JPH0481585A - Air compressor - Google Patents

Abstract

PURPOSE:To deliver compressed air at once when pressure went down so quickly by operating a starting load relieving means in the case where a revolution in an air compressing motor is lower than the reference speed. CONSTITUTION:A revolution in a motor 14 at time of starting is detected by an encoder 26, and it is fed to a control circuit 27. Then, this control circuit 27 compares the inputted revolution with the preset reference speed, and when the inputted revolution is lower than the reference speed, a push solenoid 16 is turned on, making it perform no-load operation. Next, when the inputted speed goes beyond the reference one, at the point of time, the push solenoid 16 is turned to OFF, starting the compression operation. With this constitution, starting operation is quickly finished and compression is startable in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION ``Field of Industrial Application'' This invention relates to an air compressor with improved handling properties. ``Prior Art'' Figure, No. 9
The figure is a side view showing the internal structure of the compressor 1, and FIG. 1O is a front view showing the internal structure of the compressor 1. In Fig. 8, numeral 2 is an intake port, 3 is an exhaust port, 4 is a power switch,
5 is a pressure reducing valve, 6 is a pressure gauge, 7a and 7b are cabbage plates, 8 is a train cock, and 9 is a hose.

Next, in FIG. 9, reference numeral 10 is a delay circuit, 11 is a capacitor, 12 is an air tank, and 13 is an ano rubber. Next, in Fig. 1O, 14 is an air compression motor;
5 is a compressor main body, 16 is a pop-up solenoid, 17 is a pressure switch, 18 is a switch for connecting an auxiliary tank, and 19 is a relief valve. Next, FIG. 11 is a block diagram showing the electrical configuration of the air compressor 1, and in this figure, reference numeral 20
is a power plug, 20a is a grounding clip, and 21 is a thermal protector.

In the air compressor configured as described above, when the power switch 4 is turned on, if the pressure switch 17 is closed, the delay circuit 10 is activated, and the pressure solenoid 16 is turned on, resulting in no-load operation. or start. Here, the reason for performing no-load operation at the start of operation is to reduce the starting load on the air compression motor 14. Especially when a 100cm single-phase AC motor is used as the drive source,
Since the starting torque is small, if a load is applied from the start of operation, the motor may stop and become unable to operate. To avoid such a situation, the load is reduced at startup.

Now, when the delay time (for example, after 4 seconds) ends, the output of the delay circuit 10 is turned off, and then the solenoid 16 is turned off and compression operation is started. When the pressure reaches 9.5 kgf after the start of the compression operation, the pressure switch 17 becomes open and the compression operation ends. Note that the delay time by the delay circuit 10 described above is set when the starting conditions are the worst.

In this way, if the pressure is below a predetermined value at the time of startup, the delay circuit 10 and the oil pressure valve 16 perform no-load operation for a certain period of time, thereby reducing the load.

"Problem to be Solved by the Invention" By the way, in the conventional air compressor mentioned above, if the pressure is below a predetermined value at startup, the load is reduced for a certain period of time at startup, or the load is reduced for a certain period of time at startup, or the time is set to Since the conditions are set to be poor, even if the starting conditions are good, no-load operation will occur for a certain period of time. For this reason, in situations where a large amount of compressed air is used, even if the pressure drops rapidly, there is a drawback that the air does not run out immediately.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an air compressor that can immediately deliver compressed air when the pressure drops rapidly.

"Means for Solving the Problem" The invention according to claim 1 provides an air compressor comprising a starting load reducing means, comprising: a rotation speed detection means for detecting the rotation speed of an air compression motor; , Compare a predetermined reference rotation speed with the rotation speed detected by the rotation speed detection means, and if the rotation speed is lower than the reference rotation speed, operate the starting load reducing means; In the invention according to claim 2, the air compressor includes a control means for stopping the operation of the starting load reducing means when the start-up load reducing means starts to rise rapidly. and a voltage detection means for detecting the voltage supplied to the air compression motor, and comparing a steady voltage value with a voltage value detected by the voltage detection means,
077, the starting load reducing means is operated when the voltage value is lower than the steady voltage value, and the control means is provided to stop the operation of the starting load reducing means when the voltage value starts to rise. The invention according to claim 3 is characterized in that the air compressor is equipped with a starting load reducing means, the current detecting means detecting the current supplied to the air compression motor, and the steady current value. Comparing the current value detected by the current detection means,
It is characterized by comprising a control means that operates the starting load reducing means when the current value is higher than the steady current value, and stops the operation of the starting load reducing means when the current value starts to drop. According to the configuration described in claim 1, the rotation speed of the air compression motor is detected at the same time as the startup, and (2) the detected rotation speed and the reference rotation speed are A comparison is made and if the rotational speed is lower than the reference rotational speed, no-load operation takes place.

The no-load operation is canceled when the rotational speed becomes higher than the reference rotational speed.

According to the configuration described in claim 2, the voltage value supplied to the air compression motor is detected at the same time as startup, and if the detected voltage value is lower than the steady voltage value, no-load operation is performed. It will be done. Then, the no-load operation is canceled when the voltage value starts to rise.

According to the configuration described in claim 3, the current value supplied to the air compression motor is detected at the same time as startup, and if the detected current value is higher than the steady current value, no-load operation is performed. It will be done. Then, the no-load operation is canceled when the voltage value starts to drop.

Embodiment F-- Hereinafter, embodiments of the present invention will be described with reference to the drawings. .

◇ Figure 1 shows an air compressor 2 according to a first embodiment of the present invention.
FIG. 2 is a block diagram showing the electrical configuration of the first embodiment.

Note that in FIGS. 1 and 2, parts common to those in FIGS. 8 to 11 described above are designated by the same reference numerals, and their explanations will be omitted.

In this first embodiment, an encoder 26 is attached to the rotating shaft of an air compression motor (hereinafter referred to as motor) 14, and a control circuit 27 that inputs the output of this encoder 26 and performs a predetermined function. The control circuit 27 is different from the conventional technology in that it has a CPU (not shown).
(Central Processing Unit), ROM (Read Only Memory), R
It is comprised of an AM (random access memory), a comparison circuit, an interface circuit, etc., and a program for controlling the CPU is written in the ROM.

The rotational speed of the motor 14 at the time of startup is detected by the encoder 26 and supplied to the control circuit 27 .

The control circuit 27 compares the input rotation speed with a predetermined reference rotation speed (written in the ROM), and if the input rotation speed is lower than the reference rotation speed, the bush solenoid 16 Turn on and perform no-load operation. When the input rotation speed exceeds the reference rotation value, the bush solenoid 16 is turned off at that point and compression operation is started. Here, FIG. 3 shows a torque curve with respect to the rotational speed of the motor 14. As shown in this figure, the motor 14
If the rotational speed of the motor 14 is lower than the reference rotational speed Nb, starting is performed, and the starting is completed when the rotational speed of the motor 14 exceeds the reference rotational speed Nb. In addition, in this first embodiment, the compressor can be started even if the start-up time becomes long, and the compressor is protected by having a function to stop the compressor if the start-up time is abnormally long. You can also do that.

Thus, in this first embodiment, the motor 14
The rotational speed of the engine is detected, and when the rotational speed is lower than the reference rotational speed, a load reduction operation is performed, and the load reduction operation is stopped when the rotational speed becomes higher than the reference rotational speed.

◇ Next, FIG. 4 is a block diagram showing the electrical configuration of a second embodiment of the present invention. In this second embodiment,
This differs from the prior art in that it includes a voltage detector 28 inserted into the power supply line 14L of the motor 14, and a control circuit 29 that inputs the output of this voltage detector 28 and performs a predetermined function. be. The control circuit 29 is similar to the control circuit 27 in the first embodiment described above.
RAM.

It is configured with a comparison circuit, an interface circuit, etc., and a program for controlling the CPU is written in the ROM.

The supply voltage at startup is detected by a voltage detector 28;
The signal is supplied to the control circuit 29. The control circuit 29 compares the input voltage value with the steady voltage value (written in the above ROM), and if the input voltage value is lower than the steady voltage value, turns on the bushing solenoid 16 and turns on the no-load state. Have them drive. Then, when the input voltage value starts to rise, the pressure solenoid 16 is turned off and compression operation is started. Here, FIG. 5 is a characteristic diagram showing the voltage supplied to the motor 14 with respect to the elapsed time from the time of start-up.

As shown in this figure, the supply voltage is lower than the steady voltage at the start of startup. Additionally, startup is complete when the supply voltage begins to rise. In this second embodiment, as in the first embodiment described above, it is possible to start the compressor even if the start-up time is long, and there is also a function to stop the compressor if the start-up time is abnormally long. By providing this, the compressor can be protected.

Thus, in this second embodiment, the motor 14
The system detects the input voltage value supplied to the system, performs no-load operation when this voltage value is lower than the steady voltage value, and completes startup when the voltage value begins to rise.

◇ Next, FIG. 6 is a block diagram showing the electrical configuration of a third embodiment of the present invention. In this third embodiment,
This differs from the prior art in that it includes a current detector 30 inserted into the power supply line 14L of the motor 14, and a control circuit 31 that inputs the detected value of the current detector 30 and performs a predetermined function. It is. Moreover, the control circuit 3 of this embodiment
1 is the above-mentioned 1st. Control circuit 27 in the second embodiment.
Similarly to No. 29, it is configured with a CPU, ROM, RAM, comparison circuit, interface, etc.

The motor current at startup is detected by a current detector 30 and supplied to a control circuit 31. The control circuit 31 receives the input current value and the steady current value (written in the above ROM).
If the input current value is higher than the steady voltage value, the private solenoid 16 is turned on to perform no-load operation.

Then, when the input current value starts to drop, the buzz solenoid 16 is turned off and compression operation is started.

Here, FIG. 7 is a characteristic diagram showing the input current to the motor 14 with respect to the elapsed time from the start of startup. As shown in this figure, the input current value is higher than the steady current value at the start of startup. Start-up is complete when the input current starts to drop. In addition, in this third embodiment, as in the above-mentioned embodiments 1.2, the compressor can be started even if the startup time becomes long, and if the startup time is abnormally long, the compressor can be stopped. By providing this function, the compressor can be protected.

Thus, in this third embodiment, the motor 14
The input current value supplied to the engine is detected, and when this current value is higher than the steady current value, no-load operation is performed, and startup is completed when the current value begins to drop.

"Effects of the Invention" As explained above, according to the air compressor according to claim 1, the rotation speed of the air compression motor is detected, and when the rotation speed is lower than the reference rotation speed, the load reduction operation is performed. According to the air compressor according to claim 2, the load reduction operation is stopped when the rotation speed becomes higher than the reference rotation speed. The input voltage value is detected, and if this voltage value is lower than the steady voltage value, no-load operation is performed, and the startup is completed when the voltage value starts to rise. According to the air compressor described, the input current value supplied for air compression is detected, and if this current value is higher than the steady current value, no-load operation is performed, and the point at which the current value begins to drop is detected. Since the startup is completed by the following steps, the effect described below is achieved.

■Quickly finishes startup and starts compression, allowing efficient operation.

■It is possible to start even if the startup time becomes long.

■If the start-up time is abnormally long, it will be stopped, so the compressor can be protected.

[Brief explanation of the drawing]

FIG. 1 is a front view showing the internal structure of an air compressor according to the first embodiment of the present invention, FIG. 2 is a block diagram showing the electrical configuration of the first embodiment, and FIG. A waveform diagram for explaining the operation of the example, FIG. 4 is a block diagram showing the electrical configuration of the second embodiment of the invention, and FIG. 5 is a waveform diagram for explaining the operation of the second embodiment. Fig. 6 is a block diagram showing the electrical configuration of a third embodiment of the present invention, Fig. 7 is a waveform diagram for explaining the operation of the third embodiment, and Fig. 8 is an external appearance of a conventional air compressor. FIG. 9 is a side view showing the internal structure of the compressor, FIG. 10 is a front view showing the internal structure of the compressor, and FIG. 11 is a block diagram showing the electrical configuration of the compressor. It is. 4... Air compression motor, 6... Bush solenoid, 6... Encoder (rotation speed detection means), 8...
...Voltage detector (voltage detection means), 0...Current detector (current detection means), 7.29.31...Control circuit (control circuit).

Claims (3)

[Claims] (1) An air compressor equipped with a starting load reduction means, which includes a rotation speed detection means for detecting the rotation speed of an air compression motor, and a predetermined reference rotation speed detected by the rotation speed detection means. Control that compares the number of revolutions with the number of revolutions, operates the starting load reducing means when the number of revolutions is lower than the reference number of revolutions, and stops the operation of the starting load reducing means when the number of revolutions starts to rise rapidly. An air compressor comprising: means. (2) An air compressor equipped with a starting load reduction means, which includes a voltage detection means for detecting the voltage supplied to the air compression motor, and a steady voltage value and a voltage value detected by the voltage detection means. and a control means for operating the starting load reducing means when the voltage value is lower than the steady voltage value and stopping the operation of the starting load reducing means when the voltage value starts to rise. An air compressor characterized by: (3) An air compressor equipped with a starting load reduction means, which includes a current detection means for detecting the current supplied to the air compression motor, and a steady current value and a current value detected by the current detection means. and a control means for operating the starting load reducing means when the current value is higher than the steady current value and stopping the operation of the starting load reducing means when the current value starts to drop. An air compressor characterized by: