Device and method for detecting presence or absence of missing or excess ball

Abstract

The present invention comprises an observation means that can recognize a ball through an opening of an outside joint member of a constant-velocity universal joint, wherein the observation means can recognize at least one among a ball that is between the outside joint member and a cage, a ball that is between an inside joint member and the cage, a ball that is on the inner diameter side or the outer diameter side of the cage, and a ball that is located in a bottom section of the outside joint member.

Description

Apparatus and Method for Detecting Excessive Ball Shortage

[0001] The present invention relates to an apparatus and a method for detecting excessive ball shortage.

[0002] Generally, a constant velocity universal joint includes an outer joint member having a plurality of track grooves formed on an inner diameter surface, an inner joint member having a plurality of track grooves formed on an 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.

[0003] Therefore, in order for the balls, which are torque transmission members, to stably transmit torque, they need to be interposed between the track grooves of the outer joint member and the track grooves of the inner joint member. Accordingly, a conventional apparatus for detecting the presence or absence of ball shortage in a constant velocity universal joint (Patent Document 1) has been proposed.

[0004] The apparatus for detecting the presence or absence of ball shortage 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 FIGS. 7A and 7B. 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, an inner joint member 6 having a plurality of track grooves 5 formed on an outer diameter surface 4, 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, and a shaft portion 3b protruding from the 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 and 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 the constant velocity universal joint by detecting the flow rate of an air flow meter.

[0009] Japanese Patent Publication No. 2007-212237

[0010] In the method using airflow described in Patent Document 1, the accuracy of detecting whether or not a ball is missing 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, and the device will determine 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.

[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.

[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.

[0020] This is a simplified overall diagram of the ball missing excess detection device according to the present invention. This shows the main part of the constant velocity universal joint to be inspected, and is a perspective view of the opening of the constant velocity universal joint viewed from diagonally above. This shows the main part of the constant velocity universal joint to be inspected, and is a perspective view from a different direction than that of Figure 2A. This is a process diagram showing the steps of the ball missing excess detection method. This is an image showing the ball recognition state, of the ball recognition state between the outer joint member and the cage. This is an image showing the ball recognition state, of the ball recognition between the inner joint member and the cage. This is an image showing the ball recognition state, of the ball recognition state between the outer joint member and the cage and the ball recognition state between the inner joint member and the cage. This is an image showing the ball recognition state, of the ball located at the bottom of the outer joint member. This shows a constant velocity universal joint when the observation range on the inner diameter side of the cage is narrowed, and is a plan view of the joint opening viewed from above. This shows a constant velocity universal joint when the observation range on the inner diameter side of the cage is narrowed, and is an enlarged view of part X in Figure 5A. This shows a constant velocity universal joint with a wide observation range on the inner diameter side of the cage, and is a plan view of the joint opening seen from above. This shows a constant velocity universal joint with a wide observation range on the inner diameter side of the cage, and is an enlarged view of section Y of Figure 6A. This shows the outer joint member, and is a cross-sectional view. This shows the outer joint member, and is a view from the opening side. This shows the inner joint member, and is a right side view. This shows the inner joint member, and is a front view. This shows the inner joint member, and is a left side view. This is a cross-sectional view of the main part in a state where it is being inspected with a conventional ball missing detection device.

[0021] Embodiments of the present invention will be described below with reference to Figures 1 to 8C. 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, 2A, and 2B, 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, 2A, and 2B, 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 Figures 7A and 7B, 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 curvature center 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 N-N, and the inclination direction is 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 N-N. 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 N-N in the opposite direction to the inclination direction of the track groove 22A.

[0024] Furthermore, as shown in Figures 8A to 8C, 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 N-N, 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 N-N. 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 N-N 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, the track groove 22B of the outer joint member 23 and the track groove 25B of the inner joint member 26 face each other, the opposing track grooves 22A and 25A cross each other, and the opposing track grooves 22B and 25B cross 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] By the way, 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 perform binarization processing as described later. 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 in 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 configured as a microcomputer, for example, with a CPU (Central Processing Unit) at its center, and 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, or 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 4A, a range for recognizing the balls 27 between the outer joint member 23 and the cage 28; as shown in Figure 4B, a range for recognizing the balls 27 between the inner joint member 26 and the cage 28; as shown in Figure 4C, a range for recognizing the balls 27 on the inner and outer diameter sides of the cage 28; and as shown in Figure 4D, 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 a 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 4A to 4D are obtained. For clarity, in Figure 4A, only the ball 27 on the outer diameter side of the cage 28, which is white, is shown with hatching; in Figure 4B, only the ball 27 on the inner diameter side of the cage 28, which is white, is shown with hatching; in Figure 4C, only the balls 27 on the outer and inner diameter sides of the cage 28, which are white, are shown with hatching; and in Figure 4D, 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 4A, 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 4B, 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 4C, 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, 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 4D, 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, as shown in FIG. 4A, if a range for recognizing the balls 27 between the outer joint member 23 and the cage 28 is set, the presence or absence of the balls 27 in this range can be determined; as shown in FIG. 4B, if a range for recognizing the balls 27 between the inner joint member 26 and the cage 28 is set, the presence or absence of the balls 27 in this range can be determined; as shown in FIG. 4C, if a range for recognizing the balls 27 on the inner diameter side and the outer diameter side of the cage 28 is set, the presence or absence of the balls 27 in this range can be determined; and as shown in FIG. 4D, if a range for recognizing the balls 27 located at the bottom of the outer joint member 23 is set, the presence or absence of the balls 27 in this range can be determined.

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

[0044] Incidentally, in FIG. 4B, as shown in FIGS. 5A and 5B, since the wall thickness t of the cage 28 is large, the recognition range on the inner diameter side of the cage 28 becomes small, and the recognizability of the balls 27 on the inner diameter side of the cage 28 is lowered. In such a case, as shown in FIG. 4A, if the range for recognizing the balls 27 between the outer joint member 23 and the cage 28 is adopted, the recognizability of the balls 27 is improved. Further, as shown in FIGS. 6A and 6B, when the wall thickness t of the cage 28 is small, the recognition range on the outer diameter side of the cage 28 becomes small and the recognition range on the inner diameter side of the cage 28 becomes large, if the range for recognizing the balls 27 within the recognition range on the inner diameter side of the cage 28 is adopted, the recognition performance of the balls 27 is improved.

[0045] When the wall thickness of the cage 28 is large and the observation range on the inner diameter side of the cage 28 is narrow, it becomes difficult to recognize the balls 27 between the inner joint member 26 and the cage 28. In such a case, by recognizing the balls 27 between the outer joint member 23 and the cage 28, stable observation of the balls 27 becomes possible. Further, when the observation range on the outer diameter side of the cage 28 is narrow, it becomes difficult to recognize the balls 27 between the outer joint member 23 and the cage 28. In such a case, by recognizing the balls 28 between the inner joint member 26 and the cage 27, stable observation of the balls 27 becomes possible.

[0046] Further, in cases where the observation range on the inner diameter side of the cage 28 is narrowed, or 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. Furthermore, even when 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 is no missing ball 27, by recognizing the ball 27 positioned at the bottom portion 30 of the outer joint member 23, it can be determined that if there is no ball 27 at this position, no excess of balls 27 has occurred, and if there is a ball 27 at this position, it can be determined that an excess of balls 27 has occurred. Note that when recognizing the ball 27 positioned at the bottom portion of the outer joint member 23, it is preferable to arrange the constant velocity universal joint such that the opening 31 of the outer joint member 23 opens upward in the vertical direction. By this arrangement, when an excess of balls occurs, the excess ball 27 will be positioned at the bottom portion 30 (particularly the center of the bottom portion) of the outer joint member 23, which makes the recognition of the excess ball 27 stable.

[0047] Therefore, in the present invention, since image observation is used, it is possible to provide an apparatus and a method for detecting presence or absence of missing or excess balls that can stably 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 prior art.

[0048] Further, 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. As described above, general observation means can be used as the observation means 40. Note that in this case, it is preferable to additionally provide a cover member 43 that covers the optical path. By providing the cover member 43 in this manner, ambient light can be blocked, and each recognition process is 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).

[0051] Without utilizing airflow, it is possible to determine the presence or absence of balls in the torque transmission member of a constant velocity universal joint. The constant velocity universal joint can be either a fixed type or a sliding type.

[0052] 21 Inner diameter surface 22 Track groove 23 Outer joint member 24 Outer diameter surface 25 Track groove 26 Inner joint member 27 Ball 28 Cage 30 Bottom 31 Opening (joint opening) 40 Observation means 41 Illumination means 42 Imaging means S1 Recognition range determination process S2 Imaging process S3 Binarization process S4 Judgment process

Claims

1. A ball missing / excessive ball inspection device for inspecting whether there are missing or excessive balls 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 device further comprising an observation means capable of recognizing the balls 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 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.

2. The ball missing excess 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 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 method inspects whether there are any missing or excessive balls by recognizing the balls from the opening side of the outer joint member of the constant velocity universal joint using an observation means, and is characterized by recognizing and inspecting 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.

Images