JP3270115B2 - Blade position detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting a relative positional relationship between a spindle for gripping a workpiece and a cutting edge of a tool for processing the workpiece in a machine tool.

[0002]

2. Description of the Related Art Measures are taken to measure the deviation of the relative position between a workpiece and a tool tip caused by wear of a tool or a change over time of a machine, and to correct a command value of a movement amount of a tool post by the deviation. A device for automatically correcting the processing dimensions is known, for example, from Japanese Patent Application Laid-Open No. 55-106704. In such an apparatus, it is necessary to accurately detect the relative positional relationship between the spindle that grips the workpiece and the cutting edge of the tool mounted on the tool rest, and for that purpose, a detection sensor such as a contact sensor or a proximity switch is used. .

In a conventional apparatus, these detection sensors are mounted on the tip of an arm which is mounted on a headstock, and swing the arm from the headstock side to a work processing area by a rack and pinion mechanism or a swing motor during measurement. The structure is such that the detection sensor is lowered and advanced into the movement area of the tool edge.
The turning direction of the detection sensor when the arm swings is a direction intersecting with the plane of relative movement of the tool rest with respect to the main spindle, and the detection sensor is retracted above or obliquely above the head stock during work processing.

When detecting the position of the tool edge, the arm is rotated downward until it comes into contact with the stopper, the detection sensor is advanced into the plane of relative movement of the tool edge, and the tool edge is placed on the measurement surface of the detection head. When the contact is made, the micro switch incorporated in the detection sensor is operated, and the relative position of the tool post with respect to the spindle at the time when the output signal of the detection sensor is detected is read. Is corrected.

[0005] For example, a lathe requires four measuring surfaces in contact with the cutting edge of a tool in a form corresponding to the respective cutting tools for outer diameter machining, inner diameter machining, and left and right end face machining. In the apparatus, a microswitch is provided on each of the four measurement surfaces.

[0006]

In the conventional apparatus, the arm supporting the detection sensor becomes large, and the arm rotates approximately 90 degrees when the detection sensor is moved forward and backward. A strong stopper was also required for positioning the arm at the detection position. In addition, a large space is required for swinging the arm, and the arm projects above the headstock even in the retracted position.Therefore, the cover that covers the machine must be enlarged, or the operator approaches the machine. There were problems such as worsening.

In view of the demand for a compact machine tool having a high machining efficiency, the present invention can make the entire apparatus more compact, and the inertia mass of the moving or swinging member when moving forward and backward is small. An object of the present invention is to obtain a blade edge detecting device having a simpler structure that can operate at a higher speed.

[0008]

According to the apparatus of the present invention, a rail 31 parallel to the axial direction of the main spindle is fixed to a base plate 11 supporting a headstock 13, and a slide base slidable along the rail 31. 36 and its reciprocating drive 32 are provided. The slide table 36 is provided with an arm 43 extending toward the work area of the work, and a detection sensor 45 is attached to a tip of the arm 43.

Further, in the device of the present invention, the cam follower
Detected by the guide means 33 using 44 and links
The arm 43 is moved at the stroke end when the sensor 45 advances.
It swings to the headstock 13 side, and the detection sensor 45
The blade is advanced into the moving area. That is, arm 4
3 is moved to the slide base 36 relative to the tool post 5 relative to the spindle 2.
It is mounted swingably around an axis 42 perpendicular to the moving plane,
Along with the movement of the slide table 36 along the
The shaft 4 in a plane parallel to the plane of relative movement of the cutting edge.
Guide means 33 for swinging the headstock 13 around
Provide.

In the device having the above-described configuration, the detection sensor 45 is mainly
The blade moves forward and backward by linear motion in a direction almost parallel to axis 2.
It advances to the detection position and retreats to the side of the headstock 13.

The positioning of the detection sensor 45 at the time of measurement is performed by a stopper that regulates the movement stroke end of the slide table 36 and the guide end of the guide means 33.

[0012]

When detecting the position of the cutting edge, the slide base 36 is advanced to the processing area side, and the cutting edge of the tool 51 mounted on the tool base 5 is brought into contact with or close to the detection sensor 45 at the tip end of the arm 43 so that the main spindle 2 and the tool can be moved. The position of the relation with the cutting edge is detected.

In the apparatus according to the present invention, the movement of the arm 43 when the detection sensor 45 is moved forward and backward is performed in a direction substantially parallel to the extending direction of the arm 43. It can be very small in comparison. In addition, since the inertial force in the bending direction applied to the arm 43 when the detection sensor advances and retreats is small, the size and weight of the arm 43 can be reduced, and the inertial load can be further reduced. The positioning mechanism and the like for the detection sensor 33 and the detection sensor 45 have a small and simple structure, which not only contributes to downsizing of the entire apparatus, but also increases the operating speed of the apparatus. In addition, since the operation space of the arm 43 when the detection sensor advances and retreats is small, it is possible to take a sufficient advance and retreat stroke, and it is possible to easily set the standby position of the detection sensor to a position fully separated from the processing area. It is possible to prevent breakage of the device and a decrease in measurement accuracy due to the attachment of chips and cutting oil to the sensor 45.

[0014]

Next, a description will be given of an embodiment in which a lathe is provided with a blade position detecting device according to the present invention. A headstock 13 that supports the spindle 2 provided with a chuck 21 for gripping a work is fixed to a bed 1 of the lathe via a base plate 11 and a gantry 12 that are movable or fixed in the spindle direction. The main shaft 2 includes a V-belt pulley 22 and is driven by a main shaft motor (not shown) via a V-belt (not shown). Pulley 22
Chuck cylinder 2 that opens and closes chuck 21 behind
3 is attached.

A second gantry 14 is fixed on the base plate 11 adjacent to the gantry 12, and a rail 31 and a hydraulic cylinder 32 in a direction parallel to the main shaft 2 are fixed to the second gantry. A cam plate 33 is fixed above the cylinder 32. The cam plate 33 has a cam groove 3 extending in parallel with the main shaft 2 and having a distal end bent toward the chuck 21.
4 are formed.

The rail 31 is provided with a slide base 36 provided with a shoe 35 which fits and slides without any gap, and a bracket 37 extending from the slide base is fixed to a drive block 38 of the cylinder 32. I have. A bearing 41 is mounted on the slide base 36 in a direction perpendicular to the plane of relative movement of the tool rest 5 with respect to the main shaft 2. A fulcrum pin 42 is fitted into the inner ring of the bearing 41, and extends parallel to the main shaft 2 to the fulcrum pin 42, and the tip thereof is attached to the chuck 2.
The base end of the arm 43 bent inward so as to be positioned in front of the arm 1 is fixed.

A cam follower 44 that rotates about an axis parallel to the fulcrum pin 42 is mounted on the arm 43, and the cam follower 44 is rotatably fitted in the cam groove 34 described above. A detection sensor 45 is fixed to the tip of the arm 43 at a height such that its measurement surface 46 is located within the plane of movement of the cutting edge of the tool 51 mounted on the tool rest 5.

A detection sensor 45 is provided with a shaft 48 rotatable about an axis parallel to the fulcrum pin 42 on a housing 47 fixed to the arm 43, and has four measuring points at its upper end, each having a different direction of the surface by 90 degrees. With a surface 46,
Each measurement surface 46 is provided at a position deviated from the axis of the shaft 48 within the moving surface of the tool edge, and when the measurement surface 46 is pushed by the edge of the tool 51, the shaft 48
When any one of the measurement surfaces 46 is pushed, the measurement surface 46 rotates in the same direction. The shaft 48 is urged by a spring in a direction opposite to the rotation direction, and is locked at a predetermined position by a stopper. The rotation of the shaft 48 when the tool 51 comes into contact is detected by one micro switch provided in the housing 47.

Next, the operation of the apparatus of the above embodiment will be described. In the steady state including the work processing state, the slide table 36 is in the retracted position (the right side in FIG. 3) by the cylinder 32, and at this time, the cam follower 44 provided on the arm 43 is in a straight portion on the base end side of the cam groove 34. positioned. In this state, the arm 43 is at a position retracted to the side of the headstock 13 by the retreating operation of the slide base 36, and further, the arm 43 swings outward due to the cam follower 44 being guided by the linear portion of the cam groove 34. And the detection sensor 45 at the tip of the arm 43 is retracted to the side of the chuck 21.

When the slide base 36 is advanced from the retracted state by the cylinder 32, the cam follower 44
Is guided by the linear portion of the cam groove 34, and the arm 43 moves in parallel. However, when the cam follower 44 approaches the bent portion of the cam groove 34, the arm 43 moves to the headstock side as the arm 43 advances. In the state shown in FIG. 1 in which the swing starts and the slide table 36 reaches the stroke end on the advance side, the arm 43 rotates approximately 45 degrees, and the detection sensor 45 at the tip thereof is positioned in front of the chuck 21.

In this state, the tool rest 5 is relatively moved with respect to the main shaft 2, and the cutting edge of the tool 51 mounted thereon is brought into contact with any one of the measurement surfaces 46 of the detection sensor 45. This contact rotates the shaft 48 of the detection sensor,
A detection signal is output from the limit switch. This detection signal is sent to the controller, and the controller measures the relative positional relationship of the tool rest 5 with respect to the main shaft 2 at this time. Then, a difference between the measured value and a preset reference value is calculated and stored as a correction value.

The detection sensor 45 has four measuring surfaces so that the cutting edges of four types of tools for outer diameter cutting, inner diameter cutting, and left and right end face cutting contact the arms 43 at right angles.
Is selected at the tip of the tool, and a measurement surface to which the tip abuts is selected according to the type of tool. With the detection sensor having this structure, the same detection signal is obtained regardless of the type of tool, regardless of which measurement surface is pressed.

When the detection of the cutting edge position is completed, the tool 51 is separated from the detection sensor 45, and the slide base 36 is moved backward by the cylinder 32. By this retreating operation, the arm 43 is retracted so as to be drawn into the side of the headstock 13, and the cam follower 44 is guided along the cam groove 34, the arm 43 swings outward, and the detection sensor 45 is chucked. Retreat to the side of 21.

[0024]

According to the blade position detecting device of the present invention, a large arm for supporting the detecting sensor and moving it forward and backward is not required, the driving device for the arm can be made small and inexpensive. Etc. are reduced. In addition, since the arm can be made smaller and the arm moves in a linear direction, the inertial mass when the arm moves forward and backward is small, and the inertial load when positioning at the cutting edge position detection point is small, so that the stopper and the positioning mechanism are simple. It will be of a structure. Also, since the standby position of the detection sensor can be easily set to a position away from the machining area of the machine, it is possible to prevent breakage of the device due to chips, cutting oil, etc., and decrease in measurement accuracy. There is an effect that the operation space can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view showing a cutting edge detection state.

FIG. 2 is a front view

FIG. 3 is a plan view showing a sensor retreat state;

[Explanation of symbols]

 2 Spindle 5 Turret 11 Base plate 13 Spindle 31 Rail 32 Hydraulic cylinder 34 Cam groove 36 Slide base 42 Support pin 43 Arm 45 Detection sensor 51 Tool

Claims (1)

(57) [Claims] A rail (31) parallel to the axial direction of a spindle is fixed to a base plate (11) supporting a headstock (13).
An arm (43) extending toward the workpiece processing area is provided on a slide table (36) slidable along 1), and the arm (43) is
The relative movement of the tool post (5) with respect to the spindle (2) on the slide base (36)
It is mounted swingably around the axis (42) perpendicular to the plane,
With the movement of the slide base (36) along the rail (31)
The arm (43) in a plane parallel to the relative movement plane.
Guide means (3) for swinging around the shaft (42) toward the headstock (13)
A detection sensor (4 ) is provided at the tip of the arm (43).
5) is mounted, a reciprocating drive (32) for moving the slide table (36) along the rail (31) is provided, and the slide table (36) is provided.
Tool mounted on the tool post with the tool advanced to the machining area
A machine tool characterized by detecting the relative position between the main shaft (2) and the cutting edge of the tool by bringing the cutting edge of (51) into contact with or near the detection sensor (45) at the tip of the arm (43). Cutting edge detection device.