JPS6325197B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates 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, this is accomplished by using a forced lubrication system, which uses a trochoid pump installed on the drive shaft of a rotary vane compressor, and by using the discharge pressure of the compressed fluid compressed by the rotary vane compressor. A differential pressure lubrication system in which lubrication is carried out is widely used.

However, unlike these conventional oil supply devices, applying high-pressure lubricating oil to the bottom of the vane in the same manner as during low-speed operation even when the vane rotary compressor is operating at high speeds is coupled with a significantly increased centrifugal force acting on the vanes. The problem is that the vanes are pushed into excessive contact with the cylinder inner wall, which increases the frictional force between the vane tip and the cylinder inner wall, increasing the power required for the compressor, and further causing abnormal wear of the vane tip and the cylinder inner wall, resulting in poor durability. There is.

In order to solve this problem, for example,
As shown in No. 7988, a structure has been proposed in which an oil feed groove is formed in the rotor and the lubricating oil acting on the bottom of the vane flows into the low pressure side by the pumping action of the groove as the rotor rotates. Thereby, the contact pressure of the vane obtained by the pressure of lubricating oil acting on the back of the vane and the centrifugal force can be controlled without being affected by the rotation of the rotor.

Problems to be Solved by the Invention However, in the above configuration, the lubricating oil is released to the low pressure side in order to reduce the pressure at the bottom of the vane, resulting in high pressure lubricating oil and dissolved therein. The refrigerant will return to the low pressure side. Therefore, as the pressure at the bottom of the vane decreases, the flow of fluid from the high-pressure side to the low-pressure side increases, and refrigerant cannot be sucked in from the outside of the compressor.As a result, the cooling capacity of the compressor decreases. There was a problem in that the performance decreased.

In view of the above-mentioned problems, the present invention maintains the pressing force of the vanes against the inner wall of the cylinder at all times without being affected by the rotational speed of the compressor and without reducing the cooling capacity of the compressor. To provide an oil supply device that can reduce the frictional force between the vanes and the inner wall of the cylinder to reduce the power required for the compressor, and further reduce the wear of the vanes and the inner wall of the cylinder to improve the durability of the compressor.

Means for Solving the Problems In order to solve the above problems, the oil supply device for a vane rotary compressor of the present invention includes an oil supply passage that communicates the bottom of the vane with an oil reservoir below the high-pressure oil supply chamber case; A valve body that opens and closes this oil supply passage, an electromagnetic coil that moves the valve body by this energization and switches the open/closed state, and an electromagnetic coil that opens and closes the oil supply passage per unit time as the compressor rotation speed increases. The coil is equipped with a control device that energizes the coil intermittently.

Effect The present invention has the above-described configuration, so that when the compression rotational speed increases, the amount of lubricating oil supplied from the oil reservoir below the oil supply chamber case to the bottom of the vane is reduced, and the opening time of the oil supply passage per unit time is reduced. therefore, the pressure acting on the bottom of the vane decreases. As a result, the pressing force of the vanes against the cylinder inner wall can be reduced without reducing the cooling capacity of the compressor, and the frictional force and wear of the vanes can be reduced.

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. an inner wall of the cylinder 41;
A rotor 44 integrally formed with the drive shaft 42 is disposed in a space formed by the front side plate 43a and the rear side plate 43b in a state where movement in the axial direction is restricted. 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 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 into 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 the lubricant 3 against the biasing force of the spring 61 and move it away from the oil supply port 62 of the lubricating oil communication passage 57.

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 designates 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, 15, a capacitor 16, diodes 17 and 18, and transistors 19 and 20. Structured monostable multi-circuit, resistors 21, 22, 23, 24, capacitors 25, 2
6, 27, an integrating circuit composed of a transistor 28, an astable multi-circuit 32, and a resistor 29, 3
0 and a transistor 31. The astable multi-circuit 32 is connected to the integrating circuit potential supply section 1, the ground 4, and the resistor 29, and the base of the transistor 31 is connected between the resistors 29 and 30. The emitter of the transistor 31 is connected to the ground 4, and the collector is connected to the electromagnetic coil 3.
Connected to 9. The diode 33 is for absorbing the back electromotive force of the magnetic transmission 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 the condenser (not shown) of the refrigeration cycle.

The lubricating oil separated from the high-pressure refrigerant is stored in an oil reservoir 54 below the oil supply chamber case 51, and
It is subjected to pressure. At this time, the valve body 55 performs the following operation.

That is, when the electromagnetic coil 39 is excited, the sliding member 66 is attracted to 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. Then, the rod 65 at the front part opens the ball valve 63 of the check valve 59 to move and retreat from the oil supply port 62 of the lubricating oil communication passage 57 against the biasing force of the spring 61. Conversely, when the electromagnetic coil 39 is not energized, the ball valve 63 of the check valve 59 is pressed against the oil supply port 62 of the lubricating oil communication passage 57 due to the differential pressure between the spring 61 and the ball valve 63, and is therefore shut off. be done.

Therefore, the lubricating oil in the oil reservoir 54 below the oil supply chamber case 51 is transferred to the vane 46 by the differential pressure between the oil supply chamber 51 and the vane slot 45 only when the oil supply passage is opened, that is, when the electromagnetic coil 39 is energized. is supplied to the back of the body.

On the other hand, in the control circuit configured as described above,
When the rotational speed of the vane rotary compressor is low, that is, when the engine rotational speed is low, the potential at the input (point A) of the astable multicircuit 32 is high, and the output (point B) has a constant duty pulse width. Become.
Conversely, when the rotational speed of the vane rotary compressor increases, that is, when the rotational speed of the engine increases, the potential at point A becomes lower and the duty of the pulse at point B becomes smaller.

That is, the higher the speed, the shorter the conduction time of the transistor 31, and therefore the shorter the excitation time of the electromagnetic coil 39. 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, and the pressing force of the vane 46 also decreases. The pressing force caused by this lubricating oil acts effectively on the vanes 46 together with the centrifugal force that increases as the rotational speed of the vane rotary compressor increases, making it possible to always maintain an appropriate pressing force of the vanes 46 against the inner wall of the cylinder 41. can.

As described above, according to this embodiment, the excitation time per unit time is reduced in the oil supply passage for applying pressure to the vane 46 as the rotational speed of the vane rotary compressor increases. an electromagnetic coil 39 that is controlled by the electromagnetic coil 39; a sliding member 66 that is moved by the excitation of the electromagnetic coil 39 to move the ball valve 63 from the oil supply port 62 of the lubricating oil communication passage 57; By disposing a spring 61 that presses the ball valve 63 against the oil supply port 62 of the lubricating oil communication passage 57, the higher the rotational speed of the vane rotary compressor, the more the lubricating oil supplied to the back of the vane 46 is reduced. As a result, the pressure of the lubricating oil acting on the bottom of the vane 46 can be reduced, and the pressing force of the vane 46 against the inner wall of the cylinder 41 can be maintained at an appropriate level at all times. Therefore, without reducing the cooling capacity of the compressor, the frictional force between the vanes 46 and the inner wall of the cylinder 41 can be reduced, reducing the required power accordingly.Furthermore, wear between the vanes 46 and the inner wall of the cylinder 41 can be reduced, improving durability. can be realized. Furthermore, when the vane rotary compressor is stopped, the electromagnetic coil 39 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 case 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. 4 shows another embodiment of the present invention, and in this figure, the same parts as in the above-mentioned embodiment are given the same reference numerals, and the explanation 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, but when combined with the control circuit shown in FIG. 3, the same effect as in the above embodiment can be achieved. It is clear that the effects can be obtained.

Effects of the Invention As described above, the oil supply device for a vane rotary compressor according to the present invention includes an oil supply passage that communicates between the bottom of the vane and the oil reservoir below the oil supply chamber case, a valve body that opens and closes this oil supply passage, and a valve body that opens and closes the oil supply passage. An electromagnetic coil that moves the valve body by excitation to switch the open/close state, and a control device that intermittently energizes the electromagnetic coil so that the opening time of the oil supply passage per unit time is shortened as the rotational speed of the compressor increases. When the compressor operates at high speed, the amount of lubricating oil supplied to the vane slot is reduced, effectively reducing the pressure of lubricating oil acting on the bottom of the vane, so that the pressing force of the vane against the inner wall of the cylinder is always maintained at an appropriate level. Therefore, the frictional force between the vanes and the inner wall of the cylinder can be reduced without reducing the cooling capacity of the compressor, and the power required for the compressor can be reduced by that amount, and wear of the vanes and the inner wall of the cylinder can be reduced. The durability of the machine can be improved, and by controlling the opening time of the oil supply passage within a unit time as the rotation speed of the compressor changes, the amount of lubricating oil supplied can be controlled without affecting the pressure difference inside the compressor. This allows the lubricating oil to be properly controlled without being affected.

[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 of the lubricating device. The control circuit diagram, FIG. 4, is an enlarged sectional view of a main part of an oil supply system for a vane rotary compressor in another embodiment of the present invention. 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 part, 55
... Valve body, 56 ... Lubricating oil supply passage, 63
...Ball bento.

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 surfaces 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,
A valve body 55 disposed within the oil supply case 51 is provided on one side of the compressor body, and within the valve body 55, one end communicates with the lubricating oil supply passage 56 and the other end communicates with the oil supply chamber case 51. Lower oil sump 5
Further, the valve body 55 is provided with an electromagnetic coil 39 and a valve body 63 that opens and closes the oil supply passages 57 and 58 by energizing and de-energizing the electromagnetic coil 39. A control device is provided to intermittently energize the electromagnetic coil 39, and this control device is combined with a reversing device that alternately outputs voltage to the electromagnetic coil 39 and stops outputting it, and a reversing device that alternately outputs voltage to the electromagnetic coil 39 and stops outputting it, and as the number of rotations of the rotor 44 increases. A lubricating device for a vane rotary compressor comprising a ratio variable means that shortens the voltage output time per unit time in the reversing means and lengthens the output stop time.