A special tool for flat center A special tool for flat center

Abstract

The application provides a special tool for a flat top center, which can guarantee the positioning accuracy and stability of the top center and ensure the machining accuracy of the blade. The tool comprises a top center shaft, which is installed in a top center seat, the top center seat is installed in a mounting cavity of a machine tool slide cylinder, and the top center seat and the top center shaft are connected by screws, the shape of the mounting cavity of the machine tool slide cylinder is matched with the shape of the top center seat; the top center shaft comprises a shaft body and a top head, the top surface of the top head is a flat surface, and the top surface of the top head is fixedly installed with a tooth surface pressing block; the shaft body comprises three cylindrical sections with decreasing radii from top to bottom, namely a first cylindrical section, a second cylindrical section and a third cylindrical section, the outer part of the joint between the third cylindrical section and the top center seat is successively sleeved with a thrust ball bearing and a needle bearing from top to bottom; the outer part of the joint between the second cylindrical section and the top center seat is successively sleeved with a pair of angular contact ball bearings from top to bottom, the upper end surface of the outer ring of the upper angular contact ball bearing is press-fitted with an end cover, the end cover is sleeved on the outer part of the first cylindrical section, and a first sealing ring is arranged at the joint between the end cover and the first cylindrical section.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of machine tool centers, in particular to a special tool for flat head centers. BACKGROUND

[0002] The center is a machine tool part in mechanical processing, which can fix the workpiece on the machine tool workbench, so that the fixed position is accurate, which is beneficial to improve the machining precision. The center head of the existing machine tool center is usually conical, and the center head is inserted into the center hole of the blade to realize the positioning of the blade. However, in the process of blade processing, the center hole of the blade often deforms due to stress, at which time the center head and the center hole do not match, the center head cannot be inserted into the center hole, or a gap appears between the center head and the center hole, causing the blade to loosen. This leads to a decrease in the positioning accuracy and stability of the center. SUMMARY

[0003] In view of the problem that the centering accuracy and stability of the center decrease due to the mismatch between the center head and the center hole caused by the deformation of the center hole of the blade in the existing blade processing, the present application provides a special tool for flat head centers, which can ensure the positioning accuracy and stability of the center and ensure the machining precision of the blade.

[0004] A special tool for flat head centers, comprising a center shaft, the center shaft is installed in a center seat, the center seat is installed in the installation cavity of the machine tool slide, and the two are connected by screws, the shape of the installation cavity of the machine tool slide matches the outer shape of the center seat; characterized in that: the center shaft comprises a shaft body and a head, the top surface of the head is a flat surface, and the top surface of the head is fixedly installed with a tooth surface pressing block; the shaft body comprises three cylindrical sections with decreasing radii from top to bottom, namely a first cylindrical section, a second cylindrical section and a third cylindrical section, the outer part of the joint between the third cylindrical section and the center seat is successively sleeved with a thrust ball bearing and a needle bearing from top to bottom; the outer part of the joint between the second cylindrical section and the center seat is successively sleeved with a pair of angular contact ball bearings from top to bottom, the upper end surface of the outer ring of the upper angular contact ball bearing is pressed with an end cover, the end cover is sleeved on the outer part of the first cylindrical section, a first sealing ring is arranged at the joint between the end cover and the first cylindrical section, a second sealing ring is arranged at the joint between the end cover and the center seat, and the needle bearing, the thrust ball bearing and the angular contact ball bearing are used to prevent the center from appearing radial displacement.

[0005] Further characterized in that:

[0006] A plug is arranged on the bottom end cover of the shaft body;

[0007] The plug and the end cover are used to prevent the pressed needle bearing, thrust ball bearing and angular contact ball bearing from being axially displaced when stressed.

[0008] By adopting the above structure of the present application, the tooth surface pressing block is pressed against the flat surface at the orifice of the center hole of the blade, and the extremely high friction and engagement force of the tooth surface pressing block can realize the stable positioning of the blade, and the positioning is not dependent on the center hole, and even if the center hole is deformed, it can still be used, thereby improving the positioning precision and stability of the blade and ensuring the machining precision of the blade. The arrangement of the needle bearing, the thrust ball bearing and the angular contact ball bearing can prevent the radial displacement of the center, thereby ensuring the positioning precision and stability. The arrangement of the plug and the end cover can compress the needle bearing, the thrust ball bearing and the angular contact ball bearing, prevent the axial displacement of the bearing under force, and further ensure the positioning precision and stability and the machining precision of the blade. The first sealing ring and the second sealing ring ensure the installation sealing between the end cover, the center shaft and the center seat, prevent the center itself from loosening, ensure the positioning precision and stability from the perspective of ensuring the installation stability of the device, and ensure the machining precision of the blade. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 It is a schematic view of the present application in section;

[0010] Figure 2 It is a schematic view of the present application in axis measurement;

[0011] Figure 3 It is a schematic view of the structure when the present application installs the four-week Morse taper. DETAILED DESCRIPTION

[0012] See Figure 1 , Figure 2 A flat center special tool, which comprises a center shaft 1, the center shaft 1 is installed in a center seat 4, the center seat 4 is installed in the installation cavity of a machine tool slide cylinder 13, and is connected by screws, the shape of the installation cavity of the machine tool slide cylinder 13 matches the shape of the center seat 4; the center shaft 1 comprises a shaft body 12 and a tip 11, the top surface of the tip 11 is a flat surface, and the top surface of the tip 11 is fixedly installed with a tooth surface pressing block 14; the shaft body 12 comprises three cylindrical sections with radii decreasing from top to bottom, i.e. a first cylindrical section 121, a second cylindrical section 122 and a third cylindrical section 123, the outer part of the joint between the third cylindrical section 123 and the center seat 4 is successively sleeved with a thrust ball bearing 6 and a needle bearing 7 from top to bottom; the outer part of the joint between the second cylindrical section 122 and the center seat 4 is sleeved with a pair of angular contact ball bearings 5 from top to bottom, the upper end surface of the outer ring of the upper angular contact ball bearing 5 is pressed with an end cover 2, the end cover 2 is sleeved on the outer part of the first cylindrical section 121, a first sealing ring 8 is arranged at the joint between the end cover 2 and the first cylindrical section 121, and a second sealing ring 9 is arranged at the joint between the end cover 2 and the center seat 4; the needle bearing 7, the thrust ball bearing 6 and the angular contact ball bearing 5 are used to prevent the radial displacement of the center.

[0013] The bottom end cover of the shaft body 12 is provided with a plug 10.

[0014] The plug 10 and the end cover 2 are used to prevent axial displacement of the compression needle bearing 7, the thrust ball bearing 6 and the angular contact ball bearing 5 when they are subjected to force.

[0015] See Figure 3 When the center is used for a four-axis machine tool, the bottom of the center seat 4 is mounted with a four-axis Morse taper 15, which is mounted on the four-axis machine tool.

[0016] When installing, the immersion liquid nitrogen cooling method is used. First, the center seat 4 is installed into the installation cavity of the machine tool slide 13, then the two needle bearings 7 are installed into the bottom of the center seat 4, then the thrust ball bearing 6 and the angular contact ball bearing 5 are installed, and then the first sealing ring 8 is sleeved on the center shaft. After the needle bearing 7, the thrust ball bearing 6 and the angular contact ball bearing 5 are warmed up, the cooled center shaft 1 is installed into the center seat 4, the bottom surface of the first column segment 121 is tightly attached to the top surface of the angular contact bearing, and then the second sealing ring 9 is sleeved on the end cover. The end cover 2 is squeezed into the center seat 4, and then the inner hexagonal bolt 3 is installed to tightly lock the end cover 2 with the center seat 4, and then the plug 10 is installed and gently screwed on. If the center is used for a four-axis machine tool, the assembled bottom of the center is connected with the four-axis Morse taper 15, and the four-axis machine tool has a self-locking function, which can automatically lock the four-axis Morse taper 15. This is the prior art and will not be described in detail here. During installation, lubricating grease needs to be applied to the center seat 4 and the needle bearing 7, the thrust ball bearing 6, the angular contact ball bearing 5, the first sealing ring 8 and the second sealing ring 9.

[0017] When in use, the tooth surface pressing block 14 of the center head 11 is pressed against the flat surface at the orifice of the center hole of the blade, and the extremely high friction and engagement force of the tooth surface pressing block 14 can realize stable positioning of the blade. It can also be used for positioning the machining of other workpieces with flat end faces.

Claims

1. A tooling for a flat center, comprising a center shaft, which is mounted in a center seat, the center seat is mounted in a mounting cavity of a machine tool slide, the mounting cavity of the machine tool slide is matched with the outer shape of the center seat; characterized in that: The top center shaft comprises a shaft body and a top head, the top surface of the top head is a plane, and a tooth surface pressing block is fixedly installed on the top surface of the top head; the shaft body comprises three cylindrical sections with radii decreasing from top to bottom, namely a first cylindrical section, a second cylindrical section and a third cylindrical section, a thrust ball bearing and a needle bearing are sleeved on the outside of the joint between the third cylindrical section and the top center seat from top to bottom, a pair of angular contact ball bearings are sleeved on the outside of the joint between the second cylindrical section and the top center seat from top to bottom, the upper end surface of the outer ring of the upper angular contact ball bearing is pressed by an end cover, the end cover is sleeved on the outside of the first cylindrical section, a first sealing ring is arranged at the joint between the end cover and the first cylindrical section, a second sealing ring is arranged at the joint between the end cover and the top center seat, and the needle bearing, the thrust ball bearing and the angular contact ball bearing are used for preventing the top center from being radially displaced.

2. A tooling set for a flat centre according to claim 1, characterised in that: A plug is installed on the bottom end cover of the shaft body.

3. A tooling set for a flat centre according to claim 2, characterised in that: The plug and the end cover are used for preventing the needle bearing, the thrust ball bearing and the angular contact ball bearing from being axially displaced when bearing force.

Images