JP2009113167A - Device and method of assembling gear shaft - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for assembling a gear shaft that is reduced in time for assembling a gear shaft, manufacturable at low cost, and easily maintainable, and also to provide a method of assembling the gear shaft. <P>SOLUTION: The gear shaft assembling device includes a six-axis robot and a gear shaft assembling base. A robot hand includes a pressing bracket 53 for pressing a gear 3, and pressingly holds the gear by a pressing part 53a. The robot hand disposes the holding gear near the upper end of the spline of a shaft 2 by inserting the shaft extending downward from the fixed part 42 of the assembling base into the shaft hole of the gear, unclamps the gear, and horizontally rotates, and/or the gear shaft assembling base is horizontally rotated in the opposite direction of the robot hand. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a gear shaft assembling apparatus and an assembling method thereof. Specifically, using a robot and an assembly table, an apparatus for assembling a gear shaft formed by fitting a shaft provided with a male spline portion on the outer peripheral surface and a gear provided with a female spline portion on the inner peripheral surface of the shaft hole, and the assembly thereof Regarding the method.

In gear shafts used in transmissions of automobiles, etc., the male and female spline parts of the shaft and gear may be fitted and assembled by human power or dedicated assembly machines, but either by human power or by dedicated assembly machines. However, the assembly cost of the gear shaft increases. For this reason, assembly of a gear shaft by a robot is required in the automobile industry and the like. The following method is disclosed as a method for fitting a workpiece and an object by a robot.

That is, in the operation of gripping one of the two members to be fitted with the hand at the tip of the robot arm and inserting the one member into the other member, as a method of automating this positioning, A method is known in which the position is detected by a vision sensor or the like attached to a robot arm, and the position is corrected to position the workpiece relative to the hole.

Further, in the improvement of the above method, a robot such that an object such as a workpiece is previously captured and stored as a reference image, and the image of the object captured by a visual sensor is in the same state as the reference image. There is a robot apparatus provided with an auxiliary sensor in the robot arm which performs visual feedback control for controlling the position and orientation of the arm. The robot acquires relation information between the auxiliary sensor and the object by the auxiliary sensor based on the position and orientation of the robot arm when the visual sensor captures the reference image, and stores the information as reference relation information in advance. In addition to the visual feedback control so that the image of the object photographed by the visual sensor is in the same state as the reference image, the relationship information between the auxiliary sensor and the object acquired by the auxiliary sensor Feedback control is performed to control the position and orientation of the robot arm so that is the same as the reference relation information (see Patent Document 1).

Furthermore, in an example of assembling a clutch used for an automatic transmission, as a method of automatically inserting a gear with teeth on the outside into a ring-shaped plate with teeth on the inside while aligning teeth There are the following methods. First, the robot that clamps the gear is moved to a previously taught position in order to drive the robot holding the gear and start inserting the gear into the hole of the plate according to a teaching program or the like. Based on the pre-calculated search reference axis, search axis, search frequency, search range and searchable range of search axis, the speed command in the direction to search is programmed, and the reciprocating motion (rotation) with different period and direction respectively. A reciprocating motion (including reciprocating motion) at the same time to obtain a search operation and control the movement of the workpiece based on the search operation while pressing with a predetermined force in the insertion direction while the gear is in contact with the plate; There is a method of detecting and controlling the force and torque applied to the wrist by a 6-axis sensor provided at the tip of the wrist, and terminating the search operation when the set value of the detected force is exceeded (see Patent Document 2).

JP 2003-31670 A JP 2004-167651 A

However, as a method of assembling a gear shaft by fitting a shaft provided with a spline portion on the outer peripheral surface and a gear provided with a spline portion on the inner peripheral surface of the shaft hole, the method using the vision sensor described above has the following drawbacks. is there. That is, the cost is increased by using the vision sensor. In addition, the environment of a gear shaft assembling site of an automobile or the like often has a disturbance of light such as a forklift headlamp, sunlight, and a component loading / unloading truck, and the pigeon sensor often does not function normally. Furthermore, the tact time of the gear shaft assembly required by the automobile industry is usually within one minute, and it is necessary to attach several gears to the shaft within this tact time. It is not easy to fit and install together. Furthermore, if there is a failure in the assembly work, it is difficult for the person in charge at the site to repair the failure.

In addition, when the method of automatically inserting the above-described gear while inserting teeth into a ring-shaped plate whose teeth are cut inward is used, there are the following drawbacks. That is, a complicated and highly sophisticated program is required, leading to an increase in cost. Also, it may be difficult to complete the assembly within the required tact time. Furthermore, when there is a failure in the assembly work, there is a drawback that it is difficult for the person in charge of the site to repair the failure.

The above two methods increase the flexibility of the robot by making it intelligent and improving its judgment. However, neither method is practical for assembling a gear shaft of an automobile or the like. It has disadvantages that the working environment is not suitable, the cost is high, the tact time is long, and the maintenance is difficult. Therefore, in the automobile industry and the like, the present situation is that the gear shaft is assembled by relying on human power.

SUMMARY OF THE INVENTION An object of the present invention is to provide a gear shaft assembling apparatus and method that have a short tact time for assembling a gear shaft, low apparatus cost, and easy apparatus maintenance. The present invention is used for gear shafts used in transportation equipment such as automobiles and ships, construction equipment, and other transmissions.

The present invention is as follows.
1. Fits the shaft 2 having the spline portion 2a on the outer peripheral surface (in the present invention, the "shaft" means that the gear is not attached) and the gear 3 having the spline portion 3a provided on the inner peripheral surface of the shaft hole. A device for assembling a combined gear shaft 1 (in the present invention, the term “gear shaft” refers to a state in which a gear and a shaft are assembled), and the device includes a robot and a gear shaft assembly base 4. Consists of
The robot hand 5 (hereinafter also referred to as “robot hand”) is
A bracket 53 having a circular hole through which the shaft can be fitted and a cylindrical gear pressing portion 53a, which is attached to the base 51 of the hand via two rods 52 provided with springs and is freely movable. ,
A first gripping claw 54 disposed at a lower portion of the bracket and gripping the gear while being pressed by the bracket;
A first sensor 56 for detecting the presence or absence of the gripped gear;
A second sensor 57 for detecting completion of assembly,
The gear shaft assembly 4 is
A shaft fixing portion 42 for fixing the shaft in a suspended state (in the present invention, “the suspended state” does not mean strict vertical but includes substantially vertical);
An assembly actuator 43 that rotates the shaft in the horizontal direction together with the shaft fixing portion 42, and
The gear shaft assembling apparatus, wherein the robot and the assembly table are controlled by the same robot controller.

The gear shaft assembling apparatus of the present invention is to attach a bracket to the robot hand 5 and hold the gear while pressing the gear, and one assembling table includes an actuator that rotates together with a vertically mounted shaft. After this gear is unclamped, the robot hand is rotated horizontally by the rotating function of the six-axis robot, and one shaft is horizontally rotated by an actuator provided on the mounting base to be fitted. In other words, the problem has been solved by bringing the robot closer to the function of a human hand without advancing the intelligence of the robot. Therefore, the gear shaft assembling apparatus of the present invention does not require a special sensor such as a visual sensor for alignment for fitting the male and female spline portions. Further, there is no need for a fitting place search program or a force or torque control program during fitting.

2. The robot hand has the second gripping claws 55 for gripping the shaft. The gear shaft assembling apparatus as described.
3. The robot is a simultaneous seven-axis control robot that controls the assembly actuator 43 with the same robot controller. The gear shaft assembling apparatus as described. In the present invention, when the fitting clearance is severe and / or the chamfer of the spline portion is small, a 7-axis robot is used to facilitate the assembly of the gear shaft by making the operation of the assembly actuator flexible. is there.

4). The gear shaft assembly 4 includes a second shaft fixing portion 45 for fixing the shaft in a suspended state. Or 2. The gear shaft assembling apparatus as described. In the present invention, when the gear shaft to be assembled is long and unstable only by the fixing portion provided in the gear shaft assembly base, the shaft is supported at two points by using the second gear shaft fixing portion. It is stable and facilitates assembly of the gear shaft.

5). Above 1. A gear shaft assembling method for assembling by assembling the shaft 2 having the spline portion 2a on the outer peripheral surface and the gear 3 having the spline portion 3a on the inner peripheral surface of the shaft hole by using the gear shaft assembling apparatus described above. Because
(A) The robot grips the gear 3 while pressing the gear with the pressing portion 53a of the bracket 53 provided in the robot hand 5;
(B) The robot moves the gripped gear 3, and the shaft hole of the gear and the gear pressing portion 53a are inserted through the shaft suspended from the gear shaft assembly base, and the upper end of the spline portion of the shaft 2 is inserted. Unclamping at a position close to the lower end of the spline part of the gear and the spline part,
(C) The robot moves the hand of the robot downward to a predetermined position and presses the unclamped gear 3 with the pressing portion 53a of the bracket 53, while holding the robot hand 5 to the bracket. And (D) the actuator 43 provided in the assembly base includes the plane center point of the shaft fixing portion 42 provided in the gear shaft assembly base 4 as an axis. Rotating the shaft horizontally,
A gear shaft assembling method comprising: completing the assembly of the gear shaft in the detected step when the robot detects assembly completion in any of the steps (B) to (D).

In the prior art method, the robot grips the workpiece and assembles it with the object. In this method, it is necessary to accurately position both spline surfaces within the fitting clearance. When a moment applied to the wrist of the robot is detected when a workpiece is pressed into an object, a program for reducing this moment is required. Since the method of the present invention solves the problem by unclamping the gear and horizontally rotating the bracket and the shaft while pressing the gear, the program is not required. For this reason, a quick gear shaft can be assembled.

6). 6. The gear shaft assembling method according to 5 above, wherein the steps are in the order of (A), (B), (C), (D).
7). 6. The gear shaft assembling method according to 5 above, wherein the steps are in the order of (A), (B), (C), (D).
8). Further, the above-mentioned 5. The method further comprises the step (E) of double-moving the shaft rotated in the horizontal direction in the step (C) to the state before the rotation. Thru 7. The gear shaft assembling method according to any one of the above.

9. 4. The step of hanging the shaft on the assembly table before the step (A). Thru 8. The gear shaft assembling method according to any one of the above.
10. 4. The robot of the assembly apparatus is a simultaneous seven-axis control robot that controls the assembly actuator 43 with the same robot controller. Thru 9. The gear shaft assembling method according to any one of the above.

If the gear assembling apparatus of the present invention is used, a special sensor such as a visual sensor is not required for alignment for fitting, and a search program for a fitting place and a control program for force and torque at the time of fitting. Therefore, the gear shaft assembly tact time is small, the device is low-cost, and the device is easy to maintain.

In addition, the present invention uses a simultaneous seven-axis control robot that controls the assembly actuator with the same robot controller, and this assembly actuator can be operated more flexibly, so that the clearance of the fitting is severe and / or spline. Even when the chamfering of the part is small, the assembly of the gear shaft is facilitated, the gear shaft assembly tact time is small, the device is low in cost, and the maintenance of the device is easy.

Further, according to the present invention, since the gear shaft assembly base includes the second shaft fixing portion 45, the shaft suspended from the assembly base can be reliably assembled without being unstable.

If the method of the present invention is used, a special sensor program such as a visual sensor, a fitting place search program, and a force and torque control program at the time of fitting are necessary for alignment for fitting. Therefore, the gear shaft assembly tact time is small, the assembly cost is low, and the process maintenance is easy.

Further, according to the method of the present invention, when the assembly of the gear shaft is not completed, it is possible to return to a predetermined process and repeat the assembly process again, so that the gear shaft can be reliably assembled.

The gear shaft assembling apparatus of the present invention comprises a robot and a gear shaft assembling table 4.
(1) Robot This robot can be a general-purpose 6-axis industrial robot. The robot hand 5 includes a bracket 53, a first grip part 54, a first sensor 56, and a second sensor 57.

〔bracket〕
This bracket 53 presses the gear 3 against the upper end portion of the spline portion 2 a of the shaft 2. The bracket includes a cylindrical gear pressing portion 53a. When holding the gear, the bracket holds the gear while pressing the gear downward through the gear pressing portion 53a (see FIG. 5). Even when the gear is unclamped, the bracket passes through the gear pressing portion 53a. To press the gear. Therefore, when the gear is unclamped, the lower end portion 31a of the gear and the upper end portion 21a of the spline portion of the shaft are in contact in a pressed state (see FIG. 6).

The bracket 53 has a circular hole 53b through which the shaft can penetrate at the center. The diameter of the circular hole 53b is larger than the diameter of the shaft hole of the gear and smaller than the diameter of the gear. Any diameter within this range is not particularly limited. The gear pressing portion 53a has a cylindrical shape and is mounted so that its plane center point is the same as the center point of the circular hole of the bracket, and its inner diameter is larger than that of the circular hole 53b (FIGS. 3 and 4).

As described above, the gear pressing portion 53a always presses the spline portion upper end portion 21a of the shaft even after the gear is unclamped even when the gear is unclamped. The gear shaft assembling apparatus of the present invention inserts the gear into the shaft using this pressing force. For this reason, the robot according to the present invention does not require force control for inserting the gears against the shaft.

The bracket is attached to two rods 52 provided with springs 52 a so as to be parallel to the base 51 (see FIG. 1), and these two rods penetrate the base 51 of the robot hand 5. It is attached to the hole so as to be movable up and down (see FIGS. 1 and 5). Therefore, the bracket presses the gear vertically through the spring. Further, since these two rods are attached to both ends of the convex portion of the bracket when viewed from the plane direction (see FIGS. 3 and 4), the pressing portion of the bracket and the gear are almost perpendicular to each other when gripping the gear. Contact with average pressure. The rod is fixed at the upper end by a sensor sensing unit 59.

As will be described later, since the robot unclamps the gear with the robot hand in a horizontal state, the lower surface (lower end) of the gear and the upper surface (upper end) of the shaft spline are in contact with each other at a horizontal and substantially average pressure. . Therefore, the axis in the gear insertion direction and the axis in the shaft insertion direction are substantially coincident. For this reason, when the gear is unclamped, if the spline portion of the gear and the spline portion of the shaft coincide within the clearance, they are fitted (see FIG. 14). Alternatively, if there is chamfering of the shaft and the gear spline part, if they match within the clearance increased by the chamfering amount (see FIG. 15), both male and female splines are fitted. Since the device of the present invention is fitted with the gears unclamped, it is not necessary to control the torque applied to the wrist 50 of the six-axis robot during fitting.

The material of this bracket is not particularly limited. For example, heat such as metal such as aluminum, copper, brass, stainless steel, iron, thermosetting resin such as phenol resin, polyester resin, epoxy resin, urea resin, fluorine resin, polyethylene resin, polypropylene resin, vinyl chloride resin, nylon A plastic resin or hard urethane rubber is used. Of these, metals such as aluminum, copper, brass, stainless steel, and iron are preferably used. This is because aluminum, copper, and brass rarely damage the gear, and iron is inexpensive.

The kind and material of the spring are not particularly limited. It is only necessary that the bracket 53 can press the gear downward. For example, steel coil springs, flat springs, leaf springs, square springs, bamboo shoot springs, air springs, liquid springs, and the like can be used. Of these, steel compression coil springs are preferably used. It is because it is cheap and easy to obtain.

[First gripping claw]
The first gripping claw 54 grips the gear. The first gripping claw 54 is provided at a position below the bracket via a gripping actuator 58 of the robot hand 5 (see FIGS. 1 and 3). The gripping claw 54 is not particularly limited as long as it can grip the gear, but is preferably gripped by a pair of parallel movement type claws (54a, 54b). The shape of these claws is not limited as long as the gear can be gripped, but each of these claws preferably has a V-shaped notch when viewed from the plane direction (see FIGS. 1 to 4). This is because the gear is stably held at four points.

The material of the nail is not particularly limited. Thermosetting resins such as metals such as aluminum, copper, brass, stainless steel, iron, phenolic resins, polyester resins, epoxy resins, urea resins, fluorine resins, thermoplastic resins such as polyethylene resins, polypropylene resins, vinyl chloride resins, nylons Or hard urethane rubber etc. are used. Of these, aluminum, copper, brass and iron are preferably used. This is because aluminum, copper, and brass rarely damage the gear, and iron is inexpensive.

The robot hand according to the present invention preferably has a second gripping claw 55. The second grip claw 55 grips the shaft. The second grip claw 55 is disposed below each of the two claws included in the first grip claw 54. The gripping claw 55 is not limited as long as the shaft can be gripped. These claws are preferably moved in parallel by the actuator 58 described above to grip the shaft at two locations. This is because the shaft is long and stable when gripped at two locations. That is, this gripping claw preferably includes two pairs of claws (four claws 55a, 55b, 55c, and 55d) (see FIG. 4). Although the shape of this nail | claw is not specifically limited, It is preferable to have a V bevel-shaped notch part (refer FIG. 1). This is because each pair of claws grips the shaft at four points, so that gripping of the shaft is stable.

The material of the nail is not particularly limited. Thermosetting resins such as metals such as aluminum, copper, brass, stainless steel, iron, phenolic resins, polyester resins, epoxy resins, urea resins, fluorine resins, thermoplastic resins such as polyethylene resins, polypropylene resins, vinyl chloride resins, nylons Or hard urethane rubber etc. are used. Of these, aluminum, copper, brass and iron are preferably used. This is because aluminum, copper, and brass rarely damage the target workpiece, and iron is inexpensive.

[First sensor]
The first sensor 56 is attached to a sensor bracket provided on the base 51 of the robot hand (see FIG. 1). The first sensor senses the sensor sensing unit 59 that fixes the rod 52 described above. Since the rod 52 moves up and down relatively with respect to the base 51 of the robot hand 5, the first sensor senses the sensor sensing unit 59 when the gripping unit grips the gear, and the robot detects the gear. Is detected (see FIG. 5). The robot moves to the next operation after detecting gripping of the gear.

The type of sensor is not limited as long as it can sense the sensor sensing unit 59. For example, sensors using limit switches, magnets, light, infrared rays, ultrasonic waves, and the like can be used. Among these, a sensor or limit switch using a magnet with a sensor sensing part as a metal is preferably used. This is for inexpensive and reliable detection.

[Second sensor]
The second sensor 57 is provided above the first sensor of the sensor bracket provided on the base 51 of the robot hand (see FIG. 1). A sensor sensing unit 59 for fixing the rod is sensed. If this second sensor senses the sensor sensing part 59, this indicates that the gear shaft is being assembled.

The type of sensor is not limited as long as it can sense the sensor sensing unit 59. For example, sensors using limit switches, magnets, light, infrared rays, ultrasonic waves, and the like can be used. Among these, a sensor using a magnet similar to the first sensor or a limit switch is preferably used. This is for inexpensive and reliable detection.

(2) Gear shaft assembly table The gear shaft assembly table 4 is a table for assembling gears on the shaft. The gear shaft assembly base is installed in a horizontal state. The horizontal state includes not being strictly horizontal but substantially horizontal. The gear shaft assembly 4 includes a shaft fixing portion 42 for fixing the shaft in a suspended state, and an assembly actuator 43 for rotating the shaft suspended from the fixing portion together with the fixing portion in the horizontal direction. Provided (see FIGS. 9 and 10).

[Assembly actuator]
The drive source of the assembly actuator 43 is not particularly limited. For example, air pressure, hydraulic pressure, an electric motor, and an electromagnet can be used. Of these, those using a pneumatic drive source are preferred. This is because it is inexpensive and operates reliably. This actuator rotates by a certain angle about the center point C of the shaft fixing portion 42 when the valve of pressurized air is opened (see FIG. 10). After the assembly actuator 43 is rotated horizontally by a certain angle, it can be double-actuated to the initial position by the switching valve, or can be in a free state.

The switching valve opens and closes in conjunction with the robot using the same controller as the robot. The operation of this switching valve will be described in the gear shaft assembling method using the device of the present invention described later. When the valve is switched and the actuator becomes free, if the assembly is not completed, the double movement is made to the initial position before the horizontal rotation as the robot hand described later rotates. .

[Shaft fixing part]
The shaft fixing portion 42 fixes the shaft arranged perpendicular to the shaft fixing portion 42. Although the vertical arrangement means is not particularly limited, the robot is preferably arranged using the second gripping claw 55 provided in the robot hand. Further, the means for fixing the vertically arranged shaft is not particularly limited. Preferably, it is fixed with a chuck 41 of three claws (41a, 41b, 41c) (see FIG. 10). This is to maintain a stable vertical state.

Another gear shaft assembling apparatus according to the present invention has a simultaneous 7-axis control robot specification in which the assembly actuator 43 is controlled as the seventh axis by the same robot controller. In this robot, the actuator can be horizontally rotated more flexibly by a robot teaching or program. For example, the horizontal rotational movement speed can be freely adjusted, and pitch feed can be performed at an arbitrary angle. Further, the double-acting speed of the actuator can be freely adjusted. Further, it is possible to perform the horizontal rotational motion while applying vibration.

This simultaneous 7-axis control robot is particularly effective because it can operate more flexibly than the actuator used in the above-described assembly table when the clearance m for fitting is small or when the cline of the spline part is small and the clearance n is small. (See FIGS. 14 and 15).

Another gear shaft assembling apparatus of the present invention includes a second shaft fixing portion 45 for fixing a shaft suspended on the shaft assembling table 4 in a stable state (see FIGS. 11 and 12). The second shaft fixing portion includes a driving portion 47 and a pair of claws 46, and the pair of claws 46 can be opened and closed by using the driving portion 47 (see FIGS. 11 and 12). The second shaft fixing portion 45 closes the pair of claws 46 at a position where the spline portion of the shaft is not provided after the shaft fixing portion 42 of the shaft assembly base hangs and fixes the shaft. Fix it. Normally, the pair of claws 46 provided in the second shaft fixing portion 45 are closed and fixed when the robot is in the process of assembling the gear shaft, but the robot hand 5 holding the gear holds the shaft. When it is inserted, it is opened once and this shaft is opened. Thereafter, the claws are closed again to fix the shaft. Further, when the assembly of the shaft gear is completed, the claw 46 is opened to open the gear shaft.

The usage method of the gear shaft assembling apparatus of the present invention is as follows.
(1) The shaft 2 is vertically arranged on the gear shaft assembly base. Although the arrangement method is not particularly limited, it is preferable that the robot of the present application arranges. The robot hand 5 grips the shaft 2 with the second gripping claw 55 and vertically places it on the shaft fixing portion 42 of the gear shaft assembly base 4. The vertical / arrangement positions of the shaft are set such that the central position when the shaft is viewed from the bottom surface is overlapped with the center point C (see FIG. 10) when the shaft fixing portion is viewed from the planar direction. This operation can be performed by a teaching program.

(2) The shaft is fixed when the shaft 2 is disposed vertically at the center point C of the shaft fixing portion 42. The fixing method is not particularly limited, but preferably the shaft is fixed and installed by the chuck 41 of three claws (41a, 41b, 41c) (see FIG. 10). This operation can be performed by the robot controller described above.

(3) The first gripping claw 54 of the robot hand grips the gear 3. FIG. 5 is an explanatory view when the first gripping claw 54 of the robot hand grips the gear 3 in this step. As shown in FIG. 5, when the gripping claw 54 of the robot grips the gear 3, the gear pressing portion 53a of the bracket 53 presses the gear and then grips the gear while pressing it. When this gear is gripped, the rod 52 rises relative to the hand base 51. For this reason, the sensor sensing unit 59 fixed to the rod is sensed by the first sensor 56, and the robot can detect that the gear has been gripped and can proceed to the next operation.

After the robot detects the gripping of the gear, the robot passes through the shaft hole 3b of the gear through the shaft 2 suspended from the shaft fixing portion 42 of the assembly base, and the robot is provided with the shaft. It arrange | positions in the proximity | contact state to the upper end part 21a of a spline part. FIG. 6 is an explanatory view of the above-described operation in this process as viewed from the front. FIG. 7 is an explanatory view of the above operation as viewed from the side. The above-mentioned proximity state means that the spline part of the shaft and the spline part of the gear are arranged so close to each other, and includes the case where both the spline parts are in contact. The gear 3 arranged in this state is pressed by the pressing portion 53a of the bracket 53. This operation can be performed by normal teaching.

(4) The robot unclamps the gear that is close to and disposed near the upper end portion 21a of the spline portion of the shaft. Even after the robot unclamps the gear, the bracket continues to press the gear downward. When the pressed gear is unclamped, both spline portions are fitted together to assemble the gear shaft, or the gear remains at the upper end portion 21a of the shaft without being assembled. When the gear shaft is assembled by the above fitting, the bracket moves relative to the robot base 51, so the first sensor 56 does not sense the sensor sensing unit 59. When the first sensor 56 does not sense the sensor sensing unit 59, the robot detects the assembly of the gear shaft, and the assembly is completed.

(5) When the robot does not detect assembly in the above process (when the first sensor 56 senses the sensor sensing unit 59), the robot moves the robot hand 5 downward at a predetermined position (for example, the thickness of the gear). Position where the second sensor is lowered, or a position where the second sensor can sense the sensor sensing unit). For this reason, the gear 3 is strongly pressed by the spring further downward by the bracket pressing portion 53a. FIG. 8 is an explanatory view of the above operation in this step as viewed from the side. In the downward movement of the robot hand, both male and female splines may be engaged. In this case, the rod 52 is lowered relative to the base 51 of the robot hand 5, and the first sensor 56 senses the sensor sensing unit 59, while the second sensor 57 senses the sensor sensing unit 59. Not perceived. At this time, the robot detects that the gear shaft has been assembled and ends the gear shaft assembling process.
When the two splines are not fitted, the second sensor 57 then senses the sensor sensing unit 59. When this sensor sensing unit is sensed, the robot rotates the robot hand 5 in the horizontal direction around the plane center point of the circular hole of the bracket. For this reason, the gear pressed against the bracket generates a rotational stress in the horizontal direction as the robot hand rotates.

Due to this stress, the gear 3 moves in one of the following ways.
(A) The gear rotates with the bracket and rotates horizontally in the same direction as the bracket.
(B) The gear rotates in the same direction as the bracket while sliding between the bracket and the bracket.
(C) The gear slips between the bracket and does not rotate horizontally.
In this step, the movement of the gear may be any of the above (a), (b), or (c), but preferably the above-described spring 52a is selected so as to achieve the above movement (b). To do. This is because in this case, the fitting is often performed particularly smoothly. This rotation direction may be any direction. Moreover, you may rotate in the opposite direction, after rotating to a fixed angle to one side.
When the spline portions are fitted together during the rotation and the assembly is completed, the rod 52 is lowered relative to the base 51 of the robot hand 5. Accordingly, the second sensor 57 does not sense the sensor sensing unit 59. Therefore, the robot detects that the gear shaft has been assembled and ends the gear shaft assembling process.

(6) If the robot does not detect the completion of the assembly of the gear shaft in the above process, the assembly actuator 43 rotates a certain angle in the horizontal direction around the center position C of the shaft fixing portion 42. This rotation direction may be the same as or opposite to the rotation direction of the robot hand, but it is preferable to rotate in the opposite direction. The rotation angle is not particularly limited, but is preferably 1 to 90 degrees, more preferably 1 to 45 degrees, and particularly preferably 2 to 20 degrees. This is because when the rotation is within this range, both spline portions often fit smoothly.
At this time, when both the spline portions are fitted, the rod 52 described above descends relative to the base 51 of the robot hand 5. For this reason, the second sensor 57 does not sense the sensor sensing unit 59. Therefore, the robot detects that the gear shaft has been assembled, and the gear shaft assembling process ends. As described above, after the second sensor 57 once senses the sensor sensing unit 59, regardless of whether or not the first sensor senses the sensor sensing unit 59, the sensor sensing unit 59 is no longer sensed. This robot detects the assembly of the gear shaft, and the gear shaft assembly process is completed.

(7) The robot can unclamp the gear, and then the assembly actuator 43 can be rotated by a certain angle in the horizontal direction around the center position C of the shaft fixing portion 42. In this operation, when both spline portions are fitted, the rod 52 described above is lowered relative to the base 51 of the robot hand 5. Therefore, since the first sensor does not sense the sensor sensing unit, the robot detects the assembly of the gear shaft, and the gear shaft assembly process ends.
If the assembly of the gear shaft is not completed by the above operation, the robot hand 5 is then moved downward by a predetermined position. Thereafter, when the second sensor 57 senses the sensor sensing unit 59, the robot hand 5 is moved. 5 can also be rotated in the horizontal direction about the plane center point of the circular hole provided in the bracket.
Further, when the assembly actuator 43 is rotated, the robot hand 5 is simultaneously moved downward by a predetermined position. Then, when the second sensor 57 detects the sensor sensing unit 59, the robot hand 5 is moved to the bracket. It can also be rotated in the horizontal direction around the center point of the plane of the circular hole provided.

(8) If the assembly is not completed in the above process, the assembly actuator 43 is double-rotated horizontally to the initial position. When the drive source of this actuator is air, it can be performed as follows. When the rotation direction of the assembly actuator 43 is opposite to the robot hand, the valve of the assembly actuator 43 is closed and the air relief valve is opened. Accordingly, the assembly actuator 43 becomes unconstrained and double-rotates to the initial position as the bracket rotates. Another method can be double-rotated to an initial position using a switching valve. Further, when the rotation direction of the assembly actuator 43 is the same as that of the robot hand, the double rotation is performed to the initial position using the switching valve. This double rotation may be performed at any time. When the gear and the shaft are fitted in this double-action process, the second sensor 57 does not detect the sensor sensing unit 59, so the robot detects that the gear shaft has been assembled, and the gear shaft assembling process ends. .

(9) If the gear shaft assembly is not completed in the above step, the assembly actuator that has returned to the initial position before the rotation can be horizontally rotated again by a certain angle. If this rotation does not complete the assembly of the gear shaft, the horizontal rotation of the assembly actuator can be repeated any number of times. Usually it is finished in 3 times. This is because, when the assembly of the gear shaft is not completed after three reciprocations, it is considered that there is some abnormality in the gear and / or the shaft.

Another gear shaft assembling method of the present invention uses a simultaneous 7-axis control robot specification in which the assembling actuator 43 is controlled as the seventh axis by the same robot controller. Since the operation of the assembly actuator 43 can be made flexible by teaching or a program, the both spline portions can be fitted more smoothly. That is, the horizontal rotation speed of the actuator can be freely adjusted, and the rotation angle can be arbitrarily determined.
Moreover, the process of fixing a shaft by the 2nd shaft fixing | fixed part 45 of a gear shaft assembly stand can also be inserted between each said process. This method is effective in the case where the shaft is long and it is difficult to reliably fix the shaft only with the shaft fixing portion 42 of the assembly base.

Examples of the present invention will be described below. The robots, shafts and gears used are as follows.
(1) Robot used: Articulated 6-axis robot (2) Shaft: Shaft with five male spline parts First spline part: 40.7 mm in diameter (shaft diameter excluding the spline part 38.0 mm)
Second spline part: diameter 38.0 mm (shaft diameter excluding spline part 35.0 mm)
Third spline part: diameter 38.0 mm (shaft diameter 35.0 mm excluding spline part)
Fourth spline part: diameter 38.0 mm (shaft diameter excluding spline part 35.0 mm)
Fifth spline part: diameter 37.5 mm (shaft diameter 35.0 mm excluding spline part)
(3) Gear: 5 pieces Gear hole of the first gear: diameter 38.6 mm (female spline part is attached to this hole)
Gear hole of the second gear: diameter 35.8 mm (a female spline part is attached to this hole)
Gear hole of the third gear: diameter 36.0 mm (a female spline part is attached to this hole)
Gear hole of the fourth gear: diameter 36.0 mm (female spline part is attached to this hole)
Gear hole of the fifth gear: diameter 35.9 mm (female spline part is attached to this hole)

Other specifications are as follows.
Material of bracket and bracket pressing part: Aluminum First sensor and second sensor: Magnet proximity switch First claw shape: V-shaped beveled incision to grip the gear at 4 points

The first spline portion to the fifth spline portion are sequentially attached to one shaft. The first spline portion includes the first gear, the second spline portion includes the second gear, the third spline portion includes the third gear, the fourth spline portion includes the fourth gear, and the second spline portion. The fifth gear was sequentially assembled in five spline portions, and the assembly was completed when all five gears were assembled on the shaft. The shaft and gear are used for transmissions used in ordinary passenger cars, and the shaft and the spline part of the gear are usually chamfered. The gear shaft was assembled according to the operation diagram of FIG. 16 using 160 shafts and 800 gears.

The results are shown in the table below. Those that could not be assembled even if the E step was repeated three times were considered as impossible to assemble. In this embodiment, the assembly of all 160 shafts was completed.
The assembly time of one shaft was an average of 50 seconds. As a result, it can be seen that most gears and shafts are fitted in the B process and the C process. The assembly completion time of one shaft is 50 seconds on average, and it can be seen that the efficiency is equal to or higher than that performed by a human.

It is a front view of the robot hand concerning the present invention. It is a side view of the robot hand concerning the present invention. It is a top view of the robot hand concerning the present invention. It is a bottom view of the robot hand concerning the present invention. It is a schematic explanatory drawing when holding a gear. It is a model front explanatory view when a gear is unclamped. It is a model side surface explanatory view when unclamping a gear. It is model explanatory drawing when rotating a hand. It is a front view of the gear shaft assembly stand which concerns on this invention. It is a top view of the gear shaft assembly stand which concerns on this invention. It is a front view of the gear shaft assembly stand which has the 2nd shaft fixing | fixed part which concerns on this invention. It is a top view of the state where the nail | claw of the 2nd shaft fixing | fixed part which concerns on this invention was opened. It is decomposition | disassembly explanatory drawing of the gear shaft which concerns on this invention. It is fitting explanatory drawing in case there is no chamfering in the spline part of the gear and shaft which concern on this invention. It is fitting explanatory drawing in case there exists chamfering in the spline part of the gear and shaft which concern on this invention. It is an operation | movement diagram of an Example.

Explanation of symbols

1. 1. gear shaft, Shaft, 2a. 2. male spline section; Gear, 3a. 3. Female spline part Assembly stand, 41. Chuck, 42. Shaft fixing portion, 43. Assembly actuator, 45. 4. second shaft fixing part; Robot hand, 52. Rod, 52a. Spring, 53. Bracket, 53a. Gear pressing portion, 54. First gripping claws, 55. Second gripping claws 56. First sensor, 57. Second sensor

Claims (10)

A gear shaft (1) is assembled by fitting a shaft (2) having a male spline part (2a) on the outer peripheral surface and a gear (3) having a female spline part (3a) on the inner peripheral surface of the shaft hole. A device comprising a robot and a gear shaft assembly (4);
The robot hand (5)
A circular hole and a cylindrical gear, which are attached to the base (51) of the robot hand via two rods (52) provided with springs and which can be vertically moved and through which the shaft can be fitted. A bracket (53) having a pressing portion (53a);
A gripping claw (54) disposed at a lower portion of the bracket and gripping the gear while being pressed by a gear pressing portion (53a) of the bracket;
A first sensor (56) for detecting the presence or absence of the gripped gear;
A second sensor (57) for detecting assembly completion,
The gear shaft assembly base (4)
A shaft fixing portion (42) for hanging the shaft;
An assembly actuator (43) for rotating the shaft in a horizontal direction together with the shaft fixing portion (42),
The gear shaft assembling apparatus, wherein the robot and the gear shaft assembling table are controlled by the same robot controller. The gear shaft assembling apparatus according to claim 1, wherein the robot hand (5) has a second gripping claw (55) for gripping the shaft. The gear shaft assembling apparatus according to claim 1 or 2, wherein the robot is a simultaneous seven-axis control robot that controls the assembling actuator (43) with the same robot controller. The gear shaft assembling apparatus according to any one of claims 1 to 3, wherein the gear shaft assembling table (4) includes a second shaft fixing portion (45) for fixing the shaft in a suspended state. A gear (3) provided with a male spline part (2a) on the outer peripheral surface and a female spline part (3a) on the inner peripheral surface of the shaft hole using the gear shaft assembling apparatus according to claim 1. Is a gear shaft assembling method that is assembled by spline fitting,
(A) The robot grips the gear (3) while pressing the gear with the gear pressing portion (53a) of the bracket (53) provided in the robot hand (5).
(B) The robot moves the gripped gear (3), and the shaft (2) suspended from the gear shaft assembly base is fitted into the shaft hole of the gear and the gear pressing portion (53a). And unclamping at a position near the upper end of the spline of the shaft (2) and the lower end of the spline of the gear;
(C) The robot moves the robot hand (5) downward to a predetermined position and presses the unclamped gear (3) with the pressing portion (53a) of the bracket (53). Rotating the robot hand (5) in the horizontal direction about the plane center point of the circular hole of the bracket;
(D) The assembly actuator (43) included in the gear shaft assembly base (4) is configured so that the shaft is placed horizontally around the plane center point of the shaft fixing portion (42) included in the gear shaft assembly base (4). Rotating in a direction;
And when the robot detects the completion of the assembly of the gear shaft in any of the steps (B) to (D), the assembly of the gear shaft is completed in the step of detecting the completion of the assembly of the gear shaft. A gear shaft assembling method characterized by the above. The gear shaft assembling method according to claim 5, wherein the steps are in the order of (A), (B), (C), and (D). The gear shaft assembling method according to claim 5, wherein the steps are in the order of (A), (B), (D), and (C). The gear shaft assembling method according to any one of claims 5 to 7, further comprising a step (E) of causing the shaft rotated in the horizontal direction in the step (C) to double-act to a position before the rotation. The gear shaft assembling method according to any one of claims 5 to 8, wherein the robot includes a step of hanging the shaft (2) on the gear shaft assembly base (4) before the step (A). The gear shaft assembling method according to any one of claims 5 to 9, wherein the robot of the assembling apparatus is a simultaneous seven-axis control robot for controlling the assembling actuator (43) with the same robot controller.

Images