JPS58210542A - Method and device for testing abrasion - Google Patents

Abstract

PURPOSE:To reproduce the influential factor for the abrasion of a die and to test the abrasion thereof with high accuracy by bringing a blank model and a die model into contact with each other, to generate sliding friction between both, then changing the engaging positions of both models with a moving mechanism to repeat the test. CONSTITUTION:A blank model 1 is mounted to a revolving shaft 2 and is rotated by a motor 8. A die model 20 of the same material as a forging die is mounted to a flat plate 13 supported to a column 14, and is provided movably horizontally by means of a handle 17 and movably vertically by means of a motor 18 and a screw shaft 19. The model 1 is heated to the temp. in the stage of forging with a coil 24 for heating, and the model 20 is brought into contact with the model 1 by mans of the handle 17, then the model 1 is rotated and is subjected to an abrasion test. The model 20 retreats upward, and a lubricant is coated thereon, whereafter the model 20 is moved vertically again and the test is repeated in the changed position. The influential factors for the abrasion of the die, such as temp., peripheral speed, pressure or the like are thus reproduced and the abrasion of the die is tested with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for testing wear on items such as forging dies and sheet metal dies, which are subject to repeated sliding friction.

The accuracy of a plastically worked product is determined by the accuracy of the mold, so if the mold wears out and the predetermined accuracy cannot be maintained, it is necessary to replace the mold.

Mold wear is a factor that impedes the economic efficiency that is a feature of plastic working, and in particular, as the main process becomes more highly precise, the mold wear problem is becoming more and more prominent.

At the production site, to prevent mold wear as much as possible.

Mold materials and processing conditions. Although efforts are being made to optimize lubricants,
A culm whose mold wear can be handled only by desk study.

Since the wear theory has not been developed yet, a long period of trial and error is required during actual production, resulting in large cost losses.

In order to improve this current situation, the use of wear testing methods has been considered. Conventionally, the test piece is heated to the plastic working temperature and a high surface pressure similar to that of plastic working is applied, which is a method that is relatively close to the actual condition. A reproducible test method has been devised.

In general, mold wear in plastic working occurs when the mold and material come into contact for only a fraction of a second to a few seconds during processing, causing relative slippage, and then the molded material is removed and lubricant is applied.
This occurs during the cycle of attaching. Therefore, the temperature at the contact area between the mold and the material, which has the greatest effect on mold wear, varies over a certain cycle.

If the specimens are simply rubbed together while they are in contact with each other as in the conventional method, the temperature cycle cannot be reproduced, resulting in insufficient accuracy. Conventional methods not only have these temperature problems.

Because the specimen remains in contact with the test piece, the test is conducted in a state where wear particles are trapped, and due to wear particles.

There is a lot of scratching and wear (this also causes a decrease in accuracy).

The present invention eliminates these drawbacks by V[1].A material model having a cylindrical surface is opposed to a flat plate to which a mold model is attached, and the mold models attached to the plates are placed on the cylindrical surface of the material model. The iF material and the material model are moved relative to each other in the direction of the generatrix of the cylindrical surface, and the mold model and the material model are Since sliding friction is generated again after changing the engagement position, sliding friction is applied intermittently to the test piece, making it possible to reproduce the thermal cycle of the worn part. .

Scratch wear caused by wear particles from test pieces, etc. does not occur, and
The object of the present invention is to provide a wear testing method that does not cause a decrease in accuracy due to this.

In addition, the present invention embodies the test method having the effect described in -F, and includes a material model having two cylindrical surfaces and a mold model disposed opposite to the material model. A feeding mechanism that slides the flat plate in a direction perpendicular to the cylindrical generatrix of the material model, a lateral movement mechanism that changes the distance between the material model and the flat plate, and a lateral movement mechanism that changes the position of the material model and the flat plate in the cylindrical generatrix direction. The present invention provides an abrasion testing device characterized by comprising a vertical movement mechanism that allows

The present invention will be described below with reference to an embodiment of the apparatus shown in FIGS. 1 and 2. In this embodiment, a case is shown in which the wear of a mold used for forging is simulated, but it can also be applied to a sheet metal mold or other molds in which sliding friction occurs periodically.

l is a material model having a cylindrical surface made of a forged material, and is attached to a hollow rotating shaft 2, and a bed 81
It is supported horizontally by fixed housings 4 and 5. The above material model l is attached to the end of the rotating shaft 2 (
The J-digit pulley 6 and the pulley 7 that engages with it via a belt are rotated by the motor 8 to rotate at a predetermined circumferential speed.

Reference numerals 9 and 10 denote rotary joints that can be respectively installed at both ends of the above-mentioned hollow rotating shaft 2, and are connected to water pipes 1.1 and 12 that communicate with a cold water source (not shown) and circulate cooling water. .

Reference numeral 18 denotes a flat plate supported by the column 14, which slides on the column 14 when driven by the printer 15, and is disposed so that its sliding direction is orthogonal to the cylindrical generatrix of the material model 1.

The column 14 is disposed on a table 161 and can be moved laterally using a handle 17 so that the distance between the material model 1 and the flat plate 18 can be changed.

In addition, the table 16 is the housing 2 attached to the bed 8.
9 and a motor 18, the table 16 is threadedly engaged with a screw shaft 19 which is arranged horizontally and parallel to the rotation axis 2 and rotates. Moving.

A cylindrical mold model 20 made of the same material as the forging mold is placed on the surface of the flat plate 13, and lubricant discharged from a nozzle 21 is sprayed thereon.

Reference numeral 24 denotes a high-frequency heating coil, which heats the material model 1 to a predetermined temperature.

The temperature of material model I is measured using a radiation thermometer or the like.

The test procedure using this test device is as follows.

First, the temperature of the material model I is heated with a high-frequency heating coil 24 so as to match the temperature of the actual material passing through the die wear part during forging, and measured by radiation wetness analysis.

Next, operate the handle 17 to move the column 14 laterally,
As shown in FIG. 2 (al), the outer periphery of the material model 1 and the mold model 20 are caused to interfere with each other by a certain amount, and the material model 1 is rotated around the rotation axis 2, thereby causing the material model 1 and the mold model 20 ( At this time, the mold model is stopped.) As shown in the figure jbl, when the rubbing between the material model 1 and the mold model 20 is finished, the mold model 20 is
It is moved upward by the air cylinder 15 and retracted, and lubricant is applied from the old nozzle. Thereafter, the motor 18 is driven to rotate the screw shaft 19, and the column 14. That is, the mold model 20 attached to the flat plate 13 is moved vertically, and the wear test is performed by repeating the above-described cycle.

Therefore, according to the apparatus of this embodiment, each influencing factor of mold wear can be reproduced as shown below, so it is possible to manually input these factors in actual plastic working into the testing machine, and it is possible to perform high-precision testing. can be realized.

l) The temperature of the material is adjusted by heating the surface of the material model 1 with a high-frequency heating coil 24.

2) Adjust the sliding speed by adjusting the circumferential speed of the material model l and the rotation speed of the motor 8 for driving the material model.

Set to a given value.

8) Since the amount of slippage is given as the arc length of the material, the arc length of the material is processed and set so that the predetermined amount of slippage is achieved.

4) The contact pressure is set to a predetermined pressure by adjusting the amount of interference between the mold model 20 and the material model 1 by lateral movement of the column 14.

5) Adjust the cycle time as shown in Figure 2 (bl) to match the cycle time.

Furthermore, material model 1 is heated to high temperatures (up to 1800℃).
As a result, heat flows into the housings 4 and 6 through the rotating shaft 2, and there is a risk that the bearings therein will heat up and seize. Since the cooling water is circulated through 12, the heat does not reach the bearings or the like.

As a result, the temperature cycle of the contact area between the mold and the material described above can be made the same as in actual plastic working, and the wear test can be performed under these conditions with the same relative sliding speed and sliding amount as in reality. In addition, new lubricant can be applied each time the molds rub against each other, and there is no obstacle such as abrasion powder remaining between the mold and the material as in the conventional method described above.

From the following, it is possible to perform a wear test with higher accuracy than the conventional method.

FIG. 3 shows another embodiment of the present invention.

The difference between this device and the one in FIG. 1 is that the material model 1 and the coil 24 are covered by a cylindrical expandable cover 26, and an inert gas (for example, nitrogen gas) is introduced into the cover 26. That is what we are doing.

Note that the cover 26 and the rotating shaft 2 are loosely fitted, and a portion of the cover 26 is cut out so that the mold model 2o and the material model 1 can be engaged with each other.

The position of the cutout can follow the vertical movement of the mold model 20 as the table 16 moves.

In this embodiment, in addition to the effects of the apparatus shown in FIG. This makes it possible to prevent accuracy deterioration due to oxides.

[Brief explanation of the drawing]

Fig. 1 is an overall perspective view of an apparatus showing one embodiment of the present invention, Fig. 2 is a diagram showing the relationship between a material model and a mold model, and Fig. 8 is a diagram showing a part of the apparatus showing another embodiment of the invention. It is a diagram. l...Material model, 2...Rotation axis, 9/1o...
Rotating joint, IT・12...Water pipe, 18...
Flat plate, 14... Column, 15... Cylinder, 16.
...Table, +7...Handle, 18...Motor, 19...Screw shaft, 20...Model. 24...Coil, 26...Cover. 1st Seki (i (b) Sai 2 Kaga 3 figures

Claims (2)

[Claims] (1) When a flat plate with a mold model attached is placed opposite to a material model having a cylindrical surface, and the mold model attached to the flat plate is brought into contact with the cylindrical surface of the material model, both surfaces are perpendicular to the generatrix of the cylinder. Then, the flat material and the material model are moved relative to each other in the direction of the generatrix of their cylindrical surfaces, and the engagement position between the die model and material model is changed, and then the sliding friction is generated. A wear test method that produces sliding friction. (2) a material model having a cylindrical surface, a flat plate to which a mold model is attached facing the material model, and a feeding mechanism that slides the flat plate in a direction orthogonal to the cylindrical generatrix of the material model; 1. A wear testing device comprising: a horizontal movement mechanism that changes the distance between the material model and the flat plate; and a vertical movement mechanism that changes the position of the wood model and the flat plate in the cylindrical generatrix direction.