JP5046065B2 - Combination weighing device - Google Patents

Description

  According to the present invention, in a “combination weighing device” that combines objects having different weights so as to have a predetermined weight, mechanical vibration is generated due to a collision between a weighing object and a hopper part or opening / closing of a gate part. The present invention relates to a low-noise and high-accuracy “combination weighing device” in which steel having excellent vibration damping properties is arranged in a generated portion, noise due to mechanical vibration is suppressed, and weighing accuracy is improved.

Conventionally, in the “combination weighing device”, the supplied objects having different weights are distributed and introduced into a plurality of storage hoppers, and subsequently, the weighing objects put into each of the storage hoppers are transferred to the corresponding weighing hoppers. The combination that is closest to the measurement set value and does not fall below the set value is selected based on the measurement value at each weighing hopper. Here, a gate part is provided at the lower part of a hopper part that temporarily stores a weighing object like a storage hopper or a weighing hopper, and the weighing object stored in the hopper part is discharged downward by releasing the gate part. . At this time, there is a problem that the hopper portion vibrates and generates noise due to opening and closing of the hopper.
As a countermeasure, according to Patent Document 1, by attaching the gate to the hopper body in a cantilever state, vibration generated when the gate is opened and closed can be reduced, and noise caused by the vibration can be reduced. A technique for reducing the amount is disclosed.
In order to maintain the weighing accuracy of the object, a method of filtering the high frequency part of the vibration is presented in order to minimize the influence of the vibration generated from the apparatus.

In addition to the above, as a countermeasure for noise reduction of the “combination weighing device”, many patents have proposed techniques for optimizing the structure and mechanism of the storage hopper, the weighing hopper, or the gate portion.
However, there is a limit to the reduction of mechanical vibration due to contact / collision of each part of the combination weighing device only with the above-mentioned structure and mechanism, so drastic measures including constituent materials are required. Yes. Moreover, although the method of making this part into resin is proposed, it is hard to become an industrial product in terms of manufacturing cost and mechanical properties.
That is, as a material for the “combination weighing device”, a material that itself has noise reduction ability and satisfies the requirements from the viewpoints of mechanical properties and price has not been conceived.

On the other hand, as the metal-based damping material, cast iron, Mn—Cu alloy, Mg—Zr alloy, Mg—Ni alloy, Al—Zn alloy, Fe—Al—Cr alloy, Ni—Ti alloy, Cu—Al— Ni alloys and the like are known.
From the viewpoint of “combination metering device” materials, cast iron and Mg-based alloys have the disadvantage of low strength. A Mn—Cu alloy has a drawback that a desired strength cannot be obtained.
The Fe—Al—Cr alloy has a drawback that the vibration damping ability is reduced by strain.
These materials are relatively excellent in vibration damping capability, but contain a lot of expensive elements, which increases the price of the alloy material and is not suitable for the above-mentioned “combination metering device” application.

  In order to solve the above problem, for example, according to Patent Document 2, a high-strength and high-damping capacity Fe—Cr—Mn alloy and a manufacturing method thereof are disclosed as materials having high mechanical strength and vibration damping capacity. ing. This patent includes a high-strength, high-damping capacity Fe-Cr-Mn consisting of 9 to 15% by weight of Cr, 18 to 26% by weight of Mn and the balance iron, and having an epsilon martensite phase of 40% by volume or more. Alloys and methods for their production are disclosed. The above-described Fe—Cr—Mn alloy is compositionally based on stainless steel. Therefore, the mechanical properties are almost the same as stainless steel and the vibration damping property is excellent, so that the invention solves the above problems from the viewpoint of the vibration damping property.

  However, the technique disclosed in Patent Document 2 discloses that the manganese weight percentage is 18 to 26% by weight. However, when this material is melted, the manganese component easily evaporates, so the yield of the added manganese alloy is poor. And, since manganese has a drawback that it significantly increases the erosion loss of the refractory used during the melting of steel, there is a problem that the industrial use is extremely limited because of the high melting cost. . Further, since the manganese weight percentage is as high as 18 to 26% by weight, there is a problem that the hot or cold working cost is increased.

On the other hand, as shown in Patent Document 3, the present inventors, as a material having vibration damping ability, have a carbon weight percentage of 0.05% by weight or less, a manganese weight percentage of 13-18% by weight, and a chromium weight percentage of 9-15% by weight. %, Nickel weight percentage 0.01-6.0 weight%, aluminum weight percentage 0.01-0.05 weight%, nitrogen weight percentage 0.01% by weight or less, and the balance iron is cold worked to form a matrix. A high-strength, high-attenuation characterized by generating 10 vol% or more of an epsilon martensite phase (hereinafter referred to as “ε-Ms phase”) in the austenite phase (hereinafter referred to as “γ-phase”) A high performance Fe-Mn-Cr-Ni alloy is proposed.
However, in Patent Document 3, a high-strength and high-damping ability alloy is recommended by a method by cold working, but it has been found that the vibration damping ability cannot be stably obtained.

  Patent Document 3 discloses that the manganese amount can be reduced to 13 to 18% by weight of manganese by adding 0.01 to 6.0% by weight of nickel. Although this technology is a countermeasure technology for reducing the manufacturing cost by lowering the manganese component by adding nickel, it is intended to improve the cold workability by adding expensive nickel, which increases the raw material cost. In other words, it is a technology that increases the cost, and it is necessary to return to the principle of the total manufacturing cost and review it again.

As a result of investigations to solve the above problems, the inventors of the present invention have found that the stacking fault energy SFE (mJ) indicates the degree of easy generation of the ε-Ms phase by heat treatment or cold working as steel having excellent vibration damping properties. / M ² ) (see Equation 5, Non-Patent Document 1) (hereinafter referred to as “SFE”), and found that the manganese amount can be reduced by partially replacing the effect of manganese by adding a small amount of silicon. Obtained knowledge to prove the effect, and filed as Patent Document 4.

JP 2005-121484 A Japanese Patent Laid-Open No. 2002-121651 JP2007-32143A Japanese Patent Application No. 2008-278829

Pickering: Proc. Conf. Stainless Steels, Gothenburg, Sept. (1984)

  According to the present invention, in a “combination weighing device” that combines objects having different weights so as to have a predetermined weight, mechanical vibration is generated due to a collision between the weighing object and the hopper part or opening / closing of the gate part. An object is to provide a low-noise and high-precision “combination weighing device” that suppresses noise caused by mechanical vibration and improves weighing accuracy by arranging steel with excellent vibration damping in the generated part. .

  The `` combination weighing device '' according to the present invention is arranged with steel having excellent vibration damping properties in a portion where mechanical vibration occurs due to collision between the weighing object and the hopper portion or opening and closing of the gate portion, The present invention is characterized in that noise due to the mechanical vibration is suppressed and measurement accuracy is improved.

In the low noise and high precision “combination weighing device” according to the present invention, the vibration damping property is excellent, which is arranged in a portion where mechanical vibration is generated due to collision between the weighing object and the hopper portion or opening and closing of the gate portion. Steel
Based on the total weight of carbon, silicon, manganese, chromium, aluminum, and balance iron of the steel,
The weight percent [% C] of carbon is 0.001 to 0.10 [%],
The weight percentage [% Si] of silicon is 0.10 to 3.0 [%],
Manganese weight percent [% Mn] 5.0 to less than 15.0 [%],
Chromium weight percent [% Cr] 0.01-20.0 [%]
Aluminum weight percentage [% Al] 0.001 to 0.10 [%]
Including the balance as iron weight percent [% Fe],
The volume% [% ε-Ms phase] of the epsilon-martensite phase measured by the X-ray diffraction method satisfies Formula 1.
[Formula 1]
10 [volume%] ≦ [% ε-Ms phase] ≦ 50 [volume%] (1)

The “combination metering device” according to the present invention is configured to include a steel having excellent vibration damping properties in which the loss factor (η) representing the vibration damping properties measured by the cantilever method satisfies Formula 2. Features.
[Formula 2]
0.005 ≤ η ≤ 0.10 (2)

The “combination weighing device” according to the present invention is
Carbon weight percent [% C], silicon weight percent [% Si], manganese weight percent [% Mn], chromium weight percent [% Cr], nickel weight percent [% Ni] and nitrogen weight percent [ % N]
The stacking fault energy (SFE) (mJ / m ² ) calculated by Equation 3 is
It is characterized by comprising steel with excellent vibration damping that satisfies Equation (4).
[Formula 3]
SFE (mJ / m ² ) = 25.7 + 2 × [% Ni] + 410 × [% C] −0.9 × [% Cr] −77 × [% N] −13 × [% Si] −1.2 × [% Mn] (3)
[Formula 4]
−20 (mJ / m ² ) ≦ SFE ≦ 20 (mJ / m ² ) (4)

The manufacturing method of steel excellent in vibration damping constituting the “combination weighing device” according to the present invention is based on the total weight of carbon, silicon, manganese, chromium, aluminum, and the balance iron.
The weight percent [% C] of carbon is 0.001 to 0.10 [%],
The weight percentage [% Si] of silicon is 0.10 to 3.0 [%],
Manganese weight percent [% Mn] 5.0 to less than 15.0 [%],
Chromium weight percent [% Cr] 0.01-20.0 [%]
Aluminum weight percentage [% Al] 0.001 to 0.10 [%]
Comprising steel,
As a first step, a step of heating at 950 to 1200 ° C. for 1 to 5 hours,
As a second step, a step of hot working at a finishing temperature of 750 to 950 ° C.,
As a third step, a step of heat treatment at 700 to 950 ° C. for 1 to 60 minutes,
As a fourth step, a step of rapidly cooling a temperature range from 500 ° C. to 20 ° C. at a cooling rate of 10 to 50 (° C./second),
The fifth step is characterized by comprising a step of performing cold working with rapid cooling or with a cold working rate of 1 to 20%.

  According to the present invention, in a “combination weighing device” that combines objects having different weights so as to have a predetermined weight, mechanical vibration is generated due to a collision between the weighing object and the hopper part or opening / closing of the gate part. Since steel with excellent vibration damping is arranged in the generated part to provide low-noise and high-precision “combination weighing device” that suppresses noise and measures to reduce weighing accuracy due to the mechanical vibration. The above contribution is great.

The low noise and high precision “combination weighing device” according to the present invention will be described in detail below.
FIG. 1 is a schematic view of a hopper portion of a low noise high precision “combination weighing apparatus” according to the present invention.

In the “combination weighing device” according to the first aspect of the present invention, the portion where mechanical vibration is generated due to the collision between the object to be measured and the hopper or the opening / closing of the gate, Insist to distribute "steel".
The above-mentioned “steel with excellent vibration damping” can effectively suppress noise generated by mechanical vibration. In addition, it is possible to improve a decrease in measurement accuracy due to mechanical vibrations or a delay in time required to specify a measurement value.

In the first aspect of the present invention, in a combination weighing device that combines objects having different weights so as to have a predetermined weight, due to a collision between the object to be weighed and the hopper part, or opening and closing of the gate part. Of the chemical composition of steel with excellent vibration damping that is placed in the part where mechanical vibration occurs,
The silicon weight percentage is 0.10 to 3.0 wt%, and the manganese weight percentage is 5.0 to less than 15.0 wt%.
This indicates that the amount of manganese can be suppressed to a low level by adding a small amount of silicon while having good damping performance.
That is, in the matter described in claim 4, in the relational expression of stacking fault energy SFE (mJ / m ² ) (Equation 3) indicating the degree to which an ε-Ms phase is easily generated by heat treatment or cold working, the term of manganese is − Since 1.2 × [% Mn] and the silicon term is −13 × [% Si], silicon has an effect of reducing SFE about 10 times that of manganese.
That is, while maintaining SFE at 20 mJ / m ² or less, the addition of a small amount of 0.10 to 3.0% by weight of silicon suppresses the manganese weight percent to 5.0 to less than 15.0% by weight. .

In claim 1, wherein matter of the present invention, the combination weighing device combining individual weights different objects so as to have a predetermined weight, due to the opening and closing of the collision and the gate portion of the metering object and the hopper Of steel with excellent vibration damping that is placed in the part where mechanical vibration occurs
It is disclosed that the volume% of the ε-Ms phase measured by X-ray diffraction method is 10 to 50 volume%.
This is a quantitative expression of the metal structure and the ε-Ms phase, which is a necessary condition for the basic vibration suppression expression of the present invention. If the volume is less than 10% by volume, the vibration damping property is insufficient. This is because the ε-Ms phases are entangled with each other when the ratio exceeds 50%, and the above-described vibration damping properties are reduced. Preferably, the ε-Ms phase volume% is 20 to 40 volume%.

In claim 1, wherein matter of the present invention, the combination weighing device combining individual weights different objects so as to have a predetermined weight, due to the opening and closing of the collision and the gate portion of the metering object and the hopper Of the chemical composition of steel with excellent vibration damping that is placed in the part where mechanical vibration occurs,
The chromium weight percentage is 0.01 to 20.0% by weight.
This relates to the γ-phase generation that is the basis of the present invention.
FIG. 2 shows a phase diagram of the Fe—Cr—Mn—Ni steel.
As is apparent from FIG. 2, in the region where the chromium weight percent exceeds 20.0 wt%, two phases of an austenite phase (γ-phase) and a ferrite phase (α-phase) are formed. 0 wt% or less, preferably 15.0 wt% or less.
Regarding the lower limit of the chromium composition ratio, by setting the range satisfying the condition that the stacking fault energy SFE (mJ / m ² ) (Equation 1) is 20 mJ / m ² or less, the synergistic effect of chromium and manganese is effectively achieved. A region where the γ-phase is generated can be widened.
Here, compared with Patent Document 3, manganese and chromium effectively play a role in the formation of γ-phase of nickel. Therefore, expensive nickel is not always necessary from the viewpoint of damping characteristics. That is, in the present invention, there is no need to intentionally add nickel unless there is a need other than the expression of vibration damping.

Further, in the combination weighing apparatus according to the first aspect of the present invention, in which the objects having different weights are combined so as to have a predetermined weight, the object is caused by the collision between the object to be measured and the hopper part or the opening / closing of the gate part. Of steel with excellent vibration damping that is placed in the part where mechanical vibration occurs.
In the chemical composition, the carbon weight percent is set to 0.10% by weight or less because a solid solution element that adversely affects the interaction between the γ-phase and the ε-Ms phase exhibiting the vibration damping ability, particularly the carbon weight percent. In order to improve and stabilize the vibration damping capacity by setting the upper limit, the loss coefficient (η) indicating the vibration damping capacity decreases and becomes unstable when the carbon weight percentage exceeds 0.10% by weight. It is.
Nitrogen, which has the same effect as carbon, is inevitably mixed by 0.020 to 0.100% by weight from the atmosphere at the time of melting and manufacturing, and reduces the vibration damping capacity. This is to eliminate the effect of inhibiting the vibration damping properties by making the nitrogen in the steel into the form of large inclusions of AlN by setting it to 0.10% by weight.
That is, if the aluminum weight percentage is less than 0.01% by weight, the aluminum weight percentage necessary for bonding with nitrogen in the steel may be insufficient. If the aluminum weight percentage exceeds 0.10% by weight, the surface of the steel material is excessive due to excess aluminum. This is because there is a risk that Al ₂ O ₃ -based defects are likely to occur inside.

In claim 1, wherein matter of the present invention, the combination weighing device combining individual weights different objects so as to have a predetermined weight, due to the opening and closing of the collision and the gate portion of the metering object and the hopper The loss factor (η) of damping steel measured by the steel cantilever method with excellent damping performance placed in the part where mechanical vibration occurs,
Although it is disclosed that it is 0.005 to 0.10, this is a basic condition as steel having excellent vibration damping properties.
Here, since the vibration damping ability of the steel according to the present invention is highly dependent on vibration strain, the loss factor (η) measurement method needs to make vibration strain about 10 ⁻⁴ or more, which is possible. The cantilever method was selected as the method.
In the measured value, if the loss factor (η) is less than 0.005, the vibration damping function as steel having excellent vibration damping properties becomes insufficient, and the steel is used in the production conditions for exceeding 0.10. This is because the mechanical properties of are not suitable for the above-described applications.

In the matter described in claim 2 of the present invention, regarding a method for producing a steel having a chemical composition defined in claim 1 and excellent in vibration damping,
A first step of heating to 950-1200 ° C. for 1-5 hours,
A second step of hot working at a finishing temperature of 750 to 950 ° C., a third step of heat treating at 700 to 950 ° C. for 1 to 60 minutes,
A fourth step of rapidly cooling a temperature region from 500 ° C. to 20 ° C. at 10 to 30 ° C./sec; and
Furthermore, the manufacturing method of the steel excellent in the damping property comprised including the 5th process which cold-processes in the range of 1-20 % at normal temperature with rapid cooling is disclosed.
Here, the important steps are the third step, the fourth step, and the fifth step.
The reason why the heat treatment temperature is set to 700 to 950 ° C. in the third step is that, at a temperature lower than 700 ° C., the cold work strain removal and austenitization are insufficient, so that the vibration damping expression is insufficient. If the temperature exceeds 950 ° C., the austenite crystal grains become coarse and the mechanical properties become poor.
In the fourth step, in order to effectively generate the thermally induced ε-Ms phase from the γ-phase to the ε-Ms phase, the cooling rate from 500 ° C. to room temperature is important. It was. This is because a heat-induced ε-Ms phase is not sufficiently generated at a cooling rate of less than 10 ° C./sec.
In the fifth step, a manufacturing method is disclosed in which the steel is further subjected to cold work of 1 to 20% to increase the volume percentage of the ε-Ms phase or to increase the strength of the steel by cold work. This can be selected according to need in order to obtain vibration damping properties, mechanical properties, or hardness necessary for the application.
Here, the cold working rate is set to 1 to 20% because the volume percentage of the ε-Ms phase generated when it exceeds 20% exceeds 50% by volume. This is because the vibration damping performance is lowered because of the inhibition.

  Hereinafter, the present invention will be described by experimental examples.

[Experimental Example 1]
Experimental Example 1 relates to claim 1 of the present invention, and is an experiment for evaluating the noise reduction ability of steel having excellent vibration damping properties according to the present invention.
FIG. 3 shows a method for generating, in a “combination weighing apparatus”, a simulation of noise generated due to a collision between a weighing object and a hopper part or opening / closing of a gate part.
That is, in Experimental Example 1, using the material of the present invention and a commercially available carbon steel as a comparative example, a box shape of 100 mm square × 300 mm height is attached to the tip with vibration generated by hanging with a thread and tapping with a hammer lightly. Measured with an accelerometer.
Table 1 shows the results. In each of the graphs, the upper graph shows the free-damping time axis waveform, and the lower graph shows the resonance frequency analysis result of the vibration. According to the frequency analysis of the vibration sound generated by the above method, all the test steels are superimposed with a relatively high resonance frequency of 200 to 2000 Hz.
It has been clarified that the steel having excellent vibration damping properties according to the present invention exhibits a good vibration absorbing ability in the above-described resonance frequency band. Further, since the noise of the hopper portion of the “combination weighing device” is the same frequency band, the effectiveness of the present invention was confirmed by this experimental example.

[Experiment 2]
Experimental Example 2 relates to claim 1 of the present invention, and is an experiment related to identification of the chemical composition of steel having excellent vibration damping properties according to the present invention.
As Experimental Example 2, steel having the composition shown in Table 2 was melted.
Here, the elements not described in Table 2 will be described. Nitrogen inevitably invades during melting and is in the range of 0.008 to 0.100%.
Both phosphorus (P) and sulfur (S) were 0.01% or less.
Nickel (Ni) was not intentionally added.
The melted steel was heated at 1000 ° C. for 2 hours, hot worked at a finishing temperature of 850 ° C., and then cold-rolled to a 1.1 mm thick cold rolled sheet . This was heat-treated in a vacuum at 800 ° C. for 1 hour and rapidly cooled in oil at room temperature. At this time, the cooling rate from 500 ° C. to room temperature was 20 ° C./second. This was further subjected to a cold rolling process of 10% in order to impart vibration damping properties.
The stacking fault energy SFE (mJ / m ² ) of this material was calculated by Equation 3.
The volume% of the ε-Ms phase in the steel was determined by the X-ray diffraction method, and the loss factor (η) was measured by the cantilever method. In this measurement method, one end is fixed with a clamp, and the size of the vibration part is 1.0 mm thickness × 50 mm width × 200 mm length (vibration part: 100 mm length), and the fixed part is 3G (3 × 980 mm / sec ² ). The loss factor (η) was obtained by measuring the free damping time and vibration frequency by applying an impact at an acceleration of. The vibration distortion at this time was 10 ⁻⁴ level.
In Table 2, symbols of good (◯) and impossible (×) are given as comprehensive evaluations.

Hereinafter, Table 2 will be described in detail.
Examples 1 to 9 of the present invention are examples in which 0.5 to 1.0% by weight of silicon, which is within the recommended range of the present invention, is added.
Here, in the example of the present invention, the SFE value is 20 mJ / m ² or less, and the volume ratio of ε-Ms phase is within the scope of the present invention, so the loss coefficient (η) is good.
In particular, in Example 5 of the present invention, 0.8% by weight of silicon is added, so that a good loss factor (η) is obtained as long as the SFE condition is satisfied even when manganese is 8% by weight and chromium is 7.0% by weight. It was confirmed that
About Comparative Examples 1 and 2, although judged from the indicators of SFE, ε-Ms phase volume% and loss factor (η), it is good (◯), but manganese is as high as 22.0 and 19.0 wt% For this reason, since the material is hard and the cold workability is poor, the production cost becomes high in mass production, so that comprehensive evaluation becomes impossible (x), which will be described in detail in the section of Experimental Example 3.
In Comparative Example 3 , the vibration damping property is poor because no silicon is added.
In Comparative Example 4 , since the amount of silicon is excessive, the material is hard and the processing cost is high, so that actual production cannot be performed.
In Comparative Example 5 , since the amount of manganese is insufficient, the vibration damping performance is poor.
In Comparative Example 6 , since the amount of chromium is excessive, the parent phase is in a two-phase region of γ-phase and α-phase, so the loss coefficient (η) is low because the amount of ε-Ms phase generated is small. It is enough.
The comparative example 7 is a case where aluminum is not added , and the damping property is insufficient because solid nitrogen is not sufficiently fixed as AlN.
Since the comparative example 8 has an excessive amount of carbon, the damping performance is poor.

[Experiment 3]
Experimental Example 3 relates to claim 1 of the present invention, and evaluates the manganese content of the steel having excellent vibration damping properties according to the present invention from the viewpoint of cold workability.
Table 3 shows different manganese (Mn) contents of the present invention example (Mn: 8%), comparative example A (Mn: 16%), comparative example B (Mn: 22%) and SUS304 (Mn: 1%). For steel, the number of intermediate heat treatments in the cold rolling from 2.0 mm to about 0.03 mm thickness and the cold rolling rate until the heat treatment is required by a test rolling mill (4-roll mill with a work roll diameter of 85 mmφ) It is measured.
In the example of the present invention , the number of intermediate heat treatments is 3 times from 2.0 mm to about 0.03 mm, and the average cold rolling ratio until the next intermediate heat treatment is 70% .
On the other hand, Comparative Example B (Mn: 22%) requires nine intermediate heat treatments, and the average cold rolling ratio until the next intermediate heat treatment is 35%. This clearly shows that the practical use is hindered because the cost of cold working is excessive in rolling costs in actual production.
The example of the present invention is confirmed to have the same cold workability as SUS304, and is a comprehensive evaluation that actual production is possible.
Here, FIG. 4 is a graph of Table 3, showing the relationship between manganese content and cold workability. It turns out that it is effective for manufacturing cost reduction to make manganese content less than 15.0%.

[Experimental Example 4]
Experimental Example 4 relates to claim 2 of the present invention.
That is, it relates to production conditions for obtaining a steel having good vibration damping properties and mechanical properties by effectively generating an ε-Ms phase that exhibits vibration damping properties. It is a demonstration.
About the example of this invention , this was heated at 1000 degreeC for 2 hours, and was hot-worked with the finishing temperature of 850 degreeC, and it was set as the hot-rolled steel plate of 3 mm thickness. This was heat-treated in a vacuum at 800 ° C. for 10 minutes. These were cooled or cold worked under the processing conditions shown in Table 4.
Table 4 shows the measurement results of these mechanical properties and loss factor (η).
Comprehensive evaluation was displayed by favorable ((circle)) and improper (x).

Table 4 will be described in detail.
Test No. 1-1 to 1-5 are cases of rapid cooling in oil after heat treatment at 800 ° C.
Test No. 2-1 to 2-5 are cases where air cooling is performed after heat treatment at 800 ° C.
In the case of quenching in oil, the ε-Ms phase is generated by quenching, so that excellent vibration damping and desired mechanical properties can be obtained by light processing.
On the other hand, in the case of air cooling, vibration suppression is imparted by increasing the cold work degree, but conversely the ductility decreases, and manufacturing conditions that satisfy both vibration suppression and mechanical properties are found. hard.

The present invention relates to a combination weighing device that combines objects having different weights so as to have a predetermined weight, and mechanical vibration occurs due to a collision between a weighing object and a hopper part or opening / closing of a gate part. In order to provide low-noise and high-accuracy “combination weighing device” that suppresses noise and measures weighing accuracy due to mechanical vibration by placing “steel with excellent vibration damping” in the part. The above contribution is great.
According to the present invention, it is possible to remarkably reduce the composition ratio of manganese, which is an essential element for producing steel having excellent vibration damping properties, and therefore it is possible to significantly reduce the production cost. Industrial use value is high.

Enlarged view of the hopper part of the “combination weighing device” according to the present invention. Phase diagram of Fe-Mn-Cr-Ni steel Generation test of mechanical vibration noise Relationship between manganese content and average cold work rate

Claims (2)

The part where mechanical vibration occurs
The carbon weight percent [% C] is 0.001 to 0.10 [%],
The weight percentage [% Si] of silicon is 0.10 to 3.0 [%],
Manganese weight percent [% Mn] is 5.0 to less than 15.0 [%]
The weight percentage of chromium [% Cr] is 0.01-20.0 [%],
Aluminum weight percentage [% Al] is 0.001 to 0.10 [%]
The balance is steel composed of iron and unavoidable impurities, and configured by rapid cooling and cold working ,
The volume percent [% ε-Ms phase] of the epsilon-martensite phase measured by the X-ray diffraction method satisfies Formula 1.
[Formula 1]
10 [volume%] ≦ [% ε-Ms phase] ≦ 50 [volume%] (1)
The loss factor (η) representing the vibration damping property measured by the cantilever method satisfies Equation 2.
[Formula 2]
0.005 ≤ η ≤ 0.10 (2)
A combination weighing device configured to include steel having excellent vibration damping properties in which the stacking fault energy (SFE) (mJ / m ² ) calculated by Expression 3 satisfies Expression 4.
[Formula 3]
SFE (mJ / m ² ) = 25.7 + 2 × [% Ni] + 410 × [% C] −0.9 × [% Cr] −77 × [% N] −13 × [% Si] −1.2 × [% Mn] (3)
[Formula 4]
−20 (mJ / m ² ) ≦ SFE ≦ 20 (mJ / m ² ) (4) Steel having excellent vibration damping properties as defined in claim 1
As a first step, a step of heating at 950 to 1200 ° C. for 1 to 5 hours,
As a second step, a step of hot working at a finishing temperature of 750 to 950 ° C.,
As a third step, a step of heat treatment at 700 to 1050 ° C. for 1 to 60 minutes,
As a fourth step, a step of rapidly cooling a temperature range from 500 ° C. to 20 ° C. at a cooling rate of 10 to 50 (° C./second),
as well as,
It is steel manufactured by the manufacturing method comprised as a 5th process including the process of performing cold processing with a cold working rate of 1 to 20 % as it is cooled, It is characterized by the above-mentioned. Combination weighing device described in 1.