KR100326348B1 - Sintered internal gear and manufacturing method thereof - Google Patents

Abstract

Manufacture of sinter internal gear and sinter internal gear which can improve the rigidity of each part, improve the position accuracy of internal gear, and improve the position accuracy of internal gear at the same time Provide a method. An attachment root portion 29 of the helical gear 7 formed at one end of the thrust direction 125 of the outer cylindrical body 124 is extended toward the inner diameter direction to extend the flange-side gear side disk surface 30. The inner tapered portion 31 inclined at a predetermined angle with respect to the direction is connected to the outer peripheral end gear side disk surface 30 of the flange portion 126. The outer tapered portion 33 is located between the tooth tip end portion 28 of the helical gear 7 and the outer circumferential surface 124a of the outer cylindrical body 124 in the radial direction.

Description

Sintered internal gear and manufacturing method {SINTERED INTERNAL GEAR AND MANUFACTURING METHOD THEREOF}

The present invention relates to a sintered internal gear with improved balance of weight, formability, price, and strength, and a manufacturing method thereof.

Conventionally, this type of internal gear is known to have a flange portion and a helical gear portion, which are used in the planetary gear device of an automatic transmission described in Japanese Patent Application Laid-Open No. 5-58178 and the like, which are separately formed and are combined with each other. have.

Moreover, when attempting to integrally form such internal gears by sintering molding, consideration is given to those shown in FIG.

In this case, the sintering internal gear 1 composed of the sintered metal is mainly provided at the substantially cylindrical outer cylindrical body 2 and at one end edge 3 of the outer cylindrical body 2 in the thrust direction. It consists of the flange part 4 which shows a disk shape substantially, and the boss | hub part 5 formed in the substantially center of this flange part 4. As shown in FIG.

In the double outer cylindrical body 2, a helical gear 7 as an internal gear portion is formed on the inner circumferential surface portion 6.

Moreover, in the thrust direction one edge 3 of this outer cylindrical body 2, the outer peripheral part 9 of the outer diameter part 8 of the said flange part 4 is shown by the PP line in a figure. Through the connecting surface 12 formed in an annular shape, it is provided so that it may be integrated.

In addition, a shaft hole 10 through which a shaft or the like is inserted into the boss portion 5 is provided along the thrust direction of the helical gear 7 and a spline 11 is formed on the inner circumferential surface of the shaft hole 10. ) Is formed.

And this flange part 4 is comprised so that it may become the taper shape inclined from the said boss | hub part 5 to the outer diameter part 8 of this flange part 4, and inclined by a predetermined gradient.

In the conventional sintered internal gear 1 configured as described above, the flange portion 4 is formed so as to exhibit the tapered shape, so that the outer diameter portion close to the helical gear 7 can be improved while improving the rigidity near the repair portion 5. In (8), weight reduction in a large area is performed.

However, in such a conventional case, the helical gear 7 is moved from the outer circumferential surface 2a of the outer cylindrical body 2 to the outer cylindrical body 2 via the annular connecting surface 12 in the thrust direction. It is connected to the tooth tip end part 7a of the toothed part, and is connected to the helical gear 7 side end surface of the outer peripheral end 9 of the said flange part 4, and is supported.

For this reason, in order to reduce weight, when the taper shape inclined by the predetermined | prescribed gradient is provided in the flange part 4, the support base 9a of the outer peripheral end 9 located in the outer diameter part 8 will become thin. At the same time, there has been a problem that a close difference occurs at a position close to the support base portion 9a in the radial direction during compression.

Therefore, when this helical gear part 7 is compression-molded and it is pulled out from the processing metal mold | die, there exists a possibility that it may bend and deform | transform from this thin outer peripheral end part 9a.

In addition, when the density difference is severely changed, there is a concern that cracks may occur.

Furthermore, when the dimensional accuracy is insufficient after surface hardening, a so-called sizing is performed in the internal gear 1 manufacturing process in which the sintered compact is pressed into the mold and recompressed and the dimension is corrected.

If the outer circumferential end support base 9a located at the outer diameter portion 8 of the flange portion 4 exhibits a thin state, the outer cylindrical member is subjected to such sizing to the helical gear portion 7. There was a fear that the support stiffness was insufficient at the device low end position of (2), the flange portion 4 was deformed, and the positional accuracy of the internal gear portion was impaired.

Adjacent to such a thin trunk portion, the root portion with the helical gear portion 7 is in a thick state requiring a large amount of sintered metal raw material in the thrust direction. For this reason, since the density changed violently, it became the cause of the crack c1.

Further, close to the root portion with the helical gear 7 attached, a dense difference also occurs at one end of the thrust direction connecting the outer cylindrical body 2 to generate a crack c2 at the time of removing the mold or sizing. There was a concern.

In addition, even in the distal end portion of the helical gear portion 7, a large amount of sintered metal raw material is required in the thrust direction, so that the predetermined hardness is given to the distal end portion of the helical gear portion 7. It was difficult.

In particular, even if the taper is formed to the extent that the chamfering R 9b is formed in the outer circumferential support base 9a, if the upper surface 9c of the outer circumferential end support 9a is planar, a predetermined hardness is obtained. In order to obtain a predetermined hardness, it is difficult to raise the molding pressure of the upper and lower punch molds, resulting in a decrease in the life of the mold itself.

The present invention is to provide a sintering internal gear that can improve the positional accuracy of internal gears while suppressing an increase in weight, and further reduce the compactness difference during compression molding to improve the rigidity of each part. Doing.

FIG. 1 is an enlarged cross-sectional view for explaining an important part configuration of the sintered internal gear of Example 1. FIG.

FIG. 2 is an enlarged cross-sectional view for explaining the configuration of important parts of the sintered internal gear of Example 1. FIG.

3 is an enlarged cross-sectional view illustrating the configuration of important portions of the sintered internal gear of the first embodiment and illustrating the internal gear attachment root portion.

Fig. 4 is a cross-sectional view showing the molding die of the sintered internal gear of Example 1, showing the raw material filling state on the left side of the center line h and the compressed state on the right side of the center line h.

Fig. 5 is a sectional view showing the sizing mold of the sintering internal gear of Example 1, showing the sizing compression state on the left side of the center line h and the mold disassembly state on the right side of the center line h.

6 is a flowchart illustrating a manufacturing process of the sintered internal gear.

7 is an enlarged cross-sectional view of a sintering internal gear of the second embodiment and an important part.

FIG. 8 is a cross-sectional view illustrating a configuration of the sintered internal gear of Embodiment 3 of the present invention, and taken along the line I-I in FIG. 10.

9 is an enlarged cross-sectional view for explaining a configuration of an important part of the sintered internal gear of the third embodiment.

Fig. 10 is a front view illustrating the structure of the sintered internal gear of the third embodiment and seen from the helical gear direction.

Fig. 11 shows the sintering internal gear of Example 3, and is an enlarged cross-sectional view of an essential part of the sintering internal gear in the forming die.

FIG. 12 is a cross-sectional view showing a shape of forming the sintered internal gear of the third embodiment and explaining a shape in which the molding mold is closed. FIG.

FIG. 13 is a cross-sectional view showing a shape of forming the sintered internal gear of Example 3 and explaining the shape in which the molding mold is closed. FIG.

It is sectional drawing explaining the structure of the whole internal gear installed in the automatic transmission etc. of a prior art example.

In order to solve the said subject, according to the 1st aspect (aspect) of this invention, while forming an internal gear part in the inside of a substantially cylindrical outer cylindrical body, it is provided in the thrust direction one edge of this outer cylindrical body. And a sinter internal gear integrally connected to the flange portion of the disk portion, wherein the attachment root portion of the internal gear formed at one end of the thrust direction of the outer cylindrical body is extended toward the inner diameter direction and the disk portion on the flange portion gear side is provided. The inner tapered portion inclined at a predetermined angle with respect to the extension installation direction is characterized by a sintered internal gear connected to the outer peripheral end gear side disk surface of the flange portion.

For example, the predetermined angle of the said inner tapered part is comprised so that 45 degrees +/- 15 degrees with respect to the flange part gear side disk surface extension installation direction.

In this structure, the root portion of the internal gear formed on one edge of the thrust direction of the outer cylindrical body extends toward the inner diameter direction and is inclined at a predetermined angle with respect to the flange-side gear side disk surface extension installation direction. The tapered portion is smoothly connected to the outer circumferential end gear side of the flange portion and improves the fluidity of the sintered raw material during compression molding in this inner tapered portion. At the same time, the difference in density is alleviated, the thickness in the thrust direction is also increased, the rigidity of the attachment root portion of the internal gear is improved, and the occurrence of cracks is suppressed.

In addition, according to the second aspect of the present invention, the internal gear is formed inside the substantially cylindrical outer cylindrical body, and at the one end edge of the thrust direction of the outer cylindrical body, the substantially disk-shaped flange part is integrated. A sintered internal gear connected to the end of the outer cylindrical body in the thrust direction of one end edge and the outer end portion of the connecting portion of the outer peripheral end of the flange portion, the tooth tip end of the internal gear in the radial direction and the outer cylindrical body The sintered internal gear is formed with an outer tapered portion located between the outer circumferential circles.

In this configuration, the outer tapered portion has a toothed tip end portion of the internal gear portion and the outer cylindrical portion in the radial direction at one end of the thrust direction of the outer cylindrical body and the outer end portion of the connecting portion of the outer peripheral portion of the flange portion. Since it is located between the outer circumferential circles of, the enlarged area fraction obtained by the inclination of the outer tapered portion, the contact area between one side of the mold and the sintered metal raw material increases, and the compacted area is improved to increase the forming pressure. It is possible to secure the predetermined rigidity by increasing the density of the device portion of the outer cylindrical body without work. Moreover, since a taper is provided, a raw material flows along a taper, and a flow characteristic improves and a density difference disappears.

Therefore, cracks can be prevented and durability of the molding die can be made good.

Moreover, according to the 3rd aspect of this invention, while forming an internal gear part inside a substantially cylindrical outer cylindrical body, at the edge of the thrust direction one end of this outer cylindrical body, a substantially disk shaped flange part is carried out. As a sintered internal gear connected integrally,

An outer tapered portion that exhibits an angle at the one end edge of the outer cylindrical body and the outer end portion of the connection portion of the outer peripheral portion of the flange portion, the angle being substantially orthogonal to the waterline lowered from the thrust direction central portion of the internal gear portion to the outer end portion. The formed sintered internal gear is characterized.

The angle orthogonally orthogonal here is about 90 degrees +/- 15 degrees specifically ,.

In such a configuration, the thrust direction one end of the outer cylindrical body and the outer tapered portion formed at the outer end portion of the connection portion of the outer peripheral end portion of the flange portion, the male line is lowered from the thrust direction center portion of the internal gear portion to the outer end portion; Since the angle is substantially orthogonal, the sintered metal raw material is pressed and filled in the tooth tip end direction of the internal gear during compression molding.

For this reason, since the sintered metal raw material is fully filled in the tooth tip part and the attachment root part of an internal gear part, predetermined rigidity can be ensured without generating a rough part.

Moreover, in the part in which the other side taper-shaped part is formed, and the outer peripheral part of a flange part, thickness becomes thin, weight reduction can be extensively achieved, and the inertia rate can be improved. A sintering internal gear is provided adjacent to the tapered portion and provided with a flat end portion formed substantially parallel to the gear side disk surface of the flange portion.

In such a configuration, the flat end portion is formed to be substantially parallel to the gear side disk surface of the flange portion adjacent to the tapered portion.

For this reason, even if the thrust bearing support boss recess is formed in a flange part, for example, the thickness of the thrust direction becomes thin at the edge of this boss concave part is suppressed, and the density difference with the adjacent taper part is completed. .

Further, the end portion includes a first end portion extending in a radial direction from a boss portion formed in the center of the flange portion, a tooth tip end member of the internal gear portion in the radial direction, and an outer circumferential circle of the outer cylindrical body. A sintering internal gear having a second end formed so as to be positioned therebetween, and at least one of each of the first and second ends formed with a punching hole for positioning is formed.

In such a configuration, the end portion includes a first end portion extending in the radial direction from a boss portion formed substantially in the center of the flange portion, a tooth tip end of the internal gear portion in the radial direction, and an outer circumference of the outer cylindrical body. Since the taper formed in the flange part has a 2nd end part formed so that it may be located between a circle | round | yen, and a step | shaft is formed in shape, rough uniformity of the thickness of thrust direction can be aimed at each part. For this reason, in the flange part diameter direction, the compression ratio of the sintered metal raw material of the adjacent part also becomes substantially uniform, and a dense difference is alleviated.

In addition, since at least one of the first and second end portions is provided with a positioning punch hole, the positioning punch hole can be formed in a substantially vertical direction with respect to the outer surface of the flange portion. For this reason, when removed from the molding die, the mold can be demolded and sized smoothly without causing unnecessary jamming and the like, and the increase in the molding process can be suppressed and the reduction in gear precision due to spreading and the like can be prevented. .

Furthermore, while the internal gear is formed inside the substantially cylindrical outer cylindrical body, at the one end edge of the thrust direction of the outer cylindrical body, the tooth tip end position is exceeded from the one end edge to the inner diameter direction. Thrust to form a substantially annular connecting surface portion which is extended in the form of a groove, and to form a substantially disk-shaped flange portion which integrally connects the gear side side of the outer circumferential end to the connecting surface portion; The sintering internal gear provided with the tapered surface part inclined toward the outer diameter direction in the outer diameter part of the said flange part is provided in the superposition | polymerization part of the direction.

In this structure, since the flange portion and the connection surface portion of the outer cylindrical body are overlapped with each other in the polymerization portion, the thickness in the thrust direction becomes thicker than the thickness of the non-overlapping portion of the outer diameter portion of the flange portion.

In this polymerization part, since the connection surface part shows the annular shape which extends in the inner diameter direction beyond the tooth line unit value of the said internal gear part from one edge, the flange outer diameter part exceeds the tooth line unit value of the said internal gear part. It can be connected to this connection surface part in the part near a neck part. As a result, a tapered shape is formed in the entire flange portion, so that a polymerized connection can be made at a portion where a high support stiffness near a thickened inner diameter is obtained even though the same tapered shape is formed. have.

Further, since the tapered surface portion inclined toward the outer diameter direction is provided, the sintered metal material near the outer circumferential end having a large moment of inertia can be reduced from the outer diameter portion of the flange portion.

Therefore, it is possible to improve the device position accuracy of the internal gear portion while suppressing the increase in weight.

The flange portion is characterized by a sintering internal gear provided with a connecting portion for integrally forming a boss portion at a substantially central position of the inner diameter portion by connecting the flange portion to show a tapered inclination along the outer diameter direction.

In this configuration, the boss portion is connected and integrally formed by the coupling portion in which the boss portion is inclined along the outer diameter direction at approximately the center of the inner diameter portion of the flange portion.

For this reason, the rigidity is improved in the place where the load in the vicinity of the boss part is large as a thick shape, and the weight increase can be suppressed as a thin shape in the outer diameter part of a flange part.

And a sintering internal gear configured to make the thrust direction thickness of one end of the thrust direction edge portion of the internal gear portion thicker than the rim thickness from the tooth bottom portion of the internal gear portion to the outer peripheral surface of the outer cylindrical body. do.

In this structure, the thrust direction thickness of the one end of the thrust direction of the internal gear portion is configured to be thicker than the rim thickness from the toothed portion surface of the internal gear portion to the outer circumferential surface of the outer cylindrical body. In addition to the load of only the hoop stress applied, the one edge thereof can secure rigidity that can withstand the thrust load of the internal gear.

For this reason, the support rigidity of the said outer cylinder body integrally provided in the outer peripheral part of the outer diameter part of a flange part can be improved further.

Further, the tapered inclination of the polymerization portion is a radial outer peripheral end between the end edges of the corner arc portions formed continuously with the polymerization portion from the tooth tip end portion of the internal gear portion to the pitch circle of the internal gear portion. It features a sintered internal gear configured to have.

In this structure, the outer peripheral end of the radial direction of the taper of the said superposition | polymerization part overlaps radially with respect to the edge of the corner arc part of the tooth tip part of the said internal gear part.

For this reason, since the load given from this internal gear part is transmitted directly to a thrust direction through a polymerization part, and is supported by a flange, even if a flange part reduces thickness of an outer diameter direction rather than a radial outer peripheral end, it is sufficient. Support rigidity is obtained.

Therefore, it is possible to further improve the positional accuracy of the internal gear while suppressing the increase in weight.

A sintering internal gear is provided at a position at which the outer circumferential end is formed, at which the molding die is divided.

In this configuration, since the divided position of the molding die is provided at the outer circumferential end forming position, unnecessary stress is dispersed without focusing on the outer circumferential end when the mold is removed, so that there is a fear of bending or deformation at the outer circumferential end. You can reduce it even more.

The thickness of the outer diameter portion of the flange portion in the thrust direction is not deformable with respect to the stress of the transmission torque transmitted from the boss portion to the internal gear portion, and the gear material is formed by the molding pressure during molding. A sintered internal gear which is configured to have a thickness larger than the minimum thickness capable of maintaining a predetermined shape is featured.

In such a configuration, in the outer diameter portion of the flange portion, the thickness in the thrust direction is not deformable with respect to the stress of the transmission torque transmitted from the boss portion to the internal gear portion, and at the same time, the gear is formed by the molding pressure during molding. Since the raw material is formed to a thickness that satisfies a condition such as to be larger than the minimum thickness to enable a predetermined shape to be maintained, even if the recess for the pinion gear arrangement is formed on the side of the flange gear, for example, sufficient rigidity is achieved. I can keep it.

In addition, an internal gear portion is formed inside the substantially cylindrical outer cylindrical body, and at one end edge of the thrust direction of the outer cylindrical body, the tooth line unit value is exceeded from the one end edge to the inner tooth direction. A thrust direction in which a substantially annular connecting surface portion extending from the inner side is formed, and a substantially disk-shaped flange portion for integrally connecting the gear side side of the outer peripheral end is formed, and the connecting surface portion and the outer peripheral end thereof are superimposed. Is a manufacturing method of a sintered internal gear having a tapered surface portion inclined toward the outer diameter direction in an outer diameter portion of the flange portion,

Compresses the gear material by combining a plurality of cylindrical molds having a radially divided surface of the molding die at a position where the radially outer peripheral end is formed near the inner diameter portion of the tapered surface portion, rather than the pitch circle forming position of the internal gear. A method for producing a sintered internal gear for molding is featured.

In such a configuration, the sintered internal gear integrally molded by compression removes each cylindrical mold separately when the mold is removed from the molding die, so that unnecessary stress is dispersed without concentrating on the outer peripheral part. The risk of bending and deformation from the end can be further reduced.

In addition, an internal gear is formed inside the substantially cylindrical outer cylindrical body in the sintering internal gear of any of the first, second, and third aspects, and the thrust of the outer cylindrical body is also provided. In one end of the direction, an approximately annular connecting surface portion extending from the one end edge beyond the tooth tip position of the internal gear portion in the inner diameter direction is formed, and the gear side side of the outer peripheral end is integrally connected to the connecting surface portion. A substantially disk shaped flange portion was provided, and further, a tapered surface portion inclined toward the outer diameter direction was provided in the outer diameter portion of the flange portion in the polymerization portion in the thrust direction where the connection surface portion and the outer circumferential end overlap.

In such a configuration, in addition to the effect of the sintering internal gear of any of the above aspects, the flange portion and the connection surface portion of the outer cylindrical body are overlapped with each other in the polymerization portion, so that the thickness in the thrust direction is increased. It becomes thicker than the thickness of the non-overlapping part of the outer diameter part of a branch.

In this polymerization part, since the connection surface part shows the annular shape which extends in the inner diameter direction beyond the tooth tip position of the said inner tooth gear part from one edge, the outer diameter part of a flange part exceeds the tooth line unit value of the said inner tooth part, and is near the inner diameter part. It can be connected to this connection surface part in the part of. As a result, the taper shape is formed in the entire flange portion, so that the polymerized connection can be performed at the portion where high support stiffness near the inner diameter portion, which is thickened even in the same tapered shape, is obtained even when the polymerized connection is made to the portion near the outer circumferential end. There is.

Moreover, since the tapered surface part inclined toward the outer diameter direction was provided, the sintered metal material near the outer peripheral end with a large moment of inertia can be reduced from this flange part outer diameter part.

Therefore, it is possible to improve the device position accuracy of the internal tooth gear portion while suppressing the increase in weight.

In addition, during compression molding, the sintered raw material flows along this tapered surface portion and improves the flow characteristics, whereby the density difference can be further reduced to prevent the occurrence of cracks.

Further, in the sintering internal gear according to any one of the first, second, and third aspects, the thrust direction thickness of one end edge of the thrust direction of the inner tooth gear portion is determined from the toothed cylindrical surface of the inner tooth gear portion. It is characterized in that it is configured to be thicker than the rim thickness to the outer peripheral surface of the.

In this configuration, in addition to the effect of the sintering internal gear of any of the first, second and third aspects, the boss portion is tapered along the outer diameter direction at approximately the center of the inner diameter portion of the flange portion. It is connected by the connection part which shows the inclination, and is integrally formed.

For this reason, the rigidity is improved in the place where the load in the vicinity of the boss part is large as a thick shape, and the weight increase can be suppressed as a thin shape in the outer diameter part of a flange part.

In addition, the sintered raw material flows in the direction of the boss portion along this connection portion at the time of compression molding, and improves the flow characteristics, thereby further reducing the difference in density and preventing the occurrence of cracks.

In the sintering internal gear according to any one of the first, second, and third aspects, the tapered inclination of the polymerized portion in the thrust direction in which the connecting surface portion and the outer circumferential end are nested is the internal gear portion. It is characterized by having an outer periphery end in a radial direction between the tooth | tip end part of the toothed edge part from the end edge of the corner arc part formed continuously with a superposition | polymerization part.

In this configuration, in addition to the effect of the sintering internal gear of any of the above aspects, the thrust direction thickness of one end of the thrust direction of the inner tooth gear portion is further increased from the toothed surface of the inner tooth gear portion to the outer cylindrical body. Since it is configured to be thicker than the rim thickness to the outer circumferential surface of the rim, in addition to the load of only the hoop stress applied to the rim, this one edge can secure the rigidity that can withstand the thrust load of the inner tooth gear portion.

For this reason, the support rigidity of the said outer cylinder body which is integrally provided in the outer peripheral part of the outer diameter part of a flange part can be improved further.

In addition, during compression molding, the sintered raw material flows along the thrust direction thickness portion at the one end of the thrust direction at the inner gear portion, and improves the flow characteristics, thereby further reducing the difference in density and preventing the occurrence of cracks.

Detailed Description of the Preferred Embodiments

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described, referring drawings. Furthermore, the same or equivalent parts as in the conventional example will be described with the same reference numerals.

Example 1 of the Invention

EMBODIMENT OF THE INVENTION Hereinafter, Example 1 of this invention is described, referring drawings. Furthermore, the same or equivalent parts as in the conventional example will be described with the same reference numerals.

1 to 6 show a sintered internal gear of the first embodiment of the present invention and a manufacturing method thereof.

First, the structure of the sintering internal gear 123 of the first embodiment will be described. The sintering internal gear 123 made of sintered metal is mainly a cylindrical outer cylindrical body 124 and the outer cylindrical body. It is mainly comprised by the flange part 126 which is connected to the thrust direction one edge edge 125 of the sieve 124, and shows the disk shape substantially, and the boss part 5 formed in the substantially center of this flange part 126. have.

The outer cylindrical body 124 is provided with the helical gear part 7 as an internal gear part in an inner peripheral surface part.

Then, the attachment root portion 29 of the helical gear portion 7 formed at the one end edge 125 in the thrust direction of the outer cylindrical body 124 is extended toward the inner diameter direction so that the flange portion gear side disk surface 30 The inner tapered portion 31 inclined at a predetermined angle with respect to the extension installation direction is connected to the gear side disk surface 30 at the outer peripheral end of the flange portion 126.

In the second embodiment, as shown in Fig. 3, a predetermined angle θ of the inner tapered portion 31 is θ = 45 ° with respect to the flange-side gear side disk surface 30 extending direction α. It is configured to indicate ± 15 °.

The thrust direction one end 125 of the outer cylindrical body 124 and the connection part outer end 32 of the outer peripheral end 126a of the flange portion have teeth of the helical gear 7 in the radial direction. An outer tapered portion 33 is formed between the distal end 28 and the outer circumferential surface 124a that is the outer circumferential circle of the outer cylindrical body 124 (between CC).

As shown in Fig. 2, the outer tapered portion 33 is a connection portion outer end 32 between the thrust direction one end edge 125 of the outer cylindrical body 124 and the flange outer peripheral end 126a. With respect to the end edge 34, an angle α substantially perpendicular to the waterline L lowered from the thrust direction center portion 27a (L1 = L2) of the helical gear portion 7 to the end edge 34 is shown. It is formed to

Here, the angle (alpha) which is substantially orthogonal is specifically about (alpha) = 90 degrees + (alpha) 1 ((alpha) 1 is less than 15 degrees).

In the first embodiment, a flat end portion 35 is formed adjacent to the outer tapered portion 33 and formed substantially parallel to the gear-side disk surface 30 of the flange portion 126.

First end portion 37 connected to the inner diameter side tapered portion 36 having a sloping slope extending from the radial direction from the boss portion 5 formed substantially in the center of the flange portion 126 at this end portion 35. ) Is installed.

The end 35 is connected to the first end 37 via a slightly tapered central tapered portion 38, and at the same time, the tooth tip end portion 28 of the helical gear portion 7 in the radial direction. And second end portions 39 formed between the outer circumferential surfaces 124a of the outer circumferential cylindrical body 124 (between CCs), so that each of the first end portions 37 and the second end portions 39 are provided. Is formed so as to show a two-stage end shape.

The first end portion 37 has a circular hole having a predetermined depth so that the positioning punch hole 40 is perpendicular to the flat portion of the outer surface of the first end portion 37 along the thrust direction. Formed.

Next, the structure of the molding mold which press-forms the sintered metal raw material which forms this sintering internal gear 123, and the sizing mold used at the time of sizing is demonstrated using FIG. 4 and FIG.

In the molding die used for compression molding of the first embodiment, as shown in Fig. 4, the spline 11 is provided at the shaft arrangement position, and the inside of the shaft hole 10 of the boss section 5 is provided. An approximately cylindrical core rod 101 to be formed is provided.

In the periphery of this core rod 101, the die 102 in which the annular shaping | molding space part 102a which accommodates the said sintered metal raw material is substantially centered is arrange | positioned previously.

An annular first to fourth lower punch member 103 to 106 is arranged between these core rods 101 and the die 102.

Of these, the first and fourth lower punch members 103 and 106 are configured to be able to slide upward in a mold sin.

In addition, the upper and lower positions of the first to fourth lower punch members 103 to 106 are opposed to the first to fourth lower punch members 103 to 106 to slide down from the upper side in the thrust direction. A first upper punch member 107 for tightening is provided.

In addition, in FIG. 4, the state of charge of the raw material is shown to the left of the center line h and the state of compression to the right of the center line h.

In the sizing die 108 used for the sizing of the first embodiment, as shown in Fig. 5, the sizing die 108 is provided at a shaft arrangement position, and the spline portion inside the shaft hole 10 of the boss portion 5 is provided. An approximately cylindrical core rod 109 is inserted into 11.

In the periphery of this core rod 109, the die 110 in which the annular molding space part 110a which accommodates the said sintered sintering internal gear 123 is substantially centered is arrange | positioned previously.

An annular first to third lower punch member 111 to 113 is arranged between these core rods 109 and the die 110.

Of these, the first lower punch member 111 is configured to be able to slide upward in mold dismantling.

Moreover, in the upper position of these 1st-3rd lower punching members 111-113, it opposes these 1st-3rd lower punching members 111-113, and it slides down along a thrust direction from the upper side, A first upper punch member 114 is provided.

5, the sizing compression state is shown to the left of the center line h and the mold disassembly state to the right of the center line h.

Next, the operation of the first embodiment will be described.

First, the sintered internal gear 123 of the first embodiment is manufactured.

That is, as shown in FIG. 6B, the sintered metal material (iron powder or other metal powder and lubricant) 120 as shown in FIG. 6A is blended and mixed in a predetermined ratio by the mixer 121, and FIG. As shown in 6c, a predetermined weight is filled into the molding space portion 102a formed by the die 102 of the molding die, the lower punch members 103, and the like.

That is, in FIG. 4, as shown on the left side from the center line h, the sintered metal material 120 or the like is placed on the upper surface portion of the die 102 in a state where the first upper punch member 107 is replaced upward. Charge until 102b) and approximately coincide.

4, the upper punch members 107 and the lower punch members 103 to 106 of the molding die are slid along the core rod 13, as shown to the right of the center line h. The compression molding is performed by applying a pressure of 3 to 7 tonf / cm ² from the up and down direction.

In this case, as shown on the right side of the center line h in FIG. 4, the first and fourth lower punch members 103 are moved at the same time as the first upper punch member 107 slides down from the upper side in the thrust direction. Sentence 106 is exalted.

At the time of mold clamping, as shown in Fig. 3, the attachment root portion 29 of the helical gear portion 7 formed at the one end edge 125 in the thrust direction of the outer cylindrical body 124 extends in the inner diameter direction. The outer peripheral end gear side disk surface of the flange portion 126 is provided by an inner tapered portion 31 inclined at a predetermined angle θ with respect to the flange portion gear side disk surface 30 extending direction. 30 is smoothly connected to the inner tapered portion 31, and the sintered raw material smoothly flows in the direction of the low pressure region according to the inner tapered portion 31 so that the fluidity of the sintered raw material at the time of compression molding is increased. To improve on.

For this reason, as shown in FIG. 2, the tightness of the connection part 29 of the thrust direction one end edge 125 of the attachment root part 29 of the helical gear part 7 adjacent to the radial direction, and the outer cylindrical body 124 is carried out. The difference is alleviated, the thickness in the thrust direction is also increased, the rigidity of the attachment root portion 29 of the helical gear portion 7 is improved, and the occurrence of cracks is suppressed.

Moreover, in the outer taper part 33, the thrust direction one end edge 125 of the said outer cylindrical body 124, and the connection part outer end part 32 of the said flange outer peripheral end part 126a are radial direction. It is located between the tooth tip end portion 28 of the helical gear 7 and the outer circumferential surface 124a of the outer cylindrical body 124 (between CC).

For this reason, the enlarged area obtained by the inclination of the outer tapered portion 33, the contact area between the upper first punch member 107 and the sintered metal material 120 increases, thereby improving the crimp area. The compression force is increased without raising the molding pressure. Therefore, the density of the apparatus part of the flange part 126 of the outer cylindrical body 124 can be raised and a predetermined rigidity can be ensured.

Therefore, cracks can be further prevented and the durability of the molding die can be improved.

And the outer tapered part 33 formed in the thrust direction one edge 125 of the said outer cylindrical body 124, and the connection part outer end 32 of the said flange outer peripheral end 126a is the said helical Since the angle is substantially orthogonal to the water line L lowered from the thrust direction center part 27a of the gear part 7 to the edge 34, the tooth tip end part 28 of the helical gear part 7 at the time of compression molding is shown. The sintered metal material 120 is pressed toward the tooth direction, and flows in the direction of the tooth tip end portion 28, and the tooth tip end portion 28 and the attachment root portion 29 of the helical gear portion 7, which have been easy to become a rough portion in the related art. Is densely charged.

In addition, in the first embodiment, the sintered metal material 120 in the forming space portion 102a forming the outer cylindrical body 124 is further raised from the first lower punch member 103 in the up and down direction. Compress them to be tightly opposite.

For this reason, since the sintered metal material 120 is fully filled in the tooth tip end part 28 and the attachment root part 29 of the helical gear part 7, predetermined rigidity can be ensured without generating a rough part. .

Moreover, in the part in which the outer tapered part 33 is formed, and the outer peripheral end of the flange part 126, thickness becomes thin, weight reduction can be achieved extensively, and the inertia rate can be improved.

In addition, adjacent to the outer tapered portion 33, a flat end portion 35 is formed substantially parallel to the gear side disk surface 30 of the flange portion 126.

For this reason, as shown in FIG. 2, for example, since the 1st end part 37 is formed so that it may become substantially parallel to the gear side disk surface 30 among the edge parts 35, the flange part 126 Even if the thrust bearing supporting boss concave portion 17 is formed in the c), the degree to which the thickness of the thrust direction becomes thin in the boss concave portion 17a is suppressed, and the adjacent central tapered portion Dense difference with (38) is alleviated.

Moreover, since the 2nd end part 39 is formed so that it may become substantially parallel with the gear side disk surface 30 among the edge parts 35, the grade which the thickness of the thrust direction of the said attachment root part 29 becomes thin is It is suppressed and the density difference with the adjacent outer taper-shaped part 33 is alleviated.

In the first embodiment, the end portion 35 extends from the boss portion 5 formed in the center of the flange portion 126 in the radial direction via the inner tapered portion 36. And a second end portion 39 formed so as to be located between the tooth tip end portion 28 of the helical gear portion 7 and the outer circumferential circle 124a of the outer cylindrical body 124 in the radial direction (between CC). Have Thus, since the taper formed in the flange part 126 shows the shape of two steps | steps, the roughening of the thickness of thrust direction is aimed at each part, and the sintered raw material connects these stepped parts, respectively. The outer tapered portions 33, 38 and the like can be smoothly flowed to achieve good fluidity of the sintered raw material at the time of compression. For this reason, the compression ratio of the sintered metal material 120 of the adjacent part in the radial direction of the flange part 126 also becomes substantially uniform, the density difference is alleviated, and rigidity can be improved in each part.

The molded powder body 123a of the sintered internal gear 123 that is integrally molded by compression is first formed when the mold is removed from the molding die composed of the upper and lower punch members 103 to 107, and the like. As the upper punch member 107 is removed, each of the first lower punch members 103 and the second lower punch members 104 are individually removed. Further, the second lower punch member 104 is removed while rotating, so that the helical gear portion 7 is formed.

Furthermore, each third lower punch member 105 and fourth lower punch member 106 are individually removed.

In the case of the mold removal, the joint portion of the flange portion 126 of the outer cylindrical body 124 is widened in the thrust direction by substantially equalizing at each portion, so that the support rigidity is improved, so that the device of the helical gear portion 7 is opened. There is no fear of compromising the positional accuracy.

Next, the compression molded powder compact 123a is heated at a high temperature below the melting point in the sintering furnace 115 for a predetermined time, as shown in FIG. 6D, so that diffusion bonding of the metal particles proceeds and alloys.

In order to further improve the quality and characteristics, and to obtain a finished product according to the purpose of use or use, after the surface hardening process thereof is performed, if the dimensional accuracy is insufficient, the sintered compact 123b is pressed into the sizing mold 108, The so-called sizing process of recompression and correction of dimensions is performed in the post-treatment step of the internal gear manufacturing step.

In the sintering internal gear 123 of the first embodiment, as shown in Fig. 6E, the alloyed powder compact 123b is placed in the sizing mold 108, and the upper punch member 114 of the sizing mold 108 is provided. ) And each of the lower punch members 111 to 113 and the like are slid along the core rod 109 to apply pressure again in the up and down direction.

In the first embodiment, the positioning punch hole 40 formed in the flat first end portion 37 with little influence on the density is formed in the substantially vertical direction with respect to the outer surface of the flange portion 126. Therefore, when removing from the first upper punch member 107 of the molding die shown in FIG. 10, it is possible to demould smoothly without causing unnecessary jamming or the like and again, the sizing shown in FIG. Even when the first upper punch member 114 of the die 108 is adapted for positioning in the rotational direction, the positioning is performed smoothly, so that it can be easily sized and the increase in the molding process can be suppressed. It prevents improper mounting during sizing and prevents the gear precision from being deteriorated.

In the first embodiment, since the thickness in the thrust direction can be ensured by the first end portion 37, the boss concave portion 17 for supporting the thrust bearing can be of the entire main surface type. For this reason, the density difference also decreases in the circumferential direction, and further generation of cracks can be suppressed.

After sizing, as shown in Fig. 6F, inspection is performed to obtain a sintered internal gear 123 as a finished product (6g in the drawing).

Example 2

Fig. 7 shows the sintering internal gear 223 of the second embodiment of the present invention. Furthermore, the same or equivalent parts as those in the first embodiment will be described with the same reference numerals.

In the sintering internal gear 223 of the second embodiment, an embodiment is attached to the root portion 129 of the helical gear portion 127 formed at one edge 25 of the outer cylindrical body 124 in the thrust direction. An inner tapered portion 31 extending in an inner diameter direction formed in the sintering internal gear 123 of 2, and inclined at a predetermined angle with respect to the flange-side gear-side disk surface 30 extending direction; The configuration is not installed.

The inner tapered portion 31 is configured in substantially the same manner as the sintering internal gear 123 of the first embodiment except that the inner tapered portion 31 is not provided.

Specifically, the helical gear portion 127 in the radial direction is provided on the thrust direction one end edge 25 of the outer cylindrical body 124 and the connection portion outer end portion 132 of the flange portion outer peripheral end portion 126a. An outer tapered portion 133 is formed between the tooth tip end portion 128 of the outer cylindrical member 124 and the outer circumferential surface 124a that is the outer circumferential circle of the outer cylindrical body 124 (between DD).

As shown in FIG. 7, the outer tapered portion 133 has a thrust direction one end edge 25 of the outer cylindrical body 124 and a contact portion outer end 132 of the flange outer peripheral end 126a. The angle α of the helical gear 127 from the thrust direction center part 127a (L3 = L4) of the helical gear 127 is substantially orthogonal to the waterline L lowered to the end edge 34. It is formed to represent.

The angle α that is substantially orthogonal is about α = 90 ° ± α2 (α2 is within 15 °).

In addition, the end 135 of the second embodiment is connected to the first end 137 through a slightly steep central tapered portion 38 and at the same time, the tooth tip end portion of the helical gear 127 in the radial direction ( 128 and a second end 139 formed between the outer circumferential surface 124a of the outer cylindrical body 124 (between DD) are provided. The two end portions 139 are formed to have a two end portion shape.

Of these, the second end 139 is set to have a larger length in the radial direction than the second end 39 of the first embodiment.

In the sintering internal gear 223 of the second embodiment configured as described above, the second end portion 139 adjacent to the outer tapered portion 133 has a radial direction compared to the second end portion 39 of the first embodiment. The length of is set to be large.

For this reason, since the 2nd end part 139 is formed so that it may become substantially parallel with the gear side disk surface 30, the extent to which the thickness of the thrust direction of the said attachment root part 129 becomes thin is suppressed, A predetermined configuration can be ensured, and at the same time, the difference in density with the adjacent outer cylindrical body 124, which is thinned by the outer tapered portion 133, is alleviated.

Other configurations, operations, and effects are substantially the same as those of the first embodiment, and thus description thereof is omitted.

Example 3

8 to 13 show a sintered internal gear of the third embodiment of the present invention and a manufacturing method thereof.

First, the configuration of the sintered internal gear 313 of the third embodiment will be described. The sintered internal gear 313 composed of sintered metal is mainly a cylindrical outer cylindrical body 2 and the outer cylindrical body. It is provided so that it may become integral with the edge part 3 of the thrust direction of (2), and consists of the flange part 14 which shows a disk shape substantially, and the boss part 5 formed in the substantially center of this flange part 14, have.

In the outer cylindrical body 2, a helical gear 7 serving as an internal gear is formed on the inner circumferential surface portion 6.

In addition, at one end edge 3 of the outer cylindrical body 2, an approximately annular connecting surface portion 16 extending in the inner diameter direction beyond the position of the tooth tip 7a of the helical gear 7 is provided. Formed. On the inner diameter side of the inner end face 16a of this connection surface part 16, the pinion gear arrangement recess 17 is formed in the main surface shape.

And the gear side surface 18a of the said outer peripheral end 18 is integrally connected to this connection surface part 16. As shown in FIG.

That is, in the outer diameter part 8 of the said flange part 14, the said connection surface part in which the gear side surface 18a of the outer peripheral end 18 is formed in an annular shape as shown by the 2-point lane of FIG. 8 or FIG. It has the superposition | polymerization part 20 connected with the outer side surface 16b of (16) over the predetermined length G in radial direction.

Furthermore, in the third embodiment, the connection surface portion 16 and the outer surface portion 16a are described as if they exist in the polymerization portion 20 for the purpose of explaining the connection shape and the stress transfer direction. The inner sintered internal gear 313 is integrally formed of the same sintered metal material, and is not partitioned by the connection surface portion 16 and the outer surface portion 16a.

By this polymerization part 20, through this connection surface part 16, the outer cylindrical body 2 which has the said helical gear 7, and the said flange part 14 are formed so that it may be integrated.

The boss portion 5 is provided with a shaft hole 10 through which a shaft or the like passes through the thrust direction of the helical gear 7. On the inner circumferential surface of the shaft hole 10, a spline 11 is formed to block the rotational movement of the shaft with respect to the boss portion 5 of the sintered internal gear 313. As shown in FIG.

Moreover, the flange part 14 is provided with the connection part 19 which connects the said boss part 5 integrally. The connecting portion 19 is provided with an inner diameter side tapered surface portion 19a that extends over the outer diameter portion 8 of the flange portion 14 and has a tapered shape inclined at a predetermined gradient toward the outer diameter direction.

Moreover, in the thrust direction polymerization part 20 which the said connection surface part 16 and the said outer peripheral end 18 are overlapped, in the outer diameter direction to the outer peripheral part 18 of the outer diameter part of the said flange part 14, The outer end side tapered surface part 21 inclined toward the outer end surface of the said one edge 3 toward the predetermined angle is provided.

In addition, in the third embodiment, the thrust direction thickness E of the one end of the thrust direction 3 of the helical gear 7 is the outer cylinder from the toothed bottom surface 7b of the helical gear 7. It is comprised so that it may become thicker than the rim thickness D to the outer peripheral surface 2a of the sieve 2.

The tapered inclination of the polymerization portion 20 is the end edge of the corner arc portion 7c which is formed continuously in the helical gear tooth tip portion 7a and the connection surface portion 16 of the polymerization portion 20 ( It is comprised so that the outer peripheral edge part 22 of the radial direction may be provided in the area | region F between 7d) and the pitch circle 7e of the helical gear 7.

In addition, the corner part of the said one edge 3 is provided with the seeding part 23 according to the circumferential edge shape.

Next, the structure of the shaping | molding die 101-107b which compression-forms the sintered metal material 120 which comprises this sintering internal gear 313 is demonstrated using FIGS. The molding dies 101 to 107b of the third embodiment are provided with a cylindrical core rod 101 which is provided at the shaft arrangement position and mainly forms the spline 9.

In the periphery of this core rod 101, the die 102 in which the annular molding space part which accommodates the said sintered metal material 120 is formed in the substantially center is arrange | positioned previously.

An annular first to fourth lower punch members 103 to 106 are arranged between these core rods 101 and the die 102.

Of these, the first and fourth lower punch members 103 and 106 are configured to be able to slide upward in a mold sin.

Moreover, in the upper position of these 1st-4th lower punching members 103-106, it slides down along a thrust direction from the upper direction, facing these 1st-4th lower punching members 103-106, First and second upper punch members 107a and 107b which perform mold clamping are provided.

The divided positions of the first upper punch member 107a and the second upper punch member 107b are provided near the cross-sectional position of the boss portion 5.

Next, the operation of the third embodiment will be described.

First, the mold clamping process of the sintered metal material 120 during the manufacturing process of the sintered internal gear 313 will be described with reference to FIGS. 12 to 13. First, as shown in FIG. In the state where the lower punch members 103 and 106 are evacuated downwardly, the sintered metal material 120 is filled until the surface coincides with the upper surface of the die 102.

Next, as shown in FIG. 13, the first and fourth lower punch members 103 and 106 are raised at substantially the same time as the first and second upper punch members 107a and 107b slide down along the thrust direction. Sentence crime is done.

The first upper punch member 107a and the first upper punch member 107a are formed when the sintering internal gear 313 integrally press-molded removes the mold from the molding die composed of the respective punch members 103 to 106 and the like. The second upper punch member 107b is individually removed and the first lower punch member 103 and the second lower punch member 104 are individually removed. Further, the second lower punch member 104 is removed while rotating, so that the helical gear portion 7 is formed.

Further, each third lower punch member 105 and fourth lower punch member 106 are individually removed.

For this reason, the frictional force generated by the sliding contact between the outer circumferential surface 2 and the sand processing die or the like during removal is transmitted to the part of the outer circumferential end 18 formed relatively thick as unnecessary stress, or the outer circumferential end 19b. Since it disperses without focusing and working in the vicinity, it is possible to reduce the possibility of bending and deforming at the outer circumferential end 18 as in the prior art.

After the mold clamping, the sintered internal gear 313 taken out is given a predetermined strength as the sintered metal by surface hardening by a surface hardening process.

After the surface hardening process is performed, when the dimensional accuracy is insufficient, a so-called sizing process in which the sintered compact is pressed into the mold, recompressed, and the dimension is corrected is performed in the internal gear 313 manufacturing process.

In this sintering internal gear 313, as illustrated in FIG. 9, the outer cylindrical body 2 is formed from a portion of the polymerization portion 20 which is overlapped with the outer peripheral end 18 of the flange portion 14. Of the outer cylindrical body 2 from the portion where the connection surface 16 of the < RTI ID = 0.0 >) < / RTI > and the thickness B in the thrust direction to the portion to be superimposed are overlapped with the flange portion 14 and the outer circumferential end 18. It is comprised so that it may become thicker than thickness A of the thrust direction to the part which the outer side surface 16b of the connection surface part 16 overlaps.

In this polymerization part 20, the connection surface part 16 shows the substantially annular shape which extends in the inner diameter direction from the helical gear end edge 3 beyond the position of the tooth tip 7a of the helical gear 7, The branch outer diameter part 8 can be connected to this connection surface part 16 over predetermined length G in the part near an inner diameter part beyond the position of the said helical gear tooth tip 7a.

As a result, the tapered shape is formed in the entire flange portion 14, so that the inner portion of the flange portion 14 becomes thick even in the same tapered shape as compared with the case where the one end edge 3 is polymerized and connected to a portion near the outer peripheral end 18. It can be polymerized connected in the part where high support rigidity near a neck part is obtained.

Furthermore, in the polymerization portion 20, the outer end side tapered surface portion 21 inclined toward the outer diameter direction is further formed in the outer diameter direction of the boss portion connecting portion 19 at approximately the center of the inner diameter portion of the flange portion 14. Therefore, since the inclined inner diameter side tapered surface portion 19a is provided, the sintered metal material at the periphery of the outer circumferential end 18 having a large moment of inertia and the boss portion 5 which is prone to stiffness is replaced with the outer diameter portion of the flange portion ( 8) and from the connecting portion 19 can be reduced.

Therefore, it is possible to improve the device positioning accuracy of the helical gear 7 while suppressing the increase in weight.

In addition, the tapered sintered raw material when the outer end side tapered surface portion 21, the inner diameter side tapered surface portion 19a inclined in accordance with the outer diameter direction of the boss portion connecting portion 19, and the seedling portion 23 are compressed. By flowing along the surface portions 19a and 21 and the chamfering 23 to improve the flow characteristics, it is possible to further reduce the difference in density and to prevent the occurrence of cracks, thereby improving the support rigidity.

In the third embodiment, since the taper is formed in the entire flange portion 14, the thickness C of the outer peripheral edge 19b of the connecting portion, which is the place where the load in the vicinity of the boss portion 5 is large, is taken as a thick shape. In addition to improving rigidity, the outer diameter portion 8 of the flange portion 14 can suppress the increase in weight as a thin shape.

In addition, during compression molding, the sintered raw material flows in the direction of the boss portion 5 along the connecting portion 19 and improves the flow characteristics, thereby further reducing the difference in density and preventing the occurrence of cracks. It can improve the support rigidity.

And the thrust direction thickness E of the thrust direction one edge 3 of the helical gear 7 is the outer peripheral surface of the outer cylindrical body 2 from the tooth bottom surface 7b of the helical gear 7. Since it is comprised so that it may become thicker than the rim thickness D to (2a), in addition to the load of only the huff stress applied to the rim of the outer cylindrical body 2, this one edge 3 is the said helical gear 7 Rigidity to withstand thrust load is secured.

For this reason, the support rigidity of the said outer cylindrical body 2 provided integrally with the outer diameter part outer peripheral end 18 of the flange part 14 can be improved further.

In addition, during compression molding, the sintered raw material flows along the thrust direction thickness E portion of the thrust direction one end edge 3 of the helical gear 7 and improves the flow characteristics, thereby further reducing the density difference. It is possible to prevent the occurrence of cracks and improve the support rigidity also in this respect.

In addition, the outer peripheral edge 22 in the radial direction is positioned in the region F between the end edge 7d and the pitch circle 7e of the helical gear 7, so that the polymerization portion 20 In the tapered portion, the outer peripheral end 18 in the radial direction overlaps in the radial direction with respect to the end edge 7d of the corner arc portion 7c of the tooth tip end portion 7a of the helical gear 7.

For this reason, since the load applied from the helical gear 7 is transmitted to the thrust direction directly through the polymerization part 20 and is supported by the flange part 14, in the flange part 14, the outer periphery of the radial direction is carried out. Even if the thickness of the outer diameter direction rather than the stage 18 is reduced by the outer end side tapered surface portion 21, sufficient supporting rigidity is obtained.

Therefore, the device position accuracy of the helical gear 7 can be improved while further suppressing the increase in weight.

Moreover, in the outer diameter part 8 of the said flange part 14, the thickness A of a thrust direction is not deformable with respect to the stress of the transmission torque transmitted from the said boss | hub part 5 to the helical gear 7. At the same time, since the sintered metal material forming the gear is formed to a thickness that satisfies a condition larger than the minimum thickness capable of maintaining a predetermined shape due to the molding pressure during molding, for example, the flange base gear side side. Even if the concave portion 17 for pinion gear arrangement installation is formed in 18a, sufficient rigidity can be maintained.

For this reason, the pinion gear arrangement of the planetary gear device is provided by providing the pinion gear arraying recess 17 between the outer diameter portion 8 and the inner diameter portion of the flange portion 14, which is relatively thick and easily secures rigidity. The on gear can be stored in the sintered internal gear 313 with good space efficiency.

In addition, in the third embodiment, since the load applied from the helical gear 7 is transmitted through the polymerization section 20 directly in the thrust direction and is supported by the flange section 14, it contributes almost to the improvement of the supporting rigidity. The volume of the seedling portion of the seeding portion 23 formed along the circumferential edge shape at the corners of the one end edge 3 not being cut can be further reduced compared to the conventional sintering internal gear 1. .

For this reason, the corner angle part of the said one edge 3 which was located in the outermost radial direction and became the factor which raises a rotation moment is sufficiently scraped off by the planting part 23, and further, the moment of inertia and weight The increase can be suppressed to provide a good sintering internal gear 313 having good rotational efficiency.

(Example)

Here, the difference between the thickness of each part in Fig. 9 according to the conventional shape and the original eye shape is shown below on the basis of the result of the test creation and confirmation.

Conventional shape

Thickness A... … 1.7mm

Thickness B... … 3.7 mm

Thickness C... … What was 3.2mm,

In case of the original shape

Thickness A... … 2.0mm

Thickness B... … 2.4mm

Thickness C... … Can be 3.2mm.

The ratio of thickness B and thickness A can be reduced from 3.7 / 1.7 = 2.176 times to 2.4 / 2.0 = 1.2 times in the present invention.

The ratio of thickness C and thickness A can be reduced from 3.2 / 1.7 = 1.886 times to 2.2 / 2.0 = 1.6 times in this case. When the thickness C is made constant in this manner, other thicknesses A and B can be relatively reduced.

As mentioned above, although embodiment 1-3 of this invention was described in detail by drawing, the specific structure is not limited to this embodiment 1-3, Even if there exists a design change etc. of the range which does not deviate from the summary of this invention, etc. Included in

For example, in the first embodiment, the formation of the outer tapered portion 33 has been described and described. However, the present invention is not particularly limited thereto. For example, forming a taper R about the end edge 34 is formed. Etc., the root portion 29 of the helical gear portion 7 formed at the one end edge 25 in the thrust direction of the outer cylindrical body 124 extends toward the inner diameter direction so as to extend the flange side gear side circle. On the other hand, the inner tapered portion 31 inclined at a predetermined angle with respect to the extending installation direction may be smoothly connected to the outer peripheral end gear side disk surface 30 of the flange portion 26.

In the first and second embodiments, the helical gear portion 7 is used as the internal gear, respectively, but the present invention is not limited thereto, and may be a gear having another shape such as a normal spur gear.

Furthermore, in the first to third embodiments, the outer taper portions 33 and 38, the inner tapered portion 31, etc. have been described in a straight line, but the present invention is not particularly limited thereto. The taper portion constituted by the present invention may be provided. In this case, the radius of curvature and the like are not limited, and the types of curves such as curves, for example, parabolic curves, etc., are not particularly limited.

In Example 3, by dividing the molding die into a plurality of punch members 103 to 107, the concentration of stress in the portion 20 where the thickness is increased and stress is difficult to concentrate in the polymerization portion 20 is further dispersed. However, the present invention is not limited thereto. For example, the divided position, the shape, the divided direction, the material, and the like, such as a molding die for integrally forming a punch and a die, are not limited to the third embodiment. Naturally, even molds are good.

The sintered internal gear according to the present invention can improve the position accuracy of the internal gear portion while suppressing the increase in weight, and can also improve the rigidity of each portion by reducing the compactness difference during compression molding.

Claims (20)

A sintering internal gear in which an internal gear is formed inside the substantially cylindrical outer cylindrical body, and at one edge of the thrust direction of the outer cylindrical body is integrally connected to the flange portion of the substantially cylindrical shape. The planar root portion of the internal gear formed at one end of the thrust direction of the sieve extends toward the inner diameter direction and is formed by the inner tapered portion inclined at a predetermined angle with respect to the flange-side gear side disk surface extension installation direction. A sintered internal gear which is connected to the disc surface of the outer peripheral end gear of the branch. A sintering internal gear in which an internal gear is formed on the inner side of the substantially cylindrical outer cylindrical body, and at one edge of the thrust direction of the outer cylindrical body is integrally connected to the flange portion of the substantially cylindrical shape. An outer tapered portion located between one end edge of the sieve in the thrust direction and the outer end portion of the connecting portion of the outer peripheral end of the flange portion is disposed between the tooth tip end portion of the internal gear portion and the outer peripheral circle of the outer cylindrical body in the radial direction. Sintered internal gear, characterized in that formed. A sintering internal gear having an internal gear portion formed inside the substantially cylindrical outer cylindrical body and integrally connecting a flange portion of the substantially cylindrical shape to one edge of the thrust direction of the outer cylindrical body. In the thrust direction one end edge of the flange portion, and the outer end portion of the connection portion of the outer peripheral portion of the flange portion, an outer tapered portion showing an angle substantially perpendicular to the waterline extending from the thrust direction center portion of the internal gear portion to the outer end portion is formed. Sintered internal gear. The sintering internal gear according to claim 2 or 3, wherein a flat end portion is formed adjacent to the tapered portion and formed substantially parallel to the gear side disk surface of the flange portion. The said end part is a 1st end part extended in the radial direction from the boss | hub part formed in the substantially center of this flange part, the tooth tip end member of this internal gear part in the radial direction, and this outer cylindrical body. A sintering internal gear having a second end portion formed so as to be positioned between the outer circumferential circles of the plurality of first and second end portions, wherein a punch hole for positioning is formed in at least one of the first and second end portions. An internal gear is formed on the inner side of the substantially cylindrical outer cylindrical body, and at the one end edge of the outer cylindrical body in the thrust direction, extending from the one end edge beyond the tooth tip position of the internal gear in the inner diameter direction. The thrust direction which forms the substantially annular connection surface part provided, forms a substantially disk-shaped flange part which integrally connects the gear side side of an outer peripheral end to this connection surface part, and this connection surface part and this outer peripheral end are overlapped. The tapered surface portion inclined toward the outer diameter direction is provided in the polymerization portion of the flange portion in the outer diameter portion. The sintering internal gear according to claim 6, wherein the flange portion is provided with a tapered inclination along the outer diameter direction so that a connecting portion integrally forming a boss portion at an approximately central position of the inner diameter portion is provided. The thrust direction thickness of the thrust direction one edge of the said internal gear part is comprised so that it may become thicker than the rim thickness from the toothed part surface of the said internal tooth gear part to the outer peripheral surface of the said outer cylindrical body. Sintered internal gear, characterized in that. 8. The tapered shape of the tapered portion of the polymerized portion is from the end edge of the corner arc portion formed continuously with the polymerized portion to the pitch circle of the internal gear portion. Sintered internal gear, characterized in that the outer peripheral end in the radial direction. 10. The sintering internal gear according to claim 9, wherein a split position of a molding die is designed at the outer peripheral end forming position. The thickness in the thrust direction of the outer diameter part of the said flange part makes a deformation | transformation impossible with respect to the stress of the transmission torque transmitted from the said boss part to the said internal gear part, and shaping | molding at the time of shaping | molding of Claim 6 or 7 is carried out. A sintered internal gear configured to have a thickness that is greater than a minimum thickness that enables the gear material to maintain a predetermined shape by pressure. An internal gear is formed inside the substantially cylindrical outer cylindrical body, and extends in the inner diameter direction from the one end edge beyond the tooth line unit value of the internal gear at the one end edge of the thrust direction of the outer cylindrical body. A substantially annular connection surface portion to be provided is formed, and the connection surface portion is provided with a substantially disk-shaped flange portion for integrally connecting the gear side surface of the outer circumferential end, and furthermore, in the thrust direction in which the connection surface portion and the outer circumferential end thereof are superimposed. In the polymerization portion, as a manufacturing method of a sintered internal gear having a tapered surface portion inclined toward the outer diameter direction in an outer diameter portion of the flange portion, Compression molding of a gear material is performed by combining a plurality of cylindrical molds having a radially divided surface of a molding die at a position where a radially outer peripheral end is formed near an inner diameter portion of the tapered surface portion near a pitch circle forming position of the internal gear. Sintered internal gear, characterized in that. The internal gear is formed inside the substantially cylindrical outer cylindrical body, and at the one end of the thrust direction of the outer cylindrical body, the one end edge is used. A substantially annular connecting surface portion extending beyond the tooth tip position of the internal gear and extending in the inner diameter direction is formed. An approximately disk-shaped flange portion for integrally connecting the gear side of the outer peripheral end is provided. A sintered internal gear comprising: a tapered surface portion inclined toward the outer diameter portion is provided in an outer diameter portion of the flange portion in a polymerization portion in a thrust direction where the connection surface portion and the outer circumferential end thereof overlap with each other. The thrust direction thickness of the thrust direction one edge of the said internal gear part is made thicker than the rim thickness from the toothed bottom surface of the internal gear part to the outer peripheral surface of the said outer cylindrical body in any one of Claims 1-3. Sintered internal gear, characterized in that configured to be. The taper-shaped inclination of the polymerization part of the thrust direction to which the said connection surface part and the said outer peripheral end are overlapped is formed continuously in the toothed tip part of the tooth gear part in any one of Claims 1-3. A sintered internal gear having a peripheral portion in the radial direction from the edge of the corner arc portion to the pitch circle of the internal gear portion. The tapered inclination of the polymerization portion is a radial direction between the end edges of the corner arc portions formed continuously with the polymerization portion from the tooth tip ends of the internal gear portion to the pitch circle of the internal gear portion. Sintered internal gear characterized in that it has an outer circumferential end. 9. The thickness in the thrust direction of the outer diameter portion of the flange portion is not deformable with respect to the stress of the transmission torque transmitted from the boss portion to the inner gear portion, and the gear is formed by the forming pressure during molding. A sintered internal gear, characterized in that the material is configured to have a thickness that is larger than the minimum thickness to maintain a predetermined shape. The thickness of the outer diameter portion of the flange portion in the thrust direction is not deformable with respect to the stress of the transmission torque transmitted from the boss portion to the inner tooth gear portion, and at the same time, the gear is formed by the molding pressure during molding. A sintered internal gear, characterized in that the material is configured to have a thickness that is larger than the minimum thickness to maintain a predetermined shape. 17. The thickness of the flange portion in the thrust direction of the outer diameter portion is not deformable with respect to the stress of the transmission torque transmitted from the boss portion to the inner tooth gear portion, and the gear is formed by the molding pressure during molding. A sintered internal gear, characterized in that the material is configured to have a thickness that is larger than the minimum thickness to maintain a predetermined shape. 11. The thickness of the outer diameter portion of the flange portion in the thrust direction is not deformable with respect to the stress of the transmission torque transmitted from the boss portion to the inner tooth gear portion, and at the same time, the gear is formed by the molding pressure during molding. A sintered internal gear, characterized in that the material is configured to have a thickness that is larger than the minimum thickness to maintain a predetermined shape.