JPH0618660Y2 - Drum punching device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION << Industrial Application Field >> The present invention relates to a drum punching device for punching and forming a concentric hole on the bottom surface of a bottomed cylindrical drum based on the inner circumference.

<< Prior Art >> For example, a clutch drum in an automatic transmission forms a bottomed cylindrical drum by press-drawing a metal plate, and then forms concentric holes in the bottom surface of the drum by press punching. When punching and forming this hole,
It is necessary to make the inner circumference of the drum and the concentricity of the hole extremely high with reference to the inner circumference of the cylindrical portion of the drum.

In the conventional apparatus for punching a drum as described above, a drum, which is a work, is fitted exactly on the outer periphery of a die for punching holes, and by this fitting, the drum is positioned and set in a mold with the inner periphery as a reference. With this structure, in order to sufficiently increase the concentricity between the inner circumference of the drum and the punching hole,
The fitting clearance between the outer circumference of the die and the inner circumference of the drum should be set to almost zero, and the fitting should be made so hard that the inner circumference of the drum is slightly pressed into the outer circumference of the die. Position accuracy is reduced).

<Problems to be solved by the invention> As described above, if the inner circumference of the drum is tightly fitted to the outer circumference of the die, the drum cannot be smoothly attached to and detached from the mold, and the inner portion of the drum is not easily attached and detached. The peripheral surface is scratched. Therefore, the clearance of the fitting portion cannot be reduced so much that the concentricity of the punched hole with respect to the inner circumference of the drum cannot be sufficiently high.

The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to easily attach and detach the drum to and from the mold, without damaging the drum, and to further improve the inner circumference of the drum and the punching hole. (EN) Provided is a drum punching device capable of sufficiently increasing the concentricity with the drum punching device.

<< Means for Solving the Problems >> Therefore, in this invention, a plurality of centering members that are movable by being biased in a direction that radially expands from the center of the mold are attached to the mold that enters the inner circumference of the drum. Further, an interlocking mechanism is provided which displaces the centering member toward the center when the upper and lower molds are separated from each other and displaces the centering member radially outward when the two molds approach each other to contact the inner peripheral surface of the drum. It was

<< Operation >> Since the centering member is displaced toward the center when the molds are separated from each other, the drum can be easily set in this portion. Although the position of the drum is not accurately determined in the set state, when the mold approaches in the punching process of the hole, the centering member is displaced radially outward and abuts on the inner peripheral surface of the drum. The drum is accurately positioned in the mold with reference to the inner circumference. The hole is punched in that state.

<< Embodiment >> FIG. 1 shows the configuration of the essential parts of a first embodiment of the present invention, and FIG. 2 is a schematic view showing the essential points thereof. Reference numeral 1 is a cylindrical drum with a bottom formed by press drawing. The diameter of the cylindrical part has two stages as shown in the figure, but the reference when opening a hole is the inner circumference of the small diameter part. The surface.

The punch 2 is attached to the center of the lower die holder 4, and the die 3 is attached to the upper die holder 5 correspondingly. A hole is punched out at the center of the bottom portion of the drum 1 by the punch 2 and the die 3.

As shown schematically in FIG. 2, the drum 1 is set in a lower mold with its bottom surface facing up. In this lower mold, three centering members 6 also serving as work supports are provided around the punch 2. It is arranged at intervals. As will be described in detail below in sequence, the centering member 6 is set in the groove of the lower die holder 4 and is movable not only in the radial direction around the punch 2 but also in the vertical direction. Further, when the upper and lower molds are separated from each other, the centering member 6 is displaced toward the center, and in this state, the three centering members 6 and the punches 2 are set so as to cover the inverted drum 1. To do. Then, when the upper die holder 5 moves down together with the ram, the centering members 6 are displaced radially outward by the interlocking mechanism described below, and the three centering members 6 are spring-loaded on the inner peripheral surface of the drum 1. Contact and position the drum 1. At this time, the center of the punch 2 and the center of the inner peripheral surface of the drum 1 coincide with each other with high accuracy.

Next, a specific configuration of the centering member 6 will be described in detail with reference to FIG.

An elevating block 7 is vertically slidably set in the groove of the lower die holder 4 and is constantly urged upward by a spring 8. An L-shaped centering member 6 is set on the lifting block 7. There is a recess 7a on the upper surface side of the elevating block 7 into which the projecting piece 6a of the centering member 6 is inserted, and a spring 9 is mounted between the two, and this spring 9 causes the centering member 6 to always be attached radially outward. It is energized. The position of the centering member 6 biased outward is restricted by the cam plate 1 fixed to the outer peripheral portion of the upper surface of the lower mold holder 4.
It is 0. The corner portion of the outer end portion of the centering member 6 has an inclined surface 6b, and the inclined portion 10a of the inner corner of the lower end of the cam plate 10 has an inclined surface 10a.
The inclined surface 6b of the centering member 6 is pressed against the inclined surface 10a of the cam plate 10 by the force of the spring 9 so that the position of the centering member 6 is determined. At this time, the work set portion 6c of the centering member 6 (a portion that contacts the inner peripheral surface of the drum 1) is located closer to the center than the inner peripheral surface of the drum 1.

Further, a push pin 11 is provided so as to project downward at a predetermined position of the upper die holder 5, and the push pin 11 is an upper surface of an end portion of a horizontal portion of the centering member 6 while the upper die holder 5 is descending. Is pushed down.

In the above structure, the drum 1 is placed upside down on the three centering members 6 and the punch 2 at the center thereof with the upper die and the lower die separated from each other. At this time, there is a large clearance between the work set portion 6c of the centering member 6 and the inner peripheral surface of the drum 1, so that the drum 1 can be easily set. Next, when the upper die holder 5 comes down,
First, since the push pin 11 presses each centering member 6 downward, the spring 8 bends and the centering member 6 and the elevating block 7 descend together with the push pin 11. At the same time, the centering member 6 is displaced outward by the force of the spring 9 along the inclined surface 10a of the cam plate 10. That is, all the three centering members 6 are displaced by the force of the spring 9 so as to expand outward, and each work set portion 6c is moved to the drum 1.
And the drum 1 is positioned concentrically with the punch 2 on the basis of the inner circumference.

The drum 1 is positioned in the lowering process of the upper die holder 5 as described above, and the punching process by the punch 2 and the die 3 is performed in the final stage of lowering the upper die after the drum 1 is positioned. When the upper die holder 5 is raised, the spring 8 and the spring 9 return to the state shown in FIG.

FIG. 3 shows the essential parts of a second embodiment of the present invention. Second
The centering member 60 in the embodiment is the lifting block 6
1 and the spring portion 62 are integrally formed. The elevating block 61 can move vertically in the groove of the lower die holder 4, and is constantly urged upward by the spring 8. Further, the spring portion 62 is arranged so that the work set portion 64 of the centering member 60 is always displaced outward.
0 is urged.

In a state where the upper and lower molds are separated from each other and the push pin 11 is not pushing down the elevating block 61, the centering member 60, which is urged upward and outward by the force of the spring 8 and the spring portion 62, has an inner end. The side locking portion 63 is positioned in contact with the step portion 2a of the punch 2.
In this state, the work set portion 64 is located closer to the center than the inner peripheral surface of the drum 1. In this state, the drum 1 is set so as to cover the three centering members 6.

Next, the upper die holder 5 comes down and first the push pin 11
When the elevating block 61 is pushed downward, the centering member 60 is displaced downward together with the elevating block 61, so that the centering member 60 is tilted to the left around the contact point with the stepped portion 2a of the punch 2. It is displaced by the force of. That is, the work set portion 64 is displaced so as to spread outward in the radial direction while descending, and the three work set portions 64 are brought into contact with the inner peripheral surface of the drum 1 to position them. In the positioned state, the punch 2 and the die 3 punch and form holes in the bottom surface portion of the drum 1.

<< Problems to be Solved by the Invention >> As described in detail above, in the drum punching device according to the present invention, a plurality of centering members located on the inner circumference of the drum in the process of approaching the molds. Spread radially, and these centering members abut against the inner peripheral surface of the drum to position it. Then, in the positioned state, holes are punched on the bottom surface of the drum by a punch and a die.
Therefore, when the drum is set with the molds separated, there is a large clearance between the centering member and the inner circumference of the drum, so that the mounting and dismounting of the drum to the mold can be performed very easily, and the hard fitting As a result, the inner surface of the drum is not scratched. Of course, since each centering member accurately positions the inner peripheral surface of the drum as a reference, the concentricity between the inner peripheral surface of the drum and the punched hole becomes extremely high.

[Brief description of drawings]

FIG. 1 is a half sectional view of a drum punching device according to a first embodiment of the present invention, FIG. 2 is a schematic view showing only essential points of the same embodiment, and FIG. 3 is a drum punching device according to a second embodiment of the present invention. FIG. 1 ... Drum (work), 2 ... Punch, 3 ... Die, 4 ... Lower mold holder, 5 ... Upper mold holder, 6 ... Centering member, 7 ... Lift block, 8, 9 ... Spring, 10 ... Cam plate 11 ... Push pin 60 ... Centering member, 61 ... Lifting block 62 ... Spring part, 63 ... Locking part

Claims (1)

[Scope of utility model registration request] 1. A device for punching and forming a concentric hole on the bottom surface of a bottomed cylindrical drum, which is attached to a mold on the side of entering the inner circumference of the drum, and is radial from the center of the mold. When the upper and lower molds are separated from each other, the centering members are displaced toward the center when the upper and lower molds are separated from each other, and the centering members are displaced outward in the radial direction when the two molds approach each other. A drum punching device, comprising: an interlocking mechanism for contacting the inner peripheral surface of the drum.