A method for machining a contact with bilateral grooving

Abstract

The present invention relates to a method for processing a contact with bilateral grooving. The method comprises the following steps: S1: performing cutting processing on one end of a contact cup to be processed by using a face milling cutter method to obtain a single-end contact cup with a grooving corner of 120 degrees at one end; S2: performing cutting processing on the other end of the single-end contact cup by using a face milling cutter method to obtain a double-end contact cup with grooving corners of 120 degrees at both ends; wherein, the grooves at both ends of the double-end contact cup are non-through, and the projections of the grooves at both ends of the double-end contact cup in the vertical direction intersect; S3: performing cutting on the other end of the double-end contact cup by using a turning method, and the cutting plane is parallel to one end plane of the double-end contact cup to obtain a finished contact cup with a grooving corner of 240 degrees. The method of the present invention not only ensures the miniaturization of the contact cup, but also can significantly improve the magnetic field intensity of the cup-shaped contact cup and improve its ability to break the current, belonging to the technical field of vacuum interrupters.

Description

Technical Field

[0001] The present invention relates to the technical field of vacuum interrupters, and particularly relates to a method for machining a contact with double-sided grooving. Background Art

[0002] Generally, in order to ensure the breaking capacity of a vacuum interrupter, the cup-shaped longitudinal magnetic contact cup technology is adopted to control the arc. To meet the working conditions of large breaking current and large rated current, it is necessary to increase the corner angle of the cup-shaped contact structure to enhance the longitudinal magnetic field.

[0003] Currently, the cup-shaped contact structures are all machined by a face milling cutter. Limited by the current machining technology, the corner angle of the cup-shaped contact cup machined by the face milling cutter cannot exceed 120 degrees. Its longitudinal magnetic field strength is relatively small, and the ability to control the arc is weak. Only by increasing the size of the contact cup and increasing the arc ablation area can its breaking current capacity be enhanced.

[0004] The cup-shaped contact machined by an end milling cutter can achieve a large corner angle of 240 degrees and above. However, considering that the aspect ratio required for the cutting stress of the end milling cutter is greater than 5:1, its grooving width is at least 5 mm, and the wall thickness of the corresponding contact cup should be more than 25 mm. The size of the contact cup is too large and too thick. This solution is not conducive to the miniaturization of the contact. Summary of the Invention

[0005] Aiming at the technical problems existing in the prior art, the object of the present invention is to provide a method for machining a contact with double-sided grooving, which solves the problems that the longitudinal magnetic field strength of the existing contact cup is relatively small, the ability to control the arc is weak, or the size of the contact cup is too large and too thick.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for machining a contact with double-sided grooving, the method comprising the following steps: S1: Performing cutting on one end of a contact cup to be machined by a face milling cutter machining method to obtain a single-end contact cup with a grooving corner angle of 120 degrees at one end; S2: Performing cutting on the other end of the single-end contact cup by a face milling cutter machining method to obtain a double-end contact cup with grooving corner angles of 120 degrees at both ends; wherein, the grooves at both ends of the double-end contact cup are not through, and the projections of the grooves at both ends of the double-end contact cup in the vertical direction intersect; S3: Performing cutting on the other end of the double-end contact cup by a turning machining method, and the cutting plane is parallel to one end plane of the double-end contact cup to obtain a finished contact cup with a grooving corner angle of 240 degrees.

[0008] As a preference, in step S1, the contact cup to be machined is a cylindrical longitudinal magnetic contact cup, the contact cup to be machined has a closed end and an open end, the open end is the cup mouth of the contact cup to be machined, and the closed end is provided with a central hole penetrating the closed end.

[0009] As a preference, before the machining of the contact cup to be processed in step S1, the following pretreatment steps are carried out first. a1: Pass a bolt through the central hole of the contact cup to be processed, and lock the contact cup to be processed on the bolt with a nut. b1: Set the cup mouth of the contact cup to be processed facing the face milling cutter, and adjust the inclination angle of the contact cup to be processed relative to the face milling cutter to determine the feed direction of the face milling cutter. c1: Install a three-jaw chuck on the milling machine, and fix the bolt through the three-jaw chuck, so that the contact cup to be processed is fixed, and the groove cutting inclination angle of the contact cup to be processed is determined. d1: Start the milling machine to make the face milling cutter rotate and machine the contact cup to be processed.

[0010] As a preference, the number of feed points at the cup mouth of the contact cup to be processed is two, and the included angle between the two feed points is 90 degrees. After the pretreatment steps of the contact cup to be processed are completed, the face milling cutter machining method is as follows: d11: The face milling cutter feeds from one feed point of the contact cup to be processed, feeds along the axis direction of the contact cup to be processed for cutting, and after cutting to the cutting end point, the face milling cutter retracts along the reverse direction of the feed. d12: Rotate the contact cup to be processed by 90 degrees, feed from the other feed point and repeat the machining process of step d11 to complete the cutting of the contact cup to be processed, and obtain a single-end contact cup with a groove cutting corner of 120 degrees at one end.

[0011] As a preference, before the machining of the single-end contact cup in step S2, the following pretreatment steps are carried out first. a2: Pass a bolt through the central hole of the single-end contact cup, and lock the single-end contact cup on the bolt with a nut. b2: Set the cup mouth of the single-end contact cup facing away from the face milling cutter, and adjust the inclination angle of the single-end contact cup relative to the face milling cutter to determine the feed direction of the face milling cutter. c2: Install a three-jaw chuck on the milling machine, and fix the bolt through the three-jaw chuck, so that the single-end contact cup is fixed, and the groove cutting inclination angle of the single-end contact cup is determined. d2: Start the milling machine to make the face milling cutter rotate and machine the single-end contact cup.

[0012] As a preference, the number of feed points at the closed end of the single-end contact cup is two, and the included angle between the two feed points is 90 degrees. After the pretreatment steps of the single-end contact cup are completed, the face milling cutter machining method is as follows: d21: The face milling cutter feeds from one feed point of the single-end contact cup, feeds along the axis direction of the single-end contact cup for cutting, and after cutting to the cutting end point, the face milling cutter retracts along the reverse direction of the feed. d22: Rotate the single-end contact cup by 90 degrees, feed from the other feed point and repeat the machining process of step d21 to complete the cutting of the single-end contact cup, and obtain a double-end contact cup with groove cutting corners of 120 degrees at both ends.

[0013] As a preference, in step S3, the closed end of the double-end contact cup is turned on a lathe, and the lathe turns along the radial direction of the double-end contact cup to obtain a finished contact cup with a groove cutting corner of 240 degrees.

[0014] As an optimization, with the center of the finished contact cup as the center of the circle, the included angle between each feed point and its corresponding cutting end point in the vertical projection direction is 120 degrees.

[0015] As an optimization, the wall thickness of the finished contact cup with a grooving corner of 240 degrees does not exceed 10 mm, and the width of the groove does not exceed 3 mm.

[0016] As an optimization, the thickness of the groove block of the face milling cutter does not exceed 3 mm.

[0017] Generally speaking, the present invention has the following advantages:

[0018] 1. The method of the present invention solves the difficulty that the corner of the groove cut by the face milling cutter for the contact cannot be increased. Through the processing method of the face milling cutter with grooves at both ends, the effect of a large corner groove of 240 degrees that can only be achieved by a vertical milling cutter is realized, and its magnetic field strength is significantly enhanced compared with the 120-degree corner.

[0019] 2. The method of the present invention solves the size problem of the contact. Through the processing with face milling cutters at both ends, it not only avoids the long diameter ratio of the vertical milling cutter required for cutting stress being greater than 5:1, realizing the reduction of the contact size; but also avoids the situation where the contact size is enlarged to meet the breaking capacity when the groove corner ≤ 120°, realizing the reduction of the contact size. At the same time, the processing efficiency is high, and the groove can reach a corner of 240 degrees. Therefore, overall, this processing technology is more economical and practical, and problems such as tool clamping and tool breakage of the vertical milling cutter will not occur. Description of the Drawings

[0020] Figure 1 It is a schematic diagram of the contact cup fixed on a three-jaw chuck with the cup mouth facing the face milling cutter.

[0021] Figure 2 It is a schematic diagram of the contact cup during face milling cutter processing.

[0022] Figure 3 It is a schematic diagram of the contact cup fixed on a three-jaw chuck with the cup mouth facing away from the face milling cutter.

[0023] Figure 4 It is the front view of a single-end contact cup.

[0024] Figure 5 It is another front view of a single-end contact cup.

[0025] Figure 6 It is the front view of a double-end contact cup.

[0026] Figure 7 It is the front view of the finished contact cup.

[0027] Figure 8 It is the three-dimensional view of the finished contact cup.

[0028] Figure 9 Schematic diagram of the angle between the distance of the groove cut on the horizontal projection and the root of the groove.

[0029] Figure 10 Magnetic field variation diagram of the finished contact cup at a 120-degree corner.

[0030] Figure 11 Magnetic field variation diagram of the finished contact cup at a 240-degree corner, Δy = 0 degree, Δx = 3 mm.

[0031] Figure 12 Magnetic field variation diagram of the finished contact cup at a 240-degree corner, Δy = 45 degrees, Δx = 1 mm.

[0032] Figure 13 Magnetic field variation diagram of the finished contact cup at a 240-degree corner, Δy = 45 degrees, Δx = 5 mm.

[0033] Among them, Δx is the distance of the groove cut on the horizontal projection, Δy is the angle between the roots of the grooves, that is, the distance deviation in the xy direction of two non-connected grooves, X refers to the coordinate change along the diameter direction of the contact, and Y refers to the longitudinal magnetic field intensity (T).

[0034] 1 is the contact cup, 2 is the cup mouth of the contact cup, 3 is the closed end of the contact cup, 4 is the inclined groove, 5 is the central hole, A is the cutting end point, and B is the feed point. Specific implementation manner

[0035] The present invention will be further described in detail below in conjunction with specific implementation manners.

[0036] A method for processing a contact with double-sided grooves, the method includes the following steps: S1: Using a face milling cutter processing method to cut one end of the contact cup to be processed, obtaining a single-end contact cup with a groove corner of 120 degrees at one end; S2: Using a face milling cutter processing method to cut the other end of the single-end contact cup, obtaining a double-end contact cup with groove corners of 120 degrees at both ends; wherein, the grooves at both ends of the double-end contact cup are non-through settings, and the projections of the grooves at both ends of the double-end contact cup intersect in the vertical direction; S3: Using a turning processing method to cut the other end of the double-end contact cup, and the cutting plane is parallel to one end plane of the double-end contact cup, obtaining a finished contact cup with a groove corner of 240 degrees.

[0037] In step S1, the contact cup to be processed is a cylindrical longitudinal magnetic contact cup, the contact cup to be processed has a closed end and an open end, the open end is the cup mouth of the contact cup to be processed, and the closed end is provided with a central hole penetrating the closed end.

[0038] In step S1, before the contact cup to be processed undergoes cutting, the following preprocessing steps are carried out first. a1: Pass a bolt through the central hole of the contact cup to be processed and lock the contact cup to be processed on the bolt with a nut. b1: Set the cup mouth of the contact cup to be processed facing the face milling cutter, and adjust the inclination angle of the contact cup to be processed relative to the face milling cutter to determine the feed direction of the face milling cutter. c1: Install a three-jaw chuck on the milling machine, and fix the bolt through the three-jaw chuck, so that the contact cup to be processed is fixed, and the slot inclination angle of the contact cup to be processed is determined. d1: Start the milling machine to make the face milling cutter rotate and perform cutting on the contact cup to be processed.

[0039] The number of feed points at the cup mouth of the contact cup to be processed is two, and the included angle between the two feed points is 90 degrees. After completing the preprocessing steps of the contact cup to be processed, the face milling cutter processing method is as follows: d11: The face milling cutter feeds from one feed point of the contact cup to be processed, feeds along the axis direction of the contact cup to be processed for cutting, and after cutting to the cutting end point, the face milling cutter retracts in the reverse direction of the feed. d12: Rotate the contact cup to be processed by 90 degrees, feed from the other feed point and repeat the processing process of step d11 to complete the cutting of the contact cup to be processed, and obtain a single-end contact cup with a slot corner of 120 degrees at one end.

[0040] In step S2, before the single-end contact cup undergoes cutting, the following preprocessing steps are carried out first. a2: Pass a bolt through the central hole of the single-end contact cup and lock the single-end contact cup on the bolt with a nut. b2: Set the cup mouth of the single-end contact cup facing away from the face milling cutter, and adjust the inclination angle of the single-end contact cup relative to the face milling cutter to determine the feed direction of the face milling cutter. c2: Install a three-jaw chuck on the milling machine, and fix the bolt through the three-jaw chuck, so that the single-end contact cup is fixed, and the slot inclination angle of the single-end contact cup is determined. d2: Start the milling machine to make the face milling cutter rotate and perform cutting on the single-end contact cup.

[0041] The number of feed points at the closed end of the single-end contact cup is two, and the included angle between the two feed points is 90 degrees. After completing the preprocessing steps of the single-end contact cup, the face milling cutter processing method is as follows: d21: The face milling cutter feeds from one feed point of the single-end contact cup, feeds along the axis direction of the single-end contact cup for cutting, and after cutting to the cutting end point, the face milling cutter retracts in the reverse direction of the feed. d22: Rotate the single-end contact cup by 90 degrees, feed from the other feed point and repeat the processing process of step d21 to complete the cutting of the single-end contact cup, and obtain a double-end contact cup with slot corners of 120 degrees at both ends.

[0042] In step S3, the closed end of the double-end contact cup is turned on a lathe, and the lathe turns along the radial direction of the double-end contact cup to obtain a finished contact cup with a slot corner of 240 degrees.

[0043] With the center of the finished contact cup as the center of the circle, the included angle between each feed point and its corresponding cutting end point in the vertical projection direction is 120 degrees.

[0044] The wall thickness of the finished contact cup with a grooving corner of 240 degrees does not exceed 10 mm, and the width of the grooving does not exceed 3 mm.

[0045] The thickness of the groove block of the face milling cutter does not exceed 3 mm.

[0046] In this embodiment, a method for machining contacts with double-sided grooving is specifically applied as follows:

[0047] 1. Adopt face milling cutter machining technology. First, fix the contact cup to be machined by clamping with bolts and nuts through the central hole of the contact cup to be machined on the milling machine (such as Figure 1 ).

[0048] 2. Then adjust the inclination angle of the contact cup to determine the feed direction, and then fix the three-jaw chuck, so as to determine the grooving inclination. Prepare to start the milling machine, make the face milling cutter rotate, and start cutting the part (contact cup to be machined).

[0049] 3. The face milling cutter feeds from the R / 2 position (feed point) at point B of the contact cup to be machined, and feeds parallel and inwards along the Y axis of the contact ( Figure 2 dotted line) direction (as shown by the Figure 2 arrow) for cutting. During the feeding process, the contact cup remains stationary, and the face milling cutter only retains the movement in the Y axis direction, and the speeds in other directions are 0. The feed amount is the radius R. The face milling cutter reaches point A along the Y axis. After the cutting face milling cutter reaches point A, it retracts along the reverse direction of the feed. Finally, the included angle formed by AB and the center of the circle is 120 degrees, which is also called the grooving corner of the contact cup to be machined is 120 degrees. After completing the above method, rotate the contact cup to be machined by 90 degrees and repeat this process again. Thus, the grooving of the first 120-degree corner of the cup mouth of the contact cup to be machined is processed.

[0050] 4. After completing the grooving of the first 120-degree corner, flip the single-end contact cup, repeat the clamping method in step 1, and still fix it by bolts and nuts through its central hole, so that step three can be repeated to cut the closed end of the single-end contact cup and cut another 120-degree corner grooving, as shown in Figure 3 .

[0051] 5. Repeat the machining method in step 4, feed from point B, and feed inwards along the contact axis ( Figure 2 dotted line) direction (as shown by the Figure 2 arrow) for cutting. After the cutting face milling cutter reaches point A, it retracts along the reverse direction of the feed. Finally, the included angle formed by AB and the center of the circle is 120 degrees. This grooving intersects with the grooving in step three, but does not penetrate (please see specifically Figures 5-6), thus ensuring that the middle of the grooving is not suspended, and at the same time, a certain amount of oxygen-free copper is retained to play a supporting role, greatly improving the mechanical properties of cutting, and preventing deformation and tool breakage. The front view and left view of the cutting are as shown in Figure 5 、 6 .

[0052] 6. After processing, as shown in Figures 5-6 , both sides of the contact cup are grooved, and the groove corners are all 120 degrees. At the same time, the grooves at both ends of the contact cup cannot penetrate, and oxygen-free copper material is kept in the middle to play a supporting role, avoiding suspension, effectively improving the strength and avoiding deformation problems during cutting.

[0053] 7. Through turning processing technology, along the Figure 7 axis direction, the closed end part of the contact cup is turned to obtain a new plane for the contact cup, while meeting the requirement of a 240° rotation angle of the contact cup.

[0054] 8. The contact cup is grooved from both sides, each cut by 120° (see Figure 8 ), thus solving the strength problem of the contact cup. There is no need to use an end mill to process it, and its size and structure can be the same as those of a conventional 120° contact cup, without the need to separately increase the size. The connection at the root of the two grooves is as shown in Figure 8 . The size of the connection can be adjusted, and the crossing angle (see Figure 9 ), so as to achieve forced current shunting under this contact cup and realize the function of a large-angle contact.

[0055] As shown in Figures 10-13 , the x coordinate represents the coordinate change along the contact diameter direction, and the y coordinate represents the magnitude of the longitudinal magnetic field strength (unit: T) changing with the x coordinate. The closer to the contact center, the greater the longitudinal magnetic field strength, and the closer to the contact edge, the smaller the longitudinal magnetic field strength. Figures 10-13 It shows that the longitudinal magnetic field strength at the contact center is significantly enhanced for the case of bilateral grooving of 240 degrees compared with that of a 120-degree rotation angle. Such as the magnetic field situation of a 120-degree rotation angle; the magnetic field situation of a 240-degree rotation angle with Δy = 0 degrees and Δx = 3 mm; the magnetic field situation of a 240-degree rotation angle with Δy = 45 degrees and Δx = 1 mm; the magnetic field situation of a 240-degree rotation angle with Δy = 45 degrees and Δx = 5 mm. The details are as follows in the table.

[0056]

[0057]

[0058] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A method for processing a contact with bilateral grooving, characterized in that The method includes the following steps: S1: Use a face milling cutter machining method to cut one end of the workpiece contact cup to obtain a single-end contact cup with a 120-degree cut groove corner at one end; S2: Use a face milling cutter machining method to cut the other end of the single-end contact cup to obtain a double-end contact cup with 120-degree cut groove corners at both ends; wherein, the cut grooves at both ends of the double-end contact cup are non-through settings, and the projections of the cut grooves at both ends of the double-end contact cup in the vertical direction intersect; S3: Use a turning machining method to cut the other end of the double-end contact cup, and the cutting plane is parallel to one end plane of the double-end contact cup to obtain a finished contact cup with a 240-degree cut groove corner; In step S1, the workpiece contact cup is a cylindrical longitudinal magnetic contact cup. The workpiece contact cup has a closed end and an open end. The open end is the cup mouth of the workpiece contact cup, and the closed end is provided with a central hole penetrating the closed end; In step S1, before the workpiece contact cup is subjected to cutting machining, the following pretreatment steps are first carried out, a1: Pass a bolt through the central hole of the workpiece contact cup and lock the workpiece contact cup on the bolt with a nut; b1: Set the cup mouth of the workpiece contact cup facing the face milling cutter, and adjust the inclination angle of the workpiece contact cup relative to the face milling cutter to determine the feed direction of the face milling cutter; c1: Install a three-jaw chuck on the milling machine, and fix the bolt through the three-jaw chuck, so that the workpiece contact cup is fixed, and the cut groove inclination angle of the workpiece contact cup is determined; d1: Start the milling machine, make the face milling cutter rotate, and machine the workpiece contact cup; The number of feed points at the cup mouth of the workpiece contact cup is two, and the included angle between the two feed points is 90 degrees; after the pretreatment steps of the workpiece contact cup are completed, the face milling cutter machining method is: d11: The face milling cutter feeds from one feed point of the workpiece contact cup, feeds along the axis direction of the workpiece contact cup for cutting, and after cutting to the cutting end point, the face milling cutter retracts along the reverse direction of the feed; d12: Rotate the workpiece contact cup by 90 degrees, feed from the other feed point and repeat the machining process of step d11 to complete the cutting machining of the workpiece contact cup to obtain a single-end contact cup with a 120-degree cut groove corner at one end; In step S2, before the single-end contact cup is subjected to cutting machining, the following pretreatment steps are first carried out, a2: Pass a bolt through the central hole of the single-end contact cup and lock the single-end contact cup on the bolt with a nut; b2: Set the cup mouth of the single-end contact cup facing away from the face milling cutter, and adjust the inclination angle of the single-end contact cup relative to the face milling cutter to determine the feed direction of the face milling cutter; c2: Install a three-jaw chuck on the milling machine, and fix the bolt through the three-jaw chuck, so that the single-end contact cup is fixed, and the cut groove inclination angle of the single-end contact cup is determined; d2: Start the milling machine, make the face milling cutter rotate, and machine the single-end contact cup.

2. A method for machining a contact with bilateral grooving according to claim 1, characterized in that: The number of feed points at the closed end of the single-end contact cup is two, and the included angle between the two feed points is 90 degrees; after the pretreatment steps of the single-end contact cup are completed, the face milling cutter machining method is: d21: The face mill cutter feeds from one feed point of the single-ended contact cup, feeds along the axial direction of the single-ended contact cup for cutting, and after cutting to the cutting end point, the face mill cutter retracts in the reverse direction of the feed; d22: Rotate the single-ended contact cup by 90 degrees, feed from another feed point and repeat the processing flow of step d21 to complete the cutting process of the single-ended contact cup, and obtain a double-ended contact cup with both end cut groove corners of 120 degrees.

3. A method for machining a contact with bilateral grooving according to claim 2, characterized in that: In step S3, the closed end of the double-ended contact cup is turned by a lathe, and the lathe turns along the radial direction of the double-ended contact cup to obtain a finished contact cup with a cut groove corner of 240 degrees.

4. A method for processing a contact with bilateral grooving according to claim 3, characterized in that: Taking the center of the finished contact cup as the center of the circle, the included angle between each feed point and its corresponding cutting end point in the vertical projection direction is 120 degrees.

5. A method for machining a contact with bilateral grooving according to claim 4, characterized in that: The wall thickness of the finished contact cup with a cut groove corner of 240 degrees does not exceed 10 mm, and the width of the cut groove does not exceed 3 mm.

6. A method for machining a contact with bilateral grooving according to claim 5, characterized in that: The thickness of the groove block of the face mill cutter does not exceed 3 mm.

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