JP3141220B2 - Compressor - Google Patents

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 any one of a pressure switch type, an automatic unloader type and an automatic switching type. With the pressure switch type, when the internal pressure of the storage tank reaches the maximum pressure, the motor that drives the compressor body is stopped, and the internal pressure of the storage tank decreases due to the consumption of compressed gas. This is an operation method in which the internal pressure of the storage tank is maintained within a predetermined range by restarting. In the automatic unloader type, when the internal pressure of the storage tank reaches the maximum pressure, the suction valve is always opened to operate the motor without load (operation for rotating the motor without performing compression), and the pressure becomes the minimum pressure. This is an operation method in which the suction valve is sometimes 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 used when the consumption of compressed air is large.

On the other hand, the automatic switching type is a type in which the pressure switch type or the automatic unloader type is selected based on the rise time of the internal pressure of the storage tank or the like to perform a compression operation. The pressure switch type and the automatic unloader type can be selected according to the above conditions, so that compressed gas can be obtained more efficiently as compared with the independent operation of any of the above types.

[0004] Conventionally, there is a case where an auxiliary tank is connected to a storage tank provided in a compressor so as to increase the storage volume and stably supply a stable compressed gas.

[0005]

When the volume is increased as described above, the amount of compressed air used is
Even if it is the same as when the auxiliary tank is not connected, the pressure change differs depending on whether the auxiliary tank is connected, that is, depending on the size of the storage volume. For this reason, for example, in the automatic unloader type compressor described above, there is a possibility that the pressure switch type or the automatic unloader type is 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 an auxiliary tank is connected. In addition, when performing an automatic switching type operation, a pressure switch type,
It is an object of the present invention to provide a compressor capable of improving operation efficiency by appropriately selecting an automatic unloader type.

[0007]

According to the first aspect of the present invention, there is provided a compressor for storing compressed gas obtained by operating a compressor body in a main tank. Pressure detection means for detecting pressure change, and outputting pressure data; pressure change data measurement means for measuring pressure change data indicating a relation of change of pressure with respect to time based on the pressure data of the pressure detection means; Calculating means for calculating the ratio between the pressure change data at the time of pressure rise and the pressure change data at the time of pressure drop 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. Determining means for determining the presence or absence of an auxiliary tank connected to the main tank based on a relationship with the data.

According to a second aspect of the present invention, in order to achieve the above object, compressed gas obtained by operating a compressor body is stored in a main tank, and is output from a pressure detecting means for detecting a pressure in the main tank. When the pressure data reaches the upper pressure limit,
It is possible to select either a pressure switch type operation method in which the motor that operates the compressor body is stopped or an automatic unloader type operation method in which the compressor body is operated without load without stopping the motor. A pressure change data measuring means for measuring pressure change data indicating a relation of a change in pressure with respect to time based on the pressure data of the pressure detecting means, and a pressure change data of the pressure change data measuring means. Based on the calculation means for calculating the ratio between the pressure change data at the time of pressure rise and the pressure change data at the time of pressure drop, based on the relationship between the calculation result of the calculation means and the pressure change data of the pressure change data measurement means, Tank volume calculating means for calculating a tank volume of the main tank and an auxiliary tank connected thereto; a calculation result of the tank volume calculating means; Operating method setting means for selecting and setting any one of the pressure switch-type operation method and the automatic unloader-type operation method based on the relationship with the calculation result of the stage. .

[0009]

[Function] The internal pressure of the main tank rises by the amount obtained by subtracting the amount of compressed air used from the amount of compressed air generated by the compressor body, while it drops by 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 change of the pressure rise and the pressure change of the pressure drop are small as compared with the case where the storage volume is small. According to the first aspect of the present invention, the ratio between the pressure change data at the time of pressure increase and the pressure change data at the time of pressure drop is determined by the calculating means, and the determining 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 between the pressure change data at the time of pressure rise and the pressure change data at the time of pressure drop 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 relationship between the ratio and the tank volume, the operating mode setting means selects one of the pressure switch type operating mode and the automatic unloader operating mode to select an appropriate operating mode. Set.

[0011]

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

A controller 5 is connected to an electric motor 2 and an unloader driving unit (not shown) that normally opens a suction valve (not shown) of the compressor body 1 to open the unload state. The controller 5 detects the pressure of the main tank 3 and the pressure sensor 6 as a pressure detecting means for outputting a pressure data, an operation display unit 7 consisting of operation buttons and a pressure indicator or the like, a memory 8, T ₁ timer , T ₂ timer, T ₃
It is roughly composed of a timer 9 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 a pressure in the main tank 3.

Next, the operation of the compressor and the contents of control by the controller 5 will be described with reference to FIGS. In this compressor, when the electric motor 2 is started by the operation of the operation display unit 7, the unloader driving unit is once operated to start the operation with the suction valve always open and no load operation. The compressor body 1 generates compressed air in a state where the suction valve can be opened and closed as an operation state, and the compressed air is stored in the main tank 3, whereby the pressure in the main tank 3 increases. 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 Start timing is started from the time it reaches the P _a clear the T ₁ timer and T ₃ timer 9 (step S2).

The current pressure P in the main tank 3 rises, and 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, if the current pressure P is set to the control unit 10 reaches the upper limit pressure P _B in FIG. 3 is determined increases (step S5), and stops the compression operation of the compressor (step S6). In this case, if the operation is in the automatic unloading type, the unloader driving unit is operated to perform no-load operation, and if the operation is in the pressure switch type, the electric motor 2 is stopped. Whether the operation is performed by the automatic unloader type or the pressure switch type is determined by a method described later. What is necessary is just to select it.

When the compression operation stops, the pressure in the main tank 3 decreases due to the consumption of the compressed air. However, the control unit 10 determines whether the current pressure P in the main tank 3 has decreased to the reference pressure Pr. Is determined (step S7), the current pressure P
There Start timing is started from the time it reaches the reference pressure Pr clears the T ₂ Timer 9 (step S
8).

Furthermore decreases the current pressure P in the main tank 3, the control unit 10 and reaches the lower limit pressure P _A is determined (step S9), and to stop the T ₂ timer and T ₃ Timer 9, this the measured time T _2, T ₃ are stored in the memory 8 as a pressure change data (step S10), and restarts the compression operation start or the electric motor 2 and a non-operating state unloader driver (step S11).

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 rises to Q−Q _EU = ΔQ. When the amount of used air _QEU is small, the pressure rise is large, while when the amount of used air _QEU is large, the pressure rise is small. In addition, the main tank 3 during the compression operation stop
The pressure of the inner Since the Q _EU addressed drops, the small amount of air Q _EU using, while the pressure drop is small and an air quantity Q _EU that is often used, the pressure drop increases.

When the auxiliary tank 4 is connected,
As the storage volume increases, the pressure rise decreases as compared with the case where the connection is not made, but the pressure drop also decreases.

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

Next, assuming that the variable K is fixed, that is, the amount of used air Q is fixed, when the auxiliary tank 4 is connected, the storage volume increases when compared with the case where the auxiliary tank 4 is not connected. , The times T ₁ , T ₂ and T ₃ all become longer. 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 vary 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
And by viewing any one relationship T _3, it is possible to know the main tank 3 and the total volume and hence the presence and magnitude of the auxiliary tank 4 of the auxiliary tank 4 of the auxiliary tank 4 (volume).

FIG. 4 shows an example of a map for obtaining the volumes of the main tank 3 and the auxiliary tank 4 from the relationship between the variable K and the pressure drop time T ₂ based on the above knowledge. In FIG. 4, if the variable K = 2.5, the time T _{2 of the} pressure drop is T
_2A is a state where the primary tank 3 only in the auxiliary tank 4 is not provided when the a state in which the auxiliary tank 4 volume V ₁ is connected at the time of T _2B, likewise T _2C, the volume V ₂ when the T _2D , it is seen that the auxiliary tank 4 V ₃ is in a state of being connected.

FIG. 5 shows an example of a map for selecting one of the automatic unloader type and pressure switch type operation modes based on the relationship between the variable K and the pressure drop time T ₂ .
The map of FIG. 5 sets the operation mode depending on whether the intersection of the variable K and the pressure drop time T ₂ is in the automatic unloader type area or the pressure switch type area. smaller, since the working air rate Q _EU is much pressure change becomes large, so that the automatic unloader type, also, as the time T ₂ of the pressure drop becomes long, large storage capacity of the main tank 3 and the auxiliary tank 4 is Since the pressure change is small, the pressure switch type is set.

The maps shown in FIGS. 4 and 5 are stored in the memory 8. The control unit 10 determines in step S11 in FIG.
After the compression operation resumed, obtaining the variable K than counting are stored in the memory 8 times T ₁ and T ₂ (step S12). Based on the variable K and the measured time T ₂ , the presence or absence of the auxiliary tank 4 and the volume of the auxiliary tank 4 are calculated based on the map of FIG. 4, and the results are displayed on the display of the operation display unit 7 of FIG. (Step S13). Similarly, the variable K and the time T
_Then, the operation method is determined based on the map shown in FIG. 5 (step S14), and the operation method of the pressure switch type is set (step S15) or the operation method of the automatic unloader type is set (step S16).

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

With the above-described configuration, the pressure switch type or the automatic unloader type can be selected according to the determination result according to the storage volume, that is, whether the auxiliary tank 4 is connected or not, and the operating efficiency can be reduced. Improvement can be achieved.

In the above embodiment, the auxiliary tank 4
If there is no need to display the presence / absence and / or the volume of the auxiliary tank 4 on the operation display unit 7, the processing of tank volume determination / display in step S13 can be omitted. When the operation mode is not the automatic switching mode, but is operated by only one of the pressure switch type or the automatic unloader mode, or when the operation mode 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 4 and 5 may be created based on the relationship with the variable K. Further, as a variable K, T by a time T ₂ of the subsequent pressure drop with time T ₁ of the pressure increase ₂ /
Although T ₁ = K, the ratio between T ₂ and T ₁ / T ₂ may be calculated as T ₁ / T ₂ = K, and the time T _{2 of the} pressure drop shown in FIG. Time T
_It is also possible to set T ₂ / T ₁ '= K with ₁ '. In this case, instead of time T ₃ , T ₂ + T ₁ ′ = T ₄ ,
The relationship between the time T ₄ with the variable _{K (= T 2 / T 1} ') may create a map of FIGS.

Further, the time T ₂ of the times T ₁ and pressure drop in the pressure rise was timed with the lower limit pressure P _A and the reference pressure Pr, is not limited thereto, the reference pressure Pr and the upper limit pressure P _B it may be between, short if between the lower limit pressure P _a and the upper limit pressure P _B, may be set so as to measure the pressure value between two arbitrary points.

In each of the above embodiments, the time until a predetermined pressure change occurs is obtained. However, 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
₂ and ΔP ₂ / ΔP ₁ = K ′ and the variable K ′
Is calculated, and the variable K ′ and the pressure change amount ΔP ₁ or ΔP ₂
4 and 5 may be created based on the relationship between

The times T _{1 to} T ₄ , T ₁ ′ and the pressure changes ΔP ₁ , ΔP ₂ described above indicate the relationship of the pressure with respect to time. Are collectively called pressure change data.

Further, in the map of FIG.
The operation method is determined from the relationship between (K ') and the pressure change data. In this case, since the pressure change data is used as a factor of the storage volume of the air tank as described above, the pressure change data is determined. Instead of step S
The map shown in FIG. 5 is created based on the tank volume (total volume of the main tank 3 and the auxiliary tank 4 or the volume of only the auxiliary tank 4) calculated by step 13 and the variable K (K '). The selection of the operation mode in S16 may be performed.

Further, as another modified example, the pressure detection at the time of the pressure rise and the pressure drop is performed twice or more,
On the condition that the same comparison data is obtained continuously, it is determined whether or not the auxiliary tank 4 is connected, or the pressure is detected twice or more when the pressure is increased and when the pressure is decreased. It may be configured to obtain data based on the information and determine whether or not the auxiliary tank 4 is connected based on the data. This makes it possible to more accurately determine whether or not the auxiliary tank 4 is connected even if the amount of compressed air used suddenly changes.

Further, in this embodiment, a reciprocating compressor is taken as an example. However, the present invention is not limited to this, and a rotary compressor such as a scroll type or a screw type may be used. . In this case, the automatic unloader operation refers to a state in which an external suction air is eliminated by an adjustment valve provided on a suction side of the compressor.

[0035]

Since the present invention is a compressor configured as described above, it is based on the ratio of the pressure change data at the time of pressure increase to the pressure change data at the time of pressure drop and the relationship between the pressure change data and the pressure change data. Therefore, the presence or absence of an auxiliary tank connected to the main tank can be determined.Similarly, in the case of the automatic switching type, the operation method of the pressure switch type and the automatic unloader type according to the presence or absence of the auxiliary tank connection An appropriate selection can be made, thereby improving operation efficiency.

[Brief description of the drawings]

FIG. 1 is a view 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 of FIG.

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

It is a diagram of a map for obtaining a tank volume from the relationship between FIG. 4 variables K and a pressure drop time T _2.

5 is a diagram showing a map for selecting the operating mode from the relationship between the variables K and a pressure drop time T _2.

[Explanation of symbols]

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

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F04B 49/02 F04B 49/06

Claims (2)

(57) [Claims] 1. A compressor for storing compressed gas obtained by an operation of a compressor body in a main tank, a pressure detecting means for detecting pressure in the main tank and outputting pressure data,
A pressure change data measuring means for measuring pressure change data indicating a relationship of a change in pressure with respect to time based on the pressure data of the pressure detecting means; and a pressure at the time of pressure increase based on the pressure change data of the pressure change data measuring means. Calculating means for calculating a ratio between the change data and the pressure change data at the time of pressure drop; and a connection to the main tank based on a relationship between the calculation result of the calculating means and the pressure change data of the pressure change data measuring means. A compressor for determining whether an auxiliary tank is provided. 2. When the compressed gas obtained by the operation of the compressor body is stored in a main tank and pressure data output from pressure detecting means for detecting the pressure in the main tank reaches an upper limit pressure, It is possible to select either a pressure switch type operation method that stops the motor that operates the compressor body or an automatic unloader type operation method that operates the compressor body without load without stopping the motor. In the compressor, based on the pressure data of the pressure detection means,
Pressure change data measuring means for measuring pressure change data indicating the relationship of pressure to time, and pressure change data at the time of pressure increase and pressure change data at the time of pressure drop based on the pressure change data of the pressure change data measuring means. Means for calculating the ratio of the main tank and the auxiliary tank connected to the main tank based on the relationship between the calculation result of the calculating means and the pressure change data of the pressure change data measuring means. A tank volume calculating unit, and selecting one of the pressure switch type operating mode and the automatic unloader type operating mode based on a relationship between the calculation result of the tank volume calculating unit and the calculation result of the calculating unit. And an operating mode setting means for setting the operating mode.