Leveling leg oil cylinder mechanism, leveling leg oil cylinder hydraulic unit, and engineering machine

Abstract

The application discloses a leveling outrigger oil cylinder mechanism, a hydraulic unit and engineering machinery, which comprises a leveling outrigger oil cylinder and a connecting block formed with a spherical groove, the extending end of the piston rod of the leveling outrigger oil cylinder is provided with a ball head, the diameter of the ball head is larger than that of the piston rod, the ball head is installed and matched into the spherical groove and has a convex spherical part, the connecting block is connected with a limiting cover plate, the limiting cover plate is provided with a concave spherical hole matched with the convex spherical part, so that the concave spherical hole on the limiting cover plate is matched with the spherical surface of the convex spherical part and connects and limits the ball head. The special structure cooperation among the ball head, the connecting block and the limiting cover plate makes the leveling outrigger oil cylinder mechanism capable of bearing pressure and tension, and the installation mode and sequence are improved, the installation work is effectively simplified, and the installation is more convenient and easy.

Description

Technical Field

[0001] This invention relates to a hydraulic actuator, specifically, to a leveling outrigger cylinder mechanism. Furthermore, this invention also relates to a leveling outrigger cylinder hydraulic unit and engineering machinery. Background Technology

[0002] Construction machinery is often used on rough and uneven roads, and its working mechanism often has a certain working height, such as concrete pump trucks and truck cranes. Uneven roads can cause the center of gravity of construction machinery to shift, which can easily lead to operational accidents due to instability.

[0003] Typically, for example, in tower cranes, the jib is mounted at the top of the tower. If the base support structure becomes tilted due to uneven ground, it could lead to serious operational accidents. Therefore, tower cranes generally require a leveling mechanism to adjust the level of the tower crane base. However, given the current state of tower crane technology, while stationary tower cranes have some existing leveling mechanisms, mobile tower cranes, due to their unfixed base and less mature technology, have higher requirements for ground slope (flatness), and currently lack leveling mechanisms specifically designed for ground slope (flatness).

[0004] The existing leveling mechanisms mainly adopt leveling outrigger mechanisms, which are mainly divided into mechanical outriggers and hydraulic cylinders. Among them, hydraulic leveling outriggers are easy to adjust and are widely used in tower cranes in the wind power hoisting field that require frequent assembly and disassembly. The following describes the technical overview of existing leveling outriggers using tower crane applications as an example.

[0005] Figure 1 This diagram shows a tower crane using leveling outrigger cylinders. One leveling outrigger cylinder 3a is installed at each of the four corners of the base frame 2a of tower crane 1a. The hydraulic control circuit drives the extension of the leveling outrigger cylinders 3a, adjusting their height to compensate for ground unevenness. Under normal circumstances, the leveling outrigger cylinders 3a bear the pressure of the upper load, such as the tower body. The pressure on the leveling outrigger cylinders 3a changes when the tower crane 1a is in different lifting positions. During adjustment, due to the huge load on the upper part of the tower crane, a corresponding load-bearing mechanism is generally required to prevent pressure fluctuations in the hydraulic system from damaging the cylinders. After the height of the leveling outrigger cylinders 3a is adjusted, the load-bearing mechanism provides stable and reliable load support.

[0006] See Figure 2 As shown, Figure 2The existing self-locking hydraulic jack cylinder structure is shown, which mainly includes a saddle 1b, a screw 2b, a piston rod 3b, a self-locking nut 4b, and a cylinder body 5b. The end face groove of the saddle 1b and the piston rod 3b are spherically fitted. The deflection angle between the saddle 1b and the piston rod 3b is limited by the gap between the screw 2b and the saddle 1b. This spherical fit allows for a certain angle of deflection adjustment, mainly to accommodate possible slippage or pressure direction changes of the lifted load, and to prevent damage to the cylinder.

[0007] Construction machinery, such as tower cranes, often uses leveling outrigger cylinders with a structure similar to the self-locking hydraulic jack cylinders mentioned above. (See [link to relevant documentation]). Figure 3 As shown, the leveling outrigger cylinder includes a piston rod 3c, a cylinder body 5c, a self-locking nut 4c, a connecting block 1c, and a screw 2c. The piston rod 3c has a hemispherical or partially spherical head (referred to as a hemispherical head) with a threaded hole in the center. The screw 2c is installed on the connecting block 1c and the hemispherical head, with a gap between the screw 2c and the connecting block 1c. During operation, this gap limits the deflection angle between the connecting block 1c and the hemispherical head to approximately 5°. The connecting block 1c is bolted to the base frame of the tower crane, and the base plate of the cylinder body 5c is bolted to the ground foundation structure. The piston rod 3c has threads on its upper part. When the ground is uneven and the leveling outrigger cylinder is needed for height adjustment, the high-pressure oil from the pump station pushes the piston rod 3c out, and the operator simultaneously manually operates the self-locking nut 4c to make it fit tightly against the upper end of the cylinder body 5c.

[0008] The above Figure 3 The hydraulic cylinders for leveling outriggers shown are widely used on wind turbine tower cranes that require frequent assembly and disassembly. Compared to mechanical leveling outriggers, these hydraulic cylinders offer the advantage of convenient adjustment, but they also have several drawbacks, particularly making them unsuitable for mobile construction machinery with high ground slope requirements, such as mobile tower cranes.

[0009] Firstly, in this type of leveling outrigger cylinder, only one screw 2c is installed between the piston rod 3c and the connecting block 1c to limit the angle. This single screw requires a certain clearance for positioning (i.e., the screw is not tightened), which means the leveling outrigger cylinder can only withstand a very small tensile force (limited by the load-bearing capacity of this single screw 2c). When a large tensile force occurs on the leveling outrigger cylinder, the central screw 2c will break and fail. This type of leveling outrigger cylinder is not suitable for applications with large tensile forces. Mobile construction machinery, due to its need for small movements on construction sites and the frequent occurrence of large tensile forces on uneven surfaces, is particularly unsuitable for mobile construction machinery, such as mobile tower cranes.

[0010] Second, for the leveling outrigger cylinder of this structure, under load conditions, the outward extension adjustment with load is relatively easy, while the inward retraction adjustment is very difficult and dangerous. The main reason is as follows: when the piston rod 3c retracts under load, it requires oil to enter the rod chamber of the leveling outrigger cylinder, and the oil returns from the rodless chamber. Once the oil returns from the rodless chamber, it means the rodless chamber is communicated with the oil return circuit connected to the oil tank. Since the weight of the tower crane carried on the upper part of the piston rod 3c is huge, it is prone to stall, leading to operational accidents. This adjustment characteristic of the leveling outrigger cylinder is basically inapplicable to mobile construction machinery such as mobile tower cranes. Due to the undulation of the ground, the height below the four leveling outrigger cylinders varies with the ground conditions. If only one-way extension adjustment is performed to ensure safety, it is very likely that the upward stroke will be exhausted and the adjustment function will no longer be available. Therefore, this structural form of leveling outrigger cylinder is even less applicable in situations where two-way safe adjustment of the leveling outrigger cylinder is required.

[0011] Third, when assembling this leveling outrigger cylinder with the tower crane, it is necessary to assemble the connecting block 1c with the piston rod 3c first, and install the limiting screw 2c. Then, the bolts between the connecting block 1c and the tower crane undercarriage are installed one by one. Due to the large size of the tower crane undercarriage, certain elastic deformation is inevitable during processing, transportation and installation. Since there are a large number of bolt holes that need to be aligned between the connecting block 1c of the four outrigger cylinders and the undercarriage, installation is very difficult, and the installation work is relatively difficult and inconvenient.

[0012] Among the above-mentioned defects in the prior art, the more intractable defect that constitutes a bottleneck for the development of mobile construction machinery leveling technology is the first technical defect in terms of structure. In structural design, in view of the walking characteristics of mobile construction machinery that need to adapt to road conditions, it is difficult to design a relatively movable connection with a certain angle between the leveling outrigger cylinder and the load, which can withstand both tension and pressure. This requires the cooperative design of the movable connection structure, the limiting structure, the installation structure and other structures at the same time. Only on the basis that the structural design can adapt to the walking characteristics of mobile construction machinery can the layout design of hydraulic elements matched with the leveling outrigger cylinder have application significance.

[0013] In view of this, it is necessary to design a new type of leveling outrigger cylinder mechanism. Summary of the Invention

[0014] The primary technical problem to be solved by the present invention is to provide a leveling outrigger cylinder mechanism, which can effectively adapt to the walking characteristics of mobile construction machinery, can withstand both pressure and tension, and is reliable and convenient to install.

[0015] A further technical problem to be solved by the present invention is to provide a leveling outrigger cylinder mechanism, which can effectively adapt to the walking characteristics of mobile construction machinery. The mechanism not only allows the leveling outrigger cylinder to perform activity adjustment within a certain deflection angle relative to the load, but also can withstand pressure and tension, and is reliable and convenient to install.

[0016] Furthermore, the technical problem to be solved by the present invention is to provide a hydraulic unit for adjusting outrigger cylinders, which not only has the advantages of the above-mentioned adjusting outrigger cylinder mechanism, but also can safely and reliably perform bidirectional load leveling operations.

[0017] Furthermore, the technical problem to be solved by the present invention is to provide an engineering machine whose bottom leveling device allows the leveling outrigger cylinder to be adjusted to a certain deflection angle relative to the load, can withstand pressure and tension, is reliable and convenient to install, and can safely and reliably perform bidirectional load leveling operation.

[0018] To solve the above-mentioned technical problems, the present invention provides a leveling outrigger cylinder mechanism, including a leveling outrigger cylinder and a connecting block. The connecting block has a spherical groove. The extended end of the piston rod of the leveling outrigger cylinder has an integrally formed ball head, or is mounted thereon via a tension bearing structure. The diameter of the ball head is larger than the diameter of the piston rod. The ball head is fitted into the spherical groove and has a protruding spherical portion extending beyond the groove. A limiting cover plate is fixed to the connecting block. The limiting cover plate has a concave spherical hole that mates with the protruding spherical portion, so that the concave spherical hole and the spherical surface of the protruding spherical portion mate and connect, limiting the ball head.

[0019] Preferably, the ball head is mounted to the piston rod end via the tension bearing structure, wherein the tension bearing structure includes pre-tightening connecting screws, a plurality of screw mounting holes formed on the ball head and penetrating the bottom plane of the ball head, and a plurality of threaded holes formed on the end face of the piston rod, wherein the bottom plane of the ball head fits against the end face of the piston rod, and the plurality of pre-tightening connecting screws are each mounted into the plurality of threaded holes via the plurality of screw mounting holes and pre-tightened.

[0020] More preferably, the plurality of screw mounting holes are evenly distributed circumferentially on the bottom plane of the ball head, and the plurality of threaded holes are evenly distributed circumferentially on the end face of the piston rod.

[0021] Specifically, the connecting block is provided with multiple load bolt mounting holes for connecting the upper load; and the limiting cover plate is fixed to the connecting block by connecting bolts.

[0022] Particularly preferably, the volume of the sphere of the ball head exceeds the volume of a hemisphere.

[0023] Preferably, the piston rod has an external threaded section, on which a self-locking nut is installed. The self-locking nut is located outside the cylinder head of the leveling outrigger cylinder, and the rotation achieved through the threaded engagement can be made to abut against the cylinder head to achieve self-locking of the piston rod.

[0024] As a preferred technical solution, the limiting cover plate has a limiting structure for limiting the deflection angle of the ball head (2).

[0025] More preferably, the concave spherical hole on the limiting cover includes a spherical section that mates with the protruding spherical portion and a perforated section into which the piston rod extends. The perforated section is formed as a conical hole section and has a gap with the outer peripheral surface of the piston rod to serve as the limiting structure.

[0026] More preferably, the perforated section is formed as a conical hole section, and the gap between the conical hole section and the outer peripheral surface of the piston rod limits the deflection angle θ of the ball head to 2° to 6°.

[0027] Based on the above-mentioned technical solutions for the leveling outrigger cylinder mechanism, the present invention provides a hydraulic unit for the leveling outrigger cylinder, which includes the leveling outrigger cylinder mechanism of any of the above technical solutions. The rodless chamber oil port of the leveling outrigger cylinder is connected to a first internal working oil circuit with a rodless chamber oil port connected to a rod chamber oil port connected to a second internal working oil circuit with a rod chamber oil port connected to a rod chamber oil circuit. The external feedback port of the rodless chamber balance valve is connected to the second internal working oil circuit via a first feedback oil circuit, and the external feedback port of the rod chamber balance valve is connected to the first internal working oil circuit via a second feedback oil circuit.

[0028] Preferably, both the rodless chamber balance valve and the rod chamber balance valve are disposed on the side wall of the cylinder body of the leveling outrigger cylinder, and the first internal working oil circuit, the second internal working oil circuit, the first feedback oil circuit and the second feedback oil circuit are formed through the internal oil passage in the side wall of the cylinder body and / or the hydraulic pipeline outside the cylinder body.

[0029] More preferably, the second internal working oil circuit is also connected to a pressure replenishing unit, and the connection is such that the rod chamber balance valve is located between the rod chamber port and the pressure replenishing unit in the second internal working oil circuit.

[0030] Alternatively, the pressure replenishment unit includes an accumulator, an on / off switch valve, a replenishment check valve, and a pressure replenishment oil source, wherein the reverse port of the replenishment check valve is connected to the second internal working oil circuit, and the forward port is connected to the pressure replenishment oil source, and the accumulator is connected between the replenishment check valve and the pressure replenishment oil source via the on / off switch valve.

[0031] In addition, the present invention also provides an engineering machine, which includes the hydraulic unit of the leveling outrigger cylinder described in any of the above embodiments, wherein the first internal working oil circuit and the second internal working oil circuit are connected to the extension and reversing control oil circuit of the leveling outrigger cylinder.

[0032] Typically, the telescopic reversing control oil circuit includes a reversing switching valve, the first working oil port and the second working oil port of which are respectively connected to the first internal working oil circuit and the second internal working oil circuit fluid circuit, and the oil inlet and the oil return port are respectively connected to the main oil inlet oil circuit and the oil return oil circuit.

[0033] As a practical alternative, the construction machinery is a tracked tower crane, wherein the connecting block is fixed to the base frame of the tracked tower crane, and the bottom of the cylinder of the leveling outrigger cylinder is fixed to the chassis frame of the tracked tower crane.

[0034] The advantages of this invention through the above technical solution are as follows:

[0035] First, regarding the basic implementation of the leveling outrigger cylinder mechanism of the present invention, its unique mechanical load-bearing structure design, through the specific structural cooperation between the ball head, connecting block, and limiting cover plate, ensures uniform force distribution and load transmission, enabling the leveling outrigger cylinder mechanism to withstand both pressure and tension. From a mechanical structure perspective, this ensures that the leveling outrigger cylinder can effectively adapt to the walking characteristics of mobile engineering machinery. At the same time, this unique mechanical structure design improves the installation method and installation sequence, effectively simplifies the installation work, and makes installation more convenient and easier.

[0036] Secondly, in the preferred embodiment of the leveling outrigger cylinder mechanism of the present invention, the present invention ingeniously uses the structural cooperation between the limiting cover plate and the piston rod to limit the deflection angle by the gap between the limiting cover plate and the piston rod. In practical applications, this can ensure the safety and reliability of mobile engineering machinery and simplify the structure.

[0037] Third, in the hydraulic unit of the leveling outrigger cylinder of the present invention, the innovative design of the dual balance valve (i.e., rod chamber balance valve and rodless chamber balance valve) makes the working oil circuits of the two valves mutually external oil pressure feedback circuits, effectively limiting the return oil speed of extension and retraction, and dynamically adjusting the dynamic pressure balance and return oil flow opening, ensuring that the piston rod can extend and retract smoothly and safely under load conditions, effectively realizing bidirectional load leveling operation.

[0038] Fourth, and most importantly, in the preferred embodiment of the present invention, the present invention can withstand the instantaneous tensile force generated in sudden situations. Through the original design of the pressure-replenishing oil source, it cleverly utilizes the pressure difference formed by the lack of oil in the rod chamber to replenish the hydraulic oil in the rod chamber at all times, thus preparing in advance to withstand the instantaneous tensile force. In this way, even if the leveling outrigger cylinder is subjected to instantaneous tensile force due to bumpy road conditions during the operation of the mobile engineering machinery, the sufficient oil in the rod chamber can instantly resist the tensile force, ensuring the stability of the piston rod position and effectively preventing the piston rod from becoming displaced and affecting the original leveling effect.

[0039] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0040] The following figures are provided to further illustrate the invention and form part of the specification. They, together with the detailed embodiments described below, serve to explain the invention, but the scope of protection of the invention is not limited to the following figures and detailed embodiments. In the figures:

[0041] Figure 1 This is a structural diagram of a tower crane using leveling outrigger cylinders in the existing technology;

[0042] Figure 2 This is a structural schematic diagram of a self-locking hydraulic jack cylinder in the prior art;

[0043] Figure 3 This is a schematic diagram of the structure of the leveling support leg cylinder in the prior art;

[0044] Figure 4 This is a schematic diagram of the leveling support leg cylinder according to a specific embodiment of the present invention;

[0045] Figure 5 This is a hydraulic schematic diagram of the hydraulic circuit of the leveling outrigger cylinder in a specific embodiment of the present invention.

[0046] Figure 6 yes Figure 5 The hydraulic circuit diagram shown above uses an accumulator as a low-pressure oil replenishment device in the hydraulic circuit of the leveling outrigger cylinder; and

[0047] Figure 7 yes Figure 6 The diagram shown is a schematic of the hydraulic extension control circuit of the leveling outrigger cylinder hydraulic unit when applied to construction machinery, which includes an extension and reversing control unit for the leveling outrigger cylinder.

[0048] Explanation of reference numerals in the accompanying drawings of this invention:

[0049] 1. Connecting block; 2. Ball head;

[0050] 3. Pre-tightening connecting screws; 4. Limiting cover plate;

[0051] 5. Connecting bolts; 6. Piston rod;

[0052] 7. Self-locking nut; 8. Cylinder block;

[0053] 9. Rod-type chamber balance valve; 9a. External feedback port of the rod-type chamber balance valve;

[0054] 10 rodless chamber balance valve; 10a external feedback port of rodless chamber balance valve;

[0055] 11. Spherical groove; 12. Protruding spherical part;

[0056] 13. Concave spherical face; 14. Limiting structure;

[0057] 15 Support block; 16 Pressure replenishment unit;

[0058] 16a Accumulator; 16b On / off switch valve;

[0059] 16c oil replenishment check valve; 16d pressure replenishment oil source;

[0060] 17 Second feedback oil circuit; 18 First feedback oil circuit;

[0061] 19 First internal working oil passage; 20 Second internal working oil passage;

[0062] 21 Second internal working oil circuit connection port; 22 First internal working oil circuit connection port;

[0063] 23 Second working oil circuit; 24 First working oil circuit;

[0064] 25 Telescopic reversing control oil circuit; 25a Reversing switching valve;

[0065] 25b Main oil pump; 25c Oil tank. Detailed Implementation

[0066] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for illustration and explanation of the present invention, and the scope of protection of the present invention is not limited to the specific embodiments described below.

[0067] It should be noted beforehand that the directional terms used in the following descriptions of the various embodiments of the present invention refer to the normal operating orientation of the leveling outrigger cylinder. In normal use, the outrigger leveling cylinder is generally arranged vertically, with the piston rod at the top and the cylinder body at the bottom. Therefore, directional terms used below, such as "bottom," "bottom plane," and "top," are distinguished and defined according to the normal operating orientation of the leveling outrigger cylinder. As long as it is in that orientation in its normal operating installation state, any other orientation that may occur due to different placement during sales or transportation should be considered to have the directional meaning defined by the present invention and fall within the protection scope of the present invention.

[0068] See Figure 4As shown, the leveling outrigger cylinder mechanism of the basic embodiment of the present invention mainly includes a leveling outrigger cylinder and a connecting block 1. A spherical groove 11 can be formed on the connecting block 1. The extended end of the piston rod 6 of the leveling outrigger cylinder is integrally formed with or installed with a ball head 2 through a tension bearing structure. The diameter of the ball head 2 is larger than the diameter of the piston rod 6. The ball head 2 is installed and fitted into the spherical groove 11, and the lower part protrudes out of the spherical groove 11 as a protruding spherical portion 12. A limiting cover plate 4 is fixed on the connecting block 1. The limiting cover plate 4 has a concave spherical hole 13 that mates with the protruding spherical portion 12. The limiting cover plate 4 is fixed to the connecting block 1 to form a concave spherical hole 13 that mates with the spherical surface of the protruding spherical portion 12 and connects the limiting ball head 2. In this basic embodiment, the ball head 2 and the piston rod 6 can be two independent components connected by a tension bearing structure, or they can be formed as an integral structure. In the case of forming an integral structure, its stress (especially its tensile strength) is better.

[0069] In the basic implementation of the leveling outrigger cylinder mechanism described above, due to its unique mechanical load-bearing structure design, the specific spherical mating structure and connection structure between the ball head 2, connecting block 1, and limiting cover plate 4 make the force more uniform and the load transmission and distribution more dispersed, ensuring that the leveling outrigger cylinder mechanism can withstand both pressure and tension. From a mechanical structure perspective, this ensures that the leveling outrigger cylinder can effectively adapt to the walking characteristics of mobile engineering machinery. At the same time, this unique mechanical structure design allows the connecting block 1 to be fixed to the base frame of the tower crane first. During installation, the leveling outrigger cylinder with the ball head 2 can be directly installed onto the connecting block 1 through the limiting cover plate 4. This improves the installation method and installation sequence, effectively simplifies the installation work, and makes installation more convenient and easier.

[0070] Based on the above-described basic embodiment of the leveling outrigger cylinder mechanism of the present invention, for ease of manufacturing, the ball head 2 and the piston rod 6 can be two independent components. Preferably, the volume of the ball head 2 exceeds the volume of a hemisphere, that is, a portion of a complete sphere is cut off at the bottom to form the bottom plane of the ball head 2. In this preferred structural form of the ball head 2, see [reference needed]. Figure 4 After the limiting cover plate 2 is connected and fixed to the connecting block 1, the spherical surface of the concave spherical hole 13 of the limiting cover plate 4 can effectively support the spherical surface of the protruding spherical part 12, so that the ball head 2 is subjected to more even force when under tension. Of course, the volume of the ball head 2 can also be smaller than the volume of a hemisphere. In this case, a stop structure similar to an inward flange needs to be designed at the lower end of the concave spherical hole 13 of the limiting cover plate 4. When the piston rod 6 is under tension, this stop structure stops each other with the bottom plane of the ball head 2, preventing the connecting block 1 and the limiting cover plate 4 from directly detaching from the ball head 2.

[0071] In this case, the ball head 2 can be installed to the end of the piston rod 6 through the aforementioned tension-bearing structure. Inspired by the structural design of the above-described basic embodiment of the present invention, using the ball head 2, connecting block 1, and limiting cover plate 4 as the structural basis, various specific structures can be conceived. For example, the bottom plane of the ball head 2 can form a horizontally penetrating dovetail groove or a rectangular groove with inwardly turned edges. The protruding end of the piston rod 6 is formed into a mating shape. During installation, it slides into the dovetail groove or rectangular groove from one end and is fixed via connecting screws through the screw mounting holes on the ball head 2 and the threaded holes on the protruding end face of the piston rod 6, preventing it from sliding out from either end of the horizontal dovetail groove or rectangular groove. This connection method can effectively withstand tensile and compressive forces.

[0072] See Figure 4 As a preferred structural form, for ease of processing and installation, the aforementioned tensile load-bearing structure may include pre-tightening connecting screws 3, multiple screw mounting holes formed on the ball head 2 and penetrating the bottom plane of the ball head 2, and multiple threaded holes formed on the end face of the piston rod 6. The bottom plane of the ball head 2 is in contact with the end face of the piston rod 6, and the multiple pre-tightening connecting screws 3 are each installed into the multiple threaded holes via the multiple screw mounting holes and pre-tightened. In this connection method using multiple pre-tightening connecting screws 3, since the deflection angle of the ball head 2 is limited not by the pre-tightening connecting screws, but by the limiting structure on the limiting cover plate 4, the pre-tightening connecting screws 3 primarily serve the function of pre-tightening connection and fastening. The connection of multiple pre-tightening connecting screws 3 and the application of pre-tightening force for fastening not only facilitates processing and installation, but also, through the auxiliary connection of the limiting cover plate 4, effectively disperses the tensile load, resulting in more uniform stress distribution. In actual tests, some models of the present invention can withstand tensile forces up to 1200 tons.

[0073] Furthermore, in order to make the force transmission between the ball head 2 and the piston rod 6 more uniform, more preferably, the plurality of screw mounting holes are evenly distributed in the circumferential direction on the bottom plane of the ball head 2, and the plurality of threaded holes are evenly distributed in the circumferential direction on the end face of the extended end of the piston rod 6.

[0074] As described above, in the structural design of the leveling outrigger cylinder mechanism of the present invention, the connecting block 1 can be pre-connected to the upper load of the engineering machinery, such as the tower crane base frame, so as to facilitate subsequent installation work. Specifically, the connecting block 1 can be provided with multiple load bolt mounting holes for connecting the upper load; and the limiting cover plate 4 can also be fixed to the connecting block 1 by connecting bolts 5.

[0075] See Figure 4As a preferred structural configuration, the piston rod 6 can have an external threaded section, on which a self-locking nut 7 is installed. This self-locking nut 7 is located outside the cylinder head of the leveling outrigger cylinder, and its rotation, achieved through the threaded engagement, allows it to abut against the cylinder head, thus achieving self-locking of the piston rod 6. This self-locking is essentially a mechanical tightening of the piston rod 6 by the self-locking nut, preventing the piston rod 6 from retracting due to fluctuations in system oil pressure, which would affect the load-bearing capacity of the upper part. Specifically, it prevents the upper load from forcibly pressing the piston rod 6 back if it fails to support itself due to unforeseen circumstances. Ultimately, the self-locking nut 7 and the cylinder body 8 provide mechanical pressure resistance, avoiding damage to the cylinder. The locking and unlocking actions by rotating the self-locking nut can be performed manually or driven by a mechanical device. During actual extension adjustment, the piston rod 6 extends outward. After extension, the self-locking nut 7 can be manually rotated to lower it to abut against the cylinder head of the leveling outrigger cylinder, or the self-locking nut can be simultaneously driven downward by a drive device during the piston rod 6 extension and leveling operation. When the piston rod 6 retracts and returns to its original position, the self-locking nut 7 can be manually rotated upwards to prevent it from obstructing the retraction of the piston rod 6. In the case of a drive device, the self-locking nut 7 can also be rotated upwards synchronously with the piston rod 6 retracting.

[0076] To ensure the safety of deflection, preferably, the limiting cover plate 4 has a limiting structure 14 for limiting the deflection angle of the ball head 2.

[0077] Regarding the aforementioned limiting structure for restricting the deflection angle of the ball head 2, preferably, see [reference needed]. Figure 4 The concave spherical hole 13 on the limiting cover plate 4 includes a spherical section that mates with the protruding spherical portion 12 of the ball head and a perforated section into which the piston rod 6 extends. This perforated section has a gap with the outer circumferential surface of the piston rod (6) to serve as the limiting structure. The function of this gap is that when the piston rod 6 deflects around the ball head 2, at a certain deflection level, the outer circumferential surface of the piston rod 6 will contact the lower edge of the perforated section, thereby limiting the deflection angle. Preferably, the perforated section can be formed as a conical hole, and the gap between this conical hole and the outer circumferential surface of the piston rod 6 limits the deflection angle θ of the ball head 2 to 2° to 6°. In actual testing, the size of the gap is determined according to the following principle: when the connecting block 1 and the limiting cover plate 4 deflect around the ball head 2 at a specified angle (e.g., typically 5°), the edge of the limiting cover plate 4 contacts the outer circumferential surface of the piston rod 6, thereby limiting the deflection angle. This deflection angle limiting structure is limited by the gap between the limiting cover plate 4 and the piston rod 6, requiring no additional structure. It is safe, reliable, and simplifies the assembly process.

[0078] Based on the above-described embodiments of the leveling outrigger cylinder of the present invention, in order to enable the leveling outrigger cylinder to be adjusted smoothly and safely in both directions, the present invention provides a hydraulic unit for the leveling outrigger cylinder, which includes the leveling outrigger cylinder mechanism of any of the above technical solutions. A rodless chamber balance valve 10 is provided on the first internal working oil circuit 19 connected to the rodless chamber oil port of the leveling outrigger cylinder, and a rod chamber balance valve 9 is provided on the second internal working oil circuit 20 connected to the rod chamber oil port. The external feedback port 10a of the rodless chamber balance valve 10 is connected to the second internal working oil circuit 20 via the first feedback oil circuit 18, and the external feedback port 9a of the rod chamber balance valve 9 is connected to the first internal working oil circuit 19 via the second feedback oil circuit 17.

[0079] See Figure 4 As shown, in a specific physical structural arrangement, both the rodless chamber balance valve 10 and the rod chamber balance valve 9 can be installed on the side wall of the cylinder body 8, and the first internal working oil passage 19, the second internal working oil passage 20, the first feedback oil passage 18, and the second feedback oil passage 17 are formed through internal oil passages within the side wall of the cylinder body 8 and / or hydraulic pipes outside the cylinder body 8. In this structural configuration, the rodless chamber balance valve 10 and the rod chamber balance valve 9 can actually constitute the components of the leveling outrigger cylinder described above, and can be manufactured and sold as a single unit, resulting in a more compact and simpler structure.

[0080] Here, a distinction regarding a technical concept in the hydraulic field also needs to be clarified beforehand: See [link to relevant documentation]. Figure 6 and Figure 7 As shown, in the field of hydraulics, although different parts are divided in the hydraulic schematic diagram for ease of description, for example in Figure 7 The first internal working oil passage 19 is connected to the first working oil passage 24 through the first internal working oil passage connection port 22, and the second internal working oil passage 20 is connected to the second working oil passage 23 through the second internal working oil passage connection port 21. However, in the actual hydraulic circuit structure, the first internal working oil passage connection port 22 and the second internal working oil passage connection port 21 can be a vague concept. In the physical structure, the first internal working oil passage 19 and the first working oil passage 24, and the second internal working oil passage 20 may be a single hydraulic pipeline, and the second internal working oil passage 20 and the second working oil passage 23 may also be a single hydraulic pipeline. In this case, the first internal working oil passage connection port 22 and the second internal working oil passage connection port 21 can simply represent a dividing point on the overall hydraulic pipeline. Of course, these oil passages and ports can also form a physical hardware structure. No matter how their specific implementation changes, as long as they form the actual hydraulic connection relationship of this invention, they should all fall within the protection scope of this invention.

[0081] In the basic implementation of setting up the rodless chamber balance valve 10 and the rod chamber balance valve, the function of the rodless chamber balance valve 10 is as follows: when the outrigger cylinder needs to perform a load-bearing retraction action, the rod chamber of the outrigger cylinder receives oil, and the rodless chamber returns oil. In order to avoid the upper load of the tower crane on the piston rod 6 being too large, causing the piston rod 6 to stall and causing danger, the rodless chamber balance valve 10 limits the return oil speed of the rodless chamber and performs dynamic pressure balance regulation. The external feedback port 10a of the rodless chamber balance valve 10 introduces the pressure on the second internal working oil circuit 20, which drives the rodless chamber balance valve 10 to open. When the return oil in the rodless chamber is too fast or too slow, the valve core is dynamically adjusted so that the flow opening of the rodless chamber balance valve 10 is adaptively adjusted, thereby making the load-bearing retraction regulation action smooth, safe and reliable. Furthermore, a rod chamber balance valve 9 is installed at the oil outlet of the rod chamber. The function of the rod chamber balance valve 9 is as follows: First, when the leveling outrigger cylinder bears the tension of the tower crane, the piston rod 6 tends to extend upwards. At this time, the hydraulic pressure in the rodless chamber is very small, and the oil pressure introduced into the first internal working oil circuit 19 by the external feedback port 9a of the rod chamber balance valve 9 is insufficient to open the rod chamber balance valve 9. The rod chamber balance valve 9 seals the oil in the rod chamber, so that the piston rod 6 of the leveling outrigger cylinder can bear the tension without significant displacement. This makes the entire leveling outrigger cylinder hydraulic pressure... The stability of the pressure unit is better; secondly, the rod chamber balance valve 9 can also make the extension adjustment operation of the leveling outrigger cylinder smoother. Specifically, when the leveling outrigger cylinder extends under load, oil enters the rodless chamber and oil returns from the rod chamber. The external feedback port 9a of the rod chamber balance valve 9 introduces the oil pressure from the first internal working oil circuit 19 (at this time the oil pressure is relatively large). The rod chamber balance valve 9 is driven by the introduced oil pressure to adaptively and dynamically adjust the flow opening and adaptively limit the oil return speed of the rod chamber, making the extension adjustment of the piston rod 6 smoother and safer.

[0082] To ensure that the hydraulic unit of the outrigger cylinder adapts to the walking characteristics of mobile construction machinery and can effectively withstand instantaneous tensile forces, preferably, a pressure replenishing unit can be connected to the rear of the rod chamber balance valve 9. That is, the second internal working oil circuit 20 is also connected to the pressure replenishing unit 16, with the rod chamber balance valve 9 positioned between the rod chamber port and the pressure replenishing unit 16 in the second internal working oil circuit 20. The function of this pressure replenishing unit is to maintain a sufficient supply of low-pressure oil in the rod chamber at all times. When a sudden situation requires the outrigger cylinder to withstand tensile forces, the rod chamber can quickly build up pressure to bear the tensile force. Specifically, the pressure replenishment unit 16 may include an accumulator 16a, an on / off switch valve 16b, a replenishment check valve 16c, and a pressure replenishment oil source 16d. The reverse port of the replenishment check valve 16c is connected to the second internal working oil circuit 20, and the forward port is connected to the pressure replenishment oil source 16d. The accumulator 16a is connected between the replenishment check valve 16c and the pressure replenishment oil source 16d via the on / off switch valve 16b. Thus, when there is a pressure holding requirement, if the oil in the rod chamber is insufficient, due to the pressure difference, the oil stored in the accumulator 16a opens the replenishment check valve 16c and the check valve in the rod chamber balance valve 9, replenishing oil to the rod chamber until the oil pressure difference between the two is insufficient to open the replenishment check valve 16c, thereby always maintaining a low pressure in the rod chamber and ensuring sufficient oil supply.

[0083] Based on the above technical solutions, the present invention also provides an engineering machinery, which includes a leveling outrigger cylinder hydraulic unit of any of the above technical solutions, wherein the first internal working oil circuit 19 and the second internal working oil circuit 20 can be directly or indirectly hydraulically connected to the extension and reversing control oil circuit 25 of the leveling outrigger cylinder.

[0084] The telescopic reversing control oil circuit 25 can adopt a common hydraulic cylinder telescopic control oil circuit, which generally includes a reversing switching valve 25a. The first working oil port and the second working oil port of the reversing switching valve 25a are respectively connected to the first internal working oil circuit 19 and the second internal working oil circuit 20, and the oil inlet and oil return port are respectively connected to the main oil inlet oil circuit and the oil return oil circuit.

[0085] The aforementioned construction machinery can be mobile construction machinery, specifically, it can be a tracked tower crane, wherein the connecting block 1 is fixed to the base frame of the tracked tower crane, and the bottom of the cylinder body 8 of the leveling outrigger cylinder can be fixed to the chassis frame of the tracked tower crane.

[0086] The basic embodiments and preferred embodiments of the present invention have been described above in a hierarchical manner. To aid in the technical understanding of the present invention, the following comparison is provided. Figures 4 to 7This description provides a relatively comprehensive preferred embodiment of the leveling outrigger cylinder mechanism and the leveling outrigger cylinder hydraulic unit of the present invention. In the description, the technical effects of the relevant technical features and the combined technical effects will be explained incidentally, taking the application to a mobile tower crane as an example, so as to more comprehensively and in detail demonstrate the technical effects of the above-mentioned preferred technical features.

[0087] See Figures 4 to 7 The illustrated leveling outrigger cylinder mechanism of the present invention is a relatively comprehensive and preferred method applicable to fixed tower cranes, and is even more effectively suited to mobile tower cranes. It is used to adjust the levelness of the tower crane's base frame. Mobile tower cranes have high requirements for ground slope (flatness), and currently, there is no suitable leveling device for mobile tower cranes specifically designed for ground slope (flatness). In the illustrated embodiment, the mechanical components of the leveling outrigger cylinder mechanism of the present invention mainly include a connecting block 1, a limiting cover plate 4, a ball head 2, a leveling outrigger cylinder with a piston rod 6 and a cylinder body 8, and a self-locking nut 4. The diameter ΦDa of the ball head 2 is larger than the diameter Φd of the piston rod, and ΦD in the figure represents the inner diameter of the cylinder body 8. The ball head 2 is the portion of the entire sphere that exceeds the hemisphere's volume. Generally, a portion of the entire sphere can be cut off, making the volume of the ball head 2 exceed the hemisphere's volume, thus forming the bottom plane of the ball head 2. A circular groove adapted to the end of the piston rod 6 can be formed on the bottom plane of the ball head 2. In this optimal implementation, the ball head 2 and the piston rod 6 are two independent components. The ball head 2 has multiple evenly distributed screw mounting holes (e.g., 8 screw mounting holes) around its circumference. These screw mounting holes penetrate the bottom plane of the ball head 2. The piston rod 6 has multiple threaded holes on its extended end face. Thus, the ball head 2 and the piston rod 6 can be connected by pre-tightening connecting screws 3. During connection, the pre-tightening connecting screws 3 are tightened in place, and a tightening force is applied. This is the form of connection using multiple pre-tightening connecting screws 3.

[0088] The upper part of the piston rod 6 has an external thread section. Specifically, when the piston rod 6 is fully extended, external thread sections can be formed on the outer circumferential surface of the extended section of the piston rod 6. For example, in... Figure 4 The length of the external thread section is equal to the extension end of the piston rod 6 plus the thickness of the self-locking nut 7, plus the extension stroke Sh of the piston rod 6. Thus, when the piston rod 6 is fully retracted, part of the external thread section will be inside the cylinder body 8. During installation, the self-locking nut 7 can be installed on the piston rod 6 first, and then the ball end 2 can be tightened to the piston rod 6 using pre-tightening connecting screws.

[0089] A spherical groove 11 is formed on the bottom plane of the connecting block 2. The spherical groove 11 can be a hemispherical groove, or it can be larger or smaller than a hemispherical groove, but it needs to be smaller than the volume of the ball head 2. When the ball head 2 is installed and fitted into the spherical groove 11, a part of the ball head 2 will protrude downward to the outside of the spherical groove 11, that is, the protruding spherical part 12. The protruding spherical part 12 is spherically fitted by the limiting cover plate 4.

[0090] The limiting cover plate 4 has partially spherical holes machined on it. These partially spherical holes mate with the protruding spherical portion 12 at the lower part of the ball head 2. Specifically, the limiting cover plate 4 has a concave spherical hole 13, which includes a spherical section and a perforated section. The spherical section mates spherically with the protruding spherical portion 12, while the perforated section allows the piston rod 6 to pass through and connect to the bottom plane of the ball head 2. In the installed state, there is a gap between the conical hole section at the lower part of the limiting cover plate 4 and the outer circumferential surface of the piston rod 6. The size of this gap is determined according to the following principle: when the connecting block 1 and the limiting cover plate 4 deflect around the ball head by a predetermined angle θ (usually 2° to 6°, preferably 5°), the edge of the conical hole section of the limiting cover plate 4 contacts the piston rod 6, thereby limiting the deflection angle. Preferably, as... Figure 4 As shown, the perforated section is formed as an outwardly inclined conical hole section, with the semi-apex angle of the conical surface equal to θ. When the cover plate deflects by an angle θ around the center of the spherical head, the edge of the conical hole section contacts the piston rod 6, thereby limiting the deflection angle of the connecting block 1 and the limiting cover plate 4. In addition, a support block 15 for mounting on the frame of a mobile tower crane or on a ground foundation is fixed to the bottom of the cylinder body 8.

[0091] During installation, first install the self-locking nut 7 on the piston rod 6, then put the upper limit cover plate 4 on the piston rod 6, and then fasten the ball head 2 to the protruding end face of the piston rod 6. The connecting block 2 and the upper load (such as the base frame of the tower crane) are fixed in advance with connecting bolts. Align the piston rod 7 with the self-locking nut 7, the upper limit cover plate 4 and the ball head 2 with the spherical groove 11 on the connecting block 1, so that the ball head 2 is installed and fits into the spherical groove 11. Then push the upper limit cover plate 4 upward, so that the protruding spherical part 12 of the ball head 2 fits into the spherical section of the concave spherical hole 13 on the upper limit cover plate 4. Finally, fix the connecting block 1 and the upper limit cover plate 4 with bolts. With this installation method and sequence, when assembling the leveling outrigger cylinder mechanism with the tower crane base frame, the connecting bolts between the four connecting blocks 1 and the base frame can be installed separately first, and then the tower crane base frame and connecting blocks 1 can be assembled as a whole onto the four leveling outrigger cylinders. At this time, it is only necessary to align the four ball heads 2 and then install and tighten the mounting bolts between the connecting blocks 1 and the limit cover plate 4, which greatly simplifies the assembly.

[0092] The mechanical structure of the aforementioned leveling outrigger cylinder mechanism ensures that it can effectively adapt to the travel characteristics required by mobile construction machinery to match the unevenness of the road surface. It can withstand both pressure and tension, and because the leveling outrigger cylinder has a certain angle of deflection adjustment relative to the base frame, it can effectively adapt to road conditions. Specifically, when this mechanical structure of the leveling outrigger cylinder mechanism is working, when the road surface is uneven, the ball joint formed by the ball head 2, the spherical groove 11 of the connecting block 1, and the concave spherical hole 13 of the limiting cover plate 4 allows the piston rod 6 of the leveling outrigger cylinder to deflect at a certain angle relative to the connecting block 1, effectively adapting to the unevenness of the road surface and preventing damage to the leveling outrigger cylinder due to inability to deflect. Simultaneously, the deflection angle limiting structure formed by the gap between the perforated section (preferably a conical hole section) on the limiting cover plate 4 and the outer circumferential surface of the piston rod 6 can limit the deflection of the piston rod 6 within a certain angle, preventing excessive deflection that could affect the safety of the tower crane. In particular, in this type of leveling outrigger cylinder mechanism, when the load above the tower crane base applies pressure to the leveling outrigger cylinder, the presence of high-pressure hydraulic oil in the rodless chamber of the leveling outrigger cylinder effectively supports the piston rod 6 to bear the pressure. Even if the hydraulic pressure in the rodless chamber of the leveling outrigger cylinder fluctuates due to unexpected factors (such as leakage), the self-locking nut 7, when leveled in place, is usually manually or through a drive mechanism adjusted so that its lower end face is against the cylinder head of the leveling outrigger cylinder, forming a reliable mechanical lock. This ensures that even with pressure fluctuations in the hydraulic system, the piston rod 6 can provide sufficient pressure resistance through this mechanical lock. Furthermore, in mobile tower cranes where road conditions cause a slight tilt, regardless of whether the piston rod 6 extends slightly due to tension, the leveling outrigger cylinder mechanism, in its overall mechanical structure, needs to have a strong ability to withstand tensile forces. See [link to relevant documentation]. Figure 4 Because the volume of the ball head 2 exceeds that of a hemisphere, the protruding spherical portion 12, which extends beyond the spherical groove 11, engages with the limiting cover plate 4. The contact surfaces of the concave spherical hole 13 and the protruding spherical portion 12 both face obliquely upwards, providing a strong lifting effect on the ball head 2. When the tower crane base frame drives the connecting block 1 to pull the piston rod 6 upwards, the contact surfaces of the concave spherical hole 13 and the protruding spherical portion 12, as well as the evenly distributed pre-tightening connecting screws 3 between the ball head 2 and the piston rod 6, result in a large overall force-bearing area and relatively uniform force distribution, effectively ensuring that the leveling outrigger cylinder mechanism can withstand the tension. In actual tests of some models of this invention, the leveling outrigger cylinder mechanism with this structure has been able to withstand a tension of up to 1200 tons.

[0093] For both stationary and mobile tower cranes, load adjustment is a frequent occurrence. As mentioned above, stationary tower cranes generally perform unidirectional extension adjustment to ensure safety. However, this is largely unsuitable for mobile tower cranes, which need to adapt to varying road conditions. The variability of road conditions necessitates frequent bidirectional leveling of mobile tower cranes. Furthermore, because the tower body of a mobile tower crane is mounted on a mobile traveling mechanism, its structure differs from that of a stationary tower crane, which is fixed to the foundation. Even during extension leveling, it is crucial to maintain stability as much as possible to prevent vibrations or unevenness during leveling operations that could lead to overturning. This necessitates adding hydraulic components to the existing mechanical structure of the leveling outrigger cylinder mechanism, forming a... Figure 5 and Figure 6 The hydraulic unit for the leveling outriggers is shown.

[0094] See Figure 5 and Figure 6 A rodless chamber balance valve 10 can be installed at the rodless chamber port of the aforementioned leveling outrigger cylinder, and a rod chamber balance valve 9 can be installed at the rod chamber port. This is reflected in the physical structure as follows: Figure 4 As shown, both the rodless chamber balance valve 10 and the rod chamber balance valve 9 can be installed on the side wall of the cylinder body 8. In terms of the hydraulic connection relationship inside the hydraulic unit of the leveling outrigger cylinder, the rodless chamber oil port of the leveling outrigger cylinder and the rodless chamber balance valve 10 can be connected through the first internal working oil circuit 19, and the rod chamber oil port and the rod chamber balance valve 9 can be connected through the second internal working oil circuit 20. The external feedback port 10a of the rodless chamber balance valve 10 is connected to the second internal working oil circuit 20 through the first feedback oil circuit 18, and the external feedback port 9a of the rod chamber balance valve 9 is connected to the first internal working oil circuit 19 through the second feedback oil circuit 17. When both the rodless chamber balance valve 10 and the rod chamber balance valve 9 are located on the side wall of the cylinder body 8, the first internal working oil passage 19, the second internal working oil passage 20, the first feedback oil passage 18, and the second feedback oil passage 17 can generally be formed through internal oil passages formed within the side wall of the cylinder body 8 or hydraulic pipes provided outside the cylinder body 8. Alternatively, they can be formed through a combination of internal oil passages within the cylinder body 8 and external hydraulic pipes. Furthermore, the internal hydraulic connection relationship between the rodless chamber balance valve 10 and the rod chamber balance valve 9 is a common connection relationship within the balance valve itself, and is pre-packaged as an independent valve unit at the factory.

[0095] exist Figures 4 to 6In this relatively comprehensive and preferred optimal embodiment, the rodless chamber balance valve 10 and the rod chamber balance valve 9 provide good operating conditions for bidirectional regulation under load. In particular, the setting of the rodless chamber balance valve 10 makes the regulation under load retraction safer and more reliable. Specifically, a rodless chamber balance valve 10 is installed at the oil outlet of the rodless chamber. The function of the rodless chamber balance valve 10 is as follows: when the outrigger cylinder needs to be adjusted for a loaded retraction action, oil enters the rod chamber of the outrigger cylinder and oil returns from the rodless chamber. In order to avoid excessive load on the piston rod 6 caused by the upper load of the tower crane, which could cause the piston rod 6 to stall and cause danger, the rodless chamber balance valve 10 limits the return oil speed of the rodless chamber and performs dynamic pressure balance regulation. The external feedback port 10a of the rodless chamber balance valve 10 introduces the pressure on the second internal working oil circuit 20 to drive the rodless chamber balance valve 10 to open. When the return oil in the rodless chamber is too fast or too slow, the valve core is dynamically adjusted so that the flow opening of the rodless chamber balance valve 10 is adaptively adjusted, thereby making the loaded retraction regulation action smooth, safe and reliable. Furthermore, a rod chamber balance valve 9 is installed at the oil outlet of the rod chamber. The function of the rod chamber balance valve 9 is as follows: First, when the leveling outrigger cylinder bears the tension of the tower crane, the piston rod 6 tends to extend upwards. At this time, the hydraulic pressure in the rodless chamber is very small, and the oil pressure introduced into the first internal working oil circuit 19 by the external feedback port 9a of the rod chamber balance valve 9 is insufficient to open the rod chamber balance valve 9. The rod chamber balance valve 9 seals the oil in the rod chamber, so that the piston rod 6 of the leveling outrigger cylinder can bear the tension without significant displacement. This makes the entire leveling outrigger cylinder hydraulic pressure... The stability of the pressure unit is better; secondly, the rod chamber balance valve 9 can also make the extension adjustment operation of the leveling outrigger cylinder smoother. Specifically, when the leveling outrigger cylinder extends under load, oil enters the rodless chamber and oil returns from the rod chamber. The external feedback port 9a of the rod chamber balance valve 9 introduces the oil pressure from the first internal working oil circuit 19 (at this time the oil pressure is relatively large). The rod chamber balance valve 9 is driven by the introduced oil pressure to adaptively and dynamically adjust the flow opening and adaptively limit the oil return speed of the rod chamber, making the extension adjustment of the piston rod 6 smoother and safer.

[0096] exist Figure 5 and Figure 6In this relatively comprehensive and preferred optimal embodiment, due to the sudden changes in road conditions of mobile tower cranes, the hydraulic unit of the leveling outrigger cylinder of the present invention also needs to cope with the condition of instantaneous sudden tensile force. Under such instantaneous tensile force conditions, if we want the piston rod 6 to maintain its original extended position and not significantly extend to affect the level of the base frame, it is necessary to maintain sufficient low-pressure oil in the rod chamber at all times in advance. When the oil in the rod chamber is insufficient, it needs to be replenished in advance. That is, in order to cope with possible subsequent instantaneous tensile force conditions, the hydraulic oil in the rod chamber needs to be replenished in advance. In this way, when the outrigger cylinder needs to withstand instantaneous tensile force in a sudden situation, the rod chamber can quickly build up pressure to bear the tensile force, and the piston rod 6 will not have a significant extension displacement, thus affecting the original leveling state. Therefore, a pressure replenishment unit 16 can be connected to the second internal working oil circuit 20 after the rod chamber balance valve 9. That is, in the hydraulic circuit connection, the rod chamber balance valve 9 is positioned between the rod chamber oil port and the pressure replenishment unit 16. The oil pressure of this pressure replenishment unit 16 does not need to be too high; a low pressure is sufficient. If there is a shortage of oil in the rod chamber, the pressure difference between the pressure replenishment unit 16 and the oil in the rod chamber can open the check valve in the rod chamber balance valve 9, thus replenishing the rod chamber with oil. Figure 6 In the relatively comprehensive optimal embodiment shown, the pressure replenishment unit 16 may include an accumulator 16, an on / off switch valve 16b, a replenishment check valve 16c, and a pressure replenishment oil source 16d. The reverse port of the replenishment check valve 16c is connected to the second internal working oil circuit 20, and the forward port is connected to the pressure replenishment oil source 16d. The accumulator 16a is connected between the replenishment check valve 16c and the pressure replenishment oil source 16d via the on / off switch valve 16b. Here, the on / off switching valve 16b can be an electromagnetic switch valve, and the pressure replenishing unit 16d can be a small-displacement oil pump connected to the oil tank. When there is a pressure holding requirement, if the oil in the rod chamber is insufficient, due to the pressure difference, the oil stored in the accumulator 16a opens the replenishing check valve 16c and the check valve in the rod chamber balance valve 9, replenishing oil to the rod chamber until the oil pressure difference between the two is insufficient to open the replenishing check valve 16c, thereby always maintaining a low pressure in the rod chamber and keeping the oil sufficient. In addition, a pressure switch can be installed in the accumulator 16a or at its oil port. When the pressure is detected to be lower than the set value P0 (e.g., 1 bar), the pressure replenishing oil source 16d is activated to fill the accumulator 16a with oil until the pressure recovers to K*P0, and then the filling stops. K is a coefficient with a value greater than 1, generally greater than 1.2 and less than 1.5.

[0097] In engineering machinery employing the hydraulic unit of the leveling outrigger cylinder with the above-described preferred embodiment, such as a mobile tower crane, the first internal working oil circuit 19 and the second internal working oil circuit 20 can be hydraulically connected to the telescopic reversing control oil circuit 25 of the leveling outrigger cylinder. The telescopic reversing control oil circuit is well known to those skilled in the art and generally includes a reversing valve 25a (e.g., a three-position four-way reversing valve). The first and second working ports of the reversing valve 25a are respectively hydraulically connected to the first internal working oil circuit 19 and the second internal working oil circuit 20. The inlet and return ports are respectively connected to the main inlet oil circuit and the main return oil circuit. The main return oil circuit is connected to the oil tank 25. A main oil pump 25b is generally installed on the main inlet oil circuit. In addition, an overflow valve or similar device can usually be installed for pressure limiting.

[0098] See Figure 7 The above-mentioned relatively comprehensive optimal implementation method of the leveling outrigger cylinder hydraulic unit is applied to the working process of the mobile tower crane, mainly including: (1) The leveling outrigger cylinder extends upward to perform load extension leveling action. At this time, through the switching of the telescopic reversing control oil circuit, the rodless chamber of the leveling outrigger cylinder is supplied with pressure oil, and the rod chamber returns oil. Through the dynamic pressure adjustment of the rod chamber pressure balance valve 9, the return oil speed of the rod chamber is limited, and the piston rod 6 of the leveling outrigger cylinder extends smoothly until it is adjusted to the position. The reversing valve 25a in the telescopic reversing control oil circuit 25 is switched to the middle position. At this time, the rodless chamber balance valve 10 locks the high pressure oil in the rodless chamber. The force on the outrigger cylinder is borne by the hydraulic oil. The self-locking nut 7 is not subject to axial force. At the same time, in order to prevent accidents, the self-locking nut 7 can be manually or through the drive mechanism to move downward until it is close to the cylinder head of the cylinder body 8, so that the self-locking nut 7 can ultimately bear the mechanical load in the event of an accident. (2) The leveling outrigger cylinder moves downward under load to level and retract. At this time, the rod chamber of the leveling outrigger cylinder is supplied with pressurized oil, and the rodless chamber returns oil. The pressure is dynamically balanced by the rodless chamber balance valve 10 to limit the return speed of the rodless chamber. Rotating the self-locking nut 7 upward can make the upward movement speed of the self-locking nut 7 consistent with the retraction speed of the cylinder, or the self-locking nut 7 can be manually adjusted upward in advance before retraction and leveling.

[0099] As can be seen from the above description, the advantages of the leveling outrigger cylinder mechanism of the present invention are:

[0100] First, regarding the basic implementation of the leveling outrigger cylinder mechanism of the present invention, its unique mechanical load-bearing structure design, through the specific structural cooperation between the ball head 2, connecting block 1, and limiting cover plate 4, ensures uniform force distribution and load transmission, enabling the leveling outrigger cylinder mechanism to withstand both pressure and tension. From a mechanical structure perspective, this ensures that the leveling outrigger cylinder can effectively adapt to the walking characteristics of mobile engineering machinery. At the same time, this unique mechanical structure design improves the installation method and installation sequence, effectively simplifies the installation work, and makes installation more convenient and easier.

[0101] Secondly, in the preferred embodiment of the leveling outrigger cylinder mechanism of the present invention, the present invention ingeniously uses the structural cooperation between the limiting cover plate 4 and the piston rod to limit the deflection angle by the gap between the limiting cover plate 4 and the piston rod 6. In practical applications, this can ensure the safety and reliability of mobile engineering machinery and simplify the structure.

[0102] Third, in the hydraulic unit of the leveling outrigger cylinder of the present invention, the innovative design of the dual balance valve (i.e., rod chamber balance valve 9 and rodless chamber balance valve 10) makes the working oil circuits of the two valves mutually external oil pressure feedback circuits, effectively limiting the return oil speed of extension and retraction, and performing dynamic pressure balance and dynamic adjustment of return oil flow opening. This ensures that under load conditions, the piston rod 6 can extend smoothly and safely, and also retract smoothly and safely, effectively realizing bidirectional load leveling operation.

[0103] Fourth, and most importantly, in the preferred embodiment of the present invention, the present invention can withstand the instantaneous tension generated in sudden situations. Through the original design of the pressure-replenishing oil source, it cleverly utilizes the pressure difference formed by the lack of oil in the rod chamber to replenish the hydraulic oil in the rod chamber at all times, thus preparing in advance to withstand instantaneous tension. In this way, even if the leveling outrigger cylinder is subjected to instantaneous tension due to bumpy road conditions during the operation of the mobile engineering machinery, the sufficient oil in the rod chamber can instantly resist the tension, ensuring the stability of the piston rod 6 and effectively preventing the piston rod 6 from losing its position and affecting the original leveling effect.

[0104] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0105] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0106] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A leveling outrigger cylinder mechanism, comprising a leveling outrigger cylinder and a connecting block (1), characterized in that, A spherical groove (11) is formed on the connecting block (1). The extended end of the piston rod (6) of the leveling support cylinder is equipped with a ball head (2) through a tension bearing structure. The ball head (2) and the piston rod (6) are two independent parts. The diameter of the ball head (2) is larger than the diameter of the piston rod (6). The ball head (2) is installed and fitted into the spherical groove (11) and has a protruding spherical part (12) protruding out of the spherical groove. A limiting cover plate (4) is fixed on the connecting block (1). The limiting cover plate (4) is adapted to be fitted onto the piston rod (6). The limiting cover plate (4) has a concave spherical hole (13) that cooperates with the protruding spherical part (12) to form a spherical fit between the concave spherical hole (13) and the spherical surface of the protruding spherical part (12) and connect and limit the ball head (2). The piston rod (6) has an external thread section, on which a self-locking nut (7) is installed. The self-locking nut (7) is located outside the cylinder head of the leveling support cylinder, and the rotation achieved by the threaded engagement can be abutted against the cylinder head to achieve self-locking of the piston rod (6).

2. The leveling outrigger cylinder mechanism according to claim 1, characterized in that, The ball head (2) is mounted to the end of the piston rod (6) via the tension bearing structure, wherein The tensile bearing structure includes pre-tightening connecting screws (3), a plurality of screw mounting holes formed on the ball head (2) and penetrating the bottom plane of the ball head (2), and a plurality of threaded holes formed on the end face of the piston rod (6), wherein the bottom plane of the ball head (2) is in contact with the end face of the piston rod (6), and the plurality of pre-tightening connecting screws (3) are respectively installed into the plurality of threaded holes through the plurality of screw mounting holes and pre-tightened.

3. The leveling outrigger cylinder mechanism according to claim 2, characterized in that, The plurality of screw mounting holes are evenly distributed along the circumferential direction on the bottom plane of the ball head, and the plurality of threaded holes are evenly distributed along the circumferential direction on the end face of the piston rod (6).

4. The leveling outrigger cylinder mechanism according to claim 1, characterized in that, The connecting block (1) is provided with multiple load bolt mounting holes for connecting the upper load; and the limiting cover plate (4) is fixed to the connecting block (1) by connecting bolts (5).

5. The leveling outrigger cylinder mechanism according to claim 1, characterized in that, The volume of the sphere head (2) exceeds the volume of a hemisphere.

6. The leveling outrigger cylinder mechanism according to any one of claims 1 to 5, characterized in that, The limiting cover (4) has a limiting structure (14) for limiting the deflection angle of the ball head (2).

7. The leveling outrigger cylinder mechanism according to claim 6, characterized in that, The concave spherical hole (13) on the limiting cover plate (4) includes a spherical section that mates with the protruding spherical portion (12) and a perforated section into which the piston rod (6) extends. The perforated section is formed as a conical hole section and has a gap with the outer peripheral surface of the piston rod (6) to serve as the limiting structure.

8. The leveling outrigger cylinder mechanism according to claim 7, characterized in that, The perforated section is formed as a conical hole section, and the gap between the conical hole section and the outer peripheral surface of the piston rod (6) limits the deflection angle θ of the ball head (2) to 2° to 6°.

9. A hydraulic unit for adjusting outrigger cylinders, characterized in that, The system includes a leveling outrigger cylinder mechanism according to any one of claims 1 to 8, wherein a rodless chamber balance valve (10) is provided on the first internal working oil circuit (19) connected to the rodless chamber oil port of the leveling outrigger cylinder, and a rod chamber balance valve (9) is provided on the second internal working oil circuit (20) connected to the rod chamber oil port. The external feedback port (10a) of the rodless chamber balance valve (10) is connected to the second internal working oil circuit (20) via the first feedback oil circuit (18), and the external feedback port (9a) of the rod chamber balance valve (9) is connected to the first internal working oil circuit (19) via the second feedback oil circuit (17).

10. The hydraulic unit for the leveling outrigger cylinder according to claim 9, characterized in that, The rodless chamber balance valve (10) and the rod chamber balance valve (9) are both located on the side wall of the cylinder body (8) of the leveling outrigger cylinder, and the first internal working oil circuit (19), the second internal working oil circuit (20), the first feedback oil circuit (18) and the second feedback oil circuit (17) are formed through the internal oil passage in the side wall of the cylinder body (8) and / or the hydraulic pipeline outside the cylinder body (8).

11. The hydraulic unit for the leveling outrigger cylinder according to claim 9, characterized in that, The second internal working oil circuit (20) is also connected to a pressure replenishing unit (16), and is connected such that the rod chamber balance valve (9) is located between the rod chamber port and the pressure replenishing unit (16) on the second internal working oil circuit (20).

12. The hydraulic unit for the leveling outrigger cylinder according to claim 11, characterized in that, The pressure replenishment unit (16) includes an accumulator (16a), an on / off switch valve (16b), a replenishment check valve (16c), and a pressure replenishment oil source (16d). The reverse port of the replenishment check valve (16c) is connected to the second internal working oil circuit (20), and the forward port is connected to the pressure replenishment oil source (16d). The accumulator (16a) is connected between the replenishment check valve (16c) and the pressure replenishment oil source (16d) via the on / off switch valve (16b).

13. An engineering machinery, characterized in that, The engineering machinery includes a hydraulic unit for a leveling outrigger cylinder according to any one of claims 9 to 12, wherein the first internal working oil circuit (19) and the second internal working oil circuit (20) are connected to the extension and reversing control oil circuit (25) of the leveling outrigger cylinder.

14. The engineering machinery according to claim 13, characterized in that, The telescopic reversing control oil circuit (25) includes a reversing switching valve (25a), the first working oil port and the second working oil port of the reversing switching valve (25a) are respectively connected to the first internal working oil circuit (19) and the second internal working oil circuit (20) respectively, and the oil inlet and the oil return port are respectively connected to the main oil inlet oil circuit and the oil return oil circuit respectively.

15. The engineering machinery according to claim 13 or 14, characterized in that, The construction machinery is a tracked tower crane, wherein the connecting block (1) is fixed to the base frame of the tracked tower crane, and the bottom of the cylinder body (8) of the leveling outrigger cylinder is fixed to the chassis frame of the tracked tower crane.

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