Main shaft structure, electric main shaft and machine tool

Abstract

The utility model discloses a main shaft structure, motorized spindle and machine tool, including shaft core and taper hole seat, the shaft core extends from the tail end to the nose end along the axial direction, the inside of shaft core is provided with shaft core inner bore, the taper hole seat and the shaft core are arranged in a split way, the taper hole seat is fixedly connected to the nose end of the shaft core, and the shaft core is provided with the shaft core inner bore. The taper hole seat is provided with a cutter handle installation hole communicated with the shaft core inner hole, and a hard layer is arranged on the surface layer of the cutter handle installation hole. The nose end of the shaft core is divided into the shaft core to be matched with the taper hole base, the separated taper hole base can achieve local surface modification, the abrasion resistance of the binding face of the pull claw is improved, and the service life of the taper hole base is prolonged while the precision of the main shaft broach is guaranteed.

Description

Technical Field

[0001] The utility model is used in the field of mechanical equipment, in particular to a spindle structure, an electric spindle and a machine tool. Background Art

[0002] Friction stir welding is the most eye-catching welding method since the advent of laser welding; its appearance has brought about a major change in the connection technology of non-ferrous metals such as aluminum alloys. The use of friction stir welding to weld aluminum alloys has achieved very good results. Nowadays, friction stir welding of zinc, copper, titanium, low-carbon steel, composite materials, etc. is being carried out in the UK, the US and other countries. Friction stir welding has a good application prospect in the aerospace field.

[0003] Friction stir welding uses the heat generated by the friction between the high-speed rotating welding tool and the workpiece to partially melt the material to be welded. When the welding tool moves forward along the welding interface, the plasticized material flows from the front to the back of the welding tool under the action of the rotating friction of the welding tool, and forms a dense solid phase weld under the extrusion of the welding tool. During the welding process, the workpiece must be rigidly fixed on the backing pad, and the welding head rotates at high speed while moving relative to the workpiece along the seam of the workpiece. In the current mechanical processing field, the pursuit of workpiece processing effects is constantly improving. Friction stir welding does not require complex pretreatment, has strong operability, low residual stress, and good welding performance.

[0004] Friction stir welding uses the friction heat between the welding tool and the workpiece to partially melt the workpiece to be welded, and then the welded parts are welded together to achieve the processing purpose. During the operation of the spindle, the axial force and radial force borne by the spindle nose are particularly large, so the taper hole of the spindle nose is greatly worn. After long-term or multiple processing, the spindle nose may rust, stress corrosion, deformation, wear, surface peeling and other abnormal conditions. For traditional shaft core structures, this situation can only be scrapped or the shaft core replaced. Either solution is time-consuming, labor-intensive and costly. Utility Model Content

[0005] The purpose of the utility model is to solve at least one of the technical problems existing in the prior art, and to provide a spindle structure, an electric spindle and a machine tool, in which the nose end of the shaft core is divided into a shaft core and a tapered hole seat. The separated tapered hole seat can achieve local surface modification, thereby improving the wear resistance of the claw contact surface, thereby increasing the service life of the tapered hole seat while ensuring the accuracy of the spindle broach.

[0006] The technical solution adopted by the utility model to solve its technical problems is:

[0007] In the first aspect, a spindle structure includes a shaft core and a tapered hole seat, wherein the shaft core extends axially from the tail end to the nose end, the shaft core is provided with a shaft core inner hole, the tapered hole seat is separately arranged from the shaft core, the tapered hole seat is fixedly connected to the nose end of the shaft core, the tapered hole seat is provided with a tool handle mounting hole connected to the shaft core inner hole, and the surface of the tool handle mounting hole is provided with a hard layer.

[0008] In combination with the first aspect, in certain implementations of the first aspect, the nose end of the shaft core is provided with an embedding groove extending toward the tail end, and the tapered hole seat is assembled in the embedding groove by interference fit.

[0009] In combination with the first aspect and the above-mentioned implementations, in certain implementations of the first aspect, one end of the tapered hole seat is exposed from the embedding groove and is provided with a radially outwardly turned convex edge, and the convex edge is locked to the nose end face of the shaft core by a fastener.

[0010] In combination with the first aspect and the above-mentioned implementation methods, in certain implementation methods of the first aspect, the main shaft structure also includes a tail end bearing seat and a nose end bearing seat, the shaft core is supported on the tail end bearing seat through a tail end bearing, the shaft core is supported on the nose end bearing seat through a nose end bearing, the tail end of the shaft core is provided with a bearing pressure cover for pressing the inner ring of the tail end bearing, the nose end of the shaft core is provided with a bearing pressure ring for pressing the inner ring of the nose end bearing, the bearing pressure ring is sleeved on the shaft core, and is locked by the convex edge of the tapered hole seat on the outside.

[0011] In combination with the first aspect and the above-mentioned implementation methods, in certain implementation methods of the first aspect, the nose end bearing seat is provided with an end cover for pressing the outer ring of the nose end bearing, and the end cover is matched with the bearing pressure ring and the convex edge clearance of the tapered hole seat to form a labyrinth sealing structure.

[0012] In combination with the first aspect and the above-mentioned implementations, in some implementations of the first aspect, the shaft core is provided with an air inlet hole extending to the tapered hole seat, and the tapered hole seat is provided with an air outlet hole docked with the air inlet hole.

[0013] In combination with the first aspect and the above-mentioned implementations, in some implementations of the first aspect, the air outlet includes a first air outlet and a second air outlet, the first air outlet extends to the shank mounting hole, and the second air outlet extends to the end surface of the tapered hole seat.

[0014] In combination with the first aspect and the above-mentioned implementations, in some implementations of the first aspect, a check valve is provided between the shaft core and the tapered hole seat at a position where the air inlet and the air outlet are butted.

[0015] In a second aspect, an electric spindle comprises the spindle structure described in any implementation of the first aspect.

[0016] In a third aspect, a machine tool comprises the electric spindle described in any implementation of the second aspect.

[0017] One of the above technical solutions has at least one of the following advantages or beneficial effects: In the technical solution of the utility model, a split tapered hole seat is adopted. The split tapered hole seat breaks the tradition that the shaft core directly contacts the fixture, and separates the tapered hole seat from the shaft core by cutting the clearance position below the claw mating surface. This design separates the claw mating surface that can only be turned out for grinding to obtain a better quality inclined surface. At the same time, the use of a split tapered hole seat is also convenient for modifying its surface to form a hard layer. Compared with the original shaft core structure, the split tapered hole seat is easier to perform local heat treatment or coating, and the strength, hardness and processing quality of the end face of the shaft system are guaranteed. Moreover, there is a gap between the split tapered hole seat and the shaft core, and the stress generated during the processing can be released at the gap, providing a guarantee for safe processing.

[0018] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0020] Figure 1 It is a schematic structural diagram of an embodiment of the electric spindle of the utility model. DETAILED DESCRIPTION

[0021] This section will describe in detail the specific embodiments of the utility model. The preferred embodiments of the utility model are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the utility model, but it cannot be understood as a limitation on the protection scope of the utility model.

[0022] In the present invention, if directions (up, down, left, right, front and back) are described, it is only for the convenience of describing the technical solution of the present invention, and does not indicate or imply that the technical features referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0023] In the present utility model, "several" means one or more, "multiple" means more than two, "greater than", "less than", "exceed" and the like are understood to exclude the number itself; "above", "below", "within" and the like are understood to include the number itself. In the description of the present utility model, if there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0024] In the present invention, unless otherwise clearly defined, the words "set", "install", "connect" and the like should be understood in a broad sense, for example, they can be directly connected or indirectly connected through an intermediate medium; they can be fixedly connected or detachably connected or integrally formed; they can be mechanically connected or electrically connected or able to communicate with each other; they can be the internal connection of two elements or the interaction relationship between two elements. Those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0025] See also Figure 1 The embodiment of the utility model provides a spindle structure, including a shaft core 100 and a tapered hole seat 200. The shaft core 100 extends axially from the tail end to the nose end. The shaft core 100 is provided with a shaft core inner hole 101. The tapered hole seat 200 is separately arranged from the shaft core 100. The tapered hole seat 200 is fixedly connected to the nose end of the shaft core 100. The tapered hole seat 200 is provided with a tool handle mounting hole 201 connected to the shaft core inner hole 101. The tool handle mounting hole 201 is used as a position for connecting the tool handle. The greater the clamping force of the tool handle, the higher the requirements for the claw and the tool handle mounting hole 201; for the tool handle mounting hole 201, the most serious loss is the inclined surface that fits with the claw. The greater the clamping force of the tool handle, the more serious the wear on the claw fitting surface. In order to improve product performance, the surface of the tool handle mounting hole 201 is provided with a hard layer. The hard layer can be formed by quenching or carburizing or coating to improve its wear resistance.

[0026] In the technical solution of the utility model, a split tapered hole seat 200 is adopted. The structure is composed of the nose end of the shaft core 100 and the tapered hole seat 200, which are part of the shaft core 100 assembly. The tapered hole seat 200 replaces the nose end of the shaft core 100 to bear the wear from the tool and the claw. The split tapered hole seat 200 breaks the tradition of the shaft core 100 directly contacting the fixture. The avoidance position below the claw mating surface is separated from the shaft core 100 to separate the tapered hole seat 200. This design separates the claw mating surface that can only be turned out by lathing to obtain a better quality inclined surface by grinding. In other words, the separated tapered hole seat 200 is smaller in size than the original shaft system, and the claw mating surface that can only be fine-turned can now be processed with higher precision without structural restrictions. At the same time, the use of the split tapered hole seat 200 is also convenient for modifying its surface to form a hard layer. Compared with the original shaft core 100 structure, the split tapered hole seat 200 is easier to perform local heat treatment or coating, and the strength, hardness and processing quality of the end face of the shaft system are guaranteed. Moreover, there is a gap between the split tapered hole seat 200 and the shaft core 100, and the stress generated during the processing can be released at the gap, providing a guarantee for safe processing.

[0027] In some embodiments, see Figure 1 The nose end of the shaft core 100 is provided with an embedding groove 102 extending toward the tail end, and the tapered hole seat 200 is assembled in the embedding groove 102 by interference fit. The coaxiality of the shaft core 100 and the tapered hole seat 200 is ensured by the interference fit connection structure, and the processing accuracy can be guaranteed to a certain extent even if the processing intensity is very high.

[0028] For further information, see Figure 1 One end of the tapered hole seat 200 is exposed from the embedding groove 102 and is provided with a radially outward-turned convex edge 103. The convex edge 103 is locked to the nose end face of the shaft core 100 by a fastener. This embodiment adopts interference fit + screw locking to ensure the axial stiffness and radial load of the main shaft.

[0029] In some embodiments, see Figure 1 The spindle structure also includes a tail end bearing seat 300 and a nose end bearing seat 400. The shaft core 100 is supported on the tail end bearing seat 300 through a tail end bearing 301. The shaft core 100 is supported on the nose end bearing seat 400 through a nose end bearing 401. The spindle structure is provided with a motor assembly between the tail end bearing seat 300 and the nose end bearing seat 400. The shaft core 100 rotates under the drive of the motor assembly, further driving the tool at the nose end.

[0030] See also Figure 1A bearing pressure cover 500 is provided at the tail end of the shaft core 100 to press the inner ring of the tail end bearing 301, and a bearing pressure ring 600 is provided at the nose end of the shaft core 100 to press the inner ring of the nose end bearing 401. The bearing pressure ring 600 is sleeved on the shaft core 100 and locked by the convex edge 103 of the outer tapered hole seat 200 to realize bearing preload.

[0031] For further information, see Figure 1 The nose end bearing seat 400 is provided with an end cover 700 for pressing the outer ring of the nose end bearing 401. The end cover 700 is matched with the bearing pressure ring 600 and the convex edge 103 of the tapered hole seat 200 to form a labyrinth sealing structure, thereby improving the sealing effect of the nose end of the main shaft structure and preventing impurities from entering the interior of the main shaft structure.

[0032] Including but not limited to stir friction welding electric spindles, it is difficult to avoid impurities sticking to the conical surface or end surface of the tapered hole in many machine tools during complex processing. This situation not only affects the accuracy of the processed workpiece, but also affects the service life of the spindle or tool holder. In view of this, in some embodiments, see Figure 1 The shaft core 100 is provided with an air inlet 800 extending to the tapered hole seat 200, and the tapered hole seat 200 is provided with an air outlet connected to the air inlet 800. Compressed air enters from the top cover of the oil cylinder, enters the shaft core 100 through the piston and the pull rod, and then escapes from the shaft core 100 and blows out through the split tapered hole seat 200, preventing fine chips or other impurities generated during tool change from adhering to the tapered hole seat 200.

[0033] For further information, see Figure 1 The air outlet includes a first air outlet 901 and a second air outlet 902. The first air outlet 901 extends to the tool handle mounting hole 201, and the second air outlet 902 extends to the end surface of the tapered hole seat 200. The airflow of the first air outlet 901 can clean the conical surface of the main shaft rotating shaft core 100, and the airflow of the second air outlet 902 can clean the end surface of the main shaft rotating shaft core 100. This embodiment can clean the conical surface and the end surface of the rotating shaft core 100 at the same time, greatly improving the performance of the main shaft dust blowing.

[0034] The cone hole cleaning function is crucial for high-precision machining. The cone hole seat 200 is kept clean by blowing air inside the spindle to ensure that there are no impurities between the cone hole and the tool. The fit between the tool and the cone hole is not affected by impurities, which means that the accuracy of the spindle is also not affected. In addition to ensuring the cleanliness of the cone hole, the cone hole cleaning function also plays a role in cooling the shaft core 100 to a certain extent.

[0035] In some embodiments, see Figure 1 A check valve 903 is provided between the shaft core 100 and the tapered hole seat 200 at the position where the air inlet 800 and the air outlet are connected. The check valve 903 can effectively prevent the coolant from flowing back during the processing.

[0036] An embodiment of the utility model further provides an electric spindle, comprising the spindle structure in any one of the above embodiments.

[0037] An embodiment of the utility model further provides a machine tool, comprising the electric spindle in any one of the above embodiments.

[0038] In the description of this specification, the description with reference to the terms "example", "embodiment" or "some embodiments" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0039] Of course, the invention is not limited to the above-mentioned embodiments, and those skilled in the art may make equivalent modifications or substitutions without violating the spirit of the invention, and these equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A spindle structure, characterized in that: It includes an axis core and a tapered hole seat, the axis core extends axially from the tail end to the nose end, the axis core is provided with an axis core inner hole, the tapered hole seat is separately arranged from the axis core, the tapered hole seat is fixedly connected to the nose end of the axis core, the tapered hole seat is provided with a tool handle mounting hole connected to the axis core inner hole, and the surface of the tool handle mounting hole is provided with a hard layer.

2. The spindle structure according to claim 1, characterized in that: The nose end of the shaft core is provided with an embedding groove extending toward the tail end, and the tapered hole seat is assembled in the embedding groove by interference fit.

3. The spindle structure according to claim 2, characterized in that: One end of the tapered hole seat is exposed from the embedding groove and is provided with a radially outwardly turned convex edge, and the convex edge is locked to the nose end surface of the shaft core through a fastener.

4. The spindle structure according to claim 3, characterized in that: The main shaft structure also includes a tail end bearing seat and a nose end bearing seat, the shaft core is supported on the tail end bearing seat through a tail end bearing, the shaft core is supported on the nose end bearing seat through a nose end bearing, the tail end of the shaft core is provided with a bearing pressure cover for pressing the inner ring of the tail end bearing, the nose end of the shaft core is provided with a bearing pressure ring for pressing the inner ring of the nose end bearing, the bearing pressure ring is sleeved on the shaft core and locked by the convex edge of the tapered hole seat on the outside.

5. The spindle structure according to claim 4, characterized in that: The nose end bearing seat is provided with an end cover for pressing the outer ring of the nose end bearing, and the end cover is matched with the bearing pressure ring and the convex edge clearance of the tapered hole seat to form a labyrinth sealing structure.

6. The spindle structure according to claim 1, characterized in that: The shaft core is provided with an air inlet hole extending to the tapered hole seat, and the tapered hole seat is provided with an air outlet hole docking with the air inlet hole.

7. The spindle structure according to claim 6, characterized in that: The air outlet hole includes a first air outlet hole and a second air outlet hole, the first air outlet hole extends to the tool handle mounting hole, and the second air outlet hole extends to the end surface of the tapered hole seat.

8. The spindle structure according to claim 6, characterized in that: A check valve is provided between the shaft core and the tapered hole seat at a position where the air inlet and the air outlet are butted against each other.

9. An electric spindle, characterized in that: A main shaft structure comprising any one of claims 1 to 8.

10. A machine tool, characterized in that: Includes the electric spindle as claimed in claim 9.

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