JPS5837954Y2 - Kagaku Kenmasouchi - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a chemical polishing device used for finishing the surface of molds and other workpieces.

For example, electrical discharge machining is widely used today and is particularly effective for forming molds and the like.

However, in electrical discharge machining, the machining speed and machined surface roughness are inversely proportional, and in particular, machining speeds of only several mg/min can be obtained to keep the machined surface roughness below several μRmax.
Furthermore, even if the machined surface is finished around lμRmax, if a mirror surface is required or if it is necessary to remove the heat change layer from electrical discharge machining, it is necessary to perform post-finishing processing using various polishing methods, including manual polishing. Therefore, it is customary today to perform electrical discharge machining to obtain a machined surface roughness of, for example, 15 to 30 .mu.Rmax, which is not so slow, and then perform finishing machining by means other than post-discharge machining.

However, electrical discharge machined surfaces not only have a heat change layer that is difficult to remove with normal mechanical grinding means and have poor polishing efficiency, but also have many shapes that are difficult to mechanically finish. For this reason, much of the work has traditionally been done by hand, but finishing methods such as chemical polishing, electrolytic polishing, and electrolytic machining are now being used.

Chemical polishing can be done by using a liquid that matches the material of the workpiece.
It is known that smooth mirror surfaces of Rmax or less can be achieved at speeds on the order of around g/min per unit area.

It is also known that chemical polishing fluids have a limited lifespan, that is, as the amount of workpiece metal dissolved in the fluid or its proportion increases, the machining speed decreases, and therefore, the fluid needs to be replaced when this percentage is reached. ing.

This also means that the amount of chemical polishing applied to the workpiece is normally controlled or adjusted by the chemical polishing time, so while it is necessary to adjust the machining time between a new liquid and a liquid that has already been used for processing, it is necessary to adjust the processing time when using an old liquid. It is not a good idea to use it for any length of time from the viewpoint of processing efficiency.

For this reason, in the past, records were kept of how many hours were processed, how much area was processed, etc., and when the total usage time or the product of the usage time and the processing area reached a certain value, I am trying to update the chemical polishing fluid.

Although there are, for example, brass molds and molds made of special alloy materials, most of these molds are made of iron, the main component of which is iron.

Of course, the present invention is not limited to chemical polishing of iron materials, but the present invention will be described below with respect to mold polishing of iron materials.

For example, using 100 g/l of hydrogen peroxide and 50 g/l of acidic ammonium fluoride as chemical polishing liquid, the workpiece is made of 355C iron material processed by electric discharge machining to a machined surface roughness of approximately 15 μRmax, and the surface is finished by chemical polishing. The relationship between the amount of Fe dissolved in the chemical polishing solution, the processing speed of chemical polishing, and the finished surface roughness during processing is as shown in FIG.

In other words, the machining speed slows down as the chemical polishing fluid is new and the amount of dissolved Fe increases, but the roughness of the machined surface becomes rougher when the fluid is too new or too old. Time is the best.

However, chemical polishing is better if the processing speed is faster, but since the purpose is surface finishing, if the processed surface roughness reaches a certain value, that is, if the amount of dissolved Fe reaches a certain value, then Replace with new fluid or refill with new fluid.
In order to achieve this goal, it is necessary to reduce the proportion of dissolved amount of

Therefore, the present invention takes these points into consideration and proposes an apparatus suitable for chemical polishing of molds, etc.

The drawing is an explanatory diagram of an embodiment for explaining the present invention, and 1 shows a workpiece, 2 a nozzle for spraying chemical polishing liquid onto the workpiece 1,
3 is a nozzle holder; 4 and 5 are feed screws in the X- and Y-axis directions of the holder 3 that engage with the holder 3 in a perpendicular direction; and 6 and 7 are feed screws 4 and 5 to control the nozzle position. A control device such as a copying sequence controller or NC control, 8 is a storage tank for chemical polishing liquid, 9 is a pump that supplies the chemical polishing liquid to nozzle 2, and 10 is Fe in the supply liquid provided in the liquid supply pipe. A detection device such as a solubility atomic absorption spectrometer, electrolytic electrometer, polarograph, or transmitted light detection type photometer for detecting the dissolved amount of 12 is a stirring device for stirring the chemical polishing liquid in the storage tank 8, 13 is a storage tank for new chemical polishing liquid, 14 is a supply control valve, and 15 is a drain control valve.

That is, the output of the detection device 10 is not only used to simply display the information, but also to automatically control the stoppage of the pump 9 and the opening and closing of the valves 14 and 15 as necessary.

The chemical polishing liquid in the storage tank 8 is circulated and used.
When it is detected that 0 has reached 20% of the amount of dissolved Fe in FIG.

Next, drain valve 15 is opened to drain some or all of the liquid, and then valve 14 is opened to replenish new chemical polishing liquid.

The liquid discharged from the valve 15 is recycled or disposed of.

When finishing polishing the workpiece 1 in this manner, the detection device 10 detects that the amount of dissolved Fe has exceeded the allowable limit of 1.2 speeds after several pieces have been processed, and it is necessary to replace or replenish the liquid. The chemical polishing liquid used during processing is kept within a predetermined range of processing speed and finished surface roughness, so there is no need to keep records of chemical polishing time, processing area, machining allowance, etc. This eliminates machining errors.
Chemical polishing can be performed efficiently.

The present invention can be applied to cases other than chemical polishing of iron materials, and various modifications can be made to the implementation apparatus, such as installing a detection device for the chemical polishing liquid in a storage tank.

[Brief explanation of the drawing]

FIG. 1 is a processing characteristic diagram of a chemical polishing liquid, and FIG. 2 is a schematic configuration diagram of an example apparatus. 2 is a nozzle, 8 is a storage tank, 9 is a pump, 10 is a detection device,
11 is a display device.

Claims (1)

[Scope of utility model registration request] a chemical polishing liquid storage tank; a pump for pumping up and supplying the chemical polishing liquid; a nozzle for supplying the chemical polishing liquid from the pump to the processing area of the workpiece through a pipe line; and a nozzle for supplying the chemical polishing liquid to the storage tank. In an apparatus equipped with a recovery device via a pipe, a device for detecting the dissolved amount of workpiece metal contained in the chemical polishing liquid is provided in the supply pipe or storage tank for the chemical polishing liquid, and the detected value is also detected. A chemical polishing device equipped with a display device for displaying information.