Welding method and compressor

Abstract

The application provides a welding method and a compressor. The welding method is used for welding two parts of the compressor, and comprises the following steps: providing a first part and a second part; coaxially arranging the first part and the second part, and forming a welding area at a joint between the first part and the second part; and welding the welding area by using a laser welding method, so as to fixedly connect the first part and the second part; wherein, when the laser welding is performed, a center line of a laser beam of a laser head in a light emitting direction of the laser beam and a direction of a line connecting the laser head with the axis of the first part and the second part form an included angle, and the included angle is greater than zero. By forming the included angle greater than zero between the light emitting direction of the laser beam and the direction of the axis of the two workpieces to be welded when the welding is performed, the width of the welding seam formed when the welding is performed is greater than the depth of the welding seam, the process window of the welding is increased, the process difficulty of the welding is reduced, and the welding quality of the compressor is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of compressors, in particular to a welding method and a compressor. BACKGROUND

[0002] The pump body (including the cylinder and the cylinder head) of the compressor is made of cast iron or powder metallurgy. Figure 1 As shown in the prior art, the laser welding of the shell 1' and the upper cylinder head 21' of the compressor is performed by a method in which the welding light direction is directed to the material axis. Due to the strong penetration of laser welding, the depth of the weld is much greater than the width of the weld during welding. In order to ensure the welding strength of the shell and the upper cylinder head during laser welding, the weld width is required to be a certain value to obtain good welding strength, and the increase of the weld width will cause the corresponding increase of the weld depth. In this case, the melting amount of the cylinder or the cylinder head in the welding pool will be larger, which will increase the content of chemical elements such as carbon, sulfur and phosphorus in the cylinder or the cylinder head in the welding pool, increase the risk of welding cracks, and there is a risk of welding quality. In order to improve this defect, the prior art usually uses the method of reducing the melting amount of the casting or powder metallurgy material to inhibit the welding crack defect. Therefore, the welding depth needs to be controlled during welding, and the melting amount of the casting or powder metallurgy during welding is reduced.

[0003] However, since the welding depth is proportional to the welding width, the limited welding width will also be reduced at the same time when the welding depth is reduced, which will cause the risk of reduced welding strength. Therefore, the adjustable range of the welding parameters is very small, and in addition to the fluctuation of the welding parameters, material matching precision and material positioning precision, welding instability phenomenon is easy to occur, which will cause welding quality defects, the process window of the compressor during welding is narrow, which affects the welding efficiency and welding quality.

[0004] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the present application, and therefore can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0005] In view of the problems in the prior art, the purpose of the present application is to provide a welding method and a compressor to improve the welding quality of the compressor during welding.

[0006] The embodiment of the present application provides a welding method for welding two components of a compressor, comprising the following steps:

[0007] providing a first component and a second component;

[0008] coaxially arranging the first component and the second component, and forming a welding area at the joint between the two components;

[0009] The welding region is welded by laser welding to fix the first component and the second component;

[0010] The laser beam of the laser head forms an angle with the line connecting the laser head and the axis of the first component and the second component, and the angle is greater than zero.

[0011] In some embodiments, the laser beam, the line connecting the laser head and the axis of the first component and the second component are in the same radial plane.

[0012] In some embodiments, the angle is 14°-42°.

[0013] In some embodiments, the first component and the second component form a weld seam through the welding region after laser welding, and the depth of the weld seam is less than the width of the weld seam.

[0014] In some embodiments, the absolute value of the depth of the weld seam is greater than or equal to 0.1mm.

[0015] In some embodiments, the first component and the second component are both circular in cross-section.

[0016] The weld seam includes a plurality of discrete welding segments along the circumference of the circular member or a closed annular welding segment formed along the circumference of the circular member.

[0017] In some embodiments, each welding segment corresponds to a central angle of 15°, 30°, 60° or 90°.

[0018] In some embodiments, the metallographic structure of the laser weld seam includes at least one of martensite, ferrite, martensite or ferrite.

[0019] In some embodiments, the laser welding is a one-time welding.

[0020] The present application also provides a compressor comprising:

[0021] The housing is provided with an upper housing cover and a lower housing cover at both ends thereof;

[0022] The pump body and the motor stator are arranged inside the housing;

[0023] The pump body includes an upper cylinder cover, a lower cylinder cover and a cylinder therebetween, or the pump body includes an upper cylinder cover, an intermediate plate, a lower cylinder cover, a first cylinder between the upper cylinder cover and the intermediate plate, and a second cylinder between the intermediate plate and the lower cylinder cover;

[0024] The shell and the upper shell cover, the shell and the lower shell cover, the motor stator and the shell, the upper cylinder cover and the shell, the intermediate plate and the shell, the lower cylinder cover and the shell, and the shell and the cylinder are connected by the method.

[0025] The present application relates to a welding method for welding a compressor, in which a laser beam is directed at an angle greater than zero to the axis of the two workpieces to be welded, so that the width of the weld formed during welding is greater than the depth of the weld, thereby increasing the process window and reducing the difficulty of the welding process, and improving the welding quality of the compressor. BRIEF DESCRIPTION OF DRAWINGS

[0026] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments thereof, read in conjunction with the accompanying drawings.

[0027] Figure 1 is a schematic diagram of the welding of the upper cylinder cover and the shell of a compressor in the prior art;

[0028] Figure 2 is a flow chart of the welding method according to an embodiment of the present application;

[0029] Figure 3 is a schematic diagram of the welding of the shell and the upper cylinder cover of a compressor using the welding method according to an embodiment of the present application;

[0030] Figure 4 is a schematic diagram of the welding angle of a compressor using the welding method according to an embodiment of the present application;

[0031] Figure 5 is a schematic diagram of the welding angle of a compressor using the welding method according to an embodiment of the present application;

[0032] Figure 6 is a schematic diagram of the welding of the upper cylinder cover and the shell of a compressor in the prior art.

[0033] REFERENCE NUMERALS:

[0034] 1' shell

[0035] 21' upper cylinder cover

[0036] 1 shell

[0037] 2 pump body

[0038] 21 upper cylinder cover

[0039] 22 lower cylinder cover

[0040] 23 cylinder

[0041] 3 weld

[0042] 4 upper housing cover

[0043] 5 lower housing cover

[0044] 6 motor stator DETAILED DESCRIPTION

[0045] Example embodiments now will be described more fully hereinafter with reference to the accompanying drawings; however, these embodiments can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the example embodiments to those skilled in the art. Like reference numerals refer to like elements throughout the several views and the description of the figures, and a repeated description is omitted. Each of the "or" and "and" in the description herein means "and / or" unless clearly indicated otherwise.

[0046] In the present application, the expressions "one embodiment", "some embodiments", "example", "specific example" or "some examples" etc. mean that a specific feature, structure, material or characteristic represented in connection with the embodiment or example is included in at least one embodiment or example of the present application. Also, the specific feature, structure, material or characteristic represented can be combined in any appropriate way in one or more embodiments or examples. Furthermore, the person skilled in the art can combine and combine the different embodiments or examples represented in the present application and the features of the different embodiments or examples, without contradiction.

[0047] In addition, the terms "first", "second", etc. are used only for the purpose of description, and should not be construed as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Thus, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0048] It should be further understood that the terms "comprise", "include", "contain", "have" indicate the presence of the features, steps, operations, elements, components, items, kinds and / or groups, but do not exclude the presence, occurrence or addition of one or more other features, steps, operations, elements, components, items, kinds and / or groups. The terms "or" and "and / or" used herein are interpreted as inclusive, or mean any one or any combination. Therefore, "A, B or C" or "A, B and / or C" means "any one of the following: A; B; C; A and B; A and C; B and C; A, B and C". There is an exception to this definition only when a combination of elements, functions, steps or operations is inherently mutually exclusive by its nature.

[0049] To solve the problems such as narrow welding process window of the compressor, for example,Figure 2 As shown in the embodiments of the present application, a welding method is provided for welding two components of a compressor, comprising the following steps:

[0050] S100: providing a first component and a second component;

[0051] S200: coaxially arranging the first component and the second component, and forming a welding area at the joint between the two components;

[0052] S300: welding the welding area by laser welding, so as to fixedly connect the first component and the second component;

[0053] In the laser welding, the center line of the laser beam of the laser head is at an angle with the line connecting the laser head and the axes of the first component and the second component, and the angle is greater than zero.

[0054] By arranging the laser beam at an angle greater than zero with the axis of the two components to be welded, the width of the welding seam formed during welding is greater than the depth of the welding seam, the process window of welding is increased, the process difficulty of welding is reduced, and the welding quality of the compressor is improved.

[0055] In some embodiments, the laser beam, the laser head and the axes of the first component and the second component are located in the same radial plane.

[0056] Specifically, the first component in step S100 can be a shell of the compressor, and the second component can be a motor stator of the compressor, a cylinder cover of the compressor, a cylinder of the compressor, an upper shell cover of the compressor or a lower shell cover of the compressor, and the cylinder cover can be an upper cylinder cover, a lower cylinder cover or an intermediate plate. The shell can be welded with one or more of the above-mentioned second components by the above-mentioned welding method, so as to increase the welding process window, improve the welding quality of the compressor and improve the welding efficiency of the compressor.

[0057] As shown in the embodiments of the present application, a welding method is provided for welding two components of a compressor, comprising the following steps: Figure 4 and Figure 5 As shown in the embodiments of the present application, a welding method is provided for welding two components of a compressor, comprising the following steps: Figure 3As shown, first, the shell 1 is coaxially arranged with the upper cylinder cover 2; then, the direction of the laser head is adjusted, so that the light direction of the laser head forms an angle greater than zero with the axial direction of the laser head pointing to the compressor shell 1; under the angle arranged in this way, the upper cylinder cover 2 is welded with the shell 1 along the circumference of the compressor shell, and the welding area after the laser welding of the shell 1 and the upper cylinder cover 2 forms a weld 3, and the depth of the weld 3 is less than the width of the weld 3. By changing the welding angle when the upper cylinder cover is welded with the shell, the laser welding is carried out, the width of the weld is greater than the depth of the weld, the melting amount H of the upper cylinder cover during welding can be reduced, the welding quality can be improved, and the weld crack defect can be reduced. The laser welding is one-time welding, and the metallographic structure of the laser weld includes at least one of martensite or ferrite.

[0058] Specifically, the shell 1 and the upper cylinder cover 2 of the compressor are both circular in cross section; the weld includes a plurality of discrete welding segments along the circumference of the circular member or a closed annular welding segment formed along the circumference of the circular member. When the laser weld includes a plurality of discrete welding segments along the circumference of the circular member, the plurality of welding segments can be uniformly distributed along the circumference of the circular member. For example, each welding segment can be an arc along the circumference of the circular member, and the central angle corresponding to each welding segment can be 15°, 30°, 60° or 90°, etc. The central angle corresponding to each welding segment, or the number of welding segments included in the laser weld, can be determined according to the structure of the two parts of the compressor to be actually welded.

[0059] During welding, the angle between the laser beam and the first and second parts to be welded changes, so that the weld width during laser welding is greater than the weld depth, which is beneficial to improve the welding quality. However, after the welding angle changes, the length of the external shell that needs to be penetrated during welding is lengthened, which increases the difficulty of penetration welding. In order to reduce the increase in welding difficulty caused by the change of the welding angle, according to the Brewster angle principle, the absorption rate of the material to the laser during welding is improved, the welding difficulty is reduced, and the cost of the welding equipment required during welding is reduced.

[0060] According to the existing laser polarization welding theory, when the laser incidence angle θ = 75°-85°, the absorption rate of the material to the laser will be increased by 6-8 times, and the incidence angle at this time is the Brewster angle. The laser incidence angle here is the angle between the normal line of the inclined plane where the keyhole front wall in the molten pool is located and the center line of the laser beam during laser deep penetration welding. According to the test data, during circumferential laser welding, the welding angle α of the laser beam and the workpiece and the laser incidence angle θ have the following relationship:

[0061] α = (90°-θ)*k;

[0062] Different weld width, different angle of the front wall of the spoon hole in the molten pool, k is a proportional coefficient. When the weld width is less than 1mm, k=1.2; when the weld width is greater than 1mm and less than 10mm, k=2.8.

[0063] In order to make the welding angle reach the Brewster angle, improve the absorption rate of the material during welding, and the weld width is greater than 1mm and less than 10mm, then θ=75°-85°, k=2.8, is brought into the above formula, α=14°-42°. Therefore, when the light emitting direction of the laser head and the axial direction of the laser head pointing to the workpiece to be welded are 14°-42°, welding in this range can make the material absorption rate increase by 6-8 times, and reduce the welding difficulty during welding. As shown in the figure, when the welding angle is 14°-42°, the shell 1 and the upper cylinder cover 21 are welded along the clockwise direction or the counterclockwise direction, and the absolute value of the weld depth is greater than 0.1mm. Figure 5

[0064] The embodiment of the present application also provides a compressor, as shown in the figure, the compressor comprises: Figure 6

[0065] The shell 1 is provided with an upper shell cover 4 and a lower shell cover 5 at two ends respectively;

[0066] The pump body 2 and the motor stator 6 are arranged in the interior of the shell 1;

[0067] The pump body comprises an upper cylinder cover 21, a lower cylinder cover 22 and a cylinder 23 between the two. The compressor in the embodiment is a single-cylinder compressor, and in some alternative embodiments, the compressor can be a double-cylinder compressor or a multi-cylinder compressor. When the compressor is a double-cylinder compressor, the pump body 2 comprises the upper cylinder cover 21, an intermediate plate, the lower cylinder cover 22, a first cylinder between the upper cylinder cover 21 and the intermediate plate and a second cylinder between the intermediate plate and the lower cylinder cover 22. Of course, the compressor also comprises a crankshaft with a long shaft part, an eccentric part and an end shaft part, and the crankshaft transmits the rotating force of the motor to the cylinder to compress the refrigerant.

[0068] In the compressor in the embodiment of the present application, at least one of the shell 1 and the upper shell cover 4, the shell 1 and the lower shell cover 5, the motor stator 6 and the shell 1, the upper cylinder cover 21 and the shell 1, the lower cylinder cover 22 and the shell 1, and the shell 1 and the cylinder 23 is connected by the method described above. In the double-cylinder compressor, the intermediate plate and the shell are also welded by the welding method described above.

[0069] ​​When the compressor shell and the pump body are welded by the welding method, the welding seam position can be adjusted, the melting amount on the pump body is reduced, the content of C, S or P in the welding seam is reduced, the welding strength of the pump body and the shell is increased, the crack in the welding seam is reduced, and the welding quality is improved.

[0070] In summary, the welding method and the compressor provided by the present application have the following advantages:

[0071] During the welding, the laser beam has an angle greater than zero with the axis direction of the laser head pointing to the two workpieces to be welded, so that the width of the welding seam formed during the welding is greater than the depth of the welding seam, the process window of the welding is increased, the process difficulty of the welding is reduced, and the welding quality of the compressor is improved.

[0072] When the shell and other connecting pieces are welded at the Brewster angle, the absorption rate of the material to the laser is increased, the welding difficulty is reduced, the welding efficiency is improved, and the investment cost of the laser welding equipment is reduced.

[0073] The above is a further detailed description of the present application in combination with specific preferred embodiments, and the specific implementation of the present application cannot be limited to these descriptions. For ordinary skilled persons in the technical field to which the present application belongs, some simple deductions or substitutions can be made without departing from the concept of the present application, and all of them should be regarded as falling within the protection scope of the present application.

Claims

1. A welding method, characterized in that, The process for welding two components of the compressor includes the following steps: Provide a first component and a second component; The first component and the second component are arranged coaxially, and a welding area is formed at the joint between them; The welding area is welded using laser welding to fix the first component and the second component together. In this process, during laser welding, the center line of the laser beam emission direction of the laser head and the line connecting the laser head with the axes of the first and second components form a welding angle α, which is greater than zero. In laser deep penetration welding, the laser incident angle is the angle between the normal to the inclined plane containing the keyhole front wall in the molten pool and the center line of the laser beam; in circular laser welding, the welding angle α between the laser beam and the workpiece has the following relationship with the laser incident angle θ: α=(90°-θ) k; The angle of the inclined surface of the keyhole front wall in the molten pool varies with different weld widths, and k is a proportionality coefficient; when the weld width is less than 1 mm, k = 1.2; when the weld width is greater than 1 mm and less than 10 mm, k = 2.8, and θ = 75°~85°. The laser beam emission direction and the line connecting the laser head with the axis of the first component and the second component are located in the same radial plane; The first component and the second component form a weld seam in the welding area after laser welding, and the depth of the weld seam is less than the width of the weld seam.

2. The welding method according to claim 1, characterized in that, The welding angle is 14°~42°.

3. The welding method according to claim 1, characterized in that, The absolute value of the depth of the weld is greater than or equal to 0.1 mm.

4. The welding method according to claim 1, characterized in that, Both the first component and the second component have circular cross-sections; The weld seam includes multiple welded segments that are separated along the circumference of the circular part or a closed annular welded segment formed along the circumference of the circular part.

5. The welding method according to claim 4, characterized in that, The central angle corresponding to each of the welded segments is 15°, 30°, 60° or 90°.

6. The welding method according to claim 1, characterized in that, The metallographic structure of the laser-welded seam includes at least one of martensite or ferrite.

7. The welding method according to claim 1, characterized in that, The laser welding is a single-stage welding process.

8. A compressor, characterized in that, include: The housing has an upper cover and a lower cover at its two ends, respectively. The pump body and motor stator are housed inside the casing; The pump body includes an upper cylinder head, a lower cylinder head, and a cylinder between the two, or the pump body includes an upper cylinder head, an intermediate plate, a lower cylinder head, a first cylinder between the upper cylinder head and the intermediate plate, and a second cylinder between the intermediate plate and the lower cylinder head; Wherein, at least one of the following connections is made by the method described in any one of claims 1 to 7: between the housing and the upper cover, between the housing and the lower cover, between the motor stator and the housing, between the upper cylinder head and the housing, between the intermediate plate and the housing, between the lower cylinder head and the housing, and between the housing and the cylinder.

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