SU1368678A1 - Method and apparatus for measuring pressure on side walls of mould channel - Google Patents

Abstract

Invention m. used to determine the parameters of the process of pressing bulk materials. The purpose of the invention is to improve the accuracy of measuring the pressure on the side walls of the matrix channel of the mold. Preliminarily, by a press force, a movable liner is advanced along the channel of the matrix 3, by measuring the value of the bottom pressure with a pressure gauge 1. The movable insert 1 is made of three rigidly interconnected disks 5-7. The extreme disks 5 and 7, installed in the channel of the matrix 3 with a gap, are made of rigid material, and the disk 6 is made of elastic material. The material then loaded into the channel is pushed by a press and the pressure at which is measured. compressed sample 4 is moving along the channel. The increase in the pressing force is due to the friction of the sample 4 against the walls of the matrix 3. The profile for determining the pressure on the side walls of the channel of the matrix is given at 3..2 sec. P. f-ly, 1 ill. i (L with O5 00 O5 00

Description

The invention relates to methods and devices for measuring physical quantities, in particular for determining the parameters of the process of pressing bulk materials and the magnitude of the pressure on the walls of the matrix channel during ram extrusion, the manufacture of molded articles from press materials.

The purpose of the invention is to improve the accuracy of measuring the pressure on the walls of the matrix channel.

The drawing shows a device for carrying out the proposed method.

The device consists of a pressure source 1 with pressure measuring devices, a punch 2, a heated matrix 3, a pressed sample 4, an insert consisting of an upper disc 5 with a threaded tip, an average deformable disc 6, a lower disc 7 and an adjusting nut 8, heaters 9 , stands 10. The bottom of the mold, formed by the disks, can move along the mold channel, and the pressure necessary for its advancement can be adjusted by changing the amount of deflection of the middle disk, it is not used in the process. movement.

The device works as follows.

Initially, under the action of the pressure of the press, the movable insert moves through the channel of the mold by a certain amount, and the pressure needed to advance it is measured. Then, a press material is loaded into the mold channel and again under the action of a press, it is pushed through the channel, and the pressure necessary to jointly advance the press material and the movable liner (bottom) is also measured.

The method of determining the pressure on the walls of the matrix channel is that, under the action of a pressing force, the movable insert pushes through the channel of the mold by a certain amount. The amount of pressure at which the movable contribution is carried out will be the value of the bottom pressure. This pressure is measured with high accuracy directly by a sensitive pressure gauge mounted on a press or any other

r

about

This is a high precision instrument.

To determine the pressure on the walls of the matrix channel, the press material is poured into the channel of the mold, then the compact is pushed and the pressure is measured at which the compact moves along the channel. Obviously, the pressure required to push the liner is greater than the pressure at which only the insert is pushed, and

5 „,„ 3 „,, - Pa uF. (one)

five

0

where P,

etc

T

& F

0

axes

 J axis) press pressure,

kgf / cm;

pressure to the bottom, kgf / cm increment of force due to the force of friction of the press material against the walls of the mold, the area of the cross section of the channel, see

Obviously, the increase in pressing force 5 by the value of uF occurs only due to the additional force of friction of the press material against the walls of the channel of the mold. To determine this force, the ratio iF РВОК SBOH 5 (2) is the average pressure on the side walls of the channel, kg / cm i

the area of interaction of the press material with the channel walls, cm J coefficient of friction of the press material.

Substituting (2) in (1), get the ratio

Aim of the PJOK Sjo from which determine the value of pressure on the walls of the channel

where r

SIDE.

Sok

H

P EiP-I-St. §Au

(3)

R

 SIDE

The coefficient of friction involved in the calculation formulas is determined experimentally depending on

50 types of material.

Thus, the method and apparatus for determining the pressure on the walls of the matrix channel when pressing molded products from various press55 materials in comparison with the known ones has the ability to determine the pressure on the walls of the channel during the movement of compressed material in it, which is especially necessary

It is necessary in the calculation and design of equipment for the manufacture of molded products from press compositions. In addition, the proposed method and device make it possible to determine with high precision the technological parameters of the process of pressing products using a plunger extrusion method.

Claims (2)

1. A method for measuring pressure on the side walls of a die matrix channel, including pressing pressure measurement with a pressure gauge, distinguished by the fact that, in order to improve measurement accuracy, a movable liner is placed in the die channel, the pressure is pressed and the liner is advanced through the die channel , the value of the bottom pressure P is determined, then the press material is loaded into the die channel, it is pushed along the channel and the outer diameter of the middle disk is measured by pressure compaction P, and the pressure is equal to the diameter of the die channel, and the side walls of the matrix channel P, the outermost disks are mounted on the channel determined from the ratio with the gap.  SIDE  .. fr R R  OSI  60K where „is the coefficient of friction against the channel walls; channel section area; - area of contact of the surface of the pressed material with the channel. 2. A device for measuring the pressure on the side walls of the die matrix channel, including a pressure source with a pressure gauge, a punch 5 and a matrix with a channel, which is so that, in order to improve the measurement accuracy, it is equipped with a movable liner installed in the matrix channel, which is made 0 through, while the insert consists of three rigidly interconnected disks, the outermost of which are made of rigid material and the middle one is made of elastic material, with