JPH06144069A - Hydraulic driving device of auxiliary equipment for vehicle - Google Patents

Abstract

PURPOSE:To drive a series of auxiliary equipment such as a hydraulic pump, a cooling fan or an alternator or the like for a compressor and a power steering unit regardless of a variation in engine speed. CONSTITUTION:A minimum volume starting type hydraulic pump 2 is operatively connected to an engine 1, while a discharge oil quantity control mechanism controlling a discharge oil quantity almost constant irrespective of engine speed is installed in this hydraulic pump 2, and a hydraulic motor 8 is connected to this hydraulic pump 2 as well. In succession, auxiliary equipment such as a compressor 18 of a car air conditioner, a hydraulic pump 9 of a power steering unit, a cooling fan 23 or an alternator 15 or the like are operatively connected to an output shaft 10 of this hydraulic motor 8 via six pulleys 11, 13, 17, 19, 21a, 24 and two belts 14, 22, and a pulley ratio is set to such a value as turning to an optimum rotation of each auxiliary equipment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic drive system for a vehicle auxiliary equipment such as a compressor for a vehicle air conditioner, a hydraulic pump for a power steering system, an alternator, or a cooling fan.

[0002]

2. Description of the Related Art Generally, an auxiliary equipment such as a compressor for a cooling device, a hydraulic pump for a power steering device, or an alternator is provided in an engine room of an automobile. In these auxiliary devices, a V-belt is wound between a driving pulley attached to the output shaft of the engine and a driven pulley attached to the rotating shaft of each device, so that each device is rotationally driven at a constant pulley ratio. ing.

The pulley ratio of each auxiliary device is set so as to ensure the lowest level of operating conditions, and conversely, power loss occurs during high-speed operation. To solve this problem,
The one shown in Japanese Patent Publication No. 50-34821 is proposed. This hydraulic drive system drives a plurality of tandem-coupled constant-capacity hydraulic pumps by an engine, and each hydraulic pump is connected to one constant-capacity hydraulic motor via a plurality of electromagnetic on-off valves. The hydraulic motor rotates the compressor of the cooling device. Further, the number of rotations of the engine is detected by a detector, a plurality of electromagnetic on-off valves are selectively opened according to the number of rotations, and the number of rotations of the hydraulic motor is controlled to be constant.

[0004]

However, in the conventional hydraulic drive system described above, only the compressor can rotate at a constant speed, and the drive system of the compressor is complicated and large, so that the cost is reduced. There was a problem that could not be achieved.

Therefore, as a drive device for rotating a plurality of auxiliary devices at a constant speed, there is a conventional device disclosed in JP-A-55-109855.
The one shown in the publication is proposed. This drive is
A power transmission device is mounted on the output shaft of the engine, and a V-belt is wound between a drive pulley formed on the outer periphery of the power transmission device and a driven pulley supported by the rotary shafts of the compressor and the cooling fan.

However, in this drive device, the power transmission device becomes large in size due to its complicated structure, and a further power transmission device is required to drive devices other than the compressor and the cooling fan. was there.

A first object of the present invention is to solve the above-mentioned problems of the prior art and to optimize a plurality of auxiliary equipment such as a compressor, a hydraulic pump for a power steering device or an alternator, regardless of fluctuations in the engine speed. An object of the present invention is to provide a hydraulic drive device for a vehicle auxiliary device that can be driven by.

A second object of the present invention is to be able to drive a plurality of auxiliary equipment such as a compressor or an alternator at an optimum rotation speed irrespective of fluctuations in the rotation speed of the engine, and to provide a hydraulic pump for a power steering system. An object of the present invention is to provide a hydraulic drive system for an auxiliary device for a vehicle, which can be omitted.

Further, a third object of the present invention is the above-mentioned second object.
In addition to the above-mentioned object, it is an object of the present invention to provide a hydraulic drive system for an auxiliary device for a vehicle, which can further simplify the structure.

[0010]

In order to achieve the first object of the present invention, a minimum capacity start-up type hydraulic pump is operatively connected to the engine, and the discharge oil amount is substantially constant in the hydraulic pump. Is provided with a discharge oil amount control mechanism, a hydraulic motor is connected to the hydraulic pump, and a compressor of a vehicle air conditioner, a hydraulic pump of a power steering device, and a cooling are connected to an output shaft of the hydraulic motor via a pulley and a belt. Among the auxiliary devices such as a fan or an alternator, a plurality of auxiliary devices are operatively connected, and the pulley ratio is set to a value that provides optimum rotation of each auxiliary device.

In order to achieve the second object, the invention according to claim 2 is a discharge oil amount control for operatively connecting a minimum capacity start-up hydraulic pump to the engine and controlling the discharge oil amount to the hydraulic pump to be constant. A mechanism is provided, a hydraulic motor is connected to the hydraulic pump, and a plurality of auxiliary devices among auxiliary devices such as a compressor, a cooling fan or an alternator of a vehicle air conditioner are connected to an output shaft of the hydraulic motor via a pulley and a belt. Operatively connected, setting the pulley ratio to a value that provides optimum rotation of each auxiliary device, further disposing a flow divider in the discharge pipe line from the hydraulic pump to the hydraulic motor, and providing a power steering device at the flow dividing port of the flow divider. The means of connecting the working cylinder of is adopted.

In order to achieve the above-mentioned third object, the third aspect of the present invention adopts the means of assembling the flow divider to the hydraulic motor in the second aspect.

[0013]

According to the first aspect of the invention, when the engine is started, the hydraulic pump is started in the minimum capacity state, and the pressure oil discharged from the hydraulic pump is supplied to the hydraulic motor. For this reason, the hydraulic motor is rotated at a low speed, auxiliary devices such as the compressor of the vehicle air conditioner, the hydraulic pump of the power steering device, the cooling fan, and the alternator are rotated at a low speed, and the shock at the time of starting is mitigated.

When the engine speed increases, the discharge oil amount of the hydraulic pump increases, but when the engine speed exceeds a predetermined value, the discharge oil amount control mechanism controls the discharge oil amount of the hydraulic pump to be substantially constant. The hydraulic motor is rotated at a substantially constant speed. Therefore, each auxiliary device is operated at an optimum rotation speed with a predetermined pulley ratio.

According to the second aspect of the present invention, the pressure oil discharged from the hydraulic pump is diverted by the flow divider to supply an appropriate amount of oil to the working cylinder of the power steering device, so that the power steering device is operated efficiently. It

Further, the invention according to claim 3 is the same as claim 2
In addition to the effect of the invention described above, the mounting structure of the flow divider can be simplified and the number of parts such as piping and mounting members can be reduced.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First embodiment of the invention described in claim 1 below.
An embodiment will be described with reference to FIGS.

As shown in FIG. 1, a minimum capacity start-up hydraulic pump 2 is arranged in the vicinity of an engine 1 mounted on an automobile, and the power of the engine 1 is driven by a drive pulley 3 and a driven pulley 4.
And is transmitted as a rotary motion to the hydraulic pump 2 via the V belt 5. As will be described later in detail, the hydraulic pump 2 is started with a minimum capacity when the engine 1 is started, and thereafter, when the number of revolutions of the engine 1 becomes a predetermined number of revolutions or more, a fixed amount of oil is discharged regardless of the rotational fluctuation. I am trying.

A hydraulic motor 8 is connected to the discharge line 6 and the suction line 7 of the hydraulic pump 2. A hydraulic pump 9 for a power steering device is arranged on the side of the hydraulic motor 8, and is attached to a first drive pulley 11 attached to an output shaft 10 of the hydraulic motor 8 and a rotary shaft 12 of the hydraulic pump 9. A first V belt 14 is looped between the first driven pulley 13 and the first driven pulley 13. Further, an alternator 15 is provided on the side of the hydraulic motor 8 and a rotary shaft 16 thereof has a second
A driven pulley 17 is attached, and the first V belt 14 is hung on the pulley 17.

A compressor 18 for a vehicle interior air conditioner is arranged beside the hydraulic pump 9 for the power steering device. The first drive pulley 11 includes a second drive pulley 1
9 is fixed, and the second V belt 22 is hung between the third driven pulley 21a of the electromagnetic clutch 21 attached to the rotary shaft 20 of the compressor 18, and the rotary motion of the hydraulic motor 8 is applied to the compressor 18. Can be communicated. The second V-belt 22 is mounted on a fourth driven pulley 24 for driving a cooling fan 23 for cooling the engine 1 and a radiator (not shown).

Next, the structure of the minimum capacity start-up hydraulic pump 2 will be described with reference to FIGS. As shown in FIG. 2, the front housing 26 is joined and fixed to the front (left) end surface of the center housing 25, and the rear end cover 27 is joined and fixed to the rear (right) end surface of the center housing 25. A working space 28 is formed. A rotary shaft 29 is provided between the opposing end walls of the front housing 26 and the rear end cover 27, and a bearing 30, 3
1, the driven pulley 4 is fixed to the outer end portion thereof.

A cylinder block 32 is connected to the rotary shaft 29 by a spline so as to be able to rotate synchronously, and a plurality of cylinder bores 33 are formed in the cylinder block 32 in parallel with the rotary shaft 29. An operating piston 36 moored to a swash plate 35 via a shoe 34 is housed in each of the cylinder bores 33 so as to be capable of reciprocating. Further, the cylinder bore 33 in the cylinder block 32 that rotates integrally with the rotary shaft 29 is alternately communicated with the suction port 38 and the discharge port 39 which are formed in the valve plate 37 and have an arc shape. As a result, the hydraulic oil is sucked into the cylinder bore 33 from the suction port 38, and the hydraulic oil in the cylinder bore 33 is discharged from the discharge port 39. A suction passage 40 and a discharge passage 41, which communicate with the suction port 38 and the discharge port 39, are formed in the rear end cover 27, and the suction passage 7 is connected to the suction passage 40. Reference numeral 26a is a stopper that regulates the maximum tilt angle of the swash plate 35.

Due to the return spring 42, the swash plate 35 always has a minimum tilt angle (about 0.1 to 4 °) equal to zero capacity.
It is biased in the direction of displacement to the minimum capacity position. The rear end cover 27 has a control cylinder 4
3 is supported in a cantilever manner, and a control piston 44 is accommodated in the cylinder 43 so as to be reciprocable in the same direction as the rotary shaft 29. The tip surface of the control piston 44 is the swash plate 3.
5, the sphere moored to a part of the slab 5 is pushed so as to increase the inclination angle of the swash plate 35 against the urging force of the return spring 42, thereby changing the stroke of the working piston 36, and discharging The capacity can be adjusted. Therefore, since the control chamber 43a in the control cylinder 43 is at atmospheric pressure when the hydraulic circuit is stopped,
The swash plate 35 is urged and held at the minimum discharge capacity position by the urging force of the return spring 42 as shown in FIG.

Next, the discharge oil amount control mechanism K for controlling the discharge oil amount of the hydraulic pump 2 to be substantially constant irrespective of the rotation fluctuation of the engine 1 will be described with reference to FIGS. or,
As shown in FIG. 2, an auxiliary housing 45 is joined and fixed to the front surface of the rear end cover 27, and a discharge passage 46 that connects the discharge passage 41 and the discharge conduit 6 to the housing 45.
And a fixed throttle 47 is interposed in the discharge passage 46. The discharge passage 46 on the upstream side of the throttle 47 and the control chamber 43a of the control cylinder 43 are connected by a control passage 48. The control passage 48 includes a discharge passage 46.
A capacity control valve 49 for controlling the amount of control oil supplied to the control chamber 43a to operate the control piston 44 to change the tilt angle of the swash plate 35 is interposed.

As shown in FIG. 4, the auxiliary housing 45 is
An accommodating chamber 45a is formed in the accommodating chamber 45a, and a spool 51 as a valve element is accommodated in the accommodating chamber 45a so as to be linearly movable back and forth. The spool 51 has a first and second large diameter portion 51.
a and 51b are formed, and an annular groove 51c is formed between the large diameter portions. A first pressure sensing chamber R ₁ is formed on the left side of the spool accommodating chamber 45a, and the pressure sensing chamber R ₁ is connected to the discharge passage 46 on the upstream side of the throttle 47 via a first pilot oil passage P ₁ . Connected. Further, a second pressure sensing chamber R ₂ is formed on the right side of the spool accommodating chamber 45a,
A spring 52 for urging the spool 51 is interposed inside thereof. The spring 52 urges the spool 51 to open the control passage 48 and close the drain passage 53 communicating with the oil tank T. The second pressure sensing chamber R ₂ communicates with the discharge passage 46 on the downstream side of the throttle 47 via the second pilot oil passage P ₂ .

In this embodiment, the discharge pressure of the hydraulic pump 2 is changed by acting the differential pressure across the throttle 47 on the first and second pressure sensitive chambers R ₁ and R ₂ of the displacement control valve 49. Is controlled to be substantially constant as described later.

Next, the operation of the hydraulic drive system for the vehicle auxiliary equipment constructed as described above will be described. When the engine 1 is stopped, the discharge passage 4 of the hydraulic pump 2 shown in FIG.
Since the pressure in 6 is atmospheric pressure, the control cylinder 4
3 is in the inoperative state, and the swash plate 35 is in the minimum capacity state in which the minimum inclination angle (0.1 to 4 °) equal to zero capacity is maintained by the return spring 42.

Here, when the engine 1 is started in FIG. 1, the rotary shaft 29 of the hydraulic pump 2 is rotated via the drive pulley 3, the V belt 5, and the driven pulley 4. Then,
In FIG. 2, the cylinder block 32 is rotated, the working piston 36 in the cylinder bore 33 is reciprocated according to the tilt angle of the swash plate 35, and the working oil sucked from the suction port 38 is discharged from the discharge port 39 to the discharge passages 41, 46. Discharge to the pipe line 6. At this start-up, the swash plate 35 has the minimum inclination angle due to the biasing force of the return spring 42, so the start-up torque of the pump 2 is small and the power consumption is small.

The oil discharged from the hydraulic pump 2 is supplied to the hydraulic motor 8 through the discharge pipe line 6 at the same time as this starting state, so that the hydraulic motor 8 is rotated at a low speed by a small amount of oil. Therefore, each auxiliary device such as the hydraulic pump 9, the alternator 15 and the compressor 18 for the power steering device shown in FIG. 1 is started at a low speed. Therefore, the rotational torque required for starting the engine 1 is minimized, and the starting shock of the engine 1 is alleviated.

Although a small amount of oil is discharged from the hydraulic pump 2 when the engine 1 is started, the discharge pressure P _d in the discharge passage 46 rises due to the operating load of the hydraulic motor 8. At the same time, the control oil pressure P _C supplied to the control cylinder 43 via the control passage 48 also increases, so that the swash plate 35 is pressed by the forward movement of the control piston 44 against the urging force of the return spring 42 to increase its inclination angle. To be done. That is, the hydraulic pump 2 rises from the minimum capacity equal to zero, the swash plate 35 shifts to a large capacity steady operation, the hydraulic motor 8 is rotated at a high speed, and each auxiliary device 9, 15, 18, 23 is rotated normally. Rotated at speed.

By the way, the rotational speed of the engine 1 is increased or decreased in order to adjust the traveling speed of the vehicle. Therefore, when the rotation speed of the engine 1 changes while the inclination angle of the swash plate 35 of the hydraulic pump 2 is maintained in the same state, the amount of oil discharged from the hydraulic pump 2 changes. However, in this embodiment, the discharge oil amount control mechanism K centering on the displacement control valve 49 controls the discharge oil amount to be substantially constant as follows.

In FIG. 4, the discharge passages before and after the diaphragm 47 are shown.
The path 46 has a difference depending on the amount of oil discharged from the hydraulic pump 2.
Pressure is generated. This pressure difference is due to the first and second pilot oils.
Road P ₁, P₂Through the first and second pressure sensing chambers R₁, R₂
Act on. Therefore, the spool 51 of the capacity control valve 49
With the differential pressure acting before and after that and the urging force of the spring 52,
The movement of the control passage 48 is adjusted to a balanced position
Is adjusted. That is, the discharge amount of the hydraulic pump 2 increases
As the differential pressure increases, the first pressure sensing chamber R in FIG.
₁Pressure increases and the spool 51 opens the opening of the control passage 48.
Control oil pressure P acting on the control cylinder 43_CBut
Since the inclination angle of the swash plate 35 is reduced,
The discharge capacity of the nozzle 2 is reduced. On the contrary, the discharge of pump 2
When the capacity decreases and the differential pressure decreases, the spool 51
Increases the opening degree of the control passage 48 and operates the control cylinder 43.
Control oil pressure P to be used_CThe inclination angle of the swash plate 35
Is controlled to increase the pump discharge capacity.
Be done. Since this operation is repeated, the hydraulic motor 8
The amount of oil supplied to the auxiliary devices 9, 15 and
The rotation speeds of 18 and 23 are controlled to be substantially constant.

By the way, the rotational speed of the engine 1 is 80
It varies from 0 to 6500 rpm. This rotation is decelerated and transmitted to the hydraulic pump 2. Here, if the pulley ratio N between the drive pulley 3 and the driven pulley 4 is 0.8, the hydraulic pump 2 is rotated at 640 to 5200 rpm. Further, as described above, the hydraulic pump 2 is controlled so that the discharge oil amount is substantially constant even if the rotation speed of the engine 1 changes. Therefore, the hydraulic motor 8 is set to rotate at a constant speed of, for example, 1400 rpm by this constant amount of oil. This rotation speed is for compressor 1
8 is the second drive pulley 19 and the third driven pulley 21a.
If the pulley ratio N of and is set to 1.3, the optimum rotation speed is increased to 1800 rpm and transmitted. Similarly, by appropriately setting the pulley ratio, the optimum rotational speed of 1000 rpm is transmitted to the hydraulic pump 9 of the power steering device, the optimal rotational speed of 3000 rpm is transmitted to the cooling fan 23, and the optimal rotational speed of 3500 rpm is transmitted to the alternator 15.

As described above, the rotation speed of the alternator 15 is 6000 rpm (currently the engine 2400 rp).
m) or more has a characteristic that the output is saturated. For example, if the engine rotates at a constant speed of 3500 rpm, the output of 40 to 55 A can always be secured, and an unreasonable high speed (engine 2400 to 40
The alternator 15 is 6000 to 1000 at 00 rpm.
(0 rpm) operation is avoided, and advantages such as reduction in capacity of the alternator 15 and extension of life of bearings and the like occur.

The hydraulic pump 9 of the power steering system has an engine speed of 1000 rp as shown in FIG.
At low speed per m, maximum flow rate (7-8 liters / mi
n) is required, and in the middle and high speed ranges, as shown by the curve L, an appropriate amount of bypass from the discharge side to the suction side of the pump 9 is used to obtain a low discharge flow rate characteristic of the pump 9. That is,
Since the hydraulic pump 9 works according to its capacity, the power loss is large. In the embodiment of the present invention, the power steering pump 9 remains at 1 even if the engine speed changes.
Since it becomes constant at 000 rpm (the amount of discharged oil is 7 to 8 liters / min), the wasteful work is completely eliminated, which is advantageous in terms of power saving.

Further, since the compressor 18 is also operated at a constant rotation speed of 1800 rpm, which is highly efficient in conjunction with the rotation speed of the engine 1, power saving and cooling feeling represented by blowout temperature are greatly improved.

Next, a second embodiment of the invention as defined in claim 2 will be described with reference to FIG. In the second embodiment, a flow divider 60 is interposed in the discharge pipe line 6 connecting the hydraulic pump 2 to the hydraulic motor 8. An operating cylinder 61 of the power steering device is connected to the flow divider 60 by a conduit 62. The cylinder 6
The oil discharged from No. 1 is returned from the pipe 63 to the suction pipe 7.

Therefore, in this second embodiment, the hydraulic pump 2
It is possible to preferentially supply an appropriate amount of a part of the discharged oil of the above to the operating cylinder 61 for the power steering device, and the hydraulic pump 9 of the power steering device of the first embodiment can be omitted. Also, since the pump 9 can be omitted,
The capacity of the hydraulic motor 8 can be reduced, and the cost can be reduced.

Next, a third embodiment of the invention as defined in claim 3 will be described with reference to FIG. In this third embodiment, the flow divider 60 is incorporated in the hydraulic motor 8. Therefore, in this embodiment, it is possible to further reduce the cost by reducing the number of holding members of the flow divider 60, the number of pipes, the number of joints and the like.

The present invention is not limited to the above embodiment, but can be embodied as follows. (1) Although not shown, the output shaft of the engine 1 is connected to the rotary shaft 29 of the hydraulic pump 2 via a joint, or the engine 1
The hydraulic power pump 2 is driven by a power take-out device provided in the transmission driven by.

(2) The flow divider 60 is installed on the hydraulic pump 2 side. In this embodiment, the pipe pressure loss is reduced and the efficiency is improved.

[0042]

As described above in detail, according to the first aspect of the present invention, the auxiliary equipment such as the compressor, the hydraulic pump for the power steering device, the cooling fan or the alternator is optimally rotated regardless of the fluctuation of the engine rotation speed. There is an effect that can be driven by.

In addition to the effect of the invention described in claim 1, the invention described in claim 2 can omit the hydraulic pump for the power steering device, and can downsize the hydraulic motor. At the same time, there is an effect that the cost can be reduced.

Further, the invention according to claim 3 is the same as claim 2
In addition to the effects of the invention described above, there is an effect that the number of holding members of the flow divider, the number of pipes, the number of joints and the like can be reduced to further reduce the cost.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing a first embodiment of a hydraulic drive system for an auxiliary device for a vehicle, which embodies the invention according to claim 1;

FIG. 2 is a vertical sectional view of a minimum capacity start-up hydraulic pump.

FIG. 3 is a hydraulic circuit diagram showing a discharge oil amount control mechanism of a hydraulic pump.

FIG. 4 is a cross-sectional view of a capacity control valve.

FIG. 5 is a graph showing a relationship between an engine speed and a discharge oil amount of a hydraulic pump of a power steering device.

FIG. 6 is a schematic plan view showing a second embodiment embodying the hydraulic drive system according to the second aspect of the present invention.

FIG. 7 is a schematic plan view showing a third embodiment in which the hydraulic drive system according to the third aspect of the invention is embodied.

[Explanation of symbols]

1 engine, 2 hydraulic pumps, 6 discharge lines, 8 hydraulic motors, 9 hydraulic pumps for power steering devices, 11 first drive pulleys, 13 first driven pulleys, 1
4 1st V-belt, 15 alternator, 17 2nd driven pulley, 18 compressor, 19 2nd drive pulley, 22
2nd V belt, 23 cooling fan, 24 4th driven pulley, 42 return spring, 43 control cylinder, 44
Control piston, 48 control passage, 49 displacement control valve,
60 flow divider, 61 working cylinder of power steering device, K discharge oil amount control mechanism.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeru Suzuki 2-chome Toyota-cho, Kariya city, Aichi stock company Toyota Industries Corp.

Claims (3)

[Claims] 1. A minimum capacity start-up hydraulic pump is operatively connected to an engine, a discharge oil amount control mechanism for controlling the discharge oil amount to a substantially constant value is provided to the hydraulic pump, and a hydraulic motor is connected to the hydraulic pump. A plurality of auxiliary devices such as a compressor of a vehicle air conditioner, a hydraulic pump of a power steering device, a cooling fan, and an alternator are operatively connected to the output shaft of the hydraulic motor via a pulley and a belt, and the pulley ratio is A hydraulic drive system for vehicle auxiliary equipment in which is set to a value that provides optimum rotation of each auxiliary equipment. 2. A minimum capacity start-up hydraulic pump is operatively connected to the engine, a discharge oil amount control mechanism for controlling the discharge oil amount to be substantially constant is provided to the hydraulic pump, and a hydraulic motor is connected to the hydraulic pump. A plurality of auxiliary devices such as a compressor, a cooling fan, or an alternator of a vehicle air conditioner are operatively connected to the output shaft of the hydraulic motor via pulleys and belts, and the pulley ratio is set to the optimum rotation of each auxiliary device. And a flow divider interposed in the discharge pipe from the hydraulic pump to the hydraulic motor, and the actuation cylinder of the power steering device is connected to the flow dividing port of the flow divider. . 3. The hydraulic drive system for a vehicle auxiliary device according to claim 2, wherein a flow divider is attached to the hydraulic motor.