阅读说明：本技术 微型计算机输入用开关 (Switch for microcomputer input ) 是由 山下明彦 古瀬达也 中田知里 铃木章平 于 2018-01-24 设计创作，主要内容包括：本发明提供一种即使在浸水时触电电蚀也少,能够可靠地检测开关的断开状态的微型计算机输入用开关。在具有构成开关(5)的一侧触电(6)和另一侧触电(7)的微型计算机输入用开关中,作为用于检测开关(5)的断开状态的电流,将输出脉冲波形的恒定电流施加于开关(5)。将恒定电流设为100mA以下的微小电流。一侧触电(6)或另一侧触电(7)与用于检测开关(5)的断开状态的电压阈值检测单元(4)连接,并具备控制部(8),控制部(8)基于电压阈值检测单元(4)的输出信号来判断开关(5)的断开状态。控制部(8)根据施加的电流超过预定的阈值(Va),判断为开关(5)为断开状态。(The invention provides a microcomputer input switch which is less in electric shock and electric erosion even when immersed in water and can reliably detect the off state of the switch. In a microcomputer input switch having a first side contact 6 and a second side contact 7 constituting a switch 5, a constant current of an output pulse waveform is applied to the switch 5 as a current for detecting an off state of the switch 5. The constant current is set to a minute current of 100mA or less. The one-side contact (6) or the other-side contact (7) is connected to a voltage threshold detection unit (4) for detecting the off-state of the switch (5), and is provided with a control unit (8), and the control unit (8) determines the off-state of the switch (5) on the basis of an output signal of the voltage threshold detection unit (4). The control unit (8) determines that the switch (5) is in the off state when the applied current exceeds a predetermined threshold value (Va).)

1. A switch for microcomputer input, having a first contact (6) and a second contact (7) constituting a switch (5),

as a current for detecting the off state of the switch (5), a constant current of an output pulse waveform is applied to the switch (5).

2. The switch for microcomputer input according to claim 1,

the constant current is a minute current of 100mA or less.

3. The switch for microcomputer input according to claim 1 or claim 2,

the one-side contact (6) or the other-side contact (7) is connected with a voltage threshold detection unit (4) for detecting the disconnection state of the switch (5),

and a control unit (8), wherein the control unit (8) determines the off state of the switch (5) based on the output signal of the voltage threshold detection unit (4),

the control unit (8) determines that the switch (5) is in the off state based on the fact that the applied current exceeds a predetermined threshold value (Va).

4. The switch for microcomputer input according to any one of claims 1 to 3,

the width (T1) of the pulse of the current applied to the switch (5) is set to a minimum value including a range in which the detected voltage value exceeds a threshold value (Pa).

5. The switch for microcomputer input according to claim 3,

the detection of the open state of the switch (5) is performed a plurality of times within the width (T1) of the pulse of current conducted to the switch (5).

6. The switch for microcomputer input according to claim 3,

when the detected voltage value exceeds a threshold value (Va), the current application is stopped.

7. The switch for microcomputer input according to claim 3,

the control unit (8) detects the off states of the plurality of switches in a predetermined order,

the sequence is set such that the detection interval of the off state of the switch requiring a fast response speed becomes short.

Technical Field

The present invention relates to a microcomputer input switch, and more particularly, to a microcomputer input switch applied to a manual switch for operating electrical equipment of a vehicle or the like.

Background

Conventionally, in a manual switch for operating electrical equipment of a vehicle such as a horn switch or a starter switch, there has been an attempt to prevent operation failure of the electrical equipment when the switch is immersed in water due to moisture such as rain.

Patent document 1 discloses the following structure: in a circuit of a brake switch for operating a brake lamp using an LED as a light source, in order to prevent the occurrence of leakage current caused by the electric shock and water immersion of a manual switch, when the manual switch is turned off and the brake lamp is operated, the ground of a semiconductor switch in the circuit is shared with the ground of the manual switch.

Disclosure of Invention

Problems to be solved by the invention

However, the switching circuit disclosed in patent document 1 has a problem of cost increase due to the need for two semiconductor switches. Further, the prevention of the galvanic corrosion by the current for detecting the open/close state of the switch has not been studied.

The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to provide a microcomputer input switch in which, in a non-waterproof switch, electric shock and corrosion are reduced even when the switch is immersed in water, and the off state of the switch can be reliably detected.

Means for solving the problems

In order to achieve the above object, a first feature of the present invention is that, in a microcomputer input switch having a first side contact (6) and a second side contact (7) constituting a switch (5), a constant current of an output pulse waveform is applied to the switch (5) as a current for detecting an off state of the switch (5).

Further, the second characteristic is that the constant current is a minute current of 100mA or less.

Furthermore, the third characteristic is that the one side contact (6) or the other side contact (7) is connected to a voltage threshold detection means (4) for detecting an off state of the switch (5), and a control unit (8) is provided, the control unit (8) determines the off state of the switch (5) based on an output signal of the voltage threshold detection means (4), and the control unit (8) determines that the switch (5) is in the off state when the applied current exceeds a predetermined threshold (Va).

In addition, according to a fourth aspect, a width (T1) of a pulse of the current applied to the switch (5) is set to a minimum value including a range in which the detected voltage value exceeds a threshold value (Va).

Furthermore, a fifth feature is that the detection of the open state of the switch (5) is performed a plurality of times within the width (T1) of the pulse of the current that is conducted to the switch (5).

In addition, according to a sixth feature, the current application is stopped when the detected voltage value exceeds a threshold value (Va).

Further, according to a seventh aspect, the control unit (8) detects the off states of the plurality of switches in a predetermined order set such that the detection interval of the off states of the switches requiring a high response speed becomes shorter.

Effects of the invention

According to the first feature, in the microcomputer input switch having the one-side contact (6) and the other-side contact (7) constituting the switch (5), a constant current of an output pulse waveform is applied to the switch (5) as a current for detecting an off state of the switch (5), so that an amount of current applied when detecting an on/off state of the switch can be reduced, and electric corrosion of the contacts during immersion can be minimized. Further, since the current having the pulse waveform is output, the off state of the switch can be detected with high accuracy by monitoring the pulse waveform of the current. Further, when the resistance value is increased by the oxide film in the case of a constant current, the oxide film is broken by increasing the voltage between contacts in order to allow a predetermined current to flow, and the generation of the oxide film can be suppressed. This can keep the on-resistance low.

According to the second feature, since the constant current is a minute current of 100mA or less, the progress of the contact erosion can be suppressed to the minimum.

According to the third feature, the one side contact (6) or the other side contact (7) is connected to a voltage threshold detection unit (4) for detecting an off state of the switch (5), and a control unit (8) for determining the off state of the switch (5) based on an output signal of the voltage threshold detection unit (4) is provided, and the control unit (8) determines that the switch (5) is in the off state based on the fact that the applied current exceeds a predetermined threshold value (Va), so that the off state of the switch can be reliably detected in a pulse waveform manner.

According to the fourth feature, since the width (T1) of the pulse of the current applied to the switch (5) is set to a minimum value including a range in which the detected voltage value exceeds the threshold value (Va), the detection time of the off state of the switch can be shortened, and the electrolytic corrosion during the water immersion can be suppressed to a minimum.

According to the fifth feature, since the detection of the off state of the switch (5) is performed a plurality of times within the width (T1) of the pulse of the current flowing through the switch (5), the detection accuracy of the off state of the switch can be improved.

According to the sixth aspect, since the current application is stopped when the detected voltage value exceeds the threshold value (Va), the time for applying the current can be shortened, and the galvanic corrosion during immersion can be minimized.

According to the seventh feature, the control unit (8) detects the off states of the plurality of switches in a predetermined order, and the order is set such that the detection interval of the off states of the switches requiring a high response speed is shortened, so that the response speed of the horn switch, the stop lamp switch, or the like can be increased.

Drawings

Fig. 1 is a schematic diagram (switch on state) of a switch circuit to which the switch structure of the present embodiment is applied.

Fig. 2 is a schematic diagram (switch off state) of a switch circuit to which the switch structure of the present embodiment is applied.

Fig. 3 is a graph showing a transition of a voltage of an input signal input to the voltage threshold detection means in a state where the switch is turned off.

Fig. 4 is a flowchart showing the procedure of the off state detection control 1 of the switch.

Fig. 5 is a flowchart showing the procedure of the off state detection control 2 of the switch.

Fig. 6 is a diagram showing changes in the switch electric shock when used for a long time in a submerged state.

Detailed Description

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Fig. 1 and 2 are schematic diagrams of a switch circuit 1 to which the switch structure of the present embodiment is applied. Fig. 1 shows an on state in which the switch 5 is closed, and fig. 2 shows an off state in which the switch 5 is open.

The switching circuit 1 includes: a switch 5 such as a horn switch that is switched on and off by a human operation; a transformer 2 for converting the power supply current into a minute constant current; a P-type FET3 that flows current from the source to the drain by applying a low voltage to the gate; a voltage threshold detection unit 4 for detecting a threshold value of the output voltage of the FET 3; and a control unit (microcomputer) 8 that determines the on/off state of the switch 5 based on the output signal of the voltage threshold detection unit 4.

The switch 5 as a microcomputer input switch is composed of a first contact 6 located on the voltage threshold detection unit 4 side and a second contact 7 located on the ground side. In the present embodiment, a constant current having an output pulse waveform is applied as a current for detecting the off state of the switch 5. In addition, the application of the constant current can be performed immediately before the detection timing.

Conventionally, in order to detect the off state of the switch 5, a method of continuously applying a current to the switch is employed. Therefore, there are the following problems: when the conductive liquid W is filled between the one-side contact 6 and the other-side contact 7, a leakage current flows out through the conductive liquid W, which makes it difficult to detect the off state of the switch 5, and electric corrosion occurs in the contacts due to the leakage current. Such a conductive liquid W may be generated from, for example, rainwater entering a handlebar switch case of a motorcycle, water during washing, or the like, in addition to seawater.

In the present embodiment, in the configuration in which the switch 5 is determined to be in the off state by the input signal to the voltage threshold detection means 4 exceeding the predetermined threshold, the constant current of the output pulse waveform is applied as the current for detecting the off state of the switch 5 immediately before the detection timing of the off state of the switch 5, so that the off state of the switch 5 can be reliably detected while preventing galvanic corrosion due to an electric shock in the state in which the switch 5 is immersed. Further, when the resistance value increases due to the oxide film generated when the oxide film is generated due to the constant current, the voltage between contacts increases to cause the predetermined current to flow, and the oxide film can be broken.

Fig. 3 is a graph showing a transition of the voltage of the input signal to the voltage threshold detection means 4 in the off state of the switch 5. As described above, the current applied to the switch 5 via the transformer 2 is a minute current of 100mA or less (for example, 7 m). This can suppress electric erosion due to electric shock.

In the present embodiment, the minute current is a pulse current having a pulse waveform. Thus, the off state of the switch can be easily detected by monitoring the pulse waveform of the current, and further, the amount of the applied current can be suppressed, thereby reducing the electric erosion of the electric shock.

At time t, 0, the switch is in the off state to be detected. At time t1, the application of the input signal to the voltage threshold detection unit 4 is started, and the first pulse of the minute constant current starts to rise. Further, since the off state of the switch 5 is determined based on whether or not the voltage of the pulse exceeds the threshold Va smaller than the peak voltage V2, the off state can be reliably detected even if there is an influence of the leakage current.

Here, the width T1 of the pulse of the applied constant current is set to a minimum value including a range in which the detected voltage value exceeds the threshold Va based on the peak voltage V2. This can shorten the detection time of the off state of the switch 5. In the graph, a state is shown in which a prescribed time T2 elapses from the start of application of the constant current at time T2, a prescribed time T3 elapses from the start of application of the constant current at time T3, and the output voltage based on the constant current reaches the peak voltage V2 at time T4.

In the present embodiment, in order to improve the detection accuracy of the off state of the switch 5, it can be set so that the detection of the off state of the switch 5 is performed a plurality of times within the width T1 of the pulse of the current flowing through the switch 5. Thus, for example, if the voltage V exceeds the threshold Va 5 times in succession, it is determined that the switch 5 is in the off state, and noise resistance can be improved.

Further, as another method, it may be set so that the application of the current is immediately stopped when the detected voltage value exceeds the threshold Va, thereby shortening the time for applying the current and minimizing the galvanic corrosion during the immersion.

On the other hand, the control unit 8 is configured to detect the off states of a plurality of switches such as a horn switch and a stop lamp switch in a predetermined order. In this case, the order of detection of the off state can be set such that the detection interval of the off state of the switch, which requires a high response speed, becomes short. This enables detection of the off state corresponding to the required response speed of the switch.

Fig. 4 is a flowchart showing a procedure of the off state detection control 1 of the switch 5 according to the present embodiment. The predetermined time period shown below corresponds to the graph of fig. 3. As the switch off state detection control, in step S1, detection of the off states of the plurality of switches is started. In step S2, the application of the minute constant current is started. In step S3, it is determined whether or not the application elapsed time T exceeds a predetermined time T2. If an affirmative determination is made in step S3, the process proceeds to step S4, where voltage detection is performed. On the other hand, if a negative determination is made in step S3, the process returns to the determination in step S3.

In step S5, it is determined whether or not the detection voltage V exceeds the threshold voltage Va. If an affirmative determination is made in step S5, the process proceeds to step S6, where it is determined that the switch is in the off state, and the application of the minute constant current is stopped in step S7, and the series of controls is ended. If a negative determination is made in step S5, steps S6 and S7 are skipped and the series of control is ended.

Fig. 5 is a flowchart showing a procedure of the off state detection control 2 of the switch 5 according to the present embodiment. As described above, when the detection is performed a plurality of times within the predetermined pulse width, for example, the voltage V exceeds the threshold Va 5 times consecutively, the energization can be stopped after the off determination of the switch is performed, and thus the detection can be performed with higher accuracy in a short time.

In step S10, detection of the off states of the plurality of switches is started. In step S11, the application of the minute constant current is started. In step S12, it is determined whether or not the application elapsed time T exceeds a predetermined time T2. If an affirmative determination is made in step S12, the process proceeds to step S13, where voltage detection is performed. On the other hand, if a negative determination is made in step S12, the process returns to the determination in step S12.

In step S14, it is determined whether or not the detection voltage V exceeds the threshold voltage Va. If an affirmative determination is made in step S14, the routine proceeds to step S15, where the disconnection detection counter is incremented by (+ 1). On the other hand, if a negative determination is made in step S14, step S15 is skipped and the process proceeds to step S16.

In step S16, it is determined whether or not the application elapsed time T is less than a predetermined time T3. If an affirmative determination is made in step S16, the process returns to step S13. On the other hand, if a negative determination is made in step S16, the process proceeds to step S17.

In step S17, it is determined whether or not the disconnection detection count value Nc exceeds 5 times. If an affirmative determination is made in step S17, the process proceeds to step S18, where it is determined that the switch is in the off state. Then, in step S19, the off detection counter is reset, and in step S20, the application of the minute constant current is stopped, and the series of controls is ended.

Fig. 6 is a diagram showing changes in the switch electric shock when used for a long time in a submerged state. (a) The state in which a current is applied by the method of the present embodiment is shown, and (b) the state in which a current is applied by the conventional method is shown. In the conventional embodiment of (b), since the current is continuously applied to the switch in order to detect the off state of the switch, the electrolytic corrosion rapidly proceeds, whereas in the present embodiment shown in (a), it is known that the electrolytic corrosion hardly occurs in the switching shock.

The configuration of the switch, the transformer, the FET, the voltage threshold detection means, the shape and configuration of the one-side contact and the other-side contact, the pulse width and the threshold value, and the like are not limited to the above-described embodiments, and various modifications are possible. The switch for microcomputer input of the present invention can be applied to switches of various vehicles and power units, and is not limited to a handlebar switch of a motorcycle.

Description of the symbols

1. a switching circuit; 2. transformer; 3. FET; 4. a voltage threshold detection unit; 5. switch; 6, one side is electrically shocked; 7. another side is shocked; 8. a control section; v2 · peak voltage of the pulse; va · threshold; w.conductive liquid.