JP6225032B2 - Thermocouple inspection device and thermocouple inspection method - Google Patents

Description

  The present invention is a technique for inspecting a thermocouple used to measure the temperature of a kneaded product being produced by a kneader.

  The manufacturing process of rubber products and plastic products includes a process of kneading a plurality of materials to be rubber and plastic to produce a kneaded product. The temperature of the kneaded product is used as an index indicating the degree of kneading of the plurality of materials. For this reason, the temperature of the kneaded product is measured during the generation of the kneaded product.

  A thermocouple is used to measure the temperature of the kneaded product. Since the kneaded product has a high viscosity, if the thermocouple strand is brought into contact with the kneaded product being produced, the thermocouple strand is broken. For this reason, the thermocouple which has the structure which accommodated the thermocouple strand in the tubular member is utilized. Examples of such a thermocouple include a protective tube type thermocouple and a sheath thermocouple.

  The protective tube type thermocouple is a thermocouple having a structure in which a thermocouple element is housed in a protective tube made of metal or ceramic. The sheath thermocouple is a thermocouple having a structure in which a thermocouple element is housed in a very thin metal tube called a sheath and high purity inorganic insulating powder is filled inside the sheath.

  Since the thermocouple deteriorates with use, a technique for detecting the deterioration of the thermocouple has been proposed. For example, as a technique for detecting deterioration of a protection tube type thermocouple, there is a thermocouple deterioration detection device disclosed in Patent Document 1. The apparatus includes a first thermocouple having a tip portion provided on a measurement target, a second thermocouple shorter than the first thermocouple provided close to the first thermocouple, a first thermocouple, The output of the thermocouple and the output of the second thermocouple are compared. When the output difference between the two thermocouples exceeds a predetermined value, it is determined that the first thermocouple has deteriorated, and a deterioration detection signal is generated. And a processing means.

JP-A-9-218107 (summary)

  Rubber and plastic materials include particles with high hardness such as silica. For this reason, in the surface of tubular members, such as a protection tube and a sheath, since the part which contacts a kneaded material is worn out gradually, the strength of a tubular member falls. As a result, the tubular member may be bent or damaged during the production of the kneaded product. In particular, if the tubular member is broken, the broken pieces are mixed with the kneaded material, causing a rubber product or plastic product to become a defective product.

  The thermocouple deterioration detection apparatus introduced as the above prior art is an apparatus for detecting deterioration of a thermocouple wire, and is not an apparatus for inspecting wear of a portion in contact with the kneaded material. Therefore, a technique capable of inspecting the wear at that location is desired.

  The present invention relates to a thermocouple inspection apparatus and a thermocouple that are provided in a thermocouple used for measuring the temperature of a kneaded product and that can inspect whether a portion that contacts the kneaded product is worn in a tubular member that accommodates a thermocouple wire. The purpose is to provide an inspection method.

  The thermocouple inspection apparatus according to the first aspect of the present invention is a kneading machine including a kneading chamber, a door portion that is opened when the kneaded material is taken out from the kneading chamber, and a location in contact with the kneaded material. A temperature measuring device for measuring the temperature of the kneaded material generated in the kneading chamber using a thermocouple including a tubular member having a contact point and a thermocouple element housed in the tubular member; A thermocouple inspection device applied to a system comprising: a current supplied to the thermocouple wire in a first predetermined period with the door portion opened; and the first A current supply control unit that stops supplying current to the thermocouple element after the elapse of a period of time, and an equation for estimating a decrease in temperature measured by the temperature measuring device after the elapse of the first period An expression calculating unit for calculating A subtracting unit that calculates a subtracted value obtained by subtracting the temperature indicated by the formula calculated by the formula calculating unit from the temperature measured by the temperature measuring device after a lapse of time, and the contact location is worn based on the subtracted value. A wear determination unit that determines whether the wear determination is performed, and a notification unit that notifies a result determined by the wear determination unit.

  In the thermocouple inspection device according to the first aspect of the present invention, when the contact location is worn, the temperature measurement is performed when current is supplied to the thermocouple wire, compared to the case where the contact location is not worn. The wear at the contact point is determined using the fact that the temperature rise measured by the device is increased.

  When the wear inspection of the contact portion is performed in a state where the door portion of the kneading chamber is opened, it is necessary to eliminate the influence that the temperature measured by the temperature measuring device is rapidly lowered by opening the door portion.

  The temperature measured by the temperature measuring device when current is supplied to the thermocouple element in the state where the door is opened is defined as the actual temperature. When it is assumed that no current is supplied to the thermocouple element in a state where the door portion is opened, a temperature estimated to be measured by the temperature measuring device is set as an estimated temperature. In the present invention, the temperature indicated by the formula calculated by the formula calculation unit is used as the estimated temperature. The amount of temperature increase measured by the temperature measuring device due to the heat generated at the temperature measuring contact of the thermocouple wire due to the current supplied to the thermocouple wire is defined as the temperature increase amount.

  If the estimated temperature is subtracted from the actual temperature, the above influence can be eliminated. That is, the value obtained by subtracting the estimated temperature from the actual temperature is the temperature rise amount.

  As described above, according to the thermocouple inspection apparatus according to the first aspect of the present invention, in the tubular member that is provided in the thermocouple used for measuring the temperature of the kneaded material and that accommodates the thermocouple strand, It is possible to inspect whether the contact point is worn.

  In the above configuration, a period elapsed determination unit that determines whether a predetermined second period has elapsed after the first period has elapsed, and the formula calculation unit includes the second period After the time elapses, the equation is calculated using the temperature measured by the temperature measurement device during a predetermined sampling period.

  By supplying a current to the thermocouple element in the first period, the temperature measuring contact of the thermocouple element generates heat. A period in which this influence remains is the second period, and a period in which the influence does not remain is the sampling period. According to this configuration, since the above equation is calculated using the temperature measured by the temperature measurement device during the sampling period in which the influence does not remain, it is possible to accurately estimate the decrease in temperature measured by the temperature measurement device. .

  The said structure WHEREIN: The said contact location contains a plating layer.

  In order to increase the wear resistance of the material of the kneaded material, there is a thermocouple having a plated layer as a contact portion. However, the plating layer is also worn by long-term use of the thermocouple. In this configuration, the present invention is applied to a thermocouple having a plated layer as a contact portion.

  The thermocouple inspection method according to the second aspect of the present invention is a kneading machine including a kneading chamber, a door portion that is opened when the kneaded material is taken out from the kneading chamber, and a location in contact with the kneaded material. A temperature measuring device for measuring the temperature of the kneaded material generated in the kneading chamber using a thermocouple including a tubular member having a contact point and a thermocouple element housed in the tubular member; A thermocouple inspection method applied to a system comprising: supplying a current to the thermocouple wire in a first predetermined period with the door portion opened; and A current supply control step for stopping the supply of current to the thermocouple element after the elapse of the period, and an equation for estimating a decrease in temperature measured by the temperature measuring device after the elapse of the first period. A formula calculating step for calculating Based on the subtraction value, a subtraction step for calculating a subtraction value obtained by subtracting the temperature indicated by the equation calculated by the equation calculation step from the temperature measured by the temperature measurement device after the elapse of the first period, A wear determination step for determining whether the contact portion is worn and a notification step for notifying a result determined by the wear determination unit.

  The thermocouple inspection method according to the second aspect of the present invention defines the thermocouple inspection device according to the first aspect of the present invention as a method, and the thermocouple inspection device according to the first aspect of the present invention. Has the same effect as

  A thermocouple inspection apparatus according to a third aspect of the present invention inspects a thermocouple including a tubular member having a contact location that is a location in contact with a kneaded material, and a thermocouple element housed in the tubular member. A thermocouple inspection device for supplying current to the thermocouple element in a first predetermined period and supplying current to the thermocouple element after the first period has elapsed. A current supply control unit that stops the operation, a period elapse determination unit that determines whether or not a predetermined second period elapses after the first period elapses, and the thermocouple Among the temperatures measured in the first period, using the temperature measured in the sampling period after the period determination unit determines that the second period has elapsed. If no current is supplied to the second period, When measuring the temperature using the thermocouple, an approximate expression calculation unit that calculates an approximate expression indicating the temperature estimated to be measured, and the temperature measured using the thermocouple during the second period From the subtraction unit that calculates a subtraction value obtained by subtracting the temperature indicated by the approximate expression calculated by the approximate expression calculation unit, a wear determination unit that determines whether the contact location is worn based on the subtraction value, A notifying unit for notifying a result determined by the wear determining unit.

  According to the thermocouple inspection device according to the third aspect of the present invention, the thermocouple inspection device according to the first aspect of the present invention is provided in the thermocouple used for measuring the temperature of the kneaded material for the same reason. In the tubular member in which the thermocouple wire is accommodated, it can be inspected whether or not the portion in contact with the kneaded material is worn.

  ADVANTAGE OF THE INVENTION According to this invention, it can test | inspect whether the location which contacts with a kneaded material is abraded in the tubular member with which the thermocouple used for the measurement of the temperature of a kneaded material is accommodated.

It is a schematic diagram which shows an example of a kneading machine. In the kneader shown in FIG. 1, it is a schematic diagram which shows the state in which the kneaded material is produced | generated. In the kneader shown in FIG. 1, it is a schematic diagram which shows the state from which the kneaded material is taken out. It is a schematic diagram which shows an example of the temperature measuring apparatus using a protection tube type thermocouple. It is a graph which shows the relationship between the time which supplied the electric current to the thermocouple strand, and the temperature rise amount. It is a block diagram which shows the structure of the thermocouple inspection apparatus which concerns on this embodiment. It is a time chart which shows the period of a wear inspection. It is a flowchart explaining operation | movement of the thermocouple inspection apparatus which concerns on this embodiment. It is a graph which shows the temperature which the temperature measurement apparatus measured in the 2nd period and the sampling period. It is a graph which shows the approximate expression which the approximate expression calculation part calculated in the 2nd period and the sampling period. 11 is a graph obtained by superimposing the graph of FIG. 9 and the graph of FIG. It is a graph which shows the value which subtracted the value which the graph of FIG. 10 shows from the value which the graph of FIG. 9 shows.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram illustrating an example of a kneader 3. FIG. 2 is a schematic diagram showing a state in which a kneaded product M is generated in the kneader 3 shown in FIG. FIG. 3 is a schematic diagram showing a state in which the kneaded material M is taken out in the kneader 3 shown in FIG.

  Referring to FIG. 1, the kneader 3 includes a material supply pipe 31, a kneading chamber 32, a door part 33, a generation control part 37, and a door control part 38.

  The material supply pipe 31 is disposed on the ceiling of the kneading chamber 32. The tip of the material supply pipe 31 is guided to the kneading chamber 32 through the ceiling of the kneading chamber 32. The material of the kneaded material M is supplied to the kneading chamber 32 through the material supply pipe 31.

  The kneading chamber 32 is shown in a sectional view. The kneading chamber 32 is set to a temperature higher than normal temperature when a predetermined material is kneaded to produce the kneaded material M. For example, in the case of a rubber kneaded product, the kneading chamber 32 is set to a few tens of degrees Celsius. In the kneading chamber 32, two rollers 34 and 35 are arranged. Referring to FIG. 2, by rotating two rollers, the material supplied to kneading chamber 32 is kneaded, and kneaded material M is generated.

  The generation control unit 37 controls the generation of the kneaded material M in the kneading chamber 32. More specifically, the generation control unit 37 performs control for supplying the material of the kneaded material M from the material supply pipe 31 to the kneading chamber 32, control for setting the temperature of the kneading chamber 32, and control for rotating the rollers 34 and 35. To do.

  With reference to FIGS. 1 and 3, an outlet 36 for the kneaded material M is formed in the floor of the kneading chamber 32. When the door portion 33 is closed, the outlet 36 is closed. When the door portion 33 is opened, the take-out port 36 is opened. When the door 33 is opened, the kneaded material M in the kneading chamber 32 falls through the outlet 36 and is sent to the next process. The door portion 33 is closed when the kneaded material M is generated in the kneading chamber 32, and is opened when the kneaded material M is taken out from the kneading chamber 32.

  The door control unit 38 controls opening and closing of the door unit 33.

  The kneading machine 3 operates to generate the kneaded material M in the kneading chamber 32, to open the door portion 33 to take out the generated kneaded material M from the kneading chamber 32, and to generate the next kneaded material M in the kneading chamber 32. The operation of closing the door 33 is repeated.

  With reference to FIG. 1, a protective tube type thermocouple 5 is inserted into the door portion 33. With the door 33 closed, the distal end 53 of the protective tube 51 of the protective tube type thermocouple 5 is located in the kneading chamber 32, and with the door 33 opened, the distal end 53 is the kneading chamber. The front end portion 53 protrudes from the door portion 33 so as to be located outside the door 32. The tip portion 53 is a contact portion that comes into contact with the kneaded material M during the generation of the kneaded material M.

  FIG. 4 is a schematic view showing an example of the temperature measuring device 6 using the protective tube type thermocouple 5. The temperature measuring device 6 includes a protective tube type thermocouple 5 and a temperature calculation unit 7.

  The protective tube type thermocouple 5 includes a protective tube 51 and a thermocouple wire 52.

  The protective tube 51 is an example of a tubular member, and houses the thermocouple wire 52. The tip 53 of the protective tube 51 is shown in a sectional view.

  The thermocouple wire 52 is composed of two strands 52a and 52b. The two strands 52a and 52b are insulated from each other by an insulating tube 54. One end of the thermocouple wire 52 includes a temperature measuring contact 52 c and is exposed from the insulating tube 54. The temperature measuring contact 52 c is welded to the distal end portion 53 of the protective tube 51.

  The tip 53 of the protective tube 51 is covered with a plating layer 55. That is, the distal end portion 53 of the protective tube 51 is the distal end portion 53 including the plating layer 55. In the front end portion 53 including the plating layer 55, the plating layer 55 becomes a contact location. The plated layer 55 will be described in detail later.

  Terminals 56 a and 56 b are provided on the rear end surface of the protective tube 51. The element wire 52a is electrically connected to the external wiring 57a by a terminal 56a. The element wire 52b is electrically connected to the external wiring 57b through a terminal 56b.

  The thermocouple applied to the present embodiment is not limited to the protective tube type thermocouple 5, but may be any thermocouple having a structure in which the thermocouple element 52 is accommodated in a tubular member (for example, a sheathed thermocouple).

  The temperature calculation unit 7 is electrically connected to the external wirings 57a and 57b. The thermocouple wire 52 generates a thermoelectromotive force by the heat transmitted to the temperature measuring contact 52c. The thermoelectromotive force is transmitted to the temperature calculation unit 7 through the external wirings 57a and 57b. The temperature calculation unit 7 calculates the temperature (for example, the temperature of the kneaded material M in the kneading chamber 32 shown in FIG. 2) using the transmitted thermoelectromotive force. Thus, the temperature measuring device 6 is a device that measures the temperature using the thermoelectromotive force generated by the thermocouple wire 52.

  The plated layer 55 will be described. As described above, the distal end portion 53 of the protective tube 51 is a contact location. The material of the protective tube 51 is, for example, SCM material (chrome molybdenum steel) from the viewpoint of heat resistance, strength, and the like. Rubber and plastic materials include particles with high hardness such as silica. The SCM material has low wear resistance with respect to silica. Therefore, the plating layer 55 is formed on the distal end portion 53 of the protective tube 51, and the plating layer 55 is used as a contact location, thereby improving the wear resistance of the contact location.

  Thus, by making the contact portion into the plated layer 55, the wear resistance of the contact portion is improved. However, since the plated layer 55 is also worn by silica, when the protective tube type thermocouple 5 is used for a long time, the plated layer 55 is worn and the plated layer 55 is peeled off from the protective tube 51.

  Therefore, it is necessary to inspect whether the plating layer 55 is worn. In the present embodiment, the thermocouple inspection is this inspection. Hereinafter, this inspection may be simply referred to as “abrasion inspection”.

  When a current is supplied to the thermocouple wire 52, the temperature measuring contact 52c generates heat. The heat is absorbed by the tip 53 of the protective tube 51. The tip portion 53 that does not include the plating layer 55 has a smaller amount of heat absorption at the tip portion 53 than the tip portion 53 that includes the plating layer 55 because the plating layer 55 is not present. Therefore, the tip 53 that does not include the plated layer 55 has a higher temperature at the temperature measuring contact 52 c when current is supplied to the thermocouple wire 52 than the tip 53 that includes the plated layer 55 (that is, The temperature measured by the temperature measuring device 6 becomes higher). An experiment was conducted to confirm this.

  While continuously supplying a current of 1.0 A to the thermocouple element 52 of the protective tube type thermocouple 5, the temperature was measured at predetermined time intervals by the temperature measuring device 6.

  As the protective tube type thermocouple 5, a protective tube type thermocouple 5 with an aluminum foil and a protective tube type thermocouple 5 without an aluminum foil were prepared. The protective tube type thermocouple 5 with aluminum foil is a protective tube type thermocouple 5 in which an aluminum foil is attached to the distal end portion 53 of the protective tube 51. The protective tube type thermocouple 5 without the aluminum foil is a protective tube type thermocouple 5 in which the aluminum foil is not attached to the distal end portion 53 of the protective tube 51. The thickness of the aluminum foil was 0.12 mm. Aluminum foil was considered as the plating layer 55.

  The result of the experiment is shown in the graph of FIG. The horizontal axis of the graph indicates the time that has elapsed since the supply of current to the thermocouple element 52 was started. The unit is seconds. The vertical axis of the graph indicates the amount of temperature rise based on the temperature measured by the temperature measuring device 6 before the current is supplied to the thermocouple wire 52.

  For example, the temperature measured by the temperature measuring device 6 is 30.0 ° C. before the current is supplied to the thermocouple wire 52, and 10 seconds have elapsed since the current was supplied to the thermocouple wire 52. The temperature measured by the temperature measuring device 6 is 31.0 ° C. In this case, the amount of temperature increase when 10 seconds have elapsed since the current was supplied to the thermocouple element 52 is 1.0 ° C.

  A broken line S1 indicates the experimental result of the protective tube type thermocouple 5 with aluminum foil. The line L1 is a line obtained by linearly approximating the broken line S1. A broken line S2 indicates the experimental result of the protective tube type thermocouple 5 without the aluminum foil. The line L2 is a line obtained by linearly approximating the broken line S2.

  The protection tube type thermocouple 5 without aluminum foil indicated by the broken line S2 has a larger temperature rise than the protection tube type thermocouple 5 with aluminum foil indicated by the broken line S1. This seems to be due to the absence of aluminum foil.

  For example, when the time for supplying the current to the thermocouple wire 52 is 10 seconds, the temperature rise in the protective tube thermocouple 5 with aluminum foil indicated by the broken line S1 is 1.0 ° C. and indicated by the broken line S2. In the protective tube type thermocouple 5 without the aluminum foil, the temperature increase was 1.3 ° C.

  This is because the temperature rise amount is 1.0 ° C. in the protective tube type thermocouple 5 in which the plated layer 55 is not cut, and the temperature rise amount is in the protective tube type thermocouple 5 in which the plated layer 55 is cut off by 0.12 mm. It can be said that a difference of 0.3 ° C. occurs in the temperature increase amount.

  If the thickness of the plating layer 55 is reduced in the tip portion 53 including the plating layer 55, the heat absorption amount of the tip portion 53 is reduced. Therefore, if the thickness of the plating layer 55 decreases between the thickness of the plating layer 55 and the temperature rise of the temperature measuring contact 52c, the temperature rise of the temperature measuring contact 52c (in other words, the temperature measuring device). 6 is considered to have a correlation in which the amount of increase in temperature measured) increases. Therefore, the thickness (wear amount) of the plating layer 55 is estimated using the temperature increase measured by the temperature measuring device 6 by supplying current to the thermocouple wire 52 to generate heat at the temperature measuring contact 52c. it can. In the present embodiment, this theory is applied to inspect whether or not the plated layer 55 that is a contact point is worn (wear inspection).

  Next, the timing for executing the wear inspection will be described. Referring to FIG. 2, since the tip 53 of the protective tube 51 is in contact with the kneaded material M during the generation of the kneaded material M, the wear inspection cannot be performed. It is conceivable that the kneading machine 3 is stopped and the wear inspection is performed in a state where the kneaded material M does not exist in the kneading chamber 32. However, since the production process of the kneaded material M is temporarily stopped, it is inefficient.

  The kneader 3 repeats the following operations (1) to (4). (1) The material is supplied to the kneading chamber 32 in which the door portion 33 is closed. (2) The material is kneaded in the kneading chamber 32 to produce a kneaded material M (FIG. 2). (3) The door 33 is opened and the kneaded material M in the kneading chamber 32 is sent to the next process (FIG. 3). (4) Close the door 33.

  If the wear inspection is performed during the period when the door 33 is opened and the kneaded material M is taken out from the kneading chamber 32, the operation of the kneading machine 3 does not have to be stopped, so that the efficiency is high.

  However, when the door portion 33 is opened, the distal end portion 53 of the protective tube 51 is exposed to a normal temperature environment, so that the temperature measured by the temperature measuring device 6 is rapidly reduced.

  Therefore, in order to know the amount of temperature rise measured by the temperature measuring device 6 by supplying current to the thermocouple wire 52 in a state where the door portion 33 is opened, the door portion 33 is opened, The effect of a sudden drop in temperature must be eliminated.

  The temperature measured by the temperature measuring device 6 when the current is supplied to the thermocouple wire 52 in a state where the door portion 33 is opened is set as the actual temperature. When it is assumed that no current is supplied to the thermocouple wire 52 in a state where the door portion 33 is opened, the temperature estimated by the temperature measurement device 6 is taken as the estimated temperature. The amount of increase in temperature measured by the temperature measuring device 6 due to the fact that the temperature measuring contact 52c generates heat by supplying current to the thermocouple wire 52 is defined as the temperature increase amount. If the estimated temperature is subtracted from the actual temperature, the above influence can be eliminated. That is, the value obtained by subtracting the estimated temperature from the actual temperature is the temperature rise amount.

  The estimated temperature can be obtained using the exponential function equation shown in Equation 1. Formula 1 is a general formula that represents a temperature drop.

y = a * exp (b * x) (Formula 1)
Here, “y” indicates temperature, “x” indicates elapsed time, and “a” and “b” are coefficients. Among these, “b” indicates how the temperature decreases, that is, whether the temperature decreases rapidly or gradually. An approximate expression calculation unit 86 (FIG. 6), which will be described later, uses Expression 1 to calculate an approximate expression (that is, an expression for obtaining an estimated temperature).

  Next, the thermocouple inspection device 8 will be described. FIG. 6 is a block diagram showing a configuration of the thermocouple inspection apparatus 8 according to the present embodiment.

  The thermocouple inspection device 8 performs a wear inspection using the temperature measured by the temperature measurement device 6 shown in FIG.

  As shown in FIGS. 2 and 3, the temperature measuring device 6 uses the protective tube type thermocouple 5 to measure the temperature of the kneaded material M generated in the kneading chamber 32 and the door 33 is opened. In the state where the plating layer 55 is not in contact with the kneaded material M, the temperature around the plating layer 55 is measured.

  The thermocouple inspection device 8 includes a door opening / closing determination unit 81, a power supply unit 82, a switch unit 83, a current supply control unit 84, a period elapsed determination unit 85, an approximate expression calculation unit 86, a subtraction unit 87, a wear determination unit 88, and A notification unit 89 is provided.

  The door opening / closing determination unit 81 determines whether the door unit 33 is opened or the door unit 33 is closed based on a signal output from a sensor (not shown). The sensor outputs different signals depending on whether the door portion 33 is opened or not.

  The power supply unit 82 generates a current to be supplied to the thermocouple strand 52.

  The switch unit 83 is configured by a transistor, for example. When the switch unit 83 is on, the current generated by the power supply unit 82 is supplied to the external wiring 57b. When the switch unit 83 is off, the current generated by the power supply unit 82 is not supplied to the external wiring 57b.

  The current supply control unit 84 performs on / off control of the switch unit 83. More specifically, the current supply control unit 84 switches the switch unit 83 from OFF to ON when the door unit 33 is opened in order to take out the kneaded material M from the kneading chamber 32, and sets the first period in advance. When elapses, the switch unit 83 is switched from on to off. Thereby, in order to take out the kneaded material M from the kneading chamber 32, the kneading machine 3 operates to open the door portion 33, so that the thermocouple wire 52 is opened in the first period while the door portion 33 is opened. And the supply of current to the thermocouple wire 52 is stopped after the elapse of the first period.

  The period elapsed determination unit 85 determines whether or not a predetermined second period has elapsed with the door 33 being opened after the first period has elapsed. FIG. 7 is a time chart showing a period of wear inspection. The period T0 for wear inspection is divided into a first period T1, a second period T2, and a sampling period T3. When the wear inspection period T0 is, for example, 4 seconds, the first period T1 is, for example, 1 second, the second period T2 is, for example, 2 seconds, and the sampling period T3 is, for example, 1 Seconds.

  By supplying a current to the thermocouple wire 52 in the first period T1, the temperature measuring contact 52c (FIG. 4) generates heat. A period in which this influence remains is a second period T2, and a period in which the influence does not remain is a sampling period T3. The sampling period T3 will be described in the following approximate expression calculation unit 86.

  The approximate expression calculation unit 86 calculates an expression for obtaining the estimated temperature using the exponential function expression shown in Expression 1 described above. That is, if no current is supplied to the thermocouple element 52 in the first period T1, an approximate expression indicating the temperature estimated to be measured by the temperature measuring device 6 in the second period T2 is calculated. In other words, if no current is supplied to the thermocouple element 52 in the first period T1, the temperature is measured when the temperature is measured using the protective tube thermocouple 5 in the second period T2. An approximate expression indicating the estimated temperature is calculated.

  The approximate expression calculation unit 86 is an example of an expression calculation unit. The temperature calculating device 6 measures the temperature measured by the temperature measuring device 6 after the elapse of the first period T1 when the door 33 is opened and the protective tube type thermocouple 5 is exposed to the atmosphere outside the kneading chamber 32. An equation for estimating the decrease in the is calculated.

  The approximate expression is calculated after the second period T <b> 2 is determined by the period elapsed determination unit 85 out of the temperatures measured by the temperature measuring device 6 with the door 33 opened (the sampling period). The temperature measured in T3) is used. This is because the sampling period T3 is defined as a period in which the influence of heat generated by the temperature measuring contact 52c does not remain because the current is supplied to the thermocouple element 52 in the first period T1.

  As described above, the approximate expression is presumed that the temperature measurement device 6 measured in the second period T2 when no current was supplied to the thermocouple wire 52 in the first period T1. It is a formula which shows temperature (estimated temperature). This is because if the approximate expression is calculated using the temperature measured during the period during which the temperature measuring contact 52c is affected by heat generation (that is, the second period T2), the approximate expression does not indicate an accurate estimated temperature. is there.

  The approximate expression calculation unit 86 acquires temperature data measured by the temperature measuring device 6 at predetermined intervals in the sampling period T3.

  The subtraction unit 87 calculates a subtraction value obtained by subtracting the temperature indicated by the approximate expression calculated by the approximate expression calculation unit 86 from the temperature measured by the temperature measurement device 6 in the second period T2. When the approximate equation calculation unit 86 is the above equation calculation unit, the subtraction unit 87 subtracts the temperature indicated by the equation calculated by the equation calculation unit from the temperature measured by the temperature measurement device 6 after the elapse of the first period T1. Calculate the subtraction value.

  The wear determining unit 88 determines whether the plated layer 55 is worn by using the fact that the subtracted value is larger when the plated layer 55 is worn than when the plated layer 55 is not worn.

  The notification unit 89 is a display, for example, and notifies the result determined by the wear determination unit 88.

  Next, the operation of the thermocouple inspection apparatus 8 according to this embodiment will be described. FIG. 8 is a flowchart for explaining the operation.

  When the generation control unit 37 of the kneading machine 3 shown in FIG. 3 determines that the generation of the kneaded product M is completed, the door control unit 38 opens the door unit 33 in order to take out the kneaded product M from the kneading chamber 32. Take control. Thereby, the door opening / closing judgment part 81 shown in FIG. 6 judges that the door part 33 was opened (step S1).

  Since the door opening / closing determination unit 81 determines that the door unit 33 has been opened, the current supply control unit 84 supplies a current to the thermocouple wire 52 (step S3). More specifically, the current supply control unit 84 illustrated in FIG. 6 switches the switch unit 83 from off to on, and then switches the switch unit 83 from on to off after the first period T1 (FIG. 7) has elapsed. As a result, current is supplied to the thermocouple element 52 in the first period T1, and the temperature measuring contact 52c (FIG. 4) generates heat.

  The period elapsed determination unit 85 determines whether or not the second period T2 (FIG. 7) has elapsed with the door 33 opened after the first period T1 has elapsed (step S5). . The door opening / closing determining unit 81 determines whether the door 33 is opened.

  If the period elapsed determination unit 85 determines that the second period T2 has not elapsed (No in step S5), the process of step S5 is repeated.

  When the period elapsed determination unit 85 determines that the second period T2 has elapsed (Yes in step S5), the approximate expression calculation unit 86 calculates an approximate expression (step S7). This will be described in detail.

  FIG. 9 is a graph showing the temperature measured by the temperature measuring device 6 in the second period T2 and the sampling period T3, that is, a graph showing the actual temperature. FIG. 10 is a graph showing the approximate expression calculated by the approximate expression calculation unit 86 in the second period T2 and the sampling period T3, that is, a graph indicating the estimated temperature. FIG. 11 is a graph obtained by superimposing the graph of FIG. 9 and the graph of FIG. 9 to 11, the horizontal axis represents time (seconds), and the vertical axis represents the temperature (° C.) measured by the temperature measuring device 6. On the horizontal axis, the period from 0.00 second to 2.00 seconds is the second period T2, and the period from 2.00 seconds to 3.00 seconds is the sampling period T3.

  Referring to FIG. 9, at 0.00 seconds (that is, immediately after the first period T1 elapses), the supply of current to the thermocouple element 52 is stopped, and the temperature measurement contact 52c (FIG. 4) generates heat. Stops. For this reason, in 0.00 second, the temperature measured by the temperature measuring device 6 is rapidly decreased.

  After that, the temperature measured by the temperature measuring device 6 decreases. This is because the protective tube type thermocouple 5 is exposed to a room temperature environment because the door 33 of the kneading chamber 32 is opened as shown in FIG.

  The approximate expression calculation unit 86 acquires temperature data measured by the temperature measurement device 6 every 10 μs, for example, in the sampling period T3. If the sampling period T3 is 1 second, 100 pieces of temperature data are acquired.

  The approximate expression calculation unit 86 calculates an approximate expression using the acquired temperature data and the exponential function expression shown in Expression 1. The approximate expression is, for example, as follows.

y = 127.74e− ^0.0206x (Expression 2)
FIG. 10 is a graph showing Equation 2. As described above, this graph is a graph showing the estimated temperature.

  The subtraction unit 87 calculates a subtraction value obtained by subtracting the temperature indicated by the approximate expression calculated by the approximate expression calculation unit 86 from the temperatures measured by the temperature measuring device 6 during the second period T2 and the sample period T3 (step S9). . The subtraction value is a value obtained by subtracting the estimated temperature from the actual temperature, and indicates a temperature rise amount. The amount of temperature increase is the amount of temperature increase measured by the temperature measuring device 6 because the temperature measuring contact 52c generates heat during the first period T1.

  More specifically, as shown in FIG. 12, the subtraction unit 87 calculates a graph indicating a value obtained by subtracting a value indicated by the graph of FIG. 10 from a value indicated by the graph of FIG. In FIG. 12, the horizontal axis indicates time (seconds). The vertical axis represents the temperature rise (° C.).

  As described above, the graph shown in FIG. 9 is measured by the temperature measuring device 6 in the second period T2 and the sampling period T3 when current is supplied to the thermocouple wire 52 in the first period T1. It is a graph which shows the measured temperature (actual temperature). On the other hand, the graph shown in FIG. 10 shows the temperature measuring device in the second period T2 and the sampling period T3 when no current is supplied to the thermocouple wire 52 in the first period T1. 6 is a graph showing the temperature (estimated temperature) estimated to be measured.

  In the second period T2, the temperature rise amount is greater than zero. This is because the influence of heat generated by the temperature measuring contact 52c remains in the second period T2 because the current is supplied to the thermocouple wire 52 in the first period T1. In the sampling period T3, the temperature rise amount is substantially zero. This is because the influence does not remain in the sampling period T3.

  The wear determination unit 88 determines whether the plating layer 55 is worn using the temperature rise amount (subtraction value) in the second period T2 shown in FIG. 12 (step S11). There are several methods for determining whether the plated layer 55 is worn. For example, if the temperature increase amount at a predetermined time (for example, 0.50 seconds) during the second period T2 exceeds a predetermined threshold value, the plating layer 55 is worn. If it does not exceed, it is determined that the plating layer 55 is not worn.

  If the slope of the graph shown in FIG. 12 exceeds a predetermined threshold at a predetermined time during the second period T2, it is determined that the plating layer 55 is worn, If not, it is determined that the plating layer 55 is not worn.

  In the second period T2 shown in FIG. 12, these methods may be applied after the process of moving average the graph of FIG. This is because the error can be reduced because the graph of FIG.

  When the wear determination unit 88 determines that the plating layer 55 is worn (Yes in step S11), the notification unit 89 displays a warning to replace the protective tube thermocouple 5 (step S13).

  When the wear determination unit 88 determines that the plated layer 55 is not worn (No in step S11), the door control unit 38 of the kneader 3 shown in FIG. 1 performs control to close the door 33 (step S15). ). And the production | generation control part 37 controls the production | generation of the following kneaded material M in the kneading | mixing chamber 32, after the door part 33 is closed.

  Although the example in which the wear inspection is executed only once by opening and closing the door portion 33 once has been described, the wear inspection may be executed a plurality of times by opening and closing the door portion 33 once. If the first period T1 is 1.0 second, the second period T2 is 2.0 seconds, the sampling period T3 is 1.0 second, and the door 33 is opened for 15 seconds, the wear inspection is performed. Is executed three times. When the wear determination unit determines that the plating layer 55 is worn even once in the three wear inspections, the notification unit 89 displays a warning to replace the protective tube type thermocouple 5.

  The wear inspection may be performed every time the door portion 33 is opened and closed, or the wear inspection may be performed every time a predetermined period elapses (for example, once a day).

  The main effects of this embodiment will be described. In the present embodiment, referring to FIG. 4, when the plating layer 55 (contact point) is worn, when the current is supplied to the thermocouple wire 52, compared to the case where the plating layer 55 is not worn. In addition, the wear of the plating layer 55 is determined using the fact that the amount of temperature increase measured by the temperature measuring device 6 increases.

  Referring to FIG. 3, when the wear inspection of the plating layer 55 is performed in a state where the door portion 33 of the kneading chamber 32 is opened, the temperature measured by the temperature measuring device 6 is increased by opening the door portion 33. The effect of a sudden drop must be eliminated.

  When current is supplied to the thermocouple wire 52 with the door 33 opened, the temperature measured by the temperature measuring device 6 is set as the actual temperature (FIG. 9). When it is assumed that no current is supplied to the thermocouple wire 52 in a state where the door portion 33 is opened, the temperature estimated by the temperature measurement device 6 is taken as the estimated temperature. In the present embodiment, the temperature indicated by the approximate expression calculated by the approximate expression calculation unit 86 is the estimated temperature (FIG. 10). The amount of increase in temperature measured by the temperature measuring device 6 due to the fact that the temperature measuring contact 52c generates heat by supplying current to the thermocouple wire 52 is defined as the temperature increase amount.

  If the estimated temperature is subtracted from the actual temperature, the above influence can be eliminated. That is, the value obtained by subtracting the estimated temperature from the actual temperature is the temperature increase amount (FIG. 12).

  As described above, according to the present embodiment, the tubular member (protective tube 51) provided in the thermocouple (protective tube type thermocouple 5) used for measuring the temperature of the kneaded material M and containing the thermocouple strand 52. , It can be inspected whether the portion (plating layer 55) in contact with the kneaded material M is worn.

  Further, according to the present embodiment, as described with reference to the flowchart of FIG. 8, wear inspection is performed when the door portion 33 is opened in order to take out the kneaded material M from the kneading chamber 32. Therefore, wear inspection can be performed during the operation of the kneader 3. When the kneading machine 3 is in operation, the kneaded material M is generated in the kneading chamber 32, the door 33 is opened to take out the kneaded material M, the door 33 is closed, and the next kneaded material M is generated in the kneading chamber 32. It is to repeat the process. Therefore, according to the present embodiment, it is not necessary to stop the operation of the kneader 3 in order to perform the wear inspection.

  There is a correlation between the thickness of the plating layer 55 (FIG. 4) and the temperature increase amount, so that the temperature increase amount increases as the thickness of the plating layer 55 decreases. According to the present embodiment, the wear amount (worn thickness) of the plated layer 55 can be predicted, so that the plated layer 55 disappears due to wear and before the protective tube 51 is damaged, the protective tube type thermoelectric device is obtained at an appropriate timing. It is possible to notify that the pair 5 is exchanged.

  Referring to FIG. 4, if the thickness of the protective tube 51 is reduced, the heat capacity of the protective tube 51 is reduced, so that the protective tube type thermocouple 5 having excellent responsiveness is obtained. However, when the thickness of the protective tube 51 is small, if the plated layer 55 is peeled off due to wear, the protective tube 51 is immediately damaged. In the present embodiment, since the wear amount of the plated layer 55 can be predicted, the protective tube 51 having a small thickness can be used.

  In the case of the protective tube 51 having a small wall thickness, the heat capacity of the protective tube 51 is small, so that when the wear inspection is performed, the temperature increase amount becomes large. Therefore, it can be determined more accurately whether or not the plating layer 55 is worn.

  In the present embodiment, the example in which the plating layer 55 covering the distal end portion 53 of the protective tube 51 is a contact portion has been described. However, when the distal end portion 53 of the protective tube 51 is not covered with the plated layer 55, that is, the plating layer The present invention can also be applied to the tip portion 53 that does not include 55.

3 Kneading Machine 5 Protective Tube Thermocouple 6 Temperature Measuring Device 8 Thermocouple Inspection Device 32 Kneading Chamber 33 Door 51 Protective Tube 52 Thermocouple Wire 52c Temperature Measuring Contact 55 Plating Layer (Example of Contact Location)
53 Tip 86 Approximation Formula Calculation Unit (Example of Formula Calculation Unit)
M Kneaded material T0 Wear inspection period T1 First period T2 Second period T3 Sampling period

Claims (5)

A kneading machine comprising: a kneading chamber; and a door portion that is opened when taking out the kneaded material from the kneading chamber;
Utilizing a thermocouple including a tubular member having a contact point that is a contact point with the kneaded material, and a thermocouple element housed in the tubular member, the kneaded material generated in the kneading chamber A temperature measuring device for measuring the temperature;
A thermocouple inspection device applied to a system comprising:
Supplying current to the thermocouple element in a predetermined first period with the door portion opened, and supplying current to the thermocouple element after the elapse of the first period A current supply control unit for stopping
An equation calculation unit for calculating an equation for estimating a decrease in temperature measured by the temperature measurement device after the first period;
A subtraction unit that calculates a subtraction value obtained by subtracting the temperature indicated by the equation calculated by the equation calculation unit from the temperature measured by the temperature measurement device after the elapse of the first period;
Based on the subtraction value, a wear determination unit that determines whether the contact portion is worn;
A thermocouple inspection device comprising: an informing unit for informing a result determined by the wear determining unit. A period elapse determination unit for determining whether a predetermined second period elapses after the first period elapses;
The thermocouple inspection device according to claim 1, wherein the equation calculation unit calculates the equation using a temperature measured by the temperature measurement device during a predetermined sampling period after the second period has elapsed. .   The thermocouple inspection device according to claim 1, wherein the contact portion includes a plating layer. A kneading machine comprising: a kneading chamber; and a door portion that is opened when taking out the kneaded material from the kneading chamber;
Utilizing a thermocouple including a tubular member having a contact point that is a contact point with the kneaded material, and a thermocouple element housed in the tubular member, the kneaded material generated in the kneading chamber A temperature measuring device for measuring the temperature;
A thermocouple inspection method applied to a system comprising:
Supplying current to the thermocouple element in a predetermined first period with the door portion opened, and supplying current to the thermocouple element after the elapse of the first period A current supply control step for stopping the operation;
An equation calculating step for calculating an equation for estimating a decrease in temperature measured by the temperature measuring device after the elapse of the first period;
A subtraction step of calculating a subtraction value obtained by subtracting the temperature indicated by the equation calculated by the equation calculation step from the temperature measured by the temperature measuring device after the first period has elapsed;
Wear determination step for determining whether the contact portion is worn based on the subtraction value;
A thermocouple inspection method comprising: a notifying step for notifying a result determined by the wear determining unit. A thermocouple inspection device that inspects a thermocouple including a tubular member having a contact point that is a contact point with a kneaded product, and a thermocouple element housed in the tubular member,
A current supply control unit that supplies current to the thermocouple element in a predetermined first period and stops supplying current to the thermocouple element after the first period has elapsed; ,
A period elapsed determination unit that determines whether or not a predetermined second period has elapsed since the first period has elapsed;
Among the temperatures measured using the thermocouple, the first period using the temperature measured during the sampling period after the period elapsed determination unit determines that the second period has elapsed. If no current is supplied to the thermocouple wire, an approximate expression indicating the estimated temperature is calculated when the temperature is measured using the thermocouple in the second period. An approximate expression calculation unit;
A subtraction unit that calculates a subtraction value obtained by subtracting the temperature indicated by the approximate expression calculated by the approximate expression calculation unit from the temperature measured using the thermocouple in the second period;
Based on the subtraction value, a wear determination unit that determines whether the contact portion is worn;
An informing unit for informing the result determined by the wear determining unit;
Thermocouple inspection device comprising:

Images