JPS63100288A - Manufacture of scroll hydraulic machine - Google Patents

Abstract

PURPOSE:To improve the volume efficiency of a scroll compressor, by arranging a second mirror board previously applied with polishing and formed into the same shape as a recess between laps in a recess between laps of first mirror, thereby reducing gaps at the tip portion of the lap and the root section. CONSTITUTION:A movable scroll is manufactured by cutting an involute recess such that an involute lap 19 is formed on a first mirror board 20. A second mirror board 21 having same shape as the recess and previously polished surface 26 is fitted in the recess. The portion 24 facing against the first mirror board 20 side of a through-hole 22 of second mirror board 21 through which the lap 19 passes is bevelled. When such a movable scroll is employed, the root section 28 of the lap 19 is not rounded but provided with a sharp edge portion, and since the smoothness of the surface 26 of second mirror board 21 being slided with the lap at a fixed scroll side is improved, leakage of fluid decreases and the volume efficiency increases.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of manufacturing a scroll fluid machine used as a compressor, pump or expander.

BACKGROUND OF THE INVENTION Recently, scroll systems have been attracting attention as compressors for refrigeration, for example. The operating principle of the scroll compressor will be explained with reference to FIGS. 1a to 1d. Figure 1B shows the phase relationship between the movable scroll wrap 1a and the fixed scroll wrap 2a in a state where compression starts at the same time as suction is completed; Figure 1.
This shows a state in which the movable scroll wrap 1a has rotated 90 degrees counterclockwise from the state shown in FIG. 1C. As the state shown in FIG. 1a changes to the state shown in FIG. 1 and FIG. As a result, compressed refrigerant is discharged. The movable scroll wrap 1a further rotates 90 degrees from the state shown in FIG. 1d, thereby returning to its original state, that is, the state shown in FIG. 1.

In FIGS. 1a to 1d, the closed space 12 is formed by the radial contacts 4 of both scroll wraps 12L, 2a.

A conventional scroll compressor based on the above operating principle will be explained with reference to FIGS. 2 and 3. A fixed scroll 2 is fixed to a crank 6 and is composed of an end plate 2b provided with a discharge hole 3 and a fixed scroll wrap 2a having an involute curve standing upright on the end plate 2b. Reference numeral 1 denotes a movable scroll, which consists of an end plate 1b and a movable scroll wrap 1 formed by an involute curve standing upright on the end plate 1b. It is attached via a bearing to the crank portion 81L of the shaft 8 which is rotatably supported, and the movable scroll wrap 1a is assembled to mesh with the fixed scroll wrap 2a. Reference numeral 9 denotes a rotation prevention mechanism provided to prevent the movable scroll 1 from rotating, and is fixedly attached to the frame 6. The shaft 8 is driven by a motor consisting of a stator 10 and a rotor 11 to move the movable scroll 1 relative to the fixed scroll 2 as shown in FIG. 1, thereby increasing the pressure of the refrigerant gas in the closed space 12.

Problems to be Solved by the Invention In the above conventional scroll compressor, the closed space 1
2, for example, leakage of refrigerant gas from the radial contact point 4 or the end face between the fixed scroll wrap 2a and the movable scroll end plate 1b, etc. This is difficult to avoid, and the refrigerant gas in the closed space 12 has the problem that high-temperature gas flows in from the high-pressure section and is overheated, resulting in a decrease in volumetric efficiency and poor performance.

The cause of this will be explained with reference to FIG. FIG. 3 is an enlarged view of the arm portion of FIG. 2. The manufacturing process of the movable scroll 1 and fixed scroll 2 of the conventional scroll fluid machine is N.
After undergoing a cutting process using a G milling machine, it is polished using an NO polishing machine, and efforts have been made to obtain a surface roughness of Rmax-0.8 μm or less, which is required for the compression part of a compressor. However, with current milling machines and polishing machines, it is extremely difficult to polish the bottom portions 13, 14 of a continuous recess formed as in a scroll fluid machine. In particular, it is difficult to polish the root 16 of the fixed scroll lug 1a and the root 16 of the movable scroll wrap 2a as sharply as the corners 17 and 18 at the tips of both wraps, and as shown in FIG. The roundness remained in 15.16. Therefore, the corner 17.1B of the tip of the wrap is connected to the root 15.16 of the wrap opposite to the corner 17.1B of the wrap.
The gaps B, C, and D created between the movable scroll 1 and the fixed scroll 2 were made larger than necessary. And this big gap B.

Gas leakage from C and D caused performance to deteriorate due to the aforementioned drop in volumetric efficiency.

In addition, in order to improve the sealing performance between the pair of scrolls, coating is applied to at least one sliding surface of the parts that slide against each other, and the spiral body of the other scroll member that is overlapped with that of one scroll member is coated. There is one in which an elastic body is arranged in a portion that slides on the tip surface (for example, Japanese Patent Application Laid-Open No. 55-35155). However, since an elastic body made of rubber or the like cannot require very high processing accuracy, it is difficult to adjust the amount of shrinkage to obtain an appropriate frictional force.

Furthermore, using an elastic body for the sliding surface of a scroll member that is subject to high temperatures and high pressures also poses problems in terms of durability.

Therefore, the present invention improves the surface precision of the end plate on which the end surface of the wrap slides to prevent wear of the wrap during use, and also reduces the gap created by the rounded base of the wrap to prevent gas leakage from this gap. Furthermore, the main purpose is to adjust the height accuracy of the lap to reduce the axial clearance and improve volumetric efficiency, as well as to facilitate the manufacture of scroll fluid machines that require high processing accuracy. The purpose is to promote

Means for Solving the Problems In order to achieve the above object, the present invention provides a fixed scroll and a movable scroll by cutting continuous recesses made of spiral curves to form a wrap on a first casting plate. A first step of manufacturing, and a second step of manufacturing a second end plate made of a rigid metal body by forming a through hole with a parallel wire of the same shape as the wrap and polishing at least one surface. After the first step and the second step, the wrap is passed through the through hole of the second end plate, and the second end plate is disposed on the second end plate, and then the fixed scroll and the movable scroll are installed. The third part that engages with each other with the wraps inside
It consists of the following steps.

Function The present invention uses a second head plate which has been polished in advance.
Because it is placed on the end plate, polishing is easy and the surface precision of the end plate can be improved, and the gap caused by the rounded base of the wrap can be reduced, making it possible to reduce the gap between fixed scrolls or movable scrolls that are difficult to process. The volumetric efficiency can be improved without requiring polishing of the bottom surface of the recess and the base of the lap.

Further, by adjusting the second end plate, the lap height accuracy can be adjusted, and the clearance in the axial direction can be reduced.

EXAMPLE Hereinafter, a single-pointed example of the present invention will be explained based on FIGS. 4 and 5.

FIG. 4 is a detailed explanation of the present invention, taking the movable scroll 1 as an example. Similar to the conventional movable scroll,
The first wrap 19 is made of a helical curve such as an involute.
A continuous concave portion consisting of a helical curve is cut to be formed on the end plate 2o. Reference numeral 21 denotes a second end plate, which has a through hole 22 formed in a helical curve having the same shape as the wrap 19.
have. Then, the second end plate 21 is fitted in the direction of the arrow in FIG. 4 so that the wrap 19 passes through the through hole 22. FIG. 5 is a cross-sectional view showing the state in which the second end plate 21 is fixed on the first end plate 2°. 23 is a shaft formed integrally with the first mirror plate 2o. A portion 24 of the through hole 22 of the second mirror plate 21 facing the first mirror plate 20 is chamfered. And the chamfer size is lap 1
The radius is set to be larger than the radius of the roundness created on the two sides of the base of 9. Further, the surface 26 of the second mirror plate 21 is polished before being assembled. Together with the ωF polished surface 2 of the wrap 19, it forms the compression section of the scroll compressor. Wrap 19 is the distance from its tip @
E is polished, and the boundary F between the polished portion and the non-polished portion is located below the second end plate surface 26 (the fixed scroll 2 is also manufactured by the same method). Therefore, the new wrap root 28 formed by the wrap 19 and the second end plate 21 does not have the roundness shown in FIG. 3, but has a sharp corner shape comparable to the corner 29 at the tip of the wrap 19. is obtained. When engaged with a fixed scroll 2 having a similar structure, gaps B, C, and D due to the roundness of the bases 15, 16 of the wraps 1a, 2a as shown in FIG. 3 will no longer occur.

Effects of the Invention As is clear from the above description, the present invention has the following effects by arranging the second end plate, which has been previously polished, on the second end plate.

The first effect is that since the surface of the cupric plate is polished before assembly, there is no need to polish the bottom of the first mirror plate, which is difficult to polish. There is no need to be concerned about the machining pattern carved on the bottom by the polishing tool, the surface precision of the end plate on which the end surface of the lap slides is increased, and wear of the lap due to use can be prevented and a decrease in volumetric efficiency can be prevented.

As a second effect, there is no gap caused by the roundness that occurs at the base where the surface of the wrap and the surface of the second mirror plate extend at right angles. Therefore, the gap between the contact area created by the meshing of the movable scroll and the fixed scroll is kept to a minimum, thereby preventing high temperature and high pressure gas from leaking from the closed space to the low pressure side during the compression process and reducing volumetric efficiency. Can be done.

Furthermore, as a third effect, the height accuracy of the lap is adjusted,
By reducing the axial clearance, it is possible to prevent a decrease in volumetric efficiency. The lap heights of the movable scroll and the fixed scroll have a plus or minus error within a certain range from the standard dimensions due to processing. Scroll fluid machinery engages the movable scroll and the fixed scroll with the wraps inside, so if the error in the height of each wrap is between plus and minus, the axial clearance will not become very large. However, when the laps with positive and negative errors are interlocked, a large deviation occurs. Here, in a scroll fluid machine, compression chambers with different compression ratios are adjacent to each other with a wrap in between, so the axial clearance significantly reduces the volumetric efficiency. Therefore, in order to reduce this clearance, the movable scroll and the fixed scroll are generally selected in the assembly process so that the positive laps or the negative laps mesh. However, this selection is difficult, and it is extremely time-consuming to combine the movable scroll and the fixed scroll with a certain clearance or less, especially in small-volume production. Therefore, by providing a second end plate as in the present invention, the clearance in the axial direction can be adjusted with this second end plate,
The assembly process can be simplified and the volumetric efficiency can be increased.

As described above, the present invention can improve volumetric efficiency and facilitate the manufacture of scroll fluid machines that require high processing accuracy.

[Brief explanation of the drawing]

Figures 1 a, b, c, and d are diagrams of the operating principle of a scroll fluid machine, Figure 2 is a sectional view of a conventional scroll compressor, Figure 3 is an enlarged sectional view of section A in Figure 2, and Figure 4 is a diagram of the operating principle of a scroll fluid machine. FIG. 6 is a perspective view showing an embodiment of the present invention, and FIG. 6 is a sectional view of the movable scroll of the present invention. 19... Wrap, 20... First mirror plate,
21...Second mirror plate, 22...Through hole.

Claims (1)

[Claims] A first step of manufacturing a fixed scroll and a movable scroll by cutting a continuous concave portion formed by a spiral curve to form a wrap on a first end plate, and a through hole having a spiral curve having the same shape as the wrap. a second step of manufacturing a second end plate made of a rigid metallic body by forming and polishing at least one surface thereof, and a through hole in the second end plate after the first step and the second step. A method for manufacturing a scroll fluid machine, comprising a third step of disposing the second end plate on the first end plate by penetrating the wrap, and then engaging the fixed scroll and the movable scroll with each other with the wraps facing inside.