JPH11342429A - Manufacture of drum with boss and, drum with boss - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a drum with boss, and the drum with boss wherein securing of high product quality and high product accuracy can be achieved by one chucking method at a low production cost. SOLUTION: This manufacturing method is composed of, the process flows such as, a material setting process, (T shape as shown by figure), wherein a disc shape pre-formed material (c) having a center hole is prepared, and the center hole and a tip end of a boss part press mold (a) are made to be matched for setting with a flow form molding machine; a boss part pressing process (square shape as shown by figure), wherein the pre-form material (c) being set with the machine is pressurized by using the boss part pressing mold (a) in a shaft direction for forming the center hole into the boss hole protruding in the shaft direction and, a drum part flow forming process, (truncated chevron shape as shown by figure), wherein the material (c) having a boss part being press-formed is left as is on the forming machine so as to generate a plastic deformation in the material (c) for pouring the material into a die by hazing of an outside forming roller (d), while the roller (d) and flow forming die (b) are made a relative movement in the shaft direction, resulting in forming of the drum part, which have an inner teeth at inner face. The drum D having a boss is thus manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a method of manufacturing a bossed drum applied as a clutch drum of a multi-plate clutch of an automatic transmission and a bossed drum manufactured by the method.

[0002]

2. Description of the Related Art Hitherto, as a method of manufacturing a bossed drum, a method described in Japanese Patent Publication No. Hei 8-20004 has been known.

In this conventional manufacturing method, as shown in FIG. 11 (a), a bossed preform material having a boss portion formed in advance is prepared, and as shown in FIG. 11 (b), the preform material is prepared. While the forming roller and the flow forming mold are moved relative to each other in the axial direction with respect to the forming margin of the outer peripheral part, plastic deformation is caused to flow into the mold by ironing with the roller, thereby forming a drum part having internal teeth on the inner surface. This produced a bossed drum.

[0004]

However, in the conventional method of manufacturing a bossed drum, a bossed preform material having a boss portion formed by hot forging is prepared in advance, and only the drum portion is prepared. Because it is a method of flow forming molding, it takes a lot of man-hours to manufacture the preform material, and the production process of the preform material and the flow forming molding process are independent processes, and the transportation and setting of intermediate products However, there is a problem in that a large number of man-hours are required, and the product unit price becomes high.

In addition, when setting the preform material in a flow forming molding machine, it takes time and effort to carefully align the center of the preform, and the center is set in a state where the axis is shifted. In this case, the axis of the boss and the axis of the internal teeth of the drum may be misaligned, and if the bossed drum is used as the clutch drum of a multi-plate clutch of an automatic transmission, the smooth axis of the clutch plate and clutch piston may be reduced. If the directional movement is not ensured, the uneven wear of the plate and the sliding resistance of the piston increase, so that a desired fastening force rising characteristic cannot be obtained.

Here, the flow forming molding will be described. In the flow forming, a material is set in a mold, the material is rotated together with the mold, and the material is moved along the mold while keeping the pressing of the forming roller against the forming portion. This means that the forming roller is relatively moved, and the material extruded by the ironing by the roller is formed while being poured into a mold.

Therefore, if this flow forming is adopted in the production of a drum, there is no springback in the elastic deformation region as in press molding, and the spline internal teeth can be formed with high precision equivalent to the machining precision. Work hardening is large due to plastic working, and fiber flow phenomena such as landslide and miniaturization of metal structure crystals are utilized, so mechanical properties (tensile strength, toughness, fatigue strength) are higher than material strength There is an advantage.

An object of the present invention is to provide a method of manufacturing a bossed drum and a bossed drum which achieves low production cost, high product quality, and high product accuracy by a one-chucking method. Is to provide.

[0009]

[Means for Solving the Problem] [Solution 1] The solution 1 of the above-mentioned problem (Claim 1) is, as shown in the claim correspondence diagram of FIG. Is a method for manufacturing a bossed drum by a flow forming molding machine arranged coaxially opposed to each other, wherein a disk-shaped preform material c having a center hole is prepared in advance,
A material setting step (a) in which the center hole of the preform material c and the tip of the boss press die a coincide with each other to set the preform material c in the flow forming molding machine. A boss pressing step of forming a boss protruding in the axial direction with the center hole as the boss hole by pressing in the axial direction (b), and the material c having the press-formed boss is set in the forming machine A drum portion for forming a drum portion having internal teeth on its inner surface by causing plastic deformation to flow into the die by ironing by the roller d while relatively moving the outer forming roller d and the flow forming die b in the axial direction; Flow forming process (c),
It is characterized by having. (Solution 2) The solution 2 of the above-mentioned problem (Claim 2) is:
As shown in the claim correspondence diagram of FIG. 1, in the method of manufacturing a bossed drum according to claim 1, the drum part flow forming step (c) comprises forming a drum part having a piston sliding surface together with internal teeth on an inner surface. Following the drum portion flow forming step (c), the inner forming roller e is moved axially relative to the flow forming mold b along the inner surface of the boss portion, and the outer surface has a piston sliding surface. A boss flow forming step (d) for forming a boss is added. (Solution Means 3) Solution Means 3 (Claim 3) of the above problem is:
In a bossed drum having a boss portion having a piston sliding surface on an outer surface and a drum portion having a piston sliding surface together with internal teeth on an inner surface, the boss portion and the drum portion use a single flow forming mold and have an inner flow. It is a portion formed by forming and outer flow forming. (Solution 4) The solution 4 of the above problem (Claim 4) is:
4. The boss-equipped drum according to claim 3, wherein a clutch plate is spline-fitted to the internal teeth of the drum portion so as to be slidable in the axial direction, and a clutch fastening force is applied to both piston sliding surfaces of the drum portion and the boss portion. The clutch clutch is provided as a clutch drum of a multi-plate clutch provided in the automatic transmission.

[0010]

(Embodiment 1) Embodiment 1 relates to a method for manufacturing a bossed drum according to the first and second aspects of the present invention, and a boss corresponding to the third and fourth aspects of the present invention. With drum. [Regarding Flow Forming Machine] First, a description will be given of a flow forming machine for press forming and used in the method of manufacturing a bossed drum of the first embodiment.

FIGS. 2 to 8 show a flow forming molding machine.
As shown in (1), a boss press die 1 and a flow forming die 2 capable of rotation and stroke are coaxially opposed to each other. The boss press die 1 is attached to a tip end of a piston rod 4 that can advance and retreat with respect to the case 3, and includes a center hole fitting cylindrical portion 1 a and a boss portion forming conical portion 1.
b and a boss cylindrical portion 1c. The flow forming mold 2 is fixed to the mandrel 5, and has a press relief center recess 2a, a spline tooth mold 2b, and a piston sliding surface mold 2c. The flow forming machine is provided with a material holder 6, an outer forming roller 7, a finishing outer forming roller 8, an inner forming roller 9, a product releasing tool 10, a product receiving tool 11, and the like as auxiliary equipment. . [Regarding Method of Manufacturing Drum with Boss] FIGS. 2 to 8 are process explanatory diagrams showing a method of manufacturing the drum with boss according to the first embodiment, in which a material setting step in FIG. 2 and a boss pressing step in FIG. The drum part flow forming step of FIG. 4, the drum part finishing flow forming step of FIG. 5, the press die cutting step of FIG. 6, the boss part flow forming step of FIG. 7, and the release step of FIG. . Hereinafter, each step will be described. In addition, the dashed line A in the drawing indicates a reference line.

In the material setting step, a disc-shaped preform material 20 having a center hole 20a is prepared in advance, and FIG.
As shown in FIG. 5, the center hole 20a of the preform material 20 held by the material holder 6 and the center hole fitting cylindrical portion 1a of the boss press die 1 are matched with each other and set in the flow forming machine. .

In the boss pressing step, as shown in FIG. 3, a pressing stroke is performed in a direction in which the flow forming mold 2 approaches the fixed boss pressing die 1, that is, the set preform material 20 is This is a step of forming a boss portion 21 that protrudes in the axial direction by using the center hole 20a as a boss hole by relatively applying pressure in the axial direction using the boss portion press die 1.

[0014] The drum part flow forming step includes:
As shown in FIG. 4, the flow forming mold 2 is moved in the axial direction with respect to the outer forming roller 7 whose position in the axial direction is fixed, while the material 20 having the boss 21 formed by press molding is set in the molding machine. This is a step of forming a drum portion 22 having a piston sliding surface 22b together with internal teeth 22a on the inner surface by causing the material 20 to undergo plastic deformation that flows into a mold by ironing with the outer forming roller 7 while being squeezed.

In the drum part finishing flow forming step, as shown in FIG. 5, the outer forming roller 7 is replaced with a finishing outer forming roller 8, and the roller contact surface is smoothed by the same operation as in the flow forming step. This is a step of finish forming the drum section 22. By this finish molding, the surface accuracy of the outer peripheral surface of the drum portion 22 is improved, and the outer peripheral surface of the drum portion 22 can be used as a pressure bonding surface of a band brake.

[0016] In the pressing die-cutting step, first, the case 3
While pressing the material 2 onto the material 20, only the boss press die 1 is pulled out from the boss 21, and as shown in FIG.
In this step, the flow forming mold 2 with 0 is retracted to maintain an insertion space for the inner forming roller 9 between the two molds 1 and 2.

In the boss portion flow forming step,
By inserting the inner forming roller 9 between the two molds 1 and 2 and moving the flow forming mold 2 in the axial direction toward the inner forming roller 9, as shown in FIG. This is a step of forming a piston sliding surface 21a on the outer surface of the boss portion 21 by the inner forming roller 9 relatively moving along.

In the releasing step, after the boss portion flow forming step is completed, the inner forming roller 9 is returned to the original position, and the product releasing tool 10 and the product receiving tool 11 are used.
As shown in FIG. 8, this is a step of releasing the molded product 20 ′ from the flow forming mold 2. [Regarding Drum with Boss] FIG. 9 is a cross-sectional view showing a bossed drum D according to the first embodiment manufactured by the above-described manufacturing method and further having holes and grooves formed by post-processing.
Is a boss portion, 21a is a piston sliding surface, 22 is a drum portion,
22a is an internal tooth, 22b is a piston sliding surface, 22c is a brake band crimping surface, 23 is a piston oil passage hole, 24 is a lubricating oil hole, and 25 and 26 are ring grooves.

The bossed drum D has a boss 21 having a piston sliding surface 21a on the outer surface, and internal teeth 22a on the inner surface.
The boss portion 21 and the drum portion 22 are formed by using a single flow forming mold 2 to form an inner flow forming mold (a boss 21) and an outer flow forming mold (a boss 21). It is a portion formed by the drum portion 22). [Regarding Automatic Transmission to which Drum with Boss is Applied] FIG. 10 is a sectional view showing a part of a power transmission mechanism of an automatic transmission to which the drum D with boss manufactured by the manufacturing method of the first embodiment is applied. is there.

In FIG. 10, 30 is an input shaft, 31 is a transmission case, 32 is a first multi-plate clutch, D is a bossed drum, 33 is a first clutch piston, 34 is a first clutch plate, and 35 is a second multi-plate. A plate clutch, 36 is a second clutch drum, 37 is a second clutch piston, 38 is a second clutch plate, and 39 is a brake band.

The bossed drum D according to the first embodiment is applied as a clutch drum of a first multi-plate clutch 32 provided in an automatic transmission.
a first clutch plate 34 is spline-fitted slidably in the axial direction, and an annular first clutch that applies a clutch engagement force to both piston sliding surfaces 22b and 21a of the drum portion 22 and the boss portion 21. A piston 33 is slidably provided.

Next, the function and effect will be described. [Manufacturing cost] Regarding the manufacturing cost of the bossed drum D, when compared with a bossed drum by a known method in which the drum member and the boss member are manufactured separately and the two members are integrated by welding, a separate product is obtained. Is replaced with an integrated product, and is manufactured as an integrated product by press molding and flow forming by a one-chucking method, so that the cost is reduced. That is, the manufacturing cost can be reduced by eliminating a separate manufacturing process and a welding process that requires careful work to ensure quality and accuracy.

A bossed preform material in which a boss portion is previously formed by hot forging is prepared, and compared with a bossed drum according to a conventional method in which only the drum portion is flow formed, a circle having a center hole 20a is obtained. By simply preparing the plate-shaped preform material 20 in advance, there is no need for a large number of man-hours in manufacturing the preform material, and the press forming of the boss 21 is also incorporated into the flow forming process by the one-chucking method. Since this is a series of steps, the manufacturing cost can be reduced. [Product quality] In the case of a manufacturing method using separate component welding, blowholes and pinholes are generated during electron beam welding, and the required welding strength cannot be obtained. Inevitably,
There is a problem that it is not possible to actually confirm the welding quality, and in the case of mass production, stable and high product quality without variation cannot be desired.

On the other hand, since the bossed drum D is a weldless integrated product, there is no blowhole or pinhole at the time of electron beam welding, and the quality can be absolutely checked without checking the welding quality. The product quality is assured and stable and high product quality without variation is secured. [Product accuracy] In the case of the manufacturing method using separate component welding, since the boss portion and the drum portion are subjected to electron beam welding, welding distortion caused by material heating accompanying welding cannot be avoided, and the spline teeth tilt due to welding distortion. However, the fitting gap between the clutch plate and the clutch plate cannot be kept constant due to the axial center misalignment between the boss portion and the drum portion.

On the other hand, the bossed drum D is
1 and the drum portion 22 are integrated, and the boss portion 21 and the drum portion 22 are formed by one-chucking method while maintaining the axial center alignment, so that there is no distortion or axial deviation due to welding and the inclination of the teeth. And the boss 21 and the drum 2
2 and the machining accuracy of the internal teeth 22a of the drum portion 22 is as high as that of mechanical machining by flow forming.

Therefore, when applied to an automatic transmission, smooth axial movement of the first clutch plate 34 is ensured,
There is no occurrence of uneven wear of the first clutch plate 34 due to one-side contact.

Furthermore, the two piston sliding surfaces 22b and 21a of the drum portion 22 and the boss portion 21 have the same axial center, and a high surface accuracy can be obtained by flow forming. Smooth sliding of the annular first clutch piston 33 that applies force is ensured,
It is possible to obtain a desired fastening force rising characteristic according to the supplied clutch hydraulic pressure. (Other Embodiments) In the first embodiment, an example in which the present invention is applied to a clutch drum of an automatic transmission has been described. However, if the boss portion and the drum portion are integrally provided, the clutch drum of the automatic transmission may be used. Besides, the production method of the present invention can be applied.

In the first embodiment, an example is shown in which the boss portion by press molding is further subjected to flow forming molding.
For example, just fixing the boss to the shaft member,
A boss-equipped drum that does not require high surface accuracy in the boss portion can be used as a product while the boss portion is press-formed.

[0029]

According to the method of manufacturing a bossed drum according to the first aspect of the present invention, there is provided a method of manufacturing a bossed drum by a flow forming molding machine in which a boss press die and a flow forming die are coaxially opposed to each other. A material setting step in which a disc-shaped preform material having a center hole is prepared in advance, and the center hole of the preform material is matched with the tip of the boss portion press die to set the flow forming molding machine. A boss pressing step of forming a boss protruding in the axial direction with the center hole as a boss hole by pressing the set preform material in the axial direction using a boss press, and a press-formed boss. While setting the raw material to the molding machine, move the outer forming roller and the flow forming mold relative to each other in the axial direction. And a drum flow forming process that forms a drum with internal teeth on the inner surface by inducing plastic deformation in the material, ensuring low production cost and high product quality by one chucking method. Thus, it is possible to provide a method for manufacturing a bossed drum that achieves high product accuracy.

According to the second aspect of the present invention, the first aspect is provided.
In the method for manufacturing a bossed drum described above, the drum part flow forming step is a step of forming a drum part having a piston sliding surface together with internal teeth on the inner surface, and following the drum part flow forming step, along the inner surface of the boss part. The boss portion flow forming step of moving the inner forming roller relative to the flow forming mold in the axial direction to form a boss portion having a piston sliding surface on the outer surface has been added. In addition, a piston sliding surface with high surface accuracy that ensures smooth sliding of the annular piston without post-processing can be formed.

According to a third aspect of the present invention, there is provided a bossed drum having a boss having a piston sliding surface on an outer surface and a drum having an inner tooth and a piston sliding surface on an inner surface. Is a part formed by inner flow forming molding and outer flow forming molding using one flow forming mold, achieving low production cost, high product quality and high product accuracy. A bossed drum can be provided.

According to the fourth aspect of the present invention, there is provided the third aspect.
In the bossed drum described above, the clutch plate is spline-fitted to the inner teeth of the drum portion so as to be slidable in the axial direction, and an annular ring that applies a clutch fastening force to both piston sliding surfaces of the drum portion and the boss portion. Since the clutch piston is slidably provided and applied as a clutch drum of a multi-plate clutch provided in the automatic transmission, in addition to the effect of the invention according to claim 3, in addition to the effect of the invention, along the piston sliding surface when the clutch is engaged / released. The clutch piston can slide smoothly,
The clutch plate can move smoothly along the internal teeth,
Clutch drag and plate uneven wear are prevented, and the durability durability of the clutch can be improved.

[Brief description of the drawings]

FIG. 1 is a process diagram corresponding to a claim showing a method for manufacturing a bossed drum of the present invention.

FIG. 2 is a diagram illustrating a material setting step of the method for manufacturing a bossed drum according to the first embodiment.

FIG. 3 is a view showing a boss pressing step of the method for manufacturing a bossed drum of the first embodiment.

FIG. 4 is a diagram illustrating a drum part flow forming step of the method for manufacturing a bossed drum according to the first embodiment.

FIG. 5 is a diagram illustrating a boss pressing step of the method of manufacturing the bossed drum according to the first embodiment.

FIG. 6 is a diagram illustrating a press die-cutting step of the method for manufacturing a bossed drum according to the first embodiment.

FIG. 7 is a diagram illustrating a boss portion flow forming step of the method of manufacturing the bossed drum according to the first embodiment.

FIG. 8 is a diagram illustrating a releasing step of the method of manufacturing the bossed drum according to the first embodiment.

FIG. 9 is a sectional view showing a bossed drum manufactured by the manufacturing method of the first embodiment.

FIG. 10 is a cross-sectional view showing a part of a power transmission mechanism of the automatic transmission to which the bossed drum manufactured by the manufacturing method according to the first embodiment is applied.

FIG. 11 is a view showing a method of manufacturing a conventional bossed drum.

[Explanation of symbols]

 D Drum with Boss 1 Boss Press Die 2 Flow Forming Die 7 Outer Forming Roller 9 Inner Forming Roller 20 Preform Material 20a Center Hole 21 Boss 21a Piston Sliding Surface 22 Drum 22a Internal Teeth 22b Piston Sliding Surface

Claims (4)

[Claims] 1. A method of manufacturing a bossed drum by a flow forming molding machine in which a boss portion press die and a flow forming die are coaxially opposed to each other, wherein a disc-shaped preform material having a center hole is formed. A material setting step in which the center hole of the preform material and the tip of the boss press die are prepared in advance and set on the flow forming molding machine, and the set preform material is set in the axial direction using the boss press die. Boss press process to form a boss that projects in the axial direction with the center hole as the boss hole by pressing the outer hole, and the outer forming roller and flow forming with the material having the press-formed boss set in the forming machine While the mold is relatively moved in the axial direction, the material is subjected to plastic deformation that flows into the mold by ironing with rollers, and the inner surface has internal teeth. A method of manufacturing a bossed drum, comprising: a drum part flow forming step of forming a ram part. 2. The method for manufacturing a bossed drum according to claim 1, wherein the drum part flow forming step is a step of forming a drum part having a piston sliding surface together with internal teeth on an inner surface thereof, wherein the drum part flow forming is performed. Following the process, a boss flow forming step of moving the inner forming roller axially relative to the flow forming mold along the inner surface of the boss and forming a boss having a piston sliding surface on the outer surface has been added. A method of manufacturing a bossed drum. 3. A bossed drum having a boss portion having a piston sliding surface on an outer surface and a drum portion having a piston sliding surface together with internal teeth on an inner surface, wherein the boss portion and the drum portion are one flow forming mold. A boss-equipped drum characterized in that it is a part formed by inner flow forming molding and outer flow forming molding. 4. The bossed drum according to claim 3, wherein a clutch plate is spline-fitted to the internal teeth of the drum portion so as to be slidable in the axial direction, and both piston sliding surfaces of the drum portion and the boss portion. A boss-equipped drum, characterized in that an annular clutch piston for imparting clutch engagement force is slidably provided and applied as a clutch drum for a multi-plate clutch provided in an automatic transmission.