JPH04331858A - Compressor equipped with transmission for air-conditioning automobile - Google Patents

Abstract

PURPOSE:To control the temperature of the lubricating oil in a transmission to an optimum value so that the power transmission efficiency of a frictional type continuously variable transmission for driving the coolant compressor for an air conditioner of an automobile becomes max. CONSTITUTION:A frictional type continuously variable transmission 2 driven by the engine 9 of an automobile is controlled by a controller 14, and a coolant compressor 1 is driven at the number of revolution corresponding to the coolant flow rate for generating the cooling faculty necessary at that time. As for the temperature of the lubricating oil for lubricating and cooling the engagement surface of a frictional wheel made of metal in the transmission 2, the power transmission efficiency is reduced at the higher or lower temperature than a specific optimum temperature, and the lubricating oil is allowed to flow from an oil pump 17 to a cooling circuit 16 having an oil cooler 18, and each number of revolution of the oil pump 17 and a fan motor 20 is controlled so that an oil temperature sensor 19 detects the optimum temperature.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerant compressor driven by a friction type continuously variable transmission and suitable for use as a refrigerant compressor for an automobile air conditioner.

0002

[Prior Art] As a problem peculiar to automobile air conditioners,
The air conditioner is driven by the car's engine, and the engine speed changes over a wide range depending on the car's driving conditions. Therefore, if the air conditioner's refrigerant compressor is directly connected to the engine, Since the temperature depends on the driving conditions of the car, an electromagnetic clutch is usually inserted between the refrigerant compressor and the output shaft of the engine in order to keep the temperature inside the vehicle constant regardless of the driving conditions. The compressor is driven intermittently to maintain a substantially constant cabin temperature.

[0003] In such conventional technology, control by intermittent drive of the compressor is to intermittently lower the temperature in the vehicle interior, thereby maintaining the target temperature while the temperature repeats ups and downs. Strictly speaking, it is not possible to maintain a constant temperature, and delicate temperature control is also not possible with this method. Therefore, by interposing a continuously variable transmission between the engine and the refrigerant compressor and making it possible to control the rotation speed of the compressor steplessly, the gear ratio can be changed in response to changes in the engine rotation speed. One idea was to adjust the rotation speed of the compressor to a value that would provide the required cooling capacity at that time, and also to save power consumption. JP-A No. 60-245868 and Utility Model Application No. 61-
97658, which can be used for such purposes,
A planetary friction type continuously variable transmission consisting of several conical friction wheels, rings, etc. is described.

0004

[Problem to be solved by the invention] In a continuously variable transmission in which metal friction wheels (including rings) are engaged with each other, it is necessary to prevent wear and galling of the friction engagement surfaces and to cool the friction wheels. In order to remove the heat generated by the friction of the engagement surfaces, a relatively large amount of lubricating oil is supplied to the friction engagement surfaces, but the lubricating oil lubricates the friction engagement surfaces and cools them at the same time. Therefore, it is necessary to release the heat absorbed by the lubricating oil to the outside. In the above-mentioned conventional technology, a cooling fan is provided in the continuously variable transmission, and the lubricating oil is cooled by driving the cooling fan with an input shaft or an output pulley. However, it has been found that the mechanical characteristics of the transmission itself change significantly depending on the degree of cooling of the lubricating oil.

FIG. 2 shows the temperature of the lubricating oil on the horizontal axis and the continuously variable transmission on the vertical axis, based on test results for a planetary friction type continuously variable transmission consisting of several conical friction wheels, rings, etc. This figure shows the change in transmission efficiency with respect to temperature, taking the power transmission efficiency of the transmission. The test results revealed that there is a clear functional relationship between the power transmission efficiency of continuously variable transmissions and lubricant temperature, and that there is a maximum value for transmission efficiency, and the state in which the maximum value is reached. If the oil temperature is TO, the transmission efficiency will decrease whether the oil temperature is higher or lower than TO, and if the oil temperature exceeds the temperature shown as Tmax, gross slip (slip ratio 100%) will occur.
This means that no power can be transmitted at all.

The reason why the transmission efficiency decreases in a region where the oil temperature is low is considered to be that as the temperature decreases, the viscosity of the lubricating oil increases, resulting in an increase in fluid friction (viscous resistance) and a large power loss. On the other hand, a decrease in transmission efficiency is observed even in areas where the oil temperature is high.As the viscosity decreases as the oil temperature increases, the shear strength of the oil that exists between the friction transmission surfaces decreases, and the sliding speed increases. As a result, the transmission efficiency tends to decrease, and furthermore, in a region exceeding Tmax, it is considered that a complete slipping state occurs, making it impossible to transmit power.

From this point of view, the present invention aims to maintain the temperature of lubricating oil at an optimum value such as TO shown in FIG. 2 for a friction type continuously variable transmission that drives a compressor for automobile air conditioning. An object of the invention is to enable the continuously variable transmission to always drive the compressor with the highest transmission efficiency by providing a means for doing so.

[0008]

[Means for Solving the Problems] The present invention provides a compressor for compressing refrigerant in an automobile air conditioner, and a compressor for driving the compressor by the engine for driving the automobile. a friction type continuously variable transmission that is interposed between the compressor and the engine and controls the driving rotation speed of the compressor; and a lubricating oil that lubricates the frictional engagement surfaces of the friction type continuously variable transmission. a cooling circuit connected to the transmission chamber of the friction type continuously variable transmission; an oil cooler inserted into the cooling circuit; and an oil pump installed in the cooling circuit in series with the cooling circuit. , an oil temperature sensor that detects the temperature of lubricating oil in a cooling circuit extending from the transmission room to the oil cooler, and maintaining the temperature of the lubricating oil at a predetermined value by inputting a detection signal from the oil temperature sensor. The present invention provides a compressor with a transmission for automobile air conditioning, characterized in that the compressor is equipped with a control device for changing the cooling capacity of lubricating oil in the oil cooler.

In addition to the detection signal of the oil temperature sensor in the above-mentioned means, the present invention also includes inputting a rotation speed signal of the compressor and a rotation speed signal of an engine that drives the compressor to the control device. 2. The vehicle according to claim 1, wherein the lubricating oil cooling capacity of the oil cooler is corrected so that the higher the rotation speed, the lower the temperature of the lubricating oil detected by the oil temperature sensor. The Company also provides compressors with variable speeds for air conditioning.

0010

[Function] When the refrigerant compressor of an automobile air conditioner is driven by the automobile's engine, the cooling capacity fluctuates depending on the engine speed, which changes depending on the driving condition. By changing the gear ratio of the installed friction-type continuously variable transmission in response to changes in engine speed, the compressor speed can be adjusted to a value commensurate with the refrigerant flow rate that provides the required cooling capacity at that time. You can always get just the right air conditioning effect. However, it has been confirmed that the transmission efficiency of friction-type continuously variable transmissions is significantly affected by the temperature of the lubricating oil supplied to lubricate and cool the engagement surfaces of the metal friction wheels of friction-type continuously variable transmissions. It was found that the transmission efficiency decreases even if the temperature is lower or higher than a specific optimum temperature, and that a gross slip condition occurs when the temperature exceeds a specific temperature. The oil pump sends lubricating oil from the transmission chamber of the gearbox to the oil cooler in the cooling circuit, and the control device cools the lubricating oil in the oil cooler so that the lubricating oil temperature detected by the oil temperature sensor maintains the optimum temperature. Adjust your abilities.

[0011] When the load of the friction type continuously variable transmission changes,
Since the temperature of the lubricating oil on the engagement surface of the friction wheel may temporarily show a value different from the value detected by the oil temperature sensor, according to the second means of the present invention, in addition to the value detected by the oil temperature sensor, hand,
The rotation speed of the compressor, that is, the output rotation speed of the friction type continuously variable transmission, is detected and input to the control device.The higher the rotation speed of the compressor, the lower the temperature of the lubricating oil detected by the oil temperature sensor. By controlling as described above, it becomes possible to accurately maintain the temperature of the lubricating oil at the engagement surface of the friction wheel at the optimum temperature.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an example of the entire system of an automobile air conditioner equipped with a compressor according to the present invention, in which 1 is a refrigerant compressor integrated with a friction-type continuously variable transmission 2, 3 is a condenser, 4 is a liquid receiver, 5 is an expansion valve, 6 is an evaporator, 7 is a blower fan therefor, 8 is a temperature sensor that detects the temperature of the blown air, 9
10 is a crank pulley, 11 is a transmission belt, 12 is a transmission drive pulley, and 13 is a rotational speed sensor for detecting the rotational speed of the engine 9. Reference numeral 14 denotes an automatic control device such as an electronic control device, into which signals from the operating section 15, signals detected by the temperature sensor 8, the rotational speed sensor 13, and the like, as well as signals described below are input.

FIG. 4 shows an embodiment of only the main body portion of a compressor with a friction type continuously variable transmission for automobile air conditioning according to the present invention. In the figure, 100 indicates a vane type compressor as an example of the compressor 1 in FIG. 1, and 200 indicates several planetary friction wheels 2 as an example of the friction type continuously variable transmission 2 in FIG.
02 with one ring 204 and one input friction wheel 206 each
and a friction type continuously variable transmission engaged with an output friction wheel 208. Although the basic configurations of the vane compressor 100 and the continuously variable transmission 200 having a planetary friction wheel have been known, the basic configurations thereof will first be explained here.

A space 102 formed in the front housing 150 of the compressor 100 with a continuously variable transmission is connected to the partition wall 24.
0, it is divided into a suction chamber 104 and a transmission chamber 230, and the transmission chamber 230 is configured with a friction-type continuously variable transmission mechanism as described below, and also contains lubricating oil for the transmission up to a predetermined level. are doing. The suction chamber 104 of the compressor 100 receives low-temperature, low-pressure refrigerant from the evaporator 6 described above, and the vane 1 forming the working chamber of the compressor 100 enters the intake passage 114.
A discharge passage 108 is provided in the high-pressure chamber 106 on the discharge side, and the high-temperature and high-pressure refrigerant is sent to the condenser 3 described above. Hyperbaric chamber 106
The lower region of the oil separation chamber 110 forms an oil separation chamber 110, in which refrigerating machine oil separated from the discharged high-temperature, high-pressure refrigerant due to differences in specific gravity, etc., is collected at the bottom.

Since the refrigerating machine oil accumulated in the oil separation chamber 110 has the discharge pressure of the pressurized refrigerant, if the differential pressure with the suction side is used, the refrigerating machine oil can be removed without installing a special oil pump. It can be circulated to vane sliding surfaces, bearings, etc. As one example, a series of communication holes 120 provided in the center housing 140 and the like of the compressor 100 is an example of a path for sending refrigerating machine oil from the oil separation chamber 110 to the bearing 242 of the boss portion 142. Note that 132 in FIG. 4 indicates a shaft seal for preventing refrigerating machine oil from leaking into the transmission chamber 230.

At the center of the friction type continuously variable transmission 200 is a pulley 214 (corresponding to the pulley 12 in FIG. 1) which is rotationally driven from the automobile engine via a belt as described above.
The input shaft 216 is supported by a bearing 218 and is connected to a transmission chamber 230.
Inside, it is screwed to a disc-shaped input friction wheel 206 fixed to the input shaft 216. In addition, the input friction wheel 20
A cam disk 250 is supported on the hub of No. 6 by a radial bearing 222 and a thrust bearing 220. On the right end surface of the cam disc 250, there is an output rotation detection ring 2.
52, the compressor 100 is connected by splines 134.
A disk 210 is attached to the shaft 130 of the disk 210 and connected by a bolt 254.

Further, the cam disk 250 supports the output friction wheel 208 from behind via a known thrust generating cam mechanism 256. The output friction wheel 208 is the cam disc 2
It is loosely fitted onto the cylindrical portion of the cam disk 250 so as to be relatively rotatable, and as the relative rotation angle with respect to the cam disk 250 increases, it is strongly pushed forward in the axial direction by the thrust generating cam mechanism 256, and each planetary friction It acts to increase not only the frictional contact force of the output friction wheel 208 with respect to the wheel 202 but also that of the input friction wheel 206 and the ring 204.

The carrier 258, which can freely rotate between the input friction wheel 206 and the output friction wheel 208, allows the rotation axes of several planetary friction wheels 202 to be arranged on the same circumference at equal intervals, and the input shaft 216, and a common ring 204 is frictionally engaged with each conical friction surface of these planetary friction wheels 202. Although the ring 204 is prevented from rotating, it can be moved and adjusted in the axial direction by the speed change operating mechanism 260.
As a result, the effective radius of the engagement point with the ring 204 on the conical friction surface of each planetary friction wheel 202 changes simultaneously. The input friction wheel 206 is simultaneously frictionally engaged with the cylindrical friction surface formed at the base of each planetary friction wheel 202, and the output friction wheel 208 is simultaneously engaged with the disc-shaped friction surface corresponding to the conical bottom. By simultaneously engaging in friction, a planetary friction type continuously variable transmission 200 is constructed.

In the operating state, when the pulley 214 is rotationally driven by the engine 9, the input friction wheel 206 integrated with the input shaft 216 rotates, causing the planetary friction wheel 202 to roll along the stationary ring 204. As a result, rotation is extracted to the output friction wheel 208. When the rotation speed of the input friction wheel 206 is constant, the rotation speed of the output friction wheel 208 is determined by the rotation speed of the ring 2 positioned by the speed change operation mechanism 260.
It is determined by the axial position of 04. Therefore, when the ring 204 is moved in the axial direction by the speed change operation mechanism 260, the rotation speed of the output friction wheel 208 changes steplessly. Conversely, the input friction wheel 20 along with the engine 9 and the input shaft 216
Even when the rotation speed of the compressor 1 changes, if the friction type continuously variable transmission 200 is operated to change the speed according to the change, the rotation speed of the compressor 1 changes.
It becomes possible to maintain the rotational speed of the 00 shaft 130 almost constant. Due to this action, the compressor with a variable transmission always compresses and discharges the required flow rate of refrigerant even if the engine speed fluctuates, making it possible to ideally control the cooling capacity.

The friction type continuously variable transmission 2 which is an embodiment of the present invention shown in FIG. When the continuously variable transmission 2 is specifically a continuously variable transmission 200 having a planetary friction wheel 202 and a ring 204 as shown in FIG. It is designed to move. Therefore, when the rotational speed of the vehicle running engine fluctuates depending on the driving conditions, the control device 14 changes the gear ratio of the transmission 2 to compensate for the fluctuation, and the compressor 1 only provides the necessary cooling capacity. The rotational speed is adjusted to a rotation speed (calculated by the control device 14) that can generate a refrigerant flow rate of .

As described above, the use of the compressor 100 driven by a continuously variable transmission having a planetary friction wheel as a refrigerant compressor for a vehicle air conditioner belongs to the prior art, but FIGS. In the embodiment of FIG. 4, in addition to the configuration described above, a special means for cooling the lubricating oil in the transmission chamber 230 and a control for adjusting the degree of cooling are provided in accordance with the features of the present invention. and means. That is, a lubricating oil cooling circuit 16 is connected to the transmission chamber 230, and an oil pump 17 and an oil cooler 18 as a heat exchanger are arranged in series in the cooling circuit 16. An oil temperature sensor 19 is provided in a part of the cooling circuit 16 from the friction type continuously variable transmission 2 to the oil cooler 18.
The temperature of lubricating oil sent from 30 to oil cooler 18 is detected and the signal is input to control device 14. In the example shown in FIG. 4, an oil temperature sensor 270 is inserted and screwed into the transmission chamber 230. The oil cooler 18 is cooled by a cooling fan 21 driven by a motor 20.

The rotation speed of the oil pump 17 and the fan motor 20 is controlled by control signals issued by the control device 14, respectively. Therefore, the oil is sent from the transmission chamber 230 to the oil cooler 18 and circulated through the cooling circuit 16.
The flow rate of the lubricating oil to be cooled and the amount of cooling air sent to the oil cooler 18 by the cooling fan 21 can be adjusted by the control device 14, and the control device 14 can automatically change the rotation speed of both or one of them. By, transmission room 2
The temperature of the lubricating oil in the friction type continuously variable transmission 2 (in this example, the continuously variable transmission 200) is adjusted so that it becomes the optimum temperature TO at which the friction type continuously variable transmission 2 (in this example, the continuously variable transmission 200) provides maximum power transmission efficiency, as shown in FIG. be done.

Specific control means for controlling the cooling capacity of the oil cooler 18 by adjusting the rotation speed of the oil pump 17 or fan motor 20 that circulates and cools the lubricating oil of the friction type continuously variable transmission 2 is as follows. Adjustment methods such as voltage control, current control, ON-OFF control with hysteresis, and stepwise control between these methods are used for the power supplied to these motors, but the rotation speed control itself by these means Since these are well-known techniques, detailed explanation thereof will be omitted.

In this case, even if the average lubricating oil temperature detected by the oil temperature sensor 19 is the same, the friction type continuously variable transmission 2
The greater the power transmitted at that time, the greater the load on the friction type continuously variable transmission 2, and the greater the heat generation of the power transmission portion inside the transmission, so the value of the optimum temperature TO also changes somewhat depending on the load conditions. In order to cope with such changes, in addition to detecting the lubricating oil temperature of the friction type continuously variable transmission 2 by the oil temperature sensor 19 (270 in the example of FIG. 4), the rotation speed sensor 22 provided in the compressor 1 The rotation speed of the compressor 1 is also detected and inputted to the control device 14, and as shown by the broken line in FIG. When the load is larger than a predetermined value, the cooling capacity of the oil cooler 18 is corrected to be larger. However, rather than selecting whether to take the solid line or the broken line in FIG. 3 depending on whether the rotation speed of the friction type continuously variable transmission 2 is smaller or larger than a predetermined value, it is better to It goes without saying that it is desirable to perform control over a region between the solid line and the broken line.

Furthermore, even if the power to be transmitted is the same, if the gear ratio is small, the transmission efficiency will decrease and the amount of heat generated will increase. Correct to increase cooling capacity.

In the above description, a combination of a vane-type positive displacement compressor 100 and a continuously variable transmission 200 having a planetary friction wheel as shown in FIG. 4 is taken up as a specific example. However, in the present invention, the compressor and the friction type continuously variable transmission are not limited to these types, and as is clear from the characteristics of the present invention, other types of refrigerant compressors and friction type Needless to say, the invention can also be applied in combination with a continuously variable transmission.

[0027]

Effects of the Invention According to the present invention, a specific lubricating oil temperature is maintained at which the power transmission efficiency of the friction type continuously variable transmission is maximized, so that the friction type continuously variable transmission always uses the least amount of power.
Drives the refrigerant compressor of an automobile air conditioner without slipping. Power is then transmitted from the friction type continuously variable transmission to the refrigerant compressor at the required rotational speed, regardless of the driving condition.
Since the refrigerant flow rate is just the right amount to match the cooling capacity required at that time, comfortable air conditioning is achieved in the interior of the vehicle, and no power is wasted.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram illustrating the overall configuration of an air conditioner using a compressor with a friction type continuously variable transmission according to the present invention.

FIG. 2 is a diagram showing the relationship between oil temperature and power transmission efficiency in a friction type continuously variable transmission.

FIG. 3 is a diagram showing an example of control according to the invention.

FIG. 4 is a sectional view showing a specific example of a friction type continuously variable transmission used in the compressor of the present invention.

[Explanation of symbols]

1,100...Compressor 2,200...Friction type continuously variable transmission 9...Automotive engine 14...Control device 16...Cooling circuit 17...Oil pump 18...Oil cooler 19, 270...Oil temperature sensor 20...Fan motor 21...Cooling fan 22...Rotation speed sensor 23... Actuation device 104...Suction chamber 202...Planetary friction wheel 204...Ring 206...Input friction wheel 208...Output friction wheel 230...Transmission room 240...Bulkhead 260...speed change operation mechanism

Claims (2)

[Claims] 1. A compressor for compressing refrigerant in an air conditioner for an automobile; and a compressor for driving the compressor, the compressor being interposed between the compressor and the engine for driving the compressor by the engine for driving the automobile. A friction type continuously variable transmission for controlling the number of revolutions, and a lubricating oil that lubricates the frictional engagement surfaces of the friction type continuously variable transmission. Lubricating in a cooling circuit provided, an oil cooler inserted into the cooling circuit, an oil pump provided in the cooling circuit in series with the cooling circuit, and a cooling circuit extending from the transmission room to the oil cooler. an oil temperature sensor that detects oil temperature; and a control device that changes the lubricating oil cooling capacity of the oil cooler in order to maintain the lubricating oil temperature at a predetermined value by receiving a detection signal from the oil temperature sensor. A compressor with a transmission for automotive air conditioning, characterized by comprising: 2. In addition to the detection signal of the oil temperature sensor,
Either one of the rotation speed signal of the compressor and the rotation speed signal of the driving engine is input to the control device to correct the lubricating oil cooling capacity in the oil cooler, so that the rotation speed of the compressor is high. The compressor with a transmission for automobile air conditioning according to claim 1, characterized in that the temperature of the lubricating oil detected by the oil temperature sensor becomes lower as the temperature of the lubricating oil increases.