JPS59118522A - Automatic contact breaker in onboard compressor - Google Patents

Abstract

PURPOSE:To aim at prolonging the life of a clutch for a compressor, by providing such an arrangement that the compressor is mechanically isolated from an internal combustion engine upon acceleration of a vehicle, but the compressor is restarted, upon returning of the internal combustion engine to its constant rotational speed condition, after a predetermined time delay is elapsed. CONSTITUTION:A rotational speed signal taken out from a primary side negative terminal 5 in an ignition coil 1 is delivered through a wave-shaping circuit 6 to a frequency-modulation circuit 10 for issuing a pulse train signal which is frequency-modulated in proportion to the detected rotational speed and which has a constant pulse width PW. This pulse train signal is then delivered to a changing direction detecting circuit 23 after it is converted into a voltage signal in a frequency/voltage converter circuit 16, so that whether the rotational speed of the engine is in its increasing mode or not, is discriminated. The above-mentioned circuit 23 delivers its output signal to a setting circuit 42 for setting a returning time period of the compressor function to set a time delay upon restarting of the compressor. Thereafter, a compressor breaker circuit 41 is controlled in accordance with the output of the above-mentioned circuit 42, thereby energization to an electromagnetic clutch 33 is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a compressor for an air conditioner or a car cooler that utilizes a vehicle propulsion internal combustion engine as its mechanical drive source when the vehicle is accelerated, that is, when the internal combustion engine rotational speed is increasing. At the same time, while mechanically separating J from the internal combustion engine,
This invention relates to a compressor automatic disconnection device for use in a vehicle, which allows a sufficient amount of time for the compressor to recover its function even after returning to a constant speed rotation state.

Compressors for air conditioners and car coolers generally use the internal combustion engine used to drive the vehicle as their mechanical drive source. Particularly when accelerating a vehicle, which requires high efficiency from the internal combustion engine, there are complaints that the power loss slows down acceleration performance.

Therefore, in order to solve this dissatisfaction, conventional methods have been used to detect the negative pressure generated in the internal combustion engine's intake/genifold during acceleration, and mechanically activate the sochi, an electromagnetic crane placed between the internal combustion engine and the compressor. A device that attempts to disconnect it from an internal combustion engine has already been put into practical use.

However, this method, which uses pressure-sensitive elements or vacuum switches, requires a special configuration and effort to install, and cannot be installed as is without modifying the existing manifold structure. Therefore, it had the drawback of requiring a special design and lacking in versatility.

In addition, pressure-sensitive elements are exposed to high heat and corrosive environments, so
This required countermeasures, and there was also the disadvantage of having to start manufacturing from a dedicated element.

Furthermore, with conventional devices like this, the compressor was reconnected immediately after the acceleration state ended, so when driving outside the city, especially when starting and accelerating frequently, such as in low-speed traffic jams, the compressor has to be connected frequently each time. repeated intermittent and therefore i! with internal combustion engine! There was a drawback that the compressor launch which adopted l-interconnection was subject to significant wear. This drawback is also undesirable from a mechanical stress point of view.

The present invention has been made in view of the following two points, and it electronically detects the acceleration driving mode of the vehicle or the rotation speed increasing mode of the internal combustion engine, and stops the function of the compressor when in this mode. It is an object of the present invention to provide a simple device for mechanically disconnecting a compressor from an internal combustion engine, and to prevent the compressor from immediately re-functioning even if the acceleration mode or rotation speed increasing mode is changed to a constant speed rotation mode,
This is intended to reduce the number of times the compressor clutch is engaged and engaged in the driving state where the acceleration/deceleration intervals are short as described above, thereby extending the life of the clutch and the mechanical system.

Hereinafter, one embodiment of the present invention will be described with reference to the attached preferred embodiment.

In the device of this embodiment shown in FIG. 1, first, the rotational speed signal of the internal combustion engine is extracted from the primary negative terminal 5 of the ignition coil 1, which forms part of a known ignition device. That is, each time the primary current path of the ignition coil is interrupted as is well known, an impulse of several hundred ports is generated at the negative terminal 5 of the secondary coil, and the pulse repetition period or signal The frequency is proportional to the engine speed.

FIG. 2(A) shows this impulse signal S1, and as shown from time T1 to T2, when the engine is rotating at a constant speed, each impulse rising from the reference potential Eo (generally ground potential) also , the pulse interval, that is, the frequency, is constant, but as shown from time T2 to time T3, when the engine is in the process of increasing the rotational speed, the frequency also increases. In addition, in Fig. 2 (A), the time axis is viewed from time T3 toward the left hand side, and as the engine speed decreases from time T3 to time τ4, the pulse interval gradually decreases. It spreads (that is, the frequency also decreases), and eventually, when it reaches a constant rotation range from time T4 to time T5, the frequency becomes constant again. Of course, even if we say that the frequency is constant in the constant rotation range,
If the rotational speed is different, the value of the frequency is also different.

Therefore, the illustrated case shows a constant rotation, for example, starting from idling, going through an upward and downward process, and then returning to the previous constant rotation. However, as will become clear from the description below, in the present invention, the absolute value at constant rotation is not a problem, but only whether it is in the process of increasing or increasing. Fully generalizable.

In addition, as mentioned in advance, in the waveform diagrams of the main parts from (A) to (D) in FIG. It is shown in
On the other hand, in FIGS. 2(E) to 2(G), this is expanded as it is on the right hand side on the time axis t, and a constant rotation range up to time T3' which extends to time T3 is added.

Now, the above-mentioned impulse signal St whose frequency changes in accordance with the engine speed is too high in terms of analog level to be treated directly as an engine speed signal, and there are too many noise components. Therefore, it is preferable to first shape the waveform in the waveform shaping circuit 6 after applying it to the input In of this device.

In the illustrated case, after the signal Sl applied to the input In is clipped by the Zener diode 8 to prevent excessive input,
npn) is input to the base of the Langistaff, and its collector is used as the waveform shaping output 9, from which a clean waveform of the engine speed signal S2 is extracted. As shown in FIG. 2(B), this waveform is caused by the potential of the power supply battery 4 due to the inverter function of the NPN transistor 7, each time the key switch 3 is closed and the ignition coil performs a current cutoff operation. It is assumed that the voltage goes from Eb (this is set as a high level H) to a reference potential, in this case, the ground potential Eo (this is set as a low level L).

In order to make this signal S2 into a pulse train signal that is easier to handle, a constant width pH signal that is frequency-modulated in proportion to the engine speed is
The signal is input to a conversion circuit or a pulse frequency modulation circuit IO that generates a pulse train signal. In this embodiment, a monostable multi-occurrer 11 is used as the main component of this circuit,
Every time the above-mentioned signal S2 is applied to the trigger input +3, it is triggered by its high/low transition, and a constant width P is output to the output terminal 14.
A W pulse appears. Although the pulse width 21 is uniquely determined according to the time constant of the external resistor 15 and capacitor 17, the frequency of the pulse train signal S3 is proportional to the engine speed.

This pulse train signal is then input to a frequency-to-voltage conversion circuit 1B whose output voltage changes in accordance with frequency changes. In this embodiment, the conversion circuit 16 has the simplest configuration as a ripple filter or integration circuit consisting of a capacitor 19, 20 and a resistor 21, and a pulse train signal is inputted to this circuit after passing through a diode 18. .

This integral circuit! As shown schematically and simply linearly in FIG. When it rises, it rises from that level, and when it falls, it falls along with it.

This converted voltage output S4 is given to a change direction detection circuit 23 including a two-person power comparator 22. One feature of this embodiment is that the comparator 22, which is commonly used, can be used in the change direction detection circuit 23, thereby providing the ability to detect the change direction based on the time constant relationship in the internal input. .

That is, the voltage output S4 is given to both the positive input (non-inverting input) 31 and the negative input (inverting input) 30 of this comparator 22, but each input is given a voltage with a different time constant.
, τ is held.

In this embodiment, an open collector type output is used for the comparator 22, and as will be described later, when the positive input exceeds the negative input at the analog level, the signal S7 at the output 32 is output at the digital level. High level H (logic “1゛°)
Therefore, the time constant 1 given to the positive input side is selected to be smaller than the time constant τ2 of the negative input side (τ1 × τ2). Specifically, in this case, each time constant is determined by each input integrating circuit (resistor 26 and capacitor 27).
; formed by a resistor 29 and a capacitor 28), and
A level shift diode 24 is inserted in the line to the positive input 31 for reasons described later.

Below, if we follow the operation according to the schematic diagram of changes in engine speed in Fig. 2 (E), as shown from time TI to time T2, when the engine is rotating at a constant speed, As described above, at the output terminal 24 of the frequency-to-voltage conversion circuit 16, a signal S4 of an analog level Va corresponding to the rotational speed at that time appears.

If this state continues for a relatively long time, the capacitors 27 and 28 of both comparators will be fully charged and the potential will be stabilized. In this state, however, the capacitor 27 on the negative input side will be approximately C1 While the capacitor 28 on the positive input side is charged to the voltage value Va at this time, the forward voltage drop V of the inserted level shift diode 25
The level becomes low by t. Thereafter, the average voltage of the potential across the capacitor is grasped as a signal over time, and the input voltage on the positive input side of the comparator is set to 95. If the input voltage on the negative input side is expressed as 86, the relationship between both signal potentials between times TI and T2 can be schematically expressed linearly as shown in FIG. 2 (
F).

Therefore, during this constant speed rotation, the comparator negative input side potential is higher than the positive input side, so the signal S7 at the output terminal of the comparator 22 is at a low level (the open collector transistor is turned on and the output terminal or collector conductive to ground).

Next, in FIG. 2(E), the engine speed is from time 72 to
During the process of rising or increasing as shown in FIG. 2(D), the frequencies of the rotational speed signals St to S2 and, as a result, the frequency of the vibrator output signal S3 increase, so the output S4 of the integrating circuit 16 is as shown in FIG. 2(D). As described above, the potential begins to rise. Therefore, both the capacitors 27 and 28 of the input in the comparator are charged toward a higher voltage value, but as mentioned above, the positive input time constant τ1 including the capacitor 28 is higher than 2. Therefore, in such a transient state, even if there is a voltage drop due to the intervention of the diode 25, the potential of the positive input side signal s5 exceeds the potential of the negative input side signal S6, as shown in FIG. 2(F). Therefore, the comparison output signal s7 is inverted and becomes H level as shown in FIG. 2(G).

At time 13, the transient state of acceleration or rotational speed rise is over.
When the engine speed becomes constant at a high level as shown by ~T3', both capacitors 27 and 28 are fully charged again, and the previous output potential of the integrating circuit 16 is changed to V.
b, as before, the potential of the comparator negative input terminal signal s4 is approximately 1''vb, whereas the signal potential on the positive input side is V lower by the forward voltage Vt of the level shift diode 25.
Since the voltage becomes b-Vt, the output of the comparator is reversed again and becomes L level.

Next, as shown at times T3' to T4 in FIG. 2(E),
When the engine speed enters a transient state where it decreases, the integration circuit 16
The converted voltage output S4 is as shown in Fig. 2 (D) by the mechanism described above.
As shown in the image, a downward transition occurs as seen on the left hand.
Therefore, the capacitor input to the comparator enters the discharging process, but from the time constant relationship mentioned above, the discharge on the positive input side is always faster, so in that transient state, the relationship does not change from the constant speed rotation to the two-power relationship. Therefore, the comparator output is L as shown in Figure 2 (G).
It will maintain the level.

It is already clear that this condition does not change even after the deceleration transition period ends and the engine enters the constant speed rotation range (times T4 to T5) with a reduced rotation speed again.

The correlation between the above comparator output S7 and each state mode of the internal combustion engine, that is, constant speed mode, increasing mode, and decreasing mode, is as shown in Table 1 below.

Engine rotation state> As a result, it can be seen that the comparator output s7 of this device has the ability to discriminate between the engine rotation speed increasing mode and the other mode (constant speed, decrease).

Therefore, this comparator output s7 is then applied to the compressor function recovery time setting circuit 42. As stated in advance, at this return, the output sl of the 11JI setting circuit 42
As shown in Fig. 2 (1), o rises from L level to H level almost simultaneously with comparator output S7, but falls under the driving condition with heavy acceleration and deceleration as mentioned at the beginning. The fall of the comparator output S7 is delayed by an appropriate amount. The operation of the recovery time setting circuit 42 in this embodiment will be explained below.

In the non-acceleration mode, when the output S7 of the comparator 22 is at L level, the input npn) transistor 4 of the circuit 42
3 is in the off state. If this state continues to a certain extent, the capacitor 45 inserted between the negative phase input or inverting input of the open collector type comparator 50 similar to the comparator 22 and the ground becomes variable for reasons described later. It is charged to approximately C power supply potential Eb through a resistor 44 that is connected to the power source. On the other hand, the positive phase input side of this comparator 50 has a resistor 47,
48 receives the divided voltage output of the voltage divider. If this divided voltage output is 88, it provides the reference potential Es to the comparator. This reference potential Es has at least a linear relationship with respect to the power supply potential Eb.

Eb>Es (1) Therefore, in a non-accelerating state, the output SIO of this comparator 50 is L
level, i.e. grounded.

According to the mechanism described above, the acceleration mode is entered and the output S7 of the comparator 22 becomes H as shown in FIG. 2(G).
When the level is reached, the base potential is applied to the base of the input transistor 43 of the return time setting circuit 42 via a bias circuit including resistors 49 and 49', and this transistor 43 becomes conductive.

As a result, the charge accumulated in the capacitor 45 is rapidly discharged through the resistor 46 having a relatively small resistance value, and as shown in FIG. The potential of the signal S8 on the other input side rapidly falls below the reference potential Es, and the output S10 of the comparator 50
As shown in FIG. 2(1), the signal rises to H level similarly to the signal S7.

This time is indicated as time T2' in FIG.

Next, as mentioned above, after the acceleration mode is finished, the comparator 22
Assuming that the output of the circuit 42 falls as shown at time T3'' in FIG. It takes time for the signal S8 to exceed the reference voltage Es, and it is not until the potential of the signal S8 exceeds the reference potential at time TD in FIG. 2 (H) that the comparator 5
The output SlO of 0 returns to the L level.

As is clear from this function, this circuit 42 has a kind of monostable multivibrator function. The only difference is that the duration time tm of the H level is not constant, but changes depending on the time tx during which the output of the comparator 22 is at the H level, that is, the acceleration time (tm = tx + td; ). However, the time td from the end of the acceleration state to the fall is constant. This time td can be adjusted by a time constant formed by the resistor 44 and capacitor 45. For this purpose, as shown in FIG. 1, the resistor 44 is made a variable resistor so that the delay time can be arbitrarily and appropriately set. Of course, the capacitor 45 can be a variable capacitor, but a resistor is actually more advantageous. However, if the resistor 47 or 48 in the voltage dividing circuit that forms the reference potential Es is a variable resistor,
This reference potential Es may be adjusted.

In any case, as long as the recovery time setting or delayed output SIO as described above can be obtained, by processing this appropriately, the machine can be connected between the compressor and the engine only when this signal Slo is at H level. Those skilled in the art will be able to easily think of a configuration in which the two parts are separated separately.

In this embodiment, as an example of such a flanch intermittent circuit 41, an electromechanical relay 33 is selected as a driver of an electromagnetic clutch that mechanically connects the compressor and the engine directly at the logic level of the comparator output SIO. The magnet is demagnetized and the power supply path to the electromagnetic clutch 35 is selectively cut off. That is, the power supply line 12 and the comparator output terminal 32
A driver relay 33 is inserted in series between them, and its meter contact 34 is inserted into a power supply line 39 that runs from the power line 12 to the operating winding 35a of the electromagnetic clutch 35, so that the engine speed is constant and constant. When in the drop mode, the comparator output S7 is at the L level, which creates a potential difference that causes an operating current to flow across the relay 33, so that the relay 33 is energized and the make contact 34 is closed.
A current flows through the operating winding 35a of the electromagnetic clutch 35 to connect the clutch, and the compressor is driven by the engine. However, when the vehicle requires acceleration and the engine speed increases, the comparator output S7 As a result, the potential difference between both ends of the driver relay is lost due to the reversal of the output of the return time setting circuit 42 to the H level, and therefore, the make contact 34 is opened and the current to the electromagnetic clutch operating winding is cut off, and the electromagnetic clutch is turned off to the engine. Mechanically shut off the drive system. Even after the acceleration is finished, this state can be maintained until the predetermined time td has elapsed.

The above clutch operation is also shown in parentheses in FIG. 2(I). Further, the light emitting diode 3B is used for monitoring this operation. However, since this indicator light 36 lights up when the clutch is engaged, it is better to indicate to the driver when the clutch is disengaged in accordance with the idea of the present invention. As shown by the virtual line in Figure 1, −
diode 36 using break contact 34b of loop 33.
It is recommended that a be turned on. Of course, both may be used together, or they may emit light of different colors.

Furthermore, as is clear from the above functions, although it is important to create the delay time td, the present invention does not specify the direction in which it is created.

For example 1. In the above embodiment, a type of monostable multivibrator is constructed as a discrete unit, but a monostable multivibrator 53 made of a commercially available IC may also be used as shown in the third figure.

Briefly, the comparator output S7 at the previous stage is inverted by the inverter 52 to form the INV (S7) signal, and the monostable multivibrator 53 is triggered by this signal.

As shown in FIGS. 4(A) and 4(C), the resulting output signal Sll of the monostable multivibrator 53 is
The relationship between and the comparator output signal S7 is, so to speak, a trailing relationship.

Therefore, in principle, if the OR gate 54 is used to OR the two, the required signal SIO shown in FIG. 4(D) should be obtained.
The output signal SI due to a slight time difference from the rising point of
It is possible that a hazard of
7' and this is given to the OR gate 54 alone, this signal S7' becomes the signal S7' with respect to the threshold level Et (2) of the OR gate 54 as shown in FIG. 4(B).
It crosses this a little later than the fall of 7, so the 4th
As shown by the circle 0 in Figure (C), it is possible to create an overlapping region where the signal Sll completely rises and then falls, and the above-mentioned hazard does not occur.

The required delay time Td for recovering the compressor function can be arbitrarily adjusted by varying the resistor 5B that normally determines the oscillation time of this type of monostable multivibrator IG.

The advantage of this second embodiment over the circuit 42 of the previously described embodiment is that when attempting to take a considerably long delay time td, the electrical time constant circuit (44, 45) This is not the case when the capacity increases. Although the function is different, the time constant circuit 55 is also required in this second embodiment, but the time constant may be extremely small and does not impede miniaturization.

In any case, as is clear from both of the above embodiments, the problem with the present invention is that the compressor function is not restored until a sufficient time td has elapsed even after the acceleration state has ended. This means that it is possible to reduce the number of times the compressor is repeatedly turned on and off under certain driving conditions, that is, under driving conditions that involve frequent acceleration and deceleration.

Note that in FIG. 1, the circuits 6, 10, and 18 can be considered as one unit, and can be considered as a converted voltage output circuit 40 whose output voltage changes in accordance with changes in engine speed. Therefore, a circuit other than the circuit configuration shown in the illustrated embodiment, such as a phase-locked loop configuration, may be used as desired in accordance with known techniques.

Further, the compressor intermittent circuit 41 may be electronically formed using a semiconductor element, and other common circuit technology and logic level processing may be used as desired.

Furthermore, the integration circuit 16 may be omitted by having time constant circuits (26, 27; 28, 28) provided at each input of the comparator 22 take over its function.

In addition, the output pulse width PW of the monostable multivibrator 11
is, for example, a resistor 1 that determines its time constant, as shown in the figure.
If 5 is configured to include a fixed resistor 15a and a variable resistor 15b, it can be easily adjusted by adjusting its resistance value.

In any case, as described in detail above, according to the present invention, an electronic device is used as a device to automatically disconnect the compressor from the engine, which can cause mechanical power loss, during acceleration when it is desirable to maximize engine efficiency. In addition to providing a device that is highly reliable, does not require a special sensor, and is easy to integrate into existing electrical systems, it also reduces the number of compressor intermittent cycles under driving conditions that involve frequent acceleration and deceleration. Since it can reduce wear of the compressor clutch and stress on the mechanical system, it is possible to provide a practical device with high commercial value.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a preferred embodiment of the device of the present invention;
FIG. 2 is an explanatory diagram of waveforms of each main part of the device shown in the first diagram;
The figure is a schematic configuration diagram of main parts of another embodiment, and FIG. 4 is a waveform diagram of each part of the circuit shown in the third diagram. In the figure, l is an ignition coil, 6 is a waveform shaping circuit, IO is a frequency modulation circuit, 11 is a monostable multivibrator, 1B is a frequency-to-voltage conversion circuit, 22 is a comparator, 23 is a change direction detection circuit, and 40 is the whole 41 is a compressor intermittent circuit, 42 is a compressor recovery time setting circuit, 44.45 is a time constant a circuit for setting 111 at the time of delay, 50 is a comparator, and 53 is a monostable multi-pipe brake.・In the evening, 54 is Noah Gate. Patent applicant Hanshin Electric Co., Ltd. / -ゝ＼ Agent Fuku 1) Nitsu
) No-

Claims (1)

[Scope of Claims] A rotation speed conversion voltage output generation circuit that extracts a rotation speed signal of an internal combustion engine mounted on a vehicle and generates an output whose voltage changes according to the process of increasing the rotation speed from a constant speed rotation state; A comparator that receives the voltage output from two people's power and inverts the output depending on the magnitude of the two people's power, and a comparator that has different time constants for the two people's power, and changes the converted voltage output during the rotation speed increasing process. a time constant circuit for inverting the comparator output;
a compressor intermittent device that interrupts the mechanical drive system between the internal combustion engine and the compressor by the inverted output of the comparator; a compressor return time setting circuit that provides a time delay between the re-inversion of the comparator output and the reconnection of the mechanical drive system between the internal combustion engine and the compressor by the compressor intermittent device; An automatic shut-off device for vehicle-mounted compressors.