Motor control device of hydrostatic system and hydrostatic system

Abstract

The utility model relates to a motor control device for a hydrostatic system and the hydrostatic system. The device comprises a power supply used for supplying power to the motor control device; the multi-gear switch comprises a power supply end, a movable contact and a plurality of static contacts which are selectively connected with the movable contact, the plurality of static contacts comprise a vacant end, a first wiring end, a second wiring end and a third wiring end, and the first relay comprises a power supply end, a first wiring end, a second wiring end and a grounding end; and the second relay comprises a power supply end, a first wiring end, a second wiring end and a grounding end. According to the circuit design of the motor control device, a vehicle control unit is omitted, control over a hydrostatic system is simplified, cost is reduced, and meanwhile the reliability and maintenance convenience of the system are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of a static hydraulic system, and more specifically, to a motor control device for a static hydraulic system, and a static hydraulic system. Background Art

[0002] In the static hydraulic system of conventional construction machinery, achieving multi-speed control is one of the key technologies to improve the operational flexibility and efficiency of construction machinery. Traditional static hydraulic systems are usually equipped with two hydraulic motors, which are used to control the rollers and the drive axle respectively to achieve different speed gears. Existing control schemes usually rely on the vehicle controller to achieve precise control of the hydraulic motor displacement and adjust the speed through the on-off combination of the solenoid valve.

[0003] However, this speed control method has some limitations. First, the integration of the vehicle controller increases the cost and complexity of the system. Second, excessive reliance on electronic control systems may increase the failure rate and affect the reliability of the vehicle. In addition, electronic control systems may require complex programming and debugging, which increases the difficulty of maintenance. Utility Model Content

[0004] In view of the above problems existing in the existing static hydraulic system control scheme, the utility model proposes a static hydraulic system control device with lower cost and simpler structure. The control device uses a rotary switch and two relays, combined with a new circuit design to directly control the two motor solenoid valves in the hydraulic system, thereby changing the displacement of the hydraulic motor and achieving the driving speed of the four gears of the engineering machinery.

[0005] A first aspect of the utility model provides a motor control device for a hydrostatic system, wherein the hydrostatic system comprises a first hydraulic motor and a second hydraulic motor, each of which is used to drive two different power elements in the hydrostatic system, and the operation states of the first and second hydraulic motors are controlled by a first solenoid valve and a second solenoid valve, respectively. The motor control device comprises:

[0006] a power supply, the power supply being used to supply power to the motor control device;

[0007] A multi-position switch, comprising a power supply terminal, a moving contact, and a plurality of stationary contacts selectively connected to the moving contact, wherein the plurality of stationary contacts comprise an idle terminal, a first wiring terminal, a second wiring terminal, and a third wiring terminal.

[0008] A first relay, the first relay comprising a power supply terminal, a first wiring terminal, a second wiring terminal and a ground terminal; and

[0009] a second relay, the second relay comprising a power supply terminal, a first wiring terminal, a second wiring terminal and a ground terminal,

[0010] Among them, the power supply ends of the multi-speed switch, the first relay and the second relay are connected to the positive pole of the power supply, the first terminal of the multi-speed switch is connected to the first end of the first solenoid valve and the first terminal of the first relay, the second terminal of the multi-speed switch is connected to the first end of the second solenoid valve and the first terminal of the second relay, the third terminal of the multi-speed switch is connected to the second terminal of the first relay and the second relay, and the ground terminal of the first relay, the ground terminal of the second relay, the second end of the first solenoid valve and the second end of the second solenoid valve are connected to the negative pole of the power supply.

[0011] According to an optional embodiment, when the idle end of the multi-position switch is connected to the moving contact, the first solenoid valve and the second solenoid valve are both closed.

[0012] According to an optional embodiment, when the first terminal of the multi-position switch is connected to the moving contact, the first solenoid valve is opened and the second solenoid valve is closed.

[0013] According to an optional embodiment, when the second terminal of the multi-position switch is connected to the moving contact, the first solenoid valve is closed and the second solenoid valve is opened.

[0014] According to an optional embodiment, when the third terminal of the multi-position switch is connected to the moving contact, both the first solenoid valve and the second solenoid valve are opened.

[0015] According to an optional embodiment, the motor control device further includes a controller configured to selectively connect the electrical connection between the moving contact of the multi-speed switch and a corresponding one of the plurality of stationary contacts to adjust the output power of the hydrostatic system.

[0016] According to an optional embodiment, the motor control device further includes a key switch for controlling the on and off of the power supply.

[0017] The second aspect of the utility model also provides a hydrostatic system, which includes a first hydraulic motor and a second hydraulic motor, which are respectively used to drive two different power elements in the hydrostatic system, and the operating states of the first and second hydraulic motors are respectively controlled by a first solenoid valve and a second solenoid valve, wherein the hydrostatic system also includes the motor control device as described above.

[0018] The main advantage of the motor control device used in the hydrostatic system of the utility model lies in its simplified circuit design. It directly controls the relay through a rotary switch, thereby accurately controlling the opening and closing state of the solenoid valve of the hydraulic motor. This direct control method not only reduces the dependence on the vehicle controller, but also reduces the overall complexity and cost of the system. At the same time, since the number of electronic components is reduced, the reliability of the system is improved, and maintenance and troubleshooting become easier. Through this wiring layout, the motor control device can achieve accurate combined control of the displacement of the two hydraulic motors, thereby providing four gears of driving speed, meeting the speed change requirements of engineering machinery under different driving conditions. This multi-gear control not only improves the maneuverability of engineering machinery, but also provides the driver with a smoother and more flexible driving experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] By incorporating the accompanying drawings and Figure 1 With reference to the specific implementation modes used to illustrate certain principles of the present invention, other features and advantages of the method of the present invention will become clear or be described in more detail.

[0020] Figure 1 A circuit layout diagram of a motor control device for a hydrostatic system according to an exemplary embodiment of the present invention is shown. DETAILED DESCRIPTION

[0021] The motor control device for a hydrostatic system according to the utility model will be described below with reference to the accompanying drawings and by way of example. In the following description, many specific details are set forth so that those skilled in the art can more fully understand the utility model. However, it is obvious to those skilled in the art that the utility model may be implemented without some of these specific details. Instead, it is contemplated that the utility model may be implemented with any combination of the following features and elements, regardless of whether they relate to different embodiments. Therefore, the following aspects, features, embodiments and advantages are for illustrative purposes only and should not be regarded as elements or limitations of the claims.

[0022] In the static hydraulic system of traditional construction machinery, it is necessary to use the vehicle controller to control the two hydraulic motors to adjust the speed of multiple gears of the construction machinery. This control method increases the cost and complexity of the system.

[0023] In order to improve the control flexibility and cost-effectiveness of a hydrostatic system, the utility model proposes a new motor control device for a hydrostatic system, which realizes precise control of two hydraulic motors in a hydraulic system through an innovative circuit design. The control device is particularly suitable for hydrostatic system engineering machinery requiring multi-gear speed control.

[0024] Figure 1 A circuit layout diagram of a motor control device for a hydrostatic system according to an exemplary embodiment of the present invention is shown.

[0025] like Figure 1 As shown in , the hydrostatic system usually includes two hydraulic motors M1 and M2 (one motor controls the rollers and the other controls the drive axle). By controlling the on-off combination of the solenoid valves on the two motors with the help of two solenoid valves EV1 and EV2, the start, stop, speed change and direction conversion of the two hydraulic motors can be effectively controlled, thereby controlling the displacement of the hydraulic motors and the output power of the hydrostatic system, thereby achieving four different driving speed gears of the construction machinery. This control scheme was originally implemented through a vehicle controller. The new control architecture proposed in the utility model uses a rotary switch and two relays to directly control the two solenoid valves, omitting the vehicle controller, thereby achieving the purpose of cost saving. The following is combined with Figure 1 The circuit layout of the motor control device is introduced in detail.

[0026] First, the motor control device includes a power supply VDD, which provides a stable power supply voltage for the entire control system. The power supply VDD is connected to the power supply terminals of the multi-shift switch S1, the first relay SW1 and the second relay SW2 to ensure that these switch elements can work normally.

[0027] The multi-position switch S1 is a key component of the control device, which includes a power supply terminal, a moving contact and multiple static contacts. The static contacts include an idle terminal, a first terminal, a second terminal and a third terminal. The multi-position switch S1 can be, for example, a knob switch, which allows the user to form an electrical path between the moving contact and different static contacts by rotating the switch button.

[0028] The device also includes two relays SW1 and SW2, wherein the first relay SW1 and the second relay SW2 are connected to the corresponding static contacts of the multi-position switch S1 through their first terminal and second terminal, respectively. Such a design allows the relay to control the power-on state of the solenoid valve according to the selection of the multi-position switch.

[0029] Specifically, the power supply terminals of the multi-position switch S1, the first relay SW1, and the second relay SW2 are all connected to the positive electrode of the power supply VDD. The first terminal of the multi-position switch is connected to the first end of the first electromagnetic valve EV1 and the first terminal of the first relay SW1, and the second terminal is connected to the first end of the second electromagnetic valve EV2 and the first terminal of the second relay SW2. The third terminal of the multi-position switch is connected to the second terminal of the first relay SW1 and the second relay SW2. The ground terminals of the first relay SW1 and the second relay SW2, the second end of the first electromagnetic valve EV1, and the second end of the second electromagnetic valve EV2 are all connected to the negative electrode of the power supply VDD.

[0030] The first solenoid valve EV1 and the second solenoid valve EV2 control the first hydraulic motor M1 and the second hydraulic motor M2 respectively. The second ends of these solenoid valves are connected to the negative pole of the power supply VDD through the ground terminal of the relay to ensure that the solenoid valves can work normally when the relay is activated.

[0031] In order to enhance the safety of the system, the motor control device may further include a key switch KS for controlling the on and off of the power supply VDD. This design ensures that the operator can confirm that all safety conditions have been met before the system is started.

[0032] The power supply VDD is connected to the circuit through the key switch KS and first reaches the power supply end of the multi-position switch S1. The multiple static contacts of the multi-position switch S1 are respectively connected to the first solenoid valve EV1, the second solenoid valve EV2 and the two relays SW1 and SW2. The ground terminal of the relay and the ground terminal of the solenoid valve are connected to the negative pole of the power supply VDD to form a closed loop.

[0033] Optionally, the device may further include a controller ( Figure 1 ), to replace the manual operation of the user, selectively connect the electrical connection between the moving contact of the multi-position switch S1 and a corresponding one of the plurality of stationary contacts, thereby adjusting the output power of the static hydraulic system.

[0034] The controller can be used to realize the following four different control modes of the motor control device:

[0035] - When the moving contact of the multi-shift switch is connected to the idle end, the first solenoid valve EV1 and the second solenoid valve EV2 are both closed, the first and second motors M1 and M2 do not work, the hydrostatic system is in a stopped state, and the construction machinery is in the lowest speed gear;

[0036] - When the moving contact is connected to the first terminal, only the first solenoid valve EV1 is opened and the second solenoid valve EV2 is closed, so that the first hydraulic motor M1 is independently controlled, that is, the first motor M1 works and the second motor M2 does not work, and the engineering machinery enters the second gear speed;

[0037] - When the moving contact is connected to the second terminal, only the second solenoid valve EV2 is opened and the first solenoid valve EV1 is closed, so that the second hydraulic motor M2 is independently controlled, that is, the first motor M1 does not work, the second motor M2 works, and the construction machine enters the third gear speed; and

[0038] -When the moving contact is connected to the third terminal, the current from the power supply VDD reaches the third terminal through the moving contact of the multi-speed switch, and the third terminal is connected to the second terminals of the two relays SW2 and SW2. The two relays work, and the current flows out from the relays SW2 and SW2 respectively and reaches the first solenoid valve EV1 and the second solenoid valve EV2. Both EV1 and EV2 are opened, thereby realizing the coordinated control of the two hydraulic motors. At this time, the static hydraulic system can provide the maximum output power, and the construction machinery reaches the highest speed gear.

[0039] Through the above control method, the motor control device can flexibly control the output power in the hydrostatic system, realize multi-gear speed control of engineering machinery, and simplify the system structure, reduce costs, and improve system reliability and ease of operation. This control method does not need to rely on a complex vehicle controller and is particularly suitable for hydrostatic systems of engineering machinery that require precise control of speed and power output.

[0040] An exemplary embodiment of the present utility model further proposes a hydrostatic system, the system comprising a first hydraulic motor M1 and a second hydraulic motor M2, respectively used to drive two different power elements (such as rollers and drive axles) in the hydrostatic system, the operation states of the first and second hydraulic motors are respectively controlled by solenoid valves EV1 and EV2, and the system further comprises the above reference Figure 1 The motor control device described.

[0041] The main advantage of the motor control device used in the hydrostatic system of the utility model lies in its simplified circuit design. It directly controls the relay through a rotary switch, thereby accurately controlling the opening and closing state of the solenoid valve of the hydraulic motor. This direct control method not only reduces the dependence on the vehicle controller, but also reduces the overall complexity and cost of the system. At the same time, since the number of electronic components is reduced, the reliability of the system is improved, and maintenance and troubleshooting become easier. Through this wiring layout, the motor control device can achieve accurate combined control of the displacement of the two hydraulic motors, thereby providing four gears of driving speed, meeting the speed change requirements of engineering machinery under different driving conditions. This multi-gear control not only improves the maneuverability of engineering machinery, but also provides the driver with a smoother and more flexible driving experience.

[0042] In the present invention, the term "connection" refers to "electrical connection" or "communication connection". In addition, the terms "include" and "comprising" indicate that in addition to the units directly and clearly stated in the specification and claims, the technical solution of the present application does not exclude the situation of having other units that are not directly or clearly stated.

[0043] In the present invention, it can be understood by those skilled in the art that the disclosed system can be implemented in other ways. The system implementation methods described above are merely illustrative. For example, the division of the modules is merely a logical function division. There may be other division methods in actual implementation, such as the functions of multiple modules can be combined or the functions of a module can be further split. The modules in each implementation method of the present invention can be integrated into a processing unit, or each module can exist physically separately, or two or more modules can be integrated into one unit.

[0044] Although the utility model has been disclosed as a preferred embodiment, the utility model is not limited thereto. Various changes and modifications made without departing from the spirit and scope of the utility model should be included in the protection scope of the utility model, so the protection scope of the utility model should be based on the scope defined by the claims.

Claims

1. A motor control device for a hydrostatic system, the hydrostatic system comprising a first hydraulic motor (M1) and a second hydraulic motor (M2), each used to drive two different power elements in the hydrostatic system, wherein the operating states of the first and second hydraulic motors are controlled by a first solenoid valve (EV1) and a second solenoid valve (EV2), respectively, wherein: The motor control device comprises: a power supply (VDD) for supplying power to the motor control device; A multi-position switch (S1), comprising a power supply terminal, a moving contact, and a plurality of stationary contacts selectively connected to the moving contact, wherein the plurality of stationary contacts comprise an idle terminal, a first wiring terminal, a second wiring terminal, and a third wiring terminal, a first relay (SW1), the first relay comprising a power supply terminal, a first wiring terminal, a second wiring terminal and a ground terminal; and a second relay (SW2), the second relay comprising a power supply terminal, a first connection terminal, a second connection terminal and a ground terminal, The power supply ends of the multi-position switch (S1), the first relay (SW1) and the second relay (SW2) are connected to the positive electrode of the power supply (VDD), the first terminal of the multi-position switch is connected to the first end of the first solenoid valve (EV1) and the first terminal of the first relay (SW1), the second terminal of the multi-position switch is connected to the first end of the second solenoid valve (EV2) and the first terminal of the second relay (SW2), the third terminal of the multi-position switch is connected to the second terminals of the first relay (SW1) and the second relay (SW2), the ground terminal of the first relay (SW1), the ground terminal of the second relay (SW2), the second end of the first solenoid valve (EV1) and the second end of the second solenoid valve (EV2) are connected to the negative electrode of the power supply (VDD).

2. The motor control device according to claim 1, characterized in that: When the idle end of the multi-position switch (S1) is connected to the moving contact, the first solenoid valve (EV1) and the second solenoid valve (EV2) are both closed.

3. The motor control device according to claim 1 or 2, characterized in that: When the first connection terminal of the multi-shift switch (S1) is connected to the moving contact, the first electromagnetic valve (EV1) is opened and the second electromagnetic valve (EV2) is closed.

4. The motor control device according to claim 1 or 2, characterized in that: When the second connection terminal of the multi-shift switch (S1) is connected to the moving contact, the first electromagnetic valve (EV1) is closed and the second electromagnetic valve (EV2) is opened.

5. The motor control device according to claim 1 or 2, characterized in that: When the third terminal of the multi-position switch (S1) is connected to the moving contact, both the first solenoid valve (EV1) and the second solenoid valve (EV2) are opened.

6. The motor control device according to claim 1 or 2, characterized in that: The motor control device further includes a controller configured to selectively connect the electrical connection between the moving contact of the multi-position switch (S1) and a corresponding one of the plurality of stationary contacts to adjust the output power of the static hydraulic system.

7. The motor control device according to claim 1 or 2, characterized in that: The motor control device further includes a key switch (KS) for controlling the on and off of the power supply (VDD).

8. A hydrostatic system, comprising a first hydraulic motor (M1) and a second hydraulic motor (M2), each used to drive two different power elements in the hydrostatic system, wherein the operation states of the first and second hydraulic motors are controlled by a first solenoid valve (EV1) and a second solenoid valve (EV2), respectively, and wherein: The hydrostatic system further comprises a motor control device according to any one of claims 1 to 7.

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