JP2000027975A - Manufacturing device for ball holder of differential gear, and its manufacture using the device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recess device and method to simply and rapidly form a recess curve part in the inner wall of the guide hole of a ball holder. SOLUTION: This manufacturing device for the ball holder of a differential gear having a plurality of guide holes radially holding a ball and formed at equal intervals in a peripheral direction comprises a ball for rolling placed in the guide hole of a ball holder formed with squeeze previously remaining; a pair of discs 1 and 2 for rolling having guide grooves 11 and 21 formed in an opposite surface and rollingly holding and guiding in a rolling manner the ball for rolling; and a means to hold a pair of the discs 1 and 2 for rolling on both sides of the ball holder 5 with the ball for rolling placed in the guide hole. Through relative rotation between a pair of the discs 1 and 2 for rolling, the ball for rolling is forcibly moved along the inner wall of the guide hole, and a recess curve part corresponding to a ball for rolling is rolled on the inner wall surface of the guide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention enables a difference in rotation between left and right drive wheels and front and rear drive shafts of an automobile, and generates a differential limiting torque when one of the drive wheels or the drive shaft idles. The present invention relates to an apparatus and a method for manufacturing a ball holder for use in a differential device capable of increasing a driving force.

[0002]

2. Description of the Related Art An automobile differential device is a device that enables a difference in rotation between left and right drive wheels and a difference in rotation between front and rear drive wheels when a vehicle curves (in the case of a four-wheel drive vehicle). Conventionally, as a differential device for an automobile having such a function, a pinion gear is interposed between a pair of bevel gears connected to an output shaft, and when a rotational force is applied to the shaft of the pinion gear from the outside, the differential is obtained. 2. Description of the Related Art Rotation of a pinion gear at the time of operation enables a difference in rotation between output shafts is widely used.

However, when one of the driving wheels falls into snow or sand, or falls into a groove or the like, one of the wheels runs idle due to the differential and the entire driving force is lost, so that it is impossible to escape. Many. Also, in the case of a curve, when the load on the inner wheel is extremely reduced, the wheel may spin and the driving force for traveling at a high speed on the curve may be lost.

[0004] As a differential device which has solved such a problem, there has been proposed a differential device having, for example, a clutch disk crimping type differential limiting mechanism. This is because a preload is applied to the clutch disc in order to obtain a driving force even when one of the driving wheels is not in contact with the ground, so that each driving wheel is restrained even when the driving force is not applied from the engine side, There was a difficulty in combination with a device that requires independence in rotation of each wheel, such as an anti-lock brake system.

[0005] A differential having a viscous coupling type torque-sensitive differential limiting mechanism has also been proposed and used. The viscous coupling transmits torque using the shear resistance of a viscous fluid (such as silicon oil), and can provide a smooth differential limiting effect according to the rotation difference of the drive wheels. However, since the initial resistance is given by the viscous fluid, there is still a problem that each driving wheel is restricted.

In view of such circumstances, there has been proposed a differential device which is smaller than the differential device and has a differential limiting function without adding a special mechanism (Japanese Patent Laid-Open No. 8-170705).
issue). This differential gear is (a) a pair of rotating bodies fixed to driving wheels and axially opposed to each other and arranged coaxially. (B) a plurality of radially extending guide grooves, which are arranged between a pair of rotators and have a circumferentially continuous groove that is meandering so as to fluctuate; And (c) a ball that is rolled along a circumferential continuous groove of a pair of rotating bodies facing each other and is accommodated in each guide groove so as to be freely reciprocated one by one in a radial direction. (d) A case body for rotatably housing the rotating body and fixedly for housing the ball holder, and (e) a thrust washer arranged to be in contact with the outer surface of each rotating body. The ball reciprocates in the guide groove in the radial direction when moving in the continuous groove in the circumferential direction, and the driving force from the engine side is transmitted to each drive wheel via each rotating body. In addition, when a rotational difference occurs in the drive wheels, differential is enabled. When one of the drive wheels idles, a thrust force generated on the rotating body connected to the driving wheel generates a sliding frictional force between the outer surface of the rotating body and the thrust washer, thereby reducing the differential limiting effect. can get.

FIG. 9 shows an example of a differential device disclosed in Japanese Patent Application Laid-Open No. Hei 8-170705, FIG. 10 is an exploded sectional view thereof, and FIG. 11 is a diagram showing a meandering continuous groove of a pair of disk plates, a guide hole of a ball holder, and FIG. 12 is an exploded front view showing a relationship between balls, and FIG. 12 is a view showing a state where the disc plate, the ball holder, and the balls shown in FIG. 11 are combined.

As shown in FIG. 9, a differential device disclosed in Japanese Patent Application Laid-Open No. Hei 8-170705 has an open end at one end and a coaxial annular protrusion at the other end.
A case 10 having an opening 101 having the same size as the open end of the case 10 and an annular projection coaxial with the other end.
201, a pair of disk plates 3 and 4 coaxially opposed to each other, and a ball holder 5 disposed between the pair of disk plates 3 and 4.
And a plurality of balls 6 rotatably held by a ball holder 5 and a pair of thrust washers 7, 8 located outside the disk plates 3, 4.

(1) Case The coaxial annular projection 101 of the case 10 functions as a bearing for rotatably supporting one disk plate 3.
A groove 102 is formed on the inner wall of the case 10 so as to engage with the outer peripheral projection 52 of the ball holder 5. The engagement between the groove 102 and the outer peripheral projection 52 locks the ball holder 5 so as not to rotate. ing. A plurality of holes 104 and 204 are provided in the side walls of the case 10 and the case cover 20, so that lubricating oil can flow into the case. The flanges 105 and 205 provided at the open end 10a of the case 10 and the open end 20a of the case cover 20 have a large number of holes 105 for bolt insertion.
a, 205a are provided, and the case 10 and the case cover 20 are fixed by bolts (not shown) penetrating the both holes 105a, 205a.

(2) Case Cover The case cover 20 has a shallow dish shape, and its coaxial annular projection 201 acts as a bearing for rotatably supporting the other disk plate 4. A plurality of holes 204 for lubricating oil inflow are provided in the side wall of the case cover 20.
The flange 205 provided at the open end of the case cover 20 has a number of holes at positions corresponding to the holes 105a of the case 10.
The case 10 and the case cover are provided with bolts (not shown) penetrating both holes 105a and 205a.
20 is fixed.

(3) Disk plate As shown in FIG. 11, circumferentially continuous grooves 31, 41 meandering in such a manner that the radial position fluctuates at regular intervals on the opposing surfaces of the disk plates 3, 4. Are formed. The meandering continuous grooves of the disk plates 3 and 4 extend in the same direction in the reverse rotation direction. Each of the meandering continuous grooves 31 and 41 has an arc-shaped cross section so that the ball 6 can rollably engage (see FIG. 10). At the other end of each of the disc plates 3 and 4, there are provided annular projections 32 and 42 for connecting a drive shaft (not shown) on the vehicle side. Further, screw grooves 32a, 42a for fixing the drive shaft are provided on the inner surfaces of the annular projections 32, 42.

(4) Ball Holder The ball holder 5 has a large number of elongated guide holes 51 having a width enough to receive the ball 6 and allowing the ball 6 to reciprocate in the radial direction. . The radial range of the guide hole 51 that defines the range of reciprocation of the ball 6 is defined by a radial upper limit position (a position farthest from the center) and a radial lower limit position (a position closest to the center) of each of the meandering continuous grooves 31 and 41. ) And the range.

(5) Thrust washers Thrust washers 7 and 8 are arranged between case 10 and disk plate 3 and between case cover 20 and disk plate 4, respectively.
, And a frictional force is generated on the sliding surface.

The operation of the differential will be described with reference to FIGS. FIG. 13 is an enlarged view of one unit section of the meandering continuous groove 31 of the disk plate 3, and FIG. 14 is a radial distance R (the center of the disk plate 3 and the meandering continuous groove 31) at the rotation angle θ of the meandering continuous groove 31. Distance). The meandering continuous groove of the other disk plate 4, the ball 6, and the ball holder 5
The relationship with the guide hole 51 is exactly the same.

The meandering continuous groove 31 moves the ball 6 from the radially outer side to the inner side of the disk plate 3, and moves the ball 6 from the radially inner side to the outer side of the disk plate 3. A plurality of unit sections consisting of a second guide section 31b and a third guide section 31c for keeping the ball 6 at a constant position in the radial direction of the disk plate 3 are continuous in the circumferential direction. In the case of the embodiment shown in FIGS. 12 to 14, the rotation angle θ of each unit section is 72 °, and there are five unit sections in one round.

Similarly, the other disk plate 4 has a first guide section 41a, a second guide section 41b for moving the ball 6 from the radially inner side to the outer side of the disk plate 4, and a ball 6 of the disk plate 4. A plurality of unit sections including the third guide section 41c maintained at a constant position in the radial direction are continuous in the circumferential direction.

Since the meandering continuous groove 31 of the disk plate 3 and the meandering continuous groove 41 of the disk plate 4 are in a mirror image relationship with respect to a radius passing through the end of each unit section (eg, a radius OP in FIG. 11), the ball 6 It follows the same trajectory in the reverse rotation direction. The state where both disc plates 3 and 4 are combined with the ball holder 5 is as shown in FIG. Therefore, when the ball 6 moves in the meandering continuous groove 31 of the disk plate 3 in the direction of arrow R (clockwise direction), it simultaneously moves in the meandering continuous groove 41 of the disk plate 4 in the direction of arrow L (counterclockwise direction). It moves along exactly the same trajectory.

Therefore, if one of the disk plates 3 is rotated with the ball holder 5 fixed, the other disk plate 4 rotates in the opposite direction at the same speed. In this case, when the ball 6 moves in the meandering continuous grooves 31 and 41 by a rotation angle of 72 ° (that is, when it moves in the unit section), the ball 6 reciprocates once in the guide hole 51 of the ball holder 5 in the radial direction.

The shape of the two meandering continuous grooves 31 and 41 and the movement of the ball 6 will be examined in more detail. When the ball 6 is in the radial reversal position (the position where the radial distance from the center of the disk plate 3 changes from increasing to decreasing or decreasing to increasing) and in the third guide section 31c, the ball 6 and the meandering continuous groove 31 No force is transmitted between them, but in other sections, the force is transmitted to the cylindrical inner wall of the meandering continuous groove 31. When the meandering shape of the meandering continuous groove 31 satisfies the conditions of a ≦ a ′, b ≧ b ′, c ≦ c ′, and d = d ′, 2 in the sections 31a and 31b
When any one of the balls 6 is at a position where power is not transmitted, the other ball 6 is always at a position where power is transmitted.

Sections a, e, f, 31 in the meandering continuous groove 31
In the section excluding c, g and h, the ball 6 meanders so that the axial component (thrust force) of the ball 6 with respect to the disk plate 3 changes in proportion to the magnitude of the rotational torque applied to the case 10. The angle of contact with the continuous groove 31 changes. Therefore, the differential limiting torque due to the friction between the thrust washers 7 and 8 is proportional to the rotation torque applied to the case l. The above theory can be applied as it is even when the rotation angle of the unit section of the meandering continuous groove 31 is other than 72 °.

[0021]

FIG. 15 shows a ball holder 5.
The cross-sectional shape of an intermediate portion of the guide hole 51 provided in the figure is exaggerated. The inner wall of the guide hole 51 has a radius R + of the ball 6
Concave curved portions 51d, 51d 'having a radius of 0.00 to 2.00 mm are formed, and there are slight flat portions 51e, 51e' on both sides of the concave curved portions 51d, 51d '.

The bi-concave curved surface portion 51 of the ball 6 and the guide hole 51
Since there is a slight clearance between d and 51d ', the ball 6 can move freely in the guide hole 51. With such a shape, the ball 6 held in each guide hole 51 of the ball holder 5 transmits torque between the case 10 and the two disk plates 3 and 4 without being shaken even during high-speed rotation. be able to.

The concave curved surface portion 51d of the inner wall surface of the guide hole 51,
Since 51d 'cannot be formed simultaneously with the formation of the guide hole 51, it is conventionally processed by a cutting method after the formation of the wall surface. Normally, after a guide hole with a vertical wall is machined with a tool such as a punch or an end mill as a primary machining, a secondary machining is performed with a special end mill 61 having an arc-shaped cutting edge 62 with a radius R on the side as shown in FIG. Was doing.

However, the special end mill is not only expensive, but also has a higher regrinding cost than ordinary tools, and has a smaller number of times of regrinding than ordinary tools, and has a shorter life. Further, since it is difficult to simultaneously process about 10 guide holes on the ball holder 5, there is a problem that the processing time is long, and a method that can easily process the guide holes is demanded.

Accordingly, an object of the present invention is to provide an apparatus capable of processing a concave wall surface of a ball holder in a simple and inexpensive manner in a short time and a manufacturing method using the same.

[0026]

As a result of intensive studies in view of the above-mentioned problems, the present inventors have found that a pair of rolling discs having a guide groove for engaging a ball on the disc surface is used to form a punch or a roll. With the rolling balls placed in the guide holes of the ball holder formed by primary processing with an end mill or the like, sandwiched between a pair of rolling disks from both sides thereof, and both rolling disks are rotated relatively, It has been found that if the rolling ball is forcibly moved in the guide hole, a concave curved surface portion can be rolled on the inner wall surface of the guide hole by the pressure of the rolling ball, and the present invention has been completed.

That is, the apparatus of the present invention for manufacturing a ball holder for a differential gear having a plurality of guide holes for holding a ball in the radial direction at equal intervals in the circumferential direction has the following advantages. A rolling ball to be inserted into the guide hole of the formed ball holder, and (2) a pair of rolling discs provided with guide grooves for holding and guiding the rolling ball so as to be able to roll on the opposing surface. And (3) means for holding a pair of rolling discs on both sides of the ball holder with the rolling balls inserted in the guide holes and relatively rotating the pair of rolling discs, and Due to the relative rotation of the forming disc, the rolling ball is forcibly moved along the inner wall of the guide hole, so that the concave curved surface portion corresponding to the rolling ball is formed on the inner wall surface of the guide hole. It is rolled.

Further, the method of the present invention for manufacturing a ball holder for a differential gear having a plurality of guide holes for holding the ball in the radial direction at equal intervals in the circumferential direction includes the steps of (a) crushing the ball holder in advance. To form a guide hole,
(b) A pair of rolling discs provided with guide grooves for holding and guiding the rolling balls rotatably on opposing surfaces, and the rolling balls in the guide grooves of the ball holder. In the inserted state, coaxially sandwiched from both sides, (c) by rotating a pair of rolling discs relatively, forcibly moving the rolling balls along the inner wall of the guide hole, A concave curved surface portion corresponding to the rolling ball is rolled on the inner wall surface of the guide hole.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The differential device to which the present invention is applied is the same as that disclosed in Japanese Patent Application Laid-Open No. Hei 8-170705. ) Will be described in detail.

[1] Ball Holder Manufacturing Apparatus The ball holder manufacturing apparatus of the present invention includes a rolling ball 9 to be inserted into the guide hole 51 of the ball holder 5 shown in FIG. , A pair of rolling disks 1, 2
(Not shown) for relatively rotatably holding the motor. FIG. 2 (a) shows the facing surfaces of the rolling disks 1 and 2
, (B) are provided.

The discs 1 and 2 are coaxially placed on both sides of the ball holder 5 in which the rolling balls 9 are inserted into the guide holes 51 with the guide groove surfaces facing each other. The ball 9 is held. When the rolling disks 1 and 2 are relatively rotated in this state, the rolling balls 9 are forcibly reciprocated in the guide holes 51. As will be described later, since the width of the inner wall flat portions 52e, 52e of the guide hole 51 is slightly smaller than the diameter of the rolling ball 9, the rolling of the rolling ball 9 causes the inner wall flat surface of the guide hole 51 to be rolled. A concave curved surface portion corresponding to the manufacturing ball 9 is formed. For this reason, the material of the rolling ball 9 and the rolling disk 1 needs to be sufficiently harder than the ball holder 5, and the rolling disk 1 has at least the same hardness as the rolling ball 9. Is preferred.

In order to rotate a pair of rolling disks relatively, (i) rotating both disks in the opposite direction with the same force, and (ii) fixing one disk and fixing the other disk It may be rotated. In any case, the shapes of the guide grooves formed on the opposing surfaces of the two rolling disks are not different. Therefore, the following case (ii) will be described in detail, but the present invention is not limited thereto.

(1) Fixed disk A fixed rolling disk (hereinafter simply referred to as “fixed disk”).
A guide groove 11 for holding and guiding the rolling ball 9 is provided on the opposing surface of the roller 1, and a projection 12 for fixing to a rolling device (not shown) is provided at the other end. Is provided.

In the example shown in FIG. 2A, a plurality of guide grooves 11 are provided on the opposing surface 13 at equal intervals in the circumferential direction. It is inclined to one side on the left. The number of the guide grooves 11 is the same as the number of the guide holes 51 of the ball holder 5. The shape of the groove 11 is a straight line or a smooth curved line. In the present invention, the guide groove 11
Is not particularly limited, and may be various curves such as an involute curve and an arc. An involute curve is preferable because the pressure can be effectively applied to the rolling ball 9. Each guide groove 11 always intersects the corresponding guide hole 51.

In the example shown in FIG. 2B, the guide groove 11 is a circumferentially continuous groove meandering in such a manner that its position in the radial direction fluctuates at a constant period, and extends from the outside in the radial direction to the inside. The section and the section extending from the radially inner side to the outer side are repeated. The guide groove 11 always crosses the guide hole 51. The guide groove 11 shown in FIG. 2B may be the same as the meandering continuous grooves 31 and 41 of the disk plates 3 and 4 of the differential device.

FIG. 3 is a cross-sectional view of the guide groove 11 perpendicular to the cutting line direction. The cross-sectional shape of the groove 11 is usually an arc, preferably an arc having substantially the same radius as the rolling ball 9. Assuming that the thickness of the ball holder 5 is x and the diameter of the rolling ball 9 is D, the depth y of the groove 11 must be smaller than (Dx) / 2. If the depth y of the groove 11 is not less than (Dx) / 2, as shown in FIG.
When combined with the ball holder 5, the rolling disks 1 and 2 come into contact with the hole holder 5. The depth of the guide groove 11 depends on the required accuracy of the ball holder 5, but is (D−x) /2−0.01 mm to (D−x) /2−0.1
It is preferably mm. Further, in the range where the rolling ball 9 is rolled, a swell can be formed in the thrust direction of the edge of the guide hole 51, and the swell amount increases in proportion to the crushed amount of the guide hole. Remove the bulge.

FIG. 4 shows the positional relationship between the guide 11 groove and the guide hole 51 when the fixed disk 1 provided with the guide groove 11 shown in FIG. 2A and the ball holder 5 are coaxially assembled. Show. The rolling ball 9 is held in a radially enlarged portion 51 a at the radially inner end of the guide hole 51.

(2) Rotating Disk A guide groove 21 having the same cross-sectional shape and dimensions as the fixed disk 1 is also provided on the opposite surface of the rotatable rolling disk (hereinafter referred to as “rotating disk”) 2. The other end is provided with a projection 22 for connecting to a member for rotatably holding the rotating disk 2.

The shape of the guide groove 21 may be the same as that of the fixed disk 1 shown in FIGS. 2 (a) and 2 (b). FIG. 5 shows the positional relationship between the guide grooves 11 and 21 when the pair of disks 1 and 2 are opposed to each other. When the disks 1 and 2 face each other, the guide groove 11 of the fixed disk 1 intersects the guide groove 21 of the rotating disk 2. The rolling ball 9 is located at the intersection of the two guide grooves 11 and 21. When the rotating disk 2 is slowly rotated clockwise, the intersection of the guide groove 11 and the guide groove 21 gradually moves in the outer peripheral direction. The rolled ball 9 held at the intersection of the guide grooves 11 and 21 is forcibly moved from the center side to the outer side, and moves radially outward in the guide hole 51 of the ball holder 5.

(3) Rolling Ball The diameter of the rolling ball 9 is determined by the guide hole of the ball holder 5.
Determined according to the width of the 51 flat part. The diameter of the rolling ball 9 is preferably the width of the flat portion of the guide hole 51 + 0 mm to 0.1 mm, and particularly preferably the width of the flat portion + 0.02 to 0.1 mm.

When rolling is performed a plurality of times, a plurality of types of rolling balls having different diameters may be used. In that case,
First, it is preferable that rolling is performed using a rolling ball having a small diameter, and then finish rolling is performed using a rolling ball having a large diameter.

The rolling ball 9 is made of a material harder than the ball holder 5 in order to form a concave curved surface on the inner wall surface of the guide hole 51 of the hole holder 5. Examples of such a material include bearing steel, heat-resistant steel, high-speed steel, carbide, and ceramic.

(4) Primary Processing Ball Holder In the primary processing of the ball holder, a guide hole 51 having a substantially flat and vertical inner wall is formed by an end mill or the like.
As shown in FIG. 6, the guide hole 51 obtained by the primary processing has a radially enlarged portion (a circular hole portion) 51a for inserting the rolling ball 9 at one end in the radial direction, and a hole extending linearly in the radial direction. Department
Preferably, it is a combination with 52b. In the example shown in FIG. 6, the circular hole 51a is located at the radial inner end of the ball holder 5, but may be provided at the radial outer end or both ends. However, as shown in FIG. 7, a projection 51c is provided on one side of the circular hole 51a so that the rolling ball 9 inserted in the circular hole 51a of the guide hole 51 does not fall.

Since the width E of the radial hole 51b of the guide hole 51 is the same as the interval between the flat portions 52e, 52e, it is smaller than the diameter of the ball 6 by the crushing margin. The size of the crushing allowance is determined by the size of the rolling ball 9, the number of rolling balls used at one time, the number of rolling steps, the rotational torque during rolling, and the like. When the rolling ball 9 is large, the allowance for a single crush is also large. If the time for one crush is too large, the load increases, so that the rolling can be performed in two or more times.
For example, for a ball holder 5 having ten guide holes 51, five guide holes are rolled in the first rotation, and all the guide holes including the remaining five guide holes are rolled in the second rotation. Perform rolling.

As a specific example of the crushing allowance, when the width of the guide groove is 16 mm and the diameter of the rolling ball is 16 mm, the crushing allowance on one side is preferably 0.01 to 0.6 mm. If the crushing width exceeds 0.6 mm, the resistance at the time of rolling becomes too large, and the guide groove of the rolling disc may be deformed, and an accurate concave curved portion cannot be formed on the inner wall surface of the guide hole. If the crushing margin is less than 0.01 mm, the rolling cost is too high. Preferred one side squeeze allowance is 0.02-0.5m
m. If the crushing margin on one side exceeds 0.3 mm,
As described above, the rolling process is divided into a plurality of steps without rolling all the guide holes at one time, so that the rolling accuracy can be obtained and the life of the rolling discs, rolling balls, etc. can be improved. Grows.

[2] Manufacturing Method First, as shown in FIG. 1, a rolling ball 9 is formed in the enlarged diameter portion (circular hole portion) 51a of the guide hole 51 of the ball holder 5 which has been subjected to the primary processing.
And a pair of rolling discs 1 and 2 are coaxially mounted on both sides of the ball holder 5 and relatively rotatably held. When the rolling balls 9 are held by the guide grooves 11 and 21 on one of the rolling disks 1 and 2, the ball holder 5 is locked by the rolling balls 9.

As described above, (i) both rolling disks are rotated in the opposite direction by the same force, or (ii) one rolling disk is fixed and the other rolling disk is rotated. Thereby, the pair of rolling disks 1 and 2 are relatively rotated.

In the case of (ii), when the rotating disk 2 is rotated while the fixed disk 1 is fixed, the corresponding guide grooves 11
As can be seen by focusing on a and 21a (see FIG. 8), when the guide groove 21a rotates clockwise, the guide grooves 11a and 21a are rotated.
The rolling ball 9 held at the intersection with a is forcibly moved in the outer peripheral direction. When the rolling ball 9 reaches the outer end of the guide hole 51, the rolling is completed (FIG. 8B). When the rotating disk 2 is inverted, a more uniform concave curved surface portion can be formed. In this manner, the rolling ball 9 is forcibly moved from one end of the guide hole 51 to the other end by the rotation of the rotary disk 2, whereby a concave curved surface is formed on the inner wall surface of the guide hole 51.

The number of the guide holes 51 to be rolled at one time can be appropriately set according to the size of the crushing allowance of the guide holes 51 and the like. When rolling is performed by inserting the rolling balls 9 in all the guide holes 51, the rolling balls 9 adjacent to the guide holes 51 are pressed against each other, and a guide hole having a width closer to the diameter of the rolling balls 9 is formed. The width of the flat portion of the guide hole can be easily set. However, if the crushing allowance is large, a high rotational torque is required. For example, every other guide hole is required.
The rolling torque is reduced by using the rigidity of the tension between the guide holes by rolling by putting the rolling ball 9 in the roller 15. Next, the rolling balls 9 are transferred to the remaining guide holes 15 to perform rolling. It is preferable to perform the rolling step by dividing the rolling step into several steps because the finishing accuracy is improved, the life of the jig is extended, and the manufacturing cost is reduced.

Thus, the guide hole of the ball holder 5 is
A concave curved surface portion can be formed on the inner wall of the inner wall 51 simply and in a short time with only a few rolling operations. Further, the surface roughness of the finished surface is improved as compared with the processing using a tool.

Although the present invention has been specifically described above, the present invention is not limited to these examples, and various changes can be made without departing from the gist of the present invention. For example, the assembly shown in FIG. 1 may be put in a case, and a lubricant may be added as necessary to perform rolling.

[0052]

EXAMPLE 1 FIG. 1 and the disk 2 for rolling shown in FIG. 2 (JIS SUJ2
, Hardness (HRC) 60) and rolling ball 9 (φ16.00,
Ball holder 5 with 10 guide holes (φ44mm, thickness 5.5mm, guide hole width 16.0mm, JIS SUP10, hardness (HRB) 89.4 using JIS SUJ2, hardness (HRC) 63-67) ), A concave curved surface portion of the inner wall of the guide hole 51 was formed by a rolling method.

First, the ball holder 5 is cut, and the crushing allowance on one side is 0.1 mm (the width of the guide hole is 15.8 m).
m, Example 1), and the guide hole 51 was formed to be 0.2 mm (guide hole width was 15.6 mm, Example 2). In the circular hole 51a of the guide hole 51 of the ball holder 5 which has been subjected to the primary processing,
Rolling balls 9 (φ16.00, made of JIS SUJ2, hardness (HR
C) 63-67) were put and set in a rolling device. The first rolling was performed by reciprocating the rotating disk 2 with a torque wrench. Next, five rolling balls 9 are inserted into the remaining guide holes 51 so that a total of ten rolling balls 9 are used, and the rotary disc 2 is reciprocated to rotate. went. The torque at each reciprocating rotation was recorded and is shown in Table 1. The following measurement was performed on the rolled ball holder 5. The measurement results are also shown in Table 1.

(1) Variation of the width of the guide hole 51 The width (maximum part) of the guide hole 51 is measured with a cylinder gauge.
The variation with the target width (16.00 mm) was determined.

(2) Three-dimensional position error of concave wall surface of guide hole 51 The three-dimensional position of the concave wall surface of guide hole 51 was measured using a three-dimensional measuring device, and the maximum error from the design value was obtained.

(3) Error in Cross Section R of Guide Hole 51 The radius R of the concave wall surface of the guide hole 51 was measured using a three-dimensional measuring device, and the error range from the radius of the rolling ball 9 was determined.

(4) Surface Roughness The surface roughness of the concave wall surface of the guide hole 51 was measured with a surface roughness meter.

Table 1 Item Example 1 Example 2 Pressing allowance (mm) 0.1 0.2 Torque at the time of first rolling (kgm) Outgoing path (5 balls) 15 25 Return path (5 balls) 5 5 Second rolling Manufacturing torque (kgm) Outgoing path (10 balls) 20 30 Return path (10 balls) 5 7 to 10 Guide hole dimensions Width variation (mm) 0.01 0.03 Positional error (mm) φ0.01 φ0.03 Cross-sectional R Error (mm) Within 0.005 0.01 to 0.015 Surface roughness (Ry) (μm) 0.29 to 0.76 0.25 to 0.38

Examples 3, 4 Rolling balls 9 of φ16.10 mm (made of JIS SUJ2, hardness (HRC
) 63-67) and the rolled balls 1 and 2 shown in FIGS. 1 and 2 were used to roll the ball holder 5 as in the first embodiment. However, the crushing margin on one side of the guide hole 51 is
0.2mm (width of guide hole 51 is 15.6mm, Example 3) and 0.3m
m (the width of the guide hole 51 is 15.4 mm, Example 4). Ten rolling balls 9 were placed in the circular hole 51a of the guide hole 51 of the ball holder 5, and set in a rolling device. Next, rolling was performed by reciprocatingly rotating the rotary disk 2 with a torque wrench. The torque during reciprocating rotation was recorded. Further, for the rolled ball holder, variations in the width of the guide hole 51, a three-dimensional position error of the concave wall surface of the guide hole 51, an error in the cross section R of the guide hole 51, and the surface roughness were determined in the same manner as in the first embodiment. A measurement was made. Table 2 shows the results.

Table 2 Items Example 3 Example 4 Pressing allowance (mm) 0.2 0.3 Torque at the first rolling (kgm) Outbound path (10 balls) 94 249 Return path (10 balls) 12-18 15-20 Guide hole dimensions Width variation (mm) 0.01 0.01 Position error (mm) φ0.025 φ0.03 Cross-sectional R error (mm) 0.05 to 0.1 0.05 to 0.1 Surface roughness (Ry) (μm) 2.0 0.6

Example 5 Rolling balls 9 of φ16.00 mm and φ16.10 mm, and FIG.
Using the rolled disc shown in FIG. 2 and FIG. 2, the same ball holder 5 as in Example 1 was rolled. However, the crushing allowance on one side of the guide hole 51 was set to 0.4 mm (the width of the guide hole was 15.2 mm).
Circular hole 51 of guide hole 51 of ball holder 5 that has been subjected to primary processing
The first rolling was performed by putting ten rolling balls 9 in a, setting the rolling balls in a rolling device, and rotating the rotary disk 2 back and forth with a torque wrench. Next, five rolling balls 9 were transferred to the remaining guide holes 51, and the rotary disk 2 was reciprocated to perform the second rolling. Further, a rolling ball 9 having a diameter of 16.00 mm was inserted into all the guide holes 51, and the third rolling was performed. Finally, a rolling ball 9 of φ16.10 mm was put into all the guide holes 51, and a fourth rolling was performed. The torque during each forward rotation was recorded. Further, for the rolled ball holder 5, measurement of the variation of the width of the guide hole, the three-dimensional position error of the concave wall surface of the guide hole 51, the error of the cross section R of the guide hole 51, and the surface roughness were performed in the same manner as in Example 1. Was done. Table 3 shows the results.

[0062]

[0063]

As described above in detail, the apparatus for manufacturing a ball holder for a differential gear according to the present invention comprises a pair of rolling balls each having a rolling ball and a guide groove for regulating the movement of the rolling ball. The rolling ball is relatively rotated along the inner wall of the guide hole by the action of the guide groove by rotating the rolling disk relatively. As a result, since the structure having the concave curved surface portion formed on the inner wall surface is formed, the structure is simple and the guide hole of the ball holder can be formed in a short time. Therefore, there is obtained an advantage that the manufacturing cost can be reduced and the surface roughness of the concave curved surface portion is improved.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a manufacturing apparatus of a ball holder for a differential device according to a preferred embodiment of the present invention.

FIGS. 2A and 2B are plan views showing guide grooves of a rolling disc used in the apparatus of FIG. 1, wherein FIG. 2A shows an example of a guide groove composed of a plurality of grooves, and FIG. 4 shows a guide groove.

FIG. 3 is a partial sectional view showing a guide groove of a fixed rolling disc.

FIG. 4 is a front view showing a state in which a fixed rolling disc and a ball holder are combined.

FIG. 5 is a front view showing a state where a fixed rolling disc and a rotating rolling disc are combined.

FIG. 6 is a view showing the shape of a guide hole.

FIG. 7 is a partial cross-sectional view showing an enlarged diameter portion of a guide hole.

FIG. 8 is a front view showing a state in which a fixed rolling disc, a rotating rolling disc, and a rolling ball are combined; FIG. 8A shows a state before rolling; ) Indicates the state after rolling.

FIG. 9 is a longitudinal sectional view showing a differential device disclosed in Japanese Patent Application Laid-Open No. 8-170705.

10 is an exploded cross-sectional view of the differential shown in FIG.

11 is an exploded front view showing one disk plate, a ball holder, and a ball in the differential device shown in FIG. 9;

FIG. 12 shows one disk plate of the differential device of FIG. 9,
It is a front view which shows the state which combined the ball holder and the ball.

13 is a partially enlarged front view illustrating details of a meandering continuous groove of the disk plate of FIG. 12;

14 is a diagram in which one unit section of the meandering continuous groove of FIG. 13 is linearly developed.

FIG. 15 is a partial sectional view showing a shape of an inner wall surface of a guide hole of the ball holder.

FIG. 16 is a schematic cross-sectional view showing a special end mill for processing the inner wall surface of the guide hole of the ball holder.

[Explanation of symbols]

 Rolling discs 11, 21 ... Guide grooves 12, 22 ... Protrusions 13, 23 ... Opposing surfaces 3, 4 ... Disc plates 31, 41 ··· Meandering continuous groove 31a ··· First guide section 31b ··· Second guide section 31c ··· Third guide section 5 Ball holder 51 ··· Guide hole 6 ···・ Ball 7,8 ・ ・ ・ Thrust washer 9 ・ ・ ・ ・ ・ ・ Ball for rolling 10 ・ ・ ・ ・ ・ ・ Case 20 ・ ・ ・ ・ ・ ・ Case cover

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Akira Mikami 13 Kinuigaoka, Moka City, Tochigi Prefecture Hitachi Metals Co., Ltd. Moka Plant (72) Inventor Shuji Yamada 13 Kinugaoka, Moka City, Tochigi Prefecture Hitachi Metals F-term in Moka Plant Co., Ltd. (reference) 3J051 AA03 BA02 BB02 BD02 BE09 CA09 CB04 EC07 FA02

Claims (11)

[Claims] 1. An apparatus for manufacturing a ball holder for a differential device having a plurality of guide holes for holding a ball in a radial direction at equal intervals in a circumferential direction. And (2) a pair of rolling discs provided with guide grooves for rollingly holding and guiding the rolling balls on opposing surfaces. (3) means for holding a pair of rolling discs on both sides of the ball holder with the rolling balls inserted in the guide holes and relatively rotating the pair of rolling discs, The rolling ball is forcibly moved along the inner wall of the guide hole by the relative rotation of the forming disc, so that the concave curved surface portion corresponding to the rolling ball is rolled on the inner wall surface of the guide hole. Ball holder for differential gear characterized by Da manufacturing equipment. 2. A manufacturing apparatus for a ball holder for a differential gear according to claim 1, wherein one of said pair of rolling disks is fixed, and the other is rotatably held, and said other rolling disk is held. An apparatus for manufacturing a ball holder for a differential device, wherein rolling is performed by rotating a disc for rotation. 3. A manufacturing apparatus for a ball holder for a differential gear according to claim 1, wherein said pair of rolled disks are both held rotatably, and both rolled disks are rotated in opposite directions. An apparatus for manufacturing a ball holder for a differential device, comprising: 4. The manufacturing apparatus for a ball holder for a differential device according to claim 1, wherein said guide groove comprises a plurality of linear or curved grooves, each of which is formed in a radial direction. A ball holder for a differential gear characterized by being inclined right or left. 5. The manufacturing apparatus for a ball holder for a differential device according to claim 1, wherein the guide groove extends from the outside in the radial direction to the inside, and the guide groove extends from the inside in the radial direction. A continuous guide groove extending outward in the circumferential direction of the disk surface and a continuous meandering groove, and always intersects with the guide hole. . 6. The manufacturing apparatus for a ball holder for a differential device according to claim 1, wherein a crushing allowance of the guide hole is 0.01 to 0.6 mm on one side. Ball holder manufacturing equipment. 7. The manufacturing apparatus for a ball holder for a differential device according to claim 1, wherein the guide groove has a radially enlarged portion at one end in a radial direction, and the rolling ball is provided with the rolling groove. An apparatus for manufacturing a ball holder for a differential, wherein a pair of rolling discs is placed on both sides in a state of being inserted in an enlarged diameter portion. 8. The manufacturing apparatus for a ball holder for a differential device according to claim 1, wherein an inner wall surface of the guide hole of the ball holder comprises a concave curved surface portion and flat portions on both sides thereof. The diameter of the rolling ball is the width of the flat part + 0.
An apparatus for manufacturing a ball holder for a differential, wherein the diameter is 0 to 0.1 mm. 9. A method for manufacturing a ball holder for a differential gear having a plurality of guide holes for holding a ball in a radial direction at equal intervals in a circumferential direction, wherein (a) the ball holder has a crushing allowance in advance. (B)
A pair of rolling discs provided with guide grooves for rollingly holding and guiding the rolling balls on opposing surfaces, with the rolling balls inserted into the guide grooves of the ball holder. (C) relatively rotating a pair of rolling discs to forcibly move the rolling ball along the inner wall of the guide hole, thereby forming the guide hole. Forming a concave curved surface portion corresponding to the rolling ball on an inner wall surface of the ball holder. 10. The manufacturing method of a ball holder for a differential gear according to claim 9, wherein one of the pair of rolling disks is fixed, the other is rotatably held, and the other rolling disk is held. A method for manufacturing a ball holder for a differential device, characterized in that rolling is carried out by rotating a roller. 11. The method for manufacturing a ball holder for a differential gear according to claim 9, wherein both of the pair of rolled disks are relatively rotatably held, and both rolled disks are moved in opposite directions. A method for manufacturing a ball holder for a differential device, comprising rolling by rotating.