JPH0451961Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention is a processing mechanism for a super finishing machine that smooths and finishes workpiece surfaces such as the outer surface of a cylinder, the inner surface of a hole, and a flat surface finished using a precision boring machine, grinding machine, etc. It is related to.

BACKGROUND TECHNOLOGY A super finishing machine is a machine that grinds a workpiece by pressing a grindstone with fine grain size and relatively low bonding degree against the surface of a workpiece under low pressure.

FIGS. 4 and 5 show a conventional example of a super-finishing machine, and this super-finishing machine includes a head 3 having a grinding wheel 2 driven by a motor 1, and the grinding wheel 2 touching the workpiece 4. A pressing means 5 for moving in the pressing direction, an elastic member 6 interposed between the pressing means 5 and the head 3, and a pressing drive for pressing and displacing the head 3 in a direction opposite to the pressing direction. and a control device 8 for controlling the operation of the pressing drive means 7 in accordance with the drive current of the motor 1.

In such a configuration, when the head 3 is moved by the pressing means 5 and the grindstone 2 is pressed against the workpiece 4, the amount of deformation of the workpiece surface is absorbed and followed within the expandable and contractable range of the elastic member 6. . As for the stepped work surface that cannot be absorbed by the elastic member 6, the control device 8 which inputs the current value of the grindstone drive motor 1 operates the pressing drive means 7 so that the current value becomes a predetermined value. Displace head 3. That is, while controlling the drive current by feeding back, the head 3 is moved and displaced from the direction opposite to the pressing direction by the pressing drive means 7, and the cutting depth of the grindstone 2 into the workpiece 4 is maintained at an appropriate value to perform grinding. Therefore, the grinding wheel 2 can freely follow even a step-like work surface that cannot be absorbed by the elastic member 6, so that the surface accuracy required for the product can be obtained.

Problems to be Solved by the Invention However, although the above-mentioned conventional device is equipped with the elastic member 6, the head 3 simply slides relative to the pressing means 5. When the workpiece is dented during forging or has an irregular shape with an uneven surface, such as a product with a different diameter, the grinding wheel bounces and receives impact when following the workpiece 4 in the longitudinal direction. It becomes easier.

Furthermore, since the grindstone 2 simply rotates, the processing area cannot be made very large as it is limited by the size of the grindstone 2, which may cause problems in ensuring surface roughness.

Means for Solving the Problems In order to solve the above problems, the present invention provides a head having a grindstone driven by a motor, a pressing means for moving the head in a direction in which the grindstone is pressed against a workpiece, and a pressing means for moving the head in a direction in which the grindstone is pressed against a workpiece. an elastic member interposed between the means and the head, a pressing drive means for pressing and displacing the head in a direction opposite to the pressing direction, and an operation of the pressing driving means according to a drive current of the motor. In the processing mechanism of the super finishing machine, the head is fixed to one end of a lever pivotally connected to the pressing means, and the elastic member moves the head together with the lever to the workpiece. A cylindrical cam follower is loosely fitted onto the shaft of the grindstone and is integrated with the shaft, and a cam driven by another motor is installed in the head. , the cam is engaged with the cam follower.

Function: The head is pivotally connected to the pressing means via a lever,
Since the elastic member is provided at a position to rotate the head toward the workpiece, the grindstone can be rotated about the pivot point of the lever. Therefore, the grindstone follows the workpiece smoothly.

Further, the grindstone oscillates in the axial direction as a result of following the movement of a cam or a cylindrical cam follower loosely fitted to its shaft.

Therefore, the machining area becomes larger and surface machining accuracy improves.

Embodiments Hereinafter, embodiments of the present invention will be described based on FIGS. 1 to 3.

In FIGS. 1 and 2, reference numeral 9 indicates a superfinishing machine body.

The main body 9 has a bracket 10 on its upper part,
A head 12 of a grindstone 11 is provided below the bracket 10.

The head 12 is held by a pressing means that moves the grindstone 11 in a direction to press it against the workpiece 13.

The pressing means is in this case a cylinder device 14,
The cylinder 15 of the cylinder device 14 is fixed to the bracket 10, and the rod 16 extends downward. A lever 17 for supporting the head 12 is pivotally attached to the lower end of the rod 16.

The pressing means also includes a guide bar 18 extending parallel to the rod 16 and a slider 19 sliding along the guide bar 18. The guide rod 18 is passed between the lower part of the super-finishing machine body 9 and the bracket 10, and is connected to the slider 19.
The rod 16 is connected to the rod 16.

Therefore, the slider 19 moves up and down along the guide rod 18 by the operation of the cylinder device 14.

The lever 17 has a pivot 20 relative to the slider 19.
The head 12 of the grindstone 11 is provided at one end with a pivot 20 in between, and the motor 21 for rotating the grindstone 11 is provided at the other end. In addition, a spring 2 serving as an elastic member is provided at the other end.
2 to the slider 19.

As a result, the head 12 rotates toward the workpiece 13 using the pivot shaft 20 as a fulcrum, and the grindstone 11 driven by the motor 21 comes into contact with the workpiece 13 and grinds it.

The head 12 of the grindstone 11 has a structure as shown in FIG.

As shown in this figure, a cylindrical cam follower 24 is loosely fitted onto the shaft 23 of the grindstone 11 and is integrated therewith. Reference numeral 25 is a bearing provided between the shaft 23 and the cam follower 24 for loose fitting.

The rear end of the shaft 23 protrudes from the cam follower 24,
A pulley 42 is fixed to its protruding end.

In this way, the pulley 42 is fixed to the end of the shaft 23,
Further, since the pulley 42 pushes the bearing 25 toward the grindstone 11 via the tube 26 around the shaft, the shaft 23 rotates relative to the cam follower 24 without coming off the cam follower 24.

Note that the rotation of the shaft 23 is caused by the motor 21 and the pulley 4.
2 by power transmission via a belt (not shown), the belt extending along the lever.

The main body 27 of the head 12 is loosely fitted onto the outer periphery of the cam follower 24.

The main body 27 of the head is fixed to the lever 17, a hydraulic motor 28 is fixed to the upper part thereof, and a rotation stopper 29 is provided to the lower part.

An eccentric pin 30 serving as a cam is fixed to the shaft 29 of the hydraulic motor 28, and the eccentric pin 30 is inserted into a hole bored in the cam follower 24. Note that the reference numeral 31 is a bush inserted into the hole. The amount of eccentricity in this case is approximately 5 mm.

When the hydraulic motor 28 is thereby driven, the cam follower 24 oscillates along the center line of the shaft 23, and the shaft 23 independently rotates while oscillating together with the cam follower 24 to turn the grindstone 11. Whetstone 1
1 oscillates in the range of 2d≈10mm as shown in Figure 3.

The rotation stopper 41 is used to prevent the cam follower 24 from rotating when the eccentric pin 30 is inserted into the hole, and is provided as necessary.

A protruding rod 3 is located approximately in the center of the slider 19.
2 is provided. On the other hand, a stopper 33 constituting a pressing drive means is disposed in a position corresponding to the protruding rod 32 of the superfinishing machine body 9 so as to be movable up and down. A motor 34 is connected to the stopper 33, and the rotation of the motor 34 causes the stopper 33 to move up and down continuously with respect to the main body 9. A brake dog 35 is connected to the stopper 33 via a rod 40, and a limit switch 36 that comes into contact with this dog 35 is disposed at the bottom of the slider 19.

Reference numeral 37 is a control device for controlling the operation of the stopper motor 34. The control device 37 has a built-in meter relay (not shown) that detects the drive current of the grindstone drive motor 21. An upper limit current value and a lower limit current value are set in the meter relay according to the amount of deflection of the spring 22, and when the drive current reaches the set value during machining, the lowering operation of the head 12 etc. by the cylinder device 14 is immediately stopped. It's becoming like that.

In addition, the reference numeral 38 in FIGS. 1 and 2 is a traverse cylinder device for moving the rod-shaped work 13 in its axial direction. Further, reference numeral 39 indicates a balance weight that balances the weight of the head 12 and the like.

The super finishing machine having such a configuration performs grinding and finishing processing of the workpiece 13 in the following manner.

That is, when the head 12 and the like are lowered by the operation of the cylinder device 14, and the grindstone 11 is lowered to a position close to contacting the workpiece 13, the limit switch 36 of the slider 19 comes into contact with the brake dog 35 and is activated, causing the head 12 to lower. Operation is switched to low speed. After that, the workpiece 13 is moved in its axial direction by the traverse cylinder device 38,
Grinding is started when the grindstone 11 driven by the motor 21 comes into contact with the surface of the workpiece 13.

During the process of processing using the grindstone 11, the drive current of the grindstone drive motor 21 is constantly detected by a meter relay. When the drive current of the motor 21 reaches the set value, the head 12 is activated by the cylinder device 14.
etc., will be stopped immediately. In this state, the spring 22 is stretched, and the grinding wheel 11 of the head 12
is elastically pressed against the processing surface of the workpiece 13. The grindstone 11 follows the irregularities on the surface of the workpiece 13 within the range of the deflection of the spring 22 and the rotation of the lever 17, and the grinding process is performed.

Here, if the grindstone 11 cannot follow the uneven surface of the workpiece 13 within the range of the deflection of the spring 22, etc., the amount of cut into the workpiece 13 by the grindstone 11 deviates from the appropriate value. This is automatically corrected by the following operation.

That is, when the depth of cut of the grindstone 11 deviates from the appropriate value, the pressing pressure of the grindstone 11 against the workpiece 13 changes, causing the drive current of the grindstone drive motor 21 to deviate from a predetermined value, and this change in drive current is controlled. Detected by device 37.

When the control device 37 detects a change in the drive current of the grindstone drive motor 21, the control device 37
sends a command signal with content corresponding to the amount of change in the drive current to the stopper motor 34, and
Rotate. As the motor 34 rotates, the head stopper 33 moves an appropriate amount in the vertical direction relative to the main body 9.

Therefore, the stopper 33 rises if the surface of the workpiece 13 is a convex portion, and descends if the surface of the workpiece 13 is a concave portion. Along with this, the slider 19 also moves in the vertical direction. slider 1
The grinding wheel 1 is moved against the workpiece 13 by the vertical movement of the wheel 9.
The depth of cut 1 is corrected to an appropriate value, and the current of the grindstone drive motor 21 is thereby returned to the predetermined value. When the drive current of the motor 21 is maintained at a predetermined value, a stop command signal is sent from the control device 37 to the stopper motor 34, and by stopping the motor 34, the head 1 is stopped.
The second and other operations are also stopped, allowing stable grinding to be performed with high precision.

In this way, even when the workpiece 13 has an uneven surface, the stopper 33 presses and displaces the head 12 in the vertical direction, and the grindstone 11 freely follows the uneven surface of the workpiece 13, so that the cutting depth of the grindstone 11 can be adjusted. The amount is automatically corrected instantly.

Effects of the invention As described above, in the present invention, the head of the grinding wheel is attached to the pressing means via the lever, so even if the workpiece has an irregular shape with an uneven surface, the grinding wheel can be constantly applied to the workpiece in a cushioning manner. can.

Therefore, the grindstone is less likely to bounce compared to conventional grindstones, the surface roughness can be ensured, and the life of the grindstone can be maintained for a long time.

Furthermore, even if the pressing means is moved by the pressing driving means, since the head of the grinding wheel is attached to the pressing means via a lever, the movement will not be suddenly transmitted to the grinding wheel. Even if a super finishing machine has a means, it is possible to constantly apply the grindstone to the workpiece in a cushioning manner.

Further, according to the present invention, since the grindstone can be oscillated in a direction perpendicular to its rotational direction, the processing area can be increased even with the same size grindstone. Therefore, it is possible to improve surface processing accuracy.

[Brief explanation of the drawing]

Figures 1 to 3 show an embodiment of the processing mechanism of the super finishing machine according to the present invention, with Figure 1 being a front view thereof, Figure 2 being a side view, and Figure 3 being a vertical cross section of the head of the grindstone. 4 and 5 show a conventional example, with FIG. 4 being a front view and FIG. 5 being a side view. 11...Wheelstone, 12...Head, 13...Work, 14...Cylinder device, 17...Lever, 1
9...Slider, 21...Motor, 22...Spring, 23...Shaft, 24...Cam follower, 3
0...Eccentric pin, 33...Stopper.

Claims (1)

[Scope of utility model registration request] A head having a grindstone driven by a motor, a pressing means for moving the head in a direction in which the grindstone is pressed against a workpiece, an elastic member interposed between the pressing means and the head, the head In the processing mechanism of a super-finishing machine, the processing mechanism includes a pressing drive means for pressing and displacing in a direction opposite to the pressing direction, and a control device controlling the operation of the pressing driving means in accordance with a drive current of the motor. The head is fixed to one end of a lever pivotally connected to the pressing means, the elastic member is provided at a position to rotate the head together with the lever toward the workpiece, and the shaft of the grindstone is A cylindrical cam follower is loosely fitted and integrated with the shaft, a cam driven by another motor is installed in the head, and the cam is engaged with the cam follower. Processing mechanism of super finishing machine.