Automatic gate valve for preventing gas from flowing backwards

Abstract

The utility model relates to the field of gas control valves, in particular to an automatic gate valve for preventing gas from flowing backwards, which comprises a valve body base, a ventilation pipeline, an opening and closing driving mechanism, an opening and closing action mechanism and an air pressure balance mechanism are arranged on the valve body base, and the opening and closing driving mechanism comprises a PLC (programmable logic controller) control system and a driving cylinder. The opening and closing action mechanism comprises a gate plate sliding along the valve body base, and the PLC control system controls the driving air cylinder to drive the gate plate to be inserted into the ventilation pipeline in the radial direction and close the ventilation pipeline. The air pressure balance mechanism comprises a pressure balance valve which is communicated with the ventilation pipeline. According to the utility model, the cylinder automatically controlled by the PLC is used as a driving part, the response and action speed is high, the action in-place accuracy is high, the pipeline on-off control action can be timely and effectively completed, and the gas backflow during the downtime of the vacuum pump is prevented; after the flashboard is closed, the pressure balance valve performs balance adjustment on internal and external pressure of the pipeline to prevent flashboard opening faults.

Description

TECHNICAL FIELD

[0001] The utility model relates to a gas control valve field especially a kind of automatic gate valve to prevent gas backflow. BACKGROUND

[0002] More tail gas containing impurities and harmful substances is generated in semiconductor process, and a vacuum pump is usually used to create a negative pressure environment in the system to make the tail gas flow in a predetermined direction and be discharged. A shut-off valve needs to be added to the connecting pipeline of the vacuum pump to shut off the pipeline in time when the vacuum pump fails, so as to prevent gas backflow and affect product yield. However, since the pipeline diameter is large, the commonly used shut-off valves cannot act in time or not in place, affecting the shut-off effect. SUMMARY

[0003] The utility model aims at solving above-mentioned problem, provides a kind of automatic gate valve to prevent gas backflow, it uses the technical scheme as follows:

[0004] An automatic gate valve to prevent gas backflow includes a valve body base, an air passage, an opening and closing drive mechanism, an opening and closing action mechanism and a gas pressure balancing mechanism are arranged on the valve body base, the opening and closing drive mechanism includes a PLC control system and a drive cylinder, the opening and closing action mechanism includes a gate plate sliding along the valve body base, the PLC control system controls the drive cylinder to drive the gate plate to insert into the air passage along the radial direction, and the air passage is shut off;The gas pressure balancing mechanism includes a pressure balance valve, and the pressure balance valve is communicated with the air passage.

[0005] On the basis of the above-mentioned scheme, the opening and closing drive mechanism further includes a drive rack and a drive gear, the drive rack is fixedly connected with the piston rod of the drive cylinder, and the drive gear is engaged with the drive rack;The opening and closing action mechanism further includes a rotating arm, a connecting rod and a sliding plate, one end of the rotating arm is fixedly connected with the drive gear in the same shaft, the connecting rod is hingedly connected with the other end of the rotating arm and the sliding plate at both ends, the sliding plate slides along the valve body base, and the gate plate is fixedly installed on the sliding plate.

[0006] On the basis of the above-mentioned scheme, the drive gear is an incomplete gear, the part without teeth of the drive gear is a limiting groove, a limiting block is arranged in the limiting groove, and the limiting block is fixedly connected with the valve body base.

[0007] Preferably, longitudinal rollers and transverse rollers are rotatably arranged on the sliding plate, the longitudinal rollers are symmetrically arranged on both sides of the sliding plate and arranged in the vertical direction, and the transverse rollers are symmetrically arranged on both sides of the sliding plate and arranged in the horizontal direction.

[0008] Preferably, the heating device comprises a heating pipe fixedly installed in the valve body base and annularly arranged outside the vent pipe.

[0009] Preferably, the air pressure balancing mechanism further comprises an air pressure detection valve for detecting the air pressure in the vent pipe on the side of the gate away from the vacuum pump, and the pressure balancing valve is arranged on the side of the gate away from the vacuum pump.

[0010] Preferably, the utility model further comprises a protective shell fixedly installed on the valve body base, and the opening and closing driving mechanism and the opening and closing action mechanism are arranged in the cavity formed by the protective shell.

[0011] The utility model discloses the beneficial effects are: adopt the cylinder of PLC automatic control as driving part, reaction and action speed are fast, and action is in place high accuracy, can timely and effectively complete the pipeline on-off control action, prevent the gas backflow when vacuum pump outage;The pressure balancing valve is balanced and adjusted to the pressure inside and outside the pipeline after the gate is closed, prevents the gate opening failure;The vent pipe is annularly surrounded by the heating pipe, and impurities can be effectively prevented from depositing at the vent pipe. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 The utility model discloses a structure schematic view;

[0013] Figure 2 The utility model discloses an opening and closing driving mechanism structure schematic view;

[0014] Figure 3 The utility model discloses an opening and closing action mechanism structure schematic view;

[0015] Figure 4 The utility model discloses a heating device structure schematic view;

[0016] Figure 5 The utility model discloses a balancing valve structure schematic view. DETAILED DESCRIPTION

[0017] The utility model will be further described below in connection with the drawings and examples:

[0018] In the utility model, unless another definite provision and limitation, the terms "installation", "link", "connection", "fixing" and the like terms should be broad sense understanding, for example, can be fixed connection, also can be detachable connection, or integral;Can be directly connected, also can be indirectly connected through the intermediate medium, can be the intercommunication of two elements or the interaction of two elements. For ordinary skilled in the art, the above-mentioned terms can be understood according to the specific meaning of the utility model in specific circumstances.

[0019] In the description of the utility model, need understanding is, the term '' center '', '' length '', '' upper '', '' lower '', '' front '', '' back '', '' left '', '' right '', '' vertical '', '' horizontal '', '' top '', '' bottom '', '' internal '' and so on the orientation or position relation indicated is based on the orientation or position relation shown in the drawing, is only for the convenience of describing the utility model and simplifying the description, and is not indicating or implying that the device or element indicated must have a particular orientation, is constructed and operated in a particular orientation, therefore can not be understood as the limitation to the utility model. In addition, the term '' first '', '' second '' is only for the purpose of description, and can not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features limited by '' first '', '' second '' can explicitly or implicitly include one or more features. In the description of the utility model, unless otherwise specified, the meaning of '' multiple '' is two or more than two.

[0020] In the utility model, unless otherwise explicitly specified and limited, the '' upper '' or '' lower '' of the first feature in the second feature can include that the first and second features are in direct contact, or the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the '' above '', '' upper '' and '' upper surface '' of the first feature in the second feature include that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The '' below '', '' below '' and '' below '' of the first feature in the second feature include that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0021] As Figures 1 to 5 shown, an automatic gate valve for preventing gas backflow, including valve body base 11, the valve body base 11 is provided with air duct 13, opening and closing drive mechanism, opening and closing action mechanism and air pressure balance mechanism, the opening and closing drive mechanism includes PLC control system and drive cylinder 21, the opening and closing action mechanism includes the shutter 34 sliding along the valve body base 11, the PLC control system controls drive cylinder 21 to drive shutter 34 to be inserted into air duct 13 along the radial direction, and shut off air duct 13. As Figure 2 and Figure 3As shown, the opening and closing driving mechanism further comprises a driving rack 22 and a driving gear 23, the driving rack 22 is fixedly connected with the piston rod of the driving cylinder 21, and the driving gear 23 is engaged with the driving rack 22; the opening and closing action mechanism further comprises a rotating arm 31, a connecting rod 32 and a sliding plate 33, one end of the rotating arm 31 is coaxially fixedly connected with the driving gear 23, the connecting rod 32 is hingedly connected with the other end of the rotating arm 31 and the sliding plate 33 at two ends respectively, the sliding plate 33 slides along the valve body base 11, and the shutter plate 34 is fixedly installed on the sliding plate 33. After the PLC control system receives the shutdown signal of the vacuum pump, a command is sent to control the piston rod of the driving cylinder 21 to act, the driving rack 22 and the driving gear 23 are engaged, the driving gear 23 is driven to rotate, and then the rotating arm 31 and the connecting rod 32 are driven to rotate, finally the sliding plate 33 drives the shutter plate 34 to move linearly, and the air passage 13 is closed. After the PLC control system receives the signal that the vacuum pump returns to the normal working state, the piston rod of the driving cylinder 21 is controlled to act in the reverse direction, so that the shutter plate 34 moves away from the air passage 13, and the air passage 13 is opened. Preferably, the driving gear 23 is an incomplete gear, the part of the driving gear 23 without teeth is a limiting groove, a limiting block 24 is arranged in the limiting groove, the limiting block 24 is fixedly connected with the valve body base 11, and when the two sides of the limiting groove abut against the limiting block 24, the sliding plate 33 is respectively located at the limit positions at two ends under the driving of the connecting rod 32, so that the limiting block 24 and the limiting groove are cooperated to limit the moving range of the sliding plate 33. In order to make the sliding of the sliding plate 33 more smooth, longitudinal rollers 35 and transverse rollers 36 are rotatably arranged on the sliding plate 33, the longitudinal rollers 35 are symmetrically arranged on the two sides of the sliding plate 33 and arranged in the vertical direction, the transverse rollers 36 are symmetrically arranged on the two sides of the sliding plate 33 and arranged in the horizontal direction, and the longitudinal rollers 35 and the transverse rollers 36 respectively slide in different faces of the valve body base 11, which can not only reduce the friction in the moving process of the sliding plate 33, but also limit the moving track of the sliding plate 33.

[0022] As shown in Figure 4 and Figure 5 As shown, the air pressure balancing mechanism comprises a pressure balance valve 42, and the pressure balance valve 42 is communicated with the air passage 13. The air pressure balancing mechanism further comprises an air pressure detection valve 41, which is used to detect the air pressure in the air passage 13 on the side away from the vacuum pump of the shutter plate 34, and the communication port of the pressure balance valve 42 and the air passage 13 is arranged on the side away from the vacuum pump of the shutter plate 34. After the shutter plate 34 is inserted into the air passage 13 and the air passage 13 is closed, the air pressure detection valve 41 detects the air pressure in the air passage 13 in real time, and balances the air pressure in cooperation with the pressure balance valve 42, so as to avoid that the air pressure in the pipeline is too large to cause the shutter plate 34 to be unable to open.

[0023] As shown in Figure 5The heating device is arranged on the valve body base 11, and comprises a heating pipe 51 fixedly arranged in the valve body base 11 and annularly arranged outside the air passage 13.

[0024] The protective shell 12 is fixedly arranged on the valve body base 11, and the opening and closing driving mechanism and the opening and closing action mechanism are arranged in a cavity formed by the protective shell 12.

[0025] The utility model is described above by way of example, but the utility model is not limited to the above specific embodiments, and any modification or change based on the utility model belongs to the range required to be protected by the utility model.

Claims

1. An automatic gate valve to prevent gas backflow, characterized by, The valve body base (11) is provided with a ventilation pipeline (13), an opening and closing driving mechanism, an opening and closing action mechanism and a gas pressure balance mechanism, the opening and closing driving mechanism comprises a PLC control system and a driving cylinder (21), the opening and closing action mechanism comprises a gate (34) sliding along the valve body base (11), the PLC control system controls the driving cylinder (21) to drive the gate (34) to insert into the ventilation pipeline (13) along the radial direction and shut off the ventilation pipeline (13); the gas pressure balance mechanism comprises a pressure balance valve (42), and the pressure balance valve (42) is communicated with the ventilation pipeline (13).

2. A self-operated gate valve to prevent backflow of gas according to claim 1, characterized in that, The opening and closing driving mechanism further comprises a driving rack (22) and a driving gear (23), the driving rack (22) is fixedly connected with the piston rod of the driving cylinder (21), and the driving gear (23) is engaged with the driving rack (22); the opening and closing action mechanism further comprises a rotating arm (31), a connecting rod (32) and a sliding plate (33), one end of the rotating arm (31) is fixedly connected with the driving gear (23) in a coaxial manner, the connecting rod (32) is hingedly connected with the other end of the rotating arm (31) and the sliding plate (33) at two ends respectively, the sliding plate (33) slides along the valve body base (11), and the gate (34) is fixedly installed on the sliding plate (33).

3. A self-operated gate valve to prevent backflow of gas according to claim 2, characterized in that, The driving gear (23) is an incomplete gear, a part of the driving gear (23) without teeth is a limiting groove, a limiting block (24) is arranged in the limiting groove, and the limiting block (24) is fixedly connected with the valve body base (11).

4. A self-operated gate valve to prevent backflow of gas according to claim 2, wherein Longitudinal rollers (35) and transverse rollers (36) are rotatably arranged on the sliding plate (33), the longitudinal rollers (35) are symmetrically arranged on both sides of the sliding plate (33) and are arranged in a vertical direction, and the transverse rollers (36) are symmetrically arranged on both sides of the sliding plate (33) and are arranged in a horizontal direction.

5. A self-operated gate valve to prevent backflow of gas according to claim 1, wherein The heating device comprises a heating pipe (51), the heating pipe (51) is fixedly installed in the valve body base (11) and annularly arranged outside the ventilation pipeline (13).

6. A self-operated gate valve to prevent backflow of gas according to claim 1, characterized in that, The gas pressure balance mechanism further comprises a gas pressure detection valve (41), the gas pressure detection valve (41) is used to detect the gas pressure in the ventilation pipeline (13) on the side, away from the vacuum pump, of the gate (34), and the communication port of the pressure balance valve (42) with the ventilation pipeline (13) is arranged on the side, away from the vacuum pump, of the gate (34).

7. A self-operated gate valve to prevent backflow of gas according to claim 1, characterized in that, The protective shell (12) is fixedly installed on the valve body base (11), and the opening and closing driving mechanism and the opening and closing action mechanism are arranged in a cavity formed by the protective shell (12).

Images