JPH11114819A - Tool grinding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the cutting edge of a tool from chipping or a grinding wheel itself from being damaged even if the grinding performance of the grinding wheel has degraded when a superhard tool, in particular a diamond tool, is ground by a grinding wheel. SOLUTION: A grinder is equipped with a holder 14 to hold a cutting tool 16 and a wheel head 18 to grind the surface 16a of the tool held by the holder. The configuration includes a cut-in table 34 installed on a frame 12 in such a way as contacting with and separating from the tool and moved under the numerical control, wherein the wheel head 18 is installed on the cut-in table 34 and arranged as capable of approaching and separating from the tool, and also a pressing means 46 which is installed on the cut-in table and presses and restricts the wheel head 18 to the proximity position directed toward the tool at normal times. The wheel head 18 is fitted with a grinding wheel 20 which performs grinding of the tool, and the pressing force of the pressing means 46 is made adjustable so that the head 18 can move in the direction of going apart under the reactive action to the grinding pressure when a grinding pressure exceeding the specified value is applied to the wheel 20 during the grinding work for the tool.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool grinder, and more particularly, to cutting and grinding a tool with a rotary grindstone, even if the grinding performance of the grindstone is reduced, the cutting edge of the tool is chipped. The present invention relates to a grinding machine capable of grinding the tool in a good condition without generating or damaging the grindstone itself.

[0002]

2. Description of the Related Art A polycrystalline diamond sintered body (PC
D) or cubic boron nitride (CBN) sintered compacts, ultra-hard materials such as ceramics, etc., are used to improve the workability and durability of difficult-to-machine materials. It is suitably used as a rotary blade in a processing machine. When the cutting performance of the ultra-high-hardness tool decreases with use, it is necessary to recover the cutting performance by grinding the cutting edge at the cutting edge with a rotary grindstone. In this case, since the cutting edge of the tool is made of a diamond sintered body or a material having a hardness equivalent thereto as described above, a diamond grindstone is generally used as a rotary grindstone for grinding the same. Also, a tool grinder is known as a device which holds an ultra-hard tool by a holder and grinds a cutting edge (ground surface) of the tool with the diamond grindstone to restore the cutting performance of the tool.

[0003]

However, since there is almost no difference in hardness between the cutting edge material of the ultra-high hardness tool and the diamond grindstone, when the tool is ground with the tool grinder, the sharpness of the grindstone is good. Even in this state, effective grinding cannot be achieved unless a considerable grinding pressure is applied to the surface to be ground of the tool edge. For this reason, when the sharpness of the whetstone is reduced, if the incision grinding with the whetstone for the ultra-hard tool is continued, the grinding surface of the tool cannot be ground and removed by an amount corresponding to the amount of cut of the whetstone. However, the grinding pressure acting between the two increases only. Excessive increase in the grinding pressure results in harmful chipping of the cutting edge of the tool, and also has the disadvantage of causing damage to the grindstone itself.

[0004]

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above-mentioned drawbacks inherent in conventional tool grinders, and has been proposed to solve the problem suitably. Even if the grinding performance of a rotary grindstone is reduced, it is possible to provide a tool grinder that can always perform grinding of the tool in a good state without causing chipping of the tool or damaging the rotary grindstone itself. Aim. Another object of the present invention is to grind an ultra-hard tool, particularly a diamond tool, with a tool grinder, and detect that the grinding performance of the rotary grindstone has decreased, and to shift to a timely dressing for the grindstone. It is to provide a grinding machine.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems and appropriately achieve the intended purpose, the present invention provides a holder for rotatably indexing a surface to be ground of a tool, and a holder for holding the grinding surface. A tool grinding machine having a grinding wheel head for cutting and grinding the surface to be ground of the tool, wherein the tool is disposed on a frame so as to be movable close to and away from the tool held by the holder, A cutting table to which movement is provided, the grinding head mounted on the cutting table, and movable close to and away from a tool held by the holder; and Pressing means for restricting pressing to a position close to the tool held by the grinding wheel, and a grinding pressure exceeding a predetermined value is applied to the rotating grindstone during the grinding of the tool by the rotating grindstone of the grindstone head. Then, characterized in that adjustably constructed the pressing force of the pressing means as may be moved to the separated direction whetstone head reaction under the grinding pressure.

Another object of the present invention is to solve the above-mentioned problem and to appropriately achieve another intended object by providing a holder for rotatably indexing a surface to be ground of a tool and a holder for holding the surface to be ground. In a tool grinding machine having a grinding head for cutting and grinding the surface to be ground of the tool, and a dresser for dressing a rotating grindstone provided in the grinding head, the tool can be moved close to and away from the tool held by the holder. A notch provided on the frame and provided with the approach / separation movement by numerical control, the whetstone head installed on the notch, and movable close to / separate from a tool held by the holder; A pressing means disposed on a table, for always pressing the whetstone head to a position close to a tool held by the holder, and pressing means for pressing against the pressing force of the pressing means. When the stone head moves in a direction away from the tool, a sensor that detects the movement and outputs a signal is provided, and during the grinding of the tool by the rotating grindstone, the rotating grindstone has a predetermined value. When the pressure acts, the pressing force of the pressing means can be adjusted so that the grinding head can be moved in the separating direction under the reaction of the grinding pressure, and the movement of the grinding head in the separating direction is detected by the sensor. The dresser is configured to dress the rotating grindstone.

[0007]

In the tool grinding machine according to the present invention, if a grinding pressure exceeding a predetermined value acts on the rotating grindstone during grinding of the ultra-hard tool by the rotating grindstone, the grinding wheel head is acted upon by the reaction of the grinding pressure. Moving in the separating direction, the grinding pressure exceeding a predetermined value disappears instantaneously. Also, when a grinding pressure exceeding a predetermined value acts on the rotating grindstone, the grindstone head moves in the separating direction,
By detecting this movement with a sensor, the head is moved toward the dresser to automatically perform dressing.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a tool grinding machine according to the present invention will be described with reference to the accompanying drawings, using a preferred embodiment using a tool made of polycrystalline diamond (PCD). FIG. 1 is a schematic right side view of a tool grinder according to a preferred embodiment. The tool grinder 10 is held by a tool holder 14 disposed on a side of a main body frame 12 and the holder 14. For example, it is basically composed of a grindstone head 18 for cutting and grinding a diamond tool 16 typified by a vertical groove cutter for woodwork. That is, the holder 14 is provided with an index mechanism (not shown) inside so that the diamond tool 16 can be rotatably indexed on the surface 16a to be ground, which is an individual cutting edge. In addition, whetstone head 1
Reference numeral 8 denotes a diamond grinding stone 20 having a rotation center held horizontally.
Is provided, and the grinding surface 20a of the whetstone 20 is
4 is directed to the surface 16a to be ground of the diamond tool 16 held. A motor 22 is provided on the side of the grindstone head 18 opposite to the side on which the grindstone is provided, and the rotation output from the motor 22 is transmitted to the diamond grindstone 20. As described later, the grinding head 18 can move linearly toward and away from the diamond tool 16 held by the holder 14 (in the Z direction in plane coordinates).

On the upper surface of the main body frame 12, two guide rails 24 are provided horizontally and parallel in a direction (X direction in plane coordinates) perpendicular to the moving direction (Z direction) of the grinding wheel head 18. A movable table 28 is mounted on these guide rails 24, 24 via respective corresponding sliders 26, 26 so as to be slidable in the X direction. A feed nut 30 having a female screw threaded in the direction in which the guide rail 24 extends is provided at the bottom of the movable base 28, and a feed screw 32 is rotatably screwed into the feed nut 30. Feed screw 32
Is rotated by a numerically controlled (NC) servomotor (not shown) in the forward and reverse directions, whereby the movable table 28 can be reciprocated in the X direction on the guide rails 24, 24. The reciprocating movement of the movable table 28 in the X direction is performed at the time of grinding the diamond tool 16 by the grindstone 20 and at the time of dressing the grindstone 20 described later.

Next, a notch table 34 is provided on the movable table 28, and the notch table 34 is
The tool is movable close to and away from the diamond tool 16 held at a predetermined distance. That is, guide rails 36, 36 are horizontally and parallelly arranged in the Z direction on the upper surface of the moving table 28, and the notches 34 are formed on the guide rails 36, 36 via the corresponding sliders 38, 38, respectively. It is slidably mounted in the direction. A feed nut 40 having a female screw threaded in the direction in which the guide rail 36 extends is provided at the bottom of the cut table 34, and a feed screw 42 is rotatably screwed into the feed nut 40. This feed screw 4
Numeral 2 is connected to a servo motor 44 which is numerically controlled (NC), and the feed screw 42 is rotated forward and reverse by this motor, so that the cut table 34 is guided by guide rails 36, 36.
Above, it can reciprocate in the Z direction.

The grinding head 18 is provided with the cutting table 34.
And is movable in the Z direction by a small amount toward and away from the diamond tool 16 held by the holder 14. For example, in FIG. 2, a concave groove 18 a extending in the Z direction is formed on the lower surface of the grinding wheel head 18, and a ridge 34 a also extending in the Z direction is formed on the upper surface of the cutting table 34. And the groove 1
8a is slidably fitted to the ridge 34a,
The whetstone head 18 is allowed to move in the Z direction with respect to the cutting table 34. A linear slide roller (not shown) is provided between the groove 18a and the ridge 34a so as to reduce frictional resistance and respond sharply to a grinding pressure described later. Also, as shown in FIG.
The right and left ends in the Z direction are integrally formed with restricting pieces 18b and 18c, respectively, which hang down therefrom and extend inward. The right regulating piece 18b regulates, at a fixed position, the movement of the grinding head 18 to the left in the Z direction with respect to the cutting table 34. The left regulating piece 18c indicates that the grinding head 18 It has a function of restricting movement to the right in the direction at a fixed position.

In FIG. 1, an air cylinder (pressing means) 46 is provided horizontally on the right side of the cutting table 34 to constantly restrict the grinding head 18 to a position close to the diamond tool 16 held by the holder 14. The free end of a piston 48 extending leftward from the cylinder 46 is
It can contact the right side of the grinding head 18. Then, air pressure is supplied to the air cylinder 46 so that the piston 48
When the grindstone head 18 is urged to the left,
The whetstone head 18 is slightly moved to the left on the upper side, and the movement of the whetstone head 18 is regulated at a fixed position by the right regulating piece 18b of the cutting board 34. That is, while the predetermined air pressure is being supplied to the air cylinder 46, the grinding wheel head 18 is always urged toward the diamond tool 16 held by the holder 14 and is integrated with the cutting table 34 in the Z direction. Can be moved close to and away from. A pressure adjusting device such as a pressure reducing valve capable of continuously or stepwise adjusting the pressure setting is provided in a pipe connecting the air cylinder 46 and the air pressure source.
(Not shown) is inserted. As will be described later, when a grinding pressure exceeding a predetermined value acts during the grinding of the diamond tool 16 by the rotating grindstone 20, the pressure adjusting device retreats the piston 48 of the air cylinder 46 to cause the grinding head 1
8 can be adjusted to an air pressure that allows movement in the direction of separation. In place of using the air cylinder 46, an elastic spring such as a coil spring may be used as the pressing means of the grindstone head 18. However, in this case, since the pressure cannot be remotely controlled, a means for remotely controlling the pressure of the spring is required. It must be provided separately.

As shown in FIG. 1 and FIG.
On both sides of the upper surface of the air cylinder 46 that sandwich the air cylinder 46, the grinding wheel head 1 is pressed against the pressing force of the air cylinder 46.
A pair of sensors 50, 50 for detecting the movement of the grinding wheel head 18 and outputting a required signal when the diamond 8 moves away from the diamond tool 16 are provided. These sensors 50, 50 detect the movement of the grinding wheel head 18 in the separating direction and output a detection signal to a control unit (not shown), for example, to stop the tool grinding operation urgently, It functions to dress the rotary grindstone 20 by a dresser 52 described later. The sensor 50 may be any of a contact type such as a microswitch and a non-contact type using light, magnetism, and ultrasonic waves, as long as it can detect minute movement of the grindstone head 18. In the illustrated embodiment, two sensors 50 are used. However, this is because one of the sensors 50 is used for some reason.
This is because, even when the movement of No. 8 cannot be detected, the other sensor detects the movement and effectively prevents the malfunction of the tool grinder.

The illustrated diamond tool grinding machine 10 includes:
A dresser 52 for dressing the rotating grindstone 20 of the grindstone head 18 in a timely manner is provided. That is, the rotating whetstone 2
Since the grinding performance of the grinding surface of No. 0 decreases gradually as the diamond tool 16 is crushed or clogged by grinding, it is necessary to recover the grinding performance by dressing (re-dressing) at a required timing. The dresser 52 is suitably provided. The dresser 52 is basically a rotary grindstone. As shown in a circle A in FIG. 1 and a front view in FIG.
It is disposed so as to face the movement locus on the right side in the direction via the holding bracket 54, and is driven by a motor 56 with a speed reducer in a timely manner. That is, when receiving a dressing command from a control unit (not shown) during or after the grinding operation of the diamond tool 16, the grindstone head 18 moves to the position of the dresser 52 and rotates the grinding surface of the rotary grindstone 20 on the grindstone head 18. The necessary dressing is performed by contacting the inner dresser 52.

[0015]

Next, the operation of the diamond tool grinder according to the embodiment will be described. A diamond tool 16 is held in the tool holder 14, and each of the ground surfaces 16a is
Can be freely rotated and indexed. The servo motor 44
Is driven by the NC control to move the cutting table 34 in the Z direction toward the indexed surface 16 of the diamond tool 16 to be ground. At this time, the grindstone head 18 is constantly pressed to the left in the Z direction on the cutting table 34 under the urging action of the air cylinder 46, so that the home position is regulated.
The grindstone head 18 moves integrally with the cutting table 34. Then, when the rotary grindstone 20 of the grindstone head 18 is rotated by the motor 22, the rotary grindstone 20 comes into contact with the surface 16a to be ground of the diamond tool 16 in a standby state, thereby performing the cutting and grinding of the tool. In addition, a grinding fluid is poured into a grinding point as needed. At this time, in order to equalize the wear of the entire grinding surface of the rotary grindstone, the movable table 28 is reciprocally oscillated in the X direction at a required period.

A diamond tool 16 using a rotating grindstone 20
If the grinding wheel 20 is crushed or clogged while the grinding is in progress and the sharpness is reduced, the NC of the servo motor 44
Even if the cutting table 34 (and the grindstone head 18) is cut toward the tool 16 at a predetermined speed under the control, the grinding pressure corresponding to the cut amount cannot be removed, so that the grinding pressure acting between the two increases. . When the grinding pressure is increased in this manner, a force that pushes the grinding head 18 back in the separating direction acts as a reaction. This whetstone head 1
When the push-back force acting on the wheel 8 becomes more dominant than the pressing force applied by the air cylinder 46 to the grinding head 18, the grinding head 18 moves right above the cutting board 34 in the Z direction against the pressing force of the air cylinder 46. Slightly retracts (in FIG. 1). Therefore, since the rotating grindstone 20 during grinding does not grind the grinding surface 16a of the diamond tool 16 with a grinding pressure of a predetermined value or more, the grinding surface 16a may be chipped or the grinding wheel 20 may be damaged. The adverse effects that can occur can be reliably prevented. It should be noted that the pressing force of the air cylinder 46 selects an appropriate value within a range where the grinding pressure that increases during grinding does not become excessive, and can be easily adjusted by the pressure adjusting device as the predetermined value as described above. It is.

The above-mentioned grinding wheel head 18 is provided with a notch table 34.
The movement of the grinding wheel head 18 is extremely small, but by detecting the movement of the grinding wheel head 18 by the sensor 50, the operation of the tool grinder can be stopped immediately due to the deterioration of the grinding wheel grinding performance. The movement of the grinding head 18 exceeding a predetermined value (for example, 0.005 mm) is detected by the sensor 5.
When 0 is detected, the grinding operation is immediately stopped, and the grinding head 18 is moved away from the grinding surface 16a of the diamond tool 16 and automatically moved toward the dresser 52. Then, by performing the dressing by bringing the crushed or clogged grinding surface 20a of the rotary grindstone 20 into contact with the dresser 52, the reduced grinding performance can be recovered.

Since the sensor is used to detect the amount of movement of the grindstone head 18, there is an advantage that the manufacturing cost can be reduced and the amount of movement for instructing the timing of dressing can be easily set. Also, because the type and grade of the diamond tool 16 to be grounded are different,
When the area of the diamond sintered portion on the ground surface 16a increases or decreases, or when various factors such as the material of the tool, the type of the rotary grindstone 20 and other grinding conditions change, the grinding performance of the rotary grindstone 20 decreases. Even if you do not, whetstone head 1
The force for pushing the back 8 against the cutting board 34 increases or decreases. At this time, in order to adjust the unit grinding pressure, the pressure adjusting device described above is adjusted to increase or decrease the air pressure applied to the air cylinder 46 according to the area. The air cylinder 4
The adjustment of the air pressure in 6 may be performed steplessly by the pressure adjusting device according to the area, but may be performed in multiple steps within a range that does not cause inconvenience to the grinding pressure in order to simplify the operation. Good. That is, diamond tool 1
If the adjustment position is set in advance according to the range of the length of the cutting edge of No. 6, the operation becomes easy. In the illustrated embodiment, an example is shown in which the cutting table 34 (the grindstone head 18) is moved in the direction of approaching / separating from the tool 16 by NC control. 34
May be moved in the direction of approaching / separating from.

[0019]

As described above, according to the tool grinder according to the present invention, even when the grinding performance of the rotary grindstone is reduced when grinding an ultra-hard tool, the tool is chipped or rotated. There is an advantage that the tool can be ground in a good condition without damaging the grindstone itself. Also, when grinding an ultra-hard tool with a tool grinder, it is useful to detect that the grinding performance of the rotary grindstone has deteriorated and continue to move to a timely dressing for the grindstone to maintain good grinding performance. It also has an effect.

[Brief description of the drawings]

FIG. 1 is a schematic right side view showing a basic structure of a tool grinding machine according to a preferred embodiment of the present invention.

FIG. 2 is a schematic front view of a tool grinding machine according to a preferred embodiment.

FIG. 3 is a schematic plan view of a tool grinding machine according to a preferred embodiment.

[Explanation of symbols]

 12 Frame 14 Holder 16 Ultra Hard Tool (Diamond Tool) 16a Surface to be Grinded 18 Grinding Stone Head 20 Rotating Grinding Stone 34 Cutting Table 46 Pressing Means (Air Cylinder) 50 Sensor 52 Dresser

Claims (3)

[Claims] 1. A holder (14) for rotatably indexing a surface (16a) to be ground of a tool (16), and a surface (16a) to be ground of the tool (16) held by the holder (14). A tool grinding machine provided with a grinding wheel head (18) for cutting and grinding a tool (16), which is disposed on a frame (12) so as to be movable close to and away from the tool (16) held by the holder (14), A notch table (34) to which the proximity / separation movement is given by control; and the grindstone head installed on the notch table (34) and capable of moving close to and away from the tool (16) held by the holder (14). (18), a pressing means (46) disposed on the cutting table (34), for pressing and controlling the whetstone head (18) to a position close to the tool (16) held at all times by the holder (14). The tool (16) by a rotating grindstone (20) of the grindstone head (18)
When a grinding pressure exceeding a predetermined value acts on the rotary grindstone (20) during grinding, the pressing means (46) of the pressing means (46) is moved so that the grindstone head (18) can be moved in the separating direction under the reaction of the grinding pressure. A tool grinding machine characterized in that the pressing force is adjustable. 2. A holder (14) for rotatably holding a surface (16a) to be ground of a tool (16), and a surface (16a) to be ground of the tool (16) held by the holder (14). A grinding wheel head (18) that cuts and grinds the grinding wheel, and a rotary grinding wheel (2
A tool grinder provided with a dresser (52) for dressing (0), a tool (16) held on the holder (14), the tool (16) is disposed on a frame (12) so as to be movable close to and away from the tool (16), A notch table (34) to which the proximity / separation movement is given by control; and the grindstone head installed on the notch table (34) and capable of moving close to and away from the tool (16) held by the holder (14). (18), a pressing means (46) disposed on the cutting table (34), for pressing and controlling the whetstone head (18) to a position close to the tool (16) held at all times by the holder (14). And, against the pressing force of the pressing means (46), the grinding head (18)
When moved in the direction away from the tool (16), comprises a sensor (50) that detects the movement and outputs a signal, during the grinding of the tool (16) by the rotating grindstone (20) When a grinding pressure exceeding a predetermined value acts on the rotating grindstone (20), the pressing force of the pressing means (46) is adjusted so that the grindstone head (18) can be moved in the separating direction under the reaction of the grinding pressure. Movement of the grinding wheel head (18) in the direction away from the sensor (5).
0), and the tool grinder is configured to dress the rotary grindstone (20) by the dresser (52). 3. The tool grinding machine according to claim 1, wherein the pressing force of the pressing means is air pressure, and the air pressure is adjustable to adjust the grinding pressure.