Electro-hydraulic control system, electro-hydraulic control method and engineering machinery

Abstract

The present invention relates to an electro-hydraulic control system for engineering machinery, which comprises: a hydraulic lock master switch; a hydraulic lock relay electrically connected to the hydraulic lock master switch; a hydraulic lock solenoid valve electrically connected to the hydraulic lock relay; and a controller electrically connected to a main pump and a main valve of the engineering machinery so as to control the action of the main pump and the main valve, wherein the controller is configured to: detect a closing signal of the hydraulic lock master switch; detect an opening signal of the hydraulic lock relay; wherein, when the controller does not detect a closing signal of the hydraulic lock master switch and detects an opening signal of the hydraulic lock relay, the controller sends an electrical signal to the main pump and the main valve so as to control the main pump and the main valve to be in a working state. The electro-hydraulic control system can avoid malfunction of an actuator caused by accidental contact or misoperation of an operating handle, etc., and eliminate potential safety hazards. The present invention also relates to an electro-hydraulic control method for engineering machinery and engineering machinery including the electro-hydraulic control system.

Description

Technical Field

[0001] The present invention relates to the field of electro-hydraulic control, in particular to an electro-hydraulic control system and an electro-hydraulic control method for engineering machinery, and also to an engineering machinery comprising the electro-hydraulic control system. Background Art

[0002] Engineering machinery such as excavators, loaders, bulldozers, etc. are usually equipped with an electro-hydraulic control system to provide hydraulic fluid (such as hydraulic oil) to hydraulic actuators such as rotary motors and cylinders according to the operator's operations, thereby completing the actions the operator wants to perform.

[0003] Figure 1 The following schematically shows an electro-hydraulic control system commonly used in engineering machinery in the prior art. Figure 3 The hydraulic lock control method in the electro-hydraulic control system of the prior art is schematically illustrated.

[0004] like Figure 3 As shown, the controller 4 is electrically connected to the opening / opening position of the hydraulic lock master switch 1 so as to detect the opening signal of the hydraulic lock master switch 1 when the hydraulic lock master switch 1 is opened. Figure 1 After the engine is started, the operator turns on the hydraulic lock master switch 1, the circuit is connected, and the electrical signal connects the hydraulic lock solenoid valve 3 through the hydraulic lock relay 2. At the same time, the controller 4 detects the opening signal of the hydraulic lock master switch 1. The pilot oil from the pilot oil circuit (pilot pump or pressure reducing valve) can reach the operating handle 6 through the hydraulic lock solenoid valve 3, thereby providing the pilot hydraulic fluid required for the operating action. The controller 4 sends an electrical signal to the main pump 13 of the engineering machinery and the main valve core control ports (electrical control) 7, 8 of the main valve 11, so that the main pump 13 and the main valve 11 are in working state. At this time, when the operating handle 6 is operated, the pilot oil is delivered to the main valve core control ports (hydraulic control) 9, 10 at both ends of the main valve 11, and the main valve 11 is opened to deliver the hydraulic oil from the main pump 13 to the hydraulic actuator 12, thereby completing the action that the operator wants to perform.

[0005] The above-mentioned electro-hydraulic control system has certain defects in safety.

[0006] On the one hand, when the hydraulic lock relay 2 is damaged, after the normally open hydraulic lock master switch 1 is turned on, the electrical signal cannot trigger the hydraulic lock solenoid valve 3. Since the controller 4 detects the opening signal of the hydraulic lock master switch 1, the controller 4 will determine that the machine is working normally. However, in fact, the whole vehicle does not move, so it cannot be reliably controlled.

[0007] On the other hand, when the hydraulic lock master switch 1 fails (at this time, the hydraulic lock master switch 1 is always in the closed position) and the hydraulic lock relay 2 functions normally, if the current reaches the hydraulic lock relay 2 through some path, the electrical signal will connect the hydraulic lock solenoid valve 3 through the relay 2. At this time, if the operating handle 6 is accidentally touched or misoperated, the main valve 11 will be reversed, and the actuators 12 (such as the swing motor, the oil cylinder, etc.) will malfunction, thereby causing safety hazards.

[0008] The present invention aims to solve the above-mentioned problems in the prior art. Summary of the invention

[0009] In view of the above-mentioned deficiencies in the prior art, the present invention proposes an electro-hydraulic control system and an electro-hydraulic control method for increasing the whole vehicle operation safety of engineering machinery.

[0010] According to one aspect of the present invention, there is provided an electro-hydraulic control system for an engineering machine, comprising:

[0011] Hydraulic lock master switch;

[0012] A hydraulic lock relay electrically connected to the hydraulic lock master switch;

[0013] A hydraulic lock solenoid valve electrically connected to the hydraulic lock relay; and

[0014] A controller is electrically connected to the main pump and the main valve of the engineering machinery to control the actions of the main pump and the main valve,

[0015] It is characterized in that the controller is configured as follows:

[0016] Detect the closing signal of the hydraulic lock master switch;

[0017] Detect the opening signal of the hydraulic lock relay;

[0018] When the controller does not detect the closing signal of the hydraulic lock master switch and detects the opening signal of the hydraulic lock relay, the controller sends an electrical signal to the main pump and the main valve to control the main pump and the main valve to be in a working state.

[0019] In the above-mentioned electro-hydraulic control system, the controller makes a logical relationship judgment based on the closing / non-closing signal of the hydraulic lock main switch and the opening / closing signal of the hydraulic lock relay, and controls whether the main pump and the main valve need to output normally according to the judgment result, thereby avoiding malfunction of the actuator caused by accidental touching or misoperation of the operating handle, eliminating safety hazards, enhancing the safety control level, and achieving control and safety requirements at the lowest cost.

[0020] Advantageously, the controller is electrically connected to the closed position of the hydraulic lock master switch to detect the closing signal of the hydraulic lock master switch, and

[0021] The controller is electrically connected to a position downstream of the hydraulic lock relay and upstream of the hydraulic lock solenoid valve to detect an on signal of the hydraulic lock relay.

[0022] Advantageously, the controller is configured to control the main pump and the main valve to be in a non-working state in one of the following situations:

[0023] -The controller detects the closing signal of the hydraulic lock master switch and does not detect the opening signal of the hydraulic lock relay;

[0024] -The controller does not detect the closing signal of the hydraulic lock master switch, and does not detect the opening signal of the hydraulic lock relay;

[0025] -The controller detects the closing signal of the hydraulic lock master switch and the opening signal of the hydraulic lock relay.

[0026] Advantageously, when the hydraulic lock solenoid valve is energized, pilot hydraulic oil can be delivered to the operating handle.

[0027] According to another aspect of the present invention, it relates to an electro-hydraulic control method for an engineering machine, the engineering machine comprising:

[0028] Hydraulic lock master switch;

[0029] A hydraulic lock relay electrically connected to the hydraulic lock master switch;

[0030] A hydraulic lock solenoid valve electrically connected to the hydraulic lock relay; and

[0031] A controller is electrically connected to the main pump and the main valve of the engineering machinery to control the actions of the main pump and the main valve,

[0032] Characterized in that the electro-hydraulic control method comprises:

[0033] Detecting the closing signal of the hydraulic lock master switch through the controller;

[0034] Detecting the opening signal of the hydraulic lock relay through the controller;

[0035] When the controller does not detect a closing signal from the hydraulic lock master switch and detects an opening signal from the hydraulic lock relay, the controller sends an electrical signal to the main pump and the main valve so as to put the main pump and the main valve into a working state.

[0036] Advantageously, the controller is electrically connected to the closed position of the hydraulic lock master switch to detect the closing signal of the hydraulic lock master switch, and

[0037] The controller is electrically connected to a position downstream of the hydraulic lock relay and upstream of the hydraulic lock solenoid valve to detect an on signal of the hydraulic lock relay.

[0038] Advantageously, in one of the following situations, the controller controls the main pump and the main valve to be in a non-working state:

[0039] -The controller detects the closing signal of the hydraulic lock master switch and does not detect the opening signal of the hydraulic lock relay;

[0040] -The controller does not detect the closing signal of the hydraulic lock master switch, and does not detect the opening signal of the hydraulic lock relay;

[0041] -The controller detects the closing signal of the hydraulic lock master switch and the opening signal of the hydraulic lock relay.

[0042] Advantageously, when the hydraulic lock solenoid valve is energized, pilot hydraulic oil is delivered to the operating handle.

[0043] According to another aspect of the present invention, there is provided an engineering machine, which comprises the electro-hydraulic control system as described above.

[0044] Advantageously, the construction machine is an excavator. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The preferred embodiments of the present invention will be described in more detail below with reference to the schematic drawings. The drawings and corresponding embodiments are for illustrative purposes only and are not intended to limit the present invention. In the drawings:

[0046] Figure 1 The following schematically shows an electro-hydraulic control system commonly used in engineering machinery in the prior art.

[0047] Figure 2 The following schematically shows an electro-hydraulic control system for engineering machinery according to an embodiment of the present invention.

[0048] Figure 3 The invention schematically shows a hydraulic lock control method in an electro-hydraulic control system of the prior art, and

[0049] Figure 4 The hydraulic lock control method in the electro-hydraulic control system according to the present invention is schematically illustrated. DETAILED DESCRIPTION

[0050] Embodiments of the present invention are described below with reference to the accompanying drawings. In the following description, many specific details are set forth so that those skilled in the art can more fully understand and implement the present invention. However, it is obvious to those skilled in the art that the present invention may be implemented without some of these specific details. In addition, it should be understood that the present invention is not limited to the specific embodiments described. On the contrary, any combination of the features and elements described below may be considered to implement the present invention, regardless of whether they relate to different embodiments. Therefore, the aspects, features, embodiments and advantages described below are for illustrative purposes only and should not be regarded as elements or limitations of the claims unless clearly stated in the claims.

[0051] Figure 4 The hydraulic lock control method in the electro-hydraulic control system according to the present invention is schematically shown. Figure 4 As shown, on the one hand, the controller 4 is electrically connected to the closed position of the hydraulic lock main switch 1 to detect the closing signal of the hydraulic lock main switch 1, and on the other hand, the controller 4 is electrically connected to a position downstream of the hydraulic lock relay 2 and upstream of the hydraulic lock solenoid valve 3 to detect the opening signal of the hydraulic lock relay 2.

[0052] When the hydraulic lock master switch 1 is not turned on, the hydraulic lock master switch 1 is in the normally closed position. At this time, the controller 4 detects the closing signal of the hydraulic lock master switch 1. Figure 2 As shown, when both the hydraulic lock master switch 1 and the hydraulic lock relay 2 are functioning normally, after the engine is started, when the operator turns on the hydraulic lock master switch 1, the circuit is connected, and the electrical signal turns on the hydraulic lock solenoid valve 3 through the hydraulic lock relay 2. At this time, the controller 4 cannot detect the closing signal of the hydraulic lock master switch 1 (in other words, the controller 4 determines that the hydraulic lock master switch 1 is in the open state), and the controller 4 detects the opening signal of the hydraulic lock relay 2. The controller 4 sends an electrical signal to the main pump 13 of the engineering machinery and the main valve core control port (electrical control) 7, 8 of the main valve 11, so as to control the main pump 13 and the main valve 11 to be in the working state. The pilot oil from the pilot oil circuit (pilot pump or pressure reducing valve) is connected to provide the pilot hydraulic fluid required for the operation action. At this time, when the operating handle 6 is operated, the pilot oil is delivered to the main valve core control port (hydraulic control) 9, 10 at both ends of the main valve 11, and the main valve 11 is opened to deliver the hydraulic oil from the main pump 13 to the hydraulic actuator 12.

[0053] According to the present invention, the controller 4 performs logical analysis on the electrical signal (closed or non-closed signal) from the hydraulic lock main switch 1 and the electrical signal (open or closed signal) from the hydraulic lock relay 2. Only when the controller 4 does not detect the closed signal of the hydraulic lock main switch 1 and detects the open signal of the hydraulic lock relay 2, the controller 4 sends an electrical signal to the main pump and the main valve to control the main pump and the main valve to be in a working state.

[0054] Table 1 shows that the controller 4 performs logic analysis based on the states of the hydraulic lock master switch 1 and the hydraulic lock relay 2 and controls the main pump and the main valve according to the determination result.

[0055] Hydraulic lock master switch Hydraulic lock relay Controller Main pump and main valve OFF OFF OFF OFF ON OFF OFF OFF OFF ON OFF OFF ON ON ON ON

[0056] Table 1

[0057] As shown in Table 1, when the controller 4 detects a closing signal from the hydraulic lock master switch 1, the controller 4 determines that the hydraulic lock master switch 1 is in a closed state (OFF). When the controller 4 does not detect a closing signal from the hydraulic lock master switch 1, the controller 4 determines that the hydraulic lock master switch 1 is in an open state (ON). When the controller 4 detects an opening signal from the hydraulic lock relay 2, the controller determines that the hydraulic lock relay 2 is in an open / connected state (ON). When the controller 4 does not detect an opening signal from the hydraulic lock relay 2, the controller determines that the hydraulic lock relay 2 is in a closed / disconnected state (OFF).

[0058] When the functions of any one of the hydraulic lock master switch 1 and the hydraulic lock relay 2 fail or fail at the same time or the feedback is in abnormal operation, the controller 4 gives a judgment result of OFF through logical analysis, that is, the controller 4 determines that the machine is in a state of not being able to work normally, and the controller 4 notifies the main pump 13 and the main valve 11 at both ends to control the electric proportional pressure reducing valves 7 and 8 (electrically controlled) that control the reversal of the main valve core to stop working, and the whole vehicle does not move. At this time, the main pump 13 and the main valve 11 are in a locked state, the main pump 13 is adjusted to the minimum output flow, and the main valve 11 does not respond to the pilot pressure and the control signal from the operating handle 6. Therefore, even if the operating handle 6 is misoperated or accidentally touched, no hydraulic oil enters the actuator, so no malfunction occurs.

[0059] Only when the controller 4 determines that the hydraulic lock master switch 1 is in the open state (ON) and the hydraulic lock relay 2 is in the open / connected state (ON), the controller 4 gives a determination result of ON through logical analysis, indicating that the hydraulic lock master switch 1 and the hydraulic relay 2 function normally and the hydraulic lock master switch 1 is turned on, and the controller 4 sends an electrical signal to the main pump 13 and the main valve 11 to control the main pump and the main valve to be in a working state. This enhances the safety control level of the control system.

[0060] In addition, if the controller 4 determines that the hydraulic lock master switch 1 is in the on state (ON), but simultaneously determines that the hydraulic lock relay 2 is in the off / disconnected state (OFF), it indicates that the hydraulic lock relay 2 is faulty.

[0061] The electro-hydraulic control system according to the present invention transmits a feedback signal to the controller 4 by electrically connecting the controller 4 to the closed position of the hydraulic lock master switch 1, and adds a wire between the controller 4 and a position downstream of the hydraulic lock relay 2 and upstream of the hydraulic lock solenoid valve 3 to transmit the feedback signal to the controller 4. The controller 4 makes a logical relationship judgment based on the closed / non-closed signal of the hydraulic lock master switch 1 and the open / closed signal of the hydraulic lock relay 2, and controls the main pump 13 and the main valve 11 to output normally according to the judgment result, thereby avoiding misoperation, eliminating safety hazards, enhancing the safety control level, and achieving control and safety requirements at the lowest cost. In addition, it can also be determined whether the hydraulic lock relay is damaged.

[0062] Industrial Applicability

[0063] The electro-hydraulic control system according to the present invention improves the safety of engineering machinery through simple structural improvements, and realizes control and safety requirements at a minimum cost. This safety design logic is applicable to engineering machinery such as excavators, loaders and other types of machinery with similar working conditions.

[0064] After the engine is started, when the operator turns on the hydraulic lock master switch 1, the controller 4 controls the main pump 13 and the main valve 11 to be in a non-working state in one of the following situations:

[0065] -The controller detects the closing signal of the hydraulic lock master switch and does not detect the opening signal of the hydraulic lock relay;

[0066] -The controller does not detect the closing signal of the hydraulic lock master switch, and does not detect the opening signal of the hydraulic lock relay;

[0067] -The controller detects the closing signal of the hydraulic lock master switch and the opening signal of the hydraulic lock relay.

[0068] When and only when the controller 4 does not detect the closing signal of the hydraulic lock master switch and detects the opening signal of the hydraulic lock relay, the controller 4 controls the main pump 13 and the main valve 11 to be in the working state.

[0069] The electro-hydraulic control system and method of the present invention are described above with the aid of specific embodiments. It is obvious to those skilled in the art that various modifications and variations may be made to the embodiments disclosed above without departing from the scope or spirit of the present invention. For example, the implementation of the present invention may not include some of the specific features described, and the present invention is not limited to the specific embodiments described, but rather any combination of the described features and elements may be envisioned. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the disclosed electro-hydraulic control system and method. The specification and examples are to be regarded as exemplary only, with the true scope being represented by the appended claims and their equivalents.

Claims

1. An electro-hydraulic control system for engineering machinery, comprising: Hydraulic lock master switch (1); A hydraulic lock relay (2) electrically connected to the hydraulic lock master switch; A hydraulic lock solenoid valve (3) electrically connected to the hydraulic lock relay; and A controller (4) is electrically connected to a main pump (13) and a main valve (11) of the engineering machine so as to control the operation of the main pump and the main valve. It is characterized in that the controller is configured as follows: Detect the closing signal of the hydraulic lock master switch; Detect the opening signal of the hydraulic lock relay; When the controller does not detect the closing signal of the hydraulic lock master switch and detects the opening signal of the hydraulic lock relay, the controller sends an electrical signal to the main pump and the main valve to control the main pump and the main valve to be in a working state.

2. The electro-hydraulic control system according to claim 1, wherein: The controller is electrically connected to the closed position of the hydraulic lock master switch to detect the closing signal of the hydraulic lock master switch, and The controller is electrically connected to a position downstream of the hydraulic lock relay and upstream of the hydraulic lock solenoid valve to detect an on signal of the hydraulic lock relay.

3. The electro-hydraulic control system according to claim 1 or 2, wherein: The controller is configured to control the main pump and the main valve to be in a non-working state in one of the following situations: The controller detects the closing signal of the hydraulic lock master switch and does not detect the opening signal of the hydraulic lock relay; The controller does not detect the closing signal of the hydraulic lock master switch, and does not detect the opening signal of the hydraulic lock relay; The controller detects the closing signal of the hydraulic lock master switch and detects the opening signal of the hydraulic lock relay.

4. The electro-hydraulic control system according to claim 1 or 2, wherein: When the hydraulic lock solenoid valve is energized, the pilot hydraulic oil can be delivered to the operating handle (6).

5. An electro-hydraulic control method for an engineering machine, the engineering machine comprising: Hydraulic lock master switch (1); A hydraulic lock relay (2) electrically connected to the hydraulic lock master switch; A hydraulic lock solenoid valve (3) electrically connected to the hydraulic lock relay; and A controller (4) is electrically connected to a main pump (13) and a main valve (11) of the engineering machine so as to control the operation of the main pump and the main valve. Characterized in that the electro-hydraulic control method comprises: Detecting the closing signal of the hydraulic lock master switch through the controller; Detecting the opening signal of the hydraulic lock relay through the controller; When the controller does not detect a closing signal from the hydraulic lock master switch and detects an opening signal from the hydraulic lock relay, the controller sends an electrical signal to the main pump and the main valve so as to put the main pump and the main valve into a working state.

6. The electro-hydraulic control method according to claim 5, wherein: The controller is electrically connected to the closed position of the hydraulic lock master switch to detect the closing signal of the hydraulic lock master switch, and The controller is electrically connected to a position downstream of the hydraulic lock relay and upstream of the hydraulic lock solenoid valve to detect an on signal of the hydraulic lock relay.

7. The electro-hydraulic control method according to claim 5 or 6, wherein: In one of the following situations, the controller controls the main pump and main valve to be in a non-working state: The controller detects the closing signal of the hydraulic lock master switch and does not detect the opening signal of the hydraulic lock relay; The controller does not detect the closing signal of the hydraulic lock master switch, and does not detect the opening signal of the hydraulic lock relay; The controller detects the closing signal of the hydraulic lock master switch and detects the opening signal of the hydraulic lock relay.

8. The electro-hydraulic control method according to claim 5 or 6, wherein: When the hydraulic lock solenoid valve is energized, pilot hydraulic oil is delivered to the operating handle (6).

9. An engineering machine, comprising an electro-hydraulic control system according to any one of claims 1 to 4.

10. The construction machine according to claim 9, wherein: The construction machine is an excavator.

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