Patent Grant
9827648
This application claims the foreign priority benefit under Title 35, United States Code, 119 (a)-(d) of Japanese Patent Application No. 2014-129287, filed on Jun. 24, 2014 in the Japan Patent Office, the disclosure of which is herein incorporated by reference in its entirety.
1. Technical Field
The present invention relates to a roller burnishing tool device, especially to a roller burnishing tool device equipped with a tool diameter following mechanism.
2. Description of Background Art
A roller burnishing tool device is a device which presses a roller or rollers, while rotating the roller or the rollers, onto a workpiece, for example, onto an inner surface of a cylindrical hole of the workpiece, to plastically deform and finish the surface to be a mirror surface. The finishing by using the roller burnishing tool device is affected by a variation of the diameter of the hole to be processed or a difference of several tens of microns (μm) in setting a tool diameter. Note that, in this specification, the variation is a variation among hole diameters of holes of workpieces to be processed, or a variation among hole diameters at positions in a hole of a workpiece to be processed in the axial direction of the hole. Hereinafter, these two types of hole diameters are sometimes called as an inner diameter (of an inner surface of a workpiece) or a hole diameter (of a workpiece) without distinction. Therefore, there is known a roller burnishing tool device equipped with an adjustment spring mechanism and a displacement mechanism, which device is capable of automatically coping with the variation of a hole diameter (following a tool diameter) (for example, the patent literature 1).
The roller burnishing tool device described in the patent literature 1 is controlled by the adjustment spring mechanism so that a change of a rotational load torque acting on the displacement mechanism is kept in a prescribed set value. The displacement mechanism is equipped with a roller unit disposed between a shank and a driver. The driver is moved in an axial direction relative to the shank by the change of the rotational load torque by utilizing a feed mechanism with a feed angle and a planetary motion of flexible rollers of the roller unit. Thus the roller burnishing tool device is capable of coping with the variation.
Patent literature 1: Japanese Patent No. 3245638, B (paragraphs 0044 to 0054, FIG. 1, FIG. 3)
However, in the roller burnishing tool device described in the patent literature 1, the displacement mechanism is disposed in the housing, so that the structure of the housing is complex and the outer size of the housing is large. Therefore, there has been a problem that an attachable processing machine is restricted.
Furthermore, the flexible rollers are consumable ones and an exchange of the flexible rollers is necessary. Nevertheless, there has been a problem that maintenance is hard to be performed because the structure of the housing is complex.
The present invention has been created in view of such a technical background. It is an object of the present invention to provide a roller burnishing tool device the structure of which is simplified to reduce the number of parts, to be downsized, and to improve workability in maintaining, and which is equipped with a tool diameter following mechanism.
To solve the above problems, the present invention provides a roller burnishing tool device including:
The present invention includes the tool diameter following mechanism. So by the tool diameter following mechanism, the rotational load torque and the axial force of the mandrel are balanced to be capable of automatically adjusting the pressing force in burnishing. Namely, the pressing force in burnishing can be kept to be a proper pressing force by flexibly coping with variations of the inner diameter of a workpiece to automatically adjust a tool diameter. As a result, a uniform finished surface can be made.
Furthermore, a plateau surface excellent in sliding characteristics can be easily made. Burnishing can make a mirror finish by crushing convex portions on a concavo-convex surface with rollers. However in a case of making a surface excellent in sliding characteristics, it is necessary to form ideal concavo and convex portions on a surface. Sizes of concavo and convex portions are largely changed when quantity to be burnished, that is, quantity of burnishing, changes by several microns (μm). The size of an inner diameter of a hole of a workpiece before being burnished by using rollers has a variation generally in micron order for machine parts (workpieces) mass-produced with a dimensional tolerance equal to or more than several microns. Therefore, processing of burnishing having a constant quantity of burnishing has not been able to be performed, so that forming concavo and convex portions having constant sizes has been hard. However, according to the present invention, quantity of burnishing can be kept to be constant by using the tool diameter following mechanism even in a case where a hole diameter varies. Therefore, constant concavo and convex portions, that is, a good plateau surface can be steadily made.
Thus a plateau surface can be made for a machine part which needs good sliding characteristics by using the roller burnishing tool device according to the present invention. So sliding performance of the machine part can be improved.
The present invention includes the lead groove formed spirally in the hollow cylindrical portion formed at the front portion of the shank, and the shank and the mandrel are connected with the pin member disposed so as to be capable of moving spirally along the lead groove to constitute the main portion of the tool diameter following mechanism. Thus the tool diameter following mechanism can be housed in the shank. So the outer dimensions of the housing can be formed to be small, so that the whole of the tool device can be miniaturized.
Thus the roller burnishing tool device according to the present invention is easily handled and the operability thereof is improved, and furthermore, the range of applying the tool device can be enlarged, so that the tool device can be applied to various processing machines.
Furthermore, it is not needed to house flexible rollers in the housing. Therefore, the constitution of the housing can be simplified to reduce the number of parts and consumables, and to improve assembly and disassembly performance.
Furthermore, it is preferable that the roller burnishing tool device further includes a biasing force adjusting tool to adjust biasing force of the biasing unit.
According to the above preferable constitution, the present invention includes the biasing force adjusting tool, so that the pressing force in burnishing can be properly adjusted. Therefore, a uniformly finished surface can be made.
The roller burnishing tool device according to the present invention simplifies the constitution thereof to reduce the number of parts and to be miniaturized. Furthermore, maintenance performance can be improved and a uniformly finished surface can be made.
A roller burnishing tool device according to an embodiment of the present invention will be described in detail appropriately with reference to the attached drawings.
As shown in
“Matching” in this specification means that each of the tapered rollers and the tapered portion of the mandrel come into contact with each other in the state of line-contacting. In some cases, each tapered roller 51 comes into contact with an inner surface of a cylindrical hole of a workpiece in the state of point-contacting, and in some cases, each tapered roller 51 comes into contact with an inner surface of a cylindrical hole of a workpiece in the state of line-contacting. For example, a case in which a tapered angle of each tapered roller 51 is as half in size as a tapered angle of the tapered portion 61b of the mandrel 6 is a case in which each tapered roller 51 comes into contact with the tapered portion 61b of the mandrel 6 in the state of line-contacting, and also comes into contact with an inner surface of a cylindrical hole of a workpiece in the state of line-contacting.
Note that, in the present embodiment, a use mode in which the shank 2 is attached to a processing machine (not shown) to be rotated will be explained as an example, but the present invention is not limited to this form. The processing can be performed even where the shank 2 is fixed to the processing machine (not shown) and a workpiece (not shown) is rotated.
For convenience of the following explanation, a shank 2 side (a right side in
The shank 2 is a hollow cylindrical member, and has a small diameter portion 21, a large diameter portion 22, a lead groove 24 (refer to
Note that, in the present embodiment, the small diameter portion 21 and the large diameter portion 22 are formed integrally, but the present invention is not limited to this. Each may be formed individually to be connected to each other. Furthermore, a front end portion (hollow cylindrical shape portion) of the large diameter portion 22, in which front end portion the lead groove 24 is formed, may be formed separately out of the large diameter portion 22.
The housing 3 has a housing body 31, a housing nut 32, a bearing 33, and a spring 34. The housing body 31 is connected to the shank 2. The housing nut 32 is screwed with the front end portion of the housing body 31 to be fixed. The bearing 33 supports the frame 5 so as to be capable of rotating, and is held between the rear end surface of the frame 5 and the front end surface of the housing body 31. The spring 34 intermediates between the housing nut 32 and the frame 5 so that the spring 34 urges the frame 5 to the bearing 33. And the spring 34 urges the frame 5 rearward via a thrust ring and a stop ring 34b engaged with the outer portion of the frame 5 at the rear end of the spring 34, while the spring 34 urges the front end portion of the housing nut 32 forward via a thrust ring 34a at the front end of the spring 34.
The housing body 31 is equipped with a plurality of recessed portions 31a (refer to
Thus, the housing nut 32 is fixed to the housing body 31 via the outer thread portion 31b. The inner thread portion 31c of the housing body 31 is screwed with the outer thread portion 23 of the shank 2, so that the housing body 31 can be moved along the axis of the shank 2 while rotating relative to the shank 2.
The housing nut 32 is a member to support the frame 5 so as to be capable of rotating. The housing nut 32 supports the frame 5 so as to be capable of rotating via the bearing 33 while urging the frame 5 rearward via the spring 34.
As shown in
The adjustment ring 4 can slide in the axial direction of the shank 2 in the state of engaging the slide key 42 with the axial direction groove 25 formed in the large diameter portion 22 of the shank 2.
Accordingly, the housing body 31 is a little rotated while sliding the adjustment ring 4 in the state of engaging the slide key 42 with the axial direction groove 25, so that the hook portion 41 can be engaged with one of the recessed portions 31a of the housing body 31. Thus, the adjustment ring 4 can set a relative position between the shank 2 and the housing 3 (the housing body 31 and the housing nut 32) in the front-rear direction, and connect the shank 2 and the housing 3 so as to be capable of integrally rotating.
As shown in
Each of the tapered rollers 51 has the tapered shape in which the front end side is enlarged, and the rear end side is shrunk. Each tapered roller 51 is pressed onto an inner surface of a workpiece (not shown) in the state of being supported on the outer surface of the mandrel 6. And in this state of being pressed, each tapered roller 51 is moved in the circumferential direction on the outer surface of the mandrel 6 (revolution round the mandrel 6), that is, on the outer surface of the front end portion of a first mandrel 61 while being rotated (rotation on its axis), so that burnishing the inner surface of the workpiece is performed. Note that, a diameter of a virtual circle in which the plurality of tapered rollers 51 are inscribed is called a tool diameter δ. Furthermore, the tool diameter δ is generally set to be larger by 10 to 40 μm than the inner diameter of a workpiece. When quantity to burnish is to be increased, the tool diameter δ is set to be larger.
The mandrel 6 has the first mandrel 61 like a rod disposed on the front side, and a second mandrel 62 like a cylindrical tube connected to the first mandrel 61. An outer thread portion 61a formed on the rear portion of the first mandrel 61 is screwed with an inner thread portion 62a formed inside the front portion of the second mandrel 62, and then a connecting nut 63 is fastened, so that the first mandrel 61 and the second mandrel 62 are connected together to enable to integrally rotate.
The tapered portion 61b is formed on the front end portion of the first mandrel 61, which portion 61b is matched to the tapered shape of each of the tapered rollers 51. A pin member insertion hole 62b is formed in the middle portion of the second mandrel 62 in the axial direction, and goes through in the direction orthogonal to the axial direction. Furthermore, a guide hole is formed inside the rear end portion of the second mandrel 62, which portion a spring 82 of a biasing unit is attached to.
<Tool Diameter Adjustment Mechanism>
A tool diameter adjustment mechanism is a mechanism to adjust the tool diameter δ by moving the frame 5 in the axial direction relative to the mandrel 6. When the tool diameter δ is adjusted, first the fixing screw 43 of the adjustment ring 4 is loosened, then the adjustment ring 4 is slid rearward to release the engagement between the hook portion 41 and one of the recessed portions 31a, so that the housing 3 can be moved in the axial direction relative to the shank 2 while being rotated.
The frame 5 supported by the housing 3 via the bearing 33, the spring 34 and so on is moved rearward relative to the mandrel 6 because the spring 34 and so on push the frame 5 rearward when the housing 3 is moved in the direction facing the shank 2, that is, rearward, so that the tool diameter δ can be enlarged along the tapered portion 61b of the first mandrel 61. Furthermore, the frame 5 supported by the housing 3 via the bearing 33, the spring 34 and so on is moved forward because the intermediated bearing 33 pushes the frame 5 forward when the housing 3 is moved in the direction going away from the shank 2, that is, forward, so that the tool diameter δ can be shrunk along the tapered portion 61b of the first mandrel 61.
<Tool Diameter Following Mechanism>
The tool diameter following mechanism 8 is a mechanism by which the pressing force at the time of processing a workpiece (not shown) is properly and automatically adjusted to balance the torque of the rotational load against the axial force of the mandrel 6, so that a smooth super-precision processed surface is made, even in the case where there is a variation of inner diameters of workpieces or there is a small taper rate of an inner surface of a workpiece.
The tool diameter following mechanism 8 has the lead groove 24 (refer to
The pin member 81 has a cylindrical hollow pin 81a, bolts 81b each of which has a hexagon hole, and bearings 81c. The cylindrical hollow pin 81a is inserted in the pin member insertion hole 62b formed in the second mandrel 62. The bolts 81b are attached to the respective end portions of the cylindrical hollow pin 81a. The bearings 81c are also attached to the respective end portions of the cylindrical hollow pin 81a.
Each bearing 81c is attached so that an outer ring thereof can be guided along the lead groove 24 (refer to
Next, operation of the tool diameter following mechanism 8 of the roller burnishing tool device 1 according to the embodiment of the present invention will be described with reference to
The roller burnishing tool device 1 according to the embodiment of the present invention is rotated after attaching the shank 2 to a processing machine not shown, so that the driving torque is transmitted to the mandrel 6 from the shank 2 via the tool diameter following mechanism 8. Burnishing is performed while rotating the mandrel 6 in the state of pressing the rollers 51 onto an inner surface of a workpiece (not shown). In the case where there is a variation of an inner diameter of an inner surface of a workpiece, an excessive load torque T1 acts on the mandrel 6 and an axial component force F1 is caused in processing.
The axial component force F1 forces the mandrel 6 to move rearward in the axial direction against the biasing force of the spring 82. That is, the pin member 81 is moved together with the mandrel 6 along the lead groove 24. Thus, the mandrel 6 is retreated together with the pin member 81 in the axial direction while being rotated relative to the shank 2 (refer to
As shown in
Because the roller burnishing tool device 1 according to the embodiment of the present invention is equipped with the tool diameter following mechanism 8, the pressing force in burnishing can be automatically adjusted by balancing the torque of the rotational load against the axial force of the mandrel 6. Therefore, a smooth super-precision processed surface can be made. Furthermore, the range of following up of the tool diameter δ can be properly set by appropriately setting the twist angle (lead quantity) of the lead groove 24 in accordance with specifications of the roller burnishing tool device.
In the roller burnishing tool device 1 according to the embodiment of the present invention, the tool diameter following mechanism 8 is constituted by connecting the shank 2 and the mandrel 6 with the pin member 81 disposed so as to be capable of moving along the spiral lead groove 24 formed in the front end portion of the shank 2. Thus the tool diameter following mechanism 8 can be housed inside the shank 2. Therefore, the outer diameter of the housing 3 can be made smaller, so that the roller burnishing tool device 1 can be downsized.
Thus the roller burnishing tool device 1 according to the embodiment of the present invention can be easily handled and improve the operability. And a range where the roller burnishing tool device 1 is adapted, is enlarged and the roller burnishing tool device 1 can be properly used for various processing machines. Furthermore, there is no necessity to dispose flexible rollers in the housing 3, so that the housing 3 can be simplified to reduce the numbers of parts and consumables, and to improve assembly and disassembly performance.
<Assembly and Disassembly Performance>
How to assemble and disassemble the roller burnishing tool device 1 according to the embodiment of the present invention will be explained mainly with reference to
First, the housing nut 32 is loosened to be removed together with the spring 34 from the housing body 31. Then the frame 5 can be removed together with the tapered rollers 51. At this time, the bearing 33 is also removed.
After the connecting nut 63 is loosened, the first mandrel 61 can be removed from the second mandrel 62 by rotating the first mandrel 61. After loosening the fixing screw 43, the adjustment ring 4 can be removed by moving the adjustment ring 4 in the axial direction along the axial direction groove 25. Thus after the adjustment ring 4 is removed, the housing body 31 can be rotated. So the housing body 31 is removed by rotating the housing body 31 relative to the shank 2.
Regarding how to disassemble the tool diameter following mechanism 8, first, the pin member 81 is disassembled to be removed. Regarding how to disassemble the pin member 81, after the bearing 81c is removed by loosening the bolt 81b having the hexagon hole, the cylindrical hollow pin 81a is removed out of the pin member insertion hole 62b of the second mandrel 62.
Then since the second mandrel 62 can be pulled out of the shank 2, the spring 82 and the bearing 83 are also removed together.
In such a manner, the roller burnishing tool device 1 according to the embodiment of the present invention can be easily disassembled. Note that, since the way how to assemble the device 1 is the reverse of disassembling the device, an explanation for assembling is omitted. The roller burnishing tool device 1 according to the embodiment of the present invention can be easily handled and easily disassembled, so that maintenance performance is good.
In the above, the embodiment of the present invention has been described, but the present invention is not limited to the embodiment and can be carried out by appropriately modifying the embodiment.
For example, the embodiment is a single row roller type embodiment that the rollers 51 are disposed around the front end portion of the mandrel 6. But the present invention is not limited to this, and may be configured to be a double row roller type embodiment that another set of rollers (not shown) having a tool diameter different from the rollers 51 is disposed behind the rollers 51.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2014-129287 | Jun 2014 | JP | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 2835958 | Mock | May 1958 | A |
| 3069750 | Koppelmann | Dec 1962 | A |
| 3099070 | Morrison | Jul 1963 | A |
| 3130477 | Gill | Apr 1964 | A |
| 3555643 | Koppelmann | Jan 1971 | A |
| 3751781 | Koppelmann | Aug 1973 | A |
| 3840957 | Koppelmann | Oct 1974 | A |
| 4542565 | Berstein | Sep 1985 | A |
| 20020046451 | Okeda | Apr 2002 | A1 |
| Number | Date | Country |
|---|---|---|
| 0503109 | Sep 1992 | EP |
| 3245638 | Jan 2002 | JP |
| Entry |
|---|
| Extended European Search Report dated Dec. 9, 2015 corresponding to European Patent Application No. 5173626.1. |
| Number | Date | Country | |
|---|---|---|---|
| 20150367479 A1 | Dec 2015 | US |
