JPH0752038A - Rotary grinding machine - Google Patents

Abstract

PURPOSE:To unify the surface roughness of a ground face so as to improve appearance of a work ground face and reliability. CONSTITUTION:A detecting plate 8 having a slope 8a is fitted and fixed to a saddle 2, and a gap sensor 9 is mounted on a frame 1 opposite to the slope 8a. Hereby, when the saddle 2 is moved against the frame 1, the gap sensor 9 detects the distance between itself and the slope 8a of the detecting plate 8, and a controller C can discriminate the position of a table 7 against a grinding wheel 21 based on the detected value. It is constituted so that the rotating speed of the table 7 increases gradually as the rotational center position of the table 7 approaches the grinding wheel 21, and hence the circumferential speed of the table 7 can be set constant. In addition, the feed speed of the saddle 2 increases gradually as the rotational center position of the table 7 moves to the grinding wheel side, and hence the feed interval of the ground trace remaining on the ground face of a work W becomes constant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary grinder in which a table on which a work is placed rotates.

[0002]

2. Description of the Related Art In a rotary grinding machine, a saddle is supported by a frame so as to be capable of reciprocating. A table on which a work is placed is rotatably supported on the saddle. The grindstone for grinding the work is arranged above the table.

When grinding a work, the work is placed on the table, the table is rotated, and then the grindstone is lowered to bring the outer peripheral surface of the grindstone into contact with the outer upper surface of the work. In this state, the saddle is moved so that the contact position between the work and the grindstone is gradually moved from the work outer peripheral side to the work center side. Then, after the contact position reaches the work center side, the saddle is moved to the opposite side, and the contact position between the work and the grindstone is gradually moved from the work center side to the work outer peripheral side. That is, while the saddle is reciprocally moved, the grindstone is cut little by little to process the work to a predetermined size.

[0004]

However, the grinding state of the work ground by the rotary grinder differs between the inner circumference side and the outer circumference side of the rotation of the work. this is,
When the number of rotations of the table is constant, the peripheral speed becomes slower toward the inner circumference side of the table, and the grinding conditions change due to the interaction between the grinding wheel and the workpiece grinding surface and the interaction configured as described above. Is. This not only adversely affects the appearance of the ground surface, but also affects the reliability of products that use the ground work.

The present invention has been made to solve the above problems, and an object thereof is to make the grinding state of the grinding surface uniform and improve the appearance and reliability of the grinding surface of the work. It is to provide a possible rotary grinder.

[0006]

In order to achieve the above object, according to the invention of claim 1, a movable body arranged reciprocally on a frame and a positively rotatably supported on the movable body. A table, a grindstone for grinding a workpiece placed on the table, a table position detecting means for detecting a table position with respect to the grindstone, and a rotation of the table based on the table position detected by the table position detecting means. The gist of the present invention is that the number of moving objects and the moving speed of the moving object are changed.

According to a second aspect of the present invention, the variable means gradually increases the rotational speed of the table and gradually increases the moving speed of the moving body as the center of rotation of the table approaches the grindstone. Use as a summary.

According to another aspect of the invention, the table position detecting means is provided on the frame or the moving body, and has a detection plate having an inclined surface facing the frame or the moving body,
The gist of the invention is to provide a gap sensor that is provided on a frame or a moving body facing the slope of the detection plate and that detects a distance between the slope of the detection plate and itself.

A fourth aspect of the present invention is characterized in that the distance between the inclined surface of the detection plate and the gap sensor can be adjusted.

[0010]

According to the first aspect of the invention, when grinding the work on the table, first, in the state where the table is rotated,
A grindstone is brought into contact with the outer peripheral side of the work and a predetermined cut is made. Next, the moving body is moved to the grindstone side, and the rotation center of the table is brought closer to the grindstone. At this time, the table position is detected by the table position detecting means as the moving body moves. Then, the number of rotations of the table and the moving speed of the moving body are varied based on the table position.

According to the second aspect of the present invention, since the rotational speed of the table gradually increases as the position of the table rotation center moves to the grindstone side, the peripheral speed of the table becomes constant, and the work and the grindstone are separated. The contact time is uniformized. As a result, the surface roughness of the entire ground surface is made uniform. Also,
Since the moving speed of the moving body gradually increases as the table rotation center position approaches the grindstone, the feed interval of the grinding marks remaining on the grinding surface of the workpiece becomes a constant interval even if the rotation speed of the table increases.

According to the third aspect of the present invention, when the movable body is provided with the detection plate, the frame is provided with the gap sensor so as to face the slope of the detection plate. When the moving body moves relative to the frame, the gap sensor detects the distance (gap) between itself and the slope of the detection plate, and outputs the detection signal to the variable means. The variable means recognizes the table position based on the detection signal.

According to the invention of claim 4, since the distance between the slope of the detection plate and the gap sensor can be adjusted, the table rotation speed and the moving speed of the moving body with respect to the table position can be adjusted according to the grinding conditions and the like. Can be set arbitrarily.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a guide rail 3 (only one is shown) extending in the left-right direction is provided on the upper surface of the frame 1. A saddle 2 as a moving body is engaged with the guide rail 3, and the saddle 2 reciprocates left and right along the guide rail 3. A screw body 4 is provided on the lower surface of the saddle 2, and a screw shaft 5 is screwed on the screw body 4.
One end of the screw shaft 5 projects to the outside of the frame 1 and is connected to the saddle feeding motor 6 via a speed reducer (not shown). That is, the saddle 2 reciprocates left and right with respect to the frame 1 based on the rotation of the saddle feeding motor 6. A table 7 is supported on the upper surface of the saddle 2 by a vane motor 39, which will be described later, so as to be positively rotatable.
The table 7 is an electromagnetic chuck and fixes the work W by electromagnetic force.

Further, in the figure, on the front surface of the saddle 2,
A long plate-shaped detection plate 8 is fixed. An inclined surface 8a that rises to the right is formed on the lower surface of the detection plate 8, and the detection plate 8 reciprocates in the left-right direction integrally with the saddle 2. A gap sensor 9 composed of an ultrasonic proximity sensor is attached and fixed at a position of the frame 1 facing the inclined surface 8a of the detection plate 8. The gap sensor 9 detects the distance between the slope 8a of the detection plate 8 and itself, and outputs the detection signal to the controller C described later. The gap sensor 9 and the detection plate 8 constitute table position detection means.

A column 10 is erected on the right side of the frame 1, and a screw shaft 12 extending vertically is provided below the column 10. A threaded body 13 is threadedly engaged with the lower end of the screw shaft 12, and the threaded body 13 rotates with the driving of a lifting motor 14 such as a geared motor. On the other hand, a cylindrical slider 16 is mounted on the upper end of the screw shaft 13 via a bearing 15.
Are connected. A grindstone shaft 17 is fixed to the slider 16.

A grindstone 21 for grinding the work W is rotatably supported at the front end of the grindstone shaft 17. The grindstone 21 is positively rotated by a motor 22 attached to the rear end of the grindstone shaft 17. The slider 16 and the grindstone shaft 17 move up and down as the lifting motor 14 rotates forward and backward. That is, the distance between the grindstone 21 and the table 7 changes as the lifting motor 14 rotates forward and backward.

Next, the drive device for the table 7 will be described in detail. As shown in FIG. 2, the table 7 is formed in a disc shape, and a pulley 31 is connected to the outer peripheral portion of the lower surface thereof. A disk-shaped sliding body 32 having a convex cross-section is connected to the inner peripheral surface of the lower surface of the table 7 by a bolt (not shown). The sliding body 32 is slidably accommodated in a disk-shaped body 33. Lubricating oil supply holes 34 are formed at a plurality of positions on the lower surface of the body 33. Each lubricating oil supply hole 34 is communicated with a plurality of lubricating oil ejection holes 36 opening on the inner surface of the body 33 via a communication passage 35.

A static pressure generating pump P is connected to the lubricating oil supply passage 33, and the lubricating oil is pumped from the pump P to the lubricating oil supply passage 34. And
The lubricating oil pumped to the lubricating oil supply passage 34 is connected to the communication passage 3
After passing through 5, the lubricating oil is blown out from each lubricating oil ejection hole 36 between the inner surface of the body 33 and the sliding body 32. As a result, static pressure is generated between the sliding body 32 and the body 33, and the sliding body 32, that is, the table 7 rotates smoothly with respect to the body 33. Also saddle 2
A rotation speed sensor 37 for detecting the rotation speed of the table 7 is attached to the.

As shown in FIG. 3, a two-way vane motor 39 as a hydraulic motor is connected to the side surface of the saddle 2 via a bracket 38. A pulley 40 is attached to a rotary shaft 39a of the vane motor 39. The pulley 40 and the pulley 31 attached to the lower surface of the table 7 are connected via a belt 41. The vane motor 39 is an electromagnetic switching valve 4
It is connected to the variable displacement pump 43 of the swash plate type via 2. The variable displacement pump 43 is driven by a pump motor 44.

The switching valve 42 connects the variable displacement pump 43 and the vane motor 39 to each other when the voltage application is stopped.
The FF side block 42a and the ON side block 4 that connects the variable displacement pump 43 and the vane motor 39 to each other when a voltage is applied.
It is composed of two blocks 2b and 2b. And
When the variable displacement pump 43 and the vane motor 39 are communicated with each other by the OFF-side block 42a of the switching valve 42, hydraulic oil is supplied from the pipe P1 into the vane motor 39, and the vane motor 39 has a solid arrow. Rotate in the direction. Therefore, in this case, the rotation direction of the table 7 is also the same as the rotation direction of the vane motor 39. On the contrary, when the variable displacement pump 43 and the vane motor 39 are communicated with each other by the ON-side block 42b, hydraulic oil is supplied from the pipe P2 into the vane motor 39,
The vane motor 39 and the table 7 rotate in the direction of the chain line arrow.

Next, the electrical construction of the rotary grinder is shown in FIG.
It will be described based on the block diagram of FIG. The controller C
Is a central processing unit (CPU) 51, a ROM 52 for storing control programs and the like, and a RAM 53 for storing calculation results and the like.
Etc.

The gap sensor 9 is connected to the input side of the CPU 51. The gap sensor 9 detects a distance (gap) between itself and the slope 8a of the detection plate 8 fixed to the saddle 2, and outputs a detection signal corresponding to the distance to the CPU 51. That is, the gap sensor 9 indicates the movement amount of the saddle 2 with respect to the frame 1 by the CPU 51.
Output to. A rotation speed sensor 37 is connected to the input side of the CPU 51. The rotation speed sensor 37 detects the rotation speed of the table 7 and outputs the detection signal to the CPU 51.
Output to.

On the other hand, the switching valve 42 is connected to the output side of the CPU 51, and the switching valve 42 is controlled to switch to the OFF block 42a position or the ON block 42b position based on the CPU 51 output signal (voltage application stop or voltage application). To be done. Further, a swash plate driving motor 55 that changes the tilt angle of a swash plate (not shown) of the variable displacement pump 43 is connected to the output side of the CPU 51. After the detection signal from the gap sensor 9 is input, the CPU 51 drives and controls the swash plate driving motor 55 based on the map A (see FIG. 5A) stored in the ROM 52, and the vane motor 39.
Adjust the amount of hydraulic oil to be sent to. That is, the rotation speed of the vane motor 39 is changed. The map A sets a target table rotation speed for the saddle 2 position (table 7 position), and is set so that the rotation speed of the table 7 increases as the rotation center position of the table 7 approaches the grindstone 21. ing.

Further, a saddle feed motor 6 is connected to the output side of the CPU 51. The CPU 51 inputs the detection signal from the gap sensor 9 and then the ROM 5
The saddle feed motor 6 is driven and controlled based on the map B (see FIG. 5B) stored in No. 2 to change the feed speed of the saddle 2. The map B sets the target saddle feed speed for the position of the table 7, and is set so that the feed speed of the saddle 2 increases as the rotation center position of the table 7 approaches the grindstone 21.

Next, the operation of the rotary grinder constructed as described above will be described. FIG. 6 is a flow chart showing a control processing routine executed by the CPU 51 of the controller C in the present embodiment, which is executed by a regular interruption at every predetermined time.

First, in step 101, each pump is driven to start preparation for grinding. In step 102, the CPU 51 inputs the detection signal from the gap sensor 9, that is, the position of the table 7 with respect to the grindstone 21. In step 103, the detection signal from the rotation speed sensor 37, that is, the rotation speed of the table 7 is input. Continue,
In step 104, the CPU 51 calculates the target table rotation speed for the current position of the table 7 based on the map A stored in the ROM 52. Further, in step 105, the CPU 51 calculates the target saddle feed speed for the current table 7 position.

Then, in step 106, the CPU 5
In step 1, the swash plate driving motor 55 is drive-controlled to adjust the hydraulic oil to be pressure-fed to the vane motor 39 so as to rotate the table 7 at the target table rotation speed calculated in step 104. As a result, the rotation speed of the vane motor 39 becomes the predetermined rotation speed, and accordingly, the rotation speed of the table 7 is controlled to the predetermined rotation speed. Further, in step 107, the CPU 51 drives and controls the saddle feed motor 6 to move the saddle 2 at the target saddle feed speed calculated in step 105. As a result, the saddle 2 is sent to the grindstone 21 at a predetermined speed.

Then, in step 108, the CPU 5
1 determines whether the table 2 has moved to a predetermined position (for example, the table rotation center position). Where CP
When the U51 determines that the table 7 has moved to the predetermined position, the process proceeds to the next step 109. On the other hand, when it is determined that the table 7 has not moved to the predetermined position, the process returns to step 102 and the subsequent processes are repeated.

At step 109, the CPU 51 determines whether or not the grinding is completed. Here, when the controller C determines that the grinding has not been completed yet, the process proceeds to step 110, and the saddle feed motor 6 is reversely driven in order to reverse the current feed direction of the saddle 2. . After that, the CPU 51 returns to step 102 and repeats the subsequent processing. On the other hand, when the CPU 51 determines in each step 109 that the grinding is completed,
The drive of each motor and the like is stopped, and the subsequent processing is ended.

As described above, in this embodiment, the detection plate 8 having the slope 8a is attached and fixed to the saddle 2, and the gap sensor 9 is attached to the frame 1 facing the slope 8a. As a result, when the saddle 2 moves with respect to the frame 1, the gap sensor 9 detects the distance between itself and the slope 8a of the detection plate 8, and the controller C controls the grindstone 21 based on the detected value. The position of the table 7 can be determined. Since the rotation speed of the table 7 gradually increases as the rotation center position of the table 7 approaches the grindstone 21, the peripheral speed of the table 7 can be kept constant. As a result, the work W and the grindstone 21
The contact time with and is made uniform, and the surface roughness of the entire ground surface of the work W is made uniform. Further, since the feed speed of the saddle 2 gradually increases as the rotation center position of the table 7 moves toward the grindstone side, the feed interval of the grinding marks remaining on the ground surface of the work W becomes a constant interval (see FIG. 7). ). as a result,
The ground surface of the work W has a beautiful finish and is excellent in accuracy. In addition, in this embodiment, the table 7
Since the inexpensive detection plate 8 and the gap sensor 9 are used to detect the position of, the cost is excellent.

Further, in this embodiment, the variable displacement pump 4
3 is used to drive the vane motor 39. Accordingly, even when the rotation speed of the table 7 (vane motor 39) is changed, only the rotation speed can be changed without changing the torque. Thereby, even if the rotation speed of the table 7 changes, the workpiece W can be ground from the outer peripheral side to the inner peripheral side under substantially the same grinding conditions.

The present invention is not limited to the above embodiments, but may be configured as follows, for example, without departing from the spirit of the invention. (1) In the above embodiment, the vane motor 39 is embodied, but a gear motor other than the vane motor 39, a gee rotor motor, a piston motor, or the like may be embodied.

(2) In the above embodiment, the gap sensor 9
Although it is constituted by an ultrasonic proximity sensor, it may be embodied by a photoelectric proximity sensor or an electrostatic or inductive proximity sensor. (3) The table position detecting means may be composed of a rotary encoder, a potentiometer, or the like. In this case, by engaging these with the screw shaft 5 that feeds the saddle 2 and detecting the amount of rotation of the screw shaft 5, the position of the saddle 2, that is, the position of the table 7 can be detected. Further, the position of the table 7 can be detected even if the motor 6 for rotating the screw shaft 5 is constituted by a step motor. Further, the table position detecting means may be configured by a digital smooth scale.

(4) In the above embodiment, the detection plate 8 is installed on the saddle 2 as a moving body, and the gap sensor 9 is installed on the frame 1. However, the mounting relationship may be reversed.

(5) In the above embodiment, the vane motor 39
The swash plate type variable displacement pump 43 was used as the pump for pumping the hydraulic oil to the above, and the rotation speed of the vane motor 39 was varied by adjusting the swash plate angle. The hydraulic oil pumped from the pump may be variable using a servo valve or the like.

(6) In the above embodiment, the distance between the detection plate 8 and the gap sensor 9 could not be adjusted, but this may be embodied as an adjustable structure. That is, as shown in FIG.
1 supports the saddle 2 rotatably. on the other hand,
An arc-shaped long hole 62 is formed on the other end side of the detection plate 8. Then, the bolt 63 is inserted into the long hole 62, and the bolt 62 is screwed into a screw hole (not shown) formed in the saddle 2 to position the detection plate 8 with respect to the saddle 2. When adjusting the distance between the gap sensor 9 and the slope 8 of the detection plate 8, this can be done by loosening the bolt 63 and rotating the detection plate 8.

[0038]

As described in detail above, according to the present invention,
Since the position of the table with respect to the grindstone can be reliably detected with a simple configuration, it is possible to improve the appearance and reliability of the work grinding surface by reducing the cost and making the surface roughness of the grinding surface uniform. It has an excellent effect that

[Brief description of drawings]

FIG. 1 is a front view of a rotary grinding machine according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a table and a table support portion.

FIG. 3 is a partial side view of a rotary grinder.

FIG. 4 is a block diagram showing an electrical configuration.

FIG. 5A is a map in which a target table rotation speed is set for a table position, and FIG. 5B is a map in which a target saddle feed speed is set for a table position.

FIG. 6 is a flowchart showing the operation of the CPU.

FIG. 7 is a schematic plan view of a work W after grinding.

FIG. 8 is a partial front view of a rotary grinder showing a mounting structure of a detection plate 8 of another example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Frame, 2 ... Saddle as a moving body, 6 ... Saddle feed motor constituting variable means, 7 ... Table, 8 ...
A detection plate constituting the table position detection means, 8a ...
9 ... Gap sensor which constitutes table position detecting means,
21 ... Whetstone, 39 ... Vane motor constituting variable means,
43 ... Variable displacement pump forming variable means, C ... Controller forming variable means, W ... Work

Claims (4)

[Claims] 1. A moving body (2) reciprocally arranged on a frame (1), a table (7) rotatably supported on the moving body (2), and a table (7). ) A grindstone (21) for grinding a work (W) placed on the table, table position detecting means (8, 9) for detecting the position of the table (7) with respect to the grindstone (21), and the table position detecting means Based on the position of the table (7) detected by (8, 9), variable means (6, 6) for varying the rotation speed of the table (7) and the moving speed of the moving body (2).
43, 39, C) and a rotary grinding machine. 2. The variable means (6, 43, 39, C)
Is characterized in that the rotation speed of the table (7) is gradually increased and the moving speed of the moving body (2) is gradually increased as the rotation center position of the table (7) approaches the grindstone (21). The rotary grinder according to Item 1. 3. The table position detecting means (8, 9)
Is provided on the frame (1) or the moving body (2),
A detection plate (8) having a slope (8a) facing the frame (1) or the moving body (2), and a frame (1) or a moving body (8) facing the slope (8a) of the detection plate (8). 2)
The rotary grinding according to claim 1 or 2, further comprising: a gap sensor (9) provided on the slope plate (8a) of the detection plate (8) and detecting a distance between the slope plate (8a) and itself. Board. 4. The rotary grinding machine according to claim 3, wherein the distance between the slope of the detection plate (8) and the gap sensor (9) is adjustable.