An experimental device for verifying the quick-return characteristic of a crank-slider mechanism

Abstract

The present invention discloses an experimental device for verifying the quick-return characteristic of a crank-slider mechanism, which relates to the technical field of verifying the quick-return characteristic, and includes a crank-slider mechanism, at least one microswitch and a paper tape dotting mechanism. The microswitch is installed at the extreme position where the crank in the crank-slider mechanism swings leftward and / or rightward, and the paper tape dotting mechanism is electrically connected to the microswitch, so as to achieve the purpose of simply and intuitively verifying the quick-return characteristic.

Description

Technical Field

[0001] The present invention relates to the technical field of quick-return characteristic verification, and particularly to an experimental device for verifying the quick-return characteristic of a crank-slider mechanism. Background Art

[0002] As basic knowledge for the development of the manufacturing industry, the quick-return characteristic is widely applied in industrial practice, and its application value is also huge. It plays a crucial role in improving the working efficiency of machines. The research on the quick-return characteristic has developed well both at home and abroad. However, in the design and development of experimental verification devices for the quick-return characteristic, there are deficiencies in finished products or design schemes at home and abroad. There are many literatures at home and abroad that specifically and detailedly analyze and verify the specific theoretical research on the quick-return characteristic, including crank-rocker mechanisms, crank-slider mechanisms, crank-slider mechanisms, and unequal-length double-crank mechanisms. Even the research on the application of the quick-return characteristic of these mechanisms has developed very maturely. However, the research on experimental verification devices for the quick-return characteristic is very lagging.

[0003] For beginners, it is relatively abstract and not intuitive to analyze and study the quick-return characteristic by the instantaneous center method and the analytical method. Using computer simulation requires a complex mathematical theory, which is too difficult for novices. Summary of the Invention

[0004] The present invention provides an experimental device for verifying the quick-return characteristic of a crank-slider mechanism, so as to achieve the purpose of simply and intuitively verifying the quick-return characteristic.

[0005] To achieve the above object, the present invention provides the following solution:

[0006] An experimental device for verifying the quick-return characteristic of a crank-slider mechanism includes a crank-slider mechanism, and further includes at least one microswitch and a paper tape dotting mechanism. The microswitch is installed at the extreme position where the crank in the crank-slider mechanism swings leftward and / or rightward, and the paper tape dotting mechanism is electrically connected to the microswitch.

[0007] The working principle of this device is as follows: The crank in the crank-slider mechanism rotates at a constant speed, driving the rocker to swing left and right. When the rocker swings to the extreme position on the left and right, it touches the microswitch installed at the extreme position, and the dotting device electrically connected to the microswitch starts to dot on the paper tape moving at a constant speed. The stroke speed ratio coefficient of the crank-rocker mechanism is calculated based on the distance between adjacent two points, and the verification and measurement of the quick-return characteristic of the mechanism are completed. The device is simple and does not require a large amount of theoretical basis and a large amount of calculations for computer simulation. The experimental process and results are simple and intuitive, which is convenient for novices to understand and verify the quick-return characteristic.

[0008] Further, the crank-slider mechanism includes an experimental platform provided with a first through hole and a second through hole, a crankshaft passing through the first through hole, a crank wheel mounted on the crankshaft and rotating coaxially with the crankshaft, a first motor with an output shaft connected to the crankshaft, a guide rod shaft passing through the second through hole, a guide rod fixedly mounted on the guide rod shaft and rotating around the axis of the guide rod shaft, and a connecting member rotatably mounted on the crank wheel and slidably connected to the guide rod. The crank wheel and the guide rod are both on the same side of the experimental platform, and the rotation axis of the connecting member is parallel to the plane of the axis of the crank wheel.

[0009] After the motor is started, the crank wheel is kept rotating at a constant speed through the crankshaft. The guide rod connected by the connecting member on the crank wheel swings left and right around the guide rod shaft. When the guide rod swings to the leftmost or rightmost position, it is the limit position of the guide rod swing. The process of the guide rod swinging from the left and right limit positions towards the center of the crank wheel has the quick-return characteristic. The device is simple and convenient for understanding and experimentation.

[0010] Further, a first chute with an axis passing through the center of the crank wheel is provided on the crank wheel. A first slider is installed in the first chute. A fixing bolt is provided on the first slider. The connecting member is rotatably connected to the first slider. A first scale is provided on the crank wheel for marking the distance between the rotation axis of the connecting member and the axis of the crank wheel.

[0011] This structure changes the length of the crank by changing the distance between the first slider and the center of the crank wheel. The first scale is used to mark the distances between points on the first chute and the center of the crank wheel. During the experiment, the position of the first slider is adjusted to the required position according to the first scale, and the fixing bolt is tightened to fix the first slider, and then the experiment is carried out, ensuring the diversity of the experimental data when the device verifies the quick-return characteristic and making the experimental results more persuasive.

[0012] Further, the device further includes a data acquisition structure. The data acquisition structure includes a linkage swing rod fixedly mounted on the guide rod shaft and rotating around the axis of the guide rod shaft, a main swing rod and a sub-swing rod respectively rotatably connected to the guide rod shaft. A microswitch is installed on the main swing rod and / or the sub-swing rod. The guide rod is parallel to the plane of the linkage swing rod.

[0013] When the crank wheel drives the guide rod to swing, the linkage swing rod swings synchronously with the guide rod. Adjust the main swing rod and the auxiliary swing rod to the left and right extreme positions of the linkage swing rod and fix them. When the linkage swing rod swings to the left and right extreme positions, it touches the micro switch, causing the dotting device to dot. When directly using the guide rod to touch the micro switch, it is inconvenient to adjust the position of the micro switch, and large experimental errors are likely to occur. The linkage swing rod swings synchronously with the guide rod, touches the micro switch through the linkage swing rod, and installs the micro switch on the main swing rod and the auxiliary swing rod, which is convenient to adjust the position of the micro switch according to the left and right extreme positions of the linkage swing rod.

[0014] Furthermore, the data acquisition structure further includes a second slider and a second chute that cooperate with each other, a first connecting rod and a second connecting rod that are respectively rotatably connected to the second slider to form a linkage mechanism. The second chute is fixedly installed on the experimental platform, and the center line of the second chute passes through the axis line of the guide rod shaft. The first connecting rod is rotatably connected to the main swing rod, the second connecting rod is rotatably connected to the auxiliary swing rod. The main swing rod, the first connecting rod, the second connecting rod, and the auxiliary swing rod form a planar four-bar mechanism, and the first connecting rod and the second connecting rod are of equal length.

[0015] When the crank wheel of this device rotates, the distances of the left and right swings of the guide rod are equal. By manually adjusting the positions of the main swing rod and the auxiliary swing rod, it is easy to have a situation where the left and right included angles are not equal. In this structure, the first connecting rod and the second connecting rod are of equal length. Therefore, the inner area of the planar four-bar mechanism formed by the main swing rod, the first connecting rod, the second connecting rod, and the auxiliary swing rod is a rhombus, and the second slider at its connection point can only slide up and down in the second chute. When the main swing rod rotates, the rhombic planar four-bar mechanism makes the auxiliary swing rod rotate synchronously and the left and right included angles are equal. Therefore, during the experiment, only the position of the main swing rod needs to be accurately adjusted, which is convenient to operate and has high precision.

[0016] Furthermore, the data acquisition structure further includes a cam rotatably connected to the experimental platform and an elastic member for making the main swing rod contact the cam. The cam is used to adjust the included angle between the main swing rod and the auxiliary swing rod.

[0017] In this structure, the elastic member applies a force to the main swing rod to rotate inward, and the cam contacts the inner side of the main swing rod to prevent the main swing rod from rotating inward, achieving the purpose of fixing the main swing rod, and changing the included angle between the main swing rod and the auxiliary swing rod by rotating the cam, cooperating with the left and right extreme positions of the linkage swing rod.

[0018] Furthermore, the cam is provided with a second scale, which corresponds to the first scale one by one. It is convenient to adjust the cam to make the included angle between the main swing rod and the auxiliary swing rod equal to the swing included angle of the guide rod.

[0019] Further, the rotation center line of the cam lies on the plane formed by the axis line of the crankshaft and the axis line of the guide rod shaft. The distance between each second scale on the cam and the rotation center of the cam corresponds to the corresponding first scale, which is obtained through calculation, and the shape of the cam is designed based on this. This structure makes the calculation simple and facilitates the determination of the shape of the cam and the marking of the scales.

[0020] Further, the paper tape dotting mechanism includes a base, a second motor installed on the base, a dotting pen core driven by a telescopic structure, a first shaft, a second shaft, a clamping shaft, and a paper roll shaft that are arranged in parallel on the base, and a paper roll cylinder sleeved on the paper roll shaft. The second motor is used to provide a steering force for the first shaft and the second shaft. The telescopic structure is electrically connected to the microswitch. The clamping shaft and the first shaft are used to clamp the paper tape. The first shaft and the second shaft rotate synchronously to draw out the paper tape in the paper roll cylinder. The dotting pen core is used to dot on the paper tape.

[0021] In this mechanism, the paper tape is stored in the paper roll shaft. After the paper tape is led out from the paper roll shaft, it is wound around the second shaft and the first shaft in sequence. The first shaft and the second shaft are driven by the second motor and rotate synchronously and at a constant speed in the same direction. The clamping shaft and the first shaft clamp the paper tape, and the generated frictional force drives the paper tape to move. When the crank-slider mechanism is started, this paper tape dotting mechanism is started simultaneously. When the microswitch is triggered, the telescopic structure drives the dotting pen core to dot on the paper tape.

[0022] Further, the paper tape dotting mechanism further includes an axial distance adjuster, which is used to adjust the axial distance between the clamping shaft and the first shaft. It is used to finely adjust the clamping shaft to prevent the paper tape from loosening, affecting the moving speed of the paper tape and causing a large error in the experimental results.

[0023] One or more technical solutions provided by the present invention have at least the following technical effects or advantages:

[0024] (1) This device verifies the quick-return characteristic through the crank-slider mechanism and the paper tape dotting mechanism. The device has a simple structure, and the verification process and results are intuitive and clear;

[0025] (2) The length of the crank in this device can be adjusted, enabling the diversity of experimental data;

[0026] (3) In this device, the main swing rod and the auxiliary swing rod are connected through a rhombic four-bar mechanism to prevent deviation when adjusting the included angle;

[0027] (4) This device solves the problem of the change in the swing limit position of the guide rod caused by the change in the length of the crank by designing the shape of the cam. Description of the Drawings

[0028] The accompanying drawings described herein are used to provide a further understanding of the embodiments of the present invention, form a part of the present invention, and do not limit the embodiments of the present invention;

[0029] Figure 1 is a schematic diagram of the overall structure of the device in the present invention;

[0030] Figure 2 is a schematic diagram of the crank-slider mechanism in the present invention;

[0031] Figure 3 is a schematic diagram of the data acquisition structure in the present invention;

[0032] Figure 4 is a front view schematic diagram of the paper tape dotting mechanism in the present invention;

[0033] Figure 5 is a rear view schematic diagram of the paper tape dotting mechanism in the present invention;

[0034] Figure 6 is a schematic diagram of the shaft spacing adjuster structure in the present invention;

[0035] Figure 7 is a design diagram of the cam reverse method in the present invention;

[0036] Figure 8 is a diagram of the dotted paper tape in the present invention;

[0037] Among them, 1 - crank-slider mechanism, 2 - data acquisition structure, 3 - paper tape dotting mechanism, 4 - crankshaft, 5 - crank wheel, 6 - first slider, 7 - connecting piece, 8 - guide rod, 9 - guide rod shaft, 10 - experimental platform, 11 - first chute, 12 - linkage swing rod, 13 - main swing rod, 14 - auxiliary swing rod, 15 - microswitch, 16 - second slider, 17 - second chute, 18 - first connecting rod, 19 - second connecting rod, 20 - cam, 21 - elastic member, 22 - base, 23 - second motor, 24 - telescopic mechanism, 25 - dotting pen core, 26 - first shaft, 27 - second shaft, 28 - clamping shaft, 29 - paper roll shaft, 30 - paper roll cylinder, 31 - paper tape, 32 - shaft spacing adjuster, 33 - sliding rod, 34 - third slider, 35 - bolt. Detailed implementation manners

[0038] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation manners. It should be noted that, without conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0039] In the following description, many specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention may also be implemented in other ways different from those described within the scope hereof. Therefore, the scope of protection of the present invention is not limited by the specific embodiments disclosed below.

[0040] Embodiment 1

[0041] This embodiment provides an experimental device for verifying the quick-return characteristic of a crank-slider mechanism. As Figure 1 shown, it includes a crank-slider mechanism 1, and also includes at least one microswitch and a paper tape dotting mechanism 3. The microswitch is installed at the extreme positions where the crank in the crank-slider mechanism 1 swings leftward and / or rightward, and the paper tape dotting mechanism 3 is electrically connected to the microswitch.

[0042] Among them, preferably two microswitches are installed, respectively at the extreme positions of the left and right swings of the slider, to improve the experimental efficiency. And the microswitch includes single-pole type, double-pole type and multi-pole type microswitches. Preferably, the double-pole type microswitch can control the dotting of the dotter of a paper tape dotting mechanism 3 simultaneously, and can also control the paper tape dotting mechanism 3 alone. The paper tape dotting mechanism 3 works in a touch-type dotting manner, that is, whether to dot is controlled by the opening and closing of the microswitch. The dotter in the paper tape dotting mechanism 3 includes an electromagnetic dotter or an electric spark dotter.

[0043] In a more preferred embodiment, as Figure 2 shown, the crank-slider mechanism 1 includes an experimental platform 10 provided with a first through hole and a second through hole, a crankshaft 4 passing through the first through hole, a crank wheel 5 installed on the crankshaft 4 and rotating coaxially with the crankshaft 4, a first motor whose output shaft is connected to the crankshaft 4, a slider shaft 9 passing through the second through hole, a slider 8 fixedly installed on the slider shaft 9 and rotating around the axis of the slider shaft 9, and a connecting member 7 rotatably installed on the crank wheel 5 and used for slidably connecting with the slider 8. The crank wheel 5 and the slider 8 are both on the same side of the experimental platform 10, and the rotation axis of the connecting member 7 is parallel to the plane of the axis of the crank wheel 5.

[0044] Among them, the experimental platform 10 has vertical and horizontal types, etc. Preferably, a vertical experimental platform is used, which is convenient for the installation and operation of each component. The first through hole and the second through hole can be distributed at any position on the experimental platform 10. Preferably, they are vertically distributed, so that the extreme positions of the swing of the slider 8 are on the left and right sides of the crank wheel 5, which is convenient for novices to understand the principle of the device and for subsequent calculations; the crankshaft 4 is connected to the first through hole through a bearing, and the slider shaft 9 is connected to the second through hole through a bearing, to prevent damage to the crankshaft 4 and the slider shaft 9, resulting in experimental errors; the installation methods between the crank wheel 5 and the crankshaft 4 and between the slider 8 and the slider shaft 9 include bolt connection, key connection and mortise and tenon connection, etc. Preferably, key connection is used.

[0045] In addition, the connecting member 7 and the guide rod 8 cooperate with each other to slide. Therefore, the connecting member 7 can be used as a chute, and the guide rod 8 slides in the chute. Alternatively, a chute can be provided on the guide rod 8, and the connecting member 7 is slidably connected as a slider. Preferably, the connecting member 7 is used as a chute, which has a simple structure, and the shape of the connecting member 7 changes according to the shape of the guide rod 8. Preferably, it is an annular structure, and the guide rod 8 is inserted into the annular structure for restriction to prevent it from derailing.

[0046] In a more preferred embodiment, as Figure 2 shown, a first chute 11 with an axis passing through the center of the crank wheel 5 is provided on the crank wheel 5. A first slider 6 is installed in the first chute 11. A fixing bolt is provided on the first slider 6. The connecting member 7 is rotatably connected to the first slider 6. A first scale for marking the distance between the rotation axis of the connecting member 7 and the axis of the crank wheel 5 is provided on the crank wheel 5.

[0047] Among them, the length of the first chute 11 is set according to experimental requirements, and can be any value greater than 0 and less than the radius of the crank wheel 5. The total length of the first scale is equal to the length of the first chute 11. The interval between adjacent scale values is set according to experimental requirements, including 1mm, 2mm, 5mm, 10mm, etc., preferably 5mm. After the first slider 6 moves to the position required by the experiment, tighten the fixing bolt to make it relatively fixed with the crank wheel 5. The fixing bolt can be a hexagonal screw or a cross-slot screw, etc.

[0048] In a more preferred embodiment, as Figure 3 shown, the device further includes a data acquisition structure 2. The data acquisition structure 2 includes a linkage swing rod 12 fixedly installed on the guide rod shaft 9 and rotating around the axis of the guide rod shaft 9, a main swing rod 13 and a sub-swing rod 14 respectively rotatably connected to the guide rod shaft 9. A microswitch 15 is installed on the main swing rod 13 and / or the sub-swing rod 14. The guide rod 8 is parallel to the plane of the linkage swing rod 12.

[0049] Among them, the connection method between the linkage swing rod 12 and the guide rod shaft 9 includes bolt connection, key connection, tenon and mortise connection, etc., preferably key connection. And when the linkage swing rod 12 and the guide rod 8 are respectively key-connected to the guide rod shaft 9, the installation positions of the keys are the same, that is, the center lines of the key grooves are collinear to reduce errors. The rotational connection between the main swing rod 13 and the sub-swing rod 14 and the guide rod shaft 9 adopts a clearance fit. Preferably, a microswitch 15 is installed on both the main swing rod 13 and the sub-swing rod 14, respectively corresponding to the left and right extreme positions of the guide rod.

[0050] In a more preferred embodiment, as Figure 3As shown, the data acquisition structure 2 further includes a second slider 16 and a second chute 17 that cooperate with each other, a first link 18 and a second link 19 that are respectively rotatably connected to the second slider 16 to form a linkage mechanism. The second chute 17 is fixedly installed on the experimental platform 10, and the center line of the second chute 17 passes through the axis line of the guide rod shaft 9. The first link 18 is rotatably connected to the main swing rod 13, and the second link 19 is rotatably connected to the secondary swing rod 14. The main swing rod 13, the first link 18, the second link 19, and the secondary swing rod 14 form a planar four-bar mechanism, and the first link 18 and the second link 19 are of equal length.

[0051] Among them, the second chute 17 is a groove body or two parallel sliders, and is fixedly connected to the experimental platform 10 by bolts. The rotational connections in this embodiment are all two degrees of freedom.

[0052] In a more preferred embodiment, as Figure 3 shown, the data acquisition structure 2 further includes a cam 20 rotatably connected to the experimental platform 10 and an elastic member 21 for bringing the main swing rod 13 into contact with the cam 20. The cam 20 is used to adjust the angle between the main swing rod 13 and the secondary swing rod 14.

[0053] Among them, the shape of the cam 20 is calculated based on the limit positions at different lengths of the crank. The elastic member 21 can be a helical spring, a rubber spring, etc. A helical spring is preferred. When the helical spring is arranged on the right side of the main swing rod 13, it is a tension spring, and when it is arranged on the left side of the main swing rod 13, it is a thrust spring.

[0054] In a more preferred embodiment, as Figure 3 shown, the cam is provided with second scales, and the second scales correspond to the first scales one by one. The rotational center line of the cam is located in the plane formed by the axis line of the crankshaft and the axis line of the guide rod shaft.

[0055] The distance between each second scale on the cam and the rotational center of the cam corresponds to the corresponding first scale, which is calculated and used to design the shape of the cam.

[0056] In a more preferred embodiment, as Figure 4 and 5As shown, the paper tape dotting mechanism 3 includes a base 22, a second motor 23 installed on the base 22, a dotting pen core 25 driven by a telescopic structure 24, a first shaft 26, a second shaft 27, a clamping shaft 28 and a paper roll shaft 29 that are arranged in parallel on the base 22, and a paper roll 30 sleeved on the paper roll shaft 29. The second motor 23 is used to provide a steering force for the first shaft 26 and the second shaft 27. The telescopic structure 24 is electrically connected to the microswitch 15. The clamping shaft 28 and the first shaft 26 are used to clamp the paper tape 31. The first shaft 26 and the second shaft 27 rotate synchronously to draw out the paper tape in the paper roll 30. The dotting pen core 25 is used to dot on the paper tape.

[0057] Among them, the second motor 23 is connected to the first shaft 26 and the second shaft 27 by gears or belts, preferably gears. The telescopic structure 24 includes an electromagnet and a spring. After the electromagnet is energized, it pushes the dotting pen core 25. The spring can be a tension spring or a thrust spring, which is used to reset the dotting pen core 25. A sleeve for supporting the paper tape is sleeved on the first shaft 26, the second shaft 27 and the clamping shaft 28, which can be a rubber sleeve, a wooden sleeve, a plastic sleeve, etc., preferably a rubber sleeve with a relatively large friction force.

[0058] In a more preferred embodiment, as Figure 6 shown, the paper tape dotting mechanism 3 further includes an axial distance adjuster 32, and the axial distance adjuster 32 is used to adjust the axial distance between the clamping shaft 28 and the first shaft 26.

[0059] There are two axial distance adjusters 32, which are respectively connected to both ends of the clamping shaft 28, and include a slide rod 33, a third slider 34 and a bolt 35. The third slider 34 is connected to the clamping shaft 28 and slides on the slide rod 33. By screwing the bolt 35, the third slider 34 moves up and down, so as to adjust the axial distance between the clamping shaft 28 and the first shaft 26.

[0060] Embodiment 2

[0061] On the basis of Embodiment 1, the cam profile is designed by the cam reverse method. As Figure 7 shown, the steps include:

[0062] Step 1: Take the connection line between the axis center of the guide rod shaft and the rotation center of the cam as the y-axis, and the x-axis is located on the upper surface of the cam and perpendicular to the y-axis;

[0063] Step 2: In the cam reverse method, when the axis center of the guide rod shaft rotates through an angle δ relative to the cam and the swing center of the main swing rod is at positions A and B in the figure, its angular displacement is

[0064] Step 3: From the structural characteristics of the crank-slider mechanism, it can be obtained that the angle between the crank and the slider is 90° when the mechanism reaches the limit position. According to the crank length, the limit swing angle α of the slider corresponding to this crank length is calculated.

[0065] Step 4: Through mathematical calculations, the coordinates of the cam profile are obtained as follows:

[0066]

[0067]

[0068] Step 5: Substitute different crank lengths to obtain different coordinates.

[0069] Step 6: On the premise of ensuring that the contact point position between the cam and the swing rod remains unchanged, smoothly connect each coordinate point to form the outer contour of the cam.

[0070] Step 7: In order to reduce errors, mark the corresponding crank lengths at the positions of each coordinate point on the cam, so that when the scale aligns with the pointer, the center of curvature of the contact point of the swing rod coincides with the calculated theoretical contact point. Process the outer contour of the cam according to the above requirements to complete the design of the cam.

[0071] In this embodiment, the crank lengths are taken as 45mm, 50mm, 55mm, etc., and the following table is calculated:

[0072] Crank length 40 45 50 55 60 65 70 75 80 X coordinate of point -19.1297 -10.5409 -0.1663 11.3911 23.2867 34.4841 43.8399 50.2184 52.6244 Y coordinate of point 31.6762 37.2041 40.4546 40.7900 37.7388 31.0810 20.9566 7.8514 -7.3381 Oscillation angle α of the guide bar 10.015 11.2828 12.5559 13.8352 15.1217 16.4160 17.7189 19.0314 20.3544

[0073] Embodiment 3

[0074] On the basis of the above embodiments, the results of the quick-return characteristic experiment of this device are shown by the stroke speed ratio coefficient K of the crank-slider mechanism. The paper tape moves at a constant speed, and the dotting pen tip makes a series of dots on the paper tape. The distances between adjacent two points are one long and one short. The long distance is represented by s1, and the short one is represented by s2. As Figure 8 shown, calculate the stroke speed ratio coefficient K of the crank-slider mechanism

[0075]

[0076] To improve the accuracy, several s1 and s2 can be measured, and the average value of the calculated stroke speed ratio coefficients is taken.

[0077] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they know the basic creative concepts. Therefore, the appended claims are intended to be construed to include the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0078] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims

1. An experimental device for verifying the quick-return characteristic of a crank-slider mechanism, comprising a crank-slider mechanism (1), characterized in that, It also includes at least one microswitch and a paper tape dotting mechanism (3). The microswitch is installed at the extreme positions where the crank in the crank-slider mechanism (1) swings leftward and / or rightward. The paper tape dotting mechanism (3) is electrically connected to the microswitch; The crank-slider mechanism (1) includes an experimental platform (10) provided with a first through hole and a second through hole, a crankshaft (4) passing through the first through hole, a crank wheel (5) installed on the crankshaft (4) and rotating coaxially with the crankshaft, a first motor whose output shaft is connected to the crankshaft, a guide rod shaft (9) passing through the second through hole, a guide rod (8) fixedly installed on the guide rod shaft and rotating around the axis of the guide rod shaft, and a connecting member (7) rotatably installed on the crank wheel and used for sliding connection with the guide rod. The crank wheel (5) and the guide rod (8) are both on the same side of the experimental platform. The rotation axis of the connecting member (7) is parallel to the plane of the axis of the crank wheel (5); A first chute (11) whose axis passes through the center of the crank wheel is provided on the crank wheel (5). A first slider (6) is installed in the first chute (11). A fixing bolt is provided on the first slider (6). The connecting member (7) is rotatably connected to the first slider. A first scale for marking the distance between the rotation axis of the connecting member and the axis of the crank wheel is provided on the crank wheel; The device also includes a data acquisition structure (2). The data acquisition structure includes a linkage swing rod (12) fixedly installed on the guide rod shaft and rotating around the axis of the guide rod shaft, a main swing rod (13) and a sub-swing rod (14) respectively rotatably connected to the guide rod shaft (9). A microswitch (15) is installed on the main swing rod and / or the sub-swing rod. The guide rod is parallel to the plane of the linkage swing rod (12).

2. The quick-return characteristic verification experimental device of a crank-slider mechanism according to claim 1, characterized in that The data acquisition structure also includes a second slider (16) and a second chute (17) that cooperate with each other, a first connecting rod (18) and a second connecting rod (19) respectively rotatably connected to the second slider (16) to form a linkage mechanism. The second chute (17) is fixedly installed on the experimental platform (10) and the center line of the second chute passes through the axis of the guide rod shaft (9). The first connecting rod is rotatably connected to the main swing rod. The second connecting rod is rotatably connected to the sub-swing rod. The main swing rod, the first connecting rod, the second connecting rod, and the sub-swing rod form a planar four-bar mechanism. The first connecting rod and the second connecting rod are of equal length.

3. The quick-return characteristic verification experimental device of a crank-slider mechanism according to claim 2, characterized in that, The data acquisition structure also includes a cam (20) rotatably connected to the experimental platform (10) and an elastic member (21) for making the main swing rod contact the cam. The cam is used to adjust the included angle between the main swing rod and the sub-swing rod.

4. An experimental device for verifying the quick-return characteristic of a crank-slider mechanism according to claim 3, characterized in that, A second scale is provided on the cam. The second scale corresponds to the first scale one by one.

5. The quick-return characteristic verification experimental device of a crank-slider mechanism according to claim 4, characterized in that, The rotation center line of the cam is located on the plane formed by the axis of the crankshaft and the axis of the guide rod shaft.

6. The quick-return characteristic verification experimental device of a crank-slider mechanism according to claim 1, characterized in that, The paper tape dotting mechanism includes a base (22), a second motor (23) installed on the base, a dotting pen core (25) driven by a telescopic structure (24), a first shaft (26), a second shaft (27), a clamping shaft (28), and a paper roll shaft (29) that are arranged in parallel on the base, and a paper roll (30) sleeved on the paper roll shaft. The second motor is used to provide a turning force for the first shaft and the second shaft. The telescopic structure is electrically connected to the microswitch. The clamping shaft and the first shaft are used to clamp the paper tape (31). The first shaft and the second shaft rotate synchronously to draw out the paper tape in the paper roll. The dotting pen core is used to dot on the paper tape.

7. An experimental device for verifying the quick-return characteristic of a crank-slider mechanism according to claim 6, characterized in that The paper tape dotting mechanism further includes an axial spacing adjuster (32), and the axial spacing adjuster is used to adjust the axial spacing between the clamping shaft and the first shaft.

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