Novel heat dissipation speed regulation circuit for electric excavator

Abstract

The utility model discloses a novel heat radiation speed regulation circuit for an electric excavator. The novel heat radiation speed regulation circuit comprises a heat radiator, at least two heat radiation fans, a PLC (Programmable Logic Controller) and a temperature sensor, the radiator comprises a heat exchange tube, the temperature sensor is arranged on the outer wall of an inlet of the heat exchange tube, and the temperature sensor is connected with the PLC; the cooling fans face the radiator, and each cooling fan is connected with an external power supply through a relay; the relay is an electromagnetic relay, a starting coil is arranged in the relay, and a terminal of the starting coil is connected with the PLC; and the cooling fan is a three-wire PWM (Pulse Width Modulation) axial flow fan and is provided with a speed regulation terminal, and the speed regulation terminal is connected with the PLC. The hydraulic oil heat dissipation device is installed on an existing electric excavator, the hydraulic oil heat dissipation efficiency of the existing electric excavator is improved, and the working efficiency of the electric excavator is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to engineering machinery technical field, concretely is a novel heat dissipation speed regulation circuit for electric excavator. BACKGROUND

[0002] The hydraulic oil of hydraulic excavator needs heat dissipation when working, so that the hydraulic parts of the excavator can work in a reasonable temperature range.

[0003] Generally speaking, the fuel excavator uses the cooling fan of the engine to heat the hydraulic oil radiator; the electric excavator cannot adopt such heat dissipation mode because of no fuel engine.

[0004] For the electric excavator, a novel hydraulic oil heat dissipation speed regulation circuit is needed, so that they have good hydraulic oil heat dissipation capacity and improve their work efficiency. UTILITY MODEL CONTENTS

[0005] In view of the above high efficient heat dissipation demand of the electric excavator, the utility model aims at providing a novel heat dissipation speed regulation circuit for electric excavator.

[0006] In order to achieve the above purpose, the utility model adopts the following technical scheme:

[0007] A novel heat dissipation speed regulation circuit for electric excavator, including radiator, at least two heat dissipation fan, PLC programmable controller, temperature sensor, the radiator includes heat exchange pipe, the temperature sensor is arranged in the import outer wall of heat exchange pipe, the temperature sensor is connected with PLC programmable controller, the heat dissipation fan is towards radiator, and each heat dissipation fan is connected with external power supply through relay, the relay is electromagnetic relay, and the inside is provided with start coil, and the terminal of start coil is connected with PLC programmable controller, the heat dissipation fan is three line PWM axial flow fan, and is provided with speed regulation terminal, and the speed regulation terminal is connected with PLC programmable controller, the radiator, fan is fixedly arranged on electric excavator, the import of heat exchange pipe is connected with the oil outlet pipe of hydraulic cylinder of electric excavator, and the outlet of heat exchange pipe is connected with the oil inlet pipe of hydraulic oil tank of electric excavator, the PLC programmable controller, relay is arranged in the electric control equipment box of electric excavator.

[0008] Further, the radiator includes heat exchange pipe and heat dissipation fin, and the heat exchange pipe reciprocates through the U-shaped bend through the heat dissipation fin.

[0009] Further, the relay is internally provided with a start coil and a three-contact switch.

[0010] Specifically, the three-contact switch includes an output contact, a normally closed contact, a normally open contact, and a gate lever.

[0011] Specifically, the gate lever is always connected with the output contact, and the gate lever is connected with the normally closed contact in the initial state, and when the starting coil is powered, the gate lever is moved under the action of magnetic force, and is disconnected with the normally closed contact and connected with the normally open contact;

[0012] Specifically, the normally open contact is connected with an external power supply, the output contact is connected with a cooling fan, and one end of the starting coil is grounded and the other end is connected with a PLC programmable controller.

[0013] Further, the cooling fan is provided with a speed regulating terminal, a positive electrode and a negative electrode.

[0014] Specifically, the speed regulating terminal is connected with the PLC programmable controller.

[0015] Specifically, the positive electrode is connected with the output contact of the relay.

[0016] Specifically, the negative electrode is grounded.

[0017] Further, the PLC programmable controller is provided with a level output terminal, a PWM output terminal and an analog input terminal.

[0018] Specifically, the level output terminal is connected with the starting coil.

[0019] Specifically, the PWM output terminal is connected with the speed regulating terminal of the cooling fan.

[0020] Specifically, the analog input terminal is connected with a temperature sensor.

[0021] Specifically, the cooling fan, the relay, the temperature sensor and the PLC programmable controller are grounded.

[0022] The utility model has the following beneficial effects compared with prior art:

[0023] 1. The utility model is installed on the electric excavator, and solves the problem that the fan of the electric excavator without fuel engine cannot perform efficient heat dissipation of hydraulic oil.

[0024] 2. The heat dissipation speed regulation circuit can automatically adjust the rotating speed of the cooling fan according to the temperature of the hydraulic oil, save power, and has good heat dissipation effect. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 It is a structural diagram of a novel heat dissipation speed regulation circuit for an electric excavator.

[0026] In the figure: 1, radiator; 2, first relay; 3, second relay; 4, PLC programmable controller; 5, temperature sensor; F1, first cooling fan; F2, second cooling fan. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the utility model will be apparently and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all the other embodiments obtained by the ordinary skilled in the art without creative labor fall within the protection scope of the utility model.

[0028] Embodiment 1

[0029] Please refer to Figure 1 The utility model provides a novel heat dissipation speed regulation circuit for electric excavator, including radiator 1, at least two cooling fans, PLC programmable controller 4, temperature sensor 5, the radiator 1 includes heat exchange pipe, temperature sensor 5 sets up in the import outer wall of heat exchange pipe, temperature sensor 5 is connected with PLC programmable controller 4, the cooling fan is towards radiator 1, and the power line of each cooling fan is connected with external power supply through relay, the relay is electromagnetic relay, and the inside is provided with start coil, the terminal of start coil is connected with PLC programmable controller 4, the cooling fan is three line PWM axial flow fan, is provided with speed regulation terminal, and speed regulation terminal is connected with PLC programmable controller.

[0030] Among them, the radiator 1 includes heat exchange pipe and radiating fin, the heat exchange pipe reciprocates through U bend and passes through the radiating fin, the radiating fin increases the heat dissipation area and strengthens the heat dissipation effect.

[0031] Among them, the cooling fan is provided with at least two, and the redundancy is increased, when one cooling fan fails, the other cooling fan enhances the wind force under the control of PLC programmable controller, delays the temperature rising speed of cooling liquid, makes the driver have more sufficient time to move the excavator to the safe area and maintains, the cooling fan is three line PWM axial flow fan, is provided with speed regulation terminal, positive pole, negative pole, and the negative pole is grounded.

[0032] The relay is an electromagnetic relay, internally equipped with a start-up coil and a three-contact switch. The three-contact switch includes an output contact, a normally closed contact, a normally open contact, and a gate arm. The gate arm is always connected to the output contact. Initially, the gate arm is connected to the normally closed contact. When the start-up coil is energized, the gate arm moves under magnetic force, disconnecting from the normally closed contact and closing from the normally open contact. The normally open contact is connected to an external power supply, and the output contact is connected to the positive terminal of the cooling fan. One end of the start-up coil is grounded, and the other end is connected to the PLC programmable controller 4.

[0033] The PLC programmable controller 4 is equipped with a level output terminal, a PWM output terminal, and an analog input terminal AI. The level output terminal is connected to the start coil, the PWM output terminal is connected to the speed control terminal of the cooling fan, and the analog input terminal AI is connected to the temperature sensor 5. The PLC programmable controller 4 converts the analog signal from the temperature sensor 5 into temperature data, and starts the relay according to the temperature data to make the cooling fan work. Then, the speed of the cooling fan is adjusted through the analog output. The PLC programmable controller 4 is connected to an external power supply, and the cooling fan, relay, temperature sensor 5, and PLC programmable controller 4 share a common ground.

[0034] When installing this circuit on an electric excavator, the radiator 1 and the fan are fixedly installed in the electrical equipment compartment of the electric excavator. After fixing the fan and aligning it with the radiator 1, the inlet of the heat exchange tube is connected to the oil outlet pipe of the hydraulic cylinder of the electric excavator through a threaded joint, and the outlet of the heat exchange tube is connected to the oil inlet pipe of the hydraulic oil tank of the electric excavator through a threaded joint. The PLC programmable controller 4 and the relay are placed in the electrical control equipment compartment of the electric excavator. After connecting the wires according to the implementation method, it can be used. The hot hydraulic oil enters the radiator 1, is cooled, and then discharged into the hydraulic oil tank.

[0035] Example 2:

[0036] Based on Example 1, this example provides two cooling fans, namely a first cooling fan F1 and a second cooling fan F2. Correspondingly, two relays are provided, namely a first relay 2 and a second relay 3.

[0037] The positive terminal of the first cooling fan F1 is connected to the output contact C of the first relay 2, the normally open contact of the first relay 2 is connected to the power supply 1B+, and the start coil of the first relay 2 is connected to the first level output terminal OUT1 of the PLC programmable controller 4.

[0038] The positive terminal of the second cooling fan F2 is connected to the output contact G of the second relay 2, the normally open contact of the second relay 2 is connected to the power supply 2B+, and the start coil of the second relay 3 is connected to the second level output terminal OUT2 of the PLC programmable controller 4.

[0039] The PLC programmable controller 4 is connected with the power supply 3B+, the first PWM output terminal PWM1 of the PLC programmable controller 4 is connected with the speed regulating terminal K of the first cooling fan F1, the second PWM output terminal PWM2 of the PLC programmable controller 4 is connected with the speed regulating terminal L of the second cooling fan F2, and the analog input terminal AI of the PLC programmable controller 4 is connected with the temperature sensor 5.

[0040] The first cooling fan F1, the second cooling fan F2, the first relay 2, the second relay 3, the PLC programmable controller 4 and the temperature sensor 5 are grounded.

[0041] Speed regulating principle:

[0042] When the temperature sensor 5 detects a temperature signal, the PLC programmable controller 4 considers that the machine is about to work, the first level output terminal OUT1 and the second level output terminal OUT2 output high level, the starting coil of the first relay 2 and the second relay 3 is electrified to attract the gate lever, the normally open contact B and H are closed to conduct, the positive electrode of the first cooling fan F1 and the second cooling fan F2 has electricity, and waits for the arrival of the speed regulating signal, and is ready for work;

[0043] When the temperature sensor 5 detects that the hydraulic oil temperature of the radiator 1 is lower than 40℃, the first PWM output terminal PWM1 and the second PWM output terminal PWM2 of the PLC programmable controller 4 output PWM signal with duty ratio of 0, so that the two cooling fans do not rotate, that is, the radiator 1 does not need to be cooled;

[0044] When the temperature sensor detects that the temperature of the hydraulic oil exceeds 40℃, the first PWM output terminal PWM1 and the second PWM output terminal PWM2 of the PLC programmable controller 4 output PWM signal with low duty ratio, so that the two cooling fans can rotate at low speed;

[0045] When the temperature sensor detects that the temperature of the hydraulic oil reaches 85℃, the first PWM output terminal PWM1 and the second PWM output terminal PWM2 of the PLC programmable controller 4 output PWM signal with the highest duty ratio, and the two cooling fans reach the highest speed to achieve the maximum cooling efficiency;

[0046] Between 40℃ and 85℃, the output duty ratio of the first PWM output terminal PWM1 and the second PWM output terminal PWM2 of the PLC programmable controller 4 obtains different rotating speeds of the two cooling fans, which achieves the cooling effect and saves the electric energy;

[0047] When one fan is damaged, the excavator still has cooling capacity, and the excavator can be safely moved to a safe position for repair.

[0048] In the present application, the parts not discussed in detail, the connection mode of each part in the present application all belong to the known technology in the technical field. Direct application can be used, and no further description is needed.

[0049] In the present application, the term "a plurality of" refers to two or more than two, unless otherwise explicitly limited. The terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, "connecting" can be fixed connection, or detachable connection, or integrally connected; "connected" can be directly connected, or indirectly connected through an intermediate medium. For ordinary skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0050] In the description of the present application, it should be understood that the terms "upper", "lower", "left", "right", "front", "back" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or unit referred to must have a particular direction, be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation on the present application.

[0051] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "specific embodiments" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0052] The above is only the preferred embodiment of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various changes and variations. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A novel heat-dissipation speed regulation circuit for an electric excavator, characterized by comprising: The heat sink, at least two heat dissipation fans, a PLC programmable controller and a temperature sensor are included. The heat sink includes heat exchange pipes, and the temperature sensor is arranged on the outer wall of the inlet of the heat exchange pipes. The heat dissipation fans are arranged towards the heat sink, and each heat dissipation fan is connected with an external power supply through a relay. The relay is an electromagnetic relay, and an activation coil is arranged in the relay. The heat dissipation fan is a three-wire PWM axial fan, and a speed regulating terminal is arranged on the heat dissipation fan. The heat sink and the fan are fixedly arranged on an electric excavator, and are used for heat dissipation of hydraulic oil. The inlet of the heat exchange pipes is connected with an oil outlet pipe of a hydraulic cylinder of the electric excavator, and the outlet of the heat exchange pipes is connected with an oil inlet pipe of a hydraulic oil tank of the electric excavator. The PLC programmable controller and the relay are arranged in an electric control equipment box of the electric excavator.

2. A novel heat-dissipation speed regulation circuit for an electric excavator according to claim 1, characterized in that, The heat sink includes heat exchange pipes and heat dissipation fins, and the heat exchange pipes reciprocate through the heat dissipation fins through U-shaped bends.

3. A novel heat-dissipation speed regulation circuit for an electric excavator according to claim 1, characterized in that, The relay is internally provided with an activation coil and a three-contact switch. The three-contact switch includes an output contact, a normally closed contact, a normally open contact and a lever. The lever is always connected with the output contact, and the lever is connected with the normally closed contact in the initial state. When the activation coil is electrified, the lever moves under the magnetic force, is disconnected with the normally closed contact and is connected with the normally open contact.

4. A novel heat-dissipation speed regulation circuit for an electric excavator according to claim 3, wherein The normally open contact is connected with an external power supply, the output contact is connected with the heat dissipation fan, one end of the activation coil is grounded, and the other end is connected with the PLC programmable controller. The heat dissipation fan is provided with a speed regulating terminal, a positive electrode and a negative electrode. The speed regulating terminal is connected with the PLC programmable controller. The positive electrode is connected with the output contact of the relay.

5. A novel heat-dissipation speed regulation circuit for an electrically operated excavator according to claim 4, wherein The negative electrode is grounded. The PLC programmable controller is provided with a level output terminal, a PWM output terminal and an analog input terminal. The level output terminal is connected with the activation coil. The PWM output terminal is connected with the speed regulating terminal of the heat dissipation fan. The analog input terminal is connected with the temperature sensor. The heat dissipation fan, the relay, the temperature sensor and the PLC programmable controller are grounded.

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