阅读说明：本技术 一种具有基础速度的双泵合流自动液压调速系统 (Double-pump confluence automatic hydraulic speed regulation system with basic speed ) 是由 宋永刚 宋扬 于 2018-06-01 设计创作，主要内容包括：本发明公开了一种具有基础速度的双泵合流自动液压调速系统,包括一个由固定转速动力源驱动的定量泵1和一个由变化转速动力源驱动的定量泵2以及输出马达或油缸。所述定量泵1在恒转速驱动下输出恒定流量,构成系统基础流量,定量泵2在随工况变化的动力源驱动下输出与动力源转速成正比的变化流量,双泵合流的压力油源驱动液压马达或油缸,液压马达的转速或油缸速度自动随作业工况变化。通过合理配置定量泵1和定量泵2的排量比可以实现不同基础速度和不同灵敏度的调速特性,定量泵1的输出流量用以保证输出马达的最低转速或油缸的最低往复速度,并可用以实现必要的液压操作。(The invention discloses a double-pump confluence automatic hydraulic speed regulating system with basic speed, which comprises a fixed displacement pump 1 driven by a power source with fixed rotating speed, a fixed displacement pump 2 driven by a power source with variable rotating speed, and an output motor or an oil cylinder. The constant flow pump 1 outputs a constant flow under the drive of a constant rotating speed to form a system basic flow, the constant flow pump 2 outputs a variable flow which is in direct proportion to the rotating speed of a power source under the drive of the power source which changes along with working conditions, the pressure oil source of the double-pump confluence drives a hydraulic motor or an oil cylinder, and the rotating speed or the oil cylinder speed of the hydraulic motor automatically changes along with the working conditions. The speed regulation characteristics of different basic speeds and different sensitivities can be realized by reasonably configuring the displacement ratio of the constant delivery pump 1 and the constant delivery pump 2, the output flow of the constant delivery pump 1 is used for ensuring the lowest rotating speed of an output motor or the lowest reciprocating speed of an oil cylinder, and the necessary hydraulic operation can be realized.)

1. An automatic hydraulic speed regulating system with basic speed and double pump confluence is characterized by comprising a fixed displacement pump 1 driven by a fixed rotating speed power source, a fixed displacement pump 2 driven by a variable rotating speed power source according to working conditions, an output motor or an oil cylinder and other accessories.

2. The dual-pump interflow automatic hydraulic governor system of claim 1, wherein the fixed displacement pump 1 and the fixed displacement pump 2 are driven by different power sources, respectively, the fixed displacement pump 1 being driven by a fixed rotational speed power source, the fixed displacement pump 2 being driven by a variable rotational speed power source depending on the operating conditions.

3. The system according to claim 1, wherein the output flows of the fixed displacement pump 1 and the fixed displacement pump 2 are combined to drive a hydraulic actuator such as a motor or a cylinder to have a proportional speed control characteristic.

4. The system according to claim 1, wherein the speed regulation sensitivity of the system can be changed by configuring the displacement ratio of the fixed displacement pump 1 to the fixed displacement pump 2.

5. The system according to claim 1, wherein the displacement and driving speed configuration of the fixed displacement pump 1 determine the basic flow of the system, i.e. determine the minimum working speed of the actuator.

6. The system of claim 1 and 5, wherein the system is adjustable in speed from above the minimum operating speed to a speed determined by parameters such as the displacement of the fixed displacement pump 2, its maximum driving speed, and the displacement of the system actuator motor or the cylinder diameter.

Technical Field

The invention belongs to the technical field of machinery and special vehicle transmission systems, and particularly relates to a hydraulic drive system requiring follow-up speed regulation.

Background

With the continuous improvement of the industrialization level, the performance requirements of various production operation machines are higher and higher, and the matching precision requirements of operation parameters are higher and higher. Modern industrial systems and special automobiles adopt more and more hydraulic transmission, along with the technical progress, hydraulic systems are more and more complex, execution elements for cooperative operation are more and more, mutual coordination among the execution elements is required, and the execution elements are adaptive to the change of operation working conditions, namely the execution elements of the hydraulic systems can change along with the change of the working conditions. For example, modern sanitation cleaning vehicles generally adopt a hydraulic system to drive a chassis to run, a disc brush to rotate, a box body to lift, a suction nozzle to lift and the like. Researches prove that when the rotating speed of a disc brush of the sweeper and the running speed of the chassis during operation have a reasonable proportional matching relation, garbage particles on the road surface can be thrown to the front of a suction nozzle positioned on the inner side, and reliable suction and high-efficiency sweeping are guaranteed. However, the chassis operation running speed of the sweeper needs to be changed irregularly at any time according to the road surface pollution degree and traffic conditions, and the long-time constant speed operation is difficult, so that the rotation speed of the disc brush is required to be changed along with the chassis speed. At present, chassis running power and operating system power of many double-engine sweeper trucks at home and abroad adopt two sets of completely independent systems without any association, and the follow-up of the rotating speed of a disc brush and the running speed of chassis operation is difficult to realize, namely, the reasonable matching of the rotating speed of the disc brush and the running speed of the chassis in the operation process cannot be ensured.

Similar to the problem that the rotating speed of a disc brush of a sweeper needs to be matched with the running speed of chassis operation, the method is generally known by other mechanical systems adopting hydraulic transmission, and corresponding methods are adopted to realize the adaptation of the output speed of the hydraulic system to the operation working condition and strive for the timeliness and the accuracy of follow-up. According to the known related art, the following two methods are roughly used for the follow-up speed regulation of the disc brush and other hydraulic actuators of the sweeper: firstly, a variable hydraulic pump is used as a pressure oil source to drive a disc brush motor or other executing elements, the angle of a swash plate of the variable pump is controlled by a controller adopting algorithms such as PID (proportion integration differentiation) algorithm, fuzzy control and the like through artificially inputting electric signals or detecting chassis running speed signals, and the output flow is changed, so that the rotating speed of the disc brush motor or the working speed of other executing elements is changed. Secondly, a fixed displacement pump is used as a pressure oil source, stepped speed regulation is realized by a throttling or shunting method, a disc brush or other executing elements are changed in speed, the operation running speed of a chassis of the sweeper or the speed requirements of other systems are roughly met, and the adjustment of the running speed of a sweeping disc motor is realized by adopting a stepped shunting mode as in a hydraulic control system and a control method of the sweeper (CN 201710462130.0). The disadvantages of this approach are the waste of oil sources, the inefficiency of the system and the inability to ensure an accurate match of the pan brush speed to the chassis travel speed. Other hydraulic system patents which adopt double pump confluence are all different from the application purpose and function of the invention. For example, a walking double-pump confluence system (201310197336.7), mainly solves the problems of high cost and energy waste caused by supplying oil to a driving motor by a single pump when a hydraulic system of engineering machinery is in a walking state. A double pump confluence hydraulic control system (201510152107.2) is disclosed for reducing the hydraulic shock of a hydraulic actuator at the end of its stroke.

Therefore, the known prior art has defects in principle, function and performance, and does not completely meet the requirement that the working speed of some mechanical systems adopting hydraulic transmission automatically adapts to the speed requirement determined by the working condition.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a hydraulic system which can automatically ensure that the rotating speed of an output motor or the speed of an oil cylinder is adaptive to the speed requirement determined by the working condition. By utilizing the system principle, aiming at the speed requirement of a specific actuating mechanism containing a hydraulic actuating element, the speed of an output motor or an oil cylinder of the hydraulic system can be automatically adapted to the speed requirement determined by the working condition by reasonably configuring the element parameters and the driving system parameters of the hydraulic system.

In order to achieve the purpose, the invention adopts the technical scheme that: the utility model provides an automatic hydraulic pressure governing system of double pump confluence with basic speed which characterized in that: the system comprises a fixed displacement pump 1 driven by a power source with a fixed rotating speed, a fixed displacement pump 2 driven by the power source related to the working condition, an actuating element of the system, namely a hydraulic motor or a hydraulic oil cylinder, a control valve, accessories and the like.

The automatic hydraulic speed regulating system with the basic speed and the double-pump confluence is characterized in that the fixed displacement pump 1 and the fixed displacement pump 2 are respectively driven by two different power sources instead of being connected in series through a shaft. The rotating speed of the power source of the constant delivery pump 1 is not changed, namely the constant delivery pump with the constant rotating speed, and the driving speed of the power source of the constant delivery pump 2 changes along with the change of the working condition, if the operation running speed of the sweeper is reduced or accelerated, the rotating speed of the constant delivery pump 2 is in direct proportion to the operation running speed.

The automatic hydraulic speed regulating system with the basic speed and the double-pump confluence is characterized in that the constant hydraulic flow output by the constant delivery pump 1 under the drive of the constant rotating speed power source and the hydraulic flow output by the constant delivery pump 2 under the drive of the variable rotating speed power source and changing along with the working condition are converged and superposed to form a total hydraulic oil flow which has a threshold value and changes along with the working condition. The total hydraulic flow changes along with the change of working conditions and has a linear and proportional relation.

The automatic hydraulic speed regulating system with the basic speed and the double-pump confluence is characterized in that the speed regulating characteristic of the system can be configured according to different requirements. The system has different speed regulation sensitivity if the displacement ratio of the fixed displacement pump 1 and the fixed displacement pump 2 is different, if the displacement of the fixed displacement pump 2 is larger, the amplitude of the total flow changing along with the working condition is more obvious, the range of the rotating speed change of the output motor is larger, namely the speed regulation characteristic of the system is more sensitive, and vice versa.

The automatic hydraulic speed regulating system with the double-pump confluence and the basic speed is characterized in that the displacement and the driving rotating speed of the fixed displacement pump 1 determine the basic flow of the system, and the larger the displacement and the higher the driving rotating speed are, the larger the basic flow is, namely the lower rotating speed of the output motor is, or the lower action speed of the oil cylinder is, and vice versa.

Compared with the prior art, the invention has the following advantages:

1. The positive displacement speed regulation is high-efficient energy-conserving.

2. The signal input is fast, and the response output is fast.

3. Automatic speed regulation, reliable work and convenient operation.

The invention is described in further detail below with reference to the figures and to one of the embodiments.

Drawings

FIG. 1 is a schematic diagram of a hydraulic system according to one embodiment of the present invention

FIG. 2 is a graph showing the speed control characteristic according to one embodiment of the present invention

Description of the reference numerals

1-fixed displacement pump 12-fixed displacement pump 23-oil suction filter

4-ventilating cap 5-oil tank oil level indicator 6-oil return filter

7-circulation on-off valve 8-radiator 9-execution oil cylinder

10-control valve group 11-actuating motor

Detailed Description

FIG. 1 is a schematic diagram of a hydraulic system in accordance with one preferred embodiment of the present invention. The system is a double-pump confluence hydraulic automatic speed regulating system with basic speed. The hydraulic system has the advantages that the working speed of the actuating element of the system can be linked according to the driving speed of the constant delivery pump 2 directly related to the working condition, the output speed of the actuating element of the hydraulic system meets the requirement of the working condition, the reasonable matching of the working parameters of the system is ensured, and the performance is optimal.

In order to achieve the purpose, the invention adopts the technical scheme that: the utility model provides an automatic hydraulic pressure governing system of double pump confluence with basic speed which characterized in that: the device comprises a fixed displacement pump 1 driven by a power source with a fixed rotating speed, a fixed displacement pump 2 driven by the power source related to the working condition, and executing elements of the system, namely a hydraulic motor 11 or a hydraulic oil cylinder 9, a control valve 10, an oil suction filter 3, a filter 6, a radiator 8, a circulation on-off valve, an oil tank level indicator 5, a ventilation cap 4 and the like. The system can only have an actuating motor or an actuating cylinder.

The automatic hydraulic speed regulating system with the basic speed and the double-pump confluence is characterized in that the fixed displacement pump 1 and the fixed displacement pump 2 are respectively driven by two different power sources instead of being connected in series through a shaft. The rotating speed of a power source of the constant delivery pump 1 is not changed, namely, the constant delivery pump is in a constant rotating speed, for a common double-engine sweeper at present, the power source of the constant delivery pump 1 is an upper auxiliary engine, the auxiliary engine shares auxiliary engine power with working devices such as a fan, and in order to ensure high-speed and high-efficiency operation of the devices such as the fan, the auxiliary engine is usually configured on a working point, namely, the constant rotating speed operation. The power source of the constant delivery pump 2 is taken from a device directly related to the operation working condition, and the speed of the constant delivery pump 2 changes along with the change of the operation working condition, such as a sweeper operation running driving system, particularly a sweeper adopting a BX series full-power take-off transfer case, the constant delivery pump 2 can be directly butted with an operation running motor, so that the hydraulic flow of the system changes along with the operation speed, and the rotating speed of a disc brush motor is in direct proportion to the operation running speed.

The automatic hydraulic speed regulating system with the basic speed and the double-pump confluence is characterized in that the constant hydraulic flow output by the constant delivery pump 1 under the drive of the constant rotating speed power source and the hydraulic flow output by the constant delivery pump 2 under the drive of the variable rotating speed power source and changing along with the working condition are converged and superposed to form a total hydraulic oil flow which has a threshold value and changes along with the working condition. The total hydraulic flow changes along with the change of working conditions and has a linear and direct proportional relation. For a sweeper, the requirement between the rotating speed of the disc brush and the running speed of the chassis operation is in a proportional relation, and the higher the running speed of the chassis operation is, the higher the rotating speed of the disc brush is required to be.

The automatic hydraulic speed regulating system with the basic speed and the double-pump confluence is characterized in that the speed regulating characteristic of the system can be configured according to different requirements. The system has different speed regulation sensitivity if the displacement ratio of the fixed displacement pump 1 and the fixed displacement pump 2 is different, if the displacement of the fixed displacement pump 2 is larger, the amplitude of the total flow changing along with the working condition is more obvious, the range of the rotating speed change of the output motor is larger, namely the speed regulation characteristic of the system is more sensitive, and vice versa. When the displacement of the metering pump 2 is larger, the total flow is more sensitive to the change of the working condition, namely the driving speed, and the output flow is more variable, so that the change of the rotating speed of the disc brush is larger, as shown by curves 2 and 4 in fig. 2. When the displacement of the metering pump 2 is small, the total flow is insensitive to the change of the working condition, namely the driving speed, and the change of the output flow is not large, so that the change of the rotating speed of the disc brush is small, as shown by curves 1 and 3 in fig. 2.

the automatic hydraulic speed regulating system with the double-pump confluence and the basic speed is characterized in that the displacement and the driving rotating speed of the fixed displacement pump 1 determine the basic flow of the system, and the larger the displacement and the higher the driving rotating speed are, the larger the basic flow is, namely the lower rotating speed of the output motor is, or the lower action speed of the oil cylinder is, and vice versa. When the displacement and the rotational speed of the dosing pump 1 are high, it is decided that the base speed of the system is high, as shown in fig. 2 b. When the displacement and the rotational speed of the dosing pump 1 are low, it is determined that the base speed of the system is low, as shown in fig. 2 a.

In conclusion, the invention not only can make the output speed of the execution element of the hydraulic system follow the change of the working condition, realize stepless continuous speed regulation and ensure the accurate matching of the working parameters of the cooperative operation device, but also has simple system, automatic adaptation, no need of control and no need of operation.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and all simple modifications, changes and equivalent structural changes made to the above embodiment according to the technical spirit of the present invention still fall within the protection scope of the technical solution of the present invention.