Concrete distribution equipment and hydraulic control system and control method thereof

Abstract

The invention provides a concrete distribution equipment hydraulic control system which comprises a hydraulic oil tank, an oil supply pump unit, an oil pressing main pipeline, an oil return main pipeline and at least one hydraulic execution unit. Each hydraulic execution unit comprises a hydraulic oil cylinder and a control valve group, and the control valve group is arranged close to the hydraulic oil cylinder or integrated on the hydraulic oil cylinder; the control valve set comprises a main reversing valve, a standby reversing valve and a balance valve set, an oil inlet of the main reversing valve and an oil inlet of the standby reversing valve are both connected with the oil pressing main pipeline, and an oil return opening of the main reversing valve and an oil return opening of the standby reversing valve are both connected with the oil return main pipeline. An oil outlet of the main reversing valve and an oil outlet of the standby reversing valve are connected with the hydraulic oil cylinder through the balance valve set. The invention further provides a control method of the hydraulic control system of the concrete distribution equipment and the concrete distribution equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete distribution equipment, and in particular to concrete distribution equipment and a hydraulic control system and a control method thereof. Background Art

[0002] Concrete placing equipment is the terminal equipment for pumping concrete, which is generally a concrete pump truck, a concrete placing machine (for details, please refer to patents such as CN204001766U and CN114704096A), etc. Its function is to send the concrete pressed by the pump to the formwork of the component to be cast through the pipeline. The hydraulic control system of the concrete placing equipment is the core part that controls the movement of its boom, and various placing actions are completed by controlling the movement of the boom.

[0003] like Figure 1 As shown, the existing hydraulic control system of concrete placing equipment generally includes a hydraulic oil tank 91, a hydraulic oil pump 92, a reversing valve group 93, a balancing valve group 94 and an oil cylinder 95 (arm oil cylinder). The hydraulic oil pump 92 draws hydraulic oil from the hydraulic oil tank 91, and then pumps the hydraulic oil to the oil cylinder 95 through the reversing valve group 93 and the balancing valve group 94 in sequence, thereby driving the oil cylinder 95 to work, and then driving the arm to move. Among them, the hydraulic oil tank 91, the hydraulic oil pump 92 and the reversing valve group 93 are all arranged at the unloading position of the concrete placing equipment (i.e., the chassis position), the balancing valve group 94 and the oil cylinder 95 are both arranged on the arm, and the balancing valve group 94 and the oil cylinder 95 are integrated. The reversing valve group 93 adopts a multi-way valve, which includes a plurality of reversing valves 931 arranged in parallel, and each reversing valve 931 is connected to the corresponding balancing valve group 94 and the oil cylinder 95 through a pressure oil pipeline 96 and a return oil pipeline 97. One end of the oil pressure pipeline 96 and the oil return pipeline 97 is connected to the reversing valve 931 located at the chassis, and the other end is laid along the boom to the corresponding oil cylinder 95. However, the existing hydraulic control system of concrete placing equipment has the following problems:

[0004] 1. Since the chassis is far away from the boom, the reversing valve group 93 is arranged at the chassis, and the oil cylinder 95 is arranged on the boom, the distance between the reversing valve group 93 (control element) and the oil cylinder 95 (actuator) is far, which leads to a slow response speed of the oil cylinder 95.

[0005] At the same time, since the reversing valve group 93 adopts a multi-way valve, each reversing valve 931 is connected to the corresponding balance valve group 94 and the oil cylinder 95 through the oil pressure pipeline 96 and the oil return pipeline 97, resulting in a large number of pipelines, long pipeline distances, heavy weight, affecting the spatial layout, and a small pipeline diameter. During the operation of the boom, the hydraulic system has large pressure losses and along-the-way losses, and low efficiency.

[0006] 2. Since the boom is usually operated at high altitude, the temperature of the hydraulic oil in the oil pressure pipeline 96 and the oil return pipeline 97 is close to the ambient temperature, so the oil temperature in the pipeline is greatly affected by the ambient temperature. Especially in a low temperature environment, the cold oil in the pipeline cannot be quickly exchanged, resulting in slow system response, large pressure loss, and low efficiency. However, the current hydraulic control system cannot sense the oil temperature in the oil pressure pipeline 96, and cannot handle the abnormal oil temperature in time.

[0007] 3. Each oil cylinder 95 is controlled by a single reversing valve 931. When the reversing valve 931 fails, the boom cannot be operated in an emergency, which poses a great safety hazard. Summary of the invention

[0008] The purpose of the present invention is to provide a hydraulic control system for concrete placing equipment, which can improve the response speed of the hydraulic cylinder, save the number of pipelines, and reduce the system pressure loss; at the same time, a spare reversing valve is adopted to perform emergency operation on the boom when the main reversing valve fails.

[0009] The present invention provides a hydraulic control system for concrete placing equipment, comprising a hydraulic oil tank, an oil supply pump unit, an oil pressure main line, an oil return main line and at least one hydraulic actuator unit; one end of the oil pressure main line is connected to the hydraulic oil tank, the oil supply pump unit is arranged on the oil pressure main line; one end of the oil return main line is connected to the hydraulic oil tank;

[0010] Each of the hydraulic actuator units includes a hydraulic cylinder and a control valve group, wherein the control valve group is arranged close to the hydraulic cylinder, or the control valve group is integrated on the hydraulic cylinder; the control valve group includes a main reversing valve, a spare reversing valve and a balancing valve group, the oil inlet of the main reversing valve and the oil inlet of the spare reversing valve are respectively connected to the main oil pressure line, the oil return port of the main reversing valve and the oil return port of the spare reversing valve are respectively connected to the main oil return line, and the oil outlet of the main reversing valve and the oil outlet of the spare reversing valve are respectively connected to the hydraulic cylinder through the balancing valve group.

[0011] Further, the balancing valve group includes a first balancing valve, a second balancing valve, a first non-return valve and a second non-return valve, the first balancing valve and the first non-return valve are arranged in reverse parallel, and the second balancing valve and the second non-return valve are arranged in reverse parallel; the first oil outlet of the main reversing valve and the first oil outlet of the standby reversing valve are both connected to the outlet of the first balancing valve and the inlet of the first non-return valve, and the inlet of the first balancing valve and the outlet of the first non-return valve are both connected to an oil port of the hydraulic cylinder; the second oil outlet of the main reversing valve and the second oil outlet of the standby reversing valve are both connected to the outlet of the second balancing valve and the inlet of the second non-return valve, and the inlet of the second balancing valve and the outlet of the second non-return valve are both connected to another oil port of the hydraulic cylinder.

[0012] Furthermore, the first balancing valve and the second balancing valve are both pilot balancing valves; the control oil port of the first balancing valve is connected to the second oil outlet of the main reversing valve and the second oil outlet of the standby reversing valve, and the control oil port of the second balancing valve is connected to the first oil outlet of the main reversing valve and the first oil outlet of the standby reversing valve.

[0013] Furthermore, the concrete placing equipment hydraulic control system further comprises an oil temperature detection unit and a control unit, wherein the oil temperature detection unit is used to detect the oil temperature of the hydraulic oil in the hydraulic oil tank and the oil temperature of the hydraulic oil in the oil pressure main line; a radiator for cooling the hydraulic oil is provided on the oil return main line;

[0014] The oil pressure main line and the oil return main line are connected via a circulation line, and a switch valve is provided on the circulation line; the control unit is simultaneously connected to the oil temperature detection unit, the switch valve and the radiator signal, and the control unit is used to control the opening and closing of the switch valve and the radiator according to the oil temperature information detected by the oil temperature detection unit.

[0015] Furthermore, the oil temperature detection unit includes a main line temperature sensor and an oil tank temperature sensor, the oil tank temperature sensor is connected to the hydraulic oil tank, and the oil tank temperature sensor is used to detect the temperature of the hydraulic oil in the hydraulic oil tank; the main line temperature sensor is arranged on the oil pressure main line or the circulation line, and the main line temperature sensor is used to detect the temperature of the hydraulic oil in the oil pressure main line.

[0016] Further, the main line temperature sensor is arranged at the end of the oil pressure main line away from the hydraulic oil tank; or, the circulation pipeline is connected to the ends of the oil pressure main line and the oil return main line away from the hydraulic oil tank, and the main line temperature sensor is arranged on the circulation pipeline.

[0017] Furthermore, there are multiple hydraulic actuator units, and the multiple hydraulic actuator units are arranged in parallel in sequence; the oil pressure main line and the oil return main line are respectively connected to the multiple hydraulic actuator units, and the end of the oil pressure main line and the end of the oil return main line are connected to the hydraulic actuator unit at the tail end, and the circulation pipeline is connected to the end of the oil pressure main line and the end of the oil return main line.

[0018] Furthermore, the concrete placing equipment hydraulic control system also includes a pressure detection unit and a relief valve, the pressure detection unit is used to detect the operating load pressure of the hydraulic cylinder and the outlet pressure of the oil supply pump unit; the inlet of the relief valve is connected to the oil pressure main line, and the outlet of the relief valve is connected to the oil return main line; the control unit is also connected to the pressure detection unit and the relief valve signal, and the control unit is also used to control the relief setting value of the relief valve according to the pressure signal detected by the pressure detection unit and the oil temperature information detected by the oil temperature detection unit.

[0019] Furthermore, the main reversing valve is a proportional reversing valve, and the control unit is also signal-connected to the main reversing valve and the oil supply pump unit; the control unit is also used to control the opening of the main reversing valve and the oil supply flow of the oil supply pump unit according to the hydraulic oil demand flow of the boom movement.

[0020] The present invention also provides a control method for the hydraulic control system of the concrete placing equipment, the control method comprising:

[0021] When the oil temperature detection unit detects that the hydraulic oil temperature in the oil pressure main line is lower than the set value or the hydraulic oil temperature in the hydraulic oil tank, the control unit controls the switch valve to open and the radiator to close, so that the hydraulic oil in the hydraulic oil tank is circulated back to the hydraulic oil tank through the oil pressure main line, the circulation line and the oil return main line in sequence;

[0022] When the oil temperature detection unit detects that the temperature of the hydraulic oil in the hydraulic oil tank is higher than the control value, the control unit controls the switch valve and the radiator to open, so that the hydraulic oil in the hydraulic oil tank circulates back to the hydraulic oil tank through the oil pressure main line, the circulation line, the oil return main line and the radiator in sequence.

[0023] The present invention also provides a concrete distribution equipment, including the above-mentioned concrete distribution equipment hydraulic control system, the hydraulic cylinder and the control valve group in each hydraulic actuator unit are arranged on the arm of the concrete distribution equipment; the number of the hydraulic actuator units is multiple, and the multiple hydraulic actuator units are arranged in parallel in sequence, and the oil pressure main line and the oil return main line are respectively connected to the multiple hydraulic actuator units.

[0024] In the concrete placing equipment hydraulic control system provided by the present invention, the control valve group of each hydraulic actuator unit adopts a distributed arrangement, that is, the control valve group of each hydraulic actuator unit is arranged close to the hydraulic cylinder or integrated on the hydraulic cylinder, thereby shortening the distance between the control valve group and the hydraulic cylinder, and improving the response speed of the hydraulic cylinder; moreover, the control valve group of each hydraulic actuator unit can be connected in parallel to the oil pressure main line and the oil return main line, that is, the same main line is used to be connected in series to the hydraulic cylinders on each section arm respectively, and there is no need to lay a long oil pressure pipeline and oil return pipeline between each reversing valve and the corresponding cylinder, thereby saving the number of pipelines, and at the same time, the oil pressure main line and the oil return main line can adopt large-diameter pipelines, thereby reducing system pressure loss and further improving the response speed of the hydraulic cylinder.

[0025] At the same time, the control valve group is provided with a main reversing valve and a spare reversing valve. The main reversing valve is a commonly used reversing valve. When the main reversing valve fails, the spare reversing valve can replace the main reversing valve to control the operation of the hydraulic cylinder, thereby enabling emergency operation of the boom and improving the safety of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of a hydraulic control system of concrete placing equipment in the prior art.

[0027] Figure 2 Schematic diagram of the structure of the hydraulic control system of concrete placing equipment in an embodiment of the present invention.

[0028] Figure 3 Schematic diagram of control logic of a hydraulic control system of concrete placing equipment in an embodiment of the present invention.

[0029] Figure 4 It is a structural schematic diagram of a hydraulic control system of concrete placing equipment in another embodiment of the present invention.

[0030] Figure 5 Schematic diagram of control logic of a hydraulic control system for concrete placing equipment in another embodiment of the present invention. DETAILED DESCRIPTION

[0031] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0032] The terms "first", "second", "third", "fourth" and the like (if any) in the description and claims of the present invention are used to distinguish similar objects and are not necessarily used to describe a particular sequence or order.

[0033] The directional words such as up, down, left, right, front, back, top, bottom, etc. (if any) involved in the specification and claims of the present invention are defined by the positions of the structures in the drawings and the positions of the structures relative to each other, and are only for the clarity and convenience of expressing the technical solution. It should be understood that the use of directional words should not limit the scope of protection claimed in this application.

[0034] like Figure 2 and Figure 3 As shown, the hydraulic control system of concrete placing equipment provided by the embodiment of the present invention comprises a hydraulic oil tank 1, an oil supply pump unit 10, an oil pressure main line 2, an oil return main line 3 and at least one hydraulic actuator unit 4. The hydraulic oil tank 1 is used to store hydraulic oil, the oil supply pump unit 10 is used to absorb and pump the hydraulic oil in the hydraulic oil tank 1, the oil pressure main line 2 is used to transport the hydraulic oil to the hydraulic actuator unit 4, and the oil return main line 3 is used to return the hydraulic oil to the hydraulic oil tank 1. One end of the oil pressure main line 2 is connected to the hydraulic oil tank 1, and the oil supply pump unit 10 is arranged on the oil pressure main line 2. One end of the oil return main line 3 is connected to the hydraulic oil tank 1.

[0035] Each hydraulic actuator unit 4 includes a hydraulic cylinder 41 (i.e., an arm cylinder disposed on the arm) and a control valve group (not numbered in the figure). The hydraulic cylinder 41 is connected to the main oil pressure line 2 and the main oil return line 3 through the control valve group. The control valve group is disposed close to the hydraulic cylinder 41, or the control valve group is integrated on the hydraulic cylinder 41 (i.e., the control valve group is disposed on the hydraulic cylinder 41). The control valve group includes a main reversing valve 42, a spare reversing valve 43 and a balance valve group. The main reversing valve 42 and the spare reversing valve 43 are disposed in parallel; the oil inlet of the main reversing valve 42 and the oil inlet of the spare reversing valve 43 are respectively connected to the main oil pressure line 2, the oil return port of the main reversing valve 42 and the oil return port of the spare reversing valve 43 are respectively connected to the main oil return line 3, and the oil outlet of the main reversing valve 42 and the oil outlet of the spare reversing valve 43 are respectively connected to the hydraulic cylinder 41 through the balance valve group.

[0036] In the concrete placing equipment hydraulic control system provided in the present embodiment, the control valve group of each hydraulic actuator unit 4 is arranged in a distributed manner, that is, the control valve group of each hydraulic actuator unit 4 is arranged close to the hydraulic cylinder 41 or integrated on the hydraulic cylinder 41 (instead of adopting a multi-way valve to integrate multiple reversing valves together), thereby shortening the distance between the control valve group and the hydraulic cylinder 41 and improving the response speed of the hydraulic cylinder 41; moreover, the control valve group of each hydraulic actuator unit 4 can be connected in parallel to the oil pressure main line 2 and the oil return main line 3, that is, the same main line is used to be connected in series to the hydraulic cylinder 41 on each section arm, and there is no need to lay a long oil pressure pipeline and oil return pipeline between each reversing valve and the corresponding cylinder, thereby saving the number of pipelines, and at the same time, the oil pressure main line 2 and the oil return main line 3 can adopt large-diameter pipelines, thereby reducing system pressure loss and further improving the response speed of the hydraulic cylinder 41.

[0037] At the same time, a main reversing valve 42 and a spare reversing valve 43 are provided in the control valve group. The main reversing valve 42 is a commonly used reversing valve. When the main reversing valve 42 fails, the spare reversing valve 43 can replace the main reversing valve 42 to control the operation of the hydraulic cylinder 41, thereby enabling emergency operation of the boom and improving the safety of the system.

[0038] like Figure 2 and Figure 3 As shown, as an embodiment, the hydraulic control system of the concrete placing equipment further includes an oil temperature detection unit 5 and a control unit 7, and a radiator 31 for cooling the hydraulic oil is provided on the return oil main line 3. The pressure oil main line 2 and the return oil main line 3 are connected through a circulation line 20, and a switch valve 21 is provided on the circulation line 20, and the switch valve 21 is used to open or close the circulation line 20. The oil temperature detection unit 5 is used to detect the oil temperature of the hydraulic oil in the hydraulic oil tank 1 and the oil temperature of the hydraulic oil in the pressure oil main line 2; the control unit 7 is simultaneously connected to the oil temperature detection unit 5, the switch valve 21 and the radiator 31 by signal, and the control unit 7 is used to control the opening and closing of the switch valve 21 and the radiator 31 according to the oil temperature information detected by the oil temperature detection unit 5.

[0039] Specifically, the oil pressure main line 2 and the oil return main line 3 are connected by setting a circulation line 20, and a switch valve 21 is set on the circulation line 20; when the oil temperature detection unit 5 detects that the hydraulic oil temperature in the oil pressure main line 2 is lower than the set value or the hydraulic oil temperature in the hydraulic oil tank 1, the control unit 7 controls the switch valve 21 to open and the radiator 31 to close, so that the hydraulic oil in the hydraulic oil tank 1 is circulated back to the hydraulic oil tank 1 through the oil pressure main line 2, the circulation line 20 and the oil return main line 3 in sequence, so that the cold oil in the pipeline is quickly circulated and exchanged, and the hot oil in the hydraulic oil tank 1 is quickly circulated and transferred to the pipeline, thereby improving the system response speed, reducing the system pressure loss, and improving work efficiency. When the oil temperature detection unit 5 detects that the hydraulic oil temperature in the hydraulic oil tank 1 is higher than the control value, the control unit 7 controls the switch valve 21 and the radiator 31 to open, so that the hydraulic oil in the hydraulic oil tank 1 circulates back to the hydraulic oil tank 1 through the oil pressure main line 2, the circulation line 20, the return oil main line 3 and the radiator 31 in sequence, so that the hot oil circulates in the radiator 31 and the pipeline to dissipate heat, thereby improving the heat dissipation efficiency and avoiding abnormal operation caused by excessive oil temperature (in normal operation, the switch valve 21 is in a closed state). The control unit 7, the oil temperature detection unit 5, the radiator 31 and the switch valve 21 cooperate to control the oil temperature in the pipeline and the hydraulic oil tank 1.

[0040] like Figure 2 As shown, as an embodiment, the balancing valve group includes a first balancing valve 44, a second balancing valve 45, a first check valve 46 and a second check valve 47. The first balancing valve 44 and the first check valve 46 are arranged in reverse parallel (that is, the inlet of the first balancing valve 44 is connected to the outlet of the first check valve 46, and the outlet of the first balancing valve 44 is connected to the inlet of the first check valve 46), and the second balancing valve 45 and the second check valve 47 are arranged in reverse parallel. The first oil outlet of the main reversing valve 42 and the first oil outlet of the standby reversing valve 43 are both connected to the outlet of the first balancing valve 44 and the inlet of the first check valve 46, and the inlet of the first balancing valve 44 and the outlet of the first check valve 46 are both connected to an oil port of the hydraulic cylinder 41. The second oil outlet of the main reversing valve 42 and the second oil outlet of the backup reversing valve 43 are both connected to the outlet of the second balancing valve 45 and the inlet of the second non-return valve 47, and the inlet of the second balancing valve 45 and the outlet of the second non-return valve 47 are both connected to another oil port of the hydraulic cylinder 41. Among them, the two oil ports of the hydraulic cylinder 41 are the rod chamber oil port and the rodless chamber oil port, respectively. The rod chamber oil port is connected to the rod chamber of the hydraulic cylinder 41, and the rodless chamber oil port is connected to the rodless chamber of the hydraulic cylinder 41 (in this embodiment, the inlet of the first balancing valve 44 and the outlet of the first non-return valve 46 are both connected to the rodless chamber oil port of the hydraulic cylinder 41, and the inlet of the second balancing valve 45 and the outlet of the second non-return valve 47 are both connected to the rod chamber oil port of the hydraulic cylinder 41). Of course, in other embodiments, the balancing valve group can also use other valve combinations.

[0041] like Figure 2 As shown, as an embodiment, the first balancing valve 44 and the second balancing valve 45 are both pilot-operated balancing valves; the control oil port of the first balancing valve 44 is connected to the second oil outlet of the main reversing valve 42 and the second oil outlet of the standby reversing valve 43, and the control oil port of the second balancing valve 45 is connected to the first oil outlet of the main reversing valve 42 and the first oil outlet of the standby reversing valve 43. Of course, in other embodiments, the first balancing valve 44 and the second balancing valve 45 may also be other types of balancing valves, such as electrically controlled balancing valves.

[0042] Specifically, during operation, when the main reversing valve 42 is opened, the oil inlet of the main reversing valve 42 is connected to its first oil outlet, and the oil return port of the main reversing valve 42 is connected to its second oil outlet, the hydraulic oil in the oil pressure main line 2 passes through the first oil outlet of the main reversing valve 42 and the first one-way valve 46 in turn to reach the rodless chamber of the hydraulic cylinder 41, and at the same time the second balancing valve 45 is opened, so that the hydraulic oil in the rod chamber of the hydraulic cylinder 41 flows back to the oil return main line 3 through the second balancing valve 45 and the second oil outlet of the main reversing valve 42 in turn, and at this time the piston rod of the hydraulic cylinder 41 extends. When the main reversing valve 42 is opened, the oil inlet of the main reversing valve 42 is connected to its second oil outlet, and the oil return port of the main reversing valve 42 is connected to its first oil outlet, the hydraulic oil in the oil pressure main line 2 sequentially passes through the second oil outlet of the main reversing valve 42 and the second one-way valve 47 to reach the rod chamber of the hydraulic cylinder 41. At the same time, the first balancing valve 44 is opened, so that the hydraulic oil in the rodless chamber of the hydraulic cylinder 41 flows back to the oil return main line 3 through the first balancing valve 44 and the first oil outlet of the main reversing valve 42 in sequence. At this time, the piston rod of the hydraulic cylinder 41 retracts.

[0043] like Figure 2 and Figure 3 As shown, as an embodiment, the oil temperature detection unit 5 includes a main line temperature sensor 51 and an oil tank temperature sensor 52, and the control unit 7 is simultaneously connected to the main line temperature sensor 51 and the oil tank temperature sensor 52. The oil tank temperature sensor 52 is connected to the hydraulic oil tank 1, and the oil tank temperature sensor 52 is used to detect the temperature of the hydraulic oil in the hydraulic oil tank 1. The main line temperature sensor 51 is arranged on the oil pressure main line 2 or the circulation line 20, and the main line temperature sensor 51 is used to detect the temperature of the hydraulic oil in the oil pressure main line 2.

[0044] like Figure 2As shown, as an embodiment, the circulation pipeline 20 is connected to the ends of the pressure oil main pipeline 2 and the return oil main pipeline 3 away from the hydraulic oil tank 1, and the main pipeline temperature sensor 51 is arranged on the circulation pipeline 20. As another embodiment, the main pipeline temperature sensor 51 is arranged at the end of the pressure oil main pipeline 2 away from the hydraulic oil tank 1. Since the pressure oil main pipeline 2 is generally arranged long, the hydraulic oil temperature at various positions in the pipeline is inconsistent (generally, the closer to the hydraulic oil tank 1, the higher the hydraulic oil temperature, and the farther away from the hydraulic oil tank 1, the lower the hydraulic oil temperature). In this embodiment, the main pipeline temperature sensor 51 is used to detect the hydraulic oil temperature at the end of the pressure oil main pipeline 2, so that its temperature detection result can represent the lowest temperature level of the hydraulic oil in the pipeline, thereby facilitating the temperature control of the low-temperature hydraulic oil in the pipeline (since the pressure oil main pipeline 2 is arranged on the boom, and the height of the boom is relatively high, the hydraulic oil in the pressure oil main pipeline 2 is prone to low temperature, which increases the viscosity of the hydraulic oil in the pipeline and causes a large pressure loss).

[0045] like Figure 2 As shown, as an implementation method, the number of hydraulic actuator units 4 is multiple, and multiple hydraulic actuator units 4 are arranged in parallel in sequence; the main oil pressure line 2 and the main oil return line 3 are respectively connected to multiple hydraulic actuator units 4 (specifically connected to the control valve group in the hydraulic actuator unit 4), that is, the same main line is used to be connected in series to the hydraulic cylinders 41 on each section arm, and there is no need to lay long oil pressure lines and oil return lines between each reversing valve and the corresponding cylinder, thereby saving the number of pipelines. At the same time, the end of the main oil pressure line 2 and the end of the main oil return line 3 are connected to the hydraulic actuator unit 4 at the tail end, and the circulation line 20 is connected to the end of the main oil pressure line 2 and the end of the main oil return line 3, thereby avoiding the setting of the circulation line 20 from affecting the normal oil circuit operation, and at the same time, the oil can flow to various positions of the main oil pressure line 2 and the main oil return line 3 during low temperature / high temperature circulation.

[0046] like Figure 2 and Figure 3 As shown, as an embodiment, the main reversing valve 42 is a proportional reversing valve (i.e., the main reversing valve 42 can change the hydraulic flow through the main reversing valve 42 by changing its opening), and the control unit 7 is also connected to the main reversing valve 42 and the oil supply pump unit 10 by signal. The control unit 7 is also used to control the opening of the main reversing valve 42 and the oil supply flow of the oil supply pump unit 10 according to the hydraulic oil demand flow of the boom action (i.e., the hydraulic oil demand flow calculated by the control unit 7 according to the boom action control instruction it receives), so that the oil supply flow meets the oil supply demand of the hydraulic cylinder 41.

[0047] like Figure 2 and Figure 3As shown, as an embodiment, the standby reversing valve 43 is a conventional quantitative reversing valve (i.e., the hydraulic flow passing through it cannot be changed) to save costs, and the control unit 7 is also connected to the standby reversing valve 43 signal to control the opening and closing and reversing action of the standby reversing valve 43. Of course, in other embodiments, the standby reversing valve 43 can also be a proportional reversing valve.

[0048] like Figure 2 and Figure 3 As shown, as an embodiment, the hydraulic control system of the concrete placing equipment further includes a pressure detection unit 6 and a relief valve 22. The pressure detection unit 6 is used to detect the operating load pressure of the hydraulic cylinder 41 and the outlet pressure of the oil supply pump unit 10. The inlet of the relief valve 22 is connected to the oil pressure main line 2 (specifically, the inlet of the relief valve 22 is connected to the oil pressure main line 2 after the oil supply pump unit 10), and the outlet of the relief valve 22 is connected to the oil return main line 3. The control unit 7 is also connected to the pressure detection unit 6 and the relief valve 22 signal, and the control unit 7 is also used to control the relief setting value of the relief valve 22 according to the pressure signal detected by the pressure detection unit 6 and the oil temperature information detected by the oil temperature detection unit 5.

[0049] Specifically, the outlet flow of the oil supply pump unit 10 generally needs to be greater than the oil supply demand flow of the hydraulic cylinder 41. By changing the overflow setting value of the overflow valve 22, the outlet flow of the oil supply pump unit 10 can be changed (that is, the hydraulic flow exceeding the overflow setting value of the overflow valve 22 will return to the hydraulic oil tank 1 through the overflow valve 22); that is, by adjusting the overflow setting value of the overflow valve 22, the outlet flow of the oil supply pump unit 10 can be fine-tuned so that the displacement of the oil supply pump unit 10 can meet the demand flow in real time (adjusting the opening of the main reversing valve 42 and the oil supply flow of the oil supply pump unit 10 generally regulates the initial flow of the system, which is suitable for coarse adjustment; adjusting the overflow setting value of the overflow valve 22 can fine-tune and fine-tune the flow).

[0050] At the same time, the prior art does not take into account the impact of oil temperature on the oil supply flow rate, and is unable to compensate for the flow deviation caused by the change in oil temperature (for example, when the oil temperature decreases, the kinematic viscosity of the oil increases, the pressure loss increases, and the actual oil supply flow rate decreases); this embodiment uses the oil temperature detection unit 5 to detect the oil temperature information, and uses the pressure detection unit 6 to detect the operating load pressure of the hydraulic cylinder 41 and the outlet pressure of the oil supply pump unit 10, and calculates the pressure difference between the two, so as to adjust the overflow setting value of the overflow valve 22, and then fine-tune the outlet flow of the oil supply pump unit 10, so that the displacement of the oil supply pump unit 10 can meet the required flow in real time.

[0051] like Figure 2 and Figure 3As shown, as an embodiment, the pressure detection unit 6 includes a first pressure sensor 61 and a second pressure sensor 62, and the control unit 7 is simultaneously connected to the first pressure sensor 61 and the second pressure sensor 62 by signal. The first pressure sensor 61 is connected to the inner cavity of the main reversing valve 42, and the first pressure sensor 61 is used to detect the operating load pressure of the hydraulic cylinder 41; at the same time, the inner cavity of the main reversing valve 42 is also connected to the hydraulic oil tank 1 through the pressure relief pipeline 40, so that when the main reversing valve 42 is not working, the hydraulic oil in the main reversing valve 42 can be unloaded to the hydraulic oil tank 1 through the pressure relief pipeline 40 (to avoid the hydraulic oil in the main reversing valve 42 always existing, so that the first pressure sensor 61 can always obtain the pressure signal and cause misjudgment). The second pressure sensor 62 is arranged on the main pressure oil pipeline 2 at the outlet of the oil supply pump unit 10, and the second pressure sensor 62 is used to detect the outlet pressure of the oil supply pump unit 10. Of course, in other embodiments, the first pressure sensor 61 and the second pressure sensor 62 can also be arranged in other forms and positions.

[0052] like Figure 2 As shown, as an implementation mode, a pressure reducing valve 48 is further provided between the oil inlet of the main reversing valve 42 and the oil pressure main line 2, and the pressure reducing valve 48 is used to control the oil supply pressure and oil supply flow of each hydraulic actuator unit 4, thereby realizing automatic flow distribution between each hydraulic actuator unit 4.

[0053] like Figure 2 As shown, as an embodiment, a third one-way valve 23 is further provided on the main oil pressure line 2, and a fourth one-way valve 33 is further provided on the main oil return line 3. A filter 32 is further provided on the main oil pressure line 2 and the main oil return line 3.

[0054] like Figure 2 and Figure 3 As shown, as an embodiment, the oil supply pump unit 10 includes a variable displacement pump 11 (i.e., a pump with variable displacement), the variable displacement pump 11 is arranged on the oil pressure main line 2, the control unit 7 is connected to the variable displacement pump 11 by signal, and the control unit 7 is used to control the displacement of the variable displacement pump 11, thereby controlling the oil supply flow rate. The variable displacement pump 11 can be specifically an electrically controlled variable displacement piston pump.

[0055] like Figure 4 and Figure 5As shown, as another embodiment, the oil supply pump unit 10 includes a metering pump 12 (i.e., a pump with a fixed displacement), a flow regulating valve 13 and a return line 14. The metering pump 12 is arranged on the main pressure oil line 2, one end of the return line 14 is connected to the outlet of the metering pump 12 (specifically, connected to the main pressure oil line 2 after the outlet of the metering pump 12), the other end of the return line 14 is connected to the hydraulic oil tank 1, and the flow regulating valve 13 is arranged on the return line 14; the control unit 7 is connected to the flow regulating valve 13 and the metering pump 12 by signal, and the control unit 7 is used to control the opening and closing of the metering pump 12 and the opening of the flow regulating valve 13, so as to control the return amount of oil (excess oil returns to the hydraulic oil tank 1 through the return line 14 and the flow regulating valve 13), and then control the oil supply flow (this method can be used for both coarse adjustment of the initial flow of the system and fine adjustment and fine tuning of the flow).

[0056] As an embodiment, the main reversing valve 42, the spare reversing valve 43 and the switch valve 21 are all electrically controlled reversing valves. The control unit 7 is simultaneously connected to the oil temperature detection unit 5, the switch valve 21, the radiator 31, the overflow valve 22, the pressure detection unit 6, the main reversing valve 42, the spare reversing valve 43 and the oil supply pump unit 10 by electrical signals.

[0057] The embodiment of the present invention further provides a control method applied to the hydraulic control system of the concrete placing equipment, the control method comprising:

[0058] When the oil temperature detection unit 5 detects that the hydraulic oil temperature in the oil pressure main line 2 is lower than the set value or the hydraulic oil temperature in the hydraulic oil tank 1, the control unit 7 controls the switch valve 21 to open and the radiator 31 to close, so that the hydraulic oil in the hydraulic oil tank 1 is circulated back to the hydraulic oil tank 1 through the oil pressure main line 2, the circulation line 20 and the return oil main line 3 in sequence (at this time, the main reversing valve 42 and the standby reversing valve 43 are in the closed state), thereby quickly circulating and exchanging the cold oil in the pipeline, and quickly circulating and transferring the hot oil in the hydraulic oil tank 1 to the pipeline;

[0059] When the oil temperature detection unit 5 detects that the temperature of the hydraulic oil in the hydraulic oil tank 1 is higher than the control value, the control unit 7 controls the switch valve 21 and the radiator 31 to open, so that the hydraulic oil in the hydraulic oil tank 1 circulates back to the hydraulic oil tank 1 through the oil pressure main line 2, the circulation line 20, the oil return main line 3 and the radiator 31 in sequence (at this time, the main reversing valve 42 and the spare reversing valve 43 are in the closed state), so that the hot oil circulates in the radiator 31 and the pipeline to dissipate heat.

[0060] The embodiment of the present invention also provides a concrete distribution equipment, including the above-mentioned concrete distribution equipment hydraulic control system, and the concrete distribution equipment can be a concrete pump truck, a concrete distribution machine, etc. The hydraulic oil tank 1 and the oil supply pump unit 10 are arranged on the chassis position of the concrete distribution equipment, and the hydraulic oil cylinder 41 and the control valve group in each hydraulic actuator unit 4 are arranged on the arm of the concrete distribution equipment. One end of the pressure oil main line 2 and the return oil main line 3 are connected to the hydraulic oil tank 1, and the other ends of the pressure oil main line 2 and the return oil main line 3 are laid along the arm; the number of hydraulic actuator units 4 is multiple, and the multiple hydraulic actuator units 4 are arranged in parallel in sequence, and the pressure oil main line 2 and the return oil main line 3 are respectively connected to the multiple hydraulic actuator units 4, so that only one pressure oil main line 2 and one return oil main line 3 are required to be arranged in the concrete distribution equipment.

[0061] As an implementation method, the workflow of the hydraulic control system of the concrete placing equipment includes:

[0062] 1. When the hydraulic system is working, the control unit 7 calculates the required flow rate of hydraulic oil according to the boom motion control command it receives, and controls the opening of the main reversing valve 42 and the oil supply flow rate of the oil supply pump unit 10 according to the calculated required flow rate of hydraulic oil. At the same time, the control unit 7 reads the pressure signal detected by the pressure detection unit 6 and the oil temperature information detected by the oil temperature detection unit 5, adjusts the overflow setting value of the overflow valve 22, and then fine-tunes the outlet flow rate of the oil supply pump unit 10, so that the displacement of the oil supply pump unit 10 can meet the required flow rate in real time.

[0063] 2. The control unit 7 monitors the hydraulic oil temperature in the oil pressure main line 2 and the hydraulic oil temperature in the hydraulic oil tank 1 in real time. When the oil temperature detection unit 5 detects that the hydraulic oil temperature in the oil pressure main line 2 is lower than the set value or the hydraulic oil temperature in the hydraulic oil tank 1, in the standby condition, the control unit 7 controls the switch valve 21 to open and the radiator 31 to close, so that the hydraulic oil in the hydraulic oil tank 1 circulates back to the hydraulic oil tank 1 through the oil pressure main line 2, the circulation line 20 and the return oil main line 3 in sequence. When the oil temperature detection unit 5 detects that the hydraulic oil temperature in the hydraulic oil tank 1 is higher than the control value, in the standby condition, the control unit 7 controls the switch valve 21 and the radiator 31 to open, so that the hydraulic oil in the hydraulic oil tank 1 circulates back to the hydraulic oil tank 1 through the oil pressure main line 2, the circulation line 20, the return oil main line 3 and the radiator 31 in sequence.

[0064] 3. When the main reversing valve 42 fails, the standby reversing valve 43 as an emergency operation valve can replace the main reversing valve 42 to control the operation of the hydraulic cylinder 41, thereby enabling emergency operation of the boom.

[0065] The advantages of the hydraulic control system for concrete placing equipment provided in this embodiment include:

[0066] 1. The control valve group of each hydraulic actuator unit 4 is arranged in a distributed manner, that is, the control valve group of each hydraulic actuator unit 4 is arranged close to the hydraulic cylinder 41 or integrated on the hydraulic cylinder 41 (instead of adopting a multi-way valve to integrate multiple reversing valves together), thereby shortening the distance between the control valve group and the hydraulic cylinder 41 and improving the response speed of the hydraulic cylinder 41.

[0067] 2. The control valve group of each hydraulic actuator unit 4 can be connected in parallel to the oil pressure main line 2 and the oil return main line 3, that is, the same main line is used to be connected in series to the hydraulic cylinders 41 on each arm, and there is no need to lay long oil pressure pipelines and oil return pipelines between each reversing valve and the corresponding cylinder, thereby saving the number of pipelines. At the same time, the oil pressure main line 2 and the oil return main line 3 can use large-diameter pipelines, thereby reducing system pressure loss and further improving the response speed of the hydraulic cylinder 41.

[0068] 3. The control valve group is provided with a main reversing valve 42 and a spare reversing valve 43. When the main reversing valve 42 fails, the spare reversing valve 43 can replace the main reversing valve 42 to control the operation of the hydraulic cylinder 41, thereby enabling emergency operation of the boom and improving the safety of the system.

[0069] 4. The oil temperature in the pipeline and the hydraulic oil tank 1 is regulated by cooperating with the control unit 7, the oil temperature detection unit 5, the radiator 31 and the switch valve 21 to avoid abnormal low or high temperature of the hydraulic oil.

[0070] 5. The prior art does not consider the influence of oil temperature on the oil supply flow rate, and is unable to compensate for the flow deviation caused by the change in oil temperature. The present embodiment utilizes the oil temperature detection unit 5 to detect the oil temperature information, and utilizes the pressure detection unit 6 to detect the operating load pressure of the hydraulic cylinder 41 and the outlet pressure of the oil supply pump unit 10, and calculates the pressure difference between the two, thereby adjusting the overflow setting value of the overflow valve 22, and then fine-tuning the outlet flow of the oil supply pump unit 10, so that the displacement of the oil supply pump unit 10 can meet the required flow in real time.

[0071] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A hydraulic control system for concrete placing equipment, It is characterized in that It includes a hydraulic oil tank, an oil supply pump unit, an oil pressure main line, an oil return main line and at least one hydraulic actuator unit; one end of the oil pressure main line is connected to the hydraulic oil tank, the oil supply pump unit is arranged on the oil pressure main line; one end of the oil return main line is connected to the hydraulic oil tank; Each of the hydraulic actuator units includes a hydraulic cylinder and a control valve group, wherein the control valve group is arranged close to the hydraulic cylinder, or the control valve group is integrated on the hydraulic cylinder; the control valve group includes a main reversing valve, a spare reversing valve and a balancing valve group, the oil inlet of the main reversing valve and the oil inlet of the spare reversing valve are respectively connected to the main oil pressure line, the oil return port of the main reversing valve and the oil return port of the spare reversing valve are respectively connected to the main oil return line, and the oil outlet of the main reversing valve and the oil outlet of the spare reversing valve are respectively connected to the hydraulic cylinder through the balancing valve group.

2. The hydraulic control system for concrete placing equipment according to claim 1, It is characterized in that The balancing valve group includes a first balancing valve, a second balancing valve, a first non-return valve and a second non-return valve. The first balancing valve is arranged in reverse parallel with the first non-return valve, and the second balancing valve is arranged in reverse parallel with the second non-return valve. The first oil outlet of the main reversing valve and the first oil outlet of the standby reversing valve are both connected to the outlet of the first balancing valve and the inlet of the first non-return valve at the same time, and the inlet of the first balancing valve and the outlet of the first non-return valve are both connected to an oil port of the hydraulic cylinder. The second oil outlet of the main reversing valve and the second oil outlet of the standby reversing valve are both connected to the outlet of the second balancing valve and the inlet of the second non-return valve at the same time, and the inlet of the second balancing valve and the outlet of the second non-return valve are both connected to another oil port of the hydraulic cylinder.

3. The hydraulic control system for concrete placing equipment according to claim 2, It is characterized in that The first balancing valve and the second balancing valve are both pilot-operated balancing valves; the control oil port of the first balancing valve is connected to the second oil outlet of the main reversing valve and the second oil outlet of the standby reversing valve, and the control oil port of the second balancing valve is connected to the first oil outlet of the main reversing valve and the first oil outlet of the standby reversing valve.

4. The hydraulic control system for concrete placing equipment according to any one of claims 1 to 3, It is characterized in that The concrete placing equipment hydraulic control system further comprises an oil temperature detection unit and a control unit, wherein the oil temperature detection unit is used to detect the temperature of the hydraulic oil in the hydraulic oil tank and the temperature of the hydraulic oil in the oil pressure main line; a radiator for cooling the hydraulic oil is provided on the oil return main line; The oil pressure main line and the oil return main line are connected via a circulation line, and a switch valve is provided on the circulation line; the control unit is simultaneously connected to the oil temperature detection unit, the switch valve and the radiator signal, and the control unit is used to control the opening and closing of the switch valve and the radiator according to the oil temperature information detected by the oil temperature detection unit.

5. The hydraulic control system for concrete placing equipment according to claim 4, It is characterized in that The oil temperature detection unit includes a main line temperature sensor and an oil tank temperature sensor. The oil tank temperature sensor is connected to the hydraulic oil tank, and the oil tank temperature sensor is used to detect the temperature of the hydraulic oil in the hydraulic oil tank; the main line temperature sensor is arranged on the oil pressure main line or the circulation line, and the main line temperature sensor is used to detect the temperature of the hydraulic oil in the oil pressure main line.

6. The hydraulic control system for concrete placing equipment according to claim 5, It is characterized in that The main line temperature sensor is arranged at the end of the oil pressure main line away from the hydraulic oil tank; or, the circulation line is connected to the ends of the oil pressure main line and the oil return main line away from the hydraulic oil tank, and the main line temperature sensor is arranged on the circulation line.

7. The hydraulic control system for concrete placing equipment according to claim 4, It is characterized in that There are multiple hydraulic actuator units, and the multiple hydraulic actuator units are arranged in parallel in sequence; the oil pressure main line and the oil return main line are respectively connected to the multiple hydraulic actuator units, and the end of the oil pressure main line and the end of the oil return main line are connected to the hydraulic actuator unit at the tail end, and the circulation pipeline is connected to the end of the oil pressure main line and the end of the oil return main line.

8. The hydraulic control system for concrete placing equipment according to claim 4, It is characterized in that The concrete placing equipment hydraulic control system also includes a pressure detection unit and a relief valve. The pressure detection unit is used to detect the operating load pressure of the hydraulic cylinder and the outlet pressure of the oil supply pump unit; the inlet of the relief valve is connected to the oil pressure main line, and the outlet of the relief valve is connected to the oil return main line; the control unit is also connected to the pressure detection unit and the relief valve signal, and the control unit is also used to control the relief setting value of the relief valve according to the pressure signal detected by the pressure detection unit and the oil temperature information detected by the oil temperature detection unit.

9. The hydraulic control system for concrete placing equipment according to claim 4, It is characterized in that The main reversing valve is a proportional reversing valve, and the control unit is also connected to the main reversing valve and the oil supply pump unit by signal; the control unit is also used to control the opening of the main reversing valve and the oil supply flow of the oil supply pump unit according to the hydraulic oil demand flow of the boom movement.

10. A control method for a hydraulic control system of a concrete placing equipment according to any one of claims 4 to 9, It is characterized in that The control method comprises: When the oil temperature detection unit detects that the hydraulic oil temperature in the oil pressure main line is lower than the set value or the hydraulic oil temperature in the hydraulic oil tank, the control unit controls the switch valve to open and the radiator to close, so that the hydraulic oil in the hydraulic oil tank is circulated back to the hydraulic oil tank through the oil pressure main line, the circulation line and the oil return main line in sequence; When the oil temperature detection unit detects that the temperature of the hydraulic oil in the hydraulic oil tank is higher than the control value, the control unit controls the switch valve and the radiator to open, so that the hydraulic oil in the hydraulic oil tank circulates back to the hydraulic oil tank through the oil pressure main line, the circulation line, the oil return main line and the radiator in sequence.

11. A concrete placing device, It is characterized in that It comprises a hydraulic control system for concrete placing equipment according to any one of claims 1 to 9, wherein the hydraulic cylinder and the control valve group in each hydraulic actuator unit are arranged on the arm of the concrete placing equipment; there are multiple hydraulic actuator units, and the multiple hydraulic actuator units are arranged in parallel in sequence, and the oil pressure main line and the oil return main line are respectively connected to the multiple hydraulic actuator units.

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