JP5361669B2 - Carrier plate in planetary gear mechanism carrier - Google Patents

Description

  The present invention relates to a carrier plate constituting a carrier of a planetary gear mechanism used for an automobile transmission or the like.

  As a carrier of a planetary gear mechanism used for an automobile transmission or the like, there is a carrier composed of a carrier base and a carrier plate. The carrier plate is provided with legs that are spaced at equal intervals in the circumferential direction, and the legs are welded and fixed to the carrier base. Therefore, a space part that is spaced apart in the circumferential direction is formed between the opposed surfaces of the carrier plate and the carrier base, and this space part constitutes a pinion gear storage part. There is a press-molded product made from a metal plate as the carrier plate. In this case, the plate consists of a disk-shaped portion that becomes the base of the carrier plate by pressing and a radially extending portion that becomes the leg of the carrier plate. The intermediate material is punched out, and the radial portion of the intermediate material is press-bended to form a leg. Since it is difficult to make the base plane at the transition from the leg by bending as it is, a notch is provided on the peripheral surface at the transition part to the radially extending part in the intermediate material so as to block the influence of the bending process. (Patent Document 1).

There is also a carrier plate made of a sintered product (Patent Document 2). In the case of a sintered carrier plate, the leg portion connecting the base portion to the carrier base is configured to have a considerably large dimension not only in the circumferential direction but also in the radial direction so as to have sufficient rigidity.
JP-A-8-300084 JP-A-7-208585

  The presence of a notch as a press-formed product inevitably causes a decrease in bending rigidity in the circumferential direction.In relation to the required specifications such as torque increase, the size of the leg in the circumferential direction is increased, If measures are taken to increase rigidity by increasing the wall thickness, there is a problem that the pinion gear cannot be stored in the layout if it is the same size, and it may be necessary to increase the size and the weight will increase. The demand for space saving and weight reduction cannot be met.

  On the other hand, in the case of a sintered product, there is no problem in terms of rigidity, but the cost is a considerable disadvantage compared to a pressed product.

  The present invention has been made in view of the above-mentioned problems, and has high rigidity substantially equal to that of a sintered product while maintaining the thickness and leg width of the plate material despite being a press-formed product from the plate material. The purpose is to realize.

According to the present invention, the carrier plate is a press-formed product of a plate material fixed to the carrier base and constituting the carrier of the planetary gear mechanism, and the carrier plate is recessed toward the carrier base at the base and the outer peripheral edge of the base. A press-molded portion comprising a pair of side wall surfaces spaced apart in the circumferential direction and a bottom wall surface connecting between the pair of side wall surfaces, and the leg portion with respect to the general surface of the base portion A carrier plate is provided that extends one step down from the outer peripheral end of the bottom wall surface of the press-formed part, and that the base part substantially maintains its outer diameter and is connected to the leg part via the press-formed part. .

  And in the carrier plate press molding method of the present invention, an intermediate material consisting of a disk-shaped part that becomes the base part of the carrier plate by pressing and a radially extending part that becomes the leg part of the carrier plate is obtained from the plate material. The carrier is formed by cut-molding and press-molding a step in the connection portion of the intermediate material with the radially extending portion in the outer peripheral portion of the disk-shaped portion, and then press-bending the extension portion of the intermediate material extending from the step. Mold into a plate.

  By press-molding a step in the extension of the leg on the outer periphery of the base of the carrier plate, the circumferentially spaced side walls that form the step become ribs, and the leg extends from the bottom wall of the step. Combined with the configuration, the rigidity of the carrier plate in the circumferential direction can be increased. Therefore, even if the wall thickness is reduced or the width of the legs is reduced, the required rigidity can be ensured, the degree of freedom in layout of pinion gears and the like is increased, and the possibility of application to many vehicle types is expanded. In addition, the weight of parts can be reduced.

FIG. 1 is a perspective view of a planetary gear carrier having a carrier plate according to the present invention. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. FIG. 3 is a plan view of an intermediate material which is a press product for obtaining the carrier plate of FIG. FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 3, and shows steps (a), (b), and (c) when the carrier plate in FIG. 1 is pressed from an intermediate material. FIG. 5 is a graph schematically showing the results of a simulation experiment regarding the step depth and the displacement with respect to torque for the planetary gear carrier provided with the carrier plate of the invention.

  The planetary gear carrier of the present invention is used for an automatic transmission of an automobile, etc. FIG. 1 is a perspective view showing an example thereof. The carrier for planetary gears includes a carrier base 10 and a carrier plate 12, and the carrier base 10 and the carrier plate 12 are formed by pressing from a plate material having a predetermined thickness, and are integrated as a carrier by joining such as welding. The carrier base 10 includes a center hole 10 'through which a center axis (not shown) of the planetary gear mechanism is inserted at the center, and a tooth portion 10-1 is formed on the outer periphery. The carrier of this embodiment is of a type in which the teeth 10-1 on the outer periphery of the carrier base 10 are engaged with the internal teeth (splines) of a clutch drum (not shown) provided on the outer side, but the present invention is of this type. Of course, the present invention can also be applied to a carrier base itself having a drum shape with an outer peripheral portion projecting into a cylindrical shape. The carrier plate 12 includes a central hole 12 ′, and includes a disk-shaped base portion 14 and three leg portions 16 bent from the outer peripheral surface of the base portion 14 toward the carrier base 10. At a position facing the three leg portions 16, the carrier base 10 forms three arcuate holes 20, corresponding leg portions 16 are inserted into the respective arcuate holes 20, and the insertion portions are welded. The carrier base and the carrier plate are assembled as a carrier. In this assembled state, the space between the carrier base 10 and the carrier plate 12 is divided into three spaces in the circumferential direction by the three leg portions 16, and each space serves as a storage space for a pinion gear (not shown). The pinion gear is pivotally supported between the carrier base 10 and the carrier plate 12. In this embodiment, the pinion gear has a so-called double gear configuration, and a pinion gear in the form of a helical gear that meshes with each other is mounted in each pinion gear storage space. Two pinion shaft support holes are provided for each pinion gear storage space, such as 10A, 12A; 10B, 12B. The pinion support shafts are inserted and supported by the pinion shaft support holes 10A, 12A; 10B, 12B formed in the carrier base 10 and the carrier plate 12. In this embodiment, the center holes 10 ′ and 12 ′ of the carrier base and the carrier plate are flawed holes, and the center axis (not shown) is freely inserted, but the carrier base and the carrier plate are used as a planetary gear mechanism. Needless to say, the present invention is naturally applicable to a type in which a single-sided or double-sided boss portion having a spline formed on the inner periphery or outer peripheral portion is integrally formed at the center of the shaft and the spline is fitted to the center shaft. .

  According to the present invention, as shown in FIG. 1, the base portion 14 of the carrier plate 12 has a step 18 toward the carrier plate 10 at a portion close to the outer peripheral portion. That is, each step 18 is located at a connection portion between the base portion 14 and the leg portion 16. That is, the step 18 is opened outward in the radial direction, and each leg portion 16 extends toward the carrier base 10 from the opening end (a portion that is lowered by one step from the general surface of the base portion 14). It has become. In this embodiment in which three legs 16 are provided, three steps 18 are provided at intervals in the circumferential direction. In the radial direction, each step 18 starts from a portion somewhat close to the center hole 12 in the base portion 14 of the carrier plate 12 and extends to the outer peripheral portion of the base portion 14. Although it is somewhat narrower than the width of the portion 16, it has a shape expanding outward, and is slightly wider than the width of the leg portion 16 at the outer peripheral portion. And since the level | step difference 18 continues to the leg part 16, the outer surface of radial direction is open | released, the flat bottom wall surface 18A, the side wall surface 18B extended in the circumferential direction of an inner side, and the circumferential direction opposed on the outer side A pair of radially extending side wall surfaces 18C are provided, and among these side wall surfaces 18A, 18B, 18C, the inner circumferentially extending side wall surface 18B is connected to the bottom wall surface 18A with a relatively gentle slope. The pair of side wall surfaces 18C that extend in the circumferential direction and are opposed to each other in the circumferential direction are rounded at the connection portion with the base portion 14, but are configured to be continuous with the bottom wall surface 18A while being substantially upright. Accordingly, the pair of side wall surfaces 18C facing each other in the circumferential direction are connected to the leg portion 16 via the bottom wall surface 18A, and this configuration increases the circumferential rigidity of the carrier plate 12 as will be described later. Is possible.

  In the carrier plate 12 of this embodiment, the base portion 14 is connected to the leg portion 16 through the step 18 (side wall surface 18C) with the outer periphery thereof, and is not provided with a notch portion in the carrier plate of the conventional press product, but is bent. It is possible to provide a small notch in the base part of the leg for improving efficiency.

  Next, the press forming method of the carrier plate 12 according to the present invention will be described. A steel plate as a raw material has a predetermined thickness, and a disc-shaped portion serving as a base portion of the carrier plate from the steel plate as shown in FIG. 30 and a radially extending portion 32 serving as a leg portion of the carrier plate, and an intermediate material having an opening 34 serving as a center hole 12 ′ of the carrier plate 12 at the center is pressed (see FIG. 4 (a)). ).

  As a next step, a step is press-formed by pressing at a connection site with the radially extending portion 32 in the outer peripheral portion of the disc-like portion 30 in the intermediate material. The contour shape from the upper surface of the step to be attached by the two-dot chain line 36 is shown, while FIG. 4B shows the state after the press forming of the step 36, and the bottom wall surface at the step 18 of the carrier plate 12 as a product. As for 18A and side wall surface 18B and 18C, bottom wall surface part 36A used as bottom wall surface 18A, and side wall surface part 36B and 36C are shape | molded.

  After the step forming, the intermediate material extending portion 32 extending from the bottom wall surface portion 36A of the step is press-bended so that the outer diameter surface is flush (the portion after the press bending is shown in FIG. 4 (c)). To do. Thereby, the carrier plate 12 of this invention is obtained.

  In the present invention, the base part of the leg portion extending from the support plate (the part shown by p in FIG. 3 as the material before the bending process) is slightly cut out (from the carrier plate as the product) from the viewpoint of easy bending. A size that does not substantially affect the rigidity in the circumferential direction), which is also included in the present invention.

  In the carrier plate of the present invention, the rigidity in the circumferential direction can be increased by providing a step 18 by press molding at the connection portion with the leg 16 at the outer peripheral portion of the base 12 of the carrier plate. That is, a circumferential torque is applied to the carrier 12 from the pinion gear, and for this circumferential torque, a pair of side wall surfaces 18C that form a step 18 and that are separated in the circumferential direction pass through the bottom wall surface 18A. Therefore, the structure connected to the leg portion 16 functions as a tension, which contributes to an increase in rigidity. FIG. 5 schematically shows the result of a simulated experiment using the finite element method with a solid line a in the circumferential direction when the width of the leg portion 16 is constant and the depth of the step is changed. The attached points are the measurement points, and it can be seen that as the step is deepened, the amount of displacement decreases, that is, the rigidity against torque increases. On the other hand, in the case of a carrier plate having a sintered structure as in the prior art (Patent Document 2) (the width of the leg is the same), the amount of displacement in the circumferential direction by a simulation experiment using the finite element method is indicated by a two-dot chain line b. (In the case of a sintered structure, there is no step and the data is one). From FIG. 5, by selecting an appropriate step size, the amount of displacement can be at least equal to or smaller than that of the sintered structure, and the desired torque rigidity value can be obtained. Therefore, the available space can be made larger than the sintered structure, which is advantageous in terms of cost and weight.

DESCRIPTION OF SYMBOLS 10 ... Carrier base 12 ... Carrier plate 14 ... Carrier plate base 16 ... Carrier plate leg 18 ... Carrier plate step 18A ... Step bottom wall surface 18C ... A pair of side wall surfaces 30 facing the circumferential direction of the step ... Plate material Intermediate material for the molding of the carrier plate of the invention from

Claims (1)

A carrier plate, which is a press-formed product of a plate material fixed to a carrier base and constituting a carrier of a planetary gear mechanism, the carrier plate having a base portion and a leg portion bent toward the carrier base at an outer peripheral edge of the base portion. The base portion is formed by pressing at a connection portion with the leg portion so as to be recessed toward the carrier base side, and includes a pair of side wall surfaces spaced in the circumferential direction and a bottom wall surface connecting the pair of side wall surfaces. A press-molded portion; the leg portion is lowered from the general surface of the base portion by one step and extends from an outer peripheral end of the bottom wall surface of the press-molded portion; and the base portion substantially maintains its outer diameter. A carrier plate connected to the leg portion via a press-molding portion .

Images