CN201288719Y - Buffer structure for hydraulic cylinder piston rod end - Google Patents
Buffer structure for hydraulic cylinder piston rod end Download PDFInfo
- Publication number
- CN201288719Y CN201288719Y CNU2008202209774U CN200820220977U CN201288719Y CN 201288719 Y CN201288719 Y CN 201288719Y CN U2008202209774 U CNU2008202209774 U CN U2008202209774U CN 200820220977 U CN200820220977 U CN 200820220977U CN 201288719 Y CN201288719 Y CN 201288719Y
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- piston rod
- piston
- sleeve
- hydraulic cylinder
- guide sleeve
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Abstract
A buffer structure, which is applied to the piston rod end of a hydraulic cylinder, comprises a cylinder (13) of the hydraulic cylinder, a guide sleeve (17) arranged at the front end of the cylinder of the hydraulic cylinder, a piston rod (18) installed in a cavity having a rod, and a piston (12) fixed to the tail part of the piston rod, characterized in that the piston rod (18) is in a four-shaft diameter, three section step structure with the shaft diameter changed from big to small and from front to back, and is sequentially arranged with a floating buffer shaft sleeve (15), the piston (12) and a nut sleeve (20), wherein the nominal section of the piston rod is matched with the guide sleeve, the floating buffer shaft sleeve (15) is arranged on the first step shaft section of the piston rod in a radial and axial floating manner; the piston (12) is fixed on the second step shaft section of the piston rod through the nut sleeve (20) arranged on the third step shaft section of the piston rod; the inner diameter of the floating buffer shaft sleeve is larger than the diameter of the first step shaft section, and the outer diameter of which is less than the inner diameter of the guide sleeve (17) having a buffering effect.
Description
Technical field
The utility model relates to a kind of hydraulics, relates to a kind of buffer structure that is applicable to the hydraulic cylinder piston rod end specifically.This structure setting has the unsteady buffering axle sleeve of radial and axial float function, cushions with the hole of guide sleeve, can be used for the occasion that the requirement oil hydraulic cylinder has the tailpiece of the piston rod buffering.
Background technique
In engineering machinery, adopt oil hydraulic cylinder as the executive component in the hydraulic system in a large number, and as the motion rod member in the engineering machinery mechanism.In general, when each mechanism kinematic action of engineering machinery, always wish rod member stable action, reliable, do not stop rapidly suddenly, in order to avoid cause impact and damage to mechanism.Therefore the oil hydraulic cylinder that uses in the engineering machinery motion generally all can satisfy the requirement of mechanism to the oil hydraulic cylinder athletic performance at hydraulic cylinder piston rod end and cylinder tail end design buffer structure.
In the prior art (as shown in Figure 1, 2), the normal buffer structure that adopts of hydraulic cylinder piston rod end is to utilize the inner hole surface φ A of piston one end and guide sleeve matching gap between the periphery φ of rod chamber one side B to carry out the throttling buffering.Piston inner hole bottom surface and guide sleeve be formed space between the end face of rod chamber---and the fluid that is in the buffer cavity to be contained need flow to the hydraulic fluid port of oil hydraulic cylinder rod chamber by the two matching gap of φ A/ φ B, and discharge fluid to hydraulic system.This moment, piston inner hole footpath and the slit of guide sleeve between the axle head of rod chamber were equivalent to a throttle valve, therefore just played buffer function.
But the oil hydraulic cylinder of above-mentioned buffer structure is used in (as the swing arm oil hydraulic cylinder of loader) on the engineering machinery, can find to exist following problem: oil hydraulic cylinder at piston rod when stretching out fully, catching sight of in fact sometimes, oil hydraulic cylinder does not have pooling feature, therefore to piston rod stroke end, it is very fierce to impact.Analyzing the reason that this situation occurs, is because the matching gap between hydraulic cylinder piston endoporus and the guide sleeve cylindrical is too big, does not have the effect of throttling buffering.
By mathematical modeling and design of Simulation, the throttling cushioning effect that discovery will be realized ideal, it is very high that the machining deviation of piston inner hole footpath φ A and guide sleeve cylindrical diameter of axle φ B requires.So-called perfect condition be meant piston, guide sleeve following structural element longitudinal center line mutually between, and between they and the oil hydraulic cylinder longitudinal center line, preferably being in theory coaxality is zero, and the throttling cushioning effect is then decided by the two matching gap of φ A/ φ B fully:
1) outside diameter that cooperates with the cylinder barrel endoporus of piston, the internal orifice dimension that piston cooperates with the piston rod diameter of axle, piston play the diameter of bore φ A of cylinder end buffer function;
2) diameter of axle that cooperates with cylinder barrel of guide sleeve, the diameter of axle φ B of buffering is played in the aperture of guide sleeve supporting piston bar between guide sleeve and the piston.
Yet, because it is zero that the machining accuracy of the said structure key element of piston and guide sleeve can not make their dependent deviation, therefore their assembling backs are in the actual present position of oil hydraulic cylinder inside, between making that they are mutually, and and the longitudinal center line of piston rod, cylinder barrel endoporus between be that suitable eccentricity value is arranged.Just because of the manufacturing cumulative error of each part is very big, so the actual eccentricity value after the piston assembling is sometimes greater than matching gap between the φ A/ φ B of buffer piston hole and guide sleeve cylindrical.Will when the related piston rod of piston enters oil hydraulic cylinder front end guide sleeve axle head and wants to cushion the defect of buffer piston hole bump guide sleeve axle head appear but like this.For fear of the appearance of this phenomenon, design or make and just will consider the matching gap numerical value that amplifies hydraulic cylinder piston buffering aperture φ A and guide sleeve axle head outside diameter φ B, its direct result is exactly to make the tailpiece of the piston rod buffer loss function of oil hydraulic cylinder.
Summary of the invention
The purpose of this utility model provides a kind of buffer structure that is applicable to the hydraulic cylinder piston rod end at existing deficiency in the above-mentioned prior art just.
The purpose of this utility model can realize by following technique measures:
The buffer structure that is applicable to the hydraulic cylinder piston rod end of the present utility model comprises the oil hydraulic cylinder cylinder barrel, is arranged on the guide sleeve of oil hydraulic cylinder cylinder barrel front end, is installed in piston rod in the oil hydraulic cylinder rod chamber and the piston that is fixedly mounted on the piston rod afterbody; Described piston rod is from front to back and the diameter of axle four diameters of axle, three sections step-like structures from large to small, and float buffering axle sleeve, piston and nut sleeve be installed successively, wherein piston rod nominal diameter section cooperates with guide sleeve, the buffering of floating axle sleeve with radially, the axial float mode is installed on first section step shaft part of piston rod, piston is fixedly installed on second section step shaft part of piston rod by the nut sleeve that is installed on the 3rd section step shaft part of piston rod; The internal diameter of described unsteady buffering axle sleeve plays the internal diameter at buffer function place less than guide sleeve greater than first section step shaft section diameter, external diameter.
Described guide sleeve can lead to the axial stretching motion of piston rod, when piston rod when stretching out fully, under the promotion of buffer cavity pressure oil, the taper chamfered end of the buffering of floating axle sleeve enters in the hole of guide sleeve in the mode of axial displacement automatic centering, makes the fluid of the buffer cavity that is positioned at guide sleeve and piston space carry out the throttling buffering by the external diameter of the buffering axle sleeve that floats and the gap in guide sleeve aperture.When the application piston bar is withdrawn, unsteady buffer shaft is enclosed within the pressure oil effect that the rod chamber hydraulic fluid port comes in, move axially to piston side, fluid can be by the endoporus and the gap between the piston rod diameter of axle of the buffering axle sleeve that floats and the gap in float buffering sleeve outer circle and guide sleeve aperture, to the rapid oil-feed in oil hydraulic cylinder rod chamber space, solve the problem of hydraulic cylinder piston rod withdrawal initial start difficulty.
The buffering of floating described in the utility model axle sleeve offers several radially oil grooves near the end face of piston side, the periphery of shaft shoulder step one side of close first section step shaft part of piston rod is the taper chamfering structure, and the length of the buffering axle sleeve that floats is less than the length of first section step shaft part of piston rod; Described guide sleeve is the inner conical chamfering structure towards the nose end place of buffering axle sleeve one side of floating.
Working principle of the present utility model is as follows:
Buffer structure of the present utility model is to utilize the external diameter of the buffering axle sleeve that floats and the matching gap (being equivalent to a throttle valve) of the interior circle of guide sleeve to carry out the throttling buffering.The buffer shaft cover that floats has the radial floating ability, and front end is processed as the taper chamfering, so can automatic centering when entering the guiding trepanning of inner conical chamfering, so just can effectively compensate error owing to form and position tolerances such as coaxality, perpendicularity between each part such as piston that machining error causes, guide sleeve, piston rod; Simultaneously because the function that it has a radial floating has also reduced the accurate to dimension requirement of other parts.
In addition, the buffering of floating axle sleeve can axial float, when piston rod reaches the buffering axle sleeve band taper chamfered part that floats when entering in the guide sleeve fully, when forming pressure chamber (being buffer cavity) between piston and the guide sleeve, the unsteady buffer shaft cover of pressure oil pushing tow is provided with radially this end face of oil groove, the buffering axle sleeve that floats is drawn close toward guide sleeve one side, the end face of its band taper chamfering and the shaft shoulder step of first section step shaft part of piston rod are close to oil sealing, fluid in the above-mentioned like this buffer cavity can only slowly flow to the outside oil extraction of rod chamber hydraulic fluid port between the slit (gap between unsteady buffering sleeve outer circle and guide sleeve aperture) by the buffering matching pair, has played piston and piston rod and the guide sleeve buffer function at the cylinder head place.
When the rod chamber hydraulic fluid port enters pressure oil, pressure oil promote to float the buffering axle sleeve to piston one side shaft to moving, and fit with piston end surface and to contact.At this moment, pressure oil is by the slit of buffering matching pair, slowly to the rod chamber oil-feed; In addition, fluid also can enter in guide sleeve and the formed rod chamber of piston from the gap that unsteady buffer shaft overlaps aperture and first section step shaft part of piston rod diameter of axle rapidly.Have some radially oil grooves on that end face that the buffering axle sleeve contact with piston owing to float, so pressure oil passes through from oil groove radially with regard to very fast, be full of whole rod chamber, the promotion piston makes piston rod do recovery movement.
The beneficial effects of the utility model are as follows: this structure is more reasonable compared to existing technology, cushioning effect is obvious, can not only effectively solve piston rod stretches out when terminal, the buffer problem of cylinder head, make also simultaneously that startup rapidly, has steadily solved the problem of hydraulic cylinder piston rod withdrawal initial start difficulty in the prior art effectively when piston rod is withdrawn.
Description of drawings
Fig. 1 is the prior art constructions schematic representation.
Fig. 2 is the I partial view of Fig. 1.
Fig. 3 is a structural representation of the present utility model
Fig. 4 is the II partial view of Fig. 3.
Sequence number is among Fig. 1 and Fig. 2: 1, piston, 2, cylinder barrel, 3, the bottom surface of piston φ A, 4, the end face of piston external diameter, 5, hydraulic fluid port (rod chamber hydraulic fluid port), 6, piston rod, 7, guide sleeve, 8, the end face of guide sleeve, 9, card key, 10, card key cover, 11, back-up ring (circlip for shaft).
Sequence number is among Fig. 3 and Fig. 4: 12, piston, 13, cylinder barrel, 14, piston end face, 15, the buffering of floating axle sleeve, 16, hydraulic fluid port (rod chamber hydraulic fluid port), 17, guide sleeve, 18, piston rod, 19, the end face of guide sleeve, 20, nut sleeve, 21, screw.
Embodiment
The utility model is further described below with reference to embodiment's (accompanying drawing), but does not limit the utility model.
As shown in Figure 3, the buffer structure that is applicable to the hydraulic cylinder piston rod end of the present utility model comprise oil hydraulic cylinder cylinder barrel 13, be arranged on oil hydraulic cylinder cylinder barrel front end guide sleeve 17, be installed in piston rod 18 in the rod chamber and the piston 12 that is fixedly mounted on the piston rod afterbody.
Described piston rod 18 is from front to back and the diameter of axle four diameters of axle, three sections step-like structures from large to small, and float buffering axle sleeve 15, piston 12 and nut sleeve 20 be installed successively, wherein piston rod nominal diameter section cooperates with guide sleeve, the buffering of floating axle sleeve 15 with radially, the axial float mode is installed on first section step shaft part of piston rod, piston 12 is fixedly installed on second section step shaft part of piston rod by the nut sleeve 20 that is installed on the 3rd section step shaft part of piston rod; The internal diameter of described unsteady buffering axle sleeve is greater than first section step shaft section diameter, the external diameter internal diameter less than 17 buffer function places of guide sleeve.
Described unsteady buffering axle sleeve 15 offers several radially oil grooves near the end face of piston side, the periphery of shaft shoulder step one side (towards guide sleeve one side) of close first section step shaft part of piston rod is the taper chamfering structure, and the length of the buffering axle sleeve 15 that floats is less than the length of first section step shaft part of piston rod; End face 19 place's nose ends of described guide sleeve 17 are the inner conical chamfering structure.
Concrete working principle of the present utility model and mode are as follows:
When piston rod 18 when stretching out fully, the buffering of floating axle sleeve 15 band taper chamfered parts extend in the φ D hole from end face 19 these sides of the band inner conical chamfering of guide sleeve 17, buffering axle sleeve 15 has the radial floating function because float, axle all is inside and outside taper chamfering structures with the hole between the two, so the process that stretches into is understood automatic centering between them.
The annulus of the formation between piston end surface 14 and the guide sleeve end face 19 is buffer cavity.When the oil hydraulic cylinder rodless cavity continues to enter pressure oil pushing tow piston 12, piston 12 and piston rod 18 still travel forward, and make oil liquid pressure in the buffer cavity raise and increase.At this moment the buffering of floating axle sleeve 15 band taper chamfer surfaces axially move to shaft shoulder step one side of 18 first sections step shaft parts of piston rod, and fit with the end face of this shaft shoulder step and to carry out oil sealing.Fluid in the buffer cavity carries out the throttling buffering by the gap of float buffering axle sleeve 15 diameter of axle φ C and guide sleeve 17 aperture φ D, exports to hydraulic system from hydraulic fluid port 16.
For oil hydraulic cylinder, piston rod stretches out the control of stroke, generally can not adopt fully and control by the hydraulic cylinder piston stroke, promptly in Fig. 1, can not allow piston rod 6 stretch out fully after, piston end surface 3 is fitted with guide sleeve end face 8; In Fig. 3, can not allow piston end surface 14 and guide sleeve end face 19 fit.Because for every oil hydraulic cylinder of same plant produced, same specification, their actual size is also incomplete same, so the hydraulic cylinder piston stroke in fact also is not the same.During for many oil hydraulic cylinder parallel operations, control with hydraulic cylinder travel, a result wherein hydraulic cylinder travel finishes, and the another oil hydraulic cylinder is also continuing motion, and this will make the rod member in parallel in the mechanism be subjected to extra load, therefore seems extremely unreasonable.
Reasonably design should be taked mechanical stop limiter in mechanism, when allowing hydraulic cylinder piston rod end buffering finish, is the existing structure of example with Fig. 1,1/3～1/4 of the L1 the when distance L 2 between piston end surface 3 and the guide sleeve end face 8 has just begun for buffering; With Fig. 3 is the model utility structure of example, 1/3～1/4 of the L3 the when distance L 4 when hydraulic cylinder piston rod end buffering finishes between piston end surface 14 and the guide sleeve end face 19 has just begun for buffering.Because distance can't direct observation in the cylinder, have the dimensions so normally allow the piston rod stroke stay, as stay 10mm～30mm to design mechanical stop limiter, make oil hydraulic cylinder almost finish movement travel simultaneously, avoid that rod member is subjected to extra load in the mechanism.
When the application piston bar was withdrawn, the pressure oil that the rod chamber hydraulic fluid port 5 of existing structure is come in can only slowly enter into the rod chamber that forms between piston end surface 3 and the guide sleeve end face 8 by the slit of buffering matching pair φ A/ φ B.Have only when oil pressure is elevated to certain numerical value, just can pushing tow piston end surface 3, add under the acting in conjunction of the pressure oil pushing tow piston end surface 4 of hydraulic fluid port 5, make piston rod 6 produce the withdrawal action.Therefore, from 6 withdrawals of beginning application piston bar, to its real action, needed time is longer, and the action that seems lags behind.
The utility model structure under the pressure oil effect that rod chamber hydraulic fluid port 16 is come in, the buffering of floating axle sleeve 15 towards piston end surface 14 1 side shafts to moving.The ring-type rod chamber that have two routes to form between piston end surface 14 and guide sleeve end face 19 this moment is oil-filled:
One, oil-filled toward rod chamber from the slit of buffering matching pair φ C/ φ D, this route oil-feed is very slow;
Its two because the buffering axle sleeve endoporus φ E that floats is much bigger with respect to the slit of buffering matching pair φ C/ φ D with the gap of piston rod diameter of axle φ F, so fluid is by this slit, cushion axle sleeve by floating again some radially oil groove can be full of rod chamber very soon.
Owing to two routes are arranged to the rapid oil transportation in oil hydraulic cylinder rod chamber space, have therefore also just solved the problem of hydraulic cylinder piston rod withdrawal initial start difficulty in the prior art.
The utility model is applicable in the hydraulic system that particularly relatively large to cylinder diameter hydraulic fluid cylinder pressure for guaranteeing its normal use, seems more suitable because of piston rod stretches out the occasion that excessive velocities, tailpiece of the piston rod need cushion.
Claims (3)
1, a kind of buffer structure that is applicable to the hydraulic cylinder piston rod end, it comprises oil hydraulic cylinder cylinder barrel (13), be arranged on the guide sleeve (17) of oil hydraulic cylinder cylinder barrel front end, be installed in the piston rod (18) in the rod chamber, and the piston (12) that is fixedly mounted on the piston rod afterbody, it is characterized in that: described piston rod (18) is for from front to back, and the diameter of axle four diameters of axle from large to small, three sections step-like structures, and the buffering axle sleeve (15) that floats is installed successively, piston (12) and nut sleeve (20), wherein piston rod nominal diameter section cooperates with guide sleeve, float buffering axle sleeve (15) with radially, the axial float mode is installed on first section step shaft part of piston rod, and piston (12) is fixedly installed on second section step shaft part of piston rod by the nut sleeve (20) that is installed on the 3rd section step shaft part of piston rod; The internal diameter of described unsteady buffering axle sleeve plays the internal diameter at buffer function place less than guide sleeve (17) greater than first section step shaft section diameter, external diameter.
2, buffer structure according to claim 1, it is characterized in that: described unsteady buffering axle sleeve (15) offers several radially oil grooves near the end face of piston side, the periphery of shaft shoulder step one side of close first section step shaft part of piston rod is the taper chamfering structure, and the length of the buffering axle sleeve (15) that floats is less than the length of first section step shaft part of piston rod.
3, buffer structure according to claim 1 is characterized in that: described guide sleeve (17) is the inner conical chamfering structure towards end face (19) the nose end place of buffering axle sleeve (15) one sides of floating.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008202209774U CN201288719Y (en) | 2008-11-17 | 2008-11-17 | Buffer structure for hydraulic cylinder piston rod end |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008202209774U CN201288719Y (en) | 2008-11-17 | 2008-11-17 | Buffer structure for hydraulic cylinder piston rod end |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201288719Y true CN201288719Y (en) | 2009-08-12 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU2008202209774U Expired - Fee Related CN201288719Y (en) | 2008-11-17 | 2008-11-17 | Buffer structure for hydraulic cylinder piston rod end |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201288719Y (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102155460A (en) * | 2010-07-23 | 2011-08-17 | 三一重工股份有限公司 | Hydraulic oil cylinder and related devices of hydraulic oil cylinder, and hydraulic buffer system, excavator and concrete pump truck |
| CN102155461A (en) * | 2010-07-23 | 2011-08-17 | 三一重工股份有限公司 | Hydraulic oil cylinder, hydraulic buffer system, excavator and concrete pump truck |
| CN102384125A (en) * | 2011-05-24 | 2012-03-21 | 四川重汽王牌兴城液压件有限公司 | Hydraulic executing device of heavy truck dumper |
| CN110469558A (en) * | 2019-09-18 | 2019-11-19 | 三一汽车起重机械有限公司 | Centering oil cylinder and crane with bidirectional buffering |
-
2008
- 2008-11-17 CN CNU2008202209774U patent/CN201288719Y/en not_active Expired - Fee Related
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102155460A (en) * | 2010-07-23 | 2011-08-17 | 三一重工股份有限公司 | Hydraulic oil cylinder and related devices of hydraulic oil cylinder, and hydraulic buffer system, excavator and concrete pump truck |
| CN102155461A (en) * | 2010-07-23 | 2011-08-17 | 三一重工股份有限公司 | Hydraulic oil cylinder, hydraulic buffer system, excavator and concrete pump truck |
| CN102155461B (en) * | 2010-07-23 | 2012-06-27 | 三一重工股份有限公司 | Hydraulic oil cylinder, hydraulic buffer system, excavator and concrete pump truck |
| CN102155460B (en) * | 2010-07-23 | 2012-07-04 | 三一重工股份有限公司 | Hydraulic oil cylinder and related devices of hydraulic oil cylinder, and hydraulic buffer system, excavator and concrete pump truck |
| CN102384125A (en) * | 2011-05-24 | 2012-03-21 | 四川重汽王牌兴城液压件有限公司 | Hydraulic executing device of heavy truck dumper |
| CN102384125B (en) * | 2011-05-24 | 2014-01-15 | 四川重汽王牌兴城液压件有限公司 | Hydraulic executing device of heavy truck dumper |
| CN110469558A (en) * | 2019-09-18 | 2019-11-19 | 三一汽车起重机械有限公司 | Centering oil cylinder and crane with bidirectional buffering |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20090812 Termination date: 20131117 |