Electromagnetic brake auxiliary circuit of forklift controller
By using PWM signal to control the on-voltage of the switch tube and increasing current feedback and short-circuit protection functions in the electromagnetic brake circuit of the forklift controller, the energy loss and lack of protection caused by the constant working voltage of the brake coil are solved, and low power consumption is achieved and safe and stable brake operation.
Patent Information
- Application Number
- CN202420796795.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-17
- Publication Date
- 2024-12-20
- Estimated Expiration
- 2034-04-17
AI Technical Summary
In the electromagnetic brake circuit of the existing forklift controller, the operating voltage of the brake coil is constant, resulting in unnecessary energy loss and lack of brake short circuit protection function.
A forklift controller electromagnetic brake auxiliary circuit is designed, using PWM signal to control the on-voltage of the switch tube, so as to realize the operation of the brake coil in a low-power state, and add current feedback and short-circuit protection functions, through the driving chip and current limiting Circuits and detection circuits to limit current and detect short circuits.
It effectively reduces the loss during brakes, improves energy utilization, ensures the safety and stability of the brakes, and achieves low power consumption and short circuit protection.
Smart Images
Figure CN222204696U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of forklift controllers, and in particular to an electromagnetic brake auxiliary circuit of a forklift controller. Background Art
[0002] In the electromagnetic brake circuit of the previous forklift controller, the working voltage of the brake coil is generally constant. Because the principle of electromagnetic brake is similar to that of relay, when the coil voltage reaches the pull-in voltage, the voltage reduction will not affect the coil operation. Only when the coil voltage drops below the release voltage will the coil stop working. Therefore, if the coil voltage remains constant, the controller will generate unnecessary energy loss, and the circuit structure is relatively simple, without any brake short-circuit protection and other functions. Summary of the invention
[0003] In order to solve the above problems, the present application provides an electromagnetic brake auxiliary circuit of a forklift controller.
[0004] The technical solutions provided by this application are as follows:
[0005] In some embodiments, the present application provides a forklift controller electromagnetic brake auxiliary circuit, comprising:
[0006] A driving circuit, used for receiving a PWM brake signal and outputting a switch control signal;
[0007] A switch tube, connected to the driving circuit and the electromagnetic brake coil of the forklift controller, for receiving the switch control signal and controlling the electromagnetic brake coil of the forklift controller to work;
[0008] The current limiting circuit is connected to the switch tube and is used to make the VGS voltage of the switch tube less than the conduction voltage of the switch tube when the current of the electromagnetic brake coil of the forklift controller exceeds a preset threshold, thereby limiting the current of the electromagnetic brake coil of the forklift controller.
[0009] In some embodiments, the first end of the electromagnetic brake coil of the forklift controller is connected to the bus voltage output end, and is used to receive the bus voltage to work;
[0010] Among them, when it is within the preset time, the input voltage of the electromagnetic brake coil of the forklift controller reaches the pull-in voltage, and when it exceeds the preset time, the input voltage of the electromagnetic brake coil of the forklift controller is maintained above the release voltage, so that the electromagnetic brake coil of the forklift controller continues to work under the preset working voltage state.
[0011] In some embodiments, it further comprises:
[0012] The detection circuit is connected to the second end of the switch tube, the current limiting circuit, and the electromagnetic brake coil of the forklift controller, and is used to detect the voltage of the electromagnetic brake coil of the forklift controller. When the detection circuit detects a short circuit signal, the output of the PWM brake signal is turned off to turn off the switch tube.
[0013] In some implementations, the driving circuit includes: a driving chip and a first resistor;
[0014] The input end of the driving chip is connected to the output end of the PWM brake signal, the output end of the driving chip is connected to the first resistor, and the first resistor is connected to the first end of the switch tube;
[0015] The driving chip receives the PWM brake signal, and conducts the amplified PWM brake signal through the first resistor to turn on the switch tube, so that the electromagnetic brake coil of the forklift controller works normally.
[0016] In some implementations, the driving circuit further includes: a second resistor;
[0017] The first end of the second resistor is connected to the first resistor and the first end of the switch tube; the second end of the second resistor is grounded.
[0018] In some implementations, the detection circuit includes: a single chip microcomputer, a third resistor and a capacitor;
[0019] The single chip microcomputer is connected to the second end of the switch tube and the electromagnetic brake coil of the forklift controller through the third resistor; the single chip microcomputer is connected to the current limiting circuit through the capacitor.
[0020] In some embodiments, the current limiting circuit includes: a fourth resistor;
[0021] A first end of the fourth resistor is connected to the third end of the switch tube, and a second end of the fourth resistor is grounded.
[0022] In some embodiments, it further comprises:
[0023] A diode is connected to a first end and a second end of the electromagnetic brake coil of the forklift controller.
[0024] In some embodiments, the driver chip is a MOS driver chip.
[0025] In some implementations, the switch tube is an NMOS tube.
[0026] Compared with the prior art, the electromagnetic brake auxiliary circuit of a forklift controller provided by the present application has at least the following beneficial effects:
[0027] In view of the loss and protection problems of the brake coil, the utility model has made improvements. PWM is used to control the turn-on voltage of MOS, so that the brake coil can operate in a low power consumption state, and current feedback and short-circuit protection functions are added, which improves energy utilization, reduces losses during braking, and ensures safety and stability during braking. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The preferred implementation scheme will be described below in a clear and understandable manner with reference to the accompanying drawings to further illustrate the above-mentioned characteristics, technical features, advantages and implementation methods of the present application.
[0029] Figure 1 It is a schematic diagram of an electromagnetic brake auxiliary circuit of a forklift controller provided in an embodiment of the present application;
[0030] Figure 2 It is a schematic diagram of a conventional 12VPWM setting circuit provided in an embodiment of the present application;
[0031] Figure 3 It is a schematic diagram of another conventional 12VPWM setting circuit provided in an embodiment of the present application;
[0032] Figure 4 It is a schematic diagram of voltage values provided in an embodiment of the present application. DETAILED DESCRIPTION
[0033] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.
[0034] It should be understood that when used in this specification and the appended claims, the term "comprising" indicates the presence of the described features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or collections.
[0035] In order to simplify the drawings, only the parts related to the application are schematically shown in each figure, and they do not represent the actual structure of the product. In addition, in order to simplify the drawings and facilitate understanding, in some figures, only one or more parts with the same structure or function are schematically drawn or marked. In this article, "one" not only means "only one", but also means "more than one".
[0036] It should be further understood that the term “and / or” used in the specification and appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.
[0037] In this document, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0038] In addition, in the description of the present application, the terms “first”, “second”, etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance or order.
[0039] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the specific implementation methods of the present application will be described below with reference to the accompanying drawings. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings and other implementation methods can be obtained based on these drawings without creative work.
[0040] In one embodiment, the present application provides a forklift controller electromagnetic brake auxiliary circuit, specifically including:
[0041] The driving circuit 100 is used to receive a PWM brake signal and output a switch control signal.
[0042] Among them, the PWM brake signal refers to BRAKE, which is the PWM signal output by the single-chip microcomputer. Brake means brake. At this time, the output switch control signal is an on signal.
[0043] The switch tube 200 is connected to the driving circuit and the electromagnetic brake coil of the forklift controller, and is used to receive the switch control signal and control the electromagnetic brake coil of the forklift controller to work.
[0044] Specifically, when the switch tube 200 receives a switch control signal, which is an on signal, the switch tube 200 will be turned on, and the electromagnetic brake coil of the forklift controller will receive the bus voltage to work.
[0045] The current limiting circuit 300 is connected to the switch tube and is used to make the VGS voltage of the switch tube less than the conduction voltage of the switch tube when the current of the electromagnetic brake coil of the forklift controller exceeds a preset threshold, thereby limiting the current of the electromagnetic brake coil of the forklift controller.
[0046] In response to the loss and protection issues of the brake coil, the utility model uses PWM signal to control the conduction voltage of the switch tube, so that the electromagnetic brake coil of the forklift controller operates in a low power consumption state, and adds current feedback and short-circuit protection functions, thereby improving energy utilization, reducing losses during braking, and ensuring safety and stability during braking.
[0047] Wherein, the first end of the electromagnetic brake coil of the forklift controller is connected to the bus voltage output end, and is used to receive the bus voltage for operation.
[0048] Among them, when it is within the preset time, the input voltage of the electromagnetic brake coil of the forklift controller reaches the pull-in voltage, and when it exceeds the preset time, the input voltage of the electromagnetic brake coil of the forklift controller is maintained above the release voltage, so that the electromagnetic brake coil of the forklift controller continues to work under the preset working voltage state.
[0049] Among them, Figure 2 As shown, the driving circuit includes: a driving chip U1 and a first resistor R1;
[0050] The input end of the driving chip is connected to the output end of the PWM brake signal, the output end of the driving chip is connected to the first resistor, and the first resistor is connected to the first end of the switch tube; wherein, the driving chip receives the PWM brake signal, and passes the amplified PWM brake signal through the first resistor to turn on the switch tube, so that the electromagnetic brake coil of the forklift controller works normally.
[0051] Wherein, the driver chip is a MOS driver chip.
[0052] For example, Figure 4As shown, it is assumed that the rated working voltage of the electromagnetic brake coil of the forklift controller is 24V, the pull-in voltage is 14.4V, and the release voltage is 2.4V. The voltage of the electromagnetic brake coil of the forklift controller needs to reach 14.4V when it starts working, and the voltage to maintain the electromagnetic brake coil of the forklift controller only needs to be above 2.4V. When the forklift is braking, the microcontroller outputs a PWM signal BRAKE. This signal is amplified by the driver chip U1 and then controls the switch tube Q1 to turn on through the first resistor R1. In the initial 1s, the duty cycle of the PWM signal output by the microcontroller is the largest, which can ensure that the electromagnetic brake coil of the forklift controller reaches the pull-in voltage. After 1s, the duty cycle of the PWM signal is reduced to the minimum, and the voltage of the electromagnetic brake coil of the forklift controller is maintained above the release voltage, thereby ensuring that the electromagnetic brake coil of the forklift controller continues to work under the minimum working voltage state.
[0053] In one embodiment, the driving circuit further includes: a second resistor R2;
[0054] The first end of the second resistor is connected to the first resistor and the first end of the switch tube; the second end of the second resistor is grounded.
[0055] In order to prevent the electromagnetic brake coil of the forklift controller from being damaged by a short circuit, a detection circuit is added in this embodiment.
[0056] Exemplarily, a detection circuit is connected to the second end of the switch tube, the current limiting circuit, and the electromagnetic brake coil of the forklift controller, and is used to detect the voltage of the electromagnetic brake coil of the forklift controller. When the detection circuit detects a short circuit signal, the output of the PWM brake signal is turned off to turn off the switch tube.
[0057] Among them, Figure 3 As shown, the detection circuit includes: a single chip microcomputer MCU, a third resistor R3 and a capacitor C1.
[0058] The single chip microcomputer is connected to the second end of the switch tube and the electromagnetic brake coil of the forklift controller through the third resistor; the single chip microcomputer is connected to the current limiting circuit through the capacitor.
[0059] Among them, the VBK signal is used to detect the voltage of the electromagnetic brake coil of the forklift controller. When the electromagnetic brake coil of the forklift controller is short-circuited, the VBK signal is high level. The MCU detects the short-circuit signal and turns off the PWM signal of BRAKE to turn off the switch tube Q1.
[0060] In one embodiment, Figure 3 As shown, the current limiting circuit includes: a fourth resistor R4;
[0061] A first end of the fourth resistor is connected to the third end of the switch tube, and a second end of the fourth resistor is grounded.
[0062] The fourth resistor R4 is used to make the VGS voltage of the switch tube Q1 smaller than the MOS conduction voltage when the current of the electromagnetic brake coil of the forklift controller is too large, thereby limiting the current of the electromagnetic brake coil of the forklift controller.
[0063] In one embodiment, it further includes:
[0064] A diode D1 is connected to a first end and a second end of the electromagnetic brake coil of the forklift controller.
[0065] In one embodiment, the switch tube is an NMOS tube.
[0066] For example, Figure 3 , 4 As shown, the utility model provides an energy-saving, current-limiting and short-circuit protection circuit for electromagnetic brake of a forklift controller.
[0067] U1 is a MOS driver chip, Q1 is an NMOS tube, VBUS is a bus voltage of 24V, BRAKE is a microcontroller PWM signal, VBK is a coil voltage detection signal, and R4 is a current limiting resistor. The rated working voltage of the electromagnetic brake coil is 24V, the pull-in voltage is 14.4V, and the release voltage is 2.4V. The voltage of the electromagnetic brake needs to reach 14.4V when it starts working, and the voltage to maintain the coil working only needs to be above 2.4V.
[0068] The working principle is: when the forklift is braking, the microcontroller outputs a PWM signal BRAKE. This signal is amplified by U1 and then passes through the first resistor R1 to control the switch tube Q1 to turn on. In the initial 1s, the duty cycle of the PWM signal output by the microcontroller is the largest, which can ensure that the brake coil reaches the pull-in voltage. After 1s, the duty cycle is reduced to the minimum, and the coil voltage is maintained above the release voltage, thereby ensuring that the brake coil continues to work under the minimum operating voltage state. The function of the fourth resistor R4 is to make the VGS voltage of the switch tube Q1 less than the MOS turn-on voltage when the coil current is too large, thereby limiting the brake coil current. The VBK signal is used to detect the brake coil voltage. When the coil is short-circuited, VBK is high. When the MCU detects the short-circuit signal, it will turn off the PWM signal of BRAKE to turn off Q1.
[0069] The utility model is conducive to improving the working loss problem of electromagnetic brakes, improving energy utilization efficiency, reducing the loss of forklift controllers, and has the effect of energy saving and environmental protection. The protection circuit can ensure the safe and stable operation of the brake system.
[0070] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.
[0071] It should be noted that the above embodiments can be freely combined as needed. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention.
Claims
1. A forklift controller electromagnetic brake auxiliary circuit, It is characterized in that include: A driving circuit, used for receiving a PWM brake signal and outputting a switch control signal; A switch tube, connected to the driving circuit and the electromagnetic brake coil of the forklift controller, for receiving the switch control signal and controlling the electromagnetic brake coil of the forklift controller to work; The current limiting circuit is connected to the switch tube and is used to make the VGS voltage of the switch tube less than the conduction voltage of the switch tube when the current of the electromagnetic brake coil of the forklift controller exceeds a preset threshold, thereby limiting the current of the electromagnetic brake coil of the forklift controller.
2. The electromagnetic brake auxiliary circuit of a forklift controller according to claim 1, It is characterized in that The first end of the electromagnetic brake coil of the forklift controller is connected to the bus voltage output end for receiving the bus voltage to work; Among them, when it is within the preset time, the input voltage of the electromagnetic brake coil of the forklift controller reaches the pull-in voltage, and when it exceeds the preset time, the input voltage of the electromagnetic brake coil of the forklift controller is maintained above the release voltage, so that the electromagnetic brake coil of the forklift controller continues to work under the preset working voltage state.
3. The electromagnetic brake auxiliary circuit of a forklift controller according to claim 1, It is characterized in that Also includes: The detection circuit is connected to the second end of the switch tube, the current limiting circuit, and the electromagnetic brake coil of the forklift controller, and is used to detect the voltage of the electromagnetic brake coil of the forklift controller. When the detection circuit detects a short circuit signal, the output of the PWM brake signal is turned off to turn off the switch tube.
4. The electromagnetic brake auxiliary circuit of a forklift controller according to claim 1, It is characterized in that The driving circuit comprises: a driving chip and a first resistor; The input end of the driving chip is connected to the output end of the PWM brake signal, the output end of the driving chip is connected to the first resistor, and the first resistor is connected to the first end of the switch tube; The driving chip receives the PWM brake signal, and conducts the amplified PWM brake signal through the first resistor to turn on the switch tube, so that the electromagnetic brake coil of the forklift controller works normally.
5. The electromagnetic brake auxiliary circuit of a forklift controller according to claim 4, It is characterized in that The driving circuit further includes: a second resistor; The first end of the second resistor is connected to the first resistor and the first end of the switch tube; the second end of the second resistor is grounded.
6. The electromagnetic brake auxiliary circuit of a forklift controller according to claim 3, It is characterized in that The detection circuit comprises: a single chip microcomputer, a third resistor and a capacitor; The single chip microcomputer is connected to the second end of the switch tube and the electromagnetic brake coil of the forklift controller through the third resistor; the single chip microcomputer is connected to the current limiting circuit through the capacitor.
7. The electromagnetic brake auxiliary circuit of a forklift controller according to claim 1, It is characterized in that The current limiting circuit comprises: a fourth resistor; A first end of the fourth resistor is connected to the third end of the switch tube, and a second end of the fourth resistor is grounded.
8. The electromagnetic brake auxiliary circuit of a forklift controller according to claim 1, It is characterized in that Also includes: A diode is connected to a first end and a second end of the electromagnetic brake coil of the forklift controller.
9. The electromagnetic brake auxiliary circuit of a forklift controller according to claim 4, It is characterized in that The driving chip is a MOS driving chip.
10. An electromagnetic brake auxiliary circuit for a forklift controller according to any one of claims 1 to 9, It is characterized in that The switch tube is an NMOS tube.