JPH04331455A - Variable speed clutch - Google Patents

Abstract

PURPOSE:To prevent overspeed operation of compressor, to save operating energy, to enhance acceleration performance of vehicle and controllability of room temperature, and to reduce the size, the weight and the cost of compressor by arranging a variable speed clutch in the power transmission system for driving the compressor of car cooler through an engine. CONSTITUTION:A plurality of permanent magnets 2 are fixed to a drive pulley 1 being driven through a V-belt. An electromagnetic core 4 is secured to the outer periphery of a driven pulley 3 directly coupled with the main shaft 9 of compressor and a plurality of coils 5 are placed in grooves 17 made, with same intervals, in the outer periphery of the electromagnetic core 4. The coils 5 are arranged to be opened/closed, at the opposite ends thereof, through a switching element 6 such as a thyristor or a transistor and the switching element 6 is subjected to chopper control through an electronic control means such as a computer.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention applies a compressor used in a type of car cooler (automobile cooling device) that compresses, liquefies, and evaporates refrigerant such as fluorocarbons to a power transmission system driven by an engine. The present invention relates to a variable speed clutch for achieving a gear ratio of .

0002

2. Description of the Related Art Conventionally, as shown in FIG. 10, a compressor used in a car cooler is driven by an engine. As shown in FIG. When the electromagnetic clutch 10 is energized, the friction clutch plates in the electromagnetic clutch come into contact and the power is transmitted to the main shaft 9 of the compressor.

[0003] The engine of an automobile is operated at a rotational speed necessary for driving the automobile. For example, from idling at about 500 rpm when stopped, rapid changes in rotation when accelerating to start, frequent changes in rotation when driving around town, continuous driving at about 3,500 rpm when driving on a highway, and 6,000 rpm when overtaking or accelerating. It covers a wide range of speeds, including high rotations that reach up to Therefore, the rotation of the compressor, which can be said to be almost directly connected to the engine, also changed significantly.

[0004] Therefore, since the cooling capacity of the car cooler changes from moment to moment, the temperature inside the vehicle also changes greatly.

[0005]

[Problem to be Solved by the Invention] Normally, the capacity of the compressor is selected to be large enough to provide the necessary cooling capacity when driving at low speeds in urban areas on sunny days in summer, and the required driving force at this time is It has about 2 horsepower. Therefore, when the outside temperature is slightly low or the sunlight is weak, or when driving at medium speeds on suburban roads where the engine speed is higher than that, the cooling capacity tends to become excessive. Additionally, when operating conditions result in excessive cooling capacity, the power consumed to operate the compressor is greater than the amount required by the car cooler system, resulting in unnecessary power load on the engine. This caused increased fuel consumption.

[0006] In particular, when the vehicle continues to travel at high speeds, the engine continues to rotate at high speeds, resulting in extremely large power losses, sometimes reaching as much as 7 horsepower. At the same time, the cooling capacity of the car cooler becomes excessive, which causes the pressure inside the car cooler's refrigeration (evaporator) to drop, and the surface of the cooler becomes colder, causing the moisture in the air to form frost or ice, causing the air to cool down. This blocked the flow of water and caused various problems.

As a countermeasure, when the pressure inside the cooler (=suction pressure of the compressor) becomes low, methods such as bypassing the high pressure gas on the discharge side of the compressor to the suction side using an expensive special control valve are taken. However, in that case, there was a problem in that the power consumption of the compressor increased.

Furthermore, when the cooling capacity of a car cooler is excessive, a control method is sometimes used in which the electromagnetic clutch is turned off to stop the compressor. As a result, the interior of the vehicle becomes highly humid, and unpleasant odors are emitted, which impairs comfort.

In any case, in conventional car coolers, the rotational speed (=cooling capacity) of the compressor is determined by the traveling speed of the car, and the rotational speed (=cooling capacity) of the compressor is determined by the driving speed of the car, and is based on factors such as outside temperature, solar radiation, and heat generation inside the vehicle, which should be important for cooling. Since the vehicle operates independently of the heat load of the vehicle, it is extremely difficult to control the interior environment to a desirable one using auxiliary control means.

0010

[Means for Solving the Problems] In order to solve these problems, the present invention provides a variable speed clutch in the power transmission system of an automobile engine and a compressor.
This prevents the compressor from rotating at excessive speed, and at the same time reduces operating energy, improves vehicle acceleration, improves controllability of vehicle interior temperature, and makes the compressor smaller, lighter, and less expensive. That is, as shown in FIGS. 1 to 4, a plurality of permanent magnet magnetic poles 2 are attached to the drive pulley 1, and an electromagnetic core 4 is attached to the outer periphery of the passive pulley 3, and the magnetic poles 2 are formed at equal intervals on the outer periphery of the electromagnetic core 4. This is a variable speed clutch in which a plurality of coils 5 are wound around a groove 17, and terminals of the coils 5 can be short-circuited and opened by a switching element 6. The drive pulley 1 is supported by the compressor main body 12 via a ball bearing 13, and is also supported concentrically by the main shaft 9 of the compressor via a ball bearing 14. Furthermore, an electric resistance 15 is connected in series with the coil 5.
By connecting , you can change the total resistance of the coil system, thereby adjusting the magnitude of the transmitted torque,
The location of heat generation can be adjusted. Further, the connection combination between the coil 5 and the switching element 6 can also be performed via a rectifier diode 16 as shown in FIG.

[0011]

[Embodiment] When this clutch is used in a car cooler, as shown in FIGS. 1 to 5, the driving pulley 1 is driven by an automobile engine 7 via a V-belt 8, and the passive pulley 3 is connected to the main shaft 9 of a refrigerant compressor. A car cooler system is constructed by combining the following, and at least one value or all values of engine rotational speed a, car cooler cooler temperature or pressure b, vehicle interior temperature c, and rotational speed d of the passive pulley 3 are input to a computer. The gear change operation is performed by inputting the input information and opening and closing the switching element 5 according to a preset program.

The present invention will be explained in detail below based on FIGS. 1 to 5. The electromagnetic core 4 has a groove 17 that penetrates in the axial direction.
A plurality of coils 5 are provided at equal intervals, and the coil 5 is wound around them. The magnetic poles 2 of the permanent magnet attached to the drive pulley 1 are arranged such that the N and S portions of the magnetic poles are arranged alternately in the groove 1 of the electromagnetic core 4.
It is arranged to correspond to 7. The structure of the groove 17 formed in the electromagnetic core 4 and the winding method of the coil 5, as well as the configuration in which the N and S of the magnetic poles 2 of the permanent magnet correspond to the grooves 17 of the electromagnetic core 4, are normally implemented in a three-phase alternating current generator. It is based on the same principle as the one described above, except that the magnetic poles and coils are arranged geometrically opposite inside and outside.

As the switching element 6, a thyristor, a transistor, or the like having a function of cutting off and connecting current at high speed is used. Signals are transmitted from a computer (not shown) to the switching element 6 that instructs the opening/closing operation of the switching element 6 via radio waves or a slip ring attached to a passive pulley.

[0014]

[Operation] In FIGS. 1 to 5, when the automobile engine rotates and the drive pulley 1 is rotated by the V-belt, the magnetic pole 2 of the permanent magnet attached to the drive pulley 1 is attached to the outer periphery of the passive pulley 3. Since a rotating magnetic field is formed in the coil 5, a voltage is induced in the coil 5 intersecting the lines of magnetic force. This operation is the same as the principle of construction of a general wire-wound three-phase induction motor. However, in general wire-wound three-phase induction motors, the rotating magnetic field is formed by three-phase AC coils, so there is a difference in the geometric structure. Since motors and generators generally have reversibility in principle, in the explanations in this specification, we will sometimes compare similarities with motors or provide comparisons with generators. However, the principle is that ``the structure is similar to a generator'' and ``the operating principle is similar to a wound three-phase induction motor.''
This is what we are doing.

When the coil 5 in which this voltage is induced is opened and closed by the switching element 6 as shown in FIG. Due to the magnetic action with the magnetic pole 2 of the permanent magnet, the passive pulley 3 slips slightly more than the drive pulley 1 and rotates in the state shown by symbol A in FIG. These electromagnetic relationships are based on the same principle as a wound three-phase induction motor.

When the switching element 6 is open, no current flows through the coil 5, so no magnetic force is generated, and therefore no torque for driving the passive pulley 3 is transmitted.

When the switching element 6 is turned ON and OFF as shown in FIG. 6 by an electronic control means such as a computer, so-called chopper control, a driving force proportional to the ON time of the switching element 6 is generated in the passive pulley 3. death,
The slip rate is larger than when the circuit is always closed,
It rotates at the speed shown by symbol B in FIG.

When the switching element 6 is turned on and off as shown in FIG. 7 by an electronic control means such as a computer, the slip ratio of the passive pulley 3 further increases.
It rotates at the speed shown by symbol C in FIG.

In this way, by chopper controlling the current induced in the coil 5 attached to the passive pulley 3, as shown in FIG. 8, even if the rotational speed of the drive pulley 1 increases, the computer By setting the chopper control mode to A, B, C or any ratio between them, the rotational speed of the passive pulley 3 can be set to any N1,
It can be set to a value such as N2 or N3.

However, when the rotation speed of the drive pulley 1 is low, the rotation of the driven pulley 3 tends to be too low by the amount of slip, so the pulley ratio of the V-belt 8 is adjusted so that the rotation of the drive pulley 1 is faster than in the past. need to be designed.

The concept of the computer processing flowchart shown in FIG. 9 will be explained. A chopper that detects the engine rotational speed a with a sensor and inputs it to the computer, determines whether the engine is in an acceleration state based on the degree of change in a over time, and reduces power transmission to the compressor only during acceleration. By making it a control pattern,
Reduces the load on the engine. By detecting the cooler temperature or pressure b of the car cooler with a sensor and inputting it to the computer, it is determined whether the cooler temperature is within the normal range, and the chopper control mode is selected so that the temperature is within the appropriate range.

By detecting the vehicle interior temperature c using a sensor and inputting it to the computer, it is determined whether the cooling capacity of the car cooler is higher than the required value, and the chopper control mode is selected so that the cooling capacity is at the appropriate level. . Furthermore, by detecting the rotational speed d of the passive pulley 3 with a sensor and inputting it to the computer, it is determined whether the compressor is rotating at an abnormally high speed that exceeds the design tolerance, and the chopper Select control mode.

[0023]

[Effects of the Invention] As described above, if the variable speed clutch of the present invention is used, even when the engine speed changes significantly depending on the driving condition of the vehicle, the computer can perform appropriate chopper control. As a result, the rotation speed of the compressor can be set to a value corresponding to the required cooling capacity, as indicated by N1, N2, and N3 in FIG. This prevents frost from forming on the cooler due to overcooling, which previously occurred, and also prevents the compressor from turning on and off.
Comfort inhibition caused by F can be prevented.

[0024] When a car is traveling on a highway,
Even if the engine rotates at high speed, the compressor does not rotate beyond a controlled speed, which prevents wasteful energy consumption and improves vehicle drivability. Furthermore, when the vehicle is accelerating, the compressor rotation is controlled to be low only during a very short period of time when the engine rotation is accelerating, so the acceleration performance of the vehicle is improved and driving becomes easier.

[0025] Conventional compressors need to have high-speed rotational strength that can handle the maximum engine speed, but they also need to have a capacity that allows them to provide the necessary cooling capacity at relatively low rotational speeds during normal operation. was there. Therefore, overcapacity compressors were being used. In contrast, with the product of the present invention, there is no need for the compressor to have high-speed rotational power, so it is possible to design a system that uses a relatively small compressor at nearly full rotation at all times, making it small, lightweight, and inexpensive. can.

[0026] Since the various mechanical attachment devices conventionally used to solve the above-mentioned problems are no longer required, the system has the advantage of being simpler, lighter, and less expensive.

In the present invention, since the drive pulley 1 side, which is constantly rotating, is a combination of permanent magnets with a simple structure, the rotational inertia mass can be reduced. Therefore, it has the advantage of reducing the acceleration load on the engine throughout the year.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a variable speed clutch of the present invention.

FIG. 2 is a YY cross-sectional view of FIG. 1.

FIG. 3 is an explanatory diagram of connections between a coil and a switching element.

FIG. 4 is an explanatory diagram of connections between a coil and a switching element.

FIG. 5 is a conceptual diagram of the car cooler system of the present invention.

FIG. 6 is an explanatory diagram of ON/OFF operation of a switching element.

FIG. 7 is an explanatory diagram of ON/OFF operation of a switching element.

FIG. 8 is a graph showing the rotational relationship between the drive pulley and the passive pulley.

FIG. 9 is a flowchart explaining the concept of a computer program for implementing the present invention.

FIG. 10 is a conceptual diagram of a conventional car cooler system.

[Explanation of symbols]

1 Drive pulley 2. Magnetic pole of permanent magnet 3 Passive pulley 4 Electromagnetic core 5 Coil 6 Switching element 7 Automobile engine 8 V-belt 9 Main shaft of compressor 10 Electromagnetic clutch 11 Compressor 12 Compressor body 13 Ball bearing 14 Ball bearing 15 Electrical resistance 16 Diode 17 Groove

Claims (2)

[Claims] 1. A plurality of magnetic poles 2 of permanent magnets are attached to a driving pulley 1, an electromagnetic core 4 is attached to the outer periphery of a passive pulley 3, and a plurality of coils 5 are attached to grooves 17 formed at equal intervals on the outer periphery of the electromagnetic core 4. The variable speed clutch is configured such that the terminals of the coil 5 can be short-circuited by a switching element 6. 2. The driving pulley 1 is driven by an automobile engine 7 via a V-belt 8, and the main shaft 9 of a refrigerant compressor is connected to the passive pulley 3 to construct a car cooler system. By inputting at least one value or all of the values of the cooler temperature or pressure b, the vehicle interior temperature c, and the rotational speed d of the passive pulley 3 into the computer, and opening and closing the switching element 6 according to a preset program. The variable speed clutch according to claim 1, which performs a speed change operation.