CN110102784A - A kind of hydraulic control system of numerically controlled lathe tailstock and chuck - Google Patents
A kind of hydraulic control system of numerically controlled lathe tailstock and chuck Download PDFInfo
- Publication number
- CN110102784A CN110102784A CN201910357265.XA CN201910357265A CN110102784A CN 110102784 A CN110102784 A CN 110102784A CN 201910357265 A CN201910357265 A CN 201910357265A CN 110102784 A CN110102784 A CN 110102784A
- Authority
- CN
- China
- Prior art keywords
- oil
- valve
- hydraulic
- line
- pressure
- 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
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23B—TURNING; BORING
- B23B23/00—Tailstocks; Centres
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23B—TURNING; BORING
- B23B31/00—Chucks; Expansion mandrels; Adaptations thereof for remote control
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Fluid-Pressure Circuits (AREA)
Abstract
The hydraulic control system of a kind of numerically controlled lathe tailstock and chuck disclosed by the invention, including a power unit and two hydraulic pressure units, two hydraulic pressure units are connect by oil circuit board with power unit, power unit is for oil liquid to be input in hydraulic pressure unit, multiple hydraulic pressure units are integrated using oil circuit board, the structure of integrated hydraulic system is simplified, it is convenient for safeguarding；The tailstock of lathe and the working condition of chuck are controlled respectively by two hydraulic pressure units, and two hydraulic pressure units are mutually indepedent, ensure that the stability of entire hydraulic system.
Description
Technical field
The present invention relates to hydraulic drive field, especially a kind of hydraulic transmission control system of numerically controlled lathe.
Background technique
With the continuous development of hydraulic technique, Hydraulic Power Transmission System accounts in the Mechanical course and system call interception of numerically controlled lathe
Have critically important position, due to output power, reliable operation and easily controllable and adjust, control that hydraulic system is undertaken and
Adjustment task is only second to electrical system.
Hydraulic Power Transmission System is widely applied in the control structure of the clamping of main shaft, automatic tool changer, rotary table, but
It is that each control structure is all made of a set of independent hydraulic pressure unit and is controlled, causes traditional numerically controlled lathe hydraulic system multiple
Miscellaneous, element is mostly and at high cost, and maintenance is even more more difficult.
Problem in view of the prior art, it is necessary to existing multiple hydraulic pressure units are integrated, it is entire hydraulic to simplify
The structure of system reduces manufacturing cost.
Summary of the invention
Aiming at the problems existing in the prior art, the present invention provides the hydraulic control system of a kind of numerically controlled lathe tailstock and chuck
System, the hydraulic system structure is simple, and the element used is few, reduces the cost of hydraulic system.
The present invention is to be achieved through the following technical solutions:
A kind of hydraulic control system of numerically controlled lathe tailstock and chuck, including power unit, for controlling lathe tailstock top
First hydraulic pressure unit of tight state, for the second hydraulic pressure unit of control card chuck clamping state；
The power unit includes fuel tank, variable vane pump oil circuit board；In-line and oil return line are provided in oil circuit board, into
Oil circuit is connect by variable vane pump with fuel tank, first pressure gauge is provided on the in-line of oil circuit board, for measuring in-line
Pressure, the oil return line of oil circuit board connect by return filter with fuel tank；
The oil inlet end of first hydraulic pressure unit and the second hydraulic pressure unit is connect with the in-line of oil circuit board, oil revolving end with oil
The oil return line of road plate connects.
Preferably, return filter, the in-line of oil circuit board are additionally provided between the oil return line and fuel tank of the oil circuit board
Oil absorption filter screen is additionally provided between fuel tank.
Preferably, it is additionally provided with liquidometer on the fuel tank, for detecting the oil liquid amount in fuel tank.
Preferably, first hydraulic pressure unit includes the first check valve, the first pressure reducing valve, the first solenoid directional control valve and first
Hydraulic cylinder.
The entrance of first check valve is connected to the in-line of oiling plate, the outlet of the first check valve and entering for the first pressure reducing valve
Mouth connection, the outlet of the first pressure reducing valve are connect with the oil inlet of the first solenoid directional control valve, and two of the first solenoid directional control valve are fuel-displaced
Mouth is connected to two cavitys of first hydraulic cylinder respectively, and the oil return opening of the first solenoid directional control valve is connected to the oil return line of oiling plate.
Preferably, third pressure is additionally provided between the oil return opening of first solenoid directional control valve and the oil return line of oiling plate
Table.
Preferably, second hydraulic pressure unit includes the second pressure reducing valve, second one-way valve, the second solenoid directional control valve and second
Hydraulic cylinder.
The entrance of second pressure reducing valve is connected to the in-line of oiling plate, the outlet of the second pressure reducing valve and entering for second one-way valve
Mouth connection, the outlet of second one-way valve are connect with the oil inlet of the second solenoid directional control valve, and two of the second solenoid directional control valve are fuel-displaced
Mouth is connected to two cavitys of second hydraulic cylinder respectively, and the oil return opening of the second solenoid directional control valve is connected to the oil return line of oiling plate.
Preferably, second pressure gauge is additionally provided between the oil return opening of the first solenoid directional control valve and the oil return line of oiling plate.
Preferably, it is additionally provided on the fuel tank for the cooling device cooling to oil liquid.
Compared with prior art, the invention has the following beneficial technical effects:
The hydraulic control system of a kind of numerically controlled lathe tailstock and chuck provided by the invention, including a power unit and two
A hydraulic pressure unit, two hydraulic pressure units are connect by oil circuit board with power unit, and power unit is hydraulic for oil liquid to be input to
In unit, multiple hydraulic pressure units are integrated using oil circuit board, simplify the structure of integrated hydraulic system, it is convenient for safeguarding；
The tailstock of lathe and the working condition of chuck are controlled respectively by two hydraulic pressure units, and two hydraulic pressure units are mutually indepedent, guarantee
The stability of entire hydraulic system.
Detailed description of the invention
Fig. 1 is Hydraulic Power Transmission System schematic diagram of the present invention；
Fig. 2 is electromagnet action sequence list of the present invention.
In figure: 1. variable vane pumps, 2. motors, 3. first solenoid directional control valves, 4. first pressure reducing valves, 5. first check valves,
6. fuel tank, 7. liquidometers, 8. oil fillers, 9. oil circuit boards, 10. first pressure gauges, 11. pressure gauge change-over switches, 12. air coolers,
13. oil absorption filter screen, 14. first pressure relays, 15. return filters, 16. first hydraulic cylinders, 17. second hydraulic cylinders, 18.
Two solenoid directional control valves, 19. second pressure reducing valves, 20. second one-way valves, 21. second pressure relays, 22. second pressure gauges, 23.
Third pressure gauge.
Specific embodiment
Present invention will be described in further detail below with reference to the accompanying drawings, described to be explanation of the invention rather than limit
It is fixed.
As shown in Figure 1, a kind of hydraulic control system of numerically controlled lathe tailstock and chuck, including it is power unit, first hydraulic
Unit and the second hydraulic pressure unit.
Power unit is for providing hydraulic oil to the first hydraulic pressure unit and the second hydraulic pressure unit respectively；First hydraulic pressure unit is used
It holds out against or unclamps in control lathe tailstock；Second hydraulic pressure unit is used to control the clamping and release of chuck.
Power unit includes variable vane pump 1, motor 2, fuel tank 6, liquidometer 7 and oil circuit board 9.
Wherein, in-line and oil return line are provided in oil circuit board 9, in-line is connect by variable vane pump 1 with fuel tank 6,
Motor 2 is connect with variable vane pump 1, and the mechanical energy that motor 2 inputs is switched to hydraulic energy, provide for system with certain pressure and
The oil liquid of flow.It is additionally provided with pressure gauge change-over switch 11 between motor 2 and in-line, is provided with first pressure gauge on in-line
10, for measuring the pressure of in-line.The oil return line of oil circuit board 9 is connect by return filter 15 with fuel tank 6.
It is also connected with air cooler 12 on fuel tank 6, when work, efficient heat exchange is carried out using the cold air of forced flow, is made
Oil temperature is down to operating temperature to ensure that system is carried out continuously normal operation, and work is enable smoothly to carry out.It is additionally provided on fuel tank 6
For measuring the liquidometer 7 of fuel tank fuel quantity, oil filler 8 is provided at the top of fuel tank.
The output pressure of variable vane pump 1 can be read from first pressure gauge 11, when the pressure rise of oil liquid is to more than setting
Pressure when, pressure gauge change-over switch open, make oil liquid pressure stablize in the range of pressure values of setting.
First hydraulic pressure unit includes the first check valve 5, the first pressure reducing valve 4, first pressure relay 14, the first electromagnetic switch
Valve 3 and first hydraulic cylinder 16.
The entrance of first check valve 5 is connect with the in-line of oiling plate 9, the outlet of the first check valve 5 and the first pressure reducing valve 4
Entrance connection, the outlet of the first pressure reducing valve 4 connect with the entrance of first pressure relay 14, first pressure relay 14 out
Mouthful connect with the oil inlet of the first solenoid directional control valve 3, two oil outlets of the first solenoid directional control valve 3 respectively with first hydraulic cylinder
Left chamber is connected to right chamber, and the oil return opening of the first solenoid directional control valve 3 is connected to the oil return line of oiling plate 9, the first solenoid directional control valve 3
Third pressure gauge 23 is additionally provided between oil return opening and the oil return line of oiling plate 10.
First solenoid directional control valve 3 is Y type three-position four-way electromagnetic directional valve.
For the on-off electricity condition of the electromagnet arbitrary end of all solenoid directional control valves, hydraulic cylinder is fixed, and piston rod can
To do linear reciprocating motion to the left or to the right.When the left and right end electromagnet of solenoid directional control valve all powers off, bullet of the spool at both ends
It is in an intermediate position under spring effect.At this moment it is not communicated between the left chamber, right chamber of hydraulic cylinder, in-line and oil return line, piston is just
It is slack.
The working principle of the first hydraulic pressure unit is described in detail below.
Referring to Fig.2, when 3 right end YV2 electromagnet of the first solenoid directional control valve is powered, when YV1 is in off-position, variable blade
Pump 1 is driven by motor 2 to be rotated, by the variation of its internal seal chamber volume, by oil liquid from fuel tank 6, through oil absorption filter screen
13 suckings, and enter the first solenoid directional control valve 3 through pressure gauge change-over switch 11, check valve 5, the first pressure reducing valve 4, oil liquid is through first
The oil outlet on the right of solenoid directional control valve 3 enters the left chamber of indentation first hydraulic cylinder 16, and the left chamber of first hydraulic cylinder 16 is forced to be held
Product constantly increases, and piston is pushed to move right, and realizes the purpose that tail stock for machine tool is held out against.Meanwhile in the oil of 4 right chamber of first hydraulic cylinder
Liquid returns to the left chamber that former road flows to first hydraulic cylinder 16.
When 3 right end YV1 electromagnet of the first solenoid directional control valve is powered, when YV2 is in off-position, the first solenoid directional control valve 3
The oil outlet on the left side is opened, and oil liquid enters the right chamber of first hydraulic cylinder through the oil outlet on the left side, forces 16 right chamber of first hydraulic cylinder
Volume constantly increases, and piston is pushed to be moved to the left, and realizes the purpose that tailstock unclamps, while the oil liquid warp of 16 left chamber of first hydraulic cylinder
Oil return opening enters in oil return line, then flows back to fuel tank through filter 16.
When the left and right end electromagnet of the first solenoid directional control valve 3 all powers off, spool is under the spring effect at both ends
Between position.It is not communicated between the left chamber of first hydraulic cylinder 16, right chamber, in-line and oil return line at this time, piston is just slack.
When oil liquid pressure reaches the set pressure of first pressure relay 14, first pressure relay 14 exports tailstock and loses
Press alarm signal.
Second hydraulic pressure unit include the second pressure reducing valve 19, second one-way valve 20, the second solenoid directional control valve 18, second pressure after
Electric appliance 21 and second hydraulic cylinder 17.
The entrance of second pressure reducing valve 19 is connect with the in-line of oiling plate 9, and the outlet of the second pressure reducing valve 19 is unidirectional with second
The entrance of valve 20 connects, and the outlet of second one-way valve 20 is connect with the oil inlet of the second solenoid directional control valve 18, the second electromagnetic switch
Two oil outlets of valve 18 are connected to the left chamber of second hydraulic cylinder 17 and right chamber respectively, and second pressure relay 18 is arranged second
On 4 oil circuit of left chamber of hydraulic cylinder 17, the oil return opening of the second solenoid directional control valve 18 is connected to the oil return line of oiling plate 9, the second electromagnetism
Second pressure gauge 28 is additionally provided between the oil return opening of reversal valve 18 and the oil return line of oiling plate 10.Second pressure relay 21 is set
It sets on the in-line of the left chamber of second hydraulic cylinder 17.When oil liquid pressure reaches the set pressure of second pressure relay 21,
Second pressure relay 21 exports tailstock decompression alarm signal.
Having for second solenoid directional control valve 18 also sets up second pressure gauge 22 between mouth and the oil return line of oiling plate 9.
The working principle of second hydraulic pressure unit is identical as the working principle of the first hydraulic pressure unit.
When 18 right end YV3 electromagnet of the second solenoid directional control valve is powered, when YV4 is in off-position, oil liquid enters the second liquid
In the left chamber of cylinder pressure 17, and piston is pushed to move right, realizes the clamping of chuck.
When 18 right end YV4 electromagnet of the second solenoid directional control valve is powered, when YV3 is in off-position, oil liquid enters the second liquid
In the right chamber of cylinder pressure 17, and piston is pushed to be moved to the left, realizes the release of chuck.
The size of chuck clamping force can be adjusted by pressure reducing valve 24.
The pressure signal of oil liquid is transformed into electric signal by second pressure relay 21, when oil liquid pressure reach second pressure after
When the set pressure of electric appliance 23, chuck decompression alarm signal is issued.
Hydraulic system of the invention has the advantages that noise is low, high-efficient, at low cost using variable vane pump；Simultaneously in oil
Oil absorption filter screen is set between case and variable vane pump, and oil absorption filter screen can filter out the impurity and pollutant of oil liquid in fuel tank, have
Effect improves oil liquid degree of purity, prevents from damaging system.
It is equipped with oil filler beside fuel tank, is used to supply oil liquid to fuel tank, while fuel tank is equipped with liquidometer, for measuring
The volume of oil liquid is added.
Using oil circuit board is equipped with, connection is integrated for various hydraulic parts, convenient for searching, maintenance, is debugged.In the first He
Check valve 6, as hydraulic lock are used in second hydraulic pressure unit, i.e., oil circuit are lockked, circuit oil liquid is not allowed to have flowing.And it can reach
To higher pressure ratio, structure is simple, reliable operation, has good economy and feasibility.
Solenoid directional control valve used by the hydraulic system is Y type three-position four-way electromagnetic directional valve, and solenoid directional control valve uses
The thrust of electromagnet keeps the spool mobile, to change the flow direction of oil liquid.Solenoid directional control valve is the middle-position machine of three slide valves
Y type three-position four-way electromagnetic directional valve in energy reduces hydraulic shock when position stops for hydraulic lock and cylinder movement in Y type.
Fig. 2 is hydraulic system electromagnet action sequence list, and "+" indicates to be powered, and "-" indicates power-off.It can clearly indicate liquid
Pressure system is to the sequence of movement in the case of the power on/off of different electromagnet, as mentioned-above movement.
The above content is merely illustrative of the invention's technical idea, and this does not limit the scope of protection of the present invention, all to press
According to technical idea proposed by the present invention, any changes made on the basis of the technical scheme each falls within claims of the present invention
Protection scope within.
Claims (8)
1. a kind of hydraulic control system of numerically controlled lathe tailstock and chuck, which is characterized in that including power unit, for controlling vehicle
Tailstock frame holds out against the first hydraulic pressure unit of state and the second hydraulic pressure unit for control card chuck clamping state；
The power unit includes fuel tank (6), variable vane pump (1) and oil circuit board (9)；Oil circuit board is provided with in-line in (9)
And oil return line, in-line are connect by variable vane pump (1) with fuel tank (6), are provided with the first pressure on the in-line of oil circuit board (9)
Power table (10), for measuring the pressure of in-line, the oil return line of oil circuit board (9) is connected by return filter (15) and fuel tank (6)
It connects；
The oil inlet end of first hydraulic pressure unit and the second hydraulic pressure unit is connect with the in-line of oil circuit board (9), oil revolving end with oil
The oil return line of road plate (9) connects.
2. the hydraulic control system of numerically controlled lathe tailstock and chuck according to claim 1, which is characterized in that the oil circuit board
(9) it is additionally provided with return filter (15) between oil return line and fuel tank (6), between the in-line and fuel tank (6) of oil circuit board (9)
It is additionally provided with oil absorption filter screen (13).
3. the hydraulic control system of numerically controlled lathe tailstock and chuck according to claim 2, which is characterized in that the fuel tank
(6) liquidometer (7) are additionally provided on, for detecting the oil liquid amount in fuel tank.
4. the hydraulic control system of numerically controlled lathe tailstock and chuck according to claim 1, which is characterized in that first liquid
Pressing unit includes the first check valve (5), the first pressure reducing valve (4), the first solenoid directional control valve (3) and first hydraulic cylinder (16).
The entrance of first check valve (5) is connected to the in-line of oiling plate (9), the outlet of the first check valve (5) and the first decompression
The entrance of valve (4) connects, and the outlet of the first pressure reducing valve (4) is connect with the oil inlet of the first solenoid directional control valve (3), and the first electromagnetism changes
Be connected to respectively with two cavitys of first hydraulic cylinder to two oil outlets of valve (3), the oil return opening of the first solenoid directional control valve (3) with
The oil return line of oiling plate (10) is connected to.
5. the hydraulic control system of numerically controlled lathe tailstock and chuck according to claim 3, which is characterized in that first electricity
Third pressure gauge (23) are additionally provided between the oil return opening of magnetic reversal valve (3) and the oil return line of oiling plate (9).
6. the hydraulic control system of numerically controlled lathe tailstock and chuck according to claim 1, which is characterized in that second liquid
Pressing unit includes the second pressure reducing valve (19), second one-way valve (20), the second solenoid directional control valve (18) and second hydraulic cylinder (17)；
The entrance of second pressure reducing valve (19) is connected to the in-line of oiling plate (9), and the outlet of the second pressure reducing valve (19) is single with second
It being connected to the entrance of valve (20), the outlet of second one-way valve (20) is connect with the oil inlet of the second solenoid directional control valve (18), and second
Two oil outlets of solenoid directional control valve (18) are connected to two cavitys of second hydraulic cylinder (17) respectively, the second solenoid directional control valve
(18) oil return opening is connected to the oil return line of oiling plate (9).
7. the hydraulic control system of numerically controlled lathe tailstock and chuck according to claim 6, which is characterized in that the first electromagnetism changes
To valve (18) oil return opening and oiling plate (9) oil return line between be additionally provided with second pressure gauge (22).
8. the hydraulic control system of numerically controlled lathe tailstock and chuck according to claim 1, which is characterized in that the fuel tank
(7) it is additionally provided on for the cooling device cooling to oil liquid.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910357265.XA CN110102784A (en) | 2019-04-29 | 2019-04-29 | A kind of hydraulic control system of numerically controlled lathe tailstock and chuck |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910357265.XA CN110102784A (en) | 2019-04-29 | 2019-04-29 | A kind of hydraulic control system of numerically controlled lathe tailstock and chuck |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110102784A true CN110102784A (en) | 2019-08-09 |
Family
ID=67487528
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910357265.XA Pending CN110102784A (en) | 2019-04-29 | 2019-04-29 | A kind of hydraulic control system of numerically controlled lathe tailstock and chuck |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110102784A (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57500345A (en) * | 1980-03-26 | 1982-02-25 | ||
| CN201361927Y (en) * | 2009-03-27 | 2009-12-16 | 西安东方福星机械有限公司 | Pressure adjusting and speed adjusting circuit for pressure-flow composite proportion in concrete block machine |
| CN103807238A (en) * | 2014-03-10 | 2014-05-21 | 徐工集团工程机械股份有限公司 | Hydraulic control feeding system and hydraulic control feeding method |
| CN106762887A (en) * | 2016-12-19 | 2017-05-31 | 陕西科技大学 | The adjustable caterpillar drilling machine hydraulic system of one kind load |
| CN206636860U (en) * | 2017-04-06 | 2017-11-14 | 重庆市农业科学院 | A kind of hydraulic system of trimmer |
| CN108087350A (en) * | 2016-11-21 | 2018-05-29 | 吴丽娜 | A kind of hydraulic system of modular machine tool |
-
2019
- 2019-04-29 CN CN201910357265.XA patent/CN110102784A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57500345A (en) * | 1980-03-26 | 1982-02-25 | ||
| CN201361927Y (en) * | 2009-03-27 | 2009-12-16 | 西安东方福星机械有限公司 | Pressure adjusting and speed adjusting circuit for pressure-flow composite proportion in concrete block machine |
| CN103807238A (en) * | 2014-03-10 | 2014-05-21 | 徐工集团工程机械股份有限公司 | Hydraulic control feeding system and hydraulic control feeding method |
| CN108087350A (en) * | 2016-11-21 | 2018-05-29 | 吴丽娜 | A kind of hydraulic system of modular machine tool |
| CN106762887A (en) * | 2016-12-19 | 2017-05-31 | 陕西科技大学 | The adjustable caterpillar drilling machine hydraulic system of one kind load |
| CN206636860U (en) * | 2017-04-06 | 2017-11-14 | 重庆市农业科学院 | A kind of hydraulic system of trimmer |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN203994836U (en) | For the hydraulic control system of cuber | |
| CN108506286A (en) | A kind of driving motor directly drives the hydraulic energy-saving system of pump control cylinder with differential effect | |
| CN101543969B (en) | Hydraulic cylinder speed control system on surface grinder workbench | |
| CN102606550A (en) | Energy-saving hydraulic driving system | |
| CN110102784A (en) | A kind of hydraulic control system of numerically controlled lathe tailstock and chuck | |
| CN110081035A (en) | A kind of numerically controlled lathe hydraulic transmission control system | |
| CN207715450U (en) | Lower-moving type bender hydraulic system | |
| CN208634147U (en) | A kind of driving motor directly drives the hydraulic energy-saving system of pump control cylinder with differential effect | |
| CN110043520A (en) | A kind of hydraulic control system and its control method of numerically controlled lathe power chuck | |
| CN106735394B (en) | A kind of dual sided porous drilling hydraulic system of modular machine tool | |
| CN215059742U (en) | Movable valve group convenient to install | |
| CN209856138U (en) | Hydraulic cylinder | |
| CN104806518A (en) | Electronic control converging pump achieving variable displacement of gear pumps | |
| CN102285143B (en) | Variable displacement piston pump system for hydraulic machine | |
| CN204921504U (en) | Stamping equipment's hydraulic control device | |
| CN201616616U (en) | Full-hydraulic electric tension machine hydraulic system | |
| CN208311165U (en) | A kind of hydraulic control system of bender | |
| CN109372810B (en) | Hydraulic system of large-flow squeezer | |
| CN211715441U (en) | Hydraulic integrated valve set for realizing double-pump confluence and large-flow multi-action | |
| CN109058453B (en) | A kind of liquid transmission control method of the real-time automatic adjustment amount of changing oil | |
| CN110131225B (en) | Hydraulic control loop and method for lower die locking cylinder of bending machine | |
| CN204677518U (en) | Hydraulic system, radiation system and engineering machinery | |
| CN104763695A (en) | Hydraulic system, radiator system and engineering machinery | |
| JPH07119860A (en) | Liquid pressure direction control device and liquid pressure operating device using the control device | |
| CN221195553U (en) | Hydraulic system of bench grinder workbench |
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 | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20190809 |