Hydraulic control systems and operating machinery

Abstract

This invention relates to the field of hydraulic system technology, providing a hydraulic control system and a working machine. In the hydraulic control system, a hydraulic pump and an oil tank are connected to the track telescopic cylinder and the bulldozer blade cylinder via a control valve assembly. The control valve assembly can switch between a first functional position, a second functional position, and a third functional position. In the first functional position, the hydraulic pump drives the track telescopic cylinder; in the second functional position, the hydraulic pump drives the bulldozer blade cylinder; and in the third functional position, the oil tank can simultaneously communicate with both the rod-side and rodless-side chambers of the bulldozer blade cylinder. With this structural arrangement, the control valve assembly can switch between the first, second, and third functional positions to achieve the switching of track telescopic cylinder operation, bulldozer blade cylinder telescopic operation, and bulldozer blade floating state using the same control valve assembly. This saves the installation space occupied by the hydraulic control system and reduces costs.

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 essential pieces of machinery, equipped with tracks and a bulldozer blade on their undercarriage. During operation, the track extension and bulldozer blade working status need to be adjusted based on the working conditions. Most hydraulic control systems used to adjust these settings can only drive the extension and retraction of the track telescopic cylinders and the bulldozer blade cylinders. In practical applications, when a bulldozer blade floating function is required, it typically involves adding an extra control valve to the existing hydraulic control system to switch the floating function. This is costly, and the hydraulic control system occupies a significant amount of space. Summary of the Invention

[0003] This invention provides a hydraulic control system and a working machine to solve or improve the problems of high cost and large installation space required for adding a floating function to the bulldozer blade cylinder in existing hydraulic control systems.

[0004] According to a first aspect of the present invention, a hydraulic control system is provided, comprising a track telescopic cylinder, a bulldozer blade cylinder, a control valve assembly, a hydraulic pump, and an oil tank, wherein the hydraulic pump and the oil tank are connected to the track telescopic cylinder and the bulldozer blade cylinder via the control valve assembly.

[0005] The control valve assembly can switch between a first functional position, a second functional position, and a third functional position. In the first functional position, the hydraulic pump can drive the track telescopic cylinder to move; in the second functional position, the hydraulic pump can drive the bulldozer blade cylinder to move; in the third functional position, the oil tank can simultaneously communicate with both the rod-side chamber and the rodless chamber of the bulldozer blade cylinder.

[0006] According to a hydraulic control system provided by the present invention, the control valve group includes a function switching valve and a direction switching valve.

[0007] The hydraulic pump and the oil tank are connected to the direction switching valve. The direction switching valve is connected to the function switching valve. The function switching valve is connected to the track telescopic cylinder, the bulldozer blade cylinder, and the oil tank. The function switching valve can switch between a first function position, a second function position, and a third function position. The direction switching valve is used to control the extension and retraction direction of the track telescopic cylinder and the bulldozer blade cylinder when in the first function position or the second function position.

[0008] According to a hydraulic control system provided by the present invention, the directional switching valve includes a forward working position and a reverse working position.

[0009] In the forward working position, the hydraulic pump can drive the track telescopic cylinder to extend or retract, or drive the bulldozer blade cylinder to extend or retract; in the reverse working position, the hydraulic pump can drive the track telescopic cylinder to retract or extend, or drive the bulldozer blade cylinder to retract or extend.

[0010] According to a hydraulic control system provided by the present invention, the directional switching valve further includes a working stop position. In the working stop position, the hydraulic pump and the oil tank are both shut off from the track telescopic cylinder and the bulldozer blade cylinder via the directional switching valve.

[0011] According to a hydraulic control system provided by the present invention, the function switching valve is a three-position seven-way solenoid directional valve. The direction switching valve is a three-position four-way hydraulically controlled directional valve. The three-position seven-way solenoid directional valve includes a first port, a second port, a third port, a fourth port, a fifth port, a sixth port, and a seventh port. The three-position four-way hydraulically controlled directional valve includes an eighth port, a ninth port, a tenth port, and an eleventh port.

[0012] The first oil port is connected to the rod-side chamber of the track telescopic cylinder. The second oil port is connected to the rodless chamber of the track telescopic cylinder. The third oil port is connected to the rodless chamber of the bulldozer blade cylinder. The fourth oil port is connected to the rod-side chamber of the bulldozer blade cylinder. The fifth oil port is connected to the eighth oil port. The sixth oil port is connected to the ninth oil port. The seventh oil port is connected to the oil tank. The tenth oil port is connected to the hydraulic pump. The eleventh oil port is connected to the oil tank.

[0013] According to a hydraulic control system provided by the present invention, in the first functional position, the first oil port is connected to the fifth oil port, and the second oil port is connected to the sixth oil port; in the second functional position, the third oil port is connected to the fifth oil port, and the fourth oil port is connected to the sixth oil port; in the third functional position, both the third oil port and the fourth oil port are connected to the seventh oil port.

[0014] According to a hydraulic control system provided by the present invention, in the forward working position, the eighth oil port is connected to the tenth oil port, and the ninth oil port is connected to the eleventh oil port; in the reverse working position, the eighth oil port is connected to the eleventh oil port, and the ninth oil port is connected to the tenth oil port; in the working stop position, the eighth oil port, the ninth oil port, the tenth oil port, and the eleventh oil port are mutually cut off.

[0015] According to a hydraulic control system provided by the present invention, the hydraulic control system further includes a control device. The control device is connected to the left control terminal and the right control terminal of the function switching valve. The control device is used to switch the operating position of the function switching valve. Furthermore, when there is no control signal at either the left or right control terminal of the function switching valve, the function switching valve remains in the second functional position.

[0016] According to a hydraulic control system provided by the present invention, the control device is connected to the left and right control terminals of the directional switching valve. The control device is used to control the working position of the directional switching valve. Furthermore, when there is no control signal at either the left or right control terminal of the directional switching valve, the directional switching valve remains in the working off position.

[0017] A second aspect of the present invention provides a working machine, including tracks, a bulldozer blade, and a hydraulic control system as described above. The tracks are connected to track extension cylinders. The bulldozer blade is connected to a bulldozer blade cylinder.

[0018] The hydraulic control system provided by this invention includes a track telescopic cylinder, a bulldozer blade cylinder, a control valve assembly, a hydraulic pump, and an oil tank. The hydraulic pump and oil tank are connected to the track telescopic cylinder and the bulldozer blade cylinder via the control valve assembly. The control valve assembly can switch between a first functional position, a second functional position, and a third functional position. In the first functional position, the hydraulic pump drives the track telescopic cylinder. In the second functional position, the hydraulic pump drives the bulldozer blade cylinder. In the third functional position, both the rod-side chamber and the rodless chamber of the bulldozer blade cylinder are simultaneously connected to the oil tank via the control valve assembly.

[0019] Specifically, when adjusting the track extension of the working machinery, the control valve group is switched to the first function position. The hydraulic pump supplies oil to the rod-side or rodless chamber of the track extension cylinder through the control valve group. The oil in the rod-side or rodless chamber of the track extension cylinder flows back to the oil tank through the control valve group, causing the piston rod of the track extension cylinder to retract or extend. When adjusting the working position of the bulldozer blade cylinder, the control valve group is switched to the second function position. The hydraulic pump supplies oil to the rod-side or rodless chamber of the bulldozer blade cylinder through the control valve group. The oil in the rod-side or rod-side chamber of the bulldozer blade cylinder flows back to the oil tank, causing the piston rod of the bulldozer blade cylinder to retract or extend. In special operating conditions such as snow removal, the control valve group is switched to the third function position. The rod-side and rodless chambers of the bulldozer blade cylinder are simultaneously connected to the oil tank through the control valve group. The bulldozer blade cylinder switches to a floating state and drives the bulldozer blade to float.

[0020] This structural design allows for the installation of control valve assemblies within the hydraulic control system. These assemblies can switch between first, second, and third functional positions, enabling the same control valve assembly to switch between functions such as track extension cylinder actuation, bulldozer blade extension cylinder actuation, and bulldozer blade floating state. This saves space and reduces costs associated with the hydraulic control system.

[0021] 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

[0022] To more clearly illustrate the technical solutions in this invention or related technologies, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a system schematic diagram of the hydraulic control system provided by the present invention;

[0024] Figure 2 This is a schematic diagram of the control valve group in the hydraulic control system provided by the present invention;

[0025] Figure label:

[0026] 100. Track telescopic cylinder; 200. Bulldozer blade cylinder; 300. Control valve assembly; 310. Function switching valve; 311. First function position; 312. Second function position; 313. Third function position; 320. Direction switching valve; 321. Forward working position; 322. Reverse working position; 323. Working stop position; 400. Hydraulic pump; 500. Oil tank; 600. Safety valve; 700. Control device. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0028] In the description of the embodiments of the present invention, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "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," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] 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.

[0030] 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," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply 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 that the first feature is at a lower horizontal level than the second feature.

[0031] In the description of this specification, the references to terms such as "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. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0032] The following is combined with Figure 1 and Figure 2This invention describes a hydraulic control system and a working machine. 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.

[0033] An embodiment of the first aspect of the present invention provides a hydraulic control system, such as Figure 1 and Figure 2 As shown, the system includes a track telescopic cylinder 100, a bulldozer blade cylinder 200, a control valve assembly 300, a hydraulic pump 400, and an oil tank 500. The hydraulic pump 400 and the oil tank 500 are connected to the track telescopic cylinder 100 and the bulldozer blade cylinder 200 via the control valve assembly 300.

[0034] The control valve assembly 300 can switch between a first functional position 311, a second functional position 312, and a third functional position 313. In the first functional position 311, the hydraulic pump 400 can drive the track telescopic cylinder 100 to operate; in the second functional position 312, the hydraulic pump 400 can drive the bulldozer blade cylinder 200 to operate; in the third functional position 313, the oil tank 500 can simultaneously communicate with both the rod-side chamber and the rodless chamber of the bulldozer blade cylinder 200.

[0035] The hydraulic control system provided by this invention includes a track telescopic cylinder 100, a bulldozer blade cylinder 200, a control valve assembly 300, a hydraulic pump 400, and an oil tank 500. The hydraulic pump 400 and the oil tank 500 are connected to the track telescopic cylinder 100 and the bulldozer blade cylinder 200 via the control valve assembly 300. The control valve assembly 300 can switch between a first functional position 311, a second functional position 312, and a third functional position 313. In the first functional position 311, the hydraulic pump 400 drives the track telescopic cylinder 100. In the second functional position 312, the hydraulic pump 400 drives the bulldozer blade cylinder 200. In the third functional position 313, both the rod-side chamber and the rodless chamber of the bulldozer blade cylinder 200 are simultaneously connected to the oil tank 500 via the control valve assembly 300.

[0036] Specifically, when it is necessary to adjust the track extension of the working machinery, the control valve group 300 is switched to the first function position 311. The hydraulic pump 400 supplies oil to the rod-side or rodless chamber of the track telescopic cylinder 100 through the control valve group 300. The oil in the rodless or rod-side chamber of the track telescopic cylinder 100 flows back to the oil tank 500 through the control valve group 300, causing the piston rod of the track telescopic cylinder 100 to retract or extend. When it is necessary to adjust the working position of the bulldozer blade cylinder 200, the control valve group 300 is switched to the second function position 312. The hydraulic pump 400 supplies oil to the rod-side or rodless chamber of the bulldozer blade cylinder 200 through the control valve group 300. The oil in the rodless or rod-side chamber of the bulldozer blade cylinder 200 flows back to the oil tank 500, causing the piston rod of the bulldozer blade cylinder 200 to retract or extend. In special operating conditions such as snow removal, the control valve group 300 is switched to the third function position 313. The rod chamber and rodless chamber of the bulldozer blade cylinder 200 are simultaneously connected to the oil tank 500 through the control valve group 300. The bulldozer blade cylinder 200 is switched to the floating state and drives the bulldozer blade to float.

[0037] With this structural arrangement, a control valve group 300 is installed in the hydraulic control system. The control valve group 300 can switch between a first functional position 311, a second functional position 312, and a third functional position 313, so that the same control valve group 300 can be used to switch between the functions of the track telescopic cylinder 100, the telescopic movement of the bulldozer blade cylinder 200, and the floating state of the bulldozer blade. This saves the installation space occupied by the hydraulic control system and reduces costs.

[0038] In one embodiment of the present invention, the control valve assembly 300 includes a function switching valve 310 and a direction switching valve 320.

[0039] The hydraulic pump 400 and oil tank 500 are connected to the directional switching valve 320. The directional switching valve 320 is connected to the function switching valve 310. The function switching valve 310 is connected to the track telescopic cylinder 100, the bulldozer blade cylinder 200, and the oil tank 500. The function switching valve 310 can switch between a first function position 311, a second function position 312, and a third function position 313. The directional switching valve 320 is used to control the telescopic direction of the track telescopic cylinder 100 and the bulldozer blade cylinder 200 when in the first function position 311 or the second function position 312.

[0040] Furthermore, in one embodiment of the present invention, the direction switching valve 320 includes a forward working position 321 and a reverse working position 322.

[0041] In the forward working position 321, the hydraulic pump 400 can drive the track telescopic cylinder 100 to extend or retract, or drive the bulldozer blade cylinder 200 to extend or retract; in the reverse working position 322, the hydraulic pump 400 can drive the track telescopic cylinder 100 to retract or extend, or drive the bulldozer blade cylinder 200 to retract or extend.

[0042] For example, such as Figure 1 and Figure 2 As shown, the inlet of the hydraulic pump 400 is connected to the oil tank 500, and the outlet of the hydraulic pump 400 and the oil tank 500 are connected to the directional switching valve 320. The directional switching valve 320 is connected to the function switching valve 310. The function switching valve 310 is connected to the oil tank 500, the track telescopic cylinder 100, and the bulldozer blade cylinder 200. When the directional switching valve 320 is in the forward working position 321 and the reverse working position 322, the movement direction of the piston rods of the track telescopic cylinder 100 and the bulldozer blade cylinder 200 can be determined according to actual needs. In this embodiment, the forward working position 321 of the directional switching valve 320 is used to control the retraction of the piston rod of the track telescopic cylinder 100 and the extension of the piston rod of the bulldozer blade cylinder 200. The reverse working position 322 of the directional switching valve 320 is used to control the extension of the piston rod of the track telescopic cylinder 100 and the retraction of the piston rod of the bulldozer blade cylinder 200.

[0043] During operation, when the function switching valve 310 switches to the first function position 311 and the direction switching valve 320 switches to the forward working position 321, the oil output by the hydraulic pump 400 enters the rod chamber of the track telescopic cylinder 100 through the direction switching valve 320 and the function switching valve 310. The oil in the rodless chamber of the track telescopic cylinder 100 flows back to the oil tank 500 through the function switching valve 310 and the direction switching valve 320, and the piston rod of the track telescopic cylinder 100 retracts.

[0044] When the function switching valve 310 is switched to the first function position 311 and the direction switching valve 320 is switched to the reverse working position 322, the oil output by the hydraulic pump 400 enters the rodless chamber of the track telescopic cylinder 100 through the direction switching valve 320 and the function switching valve 310. The oil in the rod chamber of the track telescopic cylinder 100 flows back to the oil tank 500 through the function switching valve 310 and the direction switching valve 320, and the piston rod of the track telescopic cylinder 100 extends.

[0045] Similarly, when the function switching valve 310 is switched to the second function position 312 and the direction switching valve 320 is switched to the forward working position 321, the oil output by the hydraulic pump 400 enters the rodless chamber of the bulldozer cylinder 200 through the direction switching valve 320 and the function switching valve 310. The oil in the rod chamber of the bulldozer cylinder 200 flows back to the oil tank 500 through the function switching valve 310 and the direction switching valve 320, and the piston rod of the bulldozer cylinder 200 extends.

[0046] When the function switching valve 310 switches to the second function position 312 and the direction switching valve 320 switches to the reverse working position 322, the oil output by the hydraulic pump 400 enters the rod chamber of the bulldozer blade retraction cylinder through the direction switching valve 320 and the function switching valve 310. The oil in the rodless chamber of the bulldozer blade cylinder 200 flows back to the oil tank 500 through the function switching valve 310 and the direction switching valve 320, and the piston rod of the bulldozer blade cylinder 200 retracts.

[0047] When the function switching valve 310 is switched to the third function position 313, both the rod chamber and the rodless chamber of the bulldozer blade cylinder 200 are directly connected to the oil tank 500 through the function switching valve 310. At this time, the working state of the direction switching valve 320 does not affect the floating function of the bulldozer blade.

[0048] In one embodiment of the present invention, such as Figure 1 and Figure 2 As shown, the directional switching valve 320 also includes a working stop position 323. In the working stop position 323 state, the hydraulic pump 400 and oil tank 500 are all shut off from the track telescopic cylinder 100 and the bulldozer blade cylinder 200 through the directional switching valve 320.

[0049] In other words, when the directional switching valve 320 is in the working cut-off position 323, both the track telescopic cylinder 100 and the bulldozer blade cylinder 200 are disconnected from the power source hydraulic pump 400. In other words, when the directional switching valve 320 is in the working cut-off position 323, the hydraulic fluid output by the hydraulic pump 400 cannot be supplied to the track telescopic cylinder 100 and the bulldozer blade cylinder 200, thus preventing them from performing telescopic movements. In this state, the bulldozer blade cylinder 200 can only be kept in a floating state by controlling the function switching valve 310. With this structural design, even if the directional switching valve 320 is faulty, it does not affect the switching of the bulldozer blade cylinder 200's floating state; the function switching valve 310 can be switched to the third function position 313 when needed.

[0050] In one embodiment of the present invention, such as Figure 1 and Figure 2As shown, the function switching valve 310 is a three-position seven-way solenoid directional valve. The directional switching valve 320 is a three-position four-way hydraulic directional valve. The three-position seven-way solenoid directional valve includes a first port, a second port, a third port, a fourth port, a fifth port, a sixth port, and a seventh port. The three-position four-way hydraulic directional valve includes an eighth port, a ninth port, a tenth port, and an eleventh port.

[0051] The first oil port is connected to the rod-side chamber of the track telescopic cylinder 100. The second oil port is connected to the rodless chamber of the track telescopic cylinder 100. The third oil port is connected to the rodless chamber of the bulldozer blade cylinder 200. The fourth oil port is connected to the rod-side chamber of the bulldozer blade cylinder 200. The fifth oil port is connected to the eighth oil port. The sixth oil port is connected to the ninth oil port. The seventh oil port is connected to the oil tank 500. The tenth oil port is connected to the hydraulic pump 400. The eleventh oil port is connected to the oil tank 500.

[0052] In one embodiment of the present invention, in the state of the first functional position 311, the first oil port is connected to the fifth oil port, and the second oil port is connected to the sixth oil port. In the state of the second functional position 312, the third oil port is connected to the fifth oil port, and the fourth oil port is connected to the sixth oil port. In the state of the third functional position 313, both the third oil port and the fourth oil port are connected to the seventh oil port.

[0053] Furthermore, in one embodiment of the present invention, in the forward working position 321, the eighth oil port is connected to the tenth oil port, and the ninth oil port is connected to the eleventh oil port; in the reverse working position 322, the eighth oil port is connected to the eleventh oil port, and the ninth oil port is connected to the tenth oil port; in the working stop position 323, the eighth oil port, the ninth oil port, the tenth oil port and the eleventh oil port are mutually cut off.

[0054] It should be noted that the above embodiments are merely illustrative examples of the present invention and do not constitute any limitation on the present invention. That is to say, the specific type of the function switching valve 310 is not limited to a three-position seven-way solenoid directional valve, and the specific type of the direction switching valve 320 is not limited to a three-position four-way hydraulic directional valve.

[0055] In one embodiment of the present invention, the hydraulic control system further includes a control device 700. The control device 700 is connected to the left control terminal and the right control terminal of the function switching valve 310. The control device 700 is used to switch the operating position of the function switching valve 310. And when there is no control signal at either the left control terminal or the right control terminal of the function switching valve 310, the function switching valve 310 remains in the second functional position 312.

[0056] Furthermore, in one embodiment of the present invention, the control device 700 is connected to the left control terminal and the right control terminal of the directional switching valve 320. The control device 700 is used to control the operating position of the directional switching valve 320. And when there is no control signal at either the left control terminal or the right control terminal of the directional switching valve 320, the directional switching valve 320 remains in the operating off position 323.

[0057] For example, such as Figure 1 and Figure 2 As shown, the left position of the function switching valve 310 is the first function position 311, the middle position is the second function position 312, and the right position is the third function position 313. The right position of the directional switching valve 320 is the forward working position 321, the middle position is the working stop position 323, and the left position is the reverse working position 322. The left end of the function switching valve 310 is provided with a left control terminal, and the right end is provided with a right control terminal. The left end of the directional switching valve 320 is provided with a left control terminal, and the right end is provided with a right control terminal. In this embodiment, the control terminal of the function switching valve 310 is an electrically controlled terminal, and the control terminal of the directional switching valve 320 is a hydraulically controlled terminal.

[0058] The hydraulic control system also includes control buttons, including a forward action button, a reverse action button, an oil supply cut-off button, a track action button, and a bulldozer blade float button. These buttons are connected to the control device 700. The forward action button controls the control device 700 to supply control oil to the right control end of the directional switching valve 320, causing the directional switching valve 320 to switch to the forward working position 321. The reverse action button controls the control device 700 to supply control oil to the left control end of the directional switching valve 320, causing the directional switching valve 320 to switch to the reverse working position 322. The oil supply cut-off button controls the device 700 to simultaneously cut off the control oil flow to both the left and right control ends of the directional switching valve 320, causing the directional switching valve 320 to switch to the working cut-off position 323. The track action button controls the control device 700 to send an electrical signal to the left control terminal of the function switching valve 310, so that the function switching valve 310 switches to the first function position 311. The bulldozer blade float button controls the control device 700 to send an electrical signal to the right control terminal of the function switching valve 310, so that the function switching valve 310 switches to the second function position 312.

[0059] It is important to emphasize that in this hydraulic control system, there is no need for a separate control button to switch the function switching valve 310 to the second function position 312. When both the track action button and the bulldozer blade float button are in the released state, there is no electrical signal at either the left or right control end of the function switching valve 310. The function switching valve 310 can naturally remain in the neutral position, i.e., the second function position 312. The second function position 312 is the commonly used working position during operation. This structural design not only improves the ease of operation for workers but also saves costs.

[0060] In addition, a safety valve 600 is installed between the oil outlet of the hydraulic pump 400 and the oil tank 500 to ensure the safety of the hydraulic control system.

[0061] A second aspect of the present invention provides a working machine, including tracks, a bulldozer blade, and a hydraulic control system as described above. The tracks are connected to a track telescopic cylinder 100, and the bulldozer blade is connected to a bulldozer blade cylinder 200.

[0062] For example, in one embodiment of the present invention, the above-mentioned operating machinery includes an excavator.

[0063] It should be noted 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 aforementioned operating machinery includes, but is not limited to, excavators. In other embodiments of the present invention, the aforementioned operating machinery may also include loaders, etc.

[0064] Furthermore, the working machinery provided by the present invention, since it includes the hydraulic control system described above, also possesses the advantages described above.

[0065] 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, It includes a track telescopic cylinder, a bulldozer blade cylinder, a control valve assembly, a hydraulic pump, and an oil tank. The hydraulic pump and the oil tank are connected to the track telescopic cylinder and the bulldozer blade cylinder through the control valve assembly. The control valve group can switch between a first functional position, a second functional position, and a third functional position. In the first functional position, the hydraulic pump can drive the track telescopic cylinder to move. In the second functional position, the hydraulic pump can drive the bulldozer blade cylinder to move. In the third functional position, the oil tank can simultaneously communicate with both the rod-side chamber and the rodless chamber of the bulldozer blade cylinder. The same control valve group can be used to switch between the track telescopic cylinder action, the bulldozer blade cylinder telescopic action, and the bulldozer blade floating state. The control valve group includes a function switching valve and a direction switching valve. The function switching valve can switch between the first function position, the second function position and the third function position. The direction switching valve is used to control the extension and retraction direction of the track telescopic cylinder and the bulldozer blade cylinder in the state of the first function position or the second function position. The directional switching valve includes a forward operating position and a reverse operating position. In the positive working position, the hydraulic pump can drive the track telescopic cylinder to extend or retract, or drive the bulldozer blade cylinder to extend or retract. In the reverse working position, the hydraulic pump can drive the track telescopic cylinder to retract or extend, or drive the bulldozer blade cylinder to retract or extend.

2. The hydraulic control system according to claim 1, characterized in that, in, The hydraulic pump and the oil tank are connected to the direction switching valve, the direction switching valve is connected to the function switching valve, and the function switching valve is connected to the track telescopic cylinder, the bulldozer blade cylinder, and the oil tank.

3. The hydraulic control system according to claim 1, characterized in that, The directional switching valve also includes a working stop position. In the working stop position, the hydraulic pump and the oil tank are all shut off from the track telescopic cylinder and the bulldozer blade cylinder through the directional switching valve.

4. The hydraulic control system according to claim 3, characterized in that, The function switching valve is a three-position seven-way solenoid directional valve, and the direction switching valve is a three-position four-way hydraulic directional valve. The three-position seven-way solenoid directional valve includes a first port, a second port, a third port, a fourth port, a fifth port, a sixth port, and a seventh port. The three-position four-way hydraulic directional valve includes an eighth port, a ninth port, a tenth port, and an eleventh port. The first oil port is connected to the rod chamber of the track telescopic cylinder, the second oil port is connected to the rodless chamber of the track telescopic cylinder, the third oil port is connected to the rodless chamber of the bulldozer blade cylinder, the fourth oil port is connected to the rod chamber of the bulldozer blade cylinder, the fifth oil port is connected to the eighth oil port, the sixth oil port is connected to the ninth oil port, the seventh oil port is connected to the oil tank, the tenth oil port is connected to the hydraulic pump, and the eleventh oil port is connected to the oil tank.

5. The hydraulic control system according to claim 4, characterized in that, In the state of the first function position, the first oil port is connected to the fifth oil port, and the second oil port is connected to the sixth oil port; in the state of the second function position, the third oil port is connected to the fifth oil port, and the fourth oil port is connected to the sixth oil port; in the state of the third function position, both the third oil port and the fourth oil port are connected to the seventh oil port.

6. The hydraulic control system according to claim 5, characterized in that, In the forward working position, the eighth oil port is connected to the tenth oil port, and the ninth oil port is connected to the eleventh oil port; in the reverse working position, the eighth oil port is connected to the eleventh oil port, and the ninth oil port is connected to the tenth oil port; in the working stop position, the eighth oil port, the ninth oil port, the tenth oil port, and the eleventh oil port are mutually cut off.

7. The hydraulic control system according to claim 6, characterized in that, The hydraulic control system further includes a control device connected to the left and right control terminals of the function switching valve. The control device is used to switch the working position of the function switching valve, and when there is no control signal at either the left or right control terminal of the function switching valve, the function switching valve remains in the second function position.

8. The hydraulic control system according to claim 7, characterized in that, The control device is connected to the left and right control terminals of the directional switching valve. The control device is used to control the working position of the directional switching valve, and the directional switching valve remains in the working cut-off position when there is no control signal at either the left or right control terminal of the directional switching valve.

9. A type of operating machinery, characterized in that, The system includes tracks, a bulldozer blade, and a hydraulic control system according to any one of claims 1 to 8, wherein the tracks are connected to the track telescopic cylinder, and the bulldozer blade is connected to the bulldozer blade cylinder.

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