CN113944668A - Pilot control system - Google Patents
Pilot control system Download PDFInfo
- Publication number
- CN113944668A CN113944668A CN202111295169.0A CN202111295169A CN113944668A CN 113944668 A CN113944668 A CN 113944668A CN 202111295169 A CN202111295169 A CN 202111295169A CN 113944668 A CN113944668 A CN 113944668A
- Authority
- CN
- China
- Prior art keywords
- valve
- valve body
- spring seat
- valve rod
- oil port
- 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.)
- Pending
Links
- 230000000670 limiting effect Effects 0.000 claims description 19
- 238000006073 displacement reaction Methods 0.000 claims description 6
- 125000006850 spacer group Chemical group 0.000 claims description 3
- 230000007935 neutral effect Effects 0.000 claims 1
- 239000003921 oil Substances 0.000 description 55
- 230000008859 change Effects 0.000 description 5
- 239000010720 hydraulic oil Substances 0.000 description 5
- 230000009471 action Effects 0.000 description 3
- 239000000428 dust Substances 0.000 description 3
- 238000007789 sealing Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B13/00—Details of servomotor systems ; Valves for servomotor systems
- F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
- F15B13/021—Valves for interconnecting the fluid chambers of an actuator
Abstract
The invention relates to the technical field of hydraulic pressure, in particular to a pilot control system, which comprises a pilot control valve group, wherein the pilot control valve group comprises a valve rod, a valve body assembly and a centering assembly; the valve rod is arranged in the accommodating cavity of the valve body assembly in a sliding mode, one end of the valve rod extends out relative to one end of the valve body assembly, and the valve rod can be connected with a control part of the working valve; the valve body assembly is provided with a first oil port and a second oil port which are communicated with the accommodating cavity; the centering assembly is arranged at the other end of the valve body assembly and is connected with the valve rod, and when the first oil port and the second oil port do not have oil inlet, the centering assembly can enable the valve rod to be located at the middle position; and a first control port of the pilot handle is communicated with the first oil port, and a second control port of the pilot handle is communicated with the second oil port. The invention can improve the operation performance on the basis of not changing the system main body.
Description
Technical Field
The invention relates to the technical field of hydraulic pressure, in particular to a pilot control system.
Background
The working device of the construction machine is generally controlled by a working valve, and the traveling system is controlled by a speed change valve. At present, most of the mainstream working valves, speed change valves and the like adopt mechanical link control. The mechanical connecting rod has complex operation structure, difficult adjustment, larger integral operating force and poor comfort.
The hydraulic pilot handle control working system has the characteristics of small operating force, simple connection and the like, is applied to high-end models more generally, is simple to connect and convenient to arrange due to the fact that related mechanical link mechanisms are omitted and hydraulic hoses are adopted for control, and is relatively high in overall application cost.
The mechanical working valve/speed change valve and other main parts have mature application bases for many years, and the matching cost is low. If upgrade for improving the operation comfort, and directly change to present novel liquid accuse guide system, need replace essential element such as original working valve, change valve, the system main part changes greatly, and is with higher costs to old money model upgrade, and maneuverability is not big moreover.
Therefore, a pilot control system is needed to solve the above technical problems.
Disclosure of Invention
The invention aims to provide a pilot control system which can improve the operation performance on the basis of not changing a system main body.
In order to achieve the purpose, the invention adopts the following technical scheme:
a pilot control system, comprising:
the pilot control valve group comprises a valve rod, a valve body assembly and a centering assembly;
the valve rod is arranged in the accommodating cavity of the valve body assembly in a sliding mode, one end of the valve rod extends out relative to one end of the valve body assembly, and the valve rod can be connected with a control part of the working valve;
the valve body assembly is provided with a first oil port and a second oil port which are communicated with the accommodating cavity;
the centering assembly is arranged at the other end of the valve body assembly and is connected with the valve rod, and when the first oil port and the second oil port do not have oil inlet, the centering assembly can enable the valve rod to be located at the middle position;
the first control port of the pilot handle is communicated with the first oil port, the second control port of the pilot handle is communicated with the second oil port, and the pilot handle can control the movement direction and the movement speed of the valve rod.
Further, the valve rod is convexly provided with a sliding ring portion, and when the valve rod is located at the middle position, the sliding ring portion is located between the first oil port and the second oil port.
Furthermore, an annular groove is formed in the sliding ring portion, and a first sealing ring is arranged in the annular groove.
Further, a connecting rod is arranged at one end, extending out relative to the valve body assembly, of the valve rod, and the connecting rod can be connected with a control part of the working valve.
Further, the valve body assembly comprises a valve body, the valve body is provided with the first oil port and the second oil port, one end of the valve body is provided with a first end cover, the other end of the valve body is provided with a second end cover, one end of the valve rod is opposite to the first end cover, and the other end of the valve rod is opposite to the second end cover and is connected with the centering assembly.
Furthermore, a first limiting piece is arranged on one side, facing the valve body, of the first end cover, and is located in the accommodating cavity, and the first limiting piece is used for limiting displacement of the valve rod.
Furthermore, a second limiting piece is arranged on one side, facing the valve body, of the second end cover, and is located in the accommodating cavity, and the second limiting piece is used for limiting the displacement of the valve rod.
Further, the centering assembly comprises:
the fixing plate is U-shaped and is fixedly arranged on the valve body assembly;
the valve rod is sleeved with the first spring seat, the first spring seat can be abutted to the valve body assembly, the second spring seat and the first spring seat are arranged at intervals along the movement direction of the valve rod, an elastic piece is arranged between the first spring seat and the second spring seat, one end of the elastic piece is abutted to the first spring seat, and the other end of the elastic piece is abutted to the second spring seat;
the valve rod is far away from one end of the working valve is provided with a connecting piece, the connecting piece can be abutted to one side, deviating from the first spring seat, of the second spring seat, and the valve rod can drive the first spring seat and the second spring seat to move.
Further, a gasket is arranged between the connecting piece and the second spring seat.
Furthermore, an electric control valve group is arranged on the pilot handle and provided with the first control port and the second control port.
The invention has the beneficial effects that:
the invention provides a pilot control system which comprises a pilot valve group and a pilot handle, wherein a valve rod of the pilot valve group is arranged in a valve body assembly, one end of the valve rod extends out of the valve body assembly relative to the valve body assembly and is connected with a control part of a working valve, a first oil port and a second oil port are formed in the valve body assembly, a first control port of the pilot handle is communicated with the first oil port, a second control port of the pilot handle is communicated with the second oil port, hydraulic oil can be controlled to enter from the first oil port or enter from the second oil port by controlling the pilot handle, and the purpose of controlling the movement direction of the valve rod is achieved. The pressure of the output hydraulic oil can be controlled through the operation amplitude of the pilot handle, so that the aim of adjusting the movement speed of the valve rod is fulfilled. Because the valve rod is connected with the control part of the working valve, the working valve can be controlled through the pilot handle. Through the setting, on the basis of not changing the system main body, the control performance of the engineering machinery can be improved, and the old model can be upgraded with low cost.
Drawings
FIG. 1 is a schematic diagram of a pilot control system according to an embodiment of the present invention;
fig. 2 is a cross-sectional view of a pilot valve assembly in a pilot control system according to an embodiment of the present invention;
fig. 3 is a schematic diagram of a pilot control system according to a second embodiment of the present invention.
In the figure:
1. a valve body assembly; 11. a valve body; 12. a first end cap; 13. a second seal ring; 14. a second end cap; 15. a third seal ring; 16. a dust ring; 17. a first oil port; 18. a second oil port; 2. a centering assembly; 21. a fixing plate; 22. a first spring seat; 23. a second spring seat; 24. an elastic member; 25. a sleeve; 26. a connecting member; 27. a gasket; 3. a valve stem; 31. a guide slip ring; 32. a first seal ring; 33. a connecting rod; 4. a pilot handle; 41. an electric control valve group.
Detailed Description
The technical scheme of the invention is further explained by combining the attached drawings and the embodiment. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some but not all of the elements associated with the present invention are shown in the drawings.
In the description of the present invention, it should be noted that unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection or a removable connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.
Example one
In order to improve the operation performance of the engineering machine on the basis of not changing the system main body, as shown in fig. 1-2, the invention provides a pilot control system. The pilot control system includes: a pilot control valve group and a pilot handle 4.
The pilot control valve group comprises a valve rod 3, a valve body assembly 1 and a centering assembly 2; the valve rod 3 is arranged in the accommodating cavity of the valve body assembly 1 in a sliding mode, one end of the valve rod 3 extends out relative to one end of the valve body assembly 1, and the valve rod 3 can be connected with a control part of the working valve; a first oil port 17 and a second oil port 18 which are communicated with the accommodating cavity are formed in the valve body assembly 1; the centering assembly 2 is arranged at the other end of the valve body assembly 1 and is connected with the valve rod 3, and when the first oil port 17 and the second oil port 18 do not feed oil, the centering assembly 2 can enable the valve rod 3 to be located at the middle position; the first control port of the pilot handle 4 is communicated with the first oil port 17, the second control port of the pilot handle 4 is communicated with the second oil port 18, and the pilot handle 4 can control the movement direction and the movement speed of the valve rod 3.
The hydraulic oil can be controlled to enter from the first oil port 17 or enter from the second oil port 18 by controlling the pilot handle 4, so as to achieve the purpose of controlling the movement direction of the valve rod 3. The pressure of the output hydraulic oil can be controlled through the operation amplitude of the pilot handle 4, so that the purpose of adjusting the output pressure and the movement position of the valve rod 3 is achieved. Since the valve rod 3 is connected with the control part of the working valve, the working valve can be controlled through the pilot handle 4. Through the setting, on the basis of not changing the system main body, the control performance of the engineering machinery can be improved, and the old model can be upgraded with low cost.
Further, a sliding ring part is convexly arranged on the valve rod 3, and when the valve rod 3 is in a middle position, the sliding ring part is positioned between the first oil port 17 and the second oil port 18. Specifically, slip ring portion and valve rod 3 are integral structure, divide into first pole chamber and second pole chamber with the holding chamber through slip ring portion, first hydraulic fluid port 17 and first pole chamber intercommunication, second hydraulic fluid port 18 and second pole chamber intercommunication. When the first rod cavity is filled with oil, the second rod cavity returns oil, the valve rod 3 moves towards the first direction, and when the second rod cavity is filled with oil, the first rod cavity returns oil, and the valve rod 3 moves towards the first direction opposite to the first direction. Thereby can control the work of work valve through control oil feed and oil pressure.
Furthermore, an annular groove is formed in the sliding ring portion, and a first sealing ring 32 is arranged in the annular groove. A first seal 32 is located between the valve body assembly 1 and the valve stem 3. The clearance between the first rod cavity and the second rod cavity can be blocked by arranging the first sealing ring 32, and the effect of preventing oil leakage between the first rod cavity and the second rod cavity is achieved.
In order to promote the fluency of the movement of the valve stem 3 in the housing chamber, in the present embodiment, a guiding slip ring 31 is provided on the sliding ring portion.
Further, the end of the valve rod 3 protruding with respect to the valve body assembly 1 is provided with a connecting rod 33, and the connecting rod 33 can be connected with a control member of the operating valve. Through setting up connecting rod 33, connecting rod 33 plays the transitional action of connecting valve rod 3 and control piece, is convenient for design connecting rod 33 according to the control piece shape and the position of operating valve to the convenience is installed and is used on engineering machine tool.
Further, the valve body assembly 1 includes a valve body 11, a first oil port 17 and a second oil port 18 are provided on the valve body 11, a first end cap 12 is fixedly provided at one end of the valve body 11, a second end cap 14 is fixedly provided at the other end of the valve body 11, one end of the valve rod 3 extends out of the first end cap 12, and the other end of the valve rod 3 extends out of the second end cap 14 and is connected with the centering assembly 2. The end of the valve body 11 can be blocked by arranging the first end cover 12 and the second end cover 14, so that dust and impurities are prevented from entering the accommodating cavity. In order to prevent the hydraulic oil from leaking through the gaps between the first and second end caps 12 and 14 and the valve body 11, a second seal ring 13 is provided between the first end cap 12 and the valve body 11, a third seal ring 15 is provided between the second end cap 14 and the valve body 11, and a dust seal ring 16 is provided between the second end cap 14 and the valve body 11.
Further, a fixed rod on one side of the first end cover 12 facing the valve body 11 is provided with a first limiting member, the first limiting member is located in the accommodating cavity, and the first limiting member is used for limiting displacement of the valve rod 3, so that a mechanical hard limiting effect is achieved. Further, a second limiting member is fixedly disposed on one side of the second end cover 14 facing the valve body 11, the second limiting member is located in the accommodating cavity, and the second limiting member is used for limiting displacement of the valve rod 3, so that a mechanical hard limiting effect is achieved.
Further, the centering assembly 2 comprises: a fixed plate 21, a first spring seat 22 and a second spring seat 23.
Wherein, the fixed plate 21 is U-shaped, and the fixed plate 21 is fixedly arranged on the second end cover 14 of the valve body assembly 1; the first spring seat 22 is sleeved on the valve rod 3 and can be abutted against the second end cover 14, the second spring seat 23 and the first spring seat 22 are arranged at intervals along the moving direction of the valve rod 3, an elastic part 24 is arranged between the first spring seat 22 and the second spring seat 23, one end of the elastic part 24 is abutted against the first spring seat 22, and the other end of the elastic part 24 is abutted against the second spring seat 23; one end of the valve rod 3, which is far away from the working valve, is provided with a connecting piece 26, the connecting piece 26 can be abutted against one side of the second spring seat 23, which is far away from the first spring seat 22, and the valve rod 3 can drive the first spring seat 22 and the second spring seat 23 to move. Through setting up centering subassembly 2, when not having the oil feed, can make valve rod 3 be in the meso position.
In this embodiment, when the second oil port 18 feeds oil and the first oil port 17 feeds oil, the valve rod 3 moves leftwards, the valve rod 3 drives the first spring seat 22 to extrude the elastic member 24, and at this time, the second spring seat 23 abuts against the fixed plate 21; when the first oil port 17 is filled with oil, and the second oil port 18 is filled with oil, the valve rod 3 moves rightwards, the connecting piece 26 drives the second spring seat 23 to extrude the elastic piece 24, and at the moment, the first spring seat 22 is abutted to the second end cover 14; after the first oil port 17 and the second oil port 18 do not feed oil, the valve rod 3 is reset to the middle position under the action of the elastic piece 24.
Further, a spacer 27 is provided between the connecting member 26 and the second spring seat 23. Specifically, the gasket 27 is fitted over the connecting member 26. The distance between the second spring seat 23 and the first spring seat 22 can be adjusted by providing the spacer 27, thereby functioning to adjust the elastic force of the elastic member 24. In this embodiment, the elastic member 24 is a compression spring. In order to determine the initial position of the connecting element 26 and at the same time ensure a secure mounting of the connecting element 26, a sleeve 25 is fitted over the connecting element 26.
In the present embodiment, the pilot handle 4 is a hydraulic pilot handle. The hydraulic pilot handle is one of common operating handles of engineering machinery. The handle is generally provided with an oil inlet and an oil return port, and two or four output control oil ports, after the pilot handle 4 is operated in a certain direction, the lower part of the pilot handle 4 outputs certain pressure corresponding to each output control oil port, and the larger the operation amplitude is, the larger the output pressure is, and the pressure is related to the operation stroke. In this embodiment, the pilot handle 4 pushes the main spool of the working valve to operate through the pilot control valve group, thereby implementing the operation of the working device.
Example two
The embodiment is different from the embodiment in the type of the pilot handle 4. The following details are set forth:
as shown in fig. 3, an electric valve group 41 is provided on the pilot handle 4, and the electric valve group 41 has a first control port and a second control port. In this embodiment, the pilot handle 4 is an electrically controlled pilot handle. The electric control pilot handle is one of common operation handles for engineering machinery, and can usually act in two or four directions, different electric signals can be output according to the size of the operation stroke position after the electric control pilot handle acts, the electric signals are transmitted to the controller, the controller outputs specific current/voltage according to a set program at a specific port according to the program requirement, and the output current/voltage is usually used for controlling the electric control valve group 41 to realize different actions of the working device.
It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.
Claims (10)
1. A pilot control system, comprising:
the pilot control valve group comprises a valve rod (3), a valve body assembly (1) and a centering assembly (2);
the valve rod (3) is arranged in the accommodating cavity of the valve body assembly (1) in a sliding mode, one end of the valve rod extends out relative to one end of the valve body assembly (1), and the valve rod (3) can be connected with a control part of the working valve;
a first oil port (17) and a second oil port (18) which are communicated with the accommodating cavity are formed in the valve body assembly (1);
the centering assembly (2) is arranged at the other end of the valve body assembly (1) and is connected with the valve rod (3), and when the first oil port (17) and the second oil port (18) do not feed oil, the centering assembly (2) can enable the valve rod (3) to be located at a middle position;
the first control port of the pilot handle (4) is communicated with the first oil port (17), the second control port of the pilot handle (4) is communicated with the second oil port (18), and the pilot handle (4) can control the movement direction and the movement speed of the valve rod (3).
2. A pilot control system according to claim 1, wherein the valve stem (3) is provided with a sliding ring portion protruding therefrom, the sliding ring portion being located between the first oil port (17) and the second oil port (18) when the valve stem (3) is in the neutral position.
3. The pilot control system according to claim 2, wherein the sliding ring portion defines an annular groove, and a first seal ring (32) is disposed in the annular groove.
4. A pilot control system according to claim 1, characterised in that the end of the valve stem (3) projecting with respect to the valve body assembly (1) is provided with a connecting rod (33), the connecting rod (33) being connectable to a control member of the working valve.
5. The pilot control system according to claim 1, wherein the valve body assembly (1) comprises a valve body (11), the valve body (11) is provided with the first oil port (17) and the second oil port (18), one end of the valve body (11) is provided with a first end cover (12), the other end of the valve body (11) is provided with a second end cover (14), one end of the valve rod (3) extends out relative to the first end cover (12), and the other end of the valve rod (3) extends out relative to the second end cover (14) and is connected with the centering assembly (2).
6. A pilot control system according to claim 5, characterised in that the side of the first end cap (12) facing the valve body (11) is provided with a first stop in the receiving chamber for limiting the displacement of the valve stem (3).
7. A pilot control system according to claim 5, characterised in that the side of the second end cap (14) facing the valve body (11) is provided with a second stop in the receiving chamber for limiting the displacement of the valve stem (3).
8. A pilot control system according to claim 1, characterized in that the centring assembly (2) comprises:
the fixing plate (21), the fixing plate (21) is U-shaped, and the fixing plate (21) is fixedly arranged on the valve body assembly (1);
the valve rod assembly comprises a first spring seat (22) and a second spring seat (23), wherein the first spring seat (22) is sleeved on the valve rod (3) and can be abutted to the valve body assembly (1), the second spring seat (23) and the first spring seat (22) are arranged at intervals along the movement direction of the valve rod (3), an elastic part (24) is arranged between the first spring seat (22) and the second spring seat (23), one end of the elastic part (24) is abutted to the first spring seat (22), and the other end of the elastic part (24) is abutted to the second spring seat (23);
one end, far away from the working valve, of the valve rod (3) is provided with a connecting piece (26), the connecting piece (26) can be abutted to one side, deviating from the first spring seat (22), of the second spring seat (23), and the valve rod (3) can drive the first spring seat (22) and the second spring seat (23) to move.
9. A pilot control system according to claim 8, characterised in that a spacer (27) is arranged between the connecting piece (26) and the second spring seat (23).
10. A pilot control system according to claim 1, characterised in that an electrical valve block (41) is arranged on the pilot handle (4), said electrical valve block (41) having said first and second control ports.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111295169.0A CN113944668A (en) | 2021-11-03 | 2021-11-03 | Pilot control system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111295169.0A CN113944668A (en) | 2021-11-03 | 2021-11-03 | Pilot control system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113944668A true CN113944668A (en) | 2022-01-18 |
Family
ID=79337621
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111295169.0A Pending CN113944668A (en) | 2021-11-03 | 2021-11-03 | Pilot control system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113944668A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103649603A (en) * | 2011-06-21 | 2014-03-19 | 戴姆勒股份公司 | Motor vehicle parking lock device having at least one locking element |
| CN106641242A (en) * | 2015-10-30 | 2017-05-10 | 长城汽车股份有限公司 | Hydraulic parking push rod assembly, automatic transmission and automobile |
| CN106678359A (en) * | 2016-12-21 | 2017-05-17 | 山推工程机械股份有限公司 | Electric-hydraulic cooperative control type speed changing system for bulldozer |
| US20190120376A1 (en) * | 2017-10-20 | 2019-04-25 | Ford Global Technologies, Llc | Transmission Park Control System |
| CN112178184A (en) * | 2020-10-15 | 2021-01-05 | 中国第一汽车股份有限公司 | Hydraulic control system of automatic transmission |
-
2021
- 2021-11-03 CN CN202111295169.0A patent/CN113944668A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103649603A (en) * | 2011-06-21 | 2014-03-19 | 戴姆勒股份公司 | Motor vehicle parking lock device having at least one locking element |
| CN106641242A (en) * | 2015-10-30 | 2017-05-10 | 长城汽车股份有限公司 | Hydraulic parking push rod assembly, automatic transmission and automobile |
| CN106678359A (en) * | 2016-12-21 | 2017-05-17 | 山推工程机械股份有限公司 | Electric-hydraulic cooperative control type speed changing system for bulldozer |
| US20190120376A1 (en) * | 2017-10-20 | 2019-04-25 | Ford Global Technologies, Llc | Transmission Park Control System |
| CN112178184A (en) * | 2020-10-15 | 2021-01-05 | 中国第一汽车股份有限公司 | Hydraulic control system of automatic transmission |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN202251182U (en) | Hand-operated pilot valve | |
| CN203856792U (en) | Deflector type shock-absorption relief valve | |
| CN108105191B (en) | Reversing valve core and manual-automatic integrated reversing valve | |
| CN108591151B (en) | Hydraulic axial plunger pump power control and positive flow control mechanism | |
| CN101576105B (en) | Flushing valve | |
| US10145368B2 (en) | Pump volume control apparatus | |
| CN113944668A (en) | Pilot control system | |
| EP2670987A1 (en) | Directional valve equipped with pressure control | |
| CN212564588U (en) | Pilot-operated type dynamic differential pressure balance valve | |
| CN211599136U (en) | Pressure cut-off valve block, closed pump assembly and engineering machinery | |
| CN210507598U (en) | Signal shut-off valve and hydraulic control system | |
| CN105626936A (en) | Ultra-high-pressure anti-pollution type water hydraulic electro-hydraulic switch valve | |
| CN203322381U (en) | Pilot-operated-type magnet changeover valve | |
| CN201973289U (en) | Two-position and five-way valve | |
| JP7349237B2 (en) | Solenoid valves and working machines | |
| CN202597828U (en) | Self-operated pressure difference controller | |
| CN108757974B (en) | Slide valve type zero leakage reversing valve | |
| CN101319729A (en) | Variable pin pilot valve | |
| CN219774983U (en) | Bidirectional electromagnetic valve | |
| CN212273180U (en) | Pilot-operated type dynamic differential pressure balance valve | |
| JP5546736B2 (en) | Discharge capacity adjusting device for swash plate type variable displacement piston pump | |
| CN114060344B (en) | Pilot handle valve, hydraulic system of excavator and control method of hydraulic system | |
| CN214367463U (en) | Hydraulic valve | |
| CN109488652B (en) | Case closed-loop control structure and hydraulic control valve | |
| CN110158697B (en) | Signal cut-off valve and hydraulic control system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |