Hydraulic control system and working machine

Abstract

The present application relates to the technical field of hydraulic system, and proposes a hydraulic control system and working machine. In the hydraulic control system, the swash plate oil cylinder comprises a cylinder barrel and a piston. The piston is in sliding connection with the cylinder barrel. The piston is connected with the swash plate of the walking motor. The spring cavity, the first working cavity and the second working cavity are formed between the piston and the cylinder barrel. The acting area of the first working cavity is larger than that of the second working cavity. The swash plate control valve is connected with the oil source and the swash plate oil cylinder, and is used for controlling the communication state of the oil source with the first working cavity and the second working cavity. Through the structure setting, the first working cavity, the second working cavity and the spring cavity are arranged between the cylinder barrel and the piston, so that the difference between the acting area of the piston in the first working cavity and the acting area of the piston in the second working cavity is formed. The communication state of the first working cavity and the second working cavity with the oil source is controlled through the swash plate control valve, so that the walking motor realizes the switching of more speed states, and the speed regulating range of the walking motor is expanded.

Description

Technical Field

[0001] This invention relates to the field of hydraulic system technology, and in particular to a hydraulic control system and a working machine. Background Technology

[0002] Excavators are important types of construction machinery. Currently, excavators are typically driven by a travel motor. The travel motor is equipped with a swashplate, and the swashplate angle is adjusted by a hydraulic cylinder, thereby controlling the travel motor's speed. In existing technology, the piston rod of the swashplate cylinder has an oil chamber and a spring chamber on each side. When the oil chamber is empty, the spring drives the piston to rotate the swashplate, causing the travel motor to operate at low speed. When the oil chamber is filled with oil, the oil pressure overcomes the spring force, causing the spring to rotate, thus causing the travel motor to operate at low speed. In this drive structure, the travel motor can only achieve dual-speed adjustment, and its speed adjustment range is relatively small. Summary of the Invention

[0003] This invention provides a hydraulic control system and a working machine to solve or improve the problem that the existing excavator's travel motor can only achieve dual-speed adjustment, and its speed adjustment range is relatively small.

[0004] According to a first aspect of the present invention, a hydraulic control system is provided, including a swashplate cylinder, a swashplate control valve, an oil source, and a travel motor.

[0005] The swashplate cylinder includes a cylinder barrel and a piston. The piston is slidably connected to the cylinder barrel. The piston is connected to the swashplate of the travel motor to adjust the angle of the swashplate. A spring chamber, a first working chamber, and a second working chamber are formed between the piston and the cylinder barrel, with the functional area of ​​the first working chamber being larger than that of the second working chamber. The swashplate control valve is connected to the oil source and the swashplate cylinder, and is used to control the communication state between the oil source and the first and second working chambers.

[0006] According to a hydraulic control system provided by the present invention, the cylinder includes a first cylinder body and a second cylinder body. The piston includes a first piston body, a second piston body, and a connecting section.

[0007] The first cylinder and the second cylinder are connected. The diameter of the first cylinder is smaller than the diameter of the second cylinder. The first piston body is slidably connected to the first cylinder. The second piston body is slidably connected to the second cylinder. The first piston body and the second piston body are connected by a connecting section. The diameter of the connecting section is smaller than the diameter of the first piston body. The diameter of the first piston body is smaller than the diameter of the second piston body. The effective area of ​​the end face of the first piston body away from the connecting section is greater than the difference between the effective area of ​​the end face of the first piston body near the connecting section and the effective area of ​​the end face of the second piston body near the connecting section.

[0008] According to a hydraulic control system provided by the present invention, the piston further includes a piston rod. The piston rod is connected to the side of the second piston body away from the first piston body and is connected to the swashplate. A first working chamber is formed between the end of the first piston body away from the second piston body and the first cylinder. A second working chamber is formed between the end of the second piston body near the first piston body and the second cylinder. The spring cavity is formed between the end of the second piston body away from the first piston body and the second cylinder.

[0009] According to a hydraulic control system provided by the present invention, the oil source includes a hydraulic pump, an accumulator, and an oil tank. The swashplate control valve includes a three-position five-way directional valve.

[0010] The first working port of the three-position five-way directional valve is connected to the first working chamber. The second working port of the three-position five-way directional valve is connected to the second working chamber. The third and fourth working ports of the three-position five-way directional valve are both connected to the oil tank. The fifth working port of the three-position five-way directional valve is connected to the accumulator. The accumulator is connected to the hydraulic pump.

[0011] According to a hydraulic control system provided by the present invention, the three-position five-way directional valve is provided with a first working position, a second working position and a third working position.

[0012] In the first working position, the first working oil port is connected to the fifth working oil port, while the second working oil port, the third working oil port, and the fourth working oil port are mutually blocked.

[0013] In the second working position, the second working oil port is connected to the fifth working oil port, while the first working oil port, the third working oil port, and the fourth working oil port are mutually blocked.

[0014] In the third working position, the first working port is connected to the third working port, the second working port is connected to the fourth working port, and the fifth working port is cut off from the first, second, third, and fourth working ports.

[0015] According to a hydraulic control system provided by the present invention, the hydraulic control system further includes a rotary motor and a rotary control valve.

[0016] The first inlet and return port of the rotary motor is connected to the rotary control valve via a first pipeline. The second inlet and return port of the rotary motor is connected to the rotary control valve via a second pipeline. The rotary control valve is connected to the hydraulic pump and the oil tank. The rotary control valve is used to control the communication status between the first inlet and return port, the second inlet and return port, the hydraulic pump, and the oil tank.

[0017] According to a hydraulic control system provided by the present invention, the hydraulic control system further includes an overflow valve, a first shut-off check valve, and a second shut-off check valve.

[0018] The first pipeline is connected to the oil inlet of the overflow valve through the first shut-off check valve, the second pipeline is connected to the oil inlet of the overflow valve through the second shut-off check valve, and the oil outlet of the overflow valve is connected to the oil tank.

[0019] The hydraulic control system also includes a first replenishing check valve and a second replenishing check valve. The first pipeline is connected to the oil tank through the first replenishing check valve, and the second pipeline is connected to the oil tank through the second replenishing check valve.

[0020] According to a hydraulic control system provided by the present invention, the hydraulic control system further includes a travel control valve. The travel control valve is connected to the hydraulic pump, the oil tank, and the travel motor, and is used to control the communication state of the travel motor, the hydraulic pump, and the oil tank.

[0021] The hydraulic control system further includes a rotary hand valve and a travel foot valve. The accumulator is connected to the rotary hand valve and the travel foot valve. The rotary hand valve is connected to the control port of the rotary control valve. The travel foot valve is connected to the control port of the travel control valve.

[0022] According to a hydraulic control system provided by the present invention, the hydraulic control system includes two sets of swashplate cylinders, a swashplate control valve, a travel motor, and a travel control valve. One set of the swashplate cylinders, swashplate control valve, travel motor, and travel control valve is used to drive the left travel mechanism of the working machine. The other set of the swashplate cylinders, swashplate control valve, travel motor, and travel control valve is used to drive the right travel mechanism of the working machine.

[0023] According to a second aspect of the present invention, a working machine is provided, including a hydraulic control system as described above.

[0024] The hydraulic control system provided by this invention includes a swashplate cylinder, a swashplate control valve, an oil source, and a travel motor. The swashplate cylinder includes a cylinder barrel and a piston. The piston can connect to the swashplate of the travel motor and slides inside the cylinder barrel. A spring chamber, a first working chamber, and a second working chamber are formed between the cylinder barrel and the piston. For example, the second working chamber is located between the first working chamber and the spring chamber. One working port of the swashplate control valve is connected to the first and second working chambers of the swashplate cylinder, and the other working port is connected to the oil source. The swashplate control valve is used to control the communication state between the oil source and the first and second working chambers. For example, the communication state includes at least the following: the oil source is cut off from both the first and second working chambers; the oil source is connected to the first working chamber; and the oil source is connected to the second working chamber. The effective area of ​​the piston in the first working chamber is larger than the effective area of ​​the piston in the second working chamber. Therefore, the pressure exerted on the piston by the oil in the first working chamber is greater than the pressure exerted on the piston by the oil in the second working chamber. In other words, the distance the piston moves when oil flows into the first working chamber is greater than the distance the piston moves when oil flows into the second working chamber. Specifically, when the oil source is cut off from both the first and second working chambers, the piston, driven by the spring in the spring chamber, rotates the swashplate to its maximum angle, allowing the travel motor to operate at its lowest speed. When the oil source is connected to the first working chamber, the oil in the first working chamber drives the piston to overcome the spring force and rotate the swashplate to its minimum angle, allowing the travel motor to operate at its highest speed. When the oil source is connected to the second working chamber, the oil in the second working chamber drives the piston to overcome the spring force and rotate the swashplate to its intermediate angle, allowing the travel motor to operate at its intermediate speed.

[0025] With this structural design, a first working chamber, a second working chamber, and a spring chamber are set between the cylinder and piston of the swashplate cylinder. This creates a difference between the working area of ​​the piston in the first working chamber and the working area of ​​the piston in the second working chamber. The connection between the first and second working chambers and the oil source is controlled by the swashplate control valve, enabling the travel motor to switch between more speed states and expanding the speed range of the travel motor.

[0026] Furthermore, the working machinery provided by the present invention, since it includes the hydraulic control system described above, also possesses the advantages described above. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a system schematic diagram of the hydraulic control system provided by the present invention;

[0029] Figure 2 yes Figure 1 A magnified view of a section at point A in the middle;

[0030] Figure 3 yes Figure 1 A magnified view of a section at point B in the middle;

[0031] Figure label:

[0032] 100. Swashplate cylinder; 111. First cylinder; 112. Second cylinder; 121. First piston body; 122. Second piston body; 123. Connecting section; 124. Piston rod; 131. First working chamber; 132. Second working chamber; 133. Spring chamber; 200. Swashplate control valve; 310. Oil tank; 320. Hydraulic pump; 330. Accumulator; 340. Proportional relief valve; 400. Travel motor; 410. Travel control valve; 420. Travel foot valve; 500. Rotary motor; 510. Rotary control valve; 520. Rotary hand valve; 531. First pipeline; 532. Second pipeline; 541. First shut-off check valve; 542. Second shut-off check valve; 543. Relief valve; 551. First replenishing check valve; 552. Second replenishing check valve. Detailed Implementation

[0033] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0034] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., 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 the embodiments of the present 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 the embodiments of the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0035] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0036] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0037] In the description of this specification, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate different embodiments or examples and features of different embodiments or examples described in this specification to make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer. The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] The following is combined Figures 1 to 3 This invention describes a hydraulic control system and a working machine according to embodiments of the present invention. It should be understood that the following description is merely an illustrative embodiment of the invention and does not constitute any particular limitation on the invention.

[0039] An embodiment of the first aspect of the present invention provides a hydraulic control system, such as Figure 1As shown, the hydraulic control system includes a swashplate cylinder 100, a swashplate control valve 200, an oil source, and a travel motor 400.

[0040] The swashplate cylinder 100 includes a cylinder barrel and a piston. The piston is slidably connected to the cylinder barrel. The piston is connected to the swashplate of the travel motor 400 to adjust the angle of the swashplate. A spring chamber 133, a first working chamber 131, and a second working chamber 132 are formed between the piston and the cylinder barrel. The effective area of ​​the first working chamber 131 is larger than the effective area of ​​the second working chamber 132. The swashplate control valve 200 is connected to the oil source and the swashplate cylinder 100, and is used to control the communication state between the oil source and the first working chamber 131 and the second working chamber 132.

[0041] The hydraulic control system provided by this invention includes a swashplate cylinder 100, a swashplate control valve 200, an oil source, and a travel motor 400. The swashplate cylinder 100 includes a cylinder barrel and a piston. The piston can connect to the swashplate of the travel motor 400 and slides inside the cylinder barrel. A spring chamber 133, a first working chamber 131, and a second working chamber 132 are formed between the cylinder barrel and the piston. For example, the second working chamber 132 is located between the first working chamber 131 and the spring chamber 133. One working port of the swashplate control valve 200 is connected to the first working chamber 131 and the second working chamber 132 of the swashplate cylinder 100, and the other working port of the swashplate control valve 200 is connected to the oil source. The swashplate control valve 200 is used to control the communication state between the oil source and the first working chamber 131 and the second working chamber 132. For example, the communication state includes at least the following: the oil source is cut off from both the first working chamber 131 and the second working chamber 132; the oil source is connected to the first working chamber 131; and the oil source is connected to the second working chamber 132. The effective area of ​​the piston in the first working chamber 131 is larger than that of the piston in the second working chamber 132. Therefore, the pressure exerted on the piston by the oil in the first working chamber 131 is greater than the pressure exerted on the piston by the oil in the second working chamber 132. In other words, the distance the piston moves when oil flows into the first working chamber 131 is greater than the distance the piston moves when oil flows into the second working chamber 132. Specifically, when the oil source is cut off from both the first and second working chambers 131 and 132, the piston drives the swashplate to rotate to its maximum angle under the driving action of the spring in the spring chamber 133, so that the travel motor 400 operates at its lowest speed. When the oil source is connected to the first working chamber 131, the oil in the first working chamber 131 drives the piston to overcome the spring force and rotate the swashplate to its minimum angle, so that the travel motor 400 operates at its highest speed. When the oil source is connected to the second working chamber 132, the oil in the second working chamber 132 drives the piston to overcome the spring force and rotate the swashplate to its intermediate angle, so that the travel motor 400 operates at its intermediate speed.

[0042] With this structural arrangement, a first working chamber 131, a second working chamber 132, and a spring chamber 133 are provided between the cylinder and piston of the swashplate cylinder 100. This creates a difference between the effective area of ​​the piston in the first working chamber 131 and the effective area of ​​the piston in the second working chamber 132. The swashplate control valve 200 controls the connection between the first working chamber 131 and the second working chamber 132 and the oil source, enabling the travel motor 400 to switch between more speed states and expanding the speed regulation range of the travel motor 400.

[0043] In one embodiment of the present invention, the cylinder includes a first cylinder body 111 and a second cylinder body 112. The piston includes a first piston body 121, a second piston body 122, and a connecting section 123.

[0044] The first cylinder 111 is connected to the second cylinder 112. The diameter of the first cylinder 111 is smaller than the diameter of the second cylinder 112. The first piston body 121 is slidably connected inside the first cylinder 111. The second piston body 122 is slidably connected inside the second cylinder 112. The first piston body 121 and the second piston body 122 are connected by a connecting section 123. The diameter of the connecting section 123 is smaller than the diameter of the first piston body 121. The diameter of the first piston body 121 is smaller than the diameter of the second piston body 122. The effective area of ​​the end face of the first piston body 121 away from the connecting section 123 is greater than the difference between the effective area of ​​the end face of the first piston body 121 near the connecting section 123 and the effective area of ​​the end face of the second piston body 122 near the connecting section 123.

[0045] Furthermore, in one embodiment of the present invention, the piston further includes a piston rod 124. The piston rod 124 is connected to the side of the second piston body 122 away from the first piston body 121 and is connected to a swashplate. A first working chamber 131 is formed between the end of the first piston body 121 away from the second piston body 122 and the first cylinder 111. A second working chamber 132 is formed between the end of the second piston body 122 near the first piston body 121 and the second cylinder 112. A spring cavity 133 is formed between the end of the second piston body 122 away from the first piston body 121 and the second cylinder 112.

[0046] For example, such as Figure 1 and Figure 2As shown in the diagram, the cylinder of the swashplate cylinder 100 is arranged horizontally. A first cylinder 111 and a second cylinder 112 are coaxially connected, with the first cylinder 111 located to the left of the second cylinder 112. The inner diameter of the first cylinder 111 is smaller than the inner diameter of the second cylinder 112. A first piston body 121 and a second piston body 122 are connected by a connecting section 123, and all three are coaxially arranged. The first piston body 121 is adapted to the first cylinder 111 so that the first piston body 121 can slide along the first cylinder 111 in a sealed manner, and the second piston body 122 is adapted to the second cylinder 112 so that the second piston body 122 can slide along the second cylinder 112 in a sealed manner. A first working chamber 131 is formed between the left end face of the first piston body 121 and the left end face of the first cylinder 111. A second working chamber 132 is formed between the left end face of the second piston body 122 and the left end face of the second cylinder 112. A spring chamber 133 is formed between the right end face of the second piston body 122 and the right end face of the second cylinder 112. A spring is installed in the spring chamber 133. During the sliding process of the first piston body 121 and the second piston body 122, the first piston body 121 cannot separate from the first cylinder 111 to ensure that the first working chamber 131 and the second working chamber 132 are completely separated. The area of ​​the left end face of the first piston body 121 is greater than the area difference between the left end face of the second piston body 122 and the right end face of the first piston body 121. Therefore, when oil is supplied to the first working chamber 131 or the second working chamber 132, the piston can be driven to move to the right against the spring force to reduce the swashplate angle. When oil is supplied to the first working chamber 131 and the second working chamber 132, the distance the piston moves is different, the rotation angle of the swashplate is different, and consequently, the speed of the travel motor 400 is also different.

[0047] In one embodiment of the present invention, the oil source includes a hydraulic pump 320, an accumulator 330, and an oil tank 310. The swashplate control valve 200 includes a three-position five-way directional valve.

[0048] The first working port of the three-position five-way directional valve is connected to the first working chamber 131. The second working port of the three-position five-way directional valve is connected to the second working chamber 132. The third and fourth working ports of the three-position five-way directional valve are both connected to the oil tank 310. The fifth working port of the three-position five-way directional valve is connected to the accumulator 330. The accumulator 330 is connected to the hydraulic pump 320.

[0049] For example, the three-position five-way directional valve is a hydraulically controlled directional valve, with a spring on one side of the valve core. A hydraulically controlled port is located on the other side of the valve core. The hydraulically controlled port is connected to the accumulator 330 via a proportional relief valve 340.

[0050] Furthermore, in one embodiment of the present invention, the three-position five-way directional valve is provided with a first working position, a second working position and a third working position.

[0051] In the first working position, the first working port is connected to the fifth working port, while the second, third, and fourth working ports are mutually blocked.

[0052] In the second working position, the second working port is connected to the fifth working port, while the first working port, the third working port, and the fourth working port are mutually cut off.

[0053] In the third working position, the first working port is connected to the third working port, the second working port is connected to the fourth working port, and the fifth working port is cut off from the first, second, third, and fourth working ports.

[0054] Specifically, such as Figure 1 and Figure 2As shown, the three-position five-way directional valve includes a first working port, a second working port, a third working port, a fourth working port, and a fifth working port. A hydraulic control port and a spring are respectively provided on both sides of the valve core. The first working port is connected to the first working chamber 131, the second working port is connected to the second working chamber 132, and both the third and fourth working ports are connected to the oil tank 310, or in other words, both the third and fourth working ports are connected to the low-pressure return oil port. The fifth working port is connected to the outlet of the accumulator 330. The hydraulic control port is connected to the outlet of the accumulator 330 through a proportional relief valve 340. The outlet of the hydraulic pump 320 is connected to the inlet of the accumulator 330. The hydraulic pump 320 can charge the accumulator 330. The three-position five-way directional valve can switch between the first working position, the second working position, and the third working position. Specifically, by controlling the flow rate of the proportional relief valve 340, the pressure input to the hydraulic control port of the three-position five-way directional valve can be controlled, thereby switching it between the first, second, and third working positions. When the three-position five-way directional valve is switched to the first working position, the first working port is connected to the fifth working port, while the second, third, and fourth working ports are mutually cut off. At this time, the accumulator 330 inputs oil into the first working chamber 131 through the fifth and first working ports, and the piston drives the swashplate to rotate to its minimum angle. When the three-position five-way directional valve is switched to the second working position, the second and fifth working ports are connected, while the first, third, and fourth working ports are mutually cut off. At this time, the accumulator 330 inputs oil into the second working chamber 132 through the fifth and second working ports, and the piston drives the swashplate to rotate to its intermediate angle. When the three-position five-way directional valve switches to the third working position, the first working port is connected to the third working port, the second working port is connected to the fourth working port, and the fifth working port is cut off from the first, second, third, and fourth working ports. At this time, there is no oil input in the first working chamber 131 and the second working chamber 132, and the spring-driven piston drives the swashplate to rotate to its maximum angle.

[0055] In one embodiment of the present invention, the hydraulic control system further includes a rotary motor 500 and a rotary control valve 510.

[0056] The first inlet and return oil ports of the rotary motor 500 are connected to the rotary control valve 510 via a first pipeline 531. The second inlet and return oil ports of the rotary motor 500 are connected to the rotary control valve 510 via a second pipeline 532. The rotary control valve 510 is connected to the hydraulic pump 320 and the oil tank 310. The rotary control valve 510 is used to control the connection status between the first inlet and return oil ports, the second inlet and return oil ports, the hydraulic pump 320, and the oil tank 310.

[0057] Furthermore, in one embodiment of the present invention, the hydraulic control system further includes an overflow valve 543, a first shut-off check valve 541, and a second shut-off check valve 542.

[0058] The first pipeline 531 is connected to the oil inlet of the relief valve 543 via the first shut-off check valve 541, and the second pipeline 532 is connected to the oil inlet of the relief valve 543 via the second shut-off check valve 542. The oil outlet of the relief valve 543 is connected to the oil tank 310.

[0059] The oil control system also includes a first replenishing check valve 551 and a second replenishing check valve 552. The first pipeline 531 is connected to the oil tank 310 through the first replenishing check valve 551, and the second pipeline 532 is connected to the oil tank 310 through the second replenishing check valve 552.

[0060] For example, such as Figure 1 and Figure 3 As shown, the rotary motor 500 includes two inlet and return ports, namely the first inlet and return port and the second inlet and return port. For example, the rotary control valve 510 includes four working ports, one of which is connected to the first inlet and return port via a first pipeline 531, one of which is connected to the second inlet and return port via a second pipeline 532, one of which is connected to the hydraulic pump 320, and one of which is connected to the oil tank 310. When the hydraulic pump 320 supplies oil to the first inlet and return port through the rotary control valve 510, and the second inlet and return port returns oil to the oil tank 310 through the rotary control valve 510, the rotary motor 500 rotates forward; when the hydraulic pump 320 supplies oil to the second inlet and return port through the rotary control valve 510, and the first inlet and return port returns oil to the oil tank 310 through the rotary control valve 510, the rotary motor 500 rotates in reverse.

[0061] The first oil inlet and return port are connected to the oil inlet of the relief valve 543 via a first shut-off check valve 541, and the second oil inlet and return port are connected to the oil inlet of the relief valve 543 via a second shut-off check valve 542. The oil outlet of the relief valve 543 is connected to the oil tank 310. The relief valve 543 here serves as a safety valve for the rotary motor 500. Compared to the existing technology where a separate relief valve 543 is installed at each of the first and second oil inlets and return ports, this control system reduces the number of relief valves 543, thus lowering costs.

[0062] A first replenishing check valve 551 is installed between the first pipeline 531 and the oil tank 310, and a second replenishing check valve 552 is installed between the second pipeline 532 and the oil tank 310. Alternatively, the first replenishing check valve 551 is installed between the first oil inlet / outlet and the oil tank 310, and the second replenishing check valve 552 is installed between the second oil inlet / outlet and the oil tank 310. This prevents the rotary motor 500 from sucking in cavitation and generating noise.

[0063] In one embodiment of the present invention, the hydraulic control system further includes a travel control valve 410. The travel control valve 410 is connected to the hydraulic pump 320, the oil tank 310 and the travel motor 400, and is used to control the connection state of the travel motor 400, the hydraulic pump 320 and the oil tank 310.

[0064] The hydraulic control system also includes a rotary hand valve 520 and a travel foot valve 420. An accumulator 330 is connected to the rotary hand valve 520 and the travel foot valve 420. The rotary hand valve 520 is connected to the control port of the rotary control valve 510. The travel foot valve 420 is connected to the control port of the travel control valve 410.

[0065] For example, the travel motor 400 has two oil inlet and return ports, which are respectively connected to the travel control valve 410. The travel control valve 410 is also connected to the hydraulic pump 320 and the oil tank 310. The travel control valve 410 controls the connection between the hydraulic pump 320 and the oil tank 310 and the two oil inlet and return ports of the travel motor 400, so that the travel motor 400 rotates in the forward direction, in the reverse direction, or stops rotating.

[0066] In addition, the hydraulic control system also includes a rotary hand valve 520 and a travel foot valve 420. The rotary hand valve 520 is connected to the control port of the rotary control valve 510 to control its operating state. The travel foot valve 420 is connected to the control port of the travel control valve 410 to control its connection / disconnection state. Both the rotary hand valve 520 and the travel foot valve 420 can be installed in the operator's cab of the machine. The driving hydraulic fluid for the travel foot valve 420 and the rotary hand valve 520 can be supplied through the accumulator 330.

[0067] In one embodiment of the present invention, such as Figure 1 As shown, the hydraulic control system includes two sets of swashplate cylinders 100, swashplate control valves 200, travel motors 400, and travel control valves 410. One set of swashplate cylinders 100, swashplate control valves 200, travel motors 400, and travel control valves 410 drives the left travel mechanism of the working machine. The other set of swashplate cylinders 100, swashplate control valves 200, travel motors 400, and travel control valves 410 drives the right travel mechanism of the working machine. Alternatively, the hydraulic system includes a left travel unit and a right travel unit, both with identical structures, including swashplate cylinders 100, swashplate control valves 200, travel motors 400, and travel control valves 410. The left travel unit drives the left travel mechanism of the working machine, and the right travel unit drives the right travel mechanism of the working machine.

[0068] A second aspect of the present invention provides a working machine including a hydraulic control system as described above.

[0069] For example, in one embodiment of the present invention, the aforementioned working machinery is an excavator.

[0070] It should be understood that the above embodiments are merely illustrative examples of the present invention and should not be construed as limiting the invention in any way. That is, the above-mentioned operating machinery includes, but is not limited to, excavators; other operating machinery including the above-mentioned hydraulic control system should also be within the scope of protection of the present invention.

[0071] Furthermore, the working machinery provided by the present invention, since it includes the hydraulic control system described above, also possesses the advantages described above.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hydraulic control system, characterized in that, Includes swashplate cylinder, swashplate control valve, hydraulic power supply, and travel motor. The swashplate cylinder includes a cylinder barrel and a piston. The piston is slidably connected to the cylinder barrel and connected to the swashplate of the travel motor to adjust the angle of the swashplate. A spring chamber, a first working chamber, and a second working chamber are formed between the piston and the cylinder barrel. The second working chamber is located between the first working chamber and the spring chamber. The effective area of ​​the first working chamber is larger than the effective area of ​​the second working chamber. The swashplate control valve is connected to the oil source and the swashplate cylinder and is used to control the communication state between the oil source and the first working chamber and the second working chamber. The connection state includes at least the following states: the oil source is cut off from both the first working chamber and the second working chamber; the oil source is connected to the first working chamber; and the oil source is connected to the second working chamber. When the oil source is cut off from both the first and second working chambers, the piston drives the swashplate to rotate to its maximum angle under the driving action of the spring in the spring chamber, so that the travel motor operates at its lowest speed. When the oil source is connected to the first working chamber, the oil in the first working chamber drives the piston to overcome the spring force and rotate the swashplate to its minimum angle, so that the travel motor operates at its highest speed. When the oil source is connected to the second working chamber, the oil in the second working chamber drives the piston to overcome the spring force and rotate the swashplate to its intermediate angle, so that the travel motor operates at its intermediate speed. The cylinder includes a first cylinder and a second cylinder, and the piston includes a first piston body, a second piston body, and a connecting section. The first cylinder is connected to the second cylinder, the diameter of the first cylinder is smaller than the diameter of the second cylinder, the first piston body is slidably connected to the first cylinder, the second piston body is slidably connected to the second cylinder, and the first piston body and the second piston body are connected by the connecting section, the diameter of the connecting section is smaller than the diameter of the first piston body, and the diameter of the first piston body is smaller than the diameter of the second piston body.

2. The hydraulic control system according to claim 1, characterized in that, The effective area of ​​the end face of the first piston body away from the connecting section is greater than the difference between the effective area of ​​the end face of the first piston body close to the connecting section and the effective area of ​​the end face of the second piston body close to the connecting section.

3. The hydraulic control system according to claim 2, characterized in that, The piston further includes a piston rod, which is connected to the side of the second piston body away from the first piston body and connected to the swashplate. The end of the first piston body away from the second piston body forms the first working chamber between itself and the first cylinder. The end of the second piston body close to the first piston body forms the second working chamber between itself and the second cylinder. The end of the second piston body away from the first piston body forms the spring chamber between itself and the second cylinder.

4. The hydraulic control system according to claim 3, characterized in that, The oil source includes a hydraulic pump, an accumulator, and an oil tank; the swashplate control valve includes a three-position five-way directional valve. The first working port of the three-position five-way directional valve is connected to the first working chamber, the second working port of the three-position five-way directional valve is connected to the second working chamber, the third and fourth working ports of the three-position five-way directional valve are both connected to the oil tank, the fifth working port of the three-position five-way directional valve is connected to the accumulator, and the accumulator is connected to the hydraulic pump.

5. The hydraulic control system according to claim 4, characterized in that, The three-position five-way directional valve has a first working position, a second working position, and a third working position. In the first working position, the first working oil port is connected to the fifth working oil port, while the second working oil port, the third working oil port, and the fourth working oil port are mutually blocked. In the second working position, the second working oil port is connected to the fifth working oil port, while the first working oil port, the third working oil port, and the fourth working oil port are mutually blocked. In the third working position, the first working port is connected to the third working port, the second working port is connected to the fourth working port, and the fifth working port is cut off from the first, second, third, and fourth working ports.

6. The hydraulic control system according to claim 4, characterized in that, The hydraulic control system also includes a rotary motor and a rotary control valve. The first oil inlet and return port of the rotary motor is connected to the rotary control valve through a first pipeline, and the second oil inlet and return port of the rotary motor is connected to the rotary control valve through a second pipeline. The rotary control valve is connected to the hydraulic pump and the oil tank. The rotary control valve is used to control the communication status between the first oil inlet and return port, the second oil inlet and return port, the hydraulic pump and the oil tank.

7. The hydraulic control system according to claim 6, characterized in that, The hydraulic control system also includes a relief valve, a first shut-off check valve, and a second shut-off check valve. The first pipeline is connected to the oil inlet of the overflow valve through the first shut-off check valve, the second pipeline is connected to the oil inlet of the overflow valve through the second shut-off check valve, and the oil outlet of the overflow valve is connected to the oil tank. It also includes a first replenishing check valve and a second replenishing check valve. The first pipeline is connected to the oil tank through the first replenishing check valve, and the second pipeline is connected to the oil tank through the second replenishing check valve.

8. The hydraulic control system according to claim 6, characterized in that, The hydraulic control system further includes a travel control valve, which is connected to the hydraulic pump, the oil tank and the travel motor, and is used to control the connection status of the travel motor, the hydraulic pump and the oil tank; The hydraulic control system further includes a rotary hand valve and a travel foot valve. The accumulator is connected to the rotary hand valve and the travel foot valve. The rotary hand valve is connected to the control port of the rotary control valve, and the travel foot valve is connected to the control port of the travel control valve.

9. The hydraulic control system according to claim 8, characterized in that, The hydraulic control system includes two sets of swashplate cylinders, swashplate control valves, travel motors, and travel control valves. One set of swashplate cylinders, swashplate control valves, travel motors, and travel control valves is used to drive the left travel device of the working machine, and the other set of swashplate cylinders, swashplate control valves, travel motors, and travel control valves is used to drive the right travel device of the working machine.

10. A type of operating machinery, characterized in that, Includes a hydraulic control system according to any one of claims 1 to 9.

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