JP3662902B2 - Sizing method for specially shaped cylindrical parts - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sizing method, a sizing die, and a sizing apparatus for processing a specially shaped cylindrical part such as an internal helical gear with a non-circular hole.
[0002]
[Prior art]
An example of an internal helical gear used in an automatic transmission of an automobile is shown in FIGS. 5 (a) and 5 (b).
[0003]
The helical gear 30 has a non-circular hole 31 having a key and a key groove in a region biased toward one end (referred to as a first region). Moreover, it has a helical tooth 32 and a tooth groove 33 extending from the other end of the cylinder toward the one end side on the inner surface of another region (this is referred to as a second region).
[0004]
When the internal helical gear 30 is manufactured by a powder metallurgy method with high productivity, the sintered compact is sized and coined after the green compact is sintered.
[0005]
By the way, the sizing of the internal helical gear of the sintered product has been carried out separately by dividing the step of recompressing the first region and the step of recompressing the second region.
[0006]
The reason is that if the axial dimension L of the gear varies, the relative position of the end face of the gear and the non-circular hole shifts in the circumferential direction, and the non-circular hole is positioned relative to the core of the sizing mold. This is because there is a shift in the phase of the gear's helical teeth and the corresponding tooth gaps provided in the core, which impedes their engagement.
[0007]
[Problems to be solved by the invention]
As described above, when the sizing is performed twice, the work becomes two steps, and the productivity is lowered. In addition, two sets of molds are required, which increases the sizing cost.
[0008]
Therefore, the present invention has an object to enable sizing that has been performed in two steps in a single step.
[0009]
[Means for Solving the Problems]
In order to solve the above problems, in the present invention, the first region biased toward one end has a non-circular hole having a convex portion on the inner surface, and the other end on the inner peripheral surface of the second region following the first region. A specially-shaped cylindrical part having a protrusion and / or a groove extending by twisting with a constant lead L toward the first region side from
The core A inserted into the non-circular hole in the first region, the core B inserted into the hole in the second region and supporting the inner end face of the convex portion of the hole in the first region, and positioned so as to be relatively rotatable with respect to the core B Using the lower punch that moves relative to the axis in the lead L by relative rotation, and the upper punch and die,
(1) A process of relatively positioning the component and the lower punch that supports the other end of the component by positioning means provided corresponding to the component,
(2) A process of positioning the non-circular hole of the component with respect to the core A by rotating the positioned component and the lower punch together,
The method of sizing processing is taken through. The protrusion mentioned here includes a tooth.
[0010]
In order to carry out this method, in the present invention, the core A to be inserted into the non-circular hole in the first region of the cylindrical part to be sized, and the groove or the ridge that is twisted by the constant lead L on the outer peripheral surface are provided. A rotatable core B that engages the groove or protrusion with the twisted protrusion or groove of the lead L provided in the second region of the component and inserts it into the hole in the second region of the component; A lower punch having a convex or concave portion for positioning at the upper end, an upper punch for pressing the upper surface of the component, a die for inserting the component, and a lead L when the core B and the lower punch are rotated relative to each other. And a sizing die comprising a guide mechanism for causing relative movement in the axial direction, an upper ram for driving the upper punch of the die, a die plate for holding the die, and a core A of the die. , B and lower punch support plate A lower ram to the interposed between the support plate and the lower punch provided together also sizing device comprising a combination of actuators to push up near the top of the core B the lower punch.
[0011]
The cylindrical part sized by the method of the present invention has a positioning part with the lower punch at the other end.
[0012]
[Action]
In this invention, the core of the mold is divided into a core A that is inserted into a non-circular hole of a cylindrical part (hereinafter simply referred to as a part) and a core B that is inserted into a hole in the second region, and variations in the axial dimensions of the parts. The shift in the circumferential direction of the relative positions of both end faces caused by the above is absorbed by the relative rotation of the core A and the core B.
[0013]
That is, when the lower punch and the component are relatively positioned and rotated together, the cores A and B rotate relative to each other, and the relative rotation between the two end faces of the component caused by the relative rotation is absorbed. A non-circular hole is positioned with respect to the core A.
[0014]
When relative rotation occurs between the core B and the lower punch, an axial relative movement of the lead L occurs between the core B and the lower punch, and the phase shift between the meshed portions of the core B and the lower punch occurs. Is prevented. Therefore, the positioning state of the core B with respect to the lower punch is not collapsed, and the component positioned with the lower punch is positioned not only with respect to the core A but also with respect to the core B.
[0015]
For this reason, sizing in one step becomes possible.
[0016]
The mold according to the present invention, which enables sizing in one step, allows both the lower punch and the core B to be rotated, positions both with a guide mechanism, and positions the lower punch and parts in this state. Since the component is positioned with respect to the core B, positioning is easy.
[0017]
In addition, the actuator can be set between the lower punch and the lower punch support plate by pushing up the lower punch to a position substantially the same as the upper end of the core B, so that positioning is further facilitated.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, with reference to FIG.1 and FIG.2, embodiment of the sizing method of this invention, the metal mold | die for sizing, and a sizing apparatus is demonstrated. Here, as an example of the sizing object, an internal helical gear 30 (hereinafter simply referred to as a gear) shown in FIG. 5 is taken as an example.
[0019]
In the figure, 1 is an upper punch that is pushed down by the upper ram 2, 3 is a lower punch that supports the other end of the gear 30, 4 is a lower punch support plate, 5 is a lower ram that raises and lowers the lower punch support plate 4, and 6 is a lower punch. 3 is a cylinder actuator provided between the lower punch support plate 4 and 7 is a die, and 8 is a die plate for holding the die 7.
[0020]
Independent cores A and B are arranged inside the lower punch 3. The core A is directly connected to the lower ram 5, while the core B is rotatably connected to the lower ram 5 via a thrust bearing 9.
[0021]
The lower punch 3 is also rotatably supported via a thrust bearing 10.
[0022]
The core A has a large-diameter portion 11 that fits into the non-circular hole 31 of the gear 30 at the upper end. The core B is arranged on the outer periphery of the small-diameter portion of the core A and supports the inner end face of the convex portion 34 provided in the first region of the gear 30 at the upper end. On the outer periphery of the core B, there are provided a tooth 12 and a tooth groove 13 which are fitted and meshed with a tooth 32 and a tooth groove 33 (see FIG. 3A) of the gear 30.
[0023]
Further, the inner teeth of the lower punch 3 arranged on the outer side of the core B are engaged with the helical teeth 12 and the tooth grooves 13 of the core B so as to be engaged with each other. 15 (see FIG. 3B), and further, a positioning projection 17 for engaging with a recess 35 (see FIG. 4) formed at the other end of the gear 30 is provided at the upper end of the lower punch 3. . There may be only one convex portion 17. In this case, the convex portion 17 is provided at a position that avoids the equally divided points in the circumferential direction so that the gear 30 and the lower punch 3 are positioned at only one point.
[0024]
In addition, the inner surface side of the upper punch 1 has a shape that fits and fits to the outer periphery of the large-diameter portion 11 of the core A, and the relative relationship between the cores A and B is between the large-diameter portion 11 of the core A and the core B. A thrust bearing 18 is provided for smooth rotation.
[0025]
As shown in FIG. 1, the sizing mold and sizing apparatus configured as described above drive the lower ram 5 to project the cores A and B and the lower punch 3 above the die 7. At this time, the lower punch 3 is pushed upward by the cylinder actuator 6 until the upper end and the surface position of the core B are substantially aligned to facilitate positioning and setting of the gear 30.
[0026]
In this state, the gear 30 is positioned by the concave portion 35 and the convex portion 17 shown in FIG. 4 and placed on the upper end of the lower punch 3. Next, the lower punch 3 and the gear 30 are rotated together, and the non-circular hole 31 of the gear 30 is guided by the guide 36 provided in the core A and positioned with respect to the core A. At this time, if there is an error in the axial dimension of the gear 30, the core B and the lower punch 3 move relative to each other in the axial direction by an amount corresponding to the error amount. Relative rotation corresponding to the direction displacement amount occurs.
[0027]
When the above preparation is completed, the upper punch 1, which is positioned relative to the core A, is lowered, and when the gear 30 is sandwiched by the upper and lower punches 1, 3, the cylinder punch 6 is pushed back by the force of the upper ram 2 while lower punch 3 is lowered and the convex portion 34 of the gear 30 is pushed into the outer periphery of the large-diameter portion 11 of the core A. Thereafter, the cores A and B and the lower punch 3 are lowered together with the lower ram 5, and the entire gear 30 pressurized by the upper punch 1 is guided to a guide 37 provided in the die 7 in the die 7 as shown in FIG. And press to compress for sizing. At the time of the pushing, the core B engaged with the helical teeth 32 of the gear 30 rotates due to the influence of the helical lead, and the gear 30 does not rotate.
[0028]
It should be noted that the method of the present invention can be applied to parts provided with lead grooves or lead protrusions instead of helical teeth, parts provided with convex portions such as splines on the outer periphery instead of non-circular holes, It can also be applied to the sizing of parts (external helical gears) with teeth on the outer peripheral surface.
[0029]
Parts with protrusions instead of non-circular holes on the outer periphery or parts with helical teeth or alternative lead grooves, lead ridges, etc. on the outer periphery of the second area are at least the lower punch and the outer lower punch. Sizing is performed using a die divided into two punches. The cores A and B do not need to be made independent unless the teeth or the like are formed on the inner surface of the component. Even in the sizing of such parts, the lower punch and the parts are positioned with respect to each other by providing positioning means between them. Further, the inner and lower punches are pushed up to a height position where the parts can be easily positioned and set by the cylinder actuator.
[0030]
【The invention's effect】
As described above, according to the method, mold and apparatus of the present invention, the core A in which the part to be sized and the lower punch supporting the part are positioned with respect to each other, and then the part and the lower punch are rotated together to be independent. , B causes relative rotation, and the relative rotation of the cores A and B absorbs the deviation of the relative position in the circumferential direction of both end surfaces due to the variation in the axial dimension of the component. The sizing operation that has been performed can be completed in one time, and productivity is improved.
[0031]
In addition, the number of molds that conventionally required two sets becomes one set, and the sizing cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of a sizing die and sizing device according to the present invention. FIG. 2 is a view showing a state where an internal helical gear is compressed. (B) Partial enlarged cross-sectional view showing the meshed state of the lower punch and the core B. FIG. 4 is a view showing an example of mutual positioning means of the lower punch and the gear. End view showing an example (internal helical gear) (b) Cross section of the same gear [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Upper punch 2 Upper ram 3 Lower punch 4 Lower punch support plate 5 Lower ram 6 Cylinder actuator 7 Die 8 Die plates 9, 10, 18 Thrust bearing 11 Large diameter part 12, 14 Helical teeth 13, 15 Tooth groove 16 Guide mechanism 17 Protrusions A and B for positioning Core 30 Internal helical gear 31 Non-circular hole 32 Helical teeth 33 Tooth grooves 34 Convex parts 35 Concave parts 36 Guide for core A 37 Guide for die

Claims (4)

The first area biased toward one end has a non-circular hole with a convex portion on the inner surface, and is twisted with a constant lead L from the other end toward the first area on the inner peripheral surface of the second area following the first area. Specially shaped cylindrical parts having ridges and / or grooves extending
The core A inserted into the non-circular hole in the first region, the core B inserted into the hole in the second region and supporting the inner end face of the convex portion of the hole in the first region, and positioned so as to be relatively rotatable with respect to the core B Using the lower punch that moves relative to the axis in the lead L by relative rotation, and the upper punch and die,
(1) A process of relatively positioning the component and the lower punch that supports the other end of the component by positioning means provided corresponding to the component,
(2) A process of positioning the non-circular hole of the component with respect to the core A by rotating the positioned component and the lower punch together,
Sizing method for specially shaped cylindrical parts that undergo sizing treatment via The core A to be inserted into the non-circular hole in the first region of the cylindrical part to be sized, and the groove or ridge twisted by the constant lead L on the outer peripheral surface, and the groove or ridge in the second region of the part A rotatable core B that engages with a ridge or groove having a twist of the provided lead L and is inserted into a hole in the second region of the component, and a positioning convex portion or concave portion that is engaged with the component are provided at the upper end. A sizing metal comprising a lower punch, an upper punch for pressing the upper surface of the component, a die for inserting the component, and a guide mechanism for causing the core B and the lower punch to move in the axial direction relative to the lead L when they rotate relative to each other. Type. A mold according to claim 2, an upper ram for driving an upper punch of the mold, a die plate for holding a die, a lower ram for raising and lowering the cores A and B of the mold and a support plate for the lower punch. A sizing device comprising a combination of actuators interposed between the support plate and the lower punch to push the lower punch to near the upper end of the core B. A specially shaped cylindrical part such as an internal helical gear with a non-circular hole sized by the method according to claim 1, wherein the other end has a positioning part with a lower punch.

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