Control system for hydraulic pump of excavator

Abstract

The present application relates to the technical field of hydraulic pump, in particular to a control system of excavator hydraulic pump, comprising: an oil tank for storing hydraulic oil; a hydraulic pump, the input end is connected to the oil tank, the hydraulic pump is provided with two independent output pipelines, the output ends of the first output pipeline and the second output pipeline are connected to the A interface and the B interface of the control valve through the throttle valve respectively, and the throttle valve is used for controlling the flow of the first output pipeline or the second output pipeline to the control valve. The present application provides power for the hydraulic drive rod through two liquid supply pipelines, and the first oil cavity and the second oil cavity of the hydraulic drive rod are communicated with the control valve through two branches, the liquid return pipeline of the system has four input ends, the control valve can change different liquid supply and return channels by changing the position of the valve core, the flexibility is higher, the adjustable one-way valve is arranged in one of the liquid return branches, the conduction state can be controlled according to the pressure of liquid supply or liquid return, so that more requirements and control schemes can be realized.

Description

Technical Field

[0001] This invention relates to the field of hydraulic pump technology, and more specifically to a control system for an excavator hydraulic pump. Background Technology

[0002] This system mainly includes a hydraulic oil tank, main pump, multi-way valve, various pipelines, and components such as cylinders and motors that perform various actions. Its working principle is that, using hydraulic oil as the working medium, the hydraulic pump converts the mechanical energy of the engine into hydraulic energy and transmits it. Then, through hydraulic cylinders and hydraulic motors, the hydraulic energy is converted back into mechanical energy, thereby realizing the various actions of the excavator.

[0003] A hydraulic pump compresses fluid by changing the volume of its pump chamber through movement, thus giving the fluid pressure energy. In an excavator's hydraulic system, the main function of the hydraulic pump is to convert the engine's mechanical energy into hydraulic energy, providing power to the entire system.

[0004] Excavators operate in diverse environments, especially the drive cylinder that moves the bucket. Depending on the working conditions, sometimes it needs to provide greater thrust to offer greater digging capacity, while at other times it needs to limit its maximum thrust to prevent uncontrollable damage during digging. Alternatively, it may be necessary to allow the bucket to sway freely within a certain range. For example, during transportation, if the bucket is at a certain angle, swaying can cause the bucket to collide with the load-bearing plate. Therefore, the bucket drive cylinder needs more flexible control. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a control system for an excavator hydraulic pump, comprising:

[0006] Oil tank, used to store hydraulic oil;

[0007] The hydraulic pump has its input end connected to the oil tank. The hydraulic pump has two independent output lines. The output ends of the first output line and the second output line are connected to the A port and B port of the control valve respectively through a throttle valve. The throttle valve is used to control the flow rate from the first output line or the second output line to the control valve.

[0008] The return line includes four input terminals and one output terminal. The first and second input terminals are connected to the first and second output lines through an overflow valve. The third input terminal is connected to the C port of the control valve, the fourth input terminal is connected to the D port of the control valve, and the output terminal of the return line is connected to the oil tank.

[0009] The hydraulic drive rod includes a first oil chamber, a second oil chamber, and a hydraulic rod. The first oil chamber is connected to the E port and F port of the control valve through a first pipeline and a second pipeline, respectively. The second oil chamber is connected to the G port and H port of the control valve through a third pipeline and a fourth pipeline, respectively.

[0010] A branch circuit is provided between the C interface and the return pipeline. An adjustable check valve is provided on the branch circuit. The control valve includes a valve body and a valve core. The valve core is configured to control the connection status of each interface on the valve body by changing its position.

[0011] Preferably, the valve core includes a first position state, which includes an extended position and a shortened position. When the valve core is in the extended position, the A and E ports of the valve body are connected, the G and C ports of the valve body are connected, the first output pipeline pumps fluid into the first oil chamber, and the second oil chamber returns fluid through the return pipeline. When the valve core is in the shortened position, the A and G ports of the valve body are connected, the E and C ports of the valve body are connected, the first output pipeline pumps fluid into the second oil chamber, and the first oil chamber returns fluid through the return pipeline.

[0012] Preferably, the valve core includes a second position state, which includes an extended position and a shortened position. When the valve core is in the extended position, the A and E ports of the valve body are connected, the B and F ports are connected, the G and C ports are connected, and the H and D ports are connected. The first and second output pipes pump fluid into the first oil chamber, and the second oil chamber returns fluid through the return pipe and the branch circuit. When the valve core is in the shortened position, the A and G ports of the valve body are connected, the B and H ports are connected, the E and C ports are connected, and the F and D ports are connected. The first and second output pipes pump fluid into the second oil chamber, and the first oil chamber returns fluid through the return pipe and the branch circuit.

[0013] Preferably, the valve core includes a third position state, which includes an extended position and a shortened position. When the valve core is in the extended position, the A and E ports of the valve body are connected, the B and D ports are connected, and the G and C ports are connected. The first output pipeline supplies liquid to the first oil chamber, and the second output pipeline is connected to the return pipeline, causing a negative pressure in the branch circuit. The second oil chamber returns liquid through the return pipeline. When the valve core is in the shortened position, the A and G ports of the valve body are connected, and the E and C ports of the valve body are connected. The first output pipeline pumps liquid into the second oil chamber, and the first oil chamber returns liquid through the return pipeline.

[0014] Preferably, the valve core includes a fourth position state. When the valve core is in the fourth position state, the E interface and H interface of the valve body are connected, the F interface and G interface are connected, the first pipeline and the fourth pipeline are connected, and the second pipeline and the third pipeline are connected, so that the first oil chamber and the second oil chamber are connected.

[0015] Preferably, the valve core includes a fourth position state. When the valve core is in the fourth position state, the E interface and H interface of the valve body are connected, the first pipeline and the fourth pipeline are connected, and the first oil chamber and the second oil chamber are connected.

[0016] Preferably, the valve core includes a fifth position state. When the valve core is in the fifth position state, the A and E ports of the valve body are connected, the F and C ports are connected, and the H and D ports are connected. The adjustable check valve is set to have a predetermined conduction pressure. When the pressure in the first oil chamber increases to the predetermined value, the adjustable check valve is opened, and the first oil chamber is connected to the branch circuit.

[0017] Preferably, the valve core is rotatable relative to the valve body or slides along its axis to change the position of the valve core.

[0018] Compared with the prior art, the advantages of the present invention are as follows:

[0019] This application provides power to the hydraulic drive rod through two supply pipes, and the first and second oil chambers of the hydraulic drive rod are both connected to the control valve through two branches. The return pipe of the system has four input ends, and the control valve can change different supply and return channels by changing the position of the valve core, which is highly flexible. In addition, an adjustable check valve is set in one of the return branches, which can control the conduction state according to the pressure of the supply or return liquid, so as to realize more needs and control schemes.

[0020] It should be understood that all combinations of the foregoing concepts and the additional concepts described in more detail below may be considered part of the inventive subject matter of this disclosure, provided that such concepts do not contradict each other. Furthermore, all combinations of the claimed subject matter are considered part of the inventive subject matter of this disclosure.

[0021] The foregoing and other aspects, embodiments, and features of the teachings of the present invention will be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the invention, such as features and / or beneficial effects of exemplary embodiments, will become apparent from the following description or may be learned through practice of specific embodiments according to the teachings of the present invention. Attached Figure Description

[0022] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in the various figures may be denoted by the same reference numeral. For clarity, not every component is labeled in each figure. Embodiments of various aspects of the invention will now be described by way of example and with reference to the accompanying drawings, wherein:

[0023] Figure 1 This is a schematic diagram of the control system of the excavator hydraulic pump shown in this invention;

[0024] Figure 2 This is a schematic diagram of the control valve shown in this invention;

[0025] Figure 3 This is a schematic diagram of the valve core in the first position, in its extended position, as shown in this invention.

[0026] Figure 4 This is a schematic diagram of the valve core in the first position state of the present invention, in the shortened position.

[0027] Figure 5 This is a schematic diagram of the valve core in the second position, in its extended position, as shown in this invention.

[0028] Figure 6 This is a schematic diagram of the valve core in the second position, in the shortened position, as shown in this invention.

[0029] Figure 7 This is a schematic diagram of the valve core in the third position, in the extended position, as shown in this invention.

[0030] Figure 8 This is a schematic diagram of the valve core in the shortened position of the third position as shown in this invention;

[0031] Figure 9 This is a schematic diagram of the valve core in the fourth position state as shown in this invention;

[0032] Figure 10 This is a schematic diagram of the valve core in the fifth position of the present invention, in its extended position. Detailed Implementation

[0033] To better understand the technical content of the present invention, specific embodiments are described below in conjunction with the accompanying drawings.

[0034] Various aspects of the invention are described in this disclosure with reference to the accompanying drawings, which illustrate numerous illustrative embodiments. The embodiments of this disclosure are not necessarily intended to encompass all aspects of the invention. It should be understood that the various concepts and embodiments described above, as well as those described in more detail below, can be implemented in many ways with any excavator hydraulic pump control system, because the concepts and embodiments disclosed herein are not limited to any particular implementation. Furthermore, some aspects of the invention disclosed may be used alone or in any suitable combination with other aspects of the invention disclosed.

[0035] Combination Figure 1As shown, this invention proposes a control system for an excavator hydraulic pump, including an oil tank 10, a hydraulic pump 20, a return line 30, a control valve 40, and a hydraulic drive rod 50. The oil tank 10 is used to store hydraulic oil. The input end of the hydraulic pump 20 is connected to the oil tank 10. The hydraulic pump 20 has two independent output lines. The output ends of the first output line 21 and the second output line 22 are connected to the A port and B port of the control valve 40 respectively through a throttle valve 23. The throttle valve 23 is used to control the flow rate from the first output line 21 or the second output line 22 to the control valve 40.

[0036] Optionally, the hydraulic pump 20 has two pump chambers and two valve cores, which are coaxially connected by a motor. The two valve cores correspond to an independent output pipeline, namely the first output pipeline 21 and the second output pipeline 22. The first output pipeline 21 and the second output pipeline 22 are equipped with adjustable throttle valves 23. By adjusting the opening of the throttle valve 23, the flow rate entering the control valve 40 in the output pipeline can be adjusted. The excess flow rate flows into the return pipeline 30 from the relief valve 24.

[0037] Furthermore, the return line 30 includes four input terminals and one output terminal. The first and second input terminals are connected to the first output line 21 and the second output line 22 through the overflow valve 24. The third input terminal is connected to the C interface of the control valve 40, the fourth input terminal is connected to the D interface of the control valve 40, and the output terminal of the return line 30 is connected to the oil tank 10.

[0038] The hydraulic drive rod 50 includes a first oil chamber 51, a second oil chamber 52, and a hydraulic rod 53. The first oil chamber 51 is connected to the E port and F port of the control valve 40 through the first pipe 511 and the second pipe 512, respectively. The second oil chamber 52 is connected to the G port and H port of the control valve 40 through the third pipe 522 and the fourth pipe 521, respectively.

[0039] Preferably, the hydraulic drive rod is used for the drive cylinder of the 50-position bucket.

[0040] Thus, the first oil chamber 51 and the second oil chamber 52 of the hydraulic drive rod 50 are connected to the pump fluid pipeline and the return fluid pipeline, respectively. By controlling the connection status of the first oil chamber 51 and the second oil chamber 52 with the pump fluid pipeline and the return fluid pipeline, the extension or shortening of the hydraulic drive rod 50 can be controlled.

[0041] Among them, a branch circuit 31 is provided between the C interface and the return pipeline 30. An adjustable check valve is provided on the branch circuit 31. By setting an adjustable check valve on the return oil branch, the opening and closing pressure of the return oil branch can be controlled. In particular, when the pressure in the first oil chamber 51 exceeds the preset value, the return oil branch can be opened to release the pressure.

[0042] Thus, when the excavator bucket is working on soil layers with pipes or cables, if it encounters pipes or cables with greater hardness, and the excavator bucket stops digging due to resistance, the pressure in the first oil chamber 51 increases. When the pressure increases to a threshold, it is released through the return oil branch to avoid causing unexpected damage.

[0043] Furthermore, the control valve 40 includes a valve body 41 and a valve core 42, the valve core 42 being configured to control the connection state of various interfaces on the valve body 41 by changing its position.

[0044] like Figure 2 As shown, in an optional embodiment, the valve body 41 is constructed as a hollow column with predetermined positions on its surface having various interfaces. The valve core 42 can rotate relative to the valve body 41 or slide along its axis to change the position state of the valve core 42, so that the various interfaces have different connection states.

[0045] In an optional embodiment, the valve core 42 includes a first position state, which is the normal operating state of the bucket.

[0046] The first position state includes an elongated position and a shortened position, such as Figure 1 and Figure 3 As shown, when the valve core 42 is in the extended position, the A and E ports of the valve body 41 are connected, and the G and C ports of the valve body 41 are connected. The first output pipe 21 pumps liquid into the first oil chamber 51, and the second oil chamber 52 returns liquid through the return pipe 30. When the valve core 42 is in the shortened position, as... Figure 1 and Figure 4 As shown, the A and G ports of the valve body 41 are connected, and the E and C ports of the valve body 41 are connected. The first output pipeline 21 pumps liquid into the second oil chamber 52, and the first oil chamber 51 returns liquid through the return pipeline 30.

[0047] Thus, during normal excavation, fluid is pumped from the first output pipe 21 to the first oil chamber 51 via the first pipe 511, and returned via the third pipe 522, branch circuit 31, and return pipe 30. The opening pressure of the adjustable check valve is set to the minimum pressure. The pumping flow rate of the first output pipe 21 determines the extension of the hydraulic rod 53. When the hydraulic rod 53 is in the shortened state, fluid is pumped from the first output pipe 21 to the second oil chamber 52 via the third pipe 522, and returned via the first pipe 511, branch circuit 31, and return pipe 30. The pumping flow rate of the first output pipe 21 determines the shortening of the hydraulic rod 53.

[0048] In an optional embodiment, the valve core 42 includes a second position state that can increase the extension and retraction speed of the bucket.

[0049] The second position includes an extended position and a retracted position. When the valve core 42 is in the extended position, such as... Figure 1 and Figure 5 As shown, the valve body 41 has ports A and E connected, ports B and F connected, ports G and C connected, and ports H and D connected. The first output pipe 21 and the second output pipe 22 pump fluid into the first oil chamber 51. The second oil chamber 52 returns fluid through the return pipe 30 and the branch circuit 31. When the valve core 42 is in the shortened position, as... Figure 1 and Figure 6 As shown, the valve body 41 has A and G ports connected, B and H ports connected, E and C ports connected, and F and D ports connected. The first output pipe 21 and the second output pipe 22 pump liquid into the second oil chamber 52. The first oil chamber 51 returns liquid through the return pipe 30 and the branch circuit 31.

[0050] Thus, by using the first output pipe 21 and the second output pipe 22 for dual-channel pumping and dual-circuit return, the pumping speed of hydraulic oil in the first oil chamber 51 or the second oil chamber 52 is doubled, thereby increasing the extension and retraction speed of the hydraulic rod 53.

[0051] In an optional embodiment, the valve core 42 includes a third position state that can increase the driving force when the bucket is digging.

[0052] The third position includes an extended position and a retracted position. When the valve core 42 is in the extended position, such as... Figure 1 and Figure 7 As shown, ports A and E of valve body 41 are connected, ports B and D are connected, and ports G and C are connected. The first output pipe 21 supplies liquid to the first oil chamber 51, and the second output pipe 22 is connected to the return pipe 30, creating a negative pressure in the branch circuit 31. Liquid returns to the second oil chamber 52 through the return pipe 30. When the valve core 42 is in the shortened position, as... Figure 1 and Figure 8 As shown, the A and G ports of the valve body 41 are connected, and the E and C ports of the valve body 41 are connected. The first output pipeline 21 pumps liquid into the second oil chamber 52, and the first oil chamber 51 returns liquid through the return pipeline 30.

[0053] Thus, the first output pipe 21 supplies liquid to the first oil chamber 51 normally, while the second output pipe 22 is connected to the return pipe 30. The high flow rate causes the branch circuit 31 to generate negative pressure, that is, there is negative pressure in the second oil chamber 52. The first oil chamber 51 has a larger pressure difference than the second oil chamber 52, which is beneficial to make the hydraulic rod 53 have greater pressure during the extension process.

[0054] In an optional embodiment, the valve core 42 includes a fourth position state in which the bucket can move freely.

[0055] Among them, such as Figure 9As shown, when the valve core 42 is in the fourth position, the E and H ports of the valve body 41 are connected, the F and G ports are connected, the first pipeline 511 and the fourth pipeline 521 are connected, and the second pipeline 512 and the third pipeline 522 are connected, so that the first oil chamber 51 and the second oil chamber 52 are connected.

[0056] Thus, the first oil chamber 51 and the second oil chamber 52 of the hydraulic drive rod 50 are interconnected through a dual channel, and the hydraulic rod 53 can extend and retract freely. When the excavator is transporting the plate on a flatbed truck or ship, the bucket will not cause a large impact on the thin plate because the hydraulic rod 53 is flexible and movable, thus protecting the thin plate from damage caused by the bucket collision.

[0057] Furthermore, in an optional embodiment, the valve core 42 includes a fourth position state. When the valve core 42 is in the fourth position state, the E interface and H interface of the valve body 41 are connected, the first pipeline 511 and the fourth pipeline 521 are connected, and the first oil chamber 51 and the second oil chamber 52 are connected.

[0058] Thus, the first oil chamber 51 and the second oil chamber 52 of the hydraulic drive rod 50 are interconnected through a single channel, and the hydraulic rod 53 can extend and retract freely. Compared with the dual channel, the hydraulic rod 53 can generate greater damping force during free extension and retraction to prevent the bucket from jumping when bumping.

[0059] In an optional embodiment, the valve core 42 includes a fifth position state. In the fifth position state, after the bucket encounters significant resistance during digging, the driving force for the extension of the hydraulic rod 43 can be released, thus preventing the hydraulic rod 43 from continuing to extend and causing uncontrollable damage.

[0060] When valve core 42 is in the fifth position, such as Figure 10 As shown, the A and E ports of the valve body 41 are connected, the F and C ports are connected, and the H and D ports are connected. The adjustable check valve is set to have a predetermined conduction pressure. When the pressure in the first oil chamber 51 increases to the predetermined value, the adjustable check valve is opened, and the first oil chamber 51 is connected to the branch circuit 31.

[0061] In this way, an appropriate one-way valve conduction pressure value can be set according to the excavation object. When the bucket is blocked by foreign objects during the excavation process, preventing the hydraulic rod 43 from continuing to extend, the pressure in the first oil chamber 51 increases. After it increases to a predetermined value, the adjustable one-way valve is opened, and the first oil chamber 51 is connected to the branch circuit 31 to release the pressure in the first oil chamber 51, so as to avoid the continuous increase causing the foreign objects to be damaged.

[0062] In conjunction with the above embodiments, this application provides power to the hydraulic drive rod through two supply pipes, and the first and second oil chambers of the hydraulic drive rod are both connected to the control valve through two branches. The system's return pipe has four input ends, and the control valve can change different supply and return channels by changing the position of the valve core, which is highly flexible. In addition, an adjustable check valve is set in one of the return branches, which can control the conduction state according to the pressure of the supply or return liquid, so as to realize more needs and control schemes.

[0063] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A control system for a hydraulic pump of an excavator, characterized by, include: Oil tank (10) is used to store hydraulic oil; The hydraulic pump (20) has its input end connected to the oil tank (10). The hydraulic pump (20) has two independent output lines. The output ends of the first output line (21) and the second output line (22) are connected to the A and B ports of the control valve (40) respectively through the throttle valve (23). The throttle valve (23) is used to control the flow rate of the first output line (21) or the second output line (22) to the control valve (40). The return line (30) includes four input terminals and one output terminal. The first input terminal and the second input terminal are connected to the first output line (21) and the second output line (22) through the overflow valve (24). The third input terminal is connected to the C interface of the control valve (40). The fourth input terminal is connected to the D interface of the control valve (40). The output terminal of the return line (30) is connected to the oil tank (10). The hydraulic drive rod (50) includes a first oil chamber (51), a second oil chamber (52), and a hydraulic rod (53). The first oil chamber (51) is connected to the E port and F port of the control valve (40) through the first pipeline (511) and the second pipeline (512), respectively. The second oil chamber (52) is connected to the G port and H port of the control valve (40) through the third pipeline (522) and the fourth pipeline (521), respectively. Among them, a branch circuit (31) is provided between the C interface and the return pipeline (30), and an adjustable check valve is provided on the branch circuit (31). The control valve (40) includes a valve body (41) and a valve core (42). The valve core (42) is configured to control the connection status of each interface on the valve body (41) by changing its position. The valve core (42) includes a first position state, which includes an extended position and a shortened position. When the valve core (42) is in the extended position, the A and E ports of the valve body (41) are connected, the G and C ports of the valve body (41) are connected, the first output pipe (21) pumps liquid into the first oil chamber (51), and the second oil chamber (52) returns liquid through the return pipe (30). When the valve core (42) is in the shortened position, the A and G ports of the valve body (41) are connected, the E and C ports of the valve body (41) are connected, the first output pipe (21) pumps liquid into the second oil chamber (52), and the first oil chamber (51) returns liquid through the return pipe (30). The valve core (42) includes a second position state, which includes an extended position and a shortened position. When the valve core (42) is in the extended position, the A and E ports of the valve body (41) are connected, the B and F ports are connected, the G and C ports are connected, and the H and D ports are connected. The first output pipe (21) and the second output pipe (22) pump liquid into the first oil chamber (51), and the second oil chamber (52) returns liquid through the return pipe (30) and the branch circuit (31). When the valve core (42) is in the shortened position, the A and G ports of the valve body (41) are connected, the B and H ports are connected, the E and C ports are connected, and the F and D ports are connected. The first output pipe (21) and the second output pipe (22) pump liquid into the second oil chamber (52), and the first oil chamber (51) returns liquid through the return pipe (30) and the branch circuit (31). The valve core (42) includes a third position state, which includes an extended position and a shortened position. When the valve core (42) is in the extended position, the A and E ports of the valve body (41) are connected, the B and D ports are connected, and the G and C ports are connected. The first output pipeline (21) supplies liquid to the first oil chamber (51), and the second output pipeline (22) is connected to the return pipeline (30), so that the branch circuit (31) generates negative pressure. The second oil chamber (52) returns liquid through the return pipeline (30). When the valve core (42) is in the shortened position, the A and G ports of the valve body (41) are connected, and the E and C ports of the valve body (41) are connected. The first output pipeline (21) pumps liquid into the second oil chamber (52), and the first oil chamber (51) returns liquid through the return pipeline (30). The valve core (42) includes a fourth position state. When the valve core (42) is in the fourth position state, the E interface and H interface of the valve body (41) are connected, the F interface and G interface are connected, the first pipeline (511) and the fourth pipeline (521) are connected, and the second pipeline (512) and the third pipeline (522) are connected, so that the first oil chamber (51) and the second oil chamber (52) are connected; or when the valve core (42) is in the fourth position state, the E interface and H interface of the valve body (41) are connected, the first pipeline (511) and the fourth pipeline (521) are connected, so that the first oil chamber (51) and the second oil chamber (52) are connected. The valve core (42) includes a fifth position state. When the valve core (42) is in the fifth position state, the A and E interfaces of the valve body (41) are connected, the F and C interfaces are connected, and the H and D interfaces are connected. The adjustable check valve is set to have a predetermined conduction pressure. When the pressure in the first oil chamber (51) increases to the predetermined value, the adjustable check valve is turned on, and the first oil chamber (51) is connected to the branch circuit (31). The valve core (42) can rotate relative to the valve body (41) or slide along its axis to change the position of the valve core (42).

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