JPS632278Y2 - - Google Patents

Description

[Detailed description of the invention] This invention detects the position of the cutting edge of a tool attached to the tool rest by using a sensor that converts two-dimensional displacement into unidirectional displacement. The present invention relates to a blade edge detection device that detects the correct blade edge position by compensating for the

Conventional tool edge detection devices mounted on tool rests are often applied to specific tools, making it difficult to support a variety of tools. Also, JP-A-55-
No. 106704 is equipped with a detection head that is installed on the spindle stock and rotates between the detection position and the retracted position on the front of the chuck, and the tool contacts the cutting edge of the tool post to detect the cutting edge position, and detects the difference from the preset normal position. It is shown that errors caused by the wear allowance of the cutter and thermal displacement of the machine body and ball screw can be simultaneously corrected by reading the information using an automatic correction device. However, in this device, the base of the detection arm is mounted on the main spindle of the headstock, so it is necessary to compensate for errors caused by thermal displacement of the ball screw of the NC lathe and the machine body, etc. No consideration has been given to compensation for thermal displacement, and there has yet to be a system that adequately compensates for thermal displacement.

This invention aims to provide a device that is easy to handle and can be easily applied to various tools, and can detect the correct position of the cutting edge by compensating for the displacement of the detection device due to heat. In a machine, a touch sensor that can detect when the tool tip comes into contact with the tool from two directions, the X-axis and the Z-axis, generates a signal when the tool comes in contact with the tool, and at the time of detection, it is supported so that it advances to a position where it comes into contact with the tool tip of the tool post. A reference block gauge is installed near the tool on the head and tool rest, and initial values for the tool cutting edge and block gauge are set.When detecting the tool cutting edge, the thermal displacement of the measurement head is measured using the reference block gauge. It is characterized by being able to detect the correct compensated tool cutting edge.

Embodiments of the present invention will be described below based on the drawings. A bracket 4 is fastened to the upper side of the spindle head 3 of a lathe with an NC device, which rotatably supports a spindle 2 having a chuck 1 fixed to the tip thereof. A small shaft 5 having a pinion 6 carved in the center thereof is vertically supported on the bracket 4 so as to be rotatable by a bearing 7, and swing arms 8 are fixed to both ends of the small shaft 5. The swing arm 8 is provided with an elbow portion 9 that projects from the front of the chuck 1, a touch sensor 10 is provided parallel to the spindle axis at a position displaced from the spindle axis, and a workpiece presence/absence detector 11 is provided on the spindle axis. It is being The pinion 6 of the small shaft 5 is connected to a hydraulic cylinder 12 which is installed horizontally on the bracket 4.
The swing arm 8 is engaged with a rack 14 carved into a piston rod 13 which is driven by the operation of the chuck, and is rotated by the pressure fluid supplied to the hydraulic cylinder 12, so that the swing arm 8 is moved to a chuck front position and a side retracted position.
Rotated 90°. The workpiece presence/absence detector 11 is a reflection type detector consisting of a light emitter and light receiver using a phototransistor or the like, and the light emitting/receiving window is arranged in a direction perpendicular to the workpiece when the rotating arm 8 rotates 45 degrees. is directed towards. When the rotating arm 8 receives reflected light at around 45 degrees during the rotation, a signal is sent to the control device, the pressure fluid supply path of the cylinder 12 is switched, and the cylinder 12 is returned to the inverted and retracted position. Note that the sensing means of the detector is not limited, and a highly sensitive non-contact sensor can also be used.

Next, the touch sensor 10 has a stepped through hole 102 formed in the center of the main body 101, and a feeler 1 at the top of the stepped through hole 102.
Two pivots 104 with 03 arranged perpendicular to the axis
Supported by Therefore, due to the nature of the pivot bearing, the feeler 103 can rotate about the pivot without any clearance. The top of the feeler 103 is formed into a T-shape with arms 105 having hook-shaped ends 105a and 105b protruding from both sides within the rotatable surface, and a conical concave surface 106 is provided at the inner end. A transmission shaft 108 having the same conical concave surface 107 on the top facing the conical concave surface and on the same axis as the feeler 103 is slidably fitted into the through hole 102 to minimize the adverse effects caused by the sliding gap. Therefore, it is supported at two positions with a long interval compared to the shaft diameter. A highly spherical sphere 109 is interposed between both conical concave surfaces 106 and 107.
On the other hand, the other end of the transmission shaft 108 is formed into a flat surface and faces a sensing switch 111, which will be described later, and is equipped with a safety ring 110 to protect the sensing switch when the shaft moves too much. The sensing switch 111 is prevented from rotating by the sensor body 101, and is fixed at the center of a slider 112 whose forward end is restricted. This slider is constantly pressed toward the feeler by a spring 114 interposed between it and a lid 113 fastened to the rear of the sensor body. The transmission shaft 108 is biased by a spring 116 interposed between a flange 115 fitted to the rear end and the slider 112 so that there is no gap between the conical concave surfaces that sandwich the sphere 109. . Furthermore, the lid body 1
13 supports a pin 117 that is in contact with the rear end of the slider 112, and when the slider is pushed back by the transmission shaft, a safety limit switch 118 is operated to move the tool rest or the machine back or stop. There is. Furthermore, a dustproof seal 119 is provided at the opening around the feeler section to protect the sliding section within the touch sensor body from dust. The explanation is that there are hook shapes 105a and 105 on both ends of the filler.
b is provided, but there are cases where a hook shape is provided only on one end. In addition, in order to cope with the case where the tool rest has two positions, an upper tool rest and a lower tool rest, it is of course more efficient to provide two corresponding touch sensors. On the other hand, a plurality of various tools 16a to 16g are provided on the turret tool rest 15 of the lathe with NC device, and a reference block gauge 17 is provided near each tool so as to be able to come into contact with the hook shape 105a or 105b of the feeler 105. It is being The block gauges are mounted so that their respective reference surfaces face in the direction in which the cutting edges of the tools 16a to 16g make hook-shaped contact, and serve as a reference for the tools in the contact direction, that is, the Z-axis direction or the X-axis direction. It is preferable that this reference block gauge is provided corresponding to each tool, but if the reference plane direction is the same, it is not necessarily necessary to provide it correspondingly to each tool, and it is possible to use it for the same purpose. However, a touch sensor or an indicator that generates a signal can also be used.

This device formed in this manner detects the position of the cutting edge in combination with the current position detection mechanism of the tool rest of the NC device (not shown), and inputs this position to the NC device to correct the cutting edge position.

Next, we will discuss the effect. Prior to gripping the workpiece, the initial values of the reference block gauge and tool are first set in the NC device according to instructions from the NC device.
That is, the pivoting arm 8, which has been retracted to a side position of the chuck 1, is supplied with pressure fluid to the hydraulic cylinder 12, so that the piston rod 13 moves forward, and the small shaft 5 is pivoted via the rack and pinion. At this time, light is projected from the window of the workpiece presence/absence detector 11, but since the workpiece has not yet been gripped, there is no reflected light and the detector does not output a signal. Elbow part 9 on the front of 1
to advance. On the other hand, it is assumed that the tool 16b of the turret tool post is selected and indexed according to the workpiece, and the tool post is moved in the direction of the spindle axis (Z-axis direction) and the cutting direction (X-axis direction). 17 is brought into contact with the hook shape 105a of the feeler 103 from the X-axis direction. The feeler 103 is rotated about the pivot 104 by the contact of the cutting edge, and the ball 109 restrained by the conical concave surface 107 of the transmission shaft 108 is pushed out in the axial direction by the conical concave surface 6 of the filler, and the sensing switch is activated by moving the transmission shaft 108. 111 to generate a signal. Based on this signal, the absolute position of the tool rest 15 in the X-axis direction is detected and set as the initial value Ax ₁ of the reference block gauge 17. Next, the cutting edge of the selected tool 16b is shaped like a hook 10.
5a from the X-axis direction and the sensing switch 111
act to emit a signal. Based on this signal, the absolute position of the tool rest 15 in the X-axis direction is detected and set as the initial value Bx ₁ of the tool 16b. Both initial values are set in the NC device. When the initial value is set in this manner, the pressure fluid to the hydraulic cylinder 12 is switched, the piston rod 13 is moved backward, the small shaft 5 is reversed, and the swing arm 8 is returned to the retracted position. The workpiece is then conveyed and gripped, and predetermined processing begins according to instructions from the NC device. When the set number of pieces have been machined, pressurized fluid is supplied to the cylinder 12 in response to a tool wear check command, and the swing arm 8 is turned again toward the front of the chuck 1. At this time, light is projected from the window of the workpiece presence/absence detector 11, and near the 45° rotation of the rotating arm 8, if there is a workpiece, the light is reflected by the surface of the workpiece and is received by the detector, which receives the signal and controls the NC device. In response to a command, the supply of pressure fluid to the fluid pressure cylinder 12 is switched and the swing arm 8 is suddenly reversed and retracted to carry out the workpiece. If there is no workpiece, there will be no reflected light, and the chuck is rotated by a predetermined amount of 90 degrees, and the elbow portion 9 is advanced to the front of the chuck 1. Therefore, the tool rest 15 is moved in the Z-axis and The current position of the tool post 15 at the time of the change is input and stored in the NC device as the current value Ax ₂ . Next, the NC device sets the current position of the tool rest 15 at the time when the cutting edge of the tool 16 in use contacts the hook shape 105a from the X-axis direction (Fig. 5) and a signal is issued from the detection switch 111 as the current value Bx ₂ . input and memorize it. In the NC device, the previous initial value Ax ₁ ,
Based on Bx ₁ and current values Ax ₂ and Bx ₂ (Bx ₁ −
The calculation of Bx ₂ )-(Ax ₁ -Ax ₂ ) is performed, and the subtracted value is obtained as the amount of tool wear after removing thermal displacement, and this value is used as a correction value to correct the X-axis position of the tool rest.
Once the correction is completed, the tool can be used again up to its usage limit. When the drill 16e is used to drill a hole in the workpiece, the surface of the reference block gauge is oriented in the Z-axis direction, and a correction value in the Z-axis direction is determined.

As explained in detail above, the present invention is structured so that the displacement of the measurement head equipped with a touch sensor due to external conditions or heat generation due to continuous operation can be removed from the measured value of the cutting edge position, making it possible to accurately determine the amount of tool wear. It is what is required. Therefore, there is a great effect that high product accuracy can be maintained even during long-term unmanned operation.

[Brief explanation of drawings]

FIG. 1 is a side view of the blade edge detection device at the detection position.
Figure 2 is a vertical cross-sectional view of the touch sensor, Figure 3 is a diagram showing the relative positions of the feeler and tool during detection, Figure 4 is a diagram of the detection state by the reference block gauge during intermediate machining, and Figure 5 is during intermediate machining. It is a detection state diagram of the tool. 8...Swivel arm, 10...Touch sensor, 12...
...Fluid pressure cylinder, 15...Turret turret, 1
6a to 16g...Tool, 17...Reference block gauge, 103...Feeler, 105a, 105b
...hook shape.

Claims (1)

[Scope of utility model registration request] In a machine tool with an NC device, there is a touch sensor that has a feeler that detects displacement when a tool tip contacts the head from two directions, the X-axis and Z-axis directions, and generates a signal when the tool comes in contact with the head, and a touch sensor that emits a signal when the tool comes in contact with the tool head from two directions, the X-axis and Z-axis directions. A rotating arm is provided so that a detection plane containing the turret becomes a movement plane of the tool post at the detection position, and is rotatably provided between a detection position on the front side of the chuck and a retracted position on the side of the chuck, and the rotating arm is moved to the two positions. A measurement head comprising a rotation drive device controlled by a command for rotation, a reference block gauge with a reference surface facing the position detection direction of the cutting edge provided on a tool post having a tool, and a measurement head formed by the touch sensor. The change value determined by the difference between the initial value of the tool cutting edge position and the measured value of the tool cutting edge position detected after that is determined by the difference between the initial value of the reference block gauge and the measured value of the reference block gauge detected after that. and calculation means for compensating for a certain amount of thermal displacement,
A measurement head displacement compensation type cutting edge detection device characterized by determining the true amount of tool wear that does not include the amount of thermal displacement.