JP2000266164A - Method and device for assisting design of tapered taper cam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently form a model of a tapered taper cam having high precision. SOLUTION: A model of a cam is automatically produced by giving only contour shapes of respective end surfaces 110, 115 of a cam to a model forming part. The theoretical coordinates of the cam surfaces in the central positions of both end surfaces 110, 115, namely, the theoretical coordinate points 120 are found over the circumference on the basis of the designing conditions of the cam. The distribution of errors between respective theoretical coordinate points 120 and the formed model cam surface 125 are found, a straight line indicative of a theoretical cam surface to be found from the designing conditions is added as the restraint conditions of the model in relation to the position in which the error is maximum, and the model is again formed by the model forming part so as to satisfy the conditions. Addition of the restraint conditions and reformation of the model are repeated until the errors fall into an allowable value or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gradually changing tapered cam having a cam surface inclined with respect to the axial direction of a camshaft.
The present invention relates to a design support method and apparatus for designing using D (Computer Aided Design) technology.

[0002]

2. Description of the Related Art In order to improve engine output and fuel efficiency, the possibility of dynamically controlling the valve lift has been studied.
As such a method of controlling the valve lift, there is known a method of using a gradually changing tapered cam whose cam surface is inclined with respect to the axial direction of the camshaft (for example, Japanese Patent Application Laid-Open No. 10-30413 by the present applicant). FIG. 9 shows an overview of the gradually changing tapered cam 100. 9A is a front view, and FIG. 9B is a side view. As shown in FIG. 9, in the gradually changing tapered cam 100, a part of the cam surface 105 between the two end surfaces 110 and 115 is inclined with respect to the axial direction of the cam shaft. Due to such a cam shape, as shown in the above publication, by displacing the gradually changing tapered cam 100 in the axial direction of the camshaft, the contact portion between the cam surface 105 and the mating member (such as a shim) becomes Change in direction,
Thereby, the valve lift amount can be changed.

When trying to design a gradually changing tapered cam,
The shape of the cam end faces is an important factor, but alone is often insufficient to achieve the desired cam characteristics.
Although the cam characteristics depend on the shape of the cam surface, in the case of a gradually changing tapered cam, the shape of the cam surface is generally defined as a set of straight lines connecting corresponding points on both end surfaces of the cam. In this case, the corresponding points on both end surfaces of the cam are points where the cam surface and the mating member come into contact at the positions of the end surfaces at the same cam rotation angle. For example, in FIG.
It is assumed that the point of contact between the cam surface 105 and the mating member surface 150 at a certain cam rotation angle α is point A when the mating member surface 150 is brought into contact with the position 10. Then, when the cam is displaced in the axial direction so as to come into contact with the mating member at the position of the end surface 115, the cam surface 1 at the same cam rotation angle α
It is assumed that the point of contact between 05 and the mating member is point B. In this case, the straight line AB is a straight line that defines the cam surface shape at the cam rotation angle α. This straight line is referred to herein as a theoretical correspondence line. Theoretically, the cam surface of the gradually changing tapered cam is defined by defining this theoretical correspondence line over the entire circumference of the cam. As can be seen from the above description, in the gradually changing taper cam, the contact point at one end face 110 and the contact point at the other end face 115 are determined independently of the contact points of the two end faces at the same cam rotation angle with the mating member. When the point B is projected on a plane perpendicular to the camshaft axis direction, the declinations θ _A and θ _B from a certain reference direction do not always match.

[0004] In the development of cams, it is common to create models by CAD at each stage of product examination and mold design. Further, the created CAD model is also applied to a CAM (computer-assisted manufacturing) system to be useful for mold manufacturing and the like.

When a model of a gradually changing taper cam is generated by a CAD system, the basis is the contour shape of both end faces of the cam. However, the shape of the gradually changing tapered cam is complicated as described above, and a model that satisfies desired cam characteristics cannot be generally obtained only by designating the shape of both end faces. That is, if the CAD system automatically generates a model by designating only the contour shape of both end surfaces, the CAD system automatically generates a corresponding point between both end surfaces when generating the cam surface. Even if the automatically generated corresponding points are connected to each other, they do not always coincide with the above-described theoretical correspondence lines that theoretically define the cam surface, and thus, generally, desired cam characteristics cannot be obtained.

In view of this point, conventionally, an approach has been taken in which a CAD system is given in advance in addition to the contour shapes of both end faces, on the condition of the above-mentioned theoretically corresponding line that theoretically defines the cam surface. In this case, the CAD system arranges the cam surfaces so as to satisfy the given theoretical correspondence line.

[0007]

In this conventional approach, it is necessary to specify theoretical correspondence lines as closely as possible in order to improve accuracy. For example, conventionally, a CAD model is generated by designating a theoretical correspondence line every 1 °, and if the model does not satisfy the required accuracy, the theoretical correspondence line is set to 0.
Measures were taken such as recreating the model by specifying every 5 °. In such an approach, in order to achieve high accuracy, the number of theoretical correspondence lines to be specified may be enormous.

However, since the theoretical correspondence line becomes a constraint condition when the CAD system generates the cam surface, if the theoretical correspondence line is too dense, the load on the system becomes enormous, and the processing speed decreases significantly. In some cases, processing may not be possible. Also, if the CAD
Even if the system has a processing capability capable of coping with such a dense theoretical correspondence line, if the created model cannot be used in a CAM system, a machine tool, or the like, the meaning of using CAD is reduced by half. In consideration of application to a machine tool or the like, the smaller the data amount of the model, the better.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to provide a design support method and apparatus for generating a highly accurate gradually changing tapered cam model with as few constraints as possible. .

[0010]

In order to achieve the above object, a gradual change taper cam design support method according to the present invention comprises an initial model forming step for forming a gradual change taper cam model in accordance with an input contour shape of both end faces of the cam. A theoretical coordinate point calculating step of calculating a theoretical coordinate point of the cam surface at a predetermined position between the both end surfaces based on design conditions, and calculating an error between the calculated theoretical coordinate point and the cam surface of the model. In the case where there is a theoretical coordinate point in which an error between the error calculation step and the cam surface of the model exceeds an allowable value, the model is modified so that the theoretical coordinate point satisfies the cam surface regulation condition derived from the design condition. The model correction step until the error between the coordinates of the cam surface of the model for all the theoretical coordinate points is equal to or less than the allowable value. Return and a step.

Here, the cam surface regulation condition is, for example, the above-mentioned theoretical correspondence line. In this method, it is not necessary to specify the cam surface regulation conditions only for the number that is close to the minimum necessary to suppress the error of the cam surface of the model to the allowable value or less, so that the model creation time can be reduced. . In addition, since the model created by this method does not include cam surface regulation conditions more than necessary, when this model is given to a machine tool for machining, the operation of the machine tool is faster than in the past. Become.

The gradual change taper cam design support apparatus according to the present invention includes a design condition input means for receiving design conditions including a contour shape of both end surfaces of the cam, and a theoretical coordinate of the cam surface at a predetermined position between the both end surfaces of the cam. A theoretical coordinate point calculating means for calculating a point from the design condition, and a cam surface regulation condition based on the cam surface regulation condition derived from the design condition in a design target range. Model creation means for creating a model of a gradually changing taper cam by setting a cam surface between the cam end faces based on a predetermined internal rule from a contour shape of the cam end faces for a portion not designated Error calculating means for calculating an error between the cam surface set by the model creating means and each theoretical coordinate point calculated by the theoretical coordinate calculating means; Errors were having a model creation controlling means for recreating the model applied to said model generating means cam surfaces regulatory requirements derived from the design condition for the theoretical coordinate points exceeds a predetermined allowable value.

With this configuration, a model that satisfies the desired accuracy can be created with a small number of cam surface restriction conditions.

Here, the design condition may include information on a theoretical correspondence line connecting the contact points between the cam surfaces at both end surfaces of the cam and the mating member at each cam rotation angle. If there is information on the theoretical correspondence line, a theoretical coordinate point serving as a reference for model error determination can be easily obtained. A theoretical correspondence line can be used as the cam surface regulation condition.

In a preferred aspect, the model creation control means includes:
The cam surface regulation conditions for the theoretical coordinate point at which the error is maximized are given to the model creating means to recreate the model, and the error between the theoretical coordinate point and the cam surface is calculated by the error calculating means for the recreated model. Then, these processes are repeated until all errors for each theoretical coordinate point become equal to or less than the allowable value. According to this aspect, it is possible to create a model with a desired accuracy under a minimum number of cam surface regulation conditions.

[0016]

Embodiments of the present invention (hereinafter referred to as embodiments) will be described below with reference to the drawings.

FIG. 1 is a functional block diagram showing the configuration of a gradually changing tapered cam design support apparatus according to the present invention. In FIG. 1, a design condition input unit 10 is a means for receiving input of design conditions for a cam for which a model is to be created. The input design conditions include the contour shape of both end faces of the cam and the straight line (referred to as the theoretical correspondence line) connecting the contact points between the cam surface and the mating member at the position of each end face at each cam rotation angle. Information. Each theoretical correspondence line corresponds to a straight line (straight line AB in FIG. 10) that defines the cam surface shape of the above-described gradually changing tapered cam. The information of the theoretical correspondence line can be represented by a pair of coordinates of a contact point between a cam surface at each end face of the cam and a mating member (such as a shim) at the same cam rotation angle. As a design condition, this theoretical correspondence line is defined for a plurality of cam rotation angles (for example, every 0.5 °) selected in advance. These design conditions may be input interactively, or may be obtained by reading information obtained by another computer.

The theoretical coordinate point calculation section 12 calculates theoretical coordinate points (referred to as theoretical coordinate points) of the cam surface at predetermined positions between both end surfaces of the cam. The theoretical coordinate point is a point on a theoretical cam surface that satisfies a given design condition at a predetermined position between both end surfaces of the cam, for example, a center position. For example, FIG. 2 shows a theoretical coordinate point 120 obtained for each cam rotation angle, for example, every 1 °, at an intermediate point between both end surfaces 110 and 115 over the entire circumference of the cam 100. The theoretical coordinate points are obtained by an appropriate number as necessary over the entire circumference (or a predetermined range) of the cam. If a high-accuracy model is to be generated, the theoretical coordinate points should be dense. The number (or density) of the theoretical coordinate points to be obtained is input by the user in advance.

The coordinate value of the theoretical coordinate point can be obtained from the information on the theoretical correspondence line under the design conditions. That is,
For example, if a point on the cam surface at the center position of both end faces of the cam is selected as the theoretical coordinate point, the coordinates of the theoretical coordinate point can be obtained as the midpoint of the theoretical correspondence line. Therefore,
For example, when calculating theoretical coordinate points at every 1 ° over the circumferential surface of the cam, a theoretical corresponding line is selected at every 1 ° from a set of theoretical corresponding lines given as design conditions, and for each selected theoretical corresponding line, What is necessary is just to calculate the midpoint.

The model creating section 14 calculates the C of the gradually changing taper cam.
This is an apparatus for creating an AD model, and a known CAD system can be used. When only the contour shape of both end faces of the cam is specified, the model creating unit 14 sets a temporary corresponding line between the contours of both end faces according to a predetermined internal rule, and satisfies the temporary corresponding line. Create a model as follows. For example, the contour lines of each end face are equally divided, and a line connecting the corresponding equal points is set as a temporary corresponding line. A wire frame model of the cam is constituted by both end faces and a group of temporary corresponding lines therebetween, and a surface model of the cam is formed by pasting a patch such as a flat surface or a parametric curved surface to the wire frame model. You. FIG. 3 shows an example of a provisional correspondence line 135 connecting the equally dividing points of the contours of both end faces of the cam 100.

The model creating section 14 also accepts conditions for regulating the cam surface, in addition to the contour shapes of both end surfaces. As such a cam surface restriction condition, there is a theoretical correspondence line between contact points on both end surfaces of the cam at the same cam rotation angle. For example, if one theoretical correspondence line is explicitly specified as the cam surface restriction condition, the model creating unit 14 sets the cam surface so as to pass through the theoretical correspondence line. That is, the model creation unit 14
In the design area of the cam surface, the part where the theoretical correspondence line is specified is satisfied so that the theoretical correspondence line is satisfied.
For a portion where a theoretical correspondence line is not specified, a provisional correspondence line is set according to a predetermined internal rule, and a surface model is created so as to satisfy the provisional correspondence line.

The error calculating section 16 is for calculating an error of the cam model (surface model) created by the model creating section 14 from the theoretical cam shape. In this embodiment, as shown in FIG. 2, the distance between the theoretical coordinate point 120 obtained by the theoretical coordinate point calculator 12 and the cam surface 125 of the model is used as the error. That is, the error calculating unit 16 obtains, for each theoretical coordinate point, the distance between that point and the cam surface of the model, and uses that distance as the model error for each theoretical coordinate point. According to the error calculation unit 16, FIGS.
An error distribution for each theoretical coordinate point as shown in FIG. 8 is obtained.

The model creation control unit 20 includes the model creation unit 1
4 is a control unit for controlling the control unit 4 to create a model satisfying a given design condition. Model creation control unit 20
Determines whether the model satisfies the design conditions with desired accuracy from the model error obtained by the error calculation unit 16 for the model created by the model creation unit 14, and the accuracy of the model is insufficient. In such a case, the model creation unit 14 re-creates the model by adding the cam surface restriction condition, thereby achieving higher model accuracy. For example, the model creation control unit 20
When there is a theoretical coordinate point where the model error exceeds a predetermined allowable value, a theoretical correspondence line passing through the theoretical coordinate point is given to the model creating unit 14 as the cam surface restriction condition, and the model is ordered to be recreated. However, as described as a problem of the prior art, it is preferable that the constraint condition of the model is small,
It is preferable that the number of theoretical correspondence lines added as the cam surface regulation condition is also small. One policy that responds to this request is:
Select one point from the theoretical coordinate points where the model error exceeds the allowable value, add a theoretical correspondence line only for this point, re-create the model, calculate the model error again for the resulting model, If there is a point where the model error exceeds the allowable value, it is possible to adopt a policy of repeating the same processing. The point selected from the theoretical coordinate points where the model error exceeds the allowable value is preferably a point at which the model error is maximized in view of the error suppression effect. Since the point where the error is maximum can be automatically obtained, the model creation control unit 2
0 can automatically instruct the model creation unit 14 to re-create the model. The model error is calculated after the model is recreated (that is, corrected), and the model correction is discontinued when the model error finally falls below the allowable value for all the theoretical coordinate points, and the model at that time is finalized. And As a result, a model of the gradually changing taper cam satisfying the desired accuracy can be obtained under very few constraint conditions (theoretical correspondence line). For example, the model creation control unit 20
First, only the contour information of both end faces of the cam is given to the model creating unit 14 to create a model, and thereafter, cam surface restricting conditions for suppressing errors of the created model are given to the model creating unit 14 to give the model. Is repeated.

Next, with reference to FIG. 4, an example of the procedure of the design processing in this embodiment will be described. In this example, first, design conditions such as the shapes of both end faces of the cam and a group of theoretically corresponding lines are set in the design condition input unit 10 (S10). Next, the theoretical coordinate calculation unit 12 calculates the coordinates of the theoretical coordinate point serving as a reference for the model error determination from the design conditions, particularly the information of the theoretical correspondence line (S12). The theoretical coordinate point is, for example, 0.
It is obtained for each predetermined cam rotation angle such as 5 °.

After the above processing is completed, the model creation control unit 20 starts a model creation and correction processing loop using the model creation unit 14 and the error calculation unit 16.
In this processing loop, the model creation control unit 20 first gives a condition to the model creation unit 14 and creates a cam surface model that satisfies the condition (S14). Here, the model creating unit 14 creates a surface model so as to satisfy the given condition. Model creation unit 1
Conditions given to 4 include the contour shape of both end faces of the cam and the theoretical correspondence line. For example, when only the shapes of both end faces of the cam are given to the model creating unit 14, the model creating unit 14
Generates a temporary corresponding line 135 as shown in FIG. 3 according to a predetermined rule, and creates a surface model.

After the surface model is created, the error calculator 16 calculates an error (see FIG. 2) between the cam surface of the model and each theoretical coordinate point obtained in S12 (S16).
The model creation control unit 20 checks the distribution of the error between each theoretical coordinate point obtained by the error calculation unit 16 and the model cam surface, compares the error at each point with a predetermined allowable value (S18), and determines whether the error is an allowable value. If there is a theoretical coordinate point exceeding the theoretical coordinate point, the one with the largest error is specified (S20), and the theoretical correspondence line corresponding to the theoretical coordinate point with the largest error is passed to the model creating unit 14 as an additional cam surface restriction condition. (S22), model creation unit 14
Causes the model to be re-created (S14). In this case, the model creating unit 14 arranges the given theoretical correspondence line in the wire frame model, and arranges a temporary corresponding line according to an internal rule for a part where the theoretical correspondence line is not arranged. By applying a predetermined patch (surface element) to the wire frame model, a surface model of the cam is created. As a result, as shown in FIG. 5, a model in which the theoretical correspondence line 130 is partially set is created. The model shown in FIG. 5 differs from the model shown in FIG. 3 in that a theoretical correspondence line 130 is set in the range indicated by A instead of the provisional correspondence line 135. A model error is calculated again for the model re-created in this way (S16), and it is determined whether the error satisfies an allowable value (S18).

The processing loop from S14 to S22 is repeated, and if it is determined in S18 that the errors for all the theoretical coordinate points are equal to or less than the allowable value, the process exits the processing loop and the model creation control unit 20 returns to the current state. Output the model as a design result.

In the case of fully automatic design, in the first processing loop of model creation / correction, a model is created using only the contour shape of the cam end faces as model constraint conditions, and thereafter, while the model error exceeds an allowable value. Can automatically obtain a model that satisfies the desired accuracy by repeating the model correction by adding one line at a time corresponding to a theoretical coordinate point corresponding to the theoretical coordinate point at which the error becomes the maximum as a constraint condition.

FIGS. 6 to 8 show changes in the distribution of model errors in the process of model creation / correction when a certain gradually changing tapered cam is designed. FIG. 6 shows an error distribution in a case where a model is created only with the contour shapes of both end faces without setting a theoretical correspondence line. Here, for example, the allowable value of the error is set to 0.
01. From this error distribution, it can be seen that the error exceeds the allowable value, and the position where the cam rotation angle is 59 ° is the position where the error is the largest. Therefore, the model creation control unit 20 adds the theoretical correspondence line for the cam rotation angle 59 ° as the cam surface restriction condition, and causes the model creation unit 14 to re-create the model. FIG. 7 shows the error distribution of the model obtained as a result. From this error distribution, it can be seen that even the re-created model does not satisfy the allowable value of the error.
Therefore, the position of the maximum error is obtained again, and the model is recreated by adding the theoretical correspondence line corresponding to the position to the condition. By repeating such a processing loop, finally,
As shown in FIG. 8, a model in which the model error is equal to or less than the allowable value over all cam rotation angles is obtained.

The preferred embodiment of the present invention has been described above. As described above, according to the present embodiment, a model that satisfies the target accuracy can be obtained by setting very few theoretical correspondence lines. In particular, in a method in which the theoretical correspondence lines are sequentially added to the position of the maximum model error to suppress the errors, it can be said that the number of theoretical correspondence lines used to satisfy the target accuracy is close to the minimum. As described above, according to the present embodiment, since the theoretical correspondence line is arranged only at the position necessary to satisfy the accuracy, the cam shape can be defined with much less restrictive conditions than in the past, and the model Data volume is reduced. As a result, it is possible to reduce the model creation speed and the machining time in a machine tool using the created model. In a test performed by the inventor, the time required for creating a model was reduced by about 30% and the time required for processing using a model was reduced by about 10%, as compared with the conventional method.

In the above-described embodiment, the theoretical coordinate point used as a reference for error determination is selected at the center position of both end faces of the cam. However, a point at a position other than the center position may be selected as the theoretical coordinate point. However, from the viewpoint of the effect, it is preferable to select the point at the center position.

It is also possible to specify a theoretical coordinate point not only at the center position of both end faces but also at other positions. That is, a plurality of points on one theoretical correspondence line are designated as theoretical coordinate points. According to this method, the processing time becomes longer, but the accuracy of the model can be further improved.

In the above embodiment, the model is automatically corrected under the control of the model creation control unit 20. For example, the error distribution obtained by the error calculation unit 16 is displayed on a screen, and the user sees the error distribution and performs theoretical correspondence. It is also possible to adopt a configuration in which a position to which a line is to be added is specified, and the model creation control unit 20 adds a theoretically corresponding line at that position as a condition of the model.

Further, if a plurality of theoretical correspondence lines are added in one model correction, the number of model corrections can be reduced. However, in this case, the number of theoretical correspondence lines included in the finally obtained model is likely to be larger than in the example of the above embodiment.

In the above example, the first model is determined based only on the contour shape of both end faces of the cam, but at the first time, the user specifies one or more important theoretical correspondence lines in the cam shape. Is also conceivable. By doing so, an accurate model can be obtained more quickly.

In the above example, the theoretical correspondence line defining the cam surface is a straight line. However, if a gradually changing tapered cam having a more complicated profile is assumed, the theoretical correspondence line may be curved. Also in this case, if the shape information of the theoretical correspondence line is given as the design condition, the theoretical coordinate point can be obtained in the same manner as described above, so that the method of the above embodiment can be applied.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing a configuration of a gradually changing tapered cam design support device according to the present invention.

FIG. 2 is a diagram for explaining an error between a theoretical coordinate point and a cam surface of a model.

FIG. 3 is a diagram showing a model of a gradually changing tapered cam automatically generated by a model creating section on the condition of only the contour shapes of both end faces.

FIG. 4 is a flowchart illustrating a procedure of a design process according to the embodiment.

FIG. 5 is a diagram showing a model of a gradually changing taper cam generated by a model creating section under the condition of a theoretical correspondence line that regulates cam surface generation in addition to the contour shapes of both end faces.

FIG. 6 is a diagram showing an error distribution of a model created from only contour shapes of both end faces without setting a theoretical correspondence line.

7 is a diagram showing an error distribution of a model recreated by setting a theoretical correspondence line at the position of the maximum error in the error distribution of FIG. 6;

FIG. 8 Repeats the error determination and the addition of the theoretical correspondence line,
It is a figure showing the error distribution of the model finally obtained.

FIG. 9 is a view for explaining the shape of the gradually changing tapered cam.

FIG. 10 is a view for explaining a straight line that defines a cam surface of the gradually changing tapered cam.

[Explanation of symbols]

10 design condition input unit, 12 theoretical coordinate point calculation unit, 14
Model creation section, 16 error calculation section, 20 model creation control section, 100 gradually changing taper cam, 110, 115 end face, 105 cam face, 120 theoretical coordinate point, 125 cam face of model.

Claims (4)

[Claims] 1. A method for supporting a gradually changing tapered cam having a cam surface inclined with respect to the axial direction of a camshaft, wherein an initial model is created for creating a model of a gradually changing tapered cam according to an input contour shape of both end faces of the cam. A theoretical coordinate point calculating step of calculating a theoretical coordinate point of a cam surface at a predetermined position between the both end surfaces based on design conditions; and calculating an error between the calculated theoretical coordinate point and the cam surface of the model. Error calculating step, when there is a theoretical coordinate point where the error of the model from the cam surface exceeds an allowable value, the model is adjusted so that the theoretical coordinate point satisfies the cam surface restriction condition derived from the design condition. A model correcting step for correcting, and, for all of the theoretical coordinate points, the model correcting step is performed until an error between the coordinates of the cam surface of the model is equal to or less than the allowable value. Gradual change Tepakamu design support method comprising the steps of: repeating. 2. An apparatus for supporting the design of a gradually changing tapered cam having a cam surface inclined with respect to the axial direction of a camshaft, comprising: design condition input means for receiving design conditions including contour shapes of both end surfaces of the cam; A theoretical coordinate point calculating means for calculating a theoretical coordinate point of the cam surface at a predetermined position between both end surfaces of the cam from the design conditions, and a cam surface restriction condition derived from the design conditions in a design target range are provided. For a portion, a cam surface is set between the cam end surfaces based on a predetermined internal rule from a contour shape of the cam end surfaces for a portion for which no cam surface regulation condition is specified, for a portion for which the cam surface restriction condition is not specified. A model creating means for creating a model of the gradually changing tapered cam by: a cam surface set by the model creating means, and an error between each theoretical coordinate point calculated by the theoretical coordinate calculating means. Error calculating means for calculating; and a cam surface regulation condition derived from the design condition for the theoretical coordinate point at which the error calculated by the error calculating means exceeds a predetermined allowable value is given to the model creating means to re-create the model. And a model creation control means. 3. The design condition includes information on a theoretical correspondence line connecting contact points between a cam surface at both ends of the cam and a mating member at each cam rotation angle. 3. The gradually changing tapered cam design support device according to claim 2, further comprising a theoretical correspondence line in the rotation angle. 4. The model creation control means provides the model creation means with the cam surface regulation condition for the theoretical coordinate point at which the error is maximum, and recreates a model.
For the recreated model, the error calculating means calculates the error between each theoretical coordinate point and the cam surface, and repeats these processes until all the errors for each theoretical coordinate point are equal to or less than the allowable value. The gradually changing tapered cam design support device according to claim 2 or 3, wherein: