JP5253188B2 - Gear tooth surface shape measuring device and measuring method - Google Patents

Description

The present invention relates to a measuring apparatus and how the tooth surface shape of the gear, in particular, relates to the measurement of the tooth surface shape of the helical gear.

  In general, a power transmission device for a vehicle includes a transmission, and a rotational speed input to the transmission is converted into a predetermined rotational speed and output. A gear-type transmission mechanism is frequently used in this transmission, and gear noise and vibration generated by the meshing of the gears may be superimposed by air propagation or solid propagation to cause noise. It has been confirmed that the cause of such gear noise and vibration is greatly influenced by the accuracy of the gears.

  As a method for reducing gear noise and vibration, it is possible to accurately measure the tooth surface shape of a gear and manage and evaluate the tooth surface shape of each tooth based on the measurement result. Regarding the measurement of the tooth surface shape of a conventional gear, a technique for detecting an error of the tooth shape along the direction of simultaneous contact line or the direction of meshing of the tooth surface has been proposed (for example, see Patent Document 1). Further, a method for verifying a tooth profile measuring instrument that is not affected by the shape deviation of the verification master has been proposed (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 9-5209 JP 2004-101247 A

  As a gear cross-sectional shape that can correspond to the meshing performance of the gear, the cross-sectional shape in the meshing direction is raised. In order to guarantee the gear noise performance of the gear, it is necessary to measure the cross section in the meshing traveling direction of the gear with high accuracy.

  Although there is a description in Patent Document 1 that the tooth profile in the meshing direction is theoretically obtained from the detection result of the tooth profile direction and the tooth trace direction, the correction amount for the machine accuracy error using the detection result of the tooth profile direction and the tooth trace direction. There is no disclosure about seeking.

The present invention has been made in view of the above problems, the main object is to provide a measuring apparatus and how to measure the tooth surface shape along the engagement direction of travel of the gear with high precision.

A gear tooth surface shape measuring device according to one aspect of the present invention is a device that measures a tooth surface shape along a gear meshing traveling direction, a measuring unit that measures the tooth surface shape, and a measuring unit A control unit for controlling the operation. The control unit calculates the tooth surface shape by multiplying the actual measurement value of the tooth surface shape along the meshing direction measured by the measurement unit by the correction value C _comp obtained by the following equation.

Where C _CV is a correction value for a mechanical accuracy error in the tooth profile direction, C _LD is a correction value for a mechanical accuracy error in the tooth trace direction, α is an angle formed by the tooth profile direction and the meshing direction, and β is a basic cylinder of the gear. Represents the upper helix angle.

A method for measuring a tooth surface shape of a gear according to another aspect of the present invention is a method of measuring a tooth surface shape along the meshing traveling direction of the gear, and an actual measurement value of the tooth surface shape along the meshing traveling direction. A step of measuring, and a step of calculating a tooth surface shape by multiplying an actual measurement value by a correction value C _comp obtained by the following equation.

Where C _CV is a correction value for a mechanical accuracy error in the tooth profile direction, C _LD is a correction value for a mechanical accuracy error in the tooth trace direction, α is an angle formed by the tooth profile direction and the meshing direction, and β is a basic cylinder of the gear. Represents the upper helix angle.

  According to the measuring method of the present invention, the tooth surface shape along the meshing direction of each tooth of the gear can be accurately managed and evaluated, which can contribute to the improvement of the accuracy of the tooth surface shape of each tooth. Therefore, gear noise and vibration due to meshing between gears are reduced, and noise can be suppressed.

It is a perspective view which shows the measuring device of the tooth surface shape of the gear of this Embodiment. It is a block diagram for demonstrating the control system of the measuring apparatus shown in FIG. It is a 1st perspective view which expands and shows a part of helical gear by which a tooth surface shape is measured by the measuring apparatus and measuring method which concern on this Embodiment. It is a 2nd perspective view which expands and shows a part of helical gear by which a tooth surface shape is measured by the measuring apparatus and measuring method which concern on this Embodiment. It is a flowchart which shows the measuring method of the tooth surface shape of the helical gear shown in FIG. It is a schematic diagram which shows the derivation _| leading-out method of the machine difference correction value Ccomp in a meshing advance direction. It is a graph which shows typically the difference of the actual value of the shape of the tooth surface along a meshing progress direction, and the value after amendment.

  Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

  In the embodiments described below, each component is not necessarily essential for the present invention unless otherwise specified. In the following embodiments, when referring to the number, amount, etc., unless otherwise specified, the above number is an example, and the scope of the present invention is not necessarily limited to the number, amount, etc.

  FIG. 1 is a perspective view showing a gear tooth surface shape measuring device 60 of the present embodiment. As shown in FIG. 1, in this measuring device 60, a rotating shaft 30 for mounting a gear is provided on a bed 31 in a vertical direction, and a pin 32 that supports the other shaft end of the gear rotates. It is disposed above the shaft 30 so as to face the rotating shaft 30.

  Further, a column 33 is disposed on the bed 31 so as to be able to reciprocate in a direction (X direction) approaching and separating from the rotation shaft 30. A Z-axis head 34 that reciprocates in the direction parallel to the central axis of the rotary shaft 30, that is, the vertical direction (Z direction) is attached to the front surface of the column 33 on the rotary shaft 30 side. Further, a Y-axis head 35 that reciprocates in the left-right direction (Y direction) with respect to the rotary shaft 30 is attached to the front surface of the Z-axis head 34. A stylus 36 is attached to the front surface of the Y-axis head 35 on the rotating shaft 30 side via a detector 37 that detects the displacement. The stylus 36 measures the tooth surface shape while being in contact with the tooth surface of the gear.

  The rotary shaft 30 and the column 33 and the heads 34 and 35 of each axis are rotated and driven by numerical control (NC). FIG. 2 is a block diagram for explaining a control system of the measuring apparatus 60 shown in FIG. As shown in FIG. 2, the servo motor 38 that drives the rotary shaft 30 is controlled by a rotation controller 39. A rotary encoder 40 that detects the rotation amount of the servo motor 38 is connected to input a feedback signal to the rotation controller 39.

  A servo motor 41 that drives the Y-axis head 35 in the left-right direction is controlled by a Y-axis controller 42. A linear encoder 43 that detects the amount of movement of the Y-axis head 35 in the X direction is connected to input a feedback signal to the Y-axis controller 42.

  A servo motor 44 that linearly moves the Z-axis head 34 in the vertical direction is controlled by a Z-axis controller 45. A linear encoder 46 that detects the amount of movement of the Z-axis head 34 is connected to input a feedback signal to the Z-axis controller 45.

  A servo motor 47 that linearly reciprocates the column 33 is controlled by an X-axis controller 48. A linear encoder 49 that detects the amount of movement of the column 33 is connected to input a feedback signal to the X-axis controller 48.

  A controller 50 that outputs control signals to these controllers 39, 42, 45, 48 is provided. The control unit 50 is connected to the detector 37 and is connected to an output device 51 that outputs control contents or detection results. The control unit 50 controls the operation of the stylus 36 via the controllers 39, 42, 45, 48. The feedback signals of the rotary encoder 40 and the linear encoders 43, 46, 49 are also taken into the control unit 50 to create a control command and use it for error calculation. The rotation direction of the rotary shaft 30 and the moving direction of the stylus 36 are set as indicated by the symbols + and − in FIG. The measuring device 60 is configured so that the stylus 36 as a measuring unit that measures the tooth surface shape of the gear can move simultaneously in the X, Y, and Z axis directions.

  3 and 4 are enlarged perspective views showing a part of a helical gear whose tooth surface shape is measured by the measuring apparatus and measuring method according to the present embodiment. In the figure, a single tooth 10 of a helically helical gear 1 is shown. As shown in FIGS. 3 and 4, the helical gear 1 includes a tooth tip surface 11 formed on the tooth tip 14 side of the tooth 10, and a tooth formed so as to connect the tooth tip 14 and the tooth base 15. Surface 12. The tooth surface 12 is surrounded by edges 18 and 19 extending in the tooth profile direction indicated by the arrow 4 and edges 16 and 17 extending in the tooth trace direction indicated by the arrow 6 on the tooth tip 14 side and the tooth root 15 side, respectively. It is formed in a substantially rectangular shape. The end side 18 and the end side 19 face each other in the tooth trace direction and extend in parallel to each other. The end side 16 and the end side 17 face each other in the tooth profile direction and extend in parallel to each other.

  In FIG. 4, the tooth surface 12 shows a meshing advance direction indicated by an arrow 8. An engagement occurs between the helical gear 1 and the other gear (not shown) by a predetermined contact width (referred to as a simultaneous contact line) at each moment. The meshing traveling direction indicates the direction in which the simultaneous contact line on the tooth surface 12 of the helical gear 1 moves as the helical gear 1 rotates. The meshing advance direction extends obliquely with respect to both the tooth trace direction and the tooth profile direction. The extending direction of the arrow 8 indicating the meshing traveling direction is obtained by connecting the positions where the tooth surface 12 becomes the highest on each simultaneous contact line on the tooth surface 12. The height of the tooth surface 12 indicates the distance from the design reference tooth surface of the helical gear 1, for example, the reference tooth surface of the involute tooth profile to the tooth surface 12.

  Hereinafter, a method for measuring the shape of the tooth surface 12 of the helical gear 1 according to the present embodiment will be described. FIG. 5 is a flowchart showing a method for measuring the tooth surface shape of the helical gear 1 shown in FIG. Note that the method for measuring the shape of the tooth surface 12 of the helical gear 1 according to the present embodiment is a computer-readable recording medium, such as a hard disk, in which a program for sequentially executing the steps shown in FIG. 5 is recorded. And a computer having a ROM (Read-Only Memory). Here, the “computer” refers to what constitutes the control unit 50 according to the present embodiment.

In the measurement method of the tooth surface 12 of the helical gear 1 according to the present embodiment, as shown in FIG. 5, first, in a step (S10), a correction value C _CV for the mechanical accuracy error in the tooth profile direction is determined. Specifically, using the measuring device 60 shown in FIG. 1, the tooth surface shape along the tooth profile direction of the master gear is measured, and the measured value is multiplied by the correction value C _CV to obtain the measured value of the master gear. The correction value C _CV is determined so as to be adjusted to a predetermined accuracy.

Next, in the step (S20), determines a correction value _{C LD} to mechanical precision error in the tooth trace direction. Specifically, by using a measuring device 60 shown in FIG. 1, the tooth surface shape along the tooth trace direction of the master gear is measured and the master gear and the measured value by multiplying the correction value C _LD to measured actual value The correction value C _LD is determined so as to match the predetermined accuracy.

  Next, in step (S30), the gear specifications such as the helical gear 1 module and the basic cylinder upper helix angle β are input to the computer using an input device such as a keyboard. In addition, the cylinder used as the foundation from which an involute tooth profile (tooth surface) is made is called a basic cylinder. That is, when the yarn wound around the basic cylinder is rewound in a tensioned state, the curve drawn by the tip forms the tooth profile of the involute gear. Further, the torsion angle β on the base cylinder indicates an angle at which the streak direction of the tooth 10 is inclined with respect to the axial direction of the base cylinder.

  Next, in the step (S40), the meshing traveling direction is set. Specifically, based on the information input in the step (S30), a plurality of simultaneous contact lines are set on the tooth surface 12, and a meshing advance direction is set in a direction intersecting the plurality of simultaneous contact lines. For example, the meshing traveling direction can be set using the technique described in Japanese Patent Application Laid-Open No. 11-118407.

Next, in step (S50), a correction value C _comp for the machine accuracy error in the meshing direction is determined. FIG. 6 is a schematic diagram illustrating a method for deriving the machine difference correction value C _comp in the meshing traveling direction. Fig.6 (a) shows the action surface 13 which planarly developed the tooth surface 12 of the tooth | gear 10 shown to FIG. 3 and FIG. The action surface 13 is represented by a rectangle whose four sides are constituted by the end sides 16, 17, 18, 19 of the teeth 10. FIG. 6B is a diagram showing the arrangement of the teeth 10 on the outer peripheral surface of the helical gear 1 and other teeth 20 adjacent to the teeth 10. FIG. 6B also schematically shows the movement of the stylus 36 developed in the tooth trace direction when the stylus 36 as a measuring element measures the shape of the tooth surface 12 along the meshing direction. Has been. FIG. 6C is a diagram schematically showing the movement of the stylus 36 developed in the tooth surface normal direction when the shape of the tooth surface 12 along the direction in which the stylus 36 meshes is measured.

On the working surface 13 shown in FIG. 6A, the tooth profile direction indicated by the arrow 4 and the meshing advance direction indicated by the arrow 8 intersect so as to form an angle α. In the working surface 13, the meshing direction is inclined by an angle α with respect to the tooth profile direction. The dimensions of the rectangular side edges 18 and 19 formed by the working surface 13 and extending in the tooth profile direction are indicated by ₁₀ shown in FIG. When measuring the shape of the tooth surface 12 of the tooth 10 of the helical gear 1 along the meshing advance direction, l ₀ is necessary for measuring the tooth profile direction component of the tooth surface 12 shape along the meshing travel direction. The rotation amount of the helical gear 1 is shown. In other words, in the state where the helical gear 1 is stopped, the tooth surface normal direction of the stylus 36 with respect to the helical gear 1 is required to obtain the tooth profile direction component of the tooth surface 12 shape along the meshing traveling direction. Is the dimension l ₀ .

On the other hand, when measuring the shape of the tooth surface 12 of the tooth 10 of the helical gear 1 along the meshing traveling direction, it is necessary to measure the tooth trace direction component of the shape of the tooth surface 12 along the meshing traveling direction. rotational amount of the gear 1 helical is represented by dimension _{l TA} shown in FIG. 6 (c). Since the tooth 10 is formed on the helical gear 1 to have a torsion angle β on the basic cylinder, in order to measure the tooth line direction component of the tooth surface 12 along the meshing traveling direction, the tooth line is used. It is necessary to consider not only the direction but also the movement in the tooth surface normal direction in combination. In other words, it is necessary to move the stylus 36 relative to the tooth 10 of the helical gear 1 in the tooth surface normal direction in addition to the tooth direction, so that the tooth surface 12 and the stylus 36 are synchronized. . Its stylus 36 when the relative movement amount of tooth surface normal direction to the gear 1 Helical of being stopped is the dimension l _TA.

  That is, the rotation amount of the helical gear 1 (or the tooth surface normal of the stylus 36 with respect to the helical gear 1 in a stopped state) required for measuring the shape of the tooth surface 12 along the meshing direction. The amount of movement (direction) l can be expressed by the following equation.

As described above, l _TA meshes required to measure the tooth trace direction component of the shape of the tooth surface 12 along the traveling direction, the tooth surface normal direction relative with respect to the gear 1 Helical of being stopped The amount of movement. Using the amount of movement l _AX in the tooth trace direction of the stylus 36 when measuring the tooth trace direction component of the shape of the tooth surface 12 along the meshing traveling direction shown in FIG. 6B, l _TA is as follows: It is expressed in

Here, referring to FIG. 6A, the relationship between l ₀ , l _AX and angle α is

In the end, l _TA is represented as follows using the dimension l ₀ .

Therefore, considering the contribution ratio of the stylus 36 to the tooth profile direction and the amount of movement in the tooth trace direction, it is necessary to perform correction of 1 time in the tooth profile direction and correction of tan αtan β times in the tooth trace direction. For this reason, the correction value C _comp for the mechanical accuracy error in the meshing traveling direction is expressed by the following equation.

In this way, using the correction value C _CV for the machine accuracy error in the tooth profile direction determined in step (S10) and the correction value C _LD for the machine accuracy error in the tooth trace direction determined in step (S20), C _CV And C _LD can be converted to determine a correction value C _comp for the machine accuracy error in the meshing direction.

Returning to FIG. 5, in the next step (S <b> 60), the stylus 36 is brought into contact with the tooth surface 12, and moved so as to scan the tooth surface 12 along the meshing direction, whereby the meshing direction of the teeth 10. The shape of the tooth surface 12 along the line is measured. Subsequently, in the step (S70), the shape of the tooth surface 12 along the meshing advance direction is corrected using the machine difference correction value C _comp in the meshing advance direction obtained in the step (S50). Specifically, the corrected shape of the tooth surface 12 is calculated by multiplying the measured value of the shape of the tooth surface 12 measured in the step (S60) by the correction value C _comp .

FIG. 7 is a graph schematically showing the difference between the measured value of the shape of the tooth surface 12 along the meshing direction and the corrected value. By determining the value (magnification) to be multiplied with the actual measurement value indicated by the broken line in FIG. 7 using the correction value C _comp described above, the corrected tooth surface 12 indicated by the solid line in FIG. Is required. After confirming that the shape of the tooth surface 12 after this correction is within the range of accuracy errors that can be tolerated for the helical gear 1, each helical gear 1 that has measured the tooth surface 12 can be applied to a product. Determine whether or not.

The measuring device 60 that measures the shape of the tooth surface 12 of the helical gear 1 includes, for example, the center of the rotating shaft 30 on which the gear is mounted due to the expansion or contraction of the material that occurs due to a change in the temperature environment. In some cases, errors in machine accuracy such as displacement and inclination of the column 33 with respect to the vertical direction may occur. By using the correction value C _comp as a correction value for the actual measurement value of the shape of the tooth surface 12 along the meshing advance direction, the shape of the tooth surface 12 along the meshing progress direction can be more accurately determined. Can be sought.

  If the shape of the tooth surface 12 is out of an allowable error range after correction, that is, excluding the machine accuracy error, the helical gear 1 having such a tooth surface 12 is rotated using the product. And gear noise occurs. In such a case, the helical gear 1 having the shape of the tooth surface 12 outside the allowable error range is removed from the production line, while the deviation of the accuracy of the tooth surface 12 with respect to the master accuracy is Can be fed back to the manufacturing process. As a result, the shape of the tooth surface 12 of each helical gear 1 can be adjusted, and the deviation of the accuracy of the tooth surface 12 can be reduced, so that gear noise can be reduced.

As described above, in the method for measuring the shape of the tooth surface 12 of the helical gear 1 according to the present embodiment, the actual measurement value of the shape of the tooth surface 12 is measured along the meshing direction of the helical gear 1. A step (S60) and a step (S70) of calculating the shape of the tooth surface 12 by multiplying the actual measurement value by the correction value C _comp of the mechanical accuracy error in the meshing direction.

In this way, it is possible to accurately correct the mechanical accuracy error of the measuring device 60 (see FIG. 1) that measures the tooth surface 12 along the advancing direction. That is, it is possible to calculate an accurate correction value C _comp for the actual measurement value of the shape of the tooth surface 12 along the meshing direction. Therefore, since the measurement accuracy of the shape of the tooth surface 12 along the meshing direction of each tooth 10 of the helical gear 1 can be improved, the shape of the tooth surface 12 along the meshing direction of each tooth 10 is accurately determined. Can be managed and evaluated. Therefore, gear noise and vibration due to the meshing of the helical gears 1 are reduced, and noise can be suppressed.

  Although the embodiment of the present invention has been described as above, the embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1 Helical gear, 10, 20 teeth, 12 tooth surfaces, 13 working surfaces, 14 tooth tips, 15 tooth roots, 16, 17, 18, 19 edges, 36 stylus, 50 control unit, 60 measuring device.

Claims (2)

A gear tooth surface shape measuring device for measuring a tooth surface shape along a gear meshing traveling direction,
A measuring unit for measuring the tooth surface shape;
A control unit for controlling the operation of the measurement unit,
The control unit calculates the tooth surface shape by multiplying the actual measurement value of the tooth surface shape along the meshing traveling direction measured by the measurement unit by a correction value C _comp obtained by the following equation. Tooth surface shape measuring device.

Where C _CV is a correction value for a mechanical accuracy error in the tooth profile direction, C _LD is a correction value for a mechanical accuracy error in the tooth trace direction, α is an angle formed by the tooth profile direction and the meshing direction, and β is the gear. Represents the torsion angle on the basic cylinder. A method for measuring a tooth surface shape of a gear, measuring a tooth surface shape along a gear meshing traveling direction,
Measuring the actual measurement value of the tooth surface shape along the meshing direction;
And a step of calculating the tooth surface shape by multiplying the actual measurement value by a correction value C _comp obtained by the following equation.

Where C _CV is a correction value for a mechanical accuracy error in the tooth profile direction, C _LD is a correction value for a mechanical accuracy error in the tooth trace direction, α is an angle formed by the tooth profile direction and the meshing direction, and β is the gear. Represents the torsion angle on the basic cylinder.

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