Patent Description:
Many milling roll machines for grinding and splitting are installed in a flour mill for milling grain such as wheat. In order to improve quality of ground or split products, the milling roll machines are given conditions determined in regards to supply of products or raw materials, fine adjustment or the like, and provided with control means for monitoring the products or raw materials all the time during a grinding operation or after a grinding process and changing adjustment values when differences arise in a standard value (e.g., Patent Literature <NUM>).

For example, Patent Literature <NUM> describes "the determined conditions include a great many influencing factors, temperature, humidity, feed timing and heating of the whole machine or the like. In a very early period, sensuous testing methods were reevaluated or even partially demanded. This might be one of main reasons that a years-long well-known hope of automating all the milling processes could not actually be realized.

An embodiment in the above-described document describes "a temperature sensor(s) is/are attached on one side or both sides of at least one roll so as to correct dimensional deviations under influences of temperature. A temperature controller is attached to the temperature sensor. By so doing, a target value is corrected by one temperature factor. This process can also be executed at an interval. In this way, the target value is also corrected. Influences of temperature are automatically corrected and all the other factors affecting the grinding result are monitored and measured using a conventional well-known method and can be manually supplied.

That is, according to Patent Literature <NUM>, a temperature sensor is attached to a bearing casing of one or two rollers of a set of rollers, a temperature of a grinding roller is measured and an interval target value is corrected as a temperature factor, and it is possible to improve quality of a ground or split product by performing correction control through feedback when a temperature difference arises.

Note that measuring a temperature of a grinding roll and performing correction control through feedback when a temperature difference arises is disclosed not only in Patent Literature <NUM> above, but also in Non-Patent Literature <NUM>.

Pages <NUM> and <NUM> of Non-Patent Literature <NUM> include description of an article of roll temperature monitoring under the title of Safety Concept for Roller Mills. This roll temperature monitoring apparatus is provided with a plurality of temperature sensors (multi-point sensors) in a roll-axis direction, and Non-Patent Literature <NUM> describes "if a set maximum temperature is exceeded or a temperature difference between at least two of the plurality of temperature sensors exceeds <NUM>, an alarm is issued," and if "this alarm is issued, a voice signal is issued and a main motor is also stopped.

As seen in Patent Literature <NUM> above, since a rise of a surface temperature of the roll in the milling roll machine has a large influence on the quality of ground or split products, it is a well-known practice to increase a gap between rolls so as to keep a roll temperature to a set value and correct the temperature or perform correction control through feedback whereby the temperature is corrected through cooling.

Furthermore, as pointed out in Non-Patent Literature <NUM>, a plurality of temperature sensors (multi-point sensors) provided in the roll-axis direction is well known as ones to monitor surface temperatures of rolls.

However, since the temperature sensor is attached to the bearing casing of the roller according to Patent Literature <NUM> above, it is not possible to accurately detect surface temperatures of rolls. Furthermore, since the roll surfaces are monitored at points according to Non-Patent Literature <NUM> above, if a high temperature abnormality occurs between the sensors, there is a possibility that the abnormality may be overlooked. Furthermore, since a plurality of multi-point sensors are formed in the roll-axis direction, there is such a problem that if one sensor malfunctions, the roll surface temperature cannot any longer be monitored.

<CIT> discloses a method and an apparatus for milling grains, wherein at least one roll is provided with at least two temperature sensors for detecting a surface temperature of the roll.

In view of the above-described problems, it is an object of the present invention to provide a method and an apparatus for controlling a milling roll machine capable of accurately monitoring a surface temperature of a roll and preventing any high temperature abnormality occurring on a roll surface from being overlooked.

The problem is solved by the method of claim <NUM> and by the control apparatus of claim <NUM>.

That is, abnormality in roll gap or flow rate is determined by associating the surface temperature of one of the rolls with the temperature of the milled product after passing through the rolls, roll gap opening/closing control or flow rate control is thereby performed, and so it is possible to accurately monitor the surface temperatures of the rolls and there is also a merit of preventing any high temperature abnormality occurring on the roll surface from being overlooked.

Another aspect of the method for controlling a milling roll machine according to the present invention is to perform opening/closing control of the roll gap or flow rate control of the raw material stock according to a temperature of a raw material before passing through the rolls detected by the temperature sensor.

According to the other aspect of the present invention, since opening/closing control of the roll gap or flow rate control of the raw material stock is performed according to a temperature of the raw material before passing through the rolls detected by the temperature sensor, it is possible to calculate a temperature difference between the temperature of raw material grain before passing through the rolls and the temperature of the milled product after passing through the rolls, and control the roll gap or flow rate so as to prevent the temperature difference from exceeding a predetermined value. This makes it possible to prevent degradation of quality of the product due to a high temperature.

An aspect of a control apparatus for a milling roll machine according to the present invention is a control apparatus for a milling roll machine provided with at least a pair of rolls in a frame, roll gap adjusting means for driving each of the pair of rolls at different circumferential speeds and adjusting a roll gap between the pair of rolls, and stock supply means for supplying a thin layer of raw material stock between the pair of rolls, in which in the vicinity of the pair of rolls, the control apparatus provides a non-contact type temperature sensor that monitors both surface temperatures of the pair of rolls and a temperature of a milled product after passing through the rolls, and control means for performing opening/closing control of the roll gap or flow rate control of the raw material stock according to the surface temperatures of the rolls and the temperature of the milled product after passing through the rolls detected by the temperature sensor.

Another aspect of the control apparatus for a milling roll machine according to the present invention is that the control means performs opening/closing control of the roll gap or flow rate control of the raw material stock according to the temperature of the raw material stock before passing through the rolls detected by the temperature sensor.

A further aspect of the control apparatus for a milling roll machine according to the present invention is that the temperature sensor is a non-contact type thermography camera that detects infrared radiation energy radiated from an object to be detected and can visualize the energy.

A still further aspect of the control apparatus for a milling roll machine according to the present invention is that the thermography camera is provided in plurality on upper and lower sides of the pair of rolls.

A still further aspect of the control apparatus for a milling roll machine according to the present invention is that the thermography camera is formed of illumination means made up of a plurality of LED lamps, an infrared rear sensor that detects infrared radiation energy radiated from an object, a CCD area sensor that forms an image of light emitted from the object on a light receiving plane of an image pickup device and a fish-eye lens covering the infrared area sensor and the CCD area sensor.

A still further aspect of the control apparatus for a milling roll machine according to the present invention is that the thermography camera is formed of an infrared area sensor that detects infrared radiation energy radiated from an object and a fish-eye lens covering the infrared area sensor.

According to the above-described other aspects, the non-contact type temperature sensor is preferably a non-contact type thermography camera that detects infrared radiation energy radiated from the object to be detected and can visualize the energy, and particularly when the non-contact type temperature sensor is formed of illumination means made up of a plurality of LED lamps, an infrared rear sensor that detects infrared radiation energy radiated from the object, a CCD area sensor that forms an image of light emitted from the object onto a light-receiving plane of the image pickup device and a fish-eye lens covering the infrared area sensor and the CCD area sensor, it is possible to grasp a temperature distribution through the infrared area sensor and grasp a shape of the object through the CCD area sensor. The fish-eye lens allows a wide region to be monitored like a bird's eye view.

The present invention can provide a method and an apparatus for controlling a milling roll machine capable of accurately monitoring a surface temperature of a roll and preventing any high temperature abnormality occurring on the roll surface from being overlooked.

Hereinafter, an example that is not in accordance with the present invention will be described with reference to the accompanying drawings.

<FIG> is a cross-sectional view of a double milling roll machine and <FIG> is a front view of the milling roll machine in <FIG>. In <FIG> and <FIG>, reference numeral <NUM> denotes a milling roll machine, one frame <NUM> is partitioned at the center by a partition plate <NUM> or the like, providing a pair of main rolls <NUM> and <NUM>, and a pair of main rolls <NUM> and <NUM> symmetrically. The pair of main rolls <NUM> and <NUM>, and the pair of main rolls <NUM> and <NUM> are formed integrally as a pack, and the main rolls <NUM> and <NUM> come with a bearing, a housing, a seal, a spring, a roll gap adjusting apparatus or the like enabled to facilitate replacement of rolls (e.g., see <CIT>).

The main rolls <NUM> and <NUM> closer to the partition plate <NUM> of the frame <NUM> are supported by movable bearings and the main rolls <NUM> and <NUM> closer to the frame <NUM> side are rotatably supported by fixed bearings, and the main rolls <NUM> and <NUM> on the movable bearing side may be formed as low-speed rolls and the main rolls <NUM> and <NUM> on the fixed bearing side may be formed as high-speed rolls in order to drive the respective rolls at different circumferential speeds. Furthermore, if roll gap adjusting apparatuses (not shown) are interposed between the pair of main rolls <NUM> and <NUM>, and between the pair of main rolls <NUM> and <NUM>, it is possible to manually finely adjust roll gaps by turning a handle <NUM> (see <FIG>).

A lower part of a grinding chamber <NUM> surrounded by a cover <NUM> below the main rolls <NUM> and <NUM> is designated as a discharging hopper <NUM> and a transporting pipe <NUM> for transporting a stock after grinding is placed so as to face into the discharging hopper <NUM>. Furthermore, scrapers <NUM> for scraping stock adhering to the pair of main rolls <NUM> and <NUM> are respectively provided in the grinding chamber <NUM>. The scrapers <NUM> are kept in contact with surfaces of the main rolls <NUM> and <NUM> by a support body <NUM>. In a case where the pair of main rolls <NUM> and <NUM> are dressing rolls, brushes <NUM> are provided instead of scrapers. The brushes <NUM> are kept in contact with surfaces of the main rolls <NUM> and <NUM> by a support body <NUM>.

A front door <NUM> is provided on a diagonally upward side of the main rolls <NUM> and <NUM>, and stock supply means <NUM> is provided between the front door <NUM> and the partition plate <NUM>. The stock supply means <NUM> is constructed of a stock supply chamber <NUM> formed of a stock supply cylinder <NUM>, a supply hopper <NUM> communicating with the stock supply chamber <NUM>, a pair of front and back feed rolls <NUM> and <NUM> provided to supply a thin layer of stock to the milling rolls, a feeder gate plate <NUM> located above the front-side feed roll <NUM> of the pair of feed rolls <NUM> and <NUM>, a guide plate <NUM> provided on a side of the supply hopper <NUM>, and a guide chute <NUM> that causes the thin layer stock discharged from the pair of feed rolls <NUM> and <NUM> to flow down to the main rolls <NUM> and <NUM> for milling.

Outer circumferences of the pair of main rolls <NUM> and <NUM> are covered with a plurality of roll covers. That is, the main rolls <NUM> and <NUM> are covered with a top cover <NUM> and an outside cover <NUM>. A pneumatic pipe <NUM> that transports the stock after grinding by the milling roll machine <NUM> to a subsequent process is disposed at a vertex of the stock supply cylinder <NUM>.

The main rolls <NUM> and <NUM> are provided with sensors S for monitoring surface temperatures of the main rolls <NUM> and <NUM> or monitoring temperatures of milled products (grain) passing through the main rolls <NUM> and <NUM>. As the sensors S, it is preferable to dispose a sensor S1 in a gap between the outside cover <NUM> and the frame <NUM> for monitoring the main roll <NUM> side, a sensor S2 in the vicinity of the partition plate <NUM> for monitoring the main roll <NUM> side, a sensor S3 in the vicinity of the partition plate <NUM> for monitoring the main roll <NUM> side, and a sensor S4 in a gap between the outside cover and the frame <NUM> for monitoring the main roll <NUM> side.

For example, a thermography camera may be preferably used as the sensors S for monitoring the surface temperatures of the rolls or monitoring temperatures of the milled products passing through the rolls. The "thermography camera" refers to an apparatus that detects infrared radiation energy radiated from an object to be detected, enables visualization and performs temperature measurement and image display of temperature distribution. The thermography camera has a variety of advantages: a wide range of monitoring region, ability to safely perform measurement even in dangerous places, ability to perform measurement even in places where it is not possible to use a contact type thermometer such as a thermocouple, and ability to perform measurement even in the dark.

When used for the milling roll machine <NUM> of the depicted example, the thermography camera can display images with a temperature distribution over an entire region in the axial direction for even lengthy rolls having a length on the order of <NUM> to <NUM>. In embodiments of the present invention, the thermography camera can also simultaneously display images of temperature distributions of four kinds of temperatures: a temperature of raw material grain located above the roll and before passing through the roll, a temperature of a milled product nearest to the roll and when passing through the roll, and a temperature of a milled product located below the roll and after passing through the role in addition to a surface temperature of the roll. This will greatly contribute to quality management of products.

<FIG> are schematic views illustrating an arrangement configuration of the sensors S when monitoring surface temperatures of the rolls simultaneously with a temperature of grain passing through the rolls according to an embodiment of the present invention.

Referring to <FIG>, since the sensors S are arranged on the sides of (just beside) the main rolls <NUM> and <NUM>, and viewing angles of the sensors S range from substantially <NUM> to <NUM>°, it is possible to acquire four kinds of temperatures: temperature at the roll surface, temperature of the raw material grain, temperature of the milled product while passing through the roll and temperature of the milled product after passing through the rolls. Since only one sensor needs to be disposed for the pair of rolls <NUM> and <NUM>, it is possible to reduce the manufacturing cost.

Referring to <FIG>, a sensor S-Up is disposed diagonally above the main rolls <NUM> and <NUM> and a sensor S-Low is disposed diagonally below the main rolls <NUM> and <NUM>. In this way, the sensor S-Up is responsible for monitoring the temperature on the top side of the roll surface and the temperature region of raw material grain, while the sensor S-Low is responsible for monitoring the temperature region of the milled product after passing through the rolls. Since the two sensors S-Up and S-Low share monitoring of the temperature region, it is possible to obtain a more accurate and more detailed temperature distribution.

<FIG>, and <FIG> are schematic configuration diagrams of the thermography camera applied to the milling roll machine <NUM> of the present invention. <FIG> in particular, illustrate a high function type configuration provided with an infrared area sensor, a CCD area sensor and a light source LED lamp, and <FIG> illustrate an inexpensive configuration provided with only an infrared area sensor.

<FIG> is a schematic configuration diagram of a lateral side of the thermography camera and <FIG> is a schematic configuration diagram of a front side. Referring to <FIG>, the thermography camera <NUM> is constructed of a plurality of LED lamps 33a to 33d which serve as illumination means, an infrared area sensor <NUM> that detects infrared radiation energy radiated from an object, a CCD area sensor <NUM> that forms an image of light emitted from the object on a light receiving surface of an image pickup device and a fish-eye lens <NUM> covering the infrared area sensor <NUM> and the CCD area sensor <NUM>, all of which are mounted on a camera drive substrate <NUM> incorporated in the camera case <NUM>.

As shown in <FIG>, the high function type thermography camera <NUM> provided with the infrared area sensor <NUM>, the CCD area sensor <NUM> and the LED lamps <NUM> can grasp a temperature distribution through the infrared area sensor <NUM>, grasp the shape of the object through the CCD area sensor <NUM>, and it is thereby possible to instantaneously grasp which region of the object has a high or low temperature using an image synthesis technique.

<FIG> is a block diagram of the high function type thermography camera shown in <FIG> when performing image determination processing. Referring to <FIG>, the infrared area sensor <NUM> and the CCD area sensor <NUM> are electrically connected to plane image conversion sections <NUM> and <NUM> in a central computation control apparatus <NUM> respectively. That is, these sensors are covered with the fish-eye lens <NUM> and thereby provide equidistant projection images taken with a wide viewing angle, and the plane image conversion sections <NUM> and <NUM> are used to convert the equidistant projection images to plane images. An electric signal from the plane image conversion section <NUM> on the infrared area sensor <NUM> side is inputted to an abnormality determination analyzing section <NUM> and also inputted to an image synthesis processing section <NUM>, and on the other hand, an electric signal from the plane image conversion section <NUM> on the CCD area sensor <NUM> side is only inputted to the image synthesis processing section <NUM>. Here, the abnormality determination analyzing section <NUM> can determine an abnormality in the roll gap or flow rate through a temperature distribution, a temperature difference or the like in the region of an object which will be described later. Furthermore, the image synthesis processing section <NUM> can grasp the shape of the object through the CCD area sensor <NUM> and at the same time can grasp which region of the object has a high or low temperature through the infrared area sensor <NUM>. The output of an electric signal from the abnormality determination analyzing section <NUM> is controlled by various actuators which will be described later and an electric signal from the image synthesis processing section <NUM> is outputted to an operation & display section <NUM> provided with a liquid crystal screen which will be described later.

On the other hand, <FIG> is a schematic configuration diagram of the lateral side of the thermography camera provided with only the infrared area sensor and <FIG> is a schematic configuration diagram of the front side. Referring to <FIG>, the thermography camera <NUM> is constructed of the infrared area sensor <NUM> and the fish-eye lens <NUM> covering the infrared area sensor <NUM> on the camera drive substrate <NUM> incorporated in the camera case <NUM>.

As shown in <FIG>, the inexpensive type thermography camera <NUM> provided with only the infrared area sensor <NUM> makes it possible to instantaneously grasp which region of the object has a high or low temperature by defining the shape of the object in advance and performing sensing, and can be provided at low cost.

<FIG> is a block diagram illustrating a control configuration of the milling roll machine provided with the thermography camera of the present invention.

As shown in <FIG>, <FIG> and <FIG>, the control configuration of the milling roll machine includes an operation & display section <NUM> incorporated in the frame <NUM> of the milling roll machine and made operable by directly touching a liquid crystal screen and the thermography camera <NUM>, both of which constitute a main input section, and are electrically connected to the central computation control apparatus <NUM>. Other input sections include a stock level sensor <NUM>, a feed roll rotation sensor <NUM> and a main motor load current sensor <NUM>, which are electrically connected to the central computation control apparatus <NUM>.

On the other hand, the output section is constructed of a right end roll gap motor <NUM> that automatically adjusts the gap on one end side of the main rolls <NUM> and <NUM>, a left end roll gap motor <NUM> that automatically adjusts the gap on the other end side of the main rolls <NUM> and <NUM>, a feed roll motor <NUM>, a main motor <NUM> and an alarm buzzer <NUM>, all of which are electrically connected to the central computation control apparatus <NUM>. Various actuators can thereby be operated.

Hereinafter, operations in the above-described configuration will be described with reference to the attached drawings.

<FIG> and <FIG> are explanatory diagrams illustrating the front view in <FIG> partially exploded such that the vicinity of the main rolls <NUM> and <NUM> is exposed.

In <FIG>, an observation region by the thermography camera <NUM> is denoted by reference character R, and the thermography camera <NUM> acquires three temperatures: surface temperatures of the main rolls <NUM> and <NUM>, a temperature of a milled product while passing through the rolls, and a temperature of the milled product after passing through the rolls. Suppose that a situation has been detected by the thermography camera <NUM> in which a surface temperature at a specific location T of the main rolls <NUM> and <NUM> is lower than a peripheral temperature and a temperature of a milled product F below the main rolls <NUM> and <NUM> is also lower than the peripheral temperature. In this case, it is recognized that the raw material is not flowing uniformly in the axial direction of the main rolls <NUM> and <NUM>. That is, it can be assumed that the raw material is not flowing only through the specific location T resulting in a biased flow. At this time, the alarm buzzer <NUM> may be sounded as a roll gap abnormality and an abnormality cause may be displayed on the liquid crystal screen of the operation & display section <NUM>. The roll gap abnormality is, for example, a state in which the main rolls <NUM> and <NUM> are not parallel to each other and the right end or left end is open in a "truncated chevron" shape. Since the milling roll is a lengthy roll having a length on the order of <NUM> to <NUM>, a biased flow of the raw material is generated even when there is a slight difference in the gap at the right end or left end.

Therefore, the central computation control apparatus <NUM> drives the right end roll gap motor <NUM> or the left end roll gap motor <NUM> and performs automatic control so that the roll gap becomes appropriate. Without being limited to such automatic control, the operator may determine a cause for the abnormality displayed on the liquid crystal screen, operate the handles <NUM>, <NUM> to manually adjust the roll gap to an appropriate value.

Furthermore, in <FIG>, suppose that the thermography camera <NUM> detects a situation in which the surface temperature at the specific location T at the left end of the main rolls <NUM> and <NUM> is higher than a peripheral temperature and the temperature of the milled product F below the main rolls <NUM> and <NUM> is also higher than the peripheral temperature. In this case, it is assumed that the roll gap at the specific location T is narrow, the roll gap at the right end of the main rolls <NUM> and <NUM> is wide ("truncated chevron" shape as described above), and the raw material is not flowing uniformly in the axial direction of the main rolls <NUM> and <NUM>. At this time, the alarm buzzer <NUM> may be sounded as a roll gap abnormality and an abnormality cause may be displayed on the liquid crystal screen of the operation & display section <NUM>. In this way, the central computation control apparatus <NUM> drives the right end roll gap motor <NUM> or the left end roll gap motor <NUM> and performs automatic control so that the roll gap becomes appropriate. Without being limited to this, the operator may determine a cause for the abnormality displayed on the liquid crystal screen, operate the handles <NUM>, <NUM> to manually adjust the roll gap to an appropriate value.

In addition, of the observation region R, the thermography camera <NUM> may monitor only the temperature of the milled product after passing through the rolls. That is, the thermography camera <NUM> may control the roll gap or the flow rate so that the temperature of the milled product after passing through the rolls becomes uniform and the temperature of the milled product does not become excessively high. For example, when the thermography camera <NUM> detects that the temperature of the milled product exceeds <NUM>, the roll gap may be controlled to an appropriate value or control may be performed to suppress the flow rate. The flow rate control may be enabled by controlling rotation of the feed roll motor <NUM>. This makes it possible to prevent degradation of quality of the product due to a high temperature and obtain a product resulting from uniformly milling the raw material. Moreover, the yield in a post process will also improve and milling efficiency will improve, which leads to energy saving as well.

Furthermore, of the observation region R, the thermography camera <NUM> may monitor a temperature of the raw material grain above the rolls and before passing through the rolls and a temperature of the milled product after passing through the rolls. That is, the thermography camera <NUM> may calculate a temperature difference between the temperature of the raw material grain before passing through the rolls and the temperature of the milled product after passing through the rolls, and control the roll gap or flow rate so as to prevent the temperature difference from exceeding a predetermined value. This makes it possible to prevent degradation of quality of the product due to a high temperature.

As described above, according to the present embodiment, the non-contact type temperature sensor S for monitoring both the surface temperature of the pair of main rolls <NUM> and <NUM> and the temperature of the milled product after passing through the rolls is provided in the vicinity of the pair of main rolls <NUM> and <NUM>, and opening/closing control of the roll gap or flow rate control of the raw material stock is performed according to the surface temperatures of the rolls and the temperature of the milled product after passing through the rolls detected by the temperature sensor S, and therefore it is possible to monitor the temperature in the vicinity of the pair of rolls over a wide region like a bird's eye view using the non-contact type temperature sensor S and monitor not only the surface temperatures of the rolls but also the temperature of the milled product after passing through the rolls. That is, since an abnormality in the roll gap or flow rate is determined by associating the surface temperatures of the rolls with the temperature of the milled product after passing through the rolls, and opening/closing control of the roll gap or flow rate control is thereby performed, there is a merit that it is possible to accurately monitor the surface temperatures of the rolls and prevent any high temperature abnormality occurring on a roll surface from being overlooked.

Claim 1:
A method for controlling a milling roll machine (<NUM>) comprising:
at least a pair of rolls (<NUM>, <NUM>, <NUM>, <NUM>) in a frame (<NUM>);
a roll gap adjusting mechanism for driving each of the pair of rolls (<NUM>, <NUM>, <NUM>, <NUM>) at different circumferential speeds and adjusting a roll gap between the pair of rolls (<NUM>, <NUM>, <NUM>, <NUM>); and
a stock supply mechanism for supplying a thin layer of raw material stock between the pair of rolls (<NUM>, <NUM>, <NUM>, <NUM>), wherein
a non-contact type temperature sensor (S) is provided in the vicinity of the pair of rolls (<NUM>, <NUM>, <NUM>, <NUM>), wherein the temperature sensor (S) monitors a surface temperature of one of the pair of rolls (<NUM>, <NUM>, <NUM>, <NUM>) as well as a temperature of a milled product after passing through the rolls (<NUM>, <NUM>, <NUM>, <NUM>), and
opening/closing control of the roll gap or flow rate control of the raw material stock is performed according to the surface temperature of one of the rolls (<NUM>, <NUM>, <NUM>, <NUM>) and the temperature of the milled product after passing through the rolls (<NUM>, <NUM>, <NUM>, <NUM>) detected by the temperature sensor (S).