JP4446784B2 - Ball spline mechanism ball selection method - Google Patents

Description

  The present invention relates to a ball selection method for selecting a ball interposed between an outer ball groove and an inner ball groove of a ball spline mechanism.

  For example, a pulley for a continuously variable transmission (hereinafter referred to as “CVT”) extends along the axial direction on the outer peripheral surface of a shaft portion formed integrally with the shaft pulley and has a predetermined interval in the circumferential direction. A plurality of outer ball grooves that are spaced apart from each other are formed, while a plurality of inner ball grooves are formed at the same phase as the ball grooves on the shaft portion side on the inner peripheral surface of the boss portion formed integrally with the sheave pulley. A ball spline mechanism formed by fitting a plurality of balls in a spline groove formed by an outer ball groove on the shaft portion side and an inner ball groove on the boss portion side by fitting the shaft portion to the boss portion The shaft pulley and the sheave pulley can be rotated integrally and can be moved in the axial direction toward and away from each other.

  The spline groove of the ball spline mechanism used in this CVT pulley may cause variations in clearance with the ball due to processing errors of each ball groove. Must be selected and inserted into the spline groove.

  Conventionally, various methods have been proposed as a method of selecting a ball having an optimum size. As one of the methods, a measuring ball having a smaller outer diameter than that of a normal ball is prepared and a spline groove is prepared. The shaft pulley and sheave pulley are rotated and moved relatively in the forward and reverse directions, and the amount of play, which is the amount of displacement in the circumferential direction, is measured, and actual assembly is performed according to the measured amount of play. There is a ball selection method in which an outer diameter of a ball to be obtained is determined and a ball having the outer diameter is selected as an optimally sized ball (for example, see Patent Document 1).

  Also, an evaluation method for measuring the load required when the selected ball is inserted into the spline groove and determining that the ball is of an optimal size when it is within a predetermined range (for example, patent document) 2), or after the selected ball is inserted into the spline groove, the backlash is measured again, and if it is within the preset allowable range, it is judged that the ball is the optimum size. A method has been proposed (see, for example, Patent Document 3).

Japanese Patent No. 3141826 Japanese Patent No. 3059158 Japanese Patent No. 3011025

  However, in the case of the conventional ball selection method described above, the spline groove is formed by fitting the outer ball groove of the shaft portion and the inner ball groove of the boss portion at an arbitrary phase. When the play amount is measured by inserting the shaft, the shaft pulley and the sheave pulley are displaced in the axial center at a predetermined phase, and when rotating, the outer peripheral surface of the shaft portion and the inner peripheral surface of the boss portion are There is a risk of contact. And if the outer peripheral surface of a shaft part and the inner peripheral surface of a boss | hub part contact | abut, the exact backlash amount by the relationship between a ball | bowl and a groove part cannot be measured.

  Further, in each of the conventional evaluation methods described above, even when the load at the time of ball insertion is within a specified range and the backlash measured again is within an allowable range, the outer peripheral surface of the shaft portion is in contact with the inner peripheral surface of the boss portion. In such a case, it is difficult to smoothly move the sheave pulley along the axial direction of the shaft pulley, and the desired performance inherent in the CVT pulley cannot be secured. is there.

  Therefore, in manufacturing the ball spline mechanism, it is necessary to minimize the processing error of each ball groove, and precise processing accuracy and component management are required, resulting in an increase in manufacturing cost.

  In view of these problems, the present invention has been made to solve the problems of the prior art, and its purpose is to improve the prediction accuracy for predicting the optimal ball size (outer diameter). To provide a ball selection method for a spline mechanism.

The ball selection method for the ball spline mechanism according to the first aspect of the present invention that achieves the above object includes a plurality of balls arranged at predetermined intervals in the circumferential direction on the outer circumferential surface of the rotary shaft member and extending along the axial direction. An outer ball groove that is disposed on the inner peripheral surface of the outer shaft groove that is movably fitted in the axial direction of the rotary shaft member, and is disposed at a location facing the outer ball groove and along the axial direction. In the ball selection method of a ball spline mechanism having an extended inner ball groove, and a ball is interposed in a spline groove formed by the opposed outer ball groove and the inner ball groove, the outer ball groove and the The rotation shaft member and the shaft fitting insertion member are relatively rotated in a normal rotation direction and a reverse direction with a predetermined torque by interposing a measurement ball having a smaller diameter than the ball between the inner ball groove , The shaft fitting by the image processing means The members by capturing the axial direction by measuring the amount of play between the shaft fitting portion member and the rotating shaft member by the image data processing of the reverse-direction displacement position, the normal rotation direction displacement position of the insertion member fitting the shaft, the amount of play The total phase play amount measurement step in which the measurement of all phases where the outer ball groove and the inner ball groove face each other and the play amount of all phases measured in the total phase play amount measurement step are compared with each other and are the largest. The backlash amount is determined as the optimal backlash amount, and the phase having the optimal backlash amount is determined as the optimal phase, and the position of the forward direction displacement position and the reverse direction displacement position of the shaft insertion member detected by the image processing means Based on the data, the shape of the inner ball groove and the outer ball groove is represented in a coordinate system, and the optimum shape of the ball in the optimum phase is determined from the shape of the inner ball groove and the outer ball groove represented in the coordinate system. Outer diameter And the optimal ball outer diameter prediction step of predicting, and having an optimum ball selection step of selecting a ball with optimum ball outer diameter as predicted by the optimum ball OD prediction step as the optimal ball at the optimal phase.

  According to a second aspect of the present invention, in the ball selection method of the ball spline mechanism according to the first aspect, in the optimum ball selection step, the rotating shaft member and the shaft fitting member are at the optimum phase determined in the optimum ball outer diameter prediction step. And a spline groove formed by fitting a ball having an optimal ball outer diameter, measuring the sliding resistance force by relatively moving the rotating shaft member and the shaft fitting member in the axial direction, When the measured sliding resistance is within a predetermined range, a ball having the predicted optimum ball outer diameter is selected as the optimum ball in the optimum phase.

According to a third aspect of the present invention, in the ball selection method of the ball spline mechanism according to the second aspect, in the optimum ball selection step, when the measured sliding resistance is smaller than a specified lower limit value, the ball Is removed from the spline groove, a ball having a ball outer diameter larger than that of the ball is interposed in the spline groove, and if the measured sliding resistance is greater than a specified upper limit value, the ball is splined. A ball having a ball outer diameter smaller than that of the ball is removed from the groove, and the spline groove is interposed.
According to a fourth aspect of the present invention, in the ball selection method for the ball spline mechanism according to any one of the first to third aspects, in the optimum ball selection step, a reference circle having a specified diameter is set to 2 in the inner ball groove. The sum of squares of the separation distance between the center coordinate position of the reference circle when contacted at a point and the center coordinate position of the reference circle when the reference circle is contacted at two points with the outer ball groove is minimum. An optimum circle is obtained, and the diameter of the optimum circle is predicted as the optimum ball outer diameter.
According to a fifth aspect of the present invention, in the ball selection method of the ball spline mechanism according to the fourth aspect, in the optimum ball selection step, a circle passing through the center of each optimum circle is obtained from the optimum circle between the ball grooves. Calculating a deviation amount between the center of the circle and the shaft center of the shaft member, and confirming that the deviation amount is smaller than a clearance difference between the outer diameter of the shaft member and the inner diameter of the shaft fitting member. Features.

According to the first aspect of the present invention, the measuring ball having a smaller diameter than the ball is interposed between the outer ball groove and the inner ball groove so that the rotating shaft member and the shaft-inserting member are relatively rotated in a forward direction with a predetermined torque. The ball spline mechanism has a ball spline mechanism that rotates and moves in the reverse direction, images the shaft insertion member from the axial direction by the image processing means, processes the image data of the forward direction displacement position and the reverse direction displacement position of the shaft insertion member. By measuring the amount of play in all phases, when the rotary shaft member and the shaft insertion member are relatively rotated in the forward direction and the reverse direction, the outer surface of the rotary shaft member and the shaft insertion member The optimum phase determined by the relationship between the spline groove and the measurement ball without contact with the peripheral surface is found, and the normal direction displacement position and the reverse direction displacement position of the shaft insertion member detected by the image processing means at that time are found . Based on the position data, the inner ball groove and the outer Represents the shape of Lumpur groove in the coordinate system, because predicting the optimal outer diameter of the ball at the optimal phase from the shape of the outer ball groove and the ball groove inner represented by the coordinate system, an optimum outer diameter of the ball Prediction accuracy to be predicted can be improved. In addition, the processing accuracy of the outer ball groove and the inner ball groove can be relaxed as compared with the conventional case, the manufacturing of the ball spline mechanism can be facilitated, and the manufacturing cost can be reduced.

  According to the invention of claim 2, a ball having the optimum ball outer diameter predicted in the optimum ball outer diameter predicting step is interposed in the spline groove formed by fitting the rotating shaft member and the shaft fitting insertion member at the optimum phase. Whether or not the ball having the optimum ball outer diameter is the optimum ball in the optimum phase by measuring the sliding resistance force by relatively moving the rotating shaft member and the shaft fitting member in the axial direction. Can be evaluated. Therefore, it is possible to select an optimum ball that does not have backlash in the circumferential direction or has little backlash and can be moved smoothly in the axial direction.

The invention of claim 3 specifically shows the method of selecting the optimum ball in the optimum ball selection step described in claim 2, and according to this, the sliding resistance is smaller than the specified lower limit value. Is replaced with a ball having a large ball outer diameter, the sliding resistance can be increased and can be adjusted within a specified range. On the other hand, if the sliding resistance is larger than the specified upper limit value, the sliding resistance can be reduced by changing to a ball having a smaller ball outer diameter and can be adjusted within the specified range. it can. Therefore, it is possible to select an optimum ball that does not have backlash in the circumferential direction or has little backlash and can be moved smoothly in the axial direction.
The invention according to claim 4 specifically shows the optimum ball selection step according to any one of claims 1 to 3, wherein the reference ball having a specified diameter is brought into contact with the inner ball groove at two points. Find the optimum circle that minimizes the sum of squares of the distance between the center coordinate position of the reference circle and the center coordinate position of the reference circle when the reference circle is brought into contact with the outer ball groove at two points. Is estimated as the optimum ball outer diameter.
The invention according to claim 5 specifically shows the optimum ball selection step according to claim 4, wherein a circle passing through the center of each optimum circle is obtained from the optimum circle between each ball groove, and the center of the circle and the shaft member The amount of deviation from the shaft center is calculated, and it is confirmed that the amount of deviation is smaller than the clearance difference between the outer diameter of the shaft member and the inner diameter of the shaft fitting member.

  Next, a ball selection method for the ball spline mechanism according to the embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the ball selection method of the ball spline mechanism according to the embodiment of the present invention includes a total phase backlash measurement step (step S1), an optimum ball outer diameter prediction step (step S2), and an optimum ball selection step. It consists of three steps (Step S3).

  First, the configuration of the CVT pulley 1 having the ball spline mechanism V in the present embodiment will be described. The CVT pulley 1 is provided in a belt type continuously variable transmission of an automobile, and as shown in FIG. 5, a shaft pulley 2 (rotary shaft member) connected to an output shaft of the engine, and the shaft pulley 2 The shaft pulley 2 and the sheave pulley 6 can be rotated together by the ball spline mechanism V, and the sheave pulley 6 is moved relative to the shaft pulley 2 in the axial direction. It is configured to be possible.

The shaft pulley 2 has a shaft portion 3 and a pulley portion 4, and a shaft pulley ball groove (outer ball groove) extending along the axial direction at a predetermined interval in the circumferential direction on the outer peripheral surface of the shaft portion 3. ) Ho is formed. In the present embodiment, the shaft pulley ball grooves Ho1 _to # 1 to # 3 are provided at an angular interval of 120 degrees around the rotation center (see FIG. 9). . These shaft pulley ball grooves Ho1 to ₃ have a groove shape called a gothic arch shape in which two concave arcs having the same radius of curvature in the longitudinal section are opposed to each other (see FIG. 15). The pulley portion 4 has a disk shape that expands in the radial direction at the base end side position of the shaft portion 3, and is formed with a tapered pulley surface that gradually decreases in diameter as it moves toward the shaft pulley ball groove Ho side. ing.

On the other hand, the sheave pulley 6 has a boss portion 7 into which the shaft portion 3 of the shaft pulley 2 can be fitted and a disk-like pulley portion 8 that expands in the radial direction at one end portion of the boss portion 7. Sheave pulley ball grooves (inner ball grooves) Hi ₁ to ₃ are formed on the inner peripheral surface of the boss portion 7 at positions corresponding to the shaft pulley ball grooves Ho ₁ to ₃ . These sheave pulley ball grooves Hi _{1 to 3} have a concave groove shape in which the longitudinal section is called a gothic arch shape, as with the shaft pulley ball grooves Ho ₁ to ₃ (see FIG. 15). The pulley portion 8 is provided such that a tapered pulley surface that gradually decreases in diameter as it moves outward in the axial direction faces the pulley surface of the shaft pulley 2.

(Step S1: Total phase backlash measurement process)
In the total phase backlash measurement process shown in step S1 of FIG. 1, the measuring ball 9 is assembled to the CVT pulley 1 having the above-described configuration, and the shaft pulley 2 and the sheave pulley 6 are relatively rotated in the forward and reverse directions. The amount of play when measured is measured for all phases.

FIG. 2 is a flowchart for explaining a method of measuring the backlash amount of all phases. First, an operation of assembling the CVT pulley 1 by inserting the measuring balls 9 into the spline grooves H1 to ₃ of the CVT pulley 1 is performed (step S11).

In the CVT pulley 1, the shaft portion 3 is inserted into the boss portion 7, and any one phase in which the shaft pulley ball grooves Ho1 _to 3 of the shaft portion 3 and the sheave pulley ball grooves Hi1 _{to 3} of the boss portion 7 face each other. In accordance with the above, a measuring ball 9 for predicting the optimum ball outer diameter d in each of the spline grooves H ₁ to ₃ formed between the shaft pulley ball grooves Ho ₁ to ₃ and the sheave pulley ball grooves Hi _{1 to 3} is provided. It is assembled by interposing. The outer diameter d ₀ of the measuring ball 9 is smaller than the optimum ball outer diameter d (d ₀ <d), and when the sheave pulley 6 is rotated around the shaft while the shaft pulley 2 is fixed, the rotation of the measurement ball 9 is rotated. The size is set such that the play within the range preset in the direction can be generated.

  Once the CVT pulley 1 is assembled, the shaft pulley 2 and the sheave pulley 6 are relatively rotated in the forward direction and the reverse direction, and the amount of play in the phase is measured (step S12). The play amount is measured by the optimum ball outer diameter predicting device 10 shown in FIGS.

  As shown in FIGS. 6 and 7, the optimum ball outer diameter predicting device 10 includes a pulley holding unit 11, a pulley rotation urging unit 21, and an image processing unit 31. The pulley holding means 11 includes a pulley chuck 12 that holds the outer peripheral edge portion of the pulley portion 4 of the shaft pulley 2 from both sides in the axial direction on the gantry 13, and the distal end side of the shaft portion 3 of the shaft pulley 2 in the radial direction. The shaft chuck 15 is sandwiched and held from both sides, and the shaft pulley 2 can be fixed at a fixed position set in advance in a posture state in which the rotation center extends in the horizontal direction.

  The pulley rotation urging means 21 is attached along the back surface of the pulley portion 8 of the sheave pulley 6 and is integrally fixed to the sheave pulley 6 by sandwiching the outer peripheral edge portion of the pulley portion 8 from both sides in the axial direction. 22, a right rotation arm 23 projecting substantially horizontally from the biasing disk 22 toward the radially outer side, and a right rotation arm 23 from the biasing disk 22 approximately in the opposite direction. A horizontally projecting left rotation arm 24, a weight 26 attached to the lower end of a connecting rod 25 that respectively hangs down from the tip of the right rotation arm 23 and the tip of the left rotation arm 24, A cylinder mechanism 27 that is attached and moves the pair of weights 26 up and down and a control unit 28 that controls the operation of the cylinder mechanism 27 are provided.

  The control unit 28 is configured by, for example, a sequence program computer or the like, and drives the cylinder mechanism 27 by inputting a predetermined control signal to move the weight 26 up and down, and the sheave pulley 6 is rotated in the clockwise direction (forward direction) with a predetermined torque. ) And left rotation direction (reverse direction), and rotated to the right rotation displacement position (forward rotation direction displacement position) and left rotation displacement position (reverse direction displacement position) rotated by the backlash of the measuring ball 9. A control program for arranging them is incorporated in advance.

  The image processing means 31 performs image processing on the basis of the CCD camera 32 that captures the rotational movement state of the biasing disk 22 attached to the sheave pulley 6, and the image captured by the CCD camera 32, and the direction orthogonal to the axial direction Is provided with a play amount calculation processing means 33 for calculating a play amount by expanding it on a coordinate plane extending to the display, and a display monitor 34 for displaying a calculation result of the play amount calculation processing means 33, image processing data, and the like. . The CCD camera 32 is provided at a position facing the disk surface of the urging disk 22 so that a predetermined measurement / inspection point K (see FIG. 9) can be photographed over a predetermined range of the disk surface from the axial direction. Is set.

  In this embodiment, the play amount calculation processing means 33 is constituted by a PC (personal computer) installed in the gantry 13 and a software program installed in the PC. The PC is also installed with a software program (optimal ball outer diameter predicting means) for executing an optimal ball outer diameter prediction calculation process. Further, as shown in FIG. 8 which is a functional block diagram of the optimum ball outer diameter predicting device, the PC is connected to the control unit 28 of the pulley rotation urging means 21 by a communication cable 35, and can transmit and receive control signals to and from each other. It is configured to be possible.

  The setting of the CVT pulley 1 to the optimum ball outer diameter prediction device 10 having the above-described configuration is performed by an operator or the like. First, as shown in FIG. 6, the operator or the like fixes the biasing disk 22 integrally to the pulley portion 8 of the sheave pulley 6, and connects the pulley portion 4 of the shaft pulley 2 and the shaft portion 3 to the pulley of the pulley holding means 11. The right rotating arm 23 and the left rotating arm 24 are fixed on the gantry 13 with the chuck 12 and the shaft chuck 15 in a posture in which the right rotating arm 23 and the left rotating arm 24 extend in the horizontal direction.

  And it connects with the weight 26 via the connection rod 25 at the front-end | tip of the arm 23 for right rotation, and the arm 24 for left rotation, respectively. In this state, the urging force in the rotational direction is not applied to the urging disk 22, and the sheave pulley 6 is disposed at an initial position where the sheave pulley 6 can be rotated and moved in the forward rotation direction and the reverse rotation direction.

When the operator sets the CVT pulley 1 in the optimum ball outer diameter predicting device 10, the operator operates the PC to input the number of phases of the CVT pulley 1. In the present embodiment, the CVT pulley 1 has three shaft pulley ball grooves Ho ₁ to ₃ and sheave pulley ball grooves Hi ₁ to _{3 respectively} , and there are three types of phase combinations. The number “3” is entered. This phase number data is stored in the memory of the PC. Then, the start of the play amount is instructed by operating a start button (not shown).

  When the PC receives an instruction to start measurement, the image processing means 31 photographs the urging disk 22 of the sheave pulley 6 at the initial position with the CCD camera 32, and the image data of the measurement / inspection location K is taken as the initial position of the sheave pulley 6. Is stored in the memory of the PC as image data.

  Then, the control unit 28 of the pulley rotation urging means 21 performs drive control of the cylinder mechanism 27, moves the weight 26 connected to the right rotation arm 23 downward, and the weight 26 connected to the left rotation arm 24. Move up. Accordingly, the tip of the right rotation arm 23 is moved downward, the tip of the left rotation arm 24 is moved upward, and the urging disk 22 is urged in the right rotation direction with a predetermined torque.

  Accordingly, the sheave pulley 6 is urged to rotate in the clockwise direction integrally with the urging disk 22 and is arranged at the right rotational displacement position rotated by the amount of play of the measuring ball 9 as shown in FIG. . When the sheave pulley 6 is placed at the right rotational displacement position, the image processing means 31 takes a measurement / inspection point K of the biasing disk 22 with the CCD camera 32 and stores the image data in the memory of the PC.

  Next, the control unit 28 of the pulley rotation urging means 21 performs drive control of the cylinder mechanism 27, moves the weight 26 connected to the right rotation arm 23 upward, and the weight connected to the left rotation arm 24. 26 is moved downward. Accordingly, the tip of the right rotation arm 23 is moved upward, the tip of the left rotation arm 24 is moved downward, and the urging disk 22 is urged in the left rotation direction with a predetermined torque. Accordingly, the sheave pulley 6 is rotated and moved in the counterclockwise direction integrally with the urging disc 22 and is arranged at a counterclockwise displacement position (not shown) moved in the counterclockwise direction by the backlash amount of the measuring ball 9. . When the sheave pulley 6 is disposed at the left rotational displacement position, the image processing means 31 captures the measurement / inspection point K of the urging disk 22 with the CCD camera 32 and stores the image data in the memory of the PC.

  Then, the backlash amount calculation processing means 33 performs the right rotation displacement position and the left rotation displacement from the initial position of the sheave pulley 6 based on the image data of the initial position, the right rotation displacement position and the left rotation displacement position stored in the memory of the PC. As the amount of play due to movement to the position, as shown in FIG. 10, a rotation center displacement amount α, a center displacement angle γ, and a rotation angle φ are calculated. Then, the initial position image data, the right rotational displacement position image data, and the left rotational displacement position image data are overlapped to obtain a position where the surface properties of the measurement inspection location K coincide with each other, and the sheave pulley with respect to the shaft center of the shaft pulley 2 is obtained. The amount of play considering the 6 axis deviation is calculated and stored in the memory of the PC as play amount data in the phase.

  Next, it is determined whether or not the backlash has been measured for all phases of the CVT pulley 1 (step S13). If the backlash has not been measured for all phases (No in step S13), the phase is changed. (Step S14), and the amount of backlash of the phase after the change is measured.

In this embodiment, when the number of backlash data stored in the memory of the PC is less than the phase number “3” inputted in advance, a display for instructing the change of the phase is displayed by the backlash calculation processing means 33. It is shown on the monitor 34. When the display is instructed to change the phase on the display monitor 34, the operator removes the CVT pulley 1 from the optimum ball outer diameter predicting device 10, and once separates the shaft pulley 2 and the sheave pulley 6, The phases of the pulley 2 and the sheave pulley 6 are changed and reassembled, and the measuring balls 9 are inserted into the spline grooves H1 to ₃ formed by a new combination. Then, the CVT pulley 1 is attached to the optimum ball outer diameter predicting device 10 again, and the amount of play at that phase is measured. And if the play amount about all the phases which the pulley 1 for CVT has is measured (it is Yes at step S13), the play amount measurement process will be complete | finished.

(Step S2: Optimal ball outer diameter prediction step)
In the optimum ball outer diameter prediction step shown in step S2 of FIG. 1, the optimum ball outer diameter is predicted using the optimum play amount in the optimum phase. FIG. 3 is a flowchart illustrating a method for predicting the optimum ball outer diameter.

  The optimum ball outer diameter predicting means configured in the PC compares the backlash amounts for all phases of the CVT pulley 1 with each other (step S21). Then, the phase having the largest play amount among the play amounts measured in each phase is determined as the optimum phase, and the play amount in the optimum phase is determined as the optimum play amount (step S22).

  FIG. 11 to FIG. 14 show a state in which the backlash amount is measured at the first phase and the second phase in one CVT pulley 1 and a state in which the selected ball is inserted and assembled according to the result. FIG. 11 is a view showing the amount of play in the first phase, FIG. 12 is a view showing a state where a ball selected based on the amount of play measured in the first phase is assembled, and FIG. FIG. 14 is a diagram showing a state in which balls selected based on the backlash amount measured in the second phase are assembled.

In this CVT pulley 1, shaft pulley ball groove _{Ho 1 to 3,} the second ball groove Ho ₂ is the largest, the third ball grooves Ho ₃ is smallest, the first ball groove Ho ₁ is an intermediate size The sheave pulley ball grooves Hi _{1 to 3} are formed such that the third ball groove Hi ₃ is the largest, the second ball groove Hi ₂ is the smallest, and the first ball groove Hi ₁ is an intermediate size. Is formed.

And in the state which inserted and assembled | attached the measurement ball | bowl 9 as shown in FIG.11 and FIG.13, between each spline groove | channel H1-3 in the 1st phase and the measurement ball _| bowl 9, clearance A, B , C are formed, and gaps A ′, B ′, C ′ are formed between the spline grooves H ₁ to ₃ and the measurement ball 9 in the second phase.

In the case of the first phase, the sizes of the spline grooves H1 _to H3 are averaged with each other, and the gap A, the gap B, and the gap C have substantially the same size (A≈B ≒ C). Therefore, as shown in FIG. 11, when the shaft pulley 2 is fixed and the sheave pulley 6 is rotated clockwise in order to measure the backlash, the shaft pulley 2 and the sheave pulley 6 are arranged so as to be substantially coaxial. , And stops when it has been moved by a displacement amount substantially equal to the gap A. Therefore, it is possible to obtain the backlash amount A determined by the relationship between the spline grooves H ₁ to ₃ and the measurement ball 9.

When the ball selected based on the play amount A is inserted into each of the spline grooves H1 to ₃ to assemble the CVT pulley 1, the shaft pulley 2 and the sheave pulley 6 are arranged coaxially as shown in FIG. And the ball | bowl of the optimal magnitude | size which can prevent contact | abutting with the outer peripheral surface of the shaft part 3 and the internal peripheral surface of the boss | hub part 7 can be selected.

On the other hand, in the case of the second phase, the variation between the spline grooves H1 to ₃ is large, the gap A ′ and the gap C ′ are substantially equal, and the gap B ′ is extremely compared with the gap A ′ and the gap C ′. (B ′ << A′≈C ′). Therefore, as shown in FIG. 13, when the shaft pulley 2 is fixed and the sheave pulley 6 is rotated clockwise in order to measure the amount of play, the shaft stops due to the relationship between the spline grooves H ₁ to ₃ and the measuring balls 9. before than, the inner peripheral surface of the outer peripheral surface and the boss portion 7 of the shaft portion 3 is stopped in contact with such position X ₁ moiety.

Therefore, the amount of play obtained by measurement is smaller than that in the case of the first phase, and when the ball selected based on the amount of play is inserted into the spline grooves H ₁ to ₃ and the CVT pulley 1 is assembled. as shown in FIG. 14, the axis is displaced in the shaft pulley 2 and Shibupuri 6, the inner peripheral surface of the outer peripheral surface and the boss portion 7 of the shaft portion 3 abuts with X ₂ portions. Therefore, the sliding resistance force when the shaft pulley 2 and the sheave pulley 6 are relatively moved in the axial direction increases, and the shaft pulley 2 and the sheave pulley 6 cannot be moved smoothly in the axial direction. For this reason, it may be difficult to ensure a smooth shift.

  Therefore, in the present embodiment, the phase having the largest backlash amount is determined as the optimum phase from the backlash amounts for all phases of the CVT pulley 1, and the backlash amount measured at the optimum phase is optimized. The amount of play is determined.

  When the optimum ball outer diameter predicting means determines the optimum phase and the optimum play amount of the CVT pulley 1, the optimum ball outer diameter d, which is the optimum ball size in the optimum phase, is determined using the optimum play amount. Execution of the process to be predicted is started (step S23).

In the prediction process of the optimum ball outer diameter d, as a first precondition, the shaft pulley 2 and the measurement ball 9 are considered to be integrated and do not move, and this is set as a reference dimension. As a second precondition, as shown in FIG. 15, the variation of the sheave pulley ball groove Hi ₁ of the sheave pulley 6 depends on the rotation center O of the shaft pulley 2 and the center (0, A) of the measuring ball 9. Only the direction with an inclination angle of 45 ° with respect to the passing radial reference line is considered. # 1 Sheave pulley ball groove Hi ₁ Left side wall portion (forward direction side wall portion) LHi ₁ and right side wall portion (reverse direction side wall portion) RHi ₁ Each radius of curvature center coordinate position (a _L , b _L ), (a _{R 1} , b _R ) is calculated by the following equation (1).

  However, A is a known parameter, and D is a parameter for variation of the sheave pulley 6.

Next, under the first and second preconditions, as shown in FIG. 16, the curvature radius center coordinate position (a _L ′, b _L ′) of the left side wall LHi ₁ and the measurement ball 9 Assuming that the center coordinate position (0, c) and the contact point p between the left side wall portion LHi ₁ and the measurement ball 9 are collinear, the sheave pulley ball groove Hi _{1 at} the right rotational displacement position Find the coordinate position. The curvature radius center coordinate position (a _L ′, b _L ′) of the left side wall portion LHi ₁ of the sheave pulley ball groove Hi ₁ is calculated using the following equations (2) and (3).

However, the curvature radius L of the left side wall portion LHi ₁ , the radius r of the measurement ball 9 and the center coordinate position (0, c) of the measurement ball 9 are known.

By substituting Equation (1) into Equation (2) and Equation (3) and solving for D, the coordinate position of the left side wall portion LHi _{1 at} the initial position can be expressed by Equation (4) below.

The same applies to the left side wall portions LHi ₂ and LHi ₃ of the # 2 sheave pulley ball groove Hi ₂ and the # 3 sheave pulley ball groove Hi ₃ .

として表すことができる。

Can be expressed as

Next, the coordinate position of the # 1 sheave pulley ball groove Hi _{1 at} the left rotational displacement position is obtained. The curvature radius center coordinates (a _R ″, b _R ″) of the right side wall portion RHi ₁ of the sheave pulley ball groove Hi ₁ are calculated using the following formulas (7) and (8).

However, the curvature radius R of the right side wall portion RHi ₁ , the radius r of the measurement ball 9, and the center coordinate position (0, c) of the measurement ball 9 are known.

  Substituting the following formula (9) into the above formula (7) and formula (8),

By solving for D, the coordinate position of the right side wall portion RHi _{1 at} the initial position can be expressed by the following equation (10).

The same applies to the right side walls RHi ₂ and RHi ₃ of the # 2 sheave pulley ball groove Hi ₂ and the # 3 sheave pulley ball groove Hi _3.

として表すことができる。

Can be expressed as

Then, the optimal ball outer diameter d is calculated based on the left side wall portions LHi _1-3 and the right side wall portions RHi _1-3 of the # 1 to # 3 sheave pulley ball grooves Hi _1-3 . FIGS. 17 and 18 are diagrams showing the relationship between the right side wall portion RHi and the left side wall portion LHi of the sheave pulley ball groove Hi and the sheave pulley reference circle GI on a coordinate plane. First, as shown in FIG. 17, a sheave pulley reference circle GI ₁ having a specified diameter r is simultaneously brought into contact with both the right side wall portion RHi ₁ and the left side wall portion LHi ₁ of the # 1 sheave pulley ball groove Hi ₁ . The coordinate position (x ₁ , y ₁ ) of the center Q ₁ is obtained. Here, the center coordinate position Q ₁ (x ₁ , y ₁ ) of the sheave pulley reference circle GI ₁ is calculated by the following equations (13) and (14).

  However, S and T in the above equations (13) and (14) are calculated by the following equations (15) and (16).

In addition, RL of the above formula (15) is a distance between the curvature radius center coordinate positions of the right side wall portion RHi ₁ and the left side wall portion LHi ₁ as shown in FIG. 18, and is calculated by the following formula (17). The

Further, RQ = R−r and LQ = L−r. Similarly, for the # 2 sheave pulley ball groove Hi ₂ and the # 3 sheave pulley ball groove Hi ₃ , the coordinate position (x ₂ , y ₂ ) of the center Q ₂ of the sheave pulley reference circle GI and the center Q ₃ Coordinate position (x ₃ , y ₃ ) is obtained.

Next, the shaft pulley reference circle when the shaft pulley reference circle Go ₁ having the specified diameter r is simultaneously brought into contact with both the right side wall portion RHo ₁ and the left side wall portion LHo ₁ of the # 1 shaft pulley ball groove Ho _1. A central coordinate position Qo ₁ (xo ₁ , yo ₁ ) of Go ₁ is obtained (none of which is shown). The center coordinate position Qo ₁ (xo ₁ , yo ₁ ) of the shaft pulley reference circle Go ₁ is calculated by the following equations (18) and (19).

However, the center coordinate position (c _RL , d _RL ) of the shaft pulley is known from the first precondition, and S and T in the above equations (18) and (19) are the following (20), (21 ).

Then, the coordinate position of the center to _{Q 1} Shibupuri reference circle GI ₁ calculated by the above calculation equation _(x 1, _{y 1),} the right side wall portion of the shaft pulley ball groove Ho ₁ Rho ₁ and the left wall LHO ₁ by using the coordinate position of the center Qo ₁ reference circle Go ₁ for simultaneously contacting shaft pulley both in, and calculates the optimum ball outer diameter d ₁ of the spline groove H ₁ of # 1.

Here, # 1, # 2, to the respective spline grooves _{H 1 to 3} same for both ball size # 3, the optimal ball out to calculate the optimal ball outer diameter _d 1 to d ₃ of each spline grooves _{H 1 to 3} The diameter d is one (d ₁ = d ₂ = d ₃ = d), and as shown in the following formula (22), the sheave pulley reference circle GI ₁ and the shaft pulley reference circle Go of each ball groove, respectively. calculated by the least squares method the square sum S of the distance connecting the _first center Q _1, Qo ₁ with straight lines is a radius r of a circle having the smallest, and the radius r 2 times the length of the optimal ball outer diameter d To do.

  Where n = 1

Then, a coaxiality between the shaft pulley 2 and Shibupuri 6 in the case of interposed balls with optimal ball outer diameter d to the spline grooves H _{1 to 3} of # 1 to # 3. The concentricity is obtained by the amount of deviation between the center of the circle passing through the center of each ball interposed in each of the spline grooves H ₁ to 3 of # 1 to # 3 and the axis center of the shaft pulley 2. When the coaxiality is smaller than the clearance difference between the inner diameter of the boss portion 7 of the sheave pulley 6 and the outer diameter of the shaft portion 3 of the shaft pulley 2, it is predicted as the optimum ball outer diameter d, and the optimum ball outer diameter is predicted. It is stored in the memory of the means and displayed on the display monitor 34.

(Step S3: Optimal ball selection process)
In the optimum ball selection step shown in step S3 of FIG. 1, it is evaluated whether or not the optimum ball outer diameter d predicted in the optimum ball outer diameter prediction step in step S2 is appropriate. A ball having a diameter d is selected, and if not appropriate, a process of selecting a ball having a ball outer diameter different from the optimum ball outer diameter d is performed.

FIG. 4 is a flowchart for explaining the optimum ball selection method. First, the shaft pulley 2 and the sheave pulley 6 of the CVT pulley 1 are combined in an optimal phase, and a ball having the optimal ball outer diameter d is inserted into the spline grooves H1 to ₃ to be assembled (step S31).

  Then, the sheave pulley 6 is moved in the axial direction with respect to the shaft pulley 2, and the sliding resistance force is measured (step S32). For example, as shown in FIG. 19, the sliding resistance force is measured by supporting the shaft pulley 2 in a posture in which the shaft portion 3 of the shaft pulley 2 extends in the vertical direction in a state where the CVT pulley 1 is assembled. Measured by moving 6 in the axial direction.

  Then, it is determined whether or not the measured sliding resistance is within the range of the predetermined value set in advance (step S33). If it is within the range of the predetermined value (Yes in step S33), the prediction is made. It is evaluated that the optimum ball outer diameter d is appropriate. Therefore, the ball having the optimum ball outer diameter d is selected as the optimum ball in the optimum phase.

  On the other hand, when it is out of the range of the specified value (No in step S33), the following operation is performed so that the sliding resistance is within the range of the specified value. First, it is determined whether the measured sliding resistance is larger or smaller than the specified value range. Here, when the sliding resistance is larger than the prescribed upper limit value, a ball having an outer diameter that is one step smaller than the optimum ball outer diameter d is selected. When the sliding resistance force is smaller than the prescribed lower limit value, the optimum ball outer diameter is selected. A ball having an outer diameter one step larger than d is selected.

Then, the selected ball is replaced with a ball inserted in the spline grooves H ₁ to ₃ of the CVT pulley 1 (step S35), and the sheave pulley 6 is moved in the axial direction again to measure the sliding resistance force. (Step S32). Then, the above work (steps S32 to S35) is repeated until the sliding resistance is within the specified value range. Then, the routine ends when the sliding resistance force falls within the specified value range and the evaluation is made that the ball outer diameter of the changed ball is appropriate.

FIG. 20 is a graph showing the relationship between the insertion load when the ball is inserted into the spline grooves H ₁ to ₃ and the sliding resistance force. According to this graph, when the optimum phase is selected (when optimum), the contact between the outer peripheral surface of the shaft portion 3 and the inner peripheral surface of the boss portion 7 is suppressed, and sliding occurs as the ball insertion load increases. The resistance also increases, and there is a correlation between the ball insertion load and the sliding resistance.

On the other hand, when the optimum phase is not selected (when not optimal), the outer peripheral surface of the shaft portion 3 and the inner peripheral surface of the boss portion 7 may come into contact with each other. The dynamic resistance increases greatly, and there is no correlation with the ball insertion load. Therefore, even when the ball insertion load into the spline grooves H1 to ₃ is within the specified range, it can be accurately evaluated that the ball is inappropriate by measuring the sliding resistance force.

FIG. 21 is a graph showing the relationship between the amount of play after the ball is inserted into the spline grooves H ₁ to ₃ and the sliding resistance. According to this graph, when the optimum phase is selected (when optimum), the contact between the outer peripheral surface of the shaft portion 3 and the inner peripheral surface of the boss portion 7 is suppressed, and the sliding resistance increases as the backlash increases. The force decreases, and there is a correlation between the play amount and the sliding resistance force.

  On the other hand, when the optimum phase is not selected (when not optimal), the outer peripheral surface of the shaft portion 3 and the inner peripheral surface of the boss portion 7 may come into contact with each other. The dynamic resistance increases greatly, and there is no correlation with the amount of play. Therefore, even if the amount of play after assembly is within the allowable range, it can be accurately evaluated that the ball is inappropriate by measuring the sliding resistance force.

  According to the ball selection method of the ball spline mechanism V described above, the play amount is measured for all phases in which the shaft pulley ball groove Ho and the sheave pulley ball groove Hi face each other, and the largest play amount among all phases is optimized. In addition to determining the amount of play, the phase having the optimum amount of play is determined as the optimum phase, and the optimum outer diameter of the ball in the optimum phase is predicted using the amount of optimum play, so that the shaft pulley 2 and the sheave pulley 6 are In particular, when rotating in the forward and reverse directions, contact between the outer peripheral surface of the shaft portion 3 and the inner peripheral surface of the boss portion 7 is avoided, and the relationship between the spline groove H and the measuring ball 9 is avoided. The optimum phase determined can be found, and the accuracy of prediction of the optimum ball outer diameter can be improved by making the amount of play at that time the optimum amount of play. In addition, the processing accuracy of the outer ball groove and the inner ball groove can be relaxed as compared with the conventional case, the manufacturing of the ball spline mechanism can be facilitated, and the manufacturing cost can be reduced.

  Further, the spline groove H formed by fitting the shaft portion 3 of the shaft pulley 2 and the boss portion 7 of the sheave pulley 6 at the optimum phase has the optimum ball outer diameter d predicted in the optimum ball outer diameter predicting step in step S2. By interposing a ball and moving the shaft pulley 2 and the sheave pulley 6 relatively in the axial direction and measuring the sliding resistance force, the ball having the optimum ball outer diameter d is the optimum ball in the optimum phase. It can be evaluated whether or not there is.

  When the sliding resistance is smaller than the specified lower limit value, the sliding resistance can be increased by replacing the ball with a ball having an outer diameter larger than the optimum ball outer diameter d. Can be adjusted within the range of values.

  On the other hand, when the sliding resistance is larger than the specified upper limit value, the sliding resistance can be reduced by replacing with a ball having a ball outer diameter smaller than the optimum ball outer diameter d. Can be adjusted within the range. Therefore, it is possible to select an optimum ball that does not have backlash in the circumferential direction or has little backlash and can be moved smoothly in the axial direction.

In addition, this invention is not limited to the above-mentioned embodiment, A various change is possible in the range which does not deviate from the meaning of this invention. For example, in the above-described embodiment, the case of the three spline grooves H1 to ₃ has been described as an example, but may be two or four or more. In the above-described embodiment, the case where the shaft pulley 2 is fixed and the sheave pulley 6 is rotationally biased is described as an example. However, the sheave pulley 6 may be fixed and the shaft pulley 2 may be rotationally biased. Both the shaft pulley 2 and the sheave pulley 6 may be relatively urged to rotate in the forward and reverse directions. Further, the present invention is not limited to the ball spline mechanism of the CVT pulley 1, and the present invention can be applied to various ball spline mechanisms.

It is a flowchart which shows the ball | bowl selection method of the ball spline mechanism in this Embodiment. Similarly, it is a flowchart explaining the measuring method of the play amount of all phases. Similarly, it is a flowchart for explaining a method for predicting an optimum ball outer diameter. Similarly, it is a flowchart explaining an optimal ball selection method. Similarly, it is the schematic explaining the structure of the pulley for CVT. Similarly, it is a front view of the optimal ball outer diameter predicting device. Similarly, it is a side view of the optimum ball outer diameter predicting device. Similarly, it is a functional block diagram of an optimal ball outer diameter predicting device. Similarly, it is explanatory drawing which shows the state by which the sheave pulley is arrange | positioned in the clockwise rotation displacement position. Similarly, it is explanatory drawing which displayed the right rotation displacement position as a coordinate. Similarly, it is a figure which shows the play amount in a 1st phase. Similarly, it is a figure which shows the state which assembled | attached the ball | bowl selected based on the play amount measured in the 1st phase. Similarly, it is a figure which shows the play amount in a 2nd phase. Similarly, it is a figure which shows the state which assembled | attached the ball | bowl selected based on the play amount measured by the 2nd phase. Similarly, it is explanatory drawing which displayed the shape of the sheave pulley ball groove in the initial position as coordinates. Similarly, it is explanatory drawing which shows the curvature-radius center coordinate position of the sheave pulley ball groove in the clockwise rotation displacement position. Similarly, it is the figure which carried out the coordinate display of the relationship between the right side wall part and left side wall part of a sheave pulley ball groove | channel, and the reference | standard circle for sheave pulleys. Similarly, it is the figure which carried out the coordinate display of the relationship between the right side wall part and left side wall part of a sheave pulley ball groove | channel, and the reference | standard circle for sheave pulleys. Similarly, it is a figure explaining the method of measuring sliding resistance force. Similarly, it is the graph which showed the relationship between the insertion load at the time of inserting a ball | bowl in a spline groove | channel, and sliding resistance. Similarly, it is a graph showing the relationship between the amount of play after the ball is inserted into the spline groove and the sliding resistance.

Explanation of symbols

1 CVT pulley 2 Shaft pulley (rotary shaft member)
3 Shaft part 6 Sheave pulley (shaft fitting member)
7 Boss 10 Optimal ball outer diameter prediction device V Ball spline mechanism H Spline groove Hi Sheave pulley ball groove Ho Shaft pulley ball groove d Optimal ball outer diameter

Claims (5)

A plurality of outer ball grooves arranged on the outer peripheral surface of the rotating shaft member at predetermined intervals in the circumferential direction and extending along the axial direction, and a shaft that is externally fitted so as to be movable in the axial direction of the rotating shaft member An inner ball groove that is disposed at a location facing the outer ball groove on the inner peripheral surface of the fitting member and extends along the axial direction, the opposed outer ball groove and the inner ball groove, In the ball selection method of the ball spline mechanism in which the ball is interposed in the spline groove formed by
A measuring ball having a smaller diameter than the ball is interposed between the outer ball groove and the inner ball groove, and the rotating shaft member and the shaft fitting member are relatively rotated in a forward direction and a reverse direction with a predetermined torque. The shaft insertion member is photographed from the axial direction by the image processing means, and the rotation shaft member and the shaft are processed by image data processing of the forward direction displacement position and the reverse direction displacement position of the shaft insertion member. Measuring the amount of play with the fitting member, and measuring the amount of play for all phases where the outer ball groove and the inner ball groove face each other,
該全with determining the phase amount of play backlash amounts of all the phases measured by the measuring step with the largest amount of play in comparison to each other as the optimum amount of play determines the phase having the optimum amount of play as the optimum phase, the image Based on the position data of the forward direction displacement position and the reverse direction displacement position of the shaft insertion member detected by the processing means, the shape of the inner ball groove and the outer ball groove is expressed in a coordinate system, and expressed in the coordinate system. An optimum ball outer diameter predicting step for predicting an optimum outer diameter of the ball in the optimum phase from the shapes of the inner ball groove and the outer ball groove ,
A ball selection method for a ball spline mechanism, comprising: an optimum ball selection step of selecting a ball having an optimum ball outer diameter predicted by the optimum ball outer diameter prediction step as an optimum ball in an optimum phase. In the optimum ball selection step, the predicted optimum ball outer diameter is set in the spline groove formed by fitting the rotary shaft member and the shaft fitting insertion member at the optimum phase determined in the optimum ball outer diameter prediction step. Interposing a ball having, measuring the sliding resistance force by relatively moving the rotary shaft member and the shaft fitting member in the axial direction,
2. The ball having the predicted optimum ball outer diameter is selected as the optimum ball in the optimum phase when the measured sliding resistance is within a predetermined value range set in advance. A ball selection method for the ball spline mechanism described in 1. In the optimum ball selection step,
When the measured sliding resistance is smaller than a specified lower limit, the ball is removed from the spline groove, and a ball having a ball outer diameter larger than the ball is interposed in the spline groove,
When the measured sliding resistance is larger than a specified upper limit value, the ball is removed from the spline groove, and a ball having a ball outer diameter smaller than the ball is interposed in the spline groove. A ball selection method for a ball spline mechanism according to claim 2. In the optimum ball selection step,
The center coordinate position of the reference circle when the reference circle having a specified diameter is brought into contact with the inner ball groove at two points, and the center of the reference circle when the reference circle is brought into contact with the outer ball groove at two points The optimal circle that minimizes the sum of squares of the distance from the coordinate position is obtained, and the diameter of the optimal circle is predicted as the optimal ball outer diameter. Ball selection method for ball spline mechanism. In the optimum ball selection step,
Obtain a circle passing through the center of each optimum circle from the optimum circle between each ball groove, calculate the amount of deviation between the center of the circle and the axis center of the shaft member, the amount of deviation is the outer diameter of the shaft member and the 5. The ball selection method for a ball spline mechanism according to claim 4, wherein it is confirmed that the clearance difference is smaller than a clearance difference from an inner diameter of the shaft fitting member.

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