Piston rod end head for shock absorption of reciprocating motion of hydraulic cylinder of pump truck

Abstract

The utility model belongs to concrete pump truck technical field especially, is a kind of pump truck hydraulic cylinder reciprocating motion shock absorbing piston rod end, to the existing pump truck hydraulic cylinder piston rod high frequency commutation impact vibration is easy to produce, in the shock absorbing technology of existing piston rod end, two-way buffering effect is unstable and difficult to cope with instantaneous severe load and other problems, present and propose the following scheme, including end sleeve and mounting ring, the mounting ring fixed mounting in the one end of end sleeve;Still include connecting rod and first piston block, the first piston block fixed mounting in one end of connecting rod, the first piston block and the inner wall of end sleeve sliding fit, in the utility model, the end head is absorbed conventional impact by two-way mechanical buffer structure, and instantaneous severe load is coped with in combination with hydraulic damping system;Double shock absorbing mechanism can reduce piston rod commutation vibration, improve working stability;Integral structure can effectively disperse peak stress, reduce component fatigue damage, prolong equipment service life.

Description

Technical Field

[0001] This utility model relates to the field of concrete pump truck technology, and in particular to a shock-absorbing piston rod end for the reciprocating motion of a pump truck hydraulic cylinder. Background Technology

[0002] In the operation of a concrete pump truck's hydraulic cylinder, the reciprocating motion of the piston rod is a crucial action. During concrete pumping, the hydraulic cylinder needs to reciprocate frequently with a long stroke to drive the delivery cylinder to push the concrete. When the piston rod reaches the end of its stroke and needs to reverse direction, it generates a huge inertial impact and vibration. This impact and vibration not only affect the overall stability and working accuracy of the pump truck, but also cause serious mechanical damage to the piston rod and its related components, reducing the equipment's service life and increasing maintenance costs and downtime.

[0003] However, existing piston rod end damping technologies have many shortcomings. Some damping devices use only a single spring buffer structure, which can absorb impact energy to a certain extent, but the spring is prone to fatigue failure during repeated compression and extension, leading to a gradual decrease in damping effect. Moreover, a single spring structure is difficult to achieve effective bidirectional buffering of the piston rod's reciprocating motion, and its buffering performance is not stable enough when facing impact forces from different directions.

[0004] Meanwhile, existing shock absorption technologies often lack effective countermeasures when the piston rod is subjected to severe loads in an instant, making it difficult to absorb and disperse the instantaneous impact force in a timely and effective manner, which can easily lead to damage to the piston rod and related components under impact.

[0005] To address the aforementioned problems, this utility model document proposes a shock-absorbing piston rod end for the reciprocating motion of a pump truck hydraulic cylinder. Utility Model Content

[0006] The purpose of this invention is to address the shortcomings of existing technologies, such as the high-frequency reversal of the piston rod in the hydraulic cylinder of a pump truck easily generating impact vibrations, and the unstable bidirectional buffering effect and difficulty in coping with instantaneous severe loads in existing piston rod end shock absorption technologies. Therefore, this invention proposes a shock-absorbing piston rod end for the reciprocating motion of the hydraulic cylinder of a pump truck.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A reciprocating shock-absorbing piston rod end for a pump truck hydraulic cylinder includes:

[0009] An end sleeve and a mounting ring, wherein the mounting ring is fixedly connected to one end of the end sleeve;

[0010] A connecting rod and a first piston block, the first piston block being fixedly connected to one end of the connecting rod, the first piston block being axially slidingly engaged with the inner wall of the end sleeve, one end of the end sleeve being fixedly connected to an end cap by bolts, and one end of the connecting rod slidingly penetrating the end cap;

[0011] The first buffer assembly includes two springs and multiple rubber protrusions, with the two springs distributed axially on both sides of the first piston block;

[0012] And a second buffer assembly, including a fixing rod fixed to the mounting ring, the other end of the fixing rod sealingly sliding through the first piston block and extending into a buffer chamber opened inside the connecting rod, the end of the fixing rod being fixed to the second piston block, the second piston block being sealingly slidingly engaged with the buffer chamber, the buffer chamber being filled with fluid and having a connecting tube, the two ends of the connecting tube connecting to the buffer chamber, and the second piston block being located between the two ends of the connecting tube;

[0013] When the first piston block moves, it compresses a spring on one side and squeezes a rubber protrusion to generate frictional resistance. At the same time, the second piston block pushes the fluid through a connected thin tube to form damping.

[0014] In one possible design, both springs are located inside the end sleeve, with one spring sleeved on the outer wall of the connecting rod. One end of each spring abuts against the first piston block, and the other end abuts against the inner wall of the end sleeve and one side of the adjacent end cap, respectively.

[0015] In one possible design, the first buffer assembly further includes four limiting protrusions fixed to the inner wall of the end sleeve. The four limiting protrusions are evenly distributed circumferentially, and each limiting protrusion has an installation groove. The multiple rubber protrusions are locked in the corresponding installation grooves.

[0016] In one possible design, four limiting grooves are formed on the outer wall of the first piston block, and the inner walls of the four limiting grooves are slidably connected to the outer walls of the corresponding limiting protrusions.

[0017] In one possible design, one side of the plurality of rubber protrusions has two inclined surfaces and is concave in the middle and convex at both ends. When the first piston block moves, the inclined surfaces are squeezed and slid against the inner wall of the corresponding limiting groove to generate progressive frictional resistance.

[0018] In one possible design, the diameter of the connecting tube is much smaller than the radial dimension of the buffer chamber.

[0019] In one possible design, an injection tube is provided inside the connecting rod, the injection tube is connected to the end of the buffer chamber away from the first piston block, and the outlet of the injection tube penetrates through the outer wall of the connecting rod.

[0020] In one possible design, the outer wall of the connecting rod is fixed with an internal threaded connector, which corresponds to the outlet of the injection tube and is connected to a threaded sealing plug.

[0021] In one possible design, the end of the connecting rod away from the first piston block is fixed to a second fixing plate, and the second fixing plate is fixedly connected to the first fixing plate at the end of the piston rod body by bolts.

[0022] In this application, during use, the entire end is bolted to the first fixing plate at one end of the piston rod body via a second fixing plate at one end of the connecting rod, thus completing the installation. The mounting ring can be used for movable connection with external equipment.

[0023] When the piston rod body drives the external device to its limit through the movable end, the motion is transmitted to the end sleeve. The movable end, composed of the end sleeve, the internal connecting rod, and the first piston block, has a relative motion tendency. At this time, the limiting protrusion fixed to the inner wall of the end sleeve slides along the limiting groove on the outer wall of the first piston block.

[0024] When the first piston block moves, it pushes the spring on the corresponding side, which is compressible and absorbs energy. Simultaneously, the first piston block slides along the limiting protrusion, causing the inclined surface of the rubber protrusion within the limiting protrusion to make compression contact with the inner wall of the limiting groove. The rubber protrusion deforms under the compression of the first piston block, increasing its sliding friction resistance. This friction resistance, combined with the compression resistance of the spring, buffers the movement of the first piston block in the corresponding direction, thus providing cushioning for the entire movable end.

[0025] Meanwhile, the rubber convex strip, with its concave center and convex sides, combined with the springs on both sides of the first piston block, can ensure bidirectional buffering of the first piston block, thus facilitating effective shock absorption of the pump truck hydraulic cylinder piston rod during reciprocating motion.

[0026] When the first piston block moves, the fixed rod can move relative to the connecting rod and the first piston block. The fixed rod can drive the second piston block at one end to slide within the buffer chamber inside the connecting rod. The back-and-forth movement of the second piston block pushes the fluid in the buffer chambers on both sides, forcing the fluid to flow through the connecting tube inside the connecting rod, from one side of the second piston block to the other. Due to the small diameter of the connecting tube, the speed of fluid transfer is limited; when the movable end is subjected to a sudden impact force and moves rapidly, the second piston block attempts to push the fluid quickly, but the fluid's rate through the tube is limited, thus creating a damping force on the second piston block. This damping force provides a buffer for the rapid movement of the second piston block, assisting the first buffer assembly in absorbing the impact, effectively coping with sudden and severe loads, and preventing damage to the pump truck hydraulic cylinder piston rod due to severe impact when changing the direction of movement.

[0027] Beneficial effects: In this utility model, the reciprocating shock-absorbing piston rod end of the hydraulic cylinder of a pump truck, by symmetrically arranging springs on both sides of the first piston block, in conjunction with the limiting protrusions and rubber protrusions on the inner wall of the end sleeve, can achieve bidirectional buffering during the reciprocating motion of the piston rod; when the piston block moves and squeezes the rubber protrusions, its special inclined surface design generates progressive frictional resistance, which, together with the spring compression force, consumes the impact energy; this structure can provide stable and effective buffering for the reciprocating motion of the piston rod, greatly reducing the vibration when moving to the limit position, and improving the stability and accuracy of the pump truck operation;

[0028] In this invention, the second buffer assembly added to the reciprocating shock-absorbing piston rod end of the pump truck hydraulic cylinder drives the second piston block to move within the buffer chamber via a fixed rod, forcing the fluid to transfer through a slender connecting pipe. The slender pipe structure can limit the fluid flow rate and generate damping resistance under instantaneous impact. This hydraulic buffer mechanism, in synergy with the mechanical shock absorption of the first buffer assembly, significantly improves the absorption capacity for severe loads, effectively preventing damage to the pump truck hydraulic cylinder piston rod due to severe impact when changing its direction of movement, and extending the service life of the equipment.

[0029] In this utility model, the reciprocating shock-absorbing piston rod end of the pump truck hydraulic cylinder has a matching structure of limiting protrusion and piston block groove to ensure stable motion trajectory and prevent eccentric load wear; the buffer chamber is equipped with a removable sealing plug for easy periodic inspection or fluid replacement; the modular design of the mounting ring and fixing plate simplifies the assembly process of the end, piston rod body and external equipment, and reduces maintenance costs.

[0030] In this utility model, the reciprocating motion shock-absorbing piston rod end of the pump truck hydraulic cylinder has a dual buffer system that disperses the peak load during hydraulic cylinder reversal, reduces fatigue damage to connecting bolts, seals and support structures, reduces equipment downtime for maintenance, and improves the long-term reliability of the pump truck hydraulic system.

[0031] In this invention, the end cap absorbs conventional impacts through a bidirectional mechanical buffer structure (spring and inclined rubber convex strip working together), and combines a hydraulic damping system (thin tube flow limiting to form resistance) to cope with instantaneous severe loads; the dual shock absorption mechanism can reduce piston rod reversing vibration and improve working stability; the limiting slide groove prevents off-center load wear, and the modular design simplifies assembly; the overall structure can effectively disperse peak stress, reduce component fatigue damage, and extend the service life of the equipment. Attached Figure Description

[0032] Figure 1 This is a three-dimensional structural diagram of the end of the reciprocating shock-absorbing piston rod of a pump truck hydraulic cylinder proposed in this utility model.

[0033] Figure 2This is a cross-sectional structural schematic diagram of the end of the reciprocating shock-absorbing piston rod of a pump truck hydraulic cylinder proposed in this utility model.

[0034] Figure 3 This utility model provides a schematic diagram of the internal structure of the end sleeve of the reciprocating shock-absorbing piston rod of a pump truck hydraulic cylinder.

[0035] Figure 4 This utility model provides a schematic diagram of the limiting protrusion and rubber protrusion structure at the end of the reciprocating shock-absorbing piston rod of a pump truck hydraulic cylinder.

[0036] Figure 5 This invention provides a schematic diagram of the internal structure of the connecting rod at the end of the reciprocating shock-absorbing piston rod of a pump truck hydraulic cylinder.

[0037] In the diagram: 1. Piston rod body; 2. First fixing plate; 3. Second fixing plate; 4. Connecting rod; 5. End sleeve; 6. Mounting ring; 7. First piston block; 8. Fixing rod; 9. Second piston block; 10. Spring; 11. Limiting protrusion; 12. Mounting groove; 13. Rubber protrusion; 14. Limiting slide groove; 15. Buffer chamber; 16. Connecting thin tube; 17. Injection tube; 18. Sealing plug. Detailed Implementation

[0038] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0039] In one embodiment: Refer to Figure 1-5 A piston rod end comprises: an end sleeve 5, a mounting ring 6, a connecting rod 4, a first piston block 7, a first buffer assembly, and a second buffer assembly.

[0040] In this embodiment, the end sleeve 5 is cylindrical, and an end cap is fixedly installed at one end by bolts. The mounting ring 6 is fixedly installed at the end of the end sleeve 5 away from the end cap for movable connection with external equipment.

[0041] In this embodiment, the connecting rod 4 is a slender rod-shaped structure, with one end sliding through the end cap. The first piston block 7 is fixedly installed at one end of the connecting rod 4 near the inside of the end sleeve 5, and the first piston block 7 slides in cooperation with the inner wall of the end sleeve 5. The end sleeve 5, the connecting rod 4, and the first piston block 7 cooperate to form a movable end.

[0042] In this embodiment, the first buffer assembly is used to provide bidirectional buffering for the first piston block 7 inside the end sleeve 5. The first buffer assembly includes two springs 10 and multiple rubber protrusions 13. The two springs 10 are located at both ends of the first piston block 7, with one spring 10 sleeved on the outer wall of the connecting rod 4. One end of each spring 10 abuts against the adjacent first piston block 7 via a corresponding spring 10 seat, the other end of one spring 10 abuts against one side of the inner wall of the end sleeve 5 via a spring 10 seat, and the other end of the other spring 10 abuts against the end cap at one end of the end sleeve 5 via a spring 10 seat.

[0043] Furthermore, in this embodiment, four limiting protrusions 11 are fixedly installed on the inner wall of the end sleeve 5, and the four limiting protrusions 11 are evenly distributed circumferentially along the inner wall of the end sleeve 5. Each limiting protrusion 11 has an installation groove 12 on one side, and multiple rubber protrusions 13 are engaged and fixed in the corresponding installation groove 12. The outer wall of the first piston block 7 has four limiting sliding grooves 14, and the inner walls of the four limiting sliding grooves 14 are slidably connected to the outer walls of the corresponding limiting protrusions 11. Each side of the multiple rubber protrusions 13 is provided with two inclined surfaces, and each is designed to be concave in the middle and convex at both ends. When the first piston block 7 moves in the end sleeve 5, the inclined surfaces of the rubber protrusions 13 are pressed and slidably engaged with the inner walls of the corresponding limiting sliding grooves 14 to increase the friction force when the first piston block 7 moves towards both ends of the end sleeve 5, thereby further buffering the first piston block 7.

[0044] In this embodiment, the second buffer assembly is used in conjunction with the first buffer assembly to assist in the installation of the movable end. The second buffer assembly includes a fixing rod 8 disposed inside the end sleeve 5. One end of the fixing rod 8 passes through one end of the end sleeve 5 and one side of the mounting ring 6, and is fixedly connected to the mounting ring 6 by bolts. A buffer chamber 15 is formed inside the connecting rod 4. The other end of the fixing rod 8 passes through the first piston block 7 and one end of the connecting rod 4 in a sealed sliding manner and extends into the buffer chamber 15. A second piston block 9 is fixedly installed at the other end of the fixing rod 8, and the second piston block 9 is in a sealed sliding connection with the inner wall of the buffer chamber 15. The buffer chamber 15 is filled with a buffering fluid, which can be hydraulic oil or a mixture of nitrogen and hydraulic oil. A connecting tube 16 is formed inside the connecting rod 4, and both ends of the connecting tube 16 are connected to the interior of the buffer chamber 15. The second piston block 9 is located between the two ends of the connecting tube 16. When the second piston block 9 moves, it pushes the fluid in the buffer chamber 15 to move through the connecting capillary tube 16. The connecting capillary tube 16 restricts the transfer rate of the fluid and provides a buffer for the instantaneous force movement of the second piston block 9.

[0045] This application can be used in the field of concrete pump truck technology, or in other fields applicable to this application.

[0046] In another embodiment: Reference Figure 1 , 5 A shock-absorbing piston rod end for reciprocating motion of a pump truck hydraulic cylinder, which is applied to the field of concrete pump truck technology.

[0047] To facilitate the drainage and injection of fluid into the buffer chamber 15, in this embodiment, an injection tube 17 is provided inside the connecting rod 4. The injection tube 17 is connected to the end of the buffer chamber 15 away from the first piston block 7, and the other end of the injection tube 17 penetrates through the outer wall of the connecting rod 4. An internal threaded connector is fixedly installed on the outer wall of the connecting rod 4. The internal threaded connector corresponds to one end of the injection tube 17, and a sealing plug 18 is threaded onto the inner wall of the internal threaded connector. The injection tube 17 is opened and closed by opening or closing the sealing plug 18.

[0048] In this embodiment, a second fixing plate 3 is fixedly installed at the end of the connecting rod 4 away from the first piston block 7, and a first fixing plate 2 is fixedly installed at one end of the piston rod body 1. The second fixing plate 3 is fixedly connected to the first fixing plate 2 by bolts, thus completing the installation and fixing of the movable end on the piston rod body 1.

[0049] The working principle and usage process of this technical solution are as follows: During use, the entire end is fixedly connected to the first fixed plate 2 at one end of the piston rod body 1 via bolts through the second fixed plate 3 at one end of the connecting rod 4, thus completing the installation. The mounting ring 6 can be used for movable connection with external equipment.

[0050] When the piston rod body 1 drives the external device to its limit through the movable end, the motion is transmitted to the end sleeve 5. The movable end, which is composed of the end sleeve 5, the internal connecting rod 4, and the first piston block 7, has a relative motion tendency. At this time, the limiting protrusion 11 fixed to the inner wall of the end sleeve 5 slides along the limiting groove 14 on the outer wall of the first piston block 7.

[0051] When the first piston block 7 moves, it pushes the spring 10 on the corresponding side, which is compressible and absorbs energy. Simultaneously, the first piston block 7 slides along the limiting protrusion 11, causing the inclined surface of the rubber protrusion 13 within the limiting protrusion 11 to make compression contact with the inner wall of the limiting groove 14. The rubber protrusion 13 deforms under the compression of the first piston block 7, thereby increasing the sliding friction resistance of the first piston block 7. This friction resistance, combined with the compression resistance of the spring 10, provides a buffering effect on the movement of the first piston block 7 in the corresponding direction, thus providing cushioning for the entire movable end.

[0052] Meanwhile, the rubber convex strip 13, with its concave center and convex sides, combined with the springs 10 on both sides of the first piston block 7, can ensure bidirectional buffering of the first piston block 7, thus facilitating effective shock absorption of the pump truck hydraulic cylinder piston rod during reciprocating motion.

[0053] When the first piston block 7 moves, the fixed rod 8 can move relative to the connecting rod 4 and the first piston block 7. The fixed rod 8 can drive the second piston block 9 at one end to slide within the buffer chamber 15 inside the connecting rod 4. The back-and-forth movement of the second piston block 9 can push the fluid in the buffer chambers 15 on both sides, forcing the fluid to flow through the connecting tube 16 provided inside the connecting rod 4, flowing from one side of the second piston block 9 to the other. Due to the small diameter of the connecting tube 16, the speed of fluid transfer is limited; when the movable end is subjected to a sudden impact force and moves rapidly, the second piston block 9 attempts to push the fluid quickly, but the rate at which the fluid passes through the tube is limited, thus forming a damping force on the second piston block 9. This damping force provides a buffer for the rapid movement of the second piston block 9, assisting the first buffer assembly in absorbing the impact, effectively coping with sudden and severe loads, and preventing damage to the pump truck hydraulic cylinder piston rod due to severe impact when changing the direction of movement.

[0054] The accompanying drawings in this application are for illustrative purposes only. The dimensions and shapes of the components shown are not actual limitations but are merely schematic representations. In actual implementation, the components can be reasonably configured and adjusted according to specific needs and actual conditions.

[0055] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A shock-absorbing piston rod end for reciprocating motion of a pump truck hydraulic cylinder, characterized in that, include: End sleeve (5) and mounting ring (6), wherein the mounting ring (6) is fixed to one end of the end sleeve (5); The connecting rod (4) and the first piston block (7) are fixed to one end of the connecting rod (4). The first piston block (7) is axially slidingly engaged with the inner wall of the end sleeve (5). One end of the end sleeve (5) is fixed to the end cover by bolts. One end of the connecting rod (4) slides through the end cover. The first buffer assembly includes two springs (10) and a plurality of rubber protrusions (13), with the two springs (10) distributed axially on both sides of the first piston block (7); The second buffer assembly includes a fixing rod (8) fixed to the mounting ring (6), the other end of the fixing rod (8) being sealed and slidingly passing through the first piston block (7) and extending into the buffer chamber (15) opened inside the connecting rod (4), the end of the fixing rod (8) being fixed to the second piston block (9), the second piston block (9) being sealed and slidingly engaged with the buffer chamber (15), the buffer chamber (15) being filled with fluid and having a connecting tube (16), the two ends of the connecting tube (16) being connected to the buffer chamber (15), and the second piston block (9) being located between the two ends of the connecting tube (16); When the first piston block (7) moves, it compresses the spring (10) on one side and squeezes the rubber protrusion (13) to generate frictional resistance. At the same time, the second piston block (9) pushes the fluid through the connecting thin tube (16) to form damping.

2. The reciprocating shock-absorbing piston rod end of the pump truck hydraulic cylinder according to claim 1, characterized in that, Both springs (10) are located inside the end sleeve (5), and one of the springs (10) is sleeved on the outer wall of the connecting rod (4). One end of the two springs (10) abuts against the first piston block (7), and the other end abuts against the inner wall of the end sleeve (5) and one side of the adjacent end cap, respectively.

3. The reciprocating shock-absorbing piston rod end of the pump truck hydraulic cylinder according to claim 1, characterized in that, The first buffer assembly also includes four limiting protrusions (11) fixed to the inner wall of the end sleeve (5). The four limiting protrusions (11) are evenly distributed circumferentially, and each limiting protrusion (11) has an installation groove (12). Multiple rubber protrusions (13) are fixed in the corresponding installation groove (12).

4. The reciprocating shock-absorbing piston rod end of the pump truck hydraulic cylinder according to claim 3, characterized in that, The outer wall of the first piston block (7) has four limiting grooves (14), and the inner walls of the four limiting grooves (14) are slidably connected to the outer walls of the corresponding limiting protrusions (11).

5. The reciprocating shock-absorbing piston rod end of the pump truck hydraulic cylinder according to claim 4, characterized in that, Each of the rubber protrusions (13) has two inclined surfaces on one side and is concave in the middle and convex at both ends. When the first piston block (7) moves, the inclined surfaces are squeezed and slid against the inner wall of the corresponding limiting groove (14) to generate progressive frictional resistance.

6. The reciprocating shock-absorbing piston rod end of the pump truck hydraulic cylinder according to claim 1, characterized in that, The diameter of the connecting tube (16) is much smaller than the radial dimension of the buffer chamber (15).

7. The reciprocating shock-absorbing piston rod end of the pump truck hydraulic cylinder according to claim 1, characterized in that, The connecting rod (4) has an injection tube (17) inside. The injection tube (17) is connected to the end of the buffer chamber (15) away from the first piston block (7), and the outlet of the injection tube (17) passes through the outer wall of the connecting rod (4).

8. The reciprocating shock-absorbing piston rod end of the pump truck hydraulic cylinder according to claim 7, characterized in that, The connecting rod (4) is fixed to the outer wall with an internal threaded connector, which corresponds to the outlet of the injection pipe (17) and is connected to the threaded sealing plug (18).

9. The reciprocating shock-absorbing piston rod end of the pump truck hydraulic cylinder according to claim 1, characterized in that, The end of the connecting rod (4) away from the first piston block (7) is fixed to the second fixing plate (3), and the second fixing plate (3) is fixedly connected to the first fixing plate (2) at the end of the piston rod body (1) by bolts.

Images