JPH06221273A - Compressor - Google Patents

Abstract

PURPOSE:To provide a compressor which can suitably judge whether an auxiliary tank is connected or not and improve operation efficiency by suitably selecting pressure switch type or automatic unloader type in the case of performing automatic switch operation. CONSTITUTION:This compressor is provided with a control part 10 for measuring pressure change data according to the pressure data of a pressure sensor 6, operating the ratio of pressure change data when the pressure is increased to the pressure change data when the pressure is decreased according to the pressure change data, and judging whether an auxiliary tank 4 is connected to a main tank 3 according to the relation of the arithmetic result to the pressure change data. The quantity of compressed air used can be known by taking the ratio of the pressure change between pressure increase and decrease, and the existence of the auxiliary tank 4 connected to the main tank 3 is judged according to such characteristics that the larger the storage capacity is, the smaller the pressure change both in the pressure increase and the pressure decrease is, and the operation mode is suitably selected to improve operation efficiency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor for compressing a gas such as air.

[0002]

2. Description of the Related Art Conventionally, a compressor for compressing a gas such as air is operated by a pressure switch type, an automatic unloader type, or an automatic switching type. With the pressure switch type, when the internal pressure of the storage tank reaches the maximum pressure, the electric motor that drives the compressor main body is stopped, and the internal pressure of the storage tank decreases due to consumption of compressed gas, and when the internal pressure reaches the minimum pressure, the electric motor is turned on. This is an operation method of restarting and maintaining the internal pressure of the storage tank within a predetermined range. In addition, the automatic unloader type is the minimum pressure when the internal pressure of the storage tank reaches the maximum pressure and the suction valve is always opened to operate the motor without load (operation that rotates the motor without performing compression). At this time, the suction valve is closed and the compression operation is performed again to maintain the pressure within a certain range. In this method, the compression operation can be started quickly. In this case, the pressure switch type is often used when the consumption of compressed air is small, and the automatic unloader type is often used when the consumption of compressed air is large.

On the other hand, the automatic switching system is a system for performing compression operation by selecting the pressure switch system or the automatic unloader system based on the rise time of the internal pressure of the storage tank, etc., and the amount of compressed air consumed is large. The pressure switch type or the automatic unloader type can be selected in accordance with the above, and compressed gas can be obtained more efficiently than in the case of any one of the above-described individual operations.

Further, conventionally, there is a case in which an auxiliary tank is connected to a storage tank provided in a compressor so that the storage volume is increased and a stable compressed gas is stably supplied.

[0005]

By the way, when the volume is increased as described above, the amount of compressed air used is
Even if it is the same as the case where the auxiliary tank is not connected, the pressure change varies depending on whether the auxiliary tank is connected, that is, the size of the storage volume. Therefore, for example, in the above-described automatic unloader type compressor, there is a risk that the pressure switch type and the automatic unloader type are erroneously selected, and efficient operation is hindered.

The present invention has been made in view of the above circumstances, and it is possible to appropriately determine whether or not the auxiliary tank is connected, and in the case of performing automatic switching operation, a pressure switch type,
An object of the present invention is to provide a compressor capable of improving operating efficiency by appropriately selecting an automatic unloader type.

[0007]

According to a first aspect of the present invention, in order to achieve the above object, in a compressor for storing compressed gas obtained by operation of a compressor body in a main tank, the pressure in the main tank is reduced. And a pressure change data measuring means for measuring pressure change data showing a change relationship of pressure with time based on the pressure data of the pressure detecting means, and the pressure change data. Calculating means for calculating the ratio of the pressure change data when the pressure rises and the pressure change data when the pressure drops, based on the pressure change data of the measuring means; and the calculation result of the calculating means and the pressure change of the pressure change data measuring means. It is characterized by further comprising: a determination means for determining the presence or absence of the auxiliary tank connected to the main tank based on the relationship with the data.

In order to achieve the above object, the invention of claim 2 stores compressed gas obtained by the operation of the compressor body in a main tank, and outputs the compressed gas from a pressure detecting means for detecting the pressure in the main tank. Pressure data reaches the upper limit pressure,
It is possible to select either a pressure switch type operation method that stops the electric motor that operates the compressor body or an automatic unloader type operation method that operates the compressor body without a load without stopping the electric motor. In the compressor, the pressure change data measuring means for measuring the pressure change data showing the relationship of the change of the pressure with time based on the pressure data of the pressure detecting means, and the pressure change data of the pressure change data measuring means Based on the relation between the calculation means for calculating the ratio of the pressure change data when the pressure rises and the pressure change data when the pressure drops, and the relation between the calculation result of the calculation means and the pressure change data of the pressure change data measuring means, An operation method setting means for selecting and setting one of the pressure switch operation method and the automatic unloader operation method is provided. And butterflies.

In order to achieve the above object, the invention according to claim 3 stores compressed gas obtained by the operation of the compressor body in a main tank, and outputs the compressed gas from a pressure detecting means for detecting the pressure in the main tank. Pressure data reaches the upper limit pressure,
It is possible to select either a pressure switch type operation method that stops the electric motor that operates the compressor body or an automatic unloader type operation method that operates the compressor body without a load without stopping the electric motor. In the compressor, the pressure change data measuring means for measuring the pressure change data showing the relationship of the change of the pressure with time based on the pressure data of the pressure detecting means, and the pressure change data of the pressure change data measuring means Based on the relation between the calculation means for calculating the ratio of the pressure change data when the pressure rises and the pressure change data when the pressure drops, and the relation between the calculation result of the calculation means and the pressure change data of the pressure change data measuring means, Tank volume calculation means for calculating the tank volumes of the main tank and the auxiliary tank connected thereto, the calculation result of the tank volume calculation means, and the calculation An operating method setting means for selecting and setting one of the pressure switch type operating method and the automatic unloader type operating method based on the relationship with the stage calculation result. .

[0010]

[Function] The internal pressure of the main tank rises to the amount obtained by subtracting the amount of compressed air used from the amount of compressed air generated in the compressor body, while it drops to the amount of compressed air used. By taking the ratio, the amount of compressed air used can be known. Further, when the storage volume is large, both the pressure increase and the pressure decrease in pressure change are smaller than when the storage volume is small. On the basis of such characteristics, the invention of claim 1 obtains the ratio of the pressure change data at the time of pressure increase and the pressure change data at the time of pressure decrease by the calculating means, and the judging means determines the ratio and the pressure change. The presence or absence of an auxiliary tank connected to the main tank is determined based on the relationship with the data.

According to the second aspect of the present invention, the ratio of the pressure change data at the time of pressure increase and the pressure change data at the time of pressure decrease is obtained by the calculating means, and the operation system setting means is based on the relationship between the ratio and the pressure change data. Select either the pressure switch type operating system or the automatic unloader type operating system to set the appropriate operating system.

According to the third aspect of the present invention, the ratio of the pressure change data when the pressure increases and the pressure change data when the pressure decreases is calculated by the calculating means, and the relationship between the ratio and the pressure change data is calculated by the tank volume calculating means. Based on the above, the tank volume is calculated, and the operation method setting means selects one of the pressure switch type operation method and the automatic unloader operation method based on the relationship between the ratio and the tank volume to select an appropriate operation method. Set.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In the figure, 1 is a reciprocating compressor body for compressing air, 2 is an electric motor for driving the compressor body 1, and 3 is a main tank 3 having a volume V ₀ for storing compressed air from the compressor body 1. , The main tank 3 has auxiliary tanks of various volumes (here, the volumes are V ₁ and V, respectively).
_Two auxiliary tanks of ₂ and V ₃ (V ₁ > V ₂ > V ₃ ) are taken as an example. ) 4 can be connected.

A controller 5 is provided by connecting an electric motor 2 and a suction valve (not shown) of the compressor main body 1 to an unloader drive section (not shown) that constantly opens the valve to bring it into an unloading state. The controller 5 detects the pressure in the main tank 3 and outputs pressure data, as a pressure sensor 6, a manipulation display unit 7 including a manipulation button and a pressure indicator, a memory 8, and a T ₁ timer. , T ₂ timer, T ₃
The timer 9 is composed of a timer, and a control unit 10 that executes a preset program to perform processing as described below and controls each unit based on the processing result. The pressure sensor 6 extends into the main tank 3 and detects the pressure in the main tank 3.

Next, with reference to FIGS. 2 to 5, the operation of the compressor and the contents of control by the controller 5 will be described. In this compressor, when the electric motor 2 is started by the operation of the operation display unit 7, the unloader drive unit is once actuated, and the unloader drive unit is not operated after the loadless operation with the suction valve always opened. As a working state, the compressor body 1 generates compressed air in a state where the suction valve can be opened and closed, and this compressed air is stored in the main tank 3, whereby the pressure in the main tank 3 rises. Control unit 10, based on the pressure data from the pressure sensor 6, the current pressure P in the main tank 3 is determined whether reaches the lower limit pressure P _A in FIG. 3 (step S1), the current pressure P is the lower limit pressure From the point of time when P _A is reached, the T ₁ timer and T ₃ timer of timer 9 are cleared and started to start time counting (step S2).

The current pressure P in the main tank 3 rises, and as shown in FIG.
It has reached the reference pressure Pr when the control unit 10 determines (step S3), and to stop the T ₁ Timer 9, and stores the measured time T ₁ to the memory 8 as a pressure change data (step S4). Further, when the control unit 10 determines that the current pressure P has risen to reach the upper limit pressure P _B of FIG. 3 (step S5), the compression operation of the compressor is stopped (step S6). In this case, if the automatic unloading operation is being performed, the unloader driving unit is in an operating state to perform no-load operation, and if the pressure switch operation is being performed, the electric motor 2 is stopped. It should be noted that whether to operate by the automatic unloader type or the pressure switch type is determined by the method described later, but it cannot be determined by the method described later when the compression operation is stopped for the first time. You should select it.

When the compression operation is stopped, the pressure in the main tank 3 decreases due to the consumption of compressed air, but the control unit 10 determines whether the current pressure P in the main tank 3 has decreased to the reference pressure Pr. It is judged (step S7) that the current pressure P
When the pressure reaches the reference pressure Pr, the T ₂ timer of the timer 9 is cleared and started to start time measurement (step S
8).

When the control unit 10 determines that the present pressure P in the main tank 3 has further decreased and reached the lower limit pressure P _A (step S9), the T ₂ timer and the T ₃ timer of the timer 9 are stopped, and The measured times T ₂ and T ₃ are stored in the memory 8 as pressure change data (step S10), and the unloader drive unit is deactivated or the electric motor 2 is activated to restart the compression operation (step S11).

By the way, assuming that the amount of air produced by the compressor body 1 is Q and the amount of air used is Q _EU , the pressure in the main tank 3 during the compression operation increases to Q-Q _EU = ΔQ. When the amount of used air Q _EU is small, the pressure increase becomes large, while when the used amount of air Q _EU is large, the pressure increase becomes small. In addition, the main tank 3 that is not in compression operation
Since the internal pressure drops to Q _EU , if the used air amount Q _EU is small, the pressure drop becomes small, whereas if the used air amount Q _EU is large, the pressure drop becomes large.

When the auxiliary tank 4 is connected,
Compared to the case where the storage volume is not connected, the pressure increase decreases as the storage volume increases, but the pressure drop also decreases.

Therefore, when the ratio of the time T _{1 of} pressure rise to the time T _{2 of} pressure drop is T ₂ / T ₁ = K and the variable K is a dimensionless variable, the variable K is used. Air volume Q
It depends on the _EU , but is not affected by the presence or absence of auxiliary tanks. That is, the amount of used air Q _EU can be known by obtaining the variable K.

Next, assuming that the variable K is constant, that is, the amount of used air Q is constant, when the auxiliary tank 4 is connected, the storage volume increases as compared with the case where the auxiliary tank 4 is not connected. Accordingly, the times T ₁ , T ₂ and T ₃ all become longer. Then, the times T ₁ , T ₂ and T ₃ become longer as the volume of the auxiliary tank 4 increases. Therefore, the times T ₁ , T ₂ and T ₃ will change depending on the total volume of the main tank 3 and the auxiliary tank 4.

Therefore, the variable K and the times T ₁ , T ₂
It is possible to know the total volume of the main tank 3 and the auxiliary tank 4, by extension, the presence or absence of the auxiliary tank 4 and the size (volume) of the auxiliary tank 4 by looking at the relationship with any one of T ₃ and T ₃ .

An example of a map for obtaining the volumes of the main tank 3 and the auxiliary tank 4 based on the relationship between the variable K and the pressure drop time T ₂ based on the above knowledge is shown in FIG. In FIG. 4, if the variable K = 2.5, the pressure drop time T ₂ is T
_{In the case of 2A,} the main tank 3 alone is not provided with the auxiliary tank 4, and in the case of T _2B , the auxiliary tank 4 of the volume V ₁ is connected. Similarly, in the case of T _2C and T _2D , the volume V _{2 is the same.} , V ₃ auxiliary tank 4 is connected.

FIG. 5 shows an example of a map for selecting either the automatic unloader type or the pressure switch type operating mode from the relationship between the variable K and the pressure drop time T ₂ .
The map in FIG. 5 sets the operation method depending on whether the intersection of the variable K and the pressure drop time T ₂ is in the automatic unloader type region or the pressure switch type region. The smaller the air quantity Q _EU is, the larger the pressure change becomes. Therefore, the storage volumes of the main tank 3 and the auxiliary tank 4 become larger as the automatic unloader type is used and the longer the pressure drop time T ₂ is. Since the change in pressure is small, the pressure switch type is set.

The maps of FIGS. 4 and 5 are stored in the memory 8. The control unit 10 executes step S11 in FIG.
After the compression operation is restarted, the variable K is obtained from the time counts T ₁ and T ₂ stored in the memory 8 (step S12). Based on the map of FIG. 4, determination of the presence or absence of the auxiliary tank 4 and the volume of the auxiliary tank 4 are calculated from the variable K and the time count T _2, and the results are displayed on the display unit of the operation display unit 7 of FIG. Yes (step S13). Similarly, variable K and time T
_The operation method is determined based on the map of FIG. 5 according to ₂ (step S14), and the pressure switch type operation method is set (step S15) or the automatic unloader type operation method is set (step S16).

When the operation system is set in this way, the processing from step S1 onward is repeated, and when the compression operation is stopped in step S6, the unloader drive section is operated or the electric motor 2 is operated according to the set operation system. Stop.

With the above-described structure, the pressure switch type or the automatic unloader type can be selected according to the determination result depending on the storage volume, that is, whether the auxiliary tank 4 is connected or not, and the operation efficiency can be improved. You will be able to improve.

In the above embodiment, the auxiliary tank 4
If it is not necessary to display the presence / absence and / or the volume of the auxiliary tank 4 on the operation display unit 7, the tank volume determination / display process of step S13 can be omitted. Further, when the operation system is not the automatic switching system but only one of the pressure switch system and the automatic unloader system is operated, or the operating system is manually switched, the steps S14 to S16 are performed. The processing may be omitted.

Further, in the maps of FIGS. 4 and 5,
And to perform the tank volume determination and operating mode determined by the relationship between the time T ₂ of the variable K and pressure drop, but not limited thereto, and the time T ₃ from time T ₁ or pressure increase in the pressure rise to a pressure drop The maps of FIGS. 4 and 5 may be created based on the relationship with the variable K. Further, as the variable K, T ₂ / T is calculated by the time T _{1 of} pressure increase and the time T ₂ of pressure decrease thereafter.
Although T ₁ = K is set, conversely, T ₁ / T ₂ = K may be set to obtain the ratio of both, and further, the pressure drop time T ₂ shown in FIG. 3 and the subsequent pressure rise. Time T
_It is also possible to set T ₂ / T ₁ ′ = K depending on ₁ ′. In this case, instead of time T ₃ , T ₂ + T ₁ ′ = T ₄
The maps of FIGS. 4 and 5 may be created based on the relationship between the time T ₄ and the variable K (= T ₂ / T ₁ ′).

Further, the time T _{1 of} pressure rise and the time T _{2 of} pressure drop are measured between the lower limit pressure P _A and the reference pressure Pr, but the time is not limited to this, and the reference pressure Pr and the upper limit pressure P _B The pressure may be set between the lower limit pressure P _A and the upper limit pressure P _B as long as it is between the lower limit pressure P _A and the upper limit pressure P _B.

In each of the above-mentioned embodiments, the time until a predetermined pressure change occurs was obtained, but the present invention is not limited to this.
For example, the pressure change amount ΔP per unit time is obtained, and the pressure change amount ΔP ₁ when the pressure rises and the pressure change amount ΔP when the pressure falls.
_From the relationship with ₂ , the variable K'is defined as ΔP ₂ / ΔP ₁ = K '.
Is calculated, and this variable K ′ and the pressure change amount ΔP ₁ or ΔP ₂
The maps of FIGS. 4 and 5 may be created according to the relationship with.

Since the times T _{1 to} T ₄ and T ₁ ′ and the pressure change amounts ΔP ₁ and ΔP ₂ described above all show the relationship of the change of pressure with time, they are referred to in the present specification. Are collectively called pressure change data.

In the map of FIG. 5, the variable K
The operation method is determined from the relationship between (K ') and the pressure change data. In this case, the pressure change data is used as a factor of the storage volume of the air tank as described above, so the pressure change data is used. Instead of step S
The map of FIG. 5 is created from the tank volume (total volume of the main tank 3 and the auxiliary tank 4 or the volume of the auxiliary tank 4 only) calculated by 13 and the variable K (K '), and based on this, steps S14 to S14 are executed. You may make it perform the selection setting of the driving system of S16.

Further, as another modified example, the pressure detection at the time of the pressure increase and the pressure decrease is performed twice or more,
On the condition that the same comparison data is continuously obtained, it is judged whether the auxiliary tank 4 is connected or not, or the pressure detection at the time of pressure increase and pressure decrease is performed twice or more, and the average value is obtained. The data may be obtained based on the data, and the presence or absence of the connection of the auxiliary tank 4 may be determined based on the data. This makes it possible to more accurately determine whether or not the auxiliary tank 4 is connected, even when the amount of compressed air used suddenly changes.

Further, in the present embodiment, the reciprocating type compressor is taken as an example, but the present invention is not limited to this, and may be, for example, a scroll type or screw type rotary compressor. . Then, in this case, the automatic unloader type operation refers to a state in which intake air from the outside is eliminated by the adjusting valve provided on the intake side of the compressor.

[0037]

Since the present invention is the compressor configured as described above, it is based on the relationship between the pressure change data and the ratio of the pressure change data when the pressure rises and the pressure change data when the pressure drops. The presence or absence of an auxiliary tank connected to the main tank can be determined, and in the same way, in the case of the automatic switching type, depending on the presence or absence of the connection of the auxiliary tank, the pressure switch type or automatic unloader type operation system can be selected. Appropriate selection can be made, which can improve the operating efficiency.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a compressor according to an embodiment of the present invention.

FIG. 2 is a diagram showing a control mechanism of a control unit 10 in the compressor shown in FIG.

FIG. 3 is a characteristic diagram showing the relationship between the pressure of the main tank 3 and time during operation of the compressor.

FIG. 4 is a diagram showing a map for obtaining a tank volume from a relationship between a variable K and a pressure drop time T ₂ .

FIG. 5 is a diagram showing a map for selecting an operation method based on a relationship between a variable K and a pressure drop time T ₂ .

[Explanation of symbols]

 1 Compressor body 3 Main tank 4 Auxiliary tank 5 Controller 6 Pressure sensor (pressure detection means) 7 Operation display section 8 Memory 9 Timer 10 Control section

Claims (3)

[Claims] 1. A compressor for storing a compressed gas obtained by operating a compressor body in a main tank, the pressure detecting means detecting pressure in the main tank and outputting pressure data,
Pressure change data measuring means for measuring pressure change data showing a relationship of change of pressure with time based on the pressure data of the pressure detecting means, and pressure at the time of pressure increase based on the pressure change data of the pressure change data measuring means. It is connected to the main tank based on the calculation means for calculating the ratio between the change data and the pressure change data at the time of pressure drop, and the relation between the calculation result of the calculation means and the pressure change data of the pressure change data measuring means. A compressor comprising: a determination unit that determines the presence or absence of an auxiliary tank. 2. When the compressed gas obtained by the operation of the compressor main body is stored in the main tank and the pressure data output from the pressure detecting means for detecting the pressure in the main tank reaches the upper limit pressure, It is possible to select either a pressure switch type operation method that stops the electric motor that operates the compressor main body or an automatic unloader type operation method that operates the compressor main body without a load without stopping the electric motor. In the compressed compressor, based on the pressure data of the pressure detecting means,
Pressure change data measuring means for measuring pressure change data showing a relationship of change of pressure with time, and pressure change data when pressure rises and pressure change data when pressure drops based on the pressure change data of the pressure change data measuring means. Of the pressure switch type operating system and the automatic unloader type operating system based on the relationship between the calculating means for calculating the ratio of the pressure change data measuring means and the pressure change data of the pressure change data measuring means. And a driving method setting means for selecting and setting one of the driving methods. 3. The compressed gas obtained by the operation of the compressor main body is stored in a main tank, and when the pressure data output from the pressure detection means for detecting the pressure in the main tank reaches the upper limit pressure, It is possible to select either a pressure switch type operation method that stops the electric motor that operates the compressor main body or an automatic unloader type operation method that operates the compressor main body without a load without stopping the electric motor. In the compressed compressor, based on the pressure data of the pressure detecting means,
Pressure change data measuring means for measuring pressure change data showing a relationship of change of pressure with time, and pressure change data when pressure rises and pressure change data when pressure drops based on the pressure change data of the pressure change data measuring means. And the tank volume of the main tank and the auxiliary tank connected thereto based on the relationship between the calculation means for calculating the ratio and the calculation result of the calculation means and the pressure change data of the pressure change data measuring means. Based on the relationship between the tank volume calculation means and the calculation result of the tank volume calculation means and the calculation result of the calculation means, one of the pressure switch type operation method and the automatic unloader type operation method is selected. And a driving system setting means for setting the compressor.