CN111392659A - Variable amplitude control system - Google Patents
Variable amplitude control system Download PDFInfo
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- CN111392659A CN111392659A CN202010299043.XA CN202010299043A CN111392659A CN 111392659 A CN111392659 A CN 111392659A CN 202010299043 A CN202010299043 A CN 202010299043A CN 111392659 A CN111392659 A CN 111392659A
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B66—HOISTING; LIFTING; HAULING
- B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
- B66F11/00—Lifting devices specially adapted for particular uses not otherwise provided for
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- 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
- F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
- F15B11/08—Servomotor systems without provision for follow-up action; Circuits therefor with only one servomotor
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- General Engineering & Computer Science (AREA)
- Fluid-Pressure Circuits (AREA)
Abstract
A variable amplitude control system. The problems of unreliable control and poor stability of the conventional variable amplitude system are solved. The hydraulic control system comprises an oil tank, a hydraulic pump, a first reversing valve, a second reversing valve, a proportional flow valve and a working oil cylinder, wherein the working oil cylinder comprises a rodless cavity and a rod cavity; the hydraulic pump is used for inputting the hydraulic oil in the oil tank into a rodless cavity or a rod cavity of the working oil cylinder through the first reversing valve; the first reversing valve is provided with a first position connected with the rodless cavity of the working oil cylinder through a second reversing valve, a second position with a middle stop and a third position connected with the rod cavity of the working oil cylinder; the second reversing valve is provided with a first position for communicating the rodless position of the working oil cylinder and a second position for stopping the working oil cylinder; and the proportional flow valve is communicated with the rodless cavity of the working oil cylinder through the second reversing valve when the first reversing valve is positioned at the third position, and is matched with the oil return flow of the rodless cavity and the oil inlet flow of the rod cavity. The invention has the advantages of simple structure, stable performance, long service life and the like.
Description
Technical Field
The invention relates to a variable amplitude control system.
Background
Along with the requirement of the building industry on efficiency improvement, the demand of aerial work platform equipment is more and more extensive. It is often used to perform high-altitude operations such as exterior wall maintenance, high-altitude buildings and street lamp installation. The existing aerial work platform product amplitude-variable lowering system has two amplitude-variable lowering modes of gravity falling and power falling, and the two amplitude-variable lowering modes respectively have own advantages and disadvantages.
In a system under gravity, a hydraulic pump supplies pressure oil, an electromagnetic valve is reversed, the electromagnetic valve is positioned at the right position, the pressure oil passes through a reversing valve, a one-way valve is opened to enter a rodless cavity of an oil cylinder, and the oil cylinder moves upwards to realize the lifting of amplitude-variable action; when the electromagnetic valve is cut off, the oil cylinder can be stopped at a certain designated position; when the amplitude of the hydraulic oil is lower than the amplitude of the hydraulic oil, the load applies acting force to the oil cylinder under the action of gravity, and the hydraulic oil in the rodless cavity of the oil cylinder flows back to the oil tank through the electromagnetic valve to realize the falling of the amplitude-variable oil cylinder. The gravity transfer system has the advantages that the amplitude-variable oil cylinder can fall under the condition that the vehicle engine is not started, so that the energy consumption is effectively reduced; meanwhile, the gravity of the variable-amplitude oil cylinder is transferred to be influenced by the load, when the load is large, the acting force applied to the variable-amplitude oil cylinder by the gravity is large, the falling speed is relatively high, potential safety hazards exist, when the load is small, the acting force applied to the variable-amplitude oil cylinder by the gravity is small, the falling speed is very low, and the working efficiency is reduced.
In a power lowering system (refer to the attached figure 1), a hydraulic pump 2 supplies pressure oil, a proportional valve 3 is reversed to the left position, the pressure oil reaches a balance valve 4 through an A port of the proportional valve 3 and enters a rodless cavity of an oil cylinder 6 through the balance valve 4, meanwhile, the pressure oil opens the balance valve 5 through a control port of the balance valve 5, and hydraulic oil in a rod cavity of the oil cylinder 6 flows back to an oil tank through the balance valve 5 and a B port of the proportional valve 3 to realize the extension of the oil cylinder. The hydraulic pump 2 supplies pressure oil, the proportional valve 3 is reversed to the right position, the pressure oil reaches the balance valve 5 through the port B of the proportional valve 3 and enters the rod cavity of the oil cylinder 6 through the balance valve 5, meanwhile, the pressure oil opens the balance valve 4 through the control port of the balance valve 4, hydraulic oil in the rodless cavity of the oil cylinder 6 flows back to the oil tank through the balance valve 4 and the port A of the proportional valve 3, and retraction of the oil cylinder is achieved. The power lowering system has the advantages and disadvantages that certain pressure oil is needed to open the balance valve on the corresponding oil return path through the control port in the extending and retracting processes of the oil cylinder, so that the energy consumption is increased; meanwhile, in the process of amplitude-variable lowering, the load acting force changes greatly, so that the balance valve is easy to shake, and the amplitude-variable oil cylinder falls unstably.
Disclosure of Invention
The invention provides a variable amplitude control system, aiming at solving the problems of unreliable control and poor stability of the existing variable amplitude system in the background technology.
The technical scheme of the invention is as follows: a variable amplitude control system comprises an oil tank, a hydraulic pump, a first reversing valve, a second reversing valve, a proportional flow valve and a working oil cylinder, wherein the working oil cylinder comprises a rodless cavity and a rod cavity;
the hydraulic pump is used for inputting the hydraulic oil in the oil tank into a rodless cavity or a rod cavity of the working oil cylinder through the first reversing valve;
the first reversing valve is provided with a first position connected with the rodless cavity of the working oil cylinder through a second reversing valve, a second position with a middle stop and a third position connected with the rod cavity of the working oil cylinder;
the second reversing valve is provided with a first position for communicating the rodless position of the working oil cylinder and a second position for stopping the working oil cylinder;
and the proportional flow valve is communicated with the rodless cavity of the working oil cylinder through the second reversing valve when the first reversing valve is positioned at the third position, and is matched with the oil return flow of the rodless cavity and the oil inlet flow of the rod cavity.
As an improvement of the invention, the second reversing valve has a first state of receiving hydraulic oil of the hydraulic pump and inputting the hydraulic oil into the rodless cavity of the working oil cylinder when in the first position and a second state of connecting the rodless cavity of the working oil cylinder with the oil tank through the proportional flow valve when in the third position.
As a further improvement of the invention, the hydraulic control system is also provided with a low-pressure overflow valve which is arranged between a rod cavity of the working oil cylinder and the oil tank.
As a further improvement of the invention, the electric proportional overflow valve is also arranged and is arranged between the rod cavity of the working oil cylinder and the oil tank.
As a further improvement of the invention, a one-way valve is arranged between the first reversing valve and the second reversing valve.
As a further improvement of the invention, the proportional flow valve intercepts the pressure oil between the one-way valve and the second reversing valve and is connected with the oil tank when the first reversing valve is at the third position.
As a further improvement of the invention, the proportional flow valve comprises a flow reversing valve and a compensating valve, wherein the flow reversing valve receives pressure oil at the rodless cavity of the working oil cylinder and is connected with an oil tank through the compensating valve.
As a further improvement of the invention, an oil inlet of the compensation valve is communicated with an oil outlet of the flow reversing valve, pressure oil at an oil outlet of the flow reversing valve is connected with a spring cavity of the compensation valve, and a control cavity of the compensation valve receives the pressure oil at a rodless cavity of the working oil cylinder and controls an opening of the compensation valve under the mutual cooperation and combined action of the pressure oil and the pressure in the spring cavity of the compensation valve.
As a further improvement of the invention, the spring cavity of the flow reversing valve and the control cavity of the flow reversing valve both receive pressure oil at the rodless cavity of the working oil cylinder.
As a further improvement of the invention, the first reversing valve is a proportional reversing valve.
The invention has the advantages that the first reversing valve and the second reversing valve are arranged, the product can reliably supply oil or drain oil for the working oil cylinder through the reversing of the first reversing valve and the second reversing valve, and the arrangement of the proportional flow valve ensures that the lower part of the system is more stable and reliable. The invention solves the problems of low gravity lowering speed, high power lowering energy consumption and easy shake, simultaneously enables the system to realize the lifting of the working platform efficiently, energy-saving and stably, and has the advantages of simple structure, reliable action, high efficiency, energy saving, stable performance, long service life and the like.
Drawings
Fig. 1 is a hydraulic schematic diagram of a conventional power lowering system.
Fig. 2 is a hydraulic schematic of an embodiment of the present invention.
In the figure, 1, a fuel tank; 2. a hydraulic pump; 3. a first direction changing valve; 4. a one-way valve; 5. a second directional control valve; 6. a working oil cylinder; 61. a rodless cavity; 62. a rod cavity; 7. a low pressure relief valve; 8. a proportional flow valve; 81. a flow reversing valve; 82. a compensation valve.
Detailed Description
The embodiments of the invention will be further described with reference to the accompanying drawings in which:
as shown in fig. 2, the variable amplitude control system comprises an oil tank 1, a hydraulic pump 2, a first reversing valve 3, a second reversing valve 5, a proportional flow valve 8 and a working oil cylinder 6, wherein the working oil cylinder comprises a rodless cavity 61 and a rod cavity 62;
the hydraulic pump is used for inputting the hydraulic oil in the oil tank into a rodless cavity or a rod cavity of the working oil cylinder through the first reversing valve;
the first reversing valve is provided with a first position connected with the rodless cavity of the working oil cylinder through a second reversing valve, a second position with a middle stop and a third position connected with the rod cavity of the working oil cylinder;
the second reversing valve is provided with a first position for communicating the rodless position of the working oil cylinder and a second position for stopping the working oil cylinder;
and the proportional flow valve is communicated with the rodless cavity of the working oil cylinder through the second reversing valve when the first reversing valve is positioned at the third position, and is matched with the oil return flow of the rodless cavity and the oil inlet flow of the rod cavity. The invention has the advantages that the first reversing valve and the second reversing valve are arranged, the product can reliably supply oil or drain oil for the working oil cylinder through the reversing of the first reversing valve and the second reversing valve, and the arrangement of the proportional flow valve ensures that the lower part of the system is more stable and reliable. The invention solves the problems of low gravity lowering speed, high power lowering energy consumption and easy shake, simultaneously enables the system to realize the lifting of the working platform efficiently, energy-saving and stably, and has the advantages of simple structure, reliable action, high efficiency, energy saving, stable performance, long service life and the like.
In the amplitude-variable control system, pressure oil is supplied by a hydraulic pump 2, a first reversing valve 3 is reversed to a left position, the pressure oil passes through an A port of the first reversing valve 3, a one-way valve 4 is opened, a second reversing valve 5 works at a right position, the pressure oil enters a rodless cavity 61 of a working oil cylinder 6 through the second reversing valve 5, oil liquid in a rod cavity 62 of the working oil cylinder 6 flows back to an oil tank 1 through the first reversing valve 3, and the working oil cylinder extends out at the moment, namely the amplitude-variable action is lifted; by changing the control current of the first reversing valve 3, the flow of the feeding system can be controlled, and the lifting speed can be changed. Specifically, the first direction valve 3 is a proportional direction valve. More specifically, the first reversing valve is a hydraulic control proportional reversing valve or an electric control proportional reversing valve. More specifically, the first reversing valve is a three-position, four-way reversing valve.
In the amplitude-variable control system, after the working oil cylinder extends to the right position, the second reversing valve is positioned at the right position, and the first reversing valve is positioned at the middle position and does not supply oil, so that high-position locking of the working platform is realized, and the working of workers is facilitated. When the lowering action is executed, the hydraulic pump 2 supplies pressure oil, the first reversing valve 3 is reversed to the right position for working, and the pressure oil enters the rod cavity 62 of the working oil cylinder 6 through the port B of the first reversing valve 3; the second reversing valve 5 is reversed to the left position to work, the proportional flow valve 8 is reversed to the right position to work, and at the moment, the hydraulic oil in the rodless cavity 61 of the working oil cylinder 6 flows back to the oil tank through the second reversing valve 5 and the proportional flow valve 8; the retraction of the working oil cylinder 6, namely the lowering of the amplitude is realized; a proportional flow valve 8 is arranged between the second reversing valve 5 and the one-way valve 4, the flow of the proportional flow valve 8 can be controlled by changing the current, and the matching of the oil return of the rodless cavity and the oil inlet flow of the rod cavity of the balance working oil cylinder 6 is achieved, so that the retraction stability of the oil cylinder is ensured, and the problem of amplitude-variable lowering shaking is solved. The low-pressure overflow valve 7 is arranged between the first reversing valve 3 and the rod cavity 62 of the working oil cylinder 6, the set pressure of the low-pressure overflow valve 7 is very low, the working oil cylinder is controlled to be lowered by the system under very low constant pressure, and the energy consumption of the system can be effectively reduced. Meanwhile, the low-pressure overflow valve 7 can be replaced by an electric proportional overflow valve, the pressure set value of the overflow valve can be adjusted by changing the control current, under the working condition that the amplitude of the fluctuation bears a large load, the set value of the overflow valve is adjusted by changing the current at the moment, the working pressure of the system is reduced, and if the load is large enough, the overflow value can be set to be zero, so that the amplitude of the fluctuation is completely released by the gravity.
The second reversing valve has a first state of receiving hydraulic oil of the hydraulic pump and inputting the hydraulic oil into the rodless cavity of the working oil cylinder when in the first position and a second state of connecting the rodless cavity of the working oil cylinder with the oil tank through the proportional flow valve when in the third position. The structure can be realized through the state change of the second reversing valve, and the telescopic action of the working oil cylinder ensures that the product acts stably and reliably.
The invention is also provided with a low-pressure overflow valve 7 which is arranged between the rod cavity of the working oil cylinder and the oil tank. The invention is also provided with an electric proportional overflow valve (not shown in the drawing), and the electric proportional overflow valve is arranged between the rod cavity of the working oil cylinder and the oil tank. The low-pressure overflow valve or the electric proportional overflow valve is arranged, so that the working oil cylinder is controlled to be lowered under the constant pressure of a product, and the energy consumption of the system can be effectively reduced. The electric proportional overflow valve can adjust the pressure set value of the overflow valve by changing the control current, and under the working condition that the amplitude of the pressure set value bears the large load, the overflow valve is under the action of gravity, the set value of the overflow valve is reduced by changing the current at the moment, the working pressure of the system is reduced, if the load is large enough, the overflow value can be set to be zero, the amplitude of the pressure set value is completely transferred by the gravity, the energy consumption is reduced, the amplitude of the pressure set value is stable and controllable when the pressure set value is transferred.
A one-way valve 4 is arranged between the first reversing valve and the second reversing valve. Specifically, the proportional flow valve intercepts pressure oil between the one-way valve and the second reversing valve when the first reversing valve is at the third position and is connected with an oil tank. By the structure, the working oil cylinder can reliably drain oil through the proportional flow valve, so that the system can be reliably lowered.
The proportional flow valve 8 comprises a flow reversing valve 81 and a compensating valve 82, and the flow reversing valve receives pressure oil at the rodless cavity of the working oil cylinder and is connected with an oil tank through the compensating valve. Specifically, a spring cavity of the flow reversing valve and a control cavity of the flow reversing valve both receive pressure oil at a rodless cavity of the working oil cylinder. More specifically, an oil inlet of the compensation valve is communicated with an oil outlet of the flow reversing valve, pressure oil at an oil outlet of the flow reversing valve is connected with a spring cavity of the compensation valve, and a control cavity of the compensation valve receives the pressure oil at a rodless cavity of the working oil cylinder and the pressure in the spring cavity of the compensation valve to cooperate with each other to control an opening of the compensation valve. The structure can balance the oil return of the rodless cavity and the oil inlet flow of the rod cavity of the working oil cylinder by changing the flow of the current control proportional flow valve, thereby ensuring the retraction stability of the working oil cylinder and eliminating the problem of shaking in the amplitude-variable lowering process. More specifically, the output flow can be controlled through the interaction of the compensating valve and the flow reversing valve, so that the working oil cylinder is more stable when falling. More specifically, the flow reversing valve controls the opening size in an electric control mode.
In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral 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 addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.
The skilled person should understand that: although the invention has been described in terms of the above specific embodiments, the inventive concept is not limited thereto and any modification applying the inventive concept is intended to be included within the scope of the patent claims.
Claims (10)
1. A variable amplitude control system is characterized by comprising an oil tank, a hydraulic pump, a first reversing valve, a second reversing valve, a proportional flow valve and a working oil cylinder, wherein the working oil cylinder comprises a rodless cavity and a rod cavity;
the hydraulic pump is used for inputting the hydraulic oil in the oil tank into a rodless cavity or a rod cavity of the working oil cylinder through the first reversing valve;
the first reversing valve is provided with a first position connected with the rodless cavity of the working oil cylinder through a second reversing valve, a second position with a middle stop and a third position connected with the rod cavity of the working oil cylinder;
the second reversing valve is provided with a first position for communicating the rodless position of the working oil cylinder and a second position for stopping the working oil cylinder;
and the proportional flow valve is communicated with the rodless cavity of the working oil cylinder through the second reversing valve when the first reversing valve is positioned at the third position, and is matched with the oil return flow of the rodless cavity and the oil inlet flow of the rod cavity.
2. The variable amplitude control system of claim 1 wherein the second directional control valve has a first state in which it receives hydraulic fluid from the hydraulic pump and feeds it to the rodless chamber of the working cylinder when in the first position and a second state in which it connects the rodless chamber of the working cylinder to the tank via a proportional flow valve when in the third position.
3. The variable amplitude control system according to claim 1, further comprising a low pressure overflow valve disposed between the rod chamber of the working cylinder and the tank.
4. The variable amplitude control system according to claim 1, further comprising an electric proportional relief valve, wherein the electric proportional relief valve is arranged between the rod cavity of the working cylinder and the oil tank.
5. The variable amplitude control system as claimed in claim 1, wherein a check valve is provided between the first directional control valve and the second directional control valve.
6. The variable amplitude control system as set forth in claim 5, wherein the proportional flow valve intercepts pressurized oil between the check valve and the second directional valve and is connected to the tank when the first directional valve is in the third position.
7. The variable amplitude control system according to claim 1, wherein the proportional flow valve comprises a flow reversing valve and a compensating valve, and the flow reversing valve receives pressure oil at the rodless cavity of the working oil cylinder and is connected with an oil tank through the compensating valve.
8. The variable amplitude control system according to claim 7, wherein an oil inlet of the compensation valve is communicated with an oil outlet of the flow reversing valve, pressure oil at an oil outlet of the flow reversing valve is connected with a spring cavity of the compensation valve, and a control cavity of the compensation valve receives the pressure oil at a rodless cavity of the working oil cylinder and the pressure in the spring cavity of the compensation valve to cooperate with each other to control an opening of the compensation valve.
9. The variable amplitude control system according to claim 7, wherein the spring chamber of the flow reversing valve and the control chamber of the flow reversing valve both receive pressure oil at the rodless chamber of the working cylinder.
10. The luffing control system of claim 1 wherein the first directional valve is a proportional directional valve.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010299043.XA CN111392659A (en) | 2020-04-16 | 2020-04-16 | Variable amplitude control system |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010299043.XA CN111392659A (en) | 2020-04-16 | 2020-04-16 | Variable amplitude control system |
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| CN111392659A true CN111392659A (en) | 2020-07-10 |
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| CN202010299043.XA Pending CN111392659A (en) | 2020-04-16 | 2020-04-16 | Variable amplitude control system |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112922915A (en) * | 2021-02-08 | 2021-06-08 | 徐工消防安全装备有限公司 | Platform gravity descending control system and method |
| CN113790182A (en) * | 2021-09-22 | 2021-12-14 | 湖南星邦智能装备股份有限公司 | Cantilever crane self-weight retraction control system and control method |
| CN113819097A (en) * | 2021-09-30 | 2021-12-21 | 浙江三一装备有限公司 | Control valve group, hydraulic system, engineering machinery and arm support overturning control method of engineering machinery |
| CN114215824A (en) * | 2021-11-11 | 2022-03-22 | 浙江三一装备有限公司 | Method for acquiring control range of proportional valve, test system and hydraulic system |
| CN117303232A (en) * | 2023-09-20 | 2023-12-29 | 中联重科股份有限公司 | Telescopic hydraulic system, telescopic mechanism and automobile crane |
-
2020
- 2020-04-16 CN CN202010299043.XA patent/CN111392659A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112922915A (en) * | 2021-02-08 | 2021-06-08 | 徐工消防安全装备有限公司 | Platform gravity descending control system and method |
| CN113790182A (en) * | 2021-09-22 | 2021-12-14 | 湖南星邦智能装备股份有限公司 | Cantilever crane self-weight retraction control system and control method |
| CN113790182B (en) * | 2021-09-22 | 2024-04-19 | 湖南星邦智能装备股份有限公司 | Arm support dead weight retraction control system and control method |
| CN113819097A (en) * | 2021-09-30 | 2021-12-21 | 浙江三一装备有限公司 | Control valve group, hydraulic system, engineering machinery and arm support overturning control method of engineering machinery |
| CN113819097B (en) * | 2021-09-30 | 2023-07-04 | 浙江三一装备有限公司 | Control valve group, hydraulic system, engineering machinery and arm support overturning control method of engineering machinery |
| CN114215824A (en) * | 2021-11-11 | 2022-03-22 | 浙江三一装备有限公司 | Method for acquiring control range of proportional valve, test system and hydraulic system |
| CN114215824B (en) * | 2021-11-11 | 2023-06-09 | 浙江三一装备有限公司 | Method for acquiring control range of proportional valve, test system and hydraulic system |
| CN117303232A (en) * | 2023-09-20 | 2023-12-29 | 中联重科股份有限公司 | Telescopic hydraulic system, telescopic mechanism and automobile crane |
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