Ball Missing Excessiveness Detection Device and Detection Method

Abstract

The present invention provides a ball deficiency detection device and method that are less prone to misidentification of the presence or absence of balls, can determine the presence or absence of balls with high accuracy, and does not complicate the device configuration. [Solution] The constant velocity universal joint is equipped with an observation means capable of recognizing the ball through the opening of the outer joint member, and the observation means is capable of recognizing at least one of the balls between the outer joint member and the cage, the balls between the inner joint member and the cage, the balls on the inner diameter side and outer diameter side of the cage, and the ball located at the bottom of the outer joint member.

Description

TECHNICAL FIELD

[0001] The present invention relates to an apparatus and a method for detecting whether there are excessive missing balls. BACKGROUND ART

[0002] Generally, a constant velocity universal joint includes: an outer joint member having a plurality of track grooves formed on an inner diameter surface thereof; an inner joint member having a plurality of track grooves formed on an outer diameter surface thereof; a plurality of balls interposed between the track grooves of the outer joint member and the track grooves of the inner joint member for transmitting torque; and a cage interposed between the outer joint member and the inner joint member for holding the balls.

[0003] For this reason, in order for the balls, which are torque transmission members, to transmit torque stably, the balls need to be interposed between the track grooves of the outer joint member and the track grooves of the inner joint member. Accordingly, a device for detecting presence or absence of missing balls in a constant velocity universal joint has been proposed in the related art (Patent Document 1).

[0004] The device for detecting presence or absence of missing balls in Patent Document 1 supplies air to the outer joint member and detects the flow rate of air blown out from the inside of the joint. A specific configuration will be described with reference to FIG. 7. As described above, the constant velocity universal joint in this case includes: an outer joint member 3 having a plurality of track grooves 2 formed on an inner diameter surface 1 thereof; an inner joint member 6 having a plurality of track grooves 5 formed on an outer diameter surface 4 thereof; a plurality of balls 7 interposed between the track grooves 2 of the outer joint member 3 and the track grooves 5 of the inner joint member 6 to transmit torque; and a cage 8 interposed between the outer joint member 3 and the inner joint member 6 to hold the balls 7. The outer joint member 3 includes a cup portion 3a having a plurality of track grooves 2 formed on an inner diameter surface 1 thereof, and a shaft portion 3b protruding from a bottom wall of the cup portion 3a.

[0005] In this case, the system includes an air supply pipe 10 inserted through the hole 6a of the inner joint member 6 so that the air outlet 10a reaches the bottom of the outer joint member 3, and a sleeve member 12 having an air discharge passage 11 provided on the outer circumference of the air supply pipe 10. That is, when air is supplied to the air supply pipe 10, it is discharged from the air outlet 10a into the bottom of the outer joint member 3 as shown by arrow A. Once air is supplied into the bottom, this air is discharged through the gaps in the internal components (components consisting of the inner joint member, ball, cage, etc.) from the joint opening as shown by arrow B.

[0006] A sleeve member 12 having an air discharge passage 11 provided on the outer circumference of the air supply pipe 10 is disposed at the joint opening. The air discharge passage 11 is provided in the sleeve member 12, and an air flow meter (not shown) is connected to this air discharge passage 11.

[0007] By the way, if even one of the six or eight balls arranged between the track grooves 2,5 of the outer joint member 3 and the inner joint member 6 is missing, air inside the outer joint member 3 will leak out to the outside through the missing ball, and the flow rate of the air flow meter will decrease accordingly.

[0008] Thus, the ball missing detection device described in Patent Document 1 detects whether or not there are missing balls in a constant velocity universal joint by detecting the flow rate of an air flow meter. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2007-212237 [Overview of the project] [Problems that the invention aims to solve]

[0010] In the method using airflow described in Patent Document 1, the accuracy of detecting the presence or absence of missing balls is unstable. Specifically, the shape of the outer joint member, inner joint member, and cage of the constant velocity universal joint may obstruct the airflow. In such cases, even though air leakage occurs due to a missing ball, the flow rate of the air flow meter does not decrease, leading to a false determination that there is no missing ball despite the actual absence. Furthermore, the method described in Patent Document 1 requires both air supply and detection of the air outflow flow rate, resulting in a relatively complex device configuration.

[0011] Therefore, in view of the above problems, the present invention provides a ball deficiency detection device and detection method that are less prone to misidentification of the presence or absence of balls, can determine the presence or absence of balls with high accuracy, and does not complicate the device configuration. [Means for solving the problem]

[0012] The present invention provides a ball missing excess detection device for inspecting whether there is an excess of balls in a constant velocity universal joint, which comprises an outer joint member having a plurality of track grooves formed on its inner diameter surface, an inner joint member having a plurality of track grooves formed on its outer diameter surface, a plurality of balls interposed between the track grooves of the outer joint member and the track grooves of the inner joint member to transmit torque, and a cage interposed between the outer joint member and the inner joint member to hold the balls. The device includes an observation means capable of recognizing the balls through an opening in the outer joint member of the constant velocity universal joint, and the observation means is capable of recognizing at least one of the balls between the outer joint member and the cage, the balls between the inner joint member and the cage, the balls on the inner diameter side and outer diameter side of the cage, and the ball located at the bottom of the outer joint member.

[0013] According to the ball missing excess detection device of the present invention, the recognition method allows for the recognition of at least one of the following: balls between the outer joint member and the cage, balls between the inner joint member and the cage, balls on the inner and outer diameter sides of the cage, and balls located at the bottom of the outer joint member. In other words, there are four types of recognition: balls between the outer joint member and the cage, balls between the inner joint member and the cage, balls on the inner and outer diameter sides of the cage, and balls located at the bottom of the outer joint member. Furthermore, the recognition may be of any one of the four types, any two of the four, any three of the four, or all four.

[0014] Therefore, if the cage wall thickness is large and the observation range on the inner diameter side of the cage is narrow, it becomes difficult to recognize the ball between the inner joint member and the cage. In such cases, recognizing the ball between the outer joint member and the cage enables stable observation of the ball. Also, if the observation range on the outer diameter side of the cage is narrow, it becomes difficult to recognize the ball between the outer joint member and the cage. In such cases, recognizing the ball between the inner joint member and the cage enables stable observation of the ball.

[0015] Furthermore, if the observation range on the inner diameter side of the cage is narrowed, or if the observation range on the outer diameter side of the cage is narrowed, the system may recognize the balls between the outer joint member and the cage, and the balls between the inner joint member and the cage. Moreover, even if all the balls are interposed between the track groove of the outer joint member and the track groove of the inner joint member, and there are no missing balls, by recognizing the ball located at the bottom of the outer joint member, it can be determined that there is no ball excess if there is no ball, and that there is a ball excess if there is a ball. When recognizing the ball located at the bottom of the outer joint member, it is preferable to position the constant velocity universal joint so that the opening of the outer joint member opens vertically upward. By setting it in this way, if an excess occurs, it will be located at the bottom of the outer joint member (especially at the center of the bottom), and the recognition of the excess ball will be stable.

[0016] The observation means comprises an illumination means for illuminating the opening of the outer joint member of the constant velocity universal joint, and an imaging means for imaging the opening of the outer joint member illuminated by the illumination means. Thus, the observation means can be a general-purpose observation device and can be installed easily and at low cost. In this case, it is preferable to attach a cover member to cover the optical path. By providing a cover member in this way, ambient light can be prevented, and each recognition becomes stable.

[0017] The present invention provides a method for detecting excessive ball shortages in a constant velocity universal joint, comprising: an outer joint member having a plurality of track grooves formed on its inner diameter surface; an inner joint member having a plurality of track grooves formed on its outer diameter surface; a plurality of balls interposed between the track grooves of the outer joint member and the track grooves of the inner joint member to transmit torque; and a cage interposed between the outer joint member and the inner joint member to hold the balls. The method for detecting excessive ball shortages involves recognizing the balls through an opening in the outer joint member of the constant velocity universal joint, and the inspection is performed by recognizing at least one of the balls between the outer joint member and the cage, the balls between the inner joint member and the cage, the balls on the inner and outer diameter sides of the cage, and the ball located at the bottom of the outer joint member.

[0018] According to the ball missing / excess detection method of the present invention, if the observation range on the inner diameter side of the cage is narrowed, or if the observation range on the outer diameter side of the cage is narrowed, the balls between the outer joint member and the cage and the balls between the inner joint member and the cage may be recognized. Furthermore, even if all balls are interposed between the track groove of the outer joint member and the track groove of the inner joint member and there are no missing balls, by recognizing the ball located at the bottom of the outer joint member, it can be determined that there is no ball excess if there is no ball, and that there is a ball excess if there is a ball. When recognizing the ball located at the bottom of the outer joint member, it is preferable to position the constant velocity universal joint so that the opening of the outer joint member opens vertically upward. By setting it in this way, if an excess occurs, it will be located at the bottom of the outer joint member (especially at the center of the bottom), and the recognition of the excess ball will be stable. [Effects of the Invention]

[0019] Because it uses image observation, it is possible to provide a ball missing / excess detection device and method that can reliably and reliably detect the presence or absence of missing or excessive balls even for types of constant velocity universal joints that could not be inspected or were difficult to inspect in the past. [Brief explanation of the drawing]

[0020] [Figure 1] This is a simplified overall diagram of the ball missing excess detection device according to the present invention. [Figure 2] The main parts of the constant velocity universal joint under inspection are shown. (a) is a perspective view of the opening of the constant velocity universal joint seen from diagonally above, and (b) is a perspective view from a different direction than (a). [Figure 3] This is a process diagram showing the steps for detecting whether there is an excessive number of missing balls. [Figure 4]Shows the recognition state of balls, wherein (a) is an image diagram of the recognition state of a ball between an outer joint member and a cage, (b) is an image diagram of recognition of a ball between an inner joint member and a cage, (c) is an image diagram of the recognition state of a ball between the outer joint member and the cage and a ball between the inner joint member and the cage, and (d) is an image diagram of the recognition state of a ball located at the bottom of the outer joint member. [Figure 5] Shows a constant velocity universal joint in a case where the observation range on the inner diameter side of a cage is narrow, wherein (a) is a plan view of the joint opening viewed from above, and (b) is an enlarged view of part X. [Figure 6] Shows a constant velocity universal joint in a case where the observation range on the inner diameter side of a cage is wide, wherein (a) is a plan view of the joint opening viewed from above, and (b) is an enlarged view of part Y. [Figure 7] Shows an outer joint member, wherein (a) is a cross-sectional view, and (b) is a view seen from the opening side. [Figure 8] Shows an inner joint member, wherein (a) is a right side view, (b) is a front view, and (c) is a left side view. [Figure 9] It is a cross-sectional view of essential parts in a state where inspection is performed by a conventional ball missing detection device. MODE FOR CARRYING OUT THE INVENTION

[0021] Embodiments of the present invention will be described below with reference to Figures 1 to 6. Figure 1 shows a ball missing excess detection device according to the present invention, which is a device for detecting the presence or absence of balls in a constant velocity universal joint. In this case, as shown in Figures 1 and 2, the constant velocity universal joint comprises an outer joint member 23 having a plurality of track grooves 22 formed on its inner diameter surface 21, an inner joint member 26 having a plurality of track grooves 25 formed on its outer diameter surface 24, a plurality of balls 27 interposed between the track grooves 22 of the outer joint member 23 and the track grooves 25 of the inner joint member 26 to transmit torque, and a cage 28 interposed between the outer joint member 23 and the inner joint member 26 to hold the balls 27. The outer joint member 23 also consists of a mouth portion 23a having a plurality of track grooves 22 formed on its inner diameter surface 21, and a shaft portion 23b protruding from the bottom portion 30 of the mouth portion 23a. In this case, the inner surface 30a of the bottom portion 30 is a concave curved surface.

[0022] Incidentally, in the constant velocity universal joint shown in Figures 1 and 2, the track grooves 22 and 25 extending substantially axially from the outer joint member 23 and the inner joint member 26 are inclined at a circumferential angle with respect to the axis of the joint, and eight balls 27 that transmit torque are incorporated into the intersecting track grooves 22 and 25 and held by a gauge 28.

[0023] In this case, as shown in Figure 7, the track groove 22 of the outer joint member 23 consists of a first groove 22a and a second groove 22b. The groove 22a has an arc-shaped track centerline Xa with a center of curvature that is not offset axially with respect to the joint center O, and the plane M containing the track centerline Xa and the joint center O is inclined with respect to the joint axis NN, and the inclination directions are formed in opposite directions for adjacent grooves 22a in the circumferential direction. The groove 22b has a track centerline Xb that has a different shape from the track centerline Xa of the groove 22a, and the end A of the centerline Xa of the groove 22a is located axially on the opening side from the joint center O, and the centerline Xb of the groove 7b is connected to the end A. For this reason, the track grooves 22 of the outer joint member 23 have opposing directions of inclination, and one track groove 22 is called track groove 22A and the other track groove 22 is called track groove 22B. The plane M containing the ball trajectory centerline X and the joint center O of the track groove 22A is inclined by an angle γ with respect to the joint axis NN. Furthermore, for the track groove 22B adjacent to track groove 22A in the circumferential direction, the plane M containing the ball trajectory centerline X and the joint center O of the track groove 22B is inclined by an angle γ with respect to the joint axis NN in the opposite direction to the inclination direction of the track groove 22A.

[0024] Furthermore, as shown in Figure 8, the center line Y of the track groove 25 of the inner joint member 26 is formed in a mirror image with respect to the plane P containing the joint center O when the operating angle is 0°, and the center line X of the corresponding track groove 22 of the outer joint member 23. That is, the track grooves 25 of the inner joint member 26 have opposite inclination directions, and one track groove 25 is called track groove 25A and the other track groove 25. The track groove 25 consists of a first groove portion 25a and a second groove portion 25b, and both the ball trajectory center line Ya of the first track groove portion 25a and the ball trajectory center line Yb of the second track groove portion 25b are formed on plane Q. That is, the ball trajectory center line Ya of the first track groove portion 25a and the plane Q containing the joint center O are inclined circumferentially with respect to the joint axis NN, and the inclination directions are formed in opposite directions for adjacent first groove portions 25a in the circumferential direction. In other words, the plane Q containing the ball trajectory centerline Y of the track groove 25A of the inner joint member 26 and the joint center O is inclined by an angle γ with respect to the joint axis NN. For the track groove 25B adjacent to the track groove 25A in the circumferential direction, the plane Q containing the ball trajectory centerline Y of the track groove 25B and the joint center O is inclined by an angle γ with respect to the joint axis NN in the opposite direction to the inclination direction of the track groove 25A. The inclination angle γ is preferably set to 4° to 12°, taking into consideration the operability of the constant velocity universal joint and the spherical width F on the closest side of the track groove 25 of the inner joint member 26.

[0025] The ball trajectory centerline Y of the track groove 25 of the inner joint member 26 configured in this way is formed in a mirror image with respect to the plane P containing the joint center O when the operating angle is 0°, with respect to the ball trajectory centerline X of the corresponding track groove 22 of the outer joint member 23. That is, the track groove 22A of the outer joint member 23 and the track groove 25A of the inner joint member 26 face each other, and the track groove 22B of the outer joint member 23 and the track groove 25B of the inner joint member 26 face each other, with the opposing track grooves 22A and 25A crossing each other, and the opposing track grooves 22B and 25B crossing each other.

[0026] With a constant velocity universal joint configured in this way, it is possible to realize a compact, fixed constant velocity universal joint that has low torque loss and heat generation, high efficiency, can operate at high operating angles, and has excellent strength and durability at high operating angles.

[0027] As shown in Figure 1, this ball missing excess detection device includes an observation means 40 capable of recognizing the balls 27 through the opening 31 of the outer joint member 23 of the constant velocity universal joint. The observation means 40 includes an illumination means 41 that illuminates the opening 31 of the outer joint member 23 of the constant velocity universal joint, and an imaging means 42 that images the opening 31 of the outer joint member 23 illuminated by the illumination means 41. In this case, it is preferable to attach a cover member 43 that covers the optical path. By providing the cover member 43 in this way, ambient light can be prevented, and each recognition can be stabilized. Here, ambient light is light from outside that affects the observation of the observation means 40.

[0028] Incidentally, in the example shown in Figure 1, a so-called ring light is used as the lighting means 41. In this case, the ring light comprises a ring body 44 and a plurality of LEDs 45 attached to the ring body 44 along the circumferential direction, and can directly illuminate the opening 31 of the outer joint member 23.

[0029] The imaging means 42 consists of a camera and a lens system. The camera can be made up of a CCD or CMOS image sensor, etc. That is, it should be able to image light of the illumination wavelength and, as will be described later, be able to perform binarization processing. The lens system can consist of a telecentric lens or a non-telecentric lens, etc. Here, a telecentric lens is a lens designed to maintain a constant magnification regardless of the distance to the object or its position within the field of view, and the dimensions of the object do not change regardless of the object's position. A non-telecentric lens is a lens that is not designed in this way.

[0030] Furthermore, the cover member 43 covers the illumination means 41 and the imaging means 42. By providing the cover member 43 in this way, ambient light can be prevented, and each recognition becomes stable. The illumination means 41 and the imaging means 42 are controlled by a control unit (control means) not shown. The material of the cover member 43 should be such that it can block ambient light such as incandescent light bulbs and sunlight.

[0031] The control unit can be composed of a microcomputer, for example, a CPU (Central Processing Unit) at its core, with ROM (Read Only Memory), RAM (Random Access Memory), etc., interconnected via a bus. A storage device is connected to the microcomputer. The storage device stores the criteria for the decision-making process of the aforementioned decision-making means. The storage device can consist of an HDD (Hard Disc Drive), a DVD (Digital Versatile Disk) drive, a CD-R (Compact Disc-Recordable) drive, an EEPROM (Electronically Erasable and Programmable Read Only Memory), etc. The ROM stores programs and data executed by the CPU.

[0032] Incidentally, the constant velocity universal joint to be inspected is provided with a constant velocity universal joint holding means (not shown) that can position the joint opening 31 (the opening of the mouse portion 23a of the outer joint member 23) in an upward position, as shown in Figure 1. The constant velocity universal joint holding means can be configured, for example, with a robot hand capable of three-dimensional movement and rotational movement. That is, it can be configured with an XYZθ robot, and the robot hand will grip the detachable constant velocity universal joint. The constant velocity universal joint holding means may also be an XYZθ table. Furthermore, instead of an XYZθ robot and XYZθ table, it may be an XYZ robot and XYZ table, an XYZθ robot and XYθ table, or a YZ robot and XY table.

[0033] Next, a method for detecting the presence or absence of missing balls using the ball missing excess detection device configured as described above will be explained. First, as shown in Figure 1, the constant velocity universal joint is positioned so that its joint opening 31 (the opening of the mouth portion 23a of the outer joint member 23) is open upwards.

[0034] Then, the process shown in Figure 3 is performed. In this case, the process includes a recognition range determination step S1, an imaging step S2, a binarization step S3, and a determination step S4.

[0035] The process for detecting excessive ball shortages involves setting (determining) the recognition range of the balls 27 to be recognized. This recognition range determination step S1 includes, as shown in Figure 4(a), a range for recognizing the balls 27 between the outer joint member 23 and the cage 28; as shown in Figure 4(b), a range for recognizing the balls 27 between the inner joint member 26 and the cage 28; as shown in Figure 4(c), a range for recognizing the balls 27 on the inner and outer diameter sides of the cage 28; and as shown in Figure 4(d), a range for recognizing the balls 27 located at the bottom of the outer joint member 23.

[0036] Therefore, in the recognition range determination step S1, the recognition range of the balls 27 to be recognized is set (determined). Specifically, it is set to allow recognition of at least one of the balls 27 between the outer joint member 23 and the cage 28, the balls 27 between the inner joint member 26 and the cage 28, the balls 27 on the inner and outer diameter sides of the cage 28, and the balls 27 located at the bottom of the outer joint member 23.

[0037] Next, after performing the imaging process S2, the image captured (photographed) in the imaging process S2 is subjected to binarization in the binarization process S3. Here, binarization is a process that converts an image into two colors, white and black, by converting pixel values ​​above a set threshold to white and pixel values ​​below a certain value to black. As a result, black and white images like those in Figures 4(a) to (d) are obtained. For clarity, in Figure 4(a), only the ball 27 on the outer diameter side of the cage 28, which is white, is shown with hatching; in Figure 4(b), only the ball 27 on the inner diameter side of the cage 28, which is white, is shown with hatching; in Figure 4(c), only the ball 27 on both the outer and inner diameter sides of the cage 28, which is white, is shown with hatching; and in Figure 4(d), only the ball 27 located at the bottom of the outer joint member 23, which is white, is shown with hatching.

[0038] In the black and white image of Figure 4(a), the end face of the inner joint member 26, the end face of the cage 28, the end face of the outer joint member 23, and the ball 27 on the outer diameter side of the cage 28 are shown in white, while the rest are shown in black. This makes it possible to recognize the ball 27 between the outer joint member 23 and the cage 28.

[0039] In the black and white image of Figure 4(b), the end face of the inner joint member 26, the end face of the cage 28, the end face of the outer joint member 23, and the ball 27 on the inner diameter side of the cage 28 are shown in white, while the rest are shown in black. This makes it possible to recognize the ball 27 between the inner joint member 26 and the cage 28.

[0040] In the black and white image of Figure 4(c), the end faces of the inner joint member 26, the end face of the cage 28, the end face of the outer joint member 23, the inner diameter side of the cage 28, and the ball 27 are shown in white, while the rest are shown in black. This makes it possible to recognize the ball 27 on both the inner and outer diameter sides of the cage 28.

[0041] In the black and white image of Figure 4(d), the end face of the inner joint member 26, the end face of the cage 28, the end face of the outer joint member 23, and the ball 27 located at the bottom of the outer joint member 23 are shown in white, while the others are shown in black. This makes it possible to recognize the ball 27 located at the bottom of the outer joint member 23.

[0042] Therefore, in the next determination step S4, if a range for recognizing the ball 27 between the outer joint member 23 and the cage 28 is set as shown in Figure 4(a), the presence or absence of the ball 27 in this range can be determined; if a range for recognizing the ball 27 between the inner joint member 26 and the cage 28 is set as shown in Figure 4(b), the presence or absence of the ball 27 in this range can be determined; if a range for recognizing the ball 27 on the inner diameter side and the outer diameter side of the cage 28 is set as shown in Figure 4(c), the presence or absence of the ball 27 in this range can be determined; and if a range for recognizing the ball 27 located at the bottom of the outer joint member 23 is set as shown in Figure 4(d), the presence or absence of the ball 27 in this range can be determined.

[0043] As the judgment step S4, the judgment may be made by an operator observing the binarized image (so-called visual inspection), or it may be made automatically using AI (artificial intelligence), etc.

[0044] By the way, in Figure 4(b), as shown in Figures 5(a) and 5(b), the wall thickness t of the cage 28 is large, so the recognition range on the inner diameter side of the cage 28 is small, and the recognition of the ball 27 on the inner diameter side of the cage 28 is low. In such a case, as shown in Figure 4(a), if the recognition range of the ball 27 is set to the range between the outer joint member 23 and the cage 28, the recognition of the ball 27 will be high. Also, as shown in Figures 6(a) and 6(b), if the wall thickness t of the cage 28 is small, the recognition range on the outer diameter side of the cage 28 is small, and if the recognition range on the inner diameter side of the cage 28 is large, if the recognition range of the ball 27 is set to the recognition range of the ball 27 on the inner diameter side of the cage 28, the recognition performance of the ball 27 will be high.

[0045] If the cage 28 has a large wall thickness and the observation range on the inner diameter side of the cage 28 is narrow, it becomes difficult to recognize the ball 27 between the inner joint member 26 and the cage 28. In such cases, recognizing the ball 27 between the outer joint member 23 and the cage 28 enables stable observation of the ball 27. Also, if the observation range on the outer diameter side of the cage 28 is narrow, it becomes difficult to recognize the ball 27 between the outer joint member 23 and the cage 28. In such cases, recognizing the ball 28 between the inner joint member 26 and the cage 27 enables stable observation of the ball 27.

[0046] Furthermore, if the observation range on the inner diameter side of the cage 28 is narrowed, or if the observation range on the outer diameter side of the cage 28 is narrowed, the balls 27 between the outer joint member 23 and the cage 28 and the balls 27 between the inner joint member 26 and the cage 28 may be recognized. Moreover, even if all the balls 27 are interposed between the track groove 22 of the outer joint member 23 and the track groove 25 of the inner joint member 26, and there are no missing balls 27, by recognizing the ball 27 located at the bottom 30 of the outer joint member 23, it can be determined that there is no excess of balls 27 if there are no balls 27, and that there is an excess of balls 27 if there are balls 27. When recognizing the ball 27 located at the bottom of the outer joint member 23, it is preferable to position the constant velocity universal joint so that the opening 31 of the outer joint member 23 opens vertically upward. By setting it in this way, if an excess occurs, it will be located at the bottom 30 of the outer joint member 23 (especially at the center of the bottom), and the recognition of the excess ball 27 will be stable.

[0047] Therefore, since the present invention uses image observation, it is possible to provide a ball missing excess detection device and method that can reliably and reliably detect the presence or absence of balls 27 even for types of constant velocity universal joints that could not be inspected or were difficult to inspect in the past.

[0048] Furthermore, the observation means 40 includes an illumination means 41 that illuminates the opening 31 of the outer joint member 23 of the constant velocity universal joint, and an imaging means 42 that images the opening 31 of the outer joint member 23 illuminated by the illumination means 41. Thus, the observation means 40 can be a general observation type. In this case, it is preferable to attach a cover member 43 that covers the optical path. By providing the cover member 43 in this way, ambient light can be prevented, and each recognition can be stabilized.

[0049] Although embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be modified in various ways. For example, in addition to ring illumination, the illumination means for observation can generally include bar illumination, square illumination, dome illumination, backlight, coaxial illumination, full-color illumination, spot illumination, ultraviolet / infrared illumination, etc. Any illumination means other than ring illumination can be used as the illumination means for this ball defect count inspection device. As the imaging means, either an area sensor camera or a line sensor camera may be used. Here, an area sensor camera is a camera in which image sensors are arranged vertically and horizontally, and an image can be captured in two dimensions. A line sensor camera has image sensors arranged in a single line, so scanning is required when imaging a certain range. Without scanning, only a one-dimensional image can be captured. For this reason, it is preferable to use an area sensor camera in the present invention. Furthermore, the camera of the imaging means 42 may be a color camera or a monochrome camera.

[0050] By the way, the constant velocity universal joint used to inspect for excessive ball 27 shortages may be a fixed type such as a Zeppa type or an undercut-free type, or a sliding type constant velocity universal joint of the ball type (such as a double offset type). [Explanation of symbols]

[0051] 21 Inner diameter surface 22 Track grooves 23 Outer joint member 24 Outer diameter surface 25 Track grooves 26. Inner joint member 27 Ball 28 cages 30 bottom 31. Opening (joint opening) 40 Observation methods 41 Lighting means 42 Imaging means S1 Recognition range determination process S2 Imaging process S3 Binarization process S4 Judgment process

Claims

1. A ball shortage / excess inspection device for a constant velocity universal joint comprising an outer joint member having a plurality of track grooves formed on its inner diameter surface, an inner joint member having a plurality of track grooves formed on its outer diameter surface, a plurality of balls interposed between the track grooves of the outer joint member and the track grooves of the inner joint member to transmit torque, and a cage interposed between the outer joint member and the inner joint member to hold the balls, wherein the device inspects whether there are any shortages or shortages of balls in the balls, A ball missing / excessive inspection device comprising an observation means capable of recognizing the ball from the opening side of the outer joint member of the constant velocity universal joint, wherein the observation means is capable of recognizing at least one of the ball portion between the outer joint member and the cage, the ball portion between the inner joint member and the cage, the ball portions on the inner diameter side and outer diameter side of the cage, and the ball located at the bottom of the outer joint member.

2. The ball defect count inspection device according to claim 1, characterized in that the observation means comprises an illumination means for illuminating the opening of the outer joint member of the constant velocity universal joint, and an imaging means for imaging the opening of the outer joint member illuminated by the illumination means.

3. A method for inspecting whether there are any missing or excessive balls in a constant velocity universal joint, comprising: an outer joint member having multiple track grooves formed on its inner diameter surface; an inner joint member having multiple track grooves formed on its outer diameter surface; multiple balls interposed between the track grooves of the outer joint member and the track grooves of the inner joint member to transmit torque; and a cage interposed between the outer joint member and the inner joint member to hold the balls, the method for inspecting whether there are any missing or excessive balls in a constant velocity universal joint, A method for inspecting whether there are excessive balls missing, characterized by inspecting at least one of the following: the ball portion between the outer joint member and the cage, the ball portion between the inner joint member and the cage, the ball portions on the inner and outer diameter sides of the cage, and the ball located at the bottom of the outer joint member.

Images