A hydraulic system for excavator attachment and boom swing and excavator

Abstract

This invention discloses a hydraulic system for boom swaying and attachments on an excavator, and the excavator itself. The system includes a controller, a proportional valve, a main control valve, a directional control valve, a main pump, a boom sway cylinder, and attachments. The controller has a right input section and a left input section. The proportional valve is electrically connected to the controller and the main control valve. The main pump is connected to the main control valve via an oil circuit, and the main control valve is connected to the directional control valve via an oil circuit. The boom sway cylinder and attachments are both connected to the directional control valve via oil circuits. The controller controls the opening of the proportional valve, and the proportional valve controls the opening of the main control valve. This invention, applied to the hydraulic system for boom swaying and attachments on an excavator, achieves two operability requirements (meeting customer needs) by adding a controller and a proportional valve, and controlling the main control valve through the proportional valve. Furthermore, the controller can set the maximum flow rate for attachment rotation, allowing for adjustable maximum attachment rotation speed to meet different customer speed requirements.

Description

Technical Field

[0001] This invention relates to the field of excavator technology, and more particularly to a hydraulic system for the swaying of the boom and arm of an excavator, and the excavator itself. Background Technology

[0002] In mini excavators, due to limited space, it's difficult to achieve independently controlled attachment rotation by adding a separate main control valve. Therefore, a nine-unit main valve is typically used. Besides the eight functions for the normal operation of the machine, the extra unit is for auxiliary high-flow functions. When certain attachments require rotation and clamping functions, a single auxiliary high-flow unit is insufficient. In such cases, a separate main control valve needs to be selected to implement the attachment rotation function.

[0003] To achieve the attachment slewing function, a switching mechanism is used that combines boom yaw motion with attachment slewing, achieved via a solenoid switching valve. By default, the solenoid switching valve is de-energized, enabling boom yaw. When the solenoid switching valve is energized, its valve core reverses direction, enabling the attachment slewing function.

[0004] The aforementioned hydraulic system enables boom yaw and attachment slewing movements. However, the boom yaw valve spool is asymmetrical, resulting in inconsistent flow rates when yawing left and right. Consequently, when switching to attachment slewing, the left and right slewing speeds will be inconsistent. Furthermore, in this hydraulic system, attachment slewing is controlled by a foot-operated pilot valve, leading to incoordination and stiffness when simultaneously operating the attachment and the vehicle. Additionally, if the flow rate of the boom yaw valve spool is insufficient for the attachment slewing flow rate, the valve spool needs to be replaced. Summary of the Invention

[0005] To overcome at least one of the defects described in the prior art, this invention provides a hydraulic system for the yaw motion of an excavator's attachment and boom. By adding a controller and a proportional valve, the main control valve is controlled via the proportional valve, allowing for the controllability of achieving two actions that meet customer requirements within the same valve core state. Furthermore, the maximum flow rate for attachment rotation can be set via the controller, enabling adjustable maximum attachment rotation speed to meet different customer speed requirements.

[0006] In order to overcome at least one of the defects described in the prior art, the present invention provides an excavator having a hydraulic system for the attachment swing arm, which enables the excavator to achieve adjustable maximum attachment swing speed to meet different customer speed requirements.

[0007] The technical solution adopted by this invention to solve its problem is:

[0008] A hydraulic system for boom swaying and attachments of an excavator includes a controller, a proportional valve, a main control valve, a directional valve, a main pump, a boom swaying cylinder, and attachments.

[0009] The controller is connected to a right input section and a left input section;

[0010] The proportional valve is electrically connected to the controller, and the proportional valve is also connected to the main control valve oil circuit.

[0011] The main pump is connected to the main control valve oil circuit, the main control valve is connected to the reversing valve oil circuit, and the boom swing cylinder and the attachment are both connected to the reversing valve oil circuit.

[0012] The controller controls the opening degree of the proportional valve, and the proportional valve controls the opening degree of the main control valve.

[0013] Furthermore: the reversing valve includes a first oil outlet, a second oil outlet, a third oil outlet and a fourth oil outlet arranged in parallel; the boom sway cylinder is connected to the first oil outlet and the third oil outlet in an oil circuit; and the attachment is connected to the second oil outlet and the fourth oil outlet in an oil circuit.

[0014] The reversing valve further includes a first oil inlet and a second oil inlet, and the first oil outlet and the third oil outlet are simultaneously connected to the first oil inlet and the second oil inlet, respectively, or the second oil outlet and the fourth oil outlet are simultaneously connected to the first oil inlet and the second oil inlet, respectively.

[0015] Furthermore, the reversing valve includes a reversing signal input section; the reversing signal input section inputs a signal to control the first oil inlet to be connected with the first oil outlet and the second oil outlet, and also controls the second oil inlet to be connected with the third oil outlet and the fourth oil outlet.

[0016] Furthermore, the proportional valve includes a first pilot valve and a second pilot valve, the first pilot valve and the second pilot valve respectively controlling the opposite ends of the main valve core of the main control valve.

[0017] Furthermore: the main valve core of the main control valve controls the main control valve to connect with the oil circuit of the first oil inlet or the second oil inlet.

[0018] Furthermore: the right input section and the left input section are respectively the right-hand rotation section and the left-hand rotation section of the handle dial, and the right-hand rotation section and the left-hand rotation section of the handle dial are electrically connected to the first pilot valve and the second pilot valve through the controller.

[0019] Furthermore, the boom sway cylinder has a large boom sway cylinder chamber and a small boom sway cylinder chamber, and the large boom sway cylinder chamber and the small boom sway cylinder chamber are respectively connected to the first oil outlet and the third oil outlet oil passage.

[0020] Furthermore: the attachment is connected to a rotary motor, the rotary motor is provided with a left rotary liquid inlet and a right rotary liquid inlet, the left rotary liquid inlet and the right rotary liquid inlet are respectively connected to the oil circuits of the second oil outlet and the fourth oil outlet.

[0021] Furthermore, the main pump is connected to a main pump hydraulic oil tank.

[0022] An excavator includes the aforementioned hydraulic system for the excavator's auxiliary boom and arm yaw.

[0023] In summary, the hydraulic system for boom swaying of excavators provided by this invention has the following technical effects:

[0024] By setting up a controller and a proportional valve, the main control valve is controlled to open its spool, obtaining the required output flow rate. This allows for the controllability of performing two actions that meet customer requirements while maintaining the same spool state. Additionally, the controller can be used to set the maximum flow rate of the attachment's rotation, making the maximum rotation speed of the attachment adjustable to meet different customer speed requirements.

[0025] In summary, the excavator provided by this invention has the following technical effects:

[0026] This excavator features a hydraulic system for the attachments and boom sway, which allows for adjustable maximum attachment slewing speed to meet different customer speed requirements. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of an embodiment of the hydraulic system for boom swaying of an excavator.

[0028] The meanings of the reference numerals in the attached figures are as follows:

[0029] 1. Controller; 2. Proportional valve; 3. Main control valve; 4. Boom yaw cylinder; 5. Main pump; 6. Main pump hydraulic oil tank; 7. Directional valve; 8. Attachment; 11. Right input unit; 12. Left input unit. Detailed Implementation

[0030] To better understand and implement this invention, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings.

[0031] In the description of this invention, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0033] See Figure 1 The present invention discloses a hydraulic system for boom swaying of excavator attachments, including a controller 1, a proportional valve 2, a main control valve 3, a directional valve 7, a main pump 5, a boom swaying cylinder 4, and attachments 8.

[0034] The controller 1 is connected to a right input section 11 and a left input section 12.

[0035] The proportional valve 2 is electrically connected to the controller 1, and the proportional valve 2 is also connected to the main control valve 3 via an oil circuit.

[0036] The main pump 5 is connected to the main control valve 3 in the oil circuit, the main control valve 3 is connected to the directional valve 7 in the oil circuit, and the boom swing cylinder 4 and attachment 8 are both connected to the directional valve 7 in the oil circuit.

[0037] Controller 1 controls the opening of proportional valve 2, and proportional valve 2 controls the opening of main control valve 3.

[0038] Based on the above solution, this application is used in the hydraulic system of the small boom and sway of the excavator, which has at least four working states.

[0039] Operating State 1: Directional valve 7 is in operating state A1, and the system supplies oil to boom yaw cylinder 4. The operator sends a control signal to controller 1 via right input unit 11. Controller 1 outputs a signal to control proportional valve 2. Proportional valve 2 outputs pilot pressure oil at port A10 to control the valve core of main control valve 3 to state B1, causing the pressure oil from main pump 5 to enter boom yaw cylinder 4 through main control valve 3 and switching valve, achieving right boom yaw. Boom yaw cylinder 4 has a large chamber and a small chamber. Hydraulic oil entering the small chamber of boom yaw cylinder 4 causes right boom yaw. Hydraulic oil entering the large chamber of boom yaw cylinder 4 causes left boom yaw.

[0040] Operating State 2: The directional valve 7 remains in operating state A1, and the system supplies oil to the boom yaw cylinder 4. The operator sends a control signal to the controller 1 through the left input section 12. The controller 1 outputs a signal to control the proportional valve 2. The proportional valve 2 outputs pilot pressure oil at port A20 to control the valve core of the main control valve 3 to state B2, so that the pressure oil from the main pump 5 enters the large chamber of the boom yaw cylinder 4 through the main control valve 3 and the switching valve, realizing the left yaw of the boom.

[0041] Operating State 3: The directional valve 7 is in operating state A2, and the system supplies oil to the attachment 8. The operator sends a control signal to the controller 1 through the right input unit 11. The controller 1 outputs a signal to control the proportional valve 2. The proportional valve 2 outputs pilot pressure oil at port A10 to control the valve core of the main control valve 3 to state B1, so that the pressure oil from the main pump 5 enters the attachment 8 through the main control valve 3 and the switching valve, realizing the rightward rotation of the attachment 8.

[0042] Operating State 4: The directional valve 7 is still in operating state A2, and the system supplies oil to the attachment 8. The operator sends a control signal to the controller 1 through the left input section 12. The controller 1 outputs a signal to control the proportional valve 2. The pilot pressure oil output from port A20 of the proportional valve 2 controls the valve core of the main control valve 3 to state B2, so that the pressure oil from the main pump 5 enters the attachment 8 through the main control valve 3 and the switching valve, realizing the leftward rotation of the attachment 8.

[0043] In the above description of the working states, the difference between the directional valve 7 being in working state A1 and working state A2 is that the directional valve 7 is in a de-energized state and an energized state, respectively. The valve core of the main control valve 3 in state B1 and state B2 are two different positions of the valve core of the main control valve 3.

[0044] In the above technical solution, the controller 1 controls the proportional valve 2, and the A10 and A20 ports of the proportional valve 2 supply pilot pressure oil to the main control valve 3 to control the valve core position and opening of the main control valve 3. Then, the hydraulic oil of the main pump 5 enters the boom yaw cylinder 4 or attachment 8 through the controlled main control valve 3 and the reversing valve 7, so as to achieve the controllability of two actions that meet the customer requirements in the same valve core state.

[0045] In the above technical solution, to solve the problem of inconsistent left and right rotation speeds of attachment 8 in the prior art, the controller 1 can set the maximum flow rate of attachment 8 rotation. The valve core of the main control valve 3 is selected to maximize the flow rate required for boom swaying and attachment 8 rotation, keeping the valve core opening area consistent. Assuming the flow rate Q required for attachment 8 rotation is the maximum, the maximum flow rate at both ends of the core is set to Q. At this time, the boom swaying speed will increase. Therefore, the controller 1 is set to a boom swaying mode, and the required flow rate for boom swaying is set as a percentage of the flow rate Q. When the right input 11 or the left input 12 is operated, the input part outputs a voltage signal to the controller 1. The controller 1 outputs a corresponding current signal according to the maximum flow rate set by the boom swaying mode to control the opening of the proportional solenoid valve, thereby controlling the pilot oil pressure output by A10 / A20 to control the valve core opening and achieve the required output flow rate.

[0046] Therefore, in summary, the application of the technical solution of this invention to the hydraulic system of the excavator attachment and boom sway can achieve the controllability of two actions that meet customer requirements under the same valve core state, and can also achieve adjustable maximum speed of attachment rotation 8 times to meet different speed requirements of customers.

[0047] In this technical solution, the reversing valve 7 includes a first oil outlet, a second oil outlet, a third oil outlet and a fourth oil outlet arranged in parallel. The boom swing cylinder 4 is connected to the first oil outlet and the third oil outlet in oil circuit, and the attachment 8 is connected to the second oil outlet and the fourth oil outlet in oil circuit.

[0048] The reversing valve 7 also includes a first oil inlet and a second oil inlet, and a first oil outlet and a third oil outlet are simultaneously connected to the first oil inlet and the second oil inlet, respectively, or a second oil outlet and a fourth oil outlet are simultaneously connected to the first oil inlet and the second oil inlet, respectively.

[0049] The reversing valve 7 is an electromagnetic reversing valve 7, which automatically controls the connection of the first oil inlet and the second oil inlet with the first oil outlet and the third oil outlet through electrical control, or connects with the second oil outlet and the fourth oil outlet.

[0050] When the first and second oil inlets are connected to the first and third oil outlets respectively, the hydraulic oil output by the main pump 5 enters the boom yaw cylinder 4 through the reversing valve 7. When the first and second oil inlets are connected to the second and fourth oil outlets respectively, the hydraulic oil output by the main pump 5 enters the attachment 8 through the reversing valve 7, specifically into the swing motor of the attachment 8, controlling the rotation of the attachment 8.

[0051] In this technical solution, the reversing valve 7 includes a reversing signal input section. The reversing signal input section inputs a signal to control the first oil inlet to be connected to the first oil outlet and the second oil outlet, and also controls the second oil inlet to be connected to the third oil outlet and the fourth oil outlet.

[0052] The reversing signal input unit inputs an electrical signal to the reversing valve 7, so that the reversing valve 7 is energized. The reversing valve 7 is in an unenergized or energized state respectively. The reversing valve 7 is in working state A1 and working state A2 respectively. That is, the reversing valve 7 delivers the hydraulic oil delivered by the main pump 5 to the boom swing cylinder 4 and the attachment 8 respectively.

[0053] In this technical solution, the proportional valve 2 includes a first pilot valve and a second pilot valve, which respectively control the opposite ends of the main valve core of the main control valve 3. The first pilot valve and the second pilot valve control the movement of the valve core of the main control valve 3, control the direction of movement of the valve core of the main control valve 3, and further control the opening degree of the valve core of the main control valve 3.

[0054] In this technical solution, the main valve core of the main control valve 3 controls the oil circuit connection between the main control valve 3 and the first or second oil inlet. The hydraulic oil output from the main pump 5 enters the directional valve 7 through the main control valve 3, and finally enters the boom yaw cylinder 4 or the attachment 8 through the directional valve 7. The hydraulic oil output from the main pump 5 controls different movements of the boom yaw cylinder 4 or the attachment 8 through the first or second oil inlet, respectively.

[0055] In this technical solution, the right input section 11 and the left input section 12 are respectively the right-hand rotation section and the left-hand rotation section of the handle dial. The right-hand rotation section and the left-hand rotation section of the handle dial are electrically connected to the first pilot valve and the second pilot valve through the controller 1, respectively. Replacing the input section with a handle dial makes the operation more coordinated and easier to control.

[0056] In this technical solution, the boom sway cylinder 4 has a large chamber and a small chamber, which are respectively connected to the first oil outlet and the third oil outlet oil circuit.

[0057] In this technical solution, a rotary motor is connected to the attachment 8. The rotary motor is equipped with a left rotary liquid inlet and a right rotary liquid inlet. The left rotary liquid inlet and the right rotary liquid inlet are respectively connected to the oil circuits of the second oil outlet and the fourth oil outlet.

[0058] In this technical solution, the main pump 5 is connected to the main pump hydraulic oil tank 6.

[0059] An excavator includes the aforementioned hydraulic system for the excavator's attachments and boom sway. This allows the excavator to achieve an adjustable maximum attachment speed of 8 revolutions, meeting different customer speed requirements.

[0060] The technical means disclosed in this invention are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications are also considered within the scope of protection of this invention.

Claims

1. A hydraulic system for the swaying of the boom and arm of an excavator, characterized in that: Includes controller, proportional valve, main control valve, directional valve, main pump, boom yaw cylinder and attachments; The controller is connected to a right input section and a left input section; The proportional valve is electrically connected to the controller, and the proportional valve is also connected to the main control valve oil circuit. The main pump is connected to the main control valve oil circuit, the main control valve is connected to the reversing valve oil circuit, and the boom swing cylinder and the attachment are both connected to the reversing valve oil circuit. The controller controls the opening degree of the proportional valve, and the proportional valve controls the opening degree of the main control valve; The reversing valve includes a first oil outlet, a second oil outlet, a third oil outlet, and a fourth oil outlet arranged in parallel. The boom swing cylinder is connected to the first oil outlet and the third oil outlet in an oil circuit, and the attachment is connected to the second oil outlet and the fourth oil outlet in an oil circuit. The reversing valve further includes a first oil inlet and a second oil inlet, and the first oil outlet and the third oil outlet are simultaneously connected to the first oil inlet and the second oil inlet, respectively, or the second oil outlet and the fourth oil outlet are simultaneously connected to the first oil inlet and the second oil inlet, respectively. The boom sway cylinder has a large boom sway cylinder chamber and a small boom sway cylinder chamber, and the large boom sway cylinder chamber and the small boom sway cylinder chamber are respectively connected to the first oil outlet and the third oil outlet oil passage. The attachment is connected to a rotary motor, which is provided with a left rotary liquid inlet and a right rotary liquid inlet. The left rotary liquid inlet and the right rotary liquid inlet are respectively connected to the oil circuits of the second oil outlet and the fourth oil outlet.

2. The hydraulic system for boom and arm swaying of an excavator according to claim 1, characterized in that: The reversing valve includes a reversing signal input section; the reversing signal input section inputs a signal to control the first oil inlet to be connected with the first oil outlet and the second oil outlet, and also controls the second oil inlet to be connected with the third oil outlet and the fourth oil outlet.

3. The hydraulic system for boom and arm swaying of an excavator according to claim 1, characterized in that: The proportional valve includes a first pilot valve and a second pilot valve, which respectively control the opposite ends of the main valve core of the main control valve.

4. The hydraulic system for boom and arm swaying of an excavator according to claim 3, characterized in that: The main valve core of the main control valve controls the main control valve to connect with the oil circuit of the first oil inlet or the second oil inlet.

5. The hydraulic system for boom and arm swaying of an excavator according to claim 3, characterized in that: The right input section and the left input section are respectively the right-hand rotation section and the left-hand rotation section of the handle wheel. The right-hand rotation section and the left-hand rotation section of the handle wheel are electrically connected to the first pilot valve and the second pilot valve through the controller, respectively.

6. The hydraulic system for boom and arm swaying of an excavator according to claim 1, characterized in that: The main pump is connected to a main pump hydraulic oil tank.

7. An excavator, characterized in that, Includes the hydraulic system for boom and arm sway of an excavator as described in any one of claims 1 to 6.

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