Torque impulse tool and front plate therefor

The invention relates to a pulse tool, especially a pulse screwdriver, with a drive unit and a shaft driven by this pulse unit, which pulse unit comprises at least one rotor with at least two fins, one such surrounded hydraulic cylinder and a side of the hydraulic cylinder protruding through a front disk drive spindle. The front plate is disposed between the rotor and a front cover formed with a Hydraulikfluidbefülleinrichtung of the pulse unit.

Such a pulse tool is known from practice and is used for example to carry out a screw by means of the drive spindle and a corresponding tool on the drive spindle. The speed of such a screw essentially determines the efficiency of the pulse tool. The faster the screwing takes place, the higher the efficiency. This is unproblematic for hard screw with a small tightening angle generally. If the screw but soft, so the pulse tool takes a few moments to make the screw in the desired manner. Such a long period of time is not acceptable in general. To guarantee at an economical screwing in any case, pulse frequencies between 20 Hz and 30 Hz are preferred.

In a production corresponding pulse tools has been found that the pulse frequency may vary within certain limits and in comparison to the pulse frequencies above some Hz may be too large or too small well.

Object of the present invention, corresponding variations in the desired pulse frequencies in a simple manner and in particular already during assembly to compensate the lmpulswerkzeugs.

The object is achieved by the features of claim 1.

According to the invention this purpose, the front plate of the pulse tool at least on a separate through the lamellae high and low pressure chambers connecting the bypass opening.

By opening or closing the bypass opening, the pulse frequency can be increased or decreased accordingly, with opened bypass port hydraulic fluid from the high pressure to flow into the low pressure chamber, whereby the pulse frequency is increased. The corresponding increase of the pulse frequency depends in particular on the opening diameter of the corresponding bypass-opening, with a larger opening diameter, a faster hydraulic fluid exchange between the above mentioned chambers and thus faster traveling over corresponding sealing ridges of the hydraulic cylinder through the respective fins can take place.

Analog can be decreased by closing the bypass opening, the pulse frequency.

In principle there is the possibility that a corresponding bypass opening is formed in the front plate only after a first test of the lmpulswerkzeugs respect to the corresponding pulse frequency. Depending on the desired change in the pulse frequency, the bypass opening is equipped with an appropriate opening diameter. There is also the possibility to close an already existing bypass opening at least partially, to change in accordance with the pulse frequency, or to vary the aperture diameter of the bypass opening. For example, the orifice diameter could be increased if a corresponding increase in the pulse frequency is desired.

A simple way for closing and opening the respective bypass opening can be seen that this is arranged by means of a between the front plate and the front cover, in particular ball-shaped closing body is closed. Depending on the desired change in the pulse frequency of the corresponding closure member is removed or used to seal the bypass opening.

By only one bypass opening only relatively few variations of the pulse frequency is possible. For example, can be achieved by opening or closing a bypass opening the pulse frequency increase or decrease by a few Hz. Are more variations of the pulse frequency desired, two or more bypass openings forming a bypass opening group. These bypass openings of the bypass opening group can then be used in a corresponding change of the pulse frequency by opening or closing one or more bypass openings. It connects a bypass opening group corresponding to high and low pressure chamber of lmpulseinheit. This means that all bypass openings of the bypass opening group are applicable to the appropriate hydraulic fluid exchange between the chambers in any combination. Is there such a bypass opening group for example, three bypass openings, so is understood that one, two or all three bypass openings can be closed in accordance with associated closing body is opened or.

For example, if four or more panels for pulse unit is used, also in accordance with two or more high and low pressure chambers are in pairs separated by it. In this connection it may furthermore be advantageous if bypass opening groups are arranged in pairs diametrically opposite each other. An arrangement is made so that each is associated with a high-pressure chamber, a bypass opening group, each high pressure chamber own bypass opening group can be assigned.

There is the possibility that the corresponding opening diameter of the bypass ports of each bypass opening group are equal. It is also conceivable that the opening diameters of each bypass opening a bypass opening group being different. This means that, for example, the bypass opening is closed with the largest opening diameter alone, to allow for a certain pulse frequency increase, while opening the bypass port with the smallest opening diameter of a lower pulse frequency increase is realized. Again, appropriate combinations of opening or closing all bypass ports a bypass opening group are possible.

Usually an above-described pulse tool is designed not only for one direction of rotation, but for right and left rotation. To amend the pulse frequency in both directions of rotation, bypass opening groups can be arranged for forward and reverse rotation of the drive spindle. Arrangement of the bypass opening groups, number of bypass openings of each bypass opening group and diameter of each bypass opening can be varied according to the foregoing.

It is possible that each high-pressure chamber is associated with a corresponding bypass opening group, which may be sufficient also when only one or two of the high-pressure chambers a corresponding bypass opening group is assigned Zug.

In order to be able to close in accordance with each of the bypass openings through only one type of locking bodies, it is certainly advantageous when the closing body for all bypass ports each have the same diameter. This can in particular be effected in that each bypass opening in the direction of the front cover a correspondingly shaped sealing seat for the closing body, wherein the sealing seat can be formed by a substantially conical extension of the bypass opening. This conical expansion can be the same for all the bypass openings, so that are useful with the same diameter or the same dimensions in accordance with the closing body.

The pulse tool is filled before delivery to the user with hydraulic fluid, wherein the filling is usually made directly to the pulse unit. Whereas a Hydraulikfluidbefülleinrichtung used. In order to enable filling of the pulse unit with hydraulic fluid in a simple manner, the Hydraulikfluidbefülleinrichtung the cover at least on one, in particular closable filling opening. By this, the pulse unit is filled with hydraulic fluid under a vacuum, and in particular, care is taken during such a filling that no bubbles remain within the pulse unit.

After filling of the pulse unit it is then in the impulse tool can be arranged and connected to the corresponding drive unit. Before the filling is according pistons for example by a screw-in sealing pin or and optionally closed a closing body.

Advantageously, to each bypass opening be relatively orientable the filling opening, so that the corresponding closing body can be inserted and removed for the bypass openings through the filling opening.

Regarding the opening diameter of the corresponding bypass openings of each bypass opening group should also be noted that these may be affected in the corresponding bypass opening group for CW or CCW rotation in the reverse order.

As already described, the pulse frequency can be varied through the bypass openings and the pulse tool will be delivered with a certain pulse fundamental frequency. However, there is during use of the pulse tool, the possibility that these pulse fundamental frequency changes, for example by leakage of hydraulic fluid, changes in temperature of the hydraulic fluid and thereby causing changes in pressure, etc. In order to permit adaptation of the fundamental frequency in terms of these influences during operation, pulse unit can be connected to their drive spindles opposite end have connected to a compensation chamber fluid port. This compensation chamber can ie compensating volume can be varied to compensate for the foregoing effects in volume. Such variation may be effected for example by an elastic membrane as a limitation of the compensation chamber. The elastic membrane is deflected, when the hydraulic fluid at higher temperatures occupies a higher volume so that the corresponding additional volume is taken from the balance chamber by deflection of the diaphragm and thereby the basic pulse frequency is kept unchanged. Cools the hydraulic fluid again, hydraulic fluid is supplied from the equalizing chamber via the corresponding fluid port of the pulse unit again.

Also advantageous in this connection if the corresponding compensation chamber is pressure-dependent variable in their compensation volume not only, but instead is pressure independent variable. This is for example the possibility of providing a larger compensating volume at a first filling the pulse unit with hydraulic fluid, which can compensate in a simple manner in particular corresponding leakage during the further use of the pulse unit.

An easy way for such a pressure-independent variable image compensating volume can be seen when the compensation chamber is limited by the hydraulic cylinder and an adjustable in particular by rotation longitudinally compensating piston. The balance piston may be rotatable by the worker from the outside, so that the appropriate setting before the compensating volume by the worker, during or even after a use of the pulse tool occur.

To fix the appropriate balance piston in a desired rotational position in a simple manner, the balance piston in at least one rotational position can be fixed relative to the hydraulic cylinder by means of a fixing device.

The invention also relates to a corresponding front plate of the type described previously, which can be used with a corresponding pulse tool between pulse unit and the front cover. Such front panel has the corresponding bypass openings or bypass opening groups and may optionally be used as a retrofit component for pulse tools already used.

In the following the invention is explained and described with reference to the drawing accompanying figures.

Show it:<dl id="dl0001"><dt>Fig. 1</dt><dd>a side view of a pulse tool with at least drive unit and pulse unit;</dd><dt>FIG. 2</dt><dd>a longitudinal section through an impulse unit with a drive spindle;</dd><dt>Fig. 3</dt><dd>a section along the line III-III of a corresponding pulse unit (in Fig. 2);</dd><dt>Fig. 4</dt><dd>a detailed illustration of a front end of the pulse unit according to Figs. 2 and</dd><dt>Fig. 5</dt><dd>a front view of a front plate according to Fig. 4.</dd></dl>

FIG. 1 shows a side view of a pulse tool 1 with at least one drive unit 2 and a pulse unit 3. From the pulse unit 3 is a drive spindle 11 in front, to which an appropriate tool can be attached, for example, a screw, such as a socket wrench or the like.

Typically, such a pulse tool is equipped with a pneumatic motor as a drive unit and can be operated in both a rule for tightening and for loosening a screw with right and left rotation.

In Fig. 2 in particular, the pulse unit 3 is shown in FIG. 1 in a longitudinal section. The pulse unit 3 is arranged in an optionally multi-part housing 35th The pulse unit 3 includes a rotor 4 which is drivingly connected to the drive unit the second In the rotor 4 slats 5, 6, 7 and 8 are radially adjustably supported, see also Fig. 3. In each case two diametrically opposed vanes 5, 6 and 7, 8 are urged radially outwards by respective pressure springs 36. The free ends of the slats 5, 6, 7, 8 are in the range of sealing webs 37, see also Fig. 3, on an inner contour of a hydraulic cylinder 9 of which they separate high- and low-pressure chambers 14, 15 from each other. Rotor lamellae sealing webs and hydraulic cylinders interact in a conventional manner to produce pulse beats with a certain pulse frequency. In general, a pulse frequency is 20 to 30 Hz, since in such a frequency pulse an economical screw is ensured.

The pulse unit comprises at its 3 in FIG. 2, left-end of a front plate 10 and a front cover 12. The front panel 10 is disposed substantially between the rotor 4 and fins 5, 6, 7, 8 and the front cover 12th In the front cover 12 is a Hydraulikfluidbefülleinrichtung 13 is arranged. This includes at least one filling opening 24 which is closed by a closing ball and a screw-in sealing pin or pistons 38 and 39 after filling the pulse unit 3 with hydraulic fluid.

By the front cover 12, the pulse unit is sealed on the side of the drive spindle 11, so that hydraulic fluid can be exchanged via sealing gaps between the front plate 10, front cover 12 and the rotor 4 and fins 5, 6, 7, 8 between high pressure and low pressure chamber.

The drive spindle 11 passes through both the front plate 10 and the front cover 12 and is faced to the arrangement of an appropriate tool from the tool pulse first

At its the drive spindle 11 opposite end 25 has the pulse unit 3, a fluid opening 27 in the hydraulic cylinder. This are the chambers 14, 15, see also Fig. 3, inside the pulse unit 3 with a compensation chamber 26 with appropriate compensation volume 28 in conjunction. This compensation chamber 26 is limited by the hydraulic cylinder 9 and a longitudinally adjustable 30 by rotating balance piston 29th

In the position shown in Fig. 2 of the balance piston 29 is rotated as far as possible in the direction of the hydraulic cylinder 9 so that the corresponding compensation chamber 26 is formed substantially only by the cylindrical chamber shown in FIG. 2.

The balance piston 29 can be relative to the hydraulic cylinder 9 in Fig. 2 adjusted to the right, whereby the compensation chamber 26 a larger compensating volume 28 is replaced. Certain positions of rotation of the balance piston 29 can be fixed by a pin as a fixing 31, wherein, for example, four, six or even more rotary positions in one revolution of the balance piston 29 are correspondingly fixed.

In Fig. 3 is a section along the line III-III of Fig. 2 is shown. In particular, the arrangement of the high-pressure chambers 14 and low-pressure chambers 15 between each two slats 5, 6, 7 and 8 respectively can be seen. These are mounted radially in the rotor 4 externally adjustable and druckfederbeaufschlagt. In the position shown in FIG. 3, two high-pressure chambers 14 and two low-pressure chambers 15 each lie diametrically opposite one another, the respective fins 5, 6, 7, 8 are still just in sealing contact with the corresponding sealing stays 37th The rotational direction of FIG. 3 is indicated by reference numeral 34, in which connection a clockwise rotation of the rotor and accordingly of the drive spindle 11, see also Fig. 2, is effected.

In FIG. 4 is a detailed view of the pulse unit 3 in particular for front panel 10 and front cover 12 is illustrated. Are seen in the front plate of bypass ports 16 and closure member 19 in the form of locking balls which lock these bypass openings. The closure balls 19 are held between front panel 10 and the front cover is 12th The bypass ports are connected to respective chambers in the interior of the pulse unit 3 in connection. Each bypass opening 16, 17, 18, see also Fig. 5, in the direction of the front cover 12 has a receiving seat 33 for the arrangement of the corresponding locking ball 19. The housings 33 have the same cross section for all the bypass openings, so that each of the bypass openings 16, 17, 18 can be closed with the same diameter by a closing ball 19th Each receiving seat 33 has a cross-section substantially to a from a corresponding opening diameter 23 of the bypass openings extending conical portion and an adjoining substantially cylindrical portion. The conical part of the closing ball 19 is in sealing engagement.

The opening diameter 23 of the various bypass openings 16, 17, 18 are different, see in particular Fig. 5,.

The corresponding bypass openings 16, 17, 18, are summarized in FIG. 5 to bypass opening groups 20, 32, 22 and 32. The bypass opening groups 20 and 21 are connected to respective high-pressure chambers 14 of FIG. 3 in conjunction with an analog connection through the bypass opening groups 22 and 32 with high-pressure chambers with an inverse operation, ie counterclockwise rotation takes place according to FIG. 3.

In the embodiment according to Fig. 5, each bypass opening group on three bypass openings 16, 17, 18. The arrangement of the bypass ports 16, 17, 18 carried out for the bypass opening groups 20 and 21 in the same and for the bypass opening groups 22 and 32 in the reverse direction. The various bypass openings 16, 17, 18 have in this order on decreasing opening diameter 23rd That is, the two by-pass opening 16 has the largest and the bypass opening 18 of the smallest orifice diameter.

The bypass opening groups 20, 21 and 22, 32 are each located diametrically opposite each other and associated with the respective high pressure chambers. By locking balls 19 unclosed bypass openings 16, 17, 18, hydraulic fluid enters the low pressure chambers and flows primarily through the center 40 of the front panel to the left side thereof corresponding to Fig. 4 from the direction of the high-pressure chambers, so that a hydraulic fluid exchange in this way between the chambers is carried out and thus to a faster crossing of the sealing ridges of the hydraulic cylinder through the slats and thus a pulse rate increase. Depending on the open bypass opening takes place a greater or lesser hydraulic fluid exchange. For the three illustrated bypass openings 16, 17, 18 of each bypass opening group 20 with correspondingly different opening diameters arise in this way 2³ Settings of the hydraulic fluid exchange due corresponding bypass ports open. Thus, a pulse frequency for setting a corresponding pulse fundamental frequency is eight times varied by certain amounts. The corresponding pulse fundamental frequency is set prior to delivery of the pulse tool in particular in the range of 20 Hz to 30 Hz. The appropriate orifice diameter of the bypass ports 16, 17, 18 may be in the range of some tenths of millimeters. There is also the possibility of less or more bypass openings of each bypass opening group to arrange so that this results in correspondingly less or more settings for the pulse fundamental frequency. Typically, when using the pulse unit in clockwise and anticlockwise rotation a symmetrical assignment of bypass ports with or without closing body-sense result, the same pulse frequency results in both directions at an analogous arrangement of the closing body. However, it is also possible to provide for right and left rotation different arrangements of bypass ports and / or bypass opening groups to stronger than the other form, for example, a direction of impact with other frequency options.

A closing of the bypass opening groups 20, 21 for clockwise rotation 34 of FIG. 3, ie with assignment of the bypass opening groups 22, 32 to the high-pressure chambers, is not required due to the pressure neutrality between the front and back of the front plate 10. It should again be pointed out that only those bypass ports are active, which are connected to the low pressure chamber and the low pressure side in connection. The low pressure chamber changes when changing the direction of rotation. Pressure in both directions of rotation primarily about the center 40 to the left side of the front panel 10, for example, see Fig. 4, taken with bypass ports are pressure neutral and therefore ineffective on the pressure side or in association with the pressure chamber 14 with or without closing body.

Placing the closing body 19 in the corresponding receiving seats 33 is performed by the filling opening 24, the front cover 12 is according to the assignment of the filling opening 24 to each of the bypass openings 16, 17, 18 rotate.

A corresponding front panel 10 can also be retrofitted for already in use pulse tools generally, see in particular FIGS. 2 and 4, only one exchange of a corresponding front plate previously used with the front plate must be in accordance with the invention.