DE2037338A1 - Process for producing grooves in gears, in particular in the internal toothing of gear sleeves for manual transmissions and tool electrodes for carrying out the process - Google Patents

Description

July 25, 1970. .

Attachment to

patient

Cc- ^Amelduns

HOBEEI BOSCH GMBH, Stuttgart (Germany) Process for producing grooves in gears, in particular

in the internal toothing of gear sleeves for gearboxes g as well as tool electrode for carrying out the process

The invention relates to a method of manufacturing ^& interior °

of grooves in gears, especially in the / toothing of Gear sleeves for gearboxes and on the structure of a tool electrode for carrying out the process.

Grooves on the tooth flanks of the internal toothing of gear sleeves are intended for synchronized motor vehicle gearboxes After engaging the gear, the corresponding parts pushed into one another during this process, such as the sleeve and gearwheel secure against each other.

109886/0869 " ² "

Robert Bosch GmbH R. '

Stuttgart

Such grooves have so far been made by machining processes (e.g. scraping or pushing). These processes result in long piece times and it is in connection with them a separate deburring is necessary. Furthermore, such a method can be carried out as a result of the high piece and thus cycle times difficult to incorporate into an automatic process sequence for the production of gears.

The invention is based on the object of providing a method for ent-H winding that allows grooves to be worked into gears, e.g. in the internal teeth of gear sleeves, in an economical way, These grooves are to be created primarily on the flanks of the teeth. The process should have a sufficiently short cycle time enable this process step to be included in a machine line.

This object is achieved according to the invention in that the gear sleeve is pushed over a tool electrode, the gear sleeve as the anode and the tool electrode as the cathode are connected in a circuit and an electrolyte is pumped under pressure between the sleeve and the electrode at those points where the anode and cathode are opposite one another so that these places is removed anode material of W and this gives rise grooves.

Gear sleeve and tool electrode change their relative position during the electrolytic removal of the anode material not to each other.

The tool electrode for carrying out the method is according to the invention built in sandwich form in such a way that only at electrically conductive material is on the outside at those points at which electrolytic removal is to take place on the anode has, while at the other points insulating material is arranged between the electrically conductive material.

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Robert Bosch GmbH E. 9944 Pf / Kf

Stuttgart

Further details will emerge from the example which is described below with reference to the figures. Included demonstrate

Fig. 1 is a section through one according to the invention Process machined gearbox sleeve,

2 shows a section through the electrode according to the invention, as used in the method according to the invention, f

3 shows a detail from the electrode in plan view and

4 shows the plan view of an arrangement for producing tapering grooves in the cutout.

In Fig. 1, a gear sleeve 1 with two grooves 2 is in section shown.

According to FIG. 2 and 3, the tool electrode is composed of the following parts: a · electrode terminal plate 10, a support 11, a lower cover 12, a lower electrode λ part 13 with the shape of the socket teeth adapted teeth 30 'of a center cover 14, an upper electrode part I5 with further teeth 30 adapted to the shape of the socket teeth, an upper cover 16 and a one-in part I7. All parts are fixed in their position relative to one another by cylinder pins 18 and firmly connected to one another by a cylinder screw 19. The support 11 and the covers 12, 14 and 16 are made of glass fiber reinforced plastic, the electrode parts 10, I3, 15 and 30 are made of brass.

The contour of the covers 12, 14 and 16 is shown in Fig. 3 as a dashed line ⁷ Jl. drawn in; at the same time it represents the

- 4 - 109888/0869

Robert Bosch GmbH ■ R. 9944 Pf / Kf

Stuttgart

outer edge of the gear sleeve 1 to be machined. The space between the edges of the teeth 30 and the dashed The contour of the covers 31 represents the working gap for the electrochemical removal Electrolyte channels 32, which are in column 33 on the tooth tips flow out. They serve just like the channels 34 in the covers 12 and 16 of the implementation of the electrolyte.

For producing grooves in the internal toothing of a gear sleeve 1 this is after a pre-adjustment via the guide part 17, which is used for the precise adjustment, on the electrode arrangement pushed until it rests on the support 11. It is held by four bolts pressing on the outer part of the socket 20 held, which simultaneously establish the connection between the sleeve and the positive pole of the power source. The tight fit of the The socket 1 is ensured by the precisely corresponding contours of the socket 1 and the covers 12, 14 and 16. In which The embodiment according to FIG. 1 has two grooves 2 in the internal toothing a gear sleeve 1 incorporated. For this purpose, 20% strength is obtained through channels in the electrode connection plate aqueous sodium nitrate solution as an electrolyte under pressure of 1 atü introduced via channels 32 (Fig. 3) and the column 33 in the working gap 35 between the electrode and the gear sleeve got. Flows through channels 34 in covers 12 and 16 the electrolyte again. "If necessary, know the direction of the electrolyte flow also vice versa. - Between the electrode parts 13 and 15 on the one hand and the gear sleeve 1 on the other hand a voltage of 15.5 V is applied. This flows in

ο Current of approx. 450 A with a current density of approx. 0.25 A / mm. Grooves are created during an exposure time of 0.4 minutes 0.3 mm deep. Subsequent deburring of the edges is not necessary with this method.

With the method according to the invention it is also possible to expire Produce grooves on the tooth flanks. The structure

109886/0869 " ⁵ "

_ 5 - ·

Eobert Bosch GmbH. R. 9944 Pf / Kf

Stuttgart

the tool electrode can correspond to that shown in FIG. However, the electrode can also be constructed according to FIG be, with essentially only the direction of electrolyte flow is changed. The electrode and the unmachined tooth flanks form an angle with each other, the size of which is different depends on the shape that the tapering groove should have.

Fig. 4 shows in a partial view looking along of the tooth flank the gear sleeve 1, the support 11, the lower cover 12, the lower electrode 13, the middle cover j 14, the top electrode 15 and the top cover 16. The " One-part 17 is shown in Fig. 4 liicht. The electrolyte is according to the direction of the arrow between the middle cover 14 and the lower or upper electrode 13 or passed through, deflected on the gear sleeve 1 and occurs at the flank ends 40 from between the gear sleeve 1 on the one hand and the electrodes 13 and 15 and the covers 12 and 16 on the other hand formed working gaps again.

The advantage of the invention is that it is possible to produce grooves in gears, e.g. in gear sleeves by using electrolytic removal without feed because of the short cycle time required and because of the possibility of automating the process in a machine line to be included. Subsequent deburring of the created edges is not necessary. Another advantage can be seen in the fact that it is possible to work grooves in already hardened workpieces.

The progressiveness of the invention is underlined by that it is possible to machine several workpieces at the same time within a cycle time, the number of which depends on the design of the plant is aimed, so that a very good economic efficiency of the procedure results.

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Claims (7)

Robert Bosch GmbH E. 9944 Pf / Kf Stuttgart 23.7.I97O claims 1.1 Method of making grooves with precisely delimited Contour in gears, especially in the internal gearing of gear sleeves for gearboxes, characterized in that the gear sleeve has a composite The tool electrode is pushed into a circuit, the gear sleeve as the Anode ™ and the tool electrode as the cathode switched on and between sleeve and electrode on those Place an electrolyte under pressure, at which the anode and cathode are opposite each other, so that at these Place anode material is removed and grooves are created as a result. 2. The method according to claim 1, characterized in that the relative position of the gear sleeve and tool electrode to- fe each other during the electrolytic erosion of the anode material not verander t is. 3. Tool electrode for carrying out the method according to Claim 1, characterized in that it is constructed in sandwich form that only at those points electrically conductive material is on the outside, on which an electrolytic removal has to take place on the anode, while at the other points insulating material is arranged between the electrically conductive material. 10Ü8S / O869 ~ ⁷ " Robert Bosch GmbH E. 9944 Stuttgart 4. Tool electrode according to claim J, characterized in that that their insulating parts are dimensioned so that they fix the gear sleeve, while the electrically conductive Share a gap between the internal teeth of the gear sleeve and the conductive electrode parts for the Allow the electrolyte to pass through. "| 5. Tool electrode according to claim 4, characterized in that that there are gaps at the tooth tips of the electrically conductive parts of the electrode through which the electrolyte can flow in or out. 109886/0869 Blank page