CN108779789A - Fluid-pressure cylinder - Google Patents

Abstract

Hydraulic cylinder (100) includes：Buffer part (40) makes near the stroke end when elongation acts piston rod (20) slow down；And abutting part (51), it is abutted for buffer part (40) near the stroke end when elongation acts, buffer part (40) has：Buffering ring (41) delimit buffering access (42)；And banking pin (45), it is being accommodated in limitation buffering ring (41) relative movement relative to piston rod (20) in the state of endless groove (25) of the peripheral surface of piston rod (20) formation, as buffering ring (41) near the stroke end when elongation acts and abutting part (51) abut, banking pin (45) is deviate from from endless groove (25) and buffering ring (41) is allowed relative to the relative movement of piston rod (20), and the working oil of bar side room (1) is discharged by buffering access (42) from supply and discharge access (4).

Description

Fluid-pressure cylinder

Technical field

The present invention relates to a kind of fluid-pressure cylinders.

Background technology

A kind of fluid-pressure cylinder with buffer gear is disclosed in JP2012-172693A.JP2012-172693A institutes Disclosed buffer gear has the bar recess portion for the peripheral surface for being opened on piston rod, can slidably be embedded in the peripheral surface of piston rod Movable sleeve, be opened on movable sleeve sleeve inner peripheral surface channel-shaped slit and for make movable sleeve from piston The spring that separation and the direction gone towards cylinder cap exert a force to movable sleeve.

In fluid-pressure cylinder disclosed in JP2012-172693A, buffer gear passes through the stroke end when elongation acts End nearby makes movable sleeve be connected to cylinder cap, to which the flowing for directly flowing out the slave bar side room of working fluid to supply and discharge mouth switches For the flowing of working fluid flowed out to supply and discharge mouth by slit and bar recess portion.It is utilized as a result, to the working fluid by slit Flowing apply resistance so that piston rod is smoothly slowed down, play pooling feature.

Invention content

In fluid-pressure cylinder disclosed in JP2012-172693A, in order to which make near the stroke end when elongation acts can Moving sleeve and piston rod relatively move and play pooling feature, and so that movable sleeve and piston rod is moved together in contractive action It is dynamic, using set on the movable sleeve of the indoor spring-loaded of bar side.

But if being equipped with spring in bar side room as the fluid-pressure cylinder, overall length can elongated corresponding length And keep fluid-pressure cylinder enlarged.

Present invention aims to fluid-pressure cylinder miniaturizations.

A certain technical solution according to the present invention, provides a kind of fluid-pressure cylinder, wherein the fluid-pressure cylinder includes：Cylinder body；It is living Stopper rod is inserted into cylinder body；Piston links with the top of piston rod, and will be divided into bar side room and bottom side room in cylinder body；Buffering Portion, is set to the periphery of piston rod, and so that piston rod is slowed down near the stroke end when elongation acts；Supply and discharge access, with bar Side room is connected to, and the working fluid for feeding to the working fluid of bar side room supply and being discharged from bar side room passes through；And abutting part, it sets It in cylinder body, and is abutted for buffer part near the stroke end when elongation acts, buffer part has：Buffering ring is acted in elongation When stroke end nearby be connected to abutting part；And limiting unit, in the recess portion that the peripheral surface being accommodated in piston rod is formed Relative movement of the buffering ring relative to piston rod is limited under state, with buffering ring near the stroke end when elongation acts and is supported Socket part abuts, and supply and discharge access is blocked with being directly connected to for bar side room by buffering ring, and limiting unit is deviate from from recess portion and buffered Ring is allowed relative to the relative movement of piston rod, the working fluid of bar side room by by working fluid apply resistance Access is buffered to be discharged from supply and discharge access.

Description of the drawings

Fig. 1 is the sectional view of the fluid-pressure cylinder of the 1st embodiment of the present invention.

Fig. 2 is the enlarged cross-sectional view of the buffer part for the fluid-pressure cylinder for indicating the 1st embodiment of the present invention.

Fig. 3 A are the vertical views of the buffering ring for the fluid-pressure cylinder for indicating the 1st embodiment of the present invention.

Fig. 3 B are the vertical views of the variation of the buffering ring for the fluid-pressure cylinder for indicating the 1st embodiment of the present invention.

Fig. 4 is the enlarged cross-sectional view of the buffer part for the fluid-pressure cylinder for indicating the 1st embodiment of the present invention, is to indicate to limit The figure of the length of pin.

Fig. 5 is the enlarged cross-sectional view of the buffer part for the fluid-pressure cylinder for indicating the 1st embodiment of the present invention, indicates piston rod The state near stroke end when being acted in elongation.

Fig. 6 is the enlarged cross-sectional view of the buffer part for the fluid-pressure cylinder for indicating the 1st embodiment of the present invention, indicates buffering ring The state that relative movement relative to piston rod is allowed.

Fig. 7 is the enlarged cross-sectional view of the buffer part for the fluid-pressure cylinder for indicating the 1st embodiment of the present invention, is to indicate from stretching The stroke end of long action carries out the figure of the state of contractive action.

Fig. 8 is the enlarged cross-sectional view of the buffer part for the fluid-pressure cylinder for indicating the 1st embodiment of the present invention, indicates banking pin The state opposite with endless groove.

Fig. 9 is the enlarged cross-sectional view of the buffer part for the fluid-pressure cylinder for indicating the 1st embodiment of the present invention, indicates that buffering is logical Road is formed in the variation of buffering ring.

Figure 10 is the enlarged cross-sectional view of the buffer part for the fluid-pressure cylinder for indicating the 1st embodiment of the present invention, indicates buffering Access is formed in the variation of piston rod.

Figure 11 is the enlarged cross-sectional view of the buffer part for the fluid-pressure cylinder for indicating the 1st embodiment of the present invention, indicates buffering Access is formed in the 1st variation of abutting part.

Figure 12 is the enlarged cross-sectional view of the buffer part for the fluid-pressure cylinder for indicating the 1st embodiment of the present invention, indicates buffering Access is formed in the 2nd variation of abutting part.

Figure 13 is the enlarged cross-sectional view of the buffer part for the fluid-pressure cylinder for indicating the 2nd embodiment of the present invention.

Figure 14 is the enlarged cross-sectional view of the buffer part for the fluid-pressure cylinder for indicating the 2nd embodiment of the present invention, indicates limitation 1st variation of ring.

Figure 15 is the enlarged cross-sectional view of the buffer part for the fluid-pressure cylinder for indicating the 2nd embodiment of the present invention, indicates limitation 2nd variation of ring.

Figure 16 is the enlarged cross-sectional view of the buffer part for the fluid-pressure cylinder for indicating the 2nd embodiment of the present invention, indicates piston Bar is in the state near stroke end when elongation acts.

Figure 17 is the enlarged cross-sectional view of the buffer part for the fluid-pressure cylinder for indicating the 2nd embodiment of the present invention, indicates buffering The state that ring is allowed relative to the relative movement of piston rod.

Figure 18 is the enlarged cross-sectional view of the buffer part for the fluid-pressure cylinder for indicating the 3rd embodiment of the present invention.

Figure 19 is the vertical view of the scaling ring for the fluid-pressure cylinder for indicating the 3rd embodiment of the present invention.

Figure 20 is the enlarged cross-sectional view of the buffer part for the fluid-pressure cylinder for indicating the 3rd embodiment of the present invention, indicates piston Bar is in the state near stroke end when elongation acts.

Figure 21 be indicate the present invention the 3rd embodiment fluid-pressure cylinder buffer part enlarged cross-sectional view, be indicate from The stroke end of elongation action carries out the figure of the state of contractive action.

Figure 22 is the sectional view for the fluid-pressure cylinder for indicating the comparative example of the present invention.

Specific implementation mode

Hereinafter, being described with reference to the fluid-pressure cylinder of embodiments of the present invention.Hereinafter, being by working oil to fluid-pressure cylinder The case where hydraulic cylinder driven as working fluid, illustrates.

(the 1st embodiment)

As shown in Figure 1, the hydraulic cylinder 100 of the 1st embodiment includes：The cylinder body 10 of tubular；Piston rod 20 is inserted into cylinder body 10；Piston 30 links with the top of piston rod 20 and is slided along the inner peripheral surface of cylinder body 10；And buffer part 40, it is set to The periphery of piston rod 20.

The inside of cylinder body 10 is divided into bar side room 1 and the two the fluid pressure chambers of bottom side room 2 by piston 30.100 profit of hydraulic cylinder Expanding-contracting action is carried out with the working hydraulic pressure of bar side room 1 or bottom side room 2 is imported from hydraulic power source (working fluid potential source).Cylinder body 10 It is sealed by containment member (illustration omitted) between inner circumferential and the periphery of piston 30.Bar side room 1 and bottom side room 2 pass through cylinder as a result, Connection between the inner circumferential and the periphery of piston 30 of body 10 is blocked.

The inner peripheral surface of cylinder body 10 has that the sliding surface 11 slided for piston 30, internal diameter forms larger compared with sliding surface 11 Big diametral plane 12 and the inner circumferential stage portion 13 that is formed between sliding surface 11 and big diametral plane 12.Big diametral plane 12 from cylinder body 10 one The opening portion 10A at end is continuously formed.It is formed in inner circumferential stage portion 13 with being gone from big diametral plane 12 towards sliding surface 11 and interior The taper surface 13A that diameter becomes smaller.

It is equipped with the opening portion 10A sealings of one end in cylinder body 10 and is the cylindrical shape slid freely by the bearing of piston rod 20 Cylinder cap 50.Cylinder cap 50 is connected to the abutting part of buffer part 40 near the stroke end with the piston rod 20 when elongation acts 51.Abutting part 51 is formed as cylindric, and is inserted into the inside of cylinder body 10.Cylinder cap 50 is by the multiple fastening spiral shells arranged in the circumferential Bolt (illustration omitted) is anchored on cylinder body 10.

It is clamped with bushing 55, secondary sealing part 56, primary seal 57 and dust seal 58 in the inner circumferential of cylinder cap 50.

By the peripheral surface sliding contact of bushing 55 and piston rod 20, piston rod 20 is supported to the axis along cylinder body 10 It moves in direction.

The supply and discharge mouth 3 being connected to hydraulic power source is formed in cylinder cap 50.Cylinder cap 50 utilizes the path groove 50A for being formed in inner peripheral surface The supply and discharge access 4 for making supply and discharge mouth 3 and bar side room 1 be connected to delimited between piston rod 20 at it.Pass through supply and discharge access from supply and discharge mouth 3 4 supply working oil to bar side room 1 or working oil are discharged from bar side room 1.

Piston rod 20 has with the main part 21 of the inner circumferential sliding contact of cylinder cap 50, outer diameter is formed compared with main part 21 Smaller small diameter portion 22, the cricoid stage portion 23 being formed between main part 21 and small diameter portion 22 and it is formed in piston rod 20 Top and for piston 30 fasten threaded portion 24.

As depicted in figs. 1 and 2, in small diameter portion 22, the ring-type as recess portion is formed in the position adjacent with stage portion 23 Slot 25.Endless groove 25, which has, to be connect with the peripheral surface of small diameter portion 22 and with being gone towards 30 side of piston and slot taper that depth becomes smaller Portion 25A.

Piston 30 and the threaded portion 24 of piston rod 20 are screwed, and are anchored on piston rod 20 using scheduled fastening force.

Buffer part 40 is set to the periphery of the small diameter portion 22 of piston rod 20 and is set to stage portion 23 and piston in the axial direction Between 30.As shown in fig. 2 and fig. 3 a, buffer part 40 has：Buffering ring 41, delimit have to by working oil apply resistance Buffer access 42；And the banking pin 45 as limiting unit, engaging in buffering ring 41, and locally it is being accommodated in piston rod 20 Small diameter portion 22 endless groove 25 in the state of relative movement of the limitation buffering ring 41 relative to piston rod 20.

As shown in Fig. 2, buffering ring 41 can slidably be embedded in the small diameter portion 22 of piston rod 20.The outer diameter shape of buffering ring 41 At the internal diameter for obtaining the sliding surface 11 less than cylinder body 10.

As shown in fig. 2 and fig. 3 a, it delimited in buffering ring 41 using the multiple through holes penetrated through in the axial direction a plurality of slow Rush access 42.Buffering access 42 makes bar side room 1 and supply and discharge access 4 in the state that buffering ring 41 is connected to abutting part 51 Connection (with reference to Fig. 5).That is, buffering access 42 is formed as being opened on face in the end face opposite with cylinder cap 50 of buffering ring 41 To the position of supply and discharge access 4.

Resistance is applied to the flowing of the working oil by buffering access 42.It is right by making working oil pass through buffering access 42 Bar side room 1 acts on compensator or trimmer pressure.As a result, in hydraulic cylinder 100, the buffering of elongation speed reduction is played near extended travel end Effect.

In addition, the end face opposite with piston 30 in buffering ring 41 be formed with radially extend and respectively with buffering access The a plurality of radial slot 46 of 42 connections.By importing the pressure of working oil to radial slot 46 come when promoting aftermentioned such contractive action Buffering ring 41 and piston 30 from abut state separation.

Alternatively, it is also possible to as shown in Figure 3B, radial slot 46 is not formed in communicatively with buffering access 42 from buffering access 42 The position of offset.In addition, radial slot 46 can also be opened on the peripheral surface of buffering ring 41.In this way, as long as radial slot 46 is formed as It is at least formed partially in the end face of the buffering ring 41 opposite with piston 30 of buffering ring 41 and guides the pressure of working oil and promote The separation of buffering ring 41 and piston 30, it will be able to be formed as arbitrary shape.In addition, in Fig. 2, Fig. 4~Fig. 8, shown with dotted line Meaning ground indicates buffering access 42 and radial slot 46.

The inserting hole 47 for being opened on inner peripheral surface and peripheral surface is formed in buffering ring 41.As shown in Fig. 2, banking pin 45 is inserted into The inserting hole 47 of buffering ring 41, and run through the inner peripheral surface and peripheral surface of buffering ring 41 radially.Banking pin 45 is along buffering ring Inserting hole 47 is inserted into 41 move radially freely.

As shown in figure 4, the length L of banking pin 45 is longer than between the small diameter portion 22 of piston rod 20 and the sliding surface 11 of cylinder body 10 Annulus radial width W1.

Banking pin 45 is moved in the radial outside with its state opposite with the sliding surface 11 of cylinder body 10 towards cylinder body 10 as a result, When the dynamic and end 45A of the radial outside in cylinder body 10 of banking pin 45 is connected to sliding surface 11, it is able to maintain that banking pin 45 It is accommodated in the state in endless groove 25 in the end 45B of radially inner side.Therefore, banking pin 45 is limited from endless groove 25 to deviate from. Thus, buffering ring 41 is held in piston rod 20 using banking pin 45, in the axial direction for limiting buffering ring 41 and piston rod 20 Relative movement.In addition, " limitation axial direction on relative movement " and not comprising the shape to being accommodated in banking pin 45 in endless groove 25 The meaning that the relative movement of buffering ring 41 and piston rod 20 is limited under state, but to banking pin 45 from endless groove 25 deviate from and The meaning that the case where making a relative move is limited.

In addition, being shorter in length than for banking pin 45 delimited between the big diametral plane 12 of cylinder body 10 and the small diameter portion 22 of piston rod 20 Annulus radial width W2 (with reference to Fig. 4).Thus, banking pin 45 is in its state opposite with the big diametral plane 12 of cylinder body 10 It is lower become can to radial outside is mobile and state (reference Fig. 5) that the end 45B of radially inner side deviate from from endless groove 25.If limit Cotter 45 is moved to radial outside, then the end 45B of radially inner side deviates from from endless groove 25, guarantor of the piston rod 20 to buffering ring 41 It holds and is released from.The relative movement in the axial direction of buffering ring 41 and piston rod 20 is allowed as a result,.In addition, in buffering ring 41 and supporting In the state that socket part 51 abuts, between banking pin 45 is equipped between inner circumferential stage portion 13 in axial direction at it as shown in Figure 5 and Figure 6 Gap.

Then, illustrate the action of hydraulic cylinder 100.

If hydraulic power source is connected to bottom side room 2, working fluid case (illustration omitted) is connected to bar side room 1, then working oil is the bottom of to Side room 2 supplies, and the working oil in bar side room 1 is discharged to working fluid case.Therefore, hydraulic cylinder 100 carries out elongation action.

As shown in Fig. 2, when elongation acts, in the banking pin 45 of buffer part 40 shape opposite with the sliding surface 11 of cylinder body 10 Under state, the movement to radial outside of banking pin 45 is limited by sliding surface 11.Therefore, the end of the radially inner side of banking pin 45 45B maintains the state for being incorporated in endless groove 25.In other words, the end 45B of the radially inner side of banking pin 45 is made to be intended to from ring-type Slot tapered portion 25A is crossed in the bottom of slot 25 towards small diameter portion 22, since the end 45A of radial outside takes the lead in being connected to sliding surface 11, therefore banking pin 45 will not be deviate from from endless groove 25.Thus, in this state, maintains buffering ring 41 and be held in piston rod 20 state, buffer part 40 are moved with 20 1 prolonging direction in the same direction of piston rod.Movement with from piston rod 20 to prolonging direction, bar The working oil in side room 1 is imported directly supply and discharge access 4, and is discharged by supply and discharge mouth 3.

If the elongation action using hydraulic cylinder 100 makes piston rod 20 be moved near extended travel end as shown in Figure 5, Then banking pin 45 is opposite with the big diametral plane 12 of cylinder body 10, and buffering ring 41 is connected to the abutting part 51 of cylinder cap 50.If buffering ring 41 and abutting part 51 abut, then direct be connected to of supply and discharge access 4 and bar side room 1 is blocked.

In addition, in hydraulic cylinder 100, be configured to, during piston rod 20 is moved to prolonging direction, banking pin 45 with The opposite opportunity of big diametral plane 12 is slightly sooner in time than the opportunity that buffering ring 41 and abutting part 51 abut.

From the state that buffering ring 41 and abutting part 51 abut, if piston rod 20 is further moved to prolonging direction, limit Cotter 45 is by being released to radial outside mobile by the slot tapered portion 25A guiding of endless groove 25.At this point, big diametral plane 12 will not be with Banking pin 45 contacts and limits the movement of banking pin 45, but allows the movement to radial outside of banking pin 45.

Thus, as shown in fig. 6, the end 45B of the radially inner side of banking pin 45 from endless groove 25 deviate from and piston rod 20 is right The holding of buffering ring 41 is released from.Relative movement of the piston rod 20 relative to buffering ring 41 to prolonging direction as a result, is allowed.This Sample, the slot tapered portion 25A for being formed in endless groove 25 are equivalent to abjection guide portion, the state abutted from buffering ring 41 and abutting part 51 It rises, as piston rod 20 is moved to prolonging direction, which releases to radial outside by banking pin 45 and make it from ring Shape slot 25 is deviate from.

If piston rod 20 is further moved to prolonging direction, the work of the bar side room 1 between buffering ring 41 and piston 30 Oil is imported into supply and discharge access 4 and supply and discharge mouth 3 (referring to Fig.1) by buffering access 42, and is discharged from bar side room 1.Due to passing through The flowing for buffering the working oil of access 42 is applied with resistance, therefore acts on the resistance for having and being applied by buffering access 42 to bar side room 1 The corresponding compensator or trimmer pressure of power.In this way, having played the pooling feature near the extended travel end of piston rod 20.

If hydraulic power source is connected to bar side room 1, working fluid case is connected to bottom side room 2, then working oil is supplied to bar side room 1, Working oil in bottom side room 2 is discharged to working fluid case.Therefore, hydraulic cylinder 100 carries out contractive action.

When the extended travel end for being connected to buffering ring 41 from piston 30 carries out contractive action, first, lead to using from supply and discharge The working oil that road 4 imports makes buffering ring 41 and 20 1 shrinkage direction in the same direction of piston rod move and banking pin 45 and inner circumferential stage portion 13 The corresponding distance of axial gap.In this way, by being equipped with axial gap between banking pin 45 and inner circumferential stage portion 13, from stretching It so that buffering ring 41 and abutting part 51 is detached during the contractive action that long stroke end carries out, and make supply and discharge access 4 It is directly connected to bar side room 1.Working oil is rapidly flowing into bar side room 1 as a result, it is ensured that response when contractive action.

If buffering ring 41 and piston rod 20 move the axial gap with banking pin 45 and inner circumferential stage portion 13 to shrinkage direction Corresponding distance, then as shown in fig. 7, banking pin 45 and inner circumferential stage portion 13 abut.At this point, due to the radially inner side of banking pin 45 End 45B and piston rod 20 small diameter portion 22 peripheral surface sliding contact, therefore banking pin 45 cannot be to radially inner side into one Moved further.That is, the end 45A of radial outside will not cross inner circumferential stage portion 13 towards the sliding surface 11 of cylinder body 10.Cause This, buffering ring 41 is using banking pin 45 engaging in the inner circumferential stage portion 13 of cylinder body 10.In this state, mainly pass through supply and discharge access 4, the gap between the inner peripheral surface of the periphery and cylinder body 10 of the gap between abutting part 51 and buffering ring 41 and buffering ring 41 will The pressure of working oil imports radial slot 46 and acts on the end face of piston 30.Buffering ring 41 and piston 30 detach as a result, piston rod 20 relatively move relative to buffering ring 41 to shrinkage direction.In this way, radial slot 46 is functioned as pressure lead-in groove, promote to receive The separation of buffering ring 41 and piston 30 when contracting acts.By being equipped with radial slot 46, the work in the pressure of working oil can be prevented It is pressed against the inner circumferential stage portion 13 of cylinder body 10 with lower banking pin 45 and causes banking pin 45 and inner circumferential stage portion 13 that breakage occurs.

As shown in figure 8, if piston rod 20 is moved to the end 45B and piston of the radially inner side of banking pin 45 to shrinkage direction Until the endless groove 25 of bar 20 is opposite, then the movement of the radially inner side to cylinder body 10 of banking pin 45 is allowed.Pass through buffering ring 41 bear the fluid force of the working oil supplied to bar side room 1, and the end 45A of the radial outside of banking pin 45 is by inner circumferential stage portion 13 Taper surface 13A guiding and the banking pin 45 is released to radially inner side.The inner circumferential stage portion of banking pin 45 and cylinder body 10 as a result, 13 locking is released from, and the end 45B of radially inner side is accommodated in the endless groove 25 of piston rod 20 again.It keeps again in this way It is moved with 20 1 shrinkage direction in the same direction of piston rod in the buffering ring 41 of piston rod 20.In this way, the taper surface 13A of inner circumferential stage portion 13 It is equivalent to storage guide portion, from the state that buffering ring 41 and abutting part 51 abut, as piston rod 20 is moved to shrinkage direction, Banking pin 45 is released to radially inner side and it is made to be accommodated in endless groove 25 by the storage guide portion.

As above, in hydraulic cylinder 100, buffering ring 41 is limited relative to piston rod 20 by using banking pin 45 Relative movement, buffering ring 41 are moved to 20 1 prolonging direction in the same direction of piston rod until being connected to abutting part 51.It is acted in elongation When stroke end near, by making buffering ring 41 be connected to abutting part 51 and allowing the relative movement of buffering ring 41 and piston rod 20 To play pooling feature.In addition, in hydraulic cylinder 100, since in contractive action, banking pin 45 is accommodated in piston rod 20 again, Therefore buffering ring 41 can be made to be held in piston rod 20 again and be moved with 20 1 shrinkage direction in the same direction of piston rod.Thus, even if It is not provided with spring in bar side room 1, so that buffer part 40 and piston rod 20 is relatively moved when playing pooling feature, and receiving Contracting makes buffer part 40 be moved with 20 1 shrinkage direction in the same direction of piston rod when acting.Thus, it is possible to shorten the overall length of hydraulic cylinder 100 and Make its miniaturization.

If in addition, what the gap in axial direction of the bar side room 1 equipped with spring, especially spring contraction and between wire rod became smaller In the case of, sometimes pressure difference is generated in the inner side and outer side of spring.If causing spring to be lost because of such pressure difference, buffer The action in portion 40 becomes unstable, there is the possibility that cannot play consistently pooling feature.In contrast, in hydraulic cylinder 100 In the case of, due to bar side room 1 be not provided with spring but utilize banking pin 45 support buffering ring 41, can prevent because Losing for spring and the state of affairs as pooling feature cannot be played consistently.

Here, in order to make the present invention be readily appreciated that, the hydraulic cylinder 400 of comparative example is illustrated with reference to Figure 22.Pair with hydraulic cylinder 100 Identical structure marks identical reference numeral and omits the description.

The hydraulic cylinder 400 of comparative example includes going set on the buffering bearing 340 of the tubular of the periphery of piston rod 20 and in elongation Cheng Duan nearby allows to buffer the bearing receiving part 351 that bearing 340 enters.

In hydraulic cylinder 400, by making buffering bearing 340 enter in bearing receiving part 351 near extended travel end Side forms buffering access 342.By make the working oil of bar side room 1 pass through buffering access 342 be discharged, to bar side room 1 effect with The corresponding compensator or trimmer pressure of resistance applied by buffering access 342.In hydraulic cylinder 400, piston 30 that compensator or trimmer pressure is acted on Compression area is equivalent to the area between the periphery and the periphery of piston 30 of buffering bearing 340.

In contrast, since the hydraulic cylinder 100 of present embodiment does not have buffering bearing 340 as comparative example, The compression area of compensator or trimmer pressure is equivalent to the area between the periphery and the periphery of piston 30 of the small diameter portion 22 of piston rod 20.Cause This, can make the section of the compression area of hydraulic cylinder 100 buffering bearing 340 bigger than the compression area of the hydraulic cylinder 400 of comparative example Long-pending size.Thus, in hydraulic cylinder 100, even if in the case where playing identical cushion performance, since compression area becomes Greatly, therefore compared with hydraulic cylinder 400 compensator or trimmer pressure can also be reduced.Since compensator or trimmer pressure can be reduced, in hydraulic cylinder 100 In, bear the cylinder body 10 of compensator or trimmer pressure, piston 30, cylinder cap 50 intensity can also be smaller, manufacturing cost can be reduced.

In addition, in the hydraulic cylinder 400 for having buffering bearing 340, there is buffering bearing 340 by the stage portion of piston rod 20 23 and it is screwed to the mode that the piston 30 of piston rod 20 is clamped in the axial direction.In such hydraulic cylinder 400 from extended travel When end carries out contractive action, supply and discharge access 4 is connected by buffering access 342 until buffering bearing 340 from bearing with bar side room 1 Until receiving part 351 is detached from.When buffering bearing 340 is detached from from bearing receiving part 351, the flow path area of working oil can be sharp Expand, exists and pressure oscillation drastically and the variation of operating rate (movement speed of piston 30) occurs and generates in bar side room 1 The possibility of extraordinary noise etc..In contrast, in the hydraulic cylinder 100 of present embodiment, since buffering ring 41 and abutting part 51 are fast Detach fastly and supply and discharge access 4 is directly connected to bar side room 1, thus can prevent by drastically pressure oscillation and operating rate become It is dynamic to cause to generate extraordinary noise etc..

In addition, in the hydraulic cylinder 400 for having buffering bearing 340, there is stage portion of the buffering bearing 340 in piston rod 20 23 and be screwed to piston rod 20 piston 30 between with mode (the so-called floating support being arranged with gap in axial direction Construction).In such hydraulic cylinder 400, slot is formed in the peripheral surface of piston rod 20 sometimes, tool is equipped in the slot of piston rod 20 There is the buffer sealing part of joint gap.In the hydraulic cylinder 400, the working oil of bar side room 1 using buffering access 342 and buffers close The joint gap of sealing applies resistance to working oil and plays pooling feature.In addition, being equipped with buffering in the inside of buffering bearing 340 In the case of sealing element, hydraulic cylinder can be easily adjusted by sharing buffering bearing 340 and adjusting the size of joint gap 400 cushion performance.

In contrast, in hydraulic cylinder 100, due to can be slow to be easily adjusted by adjusting the size of buffering access 42 Punching performance, therefore the slot of buffer sealing part and the piston rod 20 for storing the buffer sealing part need not be formed.Thus, in liquid In cylinder pressure 100, it can be easily adjusted cushion performance, and due to reducing machining period, system can be further decreased Cause this.

Then, illustrate the variation of the 1st embodiment.

In above first embodiment, buffering access 42 is formed at the through hole of buffering ring 41.It can also take and generation It, buffering access 42 is formed in orifice plug, which is detachably installed on buffering ring 41.In this case, pass through standard The standby multiple orifice plugs for being formed with the different buffering access 42 of diameter, can be easily adjusted cushion performance, and due to can Make 41 sharing of buffering ring, therefore manufacturing cost can be reduced.In addition it is also possible to be the section for preparing to be formed with buffering access 42 Stream plug and the sealing-plug that buffering access 42 is not formed, the orifice plug and sealing-plug of buffering ring 41 are installed on by arbitrarily changing Quantity adjust cushion performance.

In addition, buffering access 42 can also be single through hole.Also, buffering access 42 may not be through hole. Such as the cricoid access delimited by the inner peripheral surface of the peripheral surface of piston rod 20 and buffering ring 41 can also be set as to buffering access 42.In addition, as shown in figure 9, buffering access 42 can also be formed in buffering ring 41 the end face opposite with abutting part 51 it is narrow Seam.

Further, it is expected that buffering access 42 is formed in buffering ring 41.Due to buffering ring 41 and piston rod 20, cylinder cap 50 Compared to being small-sized and be size easy to process, therefore high-precision and buffering access 42 can be readily formed.But buffering is logical Road 42 can also for example be formed in piston rod 20 as shown in Figure 10.In addition, as shown in Figure 11, Figure 12, access 42 is buffered Access, the slit of abutting part 51 can be formed at.

In addition, recess portion may not be endless groove 25, as long as banking pin 45 can be stored, it will be able to be formed as arbitrary Shape.For example, recess portion may not be is formed at the part in circumferential direction across the cricoid form of the complete cycle of piston rod 20 Recess.In addition, banking pin 45 can also be equipped with it is multiple.It, can be engaging in endless groove 25, interior by being equipped with multiple banking pins 45 Dispersion acts on the power of each banking pin 45 when all stage portions 13.

In addition, in above first embodiment, abjection guide portion is the slot tapered portion 25A of the endless groove 25 of piston rod 20, Storage guide portion is the taper surface 13A of the inner circumferential stage portion 13 of cylinder body 10.In contrast, can also be abjection guide portion and storage Guide portion is respectively formed in banking pin 45.In addition it is also possible to be that abjection guide portion is formed in banking pin 45, storage guide portion is formed In endless groove 25 and inner circumferential stage portion 13.Also, abjection guide portion and storage guide portion are not limited to taper surface, as long as with The movement of piston rod 20 and radially press banking pin 45 and be pushed out, such as can also be curved surface.Such as can also be, The end 45B of the end 45A of the radial outside of banking pin 45 and inside are respectively formed as semi-spherical shape, by each end 45A, The spherical surface of 45B is as abjection guide portion and storage guide portion.

According to the 1st above embodiment, effect as shown below is played.

In hydraulic cylinder 100, if buffering ring 41 is connected to abutting part 51, supply and discharge near stroke end when elongation acts Access 4 is blocked with being directly connected to for bar side room 1.From the state that buffering ring 41 and abutting part 51 abut, if piston rod 20 It is intended to further move to prolonging direction, then the relative movement of the piston rod 20 and buffering ring 41 that are limited by banking pin 45 is allowed. Thus, near the stroke end of elongation action, the working oil being discharged from bar side room 1 is imported into supply and discharge access by buffering access 42 4, play the pooling feature for making piston rod 20 slow down.Buffering ring 41 is held in piston rod 20 using banking pin 45 in this way, i.e., Make to be not provided with the spring for supporting buffering ring 41 in bar side room 1, can also play near the stroke end when elongation acts slow Rush function.Thus, it is possible to which hydraulic cylinder 100 is made to minimize.

In addition, in hydraulic cylinder 100, since the spring for supporting buffering ring 41 can not be equipped in bar side room 1, It prevents the action for leading to buffer part 40 because of losing for spring to become unstable situation, buffering work(can be played consistently Energy.

In addition, in hydraulic cylinder 100, due to not being to delimit buffering using the buffering bearing 340 into bearing receiving part 351 Access 341, therefore the buffer sealing part of the inside of bearing 340 need not be buffered, manufacturing cost can be reduced.It is further possible to Prevent extraordinary noise when buffering bearing 340 is detached from from bearing receiving part 351.

In addition, in hydraulic cylinder 100, it is slow with being delimited using buffering bearing 340 since bearing 340 need not be buffered The case where rushing access 341 is compared, and can increase the compression area for bearing compensator or trimmer pressure in cylinder cap 50 and piston 30.Therefore, energy Enough reduce compensator or trimmer pressure, so as to which cylinder body 10, cylinder cap 50, piston 30 are formed as relatively low intensity.Thus, it is possible to reduce Manufacturing cost.

(the 2nd embodiment)

Then, referring to Fig.1 3~Figure 17 illustrate the present invention the 2nd embodiment hydraulic cylinder 200.Hereinafter, with above-mentioned It is illustrated centered on the difference of 1 embodiment, pair structure mark identical with the hydraulic cylinder 100 of above first embodiment Identical reference numeral simultaneously omits the description.

In above first embodiment, limiting unit is through the inner peripheral surface of buffering ring 41 and the banking pin 45 of peripheral surface.

In contrast, the hydraulic cylinder 200 of the 2nd embodiment is to be respectively arranged on the periphery of buffering ring 141 and interior in limiting unit On this point of a pair of of limitation ring 145 in week, is different with the hydraulic cylinder 100 of above first embodiment.

As shown in figure 13, it is equipped in the peripheral surface of the buffering ring 141 of hydraulic cylinder 200 and is formed as cricoid circumferential groove 141A, It is equipped in the inner peripheral surface of the buffering ring 141 of hydraulic cylinder 200 and is formed as cricoid internal circle groove 141B.In addition, with above-mentioned 1st embodiment party Formula is similarly formed with buffering access 42 and radial slot 46 in buffering ring 141, and is formed with compared with buffering access 42 to work Make the smaller a plurality of primary path 142 of the resistance of the flowing application of oil.If buffering ring 141 is connected to abutting part 51, primary path 142 Abutting portion 51 blocks (referring to Fig.1 6).In addition, in Figure 13~Figure 17, single primary path 142 is only illustrated, remaining is omitted The diagram of primary path 142.As long as a plurality of primary path 142 is at least integrally formed as the flowing compared with buffering access 42 to working oil The resistance of application is smaller.

A pair of of limitation ring 145 has the peripheral ring 145A in the circumferential groove 141A of buffering ring 141 and is set to internal circle groove Interior chow ring 145B in 141B.

Peripheral ring 145A and interior chow ring 145B are respectively formed as the word that has joint gap (illustration omitted) and can scale Female C-shaped ring shape.Peripheral ring 145A and interior chow ring 145B is either the metal component such as snap ring, can also be resin system Component.In addition, in the present embodiment, as shown in figure 13, the section of peripheral ring 145A and interior chow ring 145B are rounded, but simultaneously It is without being limited thereto, it is possible to have other cross sectional shapes (such as quadrilateral shape shown in Figure 14).In addition it is also possible to such as Figure 15 institutes Show, rubber, spring etc. are equipped between peripheral ring 145A and circumferential groove 141A and between interior chow ring 145B and internal circle groove 141B and is applied Power component 145C, 145D exert a force to peripheral ring 145A to radial outside, and internal chow ring 145B exerts a force to radially inner side.

Peripheral ring 145A is contacted with the inner peripheral surface of cylinder body 10, and further expansion is limited by the inner peripheral surface of cylinder body 10.It changes Yan Zhi, peripheral ring 145A are from circumferential groove 141A to radial outside shape outstanding, by by cylinder body 10 in a free state Inner circumferential towards radially inner side press and shunk, to be accommodated in circumferential groove 141A.

Interior chow ring 145B is contacted with the peripheral surface of piston rod 20, and further receipts are limited by the peripheral surface of piston rod 20 Contracting.In other words, interior chow ring 145B is from internal circle groove 141B to radially inner side shape outstanding, by being lived in a free state The periphery of stopper rod 20 presses towards radial outside and is expanded, to be accommodated in internal circle groove 141B.

In hydraulic cylinder 200, peripheral ring 145A is contacted with the inner peripheral surface of cylinder body 10, and interior chow ring 145B is outer with piston rod 20 Circumferential surface contacts.Therefore, bar side room 1 is divided into the 1st bar side room 1A and the 2nd bar side room 1B using buffer part 140.1st bar side room 1A and the 2nd bar side room 1B are connected using the primary path 142 of buffering ring 141.

In the state that the sliding surface 11 of peripheral ring 145A and cylinder body 10 is opposite, the inner peripheral portion of interior chow ring 145B is accommodated in The endless groove 25 of piston rod 20, buffering ring 141 are held in piston rod 20.More particularly, to utilize the peripheral surface of piston rod 20 And the state expanded be accommodated in the interior chow ring 145B of internal circle groove 141B by the elastic force for the direction effect shunk to it limit from Endless groove 25 is deviate from.The state that buffering ring 141 is held in piston rod 20 is maintained as a result, limits buffering ring 141 and piston rod Relative movement in 20 axial direction.

As shown in figure 13, when elongation acts, in the state that the sliding surface 11 of buffer part 140 and cylinder body 10 is opposite, dimension The state that interior chow ring 145B is accommodated in endless groove 25 is held.Therefore, the state that buffering ring 141 is held in piston rod 20 is maintained. Thus, while 11 sliding contact of sliding surface of peripheral ring 145A and cylinder body 10, buffering ring 141 is stretched in the same direction with piston rod 20 1 Length direction moves.With the movement of piston rod 20, the working oil of the 1st bar side room 1A is imported directly supply and discharge access 4, and passes through confession Mouth 3 is arranged to be discharged.

If piston rod 20 is moved near extended travel end as shown in Figure 16, the peripheral ring 145A of buffer part 140 It is opposite with the big diametral plane 12 of cylinder body 10, and buffering ring 141 is connected to the abutting part 51 of cylinder cap 50.

The peripheral ring 145A that circumferential groove 141A is accommodated in the state of contraction utilizes elastic force when opposite with big diametral plane 12 It expands and is contacted with big diametral plane 12.If buffering ring 141 and the abutting of abutting part 51, supply and discharge access 4 and the 1st bar side room 1A's is direct Connection be blocked.Further, since 142 abutting portion 51 of primary path blocks, therefore the 2nd bar side room 1B and supply and discharge access 4 is logical The connection for crossing primary path 142 is also blocked.

From the state that buffering ring 141 and abutting part 51 abut, if piston rod 20 is further moved to prolonging direction, in Chow ring 145B is guided and pressed to radial outside by the slot tapered portion 25A of endless groove 25.As a result, as shown in figure 17, interior chow ring 145B overcomes to the elastic force that shrinkage direction acts on and expands and deviate from from endless groove 25.Thus, piston rod 20 is to buffering ring 141 Holding be released from, relative movement of the piston rod 20 relative to buffering ring 141 to prolonging direction is allowed.

If piston rod 20 is further moved to prolonging direction, the working oil of the 2nd bar side room 1B is by buffering 42 quilt of access It imports supply and discharge access 4 and supply and discharge mouth 3 and is discharged.Thus, the resistance for having and being applied by buffering access 42 to the effect of the 2nd bar side room 1 Corresponding compensator or trimmer pressure.In this way, having played the pooling feature near the extended travel end of piston rod 20.

When carrying out contractive action from extended travel end, utilizes in the same manner as above first embodiment and led from supply and discharge access 4 The working oil entered makes buffering ring 141 and 20 1 shrinkage direction in the same direction of piston rod move and peripheral ring 145A and inner circumferential stage portion 13 The corresponding distance of axial gap.Buffering ring 141 and abutting part 51 detach as a result, and supply and discharge access 4 and the 1st bar side room 1A directly connect It is logical.

If buffering ring 141 and piston rod 20 are mobile between peripheral ring 145A and the axial direction of inner circumferential stage portion 13 to shrinkage direction The corresponding distance of gap, then peripheral ring 145A and inner circumferential stage portion 13 abut.It is acted on to dimension at this point, peripheral ring 145A is utilized The elastic force state that maintains it locking with inner circumferential stage portion 13, inner circumferential stage portion will not be crossed towards the sliding surface 11 of cylinder body 10 13.Therefore, buffering ring 141 by peripheral ring 145A engaging in inner circumferential stage portion 13.Thus, the work imported from supply and discharge access 4 The pressure of oil is imported into radial slot 46 by the 1st bar side room 1A, primary path 142 and the 2nd bar side room 1B, acts on piston 30 End face.Buffering ring 141 and piston 30 detach as a result, and piston rod 20 is relatively moved relative to buffering ring 141 to shrinkage direction.

If piston rod 20 be moved to shrinkage direction interior chow ring 145B and piston rod 20 endless groove 25 it is opposite until, in Chow ring 145B is shunk using elastic force and is accommodated in endless groove 25.In addition, buffering ring 141 is connected to the step of piston rod 20 Portion 23.Therewith, if piston rod 20 is further moved to shrinkage direction, buffering ring 141 is also intended to a shrinkage direction movement in the same direction.Cause This, peripheral ring 145A is overcome by the taper surface 13A of inner circumferential stage portion 13 on the inside of the elastic force geocentric vertical acted on to dimension It presses and shrinks.The locking of inner circumferential stage portion 13 of peripheral ring 145A and cylinder body 10 are released from as a result, buffering ring 141 and piston 20 1 shrinkage direction in the same direction of bar moves.

According to the 2nd above embodiment, effect identical with above first embodiment is played.

In addition, in hydraulic cylinder 200, since the inner circumferential of interior chow ring 145B is integrally accommodated in endless groove 25, interior chow ring 145B is contacted with the contact of endless groove 25 as line.Therefore, with the end 45B of the radially inner side of banking pin 45 and endless groove 25 with The above first embodiment that the mode of point contact contacts is compared, and the power for making interior chow ring 145B deviate from from endless groove 25 can be disperseed, Durability can be made to improve.

In addition, in above-mentioned 2nd embodiment, limiting unit is a pair of of limitation ring (peripheral ring 145A and interior chow ring 145B), But it can also replace, using by force application component 145C, 145D (referring to Fig.1 5) is respectively to outside and radially radially Inside force one or more spheres (steel ball etc.) be used as limiting unit.

(the 3rd embodiment)

Then, referring to Fig.1 8~Figure 21 illustrate the present invention the 3rd embodiment hydraulic cylinder 300.Hereinafter, with above-mentioned It is illustrated centered on the difference of 1 embodiment, pair structure mark identical with the hydraulic cylinder 100 of above first embodiment Identical reference numeral simultaneously omits the description.

In above first embodiment, limiting unit is through the inner peripheral surface of buffering ring 41 and the banking pin 45 of peripheral surface.

In contrast, the hydraulic cylinder 300 of the 3rd embodiment in limiting unit is disposed adjacently and has with buffering ring 241 Joint gap 245A and single hydraulic pressure on this point of scaling ring 245 with above first embodiment for being formed to scaling Cylinder 100 is different.

As shown in figure 18, the buffering ring 241 of hydraulic cylinder 300 by the stage portion 23 of piston rod 20 and scales ring 245 clampingly Setting.It is formed with buffering access 242 and radial slot 46 in buffering ring 241 in the same manner as above first embodiment, and slow at this The radially inner side for rushing the end face opposite with scaling ring 245 of ring 241 is formed with cricoid central indentation 243.Buffer access 242 with The space of the inside of central indentation 243 is communicatively formed.Central indentation 243 is opened on the opposite with scaling ring 245 of buffering ring 241 End face, and be opened on the inner peripheral surface of buffering ring 241.In addition, being formed in the orifice plug that can be loaded and unloaded for buffering ring 241 slow In the case of rushing access 242, scaling ring 245 adjacent in the axial direction is as preventing orifice plug to be detached from from buffering ring 241 Pressing member functions.

As shown in figure 19, scaling ring 245 has joint gap 245A and is formed to the letter C shape ring-type of scaling.Contracting Ring 245 is put under its state opposite with the sliding surface 11 of cylinder body 10 (state shown in figure 18), as shown in figure 19, inner peripheral portion Divide and be accommodated in endless groove 25, and gap is formed between sliding surface 11 at it.

As shown in Figure 18 and Figure 19, it is formed in scaling ring 245 in the end face opposite with buffering ring 241 of scaling ring 245 The central stepped portion 246 of the inside of central indentation 243 is inserted into the state of being contacted with buffering ring 241.

The outer diameter in central stepped portion 246 is formed as being less than buffering ring in the state of scaling ring 245 and being accommodated in endless groove 25 The internal diameter of 241 central indentation 243.Thus, in the state that scaling ring 245 is accommodated in endless groove 25, in buffering ring 241 It entreats and is equipped with gap between recess portion 243 and the central stepped portion 246 for scaling ring 245 radially.In addition, in buffering ring 241 and contracting In the state of putting the contact of ring 245, central stepped portion 246 does not contact with central indentation 243 and forms gap in the axial direction.Thus, Buffer access 242 by radial clearance and axial gap between central stepped portion 246 and central indentation 243 with scaling ring 245 joint gap 245A (referring to Fig.1 9) connections.

If scaling ring 245 to expand, central stepped portion 246 is contacted with the central indentation 243 of buffering ring 241.In this way Scaling ring 245 central stepped portion 246 contacted with the central indentation 243 of buffering ring 241, it is therefore prevented that scaling ring 245 center and The center of piston rod 20 is staggered.That is, the central indentation 243 of buffering ring 241 prevents the scaling ring generated with expansion 245 core offset, plays the aligning function for making the sliding of scaling ring 245 and buffering ring 241 stablize.

Scaling ring 245 is accommodated in the endless groove 25 of piston rod 20 in the state that it is opposite with the sliding surface 11 of cylinder body 10, And engaging in buffering ring 241 in a manner of buffering ring 241 is clamped between the stage portion 23 of piston rod 20 at it.It buffers as a result, Ring 241 is held in piston rod 20.Under the state (state shown in figure 18) that the inner peripheral surface of scaling ring 245 is contacted with endless groove 25 Outer diameter is less than the internal diameter of sliding surface 11.In addition, under the state (state shown in Figure 20) that the slave endless groove 25 of scaling ring 245 is deviate from Outer diameter be more than sliding surface 11 internal diameter and less than big diametral plane 12 internal diameter.It is connect with endless groove 25 in the inner peripheral surface of scaling ring 245 In the state of touching, gap is formed between the peripheral surface and the sliding surface 11 of cylinder body 10 of scaling ring 245.

As shown in figure 18, in the state that the sliding surface 11 for scaling ring 245 and cylinder body 10 is opposite, sliding surface 11 is utilized to limit The expansion of scaling ring 245 limits scaling ring 245 and deviates from from endless groove 25.

In the state that the big diametral plane 12 for scaling ring 245 and cylinder body 10 is opposite, allow to scale ring 245 using big diametral plane 12 Expansion becomes the state that scaling ring 245 can be deviate from from endless groove 25.Thus, as shown in figure 20, expanded by scaling ring 245 And deviate from from endless groove 25, piston rod 20 is released from the holding of buffering ring 241.

When elongation acts, as shown in figure 18, in the state that the sliding surface 11 of buffer part 240 and cylinder body 10 is opposite, profit The expansion of the scaling ring 245 of buffer part 240 is limited with sliding surface 11.Therefore, it maintains scaling ring 245 and is accommodated in endless groove 25 State.Thus, buffering ring 241 maintains the state for being held in piston rod 20, and is moved with 20 1 prolonging direction in the same direction of piston rod. With the movement of piston rod 20, the working oil of bar side room 1 is imported directly supply and discharge access 4, and is discharged by supply and discharge mouth 3.

If piston rod 20 is moved near extended travel end, the big diametral plane of the scaling ring 245 and cylinder body 10 of buffer part 40 12 is opposite, and buffering ring 241 is connected to the abutting part 51 of cylinder cap 50.

When buffering ring 241 and abutting part 51 abut, supply and discharge access 4 is blocked with being directly connected to for bar side room 1.

From the state that buffering ring 241 and abutting part 51 abut, if piston rod 20 is further moved to prolonging direction, such as Shown in Figure 20, scaling ring 245 is pressed by the slot tapered portion 25A guiding of endless groove 25 and to radial outside.Ring 245 is scaled as a result, It expands and deviates from from endless groove 25.Thus, piston rod 20 is released from the holding of buffering ring 241, and piston rod 20 is relative to buffering Relative movement of the ring 241 to prolonging direction is allowed.

If piston rod 20 is further moved to prolonging direction, the working oil of bar side room 1 is by scaling between the healing up of ring 245 Gap 245A, scale ring 245 central stepped portion 246 and the central indentation 243 of buffering ring 241 between radial clearance and axial direction between Gap is imported into buffering access 242.The working oil of bar side room 1 is imported into supply and discharge access 4 and supply and discharge mouth 3 simultaneously by buffering access 242 It is discharged from bar side room 1.Thus, there is compensator or trimmer pressure corresponding with the resistance applied by buffering access 242 to the effect of bar side room 1.This Sample has played the cushioning effect near the extended travel end of piston rod 20.

When carrying out contractive action from extended travel end, utilizes in the same manner as above first embodiment and led from supply and discharge access 4 The working oil entered makes buffering ring 241 and 20 1 shrinkage direction in the same direction of piston rod move and scaling ring 245 and inner circumferential stage portion 13 The corresponding distance of axial gap.As a result, as shown in figure 21, buffering ring 241 and abutting part 51 detach, supply and discharge access 4 and the 1st bar side Room 1A is directly connected to.

If buffering ring 241 and piston rod 20 are mobile between scaling ring 245 and the axial direction of inner circumferential stage portion 13 to shrinkage direction The corresponding distance of gap, then scale ring 245 and inner circumferential stage portion 13 abuts.At this point, inner peripheral surface and piston rod due to scaling ring 245 20 small diameter portion 22 is opposite, therefore the scaling ring 245 cannot be shunk (with reference to Figure 20).Since scaling ring 245 will not be towards cylinder body 10 sliding surface 11 crosses inner circumferential stage portion 13, thus buffering ring 241 by scaling ring 245 engaging in inner circumferential stage portion 13.

Thus, the pressure of the working oil imported from supply and discharge access 4 passes through bar side room 1 and scales the joint gap of ring 245 245A is imported into radial slot 46, and acts on the end face of piston 30.Buffering ring 241 and piston 30 detach as a result, 20 phase of piston rod Buffering ring 241 is relatively moved to shrinkage direction.

If piston rod 20 is moved to the endless groove 25 for scaling ring 245 and piston rod 20 to shrinkage direction with respect to until, contract Ring 245 is put to be pressed to radially inner side by the taper surface 13A of inner circumferential stage portion 13, and shunk using the elastic force of itself and It is accommodated in endless groove 25.The locking of inner circumferential stage portion 13 of scaling ring 245 and cylinder body 10 is released from as a result, and scaling ring 245 is again It is accommodated in the endless groove 25 of piston rod 20.The buffering ring 241 for being held in piston rod 20 again in this way is received in the same direction with piston rod 20 1 It moves in contracting direction.

According to the 3rd above embodiment, effect identical with above first embodiment is played.

In addition, in the same manner as above-mentioned 2nd embodiment, in hydraulic cylinder 300, since the inner circumferential of scaling ring 245 is integrally received It is contained in endless groove 25, therefore compared with above first embodiment, the power for making scaling ring 245 deviate from from endless groove 25 can be disperseed, Durability can be made to improve.

Hereinafter, concluding the structure, function and effect for illustrating embodiments of the present invention.

Hydraulic cylinder 100,200,300 includes：Cylinder body 10；Piston rod 20 is inserted into cylinder body 10；Piston 30, with piston rod 20 top connection, and bar side room 1 and bottom side room 2 will be divided into cylinder body 10；Buffer part 40,140,240 is set to piston rod 20 periphery, and piston rod 20 is made to slow down near the stroke end when elongation acts；Supply and discharge access 4 is connected to bar side room 1, The working fluid for feeding to the working fluid of the supply of bar side room 1 and being discharged from bar side room 1 passes through；And abutting part 51, it is set to cylinder Body 10, and abutted for buffer part 40 near the stroke end when elongation acts, buffer part 40,140,240 has：Buffering ring 41, 141,241, abutting part 51 is connected near the stroke end when elongation acts；And limiting unit (banking pin 45, a pair of of limitation Ring 145, scaling ring 245), being accommodated in buffering ring is limited in the state of endless groove 25 of the peripheral surface of piston rod 20 formation 41,141,241 relative movement relative to piston rod 20, with buffering ring 41 near the stroke end when elongation acts, 141, 241 and abutting part 51 abut, supply and discharge access 4 and bar side room 1 directly be connected tos by the blocking of buffering ring 41,141,241, and are limited Portion processed (banking pin 45, a pair of of limitation ring 145, scaling ring 245) from the abjection of endless groove 25 and buffering ring 41,141,241 relative to The relative movement of piston rod 20 is allowed, the working oil of bar side room 1 by by working oil apply the buffering access of resistance 42, it 242 is discharged from supply and discharge access 4.

In addition, in hydraulic cylinder 100,200,300, the inner peripheral surface of cylinder body 10 has 11 He of sliding surface slided for piston 30 The big diametral plane 12 that internal diameter forms larger compared with sliding surface 11, for limiting unit (banking pin 45, a pair of of limitation ring 145, contracting Put ring 245), it is limited by its abutting with sliding surface 11 and is deviate from from endless groove 25, by making itself and 12 phase of big diametral plane Pair and allowed its from endless groove 25 deviate from.

In this configuration, if buffer part 40,140,240 is connected to abutting part 51 near stroke end when elongation acts, Then supply and discharge access 4 is blocked with being directly connected to for bar side room 1.The state abutted from buffer part 40,140,240 and abutting part 51 It rises, if piston rod 20 is intended to further move to prolonging direction, by limiting unit (banking pin 45, a pair of of limitation ring 145, scaling ring 245) relative movement of the piston rod 20 and buffering ring 41,141,241 limited is allowed.Thus, in the stroke end of elongation action Near, the working oil being discharged from bar side room 1 is imported into supply and discharge access 4 by buffering access 42,242, and having played makes piston rod 20 The pooling feature of deceleration.Limiting unit (banking pin 45, a pair of of limitation ring 145, scaling ring 245) is utilized to limit buffering in this way Relative movement of the ring 41,141,241 relative to piston rod 20, though bar side room 1 be not provided with for support buffering ring 41,141, 241 spring has also played pooling feature near the stroke end when elongation acts.Thus, it is possible to make fluid-pressure cylinder 100, 200,300 miniaturization.

In addition, in hydraulic cylinder 100,200,300, at limiting unit (banking pin 45, a pair of of limitation ring 145, scaling ring 245) It is formed with slot tapered portion 25A at least one of endless groove 25, the shape abutted from buffering ring 41,141,241 and abutting part 51 State rises, and as piston rod 20 is moved to prolonging direction, by limiting unit, (banking pin 45, contracts at interior chow ring 145B the slot tapered portion 25A Put ring 245) it is pressed to radial outside and it is made to deviate from from endless groove 25.

Using the structure, from the state that buffering ring 41,141,241 and abutting part 51 abut, as piston rod 20 is to stretching Length direction moves, and limiting unit (banking pin 45, interior chow ring 145B, scaling ring 245) can reliably be made to deviate from from endless groove 25.

In addition, in hydraulic cylinder 100,200,300, the inner peripheral surface of cylinder body 10, which also has, is formed in sliding surface 11 and big diametral plane Inner circumferential stage portion 13 between 12, in limiting unit (banking pin 45, peripheral ring 145A, scaling ring 245) and inner circumferential stage portion 13 At least one be formed with storage guide portion, from the state that buffering ring 41,141,241 and abutting part 51 abut, with piston Bar 20 is moved to shrinkage direction, and the storage guide portion is by limiting unit (banking pin 45, peripheral ring 145A, scaling ring 245) to radial direction Inside presses and it is made to be accommodated in endless groove 25.

Using the structure, from the state that buffering ring 41,141,241 and abutting part 51 abut, as piston rod 20 is to receipts Contracting direction is moved, and limiting unit (banking pin 45, peripheral ring 145A, scaling ring 245) can reliably be made to be accommodated in endless groove 25, and Piston rod 20 is set to be moved to shrinkage direction.

In addition, in hydraulic cylinder 100,200,300, in the state that buffering ring 41 and abutting part 51 abut, in limiting unit (banking pin 45, peripheral ring 145A, scaling ring 245) is formed with the gap in axial direction between inner circumferential stage portion 13.

In this configuration, when carrying out contractive action from extended travel end, supply and discharge access 4 is promptly connected to bar side room 1. Thus, it is possible to ensure response when contractive action starts.

In addition, in hydraulic cylinder 100,200,300, can also be that buffering access 42,242 is formed in orifice plug, the throttling Plug is detachably set to buffering ring 41,141,241.

The adjustment of cushion performance can easily be done by replacing orifice plug using the structure.

In addition, in hydraulic cylinder 100, limiting unit is banking pin 45, the banking pin 45 through buffering ring 41 peripheral surface and Inner peripheral surface, and be set as moving freely radially.

In addition, in hydraulic cylinder 200, limiting unit is a pair of of limitation ring 145 (peripheral ring 145A and interior chow ring 145B), this one It is respectively arranged on periphery and the inner circumferential of buffering ring 141 to limitation ring 145, there is joint gap and is formed to scale.

In addition, in hydraulic cylinder 300, limiting unit is scaling ring 245, the scaling ring 245 in the axial direction with 241 phase of buffering ring It is arranged adjacently, there is joint gap 245A and is formed to scale.

In addition, in hydraulic cylinder 300, buffering ring 241, which has, to be formed in the inside of the end face opposite with scaling ring 245 It entreats recess portion 243, scaling ring 245 that there is the central stepped portion 246 for being inserted into central indentation 243, piston rod is accommodated in scaling ring 245 In the state of 20 endless groove 25, it is formed with radial clearance between central indentation 243 and central stepped portion 246, in scaling ring 245 expand in the state of the abjection of endless groove 25, and central stepped portion 246 is contacted with central indentation 243.

In this configuration, by making the central indentation 243 of buffering ring 241 and the central stepped portion 246 of scaling ring 245 connect It touches, aligning can be carried out to scaling ring 245 and makes its expansion.Thus, it is possible to keep the sliding of buffering ring 41 and scaling ring 245 steady It is fixed.

Embodiments of the present invention are this concludes the description of, but the above embodiment shows only the application examples of the present invention A part, purport do not lie in the concrete structure that protection scope of the present invention is defined in the above embodiment.

The Japanese Patent Application 2016- that this application claims filed an application to Japanese Patent Office based on March 31st, 2016 72428 priority, by referring to all the contents of the application are incorporated into this specification.

Claims (10)

1. a kind of fluid-pressure cylinder, wherein

The fluid-pressure cylinder includes：

Cylinder body；

Piston rod is inserted into the cylinder body；

Piston links with the top of the piston rod, and will be divided into bar side room and bottom side room in the cylinder body；

Buffer part, is set to the periphery of the piston rod, and the piston rod is made to slow down near the stroke end when elongation acts；

Supply and discharge access is connected to the bar side room, is fed to the working fluid of the bar side room supply and is arranged from the bar side room The working fluid gone out passes through；And

Abutting part is set to the cylinder body, and is abutted for the buffer part near the stroke end when elongation acts,

The buffer part has：Buffering ring is connected to the abutting part near the stroke end when elongation acts；And limitation Portion limits the buffering ring relative to the work being accommodated in the state of the recess portion of the peripheral surface of piston rod formation The relative movement of stopper rod,

As the buffering ring near the stroke end when elongation acts and the abutting part abut, the supply and discharge access and described The direct connection of bar side room is blocked by the buffering ring, and the limiting unit is deviate from and the buffering ring phase from the recess portion The relative movement of the piston rod is allowed, the working fluid of the bar side room by by working fluid apply resistance The buffering access of power is discharged from the supply and discharge access.

2. fluid-pressure cylinder according to claim 1, wherein

The inner peripheral surface of the cylinder body have for the piston sliding sliding surface and compared with the sliding surface internal diameter formed compared with Big big diametral plane,

For the limiting unit, limits it using its abutting with the sliding surface and deviate from from the recess portion, by making it It is opposite with the big diametral plane and it has been allowed to deviate from from the recess portion.

3. fluid-pressure cylinder according to claim 1, wherein

It is formed with abjection guide portion at least one of the limiting unit and the recess portion, from the buffering ring and the abutting The state that portion abuts rises, and as the piston rod is moved to prolonging direction, the abjection guide portion is outside to diameter by the limiting unit It releases and it is made to deviate from from the recess portion in side.

4. fluid-pressure cylinder according to claim 2, wherein

The inner peripheral surface of the cylinder body also has the inner circumferential stage portion being formed between the sliding surface and the big diametral plane,

It is formed with storage guide portion at least one of the limiting unit and the inner circumferential stage portion, from the buffering ring and institute State abutting part abutting state rise, with the piston rod to shrinkage direction move, the storage guide portion by the limiting unit to Radially inner side presses and it is made to be accommodated in the recess portion.

5. fluid-pressure cylinder according to claim 4, wherein

In the state that the buffering ring and the abutting part abut, formed between the limiting unit and the inner circumferential stage portion There is the gap in axial direction.

6. fluid-pressure cylinder according to claim 1, wherein

The buffering access is formed in orifice plug, which is detachably set to the buffering ring.

7. fluid-pressure cylinder according to claim 1, wherein

The limiting unit is banking pin, which runs through the peripheral surface and inner peripheral surface of the buffering ring, and is set as in radial direction On move freely.

8. fluid-pressure cylinder according to claim 1, wherein

The limiting unit is a pair of of limitation ring, which is respectively arranged on periphery and the inner circumferential of the buffering ring, and is formed For that can scale.

9. fluid-pressure cylinder according to claim 1, wherein

The limiting unit is scaling ring, which is disposed adjacently with the buffering ring in the axial direction, have joint gap and It is formed to scale.

10. fluid-pressure cylinder according to claim 9, wherein

The buffering ring has the central indentation for the inside for being formed in the end face opposite with the scaling ring,

The scaling ring has the central stepped portion for being inserted into the central indentation,

In the state that the scaling ring is accommodated in the recess portion of the piston rod, in the central indentation and the central station Rank is formed with radial clearance between portion,

In the state that the scaling ring extension is deviate from from the recess portion, the central stepped portion connects with the central indentation It touches.