JPH07213841A - Exhauster - Google Patents

Abstract

PURPOSE:To effectively use a filter and to properly detect its replacement time. CONSTITUTION:Gas in a device is introduced into an exhausting pipe 1 and passed through a filter 3 and discharged to outside of the device from a discharge port by a fan 2. Plural wind velocity detectors 4 are installed on the downstream side of a filter 3, and a CPU 7 is set so that the distribution of the clogging of the filter 3 and the degree of the clogging of the whole filter may be detected by their output. A movable blade 6 is installed on the upstream side of the filter 3, and based on the control of the CPU 7, a directional angle is determined so that much gas may be introduced into a part of the filter where clogging is low. When the whole region of the filter 3 is clogged, an indicator 8 indicates that the replacement time of the filter has come.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is provided in an apparatus such as a copying machine, exhausts gas in a housing of the apparatus to the outside of the apparatus, and collects dust contained in the gas on a filter. Regarding

[0002]

2. Description of the Related Art Generally, an exhaust device is provided in an apparatus such as a copying machine to discharge the gas inside the apparatus housing to the outside of the apparatus through an exhaust pipe, and at the same time, toner, paper dust or the like scattered in the exhaust. The dust is collected by the filter installed in the exhaust pipe. In such an exhaust device, if the filter collects a certain amount of dust and causes clogging, the gas in the housing cannot be efficiently discharged, and the dust in the housing cannot be efficiently removed. . Therefore, it is necessary to replace the filter when the filter collects a certain amount of toner and paper dust and causes clogging, and the exhaust device detects the clogging of the filter and displays the filter replacement time. Means are provided.

As an exhaust device provided with a means for detecting clogging of a filter, for example, Japanese Patent Publication No. 58-5610.
Like the device disclosed in Japanese Patent Publication No. 2), a branch pipe connecting the ventilation pipes before and after the filter is provided, and the pressure difference is detected by the position of the steel ball in the branch pipe to detect the clogging of the filter. And the device disclosed in Japanese Utility Model Laid-Open No. 4-98423, paying attention to the fact that when the filter is clogged, the load of the exhaust fan increases and the rotation speed decreases, and the change in the rotation speed is For example, there are those that detect and detect filter clogging.

[0004]

However, in many cases, the exhaust pipe line is bent, or the exhaust pipe line joins the pipe lines from the intake holes provided at a plurality of positions. In an exhaust device having such a pipeline, when dust or the like contained in the exhaust gas is collected by the filter, it should be biased toward a part of the filter provided over the entire cross section of the pipeline. There is. This is because the flow velocity in the pipeline is different due to the bend in the pipeline,
In the case of having the above, it occurs when the amount of dust in the exhaust gas discharged from each intake hole is significantly different. If the conventional technique is applied to such an exhaust pipe as it is, when it is determined that it is time to replace the filter, some parts of the filter are still in a usable state and other parts are in a usable state. It has been used past. Therefore, there is a problem that the replacement time of the filter is displayed earlier than necessary and the life of the filter is actually shortened.

The present invention has been made in view of the above problems, and an object thereof is to provide an exhaust device which can effectively use a filter and can appropriately detect the replacement time. .

[0006]

In order to solve the above-mentioned problems, the invention according to claim 1 provides an exhaust pipe for guiding the gas in the device housing to the outside of the device, and a fan for discharging the gas to the outside of the device. An exhaust device having a filter for collecting dust contained in exhaust gas, the exhaust device being provided in the exhaust pipe, and at a plurality of positions in an exhaust pipe cross section in the vicinity of the filter, a velocity of an air flow in the exhaust pipe is adjusted. It shall have a wind speed detector for detection.

According to a second aspect of the present invention, an exhaust pipe for guiding the gas in the device housing to the outside of the device, a fan for discharging the gas to the outside of the device, and a fan provided in the exhaust pipe for collecting dust contained in the exhaust gas. In the exhaust device having a filter for collecting, a plurality of pressure detectors are respectively provided so as to make a pair on the upstream side and the downstream side of the filter in the exhaust pipe.

The invention according to claim 3 is the above-mentioned claim 1.
Alternatively, in the exhaust system according to claim 2, a movable blade that is provided on the upstream side of the filter in the exhaust pipe and that controls an inflow region of gas that flows into the filter,
Based on the data detected by the plurality of wind speed detectors or pressure detectors, a calculating means for calculating the distribution of the dust collected in the filter in the exhaust pipe cross section,
And a control means for controlling the movable blade based on the dust distribution obtained by the calculation means.

The wind speed detector according to the first aspect of the present invention uses, for example, a thermistor, measures the temperature while supplying a predetermined amount of heat to the sensor portion, and detects the wind speed from the amount of heat dissipated in the exhaust gas. It can be a thing to do. The pressure detector in the invention according to claim 2 is
For example, it is possible to use an actuator having an actuating member whose position is changed by a change in atmospheric pressure and electrically detecting the displacement of the actuating member.

Further, in the invention as set forth in claim 2, it is desirable that the pressure detectors are provided on the upstream side and the downstream side of the filter in the vicinity of the filter, and the upstream side on a line parallel to the axis of the pipeline. It is desirable to use a pair of pressure detectors provided on each of the side and the downstream side.

In the invention described in claim 3, the movable blade is for controlling the flow of gas in the exhaust pipe so that a large amount of exhaust gas flows into a portion of the filter where the filter is not clogged. It may consist of a single wing body provided, or may consist of a plurality of wing bodies. Also,
The movable wing is supported so as to be able to change its direction, and is provided with drive means such as a solenoid which operates based on a signal input from the control means. In addition,
In addition to the above-mentioned solenoid, the drive means may be a drive motor equipped with a rack and a pinion to drive the blade body.

[0012]

According to the exhaust device of the first aspect, the gas in the device housing is sucked into the exhaust pipe from the suction port by the rotation of the fan, and is moved to the outside of the device after moving in the exhaust pipe. At this time, since a filter is provided in the exhaust pipe, when gas passes through the filter,
The dust contained in the gas is collected by the filter. At this time, even if the dust trapped in the filter is unevenly distributed in the exhaust pipe cross section and the degree of clogging may vary depending on the filter part, the ventilation device of the present invention has a plurality of wind speed detectors near the filter. Since it is equipped with, it is possible to detect the distribution of the degree of such clogging. That is, it is difficult for gas to pass in the part where the filter is clogged, and the wind speed is detected small by the wind speed detector, and the wind speed is detected large in the part where the filter is not clogged. Therefore, the distribution of the degree of clogging of the entire filter is detected, and it becomes possible to appropriately determine the time when the clogging is wholly covered and the filter needs to be replaced.

Further, in the exhaust device according to the second aspect, since the plurality of pressure detectors are provided so as to be paired on the upstream side and the downstream side of the filter, the pair of pressure detectors detect the pressure. The distribution of clogging of the filter can be known from the pressure difference that occurs. In other words, a small pressure difference is detected in a portion where there is little clogging and a large amount of exhaust gas passes, and a small amount of exhaust gas passes and a large pressure difference is detected in a portion where the degree of clogging is high. Therefore, the distribution of the degree of clogging of the entire filter is detected, and it becomes possible to appropriately determine the time when the clogging is wholly covered and the filter needs to be replaced.

In the exhaust device according to the third aspect of the present invention, the flow of exhaust gas in each section in the cross section of the exhaust pipe is detected by the wind speed detector or the pressure detector, and the distribution of clogging of the filter is obtained by the calculating means. Based on this distribution, the control means controls the direction of the movable blade so that the exhaust gas in the exhaust pipe is sent more to the region where the filter is less clogged.
As a result, a large amount of gas flows around the portion of the filter where the amount of collected dust is small, and the clogging of each portion of the filter is adjusted to be substantially uniform. Therefore, the clogging portion is prevented from being extremely biased, and the filter can be effectively used.

[0015]

Embodiments of the exhaust system of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an exhaust device which is an embodiment of the invention described in claim 1 or claim 3. FIG. 2 is a front view and a side view showing the outline of the entire shape of the exhaust device shown in FIG. This exhaust device is used in an electrophotographic image forming apparatus, and sucks gas inside the device from two intake ports 5 and 5 and discharges the gas to the outside of the device. An exhaust pipe connected to the two intake ports. 1 merges on the way and is guided to the exhaust port 10. A fan 2 for forcibly exhausting air is provided near the exhaust port 10, and a filter 3 is provided upstream of the fan 2. The filter 3 is for collecting toner and paper dust contained in the exhaust gas.

As shown in FIG. 1, on the downstream side of the filter 3, a plurality of wind speed detectors 4 are provided in the cross section of the exhaust pipe 1, and the data obtained by these wind speed detectors 4 are C
It is designed to be input to PU7. Wind speed detector 4
Is a device that supplies a constant amount of heat to the sensor part and measures the temperature. Since the amount of heat dissipated in the gas changes depending on the wind speed, the wind speed can be detected.

On the upstream side of the filter 3, a plurality of movable blades 6 are arranged side by side within the cross section of the exhaust pipe. This movable wing 6
Is composed of a blade body 6a that controls the flow of gas in the exhaust pipe and a support portion 6b that rotatably supports the blade body, and the drive device 11 can adjust the angle of the blade body. ing. The driving device 11 is controlled by a signal from the CPU 7, and the CPU 7 together with the RAM 9
It has a function as a calculation means for calculating the distribution of clogging of the filter 3 based on the data from the wind speed detector, and a function as a control means for controlling the movable blades based on the result of the calculation means. It is set. The display device 8 displays information necessary for the operator based on the signal output from the CPU 7, and can display, for example, that it is time to replace the filter 3.

Next, the operation of the exhaust device having the above structure will be described. In the above exhaust device, when the fan 2 is rotated, the gas in the image forming device is sucked into the two intake ports 5 and 5, merged in the exhaust pipe 1, and then passed through the filter 3 to be discharged to the outside of the device. . At this time, dust such as toner and paper dust contained in the exhaust gas is collected by the filter 3. In this way, when the air is sucked from the two intake ports 5 and 5 and discharged through the single filter 3, the dust contained in the exhaust gas sucked from one of the intake ports is compared with the exhaust gas from the other intake port. If the amount of dust is extremely large, the dust collected by the filter 3 may not be uniform in the cross section of the exhaust pipe, and the distribution of clogging of the filter 3 may be significantly uneven. With respect to such uneven distribution of clogging of the filter 3, the exhaust device of the present embodiment operates as in the flow shown in FIG.

That is, after the initial value is set in the CPU 7 (ST1, ST2), the data output from the thermistor of the wind speed detector 4 is input to the CPU 7 (ST3) and stored in the RAM 9 (ST4). ). This operation is repeated three times (ST5), three data are sequentially collected, and the average value thereof is calculated (ST6). Further, the output of the thermistor and the calculation of the average value are performed for each of the plurality of wind speed detectors (ST7). The distribution of clogging of the filter 3 in the exhaust pipe is determined as follows based on the temperature data thus obtained. That is, in the region where the temperature of the sensor portion of the wind speed detector 4 is measured high, the wind speed is small and the amount of heat dissipated to the exhaust is small, and in the region where the temperature is measured low, the wind speed is large and the heat to the exhaust is It is judged that there are many dissipations. Therefore, the filter 3 is clogged in the portion where the temperature is detected high, and the ventilation amount is small, while the degree of clogging is low in the portion where the temperature is detected low, and a sufficient ventilation amount is secured. .

Further, the direction of the movable blade 6 is controlled based on the measurement value obtained as described above (ST8). The control of the movable blade is performed as shown in FIG.
First, the CPU 7 selects a region having a small measurement value (ST21), and detects a region where the filter 3 is less likely to be clogged. The direction angle of blade 6a is calculated so that a large amount of exhaust gas flows in this region (ST22), and a drive signal is output to drive device 11 so that blade 6a is in that direction (ST23). The drive device 11 operates based on this drive signal, and the direction of the wing body 6a is adjusted. By performing such an operation at regular time intervals, the distribution of dust collected by the filter 3 is maintained substantially uniform, and the filter can be effectively used.

On the other hand, whether or not it is time to replace the filter is detected as follows. The total sum of the measurement data detected by the plurality of wind speed detectors is calculated (ST9), and the total sum is compared with a preset reference value (ST10). These measurement data are measured as temperature, and if the total sum of these measured values is large, it means that the wind speed at each position in the exhaust gas is decreased and the amount of exhaust gas passing through the filter 3 is decreased. means.
Therefore, by setting the total value of the temperatures measured when the filter 3 is clogged and must be replaced as a reference value, and comparing this with the measurement value from the wind speed detector, the filter 3 It is possible to detect the replacement time. In this way, when the total sum of the measurement data exceeds the reference value, a signal is output to the display device 8 and "filter replacement" is displayed.

FIG. 4 is a schematic configuration diagram showing a main part of an exhaust system which is an embodiment of the invention described in claim 2 or claim 3. In this exhaust device, a plurality of pressure detectors 24 are provided in the exhaust pipe 21 in place of the wind speed detector 4 used in the exhaust device shown in FIGS. 1 and 2. Further, the pressure detector 24 is provided not only on the downstream side of the filter 23 but also on the upstream side of the filter 23 with the same number of pressure detectors.
The filter 23 is arranged on a line parallel to the axis of the exhaust pipe 21.
The pressure detector provided on the upstream side and the pressure detector provided on the downstream side are installed so as to face each other. These pressure detectors 24 are capable of measuring the pressure at respective positions inside the exhaust pipe 21, and input the detected data to the CPU 27.

The CPU 27 is set to perform a necessary calculation based on the measurement data input from the pressure detector 24, and constitutes a calculation means for calculating the distribution of the dust collected by the filter together with the RAM 29. is doing. The exhaust pipe 2 used in the exhaust device of this embodiment
1, the fan 22, the filter 23, the movable blade 26, the display device 28, and the drive device 31 are the same as those used in the exhaust device shown in FIG.

In the exhaust system as described above, as in the exhaust system shown in FIGS. 1 and 2, the rotation of the fan 22 causes the gas in the system to be exhausted from the intake port through the exhaust pipe 21 so that the gas is exhausted. The contained dust is collected by the filter 23. Then, with respect to the uneven distribution of the dust collected by the filter 23, it operates as in the flow shown in FIG. C
After the initial value is set in PU (ST3
1, ST32), the data output from the pressure detector 24 is input to the CPU 27 (ST33) and stored in the RAM 29 (ST34). This operation is repeated 3 times for each pressure detector (ST35), and sequentially 3 times.
One data is collected. For these data, the average of three measurement values for each pressure detector is calculated (ST36, ST37). From the data thus obtained, the pressure difference between the installation positions of the pressure detectors facing each other is calculated (ST51), and the distribution of the clogging of the filter 23 in the exhaust pipe 21 is judged from the distribution of this pressure difference. . That is, when the pressure difference between the front and rear of the filter 23 is large, the amount of ventilation of the filter 23 is small in that portion, and when the pressure difference is small, the amount of exhaust gas passing through the filter 23 is large in that portion. I know that Therefore, the clogging of the filter 23 is progressing in the portion where the pressure difference is detected large, and the ventilation is sufficiently secured in the portion where the pressure difference is detected small, and it is determined that the degree of the clogging is low. .

Further, based on the measured values obtained as described above, a region where the filter 23 is less clogged is detected (ST52), and the directional angle of the blade is calculated so that a large amount of exhaust gas flows in this region. Then, the drive signal is output to the drive device 31 so that the wing body is oriented in that direction (ST53) (ST54). The drive device 31 operates based on this drive signal, and the direction of the wing body is adjusted. By performing such an operation at regular time intervals, the filter 23
The distribution of the dust collected in is kept substantially uniform, and the filter 23 can be effectively used.

Further, the total sum is calculated from the data of the pressure difference detected by the plurality of pressure detectors 24 facing each other as described above (ST38), and the total sum is compared with the preset reference value. (ST39). When the total sum of the pressure differences is large, it means that the amount of exhaust gas passing through the filter at each position in the exhaust gas is reduced, and when it is determined that the preset reference value is exceeded, the display device 28 A signal is output to and "Replace filter" is displayed.

[0027]

As described above, in the exhaust system according to the first aspect, since the plurality of wind speed detectors are provided near the filter, the distribution of the dust collected in the filter in the cross section of the exhaust pipe is Even if the bias and the degree of clogging vary depending on the filter part, the distribution of the degree of clogging can be detected, and the filter replacement time is not displayed earlier than necessary. It is possible to properly judge the time when the filter has to be replaced due to the entire clogging.

Further, in the exhaust device according to the second aspect, since a plurality of pressure detectors are provided so as to form a pair on the upstream side and the downstream side near the filter, the pressure detectors forming the pair detect the pressure. The distribution of clogging of the filter can be known from the pressure difference. Therefore, it is possible to appropriately judge the time when the filter is to be replaced truly, without displaying the replacement time of the filter earlier than necessary.

Further, in the exhaust system according to claim 3,
Since it has a movable blade that can control the flow of exhaust gas on the upstream side of the filter, it controls the flow in the exhaust pipe so that the exhaust gas is sent to many parts of the filter where the dust collection amount is small, It can be adjusted so that the clogging of each part of the filter is almost uniform. Therefore, clogging can be prevented from being biased to a part of the filter, and the life of the filter can be avoided from being shortened and the filter can be effectively used.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an exhaust device that is an embodiment of the invention described in claim 1 or claim 3. FIG.

2A and 2B are a front view and a side view schematically showing the overall shape of the exhaust device shown in FIG.

FIG. 3 is a flowchart showing an outline of operation of the exhaust device shown in FIG.

FIG. 4 is a schematic configuration diagram showing an exhaust device which is an embodiment of the invention described in claim 2 or claim 3.

FIG. 5 is a flowchart showing an outline of operation of the exhaust device shown in FIG.

[Explanation of symbols]

1, 21 Exhaust pipe 2, 22 Fan 3, 23 Filter 4 Wind speed detector 5 Inlet port 6, 26 Movable blade 7, 27 CPU 8, 28 Display device 9, 29 RAM 10 Exhaust port 11, 31 Drive device 24
Pressure detector

Claims (3)

[Claims] 1. An exhaust pipe for guiding the gas in the device housing to the outside of the device, a fan for discharging the gas to the outside of the device, and a filter provided in the exhaust pipe for collecting dust contained in the exhaust gas. An exhaust system having the exhaust system, wherein wind speed detectors for detecting a velocity of an air flow in the exhaust pipe are provided at a plurality of positions in a cross section of the exhaust pipe in the vicinity of the filter. 2. An exhaust pipe for guiding the gas in the device housing to the outside of the device, a fan for discharging the gas to the outside of the device, and a filter provided in the exhaust pipe for collecting dust contained in the exhaust gas. An exhaust system having a plurality of pressure detectors provided so as to make a pair on the upstream side and the downstream side of the filter in the exhaust pipe. 3. The exhaust system according to claim 1, wherein the exhaust pipe is provided on an upstream side of the filter, and the movable blade controls an inflow region of gas flowing into the filter. Based on data detected by a plurality of wind speed detectors or pressure detectors, a calculating means for calculating the distribution of the dust collected in the filter in the exhaust pipe cross section, and the distribution of the dust obtained by the calculating means And a control means for controlling the movable blade based on the above.