CN216842432U - Hydraulic system for realizing high-low pressure unloading function - Google Patents
Hydraulic system for realizing high-low pressure unloading function Download PDFInfo
- Publication number
- CN216842432U CN216842432U CN202220583710.1U CN202220583710U CN216842432U CN 216842432 U CN216842432 U CN 216842432U CN 202220583710 U CN202220583710 U CN 202220583710U CN 216842432 U CN216842432 U CN 216842432U
- Authority
- CN
- China
- Prior art keywords
- port
- valve
- control valve
- unloading
- oil
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Fluid-Pressure Circuits (AREA)
Abstract
The application provides a hydraulic system who realizes high-low pressure off-load function includes: the device comprises an oil tank, a steering gear, a priority type steering control valve, a left steering oil cylinder, a right steering oil cylinder, a control valve and an unloading valve. The P port of the steering gear and the P port of the priority type rotation control valve are connected with an oil outlet pipeline of the oil tank; the steering gear is connected with the priority type steering control valve. The EF port of the priority type rotary control valve is connected with the P port of the unloading valve, the P port of the unloading valve is communicated with the P 'port, and the P' is converged to the working hydraulic system. A first elastic valve is arranged between the port P and the port T of the unloading valve. And a second elastic valve is arranged between the P' port of the unloading valve and the first elastic valve and is used for opening the first elastic valve to realize high-pressure unloading. And an MP' port of the unloading valve is connected with a P1 port and a P4 port of the control valve, and a P4 port of the control valve is connected with a PLS (partial pressure shift register) of the unloading valve and used for controlling the on-off of the first elastic valve to realize low-pressure unloading. The unloading device can be used for unloading high pressure and low pressure so as to reduce the temperature rise of hydraulic oil, reduce the load of a steering system and reduce the energy loss of the loader.
Description
Technical Field
The utility model belongs to loader hydraulic control field especially relates to a hydraulic system who realizes high-low pressure off-load function.
Background
The loader is used as a widely-used engineering machine, and the complexity of the work of a hydraulic system is determined by different purposes and complex working conditions. The common loader hydraulic system at present mainly comprises a split system and a double-pump converging system.
The double-pump confluence system is a system for simultaneously driving working mechanisms including a bucket, a support arm, and the like by using hydraulic pressures of a steering system and a working hydraulic system. When the operating mechanism is in heavy load and needs to be lifted slowly, the working hydraulic system is in a high-pressure small-flow working state, oil which flows into the working hydraulic system from the steering system is redundant, if the hydraulic oil of the steering system is continuously input into the working hydraulic system, the hydraulic oil can generate higher temperature rise, the burden of a cooling system is increased, and the energy loss of the whole machine equipment is increased.
SUMMERY OF THE UTILITY MODEL
For solving prior art not enough, the utility model provides a realize hydraulic system of high-low pressure off-load function can all carry out the pressure release to the hydraulic oil that steering system provided when work hydraulic system is in high pressure and low pressure state to reduce the temperature rise of hydraulic oil, reduce the steering system load, and reduce the energy loss of loader.
In order to realize the purpose of the utility model, the following scheme is proposed:
a hydraulic system for realizing high-low pressure unloading function comprises: the hydraulic steering system comprises an oil tank, a steering gear, a priority type steering control valve, a left steering oil cylinder, a right steering oil cylinder, a control valve and an unloading valve.
The P port of the steering gear and the P port of the priority type rotary control valve are connected with an oil outlet pipeline of the oil tank; the steering gear is connected with the priority type steering control valve and is used for controlling the left steering oil cylinder and the right steering oil cylinder.
The EF port of the priority type rotary control valve is connected with the P port of the unloading valve, the P port of the unloading valve is communicated with the P 'port, and the P' is converged to the working hydraulic system.
And a first elastic valve is arranged between the port P of the unloading valve and the port T and is used for controlling the on-off between the port P of the unloading valve and the port T.
And a second elastic valve is arranged between the P' port of the unloading valve and the first elastic valve, when the pressure of the working hydraulic system rises to a preset pressure, the second elastic valve is opened, and the first elastic valve is opened by hydraulic oil discharged from the second elastic valve, so that high-pressure unloading is realized.
An MP' port of the unloading valve is connected with a P1 port and a P4 port of the control valve, a P1 port of the control valve is used for pushing a valve core of the control valve to move, a P4 port of the control valve is connected with a PLS (partial pressure differential) of the unloading valve and used for controlling the on-off of the first elastic valve, and the first elastic valve is opened through a P4 port of the control valve to realize low-pressure unloading.
Furthermore, the priority type rotary control valve is provided with an opening A and an opening B which are used for supplying oil to the left steering oil cylinder and the right steering oil cylinder; the A port of the priority type rotation control valve is connected with a rod cavity of the left steering oil cylinder and a rodless cavity of the right steering oil cylinder; the port B of the priority type rotary control valve is connected with the rodless cavity of the left steering oil cylinder and the rod cavity of the right steering oil cylinder.
Furthermore, the control valve is also provided with a port P2 and a port P3, when the controller valve core is pushed to move to a preset position by hydraulic oil of the port P1 of the control valve, the port P2 of the control valve is communicated with the port P5, and the hydraulic oil of the valve core of the unloading valve flows back to the oil tank through the port P5 of the control valve; meanwhile, the port P3 is connected with the port P4, the port P3 is in a blocking structure, and oil passing through the port Mp' of the unloading valve is blocked.
The valve core of the control valve is reset through a spring, when the valve core of the control valve is in a reset state, a P2 port of the control valve is connected with a P4 port, a P3 port is disconnected with a P5 port, hydraulic oil input into a P4 port of the control valve through an MP' port of the unloading valve is output from a P2 port of the control valve, the first elastic valve is pushed through a PLS port of the unloading valve, the P port of the unloading valve is communicated with a T port, and low-pressure unloading in high-speed running is achieved.
Further, a T port of the unloading valve is communicated with an oil return pipe of the oil tank; the Ls port of the steering gear is connected with the Ls port of the priority type rotary control valve and is connected with an oil return pipe of the oil tank through the T1 port of the priority type rotary control valve; the T port of the priority type rotary control valve is connected with the oil tank through an oil return pipe; and a T port of the steering gear is connected with an oil return pipe of the oil tank.
Further, still strain including the oil absorption, the level gauge, empty filter, return oil is strained and the gear pump, and the oil absorption is strained the oil pipe import department of locating the oil tank, and is located the inside of oil tank, and the outer wall of oil tank is worn to locate by empty filter to the level gauge, and the return oil is strained and is located on the oil tank returns the oil pipe, and the gear pump is located on the oil pipe of oil tank, and is located between oil tank and the steering gear.
The beneficial effects of the utility model reside in that: the first elastic valve is controlled to be opened through the second elastic valve, so that hydraulic oil input into the unloading valve by the steering system through the priority type rotary control valve is directly discharged back to the oil tank from a T port of the unloading valve to realize high-pressure unloading, and the working state is suitable for a working hydraulic system to be used during high-pressure operation; the P4 port and the P2 port of the control valve are communicated with the PLS of the unloading valve, and the first elastic valve is opened, so that low-pressure unloading is realized.
Drawings
The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.
FIG. 1 shows a schematic of the hydraulic system of the present application.
Fig. 2 shows the structure and connection schematic of the unloading valve and the control valve.
Fig. 3 shows a schematic diagram of the state of the control valve when the low pressure is unloaded.
Fig. 4 shows a schematic diagram of the state of the control valve when it is exposed to low pressure unloading.
The labels in the figure are: an oil tank-1, an oil absorption filter-2, a liquid level meter-3, an air filter-4, an oil return filter-5, a gear pump-6, a steering gear-7, a priority type rotation control valve-8, a left steering oil cylinder-9, a right steering oil cylinder-10, a control valve-11, an unloading valve-12, a first elastic valve-121 and a second elastic valve-122.
Detailed Description
To make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the following detailed description of the embodiments of the present invention is provided with reference to the accompanying drawings, but the described embodiments of the present invention are some embodiments of the present invention, not all embodiments.
It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate the position or positional relationship based on the position or positional relationship shown in the drawings, or the position or positional relationship that the product of the present invention is usually placed when in use, and this is only for the convenience of description of the present invention and simplification of the description. The terms "first," "second," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance. The terms "parallel", "perpendicular", etc. do not require that the components be absolutely parallel or perpendicular, but may be slightly inclined.
In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; either directly or indirectly through intervening media, or through both elements. The specific meaning of the above terms in the present invention can be understood according to specific situations by those of ordinary skill in the art.
Example 1
As shown in fig. 1 and 2, a hydraulic system for implementing a high-low pressure unloading function includes: the hydraulic control system comprises an oil tank 1, a steering gear 7, a priority type steering control valve 8, a left steering oil cylinder 9, a right steering oil cylinder 10, a control valve 11 and an unloading valve 12.
As shown in fig. 1, the port P of the steering gear 7 and the port P of the priority type rotation control valve 8 are connected to the outlet line of the oil tank 1. The steering gear 7 is connected with the priority type rotary control valve 8, specifically, an R port of the steering gear 7 is connected with a b port of the priority type rotary control valve 8, and an L port of the steering gear 7 is connected with an a port of the priority type rotary control valve 8, and is used for controlling a left steering oil cylinder 9 and a right steering oil cylinder 10.
As shown in fig. 2, the EF port of the priority type rotary control valve 8 is connected to the P port of the unloading valve 12, and part of the hydraulic oil of the priority type rotary control valve 8 is input to the unloading valve 12 through the EF port of the priority type rotary control valve 8 and is merged into the working hydraulic system through the P' port of the unloading valve 12. The P port of the unloading valve 12 is communicated with the P 'port, and the P' is converged to a working hydraulic system.
As shown in fig. 2, a first elastic valve 121 is provided between the port P and the port T of the unloading valve 12 for controlling the on-off between the port P and the port T of the unloading valve 12, when the first elastic valve 121 is opened, the port P and the port T of the unloading valve 12 can be connected, and the hydraulic oil discharged from the port EF of the preferred rotary control valve 8 returns to the oil tank 1 through the port T of the unloading valve 12 for unloading.
As shown in fig. 2, a second elastic valve 122 is provided between the port P' of the unloading valve 12 and the first elastic valve 121, and the opening pressure of the second elastic valve 122 is greater than the opening pressure of the first elastic valve 121. When the pressure of the working hydraulic system rises to a predetermined pressure, the hydraulic oil pressure at the port P' of the unloading valve 12 is the same as the predetermined pressure, the second elastic valve 122 is opened, the hydraulic oil discharged from the second elastic valve 122 opens the first elastic valve 121, the port P of the unloading valve 12 is communicated with the port T, and the hydraulic oil flows back to the oil tank 1 through the port T, so that high-pressure unloading is realized.
When the working system is in a high-pressure state, the oil pressure required by the working system is large, but the oil quantity required by the working system is small, and most of the hydraulic oil provided by the steering system is not required. Because the port P ' of the unloading valve 12 is communicated with the working hydraulic system by confluence, the hydraulic pressure at the port P ' of the unloading valve 12 is also in a high-pressure state equal to that of the working hydraulic system, and in order to prevent the high-pressure hydraulic oil in the working hydraulic system from flowing back to the port P of the unloading valve 12, a check valve is arranged between the port P and the port P '. When the pressure at the P' port is greater than the set value, the second elastic valve 122 is opened, and the first elastic valve 121 is controlled to be opened by the second elastic valve 122, so that the hydraulic oil input into the unloading valve 12 by the steering system through the priority type rotary control valve 8 is directly discharged back to the oil tank from the T port of the unloading valve 12, and high-pressure unloading is realized, that is, when the working hydraulic system is at high pressure, the unloading state performed by the unloading valve 12 is called high-pressure unloading. So as to reduce the hydraulic oil quantity input into the working hydraulic system by a steering system, namely the priority type rotary control valve 8, thereby reducing the temperature rise of the hydraulic oil and the mechanical energy loss required for converging the hydraulic oil into the working hydraulic system.
In the embodiment, the high pressure unloading pressure is set to 210bar, the opening pressure of the first elastic valve 121 is set to be less than or equal to 3.2bar, when the pressure at the P' port of the unloading valve 12 reaches 210bar, the second pressure valve 122 is opened, and the pressure input into the first pressure valve 121 through the second pressure valve 122 is certainly greater than 3.2bar, so that the first pressure valve 121 is opened, and the hydraulic oil input into the unloading valve 12 by the steering system through the priority type rotary control valve 8 is directly discharged back to the oil tank from the T port of the unloading valve 12, thereby realizing the high pressure unloading.
The MP' port of the unloading valve 12 is connected with the P1 port and the P4 port of the control valve 11, the P1 port of the control valve 11 is used for pushing a valve core of the control valve 11 to move, the P4 of the control valve 11 is connected with the PLS of the unloading valve 12 and is used for controlling the on-off of the first elastic valve 121, the first elastic valve 121 is opened through the P4 of the control valve 11, the P port and the T port of the unloading valve 12 are communicated, and the oil flows back to the oil tank 1 through the T port, so that low-pressure unloading is realized.
In this embodiment, when the working hydraulic system does not work, the loader is in a high-speed transportation state, the middle pressure of the multi-way valve is lower than 7kg and greater than 3.2bar, and the opening pressure of the first elastic spring 121 is less than or equal to 3.2 bar. The control valve 11 is in the state shown in fig. 3, the working hydraulic system oil passes through the port P 'and the port Mp' of the unloading valve 12, then passes through the port P4 of the control valve 11, and finally pushes the first elastic valve 121 of the unloading valve 12 to open through the port P2 of the control valve 11, and the surplus flow coming from the port EF of the priority type rotary control valve 8 is discharged back to the oil tank 1 from the port T of the unloading valve 12, so that the low-pressure unloading in the high-speed running is realized
Preferably, as shown in fig. 1, the steering gear 7, the priority type rotation control valve 8, the control valve 11 and the unloading valve 12 are all provided with a T port connected with a return pipe of the oil tank 1.
Specifically, a T port of the unloading valve 12 is communicated with an oil return pipe of the oil tank 1; an Ls port of the steering gear 7 is connected with an Ls port of the priority type rotary control valve 8 and is connected with an oil return pipe of the oil tank 1 through a T1 port of the priority type rotary control valve 8; the T port of the priority type rotary control valve 8 is connected with the oil tank 1 through an oil return pipe; the T port of the steering gear 7 is connected with an oil return pipe of the oil tank 1.
Specifically, as shown in fig. 1, the priority type rotation control valve 8 has ports a and B for supplying oil to the left steering cylinder 9 and the right steering cylinder 10.
More specifically, the port a of the priority type rotation control valve 8 is connected to the rod chamber of the left steering cylinder 9 and the rodless chamber of the right steering cylinder 10. The port B of the priority type rotary control valve 8 is connected with a rodless cavity of the left steering oil cylinder 9 and a rod cavity of the right steering oil cylinder 10. The rod cavity is a cavity body of which the piston of the hydraulic cylinder is connected with one side of the hydraulic rod; the rodless cavity is a cavity on one side of the piston and the hydraulic cylinder, which is not provided with the hydraulic rod. The pressure of the rod cavity and the rodless cavity on two sides of the piston is balanced by using hydraulic oil so as to push the piston and the hydraulic rod to move.
Example 2
As shown in figure 1, the hydraulic system for realizing the high-low pressure unloading function comprises an oil tank 1, an oil suction filter 2, a liquid level meter 3, an air filter 4, an oil return filter 5, a gear pump 6, a steering gear 7, a priority type rotation control valve 8, a left steering oil cylinder 9, a right steering oil cylinder 10, a control valve 11 and an unloading valve 12. The oil absorption is strained 2 and is located the import department of oil pipe of oil tank 1, and is located the inside of oil tank 1, and the outer wall of oil tank 1 is worn to locate by level gauge 3 and empty filter 4, and the oil return is strained 5 and is located on oil pipe is returned to oil tank 1, and gear pump 6 is located on oil pipe of oil tank 1, and is located between oil tank 1 and the steering gear 7.
Example 3
As shown in fig. 3, the control valve 11 further has ports P2 and P3.
As shown in fig. 4, after the controller spool is pushed to move to a predetermined position by the hydraulic oil of the P1 port of the control valve 11, the P2 port of the control valve 11 is communicated with the P5 port, and the hydraulic oil of the spool of the unloading valve 12 flows back to the oil tank 1 through the P5 port of the control valve 11; meanwhile, the port P3 is connected with the port P4, the port P3 is a blocking structure, at this time, oil passing through the port P 'of the unloading valve 12Mp' is blocked, the port P4 of the control valve 11 cannot inject hydraulic oil into the first elastic valve 121 through the PLS of the unloading valve 12, so that the low-pressure unloading function is disabled, and at this time, the control valve can be switched to a high-pressure unloading state.
The spool of the control valve 11 is restored by a spring. As shown in fig. 3, when the spool of the control valve 11 is in the reset state, the port P2 of the control valve 11 is connected to the port P4, the port P3 is disconnected from the port P5, the hydraulic oil input to the port P4 of the control valve 11 through the port MP' of the unloading valve 12 is output from the port P2 of the control valve 11, and the first elastic force valve 121 is pushed through the port PLS of the unloading valve 12, so that the port P of the unloading valve 12 is connected to the port T, and low-pressure unloading during high-speed traveling is realized.
The foregoing is only a preferred embodiment of the invention and is not intended to be the only or limiting embodiment of the invention. It should be understood by those skilled in the art that various changes and equivalent substitutions made herein may be made without departing from the scope of the invention as defined by the appended claims.
Claims (5)
1. A hydraulic system for realizing high-low pressure unloading function is characterized by comprising: the device comprises an oil tank (1), a steering gear (7), a priority type steering control valve (8), a left steering oil cylinder (9), a right steering oil cylinder (10), a control valve (11) and an unloading valve (12);
the P port of the steering gear (7) and the P port of the priority type rotary control valve (8) are connected with an oil outlet pipeline of the oil tank (1); the steering gear (7) is connected with the priority type steering control valve (8) and is used for controlling a left steering oil cylinder (9) and a right steering oil cylinder (10);
an EF port of the priority type rotary control valve (8) is connected with a P port of an unloading valve (12), the P port of the unloading valve (12) is communicated with a P 'port, and P' is converged to a working hydraulic system;
a first elastic valve (121) is arranged between the port P and the port T of the unloading valve (12) and is used for controlling the connection and disconnection between the port P and the port T of the unloading valve (12);
a second elastic valve (122) is arranged between the P' port of the unloading valve (12) and the first elastic valve (121), when the pressure of the working hydraulic system rises to a preset pressure, the second elastic valve (122) is opened, hydraulic oil discharged from the second elastic valve (122) opens the first elastic valve (121), and high-pressure unloading is realized;
an MP' port of the unloading valve (12) is connected with a P1 port and a P4 port of the control valve (11), a P1 port of the control valve (11) is used for pushing a valve core of the control valve (11) to move, a P4 port of the control valve (11) is connected with a PLS (partial pressure system) of the unloading valve (12) and used for controlling the on-off of the first elastic valve (121), and the first elastic valve (121) is opened through a P4 port of the control valve (11) to realize low-pressure unloading.
2. The hydraulic system for realizing the unloading function of high and low pressure as claimed in claim 1, wherein the priority type rotary control valve (8) is provided with an A port and a B port and is used for supplying oil to the left steering oil cylinder (9) and the right steering oil cylinder (10); the A port of the priority type rotation control valve (8) is connected with a rod cavity of the left steering oil cylinder (9) and a rodless cavity of the right steering oil cylinder (10); the port B of the priority type rotation control valve (8) is connected with a rodless cavity of the left steering oil cylinder (9) and a rod cavity of the right steering oil cylinder (10).
3. The hydraulic system for realizing the high-low pressure unloading function according to claim 1, wherein the control valve (11) is further provided with a port P2 and a port P3, when the controller valve core is pushed to move to a preset position by hydraulic oil of the port P1 of the control valve (11), the port P2 of the control valve (11) is communicated with the port P5, and the hydraulic oil of the valve core of the unloading valve (12) flows back to the oil tank (1) through the port P5 of the control valve (11); meanwhile, the port P3 is connected with the port P4, the port P3 is a blocking structure, and oil passing through the port Mp' of the unloading valve (12) is blocked;
the valve core of the control valve (11) is reset through a spring, when the valve core of the control valve (11) is in a reset state, a P2 port of the control valve (11) is connected with a P4 port, a P3 port is disconnected with a P5 port, hydraulic oil input into the P4 port of the control valve (11) through an MP' port of the unloading valve (12) is output from a P2 port of the control valve (11), the first elastic force valve (121) is pushed through a PLS port of the unloading valve (12), the P port of the unloading valve (12) is communicated with the T port, and low-pressure unloading in high-speed running is achieved.
4. The hydraulic system for realizing the high-low pressure unloading function according to claim 1, wherein a T port of the unloading valve (12) is communicated with an oil return pipe of the oil tank (1); an Ls port of the steering gear (7) is connected with an Ls port of the priority type rotary control valve (8) and is connected with an oil return pipe of the oil tank (1) through a T1 port of the priority type rotary control valve (8); the T port of the priority type rotary control valve (8) is connected with the oil tank (1) through an oil return pipe; the T port of the steering gear (7) is connected with an oil return pipe of the oil tank (1).
5. The hydraulic system capable of realizing the high-low pressure unloading function according to claim 1, further comprising an oil suction filter (2), a liquid level meter (3), an air filter (4), an oil return filter (5) and a gear pump (6), wherein the oil suction filter (2) is arranged at an inlet of an oil outlet pipe of the oil tank (1) and is located inside the oil tank (1), the liquid level meter (3) and the air filter (4) are arranged on the outer wall of the oil tank (1) in a penetrating manner, the oil return filter (5) is arranged on the oil return pipe of the oil tank (1), and the gear pump (6) is arranged on the oil outlet pipe of the oil tank (1) and is located between the oil tank (1) and the steering gear (7).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220583710.1U CN216842432U (en) | 2022-03-17 | 2022-03-17 | Hydraulic system for realizing high-low pressure unloading function |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220583710.1U CN216842432U (en) | 2022-03-17 | 2022-03-17 | Hydraulic system for realizing high-low pressure unloading function |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN216842432U true CN216842432U (en) | 2022-06-28 |
Family
ID=82095905
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202220583710.1U Active CN216842432U (en) | 2022-03-17 | 2022-03-17 | Hydraulic system for realizing high-low pressure unloading function |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN216842432U (en) |
-
2022
- 2022-03-17 CN CN202220583710.1U patent/CN216842432U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110228774B (en) | Fork truck and fork truck portal hydraulic system that goes up and down | |
| CN101680206A (en) | Hydraulic load control valve device | |
| CN113669312A (en) | Closed hydraulic control system and engineering machinery | |
| CN111677717A (en) | Hydraulic system of hydraulic valve test bench | |
| WO2008055147A2 (en) | System and method for pilot-operated high pressure valve | |
| KR20150077431A (en) | Shovel | |
| CN111733921A (en) | Loader hydraulic system and engineering machinery | |
| CN216842432U (en) | Hydraulic system for realizing high-low pressure unloading function | |
| CN109515417A (en) | Brake fluid system and crane | |
| CN219605691U (en) | Hydraulic control system of arm-pulling hook equipment | |
| CN114508515A (en) | Hydraulic system for realizing high-low pressure unloading function | |
| CN211398540U (en) | Hydraulic system of automatic transmission | |
| CN216199342U (en) | Closed hydraulic control system and engineering machinery | |
| CN112112867B (en) | Hydraulic control type exhaust valve unit, hydraulic control type exhaust winch control system and winch | |
| CN105329817A (en) | Single-pump hydraulic system used for forklift | |
| CN213143188U (en) | Quick-change pipeline control system and excavator | |
| CN102285143B (en) | Variable displacement piston pump system for hydraulic machine | |
| CN115111212A (en) | Preferential steering load sensing system capable of isolating high voltage and vehicle | |
| CN210290301U (en) | Radar antenna lifting system | |
| CN211470605U (en) | Integrated multi-way valve | |
| CN218717800U (en) | Closed hydraulic system | |
| CN106525694B (en) | Electromagnetic induction type osmotic pressure loading device for rock permeability test | |
| CN212868056U (en) | Pneumatic-hydraulic hybrid drive control unit | |
| CN215801937U (en) | Fixed-variable hydraulic system of loader | |
| CN113090750A (en) | Hydraulic system of automatic transmission |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |