An implement leveling system and an engineering vehicle

Abstract

The utility model provides a kind of implement leveling system and engineering vehicle, in the implement leveling system, in the case where boom rotates and lifts, the rodless cavity of first cylinder admits oil, first cylinder piston rod extends and pushes hydraulic oil, so that it enters the rodless cavity of second cylinder by communication valve group, to push the piston rod of second cylinder and extend, in the process of the piston rod of second cylinder and extend, implement is rotated by the piston rod of second cylinder to control to make implement keep horizontal state;In the case where boom rotates and falls, the rod cavity of first cylinder admits oil, first cylinder piston rod is retracted and pushes the hydraulic oil of rodless cavity, so that it enters the rod cavity of second cylinder by communication valve group, to push the piston rod of second cylinder and retract, in the process of the piston rod of second cylinder and retract, implement is rotated by the piston rod of second cylinder to control to make implement keep horizontal state. By doing so, avoid the problem of material leakage caused by implement inclination, improve unloading efficiency, simplify operation difficulty.

Description

Technical Field

[0001] This application relates to the field of engineering machinery technology, specifically to an attachment leveling system and an engineering vehicle. Background Technology

[0002] During operation, the boom controls the lifting of the attachments on a skid steer loader. If the boom rotation angle is large, the attachment's state changes significantly. For example, the attachment may initially be horizontal (i.e., the attachment opening remains horizontal), facilitating loading. However, as the boom rotation angle increases, the attachment opening's orientation changes. If the attachment lifting height doesn't change much, material leakage is minimal. But when the attachment lifting height changes significantly and the boom rotation angle is large, the attachment opening's tilt angle becomes too large (e.g., when the boom rotation angle approaches 90°), causing the material initially loaded inside the attachment to spill out, affecting transport efficiency. This also significantly increases the operator's difficulty. Summary of the Invention

[0003] In view of this, the present application provides an attachment leveling system that ensures the attachment remains level during boom lifting and lowering, preventing material leakage caused by attachment tilting. Additionally, the present application also provides an engineering vehicle incorporating the aforementioned attachment leveling system.

[0004] To achieve the above objectives, this application provides the following technical solution:

[0005] An attachment leveling system, comprising:

[0006] The first hydraulic cylinder is used to drive the boom to rotate around a first fixed point, the first fixed point being located at the first hinge end of the boom.

[0007] The second hydraulic cylinder is used to adjust the rotation of the attachment around a second fixed point, which is located at the second hinge end of the boom.

[0008] A connecting valve assembly connects the first hydraulic cylinder and the second hydraulic cylinder;

[0009] When the boom is rotating and lifting, oil enters the rodless chamber of the first cylinder to push the hydraulic oil in the rod chamber of the first cylinder to enter the rodless chamber of the second cylinder through the connecting valve group, so as to push the piston rod of the second cylinder to extend. During the extension of the piston rod of the second cylinder, the piston rod of the second cylinder controls the rotation of the attachment to keep the attachment in a horizontal state.

[0010] When the boom rotates and lowers, oil enters the rod chamber of the first cylinder to push the hydraulic oil in the rodless chamber of the first cylinder, causing it to enter the rod chamber of the second cylinder through the connecting valve assembly, thereby pushing the piston rod of the second cylinder to retract. During the retraction of the piston rod of the second cylinder, the piston rod of the second cylinder controls the rotation of the attachment to keep the attachment in a horizontal state.

[0011] Optionally, in the above-mentioned attachment leveling system, the connecting valve group includes a flow regulating valve group, which is used to regulate the flow rate of hydraulic oil from the first cylinder into the second cylinder.

[0012] Optionally, in the above-mentioned attachment leveling system, the connecting valve group further includes a first directional valve;

[0013] When the first directional valve is in its first working position, the flow regulating valve group and the rod chamber of the first cylinder are connected through the first directional valve.

[0014] When the first directional valve is in its second operating position, the flow regulating valve assembly and the rodless chamber of the first cylinder are connected through the first directional valve.

[0015] Optionally, in the above-mentioned attachment leveling system, the connecting valve group further includes a second directional valve;

[0016] When the second directional valve is in its first working position, both the flow regulating valve group and the rodless chamber of the second cylinder are connected to the second directional valve, so that hydraulic oil enters the rodless chamber of the second cylinder from the flow regulating valve group through the second directional valve.

[0017] When the second directional valve is in its second working position, both the flow regulating valve group and the rod chamber of the second cylinder are connected to the second directional valve, so that the hydraulic oil enters the rod chamber of the second cylinder from the flow regulating valve group through the second directional valve.

[0018] When the second directional valve is in its third operating position, the second directional valve is in the closed state.

[0019] Optionally, in the above-mentioned attachment leveling system, the connecting valve group includes a first regulating valve group and a second regulating valve group, wherein,

[0020] The rod chamber of the first cylinder and the rodless chamber of the second cylinder are both connected to the first regulating valve group, so that the hydraulic oil in the rod chamber of the first cylinder enters the rodless chamber of the second cylinder through the first regulating valve group at a first preset ratio.

[0021] The rodless chamber of the first cylinder and the rod chamber of the second cylinder are both connected to the second regulating valve group, so that the hydraulic oil in the rodless chamber of the first cylinder enters the rod chamber of the second cylinder through the second regulating valve group at a second preset ratio.

[0022] Optionally, in the above-mentioned attachment leveling system, the flow regulating valve group includes a first damping orifice and a second damping orifice for diverting flow. The first damping orifice is connected to the hydraulic oil tank, and the second damping orifice is connected to the second oil cylinder. By adjusting the opening of the second damping orifice, the flow rate of hydraulic oil entering the second oil cylinder from the first oil cylinder can be adjusted.

[0023] Optionally, in the above-mentioned attachment leveling system, the flow regulating valve group further includes a flow divider valve connected to the first damping orifice and the second damping orifice.

[0024] Optionally, in the above-mentioned attachment leveling system, the flow regulating valve group further includes a balance valve connected to the flow divider valve, the balance valve being used to balance the pressure of the hydraulic oil in the second cylinder.

[0025] Optionally, the above-mentioned attachment leveling system further includes a cylinder control valve group connecting the hydraulic oil tank, the second cylinder, and the first cylinder. The cylinder control valve group includes a third directional valve.

[0026] When the third directional valve is in its first working position, the hydraulic oil tank is connected to the first directional valve in its first working position, so that the hydraulic oil in the hydraulic oil tank enters the rodless chamber of the first cylinder.

[0027] When the third directional valve is in its second working position, the hydraulic oil tank is connected to the second working position of the first directional valve, so that the hydraulic oil in the hydraulic oil tank enters the rod chamber of the first cylinder.

[0028] An engineering vehicle comprising the attachment leveling system described in any of the preceding claims.

[0029] This application provides an attachment leveling system. A connecting valve assembly connects a first cylinder and a second cylinder. When the boom is rotating and lifting, oil enters the rodless chamber of the first cylinder, pushing the hydraulic oil in the rod-side chamber of the first cylinder into the rodless chamber of the second cylinder through the connecting valve assembly. This pushes the piston rod of the second cylinder to extend, controlling the attachment's rotation to maintain a horizontal position. When the boom is rotating and lowering, oil enters the rod-side chamber of the first cylinder, pushing the hydraulic oil in the rodless chamber of the first cylinder into the rod-side chamber of the second cylinder through the connecting valve assembly. This pushes the piston rod of the second cylinder to retract, controlling the attachment's rotation to maintain a horizontal position. In this way, the attachment can be adjusted to maintain a horizontal position during both lifting and lowering, avoiding material leakage caused by attachment tilting, improving unloading efficiency, and simplifying operation. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0031] Figure 1 This is a schematic diagram illustrating the different states of the boom at different heights during lifting in existing technology;

[0032] Figure 2 This is a schematic diagram illustrating the different states of the boom at different heights during descent in existing technology;

[0033] Figure 3 This is a schematic diagram showing the state of the boom at different heights during descent, as provided in the embodiments of this application.

[0034] Figure 4 This is a diagram of the leveling system according to Embodiment 1 of this application;

[0035] Figure 5 This is a diagram of the leveling system in Embodiment 2 of this application.

[0036] exist Figures 1-5 middle:

[0037] 1. First hydraulic cylinder; 2. Boom; 3. Second hydraulic cylinder; 4. Attachment; 5. Connecting valve assembly; 6. Hydraulic cylinder control valve assembly;

[0038] 51. Flow control valve assembly; 52. First directional valve; 53. Second directional valve; 54. First regulating valve assembly; 55. Second regulating valve assembly;

[0039] 511. First damping orifice; 512. Second damping orifice; 513. Diverter valve; 514. Balance valve;

[0040] 515. Third damping orifice; 516. Fourth damping orifice;

[0041] 61. Third directional valve; 62. Fourth directional valve. Detailed Implementation

[0042] This application provides an attachment leveling system that ensures the attachment remains level during boom lifting and lowering, preventing material leakage caused by attachment tilting. Additionally, this application also provides an engineering vehicle incorporating the aforementioned attachment leveling system.

[0043] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0044] like Figures 1-2 As shown, in the prior art, the attachment 4 is not leveled during the lifting and lowering of the boom 2, making it difficult to tilt the material. It should be noted that in addition to transferring materials, the vehicle can also allow personnel to stand on the attachment 4 to observe the surrounding environment or target objects, or to transport personnel. Therefore, the attachment 4 should be kept horizontal during the lifting and lowering process.

[0045] like Figures 3-5 As shown in the embodiment of this application, an attachment leveling system includes a first hydraulic cylinder 1, a second hydraulic cylinder 3, and a connecting valve group 5. The first hydraulic cylinder 1 is used to drive the boom 2 to rotate around a first fixed point, which is located at the first hinge end of the boom 2. The second hydraulic cylinder 3 is used to adjust the attachment 4 to rotate around a second fixed point, which is located at the second hinge end of the boom 2. The connecting valve group 5 connects the first hydraulic cylinder 1 and the second hydraulic cylinder 3.

[0046] When the boom 2 rotates and lifts, oil enters the rodless chamber of the first cylinder 1 to push the hydraulic oil in the rod chamber of the first cylinder 1, causing it to enter the rodless chamber of the second cylinder 3 through the connecting valve group 5, thereby pushing the piston rod of the second cylinder 3 to extend. During the extension of the piston rod of the second cylinder 3, the piston rod of the second cylinder 3 controls the rotation of the attachment 4 to keep the attachment 4 in a horizontal state. When the boom 2 rotates and lowers, oil enters the rod chamber of the first cylinder 1 to push the hydraulic oil in the rodless chamber of the first cylinder 1, causing it to enter the rod chamber of the second cylinder 3 through the connecting valve group 5, thereby pushing the piston rod of the second cylinder 3 to retract. During the retraction of the piston rod of the second cylinder 3, the piston rod of the second cylinder 3 controls the rotation of the attachment 4 to keep the attachment 4 in a horizontal state. Therefore, during the lifting process of boom 2, as the piston rod of the first cylinder 1 extends, the piston rod of the second cylinder 3 also extends, and the hydraulic oil pushing the piston rod of the second cylinder 3 to extend comes from the first cylinder 1. Correspondingly, during the lowering process of boom 2, as the piston rod of the first cylinder 1 retracts, the piston rod of the second cylinder 3 also retracts, and the hydraulic oil pushing the piston rod of the second cylinder 3 to retract comes from the first cylinder 1. Thus, it can be seen that during the process of driving boom 2, the first cylinder 1 can automatically level the attachment 4. That is, the operator can achieve the leveling of attachment 4 by controlling the lifting and lowering process of boom 2 driven by the first cylinder 1. This not only avoids the material leakage problem caused by the tilting of attachment 4, but also improves the unloading efficiency and simplifies the operation difficulty for the operator.

[0047] It should be noted that attachment 4 usually refers to equipment or tools attached to machinery to extend its function, such as the grab bucket of a crane or the bucket of an excavator.

[0048] It should also be noted that, depending on the function of the connecting valve assembly 5, it can be as described in Embodiment 1 or Embodiment 2 below.

[0049] Example 1: The connecting valve assembly 5 includes a flow regulating valve assembly 51, which is used to regulate the flow rate of hydraulic oil from the first cylinder 1 into the second cylinder 3. This ensures that the hydraulic oil in the first cylinder 1 enters the second cylinder 3 in a certain proportion, so that when the first cylinder 1 drives the boom 2 to rise or fall, the piston rod of the second cylinder 3 extends or retracts accordingly, and the extension or retraction size keeps the attachment 4 in a horizontal state.

[0050] In some alternative embodiments, besides using the flow regulating valve assembly 51, other methods can be used, such as using an angle sensor on the attachment 4 and a controller communicatively connected to the angle sensor. The angle sensor detects whether the attachment 4 is in a horizontal state and transmits the status signal of the attachment 4 to the controller, which controls the immediate opening and closing of the connecting valve assembly 5. When the attachment 4 is in a horizontal state relative to the horizontal plane, the connecting valve assembly 5 is disconnected; when the attachment 4 is tilted relative to the horizontal plane, the connecting valve assembly 5 connects the first cylinder 1 and the second cylinder 3. It should be noted that the connecting valve assembly 5 at this time includes at least a valve that is always in an actuated state. This valve has at least three working positions: a first working position that connects the rod chamber of the first cylinder 1 and the rodless chamber of the second cylinder 3; a second working position that connects the rodless chamber of the first cylinder 1 and the rod chamber of the second cylinder 3; and a third working position that does not connect the first cylinder 1 and the second cylinder 3.

[0051] like Figure 4 As shown, the connecting valve assembly 5 also includes a first directional valve 52. In the first operating position of the first directional valve 52, the flow regulating valve assembly 51 and the rod chamber of the first cylinder 1 are connected through the first directional valve 52. In the second operating position of the first directional valve 52, the flow regulating valve assembly 51 and the rodless chamber of the first cylinder 1 are connected through the first directional valve 52. It should be noted that in the first operating position of the first directional valve 52, the hydraulic oil in the rod chamber of the first cylinder 1 enters the flow regulating valve assembly 51 through the first directional valve 52 to regulate the amount of hydraulic oil entering the rodless chamber of the second cylinder 3. In the second operating position of the first directional valve 52, the hydraulic oil in the rodless chamber of the first cylinder 1 enters the flow regulating valve assembly 51 through the first directional valve 52 to regulate the amount of hydraulic oil entering the rod chamber of the second cylinder 3. The inclusion of the first directional valve 52 simplifies the system's piping design and facilitates system maintenance and control.

[0052] In some other alternative embodiments, in addition to using the first directional valve 52, a multi-pipeline configuration can be used to replace the function of the first directional valve 52.

[0053] In some optional embodiments, the connecting valve assembly 5 further includes a second directional valve 53; in the first working position of the second directional valve 53, the rodless chambers of both the flow regulating valve assembly 51 and the second cylinder 3 are connected to the second directional valve 53, so that hydraulic oil enters the rodless chamber of the second cylinder 3 from the flow regulating valve assembly 51 through the second directional valve 53; in the second working position of the second directional valve 53, the rod chambers of both the flow regulating valve assembly 51 and the second cylinder 3 are connected to the second directional valve 53, so that hydraulic oil enters the rod chamber of the second cylinder 3 from the flow regulating valve assembly 51 through the second directional valve 53; in the third working position of the second directional valve 53, the second directional valve 53 is in a closed state. It should be noted that when the second directional valve 53 is in the third working position, during the lifting and lowering of the boom 2, the hydraulic oil in the first cylinder 1 flows back to the hydraulic oil tank (i.e., it does not flow to the second cylinder 3). At this time, the system does not level the attachment 4. It should be pointed out that the attachment 4 can be in an unleveled working state when not loaded, in which case the hydraulic system responds faster. In summary, whether the attachment 4 is leveled can be adjusted according to the actual situation, allowing the attachment 4 to have more working states. For example, when the boom 2 rises, one stroke of the attachment 4 can be in a leveled state, and the other stroke can be in an unleveled state. This is just an example; the specific working state of the attachment 4 can be set according to actual needs.

[0054] Example 2: Figure 5 As shown, the connecting valve group 5 includes a first regulating valve group 54 and a second regulating valve group 55. The rod chamber of the first cylinder 1 and the rodless chamber of the second cylinder 3 are both connected to the first regulating valve group 54, so that the hydraulic oil in the rod chamber of the first cylinder 1 enters the rodless chamber of the second cylinder 3 through the first regulating valve group 54 at a first preset ratio; the rodless chamber of the first cylinder 1 and the rod chamber of the second cylinder 3 are both connected to the second regulating valve group 55, so that the hydraulic oil in the rodless chamber of the first cylinder 1 enters the rod chamber of the second cylinder 3 through the second regulating valve group 55 at a second preset ratio. In this way, the attachment 4 is always kept horizontal, which not only avoids material leakage caused by the attachment 4 tilting, but also improves unloading efficiency and simplifies the operator's work.

[0055] It should be noted that the first regulating valve group 54 and the second regulating valve group 55 have basically the same structure and working principle, and both the first regulating valve group 54 and the second regulating valve group 55 include a flow regulating valve group 51. Please refer to the following description for the flow regulating valve group 51.

[0056] The connecting valve group 5 can be either of Embodiment 1 and Embodiment 2, and it also has the following structure and function.

[0057] In some optional embodiments, the flow regulating valve assembly 51 includes a first damping orifice 511 and a second damping orifice 512 for diverting flow. The first damping orifice 511 is connected to the hydraulic oil tank, and the second damping orifice 512 is connected to the second cylinder 3. The flow rate of hydraulic oil entering the second cylinder 3 from the first cylinder 1 can be adjusted by adjusting the opening of the second damping orifice 512. It should be noted that the second damping orifice 512 is an adjustable damping orifice. By setting the first damping orifice 511 and the second damping orifice 512, the flow rate of hydraulic oil flowing from the first cylinder 1 into the second cylinder 3 is controlled, so that the attachment 4 is in a horizontal state.

[0058] It should be noted that the opening of the second damping orifice 512 can be adjusted manually or electrically. The opening size can vary depending on the performance of the drive cylinder of different engineering vehicles. The opening can be maintained after balancing for the same model of vehicle for application.

[0059] The flow control valve assembly 51 also includes a flow divider valve 513 connected to the first damping orifice 511 and the second damping orifice 512. The first damping orifice 511 and the second damping orifice 512 generate pressure drops and flow distribution when hydraulic oil flows through them, which helps the flow divider valve 513 to distribute flow more effectively and smoothly. This enables more complex control strategies, such as proportional control and pressure compensation.

[0060] In some optional embodiments, the flow control valve assembly 51 further includes a balance valve 514 connected to the diverter valve 513. The balance valve 514 is used to balance the pressure of the hydraulic oil in the second cylinder 3. During the raising or lowering of the boom 2, a portion of the hydraulic oil in the first cylinder 1 enters the second cylinder 3, and the hydraulic oil in the second cylinder 3 flows back to the hydraulic oil tank after passing through the balance valve 514. The balance valve 514 facilitates the equalization of the pressure of the hydraulic oil flowing back to the hydraulic oil tank.

[0061] It should be noted that when the first cylinder 1 is not in operation, the balance valve 514 is in the first working position (left position), and the balance valve 514 is not working at this time. When the first cylinder 1 is in operation, that is, when the attachment 4 is leveled and the second cylinder 3 is in a non-limit position, most of the hydraulic oil flowing through the second damping hole 512 enters the second cylinder 3 to level the attachment 4, and a small portion of the hydraulic oil enters the balance valve 514 and pushes the balance valve 514 to the second working position (middle position). This small portion of the hydraulic oil flows back to the hydraulic oil tank after passing through the third damping hole 515 and the fourth damping hole 516. When the first cylinder 1 is in operation, that is, when the attachment 4 is leveled and the second cylinder 3 is in a limit position, the hydraulic oil at the second damping hole 512 cannot enter the second cylinder 3. The hydraulic oil enters the balance valve 514 and pushes the balance valve 514 to the third working position (right position), and the hydraulic oil flows back to the hydraulic oil tank.

[0062] In some optional embodiments, the attachment leveling system further includes a cylinder control valve assembly 6 connecting the hydraulic oil tank, the second cylinder 3, and the first cylinder 1. The cylinder control valve assembly 6 includes a third directional valve 61. When the third directional valve 61 is in a first operating position, the hydraulic oil tank is connected to the first directional valve 52 in the first operating position, allowing hydraulic oil in the hydraulic oil tank to enter the rodless chamber of the first cylinder 1. When the third directional valve 61 is in a second operating position, the hydraulic oil tank is connected to the first directional valve 52 in the second operating position, allowing hydraulic oil in the hydraulic oil tank to enter the rod chamber of the first cylinder 1. The third directional valve 61 simplifies the system piping, facilitates maintenance, and increases the system's integration.

[0063] It should be noted that the cylinder control valve group 6 also includes a fourth directional valve 62 and multiple relief valves. The fourth directional valve 62 is used to control the active extension and retraction of the second cylinder 3. That is, when the boom 2 is stationary, the fourth directional valve 62 is used to adjust the extension and retraction of the attachment 4. The multiple relief valves, some of which act on the first cylinder 1 and others on the second cylinder 3, are all used for overload protection of the cylinder (first cylinder 1 or second cylinder 3).

[0064] The working process of Example 1 is as follows.

[0065] The boom 2 is raised, and the attachment 4 is leveled: the third directional valve 61 is in the first working position, the fourth directional valve 62 is in the neutral position, the first directional valve 52 is in the first working position, and the second directional valve 53 is in the first working position. The pump pumps hydraulic oil into the cylinder control valve group 6 through the IN port, and out through the 1B port of the third directional valve 61 in the first working position. The oil then enters the rodless chamber of the first cylinder 1 through the first directional valve 52, and the piston rod of the first cylinder 1 extends. The hydraulic oil returning from the rod chamber of the first cylinder 1 enters port A of the flow regulating valve group 51 via the first directional valve 52. It then flows through the first damping orifice 511, the second damping orifice 512, and the flow divider valve 513, and is proportionally divided (the proportional amount is adjusted by adjusting the second damping orifice 512). A portion of the hydraulic oil flows out through port D of the flow regulating valve group 51, passes through the first working position of the second directional valve 53, and reaches the rodless chamber of the second cylinder 3, pushing the piston rod of the second cylinder 3 to extend and keeping the attachment 4 in a horizontal position. Another portion of the hydraulic oil flows to port B of the flow regulating valve group 51, enters port 1A of the cylinder control valve group 6 via the first directional valve 52, and flows out through the first working position of the third directional valve 61 of the cylinder control valve group 6, passing through port OUT to the hydraulic oil tank. The rodless chamber of the second cylinder 3 is connected to port 2A of the cylinder control valve group 6, and the rod chamber is connected to port 2B of the cylinder control valve group 6. The oil circuit is in a closed state. The hydraulic oil returning from the rod chamber of the second cylinder 3 enters port C of the flow regulating valve group 51 through the first working position of the second directional valve 53, flows to port B of the flow regulating valve group 51 through the neutral oil circuit of the balance valve 514, enters through port 1A of the cylinder control valve group 6, flows out through the first working position of the third directional valve 61 of the cylinder control valve group 6, and flows to the hydraulic oil tank through the OUT port.

[0066] Boom 2 descends, attachment 4 levels: Third directional valve 61 is in the second working position, fourth directional valve 62 is in the neutral position, first directional valve 52 is in the second working position, and second directional valve 53 is in the second working position. The pump pumps hydraulic oil into the cylinder control valve group 6 through the IN port, flows out through the third directional valve 61 in the second working position through port 1A, and enters the rod chamber of the first cylinder 1 through the first directional valve 52 in the second working position, causing the piston rod of the first cylinder 1 to retract. The hydraulic oil returning from the rodless chamber of the first cylinder 1 enters port A of the flow regulating valve group 51 via the first directional valve 52. It then flows through the first damping orifice 511, the second damping orifice 512, and the flow divider valve 513, where it is proportionally divided (the proportional amount is adjusted by adjusting the second damping orifice 512). A portion flows out through port D of the first directional valve 52, passes through the second working position of the second directional valve 53, and reaches the rod chamber of the second cylinder 3, pushing the piston rod of the second cylinder 3 to retract, thus keeping the attachment 4 in a horizontal position. Another portion of the hydraulic oil flows to port B of the flow regulating valve group 51, enters port 1B of the cylinder control valve group 6 via the first directional valve 52, and flows out through the second working position of the third directional valve 61 of the cylinder control valve group 6, passing through port OUT to the hydraulic oil tank. The rodless chamber of the second cylinder 3 is connected to port 2A of the cylinder control valve group 6, and the rod chamber is connected to port 2B of the cylinder control valve group 6. The oil circuit is closed. The hydraulic oil returning from the rodless chamber of the second cylinder 3 enters port C of the flow regulating valve group 51 through the second working position of the second directional valve 53, flows to port B of the flow regulating valve group 51 through the neutral oil circuit of the balance valve 514, enters from port 1B of the cylinder control valve group 6 after passing through the first directional valve 52, and flows out through port OUT to the hydraulic oil tank through the second working position of the third directional valve 61 of the cylinder control valve group 6.

[0067] When boom 2 is raised and attachment 4 is not leveled: the third directional valve 61 is in the first working position, the fourth directional valve 62 is in the neutral position, the first directional valve 52 is in the first working position, and the second directional valve 53 is in the third working position. The pump draws hydraulic oil into the cylinder control valve group 6 through the IN port, through the first working position of the third directional valve 61 to the 1B port, and through the first directional valve 52 into the rodless chamber of the first cylinder 1, extending the piston rod of the first cylinder 1. The hydraulic oil returning from the rod chamber of the first cylinder 1 enters the A port of the flow regulating valve group 51 through the first directional valve 52. Since the C and D ports of the flow regulating valve group 51 are closed, all hydraulic oil flows to the B port of the flow regulating valve group 51, through the first directional valve 52 into the 1A port of the cylinder control valve group 6, and through the first working position of the third directional valve 61 of the cylinder control valve group 6, flows out through the OUT port to the hydraulic oil tank. The rodless chamber of the second cylinder 3 is connected to port 2A of the cylinder control valve group 6, and the rod chamber is connected to port 2B of the cylinder control valve group 6. The working device cylinder does not move.

[0068] Boom 2 descends, attachment 4 is not leveled: Third directional valve 61 is in the second working position, fourth directional valve 62 is in the neutral position, first directional valve 52 is in the second working position, and second directional valve 53 is in the third working position. The pump pumps hydraulic oil into the cylinder control valve group 6 through the IN port, flows out through the second working position of the third directional valve 61 through port 1A, and enters the rod chamber of the first cylinder 1 through the first directional valve 52, causing the piston rod of the first cylinder 1 to retract. The hydraulic oil returning from the rodless chamber of the first cylinder 1 enters the A port of the flow regulating valve group 51 through the first directional valve 52. Since the C and D ports of the flow regulating valve group 51 are closed, all hydraulic oil flows to the B port of the flow regulating valve group 51, enters the 1B port of the cylinder control valve group 6 through the first directional valve 52, flows out through the second working position of the third directional valve 61 of the cylinder control valve group 6, and returns to the hydraulic oil tank through the OUT port. The rodless chamber of the second cylinder 3 is connected to port 2A of the cylinder control valve group 6, and the rod chamber is connected to port 2B of the cylinder control valve group 6. The working device cylinder does not move.

[0069] The working process of Example 2 is as follows.

[0070] The boom 2 is raised, and the attachment 4 is leveled: the third directional valve 61 is in the first working position, and the fourth directional valve 62 is in the neutral position. The pump pumps hydraulic oil into the cylinder control valve group 6 through the IN port, and through the first working position of the third directional valve 61, it flows out through port 1B and into port B of the first regulating valve group 54. After passing through the check valve, it flows out from port A of the first regulating valve group 54 and into the rodless chamber of the first cylinder 1, where the piston rod of the first cylinder 1 extends. The hydraulic oil returning from the rod chamber of the first cylinder 1 enters port A of the second regulating valve group 55, and flows through the first damping hole 511, the second damping hole 512, and the flow divider valve 513, and is proportionally divided (the proportional amount is adjusted by adjusting the second damping hole 512). Part of the hydraulic oil flows out through port D of the second regulating valve group 55 to the rodless chamber of the second cylinder 3, pushing the piston rod of the second cylinder 3 to extend, so that the attachment 4 is kept in a horizontal position; part of the hydraulic oil flows to port B of the second regulating valve group 55, enters through port 1A of the cylinder control valve group 6, flows out through the first working position of the third directional valve 61 of the cylinder control valve group 6, and flows to the hydraulic oil tank through port OUT. The rodless chamber of the second cylinder 3 is connected to port 2A of the cylinder control valve group 6, and the rod chamber is connected to port 2B of the cylinder control valve group 6. The oil circuit is in a closed state. The hydraulic oil returning from the rod chamber of the second cylinder 3 enters port C of the second regulating valve group 55, flows through the neutral oil circuit of the balance valve 514 to port B of the second regulating valve group 55, enters through port 1A of the cylinder control valve group 6, flows out through the first working position of the third directional valve 61 of the cylinder control valve group 6, and flows to the hydraulic oil tank through port OUT.

[0071] Boom 2 descends, attachment 4 levels: third directional valve 61 is in the second working position, fourth directional valve 62 is in the neutral position. The pump pumps hydraulic oil into the cylinder control valve group 6 through the IN port, flows out through port 1A through the second working position of the third directional valve 61 and enters port B of the second regulating valve group 55. It then flows out through port A of the second regulating valve group 55 through the check valve and enters the rod chamber of the first cylinder 1, causing the piston rod of the first cylinder 1 to retract. Hydraulic oil returning from the rodless chamber of the first cylinder 1 enters port A of the first regulating valve group 54, and flows through the first damping orifice 511, the second damping orifice 512, and the diverter valve 513, and is proportionally divided (the proportional amount is adjusted by adjusting the second damping orifice 512). Part of the hydraulic oil flows out through port D of the first regulating valve group 54 to the rod chamber of the second cylinder 3, pushing the piston rod of the second cylinder 3 to retract, so that the attachment 4 maintains a horizontal posture; part of the hydraulic oil flows to port B of the first regulating valve group 54, enters through port 1B of the cylinder control valve group 6, flows out through the second working position of the third directional valve 61 of the cylinder control valve group 6, and flows to the hydraulic oil tank through port OUT. The rodless chamber of the second cylinder 3 is connected to port 2A of the cylinder control valve group 6, and the rod chamber is connected to port 2B of the cylinder control valve group 6. The oil circuit is in a closed state. The hydraulic oil returning from the rodless chamber of the second cylinder 3 enters port C of the first regulating valve group 54, flows through the neutral oil circuit of the balance valve 514 to port B of the first regulating valve group 54, enters through port B of the cylinder control valve group 6, flows out through the second working position of the third directional valve 61 of the cylinder control valve group 6, and flows to the hydraulic oil tank through port OUT.

[0072] In addition, this application also provides an engineering vehicle that includes the aforementioned attachment leveling system. The beneficial effects of the attachment leveling system on the engineering vehicle are described above, and will not be repeated here.

[0073] The above specific embodiments describe the basic principles of this application. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0074] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0075] It should also be noted that in the apparatus, equipment, and methods of this application, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered as equivalent solutions of this application.

[0076] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0077] It should be understood that the qualifiers “first,” “second,” “third,” “fourth,” “fifth,” and “sixth” used in the description of the embodiments of this application are only used to more clearly illustrate the technical solutions and are not intended to limit the scope of protection of this application.

[0078] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A tool leveling system, characterized by, The utility model relates to a kind of hydraulic control systems of mobile crane, including: First oil cylinder (1) for driving swing around first fixed point, the first fixed point is located in the first articulated end of the swing arm (2); Second oil cylinder (3) for adjusting tool (4) swing around second fixed point, the second fixed point is located in the second articulated end of the swing arm (2); Communication valve group (5) connects the first oil cylinder (1) and the second oil cylinder (3); Wherein, in the case of the swing arm (2) rotation lifting, the rodless cavity of the first oil cylinder (1) oil inlet, to push the hydraulic oil in the rod cavity of the first oil cylinder (1), so that it enters the rodless cavity of the second oil cylinder (3) by the communication valve group (5), to push the piston rod of the second oil cylinder (3) to extend, in the piston rod of the second oil cylinder (3) extension process by the piston rod of the second oil cylinder (3) control tool (4) rotation to make tool (4) keep horizontal state; In the case of the swing arm (2) rotation descending, the rod cavity of the first oil cylinder (1) oil inlet, to push the hydraulic oil in the rodless cavity of the first oil cylinder (1), so that it enters the rod cavity of the second oil cylinder (3) by the communication valve group (5), to push the piston rod of the second oil cylinder (3) to retract, in the piston rod of the second oil cylinder (3) retraction process by the piston rod of the second oil cylinder (3) control tool (4) rotation to make tool (4) keep horizontal state; The communication valve group (5) includes flow regulating valve group (51), and the flow regulating valve group (51) is used to adjust the flow of the hydraulic oil of the first oil cylinder (1) into the second oil cylinder (3); The communication valve group (5) further includes first reversing valve (52); When the first working position of the first reversing valve (52), the flow regulating valve group (51) and the rod cavity of the first oil cylinder (1) are connected by the first reversing valve (52); When the second working position of the first reversing valve (52), the flow regulating valve group (51) and the rodless cavity of the first oil cylinder (1) are connected by the first reversing valve (52).

2. The implement leveling system of claim 1, wherein, The communication valve group (5) further includes second reversing valve (53); When the first working position of the second reversing valve (53), the flow regulating valve group (51) and the rodless cavity of the second oil cylinder (3) are connected by the second reversing valve (53), so that the hydraulic oil from the flow regulating valve group (51) enters the rodless cavity of the second oil cylinder (3) by the second reversing valve (53); When the second working position of the second reversing valve (53), the flow regulating valve group (51) and the rod cavity of the second oil cylinder (3) are connected by the second reversing valve (53), so that the hydraulic oil from the flow regulating valve group (51) enters the rod cavity of the second oil cylinder (3) by the second reversing valve (53); When the third working position of the second reversing valve (53), the second reversing valve (53) is in the closed state.

3. The implement leveling system of claim 1, wherein, The communication valve group (5) includes first regulating valve group (54) and second regulating valve group (55), wherein, The rod cavity of the first oil cylinder (1) and the rodless cavity of the second oil cylinder (3) are communicated with the first adjusting valve group (54), so that the hydraulic oil in the rod cavity of the first oil cylinder (1) enters the rodless cavity of the second oil cylinder (3) through the first adjusting valve group (54) at a first preset ratio; The rodless cavity of the first oil cylinder (1) and the rod cavity of the second oil cylinder (3) are communicated with the second adjusting valve group (55), so that the hydraulic oil in the rodless cavity of the first oil cylinder (1) enters the rod cavity of the second oil cylinder (3) through the second adjusting valve group (55) at a second preset ratio.

4. The implement leveling system of claim 1, wherein, The flow adjusting valve group (51) comprises a first damping hole (511) and a second damping hole (512) for flow splitting, the first damping hole (511) is communicated with the hydraulic oil tank, and the second damping hole (512) is communicated with the second oil cylinder (3), and the flow of the hydraulic oil entering the second oil cylinder (3) from the first oil cylinder (1) can be adjusted by adjusting the opening of the second damping hole (512).

5. The implement leveling system of claim 4, wherein, The flow adjusting valve group (51) further comprises a flow splitting valve (513) connected with the first damping hole (511) and the second damping hole (512).

6. The implement leveling system of claim 5, wherein, The flow adjusting valve group (51) further comprises a balance valve (514) connected with the flow splitting valve (513), and the balance valve (514) is used for balancing the pressure of the hydraulic oil of the second oil cylinder (3).

7. The implement leveling system of claim 1, wherein, Further comprising an oil cylinder control valve group (6) connected with the hydraulic oil tank, the second oil cylinder (3) and the first oil cylinder (1), the oil cylinder control valve group (6) comprises a third reversing valve (61), wherein, When the first working position of the third reversing valve (61), the hydraulic oil tank is communicated with the first reversing valve (52) in the first working position, so that the hydraulic oil in the hydraulic oil tank enters the rodless cavity of the first oil cylinder (1); When the second working position of the third reversing valve (61), the hydraulic oil tank is communicated with the first reversing valve (52) in the second working position, so that the hydraulic oil in the hydraulic oil tank enters the rod cavity of the first oil cylinder (1).

8. An engineering vehicle characterized by, The implement leveling system comprises the implement leveling system according to any one of claims 1-7.

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