JPH048897A - Dry vacuum pump utility abnormality detection method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a vacuum pump whose exhaust port is set to atmospheric pressure, and particularly relates to a utility abnormality detection method for a dry vacuum pump suitable as an exhaust pump for semiconductor manufacturing equipment. .

[Conventional technology]

An example of the configuration of a vacuum pump is shown in FIG. The vacuum pump body 1 is divided into a pump section 2 and a drive section 3, and the drive section generally uses an AC motor.

The pump section includes a rotating rotor and a stationary stator inside a casing 6 having an intake port 4 and an exhaust port 5, and compresses the gas sucked in from the intake port 4 and releases it from the exhaust port 5 under atmospheric pressure. discharge to. There is no liquid such as oil or water in the gas passage section of the pump section, and such a pump is generally called a dry vacuum pump. There are various types of pump parts, but the ones that are small and rotate at high speed include the turbo type and the screw type. Among these, the details of the turbo type are described in Japanese Patent Laid-Open No. 61-247893. Such dry vacuum pumps generally require a liquid such as water or oil, or a gas such as air or nitrogen as utilities for cooling and shaft sealing.

[Problem to be solved by the invention]

The above-mentioned conventional technology is a dry vacuum pump utility. If an abnormality occurs in liquids such as water or oil, or gases such as air or nitrogen, the dry vacuum pump is stopped immediately after the abnormality is detected, so dry vacuum pumps are manufactured using semiconductors. When used in equipment, for example, when detecting a decrease in the amount of cooling water, it is common for the amount of water to drop transiently. becomes. This resulted in interlayer points that caused significant damage to the semiconductors being manufactured.

An object of the present invention is to continue operating the pump during the pump utility abnormality tolerance period even if a utility abnormality occurs, thereby reducing stoppages due to pump utility abnormalities in a semiconductor manufacturing line as much as possible and improving the operating rate. The goal is to reliably detect utility abnormalities and reliably protect the vacuum pump.

[Means to solve the problem]

In order to achieve the above object, the present invention has two methods for detecting utility abnormality: one in which the vacuum pump is stopped immediately after an abnormality is detected, one in which the vacuum pump is stopped after an abnormality mask time, and one in which the vacuum pump is stopped even after an abnormality is detected. The case for continuing operation of the vacuum pump has been changed depending on the operation status of the vacuum pump.

[Effect]

During acceleration of the vacuum pump, utility abnormality detection immediately stops the vacuum pump after the abnormality occurs. In this case, the semiconductor manufacturing line using the vacuum pump is also preparing for operation, so immediately stopping the vacuum pump will not cause any damage to the semiconductor, and by stopping the vacuum pump immediately, the utility abnormality can be quickly recovered. Therefore, the operating rate of the semiconductor manufacturing line can be improved. Also,
It is possible to protect the vacuum pump from utility abnormalities.

During steady operation of the vacuum pump, if the abnormality continues even after the abnormality mask time has elapsed after the detection of the abnormality, the vacuum pump is stopped. In this case, utility abnormalities may become transient abnormalities for several seconds to several tens of seconds, but this is masked and is not considered an abnormality, so the vacuum pump does not stop frequently and the semiconductor damage can be minimized. In addition, the abnormality masking time is determined by the margin for the vacuum pump's utility, so even if the vacuum pump is stopped after the abnormality masking time has elapsed, the pump will not be damaged. It is possible to protect.

When the vacuum pump is decelerating, it is possible to improve the operating rate of the semiconductor manufacturing line and protect the vacuum pump by performing the same operation as when accelerating.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 4, the vacuum pump main body 1 consists of a pump section 2 and a drive section 3. The pump section 2 uses a mechanism provided inside the casing 2 to exhaust the gas sucked in through the intake port 4 to atmospheric pressure through the exhaust port 5. The mechanism provided inside the casing 2 described above is driven by the drive section 3. The drive unit 3 is electrically connected to a drive device [7, and the drive device 7 is connected to an AC power source 8. Utility liquid and gas are supplied to the vacuum pump main body 1 via a utility abnormality detection device 9. The utility abnormality signal from the utility abnormality detection device 9 is input to the drive unit [7], and if an abnormality occurs, the drive unit 7 stops the drive unit 3 built into the vacuum pump main body 1.

Referring to FIG. 2, a utility abnormality detection method according to the operating state of the vacuum pump 1 will be explained. There are four operating states of the vacuum pump 1: stopped, accelerated, and decelerated, and each state corresponds to acceleration, steady state, and deceleration in FIG. 2. While stopped, the drive section 3 is in a stopped state. During acceleration, the drive unit 3 starts rotating after the activation signal is turned on until it reaches the rated rotation speed. During steady state, the drive unit 3 is in a state from when it reaches the rated rotational speed until the stop signal is turned on. During deceleration, it is a state from when the stop signal is turned on until the drive unit 3 stops. In the utility abnormality detection method, detection 1 indicates that the vehicle is stopped, detection 2 indicates that the vehicle is accelerating or decelerating, and detection 3 indicates that the vehicle is stationary, and each will be explained below.

Detection 1 is a detection method in which when a utility abnormality is detected by the utility abnormality detection device [9, the drive device 7 ignores the utility abnormal signal, that is, masks all abnormal signals.

This is to prevent any abnormality from occurring in the utility from occurring as an abnormality since the utility is not required when the vacuum pump 1 is stopped.

Detection 2 will be explained with reference to FIG. Detection 2 is when the utility abnormality detection device @ 9 detects a utility abnormality while the vacuum pump 1 is accelerating or decelerating.
When the signal is input, the drive device 7 shifts the vacuum pump 1 from an acceleration state or a deceleration state to a deceleration state to stop the pump and protect from the utility abnormality. It is a method. This is because when the vacuum pump 1 is accelerating, the semiconductor manufacturing line using it is also preparing for operation, so it can be stopped immediately and recovery from a utility abnormality can be minimized.

Detection 3 will be explained with reference to FIG. The operation of detection 3 is divided into two depending on the time during which the utility abnormality is occurring. The first operation is when the utility abnormality continues for longer than the abnormality mask time opening t.
Stop the vacuum pump 1. The second operation is when the utility abnormality returns to normal within the abnormality mask time, that is, when the abnormality occurrence time t' is within the abnormality mask time. In this case, no abnormality is detected and the vacuum pump is turned off. Operation will continue. Here, the abnormal mask time can be set individually for each utility (water, water, air, nitrogen, etc.), and this allows the margin for each utility of the vacuum pump to be set, ensuring reliable protection of the vacuum pump. is possible. With this operation, even if a transient state of the utility is detected as an abnormality, the vacuum pump does not stop frequently, so that damage to semiconductors being manufactured can be minimized.

〔Effect of the invention〕

The present invention uses a method to stop the pump immediately after a utility abnormality is detected, a method to stop the pump after the abnormality mask time has elapsed, and a method to continue operating the pump even if an abnormality is detected, depending on the operating state of the vacuum pump. As a result, the pump can be reliably protected from utility abnormalities, and the usability of the pump can be improved when the pump is used in semiconductor manufacturing equipment or the like.

[Brief explanation of drawings]

FIG. 1 is a timing chart of one embodiment of the present invention, FIGS. 2 and 3 are timing charts showing details thereof,
FIG. 4 is a block diagram of the vacuum pump. 1 ・Vacuum pump, 2... Pump section, 3 Drive section, 4
...Intake port, 5..Exhaust port, 7..Drive device, 8..AC No.! Figure 'JA3 Figure

Claims (1)

[Claims] 1. Consists of a stator fixed within a casing having an intake port and an exhaust port, and a drive shaft rotatably supported within the casing, the drive shaft being driven by an AC motor; The gas sucked in from the intake port is transferred from the exhaust port,
A dry vacuum pump that directly exhausts air to the atmosphere has a means for detecting an abnormality in liquid and gas, which is a utility necessary for the operation of the dry vacuum pump, and after detecting an abnormality, immediately makes an abnormality judgment and restarts the dry vacuum pump. The operation of the dry vacuum pump is divided into two cases: stopping the dry vacuum pump after the abnormality mask time has elapsed, determining an abnormality and stopping the dry vacuum pump, and continuing to operate the dry vacuum pump even if an abnormality is detected. A utility abnormality detection method for dry vacuum pumps that is characterized by being used differently depending on the situation.