CN213981485U - Pressure compensation control type hydraulic pump, rotating speed control system and engineering machinery - Google Patents
Pressure compensation control type hydraulic pump, rotating speed control system and engineering machinery Download PDFInfo
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- CN213981485U CN213981485U CN202022219675.9U CN202022219675U CN213981485U CN 213981485 U CN213981485 U CN 213981485U CN 202022219675 U CN202022219675 U CN 202022219675U CN 213981485 U CN213981485 U CN 213981485U
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Abstract
The utility model relates to an engineering machine tool specifically discloses a pressure compensation control formula hydraulic pump, including electric proportional pressure compensator, the hydraulic pump, liquid accuse switching-over valve and servo piston, electric proportional pressure compensator can be connected with the controller electricity, the first liquid accuse port of liquid accuse switching-over valve passes through electric proportional pressure compensator and is connected with inside draining oil circuit, and this first liquid accuse port is connected in inside output oil circuit through the liquid accuse oil feed oil circuit that is equipped with first choke valve, the second liquid accuse port and the inside output oil circuit of liquid accuse switching-over valve are connected, this liquid accuse switching-over valve switching-over can be driven to the pressure differential between the oil-out pressure of opening pressure of electric proportional pressure compensator and hydraulic pump, thereby make servo piston's rodless chamber and inside output oil circuit or inside draining oil circuit intercommunication selectively. Furthermore, the utility model also discloses a rotational speed control system and engineering machine tool. The utility model discloses a hydraulic pump can make the output flow of hydraulic pump stabilize on the required value.
Description
Technical Field
The utility model relates to an engineering machine tool specifically, relates to a pressure compensation control formula hydraulic pump. Furthermore, the utility model discloses still relate to a rotational speed control system and engineering machine tool that is used for engineering machine tool's heat-radiating equipment.
Background
In the operation process of the large engineering machinery, a part of pressure energy of a hydraulic system of the large engineering machinery is converted into heat energy, so that the oil temperature of the hydraulic system is increased. In order to maintain the temperature of the hydraulic oil within a reasonable range, the hydraulic oil needs to be radiated by using a radiating device. Large-scale engineering machinery such as excavators and loaders generally adopt an independent heat dissipation control system, that is, an input shaft of a heat dissipation fan is not connected with an output shaft of an engine, but a hydraulic motor is adopted to drive the heat dissipation fan to rotate independently.
Fig. 1 shows a heat dissipation control system of an excavator in the prior art, a cooling pump 1 is connected with an output shaft of an engine 2, hydraulic oil output by the cooling pump 1 enters a fan motor 3 to drive the fan motor 3 to rotate, and then a fan 4 is driven to rotate by the fan motor 3. The temperature sensor 5 detects the temperature of the hydraulic oil and feeds the temperature back to the controller 6, the controller 6 determines the required rotating speed of the fan 4 after corresponding operation and simultaneously outputs a certain current to the electric proportional overflow valve 7, and the pressure of the electric proportional overflow valve 7 is adjusted to control the pressure of an oil inlet of the fan motor 3, so that the rotating speed of the fan is controlled.
However, during the working process of the construction machine, the rotation speed of the engine 2 changes along with the change of the load, the rotation speed of the cooling pump 1 changes due to the change of the rotation speed of the engine 2, so that the output flow rate of the cooling pump 1 also changes, and the rotation speed of the fan motor 3 fluctuates due to the fluctuation of the output flow rate of the cooling pump 1, so that the rotation speed of the fan 4 fluctuates, and the rotation speed of the fan 4 cannot be stabilized on a required value, which affects the heat dissipation effect of the hydraulic system on one hand, and on the other hand, causes the fan 4 to generate a large noise.
In view of the above, it is desirable to design a pressure compensated controlled hydraulic pump.
SUMMERY OF THE UTILITY MODEL
The utility model discloses the technical problem that the first aspect will be solved provides a pressure compensation control formula hydraulic pump, and this hydraulic pump can make the output flow of hydraulic pump stabilize on the required value.
The utility model discloses the technical problem that the second aspect will be solved provides a rotational speed control system for engineering machine tool's heat-radiating equipment, and this rotational speed control system can make cooling fan's rotational speed stable on the required value.
The utility model discloses the technical problem that the third aspect will be solved provides an engineering machine tool, and this engineering machine tool's hydraulic system's radiating effect is good and heat abstractor's noise is little.
In order to solve the technical problem, the utility model discloses an aspect provides a pressure compensation control formula hydraulic pump, including pressure control device, hydraulic pump body and discharge capacity adjusting device, discharge capacity adjusting device is suitable for the comparison the first pressure value that pressure control device formed with the second pressure value of the oil-out of hydraulic pump to adjust according to the result of comparison the discharge capacity of hydraulic pump body, thereby work as during the rotational speed change of hydraulic pump body, make the flow stability of hydraulic pump body is in the settlement scope.
Preferably, the pressure control device is an electrically proportional pressure compensator.
Preferably, the displacement regulating means includes a pilot operated directional control valve and a servo piston for regulating the displacement of the hydraulic pump body, the oil outlet of the hydraulic pump is connected with an internal output oil path, the oil inlet of the hydraulic pump is connected with an internal input oil path, the first hydraulic control port of the hydraulic control reversing valve is connected with the internal oil drainage oil path through the pressure control device, the rodless cavity of the servo piston is respectively connected with the internal output oil path and the internal oil drainage oil path through the hydraulic control reversing valve, the pressure difference between the pressure control device and the oil outlet pressure of the hydraulic pump acts on the valve core of the hydraulic control reversing valve through the first hydraulic control port and the second hydraulic control port of the hydraulic control reversing valve to drive the hydraulic control reversing valve to reverse, thereby selectively communicating the rodless chamber of the servo piston with the internal output oil passage or the internal drain oil passage.
Specifically, the first hydraulic control port is connected to the internal output oil path through a hydraulic control oil inlet path provided with a first throttle valve, and the second hydraulic control port of the hydraulic control directional valve is connected to the internal output oil path.
Specifically, the hydraulic pump body is a variable displacement plunger pump.
Specifically, the hydraulic control reversing valve is a two-position three-way reversing valve.
Preferably, a second throttle valve is arranged on a connecting oil path between the rodless cavity of the servo piston and the hydraulic control reversing valve.
Specifically, a safety oil path is connected between the rodless cavity of the servo piston and the internal oil drainage oil path, a third throttle valve is arranged on the safety oil path, one end of the safety oil path is connected to a connecting oil path between the rodless cavity of the servo piston and the hydraulic control reversing valve, and a connecting point is located between the first throttle valve and the second throttle valve; and the connecting position of the other end of the safety oil way on the internal oil drainage oil way is positioned behind the connecting position of the oil outlet of the electric proportional pressure compensator.
The utility model discloses the second aspect provides a rotational speed control system for engineering machine's radiator, including being used for detecting the temperature sensor of hydraulic oil temperature, being used for driving any one of fan pivoted fan motor, controller and the first aspect technical scheme pressure compensation control formula hydraulic pump, temperature sensor with the controller electricity is connected, the controller can receive and according to this temperature sensor's signal control the first pressure value that pressure control device formed, fan motor drive the pressure feedback that the fan produced extremely the oil-out of hydraulic pump is in order to form the second pressure value.
The utility model discloses the third aspect provides an engineering machine tool, including radiator and the second aspect technical scheme that is used for the hydraulic oil cooling a rotational speed control system for engineering machine tool's heat-radiating equipment, the fan motor can drive the fan rotates in order to give the radiator cooling.
The utility model discloses pressure compensation control formula hydraulic pump among the basic embodiment, when the rotational speed that provides the power drive device of mechanical energy for the hydraulic pump changes, the discharge capacity of hydraulic pump can be adjusted to the discharge capacity adjusting device for the output flow of hydraulic pump is stable on the required value, and then makes the rotational speed of the executive component that the hydraulic pump driven stabilize at the required value, and executive component's work is more stable.
Further advantages of the invention, as well as the technical effects of preferred embodiments, will be further explained in the following detailed description.
Drawings
Fig. 1 is a hydraulic schematic diagram of a heat dissipation control system of a construction machine in the related art;
fig. 2 is a flowchart of a rotation speed control method for a heat radiation device of a construction machine according to the present invention;
FIG. 3 is a hydraulic schematic diagram of the pressure compensated controlled hydraulic pump of the present invention;
fig. 4 is a hydraulic schematic diagram of a rotation speed control system of a heat dissipation apparatus for construction machinery according to the present invention;
FIG. 5 is a plot of fan speed versus torque;
FIG. 6 is a control graph of the electrical proportional pressure compensator of the present invention;
FIG. 7 is a schematic diagram of a variation curve of fan speed with load in the speed control system of the present invention;
fig. 8 is a control flowchart of a rotational speed control system for a heat radiating apparatus of a construction machine according to the present invention.
Reference numerals
12 hydraulic control change valve of 11 hydraulic pump body
121 first hydraulic control port 122 second hydraulic control port
13 servo piston 14 electric proportional pressure compensator
15 controller 16 first throttle valve
17 second throttle 18 third throttle
21 internal input oil passage 22 internal output oil passage
23 internal oil drainage oil way 24 hydraulic control oil inlet oil way
25 safety oil circuit
31 temperature sensor 32 fan
33 power driving device for fan motor 34
35 oil tank 36 overflow valve
37 main reversing valve
41 first working oil passage 42 second working oil passage
43 main oil inlet passage 44 main oil return passage
A first working oil port and B second working oil port
C Engine speed D Fan speed in Prior Art
E the utility model discloses well fan speed F fan target speed
Detailed Description
The following describes in detail embodiments of the present invention with reference to the accompanying drawings. It is to be understood that the description of the embodiments herein is for purposes of illustration and explanation only and is not intended to limit the invention.
In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "connected" and "disposed" are to be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; the two elements may be connected directly or indirectly through intervening media, or may be connected through one another or in any combination thereof. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.
The terms "first", "second" and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated, and therefore the features defined as "first", "second" and "third" may explicitly or implicitly include one or more of the features described.
Fig. 2 shows a basic flowchart of a method for controlling a rotational speed of a heat dissipation apparatus for a construction machine according to the present invention. Specifically, the method includes the steps that firstly, the oil temperature of hydraulic oil in a hydraulic system where the heat dissipation equipment is located is obtained, a corresponding first pressure value is obtained according to the oil temperature of the hydraulic oil, and a corresponding second pressure value is generated according to load pressure generated by the heat dissipation equipment; comparing the first pressure value with the second pressure value; and adjusting the displacement of a hydraulic pump in the hydraulic system for driving the heat dissipation equipment according to the comparison result so as to stabilize the flow rate of the hydraulic pump within a flow rate setting range when the rotating speed of the hydraulic pump changes, thereby stabilizing the rotating speed of the heat dissipation equipment within the rotating speed setting range. Since the displacement of the hydraulic pump multiplied by the rotating speed of the hydraulic pump is equal to the flow of the hydraulic pump multiplied by the time, when the rotating speed of the hydraulic pump changes, the control method can adjust the displacement of the hydraulic pump in real time, so that the output flow of the hydraulic pump is basically stabilized on a required value, further, the rotating speed of an actuating element driven by the hydraulic pump is stabilized on the required value, and the working of the actuating element is more stable.
Preferably, the displacement control mechanism of the hydraulic system includes an electric proportional pressure compensator, obtains a corresponding current value according to the oil temperature of the hydraulic oil, and inputs the current value into the electric proportional pressure compensator, so as to control the opening pressure of the electric proportional pressure compensator, wherein the opening pressure is a first pressure value.
Specifically, the pressure comparison module of the hydraulic system comprises a servo piston 13 for controlling the displacement and a hydraulic control reversing valve 12 for controlling the extension and retraction of the servo piston 13, and a first pressure value and a second pressure value respectively act on hydraulic control ports at two ends of the hydraulic control reversing valve 12; the spool of the pilot operated directional control valve 12 can move toward the smaller one of the first pressure value and the second pressure value, so that the magnitude of the first pressure value and the magnitude of the second pressure value are compared. When the rotating speed of the hydraulic pump is reduced, the first pressure value is larger than the second pressure value, the displacement of the hydraulic pump is controlled to be increased, and when the rotating speed of the hydraulic pump is increased, the first pressure value is smaller than the second pressure value, and the displacement of the hydraulic pump is controlled to be reduced.
The utility model relates to a pressure compensation control formula hydraulic pump of embodiment, refer to fig. 3, including electric proportional pressure compensator 14, hydraulic pump body 11, hydraulic control switching-over valve 12 and the servo piston 13 that is used for adjusting 11 discharge capacities of hydraulic pump body. The electrically proportional pressure compensator 14 is electrically connected to the controller 15 to adjust the opening pressure of the electrically proportional pressure compensator 14 via the controller 15. referring to fig. 6, it is common to use an inverse proportional control scheme for the electrically proportional pressure compensator 14 to increase the current to decrease the opening pressure. The oil outlet of the hydraulic pump is connected with an internal output oil path 22, the oil inlet is connected with an internal input oil path 21, the power driving device 34 is connected with the hydraulic pump body 11 to provide power for the hydraulic pump body 11, therefore, the rotating speed change of the power driving device 34 can enable the rotating speed change of the hydraulic pump body 11, the output flow of the hydraulic pump body 11 is further influenced, the hydraulic pump body 11 can drive an actuating element connected with the hydraulic pump body through a hydraulic loop, and the output flow fluctuation of the hydraulic pump body 11 can enable the rotating speed of the actuating element to fluctuate. The first hydraulic control port 121 of the hydraulic control directional control valve 12 is connected with the internal oil drainage oil path 23 through the electric proportional pressure compensator 14, and the first hydraulic control port 121 is connected with the internal output oil path 22 through the hydraulic control oil inlet path 24 provided with the first throttle valve 16, wherein the first throttle valve 16 has the functions of pressure limiting and flow limiting, so that the pressure of the first hydraulic control port 121 of the hydraulic control directional control valve 12 is smaller than the pressure of the second hydraulic control port 122, the second hydraulic control port 122 of the hydraulic control directional control valve 12 is connected with the internal output oil path 22, and the hydraulic control directional control valve 12 is preferably a two-position three-way directional control valve. The rodless cavity of the servo piston 13 is respectively connected to the internal output oil path 22 and the internal oil drainage oil path 23 through the hydraulic control directional valve 12, the pressure difference between the opening pressure of the electric proportional pressure compensator 14 and the oil outlet pressure of the hydraulic pump acts on the valve core of the hydraulic control directional valve 12 through the first hydraulic control port 121 and the second hydraulic control port 122 to drive the hydraulic control directional valve 12 to be reversed, so that the rodless cavity of the servo piston 13 is selectively communicated with the internal output oil path 22 or the internal oil drainage oil path 23, oil is fed into or discharged from the rodless cavity of the servo piston 13, a push rod of the servo piston 13 extends or retracts, and the displacement of the hydraulic pump body 11 is adjusted by adjusting the inclination angle of the swash plate of the hydraulic pump 11.
The following is the operation principle of the pressure compensation control type hydraulic pump according to the above embodiment of the present invention.
When the rotation speed of the power driving device 34 is increased and the rotation speed of the hydraulic pump body 11 is increased, referring to fig. 5, the rotation speed of the actuator is increased so that the torque of the actuator is increased, the load pressure generated by the actuator is fed back to the oil outlet of the hydraulic pump, so that the pressure of the second hydraulic control port 122 is greater than that of the first hydraulic control port 121, the electric proportional pressure compensator 14 reaches the opening pressure, the hydraulic oil of the internal output oil path 22 enters the valve cavity from the second hydraulic control port 122 of the hydraulic control directional control valve 12, the hydraulic oil flows out from the first hydraulic control port 121 and flows to the internal oil drainage oil path 23 through the electric proportional pressure compensator 14, the valve core moves and enables the rodless cavity of the servo piston 13 to be communicated with the internal output oil path 22, oil is fed into the rodless cavity, and the displacement of the hydraulic pump body 11 is reduced; as the displacement of the hydraulic pump body 11 is gradually reduced, the output flow of the hydraulic pump body 11 is reduced, so that the load pressure of the actuator fed back to the oil outlet of the hydraulic pump is reduced, at this time, the pressure of the second hydraulic control port 122 is smaller than that of the first hydraulic control port 121, the electric proportional pressure compensator 14 is closed because the opening pressure is not reached, the hydraulic oil of the hydraulic control oil inlet passage 24 enters the valve cavity from the first hydraulic control port 121, the hydraulic oil is discharged from the second hydraulic control port 122, the valve spool moves, the rodless cavity of the servo piston 13 is communicated with the internal oil discharge passage 23, oil is discharged from the rodless cavity, the displacement of the hydraulic pump body 11 is increased, and thus, the opening pressure of the electric proportional pressure compensator 14 and the oil outlet pressure of the hydraulic pump are always in dynamic balance, so that the output flow of the hydraulic pump body 11 is basically in a required value. If the output flow rate of the hydraulic pump body 11 needs to be increased or decreased, the opening pressure of the electric proportional pressure compensator 14 may be increased or decreased.
In this way, when the rotation speed of the power drive device 34 changes, the servo piston 13 can adjust the displacement of the hydraulic pump body 11, so that the output flow of the hydraulic pump body 11 is basically stabilized at the required value, and further, the rotation speed of the actuator driven by the hydraulic pump is stabilized at the required value, and the operation of the actuator is more stable; moreover, the opening pressure of the electric proportional pressure compensator 14 is controlled by the controller 15, so that the required value of the output flow of the hydraulic pump body 11 can be conveniently adjusted; the spool of the hydraulic control directional valve 12 continuously moves in a small range under the action of the opening pressure of the electric proportional pressure compensator 14 and the oil outlet pressure of the hydraulic pump, and the relative position of the spool in the valve body is adjusted, so that the rodless cavity of the servo piston 13 is used for oil inlet or oil outlet, and the output flow of the hydraulic pump body 11 is accurately and sensitively adjusted.
Specifically, the hydraulic pump body 11 is a variable displacement plunger pump, and the displacement of the variable displacement plunger pump is more conveniently adjusted. The push rod of the servo piston 13 can conveniently adjust the displacement of the hydraulic pump body 11 by adjusting the inclination angle of the swash plate of the variable displacement plunger pump.
Preferably, a second throttle valve 17 is provided on a connecting oil path between the rodless chamber of the servo piston 13 and the pilot operated directional control valve 12. The speed of the oil inlet and the oil drainage of the rodless cavity of the servo piston 13 can be adjusted through the second throttling valve 17, when the flow of the second throttling valve 17 is large, the reaction speed of the pressure compensation control type hydraulic pump is high, and the disturbance of hydraulic oil in the system and the impact on a pipeline are large.
Preferably, a safety oil path 25 is connected between the rodless cavity of the servo piston 13 and the internal oil drainage oil path 23, a third throttle valve 18 is arranged on the safety oil path 25, one end of the safety oil path 25 is connected to a connecting oil path between the rodless cavity of the servo piston 13 and the hydraulic control reversing valve 12, and the connecting point is positioned between the first throttle valve 16 and the second throttle valve 17; and the other end of the relief oil passage 25 is located after the connection position of the oil outlet of the electric proportional pressure compensator 14 at the connection position on the internal drain oil passage 23. The spool of the pilot operated directional control valve 12 constantly moves slightly in the valve cavity, and when the spool is at a certain position, the pilot operated directional control valve 12 is closed, so that the rodless cavity of the servo piston 13 forms a dead cavity, that is, an oil path between the rodless cavity and the pilot operated directional control valve 12 forms a rigid oil path. It should be noted that the first, second and third throttle valves may be replaced by damper holes.
Referring to fig. 4, based on the above technical solution of the pressure compensation controlled hydraulic pump of the present invention, the present invention provides a rotational speed control system for a heat dissipation device of an engineering machine, including a temperature sensor 31 for detecting the temperature of hydraulic oil, a fan motor 33 for driving a fan 32 to rotate, and a pressure compensation controlled hydraulic pump, wherein a hydraulic pump body 11 is connected to a power driving device 34, the power driving device 34 can be a driving device such as an engine or a motor, an internal input oil path 21 and an internal oil drainage oil path 23 are both connected to an oil tank 35, a first working oil port a and a second working oil port B of the fan motor 33 are respectively connected to a first working oil path 41 and a second working oil path 42, the first working oil path 41 and the second working oil path 42 are connected to a main oil inlet path 43 and a main oil drainage oil path 44 via a main directional control valve 37 to switch the forward rotation or reverse rotation of the fan motor 33, the controller 15 is electrically connected to the temperature sensor 31 to be able to receive and control the opening pressure of the electric proportional pressure compensator 14 according to a signal of the temperature sensor 31, thereby controlling the displacement of the hydraulic pump body 11 to adjust the rotation speed of the fan 32.
The following is the operation principle of the rotation speed control system for the heat radiating apparatus of the construction machine according to the basic embodiment of the present invention.
Referring to fig. 3 and 7, when the pressure compensation control type hydraulic pump of the present invention is applied to a rotational speed control system of a heat dissipation apparatus, hydraulic pump drives hydraulic oil to enter a main oil inlet path 43 and a second working oil path 42 in sequence, and then flows back to the oil tank 35 through a first working oil path 41 and a main oil return path 44, so as to form a circulating oil path to drive the fan motor 33 to rotate forward, and the fan motor 33 can drive the fan 32 to rotate forward when rotating forward, thereby dissipating heat from the heat dissipation apparatus; after the main reversing valve 37 reverses, the hydraulic pump 11 drives the hydraulic oil to enter the main oil inlet path 43 and the first working oil path 41 in sequence, and then flows back to the oil tank 35 through the second working oil path 42 and the main oil return path 44, so as to form a circulating oil path to drive the fan motor 33 to rotate reversely, and when the fan motor 33 rotates reversely, the fan 32 can be driven to rotate reversely, so that dust on the radiator can be blown off. When the rotating speed of the engine is increased and the rotating speed of the hydraulic pump 11 is increased, the load pressure generated by the fan motor 33 is increased and fed back to the oil outlet of the hydraulic pump 11, the opening pressure of the electric proportional pressure compensator 14 is smaller than the oil outlet pressure of the hydraulic pump, and the displacement of the pressure compensation control type hydraulic pump is reduced in a self-adaptive mode; the displacement of the hydraulic pump body 11 is gradually reduced, and then the output flow of the hydraulic pump body 11 is reduced, so that the load pressure fed back to the oil outlet of the hydraulic pump by the fan motor 33 is reduced, the opening pressure of the electric proportional pressure compensator 14 is greater than the oil outlet pressure of the hydraulic pump, and the displacement of the pressure compensation control type hydraulic pump is self-adaptively increased. The temperature sensor sends the detected oil temperature to the controller 15, and the controller 15 outputs corresponding current after calculation, and controls the opening pressure of the electric proportional pressure compensator 14 to increase or decrease the output flow of the hydraulic pump.
So, refer to fig. 7, wherein C is engine speed, and D is fan speed among the prior art, and E does the utility model discloses well fan speed, F are fan target speed, and when the rotational speed of engine changes, the discharge capacity of pressure compensation control formula hydraulic pump can corresponding change for the output flow of hydraulic pump body 11 is basically stable on the required value, and then makes the rotational speed of fan motor 33 basically stable on the required value, the utility model discloses well fan speed E laminates fan target speed F more, can play better radiating effect and can avoid or effectively reduce because of fan 32 rotational speed fluctuation noise generation.
Preferably, the oil tank 35 is a closed oil tank in order to keep impurities mixed into the hydraulic oil and keep the hydraulic oil clean.
Preferably, a probe of the temperature sensor 31 is provided at the bottom of the oil tank 35 to obtain the real-time oil temperature of the hydraulic oil. Of course, the probe of the temperature sensor 31 may be designed at other positions according to design requirements.
In order to control the pressure of the main oil inlet path 43 and to cause excess flow to spill back to the tank 35, a spill valve 36 is provided between the main oil inlet path 43 and the main oil return path 44.
Preferably, the main directional control valve 37 is an electromagnetic directional control valve, the electromagnetic directional control valve is electrically connected to the controller 15, and the controller 15 can control the main directional control valve 37 to change the direction to switch the fan motor 33 to rotate forward or reverse.
The check valve is connected in parallel to both ends of the fan motor 33, and the check valve can supply oil to the second working fluid port B of the fan motor 33 when the fan motor 33 rotates reversely. When the fan motor 33 is normally rotated in the forward direction and is switched to the reverse direction, the disturbance of the hydraulic oil in the system is large, and the pressure of the second working oil port B of the fan motor 33 is prevented from being too large.
The utility model discloses an engineering machine tool, including the rotational speed control system who is used for the radiating equipment of engineering machine tool of the radiator that is used for the hydraulic oil cooling and any one of above-mentioned technical scheme, fan motor 33 can drive fan 32 and rotate in order to cool down for the radiator. The utility model discloses an engineering machine tool has adopted the whole technical scheme of above-mentioned all embodiments, consequently has all beneficial effects that the technical scheme of above-mentioned embodiment brought at least.
The preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited thereto. The technical idea of the utility model within the scope, can be right the utility model discloses a technical scheme carries out multiple simple variant, makes up with any suitable mode including each concrete technical feature. In order to avoid unnecessary repetition, the present invention does not separately describe various possible combinations. These simple variations and combinations should also be considered as disclosed in the present invention, all falling within the scope of protection of the present invention.
Claims (10)
1. A pressure compensation control type hydraulic pump is characterized by comprising a pressure control device, a hydraulic pump body (11) and a displacement adjusting device, wherein the displacement adjusting device is suitable for comparing a first pressure value formed by the pressure control device with a second pressure value of an oil outlet of the hydraulic pump and adjusting the displacement of the hydraulic pump body (11) according to the comparison result, so that the flow of the hydraulic pump body (11) is stabilized in a set range when the rotating speed of the hydraulic pump body (11) is changed.
2. A pressure compensated controlled hydraulic pump according to claim 1, characterized in that the pressure control device is an electrically proportional pressure compensator (14).
3. The pressure compensation control type hydraulic pump according to claim 2, wherein the displacement adjusting device comprises a pilot operated directional control valve (12) and a servo piston (13) for adjusting the displacement of the hydraulic pump body (11), an internal output oil path (22) is connected to an oil outlet of the hydraulic pump, an internal input oil path (21) is connected to an oil inlet of the hydraulic pump, a first pilot operated port (121) of the pilot operated directional control valve (12) is connected to an internal drain oil path (23) through the pressure controlling device, a rodless cavity of the servo piston (13) is respectively connected to the internal output oil path (22) and the internal drain oil path (23) through the pilot operated directional control valve (12), and a pressure difference between pressures of the oil outlet of the pilot operated directional control valve (12) and the pressure control device acts on a valve of the pilot operated directional control valve (12) through the first pilot operated port (121) and a second pilot operated port (122) of the pilot operated directional control valve (12) The core can drive the hydraulic control reversing valve (12) to reverse, so that the rodless cavity of the servo piston (13) is selectively communicated with the internal output oil path (22) or the internal oil drainage oil path (23).
4. The pressure-compensated control type hydraulic pump according to claim 3, the first pilot-controlled port (121) being connected to the internal output oil passage (22) through a pilot-controlled oil feed passage (24) provided with a first throttle valve (16), and the second pilot-controlled port (122) of the pilot-controlled directional valve (12) being connected to the internal output oil passage (22).
5. The pressure compensated controlled hydraulic pump of claim 1, wherein the hydraulic pump body (11) is a variable displacement plunger pump.
6. A pressure compensated controlled hydraulic pump according to claim 3, characterized in that the pilot operated directional control valve (12) is a two-position three-way directional control valve.
7. A pressure compensated controlled hydraulic pump according to claim 4, characterized in that a second throttle (17) is provided on the connecting oil path between the rodless chamber of the servo piston (13) and the pilot operated directional control valve (12).
8. The pressure compensated controlled hydraulic pump according to claim 7, characterized in that a safety oil path (25) is connected between the rodless chamber of the servo piston (13) and the internal oil drainage path (23), a third throttle valve (18) is provided on the safety oil path (25), one end of the safety oil path (25) is connected to the connection oil path between the rodless chamber of the servo piston (13) and the pilot operated directional control valve (12), and a connection point is located between the first throttle valve (16) and the second throttle valve (17); and the connection position of the other end of the safety oil path (25) on the internal oil drainage oil path (23) is positioned behind the connection position of the oil outlet of the electric proportional pressure compensator (14).
9. A rotation speed control system for a heat sink of a construction machine, comprising a temperature sensor (31) for detecting the temperature of hydraulic oil, a fan motor (33) for driving a fan (32) to rotate, a controller (15) and the pressure compensation control type hydraulic pump as claimed in any one of claims 1 to 8, wherein the temperature sensor (31) is electrically connected with the controller (15), the controller (15) can receive and control a first pressure value formed by a pressure control device according to a signal of the temperature sensor (31), and the fan motor (33) drives the pressure generated by the fan (32) to feed back to an oil outlet of the hydraulic pump to form a second pressure value.
10. A working machine, characterized by comprising a radiator for cooling hydraulic oil and a rotational speed control system of a heat radiating apparatus for a working machine as claimed in claim 9, said fan motor (33) being capable of driving said fan (32) to rotate to cool said radiator.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202022219675.9U CN213981485U (en) | 2020-09-30 | 2020-09-30 | Pressure compensation control type hydraulic pump, rotating speed control system and engineering machinery |
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| CN202022219675.9U CN213981485U (en) | 2020-09-30 | 2020-09-30 | Pressure compensation control type hydraulic pump, rotating speed control system and engineering machinery |
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| CN213981485U true CN213981485U (en) | 2021-08-17 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022068661A1 (en) * | 2020-09-30 | 2022-04-07 | 中联重科股份有限公司 | Pressure-compensation hydraulic pump, rotation speed control system and control method, and engineering machinery |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022068661A1 (en) * | 2020-09-30 | 2022-04-07 | 中联重科股份有限公司 | Pressure-compensation hydraulic pump, rotation speed control system and control method, and engineering machinery |
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