Sizing equipment

Abstract

To provide a sizing device capable of suppressing a facility cost required for the reduction of an error in a hub outer diameter after sizing working.SOLUTION: A sizing device 1 works a hub M having a rib part and a tooth part and comprises: a die 11 supporting the outer circumferential side face of the hub; an upper punch 12 pressing the upper face of the hub to a vertical downward direction; a first lower punch 13 pressing the lower face of the tooth part to a vertical upward direction; and a second lower punch 14 supporting the lower face of the rib part, and after the upper punch 12 abuts against the rib part, the first lower punch 13 presses the lower face of the tooth part while pressing the upper face of the hub by the upper punch 12.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a sizing device. [Background technology]

[0002] When a hub having ribs and teeth is manufactured by a sintering method, the teeth may be curved in a tapered shape during the sintering process in which a sintered body is manufactured from a powder compact. Therefore, in the sintering method, it was necessary to carry out a sizing process to fine-tune the shape of the hub after the sintering process.

[0003] Normally, when performing sizing, the lower part of the sintered body is supported by a fixed die, and the upper part of the sintered body is pressed by a movable die. However, when performing sizing by pressing only the upper surface of the sintered body, the outer diameter of the hub after processing can differ between the pressed upper part and the unpressed lower part. Patent Document 1 discloses a sizing die that can reduce errors in the outer diameter of a hub after machining. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-206062 Summary of the Invention [Problem to be solved by the invention]

[0005] The sizing mold disclosed in Patent Document 1 has a die that supports the side surface of the hub and is machined into a tapered shape, which poses a problem of increasing the cost required for machining the mold.

[0006] The present invention has been made to solve these problems, and aims to provide a sizing device that can reduce the equipment costs required to suppress errors in the hub outer diameter after sizing processing. [Means for solving the problem]

[0007] A sizing device according to one aspect of the present invention comprises: A sizing device for processing a hub having a rib portion and a tooth portion, a die that supports the outer peripheral side surface of the hub; an upper punch that presses the upper surface of the hub vertically downward; a first lower punch that presses the lower surface of the tooth portion in a vertically upward direction; a second lower punch that supports a lower surface of the rib portion, After the upper punch contacts the rib portion, the upper punch presses the upper surface of the hub, while the first lower punch presses the lower surface of the tooth portion. It is a sizing device.

[0008] This configuration makes it possible to reduce the error in the outer diameter of the hub after sizing without using a tapered mold, thereby reducing the equipment costs required for sizing. [Effects of the Invention]

[0009] The present invention can provide a sizing device that can reduce the equipment costs required to reduce errors in the outer diameter of a hub after sizing processing. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic cross-sectional view showing the configuration of a sizing device according to a first embodiment. [Figure 2] FIG. 2 is a schematic cross-sectional view showing the shape of the hub before sizing. [Figure 3] FIG. 2 is a schematic cross-sectional view showing the shape of the hub after sizing. [Figure 4] 5A to 5C are schematic cross-sectional views showing the operation of the sizing device according to the first embodiment. [Figure 5] 5A to 5C are schematic cross-sectional views showing the operation of the sizing device according to the first embodiment. [Figure 6]5A to 5C are schematic cross-sectional views showing the operation of the sizing device according to the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] (First embodiment) <Configuration of sizing equipment> The configuration of the sizing device according to the first embodiment will be described in detail below with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing the configuration of a sizing device according to the first embodiment. The sizing device 1 according to this embodiment is a device for performing sizing processing on a hub having ribs and teeth, and is typically a device for performing sizing processing on a sintered and molded hub.

[0012] FIG. 2 is a schematic cross-sectional view showing the shape of the hub before sizing, and FIG. 3 is a schematic cross-sectional view showing the shape of the hub after sizing. As shown in FIGS. 2 and 3, the hub M to be machined by the sizing device according to this embodiment has a rib portion R and a tooth portion D.

[0013] As shown in Fig. 2, before sizing, the hub M has tooth portions D curved in a tapered shape. The sizing device 1 according to this embodiment processes the tapered curved tooth portions D into linear tooth portions D as shown in Fig. 3.

[0014] Returning to the explanation of Figure 1. The sizing device 1 according to the first embodiment includes a die 11 , an upper punch 12 , a first lower punch 13 , a second lower punch 14 , a third lower punch 15 , and a core rod 16 . The die 11 is a metal mold that supports the outer peripheral side surface of the hub to be sized. The upper punch 12 is a cylindrical mold with a through hole in the center, and a core rod 16 is fitted into the through hole of the upper punch 12. The upper punch 12 is a movable mold that presses the upper surface of the hub vertically downward, and continues to press until the sizing process is completed. The upper punch 12 is also sometimes called an upper punch.

[0015] The lower punches of the sizing device 1 according to the first embodiment are composed of a first, second, and third lower punches arranged from the outside to the inside. The first, second, and third lower punches may also be referred to as a lower outer punch, a lower middle punch, and a lower inner punch, respectively.

[0016] The first lower punch 13 is a movable die that presses the underside of the teeth of the hub vertically upward, and is a cylindrical die with a through hole in the center. The first lower punch 13 starts pressing the underside of the teeth after the upper punch 12 abuts on the rib portion of the hub, and continues pressing until the sizing process is completed.

[0017] The second lower punch 14 is a cylindrical die that supports the lower surface of the rib portion of the hub and has a through hole in the center. The third lower punch 15 is a cylindrical die having a through hole at the center and supports the lower surface of the hub in the region inside the rib portion. A core rod 16 is fitted into the through hole of the third lower punch 15.

[0018] The core rod 16 is a rod-shaped mold that supports the inner side surface of the hub. However, the core rod 16 is a mold that is necessary only when the hub has a through-hole in the center, and if the hub does not have a through-hole, the sizing device 1 does not have the core rod 16. When the sizing device 1 does not have a core rod 16, the upper punch 12 and the third lower punch 15 do not have a through hole.

[0019] <Sizing device operation> The operation of the sizing device according to the first embodiment will be described in detail below with reference to the drawings. 4 is a schematic cross-sectional view showing the state of the sizing device 1 at the time when the hub M is set in the sizing device 1. At the stage of FIG. 4, the hub M is not being pressed by any of the punches.

[0020] The hub M has its inner side surface supported by the core rod 16 and its outer peripheral side surface supported by the die 11. In addition, its lower surface is supported by the first, second, and third lower punches. First, the upper punch 12 presses the hub M vertically downward until the lower surface of the upper punch 12 abuts against the rib portion R. In this process, the first lower punch 13 only supports the hub M but does not press it.

[0021] 5 is a schematic cross-sectional view showing the state of the sizing device 1 at the time when the lower surface of the upper punch 12 comes into contact with the rib portion R. Because the tooth portion D is curved in a tapered shape, there is a gap near the tooth portion D at the stage shown in FIG. 5. On the other hand, because the lower surface of the rib portion R is supported by the second lower punch 14 and the upper surface is pressed by the upper punch 12, there is no gap nearby and the rib portion R is held fixed.

[0022] When the lower surface of the upper punch 12 comes into contact with the rib portion R, the first lower punch 13 then starts pressing the lower surface of the tooth portion D. However, the upper punch 12 continues to press the upper surface of the hub M. Here, it is preferable that the pressures applied by the upper punch 12 and the first lower punch 13 are approximately the same. If the pressures applied by the upper punch 12 and the first lower punch 13 are approximately the same, the error between the outer diameter of the upper part of the hub M and the outer diameter of the lower part of the hub M can be further reduced.

[0023] 6 is a schematic cross-sectional view showing the state of the sizing device 1 at the time when the sizing process of the hub M is completed. The tooth portion D is crushed by the pressure from the upper punch 12 and the first lower punch 13, most of the gaps near the tooth portion D disappear, and the tooth portion D is processed into a straight line.

[0024] In addition, since the sizing device 1 of this embodiment performs a process of crushing the tooth portion D, it is preferable that the tooth portion D before the sizing process is processed to be longer in the vertical direction than the dimensions of the finished product as a crushing allowance.

[0025] As described above, the sizing device 1 according to this embodiment applies pressure from both the top and bottom vertical directions when pressing the teeth D located on the outer periphery of the hub M, thereby reducing the error between the outer diameter of the upper part of the hub M and the outer diameter of the lower part of the hub M. This eliminates the need to use a tapered mold, and reduces the equipment costs required to reduce the error in the hub outer diameter after sizing.

[0026] The present invention is not limited to the above-described embodiment, and can be modified as appropriate within the scope of the invention. [Explanation of symbols]

[0027] 1. Sizing device 11 Dice 12 Upper Punch 13 First Lower Punch 14 Second Lower Punch 15 Third Lower Punch 16 Core Rod M Hub

Claims

[Claim 1] A sizing device for processing a hub having a rib portion and a tooth portion, a die that supports the outer peripheral side surface of the hub; an upper punch that presses the upper surface of the hub vertically downward; a first lower punch that presses a lower surface of the tooth portion in a vertically upward direction; a second lower punch that supports a lower surface of the rib portion, After the upper punch contacts the rib portion, the upper punch presses the upper surface of the hub while the first lower punch presses the lower surface of the tooth portion. Sizing device.

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