CN203146744U - Pulse width modulation hydraulic stepless speed regulator - Google Patents
Pulse width modulation hydraulic stepless speed regulator Download PDFInfo
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- CN203146744U CN203146744U CN 201320183416 CN201320183416U CN203146744U CN 203146744 U CN203146744 U CN 203146744U CN 201320183416 CN201320183416 CN 201320183416 CN 201320183416 U CN201320183416 U CN 201320183416U CN 203146744 U CN203146744 U CN 203146744U
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- speed
- speed switch
- hydraulic
- way valve
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Abstract
The utility model discloses a pulse width modulation hydraulic stepless speed regulator which comprises a hydraulic pipeline. The pulse width modulation hydraulic stepless speed regulator is characterized in that a metering pump, high-speed switch valves, a one-way valve, a hydraulic motor and an energy accumulator are arranged on the hydraulic pipeline, the high-speed switch valves are connected at two ends of the metering pump in parallel, the one-way valve is connected with the high-speed switch valves in series, the energy accumulator is arranged behind the one-way valve, and the hydraulic motor is arranged between the one-way valve and the energy accumulator. According to the pulse width modulation hydraulic stepless speed regulator, the dynamic response of a valve control speed regulating system is fast, the low-speed state is more stable, the structure is simple, and cost is low; due to the fact that the one-way valve is additionally arranged on an oil inlet of the motor, influence on the pressure of the inner cavity of the motor is reduced in a speed reducing process, and hydraulic impact caused by soaring of bypass flow due to the increasing of pressure in the cavity of the motor is reduced when disturbing load exists; spill loss power is small, system temperature rise is low, the structure is simple, and cost is low.
Description
Technical field
The utility model relates to a kind of oil hydraulic motor speed control system, especially oil hydraulic motor pulsewidth modulation hydraulic pressure
Stepless speed variator.
Background technique
In the existing speed change gear, comprise mechanical stepless transmission, hydraulic continuously variable transmission, the hydraulic mechanical type stepless speed variator is used in every field respectively.
Existing hydraulic motor stepless speed changer, citation form mainly contain volumetric speed control and throttle grverning two classes.The typical structure of speed control system with adjustable displacement is the pump control hydraulic motor system, and it comes motor output to control by changing the variable pump delivery.Therefore it is little that this controlling method has power loss, and the advantage that efficient is high has obtained application in a lot of occasions, and especially in the high-power system, but it has the low speed instability, the shortcoming that dynamic characteristic is relatively poor.Throttle grverning is to regulate the flow that enters oil hydraulic motor by the aperture of regulating servovalve.It is fast that thereby the speed of control motor, the characteristics of this system are responses, and efficient is low, is applicable to the occasion that dynamic characteristic is high.Yet, for high power hydraulic motor speed varying system, traditional valve control form can't solve system's temperature rise, the difficult problem of heat radiation that spill losses causes, therefore must adopt the higher volume control system of efficient to solve the big problem of heating value, though but volume control system efficient is higher, but dynamic performance is relatively poor, is unsuitable for high-precision occasion.Therefore the valve pump also having occurred jointly controls the hydraulic motor stepless speed variator system, and this system dynamic characteristic is good, the efficient height, but control is complicated, and cost cost height is difficult for promoting the popularization use.Only under demanding special occasions, use.
It is flexible that hydraulic continuously variable transmission has layout; The stepless speed regulation wide ranges; Starting, speed governing and commutate soft, rapid, impact little; The dynamic response excellence is operated advantages such as comfortable, has been widely used in fields such as engineering machinery, agriculture and forestry machinery, environmental protection machinery, mining machinery, is a kind of rising speed change gear.But the hydraulic continuously variable transmission of prior art exists that volume is big, complex structure, efficient is lower, assembly is relatively more accurate, the more high deficiency of cost, has limited the occasion of its application, especially is not suitable for the vehicle that travels for long stable distance.
The model utility content
Main purpose of the present utility model at first is to solve existing valve, pump-control-motor speed control system, the problem of the contradiction between efficient and the dynamic characteristic, and next is to improve the reliability of system and reduce cost, and carries
For a kind of pulsewidth modulation hydraulic continuously variable transmission.
The technical solution of the utility model, the pulsewidth modulation hydraulic continuously variable transmission, comprise hydraulic pipe line, it is characterized in that: hydraulic pipe line is provided with metering pump, high-speed switch valve, one-way valve, oil hydraulic motor and accumulator, high-speed switch valve is connected in parallel on the two ends of metering pump, the one-way valve of connecting again, the one-way valve back arranges accumulator, and oil hydraulic motor is arranged between one-way valve and the accumulator.
Further feature is: also comprise the cone valve of being with damping hole, cone valve is connected with high-speed switch valve, and by the open degree of Speed On-off Valve cone valve, cone valve is connected with fuel tank, and the fluid after the off-load is fed in the fuel tank.
In this hydraulic circuit system, speed Control mainly produces the PWM pulse-width signal by controller, drives the high-speed switch valve start, controls opening and closure of high-speed switch valve according to the frequency of pwm signal, the dutycycle of high-low level.Because high-speed switch valve metering pump in parallel two ends, when high-speed switch valve was opened, metering pump was communicated with into and out of the hydraulic fluid port short circuit, and the flux and flow direction high-speed switch valve is in unloading condition; When high-speed switch valve was closed, the metering pump flow directly flowed to oil hydraulic motor by one-way valve.And the effect of one-way valve is when high-speed switch valve is in open mode, and the off-load of pump unit causes the off-load of motor oil pocket, and flow refluxes.Therefore, controller PWM pulse-width signal control high-speed switch valve directly causes the size of pump unit controls flow.Just because of flow is fuel-displaced with pulse mode, come the pressure pulsation of absorption liquid press pump so increase accumulator, improve the stationarity of oil hydraulic motor motion.Whole system adopts the pulse flow fuel system, and when the high-speed switch valve frequency of okperation was very high, induced pressure generally the unstable oscillation situation can not occur.Because high-speed switch valve all is operated in the state of standard-sized sheet or complete shut-down, so power loss is little, has improved the working efficiency of hydraulic system.System's hydraulic motor speed control can be passed through the external velocity transducer of output terminal, forms closed loop control system, the control accuracy height.
With respect to prior art, the utlity model has following advantage:
1, compare with the pump-control-motor stepless speed variator system: system has the fast characteristics of valve controlled velocity modulation system dynamic response, and lower-speed state is more stable, and is simple in structure, with low cost.
2, reaching stepless speed variator system with the valve horse-controlling compares: system effectiveness is improved significantly; The motor filler opening increases one-way valve, reduces in the moderating process influence to the motor chamber pressure, and when having perturbation load, reduces the surge that voltage rise in the motor cavity causes bypass flow, causes hydraulic shock; Accumulator improves system stiffness.Spill losses power is little, and system's temperature rise is little, and is simple in structure, with low cost.
3, system adopts the same servovalve of high-speed switch valve, Proportional valve to compare, have cheap, fast-response good, contamination resistance is strong, be easy to realize advantages such as digital control.
4, whole hydraulic system structure is compacter, and low production cost, is easy to realize integrated at stable working, manoeuvrable, is a kind of rising hydraulic speed regulating device.
Description of drawings
Fig. 1 is the utility model pulsewidth modulation hydraulic continuously variable transmission schematic representation;
Fig. 2 is second kind of structural representation of the utility model pulsewidth modulation hydraulic continuously variable transmission;
Fig. 3 is the utility model Speed On-off Valve cone valve schematic diagram.
Among the figure, 1-hydraulic pressure metering pump, 2-high-speed switch valve, 3-one-way valve, 4-oil hydraulic motor,
5-accumulator, 6-cone valve.
Embodiment
The utility model is described in further detail below in conjunction with the drawings and specific embodiments.
As shown in Figure 1: the utility model pulsewidth modulation hydraulic continuously variable transmission, mainly comprise hydraulic pipe line 10, hydraulic pipe line 10 is provided with metering pump 1, high-speed switch valve 2, one-way valve 3, oil hydraulic motor 4 and accumulator 5, high-speed switch valve 2 is connected in parallel on the two ends of metering pump 1, the one-way valve 3 of connecting again, one-way valve 3 back arrange accumulator 5, and oil hydraulic motor 4 is arranged between one-way valve 3 and the accumulator 5, consist of a pump unit that is output as pulse flow.Pulse flow is regulated according to the pulse frequency of high-speed switch valve, so oil hydraulic motor can carry out stepless change by the tunable pump unit.Accumulator 5 is hydraulic damper or bladder accumulator, and the energy of savings hydraulic oil as prior art, does not describe in detail at this.
Working principle: high-speed switch valve 2 controlled devices send the control of PWM pulse-width signal, are in and close or open mode; When high-speed switch valve 2 is in when closing, the input shaft of metering pump 1 starts driving source, and metering pump 1 flow directly flows to oil hydraulic motor 4 by one-way valve 3, and this moment, oil hydraulic motor 4 can be in quick speedup of short time to maximum (top) speed.When the needs reduction of speed, send PWM pulse-width signal control high-speed switch valve 2 by controller, make high-speed switch valve 2 by certain frequency, reasonably distribute dutycycle to make opening and closure that valve body do not stop, change diverter branch switching time scale.When high-speed switch valve 2 is in open mode (during path), the flow of metering pump 1 mainly is back to the metering pump oil absorbing end by high-speed switch valve 2, one-way valve 3 plays and prevents that flow in oil hydraulic motor 4 chambeies from flowing backward to the effect of high-speed switch valve 2, and this moment, oil hydraulic motor 4 was rotated further by the of short duration repairing of inertia and accumulator 5; Open with closed inversion frequency higherly, high-speed switch valve 2 is closed rapidly afterwards.The flow of metering pump 1 continues by one-way valve 3 to oil hydraulic motor 4 fuel feeding.Therefore, when high-speed switch valve 2 was in open mode, the flow of metering pump 1 failed all to flow to oil hydraulic motor 4, and part has flowed to high-speed switch valve 2 until oil revolving end, just can change the size of supplying with oil hydraulic motor 4 flows, realized speed governing; Namely the flow that flows through by control high-speed switch valve 2 is controlled the flow that one-way valve 3 oil outlets are supplied with oil hydraulic motor 4, the rotating speed of regulator solution pressure motor 4 indirectly.The PWM frequency high level dutycycle that controller sends is more, and the time that high-speed switch valve 2 is opened is more many, and oil hydraulic motor 4 rotating speeds are just more slow; PWM frequency high level dutycycle still less, the time of high-speed switch valve 2 closures is more many, oil hydraulic motor 4 rotating speeds are just more fast.Whole system fuel feeding form is pulsed from dynamically seeing, thus accumulator 5 to also have an effect be exactly to absorb pumping source pressure pulsation.
But native system output shaft installation rate sensor is formed a closed loop speed control system in conjunction with controller, needing to be used for output than the occasion of precise speed.
Fig. 2 is the principle based on the hydraulic stepless speed changes of Fig. 1 pulsewidth modulation, designed with the high-speed switch valve is that pilot valve control cone valve is realized big flow, highi degree of accuracy, the synchronous closed loop control system of high response, in hydraulic pipe line 10, increased cone valve 6, cone valve 6 is connected with high-speed switch valve 2, open degree by high-speed switch valve 2 control cone valves 6, cone valve 6 is connected with fuel tank, and the fluid after the off-load is fed in the fuel tank.High-speed switch valve 2 for the working principle of pilot valve control cone valve 6 as shown in Figure 3, cone valve 6 is logic cone valves of interior band damping hole, high-speed switch valve 2 is pulse-width modulation type high-speed switch valves, send PWM pulse-width signal control high-speed switch valve 2 by controller, when high-speed switch valve 2 in the drawings during state, cone valve 6 control chamber P1 equate with oil suction chamber pressure P 2, and the fluid by cone valve damping hole and high-speed switch valve is zero, the sealing of control chamber fluid is not flowed, and this moment, cone valve cut out; When high-speed switch valve 2 outage, high-speed switch valve 2 is in open mode, and the control oil pocket flows back to fuel tank by high-speed switch valve, because control oil pocket pressure P 1 descends by damping hole, poppet valve core is opened.Because high-speed switch valve 2 is to adopt PWM control, by regulating the size of modulation rate D (being dutycycle), can change the flow by high-speed switch valve 2, and then obtain different control chamber pressure, thereby realize the adjusting by the cone valve flow.
Using high-speed switch valve to control cone valve as pilot valve among Fig. 2, is big flow buncher, realizes big flow, highi degree of accuracy, the synchronous closed loop control of high response, and speed adjustable range is wideer.Widened the application area of pulsewidth modulation hydraulic continuously variable transmission.Pulsewidth modulation hydraulic continuously variable transmission of the present utility model, mainly comprise hydraulic pipe line 10, hydraulic pipe line 10 is provided with metering pump 1, high-speed switch valve 2, one-way valve 3, oil hydraulic motor 4, accumulator 5 and cone valve 6, high-speed switch valve 2 is connected in parallel on the two ends of metering pump 1, the one-way valve 3 of connecting again, one-way valve 3 back arrange accumulator 5, oil hydraulic motor 4 is arranged between one-way valve 3 and the accumulator 5, cone valve 6 is connected with high-speed switch valve 2, by the open degree of high-speed switch valve 2 control cone valves 6, consist of a pump unit that is output as pulse flow.
Claims (2)
1. pulsewidth modulation hydraulic continuously variable transmission, comprise hydraulic pipe line (10), it is characterized in that: hydraulic pipe line (10) is provided with metering pump (1), high-speed switch valve (2), one-way valve (3), oil hydraulic motor (4) and accumulator (5), high-speed switch valve (2) is connected in parallel on the two ends of metering pump (1), the one-way valve (3) of connecting again, one-way valve (3) back arranges accumulator (5), and oil hydraulic motor (4) is arranged between one-way valve (3) and the accumulator (5).
2. according to the described pulsewidth modulation hydraulic continuously variable transmission of claim 1, it is characterized in that: also comprise the cone valve (6) of being with damping hole, cone valve (6) is connected with high-speed switch valve (2), open degree by high-speed switch valve (2) control cone valve (6), cone valve (6) is connected with fuel tank, and the fluid after the off-load is fed in the fuel tank.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320183416 CN203146744U (en) | 2013-04-12 | 2013-04-12 | Pulse width modulation hydraulic stepless speed regulator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320183416 CN203146744U (en) | 2013-04-12 | 2013-04-12 | Pulse width modulation hydraulic stepless speed regulator |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203146744U true CN203146744U (en) | 2013-08-21 |
Family
ID=48974269
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201320183416 Expired - Fee Related CN203146744U (en) | 2013-04-12 | 2013-04-12 | Pulse width modulation hydraulic stepless speed regulator |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN203146744U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109477571A (en) * | 2016-06-28 | 2019-03-15 | 托马斯马格尼特有限公司 | The method of hydrostatic drive and function driver with closed circuit |
| CN110425276A (en) * | 2019-07-19 | 2019-11-08 | 湘潭大学 | A kind of stepless transmission electrohydraulic control system of high-speed switch valve pilot control |
-
2013
- 2013-04-12 CN CN 201320183416 patent/CN203146744U/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109477571A (en) * | 2016-06-28 | 2019-03-15 | 托马斯马格尼特有限公司 | The method of hydrostatic drive and function driver with closed circuit |
| CN109477571B (en) * | 2016-06-28 | 2020-06-26 | 托马斯马格尼特有限公司 | Hydrostatic drive with closed circuit and method for operating the drive |
| CN110425276A (en) * | 2019-07-19 | 2019-11-08 | 湘潭大学 | A kind of stepless transmission electrohydraulic control system of high-speed switch valve pilot control |
| CN110425276B (en) * | 2019-07-19 | 2020-09-15 | 湘潭大学 | High-speed switch valve pilot control's buncher electricity liquid control system |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20130821 Termination date: 20140412 |