CN220081833U

CN220081833U - Hydraulic cylinder

Info

Publication number: CN220081833U
Application number: CN202321414368.3U
Authority: CN
Inventors: 刘国良; 陈兵
Original assignee: Hunan Sinoboom Intelligent Equipment Co Ltd
Current assignee: Hunan Sinoboom Intelligent Equipment Co Ltd
Priority date: 2023-06-05
Filing date: 2023-06-05
Publication date: 2023-11-24
Anticipated expiration: 2033-06-05

Abstract

The utility model discloses a hydraulic cylinder, comprising: the cylinder body assembly is provided with a rodless cavity oil port at one end and a guide sleeve at the other end; the piston rod is movably penetrated through the guide sleeve, the extending end of the piston rod extends into the cylinder body assembly, the extending end of the piston rod is fixedly connected with the supporting piece, the side wall of the piston rod is provided with a supporting part which is spaced from the supporting piece, and the supporting part is positioned at one side of the supporting piece close to the guide sleeve; the piston assembly is located the cylinder body assembly, the piston assembly is including the cover locate outside the piston rod and can follow the axial displacement's of piston rod first piston, and the cover locate outside the piston rod and can follow the axial displacement's of piston rod second piston, first piston and second piston are all limited between supporting portion and supporting the piece, and first piston is located the second piston and is close to one side of supporting the portion of holding, the inside of cylinder body assembly still is equipped with spacing portion, spacing portion is located one side that the second piston kept away from first piston, be provided with the elastic compression spare between first piston and the second piston.

Description

Hydraulic cylinder

Technical Field

The utility model relates to the technical field of hydraulic equipment, in particular to a hydraulic cylinder.

Background

In the field of hydraulic equipment, it is generally prescribed that when the operating speed of the hydraulic cylinder is greater than 0.2m/s, a buffer structure must be provided to reduce the impact on the bottom and head of the hydraulic cylinder when the piston is operating to both ends of the hydraulic cylinder. Sometimes, in order to ensure the operation experience of equipment, particularly in the field of overhead working trucks, the hydraulic cylinders used by the equipment are also provided with corresponding buffer structures.

At present, two methods for realizing buffering of a hydraulic cylinder are basically available: the hydraulic cylinder is controlled outside, stroke induction of the hydraulic cylinder is increased, and the running speed of the hydraulic cylinder is reduced by controlling the flow of hydraulic oil at a terminal, so that the hydraulic cylinder has a complex structure and high cost; a buffer structure is designed in the hydraulic cylinder, and the hydraulic cylinder is simple and compact in structure and wide in application.

In the existing technology of arranging a buffer structure inside a hydraulic cylinder, the hydraulic cylinder is usually throttled through a clearance throttling function, namely through clearance fit between a buffer plunger and a buffer hole, so that enough internal pressure is formed when the hydraulic cylinder moves to the vicinity of two end points, and the running speed of the hydraulic cylinder is reduced, so that the impact is reduced. However, this buffer structure has the following disadvantages: the buffer plunger and the buffer hole are required to have extremely high coaxiality and extremely small fit clearance, the buffer plunger is often arranged at two ends of the piston, the buffer hole is arranged on the cylinder base and the guide sleeve, the cylinder base and the cylinder barrel are often welded, the guide sleeve and the cylinder barrel are in threaded connection, the coaxiality requirements of all parts of the piston, the guide sleeve, the cylinder barrel and the cylinder base are extremely high, the requirement on processing precision is high, and in addition, the welding deformation of the cylinder base and the cylinder barrel is easy to destroy the precise fit.

Disclosure of Invention

The present utility model aims to solve at least one of the technical problems existing in the prior art. Therefore, the hydraulic cylinder provided by the utility model can reduce the machining precision requirement of parts, thereby reducing the cost.

According to some embodiments of the utility model, a hydraulic cylinder includes: the cylinder body assembly is provided with a rodless cavity oil port at one end and a guide sleeve at the other end; the piston rod is movably arranged in the guide sleeve in a penetrating mode, the extending end of the piston rod extends into the cylinder body assembly, the extending end of the piston rod is fixedly connected with a supporting piece, the side wall of the piston rod is provided with a supporting portion which is spaced from the supporting piece, and the supporting portion is located on one side, close to the guide sleeve, of the supporting piece; the piston assembly is positioned in the cylinder assembly, the piston assembly comprises a first piston sleeved outside the piston rod and capable of moving along the axial direction of the piston rod, and a second piston sleeved outside the piston rod and capable of moving along the axial direction of the piston rod, the first piston and the second piston are both limited between the supporting part and the supporting part, the first piston is positioned on one side, close to the supporting part, of the second piston, a limiting part is further arranged in the cylinder assembly, the limiting part is positioned on one side, far away from the first piston, of the second piston, and an elastic compression part is arranged between the first piston and the second piston;

a buffer cavity is formed between the first piston and the second piston; the first piston is provided with a first oil passing channel; the second piston is provided with a second oil passing channel; one end of the first oil passing channel is communicated with a rod cavity of the cylinder assembly, the other end of the first oil passing channel is communicated with one end of the second oil passing channel, and the other end of the second oil passing channel is communicated with a rodless cavity of the cylinder assembly; the first piston is further provided with a third oil passing channel communicated with the buffer cavity, the third oil passing channel is sealed by the abutting part when the first piston abuts against the abutting part, and the third oil passing channel is communicated with a rod cavity of the cylinder assembly when the first piston is separated from the abutting part;

the first piston and the second piston can be mutually close to or far away from each other, and before the first piston and the second piston are not abutted tightly, the other end of the first oil passing channel and one end of the second oil passing channel are communicated with the buffer cavity.

The hydraulic cylinder provided by the embodiment of the utility model has at least the following beneficial effects:

the use principle of the hydraulic cylinder of the utility model is as follows:

when the hydraulic oil advances oil from the rodless cavity hydraulic fluid port, the hydraulic oil passes through the second oil passage of second piston and the first oil passage of first piston and reaches the rodless cavity, and at this moment, hydraulic oil also can get into the cushion chamber, and under the effect of the pressure of elastic compression piece and hydraulic oil, first piston can keep to support with the portion of supporting of piston rod, and the second piston can keep to support with the piece of supporting, and at this moment, the assembly that first piston and second piston formed and piston rod can keep away from the rodless cavity hydraulic fluid port under the promotion of hydraulic oil.

When the first piston and the guide sleeve are propped against each other, oil is continuously fed into the rodless cavity oil port, the piston rod and the propping piece continuously drive the second piston to be away from the rodless cavity oil port, the first piston cannot continuously be away from the rodless cavity oil port due to the blocking of the guide sleeve, the second piston of the first piston moves relatively, the first piston and the second piston form a nested relation, when the piston rod and the propping piece continuously drive the second piston to be away from the rodless cavity oil port, hydraulic oil in the buffer cavity slowly flows out through a fit gap between the first piston and the second piston, the running speed of the piston rod is forced to be reduced until the second piston and the first piston are propped against each other, the piston rod runs to an upper end point, and rising buffering is completed.

When the hydraulic oil pressure in the hydraulic cylinder drops and is insufficient to balance the load carried by the piston rod, the piston rod starts to move towards the rodless cavity oil port, the second piston is separated from the guide sleeve, hydraulic oil enters the buffer cavity through the third oil passing channel, the first piston moves upwards relative to the second piston under the action of the elastic compression piece until the first piston returns to an initial state, when the combined body continues to drop until the first piston abuts against the abutting part, the second piston abuts against the limiting part, the limiting part can limit the second piston and cannot continue to drop, the first piston and the second piston do relative movement, the first piston and the second piston form a nested relation, when the piston rod together with the abutting part continues to drive the first piston to drop, hydraulic oil in the buffer cavity can slowly flow out through a fit gap between the first piston and the second piston and a fit gap between the second piston, the piston rod is forced to drop the running speed until the first piston abuts against the second piston, the piston rod runs to a lower end point, and the descending buffering is completed.

The hydraulic cylinder is compact in structure, only the mutual matching precision of the first piston and the second piston and the mutual matching precision of the second piston and the piston rod are required to be ensured, the machining precision is easy to control, and the conventional precise matching of the buffer plunger and the welding type base is omitted, so that the aim of reducing the cost is fulfilled. In addition, the first piston is in a floating state in the cylinder body assembly in the radial direction, and when the first piston and the second piston perform relative movement, the first piston and the second piston can be automatically centered, so that the mutual friction between the first piston and the second piston is reduced, the good buffering effect is ensured, and the service life is prolonged.

According to some embodiments of the utility model, a first chamber is provided on a side of the second piston adjacent to the first piston, and the first piston is capable of penetrating into the first chamber.

According to some embodiments of the utility model, the first piston comprises a sealing part in sealing fit with the inner side wall of the cylinder assembly and a penetrating part connected with the sealing part, the penetrating part can penetrate into the first cavity, the outer side wall of the penetrating part is spaced from the inner side wall of the cylinder assembly, the outer side wall of the penetrating part is provided with an oil passing groove, the oil passing groove is communicated with the other end of the first oil passing channel, and the oil passing groove is communicated with one end of the second oil passing channel.

According to some embodiments of the utility model, the first oil passage is opened at the sealing portion, and the other end of the first oil passage is communicated with a gap between an outer side wall of the penetrating portion and an inner side wall of the cylinder assembly.

According to some embodiments of the utility model, one end of the second oil passage communicates with a gap between an outer sidewall of the penetration and an inner sidewall of the cylinder assembly.

According to some embodiments of the utility model, a second chamber is arranged on one side of the penetrating part, which is close to the second piston, the second chamber is communicated with the first chamber, and the third oil passing channel is communicated with the second chamber.

According to some embodiments of the utility model, an outer sidewall of the penetration portion is in guiding engagement with a sidewall of the first chamber.

According to some embodiments of the utility model, the elastic compression member is a spring, and the spring is sleeved outside the piston rod.

According to some embodiments of the utility model, the cylinder assembly comprises a cylinder and a base arranged at one end of the cylinder, and the guide sleeve is arranged inside the other end of the cylinder.

According to some embodiments of the utility model, one end of the third oil passage is communicated with the buffer cavity, the other end of the third oil passage is opposite to the abutting part, when the first piston abuts against the abutting part, the other end of the third oil passage is sealed by the abutting part, and when the first piston is separated from the abutting part, the other end of the third oil passage is communicated with the rod cavity of the cylinder assembly.

Additional aspects and advantages of the utility model will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the utility model.

Drawings

The utility model is further described with reference to the accompanying drawings and examples, in which:

FIG. 1 is a schematic diagram of a hydraulic cylinder according to an embodiment of the present utility model;

FIG. 2 is a schematic diagram of a hydraulic cylinder according to an embodiment of the present utility model;

FIG. 3 is a schematic diagram of a hydraulic cylinder according to an embodiment of the present utility model;

FIG. 4 is a schematic diagram of a hydraulic cylinder according to an embodiment of the present utility model;

fig. 5 is a schematic diagram of a hydraulic cylinder according to an embodiment of the present utility model.

Reference numerals:

100. a cylinder assembly; 101. an oil port of the rodless cavity; 102. a rodless cavity; 103. a rod cavity is arranged; 104. a limit part; 110. a cylinder; 120. a base;

200. a guide sleeve;

300. a piston rod; 310. a holding member; 320. a holding portion; 330. a locking member;

400. a piston assembly; 401. a buffer chamber; 410. a first piston; 410a, a sealing part; 410b, a penetrating portion; 411. a first oil passage; 412. a third oil passage; 413. passing through an oil groove; 414. a second chamber; 420. a second piston; 421. a second oil passage; 422. a first chamber;

500. an elastic compression member.

Detailed Description

Embodiments of the present utility model are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the utility model.

In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present utility model and to simplify the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present utility model. Furthermore, features defining "first", "second" may include one or more such features, either explicitly or implicitly. In the description of the present utility model, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the description of the present utility model, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

As shown in fig. 1, a hydraulic cylinder according to an embodiment of the present utility model includes a cylinder assembly 100, a guide sleeve 200, a piston rod 300, and a piston assembly 400.

One end of the cylinder assembly 100 is provided with a rodless cavity oil port 101, and a guide sleeve 200 is arranged in the other end of the cylinder assembly 100.

Specifically, the cylinder assembly 100 is of a hollow structure, the cylinder assembly 100 has two opposite ends, one end of the cylinder assembly 100 is provided with a rodless cavity oil port 101 communicated with the interior of the cylinder assembly 100, and the interior of the other end of the cylinder assembly 100 is fixedly provided with a guide sleeve 200.

The cylinder assembly 100 includes a cylinder 110 and a base 120 disposed at one end of the cylinder 110, and a rodless cavity oil port 101 is formed in the base 120.

It should be noted that, the base 120 and one end of the cylinder 110 are fixed by welding; the guide sleeve 200 is fixed with the cylinder 110 in a threaded connection manner, that is, a first thread is arranged on the outer side wall of the guide sleeve 200, a second thread is arranged in the other end of the cylinder 110, and the guide sleeve 200 penetrates through the other end of the cylinder 110 and enables the first thread to be connected with the second thread.

Of course, in other embodiments, the base 120 and the cylinder 110 may be fixedly connected in other manners, and the guide sleeve 200 may be fixed in the cylinder 110 in other manners.

The piston rod 300 movably penetrates through the guide sleeve 200, the extending end of the piston rod 300 extends into the cylinder assembly 100, the extending end of the piston rod 300 is fixedly connected with the supporting piece 310, the side wall of the piston rod 300 is provided with a supporting portion 320 which is spaced from the supporting piece 310, and the supporting portion 320 is located on one side of the supporting piece 310 close to the guide sleeve 200.

Specifically, the piston rod 300 is inserted through the guide sleeve 200 and is movable in the axial direction of the guide sleeve 200, wherein the guide sleeve 200 is coaxially disposed with the cylinder assembly 100, and the abutment 310 and the abutment 320 move together with the piston rod 300 when the piston rod 300 moves in the axial direction of the guide sleeve 200.

It is understood that the abutment member 310 is a nut sleeved on the extending end of the piston rod 300, and the abutment member 310 is fastened on the extending end of the piston rod 300 by means of the locking member 330, wherein the locking member 330 may be a locking screw. Of course, in other embodiments, the abutment 310 may be fixed to the insertion end of the piston rod 300 in other manners.

The abutting portion 320 is a step surface, the abutting portion 320 and the abutting piece 310 are spaced along the axial direction of the piston rod 300 and are oppositely arranged, and the abutting portion 320 is located at one side of the abutting piece 310 close to the guide sleeve 200.

Specifically, the piston rod 300 includes a large-diameter section, and a small-diameter section connected to the large-diameter section, where the large-diameter section and the small-diameter section are coaxially disposed, and the large-diameter section is inserted into the guide sleeve 200, and the small-diameter section extends into the cylinder assembly 100, and the extending end of the piston rod 300 is an end of the small-diameter section away from the large-diameter section, and the abutting portion 320 is a step surface between the large-diameter section and the small-diameter section.

The piston assembly 400 is disposed in the cylinder assembly 100, the piston assembly 400 includes a first piston 410 disposed outside the piston rod 300 and movable along an axial direction of the piston rod 300, and a second piston 420 disposed outside the piston rod 300 and movable along an axial direction of the piston rod 300, the first piston 410 and the second piston 420 are both defined between the abutting portion 320 and the abutting member 310, and the first piston 410 is disposed at a side of the second piston 420 adjacent to the abutting portion 320, and the guide sleeve 200 is further capable of limiting the first piston 410.

Specifically, the outer side wall of the first piston 410 and the outer side wall of the second piston 420 are in sealing engagement with the inner side wall of the cylinder assembly 100, and the inner side wall of the first piston 410 and the inner side wall of the second piston 420 are in movable engagement with the piston rod 300, and the first piston 410 and the second piston 420 are movable in the axial direction of the piston rod 300. The abutment 320 can abut against a side of the first piston 410 remote from the second piston 420, and the abutment 310 can abut against a side of the second piston 420 remote from the first piston 410, such that the first piston 410 and the second piston 420 can be defined between the abutment 320 and the abutment. In addition, the guide sleeve 200 also limits the first piston 410, preventing the first piston 410 from being pulled out of the cylinder assembly 100. And, the inside of the cylinder assembly 100 is provided with a limiting portion 104, the limiting portion 104 is located at one side of the second piston 420 away from the first piston 410, the limiting portion 104 is used for limiting the first piston 410, and when the second piston 420 abuts against the limiting portion 104, the piston rod 300 can still move continuously towards the inside of the cylinder assembly 100 so that the first piston 410 moves towards the second piston 420.

Specifically, the limiting portion 104 is located on an upper end surface of the base 120, and an upper end of the base 120 is configured to be inserted into the cylinder 110, so that the limiting portion 104 is disposed opposite to an edge of the second piston 420. The middle part of the base 120 is provided with an avoidance cavity for the penetration of the piston rod 300.

The elastic compression member 500 is disposed between the first piston 410 and the second piston 420, and the elastic compression member 500 is used to make the first piston 410 and the second piston 420 have a trend of being away from each other. In this way, in the initial state, the abutting portion 320 abuts against the side of the first piston 410 away from the second piston 420 under the action of the elastic compression element 500, and the abutting element 310 abuts against the side of the second piston 420 away from the first piston 410.

Specifically, the elastic compression member 500 is a spring, the spring is sleeved outside the piston rod 300, one end of the spring abuts against the first piston 410, and the other end of the spring abuts against the second spring.

Of course, in other embodiments, the elastic compression member 500 may be a spring.

A buffer chamber 401 is formed between the first piston 410 and the second piston 420, and the volume of the buffer chamber 401 varies with the relative position between the first piston 410 and the second piston 420, so that the smaller the volume of the buffer chamber 401 is when the first piston 410 and the second piston 420 are brought closer together.

Wherein the first piston 410 is provided with a first oil passage 411; the second piston 420 is provided with a second oil passing passage 421; one end of the first oil passage 411 is communicated with the rod cavity 103 of the cylinder assembly 100, and the other end is communicated with one end of the second oil passage 421; the other end of the second oil passage 421 communicates with the rodless chamber 102 of the cylinder assembly 100.

The piston assembly 400 divides the interior of the cylinder assembly 100 into a rod chamber 103 and a rodless chamber 102, the piston rod 300 is disposed in the rod chamber 103, and the rodless chamber oil port 101 communicates with the rodless chamber 102.

The first piston 410 and the second piston 420 can be close to each other or far away from each other, and at least before the first piston 410 and the second piston 420 are not abutted against each other, the other end of the first oil passage 411 and one end of the second oil passage 421 are both communicated with the buffer cavity 401.

Before the first piston 410 and the second piston 420 are not close to each other but are abutted against each other, the other end of the first oil passage 411 and one end of the second oil passage 421 are also in communication with the buffer chamber 401. In some embodiments, when the first piston 410 and the second piston 420 are close to each other and abut against each other, the other end of the first oil passing channel 411 and one end of the second oil passing channel 421 are also communicated with the buffer cavity 401; in other embodiments, the other end of the first oil passage 411 and/or one end of the second oil passage 421 are not in communication with the buffer chamber 401 when the first piston 410 and the second piston 420 are brought close to each other to abut.

It will be appreciated that the first piston 410 and the second piston 420, when in close proximity, can nest together and reduce the volume of the buffer chamber 401 to force out hydraulic oil within the buffer chamber 401.

Further, the first piston 410 is further provided with a third oil passage 412 communicating with the buffer chamber 401, the third oil passage 412 is sealed by the abutting portion 320 when the first piston 410 abuts against the abutting portion 320, and the third oil passage 412 communicates with the rod chamber 103 of the cylinder assembly 100 when the first piston 410 is separated from the abutting portion 320.

Specifically, one end of the third oil passage 412 communicates with the buffer chamber 401, the other end thereof is disposed opposite to the abutting portion 320, when the first piston 410 abuts against the abutting portion 320, the other end of the third oil passage 412 is sealed by the abutting portion 320, and when the first piston 410 is separated from the abutting portion 320, the other end of the third oil passage 412 communicates with the rod chamber 103 of the cylinder assembly 100.

The use principle of the hydraulic cylinder of the utility model is as follows:

as shown in fig. 1, when hydraulic oil is fed from the rodless cavity port 101, the hydraulic oil passes through the second oil passing channel 421 of the second piston 420 and the first oil passing channel 411 of the first piston 410 to reach the rod cavity 103, at this time, the hydraulic oil may also enter the buffer cavity 401, under the pressure of the elastic compression member 500 and the hydraulic oil, the first piston 410 may be kept against the abutment 320 of the piston rod 300, and the second piston 420 may be kept against the abutment 310, at this time, the combination of the first piston 410 and the second piston 420 and the piston rod 300 may be kept away from the rodless cavity port 101 under the pushing of the hydraulic oil.

When the posture of the hydraulic cylinder moves to the state shown in fig. 2, the first piston 410 abuts against the guide sleeve 200, when the hydraulic cylinder continues to feed oil into the rodless cavity oil port 101, the piston rod 300 together with the abutting piece 310 continues to drive the second piston 420 to move away from the rodless cavity oil port 101, the first piston 410 cannot continue to move away from the rodless cavity oil port 101 due to the blocking of the guide sleeve 200, the first piston 410 and the second piston 420 perform relative movement, a nested relation is formed between the first piston 410 and the second piston 420, when the piston rod 300 together with the abutting piece 310 continues to drive the second piston 420 to move away from the rodless cavity oil port 101, hydraulic oil in the buffer cavity 401 slowly flows out through a fit gap between the first piston 410 and the second piston 420, the running speed of the piston rod 300 is forced to be reduced until the second piston 420 abuts against the first piston 410, as shown in fig. 3, the piston rod 300 runs to an upper end point, and the rising buffering is completed.

When the rodless cavity oil port 101 is communicated with the oil return tank, the pressure of hydraulic oil in the hydraulic cylinder is reduced, when the load carried by the piston rod 300 is insufficient, the piston rod 300 starts to move towards the rodless cavity oil port 101, the second piston 420 is separated from the guide sleeve 200, hydraulic oil enters the buffer cavity 401 through the third oil passing channel 412, under the action of the elastic compression element 500, the first piston 410 moves upwards relative to the second piston 420 until the initial state is restored, when the combined body continues to descend, and the combined body moves to the state shown in fig. 4, the first piston 410 abuts against the abutting part 320, the second piston 420 abuts against the limiting part 104, the limiting part 104 can limit the second piston 420, the second piston 420 cannot continue to descend, the first piston 410 and the second piston 420 form a nested relation, when the piston rod 300 continues to drive the first piston 410 to descend together with the abutting element 310, the hydraulic oil in the buffer cavity 401 can slowly flow out through a fit clearance between the first piston 410 and the second piston 420 and a fit clearance between the second piston 420 and the piston 300 until the running speed of the piston 300 is forced to be reduced until the running speed of the first piston 410 abuts against the second piston 420 and the second piston 420 is reduced, as shown in fig. 5, and the piston rod 300 runs to the end point is finished.

The hydraulic cylinder has a compact structure, only the mutual matching precision of the first piston 410 and the second piston 420 and the mutual matching precision of the second piston 420 and the piston rod 300 are required to be ensured, the processing precision is easy to control, and the conventional precise matching of the buffer plunger and the welding type base is omitted, so that the aim of reducing the cost is fulfilled. In addition, the first piston 410 is in a floating state in the cylinder assembly 100 in the radial direction, and when the first piston 410 and the second piston 420 move relatively, the first piston and the second piston can be automatically centered, so that the mutual friction between the first piston and the second piston is reduced, a good buffering effect is ensured, and the service life is prolonged.

As shown in fig. 1, in the present embodiment, a first chamber 422 is disposed on a side of the second piston 420 near the first piston 410, and the first piston 410 can be inserted into the first chamber 422.

It will be appreciated that the first chamber 422 forms part of the buffer chamber 401, and that the first piston 410 is capable of penetrating into the first chamber 422 such that the first piston 410 and the second piston 420 nest with each other, and that the first piston 410 penetrates into the first chamber 422 and the volume of the buffer chamber 401 decreases as the first piston 410 approaches the first piston 410.

Referring to fig. 1 and 2, further, the first piston 410 includes a sealing portion 410a in sealing engagement with an inner sidewall of the cylinder assembly 100, and a penetrating portion 410b connected to the sealing portion 410a, the penetrating portion 410b is capable of penetrating into the first chamber 422, an outer sidewall of the penetrating portion 410b is spaced from the inner sidewall of the cylinder assembly 100, and an oil passing groove 413 is provided on an outer sidewall of the penetrating portion 410b, the oil passing groove 413 is in communication with the first oil passing channel 411, and the oil passing groove 413 is in communication with the second oil passing channel 421.

It will be appreciated that the sealing portion 410a is in sealing engagement with the inner side wall of the cylinder assembly 100, so that hydraulic oil can be prevented from flowing through the gap between the sealing portion 410a and the cylinder assembly 100, and the penetrating portion 410b can penetrate into the first chamber 422 until abutting against the bottom wall of the first chamber 422. The oil passing groove 413 is formed in the outer wall of the penetrating portion 410b, so that before the first piston 410 and the second piston 420 are not abutted, the oil passing groove 413 can communicate the first chamber 422 (the buffer chamber 401) with the first oil passing channel 411, and the oil passing groove 413 can also communicate the first chamber 422 (the buffer chamber 401) with the second oil passing channel 421, so that when the first piston 410 and the second piston 420 approach each other to press the hydraulic oil in the buffer chamber 401, the hydraulic oil can flow out through the gap between the first piston 410 and the second piston 420 and the oil passing groove 413.

It should be noted that, the first oil passage 411 is opened at the sealing portion 410a and penetrates the upper and lower surfaces of the sealing portion 410a, one end of the first oil passage 411 is communicated with the rod cavity 103 of the cylinder assembly 100, and the other end is communicated with the gap between the penetrating portion 410b and the inner sidewall of the cylinder assembly 100.

Further, one end of the second oil passing passage 421 communicates with the gap between the penetration portion 410b and the inner side wall of the cylinder assembly 100, and the other end communicates with the rodless chamber 102 of the cylinder assembly 100.

Further, a second chamber 414 is provided on a side of the penetrating portion 410b near the second piston 420, and the second chamber 414 communicates with the first chamber 422.

It will be appreciated that the second chamber 414 also forms part of the buffer chamber 401 such that when the first and second pistons 410, 420 are brought closer together, the volume of the buffer chamber 401 becomes smaller and when the first and second pistons 410, 420 are moved away from each other, the volume of the buffer chamber 401 becomes larger.

Further, the outer sidewall of the penetrating portion 410b is in guiding engagement with the sidewall of the first chamber 422. When the first piston 410 and the second piston 420 move relatively, the two pistons can be automatically centered, mutual friction between the two pistons is reduced, good buffering effect is ensured, and service life is prolonged.

Specifically, the outer diameter of the penetrating portion 410b is the same as the diameter of the first chamber 422, or the outer diameter of the penetrating portion 410b is slightly smaller than the diameter of the first chamber 422, and the outer sidewall of the penetrating portion 410b and the sidewall of the first chamber 422 can guide each other, so that the first piston 410 and the second piston 420 are automatically centered.

In some embodiments, the first piston 410 sealingly engages the guide sleeve 200 when it abuts the guide sleeve 200. That is, when the first piston 410 abuts against the guide bush 200, the guide bush 200 abuts against the first piston 410, and the guide bush 200 can seal the first piston 410, thereby preventing leakage of hydraulic oil.

In some embodiments, the second piston 420 is in sealing engagement with the abutment 310 when it abuts the abutment 310. That is, when the second piston 420 abuts against the abutment 310, the abutment 310 abuts against the second piston 420, and the abutment 310 can seal the second piston 420, thereby avoiding leakage of hydraulic oil.

In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the utility model. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present utility model have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the spirit and principles of the utility model, the scope of which is defined by the claims and their equivalents.

Claims

1. A hydraulic cylinder, comprising:

the cylinder body assembly is provided with a rodless cavity oil port at one end and a guide sleeve at the other end;

the piston rod is movably arranged in the guide sleeve in a penetrating mode, the extending end of the piston rod extends into the cylinder body assembly, the extending end of the piston rod is fixedly connected with a supporting piece, the side wall of the piston rod is provided with a supporting portion which is spaced from the supporting piece, and the supporting portion is located on one side, close to the guide sleeve, of the supporting piece;

the piston assembly is positioned in the cylinder assembly, the piston assembly comprises a first piston sleeved outside the piston rod and capable of moving along the axial direction of the piston rod, and a second piston sleeved outside the piston rod and capable of moving along the axial direction of the piston rod, the first piston and the second piston are both limited between the supporting part and the supporting part, the first piston is positioned on one side, close to the supporting part, of the second piston, a limiting part is further arranged in the cylinder assembly, the limiting part is positioned on one side, far away from the first piston, of the second piston, and an elastic compression part is arranged between the first piston and the second piston;

2. The hydraulic cylinder according to claim 1, wherein a first chamber is provided on a side of the second piston adjacent to the first piston, and the first piston is capable of penetrating into the first chamber.

3. The hydraulic cylinder according to claim 2, wherein the first piston includes a sealing portion in sealing engagement with an inner side wall of the cylinder block assembly, and a penetrating portion connected to the sealing portion, the penetrating portion being capable of being penetrated into the first chamber, an outer side wall of the penetrating portion being spaced apart from the inner side wall of the cylinder block assembly, and an outer side wall of the penetrating portion being provided with an oil passing groove, the oil passing groove being in communication with the other end of the first oil passing passage, and the oil passing groove being in communication with one end of the second oil passing passage.

4. A hydraulic cylinder according to claim 3, wherein the first oil passage is provided in the sealing portion, and the other end of the first oil passage communicates with a gap between an outer side wall of the penetrating portion and an inner side wall of the cylinder block assembly.

5. A hydraulic cylinder according to claim 3, wherein one end of the second oil passage communicates with a gap between an outer side wall of the penetration and an inner side wall of the cylinder block assembly.

6. A hydraulic cylinder according to claim 3, wherein a second chamber is provided on a side of the penetrating portion adjacent to the second piston, the second chamber being in communication with the first chamber, and the third oil passage being in communication with the second chamber.

7. A hydraulic cylinder according to claim 3, wherein the outer side wall of the penetration is in guided engagement with the side wall of the first chamber.

8. The hydraulic cylinder of claim 1, wherein the resilient compression member is a spring, the spring being disposed about the piston rod.

9. The hydraulic cylinder according to claim 1, wherein the cylinder block assembly includes a cylinder tube and a base provided at one end of the cylinder tube, and the guide bush is provided inside the other end of the cylinder tube.

10. The hydraulic cylinder according to claim 1, wherein one end of the third oil passage communicates with the buffer chamber, the other end is disposed opposite to the abutting portion, the other end of the third oil passage is sealed by the abutting portion when the first piston abuts against the abutting portion, and the other end of the third oil passage communicates with the rod chamber of the cylinder assembly when the first piston is separated from the abutting portion.