JPS6325195B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a vane rotary compressor, and particularly to an oil supply device for a vane rotary compressor driven by a drive source whose rotational speed changes, such as an automobile engine.

Prior Art As is well known, vane rotary compressors have a structure in which high-pressure lubricating oil is constantly applied to the bottom of the vane so that as the rotor rotates, the vane rotates and slides with its tip in contact with the inner wall of the cylinder. is often used. Generally speaking, the means to achieve this are the forced lubrication system, in which lubrication is forcibly supplied using a trochoid pump installed on the drive shaft of the vane rotary compressor, and the discharge pressure of the compressed fluid compressed by the vane rotary compressor. Differential pressure lubrication is widely used.

For example, Japanese Patent Publication No. 49-26522 describes a differential pressure oil supply type rotary compressor. Here, under the pressure of high-pressure gas, the lubricating oil in the oil reservoir is guided to the bottom of the vane and exerts pressure on the vane, simultaneously lubricating the sliding parts of the vane and the sliding parts between the rotor and the front and rear walls. It performs a sealing action to prevent pressure drop due to leakage at the bottom of the vane.

Further, Japanese Utility Model Publication No. 54-8009 discloses a configuration in which, when the compressor is in operation, an electromagnetic coil is energized, a valve device is opened, and oil is supplied by differential pressure as in the prior art example.

Problems to be Solved by the Invention However, in the configuration in which oil is supplied using differential pressure as described above, even during high-speed operation of the compressor, high-pressure fluid acts on the bottom of the vane in the same way as during low-speed operation. is pressed against the inner wall of the cylinder due to the increased fluid pressure due to high-speed rotation and the significantly increased centrifugal force of the vanes, which increases the frictional force between the tips of the vanes and the inner wall of the cylinder, increasing the power required for the compressor. This has the problem of causing abnormal wear on the vane tip and the inner wall of the cylinder, resulting in poor durability.

Furthermore, when the compressor is operated at high speed, the flow rate of the high-pressure refrigerant gas discharged from the compression section increases, which deteriorates the oil separation rate in the high-pressure refrigerant gas by the oil separator, and increases the speed of vanes appearing and retracting. An increase in the amount of lubricating oil supplied due to an increase in the pressure difference between the high and low pressures of the compressor causes a decrease in the lubricating oil in the oil sump, and as a result, the proportion of lubricating oil in the high-pressure fluid acting on the bottom of the vane decreases significantly, causing the aforementioned vane The sealing performance of the sliding parts of the rotor and the rotor will deteriorate, and the high-pressure fluid supplied to the bottom of the vane will easily leak into the working chamber through the gap between the vane and the vane groove and the gap between the rotor and the side wall. Become. Therefore, the high-pressure fluid that flows into the working chamber during the suction stroke is at a high temperature, causing a decrease in the volumetric efficiency of the compressor, that is, the cooling capacity, and the high-pressure fluid that flows into the working chamber during the compression stroke This has the problem that the power required for the compressor increases due to the increase in pressure within the working chamber.

In view of the above-mentioned conventional problems, the present invention aims to reduce the required power of the compressor and improve its durability by reducing the frictional force between the vanes and the inner wall of the cylinder when the compressor rotates at high speed. An object of the present invention is to provide an oil supply device that can improve the cooling capacity of a compressor and reduce the required power by reducing leakage of high-pressure fluid into a working chamber.

Means for Solving the Problems In order to solve the above problems, the vane rotary compressor oil supply device of the present invention has a suction hole 50 and a discharge hole 4.
7 and this cylinder 41
A part of the circumferential wall of the cylinder 41
A rotor 44 slidingly contacts between the suction hole 50 and the discharge hole 47 on the inner surface, and side plates 43a and 4 that support the rotor 44 and close both end surfaces of the cylinder 41.
3b, and an oil supply chamber case 5 attached to the one side plate 43b and whose interior communicates with the discharge hole 47.
1 constitutes a compressor main body, and the rotor 44
The slot 45 provided in the
A vane 46 is provided that is inserted into the interior so as to be freely retractable and whose tip is always in contact with the inner surface of the cylinder.Furthermore, high pressure from the oil supply chamber case 51 is applied to the rear end of the vane 46 on the one side plate 43b, so that the vane 46 is In a vane rotary compressor provided with a protruding lubricating oil supply passage 56, one end is opened to the lower part 54 of the case 51 of the oil supply chamber on one side of the compressor main body, and the other end is used for lubricating the compressor main body. Oil supply passage 56
A valve body 55 having oil supply passages 57, 58, and 62 passing through the valve body 55 is provided, and the oil supply passages 57, 58, and
A control mechanism for controlling the amount of lubricating oil supplied to the lubricating oil supply passage 56 by changing the opening area of 58 and 62 in inverse proportion to the rotation speed is provided, and as a control mechanism for controlling the amount of lubricating oil, A control circuit that detects the rotational speed of the vane rotary compressor and reduces the output voltage in response to the increase in rotational speed, an electromagnetic coil 39 to which the output voltage of this control circuit is energized, and an excitation force of the electromagnetic coil 39. a sliding member that is attracted and moves; a spring 61 that balances the attractive force of the electromagnetic coil 39 and defines a moving distance of the sliding member;
It is constructed of a valve body whose opening degree changes depending on the moving distance of the sliding member.

Effect: With the above configuration, the opening area of the oil supply passage decreases as the rotational speed of the compressor increases, so the pressure acting on the bottom of the vane decreases, and the pressing force of the vane against the inner wall of the cylinder decreases. do. As a result, the frictional force of the vanes is reduced, reducing the compressor's required power and improving its durability.Furthermore, the leakage of high-pressure fluid into the working chamber can be reduced, improving the compressor's cooling capacity and reducing the required power. reduction is possible.

Embodiment Hereinafter, the present invention will be described with reference to the accompanying drawings showing one embodiment of the invention.

First, the structure of a vane rotary compressor will be explained with reference to FIGS. 1 and 2.

In the figure, 41 is a cylinder having a cylindrical inner wall, the center of which is eccentrically located with respect to a drive shaft 42 that transmits power from the outside. Both ends of the cylinder 41 are closed by a front plate 43a and a rear plate 43b, each of which has a bearing that rotatably supports the drive shaft 42.
3a and the rear side plate 43b are connected and fixed so that they do not rotate relative to each other. A rotor 44 integrally formed with the drive shaft 42 is disposed in a space formed by the inner wall front plate 43a and rear side plate 43b of the cylinder 41, with its movement in the axial direction being restricted. has been done. Reference numeral 45 designates a plurality of vane slots provided in the rotor 44, which are connected to the drive shaft 42.
The opening is parallel to the axis of the rotor 44 and opens on the outer peripheral surface of the rotor 44. 46 is a plate-shaped vane inserted into the vane slot 8 so as to be freely retractable. A discharge hole 47 is provided at a position on the high pressure side of the cylinder 41 and opens into a high pressure gas chamber 48, and a discharge valve 49 is provided in the discharge hole 47. 50 is a suction hole provided in the rear side plate 43b.

Reference numeral 51 denotes an oil supply chamber case, which communicates with the high pressure gas chamber 48 through a passage 52, and has a compressed fluid discharge port 5 at the top.
3, and an oil reservoir portion 54 is provided below. 5
5 is a valve body fixed to the rear side plate 43b in the oil supply chamber case 51;
a lubricating oil communication passage 5 that communicates with a lubricating oil supply passage 56 that is provided in b and communicates with the vane slot 45;
It has 7. 58 has one end connected to the lubricating oil communication passage 5
7 and the other end is connected to the oil reservoir portion 54 of the oil supply chamber 51.
This is a fuel supply pipe that opens to the 59 is a check valve interposed between the lubricating oil communication passage 57 and the oil supply pipe 58;
It is composed of a first sliding chamber 60 and a ball valve 63 that is slidably inserted into the first sliding chamber 60 and is pressed against the oil supply port 62 of the lubricating oil communication passage 57 by a spring 61. There is. 64 is a second sliding chamber provided in the valve body 55 on the side facing the spring 61 with the ball valve 63 of the check valve 59 therebetween;
An electromagnetic coil 39, which is excited by a control circuit to be described later, is fixed inside, and the rod 6 attached to the front part is attracted by the excitation of this electromagnetic coil 39.
5, the ball valve 6 of the check valve 59
A sliding member 66 is slidably inserted into the lubricating oil communication passage 57 to move and retract it from the oil supply port 62 of the lubricating oil communication passage 57 by sliding the lubricant 3 against the biasing force of the spring 61.

Here, the compressor having the above configuration has a drive shaft 4
An electromagnetic clutch (not shown) having a well-known structure is attached to the electromagnetic clutch 2, and power from an automobile engine or the like is transmitted through this electromagnetic clutch.

Next, a control circuit for controlling the electromagnetic coil 39 according to the rotational speed of the vane rotary compressor will be explained with reference to FIG.

In the figure, 1 is a (positive) potential supply section, one is connected to the output of the temperature control device (not shown) of the refrigeration cycle of which the vane rotary compressor constitutes a part, and the other is the electromagnetic coil control section. 2 and an electromagnetic clutch 3 which transmits power from a drive source such as an automobile engine to a drive shaft 42 of the vane rotary compressor. The other end of the electromagnetic clutch 3 is connected to ground 4. Reference numeral 5 denotes a diode for absorbing the back electromotive force generated by the electromagnetic clutch 3. Reference numeral 1a denotes an input section of the electromagnetic coil control section 2, which is connected to the (minus) potential side of an ignition coil (not shown) of an automobile engine. The electromagnetic coil control section 2 includes a waveform shaping circuit composed of a resistor 6, capacitors 7 and 8, resistors 9, 10, 11, 12, 13, 14, a capacitor 15, diodes 16 and 17, and a transistor 1.
It consists of a monostable multi-circuit consisting of 8 and 19, and an FV converter 20. This FV converter 20 is connected to the output of the monostable multi-circuit, the potential supply section, the ground 4, and the electromagnetic coil 39, respectively. The diode 22 is for absorbing the back electromotive force of the electromagnetic coil 39.

Next, the operation of the vane rotary compressor having the above configuration will be explained.

First, when power is transmitted from a drive source such as an engine through the electromagnetic clutch 3 and the drive shaft 42 rotates clockwise in FIG. 50
It flows into the compression chamber inside the cylinder 41. The high-pressure refrigerant compressed as the rotor 44 rotates flows from the discharge hole 47 through the high-pressure gas chamber 48 into the oil supply chamber case 51, where it is separated from the lubricating oil and exits from the compressed fluid outlet 53. It is sent to a refrigeration cycle condenser (not shown).

The lubricating oil separated from the high-pressure refrigerant is stored in an oil reservoir 54 below the oil supply chamber case 51, and
The rotor 44 and the front plate 43 are then pressed.
A part of the air flows into the working chamber while sealing the gap between the cylinder a and the rear side plate 43b. At this time, the valve body 55 performs the following operation.

That is, when the electromagnetic coil 39 is excited in the oil supply passage consisting of the oil supply pipe 58, the first sliding chamber 60, the oil supply port 62, and the lubricant communication passage 57, the sliding member 66 is attracted by the excitation. The ball valve 63 of the check valve 59 is refilled in the lubricating oil communication passage 57 until the front rod 65 resists the spring 61 and reaches a position where the compressive force of the spring 61 and the suction force of the sliding member 66 are balanced. It is moved from the mouth 62. As a result, a suitable opening area is secured between the ball valve element 63 and the valve seat surface of the oil filler port 62 due to the balanced position of the rod 65 and the spring 61.

Therefore, the lubricating oil in the oil reservoir 54 below the oil supply chamber 51 is supplied to the back of the vane 46 by the differential pressure between the oil supply chamber 51 and the vane slot 45, depending on the size of the opening area.

On the other hand, in the control circuit configured as described above,
To explain the terminal voltage of the electromagnetic coil 39 due to changes in the rotational speed of the vane rotary compressor, that is, the rotation speed of the engine, the higher the engine rotational speed, the higher the frequency of the output pulse of the monostable multi-circuit becomes. As a result, the terminal voltage of the electromagnetic coil 39 becomes low. Therefore, the balanced position of the rod 65 and the spring 61 moves upward in FIG. 1, and the opening area between the ball valve element 63 and the valve seat surface of the oil filler port 62 becomes smaller. As a result, the amount of lubricating oil supplied to press the vane 46 against the inner wall of the cylinder 41 decreases as the rotational speed of the vane rotary compressor increases. The pressing force caused by this lubricating oil acts effectively on the vanes 46 together with the centrifugal force which increases as the rotational speed of the vane rotary compressor increases, and the pressing force of the vanes 46 against the inner wall of the cylinder 41 is always maintained at an appropriate level.

Conversely, when the engine speed is low, the terminal voltage of the electromagnetic coil 39 becomes high.
The balanced position of the rod 65 and the spring 61 moves downward in FIG.
The opening area between the vane 46 and the valve seat surface is increased, and the amount of lubricating oil for pressing the vane 46 against the inner wall of the cylinder 41 can be secured, allowing operation without any problems.

Note that FIG. 4 shows the relationship between the engine rotation speed and the output of the FV converter 20 (terminal voltage of the electromagnetic coil 39). That is, the opening areas of the ball valve 63 and the oil filler port 62 are always controlled in accordance with the engine rotational speed using the characteristics shown in the figure, and the optimal amount of lubricating oil to be pressed into the vane 46 at that time is controlled.

As described above, according to this embodiment, the terminal voltage of the oil supply passage for applying pressure to the vane 46 is controlled to decrease as the rotational speed of the vane rotary compressor increases. Electromagnetic coil 39
, a sliding member 66 that is attracted and moved by the excitation of the electromagnetic coil 39 and moves the ball valve 63 from the oil supply port 62 of the lubricating oil communication passage 57 , and the sliding member 66 that changes depending on the terminal voltage of the electromagnetic coil 39 . By disposing a spring 61 that balances the suction force of the member 6 and regulates the moving distance of the sliding member 66, the higher the rotational speed of the vane rotary compressor, the more lubrication is supplied to the back of the vane 46. Control is possible to reduce the oil and thereby reduce the pressing force of the vanes 46 against the inner wall of the cylinder 41, and the pressing force of the vanes 46 against the inner wall of the cylinder 41 can always be maintained at an appropriate level. This reduces friction and wear between the vane 46 and the inner wall of the cylinder 41, and also reduces the flow of high-pressure fluid into the working chamber from the oil supply chamber case 51, improving the cooling capacity of the compressor and reducing the required power. can. Furthermore, when the vane rotary compressor is stopped, the electromagnetic coil 36 is not excited and the oil supply passage is cut off, so the lubricating oil in the oil reservoir 54 below the oil supply chamber 51 flows into the compression chamber, causing the vane to rotate. It is also possible to eliminate problems that interfere with restarting the compressor.

It should be noted that FIG. 5 shows another embodiment of the present invention, and in this figure, the same parts as those in the above embodiment are given the same numbers and the description thereof will be omitted.

In this other embodiment, the sliding member 66 is configured to open and close the oil supply port 62 of the lubricating oil communication passage 57, and when combined with the control circuit shown in FIG. 3, the same effects as in the above embodiment can be obtained. It is something.

Effects of the Invention As described above, the vane rotary compressor oil supply device of the present invention reduces the opening area of the oil supply passage as the compressor rotation speed increases. Since the opening area is reduced, the pressure acting on the bottom of the vane during high speed rotation is reduced. This reduces the pressing force of the vanes against the cylinder inner wall, reducing excessive friction and wear of the vanes during high-speed rotation, thereby reducing the power required for the compressor and improving durability. Furthermore, since the inflow of high-pressure fluid from the oil supply chamber case into the working chamber can be reduced, the cooling capacity of the compressor can be improved and the required power can be reduced.

Furthermore, when the oil supply passage is restricted, a large amount of lubricating oil accumulates in the oil supply chamber case, and the lubricating oil ratio in the refrigerant circulating in the refrigeration cycle decreases, which also has the effect of improving cooling performance.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a vane rotary compressor equipped with a lubricating device according to an embodiment of the present invention, Fig. 2 is a sectional view taken along the line X--X of Fig. 1, and Fig. 3 is a control operation of the lubricating device. Fig. 4 is a characteristic diagram showing the relationship between the rotation speed and the electromagnetic coil terminal voltage by the lubricating device, and Fig. 5 is an enlarged cross-section of the main part of the lubricating device for a vane rotary compressor in an embodiment of the present invention. It is a diagram. 39... Electromagnetic coil, 41... Cylinder, 43a,
43b... Side plate, 44... Rotor, 45... Vane slot, 46... Vane, 47... Discharge hole, 50... Suction hole, 51... Oil supply chamber case, 54... Oil reservoir portion, 55
...Valve body, 56...Lubricating oil supply passage, 61...Spring, 66...Sliding member.

Claims (1)

[Claims] 1. A cylinder 41 equipped with a suction hole 50 and a discharge hole 47, a rotor 44 disposed within the cylinder 41 and having a part of its peripheral wall always in sliding contact between the suction hole 50 and the discharge hole 47 on the inner surface of the cylinder 41; Side plates 43a and 43b support the rotor 44 and close both end faces of the cylinder 41, and the discharge hole 47 is attached to the one side plate 43b and has the inside thereof covered with the discharge hole 47.
A compressor main body is constituted by an oil supply chamber case 51 communicating with the rotor 44, a slot 45 provided in the rotor 44, and a vane 46 which is inserted into the slot 45 so as to be freely retractable and whose tip is always in contact with the inner surface of the cylinder.
A vane rotary compressor further includes a lubricating oil supply passage 56 on the one side plate 43b that applies high pressure from the oil supply chamber case 51 to the rear end of the vane 46 to cause the vane 46 to protrude,
An oil supply passage 5 is provided on one side of the compressor body, and one end thereof opens into the lower portion 54 of the case 51 of the oil supply chamber, and the other end communicates with the lubricant supply passage 56 of the compressor body.
A valve body 55 having 7, 58, 62 is provided,
In this valve body 55, the opening areas of the oil supply passages 57, 58, 62 are changed in inverse proportion to the rotation speed according to the rotation speed of the rotor 44, and the amount of lubricant supplied to the lubricant oil supply passage 56 is controlled. The control mechanism for controlling the amount of lubricating oil includes a control circuit that detects the rotational speed of the vane rotary compressor and reduces the output voltage in response to an increase in the rotational speed of the vane rotary compressor, and the output of this control circuit. An electromagnetic coil 39 to which a voltage is applied, a sliding member that is attracted and moved by the excitation force of the electromagnetic coil 39, and a spring 61 that balances the attractive force of the electromagnetic coil 39 and defines the moving distance of the sliding member. and a vane rotary compressor oil supply device comprising a valve body whose opening degree changes depending on the moving distance of the sliding member.