A processing method for positioning countersinks inside deep holes of a mold

Abstract

The present invention discloses a processing method for a positioning countersunk head inside a deep hole of a mold, comprising the following steps: setting a reference; using a CNC machining group to perform a first machining along the X direction according to a set first depth until the machining of the S2 hole and the preliminary machining of the S1 hole are completed; using the CNC machining group to perform a second machining along the X direction according to a set second depth until the machining of the S1 hole is completed; using the CNC machining group to complete the machining of a lateral groove along the Y direction according to a set third depth; using an electric discharge machining group to extend an electric discharge electrode into the lateral groove to perform electric discharge machining on one end of the S2 hole facing the lateral groove until the machining of the positioning countersunk head is completed. It solves the problems in the prior art that a single deep hole drill cannot machine the required positioning countersunk head, and that there are problems such as insufficient stroke or inconvenient machining in a single electric discharge machining.

Description

Technical Field

[0001] The present invention relates to the technical field of mold production and processing, and particularly relates to a processing method for a positioning counterbore in a deep hole of a mold. Background Art

[0002] When designing existing die-casting molds considering structure and forming requirements, due to the particularity of die-casting molds, specifically, extrusion pins or lateral pins are used when producing products with die-casting molds. Before ejecting the product, the extrusion pins or lateral pins are retracted. Since the extrusion pins or lateral pins and the product are not in the same direction for demolding on the mold, if not retracted, the extrusion pins or lateral pins will hold the demolded product and form an undercut. Therefore, the extrusion pins or lateral pins are movably arranged, and the movement will cause the holes on the mold to be easily worn. In order to reduce the wear of the inner holes of the mold, protective sleeves are used. However, there will be an angular deviation between the top surface of the protective sleeve installed on the mold and the product surface. It is necessary to machine the top surface of the protective sleeve to be consistent with the angle of the mold and position the protective sleeve to prevent it from rotating when the extrusion pin or lateral pin moves. This positioning method is to design a positioning surface in the hole for positioning with the sleeve, that is, a positioning counterbore needs to be machined in the hole. In order to prevent the positioning sleeve from being easily deformed, the positioning sleeve is generally designed to be as short as possible in length. As Figure 1 and Figure 2 shown is the mold described in the present application. A hole for installing a positioning sleeve needs to be machined on the mold. The hole is characterized by being a deep hole 14 with a depth of approximately 1 m and including a large-diameter section and a small-diameter section. For the convenience of description and distinction, the large-diameter section is described as the S1 hole 41, and the small-diameter section is described as the S2 hole 142. The S1 hole 141 and the S2 hole 142 are coaxially arranged. A positioning counterbore 143 needs to be machined at one end of the S2 hole 142 facing the S1 hole 141 to fix the positioning sleeve (not shown) to prevent it from rotating when the extrusion pin or lateral pin moves. The characteristics of the positioning counterbore 143 are as Figure 5 and Figure 6 shown. It is not a circular hole, but has a wall surface that is a plane 144. One end of the S2 hole 142 facing away from the S1 hole 141, that is, the hole opening 1421 of the S2 hole 142, corresponds to the small end of the positioning sleeve. The S1 hole 141 corresponds to the large end of the positioning sleeve, and one end of the S1 hole 141 facing the S2 hole 142 corresponds to the large-end tail of the positioning sleeve. The outside of the S2 hole 142, that is, the left concave area shown in Figure 3 is the product forming area 20. The hole opening 1411 of the S1 hole 141, that is, as shown in Figure 3The right end of the S1 hole 131 shown penetrates through the outer wall of the mold 10, that is, the hole opening 1411 is on the outer wall of the mold 10. The way to machine this hole is to start machining from the hole opening 1411 of the S1 hole 141 and machine in the direction towards the S2 hole 142. Since the small end face of the positioning sleeve is flush with the product forming area 20, the distance from the large end tail of the positioning sleeve to the product forming area 20 on the mold 10 is reduced, resulting in Figure 3 the distance from the hole opening 1411 of the S1 hole 141 to the positioning counterbore 143 becoming deeper as shown, and the positioning counterbore 143 is approximately 600 mm away from the hole opening 1411 of the S1 hole 141.

[0003] In the prior art, the machining method for deep holes generally uses deep hole drilling equipment, but deep hole drills cannot machine the positioning counterbore with the above structural features. Currently, the equipment that can match the machining of the positioning counterbore with this structural feature is an electric discharge machine, but the stroke of the existing electric discharge machines on the market is not enough. Although some strokes can be achieved, the problem is that the electrode used for machining is too long and prone to deformation, resulting in poor machining effects or problems such as inability to perform electrical discharge machining. Therefore, in order to solve the above problems, the present invention is hereby proposed. Summary of the Invention

[0004] Aiming at at least one of the above existing technical problems, the object of the present invention is to provide a machining method for a positioning counterbore in a deep hole of a mold.

[0005] The technical solution of the present invention is as follows:

[0006] An object of the present invention is to provide a machining method for a positioning counterbore in a deep hole of a mold, including the following steps:

[0007] Set a reference. Let the side where the hole opening of the S1 hole is located be the first surface, the wall surface where the hole opening of the S2 hole is located be the second surface, the side adjacent to both the first surface and the second surface and closer to the deep hole to be machined be the third surface, the direction parallel to the axis of the deep hole to be machined be the X direction, and the direction along the first surface be the Y direction;

[0008] Use a CNC machining group to take the hole opening position of the S1 hole on the first surface as the machining starting point, and perform the first machining along the X direction according to a set first depth until the machining of the S2 hole and the preliminary machining of the S1 hole are completed;

[0009] Use a CNC machining group to take the hole opening of the S1 hole on the first surface as the machining starting point, and perform the second machining along the X direction according to a set second depth until the machining of the S1 hole is completed. Among them, the drilling head used by the CNC machining group during the second machining is thicker than the drilling head used during the first machining, and the second depth is shallower than the first depth;

[0010] Use the CNC machining group to take the notch position of the lateral groove on the third surface as the machining starting point, and complete the machining of the lateral groove along the Y direction according to the set third depth;

[0011] Use the electrical discharge machining group to insert the electrical discharge electrode into the lateral groove to perform electrical discharge machining on one end of the S2 hole facing the lateral groove until the machining of the locating counterbore is completed, where the shape of the electrical discharge electrode matches the shape of the locating counterbore.

[0012] Compared with the prior art, the advantages of the present invention are:

[0013] A method for machining a locating counterbore in a deep hole of a mold according to the present invention, according to the depth of the deep hole and the characteristics of the locating counterbore, selects to add a lateral groove on the side of the mold, the lateral groove vertically penetrates into the deep hole, and the electrical discharge machining equipment is placed through the lateral groove, and the required locating counterbore is machined by electrical discharge. The machining method is simple and reliable, and solves the problems that a single deep hole drill in the prior art cannot machine the required locating counterbore and the single electrical discharge machining has insufficient stroke or inconvenient machining. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be further described below in conjunction with the drawings and embodiments:

[0015] Figure 1 It is a three-dimensional structure schematic diagram of an angle of the mold (with an electrical discharge machining group provided on the mold) according to an embodiment of the present invention;

[0016] Figure 2 It is a three-dimensional structure schematic diagram of another angle of the mold (with an electrical discharge machining group provided on the mold) according to an embodiment of the present invention;

[0017] Figure 3 It is a sectional structure schematic diagram of the mold according to an embodiment of the present invention along a line parallel to the center connection line of two deep holes;

[0018] Figure 4 It is a front view structure schematic diagram of the mold (with an electrical discharge machining group provided on the mold) according to an embodiment of the present invention;

[0019] Figure 5 For Figure 4 It is a sectional structure schematic diagram of the mold with the electrical discharge machining group omitted in the A-A direction;

[0020] Figure 6 For Figure 5 It is a partial enlarged structure schematic diagram of part B in;

[0021] Figure 7 For Figure 4 It is a sectional structure schematic diagram in the A-A direction in;

[0022] Figure 8Schematic three-dimensional structure diagram of the electric discharge machining group for positioning countersunk head machining in deep holes in the embodiments of the present invention;

[0023] Figure 9 is Figure 8 Schematic structure diagram of the discharge electrode of the electric discharge machining group in

[0024] Wherein: 10, mold; 11, first surface; 12, second surface; 13, third surface; 14, deep hole; 141, S1 hole; 142, S2 hole; 143, positioning countersunk head; 144, first plane; 15, side groove; 20, product forming area; 30, electric discharge machining group; 31, electric discharge machine; 32, fixing rod; 321, notch; 33, clamping tooling; 34, discharge electrode; 341, electrode body; 342, machining part; 343, second plane; 344, connection hole. Specific embodiments

[0025] To make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In addition, in the following description, the descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0026] Refer to Figures 1 to 9 , the processing method for positioning countersunk head in the deep hole of the mold in the embodiments of the present invention includes the following steps:

[0027] Set the reference, let the side where the orifice of the S1 hole 141 is located be the first surface 11, the wall surface where the orifice of the S2 hole 142 is located be the second surface 12, the side that is adjacent to both the first surface 11 and the second surface 12 and is closer to the deep hole 14 to be machined be the third surface 13, the direction parallel to the axis of the deep hole 14 to be machined be the X direction, and the direction parallel to the first surface 11 be the Y direction;

[0028] Use the CNC machining group to take the orifice position of the S1 hole 141 on the first surface 11 as the machining starting point, and perform the first machining along the X direction according to the set first depth until the machining of the S2 hole 142 and the preliminary machining of the S1 hole 141 are completed;

[0029] Use the CNC machining group to take the orifice of the S1 hole 141 on the first surface 11 as the machining starting point, and perform the second machining along the X direction according to the set second depth until the machining of the S1 hole 141 is completed, wherein the drilling head used by the CNC machining group during the second machining is thicker than the drilling head used during the first machining, and the second depth is shallower than the first depth;

[0030] The CNC machining group uses the notch position of the lateral groove 15 on the third surface 13 as the machining starting point, and completes the machining of the lateral groove 15 along the Y direction according to the set third depth.

[0031] The electrical discharge machining group 30 inserts the electrical discharge electrode 34 into the lateral groove 15 to perform electrical discharge machining on one end of the S2 hole 142 facing the lateral groove 15 until the positioning counterbore 143 is machined. The shape of the electrical discharge electrode 34 matches the shape of the positioning counterbore 143. Specifically, as Figure 5 and Figure 6 shown, the structural feature of the positioning counterbore 143 is a non-fully cylindrical hole with a plane on the inner wall (for the convenience of description and distinction, this plane is described as the first plane 144). In this way, a better positioning effect can be formed on the positioning sleeve, and the positioning sleeve can be prevented from rotating when the lateral pin or the extrusion pin moves.

[0032] The beneficial effect of the machining method in the embodiment of the present invention is that according to the depth of the deep hole 14 and the characteristics of the positioning counterbore 143, a lateral groove 15 is added to the side of the mold 10. The lateral groove 15 vertically penetrates into the deep hole 14. By placing an electrical discharge machining device in the lateral groove 15, the required positioning counterbore 143 is machined by electrical discharge. The machining method is simple and reliable, and solves the problems that the required positioning counterbore 143 cannot be machined by a single deep hole drill in the prior art and the problem that the stroke of a single electrical discharge machining is insufficient or the machining is inconvenient. It should be noted that the opening of the newly added lateral groove 15 in the embodiment of the present invention will not affect the functions of other structures in the mold 10.

[0033] According to some preferred embodiments of the present invention, the CNC machining group is a conventional numerical control machine tool in the existing market, including a deep hole 14 drill and a multi-axis CNC machining device. The specific structure and working principle will not be described and limited. Those skilled in the art know and can easily implement it. When machining the S1 hole 141, the first machining of the S2 hole 142, and the second machining of the S2 hole 142, a deep hole 14 drill is used. The drill bit used in the second machining is thicker than that in the first machining. When machining the lateral groove 15, a multi-axis CNC machining device is used. Since the S1 hole 141 and the S2 hole 142 are machined simultaneously in the first machining, a deep hole 14 drill can be used for drilling. The second machining is only for the S2 hole 142. Because the depth of the S2 hole 142 is relatively deep, a deep hole 14 drill is suitable for drilling, so that the aperture of the S2 hole 142 is larger than that of the S1 hole 141 to facilitate accommodating the large end of the positioning sleeve, while the S1 hole 141 is used to accommodate the small end of the positioning sleeve. The depth of the lateral groove 15 is much shallower. Both machine tool machining and electrical discharge machining can be used. However, considering that the lateral groove 15 has a certain width and electrical discharge machining is slow, in the embodiments of the present invention, it is preferably to use existing conventional multi-axis CNC machining devices such as four-axis CNC machining devices or five-axis CNC machining devices for machining, and the machining speed is much faster than that of electrical discharge machining. Since the lateral groove 15 is newly opened to facilitate the machining of the counterbore 143, the three-dimensional data of the mold 10 stored in the CNC machining group is the previous three-dimensional data only with the S1 hole 141 and the S2 hole 142 without the lateral groove 15. Therefore, before machining, the modified three-dimensional data of the mold 10 needs to be stored in the CNC machining group. This three-dimensional data is the three-dimensional data including the S1 hole 141, the S2 hole 142, and the lateral groove 15. According to the three-dimensional data, the position of the notch of the lateral groove 15 on the third surface 13 and the specific dimensions of the lateral groove 15 can be determined during machining. Specifically, the three-dimensional data of the mold 10 with the lateral groove 15 can be obtained by programming in the programming interface of the CNC machining group, so that machining can be carried out according to the data. This step will not be described in detail and limited. Those skilled in the art can easily know and implement it. In addition, it should be noted that when the first machining and the second machining of the deep hole 14 are carried out, the lower surface of the mold 10 is installed on the deep hole 14 drill table for machining. When the second machining is carried out, the direction of the mold 10 needs to be rotated compared with the first machining. When machining the lateral groove 15, the mold 10 needs to be replaced and pressed onto the four-axis table of the four-axis CNC machining device. When machining the counterbore 143, the mold 10 needs to be replaced and adsorbed on the magnetic table of the electric discharge machine 31.

[0034] It should be noted that the second depth includes the width of the lateral groove 15 (the length of the lateral groove 15 along the X direction), that is, the machining depth during the second machining includes the depth of the S1 hole 141 in the finished product and the width of the lateral groove 15. The depth during the first machining, that is, the first depth, is the sum of the depths of the S1 hole 141 and the S2 hole 142 in the finished product and the width of the lateral groove 15, or the sum of the depth of the S2 hole 142 in the finished product and the second depth. The bottom of the lateral groove 15 extends all the way to the farther wall surface of the deeper hole 14 among the two deep holes 14 that is farther from the third surface 13. That is, the depth of the lateral groove 15 includes the diameters of the two deep holes 14 and the distance between the two deep holes 14.

[0035] According to some preferred embodiments of the present invention, before the step of machining the lateral groove 15, there is also a step of machining the discharge electrode 34. Specifically, as Figure 8 and Figure 9 shown, the discharge electrode 34 includes an electrode body 341 in the shape of a square prism and two machining parts 342 that protrude outward and are arranged in parallel at intervals on the same side wall of the electrode body 341 (the wall surface facing the S2 hole 142 during machining). Each machining part 342 has a structure in which one wall surface of a cylinder is cut off along the axial direction to form a plane (for the convenience of distinction and description, this plane is described as the second plane 343 here), and the second plane 343 matches the first plane 144. Since the machining part 342 is arranged on the side wall of the electrode body 341 and protrudes outward, when the discharge electrode 34 is inserted into the lateral groove 15 for machining, to avoid interference between the machining part 342 and the side wall of the lateral groove 15, the width of the electrode body 341 should be designed to be smaller than the width of the lateral groove 15. As Figures 1 to 3 shown, the number of deep holes 14 to be machined is two, and the two deep holes 14 are arranged in parallel at intervals. The step of machining the discharge electrode 34 includes:

[0036] Determining the distance between the two machining parts 342 according to the distance between the two deep holes 14 to be machined;

[0037] Determining the shape and size of the machining part 342 according to the shape and size of the positioning counterbore 143 to be machined. With such a design, the positioning counterbores 143 in the two deep holes 14 can be machined simultaneously at one time, thereby improving the machining efficiency.

[0038] As Figure 1 and Figure 2 shown, since the two deep holes 14 in the mold 10 are not on the same horizontal plane, but one is at a higher horizontal position and the other is at a lower horizontal position, therefore, as Figure 8 and Figure 9As shown, the two machining parts 342 need to be staggeredly arranged correspondingly, that is, the two machining parts 342 are not on the same straight line in the length direction of the electrode body 341, so as to correspond to the two deep holes 14 one by one. Therefore, at this time, the distance between the two machining parts 342 is not the vertical distance between the projections of the two deep holes 14 on the same horizontal plane, but greater than this vertical distance.

[0039] According to some preferred embodiments of the present invention, after the step of machining the discharge electrode 34, it further includes the step of assembling the discharge machining group 30. Specifically, as Figure 7 and Figure 8 shown, the discharge machining group 30 includes an electric discharge machine 31, a fixing rod 32, a clamping tool 33 and a discharge electrode 34. The electric discharge machine 31, the fixing rod 32, the clamping tool 33 and the discharge electrode 34 are connected in sequence, wherein the fixing rod 32 is arranged perpendicular to the discharge electrode 34. When machining the positioning counterbore 143, the clamping tool 33 is outside the notch of the side groove 15, that is, part of the discharge electrode 34 still extends outside the side groove 15, which can avoid interference between the clamping tool 33, the fixing rod 32 and the side groove 15. For the electric discharge machine 31, the fixing rod 32 and the clamping tool 33, they are conventional structures in the art, and will not be described and limited in detail specifically. Those skilled in the art know and can easily implement them. Generally during assembly, the electric discharge machine 31, the fixing rod 32 and the clamping tool 33 are assembled first. Therefore, the steps of assembling the discharge machining group 30 include:

[0040] Assembling the discharge electrode 34 onto the clamping tool 33. Specifically, the discharge electrode 34 is connected to the clamping tool 33 through a connecting block, and the electrode body 341 of the discharge electrode 34 and the connecting block are connected together through fasteners such as screws. As Figure 9 shown, the electrode body 341 has a generally T-shaped structure, two machining parts 342 are arranged on one side wall of the small section, and connection holes 344 for connecting the screws for connecting with the connecting block are provided on the large section. The specific structure of the connecting block will not be described and limited in detail either. Those skilled in the art can also easily know and implement it. As an alternative embodiment, the fixing rod 32 may not be included, that is, the electric discharge machine 31 is directly connected to the clamping tool 33 and then connected to the discharge electrode 34, which can reduce its number of parts, cost and weight. In the preferred solution of the embodiment of the present invention, the discharge machining group 30 includes a fixing rod 32, and the fixing rod 32 is lengthened. Specifically, the fixing rod 32 extends along the Z direction, that is, perpendicular to the electrode body 341 of the discharge electrode 34 until the end of the fixing rod 32 connected to the electric discharge machine 31 exceeds the upper surface of the mold 10. Such a design can avoid interference between the electric discharge machine 31 and the mold 10. Preferably, as Figure 7As shown, a square notch 321 is formed on one side of the lower end of the fixed rod 32. The notch 321 forms an installation area for fixing the clamping tooling 33, thereby reducing the volume of the entire electrical discharge machining group 30.

[0041] It should be understood that the above specific embodiments of the present invention are only for illustrative explanation or interpretation of the principles of the present invention, and do not constitute a limitation to the present invention. Therefore, any modifications, equivalent replacements, improvements, etc. made without departing from the spirit and scope of the present invention shall be included within the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all variations and modifications that fall within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A processing method for positioning a countersunk head inside a deep hole of a mold, characterized in that The steps are as follows: Set a reference. Let the side where the orifice of the S1 hole is located be the first surface, the wall surface where the orifice of the S2 hole is located be the second surface, the side surface that is adjacent to both the first surface and the second surface and is closer to the deep hole to be machined be the third surface, the direction parallel to the axis of the deep hole to be machined be the X direction, and the direction along the first surface be the Y direction; Use the CNC machining group to take the orifice position of the S1 hole on the first surface as the machining starting point, and perform the first machining along the X direction according to the set first depth until the machining of the S2 hole and the preliminary machining of the S1 hole are completed; Use the CNC machining group to take the orifice of the S1 hole on the first surface as the machining starting point, and perform the second machining along the X direction according to the set second depth until the machining of the S1 hole is completed. The drilling head used by the CNC machining group during the second machining is thicker than the drilling head used during the first machining, and the second depth is shallower than the first depth; Use the CNC machining group to take the notch position of the lateral groove on the third surface as the machining starting point, and complete the machining of the lateral groove along the Y direction according to the set third depth; Use the electric discharge machining group to insert the discharge electrode into the lateral groove to perform electric discharge machining on one end of the S2 hole facing the lateral groove until the machining of the locating counterbore is completed, where the shape of the discharge electrode matches the shape of the locating counterbore.

2. The processing method of a countersunk head positioned inside a deep hole of a mold according to claim 1, characterized in that, The CNC machining group includes a deep hole drill and a multi-axis CNC machining device; During the machining of the S1 hole, the first machining of the S2 hole, and the second machining of the S2 hole, a deep hole drill is used, and the drill bit during the second machining is thicker than the drill bit during the first machining; during the machining of the lateral groove, a multi-axis CNC machining device is used; Before machining, the three-dimensional data of the mold is stored in the CNC machining group, and the three-dimensional data includes the three-dimensional data of the S1 hole, the S2 hole, and the lateral groove.

3. The machining method of a countersunk head positioned inside a deep hole of a mold according to claim 2, characterized in that, The second depth includes the width of the lateral groove; or The multi-axis CNC machining device is a four-axis CNC machining device or a five-axis CNC machining device.

4. A processing method for positioning a countersunk head inside a deep hole of a mold according to any one of claims 1-3, characterized in that, Before the step of machining the lateral groove, there is also a step of machining the discharge electrode.

5. A processing method for positioning a countersunk head inside a deep hole of a mold according to claim 4, characterized in that, The discharge electrode includes an electrode body and two machining parts that protrude outward and extend parallel and spaced apart on the same side wall of the electrode body, and the width of the electrode body is smaller than the width of the lateral groove; The number of deep holes to be machined is two, and the two deep holes are arranged parallel and spaced apart; the step of machining the discharge electrode includes: Determine the spacing between the two machining parts according to the spacing between the two deep holes to be machined; Determine the shape and size of the machining parts according to the shape and size of the locating counterbore to be machined.

6. The processing method of a counterbore positioned inside a deep hole of a mold according to claim 5, characterized in that, The two machining parts are arranged staggeredly; The bottom of the lateral groove extends into the deep hole far from the third surface.

7. A processing method for positioning a countersunk head inside a deep hole of a mold according to claim 6, characterized in that, After the step of machining the discharge electrode, there is also a step of assembling the electric discharge machining group.

8. A processing method for positioning a countersunk head inside a deep hole of a mold according to claim 7, characterized in that, The electric discharge machining group includes an electric discharge machine, a clamping tooling, and a discharge electrode, and the electric discharge machine is connected to the clamping tooling; the step of assembling the electric discharge machining group includes: Assemble the discharge electrode onto the clamping tooling.

9. A processing method for positioning a countersunk head inside a deep hole of a mold according to claim 8, characterized in that The electric discharge machining group also includes a fixing rod, and the fixing rod is connected between the electric discharge machine and the clamping tooling; One end of the fixing rod is provided with a notch, and the notch forms an installation area for fixing the clamping tooling.

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