JPS5839013B2 - Manufacturing method of bracket for rotating machine - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a method of manufacturing a sheet metal bracket for a rotating machine, and in particular, it aims at reducing processing costs by ensuring the required accuracy of fitting parts such as bearing housing parts by press working. be.

First, in this type of conventional method, a sheet metal bracket that has been press-formed into the required shape is pressed using a die and punch set at an appropriate ironing width to plastically deform it and finish it.

That is, in FIG. 1, 1 is a sheet metal bracket having a cylindrical bearing accommodating part 1a press-formed into the final shape, 2 is a punch inserted into the bearing accommodating part 1a by pressing with a squeeze allowance t, and 3 The outside diameter of the sheet metal bracket is regulated using a die.

Here, the sheet metal bracket 1 is formed by press-inserting the punch 2 into the bearing accommodating portion 1a, and the sheet metal bracket configured in this way is formed by pressing the punch 2 into the bearing accommodating portion 1a.
Extremely high accuracy is obtained while the sheet metal bracket 1 is being pressed, but when the sheet metal bracket 1 is removed from the mold, the internal strain stress generated inside the sheet metal bracket 1 causes the bearing housing part 1a to
caused deformation due to springback action (restoring force action), which made it impossible to secure the required accuracy and required machining.

In addition, due to the distortion generated in the pressing process during machining, unless the feed and cutting depth of the cutting tool are reduced, the shape will follow the distortion.To avoid this, a large amount of machining time is required, which significantly increases manufacturing costs. I took it seriously.

The present invention provides a novel manufacturing method to eliminate such drawbacks, and an embodiment of the present invention shown in FIGS. 2 to 5 will be described below.

That is, in FIGS. 2 to 5, 1 is a sheet metal bracket press-formed into a final shape, and 4 is a punch that is press-inserted into the sheet metal bracket bearing accommodating portion 1a, and has a convex portion 4a on the outer periphery. The above sheet metal bracket 1 is inserted when the above press is inserted.
A groove is formed on the inner surface of the bearing accommodating portion 1a.

Reference numeral 5 denotes a die for regulating the outer diameter of the bearing accommodating portion when forming the groove.

Reference numeral 1 denotes a sheet metal bracket having a groove formed by inserting a punch 4 into the plate.

In this invention configured as described above, first, the second
In the groove forming step shown in the figure, the punch 4 having the convex portion 4a is
A groove is formed on the inner surface of the bearing accommodating portion 1a of the sheet metal bracket 1, and in the ironing process shown in FIGS. 4 and 5, the ridges of the groove are removed using a cylindrical punch 2 and the groove is finished to the required inner diameter. Therefore, almost no internal stress occurs in the radial and circumferential directions.

Therefore, even if the sheet metal bracket N' is removed from the mold, the inner diameter determined by the cylindrical punch 2 can be maintained.

In the above embodiment, the case where the bearing accommodating part of the bracket 1 is processed is illustrated, but the present invention is not limited to this, and the present invention can be applied to a part that fits with other frames, etc., and further, the bearing accommodating part, Of course, it is also possible to process other fitting parts on the same axis at the same time.

As described above, according to the present invention, the groove is formed in the cylindrical fitting part by the first upper step, and the peak part of the groove is removed by the second step. Only the peaks of the grooves formed in the first step need to be machined, and the internal stress in the longitudinal and circumferential directions is greatly reduced.Therefore, the deformation of the bracket after opening the punch is also small, allowing for high-precision stamping. Processing can be performed.

More specifically, in the second step, the present invention irons only the peaks of the grooves of the fitting portion of the bearing, etc., so that the straining deformation resistance is low and the amount of spring back is small. For example, when the tolerance is required to be 20 microns, the dimensional tolerance is (0
~35 microns) was outside the tolerance range (0~1
5 microns), making it possible to more than double the accuracy in terms of dimensional tolerance.

Further, the fitting portion such as the bearing housing portion can be formed without machining, thereby significantly reducing manufacturing costs and making it possible to provide a bracket for a rotating machine with low noise.

[Brief explanation of the drawing]

FIG. 1 is a sectional view for explaining the conventional method, and FIGS. 2 to 5 are sectional views for explaining the present invention in detail. In the figure, 1 is a sheet metal bracket, 1a is a bearing housing part,
2 is a cylindrical punch, 3 and 5 are dies, and 4 is a punch having a convex portion. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] 1. In a device having a cylindrical fitting part, a first step of press-inserting a first punch having a protrusion on the peripheral edge into the cylindrical fitting part to form a groove in the fitting part; Manufactured by a second step of inserting a second cylindrical punch having an outer diameter smaller than the diameter corresponding to the peak of the groove formed in the step into the fitting part and removing the peak of the groove. A method of manufacturing a bracket for a rotating machine.