JP3717822B2 - Draft chamber exhaust system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an exhaust device for a draft chamber (fume hood).
[0002]
[Prior art]
In order to use a lot of chemicals in the draft chamber, a duct is connected to the upper part of the work space, and air in the work space is exhausted from this duct.
[0003]
In that case, a damper-shaped (butterfly-shaped) flow control valve is rotatably installed inside the duct, and the flow control valve is fully opened or close to it during work, and adjusted to close the flow control valve when not working. are doing.
[0004]
The rotation control of the flow control valve is performed by a motor, and the motor stop control is performed by selectively applying an opening detection body fixed to the rotating shaft to the opening position detection limit switch and the closing position detection limit switch. It is carried out.
[0005]
[Problems to be solved by the invention]
By the way, the user of the draft chamber wants a complete shut-off system in which the exhaust duct is completely closed by the flow control valve as the exhaust state when not working, and slightly opens the flow control valve slightly. Sometimes wants a micro-leakage system that is exhausting.
[0006]
For example, if there is no harmful gas in the work space in the non-working state, the complete shut-off method may be adopted, but if there is a risk of slight gas generation even in the non-working state, the micro-leakage method is adopted. There is a need.
[0007]
In addition, when many draft chambers are arranged side by side, branch ducts are connected to the main duct and each branch duct is connected to each draft chamber. In this case, harmful gases generated in other draft chambers are used. Is sometimes used in order to prevent from flowing into the unused draft chamber through each branch duct.
[0008]
Conventionally, the position detector is closed by shifting the mounting position of the limit switch for detecting the closed position or by preparing two types of opening detectors for the complete shut-off method and for the micro leak method. By changing the timing of hitting the position detection limit switch, it was possible to cope with a complete shut-off state and a minute leak state.
[0009]
That is, a completely shut-off type draft chamber and a micro leak-type draft chamber were separately manufactured.
[0010]
However, the method of changing the mounting position of the limit switch is cumbersome because the position of the screw hole into which the screw for fixing the limit switch is screwed must be changed. On the other hand, two types of opening detectors are prepared. However, there was a problem that processing and management took time.
[0011]
Moreover, in these conventional methods, since the complete shut-off state or the minute leak state is determined at the shipping stage, if the user tries to switch the closed state of the flow control valve after purchasing the draft chamber, the construction is troublesome. There was also a problem.
[0012]
Furthermore, there are cases where the user wants to change the flow rate in the minute leak state in response to changes in the work content in the draft chamber, but conventionally, the exhaust flow rate in the minute leak state remains in a preset state. The construction of changing the amount of leakage after purchasing the draft chamber was also troublesome.
[0013]
An object of the present invention is to improve such a current situation.
[0014]
[Means for Solving the Problems]
According to the first aspect of the present invention, there is provided a work space surrounded by walls, doors, and the like, and an exhaust passage for sucking the air in the work space to the outside. In a draft chamber provided with a flow control valve that can be operated by an actuator, a first sensor that detects an opening posture of the flow control valve, a second sensor that detects a closing posture of the flow control valve, and at least one of both sensors An adjusting means is provided that can adjust the posture detection timing of the flow rate control valve by either one of the sensors.
[0015]
According to a second aspect of the present invention, in the first aspect, the sensor is a contact-type limit switch, while the flow rate adjusting valve is in a damper shape (or butterfly shape) that rotates integrally with a rotating shaft that extends across the exhaust passage. And a rotation driving actuator such as a motor is connected to a portion of the rotating shaft exposed to the outside of the exhaust flow path, and the first sensor and the second are rotated by the rotation of the rotating shaft. An opening detection body that selectively contacts the sensor is fixed.
[0016]
Further, an opening detecting body by the second sensor is provided as the adjusting means by providing a mounting plate to which the second sensor is fixed so as to be able to rotate stepwise around the axis of the rotating shaft. Detection timing can be adjusted steplessly.
[0017]
[Operation and effect of the invention]
According to the present invention, for example, when the exhaust passage is closed, the complete shutoff method and the micro leak method are provided according to the user's request. In providing draft chambers with different postures, it is not necessary to manufacture a plurality of types of draft chambers with different exhaust modes, and one type of draft chamber is manufactured, and the flow rate by the sensor is operated by operating the posture adjusting means. By simply adjusting the attitude detection timing of the control valve, it is possible to meet different user needs.
[0018]
Accordingly, it is possible to reduce the labor of manufacturing the draft chamber and the labor of product management. In addition, since the exhaust passage can be easily closed or opened even after it has been delivered to the user, there is also an advantage that it is possible to respond appropriately to changes in work content.
[0019]
According to the second aspect, since the posture of the mounting plate can be adjusted steplessly, the exhaust amount in the closed state in the minute leak method can be adjusted steplessly, and as a result, the work content can be changed. Can be handled more accurately.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0021]
(1). First embodiment (FIGS. 1 to 6)
≪Overview≫
1 to 6 show a first embodiment. FIG. 1 is a perspective view of a draft chamber. As shown in FIG. 1, the draft chamber includes left and right side plates 1, a top plate 2, and a back plate and a bottom plate that are hidden from view in the drawing. The left and right side plates 1, the top plate 2, the back plate and the bottom plate constitute a main body, and a portion surrounded by these is a work space 3 having a forward opening.
[0022]
The upper part of the opening of the work space 3 is closed by the rammer panel 4, and a door frame 5 that moves up and down along the front end edge of the side plate 1 is disposed at a lower part thereof. A plurality of sliding doors 6 having a transparent plate property are attached to the door frame 5. Therefore, the sliding door 6 can be opened and the work can be performed, or the door frame 5 can be greatly lifted for the work.
[0023]
An inspection panel 7 is disposed between the front ends of the left right plate 1 and above the top plate 2. In this embodiment, as shown by the arrow A, the inspection panel 7 can be rotated downward about its lower edge, thereby opening the space above the top 2 forward. .
[0024]
Although not shown, the ceiling plate 2 is provided with an illumination device for the work space 3, and the inspection panel 7 is rotated downward to replace or inspect the lamp or adjust the exhaust device 8 described later. And so on.
[0025]
The inspection panel 7 is not limited to a pivoting type, but can be a hooking type that is detachable with respect to the left and right side plates, or can be fixed to the side plate 1 with screws. In short, what is necessary is just to be able to open the space above the top plate 2. The rammer panel 4 may be a fixed type, a type that can be easily removed, or an openable type.
[0026]
A joint duct 9 constituting the exhaust device 8 is fixed to the top plate 2 of the main body. The joint duct 9 is open to the work space 3, and a branch duct 10 made of a tube material such as a bellows-like flexible tube or pipe is connected to the joint duct 9, and the branch duct 10 is further connected to the main duct 11. ing. In the present embodiment, the exhaust duct is constituted by the joint duct 9 and the branch duct 10.
[0027]
A suction fan and a vacuum pump are connected to one end of the main duct 11 and can be exhausted simultaneously from the work spaces 3 of a number of draft chambers. A suction fan can be provided in each branch duct 10 of each draft chamber.
[0028]
≪Details of exhaust system≫
Hereinafter, the exhaust device 8 will be described with reference to FIG. 2 is a partially broken perspective view, FIG. 3 is a partially broken plan view, FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3, FIG. 5A is a sectional view taken along the line VV in FIG. FIG.
[0029]
As shown in FIGS. 2 and 5, the upper portion of the joint duct 9 is a small diameter portion 9 a, and a branch duct 10 is fitted into the small diameter portion 9 a and fixed with a band 12. A flange 12 b is provided at the lower end of the joint duct 9, and the flange 12 b is fixed to the top plate 2. In this embodiment, the joint duct 9 is made of a synthetic resin to prevent corrosion, but may be made of a corrosion-resistant metal.
[0030]
A butterfly flow control valve (damper) 13 is disposed inside the joint duct 9. The flow rate adjusting valve 13 is made of synthetic resin, and is fixed to a rotating shaft 14 that extends in a direction perpendicular to the axis of the joint duct 9. The flow rate adjusting valve 13 includes a cylindrical portion 13a in which the rotating shaft 13 is fitted.
[0031]
In the present embodiment, the flow control valve 13 is composed of three members, a cylindrical portion 13a and two semicircular valve bodies, and the valve body is welded to the cylindrical portion 13a to form a single form. . Of course, it may be molded as an integral part from the beginning, or the rotating shaft 14 may be integrally molded.
[0032]
The joint duct 9 is integrally provided with a bearing portion 15 into which one end portion of the cylindrical portion 13a is rotatably fitted. In assembling the flow rate adjusting valve 13 to the joint duct 9, the cylindrical portion 13 a is inserted into the joint duct 9 and then a semicircular valve body is welded to the cylindrical portion 13 a.
[0033]
When the flow rate control valve 13 is formed from the beginning in a form in which the cylindrical portion 13a is continuously provided, the joint duct 9 is constituted by two members formed in a split shape, as shown by a one-dot chain line in FIG. After the two members are overlapped with the cylinder portions 13a and 13b of the flow rate control valve 13 fitted, the joint portions of the two members may be welded or bonded together.
[0034]
The rotating shaft 14 penetrates through a support plate 16 arranged in a vertical posture outside the joint duct 9. The support plate 16 includes a pair of legs 17 that are welded to the joint duct 9. In this embodiment, the support plate 16 is also made of a synthetic resin (of course, it may be made of a metal plate).
[0035]
A bracket 18 having a U-shape in plan view (may be box-shaped) is fixed to the support plate 16 by screwing or the like, and a motor 19 as an example of an actuator is fixed to the outer surface of the bracket 18. The output shaft 20 of the motor 19 is connected to the rotating shaft 14 by a coupling 21. The cylinder portion 13 a of the flow rate adjusting valve 13 is fixed to the rotating shaft 14 with a screw 24.
[0036]
Therefore, the rotation of the flow rate adjusting valve 13 can be controlled by driving the motor 18 forward and backward. The motor 19 may be a motor that can control the rotation in small increments, such as a step motor or a servo motor, or a normal motor with a reduction gear. The bracket 19 of the motor 19 is covered with a removable cover 22.
[0037]
A fan-shaped plate-shaped opening detector 23 is integrally formed in a portion of the cylindrical portion 13a of the flow rate control valve 13 outside the support plate 16 with a slight clearance from the support plate 16 (see FIG. The opening degree detection plate 23 may be a separate member from the cylindrical portion 13a).
[0038]
As an example of a sensor, a first limit switch 25 for detecting an open state and a second limit switch 26 for detecting a closed state are allocated to both sides of the opening detector 23 in front and behind. It is arranged.
[0039]
The first limit switch 25 is fixed to the support plate 16 with a screw (not shown), and when the flow control valve 13 is in a fully open position as shown in FIG. It is set so that the outer peripheral surface comes into contact with the contact 25a to be turned on (energized and a signal flows), and the motor 19 stops rotating.
[0040]
The second limit switch 26 is fixed to a mounting plate 27 fixed to the support plate 16 with a screw. The second limit switch 26 is turned on when the outer peripheral surface of the opening detector 23 abuts on the contact 26a (the current is applied). The motor 19 is set to stop rotating when a signal flows).
[0041]
The mounting plate 27 is an example of an adjusting means, and as can be easily understood from FIG. 5, a slit hole 28 that fits tightly into the cylinder portion 13 b of the flow rate adjusting valve 13 is formed, and further, the rotating shaft 14 is the center. An elongated arc-shaped long hole 29 is formed, and is inserted into the long hole 29 and fixed to the support plate 16 with a screw 30.
[0042]
≪Advantages of action and embodiment≫
Accordingly, the opening detection body is obtained by loosening the screw 30 and rotating the mounting plate 27 about the axis of the rotary shaft 14 and then tightening the screw 30 to fix the mounting plate 27 to the support plate 16. 23 can adjust the timing at which the second limit switch 26 is operated, that is, the closing angle of the flow control valve 13 in a stepless manner.
[0043]
In the example shown in FIG. 6 (A), the second limit switch 26 is turned on by the opening detector 23 and the motor 19 is stopped when the inside of the joint duct 9 is completely shut off by the flow control valve 13. It is set to do. That is, in this case, a complete shut-off system is used.
[0044]
In the example shown in FIG. 6B, the mounting plate 27 is rotated counterclockwise by a slight angle θ as compared with the state of FIG. In this case, since the timing at which the opening detector 23 hits the contact 26a of the second limit switch 26 is earlier than in the case of (A), a slight leakage method in which some exhaust is performed from the joint duct 9 even in the closed state. It has become.
[0045]
The maximum closing angle of the flow control valve 13 can be freely set as necessary, and can be set so that the rotation of the flow control valve 13 is stopped in a state where exhaust is performed at a considerable flow rate.
[0046]
In this embodiment, since the opening degree detection body 23 is integrally formed with the cylinder part 13a of the flow rate control valve 13, the opening hole 28 is formed in the mounting plate 27. However, the opening degree detection plate 23 is the cylinder part 13a. And the mounting plate 27 may be formed with a round hole that fits into the cylindrical portion 13b.
[0047]
When the mounting plate 27 is employed as the adjusting means as in the present embodiment and the second limit switch 26 is attached thereto, the operation timing of the first limit switch 25 remains constant, and only the operation timing of the second limit switch 26 is provided. Therefore, it is suitable for a method of adjusting only the opening degree in the closed state.
[0048]
As shown by the solid line in FIG. 1, the adjusting portion of the exhaust device 8 is attached to the joint duct 9 in a state of projecting sideways in the front view of the draft chamber, but as shown in FIG. If it is attached to the joint duct 9 in a state facing the front side, there is an advantage that the work can be easily performed when the posture of the mounting plate 27 is changed manually as in this embodiment.
[0049]
As indicated by a one-dot chain line in FIG. 4, the opening detection body by the first limit switch 25 is obtained by overlappingly fixing the attachment plate 27 for the second limit switch 26 and the attachment plate 27 ′ of the target shape to the support plate 16. It is also possible to adjust the detection timing of 23.
[0050]
In this case, the two attachment plates 27 and 27 'are both fitted into the cylindrical portion 13a, but the base end portions where both the attachment plates 27 and 27' are fitted to the cylindrical portion 13a are not interfered with each other. , One is overlapped with the support plate 16 and the other is formed in a stepped shape so as to be spaced from the support plate 16.
[0051]
(2). Second embodiment (FIGS. 7 to 8)
7 to 8 show a second embodiment. 7 is a front view, and FIG. 8 is a sectional view taken along the line VIII-VIII in FIG.
[0052]
In this embodiment, when the second limit switch 26 is provided on the mounting plate 27 that can be rotated around the axis of the rotary shaft 14 as in the first embodiment, the opening detector 23 has an arcuate outer peripheral surface. While forming the gear portion 32, the auxiliary motor 33 is fixed to the back surface of the support plate 16, and the gear 34 fixed to the output shaft of the auxiliary motor 33 is engaged with the gear portion 32 of the opening detector 23.
[0053]
Although details are omitted, the mounting plate 27 is not fixed to the support plate 16 by the screw 30, and the screw 30 allows the opening detection body 23 to be supported by the support plate 16 in a state in which the opening detection body 23 is allowed to rotate. It is closely attached to.
[0054]
Therefore, the timing at which the second limit switch 26 operates can be remotely adjusted by driving the auxiliary motor 33 and rotating the mounting plate 27. As can be understood from this example, the adjusting means such as the mounting plate 27 may be adjusted not only manually but also automatically (remotely) by an actuator (power driving means) such as a motor.
[0055]
In this example, the mounting plate 27 and the auxiliary motor 33 constitute an adjusting means. The auxiliary motor 33 may be fixed to the outer surface of the support plate 16. It is also possible to use other actuators such as electromagnetic solenoids.
[0056]
(3). Third embodiment (FIG. 9)
FIG. 3 shows a third embodiment. In this embodiment, the second opening detector 23 'is overlapped with the first opening detector 23', the first limit switch 25 is operated by the first opening detector 23 ', and the second opening detector 23' is operated. The second limit switch 26 is operated at 23 ″. In this example, both limit switches 25 and 26 are fixed to the support plate 16.
[0057]
Both opening degree detectors 23 'and 23 "rotate integrally with the rotary shaft 14, but the second opening degree is detected from an arc-shaped elongated hole 35 formed in the second opening degree detector 23". By screwing the screw 36 into the detection body 23, the relative attitude between the second opening detection body 23 ″ and the first opening detection body 23 ′ can be adjusted. In this case, the second opening detection body 23 ″ corresponds to the adjusting means.
[0058]
The contact 25a of the first limit switch 25 and the contact 26a of the second limit switch 26 have different distances from the support plate 16. Therefore, the contact 25a of the first limit switch 25 has a first opening degree. The contact 26a of the second limit switch 26 contacts only the detection body 23 ', and the contact 26a of the second limit switch 26 contacts only the second opening detection body 23 ".
[0059]
(4) Others The present invention can be embodied in various ways other than the above embodiment. For example, the form of the flow control valve is not limited to the damper system (butterfly system) as in the embodiment, but may be another form / structure such as a needle type or a shutter type.
[0060]
Further, the sensor is not limited to the limit switch (micro switch), and other contact type switches and photoelectric non-contact type sensors can be employed. Furthermore, the adjusting means is not limited to a plate-like member such as the illustrated mounting plate or the second opening detector, but may be other forms such as an arm.
[0061]
The type of draft chamber is not limited to the type with only the front face opened, but there are those with doors on two sides and those with doors on all four sides, but the present invention is applicable to any draft chamber. it can.
[Brief description of the drawings]
FIG. 1 is an external perspective view of a draft chamber according to a first embodiment.
FIG. 2 is a partially broken perspective view of the exhaust device.
FIG. 3 is a partially broken plan view of the exhaust device.
4 is a cross-sectional view taken along the line IV-IV in FIG. 3;
5A is a cross-sectional view taken along the line VV in FIG. 3, and FIG. 5B is a separation view of the mounting plate and the rotating shaft.
FIG. 6 is a diagram showing an operation.
FIG. 7 is a front view of the second embodiment.
8 is a cross-sectional view taken along the line VIII-VIII of FIG.
FIG. 9 is a front view of a third embodiment.
[Brief description of symbols]
DESCRIPTION OF SYMBOLS 1 Side plate 2 Top plate 3 Work space 7 Inspection panel 8 Exhaust device 9 Joint duct 10 which forms exhaust flow path Branch duct 11 which forms exhaust flow path 11 Main duct 13 Flow control valve 14 Rotary shaft 16 Support plate 19 Motor 23 Opening degree Detectors 25 and 26 Limit switch 27 as an example of sensor Mounting plate 29 as an example of adjusting means Arc-shaped slot 30 Screw

Claims (2)

A work space enclosed by walls, doors, etc., and an exhaust passage for sucking the air in the work space to the outside are provided. Inside the exhaust passage, the flow rate can be controlled by an actuator such as a motor. In a draft chamber provided with a valve,
The first sensor for detecting the opening posture of the flow control valve, the second sensor for detecting the closing posture of the flow control valve, and the posture detection timing of the flow control valve by at least one of the two sensors can be adjusted. Adjusting means,
Draft chamber exhaust system. While the sensor is a contact limit switch,
The flow rate control valve is configured in a damper shape (or butterfly shape) that rotates integrally with a rotary shaft that extends across the exhaust flow path, and a motor that is exposed to the outside of the exhaust flow path on the rotary shaft. And an opening detector that selectively contacts the first sensor and the second sensor by rotation of the rotation shaft is fixed.
Further, an opening detecting body by the second sensor is provided as the adjusting means by providing a mounting plate to which the second sensor is fixed so as to be able to rotate stepwise around the axis of the rotating shaft. The detection timing can be adjusted steplessly,
The exhaust device for a draft chamber according to claim 1.

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