JPH09210818A - Apparatus for calculating torque of auxiliary machinery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To calculate a torque of an auxiliary machinery with high measuring accuracy. SOLUTION: A torque of an auxiliary machinery can be calculated if only a ratio W1/W2 of rotating speeds W1, W2 of first and second idler pulleys 8, 10 is detected. In other words, the rotating speeds W1, W2 of the first and second idler pulleys 8, 10 are detected at all times by first and second rotating speed detection means 101, 102, and detection signals are input to an electric control device 200. An operating means of the electric control device 200 calculates the torque of the auxiliary machinery.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an auxiliary machine torque calculating device, and more particularly, to a total amount of load torque of a refrigerant compressor of an air conditioner which is an auxiliary machine of an automobile engine, a hydraulic pump of a power steering, an alternator and the like. It is suitable for use in an auxiliary machine torque calculation device for calculation.

[0002]

2. Description of the Related Art In an internal combustion engine mounted on a vehicle such as an automobile, its accessories, for example, a refrigerant compressor of an air conditioner,
A power steering hydraulic pump, an alternator, a radiator cooling fan, etc. are simultaneously driven by a crankshaft pulley attached to a crankshaft of an engine via a series of belts.

If the load torque (auxiliary machine torque) of these auxiliary machines can be accurately measured, the idle speed can be controlled with higher accuracy, so that the idle speed can be further reduced and the fuel consumption can be reduced. It is possible to reduce the shift, and the automatic transmission can be controlled more finely to make the shift change smoother.

On the other hand, as a general method for measuring accessory torque, Japanese Utility Model Laid-Open No. 63-167230 discloses that a rotary drive shaft undergoes elastic torsional deformation in accordance with the total amount of accessory torque. By using this, a strain gauge is attached to a part of this rotary drive shaft, the electrical resistance value of the strain gauge is measured, and the minute amount of twist of the rotary drive shaft is detected from the change, so that the auxiliary machinery A method for measuring the total amount of torque is shown.

[0005]

However, in the measuring method according to the above-mentioned conventional technique, the output characteristics greatly change depending on how the strain gauges are attached, so that the measured values with respect to a certain torque amount are likely to vary, and the measurement accuracy is high. Is low. Further, since the strain gauge is adhered to a rotating body such as a rotary drive shaft, it is necessary to use a sliding mechanism such as a slip ring to take out an output signal (electrical signal) from the strain gauge. . According to this, the output characteristics are greatly changed due to dimensional error of the slip ring or the like and dimensional change due to wear of the sliding portion.

The present invention has been made in view of the above points, and an object of the present invention is to provide an auxiliary machine torque calculation device having high measurement accuracy.

[0007]

DISCLOSURE OF THE INVENTION The inventors of the present invention have studied the factors other than the elastic torsional deformation of the rotary drive shaft, which have a correlation with the auxiliary machine torque, and as a result, the rotation of the drive shaft pulley (6). Direction (V1) of the moving speed (V1) of the belt (71) on the front side in the direction of rotation and the moving speed (V2) of the belt (72) on the rear side in the rotating direction of the drive shaft pulley (6).
It was found that V2) has a correlation with the auxiliary machine torque.

Therefore, in the invention described in claims 1 to 5, the moving speed (V1) of the belt (71) on the front side in the rotational direction of the drive shaft pulley (6) is detected by the first moving speed detecting means (8, 101). Is detected and the second moving speed detecting means (10,
The moving speed (V2) of the belt (72) on the rear side in the rotation direction of the drive shaft pulley (6) is detected by 102). Then, the first and second moving speed detecting means (8, 101), (1
Belt (71, 72) detected by (0, 102)
It is characterized in that it is provided with a computing means (200) for calculating the auxiliary machine torque based on the moving speeds (V1, V2) of the above.

According to this, the moving speed (V1, V2) of the belt (71, 72) is detected by the first and second moving speed detecting means (8, 101), (10, 102) without contact. Thus, the accessory torque can be calculated. Therefore, the output signal does not change depending on the mounting method unlike the conventional technique using the strain gauge, and the output signal is not taken out from the rotating body such as the rotating shaft. It is possible to provide an auxiliary machine torque calculation device with high measurement accuracy without the need to use a moving mechanism.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) As shown in FIG. 1, in an internal combustion engine 1 mounted on an automobile or the like, an accessory pulley for driving various accessories, for example, a first compressor for a refrigerant compressor of an air conditioner.
Many accessory machines such as the accessory pulley 2, the second auxiliary machine pulley 3 for the power steering hydraulic pump, the third auxiliary machine pulley 4 for the generator, and the fourth auxiliary machine pulley 5 for the radiator cooling fan. Are simultaneously driven by a crankshaft pulley (drive shaft pulley) 6 of the internal combustion engine 1 via a series of belts 7. The crankshaft pulley 6 is rotating in the direction indicated by arrow R in FIG.

A first idler pulley 8 not related to the drive of the auxiliary machine is provided on the belt 71 on the front side in the rotational direction of the crankshaft pulley 6 (the right side of the crankshaft pulley 6 in FIG. 1). Furthermore, an automatic tensioner 9 that automatically adjusts the tension of the belt 7 to a constant value is provided with a second idler pulley 10 on the rear side in the rotational direction of the drive shaft pulley (in FIG. 1, crankshaft pulley). It is provided on the belt 72 (on the left side of 6).

Reference numerals 101 and 102 denote first and second rotational speed detecting means for electrically detecting the rotational speeds W1 and W2 of the first and second idler pulleys 8 and 10, respectively.
Is an electric control device provided with a calculating means for calculating the auxiliary machine torque based on the detection signals from the first and second rotation speed detecting means 101, 102. Reference numeral 300 denotes an electronically controlled fuel injection device, and the fuel injection amount of the electronically controlled fuel injection device 300 is controlled by the electric control device 200 according to the value of the calculated auxiliary machine torque.

The specific structure of the second idler pulley 10 will be described below with reference to FIGS. 2 (a) and 2 (b). Since the first idler pulley 8 has almost the same structure as the second idler pulley 10, a detailed description will be omitted. As shown in FIGS. 2A and 2B, a large number of teeth 12 made of a magnetic material are provided at equal intervals on the annular inner surface 11 of the second idler pulley 10. The base portion 14 of the arm 13 of the auto tensioner 9 has the internal combustion engine 1
It is supported by a shaft (not shown) provided on the side surface of the main body so as to be rotatable within a narrow angle range (for example, about 2 °). Further, the arm 13 is biased by a biasing means (not shown) in a direction in which the belt 7 is tensioned. Further, a bearing 16 is provided on the shaft 15 integrally attached to the free end of the arm 13, so that the second idler pulley 10 is rotatably supported by the shaft 15.

An electromagnetic pickup 18 serving as a second rotation speed detecting means 102 is attached to the protrusion 17 which projects substantially vertically from the arm 13. The tip of the electromagnetic pickup 18 is projected at a position where it can face a large number of teeth 12 made of a magnetic material with a predetermined gap. This electromagnetic pickup 18 is a coil wound around a permanent magnet, and both ends of the coil are directly connected to external fixed terminals by flexible lead wires 19 and 20. Here, since the movement (rotation) range of the arm 13 is limited within a narrow angle, when the output signal from the coil of the electromagnetic pickup 18 fixed to the arm 13 is taken out, the slip ring according to the conventional technique is used. It is not necessary to use such a sliding mechanism.

The first idler pulley 8 is rotatably supported by a shaft (not shown) integrally fixed to the side surface of the main body of the internal combustion engine 1, and corresponds to the protrusion 17 of the second idler pulley 10. Is formed in the main body of the internal combustion engine 1, so that the electromagnetic pickup of the first idler pulley 8 does not need to use the sliding mechanism. Hereinafter, a method of detecting the rotation speed W2 of the second idler pulley 10 and a method of calculating the accessory torque will be described with reference to the drawings. FIG.
6 is a flowchart showing a procedure for calculating an accessory torque by the electric control device 200. Since the method of detecting the rotation speed W1 of the first idler pulley 8 is the same as the rotation speed W2, the description thereof will be omitted.

First, when the second idler pulley 10 rotates as the belt 7 rotates, many teeth 12 pass through the detection end of the electromagnetic pickup 18 in FIG. 2B.
Before and after this passage, a pulse current having peaks at substantially equal intervals as a voltage waveform is generated in the coil of the electromagnetic pickup 18, and the pulse current causes the lead wires 19, 20 and the like to be output signals corresponding to the rotation speed W2. It is taken out directly to the external fixed terminal via the and is input to the electric control device 200 (see FIG. 1) equipped with a calculation means.

In the electric control device 200, the rotational speed W of the second idler pulley 10 is calculated by counting the peak number of the pulse current per unit time.
Measure 2. In the present embodiment, the second idler pulley 10, the electromagnetic pickup 18, and the large number of teeth 12 are provided.
Thus, the second rotation speed detecting means 102 (see FIG. 1) is configured. In addition, the second idler pulley 10 and the second idler pulley 10
The rotation speed detecting means 102 constitutes second moving speed detecting means in the claims.

According to the present inventors, the rotational speed ratio W1 / W2 of the rotational speeds W1 and W2 of the first and second idler pulleys 8 and 10 and the accessory torque Trq are expressed by the following equation (7). It has been found that it is represented by. Therefore, the second rotation speed detecting means 102 always detects the rotation speed W2 of the second idler pulley 10 (S2 in FIG. 3), and similarly, the first rotation speed detecting means 101 causes the first idler pulley 8 to rotate. Rotation speed W1
Is constantly detected (S1 in FIG. 3). Then, this detection signal is input to the electric control device 200, and the rotational speed W1 is calculated by a calculation means (not shown) provided in the electric control device 200.
, W2 rotation speed ratio W1 / W2 is calculated (S in FIG.
3) Further, the rotational speed ratio W1 / W2 is substituted into the following formula 7 to calculate the accessory torque Trq (S4 in FIG. 3).

The electronically controlled fuel injection device 3 of the internal combustion engine 1 according to the variation of the value of the auxiliary machine torque Trq calculated in this way.
The fuel injection amount of 00 is controlled. Specifically, when the accessory torque Trq increases, the fuel injection amount is increased to
The engine stall is prevented by increasing the idle speed. When the accessory torque Trq decreases, the fuel injection amount is reduced and the idle speed is reduced to improve fuel efficiency.

According to such a method, the first,
Since the rotational speeds W1 and W2 of the second idler pulleys 8 and 10 can be detected, it is not necessary to use a strain gauge as in the prior art, and the accessory torque can be calculated with extremely high accuracy. The process of deriving the relational expression (Equation 7 below) between the accessory torque Trq and the rotation speed ratio W1 / W2 will be described below.

First, when the auxiliary machine torque is generated, the belt 71 on the front side in the rotational direction of the crankshaft pulley 6 is stretched and the belt 72 on the rear side in the rotational direction of the crankshaft pulley 6 is loosened. Here, when the radius of the crankshaft pulley 6 is R, the tension of the tension side belt 71 is T1, and the tension of the slack side belt 7 is T2, the accessory torque Trq acting on the crankshaft 21 is expressed by the following formula 1 It is represented by.

[0022]

## EQU1 ## Trq = R × (T1−T2) Further, assuming that the elastic constant of the belt 7 is K and the belt strain amount per unit length is ε1 (tension side) and ε2 (slack side), the tensions T1 and T2 are given. Is expressed by Equation 2 below.

[0023]

[Equation 2] T1 = K × ε1, T2 = K × ε2 Then, the belt 7 is not tensioned (natural length).
Where the linear density of the belt 7 is ρ, the linear densities ρ1 and ρ2 of the belt 7 when the tensions are T1 and T2 are expressed by the following mathematical formula 3.

[0024]

[Formula 3] ρ1 = ρ / (1 + ε1), ρ2 = ρ / (1 + ε2) Then, the moving speeds of the belts 71 and 72 on the tension side and the slack side are V1 and V2, respectively, and the law of conservation of mass and ε1 << 1 Applying the approximation, the following Equation 4 is derived.

[0025]

## EQU00004 ## V1 / V2-1 = (. Epsilon.1-.epsilon.2) Then, using the above formulas 1, 2 and 4, the accessory torque T
rq is represented by the following Equation 5.

[0026]

## EQU00005 ## Trq = R.times.K.times. (V1 / V2-1) Here, since the first and second idler pulleys 8 and 10 are not related to the drive of the auxiliary machine, the belts 71 and 72 and the first and second idler pulleys 10 and The slip between the second idler pulleys 8 and 10 can be ignored, and when R1 and R2 are the radii of the first and second idler pulleys 8 and 10, the belt 7 on the tension side and the slack side
The moving velocities V1 and V2 of 1 and 72 are expressed by the following Equation 6.

[0027]

## EQU6 ## V1 = R1.times.W1 V2 = R2.times.W2 Then, from the above formulas 5 and 6, the accessory torque Trq is obtained.
Is expressed by Equation 7 below.

[0028]

(7) Trq = R × K × ((R1 / R2) × (W1 / W
2) -1) (Second embodiment) In the first embodiment, the first and second
Although the electromagnetic pickup 18 is used as the rotation speed detecting means 101, 102, in the second embodiment, the first,
The second rotation speed detecting means 101, 102 using light will be described. In FIGS. 4A and 4B, 22 is a light emitting element such as a light emitting diode, and 23 is a light receiving element such as a photodiode. The light emitting element 22 and the light receiving element 23 are provided in the second idler pulley 10. The edges are arranged so as to face each other. The light emitting element 22 is supported and fixed to a supporting portion 24 which is integrated with the arm 13, and the light receiving element 23 is fixed to the arm 13.

A donut-shaped rotary slit 25 is fixed to the edge of the second idler pulley 10.
As shown in FIG. 4 (b), the rotary slit 25 has a donut-shaped plate 26 and an opening 27 elongated in the radial direction.
Are formed at equal intervals in the circumferential direction. Further, a plate-shaped fixed slit 29 as a mask is fixed to the surface of the light receiving element 23 on the light emitting element 22 side, and the fixed slit 29 is formed with some openings 30.

When the second idler pulley 10 rotates with the rotation of the belt 7, the rotary slit 25 also rotates. Here, the opening 27 of the rotary slit 25,
The light emitted from the light emitting element 22 reaches the light receiving element 23 and the pulse current is output from the light receiving element 23 only when the opening 30 of the fixed slit 29 overlaps with the optical axis direction of the light emitting element 22.

Then, the number of peaks of the pulse current per unit time is counted by the electric control unit 200 (see FIG. 1) to measure the rotation speed W2 of the second idler pulley 10. That is, the light emitting element 22, the light receiving element 23, the rotating slit 25, and the fixed slit 29 allow the second
It constitutes the rotational speed detecting means 102 (see FIG. 1). According to this, the same effect as that of the first embodiment can be obtained.

(Other Embodiments) In the above embodiment, the rotation speed W1 of the first and second idler pulleys 8 and 10 is
, W2 are detected and the auxiliary machine torque is calculated from this rotational speed ratio W1 / W2, but the present invention is not limited to this, and the moving speed of the belt 7 on the tension side or the slack side can be directly calculated. V1 and V2 are detected without contact, and the moving speed ratio V1 /
The auxiliary machine torque may be calculated by substituting V2 into the equation (5).

In the above embodiment, the rotation speed ratio W1
The auxiliary machine torque is calculated by substituting / W2 into the above equation 7, but the present invention is not limited to this, and a calibration curve of the auxiliary machine torque and the rotational speed ratio W1 / W2 is obtained in advance. The auxiliary machine torque corresponding to the detected rotational speed ratio W1 / W2 may be read from this calibration curve. Further, in the above-described embodiment, the accessory torque of the accessory drive device of the vehicle is calculated, but the present invention is not limited to this, and calculates accessory torque for various applications. Good.

Further, the accessory torque calculated by the accessory torque calculating device of the above embodiment may be used for controlling the electronically controlled automatic transmission.

[Brief description of drawings]

FIG. 1 is a front view showing the overall configuration of a first embodiment of the present invention.

FIG. 2A is a cross-sectional view showing a main part of the first embodiment, and FIG. 2B is a bottom view of a second idler pulley in FIG.

FIG. 3 is a flowchart showing a procedure for calculating an accessory torque in the first embodiment.

FIG. 4A is a sectional view showing an essential part of the second embodiment, and FIG. 4B is a conceptual perspective view of an essential part of a rotation speed detecting means in FIG.

[Explanation of symbols]

2, 3, 4, 5 ... Auxiliary equipment pulley, 6 ... Crankshaft pulley (driving shaft pulley), 7, 71, 72 ... Belt, 8 ... First
Idler pulley, 10 ... Second idler pulley, 101,
102 ... First and second rotational speed detecting means, 200 ... Electric control device (calculating means).

Claims (5)

[Claims] 1. A drive shaft pulley (6) mounted on a rotary drive source for driving an accessory, and accessory pulleys (2, 3, 4, 5) mounted on at least one said accessory. , The drive shaft pulley (6) and the accessory pulley (2,
An auxiliary machine torque calculation device for use in an auxiliary machine drive device, comprising: a belt (7) wound commonly around (3, 4, 5), the belt being on the front side in the rotation direction of the drive shaft pulley (6). (7
The first moving speed detecting means (8, 101) for detecting the moving speed (V1) of 1), and the belt (7) on the rear side in the rotation direction of the drive shaft pulley (6).
2) second moving speed detecting means (10, 102) for detecting the moving speed (V2), and the first and second moving speed detecting means (8, 101), (1)
Belt (71, 72) detected by (0, 102)
And an arithmetic means (200) for calculating the auxiliary machine torque based on the moving speeds (V1, V2) of the auxiliary machine torque calculating apparatus. 2. The first moving speed detecting means (8, 10)
1) hangs the belt (71) on the front side in the rotation direction of the drive shaft pulley (6), and has a first idler pulley (8) not related to the drive of the accessory, and the first idler pulley (8). ) And a first rotation speed detection means (101) for detecting the rotation speed of the drive shaft pulley (6). A belt (72) is suspended, and a second idler pulley (10) not related to the drive of the auxiliary machine and a second rotation speed detection means (102) for detecting the rotation speed of the second idler pulley (10) are provided. The auxiliary device torque calculation device according to claim 1, wherein the auxiliary device torque calculation device is provided. 3. The first and second rotation speed detecting means (10)
The auxiliary machine torque calculation device according to claim 1 or 2, wherein each of (1) and (102) includes an electromagnetic pickup (18). 4. The first and second rotation speed detecting means (10)
Reference numerals 1) and (102) denote a light emitting element (22) and a light receiving element (2).
3) and a slit (25) that rotates, The auxiliary machine torque calculation device according to any one of claims 1 to 3. 5. The auxiliary machine torque calculating method according to claim 1, wherein the calculating means (200) calculates an auxiliary machine torque using the following relational expression. Trq = R × K × (V1 / V2-1)