Safety work device

Abstract

The present invention provides a safety work device in which the floating of chemicals and contaminants into a work space is suppressed while a front shutter is closed. This safety work device includes: a work space; and a vertically movable front shutter on the front face of the work space. A work opening is formed below the front shutter when the front shutter is moved upward. The safety work device has an exhaust port through which air is discharged from the work space, and an exhaust flow passage leading from the exhaust port. When the front shutter is closed, a housing-interior opening is formed at the upper portion of the front shutter.

Description

safety work equipment

[0001] The present invention relates to a safety work apparatus such as a safety cabinet or a draft chamber.

[0002] A safety work device is known that has a shutter on the front and exhausts the air inside it, allowing work to be done safely. As an example, Patent Document 1 discloses a safety cabinet that has a work space and a shutter and exhausts the air inside the work space.

[0003] Japanese Patent Application Laid-Open No. 2006-122816

[0004] In the safety cabinet described in Patent Document 1, air flows in through an opening under the shutter during operation and is exhausted to the outside by a fan. This creates an appropriate air flow within the work space. However, when the shutter is closed, excessive negative pressure is created within the work space, resulting in unexpected strong wind currents. For example, high-speed air flows through tiny gaps between the shutter and the work table, or air flows in through gaps around the shutter. These air currents can cause residual chemicals and contaminants remaining in the work space to rise, posing a risk of contamination inside the unit by contaminating the walls of the work space, or a risk of leakage outside the unit via unexpected routes.

[0005] In order to solve the above problems, the present invention prevents excessive negative pressure in the work space even when the shutter is closed, and realizes the formation of a laminar flow in the work space. This prevents chemicals and contaminants handled in the work space from floating up into the work space, thereby preventing contamination inside the machine and leakage outside the machine.

[0006] An example of the safety work device of the present invention for solving the above problems is as follows.

[0007] A safety work device having a work space and a front shutter that can be moved up and down in front of the work space, which forms a work opening below the front shutter when moved upward, and which has an exhaust port for exhausting air from the work space and an exhaust flow path from the exhaust port, and when the front shutter is closed, an opening within the housing is formed at the top of the front shutter.

[0008] According to the present invention, even when the front shutter is closed, chemicals and contaminants handled in the work space are prevented from flying up into the work space, thereby preventing contamination inside the machine and leakage outside the machine.

[0009] Further configurations and effects of the present invention will become apparent from the entire specification below.

[0010] FIG. 1 is an explanatory diagram of an embodiment of the present invention with the front shutter in an open state. FIG. 2 is an explanatory diagram of an embodiment of the present invention with the front shutter in a closed state. FIG. 3 is an explanatory diagram of another embodiment of the present invention with the front shutter in an open state. FIG. 4 is an explanatory diagram of another embodiment of the present invention with the front shutter in a closed state. FIG. 5 is an explanatory diagram of another embodiment of the present invention. FIG. 6 is an explanatory diagram of an embodiment of the main part of FIG. 3. FIG. 7 is an explanatory diagram of an embodiment of the main part of FIG. 7. FIG. 7 is an explanatory diagram of another embodiment of the present invention. FIG. 8 is an explanatory diagram of another embodiment of the present invention.

[0011] 1A is an explanatory view of a safety work device according to an embodiment of the present invention when the front shutter is open. In order to explain the structural features, a schematic cross-sectional view will be used.

[0012] A workbench 2 is configured on top of a lower housing 1. It has a back panel 3a on the back and an upper housing 5 on the top. It has a front shutter 4 on the front, and the area surrounded by 2, 3a, 5, and 4 is the work space. 3b is the back housing, and the space surrounded by 3a and 3b is the internal exhaust duct 22. Note that while Fig. 1A shows an example in which the internal exhaust duct 22 is integrated with the safety work device to form the exhaust path 3, the exhaust path may also be configured separately from the safety work device in the form of separate piping, etc.

[0013] Reference numeral 50 denotes an external exhaust duct. This duct is connected to the internal exhaust duct 22 and guides the exhaust air from the safety work device to the outside. Reference numeral 51 denotes an exhaust fan. In FIG. 1A, it is configured separately from the safety work device, and can be placed on the building side of a laboratory or factory, for example. Of course, this does not exclude the installation on the safety work device side.

[0014] 1A shows the front shutter 4 in an open state, i.e., the front shutter 4 has moved upward to form an opening, forming a front opening 24 between the front shutter 4 and the workbench 2. At this time, air is exhausted by the exhaust fan 51, creating a negative pressure on the safety device side of the exhaust fan. As a result, an air flow is generated to eliminate the pressure difference. As a result, air from outside passes through the front opening 24 and, for example, through air flow 30 into the work space 23. Then, for example, it passes through a prefilter 20 and is introduced into the internal exhaust duct 22. The introduced air passes, for example, through a HEPA filter 21 and, as air flow 31, is finally exhausted by the exhaust fan 51.

[0015] Next, the most significant feature of this embodiment will be described with reference to FIGS. 1A and 1B.

[0016] 1A and 1B, a front housing 6 is formed on the upper front surface of the front shutter 4. An upper opening 10 is provided between the front housing 6 and the upper housing.

[0017] 1A, that is, when the front shutter 4 is in the open state and moves upward in the figure, the front shutter 4 is configured to have an overlapping area with the upper housing 5. At this time, the existence of the upper opening 10 separates the workspace 23 due to the overlap between the front shutter 4 and the upper housing 5.

[0018] 1B , that is, when the front shutter 4 is moved downward and is thus in a closed state, the front opening 24 disappears and the air flow 30 disappears. At this time, as a result of the downward movement of the front shutter 4, the overlap between the front shutter 4 and the upper housing 5 is eliminated. This does not have to be a complete elimination, as long as the overlap is at least partially eliminated. As a result, a new intra-casing opening 12 is formed between the front shutter 4 and the upper housing 5. This forms a new air flow 32 toward the working space 23 via the upper opening 10 and the intra-casing opening 12. This new air flow 32 forms a downflow, and then passes through air flow 33 and air flow 31 and is exhausted to the outside by the exhaust fan 51.

[0019] In this way, by moving the front shutter, a downflow is automatically formed when the front shutter is closed, and the generation of excessive negative pressure can be prevented, thereby achieving the characteristic effect of suppressing the floating up of medicines and contaminants into the working space, thereby suppressing contamination inside the machine and leakage outside the machine.

[0020] It should be noted that this does not preclude the installation of a fan or air blower in the upper part of the work space.

[0021] 1A and 1B, the feature of the present invention is that a new opening is formed above the front shutter by moving the front shutter, thereby enabling the formation of a downflow in the working space. Therefore, as long as this new structural concept is satisfied, various modifications and differences in structure are all included in the scope of the disclosure of this embodiment.

[0022] Furthermore, the safety work device according to the present invention can be applied to various devices, and as an example, it can be applied to a draft chamber, a safety cabinet, and the like.

[0023] The basic configuration of this embodiment is the same as that of embodiment 1. The difference between this embodiment and embodiment 1 is that a current plate 11 is additionally provided.

[0024] Fig. 2A is a view corresponding to Fig. 1A. The difference is that the rectifying plate 11 is located above the work space 23, and the work space is formed between the rectifying plate 11 and the work table 2. When the front shutter 4 is moved up and in the open state, the front shutter 4 is configured to have an overlapping area with the upper housing 5 as well as with the rectifying plate 11.

[0025] Next, Fig. 2B is a diagram corresponding to Fig. 2B. When the front shutter 4 moves downward to the closed state, the front shutter 4 eliminates the overlapping area with the upper housing 5, but is configured to still have an overlapping area with the rectifying plate 11. As a result, the air flow 32 in Fig. 1A flows toward the working space 23 via the rectifying plate 11. This makes it possible to prevent excessive local differences in the air flow 32, and also increases the wind speed of the downflow, making it possible to further suppress the floating of chemicals and contaminants into the working space.

[0026] Various configurations can be applied to the straightening plate 11, but for example, it can be a plate-like structure in which a large number of polygonal holes, such as a honeycomb, are formed in metal or resin, etc., and an opening rate of approximately several tens of percent is formed.

[0027] At this time, it is desirable to set the opening ratio within an appropriate range, taking into consideration that if the opening ratio is too low, the airflow resistance will be strong and the downflow will be weaker, and conversely, if the opening ratio is too high, the straightening effect of the downflow will be reduced.

[0028] A desirable example is a plate-like structure made of stainless steel or the like, configured as a punched plate with many holes drilled in a plane, with an opening rate of about 20 to 40%, more desirably about 20 to 30%.

[0029] From the viewpoint of ease of manufacture, it is desirable that the aperture ratio of the current plate 11 be uniform across the entire surface.

[0030] On the other hand, from the viewpoint of strengthening the downflow in the vicinity of the front shutter 4, it is desirable to make the aperture ratio of the current plate 11 higher on the front shutter 4 side than on the rear plate 3a side. However, even in this case, it is more desirable to change the aperture ratio between 20% and 40% in order to avoid the occurrence of turbulence in the working space 23.

[0031] The configuration of the current plate is not limited to the above, and any plate-like structure with at least a portion open is included in the scope of the disclosure of this embodiment.

[0032] This embodiment is obtained by adding additional components to the second embodiment, and is premised on the inclusion of the components described in the first and second embodiments.

[0033] Figure 3 is an explanatory diagram based on Figure 2B. The difference between Figure 3 and Figure 2B is that a light 15 is included. This light 15 emits light downward to illuminate the work space. Therefore, it is desirable to install the light near the center, for example, in order to reduce the number of lights.

[0034] Fig. 4 is an explanatory diagram of an example of the main parts of the lighting 15 of Fig. 3. A number of openings are formed in the rectifying plate 11. An opening of a size larger than the number of openings in the rectifying plate 11 is formed in a part of the rectifying plate 11. If the size of the number of openings in the rectifying plate 11 is represented as W1 in the figure, then this means a larger opening of W2. The lighting 15 is arranged corresponding to this opening of W2. In Fig. 4, among the devices constituting the lighting 15, the LED light-emitting device portion 15a is arranged so as to fit within W2.

[0035] This prevents the light from the lighting 15 from being blocked by the rectifying plate 11, thereby improving the light utilization efficiency of the lighting 15. 15b denotes a circuit board and heat dissipation means, such as a printed circuit board for driving the LEDs and a heat sink for heat dissipation. Power is supplied to 15a via 15b, and light is emitted downward from the LEDs.

[0036] As shown in Fig. 3, it is possible to illuminate the work space even with the rectifying plate 11, and by installing the lighting 15 relative to the rectifying plate in the configuration shown in Fig. 4, the light utilization efficiency of the lighting 15 can be effectively utilized. Furthermore, when the rectifying plate 11 is made of metal such as stainless steel, it is possible to have the rectifying plate 11 also function as an auxiliary heat sink to quickly dissipate heat generated by the lighting 15. In this case, since the rectifying plate 11 is large, it becomes equipped with a powerful heat dissipation means for the lighting 15, and the lifespan of the lighting 15 can also be improved.

[0037] This embodiment is obtained by adding additional components to the second embodiment, and is premised on the inclusion of the components described in the first and second embodiments.

[0038] Fig. 5 is an explanatory diagram based on Fig. 2B. The difference between Fig. 5 and Fig. 2B is that the static electricity eliminator 16 is provided. The static electricity eliminator 16 is positioned above the rectifying plate 11. This is because if the static electricity eliminator 16 were located above the rectifying plate 11, the presence of the rectifying plate 11 would reduce the static electricity elimination performance of the static electricity eliminator 16.

[0039] FIG. 6 is an explanatory diagram of a main part of an example of the static electricity removing device 16 in this embodiment, which is an embodiment using an ionizer.

[0040] A static eliminator 16 is installed in an opening provided in the rectifier plate 11. Fig. 6 illustrates an example in which an ion generator is used as the static eliminator 16. Reference numeral 16a denotes a needle-shaped electrode, 16b denotes a planar electrode, and this is an example of a so-called ionizer that generates ions by discharging a high voltage between 16a and 16b. Reference numeral 16c denotes a support for the needle-shaped electrode 16a. High voltages of opposite polarities are applied to 16a via an insulatingly coated wire 16d and to 16b via an insulatingly coated wire 16e.

[0041] The actual high voltage is supplied from a high-voltage generating circuit, but since this is a general concept, a detailed description will be omitted. It should be noted that a high voltage is required, and the current itself is close to zero, making it possible to continue discharging for a long period of time. The term "high voltages of different polarities" also includes cases where one polarity is 0 or GND. Furthermore, configuring the power supply so that the polarity is not constant but changes midway is more desirable, as this will enable the static elimination effect to be achieved for both positive and negative static electricity.

[0042] Although FIG. 6 shows 16a to 16e formed as hollow, in reality, for the purpose of fixing, they are arranged on the rectifying plate 11 via fixing members made of an insulating material such as plastic.

[0043] As shown in the configuration of Figure 6, the static electricity remover 16 is positioned in correspondence with the opening of the rectifying plate 11 and is positioned so as to maintain the opening of the rectifying plate 11, so that the air flow 32 of Figure 2B causes the ions generated by the static electricity remover 16 to be introduced into the working space by downflow.

[0044] Returning to Fig. 5, the position of the static eliminator 16 is not particularly limited, but it is more desirable to dispose it shifted from the center toward the front shutter 4 as shown in Fig. 5. This is because there is a high risk of dust, contaminants, etc. adhering to the inside of the front shutter 4 due to static electricity.

[0045] This is because, while the other sides that form the work space can be made of metal and thus capable of suppressing static electricity buildup, the front shutter 4 is required to be transparent and is therefore made of an insulating material such as glass or plastic. For this reason, by displacing and positioning the static eliminator 16 toward the front shutter 4 and allowing ions to be irradiated intensively onto the inside of the front shutter 4, it becomes possible to efficiently eliminate static electricity from areas where it is most necessary to eliminate it, and the number of static eliminators can be kept to a minimum.

[0046] It is desirable that the static eliminator 16 is configured so that it does not operate when the front shutter 4 is open, i.e., during work, but operates when the front shutter 4 is closed. This can be achieved by providing a sensor, switch, or the like to link the operation of the static eliminator 16 with the position and state of the front shutter 4.

[0047] As an example, Fig. 7 shows an example in which a switch means is provided corresponding to the position of the front shutter 4. Reference numeral 17 denotes a switch, 17a denotes a movable contact that moves integrally with the front shutter, and 17b denotes a fixed contact that is fixed to the front housing 6. The operation will be explained using Figs. 8A and 8B.

[0048] 8A is an explanatory diagram showing that the front shutter 4 is in a closed state and a high voltage is being supplied to the static eliminator 16. The movable contact 17a and the fixed contact 17b come into contact and are electrically connected to each other. As a result, the voltage supplied to the fixed contact 17b is supplied to the static eliminator 16 as 18a.

[0049] 8B is an explanatory diagram showing that the front shutter 4 is in an open state and high voltage is not being supplied to the static eliminator 16. When the front shutter 4 moves upward, the movable contact 17a also moves upward. This causes the movable contact 17a to separate from the fixed contact 17b, and the two become non-conductive. This cuts off the voltage supply to the static eliminator 16.

[0050] The example in Figure 8 is merely one example, and if the high voltage supply to the static electricity removal device 16 is controlled using a sensor or switch linked to the open or closed state of the front shutter, other realization means are also included in the scope of this embodiment.

[0051] Furthermore, instead of continuously supplying electricity when the sensor or switch is in operation, by using an additional device such as a limit switch that stops the supply of electricity at a preset time, it is possible to realize a configuration in which electricity is removed only for a certain period of time immediately after the front shutter 4 is closed, for example, immediately after work is completed.

[0052] 9 shows a diagram of this embodiment corresponding to FIG. 3 or 5. This embodiment has the configurations of both the third and fourth embodiments, and is an example in which both the illumination 15 and the static eliminator 16 are provided. As shown in FIG. 9, the positional relationship between the illumination 15 and the static eliminator 16 is preferably such that the static eliminator 16 is positioned closer to the front shutter 4 than the illumination 15. This is because the reasons explained in the third and fourth embodiments can be achieved simultaneously.

[0053] FIG. 10 is an explanatory diagram based on FIG.

[0054] This embodiment is used additionally to the invention disclosed in any one of embodiments 1 to 5. This embodiment is characterized in that a damper is provided corresponding to the upper opening 10.

[0055] 10 shows an example of a damper, which is configured by a combination of a cover 18 and a spring 19. This is provided in correspondence with the upper opening 10.

[0056] When the front shutter 4 is closed, i.e., in the closed state, the pressure in the work space drops due to the exhaust by the exhaust fan 51. The difference between this pressure and atmospheric pressure generates downward pressure at the upper opening 10. Here, by providing a downward-opening damper corresponding to the upper opening 10, the damper opens downward due to the force caused by the pressure difference because atmospheric pressure is greater, and air is introduced through the upper opening 10. At this time, since the damper operates due to the pressure difference, it is necessary to set its spring force to be weak.

[0057] Although not shown, when the front shutter is in the open state, i.e., when the front shutter has moved up, as shown in FIG. 1A, a space is separated between the working space 23 and the upper opening 10, so that no pressure is applied to the damper, and the force of the spring 19 closes the lid 18.

[0058] This damper can automatically close the upper opening 10 when the exhaust fan 51 is stopped for an extended period of time, particularly during long vacations or inspection work, thereby making it possible to prevent dust and other debris from entering the safety work device.

[0059] Figure 11 is an explanatory diagram corresponding to Figure 2B. The difference from Figure 2B is that an upper pre-filter 25 is provided. As a result, air from the upper opening 10 passes through the upper pre-filter 25 and then flows into the work space 23 as an air flow 32. Therefore, with the front shutter 4 closed, it is possible to prevent dust and other particles from entering the safety work device.

[0060] The above-described embodiments of the present invention can be used alone or in combination, and these cases are also included within the scope of the present invention.

[0061] Furthermore, as long as the technical concepts detailed in the above-described embodiments are applied, any modifications or slight variations in the structure are also included within the scope of the present invention.

[0062] The inventions disclosed in this specification are, for example, as follows. <No. 1> A safety work device having a work space and a vertically movable front shutter in front of the work space, which forms a work opening below the front shutter when shifted upward, and which has an exhaust port for exhausting air from the work space and an exhaust flow path from the exhaust port, wherein an internal housing opening is formed above the front shutter when the front shutter is closed. <No. 2> The safety work device according to <No. 1>, which has an upper opening above the internal housing opening. <No. 3> The safety work device according to <No. 2>, which has an upper opening above the internal housing opening when the front shutter is closed, and which allows air to flow into the work space through the upper opening and the internal housing opening when the front shutter is closed. <No. 4> The safety work device according to <No. 3>, which has a rectifying plate above the work space. <No. 5> The safety work device according to <No. 4>, wherein the aperture ratio of the rectifying plate is higher on the side of the front shutter than on the back side of the safety work device. <No. 6> The safety work device according to <No. 4>, wherein the illumination is an LED, and is positioned and arranged in a hole formed in the rectifying plate, and the hole in which the LED is arranged is larger than the multiple holes for rectification formed in the rectifying plate. <No. 8> The safety work device according to <No. 4>, wherein the static electricity eliminator is positioned on the rectifying plate. <No. 9> The safety work device according to <No. 8>, wherein the static electricity eliminator is arranged shifted toward the front shutter on the rectifying plate. <No. 10> The safety work device according to <No. 9>, wherein the static electricity eliminator is a safety work device that operates when the front shutter is closed. <No. 11> In the safety work device described in <No. 9>, the static electricity eliminator is an ionizer having a needle-shaped electrode and a flat electrode, and the needle-shaped electrode is positioned and arranged in a hole in the rectifying plate, and the safety work device is configured so that air flows around the needle-shaped electrode.<No. 12> The safety work device according to <No. 4>, comprising a light and a static electricity eliminator positioned on the rectifying plate, the static electricity eliminator being disposed closer to the front shutter than the light. <No. 13> The safety work device according to <No. 2>, comprising a damper that opens downward, corresponding to the upper opening. <No. 14> The safety work device according to <No. 2>, comprising an upper pre-filter, corresponding to the upper opening.

[0063] 1: Lower housing 2: Work table 3a: Rear panel 4: Front shutter 5: Upper housing 6: Front housing 10: Upper opening 11: Rectifier plate 12: Opening inside housing 15: Lighting 16: Static electricity eliminator 20: Pre-filter 21: HEPA filter 22: Internal exhaust duct 23: Work space 24: Front opening 25: Upper pre-filter 30, 31, 32, 33: Air flow 50: External exhaust duct 51: Exhaust fan

Claims

1. A safety work device having a work space and a vertically movable front shutter in front of the work space, which forms a work opening below the front shutter when moved upward, an exhaust port for exhausting air from the work space, and an exhaust flow path from the exhaust port, and when the front shutter is closed, an opening within the housing is formed at the top of the front shutter.

2. A safety work device as claimed in claim 1, which has an upper opening above the opening inside the housing.

3. A safety work device according to claim 2, wherein when said front shutter is closed, air flows into said work space through said upper opening and said opening inside said housing.

4. A safety work device according to claim 3, further comprising a baffle plate above said work space.

5. A safety work device according to claim 4, wherein the aperture ratio of said baffle plate is higher on the front shutter side than on the rear side of said safety work device.

6. A safety work device according to claim 4, further comprising a light positioned on said baffle.

7. A safety work device as described in claim 6, wherein the lighting is an LED, positioned and arranged in a hole formed in the rectifying plate, and the hole in which the LED is arranged is larger than the multiple holes for rectifying purposes provided in the rectifying plate.

8. A safety work apparatus according to claim 4, further comprising a static electricity removing device positioned on said current plate.

9. A safety work device according to claim 8, wherein said static electricity removing device is disposed offset toward said front shutter side with respect to said current plate.

10. A safety working device according to claim 9, wherein said static electricity removing device operates when said front shutter is closed.

11. A safety work device as described in claim 9, wherein the static electricity removing device is an ionizer having a needle-shaped electrode and a flat electrode, the needle-shaped electrode is positioned and arranged in a hole in the straightening plate, and the safety work device is configured so that air flows around the needle-shaped electrode.

12. A safety work device according to claim 4, further comprising a lighting device and a static electricity removing device positioned on said straightening plate, said static electricity removing device being disposed closer to the front shutter than said lighting device.

13. A safety work device according to claim 2, further comprising a damper that opens downward in correspondence with said upper opening.

14. A safety work device according to claim 2, further comprising an upper pre-filter corresponding to said upper opening.

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