DE10207415B4 - Hydraulic or pneumatic drive for a tool clamp - Google Patents

Abstract

Hydraulic or pneumatic drive (10) for a tool clamp with a clamping device (1), characterized in that a piston (14) serving for the drive is provided with an axial piston extension (21), in which at least one radial recess (31) for receiving There is at least one locking element (22) which is mounted so as to be radially movable in this at least one radial recess (31), the at least one locking element (22) having a locking body (23) movable in the axial direction under the load of a spring (29). cooperates and a positive locking between the at least one locking element (22) and the locking body (23) is given.

Description

The invention relates to a hydraulic or pneumatic drive for a tool clamp according to the preamble of patent claim 1.

A hydromechanical device is, for example, with the subject of EP 780 180 B1 known.

However, the cited document deals essentially only with the mechanical part of the clamping device, which consists essentially of mutually movable collets, between which the clamping cone is picked up and tensioned.

However, this publication also discloses a hydromechanical drive for the collet in such a way that by means of pressure oil, a hydraulic piston is moved, which is connected via a corresponding connection in the manner of a tie rod with the mechanical clamping elements.

There is another group of actuators known for tool clamps that clamp with spring force.

A feature of the different groups of grips is that when the pressure oil supply is eliminated, the tensioner must not open unintentionally.

For this purpose, the arrangement according to the EP 780 180 B1 a locking of the drive piston of the hydraulic circuit in such a way that a locking element runs on an inclined ramp surface and the piston is locked with it.

However, the arrangement of obliquely inclined ramp surfaces in the axial direction has the disadvantage that the locking effect is not secure enough. For example, when mechanical impacts occur, unintentional release of this mechanical interlock can occur. The Selbsthemmeffekt by the relatively flat conical slopes is therefore insufficient.

The invention is therefore based on the object to further develop a hydraulic or pneumatic drive for a tool clamp of the type mentioned so that a much improved locking of the drive is given in the absence of supply by the drive medium (oil / air).

To achieve the object, the invention is characterized in that the hydraulic or pneumatic drive serving piston is provided with an axial projection in which there is at least one radial recess for receiving locking elements, which are mounted radially movable in these recordings, wherein the locking elements cooperate with a movable in the axial direction under spring load locking body and a positive locking between the locking elements and the locking body is given.

In a preferred embodiment of the invention, it is provided that the lock between the movable under spring load locking body and connected to the approach of the hydraulic piston with radial play locking elements under centrifugal force is formed automatically nachsetzend.

With this technical teaching, there is the significant advantage that now no longer a non-positive locking is proposed according to the prior art, but a positive and thus secure locking is provided.

There is a positive locking between the locking elements and the associated locking body. There are several inclinations of the locking elements with the associated housing-fixed slopes of the body together.

A radially outer inclined at an angle to the axial longitudinal axis slope on the locking element cooperates with the arranged on the stationary outer sleeve hydraulic drive device.

On the other hand also act inclined at an angle to the axial longitudinal axis slopes of the locking elements, which are mounted radially inwardly; associated with associated slopes on the locking body.

The interlocking lock now comes about by the fact that between the outer periphery of the locking elements and the associated inner periphery of the stationary outer sleeve, a fixed stop is present, and under spring load in the axial direction movable locking body now presses the locking elements under displacement radially outward against said radially outer inclined surface between the locking element and the outer sleeve, so that there is an absolutely stationary and safe investment of the locking elements on the stationary outer sleeve.

This results in a positive connection between the locking body via the locking element to the corresponding inclined surface on the outer sleeve. So it does not exist anymore the danger that this lock will break loose.

On the contrary, it is provided according to the invention that, under appropriate centrifugal force, the interlocking lock even solidifies by repositioning.

This has the significant advantage that when eliminating the pressure oil supply for the hydromechanical drive an absolutely secure locking of the drawbar takes place, which in turn acts on the collets of the mechanical tensioning device.

• 1. Rotierender Einsatz, zum Beispiel bei Spindeln für Werkzeug- und Schleifmaschinen
• 2. Stehender Einsatz, wie zum Beispiel in Verbindung mit Drehrevolvern
• 3. Einspannung von Werkstücken zwecks Bearbeitung dieser Werkstücke. Die Werkstücke können hierbei auch auf transportablen Werkstückpaletten eingesetzt werden.

According to the invention, the following applications are preferred:

• 1. Rotating insert, for example with spindles for tool and grinding machines
• 2. Standing use, such as in connection with rotary turrets
• 3. Clamping of workpieces for the purpose of machining these workpieces. The workpieces can also be used on transportable workpiece pallets.

The invention has the following features:
The oil or air pressure is applied only briefly during the actuation of the drive device.

It is guaranteed a positive locking in the clamping position. The clamping force is kept 100% in the pressureless state.

Increasing rotational speed of rotation causes the centrifugal force to increase. Consequently, there is an increase in the clamping force and a resetting of the lock.

By the way, this results in very small installation dimensions.

The subject of the present invention results not only from the subject matter of the individual claims, but also from the combination of the individual claims with each other.

In the following the invention will be explained in more detail with reference to drawings showing only one embodiment. Here are from the drawings and their description further features essential to the invention and advantages of the invention.

Show it:

1 : Section through a hydromechanical drive according to the invention in two half sections, wherein

1a : the clamping device in the released position and

1b : show the tensioner in the cocked position.

2 : The side view of the hydraulic piston of the hydromechanical drive.

3 : The top view on the hydraulic piston.

4 : A partial section through the hydraulic piston.

5 : Section through the locking elements.

6 : Side view of the locking elements behind 5 ,

7 : Section through the locking body

8th : Front view of the lock body behind 7

9 : Half cut through the cylinder liner

10 : Section through the outer sleeve of the hydraulic drive

11 : Another embodiment of the hydromechanical drive according to 1 ,

In 1 is on the respective half sections on the left side of a known tensioning device 1 represented, which belongs to the prior art and which is described in more detail for example in a brochure of the company Ortlieb. The disclosure of this description is referred to. It should be fully included in the content of the disclosure of the present invention, as far as it depends on the description of the subject invention.

The right part of in 1 The clamping device is shown by the drive device according to the invention 10 educated.

The two parts are in position 11 joined.

The upper half-cut in 1 ( 1b ) is indicated by "b" positions, while the same parts in the lower half section are marked "a" positions. The same parts are provided with the same reference numerals.

The mechanical clamping device 1 According to the prior art operates essentially arranged evenly distributed on the circumference collets 2 , which are about beak-shaped to each other movable, with the rear part of the respective collet 2 thickened is formed and a pivot bearing 3 is designed tiltable or pivotable.

The voltage is applied via the claws arranged at the front end of the respective collet 7 that in appropriate shots 8th on the tool to be clamped 6 intervention.

A clamping cone 4 , which is axially displaceable, moves the corresponding collets 2 in its opening or clamping position.

An attachment flange 5 forms the receptacle for the tool 6 ,

The claw 7 the respective collet 2 then hangs on the shoulder 9 of the exciting tool 6 at.

The present invention is not limited to the tension of hollow shaft taper tools. It can be stretched all kinds of tools. It can also be used all other tensioning devices, because it is in the context of the present invention, only to the hydraulic / pneumatic drive any clamping device.

The tensioning device is in the embodiment shown by a pull rod 12 formed, with its front end over a thread 13 with the clamping cone 4 connected is.

The hydromechanical drive to 1 consists of two fixed and axially joined parts. The immediate position 11 The subsequent part is a cylinder liner 35 , in the 9 is shown in more detail.

Immediately axially to the one end of this cylinder liner 35 closes the outer box 33 on, in which the locking device 39 ( 11 ) is arranged.

The two parts 33 . 35 are for example according to 11 in the central image of a body 40 arranged and are mechanically fixed to each other by a front end cap 41 connected.

In the embodiment according to 1 are the two parts 33 . 35 also mechanically attached to each other. For better clarity, however, is the outer body 40 away. That is, the pressure oil supplies and the associated channels are in for simplicity 1 not shown. Likewise is not shown how the two parts 33 . 35 are mechanically clamped together.

There are only shown O-rings, which seal against ingress of hydraulic oil in the inner wall of a (in 1 not shown) basic body 40 provide.

Inside the in 9 illustrated cylinder liner 35 is a hydraulic piston 14 arranged axially displaceable under the action of a hydraulic oil.

On the left side of the hydraulic piston 14 Here is a cylinder chamber 15 formed while on the right side a cylinder chamber 16 (radially outward) is formed.

The radially outer cylinder chamber 16 passing over the inlet opening 18 supplied with pressurized oil is via a radial bore 20 with the radially inner cylinder chamber 17 connected.

The other cylinder chamber 15 stands over an inlet opening 19 in contact with pressure oil.

For the sake of simplicity, it will always be assumed in the following description of the supply of pressure oil. However, the invention should not be limited thereto. It is also possible to operate the entire assembly with compressed air.

In the relaxed position according to the half-cut 1a is the piston 14 in the release position. To reach the clamping position is now over the inlet opening 19 Pressure oil in the cylinder chamber 15a fed, causing the hydraulic piston 14 is moved to the right.

According to 2 - 4 is the hydraulic piston formed from a piston disc 30 at which with reduced diameter a piston neck 21 attaches.

In the area of the piston attachment 21 are two opposite windows 31 spared.

Through these windows 31 grab with radial play in the 5 and 6 illustrated locking elements 22 therethrough.

Each locking element 22 is approximately semicircular in side view and forms a radially outer and upper abutment surface 25 , which lies approximately at the same angle opposite a radially inwardly directed ramp surface 26b opposite.

These locking elements 22 act with a locking body 23 together, which is designed essentially as a sleeve.

This bush has an inner receptacle for the engagement of a compression spring 29 , with their other end on the end cap 41 according to 11 supported.

This is the locking body 23 always held under spring load in its left shifted position.

When filling pressurized oil into the inlet opening 19 So is the hydraulic piston 14 according to the lower half section 1a moved to the right in the position after 1b , This takes the hydraulic piston 14 due to its attachment to the approach 42 the drawbar 12 this pull rod to the right with. At the same time also the piston set 21 shifted to the right because of this fixed to the piston disc 30 of the hydraulic piston 14 connected is.

The on the piston neck 21 held with radial play locking elements 22 grip with their radially inwardly directed ramp surfaces 26b the associated ramp 24a of the locking body 23 on (see also 7 ) and take this also against the force of the compression spring 29 to the right with.

The locking body 23 is moved so far to the right until the locking elements 22 in the area of a fixed shoulder 34 on the outer sleeve 33 reach.

This allows the locking elements 22 move radially outwards and move according to the half-section after 1b in the desired blocking position.

The locking position is achieved by the radially outer shoulder 25 of the locking element 22 as a stop surface on the associated shoulder 34 the outer sleeve 33 abuts and on the other hand, the radially inwardly directed ramp surface 26a of the locking element 22 on an associated ramp 24b of the locking body 23 according to 7 rests.

So as soon as the locking elements 22 due to its axial displacement and its radial outward movement on the stationary shoulders 34 the outer sleeve 33 have created, the locking body begins 22 under the weight of the spring 29 at the associated inclined ramp surfaces 26a of the locking body 23 to wedge.

The actual positive lock is thus between the stop surface 25 of the locking element 22 and the stationary shoulder 34 the outer sleeve 33 ,

With increasing centripetal force, the locking elements wander 22 further out, so that the shoulders engaging in positive engagement with each other 25 . 34 slide along each other, and the locking body 23 is shifted more under spring load to the left, so nachsetzen the lock.

For the sake of simplicity, they have been shown in the drawing 1a illustrated sealing rings and their function is not described in detail. However, it is clear to those skilled in the art that these gaskets - as well as in 11 are shown - serve the seal against hydraulic oil.

For example, the locking body carries 23 a puncture 27 according to 7 to receive a corresponding sealing ring there.

Shoulders 34 form approximately an angle of 45 ° to the longitudinal axis and extend substantially over the entire circumference of the outer sleeve 33 ,

Accordingly, the stop surfaces 25 the curvature of these shoulders 34 semicircular formed so as a full-surface investment over the entire length of the locking elements 22 to reach.

In 11 is as an application example 1 shown that the entire drive device 10 in a basic body 40 is installed. It is therefore also the corresponding feed channels 37 and 38 represented for the hydraulic oil.

The transition from the clamping position to the release position will now be illustrated. This is on the 1b Referenced.

To achieve this transition is via the inlet opening 18 Pressure oil fed, which via the transverse bore 20 also in the radially inwardly directed cylinder chamber 17 arrives.

First, the piston stops, because the pressure oil on the larger cylinder chamber 17 Now first the front end of the locking body designed as a piston 23 drives and this against the spring force of the compression spring 29 moves to the right.

This will cause the locking elements 22 out of engagement with the ramps 24b and arrive at further displacement of the locking body 23 in the area of the steeper ramps 24a ,

This will cause the locking elements 22 free from the locking shoulders 34 and can move radially inward. This is the positive connection between the parts 34 . 25 lifted and with further action of pressure oil through the inlet opening 18 now shifts the entire arrangement, consisting of locking body 23 and pistons 14 , to the left in the release position according to half-section 1a ,

Important in this embodiment is therefore that in addition to the hydraulic piston 14 even the locking body 23 is designed as a piston which is acted upon on one side with pressure oil, while the other side is acted upon by spring force.

Of course, the application of spring force is not a compression spring 29 bound. It can also be used other energy storage, such as a plate spring, a leg spring or any other known energy storage, in particular also elastomeric energy storage.

The release of the locking position according to the half-section after 1b leads to a displacement of the drawbar 12 to the left and thus to the ejection of the tool.

In 11 is still shown schematically that it is not necessary for the solution that the drive device according to the invention 10 immediately and firmly with the tensioning device 1 connected is.

In the illustrated embodiment according to 11 the connection consists only of an extension rod 36 that with the drawbar 12 the drive device 10 connected is.

The parts mentioned 1 . 10 can be arranged in a relatively large spatial distance from each other.

LIST OF REFERENCE NUMBERS

1

jig

2

collet

3

pivot bearing

4

clamping cone

5

Standard intake

6

Tool

7

claw

8th

admission

9

shoulder

10

driving device

11

position

12

pull bar

13

thread

14

piston

15

cylinder chamber

16

cylinder chamber

17

cylinder chamber

18

inlet opening

19

inlet opening

20

drilling

21

piston extension

22

locking element

23

locking body

24

starting slope 24a , b

25

stop surface

26

ramp surface 26a , b

27

puncture

28

location hole

29

compression spring

30

piston disc

31

window

32

arrow

33

outer sleeve

34

shoulder

35

cylinder liner

36

extension rod

37

feed

38

feed

39

locking device

40

body

41

End cover

42

approach

Claims (15)

Hydraulic or pneumatic drive ( 10 ) for a tool clamp with clamping device ( 1 ), characterized in that a piston ( 14 ) with an axial piston extension ( 21 ), in which at least one radial recess ( 31 ) for receiving at least one locking element ( 22 ) is present, which radially movable in this at least one radial recess ( 31 ), wherein the at least one locking element ( 22 ) with an axial direction under load of a spring ( 29 ) movable locking body ( 23 ) and a positive locking between the at least one locking element ( 22 ) and the locking body ( 23 ) given is. Hydraulic or pneumatic drive ( 10 ) according to claim 1, characterized in that at least two locking elements ( 22 ) are provided. Hydraulic or pneumatic drive ( 10 ) according to one of claims 1 or 2, characterized in that the at least one locking element ( 22 ) Partial disk-shaped. Hydraulic or pneumatic drive ( 10 ) according to one of claims 1 to 3, characterized in that the at least one locking element ( 22 ) at least one radially inner inclined ramp surface ( 26 ) and at least one radially outer oblique stop surface ( 25 ), which surfaces at an angle to the longitudinal axis of the drive ( 10 ) stand. Hydraulic or pneumatic drive ( 10 ) according to claim 4, characterized in that the at least one radially outer oblique stop surface ( 25 ) of the at least one locking element ( 22 ) with a housing-fixed oblique shoulder ( 34 ) a radially outer outer sleeve ( 33 ) works together. Hydraulic or pneumatic drive ( 10 ) according to one of claims 4 or 5, characterized in that at least one radially inner oblique ramp surface ( 26 ) of the at least one locking element ( 22 ) with run-on slopes ( 24 ) on the radially inner locking body ( 23 ) works together. Hydraulic or pneumatic drive ( 10 ) according to one of claims 1 to 6, characterized in that the locking body ( 23 ) is sleeve-shaped. Hydraulic or pneumatic drive ( 10 ) according to one of claims 1 to 7, characterized in that the locking body ( 23 ) has a front-side piston surface, which the inner piston surface of the piston ( 14 ), wherein these piston surfaces of the locking body ( 23 ) and the piston ( 14 ) with the inner surface of the piston neck ( 21 ) of the piston ( 14 ) a cylinder chamber ( 17a . 17b ) into which the medium for releasing the clamping of the tool is introduced. Hydraulic or pneumatic drive ( 10 ) according to one of claims 1 to 8, characterized in that the piston ( 14 ) axially displaceable in a cylinder liner ( 35 ) with media connections ( 18 . 19 ) for acting on each of the end faces of the piston ( 14 ) is stored with pressure medium. Hydraulic or pneumatic drive ( 10 ) according to one of claims 1 to 9, characterized in that the outer sleeve ( 33 ) and the cylinder liner ( 35 ) in a radially surrounding body ( 40 ), which frontally by a cover ( 41 ) is completed, at which the spring ( 29 ) is supported. Hydraulic or pneumatic drive ( 10 ) according to claim 10, characterized in that the components of the drive ( 10 ) in the order end cover ( 41 ), Cylinder liner ( 35 ) and outer sleeve ( 33 ) are arranged axially one behind the other, and the cylinder liner ( 35 ) to the tensioning device ( 1 ) immediately adjacent or over the main body ( 40 ) is connected to this. Hydraulic or pneumatic drive ( 10 ) according to one of claims 1 to 11, characterized in that between clamping device ( 1 ) for receiving the tool and the drive ( 10 ) a pull rod ( 12 ) with radial approach ( 42 ) is at which approach ( 42 ) The piston ( 14 ) and thus the drawbar ( 12 ) moves axially and thus the tool is clamped or loosened. Hydraulic or pneumatic drive ( 10 ) according to claim 12, characterized in that the drawbar ( 12 ) via an extension rod ( 36 ) with the tensioning device ( 1 ), and the drive ( 10 ) and the tensioning device ( 1 ) are spatially separated from each other. Hydraulic or pneumatic drive ( 10 ) according to one of claims 1 to 13, characterized in that the drive ( 10 ) is formed rotatable about its longitudinal axis. Hydraulic or pneumatic drive ( 10 ) according to claim 14, characterized in that the locking between the displaceable under spring load locking body ( 23 ) and de with the approach ( 21 ) of the hydraulic piston ( 14 ) associated with radial play locking elements ( 22 ) is formed automatically under centrifugal force nachsetzend.

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