DD147823B1 - DEVICE FOR BREAKING THE REVERSE MOVEMENT OF TOOL SLICES - Google Patents

Description

Facility for. Braking the return movement of tool slides

Field of application of the invention

The invention relates to a device for braking the return movement of tool carriage, in particular a rear lathe, in which the forward and backward movement is caused by a cam against a biased force.

Characteristic of the known technical solution

It is known from DD-7 / P y \ 273 a hydraulic damping device which consists of a working piston and a control piston part connected to this, which has throttle surfaces. Both pistons are in operative connection with the lifting carriage, wherein the control piston part directly, and the working piston via a check valve with

your oil tank are connected. Between the control piston part and the oil reservoir an adjustable throttle is arranged.

With the setting of the throttle, the return speed can be influenced and in connection with the throttle surfaces on the control piston part, the vibration can be reduced. The still occurring vibrations arise because the throttle surfaces can be optimized only for a certain return movement and stroke size and that even for this simple Pail results in a very complicated geometry of the throttle surfaces. This device has the disadvantage that thus the time for the return movement is increased, whereby the usable tooth length on the workpiece, such as a hob reduced and thus decreases the productivity of the machine.

Object of the invention

The aim of the invention is to eliminate the disadvantages of the known devices

Explanation of the essence of the invention

The invention has for its object to provide a means for braking the return movement of tool slide, in which the decay phase is much reduced, or completely avoided «

In a device for braking the return movement of tool slide, in particular for backlamps, consisting of a known arrangement of a by spring pressure with a Werkzeugschiitben in tfirkverbindung standing working piston which is guided in a cylinder bore of a housing and the cylinder chamber via a one-way check valve with an oil reservoir connected is,

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and with a likewise known control piston, which is arranged in the same housing and longitudinally adjustably connected to the tool carriage, this is inventively achieved in that between the line from the cylinder chamber of the working piston to the cylinder space of the control piston and the line from the cylinder chamber of the control piston to the oil reservoir an adjustable Pressure relief valve is arranged.

With the inventive design of the device for braking the return movement of tool carriage, in which the height of the oil pressure can be kept almost constant by a pressure relief valve during the braking process, an important prerequisite for vibration reduction is given.

Here, the pressure relief valve causes the flow area under the force of a valve spring of the displaced oil quantity of the working piston adapts, which changes by the braking operation in the unit time from a maximum to zero. Pressure fluctuations or even pressure peaks are avoided because the occurrence of such an effect, the flow area of the valve immediately increases automatically and the effect of a pressure peak is already degraded in the emergence.

By meaningful vote of the closing point of the control piston with the size of the set oil backpressure and depending on the respective stroke size can be found by measuring an optimal ratio for each stroke size, in which the AusSchwingphase and the size of the amplitude is a minimum. In practical handling of the damping device, the optimized setting of the pressure at which the pressure relief valve is to respond is set on a scale in advance as a function of the stroke size.

In the mathematical treatment of the solution according to the invention, the conditions were identified, which are important for the further reduction of the decay phase, in addition

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heard that the volume of oil involved in the braking process should be as small as possible, the set oil pressure as small as possible and the diameter of the working piston should be kept as large as possible.

With the design of the device according to the invention, the decay phase can be greatly reduced or completely avoided. This makes it possible, for example, when backhoe hobs either to keep the flutes much narrower, so that the exploitation is increased, or it can be much faster and thus more productive behind-turned and / or back-ground with the usual widths of the flutes.

embodiment

The invention will be explained in more detail with reference to an embodiment "in the accompanying drawings show:

1: the arrangement of the lifting carriage on the bed carriage of a lathe (sectional side view),

FIG. 2: a section (top view) through the lifting carriage with the arrangement of the device according to the invention;

3 * representation of the angle X on the workpiece,

4: a sectional view (top view), lifting carriage with the device for braking the return movement

On a guideway 1 of a Y / erkzeugmaschine a bed carriage 2 is arranged, on which a lifting slide 3 formed with a web 4, with a tool carrier 5 is provided. Between the bed carriage 2 and the lifting slide 3 compression springs 6 are arranged in the direction of work. In extension of the axis of a tool is a

Workpiece 7, for example, a hob. In the right part of the lifting carriage 3, below the tool carrier 5, a device for braking the return movement is housed, the structure of which is explained in the description of FIG. 4. In the left part of the lifting carriage 3 below the workpiece 7 a Hubscheibenanlage 8 and a lifting disc are arranged with a drive.

2, the lifting carriage 3 is cut (top view) and shows the arrangement of the lifting disk system 8 for the lifting disk 9, as well as the device 10 for braking the Eücksprungbewegung ·

FIG. 3 shows the angle L required for retracting the tool and the subsequent decaying process using the example of the workpiece 7. The angle "£ is composed of the acceleration phase <£ * , the deceleration phase per ρ and the decay phase X-, ₀

4, the lifting carriage 3 is shown with the device 10 for braking the return movement in section. The device 10 is fixedly arranged on the bed carriage 2. In the housing of the device 10, a longitudinal bore 11 for a control piston 12 and a longitudinal bore 13 for a working piston 14, which bears against the web 4 of the lifting carriage 3, incorporated. In the longitudinal bore 11 is an annular groove 15 · The control piston 12 has at its closing edge throttle surfaces 16. The annular groove I5 connects via a bore 17, the cylinder chamber 18 of the control piston 12 with the cylinder chamber 19 of the working piston 14 «The cylinder chamber 19 is limited by the working piston 14th and of a perforated disc 20, which forms the plant of a compression spring 21, on the other hand, is guided in a bore 22 of the working piston 14. On the other side of the perforated disc 20 is a one-way check valve 23 »which

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On the one hand via a bore 24 and a line 25 is connected to an oil reservoir 26 and on the other hand via a bore 27 with a pressure relief valve 28 and to the cylinder chamber 18 is connected. The pressure relief valve 28 is adjustable from the outside, as the control piston 12th

The mode of action will be described below.

In Fig. 4, the device 10 is shown shortly after the return movement. By the rotation of the lifting plate 9, the advancing movement of the lifting carriage 3 against the force of the compression springs 6. According to the movement of the lifting carriage 3, the voltage applied to the web 4, by the force of the compression spring 21 working piston 14 is moved in the cylinder chamber 19 to the outside and pulls over the check valve 23 oil from the oil reservoir 26 after.

At the same time, the cylinder chamber 18 is filled with oil via the bores 27 and 29. The control piston 12 moves in the same direction as the working piston 14 and is on reaching the highest point of the lifting disc 9 with its throttle surfaces 16 having closing edge behind the annular groove 15 "over the bore 17. As soon as the highest point of the lifting disc 9 is exceeded , the return of the lifting carriage 3 under the action of the compression springs 6, so that without the device 10, the Hubscheibenanlage 8 would suddenly put on the lifting disc 9, wherein the shock is caused by the inertia of the lifting.

The oil return when returning the device 10 is done as follows. From the cylinder chamber 19, the oil is pressed through the bore 17 in the annular groove 15 and into the cylinder chamber 18 of the control piston 12 and passed through the bore 27 into the bore 24 from there via the line 25 to the oil reservoir 26 unthrottled. During the return stroke of the control piston 12 to the edge 15 ^{f of} the annular groove 15 flows

the oil ііЪег the throttle section 16 until such time as this throttle surface 16 is no longer effective, i. until it has closed · During this closing opens the pressure relief valve 28, so that a pressure increase can not occur and a nearly constant oil pressure in the system occurs, through which a very low decay phase is formed · With the opening of the pressure relief valve 28 is still in the cylinder chamber 19th located oil via the pressure relief valve 28, the hole 2? and 24 and the line 25 to the oil tank 26 passed · The duty cycle begins again.

Claims (1)

Erfinaungsanspruch: Device for braking the Rücksprungbey / egung of tool slide, especially for rear turning machines, consisting of a known arrangement of a standing by spring pressure with the tool slide working piston, which is guided in a cylinder bore of the device and the cylinder chamber via a one-way check valve with an oil reservoir and is connected via a line with the cylinder chamber of a control piston of the device, wherein the control piston is longitudinally adjustably connected to the tool slide and its cylinder space is also connected via a line to the oil reservoir, characterized in that between the conduit (17) from the cylinder chamber (19 ) & es working piston (14) to the cylinder chamber (18) of the control piston (12) and the line from Zylinderrauia (18) of the control piston (12) to the oil reservoir (26) an adjustable upper pressure valve (28) is arranged For this 2 sheets of drawings