Numerically controlled machine tool spindle box

Abstract

The present application relates to numerical control machine tool parts, especially numerical control machine tool spindle box, including upper bearing seat, lower bearing seat, the upper bearing seat and lower bearing seat between being provided with thermal stress buffer connecting piece, the thermal stress buffer connecting piece includes the support plate that is integrally formed between the upper bearing seat and lower bearing seat, the support plate cross section is arc, the radian angle that the support plate is connected with upper bearing seat, lower bearing seat is greater than 180 DEG, integrally formed thermal stress buffer connecting piece, in the process of using, bearing part generates heat and then is given other components, because the upper bearing seat and lower bearing seat are integrally cast with the support plate and are formed, and the crystal phase organization is uniform, when local heating occurs, stress can be uniformly diffused outward, and then the deformation amount is reduced, and then the coaxiality of the upper bearing seat and lower bearing seat is guaranteed, the bearing jumps if in the process of high speed rotation, accordingly, the temperature rise speed is slow, and the service life is long.

Description

TECHNICAL FIELD

[0001] The present application relates to numerical control machine tool parts, in particular to a numerical control machine tool spindle box. BACKGROUND

[0002] Numerical control machine tools are high-precision equipment used in mechanical processing. According to the stroke setting, parts are drilled, ground, etc. The yield is high. For castings such as hubs, shift forks, shafts, gearboxes, etc., after casting, the workpiece with a connecting part is obtained after machining, and then treated with anti-rust, etc. to obtain finished parts.

[0003] The spindle box is part of the machine head. The spindle is supported by the spindle box, which ensures stable tool head feeding. The spindle is driven and positioned by the spindle box. In general, the lubrication, heat dissipation and structural stability of the spindle box need to be ensured. The existing transmission spindle box for large numerical control machine tools is cast and then processed. The box is large and usually connected to a lubricating oil circulating pump to ensure the stability of the lubrication and cooling effect. The spindle box for small numerical control machine tools, such as the numerical control machine tool spindle box for drilling and grinding shift forks, mainly includes an upper bearing seat and a lower bearing seat. The upper bearing seat and the lower bearing seat are fixed on the machine head after adjusting the position and fixing. The spindle is supported, or the upper bearing and the lower bearing are fixed on the support frame to support the spindle. The spindle is cooled by air cooling or water cooling. For numerical control machine tools with higher precision requirements, precision control is achieved through error compensation. The spindle box of the existing small numerical control machine tool has poor positioning effect due to thermal stress after temperature rise. In the case of high-speed rotation of the spindle, the jumping intensity gradually increases, and the stability of the numerical control lathe decreases. SUMMARY

[0004] The purpose of the present application is to overcome the shortcomings of the prior art and provide a numerical control machine tool spindle box that eliminates thermal stress through one-piece molding and has good lubrication and heat dissipation effects.

[0005] The present application is achieved by the following technical scheme: a numerical control machine tool spindle box, comprising an upper bearing seat and a lower bearing seat, a thermal stress buffer connecting piece is arranged between the upper bearing seat and the lower bearing seat, the thermal stress buffer connecting piece comprises a support plate integrally formed between the upper bearing seat and the lower bearing seat, the support plate is arc-shaped in cross section, the angle of curvature of the support plate connected with the upper bearing seat and the lower bearing seat is greater than 180°, a rib plate is integrally formed on the side surface of the support plate along the length direction, a connecting plate is arranged on the rib plate, a heat dissipation cavity is arranged at the opening of the support plate, and the upper bearing seat, the lower bearing seat, the support plate and the rib plate are subjected to heat treatment after forming.

[0006] Further, the support plate is a single support plate, the arc angle of the single support plate connected with the upper bearing seat and the lower bearing seat is 220-260°, the heat conduction plate is arranged at the heat dissipation cavity, the oil cavity is formed between the heat conduction plate and the single support plate, the spacing value between the side wall of the oil cavity and the main shaft is 2-4 times of the spacing value between the single support plate and the main shaft, and the heat conduction plate is connected with the lubricating oil circulating device.

[0007] Further, the lubricating oil circulating device comprises vertical grooves arranged on the heat conduction plate, lubricating oil can flow downward along the grooves, and the inner wall of the grooves is provided with a pattern for reducing the flow speed of the lubricating oil.

[0008] Further, the lubricating oil circulating device comprises a circulating pipe arranged outside the heat conduction plate, the upper end of the circulating pipe is in communication with the upper end of the oil cavity, the lower end of the circulating pipe is in communication with the lower end of the oil cavity, the circulating pipe is provided with an upward conveying paddle, the conveying paddle is connected with a rotating driving device, the rotating driving device comprises a roller arranged on the rib plate, and the roller rotates in the moving process of the main shaft box.

[0009] Further, the support plate is composed of two symmetrical single plates, the arc angle of any single plate connected with the upper bearing seat and the lower bearing seat is 90-120°, the rib plate is connected with one of the single plates, and the oil cavity is arranged between the support plate and the upper bearing seat and the lower bearing seat.

[0010] Further, the oil cavity is located at the end of the support plate, and the heat conduction oil baffle is connected with the oil cavity.

[0011] Further, the heat dissipation cavity is provided with a heat conduction plate, the oil cavity is formed between the heat conduction plate and the single plate, and the spacing value between the side wall of the oil cavity and the main shaft is 2-4 times of the spacing value between the single plate and the main shaft.

[0012] Further, the upper bearing seat and the lower bearing seat are connected with the cooling device.

[0013] The beneficial effect of the present application is that: the numerical control machine tool spindle box, including the upper bearing seat, the lower bearing seat, the upper bearing seat and the lower bearing seat are provided with thermal stress buffer connecting piece, the thermal stress buffer connecting piece includes the support plate which is integrally formed between the upper bearing seat and the lower bearing seat, the support plate cross section is arc, the radian angle of the support plate and the upper bearing seat, lower bearing seat connection is greater than 180 DEG, the support plate side is integrally formed with the rib plate along the length direction, the rib plate is provided with the connecting plate, the opening of the support plate is provided with the heat dissipation cavity, the upper bearing seat, lower bearing seat and support plate, rib plate are formed after heat treatment, integrally formed thermal stress buffer connecting piece, in the process of using, bearing part generates heat and then transfers to other components, because the upper bearing seat and the lower bearing seat are integrally cast with the support plate, the crystal phase organization is uniform, when local heating occurs, stress can be uniformly diffused outward, thereby reducing the deformation amount, thereby ensuring the coaxiality of the upper bearing seat and the lower bearing seat, the bearing jumps if in the process of high speed rotation, accordingly, the temperature rise speed is slow, and the service life is long. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is the front view schematic diagram of example 1;

[0015] Figure 2 It is the structure schematic diagram of example 1;

[0016] Figure 3 It is the front view schematic diagram of example 2;

[0017] Figure 4 It is the front view schematic diagram of example 2 lower bearing seat;

[0018] Figure 5 It is the support plate cross section schematic diagram of example 2;

[0019] Figure 6 It is the support plate cross section schematic diagram of example 3;

[0020] Figure 7 It is the front view schematic diagram of example 4;

[0021] Figure 8 It is the front view schematic diagram of example 4;

[0022] Wherein: 1, support plate;2, upper bearing seat;3, lower bearing seat;4, conical oil groove;5, heat conduction plate;6, rib plate;7, connecting plate;8, oil cavity;9, bearing gland;10, main shaft;11, heat conduction oil retaining plate;12, circulating pipe;13, delivery paddle;14, connecting shaft;15, roller;16, transmission belt;17, driven wheel;18, guide boss. DETAILED DESCRIPTION

[0023] In the description of the present application, it is also necessary to explain that, unless otherwise explicitly specified and limited, the terms "arrange", "install", "connect", "connect" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0024] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0025] Embodiment 1

[0026] As Figures 1-2 shown, a numerical control machine tool spindle box, including the upper bearing seat 2, the lower bearing seat 3, the upper bearing seat and the lower bearing seat are integrally cast into shape with thermal stress buffer connecting piece, in the embodiment, the thermal stress buffer connecting piece includes the support plate 1 integrally cast between the upper bearing seat and the lower bearing seat, the specific use of the brand 08F boiling steel, it is generally believed that the use of high hardness steel can improve the deformation resistance, in the test, first select high speed steel, compared with the spindle box obtained by positioning installation, test by monitoring the temperature upper limit 80℃, the use time is greatly improved, the preliminary expected effect is achieved, then test the bearing steel, the use time is further improved, when continuing to test other steel, it is found that the use of the brand 08F boiling steel has the highest use time, it is preliminarily judged that the hardness of 08F is lower, and the absorption effect of vibration is better, therefore, the cast spindle box body is subjected to tempering heat treatment, the tempering temperature is 380-450℃, the hardness is further reduced, the use time is increased, when the tempering temperature is higher than 500℃, although the hardness is reduced, the use time is also reduced, the tempering heat treatment can also eliminate the thermal stress concentration generated in the casting process, after the tempering heat treatment, the outdoor placement is 6 months, the natural aging treatment is carried out, the thermal stress concentration generated in the casting process is further eliminated, after the tempering heat treatment and the natural aging treatment, the finishing is carried out, then the zinc plating is carried out, the rust prevention treatment is carried out, then the bearing, the spindle and other components are installed.

[0027] In terms of structure, the support plate is arc-shaped in cross section, and the angle of the arc connecting the support plate with the upper bearing seat and the lower bearing seat is greater than 180°. In this embodiment, the support plate is a single support plate, and the angle of the arc is 240°. An arc-shaped transition is integrally formed at the connection. The angle of the arc-shaped transition part is 5-10°, which can ensure sufficient connection area and uniform heat stress diffusion. The support plate is coaxial with the main shaft, and the distance between the support plate and the main shaft is 2-3 mm, which has little interference with the rotation of the main shaft and can ensure that the overall size of the main shaft box is small.

[0028] A rib plate 6 is integrally formed on the side surface of the support plate along the length direction. The rib plate extends to both ends of the support plate, which can improve the deformation resistance of the support plate. In general, process holes are uniformly processed on the rib plate. The total hole area of the process holes is 1 / 2 of the total area of the rib plate, which can play a shock-absorbing effect. Filling shock-absorbing materials (such as rubber) in the process holes can better absorb shock, but there is a risk of falling off during use, which requires additional fixing. A connecting plate 7 is installed on the rib plate, which is used to connect to the slide and then move on the machine table. The connecting plate is bolted with the rib plate, which can be angle-adjusted to compensate for processing errors.

[0029] A heat dissipation cavity is formed at the opening of the support plate. A heat conduction plate 5 is sealingly installed at the heat dissipation cavity. In this embodiment, the heat conduction plate is a galvanized plate with a thickness of 2 mm, which is convenient for bending and stamping processing. The heat conduction plate is sealingly connected with the support plate, and an oil cavity 8 is formed between the heat conduction plate and the single support plate. The distance between the side wall of the oil cavity and the main shaft is 2-4 times the distance between the single support plate and the main shaft, which can store oil on one side. In general, the cavities formed around the main shaft should be uniform to ensure that the main shaft is evenly stressed during rotation. In this application, the distance between the support plate and the main shaft is large, i.e. 2-3 mm, which has little effect on the rotation of the main shaft. Therefore, a lubricating oil with low viscosity, such as 0W-20 type engine oil, is selected to further weaken the effect of uneven cavities on the rotation of the main shaft. The heat conduction plate is connected with a lubricating oil circulating device. In this embodiment, the lubricating oil circulating device includes vertical grooves processed on the heat conduction plate. The lubricating oil can flow downward along the grooves. Ridges are processed on the inner wall of the grooves to reduce the flow speed of the lubricating oil. During use, due to the high-speed rotation of the main shaft, the lubricating oil attached to the main shaft splashes disorderly to the support plate and the heat conduction plate under the action of centrifugal force. Part of the lubricating oil splashes upward. Since the distance between the support plate and the main shaft is 2-3 mm, part of the lubricating oil gradually splashes to the upper bearing seat to lubricate the upper bearing. Regularly adding lubricating oil can ensure that the lubricating oil is sufficient to lubricate the upper bearing and the lower bearing. When the lubricating oil is in the oil cavity, it is concentrated along the inner wall of the heat conduction plate and then flows downward along the heat conduction plate to realize circulation. During the downward flow, the flow path is lengthened and the flow resistance is increased due to the ridges, which increases the heat exchange time and cools the lubricating oil, thereby improving the overall heat dissipation effect.

[0030] The upper bearing is installed in the upper bearing seat, and the lower bearing is installed in the lower bearing seat. A conical oil groove 4 is formed at the bottom of the upper bearing seat and the lower bearing seat, which can store lubricating oil after use. In the initial stage of the main shaft starting, the bearing has a rapid heating process, and the oil pressure is formed in the process of rapid temperature rise, so that the lubricating oil quickly enters the inside of the bearing. The bearing pressing cover 9 is installed at the outer end of the upper bearing seat and the lower bearing seat to protect the bearing.

[0031] Example 2

[0032] As shown in Figures 3-5 A numerical control machine tool spindle box, unlike example 1, the support plate 1 is composed of two symmetrical single plates. The radian angle of any single plate connected with the upper bearing seat 2 and the lower bearing seat 3 is 90-120°, and the specific selection is 120°. The rib plate is connected with one of the single plates. There is an oil cavity 8 between the support plate and the upper bearing seat and the lower bearing seat. The support plate is made of two single plates, which has higher symmetry. The oil cavity is located at the end of the support plate. The oil cavity is connected with the heat-conducting oil baffle 11. The heat dissipation cavity is formed between the single plates. Due to the space provided by the heat dissipation cavity, the oil baffle can be easily installed by first inserting it vertically between the two single plates and then rotating it to install it. The heat-conducting oil baffle is made of copper. A groove is preformed between the upper bearing seat and the lower bearing seat and the corresponding support plate, which cooperates with the heat-conducting oil baffle to form an oil cavity after the heat-conducting oil baffle is installed, which can store lubricating oil and prolong the maintenance period. In this case, the heat is concentrated, and high-strength heat dissipation is required at the upper bearing seat and the lower bearing seat. A cooling device is installed. The cooling device is selected to be water-cooled or air-cooled. The cooling device works continuously or intermittently.

[0033] Example 3

[0034] As shown in Figure 6 A numerical control machine tool spindle box, unlike example 2, a heat-conducting plate 5 is installed between the two single plates, and an oil cavity 8 is formed between the heat-conducting plate and the single plate. The distance between the oil cavity side wall and the main shaft is 2-4 times the distance between the single plate and the main shaft. Part of the lubricating oil moves upward along the gap between the single plate and the main shaft, and then falls along the heat-conducting plate, which can better dissipate heat, store more lubricating oil, and make the stress more uniform during the rotation of the main shaft.

[0035] Example 4

[0036] As shown in Figures 7-8As shown, a kind of numerical control machine tool spindle box, unlike embodiment 1, lubricating oil circulating device includes the circulation pipe 12 being communicated in the heat conduction plate outside, circulation pipe is stainless steel pipe, circulation pipe upper end is communicated with the upper end of oil cavity, circulation pipe lower end is communicated with the lower end of oil cavity, circulation pipe is equipped with the upward transport paddle 13, transport paddle is helical blade, and it has good lifting effect for lubricating grease (such as 1# butter), transport paddle is connected with rotating drive device, rotating drive device includes the roller being installed on the rib plate, roller rotates in the process of moving of spindle box, specifically, connecting shaft 14 is installed on the upper end and lower end of rib plate, roller 15 is equipped on connecting shaft, roller is connected with driving wheel, driving wheel and driven wheel 17 are installed at the end of transport paddle, transmission belt 16 is installed between driving wheel and driven wheel, guiding boss 18 is fixed on the outer wall of support plate, for guiding transmission belt, in the process of use, spindle box moves along track under the movement of slide, just install long strip plate in cooperation with roller along track, just drive transport paddle to rotate in the process of transverse movement, because lubricating grease itself has greater viscosity, the speed of downward flow is slower, to be able to very good lubrication and heat dissipation.

[0037] In summary, the embodiments 1-4 provided by the present application, numerical control machine tool spindle box, including upper bearing seat, lower bearing seat, upper bearing seat and lower bearing seat integrally formed with thermal stress buffer connecting piece, thermal stress buffer connecting piece includes support plate integrally formed between upper bearing seat and lower bearing seat, the arc angle of support plate and upper bearing seat, lower bearing seat connection is greater than 180 °, support plate side is integrally formed with rib plate along the length direction, connecting plate is installed on the rib plate, the opening of support plate is formed with heat dissipation cavity, after forming, upper bearing seat, lower bearing seat and support plate, rib plate are heat treated, integrally formed thermal stress buffer connecting piece, in the process of use, bearing part generates heat and then transmits to other components, because upper bearing seat and lower bearing seat are integrally cast with support plate, crystal phase organization is uniform, when local heating occurs, stress can be uniformly diffused outward, to reduce deformation, to ensure the coaxiality of upper bearing seat and lower bearing seat, if bearing jumps in the process of high-speed rotation, corresponding, temperature rise speed is slow, and service life is long.

[0038] Finally, it should be noted that: the above only for the preferred embodiments of the present application, and not for limiting the present application, although the present application is described in detail with reference to the foregoing embodiments, for those skilled in the art, it still can modify the technical solutions recorded in the foregoing embodiments, or equivalent replacement to part of technical features, any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application, should be included in the protection scope of the present application.

Claims

1. A CNC machine tool headstock comprising an upper bearing block, a lower bearing block, characterized in that, The upper bearing seat and the lower bearing seat are provided with a thermal stress buffering connector, which comprises a support plate integrally formed between the upper bearing seat and the lower bearing seat, the support plate is arc-shaped in cross section, the radian angle of the support plate connected with the upper bearing seat and the lower bearing seat is greater than 180°, the side surface of the support plate is integrally formed with a rib plate along the length direction, the rib plate is provided with a connecting plate, the opening of the support plate is provided with a heat dissipation cavity, the upper bearing seat, the lower bearing seat, the support plate and the rib plate are subjected to heat treatment after being formed, The support plate is a single support plate, the distance between the single support plate and the main shaft is 2-3mm, the radian angle of the single support plate connected with the upper bearing seat and the lower bearing seat is 220-260°, the heat dissipation cavity is provided with a heat conduction plate, an oil cavity is formed between the heat conduction plate and the single support plate, the distance between the heat conduction plate and the main shaft is 2-4 times of the distance between the single support plate and the main shaft, and the heat conduction plate is connected with a lubricating oil circulating device.

2. The CNC machine tool headstock according to claim 1, characterized in that The lubricating oil circulating device comprises vertical grooves arranged on the heat conduction plate, lubricating oil can flow downward along the grooves, and the inner wall of the grooves is provided with a pattern for reducing the flow speed of the lubricating oil.

3. The CNC machine tool headstock of claim 1, wherein, The lubricating oil circulating device comprises a circulating pipe arranged outside the heat conduction plate, the upper end of the circulating pipe is communicated with the upper end of the oil cavity, the lower end of the circulating pipe is communicated with the lower end of the oil cavity, an upward conveying paddle is arranged in the circulating pipe, the conveying paddle is connected with a rotating driving device, the rotating driving device comprises a roller arranged on the rib plate, and the roller rotates in the process of moving the main shaft box.

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