CN215672963U - Hydraulic cylinder, swing valve hydraulic cylinder assembly and concrete pump truck - Google Patents

Abstract

The embodiment of the utility model provides a hydraulic cylinder, a swing valve oil cylinder and a concrete pump truck. The hydraulic cylinder includes: cylinder, piston rod subassembly, buffer unit and valves. The piston rod assembly extends to the inside of cylinder by the outside of cylinder, the piston rod assembly can do reciprocating telescopic motion for the cylinder, the inside of cylinder is equipped with buffer assembly for reduce the flexible impact force of piston rod assembly, the inside of cylinder still installs the valves, is used for improving the velocity of extension of piston rod assembly. The hydraulic cylinder provided by the utility model is internally provided with the buffering assembly and the valve group. The buffer assembly can reduce the impact force generated when the piston rod assembly contracts, improve the buffer effect of the hydraulic cylinder and reduce the buffer vibration peak value of the hydraulic cylinder. The valve group can improve the extending speed of the piston rod assembly, and further improve the response speed of the hydraulic cylinder.

Description

Hydraulic cylinder, swing valve hydraulic cylinder assembly and concrete pump truck

Technical Field

The utility model relates to the technical field of hydraulic cylinders, in particular to a hydraulic cylinder, a swing valve hydraulic cylinder assembly and a concrete pump truck.

Background

Hydraulic cylinders are important actuators in hydraulic systems. The hydraulic cylinder can convert hydraulic energy into mechanical energy and is matched with various transmission mechanisms to complete various mechanical motions. The hydraulic cylinder has the characteristics of simple structure, large output force, stable and reliable performance and the like.

In the hydraulic cylinder used at present, the extension speed of the piston rod assembly when extending is slow. Meanwhile, a special buffer device is not arranged in the hydraulic cylinder, and the piston rod assembly can be greatly impacted when being contracted.

For example, a swing valve cylinder is provided in a main machine of a working machine such as a pump truck, an in-vehicle pump, and a wet jet machine. The swing valve oil cylinder is used for enabling the S valve in the hopper to be in seamless butt joint with the concrete cylinder. The left and right swing valve oil cylinders are used in pairs. The swing valve oil cylinder has the characteristics of high action frequency, large impact force, large vibration and the like. The existing swing valve oil cylinder has poor buffering effect, and the peak value of buffering vibration is large when reversing is carried out.

SUMMERY OF THE UTILITY MODEL

The utility model provides a hydraulic cylinder, a swing valve hydraulic cylinder assembly and a concrete pump truck, which are used for solving the problems that a piston rod assembly of the hydraulic cylinder in the prior art is slow in extension speed and large in impact force when the piston rod assembly contracts, and achieving the effects of improving the extension speed of the piston assembly and improving the buffering effect of the piston rod assembly.

According to a first aspect of the present invention, there is provided a hydraulic cylinder comprising: cylinder, piston rod subassembly, buffer unit and valves.

The piston rod assembly extends from the outside of the cylinder barrel to the inside of the cylinder barrel, and can do reciprocating telescopic motion relative to the cylinder barrel. And a buffer assembly is arranged in the cylinder barrel and used for reducing the telescopic impact force of the piston rod assembly. And a valve bank is further arranged in the cylinder barrel and used for improving the extending speed of the piston rod assembly.

According to the hydraulic cylinder provided by the utility model, the piston rod assembly comprises a piston rod and a piston. The piston rod extends from the outside of the cylinder to the inside of the cylinder. The piston is located inside the cylinder barrel and sleeved at the right end of the piston rod. The piston rod and the piston can move in a telescopic mode along the length direction of the cylinder barrel.

According to the hydraulic cylinder provided by the utility model, the cylinder barrel comprises the end cover. The end cover is installed at the right end of the cylinder barrel. The buffer assembly comprises a buffer head and a buffer hole. A plurality of sections of buffer joints are formed on the buffer head. A rod cavity and a rodless cavity are formed inside the cylinder barrel.

And the oil inlet and return port of the rodless cavity is communicated with the buffer hole. The buffer head is located in the rodless cavity and connected with the piston. The end cover is provided with the buffer hole matched with the buffer head. The buffering head can move in the buffering hole, and the taper of each buffering section is gradually increased along the direction from left to right so as to reduce the telescopic impact force of the piston rod assembly.

According to the hydraulic cylinder provided by the utility model, the buffer head is in clearance fit with the buffer hole, so that part of hydraulic oil between the piston and the end cover can flow to the oil inlet and return port of the rodless cavity through the fit clearance between the buffer head and the buffer hole and is discharged.

According to the hydraulic cylinder provided by the utility model, the valve group comprises an integrated one-way valve. The end cover is provided with a first mounting hole. The integrated one-way valve is inserted into the first mounting hole. And the oil inlet of the integrated one-way valve is communicated with the oil inlet and return port of the rodless cavity. And an oil outlet of the integrated one-way valve is communicated with the rodless cavity.

According to the hydraulic cylinder provided by the utility model, the end cover is also provided with a second mounting hole. And a damping plug is arranged in the second mounting hole. The damping plug is provided with a damping hole. The damping hole is communicated with the rodless cavity and the oil inlet and return ports of the rodless cavity.

According to the hydraulic cylinder provided by the utility model, the hydraulic cylinder further comprises a guide sleeve. The guide sleeve is installed at one end of the cylinder barrel. The piston rod penetrates through the guide sleeve and extends to the inner part of the cylinder barrel.

According to the hydraulic cylinder provided by the utility model, a static sealing device is arranged between the guide sleeve and the cylinder barrel. And dynamic sealing devices are arranged between the guide sleeve and the piston rod and between the piston and the cylinder barrel.

According to a second aspect of the present invention, there is provided a pendulum valve hydraulic cylinder assembly comprising a hydraulic cylinder as described above.

Wherein the piston rod assembly comprises a piston rod and a piston. The piston rod extends from the outside of the cylinder to the inside of the cylinder. The piston is positioned in the cylinder barrel and is connected with the inner end part of the piston rod. The piston can drive the piston rod to stretch along the length direction of the cylinder barrel. The cylinder includes an end cap.

And a first connecting ball head for connecting an S pipe of the concrete pump truck is formed at the outer end part of the piston rod. And a second connecting ball head for fixed installation is formed on the outer side of the end cover.

According to a third aspect of the utility model, a concrete pump truck is provided, comprising two swing valve hydraulic cylinder assemblies as described above and an S-pipe.

And two sides of the S pipe are respectively and correspondingly provided with one swing valve hydraulic cylinder assembly. And the first connecting ball head of each swing valve hydraulic cylinder assembly is connected with the S pipe so as to drive the S pipe to circularly swing.

In the hydraulic cylinder provided by the utility model, the piston rod assembly extends from the outside of the cylinder barrel to the inside of the cylinder barrel, and the piston rod assembly can do reciprocating telescopic motion relative to the cylinder barrel. And a buffer assembly is arranged in the cylinder barrel and used for reducing the telescopic impact force of the piston rod assembly. And a valve bank is further arranged in the cylinder barrel and used for improving the extending speed of the piston rod assembly.

According to the utility model, the buffer assembly can reduce the impact force when the piston rod assembly contracts, improve the buffer effect of the hydraulic cylinder and reduce the buffer vibration peak value of the hydraulic cylinder. The valve group can improve the extending speed of the piston rod assembly, and further improve the response speed of the hydraulic cylinder.

Further, in the swing valve hydraulic cylinder assembly provided by the utility model, since the swing valve hydraulic cylinder assembly comprises the hydraulic cylinder, the advantages are also provided.

Furthermore, in the concrete pump truck provided by the utility model, because the concrete pump truck comprises the swing valve hydraulic cylinder assembly, the concrete pump truck also has the advantages as described above.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic structural view of a hydraulic cylinder or a swing valve hydraulic cylinder assembly provided by the present invention;

FIG. 2 is a schematic structural view of a piston rod assembly and a damping head of the hydraulic cylinder or the swing valve hydraulic cylinder assembly provided by the present invention;

reference numerals:

100: a cylinder barrel; 101: an end cap; 102: a rod cavity;

103: a rodless cavity; 104: a second connecting ball head; 200: a piston rod assembly;

201: a piston rod; 202: a piston; 203: a first connecting ball head;

300: a buffer assembly; 301: a buffer head; 302: a buffer hole;

303: a first buffer section; 304: a second buffer section; 305: a third buffer section;

400: an integral one-way valve; 501: a first mounting hole; 502: a second mounting hole;

601: a damping plug; 602: a plug screw; 700: a guide sleeve;

801: a static seal device; 802: and a dynamic sealing device.

Detailed Description

The embodiments of the present invention will be described in further detail with reference to the drawings and examples. The following examples are intended to illustrate the utility model but are not intended to limit the scope of the utility model.

In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the embodiments of the present invention and simplifying the description, but do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the embodiments of the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the embodiments of the present invention, it should be noted that, unless explicitly stated or limited otherwise, the terms "connected" and "connected" are to be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. Specific meanings of the above terms in the embodiments of the present invention can be understood in specific cases by those of ordinary skill in the art.

In embodiments of the utility model, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through intervening media. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean 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 an embodiment of the utility model. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art may combine and combine different embodiments or examples and features of different embodiments or examples described in this specification to make the purpose, technical solution, and advantages of the embodiments of the present invention more clear, and the technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are a part of embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

A hydraulic cylinder, a swing valve hydraulic cylinder assembly and a concrete pump truck according to an embodiment of the present invention will be described with reference to fig. 1 and 2. It should be understood that the following description is only exemplary embodiments of the present invention and does not constitute any particular limitation of the present invention.

An embodiment of the first aspect of the present invention provides a hydraulic cylinder, as shown in fig. 1, comprising: cylinder 100, piston rod assembly 200, cushion assembly 300, and valve block.

Wherein the piston rod assembly 200 extends from the outside of the cylinder 100 to the inside of the cylinder 100. The piston rod assembly 200 is capable of reciprocating telescopic movement relative to the cylinder tube 100. The cylinder tube 100 is provided at the inside thereof with a buffering assembly 300 for reducing the impact force of the extension and contraction of the piston rod assembly 200. A valve block is further installed inside the cylinder 100 to increase the extension speed of the piston rod assembly 200.

In the utility model, the buffer assembly 300 can reduce the impact force when the piston rod assembly 200 extends and retracts, improve the buffer effect of the hydraulic cylinder and reduce the buffer vibration peak value of the hydraulic cylinder. The valve block can increase the extension speed of the piston rod assembly 200, thereby increasing the response speed of the hydraulic cylinder.

In one embodiment of the present invention, the piston rod assembly 200 includes a piston rod 201 and a piston 202. The piston rod 201 extends from the outside of the cylinder 100 to the inside of the cylinder 100. The piston 202 is located inside the cylinder 100 and is sleeved on the right end of the piston rod 201. The piston rod 201 and the piston 202 are capable of extending and contracting in the longitudinal direction of the cylinder 100.

For example, as shown in fig. 1 and 2, the piston rod 201 is disposed coaxially with the cylinder tube 100. The left end of the piston rod 201 passes through the left end surface of the cylinder 100 and extends to the outside of the cylinder 100. The right end of the piston rod 201 extends to the inside of the cylinder 100. The piston 202 is disposed inside the cylinder 100 and connected to the right end of the piston rod 201.

In one embodiment of the utility model, the cylinder barrel 100 includes an end cap 101. An end cap 101 is mounted on the right end of the cylinder 100. The buffer assembly 300 includes a buffer head 301 and a buffer hole 302. The buffer head 301 is formed with a plurality of buffer segments. The cylinder tube 100 is formed with a rod chamber 102 and a rodless chamber 103 inside.

Wherein, the oil inlet and return port of the rodless chamber 103 is communicated with the buffer hole 302. A cushion head 301 is located within the rodless chamber 103 and is connected to the piston 202. The end cap 101 is formed with a buffer hole 302 to be fitted with the buffer head 301. The buffer head 301 can move inside the buffer hole 302. And, the taper of each cushion segment is gradually increased along the left-to-right direction to reduce the expansion impact force of the piston rod assembly 200.

Specifically, for example, as shown in fig. 1 and 2, the piston 202 is sleeved on the right end of the piston rod 201, the right end of the piston rod 201 is exposed outside the piston 202, a buffer head 301 is formed on the end of the piston rod 201 exposed outside the piston 202, and a plurality of conical buffer joints with different tapers are formed on the buffer head 301.

For example, the buffer head 301 is formed with a first buffer node 303, a second buffer node 304, and a third buffer node 305. In order, in a direction away from the piston 202, are a third damping section 305, a second damping section 304, and a first damping section 303. The taper of the first buffer section 303 is greater than that of the second buffer section 304, and the taper of the second buffer section 304 is greater than that of the third buffer section 305.

The end cap 101 is formed with a buffer hole 302 adapted to the buffer head 301, so that the buffer head 301 can move in the buffer hole 302 and buffer the piston rod assembly 200. During the process of moving the piston rod 201 to the right, the three segments of the buffer joints on the buffer head 301 gradually get close to the right and move into the buffer holes 302.

Because the taper of the first buffer joint 303 is the largest, when the first buffer joint 303 is close to and extends into the buffer hole 302, the first buffer joint 303 can be effectively prevented from colliding with the inner wall surface of the buffer hole 302, and the impact force of the hydraulic oil on the piston rod assembly 200 can be reduced.

When the second buffering section 304 approaches and extends into the buffering hole 302, the buffering pressure is increased due to the smaller taper of the second buffering section 303 than that of the first buffering section 303, thereby further reducing the impact of the hydraulic oil on the piston rod assembly 200.

When the third buffering section 305 approaches and extends into the buffering hole 302, the buffering pressure is further increased due to the smaller taper of the third buffering section 305 compared with the taper of the second buffering section 304, thereby further reducing the impact force of the hydraulic oil on the piston rod assembly 200.

During specific operation, when hydraulic oil is injected into the rodless cavity 103 of the hydraulic cylinder, the piston 202 and the piston rod 201 both move leftward along the length direction of the cylinder tube 100, and the piston rod 201 extends out of the cylinder tube 100.

When hydraulic oil is injected into the rod chamber 102 of the hydraulic cylinder, the piston rod 201 and the piston 202 both move rightward along the length direction of the cylinder tube 100, and the piston rod 201 is gradually retracted into the cylinder tube 100. During the process that the piston rod 201 and the piston 202 move rightwards, hydraulic oil in the rodless cavity 103 is slowly drained out of an oil inlet and return port in the rodless cavity 103 after smooth buffering transition of the first buffering joint 303, the second buffering joint 304 and the third buffering joint 305. The impact of the hydraulic oil on the piston rod assembly 200 is slowly released, thereby greatly reducing the reversing vibration amplitude of the hydraulic cylinder.

It should be noted that the above-mentioned embodiment is only an illustrative embodiment of the present invention, and does not constitute any limitation to the present invention. The number of the buffer nodes formed on the buffer head 301 is not limited in any way. That is, the number of the buffer sections is not limited to the three sections described in the above embodiment.

In an embodiment of the present invention, a clearance fit is provided between the buffer head 301 and the buffer hole 302, so that a part of hydraulic oil between the piston 202 and the end cover 101 can flow to the oil inlet and return port of the rodless cavity 103 through the fit clearance between the buffer head 301 and the buffer hole 302 and be discharged.

According to the above-described embodiment, when the piston 202 moves right to a position immediately adjacent to the right end cover 101 of the cylinder tube 100, there is partially pressed hydraulic oil between the piston 202 and the end cover 101. The part of hydraulic oil can flow into the buffer hole 302 from the fit clearance between the buffer head 301 and the buffer hole 302, and then is discharged into the oil tank from the oil inlet and return port of the rodless cavity 103.

In one embodiment of the utility model, the valve block includes an integral check valve 400. The end cap 101 is provided with a first mounting hole 501. The integrated check valve 400 is inserted into the first mounting hole 501. And the oil inlet of the integrated check valve 400 is communicated with the oil inlet and the oil return port of the rodless cavity 103. The oil outlet of the integrated check valve 400 communicates with the rodless chamber 103.

Specifically, as shown in fig. 1, a first mounting hole 501 is formed in the end cover 101, and the integrated check valve 400 is inserted into the first mounting hole 501. An oil inlet of the integrated one-way valve 400 is communicated with an oil inlet and an oil outlet of the rodless cavity 103, and an oil outlet of the integrated one-way valve 400 is communicated with the rodless cavity 103 of the hydraulic cylinder. In the process that the piston rod 201 moves to the left, hydraulic oil is introduced into the buffer hole 302 through the oil inlet and return port of the rodless cavity 103, and the hydraulic oil in the buffer hole 302 pushes the buffer head 301, so that the buffer head 301 drives the piston 202 and the piston rod 201 to move to the left. Meanwhile, part of the hydraulic oil at the oil inlet and the oil return port of the rodless cavity 103 flows into the rodless cavity 103 through the oil inlet and the oil return port of the integrated check valve 400, and generates thrust on the piston 202. Thereby, the extension speed of the piston rod assembly 200 can be greatly increased.

Meanwhile, compared with the hydraulic cylinder using the fabricated check valve, by directly mounting the integrated check valve 400 in the first mounting hole 501, the assembling speed of the hydraulic cylinder can be increased and assembling accidents can be prevented.

In an embodiment of the present invention, the end cap 101 further has a second mounting hole 502. A damper plug 601 is installed in the second installation hole 502. A damping hole is formed in the damping plug 601. The damping hole is communicated with the rodless chamber 103 and an oil inlet and return port of the rodless chamber 103.

As shown in fig. 1, a damping plug 601 is installed in the second installation hole 502 of the end cap 101, and a damping hole is formed in the damping plug 601, and both ends of the damping hole are respectively communicated with the oil inlet and return port of the rodless chamber 103 and the rodless chamber 103. With this arrangement, during the rightward movement of the piston rod assembly 200, a part of the hydraulic oil in the rod-less chamber 103 can flow to the oil inlet and return ports of the rod-less chamber 103 through the damping hole and be discharged. Therefore, the oil discharge speed of the rodless cavity 103 can be further reduced, and a certain buffer effect is further exerted on the piston rod assembly 200. Meanwhile, a plug screw 602 for preventing hydraulic oil from leaking to the outside of the cylinder tube 100 through the damping plug 601 should be further installed at the outer end portion of the damping plug 601.

In addition, the auxiliary buffering effect of the damping hole can be flexibly adjusted by changing the diameter of the damping hole.

In one embodiment of the present invention, the hydraulic cylinder further comprises a guide sleeve 700. The guide sleeve 700 is installed at one end of the cylinder tube 100. The piston rod 201 extends through the guide sleeve 700 to the inside of the cylinder 100.

Further, in one embodiment of the present invention, a static seal 801 is provided between the guide sleeve 700 and the cylinder tube 100. Dynamic seal devices 802 are provided between the guide sleeve 700 and the piston rod 201 and between the piston 202 and the cylinder tube 100.

According to the above-described embodiment, as shown in fig. 1, the guide sleeve 700 is mounted on the left end portion of the cylinder tube 100, and the piston rod 201 is inserted into the cylinder tube 100 through the guide sleeve 700. Therefore, a guiding effect can be generated on the movement of the piston rod 201, and the service life of the piston rod 201 can be effectively prolonged while the movement precision of the piston rod 201 is ensured. Further, by providing the static seal devices 801 between the guide sleeve 700 and the cylinder 100 and the dynamic seal devices 802 between the guide sleeve 700 and the piston rod 201 and between the piston 202 and the cylinder 100, the sealing performance of the hydraulic cylinder can be improved, and the operation accuracy of the hydraulic cylinder can be improved.

Embodiments of a second aspect of the utility model provide a pendulum valve hydraulic cylinder assembly comprising a hydraulic cylinder as described above.

The piston rod assembly 200 includes a piston rod 201 and a piston 202. The piston rod 201 extends from the outside of the cylinder 100 to the inside of the cylinder 100. The piston 202 is located inside the cylinder 100 and connected to the inner end of the piston rod 201. The piston 202 can extend and contract the piston rod 201 along the longitudinal direction of the cylinder 100. The cylinder barrel 100 includes an end cap 101.

Wherein, the outer end of the piston rod 201 is formed with a first connecting ball 203 for connecting the S pipe of the concrete pump truck. The outer side of the end cap 101 is formed with a second connecting bulb 104 for fixed mounting.

As shown in fig. 1 and 2, a first connecting ball 203 is provided on the left end of the piston rod 201, and a second connecting ball 104 is formed on the outer side of the end cap 101. Wherein the first connecting bulb 203 is connected with an S-tube (not shown in the figure) to drive the S-tube to swing. The second connecting bulb 104 is connected to a concrete pump truck (not shown) to fixedly mount the swing valve hydraulic cylinder assembly.

Embodiments of a third aspect of the present invention provide a concrete pump truck comprising the swing valve hydraulic cylinder assembly and the S-pipe as described above.

Wherein, the both sides of S pipe correspond respectively and set up a pendulum valve hydraulic cylinder subassembly. The first connecting ball 203 of each swing valve hydraulic cylinder assembly is connected with the S pipe to drive the S pipe to swing circularly.

According to the above-described embodiment, each S-pipe should be configured with two pendulum valve hydraulic cylinder assemblies. Each swing valve hydraulic cylinder assembly is rotatably connected with the S pipe through a first connecting ball head 203. Therefore, the two swing valve hydraulic cylinder assemblies can be matched with each other to drive the circulating swing action of the S pipe.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims (10)

1. A hydraulic cylinder, comprising: a cylinder barrel, a piston rod assembly, a buffer assembly and a valve group,

the piston rod assembly extends to the inside of the cylinder barrel from the outside of the cylinder barrel, the piston rod assembly can do reciprocating telescopic motion relative to the cylinder barrel, a buffer assembly is arranged inside the cylinder barrel and used for reducing telescopic impact force of the piston rod assembly, and a valve group is further arranged inside the cylinder barrel and used for improving the extending speed of the piston rod assembly.

2. The hydraulic cylinder according to claim 1, wherein the piston rod assembly comprises a piston rod and a piston, the piston rod extends from the outside of the cylinder barrel to the inside of the cylinder barrel, the piston is located in the inside of the cylinder barrel and sleeved at the right end of the piston rod, and the piston rod and the piston can move telescopically along the length direction of the cylinder barrel.

3. The hydraulic cylinder of claim 2, wherein the cylinder barrel includes an end cap mounted at a right end of the cylinder barrel, the cushion assembly includes a cushion head and a cushion hole, a plurality of sections of cushion segments are formed on the cushion head, a rod chamber and a rodless chamber are formed in the cylinder barrel,

the buffering head is positioned in the rodless cavity and connected with the piston rod, the end cover is provided with the buffering hole matched with the buffering head, the buffering head can move inside the buffering hole, and the taper of each buffering section is gradually increased along the direction from left to right so as to reduce the telescopic impact force of the piston rod assembly.

4. The hydraulic cylinder of claim 3, wherein the buffer head is in clearance fit with the buffer hole, so that part of hydraulic oil between the piston and the end cover can flow to the oil inlet and return port of the rodless cavity through the fit clearance between the buffer head and the buffer hole and be discharged.

5. The hydraulic cylinder according to claim 3, wherein the valve assembly comprises an integrated check valve, the end cover is provided with a first mounting hole, the integrated check valve is inserted into the first mounting hole, an oil inlet of the integrated check valve is communicated with an oil inlet and an oil outlet of the rodless cavity, and an oil outlet of the integrated check valve is communicated with the rodless cavity.

6. The hydraulic cylinder according to claim 3, wherein a second mounting hole is further formed in the end cover, a damping plug is mounted in the second mounting hole, a damping hole is formed in the damping plug, and the damping hole is communicated with the rodless cavity and the oil inlet and return port of the rodless cavity.

7. The hydraulic cylinder of claim 2, further comprising a guide bushing mounted at one end of the cylinder tube, the piston rod extending through the guide bushing to an interior of the cylinder tube.

8. The hydraulic cylinder according to claim 7, wherein a static seal is provided between the guide sleeve and the cylinder barrel, and a dynamic seal is provided between the guide sleeve and the piston rod and between the piston and the cylinder barrel.

9. A swing valve hydraulic cylinder assembly, characterized by comprising the hydraulic cylinder of any one of claims 1 to 8,

wherein the piston rod assembly comprises a piston rod and a piston, the piston rod extends from the outside of the cylinder barrel to the inside of the cylinder barrel, the piston is positioned in the cylinder barrel and is connected with the inner end part of the piston rod, the piston can drive the piston rod to extend and retract along the length direction of the cylinder barrel, the cylinder barrel comprises an end cover,

the outer end of the piston rod is provided with a first connecting ball head used for connecting an S pipe of a concrete pump truck, and the outer side of the end cover is provided with a second connecting ball head used for fixed installation.

10. A concrete pump truck comprising two swing valve hydraulic cylinder assemblies as claimed in claim 9 and an S pipe,

the two sides of the S pipe are respectively and correspondingly provided with one swing valve hydraulic cylinder assembly, and a first connecting ball head of each swing valve hydraulic cylinder assembly is connected with the S pipe to drive the S pipe to circularly swing.

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