JP3218593B2 - Raw material amount confirmation device for powder molding press - 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 confirming a raw material amount of a powder molding press used for powder metallurgy.

[0002]

In a powder molding press used for powder metallurgy, raw material powder contained in a hopper is supplied to a powder molding die via a feeder. As the molding is repeated, the amount of the raw material powder in the hopper decreases, but this hopper must be replaced before the raw material powder in the hopper runs out so as not to interrupt the molding operation.

In order to know when to replace the hopper, it is necessary to know the remaining amount of the raw material powder in the hopper.
I had to check the remaining amount. For this reason, the efficiency of the checking operation is low, and there is a possibility that the molding may be interrupted without performing the checking operation at an appropriate time. Some hoppers have a vertical transparent window on the side to make it easier to check the remaining amount.However, since the remaining amount cannot be checked without going close to the hopper, the above problem can be solved. is not.

An object of the present invention is to solve such a problem, and an object of the present invention is to provide a raw material amount checking device capable of efficiently and surely checking a raw material amount in a hopper.

[0005]

According to a first aspect of the present invention, there is provided an apparatus for confirming an amount of a raw material in a hopper containing raw material powder supplied to a molding die by a powder molding press. An electric distortion sensor provided on a hopper receiving base that detachably supports the hopper and detecting distortion of the hopper receiving base, and a display corresponding to the magnitude of the distortion detected by the distortion sensor. And a display for performing the operation.
A receiving member made of an elastic material on which the flange at the upper end rests
The receiving member includes a base portion and the base member.
Hopper receiving part located above the
Plate-shaped connecting part that connects the part and the hopper receiving part integrally
When the strain sensor is provided in this connection portion,
In addition, the hopper is placed on the hopper receiving
On which the flange portion is mounted .

When the amount of raw material in the hopper changes,
The load applied from the hopper to the hopper receiver changes, and the distortion of the hopper receiver caused by the load also changes. This distortion is detected by an electric distortion sensor, and the display gives a display corresponding to the magnitude of the detected distortion, that is, the amount of raw material in the hopper. The operator can know the amount of the raw material in the hopper by the display on the display. Also,
The force applied from the hopper to the receiving member is more
Side to the hopper receiving part, the plate-shaped connecting part
Generates a bending moment, which causes a large strain.
I will. The distortion of this connection is detected by a strain sensor
As a result, the sensitivity and accuracy of detection are increased.

According to a second aspect of the present invention, there is provided the powder of the first aspect.
In the apparatus for checking the raw material amount of a molding press, the hopper receiving
On the top of the hopper, and on the bottom of the flange of the hopper.
The whole is provided with a convex portion which hits at one time.

When the hopper is mounted on the hopper receiving base, even if the hopper is displaced in the horizontal direction, the entire upper surface of the convex portion of the hopper receiving portion comes into contact with the lower surface of the flange portion of the hopper. The point of action of the force from the hopper to the receiving member is always constant, and the relationship between the amount of the raw material in the hopper and the distortion generated at the connecting portion is also constant.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a raw material amount checking apparatus for a powder molding press according to the present invention will be described below with reference to FIGS. 1 and 2, reference numeral 1 denotes a hopper, and reference numeral 2 denotes a hopper support provided in a powder molding press. The hopper 1 has an open upper surface,
An outlet 3 is provided at the lowermost portion, and the outlet 3 is connected to a feeder (not shown) by a hose 4.
The raw material powder stored in the hopper 1 is supplied to a powder molding die (not shown) through a hose 4 and a feeder. In addition, the hopper 1
A concentric flange 5 is provided at the upper end edge.

The hopper receiving base 2 removably supports the hopper 1, and a receiving member 8 is annularly provided at an upper end of a supporting frame 7 fixed vertically on a base 6. The flange portion 5 of the hopper 1 rests on the receiving member 8. The receiving member 8 is made of a material having appropriate elasticity such as steel. The receiving member 8 has a substantially H-shaped cross section, and has a horizontal plate-like base 9 fixed on the support frame 7 and a horizontal plate-like hopper located above the base 9. It comprises a receiving portion 10 and a vertical plate-like connecting portion 11 for integrally connecting the central portions of the base portion 9 and the hopper receiving portion 10. On the upper surface of the hopper receiving portion 10, an annular contact plate 12 forming a convex portion is provided.
And are concentrically fixed. The backing plate 12 is connected to the connecting portion 11
And the hopper 1
The flange portion 5 is placed on the hopper receiving portion 10 on the inner peripheral side of the connecting portion 11. The dimension (outer diameter or diagonal length) L1 of the outer peripheral surface of the backing plate 12 is equal to the dimension (outer diameter or diagonal length) L2 of the outer peripheral surface of the flange portion 5.
Is smaller than. Furthermore, the difference between the width L2 of the outer peripheral surface of the flange 5 and the width L1 of the outer peripheral surface of the backing plate 12 is determined by the width of the inner peripheral surface of the hopper receiving portion 10 including the backing plate 12 (inner diameter or diagonal line). It is preferable that the difference be larger than the difference between the length L3 and the dimension (outer diameter or diagonal length) L4 of the outer peripheral surface of the hopper 1 immediately below the flange portion 5. Thus, in a state where the hopper 1 is mounted on the hopper receiving base 2, the entire upper surface of the abutment plate 12 hits the lower surface of the flange portion 5 irrespective of the horizontal position of the hopper 1 with respect to the hopper receiving base 2.

The plane shape (projection shape on the horizontal plane) of the hopper 1, its flange portion 5, and the receiving member 8 may be a circle, a square, or another shape. However, the flange portion 5 and the receiving member 8 should be in contact with each other over almost the entire circumference. An electrical distortion sensor 21 for detecting the distortion of the connecting portion 11 is mounted on the outer peripheral surface of the connecting portion 11 of the receiving member 8 by means such as bolting. This strain sensor 21 utilizes, for example, the fact that the resistance value changes due to deformation,
Outputs a voltage corresponding to the distortion. Also has excellent durability.
Note that the strain sensor 21 may be provided at only one location of the connecting portion 11, or may be provided at a plurality of locations. Strain sensor 21
Increasing the number increases the detection accuracy but increases the cost.

As shown in FIG. 3, the distortion sensor 21 is connected to an LED display 23 via an amplifier 22. The LED display 23 performs a display corresponding to the magnitude of the distortion detected by the distortion sensor 21, and thereby displays the amount of the raw material in the hopper 1. The LED display 23 performs analog bar display as shown in FIG. 4 (for example, RBV manufactured by Balcom Inc.). That is, the display unit 24 displays a large number of L
ED25 is arranged side by side, and a certain number of LEDs from the bottom
25 lights up to form a bar. For example, as the detected distortion is larger, that is, as the amount of the raw material in the hopper 1 is larger, more LEDs 25 are turned on to form a longer bar. The display unit 24 changes the emission color of the LED 25 at the lower part 24a, the middle part 24b, and the upper part 24c. And this LED display 23 is installed in a place which is easy for an operator to see, different from the hopper 1.

As shown in FIG. 3, the LED display 23 has a comparison circuit 27 connected to an input circuit 26 to which the amplifier 22 is connected. The comparison circuit 27 is connected to the LED 25 via an LED drive circuit 28. Is connected. The comparison circuit 27
Has a zero adjuster 29 and a scale adjuster 30. The comparison circuit 27 compares the output voltage from the strain sensor 21 with a plurality of reference voltages, for example, and performs an output corresponding to the output voltage from the strain sensor 21. The LED drive circuit 28 lights the number of LEDs 25 corresponding to the output voltage from the distortion sensor 21 based on the output from the comparison circuit 27. Zero adjuster 29
Is operated by a user, and changes a plurality of reference voltages of the comparison circuit 27 by subtraction or addition. The scale adjuster 30 is operated by the user and includes a comparison circuit.
27 multiple reference voltages are changed by multiplication. That is,
The LED display 23 can perform zero point adjustment and scale adjustment, and can perform appropriate display according to the type of raw material powder and the like.

Next, the operation of the above configuration will be described. At the time of molding, the raw material powder in the hopper 1 mounted on the hopper receiving table 2 is sequentially supplied to a powder molding die via a feeder. As the amount of raw material in the hopper 1 decreases in this way, the load applied from the hopper 1 to the receiving member 8 of the hopper receiving base 2 also decreases, and the distortion of the receiving member 8 caused by this load also changes. That is, when the amount of the raw material in the hopper 1 is large, the receiving member 8 bends so that the connecting portion 11 is inclined upward and inwardly as shown by a chain line in FIG. When the amount is reduced, as shown by a solid line in FIG.
11 is less bent.

The distortion of the connecting portion 11 is detected by a distortion sensor 21, and the magnitude of the detected distortion is indicated by an LED.
It is displayed on the display 23. In this display, the smaller the detected distortion, that is, the smaller the amount of raw material in the hopper 1, the shorter the length of the bar formed on the display unit 24 by the LED 25. Therefore, the operator can efficiently and surely check the amount of the raw material in the hopper 1 only by looking at the display of the LED display 23 without going to the hopper 1. Then, when the amount of the raw material in the hopper 1 is reduced to a predetermined amount, the hopper 1 containing the raw material powder is brought to the hopper receiving table 2 and the hopper 1 may be replaced. Since the amount of the raw material in the hopper 1 can be reliably confirmed, it is possible to prevent a situation in which the molding is interrupted without performing the confirmation operation at an appropriate time. And LE
The analog bar display by D25 is easy to understand and easy to understand, and the operator is less likely to overlook the display when necessary. Further, the color of the display portion 24 formed by the LEDs 25 changes between the upper portion 24c, the middle portion 24b, and the lower portion 24a, so that the outline of the raw material amount in the hopper 1 can be immediately determined from the appearance of the colors.

The force applied from the hopper 1 to the receiving member 8 is greater on the inner peripheral side than the connecting portion 11.
Therefore, a bending moment is generated in the plate-shaped connecting portion 11 as shown by an arrow in FIG. Since the strain sensor 21 detects the distortion of the connecting portion 11, the change in the output voltage of the distortion sensor 21 can be increased, and the sensitivity and accuracy of detection are improved. Therefore, the amount of the raw material in the hopper 1 can be confirmed more accurately and reliably. Further, a hopper receiving portion 10 on which the flange portion 5 of the hopper 1 rests.
Since the contact plate 12 having a smaller outer diameter than the flange portion 5 is provided on the upper portion, even when the hopper 1 is mounted on the hopper receiving base 2 even if the hopper 1 is displaced in the horizontal direction. Since the entire upper surface of the backing plate 12 contacts the lower surface of the flange portion 5, the point of application of the force from the hopper 1 to the receiving member 8 is always constant. Therefore, the relationship between the amount of the raw material in the hopper 1 and the distortion generated in the connecting portion 11 of the receiving member 8 is always constant, so that the amount of the raw material in the hopper 1 can be stably confirmed.

If the hopper 1 is provided with a sensor for confirming the amount of raw material, the number of the hoppers 1 is larger than that of the hopper receiver 2, so that the cost is higher. Since the sensor 21 for checking the amount of the raw material in the hopper 2 is provided on the hopper receiving base 2, the cost can be reduced. Further, by adjusting the zero point and the scale of the LED display 23 with the zero point adjuster 29 and the scale adjuster 30, an appropriate display can be performed according to the type of the raw material powder and the like. For example, the specific gravity of the raw material powder differs depending on the type of iron, copper, etc., but if the zero point and the scale are appropriately adjusted, the bar display of the display unit 24 will have the maximum length when the hopper 1 is full of the raw material powder. , And the bar display on the display unit 24 can be set to just disappear when the inside of the hopper 1 becomes empty. Thereby, the amount of the raw material in the hopper 1 can be accurately known for each raw material powder. Of course, even at the first installation of the present raw material amount checking device, it is necessary to adjust the zero point and the scale according to the conditions of the hopper 1 and the like.

FIG. 5 shows another embodiment of the raw material amount checking apparatus according to the present invention. In this embodiment, the magnitude of the strain detected by the strain sensor 21 is determined by the amount of the raw material in the hopper 1. An alarm device 31 is provided as a display device for giving an alarm by light and sound when a value corresponding to a value below the fixed amount is obtained. In the alarm device 31, a comparison circuit 27 is connected to an input circuit 26 for inputting an output from the distortion sensor 21, and an alarm lamp 33 is connected to the comparison circuit 27 via a lamp driving circuit 32. , Buzzer drive circuit 34
The buzzer 35 is connected via the. The comparison circuit 27, for example, compares the output voltage from the strain sensor 21 with a reference voltage, and outputs a high-level signal if the output voltage is lower than the reference voltage. When a high level signal is output from the comparison circuit 27, the lamp drive circuit 32 turns on the alarm lamp 33,
The buzzer drive circuit 34 makes the buzzer 35 sound. Zero adjuster
Reference numeral 29 is operated by the user, and changes the reference voltage of the comparison circuit 27.

As described above, when the amount of the raw material in the hopper 1 becomes equal to or less than the predetermined amount, that is, when it is time to replace the hopper 1, the alarm device 31 gives an alarm by light or sound. A person can surely know that it is time to replace the hopper 1, and the risk of losing that time is greatly reduced. In this embodiment, only one of the alarm lamp 33 and the buzzer 35 may be provided. Further, the LED display 23 and the alarm 31 of the embodiment described above can be used together. In this case, LED
The output of the comparison circuit 27 of the display 23 causes the lamp driving circuit 3
2. The buzzer drive circuit 34 may be operated. Further, the display device for displaying the amount of raw material in the hopper 1 is not limited to a bar display using the LED 25, but may be a digital display using numbers or a dial meter display. it can.

The structure of the receiving member 8 is not limited to that of the above-described embodiment, and various structures can be used. For example, as shown in FIG. 6, two pipes 8a and 8b each having a U-shaped cross section may be combined, or as shown in FIG.
It may be constituted by one pipe having a U-shaped cross section.

[0021]

According to the first aspect of the present invention, a distortion sensor is provided on the hopper receiving base by utilizing the fact that the hopper receiving base is distorted by the load from the hopper, and a display corresponding to the magnitude of the detected distortion is provided. It is performed by the display unit, and can check the material quantity in the hopper efficiently and reliably, also connecting portion
Is greatly distorted by the bending moment.
The sensitivity and accuracy of the
Ru can be a confirmation of the raw material amount more accurately reliably.

According to the second aspect of the present invention, in addition to the effect of the first aspect of the present invention, a convex portion is provided on the upper surface of the hopper receiving portion so that the entire upper surface contacts the lower surface of the flange portion of the hopper at once. Even if the horizontal position of the hopper with respect to the cradle is not constant, the point of action of the force from the hopper to the receiving member is always constant, so that the amount of the raw material in the hopper can be confirmed stably. .

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing an embodiment of a raw material amount checking device for a powder molding press according to the present invention.

2A and 2B are side views of the whole of the same, wherein FIG. 2A is a cross-sectional view of a hopper receiving stand, and FIG. 2B is an external view of the hopper receiving stand.

FIG. 3 is a block diagram showing an electric circuit according to the first embodiment;

FIG. 4 is a front view of the display device.

FIG. 5 is a block diagram showing another example of the electric circuit of the raw material amount checking device for a powder molding press according to the present invention.

FIG. 6 is a cross-sectional view showing another example of the receiving member of the raw material amount checking device for the powder molding press of the present invention.

FIG. 7 is a cross-sectional view showing still another example of the receiving member of the raw material amount checking device for the powder molding press of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Hopper 2 Hopper receiving stand 5 Flange part 8 Receiving member 9 Base part 10 Hopper receiving part 11 Connecting part 12 Backing plate (convex part) 21 Strain sensor 23 LED display

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-255626 (JP, A) JP-A-7-77457 (JP, A) JP-A-7-330304 (JP, A) JP-A-49-49 127364 (JP, A) Japanese Utility Model Showa 57-129127 (JP, U) JP-B-59-17767 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01G 21/23

Claims (2)

(57) [Claims] 1. An apparatus for confirming the amount of raw material in a hopper containing raw material powder supplied to a molding die by a powder molding press, said apparatus being provided on a hopper receiving base for detachably supporting said hopper. An electric distortion sensor for detecting the distortion of the hopper cradle, and an indicator for performing a display corresponding to the magnitude of the distortion detected by the distortion sensor , wherein the hopper cradle has an upper end portion of the hopper.
A receiving member made of an elastic material on which the flange
The receiving member comprises a base portion, and
Hopper receiving part, and these base part and
It has a plate-shaped connecting part that connects the hopper receiving part integrally.
And, while providing the strain sensor in this connection portion,
On the hopper receiving part on the inner peripheral side than the connection part,
An apparatus for confirming the amount of raw materials of a powder molding press, having a flange mounted thereon. 2. The apparatus according to claim 2 , wherein the
A convex part where the whole upper surface hits the lower surface of the par flange at once.
2. A powder molding preform according to claim 1, wherein:
Device for confirming the amount of raw materials.