Welding method and compressor

Abstract

The invention 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; the first component and the second component are coaxially arranged, and a welding area is formed at a seam between the first component and the second component; the welding area is welded in a laser welding mode, so that the first component and the second component are fixedly connected; wherein during laser welding, an included angle is formed between the center line of the light emitting direction of a laser beam of a laser head and the direction of a connecting line between the laser head and the axis of the first component and the axis of the second component, and the included angle is larger than zero. During welding, the included angle larger than zero is formed between the light emitting direction of the laser beam and the axis direction, pointing to the two to-be-welded workpieces, of the laser head, the width of a welding seam formed during welding is larger than the depth of the welding seam, a welding process window is enlarged, the welding process difficulty is reduced, and the welding quality of the compressor is improved.

Description

Technical Field

[0001] The invention relates to the technical field of compressors, and in particular to a welding method and a compressor. Background Art

[0002] The pump body (including cylinder and 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 compressor shell 1' and the upper cylinder head 21' is performed by the method of directing the welding light direction to the material axis. Since the characteristic of laser welding is strong welding penetration, the depth of the weld is much greater than the welding width when welding with this method. 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 in welding width will increase the depth of the weld accordingly. In this case, the amount of cylinder or cylinder head melted into the welding pool will be greater, and the content of chemical components such as carbon, sulfur, phosphorus, etc. in the cylinder or cylinder head in the welding pool will increase, increasing the risk of welding cracks and posing welding quality risks. In order to improve this defect in the prior art, reducing the melting amount of castings or powder metallurgy materials is usually used as a method to suppress welding crack defects. Therefore, it is necessary to control the welding depth during welding to reduce the melting amount of castings or powder metallurgy during welding.

[0003] However, since the welding depth is proportional to the welding width, when the welding depth is reduced, the limited welding width will also be reduced synchronously, which will cause the risk of reduced welding strength. Therefore, the adjustable range of welding parameters is very small. In addition, due to the fluctuation of welding parameters, material matching accuracy, material positioning accuracy and other factors, welding instability is prone to occur, resulting in 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 technology section is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

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

[0006] An embodiment of the present invention 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] The first component and the second component are arranged coaxially, and a welding area is formed at the joint between the two components;

[0009] Welding the welding area by laser welding to fix the first component and the second component;

[0010] During laser welding, a center line of a laser beam of a laser head in a light-emitting direction forms an angle with a line connecting the laser head and the axes of the first component and the second component, and the angle is greater than zero.

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

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

[0013] In some embodiments, a weld is formed at the welding area of ​​the first component and the second component after laser welding, and a depth of the weld is smaller than a width of the weld.

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

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

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

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

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

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

[0020] An embodiment of the present invention further provides a compressor, comprising:

[0021] A shell, wherein two ends of the shell are respectively provided with an upper shell cover and a lower shell cover;

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

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

[0024] Among them, at least one of 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 middle plate and the shell, the lower cylinder cover and the shell, and the shell and the cylinder is connected by the method described above.

[0025] The present invention is a welding method for welding a compressor. During welding, the light emitting direction of the laser beam and the axial direction of the laser head pointing to the two workpieces to be welded form an angle greater than zero, so that the width of the weld formed during welding is greater than the depth of the weld, the welding process window is increased, the welding process difficulty is reduced, and the welding quality of the compressor is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Other features, objectives and advantages of the present invention will become more apparent from a reading of the detailed description of non-limiting embodiments made with reference to the following accompanying drawings.

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

[0028] Figure 2 is a flow chart of a welding method provided by an embodiment of the present invention;

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

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

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

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

[0033] Reference numerals:

[0034] 1' Shell

[0035] 21' upper cylinder head

[0036] 1 Housing

[0037] 2 Pump body

[0038] 21 Upper cylinder head

[0039] 22 Lower cylinder head

[0040] 23 Cylinder

[0041] 3 Welding seams

[0042] 4 Upper cover

[0043] 5 Lower case cover

[0044] 6 Motor stator DETAILED DESCRIPTION

[0045] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present invention will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. In the figures, the same reference numerals represent the same or similar structures, and thus their repeated description will be omitted. "or" and "or" in the specification may both mean "and" or "or".

[0046] In the representations of the present application, the representations with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics represented in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. Moreover, the represented specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples represented in the present application and the features of the different embodiments or examples, unless they contradict each other.

[0047] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the representation of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0048] It should be further understood that the terms "comprises" and "includes" indicate the presence of 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 of the following: A; B; C; A and B; A and C; B and C; A, B and C". Exceptions to this definition will only occur when the combination of elements, functions, steps or operations is inherently mutually exclusive in some way.

[0049] To solve the problems of narrow welding process window of compressor, such as Figure 2 As shown, an embodiment of the present invention provides a welding method for welding two components of a compressor, comprising the following steps:

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

[0051] S200: The first component and the second component are coaxially arranged, and a welding area is formed at a joint between the two components;

[0052] S300: Welding the welding area by laser welding to fix the first component and the second component together;

[0053] During laser welding, a center line of a laser beam of a laser head in a light-emitting direction forms an angle with a 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 making the light emitting direction of the laser beam and the axial direction of the laser head pointing to the two workpieces to be welded form an angle greater than zero during welding, the width of the weld formed during welding is greater than the depth of the weld, thereby increasing the welding process window, reducing the welding process difficulty, and improving the welding quality of the compressor.

[0055] In some embodiments, the light emitting direction of the laser beam and the line connecting 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 may be a housing of the compressor, and the second component may be a motor stator of the compressor, a cylinder head of the compressor, a cylinder of the compressor, an upper shell cover of the compressor, or a lower shell cover of the compressor, wherein the cylinder head is an upper cylinder head, a lower cylinder head, or an intermediate plate. The housing may be welded to the above-mentioned one or more second components by the above-mentioned welding method, thereby increasing the welding process window, improving the welding quality of the compressor, and improving the welding efficiency when welding the compressor.

[0057] like Figure 4 and Figure 5 FIG. 1 is a schematic diagram showing a method for welding the upper cylinder cover and the housing of a compressor using a welding method provided by an embodiment of the present invention. Figure 3As shown, first, the shell 1 and the upper cylinder head 2 are coaxially arranged and positioned; then, the direction of the laser head is adjusted so that the light emitting direction of the laser head and the axial direction of the laser head pointing to the compressor shell 1 form an angle greater than zero; at this set angle, the upper cylinder head 2 and the shell 1 are welded along the circumference of the compressor shell, and the shell 1 and the upper cylinder head 2 form a weld 3 in the welding area after laser welding, 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 head and the shell are welded, the width of the weld is greater than the depth of the weld, which can reduce the melting amount H of the upper cylinder head during welding, improve the welding quality, and reduce the weld crack defect. The laser welding is a 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 head 2 of the compressor are both circular in cross-section; the weld includes multiple welding segments separated along the circumference of the circular part or a closed annular welding segment formed along the circumference of the circular part. When the laser weld includes multiple welding segments separated along the circumference of the circular part, the multiple welding segments can be evenly distributed along the circumference of the circular part. For example, each welding segment can be an arc along the circumference of the circular part, and the arc, i.e., each welding segment, corresponds to a central angle of 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 components of the compressor actually welded.

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

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

[0061] α=(90°-θ)*k;

[0062] Different weld widths have different angles of the front wall of the keyhole in the molten pool, and k is the proportional 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.

[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, θ=75°~85°, k=2.8, and are substituted into the above formula to obtain α=14°~42°. Therefore, when the light emitting direction of the laser head is 14°~42° with the axial direction of the laser head pointing to the workpiece, welding within this range increases the absorption rate of the material by 6~8 times, reducing the difficulty of welding. Figure 5 As shown, when the welding angle is 14° to 42°, the housing 1 and the upper cylinder cover 21 are welded in a clockwise direction or a counterclockwise direction, and the absolute value of the depth of the weld is greater than 0.1 mm.

[0064] The embodiment of the present invention further provides a compressor, such as Figure 6 As shown, the compressor comprises:

[0065] A housing 1, with an upper housing cover 4 and a lower housing cover 5 respectively disposed at both ends of the housing;

[0066] The pump body 2 and the motor stator 6 are placed inside the housing 1;

[0067] The pump body includes an upper cylinder head 21, a lower cylinder head 22 and a cylinder 23 therebetween. The compressor in this embodiment is a single-cylinder compressor. In some alternative embodiments, the compressor may be a two-cylinder compressor or a multi-cylinder compressor. When the compressor is a two-cylinder compressor, the pump body 2 includes an upper cylinder head 21, an intermediate plate, a lower cylinder head 22, a first cylinder between the upper cylinder head 21 and the intermediate plate, and a second cylinder between the intermediate plate and the lower cylinder head 22. Of course, the compressor also includes a crankshaft having a long axis portion, an eccentric portion and an end axis portion, and the crankshaft transmits the rotational force of the motor to the cylinder to compress the refrigerant.

[0068] In the compressor of the embodiment of the present invention, at least one of the housing 1 and the upper housing cover 4, the housing 1 and the lower housing cover 5, the motor stator 6 and the housing 1, the upper cylinder cover 21 and the housing 1, the lower cylinder cover 22 and the housing 1, and the housing 1 and the cylinder 23 is connected by the above-mentioned method. In the case of a two-cylinder compressor, the intermediate plate and the housing are also welded by the above-mentioned welding method.

[0069] When the compressor casing and the pump body are welded by the above welding method, since the width of the weld is greater than the depth of the weld during welding, the weld position can be adjusted to reduce the amount of melting on the pump body, reduce the content of elements such as C, S or P in the weld, increase the welding strength between the pump body and the casing, reduce the generation of cracks in the weld, and improve the welding quality.

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

[0071] During welding, the emitting direction of the laser beam forms an angle greater than zero with the axial direction of the laser head pointing to 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 welding process window, reducing the welding process difficulty, and improving the welding quality of the compressor.

[0072] When Brewster angle welding is used to weld the shell and other connecting parts, increasing the material's absorption rate of laser can reduce welding difficulty, improve welding efficiency, and reduce the investment cost of laser welding equipment.

[0073] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A welding method, characterized in that: The process for welding two parts of a compressor includes the following steps: providing 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 the two components; Welding the welding area by laser welding to fix the first component and the second component; During laser welding, a center line of a laser beam of a laser head in a light-emitting direction forms an angle with a line connecting the laser head and the axes of the first component and the second component, and the angle is greater than zero.

2. The welding method according to claim 1, characterized in that: The light emitting direction of the laser beam and the line connecting the laser head and the axes of the first component and the second component are located in the same radial plane.

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

4. The welding method according to claim 1, characterized in that: A weld is formed in the welding area of ​​the first component and the second component after laser welding, and a depth of the weld is smaller than a width of the weld.

5. The welding method according to claim 4, characterized in that: The absolute value of the depth of the weld is greater than or equal to 0.1 mm.

6. The welding method according to claim 4, characterized in that: The first component and the second component both have circular cross-sections; The weld includes a plurality of weld segments separated along the circumference of the circular member or a closed annular weld segment formed along the circumference of the circular member.

7. The welding method according to claim 6, characterized in that: The central angle of each welding section is 15°, 30°, 60° or 90°.

8. The welding method according to claim 4, characterized in that: The metallographic structure of the laser weld includes at least one of martensite or ferrite.

9. The welding method according to claim 1, characterized in that: The laser welding is one-time welding.

10. A compressor, characterized in that: include: A shell, wherein two ends of the shell are respectively provided with an upper shell cover and a lower shell cover; The pump body and the motor stator are placed inside the housing; The pump body includes an upper cylinder head, a lower cylinder head and a cylinder therebetween, or the pump body includes an upper cylinder head, a middle plate, a lower cylinder head, a first cylinder between the upper cylinder head and the middle plate, and a second cylinder between the middle plate and the lower cylinder head; Among them, at least one of 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 middle plate and the shell, the lower cylinder cover and the shell, and the shell and the cylinder is connected by the method described in any one of claims 1 to 9.

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