JPS61258987A - Rotary compressor - Google Patents

Abstract

PURPOSE:To improve surface roughness, shape and dimensional accuracies, wear-proof characteristic, and compression characteristic, reduce noise, and get smoother sliding characteristic between a vane groove and a vane by applying supersonic shaving machining on the vane groove. CONSTITUTION:By using a supersonic shaving machine 16, namely giving supersonic vibration of appropriate frequency and amplitude through a supersonic vibration unit 16c to a shaving cutter 16a attached to a holder 16b and by moving the vibration unit 16c, the holder 16b and the shaving cutter 16a by means of a press device such as a hydraulic unit from the top downward in the direction of the arrow, both of the side walls of the vane groove 1c of a cylinder 1 facing in parallel each other are simultaneously machined. With this, shape accuracy of the vane groove 1c is improved, sliding characteristic of the vane 2 is substantially improved and wear-proof characteristics of the both components are improved. And because of stabilized dimensional accuracy and parallelism, gap between the vane groove 1c and the vane 2 can be made smaller, which reduces gas leakage amount, improves volumetric efficiency and reduces rattling of the vane 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a rotary compressor, and particularly to a compressor structure suitable for improving performance and wear resistance through smooth sliding of vanes.

[Background of the invention]

The compression mechanism of a rotary compressor is basically simpler than that of a reciprocating compressor, etc., but on the other hand, the vane grooves and vanes carved into the cylinder play an important role, and the high-pressure compression chamber and low-pressure It is necessary to partition the suction chamber, and to operate with a gap between the vane groove and the vane in response to the eccentric movement of the roller. In particular, the vane grooves have parallel and opposing side walls, and are usually narrow due to the thickness of the cylinder, making precision machining of the side walls difficult.

The general method currently used to process vane grooves is cutting using a broach blade with a large number of blades arranged in sequence. According to this, cutting marks are generated in a direction perpendicular to the sliding direction of the vane. The surface roughness is extremely poor, and the flatness and straightness are also deteriorated.

In addition, broaching requires a relatively large machining allowance, and since a large number of blades are formed symmetrically or are likely to be formed individually unbalanced with respect to the center of the broach, cutting stress is large and the depth of cut of each blade is large. Due to this imbalance, coupled with the relationship between the rigidity of the workpiece, the parallelism and dimensional accuracy between the opposing side walls are extremely unstable, which is a disadvantage.

As a result, conventional rotary compressors incorporating cylinders with the above-mentioned problems suffer from tIX friction, wear, and increased friction noise during sliding due to high-pressure gas loads, as well as problems with parallelism and dimensions. It had defects such as vane grooves due to deterioration in accuracy, decrease in volumetric efficiency due to high-pressure gas leakage due to increased gap between the vanes, and generation of tapping noise due to the gap between the vanes.

Related to this type of precision machining, for example, Nikkan Kogyo Shimbun, ``Ultrasonic Technology Handbook'' published on November 25, 1960, and Coronasha, edited by the Precision Machinery Society, ``New "Revised Precision Handbook" can be cited.

[Purpose of the invention]

The purpose of the present invention is to use ultrasonic shaving to improve the roughness, shape, and dimensional accuracy of cylinder vane grooves, instead of using the conventional broaching method, and to improve smooth sliding performance between the vane grooves and the vanes. The object of the present invention is to provide a rotary compressor that achieves improved wear performance, improved compression performance, and reduced noise.

[Summary of the invention]

To achieve this purpose, in order to alleviate the cutting stress caused by conventional broaching, ultrasonic vibration is applied to the shaving blade in the cutting direction to cause intermittent cutting. This is a high-performance rotary type in which the cutting edge accuracy (dimensional accuracy, cutting edge symmetry accuracy) is improved by reducing the size of the cylinder, and the cylinder is manually machined with ultra-precision machining with low cutting force that is not affected by the cylinder design shape. Developed a compressor.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 6 and reference photographs 1.2. FIG. 1 shows an example of a rotary compressor structure according to the present invention. In FIG. 1, 1 is a cylinder, 2 is a vane, 3 is a crankshaft, 4 is an end plate, that is, an upper bearing, 5 is an end plate, that is, a lower bearing, 6 is a roller, 7 is a rotor, 8 is a stator, 9 is a closed container, and 10 is a spring.

That is, the pump section 11 includes an upper bearing 5, a cylinder 1
, a lower bearing 5, a roller 6, a vane 2, a spring 10, a crankshaft 3, and a rotor.
It is fixed to the closed container 9 by welding or the like. Also, stator 8
is joined to the closed container 9 by firing or the like with an appropriate gap between the outer diameter of the rotor 7 and a rotary compressor.

Figure #2 explains the pump 11 in more detail.
The figure shows the compressor inverted and with the lower bearing 5 removed. That is, the cylinder 1 has a substantially cylindrical shape with a hole 1a having precise precision opened in the center thereof, and has a projecting portion 1b on a part of its outer diameter side. A vane groove IC consisting of two full walls facing in parallel from the inner peripheral side of the hole 1a is provided in the projecting portion 1b. A flat vane 2 is inserted into the vane groove IC, and its tip 2a is inserted into the vane groove IC.
is in contact with the outer diameter of the roller 6 inserted into the eccentric portion 3a of the crankshaft 3 inserted into the upper bearing 4. The spring 10 is engaged in a horizontal hole 1d formed in the projecting portion 1b of the cylinder 1, and its tip presses against the back surface 2b of the vane 2. This rotary compressor has three crankshafts
As the roller 6 rotates, the roller 6 makes an eccentric rotational movement, and in synchronization with this, the vane 2 repeats reciprocating movement within the vane groove IC of the cylinder 1, partitioning the high pressure chamber 12 and the low pressure chamber 13, and continuously inhaling, It exhibits the so-called compressor operation of discharge. mosquito\
In a rotary compressor, the vane groove IC is connected to the vane 2.
Then, the reciprocating sliding is repeated while receiving the side pressure induced by the discharge pressure and the roller rotation force. Further, the gap between the fitting portion of the vane IC and the vane 2 becomes a leakage area for high-pressure discharged gas, and becomes a major factor in reducing the volumetric efficiency.

More specifically, among the vane groove precision, surface roughness, flatness, and straightness affect the wear and sliding noise of the vane 72 and the vane groove IC, and the width dimension and parallelism of the vane groove IC affect both. This leads to an increase in the clearance of the exhaust gas and induces leakage of discharged gas. Also, this clearance is the top dead center of the compressor (
Due to the pressure fluctuation that occurs at the roller position where the vane is most retracted, the vane 2 swings laterally within the vane groove IC, and collision noise is generated in proportion to the size of the clearance.

Therefore, the above-mentioned defects such as wear, gas leakage, noise, etc. can be greatly improved by improving the width dimensional accuracy and shape accuracy of the vane groove.

FIG. 3 shows an example of broaching, which is common as a conventional vane groove IC processing method.
It consists of a traveling mechanism section (not shown) that moves the holder 15 holding the holder 4 in a linear manner with high precision, a main body that supports this, a coolant device, and a control device (none of which are shown), as indicated by the arrow in FIG. 3. Cut the vane groove IC of the cylinder 1 in the direction shown in FIG. In this case, the vane groove IC accuracy is affected by factors such as the high cutting stress, fluctuations in machining allowance or workpiece rigidity, symmetrical accuracy of the broach blade, sharpness, and elastic deformation of the blade holder 15, especially the parallelism and groove. It has the disadvantage that it is difficult to measure the width. In addition, it is difficult to control the surface roughness uniformly with broached blades or with a large number of blades, and deep scratches occur in the cutting direction due to the appearance of built-up edges, as shown in Reference Photo 1 and Figure 4. The cut surface condition (micrograph of sintered metal material) was as shown in the example, with surface roughness and extremely rough finishing accuracy.

Therefore, there is a method of processing using an ultrasonic shaving blade 16 as shown in FIG. 5 with a small amount of machining allowance and low cutting force. That is, an ultrasonic vibrator 16c applies ultrasonic vibrations of appropriate frequency and amplitude to the shaving blade 16a attached to the holder 16b, and the vibrator is applied from above in the direction of the arrow by a pressure device 16a such as a hydraulic unit. 16C1 holder 1
The 6b1 shaving blade 16a is moved to simultaneously cut both parallel opposing walls of the vane groove IC of the cylinder 1.

In this case, if the machining allowance is large in relation to the pre-processing dimensions, the shaving blade 16a may be changed in stages to obtain the appropriate machining allowance, or the pre-processing may be broaching, which is the conventional vane groove IC processing method, to obtain the appropriate machining allowance. There are ways to get it.

According to this ultrasonic shaving process, cutting stress is significantly reduced due to micro-interrupted cutting, and workpiece rigidity is excellent, even if it is small, and machinability is excellent, and stable parallelism or width dimension can be obtained. Further, the shaving blade 16a is a fifth blade.
As shown in the figure, combined with miniaturization of the machining allowance, the overall length is shortened and rigidity is improved.Also, the number of teeth can be extremely reduced along with the reduction of cutting stress, which improves the symmetrical accuracy of both cutting edges and the sharpness. It is easy to manage and can maintain dimensional accuracy and shape accuracy during continuous processing.

Furthermore, the surface roughness is extremely low because the shaving blade 16a undergoes minute forward and backward movements due to the application of ultrasonic waves, which causes cutting on the forward side and lapping function of the side wall surface of the vane groove IC by the cutting edge on the backward side. Significant improvement.

Reference photo 2 shows a microscopic photo of the ultrasonically shaved surface of the sintered material, and FIG. 6 shows the roughness measurement results of the same surface.

That is, on the broached surface of Reference Photo 1, it is clearly seen that there are strong and continuous cutting marks caused by the broach.

Reference Photo 2 On the surface processed by ultrasonic cutting, the cutting marks appear to be continuous but faded in dots. FIGS. 4 and 6 show examples of roughness measured in a direction perpendicular to these scratches, and the ultrasonic shaving surface has been improved to about 1/2o.

〔Effect of the invention〕

According to the present invention, as described above, by incorporating into a rotary compressor a vane groove subjected to highly accurate ultrasonic shaving, especially a cylinder 1 having an ultra-precise surface roughness of 0.57xRZ or less, Coupled with improved shape accuracy,
The sliding characteristics of the vane 2 are greatly improved, and the wear resistance of both is improved. In addition, since dimensional accuracy and parallelism can be stabilized, it is possible to make the gap between the vane groove 1c and the vane 2 very small, which makes it possible to reduce the amount of gas leaking from the gap, resulting in volumetric efficiency. At the same time, the knocking noise of the vane 2 is reduced, resulting in a low-noise rotary compressor. Therefore, the compressor according to the present invention is extremely effective in improving the reliability of electric refrigerators, room air conditioners, etc. equipped with the compressor.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing an example of a rotary compressor according to the present invention, FIG. 2 is a perspective view showing an example of the configuration of the pump section of the compressor shown in FIG. A perspective view showing an example, Fig. 4 is a surface roughness measurement chart of the machined surface of reference photo 1, Fig. 5 is a perspective view showing an example of the basic configuration of an ultrasonic shaving machine, and Fig. 6 is a reference photo. 2 is a surface roughness measurement chart of the machined surface of No. 2. FIG. Reference photo 1 is a microscopic photo, and reference photo 2 is a microscopic photo. 1... Cylinder, 1a... Cylinder inner diameter hole, 1b.
...Protrusion on the outer periphery of cylinder 1, IC...vane groove, 1
d... Lateral hole provided in the overhanging portion 1b, 2... Vane, 2
a... Tip of the vane, 2b... Back side of the vane, 3...
・Crankshaft, 3a... Eccentric part of crankshaft 3, 4... Upper bearing, 5... Lower bearing, 6... Roller, 7... Rotor, 8... Stator, 9...・Airtight container, 10...Spring, 11
... pump, 12 ... high pressure chamber, 13 ... low pressure chamber,
14... Broach blade, 15... Holder for broach blade 14, 16... Ultrasonic shaving machine, 16a...
Shaving blade, 16b... Holder for the shaving blade 16a, 16C... Vibrator, 16d... Pressure device. Taku 1 and tank 6

Claims (1)

[Claims] In the vane groove provided in the cylinder of a rotary compressor,
A rotary compressor characterized by having vane grooves formed by ultrasonic shaving.