JP2020067428A - Spring shape measurement instrument - Google Patents

Abstract

To solve such a problem that a conventional spring shape measurement instrument is difficult to be miniaturized.SOLUTION: One aspect of a spring shape measurement instrument according to the present invention includes: an imaging part 15 which captures a projection image of a spring 21; a support shaft 13 which is provided so as to protrude to an imaging area of the imaging part 15 in the direction in parallel with an imaging surface of the imaging part 15 and supports the spring 21 so as to support the inner periphery of the spring 21 with a portion along the shaft direction; a support shaft drive part 22 which rotates the support shaft 13 around the central axis of the support shaft 13; a projection image acquisition part 23 which acquires a plurality of projection images by making the imaging part 15 to capture the projection images for respective side surfaces of the spring 21; and a projection image analysis part 24 which calculates a parameter of the spring 21 with the arithmetic operation on the basis of the plurality of projection images.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a spring shape measuring instrument, for example, a spring shape measuring instrument that measures shape parameters such as a free length of a spring and a wire diameter that define a shape of a spring.

  The shape of the winding spring is not flat because both ends have cut-off ends of the winding, and the coil shape of the spring is formed by winding a wire rod a plurality of times. That is, the winding spring has a complicated shape, and it is very difficult to measure whether the shape is within the standard. Therefore, Patent Document 1 discloses an example of a method of measuring the winding spring.

  The method for measuring the shape of a coil spring described in Patent Document 1 includes an arranging step in which both ends of the coil spring are located on a preset rotation axis and the coil spring is arranged to be rotatable around the rotation axis. And a measuring step of measuring the surface shape of the coil spring arranged with a non-contact type displacement meter, and in the measuring step, when measuring the surface shape of at least a part of the wire of the coil spring, It is characterized in that the measurement site is irradiated with light from a plurality of different directions to measure the surface shape of the measurement site.

Japanese Patent Publication No. 2016-104651

  However, in the method for measuring the shape of the coil spring described in Patent Document 1, it is necessary to irradiate the same measurement site with light from a plurality of different directions using a plurality of non-contact type displacement gauges, and the number of parts of the device is small. There is a problem that the number of devices increases and it is difficult to downsize the device.

  The present invention has been made in view of the above circumstances, and an object thereof is to reduce the size of an apparatus with a simple configuration.

  One aspect of a spring shape measuring instrument according to the present invention is a spring shape measuring instrument that measures a parameter that defines the shape of a spring, and a photographing unit that photographs a projected image of the spring and a photographing surface of the photographing unit. A support shaft that is provided so as to project in the imaging area of the imaging unit in a parallel direction and that supports the spring so as to support the inner circumference of the spring with a portion along the axial direction, and a central axis of the support shaft. A support shaft drive unit that rotates the support shaft about a center; a projection image acquisition unit that acquires a plurality of the projection images by causing the imaging unit to capture the projection images for different side surfaces of the spring; A projection image analysis unit that calculates the parameter of the spring based on the projection image.

  According to the spring shape measuring instrument of the present invention, the spring shape measuring instrument can be downsized with a simple configuration.

1 is an external view of a spring shape measuring instrument according to a first embodiment. FIG. 3 is a block diagram illustrating a processing block of the spring shape measuring instrument according to the first embodiment. FIG. 3 is a diagram illustrating a method of installing a spring on the spring shape measuring instrument according to the first embodiment. FIG. 3 is a side view of the spring when the spring is installed in the spring shape measuring instrument according to the first embodiment, and a view for explaining a projected image obtained by the spring shape measuring instrument. 3 is a flowchart illustrating the operation of the spring shape measuring instrument according to the first embodiment.

  For clarity of explanation, the following description and drawings are appropriately omitted and simplified. Each element illustrated in the drawings as a functional block that performs various processes can be configured by a CPU (Central Processing Unit), a memory, and other circuits in terms of hardware, and can be configured by a memory in terms of software. It is realized by the program loaded in. Therefore, it is understood by those skilled in the art that these functional blocks can be realized in various forms by only hardware, only software, or a combination thereof, and the present invention is not limited to them. In each drawing, the same elements are denoted by the same reference numerals, and redundant description is omitted as necessary.

  Further, the program described above can be stored in various types of non-transitory computer-readable media and supplied to the computer. Non-transitory computer readable media include various types of tangible storage media. Examples of non-transitory computer readable media include magnetic recording media (eg, flexible disk, magnetic tape, hard disk drive), magneto-optical recording media (eg, magneto-optical disk), CD-ROM (Read Only Memory), CD-R, It includes a CD-R / W and a semiconductor memory (for example, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (Random Access Memory)). Further, the program may be supplied to the computer by various types of transitory computer-readable media. Examples of transitory computer-readable media include electrical signals, optical signals, and electromagnetic waves. The transitory computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.

Embodiment 1
In the following description, a measuring device that measures the shape of a non-measurement object will be described. The measuring instrument to be described has an effect particularly when measuring the shape of the spring, and hence the measuring instrument is hereinafter referred to as a spring shape measuring instrument.

  FIG. 1 shows an external view of a spring shape measuring instrument 1 according to the first embodiment. As shown in FIG. 1, in the spring shape measuring instrument 1, a display 12 for displaying a user interface screen and measurement results is attached to a cubic housing 10 via a display arm 11. Further, the housing 10 is provided with a recessed portion, and the support shaft 13, the light emitting unit 14, and the imaging unit 15 are provided in the recessed portion. In the spring shape measuring instrument 1, when measuring the shape of the spring, the spring, which is a non-measurement object, is set to be inserted into the support shaft 13. Details of how to install the spring during measurement will be described later.

  In the example shown in FIG. 1, the light emitting unit 14 is provided in the lower portion and the photographing unit 15 is provided in the upper portion. The light emitting unit 14 and the photographing unit 15 are arranged so as to face each other. The spring shape measuring device 1 is provided so as to project into the photographing area of the photographing unit in a direction parallel to the photographing surface of the photographing unit 15. In the example shown in FIG. 1, the support shaft 13 is provided so as to project between the light emitting unit 14 and the image capturing unit 15 in a direction orthogonal to the direction in which the support shaft 13 extends from the light emitting unit 14 toward the image capturing unit 15. The support shaft 13 supports the spring so that the inner circumference of the spring is supported by a part along the axial direction when the spring is measured.

  The light emitting unit 14 is not limited to the position facing the image capturing unit 15, and may be, for example, a ring-type illumination provided along the outer periphery of the image capturing unit 15 as long as it illuminates a non-measurement object. If the light emitting unit 14 is not provided at a position facing the image capturing unit 15, the projected image of the spring 21 is not formed on the image capturing surface of the image capturing unit 15. Therefore, in this case, the projection image of the spring 21 is generated by image processing from the image photographed by the photographing unit 15. If the light emitting unit 14 is not provided at a position facing the imaging unit 15, the spring 21 is reflected depending on the material of the spring 21, the type of the light source, and the irradiation direction of the illumination light, and the projected image of the spring 21 is displayed as an image. It may not be generated by the processing, and it is necessary to adjust the light source to prevent such a projection image defect due to reflection. On the other hand, when the light emitting unit 14 is provided at a position facing the photographing unit 15, a phenomenon such as reflection does not occur regardless of the material of the spring 21, and a projected image of the spring 21 is formed on the photographing surface of the photographing unit 15. . Therefore, when the light emitting unit 14 is provided at a position facing the image capturing unit 15, the captured image can be directly used as the projection image.

  Further, the spring shape measuring instrument 1 is provided with operation buttons 16-18. The operation buttons 16 to 18 are used to directly operate the spring shape measuring instrument 1 without using the user interface displayed on the display 12, and are used to perform predetermined operations such as start, interruption, and end of measurement. It is a thing.

  The spring shape measuring instrument 1 according to the first embodiment calculates a parameter that defines the shape of the spring based on the projected image of the spring obtained by the light emitting unit 14 and the photographing unit 15. Therefore, a processing block provided inside the spring shape measuring instrument 1 according to the first embodiment will be described. FIG. 2 is a block diagram illustrating processing blocks of the spring shape measuring instrument according to the first embodiment.

  In the example shown in FIG. 2, the light flux 20 formed by the light output from the light emitting unit 14 is shown. Further, FIG. 2 shows a state in which a non-measurement object (for example, the spring 21) is set on the support shaft 13. As shown in FIG. 2, the spring 21 is set at a position where it is covered with the light flux 20. The light flux 20 is formed by parallel light that is orthogonal to the light emitting surface of the light emitting unit 14 and is parallel to the direction toward the imaging unit 15. Moreover, from another viewpoint, the light emitting unit 14 outputs parallel light that is orthogonal to the imaging surface of the imaging unit. Here, in the spring shape measuring instrument 1, the parallel light is used as the light output from the light emitting unit 14 so that the size of the projected image of the spring 21 is the same as the size of the spring 21. By using such parallel light, the spring shape measuring instrument 1 can improve the measurement accuracy. The image capturing unit 15 is a camera that captures a projected image of the spring 21 to generate image data.

  As shown in FIG. 2, the spring shape measuring instrument 1 has a support shaft drive unit 22, a projection image acquisition unit 23, a projection image analysis unit 24, and a measurement control unit 25 as processing blocks. The support shaft drive unit 22 is a motor that rotates the support shaft 13 around the center shaft of the support shaft 13. The support shaft drive unit 22 rotates the support shaft 13 according to an instruction from the measurement control unit 25. Further, the spring 21 rotates in accordance with the rotation of the support shaft 13. At this time, the rotation center axis of the support shaft 13 and the rotation center axis of the spring 21 are displaced from each other.

  The projection image acquisition unit 23, the projection image analysis unit 24, and the measurement control unit 25 are arithmetic devices capable of executing programs, such as a microprocessor. The projection image acquisition unit 23, the projection image analysis unit 24, and the measurement control unit 25 may be configured by one microprocessor or may be configured by individual microprocessors. In addition, the projection image acquisition unit 23, the projection image analysis unit 24, and the measurement control unit 25 represent the functions realized by the program executed on the microprocessor as processing blocks.

  The projection image acquisition unit 23 instructs the photographing unit 15 to photograph the projected image based on the instruction of the measurement control unit 25. At this time, in the spring shape measuring instrument 1 according to the first embodiment, the support shaft drive unit 22 rotates the support shaft 13 so that projected images of different side surfaces of the spring 21 are generated by the light emitting unit 14 and the imaging unit 15. You can do it. Therefore, the projection image acquisition unit 23 acquires a plurality of projection images by causing the imaging unit 15 to capture the projection image for each different side surface of the spring 21.

  The projection image analysis unit 24 calculates a parameter that defines the shape of the spring 21 based on the plurality of projection images acquired by the projection image acquisition unit 23. As an example of this calculation, there is a method of generating a waveform graph connecting the vertices that are known from the shape of the spring 21 in each projected image from a plurality of projected images and calculating the parameters of the shape of the spring 21 based on this waveform graph. is there. Further, the projection image analysis unit 24 outputs the parameter values of the spring 21 and the analysis result to the display 12.

  The measurement control unit 25 controls the support shaft drive unit 22 and the projection image acquisition unit 23 to acquire a plurality of projection images of the spring 21.

  Here, a method of installing the spring 21 and the projected image of the spring 21 in the spring shape measuring instrument 1 according to the first embodiment will be described. Therefore, FIG. 3 shows a diagram for explaining a method of installing a spring in the spring shape measuring instrument according to the first embodiment.

  As shown in FIG. 3, in the spring shape measuring instrument 1, when the spring 21 is measured, the spring 21 is installed on the support shaft 13 so that the support shaft 13 penetrates the inside of the spring 21. Further, when the spring 21 is installed on the support shaft 13, the support shaft 13 supports the inner circumference of the spring with a part along the axial direction. As a result, in the state where the spring 21 is installed on the support shaft 13, a deviation occurs between the rotation center axis of the support shaft 13 and the rotation center axis of the spring 21. This deviation is, for example, a form in which the two rotation center axes are located at different positions in the vertical direction. When the support shaft drive unit 22 rotates the support shaft 13, the support shaft 13 rotates about the rotation center axis of the support shaft 13, and the spring 21 rotates about the rotation center axis of the spring 21.

  Further, FIG. 4 shows a side view of the spring when the spring is installed in the spring shape measuring instrument according to the first embodiment and a view for explaining a projected image obtained by the spring shape measuring instrument. As shown in the side view of FIG. 4, in the spring shape measuring instrument 1 according to the first embodiment, in the side view when the spring 21 is installed on the support shaft 13, the support shaft 13 penetrates the inside of the spring 21. Becomes In the spring shape measuring instrument 1, since the support shaft 13 is sufficiently thinner than the inner diameter of the spring 21, the shape of the winding of the spring can be sufficiently determined in the side view of the spring 21. Then, as shown in the projected view of FIG. 4, it shows the contour of the spring 21 when the spring 21 is viewed from the side.

  The spring shape measuring instrument 1 according to the first embodiment captures a projected image of a side surface as shown in the projection view of FIG. 4 for a plurality of side surfaces, acquires a plurality of projected images, and sets a parameter representing the shape of the spring. calculate. In the side view of FIG. 4, an example of parameters to be calculated is shown. In the example shown in FIG. 4, the spring shape measuring instrument 1 calculates the free length L of the spring, the wire diameter d, the spring pitch P, the pitch angle θ1 of the spring winding, and the coil inclination θ2.

  Subsequently, a spring shape measuring method using the spring shape measuring instrument 1 according to the first embodiment will be described. Therefore, FIG. 5 shows a flowchart for explaining the operation of the spring shape measuring instrument according to the first embodiment. The flowchart shown in FIG. 5 shows the operation of the spring shape measuring instrument 1 after the spring 21 is set on the support shaft 13. Further, in FIG. 5, the process up to the non-defective determination of the spring 21 using the spring shape measuring instrument 1 is included.

  As shown in FIG. 5, in the spring shape measurement using the spring shape measuring instrument 1, when the measurement is started, first, the support shaft 13 is rotated to rotate the spring 21 (step S1). Then, a plurality of projected images of the rotating spring 21 are obtained (step S2). Specifically, in step S2, by controlling the light emitting unit 14 from the support shaft driving unit 22, a projected image is captured for each of the plurality of side surfaces of the spring 21, and a plurality of projected images are acquired.

  Then, the projection image analysis unit 24 calculates a parameter that defines the shape of the spring 21 using the plurality of projection images acquired by the projection image acquisition unit 23 (step S3). The parameters calculated in step S3 are, for example, the free length L of the spring 21, the wire diameter d, the spring pitch P, the pitch angle θ1 of the spring winding, and the coil inclination θ2 described in FIG.

  After that, the projection image analysis unit 24 determines whether or not each of the calculated parameters is a value within a preset standard range (step S4). Then, if all the values of the respective parameters are within the range of the standard, it is displayed on the display 12 that the judgment is pass (step S5). On the other hand, if there is a value out of the standard range among the plurality of parameters, the display of the parameter is displayed on the display 12 as being rejected (step S6).

  From the above description, the spring shape measuring instrument 1 according to the first embodiment relates to the plurality of side surfaces of the spring 21 by rotating the spring 21 by the support shaft 13 and by using one set of the light source (light emitting unit 14) and the photographing unit 15. A projected image can be obtained. Then, by analyzing the plurality of projected images corresponding to the plurality of side surfaces, the value of the parameter defining the shape of the spring 21 is calculated. That is, the spring shape measuring instrument 1 according to the first embodiment can obtain a plurality of parameters indicating the shape of the spring 21 with a simple configuration. Thereby, the spring shape measuring instrument 1 can be downsized.

  Further, in the spring shape measuring instrument 1 according to the first embodiment, the spring 21 is set on the support shaft 13 with many degrees of freedom without fixing the spring 21 on the support shaft 13. Even if the spring 21 to be measured is set in this way, the spring shape measuring instrument 1 according to the first embodiment can calculate the parameters of the spring 21 with high accuracy. That is, by using the spring shape measuring instrument 1 according to the first embodiment, it becomes possible for the operator to measure the spring 21 with high accuracy without having an advanced operating skill.

  The present invention is not limited to the above-mentioned embodiments, but can be modified as appropriate without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Spring shape measuring device 10 Housing 11 Display arm 12 Display 13 Support shaft 14 Light emitting part 15 Imaging part 16 Operation button 17 Operation button 18 Operation button 20 Luminous flux 21 Spring 22 Support axis drive part 23 Projection image acquisition part 24 Projection image analysis part 25 Measurement control unit

Claims (4)

A spring shape measuring instrument for measuring a parameter that defines the shape of a spring,
A photographing unit for photographing the projected image of the spring,
A support shaft that is provided so as to project in the shooting area of the shooting unit in a direction parallel to the shooting surface of the shooting unit, and that supports the spring so as to support the inner circumference of the spring with a portion along the axial direction. ,
A support shaft drive unit for rotating the support shaft about a central axis of the support shaft;
A projection image acquisition unit for acquiring a plurality of the projection images by causing the imaging unit to capture the projection image for each different side surface of the spring;
A projection image analysis unit that calculates the parameters of the spring based on a plurality of the projection images,
Shape measuring instrument having a.   The spring shape measuring instrument according to claim 1, further comprising a light emitting unit that outputs parallel light that is orthogonal to the imaging surface of the imaging unit.   The spring shape measuring instrument according to claim 1 or 2, wherein the projection image analysis unit calculates two or more items of the free length of the spring, the wire diameter, the spring pitch, the pitch angle, and the inclination of the coil by calculation. .   The spring shape measuring instrument according to any one of claims 1 to 3, wherein a rotation center axis of the spring and a rotation center axis of the support shaft are at positions displaced from each other.

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