JPS6360232B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a refrigerant flow rate control device for a multilobe vane rotary compressor used in automobile air conditioners and the like.

Conventional Structure and Problems Generally, an air conditioner for an automobile is constructed by sequentially connecting a compressor, a condenser, a liquid receiver, an expansion valve, and an evaporator with a refrigerant pipe. The compressor is attached to the engine block and driven by the engine via a belt and an electromagnetic clutch. A feature of such an air conditioner for an automobile is that, since the compressor is driven by an engine, the rotation speed of the compressor varies over a wide range with the engine rotation speed.

Such air conditioners are constructed with a refrigeration cycle that exhibits appropriate cooling capacity at a certain appropriate rotation speed, but in recent years, due to traffic conditions, cooling has gradually become less effective when the engine rotates at low speeds, that is, when driving at low speeds. Ability is becoming more important.

Therefore, during high-speed rotation, due to the thermal balance between the refrigeration capacity of the compressor, the heat dissipation capacity of the radiator, the heat absorption capacity of the heat absorber, etc. in the refrigeration cycle, the discharge pressure of the compressor generally rises above the appropriate value, and Suction pressure tends to decrease. This phenomenon is more pronounced in compressors whose refrigerating capacity increases in direct proportion to the rotational speed.

In such refrigeration cycles, often
During high-speed rotation, the discharge temperature would rise abnormally, causing problems such as deterioration of the refrigerating machine oil and damage to the rubber piping. Furthermore, this may lead to damage such as seizure of the compressor itself, resulting in an extreme loss of reliability. In addition, the power required for the compressor increases significantly, resulting in many problems such as deterioration of vehicle acceleration and driving feeling.

Furthermore, in recent years, fuel efficiency throughout the year has been sought after, and compressors have been required to have power-saving functions to cope with the heat load inside the vehicle.

To solve this problem, a well-known means for room air conditioner compressors is capacity control using the so-called cylinder bypass method, which bypasses the compression-starting gas refrigerant inside the compressor to the suction side.
It has not been put to practical use in vehicle air conditioners due to problems such as reliability. In addition, capacity control using cylinder bypass has the problem of deterioration of compressor efficiency due to occurrence of bypass loss, etc., and a higher efficiency capacity control is desired.

Purpose of the Invention The present invention not only suppresses excessive cooling capacity when the compressor rotates at high speed in a vehicle air conditioner, but also efficiently provides the required amount of cooling capacity to the heat load of the vehicle, regardless of the rotation speed of the compressor. By providing a compressor that achieves high performance, it is possible to prevent an abnormal discharge temperature rise, significantly reduce the required power, and maintain a comfortable vehicle driving feeling.

Structure of the Invention To achieve this object, the refrigerant flow rate control device of the present invention includes an electromagnet at a location corresponding to at least one compression chamber of a side plate that closes a cylinder from both sides in a multilobe vane rotary compressor. The required number of electromagnets are arranged and energized as needed.

With this configuration, electromagnetic force is used to prevent the vanes from ejecting from the rotor, and work is done only in the compression chamber that is not energized, while in the energized compression chamber, since the vanes are not protruding, no damage is caused. This provides an efficient refrigerant flow rate control function without any work.

DESCRIPTION OF EMBODIMENTS The present invention will be described below with reference to the accompanying drawings showing one embodiment thereof.

In FIG. 1, a rotor 1 is supported by bearings provided on a front plate 3 and a rear plate 4 so as to be concentric with a cylindrical cylinder 2. Moreover, the inner wall of the cylinder 2 is elliptical, and the rotor 1 and two adjacent parts 5, 6
It has two left and right compression chambers 5a and 6a. The rotor 1 has a plurality of radial slits 7, and vanes 8 are slidably disposed inside the slits 7. An electromagnet 9 is provided on the rear side plate 4 and is energized from outside the compressor. The rotor 1 is made of a non-magnetic material, whereas the vanes 8 are made of a magnetic material. In such a configuration, when the electromagnet 9 is energized, the vane 8 is prevented from ejecting from the rotor 1 by magnetic force.

Next, the behavior of the vane 8 will be explained with reference to FIG.

The electromagnet 9 is connected to one of the two compression chambers 5.
It is provided to control the vane behavior at point a. When the vane 8 passes the proximal part 5, the vane 8 is moved around the rotor 1 by the magnetic force of the energized electromagnet 9.
is prevented from protruding from the slit 7, and the suction hole 1
The work of compressing the incoming gas refrigerant from 0 cannot be done. Then, after passing the next proximal part 6, the vane 8
Since it becomes possible to slide, normal compression work is performed in the next compression chamber 6a.

In this way, by energizing the electromagnet 9 as necessary, the compressor becomes a variable capacity type.
Furthermore, there is no loss seen in conventional bypass systems, resulting in an efficient refrigerant flow rate control device.

Effects of the Invention As explained above, in the refrigerant flow rate control device for a multi-lobe type vane rotary compressor of the present invention, a portion corresponding to at least one compression chamber of the front side plate and rear side plate that closes the cylinder from both sides. , an electromagnet is arranged, and the vane is made of a magnetic material, and the behavior of the vane is controlled by energizing the electromagnet when necessary, such as when the compressor is rotating at high speed or when the heat load inside the vehicle is low. Since the compressor can have variable capacity, efficient refrigerant flow rate control can be performed. As a result, the power required for the compressor can be significantly reduced, and an abnormal rise in discharge temperature when the compressor rotates at high speed can be prevented, and many other effects can be obtained.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a multi-lobe vane rotary compressor having a refrigerant flow rate control device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line AA in FIG. 1. 1... Rotor, 2... Cylinder, 3... Front side plate (side plate), 4... Rear side plate (side plate), 5a, 6a... Compression chamber,
7...Slit, 8...Vane (movable vane), 9...
electromagnet.

Claims (1)

[Claims] 1 A rotor having a plurality of movable vanes is supported concentrically within a cylinder having a cylindrical inner wall so that each movable vane is always close to the cylinder inner wall to form a plurality of compression chambers, and further the cylinder is A refrigerant flow rate control device for a multilobe vane rotary compressor, in which an electromagnet is arranged at a location corresponding to at least one compression chamber of a side plate that is closed from both sides, and each of the movable vanes is made of a magnetic material.