Differential type bidirectional parallel four-outlet-rod synchronous combined hydraulic cylinder

Abstract

The differential type two-way parallel four-outlet-rod synchronous combined hydraulic cylinder comprises a first double-outlet-rod combined hydraulic cylinder and a second double-outlet-rod combined hydraulic cylinder, wherein two single-outlet-rod hydraulic cylinders share the same cylinder bottom and are combined into a whole in the axial direction to form the first double-outlet-rod combined hydraulic cylinder and the second double-outlet-rod combined hydraulic cylinder; and the first double-outlet-rod combined hydraulic cylinder and the second double-outlet-rod combined hydraulic cylinder are radially connected in parallel and combined to form a four-outlet-rod hydraulic cylinder. The number of independent hydraulic cylinders is effectively reduced, a support structure for independently installing multiple cylinders is eliminated, and the overall size is remarkably reduced. The integrated oil way system can remarkably reduce the number of external pipelines, and the leakage risk caused by intersection of multiple pipelines is avoided. The symmetrical layout of the four piston rods enhances the structural stability, effectively improves the synchronous action precision, and is suitable for space-limited scenes such as a steering system. The whole structure realizes function expansion through modular combination, and the manufacturing cost is reduced while the synchronization performance is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic cylinders, in particular to a differential bidirectional parallel four-rod synchronous combination hydraulic cylinder. Background Art

[0002] The rapid development of specialized equipment and machinery is placing higher demands on the functionality of hydraulic actuators. Traditional hydraulic cylinders have significant functional limitations in applications such as specialized vehicle steering systems. Existing technologies typically utilize multiple independent hydraulic cylinders connected in parallel to achieve multi-directional synchronized motion. This approach not only requires complex piping systems but also consumes significant installation space. Especially in space-constrained equipment environments, the placement of multiple hydraulic cylinders often impacts the overall machine layout.

[0003] The main technical challenges facing current hydraulic cylinder technology include: the difficulty of achieving precise synchronous control in multi-cylinder parallel systems; complex piping arrangements increase the risk of system leakage; the installation of multiple independent hydraulic cylinders requires additional support structures; and the system's high energy consumption and maintenance difficulties. These issues are particularly prominent in operating conditions requiring bidirectional synchronous extension and locking, such as in vehicle steering systems, where the synchronization accuracy of left and right steering movements directly affects the vehicle's handling performance.

[0004] While existing hydraulic cylinders can achieve basic telescopic functions, they lack differential, bidirectional, synchronous control. To synchronize the telescopic movement of four piston rods, traditional solutions require four independent hydraulic cylinders, increasing system complexity and reducing control accuracy. Furthermore, connecting the multiple hydraulic cylinders requires numerous connectors and pipes, significantly increasing the risk of system failure. Summary of the Invention

[0005] In view of this, the present invention provides a differential bidirectional parallel four-rod synchronous combination hydraulic cylinder, which has the advantages of compact structure, high synchronization accuracy, high installation space utilization and can significantly reduce the risk of system leakage.

[0006] To achieve the above object, the present invention provides the following technical solutions: A differential bidirectional parallel four-rod synchronous combination hydraulic cylinder comprises: a first double-rod combination hydraulic cylinder and a second double-rod combination hydraulic cylinder which are formed by two single-rod hydraulic cylinders sharing the same cylinder bottom and being combined into one in the axial direction; the first double-rod combination hydraulic cylinder and the second double-rod combination hydraulic cylinder are radially parallel combined to form a four-rod hydraulic cylinder.

[0007] Preferably, the middle parts of the first double-rod combination hydraulic cylinder and the second double-rod combination hydraulic cylinder are both provided with an integrated cylinder bottom, wherein the integrated cylinder bottom of the first double-rod combination hydraulic cylinder is provided with a plug-in slot, and the integrated cylinder bottom of the second double-rod combination hydraulic cylinder is provided with a plug, and the first double-rod combination hydraulic cylinder and the second double-rod combination hydraulic cylinder are combined in parallel through the cooperation of the plug-in slot and the plug.

[0008] Preferably, the plug-in slot is a cross-shaped square slot.

[0009] Preferably, the integrated cylinder bottom is a square and round integrated cylinder bottom.

[0010] Preferably, the differential bidirectional parallel four-rod synchronous combination hydraulic cylinder further includes a connecting plate, which is arranged on the side of the four-rod hydraulic cylinder and is fixedly connected to the first double-rod combination hydraulic cylinder and the second double-rod combination hydraulic cylinder respectively.

[0011] Preferably, the differential bidirectional parallel four-rod synchronous combination hydraulic cylinder also includes a joint assembly, the joint assembly includes a first joint seat, a first joint pipeline, a second joint seat and a second joint pipeline, the first joint seat and the second joint seat are installed on the first double-rod combination hydraulic cylinder separately, the first joint seat and the second joint seat are both provided with joint oil ports, the first joint seat is connected to the two oil inlet chambers in the first double-rod combination hydraulic cylinder and the two return oil chambers in the second double-rod combination hydraulic cylinder through the first joint pipeline, and the second joint seat is connected to the two return oil chambers in the first double-rod combination hydraulic cylinder and the two oil inlet chambers in the second double-rod combination hydraulic cylinder through the second joint pipeline.

[0012] Preferably, both end earrings of the first double-rod combination hydraulic cylinder and both end earrings of the second double-rod combination hydraulic cylinder are installed with spherical bearings.

[0013] Preferably, a sensor connector seat is installed on the cylinder barrel of the first double-rod combination hydraulic cylinder and the second double-rod combination hydraulic cylinder, and a proximity switch is installed on the sensor connector seat.

[0014] The beneficial effects of this invention are as follows: Compared with the existing technology, this application effectively reduces the number of independent hydraulic cylinders, eliminates the bracket structure for independently mounted multiple cylinders, and significantly reduces the overall volume. The integrated oil circuit system significantly reduces the number of external pipelines and avoids the risk of leakage caused by multiple intersecting pipelines. The symmetrical layout of the four piston rods enhances structural stability and effectively improves the accuracy of synchronous movement, making it suitable for space-constrained scenarios such as steering systems. The overall structure achieves functional expansion through modular combination, reducing manufacturing costs while ensuring synchronization performance.

[0015] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a cross-sectional view of a differential bidirectional parallel four-rod synchronous combination hydraulic cylinder of the present invention; Figure 2 This is a front view of a differential bidirectional parallel four-rod synchronous combination hydraulic cylinder of the present invention; Figure 3 It is a side view of the differential bidirectional parallel four-rod synchronous combination hydraulic cylinder of the present invention.

[0017] Reference numerals: 1. Earring; 2. Cylinder; 3. First joint seat; 4. First joint pipeline; 5. Second joint seat; 6. Second joint pipeline; 7. Integrated cylinder bottom; 8. Cross-shaped square groove; 9. Connecting plate; 10. Sensor joint seat. DETAILED DESCRIPTION

[0018] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0019] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0020] Reference below Figures 1 to 3 The differential bidirectional parallel four-rod synchronous combination hydraulic cylinder in the embodiment of the present invention is described.

[0021] Disclosed in an embodiment of the present application is a differential, bidirectional, parallel, four-rod synchronous combination hydraulic cylinder, comprising: a first double-rod combination hydraulic cylinder and a second double-rod combination hydraulic cylinder, which are formed by two single-rod hydraulic cylinders sharing the same cylinder bottom and being combined into one in the axial direction; the first double-rod combination hydraulic cylinder and the second double-rod combination hydraulic cylinder are radially parallel combined to form a four-rod hydraulic cylinder.

[0022] Sharing a common cylinder base refers to the two single-rod hydraulic cylinders forming a single structure by sharing a common cylinder base at their axial ends. This can be achieved by joining the two cylinder ends through casting or welding, reducing the number of components by eliminating a separate cylinder base. A radially parallel combination refers to the connection of two dual-rod hydraulic cylinders along a vertical axis. This can be achieved by using a plug-in structure or a connecting plate 9, achieving a symmetrical distribution of four piston rods through an orthogonal spatial layout.

[0023] Specifically, two single-rod hydraulic cylinders form a dual-rod unit with bidirectional output capability by sharing a common cylinder bottom. This structural integration allows the two cylinders to share a hydraulic chamber, reducing the redundant sealing structure required in traditional multi-cylinder splicing. The two dual-rod units are radially connected in parallel to form a four-rod structure, with the four piston rods arranged symmetrically in orthogonal directions in space. When hydraulic oil is input through the integrated oil circuit, the two dual-rod units form a differential oil circuit system, causing the four piston rods to produce synchronous reverse motion. The shared cylinder bottom design provides the structural foundation for oil circuit integration, allowing the oil inlet and return chambers to communicate internally within the combined unit, eliminating the need for complex external piping.

[0024] Compared to existing technologies, traditional solutions require four independent hydraulic cylinders to achieve the movement of four piston rods. This solution reduces the number of hydraulic cylinders to two combined units through structural combination. While existing technologies require separate mounting brackets for multiple cylinders, this solution achieves a monolithic structure through radial parallel connection, reducing installation complexity. Traditional multi-circuit systems require four or more sets of pipeline connections, while this solution integrates the oil circuits using a common cylinder bottom, requiring only two main oil circuits to control the synchronized movement of the four piston rods.

[0025] Through the above technical solution, this application effectively reduces the number of independent hydraulic cylinders, eliminates the bracket structure for independently installed multiple cylinders, and significantly reduces the overall volume. The integrated oil circuit system will significantly reduce the number of external pipelines and avoid the risk of leakage caused by multiple pipe crossings. The symmetrical layout of the four piston rods enhances structural stability and effectively improves the accuracy of synchronous movement, making it suitable for space-constrained scenarios such as steering systems. The overall structure achieves functional expansion through modular combination, reducing manufacturing costs while ensuring synchronization performance.

[0026] In some embodiments, for example Figure 1 As shown, both the first and second double-rod combination hydraulic cylinders have an integrated cylinder bottom 7 in their central portions. The integrated cylinder bottom 7 of the first double-rod combination hydraulic cylinder has a plug slot, while the integrated cylinder bottom 7 of the second double-rod combination hydraulic cylinder has a plug. The first and second double-rod combination hydraulic cylinders are connected in parallel through the plug slot and the plug. The plug slot is a cross-shaped square slot 8. The integrated cylinder bottom 7 is a square-round integrated cylinder bottom 7.

[0027] Among them, the integrated cylinder bottom 7 refers to a structure in which two single-rod hydraulic cylinders share the same cylinder bottom and are combined into one in the axial direction. By eliminating the connection interface of the split cylinder bottom, the structural strength of the cylinder body can be improved and the risk of sealing failure can be avoided. The plug-in slot refers to a groove structure provided on the integrated cylinder bottom 7, which can be specifically implemented by the geometric shape of a cross-shaped square slot 8. By limiting the freedom of movement of the plug, mechanical limitation in the left and right and front and back directions can be achieved. The plug refers to a protruding structure that matches the plug-in slot, which can be specifically implemented by a cross-shaped protruding structure that complements the plug-in slot. By embedding the plug-in slot to form an interlocking fit, the radial positioning accuracy of the two double-rod hydraulic cylinders can be ensured.

[0028] Specifically, when two dual-rod hydraulic cylinders are connected in parallel, the plug is inserted into the socket, and automatic alignment is achieved by matching their geometric shapes. The cross-shaped square groove 8 of the socket limits the lateral displacement of the plug in the horizontal plane, while the close fit between the plug and the socket eliminates relative offset during radial movement. The integrated cylinder bottom 7 provides rigid support for the socket structure, preventing deformation caused by localized stress concentration. Through the mechanical interlocking of the socket and the plug, the two hydraulic cylinders can be fixed without the need for bolts or welding. The self-alignment during the plug-in process also simplifies assembly steps.

[0029] Through the above technical solution, the present application solves the problems of complex structure, insufficient connection stability and low assembly efficiency when two double-rod hydraulic cylinders are combined in parallel. The plug-in structure replaces the traditional connection method, so that the parallel combination process of the hydraulic cylinders can be accurately positioned without complex tooling. The coordinated design of the integrated cylinder bottom 7 and the plug-in slot enhances the overall structural rigidity and ensures the relative position stability of the two cylinders under high-pressure conditions. The limiting function of the cross-shaped square groove 8 prevents the hydraulic cylinder from being misaligned when subjected to radial force, thereby improving the reliability of the synchronous action.

[0030] In some embodiments, for example Figure 1 and Figure 2 As shown, the differential bidirectional parallel four-rod synchronous combination hydraulic cylinder also includes a connecting plate 9, which is arranged on the side of the four-rod hydraulic cylinder and is fixedly connected to the first double-rod combination hydraulic cylinder and the second double-rod combination hydraulic cylinder respectively.

[0031] The connecting plate 9 is a planar metal plate that can be rigidly fixed to the side walls of the hydraulic cylinders by welding or bolting. This member covers the side contact surfaces of the two hydraulic cylinders to form a lateral constraint, which is used to offset the shear force generated by the radial parallel combination.

[0032] Specifically, after the connector slots are positioned horizontally and longitudinally, a connecting plate 9 is mounted on the outer side surfaces of the two dual-rod combination hydraulic cylinders. By welding the edges of the connecting plate 9 to the sidewalls of the cylinder barrels 2 of the upper and lower hydraulic cylinders, a continuous, rigid connection interface is formed. This connection interface covers the lateral projection of the parallel hydraulic cylinder assembly, mechanically preventing vertical displacement between the upper and lower hydraulic cylinders.

[0033] Through the above-mentioned technical solution, the present application effectively eliminates the risk of vertical misalignment that may occur when dual-rod hydraulic cylinders are connected in radial parallel. The lateral rigid connection also enhances the assembly's torsional resistance under dynamic conditions. The planar mounting of the connecting plate 9 provides mechanical constraints in all six degrees of freedom of the hydraulic cylinder assembly without increasing the radial installation space required for the hydraulic cylinders, thus meeting the requirements for a compact layout of actuators in specialized equipment.

[0034] In some embodiments, for example Figure 1 and Figure 2 As shown, the differential bidirectional parallel four-rod synchronous combination hydraulic cylinder also includes a joint assembly, which includes a first joint seat 3, a first joint pipeline 4, a second joint seat 5 and a second joint pipeline 6. The first joint seat 3 and the second joint seat 5 are installed on the first double-rod combination hydraulic cylinder at intervals. The first joint seat 3 and the second joint seat 5 are both provided with joint oil ports. The first joint seat 3 is connected to the two oil inlet chambers in the first double-rod combination hydraulic cylinder and the two return oil chambers in the second double-rod combination hydraulic cylinder through the first joint pipeline 4. The second joint seat 5 is connected to the two return oil chambers in the first double-rod combination hydraulic cylinder and the two oil inlet chambers in the second double-rod combination hydraulic cylinder through the second joint pipeline 6.

[0035] Among them, the first connector seat 3 refers to an integrated oil circuit interface for centrally connecting the oil inlet chamber and the oil return chamber. Specifically, it can be implemented by a metal block structure with multiple internal flow channels. The internal flow channels are arranged crosswise to achieve directional distribution of oil between the upper and lower hydraulic cylinders. The second connector seat 5 refers to another set of integrated interfaces that cooperate with the first connector seat 3 to achieve reverse oil circuit control. Its internal flow channel layout is mirror-symmetrical with the first connector seat 3, ensuring that the oil circuit switching logic of the upper and lower hydraulic cylinders is complementary. The first connector pipeline 4 refers to a rigid or flexible conduit connecting the first connector seat 3 and the corresponding oil chambers of the upper and lower hydraulic cylinders. Specifically, a high-pressure resistant metal hard pipe or composite hose can be used, such as a steel pipe with an inner diameter of 8 mm, and a sealed connection is achieved through a flange or a sleeve-type joint. The structure of the second connector pipeline 6 is the same as that of the first connector pipeline 4, but the connection path is different, and it is used to achieve reverse oil flow control. The connector oil port refers to a standardized hydraulic interface arranged on the outer surface of the connector seat, which is used to quickly connect to an external oil source.

[0036] Specifically, when external hydraulic oil is input through the oil port of the first joint seat 3, the oil simultaneously enters the two oil inlet chambers of the first double-rod combination hydraulic cylinder through the first joint pipeline 4, driving its piston rod to extend synchronously. At the same time, the two return oil chambers of the second double-rod combination hydraulic cylinder are connected through the same pipeline to form an oil return channel, causing the corresponding piston rods to retract synchronously. When the oil flow direction is switched to the second joint seat 5, the oil enters the return oil chamber of the first double-rod combination hydraulic cylinder through the second joint pipeline 6 to retract its piston rod. At the same time, the oil inlet chamber of the second double-rod combination hydraulic cylinder obtains pressurized oil to drive the piston rod to extend. This cross-oil circuit design realizes the differential action of the upper and lower hydraulic cylinders through a single oil port control. The oil forms a closed loop between the two groups of hydraulic cylinders, and there is no need to set up an additional independent return oil pipeline. The spaced installation method of the joint seats can avoid oil circuit interference. For example, the center distance between the two joint seats is kept at 1.5 times the width of the joint seat to ensure sufficient space for pipeline layout.

[0037] Through the above-mentioned technical solution, this application effectively solves the oil circuit system complexity problem caused by the combination of multiple hydraulic cylinders, effectively reducing the space occupied by external oil circuit connection points and piping layout. The cross-circuit design creates a force-couple motion relationship between the upper and lower hydraulic cylinders, enabling synchronous opposite deflection of the left and right wheels in the vehicle steering system. The sealing structure of the integrated joint assembly meets the high reliability requirements of special equipment. The dual-port control method eliminates the need for an additional directional switching valve in the hydraulic system, effectively reducing system complexity.

[0038] In some embodiments, for example Figure 1 As shown, both end earrings 1 of the first double-rod combination hydraulic cylinder and the end earrings 1 of the second double-rod combination hydraulic cylinder are equipped with spherical bearings.

[0039] The spherical plain bearing (SAB) is a spherical sliding bearing capable of rotating with multiple degrees of freedom. Specifically, it can be implemented using a spherical contact structure with an inner and outer ring. The relative rotation of the inner and outer rings allows for load transfer in different directions. The earring 1 is an annular connecting component provided at the end of the piston rod. Specifically, it can be implemented using a forged or machined annular flange structure, which is used to connect to the mainframe structure via a pin.

[0040] Specifically, when the four piston rods of the hydraulic cylinder perform bidirectional synchronous telescopic movements, the spherical bearing allows the earring 1 to produce slight displacements in the axial, radial and angular directions. During the extension or retraction of the piston rod, the sliding of the spherical contact surface between the inner and outer rings of the spherical bearing compensates for changes in the connection point position caused by load direction offset or structural component installation errors. As a result, the earrings 1 at the ends of the four piston rods can independently adjust their posture to avoid interference in the motion trajectories of adjacent piston rods due to single-directional constraints. At the same time, the rotational freedom of the spherical bearing can disperse the local stress at the connection between the piston rod and the main structural component, preventing stress concentration caused by rigid connection.

[0041] Through the above technical solution, this application realizes the reliable connection between the four piston rods of the hydraulic cylinder and the main structural parts when they are synchronously extended and retracted in different directions, eliminating the stress concentration and motion interference problems caused by changes in the direction of movement, and improving the adaptability and service life of the hydraulic cylinder under complex working conditions.

[0042] In some embodiments, for example Figure 1 and Figure 2 As shown, a sensor connector seat 10 is installed on the cylinder barrel 2 of the first double-rod combination hydraulic cylinder and the second double-rod combination hydraulic cylinder, and a proximity switch is installed on the sensor connector seat 10.

[0043] The sensor connector 10 is a mounting base fixed to the outer wall of the cylinder 2. Specifically, it can be a metal base with threaded holes or a snap-fit ​​structure. It is used to support the proximity switch and provide a stable mounting position. The proximity switch is a sensing device used to detect the position of the piston rod. Specifically, it can be implemented as an inductive or capacitive non-contact sensor. It generates an electrical signal by sensing the position change of the metal trigger plate at the end of the piston rod or on the piston.

[0044] Specifically, when the hydraulic cylinder is working, the piston rod performs telescopic movement in the cylinder barrel 2, and the proximity switch installed on the sensor connector seat 10 detects the movement stroke of the piston rod in a non-contact manner. For example, when the piston rod is extended to the preset position, the proximity switch senses the trigger plate and outputs a signal, which is transmitted to the control system to trigger the locking action or switch the direction of the oil circuit. The cylinder barrels 2 of the two double-rod combination hydraulic cylinders are both equipped with this detection structure, so that the position status of the four piston rods can be monitored independently. The fixed connection between the sensor connector seat 10 and the cylinder barrel 2 avoids detection deviations caused by vibration, and the detachable design of the proximity switch facilitates maintenance or replacement.

[0045] Through the above-mentioned technical solution, this application solves the problem of difficulty in real-time monitoring of the piston rod position during differential, bidirectional, synchronous extension and retraction of hydraulic cylinders. It achieves precise detection and feedback of the motion status of the four piston rods, thereby ensuring the coordination of synchronous movement and the reliability of positioning and locking. For example, in the steering system of special vehicles, this technology can effectively avoid steering asynchrony caused by piston rod position deviation, improving the accuracy and safety of system control.

[0046] Other structures and operations of the differential bidirectional parallel four-rod synchronous combination hydraulic cylinder according to the embodiment of the present invention are well known to those skilled in the art and will not be described in detail here.

[0047] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0048] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A differential bidirectional parallel four-rod synchronous combination hydraulic cylinder, characterized in that: include: A first double-rod combined hydraulic cylinder and a second double-rod combined hydraulic cylinder are formed by two single-rod hydraulic cylinders sharing the same cylinder bottom and being integrated in the axial direction; The first double-rod combination hydraulic cylinder and the second double-rod combination hydraulic cylinder are radially connected in parallel to form a four-rod hydraulic cylinder.

2. The differential bidirectional parallel four-rod synchronous combination hydraulic cylinder according to claim 1, characterized in that: The middle part of the first double-rod combination hydraulic cylinder and the second double-rod combination hydraulic cylinder are both provided with an integrated cylinder bottom, wherein the integrated cylinder bottom of the first double-rod combination hydraulic cylinder is provided with a plug-in slot, and the integrated cylinder bottom of the second double-rod combination hydraulic cylinder is provided with a plug, and the first double-rod combination hydraulic cylinder and the second double-rod combination hydraulic cylinder are combined in parallel through the cooperation of the plug-in slot and the plug.

3. The differential bidirectional parallel four-rod synchronous combination hydraulic cylinder according to claim 2, characterized in that: The plug-in slot is a cross-shaped square slot.

4. The differential bidirectional parallel four-rod synchronous combination hydraulic cylinder according to claim 2, characterized in that: The integrated cylinder bottom is a square and round integrated cylinder bottom.

5. The differential bidirectional parallel four-rod synchronous combination hydraulic cylinder according to claim 1, characterized in that: It also includes a connecting plate, which is arranged on the side of the four-rod hydraulic cylinder and is fixedly connected to the first double-rod combination hydraulic cylinder and the second double-rod combination hydraulic cylinder respectively.

6. The differential bidirectional parallel four-rod synchronous combination hydraulic cylinder according to claim 1, characterized in that: It also includes a joint assembly, which includes a first joint seat, a first joint pipeline, a second joint seat and a second joint pipeline. The first joint seat and the second joint seat are installed on the first double-rod combination hydraulic cylinder with intervals. The first joint seat and the second joint seat are both provided with joint oil ports. The first joint seat is connected to the two oil inlet chambers in the first double-rod combination hydraulic cylinder and the two oil return chambers in the second double-rod combination hydraulic cylinder through the first joint pipeline. The second joint seat is connected to the two oil return chambers in the first double-rod combination hydraulic cylinder and the two oil inlet chambers in the second double-rod combination hydraulic cylinder through the second joint pipeline.

7. The differential bidirectional parallel four-rod synchronous combination hydraulic cylinder according to claim 1, characterized in that: Spherical bearings are installed on the earrings at both ends of the first double-rod combined hydraulic cylinder and the earrings at both ends of the second double-rod combined hydraulic cylinder.

8. The differential bidirectional parallel four-rod synchronous combination hydraulic cylinder according to claim 1, characterized in that: A sensor joint seat is installed on the cylinder barrels of the first double-rod combined hydraulic cylinder and the second double-rod combined hydraulic cylinder, and a proximity switch is installed on the sensor joint seat.

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