Automated Fixture for Welding Compressor Lower Cover and Leg

Abstract

The automatic fixture for welding the compressor lower cover and the supporting legs of the present invention relates to the technical field of auxiliary fixtures for welding equipment, and particularly to an automatic fixture that can accurately position and ensure relevant dimensions. The bottom of the lower cover servo lifting mechanism of the present invention is installed on the base, and the top is connected to the bottom plate installed in the middle of the upper part of the base; the lower cover end face positioning ring and the pneumatic chuck are installed on the upper part of the bottom plate; the lower cover pressing cylinder is installed on the side of the servo lifting mechanism; there are 4 sets of supporting leg positioning and fastening mechanisms, which are evenly distributed around the upper periphery of the upper mounting plate; the displacement sensor at the top of the lower cover is fixedly installed on the ground or the fixed part of the equipment; the position sensor at the top of the lower cover is used as a signal input end to communicate with the PLC, and the lower cover servo lifting mechanism is used as a signal receiving end to communicate with the PLC. The technical solution of the present invention solves the problems in the prior art, such as large height fluctuations of the supporting legs after welding, the need to use tools for picking up parts, low compatibility, which is not conducive to quality management and the improvement of production efficiency, etc.

Description

Technical Field

[0001] The invention discloses an automated fixture for welding a compressor lower cover and a support leg, which relates to the technical field of auxiliary fixtures for welding equipment, and in particular to an automated fixture that can accurately position and ensure relevant dimensions. Background Art

[0002] Currently, the housing of vertical rotary compressors, especially scroll and rotor compressors, mainly includes: an upper cover assembly, a cylinder, and a lower cover assembly. The lower cover assembly usually includes: a lower cover, pipe fittings, an oil sight glass, and support legs.

[0003] The support legs have two main functions: 1. In the whole machine assembly line, they will participate in the processing and positioning of multiple processes; 2. When used by customers, they are the only structure for installing and fixing the compressor and refrigeration system.

[0004] There are currently two common methods for connecting the lower cover and the legs: 1. Stamping the lower cover and legs from a single sheet of sheet metal; 2. Welding the lower cover and legs (usually three or four; this patent covers four). The former offers better dimensional consistency, but due to the more complex molding process, the material and mold costs are higher. The latter offers lower material costs, but the dimensional consistency after welding is poor, especially due to the large height fluctuations between the multiple legs.

[0005] The fluctuation of the support leg height will affect the non-directional tilt of the compressor, which will have a certain adverse effect on the subsequent assembly of the whole machine on the production line and the installation of the compressor and the refrigeration system.

[0006] The leg height positioning mechanism and the lower cover end face positioning mechanism of traditional fixtures are typically set to fixed dimensions according to relevant dimensional requirements and remain stationary relative to each other. While this ensures a strict height difference between the leg and the lower cover end face, the lower cover height typically fluctuates within 1.5mm due to cost and process limitations. This results in uncontrollable fluctuations in the gap between the lower cover and the leg assembly within batches. Experimental verification has shown that a larger gap results in greater weld shrinkage after welding, leading to greater height fluctuations in the leg after processing.

[0007] On the other hand, due to limited welding space, traditional fixtures are often equipped with manual tightening mechanisms that can only provide low pressure, or even no mechanism at all. Each leg typically has two weld passes, for a single component, totaling eight. As the welds cool after welding, they shrink to a certain extent, accompanied by significant forces. Therefore, if sufficient tightening force is not provided, the component is likely to separate from the positioning surface at the start of welding, resulting in significant height fluctuations in the leg after welding.

[0008] Meanwhile, due to the component of the shrinkage of the weld bead in the radial direction of the leg, a pressure is exerted on the positioning pin by the leg in the radial direction. Therefore, after welding, the operator needs to use tools to pick up the part, otherwise it is very difficult to remove.

[0009] In addition, when there are multiple specifications for some dimensions, especially the distance from the leg to the end face of the lower cover, multiple jigs are required or individual parts of a jig need to be switched. This is not conducive to quality management and the improvement of production efficiency.

[0010] Generally, the height difference of the legs of a single compressor is controlled within 1 mm. However, in engineering, due to the above-mentioned disadvantages of traditional jigs, it is very difficult to achieve a high yield rate.

[0011] In view of the problems existing in the above-mentioned prior art, it is very necessary to research and design a new type of automatic fixture for welding the lower cover and legs of a compressor, so as to overcome the problems existing in the prior art. Summary of the Invention

[0012] According to the technical problems proposed by the above-mentioned prior art, such as large shrinkage of the leg during welding, resulting in large fluctuations in the height of the leg after welding; tools are needed to pick up the part after welding, increasing the difficulty of picking up; low compatibility, not conducive to quality management and the improvement of production efficiency, etc., an automatic fixture for welding the lower cover and legs of a compressor is provided. The present invention mainly uses a lower cover fixing device with high integration and a jig for welding multiple legs, so as to achieve the purpose of ensuring small fluctuations in leg welding, convenient part picking, improving work efficiency and enhancing product quality.

[0013] The technical means adopted by the present invention are as follows:

[0014] An automatic fixture for welding the lower cover and legs of a compressor includes: a base, a bottom plate, a lower cover end face positioning ring, a pneumatic chuck, a lower cover pressing cylinder, a lower cover servo lifting mechanism, a leg positioning and fastening mechanism, a lower cover top position sensor, a lower cover, a leg, a PLC and a human-machine interface;

[0015] Further, the bottom of the lower cover servo lifting mechanism is installed on the base, and the top is connected to the bottom plate installed in the middle of the upper part of the base;

[0016] Further, the lower cover end face positioning ring and the pneumatic chuck are installed on the upper part of the bottom plate to position the lower cover placed on the bottom plate;

[0017] Further, the lower cover pressing cylinder is installed on the side of the servo lifting mechanism to press and fix the lower cover placed on the bottom plate;

[0018] Further, there are 4 sets of leg positioning and fastening mechanisms, which are evenly distributed on the upper periphery of the upper mounting plate, used for positioning and fastening the legs to facilitate welding with the lower cover;

[0019] Further, the displacement sensor at the top of the lower cover is fixedly installed on the ground or the fixed part of the equipment;

[0020] Further, the position sensor at the top of the lower cover communicates with the PLC as a signal input end, and the servo lifting mechanism of the lower cover communicates with the PLC as a signal receiving end.

[0021] Further, the base includes: mounting plate A, frame body, and upper mounting plate;

[0022] Further, the upper and lower parts of the frame are respectively equipped with an upper mounting plate and mounting plate A to form a frame structure;

[0023] Further, the upper mounting plate is a hollow plate-like structure.

[0024] Further, the servo lifting mechanism of the lower cover includes: servo electric cylinder, mounting plate B, guide shaft, and support frame;

[0025] Further, the lower end face of the cylinder body of the servo electric cylinder is installed on the upper part of mounting plate A, and the cylinder rod is connected to the bottom of mounting plate B, driving mounting plate B to move in the vertical space, passing through the upper mounting plate but not interacting with the upper mounting plate;

[0026] Further, the bottom of the support frame is installed on the upper end face of mounting plate B, and the top is connected to the bottom of the bottom plate;

[0027] Further, there are at least two guide shafts, evenly distributed between the bottom plate and the upper mounting plate. The guide shafts are fixed to the lower surface of the bottom plate through guide shaft seats, and their linear bearings are connected to the upper surface of the upper mounting plate to ensure the smoothness and accuracy during lifting.

[0028] Further, the lower cover clamping cylinder is installed on the side of the support frame; a pressure arm is also installed on the lower cover clamping cylinder; a pressure head is installed at the front end of the pressure arm; the pressure arm drives the pressure head to swing from the initial position to above the lower cover, and under the action of the pressure arm, the pressure head clamps the upper cover.

[0029] Further, there are 4 sets of leg positioning and fastening mechanisms, evenly distributed on the outer periphery of the upper part of the upper mounting plate. Each set of leg positioning and fastening mechanisms includes: mounting frame A, platform, positioning pin, cylinder, side baffle, plunger, leg clamping cylinder, pressure arm, and pressure block;

[0030] Further, mounting frame A is fixedly installed on the upper part of the upper mounting plate;

[0031] Further, a platform is installed on the upper end face of mounting frame A;

[0032] Further, according to the radial distance requirements between the legs and the lower cover, positioning pins are installed on each mounting surface of the platform;

[0033] Further, the cylinder block of the cylinder is installed on the lower end face of the platform by screws, and the piston rod passes through the platform and is connected to the positioning pin, so that the positioning pin can move along its axial direction;

[0034] Further, a side baffle is installed on each side of the positioning pin;

[0035] Further, a plunger is installed outside the positioning pin;

[0036] Further, under the combined action of the plunger and the side baffle, the direction of the outrigger can be restricted so that it points to the center of the lower cover;

[0037] Further, the outrigger pressing cylinder is fixed to the side of the platform by screws. A pressure arm is installed on the outrigger pressing cylinder, and a pressing block is installed at the lower part of the front end of the pressure arm; The outrigger pressing cylinder swings from the initial position to directly above the outrigger and finally presses the outrigger through the pressure arm driving the pressing block.

[0038] Further, the position sensor at the top end of the lower cover includes: a probe, a guide rod cylinder, a position sensor and mounting bracket B;

[0039] Further, mounting bracket B is fixedly installed on the ground or the fixed part of the equipment;

[0040] Further, the guide rod cylinder is installed on mounting bracket B, and the moving direction of its piston rod is consistent with the axial direction of the lower cover;

[0041] Further, the probe is installed at the front end of the piston rod of the guide rod cylinder and moves synchronously with the piston rod;

[0042] Further, a position sensor is installed on the side of the guide rod cylinder. The position sensor can accurately detect the position of the piston ring in the guide rod cylinder, that is, the spatial position of the probe end face.

[0043] The usage method of the present invention is as follows:

[0044] 1. Before the initial use, according to the dimensional requirements of the lower cover end face and the outrigger height of the initial model, combined with the physical scale, calibrate the user origin of the lower cover servo lifting mechanism of the initial model, that is, the pre-installation position;

[0045] If there are multiple specifications for this dimension, there is no need to repeat the calibration. Based on the difference between other models and this dimension of the initial model, and based on the user origin data of the initial model, a new model file can be added in the human-machine interface and the corresponding origin data can be set. When the model is changed, the servo lifting mechanism will automatically move to the pre-installation position. Through the above method, the model can be changed quickly without the need to confirm the fixture size. The compatibility of the fixture is improved to the greatest extent.

[0046] After the origin of the lower cover servo lifting mechanism is calibrated, place the lower cover standard part on the fixture, center and fasten it, and calibrate the user origin of the position sensor at the top end of the lower cover.

[0047] Adjust the air source pressure of the lower cover pressing mechanism and the leg pressing mechanism, confirm whether the parts are separated from the positioning surface during the welding process, and finally confirm the safety air source pressure setting value of the pressing mechanism. Thus, the full effectiveness of the positioning reference can be ensured, and the height fluctuation of each leg on a single part is effectively controlled.

[0048] Second, during actual assembly, place the lower cover and legs in the relevant positions, press the equipment fixture button, and the fixture will automatically perform precise positioning and fastening in the established order. After all fastening is completed, the position sensor at the top of the lower cover starts to work, detects the height coordinates at the top of the lower cover, transmits the results to the PLC. The PLC will compare the results with the standard origin position, identify the deviation amount, and control the lower cover servo lifting mechanism to move the corresponding distance to compensate for the deviation amount. After the compensation action is completed, it moves to the equipment welding area through other motion mechanisms (not related to this patent) to perform welding processing.

[0049] The height dimension fluctuation of the lower cover within the tolerance range brings fluctuations to the assembly gap between the lower cover and the legs. Through the compensation action of the lower cover servo lifting mechanism, the height dimension fluctuation is eliminated, and the consistency of the assembly gap is maximally achieved. Furthermore, the consistency of the weld bead shrinkage amount and thermal deformation amount after welding is ensured. The height fluctuation of each leg on a single part is effectively controlled.

[0050] Third, since the positioning pin of the leg radial positioning mechanism has a function of retracting the pin. After welding is completed, the fixture loosens in the established order, and the positioning pin automatically retracts. When the fixture moves from the equipment welding area to the loading area, the workpiece and the fixture are completely separated, and there is no mutual force, so it can be easily removed. This avoids the disadvantages of difficult workpiece removal with traditional fixtures, even requiring the use of tools.

[0051] Compared with the prior art, the present invention has the following advantages:

[0052] 1. The automatic welding fixture for the compressor lower cover and legs provided by the present invention ensures the full effectiveness of each positioning surface through a safe and reliable fastening structure. The lower cover servo lifting mechanism ensures the consistency of the assembly gap between the lower cover and the legs, realizes the control of the height fluctuation of the legs after welding, and improves the quality.

[0053] 2. The automatic welding fixture for the compressor lower cover and legs provided by the present invention can conveniently increase and change the pre-installation position of the lower cover by combining the lower cover servo lifting mechanism with the PLC and the human-machine interface, improving the compatibility.

[0054] 3. The automatic welding fixture for the compressor lower cover and legs provided by the present invention increases the degree of automation and reduces the fatigue strength of the operator by using electrical components.

[0055] In summary, the technical solution of the present invention solves the problems in the prior art, such as large shrinkage during the welding of the outriggers, resulting in large fluctuations in the height of the outriggers after welding; tools are required for part picking after welding, increasing the difficulty of part picking; low compatibility, which is not conducive to quality management and production efficiency improvement. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0057] Figure 1 is a perspective view of the present invention;

[0058] Figure 2 is a front view of the present invention;

[0059] Figure 3 is a left view of the overall clamping part of the present invention;

[0060] Figure 4 is a front view of the overall clamping part of the present invention;

[0061] Figure 5 is a top view of the overall positioning part of the present invention;

[0062] Figure 6 is a structural schematic diagram of the outrigger clamping part of the present invention;

[0063] Figure 7 is a schematic diagram when detecting the top position of the lower cover of the present invention;

[0064] Figure 8 is a schematic diagram of the product processed using the present invention;

[0065] Figure 9 is a schematic diagram after assembling the lower cover and the outriggers using the present invention.

[0066] In the figure:

[0067] 1. Base 11. Mounting plate A 12. Frame 13. Upper mounting plate;

[0068] 2. Bottom plate;

[0069] 3. Lower cover end face positioning ring;

[0070] 4. Pneumatic chuck;

[0071] 5. Lower cover pressing cylinder 51. Pressing arm 52. Pressing head;

[0072] 6. Lower cover servo lifting mechanism 61. Servo electric cylinder 62. Mounting plate B 63. Guide shaft 64. Support frame;

[0073] 7. Leg positioning and fastening mechanism 71. Mounting frame A 72. Platform 73. Positioning pin 74. Cylinder 75. Side baffle 76. Plunger 77. Leg pressing cylinder 78. Pressing arm 79. Pressing block;

[0074] 8. Lower cover top position sensor 81. Probe 82. Guide rod cylinder 83. Position sensor 84. Mounting frame B;

[0075] 9. Lower cover;

[0076] 10. Leg. Specific implementation mode

[0077] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0078] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way restrictive of the present invention and its application or use. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0079] It should be noted that the terms used here are only for describing specific implementation modes and are not intended to limit the exemplary embodiments according to the present invention. As used here, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or their combinations.

[0080] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for the sake of convenience in description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be regarded as part of the authorized specification. In all the examples shown and discussed here, any specific values should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0081] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom" are generally based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description. Without contrary explanations, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and thus cannot be construed as limiting the protection scope of the present invention: the orientation words "inner, outer" refer to the inside and outside relative to the contour of each component itself.

[0082] For the convenience of description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "above" can be used here to describe the spatial positional relationship between a device or feature shown in the drawings and other devices or features. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation described in the drawings for the device. For example, if the device in the drawing is inverted, the device described as "above other devices or structures" or "over other devices or structures" will then be positioned "below other devices or structures" or "under other devices or structures". Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations are made for the spatial relative descriptions used here.

[0083] In addition, it should be noted that the use of words such as "first", "second" to limit components is only for the convenience of differentiating the corresponding components. Without separate statements, the above words have no special meanings, and thus cannot be construed as limiting the protection scope of the present invention.

[0084] As Figures 1-9As shown in the figure, the present invention provides an automatic fixture for welding the compressor lower cover and the support legs, which includes: a base 1, a bottom plate 2, a lower cover end face positioning ring 3, a pneumatic chuck 4, a lower cover pressing cylinder 5, a lower cover servo lifting mechanism 6, a support leg positioning and fastening mechanism 7, a lower cover top position sensor 8, a lower cover 9, a support leg 10, a PLC, and a human-machine interface; the bottom of the lower cover servo lifting mechanism 6 is installed on the base 1, and the top is connected to the bottom plate 2 installed in the middle of the upper part of the base 1;

[0085] The lower cover end face positioning ring 3 and the pneumatic chuck 4 are installed on the upper part of the bottom plate 2 to position the lower cover 9 placed on the bottom plate 2; the lower cover pressing cylinder 5 is installed on the side of the servo lifting mechanism 6 to press and fix the lower cover 9 placed on the bottom plate 2; there are 4 sets of support leg positioning and fastening mechanisms 7, which are evenly distributed on the upper periphery of the upper mounting plate 13 for positioning and fastening the support legs 10 to facilitate welding with the lower cover 9; the lower cover top displacement sensor 8 is fixedly installed on the ground or the fixed part of the equipment; the lower cover top position sensor 8 communicates with the PLC as a signal input end, and the lower cover servo lifting mechanism 6 communicates with the PLC as a signal receiving end.

[0086] As Figures 1-4 shown in the figure, the present invention provides a base 1, which includes: a mounting plate A11, a frame 12, and an upper mounting plate 13; the upper and lower parts of the frame 12 are respectively equipped with the upper mounting plate 13 and the mounting plate A11 to form a frame structure; the upper mounting plate 13 is a hollow plate-like structure.

[0087] As Figures 1-3 shown in the figure, the present invention provides a lower cover servo lifting mechanism 6, which includes: a servo electric cylinder 61, a mounting plate B62, a guide shaft 63, and a support frame 64; the lower end face of the cylinder body of the servo electric cylinder 61 is installed on the upper part of the mounting plate A11, and the cylinder rod is connected to the bottom of the mounting plate B62 to drive the mounting plate B62 to move in the vertical space, passing through the upper mounting plate 13 but not interacting with the upper mounting plate 13; the bottom of the support frame 64 is installed on the upper end face of the mounting plate B62, and the top is connected to the bottom of the bottom plate 2; there are at least two guide shafts 63, which are evenly distributed between the bottom plate 2 and the upper mounting plate 13. The guide shafts 63 are fixed to the lower surface of the bottom plate 2 through guide shaft seats, and their linear bearings are connected to the upper surface of the upper mounting plate 13 to ensure the smoothness and accuracy during lifting.

[0088] As Figures 1-4 shown in the figure, the present invention provides a lower cover pressing cylinder 5 installed on the side of the support frame 64; a pressing arm 51 is also installed on the lower cover pressing cylinder 5; a pressing head 52 is installed at the front end of the pressing arm 51; the pressing arm 51 drives the pressing head 52 to swing from the initial position to the upper side of the lower cover 9, and under the action of the pressing arm 51, the pressing head 52 presses the upper cover 9.

[0089] As Figures 1-6As shown in the figure, the present invention provides 4 sets of leg positioning and fastening mechanisms 7, which are evenly distributed around the upper periphery of the upper mounting plate 13. Each set of leg positioning and fastening mechanism 7 includes: mounting bracket A71, platform 72, positioning pin 73, cylinder 74, side baffle 75, plunger 76, leg pressing cylinder 77, pressing arm 78 and pressing block 79; the mounting bracket A71 is fixedly installed on the upper part of the upper mounting plate 13; the upper end face of the mounting bracket A71 is equipped with the platform 72; according to the radial distance requirements between the leg and the lower cover, positioning pins 73 are installed on each mounting surface of the platform 2; the cylinder block of the cylinder 74 is installed on the lower end face of the platform 72 through screws, and the piston rod passes through the platform 72 and is connected to the positioning pin 73, so as to realize the axial movement of the positioning pin 73; a side baffle 75 is installed on each side of the positioning pin 73; a plunger 76 is installed outside the positioning pin 73; under the combined action of the plunger 76 and the side baffle 75, the direction of the leg 10 can be restricted to point to the center of the lower cover 9; the leg pressing cylinder 77 is fixed on the side of the platform 72 through screws, a pressing arm 78 is installed on the leg pressing cylinder 77, and a pressing block 79 is installed at the lower part of the front end of the pressing arm 78; the leg pressing cylinder 77 swings from the initial position to directly above the leg 10, and finally presses the leg 10 through the pressing arm 78.

[0090] As Figure 1 , 7 shown in the figure, the lower cover top position sensor 8 includes: probe 81, guide rod cylinder 82, position sensor 83 and mounting bracket B84; the mounting bracket B84 is fixedly installed on the ground or the fixed part of the equipment; the guide rod cylinder 82 is installed on the mounting bracket B84, and the moving direction of its piston rod is consistent with the axial direction of the lower cover 9; the probe 81 is installed at the front end of the piston rod of the guide rod cylinder 82 and moves synchronously with the piston rod; a position sensor 83 is installed on the side of the guide rod cylinder 82, and the position sensor 83 can accurately detect the position of the piston ring in the guide rod cylinder 82, that is, the spatial position of the end face of the probe 81. The PLC can judge whether the fixture action is completed by confirming the cylinder position signal of the automatic positioning and fastening element. After confirming that the fixture action is completed, the lower cover top position sensor 8 is controlled to perform a detection action. The cylinder 82 moves from the initial position. The pressing head 52 provided on the lower cover pressing cylinder 5 is of a hollow type, and the probe 101 can pass through the through hole on the pressing head 52 and directly contact the upper cover. After contact, the probe 81 stops, and the sensor starts to detect the position of the piston ring in the cylinder, that is, the height position of the upper cover top. After the detection is completed, the sensor returns and transmits the result to the PLC. The PLC combines the difference between its coordinate value and the coordinate of the standard part to control the compensation movement of the lower cover servo lifting mechanism 6.

[0091] After the compensation is completed, the fixture moves to the welding area of the equipment through other action mechanisms (not related to this patent). After the welding is completed, when the fixture moves from the welding area to the loading area, the fixture automatically returns to its initial position. At the same time, the lower cover pressing cylinder 5 returns to its initial position, and the pneumatic chuck 4 moves radially towards the center of the circle to release the fastening of the lower cover; the leg pressing cylinder 77 returns to its initial position, and the cylinder 74 acts to drive the positioning pin 73 to retract, releasing the fastening of the leg. At this point, there is no longer any force between the lower cover assembly after the lower cover and the leg are welded and the fixture, and the operator can easily remove the workpiece. The retracting cylinder 84 can delay its return according to the PLC timing program, that is, when the fixture completely returns to its initial position, it is ready for the next workpiece assembly.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An automatic fixture for welding the lower cover of a compressor and the support legs, characterized in that, The automatic fixture for welding the compressor lower cover and the leg includes: a base (1), a bottom plate (2), a lower cover end face positioning ring (3), a pneumatic chuck (4), a lower cover pressing cylinder (5), a lower cover servo lifting mechanism (6), a leg positioning and fastening mechanism (7), a lower cover top position sensor (8), a lower cover (9), a leg (10), a PLC, and a human-machine interface; The base (1) includes: a mounting plate A (11), a frame (12), and an upper mounting plate (13); the upper and lower parts of the frame (12) are respectively equipped with the upper mounting plate (13) and the mounting plate A (11) to form a frame structure; the upper mounting plate (13) is a hollow plate-like structure; The bottom of the lower cover servo lifting mechanism (6) is installed on the upper part of the mounting plate A (11), and the top is connected to the bottom plate (2) installed in the middle of the upper part of the base (1); The lower cover end face positioning ring (3) and the pneumatic chuck (4) are installed on the upper part of the bottom plate (2) to position the lower cover (9) placed on the bottom plate (2); The lower cover pressing cylinder (5) is installed on the side of the servo lifting mechanism (6) to press and fix the lower cover (9) placed on the bottom plate (2); There are 4 sets of the leg positioning and fastening mechanisms (7), which are evenly distributed on the upper periphery of the upper mounting plate (13) for positioning and fastening the legs (10) to facilitate welding with the lower cover (9); each set of the leg positioning and fastening mechanism (7) includes: a mounting frame A (71), a platform (72), a positioning pin (73), a cylinder (74), a side baffle (75), a plunger (76), a leg pressing cylinder (77), a pressing arm II (78), and a pressing block (79); the mounting frame A (71) is fixedly installed on the upper part of the upper mounting plate (13); the upper end face of the mounting frame A (71) is equipped with the platform (72); according to the radial distance requirements between the legs and the lower cover, the positioning pins (73) are installed on each mounting surface of the platform (72); The lower cover top position sensor (8) is fixedly installed on the ground or the fixed part of the equipment; The lower cover top position sensor (8) communicates with the PLC as a signal input end, and the lower cover servo lifting mechanism (6) communicates with the PLC as a signal receiving end.

2. The automatic welding fixture for the compressor lower cover and support legs according to claim 1 is characterized in that: The lower cover servo lifting mechanism (6) includes: a servo electric cylinder (61), a mounting plate B (62), a guide shaft (63), and a support frame (64); The lower end face of the cylinder body of the servo electric cylinder (61) is installed on the upper part of the mounting plate A (11), and the cylinder rod is connected to the bottom of the mounting plate B (62) to drive the mounting plate B (62) to move in the vertical space, passing through the upper mounting plate (13) but not interacting with the upper mounting plate (13); The bottom of the support frame (64) is installed on the upper end face of the mounting plate B (62), and the top is connected to the bottom of the bottom plate (2); There are at least two guide shafts (63), which are evenly distributed between the bottom plate (2) and the upper mounting plate (13). The guide shafts (63) are fixed to the lower surface of the bottom plate (2) through guide shaft seats, and their linear bearings are connected to the upper surface of the upper mounting plate (13) to ensure the smoothness and accuracy during lifting.

3. The automatic welding fixture for the compressor lower cover and support legs according to claim 1 is characterized in that: The described lower cover pressing cylinder (5) is installed on the side of the support frame (64); a first pressing arm (51) is also installed on the lower cover pressing cylinder (5); a pressing head (52) is installed at the front end of the first pressing arm (51); the first pressing arm (51) drives the pressing head (52) to swing from the initial position to above the lower cover (9), and under the action of the first pressing arm (51), the pressing head (52) presses the lower cover (9).

4. The automatic welding fixture for the compressor lower cover and support legs according to claim 1 is characterized in that , The cylinder block of the described cylinder (74) is installed on the lower end face of the platform (72) through screws, and the piston rod passes through the platform (72) and is connected to the positioning pin (73), so as to realize that the positioning pin (73) can move along its axial direction; A side baffle (75) is installed on each side of the described positioning pin (73); A plunger (76) is installed outside the described positioning pin (73); Under the combined action of the described plunger (76) and the side baffle (75), the direction of the leg (10) can be restricted so that it points to the center of the lower cover (9); The described leg pressing cylinder (77) is fixed on the side of the platform (72) through screws. A second pressing arm (78) is installed on the leg pressing cylinder (77), and a pressing block (79) is installed at the lower part of the front end of the second pressing arm (78); the leg pressing cylinder (77) swings from the initial position to directly above the leg (10), and finally presses the leg (10) through the second pressing arm (78) driving the pressing block (79).

5. The automatic fixture for welding the compressor lower cover and the support leg according to claim 1, wherein The described lower cover top position sensor (8) includes: a probe (81), a guide rod cylinder (82), a position sensor (83), and a mounting bracket B (84); The described mounting bracket B (84) is fixedly installed on the ground or the fixed part of the equipment; The described guide rod cylinder (82) is installed on the mounting bracket B (84), and the moving direction of its piston rod is consistent with the axial direction of the lower cover (9); The described probe (81) is installed at the front end of the piston rod of the guide rod cylinder (82) and moves synchronously with the piston rod; A position sensor (83) is installed on the side of the described guide rod cylinder (82), and the position sensor (83) can accurately detect the position of the piston ring in the guide rod cylinder (82), that is, the spatial position of the end face of the probe (81).

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