JP2002277060A - Hot air heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the overheat of a hot air heater by quickly detecting the abnormality of a fan as the amount of combustion is increased. SOLUTION: A combustion control unit 30 controls the amount of combustion of a burning instrument 4 while a fan control unit 31 sets the number of rotation of a ventilating fan 3 in accordance with the amount of combustion of the burning instrument 4. A number of rotation sensor 16 outputs a signal in accordance with the number of rotation of the ventilating fan 3. An abnormality detecting unit 32 detects the abnormality of the ventilating fan 3 when the number of rotation of the ventilating fan 3 is recognized that the same is lower than a predetermined lock number of rotation, which is lower than the set number of rotation. The abnormality detecting unit 32 is provided with the lock number of rotation at every set numbers of rotation in accordance with the amount of combustion while a difference between a set number of rotation and the lock number of rotation is reduced as the amount of combustion is increased. The combustion control unit 30 reduces the amount of combustion or stops the combustion when the abnormality detecting unit 32 has detected the abnormality of the ventilating fan 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a hot air heater such as a fan heater.

[0002]

2. Description of the Related Art In a hot air heater, air is taken into a main body case by a fan, the air is heated by the combustion heat of a combustor, and hot air is discharged to the outside from an outlet of the main body case by a fan. It has become. During combustion of the combustor, the number of revolutions of the fan is controlled to be set to a number of revolutions for supplying necessary air in accordance with the amount of combustion of the combustor.

[0003] When the rotation speed of the fan is abnormally reduced or the fan stops due to the fan biting foreign matter or the like, the discharge of warm air to the outside of the main body case is reduced. The machine may become too hot.

Therefore, in order to prevent the warm air heater from overheating due to the fan abnormality, the conventional warm air heater detects that the rotational speed of the fan becomes lower than a certain minimum rotational speed. Some have stopped the combustion of the combustor.
Further, in some cases, when the state in which the rotation speed of the fan has decreased from the set rotation speed by a certain rotation speed or more has continued for a certain period of time, the abnormality of the fan is detected and the combustion in the combustor is stopped.

[0005]

However, in the former case of the conventional hot air heater, the larger the combustion amount and the higher the set rotation speed, the longer it takes for the rotation speed of the fan from the set rotation speed to fall below the minimum rotation speed. And the hot air heater tends to be overheated. Also, in the latter case of the conventional hot air heater, regardless of the amount of combustion or the set number of revolutions, the abnormality of the fan is detected when the state in which the number of revolutions has become lower than the set number of revolutions for a certain period of time continues. The larger the amount, the shorter the time from the occurrence of an abnormality in the fan until the hot air heater overheats, so the larger the amount of combustion, the more likely it is that the hot air heater overheats before the abnormality is detected. there were.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned inconveniences, and to detect a fan abnormality more quickly as the combustion amount is larger, thereby preventing the warm air heater from overheating.

[0007]

In order to achieve the above object, a first aspect of the present invention is to provide a combustor housed in a main body case, air is taken into the main body case and heated by the combustor. A fan for discharging the discharged air out of the main body case, combustion control means for controlling the combustion amount of the combustor, fan control means for setting the number of revolutions of the fan according to the combustion amount of the combustor, A rotation speed sensor that outputs a signal corresponding to the rotation speed of the fan, and when it is recognized that the rotation speed of the fan has become equal to or less than a predetermined lock rotation speed lower than the set rotation speed based on the signal of the rotation speed sensor. A warm air heater provided with abnormality detecting means for detecting abnormality of the fan,
The lock rotation speed is provided for each set rotation speed according to the combustion amount, and the difference between the set rotation speed and the lock rotation speed is reduced as the combustion amount increases.

According to the first aspect of the present invention, the allowable range of the rotation speed from the set rotation speed to the lock rotation speed or less is smaller as the combustion amount is larger and the set rotation speed is larger.
The larger the combustion amount, the quicker the fan abnormality can be detected.

Next, according to a second aspect of the present invention, a combustor accommodated in a main body case, air is taken into the main body case, and air heated by the combustor is discharged out of the main body case. A fan that controls the amount of combustion of the combustor; a fan control unit that sets the number of revolutions of the fan according to the amount of combustion of the combustor; and a signal that corresponds to the number of revolutions of the fan. An abnormality of the fan is detected when it is recognized that the state in which the number of revolutions of the fan has become lower than the set number of revolutions by a certain number of revolutions or more has been continued for a predetermined period of time based on a signal outputted from the revolution number sensor and the revolution number sensor. In the warm air heater having an abnormality detecting means for detecting, the predetermined time is provided for each set number of revolutions corresponding to the combustion amount, and the predetermined time is shortened as the combustion amount increases.

According to the second aspect of the present invention, as the combustion amount increases and the set rotation speed increases, the predetermined time from when the rotation speed of the fan is reduced to a certain rotation speed or more to when the abnormality is detected is determined. Since it is short, the larger the combustion amount, the quicker the abnormality of the fan can be detected.

According to the third aspect of the present invention, the combustor housed in the main body case, air is taken into the main body case, and the air heated by the combustor is discharged out of the main body case. A fan, combustion control means for controlling the combustion amount of the combustor, fan control means for setting the rotation speed of the fan according to the combustion amount of the combustor, and outputting a signal corresponding to the rotation speed of the fan A rotation speed sensor that performs the rotation of the fan when it is recognized that the rotation speed of the fan has become equal to or less than a predetermined lock rotation speed that is lower than the set rotation speed for a predetermined time based on a signal from the rotation speed sensor. In a warm air heater provided with abnormality detecting means for detecting abnormality, a plurality of the lock rotation speeds having different values are provided for each of the set rotation speeds, and the predetermined time is provided for each lock rotation speed. , The lock Characterized in that the shorter the predetermined time number rolling corresponding higher low.

According to the third aspect of the present invention, when a certain set number of rotations is set, an abnormality occurs in the fan, and the number of rotations is lower than that of the plurality of lock rotations with respect to the set number of rotations. When the rotation speed becomes lower than the rotation speed, that is, when the rotation speed of the fan is greatly reduced and the degree of the abnormality is large, the predetermined time until the abnormality is detected is shorter, so that the abnormality of the fan can be quickly detected. it can.

In the above invention, it is preferable that when the abnormality detecting means detects abnormality of the fan, the combustion control means reduces the combustion amount of the combustor or stops the combustion. As a result, the larger the amount of combustion, the sooner the abnormality of the fan can be detected, and the warm air heater can be prevented from being overheated quickly. In addition, even if the amount of air taken into the main body case decreases due to a fan abnormality and abnormal combustion occurs, quickly detecting the abnormality of the fan and reducing the combustion amount of the combustor quickly reduces air-fuel consumption. It can improve and eliminate abnormal combustion.

In the above invention, when the abnormality detecting means detects an abnormality of the fan, the combustion control means reduces the combustion amount of the combustor, and thereafter, the abnormality detecting means When the combustion control unit recognizes that the rotation speed of the fan is equal to or higher than a predetermined release rotation speed provided for each of the set rotation speeds at the time of the abnormality detection based on a signal of the rotation speed sensor, the combustion control unit It is preferable to return the combustion amount at the time of the abnormality detection to the combustion amount at the time of detecting the abnormality.
With this, after detecting an abnormality in the rotation speed of the fan and reducing the combustion amount of the combustor, if it is determined that the rotation speed is normal, the combustion amount is returned to the original. Combustion can be continued without giving the user a sense of incongruity.

In a first aspect of the present invention, the rotation speed sensor outputs a pulse signal corresponding to the rotation speed of the fan, and the abnormality detecting means detects a pulse interval of the rotation speed sensor pulse signal. It is preferable that the time is measured a plurality of times, and the number of revolutions of the fan is recognized based on an average value of the measured values. In the first mode, the fan abnormality is detected when the fan rotation speed becomes equal to or less than the lock rotation speed. However, the fan rotation speed can be accurately recognized based on the average value. Detection can be reduced.

In the second and third aspects of the present invention,
The rotation speed sensor outputs a pulse signal according to the rotation speed of the fan, and the abnormality detection unit measures the time between pulse intervals of the pulse signal of the rotation speed sensor, and based on the measured value, It is preferable to recognize the rotation speed of the fan. Thereby, in the second and third aspects,
For example, since the number of rotations of the fan can be recognized at the time of one pulse interval, it is determined in a short time whether the number of rotations of the fan has decreased below a certain number of rotations or less than the number of rotations of a lock, and an abnormality of the fan is detected. The time until the time can be shortened.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a hot air heater according to the first aspect of the present invention will be described with reference to FIGS. Figure 1
FIG. 2 is an overall system configuration diagram of a hot air heater according to one embodiment of the present invention, FIG. 2 is a block diagram of a main part of the hot air heater according to one embodiment, and FIG. FIG. 4 is a flowchart showing the rotation speed, the lock rotation speed, and the release rotation speed, and FIG. 4 is a flowchart for explaining the operation of the warm air heater according to the embodiment.

Referring to FIG. 1, a hot air heater of the present embodiment is, for example, a gas fan heater, and includes a duct 2, a blower fan 3, and a gas burner 4 (combustor) in a main body case 1 disposed indoors. , A duct 5, a gas supply pipe 6, and a control unit 7.

The duct 2 constitutes an air passage for hot air. An intake port 8 for taking in room air s is opened at the back of the main body case 1, and a hot air outlet 9 is connected to the main body case 1.
The front is open at the bottom. An air filter 10 that prevents dust and dirt from flowing into the duct 2 is detachably attached to the intake port 8. The outlet 9 is provided with a movable louver 11 for adjusting the degree of opening thereof, and the movable louver 11 is provided with a gad motor 12 for driving the same. A room temperature sensor 13 constituted by a thermistor is attached near the intake port 8 inside the duct 2, and the room temperature sensor 13 outputs a signal corresponding to the room temperature to the control unit 7.

The blower fan 3 has a fan motor 14 whose rotation speed changes in proportion to the current flow, and a rotating blade 15 which is arranged in the duct 2 facing the air outlet 9 and is driven to rotate by the fan motor 14. Have. The blower fan 3 sucks the room air s into the duct 2 from the intake port 8 by the rotation of the rotary blades 15 and mixes the sucked room air s with the combustion exhaust h of the gas burner 4 incorporated in the duct 2. It is blown into the room from the outlet 9 as warm air m.

The rotation axis of the fan motor 14 of the blower fan 3 is provided with a rotation speed sensor 16 composed of a Hall IC or the like for detecting the rotation speed. The rotation speed sensor 16 outputs a signal corresponding to the rotation speed of the fan motor 14 to the control unit 7. Rotation speed sensor 1 of the present embodiment
Reference numeral 6 denotes a Hall IC that outputs a signal of 4 pulses per rotation of the blower fan 3.

The gas burner 4 has a combustion plate 18 disposed in a combustion cylinder 17 disposed in the duct 2, and an ignition electrode 19 for igniting a mixture of combustion air and fuel gas downstream of the combustion plate 18. It is arranged on the side. The combustion exhaust h of the gas burner 4 is discharged from the combustion drum 17 into the duct 2. On the downstream side of the combustion plate 18, a thermocouple 20 for detecting the presence or absence of a combustion flame is arranged.
An electromotive force is generated in a state where the electromotive force is exposed to the combustion flame of the gas burner 4, and the generated electromotive force is output to the control unit 7.

The duct 5 is a passage for supplying the indoor air s (combustion air) and the fuel gas to the gas burner 4, and communicates with the inside of the combustion cylinder 17 of the gas burner 4 and the duct 2
Is incorporated in the main body case 1 and the main body case 1
Has an air intake port 21 for room air s which is open at the back of the vehicle. At a location on the gas burner 4 side of the duct 5, a nozzle 22 attached to the tip of the gas supply pipe 6 is provided.
In the duct 5, the inside of the combustion drum 17 becomes negative pressure due to the rotation operation of the blower fan 3, and the room air s is sucked from the intake port 21, and the sucked room air s flows from the nozzle 22 of the gas supply pipe 6. The fuel gas is mixed with the injected fuel gas, and the mixture is supplied to the gas burner 4. The intake port 21 is covered by the air filter 10 together with the intake port 8 of the duct 2.

The gas supply pipe 6 is provided with solenoid valves 24 and 25 and a solenoid proportional valve 26 in order from the upstream side.
The solenoid valves 24 and 25 are opened by energization.
In the valve open state, the fuel gas is passed in the direction of the nozzle 22, and in the valve closed state in which the energization is stopped, the passage of the fuel gas is blocked.
The electromagnetic proportional valve 26 is a valve whose opening increases with the magnitude of the energizing current, and the energizing current is proportional to the amount of gas supplied to the gas burner 4.

An operation switch 27, a room temperature setting switch 28, and a filter lamp 29 are provided on the outer surface of the main body case 1. The operation switch 27 has its ON / OF
The F operation instructs the control unit 7 to start or end the heating operation. The room temperature setting switch 28 is an operation switch for setting the room temperature, and instructs the control unit 7 to raise or lower the set room temperature by, for example, 1 ° C. by a predetermined operation. When the clogging of the air filter 10 is progressing or the like, the filter lamp 29
When the air volume at the time of the rotation operation becomes smaller to some extent as compared to the normal case, the light is turned on by the energization control of the control unit 7, and the light notifies the user of the necessity of cleaning the air filter 10 or the like.

Referring to FIG. 2, the control unit 7 is constructed using a microcomputer or the like. The major functional components are roughly classified into a combustion control unit 30, a fan control unit 31, an abnormal The detection unit 32 is provided.

The combustion control unit 30 controls the solenoid valves 24 and 25 of the gas supply pipe 6 and the electromagnetic proportionality based on the instruction signals of the operation switch 27 and the room temperature setting switch 28 and the detection signals of the room temperature sensor 13 and the thermocouple 20. By controlling the energization of the valve 26 and the ignition electrode 19, the combustion of the gas burner 4 is controlled, such as ignition, extinguishment of the gas burner 4, and adjustment of the combustion amount (adjustment of the supply amount of fuel gas). During the combustion operation including the ignition operation of the gas burner 4, the combustion control unit 30
Can be set to twelve types of 1 to 12 speeds. Of the 12 types of set combustion amounts, the 12th speed corresponds to the maximum combustion amount, and the 1st speed corresponds to the minimum combustion amount.

The fan control unit 31 controls the energization of the fan motor 14 based on the instruction signals of the operation switch 27 and the room temperature setting switch 28 and the detection signals of the room temperature sensor 13, the rotation speed sensor 16 and the thermocouple 20. In addition, the number of rotations of the blower fan 3 is controlled, thereby controlling the air volume of the blower fan 3 including the combustion air to the gas burner 4. During the combustion operation including the ignition operation of the gas burner 4, the fan control unit 31 can set the rotation speed of the blower fan 3 to 12 types of 1 to 12 speeds in accordance with the set combustion amount of the gas burner 4. . Of the twelve types of set rotational speeds, the 12th speed corresponds to the maximum rotational speed during combustion, and the 1st speed corresponds to the minimum rotational speed during combustion.

The set combustion amount of the gas burner 4 and the set rotation speed of the blower fan 3 at each speed are set to predetermined values in advance, and the value of each predetermined value is basically the set combustion amount of the gas burner 4. Is set so that the air-fuel ratio of the gas burner 4 at each speed becomes optimal by making the speed of the air blower 3 and the speed of the set rotation speed of the blower fan 3 the same.

The control of the set combustion amount by the combustion control unit 30 and the control of the set rotation speed by the fan control unit 31 are performed according to a predetermined sequence. When performing the temperature control as one of the sequences, the combustion control unit 30
Based on the detected room temperature and the room temperature set by the room temperature setting switch 28, the speed of the set combustion amount is set so as to obtain the combustion amount necessary to match them, and the fan control unit 3
Reference numeral 1 denotes the speed of the set rotation speed of the blower fan 3,
Set the same speed as the set combustion amount of 0.

In the present embodiment, when the combustion control unit 30 and the fan control unit 31 perform temperature control, the abnormality detection unit 32 operates to perform fan lock detection and fan lock release described in detail below. .

First, the detection of the fan lock will be described. As illustrated in FIG. 3, the abnormality detection unit 32 has predetermined lock rotation speeds b1 to b12 corresponding to the set rotation speeds a1 to a12 of the first to twelfth speeds of the fan control unit 31, respectively. . As the speed of the set combustion amount is higher and the speed of the set speed is correspondingly higher, the difference an−bn between the set speed an and the lock speed bn (n = 1, 2, 3,..., 1
The size of 2) is smaller.

The abnormality detection section 32 has a fan lock detection timer 33, and by using this timer 33,
The timer is counted each time four pulses of a pulse signal corresponding to the rotation speed of the blower fan 3 are input from the rotation speed sensor 16 to measure the time (four pulse periods) of the four pulse intervals. . Rotation speed sensor 16 of the present embodiment
Outputs a four-pulse signal per rotation of the blower fan 3, so that the abnormality detection unit 32
The number of rotations of the blower fan 3 can be recognized based on the 4-pulse period measured by 3. In the present embodiment, the abnormality detection unit 32 measures the four pulse periods four times in succession, calculates an average value of the measured values, and recognizes the rotation speed of the blower fan 3 based on the average value. I do. Thereby, the rotation speed of the blower fan 3 can be recognized with high accuracy.

The abnormality detecting section 32 detects the blower fan 3
When the number of rotations becomes equal to or less than the lock rotation number corresponding to the speed of the set rotation number at that time, it is detected that the blower fan 3 is abnormal (fan lock detection). Then, the abnormality detection unit 32 outputs a signal of fan lock detection to the combustion control unit 30. When the signal of the fan lock detection is input, the combustion control unit 30 changes the speed of the set combustion amount at that time from the second speed to the first speed.
When the speed is the second speed, the speed of the set combustion amount is forcibly reduced to the first speed, and when the speed of the set combustion amount at that time is the first speed, the combustion of the gas burner 4 is stopped.

Next, the release of the fan lock will be described. As shown in FIG. 3, the abnormality detection unit 32 is
It has predetermined release rotation speeds c1 to c12 corresponding to the set speed rotation speeds a1 to a12, respectively. Set rotation speed a1
Ａa12 is smaller, the corresponding release rotation speeds c1 to c1
The size of 2 is smaller.

Further, the abnormality detecting section 32 has a fan lock release timer 34, and by using this timer 34,
Each time one pulse of a pulse signal corresponding to the rotation speed of the blower fan 3 is input from the rotation speed sensor 16, the timer is counted, and the pulse interval time (one pulse cycle) for one pulse of this signal is measured. . As described above, the rotation speed sensor 16
Outputs a four-pulse signal per rotation of the blower fan 3, so that the abnormality detection unit 34
4, the number of rotations of the blower fan 3 can be recognized based on one pulse period.

When the fan lock is detected, the abnormality detection unit 32 determines that the recognized rotation speed of the blower fan 3 is equal to or greater than the release rotation speed according to the set rotation speed at the time of the fan lock detection. At this time, it is determined that the blower fan 3 is normal (fan lock release). Then, the abnormality detection unit 32 outputs a fan lock release signal to the combustion control unit 30. When the fan lock release signal is input, if the speed of the set combustion amount at the time of fan lock detection is 2nd to 12th speeds, the combustion control unit 30 sets the speed of the set combustion amount to the fan lock. Return to the set combustion amount at the time of detection. If the speed of the set combustion amount at the time of detection of the fan lock is 1st speed, the combustion of the gas burner 4 has already been stopped by the control of the combustion control unit 30, and thus the set combustion amount is not restored.

Next, the operation of the warm air heater of the present embodiment in detecting the fan lock and releasing the fan lock will be described. Referring to FIG. 4, when the warm air heater of the present embodiment performs the temperature control, the combustion control unit 30 matches the detected room temperature of the room temperature sensor 13 with the room temperature set by the room temperature setting switch 28 based on the detected room temperature. The speed of the set amount of combustion is set so as to obtain the amount of combustion required for the combustion (STEP 1). The fan control unit 31 sets the speed of the set rotation speed of the blower fan 3 to the same speed as the set combustion amount of the combustion control unit 30 (S
TEP2).

When the temperature control is being performed, the abnormality detecting unit 32 measures the four pulse periods of the pulse signal output from the rotation speed sensor 16 using the fan lock detection timer 33, and averages the measured values. Based on the value, the rotation speed of the blower fan 3 is recognized. Then, the abnormality detection unit 32 determines whether the recognized rotation speed of the blower fan 3 is equal to or less than the lock rotation speed with respect to the set rotation speed at that time (STEP).
3). When it is recognized that the rotation speed of the blower fan 3 is not lower than the lock rotation speed, the process returns to STEP3.

On the other hand, when it is recognized that the rotation speed of the blower fan 3 is equal to or lower than the lock rotation speed, the abnormality detection unit 32
It is determined that a fan lock has been detected (STEP 4), and a signal for fan lock detection is output to the combustion control unit 30. In response, the combustion control unit 30 forcibly sets the speed of the set combustion amount to the first speed (STEP 5).

Further, the abnormality detection unit 32 determines whether or not the rotation speed of the blower fan 3 is equal to or less than the lock rotation speed corresponding to the first-speed set rotation speed (STEP 6). If the lock speed is equal to or less than the first-speed lock rotation speed, the combustion control unit 30
Since the fan lock detection signal is input in a state where the set combustion amount is forcibly set to the first speed, the combustion of the gas burner 4 is stopped (STEP 7).

Next, when the speed of the set combustion amount is forcibly set to the first speed while the fan lock is detected,
The abnormality detection unit 32 measures one pulse cycle of the output signal of the rotation speed sensor 16 using the fan lock release timer 34, and recognizes the rotation speed of the blower fan 3 based on the measured value. Then, the abnormality detection unit 32 determines whether the recognized rotation speed of the blower fan 3 is equal to or greater than the release rotation speed with respect to the set rotation speed at the time of fan lock detection (STEP).
8). When it is recognized that the rotation speed of the blower fan 3 is not higher than the release rotation speed, the process returns to STEP8.

On the other hand, when it is recognized that the rotation speed of the blower fan 3 is higher than the release rotation speed, it is determined that the fan lock is released (STEP 9), and a signal for releasing the fan lock is output to the combustion control unit 30. In response, the combustion control unit 30
Resets the speed of the set combustion amount to the speed of the set combustion amount at the time of fan lock detection (STEP 10).

According to the present embodiment, the larger the combustion amount set by the combustion control unit 30 and the larger the rotation speed set by the fan control means 31, the more the difference between the set rotation speed and the lock rotation speed, that is, Since the allowable range of the rotation speed for detecting the abnormality of the blower fan 3 is small,
The abnormality detection unit 32 can quickly detect an abnormality in the rotation speed of the blower fan 3.

When the fan lock is detected, the abnormality detection unit 32
Is the rotation speed sensor 1 by the fan lock detection timer 33.
Since the four pulse periods of the six pulse signals are measured a plurality of times and the rotation speed of the blower fan 3 is recognized based on the average value,
Since the rotation speed of the blower fan 3 can be accurately recognized with a small error, erroneous detection of an abnormality of the blower fan 3 can be reduced.

Further, the fan lock is detected by the abnormality detection unit 32, the speed of the set combustion amount of the gas burner 4 is forcibly reduced to the first speed, and then the fan lock is determined to be released by the abnormality detection unit 32. Since the set combustion amount is returned to the speed at the time of fan lock detection, the combustion amount of the gas burner 4 is returned to the original value even when an abnormality is erroneously detected, so that combustion can be performed without giving the user a sense of incongruity. Can be continued.

When the fan lock is released, the abnormality detection unit 32
Is the rotation speed sensor 1 by the fan lock release timer 34.
6, the rotation speed of the blower fan 3 can be recognized in a short time by the time of one pulse cycle of the pulse signal, and the fan lock can be unlocked. Can be restored.

Next, an embodiment of the hot air heater according to the second aspect of the present invention will be described with reference to FIG. FIG. 5 is a diagram showing a predetermined time for detecting an abnormality of the hot air heater according to the embodiment of the second aspect. The description of the parts common to the first embodiment is omitted.

In the hot air heater according to the embodiment of the second aspect,
The abnormality detection unit 32 performs the first to first speeds corresponding to the set combustion amounts of the first to twelfth speeds in the same manner as in the first embodiment.
Lock speeds and release speeds of the first to twelfth speeds are respectively provided corresponding to the set speeds of the second speed.

However, unlike the above-described embodiment of the first embodiment, the abnormality detecting section 32 of the second embodiment is different from the first embodiment in that each of the lock speeds corresponding to each of the set speeds of the first to twelfth speeds. Are constant. Then, the abnormality detection unit 3
2 detects an abnormality of the blower fan 3 when it is recognized that the state in which the rotation number of the blower fan 3 has become equal to or lower than the lock rotation number has continued for a predetermined time. Therefore, as shown in FIG.
The abnormality detection unit 32 has predetermined times t1 to t12 corresponding to the lock speeds of the first to twelfth speeds. As the speed of the set combustion amount is larger, and accordingly, the speed of the set combustion amount is larger, each of the predetermined times t1 to
The length of t12 is shorter.

Further, unlike the above-described embodiment of the first embodiment, the abnormality detecting section 32 of the second embodiment of the second embodiment uses a fan lock detection timer 33 to generate two pulses of the pulse signal of the rotation speed sensor 16. The time of the minute pulse interval (two pulse periods) is measured, and the rotation speed of the blower fan 3 is recognized based on the measured value. Therefore, the number of rotations of the blower fan 3 can be recognized in a short time with a pulse interval of two pulses.

According to the second embodiment of the present invention, the larger the set combustion amount and accordingly the larger the set number of revolutions,
A predetermined time period t1 to t12 required from when the lock rotation speed becomes equal to or less than the set rotation speed to when an abnormality is detected.
Since the length is shorter, the larger the amount of combustion, the faster the abnormality of the rotation speed of the blower fan 3 can be detected.

Next, an embodiment of a hot air heater according to a third aspect of the present invention will be described with reference to FIG. FIG. 6 is a diagram showing a lock rotation speed of the hot air heater and a predetermined time for detecting an abnormality in the present embodiment. The description of the same parts as those of the first or second embodiment will be omitted.

In the present embodiment, unlike the first and second embodiments described above, the abnormality detecting section 32 performs the operation for the first speed to the first speed.
For each of the set speeds a1 to a12 of the 12th speed,
It has a plurality of lock rotation speeds having different values, and has a predetermined time corresponding to each lock rotation speed. FIG.
, For example, a plurality of lock rotation speeds b7-1 and b7-2 are provided for a set rotation speed a7 of the seventh speed, and predetermined times t7-1 and t7 corresponding to the respective lock rotation speeds. −
Two. The length of the predetermined time t7-1 corresponding to the lower lock rotation speed b7-1 is shorter than the predetermined time t7-2 corresponding to the higher lock rotation speed b7-2.

Accordingly, when the set rotation speed is set to the seventh speed and the rotation speed becomes equal to or lower than the lock rotation speed b7-2 due to the occurrence of an abnormality in the blower fan 3, a predetermined time is required until the abnormality is detected. Although t7-2 is required, the lock rotation speed b7-, whose rotation speed is lower than the lock rotation speed b7-2.
When it becomes 1 or less, an abnormality can be detected in a predetermined time t7-1 shorter than the predetermined time t7-2.

When the abnormality detection unit 32 recognizes that the state in which the rotation speed of the fan has become equal to or lower than the lock rotation speed b7-2 has continued for a predetermined time t7-2, and has detected the fan lock, the combustion control unit 32 Numeral 30 sets the speed of the combustion amount to the first speed. Further, when the abnormality detection unit 32 recognizes that the state in which the rotation speed of the fan has become equal to or less than the lock rotation speed b7-1 has continued for the predetermined time t7-1, and has detected the fan lock, the combustion control unit 30 sets the gas burner. 4 is stopped.

As described above, according to the present embodiment, when a certain set rotation speed is set, the rotation speed of the blower fan 3 is set to one of a plurality of lock rotation speeds provided for the set rotation speed. The lower the lock rotation speed, the lower the rotation speed, that is, the lower the rotation speed of the blower fan 3 and the greater the degree of abnormality, the lower the lock rotation speed until the abnormality is detected. Since the predetermined time is short, the abnormality of the blower fan 3 can be quickly detected. Furthermore, if the degree of decrease in the rotation speed of the blower fan 3, that is, the degree of abnormality is small, the combustion amount is reduced,
If the degree of abnormality is large, the combustion can be stopped, and the processing can be changed according to the degree of abnormality of the fan.

In each of the above embodiments, the blower fan 3
When an abnormality of the blower fan 3 occurs, such as a sudden decrease in the rotation speed or a stoppage of the blower fan 3 due to a foreign object biting into the body, the amount of air taken into the main body case 1 decreases, and the air-fuel consumption decreases. And abnormal combustion is likely to occur. In such a case as well, according to each embodiment, by detecting the abnormality of the blower fan 3 quickly and reducing the amount of combustion, it is possible to quickly improve the air-fuel efficiency and eliminate the abnormal combustion.

In each of the above-described embodiments, the combustion control unit 30 has a plurality of set combustion amounts at a plurality of speeds, and the combustion of the gas burner 4 is set by setting one of the set combustion amounts at the plurality of speeds. Although the control is performed, the control is not limited to this, and the control may be performed by continuously changing the combustion amount based on the room temperature or the like.

Further, in each of the above embodiments, the abnormality detecting section 32 performs the operation of releasing the fan lock in addition to the detection of the fan lock. However, the present invention is not limited to this. Only the fan lock detection may be performed, and the combustion amount may not be restored by releasing the fan lock.

When releasing the fan lock,
In the state of the fan lock detection, the abnormality detection unit 32
When it is recognized that the state in which the rotation number of the blower fan 3 has become equal to or greater than the release rotation number provided corresponding to the set rotation number at the time of detecting the fan lock has continued for a predetermined time, it is determined that the blower fan 3 is normal. Then, the fan lock may be released. This predetermined time is set so that when the rotation speed of the blower fan 3 instantaneously exceeds the release rotation speed due to a measurement error of the pulse period of the pulse signal of the rotation speed sensor 16, it is erroneously determined that no fan lock is detected. Provided to prevent. The predetermined time may be a fixed time common to each of the release rotation speeds c1 to c12, or may be a different time for each release rotation speed as needed.

[Brief description of the drawings]

FIG. 1 is an overall system configuration diagram of a hot air heater according to an embodiment of a first aspect of the present invention.

FIG. 2 is a block diagram of a main part of the hot air heater of the embodiment of FIG. 1;

FIG. 3 is a diagram showing a set rotation speed, a lock rotation speed, and a release rotation speed of the hot air heater of the embodiment of FIG. 1;

FIG. 4 is a flowchart for explaining the operation of the warm air heater of the embodiment in FIG. 1;

FIG. 5 is a diagram showing a predetermined time for detecting an abnormality of the hot air heater according to the embodiment of the second aspect of the present invention;

FIG. 6 is a diagram showing a lock rotation speed and a predetermined time for detecting an abnormality of the warm air heater according to the embodiment of the third aspect of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Body case, 3 ... Blow fan, 4 ... Gas burner (combustor), 16 ... Rotation speed sensor, 30 ... Combustion control part, 31
... Fan control unit, 32 ... Abnormality detection unit, 33 ... Fan lock detection timer, 34 ... Fan lock release timer

Continued on the front page (72) Inventor Tsutomu Kakeno 2-26, Fukuzumi-cho, Nakagawa-ku, Nagoya-shi, Aichi Prefecture Inside Rinnai Corporation (72) Inventor Kazuki Nishio 2-26, Fukuzumi-cho, Nakagawa-ku, Nagoya-shi, Aichi Prefecture Inside (72) Inventor Tomoya Akahori 2-26 Fukuzumi-cho, Nakagawa-ku, Nagoya-shi, Aichi F-term (in reference) 3N003 AA01 AA08 AB02 AB06 AC07 BB00 BC06 CA03 CC04 JA06 KA04 KB02 LA06 NA04 NA07 3L028 EA01 EB01 EC02 ED04

Claims (7)

[Claims] 1. A combustor housed in a main body case, a fan for taking air into the main body case and discharging air heated by the combustor to the outside of the main body case, a combustion amount of the combustor Combustion control means for controlling the number of revolutions of the fan, a fan control means for setting the number of revolutions of the fan according to the amount of combustion of the combustor, a revolution number sensor for outputting a signal corresponding to the number of revolutions of the fan, Abnormality detection means for detecting abnormality of the fan when it is recognized that the rotation speed of the fan has become equal to or less than a predetermined lock rotation speed lower than the set rotation speed based on a signal of the sensor, A hot-air heater, wherein the lock rotation speed is provided for each set rotation speed corresponding to the combustion amount, and the difference between the set rotation speed and the lock rotation speed is reduced as the combustion amount increases. 2. A combustor housed in a main body case, a fan for taking air into the main body case and discharging air heated by the combustor to the outside of the main body case, a combustion amount of the combustor Combustion control means for controlling the number of revolutions of the fan, a fan control means for setting the number of revolutions of the fan according to the amount of combustion of the combustor, a revolution number sensor for outputting a signal corresponding to the number of revolutions of the fan, Abnormality detecting means for detecting an abnormality of the fan when it is recognized that a state in which the rotation number of the fan has become lower than the set rotation number by a certain number of rotations or more based on a signal of the sensor has continued for a predetermined time. A warm air heater, wherein the predetermined time is provided for each set number of revolutions corresponding to the combustion amount, and the predetermined time is shortened as the combustion amount increases. 3. A combustor housed in a main body case, a fan for taking air into the main body case and discharging air heated by the combustor to the outside of the main body case, a combustion amount of the combustor Combustion control means for controlling the number of revolutions of the fan, a fan control means for setting the number of revolutions of the fan according to the amount of combustion of the combustor, a revolution number sensor for outputting a signal corresponding to the number of revolutions of the fan, Abnormality detecting means for detecting abnormality of the fan when it is recognized that the state in which the rotation number of the fan has become equal to or less than a predetermined lock rotation number lower than the set rotation number has continued for a predetermined time based on a signal of the sensor. In the warm air heater provided, a plurality of the lock rotation speeds having different values are provided for each of the set rotation speeds, and the predetermined time is provided for each of the lock rotation speeds, and the lower the lock rotation speed is, the more the corresponding is. Do Warm air heater, characterized in that shortened the serial predetermined time. 4. The combustion control means according to claim 1, wherein when the abnormality detection means detects an abnormality of the fan, the combustion control means reduces the combustion amount of the combustor or stops the combustion. A warm air heater according to any one of the preceding claims. 5. When the abnormality detecting means detects an abnormality of the fan, the combustion control means reduces the amount of combustion of the combustor, and thereafter, the abnormality detecting means detects the abnormality based on a signal of the rotation speed sensor. When it is recognized that the rotation speed of the fan has become equal to or higher than a predetermined release rotation speed provided for each set rotation speed at the time of the abnormality detection, the combustion control means detects the combustion amount of the combustor in the abnormality detection. The hot air heater according to any one of claims 1 to 3, wherein the amount of combustion is returned to the combustion amount at the time. 6. The rotation speed sensor outputs a pulse signal according to the rotation speed of the fan, and the abnormality detecting means measures a pulse interval time of the rotation speed sensor pulse signal a plurality of times, The hot air heater according to claim 1, wherein the number of revolutions of the fan is recognized based on an average value of the measured values. 7. The rotation speed sensor outputs a pulse signal corresponding to the rotation speed of the fan, and the abnormality detecting means measures a time of a pulse interval of the pulse signal of the rotation speed sensor, and measures the time. 3. The system according to claim 2, wherein the number of revolutions of the fan is recognized based on the value.
Or the warm air heater according to 3.