JPS6347677Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a gas compressor used in car coolers and the like.

Gas compressors used for air conditioning in ordinary passenger cars, etc.
It is usually installed in parallel with an automobile engine, driven by a V-belt from the engine's crankshaft pulley, and connected to the drive side by an electromagnetic clutch mounted on the compressor side.

Therefore, the capacity of the gas compressor increases almost in proportion to the rotational speed of the engine, but conversely, if you run at high speed for a long time, the gas compressor will increase in speed. Because it is driven by a rotary gas compressor, it causes the interior of the vehicle to become overcooled, and the power consumption also increases in proportion to this, and the temperature of the discharged gas increases.Especially in rotary gas compressors. This tendency is remarkable.

In other words, this type of compressor does not require a suction valve and has little residual compressed gas, so it has high volumetric efficiency during high speed rotation.

In order to prevent the above-mentioned overcooling, the electromagnetic clutch is turned on and off to turn on the gas compressor based on the output of a temperature sensor installed in the evaporator, for example. Some devices are configured to control off.

However, with this configuration, problems arise, such as frequent engagement and engagement of the electromagnetic clutch, which causes significant wear and tear on the clutch, and also increases engine load fluctuations.

In addition, if a gas compressor with a small cooling capacity is used to prevent overcooling at high speeds, the cooling capacity will be insufficient at low speeds, and the interior of the vehicle will not be properly cooled. A problem arises.

This idea was created in view of the conventional problems mentioned above, and its purpose is to automatically increase the work capacity and power consumption in the high-speed rotation drive range by simply adding a simple configuration to the gas compressor. The objective is to suppress the temperature of the discharged gas and prevent the temperature of the discharged gas from rising.

In order to achieve the above objective, this invention provides a cylinder with a sub-intake port that is shifted to the lag side in the rotational direction of the rotor with respect to the main intake port whose opening position is set according to the maximum confinement volume of the compression work chamber. In addition, main and auxiliary flow passages are formed through the cylinder and communicate with each intake port and also with each other, and a spool and a spring that biases the spool in one direction are provided in the main flow passage. The main intake port is inserted through the cylinder to form a throttle valve mechanism that operates according to the flow rate of gas sucked into the cylinder, and as the gas flow rate increases, the opening degree of the main intake port becomes smaller. Features.

That is, in the present invention, by controlling the working chamber volume in the cylinder to become smaller as the speed increases, the amount of discharged gas is reduced, and the cooling capacity and driving power are reduced. This is intended to lower the discharge gas temperature.

Hereinafter, one embodiment of this invention will be described in detail using the drawings.

1 and 2 show a rotary gas compressor to which this invention is applied.

This gas compressor includes a compressor body 2 housed inside a cylindrical casing 1. The compressor main body 2 has a cylinder 3 having a circular cylindrical inner periphery, and a front side block 4 and a rear side block 5 attached to both sides of the cylinder 3, and a cylinder interior having a circular cylindrical shape formed by these. A solid cylindrical rotor 8, which is integral with the rotor shaft 6 and has five vanes 7 attached to its periphery, is horizontally suspended so as to be freely rotatable.

The rotor shaft 6 passes through the front side block 4 and the tip of the casing 1, and is connected to the crankshaft pulley of the engine via an electromagnetic clutch (not shown).
When the rotor 8 is rotationally driven in the direction of arrow A, low-pressure gas is introduced from the intake port provided at the front of the casing 1 and flows into the cylinder 3 through the circulation hole 9 formed in the front side block 4. The air is drawn into the cylinder chamber through a flow path and an intake port, which will be described later, and is compressed.

Further, the high pressure gas compressed in the cylinder chamber is discharged from the discharge port 10 and the check reed valve 11 through the gap between the outer periphery of the cylinder 3 and the inner periphery of the casing 1. It is discharged to the outside through the hole 12 from a discharge port formed at the rear of the casing 2 .

Next, the configuration of the above-mentioned flow passage and intake port, which are the main parts of this invention, will be explained in detail.

The flow passage is composed of a pair of main flow passages 20 formed through the cylinder 3 in the axial direction, and a small-diameter auxiliary flow passage 21 formed through the main flow passage 20 in contact with each main flow passage 20, and has a daruma hole shape as a whole. It is in contact with the communication hole 9 formed in the front side block 4.

The main flow passage 20 communicates with a pair of main intake ports 22 passing through the cylinder 3 in the radial direction, and the subflow passage 21 communicates with three sub intake ports 23 passing through the cylinder 3 in the radial direction. ing.

Furthermore, a spool 24 and a spring 25 that urges the spool 24 toward the protruding side are fitted into each main flow passage 20, and these constitute a throttle valve mechanism that operates according to the gas flow rate sucked into the cylinder chamber. ing.

Here, the main intake port 22 is opened at a position where the confined volume in the cylinder chamber surrounded by each vane 7 is at its maximum value, and the auxiliary intake port 23 is opened at a position where the rotation of the rotor 8 starts from this position. It is opened at the lag side position.

For example, in this embodiment, five vanes are used and the cylinder chamber is divided into five parts, so that each vane is formed at a position offset by about 54 degrees from the short axis center of the cylinder chamber toward the advancing side in the rotational direction of the rotor 8. Furthermore, the sub-intake port 23 is opened at a position deviated by 20 to 30 degrees to the lag side.

Therefore, in this example, the main intake port 22
Assuming that the maximum trapped volume by the pair of vanes 7 passing through the sub-intake port 22 is 100%, the trapped volume by the vanes 7 passing through the sub-intake port 22 is approximately 17% of this.
It will be somewhat small.

As shown in FIGS. 3a and 3b, the spool 24
is restricted from protruding by the inner wall of the front side block 4, and at this position, the opening degree of the main intake port 22 (hereinafter referred to as valve opening degree)
is the maximum. Further, this spool 24 is pushed in the direction of arrow B by the pressure of the gas that enters through the communication hole 9 and is sucked into the cylinder chamber.
The force that presses the spool 24 in the direction of arrow B is due to the large rotational speed of the rotor 8, the large amount of gas sucked into the cylinder chamber per unit time, and the large flow rate of gas flowing into each flow passage 20, 21. The valve opening degree of the main intake port 22 decreases.

Then, as shown in FIG. 3a, the spool 24
When the valve is located on the inner wall of the front side block 4 due to the spring pressure of the spring 25, the above-mentioned valve opening is the largest, and the gas introduced from the circulation hole 9 flows from the sub-flow passage 21 to the sub-intake port 23 and the main intake. It is distributed to port 22 and enters the cylinder chamber,
Compression work is performed at the position where the maximum confinement volume is 100%.

On the other hand, as shown in Fig. 3b, when the spool 24 is deflected in the direction of arrow B, the valve opening becomes smaller, the gas flow rate at the maximum confinement position becomes smaller, and finally the valve opening becomes completely closed. becomes zero,
Gas enters only from the sub-intake port 23, reducing its maximum confinement volume.

That is, when the rotor 8 rotates at a low speed, gas suction is completed at the normal confinement position, so that the performance of the gas compressor is maintained at a high level. On the other hand, during high-speed rotation, the confinement is completed at the auxiliary intake port 23, but in any case, the valve opening of the main intake port 22 becomes extremely small, so the confinement volume becomes extremely small, and as a result, the amount of gas discharged This results in a decrease in both cooling capacity and driving power.

Figure 4 shows a gas compressor to which this invention is applied,
For a conventional gas compressor with the same specifications as the present invention and a constant main intake port opening, the driving power (power consumption) and cooling capacity vs. rotation speed characteristics when used in a cooler were measured. In the figure,
The solid line is the conventional gas compressor, and the broken line is the gas compressor of the present invention.

As is clear from the figure, according to the measurement results, as the rotation speed increases, the increase in driving power and cooling capacity is automatically suppressed when it reaches approximately 2000 rpm or higher, that is, in the high rotation speed region. was confirmed.

As explained above, according to the gas compressor of the present invention, a sub-intake port is provided on the lagging side of rotor rotation with respect to the main intake port set at the maximum confinement volume position, and the main intake port is connected to the cylinder. With the extremely simple configuration of providing a throttle valve mechanism consisting of an inserted spool valve, it is possible to automatically suppress increases in work capacity and power consumption in the high rotational speed region. In addition, a throttle valve mechanism is provided in the flow path of the cylinder, and the spool valve is operated by the flow velocity of the inflowing gas, so there is no need to provide space for a valve mechanism elsewhere, and the compressor It is not large in size, and since the valve is not activated by a pressure difference, there is no need for seals, and the structure is simple, simply inserting the spring and spool into the flow path. , the confinement volume can be changed. Furthermore, since this design changes the confinement volume, there is no drop in suction pressure and an accompanying increase in compression ratio, and since the discharge gas temperature does not rise, there is no reduction in efficiency due to a rise in gas temperature, etc. It has the following advantages and is suitable for use as a gas compressor for equipment such as car coolers that have large rotational speed fluctuations.

[Brief explanation of drawings]

Figure 1 is a front sectional view of the gas compressor according to this invention, Figure 2 is an exploded perspective view of the main body of the compressor, Figures 3a and b are schematic sectional views showing main parts enlarged, and Figure 4
The figure is a characteristic diagram showing the effect of this invention. 2...Cylinder, 20...Main passage, 21...
Sub-flow passage, 22...Main intake port, 23...Sub-intake port, 24...Spool, 25...Spring.

Claims (1)

[Scope of utility model registration request] A sub-intake port is formed in the cylinder, the opening position of which is set to the main intake port in accordance with the maximum confinement volume of the compression work chamber, and which is shifted to the lagging side in the rotational direction of the rotor, and which communicates with each intake port, and Main and auxiliary flow passages that also communicate with each other are formed through the cylinder, and a spool and a spring that biases the spool in one direction are inserted into the main flow passage, and one end of the spool is connected to the side block. A throttle valve mechanism is configured in the main flow passage, which is installed opposite to the flow hole and operates according to the flow rate of gas sucked into the cylinder chamber from the flow hole, and as the gas flow speed increases, the flow rate of the gas increases. A gas compressor characterized in that the opening degree of the intake port is reduced.