CN219549241U - Hydraulic system and engineering vehicle - Google Patents
Hydraulic system and engineering vehicle Download PDFInfo
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- CN219549241U CN219549241U CN202320813557.1U CN202320813557U CN219549241U CN 219549241 U CN219549241 U CN 219549241U CN 202320813557 U CN202320813557 U CN 202320813557U CN 219549241 U CN219549241 U CN 219549241U
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Abstract
The utility model relates to the technical field of engineering vehicles, and discloses a hydraulic system and an engineering vehicle, wherein a first pilot hydraulic control end is connected with a pilot hydraulic control end of a back pressure valve. The pilot control valve acts to enable the oil supply oil way to be communicated with the first hydraulic control pilot end, when the second hydraulic control pilot end is communicated with the oil tank, the oil pressure of the first hydraulic control pilot end is increased, the state of the main control valve is gradually switched, and the oil pressure of the hydraulic control end of the back pressure valve is gradually increased. The oil supply way is conducted with the second hydraulic control pilot end through the action of the pilot control valve, when the first hydraulic control pilot end is conducted with the oil tank, the oil pressure of the second hydraulic control pilot end is reduced, the state of the main control valve is gradually switched, the oil pressure of the hydraulic control end of the back pressure valve is gradually reduced along with the state of the main control valve, the purpose of adjusting the oil return back pressure is achieved, the adjustment requirement of the oil return back pressure is met, the oil return back pressure can be adjusted according to the state change of the main control valve, an electromagnetic back pressure valve does not need to be independently arranged, and the cost of a hydraulic system is reduced.
Description
Technical Field
The utility model relates to the technical field of engineering vehicles, in particular to a hydraulic system and an engineering vehicle.
Background
In order to adjust the oil return speed, a back pressure valve is arranged on an oil return oil path of the hydraulic system, and a throttle valve is generally adopted as the back pressure valve to adjust the oil return back pressure. Specifically, return spring of back pressure valve is utilized to provide the oil return back pressure, and oil return pressure is not adjustable, can't adapt to the regulation demand of oil return back pressure under different operating modes.
Therefore, the prior art proposes to use an electromagnetic back pressure valve with an adjustable opening degree, and the purpose of adjusting the opening degree of the electromagnetic back pressure valve is achieved by adjusting the current of the electromagnetic back pressure valve, so that the adjustment of the oil return back pressure is realized. But the engineering vehicle vibrates greatly in the engineering process, the electromagnetic back pressure valve is extremely easy to cause circuit wiring faults, and the electromagnetic back pressure valve is powered off, so that the opening degree of the electromagnetic back pressure valve is not adjustable.
In addition, the opening degree of the electromagnetic back pressure valve is correspondingly regulated according to the state of the main control valve, and an associated control strategy between the opening degree regulation of the electromagnetic back pressure valve and the state regulation of the main control valve is required to be designed, so that the cost of the hydraulic system is increased.
Therefore, a hydraulic system is needed to solve the above technical problems.
Disclosure of Invention
The utility model aims to provide a hydraulic system and an engineering vehicle, which not only can meet the back pressure regulation requirement of an oil return way of the engineering vehicle, but also can realize that an electromagnetic back pressure valve automatically regulates the opening according to the state of a main control valve, and reduce the cost of the hydraulic system.
To achieve the object, in a first aspect, the present utility model adopts the following technical scheme:
a hydraulic system, comprising:
an oil supply circuit and an oil tank;
the main control valve is a hydraulic control valve and is provided with an oil return port and two hydraulic control pilot ends, and the oil return port is connected with the oil tank through an oil return oil way;
the back pressure valve is a hydraulic control valve, the back pressure valve is arranged on the oil return oil path, and the hydraulic control end of the back pressure valve is connected with one of the hydraulic control pilot ends through a pressure regulating oil path;
and one of the two pilot control ends is communicated with the oil tank, and the other pilot control end is communicated with the oil supply oil path.
As a preferable technical scheme of the hydraulic system, the hydraulic system further comprises a first pilot oil path and an electromagnetic pressure regulating valve, wherein the first pilot oil path is connected with a hydraulic control end of the back pressure valve, and the electromagnetic pressure regulating valve is arranged on the first pilot oil path; and a stop valve is arranged on the pressure regulating oil way.
As a preferable technical scheme of the hydraulic system, the hydraulic system further comprises a pilot oil pump, an oil outlet of the pilot oil pump is connected with the first pilot oil path, and an oil inlet of the pilot oil pump is connected with the oil tank.
As a preferable technical scheme of the hydraulic system, the first pilot oil path is communicated with the oil tank through a pressure relief valve.
As a preferable technical scheme of the hydraulic system, the hydraulic system further comprises a second pilot oil path and a pressure regulating valve, wherein the second pilot oil path is connected with the hydraulic control end of the back pressure valve, and the pressure regulating valve is arranged on the second pilot oil path; and a stop valve is arranged on the pressure regulating oil way.
As a preferable technical scheme of the hydraulic system, the pressure regulating valve is a two-position three-way electromagnetic reversing valve, and the pressure regulating valve can enable the hydraulic control end of the back pressure valve to be communicated with the oil tank.
As a preferable technical scheme of the hydraulic system, a one-way throttle valve is arranged on a connecting oil path between the pilot control valve and the pilot control end.
As a preferable technical scheme of the hydraulic system, the two pilot-controlled ends of the main control valve are a first pilot-controlled end and a second pilot-controlled end respectively, and the first pilot-controlled end is connected with the pilot-controlled end of the back pressure valve;
the hydraulic system further comprises an oil cylinder, the master control valve is provided with a first working position and a second working position, the pilot control valve enables the first pilot hydraulic end and the pilot hydraulic end of the back pressure valve to be communicated with the oil tank, the pilot control valve enables the master control valve to be in the first working position when the second pilot hydraulic end is communicated with the oil supply oil way, the master control valve enables a rodless cavity of the oil cylinder to be communicated with the oil supply oil way, and enables a rod cavity of the oil cylinder to be communicated with an inlet of the back pressure valve;
the pilot control valve enables the first pilot control end and the hydraulic control end of the back pressure valve to be communicated with the oil supply oil way, and when the second pilot control end is communicated with the oil tank, the main control valve is in the second working position, the main control valve enables the rodless cavity of the oil cylinder to be communicated with the inlet of the back pressure valve, and enables the rod cavity of the oil cylinder to be communicated with the oil supply oil way.
In order to achieve the above object, in a second aspect, the present utility model further provides an engineering vehicle, including a cab, and the hydraulic system according to any one of the above aspects, wherein a pilot handle is disposed in the cab, and the pilot handle is used for adjusting a state of the pilot control valve.
As a preferable technical scheme of the engineering vehicle, the hydraulic system further comprises a first pilot oil path and an electromagnetic pressure regulating valve, wherein the first pilot oil path is connected with the hydraulic control end of the back pressure valve, and the electromagnetic pressure regulating valve is arranged on the first pilot oil path; a stop valve is arranged on the pressure regulating oil way; a first manual operation part is arranged in the cab and used for adjusting the opening degree of an electromagnetic pressure regulating valve of the hydraulic system; the stop valve of the hydraulic system is a manual switch valve arranged in the cab;
the hydraulic system further comprises a second pilot oil path and a pressure regulating valve, wherein the second pilot oil path is communicated with the hydraulic control end of the back pressure valve through the pressure regulating valve; and a second manual operation part is further arranged in the cab and used for adjusting the opening degree of a pressure regulating valve of the hydraulic system.
The utility model has the beneficial effects that: according to the hydraulic system and the engineering vehicle provided by the utility model, the first pilot-controlled end is connected with the pilot-controlled end of the back pressure valve. When the pilot control valve acts to enable the oil supply oil way to be communicated with the first hydraulic control pilot end and the second hydraulic control pilot end to be communicated with the oil tank, the oil pressure of the first hydraulic control pilot end is increased, the state of the main control valve is gradually switched, and meanwhile, the oil pressure of the hydraulic control end of the back pressure valve is gradually increased due to the fact that the first hydraulic control pilot end is communicated with the hydraulic control end of the back pressure valve. The oil supply way is conducted with the second hydraulic control pilot end through the action of the pilot control valve, when the first hydraulic control pilot end is conducted with the oil tank, the oil pressure of the second hydraulic control pilot end is reduced, the state of the main control valve is gradually switched, meanwhile, the oil pressure of the hydraulic control end of the back pressure valve is gradually reduced due to the conduction of the first hydraulic control pilot end and the hydraulic control end of the back pressure valve, the purpose of adjusting the oil return back pressure is achieved, the adjustment requirement of the oil return back pressure is met, the oil return back pressure can be adjusted according to the state change of the main control valve, the electromagnetic back pressure valve can be not required to be independently arranged, and the cost of a hydraulic system is reduced.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following description will briefly explain the drawings needed in the description of the embodiments of the present utility model, and it is obvious that the drawings in the following description are only some embodiments of the present utility model, and other drawings may be obtained according to the contents of the embodiments of the present utility model and these drawings without inventive effort for those skilled in the art.
Fig. 1 is a schematic diagram of a hydraulic system provided by an embodiment of the present utility model.
In the figure:
1. an oil supply path; 2. a main control valve; 21. a first pilot-operated end; 22. a second pilot-controlled pilot end; 3. an oil return path; 4. a back pressure valve; 5. pressure regulating oil way; 6. a stop valve; 7. an electromagnetic pressure regulating valve; 8. an oil cylinder; 9. a one-way throttle valve; 10. a first pilot oil passage; 11. and a second pilot oil passage.
Detailed Description
The utility model is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the utility model and are not limiting thereof. It should be further noted that, for convenience of description, only some, but not all of the structures related to the present utility model are shown in the drawings.
In the description of the present utility model, unless explicitly stated and limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.
In the present utility model, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.
In the description of the present embodiment, the terms "upper", "lower", "right", etc. orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are merely for convenience of description and simplicity of operation, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the utility model. Furthermore, the terms "first," "second," and the like, are used merely for distinguishing between descriptions and not for distinguishing between them.
The embodiment provides a hydraulic system and an engineering vehicle, wherein the engineering vehicle comprises the hydraulic system, the engineering vehicle can be a bulldozer, an excavator and the like, the hydraulic system can meet the back pressure regulation requirement of an oil return path of the engineering vehicle, and the problem that once the electromagnetic back pressure valve is damaged when the electromagnetic back pressure valve is singly adopted to regulate the back pressure, the back pressure of the oil return cannot be regulated is solved; meanwhile, the electromagnetic back pressure valve can automatically adjust the opening according to the state of the main control valve, and the cost of the hydraulic system is reduced.
As shown in fig. 1, the hydraulic system comprises an oil supply path 1, an oil tank, a main control valve 2, a back pressure valve 4 and a pilot control valve, wherein the main control valve 2 is a hydraulic control valve, the main control valve 2 is provided with an oil return port and two hydraulic control pilot ends, and the oil return port is connected with the oil tank through an oil return path 3; the back pressure valve 4 is a hydraulic control one-way valve, the back pressure valve 4 is arranged on the oil return path 3, and the hydraulic control end of the back pressure valve 4 is connected with one of the hydraulic control pilot ends; the pilot control valve can lead one of the two hydraulic control pilot ends to be communicated with the oil tank, and the other hydraulic control pilot end to be communicated with the oil supply oil way 1. Illustratively, the port T in fig. 1 is used for connecting to a tank, and the port P in fig. 1 is used for connecting to a working oil pump.
The two pilot-operated ends are respectively denoted as a first pilot-operated end 21 and a second pilot-operated end 22, wherein the first pilot-operated end 21 is connected with the pilot-operated end of the back pressure valve 4. Illustratively, the first pilot-controlled pilot port 21 is connected to the pilot control valve through the PstB port in fig. 1, and the second pilot-controlled pilot port 22 is connected to the pilot control valve through the PstA port in fig. 1.
When the pilot control valve acts to conduct the oil supply path 1 with the first pilot control end 21 and the second pilot control end 22 with the oil tank, the oil pressure of the first pilot control end 21 increases, the state of the main control valve 2 is gradually switched, and meanwhile, the oil pressure of the pilot control end of the back pressure valve 4 also gradually increases due to the conduction of the first pilot control end 21 with the pilot control end of the back pressure valve 4. When the pilot control valve acts to enable the oil supply oil way 1 to be conducted with the second pilot control end 22, and the first pilot control end 21 is conducted with the oil tank, the oil pressure of the second pilot control end 22 is reduced, the state of the main control valve 2 is gradually switched, meanwhile, the oil pressure of the pilot control end of the back pressure valve 4 is gradually reduced due to the fact that the pilot control end 21 is conducted with the pilot control end of the back pressure valve 4, accordingly the purpose of adjusting the oil return back pressure is achieved, the adjustment requirement of the oil return back pressure is met, the oil return back pressure can be adjusted according to the state change of the main control valve 2, the electromagnetic back pressure valve 4 can be not independently arranged, and the cost of a hydraulic system is reduced.
Specifically, the main control valve 2 is a three-position seven-way reversing valve, the main control valve 2 is provided with two working oil ports, such as an oil port A and an oil port B in the figure 1, the engineering vehicle further comprises working components, such as an oil cylinder 8, a motor and the like, the working components are taken as the oil cylinder 8 as an example, the two working oil ports are respectively connected with a rod cavity and a rodless cavity of the oil cylinder 8, and the extending, retracting or keeping the state of a piston rod of the oil cylinder 8 unchanged is realized by controlling the state change of the main control valve 2.
The main control valve 2 has three working positions, namely a first working position, a second working position and a third working position, the pilot control valve acts to enable the first pilot control end 21 and the pilot control end of the back pressure valve 4 to be communicated with the oil tank, and enable the second pilot control end 22 to be communicated with the oil supply oil path 1, and when the main control valve 2 is switched to the first working position (the left position in fig. 1), the main control valve 2 enables the rodless cavity of the oil cylinder 8 to be communicated with the oil supply oil path 1, and enables the rod cavity of the oil cylinder 8 to be communicated with the inlet of the back pressure valve 4. Specifically, the rodless cavity of the oil cylinder 8 is used for oil feeding, the rod cavity of the oil cylinder 8 is used for oil return, at the moment, the first hydraulic control pilot end 21 and the hydraulic control end of the back pressure valve 4 are communicated with the oil tank to reduce the oil return back pressure, the piston rod is rapidly extended, and the response speed of the oil cylinder 8 is improved.
The pilot control valve acts to make the first pilot end 21 and the pilot end of the back pressure valve 4 both conduct with the oil supply channel 1, and make the second pilot end 22 conduct with the oil tank, when the main control valve 2 switches to the second working position (right position in fig. 1), the main control valve 2 makes the rodless cavity of the oil cylinder 8 conduct with the inlet of the back pressure valve 4, and makes the rod cavity of the oil cylinder 8 conduct with the oil supply channel 1. Specifically, the rod cavity of the oil cylinder 8 is used for oil feeding, the rodless cavity of the oil cylinder 8 is used for oil return, at the moment, the first hydraulic control pilot end 21 and the hydraulic control end of the back pressure valve 4 are communicated with the oil supply oil way 1 to increase the oil return back pressure, and the retraction speed of the piston rod is slowed down.
When the main control valve 2 is in the third operating position (e.g. the neutral position in fig. 1), the state of the piston rod remains unchanged.
Optionally, the connecting oil path between the pilot control valve and the pilot hydraulic end is provided with a one-way throttle valve 9, so that the flow rate passing through the one-way throttle valve 9 can be regulated to meet the flow rate requirement of the pilot hydraulic end on hydraulic oil.
Further, the hydraulic system further comprises a first pilot oil path 10 and an electromagnetic pressure regulating valve 7, wherein the first pilot oil path 10 is connected with the hydraulic control end of the back pressure valve 4, and the electromagnetic pressure regulating valve 7 is arranged on the first pilot oil path 10; the pressure regulating oil way 5 is provided with a stop valve 6. Specifically, the hydraulic system further comprises a pilot oil pump, an oil outlet of the pilot oil pump is connected with the first pilot oil path 10, and an oil inlet of the pilot oil pump is connected with the oil tank. The Pst port in fig. 1 is for connection to a pilot pump, I-F referring to the control signal of the electromagnetic pressure regulating valve 7, by way of example.
By providing the first pilot oil passage 10 and the electromagnetic pressure regulating valve 7, the oil pressure fed to the hydraulic control end of the back pressure valve 4 by the first pilot oil passage 10 can be regulated by regulating the opening degree of the electromagnetic pressure regulating valve 7, and the regulation of the back pressure of the return oil can be realized. Meanwhile, by arranging the stop valve 6, when the oil return back pressure is regulated through the electromagnetic pressure regulating valve 7, a communication oil way between the hydraulic control end of the back pressure valve 4 and the first hydraulic control pilot end 21 is cut off, and the state regulation of the main control valve 2 and the regulation of the oil return back pressure are mutually independent.
Optionally, the first pilot oil path 10 is communicated with the oil tank through a pressure relief valve, and when the oil return back pressure is reduced through the electromagnetic pressure regulating valve 7, the pressure relief valve is opened, so as to achieve the purpose of reducing the oil return back pressure.
Further, the hydraulic system further comprises a second pilot oil path 11 and a pressure regulating valve, wherein the second pilot oil path 11 is connected with the hydraulic control end of the back pressure valve 4, and the pressure regulating valve is arranged on the second pilot oil path 11 and is not shown in fig. 1.
By providing the second pilot oil passage 11 and the pressure regulating valve, the oil pressure fed to the hydraulic control end of the back pressure valve 4 by the second pilot oil passage 11 can be regulated by regulating the opening degree of the pressure regulating valve, and the regulation of the back pressure of the return oil can be realized. Meanwhile, the stop valve 6 is matched, when the oil return back pressure is regulated by the pressure regulating valve, a communication oil way between the hydraulic control end of the back pressure valve 4 and the first hydraulic control pilot end 21 is cut off, and the state regulation of the main control valve 2 and the regulation of the oil return back pressure are mutually independent.
It should be noted that the hydraulic system may have a plurality of working components, such as an oil cylinder 8, a motor, etc., each working component is provided with a master control valve 2, each master control valve 2 and its working components form a hydraulic circuit, more than one hydraulic circuit has a pilot oil path, and the second pilot oil path 11 is used for connecting the pilot oil paths of the hydraulic circuits where the other master control valves 2 are located. The REG oil port in fig. 1 is used for connecting the pilot oil path of the hydraulic circuit where the other master valve 2 is located, for example.
Optionally, the pressure regulating valve is a two-position three-way electromagnetic reversing valve, and the pressure regulating valve can enable the hydraulic control end of the back pressure valve 4 to be communicated with the oil tank so as to reduce the back pressure of oil return.
The hydraulic system provided by the embodiment has three modes for adjusting the oil return back pressure, namely, the oil return back pressure is automatically adjusted while the main control valve 2 is adjusted through the action of the pilot handle, namely, the oil return back pressure is adjusted in real time according to the state change of the main control valve 2; secondly, the oil return back pressure is regulated by regulating the opening degree of the electromagnetic pressure regulating valve 7, and the state regulation of the main control valve 2 and the regulation of the oil return back pressure are mutually independent through the stop valve 6; thirdly, the oil return back pressure is regulated by regulating the opening degree of the pressure regulating valve, and the state regulation of the main control valve 2 and the regulation of the oil return back pressure are mutually independent through the stop valve 6. By the design, redundant control of the oil return back pressure adjusting mode can be realized, a driver can have various choices, and the oil return back pressure adjusting mode can be selected according to actual demands.
Optionally, the hydraulic system further comprises a cab, wherein a pilot handle is arranged in the cab and used for adjusting the state of the pilot control valve. As to how the state of the pilot control valve is adjusted by the pilot handle is known in the art, it is not described in detail here.
In order to realize the current switching among the three oil return back pressure adjustment modes, a first manual operation part is arranged in a cab, and is used for adjusting the opening of an electromagnetic pressure regulating valve 7 of a hydraulic system; the stop valve 6 of the hydraulic system is a manual switch valve arranged in the cab; the cab is also provided with a second manual operation part for adjusting the opening degree of a pressure regulating valve of the hydraulic system.
The driver can realize the state adjustment of the main control valve 2 and the adjustment of the oil return back pressure and the switching between the mutual independence and the mutual correlation through manually adjusting the opening and closing of the manual switch valve.
The driver can manually control the first manual operation part to realize the adjustment of the oil return back pressure by the electromagnetic pressure regulating valve 7; the second manual operation part can be manually controlled, and the oil return back pressure can be regulated by the pressure regulating valve.
The first manual operation portion and the second manual operation portion may be knobs, and for the construction vehicle equipped with the touch panel, an oil return pressure adjusting interface may be provided by programming, and the oil return pressure adjusting interface may have a slide bar or knob for adjusting the opening degree of the electromagnetic pressure regulating valve 7, a slide bar or knob for adjusting the opening degree of the pressure regulating valve, or the like.
Furthermore, the foregoing description of the preferred embodiments and the principles of the utility model is provided herein. It will be understood by those skilled in the art that the present utility model is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the utility model. Therefore, while the utility model has been described in connection with the above embodiments, the utility model is not limited to the embodiments, but may be embodied in many other equivalent forms without departing from the spirit or scope of the utility model, which is set forth in the following claims.
Claims (10)
1. A hydraulic system, comprising:
an oil supply circuit (1) and an oil tank;
the main control valve (2) is a hydraulic control valve, the main control valve (2) is provided with an oil return port and two hydraulic control pilot ends, and the oil return port is connected with the oil tank through an oil return oil way (3);
the back pressure valve (4), the back pressure valve (4) is a hydraulic control valve, the back pressure valve (4) is arranged on the oil return oil path (3), and the hydraulic control end of the back pressure valve (4) is connected with one of the hydraulic control pilot ends through a pressure regulating oil path (5);
and one of the two pilot control ends of the pilot control valve is communicated with the oil tank, and the other pilot control valve is communicated with the oil supply oil path (1).
2. The hydraulic system according to claim 1, further comprising a first pilot oil circuit (10) and an electromagnetic pressure regulating valve (7), wherein the first pilot oil circuit (10) is connected to a pilot-controlled end of the back pressure valve (4), and the electromagnetic pressure regulating valve (7) is provided in the first pilot oil circuit (10); and a stop valve (6) is arranged on the pressure regulating oil way (5).
3. The hydraulic system according to claim 2, characterized in that it further comprises a pilot oil pump, the oil outlet of which is connected to the first pilot oil circuit (10), and the oil inlet of which is connected to the oil tank.
4. The hydraulic system according to claim 2, characterized in that the first pilot oil passage (10) is in communication with the tank via a relief valve.
5. The hydraulic system according to claim 1, characterized in that the hydraulic system further comprises a second pilot oil circuit (11) and a pressure regulating valve, the second pilot oil circuit (11) being connected to the pilot-controlled end of the back pressure valve (4), the pressure regulating valve being provided in the second pilot oil circuit (11); and a stop valve (6) is arranged on the pressure regulating oil way (5).
6. The hydraulic system according to claim 5, characterized in that the pressure regulating valve is a two-position three-way electromagnetic directional valve, which enables the pilot-controlled end of the back pressure valve (4) to be in communication with the tank.
7. Hydraulic system according to any of claims 1-6, characterized in that a one-way throttle valve (9) is provided in the connecting oil circuit of the pilot control valve and the pilot-controlled pilot end.
8. The hydraulic system according to any one of claims 1 to 6, characterized in that the two pilot-controlled ends of the master valve (2) are a first pilot-controlled end (21) and a second pilot-controlled end (22), respectively, the first pilot-controlled end (21) being connected to the pilot-controlled end of the back pressure valve (4);
the hydraulic system further comprises an oil cylinder (8), the main control valve (2) is provided with a first working position and a second working position, the pilot control valve enables the first pilot end (21) and the pilot end of the back pressure valve (4) to be communicated with the oil tank, the pilot control valve enables the main control valve (2) to be in the first working position when the second pilot end (22) is communicated with the oil supply oil way (1), the main control valve (2) enables a rodless cavity of the oil cylinder (8) to be communicated with the oil supply oil way (1), and a rod cavity of the oil cylinder (8) is communicated with an inlet of the back pressure valve (4);
the pilot control valve enables the first hydraulic control pilot end (21) and the hydraulic control end of the back pressure valve (4) to be communicated with the oil supply oil way (1), and enables the second hydraulic control pilot end (22) to be communicated with the oil tank, the main control valve (2) is located at the second working position, the main control valve (2) enables the rodless cavity of the oil cylinder (8) to be communicated with the inlet of the back pressure valve (4), and enables the rod cavity of the oil cylinder (8) to be communicated with the oil supply oil way (1).
9. A construction vehicle comprising a cab, and a hydraulic system according to any one of claims 1 to 8, wherein a pilot handle is provided in the cab, the pilot handle being used to adjust the state of the pilot control valve.
10. The working vehicle according to claim 9, characterized in that the hydraulic system further comprises a first pilot oil path (10) and an electromagnetic pressure regulating valve (7), the first pilot oil path (10) is connected with the hydraulic control end of the back pressure valve (4), and the electromagnetic pressure regulating valve (7) is arranged in the first pilot oil path (10); a stop valve (6) is arranged on the pressure regulating oil way (5); a first manual operation part is arranged in the cab and used for adjusting the opening degree of an electromagnetic pressure regulating valve (7) of the hydraulic system; the stop valve (6) of the hydraulic system is a manual switch valve arranged in the cab;
the hydraulic system further comprises a second pilot oil path (11) and a pressure regulating valve, wherein the second pilot oil path (11) is communicated with a hydraulic control end of the back pressure valve (4) through the pressure regulating valve; and a second manual operation part is further arranged in the cab and used for adjusting the opening degree of a pressure regulating valve of the hydraulic system.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320813557.1U CN219549241U (en) | 2023-04-13 | 2023-04-13 | Hydraulic system and engineering vehicle |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320813557.1U CN219549241U (en) | 2023-04-13 | 2023-04-13 | Hydraulic system and engineering vehicle |
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| Publication Number | Publication Date |
|---|---|
| CN219549241U true CN219549241U (en) | 2023-08-18 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202320813557.1U Active CN219549241U (en) | 2023-04-13 | 2023-04-13 | Hydraulic system and engineering vehicle |
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| CN (1) | CN219549241U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117404362A (en) * | 2023-12-15 | 2024-01-16 | 中联重科土方机械有限公司 | Hydraulic oil return system and excavator |
-
2023
- 2023-04-13 CN CN202320813557.1U patent/CN219549241U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117404362A (en) * | 2023-12-15 | 2024-01-16 | 中联重科土方机械有限公司 | Hydraulic oil return system and excavator |
| CN117404362B (en) * | 2023-12-15 | 2024-03-15 | 中联重科土方机械有限公司 | Hydraulic oil return system and excavator |
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