Suspended stroke precision measuring device of single-pole double-throw microswitch

Abstract

The utility model discloses a suspension stroke precision measuring device of a single-pole double-throw microswitch, which comprises an oscilloscope, a grating scale sensor, a moving mechanism and a microswitch, and is characterized in that the moving mechanism is connected with a button of the microswitch through an electric signal and is used for pressing the button of the microswitch at a constant speed; the oscilloscope is in electric signal connection with the microswitch and is used for reading the waveform of the microswitch; the grating ruler sensor is in electric signal connection with the oscilloscope and used for collecting the number of pulses generated by displacement of the moving mechanism. According to the utility model, the common pin COM of the microswitch is controlled to move from the normally closed pin CN to the normally open pin ON through the button of the constant-speed microswitch of the moving mechanism, the distance of the suspension stroke is calculated by multiplying the speed of the moving mechanism by the time, and the accuracy is less than 1 micron; and meanwhile, the pulse count of the grating ruler is multiplied by the resolution for auxiliary verification, the structure is simple, the operation is simple, and the test speed and precision are also greatly improved.

Description

Technical Field

[0001] The utility model relates to the field of automatic detection of micro switches, in particular to a precise measuring device for the suspended stroke of a single-pole double-throw micro switch. Background Art

[0002] In automated production lines, micro switches are widely used in the control and detection of various mechanical equipment. For example, on conveyor belts, assembly lines and other equipment, micro switches can be used to detect the position, quantity, size and other parameters of the workpiece to achieve automated control and adjustment.

[0003] In the prior art, an external force is used to push the common pin (COM) of the micro switch from the normally closed pin (NC) to the normally open pin (NO). During the movement, both the NC pin and the NO pin are not connected to the COM pin. At this time, the COM pin is in a suspended state. The distance d measured from the common pin (COM) from the normally closed pin (NC) to the normally open pin (NO) is called the suspended stroke.

[0004] In the prior art, there are two methods for measuring the suspension travel of a micro switch: a mechanical measurement method: using a precise mechanical measuring tool (such as a caliper, micrometer or micrometer) to measure the suspension distance between contacts; and an electrical test method: by applying a voltage or current between the contacts of the micro switch and measuring its resistance or conductivity, the suspension distance between the contacts can be indirectly inferred.

[0005] The above methods have low measurement efficiency and low measurement accuracy, so there is a need to further improve the existing measurement scheme. Utility Model Content

[0006] In order to solve the above technical problems, a precise measuring device for the suspended stroke of a single-pole double-throw micro switch with high measuring efficiency and good measuring accuracy is proposed.

[0007] To achieve the above purpose, the technical solution adopted by the utility model is as follows: a precision measuring device for the suspended stroke of a single-pole double-throw micro switch, comprising an oscilloscope, a grating ruler sensor, a moving mechanism and a micro switch, wherein:

[0008] The moving mechanism is connected to the button of the micro switch through an electrical signal, and is used to press the button of the micro switch at a uniform speed;

[0009] The oscilloscope is connected to the micro switch electrical signal and is used to read the waveform of the micro switch;

[0010] The grating ruler sensor is connected with the moving mechanism and the oscilloscope electrical signal, and is used to collect the number of pulses generated by the displacement of the moving mechanism.

[0011] Preferably, the micro switch includes a common pin COM, a normally closed pin CN and a normally open pin ON, the button is arranged on the common pin COM, the normally closed pin CN and the normally open pin ON have a suspension stroke d, and the common pin COM moves from the normally closed pin CN to the normally open pin ON when the button is pressed.

[0012] Preferably, the normally closed pin CN is electrically connected to a CN signal pin of the oscilloscope, and the normally open pin ON is electrically connected to an ON signal pin of the oscilloscope.

[0013] Preferably, the oscilloscope and the micro switch are both connected to a switching power supply.

[0014] Preferably, a resistor RCN is provided between the switching power supply and the CN signal pin of the oscilloscope.

[0015] Preferably, a resistor RNO is provided between the switching power supply and the NO signal pin of the oscilloscope.

[0016] Beneficial technical effects of the utility model:

[0017] The utility model controls the common pin COM of the micro switch to move from the normally closed pin CN to the normally open pin ON by moving the button of the uniform-speed micro switch of the moving mechanism, and calculates the distance of the suspended stroke in the manner of multiplying the speed of the moving mechanism by the time, with an accuracy of less than 1 micron; at the same time, auxiliary calibration is performed by multiplying the pulse count of the grating ruler by the resolution, with an accuracy of no more than 2 microns. The utility model has a simple structure, simple operation, and greatly improves the speed and accuracy of the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is an overall structural block diagram of a precision measuring device for the suspended travel of a single-pole double-throw micro switch of the utility model;

[0019] Figure 2 This is a structural principle diagram of the micro switch in the utility model;

[0020] Figure 3 It is a schematic diagram of the overall principle of the utility model;

[0021] Figure 4 This is a schematic diagram of the test waveform captured by the oscilloscope in the utility model. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the utility model more clearly understood, the utility model is further described in detail below in conjunction with embodiments, but the scope of protection claimed in the utility model is not limited to the following specific embodiments.

[0023] like Figure 1-3As shown, the precision measuring device for the suspended travel of a single-pole double-throw micro switch includes an oscilloscope, a grating ruler sensor, a moving mechanism and a micro switch, wherein:

[0024] The moving mechanism is connected to the button of the micro switch through an electrical signal, and is used to press the button of the micro switch at a uniform speed. In the embodiment, the moving mechanism adopts a precision moving mechanism, such as an existing linear motor moving mechanism, or a servo motor moving mechanism, which can reciprocate at a uniform speed. The precision moving mechanism in this embodiment adopts an existing linear motor moving mechanism. The linear motor of the linear motor moving mechanism in this embodiment drives a push rod with a pressure sensor, and the push rod presses the button of the micro switch.

[0025] Specifically, the micro switch has a trigger button, and its structure is a bit like a seesaw, with a bracket in the middle. The default state is always NC end down and connected to COM. If the button is pressed, the NC end rises and the NO end is connected to COM; if the button is released, the NO end rises and the NC end is connected to COM again.

[0026] In this embodiment: the linear motor of the precision moving mechanism drives a push rod with a pressure sensor to move at a constant speed toward the button of the micro switch until it reaches the action trigger distance of the micro switch. If the pressure detected during this process is abnormal and exceeds the maximum allowable range, the movement is stopped. When the push rod presses the button of the micro switch, the NC side is disconnected first, and the end is suspended for a while, and then the NO is connected to the COM.

[0027] The oscilloscope is connected to the micro switch electrical signal and is used to read the waveform of the micro switch;

[0028] The grating ruler sensor is connected with the moving mechanism and the oscilloscope electrical signal, and is used to collect the number of pulses generated by the displacement of the moving mechanism.

[0029] Specifically, the principle of pulse collection by the grating ruler is as follows: the grating ruler is an existing optical instrument for precision distance measurement. The grating ruler is provided with a movable part, and the movable part is connected to the linear motor of the precision moving mechanism. A pulse will be output every time the movable part moves a minimum step. For example, a pulse signal can be output when it moves forward or backward by 2um. In this way, the distance moved by the moving part of the grating ruler can be determined by counting the number of pulse signals.

[0030] Specifically, the micro switch includes a common pin COM, a normally closed pin CN and a normally open pin ON, the common pin COM is provided with the button, the normally closed pin CN and the normally open pin ON have a suspension stroke d, and the common pin COM moves from the normally closed pin CN to the normally open pin ON when the button is pressed.

[0031] The normally closed pin CN is electrically connected to the CN signal pin of the oscilloscope, and the normally open pin ON is electrically connected to the ON signal pin of the oscilloscope. The oscilloscope collects electrical signals on the normally closed pin CN and the normally open pin ON through the CN signal pin and the ON signal pin.

[0032] Specifically, the oscilloscope and the micro switch are both connected to a switching power supply. A resistor RCN is provided between the switching power supply and the CN signal pin of the oscilloscope. A resistor RNO is provided between the switching power supply and the NO signal pin of the oscilloscope.

[0033] The working principle and process of the utility model are as follows:

[0034] The moving mechanism moves at a constant speed and presses the button of the micro switch. When the NC pin begins to disconnect, the COM pin separates from the NC pin, and under the action of the pull-up resistor RNC, the CN signal of the CN signal pin of the oscilloscope begins to rise; when the COM pin contacts the NO pin, the NO signal of the NO signal pin of the oscilloscope begins to fall. Contact jitter may cause waveform jitter, such as Figure 4 However, it does not affect the final measurement results.

[0035] Use an oscilloscope to capture the time t from the rise of the NC signal to the fall of the NO signal. Then multiply the time by the speed of the moving mechanism v to get the suspended stroke d, that is, d = v*t. The error mainly comes from the moving speed of the moving mechanism.

[0036] In order to more accurately obtain the suspended stroke d and monitor the moving speed of the moving mechanism, a grating scale sensor is added. The number of pulses n of the grating scale sensor is calculated and then multiplied by the resolution f of the grating scale pulse. The suspended stroke d can also be obtained, that is, d=n*f.

[0037] At this time, the measurement error mainly depends on the resolution of the grating scale pulse, and its resolution can be further improved by pulse frequency doubling.

[0038] In addition, according to the grating ruler signal pulse count displayed on the oscilloscope and the time resolution of the oscilloscope, the movement speed of the moving mechanism can be verified, and it can be judged whether it is uniform motion. The principle of judging uniform motion is: each pulse output by the grating ruler represents a step distance, and these pulses will be displayed on the oscilloscope. If the pulse width is consistent, that is, the time interval displayed on the oscilloscope is consistent, it means that the moving mechanism is moving at a uniform speed.

[0039] After actual testing, the utility model has found that when the suspension stroke is small, the repetition accuracy is less than 1 micron by multiplying the speed of the moving mechanism by time; when the suspension stroke is large, the repetition accuracy is less than 2 microns by multiplying the pulse count of the grating ruler by the resolution for auxiliary verification. If the grating ruler signal uses frequency doubling counting, the accuracy can be further improved. The test speed and accuracy are greatly improved.

[0040] According to the disclosure and teaching of the above description, those skilled in the art to which the utility model belongs can also change and modify the above implementation. Therefore, the utility model is not limited to the specific implementation methods disclosed and described above, and some modifications and changes to the utility model should also fall within the scope of protection of the claims of the utility model. In addition, although some specific terms are used in this specification, these terms are only for convenience and do not constitute any limitation to the utility model.

Claims

1. A precision measuring device for the suspended travel of a single-pole double-throw micro switch, characterized in that: It includes an oscilloscope, a grating ruler sensor, a moving mechanism and a micro switch, among which: The moving mechanism is connected to the button of the micro switch through an electrical signal, and is used to press the button of the micro switch at a uniform speed; The oscilloscope is connected to the micro switch electrical signal and is used to read the waveform of the micro switch; The grating ruler sensor is connected with the moving mechanism and the oscilloscope electrical signal, and is used to collect the number of pulses generated by the displacement of the moving mechanism.

2. A device for precisely measuring the suspended travel of a single-pole double-throw micro switch as claimed in claim 1, characterized in that: The micro switch includes a common pin COM, a normally closed pin CN and a normally open pin ON. The button is arranged on the common pin COM. The normally closed pin CN and the normally open pin ON have a suspension stroke d. The common pin COM moves from the normally closed pin CN to the normally open pin ON when the button is pressed.

3. A device for precisely measuring the suspended travel of a single-pole double-throw micro switch as claimed in claim 2, characterized in that: The normally closed pin CN is electrically connected to the CN signal pin of the oscilloscope, and the normally open pin ON is electrically connected to the ON signal pin of the oscilloscope.

4. A device for precisely measuring the suspended travel of a single-pole double-throw micro switch as claimed in claim 3, characterized in that: The oscilloscope and the micro switch are both connected to a switching power supply.

5. The device for accurately measuring the suspended travel of a single-pole double-throw micro switch according to claim 4, characterized in that: The switching power supply and the CN signal pin of the oscilloscope are provided with a resistor RCN.

6. A device for precisely measuring the suspended travel of a single-pole double-throw micro switch as claimed in claim 5, characterized in that: The switching power supply and the NO signal pin of the oscilloscope are provided with a resistor RNO.

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