RU2239871C1 - Training device for developing construction skills during professional engineering - Google Patents

Abstract

FIELD: training devices engineering.

SUBSTANCE: device has body and cover. Body has researched parts, control and measuring devices and support means for performing measurements. A set of studied parts includes shaft, gear wheel and inserts of sliding bearing. A set of control and measurement tools includes clock type indicator, micrometer, slide gage, probes and end measure. Support means for performing measurements are a mounting bracket made in form of portion of reducer body and mandrel for gear wheel. For fixing of indicator a support is used which is mounted in one of bracket walls. Device also has internal calipers and a set of samples of surfaces roughness. In walls of bracket also provided are sockets for mounting inserts of sliding bearings and sockets for mounting pins of shaft. In base of bracket an aperture is made for mounting mandrel for gear wheel.

EFFECT: broader functional capabilities.

5 cl, 10 dwg

Description

The invention relates to teaching aids and can be used as a training installation intended for the development of design skills during detailed design, in particular for teaching critically-based selection of geometric parameters of parts, competent and meaningful design of working documentation. The invention can be used at the stage of general technical preparation of students during laboratory work in the courses “Fundamentals of Design”, “Applied Mechanics”, “Technical Mechanics”.

A device for training is known, intended to instill professional skills in assembling and disassembling parts connected with an interference fit, and comprising a housing, removable parts, means for fixing the removable parts, and control sensors. When using the device, the student assembles or disassembles the parts in accordance with the skills he has acquired. The correctness of the assembly or disassembly is monitored using control sensors that supply the appropriate signals to the teacher's remote control (see patent RU No. 2008724, CL G 09 B 25/00, 1994).

A device is known for instilling practical skills in analyzing the functional purpose and compatibility of parts according to their geometric shape. The device contains removable parts and is made in the form of one unit, including four functional groups of elements simulating various types of parts connections used in the construction of real units and machinery mechanisms, and an unambiguous sequence of disassembly and assembly of the unit is provided. There is also a device for monitoring the actions of the student in the form of a combination of hardware and software (see patent RU No. 2196360, class G 09 B 25/00, 1994).

The nature of training when using known devices is limited to instilling skills in assembling mechanisms nodes from individual parts or in disassembling them. Moreover, the known devices do not allow teaching methods for determining the geometric parameters of the product and methods for determining the degree of roughness of the surfaces of the parts of the product, and also do not provide the opportunity to familiarize themselves with the principles of basing, with the means and methods of measuring and controlling the parameters of engineering parts and their subsequent use in practice.

The technical result that is achieved by using the claimed invention is to expand the functionality of the training installation due to the possibility of using it not only to instill assembly skills of individual machine-building units (one of the machine-building units), but also to teach methods for determining the geometric parameters of the product and methods for determining the degree of surface roughness of the parts of the product, as well as to ensure the possibility of familiarization with the principles of basing, with environments Tvam and methods for measuring and monitoring the parameters of machine parts and their subsequent use in practice.

To achieve the specified technical result, a training installation is proposed for developing design skills during detailed design, which contains a housing formed by the rear, front, side walls and bottom, and a cover, the inner surface of which is filled with an elastic element, while a panel with rectangular, round ones is located inside the housing and curly stepped lodgements and recesses, the depth of which is made different and in which the set of the studied parts is placed, including the roller, gear ring with and bearings of a sliding bearing, a set of control and measuring tools, including a dial gauge, micrometer, vernier calipers, probes and an end gauge, support devices for measuring, including an installation bracket and a mandrel for a gear wheel, and a tripod for securing the indicator, including a vertical column , a horizontal bracket and a clamp connecting them movably to each other, and also contains a caliper and a set of surface roughness samples.

The mounting bracket is made in the form of a part of the gear housing and is formed by a horizontal base and two opposing vertical walls, while in the upper part of each vertical wall of the bracket there are two slots open from the upper ends of the vertical walls, one of which has the shape of a half cylinder, and the other - prismatic form.

The mounting bracket also has a socket for mounting a vertical tripod column in it, and a hole is made in the horizontal base of the bracket for mounting a mandrel for a gear in it. Opposite semicylindrical sockets are made with the possibility of installing liner bearings in the assembly with a roller installed in the liners, and opposing prismatic nests are made with the possibility of installing journal pins in them.

The socket for mounting the vertical column of the tripod can be made in the upper part of the vertical wall of the mounting bracket.

The jack for mounting the vertical column of the tripod and the lower end of the vertical column of the tripod may be threaded.

The nutrometer is located in a separate housing with a lid.

A set of surface roughness samples is located in a separate housing with a lid.

The housing and the cover are pivotally connected and provided with locking elements made in the form of a movably mounted staple and a pin hook.

The use of supporting devices in the proposed educational installation, including the mounting bracket and the mandrel for the gear wheel, in conjunction with a set of control and measuring tools (dial gauge, micrometer, caliper, probes and end gauge, as well as a caliper and a set of surface roughness samples) and a tripod to fix the indicator allows you to provide training in methods for determining the geometric parameters of the product and methods for determining the degree of surface roughness of the product, as well as providing It makes it possible to familiarize oneself with the means and methods of measuring and controlling the parameters of machine-building parts and their subsequent use in practice. The implementation of the mounting bracket in the form of a design that simulates a part of the gearbox housing and having slots for fitting parts that are gearbox elements (roller, gear wheel and plain bearing shells), not only provides optimal conditions for measuring the parameters of the parts, but also allows students to become familiar with design features of the gearbox and with the features of its assembly.

The invention is illustrated by drawings, where:

figure 1 shows a General view of the inventive installation;

figure 2 shows a mounting bracket simulating a model of a gear unit assembly and an assembly unit placed therein, including a roller, a gear wheel and bearings of loose bearings, a side view, in a section;

figure 3 is a mounting bracket with mounting nests, side view, in section;

figure 4 - tripod in the assembled state;

figure 5 - installation bracket with located in it a mandrel for the gear;

figure 6 - caliper, located in a separate housing with a lid, General view;

Fig.7 is a set of samples of surface roughness located in a separate housing with a cover, General view;

on Fig and 9 is a diagram showing the principle of measuring radial runout of the shaft;

figure 10 is a diagram showing the principle of measuring the mechanical runout of a gear wheel.

The training installation for the development of design skills during detailed design includes a housing 1 formed by a back wall 2, a front wall 3, side walls 4 and a bottom 5, and a cover 6.

In case 1 there is a set of studied parts, a set of control and measuring tools and supporting devices for making measurements.

A set of studied parts includes a roller 7, a gear wheel 8 and bearings of a sliding bearing 9.

The set of control and measuring instruments located in the said case includes a dial indicator 10, a micrometer 11, a caliper 12, probes 13 and an end gauge 14.

Supporting devices for measurements include a mounting bracket 15 and a mandrel 16 for the gear 8. To fix the indicator 10, a tripod 17 is used, including a vertical column 18, a horizontal bracket 19 and a clamp 20 connecting the column 18 and the bracket 19 movably between each other.

The installation also contains a caliper 21 located in a separate housing 22 with a cover 23, and a set of samples 24 of the surface roughness located in a separate housing 25 with a cover 26.

The mounting bracket 15 is made in the form of a part of the gear housing and is formed by a horizontal base 27 and two opposite vertical walls 28. In the upper part of each vertical wall 28 of the bracket 15 there are two slots open from the upper ends 29 of the vertical walls 28. The sockets 30 have the shape of a half cylinder and slots 31 have a prismatic shape.

In the upper part of one of the vertical walls 28 of the mounting bracket 15 there is a socket 32 for installing a vertical column 18 of the tripod 17 in it. In the horizontal base 27 of the bracket 15 there is a hole 33 for installing the mandrel 16 for the gear wheel 8. The lower end 34 of the vertical the column 18 of the tripod 17 has a thread, and in the socket 32 for mounting the vertical column 18 of the tripod 17, a mating thread is made.

Opposite semicylindrical sockets 30 are made with the possibility of installing liners 9 of slide bearings in the assembly with a roller 7 installed in the inserts 9. Opposing sockets 31 of a prismatic shape are made with the possibility of installing pins 35 of roller 7 in them to control the radial runout of the latter .

The internal cavity of the lid is filled with an elastic element 36, which provides tight locking of the various parts located in the recesses and lodgements.

The housing 1 and the cover 6 are interconnected by hinges 37 on the rear side of the housing, and on the front side of the housing and the cover there is a locking lock 38 made in the form of a movable (rotating) mounted bracket 39, for example, on the housing and a pin hook, respectively, on the cover 6.

The training installation allows, in particular, the following laboratory work.

1. Conducting laboratory work to study tolerances and landings.

The aim of the work is to familiarize with the accuracy of manufacturing parts, tolerance fields, familiarity with the tool and method of size control, familiarity with the concept of shelf life of parts. According to the drawing (figure 2) and the full-scale parts from the training installation, the student gets acquainted with the design of the conditional model of the gearbox parts, while indicating the purpose of the components that make up the assembly, types of connection parts, methods of assembly. Sketch the gear unit assembly. Put the symbol of the landing on the sketch. For the selected landing, numerical deviations are established using reference material. Build a scheme of tolerance fields. An analysis of the landing is carried out (indicate type, accuracy class, system), limit characteristics are calculated (diameters, clearances / tightness), tolerances. Indicate the purpose of the landing, the possible technology for processing mating surfaces in order to obtain the required accuracy. They control the size of the diameters of the mating surfaces of the parts. At the same time, a measuring instrument is selected, its characteristic is given, and metrological indicators are recorded (division price, measurement range, permissible measurement error, etc.). Choose a measurement method: a direct assessment method or a comparison method. With the direct assessment method, the value of the measured value is determined by the indication of the measuring instrument. In the comparison method, the measured value is compared with the measure, and the measuring tool shows the difference between the measured value and the measure. Next, the systematic error of the instrument and the measurement error are determined. The average actual size of the diameter of the seating surface of the roller 7 is determined with a micrometer 11. The average actual size of the diameter of the size of the gear wheel 8 and / or the liner 9 is determined with a nutrometer. The position of the found average actual sizes is indicated on the diagram of the tolerance fields. Give a conclusion about the validity of each part and the interface as a whole.

2. Conducting laboratory work to determine deviations in the shape and location of surfaces and their normalization.

In the process of conducting laboratory work, the student gets acquainted with the types of tolerances of the shape and location of surfaces, with the types of basing, with the methods of control of certain types of tolerances, with the concept of the suitability of parts. When conducting laboratory work, the following measuring instruments are used: micrometer 11, caliper 21, dial indicator 10.

Laboratory work is carried out in several stages.

The first step is to control the deviation of the shape of the parts. During the first stage, the roundness and cylindricality of the surface of the roller 7 is controlled. At the same time, the measuring instrument — micrometer 11 is characterized, the systematic error of the instrument and the measurement error are determined, the diameter of the roller 7 is measured with a micrometer 11 at the landing site of the gear 8 (uniformly along the generatrix in three sections; in one section evenly in four positions around the circumference), the difference in readings (in relation to the value of the nominal diameter) is determined and the shape of the real is shown from the obtained values on the surface (in longitudinal and transverse sections), cylindrical or circular tolerances and the profile tolerance of the longitudinal section of the surface of the element of the roller 7 are assigned, a simplified sketch of the roller 7 is indicated with these tolerances, they give a conclusion on the suitability. During the first stage also control the conical shape of the holes of the gear 8 or the liner 9 of the sliding bearing. At the same time, they give the characteristic of the measuring instrument - caliper 21, determine the measurement error, measure the diameter of the hole at the ends in two mutually perpendicular directions with caliper 21, determine the difference in readings (with respect to the nominal diameter), depict the shape of the real surface using the obtained values, designate the cylindrical tolerance (conical) surface, depict a simplified sketch of the part indicating this tolerance, give a conclusion about the suitability.

The second stage is to control the deviation of the location of the surfaces of the parts. During the second stage (Fig. 8, 9), the radial runout of the roller 7 (the portion of the roller 7 at the landing of the gear 8) is controlled. In this case, a roller 7 with trunnions 35 is installed in the slots 31 having a prismatic shape. The tripod 17 is assembled and mounted on the vertical wall 28 of the bracket 15. Fasten the dial indicator 10 to the tripod 17 so that the probe is located vertically in the radial direction. Give the characteristic of a measuring instrument - indicator of 10 hour type. The measurement error is determined. Enter the probe indicator 10 in contact with the controlled surface of the roller 7. Set the position of the indicator 10 to work in the range with a minimum error. Record the initial readings. Turn the roller 7 and record the readings in eight positions through 45 °. Radial runout is measured as the difference of readings R _max -R _min . Build an appropriate schedule and determine the cause of the heartbeat (eccentricity or ovality). Assign deviations to a radial runout. A simplified sketch of the roller 7 is depicted indicating this tolerance. Give a conclusion about the suitability. When carrying out the second stage also control the face runout of the gear 8 (figure 10). At the same time, the mandrel 16 is installed in the hole 33 in the base 27 of the bracket 15 and the gear wheel 8 is mounted on the mandrel. A tripod 17 is assembled and mounted on the vertical wall 28 of the bracket 15 (it is necessary to ensure the clearance-free design). Fasten the indicator 10 of the watch type on a tripod 17 so that the probe is perpendicular to the end of the gear 8. The characteristic of the measuring instrument is the indicator 10 of the watch type. The measurement error is determined. Turning the gear wheel 8 in eight positions through 45 ° at a certain diameter (as directed by the teacher or by the choice of the student), measure the face runout. Assign a deviation to the end runout. A simplified sketch of a gear wheel is shown showing this tolerance. Give a conclusion about the suitability.

3. Conducting laboratory work to determine the surface roughness of parts.

The aim of the work is to familiarize ourselves with the standard for normalizing surface roughness, with methods for assessing surface roughness, to familiarize ourselves with the concept of suitability of parts according to surface roughness parameters. During the work, the standard of normalization of surface roughness is used, recommendations for assigning the values of roughness parameters, a set of samples 24 of the surface roughness and the test piece - roller 7. In the process, a sketch of the roller is used.

7. Indicate the type (form) and method of processing each surface of the roller 7 (based on previously acquired knowledge of the course of technology of materials or similar). Assign surface roughness parameters. Using the set of samples 24 roughness determine the actual values of the roughness parameters of convex cylindrical surfaces (the parameters are rounded to the values of the roughness parameters of the samples included in the set, and the average intermediate values). Give a conclusion on the compliance of the actual values of the roughness parameters with the normalized ones. Characterize the method for assessing surface roughness.

4. Conducting laboratory work on the compilation and analysis of the assembly dimensional chain.

The purpose of the work is to familiarize yourself with the methods of calculating and controlling the accuracy of linear dimensions, familiarize yourself with the concept of the suitability of parts, with the concept of “free dimensions”. When carrying out the work, measuring instruments are used: vernier caliper 12 and probe 13; the investigated site, including the roller 7 and its associated gear 8 and inserts 9; mounting bracket 15 (model of gear unit). In the process, make up the assembly linear dimensional chain of the node. Select the closing size - the axial clearance in the support and assign its limit values, select its nominal value. Give the characteristic of the measuring instrument - vernier caliper 12. Determine the systematic error of the tool and the measurement error. The nominal values of the linear dimensions included in the dimensional chain are set. Measure with a caliper 12 linear dimensions. Based on the actual sizes, nominal values are assigned. Assign deviations to linear dimensions and to closing size. The accuracy is selected based on the purpose of the site, its working conditions and requirements (set by the teacher or assigned by the student himself). Calculate the dimensional chain. The limiting values of the closing size (gap) are determined. Assemble the node and install it in the nests 31 of the prismatic shape. Probe measures the actual value of the gap (there may be no gap). Give a conclusion about the suitability (compliance of the actual value of the gap with the acceptable values). They make up a detailed dimensional chain. For roller 7 are two options for applying linear dimensions. Indicate in each of the options closing size. A dimension chain is calculated for each variant. Indicate the type of problem being solved - direct or inverse. The nominal values of linear dimensions and the necessary deviations for linear dimensions are determined, with the exception of those deviations that are established from the calculation of the assembly dimensional chain. Give a comparative description of the options for compiling dimensional chains.

Claims (5)

1. A training installation for the development of design skills in detailed design, characterized in that it comprises a housing formed by a rear, front, side walls and a bottom, and a cover, the inner surface of which is filled with an elastic element, while a panel with rectangular, round and curly stepped lodgements and recesses, the depth of which is made different and in which the set of the studied parts is located, including the roller, gear wheel and bearings of the sliding bearing, set of measuring instruments, including a dial gauge, micrometer, vernier calipers, probes and an end gauge, support devices for measuring, including a mounting bracket and a mandrel for a gear wheel, and a tripod for securing the indicator, including a vertical column, a horizontal bracket and a clamp connecting they are movable with each other, and also contains a caliper and a set of samples of surface roughness, the mounting bracket is made in the form of part of the gear housing and is formed horizontally the base and two opposite vertical walls, while in the upper part of each vertical wall of the bracket two nests are made open from the upper ends of the vertical walls, one of which has the shape of a half cylinder and the other a prismatic shape, in the upper part of one of the vertical walls the brackets have a socket for mounting the vertical column of the tripod, and in the horizontal base of the bracket there is a hole for installing a mandrel for the gear in it, with semi-cylindrical opposing each other These sockets are made with the possibility of installing liners of sliding bearings in the assembly with a roller installed in the liners, and opposing prismatic nests are made with the possibility of installing pins of the roller in them. 2. The training installation according to claim 1, characterized in that the socket for mounting the vertical column of the tripod and the lower end of the vertical column of the tripod are threaded. 3. The training installation according to claim 1, characterized in that the caliper is located in a separate housing with a lid. 4. The training installation according to claim 1, characterized in that the set of surface roughness samples is located in a separate housing with a lid. 5. The training installation according to claim 1, characterized in that the housing and the cover are pivotally connected and are equipped with locking elements made in the form of a movably mounted staple and a pin hook.

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