Excavator control system and control method

Abstract

The present application relates to a kind of excavator line control reconstruction device and control method thereof, and the reconstruction device includes valve block assembly, electric cylinder assembly and mounting bracket;Valve block assembly includes valve plate, shuttle valve and foot valve, shuttle valve and foot valve are installed on valve plate, and the inside of valve plate is provided with the hydraulic passage corresponding to the inlet and outlet of shuttle valve and foot valve;Two ends of shuttle valve input oil port are connected with the output oil port of valve plate, handle control valve in excavator cab and foot valve;Electric cylinder assembly includes conversion mechanism and electric cylinder;Conversion mechanism includes conversion bracket, sliding bearing, cam conversion block, electric cylinder connecting frame and intermediate shaft;The upper support of conversion bracket is rotatably connected with cam conversion block;The cam top rod connecting pair is formed in the bottom profile of cam conversion block and the valve core connecting place of foot valve.The present application can realize the switching of remote control and local operation, solve the problems of large workload, low efficiency and poor adaptability in conventional reconstruction.

Description

Technical Field

[0001] This invention relates to the field of excavator wire control technology, and more specifically, to an excavator wire control retrofit device and its control method. Background Technology

[0002] Currently, excavators are widely used in mining, housing construction, municipal engineering, and emergency rescue projects. They often operate in harsh environments with high risks, thus increasing the demand for remote control operation of excavators. Conventional wired control retrofits for excavators involve adding solenoid valves to replace the original hydraulic pilot valves. This requires matching the characteristics of the solenoid valves with the characteristics of the excavator's pilot valves, resulting in a large amount of work, long debugging time, and low efficiency. Furthermore, due to the inconsistent characteristics of pilot valves for different excavator models, the adaptability is poor. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a wired control retrofit device for excavators and its control method, which can realize the switching between remote control and local operation, and solves the problems of large workload, low efficiency and poor adaptability of conventional retrofit.

[0004] The technical solution adopted by the present invention to solve its technical problem is as follows: a wire-controlled retrofit device for an excavator is constructed, including a valve block assembly, an electric cylinder assembly, and a mounting bracket; the valve block assembly is connected in parallel with the excavator cab handle control valve and foot pedal valve; the mounting bracket is used to support the valve block assembly and the electric cylinder assembly;

[0005] The valve block assembly includes a valve plate, a shuttle valve, and a foot valve. The shuttle valve and the foot valve are mounted on the valve plate, and the valve plate has hydraulic passages inside that correspond to the inlet and outlet ports of the shuttle valve and the foot valve. The two inlet ports of the shuttle valve are connected to the valve plate and the outlet ports of the handle control valve and the foot valve in the excavator cab, respectively. The middle outlet port of the shuttle valve is connected to the excavator main control valve. The foot valve is configured to correspond to the handle control valve and the foot valve in the excavator cab.

[0006] The electric cylinder assembly includes a conversion mechanism and an electric cylinder; the conversion mechanism includes a conversion bracket, a sliding bearing, a cam conversion block, an electric cylinder connecting frame, and an intermediate shaft; the conversion bracket is fixedly connected to the middle position of the foot valve, the bottom support groove of the conversion bracket corresponds to the middle protrusion of the foot valve, and the upper bracket of the conversion bracket is rotatably connected to the cam conversion block; the bottom contour of the cam conversion block and the valve core of the foot valve form a cam push rod connecting pair, and when the cam conversion block rotates at a constant speed, the valve core of the foot valve can achieve linear reciprocating motion. The cam conversion block and the conversion bracket are connected by a pin, the upper end of the electric cylinder connecting frame is connected to the extension shaft of the electric cylinder, and the other end of the electric cylinder connecting frame is connected to the cam conversion block through the mounting holes of its two side brackets and the intermediate shaft; the intermediate shaft is provided with left and right rolling bearings and a middle connecting pin, the left and right rolling bearings roll in the groove of the cam conversion block, and the middle connecting pin connects to the electric cylinder connecting frame; after the electric cylinder is connected to the conversion mechanism, it is installed on the foot valve, and the output shaft of the electric cylinder is coaxial with the valve core assembly of the foot valve to ensure that the valve core assembly of the foot valve is subjected to force along the normal direction.

[0007] In the above scheme, two sets of foot pedal valves are used to replace the handle control valve in the excavator cab. All three sets of foot pedal valves remove the upper pedal to expose the contact position of the reciprocating movement of the internal valve core assembly.

[0008] In the above scheme, the length of the output shaft of the electric cylinder is more than twice the extension length of the foot valve core assembly.

[0009] In the above scheme, the upper support of the conversion bracket is connected to the cam conversion block through a sliding bearing and a pin to ensure that the cam conversion block can rotate.

[0010] In the above scheme, the cam conversion block has symmetrical slots on both sides as connection interfaces with the electric cylinder.

[0011] In the above scheme, the upper end of the electric cylinder connecting bracket has a threaded through hole for connecting with the extension shaft of the electric cylinder.

[0012] In the above scheme, the right side of the mounting bracket is provided with a mounting hole for connection with the valve plate screw.

[0013] In the above scheme, a support frame is provided at the bottom of the mounting bracket, the support frame is fixedly connected to the electric cylinder mounting seat, and the height of the electric cylinder mounting seat is adjusted by shims.

[0014] The present invention also provides a control method for the excavator drive-by-wire retrofit device, comprising the following steps:

[0015] The pressure output of each pilot valve of the excavator is controlled by the reciprocating motion of the output shaft of the electric cylinder remotely. When the output shaft of the electric cylinder is in the middle zero position, the pair of valve core components corresponding to the upper part of the foot valve do not move, and there is no pressure output to the main control valve of the excavator, so the excavator does not move.

[0016] When the electric cylinder output shaft extends downward from the zero position, it drives the cam converter block to rotate counterclockwise. Through the action of the cam push rod pair, the first set of valve cores in contact with the foot valve moves downward, opening the valve port and gradually increasing it. The output end has a corresponding pressure output to the excavator's main control valve, thereby controlling the excavator to perform related actions. The second set of valve cores does not contact the cam converter block and remains at the zero position. When the electric cylinder output shaft retracts upward from the current position back to the zero position, the first set of valve cores moves upward, gradually closing the valve port. The output end pressure gradually decreases, and the second set of valve cores does not contact the cam converter block and remains at the zero position. The excavator gradually stops moving.

[0017] When the output shaft of the electric cylinder continues to retract upward from the zero position, the first set of valve cores does not contact the cam conversion block and remains at the zero position, while the second set of valve cores contacts the cam conversion block and moves downward, thereby controlling the excavator to perform the opposite action; through the reciprocating motion of the electric cylinder, the hydraulic cylinders and hydraulic motors of the excavator are controlled to perform corresponding actions respectively.

[0018] The excavator wire-controlled retrofit device and its control method according to the present invention have the following beneficial effects:

[0019] 1. The device of this invention is connected in parallel with the handle control valve and foot valve of the original excavator cab to drive the main control valve of the excavator. The electric cylinder assembly controls three sets of foot valves of the same type to realize the wired control of the excavator. At the same time, the modification device is an integrated structure connected in parallel with the original control components of the excavator cab, which can realize the switching between remote control and local operation, and solves the problems of large workload, low efficiency and poor adaptability of conventional modification.

[0020] 2. This invention adopts a foot pedal valve and electric cylinder assembly of the same type as those used in excavators to form an integrated structure, which reduces the amount of modification work, improves efficiency, and ensures applicability to different models of excavators. Attached Figure Description

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0022] Figure 1 This is the hydraulic schematic diagram of the excavator's wire-controlled retrofit device;

[0023] Figure 2 This is an overall outline drawing of the excavator's wire-controlled retrofit device;

[0024] Figure 3 This is a schematic diagram of the valve block assembly;

[0025] Figure 4 This is a schematic diagram of the electric cylinder assembly;

[0026] Figure 5 This is a schematic diagram of the conversion mechanism;

[0027] Figure 6 This is a schematic diagram of the conversion bracket;

[0028] Figure 7 This is a schematic diagram of a cam converter block;

[0029] Figure 8 This is a diagram of the mounting bracket;

[0030] Figure 2-6 In the middle: 1. Valve block assembly, 1.1 Valve plate, 1.2 Shuttle valve, 1.3 Foot valve, 2. Electric cylinder assembly, 2.1 Conversion mechanism, 2.1.1 Conversion bracket, 2.1.2 Sliding bearing, 2.1.3 Cam conversion block, 2.1.4 Electric cylinder connecting frame, 2.1.5 Intermediate shaft, 2.2 Electric cylinder, 3. Mounting bracket. Detailed Implementation

[0031] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0032] like Figure 1-8 As shown, the excavator wire control retrofit device of the present invention includes a valve block assembly 1, an electric cylinder assembly 2, and a mounting bracket 3.

[0033] like Figure 1 The hydraulic schematic diagram shows that the excavator's wired control retrofit device is connected in parallel with the handle control valve and foot valve in the excavator's cab via hydraulic hoses. The output end is connected to the excavator's main control valve via a shuttle valve and hydraulic hoses, thereby realizing the switching between remote control and local operation.

[0034] Valve block assembly 1 includes a valve plate 1.1, a shuttle valve 1.2, and a foot valve 1.3. The valve plate 1.1 serves as the mounting base for the shuttle valve 1.2 and the foot valve 1.3, and its internal hydraulic passages correspond to the inlet and outlet ports of the shuttle valve 1.2 and the foot valve 1.3. The shuttle valve 1.2 has twelve sets of output ports mounted on the side of the valve plate 1.1. The two end inlet ports of the shuttle valve 1.2 are connected to the hydraulic hoses of the valve plate 1.1 and the output ports of the handle control valve and foot valve in the excavator cab, respectively. The middle output port is connected to the excavator's main control valve.

[0035] The foot valve 1.3 is the same model and specification as the foot valve inside the excavator. Three sets of foot valves 1.3 are set up to correspond to the handle control valve and foot valve in the excavator cab. In order to reduce the number of subsequent remote control electric cylinder components 2, two sets of foot valves 1.3 are used to replace the handle control valve in the excavator cab. At the same time, the upper pedal of all three sets of foot valves 1.3 is removed to expose the contact position of the reciprocating motion of the internal valve core component.

[0036] The electric cylinder assembly 2 includes a conversion mechanism 2.1 and an electric cylinder 2.2. The conversion mechanism 2.1 includes a conversion bracket 2.1.1, a sliding bearing 2.1.2, a cam conversion block 2.1.3, an electric cylinder connecting bracket 2.1.4, and an intermediate shaft 2.1.5.

[0037] The conversion bracket 2.1.1 is fixedly connected to the middle position of the foot valve 1.3 by screws. Its bottom support groove corresponds to the middle protrusion of the foot valve 1.3. The upper bracket and the cam conversion block 2.1.3 are connected via a sliding bearing 2.1.2 and a pin to ensure the cam conversion block 2.1.3 can rotate. The bottom contour of the cam conversion block 2.1.3 and the valve core of the foot valve 1.3 form a cam push rod connection pair. When the cam conversion block 2.1.3 rotates at a constant speed, the valve core of the foot valve 1.3 can achieve linear reciprocating motion. The cam conversion block 2.1.3 has a through hole in the middle, which is connected to the conversion bracket 2.1.1 via a pin. Symmetrical slots on both sides serve as connection interfaces with the electric cylinder 2.2. The electric cylinder connecting bracket 2.1.4 has a threaded through hole at its upper end, which connects to the extension shaft of the electric cylinder 2.2. The other end is connected to the cam conversion block 2.1.3 via mounting holes on both sides and a middle shaft 2.1.5.

[0038] The intermediate shaft 2.1.5 includes two sets of left and right rolling bearings and a central connecting pin. The left and right rolling bearings roll within the slots of the cam conversion block 2.1.3, and the central connecting pin connects to the electric cylinder connecting bracket 2.1.4. After the electric cylinder 2.2 is connected to the conversion mechanism 2.1, it is installed on the foot valve 1.3. The output shaft of the electric cylinder 2.2 is coaxial with the valve core assembly of the foot valve 1.3 to ensure that the valve core assembly of the foot valve 1.3 is subjected to force along the normal direction. The length of the output shaft of the electric cylinder 2.2 is selected according to the reciprocating distance of the valve core of the foot valve 1.3 and must be more than twice the extended length of the valve core assembly of the foot valve 1.3.

[0039] Mounting bracket 3 is used for support and protection of the wired control retrofit device. It has a mounting hole on the right side and is connected to valve plate 1.1 by screws. It has a support frame at the bottom and is connected to electric cylinder 2.2 mounting base by screws. The height of electric cylinder 2.2 mounting base is adjusted by shims to ensure that the output shaft of electric cylinder 2.2 is coaxial with the valve core output end of foot valve 1.3.

[0040] The present invention also provides a control method for the above-mentioned excavator drive-by-wire retrofit device, which specifically includes the following steps:

[0041] The pressure output of each pilot valve of the excavator is controlled by the reciprocating motion of the output shaft of the electric cylinder 2.2 remotely. Figure 4As shown, when the output shaft of the electric cylinder 2.2 is in the middle zero position, the pair of valve core assemblies corresponding to the upper part of the foot valve 1.3 are not moving, and there is no pressure output to the excavator's main control valve, so the excavator does not move. When the output shaft of the electric cylinder 2.2 extends downward from the zero position, it drives the cam conversion block 2.1.3 to rotate counterclockwise. Through the action of the cam push rod pair, the first set of valve cores corresponding to the pair of valve cores of the foot valve 1.3 moves downward, the valve opening gradually increases, and there is corresponding pressure output to the excavator's main control valve, thereby controlling the excavator to perform relevant actions. The second set of valve cores does not contact the cam conversion block 2.1.3 and remains in the zero position. When the output shaft of electric cylinder 2.2 retracts upward from its current position to the zero position, the first set of valve cores moves upward and the valve port gradually closes, the output pressure gradually decreases, and the second set of valve cores does not contact the cam conversion block 2.1.3 and remains at the zero position, and the excavator gradually stops moving; when the output shaft of electric cylinder 2.2 continues to retract upward from the zero position, the first set of valve cores does not contact the cam conversion block 2.1.3 and remains at the zero position, while the second set of valve cores contacts the cam conversion block 2.1.3 and moves downward, thereby controlling the excavator to perform the opposite action; through the reciprocating motion of electric cylinder 2.2, the hydraulic cylinders and hydraulic motors of each actuator of the excavator are controlled to perform corresponding actions.

[0042] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A device for retrofitting an excavator with wired control, characterized in that, It includes a valve block assembly, an electric cylinder assembly, and a mounting bracket; the valve block assembly is connected in parallel with the excavator cab handle control valve and foot pedal valve; the mounting bracket is used to support the valve block assembly and the electric cylinder assembly. The valve block assembly includes a valve plate, a shuttle valve, and a foot valve. The shuttle valve and the foot valve are mounted on the valve plate, and the valve plate has hydraulic passages inside that correspond to the inlet and outlet ports of the shuttle valve and the foot valve. The two inlet ports of the shuttle valve are connected to the valve plate and the outlet ports of the handle control valve and the foot valve in the excavator cab, respectively. The middle outlet port of the shuttle valve is connected to the excavator main control valve. The foot valve is configured to correspond to the handle control valve and the foot valve in the excavator cab. The electric cylinder assembly includes a conversion mechanism and an electric cylinder; the conversion mechanism includes a conversion bracket, a sliding bearing, a cam conversion block, an electric cylinder connecting frame, and an intermediate shaft; the conversion bracket is fixedly connected to the middle position of the foot valve, the bottom support groove of the conversion bracket corresponds to the middle protrusion of the foot valve, and the upper bracket of the conversion bracket is rotatably connected to the cam conversion block; the bottom contour of the cam conversion block and the valve core of the foot valve form a cam push rod connecting pair, and when the cam conversion block rotates at a constant speed, the valve core of the foot valve can achieve linear reciprocating motion. The cam conversion block and the conversion bracket are connected by a pin, the upper end of the electric cylinder connecting frame is connected to the extension shaft of the electric cylinder, and the other end of the electric cylinder connecting frame is connected to the cam conversion block through the mounting holes of its two side brackets and the intermediate shaft; the intermediate shaft is provided with left and right rolling bearings and a middle connecting pin, the left and right rolling bearings roll in the groove of the cam conversion block, and the middle connecting pin connects to the electric cylinder connecting frame; after the electric cylinder is connected to the conversion mechanism, it is installed on the foot valve, and the output shaft of the electric cylinder is coaxial with the valve core assembly of the foot valve to ensure that the valve core assembly of the foot valve is subjected to force along the normal direction; Two sets of foot pedal valves are used to replace the handle control valve in the excavator cab. All three sets of foot pedal valves have their upper pedals removed to expose the contact position of the reciprocating valve core assembly inside. The cam conversion block has symmetrical slots on both sides as connection interfaces with the electric cylinder.

2. The excavator drive-by-wire retrofit device according to claim 1, characterized in that, The output shaft length of the electric cylinder is more than twice the extension length of the foot valve core assembly.

3. The excavator drive-by-wire retrofit device according to claim 1, characterized in that, The upper support of the conversion bracket is connected to the cam conversion block through a sliding bearing and a pin to ensure that the cam conversion block can rotate.

4. The excavator drive-by-wire retrofit device according to claim 1, characterized in that, The upper end of the electric cylinder connecting bracket has a threaded through hole for connecting with the extension shaft of the electric cylinder.

5. The excavator wire-controlled retrofit device according to claim 1, characterized in that, The mounting bracket has mounting holes on its right side for connection with valve plate screws.

6. The excavator drive-by-wire retrofit device according to claim 1, characterized in that, The mounting bracket is provided with a support frame at the bottom, which is fixedly connected to the electric cylinder mounting seat, and the height of the electric cylinder mounting seat is adjusted by shims.

7. A control method for the excavator drive-by-wire retrofit device according to any one of claims 1-6, characterized in that, Includes the following steps: The pressure output of each pilot valve of the excavator is controlled by the reciprocating motion of the output shaft of the electric cylinder remotely. When the output shaft of the electric cylinder is in the middle zero position, the pair of valve core components corresponding to the upper part of the foot valve do not move, and there is no pressure output to the main control valve of the excavator, so the excavator does not move. When the electric cylinder output shaft extends downward from the zero position, it drives the cam converter block to rotate counterclockwise. Through the action of the cam push rod pair, the first set of valve cores in contact with the foot valve moves downward, opening the valve port and gradually increasing it. The output end has a corresponding pressure output to the excavator's main control valve, thereby controlling the excavator to perform related actions. The second set of valve cores does not contact the cam converter block and remains at the zero position. When the electric cylinder output shaft retracts upward from the current position back to the zero position, the first set of valve cores moves upward, gradually closing the valve port. The output end pressure gradually decreases, and the second set of valve cores does not contact the cam converter block and remains at the zero position. The excavator gradually stops moving. When the output shaft of the electric cylinder continues to retract upward from the zero position, the first set of valve cores does not contact the cam conversion block and remains at the zero position, while the second set of valve cores contacts the cam conversion block and moves downward, thereby controlling the excavator to perform the opposite action; through the reciprocating motion of the electric cylinder, the hydraulic cylinders and hydraulic motors of the excavator are controlled to perform corresponding actions respectively.

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