JPH025794A - Air blower - 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 the Invention The present invention relates to a blower device for supplying combustion air, for example in gas or oil combustion machines.

2. Description of the Related Art Conventionally, this type of combustion air bag W1t has a casing 2, an impeller 3, and a motor 4, as shown in FIG. There is. As shown in FIG. 5, the torque characteristic of the motor 4 is expressed as a straight line under a constant voltage condition when the horizontal axis is represented by torque T and the vertical axis is represented by rotational speed n. Now, consider two different torque characteristics A and B in FIG. C and D show the closed and open characteristic curves when the exhaust port 2b of each motor 4 is closed or opened, and E shows the load characteristic curve when the blower l installed in the device is operated. , F and G are closed points on torque characteristics A and B, H and I are open points on torque characteristics A and B, and J
It shows the load points respectively. At this time, torque characteristic A
, B shows the air blowing characteristics of pressure P and air volume Q.
As shown in the figure, the torque changes as λ and B' depending on the gradients of the torque characteristics A and B in FIG. For this reason, motors have been designed by selecting torque characteristics that maximize efficiency at the operating point. Here, G' and G' are closed points on the air blowing characteristics A' and B', I(' and I' are open points on the air blowing characteristics A' and B', and J' is a load point.

Problem to be Solved by the Invention However, with the above torque characteristics, in case A, the starting torque is large as shown in No. 5 (9), but
As shown in the figure, the pressure at the closing point F is not much different from the pressure at the load point J', resulting in instability such as surging, which causes abnormal noise called oscillating combustion in combustion machines. ing. Also, in the case of B, conversely, the 6th
As shown in the figure, since the pressure at the closing point G' is greater than the pressure at the load point J', it is effective in suppressing vibration combustion, but the fifth
As shown in the figure, the problems were that the starting torque was small, the responsiveness at low temperatures was poor, and the efficiency was poor.

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a blower device that can obtain a large starting torque, prevent vibration combustion from occurring in a combustion machine, and suppress noise.

Means for Solving the Problems In order to solve all of the above-mentioned problems, the blower device of the present invention has an intersection point near the load point in the torque characteristic, and has different slopes on the high torque side and the low torque side, and This motor is equipped with two torque characteristics in which the slope of the torque is larger than that on the high torque side.

Effect With the above configuration, the closing point is set on the low-torque side torque characteristic with a large slope, so the pressure at the closing point in the air blowing characteristics is sufficiently higher than the pressure at the load point, and vibration combustion due to surging etc. is prevented. and the torque at the intersection where the two torque characteristics switch is near the load point,
The operation at the load point can be performed stably, and since the starting torque is set on the torque characteristic straight line on the high torque side with a small gradient, it can be made sufficiently large.

Actual travel example Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a block diagram of the main parts of a blower device showing an embodiment of the present invention. In FIG. 1, the motor 4 includes a rotor 7 having a permanent magnet 5 attached to its outer periphery and fixed to a rotating shaft 6, and a first coil 8, a second coil 9, etc. provided opposite the permanent magnet 5. It consists of a stator lO, and coils 8 and 9.
The energization to is controlled by the switching circuit section 11. That is, the coils 8 and 9 are configured to be switched to a power supply by the switching circuit section 11 so that a series circuit of the first coil 8 and the second coil 9 or only the first coil 8 is connected. . Further, a current detection section 12 is interposed between the first coil 8 and the electric wire, and the switching operation of the switching circuit section 11 is performed depending on the detection level of this current detection section 12.
When the detection level of the current detection unit 12 becomes below a predetermined setting level, only the 28 l coil 8 is energized.

The operation of the above configuration will be explained with reference to the first torque characteristic diagram and the third blowing characteristic diagram shown in FIG. In Fig. 2, a indicates the torque characteristic when the first coil/I/8 and the second coil 9 are connected in series, b indicates the torque characteristic when only the first coil 8 is connected, and C indicates the torque characteristic when the first coil/I/8 and the second coil 9 are connected in series. d is the open characteristic curve, e is the load characteristic curve, g is the closed point,
h indicates an open point, and j indicates a loaded point. k is lower than load point j
・At the intersection of torque characteristics a and b located near the torque side,
On the low torque side, the slope is larger than on the high torque side, and the open characteristic curve d, which determines the open point h'5r, and the load characteristic curve e, which determines the load point j, pass over the torque characteristic a with a small slope. , the closed-off characteristic curve cl that determines the closed-off point g
The first coil 8 and the second coil 9 are each designed to pass over a torque characteristic having a large gradient d.

Further, the current at the intersection point k of the torque characteristics a and b corresponds to the set level of the current detection section 12.

In addition, as shown in Fig. 3, the air blowing characteristics of this air blower are such that, depending on the slopes of the torque characteristics a and b, a air blowing characteristic a' with a small slope is obtained in a high air volume region, and a slope is low in a low air volume region. A large air blowing characteristic b' can be obtained. Here, g' is the closing point,
e' and j' are the load curve and load point, h' is the open point, the closed point g' is obtained on the torque characteristic b', and the load point j' and the open point h' are obtained on the torque characteristic b'. .

With the above configuration, as shown in FIG. 3, the closing point g' is set on the air blowing characteristic b' with a steep slope and is sufficiently higher than the pressure at the load point j', thereby preventing surging of the air blower 1. This also reduces the impact on external equipment such as combustion machines. Furthermore, since the torque at the intersection k where the torque characteristics a and b switch is on the lower torque side than the load point j and near the load point j, the operation at the load point can be performed stably, and the starting torque is Since it is set on the torque characteristic a on the high torque side with a small slope, the starting torque can be sufficiently large, and furthermore, in the normal usage range including the load point j, it is possible to suddenly realize the blowing characteristics of a high air volume type, which reduces noise and other problems caused by the blower. There is no problem with performance.

Effects of the Invention As described above, according to the air blowing device of the present invention, the intersection is set near the load point, the slope is different on the high torque side and the low torque side, and 1
Motors with two torque characteristics where the gradient on the low torque side is larger than the gradient on the high torque side are used in the blower device (2
As a result, the closing point pressure of the air blowing characteristics can be increased while the starting torque remains large.As a result, when used in combustion engines, etc., it is possible to blow air in low air volume ranges without any problems even during overtime at low temperatures. Surging of the device itself can be prevented and vibration combustion can be suppressed.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of the main parts of an air blower showing an embodiment of the present invention, Fig. 2 is a torque characteristic diagram of the air blower, Fig. 3 is an air blowing characteristic diagram of the air blower, and Fig. 4 is a diagram of the air blower. The schematic diagram, FIGS. 5 and 6 are a torque characteristic diagram and an air blowing characteristic diagram of a conventional blower device. 4...Motor, 5...Permanent magnet, 6...Rotating shaft,
7... Rotor, 8.9... First and second coils, 10... Stator, 11... Switching circuit diagram, 12...
...Current detection section, a, b...Torque characteristics, a/, b
/...Blowing characteristics, g, g'...Closing point, h, h'
...Open point, j, j'...Load point, k...Torque characteristic a. intersection of b. Agent Yoshi Morimoto Buddhist painting Figure 1 Island Figure 3 Figure 2 Figure 4

Claims (1)

[Claims] 1. Set the intersection near the load point in the motor torque characteristics,
A blower device comprising a motor having two torque characteristics with different slopes on a high torque side and a low torque side, and a slope on the low torque side is larger than that on the high torque side.