A screw drive structure with a thermal expansion compensation mechanism

Abstract

The present invention discloses a thermal expansion compensation mechanism, an end expansion structure and a screw drive structure to which the thermal expansion compensation mechanism is applied. The thermal expansion compensation mechanism includes a main spindle box, a thermal expansion component, a compensation rod and a temperature controller; a temperature monitoring device is installed on the thermal expansion component, a heating and temperature monitoring device is installed on the compensation rod, the movable end of the compensation rod is connected to the fixed end of the thermal expansion component, the fixed end of the thermal expansion component is connected to the main spindle box, the compensation rod and the thermal expansion component have the same coefficient of thermal expansion, and the temperature controller is connected to the temperature monitoring device on the thermal expansion component and the heating and temperature monitoring device on the compensation rod. The present invention greatly improves the precision stability of the equipment when it is just started or operates irregularly, enables the equipment to be put into use without idling for preheating, and solves the problem of unstable precision caused by irregular thermal expansion, thereby improving the use efficiency of the equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal expansion compensation, and particularly to a screw drive structure with a thermal expansion compensation mechanism. Background Art

[0002] During the working process of precision automation equipment and machine tools, due to the characteristics of some structures or mechanisms, heat will be generated, and this heat will cause the overall or partial temperature of the main components to be different from the ambient temperature. Due to the temperature difference, the main components will generate corresponding thermal expansion. Although after the equipment runs for a period of time, the expansion amount will tend to be stable and will not have too much impact on the use of the equipment, before formal work, the equipment needs to run for a period of time to make the expansion amount tend to be stable before it can operate. This situation will affect the normal use efficiency of the equipment and will also increase the wear of the equipment.

[0003] In precision equipment, the clamping mechanism is a very important structure, which directly affects the precision of the manufactured products. However, after many automatic clamping mechanisms work for a period of time, due to the factors of their working principles, heat will be generated or heat will be indirectly received, resulting in expansion. For example, an electromagnetic chuck will generate a certain temperature due to the electromagnetic field factor; in a hydraulic clamping mechanism, heat will be generated by friction during the operation of the oil pump, causing the hydraulic oil to heat up and then conduct to the clamping mechanism.

[0004] For example, when the main material of an electromagnetic chuck is marble and its overall thickness is 150 mm, when its own temperature is 30 °C higher than the ambient temperature, its expansion amount can reach 0.0207 mm. If the processing error and cumulative error during the processing process are added, it is very likely that the quality requirements cannot be met, and even the error requirements of some precision parts are much smaller than this value.

[0005] In precision equipment, the screw drive mechanism, such as ball screws and trapezoidal screws, is the mechanism that is most likely to have such problems. During the working process of screw drive, the frictional heat will cause the temperature of the screw to change, and this temperature change will vary according to factors such as the change of the main working position of the screw and the change of the working intensity. For example, in a screw drive mechanism that is frequently used at high speed and reciprocates, the frequent reciprocating distance is 500 mm. When the temperature of the screw is 40 °C higher than the ambient temperature, its expansion amount can reach 0.25 mm. Summary of the Invention

[0006] In order to solve the above problems, the present invention provides a screw drive structure with a thermal expansion compensation mechanism.

[0007] To solve the above technical problems, the technical solution of the present invention is as follows: a thermal expansion compensation mechanism, including a spindle box, a thermal expansion component, a compensation rod, and a temperature controller; a temperature monitoring device is installed on the thermal expansion component, a heating and temperature monitoring device is installed on the compensation rod, the movable end of the compensation rod is connected to the fixed end of the thermal expansion component, the fixed end of the thermal expansion component is connected to the spindle box, the compensation rod has the same coefficient of thermal expansion as the thermal expansion component, and the temperature controller is connected to the temperature monitoring device on the thermal expansion component and the heating and temperature monitoring device on the compensation rod.

[0008] An end expansion structure, having a thermal expansion compensation mechanism, the thermal expansion component is a clamping mechanism, a temperature monitoring device is installed on the clamping mechanism, the fixed end of the clamping mechanism is connected to the spindle box, the spindle box is connected to a first slider, the first slider is slidably connected to a slide rail, the slide rail is installed on a first frame, the first frame is connected to the fixed end of the compensation rod, the movable end of the compensation rod is connected to the fixed end of the clamping mechanism, and a heating and temperature monitoring device is installed on the compensation rod.

[0009] Further, it further includes a first slide plate, the first slide plate is of an L-shaped structure, the long side of the first slide plate is horizontally fixed between the spindle box and the first slider, the short side of the first slide plate is vertically downward, and its inner side is connected to the movable end of the compensation rod.

[0010] A screw drive structure, having a thermal expansion compensation mechanism, the thermal expansion component is a screw rod, a temperature monitoring device is installed on the screw rod, the fixed end of the screw rod is connected to the spindle box through a nut, the spindle box is connected to a first slider, the first slider is slidably connected to a slide rail, the slide rail is installed on a second frame, the second frame is connected to the fixed end of the compensation rod, the movable end of the compensation rod is connected to the movable end of the screw rod through a motor mounting bracket, a traveling motor is installed on the motor mounting bracket and is connected to the movable end of the screw rod, the motor mounting bracket is slidably connected to the slide rail through a second slider, and a heating and temperature monitoring device is installed on the compensation rod.

[0011] Further, it further includes a second slide plate, the second slide plate is fixed between the spindle box and the first slider, and the nut is fixed on the second slide plate.

[0012] Further, the second frame is connected to the fixed end of the compensation rod through a fixing block.

[0013] Further, a plurality of temperature monitoring devices are installed on the screw rod at intervals, and corresponding numbers of heating and temperature monitoring devices are installed on the compensation rod corresponding to the temperature monitoring devices on the screw rod.

[0014] The present invention greatly improves the precision stability of the equipment when it is just started or operates irregularly, enables the equipment to be put into use without idling for preheating, and solves the problem of unstable precision caused by irregular thermal expansion, improving the use efficiency of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is the front view of the end expansion structure;

[0016] Figure 2 It is the side view of the end expansion structure;

[0017] Figure 3 It is Figure 2 the A-A sectional view of;

[0018] Figure 4 It is the front view of the screw drive structure;

[0019] Figure 5 It is the side view of the screw drive structure;

[0020] Figure 6 It is Figure 5 the B-B sectional view of;

[0021] Figure 7 It is the thermal expansion compensation logic diagram.

[0022] Among them: 1. Clamping mechanism; 2. Headstock; 3. First slide plate; 4. First slider; 5. Slide rail; 6. First frame; 7. Compensation rod; 8. Heating and temperature monitoring device; 9. Second slide plate; 10. Fixed block; 11. Second frame; 12. Nut; 13. Traveling motor; 14. Screw; 15. Second slider; 16. Motor mounting bracket. Specific implementation mode

[0023] The following combines the attached Figures 1-7 to further illustrate the specific implementation mode of the present invention.

[0024] The thermal expansion compensation mechanism includes a headstock 2, thermal expansion components, a compensation rod 7, and a temperature controller; a temperature monitoring device is installed on the thermal expansion components, a heating and temperature monitoring device 8 is installed on the compensation rod 7, the movable end of the compensation rod 7 is connected to the fixed end of the thermal expansion components, the fixed end of the thermal expansion components is connected to the headstock 2, the compensation rod 7 has the same coefficient of thermal expansion as the thermal expansion components, and the temperature controller is connected to the temperature monitoring device on the thermal expansion components and the heating and temperature monitoring device 8 on the compensation rod 7.

[0025] Data is input into the temperature controller in real time through the temperature monitoring device on the thermal expansion components. The temperature controller heats the compensation rod 7 based on the monitored temperature data, and then corrects the data through the temperature monitoring device on the compensation rod 7. Since the material of the compensation rod 7 is the same as that of the thermal expansion components, their linear coefficients of thermal expansion are also the same. We make the temperatures of the two the same through the temperature monitoring device and the heating device, so that the expansion values of the two can also be the same, thereby achieving the purpose of compensation.

[0026] The end expansion structure has a thermal expansion compensation mechanism. The thermal expansion component is the clamping mechanism 1. A temperature monitoring device is installed on the clamping mechanism 1. The fixed end of the clamping mechanism 1 is connected to the spindle box 2. The first slide plate 3 is of an L-shaped structure. The long side of the first slide plate 3 is horizontally fixed between the spindle box 2 and the first slider 4. The short side of the first slide plate 3 is vertically downward, and its inner side is connected to the movable end of the compensation rod 7. The first slider 4 is slidably connected to the slide rail 5. The slide rail 5 is installed on the first frame 6. The first frame 6 is connected to the fixed end of the compensation rod 7. The movable end of the compensation rod 7 is connected to the fixed end of the clamping mechanism 1. A heating and temperature monitoring device 8 is installed on the compensation rod 7.

[0027] When thermal expansion occurs in the clamping mechanism 1, the structure in Figures 1-3 can be adopted. A slide rail 5 and a first slider 4 are added between the spindle box 2 and the first frame 6 to enable adjustment. A compensation rod 7 with a heating and temperature monitoring device 8 is added. A temperature monitoring device is also added to the clamping mechanism 1. Through the Figure 7 compensation logic in

[0028] the expansion can be compensated. In actual use, when the size of the clamping mechanism 1 is 150 mm and the temperature difference is 30 °C, its thermal expansion is 0.0207 mm. Through this device, 0.0186 - 0.227 mm can be compensated back, and basically 85% of the deviation can be compensated back.

[0029] The screw drive structure has a thermal expansion compensation mechanism. The thermal expansion component is the screw 14. The second slide plate 9 is fixed between the spindle box 2 and the first slider 4. The nut 12 is fixed on the second slide plate 9. The nut 12 is connected to the fixed end of the screw 14. The first slider 4 is slidably connected to the slide rail 5. The slide rail 5 is installed on the second frame 11. The second frame 11 is connected to the fixed end of the compensation rod 7 through the fixed block 10. The movable end of the compensation rod 7 is connected to the movable end of the screw 14 through the motor mounting bracket 16. A traveling motor 13 is installed on the motor mounting bracket 16. The traveling motor 13 is connected to the movable end of the screw 14. The motor mounting bracket 16 is slidably connected to the slide rail 5 through the second slider 15. A number of temperature monitoring devices are installed on the screw 14 at intervals. Corresponding to the temperature monitoring devices on the screw 14, a corresponding number of heating and temperature monitoring devices 8 are installed on the compensation rod 7.

[0030] When thermal expansion occurs in the screw 14 in the screw drive mechanism, the structure in Figures 4-6 can be used for compensation. In the original structure, the motor mounting bracket 16 is fixed to the second frame 11 and cannot move. During the improvement process, the motor mounting bracket 16 needs to be made movable. The specific operation method is to add a first slider 4 and share the slide rail 5 with the second slide plate 9; a compensation rod 7 with a heating and temperature monitoring device 8 is added to the motor mounting bracket 16, and the other end of the compensation rod 7 is fixed to the second frame 11, so that reverse adjustment can be achieved.

[0031] In the specific use process of the screw drive mechanism, since the use positions and frequencies of the screw 14 and the nut 12 are different at different times, this also leads to great changes in factors such as the heat generation position and duration of the screw 14. Therefore, the structure adopted in this example is multi-point temperature acquisition. The compensation rod 7 also needs to correspond to the number of temperature monitoring positions of the screw 14, and the heating and temperature monitoring device 8 is added, which makes the temperatures of the screw 14 and the compensation rod 7 at the same position as consistent as possible. Theoretically, the more temperature acquisition positions of the screw 14, the higher the compensation accuracy will be.

[0032] In actual use, when the reciprocating distance of the screw 14 is 500 mm and the temperature of the screw 14 is 40 °C higher than the ambient temperature, its expansion amount can reach 0.25 mm, and the distance that can achieve segmented compensation can also be between 0.212 - 0.275 mm. And due to the factors of the transmission structure, the thermal expansion position and the temperature difference from the environment are determined according to the equipment operation speed and the equipment operation trajectory. This problem cannot be solved by idling the heat engine, and this solution can solve this problem well.

[0033] The above is only the preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A screw drive structure with a thermal expansion compensation mechanism, characterized in that, It includes a headstock (2), a thermal expansion component, a compensation rod (7) and a temperature controller; a temperature monitoring device is installed on the thermal expansion component, a heating and temperature monitoring device (8) is installed on the compensation rod (7), the compensation rod (7) has the same coefficient of thermal expansion as the thermal expansion component, and the temperature controller is connected to the temperature monitoring device on the thermal expansion component and the heating and temperature monitoring device (8) on the compensation rod (7); among them, the thermal expansion component is a screw rod (14), the fixed end of the screw rod (14) is connected to the headstock (2) through a nut (12), the headstock (2) is connected to a first slider (4), the first slider (4) is slidably connected to a slide rail (5), the slide rail (5) is fixedly installed on a second frame (11), the second frame (11) is connected to the fixed end of the compensation rod (7) through a fixing block (10), the movable end of the compensation rod (7) is connected to the movable end of the screw rod (14) through a motor mounting bracket (16), a traveling motor (13) is installed on the motor mounting bracket (16), the traveling motor (13) is connected to the movable end of the screw rod (14), and the motor mounting bracket (16) is slidably connected to the slide rail (5) through a second slider (15); a second slide plate (9) is fixed between the headstock (2) and the first slider (4), and the nut (12) is fixed on the second slide plate (9).

2. The screw drive structure according to claim 1, characterized in that A number of temperature monitoring devices are installed on the screw rod (14) at intervals, and a corresponding number of heating and temperature monitoring devices (8) are installed on the compensation rod (7) corresponding to the temperature monitoring devices on the screw rod (14).

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