JP2017111778A - Corrective forming method for gear molds - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gear mold of which the cost is restrained and the production efficiency is high.SOLUTION: By a corrective forming method for gear molds to form a desired mold by correcting deformation by affecting factors, simulation is conducted by a process involving designing of a standard mold having a tooth profile of a standard mold for manufacturing such a gear to satisfy the dimensional precision of the gear, a comparative corrective step of forming a tooth profile of a deformed mold having suffered elastic deformation by the affecting factors by using the standard mold obtained at the designing step, comparing the tooth profile of the deformed mold and the tooth profile of the standard mold and obtaining a corrected tooth profile for the tooth profile of the standard mold on the basis of the result of this comparison, and a contrastive verification step of obtaining a dimensional difference between the two tooth profiles including tooth profile of the deformed mold and the corrected tooth profile and repeating the difference seeking until the dimensional difference satisfies the required dimensional precision.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a molding correction method, and more particularly to a correction molding method for a gear mold.

A gear is a commonly used driving component, and has a great influence on the performance of a machine to be driven. Therefore, the precision of a tooth mold for producing a gear having a desired dimensional accuracy is required. In many cases, using a specialized tool, a tooth mold for forming a desired standard gear is formed by cutting a desired standard gear as a processing source so as to form a tooth surface of a desired standard gear. .
There is also a processing method for directly generating a final tooth shape by a forging method. Processing by this forging method does not require the work of scraping the standard gear, and a mold is first manufactured based on the desired standard gear, and a desired gear is manufactured from the mold.

  However, a method of forming a tooth surface that satisfies a desired gear dimensional accuracy using a specialized tool has a relatively high tooth mold accuracy, but is processed by scraping the desired standard gear. The efficiency is relatively low, and the work of scraping to form the tooth surface requires a lot of labor in the manufacturing process. Furthermore, since the above-mentioned specialized tool for scraping wears as the number of man-hours used, it is necessary to repeatedly replace the specialized tool, which increases the cost and manufacturing efficiency of the gear.

  On the other hand, processing by the forging method applies pressure to the mold during the processing process, so that the mold is subjected to stress during manufacturing, and due to the influence of repulsion by the forging parts, it is elastic due to these influencing factors. The product gear that is deformed and molded using the elastically deformed mold also causes an error (dimension difference) from the standard gear, and analyzes how much the error is between the product gear and the standard gear It is necessary to do. Depending on the result of the analysis, it is necessary to remake the mold so that the error is within the allowable range that satisfies the gear dimensional accuracy, and the gear is re-manufactured by the above-described manufacturing method using the re-made mold. These operations need to be repeated until the error is within an allowable range that satisfies the gear dimensional accuracy. Such an operation for remanufacturing the mold again complicates the machining process and the mold forming process, lowers the production efficiency and increases the cost, and the remodeling of the mold causes waste of material resources.

  This invention is made | formed in view of the said problem, and it aims at providing a gear metal mold | die with high manufacturing efficiency while suppressing manufacturing cost.

In order to solve the above-described problem, the present invention includes the following steps.
In the correction molding method of the gear mold, which corrects the deformation mold elastically deformed by the influencing factor during the manufacture of the gear and molds the desired mold by correcting with the influencing factor,
A design step for performing a simulation for designing a standard mold having a standard mold for producing the gear so as to satisfy the dimensional accuracy requirement of the gear;
Using the standard mold obtained in the design step, a molding step for performing a simulation to mold a tooth mold of the deformed mold elastically deformed with the influence factor;
Comparison of comparing the tooth mold of the deformed mold and the tooth mold of the standard mold, and performing a simulation to obtain a correction tooth mold by correcting the tooth mold of the standard mold based on the result of this comparison A correction step;
A dimensional difference between both tooth dies is obtained for the deformed mold tooth mold and the correction tooth mold, and the process ends when the dimensional difference satisfies the dimensional accuracy requirement, and the dimensional accuracy requirement is satisfied. In the case where there is not, a simulation is performed in which a model tooth mold is formed by performing geometric correction on the correction tooth mold based on the dimensional difference, and the model tooth mold satisfies the dimensional accuracy requirement. And when the model tooth mold does not satisfy the requirements for the dimensional accuracy, the model tooth mold is used as a tooth mold of the standard mold, and the verification step returns to the molding step.
The comparison verification step is repeated until the dimensional accuracy requirement is satisfied.

  The present invention provides a standard mold for manufacturing a gear so as to satisfy the requirement of the dimensional accuracy of the gear in a correction method of a gear mold for forming a desired mold by correcting deformation due to an influencing factor. The standard mold having the tooth mold is designed, the tooth mold of the deformed mold elastically deformed with the influence factor is molded using the standard mold obtained in the design step, and the teeth of the deformed mold are formed. A comparison correction step of comparing the mold with the tooth mold of the standard mold and correcting the tooth mold of the standard mold based on the result of the comparison to obtain a correction tooth mold; and Since a simulation including a step of obtaining a dimensional difference between both tooth dies and a verification verification step repeated until the dimensional difference satisfies the accuracy requirement is performed on the tooth shape and the correction tooth shape, the actual gold Reduces the number of mold rework and processing Become possible to reduce the error between the component and the standard, it is possible to provide a gear mold high production efficiency can be suppressed cost.

It is a flowchart for demonstrating correction | amendment shaping | molding of the gear metal mold | die of this invention. It is drawing explaining contrast of a tooth profile outline. It is a geometric drawing explaining the tooth type before outline correction. It is a geometric drawing explaining the tooth type after outline amendment. It is drawing explaining correction | amendment of the outline of a tooth profile in a contrast verification step.

(First embodiment)
The gear mold correction molding method of the present invention will be described with reference to FIG. FIG. 1 is a flowchart for explaining correction molding of a gear mold according to the present invention. The flowchart includes a design step S11, a molding step S12, a comparison correction step S13, and a comparison verification step S14.

  In the design step S11, simulation is performed to design a standard mold having a standard mold for manufacturing the gear so as to satisfy the requirement of the dimensional accuracy of the gear. Specifically, a standard mold is designed by simulation using a computer program. In this embodiment, the standard mold is for forming a helical gear. The above-described computer program is Solidworks or Dform 3D. For example, these programs are installed on a hard disk of a computer and used. The standard mold may be one that forms a general non-spiral gear, or other than the program described above.

  In the molding step S12, for example, the above-described program is simulated by using the CPU to perform forging molding on a standard mold data by a finite element method (FEM), and molding is performed based on the simulation result. Analysis, stress analysis, and elastic deformation analysis are performed to obtain the elastically deformed tooth mold after rebound, that is, the deformed mold tooth mold (the corresponding gear mold cavity) and store it in the storage device of the computer. In this embodiment, it is a finite element method gear model STL (Standard Template Library) output by Dform 3D, the material parameter is chrome molybdenum steel (SCM415), and the number of meshes of the material of the part to be processed Is 150,000 pieces, the number of meshes of the mold is 200,000 to 300,000, the upper punch speed is 150 mm / s, the lower punch speed is 1 mm / s, and the angular speed of the lower punch is 1 192 rad / s and the coefficient of friction is 0.08.

  In the comparison and correction step S13, the data of the standard mold tooth mold designed in the design step S11 and the deformed mold tooth mold acquired in the molding step S12 are acquired from the storage device via a bus. The CPU performs these comparisons. First, in order to confirm the position in the X and Y directions after positioning on a plane, the appearances are compared, and the tooth models of the two models described above are used as a reference based on the position of the shaft hole on the front end surface. And Subsequently, in order to confirm the position in the Z direction after positioning in the axial direction, a comparison is made on a flat surface, and two tooth types are used as a reference with the flat surface in the shaft hole. . Here, the flat surface refers to a plane that is so small that obstacles such as burrs and irregularities do not obstruct the comparison between the two.

  Finally, in order to confirm the radial position of both after positioning in the direction of the rotation axis, a comparison of both tooth types is performed, and both tooth types are compared with the outer contour of each tooth type. The standard.

  In the comparison verification step S14, in order to confirm whether or not the correction tooth mold satisfies the requirement of dimensional accuracy, the tooth mold of the deformation mold and the correction tooth mold are deformed, and the geometry of the tooth surface using the CPU. When a dimensional difference is obtained by performing a morphological comparison and the requirement for dimensional accuracy is satisfied, the comparison verification step S14 is terminated and stored in the storage device of the computer as model tooth type data. . If the dimensional accuracy requirements are not met, geometric correction is performed on the correction tooth profile. The method of performing geometric correction is as follows.

  (1) A correction tooth type is set. The setting of the correction tooth type is to obtain a dimensional difference between both tooth types with respect to the tooth type and the correction tooth type of the deformed mold, and this dimensional difference is stored in the storage device of the computer. Referring to FIG. 2, the dimensional difference includes a gear pitch difference and a tooth surface dimensional difference. The objects collected by the DEFORM3D simulation are output as an STL (Standard Triangulated Language) file, and a virtual measurement of the geometric error of the tooth surface is performed again. The STL tooth surface is measured by the P40 gear dedicated measuring machine of Klingelnberg in Germany, which is a virtual measurement comparison. The P40 measurement analysis consists of two parts, the gear pitch difference and the tooth surface dimension. Including the difference measurement, the gear measurement at P40 first defines the position of the geometric point of the standard tooth profile E in FIG. 2 and the unit vector at each geometric point. First, the position of the geometric point of the tooth surface A of the correction tooth shape and the unit vector B of each geometric point are swung at an angle ΔTa with respect to the gear axis C at the beginning of the measurement, The middle point D in the set of various points is pasted to the reference point F of the standard tooth surface E (for this reason, the middle point D and the reference point F in FIG. F6 of 3 indicates zero.) Using this swivel angle, ie the basis for calculating the pitch error, the measurement of the tooth surface error is the shape between the tooth surfaces for each defined geometric point. The error is measured and calculated using the CPU. In the present example, the largest tooth type error value obtained is 0.037 mm (36.9746 in A1 below the front end of the tooth surface in FIG. 3 (the unit in FIG. 3 is μm). It is about 0.037.).

  (2) There are two necessary limiting conditions when performing geometric correction. First, the contour of the gear end surface is held so as to coincide with the axial direction, and secondly, the contour of the end surface is This is a standard tooth profile with a gradually expanding line, so that the corrected gear mold is still a regular cylindrical helical internal gear (internal gear).

  (3) Based on the restrictive condition in (2) described above, the correction target tooth shape is returned to the curved surface by the least square method, and its error function is the sum of squares of the shortest distance between the sample point and the recursive function, Then, an optimized coefficient close to the correction target tooth shape is calculated. In this embodiment, since the gear to be generated is a helical internal gear, the optimized coefficients are the pressure angle, the movement coefficient, and the spiral angle. When the gear to be produced is not a general spiral gear, the optimization coefficient is Pressure angle, and transfer coefficient. 2, 3, and 4, FIG. 3 shows error values at each point of the tooth surface A of the modified mold, and FIG. 4 shows error values at each point of the tooth surface G of the correction mold. The numerical values in FIGS. 3 and 4 represent how far away from the standard value, and minus (−) means lower than the standard value.

  In the present embodiment, the first contour correction is to change the pressure angle 20 degrees to 19.9029 degrees, and the equivalent movement coefficient 0.41869 is changed to 0.475069. The correction tooth surface G is obtained by correcting the spiral angle 20 degrees to 20.06456 degrees so as to turn to the left, and comparing FIG. 3 and FIG. 4, the tooth surface G of the correction tooth mold is the tooth of the deformed mold. It can be seen that it is closer to the standard tooth surface E than the surface A.

  For example, A1 which is the maximum error described above is 36.9746, but A1 in the tooth surface G of the correction tooth mold of FIG. 4 is −15.3668, and the absolute value is close to the standard tooth surface E (that is, It can be seen that the error is small. On the other hand, K11 on the lower side of the rear end of the tooth surface in FIG. 3 is 2.54546, and K11 in the tooth surface G of the correction tooth mold in FIG. 4 is 14.353, so that partly from the standard tooth surface E. Although there are some that are far apart (that is, the error becomes larger), when compared with FIG. 3 and FIG. 4 as a whole, the maximum error and the average error in FIG. It can be seen that it is close to the tooth profile.

  (4) Adjust design parameters other than optimization factors such as modulus, number of teeth, width of tooth surface, diameter of root circle (dedendum circle, root circle), etc., and adjust pressure angle, movement coefficient, and spiral angle. Thus, the correction tooth pattern is brought close to the correction target tooth pattern. The peak value is calculated based on the corrected least square method, the error function is regarded as a function of the three of the pressure angle, the transfer coefficient, and the spiral angle, and the partial differentiation of these three parameters for obtaining the answer is a peak of all zero. The answer is that the error function can achieve the minimum combination of optimization factors.

  (5) Referring to FIG. 1 and FIG. 5, based on the corrected value, the CPU 21 reversely corrects the standard gear contour parameter 21 on the curved contour 22 of the gear mold tooth profile to correspond to it. After the fitting, the corrected tooth profile curve 23 is acquired and stored in the storage device. Here, since the corrected tooth profile curve 23 contracts, it finally becomes a value close to the contour parameter 21 of the standard gear. In FIG. 5, based on the simulation results, the corrected tooth profile curve 23 is formed larger than the desired mold contour parameter 21 on the assumption that the corrected tooth profile curve 23 is contracted in advance. ing. On the other hand, when it is predicted that the corrected tooth profile curve 23 is expanded in advance based on the simulation result, the corrected tooth profile curve 23 should be smaller than the desired contour parameter 21 of the mold. is necessary.

  For example, the CPU verifies the geometrically corrected model tooth shape so as to determine whether or not the dimensional accuracy requirement is satisfied. If the dimensional accuracy requirement is satisfied, the comparison verification step S14 is performed. And the geometrically corrected tooth profile is stored in the storage device as a model tooth profile. If the dimensional accuracy requirement is not satisfied, the geometrically corrected model tooth mold is replaced with a standard mold tooth shape, and from the molding step S12 to the comparison verification step until the dimensional accuracy requirement is satisfied. S14 is repeated a plurality of times.

  In this embodiment, the accuracy of the dimension is required to be less than 0.02 mm in accuracy, and through the above steps, molding and processing are performed without much time and cost. Thus, it is possible to obtain a helical gear mold that is superior to that required by the above-mentioned method, to suppress the waste of materials and to reduce the cost, and to obtain an excellent effect that the precision of the product is high.

  As described above, since the molding correction method can be performed by programming each simulation, for example, and executing the simulation by a computer, for example, before acquiring data of a desired mold that satisfies the requirements of dimensional accuracy. This eliminates the need to forge a large number of standard molds and forge the parts to be processed multiple times, simplify the preparation process for producing standard molds, increase production efficiency, Since the consumption can be reduced, the object of the present invention can be reliably achieved.

  The above is only an example of the present invention, and the scope of the present invention is not limited to this, and what can be easily modified based on the specification and claims of the present invention is not limited to this. Are included in an equivalent range and belong to the technical scope of the present invention.

S11 Design step S12 Molding step S13 Comparison correction step S14 Comparison verification step 22 Curved contour of gear mold tooth mold 23 Corrected tooth mold curve A Gear tooth surface B Unit vector C Gear axis D Middle point E Standard Tooth surface F Reference point G Correction tooth surface ΔTa Angle

Claims (8)

In the correction molding method of the gear mold, which corrects the deformation mold elastically deformed by the influential factor during the manufacture of the gear and molds the desired mold by correcting with the influential factor,
A design step for performing a simulation for designing a standard mold having a standard mold for producing the gear so as to satisfy the dimensional accuracy requirement of the gear;
Using the standard mold obtained in the design step, a molding step for performing a simulation to mold a tooth mold of the deformed mold elastically deformed with the influence factor;
Comparison of comparing the tooth mold of the deformed mold and the tooth mold of the standard mold, and performing a simulation to obtain a correction tooth mold by correcting the tooth mold of the standard mold based on the result of this comparison A correction step;
The dimensional difference between both the tooth dies is determined for the deformed mold tooth mold and the correction tooth mold, and the process ends when the dimensional difference satisfies the dimensional accuracy requirement. If not, based on the dimensional difference, a simulation is performed to form a model tooth mold by performing geometric correction on the correction tooth mold, and the model tooth mold satisfies the requirement for dimensional accuracy. And if the model tooth mold does not satisfy the dimensional accuracy requirement, the model tooth mold is used as the standard tooth mold, and a comparison verification step returns to the molding step.
The correction verification method for a gear mold, wherein the comparison verification step is repeated until the requirement for the dimensional accuracy is satisfied.   In the comparison verification step, when geometric correction is performed, a correction target tooth shape is set based on a dimensional difference between the tooth shape of the standard die and the tooth shape of the deformed die, and the correction target tooth shape The coefficient optimized by the least square method is acquired based on the above, the contour of the corrected geometric tooth shape is formed, and the geometrically corrected model tooth shape is acquired through correction correction. The correction molding method for a gear mold according to claim 1.   In the contrast verification step, the standard mold is suitable for generating a non-spiral gear, the optimized coefficient is a pressure angle and a movement coefficient, and the pressure angle and the movement coefficient are adjusted. 3. The gear mold correction molding method according to claim 2, wherein the geometrically corrected model tooth mold is brought close to the correction target tooth mold.   In the comparison verification step, the standard mold is suitable for generating a helical gear, and the optimized coefficients are a pressure angle, a movement coefficient, and a helix angle, and the pressure angle, the movement coefficient, 3. The gear mold correction molding method according to claim 2, wherein the geometrically corrected model tooth shape is brought closer to the correction target tooth shape by adjusting the spiral angle.   5. The gear mold correction according to claim 1, wherein in the comparison verification step, the dimensional accuracy requirement is that the vector accuracy error is 0.02 mm smaller than the precision error. Molding method.   In the comparison and correction step, each of the tooth molds is confirmed so as to confirm the positions in the X and Y directions after positioning in a plane with respect to the tooth mold of the deformed mold and the tooth mold of the standard mold. Compare the appearance with reference to the position of the shaft hole on the front end surface, and check the position in the Z direction after positioning in the axial direction with a flat surface in the shaft hole. 6. The correction method for a gear mold according to claim 1, wherein a comparison is made on a flat surface as a reference, and a contour of the tooth mold is compared.   In the molding step, the standard mold is analyzed by a finite element method, and a molding analysis, a stress analysis, and an elastic deformation analysis are performed based on the analysis result of the finite element method, and the tooth mold of the deformation mold The correction molding method for a gear mold according to any one of claims 1 to 6, wherein:   8. The gear mold according to claim 1, wherein the design step, the molding step, the comparison correction step, and the comparison verification step are all calculated and analyzed by a program. Correction molding method.

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