JP2559377Y2 - Measuring device for shear strength and deformation of foundry sand - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for automatically measuring the shear strength and deformation of foundry sand.

[0002]

2. Description of the Related Art Conventionally, a device as shown in FIG. 4 has been known as a device for measuring the shear strength and the deformation amount of foundry sand almost simultaneously. This apparatus comprises a sample cylinder 51 and a measurement ring 52 connected to a lower part thereof, and both are swingably supported by a gantry 53 while holding a sand sample S therein. A micrometer 54 is fixedly arranged on the side of the measurement ring 52, and when the handle 55 is turned, the screw 56 of the micrometer 54 advances so that the tip presses the side surface of the measurement ring 52. . An electrical pressure gauge 57 is provided at a position on the sample cylinder 51 opposite to the micrometer 54 so as to detect the pressure applied to the measurement ring 52.
In such an apparatus, when the screw 56 of the micrometer 54 pushes the side surface of the measurement ring 52, shear stress is generated near the connection surface between the sample cylinder 51 and the measurement ring 52 in the sand sample S, and the screw 56 The sand sample S eventually breaks when the advancing is continued. The pressure at this time is read by the pressure gauge 57, and the shear strain (deformation amount) is read by the dial of the micrometer 54. ("Jact News No.379" 63.7.20
Casting Technology Promotion Association p.18-20).

[0003]

[Problems to be Solved by the Invention] In the above measuring apparatus, when a load is applied to a sand sample, the handle of the micrometer must be rotated by a small amount by hand and at a constant speed. Is very annoying. Further, since the reading of the load and the amount of deformation is performed visually, an error occurs. The present invention has been made in view of such circumstances, and provides an apparatus that is easy to operate and can obtain accurate measured values in measuring the shear strength and deformation of a sand sample. It is intended to be.

[0004]

In order to achieve the above object, the present invention is intended to perform a work of applying a load to a sand sample with an electric servo cylinder and to display a measured value on an XY plotter. It is a gist. That is, the present invention
An air cylinder, which is disposed upward and has a disc-shaped pressure head fixed to the tip of a piston rod, an upper sample cylinder,
An intermediate sample cylinder and a lower sample cylinder are superimposed and connected concentrically to the upper part of the air cylinder,
A sample cylinder body in which the pressure head slides up and down so that the inside thereof can slide, and is disposed to be able to traverse over the sample cylinder body,
A test table having a bottom formed with a flat surface capable of closing the upper end opening of the sample cylinder, and a test table placed laterally on the side of the intermediate sample cylinder so that the tip of the piston rod can press the side of the sample cylinder. An electric servo cylinder, a load cell attached to the tip of the piston rod via a pressure head, and an encoder that detects the amount of rotation of a servomotor in the electric servo cylinder, wherein the intermediate sample cylinder is The load cell and the encoder are electrically connected to an XY plotter while being freely traversable via a roller conveyor.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on an embodiment. FIG. 1 is an overall configuration diagram of a molding sand shear strength and deformation amount measuring device according to the present invention, and FIG. 2 is an internal structure diagram of an electric servo cylinder. In the figure, an air cylinder 3 is fixed upward to a horizontal lower supporting member 2 provided at an intermediate level of a gate-shaped gantry 1, and a pressure head 5 is attached to a tip of a piston rod 4 of the cylinder 3. I have. On the upper part of the air cylinder 3, a lower sample cylinder 6a oriented in the vertical direction is coaxial with the cylinder 3 via the lower support member 2 and a middle support member 7 horizontally disposed above the lower support member 2. Connected to the lower sample cylinder 6
An intermediate sample cylinder 6b having the same inner diameter as this is provided concentrically and separably on a. The intermediate sample cylinder 6 b is sandwiched in the front-rear direction by the middle support member 7.
It is supported on a pair of hollow roller conveyors 8 and 8 installed above via a flange (not shown), and can be moved freely. On the intermediate sample cylinder 6b, an upper sample cylinder 6c having the same inner diameter as that of the intermediate sample cylinder 6b is arranged concentrically via a horizontal upper support member 9. That is, the lower sample cylinder 6a, the middle sample cylinder 6b, and the upper sample cylinder 6c are united concentrically to form one sample cylinder 6, and inside the sample cylinder 6, the pressure head 5 Are slid up and down. The lowering limit of the pressure head 5 is the upper end surface level of the lower sample cylinder 6a, and the upper limit is the upper end surface level of the upper sample cylinder 6c.

An electric servo cylinder 11 is disposed on the middle support member 7 so as to face the intermediate sample cylinder 6b and to follow the moving direction thereof. The cylinder 11
Is a cylindrical cylinder case 12 as shown in FIG.
A servomotor 13 attached to the right end opening side of the cylinder case 12 and capable of rotating forward and backward, a lid 14 for closing the left end opening of the cylinder case 12, and a loose fit inserted into the cylinder case 12; A cylindrical piston rod 15 slidable through the lid 14 and the cylinder case 12 fixed to the right end of the piston rod 15;
A first piston 16 slidable inside the first piston 1
6, a ball nut portion 1 formed through the center of the plane
7 and a ball screw portion 18 whose left end is screwed into the ball nut portion 17 and is loosely inserted into the piston rod 15.
And the right end side constitutes the drive shaft portion 19 of the servo motor 13, and can slide inside the piston rod 15 with one output shaft 23 which is vertically rotatable via bearings 21 and 22. And the left end of the ball screw portion 18 in the output shaft 23 is
It comprises a second piston 26 supported vertically rotatably via 4 and 25, and a disk-shaped pressure head 27 fixed to the left end of the piston rod 15. When the servo motor 13 rotates forward and backward, the output shaft 23 rotates forward and reverse, and accordingly, the piston rod 15 is extended and contracted via the first piston 16. A load cell 28 is attached to the front surface of the pressure head 27, and when the piston rod 15 is extended, the load cell 28 comes into contact with the side surface of the intermediate sample cylinder 6b and pushes it. .
A brake 29 for stopping the rotation of the output shaft 23 in an emergency is provided on the right end side of the drive shaft portion 19 in the output shaft 23, and the amount of rotation is detected at the rightmost end of the output shaft 23. Encoder 31 is mounted.

Above the sample cylinder 6, guide rods 33, 33, which form a pair in the front and rear direction, are horizontally disposed with both ends supported by the side walls of the gate-shaped gantry 1. Between the guide rods 33, 33, a test table 35 provided with guide cylinders 34, 34 on both sides is disposed by slidably fitting the guide cylinders 34, 34 to the guide rods 33, 33. Have been. Sprocket wheels 36, 36 are attached to both left and right ends of the ceiling of the portal gantry 1, respectively, and a first endless chain 37 is bridged between the sprocket wheels 36, 36. One of the sprocket wheels 36, 36 is rotatably driven by a motor 39 that can rotate forward and reverse through a second endless chain 38. The lower side of the first endless chain 37 is connected to the test table 35 via a bracket 41,
When the motor 39 is driven, the test table 35 is guided by the guide rods 33, 33 and reciprocates in the horizontal direction. A flat surface capable of closing the upper end opening of the sample cylinder 6 is provided at the bottom of the test table 35. A chute 42 is provided at the top of the portal gantry 1 at a position directly above the sample cylinder 6.

FIG. 3 is a block diagram of a control circuit in the electric servo cylinder 11. In FIG. 1, a central processing unit 4 composed of a plurality of microcomputers and the like is provided.
3, the encoder 31 and the load cell 28 are connected to the control signal input side, and the rotational speed converter 44 for controlling the frequency of the servo motor 13 is connected to the control signal output side. Based on the output torque converter 45 for controlling the output torque of the motor 13 and the amount of rotation of the encoder 31 and the detected pressure of the load cell 28, the shear strength and deformation of the molding sand are displayed.
The Y plotter 46 is connected. Further, the rotation speed converter 44 and the output torque converter 45 are connected to the servo motor 13 via a motor control unit 48.

[0009]

The operation of measuring the shear strength and deformation of the foundry sand with the apparatus constructed as described above will be described with reference to FIG. 1. When the piston rod 4 of the air cylinder 3 is contracted, With the pressure head 5 positioned at the lower limit level, first, casting sand is poured into the sample cylinder 6 via the chute 42 into the heap. Second, the motor 39 is driven to rotate forward to circulate and move the first endless chain 37, whereby the upper end opening of the sample cylinder 6 is closed at the bottom of the test table 35. At this time, excess sand at the upper end of the sample cylinder 6 is scraped off by the test table 35. In this state, when the piston rod 4 of the air cylinder 3 is extended thirdly,
The pressurizing head 5 is raised, and the molding sand in the sample cylinder 6 is subjected to a predetermined pressure (for example, between the pressurizing head 5 and the bottom of the test table 35).
At 10 kgf / cm ² ), a sand sample S is prepared.
The pressurizing head 5 stops rising when its pressure balances with the coercive force of the sand.
The height of the cylindrical body 6b is adjusted so that the upper surface of the cylindrical sample 6b always remains at the level in the intermediate sample cylinder 6b, that is, the lower part of the created sand sample S remains in the intermediate sample cylinder 6b. .

Thereafter, fourthly, the piston rod 4 of the air cylinder 3 is contracted to move the pressure head 5 to its original position (FIG. 1).
(The position shown in the figure). Fifth, when the servo motor 13 of the electric servo cylinder 11 is driven to rotate forward at a predetermined rotation speed and output torque, the pressure head 27 advances at a predetermined load speed (for example, 30 gf / cm ² / sec), and the load cell 28
Abuts against the side surface of the intermediate sample cylinder 6b. At this time, the XY plotter 46 is enabled by the signal from the load cell 28, and thereafter, the pressing force of the pressure head 27 and the rotation amount of the output shaft 23 are detected by the load cell 28 and the encoder 31, respectively. It is displayed on the XY plotter 46. That is, the temporal change of the detected pressure of the load cell 28 and the rotation amount of the encoder 31 until the sand sample S is finally broken by the advance of the pressurizing head 27 and the sand sample S is broken, Sand sample S
Is displayed on the XY plotter 46 as the shear strength and the amount of deformation. A command is issued from the output torque converter 45 at the moment when the sand sample S is broken, and the servo motor 13
, And the forward movement of the pressure head 27 is stopped. When the sand sample S in the sample cylinder 6 is removed after the measurement is completed, the following is performed. That is, the piston rod 15 of the electric servo cylinder 11 is retracted, the intermediate sample cylinder 6b is set at a concentric position with the lower sample cylinder 6a and the upper sample cylinder 6c, and the test table 35 is moved to the position shown in FIG. And the piston rod 4 of the air cylinder 3 is extended to operate the pressure head 5.
To the rising edge. Thereby, the sand sample S is extruded from the inside of the sample cylinder 6.

[0011]

According to the present invention as described above, since the shear strength and the deformation amount of the sand sample are read by the load cell and the encoder and displayed on the XY plotter, accurate measurement values can be obtained. Can be. In the present invention, the operation of applying a load to the sand sample is automatically performed by the electric servo cylinder, so that there is a merit that the operation becomes easy.

[Brief description of the drawings]

FIG. 1 is a vertical sectional front view of an essential part showing one embodiment of the present invention.

FIG. 2 is an internal structural view of an electric servo cylinder.

FIG. 3 is a block diagram of a control circuit in the electric servo cylinder.

FIG. 4 is a vertical sectional front view of a main part showing a conventional measuring device.

[Explanation of symbols]

 Reference Signs List 3 air cylinder 4,15 piston rod 5,27 pressure head 6 sample cylinder 6a lower sample cylinder 6b middle sample cylinder 6c upper sample cylinder 8,8 roller conveyor 11 electric servo cylinder 13 servo motor 28 load cell 31 Encoder 35 Test stand 46 XY plotter

Claims (1)

(57) [Scope of request for utility model registration] 1. An air cylinder 3 disposed upward and having a disc-shaped pressure head 5 fixed to the tip of a piston rod 4.
An upper sample cylinder 6c, an intermediate sample cylinder 6b, and a lower sample cylinder 6a are superposed, connected concentrically to the upper part of the air cylinder 3, and the pressure head 5 A sample cylinder 6 slidable up and down, and a test table arranged above the sample cylinder 6 so as to be able to traverse and formed at the bottom a flat surface capable of closing the upper end opening of the sample cylinder 6 35, an electric servo-type cylinder 11 which is placed laterally on the side of the intermediate sample cylinder 6b, and the tip of the piston rod 15 can press the side face of the sample cylinder 6b; A load cell 28 mounted via a pressure head 27;
And an encoder 31 for detecting the amount of rotation of the intermediate sample cylinder 3. The intermediate sample cylinder 6b can be traversed via roller conveyors 8 and 8, and the load cell 28
An encoder 31 is electrically connected to an XY plotter 46. A device for measuring the shear strength and deformation of molding sand.