Bridge detection vehicle parallel oil cylinder synchronous control system

Abstract

The utility model provides a kind of bridge detection vehicle parallel oil cylinder synchronous control system, including oil cylinder group and for connecting hydraulic oil tank and oil cylinder group realizes the reversing valve of oil cylinder group oil supply, oil return, each oil cylinder group includes at least two oil cylinders;The rodless cavity of each oil cylinder of same group oil cylinder group is connected rodless cavity total oil path in parallel by respective rodless cavity branch, and the rod cavity of each oil cylinder is connected rod cavity total oil path in parallel by respective rod cavity branch;The rodless cavity total oil path and rod cavity total oil path are connected with different oil ports of reversing valve respectively;First throttling connector is respectively arranged on each rod cavity branch, and second throttling connector is respectively arranged on each rodless cavity branch, so that each oil cylinder in same group oil cylinder synchronously acts.

Description

Technical Field

[0001] This utility model belongs to the field of bridge inspection vehicles, specifically relating to a parallel hydraulic cylinder synchronous control system for bridge inspection vehicles. Background Technology

[0002] Before bridge inspection vehicles can perform bridge inspection operations, they need to be deployed to the area under the bridge. During this process, two independent guardrail cylinders are connected in parallel, requiring operation to raise and lower the guardrails. Four stabilizer cylinders are also connected in parallel and require similar operation. Previously, due to the different loads on the two guardrail cylinders and the parallel system, asynchronous cylinder movement occurred, causing the guardrails on both sides to fail to raise and lower simultaneously, affecting usability. The four parallel stabilizer cylinders also have this problem. Existing structures often incorporate flow compensation valves in the return oil line to synchronize the parallel cylinders by controlling the flow rate, as seen in patent CN213870493U, a structure for a multi-actuator hydraulic system cylinder speed control system. However, flow control valves are very expensive, costing thousands of yuan per set, and their adjustment effect is not ideal. Patent CN116733802A, a synchronous hydraulic system and engineering machinery, also uses a synchronous structure, with synchronization components including pressure compensation parts and oil circuit control parts. The pressure compensation component can preset the pressure difference to ensure that the pressure oil flowing into the rodless chamber of the first cylinder from the first oil circuit is the same as the pressure oil flowing into the rodless chamber of the second cylinder from the second oil circuit. This achieves synchronous extension of the first and second cylinders, preventing damage to the cylinders caused by tilting or other abnormalities during the counterweighting process of the crane or other engineering equipment. The ultimate principle is still to adjust the flow rate of pressure oil entering the rodless chambers of the first and second cylinders; however, the synchronization structure is relatively complex and expensive, and can only adjust the state when the cylinder is extended. The bidirectional cylinder has oil entering through the rod chamber and returning through the rodless chamber, meaning there is no synchronization adjustment mechanism when the cylinder retracts. The rodless chamber damping is used to limit the retraction speed of the cylinder and maintain smooth movement. A low-cost and effective parallel cylinder synchronization control system for bridge inspection vehicles is needed. Summary of the Invention

[0003] This utility model provides a parallel hydraulic cylinder synchronous control system for a bridge inspection vehicle.

[0004] The purpose of this utility model is achieved in the following manner: a parallel hydraulic cylinder synchronous control system for a bridge inspection vehicle, comprising a hydraulic cylinder group and a reversing valve for connecting a hydraulic oil tank and the hydraulic cylinder group to realize oil supply and return to the hydraulic cylinder group. Each hydraulic cylinder group includes at least two hydraulic cylinders; the rodless chamber of each hydraulic cylinder in the same hydraulic cylinder group is connected in parallel to the rodless chamber main oil circuit through its respective rodless chamber branch, and the rod chamber of each hydraulic cylinder is connected in parallel to the rod chamber main oil circuit through its respective rod chamber branch; the rodless chamber main oil circuit and the rod chamber main oil circuit are respectively connected to different oil ports of the reversing valve; a first throttling connector is provided on each of the rod chamber branches, and a second throttling connector is provided on each of the rodless chamber branches to enable the hydraulic cylinders in the same group to operate synchronously.

[0005] The diameter of the throttling orifice of the first throttling connector on the rodless cavity branch is larger than the diameter of the throttling orifice of the second throttling connector on the rod cavity branch.

[0006] A bidirectional hydraulic lock is installed on both the rodless chamber branch and the rod chamber branch of the same hydraulic cylinder; the first throttle connector and the second throttle connector are installed on the same side of the bidirectional hydraulic lock.

[0007] The outlets of the first throttle connector and the second throttle connector are connected to the inlet A and inlet B of the bidirectional hydraulic lock, respectively; the outlets C1 and C2 of the bidirectional hydraulic lock are connected to the rod chamber and rodless chamber of the cylinder, respectively.

[0008] It also includes an on / off connected oil pump upper vehicle multi-way valve, the upper vehicle multi-way valve including at least two of the aforementioned reversing valves; one of the reversing valves of the upper vehicle multi-way valve controls the oil circuit of a cylinder group consisting of two parallel guardrail cylinders, and the other reversing valve controls the oil circuit of a cylinder group consisting of four parallel stabilizer cylinders.

[0009] It also includes a hydraulic pump connected to a hydraulic oil tank, the hydraulic pump being connected to the inlet P of a switching solenoid valve via a pipeline, the outlet A of the switching solenoid valve being connected to the inlet P of the upper vehicle multi-way valve; the outlet B and outlet C of the switching solenoid valve are respectively connected to other oil circuits.

[0010] Compared to existing technologies, the throttling connector in this invention has an extremely low cost, costing only a few yuan, thus significantly reducing costs while achieving the same synchronization effect. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structural principle of this utility model.

[0012] Among them, 1 is the hydraulic oil tank, 2 is the hydraulic pump, 3 is the switching solenoid valve, 4 is the upper vehicle multi-way valve, 5 is the first throttle connector, 6 is the two-way hydraulic lock, 7 is the guardrail cylinder, 8 is the stabilizer cylinder, and 9 is the second throttle connector. Detailed Implementation

[0013] In this utility model, unless otherwise expressly specified and limited, the technical terms used in this application shall have the ordinary meaning understood by those skilled in the art. Terms such as "connected," "linked," "fixed," and "set" shall be interpreted broadly, referring to fixed connections, detachable connections, or integral connections; direct connections or indirect connections via an intermediate medium; mechanical connections or electrical connections. Unless otherwise expressly specified and limited, "above" or "below" a second feature may mean that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," or "over" a second feature may mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," or "under" a second feature may mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature. Relational terms such as "first," "second," etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The terms used in the description, such as “center,” “lateral,” “longitudinal,” “length,” “width,” “thickness,” “height,” “front,” “rear,” “left,” “right,” “up,” “down,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” “outer,” “axial,” “radial,” “circumferential,” “clockwise,” and “counterclockwise,” indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation.

[0014] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. Figure 1As shown, a parallel cylinder synchronous control system for a bridge inspection vehicle includes cylinder groups and a directional valve for connecting a hydraulic oil tank 1 and the cylinder groups to supply and return oil to the cylinder groups. Each cylinder group includes at least two cylinders; the rodless chamber of each cylinder in the same group is connected in parallel to the rodless chamber main oil circuit through its respective rodless chamber branch, and the rod chamber of each cylinder is connected in parallel to the rod chamber main oil circuit through its respective rod chamber branch; the rodless chamber main oil circuit and the rod chamber main oil circuit are respectively connected to different ports of the directional valve; a first throttling connector 5 is provided on each rod chamber branch, and a second throttling connector 9 is provided on each rodless chamber branch to enable synchronous operation of the cylinders in the same cylinder group. The cylinders are double-acting cylinders, and the various ports of the directional valve can be switched on and off to supply oil to the hydraulic pump 2, the hydraulic oil tank 1, the rodless chamber main oil circuit, and the rod chamber main oil circuit. By switching positions using a directional valve, the hydraulic cylinder can switch between states where the rodless chamber is supplied with oil, the rod chamber returns oil, and the piston rod is extended; between states where the rod chamber is supplied with oil, the rodless chamber returns oil, and the piston rod is retracted; and between a locked intermediate stop state. In this invention, the specifications and structures of the cylinders in the same cylinder group are identical. However, because the loads and resistances of each cylinder are not exactly the same, when controlled by the same directional valve, the hydraulic oil in the parallel cylinders preferentially enters the cylinder with the lower load, which greatly affects the extension speed of the piston rod and causes asynchrony. In this invention, throttling connectors are provided in the rodless chamber branch and the rod chamber branch. When the rod chamber returns oil, the pressure of the returning oil in the rod chamber increases due to the presence of the first throttling connector 5, forming back pressure. The total load is the cylinder's own load plus the load caused by the back pressure. Because the load of the back pressure is much greater than the cylinder's own load, the difference between the original loads of different cylinders is significantly smaller relative to the total load after back pressure, and the extension speeds of the parallel cylinders are basically synchronized. When the rodless chamber returns oil, the retraction speed of the parallel cylinders remains essentially synchronized due to the presence of the second throttling connector 9. The two first throttling connectors 5 and the two second throttling connectors 9 are identical in specifications. The specifications of the first throttling connectors 5 and the second throttling connectors 9, specifically the difference in their throttling orifices, are determined by the area of ​​the rod-side and rodless chambers of different cylinders and can be the same or different. Existing flow distribution valves cost thousands and throttling valves cost hundreds; however, the throttling connector in this invention is extremely inexpensive, costing only a few yuan, thus significantly reducing costs while achieving the same synchronization effect.

[0015] Preferably, the diameter of the throttling orifice of the first throttling connector 5 on the rodless cavity branch is larger than the diameter of the throttling orifice of the second throttling connector 9 on the rod cavity branch. The cross-section of the rodless cavity of the cylinder is larger than that of the rod cavity, and the larger diameter of the first throttling connector 5 compared to the second throttling connector 9 further ensures that the extension and retraction speeds of the cylinder are the same. The specific difference can be calculated and determined experimentally based on the specifications and dimensions of different cylinders. Taking the guardrail cylinder 7 and the stabilizer cylinder as examples, the orifice diameter of the first throttling head of the guardrail cylinder 7 can be 0.8 mm, and the orifice diameter of the second throttling connector 9 can be 0.6 mm. The orifice diameter of the first throttling head of the stabilizer cylinder 8 can be 1.2 mm, and the orifice diameter of the second throttling connector 9 can be 0.8 mm. Of course, the first throttling connector 5 and the second throttling connector 9 can also be the same; slightly reducing the orifice diameter to increase the back pressure can reduce the difference in piston rod extension and retraction speeds when the throttling connectors have the same orifice diameter, thus achieving basic synchronization; however, this will reduce the extension and retraction speeds.

[0016] Preferably, a bidirectional hydraulic lock 6 is installed on both the rodless chamber branch and the rod chamber branch of the same hydraulic cylinder; the first throttle connector 5 and the second throttle connector 9 are installed on the same side of the bidirectional hydraulic lock 6. The first throttle connector 5 and the second throttle connector 9 can be installed on either side of the bidirectional hydraulic lock 6, for example, between the bidirectional hydraulic lock 6 and the hydraulic cylinder, or on the side of the bidirectional hydraulic lock 6 away from the hydraulic cylinder. However, it is preferred that the first throttle connector 5 and the second throttle connector 9 are located on the same side.

[0017] The outlets of the first throttling connector 5 and the second throttling connector 9 are connected to inlet A and inlet B of the bidirectional hydraulic lock 6, respectively; the outlets C1 and C2 of the bidirectional hydraulic lock 6 are connected to the rod-side chamber and rodless chamber of the cylinder, respectively. The principle and structure of the bidirectional hydraulic lock 6 are existing technologies and will not be described in detail here.

[0018] It also includes an on / off multi-way valve 4 connected to the oil pump, the multi-way valve 4 comprising at least two directional valves; one of the directional valves controls the oil circuit of a cylinder group consisting of two parallel guardrail cylinders 7, and the other directional valve controls the oil circuit of a cylinder group consisting of four parallel stabilizer cylinders 8. The cylinder group consisting of two guardrail cylinders 7 includes two rod-side branches and two rodless-side branches, and is respectively equipped with a first throttle connector 5 and a second throttle connector 9; each guardrail cylinder 7 is also equipped with a bidirectional hydraulic lock 6. The four stabilizer cylinders 8 include four rod-side branches and four rodless-side branches, and are respectively equipped with a first throttle connector 5 and a second throttle connector 9; each stabilizer cylinder 8 is also equipped with a bidirectional hydraulic lock 6. The directional valve is preferably a solenoid valve, including three positions: a stop position and two supply / return positions. The specifications and dimensions of the first and second throttling connectors of the stabilizer cylinder 8 and the corresponding first and second throttling connectors of the guardrail cylinder 7 may be the same or different.

[0019] It also includes a hydraulic pump 2 connected to the hydraulic oil tank 1. The hydraulic pump 2 is connected to the inlet P of the switching solenoid valve 3 via a pipeline. The outlet A of the switching solenoid valve 3 is connected to the inlet P of the upper multi-way valve 4. The outlets B and C of the switching solenoid valve 3 lead to other oil circuits, respectively. Specifically, the switching solenoid valve 3 includes an inlet P, an outlet A, an outlet B, an outlet C, and a return port T. The switching solenoid valve 3 may include two tandem two-position four-way solenoid valves. When the inlet P is connected to the outlet A, hydraulic oil flows to the upper multi-way valve 4, and other outlets are closed. When the inlet P is connected to the outlet B or outlet C, the oil circuit to outlet A is closed. It also includes commonly used components such as filters, which will not be described in detail.

[0020] In specific implementation: the suction port of the hydraulic pump 2 is connected to the hydraulic oil tank 1, and the outlet port is connected to the inlet P of the switching solenoid valve 3; the A, B, and C outlet ports of the switching solenoid valve 3 are respectively connected to the upper vehicle multi-way valve 4 and other oil circuit systems. The upper vehicle multi-way valve 4 includes a control valve (i.e., a reversing valve) for controlling the extension and retraction of the guardrail cylinder 7, a control valve (reversing valve) for the stabilizer cylinder 8, and other cylinder control valves. When the bridge inspection vehicle needs to operate the guardrail to lower, the hydraulic pump 2 starts working, the solenoid switching valves 3 are not energized, and the oil circuit defaults to the upper vehicle multi-way valve 4. By operating the reversing valve corresponding to the guardrail cylinder of the upper vehicle multi-way valve 4 and moving the handle upward, the pressurized oil enters the inlet A of the two-way hydraulic lock 6 through the first throttle joint 5, flows out from the outlet C1 of the two-way hydraulic lock, and enters the rod chamber of the guardrail cylinder 7. The hydraulic oil in the rodless chamber of the guardrail cylinder 7 enters through the outlet C2 of the two-way hydraulic lock 6, flows out through the inlet B, enters the second throttle joint 9, and returns to the hydraulic oil tank 1 from the upper vehicle multi-way valve 4. When the bridge inspection vehicle needs to operate the guardrail, hydraulic pump 2 starts working, and switching valves 3 are not energized. The oil circuit defaults to the upper multi-way valve 4. Operate the directional valve corresponding to the guardrail cylinder on the upper multi-way valve 4, and move the handle downwards. Pressurized oil enters the inlet B of the two-way hydraulic lock 6 through the second throttle connector 9, flows out from the outlet C2 of the two-way hydraulic lock, and enters the rodless chamber of the guardrail cylinder 7. Hydraulic oil in the rod chamber of the guardrail cylinder 7 enters through the outlet C1 of the two-way hydraulic lock 6, flows out through the inlet A, enters the first throttle connector 5, and returns to the hydraulic oil tank 1 from the upper multi-way valve 4. When operating the stabilizer cylinder 8 to retract, the steps are the same as above, except that the handle needs to be moved to operate the directional valve corresponding to the stabilizer cylinder 8 on the upper multi-way valve 4.

[0021] This invention uses throttling connectors of different orifice diameters in the rod-side and rodless-side cylinder branches to create back pressure during cylinder operation, balancing load differences and synchronizing the operation of multiple parallel cylinders. Compared to conventional methods using flow distribution valves, this significantly reduces design costs and provides better performance. By solving the problem of asynchronous guardrail cylinder operation, it addresses the issues of non-parallelism of the guardrails and vehicle swaying caused by asynchronous stabilizer cylinder operation.

[0022] The technical features of the embodiments described above can be combined in any way, and as long as there is no contradiction in the combination of these technical features, they should all be considered within the scope of this specification. Without departing from the overall concept of this utility model, any equivalent substitutions or modifications made to the technical solution of this utility model, as well as any changes and improvements, should also be considered within the protection scope of this utility model.

Claims

1. A parallel hydraulic cylinder synchronous control system for a bridge inspection vehicle, comprising a hydraulic cylinder assembly and a directional valve for connecting a hydraulic oil tank and the hydraulic cylinder assembly to achieve oil supply and return to the hydraulic cylinder assembly, characterized in that: Each set of hydraulic cylinders includes at least two hydraulic cylinders; the rodless chamber of each cylinder in the same set is connected in parallel to the rodless chamber main oil circuit through its respective rodless chamber branch, and the rod chamber of each cylinder is connected in parallel to the rod chamber main oil circuit through its respective rod chamber branch; the rodless chamber main oil circuit and the rod chamber main oil circuit are respectively connected to different oil ports of the reversing valve; a first throttling connector is provided on each of the rod chamber branches, and a second throttling connector is provided on each of the rodless chamber branches to enable the hydraulic cylinders in the same set to operate synchronously.

2. The parallel hydraulic cylinder synchronous control system for a bridge inspection vehicle according to claim 1, characterized in that: The diameter of the throttling orifice of the first throttling connector on the rodless cavity branch is larger than the diameter of the throttling orifice of the second throttling connector on the rod cavity branch.

3. The parallel hydraulic cylinder synchronous control system for a bridge inspection vehicle according to claim 1, characterized in that: A bidirectional hydraulic lock is installed on both the rodless chamber branch and the rod chamber branch of the same hydraulic cylinder; the first throttle connector and the second throttle connector are installed on the same side of the bidirectional hydraulic lock.

4. The parallel hydraulic cylinder synchronous control system for a bridge inspection vehicle according to claim 3, characterized in that: The outlets of the first throttle connector and the second throttle connector are connected to the inlet A and inlet B of the bidirectional hydraulic lock, respectively; the outlets C1 and C2 of the bidirectional hydraulic lock are connected to the rod chamber and rodless chamber of the cylinder, respectively.

5. A parallel hydraulic cylinder synchronous control system for a bridge inspection vehicle according to any one of claims 1-4, characterized in that: It also includes an on / off connected oil pump upper vehicle multi-way valve, the upper vehicle multi-way valve including at least two of the aforementioned reversing valves; one of the reversing valves of the upper vehicle multi-way valve controls the oil circuit of a cylinder group consisting of two parallel guardrail cylinders, and the other reversing valve controls the oil circuit of a cylinder group consisting of four parallel stabilizer cylinders.

6. The parallel hydraulic cylinder synchronous control system for a bridge inspection vehicle according to claim 5, characterized in that: It also includes a hydraulic pump connected to a hydraulic oil tank, the hydraulic pump being connected to the inlet P of a switching solenoid valve via a pipeline, the outlet A of the switching solenoid valve being connected to the inlet P of the upper vehicle multi-way valve; the outlet B and outlet C of the switching solenoid valve are respectively connected to other oil circuits.

Images