JPS597795A - Compressor - Google Patents

Abstract

PURPOSE:To avoid abnormal increase in discharge pressure for aiming at preventing failure, by opening a by-pass passage communicating between an operating chamber and a suction chamber when the discharge pressure exceeds a predetermined value so that a part of fluid in the operating chamber is returned to the suction chamber for decreasing the discharge volume. CONSTITUTION:When a condition is established such that the rotational speed of an engine is increased, and discharge pressure in a discharge chamber 6 is raised to a value exceeding a predetermined value which is set by the force of a set spring 14, a spool 13 is moved to the left as shown in the drawing, overcoming the force of the spring 14, and therefore, a circumferential groove 13a aligns with an opening 13b. As a result, an operating chamber 8 and a suction chamber 4 are communicated together through a by-pass passage 10, and therefore, a part of coolant gas sucked through a suction port 5 is returned from the opening 10b to the suction chamber 4 through the by-pass passage 10 while a vane 3 moves to the opening 10b, thereby the substantial discharge volume is decreased. With this arrangement, excessive rise in discharge pressure is avoided for preventing failures in the compressor.

Description

[Detailed description of the invention] Concerning a preferred compressor.

As is well known, the compressor of an automobile cooler unit is driven by the engine, so its discharge amount is approximately proportional to the engine rotation. By the way, this co/presser for automobile coolers generally operates at an engine speed of 2.5 m, so that it can perform its cooling function even when the engine is running at low speeds. 0
A discharge capacity that provides sufficient cooling capacity at approximately 0.00 rpm is used. For this reason, when the engine is running at high speeds, the amount of refrigerant discharged becomes excessive, and since the capacitor capacity is also fixed, the lower side rises abnormally by 1, and the function of the capacitor deteriorates, especially when the outside temperature is high. This phenomenon is exacerbated and there is a risk that the compressor will malfunction due to back pressure.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional situation, it is an object of the present invention to provide a compressor that can reduce the discharge capacity when the engine rotates at high speeds to avoid an abnormal pressure rise.

In order to achieve the above object, the present invention (1) communicates the first chamber and the suction chamber (7) to form a bypass passage, and operates the upper and lower valves such that the bypass passage tm+ and the discharge pressure exceed a predetermined value. A valve device is installed to make the liquid volume variable.
It is 7.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 and 2, 1 is a rotor housing, 2 is a rotor, and the rotor 21 has a plurality of vanes 3 arranged at equal intervals in sliding contact with the inner peripheral surface of the housing I.
A suction chamber 5 is connected to the suction chamber q and has an inlet opening on the inner peripheral surface of the housing I; 6 is a discharge chamber; 7 is connected to the discharge chamber 6 and is connected to the inner peripheral surface of the housing 1 (this opening (7) At the outlet,
In this embodiment, each pair of toner suction port 5 and discharge lower is 18
They are arranged with a 0 degree phase change. As the rotor 2 rotates in the direction of the arrow in FIG. In the working chamber 8 whose volume increases and decreases as the rotor rotates, the bay 73 passes through the suction port t and is then pressurized, and the discharge port ? The discharge chamber 6 is provided with a one-way valve 9 at the discharge lower.

Here, in the present invention, a bypass passage 10 is provided in communication with the working chamber 8 and the suction chamber v, and inside this bypass passage 10 (when the discharge pressure reaches a predetermined value (WN)2), A valve device 11 that operates to open the valve is interposed.

In this embodiment, a through hole 10a is provided in the rotor housing I (one through hole 10a passing through the side plates +2a and +2b on both sides), and an opening IOb is provided at an arbitrary position in the working chamber 8 connected to this through hole ZOa, and Plate [2a
A bypass passage 10 is formed by providing an opening 10C communicating with the suction chamber DA, and a spool valve body 13 and a set spring 14 are elastically mounted in the through hole 10a to complete the valve device 1.
It consists of The spool valve body 13 is constantly pressed against the surface of the side plate 12b by a set spring 14, and an opening 15 is provided in the side plate 12b so that the discharge pressure in the discharge chamber 6 acts on the end face of the valve body 13. It has become. A circumferential groove 13a is provided at an arbitrary position in the middle of the spool valve body 13, and a passage 13t) is provided in the center of the circumferential groove 13a, communicating with the circumferential groove 13a and opening at the end face on the side where the set spring 14 is disposed. The bypass passage 10 is opened by moving the spool valve body 13 to a position where the circumferential groove 13 section matches the opening 10b.

According to the structure of the above embodiment, under normal conditions, the spool valve body 13 is pressed toward the side plate 12a by the force of the set spring 14, thereby blocking the bypass passage IO. Therefore, all of the refrigerant gas sucked through the suction port 5 is pressurized within the working chamber 8 and is sent out from the discharge lower to the discharge chamber 6I. At this point, the engine speed increases and the discharge chamber 6
The discharge pressure within the set spring 14 increases, and this discharge pressure
If the set value exceeds the force, the spool valve body 1
3 moves to the left against the force of the set spring 14 as shown in FIG.
will now match. As a result, the working chamber 8 and the suction chamber q are connected to each other by the bypass passage 10, and a part of the refrigerant gas sucked from the suction port 5 is transferred to the opening 1θb of the vane 3.
During this period, the suction chamber ψ is returned from the opening 10b via the bypass passage, and the actual discharge capacity is reduced, thereby avoiding an excessive rise in discharge pressure.

In the embodiment shown in FIG. 3, the opening 10b on the working chamber 8 side is
A side plate 12a is provided, while a valve body 16 for opening and closing an opening 100 on the suction chamber l side is integrally formed at the end of the spool valve body 13 on the set spring 14 side via a stay 16a. By moving the spool valve body 13 leftward in the drawing (so that the valve body 16 opens and opens the bypass passage 10), the same discharge volume variable operation as in the previous embodiment can be performed. In addition, this embodiment has the advantage that molding of the circumferential groove 13a and the passage tab of the spool valve body 13 is unnecessary, and the moldability of the spool valve body 13 is good.

In the above embodiments, the valve device 1] is one that operates to open the valve by directly sensing the discharge pressure of the discharge chamber 6.
However, it is also possible to use a combination of a pressure sensor and a solenoid valve.

As described above, according to the present invention, when the discharge pressure exceeds a predetermined value, the bypass passage is opened and a part of the fluid in the working chamber is returned to the suction chamber (the suction chamber) to reduce the discharge volume. It has a great practical effect of 4H in that it can prevent the compressor from rising and thereby prevent the compressor from breaking down.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention, and FIG. 2 (Al
, (B) is a sectional view taken along the line II-II in FIG. 1 showing the same operating state, and FIG. 3 is a sectional view similar to FIG. 2 showing a different example of the present invention. G...Suction chamber, 6...Discharge chamber, 8...Working chamber, 10...
- Bypass passage, 11...valve device. Agent Shiga Fujiya

Claims (1)

[Claims] (1) A compressor characterized in that a bypass passage is formed in communication with the upper and lower working chambers, and a valve device is installed in the bypass passage to operate the upper and lower valves so that the discharge pressure becomes equal to or higher than a predetermined value.