JPS624257B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a continuously variable speed auxiliary drive device for an automobile engine.

An example of a conventional continuously variable auxiliary drive device of this kind for the purpose of lowering the rotation of the auxiliary device when the engine is running at high speeds is as shown in FIG. That is, this device has a shaft b fixed to an engine crankshaft a.
A V-grooved drive pulley c is installed on the top, and a cooling fan d and an auxiliary drive pulley e are installed on the auxiliary shaft f.
At the same time, a V-grooved driven pulley g is provided on this shaft f, and a V-belt h is installed between these pulleys.
It is spread over. The pulleys c and g have fixed flanges i and j fixed to the corresponding shafts b and f, respectively, and are movable in the axial direction with respect to the shafts b and f, and rotated together with the shafts b and f. It is composed of movable flanges k and l provided at. Further, a centrifugal actuator m is provided on the shaft b, and this diaphragm spring n constantly urges the movable flange k of the drive pulley c to the left in FIG. 1 so that it can move in the axial direction. It is configured. o is a centrifugal weight fixed to the outer periphery of this diaphragm n, which constitutes a centrifugal governor. A flange Q is fixed to the shaft f, and a diaphragm spring P supported by the flange Q constantly urges the movable flange l to the right in FIG.

In this conventional continuously variable speed auxiliary drive device,
A V-grooved pulley c and a diaphragm actuator m rotate together with a crankshaft a of the engine, and power is transmitted to a driven pulley g via a V-belt h. As a result, power is transmitted to the fan d and the accessory drive pulley e.

However, as the rotation of the crankshaft a increases, the centrifugal force generated in the centrifugal weight o fixed to the diaphragm spring n of the diaphragm actuator m that rotates together with the crankshaft a increases.
As a result, the diaphragm spring n moves in the axial direction (to the right in FIG. 1), causing the movable flange k integrally connected thereto to move away from the fixed flange i. Therefore, the V-belt h penetrates deep into the driving pulley c, and conversely, the movable pulley l of the driven pulley g approaches the fixed pulley j due to the action of the diaphragm spring P, so the V-belt h moves to the outer circumferential side of the driven pulley c. Move to. Therefore, the speed ratio of the moving pulley g becomes smaller, and the rotational speed of the fan d and the auxiliary equipment decreases. Furthermore, when the rotation of the crankshaft a is low, the elastic force of the diaphragm spring n overcomes the centrifugal force applied to the centrifugal weight o, and the movable flange k moves in the direction approaching the fixed flange i, causing the driven pulley g to move relative to the driving pulley c. The gear ratio becomes larger.

By the way, in such a conventional continuously variable speed auxiliary drive device, as described above, the axial movement of the movable flange k of the drive pulley c is performed by transmitting the centrifugal force applied to the centrifugal weight o in the axial direction. Because of this structure, the force that attempts to separate pulleys j and l changes depending on the magnitude of the load on the auxiliary equipment, resulting in a difference in the timing of shifting. Furthermore, since the auxiliary equipment rotational speed increases in proportion to the engine rotational speed, especially when the load on the auxiliary equipment is large, if the shift timing to reduce the gear ratio is delayed, the loss of horsepower due to the auxiliary equipment drive will increase. .

The present invention has been made to eliminate the above-mentioned drawbacks, and by driving the movable flange of the drive pulley by an electric motor and electrically controlling the driving conditions, the movable flange of the drive pulley is driven by an electric motor. The purpose of this invention is to solve the above problem by maintaining the auxiliary machine at a predetermined rotation speed.

Embodiments of the present invention will be described below with reference to FIGS. 2 to 4. In the figure, 1 is the engine body, 2 is the crankshaft, 3 is an auxiliary shaft that is rotatably provided with respect to the engine body 1 parallel to the crankshaft 2 at an appropriate interval, 4 is its bearing, and 5 is the A water pump chamber formed integrally with the engine body 1, 6
8 is an accessory drive pulley fixed to the shaft 3 via a key 7, and 8 is a fixed flange of a driven pulley formed integrally with this pulley 6. A spline 8a is formed on the inner circumference of this fixed flange 8. . Reference numeral 9 denotes a movable flange that faces the fixed flange 8 and is slidably fitted onto the shaft 3. This movable flange 9 is formed with a spline 9a that meshes with the spline 8a, and the fixed flange 8 and the movable flange 9 constitutes a driven pulley 10.

Also, 11 is an engine cooling fan, and key 12
It is fitted onto the shaft 3 via the cylindrical shaft 3 and fixed with a nut 13. Reference numeral 14 denotes a spring inserted between the end wall surface 9b of a hole provided in the boss portion of the movable flange 9 and the boss portion of the fan 11, which always acts to press the movable flange 9 toward the fixed flange 8. 15 is a V-belt.

In the present invention, a hollow cylindrical pulley auxiliary drive shaft 16 having a stepped portion is fitted to the end of the crankshaft 2 via a key 17, and is fitted to the small diameter portion of this shaft 16 via a needle bearing 18. A worm wheel 20 is formed integrally with a screw 19a on the outer periphery of the mating shaft cylindrical portion 19.
The shaft 16 through the radial ball bearing 21
Fits into the large diameter part of. 22 is a thrust bearing inserted between the stepped portion of the shaft 16 and the worm wheel 20, 23 is an oil seal provided between the engine body 1 and the shaft 16, and 24 and 25 are covers for the worm wheel 20 and a worm which will be described later. 26 is a packing inserted between the cases 24 and 25, and 27 is a bolt for fixing the cases 24 and 25 to the engine body 1.

Further, a flanged sleeve-shaped axially movable member 28 having a female thread 28a that engages with the thread 19a of the shaft cylindrical portion 19 is threaded with the screw 19a, and a fixing member 29 that engages with a groove 25a provided in the case 25. A radial ball bearing 30 is fitted to the outer periphery of this axially moving member 28, and a movable flange 31 for the drive pulley is attached to the bearing 30.
It is fitted in such a way that it is rotatable but not movable in the axial direction with respect to the axially moving member 28 via the key 32, and it is movable in the axial direction but cannot rotate with respect to the shaft 16 via the key 32. so that they fit together. 33 is a sealing member that seals between the movable flange 31 and the case 25.

Fixed flange 34 facing movable flange 31
is fitted and fixed to the end of the shaft 16 via a key 35. Reference numeral 36 designates a washer, which prevents the fixed flange 34 and the shaft 16 from coming off by a bolt 37 that passes through the shaft 16 and is screwed into the crankshaft 2. The fixed flange 34 and the movable flange 31 constitute a drive pulley 38.

Further, a worm 39 that meshes with the worm wheel 20 is provided in the case 25, and this worm 39 is provided in the case 25.
9 is driven by an electric motor M, and the operation of this electric motor M is controlled by inputting an electric signal that detects the state of the engine and auxiliary equipment to the control circuit of the electric motor M. The electric motor M is rotated in forward and reverse directions so that the number of rotations of the driven pulley 10 becomes a predetermined number of rotations.

Figure 3 shows an example of this control circuit. In the figure, S ₁ is an engine rotation speed sensor that detects the engine rotation speed from the primary side of the ignition coil (not shown), and S ₂ is the rotation speed of the alternator. S ₃ is an intake negative pressure sensor that detects engine intake negative pressure, S ₄ is an engine water temperature sensor that detects engine water temperature, and P ₁ emits an output corresponding to engine rotation speed of 4300 rpm. Output circuit, P ₂ is an output circuit that generates an output corresponding to an engine rotation speed of 1500 rpm, P ₃ is an output circuit that generates an output corresponding to an auxiliary alternator rotation speed of 3000 rpm, P ₄ is an engine intake negative pressure change rate of 150
Output circuit that emits output corresponding to mmHg/S, P ₅
is an output circuit that produces an output corresponding to an engine water temperature of 90°C, C ₁ is a comparator that outputs 1 when the engine speed is below 4300 rpm and 0 when the engine speed is above 4300 rpm, and C ₂ is an output when the engine speed is below 1500 rpm. _C3 is a comparator whose output is 1 when the alternator rotation speed is 3000 rpm or less, and ₀ when the alternator rotation speed is 3000 rpm or more. When the pressure change rate is 150mmHg/S or less, the output is 1 and 150mm
D is a differential circuit inserted between the suction negative pressure sensor S ₃ and comparator C ₄ , and C ₅ is a comparator that outputs 0 when the engine water temperature is 90°C or higher. , a comparator whose output is 1 above 90°C,
A ₁ and A ₂ are AND gates, OR is an OR gate, N is a not gate, R ₁ , R ₂ , R ₃ , R ₄ , and R ₅ are relays with normally open contacts, M is a motor, EV is a power supply, and E is a ground. It is. The above elements are connected as shown in FIG. 3 to constitute a control circuit.

Next, the operation of the transmission mechanism section of the device of the present invention constructed as described above will be explained.

The engine rotational force input from the engine crankshaft 2 is transmitted to the drive pulley 38 via the shaft 16, and transmitted to the driven pulley 10 via the drive pulley 38 and the V-belt 15.
Furthermore, a V-belt (not shown) is stretched between the pulley 10, the fan 11 arranged coaxially with the pulley 10, the auxiliary drive pulley 6, and the driven pulley (not shown) of each auxiliary machine, such as an alternator. , whereby each accessory is belt driven.

The electric motor M is controlled by the command of the control circuit shown in FIG.
When the worm wheel 20 rotates, the worm wheel 20 rotates via the worm 39.
The axially movable member 28 that is threadedly engaged with this axially movable member 28 moves in the axial direction through the screw 19a of the shaft cylinder portion 19 that is integral with the cylindrical portion 19, and the movable flange is moved through the ball bearing 30 fitted to this axially movable member 28. 31 is key 3
The movable flange 31 is moved in the axial direction while rotating with the shaft 16 by the key 32 via the ball bearing 30 fitted to this axially moving member 28. Moving. When the movable flange 31 moves axially, the V-belt 15 moves radially along the belt contact surface of each flange 31, 34.

That is, the movable flange 31 is the fixed flange 34.
When the movable flange 31 moves away from the fixed flange 34, the V-belt 15 moves inward.

Since the length of the V-belt 15 is constant, when the contact position of the V-belt 15 changes on the drive pulley 38 side, the V-belt 15 also moves in the radial direction of the pulley on the driven pulley 10 side.

That is, when the V-belt 15 engaged with the drive pulley 38 moves outward, the driven pulley 10
When the V-belt 15 engaged with the driven pulley 38 moves inward to increase the rotation speed of the driven pulley 10, and the V-belt 15 engaged with the drive pulley 38 moves inward, the V-belt 15 engaged with the driven pulley 10 increases the rotation speed of the driven pulley 10. The rotation of the driven pulley 10 is decelerated by moving outward.

Then, at the driven pulley 10, the V belt 1
When the fan 5 moves inside the pulley, the movable flange 9 moves against the spring 14 toward the fan 11 along the splines 8a and 9b. On the contrary, V
When the belt 15 moves to the outside of the pulley,
The movable flange 9 moves toward the fixed flange 8 along the splines 8a and 9a by the action of the spring 14. In either case, since the spring 14 always presses the movable flange 9 against the fixed flange 8 via the V-belt 15, an appropriate amount of frictional resistance is maintained between the V-belt 15 and each pulley. Therefore, the torque transmission ability of the V-belt 15 is not lost.

Next, the operation of the control circuit shown in FIG. 3 will be explained. Comparator when engine speed is below 1500rpm
The output of C ₂ is 0, and the engine speed is
Since the output of separator _C1 is 0 even when the engine speed is 4300rpm or more, the AND circuit is used even when the engine speed is 1500rpm or less or 4300rpm or more.
The output of _A1 is 0. Therefore, the output signal to the normally open relay _R1 also becomes 0. Therefore, since the contacts of relay _R1 remain open, no control is performed.

Next, since the outputs of the comparators C ₁ and C ₂ are both 1 when the engine speed is in the range of 1500 rpm to 4300 rpm, the output of the AND circuit A ₁ is also 1. Therefore, in this case the normally open relay _R1 is closed.

Further, when the rotation speed of the alternator is 3000 rpm or less, the output of the comparator _C3 is 1, and when the rotation speed is 3000 rpm or more, the output is 0.

Also, the engine intake negative pressure change rate is 150mmHg/
If it is greater than or equal to S, the output of comparator _C4 is 0, and if it is less than that, the output is 1.

Also, if the engine water temperature is below 90℃, the comparator
The output of _C5 is 0, and when the temperature is 90°C or higher, the output is 1.

Therefore, the output of AND circuit _A2 becomes 1 only when the alternator rotation speed is 3000 rpm or less and the suction negative pressure change rate is 150 mmHg/S or less.
and is 0 in all other cases.

Therefore, when the engine speed is within the range of 1500 to 4300 rpm and the engine water temperature is below 90 degrees Celsius, the alternator speed is 3000 rpm.
The output of the OR gate OR becomes 1 only when the suction negative pressure change rate is 150 mmHg/S or less, and the output is connected to the relays R ₂ and R ₃ with normally open contacts.
input and close each contact. On the other hand, when signal 1 is input to not gate N, its output becomes 0, so the contacts of relays R ₄ and R ₅ remain open.

Therefore, current flows through the electric motor M in the direction of the solid arrow in FIG. 3, and the continuously variable transmission is operated so that the gear ratio becomes larger.

However, if the rotational speed of the alternator exceeds 3000 rpm from the above state, the output of the comparator _C3 becomes 0, so the output of the AND circuit _A2 becomes 0, and the output of the OR gate OR also becomes 0.

Therefore, the contacts of relays R ₂ and R ₃ remain open, but the contacts of relays R ₄ and R ₅ have no gate N.
Since the inverted output 1 is input via
Contacts R ₄ and R ₅ are closed.

Therefore, as a result of current flowing through the electric motor M in the direction of the dotted arrow in FIG. 3, the electric motor M operates the continuously variable transmission so that the rotation direction is reversed and the gear ratio becomes smaller.

Figure 4 shows an example of the gear ratio characteristics of the continuously variable auxiliary drive system of the present invention, where the abscissa represents the engine rotational speed (rpm) and the ordinate represents the rotational speed of the driven pulley (rpm). It is a line diagram.

That is, in this case, the gear ratio is constant as shown in a-b until the engine speed is 1500 rpm, but when the engine speed is in the range of 1500 to 4300 rpm, the rotation speed of the driven pulley is approximately constant as shown in b-c. Moreover, when the engine speed is 4300 rpm or higher, the gear ratio becomes constant again as shown in c-d.

Furthermore, within the range b-c, if the suction negative pressure change rate exceeds 150 mmHg/S, that is, if sudden acceleration is performed, the output of comparator C ₄ becomes 0, and the output of AND circuit A ₂ and OR gate OR also becomes 0. 0, the electric motor M operates to reduce the gear ratio for a certain period of time, as shown by the downward protruding curve e in FIG. Therefore, according to the device of the present invention, it is possible to reduce the load on the auxiliary equipment during sudden acceleration.

Also, within the range b-c, the engine water temperature
When the temperature exceeds 90℃, the output of the comparator _C5 becomes 1, and as a result, the output of the OR gate OR becomes 1 in any case, so the operation of the electric motor M causes the fourth
As shown by the upwardly protruding curve f in the figure, the gear ratio is increased for a certain period of time. Therefore, according to the device of the present invention, overheating of the engine can be effectively prevented.

Since the present invention is configured as described above, the engine crankshaft and cooling are controlled based on various information such as not only the engine rotation speed but also the accessory drive pulley rotation speed, that is, the alternator rotation speed, engine water temperature, and suction negative pressure. fan, alternator
This allows for proper control of the gear ratio between engine auxiliary equipment such as the water pump, etc. (see Figure 4).
This has the excellent effect of reducing the horsepower loss as much as possible without impairing the performance of each of these auxiliary machines, thereby improving the fuel consumption rate and improving startability.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a conventional continuously variable speed accessory drive device, FIG. 2 is a cross-sectional view showing the continuously variable speed accessory drive device of the present invention, and FIG. 3 is a cross-sectional view of the continuously variable speed accessory drive device of the present invention. FIG. 4 is a diagram showing one embodiment of the circuit, and is a characteristic diagram showing an example of the relationship between the engine rotation speed and the driven pulley rotation speed of the continuously variable speed auxiliary drive device of the present invention. a...Crankshaft, b...Shaft, c...V
Grooved pulley, d... Cooling fan, e...
Auxiliary drive pulley, f...shaft, g...V-grooved driven pulley, h...V-belt, i, j...fixed flange, k, l...movable flange, m...diaphragm actuator, n...Diaphragm,
o...Centrifugal weight. 1...Engine body, 2...
...Crankshaft, 3... Axis for auxiliary equipment, 4...
Bearing, 5... Water pump chamber, 6... Auxiliary drive pulley, 7... Key, 8... Fixed flange, 8
a, 9a...spline, 9...fixed flange,
9b... end wall surface, 10... driven pulley, 11...
...Engine cooling fan, 12...Key, 13...
... Nut, 14 ... Spring, 15 ... V-belt, 16 ... Pulley drive shaft, 17 ... Key, 1
8...Needle bearing, 19...Shaft cylinder part, 1
9a...screw, 20...worm wheel, 21
...Radial ball bearing, 22...Thrust bearing, 23...Oil seal, 24,2
5... Case, 26... Packing, 27... Bolt, 28... Axial moving member, 28a... Female thread, 29... Fixed member, 30... Radial ball bearing, 31... Movable flange, 32... ...Key, 33 ... Seal member, 34 ... Fixed flange, 35 ... Key, 36 ... Washer, 37 ... Bolt, 38 ... Drive pulley, 39 ... Worm.
S ₁ ... Engine speed sensor, S ₂ ... Alternator speed sensor, S ₃ ... Intake intake negative pressure sensor, S ₄ ... Engine water temperature sensor, P ₁ , P ₂ ,
P ₃ , P ₄ , P ₅ ... Output circuit, C ₁ , C ₂ , C ₃ , C ₄ ...
Comparator, A ₁ , A ₂ ...AND gate, D ... Differential circuit, N ... Not gate, OR ... OR gate, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ ... Normally open contact relay,
M...Electric motor, EV...Power supply, E...Earth.

Claims (1)

[Claims] 1. A V-belt is stretched between a pair of V-grooved pulleys, and the flange of one of the pulleys is movable in the axial direction relative to the other fixed flange, and the flange of one of the pulleys is movable in the axial direction with respect to the movable flange of the drive pulley. Or, at the same time, the movable flange of the driven pulley for driving various engine accessories is moved away from or approached the fixed flange, thereby making it possible to change the gear ratio steplessly. In the machine drive device, an axially moving member is rotatably connected to the movable flange of one of the pulleys, and a transmission mechanism is provided to drive this axially moving member by an electric motor, and the state of the engine and auxiliary equipment is detected. An electric signal is input to a control circuit of the electric motor, and the electric motor is rotated in forward and reverse directions so that the rotation speed of a driven pulley for driving auxiliary equipment becomes a predetermined rotation speed within a predetermined range of engine rotation speeds. Continuously variable speed auxiliary drive system for automobile engines. 2. Claim 1, wherein signals from an engine rotation speed sensor that outputs a signal corresponding to the engine rotation speed and an auxiliary rotation speed sensor that outputs a signal corresponding to the rotation speed of an auxiliary device are input to the control circuit. The continuously variable speed auxiliary drive device for the automobile engine described above. 3 The water temperature signal obtained from the engine water temperature sensor, which outputs a signal corresponding to the engine cooling water temperature, is input to the control circuit, and when the engine water temperature exceeds the set temperature, the accessory drive pulley is rotated at an increased speed. A continuously variable speed auxiliary drive device for an automobile engine according to claim 1 or 2. 4 The intake negative pressure signal obtained from the intake negative pressure sensor that outputs a signal corresponding to the intake negative pressure of the engine is input to the control circuit, and when the intake negative pressure change rate exceeds the set value, the auxiliary equipment A continuously variable speed auxiliary drive device for an automobile engine according to claims 1 to 3, which is configured to lower the rotational speed of the engine.