JPS6042051Y2 - tool positioning device - Google Patents

Description

[Detailed description of the invention] The accuracy of the tool positioning operation directly affects the accuracy of the manufactured workpiece, so the tool must be correctly positioned on the machine tool.

This is especially true in the case of numerically controlled (NC) machine tools where the tool must be correctly positioned within an X, y, z coordinate system.

To this end, tool positioning devices have traditionally been used, which must be pivoted into the machining area.

The reason for this is to avoid exposing the tool positioning device to the risk of coming into contact with chips or dirt from the coolant in the machining area.

In addition to these risks, conventional devices have many other drawbacks, including:

That is, optical single tool positioners with a light barrier scanning the tool cutting edge become fouled relatively quickly, and pneumatic single tool positioners that use an air stream instead of a light stream are relatively inaccurate.

Furthermore, tool positioning devices with contacts that are brought into contact with the tool under low voltage cannot guarantee the necessary contact reliability over long periods of time, and furthermore, tool positioning devices based on inductive principles are particularly sensitive to chips. It is necessary to compensate for the balance electrically.

The purpose of the present invention is to provide a durable tool positioning device for a machine tool that can withstand the adverse environmental conditions typical of machine tools, and guarantees highly accurate and safe operation.

According to the present invention, there is provided a device for positioning a tool in a machine tool, in which a first housing having the same type as a known housing for a single limit switch is provided with a push rod guided by a guide device, and the push rod is guided by a guide device. A rod projects from the first housing and is adapted to abut the tool to be positioned, and a flexible sealing diaphragm is sealingly mounted on the first housing and the push rod, and a flexible sealing diaphragm is sealingly mounted on the first housing and the push rod. A second housing enclosing the rod guide and further formed from a cavity accommodates a known linear measurement probe movable by a push rod, said second housing being fixed to said first housing and connecting said first and second housings. A tool positioning device is provided, characterized in that a sealing member is inserted between the two housings.

When actually used for many years, German Industrial Standard 436
It has been found that a housing for a single limit switch with dimensions according to 93 is a particularly good storage device.

The tool positioning device according to the invention can also withstand particularly adverse environmental conditions in the machining area of a machine tool without endangering its functionality.

The part of the tool positioning device that generates the measurement signal is hermetically sealed so that accuracy is not adversely affected.

For this purpose, highly precise linear measuring probes are used which are based on optical measuring principles.

In a preferred embodiment of the invention, the linear measuring probe comprises a glass measuring scale, the scale being displaceable by a push rod in the direction of displacement of the push rod, and a photoelectric pulse scanning the glass measuring scale. Equipped with a generator.

By measuring the generated pulses, the push rod-shaped path can be detected with accuracy within the micron range.

However, it is also possible to use other linear measuring probes, for example linear potentiometers, dielectric layer path length recorders, linear measuring probes based on other measuring principles.

Although housings for single limit switches as described above have been known for a long time, they have traditionally only been used to house switches with on/off characteristics.

However, it has not been used to accommodate linear measurement devices that generate continuously or stepwise varying analog or digital signals.

A large number of attempts based on various principles have been made to solve the problems that have existed for a long time, but all have been unsatisfactory in the case of practical applications.

However, the present invention completely solves these problems for the first time.

The known limit switch has a two-part push rod.

Parts located inside the housing can be placed against the force of the spring and pushed into the other parts by the puppy.

In order to perform accurate linear measurements, the push rod of the device according to the invention has a rigid form, i.e. there is no play or elastic transducer between the part that abuts the tool and the part that generates the measurement signal. is not provided.

In addition, a stop member is arranged in the first housing such that a shoulder provided on the push rod limits the path of the push rod to prevent damage to the linear measuring probe due to too strong actuation of the push rod. has been done.

Hereinafter, the present invention will be explained by way of examples with reference to the accompanying drawings.

In FIG. 1, a first housing 10 is shown, which is preferably used as the upper part of a housing containing a single limit switch according to German Industrial Standard 43493.

However, in principle, housings that deviate from this German industrial standard can of course also be used.

A stepped bore 12 is formed in the first housing 10, and a so-called maintenance-free dry sleeve 1 is provided on the outer side of the bore.
4 has been inserted.

The maintenance-free dry sleeve 14 has the function of guiding a rigid push rod 16.

In the rest position, the rod 16 rests with its collar 16a against the step of the bore 12, and the rod 16 has a reduced diameter portion 1 in its lower region in which an annular groove 16 is formed.
6b.

Furthermore, since the first housing 10 is formed with a number of bores 18, it is possible to assemble the housing on a mechanical component.

A threaded bore 20 is formed in the first housing side into which a so-called threaded conduit fitting 22 is screwed.

The threaded conduit fitting 22 is threaded from a threaded sleeve 22a, an annular sealing member 22b, and a threaded plug 22c, such that tightening the plug 22c closes the annular sealing member 22b. The size of the through hole therein is reduced by being pressed.

A stop disc 26 is disposed within the stepped bore 12 of the first housing 10 and is secured to the bore 12 by an upwardly curved flange 28.

The stop disk 26 limits the path by which the push rod 16 is pushed into the first housing 10, but this is due to the shoulder 1 of the push rod that defines the upper portion of the rod lower portion 16b.
6d comes into contact with the stopping disk 26 and comes to rest.

Flexible diaphragm from rubber or plastic 3
0 is secured within the first housing 10 by a safety ring 32 and an upwardly bent flange 34.

The diaphragm 30 surrounds the push rod 16 in the area of its annular groove 16c so that the stepped bore 12 is completely sealed by the diaphragm 30.

Therefore, something like cutting oil that enters the inside of the housing through the sliding guide device of the push rod 16 is caused by the diaphragm 3.
It is not possible to approach the interior of the housing below 0.

Instead of the flat housing cover of the single limit switch housing according to German Industrial Standard 43693, the tool positioning device according to the invention has a second crucible-shaped or box-shaped housing 40.

The second housing 40 has the following characteristics with respect to the first housing 10:
They are fixed in a certain way (not shown), and a rectangular sealing member is inserted between both housings.

A linear measurement probe 44 consisting of a housing 46 is housed within the second housing 40 .

A glass measurement scale, which will be described later, is accommodated in the probe housing 46 together with a cooperating light barrier, and a shaft 48 is fixedly attached to the housing 46.

The shaft 48 has a bore (not shown) in the longitudinal direction, and a probe pin 50 is slidably guided within the bore.

As the probe pin 5o is pushed downward by the push rod 16 against the force of the restoring spring 52, the glass measurement scale moves in the longitudinal direction as will be described later.

The measurement probe 44 is held within the second housing by a clamping member 54.

The tightening member 54 surrounds the shaft 48 and the screw 56
is mounted on the mounting surface 58 of the second housing 40 by the mounting surface 58 of the second housing 40 .

Furthermore, the cable 60 connects to the housing 46 of the measurement probe 44.
The cable 60 extends outwardly from the housing 10.40 in a gas-tight manner by means of a threaded conduit fitting 22.
being led outside.

A glass measuring scale 70, partially illustrated in FIG. 2, is housed within the probe housing 46.

The measurement scale 70 is fixed in a fastener 50a attached to the end of the probe pin 50, and the scale 70 includes a light source 72, a capacitor 74, a light shield 76 having a long hole, and a photodetector. Pass through the light barrier that warns from 78.

When the measurement scale 70 is displaced in the longitudinal direction, the photodetector 78 generates a rectangular pulse.

This rectangular pulse is passed through the cable 60 to the meter 8.
Sent to 2.

The meter 82 measures the forward and backward path lengths of the push rod 16 and can, if desired, reproduce the measurements with an indicator comprising a light emitting diode.

In the case of a numerical control (NC) machine tool, the measurement contents of the meter 82 are transmitted to the encoder 86.

The encoder 86 converts the content measured by the meter into a BCD code and transmits it to the machine tool control device.

Meter 82 receives input 82a, which causes meter 8
2 can be set to zero.

At any point along the path of probe pin 50, this manual force 82a allows meter 82 to be set to zero by an external signal or switch.

As is clear from the above, the operation of the device for generating the measurement signal takes place without play.

This is because the use of a transmission lever or the like is avoided, and there is no play in changing the path from the push rod to the glass measuring scale.

[Brief explanation of the drawing]

FIG. 1 is a partial side sectional view showing a tool positioning device according to the present invention, and FIG. 2 is an illustrative view of a portion that generates a measurement signal. 10...First housing, 14...Guide device, 16...Push rod, 30...
- Flexible sealing diaphragm, 40... Second housing, 42... Housing sealing member, 44.
...Linear measurement probe.

Claims (5)

[Scope of utility model registration request] (1) A device for positioning a tool within a machine tool,
A first housing 10, which is of the same type as the known single limit switch housing, is provided with a push rod 16 guided by a guide device 14, which protrudes from the first housing 10 and is adapted to engage the tool to be positioned. a flexible sealing diaphragm 3 adapted to be in contact with the
0 is sealingly mounted on the first housing 10 and the push rod 16 to seal off the push rod guide 14, and a second housing 40 formed from a cavity is provided with a conventional linear housing movable by the push rod 16. Measuring probe 44
, wherein the second housing 40 is fixed to the first bousing 10 and a sealing member 42 is inserted between the first and second bousings. (2) The linear measurement probe 44 is equipped with a glass measurement scale 70, the scale 70 can be displaced by the push rod 16 in the displacement direction of the push rod, and the probe 44 scans the glass measurement scale 70. A tool positioning device according to claim 1, which comprises photoelectric pulse generators 72 to 78. (3) The cable 60 of the linear measurement probe 44 is the first
3. A tool positioning device according to claim 1, which extends through a threaded conduit fitting 22 on the housing 10. (4) The tool positioning device according to any one of claims 1 to 3, wherein the second housing has a box shape. (5) the push rod 16 has a rigid form;
The shoulder portion 16d provided on the push rod 16
The stopping member 26 is disposed within the first housing 10 so as to limit the path of the utility model registration claim 1.
The tool positioning device according to any one of items 1 to 4.