JPS6119388B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION In the present invention, a rotating grindstone is attached to the free end of an arm configured to freely tilt, and by tilting the arm, the rotating grindstone is brought into contact with a material to be ground, and the material is ground. This is related to the grinding position.

In this type of grinding device, as the rotary grindstone wears and its diameter changes, the rotation axis of the grindstone moves on an arc centered on the pivot point of the arm. For this reason, the point of contact of the grinding wheel on the material to be ground will move sequentially as the diameter of the grinding wheel changes, and even if the part to be ground on the material to be ground is always brought to the same position, the part to be ground will not be correct. I had a problem with it becoming difficult to remove.

Therefore, the present invention aims to solve the above-mentioned problems, and even if the rotary whetstone is worn out and its diameter changes, it is possible to always bring the rotary whetstone into contact with a constant position on the material to be ground. , it is an object of the present invention to provide a grinding position that enables accurate grinding of a part to be ground.

The drawings showing the embodiments of the present application will be described below. Reference numeral 1 denotes an elevating board, which is configured to be movable up and down (up and down in FIG. 1) using a well-known mechanism not shown on a base body not shown. Reference numeral 2 denotes a cylinder for raising and lowering the lifting board 1, which is connected to a base body (not shown), and its advancing/retracting rod 2a is connected to the lifting board 1. 3 shows a hydraulic circuit for driving the cylinder 2. Incidentally, these cylinders 2 and hydraulic circuit 3 constitute an elevating device for the elevating board 1. Reference numeral 4 denotes a lift plate vertical position detection device, which includes a main body 5 connected to a base (not shown) and a pinion 6 fixed to the rotating shaft of the main body 5.
and a detection piece 7 attached to the elevator plate 1. The main body 5 is configured to output an electrical signal corresponding to the state of its rotation axis (rotated angle) (for example, an encoder is used), and the detection piece 7 is provided with rack teeth 7a. ,
The rack tooth 7a is meshed with the pinion 6.

Next, 9 indicates the arm, and its pivot point is 1
0, it is pivoted to the elevator plate 1 and is configured to swing freely in a vertical plane. Reference numeral 11 indicates a rotary grindstone rotatably attached to the tip of the arm 9 with its own rotating shaft 11a, reference numeral 12 indicates a grinding position, and reference numeral 13 indicates a workpiece 13 placed at the grinding position 12. Note that the grinding position 12 is set, for example, on the base body. In addition, when the arm 9 is in a horizontal state, the grindstone 11 has its rotation axis 11a positioned directly above the center of the workpiece 13 placed at the grinding position 12, that is, on a vertical line passing through the center. I'm planning on coming. Reference numeral 14 denotes a grindstone rotation motor fixed to the arm 9, which is capable of rotationally driving the grindstone 11 via a belt 15. Reference numeral 17 denotes a cylinder for tilting the arm 9, which is fixed to the elevator plate 1 by well-known means, although not shown, and its advance/retreat rod 17a.
is connected to the rear end of arm 9. Reference numeral 18 indicates a hydraulic circuit for driving the cylinder 17. The cylinder 17 and the hydraulic circuit 18 constitute a tilting device for the arm 9. Reference numeral 20 indicates an arm tilt detection device, in which 21 is a main body fixed to the elevator platform 1, and is configured to output an electrical signal corresponding to the state of its rotation axis (rotated angle). . Note that as this main body 21, for example, an encoder is used. 22 is a pinion fixed to the rotating shaft of the main body 21, and 23 is a detection piece fixed to the arm 9, which is formed in an arc shape centered on the position of the pivot shaft 10. Further, the inner circumferential surface of this detection piece 23 is carved with a rack tooth 23a, and the rack tooth 23a meshes with the pinion 22.

Next, 24 is a grindstone rotation motor load current discrimination circuit, which is exemplified as a contact detection device, and as shown in FIG. In addition to detecting contact, the separation of the grindstone 11 from the material to be ground 13 is detected by detecting a decrease in current as shown in (b). As this contact detection device, a device that optically detects sparks generated when the grindstone 14 comes into contact with the material to be ground 13 to grind it may be used. 2
5 is an arm tilting input circuit, and 26 is an elevator vertical position input circuit.

Next, 27 indicates a control device, in which 2
8 is an automatic scratch removal machine control circuit, 29 is a control calculation circuit,
Reference numeral 30 denotes a distance setting device, which is provided to set the distance between the workpiece 13 and the grindstone 11 in a non-grinding state.

Reference numeral 31 denotes a lifting plate vertical movement command circuit, and 32 represents a grindstone vertical movement command circuit. These members constituting the control device 27 are configured to perform operations as described below.

In the case of the above structure, when the grindstone 11 is retracted above the grinding position 12,
A material to be ground 13 such as a round bar-shaped steel material is placed at a grinding position 12 .

In this case, the part to be ground 13a in the material to be ground 13
In other words, the part where there are scratches to be ground is the material to be ground 1.
It is positioned at the top of 3. When the material to be ground 13 is placed at the grinding position 12 in this way, a signal to start operation is given from the control circuit 28 to the control calculation circuit 29. Then, the control calculation circuit 29 gives a command to the command circuit 32 to lower the grindstone 11. As a result, the hydraulic circuit 18 is connected to the command circuit 32.
The forward and backward movement lever 17a of the cylinder 17 is controlled to move upward. Therefore, the grindstone 11 descends and eventually comes into contact with the material to be ground 13 to grind it.

In this case, if the arm 9 is not in a horizontal state as shown in FIG. 1 when the grinding wheel 11 is in contact with the material to be ground 13, the following operation is performed to ensure that the arm 9 is always in a horizontal state. be made to be. That is, when the grinding wheel 11 comes into contact with the material to be ground 13 as described above, the current of the motor 14 increases as shown in FIG. It is detected that the material has come into contact with the material to be ground 13. At this time, the angle signal inputted from the main body 21 of the arm tilt detection device 20 to the control calculation circuit 29 via the input circuit 25 is the reference signal inputted and stored in advance to the control calculation circuit 29, that is, the arm 9 is horizontal. If the angle signal is different from the angle signal input from the main body 21 via the input circuit 25 when the state is in the state, a command to raise and lower the elevator platform 1 (to lower it in the state shown in FIG. 1) is sent from the control calculation circuit 29 to the command circuit. Given to 31. Then, the hydraulic circuit 3 is controlled by the command circuit 31 and operates to lower the advance/retreat rod 2a of the cylinder 2.
As a result, the elevator plate 1 descends. In the case of this lowering, the cylinder 17 and the hydraulic circuit 18 operate in accordance with this so that the contact pressure of the grindstone 11 with respect to the material to be ground 13 is always maintained at an appropriate value. Such a lift board 1
When the arm 9 becomes horizontal due to the lowering of the arm 9, and the signal input from the main body 21 of the arm tilt detection device 20 to the control calculation circuit 29 via the input circuit 25 matches the above-mentioned pre-stored signal, the control calculation starts. Under the control of the circuit 29, the lowering of the elevator platform 1 is stopped. Therefore, the grindstone 11 is brought into contact with the top of the material to be ground 13 correctly.

Incidentally, since such an operation is repeated each time the grindstone 11 grinds the material to be ground 13 brought to the grinding position 12, the amount that the elevator plate 1 is moved up and down at one time is only a small amount. Therefore, the grindstone 11 is the material to be ground 13
Always touch the top of the

When the grindstone 11 comes into contact with the material to be ground 13 and grinds the part to be ground 13a to the required depth in this manner, the control calculation circuit 29 gives a command to the command circuit 32 to raise the grindstone. Then, the hydraulic circuit 18 is controlled by the command circuit 32 to move the cylinder 17 forward/backward lever 17a.
It operates to lower the. As a result, grinding wheel 1
1 is lifted out of contact with the material to be ground 13. This lifting is carried out between the workpiece 13 and the grinding wheel 11.
The process is performed in the following manner until the distance between the distance and the distance reaches a value predetermined in the distance setting device 30. That is, when the grindstone 11 separates from the workpiece 13 in the process of rising, the current of the motor 14 decreases as shown in FIG. 2B, and this is detected by the discrimination circuit 24. At this point, in the control calculation circuit 29, the main body 21 of the detection device 20
A slope signal input from the input circuit 25 through the input circuit 25 is temporarily stored.

Then, the arm 9 tilts and the grindstone 11 rises,
The difference between the inclination signal that is input from the main body 21 to the control calculation circuit 29 via the input circuit 25 while changing from moment to moment and the above-mentioned temporarily stored inclination signal is set in advance in the interval setter 30. When the value corresponding to the previous value is reached, a stop command is given from the control calculation circuit 29 to the command circuit 32, and the raising of the grindstone 11 is stopped.

By repeating the above operations, the material to be ground 13 is ground one after another.

In addition, in the above-mentioned apparatus, since the lift plate is always moving to the position where the grinding wheel 11 contacts the workpiece 13 with the arm 9 horizontal, the lift plate vertical position detection device is required. It is also possible to know from the signal from the main body 5 of 4 that the grindstone 11 is worn out and that it is time to replace it.

Further, in the above embodiment, the arm 9 is always in a horizontal state when the rotary whetstone 11 comes into contact with the workpiece 13, so that the grindstone 11 always comes into contact with the top of the workpiece 13. However, even if the state of arm 9 at this time is not horizontal,
Exactly the same effect can be obtained by always making the slope the same.

Next, FIG. 3 shows an example in which a mechanism for keeping the circumferential speed of the rotary grindstone constant when it rotates is added to the apparatus shown in FIG. 1. In the figure, a signal from the main body 5 of the elevator vertical position detection device 4, that is, a signal corresponding to the diameter of the grinding wheel 11 is transmitted to the control calculation circuit 29.
When the signal is input to the grinding wheel rotation speed control circuit 33 via the signal, this control circuit 33 sends out a signal to set the rotation speed of the rotating grindstone 11 to a value that keeps its circumferential speed constant according to the signal. do. Then, the grindstone motor drive device 34 controls the rotation of the motor 14 so that the rotation speed of the motor 14 corresponds to the signal. Thereby, the circumferential speed of the rotary grindstone 11 is made constant, and the amount of grinding is stabilized.

As described above, in this invention, the rotary whetstone 11 is brought into contact with the material to be ground 13 by tilting the arm 9, and if the diameter of the rotary whetstone 11 changes, the grinding wheel 11 is brought into contact with the material to be ground 13. Even if the grinding wheel 11 has a structure in which the contact position changes, when the rotary whetstone 11 contacts the workpiece 13, the rotation axis 11a will be on the vertical line passing through the center of the workpiece 13. Therefore, for example, rotating whetstone 1
Even if the diameter of the grinding wheel 1 becomes smaller due to wear, the rotary grindstone 11 can always be brought into contact with the top of the workpiece 13. This allows the grindstone 13a of the workpiece 13 to be accurately ground (without positional deviation). It has the advantage that it can be scraped (without cutting) and the quality of the product can be improved.

[Brief explanation of the drawing]

The drawings show an embodiment of the present application, and FIG. 1 is a diagram showing the main parts of the grinding device and the relationship between this and the control device, FIG. 2 is a diagram showing changes in motor current over time,
FIG. 3 is a diagram similar to FIG. 1 showing a different embodiment. 1...Elevating board, 9...Arm, 10...Pivot,
11... Rotating grindstone, 11a... Rotating shaft, 12...
Grinding position, 13... material to be ground, 20... tilt detection device.

Claims (1)

[Claims] 1. A rotary whetstone whose rotating shaft is attached to the free end of an arm is disposed above the round bar-shaped workpiece placed in the grinding position, and the arm moves the rotary whetstone to the grinding position. The arm is tiltably pivoted about its own pivot point so that it can come into contact with the workpiece being placed, and the pivot point is supported by a base body, and the arm is also provided with a tilting mechanism. A tilting device is attached, and by operating the tilting device, the arm is tilted to bring the rotary grindstone into contact with the workpiece placed at the grinding position, and the workpiece is ground by the rotary whetstone. In the grinding apparatus, a lifting plate is attached to the base body so as to be able to move up and down, and the lifting plate is attached with a lifting device for raising and lowering the plate, and a pivot point of the arm is attached to the lifting plate. is pivotally connected to the lifting plate so that it can be supported on the base via the lifting plate, and the pivoting position is such that the arm is tilted and the rotary grindstone is placed in the grinding position. The rotational axis of the rotary grindstone is selected to be in a position along a straight line passing through the center of the workpiece when it is in contact with the workpiece, and the elevating plate has a tilt angle of the arm. The main body side of the inclination detection device configured to detect is attached, while the detection piece of the inclination detection device is connected to the arm, and furthermore, the rotating grindstone is in contact with the material to be ground. The inclination detecting device and the abutting detecting device further include a contact detecting device capable of detecting the inclination detecting device, and the inclination detecting device and the abutting detecting device have a contact detecting device capable of detecting the inclination detecting device. A control device is connected that detects the presence or absence of a change in the inclination signal of the above-mentioned device and provides an output to the elevating device to operate the elevating device in the direction in which the change disappears if there is a change. Grinding position characterized by.