A combined boring bar with the function of adjusting the rod length

Abstract

The present invention discloses a combined boring bar with a function of adjusting the rod length, belonging to the field of deep hole machining. It includes a first boring bar and a second boring bar. A first through hole is provided in the middle of the collet, one end of which is fixedly connected to the second boring bar. The second boring bar is provided with a second through hole, and the other end is used for the coaxial embedding of the first boring bar. Moreover, a locking notch is provided at the end of the collet matching the first boring bar, and a clamping assembly is arranged corresponding to the locking notch. When the clamping assembly is connected to the locking notch, the first boring bar embedded in the first through hole can be clamped and locked in the collet, and the adjustment of the length of the combined boring bar can be realized through the tightening and loosening of the clamping assembly and the axial displacement of the first boring bar in the collet and the second boring bar. The present invention can realize the free selection of any length value within a certain range for the overall boring bar and the variable angle adjustment of the boring head, and has good practical application effects and good application prospects.

Description

Technical Field

[0001] The present invention belongs to the field of deep hole machining, and particularly relates to a combined boring bar with a rod length adjustment function. Background Art

[0002] The technological process of deep hole machining generally includes two processes: drilling and boring. Among them, drilling is the primary machining process, and the forming size, tolerance, and surface quality of the hole are all ensured by boring. Therefore, boring is the key link in deep hole machining.

[0003] In the boring process, when switching to workpieces with different machining strokes or when the machining stroke of the workpiece changes, there is often a problem that the length of the boring bar is greater than the machining stroke, and the overhang length of the boring bar is relatively long. In the prior art, a combined boring bar is usually adopted, and the overall length of the boring bar is adjusted by replacing the boring bar. However, the conventional combined boring bar is usually set in groups and sections, and its connection method is a fixed connection, and relative displacement adjustment cannot be performed between the two, so that the adjustment of the rod length range of this combined boring bar is limited to the selection of several values.

[0004] Moreover, due to the fixed connection relationship between the two boring bars, the boring bar cannot freely adjust the angle, and it is only suitable for general boring requirements, so it cannot meet the product requirements of some products that require special machining inside the hole.

[0005] Therefore, there is an urgent need for a boring bar that can quickly adjust the rod length and the angle of the boring bar to process workpieces to be machined with different machining strokes and different product requirements. Summary of the Invention

[0006] In view of one or more of the above defects or improvement requirements in the prior art, the present invention provides a combined boring bar with a rod length adjustment function, which can realize the reciprocating displacement of the first boring bar in the axial direction and realize the adjustment of the overall rod length of the combined boring bar.

[0007] To achieve the above object, the present invention provides a combined boring bar with a rod length adjustment function, which includes a first boring bar and a second boring bar, and is characterized in that it further includes a collet:

[0008] A first through hole is provided in the middle of the collet, one end of which is fixedly connected to the second boring bar, and the other end is for the first boring bar to be coaxially inserted; and

[0009] The collet is provided with a locking notch matching the end of the first boring bar, and a clamping assembly is provided corresponding to the locking notch, so that when the clamping assembly is connected to the locking notch, the first boring bar inserted into the first through hole can be clamped and locked in the collet, and the length of the combined boring bar can be adjusted by the tightening and loosening of the clamping assembly and the axial displacement of the first boring bar in the collet.

[0010] As a further improvement of the present invention, a second through hole is axially opened in the middle of the second boring bar, and its inner diameter is larger than the outer diameter of the first boring bar, so that the end of the first boring bar can coaxially extend into the second through hole.

[0011] As a further improvement of the present invention, the clamping assembly includes a clamping block that can be matched and connected to the locking notch, and the inner peripheral wall surface of the clamping block is a curved surface.

[0012] As a further improvement of the present invention, the inner circumferential wall of the clamping block is pressed against the outer circumferential wall of the first boring bar, so that the outer circumferential wall of the first boring bar facing away from the clamping block is pressed against the inner circumferential wall of the first through hole.

[0013] As a further improvement of the present invention, a plurality of protrusions are arranged on the inner peripheral wall surface of the clamping block or an elastic gasket is arranged between the clamping block and the first boring bar.

[0014] As a further improvement of the present invention, the first through hole is a stepped hole, which includes a small-diameter hole provided at one end of the second boring bar and a large-diameter hole radially connected to the locking notch;

[0015] Correspondingly, the clamping assembly includes a sleeve sleeved on the outer periphery of the first boring bar, and the sleeve is arranged at the large diameter hole connected to the locking notch. When the clamping block is matched and docked with the locking notch, the sleeve provides a pre-tightening force to achieve locking of the first boring bar by the clamping sleeve.

[0016] As a further improvement of the present invention, a sealing member is provided between the first through hole and the first boring bar, for sealing the gap therebetween;

[0017] The sealing member is arranged at the annular step at the junction of the large-diameter hole and the small-diameter hole; or an annular groove is opened along the annular direction on the inner peripheral wall surface of the first through hole, so that the sealing member is embedded in the annular groove.

[0018] As a further improvement of the present invention, sealing grooves are circumferentially provided on the inner wall surface and the outer peripheral surface of the sealing member, and sealing rings are respectively provided in the sealing grooves to achieve sealing of the gap between the sealing member and the first boring bar and at the through hole of the jacket.

[0019] As a further improvement of the present invention, the end of the first boring bar extends into the second through hole of the second boring bar;

[0020] The portion of the first boring bar located inside the second boring bar is provided with a top ring, the top ring is sleeved on the first boring bar, and the outer peripheral wall of the top ring is in contact with the inner wall surface of the second boring bar to prevent the first boring bar from shaking inside the second boring bar.

[0021] As a further improvement of the present invention, a plurality of through holes are formed in the top ring along the circumferential direction, and the top ring is fixed to the first boring bar by a fastener, and the fastener does not protrude above the outer peripheral wall surface of the top ring.

[0022] As long as the above improvement technical features do not conflict with each other, they can be combined with each other.

[0023] Generally speaking, compared with the prior art, the above technical solution conceived by the present invention has the following beneficial effects:

[0024] (1) The combined boring bar with the function of adjusting the rod length of the present invention combines and fixedly connects two boring bars through a jacket. One end of the jacket is fixedly connected to the second boring bar, and the other end is used for the first boring bar to be coaxially embedded; and a locking notch is formed in the jacket corresponding to the end of the first boring bar, and a clamping assembly is provided corresponding to the locking notch to realize the tightening and loosening of the first boring bar.

[0025] (2) For the combined boring bar with the function of adjusting the rod length of the present invention, the inner through hole diameters of the jacket and the second boring bar are large enough for the first boring bar to reciprocate therein. When the jacket is in the loosened state, the first boring bar can freely adjust the length of its extension, realizing the free selection of any value within a certain range of the combined boring bar rod length, rather than the selection of several values, expanding the use range of the present invention.

[0026] (3) For the combined boring bar with the function of adjusting the rod length of the present invention, a sleeve is sleeved on the first boring bar. The inner peripheral wall surface of the sleeve is not in close contact with the first boring bar without being extruded. The sleeve is correspondingly arranged in a large-diameter hole radially communicated with the locking notch and is of an elastic structure. When the clamping block is correspondingly connected to match the locking notch, under the extrusion of the outer peripheral mechanism, the inner diameter of the sleeve shrinks, and it is in close contact with the first boring bar, thereby realizing the fastening effect of the clamping assembly on the first boring bar and ensuring that the jacket will not cause damage to the rod body of the first boring bar, playing a protective role.

[0027] (4) For the combined boring bar with the function of adjusting the rod length of the present invention, a seal is provided between the first through hole of the first boring bar and the jacket. Sealing grooves are formed on both the outer peripheral wall surface and the inner peripheral wall surface of the seal for installing sealing rings to seal the gap between the first boring bar and the jacket. At the same time, corresponding sealing rings or gaskets are also provided at the connection between the jacket and the second boring bar to ensure that the coolant entering from the end of the second boring bar will not overflow from these connections.

[0028] (5) The combined boring bar with rod length adjustment function of the present invention has a top ring disposed between the second boring bar and the first boring bar portion extending into the second boring bar. The top ring is an annular structure, and its outer peripheral wall surface is in contact with the second boring bar, and its inner peripheral wall surface is in contact with the first boring bar. The top ring is fixed to the first boring bar by bolt connection, so that the relative position relationship between the first boring bar and the second boring bar is maintained constant, thereby avoiding relative shaking of the first boring bar inside the second boring bar and enhancing the overall rigidity strength of the boring bar structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the overall structure of a combined boring bar with a rod length adjustment function in an embodiment of the present invention;

[0030] Figure 2 It is a schematic diagram of the overall structure of a jacket of a combined boring bar with a rod length adjustment function in an embodiment of the present invention;

[0031] Figure 3 It is a schematic structural diagram of a sleeve body and a clamping block of a combined boring bar with a rod length adjustment function in an embodiment of the present invention;

[0032] Figure 4 It is a schematic structural diagram of a sleeve body and a clamping block of a combined boring bar with a rod length adjustment function in an embodiment of the present invention;

[0033] Figure 5 It is a schematic diagram of the structure of a clamping block and an elastic gasket of a combined boring bar with a rod length adjustment function in one embodiment of the present invention;

[0034] Figure 6 It is a schematic structural diagram of a clamping block of a combined boring bar with a rod length adjustment function in another embodiment of the present invention;

[0035] Figure 7 It is a schematic diagram of the sleeve structure of a combined boring bar with a rod length adjustment function in one embodiment of the present invention;

[0036] Figure 8 It is a schematic diagram of the sleeve structure of a combined boring bar with a rod length adjustment function in another embodiment of the present invention;

[0037] Figure 9 Schematic diagram of the seal structure of a combined boring bar with a rod length adjustment function in an embodiment of the present invention;

[0038] Figure 10 Schematic diagram of the top ring structure of the combined boring bar with a rod length adjustment function in an embodiment of the present invention;

[0039] In all the drawings, the same reference numerals represent the same technical features, specifically:

[0040] 1. First boring bar; 2. Second boring bar;

[0041] 3. Chuck; 301. Chuck body; 302. Clamping block; 303. Sleeve; 304. Seal; 305. Elastic gasket;

[0042] 4. Top ring. Detailed implementation manners

[0043] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0044] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

[0045] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0046] In the present invention, unless otherwise clearly specified and defined, the terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] In the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply indicates that the first feature has a lower horizontal height than the second feature.

[0048] Embodiment:

[0049] The combined boring bar with the function of adjusting the bar length in the preferred embodiment of the present invention is as Figures 1 - 7 shown. It includes a first boring bar 1 and a second boring bar 2. One end of the second boring bar 2 is fixedly connected to one end of the collet 3. The other end of the collet 3 is for the coaxial embedding of the first boring bar 1. And the collet 3 is provided with a locking notch corresponding to the end of the first boring bar 1, and a clamping assembly is provided corresponding to the locking notch, so that when the clamping assembly is connected to the locking notch, the first boring bar 1 embedded in the first through hole can be clamped and locked in the collet 3, and the adjustment of the length of the combined boring bar can be realized through the tightening and loosening of the clamping assembly and the axial displacement of the first boring bar 1 in the collet 3.

[0050] Specifically, the collet 3 includes a collet body 301. The collet body 301 is provided with a first through hole penetrating through both end faces. One end of the collet body 301 is fixedly connected to one end of the second boring bar 2. Among them, the aperture size of the through hole of the collet body 301 is the same as the aperture size of the second boring bar 2, and the inner peripheral wall surfaces between them are in smooth transition. In addition, one end of the second boring bar 2 fixedly connected to the collet body 301 is an internal thread structure. Correspondingly, the end of the collet body 301 is provided with an external thread structure matching the second boring bar 2 to realize the firm connection between the collet body 301 and the second boring bar 2.

[0051] Furthermore, the other end of the collet body 301 is sleeved on the outer periphery of the first boring bar 1. And, as Figure 3 shown, a locking notch is provided at one end of the collet body 301 matching the first boring bar 1, and a clamping block 302 is provided corresponding to the locking notch. For the convenience of understanding, the locking notch can be regarded as formed by the connection of a horizontal section and a longitudinal section perpendicular to the horizontal section at the first through hole of the collet body 301, and the part cut by the section can also be regarded as the clamping block 302 correspondingly.

[0052] As Figure 4As shown, the clamping block 302 is detachably connected to the jacket body 301. A plurality of through holes are axially spaced on the joint surface between the clamping block 302 and the jacket body 301, and the through holes on the clamping block 302 and the jacket body 301 correspond to each other, and the two are connected by means of bolts. Further preferably, the inner peripheral wall surface of the clamping block 302 is an arc surface.

[0053] In an embodiment of the present invention application, the inner peripheral wall surface of the first through hole of the jacket 3 exactly fits the outer peripheral wall surface of the first boring bar 1. The clamping block 302 is correspondingly and matingly connected to the locking notch. It only fits the outer peripheral wall surface of the first boring bar 1 and does not fix the first boring bar 1. On this basis, the present invention proposes corresponding improvement methods:

[0054] As Figure 5 shown, an elastic gasket 305 is provided on the inner peripheral wall surface of the clamping block 302. The pre-tightening force provided by the elastic gasket 305 enables the clamping block 302 to fasten the first boring bar 1 to the jacket body 301, realizing the fixed connection of the first boring bar 1. In another embodiment of the present application, as Figure 6 shown, by adding corresponding convex surfaces or raised structures on the inner peripheral wall surface of the clamping block 302, the first boring bar 1 can also be fastened to the jacket body 301 to realize the fixation of the first boring bar 1. The above two embodiments are only schematic descriptions, including but not limited to setting corresponding pre-tightening modules on the inner peripheral wall surface of the clamping block 302 to enable the clamping block 302 to fix the first boring bar 1 on the jacket body 301.

[0055] As Figure 2 shown, the first through hole of the jacket body 301 is a stepped hole. The end for fixedly connecting with the second boring bar 2 is a small-diameter hole, and the end away from the second boring bar 2 is a large-diameter hole. A sleeve 303 is correspondingly provided at the large-diameter hole radially communicating with the locking notch. The sleeve 303 is an elastic structure. It is sleeved on the first boring bar 1, and the sleeve 303 is in non-fastening contact with the first boring bar 1 without external extrusion. The outer diameter of the sleeve 303 is greater than the inner diameter at the large-diameter hole of the first through hole. When the clamping block 302 starts to be matingly docked with the locking notch, the clamping block 302 and the jacket body 301 simultaneously apply pressure to the sleeve 303. Under the extrusion of the peripheral structure, the sleeve 303 is in close contact with the first boring bar 1, thereby realizing the fastening connection between the first boring bar 1 and the jacket 3. And through the sleeve 303, the clamping block 302 and the jacket body 301 do not directly contact the first boring bar 1, thereby protecting the first boring bar from damage and playing a protective role.

[0056] As Figure 7As shown, in a preferred embodiment, an opening is provided on one side of the sleeve 303, and a plurality of grooves are provided at intervals along the circumferential direction and penetrate the two ends of the sleeve 303. When the sleeve 303 is squeezed by the peripheral structure, the two cut surfaces at the opening are connected, the inner diameter of the sleeve 303 is reduced, and the grooves provided can also accommodate the squeezed volume of the sleeve 303, reduce the overall thickness of the sleeve 303, increase the elasticity of the sleeve 303, and achieve close contact with the first boring bar 1. At the same time, the first boring bar 1 is held tightly by changing the inner diameter of the sleeve 303, so that the thickness of the sleeve 303 is uniform, and the first boring bar 1 and the second boring bar 2 are effectively ensured to be coaxially arranged.

[0057] In another preferred embodiment, Figure 8 As shown, the sleeve 303 is provided with a staggered opening structure at intervals along the circumferential direction. Similarly, under the extrusion of its peripheral mechanism, the opening cross-sections are attached to each other, the inner diameter of the overall structure of the sleeve 303 is reduced, and then the first boring bar 1 is tightly embraced to achieve the fixation of the first boring bar 1.

[0058] Furthermore, during the deep hole machining process, the machining area needs to be cooled. The usual method is to inject coolant into the machining area through a hollow boring bar. In one embodiment of the present application, the first boring bar 1 and the second boring bar 2 both adopt a hollow structure, and the end of the second boring bar 2 away from the jacket 3 is connected to the oiler. The coolant flows from the second boring bar 2 to the first boring bar 1. Therefore, a seal 304 needs to be provided to close the first through hole of the jacket body 301 to prevent the coolant from overflowing from the jacket body 301.

[0059] Specifically, a seal 304 is provided at the annular step at the junction of the large diameter hole and the small diameter hole of the first through hole 1, and the outer peripheral wall surface of the seal 304 matches the inner peripheral wall surface of the annular step of the jacket body 301, and a through hole is opened to match the first boring bar 1. In addition, Figure 9 As shown, a sealing groove is provided on the outer peripheral wall surface of the seal 304 in the annular direction and / or a sealing groove is provided on the inner peripheral wall surface of the annular step of the jacket casing 301 in the annular direction; a corresponding sealing ring is provided in each sealing groove, which is used to achieve the sealing between the seal 304 and the inner peripheral wall surface of the annular step of the jacket casing 301. Furthermore, the sealing groove can be multiple, preferably two, arranged at intervals along the axial direction. In addition, a corresponding sealing groove is also provided on the inner peripheral wall surface of the seal 304 to set a corresponding sealing ring, so that the seal 304 and the first boring bar 1 are completely sealed. In addition, a sealing ring or a sealing gasket structure is also provided at the threaded connection between the second boring bar 2 and the jacket casing 301 to achieve the sealing between the second boring bar 2 and the jacket casing 301.

[0060] In one embodiment, there is a certain gap between the first through hole of the jacket body 301 and the first boring bar 1, such that a top ring 4 can be axially spaced between the first boring bar 1 and the second boring bar 2, as Figure 10 shown. The top ring 4 is an annular member, whose outer peripheral wall surface fits with the inner peripheral wall surface of the second boring bar 2, its inner peripheral wall surface fits with the first boring bar 1, and the top ring 4 is of a rigid structure. The top ring 4 is sleeved on the first boring bar 1, and the relative positions of the first boring bar 1 and the second boring bar 2 are fixed by the top ring 4, enhancing the overall rigidity strength of the boring bar structure. Further, screw holes are axially spaced on the top ring 4, and the screw holes are preferably countersunk holes to ensure that the head of the screw does not protrude beyond the outer peripheral wall surface of the top ring 4, so as to ensure that the top ring 4 fits with the inner peripheral wall surface of the second boring bar 2 and avoid the phenomenon that the head of the screw abuts against the inner peripheral wall surface of the second boring bar 2 and then scratches the inner peripheral wall surface of the second boring bar 2. It should be noted that the number of axially spaced top rings 4 is related to the length of the first boring bar 1 inside the hollow of the second boring bar 2. When the first boring bar 1 extends deep into the second boring bar 2, multiple groups of top rings 4 can be set to ensure the overall rigidity strength of the boring bar and avoid relative loosening between the first boring bar 1 and the second boring bar 2 due to self-weight.

[0061] Furthermore, a laser rangefinder or other ranging devices can be additionally provided on the jacket 3. By emitting laser or other ranging signals, the distance between the end of the first boring bar 1 far from the second boring bar 2 (i.e., the end of the first boring bar 1 connected to the cutting head) and the jacket can be detected, so as to accurately determine the extended rod length of the first boring bar 1 and achieve precise adjustment of the boring bar rod length.

[0062] Specifically, in one embodiment, taking a deep hole drilling and boring machine (model H9 - 0186000mm d320x) with a machine tool stroke of 6m as an example, the machine tool includes a tailstock and a steady rest. The specification of the first boring bar 1 is 3.5m / section, the specification of the second boring bar 2 is 1.7m / section. A boring head is provided at the end of the first boring bar 1 far from the jacket 3, and one end of the second boring bar 2 far from the jacket 3 is connected to the oil feeder in the tailstock.

[0063] In a specific application scenario, the machining stroke of the workpiece to be processed is 2m. According to the above boring bar assembly specifications, it can be judged that the combination of 1 section of the first boring bar 1 and 1 section of the second boring bar 2 can meet the machining stroke, and the extended length of the first boring bar 1 is slightly greater than 2m. On this basis, a boring head is provided at one end of the first boring bar 1, and the top ring 4 is provided within a range of 1.4m from the other end. The end of the first boring bar 1 with the top ring 4 extends into the hollow inside the second boring bar 2, and at the same time, it is ensured that the boring head is more than 2m away from the jacket 3. After the rod length adjustment work is completed, the jacket 3 tightly connects the first boring bar 1 and the second boring bar 2.

[0064] It should be further noted that in the above application scenario, one section of the first boring bar 1 and the second boring bar 2 is sufficient to meet the required machining stroke. However, in other application scenarios with large machining strokes, multiple sections of the first boring bar 1 or / and the second boring bar 2 need to be selected for combination. Therefore, corresponding internal helical and external helical structures are respectively provided at both ends of the first boring bar 1 and the second boring bar 2, enabling the boring bars of each section to be helically matched and connected to each other to meet the needs of large machining strokes.

[0065] A method for quickly adjusting the length of a boring bar based on the present invention includes the following steps:

[0066] S1: The boring machine mechanism stops, the coolant injector stops injecting coolant, and the machine stops rotating;

[0067] S2: Loosen the connecting bolts of the clamping block 302 and the jacket body 301, and remove the clamping block 302;

[0068] S3: The sleeve 303 resumes its original state without external extrusion, and there is a gap between the first boring bar 1 and the sleeve 303, allowing the first boring bar to perform reciprocating motion along the axial direction;

[0069] S4: Remove the first boring bar 1 and the seal 304;

[0070] S5: Set the corresponding top ring 4 according to the length of the first boring bar 1 inside the second boring bar 2;

[0071] S6: Reset the length of the boring bar, install the seal 304, and adjust the circumferential relative position of the first boring bar 1;

[0072] S7: Adjust the sleeve 303 to the corresponding position, tightly connect the clamping block 302 and the jacket body 301, and the adjustment of the overall length of the boring bar is completed.

[0073] The combined boring bar with the function of adjusting the bar length in the present invention is composed of a first boring bar, a second boring bar, and a jacket. One end of the jacket is fixedly connected to the second boring bar, and the other end is tightly connected to the first boring bar through a clamping assembly (composed of a clamping block and a corresponding pre-tightening module). When the overall length of the boring bar needs to be adjusted accordingly, the jacket switches to the loose state, and the first boring bar performs reciprocating motion in the hollow interior of the jacket and the second boring bar to achieve the adjustment of the overall length of the boring bar. Such an adjustment method increases the selection range of the boring bar length. Moreover, corresponding sealing structures are provided at the joints of the jacket with the first boring bar and the second boring bar to ensure that the coolant injected from the second boring bar does not overflow from these joints. At the same time, top rings are arranged at intervals along the axial direction on a part of the first boring bar extending into the second boring bar, and the top rings are in contact with the inner peripheral wall surface of the second boring bar to stabilize the relative position relationship between the first boring bar and the second boring bar, avoid relative loosening, and enhance the strength of the overall boring bar.

[0074] Those skilled in the art can easily understand that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A combined boring bar with a bar length adjustment function, comprising a first boring bar and a second boring bar, It is characterized in that Also includes jacket: A first through hole is formed in the middle of the jacket, one end of which is fixedly connected to the second boring bar, and the other end is used for the first boring bar to be coaxially embedded, and a second through hole is formed in the middle of the second boring bar along the axial direction, and the inner diameter of the second through hole is larger than the outer diameter of the first boring bar, so that the end of the first boring bar can coaxially extend into the second through hole; and The end of the sleeve is provided with a locking notch to match the first boring bar, and a clamping assembly is provided corresponding to the locking notch, so that when the clamping assembly is connected to the locking notch, the first boring bar embedded in the first through hole can be clamped and locked in the sleeve, and the length of the combined boring bar can be adjusted by loosening or tightening the clamping assembly and axial displacement of the first boring bar in the sleeve; The first through hole is a stepped hole, which includes a small-diameter hole provided at one end of the second boring bar and a large-diameter hole radially connected to the locking notch; The end of the first boring bar extends into the second through hole of the second boring bar; The portion of the first boring bar located inside the second boring bar is provided with a top ring, the top ring is sleeved on the first boring bar, and the outer peripheral wall of the top ring is in contact with the inner wall surface of the second boring bar to prevent the first boring bar from shaking inside the second boring bar.

2. The combined boring bar with rod length adjustment function according to claim 1, in, The clamping assembly comprises a clamping block which can be matched and connected to the locking notch, and the inner peripheral wall surface of the clamping block is an arc surface.

3. The combined boring bar with rod length adjustment function according to claim 2, in, The inner peripheral wall surface of the clamping block is pressed against the outer peripheral wall surface of the first boring bar, so that the outer peripheral wall surface of the first boring bar facing away from the clamping block is pressed against the inner peripheral wall surface of the first through hole.

4. The combined boring bar with rod length adjustment function according to claim 3, in, A plurality of protrusions are arranged on the inner peripheral wall surface of the clamping block or an elastic gasket is arranged between the clamping block and the first boring bar.

5. The combined boring bar with rod length adjustment function according to claim 2, in, The clamping assembly includes a sleeve sleeved on the outer periphery of the first boring bar, and the sleeve is arranged at the large diameter hole connected to the locking notch. When the clamping block is matched and docked with the locking notch, the sleeve provides a pre-tightening force to achieve locking of the first boring bar by the sleeve.

6. The combined boring bar with rod length adjustment function according to claim 5, in, A sealing member is provided between the first through hole and the first boring bar, for sealing the gap therebetween; The sealing member is arranged at the annular step at the junction of the large-diameter hole and the small-diameter hole; or an annular groove is opened along the annular direction on the inner peripheral wall surface of the first through hole, so that the sealing member is embedded in the annular groove.

7. The combined boring bar with rod length adjustment function according to claim 6, in, The inner wall surface and the outer peripheral surface of the seal are circumferentially provided with seal grooves, and sealing rings are respectively arranged in the seal grooves to achieve the sealing of the gap between the seal and the first boring bar and the seal at the through hole of the collet.

8. The combined boring bar with the function of adjusting the rod length according to claim 1, wherein, The top ring is circumferentially provided with a plurality of through holes, and the top ring is fixed on the first boring bar through fasteners, and the fasteners do not protrude above the outer peripheral wall surface of the top ring.

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