Proximity switch test tool

Abstract

The utility model discloses a proximity switch test tool comprising a pedestal, a fixed code disc is sleeved in a code disc installation plate, the fixed code disc and the code disc installation plate are fixed on the upper part of the vertical surface of the pedestal through a shaft, an orthogonal encoder is installed on the shaft, and a Z-shaped baffle plate on the orthogonal encoder is fixed on the vertical surface of the pedestal. One group of proximity switches are mounted in through holes in the vertical surface of the base, the lead screw sliding table is mounted on the bottom surface of the base, the upper end of the lead screw sliding table is provided with a proximity switch bracket, and the front end of the proximity switch bracket is provided with a waist-shaped hole for adjusting the distance between the other group of proximity switches; effective measurement distances and accurate measurement distances of the same proximity switch to code discs made of different materials can be measured, effective measurement distances and accurate measurement distances of the code discs made of the same material and different proximity switches can be measured, and the distance between the two proximity switches with specific output waveforms and the distance between the proximity switches and the code discs can be measured when the code discs are different. Counting and measuring performance of the proximity switch and the encoder are compared, and error analysis or evaluation of whether the proximity switch can be used for replacing the encoder is carried out.

Description

Technical Field

[0001] The utility model relates to a testing tool, in particular to a proximity switch testing tool. Background Art

[0002] As a low-cost level detection component, proximity switches are widely used in the machinery industry. They can be used alone for level alarms, level limits, speed measurement, etc.; they are often used in combination as a low-cost alternative to encoders. For example, when used with components such as code disks or racks, two proximity switches form an orthogonal encoding element for measuring speed, depth or angle.

[0003] However, in the actual manufacturing process, it is often necessary to adjust the installation position of the proximity switch several times before the accurate detection distance and installation position can be determined. The detection distance of the proximity switch varies for materials of different materials. The detection range of proximity switches from different manufacturers is also different. The above points often require on-site rework, causing trouble for production personnel. Utility Model Content

[0004] The utility model provides a proximity switch testing tool for overcoming the defect in the prior art that the installation position of the proximity switch needs to be adjusted multiple times to determine the detection distance for materials of different materials.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] The utility model discloses a proximity switch testing tool, which comprises a base, a fixed code disk sleeved in a code disk mounting plate, and the two are fixed to the upper part of the vertical surface of the base through a shaft, an orthogonal encoder is mounted on the shaft, a Z-shaped baffle on the orthogonal encoder is fixed on the vertical surface of the base, a group of proximity switches are mounted in through holes on the vertical surface of the base, a lead screw slide is mounted on the bottom surface of the base, a proximity switch bracket is provided at the upper end of the lead screw slide, and a waist-shaped hole for adjusting the spacing of another group of proximity switches is opened at the front end of the proximity switch bracket.

[0007] Furthermore, the proximity switches are provided in two groups, one group having one and the other group having two.

[0008] Furthermore, a crank is provided at the tail of the shaft for driving the code disc to rotate.

[0009] Furthermore, a center hole is provided on the vertical surface of the base, and a retaining ring A and a rolling bearing are installed in the center hole. The end of the shaft passes through the retaining ring B, the retaining ring A and the rolling bearing in sequence and is connected to the code disk mounting plate. The retaining ring A is used to fix the rolling bearing to prevent it from moving relative to the base; the retaining ring B is used to prevent the shaft from moving relative to the rolling bearing.

[0010] Furthermore, the code disc is a flat disc with teeth on the edge.

[0011] Furthermore, a scale for calculating the detection distance is provided on the upper end of the side plate of the rocking screw slide.

[0012] The beneficial effects achieved by the present invention are as follows: in conjunction with a DC power supply and an oscilloscope, the effective measurement distance and accurate measurement distance of the same proximity switch for code disks of different materials can be determined, and the effective measurement distance and accurate measurement distance of different proximity switches for code disks of the same material can be determined; the distance between two proximity switches with specific output waveforms when different code disks are used and the distance between the proximity switch and the code disk can be determined; in conjunction with a DC power supply, an oscilloscope and an external control unit, the counting and measurement performance of the proximity switch and the encoder can be compared, and error analysis or an evaluation of whether the proximity switch can be used to replace the encoder can be performed. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0014] Figure 1 It is an explosion diagram of the utility model;

[0015] Figure 2 It is the orthogonal coding standard waveform of the present utility model.

[0016] In the figure: 1. Screw slide; 2. Proximity switch bracket; 3. Base; 4. Proximity switch; 5. Code disk; 6. Code disk mounting plate; 7. Rolling bearing; 8. Retaining ring A; 9. Retaining ring B; 10. Shaft; 11. Orthogonal encoder; 12. Crank handle. DETAILED DESCRIPTION

[0017] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention and are not used to limit the present invention.

[0018] Example 1

[0019] like Figure 1-2 As shown, a proximity switch testing tool includes a base 3, a fixed code disk 5 sleeved in the code disk mounting plate 6, and the two are fixed to the upper part of the vertical surface of the base 3 through a shaft 10. An orthogonal encoder 11 is fixedly mounted on the shaft 10, and the Z-shaped baffle on the orthogonal encoder 11 is fixed on the vertical surface of the base 3. A group of proximity switches 4 are installed in the through holes on the vertical surface of the base 3, and a screw slide 1 is installed on the bottom surface of the base 3. A proximity switch bracket 2 is provided at the upper end of the screw slide 1, and a waist-shaped hole is provided at the front end of the proximity switch bracket 2 to adjust the spacing of another group of proximity switches 4.

[0020] The proximity switches 4 are arranged in two groups, one group has one and the other group has two.

[0021] A crank 12 is provided at the tail of the shaft 10 for driving the code disc 5 to rotate.

[0022] A center hole is provided on the vertical surface of the base 3, in which a retaining ring A8 and a rolling bearing 7 are installed. The end of the shaft 10 passes through the retaining ring B9, the retaining ring A8 and the rolling bearing 7 in sequence and is connected to the code disk mounting plate 6.

[0023] The retaining ring A8 is used to fix the rolling bearing 7 to prevent it from moving relative to the base 2.

[0024] The retaining ring B9 is used to prevent the shaft 10 from moving relative to the rolling bearing 7.

[0025] Shaking the crank of the screw slide 1 drives the proximity switch bracket 2 and a set of two proximity switches 4 to move closer to or away from the code disk 5; the detection distance is calculated by the scale on the upper end of its side plate;

[0026] The proximity switch 4 is the tested component and is a non-contact level detection sensor;

[0027] The code disc 5 is a flat disc with teeth on the edge, which is the object to be detected;

[0028] The code disc mounting plate 6 is used to mount code discs 5 of various materials;

[0029] The shaft 10 with the orthogonal encoder 11 outputs a fixed number of pulses every time it rotates one circle. The number of pulses per rotation depends on its resolution, which serves as a calibration device.

[0030] The detection method of the proximity switch test fixture is as follows:

[0031] (1) Single proximity switch detection

[0032] Fix the proximity switch 4 to the waist hole at the front end of the proximity switch bracket 2, connect the output line of the proximity switch 4 to the oscilloscope, turn the crank 12 of the proximity switch bracket 2 to move the proximity switch 4 away from the code disk 5 to a position beyond the rated detection distance, then turn on the power and turn the crank 12 to make the code disk 5 rotate at a constant speed, turn the crank 12 of the proximity switch bracket 2 to make the proximity switch 4 slowly approach the code disk 5,

[0033] When the oscilloscope waveform shows a continuous square wave, record the scale - L1;

[0034] When the oscilloscope shows duty cycle = 50% (± 2%), record the scale - L2;

[0035] Stop the code disk 5, turn the crank 12 of the proximity switch bracket 2 to make the proximity switch 4 fit the code disk 5, and record the scale L3;

[0036] Turn the crank 12 of the proximity switch bracket 2 to move the proximity switch 4 about 1 mm away from the code disk 5. Turn the crank 12 again to rotate the code disk 5 at a constant speed. Turn the crank 12 of the proximity switch bracket 2 to slowly move the proximity switch 4 away from the code disk 5. When the oscilloscope shows a duty cycle of 50% (±2%), record the scale -L4.

[0037] So:

[0038] |L3-L1| is the effective detection distance of the proximity switch 4;

[0039] |L3-L2| to |L3-L4| is the distance range for accurate detection of the proximity switch 4.

[0040] (2) Two proximity switches of the same specification are used as orthogonal encoding elements

[0041] a. First, use method (1) to confirm the distance range of the two sets of proximity switches 4 that can be accurately detected;

[0042] b. Install two sets of proximity switches 4 at both ends of the waist hole of the proximity switch bracket 2, rotate the screw slide 1 to move the proximity switch 4 away from the code disk 5 to the scale corresponding to the accurate detection spacing, and connect the output lines of the two sets of proximity switches 4 to the two detection channels of the oscilloscope respectively.

[0043] Turn on the power and turn the crank 12 to make the code disk 5 rotate at a constant speed. Observe whether the oscilloscope waveform conforms to the orthogonal encoding waveform (the two waveforms have a phase difference of 90° and a duty cycle of 50% ± 10%. If not, stop the code disk 5 and adjust one group of proximity switches 4 to reduce the distance between the two. Repeat the test until the oscilloscope waveform conforms to the orthogonal encoding waveform. At this time, the distance between the proximity switches 4 is the optimal distance.

[0044] (3) Proximity switch performance comparison

[0045] Usage method (1) After testing a group of proximity switches 4, use them as the compared components, and the distance from the code disk 5 is the accurate detection distance;

[0046] After the proximity switches 4 to be compared are installed, power is turned on and the crank 12 is rotated to rotate the code disk 5 at a constant speed. An oscilloscope is used to compare the waveforms and duty cycle continuity of the two groups of proximity switches 4 when the duty cycle is about 50%.

[0047] (4) Verify the calibration results with the help of an external control unit

[0048] Verification of proximity switch 4 using orthogonal encoding with the help of PLC controller;

[0049] The quadrature encoder 11 is used as a comparison object;

[0050] PI2 is the orthogonal encoder count value of the compared orthogonal encoder 11, and the resolution is designed to be 512 (i.e., the encoder outputs 512 pulses per one rotation);

[0051] PI1 is the orthogonal encoding count value of the proximity switch 4 to be compared, and the number of teeth of the code disk 5 is designed to be 30;

[0052] The main code examples are as follows:

[0053] (*Variable definition*)

[0054] PI3: UINT; (*frequency count value input by system variable PI3*)

[0055] PI1: UINT; (*frequency count value input by system variable PI1*)

[0056] ROUND_PI3: UINT: = 0; (*The number of full revolutions of the encoder, the initial value is 0*)

[0057] ROUND_PI1: UINT: = 0; (*Number of full turns of the proximity switch, initial value is 0*)

[0058] ANGLE_PI3: LREAL; (*Calculated angle of encoder*)

[0059] ANGLE_PI1: LREAL; (*Calculated angle of proximity switch*)

[0060] C_PI1: UINT: = 0; (*Number of proximity switch overflows*)

[0061] C_PI3: UINT: = 0; (*Encoder count overflow times*)

[0062] (*The encoder pulse count for 5 revolutions of the code disk is 512, and the maximum variable is 65535; the proximity switch pulse count for 5 revolutions of the code disk is 30, and the maximum variable is 65535. Compare the angle values*)

[0063] IF PI3=65535THEN

[0064] C_PI3=C_PI3+1;

[0065] END_IF

[0066] IF PI1=65535THEN

[0067] C_PI1=C_PI1+1;

[0068] END_IF

[0069] ROUND_PI3:=TRUNC((PI3+C_PI3*65535) / 512); (*Number of encoder full revolutions*)

[0070] ROUND_PI1:=TRUNC((PI1+C_PI1*65535) / 30); (*Number of full turns of the proximity switch*)

[0071] ANGLE_PI3:=((PI3+C_PI3*65535) / 512-ROUND_PI3)*360;

[0072] ANGLE_PI1:=((PI1+C_PI1*65535) / 30-ROUND_PI1)*360;

[0073] According to the detection method (2), the two groups of proximity switches 4 are adjusted to the optimal spacing, the proximity switches 4 and the orthogonal encoder 11 are connected to the controller, the control program is run and monitored, the power is turned on and the handle 12 is turned to make the code disk 5 rotate at a constant speed, and after rotating N circles, the calculated angle values ​​of the orthogonal encoder 11 and the proximity switch 4 are counted and compared.

[0074] It should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will appreciate that they may modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, improvements, and the like that fall within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention. The terms used in the description of this application are intended only to describe specific embodiments and are not intended to limit the exemplary embodiments of the present invention. For ease of description, the dimensions of the various parts shown in the drawings are not drawn to scale. Technologies, methods, and devices known to persons skilled in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely illustrative and not limiting. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar reference numerals and letters denote similar items in the following figures. Therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0075] It should be noted that the terms "first," "second," etc. in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way are interchangeable where appropriate, so that the embodiments of this application can be implemented in an order other than those illustrated or described herein, and that the objects distinguished by "first," "second," etc. are generally of the same type, and do not limit the number of objects. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0076] It should be noted that, in the description of this application, the directions or positional relationships indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description. Unless otherwise specified, these directional terms do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of this application; the directional terms "inside and outside" refer to the inside and outside relative to the outline of each component itself.

Claims

1. A proximity switch test tool, characterized in that: It includes a base, a fixed code disk sleeved in the code disk mounting plate, and the two are fixed to the upper part of the vertical surface of the base through a shaft, an orthogonal encoder is installed on the shaft, and the Z-shaped baffle on the orthogonal encoder is fixed on the vertical surface of the base. A group of proximity switches are installed in the through holes on the vertical surface of the base, and the screw slide is installed on the bottom surface of the base. A proximity switch bracket is provided at the upper end of the screw slide, and a waist-shaped hole is opened at the front end of the proximity switch bracket to adjust the spacing of another group of proximity switches.

2. The proximity switch testing tool according to claim 1, characterized in that: The proximity switches are arranged in two groups, one group consists of one and the other group consists of two.

3. The proximity switch testing tool according to claim 1, characterized in that: The tail of the shaft is provided with a crank handle for driving the code disc to rotate.

4. The proximity switch testing tool according to claim 1, characterized in that: A center hole is provided on the vertical surface of the base, in which a retaining ring A and a rolling bearing are installed. The end of the shaft passes through the retaining ring B, retaining ring A and rolling bearing in sequence and is connected to the code disc mounting plate; The retaining ring A is used to fix the rolling bearing to prevent it from moving relative to the base; The retaining ring B is used to prevent the shaft from moving relative to the rolling bearing.

5. The proximity switch testing tool according to claim 1, characterized in that: The code disc is a flat disc with teeth on the edge.

6. The proximity switch testing tool according to claim 1, characterized in that: The upper end of the side plate of the lead screw slide is provided with a scale for calculating the detection distance.

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