CN209800385U - digital hydraulic variable pump - Google Patents
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- CN209800385U CN209800385U CN201920190008.7U CN201920190008U CN209800385U CN 209800385 U CN209800385 U CN 209800385U CN 201920190008 U CN201920190008 U CN 201920190008U CN 209800385 U CN209800385 U CN 209800385U
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Abstract
The utility model discloses a digital hydraulic variable pump, include: the variable pump comprises a variable differential cylinder, a high-pressure oil cavity, a control oil cavity, an oil return cavity and a movement mechanism, wherein the variable differential cylinder is in a step shape along the axis, one end with a small cross section area of the variable differential cylinder is connected with the high-pressure oil cavity, the other end with a large cross section area of the variable differential cylinder is connected with the control oil cavity, oil pressure in the high-pressure oil cavity and the control oil cavity is controlled by the digital servo valve, and the movement mechanism is driven to move by pushing displacement generated by the variable differential cylinder, so that flow output change is generated; the drive mechanism opens the valve body in response to an indication signal from the control unit, and the feedback mechanism closes the valve body in response to displacement of the motion mechanism to form closed-loop control. The digital hydraulic variable pump realizes the technical effects of high precision, high reliability and high rapidity variable.
Description
Technical Field
The utility model relates to a fluid drive and control field, in particular to digital hydraulic pressure variable pump.
Background
Hydraulic pumps are common power plants in the field of hydraulic transmission. To change the output flow of a hydraulic pump such as a plunger pump, it is necessary to change the flow output by pushing a swash plate via a variable mechanism to change the stroke of a piston. Conventional variable methods include manual variables and automatic variables. Wherein the manual variable is realized by utilizing a first-wheel rotating bolt, and the method is not suitable for automatic control. The automatic variable is divided into a constant pressure variable pump and a proportional variable pump, wherein the constant pressure is realized by utilizing the force given by a spring, and the swash plate automatically follows the load requirement along with the change of the flow requirement; the latter utilizes the electro-proportional valve to output different pressures to change the position of the variable mechanism, thereby outputting different flow rates. The proportional variable pump is the most advanced variable method, but the output is pressure, so that the proportional variable pump has the defects of low precision, poor repeatability, no one-to-one correspondence with signals output by a computer and the like as an analog quantity.
with the continuous improvement of the automation level, the variable requirement on the pump is higher and higher, so that a variable method which can be in one-to-one correspondence with the indication signal sent by the control unit is urgently needed, so that the variables with high precision, high reliability and rapidity are realized, and the increasing market requirement is met.
SUMMERY OF THE UTILITY MODEL
in order to solve the prior technical problem, the utility model provides a digital hydraulic pressure variable pump of high accuracy, high reliability, rapidity variable.
the utility model discloses a digital hydraulic pressure variable pump realizes through following technical scheme:
The foundation the utility model discloses, a digital hydraulic pressure variable pump is provided, include: a variable displacement pump body, a digital servo valve and a control unit, wherein,
The variable pump main body comprises a variable differential cylinder, a high-pressure oil cavity, a control oil cavity, an oil return cavity and a movement mechanism, wherein the variable differential cylinder is in a step shape along the axis, one end with a small cross section area of the variable differential cylinder is connected with the high-pressure oil cavity, the other end with a large cross section area of the variable differential cylinder is connected with the control oil cavity, oil pressures in the high-pressure oil cavity and the control oil cavity are controlled by a digital servo valve, and the movement mechanism is driven to move due to the displacement generated by pushing the variable;
The digital servo valve comprises a driving mechanism, a valve main body and a feedback mechanism, wherein the valve main body is provided with a high-pressure oil port P communicated with a high-pressure oil cavity, a control oil port A communicated to a control oil cavity and an oil return port O communicated to an oil return cavity;
the drive mechanism opens the valve body in response to an indication signal from the control unit, and the feedback mechanism closes the valve body in response to displacement of the motion mechanism to form closed-loop control.
According to an embodiment of the invention, the drive mechanism is an electric motor communicatively connected to the control unit.
According to an embodiment of the present invention, the motor may be various types of motors such as a stepping motor, a servo motor, or an ultrasonic motor.
According to an embodiment of the present invention, the valve body may be a slide valve or a rotary valve.
According to an embodiment of the present invention, the feedback mechanism may be an electrical feedback mechanism or a mechanical feedback mechanism connected to the valve main body through a nut pair, or may be other types of feedback mechanisms commonly used in the art.
According to an embodiment of the present invention, the electrical feedback mechanism may be an incremental digital sensor or an absolute position sensor, and the mechanical feedback mechanism may be a rack and pinion mechanical feedback mechanism, a crank link mechanical feedback mechanism, a ball screw mechanical feedback mechanism, or a toothed belt or chain flexible mechanical feedback mechanism.
According to an embodiment of the present invention, the moving mechanism comprises a swash plate and variable pistons driven by the swash plate to generate axial displacement.
the adjusting method of the digital hydraulic variable pump comprises the following steps:
1) the high-pressure oil cavity and the control oil cavity of the variable pump main body are respectively communicated to the high-pressure oil port P and the control oil port A, so that high-pressure oil is communicated to the high-pressure oil cavity for a long time, the control oil cavity is communicated with the control oil for a long time, and the variable differential cylinder forms floating balance;
2) the control unit sends an indication signal to a driving mechanism of the digital servo valve, the driving mechanism drives the valve main body to be opened, high-pressure oil flows into the control oil cavity, and an oil pressure difference is generated to push the variable differential cylinder to displace so as to cause the movement mechanism to move;
3) The feedback mechanism closes the valve body in response to displacement of the motion mechanism, the digital servo valve returns to the original position, and the variable differential cylinder is in the new position to restore the floating balance.
According to an embodiment of the present invention, the indication signal may be a network, a pulse or an analog, such that the driving mechanism rotates at different angular velocities by different angles.
According to an embodiment of the present invention, the angular velocity of the driving mechanism corresponds to the velocity of the variable pump variable, and the angle of rotation of the driving mechanism corresponds to the output flow of the variable pump.
due to the adoption of the technical scheme, compared with the prior art, the utility model have the following advantage:
1. The digital hydraulic variable pump has the advantages of wide variable range, high precision, good repeatability and quick response, can be completely used for directly controlling the oil cylinder or the oil motor, can realize direct speed control of the oil cylinder or the oil motor, replaces the traditional expensive and complicated servo system, greatly saves a large amount of energy loss caused by the control of the traditional servo valve, reduces the heating of the system, can save a large amount of investment, and brings practical economic and social benefits for users.
2. The digital hydraulic variable pump can be matched with engineering machinery and the like, the load sensitive function is realized, and the flow and pressure dual-following can be realized, so that the energy is saved, the consumption is reduced, and the practical effect is brought to the performance improvement of the engineering machinery.
3. The digital hydraulic variable pump can be widely applied to various high-performance hydraulic systems of various heavy equipment, national defense and military industry, engineering machinery, agricultural machinery and the like, provides a brand new choice for users, and has great significance.
drawings
Fig. 1 is a schematic diagram of a first embodiment of a digital hydraulic variable displacement pump according to the present invention;
FIG. 2 is a schematic diagram of a digital servo valve of the digital hydraulic variable displacement pump of FIG. 1;
fig. 3 is a schematic diagram of a second embodiment of a digital hydraulic variable displacement pump according to the present invention;
Fig. 4 is a schematic diagram of a third embodiment of a digital hydraulic variable displacement pump according to the present invention.
In the figure:
1 variable pump body, 11 variable differential cylinder, 12 high-pressure oil chamber, 13 control oil chamber, 14 oil return chamber, 15 motion mechanism, 151 swash plate, 152 variable piston, 2 digital servo valve, 21 drive mechanism, 22 valve body, 23 feedback mechanism, 231 feedback gear, 232 feedback rack, 233 feedback rod, 234 feedback nut, 235 ball screw, 236 swash plate position sensor, P high-pressure oil port, a control oil port and O oil return port.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the invention.
The digital hydraulic variable displacement pump according to the present invention generally includes a variable displacement pump main body 1, a digital servo valve 2, and a control unit as shown in fig. 1. The variable pump main body 1 includes a variable differential cylinder 11, a high-pressure oil chamber 12, a control oil chamber 13, a return oil chamber 14, and a moving mechanism 15. The control oil chamber 13 of the high-pressure oil chamber 12 of the variable differential cylinder 11 is stepped along the axis thereof, wherein the end with the smaller cross section of the variable differential cylinder 11 is connected to the high-pressure oil cylinder 12, and the end with the larger cross section is connected to the control oil chamber 13, and meanwhile, the pressure of the high-pressure oil which is communicated for a long time in the high-pressure oil chamber 12 is greater than the pressure of the control oil which is communicated for a long time in the control oil chamber 13, so that the variable differential cylinder 11 is in a floating balance state in a. When a pressure difference occurs between the oil in the high-pressure oil chamber 12 and the oil in the control oil chamber 13, the differential cylinder 11 is displaced therebetween, which in turn causes the movement mechanism 15 to move to generate a flow output. For example, in a plunger pump, the variable differential cylinder 11 can push the swash plate 151 to move to change the stroke of the plunger pump, so as to drive a variable piston (not shown in fig. 1) to move, thereby realizing the change of the output flow of the oil pump.
the digital servo valve 2 may comprise a drive mechanism 21, a valve body 22 and a feedback mechanism 23. The drive mechanism 21 may be a variety of motors including, but not limited to, a stepper motor, a servo motor, an ultrasonic motor. The valve body 22 may be a spool valve having a valve body and a spool coaxially disposed therein, the drive mechanism 21 may cause the spool to move axially relative to the valve body to open the valve body in response to an indication signal from the control unit, and the feedback mechanism 23 may cause the spool to move axially in an opposite direction to close the valve body in response to displacement of the differential cylinder. Alternatively, the valve body 22 may also be adapted to a spool valve having a valve housing and a valve spool disposed therein, the actuating mechanism 21 may rotate the valve spool relative to the valve housing to open the valve body in response to an instruction signal from the control unit, and the feedback mechanism 23 may rotate the valve spool relative to the valve housing to close the valve body in response to displacement of the differential cylinder. The feedback mechanism 23 may be a mechanical feedback mechanism connected to the valve body 22 by a nut pair, including but not limited to a rack and pinion mechanical feedback mechanism, a crank link mechanical feedback mechanism, a ball screw mechanical feedback mechanism, or a flexible mechanical feedback mechanism such as a toothed belt or chain, etc. Alternatively, the feedback mechanism 23 may also be an electrical feedback mechanism communicatively coupled to the valve body 22, including but not limited to incremental digital sensors and absolute position sensors.
The control unit is used to send an indication signal to the drive mechanism 21 to open the valve body 22. Thus, the control unit may be a device capable of sending an indication signal. Alternatively, the drive mechanism 21 may be indirectly controlled by bus control, network control, or the like, in addition to direct control by the control unit. The indicator signal includes, but is not limited to, a network, pulses, or analog quantities that cause the drive mechanism to rotate different angles at different angular velocities. The angular speed of the driving mechanism corresponds to the variable speed of the variable pump, and the rotating angle of the driving mechanism corresponds to the output flow of the variable pump.
The adjusting method of the digital hydraulic variable pump comprises the following steps:
1) The high-pressure oil chamber 12 and the control oil chamber 13 of the variable pump main body 1 are respectively communicated to the high-pressure oil port P and the control oil port A, so that the high-pressure oil chamber 12 is communicated with high-pressure oil for a long time, the control oil chamber 13 is communicated with control oil for a long time, and the variable differential cylinder 11 forms floating balance;
2) the control unit sends an indication signal to a driving mechanism 21 of the digital servo valve 2, the driving mechanism 21 drives to open a valve main body 22, high-pressure oil flows into a control oil cavity 13, and an oil pressure difference is generated to push a variable differential cylinder 11 to displace so as to cause a movement mechanism 13 to move;
3) the feedback mechanism 23 closes the valve body 22 in response to the displacement of the moving mechanism 15, the digital servo valve 2 returns to the original position, and the variable differential cylinder 11 is brought to the new position to restore the floating balance.
Specifically, in the embodiment shown in fig. 1-2, the valve body 2 is provided with a high-pressure port P, a control port a, and an oil return port O. High-pressure oil of the digital hydraulic variable pump is led out from a high-pressure oil cavity 12 (the interior of the high-pressure oil cavity is communicated) and sent to a high-pressure oil port P of a digital servo valve 2, taking a digital servo slide valve as an example, and an oil return port O directly returns to an oil return cavity of the digital hydraulic variable pump through the interior of the high-pressure oil port P. The control port a of the digital servo valve 2 is communicated to the control oil chamber 13 of the variable differential cylinder 11 which moves the pushing movement mechanism 15. At this time, the variable differential cylinder 11 forms a differential cylinder in which the high-pressure oil chamber 12 is communicated with high-pressure oil for a long time and the control oil chamber 13 is communicated with control oil, so that a floating balance state is formed. When the drive mechanism of the digital servo valve 2 receives the indication signal, it generates a rotational movement that rotates the spool on the valve body 22, the head of the spool having threads that engage the nut sleeve in the feedback nut 234. At this time, the nut sleeve does not move, so that the valve core generates an axial movement under the action of the screw pair, the valve port is opened, a passage is formed between the high-pressure oil port P and the control oil port a, high-pressure oil is sent to the control oil chamber 13, the control oil chamber 13 is communicated with the high-pressure oil to enable the variable differential cylinder 11 to lose balance and generate axial movement, the variable swash plate 151 is pushed to move to change the movement stroke of the plunger pump, and therefore the variable piston 152 (see fig. 3) is driven to move, and the change of the output flow of the oil pump is achieved. While the variable differential cylinder 11 moves axially, the feedback mechanism 23 composed of the feedback gear 231, the feedback rack 232, the feedback rod 233 and the feedback nut 234 feeds back to the nut pair of the digital servo valve 2, and the nut generates a movement in the same direction as the rotation direction of the spool, thereby pushing the spool back to the original closed state, so that the variable differential cylinder 11 is in the rebalancing state at the new position, and the one-time tracking of the indication signal by the variable differential cylinder 11 is completed. When the indication signal is continuously sent, the variable cylinder will continuously move until the indication signal stops being sent, and the variable differential cylinder 11 stops after the stroke corresponding to the indication signal is finished. And vice versa. Therefore, the flow output of the oil pump is completely controlled by the instruction signal instruction output by the control device, and the angular speed of various motors in different forms such as a stepping motor, a servo motor or an ultrasonic motor of the control unit is the speed of the variable differential cylinder 11, namely the flow change speed. The angle of various motors in different forms such as a stepping motor, a servo motor or an ultrasonic motor of the control unit is the stroke of the variable differential cylinder 11, namely the final size of the flow, so that the variable pump can receive the accurate variable control of the command of the control device for sending an indication signal in real time.
In the embodiment shown in fig. 3, this is achieved by the direct connection of the digital servo valve 2 with the reverse drive of a ball screw 235 mounted to the variable piston 152 by a feedback nut 234.
In the embodiment shown in FIG. 4, feedback is accomplished using a swashplate position sensor 236 communicatively coupled to digital servo valve 2 in place of feedback nut 234. In this embodiment, the digital servo valve 2 can be installed anywhere, the electric signal of the swash plate position sensor 236 is sent to the control unit, the position of the variable swash plate 151 is detected, and then the digital servo valve 2 is directly controlled by the digital signal, so that the position of the variable swash plate 151 of the electric closed loop can be arbitrarily controlled, thereby changing the flow output.
The utility model discloses an indicating signal that digital hydraulic pressure variable pump adopted the control unit to send, the speed and the stroke of direct accurate control variable mechanism, the angular velocity of the various motors of different forms such as the step motor of the control unit, servo motor or ultrasonic motor is corresponding with the speed that promotes variable sloping cam plate hydro-cylinder, and the angle of the various motors of different forms such as the step motor of the control unit, servo motor or ultrasonic motor is corresponding with the stroke of variable hydro-cylinder. For example, when the motor rotates 1000 times at 0.1 second for 0.36 degrees each time, the variable differential cylinder 11 moves 20 mm, thereby rapidly and precisely controlling the precise flow output of the variable displacement pump.
The above embodiments only express the embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.
Claims (7)
1. A digital hydraulic variable displacement pump, comprising: a variable displacement pump body, a digital servo valve and a control unit, wherein,
The variable pump main body comprises a variable differential cylinder, a high-pressure oil cavity, a control oil cavity, an oil return cavity and a movement mechanism, wherein the variable differential cylinder is in a step shape along the axis, one end with a small cross section area of the variable differential cylinder is connected with the high-pressure oil cavity, the other end with a large cross section area of the variable differential cylinder is connected with the control oil cavity, oil pressures in the high-pressure oil cavity and the control oil cavity are controlled by the digital servo valve, and the movement mechanism is driven to move due to the displacement generated by the variable differential cylinder, so that the change of flow output is;
The digital servo valve comprises a driving mechanism, a valve main body and a feedback mechanism, wherein the valve main body is provided with a high-pressure oil port P communicated with the high-pressure oil cavity, a control oil port A communicated with the control oil cavity and an oil return port O communicated with the oil return cavity;
The drive mechanism opens the valve body in response to an indication signal from the control unit, and the feedback mechanism closes the valve body in response to displacement of the motion mechanism to form a closed loop control.
2. the digital hydraulic variable displacement pump of claim 1 wherein the drive mechanism is an electric motor communicatively connected to the control unit.
3. The digital hydraulic variable displacement pump of claim 2 wherein the motor is a stepper motor, a servo motor or an ultrasonic motor.
4. The digital hydraulic variable displacement pump according to claim 1, wherein the valve body is a spool valve or a rotary valve.
5. The digital hydraulic variable displacement pump according to claim 1, wherein the feedback mechanism is an electrical feedback mechanism or a mechanical feedback mechanism connected to the valve body by a nut pair.
6. The digital hydraulic variable displacement pump according to claim 5, wherein the electrical feedback mechanism is an incremental digital sensor or an absolute position sensor and the mechanical feedback mechanism is a rack and pinion mechanical feedback mechanism, a crank link mechanical feedback mechanism, a ball screw mechanical feedback mechanism, or a toothed belt or chain flexible mechanical feedback mechanism.
7. The digital hydraulic variable displacement pump of claim 1, wherein the motion mechanism comprises a swash plate and variable pistons driven by the swash plate to produce axial displacement.
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| CN201920190008.7U CN209800385U (en) | 2019-02-11 | 2019-02-11 | digital hydraulic variable pump |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109681482A (en) * | 2019-02-11 | 2019-04-26 | 北京亿美博科技有限公司 | A kind of digital hydraulic variable pump and its adjusting method |
| CN111923883A (en) * | 2020-07-15 | 2020-11-13 | 中国第一汽车股份有限公司 | Brake system matching analysis method and system considering active braking function |
| CN112727814A (en) * | 2020-12-28 | 2021-04-30 | 浙江大学 | Variable-speed and variable-displacement single-rod electro-hydraulic actuator |
-
2019
- 2019-02-11 CN CN201920190008.7U patent/CN209800385U/en active Active
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109681482A (en) * | 2019-02-11 | 2019-04-26 | 北京亿美博科技有限公司 | A kind of digital hydraulic variable pump and its adjusting method |
| CN109681482B (en) * | 2019-02-11 | 2024-04-19 | 北京亿美博科技有限公司 | Digital hydraulic variable pump and adjusting method thereof |
| CN111923883A (en) * | 2020-07-15 | 2020-11-13 | 中国第一汽车股份有限公司 | Brake system matching analysis method and system considering active braking function |
| CN111923883B (en) * | 2020-07-15 | 2022-11-11 | 中国第一汽车股份有限公司 | Brake system matching analysis method and system considering active braking function |
| CN112727814A (en) * | 2020-12-28 | 2021-04-30 | 浙江大学 | Variable-speed and variable-displacement single-rod electro-hydraulic actuator |
| CN112727814B (en) * | 2020-12-28 | 2022-06-28 | 浙江大学 | Variable-speed and variable-displacement single-rod electro-hydraulic actuator |
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