JPS61275017A - Air cooling apparatus for automobile - Google Patents

Abstract

PURPOSE:To aim at protection of auxiliary machinery at the time of lock occurrence in a compressor, by constituting a transfer relationship between an engine and the compressor so as to be released if a revolving speed pulse of the compressor is less than the setting value at a time when the detecting pulse number of engine revolving speed reaches to the setting value. CONSTITUTION:Both revolving speeds of an engine 1 and a compressor 2 are detected each by photo-couplers S1 and S2, converted into a pulse number each by pulse generating circuits P1 and P2, and pulse counters C1 and C2, and inputted into a control unit 7 which compares the pulse number C2 of the compressor 2 with the compressor setting value when the pulse number C1 to an engine speed is reached to the setting value. And, when it is below the setting value, a solenoid clutch 5 is turned off, cutting off the rotational driving relationship between the engine 1 and the compressor 2. With this constitution, protection of engine auxiliaries is well promoted.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an automobile cooling system, and more particularly to an automobile cooling system that protects engine accessories when a lock occurs in a cooling compressor.

(Prior art) As a conventional device of this type, for example,
No. 1214'' is disclosed in the publication.

In this conventional device, when the compressor locks and stops due to various reasons such as a decrease in the effectiveness of the lubricating oil, in order to prevent the induction of secondary failures in the engine auxiliary equipment such as the generator and the electromagnetic clutch, The following configuration has been adopted. That is, the rotational speed of the engine and the rotational speed of the compressor to which engine drive is transmitted via the electromagnetic clutch are detected as pulse signals, respectively.
After both detection pulses are converted from frequency to voltage (F/V conversion), a comparison is made to see if the ratio of both converted values is less than or more than a set ratio. When the converted value ratio falls below the set ratio, even though this phenomenon is caused by a transient disturbance such as an engine noise pulse, the electromagnetic clutch is erroneously released immediately. Preventive measures against judgment are taken. In other words, if a predetermined period of time has elapsed since a condition below the set ratio was detected, and the condition continues beyond this predetermined period, it is determined that a so-called slipping phenomenon has occurred in the electromagnetic clutch. A circuit is provided. In this delay circuit, the operation of the electromagnetism and latch is canceled by the determined control signal.

(Problems to be Solved by the Invention) However, in the above-described conventional apparatus, F/V conversion is necessary to detect and compare the respective rotational speeds of the engine and the compressor. Therefore, in the low engine speed rotation range, even if the delay circuit exceeds a predetermined time, the judgment is delayed, and the detection response is not good, such as the release command not being issued to the electromagnetic clutch.Also, due to engine noise pulses, etc. Since a predetermined elapsed time is set to prevent misjudgment, the problem is that if the compressor locks up during that time, the electromagnetic clutch and transmission belt will slip, leading to damage or burnout. be.

The present invention was made to solve the problems of such conventional devices, and has excellent responsiveness in the drive side engine from low speed operation range to high speed operation range, and has excellent responsiveness in the drive side engine auxiliary equipment etc. The purpose of this invention is to provide a cooling system for automobiles that can reliably prevent burnout and the like.

(Means for Solving the Problems) To achieve this objective, the automotive cooling device according to the present invention provides an automotive cooling system in which the rotational drive of a driving engine is transmitted to a passive compressor via a transmission member. The device detects and converts each rotational speed of the engine and the compressor into pulses, and when the number of engine pulses reaches a set number, the actual number of pulses in the compressor is equal to or less than the set number of the compressor. At times, the transmission member is deactivated by a control signal from the control means.

(Example) Hereinafter, an example of an automobile cooling device according to the present invention will be described with reference to the drawings.

In FIG. 1, 1 is an engine on the drive side, 2 is a cooling compressor on the passive side, and a transmission belt 3 is a transmission member.
The rotation of the engine 1 is transmitted via the electromagnetic clutch 4. Reference numeral 5 designates an engine auxiliary machine such as a generator to which the rotation of the engine 1 is transmitted via an electromagnetic clutch 4 and a transmission belt 6, which are transmission members. Sl and S8 are rotation detection sensors such as photocouplers that detect the rotation speeds of the engine 1 and the compressor 2. p! , p is a rotation detection sensor S, a pulse generation circuit that converts the rotation speed detection signal from S2 into a pulse, and C, C2 is a pulse generation circuit p,
, p2.

In addition, in the control unit 7 using a microcomputer, the count value of each pulse number is inputted from the pulse counting counters Cyu and C2, and each pulse setting number of each of the engine 1 and the compressor 2 is stored in the memory. A comparison calculation is made between n1 and n2, and this control signal is output to the electromagnetic clutch 4. Note that 8 is a main switch called an air conditioner switch connected to the vehicle battery.

Next, the operation of the apparatus of the embodiment will be explained in the order of steps F based on the flowchart of FIG.

When the main switch 8 is turned on while the car is running, each pulse counter c1, C2 on the engine 1 and compressor 2 side is reset (step F1), and the rotation by the one-rotation detection sensors SL, S is detected. The detection signal is converted into pulses in the pulse generation circuits pi and p, and each pulse is sent to a pulse counting counter C and C.
2 starts counting (step p z ).

It is determined whether the measured pulse number of engine 1 has reached the set number n1, that is, whether the data variable I = 1 (binary number) (step F,), and when the measured pulse number is 〉n□ Then, pulse counting by the pulse counting counter C0 on the engine 1 side is stopped (step F4).

Here, a flag instruction signal of I=1 in the engine 1 is applied from the control unit 7 to the pulse counting counter c2 on the compressor 2 side which is currently counting (step F5), and the pulse counting by the pulse counting counter C2 is stopped (step F5). F.). Then, the control unit 7 compares the measured number of pulses at this time with the set number n2 of pulses on the compressor 2 side (step F7). In other words, the number n of pulses set on the engine 1 side is a flag that instructs the timing to compare the actually measured number of pulses with the number n2 of pulses set on the compressor 2 side. Therefore, the number n2 of pulses set on the compressor side is This is for comparison with the actual number of pulses measured.

In step F7, it is determined whether the actually measured number of pulses on the compressor 2 side is larger or smaller than the set number n2, and if the actually measured number of pulses is not >n2, the OU of the control unit 7
A control signal is output from the T port, and the operation of the electromagnetic clutch 4 is canceled by this control signal. That is, upon determining that a slipping phenomenon has occurred in the compressor 2, the electromagnetic clutch 4 is turned off to release the drive transmission from the engine 1 to the compressor 2 and the engine auxiliary equipment 5 (step F).

Note that when the actual measured pulse number on the compressor 2 side is > n2 with respect to the set number n2, a reset signal is given to each pulse counting counter C1 and C3 of the engine 1 and compressor 2 by the I=O flag, and the pulse count is again Counting is performed (step F4).

In this way, in the case of the device of the embodiment, the number of revolutions of the compressor 2 is counted as a pulse, so compared to the conventional speed detection using F/V, transient disturbances such as engine noise and pulses are detected. avoids misjudgment and does not require a predetermined elapsed time. Therefore, there is no fear that slippage in the electromagnetic clutch 4 will increase during this predetermined time.

Furthermore, as the engine 1 rotates in a higher speed range, the pulse setting number n3 on the compressor 2 side is counted in a shorter time, so even if the compressor 2 locks,
By quickly responding to this, it is possible to take early steps to protect the engine auxiliary equipment 5 and the like. On the other hand, the engine rotation is in the low speed range (
(knocking, etc.), the pulse counting time becomes longer, so that erroneous judgments such as unnecessary release of the electromagnetic clutch 4 will not occur.

In this way, the electromagnetic clutch 4 is disengaged when the minimum slippage occurs in the compressor 2 over a wide range from the low speed range to the high speed range of the engine 1.
High accuracy of protection for engine auxiliary equipment 5, etc.

(Effects of the Invention) As can be understood from the above, according to the automotive cooling system of the present invention, the passive side compressor can be operated over a wide range from the low speed operation range to the high speed operation range of the drive side engine. It has excellent responsiveness in detecting slippage, and the drive transmission is immediately canceled after a malfunction is detected, so that the transmission members including the transmission belt are reliably prevented from being burnt out and the engine auxiliary equipment is protected.

[Brief explanation of the drawing]

FIGS. 1 and 2 show an embodiment of an automobile cooling system according to the present invention, with FIG. 1 being a schematic structural diagram thereof and FIG. 2 being a flowchart of its operation. 1...Engine. 2... Compressor, 4... Electromagnetic clutch. 5...Engine auxiliary equipment such as generator, 7...
... Control unit, Sl, S2 ... Rotation detection sensor. C2...Pulse counting counter.

Claims (1)

[Claims] A cooling device for an automobile in which the rotational drive of a driving engine is transmitted to a passive compressor via a transmission member, wherein the respective rotational speeds of the engine and the compressor are detected and converted into pulses, and the engine pulses are detected and converted into pulses. When the number of pulses reaches a set number and the actual number of pulses in the compressor is equal to or less than the set number of the compressor, the operation of the transmission member is canceled by a control signal from a control means. Cooling device.