main body, plunger 120 is given prominence to from the front surface of this shell main body 110 with freely retreating, by making plunger 120 push the back side near the free shake end being joltily bearing in the movable rod L of engine main body side, give tension force via movable rod L to the slack-side of timing chain C.

In addition, at the advancing side of timing chain C, the fixed guide G for guiding timing chain C to advance is installed in engine main body side.

And when driving side sprocket wheel S1 rotates in the direction of the arrow, timing chain C advances in the direction of the arrow, then, because of advancing of this timing chain C, slave end sprocket wheel S2 is rotated in the direction of the arrow, the rotation of driving side sprocket wheel S1 is delivered to slave end sprocket wheel S2 thus.

Therefore, as shown in Figure 2, the ratchet-type tensioner 100 of the present embodiment comprises: shell main body 110, and it is formed with the oily supply passage 111 importing the external pressure oil supplied from engine cylinder side; Columned plunger 120, it is slidably given prominence to from the plunger reception hole 112 be formed in this shell main body 110 towards chain of advancing (not shown); Plunger loads with spring 130, and it is housed in the high-pressure oil chamber R that formed between the plunger reception hole 112 of shell main body 110 and the hollow portion 121 of plunger 120, and exerts a force along the projected direction of plunger 120; Check valve unit 140, it is loaded into the bottom of plunger reception hole 112, to stop pressure oil from adverse current in high-pressure oil chamber R to oily supply passage 111; Columned ratchet 150, its intercalation enters the ratchet reception hole 113 of the cylindrical shape that described shell main body 110 is formed, and slides along the direction orthogonal with the advance and retreat direction of plunger 120; Ratchet loads with spring 160, and it exerts a force towards the mode of carving rack tooth 122 engagement being located at plunger side to make the hook tooth 151 of the plunger side front end area being arranged at ratchet 150; And spring locking is with plug 170, make ratchet loading spring 160 anticreep ground dropping place near its rear end embedding described ratchet reception hole 113.

(the concrete modular construction about check valve unit 140)

About the concrete modular construction of above-mentioned check valve unit 140, as long as be loaded into plunger reception hole 112 bottom and for stoping pressure oil from adverse current in high-pressure oil chamber R to the structure of oily supply passage 111, known arbitrary structures can be adopted, but in the present embodiment, adopt by ball seat 141, check ball 142, the check valve unit 140 that ball loading spring 143 and bell retainer 144 are formed, described ball seat 141 has the oily path 141a be connected with the oily supply passage 111 of above-mentioned shell main body 110, described check ball 142 dropping place is on the valve seat 141b of this ball seat 141, this check ball 142 is pushed force to being squeezed in ball seat 141 by described ball loading spring 143, described bell retainer 144 is for supporting this ball loading spring 143 and the amount of movement of restriction check ball 142.

(the concrete structure about engagement matching mechanism for seedlings)

In the ratchet-type tensioner 100 of the present embodiment, be provided with engagement matching mechanism for seedlings, this engagement matching mechanism for seedlings makes the hook tooth 151 of ratchet 150 can not engage with the rack tooth 122 of plunger side to distortion in whole facewidth region.

Namely, as shown in Fig. 2 and Fig. 4, above-mentioned engagement matching mechanism for seedlings is formed with the state making the outer circumferential face of ratchet 150 and be in spline relative to the inner peripheral surface of the ratchet reception hole 113 of the cylindrical shape be arranged on the direction orthogonal with the glide direction of plunger 120.

Thus, for the vibration of the plunger 120 during engine-driving, with engage independently between the rack tooth 122 of plunger side and the hook tooth 151 of ratchet 150, make the outer circumferential face of ratchet 150 relative to the inner peripheral surface spline of ratchet reception hole 113, and the hook tooth 151 of ratchet 150 is correctly engaged in whole facewidth region relative to the rack tooth 122 of plunger side.

Be described particularly further, above-mentioned engagement matching mechanism for seedlings is made up of ratchet side raised line 152 and case side groove 113a, described ratchet side raised line 152 is made up of the involute splines be arranged at along glide direction on ratchet 150 outer circumferential face, described case side groove 113a by with the state of this ratchet side raised line 152 male-female engagement under along glide direction, the involute splines groove be arranged on ratchet reception hole 113 inner peripheral surface is formed.

Thus, can slide under the state making the outer circumferential face of ratchet 150 relative to the inner peripheral surface fully spline of ratchet reception hole 113, and significantly alleviate the making burden of engagement matching mechanism for seedlings.

And, as shown in Figure 5, above-mentioned ratchet 150 possesses the ratchet total length size W being greater than ratchet outside dimension D, thus, even if when assume responsibility for superfluous load on ratchet 150, also can suppress the inclination relative to the incidental ratchet 150 of the glide direction in ratchet reception hole 113, and prevent the partial wear of ratchet 150, thus make the ratchet mechanism be made up of plunger 120 and ratchet 150 more successfully carry out work.

In addition, in ratchet 150 in the present embodiment, in order to disperse mesh loadings equably towards carving the rack tooth 122 being located at plunger side and engage, as Fig. 3 and arrange 3 hook tooths 151 possessed with the space of teeth of rack tooth 122 equal pitch and same tooth depth as shown in Figure 5 in plunger side front end area.

In addition, as shown in Figure 5, above-mentioned ratchet loading spring 160 inserts in ratchet 150 along glide direction with concentric circles, thus, become ratchet loading spring 160 almost all insert ratchet 150 spring reception hole 153 in state, compared with this situation of outer circumferential face being embedded in ratchet 150 outside ratchet loading spring 160, ratchet 150 is simplified and miniaturization relative to the installation form of ratchet reception hole 113.

And, about the active force of ratchet loading with spring 160, be configured to larger than the component of ratchet 150 glide direction making when engine start plunger 120 be produced by the counter-force retreated from chain side of advancing and more excessive than chain tension after the engine started time the component of ratchet 150 glide direction that produced by the counter-force making plunger 120 retreat little.

Thus, suppress the retrogressing displacement of plunger 120 when engine start and reduce the dither tone of timing chain, and allow the retrogressing displacement of the plunger 120 that the chain tension after engine start is excessive caused and prevent the hot sticky of plunger 120, do not need the plunger loading spring 160 of special corresponding high loading and orifice mechanism and oil-bearing structure, number of components and manufacture cost can be reduced and make stretcher self miniaturization.

Further, as shown in Figure 2, above-mentioned spring locking plug 170 be around be provided with embed ratchet reception hole 113 rear end near to play the so-called anti-avulsion pad for flexible multiple projecting tabs 171 of anti-avulsion, thus, as Fig. 2 and the rear end dropping place making ratchet loading spring 160 as shown in Figure 5.

Further, the correlation of the rack tooth 122 of the plunger 120 in the ratchet-type tensioner 100 of the present embodiment, the hook tooth 151 of ratchet 150 and ratchet loading spring 160 is illustrated in greater detail based on Fig. 3 and Fig. 6 to Fig. 8.

First, as shown in Figure 6, during normal operation when engine start and after engine start, plunger 120 outstanding when, be f1 > Fs all the time, plunger 120 pushes back ratchet 150 and advances.

At this, the directed force F s of the ratchet loading spring 160 that the present embodiment uses is set to be greater than component f1 and is less than component f2.Described component f1 is the power of ratchet 150 glide direction produced by the counter-force F1 making plunger 120 from chain side retrogressing of advancing when engine start as shown in Figure 7; Described component f2 be chain tension after the engine started as shown in Figure 8 excessive time by the power of ratchet 150 glide direction making plunger 120 produce from the counter-force F2 that chain side of advancing retreats.

Thus, the plunger when engine start is as shown in Figure 6 given prominence in action, is f1 > Fs all the time, and plunger 120 model-following control bar (not shown) advances.Then, if the counter-force F1 that the generation when engine start as shown in Figure 7 makes plunger 120 retreat from chain side of advancing, the directed force F s of then large than the component f1 of above-mentioned ratchet 150 glide direction ratchet loading spring 160 acts on the hook tooth 151 of ratchet 150, thus engage with the rack tooth 122 of plunger 120, and the movement that restriction has produced the direction of retreat of the plunger 120 of backlash retreats displacement to stop.

Further, if when the chain tension after the engine started shown in Fig. 8 is excessive, produce the counter-force F2 that plunger 120 is retreated from chain side of advancing, then the component f2 of above-mentioned ratchet 150 glide direction is greater than the directed force F s of ratchet loading spring 160, as shown in Figure 9, the hook tooth 151 of ratchet 150 and the rack tooth 122 of plunger 120 depart from engagement, plunger 120 is made correspondingly to retreat a tooth of rack tooth 122 or the amount of number tooth, until the directed force F s of ratchet loading spring 160 is relatively greater than the component f2 of ratchet glide direction, thus it is excessive and produce the movement of the direction of retreat of the plunger 120 of backlash not limit the chain tension after because of engine start, allow retrogressing displacement as shown in Figure 10.

Therefore, although the active force of plunger loading spring 130 is greater than the directed force F s of ratchet loading spring 160, as long as but make the active force of the outstanding force of plunger 120, when the engagement that the chain tension after can also adjusting engine start by the directed force F s adjusting ratchet loading spring 160 in this scope is excessive caused is separated.

Be described in further detail, in the ratchet-type tensioner 100 of the present embodiment, as shown in Figure 3, the rack tooth 122 of plunger 120 is formed by stop surface 122a and slip surface 122b concave-convex surface, described stop surface 122a rolls tiltedly relative to ratchet 150 glide direction to plunger advancement, and described slip surface 122b retreats inclination tiltedly relative to ratchet 150 glide direction to plunger.And, the hook tooth 151 of ratchet 150 is formed by stop opposed faces 151a and slip opposed faces 151b concave-convex surface, described stop opposed faces 151a rolls tiltedly relative to ratchet 150 glide direction to plunger advancement, and described slip opposed faces 151b retreats inclination tiltedly relative to ratchet 150 glide direction to plunger.

Thus, as shown in Figure 8, if produce the counter-force F2 making plunger 120 retreat from chain side of advancing when chain tension is after the engine started excessive, then this counter-force F2 acts on the stop opposed faces 151a of ratchet 150 as component fh via the stop surface 122a of plunger side, the component fh having acted on the stop opposed faces 151a of ratchet 150 as the less component f2 in ratchet 150 glide direction with the out-of-gear mode effect of rack tooth 122 of the hook tooth 151 with plunger 120 that make ratchet 150.As shown in Fig. 9 to Figure 10, the rack tooth 122 of plunger 120 slides on slip opposed faces 151b via the stop opposed faces 151a of ratchet 150, and returns the amount of a tooth or number tooth.

And the tiltangleθ of the stop surface 122a that above-mentioned plunger 120 is formed is set to be less than the inclined angle alpha of slip surface 122b.

Thus, even if produce the counter-force F1 making plunger 120 retreat from chain side of advancing when engine start, the rack tooth 122 of plunger 120 also can be stoped to be separated with the engagement of the hook tooth 151 of ratchet 150.

Therefore, as mentioned above, even if the temperature variation etc. because of motor makes the mistake load that plunger 120 is excessively front and then occur because check causes, when the chain tension after engine start is as shown in Figure 9 excessive by the component f2 of ratchet 150 glide direction of counter-force F2 generation making plunger 120 retreat from chain side of advancing and the magnitude relationship of the directed force F s of ratchet loading spring 160 be:

f2＝F2×cosθ×sinθ×μ

f2＞Fs。

In addition, μ mentioned here refers to the friction factor between the rack tooth 122 of plunger 120 and the hook tooth 151 of ratchet 150.

In addition, the movement direction of retreat of the plunger 120 of backlash having occurred when limiting above-mentioned engine start with when stoping and retreating displacement, as shown in Figure 7 when engine start by the component f1 of ratchet 150 glide direction of counter-force F1 generation making plunger 120 retreat from chain side of advancing and the magnitude relationship of the directed force F s of ratchet loading spring 160 be:

f1＝F1×cosθ×sinθ×μ

f1＜Fs。

In addition, μ mentioned here refers to the friction factor between the rack tooth 122 of plunger 120 and the hook tooth 151 of ratchet 150.

Next, based on the ratchet-type tensioner 100 maximum feature of Fig. 8 to Figure 10 with regard to the present embodiment, that is, the engagement separating action of the rack tooth 122 of the plunger 120 during engine start rear chain overtension and the hook tooth 151 of ratchet 150 illustrates as follows.

In addition, the imaginary line shown in plunger forward end of Fig. 8 to Figure 10 represents the front position of the plunger 120 of state when chain tension occurring after engine start being excessive, shown in Fig. 8.In addition, near the ratchet of Fig. 9 to Figure 10, the imaginary line shown in side represents the position of the ratchet 150 of state when chain tension occurring after engine start being excessive, shown in Fig. 8.

First, if when chain tension is after the engine started excessive, produce the counter-force F2 that plunger 120 is retreated from chain side of advancing, then as shown in Figure 8, this counter-force F2 acts on the stop opposed faces 151a of ratchet 150 as component fh via the stop surface 122a of plunger side, acted on the less component f2 effect of component fh as ratchet 150 glide direction of the stop opposed faces 151a of ratchet 150.

Then, if the component f2 effect of above-mentioned ratchet 150 glide direction, then as shown in Figure 9, the stop opposed faces 151a of stop surface 122a in ratchet side of plunger side slides, plunger 120 is while start to retreat, and the rack tooth 122 of plunger 120 departs from the hook tooth 151 of ratchet 150.

Next, while the rack tooth 122 of plunger 120 departs from the hook tooth 151 of ratchet 150, the slip surface 122b of plunger side slides on the slip opposed faces 151b of ratchet side, and plunger 120 is while continue to retreat.

Further, if the slip surface 122b of plunger side is while start to slide at the slip opposed faces 151b of ratchet side, plunger 120 is while continue to retreat, then as shown in Figure 10, the follow-up new stop surface 122a of plunger side is connected to the stop opposed faces 151a of ratchet side and allows to retreat displacement, make plunger 120 return a tooth of rack tooth 122 or the amount of number tooth, that removes the plunger 120 that the temperature variation etc. because of motor occurs thus excessively bloats caused mistake load.

(about the concrete of ratchet cancel system, form is set)

Next, the hook tooth 151 that namely the maximum feature of ratchet-type tensioner 100 illustrating in greater detail the present embodiment based on Fig. 5 and Figure 11 utilizes tool pin T to remove ratchet 150 arranges form relative to the concrete of ratchet cancel system of the engagement of the rack tooth 122 of plunger 120.

First, as shown in Fig. 5 and Figure 11, above-mentioned ratchet cancel system is made up of tool pin engagement portion 154 and pin insertion hole 114.Wherein, this tool pin engagement portion 154 is arranged at the plunger side front end area of above-mentioned ratchet 150 and supplies the pin front end T1 of tool pin T to abut engaging; This pin insertion hole 114 is arranged at above-mentioned shell main body 110 and inserts towards tool pin engagement portion 154 for tool pin T.

Namely, as shown in figure 11, ratchet 150 tool pin engagement portion 154 ratchet 150 plunger side front end area by be formed in hook tooth 151 and as a part for ratchet outer circumferential face ratchet side raised line 152 between step-like bearing surface 154a form.On the other hand, the pin insertion hole 114 of shell main body 110 is arranged to push back ratchet 150 with the step-like bearing surface 154a of tool pin T driving ratchet 150 with the back-loading direction to ratchet 150.

Thus, the driving masterpiece of the tool pin T that the pin insertion hole 114 of shell main body 110 is inserted for the step-like bearing surface 154a of ratchet 150, thus can push back ratchet 150 to the back-loading direction of ratchet 150.

In the ratchet-type tensioner 100 of the first embodiment of the invention of such acquisition, the hook tooth 151 utilizing tool pin T to remove ratchet 150 is made up of tool pin engagement portion 154 and pin insertion hole 114 relative to the ratchet cancel system of the engagement of the rack tooth 122 of plunger 120.Wherein, described tool pin engagement portion 154 is made up of the step-like bearing surface 154a being formed at ratchet 150, and described pin insertion hole 114 is in order to arrange with the step-like bearing surface 154a of tool pin T driving ratchet 150.By such structure, the driving power of the tool pin T interted in the pin insertion hole 114 of shell main body 110 can act on step-like bearing surface 154a, moves it, and the back-loading direction to ratchet 150 pushes back ratchet 150.Owing to plunger 120 being pushed back relative to the engagement of the rack tooth 122 of plunger 120 and make it retreat by the hook tooth 151 of easily removing ratchet 150, so the homework burden of the maintenance services such as ratchet-type tensioner under the state making timing chain relax, the location of timing chain and part replacement can be alleviated significantly.

And the engagement matching mechanism for seedlings of the rack tooth 122 of plunger side and the hook tooth 151 of ratchet 150 is made up of ratchet side raised line 152 and case side groove 113a, becomes the state of the inner peripheral surface spline making the outer circumferential face of ratchet 150 relative to ratchet reception hole 113.Described ratchet side raised line 152 is arranged at ratchet 150 outer circumferential face along glide direction; Described case side groove 113a with the state of ratchet side raised line 152 male-female engagement under be arranged at ratchet reception hole 113 inner peripheral surface along glide direction.Can make the ratchet mechanism that is made up of plunger 120 and ratchet 150 reliably by such structure and stably carry out work, and avoid the mistake between the rack tooth 122 of plunger side and the hook tooth 151 of ratchet 150 to assemble the distortion caused, thus eliminate the misoperation of ratchet mechanism.

Further, in the present first embodiment, the rack tooth 122 of plunger 120 is by rolling oblique stop surface 122a to plunger advancement and retreating the oblique slip surface 122b concave-convex surface of inclination to plunger and formed, and the hook tooth 151 of ratchet 150 is by rolling oblique stop opposed faces 151a to plunger advancement and retreating the oblique slip opposed faces 151b concave-convex surface of inclination to plunger and formed; And the tiltangleθ of stop opposed faces 151a is formed less than the inclined angle alpha of slip opposed faces 151b.By such structure, the wearing and tearing of incidental hypodontia etc. on the hook tooth 151 of ratchet 150 and the rack tooth 122 of plunger 120 when can prevent engine start rear chain overtension, and the movement that successfully can allow to retreat displacement and not limit the direction of retreat of plunger 120, and the serviceability etc. the excess impact for ratchet loading spring 160 can avoided and play very well, effect highly significant.

Next, based on Figure 12 to Figure 15, the ratchet-type tensioner of second embodiment of the invention is described.

The ratchet-type tensioner of second embodiment of the invention is compared with the ratchet-type tensioner 100 of above-mentioned first embodiment, it is different that above-mentioned engagement matching mechanism for seedlings and ratchet cancel system concrete arranges form, remaining apparatus structure then without any change part, so be only described in detail the form that arranges of the engagement matching mechanism for seedlings of second embodiment of the invention and the concrete of ratchet cancel system based on Figure 12 to Figure 15.

In addition, about the apparatus structure beyond the engagement matching mechanism for seedlings of second embodiment of the invention and ratchet cancel system, by the reference character being made into compile based on 200 by the marks based on 100 volumes additional on same parts in the ratchet-type tensioner 100 of above-mentioned first embodiment, thus omit its explanation repeated.

At this, though the above-mentioned engagement matching mechanism for seedlings ratchet 250 possessing oval cross section as shown in Figure 13 and not have diagram but to possess to form with the ratchet reception hole 213 of the ratchet 250 roughly shell main body 210 of the oval cross section of similar shape, and present the state making the outer circumferential face of ratchet 250 relative to the inner peripheral surface spline of the ratchet reception hole 213 be arranged on the direction orthogonal with the glide direction of plunger 220.

Thus, for the vibration of the plunger 220 during engine-driving, with engage independently between the rack tooth 222 of plunger side and the hook tooth 251 of ratchet 250, make the outer circumferential face of ratchet 250 relative to the inner peripheral surface spline of ratchet reception hole 213, and the hook tooth 251 of ratchet 250 is correctly engaged in whole facewidth region relative to the rack tooth 222 of plunger side.

And, as shown in figure 14, above-mentioned ratchet 250 possesses the ratchet total length size W being greater than ratchet outside dimension D, thus, even if when assume responsibility for superfluous load on ratchet 250, also can suppress the inclination relative to the incidental ratchet 250 of the glide direction in ratchet reception hole 213, thus prevent the partial wear of ratchet 250.

In addition, in ratchet 250 in the present embodiment, for disperseing mesh loadings equably towards carving the rack tooth 222 being located at plunger side and engage, 2 hook tooths 251 possessed with the space of teeth of rack tooth 222 equal pitch and same tooth depth are set in plunger side front end area as illustrated in fig. 14.(about the concrete of ratchet cancel system, form is set)

Next, illustrate in greater detail the maximum feature of the ratchet-type tensioner 200 of the present embodiment based on Figure 14 and Figure 15, the hook tooth 251 that namely utilizes tool pin T to remove ratchet 250 arranges form relative to the concrete of ratchet cancel system of the engagement of the rack tooth 222 of plunger 220.

First, as shown in Figure 14 and Figure 15, above-mentioned ratchet cancel system is made up of tool pin engagement portion 254 and pin insertion hole 214.Wherein, this tool pin engagement portion 254 is arranged at the plunger side front end area of above-mentioned ratchet 250, and abuts engaging for the pin front end T1 of tool pin T; This pin insertion hole 214 is arranged at above-mentioned shell main body 210 and inserts towards tool pin engagement portion 254 for tool pin T.

That is, as shown in figure 14, the tool pin engagement portion 254 of ratchet 250 is made up of the taper bearing surface 254a plunger side front end area of ratchet 250 being cut away a part towards back-end region side.On the other hand, as shown in figure 15, the pin insertion hole 214 of shell main body 210 is arranged to the taper bearing surface 254a pushing ratchet 250 with tool pin T, to be pushed back in the back-loading direction of ratchet 250 to ratchet 250.

Thus, the pushing force of the tool pin T interted in the pin insertion hole 214 of shell main body 210 has produced the component of following effect, is namely pushed back in the back-loading direction of ratchet 250 to ratchet 250 by taper bearing surface 254a.

In the ratchet-type tensioner 200 of the second embodiment of the invention of such acquisition, the hook tooth 251 removing ratchet 250 is made up of the pin insertion hole 214 of tool pin engagement portion 254 and shell main body 210 relative to the ratchet cancel system of the engagement of the rack tooth 222 of plunger 220.Wherein, described tool pin engagement portion 254 is formed by the taper bearing surface 254a plunger side front end area of ratchet 250 being cut away a part towards back-end region side; Described pin insertion hole 214 is in order to arrange with the taper bearing surface 254a of tool pin T pushing ratchet 250.By such structure, the pushing force of the tool pin T interted in the pin insertion hole 214 of shell main body 210 has produced the component of following effect, namely by taper bearing surface 254a, ratchet 250 is carried out the power pushed back to the back-loading direction of ratchet 250.And, such structure can by easily removing the engagement of hook tooth 251 relative to the rack tooth 222 of plunger 220 of ratchet 250, and pushed back by plunger 220 and make it retreat, so significantly can alleviate the homework burden of the maintenance service such as location and part replacement of ratchet-type tensioner under the state that timing chain is relaxed, timing chain.

And, identical with the ratchet-type tensioner 100 of above-mentioned the first embodiment, make the ratchet mechanism that is made up of plunger 220 and ratchet 250 reliably and stably carry out work, and the distortion avoiding the mistake between the rack tooth 222 of plunger side and the hook tooth 251 of ratchet 250 to assemble causing is to eliminate the misoperation of ratchet mechanism, and the precision optical machinery of the male-female engagement form be made up of spline between the ratchet reception hole 113 at shell main body side that there is no need for being formed as this first embodiment and the outer circumferential face of ratchet 150 is processed, significantly can alleviate it and make burden etc., effect highly significant.

Claims (8)

1. a ratchet-type tensioner, comprising: the shell main body being formed with the oily supply passage of external pressure oil; From the plunger that the plunger reception hole of this shell main body is slidably given prominence to towards chain of advancing; Be incorporated in be formed at described shell main body the high-pressure oil chamber between plunger reception hole and the hollow portion of plunger in, and carry out the plunger loading spring that loads along the projected direction of plunger; Be intercalated in the ratchet reception hole of described shell main body, and the cylindric ratchet slided along the direction orthogonal with the advance and retreat direction of plunger; To the ratchet loading spring that the hook tooth of the plunger side front end area being arranged at this ratchet loads towards the rack tooth of plunger side; The rear end embedding described ratchet reception hole is neighbouring to make the spring locking of ratchet loading spring dropping place fill in, and the feature of described ratchet-type tensioner is:

The ratchet cancel system of hook tooth to the engagement of the rack tooth of described plunger utilizing tool pin to remove described ratchet is made up of tool pin engagement portion and pin insertion hole, described tool pin engagement portion is arranged at the plunger side front end area of described ratchet and the pin front end for tool pin abuts engaging, described pin insertion hole is arranged at described shell main body and towards tool pin engagement portion insertion tool pin

The step-like bearing surface that the tool pin engagement portion of described ratchet is formed between hook tooth and ratchet outer circumferential face by the plunger side front end area at described ratchet is formed, and the pin insertion hole of described shell main body is set to push back ratchet with the step-like bearing surface of described tool pin driving ratchet with the back-loading direction to ratchet.

2. ratchet-type tensioner as claimed in claim 1, is characterized in that:

The active force of described ratchet loading spring is set to be greater than the component of ratchet glide direction plunger being produced when engine start from the counter-force that chain side of advancing retreats, and be less than chain tension after the engine started excessive time plunger is produced from the counter-force that chain side of advancing retreats the component of ratchet glide direction.

3. ratchet-type tensioner as claimed in claim 1, is characterized in that:

The rack tooth of described plunger is formed with concavo-convex by stop surface and slip surface, and described stop surface rolls tiltedly relative to the glide direction of described ratchet to plunger advancement, and described slip surface retreats inclination tiltedly relative to the glide direction of described ratchet to plunger, and

The hook tooth of described ratchet is formed with concavo-convex by stop opposed faces and slip opposed faces, described stop opposed faces rolls tiltedly relative to the glide direction of described ratchet to plunger advancement, and described slip opposed faces retreats inclination tiltedly relative to the glide direction of described ratchet to plunger.

4. ratchet-type tensioner as claimed in claim 3, is characterized in that:

The tilt angle of described stop surface is less than the tilt angle of described slip surface.

5. the ratchet-type tensioner as described in claim 1 or 4, is characterized in that:

In whole facewidth region, non-warping the engagement matching mechanism for seedlings engaged is formed relative to the state of the inner peripheral surface spline of described ratchet reception hole to make the outer circumferential face of described ratchet relative to the rack tooth of described plunger side to make the hook tooth of described ratchet.

6. ratchet-type tensioner as claimed in claim 5, is characterized in that:

Described engagement matching mechanism for seedlings is made up of ratchet side raised line and case side groove, described ratchet side raised line is arranged at the outer circumferential face of described ratchet along glide direction, described case side groove with the state of this ratchet side raised line male-female engagement under to be arranged at the inner peripheral surface of described ratchet reception hole along glide direction.

7. ratchet-type tensioner as claimed in claim 6, is characterized in that:

Described ratchet possesses the ratchet total length size being greater than ratchet outside dimension.

8. ratchet-type tensioner as claimed in claims 6 or 7, is characterized in that:

Described ratchet loading spring is inserted in the spring reception hole of described ratchet along glide direction.