JPS6077800A - dryer control device - 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 control device for a drum-type dryer or the like that supplies hot air to dry clothing or the like.

Conventional structure and its problems Generally, when drying clothes, the drying time varies depending on the amount and type of cloth, so conventional dryers use a timer to set the appropriate drying time based on the user's intuition and experience. Was.

However, if the setting time of the timer is incorrect, the cloth may become over-drying, resulting in higher power consumption than necessary, damaging the cloth, or leaving the cloth completely undryed.

In addition, there is a method to automatically detect the end of drying by detecting the resistance value of the cloth, but since the resistance value of the cloth surface is detected with an electrode, in the case of thick cloth, the cloth Even if the area was dried, there was a risk that the overall condition would be undried.

Also, if the amount of cloth is small, the cloth may not fit the electrode, and the cloth may not dry properly.1. jjlj 1 [L < 4 Vumi did not come out. Furthermore, since the method detects the surface resistance of cloth, it is necessary to detect a very high resistance value, which poses some problems with the circuit.

OBJECT OF THE INVENTION The present invention solves the problems of the prior art described in -1-, and provides a control device for a dryer that can reliably and inexpensively detect a specified drying rate regardless of the +Φ type of fabric or the amount of fabric. It is to be provided.

Composition of the Invention The dryer control device of the present invention includes an exhaust gas temperature detection device, an operating time counting device, and an arithmetic control device. The rate of change over time in the exhaust gas temperature is determined, and the rate of change in the exhaust temperature is compared with the results calculated by the arithmetic and control unit based on the operating time determined by one device, and the drying control is performed. Moreover, it reliably detects the specified drying rate.

Indeed, the dryer control device of the present invention includes an exhaust temperature detection device and an arithmetic control device, calculates temporal changes in exhaust temperature, and performs drying control by comparing the rate of change with a prescribed constant. This is a device that reliably detects the specified drying rate.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention will now be described with reference to the accompanying drawings. In FIG. 1, reference numeral 1 denotes an exhaust temperature detection device that detects the exhaust temperature of the dryer. Divide the operating time of the dryer from the start of operation using a 2-digit operating time counting device. 3 is an arithmetic and control device that receives the output of the exhaust gas temperature detection device 1, calculates temporal changes, and calculates the rate of change in the exhaust gas temperature. In addition, the arithmetic and control device 3 accepts the output of the operation time counting device 2,
Calculate the operating time by putting it into a prescribed function, compare the rate of change in the exhaust gas temperature and the calculated value of the operating time, and based on the results,
The heater 4 or motor 5 of the dryer is stopped or continues to be operated.

Figure 2 shows how the exhaust temperature changes as drying progresses.

The period t1 is a drying period of -14A, and the applied heat does not contribute sufficiently to drying, and the exhaust temperature rises rapidly. The period t2 is constant rate drying 1υ],
The increased heat is taken away by the latent heat of vaporization of water, and the -11 temperature becomes constant. This is the most efficient way to dry. period t
3 is the lapse rate drying period, the cloth is almost dry and the temperature rises.

FIG. 3 shows the relationship between exhaust temperature and time depending on the amount of cloth, and FIG. 4 shows the rate of change of exhaust temperature ΔT/Δt corresponding to FIG. 3.

In FIGS. 3 and 4, A indicates when the amount of fabric is large, B indicates when the amount of fabric is medium, and C indicates when the amount of fabric is slightly small.

When the amount of cloth is large, the rate of change in the preheating drying period and the decreasing rate drying period is small and the constant rate drying period is long, so the exhaust temperature change rate ΔT
/Δt is small. When the amount of cloth is small, the rate of change in the preheating drying period and the decreasing rate drying period is very high, and the constant rate drying period is short, so the exhaust temperature change rate ΔT/Δt is large. When the amount of cloth is medium, B is in the middle.

In Fig. 4, points P1' to P3 where the drying rate is about -IO
' and draw a straight line 6, each point P1' to P3' becomes a point P1 to P3 where the constant rate drying period shifts to the decreasing rate drying period. The equation of this straight line 6 can be expressed as ΔT/Δt=At+B (A, B constants). What this formula means is ΔT/Δt
When is small, t is long and the amount of cloth is large. Also Δ
When T/Δt is large, t is short and the amount of cloth is small.

As described above, data on the exhaust gas temperature T is input from the exhaust gas temperature detection device 1 to the arithmetic and control device 3, and the arithmetic and control device 3 calculates the rate of change ΔT/Δt of the exhaust gas temperature. Further, the data of the driving time t is input from the driving time counting device 2 to the arithmetic and control device 3, and the arithmetic and control device 3 calculates At1B. Then, the arithmetic and control unit 3 determines the condition t such that B/It≧−At+B, and detects the drying rate of 9o.

Also, during the preheating drying period, the exhaust temperature rises rapidly, and ΔT/Δ
Since the condition of t≧−At1B is satisfied and a false detection occurs, the operation of the exhaust temperature detection device 1 is stopped during the preheating drying period. Although a straight line 6 intersecting the exhaust gas temperature change rate curve is drawn in FIG. 4, a curved line may be drawn instead.

FIG. 5 shows the case where the hyperbolic curve 7 is drawn.

A indicates a large amount of fabric, B indicates a medium amount of fabric, and C indicates a small amount of fabric. Hyperbolic curve 7 is (10σ)・ΔT/Δl=
It can be expressed as C (σ, C constant).

If the rate of change in the exhaust temperature rise during the preheating drying period does not intersect with the hyperbolic curve 7, then the specified time from the start of operation
There is no need to worry about stopping the antistatic temperature detection device 1.

FIG. 6 shows the case where the rate of change of the air temperature is constant (5). In this example, the operating time numeral device 2 shown in FIG. 1 is not required. ΔT/Δ can be expressed as -K (K constant) when A is a large amount of cloth, B is a medium amount of cloth, and C is a small amount of cloth. At this time, the operation of the exhaust temperature detection device 1 must be stopped during the preheating drying period.

The points where the detection formula (E + σ) x ΔT/Δt=C and ΔT/Δt- intersect with the exhaust temperature change rate curve, P1', P
2' and P3' are approximately at a drying rate of 90 at the time of transition from the constant rate drying period to the decreasing rate drying period.

As described above, since a predetermined drying rate is calculated from the rate of change in the exhaust gas temperature of the dryer, it is possible to perform inexpensive and reliable dryness detection with less influence from the ambient temperature.

Effects of the Invention The dryer control device of the present invention measures the rate of change in the exhaust gas temperature of the dryer, and detects dryness when the rate of change is a value calculated from the operating time of the dryer or exceeds a specified constant. It only requires one sensor, can detect dryness with absolute certainty, and is inexpensive and reliable.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a control device showing an embodiment of the present invention, Fig. 2 is a characteristic diagram showing changes in exhaust temperature of a dryer, and Fig. 3 is a characteristic diagram showing changes in exhaust temperature depending on the amount of cloth. , Figure 4 is a time-exhaust temperature change rate characteristic diagram obtained by dividing the exhaust temperature change in Figure 3 by the rate of change in unit time roar, and Figure 5 is a time-exhaust temperature change rate different from Figure 4. FIG. 6 is a characteristic diagram of time-exhaust temperature change rate showing another example of the present invention. 1 Exhaust temperature detection device, 2 ・-operating time S] several devices,
3 - Arithmetic control device. Name of agent: Patent attorney Toshio Nakao (1st person)
Figure 2 Figure 3 Verse closing Figure 4 Special MtJ Procedural amendments Dear Commissioner of the Patent Office 1 Display of the case 1986 Patent Application No. 186270 2 Name of the invention Control device for dryer 3 Name to be amended. 1006 Kadoma, Kadoma City, Osaka Name (582) Matsushita Electric Industrial Co., Ltd. 1, 11i Toshihiko Shimo 4 Agent 571 Address Osaka 6, Matsushita Electric Industrial Co., Ltd., 1006 Oaza Kadoma, Kayakoma City, page 5, line 19 of the statement of contents of the amendment, “ΔT/Δt = A t+B
Correct J to [ΔT/Δ to -At+BJ.

Claims (4)

[Claims] (1) An exhaust temperature detection device that detects the exhaust temperature of the dryer, an operation time counting device that counts the operating time of the dryer from the start of operation, and an exhaust temperature detection device that calculates the exhaust temperature based on the output of the exhaust temperature detection device. A dryer control device comprising: a calculation control device that performs drying control by comparing the rate of change with a calculated value of the operating time calculated in response to the output of the operating time counting device. (2) The control device for a dryer according to claim 1, wherein the exhaust temperature detection device is configured to stop operation during a preheating drying period. (3) Consisting of an exhaust temperature detection device that detects the exhaust temperature of the dryer, and a calculation control device that performs drying control by comparing the rate of change in the exhaust temperature calculated based on the output of the exhaust temperature detection device with a prescribed constant. Dryer control device. (4) The dryer control device according to claim 3, wherein the bleed air temperature detection device stops the preheating drying time operation.