JP2000263540A - Earth volume level control method for earth kneading machine vacuum chamber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an earth volume level control method for an earth kneading machine vacuum chamber for reducing the number of frequency of setting a primary shaft on and off and make the life of a bearing longer. SOLUTION: A laser projector 7 and a light receiving camera 8 are set above an earth kneading machine vacuum chamber 3, and a plane laser beams 10 are projected on the whole width of the vacuum chamber 3 on the upper face of a secondary shaft 4 to detect the average earth volume level of a specified section in the vacuum chamber. When the detected average earth volume level is high, the number of revolutions of the primary shaft 1 is decreased, while when the average earth volume level is low, the number of revolutions of the primary shaft 1 is so controlled as to be increased. The number of frequency of setting the primary shaft 1 on and off can be reduced to a large extent by the arrangement.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a soil volume level in a vacuum chamber of a clay kneading machine for vacuum degassing ceramic material and extruding it as clay.

[0002]

2. Description of the Related Art In a ceramic product manufacturing plant, a slurry-like raw material is formed into a dewatered cake by a filter press, then put into a clay kneading machine and extruded as kneaded clay, and the kneaded clay is processed into various ceramic products. There are many. This clay kneading machine is a device in which soil is extruded into a vacuum chamber by a primary shaft provided with screw blades, deaerated in the vacuum chamber, and extruded as clay from an outlet by a secondary shaft penetrating the vacuum chamber.

[0003] The primary shaft and the secondary shaft are rotated at a constant speed. However, it is difficult to keep the hardness of the dewatered cake supplied to the clay kneader constant. When the extrusion amount by the secondary shaft increases, and when the hardness is high, it is inevitable that the extrusion amount by the secondary shaft decreases. For this reason, the soil volume level in the vacuum chamber fluctuates during operation, and when the soil volume level is significantly reduced, there is a problem that the extruded clay is interrupted, and when the soil volume level continues to increase, the vacuum chamber is clogged. Caused a problem that production became impossible.

[0004] Therefore, conventionally, a light emitting and receiving device is mounted above the vacuum chamber, and when the earth volume level decreases and the secondary shaft is exposed, reflected light is detected to drive the primary shaft to drive the secondary shaft. When is not visible, on / off control is performed to stop the primary axis after a lapse of time set by the timer.
However, this conventional method has the following three problems.

First, a large thrust load acts on the primary shaft. When the above-mentioned on / off control is performed, an impact load is applied to the bearing, especially at the time of starting. For this reason, in the conventional method in which the bearing is frequently turned on and off, the life of the bearing of the primary shaft is short, and it is necessary to stop the machine and replace the bearing. Second, the above-described control method can only detect that the secondary shaft has been exposed due to a decrease in the volume level of the vacuum chamber, and therefore cannot be detected when the volume level of the vacuum chamber has increased. Met. Third, the emitter / receiver monitors only on the axis of the secondary shaft, but in reality, the soil rotates in the vacuum chamber with the rotation of the secondary axis, and the soil volume level in the vacuum chamber depends on each position. And the surface shape of the soil is complicated. For this reason, it was not possible to accurately grasp the soil volume level only by monitoring on the secondary shaft.

[0006]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, reduces the frequency of turning on and off the primary shaft, and can detect not only when the soil volume level has decreased but also when it has increased. The purpose of the present invention is to provide a method for controlling a soil volume level of a vacuum chamber of a clay kneading machine capable of accurately grasping the soil volume level of the entire vacuum chamber.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a laser projector and a light-receiving camera set above a vacuum chamber of a clay kneading machine. When the average soil level is high, the primary shaft that supplies soil to the vacuum chamber is reduced when the average soil volume level is high, and the primary shaft is rotated so that the primary shaft speed is increased when the average soil volume level is low. It is characterized by controlling. It is preferable that the laser projector emits a flat laser beam over the entire width of the vacuum chamber on the upper surface of the secondary axis, and the flat laser beam is directed perpendicularly to the secondary axis passing through the vacuum chamber. It is preferable that the light is projected.

According to the present invention, the frequency of the primary shaft can be reduced because the earth volume level of the vacuum chamber is controlled by changing the rotation speed of the primary shaft. In addition, since the average volume level of a specific cross section of the vacuum chamber is detected by projecting a flat laser beam over the entire width of the vacuum chamber on the upper surface of the secondary shaft, the volume level rises as well as when the volume level decreases. Can be detected, and the soil volume level of the entire vacuum chamber can be accurately grasped.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below. FIG. 1 is an overall view of a kneading machine, where 1 is a primary shaft, 2
Is a primary shaft drive for rotating the primary shaft, 3 is a vacuum chamber, 4
Is a secondary shaft provided at the lower part through the vacuum chamber 3, and 5 is an extrusion drum. As in the conventional case, the cake is extruded into the vacuum chamber 3 from the upper part of the vacuum chamber 3 by the primary shaft 1 into a thin streak, and after being degassed by vacuum, is extruded by the secondary shaft 4 from the extrusion outlet 5, for example, a columnar clay. Extruded as

The ceiling plate of the vacuum chamber 3 is a transparent resin plate 6,
Above it, a laser projector 7 and a light receiving camera 8 are set. As shown in FIG. 2, the laser projector 7 projects a planar laser beam 10 over the entire width of the vacuum chamber 3. In this embodiment, the laser projector 7 has a planar laser beam 10 in a direction perpendicular to the secondary shaft 4 penetrating the vacuum chamber 3. Is emitted. The light receiving camera 8 detects light reflected from the surface of the soil in the vacuum chamber 3 and calculates the soil level based on the amount of change in the position of the reflected light. At this time, the laser beam 10 is linearly projected on the upper surface of the secondary shaft 4 over the entire width of the vacuum chamber 3, and the light receiving camera 8 detects the soil volume level along this straight line. Therefore, the average value of the soil volume level of the entire vacuum chamber can be easily obtained.

When dew condensation occurs in the vacuum chamber 3, the transparent resin plate 6 becomes cloudy and the soil level cannot be detected.
It is desirable to heat the transparent resin plate 6 with a heater to prevent dew condensation. Further, when the laser beam 10 crosses the soil that is falling into the vacuum chamber 3 by the primary shaft 1, noise is included in the detected value. Therefore, it is preferable that the laser beam 10 does not detect the falling soil.

As shown in FIG. 3, in this embodiment, 100 mm, 200 m
Three setting values of m and 300 mm are set. When the detected average soil volume level is higher than 300 mm, the rotation of the primary shaft 1 that supplies the soil to the vacuum chamber 3 is stopped, but the rotation speed of the primary shaft 1 is set to 5 rpm within the range of 200 to 300 mm. , Within a range of 100 to 200 mm, the rotation speed of the primary shaft 1 is set to 5.5 rpm, and 100 m
m, the rotation of the primary shaft 1 is controlled so as to increase the rotation speed of the primary shaft 1 according to the average soil volume level, such as 6 rpm. Of course, the set value and the rotation speed of the primary shaft 1 can be arbitrarily changed, and the rotation speed of the primary shaft 1 can be changed steplessly according to the change in the average soil volume level.

As described above, in the present invention, the average soil volume level of a specific section in the vacuum chamber 3 is detected, and the rotation speed of the primary shaft 1 is changed according to the average soil volume level. The frequency at which the primary shaft 1 is turned on and off is reduced.
Specifically, according to the results of the applicant company, the number of stops of the primary shaft 1 was conventionally about 20 times per hour in the past,
According to the present invention, it is possible to reduce the frequency to four times an hour, and the stop frequency is reduced to 1/5. For this reason, the life of the bearing of the primary shaft 1 could be greatly extended.

Further, in the present invention, since the volume level in the vacuum chamber 3 can always be detected by using the laser beam 10, the volume level decreases only when the secondary axis is exposed as the volume level decreases as in the prior art. Finer control is possible than a method of detecting shortage. In addition, since the average soil volume level of a specific section in the vacuum chamber is detected, it is possible to accurately grasp the soil volume level of the entire vacuum chamber compared to the conventional method in which only one point on the secondary shaft is viewed. Can be. As a result, more stable production than before becomes possible.

[0015]

As described above, according to the method for controlling the soil volume level in the vacuum chamber of the kneading machine of the present invention, the frequency of turning on and off the primary shaft can be reduced, and the life of the bearing can be extended. There are many advantages such as detecting not only when the volume level has decreased but also when it has increased, and also accurately grasping the soil volume level of the entire vacuum chamber, contributing to stable production.

[Brief description of the drawings]

FIG. 1 is an overall view of a clay kneading machine.

FIG. 2 is a perspective view showing a projection direction of a laser beam.

FIG. 3 is an explanatory diagram of a setting level.

[Explanation of symbols]

1 primary axis, 2 primary axis motor, 3 vacuum chamber, 4 secondary axis, 5 extrusion outlet, 6 transparent resin plate, 7 laser projector, 8 light receiving camera, 10 laser beam,

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hisaya Kobayashi F-term in Nihon Insulator Co., Ltd. 2-56, Suda-cho, Mizuho-ku, Nagoya-shi, Aichi (reference) 4G056 AA03 BA04 BA19 DA05

Claims (3)

[Claims] 1. A laser projector and a light receiving camera are set above a vacuum chamber of a kneading machine to detect an average soil volume level of a specific section in the vacuum chamber. And controlling the rotation of the primary shaft so as to increase the rotation speed of the primary shaft when the average soil volume level is low. . 2. The method according to claim 1, wherein the laser projector emits a planar laser beam over the entire width of the vacuum chamber on the upper surface of the secondary shaft. 3. The method according to claim 2, wherein a planar laser beam is projected in a direction perpendicular to a secondary axis passing through the vacuum chamber.