Deep small square hole electric spark machining device and machining method

Abstract

The application discloses a deep small square hole electric spark machining device and a machining method, and belongs to the technical field of part machining.The deep small square hole electric spark machining device comprises the following steps: S100, a drill bit is used to drill a circular hole with a diameter smaller than the width H1 of the deep small square hole at the bottom of the center circular hole according to the width H1 of the deep small square hole; S200, an electrode and an electrode rod are connected through threads and assembled together on an electric spark machine tool, and the electrode is divided into a rough machining electrode and a fine machining electrode; S300, rough machining is first performed: the rough machining electrode is used to axially feed the deep small square hole along the Z-axis of the center circular hole, and the deep small square hole has a margin of not less than 0.03 mm on a single side; and S400, fine machining is performed on the basis of the rough machining deep small square hole by using the fine machining electrode, and the deep small square hole is formed by using a circular translational mode for fine machining. The deep small blind square hole is machined by using the electrode electric spark machining method in the mode of preforming the circular hole by drilling, then performing straight feeding rough machining and translational fine machining, so that the problem of high precision and low cost manufacturing of the deep small blind square hole is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of part machining, in particular, to a deep small square hole electric spark machining device. In addition, the present application also relates to a machining method comprising the deep small square hole electric spark machining device. BACKGROUND

[0002] The information provided in this section is for the purpose of generally presenting the context of the present application. The work of the presently named inventors, to the extent the descriptions are described in this section, as well as aspects of the descriptions that can not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present application.

[0003] In the field of part machining of an aero-engine, a certain type of shaft has a deep small square hole 2000 in the form of a square blind hole at the bottom end of the center circular hole 1000. The length from the bottom of the deep small square hole 2000 to the shaft end face is relatively long, the hole depth is also relatively deep, and chamfering is required at the four corners of the deep small square hole 2000. Please refer to the structure schematic diagram of the deep small square hole 2000 shown in the accompanying drawings of the specification. Figure 1 And Figure 2 Due to the high precision requirement of such deep hole machining, the machining size precision is generally ≤0.02mm, and the machining precision is difficult to meet the requirement due to tool wear, cutting vibration and other factors when machining by milling, slotting and other mechanical machining methods.

[0004] In addition, if the part shaft to be machined with the deep small square hole 2000 is not clamped stably during machining, it will have a great impact on the machining quality. At the same time, since the part shaft has different diameters and lengths, if multiple sets of clamps are configured, there will be a problem of increasing cost.

[0005] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the present application, and therefore can include information that does not constitute prior art known to those skilled in the art. SUMMARY

[0006] In view of at least one of the above technical problems, the present application provides a deep small square hole electric spark machining device, which can clamp and position the part shaft by pushing the multiple sets of sliding mechanisms and first clamping assemblies on both sides of the support member by the pushing member at one time. The sliding mechanisms and first clamping assemblies can adjust the position, which not only can adapt to the positioning of part shafts with different diameters, but also can meet the stable clamping of part shafts with different lengths, so as to improve the machining quality of the deep small square hole.

[0007] Meanwhile, the present application provides a machining method using the above deep small square hole electric spark machining device, which solves the problem of high-precision and low-cost manufacturing of deep small blind square holes.

[0008] According to an aspect of the present application, a deep small square hole electric spark machining device is provided, comprising a drill bit, an electrode and an electrode rod, the deep small square hole electric spark machining device is used for clamping a part shaft and machining a deep small square hole at the bottom of the center hole of the part shaft, and the deep small square hole electric spark machining device further comprises a base, a support, a pushing piece, a locking piece, a sliding mechanism and a first clamping assembly:

[0009] The support is arranged on the base, the pushing piece is movably arranged on both sides of the support, the pushing piece on both sides is enclosed with the side wall on both sides of the support to form two limiting channels, and the locking piece is used for connecting and locking the pushing piece and the side wall of the support;

[0010] The sliding mechanism is provided in multiple groups, each group of the sliding mechanism is movably arranged in the limiting channel on both sides, the sliding mechanism comprises a sliding block and a connecting rod assembly, a strip-shaped limiting hole is formed in the pushing piece, a plurality of limiting screw holes are arranged in the strip-shaped limiting hole, the connecting rod assembly is used for connecting the sliding block through the strip-shaped limiting hole and driving the sliding block to move along the strip-shaped limiting hole, the connecting rod assembly is further used for being connected with the limiting screw hole through a thread, and the first clamping assembly is arranged on the sliding block. The first clamping assemblies on both sides of the support are used for clamping and limiting the two sides of the part shaft one by one, and the locking piece is further used for driving the pushing piece to approach or move away from the support when the connecting rod assembly is connected with the limiting screw hole, so as to drive the sliding block and the first clamping assembly to clamp and limit the two sides of the part shaft.

[0011] In some embodiments of the present application, the locking piece comprises a locking screw, and a first end of the locking screw is used for penetrating through the pushing piece and cooperating with a pre-set connecting screw hole on the side wall of the support.

[0012] In some embodiments of the present application, a second end of the locking screw is provided with a handle, and a guide rod is arranged on the side wall on both sides of the support, and the guide rod is used for penetrating through the pushing piece and guiding the pushing piece.

[0013] In some embodiments of the present application, the connecting rod assembly comprises a connecting rod, a stud and a hand wheel, one end of the connecting rod is connected with a bearing on the side wall of the sliding block, the other end of the connecting rod is connected with the stud, the hand wheel is arranged at the tail end of the stud, the stud is used for cooperating with the limiting screw hole, and the connecting rod is used for sliding into the strip-shaped limiting hole to drive the sliding block to move along the strip-shaped limiting hole after the stud is separated from the limiting screw hole.

[0014] In some embodiments of the present application, the first clamping assembly comprises a first movable rod, a first compression spring and a limiting plate, a support plate is arranged on the sliding block, the first movable rod is movably arranged on the support plate, one end of the first movable rod close to the support is connected with the limiting plate, the first compression spring is compressed between the support plate and the limiting plate, and the limiting plate is used for abutting and compressing the part shaft.

[0015] In some embodiments of the present application, the deep small square hole electric spark machining device further comprises a second clamping assembly, the second clamping assembly comprising a second movable rod, a support block and a second compression spring, the sliding block is provided with a support plate, the second movable rod is used to movably pass through the support plate, and the second movable rod is located below the first movable rod, the support block is arranged on one side of the second movable rod close to the support piece, and the second compression spring is pressed between the support plate and the support block.

[0016] In some embodiments of the present application, a plurality of limiting grooves are arranged on the support piece at intervals, and the limiting grooves are used to limit the support block.

[0017] According to another aspect of the present application, a deep small square hole electric spark machining method is also provided, which adopts the deep small square hole electric spark machining device, and the deep small square hole electric spark machining method comprises the following steps:

[0018] S100, according to the width H1 of the deep small square hole, a circular hole with a diameter smaller than H1 is drilled at the bottom of the center circular hole by using a drill bit;

[0019] S200, the electrode and the electrode rod are connected by threads and assembled together on the electric spark machine, and the electrode is divided into a rough machining electrode and a finishing electrode;

[0020] S300, rough machining is first performed: the rough machining electrode is used to axially feed the deep small square hole along the Z-axis of the center circular hole, and a single side of the deep small square hole has a margin of not less than 0.03 mm;

[0021] S400, on the basis of the rough machining deep small square hole, the finishing electrode is used for finishing, and the deep small square hole is formed by using a circular translation mode.

[0022] In some embodiments of the present application,

[0023] The length of the finishing electrode satisfies the following formula:

[0024] L32=L1+2 (1)

[0025] In the formula, L32 is the length (mm) of the finishing electrode, and L1 is the depth (mm) of the deep small square hole;

[0026] The length L31 of the rough machining electrode is (4-6) mm.

[0027] In some embodiments of the present application, in step S400, three circular translation mode finishings are performed in sequence, and the circular translation radius R (mm) of the finishing electrode satisfies the following formula each time:

[0028] The first circular translation radius R1 is R1=(H1-H2) / 2-D-0.01 (2)

[0029] Second circular translational radius R2: R2=(H1-H2) / 2-D-0.005 (3)

[0030] Third circular translational radius R3: R3=(H1-H2) / 2-D-0.005+△H / 2 (4)

[0031] In the above formula: H1 is the width of the deep small square hole (mm), H2 is the width of the finished electrode (mm), △H is the difference between the width size allowance of the deep small square hole (2000) after the first circular translation and the second circular translation (mm), and D is the spark discharge gap (mm).

[0032] The application has the following beneficial effects:

[0033] The deep small square hole electric spark machining device of the application connects the pushing piece through the locking piece on both sides of the support piece, and can drive the pushing piece to move through the locking piece. The sliding block realizes the movable installation of the first clamping assembly. The sliding block is connected with the pushing piece through the connecting rod assembly. The part shaft can be clamped and limited by the first clamping assembly. A plurality of sliding blocks and first clamping assemblies can be moved at one time by the pushing piece, so that the part shaft can be quickly clamped and fixed multiple times. The spacing between the first clamping assemblies on both sides of the support piece is convenient to adjust, and can adapt to the clamping and limiting of part shafts of different diameters. At the same time, the connecting rod assembly can drive the sliding block to move along the strip-shaped limiting hole on the pushing piece, so as to realize the position adjustment of the sliding block and the first clamping assembly, thereby adapting to the clamping needs of part shafts of different lengths, effectively improving the adaptability of the device, stably clamping different part shafts, and ensuring the machining quality of the deep small square hole.

[0034] The deep small square hole electric spark machining method also has the beneficial effects described above, and further comprises the steps of prefabricating a circular hole by drilling with a drill bit, using a straight feed rough machining and translational finishing method, and using an electrode to machine a deep small square hole by electric spark, thereby solving the problem of high-precision and low-cost manufacturing of deep small square holes.

[0035] Of course, implementing any product of the application does not necessarily require achieving all the advantages described above. In addition to the purposes, features and advantages described above, the application has other purposes, features and advantages. The application will be further described below with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0036] The accompanying drawings, which form a part of the present application, are intended to provide further understanding of the present application, and the illustrative embodiments of the present application and their description serve the purpose of explaining the present application. The accompanying drawings do not constitute an inappropriate limitation on the present application. In the drawings:

[0037] Figure 1 is a schematic view of the position of the deep small square hole on the part shaft;

[0038] Figure 2 is a structural schematic diagram of the deep small square hole of the present application;

[0039] Figure 3 is a structural schematic diagram of the electrode and electrode rod connection of the preferred embodiment of the present application;

[0040] Figure 4 is a structural schematic diagram of the electrode rod of the preferred embodiment of the present application;

[0041] Figure 5 is a structural schematic diagram of the electrode of the preferred embodiment of the present application;

[0042] Figure 6 is a structural schematic diagram of the internal structure of the electrode of the preferred embodiment of the present application;

[0043] Figure 7 is a schematic diagram of the installation of the pushing piece of the preferred embodiment of the present application;

[0044] Figure 8 is a structural schematic diagram of the sliding mechanism of the preferred embodiment of the present application;

[0045] Figure 9 is a structural schematic diagram of the pushing piece of the preferred embodiment of the present application;

[0046] Figure 10 is a structural schematic diagram of the second clamping assembly of the preferred embodiment of the present application;

[0047] Legend: 1000, center hole; 2000, deep small square hole; 100, electrode; 200, electrode rod; 1, base; 2, support piece; 21, limiting groove; 3, pushing piece; 31, strip-shaped limiting hole; 32, limiting screw hole; 4, locking piece; 5, sliding mechanism; 51, support plate; 52, sliding block; 53, connecting rod assembly; 531, connecting rod; 532, stud; 533, hand wheel; 6, first clamping assembly; 61, first movable rod; 62, first compression spring; 63, limiting plate; 7, second clamping assembly; 71, second movable rod; 72, support block; 73, second compression spring. DETAILED DESCRIPTION

[0048] The embodiments of the present application are described in detail below with reference to the accompanying drawings, but the present application can be implemented in various different ways as defined and covered by the following.

[0049] Figure 1 is a schematic diagram of the position of the deep small square hole of the present application on the part shaft; Figure 2 is a structural schematic diagram of the deep small square hole of the present application; Figure 3 is a structural schematic diagram of the electrode and electrode rod connection of the preferred embodiment of the present application; Figure 4is a structural schematic diagram of an electrode rod of a preferred embodiment of the present application; Figure 5 is a structural schematic diagram of an electrode of a preferred embodiment of the present application; Figure 6 is a structural schematic diagram of an electrode of a preferred embodiment of the present application; Figure 7 is a mounting schematic diagram of a pushing piece of a preferred embodiment of the present application; Figure 8 is a structural schematic diagram of a sliding mechanism of a preferred embodiment of the present application; Figure 9 is a structural schematic diagram of a pushing piece of a preferred embodiment of the present application; Figure 10 is a structural schematic diagram of a second clamping assembly of a preferred embodiment of the present application.

[0050] A deep small square hole electric spark machining device, comprising a drill bit, an electrode 100 and an electrode rod 200, is used for clamping a part shaft and machining a deep small square hole 2000 at the bottom of a center circular hole 1000 of the part shaft, and further comprises a base 1, a supporting piece 2, a pushing piece 3, a locking piece 4, a sliding mechanism 5 and a first clamping assembly 6:

[0051] The supporting piece 2 is arranged on the base 1, the pushing piece 3 is movably arranged on both sides of the supporting piece 2, the pushing piece 3 on both sides and the side wall on both sides of the supporting piece 2 respectively enclose two limiting channels, and the locking piece 4 is used for connecting and locking the pushing piece 3 and the side wall of the supporting piece 2;

[0052] The sliding mechanism 5 is provided in multiple groups, each group of the sliding mechanism 5 is movably arranged in the limiting channel on both sides, the sliding mechanism 5 comprises a sliding block 52 and a connecting rod assembly 53, a strip-shaped limiting hole 31 is formed on the pushing piece 3, a plurality of limiting screw holes 32 are arranged in the strip-shaped limiting hole 31, the connecting rod assembly 53 is used for connecting the sliding block 52 through the strip-shaped limiting hole 31 and driving the sliding block 52 to move along the strip-shaped limiting hole 31, the connecting rod assembly 53 is also used for being connected with the limiting screw hole 32 through a thread, and the first clamping assembly 6 is arranged on the sliding block 52, the first clamping assembly 6 on both sides of the supporting piece 2 is used for clamping and limiting the two sides of the part shaft one by one, and the locking piece 4 is further used for driving the pushing piece 3 to approach or move away from the supporting piece 2 when the connecting rod assembly 53 is connected with the limiting screw hole 32, thereby driving the sliding block 52 and the first clamping assembly 6 to clamp and limit the two sides of the part shaft.

[0053] Here, the meaning of “the pushing piece 3” refers to a structure connected with the supporting piece 2 through the locking piece 4, in some embodiments, the pushing piece 3 is a plate-shaped structure, and the supporting piece 2 is a boss structure on the base 1.

[0054] The deep small square hole electric spark machining device of the application is connected with the pushing piece 3 through the locking piece 4 on both sides of the support piece 2, and the pushing piece 3 can be moved by the locking piece 4, the movable installation of the first clamping assembly 6 is realized through the sliding block 52, the sliding block 52 is connected with the pushing piece 3 through the connecting rod assembly 53, the part shaft can be clamped and limited by the first clamping assembly 6, and a plurality of sliding blocks 52 and first clamping assemblies 6 can be moved at one time by the pushing piece 3, so that the part shaft is quickly clamped and fixed in multiple ways, the spacing between the first clamping assemblies 6 on both sides of the support piece 2 is convenient to adjust, and the clamping and limiting of the part shaft of different diameters can be adapted. At the same time, the connecting rod assembly 53 can drive the sliding block 52 to move along the strip limiting hole 31 on the pushing piece 3, the position adjustment of the sliding block 52 and the first clamping assembly 6 is realized, so that the clamping demand of the part shaft of different lengths can be adapted, the adaptability of the device is effectively improved, different part shafts are stably clamped, and the machining quality of the deep small square hole 2000 is ensured.

[0055] Preferably, referring to Figure 7 , the locking piece 4 comprises a locking screw, and a first end of the locking screw is used for penetrating through the pushing piece 3 and cooperating with a preset connecting screw hole on the side wall of the support piece 2.

[0056] Specifically, a second end of the locking screw is provided with a handle, and a guide rod is arranged on the side wall on both sides of the support piece 2, and the guide rod is used for penetrating through the pushing piece 3 and guiding the pushing piece 3.

[0057] It can be understood that the operator can drive the locking screw to rotate through the handle, so that the pushing piece 3 and the sliding block 52 and the first clamping assembly 6 are brought close to the support piece 2 in the process that the locking screw is screwed into the connecting screw hole of the support piece 2, and then the part shaft can be pressed and limited by the first clamping assemblies 6 on both sides.

[0058] The handle not only facilitates the rotation of the locking screw, but also can limit the pushing piece 3.

[0059] Preferably, referring to Figure 8 , 10 , the connecting rod assembly 53 comprises a connecting rod 531, a stud 532 and a hand wheel 533, one end of the connecting rod 531 is connected with a bearing on the side wall of the sliding block 52, the other end of the connecting rod 531 is connected with the stud 532, the hand wheel 533 is arranged at the tail end of the stud 532, the stud 532 is used for cooperating with the limiting screw hole 32, and the connecting rod 531 is used for sliding into the strip limiting hole 31 to drive the sliding block 52 to move along the strip limiting hole 31 after the stud 532 is separated from the limiting screw hole 32.

[0060] It can be understood that by cooperating the threaded hole 32 with the threaded stud 532, the limiting fixing of the connecting rod 531, the sliding block 52 and the first clamping assembly 6 can be realized. At this time, the sliding block 52 and the first clamping assembly 6 are pushed and moved by the pusher 3, so that the part shaft is pressed and limited. Then, the pusher 3 is limited by the locking member 4,

[0061] Preferably, as shown in Figure 7 、 8 , the first clamping assembly 6 comprises a first movable rod 61, a first compression spring 62 and a limiting plate 63. The sliding block 52 is provided with a support plate 51. The first movable rod 61 is arranged to be movably arranged on the support plate 51. The first movable rod 61 is connected to the limiting plate 63 at the end close to the support 2. The first compression spring 62 is arranged to be compressed between the support plate 51 and the limiting plate 63. The limiting plate 63 is arranged to abut and press the part shaft.

[0062] It can be understood that by pushing the sliding blocks 52 and the support plates 51 on both sides to the support 2 by the pusher 3, the limiting plates 63 on both sides are brought into abutment and press the part shaft on both sides, so that the part shaft is limited and clamped. The first compression spring 62 provides an elastic force to push the limiting plate 63 away from the support plate 51. The first compression spring 62 can play a buffering protection role, avoiding the rigid collision between the limiting plate 63 and the part shaft, which is easy to cause damage by knocking.

[0063] Optionally, the limiting plate 63 is an arc-shaped plate structure, which can more widely adapt to the limiting and clamping of part shafts of different diameters, and is conducive to improving the stability of the pressing and limiting.

[0064] Preferably, as shown in Figure 7 、 8 , the deep small square hole electric spark machining device further comprises a second clamping assembly 7. The second clamping assembly 7 comprises a second movable rod 71, a support block 72 and a second compression spring 73. The sliding block 52 is provided with a support plate 51. The second movable rod 71 is arranged to be movably arranged on the support plate 51. The second movable rod 71 is arranged below the first movable rod 61. The support block 72 is arranged on the side of the second movable rod 71 close to the support 2. The second compression spring 73 is arranged to be compressed between the support plate 51 and the support block 72.

[0065] It can be understood that in order to strengthen the stability of the limiting and supporting of the part shaft, the second clamping assembly 7 is arranged to support the bottom of the part shaft. When the second movable rods 71 on both sides are close to each other, the bottom of the part shaft can be supported. In cooperation with the first clamping assembly 6, the stability of the clamping and supporting of the part shaft can be strengthened, which is conducive to improving the machining precision of the deep small square hole 2000. The second compression spring 73 can further provide the effect of weight reduction and buffering protection.

[0066] Preferably, as shown inFigure 9 As shown, a plurality of limiting grooves 21 are arranged on the support 2 at intervals, and the limiting grooves 21 are used for limiting the support block 72.

[0067] It can be understood that when the two second movable rods 71 are moved towards each other, the support block 72 is driven to slide into the limiting groove 21, at this time, the bottom of the support block 72 is in contact with the bottom surface of the limiting groove 21, the support block 72 and the second movable rod 71 can be supported through the limiting groove 21, and the limiting groove 21 can limit the two sides of the support block 72, which is beneficial to improve the stability of the support block 72 and the second movable rod 71, and ensure the stable support and limitation of the part shaft.

[0068] According to another aspect of the present application, a deep small square hole electric spark machining method is also provided, which adopts the deep small square hole electric spark machining device, and the deep small square hole electric spark machining method comprises the following steps:

[0069] S100, according to the width H1 of the deep small square hole 2000, a circular hole with a diameter smaller than H1 is drilled at the bottom of the center circular hole 1000 by using a drill bit;

[0070] S200, the electrode 100 and the electrode rod 200 are connected through threads and assembled together on an electric spark machine, and the electrode 100 is divided into a rough machining electrode and a fine machining electrode;

[0071] S300, rough machining is first performed: the deep small square hole 2000 is machined along the Z-axis axial feed of the center circular hole 1000 by using the rough machining electrode, and a single side of the deep small square hole 2000 has a margin of not less than 0.03 mm;

[0072] S400, on the basis of the rough machining of the deep small square hole 2000, fine machining is performed by using the fine machining electrode, and the deep small square hole 2000 is formed by using a circular translational mode for fine machining.

[0073] The deep small square hole electric spark machining method also has the beneficial effects as described above, and further comprises the steps of preforming a circular hole by using a drill bit, then performing straight feed rough machining and translational fine machining, and using a red copper electrode to machine the deep small square hole 2000, so as to solve the problem of high precision and low cost in manufacturing the deep small square hole 2000. The electric spark forming machining has the effects of no machining stress and high precision. The method can be popularized to electric spark forming machining of other deep small circular holes and special-shaped holes.

[0074] Preferably, the length of the fine machining electrode satisfies the following formula:

[0075] L32=L1+2mm (1)

[0076] In the formula, L32 is the length (mm) of the fine machining electrode, and L1 is the depth (mm) of the deep small square hole 2000;

[0077] The length of the rough-machined electrode is L31 = (4~6) mm.

[0078] It is understandable that electrode 100 and electrode rod 200 are fastened by threads to facilitate the replacement of electrode 100. Considering electrode lifespan, chip removal effect, machining quality and efficiency, the roughing electrode should not be too long, and the length of the roughing electrode is L31 = (4~6) mm; to improve machining efficiency, the finishing electrode only moves to expand the hole and does not need to be fed along the Z-axis. The length of the finishing electrode should be slightly longer than the depth of the small square hole 2000, and the length of the finishing electrode is L32 = L1 + 2.

[0079] Preferably, in step S400, three circular translational finishing processes are performed sequentially, and the circular translational radius R (mm) of the electrode in each finishing process satisfies the following formula:

[0080] The radius of the first circular translation is R1: R1=(H1-H2) / 2-D-0.01 (2)

[0081] The radius of the second circular translation is R2: R2=(H1-H2) / 2-D-0.005 (3)

[0082] The radius of the third circular translation is R3: R3 = (H1 - H2) / 2 - D - 0.005 + ΔH / 2 (4)

[0083] In the above formula: H1 is the width of the deep small square hole 2000 (mm), H2 is the width of the finishing electrode (mm), △H is the difference in the width dimensional allowance of the deep small square hole 2000 after the first circular translation and the second circular translation (mm), and D is the electrical discharge gap (mm).

[0084] It is understandable that by performing three translational machining operations on the precision electrode, and adjusting the accuracy setting of the third translational radius based on the first two translational operations, higher precision control can be achieved, which can effectively ensure the dimensional accuracy of the 2000 deep small square hole and effectively improve the pass rate of the 2000 deep small square hole machining.

[0085] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0086] The principles and implementations of the present application are described herein with specific examples. The above examples are only used to help understand the method and its core idea of the present application. The above description is only the preferred embodiments of the present application. It should be pointed out that due to the limited nature of the language expression, there are objectively infinite specific structures, and for ordinary skilled persons in the art, without departing from the principles of the present application, a number of improvements, refinements or changes can be made, or the above technical features can be combined in an appropriate manner. The improvements, refinements, changes or combinations, or the application of the inventive concept and technical solution to other fields without improvement, shall be regarded as the protection of the present application.

Claims

1. A deep small square hole electric discharge machining device comprising a drill bit, an electrode (100) and an electrode rod (200), the deep small square hole electric discharge machining device being used for clamping a part shaft and machining a deep small square hole (2000) at the bottom of a center circular hole (1000) of the part shaft, characterized in that, The deep small square hole electric spark machining device further comprises a base (1), a supporting piece (2), a pushing piece (3), a locking piece (4), a sliding mechanism (5) and a first clamping assembly (6): The supporting piece (2) is arranged on the base (1), the pushing piece (3) is movably arranged on both sides of the supporting piece (2), the pushing pieces (3) on both sides and the side walls on both sides of the supporting piece (2) respectively form two limiting channels, and the locking piece (4) is used for connecting and locking the pushing piece (3) and the side wall of the supporting piece (2); The sliding mechanism (5) is provided in multiple groups, each group of the sliding mechanism (5) is movably arranged in the limiting channel on both sides, the sliding mechanism (5) comprises a sliding block (52) and a connecting rod assembly (53), a strip-shaped limiting hole (31) is formed in the pushing piece (3), a plurality of limiting screw holes (32) are arranged in the strip-shaped limiting hole (31) at intervals, the connecting rod assembly (53) is used for connecting the sliding block (52) through the strip-shaped limiting hole (31) and driving the sliding block (52) to move along the strip-shaped limiting hole (31), the connecting rod assembly (53) is further used for being connected with the limiting screw hole (32) through a thread, and the first clamping assembly (6) is arranged on the sliding block (52); the first clamping assemblies (6) on both sides of the supporting piece (2) are used for clamping and limiting the two sides of the part shaft one by one, the locking piece (4) is further used for driving the pushing piece (3) to move close to or away from the supporting piece (2) when the connecting rod assembly (53) is connected with the limiting screw hole (32), and then driving the sliding block (52) and the first clamping assembly (6) to clamp and limit the two sides of the part shaft; the connecting rod assembly (53) comprises a connecting rod (531), a stud (532) and a hand wheel (533), one end of the connecting rod (531) is connected with a bearing on the side wall of the sliding block (52), the other end of the connecting rod (531) is connected with the stud (532), the hand wheel (533) is arranged at the tail end of the stud (532), the stud (532) is used for cooperating with the limiting screw hole (32), and the connecting rod (531) is used for sliding into the strip-shaped limiting hole (31) after the stud (532) is separated from the limiting screw hole (32) to drive the sliding block (52) to move along the strip-shaped limiting hole (31); the first clamping assembly (6) comprises a first movable rod (61), a first compression spring (62) and a limiting plate (63), the sliding block (52) is provided with a supporting plate (51), the first movable rod (61) is movably arranged on the supporting plate (51), one end of the first movable rod (61) close to the supporting piece (2) is connected with the limiting plate (63), the first compression spring (62) is elastically pressed between the supporting plate (51) and the limiting plate (63), and the limiting plate (63) is used for abutting and pressing the part shaft.

2. The apparatus according to claim 1, wherein The locking piece (4) comprises a locking screw, and a first end of the locking screw is used for cooperating with a connecting screw hole prearranged on the side wall of the supporting piece (2) after penetrating through the pushing piece (3).

3. The apparatus according to claim 1, wherein A handle is arranged at a second end of the locking screw, and a guide rod is arranged on the side wall on both sides of the supporting piece (2), the guide rod is used for penetrating through the pushing piece (3) and guiding the pushing piece (3).

4. The apparatus according to claim 1, wherein The deep small square hole electric spark machining device further comprises a second clamping assembly (7), the second clamping assembly (7) comprises a second movable rod (71), a supporting block (72) and a second compression spring (73), a supporting plate (51) is arranged on the sliding block (52), the second movable rod (71) is arranged to be movable on the supporting plate (51), and the second movable rod (71) is located below the first movable rod (61), the supporting block (72) is arranged on one side of the second movable rod (71) close to the supporting piece (2), and the second compression spring (73) is elastically pressed between the supporting plate (51) and the supporting block (72).

5. The apparatus according to claim 4, wherein A plurality of limiting grooves (21) are arranged on the supporting piece (2) at intervals, and the limiting grooves (21) are used for limiting the supporting block (72).

6. A deep small hole electric discharge machining method characterized by The deep small square hole electric spark machining device and method adopt any one of the devices and methods in claims 1-5, and the method comprises the following steps: S100, according to the width H1 of the deep small square hole (2000), a circular hole with a diameter smaller than H1 is drilled at the bottom of the center circular hole (1000) by using a drill bit; S200, the electrode (100) and the electrode rod (200) are connected by threads and assembled together on an electric spark machine, and the electrode (100) is divided into a rough machining electrode and a fine machining electrode; S300, rough machining is first performed: the rough machining electrode is used to feed the deep small square hole (2000) along the Z-axis of the center circular hole (1000) in the axial direction, and a single side of the deep small square hole (2000) is left with a margin of not less than 0.03 mm; S400, on the basis of the rough machining deep small square hole (2000), the fine machining electrode is used for fine machining, and the circular translation mode is used for fine machining to form the deep small square hole (2000).

7. The deep small square hole electric spark machining method according to claim 6, wherein the length of the fine machining electrode satisfies the following formula: L32=L1+2 (1) wherein: L32 is the length (mm) of the fine machining electrode, and L1 is the depth (mm) of the deep small square hole (2000); The length L31 of the rough machining electrode is (4-6) mm. In step S400, three circular translation mode fine machining operations are performed in sequence, and the circular translation radius R (mm) of the fine machining electrode satisfies the following formulae respectively:

8. The method of claim 6, wherein the deep small hole electrical discharge machining is characterized by, The first circular translation radius R1 is R1=(H1-H2) / 2-D-0.01 (2) The second circular translation radius R2 is R2=(H1-H2) / 2-D-0.005 (3) The third circular translation radius R3 is R3=(H1-H2) / 2-D-0.005+△H / 2 (4) In the above formulae: H1 is the width (mm) of the deep small square hole (2000), H2 is the width (mm) of the fine machining electrode, △H is the difference (mm) in the size margin of the width of the deep small square hole (2000) after the first circular translation and the second circular translation, and D is the electric spark discharge gap (mm). ​

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