Power apparatus suitable for multiple types of hydraulic systems, engineering machinery and test device

Abstract

The present application discloses a power apparatus suitable for multiple types of hydraulic systems, engineering machinery, and a test device. The power apparatus suitable for multiple types of hydraulic systems comprises: a working pump (1); a load sensing valve (11) and an electro-proportional displacement regulating valve (14), which are arranged in a displacement regulating control oil passage of the working pump (1) and are used for regulating the displacement of the working pump (1); and a mode switching valve (15), which is arranged in a load feedback oil passage LS of the working pump (1) and is used for switching the working pump to work in a load sensing control mode or an electro-proportional control mode. The present application can meet requirements of various working scenarios for hydraulic systems and reduce operation costs of production enterprises and users.

Description

Power units, construction machinery and testing equipment adaptable to various types of hydraulic systems Technical Field

[0001] This invention belongs to the field of engineering machinery technology, specifically relating to a power unit, engineering machinery and testing equipment adapted to multiple types of hydraulic systems. Background Technology

[0002] As operational machinery, cranes are essentially profit-generating tools for users, and operating costs have a decisive impact on profitability. Operating costs mainly consist of fuel costs and maintenance costs. Traditional cranes mostly use diesel engines as their power source, which are limited by the efficiency of traditional fuel engines, resulting in low fuel utilization. However, typical crane operating conditions (often involving long-term construction at fixed locations) make it possible for cranes to utilize on-site power supplies. Existing plug-in products are mostly developed based on specific models, with the electric power system integrated into the entire machine, making it impossible to achieve the application of a single power unit driving multiple crane models.

[0003] Existing power units or power stations are matched according to the type of hydraulic system. Taking the commonly used hydraulic systems of cranes as an example, they are mainly divided into three types: fixed displacement pump throttling speed control system, load-sensitive pump hydraulic control throttling speed control system, and electro-proportional pump + electro-proportional valve pump control system. Many customers have cranes of different tonnages, requiring different power units to be matched according to the type of hydraulic system, which greatly increases the customer's operating costs. Similarly, when crane manufacturers conduct performance testing for onboard operations, they modify the chassis oil supply system to achieve multi-purpose functionality for a common chassis when debugging different models of superstructure products. However, this modification is difficult, time-consuming, and repeated modifications bring risks to system reliability. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a power unit, engineering machinery, and testing equipment that is compatible with various types of hydraulic systems, meeting the needs of hydraulic systems in various operating scenarios and reducing operating costs for manufacturers and users.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] In a first aspect, a power unit adaptable to multiple types of hydraulic systems is provided, comprising: a working pump; a load-sensitive valve and an electro-proportional displacement regulating valve disposed in the displacement regulating control oil circuit of the working pump for regulating the displacement of the working pump; and a mode switching valve disposed in the load feedback oil circuit LS of the working pump for switching the working pump to operate in load-sensitive control mode or electro-proportional control mode.

[0007] Furthermore, it also includes: a pressure shut-off valve installed in the outlet circuit of the working pump for setting the maximum system pressure; and a power limiting valve installed in the outlet circuit of the working pump for setting the maximum system power.

[0008] Furthermore, the inlet of the mode switching valve is connected to the outlet of the working pump; the outlet of the mode switching valve is connected to the control terminal of the load-sensitive valve; the control terminal of the load-sensitive valve is connected to the load feedback oil circuit LS; the outlet of the mode switching valve is connected to the inlet of the electro-proportional displacement regulating valve; the outlet of the electro-proportional displacement regulating valve is connected to the inlet of the power limiting valve; the outlet of the power limiting valve is connected to the inlet of the pressure shut-off valve; the outlet of the pressure shut-off valve is connected to the inlet of the load-sensitive valve; the outlet of the load-sensitive valve is connected to one of the control terminals of the working pump; the inlet of the load-sensitive valve, the inlet of the pressure shut-off valve, and the inlet of the power limiting valve are respectively connected to the outlet of the working pump.

[0009] Furthermore, when matching a load-sensitive pump system model, the mode switching valve should not be energized, the electric proportional displacement regulating valve should not be energized, and the load feedback oil circuit LS acts on the control terminal of the load-sensitive valve. The working pump is then used as a load-sensitive pump. By adjusting the setting value of the power limiting valve, the power requirements of different motors and the usage restrictions of the power distribution cabinet under plug-in operation conditions can be matched.

[0010] Furthermore, when matching the electronically controlled pump system model, the mode switching valve is in the energized state. At this time, the outlet pressure of the working pump enters the electro-proportional displacement regulating valve through the mode switching valve. Since there is no load feedback oil circuit LS, the load sensing function of the load sensing valve is ineffective. At this time, the control terminal of the electro-proportional displacement regulating valve receives the PWM signal, and the variable pump realizes the composite control of electro-proportional displacement, pressure cut-off and constant power.

[0011] Furthermore, it also includes an auxiliary pump that provides pilot pressure to the electronically controlled pump system via a parallel pressure reducing valve.

[0012] Furthermore, the inlet of the mode switching valve is connected to the outlet of the working pump, the inlet of the mode switching valve is connected to the load feedback oil circuit LS, and the outlet of the mode switching valve is connected to the control terminal 2 of the load sensitive valve. The control terminal 1 of the load sensitive valve, the inlet 1 of the load sensitive valve, the control terminal 1 of the pressure shut-off valve, the inlet 1 of the pressure shut-off valve, the inlet 1 of the power limiting valve, and the inlet of the electro-proportional displacement regulating valve are respectively connected to the outlet of the working pump. The outlet of the electro-proportional displacement regulating valve is connected to the inlet 2 of the power limiting valve, the outlet of the power limiting valve is connected to the inlet 2 of the pressure shut-off valve, and the outlet of the pressure shut-off valve is connected to the inlet 2 of the load sensitive valve. The outlet of the load sensitive valve is connected to one of the control terminals of the working pump. When the mode switching valve is not energized, the load feedback oil circuit LS enters the control terminal 2 of the load sensitive valve through the mode switching valve, and the outlet oil circuit of the working pump enters the control terminal 1 of the load sensitive valve. At this time, the working pump is used as a load sensitive pump. When the mode switching valve is energized, the outlet pressure of the working pump is introduced into both sides of the load sensitive valve. At this time, under the action of the spring force, the load sensitive valve is always in the right position, and the load sensing effect is shielded. At this time, the working pump is used as an electro-proportional pump.

[0013] Furthermore, the inlet of the mode switching valve is connected to the outlet of the working pump; the control terminal one of the mode switching valve is connected to the load feedback oil circuit LS; the outlet one of the mode switching valve is connected to the control terminal one of the load sensitive valve; the outlet two of the mode switching valve is connected to the inlet of the electro-proportional displacement regulating valve; the outlet of the electro-proportional displacement regulating valve is connected to the inlet two of the power limiting valve; the outlet of the power limiting valve is connected to the inlet two of the pressure shut-off valve; the outlet of the pressure shut-off valve is connected to the inlet two of the load sensitive valve; the outlet of the load sensitive valve is connected to one of the control terminals of the working pump; the control terminal two of the load sensitive valve is connected to the load feedback oil circuit LS; the inlet one of the load sensitive valve, the control terminal of the pressure shut-off valve, the inlet one of the pressure shut-off valve, and the inlet one of the power limiting valve are respectively connected to the outlet of the working pump; when matched with the load sensitive pump hydraulic system, the load feedback oil circuit LS is also used for the switching of the load sensitive valve and the mode switching valve, and the spring pressure of the mode switching valve is less than the pressure of the load feedback oil circuit LS.

[0014] In a second aspect, a type of construction machinery is provided, which is equipped with the power unit adapted to the multi-type hydraulic system described in the first aspect.

[0015] Thirdly, an engineering machinery testing device is provided, wherein the engineering machinery testing device is equipped with the power unit adapted to multiple types of hydraulic systems as described in the first aspect.

[0016] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: By setting a load-sensitive valve and an electro-proportional displacement regulating valve in the displacement regulation control oil circuit of the working pump to regulate the displacement of the working pump; and setting a mode switching valve in the load feedback oil circuit LS of the working pump to switch the working pump to work in load-sensitive control mode or electro-proportional control mode, the present invention can be compatible with the hydraulic system requirements of various operating scenarios and reduce the operating costs of production enterprises and users. Attached Figure Description

[0017] Figure 1 is a schematic diagram of the principle of a power device adapted to multiple types of hydraulic systems provided in Embodiment 1 of the present invention;

[0018] Figure 2 is a schematic diagram of the working principle when the electronically controlled pump system model in Figure 1 is matched;

[0019] Figure 3 is a schematic diagram of the principle of a power device adapted to multiple types of hydraulic systems provided in Embodiment 2 of the present invention;

[0020] Figure 4 is a schematic diagram of the principle of a power device adapted to multiple types of hydraulic systems provided in Embodiment 3 of the present invention;

[0021] In the diagram: 1. Working pump; 2. Rotary pump; 3. Auxiliary pump; 4. Pressure reducing valve; 10. Power unit adaptable to various types of hydraulic systems; 11. Load-sensitive valve; 12. Pressure shut-off valve; 13. Power limiting valve; 14. Electro-proportional displacement regulating valve; 15. Mode switching valve; 20. Main hydraulic system pump set; 30. Center rotary joint. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0023] Example 1

[0024] A power unit adaptable to multiple types of hydraulic systems includes: a working pump 1; a load-sensitive valve 11 and an electro-proportional displacement regulating valve 14 disposed in the displacement regulating control oil circuit of the working pump 1 for regulating the displacement of the working pump 1; a mode switching valve 15 disposed in the load feedback oil circuit LS of the working pump 1 for switching the working pump 1 to work in load-sensitive control mode or electro-proportional control mode; a pressure shut-off valve 12 disposed in the outlet circuit of the working pump for setting the maximum system pressure; and a power limiting valve 13 disposed in the outlet circuit of the working pump for setting the maximum system power.

[0025] As shown in Figure 1, in the power unit 10 adapted to multiple types of hydraulic systems, the working pump 1 is a piston pump, and its outlet is connected to port P1 in the central rotary joint 30. The outlet of the rotary pump 2 is connected to port P2 in the central rotary joint 30. The outlet of the auxiliary pump 3 is connected to port P3 in the central rotary joint 30. Ports P1, P2, and P3, the load feedback oil circuit LS, and the return port T in the central rotary joint 30 are respectively connected to the main hydraulic system pump group 20.

[0026] The inlet of mode switching valve 15 is connected to the outlet of working pump 1. The outlet of mode switching valve 15 is connected to the control terminal 1 of load sensitive valve 11. The control terminal 2 of load sensitive valve 11 is connected to the load feedback oil circuit LS. The outlet 2 of mode switching valve 15 is connected to the inlet of electro-proportional displacement regulating valve 14. The outlet of electro-proportional displacement regulating valve 14 is connected to the inlet 2 of power limiting valve 13. The outlet of power limiting valve 13 is connected to the inlet 2 of pressure shut-off valve 12. The outlet of pressure shut-off valve 12 is connected to the inlet 2 of load sensitive valve 11. The outlet of load sensitive valve 11 is connected to one of the control terminals of working pump 1. The inlet 1 of load sensitive valve 11, the inlet 1 of pressure shut-off valve 12, and the inlet 1 of power limiting valve 13 are respectively connected to the outlet of working pump 1.

[0027] When matching a load-sensitive pump system, control terminal one (Y01) of mode switching valve 15 is de-energized, control terminal one (Y02) of electro-proportional displacement regulating valve 14 is de-energized, and the load feedback oil circuit LS acts on the right side (control terminal two) of load-sensitive valve 11. Working pump 1 is then used as a load-sensitive pump. By adjusting the setting value of power limiting valve 13, different motor power requirements and the limitations of the distribution cabinet for plug-in operation conditions can be matched to avoid engine stalling during onboard operation. The priority of the three controls is pressure control, constant power control, and flow control.

[0028] When the electronically controlled pump system is matched, the mode switching valve 15 is energized, as shown in Figure 2. At this time, the outlet pressure of the working pump 1 enters the electro-proportional displacement regulating valve 14 through the mode switching valve 15. Since the system has no load feedback oil circuit LS, the load-sensitive valve 11 is always in the right position, and the load-sensitive function of the load-sensitive valve 11 is ineffective. At this time, the control terminal (Y02) of the electro-proportional displacement regulating valve 14 receives the PWM signal, and the variable pump realizes the composite control of electro-proportional displacement, pressure cut-off and constant power. Meanwhile, the auxiliary pump 3 provides pilot pressure to the electronically controlled pump system through the parallel pressure reducing valve 4.

[0029] This invention achieves the switching between load-sensitive pump control and electro-proportional pump control through the control mode switching valve 15, and achieves matching of different power unit devices / different tonnage vehicle models by adjusting the power limiting valve 13. The auxiliary pump 3 provides pilot pressure for the initial displacement of the electro-proportional pump control mode through the parallel pressure reducing valve 4, thereby realizing that the hydraulic system of the power unit is not compatible with the hydraulic system requirements of various working scenarios.

[0030] This invention overcomes the limitations of existing variable displacement pump systems, which can only achieve load-sensitive displacement adjustment / electro-proportional valve-controlled displacement adjustment, greatly improving the system's adaptability. Based on the characteristics of different hydraulic systems, motor power, and power distribution cabinet limitations, the switch between load-sensitive pump control and electro-proportional pump control modes is achieved by controlling the threshold values ​​of the mode switching valve 15 and the power limiting valve 13. The control strategy is simple, the system has high integration, and it enables multiple uses for a single pump. By purchasing a power unit compatible with multiple types of hydraulic systems, customers can match cranes of different hydraulic system types (covering cranes with lifting capacities from 25t to 300t), significantly reducing their operating costs.

[0031] This invention can also be used on test benches / pump stations / tooling test vehicles. By switching modes, it enables performance testing of different types of main valves, reduces the number of pump station / tooling commissioning vehicles, and thus reduces the operating costs of production enterprises.

[0032] Example 2

[0033] As shown in Figure 3, the inlet of mode switching valve 15 is connected to the outlet of working pump 1, the inlet of mode switching valve 15 is connected to the load feedback oil circuit LS, and the outlet of mode switching valve 15 is connected to the control terminal 2 of load sensitive valve 11. The control terminal 1 of load sensitive valve 11, the inlet 1 of load sensitive valve 11, the control terminal 1 of pressure shut-off valve 12, the inlet 1 of pressure shut-off valve 12, the inlet 1 of power limiting valve 13, and the inlet of electro-proportional displacement regulating valve 14 are respectively connected to the outlet of working pump 1. The outlet of electro-proportional displacement regulating valve 14 is connected to the inlet 2 of power limiting valve 13, the outlet of power limiting valve 13 is connected to the inlet 2 of pressure shut-off valve 12, and the outlet of pressure shut-off valve 12 is connected to the inlet 2 of load sensitive valve 11. The outlet of load sensitive valve 11 is connected to one of the control terminals of working pump 1.

[0034] Based on Embodiment 1, this embodiment changes the functional position of the mode switching valve 15. When the mode switching valve 15 is not energized, the load feedback oil circuit LS enters the right side (control terminal two) of the load sensitive valve 11 through the mode switching valve 15, and the outlet oil circuit of the working pump 1 enters the left side (control terminal one) of the load sensitive valve 11. At this time, the working pump 1 is used as a load sensitive pump. When the mode switching valve 15 is energized, the outlet pressure (P port pressure) of the working pump 1 is introduced into both sides of the load sensitive valve 11. At this time, under the action of the spring force, the load sensitive valve 11 is always in the right position, and the load sensing effect is shielded. At this time, the working pump 1 is used as an electric proportional pump.

[0035] Example 3

[0036] As shown in Figure 4, the inlet of the mode switching valve 15 is connected to the outlet of the working pump 1; the control terminal one of the mode switching valve 15 is connected to the load feedback oil circuit LS; the outlet one of the mode switching valve 15 is connected to the control terminal one of the load sensitive valve 11; the outlet two of the mode switching valve 15 is connected to the inlet of the electro-proportional displacement regulating valve 14; the outlet of the electro-proportional displacement regulating valve 14 is connected to the inlet two of the power limiting valve 13; the outlet of the power limiting valve 13 is connected to the inlet two of the pressure shut-off valve 12; the outlet of the pressure shut-off valve 12 is connected to the inlet two of the load sensitive valve 11; the outlet of the load sensitive valve 11 is connected to one of the control terminals of the working pump 1; the control terminal two of the load sensitive valve 11 is connected to the load feedback oil circuit LS; the inlet one of the load sensitive valve 11, the control terminal of the pressure shut-off valve 12, the inlet one of the pressure shut-off valve 12, and the inlet one of the power limiting valve 13 are respectively connected to the outlet of the working pump 1.

[0037] When matched with a load-sensitive pump hydraulic system, the load feedback oil circuit LS serves a dual purpose, replacing the solenoid switching valve and performing a reversing function, as shown in Figure 4. The load feedback oil circuit LS is used for reversing the load-sensitive valve 11 and the mode switching valve 15. This embodiment reduces costs, and to ensure the normal operation of the matched load feedback pump system, the spring pressure of the mode switching valve 15 must be less than the pressure of the load feedback oil circuit LS.

[0038] This invention only uses the variable mechanism of the A11V series pump as an example to illustrate mode switching, but its function is not limited to the A11V series piston pump, nor is it limited to power unit devices, but also includes hydraulic test benches, test fixtures, etc.

[0039] Example 4

[0040] Based on Embodiments 1 to 3, this embodiment provides an engineering machinery, which is equipped with a power unit adapted to multiple types of hydraulic systems as described in any one of Embodiments 1 to 3.

[0041] Example 5

[0042] Based on Embodiments 1 to 3, this embodiment provides an engineering machinery testing device, which is equipped with a power unit adapted to multiple types of hydraulic systems as described in any one of Embodiments 1 to 3.

[0043] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A power unit adaptable to multiple types of hydraulic systems, characterized in that, include: Working pump (1); A load-sensitive valve (11) and an electro-proportional displacement regulating valve (14) are installed in the displacement regulating control oil circuit of the working pump (1) to regulate the displacement of the working pump (1). A mode switching valve (15) is installed in the load feedback oil circuit LS of the working pump (1) to switch the working pump (1) to work in load-sensitive control mode or electro-proportional control mode.

2. The power unit adapted to multiple types of hydraulic systems according to claim 1, characterized in that, Also includes: A pressure shut-off valve (12) installed in the outlet circuit of the working pump to set the maximum pressure of the system; A power limiting valve (13) installed in the outlet circuit of the working pump to set the maximum power of the system.

3. The power unit adapted to multiple types of hydraulic systems according to claim 2, characterized in that, The inlet of the mode switching valve (15) is connected to the outlet of the working pump (1), the outlet of the mode switching valve (15) is connected to the control terminal of the load sensitive valve (11), the control terminal of the load sensitive valve (11) is connected to the load feedback oil circuit LS, the outlet of the mode switching valve (15) is connected to the inlet of the electric proportional displacement regulating valve (14); the outlet of the electric proportional displacement regulating valve (14) is connected to the inlet of the power limiting valve (13), the outlet of the power limiting valve (13) is connected to the inlet of the pressure shut-off valve (12), the outlet of the pressure shut-off valve (12) is connected to the inlet of the load sensitive valve (11); the outlet of the load sensitive valve (11) is connected to one of the control terminals of the working pump (1). The inlet of the load-sensitive valve (11), the inlet of the pressure shut-off valve (12), and the inlet of the power limiting valve (13) are respectively connected to the outlet of the working pump (1).

4. The power unit adapted to multiple types of hydraulic systems according to claim 3, characterized in that, When matching the load-sensitive pump system model, the mode switching valve (15) is not energized, the electric proportional displacement regulating valve (14) is not energized, the load feedback oil circuit LS acts on the control terminal of the load-sensitive valve (11), and the working pump (1) is used as a load-sensitive pump at this time; by adjusting the setting value of the power limiting valve (13), it can match the power requirements of different motors and the power distribution cabinet usage restrictions under the plug-in operation conditions.

5. The power unit adapted to multiple types of hydraulic systems according to claim 3, characterized in that, When the electric pump system model is matched, the mode switching valve (15) is energized. At this time, the outlet pressure of the working pump (1) enters the electric proportional displacement regulating valve (14) through the mode switching valve (15). Since there is no load feedback oil circuit LS, the load sensing function of the load sensing valve (11) fails. At this time, the control terminal of the electric proportional displacement regulating valve (14) receives the PWM signal, and the variable pump realizes the composite control of electric proportional displacement, pressure cut-off and constant power.

6. The power unit adapted to multiple types of hydraulic systems according to claim 5, characterized in that, It also includes an auxiliary pump (3), which provides pilot pressure to the electronically controlled pump system through a parallel pressure reducing valve (4).

7. The power unit adapted to multiple types of hydraulic systems according to claim 2, characterized in that, The inlet of the mode switching valve (15) is connected to the outlet of the working pump (1), the inlet of the mode switching valve (15) is connected to the load feedback oil circuit LS, and the outlet of the mode switching valve (15) is connected to the control terminal 2 of the load sensitive valve (11). The control terminal 1 of the load sensitive valve (11), the inlet 1 of the load sensitive valve (11), the control terminal 1 of the pressure shut-off valve (12), the inlet 1 of the pressure shut-off valve (12), the inlet 1 of the power limiting valve (13), and the inlet of the electro-proportional displacement regulating valve (14) are respectively connected to the outlet of the working pump (1). The outlet of the electro-proportional displacement regulating valve (14) is connected to the inlet 2 of the power limiting valve (13), the outlet of the power limiting valve (13) is connected to the inlet 2 of the pressure shut-off valve (12), and the outlet of the pressure shut-off valve (12) is connected to the inlet 2 of the load sensitive valve (11). The outlet of the load sensitive valve (11) is connected to one of the control terminals of the working pump (1). When the mode switching valve (15) is not energized, the load feedback oil circuit LS enters the control terminal 2 of the load sensitive valve (11) through the mode switching valve (15), and the outlet oil circuit of the working pump (1) enters the control terminal 1 of the load sensitive valve (11). At this time, the working pump (1) is used as a load sensitive pump. When the mode switching valve (15) is energized, the outlet pressure of the working pump (1) is introduced into both sides of the load-sensitive valve (11). At this time, under the action of the spring force, the load-sensitive valve (11) is always in the right position, and the load-sensitive function is shielded. At this time, the working pump (1) is used as an electric proportional pump.

8. The power unit adapted to multiple types of hydraulic systems according to claim 2, characterized in that, The inlet of the mode switching valve (15) is connected to the outlet of the working pump (1). The control terminal of the mode switching valve (15) is connected to the load feedback oil circuit LS. The outlet of the mode switching valve (15) is connected to the control terminal of the load sensitive valve (11). The outlet of the mode switching valve (15) is connected to the inlet of the electric proportional displacement regulating valve (14). The outlet of the electric proportional displacement regulating valve (14) is connected to the inlet of the power limiting valve (13). The outlet of the power limiting valve (13) is connected to the inlet of the pressure shut-off valve (12). The outlet of the pressure shut-off valve (12) is connected to the inlet of the load sensitive valve (11). The outlet of the load sensitive valve (11) is connected to one of the control terminals of the working pump (1). The control terminal of the load sensitive valve (11) is connected to the load feedback oil circuit LS. The inlet of the load sensitive valve (11), the control terminal of the pressure shut-off valve (12), the inlet of the pressure shut-off valve (12), and the inlet of the power limiting valve (13) are respectively connected to the outlet of the working pump (1). When matched with a load-sensitive pump hydraulic system, the load feedback circuit LS is also used for switching the load-sensitive valve (11) and the mode switching valve (15). The spring pressure of the mode switching valve (15) is less than the pressure of the load feedback circuit LS.

9. An engineering machinery, characterized in that, The engineering machinery is equipped with a power unit adapted to multiple types of hydraulic systems as described in any one of claims 1 to 8.

10. A testing device for engineering machinery, characterized in that, The engineering machinery testing equipment is equipped with a power unit adapted to multiple types of hydraulic systems as described in any one of claims 1 to 8.

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